subject:(plasma simulation)

Virginia Tech

1. Glesner, Colin Christopher. Development of Magnetic Nozzle Simulations for Space Propulsion Applications.

Degree: MS, Aerospace and Ocean Engineering, 2017, Virginia Tech

► A means of space propulsion using the channeling of plasma by a divergent magnetic field, referred to as a magnetic nozzle has been explored by… (more)

Subjects/Keywords: Plasma; Simulation

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APA (6^th Edition):

Glesner, C. C. (2017). Development of Magnetic Nozzle Simulations for Space Propulsion Applications. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/74947

Chicago Manual of Style (16^th Edition):

Glesner, Colin Christopher. “Development of Magnetic Nozzle Simulations for Space Propulsion Applications.” 2017. Masters Thesis, Virginia Tech. Accessed December 13, 2019. http://hdl.handle.net/10919/74947.

MLA Handbook (7^th Edition):

Glesner, Colin Christopher. “Development of Magnetic Nozzle Simulations for Space Propulsion Applications.” 2017. Web. 13 Dec 2019.

Vancouver:

Glesner CC. Development of Magnetic Nozzle Simulations for Space Propulsion Applications. [Internet] [Masters thesis]. Virginia Tech; 2017. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/10919/74947.

Council of Science Editors:

Glesner CC. Development of Magnetic Nozzle Simulations for Space Propulsion Applications. [Masters Thesis]. Virginia Tech; 2017. Available from: http://hdl.handle.net/10919/74947

Ruhr Universität Bochum

2. Meßerer, Peter. Investigations and development of plasma surface processes : etching of semiconductors and sterilisation of polymers.

Degree: 2010, Ruhr Universität Bochum

URL: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-29714

► Es wurde der Einfluss von Plasmen auf Materialien untersucht. Dabei wurden Langmuir-Sonden, SEERS, Aktinometrie, UV- Spektroskopie und energieaufgelöster Massenspektroskopie an zwei verschiedenen Plasmareaktoren benutzt, zum… (more)

Subjects/Keywords: Plasma; Plasmaätzen; Plasma-Simulation; Sterilisation; Messung

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APA (6^th Edition):

Meßerer, P. (2010). Investigations and development of plasma surface processes : etching of semiconductors and sterilisation of polymers. (Thesis). Ruhr Universität Bochum. Retrieved from http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-29714

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Meßerer, Peter. “Investigations and development of plasma surface processes : etching of semiconductors and sterilisation of polymers.” 2010. Thesis, Ruhr Universität Bochum. Accessed December 13, 2019. http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-29714.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Meßerer, Peter. “Investigations and development of plasma surface processes : etching of semiconductors and sterilisation of polymers.” 2010. Web. 13 Dec 2019.

Vancouver:

Meßerer P. Investigations and development of plasma surface processes : etching of semiconductors and sterilisation of polymers. [Internet] [Thesis]. Ruhr Universität Bochum; 2010. [cited 2019 Dec 13]. Available from: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-29714.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Meßerer P. Investigations and development of plasma surface processes : etching of semiconductors and sterilisation of polymers. [Thesis]. Ruhr Universität Bochum; 2010. Available from: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-29714

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Virginia Tech

3. Esmond, Micah Jeshurun. Two-dimensional, Hydrodynamic Modeling of Electrothermal Plasma Discharges.

Degree: PhD, Mechanical Engineering, 2016, Virginia Tech

URL: http://hdl.handle.net/10919/81447

► A two-dimensional, time-dependent model and code have been developed to model electrothermal (ET) plasma discharges. ET plasma discharges are capillary discharges that draw tens of… (more)

Subjects/Keywords: Electrothermal plasma; capillary discharge; plasma simulation

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APA (6^th Edition):

Esmond, M. J. (2016). Two-dimensional, Hydrodynamic Modeling of Electrothermal Plasma Discharges. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/81447

Chicago Manual of Style (16^th Edition):

Esmond, Micah Jeshurun. “Two-dimensional, Hydrodynamic Modeling of Electrothermal Plasma Discharges.” 2016. Doctoral Dissertation, Virginia Tech. Accessed December 13, 2019. http://hdl.handle.net/10919/81447.

MLA Handbook (7^th Edition):

Esmond, Micah Jeshurun. “Two-dimensional, Hydrodynamic Modeling of Electrothermal Plasma Discharges.” 2016. Web. 13 Dec 2019.

Vancouver:

Esmond MJ. Two-dimensional, Hydrodynamic Modeling of Electrothermal Plasma Discharges. [Internet] [Doctoral dissertation]. Virginia Tech; 2016. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/10919/81447.

Council of Science Editors:

Esmond MJ. Two-dimensional, Hydrodynamic Modeling of Electrothermal Plasma Discharges. [Doctoral Dissertation]. Virginia Tech; 2016. Available from: http://hdl.handle.net/10919/81447

Princeton University

4. Campanell, Michael. Plasma Interaction with Electron-Emitting Surfaces .

Degree: PhD, 2014, Princeton University

URL: http://arks.princeton.edu/ark:/88435/dsp01cj82k951c

► Electron emission from surfaces occurs in many plasma systems. Several types including secondary, thermionic and photon-induced emissions are intense under certain conditions. Understanding the effects… (more)

▼ Electron emission from surfaces occurs in many plasma systems. Several types including secondary, thermionic and photon-induced emissions are intense under certain conditions. Understanding the effects of emission on the sheaths that govern plasma-surface interaction is important. This dissertation predicts some emitting sheath phenomena that were not reported in past studies. For example, most previous theoretical models assumed that an emitting sheath potential is always negative and that ions always accelerate into the wall. We show when the emission is intense that the sheath potential can become positive, fundamentally changing how the plasma and wall interact. In this inverse sheath state, ions are repelled, suggesting for instance that (a) no presheath exists in the plasma interior, (b) emitting walls could be used in applications to stop sputtering. Another topic considered is the transit of emitted electrons across the plasma to other surfaces, which is possible in low collisionality plasma systems. When transit occurs, the flux balance is a complex global problem where the sheaths at opposite surfaces are coupled through their exchange of emitted electrons. We also show that secondary emission can trigger a variety of sheath instability phenomena that change the state of the plasma-wall system or cause oscillations preventing steady state. Lastly, we analyze a mechanism where emitted electrons return to the same surface and knock out secondaries, which return and knock out more secondaries, etc., feedback amplifying the emission intensity. The four phenomena will be analyzed theoretically and verified with particle-in-cell simulations: (a) inverse sheath, (b) sheath coupling via transiting electrons, (c) sheath instabilities, (d) returning electron amplification. Consequences of these processes on the sheath potentials, wall heating, loss rate of charge, and cross field transport (near-wall conductivity) are discussed throughout. Possible implications are suggested for fusion machines, plasma propulsion engines, probes, dusty plasmas, RF discharges, and surfaces in space. Advisors/Committee Members: Kaganovich, Igor (advisor).

Subjects/Keywords: Emission; fusion; Plasma; Sheath; Simulation

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APA (6^th Edition):

Campanell, M. (2014). Plasma Interaction with Electron-Emitting Surfaces . (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp01cj82k951c

Chicago Manual of Style (16^th Edition):

Campanell, Michael. “Plasma Interaction with Electron-Emitting Surfaces .” 2014. Doctoral Dissertation, Princeton University. Accessed December 13, 2019. http://arks.princeton.edu/ark:/88435/dsp01cj82k951c.

MLA Handbook (7^th Edition):

Campanell, Michael. “Plasma Interaction with Electron-Emitting Surfaces .” 2014. Web. 13 Dec 2019.

Vancouver:

Campanell M. Plasma Interaction with Electron-Emitting Surfaces . [Internet] [Doctoral dissertation]. Princeton University; 2014. [cited 2019 Dec 13]. Available from: http://arks.princeton.edu/ark:/88435/dsp01cj82k951c.

Council of Science Editors:

Campanell M. Plasma Interaction with Electron-Emitting Surfaces . [Doctoral Dissertation]. Princeton University; 2014. Available from: http://arks.princeton.edu/ark:/88435/dsp01cj82k951c

University of California – Irvine

5. McClenaghan, Joseph Timothy. Gyrokinetic simulation of current-driven instabilities.

Degree: Physics, 2015, University of California – Irvine

URL: http://www.escholarship.org/uc/item/8r66p1hk

► The gyrokinetic toroidal code(GTC) capability has been extended for simulating current- driven instabilities in magnetized plasmas such as kink and resistive tearing modes with kinetic… (more)

Subjects/Keywords: Plasma physics; gyrokinetic; internal; kink; MHD; simulation

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APA (6^th Edition):

McClenaghan, J. T. (2015). Gyrokinetic simulation of current-driven instabilities. (Thesis). University of California – Irvine. Retrieved from http://www.escholarship.org/uc/item/8r66p1hk

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

McClenaghan, Joseph Timothy. “Gyrokinetic simulation of current-driven instabilities.” 2015. Thesis, University of California – Irvine. Accessed December 13, 2019. http://www.escholarship.org/uc/item/8r66p1hk.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

McClenaghan, Joseph Timothy. “Gyrokinetic simulation of current-driven instabilities.” 2015. Web. 13 Dec 2019.

Vancouver:

McClenaghan JT. Gyrokinetic simulation of current-driven instabilities. [Internet] [Thesis]. University of California – Irvine; 2015. [cited 2019 Dec 13]. Available from: http://www.escholarship.org/uc/item/8r66p1hk.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

McClenaghan JT. Gyrokinetic simulation of current-driven instabilities. [Thesis]. University of California – Irvine; 2015. Available from: http://www.escholarship.org/uc/item/8r66p1hk

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – Irvine

6. Fulton, Daniel. Kinetic simulation of edge instability in fusion plasmas.

Degree: Physics, 2015, University of California – Irvine

URL: http://www.escholarship.org/uc/item/6686z6fg

► In this work, gyrokinetic simulations in edge plasmas of both tokamaks and field reversedconfigurations (FRC) have been carried out using the Gyrokinetic Toroidal Code (GTC)… (more)

▼ In this work, gyrokinetic simulations in edge plasmas of both tokamaks and field reversedconfigurations (FRC) have been carried out using the Gyrokinetic Toroidal Code (GTC) and A New Code (ANC) has been formulated for cross-separatrix FRC simulation.In the tokamak edge, turbulent transport in the pedestal of an H-mode DIII-D plasma isstudied via simulations of electrostatic driftwaves. Annulus geometry is used and simulations focus on two radial locations corresponding to the pedestal top with mild pressure gradient and steep pressure gradient. A reactive trapped electron instability with typical ballooning mode structure is excited in the pedestal top. At the steep gradient, the electrostatic instability exhibits unusual mode structure, peaking at poloidal angles theta=+- pi/2. Simulations find this unusual mode structure is due to steep pressure gradients in the pedestal but not due to the particular DIII-D magnetic geometry. Realistic DIII-D geometry has a stabilizing effect compared to a simple circular tokamak geometry.Driftwave instability in FRC is studied for the first time using gyrokinetic simulation. GTCis upgraded to treat realistic equilibrium calculated by an MHD equilibrium code. Electrostatic local simulations in outer closed flux surfaces find ion-scale modes are stable due to the large ion gyroradius and that electron drift-interchange modes are excited by electron temperature gradient and bad magnetic curvature. In the scrape-off layer (SOL) ion-scale modes are excited by density gradient and bad curvature. Collisions have weak effects on instabilities both in the core and SOL. Simulation results are consistent with density fluctuation measurements in the C-2 experiment using Doppler backscattering (DBS). The critical density gradients measured by the DBS qualitatively agree with the linear instability threshold calculated by GTC simulations.One outstanding critical issue in the FRC is the interplay between turbulence in the FRCcore and SOL regions. While the magnetic flux coordinates used by GTC provide a number of computational advantages, they present unique challenges at the magnetic field separatrix. To address this limitation, a new code, capable of coupled core-SOL simulations, is formulated, implemented, and successfully verified.

Subjects/Keywords: Physics; frc; fusion; physics; plasma; simulation; tokamak

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APA (6^th Edition):

Fulton, D. (2015). Kinetic simulation of edge instability in fusion plasmas. (Thesis). University of California – Irvine. Retrieved from http://www.escholarship.org/uc/item/6686z6fg

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Fulton, Daniel. “Kinetic simulation of edge instability in fusion plasmas.” 2015. Thesis, University of California – Irvine. Accessed December 13, 2019. http://www.escholarship.org/uc/item/6686z6fg.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Fulton, Daniel. “Kinetic simulation of edge instability in fusion plasmas.” 2015. Web. 13 Dec 2019.

Vancouver:

Fulton D. Kinetic simulation of edge instability in fusion plasmas. [Internet] [Thesis]. University of California – Irvine; 2015. [cited 2019 Dec 13]. Available from: http://www.escholarship.org/uc/item/6686z6fg.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Fulton D. Kinetic simulation of edge instability in fusion plasmas. [Thesis]. University of California – Irvine; 2015. Available from: http://www.escholarship.org/uc/item/6686z6fg

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Manchester

7. Hanahoe, Kieran. Simulation studies of plasma wakefield acceleration.

Degree: 2018, University of Manchester

URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314401

► Plasma-based accelerators offer the potential to achieve accelerating gradients orders of magnitude higher than are typical in conventional accelerators. A Plasma Accelerator Research Station has… (more)

Subjects/Keywords: Plasma; Accelerator; Simulation; Beam dump; Focusing

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APA (6^th Edition):

Hanahoe, K. (2018). Simulation studies of plasma wakefield acceleration. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314401

Chicago Manual of Style (16^th Edition):

Hanahoe, Kieran. “Simulation studies of plasma wakefield acceleration.” 2018. Doctoral Dissertation, University of Manchester. Accessed December 13, 2019. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314401.

