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Oregon State University
1.
Boulton, Nicholas M.
Commissioning of the NDDL-40 Neutron Detection System at Oregon State University.
Degree: MS, Radiation Health Physics, 2017, Oregon State University
URL: http://hdl.handle.net/1957/60583 
► The Neutron radiography facility (NRF) at Oregon State University (OSU) has been modified to begin working on the non-destructive evaluation of concrete materials to study…
(more)
▼ The
Neutron radiography facility (NRF) at Oregon State University (OSU) has been modified to begin working on the non-destructive evaluation of concrete materials to study the early stages of shrinkage, cracking, and water transport of concrete during the curing process.
The objective of this work is to investigate the efficiency and spatial resolution of the NDDL 40 Micro-channel plate (MCP) detector for the use of
neutron radiography and tomography with the eventual goal of concrete imaging. Working in collaboration with the School of Civil and Construction Engineering, the NRF at OSU has added a NDDL 40 vacuum sealed
neutron imaging detector with a delay line system readout developed by Nova Scientific Inc. The detector provides leading technology that grants high detector efficiency and high theoretical spatial resolution of ~50 µm which is the major metric for generating both 2D and 3D images. Using the patented technology, the detector uses borated micro-channel plates to convert incoming thermal neutrons through the ¹⁰B(n,α)⁷Li process. This converts the
neutron into an α and lithium ion, which through secondary interaction create an electron avalanche and is amplified to a signal that can be detected.
The NDDL 40 MCP detector has been shown to be capable of producing radiographs and tomography. Through tedious procedures radiographs continually had inconsistent results in image quality due to the dynamic background, signal to noise ratio and dramatically decreased detector efficiency. This led to issues in the rendered tomographic models. Through the extensive measurements and the use of ASTM standards the NDDL-40 MCP detector was determined to have an optimum efficiency of 6% with a maximum spatial resolution of 50 to 200 µm.
Advisors/Committee Members: Reese, Steven (advisor), Yang, Haori (committee member).
Subjects/Keywords: neutron; Neutron radiography – Oregon – Corvallis
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APA (6th Edition):
Boulton, N. M. (2017). Commissioning of the NDDL-40 Neutron Detection System at Oregon State University. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/60583
Chicago Manual of Style (16th Edition):
Boulton, Nicholas M. “Commissioning of the NDDL-40 Neutron Detection System at Oregon State University.” 2017. Masters Thesis, Oregon State University. Accessed January 23, 2019.
http://hdl.handle.net/1957/60583.
MLA Handbook (7th Edition):
Boulton, Nicholas M. “Commissioning of the NDDL-40 Neutron Detection System at Oregon State University.” 2017. Web. 23 Jan 2019.
Vancouver:
Boulton NM. Commissioning of the NDDL-40 Neutron Detection System at Oregon State University. [Internet] [Masters thesis]. Oregon State University; 2017. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1957/60583.
Council of Science Editors:
Boulton NM. Commissioning of the NDDL-40 Neutron Detection System at Oregon State University. [Masters Thesis]. Oregon State University; 2017. Available from: http://hdl.handle.net/1957/60583
Addis Ababa University
2.
Atakalti Belay, Belay.
TEMPERATURE DEPENDENCE VISCOSITY OF THE NEUTRON STAR MATTER
.
Degree: 2012, Addis Ababa University
URL: http://etd.aau.edu.et/dspace/handle/123456789/1422
► In this work, we review the basics of both ideal and non ideal uid dynamics. Funda- mental principles of uid dynamics,solution of nonlinear Boltzmann equation,…
(more)
▼ In this work, we review the basics of both ideal and non ideal
uid dynamics. Funda-
mental principles of
uid dynamics,solution of nonlinear Boltzmann equation, transport
coe cients, and moment transfer, are discussed. To solve the collision integral we have
used the concept of time reversal symmetry. The basic equations governing
uid motion
, energy and momentum are discussed. The in
uence of viscosity and its time and tem-
perature dependency in
uid motion is also discussed. These concepts are then applied
systematically in
Neutron star matter to obtain the general balance equation and to in-
vestigate the motion of
uid particles between two parallel planes moving with a constant
relative velocity . Di erence between ideal and non ideal
uids are discussed.
Advisors/Committee Members: Dr. LEGESSE WETRO (advisor).
Subjects/Keywords: VISCOSITY;
NEUTRON
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APA (6th Edition):
Atakalti Belay, B. (2012). TEMPERATURE DEPENDENCE VISCOSITY OF THE NEUTRON STAR MATTER
. (Thesis). Addis Ababa University. Retrieved from http://etd.aau.edu.et/dspace/handle/123456789/1422
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Atakalti Belay, Belay. “TEMPERATURE DEPENDENCE VISCOSITY OF THE NEUTRON STAR MATTER
.” 2012. Thesis, Addis Ababa University. Accessed January 23, 2019.
http://etd.aau.edu.et/dspace/handle/123456789/1422.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Atakalti Belay, Belay. “TEMPERATURE DEPENDENCE VISCOSITY OF THE NEUTRON STAR MATTER
.” 2012. Web. 23 Jan 2019.
Vancouver:
Atakalti Belay B. TEMPERATURE DEPENDENCE VISCOSITY OF THE NEUTRON STAR MATTER
. [Internet] [Thesis]. Addis Ababa University; 2012. [cited 2019 Jan 23].
Available from: http://etd.aau.edu.et/dspace/handle/123456789/1422.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Atakalti Belay B. TEMPERATURE DEPENDENCE VISCOSITY OF THE NEUTRON STAR MATTER
. [Thesis]. Addis Ababa University; 2012. Available from: http://etd.aau.edu.et/dspace/handle/123456789/1422
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Georgia Tech
3.
Hon, Ryan Paul.
Development of methods and tools for on-the-fly response function generation for criticality calculations.
Degree: PhD, Mechanical Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/58184
► Stochastic Particle Response Calculator, SPaRC, is a new stochastic neutron transport code that has been developed and optimized for the computation of response functions for…
(more)
▼ Stochastic Particle Response Calculator, SPaRC, is a new stochastic
neutron transport code that has been developed and optimized for the computation of response functions for use in response matrix based whole-core transport solvers. SPaRC transports neutrons from a specified fixed source distribution and computes responses as neutrons stream through and then exit regions of interest. The code makes use of both multi-group and continuous energy nuclear data and takes advantage of parallel computing through the message passing interface (MPI). In order to test the
neutron transport routine, various small benchmark problems were solved with SPaRC and compared to results generated with MCNP. Results show excellent agreement between the solutions generated by these codes for both multi-group and continuous energy calculations. The responses generated by SPaRC have been tailored for use in the coarse mesh transport (COMET) method. COMET is a hybrid stochastic/deterministic method shown to compute fast and accurate solutions for a variety of nuclear systems. In order to obtain these solutions, COMET makes use of pre-computed response functions aggregated into a library for use in a deterministic iteration scheme. Previously these response functions were calculated with MCNP and took place before a transport calculation. SPaRC also generates these response functions for use with the COMET method, with the added capability of performing these calculations during the transport routine as needed. This on-the-fly capability for response generation enables the use of the COMET method for calculations where the state of a problem changes with time. SPaRC’s ability to generate responses during a calculation eliminates the need for a fully pre-computed response library to cover the entire possible solution space, extending the capability of COMET to neutronics problems involving multi-physics feedback, such as thermal-hydraulic and depletion calculations. Sample calculations on the reactor assembly level were performed in order to test the accuracy of the SPaRC generated response functions. First, responses were generated for uncontrolled, controlled, and gadded assemblies with both MCNP and SPaRC. Next, COMET calculations were performed using these two sets of responses for the different assembly types in order to generate eigenvalues and pin fission density distributions. The results generated from the MCNP and SPaRC responses agreed within 0.05% for the core eigenvalue and within 0.002% for pin powers. SPaRC is a newly developed fixed-source radiation transport code. The
neutron transport method has been benchmarked against the stochastic transport code MCNP with good agreement and new database management and creation routines have been developed to aid response generation. SPaRC introduces a response function flexibility to the COMET method that facilitates thermal hydraulic and depletion calculations.
Advisors/Committee Members: Rahnema, Farzad (advisor), Petrovic, Bojan (committee member), Zhang, Dingkang (committee member), Chow, Edmond (committee member), Haghighat, Alireza (committee member), Leal, Luiz (committee member).
Subjects/Keywords: Neutron transport
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APA (6th Edition):
Hon, R. P. (2016). Development of methods and tools for on-the-fly response function generation for criticality calculations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58184
Chicago Manual of Style (16th Edition):
Hon, Ryan Paul. “Development of methods and tools for on-the-fly response function generation for criticality calculations.” 2016. Doctoral Dissertation, Georgia Tech. Accessed January 23, 2019.
http://hdl.handle.net/1853/58184.
MLA Handbook (7th Edition):
Hon, Ryan Paul. “Development of methods and tools for on-the-fly response function generation for criticality calculations.” 2016. Web. 23 Jan 2019.
Vancouver:
Hon RP. Development of methods and tools for on-the-fly response function generation for criticality calculations. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1853/58184.
Council of Science Editors:
Hon RP. Development of methods and tools for on-the-fly response function generation for criticality calculations. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/58184
University of Zululand
4.
Lamula, Thobeka Patience.
Cross section measurements for neutron induced reactions on Bi targets using quasi mono-energetic neutron beams of 90 and 140 MeV
.
Degree: 2017, University of Zululand
URL: http://hdl.handle.net/10530/1534
► Cross section measurements for 209Bi(n,3-5n)xBi reactions were performed using quasi-monoenergetic neutron beams of 90 and 140 MeV energies. Neutron beams were produced from the 7Li(p,n)7Be…
(more)
▼ Cross section measurements for 209Bi(n,3-5n)xBi reactions were performed using quasi-monoenergetic
neutron beams of 90 and 140 MeV energies.
Neutron beams were produced from the 7Li(p,n)7Be reaction using the
neutron beam facility of iThemba Laboratory for Accelerator Based Science (LABS).
Neutron activated target materials ( 209Bi) were anal-ysed for gamma-ray emission with the available HPGe gamma-ray detector system of the ERL. From the identi_ed radionuclides, their activities were determined and subsequently their production cross sections were calculated. The cross section data found from this work was compared with the existing experimental as well as the available evaluated data of the International Reactor Dosimetry Fusion File (IRDFF) library. The comparison with
the reported data show good agreement. Currently, other parameters are still outstanding to finalise the comparison and finally conclude the uncertainty components. The cross section data from this work will be important for testing, improving and extending the IRDFF library since the existing experimental data for high energy neutrons are insufficient.To the IRDFF library, the current contribution from iThemba LABS will improve the Bismuth (Bi) data for high threshold energy (n,xn) reactions with cross section peaks located at 90 and 140 MeV energies.
Advisors/Committee Members: Maleka, S.S (advisor), Ntshangase, S.S (advisor), Nchodu, M.R (advisor).
Subjects/Keywords: neutron reactions
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APA (6th Edition):
Lamula, T. P. (2017). Cross section measurements for neutron induced reactions on Bi targets using quasi mono-energetic neutron beams of 90 and 140 MeV
. (Thesis). University of Zululand. Retrieved from http://hdl.handle.net/10530/1534
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lamula, Thobeka Patience. “Cross section measurements for neutron induced reactions on Bi targets using quasi mono-energetic neutron beams of 90 and 140 MeV
.” 2017. Thesis, University of Zululand. Accessed January 23, 2019.
http://hdl.handle.net/10530/1534.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lamula, Thobeka Patience. “Cross section measurements for neutron induced reactions on Bi targets using quasi mono-energetic neutron beams of 90 and 140 MeV
.” 2017. Web. 23 Jan 2019.