MLA Handbook (7^th Edition):

Hanahoe, Kieran. “Simulation studies of plasma wakefield acceleration.” 2018. Web. 13 Dec 2019.

Vancouver:

Hanahoe K. Simulation studies of plasma wakefield acceleration. [Internet] [Doctoral dissertation]. University of Manchester; 2018. [cited 2019 Dec 13]. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314401.

Council of Science Editors:

Hanahoe K. Simulation studies of plasma wakefield acceleration. [Doctoral Dissertation]. University of Manchester; 2018. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:314401

University of Manchester

8. Hanahoe, Kieran. Simulation studies of plasma wakefield acceleration.

Degree: PhD, 2018, University of Manchester

URL: https://www.research.manchester.ac.uk/portal/en/theses/simulation-studies-of-plasma-wakefield-acceleration(ac0c9742-2aed-493b-8356-e30f3db97e1e).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.748037

► Plasma-based accelerators offer the potential to achieve accelerating gradients orders of magnitude higher than are typical in conventional accelerators. A Plasma Accelerator Research Station has… (more)

Subjects/Keywords: 500; Focusing; Beam dump; Accelerator; Plasma; Simulation

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APA (6^th Edition):

Hanahoe, K. (2018). Simulation studies of plasma wakefield acceleration. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/simulation-studies-of-plasma-wakefield-acceleration(ac0c9742-2aed-493b-8356-e30f3db97e1e).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.748037

Chicago Manual of Style (16^th Edition):

Hanahoe, Kieran. “Simulation studies of plasma wakefield acceleration.” 2018. Doctoral Dissertation, University of Manchester. Accessed December 13, 2019. https://www.research.manchester.ac.uk/portal/en/theses/simulation-studies-of-plasma-wakefield-acceleration(ac0c9742-2aed-493b-8356-e30f3db97e1e).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.748037.

MLA Handbook (7^th Edition):

Hanahoe, Kieran. “Simulation studies of plasma wakefield acceleration.” 2018. Web. 13 Dec 2019.

Vancouver:

Hanahoe K. Simulation studies of plasma wakefield acceleration. [Internet] [Doctoral dissertation]. University of Manchester; 2018. [cited 2019 Dec 13]. Available from: https://www.research.manchester.ac.uk/portal/en/theses/simulation-studies-of-plasma-wakefield-acceleration(ac0c9742-2aed-493b-8356-e30f3db97e1e).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.748037.

Council of Science Editors:

Hanahoe K. Simulation studies of plasma wakefield acceleration. [Doctoral Dissertation]. University of Manchester; 2018. Available from: https://www.research.manchester.ac.uk/portal/en/theses/simulation-studies-of-plasma-wakefield-acceleration(ac0c9742-2aed-493b-8356-e30f3db97e1e).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.748037

University of Ottawa

9. Bart, Graeme. Bridging the Microscopic and Macroscopic Realms of Laser Driven Plasma Dynamics .

Degree: 2018, University of Ottawa

URL: http://hdl.handle.net/10393/38187

► The physical processes shaping laser plasma dynamics take place on length scales ranging from the microscopic (1 ångström) to the macroscopic realms (µm). Microscopic field… (more)

▼ The physical processes shaping laser plasma dynamics take place on length scales ranging from the microscopic (1 ångström) to the macroscopic realms (µm). Microscopic field fluctuations due to the motions of individual plasma charges evolve on an atomic scale. Collisional effects influencing thermalization and ionization processes depend on the plasma fields on an atomic level. Simultaneously, collective processes such as plasma oscillations take place on a mesoscopic length scale of many-nm. The macroscopic realm is ultimately determined by the laser which typically spans hundreds of nm to a few µm. Consequently, ab-initio modelling of laser plasma dynamics requires the resolution of length scales from 1Å to multiple µm. As such, in order to bridge the microscopic and macroscopic length scales of light-matter interaction, in is necessary to account for the individual motions of up to ~10¹¹ particles. This is a not an insignificant undertaking. Until recently, approaches to numerical modelling of light-matter interactions were limited to MD and PIC, each with their own limitations. MicPIC has been developed to fill the gap left by MD and PIC but so far has not been adapted for scalable parallel processing on large distributed memory machines. Thus, its full potential was not able to be fully realized until now. This thesis presents the massively parallel MicPIC method capable of bridging the micro- and macroscopic realms. A wide range of applications that have heretofore not been accessible to theory or, at best, had limited applicability are now open for thorough investigation. Among these are nonlinear nanophotonics, quantum nanophotonics, laser machining, ab-initio dynamics of strongly coupled plasmas, high-harmonic generation, electron and x-ray sources, and optical switching. Two of the first applications of parallel MicPIC to a selection of such problems are shown and discussed below, demonstrating the applicability of the method to a wide variety of newly accessible strong field laser-plasma physics phenomena.

Subjects/Keywords: nonlinear optics; plasma physics; simulation; nanophotonics

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APA (6^th Edition):

Bart, G. (2018). Bridging the Microscopic and Macroscopic Realms of Laser Driven Plasma Dynamics . (Thesis). University of Ottawa. Retrieved from http://hdl.handle.net/10393/38187

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Bart, Graeme. “Bridging the Microscopic and Macroscopic Realms of Laser Driven Plasma Dynamics .” 2018. Thesis, University of Ottawa. Accessed December 13, 2019. http://hdl.handle.net/10393/38187.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Bart, Graeme. “Bridging the Microscopic and Macroscopic Realms of Laser Driven Plasma Dynamics .” 2018. Web. 13 Dec 2019.

Vancouver:

Bart G. Bridging the Microscopic and Macroscopic Realms of Laser Driven Plasma Dynamics . [Internet] [Thesis]. University of Ottawa; 2018. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/10393/38187.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Bart G. Bridging the Microscopic and Macroscopic Realms of Laser Driven Plasma Dynamics . [Thesis]. University of Ottawa; 2018. Available from: http://hdl.handle.net/10393/38187

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Washington

10. Miller, Sean. Modeling collisional processes in plasmas using discontinuous numerical methods.

Degree: PhD, 2016, University of Washington

URL: http://hdl.handle.net/1773/36472

► Fluid-based plasma models are typically applied to parameter regimes where a local thermal equilibrium is assumed. The applicability of this regime is valid for many… (more)

Subjects/Keywords: discontinuous numerical methods; moment models; multi-species; plasma; plasma simulation; Plasma physics; aeronautics and astronautics

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APA (6^th Edition):

Miller, S. (2016). Modeling collisional processes in plasmas using discontinuous numerical methods. (Doctoral Dissertation). University of Washington. Retrieved from http://hdl.handle.net/1773/36472

Chicago Manual of Style (16^th Edition):

Miller, Sean. “Modeling collisional processes in plasmas using discontinuous numerical methods.” 2016. Doctoral Dissertation, University of Washington. Accessed December 13, 2019. http://hdl.handle.net/1773/36472.

MLA Handbook (7^th Edition):

Miller, Sean. “Modeling collisional processes in plasmas using discontinuous numerical methods.” 2016. Web. 13 Dec 2019.

Vancouver:

Miller S. Modeling collisional processes in plasmas using discontinuous numerical methods. [Internet] [Doctoral dissertation]. University of Washington; 2016. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/1773/36472.

Council of Science Editors:

Miller S. Modeling collisional processes in plasmas using discontinuous numerical methods. [Doctoral Dissertation]. University of Washington; 2016. Available from: http://hdl.handle.net/1773/36472

University of Minnesota

11. Mamunuru, Meenakshi. Simulation of DBD plasma actuators, and nanoparticle-plasma interactions in argon-hydrogen CCP RF discharges.

Degree: PhD, Mechanical Engineering, 2014, University of Minnesota

URL: http://hdl.handle.net/11299/167265

► The focus of this work is modeling and simulation of low temperature plasma discharges (LTPs). The first part of the thesis consists of the study… (more)

▼ The focus of this work is modeling and simulation of low temperature plasma discharges (LTPs). The first part of the thesis consists of the study of dielectric barrier (DBD) plasma actuators. Use of DBD plasma actuators on airfoil surfaces is a promising method for increasing airfoil efficiency. Actuators produce a surface discharge that causes time averaged thrust in the neutral gas. The thrust modifies the boundary layer properties of the flow and prevents the occurrence of separation bubbles. In simulating the working of an actuator, the focus is on the spatial characteristics of the thrust produced by the discharge over very short time and space scales. The results provide an understanding of the causes of thrust, and the basic principles behind the actuator operation.The second part of this work focusses on low pressure plasma discharges used for silicon nanoparticle synthesis. When reactive semiconductor precursor gases are passed through capacitively coupled plasma (CCP) radio frequency (RF) reactors, nano sized particles are formed. When the reactors are operated at high enough powers, a very high fraction of the nanoparticles are crystallized in the chamber. Nanoparticle crystallization in plasma is a very complex process and not yet fully understood. It can be inferred from experiments that bulk and surface processes initiated due to energetic ion impaction of the nanoparticles are responsible for reordering of silicon atoms, causing crystallization. Therefore, study of plasma-particle interactions is the first step towards understanding how particles are crystallized. The specific focus of this work is to investigate the experimental evidence that hydrogen gas presence in argon discharges used for silicon nanocrystal synthesis, leads to a superior quality of nanocrystals. Influence of hydrogen gas on plasma composition and discharge characteristics is studied. Via Monte Carlo simulation, distribution of ion energy impacting particles surface is studied. It is seen that hydrogen ions cause a reduction in particle floating potential, thereby lowering the ion impaction energies. The hydrogen ion current is also effective in delivering increased number of atomic H radicals to the particle surface, which are known to promote particle crystallization. The work therefore sheds light on the ways in which trace amount of hydrogen gas participates in silicon nanoparticle crystallization in argon silane plasma.

Subjects/Keywords: Argon hydrogen plasma; Dielectric barrier discharges; Dusty plasma physics; Nanoparticles; Plasma simulation; Mechanical engineering

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APA (6^th Edition):

Mamunuru, M. (2014). Simulation of DBD plasma actuators, and nanoparticle-plasma interactions in argon-hydrogen CCP RF discharges. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/167265

Chicago Manual of Style (16^th Edition):

Mamunuru, Meenakshi. “Simulation of DBD plasma actuators, and nanoparticle-plasma interactions in argon-hydrogen CCP RF discharges.” 2014. Doctoral Dissertation, University of Minnesota. Accessed December 13, 2019. http://hdl.handle.net/11299/167265.

MLA Handbook (7^th Edition):

Mamunuru, Meenakshi. “Simulation of DBD plasma actuators, and nanoparticle-plasma interactions in argon-hydrogen CCP RF discharges.” 2014. Web. 13 Dec 2019.

Vancouver:

Mamunuru M. Simulation of DBD plasma actuators, and nanoparticle-plasma interactions in argon-hydrogen CCP RF discharges. [Internet] [Doctoral dissertation]. University of Minnesota; 2014. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/11299/167265.

Council of Science Editors:

Mamunuru M. Simulation of DBD plasma actuators, and nanoparticle-plasma interactions in argon-hydrogen CCP RF discharges. [Doctoral Dissertation]. University of Minnesota; 2014. Available from: http://hdl.handle.net/11299/167265

Princeton University

12. Shi, Eric Leon. Gyrokinetic Continuum Simulation of Turbulence in Open-Field-Line Plasmas .

Degree: PhD, 2017, Princeton University

URL: http://arks.princeton.edu/ark:/88435/dsp01tt44pq50g

► The properties of the boundary plasma in a tokamak are now recognized to play a key role in determining the achievable fusion power and the… (more)

▼ The properties of the boundary plasma in a tokamak are now recognized to play a key role in determining the achievable fusion power and the lifetimes of plasma-facing components. Accurate quantitative modeling and improved qualitative understanding of the boundary plasma ultimately require five-dimensional gyrokinetic turbulence simulations, which have been successful in predicting turbulence and transport in the core. Gyrokinetic codes for the boundary plasma must be able to handle large-amplitude fluctuations, electromagnetic effects, open and closed magnetic field lines, magnetic X-points, and the dynamics of impurities and neutrals. The additional challenges of boundary-plasma simulation necessitate the development of new gyrokinetic codes or major modifications to existing core gyrokinetic codes. In this thesis, we develop the first gyrokinetic continuum code capable of simulating plasma turbulence on open magnetic field lines, which is a key feature of a tokamak scrape-off layer. In contrast to prior attempts at this problem, we use an energy-conserving discontinuous Galerkin discretization in space. To model the interaction between the plasma and the wall, we design conducting-sheath boundary conditions that permit local currents into and out of the wall. We start by designing spatially one-dimensional kinetic models of parallel SOL dynamics and solve these systems using novel continuum algorithms. By generalizing these algorithms to higher dimensions and adding a model for collisions, we present results from the first gyrokinetic continuum simulations of turbulence on two types of open-field-line systems. The first simulation features uniform and straight field lines, such as found in some linear plasma devices. The second simulation is of a hypothetical model we developed of the NSTX scrape-off layer featuring helical field lines. In the context of discontinuous Galerkin methods, we also explore the use of exponentially weighted polynomials for a more efficient velocity-space discretization of the distribution function when compared to standard polynomials. We show that standard implementations do not conserve any moments of the distribution function, and we develop a modified algorithm that does. These developments comprise a major step towards a gyrokinetic continuum code for quantitative predictions of turbulence and transport in the boundary plasma of magnetic fusion devices. Advisors/Committee Members: Hammett, Gregory W (advisor).

Subjects/Keywords: boundary plasma; discontinuous Galerkin; gyrokinetics; plasma simulation; plasma turbulence; scrape-off layer

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Shi, E. L. (2017). Gyrokinetic Continuum Simulation of Turbulence in Open-Field-Line Plasmas . (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp01tt44pq50g

Chicago Manual of Style (16^th Edition):

Shi, Eric Leon. “Gyrokinetic Continuum Simulation of Turbulence in Open-Field-Line Plasmas .” 2017. Doctoral Dissertation, Princeton University. Accessed December 13, 2019. http://arks.princeton.edu/ark:/88435/dsp01tt44pq50g.

MLA Handbook (7^th Edition):

Shi, Eric Leon. “Gyrokinetic Continuum Simulation of Turbulence in Open-Field-Line Plasmas .” 2017. Web. 13 Dec 2019.

Vancouver:

Shi EL. Gyrokinetic Continuum Simulation of Turbulence in Open-Field-Line Plasmas . [Internet] [Doctoral dissertation]. Princeton University; 2017. [cited 2019 Dec 13]. Available from: http://arks.princeton.edu/ark:/88435/dsp01tt44pq50g.

Council of Science Editors:

Shi EL. Gyrokinetic Continuum Simulation of Turbulence in Open-Field-Line Plasmas . [Doctoral Dissertation]. Princeton University; 2017. Available from: http://arks.princeton.edu/ark:/88435/dsp01tt44pq50g

University of Minnesota

13. Le Picard, Romain. Mechanisms for Nanoparticle Synthesis and Charging in Nonthermal Plasmas.

Degree: PhD, Mechanical Engineering, 2016, University of Minnesota

URL: http://hdl.handle.net/11299/182804

► Nanoparticle formation, charging, and transport in plasmas have been extensively studied due to increasing interest. In the semiconductor industry, dust particles are considered as defects… (more)

▼ Nanoparticle formation, charging, and transport in plasmas have been extensively studied due to increasing interest. In the semiconductor industry, dust particles are considered as defects and are therefore unwanted as they can damage electronic devices during plasma etching or chemical vapor deposition. Potential applications are emerging, including biomedicine or photovoltaics, and require unique particle size and material properties. With the advancement of new technologies, along with a better understanding of particle formation, it is possible to experimentally tailor particle properties as small as 1 nm in diameter. The aim of this thesis is to contribute to the understanding of the mechanisms underlying the formation of nanoparticles in plasmas. A two-dimensional model is developed to self-consistently examine nanoparticle formation, growth, charging, and transport in low-pressure, capacitively-coupled RF flowing plasmas. The experimental set-up modeled is a narrow quartz tube in which a gas mixture of argon-helium-silane flows. The silane dissociation is mostly produced by electron impact due to highly energetic electrons. The nanoparticle cloud is coupled to the plasma. The spatial evolution of the particle size distribution and charge distribution is presented. We show that nanoparticles are mostly negatively charged and pushed along the centerline of the discharge due the ambipolar electric field. However, particles are not trapped in the axial direction, which allows nanoparticles to grow as they flow through the tube. The model predicts the possibility of producing crystalline nanoparticles due to exothermic reactions (e.g., electron-ion recombination and hydrogen reactions) on nanoparticle surfaces. The charging of nanoparticles in plasmas plays a significant role in their growth mechanisms and transport. In a typical parallel plate plasma system, nanoparticles get negatively charged due to collisions with electrons and are trapped at the center of the discharge due to the ambipolar electric field. At small nanoparticle sizes (< 10 nm), the number of electrons that can coexist on a single particle is limited, referred to as particle charge limit. We studied the effect of particle charge limits on charge distributions in low-pressure nonthermal plasmas, by developing an analytical expression for the charge distribution and comparing it with a stochastic charging model. Particle charging plays a significant role in particle transport since charged particles respond to the electric field. Under typical plasma-enhanced chemical vapor deposition conditions, a certain fraction of particles can be neutral or positive and escape the plasma and deposit on the wafer. To better understand and control particle deposition, we studied the effects of ion collisionality with the background neutral gas, electron emission processes, electronegativity, and charge limit on charge distributions. Tailoring particle size and flux to a substrate is possible while using a pulsed plasma. Because particles are mostly negatively…

Subjects/Keywords: Dust Charging; Nonthermal Plasmas; Plasma; Plasma Simulation; Silicon Nanoparticles

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Le Picard, R. (2016). Mechanisms for Nanoparticle Synthesis and Charging in Nonthermal Plasmas. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/182804

Chicago Manual of Style (16^th Edition):

Le Picard, Romain. “Mechanisms for Nanoparticle Synthesis and Charging in Nonthermal Plasmas.” 2016. Doctoral Dissertation, University of Minnesota. Accessed December 13, 2019. http://hdl.handle.net/11299/182804.

MLA Handbook (7^th Edition):

Le Picard, Romain. “Mechanisms for Nanoparticle Synthesis and Charging in Nonthermal Plasmas.” 2016. Web. 13 Dec 2019.

Vancouver:

Le Picard R. Mechanisms for Nanoparticle Synthesis and Charging in Nonthermal Plasmas. [Internet] [Doctoral dissertation]. University of Minnesota; 2016. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/11299/182804.

Council of Science Editors:

Le Picard R. Mechanisms for Nanoparticle Synthesis and Charging in Nonthermal Plasmas. [Doctoral Dissertation]. University of Minnesota; 2016. Available from: http://hdl.handle.net/11299/182804

14. Pechereau, François. Numerical simulation of the interaction of atmospheric pressure plasma discharges with dielectric surfaces : Simulations numériques de l’interaction d’une décharge plasma à pression atmosphérique avec des surfaces diélectriques.

Degree: Docteur es, Energétique, 2013, Châtenay-Malabry, Ecole centrale de Paris

URL: http://www.theses.fr/2013ECAP0077

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Dans cette thèse nous avons étudié l'influence de surfaces diélectriques sur la dynamique de propagation de décharges à pression atmosphérique. Tout d'abord, pour les simulations… (more)

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Dans cette thèse nous avons étudié l'influence de surfaces diélectriques sur la dynamique de propagation de décharges à pression atmosphérique. Tout d'abord, pour les simulations 2D réalisées dans ce travail, nous avons optimisé les performances du code de décharge en utilisant des schémas numériques performants et des techniques de parallélisation. Nous avons ensuite étudié la dynamique de propagation d'une décharge dans l'air à pression atmosphérique dans une géométrie pointe-plan avec un plan diélectrique sur la cathode. Puis, nous avons étudié l'influence d'un obstacle plan diélectrique sur la dynamique de propagation d'une décharge. Nous avons montré que selon les caractéristiques du diélectrique, l'amplitude et la polarité de la tension appliquée, une seconde décharge peut s'initier ou pas dans l'air derrière le diélectrique. La comparaison des résultats avec les expériences a montré que dans une géométrie pointe-plan avec une pointe fine et une tension très élevée, une seule décharge de forme conique est observée. Un bon accord est obtenu sur le diamètre de la décharge et sa vitesse de propagation. Avec un obstacle plan diélectrique entre les électrodes, la dynamique de ré-allumage est plus rapide dans les simulations. Pour améliorer la comparaison avec les expériences, nous avons étudié l'influence de plusieurs processus physico-chimiques. Pour finir, nous avons étudié la dynamique de décharges à pression atmosphérique dans des tubes diélectriques. Pour un mélange He-N2, nous avons montré l'importance des réactions à trois corps. Enfin, nous avons montré l'influence du diamètre du tube sur la structure des décharges dans un mélange He - N2 et dans l'air.

In this Ph.D. thesis, we have carried out 2D numerical simulations to study the influence of dielectric surfaces on the propagation dynamics of plasma discharges at atmospheric pressure. First we have improved the computational efficiency of the discharge code used in this work in implementing parallelization techniques and more efficient numerical schemes. Second we have studied the dynamics of an air discharge at atmospheric pressure in a point-to-plane geometry with a dielectric layer on the cathode plane. Then, we have studied the influence of a dielectric layer obstacle in the inter-electrode gap. We have shown that depending on the characteristics of the dielectric layer and the amplitude and polarity of the applied voltage, a second discharge may reignite or not below the dielectric in the second air gap. The comparison of simulation results with experiments has shown that in a point-to-plane geometry with a sharp point and a high over-voltage, a single conical discharge structure is observed. A good agreement on the discharge diameter and propagation velocity has been obtained. With a dielectric obstacle in the gap, the simulated reignition dynamics is faster than in the experiments. To improve the agreement, we have studied the influence of several physico-chemical processes. Finally, we have studied the dynamics of discharges in dielectric tubes…

Advisors/Committee Members: Bourdon, Anne (thesis director).

Subjects/Keywords: Simulation numérique; Décharge plasma; Pression atmosphérique; Numerical simulation; Plasma discharge; Atmospheric pressure

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Pechereau, F. (2013). Numerical simulation of the interaction of atmospheric pressure plasma discharges with dielectric surfaces : Simulations numériques de l’interaction d’une décharge plasma à pression atmosphérique avec des surfaces diélectriques. (Doctoral Dissertation). Châtenay-Malabry, Ecole centrale de Paris. Retrieved from http://www.theses.fr/2013ECAP0077

Chicago Manual of Style (16^th Edition):

Pechereau, François. “Numerical simulation of the interaction of atmospheric pressure plasma discharges with dielectric surfaces : Simulations numériques de l’interaction d’une décharge plasma à pression atmosphérique avec des surfaces diélectriques.” 2013. Doctoral Dissertation, Châtenay-Malabry, Ecole centrale de Paris. Accessed December 13, 2019. http://www.theses.fr/2013ECAP0077.

MLA Handbook (7^th Edition):

Pechereau, François. “Numerical simulation of the interaction of atmospheric pressure plasma discharges with dielectric surfaces : Simulations numériques de l’interaction d’une décharge plasma à pression atmosphérique avec des surfaces diélectriques.” 2013. Web. 13 Dec 2019.

Vancouver:

Pechereau F. Numerical simulation of the interaction of atmospheric pressure plasma discharges with dielectric surfaces : Simulations numériques de l’interaction d’une décharge plasma à pression atmosphérique avec des surfaces diélectriques. [Internet] [Doctoral dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2013. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2013ECAP0077.

Council of Science Editors:

Pechereau F. Numerical simulation of the interaction of atmospheric pressure plasma discharges with dielectric surfaces : Simulations numériques de l’interaction d’une décharge plasma à pression atmosphérique avec des surfaces diélectriques. [Doctoral Dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2013. Available from: http://www.theses.fr/2013ECAP0077

Université Montpellier II

15. Karishy, Slyman. Theoretical Investigation of Terahertz Collective Oscillations in Electron Devices : Etude théorique des oscillations collectives térahertz dans les dispositifs électroniques.

Degree: Docteur es, Electronique, 2014, Université Montpellier II

URL: http://www.theses.fr/2014MON20164

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L'objectif de cette thèse est d'étudier l'oscillation collective dans un matériau semi-conducteur (InGaAs) dans le but d'élargir les connaissances théoriques et de proposer de nouvelles… (more)

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L'objectif de cette thèse est d'étudier l'oscillation collective dans un matériau semi-conducteur (InGaAs) dans le but d'élargir les connaissances théoriques et de proposer de nouvelles configurations et des structures pour la conception de détecteurs ou émetteurs THz innovants et efficaces. Pour ce faire, nous développons un modèle théorique permettant l'étude de l'oscillation collective soumis ou non à une excitation externe (battement optique ou rayonnements THz). Une attention particulière est faite pour prendre en compte des phénomènes physiques importants tels que la mobilité différentielle dynamique négative et les oscillations de Gunn.Cette étude est faite à travers le développement d'un outil de simulation numérique basé sur l'approche HD couplé à un solveur de Poisson unidimensionnel. Le modèle HD décrit le temps de vol et le mécanisme de diffusion par l'énergie et la vitesse de relaxation. En outre, on prend en compte les frottements et leur évolution, la variation de l'énergie, la vitesse, et la masse effective. Par conséquent, le modèle HD permet l'observation des régimes transitoires ainsi que d'effectuer des études de fréquence. L'influence des différents paramètres physiques et technologiques sur les oscillations et résonances collectives des électrons sont évalués. Ensuite, le régime de petits signaux est étudié et la réponse de la diode aux perturbations optiques et électriques harmoniques et non harmoniques est évaluée. L'influence du fort biais appliqué à la diode sur les processus d'émission et de détection est ensuite décrit.

The purpose of this thesis is to obtain theoretical results in order to propose new configurations and structures for the conception of innovant and efficient THz detectors or emitters. For this sake, we develop a theoretical model allowing the study of collective oscillation in a semiconductor materials (we choose InGaAs), submitted or not to an external excitation (that is to optical beating or THz radiations). A particular attention is payed also to important physical phenomena such as negative dynamic differential mobility and Gunn oscillations.This study is made through the development of numerical simulation tool, which is based on the HD approach coupled to a one-dimensional Poisson solver. The HD model describes the free-flight and scattering mechanism through energy and velocity relaxation rates. Also it takes into account frictions and their evolution, the variation of energy, velocity and effective mass. Hence, the HD model allows us observing the transient regimes and performing frequency studies. The influence of the different physical and technological parameters on the electron collective oscillations and resonances are evaluated. Then, small-signal regime is studied and the diode response to harmonic and non-harmonic optical and electrical perturbations is evaluated. The influence of the high bias applied to the diode on emission and detection processes is then described.