Vancouver:
Lamula TP. Cross section measurements for neutron induced reactions on Bi targets using quasi mono-energetic neutron beams of 90 and 140 MeV
. [Internet] [Thesis]. University of Zululand; 2017. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/10530/1534.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lamula TP. Cross section measurements for neutron induced reactions on Bi targets using quasi mono-energetic neutron beams of 90 and 140 MeV
. [Thesis]. University of Zululand; 2017. Available from: http://hdl.handle.net/10530/1534
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
5.
Wang, Xi.
3D Neutron Diffraction Studies on the Vortex Lattice.
Degree: PhD, Physics, 2012, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:297705/
► In condensed matter physics the vortex lattice of type-II superconductors provides a prototype for studying the effect of random pinning on elastic systems. One important…
(more)
▼ In condensed matter physics the vortex lattice of
type-II superconductors provides a prototype for studying the
effect of random pinning on elastic systems. One important problem
is to understand the structural transition from a theoretically
predicted ordered Bragg glass phase to a disordered vortex liquid
phase. Defects, such as screw dislocations, should play an
important role in mediating this order-disorder transition. It is
important to confirm the existence of these defect structures in
the vortex lattice. Experimentally it is difficult to probe the
detailed defect structures inside the vortex lattice. Traditional
methods can only provide information on the surface configuration
or an averaged picture of the bulk behavior of the vortex lattice.
Here we use a novel high-resolution
neutron diffraction technique
to probe the angular orientation of the lattice planes as the flux
lines traverse the atomic crystal. Our results provide structural
evidence for screw dislocations inside the vortex lattice. The
anisotropic defect structure in the underlying atomic lattice
serves as a symmetry breaking field for the vortex lattice. The
strong dependence of the vortex lattice structure on the growth
procedure reveals that the system is metastable and can be
perturbed through thermal cycling to a possible ground state. We
measure the structure of the vortex lattice under different applied
magnetic fields and temperatures to study the interplay between
vortex-vortex interaction, vortex-atomic lattice interaction, and
thermal fluctuations. This high-resolution
neutron diffraction
technique opens up a new way in studying the detailed structure of
the vortex lattice. Our results suggest that the vortex lattice in
low temperature superconductors with anisotropic defects in the
atomic lattice could be an excellent candidate for exploring the
entangled flux liquid phase.
Advisors/Committee Members: Ling, Xinsheng (Director), Kosterlitz, J. (Reader), Mitrovic, Vesna (Reader).
Subjects/Keywords: neutron diffraction
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APA (6th Edition):
Wang, X. (2012). 3D Neutron Diffraction Studies on the Vortex Lattice. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:297705/
Chicago Manual of Style (16th Edition):
Wang, Xi. “3D Neutron Diffraction Studies on the Vortex Lattice.” 2012. Doctoral Dissertation, Brown University. Accessed January 23, 2019.
https://repository.library.brown.edu/studio/item/bdr:297705/.
MLA Handbook (7th Edition):
Wang, Xi. “3D Neutron Diffraction Studies on the Vortex Lattice.” 2012. Web. 23 Jan 2019.
Vancouver:
Wang X. 3D Neutron Diffraction Studies on the Vortex Lattice. [Internet] [Doctoral dissertation]. Brown University; 2012. [cited 2019 Jan 23].
Available from: https://repository.library.brown.edu/studio/item/bdr:297705/.
Council of Science Editors:
Wang X. 3D Neutron Diffraction Studies on the Vortex Lattice. [Doctoral Dissertation]. Brown University; 2012. Available from: https://repository.library.brown.edu/studio/item/bdr:297705/
Kansas State University
6.
Fronk, Ryan G.
Dual-side
etched microstructured semiconductor neutron detectors.
Degree: PhD, Department of Mechanical and
Nuclear Engineering, 2017, Kansas State University
URL: http://hdl.handle.net/2097/35426
► Interest in high-efficiency replacements for thin-film-coated thermal neutron detectors led to the development of single-sided microstructured semiconductor neutron detectors (MSNDs). MSNDs are designed with micro-sized…
(more)
▼ Interest in high-efficiency replacements for
thin-film-coated thermal
neutron detectors led to the development
of single-sided microstructured semiconductor
neutron detectors
(MSNDs). MSNDs are designed with micro-sized trench structures that
are etched into a vertically-oriented pvn-junction diode, and
backfilled with a
neutron converting material, such as ⁶LiF.
Neutrons absorbed by the converting material produce a pair of
charged-particle reaction products that can be measured by the
diode substrate. MSNDs have higher
neutron-absorption and
reaction-product counting efficiencies than their thin-film-coated
counterparts, resulting in up to a 10x increase in intrinsic
thermal
neutron detection efficiency. The detection efficiency for
a single-sided MSND is reduced by
neutron streaming paths between
the conversion-material filled regions that consequently allow
neutrons to pass undetected through the detector. Previously, the
highest reported intrinsic thermal
neutron detection efficiency for
a single MSND was approximately 30%. Methods for double-stacking
and aligning MSNDs to reduce
neutron streaming produced devices
with an intrinsic thermal
neutron detection efficiency of 42%.
Presented here is a new type of MSND that features a complementary
second set of trenches that are etched into the back-side of the
detector substrate. These dual-sided microstructured semiconductor
neutron detectors (DS-MSNDs) have the ability to absorb and detect
neutrons that stream through the front-side, effectively doubling
the detection efficiency of a single-sided device. DS-MSND sensors
are theoretically capable of achieving greater than 80% intrinsic
thermal
neutron detection efficiency for a 1-mm thick device.
Prototype DS-MSNDs with diffused pvp-junction operated at 0-V
applied bias have achieved 53.54±0.61%, exceeding that of the
single-sided MSNDs and double-stacked MSNDs to represent a new
record for detection efficiency for such solid-state
devices.
Advisors/Committee Members: Douglas S. McGregor.
Subjects/Keywords: Neutron;
Radiation; Neutron
detection; Radiation
detection
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APA (6th Edition):
Fronk, R. G. (2017). Dual-side
etched microstructured semiconductor neutron detectors. (Doctoral Dissertation). Kansas State University. Retrieved from http://hdl.handle.net/2097/35426
Chicago Manual of Style (16th Edition):
Fronk, Ryan G. “Dual-side
etched microstructured semiconductor neutron detectors.” 2017. Doctoral Dissertation, Kansas State University. Accessed January 23, 2019.
http://hdl.handle.net/2097/35426.
MLA Handbook (7th Edition):
Fronk, Ryan G. “Dual-side
etched microstructured semiconductor neutron detectors.” 2017. Web. 23 Jan 2019.
Vancouver:
Fronk RG. Dual-side
etched microstructured semiconductor neutron detectors. [Internet] [Doctoral dissertation]. Kansas State University; 2017. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/2097/35426.
Council of Science Editors:
Fronk RG. Dual-side
etched microstructured semiconductor neutron detectors. [Doctoral Dissertation]. Kansas State University; 2017. Available from: http://hdl.handle.net/2097/35426
University of New South Wales
7.
White, Reyner.
Magnetism and Properties of Three Rare Earth Intermetallic Series.
Degree: Physical, Environmental & Mathematical Sciences, 2018, University of New South Wales
URL: http://handle.unsw.edu.au/1959.4/59807
;
https://unsworks.unsw.edu.au/fapi/datastream/unsworks:49839/SOURCE02?view=true
► Three intermetallic series with increasing rare earth dilution are examined and their magnetic and physical properties are determined. Of the first series, RNiAl₄, five materials…
(more)
▼ Three intermetallic series with increasing rare earth dilution are examined and their magnetic and physical properties are determined. Of the first series, RNiAl₄, five materials are examined. For the TbNiAl₄ case, the incommensurate magnetic structure has been determined and then used to rationalise results from previous low temperature nuclear orientation (LTNO) studies. Similarly for NdNiAl₄, a model incommensurate structure has been used to simulate an LTNO experiment. For PrNiAl₄, the presence of an incommensurate magnetic phase has been confirmed and the magnetic structure determined. For ErNiAl₄, the magnetic structure has been charted from well below the ordering temperature to well above it. In DyNiAl₄, two magnetic structures have been identified: a higher temperature incommensurate phase and a lower temperature commensurate phase and these coexist in zero applied field, a first for the series. A reanalysis of existing TbNiAl₄ data has also identified similar phase coexistence. The collective results are used to examine trends across the series.Of the RM₂Al₁₀ series, TbRu₂Al₁₀ has been examined in depth. The material possesses two phase transitions as a function of temperature at TN = 15.0(3) K and TN' = 6.5(3) K and three more as a function of applied field at 2 K, at 1.30(3) T, 1.85(3) T and 3.20(3) T. These metamagnetic transitions transform the low temperature incommensurate square wave structure into two identifiably different 'pulse wave' structures and then to a para/ferromagnetic structure respectively. A magnetic phase diagram has been created and comparisons between TbRu₂Al₁₀ and other RM₂Al₁₀ compounds have been made as well as comparisons with the RNiAl₄ series.For the RM₂Al₂₀ series, three materials were analysed. For NdTi₂Al₂₀, a
neutron diffraction experiment was performed at very low temperatures (70 mK) however no magnetic diffraction peaks were observed. DyTi₂Al₂₀ was
subject to a similar experiment at 30 mK, where a commensurate antiferromagnetic structure was found. For TmV₂Al₂₀, inelastic
neutron scattering was used to determine the crystal field parameters of the Tm³⁺ ion. Improvements were made to the original parameters obtained from bulk measurements, with W = 0.43(1) K and x = -0.63(1) using the Lea, Leask and Wolf formalism.
Advisors/Committee Members: Hutchison, Wayne, Physical, Environmental & Mathematical Sciences, UNSW Canberra, UNSW, Cadogan, Sean, Physical, Environmental & Mathematical Sciences, UNSW Canberra, UNSW.
Subjects/Keywords: Neutron Diffraction; Magnetism; Intermetallics; Inelastic Neutron Scattering
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Manager
APA (6th Edition):
White, R. (2018). Magnetism and Properties of Three Rare Earth Intermetallic Series. (Doctoral Dissertation). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/59807 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:49839/SOURCE02?view=true
Chicago Manual of Style (16th Edition):
White, Reyner. “Magnetism and Properties of Three Rare Earth Intermetallic Series.” 2018. Doctoral Dissertation, University of New South Wales. Accessed January 23, 2019.
http://handle.unsw.edu.au/1959.4/59807 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:49839/SOURCE02?view=true.
MLA Handbook (7th Edition):
White, Reyner. “Magnetism and Properties of Three Rare Earth Intermetallic Series.” 2018. Web. 23 Jan 2019.
Vancouver:
White R. Magnetism and Properties of Three Rare Earth Intermetallic Series. [Internet] [Doctoral dissertation]. University of New South Wales; 2018. [cited 2019 Jan 23].
Available from: http://handle.unsw.edu.au/1959.4/59807 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:49839/SOURCE02?view=true.
Council of Science Editors:
White R. Magnetism and Properties of Three Rare Earth Intermetallic Series. [Doctoral Dissertation]. University of New South Wales; 2018. Available from: http://handle.unsw.edu.au/1959.4/59807 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:49839/SOURCE02?view=true
University of Utah
8.
Moffitt, Gregory Bruce.
Neutron interaction tool, pyNIC for advanced applications in nuclear power, nuclear medicine, and nuclear security.