Advisors/Committee Members: Varani, Luca (thesis director), Ajaka, Jassem (thesis director).

Subjects/Keywords: Terahertz; InGaAs; Simulation; Ondes de plasma; Modele hydrodynamique; Terahertz; InGaAs; Simulation; Plasma waves; Hydrodynamic model

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Karishy, S. (2014). Theoretical Investigation of Terahertz Collective Oscillations in Electron Devices : Etude théorique des oscillations collectives térahertz dans les dispositifs électroniques. (Doctoral Dissertation). Université Montpellier II. Retrieved from http://www.theses.fr/2014MON20164

Chicago Manual of Style (16^th Edition):

Karishy, Slyman. “Theoretical Investigation of Terahertz Collective Oscillations in Electron Devices : Etude théorique des oscillations collectives térahertz dans les dispositifs électroniques.” 2014. Doctoral Dissertation, Université Montpellier II. Accessed December 13, 2019. http://www.theses.fr/2014MON20164.

MLA Handbook (7^th Edition):

Karishy, Slyman. “Theoretical Investigation of Terahertz Collective Oscillations in Electron Devices : Etude théorique des oscillations collectives térahertz dans les dispositifs électroniques.” 2014. Web. 13 Dec 2019.

Vancouver:

Karishy S. Theoretical Investigation of Terahertz Collective Oscillations in Electron Devices : Etude théorique des oscillations collectives térahertz dans les dispositifs électroniques. [Internet] [Doctoral dissertation]. Université Montpellier II; 2014. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2014MON20164.

Council of Science Editors:

Karishy S. Theoretical Investigation of Terahertz Collective Oscillations in Electron Devices : Etude théorique des oscillations collectives térahertz dans les dispositifs électroniques. [Doctoral Dissertation]. Université Montpellier II; 2014. Available from: http://www.theses.fr/2014MON20164

16. Benmouffok, Malyk. Caractérisation théorique du plasma lors de l'application d'un courant impulsionnel : application à l'allumage des moteurs : Theoretical characterization of plasma during application of pulsed current profile : application to the ignition of engines.

Degree: Docteur es, Ingénierie des plasmas, 2016, Université Toulouse III – Paul Sabatier

URL: http://www.theses.fr/2016TOU30159

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Le contexte économique et écologique difficile ainsi que la réglementation en matière d'émissions de CO2 poussent les industriels de l'automobile à améliorer les moteurs à… (more)

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Le contexte économique et écologique difficile ainsi que la réglementation en matière d'émissions de CO2 poussent les industriels de l'automobile à améliorer les moteurs à allumage commandé. L'une des voies d'amélioration envisagées est l'admission de mélanges pauvres ou fortement dilués par des gaz d'échappement (EGR) dans la chambre de combustion. La difficulté de ce type de fonctionnement est l'initiation de l'allumage. Afin de pallier ce problème, les systèmes d'allumage sont étudiés et tout particulièrement l'étincelle. Cette décharge est à l'origine de l'apparition d'un plasma et la compréhension des mécanismes impliqués dans le transfert d'énergie entre ce plasma et le gaz réactif environnant est essentielle. Ce travail s'intéresse à la modélisation de l'étincelle dans sa phase d'arc électrique afin de pouvoir prédire le comportement hydrodynamique de l'arc et la propagation de l'onde de choc. Les modèles transitoires bidimensionnels ou tridimensionnels utilisés sont basés sur le logiciel @ANSYS Fluent couplé à des fonctions utilisateurs développées au sein de l'équipe AEPPT. Ils s'appuient dans un premier temps sur la littérature afin de comprendre le comportement général de la décharge, puis sur des configurations expérimentales utilisées dans le cadre du projet ANR FAMAC. Les simulations sont dans un premier temps et en majorité réalisées dans l'air sur des configurations simplifiées de type pointe-pointe afin de valider le modèle. Ensuite, une étude est faite dans une configuration de réacteur où l'arc est généré entre les bornes d'une bougie d'allumage. Le modèle permet de démontrer le rôle de chacun des paramètres initiaux des simulations ainsi que leur impact sur l'écoulement du plasma. L'influence de la prise en compte du champ magnétique est montrée dans le cadre d'un arc impulsionnel nanoseconde. Enfin, le modèle a permis de montrer le rôle d'un écoulement laminaire latéral en direction d'une décharge de type conventionnelle générée par une bobine d'allumage Audi. L'ensemble de ces résultats pourront être le point de départ d'une étude énergétique sur les systèmes d'allumage ainsi que d'une réflexion concernant la compréhension de l'initiation de la combustion.

The economic/ecological context and the CO2 regulation by the "euro" standards lead the automotive industry to improve the spark ignited engines. A way of improvement is the admission of a lean mixture or of a diluted mixture by recirculation of exhaust gases in the combustion chamber. The main difficulty in these conditions is to start the combustion. To overcome this problem, the ignition systems are studied and more particularly the spark. This discharge leads to the apparition of plasma and the understanding of the energy transfer mechanisms between this plasma and the reactive mixture is essential. This work is focus on the modeling of a spark during its electrical arc phase in order to predict the hydrodynamic behavior of the arc and the shock wave propagation. The 2D and 3D transient models are based on ANSYS Fluent coupled with user…

Advisors/Committee Members: Gonzalez, Jean-Jacques (thesis director), Freton, Pierre (thesis director).

Subjects/Keywords: Plasma; Simulation MHD; Etincelle; Allumage; Conditions initiales; Plasma; MHD simulation; Spark; Ignition; Initial conditions

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Benmouffok, M. (2016). Caractérisation théorique du plasma lors de l'application d'un courant impulsionnel : application à l'allumage des moteurs : Theoretical characterization of plasma during application of pulsed current profile : application to the ignition of engines. (Doctoral Dissertation). Université Toulouse III – Paul Sabatier. Retrieved from http://www.theses.fr/2016TOU30159

Chicago Manual of Style (16^th Edition):

Benmouffok, Malyk. “Caractérisation théorique du plasma lors de l'application d'un courant impulsionnel : application à l'allumage des moteurs : Theoretical characterization of plasma during application of pulsed current profile : application to the ignition of engines.” 2016. Doctoral Dissertation, Université Toulouse III – Paul Sabatier. Accessed December 13, 2019. http://www.theses.fr/2016TOU30159.

MLA Handbook (7^th Edition):

Benmouffok, Malyk. “Caractérisation théorique du plasma lors de l'application d'un courant impulsionnel : application à l'allumage des moteurs : Theoretical characterization of plasma during application of pulsed current profile : application to the ignition of engines.” 2016. Web. 13 Dec 2019.

Vancouver:

Benmouffok M. Caractérisation théorique du plasma lors de l'application d'un courant impulsionnel : application à l'allumage des moteurs : Theoretical characterization of plasma during application of pulsed current profile : application to the ignition of engines. [Internet] [Doctoral dissertation]. Université Toulouse III – Paul Sabatier; 2016. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2016TOU30159.

Council of Science Editors:

Benmouffok M. Caractérisation théorique du plasma lors de l'application d'un courant impulsionnel : application à l'allumage des moteurs : Theoretical characterization of plasma during application of pulsed current profile : application to the ignition of engines. [Doctoral Dissertation]. Université Toulouse III – Paul Sabatier; 2016. Available from: http://www.theses.fr/2016TOU30159

17. Martirosyan, Vahagn. Atomistic simulations of H2 and He plasmas modification of thin-films materials for advanced etch processes : Modification de matériaux en couches minces par plasmas H2 ou He : simulations atomistiques pour procédés de gravure innovants.

Degree: Docteur es, Nano electronique et nano technologies, 2017, Grenoble Alpes

URL: http://www.theses.fr/2017GREAT101

► Ce travail de thèse aborde l’un des défis technologiques liés au développement de nouvelles générations de transistors (FinFET, FDSOI), pour lesquels la gravure de couches… (more)

▼ Ce travail de thèse aborde l’un des défis technologiques liés au développement de nouvelles générations de transistors (FinFET, FDSOI), pour lesquels la gravure de couches ultraminces révèle plusieurs problèmes. En particulier, la gravure des espaceurs nitrure (SiN) doit être réalisée avec une précision nanométrique sans endommager les couches sous-jacentes, étape qui ne peut plus être réalisée par des plasmas conventionnels continus. Afin de dépasser cette limitation, une approche innovante a été récemment développée (dite Smart-Etch), qui s’appuie sur l'implantation d’ions légers et se déroule en deux étapes. Premièrement, le matériau à graver est exposé à un plasma ICP ou CCP d’hydrogène (H2) ou d’hélium (He); dans une deuxième étape, la couche modifiée est retirée sélectivement par gravure humide ou exposition à des réactifs gazeux. Afin d’appréhender les mécanismes fondamentaux de la première étape et assister le développement de cette nouvelle technologie, des simulations de dynamique moléculaire (MD) ont été réalisées pour étudier l'interaction des plasmas H2/He avec des couches de Si/SiN. La MD a été utilisée pour examiner comment la modification de ces substrats est affectée par l’énergie ionique, la dose ionique, la composition ionique ou le rapport flux de radicaux/ flux d’ions (dans le cas d’un plasma H2). En accord avec les expériences, les simulations de bombardement ionique He+ ou Hx+ (x = 1-3) sur Si/SiN montrent que l’implantation ionique est auto-limitée, et que l’évolution de la surface se déroule en deux étapes : une rapide modification en volume (sans gravure) suivie d'une saturation lente et de la formation d'une couche implantée stable en régime permanent (état stationnaire). Les mécanismes d'endommagement induit par les ions (rupture des liaisons Si-Si ou Si-N, piégeage/désorption d’He ou H2, formation de groupes SiHx (x = 1-3) en profondeur), sont étudiés et permettent d’apporter de nouveaux éléments de compréhension aux technologies Smart-Cut et Smart-Etch. L’exposition de substrats Si/SiN à un plasma H2 (impacts d’ions Hx+ et de radicaux H) a également été étudiée pour différentes conditions plasma. Dans ce cas, une transformation auto-limitée est observée mais les couches modifiées/hydrogénées sont simultanément gravées pendant l'implantation ionique, à un taux 10 fois inférieur pour SiN par rapport à Si. Les simulations montrent que modifier des substrats Si/SiN avec une précision nanométrique nécessite un contrôle prudent de l’énergie et du flux des ions incidents. En particulier, les faibles doses ioniques doivent être évitées car l’évolution de la surface ne peut pas être contrôlée précisément en régime transitoire (modification rapide). Dans les plasmas H2, les énergies ioniques élevées induisent des couches modifiées plus épaisses mais des taux d'hydrogénation plus faibles et moins homogènes. La composition ionique et le rapport flux de radicaux/ flux ions (Γ) doivent également être controllés avec précaution, notamment car la vitesse de gravure du matériau augmente avec Γ, ce qui… Advisors/Committee Members: Joubert, Olivier Pierre Etienne (thesis director).

Subjects/Keywords: Gravure; Simulation; Dynamique moléculaire; Interaction plasma-Surface; Plasma etching; Simulation; Molecular dynamics; Plasma-Surface interaction; 620

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Martirosyan, V. (2017). Atomistic simulations of H2 and He plasmas modification of thin-films materials for advanced etch processes : Modification de matériaux en couches minces par plasmas H2 ou He : simulations atomistiques pour procédés de gravure innovants. (Doctoral Dissertation). Grenoble Alpes. Retrieved from http://www.theses.fr/2017GREAT101

Chicago Manual of Style (16^th Edition):

Martirosyan, Vahagn. “Atomistic simulations of H2 and He plasmas modification of thin-films materials for advanced etch processes : Modification de matériaux en couches minces par plasmas H2 ou He : simulations atomistiques pour procédés de gravure innovants.” 2017. Doctoral Dissertation, Grenoble Alpes. Accessed December 13, 2019. http://www.theses.fr/2017GREAT101.

MLA Handbook (7^th Edition):

Martirosyan, Vahagn. “Atomistic simulations of H2 and He plasmas modification of thin-films materials for advanced etch processes : Modification de matériaux en couches minces par plasmas H2 ou He : simulations atomistiques pour procédés de gravure innovants.” 2017. Web. 13 Dec 2019.

Vancouver:

Martirosyan V. Atomistic simulations of H2 and He plasmas modification of thin-films materials for advanced etch processes : Modification de matériaux en couches minces par plasmas H2 ou He : simulations atomistiques pour procédés de gravure innovants. [Internet] [Doctoral dissertation]. Grenoble Alpes; 2017. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2017GREAT101.

Council of Science Editors:

Martirosyan V. Atomistic simulations of H2 and He plasmas modification of thin-films materials for advanced etch processes : Modification de matériaux en couches minces par plasmas H2 ou He : simulations atomistiques pour procédés de gravure innovants. [Doctoral Dissertation]. Grenoble Alpes; 2017. Available from: http://www.theses.fr/2017GREAT101

18. Fernando Jaques Ruiz Simôes Junior. Simulação computacional de emissões eletromagnéticas em plasmas espaciais.

Degree: 2008, Instituto Nacional de Pesquisas Espaciais

URL: http://urlib.net/sid.inpe.br/[email protected]/2008/04.22.20.20

► Atualmente sabemos que feixes de elétrons desempenham um importante papel no mecanismo de emissões de rádio que são comumente observadas na região acima do arco… (more)

▼ Atualmente sabemos que feixes de elétrons desempenham um importante papel no mecanismo de emissões de rádio que são comumente observadas na região acima do arco de choque terrestre e explosões solares tipo II e III. Feixes de elétrons que são injetados de volta no vento solar, a partir do arco de choque terrestre, são uma possível fonte das ondas de plasma observadas pelos satélites nesta região. Pesquisas recentes sugerem que múltiplos feixes de elétrons podem ser injetados em um determinado período de tempo. Estes múltiplos feixes tendem a perder suas identidades individuais para formar um único feixe. No arco de choque terrestre, observações têm mostrado que partículas energéticas possuem algum grau de organização na fase de giro. Isto é, a distribuição de velocidades das partículas no plano perpendicular ao campo magnético ambiente depende do ângulo de giro das partículas. Na primeira parte deste trabalho, resolvemos numericamente a relação de dispersão não girotrópica utilizando parâmetros de plasma baseados em medidas observacionais que mostram o agrupamento de fase dos elétrons acima do arco de choque terrestre. A importância da não girotropia na função de distribuição não está completamente compreendida. Para antecipar o comportamento não girotrópico, resolvemos numericamente a relação de dispersão girotrópica paralela que mostra as possíveis regiões de acoplamento quando a não girotropia é introduzida. Encontramos que a não girotropia pode fazer o acoplamento dos modos mesmo quando o sistema é isotrópico. Para uma determinada não girotropia, a taxa de crescimento apresenta dependência na razão entre as freqüências de plasma e ciclotrônica, bem como na anisotropia da temperatura, conhecida como um importante fator na determinação das instabilidades. Na segunda parte deste trabalho utilizamos um código de partículas eletromagnético (KEMPO 1D modificado) para simular dois feixes de elétrons que são injetados no plasma em diferentes instantes de tempo. O primeiro feixe perturba o plasma ambiente introduzindo ondas de Langmuir através de interação feixe de plasma. Em seguida, o outro feixe é injetado no sistema e interage com o primeiro e com as ondas de Langmuir para produzir radiação eletromagnética. As condições iniciais para os feixes de elétrons e para o plasma ambiente são baseadas em observações do vento solar e região do antechoque terrestre. Em nosso modelo, consideramos que o primeiro e o segundo feixe de elétrons, em t=0 , ocupam todo o sistema; isto é necessário para evitar efeitos numéricos nas grades de contorno e permitir a possibilidade de utilizarmos o modelo mais simples. Os resultados mostraram que o primeiro feixe pode produzir harmônicos da freqüência de plasma e o segundo feixe modifica a emissão dos harmônicos gerados pelo primeiro feixe. O segundo feixe de elétrons interage rapidamente com o intenso campo elétrico das ondas de Langmuir fazendo o acoplamento de fase com o primeiro feixe. Um aumento da energia das componentes eletromagnéticas e da energia cinética também é… Advisors/Committee Members: Maria Virgínia Alves, José Augusto Bittencourt, Severino Luiz Guimarães Dutra, Rudi Gaelzer, Jonas Rodrigues de Souza.

Subjects/Keywords: plasma; instabilidade; clima espacial; ondas de plasma; simulação; plasma; instabilities; space weather; plasma waves; computer simulation

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APA (6^th Edition):

Junior, F. J. R. S. (2008). Simulação computacional de emissões eletromagnéticas em plasmas espaciais. (Thesis). Instituto Nacional de Pesquisas Espaciais. Retrieved from http://urlib.net/sid.inpe.br/[email protected]/2008/04.22.20.20

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Junior, Fernando Jaques Ruiz Simôes. “Simulação computacional de emissões eletromagnéticas em plasmas espaciais.” 2008. Thesis, Instituto Nacional de Pesquisas Espaciais. Accessed December 13, 2019. http://urlib.net/sid.inpe.br/[email protected]/2008/04.22.20.20.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Junior, Fernando Jaques Ruiz Simôes. “Simulação computacional de emissões eletromagnéticas em plasmas espaciais.” 2008. Web. 13 Dec 2019.

Vancouver:

Junior FJRS. Simulação computacional de emissões eletromagnéticas em plasmas espaciais. [Internet] [Thesis]. Instituto Nacional de Pesquisas Espaciais; 2008. [cited 2019 Dec 13]. Available from: http://urlib.net/sid.inpe.br/[email protected]/2008/04.22.20.20.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Junior FJRS. Simulação computacional de emissões eletromagnéticas em plasmas espaciais. [Thesis]. Instituto Nacional de Pesquisas Espaciais; 2008. Available from: http://urlib.net/sid.inpe.br/[email protected]/2008/04.22.20.20

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Universidade do Rio Grande do Norte

19. Belisio, Adriano Silva. Simulação da transferência de calor em amostras aquecidas por plasma .

Degree: 2007, Universidade do Rio Grande do Norte

URL: http://repositorio.ufrn.br/handle/123456789/15522

► The processing of materials through plasma has been growing enough in the last times in several technological applications, more specifically in surfaces treatment. That growth… (more)

▼ The processing of materials through plasma has been growing enough in the last times in several technological applications, more specifically in surfaces treatment. That growth is due, mainly, to the great applicability of plasmas as energy source, where it assumes behavior thermal, chemical and/or physical. On the other hand, the multiplicity of simultaneous physical effects (thermal, chemical and physical interactions) present in plasmas increases the complexity for understanding their interaction with solids. In that sense, as an initial step for the development of that subject, the present work treats of the computational simulation of the heating and cooling processes of steel and copper samples immersed in a plasma atmosphere, by considering two experimental geometric configurations: hollow and plane cathode. In order to reach such goal, three computational models were developed in Fortran 90 language: an one-dimensional transient model (1D, t), a two-dimensional transient model (2D, t) and a two-dimensional transient model (2D, t) which take into account the presence of a sample holder in the experimental assembly. The models were developed based on the finite volume method and, for the two-dimensional configurations, the effect of hollow cathode on the sample was considered as a lateral external heat source. The main results obtained with the three computational models, as temperature distribution and thermal gradients in the samples and in the holder, were compared with those developed by the Laboratory of Plasma, LabPlasma/UFRN, and with experiments available in the literature. The behavior showed indicates the validity of the developed codes and illustrate the need of the use of such computational tool in that process type, due to the great easiness of obtaining thermal information of interest Advisors/Committee Members: Lima, João Alves de (advisor), CPF:67514286420 (advisor), http://lattes.cnpq.br/2699729486137957 (advisor), Alves Júnior, Clodomiro (advisor), CPF:09621199468 (advisor), http://lattes.cnpq.br/7441669258580942 (advisor).

Subjects/Keywords: Aquecimento por Plasma; Simulação Numérica; Volumes Finitos; Plasma Heating; Computational Simulation; Finite Volume Method

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APA (6^th Edition):

Belisio, A. S. (2007). Simulação da transferência de calor em amostras aquecidas por plasma . (Thesis). Universidade do Rio Grande do Norte. Retrieved from http://repositorio.ufrn.br/handle/123456789/15522

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Belisio, Adriano Silva. “Simulação da transferência de calor em amostras aquecidas por plasma .” 2007. Thesis, Universidade do Rio Grande do Norte. Accessed December 13, 2019. http://repositorio.ufrn.br/handle/123456789/15522.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Belisio, Adriano Silva. “Simulação da transferência de calor em amostras aquecidas por plasma .” 2007. Web. 13 Dec 2019.

Vancouver:

Belisio AS. Simulação da transferência de calor em amostras aquecidas por plasma . [Internet] [Thesis]. Universidade do Rio Grande do Norte; 2007. [cited 2019 Dec 13]. Available from: http://repositorio.ufrn.br/handle/123456789/15522.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Belisio AS. Simulação da transferência de calor em amostras aquecidas por plasma . [Thesis]. Universidade do Rio Grande do Norte; 2007. Available from: http://repositorio.ufrn.br/handle/123456789/15522

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

UCLA

20. Vafaei-Najafabadi, Navid. Experimental Investigations of Beam Driven Plasma Wakefield Accelerators.

Degree: Electrical Engineering, 2016, UCLA

URL: http://www.escholarship.org/uc/item/2xn3m59r

► A plasma wakefield accelerator (PWFA) uses a plasma wave (a wake) to accelerate electrons at a gradient that is three orders of magnitude higher than… (more)

▼ A plasma wakefield accelerator (PWFA) uses a plasma wave (a wake) to accelerate electrons at a gradient that is three orders of magnitude higher than that of a conventional accelerator. When the plasma wave is driven by a high-density particle beam or a high-intensity laser pulse, it evolves into the nonlinear blowout regime, where the driver expels the background plasma electrons, resulting in an ion cavity forming behind the driver. This ion cavity has ideal properties for accelerating and focusing electrons. One method to insert electrons into this highly-relativistic, transient structure is by ionization injection. In this method, electrons resulting from further ionization of the ions inside the wake are trapped and accelerated by the wakefield. These injected electrons absorb the energy of the wake, resulting in a reduced accelerating field amplitude; this phenomenon is known as beam loading.This thesis discusses experiments that demonstrate how ionization injection can, on the one hand, lead to excessive beam loading and be a detriment to a PWFA, while on the other hand, it may be taken advantage of to produce bright electron beams that will be necessary for applications of a PWFA to a free electron laser (FEL) or a collider. These experiments were part of the FACET Campaign at the SLAC National Accelerator Laboratory and used FACET’s 3 nC, 20.35 GeV electron beam to field ionize the plasma source and drive a wake.In the first experiment, the plasma source was a 30 cm column of rubidium (Rb) vapor. The low ionization potential and high atomic mass of Rb made it a suitable candidate as a plasma source for a PWFA. However, the low ionization potential of the Rb+ ion resulted in continuous ionization of Rb+ and injection of electrons along the length of the plasma. This resulted in heavy beam-loading, which reduced the strength of the accelerating field by half, making the Rb source unusable for a PWFA.In the second experiment, the plasma source was a column of lithium (Li) vapor bound by cold helium (He) gas. Here, the ionization injection of He electrons in the 10 cm boundary region between Li and He led to localized beam loading and resulted in an accelerated electron beam with high energy (32 GeV), a 10% energy spread, and an emittance an order of magnitude smaller than the drive beam. Particle-in-cell simulations indicate that the beam loading can be further optimized by reducing the injection region even more, which can lead to bright, high-current, low-energy-spread electron beams.

Subjects/Keywords: Plasma physics; Physics; Beam loading; Emittance; FACET; SLAC; Ionization injection; Osiris simulation; Plasma Wakefield Accelerator

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APA (6^th Edition):

Vafaei-Najafabadi, N. (2016). Experimental Investigations of Beam Driven Plasma Wakefield Accelerators. (Thesis). UCLA. Retrieved from http://www.escholarship.org/uc/item/2xn3m59r

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Vafaei-Najafabadi, Navid. “Experimental Investigations of Beam Driven Plasma Wakefield Accelerators.” 2016. Thesis, UCLA. Accessed December 13, 2019. http://www.escholarship.org/uc/item/2xn3m59r.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Vafaei-Najafabadi, Navid. “Experimental Investigations of Beam Driven Plasma Wakefield Accelerators.” 2016. Web. 13 Dec 2019.

Vancouver:

Vafaei-Najafabadi N. Experimental Investigations of Beam Driven Plasma Wakefield Accelerators. [Internet] [Thesis]. UCLA; 2016. [cited 2019 Dec 13]. Available from: http://www.escholarship.org/uc/item/2xn3m59r.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Vafaei-Najafabadi N. Experimental Investigations of Beam Driven Plasma Wakefield Accelerators. [Thesis]. UCLA; 2016. Available from: http://www.escholarship.org/uc/item/2xn3m59r

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

UCLA

21. Araki, Samuel Jun. Multi-Scale Multi-Species Modeling for Plasma Devices.

Degree: Aerospace Engineering, 2014, UCLA

URL: http://www.escholarship.org/uc/item/38d4h99p

► This dissertation describes three computational models developed to simulate important aspects of low-temperature plasma devices, most notably ring-cusp ion discharges and thrusters. The main findings… (more)

▼ This dissertation describes three computational models developed to simulate important aspects of low-temperature plasma devices, most notably ring-cusp ion discharges and thrusters. The main findings of this dissertation are related to (1) the mechanisms of cusp confinement for micro-scale plasmas, (2) the implementation and merits of magnetic field aligned meshes, and (3) an improved method for describing heavy species interactions. The Single Cusp (SC) model focuses on the near-cusp region of the discharge chamber to investigate the near surface cusp confinement of a micro-scale plasma. The model employs the multi-species iterative Monte Carlo method and uses various advanced methods such as electric field calculation and particle weighting algorithm that are compatible with a non-uniform mesh in cylindrical coordinates. Three different plasma conditions are simulated with the SC model, including an electron plasma, a sparse plasma, and a weakly ionized plasma. It is found that the scaling of plasma loss to the cusp for a sparse plasma can be similar to that for a weakly ionized plasma, while the loss mechanism is significantly different; the primary electrons strongly influence the loss structure of the sparse plasma. The model is also used, along with experimental results, to describe the importance of the local magnetic field on the primary electron loss behavior at the cusp.Many components of the 2D/3D hybrid fluid/particle model (DC-ION) are improved from the original version. The DC-ION code looks at the macroscopic structure of the discharge plasma and can be used to address the design and optimization challenges of miniature to micro discharges on the order of 3 cm to 1 cm in diameter. Among the work done for DC-ION, detailed steps for the magnetic field aligned (MFA) mesh are provided. Solving the plasma diffusion equation in the ring-cusp configuration, the benefit of the MFA mesh has been fully investigated by comparing the solution with a uniform mesh. It is found that the MFA mesh can still produce a relatively large error due to the misalignment at the domain boundary but still provides a significant improvement in the bulk plasma region. The mesh generation routine can be further improved by enhancing the smoothness of the near-boundary grid elements.The Ion Beam (IB) model is similar to the SC model but primarily focuses on heavy species. The model implements detailed calculation of the heavy species collisions, solving the classical scattering equation with higher order interaction potentials for different collision pairs. A parametric study has been conducted, and the simulation results have shown very good agreement with the experimental results when using an appropriate value for the secondary electron yield. Further study on the elastic collision has shown that the initial atom velocity should not be neglected in order to accurately compute the post-collision CEX ion velocity. The knowledge gained has led to an improvement on the current method by defining an effective elastic collision…

Subjects/Keywords: Aerospace engineering; Plasma physics; Molecular physics; collision; ion thruster; magnet; particle; plasma; simulation

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APA (6^th Edition):

Araki, S. J. (2014). Multi-Scale Multi-Species Modeling for Plasma Devices. (Thesis). UCLA. Retrieved from http://www.escholarship.org/uc/item/38d4h99p

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Araki, Samuel Jun. “Multi-Scale Multi-Species Modeling for Plasma Devices.” 2014. Thesis, UCLA. Accessed December 13, 2019. http://www.escholarship.org/uc/item/38d4h99p.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Araki, Samuel Jun. “Multi-Scale Multi-Species Modeling for Plasma Devices.” 2014. Web. 13 Dec 2019.