Degree: MS, Civil & Environmental Engineering, 2014, University of Utah
URL: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3338/rec/1681
► A neutron interaction simulation tool, PyNIC, was developed for the calculation of neutron activation products and prompt gamma ray emission from neutron capture, neutron inelastic…
(more)
▼ A neutron interaction simulation tool, PyNIC, was developed for the calculation of neutron activation products and prompt gamma ray emission from neutron capture, neutron inelastic scattering, and fission interactions. This tool was developed in Python with a graphical user interface to facilitate its easy applications. The tool was validated for neutron activation analysis of a number of samples irradiated in the University of Utah TRIGA Reactor. These samples included nickel wire and the NIST standard for coal fly ash. The experimentally determined isotopes for coal fly ash were 56Mn, 40K, and 139Ba. The samples were irradiated at reactor power levels from 1 kW to 90 kW, and the average percent difference between PyNIC estimated and laboratory measured values was 4%, 24%, 38%, and 22% for 64Ni, 56Mn, 40K, and 139Ba, respectively. These differences are mainly attributed to calibration of the high-purity germanium detector and too short of count times. The PyNIC tool is applicable to neutron activation analysis but also can find its applications in nuclear power, nuclear medicine, and in homeland security such as predicting the contents of explosives and special nuclear materials in samples of complex and unknown origins.
Subjects/Keywords: Activation; Analysis; Neutron
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APA (6th Edition):
Moffitt, G. B. (2014). Neutron interaction tool, pyNIC for advanced applications in nuclear power, nuclear medicine, and nuclear security. (Masters Thesis). University of Utah. Retrieved from http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3338/rec/1681
Chicago Manual of Style (16th Edition):
Moffitt, Gregory Bruce. “Neutron interaction tool, pyNIC for advanced applications in nuclear power, nuclear medicine, and nuclear security.” 2014. Masters Thesis, University of Utah. Accessed January 23, 2019.
http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3338/rec/1681.
MLA Handbook (7th Edition):
Moffitt, Gregory Bruce. “Neutron interaction tool, pyNIC for advanced applications in nuclear power, nuclear medicine, and nuclear security.” 2014. Web. 23 Jan 2019.
Vancouver:
Moffitt GB. Neutron interaction tool, pyNIC for advanced applications in nuclear power, nuclear medicine, and nuclear security. [Internet] [Masters thesis]. University of Utah; 2014. [cited 2019 Jan 23].
Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3338/rec/1681.
Council of Science Editors:
Moffitt GB. Neutron interaction tool, pyNIC for advanced applications in nuclear power, nuclear medicine, and nuclear security. [Masters Thesis]. University of Utah; 2014. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/3338/rec/1681
Johannes Gutenberg Universität Mainz
9.
Siemensen, Christian.
Untersuchung der Ladung des Neutrons.
Degree: 2015, Johannes Gutenberg Universität Mainz
URL: http://ubm.opus.hbz-nrw.de/volltexte/2015/4170/
► Die Quantisierung der elektrischen Ladung ist eine der größten Fragestellungen der Physik, die bis heute nicht verstanden ist. Im Standardmodell der Teilchenphysik ist sie beispielsweise…
(more)
▼ Die Quantisierung der elektrischen Ladung ist eine der größten Fragestellungen der Physik, die bis heute nicht verstanden ist. Im Standardmodell der Teilchenphysik ist sie beispielsweise nicht mathematisch inhärent erklärbar. Dadurch wäre es möglich, dass das Neutron eine winzige Ladung tragen kann. In dieser Arbeit wurde eine Apparatur auf Grundlage eines Vorgängerexperiments entwickelt, mit der eine Untersuchung der Ladung des Neutrons mit höchster Präzision durchgeführt werden kann. Dabei werden ultrakalte Neutronen in einem optischen System einem elektrischen Feld zwischen zwei Elektrodenplatten ausgesetzt. In der ersten Ladungsmessung mit dieser Apparatur konnte eine statistische Sensitivität von δq≈2,4∙10⁻²⁰ e/√d erreicht werden. Diese Sensitivität ist die höchste, die bisher mit ultrakalten Neutronen für eine Ladungsmessung erreicht werden konnte. In dieser Arbeit wurde das Konzept des Vorgängerexperiments grundlegend überarbeitet, um die Sensitivität der Apparatur zu erhöhen. Es wurden detaillierte Untersuchungen der Systematik der Apparatur durchgeführt und das theoretische Potential der Sensitivität von derzeit δq≈10⁻²¹ e/√d ermittelt. Mit dieser Apparatur wurde der Grundstein für die Messung einer neuen niedrigeren oberen Grenze der elektrischen Ladung des Neutrons gelegt. In nächster Zeit kann dadurch eine niedrigere obere Grenze für die Ladung des Neutrons von q≈10⁻²² e erzielt werden.
The quantization of the electric charge is one of the biggest mysteries in physics and not understood until now. In the standard model of particle physics, it is however not mathematically inherent explainable. Thus, the neutron can carry a tiny charge. In this thesis an apparatus was designed to test the neutron electric charge with highest precision. It is based on a former experiment. Ultracold neutrons are exposed to an electric field between two electrodes in an optical system. The first charge measurement with this apparatus yielded a statistical sensitivity of δq≈2,4∙10⁻²⁰ e / √d. This sensitivity is the highest that could be achieved so far with ultracold neutrons for a charge measurement. In this work, the concept of the previous experiment was fundamentally revised in order to increase the sensitivity of the apparatus. Detailed studies of the setup revealed its theoretical sensitivity of currently δq≈10⁻²¹ e / √d. This apparatus is the basis for the measurement of a new lower upper limit of the electric charge of the neutron. In the near future, a lower upper limit for the charge of the neutron of q≈10⁻²² e can be achieved.
Subjects/Keywords: Ladungsquantisierung; UCN; Neutronenoptik; Neutron; Neutronenladung; Electric charge quantisation; UCN; neutron optics; neutron; neutron charge; Physics
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APA (6th Edition):
Siemensen, C. (2015). Untersuchung der Ladung des Neutrons. (Doctoral Dissertation). Johannes Gutenberg Universität Mainz. Retrieved from http://ubm.opus.hbz-nrw.de/volltexte/2015/4170/
Chicago Manual of Style (16th Edition):
Siemensen, Christian. “Untersuchung der Ladung des Neutrons.” 2015. Doctoral Dissertation, Johannes Gutenberg Universität Mainz. Accessed January 23, 2019.
http://ubm.opus.hbz-nrw.de/volltexte/2015/4170/.
MLA Handbook (7th Edition):
Siemensen, Christian. “Untersuchung der Ladung des Neutrons.” 2015. Web. 23 Jan 2019.
Vancouver:
Siemensen C. Untersuchung der Ladung des Neutrons. [Internet] [Doctoral dissertation]. Johannes Gutenberg Universität Mainz; 2015. [cited 2019 Jan 23].
Available from: http://ubm.opus.hbz-nrw.de/volltexte/2015/4170/.
Council of Science Editors:
Siemensen C. Untersuchung der Ladung des Neutrons. [Doctoral Dissertation]. Johannes Gutenberg Universität Mainz; 2015. Available from: http://ubm.opus.hbz-nrw.de/volltexte/2015/4170/
Georgia Tech
10.
Sharma, Ketki.
Electrosorption of ions from aqueous solutions by mesoporous carbon materials.
Degree: PhD, Civil and Environmental Engineering, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/53399
► Electrosorption involves the application of an electrical potential between carbon electrode pairs submerged in brackish water, effectively “trapping” the ions in an electrical double layer…
(more)
▼ Electrosorption involves the application of an electrical potential between carbon electrode pairs submerged in brackish water, effectively “trapping” the ions in an electrical double layer at the solid-liquid interface. Electrosorption has significant applications in environmental engineering, including desalination of water by capacitive deionization (CDI), and in energy storage by supercapacitors. This work combines experimental and modeling studies to investigate the transport and sorption mechanisms of ions in the pores of mesoporous carbon materials that were synthesized at the Oak Ridge National Laboratory (ORNL). The main contribution of this research is examining the effects of operational parameters such as applied potential, solution temperature, ionic concentration, and valence of ions, on the electrosorption behavior of mesoporous carbon materials with the aim to improve the desalination efficiency in the CDI process. It was found that the rates of sorption by mesoporous carbon electrodes and their regeneration increased at a higher temperature and on application of a high-frequency, low-amplitude AC signal.
Neutron imaging has been employed as a tool to visually observe and quantify the transport and distribution of ions within the carbon electrodes. The
neutron images revealed interesting ion transport phenomena that can aid in the optimization of the CDI process. From the ion concentration profiles inside the electrodes, the effective diffusivities of gadolinium and lithium ions were obtained under various conditions of applied potential. Information on the diffusivity of ions can aid in theoretical modeling of the CDI process as well as guide strategies for the design of advanced electrode materials. In the final part of the study, the extraction of salinity gradient energy or ‘blue energy’ by mixing fluids of different salinities was assessed based on the principle of capacitive double layer expansion.
Neutron imaging of blue energy recovery cycles was conducted to observe the ion transport behavior during the various steps of the cycle. The results obtained provide insights into the fundamental ion transport mechanisms during electrosorption by mesoporous carbon materials. This research has important implications for developing advanced system designs for desalination of saline water and energy storage devices.
Advisors/Committee Members: Yiacoumi, Sotira (advisor), Tsouris, Costas (committee member), Pavlostathis, Spyros G. (committee member), Payne, Christine (committee member), Huang, Ching-Hua (committee member).
Subjects/Keywords: Electrosorption; Neutron imaging
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APA (6th Edition):
Sharma, K. (2014). Electrosorption of ions from aqueous solutions by mesoporous carbon materials. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53399
Chicago Manual of Style (16th Edition):
Sharma, Ketki. “Electrosorption of ions from aqueous solutions by mesoporous carbon materials.” 2014. Doctoral Dissertation, Georgia Tech. Accessed January 23, 2019.
http://hdl.handle.net/1853/53399.
MLA Handbook (7th Edition):
Sharma, Ketki. “Electrosorption of ions from aqueous solutions by mesoporous carbon materials.” 2014. Web. 23 Jan 2019.
Vancouver:
Sharma K. Electrosorption of ions from aqueous solutions by mesoporous carbon materials. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1853/53399.
Council of Science Editors:
Sharma K. Electrosorption of ions from aqueous solutions by mesoporous carbon materials. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53399
Georgia Tech
11.
Benson, Bixler C.
Feasibility of creating a neutron detector array for the detection of special nuclear materials.
Degree: MS, Mechanical Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/60397
► The purpose of this research is to determine the feasibility of creating an energy-dependent neutron detector array that could be used to detect special nuclear…
(more)
▼ The purpose of this research is to determine the feasibility of creating an energy-dependent
neutron detector array that could be used to detect special nuclear materials. The proposed detector array is composed of idealized thermal
neutron detectors covered by moderators of differing size, namely thickness and shape. Through a series of Monte Carlo radiation transport calculations, the size, shape, and location of the moderators and detectors were configured to determine the efficacy of obtaining a
neutron energy spectrum or spectral information in a single measurement. This approach expands on the concepts of the Bonner Sphere Spectrometer (BSS) which relies on multiple measurements using differing size moderating spheres. Although a proven approach, the traditional BSS method is not practicable for military applications. The alternative approach to the spectrum measurement is the use of detector sums or ratios to distinguish fission
neutron spectra from other
neutron spectra that might be encountered. Several 5x5 detector/moderator arrays were modeled in MCNP to determine which models would have the best responses to monoenergetic
neutron sources. Five models of 5x5 detector arrays were chosen that best optimize the detectors reaction rates over certain energy ranges. This 5x25 detector array was then simulated with monoenergetic
neutron sources and fission sources. A least squares fitting method was attempted to find coefficients that would generate a weighted sum of detectors that yield a flat fluence response. The response function did not have a flat response. The 5x25 detector system did produce characteristic curves for moderated and unmoderated fission sources. A 5x30 detector array that contained a 5x5 detector array that had a beryllium layer was also simulated. The 5x30 detector array had a higher response to high energy neutrons, but not a significant increase for low energy neutrons. The resulting 5x25 system that was designed is capable of being vehicle mounted so it would be mobile. This research shows that it is feasible to create a
neutron detector array that is sensitive to
neutron energy spectra.