Vancouver:

Araki SJ. Multi-Scale Multi-Species Modeling for Plasma Devices. [Internet] [Thesis]. UCLA; 2014. [cited 2019 Dec 13]. Available from: http://www.escholarship.org/uc/item/38d4h99p.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Araki SJ. Multi-Scale Multi-Species Modeling for Plasma Devices. [Thesis]. UCLA; 2014. Available from: http://www.escholarship.org/uc/item/38d4h99p

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – Irvine

22. Taimourzadeh, Sam. Gyrokinetic Simulation of Plasma Instabilities in the DIII-D Tokamak.

Degree: Physics, 2018, University of California – Irvine

URL: http://www.escholarship.org/uc/item/2p51419b

► Fusion energy gives humankind the prospect of nearly unlimited clean energy. To this end future burning plasma experiments are presently under construction, such as the… (more)

▼ Fusion energy gives humankind the prospect of nearly unlimited clean energy. To this end future burning plasma experiments are presently under construction, such as the International Thermonuclear Experimental Reactor (ITER). Two potentially significant challenges for ITER are the effects of Edge Localized Modes (ELMs), and energetic particle (EP) transport. While ELMs are benign in present day experiments, extrapolations to reactor scale predict ELM energy fluxes of up to 20 MJ in fractions of a millisecond, which can drastically decrease divertor lifetimes, generate impurities, and erode first wall components. Moreover, EP transport can affect plasma profiles, beam deposition, and current drive, and can erode reactor walls. Due to the strong coupling of EPs with burning thermal plasmas, plasma confinement properties in the ignition regime are some of the most uncertain factors when extrapolating from existing tokamaks to ITER. This work presents advances in addressing the challenges these mechanisms deliver by making use of gyrokinetic simulations of the DIII-D Tokamak. This thesis presents gyrokinetic simulations of the DIII-D tokamak, via the Gyrokinetic Toroidal Code, with axisymmetric equilibrium show that the reduction in the radial electric field shear at the top of the pedestal during ELM suppression with the n=2 resonant magnetic perturbations (RMPs) leads to enhanced drift-wave turbulence and extended turbulence spreading to the top of the pedestal relative to ELMing plasmas with similar RMP and pedestal parameters. The simulated turbulent transport at the top of the pedestal in ELM suppressed conditions is consistent with experimental observations of enhanced turbulence at the top of the pedestal during ELM suppression by the RMPs. These results suggest that enhanced drift-wave turbulence due to reduced E × B shear at the pedestal top can contribute to the additional transport required to prevent the pedestal growing to a width that is unstable to ELMs. This thesis also reports verification and validation of linear simulations of Alfv́en eigenmodes in the current ramp phase of DIII-D L-mode discharge \#159243 using gyrokinetic, gyrokinetic-MHD hybrid, and eigenvalue codes. The verification and validation for the linear simulations of Alfv́en eigenmodes is the first step to develop an integrated simulation of energetic particles confinement in burning plasmas incorporating multiple physical processes with kinetic effects of both energetic and thermal particles on an equal footing. Using a classical fast ion profile, all simulation codes find that reversed shear Alfv́en eigenmodes (RSAE) are the dominant instability. The real frequencies from all codes have a coefficient of variation of less than 5% for the most unstable modes with toroidal mode number n = 4 and 5. If q_min is adjusted slightly, within experimental errors, an agreement of within 4.5% and 3.1%, for n = 4 and 5 respectively, is found for all codes. The simulated growth rates exhibit greater…

Subjects/Keywords: Plasma physics; alfven eigenmodes; gyrokinetic simulation; plasma physics; radial electric field; rmp turbulence; tokamak

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APA (6^th Edition):

Taimourzadeh, S. (2018). Gyrokinetic Simulation of Plasma Instabilities in the DIII-D Tokamak. (Thesis). University of California – Irvine. Retrieved from http://www.escholarship.org/uc/item/2p51419b

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Taimourzadeh, Sam. “Gyrokinetic Simulation of Plasma Instabilities in the DIII-D Tokamak.” 2018. Thesis, University of California – Irvine. Accessed December 13, 2019. http://www.escholarship.org/uc/item/2p51419b.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Taimourzadeh, Sam. “Gyrokinetic Simulation of Plasma Instabilities in the DIII-D Tokamak.” 2018. Web. 13 Dec 2019.

Vancouver:

Taimourzadeh S. Gyrokinetic Simulation of Plasma Instabilities in the DIII-D Tokamak. [Internet] [Thesis]. University of California – Irvine; 2018. [cited 2019 Dec 13]. Available from: http://www.escholarship.org/uc/item/2p51419b.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Taimourzadeh S. Gyrokinetic Simulation of Plasma Instabilities in the DIII-D Tokamak. [Thesis]. University of California – Irvine; 2018. Available from: http://www.escholarship.org/uc/item/2p51419b

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Washington

23. Jenkins, Nadiah. Breathing Mode Effects on Hall Thruster Plasma Quantities and Channel Wall Power Loss.

Degree: 2019, University of Washington

URL: http://hdl.handle.net/1773/44008

► Breathing mode instabilities, axially-oriented waves between 5-40 kHz, have been observed in Hall thruster operation since the earliest days of experimental research, including their ability… (more)

Subjects/Keywords: breathing mode; hall thruster; numerical simulation; plasma physics; Aerospace engineering; Plasma physics; Aeronautics and astronautics

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APA (6^th Edition):

Jenkins, N. (2019). Breathing Mode Effects on Hall Thruster Plasma Quantities and Channel Wall Power Loss. (Thesis). University of Washington. Retrieved from http://hdl.handle.net/1773/44008

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Jenkins, Nadiah. “Breathing Mode Effects on Hall Thruster Plasma Quantities and Channel Wall Power Loss.” 2019. Thesis, University of Washington. Accessed December 13, 2019. http://hdl.handle.net/1773/44008.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Jenkins, Nadiah. “Breathing Mode Effects on Hall Thruster Plasma Quantities and Channel Wall Power Loss.” 2019. Web. 13 Dec 2019.

Vancouver:

Jenkins N. Breathing Mode Effects on Hall Thruster Plasma Quantities and Channel Wall Power Loss. [Internet] [Thesis]. University of Washington; 2019. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/1773/44008.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Jenkins N. Breathing Mode Effects on Hall Thruster Plasma Quantities and Channel Wall Power Loss. [Thesis]. University of Washington; 2019. Available from: http://hdl.handle.net/1773/44008

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Boston University

24. Young, Matthew Adam. Meter-scale waves in the E-region Ionosphere: cross-scale coupling and variation with altitude.

Degree: PhD, Astronomy, 2019, Boston University

URL: http://hdl.handle.net/2144/37063

► The Sun ionizes a small fraction of Earth's atmosphere above roughly 60 km, producing the plasma that constitutes the ionosphere. Radio signals passing through the… (more)

▼ The Sun ionizes a small fraction of Earth's atmosphere above roughly 60 km, producing the plasma that constitutes the ionosphere. Radio signals passing through the ionosphere scatter off of plasma density structures created by the Farley-Buneman instability (FBI). While numerous studies have characterized the FBI's intrinsic nature, its evolution within the broader context of the surrounding plasma remains enigmatic. This dissertation answers two fundamental questions about the FBI: How does it interact with density gradients? How does its non-linear evolution depend on the background plasma? The fourth chapter examines the combined development of the FBI and the gradient drift instability (GDI) using a 2-D simulation of the equatorial ionosphere. A half-kilometer wave perturbs a plasma layer perpendicular to the ambient magnetic field, causing the perturbed layer to develop GDI waves along the gradient aligned with the ambient electric field, as well as FBI waves in a region where the total electric field exceeds a certain threshold. Early radar observations suggested that these two instabilities were distinct phenomena; the reported results illustrate their coupled nature. The fifth chapter presents 2-D simulations in which a one-kilometer plasma wave develops an electric field large enough to trigger meter-scale waves. Such large-scale waves arise via the GDI within the daytime ionospheric gradient around 100-110 km. Typical ionospheric radars only observe meter-scale irregularities but observations show meter-scale waves tracing out larger structures. Simulated meter-scale FBI in the troughs and crests of kilometer-scale GDI matches radar observations of the daytime equatorial ionosphere, answers a question about electric-field saturation raised by rocket observations in the 1980s, and predicts an anomalous cross-field conductivity important to magnetosphere-ionosphere (M-I) coupling. The sixth chapter of this dissertation presents 3-D simulations of the FBI at a range of altitudes and driving electric fields appropriate to the auroral ionosphere, where it plays a role in M-I coupling. Research has thoroughly established the linear theory of FBI but rigorous analysis of radar measurements requires an understanding of the turbulent stage. These simulations explain the change in instability flow direction with altitude, with regard to the direction of background plasma flow. Advisors/Committee Members: Oppenheim, Meers (advisor).

Subjects/Keywords: Plasma physics; E region; Farley-Buneman; Gradient drift; Ionosphere; Numerical simulation; Plasma instabilities

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Young, M. A. (2019). Meter-scale waves in the E-region Ionosphere: cross-scale coupling and variation with altitude. (Doctoral Dissertation). Boston University. Retrieved from http://hdl.handle.net/2144/37063

Chicago Manual of Style (16^th Edition):

Young, Matthew Adam. “Meter-scale waves in the E-region Ionosphere: cross-scale coupling and variation with altitude.” 2019. Doctoral Dissertation, Boston University. Accessed December 13, 2019. http://hdl.handle.net/2144/37063.

MLA Handbook (7^th Edition):

Young, Matthew Adam. “Meter-scale waves in the E-region Ionosphere: cross-scale coupling and variation with altitude.” 2019. Web. 13 Dec 2019.

Vancouver:

Young MA. Meter-scale waves in the E-region Ionosphere: cross-scale coupling and variation with altitude. [Internet] [Doctoral dissertation]. Boston University; 2019. [cited 2019 Dec 13]. Available from: http://hdl.handle.net/2144/37063.

Council of Science Editors:

Young MA. Meter-scale waves in the E-region Ionosphere: cross-scale coupling and variation with altitude. [Doctoral Dissertation]. Boston University; 2019. Available from: http://hdl.handle.net/2144/37063

Université Paris-Sud – Paris XI

25. Meyrand, Romain. Turbulence à hautes fréquences dans le vent solaire : Modèle magnétohydrodynamique Hall et expériences numériques : High frequency turbulence in the solar wind : Hall magnetohydrodynamic model and numerical experiments.

Degree: Docteur es, Physique des plasmas, 2013, Université Paris-Sud – Paris XI

URL: http://www.theses.fr/2013PA112043

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La turbulence tridimensionnelle se caractérise par sa capacité à transférer de l'énergie des grandes vers les petites échelles où elle est finalement dissipée. Lorsqu’elle se… (more)

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La turbulence tridimensionnelle se caractérise par sa capacité à transférer de l'énergie des grandes vers les petites échelles où elle est finalement dissipée. Lorsqu’elle se produit dans un plasma non-collisionnel comme le vent solaire, une modélisation cinétique semble a priori nécessaire. Toutefois, la complexité d’une telle approche limite les développements théoriques et condamne les expériences numériques à se restreindre à des nombres de Reynolds peu élevés. Dans quelles mesures un modèle mono-fluide comme la MHD Hall permet-il de rendre compte des phénomènes observés dans le vent solaire aux échelles sub-ioniques ? C’est la problématique à laquelle s’est attaquée cette thèse. L’idée directrice de ce travail est de tirer profit de la relative simplicité des modèles fluides et de la puissance algorithmique des méthodes pseudo-spectrales pour aborder la turbulence du vent solaire par des simulations numériques directes tridimensionnelles massivement parallèles à grands nombres de Reynolds. Ces simulations numériques ont permis de mettre en évidence l’existence d’une brisure spontanée de symétrie chirale en turbulence MHD Hall incompressible, ainsi que l’existence d’un nouveau régime appelé ion MHD (IMHD). Un modèle phénoménologique a été proposé pour rendre compte de ces résultats et de nouvelles prédictions ont été faites, puis confirmées numériquement. Enfin, l’étude de l’effet d’un fort champ magnétique uniforme sur la dynamique turbulente a permis de confirmer pour la première fois une ancienne conjecture. L’inertie des électrons a ensuite été prise en compte toujours dans un modèle fluide. Par une approche hydrodynamique classique, une loi universelle a été obtenue pour les fonctions de structure d’ordre trois. L’ensemble de ces résultats est qualitativement en accord avec les mesures in situ du vent solaire et remet en cause le paradigme selon lequel les raidissements successifs du spectre des fluctuations magnétiques sont provoqués nécessairement par des phénomènes d’origine cinétique. De manière plus générale, cette thèse soulève des questions fondamentales sur les processus non-collisionnels de dissipation dans les plasmas turbulents.

Three-dimensional turbulence is characterized by its capacity to transfer energy from large to small scales where it is finally dissipated. When it occurs in a non-collisional plasma like the solar wind, a kinetic modelisation is necessary a priori. The complexity of such an approach however limits the theoretical developments and forces numerical experiments to be restricted to low Reynolds numbers. To what extent does a single-fluid model such as MHD Hall account for the phenomena observed in the solar wind at ion sub-scales ? It is to this question that this thesis tries to answer. The main idea of this work is to take advantage of the relative simplicity of fluid models and of the high precision of pseudo spectral methods to tackle the problem of turbulence in solar wind by direct numerical simulations massively parallelized at high Reynolds numbers. These…

Advisors/Committee Members: Galtier, Sébastien (thesis director).

Subjects/Keywords: MHD Hall; Plasma; Simulation numérique directe; Théorie; Turbulence; Vent solaire; Hall MHD; Plasma; Direct numerical simulation; Theory; Turbulence; Solar wind

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Meyrand, R. (2013). Turbulence à hautes fréquences dans le vent solaire : Modèle magnétohydrodynamique Hall et expériences numériques : High frequency turbulence in the solar wind : Hall magnetohydrodynamic model and numerical experiments. (Doctoral Dissertation). Université Paris-Sud – Paris XI. Retrieved from http://www.theses.fr/2013PA112043

Chicago Manual of Style (16^th Edition):

Meyrand, Romain. “Turbulence à hautes fréquences dans le vent solaire : Modèle magnétohydrodynamique Hall et expériences numériques : High frequency turbulence in the solar wind : Hall magnetohydrodynamic model and numerical experiments.” 2013. Doctoral Dissertation, Université Paris-Sud – Paris XI. Accessed December 13, 2019. http://www.theses.fr/2013PA112043.

MLA Handbook (7^th Edition):

Meyrand, Romain. “Turbulence à hautes fréquences dans le vent solaire : Modèle magnétohydrodynamique Hall et expériences numériques : High frequency turbulence in the solar wind : Hall magnetohydrodynamic model and numerical experiments.” 2013. Web. 13 Dec 2019.

Vancouver:

Meyrand R. Turbulence à hautes fréquences dans le vent solaire : Modèle magnétohydrodynamique Hall et expériences numériques : High frequency turbulence in the solar wind : Hall magnetohydrodynamic model and numerical experiments. [Internet] [Doctoral dissertation]. Université Paris-Sud – Paris XI; 2013. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2013PA112043.

Council of Science Editors:

Meyrand R. Turbulence à hautes fréquences dans le vent solaire : Modèle magnétohydrodynamique Hall et expériences numériques : High frequency turbulence in the solar wind : Hall magnetohydrodynamic model and numerical experiments. [Doctoral Dissertation]. Université Paris-Sud – Paris XI; 2013. Available from: http://www.theses.fr/2013PA112043

Université Paris-Sud – Paris XI

26. Duré, Franck. Etude du plasma secondaire créé dans le neutraliseur d'ITER pour la formation de neutres rapides : Study of the secondary plasma created in the ITER neutralizer for neutral beam injection.

Degree: Docteur es, Physique des plasmas, 2011, Université Paris-Sud – Paris XI

URL: http://www.theses.fr/2011PA112311

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Pour réaliser les conditions des réactions de fusion thermonucléaire dans le tokamak ITER, des moyens additionnels de chauffage sont requis. L'une des principales méthodes pour… (more)

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Pour réaliser les conditions des réactions de fusion thermonucléaire dans le tokamak ITER, des moyens additionnels de chauffage sont requis. L'une des principales méthodes pour chauffer les ions du plasma de coeur sera l'injection de neutres D0 énergétiques. Le neutraliseur est l'étape de l'injecteur de neutres d'ITER où le faisceau de deutérium prend ses propriétés en termes de taux de neutres D0 et de direction de propagation. L'interaction entre le faisceau à 1MeV et le gaz D2 neutralisant (~0.1Pa) crée un plasma secondaire. Les phénomènes physiques en jeu sont présentés à travers l'analyse des résultats du code OBI-2. OBI-2 est un code PIC-MCC (Particle In Cell Monte Carlo Collision) en géométrie cylindrique (2D3V) développé au LPGP qui permet de suivre la propagation du faisceau et les particules du plasma le long du neutraliseur.L'injection de lithium comme cible neutralisante a été étudiée et comparée au deutérium. Une étude paramétrique sur le neutraliseur basé sur le lithium a été réalisée dans la mesure où la longueur et/ou la densité de Li injectée peuvent être modifiées. Le profil de densité de Li a été estimé par le code Monte-Carlo 3D MC-OLIJET développé au LPGP. Le profil résultatnt a été implémenté en entrée du code PIC-MCC. Les résultats montrent la faisabilité du neutraliseur basé sur le lithium, gardant la convergence correcte du faisceau et avec de meilleures performances en termes de durée de vie des cryompompes avant régénération, de neutralisation du faisceau, d'effet de rétrodiffusion des ions positifs.

To achieve thermonuclear fusion reactions in the ITER tokamak, additional heating is required. One of the main method to heat the core plasma ions will be the injection of energetic D0 neutrals. The neutralizer is the stage of the Neutral Beam Injector of ITER where the deuterium beam gets its properties in terms of neutral rate D0 and direction of propagation. The interaction between the 1MeV beam and the D2 neutralizing gas (~0.1Pa) creates a secondary plasma. These physical phenomena involved are presented through the analysis of the OBI-2 code results. OBI-2 is a PIC-MCC (Particle In Cell Monte-Carlo Collision) code in cylindrical geometry (2D3V) developed in the LPGP which allows to follow beam propagation and plasma particles along the neutralizer.The injection of lithium neutralizing target has been investigated and compared to deuterium one. Parametric study of the Li based neutralizer has been performed since the length and/or density of Li injected can be modified. The Li density profile has been estimated through the Monte-Carlo 3D code MC-OLIJET developed in the LPGP. The resulted profile has been implemented as an imput of the PIC-MCC code. Results show the feasibility of a lithium based neutralizer, keeping correct beam focusing and with better performance in terms of cryompump lifetime before regeneration, beam neutralization, positive ion backstreaming effect.

Advisors/Committee Members: Minea, Tiberiu (thesis director).

Subjects/Keywords: Simulation; Neutralizer; ITER; Plasma; PIC - Monte Carlo; Deuterium; Simulation; Neutralizer; ITER; Plasma; PIC - Monte Carlo; Deuterium

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Duré, F. (2011). Etude du plasma secondaire créé dans le neutraliseur d'ITER pour la formation de neutres rapides : Study of the secondary plasma created in the ITER neutralizer for neutral beam injection. (Doctoral Dissertation). Université Paris-Sud – Paris XI. Retrieved from http://www.theses.fr/2011PA112311

Chicago Manual of Style (16^th Edition):

Duré, Franck. “Etude du plasma secondaire créé dans le neutraliseur d'ITER pour la formation de neutres rapides : Study of the secondary plasma created in the ITER neutralizer for neutral beam injection.” 2011. Doctoral Dissertation, Université Paris-Sud – Paris XI. Accessed December 13, 2019. http://www.theses.fr/2011PA112311.

MLA Handbook (7^th Edition):

Duré, Franck. “Etude du plasma secondaire créé dans le neutraliseur d'ITER pour la formation de neutres rapides : Study of the secondary plasma created in the ITER neutralizer for neutral beam injection.” 2011. Web. 13 Dec 2019.

Vancouver:

Duré F. Etude du plasma secondaire créé dans le neutraliseur d'ITER pour la formation de neutres rapides : Study of the secondary plasma created in the ITER neutralizer for neutral beam injection. [Internet] [Doctoral dissertation]. Université Paris-Sud – Paris XI; 2011. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2011PA112311.

Council of Science Editors:

Duré F. Etude du plasma secondaire créé dans le neutraliseur d'ITER pour la formation de neutres rapides : Study of the secondary plasma created in the ITER neutralizer for neutral beam injection. [Doctoral Dissertation]. Université Paris-Sud – Paris XI; 2011. Available from: http://www.theses.fr/2011PA112311

27. Arsénio nunes aleixo viegas, Pedro. Electric field characterization of atmospheric pressure Helium plasma jets through numerical simulations and comparisons with experiments : Étude numérique du champ électrique dans les jets de plasma d’Hélium à pression atmosphérique et comparaisons avec des expériences.

Degree: Docteur es, Physique des plasmas, 2018, Paris Saclay

URL: http://www.theses.fr/2018SACLX061

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Dans cette thèse de doctorat, des simulations numériques basées sur un modèle fluide 2D sont utilisées pour caractériser des jets de plasma d’Hélium pulsés. Le… (more)

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Dans cette thèse de doctorat, des simulations numériques basées sur un modèle fluide 2D sont utilisées pour caractériser des jets de plasma d’Hélium pulsés. Le modèle pour les jets de plasma d’Hélium est développé pour décrire des jets qui s’écoulent dans des atmosphères de N2 et O2 et interagissent avec des cibles. La dynamique de la décharge dans les jets d’Hélium impactant une cible métallique à la masse est analysée pour des polarités positive et négative de la tension appliquée. Les évolutions temporelles et spatiales de champ électrique associées au premier front d’ionisation et au front de rebond sont en bon accord qualitatif avec des mesures récentes de champ électrique. Puis, l’interaction plasma cible entre une décharge positive et une cible diélectrique en BSO est examinée en détail et les résultats sont directement comparés aux expériences. Un bon accord est obtenu entre les simulations et les expériences sur les évolutions temporelles et spatiales de champ électrique. Des valeurs maximales de champ électrique dans la cible de 5 kV.cm−1 ont été obtenues expérimentalement et numériquement. Le champ électrique dans le plasma de l’ordre de quelques dizaines de kV.cm−1 est fortement diminué par le changement de permittivité de la cible. Le champ électrique dans la cible est presque exclusivement dû aux fortes valeurs de charges de surface déposées sur la surface de la cible. Finalement, l’influence des évolutions de champ électrique sur la production d’espèces actives près des cibles est évaluée. On démontre qu’avec des cibles métalliques la synergie entre le premier front et le front de rebond augmente la production d’espèces près de la cible.

In this PhD thesis numerical simulations based on a 2D fluid model are used to characterize pulsed Helium plasma jets. The model for He plasma jets is developed to describe He jets flowing in N2 and O2 atmospheres and interacting with targets. The discharge dynamics in He jets impacting a grounded metallic target is analyzed with both positive and negative polarities of applied voltage. The temporal and spatial evolutions of electric field associated to the first and rebound ionization fronts are in good qualitative agreement with recent electric field measurements. Then, the plasma-target interaction occurring between a positive discharge and a BSO dielectric target is investigated in detail and results are directly compared with experiments. A good agreement is obtained between simulations and experiments concerning the temporal and spatial profiles of electric field. Maximum values of electric field inside the target of 5 kV.cm−1 are found. The high electric field in the plasma of the order of dozens of kV.cm−1 is severely depleted by the change of permittivity. As a result, the electric field experienced inside the target is almost exclusively originated by the high values of surface charge deposited on the target surface. Finally, the influence of the electric field evolutions on the production of chemically active species close to the targets is evaluated. It…

Advisors/Committee Members: Bourdon, Anne (thesis director).

Subjects/Keywords: Jet de plasma; Champ électrique; Hélium; Simulation numérique; Plasma Jet; Electric field; Helium; Numerical simulation; 541.042 4

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Arsénio nunes aleixo viegas, P. (2018). Electric field characterization of atmospheric pressure Helium plasma jets through numerical simulations and comparisons with experiments : Étude numérique du champ électrique dans les jets de plasma d’Hélium à pression atmosphérique et comparaisons avec des expériences. (Doctoral Dissertation). Paris Saclay. Retrieved from http://www.theses.fr/2018SACLX061

Chicago Manual of Style (16^th Edition):

Arsénio nunes aleixo viegas, Pedro. “Electric field characterization of atmospheric pressure Helium plasma jets through numerical simulations and comparisons with experiments : Étude numérique du champ électrique dans les jets de plasma d’Hélium à pression atmosphérique et comparaisons avec des expériences.” 2018. Doctoral Dissertation, Paris Saclay. Accessed December 13, 2019. http://www.theses.fr/2018SACLX061.