Advisors/Committee Members: Hertel, Nolan (advisor), Wang, Chris (committee member), Shannon, Michael (committee member).
Subjects/Keywords: Neutron detection; MCNP
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APA (6th Edition):
Benson, B. C. (2015). Feasibility of creating a neutron detector array for the detection of special nuclear materials. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60397
Chicago Manual of Style (16th Edition):
Benson, Bixler C. “Feasibility of creating a neutron detector array for the detection of special nuclear materials.” 2015. Masters Thesis, Georgia Tech. Accessed January 23, 2019.
http://hdl.handle.net/1853/60397.
MLA Handbook (7th Edition):
Benson, Bixler C. “Feasibility of creating a neutron detector array for the detection of special nuclear materials.” 2015. Web. 23 Jan 2019.
Vancouver:
Benson BC. Feasibility of creating a neutron detector array for the detection of special nuclear materials. [Internet] [Masters thesis]. Georgia Tech; 2015. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1853/60397.
Council of Science Editors:
Benson BC. Feasibility of creating a neutron detector array for the detection of special nuclear materials. [Masters Thesis]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/60397
Colorado School of Mines
12.
Wilson, Clinton R.
Beamline improvements to the MInes NEutron Radiography (MINER) facility.
Degree: MS(M.S.), Metallurgical and Materials Engineering, 2017, Colorado School of Mines
URL: http://hdl.handle.net/11124/170599
► The Colorado School of Mines designed and installed a neutron radiography system at the United States Geological Survey TRIGA reactor (GSTR) in 2012. Several potential…
(more)
▼ The Colorado School of Mines designed and installed a
neutron radiography system at the United States Geological Survey TRIGA reactor (GSTR) in 2012. Several potential improvements to this system have since been identified, particularly with respect to the
neutron beamline. This thesis details the design of a new beamline to address some of the drawbacks of the present system. Computational analysis using MCNP determined that a 7.32 m long, un-lined, square aluminum beam tube with a 1 m circular pre-collimator produces a
neutron beam with a lower divergence than an equal length collimator that has a
neutron absorbing liner and no pre-collimator. The placement of graphite around the pre-collimator can boost beam intensity by up to 15%. The new beamstop will require an additional 720 kg shielding to keep the radiation dose rates comparable to the present beamline. Structural analysis also showed that the new beamline design has a smaller tendency to bend (by ~90%) than the current tube, and has a maximum buoyant force of 29.5 kg that will need to be overcome through the addition of ballast.
Advisors/Committee Members: King, Jeffrey C. (advisor), Greife, Uwe (committee member), Deinert, Mark R. (committee member).
Subjects/Keywords: Neutron; Beamline; Radiography
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APA (6th Edition):
Wilson, C. R. (2017). Beamline improvements to the MInes NEutron Radiography (MINER) facility. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/170599
Chicago Manual of Style (16th Edition):
Wilson, Clinton R. “Beamline improvements to the MInes NEutron Radiography (MINER) facility.” 2017. Masters Thesis, Colorado School of Mines. Accessed January 23, 2019.
http://hdl.handle.net/11124/170599.
MLA Handbook (7th Edition):
Wilson, Clinton R. “Beamline improvements to the MInes NEutron Radiography (MINER) facility.” 2017. Web. 23 Jan 2019.
Vancouver:
Wilson CR. Beamline improvements to the MInes NEutron Radiography (MINER) facility. [Internet] [Masters thesis]. Colorado School of Mines; 2017. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/11124/170599.
Council of Science Editors:
Wilson CR. Beamline improvements to the MInes NEutron Radiography (MINER) facility. [Masters Thesis]. Colorado School of Mines; 2017. Available from: http://hdl.handle.net/11124/170599
University of Illinois – Urbana-Champaign
13.
Myers, Luke S.
Deuteron compton scattering below pion threshold.
Degree: PhD, 0240, 2011, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/18332
► A series of experiments were performed at the Tagged Photon Facility at MAX-lab in Lund, Sweden to study photon scattering from the deuteron and extract…
(more)
▼ A series of experiments were performed at the Tagged Photon Facility at MAX-lab in Lund, Sweden to study photon scattering from the deuteron and extract the
neutron polarizabilities. The deuteron Compton scattering cross section was measured at laboratory angles of 60
o, 120
o, and 150
o for photon energies from 70 - 112 MeV. The photons were scattered from the Lund liquid deuterium target and detected in three large (20'' x 20'') NaI photon spectrometers. These detectors have sufficient energy resolution (∼2% at 100 MeV) to separate the elastically and inelastically scattered photons.
The extracted scattering cross section for this experiment was found to have angular distributions that matched prior experiments but needed a scaling factor to bring the absolute cross section into agreement. This scaling factor was determined to have a value of 1.47 ± 0.10. Suggestions are made for future studies that could yield further knowledge of the scaling factor and potentially allow for this data to be re-normalized.
Advisors/Committee Members: Nathan, Alan M. (advisor), Hertzog, David W. (Committee Chair), Nathan, Alan M. (committee member), Stack, John D. (committee member), Mestre, Jose P. (committee member).
Subjects/Keywords: Neutron; Isoscalar; Polarizability
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APA (6th Edition):
Myers, L. S. (2011). Deuteron compton scattering below pion threshold. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/18332
Chicago Manual of Style (16th Edition):
Myers, Luke S. “Deuteron compton scattering below pion threshold.” 2011. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed January 23, 2019.
http://hdl.handle.net/2142/18332.
MLA Handbook (7th Edition):
Myers, Luke S. “Deuteron compton scattering below pion threshold.” 2011. Web. 23 Jan 2019.
Vancouver:
Myers LS. Deuteron compton scattering below pion threshold. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2011. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/2142/18332.
Council of Science Editors:
Myers LS. Deuteron compton scattering below pion threshold. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2011. Available from: http://hdl.handle.net/2142/18332
RMIT University
14.
Keehan, S.
Risks posed by neutron contamination in high energy radiotherapy.
Degree: 2017, RMIT University
URL: http://researchbank.rmit.edu.au/view/rmit:162207
► Radiotherapy is a common cancer treatment which aims to use radiation energy to kill tumour cells without damaging healthy tissue. High energy x-rays penetrate tissue…
(more)
▼ Radiotherapy is a common cancer treatment which aims to use radiation energy to kill tumour cells without damaging healthy tissue. High energy x-rays penetrate tissue deeply, depositing most of their energy beyond the skin and shallow tissues. X-rays with energies above 8 MeV may interact to produce neutrons, to which the patient is then exposed. Treatment planning systems (TPS), which calculate the amount of energy deposited to biological structures, do not currently account for contaminant neutrons produced in high energy interactions. Constant improvements in modern radiotherapy techniques have resulted in better patient life expectancy than ever before. The unfortunate corollary of increased life span is increased manifestation of late onset side effects from low dose radiation exposure. This has resulted in an increased drive to reduce the dose to untargeted tissues as much as possible. A perfect treatment plan delivers a prescribed dose to the target volume and no dose to any other tissue. In reality, there is always some tissue through which the radiation must pass in order to reach the target, and some energy which passes beyond the intended target volume. In addition, there is unavoidable scattering of radiation within the patient, which results in out-of-field doses to untargeted tissue. Dose to untargeted tissues resulting from x-ray energy is relatively well understood and is calculated and reported by TPS. Dose resulting from contaminant neutrons is not currently considered by TPS. The overall number of neutrons produced is relatively low, because high energy x-rays may interact in a variety ways and reactions producing neutrons are generally less likely. However, energy deposited by radiation can produce different biological outcomes depending on the type of radiation which deposits the energy. The biological damage inflicted by neutron radiation depends on the energy of the neutrons, and neutrons with energy around 1 MeV may be up to 20 times more damaging than x-rays. So, how do we know the risk associated with neutrons produced from high energy x-rays? Measure the number of neutrons produced? Measure the amount of energy they deposit? Neutron radiation is incredibly difficult to quantify, much more so than alpha, beta, x-ray, gamma or proton radiation. Neutrons are neutrally charged particles, which means they are not attracted or repelled by the positive nuclei or negative electrons which make up all matter. Neutrons primarily pass straight through most materials without leaving a trace of evidence. This makes them quite difficult to detect! Neutrons do interact with the nuclei of some materials, in nuclear reactions, which produce energy and secondary particles which can more easily be detected. The extra energy released in these interactions and their complex probability functions make it difficult to determine the number of neutrons or the energy they would release in human tissue. The high uncertainty in neutron measurement techniques has resulted in some controversy around the use of…
Subjects/Keywords: Fields of Research; Neutron; Radiotherapy; Neutron detection; Neutron dosimetry; Activation
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APA (6th Edition):
Keehan, S. (2017). Risks posed by neutron contamination in high energy radiotherapy. (Thesis). RMIT University. Retrieved from http://researchbank.rmit.edu.au/view/rmit:162207
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Keehan, S. “Risks posed by neutron contamination in high energy radiotherapy.” 2017. Thesis, RMIT University. Accessed January 23, 2019.
http://researchbank.rmit.edu.au/view/rmit:162207.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Keehan, S. “Risks posed by neutron contamination in high energy radiotherapy.” 2017. Web. 23 Jan 2019.
Vancouver:
Keehan S. Risks posed by neutron contamination in high energy radiotherapy. [Internet] [Thesis]. RMIT University; 2017. [cited 2019 Jan 23].
Available from: http://researchbank.rmit.edu.au/view/rmit:162207.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Keehan S. Risks posed by neutron contamination in high energy radiotherapy. [Thesis]. RMIT University; 2017. Available from: http://researchbank.rmit.edu.au/view/rmit:162207
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Stellenbosch University
15.
Singo, Thifhelimbilu Daphney.
Development of a high flux neutron radiation detection system for in-core temperature monitoring.
Degree: PhD, Physics, 2012, Stellenbosch University
URL: http://hdl.handle.net/10019.1/19999
► ENGLISH ABSTRACT: The objective of this research was to develop a neutron detection system that incorporates a mass spectrometer to measure high neutron flux in…
(more)
▼ ENGLISH ABSTRACT: The objective of this research was to develop a
neutron detection system that
incorporates a mass spectrometer to measure high
neutron flux in a nuclear
reactor environment. This system consists of slow and fast
neutron detector
elements for measuring fluxes in those energy regions respectively. The detector
should further be capable of withstanding the harsh conditions associated
with a high temperature reactor. This novel detector which was initially intended
for use in the PBMR reactor has possible applications as an in-core
neutron and indirect temperature-monitoring device in any of the HTGR.
Simulations of a generic HTGR core model were performed in order to
obtain the
neutron energy spectrum with emphasis on the behavior of three
energy regions, slow, intermediate and fast neutrons within the core at different
temperatures. The slow
neutron flux which has the characteristic of a Maxwell-
Boltzmann distribution were found to shift to larger values of
neutron flux
at higher energies as the fuel temperature increased, while fast
neutron flux
spectra remained relatively constant. In addition, the results of the fit of
the slow
neutron flux with a modified Maxwell-Boltzmann equation confirmed
that in the presence of the
neutron source, leakage and absorption, the effective
neutron temperatures is above the medium temperatures. From these results,
it was clear that the detection system will need to monitor both slow and
fast
neutron flux. Placing
neutron detectors inside the reactor core, that are
sensitive to a particular energy range of slow and fast neutrons, would thus
provide information about the change of temperature in the fuel and hence act
as an in-core temperature monitor.
A detection mechanism was developed that employs the
neutron-induced
break-up reaction of 6Li and 12C into α-particles. These materials make excellent
neutron converters without interference due to γ-rays, as the contributions
from 6Li(γ,np)4He and 12C(γ,3α) reactions are negligible. The mass spectrometer
measures the 4He partial pressure as a function of time under high vacuum
with the help of pressure gradient provided by a high-vacuum turbomolecular
pump and a positive-displacement fore-vacuum pump connected in series. A
cryogenic trap, which contains a molecular sieve made of pellets 1.6 mm in diameter,
was also designed and manufactured to remove impurities which cause
a background in the lighter mass region of the spectrum.
The development and testing of the high flux
neutron detection system
were performed at the iThemba Laboratory for Accelerator Based Sciences
(LABS), South Africa. These tests were carried out with a high energy proton
beam at the D-line
neutron facility, and with a fast
neutron beam at the
neutron radiation therapy facility. To test the principle and capability of the
detection system in measuring high fluxes, a high intensity 66 MeV proton
beam was used to produce a large yield of α-particles. This was done because
the proton inelastic scattering…
Advisors/Committee Members: Papka, Paul, Wyngaardt, Shaun M., Dobson, Robert T., Smit, Frederick D., Stellenbosch University. Faculty of Sciences. Dept. of Physics..
Subjects/Keywords: Physics; Neutron physics; Neutron transport; High flux neutron detection systems
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APA (6th Edition):
Singo, T. D. (2012). Development of a high flux neutron radiation detection system for in-core temperature monitoring. (Doctoral Dissertation). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/19999
Chicago Manual of Style (16th Edition):
Singo, Thifhelimbilu Daphney. “Development of a high flux neutron radiation detection system for in-core temperature monitoring.” 2012. Doctoral Dissertation, Stellenbosch University. Accessed January 23, 2019.
http://hdl.handle.net/10019.1/19999.
MLA Handbook (7th Edition):
Singo, Thifhelimbilu Daphney. “Development of a high flux neutron radiation detection system for in-core temperature monitoring.” 2012. Web. 23 Jan 2019.
Vancouver:
Singo TD. Development of a high flux neutron radiation detection system for in-core temperature monitoring. [Internet] [Doctoral dissertation]. Stellenbosch University; 2012. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/10019.1/19999.
Council of Science Editors:
Singo TD. Development of a high flux neutron radiation detection system for in-core temperature monitoring. [Doctoral Dissertation]. Stellenbosch University; 2012. Available from: http://hdl.handle.net/10019.1/19999
University of Texas – Austin
16.
-4066-2303.
Development of an in-core neutron monitoring system and characterization of the University of Texas at Austin TRIGA reactor steady-state neutron flux variations for use with Neutron Activation Analysis.
Degree: Mechanical Engineering, 2018, University of Texas – Austin
URL: http://hdl.handle.net/2152/69096
► The pneumatic NAA facility within The University of Texas at Austin is widely used for the measurement of trace elemental concentrations. It has been shown…
(more)
▼ The pneumatic NAA facility within The University of Texas at Austin is widely used for the measurement of trace elemental concentrations. It has been shown for extremely short duration NAA irradiations, sample activation measurements can vary by up to 12% from normalized values. The typical university research reactor’s external
neutron monitoring instruments are unable to detect small, localized variations in
neutron population likely resulting in the observed error. The primary method to reduce this uncertainty is to irradiate traceable flux monitor samples in addition to the experimental samples to be analyzed. This method doubles the required sample prep, measurement, and analysis effort. An in-core
neutron monitoring system was designed and installed adjacent to the pneumatic NAA sample system terminus to track these localized fluctuations. This design consists of a miniature in-core fission chamber fitted through the upper grid plate of the reactor core. The system is controlled by a NI LabVIEW data logging application. This system provides the capability of monitoring sample irradiance in real-time. In preliminary testing, the system was able to track short irradiation NAA sample variance to within 3% of normalized values. Thus, a significant reduction in the uncertainty of NAA measurements for trace elemental concentrations is achievable.
Advisors/Committee Members: Haas, Derek Anderson, 1981- (advisor).
Subjects/Keywords: Neutron flux monitoring; Neutron Activation Analysis; Neutron flux variance
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Manager
APA (6th Edition):
-4066-2303. (2018). Development of an in-core neutron monitoring system and characterization of the University of Texas at Austin TRIGA reactor steady-state neutron flux variations for use with Neutron Activation Analysis. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/69096
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
-4066-2303. “Development of an in-core neutron monitoring system and characterization of the University of Texas at Austin TRIGA reactor steady-state neutron flux variations for use with Neutron Activation Analysis.” 2018. Thesis, University of Texas – Austin. Accessed January 23, 2019.
http://hdl.handle.net/2152/69096.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
-4066-2303. “Development of an in-core neutron monitoring system and characterization of the University of Texas at Austin TRIGA reactor steady-state neutron flux variations for use with Neutron Activation Analysis.” 2018. Web. 23 Jan 2019.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Vancouver:
-4066-2303. Development of an in-core neutron monitoring system and characterization of the University of Texas at Austin TRIGA reactor steady-state neutron flux variations for use with Neutron Activation Analysis. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/2152/69096.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
-4066-2303. Development of an in-core neutron monitoring system and characterization of the University of Texas at Austin TRIGA reactor steady-state neutron flux variations for use with Neutron Activation Analysis. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/69096
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
Addis Ababa University
17.
Getu, Ferenji.
Measurement of Thermal neutron capture cross section in Sb-121”
.
Degree: 2013, Addis Ababa University
URL: http://etd.aau.edu.et/dspace/handle/123456789/1312
► The measurement of thermal neutron cross sections gives basic information about the internal structure of atomic nuclei and their structure. Measurement of Thermal Neutron cross-section…
(more)
▼ The measurement of thermal
neutron cross sections gives basic information about the
internal structure of atomic nuclei and their structure. Measurement of Thermal
Neutron
cross-section of Sb -121 has been performed at the Addis Ababa University Nuclear
physics Laboratory using the concept of
neutron activation Analysis. Irradiations without
Cadinium cover were performed and the
neutron transmission through the cover was
calculated. High resolution gamma ray spectrometry measurements was undertaken in
order to check the consistency of the results. The thermal
neutron cross section measured
for Sb-121 using slow neutrons is ( 5.45 0.23b). The results are discussed and
compared with previous Measurement. In general there is good agreement between the
observed and calculated value of thermal
neutron capture cross section.
Advisors/Committee Members: Prof.A.K.Chaubey (advisor).
Subjects/Keywords: Neutron sources;
Neutron interaction;
Thermal neutron cross section;
Slowing down of Neutron,;
Neutron Activation analysis;
HPGe
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APA (6th Edition):
Getu, F. (2013). Measurement of Thermal neutron capture cross section in Sb-121”
. (Thesis). Addis Ababa University. Retrieved from http://etd.aau.edu.et/dspace/handle/123456789/1312
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Getu, Ferenji. “Measurement of Thermal neutron capture cross section in Sb-121”
.” 2013. Thesis, Addis Ababa University. Accessed January 23, 2019.
http://etd.aau.edu.et/dspace/handle/123456789/1312.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Getu, Ferenji. “Measurement of Thermal neutron capture cross section in Sb-121”
.” 2013. Web. 23 Jan 2019.
Vancouver:
Getu F. Measurement of Thermal neutron capture cross section in Sb-121”
. [Internet] [Thesis]. Addis Ababa University; 2013. [cited 2019 Jan 23].
Available from: http://etd.aau.edu.et/dspace/handle/123456789/1312.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Getu F. Measurement of Thermal neutron capture cross section in Sb-121”
. [Thesis]. Addis Ababa University; 2013. Available from: http://etd.aau.edu.et/dspace/handle/123456789/1312
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
The Ohio State University
18.
Turkoglu, Danyal J.
Design, Construction and Characterization of an External
Neutron Beam Facility at The Ohio State University Nuclear Reactor
Laboratory.
Degree: MS, Nuclear Engineering, 2011, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1325228897
► The objective of this research was to bring a thermal neutron beam facility to the Ohio State University Nuclear Reactor Laboratory for the purposes of…
(more)
▼ The objective of this research was to bring a thermal
neutron beam facility to the Ohio State University Nuclear Reactor
Laboratory for the purposes of
neutron-based research. The
neutron
beam is extracted from the reactor core through a
neutron
collimator emplaced in Beam Port2, the radial beam port facing
the core at a 30° angle. The collimator is an aluminum tube
containing components designed to filter and shape the
neutron
beam. The filters are poly-crystalline bismuth (10.16 cm thickness,
12.7 cm diameter) for significantly reducing gamma ray content and
single-crystal sapphire (12.7 cm thickness, 10.16 cm diameter) for
preferentially passing thermal neutrons while scattering more
energetic neutrons out of the beam. The thermal
neutron beam is
defined by multiple 3.0 cm diameter apertures in borated aluminum.
Apertures in polyethylene-based disks and in Pb disks provide
shielding for fast neutrons and gamma rays, respectively, in the
neutron collimator. Characterization of the beam was performed
using foil activation analysis to find the
neutron flux and a
low-cost digital
neutron imaging apparatus to “see” the beam
profile. The
neutron collimator delivers the filtered thermal
neutron beam with a 3.5 cm diameter umbra and a thermal
neutron
equivalent flux of (8.55 ± 0.19) × 10
6
cm
-2s
-1 at 450 kW
reactor power (90% of rated limit) to the sample location. The beam
is highly thermalized with a cadmium ratio of 266 ± 13. The
facility was designed for
neutron depth profiling, a nondestructive
analytical technique for finding the concentration versus depth in
the near surface (tens of microns) for isotopes that undergo
charged particle emitting reactions, such as
10B(n,
4He)
7Li,
6Li
(n,
3H)
4He, and
3He
(n,
1H)
3H, to name a
few.
Advisors/Committee Members: Cao, Lei (Advisor).
Subjects/Keywords: Nuclear Engineering; neutron beam; neutron; neutron radiography; neutron depth profiling; neutron beam facility; research reactor; MCNP
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Manager
APA (6th Edition):
Turkoglu, D. J. (2011). Design, Construction and Characterization of an External
Neutron Beam Facility at The Ohio State University Nuclear Reactor
Laboratory. (Masters Thesis). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1325228897
Chicago Manual of Style (16th Edition):
Turkoglu, Danyal J. “Design, Construction and Characterization of an External
Neutron Beam Facility at The Ohio State University Nuclear Reactor
Laboratory.” 2011. Masters Thesis, The Ohio State University. Accessed January 23, 2019.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1325228897.
MLA Handbook (7th Edition):
Turkoglu, Danyal J. “Design, Construction and Characterization of an External
Neutron Beam Facility at The Ohio State University Nuclear Reactor
Laboratory.” 2011. Web. 23 Jan 2019.
Vancouver:
Turkoglu DJ. Design, Construction and Characterization of an External
Neutron Beam Facility at The Ohio State University Nuclear Reactor
Laboratory. [Internet] [Masters thesis]. The Ohio State University; 2011. [cited 2019 Jan 23].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1325228897.
Council of Science Editors:
Turkoglu DJ. Design, Construction and Characterization of an External
Neutron Beam Facility at The Ohio State University Nuclear Reactor
Laboratory. [Masters Thesis]. The Ohio State University; 2011. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1325228897
University of Tennessee – Knoxville
19.
Yue, Andrew T.
Progress Toward a Redetermination of the Neutron Lifetime Through the Absolute Determination of Neutron Flux.