MLA Handbook (7^th Edition):

Arsénio nunes aleixo viegas, Pedro. “Electric field characterization of atmospheric pressure Helium plasma jets through numerical simulations and comparisons with experiments : Étude numérique du champ électrique dans les jets de plasma d’Hélium à pression atmosphérique et comparaisons avec des expériences.” 2018. Web. 13 Dec 2019.

Vancouver:

Arsénio nunes aleixo viegas P. Electric field characterization of atmospheric pressure Helium plasma jets through numerical simulations and comparisons with experiments : Étude numérique du champ électrique dans les jets de plasma d’Hélium à pression atmosphérique et comparaisons avec des expériences. [Internet] [Doctoral dissertation]. Paris Saclay; 2018. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2018SACLX061.

Council of Science Editors:

Arsénio nunes aleixo viegas P. Electric field characterization of atmospheric pressure Helium plasma jets through numerical simulations and comparisons with experiments : Étude numérique du champ électrique dans les jets de plasma d’Hélium à pression atmosphérique et comparaisons avec des expériences. [Doctoral Dissertation]. Paris Saclay; 2018. Available from: http://www.theses.fr/2018SACLX061

Université Paris-Sud – Paris XI

28. André, Arnaud. Etude numérique de l’interaction laser-plasma sous dense : de la propagation de l’impulsion au rayonnement émis par les électrons accélérés : Numerical study of the laser-under dense plasma interaction : from the pulse propagation to the radiation emitted by the accelerated electrons.

Degree: Docteur es, Physique, 2012, Université Paris-Sud – Paris XI

URL: http://www.theses.fr/2012PA112098

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Lors de le la propagation d’une impulsion laser ultra- intense et ultra-brève dans un plasma sous dense une onde de plasma se forme dans son… (more)

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Lors de le la propagation d’une impulsion laser ultra- intense et ultra-brève dans un plasma sous dense une onde de plasma se forme dans son sillage, susceptible d’accélérer des électrons à des énergies élevées sur de très courtes distances. Dans un régime d’excitation extrêmement non-linéaire, connu sous le nom de régime de la bulle, on peut obtenir des faisceaux mono-énergétiques d’électrons relativistes. Si les faisceaux d’électrons issus de l’interaction sont aujourd’hui bien caractérisés, de nombreux paramètres de l’interaction restent inaccessibles, faute de diagnostics adaptés. Nous avons tenté de répondre à cette problématique au cours de cette thèse, en étudiant à l’aide de simulations numériques comment interpréter le rayonnement issu de l’interaction pour déterminer la dynamique du milieu.La première partie de l’étude est consacrée aux propriétés du rayonnement des électrons accélérés, qui s’étend jusque dans le domaine des X. L’étude des caractéristiques de l’émission doit pouvoir renseigner sur le mouvement des électrons du milieu et plus généralement sur l’interaction laser-plasma. Les études menées dans le cadre de cette thèse montrent qu’en effet l’observation du rayonnement permet de déterminer la direction des électrons du faisceau en fin d’accélération, et dans une certaine mesure, leur répartition à l’intérieur du faisceau.La deuxième partie concerne la propagation en milieu sous dense. Le plasma perturbe l’impulsion au cours de sa propagation, modifiant ses caractéristiques spatiales et spectrales. Nous avons étudié ces effets lorsque le milieu est constitué d’un gaz d’azote puis d’argon. Nos résultats mettent en évidence les contributions respectives de l’auto-modulation de l’impulsion ainsi que celle du gradient de densité électronique créé par l’ionisation des gaz dans leurs différents états de charge. L’étude a été poursuivie dans des conditions d’accélération exploitant un gaz plus léger et à plus haute intensité, dans le régime de la bulle. Nous avons identifié l’origine des variations des conditions d’interaction observées dans la première partie.

An intense and short laser pulse propagating through an under dense plasma creates a plasma wave in its wake. The huge electric fields generated by this wave are responsible for the acceleration of trapped electrons to high energies in a very short distance. A nonlinear acceleration regime, known as the bubble regime, is particularly exciting as it generates mono-energetic electron beams. Outstanding results have been obtained recently in this thematic. However, while the electron beam itself has been widely characterized, there is still a lack of information concerning the detail of the interaction process itself. During my thesis work, I contribute to bring responses to this problematic, by studying the information carried out by the light emitted during interaction using intensive numerical simulations.The first part of my thesis is the dedicated to the links existing between the properties of accelerated electrons and the radiation they…

Advisors/Committee Members: Monot, Pascal (thesis director).

Subjects/Keywords: Laser; Plasma; Interaction; Accélération; Électron; Propagation; Rayonnement; Betâtron; Simulation; Laser; Plasma; Interaction; Acceleration; Electron; Propagation; Radiation; Betatron; Simulation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

André, A. (2012). Etude numérique de l’interaction laser-plasma sous dense : de la propagation de l’impulsion au rayonnement émis par les électrons accélérés : Numerical study of the laser-under dense plasma interaction : from the pulse propagation to the radiation emitted by the accelerated electrons. (Doctoral Dissertation). Université Paris-Sud – Paris XI. Retrieved from http://www.theses.fr/2012PA112098

Chicago Manual of Style (16^th Edition):

André, Arnaud. “Etude numérique de l’interaction laser-plasma sous dense : de la propagation de l’impulsion au rayonnement émis par les électrons accélérés : Numerical study of the laser-under dense plasma interaction : from the pulse propagation to the radiation emitted by the accelerated electrons.” 2012. Doctoral Dissertation, Université Paris-Sud – Paris XI. Accessed December 13, 2019. http://www.theses.fr/2012PA112098.

MLA Handbook (7^th Edition):

André, Arnaud. “Etude numérique de l’interaction laser-plasma sous dense : de la propagation de l’impulsion au rayonnement émis par les électrons accélérés : Numerical study of the laser-under dense plasma interaction : from the pulse propagation to the radiation emitted by the accelerated electrons.” 2012. Web. 13 Dec 2019.

Vancouver:

André A. Etude numérique de l’interaction laser-plasma sous dense : de la propagation de l’impulsion au rayonnement émis par les électrons accélérés : Numerical study of the laser-under dense plasma interaction : from the pulse propagation to the radiation emitted by the accelerated electrons. [Internet] [Doctoral dissertation]. Université Paris-Sud – Paris XI; 2012. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2012PA112098.

Council of Science Editors:

André A. Etude numérique de l’interaction laser-plasma sous dense : de la propagation de l’impulsion au rayonnement émis par les électrons accélérés : Numerical study of the laser-under dense plasma interaction : from the pulse propagation to the radiation emitted by the accelerated electrons. [Doctoral Dissertation]. Université Paris-Sud – Paris XI; 2012. Available from: http://www.theses.fr/2012PA112098

29. Jorba Ferro, Oriol. Étude de l'influence de la propreté électrostatique du satellite sur les mesures du champ électrique basse fréquence de TARANIS : Study of the influence of the electrostatic cleanliness of the satellite on the measures of the low frequency electric field TARANIS.

Degree: Docteur es, Ingénierie des Plasmas, 2018, Toulouse, ISAE

URL: http://www.theses.fr/2018ESAE0042

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Les satellites en orbite terrestre se déplacent dans le plasma ionosphérique, un mélange de particules chargées, et éventuellement de particules neutres. Des électrons et des… (more)

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Les satellites en orbite terrestre se déplacent dans le plasma ionosphérique, un mélange de particules chargées, et éventuellement de particules neutres. Des électrons et des ions issus de ce plasma, ainsi que les émissions Ultra-Violets(UV) en provenance du soleil, interagissent avec les surfaces du satellite et modifient sa charge électrostatique. Cette chargement peut induire elle-même des décharges électrostatiques aux conséquences allant de perturbations électromagnétiques (fausses commandes par exemple) à la perte du satellite. En orbites de basse altitude (LEO) l'énergie cinétique et thermique du plasma est généralement faible et donc, les satellites vont rarement présenter des décharges importantes. Néanmoins, les missions scientifiques qui embarquent des instruments très performants et précis peuvent être affectées par cette interaction satellite-plasma-émissions UV. Cette thèse s'intéresse particulièrement à ces phénomènes de charge des structures externes du satellite et à l'impact de ce chargement sur les mesures scientifiques effectuées à bord, i.e. mesures du champ électrique et de la densité du plasma thermique.

Earth-orbiting satellites travel in ionospheric plasma, a mixture of charged particles, and possibly neutral particles. Electrons and ions from this plasma, as well as Ultra-Violet (UV) emissions from the sun, interact with the surfaces of the satellite and modify its electrostatic charge. This loading can itself induce electrostatic discharges to the consequences ranging from electromagnetic disturbances (false commands for example) to the loss of the satellite. In low-Earth orbits (LEO), the kinetic and thermal energy of the plasma is generally low and therefore satellites rarely exhibit large discharges. Nevertheless, scientific missions that carry high-performance and accurate instruments can be affected by this satellite-plasma-UV-emissions interaction. This thesis is particularly interested in these phenomena of charge of the external structures of the satellite and the impact of this load on the scientific measurements carried out on board, i.e. measures of the electric field and the density of the thermal plasma.

Advisors/Committee Members: Seran, Elena (thesis director), Hess, Sébastien (thesis director).

Subjects/Keywords: Charge électrostatique du satellite; Méthode df; Simulation numérique; SPIS; Physique des plasmas; Plasma ionosphérique; Spacecraft charging; Df method; Numerical simulation; SPIS; Plasma physics; Ionospheric plasma

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Jorba Ferro, O. (2018). Étude de l'influence de la propreté électrostatique du satellite sur les mesures du champ électrique basse fréquence de TARANIS : Study of the influence of the electrostatic cleanliness of the satellite on the measures of the low frequency electric field TARANIS. (Doctoral Dissertation). Toulouse, ISAE. Retrieved from http://www.theses.fr/2018ESAE0042

Chicago Manual of Style (16^th Edition):

Jorba Ferro, Oriol. “Étude de l'influence de la propreté électrostatique du satellite sur les mesures du champ électrique basse fréquence de TARANIS : Study of the influence of the electrostatic cleanliness of the satellite on the measures of the low frequency electric field TARANIS.” 2018. Doctoral Dissertation, Toulouse, ISAE. Accessed December 13, 2019. http://www.theses.fr/2018ESAE0042.

MLA Handbook (7^th Edition):

Jorba Ferro, Oriol. “Étude de l'influence de la propreté électrostatique du satellite sur les mesures du champ électrique basse fréquence de TARANIS : Study of the influence of the electrostatic cleanliness of the satellite on the measures of the low frequency electric field TARANIS.” 2018. Web. 13 Dec 2019.

Vancouver:

Jorba Ferro O. Étude de l'influence de la propreté électrostatique du satellite sur les mesures du champ électrique basse fréquence de TARANIS : Study of the influence of the electrostatic cleanliness of the satellite on the measures of the low frequency electric field TARANIS. [Internet] [Doctoral dissertation]. Toulouse, ISAE; 2018. [cited 2019 Dec 13]. Available from: http://www.theses.fr/2018ESAE0042.

Council of Science Editors:

Jorba Ferro O. Étude de l'influence de la propreté électrostatique du satellite sur les mesures du champ électrique basse fréquence de TARANIS : Study of the influence of the electrostatic cleanliness of the satellite on the measures of the low frequency electric field TARANIS. [Doctoral Dissertation]. Toulouse, ISAE; 2018. Available from: http://www.theses.fr/2018ESAE0042

University of Colorado

30. Cheng, Jianhua. Implicit hybrid simulation of magnetic reconnection and the ion-temperature-gradient-driven instability.

Degree: PhD, Physics, 2013, University of Colorado

URL: http://scholar.colorado.edu/phys_gradetds/88

► This thesis presents a second-order accurate, semi-implicit δ!f hybrid simulation with Lorentz force ions and fluid electrons. This model includes full ion kinetic effects… (more)

Subjects/Keywords: hybrid simulation; ITG; tearing mode; Plasma and Beam Physics

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APA (6^th Edition):

Cheng, J. (2013). Implicit hybrid simulation of magnetic reconnection and the ion-temperature-gradient-driven instability. (Doctoral Dissertation). University of Colorado. Retrieved from http://scholar.colorado.edu/phys_gradetds/88

Chicago Manual of Style (16^th Edition):

Cheng, Jianhua. “Implicit hybrid simulation of magnetic reconnection and the ion-temperature-gradient-driven instability.” 2013. Doctoral Dissertation, University of Colorado. Accessed December 13, 2019. http://scholar.colorado.edu/phys_gradetds/88.

MLA Handbook (7^th Edition):

Cheng, Jianhua. “Implicit hybrid simulation of magnetic reconnection and the ion-temperature-gradient-driven instability.” 2013. Web. 13 Dec 2019.

Vancouver:

Cheng J. Implicit hybrid simulation of magnetic reconnection and the ion-temperature-gradient-driven instability. [Internet] [Doctoral dissertation]. University of Colorado; 2013. [cited 2019 Dec 13]. Available from: http://scholar.colorado.edu/phys_gradetds/88.

Council of Science Editors:

Cheng J. Implicit hybrid simulation of magnetic reconnection and the ion-temperature-gradient-driven instability. [Doctoral Dissertation]. University of Colorado; 2013. Available from: http://scholar.colorado.edu/phys_gradetds/88

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