Degree: 2011, University of Tennessee – Knoxville
URL: https://trace.tennessee.edu/utk_graddiss/1243
► The reported lifetime in an in-beam neutron lifetime experiment performed at NIST was tn = (886.3 ± 3.4) s. The largest source of uncertainty was…
(more)
▼ The reported lifetime in an in-beam neutron lifetime experiment performed at NIST was tn = (886.3 ± 3.4) s. The largest source of uncertainty was the efficiency of the neutron flux monitor (0.3% relative uncertainty). The flux monitor operates by counting charged particles produced when neutrons impinge on a 6Li foil. Its efficiency was calculated from the 6Li thermal neutron cross section, the solid angle subtended by the charged particle detectors, and the amount of neutron-absorbing material present on the foil. An absolute black neutron detector for cold neutron beams has been developed to measure the efficiency without the need to know these quantities. The flux monitor efficiency is measured to a precision of 0.052% using this direct calibration technique. This calibration removes the largest barrier to a 1 s neutron lifetime measurement with the beam technique. It is hoped that this data can also be used to re-evaluate the current NIST neutron lifetime value, reduce its uncertainty, and remove the dependence on evaluated nuclear data files. There is also the possibility for a direct measurement of the 6Li thermal neutron cross section.
Subjects/Keywords: fundamental neutron physics; neutron lifetime; neutron flux; lithium cross section; beam lifetime experiment
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MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Yue, A. T. (2011). Progress Toward a Redetermination of the Neutron Lifetime Through the Absolute Determination of Neutron Flux. (Doctoral Dissertation). University of Tennessee – Knoxville. Retrieved from https://trace.tennessee.edu/utk_graddiss/1243
Chicago Manual of Style (16th Edition):
Yue, Andrew T. “Progress Toward a Redetermination of the Neutron Lifetime Through the Absolute Determination of Neutron Flux.” 2011. Doctoral Dissertation, University of Tennessee – Knoxville. Accessed January 23, 2019.
https://trace.tennessee.edu/utk_graddiss/1243.
MLA Handbook (7th Edition):
Yue, Andrew T. “Progress Toward a Redetermination of the Neutron Lifetime Through the Absolute Determination of Neutron Flux.” 2011. Web. 23 Jan 2019.
Vancouver:
Yue AT. Progress Toward a Redetermination of the Neutron Lifetime Through the Absolute Determination of Neutron Flux. [Internet] [Doctoral dissertation]. University of Tennessee – Knoxville; 2011. [cited 2019 Jan 23].
Available from: https://trace.tennessee.edu/utk_graddiss/1243.
Council of Science Editors:
Yue AT. Progress Toward a Redetermination of the Neutron Lifetime Through the Absolute Determination of Neutron Flux. [Doctoral Dissertation]. University of Tennessee – Knoxville; 2011. Available from: https://trace.tennessee.edu/utk_graddiss/1243
University of Tennessee – Knoxville
20.
Harrison, Thomas Jay.
Methodology For Generating Simplified Cross Section Data Sets For Neutron Transport Calculations.
Degree: 2015, University of Tennessee – Knoxville
URL: https://trace.tennessee.edu/utk_graddiss/3583
► Neutron shielding problems involve radiation transport calculations over a wide range of energies. Fission neutrons have initial energy on the order of MeV, fusion neutrons…
(more)
▼ Neutron shielding problems involve radiation transport calculations over a wide range of energies. Fission neutrons have initial energy on the order of MeV, fusion neutrons have initial energy on the order of 10s of MeV, and space-origin neutrons have initial energy on the order of 100s of MeV or higher. Shielding calculations must track the neutrons from their initial energies until they are no longer of interest; for deep-penetration neutrons, this final energy can be on the order of eV before the neutron is no longer tracked. Thus, for deep-penetration space radiation shielding problems, the calculation may require tracking the neutron energy through eight orders of magnitude.
The shielding calculations also require the evaluation of the neutron cross section as a function of the neutron energy. However, the cross section value itself may range from 10-3 barn (1 mb) to nearly 109 barn (1 Gb), a range of twelve orders of magnitude. Further complicating the cross section analysis is the existence of resonance peaks; these peaks (or valleys) may show a change spanning multiple orders of magnitude in cross section value over less than a 1% change in neutron energy.
The issue of cross section data sets with multiple resonance peaks can be resolved through the use of flux-weighted group cross sections. The most basic group structure is a single cross section; modern analytical codes can use more than 200 groups, or the full cross section data set itself. However, this introduces a tradeoff of efficiency (fewer groups) versus accuracy (more groups), and it also requires an a priori knowledge of the flux spectrum.
This research proposes and tests a method to generate group-wise cross section data sets that do not require the a priori flux spectrum, which is equivalent to assuming a flat flux spectrum distribution. This method conserves the energy-integrated cross sections, which are an inherent characteristic of an isotope, instead of group-wise reaction rates, which are a function of the overall system. The net result is a reduction in calculation time without a significant loss in neutron survival and penetration results and the transmitted and reflected spectra.
Subjects/Keywords: Neutron Cross Section; Neutron Shielding; Monte Carlo Methods; Neutron Flux Spectrum; Nuclear; Nuclear Engineering
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APA ·
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MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Harrison, T. J. (2015). Methodology For Generating Simplified Cross Section Data Sets For Neutron Transport Calculations. (Doctoral Dissertation). University of Tennessee – Knoxville. Retrieved from https://trace.tennessee.edu/utk_graddiss/3583
Chicago Manual of Style (16th Edition):
Harrison, Thomas Jay. “Methodology For Generating Simplified Cross Section Data Sets For Neutron Transport Calculations.” 2015. Doctoral Dissertation, University of Tennessee – Knoxville. Accessed January 23, 2019.
https://trace.tennessee.edu/utk_graddiss/3583.
MLA Handbook (7th Edition):
Harrison, Thomas Jay. “Methodology For Generating Simplified Cross Section Data Sets For Neutron Transport Calculations.” 2015. Web. 23 Jan 2019.
Vancouver:
Harrison TJ. Methodology For Generating Simplified Cross Section Data Sets For Neutron Transport Calculations. [Internet] [Doctoral dissertation]. University of Tennessee – Knoxville; 2015. [cited 2019 Jan 23].
Available from: https://trace.tennessee.edu/utk_graddiss/3583.
Council of Science Editors:
Harrison TJ. Methodology For Generating Simplified Cross Section Data Sets For Neutron Transport Calculations. [Doctoral Dissertation]. University of Tennessee – Knoxville; 2015. Available from: https://trace.tennessee.edu/utk_graddiss/3583
University of Illinois – Urbana-Champaign
21.
Liu, Yi.
Simultaneous fast and slow neutron detection with superheated droplet detector and real-time readout system.
Degree: PhD, Nuclear, Plasma, Radiolgc Engr, 2017, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/98096
► Alternative slow neutron detection technologies are desired in response to needs by homeland security and radiation safety. Superheated droplet detectors (SDD) have the potential to…
(more)
▼ Alternative slow
neutron detection technologies are desired in response to needs by homeland security and radiation safety. Superheated droplet detectors (SDD) have the potential to be used in both situations because they have many distinct characteristics, such as photon insensitivity, passive operation, tissue-equivalent composition, isotropic response, flexible size, and low cost. A
neutron detection system based on SDDs is developed in this research for simultaneous detection of fast neutrons and slow neutrons. The detection system is composed of two SDDs and an imaging-readout system. One of the SDDs is doped with 3.4%
6LiCl, and the other one is a regular SDD. In the imaging-readout system of the detection system, machine learning algorithms are developed for accurate bubble counting. The algorithms show a much better accuracy and precision than traditionally used algorithms.
Advisors/Committee Members: Sullivan, Clair Julia (advisor), Sullivan, Clair Julia (Committee Chair), d'Errico, Francesco (committee member), Stubbins, James F (committee member), Meng, Lingjian (committee member).
Subjects/Keywords: Neutron detection; Superheated droplet detector; Radiation portal monitors; Neutron dosimeter; Neutron spectrometer
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Liu, Y. (2017). Simultaneous fast and slow neutron detection with superheated droplet detector and real-time readout system. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/98096
Chicago Manual of Style (16th Edition):
Liu, Yi. “Simultaneous fast and slow neutron detection with superheated droplet detector and real-time readout system.” 2017. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed January 23, 2019.
http://hdl.handle.net/2142/98096.
MLA Handbook (7th Edition):
Liu, Yi. “Simultaneous fast and slow neutron detection with superheated droplet detector and real-time readout system.” 2017. Web. 23 Jan 2019.
Vancouver:
Liu Y. Simultaneous fast and slow neutron detection with superheated droplet detector and real-time readout system. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2017. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/2142/98096.
Council of Science Editors:
Liu Y. Simultaneous fast and slow neutron detection with superheated droplet detector and real-time readout system. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2017. Available from: http://hdl.handle.net/2142/98096
University of Edinburgh
22.
Fang, Junwei.
Instrumentation development for neutron scattering at high pressure.
Degree: PhD, 2012, University of Edinburgh
URL: http://hdl.handle.net/1842/7692
► Neutron scattering at extremes of pressure is a powerful tool for studying the response of structural and magnetic properties of materials on microscopic level to…
(more)
▼ Neutron scattering at extremes of pressure is a powerful tool for studying the response of structural and magnetic properties of materials on microscopic level to applied stresses. However, experimental neutron studies require a relatively large sample volume, which makes it necessary to use rather large presses. One of the most commonly used high-pressure devices in neutron diffraction experiments is the Paris-Edinburgh (P-E) press. This compact hydraulic press has been successfully used at various neutron facilities across the world for over 20 years. However, there are some limitations imposed by the design of the press and this project addressed two of them. The first objective of this research was to solve the problem of the spatial restriction on the scattered beam imposed by the tie-rods of the P-E press which results in the limited access to the reciprocal space of a single-crystalline sample. In order to overcome this challenge a rotating device has been designed and built to work with the existing P-E press mainframe. The purpose of the device is to rotate the anvils at a high load in a controlled fashion so that neutron diffraction data can be collected from the sample at particular angles. A number of technical challenges had to be overcome in the design process. One of the problems was caused by the significant friction in the commercially available thrust roller bearings at loads above 25 tonnes. To resolve this issue a set of custom-designed hydraulic bearings has been developed. In these bearings a thin layer of oil separates the two parts that can rotate with respect to each other.
Subjects/Keywords: high pressure; RV4; neutron scattering
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Manager
APA (6th Edition):
Fang, J. (2012). Instrumentation development for neutron scattering at high pressure. (Doctoral Dissertation). University of Edinburgh. Retrieved from http://hdl.handle.net/1842/7692
Chicago Manual of Style (16th Edition):
Fang, Junwei. “Instrumentation development for neutron scattering at high pressure.” 2012. Doctoral Dissertation, University of Edinburgh. Accessed January 23, 2019.
http://hdl.handle.net/1842/7692.
MLA Handbook (7th Edition):
Fang, Junwei. “Instrumentation development for neutron scattering at high pressure.” 2012. Web. 23 Jan 2019.
Vancouver:
Fang J. Instrumentation development for neutron scattering at high pressure. [Internet] [Doctoral dissertation]. University of Edinburgh; 2012. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1842/7692.
Council of Science Editors:
Fang J. Instrumentation development for neutron scattering at high pressure. [Doctoral Dissertation]. University of Edinburgh; 2012. Available from: http://hdl.handle.net/1842/7692
23.
Trulsson, Linus.
Probabilistic Neutron Tracker.
Degree: 2009, Chalmers University of Technology
URL: http://studentarbeten.chalmers.se/publication/180755-probabilistic-neutron-tracker
► In order to gain further understanding of subatomic physics, research is conducted close to the drip line, where the ratio of the constituents of the…
(more)
▼ In order to gain further understanding of subatomic physics, research is conducted close to the drip line, where the ratio of the constituents of the nuclear core is at the extreme. In experiments, liberated neutrons, which have no charge, are difficult to detect because only the effects of collisions with charged particles can be observed. Collisions at the subatomic level may involve different physical processes and branch into several other collisions.
A neutron detector called LAND, situated in the GSI facility outside Darmstadt, Germany, is capable of observing these collisions. The algorithm currently used to recognize neutrons from the collisions is heavily based on macroscopic observations of how the neutron detector behaves. It is greedy and therefore tends to underestimate the number of neutrons for complicated events.
This project continues investigations from an earlier project, aimed at de- signing a probabilistic method to reconstruct neutrons from neutron detector data. Visualisations of the new algorithm show promising results of resolving neutron paths and branching and statistical results show good capabilities in estimating the number of neutrons. Some very important problems could not be solved, but the effects of the problems can be understood and explained from the obtained results.
An algorithm based on probability functions of subatomic interactions seems to be a viable concept and will most probably see continued exploration and improvement by future masters students.
Subjects/Keywords: Neutron; reconstruction; GSI; LAND
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Trulsson, L. (2009). Probabilistic Neutron Tracker. (Thesis). Chalmers University of Technology. Retrieved from http://studentarbeten.chalmers.se/publication/180755-probabilistic-neutron-tracker
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Trulsson, Linus. “Probabilistic Neutron Tracker.” 2009. Thesis, Chalmers University of Technology. Accessed January 23, 2019.
http://studentarbeten.chalmers.se/publication/180755-probabilistic-neutron-tracker.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Trulsson, Linus. “Probabilistic Neutron Tracker.” 2009. Web. 23 Jan 2019.
Vancouver:
Trulsson L. Probabilistic Neutron Tracker. [Internet] [Thesis]. Chalmers University of Technology; 2009. [cited 2019 Jan 23].
Available from: http://studentarbeten.chalmers.se/publication/180755-probabilistic-neutron-tracker.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Trulsson L. Probabilistic Neutron Tracker. [Thesis]. Chalmers University of Technology; 2009. Available from: http://studentarbeten.chalmers.se/publication/180755-probabilistic-neutron-tracker
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
24.
Kubešová Marie.
k0 standardization in neutron activation analysis at LVR-15 reactor in Řež
.
Degree: 2012, Czech University of Technology
URL: http://hdl.handle.net/10467/9739
k0 standardization in neutron activation analysis at LVR-15 reactor; k0 standardization in neutron activation analysis at LVR-15 reactor
Advisors/Committee Members: Kučera Jan (advisor).Subjects/Keywords: k0 standardization; neutron activation analysis
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Manager
APA (6th Edition):
Marie, K. (2012). k0 standardization in neutron activation analysis at LVR-15 reactor in Řež
. (Thesis). Czech University of Technology. Retrieved from http://hdl.handle.net/10467/9739
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Marie, Kubešová. “k0 standardization in neutron activation analysis at LVR-15 reactor in Řež
.” 2012. Thesis, Czech University of Technology. Accessed January 23, 2019.
http://hdl.handle.net/10467/9739.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Marie, Kubešová. “k0 standardization in neutron activation analysis at LVR-15 reactor in Řež
.” 2012. Web. 23 Jan 2019.
Vancouver:
Marie K. k0 standardization in neutron activation analysis at LVR-15 reactor in Řež
. [Internet] [Thesis]. Czech University of Technology; 2012. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/10467/9739.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Marie K. k0 standardization in neutron activation analysis at LVR-15 reactor in Řež
. [Thesis]. Czech University of Technology; 2012. Available from: http://hdl.handle.net/10467/9739
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Ontario Institute of Technology
25.
Kicka, Leslie.
Characterization of neutron fields around an intense neutron generator.
Degree: 2016, University of Ontario Institute of Technology
URL: http://hdl.handle.net/10155/758
► Neutron fields in the vicinity of the University of Ontario Institute of Technology neutron facility have been investigated in a series of simulations and experiments.…
(more)
▼ Neutron fields in the vicinity of the University of Ontario Institute of Technology
neutron facility have been investigated in a series of simulations and experiments. The
neutron fluence at several locations around the
neutron generator facility has been simulated using MCNPX 2.7E Monte Carlo particle transport program. The P-385
neutron generator is configured to function with a deuterium-deuterium fusion reaction using accelerated charged deuterons colliding with a metal deuteride target. This fusion reaction is characterized by an anisotropic angular and energy distribution in the centre-of-mass and laboratory frames of reference. Three
neutron sources were modelled in the simulation with distributions corresponding to different incident deuteron energies of 130 keV, 110 keV, and 90 keV. An idealized isotropic source was likewise simulated for purposes of comparison and determination of the applicability of such an approximation.
Along with the performed simulations and to validate the calculation, a series of experiments have been carried out to determine the dose rate measurement at locations adjacent to the generator. The collected data were used to calculate the
neutron intensity of the P-385
neutron generator. The measurements were taken using bubble detectors with different sensitivities. Also, the total dose rates corresponding to applied acceleration potentials were estimated at various locations, utilizing a thin target approximation.
Advisors/Committee Members: Machrafi, Rachid.
Subjects/Keywords: Neutron; Facility; Dose; Fluence; Simulation
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APA (6th Edition):
Kicka, L. (2016). Characterization of neutron fields around an intense neutron generator. (Thesis). University of Ontario Institute of Technology. Retrieved from http://hdl.handle.net/10155/758
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kicka, Leslie. “Characterization of neutron fields around an intense neutron generator.” 2016. Thesis, University of Ontario Institute of Technology. Accessed January 23, 2019.
http://hdl.handle.net/10155/758.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kicka, Leslie. “Characterization of neutron fields around an intense neutron generator.” 2016. Web. 23 Jan 2019.
Vancouver:
Kicka L. Characterization of neutron fields around an intense neutron generator. [Internet] [Thesis]. University of Ontario Institute of Technology; 2016. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/10155/758.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kicka L. Characterization of neutron fields around an intense neutron generator. [Thesis]. University of Ontario Institute of Technology; 2016. Available from: http://hdl.handle.net/10155/758
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
26.
Bianchini, Matteo.
In situ diffraction studies of electrode materials for Li-ion and Na-ion batteries : Etudes de diffraction in situ pour matériaux d'électrode en batteries Li-ion et Na-ion.
Degree: Docteur es, Chimie. Chimie des solides et sciences des matériaux, 2015, Amiens
URL: http://www.theses.fr/2015AMIE0022
► Ce travail vise à étudier les matériaux d'électrodes pour batteries Li-ion et Na-ion lors qu’ils fonctionnent à l'intérieur des batteries. Afin de comprendre l'évolution structurelle…
(more)
▼ Ce travail vise à étudier les matériaux d'électrodes pour batteries Li-ion et Na-ion lors qu’ils fonctionnent à l'intérieur des batteries. Afin de comprendre l'évolution structurelle des matériaux alors que les ions Li+ ou Na+ sont insérés/extraits de leur cadre, on utilise principalement la diffraction, exploitant neutrons, rayons X et le rayonnement synchrotron (SR). Nous avons adopté une approche combinée des mesures ex situ, in situ et operando. Au début, nous avons conçu une cellule électrochimique pour mesures in situ de diffraction de neutrons sur poudre (NPD), avec un alliage en (Ti,Zr) "transparent aux neutrons"; cette cellule s'est ajoutée à l’ensemble de nos outils pour effectuer des études de type operando. Nous avons démontré leur faisabilité en utilisant LiFePO4, montrant de bonnes performances électrochimiques et des données NPD de haute qualité pour affinements structurales Rietveld. Ensuite, nous avons réalisé des études des spinelles Li1+xMn2-xO4 (x=0,0.05,0.10) et LiNi0.4Mn1.6O4: pendant le cyclage, nous avons rapporté des évolutions structurelles, des diagrammes de phases et paramètres subtils tels que le comportement du Li, ou les facteurs de température. L’utilisation complémentaire du SR a clarifié la nature de la phase ordonnée Li0.5Mn2O4. Nos études combinées ont concernées d’autres matériaux d'électrodes prometteurs: LiVPO4O et Na3V2(PO4)2F3. Les 2 révèle des comportements complexes pendant la (de)intercalation du Li+/Na+. Les données de haute qualité ont permis des analyses quantitatives, dévoilant la structure d'un grand nombre des phases ordonnées et menant à la compréhension du comportement des cations dans ces matériaux
This work aims at studying electrode materials for Li-ion and Na-ion batteries as they function inside batteries. Diffraction is the mainly used technique, exploiting neutrons, X-Rays and synchrotron radiation (SR), to obtain insights on the structural evolution of such materials as Li+ or Na+ are inserted/extracted from their framework. We adopted a combined approach of ex situ, in situ and operando measurements to extract a maximum of information from our studies. At first, we designed an electrochemical cell for in situ neutron powder diffraction (NPD) measurements, featuring a “neutron-transparent” (Ti,Zr) alloy; this cell, joined to others previously developed in our group, gave us a complete set of tools to perform our studies. We demonstrated the feasibility of operando NPD using LiFePO4, showing good electrochemical performances and high-quality NPD patterns for Rietveld structural refinements. Then we carried out detailed studies of spinels Li1+xMn2-xO4 (x = 0, 0.05, 0.10) and LiNi0.4Mn1.6O4: we reported phase diagrams, structural evolutions and subtle parameters as lithium's behavior inside the spinel framework, or thermal displacement parameters, directly upon cycling. Complementary use of SR shed light on other features, as the nature of the ordered phase Li0.5Mn2O4. Our combined studies concerned other promising electrode materials: LiVPO4O and…
Advisors/Committee Members: Masquelier, Christian (thesis director).
Subjects/Keywords: Neutron; Crystal structures; 540
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APA ·
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MLA ·
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APA (6th Edition):
Bianchini, M. (2015). In situ diffraction studies of electrode materials for Li-ion and Na-ion batteries : Etudes de diffraction in situ pour matériaux d'électrode en batteries Li-ion et Na-ion. (Doctoral Dissertation). Amiens. Retrieved from http://www.theses.fr/2015AMIE0022
Chicago Manual of Style (16th Edition):
Bianchini, Matteo. “In situ diffraction studies of electrode materials for Li-ion and Na-ion batteries : Etudes de diffraction in situ pour matériaux d'électrode en batteries Li-ion et Na-ion.” 2015. Doctoral Dissertation, Amiens. Accessed January 23, 2019.
http://www.theses.fr/2015AMIE0022.
MLA Handbook (7th Edition):
Bianchini, Matteo. “In situ diffraction studies of electrode materials for Li-ion and Na-ion batteries : Etudes de diffraction in situ pour matériaux d'électrode en batteries Li-ion et Na-ion.” 2015. Web. 23 Jan 2019.
Vancouver:
Bianchini M. In situ diffraction studies of electrode materials for Li-ion and Na-ion batteries : Etudes de diffraction in situ pour matériaux d'électrode en batteries Li-ion et Na-ion. [Internet] [Doctoral dissertation]. Amiens; 2015. [cited 2019 Jan 23].
Available from: http://www.theses.fr/2015AMIE0022.
Council of Science Editors:
Bianchini M. In situ diffraction studies of electrode materials for Li-ion and Na-ion batteries : Etudes de diffraction in situ pour matériaux d'électrode en batteries Li-ion et Na-ion. [Doctoral Dissertation]. Amiens; 2015. Available from: http://www.theses.fr/2015AMIE0022
University of Alberta
27.
Elshamouty, Khaled G.
Characteristics of Neutron Stars from X-Rays
Observations.
Degree: PhD, Department of Physics, 2016, University of Alberta
URL: https://era.library.ualberta.ca/files/cdf65v805w
► Neutron stars (NSs) are some of the densest objects in the universe. In this thesis, I focus on studying X-ray thermal emission from neutron stars,…
(more)
▼ Neutron stars (NSs) are some of the densest objects in
the universe. In this thesis, I focus on studying X-ray thermal
emission from neutron stars, using X-ray observations of different
varieties of NSs. X-ray observations can put constraints on the
mass and radius of NSs, and thus on density and pressure of neutron
star interiors, with consequences for the dense matter equation of
state. X-ray observations can also constrain the temperature of
NSs, with implications for the superfluidity of the core, and the
composition and superfluid state of the crust. In the first part of
this thesis, I constrain the cooling of the NS surface temperature
in the young NS in the Cas A supernova remnant, using X-ray flux
measurements over 10 years using several detectors on the Chandra
X-ray Observatory. Although measurements using Chandra’s ACIS-S
detector show fast cooling, measurements using Chandra’s HRC-S
detector find a significantly slower rate of cooling for this NS.
Fitting the thermal X-ray spectra of neutron stars in quiescent
X-ray binaries can be used to measure the NS radii. However, the
effect of undetected hot spots on the spectrum, and thus on the
inferred NS mass and radius, has not yet been explored for
appropriate atmospheres and spectra. A hot spot would harden the
observed spectrum, so that spectral modeling tends to infer radii
that are too small. However, a hot spot may also produce detectable
pulsations. I simulated the effects of a hot spot on the pulsed
fraction and spectrum of the quiescent NSs X5 and X7 in the
globular cluster 47 Tucanae using appropriate spectra and beaming
for hydrogen atmosphere models, incorporating special and general
relativistic effects, and sampling a range of system angles. A
search for pulsations in archival Chandra HRC-S observations of two
quiescent NS low-mass X-ray binaries in 47 Tuc, X5 and X7, places a
90% confidence upper limits on their pulsed fractions below 16%.
These pulsation limits constrain the temperature differential of
any hot spots. I then constrain the effects of the possible hot
spots on the X-ray spectrum and the inferred radius from spectral
fitting. Hot spots below our pulsation limit could bias the
spectroscopically inferred radius downward by up to 28%. For Cen
X-4 (which has deeper published pulsation searches), an undetected
hot spot could bias its inferred radius downward by up to 10%.
Improving constraints on pulsations from quiescent LMXBs is
essential for progress in constraining their radii. Finally, I
investigate the spectrum of a high-magnetic-field NS in a high-mass
X-ray binary (HMXB). The propeller effect in accreting rotating
neutron stars should cut off accretion in fast-spinning neutron
star HMXBs at low mass transfer rates. However, the accretion
continues in some HMXBs, as evidenced by continuing pulsations, at
low luminosities. Indications of spectral softening in systems in
the propeller regime suggest that some HMXBs are undergoing
fundamental changes in their accretion regime. I use a 39 ks
XMM-Newton observation of the transient…
Subjects/Keywords: Neutron Stars; X-ray
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Elshamouty, K. G. (2016). Characteristics of Neutron Stars from X-Rays
Observations. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/cdf65v805w
Chicago Manual of Style (16th Edition):
Elshamouty, Khaled G. “Characteristics of Neutron Stars from X-Rays
Observations.” 2016. Doctoral Dissertation, University of Alberta. Accessed January 23, 2019.
https://era.library.ualberta.ca/files/cdf65v805w.
MLA Handbook (7th Edition):
Elshamouty, Khaled G. “Characteristics of Neutron Stars from X-Rays
Observations.” 2016. Web. 23 Jan 2019.
Vancouver:
Elshamouty KG. Characteristics of Neutron Stars from X-Rays
Observations. [Internet] [Doctoral dissertation]. University of Alberta; 2016. [cited 2019 Jan 23].
Available from: https://era.library.ualberta.ca/files/cdf65v805w.
Council of Science Editors:
Elshamouty KG. Characteristics of Neutron Stars from X-Rays
Observations. [Doctoral Dissertation]. University of Alberta; 2016. Available from: https://era.library.ualberta.ca/files/cdf65v805w
Texas A&M University
28.
Thornton, Angela Lynn.
Development of a portable neutron coincidence counter for field measurements of nuclear materials using the advanced multiplicity capabilities of MCNPX 2.5.F and the neutron coincidence point model.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2095
► Neutron coincidence counting is an important passive Nondestructive Assay (NDA) technique widely used for qualitative and quantitative analysis of nuclear material in bulk samples. During…
(more)
▼ Neutron coincidence counting is an important passive Nondestructive Assay (NDA) technique widely used for qualitative and quantitative analysis of nuclear material in bulk samples. During the fission process, multiple neutrons are simultaneously emitted from the splitting nucleus. These
neutron groups are often referred to as coincident neutrons. Because different isotopes possess different coincident
neutron characteristics, the coincident
neutron signature can be used to identify and quantify a given material. In an effort to identify unknown nuclear samples in field inspections, the Portable
Neutron Coincidence Counter (PNCC) has been developed. This detector makes use of the coincident neutrons being emitted from a bulk sample. An in-depth analysis has been performed to establish whether the nuclear material in an unknown sample could be quantified with the accuracy and precision needed for safeguards measurements. The analysis was performed by comparing experimental measurements of PuO2 samples to the calculated output produced using MCNPX and the
Neutron Coincidence Point Model. Based on the analysis, it is evident that this new portable system can play a useful role in identifying nuclear material for verification purposes.
Advisors/Committee Members: Charlton, William S. (advisor), Nelson, Paul (committee member), Vedlitz, Arnold (committee member).
Subjects/Keywords: Neutron; Coincidence; Portable; Nuclear; Plutonium
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Thornton, A. L. (2009). Development of a portable neutron coincidence counter for field measurements of nuclear materials using the advanced multiplicity capabilities of MCNPX 2.5.F and the neutron coincidence point model. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2095
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Thornton, Angela Lynn. “Development of a portable neutron coincidence counter for field measurements of nuclear materials using the advanced multiplicity capabilities of MCNPX 2.5.F and the neutron coincidence point model.” 2009. Thesis, Texas A&M University. Accessed January 23, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2095.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Thornton, Angela Lynn. “Development of a portable neutron coincidence counter for field measurements of nuclear materials using the advanced multiplicity capabilities of MCNPX 2.5.F and the neutron coincidence point model.” 2009. Web. 23 Jan 2019.
Vancouver:
Thornton AL. Development of a portable neutron coincidence counter for field measurements of nuclear materials using the advanced multiplicity capabilities of MCNPX 2.5.F and the neutron coincidence point model. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2095.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Thornton AL. Development of a portable neutron coincidence counter for field measurements of nuclear materials using the advanced multiplicity capabilities of MCNPX 2.5.F and the neutron coincidence point model. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2095
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
29.
Inyang, Otu Effiong.
Development of a prompt-gamma, neutron-activation analysis facility at the Texas A&M University Nuclear Science Center.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2980
► A prompt-gamma, neutron-activation analysis facility earlier developed at the Nuclear Science Center of Texas A&M University could not be used successfully to analyze geologic samples…
(more)
▼ A prompt-gamma,
neutron-activation analysis facility earlier developed at the Nuclear Science Center of Texas A&M University could not be used successfully to analyze geologic samples due to high detection background, low
neutron fluence rate and poor detection equipment . A systematic investigation into the performance capability of a prompt-gamma,
neutron activation analysis facility was undertaken in this research project. The facility was reconstructed and used to obtain prompt-gamma spectra of chlorine and cadmium and from the spectra, the net peak area counts for the most intense prompt-gamma-ray energies were obtained. A theoretical model was developed which can predict the net peak area counts expected on these prompt-gamma-ray energies using the thermal
neutron fluence rate at the sample position, the absolute efficiency of the detector, and the mass and partial gamma-ray production cross section data for the samples. The experimental and predicted results were compared to establish the performance capability of the reconstructed facility. Good agreements between experimental and predicted results were obtained for chlorine, but results from cadmium showed larger discrepancies due to self-shielding effects. Corrections for self-shielding effects were applied to results from cadmium and the experimental and predicted results were also in good agreement. The satisfactory results indicate that it is possible to implement the prompt-gamma,
neutron-activation analysis technique at Beam Port1 of the Nuclear Science Center Reactor. To be able to obtain excellent results from other samples, improvements in shielding materials to attain a lower detection background and a highly efficient detection system should be incorporated.
Advisors/Committee Members: REECE, DANIEL W. (advisor), POSTON, John W Sr. (committee member), WALKER, Micheal A. (committee member).
Subjects/Keywords: PROMPT-GAMMA; NEUTRON-ACTIVATION ANALYSIS
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APA ·
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Export
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Manager
APA (6th Edition):
Inyang, O. E. (2009). Development of a prompt-gamma, neutron-activation analysis facility at the Texas A&M University Nuclear Science Center. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2980
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Inyang, Otu Effiong. “Development of a prompt-gamma, neutron-activation analysis facility at the Texas A&M University Nuclear Science Center.” 2009. Thesis, Texas A&M University. Accessed January 23, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2980.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Inyang, Otu Effiong. “Development of a prompt-gamma, neutron-activation analysis facility at the Texas A&M University Nuclear Science Center.” 2009. Web. 23 Jan 2019.
Vancouver:
Inyang OE. Development of a prompt-gamma, neutron-activation analysis facility at the Texas A&M University Nuclear Science Center. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2980.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Inyang OE. Development of a prompt-gamma, neutron-activation analysis facility at the Texas A&M University Nuclear Science Center. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2980
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
30.
Chung, Kiwhan.
Design and optimization of 6li neutron-capture pulse mode ion chamber.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-3022
► The purpose of this research is to design and optimize the performance of a unique, inexpensive 6Li neutron-capture pulse-mode ion chamber (LiPMIC) for neutron detection…
(more)
▼ The purpose of this research is to design and optimize the performance of a unique,
inexpensive 6Li
neutron-capture pulse-mode ion chamber (LiPMIC) for
neutron
detection that overcomes the fill-gas contamination stemming from outgas of detector
components. This research also provides a demonstration of performance of LiPMICs.
Simulations performed with GARFIELD, a drift-chamber simulation package for ion
transport in an electrostatic field, have shown that argon-methane mixtures of fill-gas
allow maintenance of electron drift velocity through a surprisingly wide range of fill-gas
content.
During the design stage of LiPMIC development, the thicknesses of lithium
metallization layer, the
neutron energy conversion site of the detector, and the thickness
of
neutron moderator, the high-density polyethylene body, are optimized through
analytical and MCNPX calculations. Also, a methodology of obtaining the suitable
combination of electric field strength, electron drift velocity, and fill-gas mixtures has been tested and simulated using argon-methane gas mixtures. The LiPMIC is shown to
have comparable efficiency to 3He proportional counters at a fraction of cost. Six-month
long baseline measurements of overall detector performance shows there is a 3%
reduction in total counts for 252Cf sources, which provides a good indicator for the
longevity of the detector.
Advisors/Committee Members: Braby, Les A. (advisor), Adams, Marvin L (committee member), Ford, John (committee member), Smith, Morag K. (committee member), White, James T. (committee member).
Subjects/Keywords: radiation detector; thermal neutron
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APA ·
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MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chung, K. (2009). Design and optimization of 6li neutron-capture pulse mode ion chamber. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-3022
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chung, Kiwhan. “Design and optimization of 6li neutron-capture pulse mode ion chamber.” 2009. Thesis, Texas A&M University. Accessed January 23, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-3022.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chung, Kiwhan. “Design and optimization of 6li neutron-capture pulse mode ion chamber.” 2009. Web. 23 Jan 2019.
Vancouver:
Chung K. Design and optimization of 6li neutron-capture pulse mode ion chamber. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Jan 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3022.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chung K. Design and optimization of 6li neutron-capture pulse mode ion chamber. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3022
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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Open Access Theses and Dissertations