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1.
Alhawsawi, Abdulsalam M.
Study of Compton suppression capability in a triple-layer phoswich detector.
Degree: MS, Radiation Health Physics, 2011, Oregon State University
URL: http://hdl.handle.net/1957/22822 
► A triple layer phoswich detector was designed and assembled in the advanced radiation instrumentation lab at Oregon State University. The detector had three scintillation layers:…
(more)
▼ A triple layer
phoswich detector was designed and assembled in the advanced radiation instrumentation lab at Oregon State University. The detector had three scintillation layers: the first one was a BC-400 for beta and conversion electron detection, the second layer was a CsI(Tl) for x-ray and gamma detection, and the third layer was BGO for shielding the CsI(Tl) crystal from background radiation and identifying scattered photons from the CsI(Tl) layer. Digital pulse processing was utilized to analyze pulses at a 200 MHz sampling rate. Pulses were analyzed according to their light decay time. The detector was able to suppress Compton events in low energy spectrum through pulse shape analysis. Suppression factors were calculated at the 90 keV and 250 keV regions in the ¹³⁷Cs gamma ray spectrum. Compton suppression capability reduced the Compton continuum at 90 keV region, and at 250 keV region by a factor of 56.5%, and 68.3%, respectively.
Advisors/Committee Members: Farsoni, Abdollah T. (advisor), Hamby, David M. (committee member).
Subjects/Keywords: phoswich
…Suppression
Capability
in
a
Triple-‐Layer
Phoswich
Detector.
Abstract… …approved:
Abdollah
T.
Farsoni
A
triple
layer
phoswich
detector… …Triple-‐Layer
Phoswich
Detector
by
Abdulsalam
M.
Alhawsawi… …contribution
defiantly
enhanced
my
understanding
of
phoswich
detector… …research
in
phoswich
detectors
for
more
than
five
years.
I…
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APA (6th Edition):
Alhawsawi, A. M. (2011). Study of Compton suppression capability in a triple-layer phoswich detector. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/22822
Chicago Manual of Style (16th Edition):
Alhawsawi, Abdulsalam M. “Study of Compton suppression capability in a triple-layer phoswich detector.” 2011. Masters Thesis, Oregon State University. Accessed March 07, 2021.
http://hdl.handle.net/1957/22822.
MLA Handbook (7th Edition):
Alhawsawi, Abdulsalam M. “Study of Compton suppression capability in a triple-layer phoswich detector.” 2011. Web. 07 Mar 2021.
Vancouver:
Alhawsawi AM. Study of Compton suppression capability in a triple-layer phoswich detector. [Internet] [Masters thesis]. Oregon State University; 2011. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1957/22822.
Council of Science Editors:
Alhawsawi AM. Study of Compton suppression capability in a triple-layer phoswich detector. [Masters Thesis]. Oregon State University; 2011. Available from: http://hdl.handle.net/1957/22822
2.
Duncan, Christopher L.
Prototyping a triple-layer phoswich detection system.
Degree: MS, Radiation Health Physics, 2011, Oregon State University
URL: http://hdl.handle.net/1957/21789
► Multi-layer optically coupled scintillation based radiation detectors, known as phoswich detectors, have rapidly evolved in recent years. During the same time, digital signal processing has…
(more)
▼ Multi-layer optically coupled scintillation based radiation detectors, known as
phoswich detectors, have rapidly evolved in recent years. During the same time, digital signal processing has improved radiation discrimination accuracy and enhanced reliability, while reducing complexity and size of traditional analog signal processing methods. A new generation of high-speed radiation detectors that can measure mixed radiation fields has been developed by coupling these advancements. A prototype of one of the first commercially available
phoswich detection systems has been analyzed to determine operational characteristics. The
phoswich detector was analyzed using a variety of radioactive sources across a battery of tests compiled from the literature, Federal government regulations, and end-users specifications. It was found that the
phoswich detection system operates equally well in beta particle, gamma-ray, and combined radiation fields. Testing at 5 centimeters demonstrated the
phoswich detector's gamma-ray full-energy-peak intrinsic efficiency to range from 0.64 to 3.25 percent, full-energy-peak resolution from 6.29 (1332 keV) to 12.07 (356 keV) percent, and detectable energy range from 30 keV to 2754 keV. Similar testing for beta particles demonstrated an intrinsic efficiency of up to 58 percent. The system did exhibit saturation in radiation fields above 0.008 μCi when used with MATLAB. The
phoswich detection system demonstrated that it is quite capable of accurately measuring the type and energy of radiation present in combined beta particle and gamma-ray radiation fields.
Advisors/Committee Members: Hamby, David M. (advisor), Farsoni, Abi (committee member).
Subjects/Keywords: Phoswich
…25
Figure 2-21: High-energy beta particle interacting in two layers of a phoswich and the… …31
Figure 3-1: Layers of the studied phoswich detector… …33
Figure 3-2: Photograph of the studied phoswich in its final state… …over
the phoswich window while taking measurements… …between source and phoswich window…
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APA (6th Edition):
Duncan, C. L. (2011). Prototyping a triple-layer phoswich detection system. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/21789
Chicago Manual of Style (16th Edition):
Duncan, Christopher L. “Prototyping a triple-layer phoswich detection system.” 2011. Masters Thesis, Oregon State University. Accessed March 07, 2021.
http://hdl.handle.net/1957/21789.
MLA Handbook (7th Edition):
Duncan, Christopher L. “Prototyping a triple-layer phoswich detection system.” 2011. Web. 07 Mar 2021.
Vancouver:
Duncan CL. Prototyping a triple-layer phoswich detection system. [Internet] [Masters thesis]. Oregon State University; 2011. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1957/21789.
Council of Science Editors:
Duncan CL. Prototyping a triple-layer phoswich detection system. [Masters Thesis]. Oregon State University; 2011. Available from: http://hdl.handle.net/1957/21789
Oregon State University
3.
Jones, Sean E.
An investigation of the light capture properties of the XEPHWICH, a phoswich
radiation detection system.
Degree: MS, Radiation Health Physics, 2008, Oregon State University
URL: http://hdl.handle.net/1957/8906
► The XEPHWICH system is a phoswich type (multiple scintillator) radiation detector designed to detect several radioxenon isotopes with the goal of identifying covert nuclear explosions.…
(more)
▼ The XEPHWICH system is a
phoswich type (multiple scintillator) radiation
detector designed to detect several radioxenon isotopes with the goal of identifying covert
nuclear explosions. The XEPHWICH system is designed with the sole purpose of
replacing the Automated Radio-xenon Sampler/Analyzer (ARSA) in the United Nation's
(UN) Comprehensive Test Ban Treaty's (CTBT) International Monitoring System (IMS).
This study consists of two stages, computer simulation and laboratory experiment.
The use of DETECT2000, a Monte-Carlo optical simulator, was the method by which
optical performance and potential improvements to the XEPHWICH design were
investigated. The laboratory experiment conducted in this study validated the modeling
methods used in the study and investigated the effects of light capture efficiency on
XEPHWICH system output. The experiment consisted of exposing the NaI(Tl) layer of
the XEPHWICH to a lead collimated Cs-137 beam at varying locations, and comparing
the differential energy spectra observed.
The simulation work resulted in design considerations for improving the optical
performance of the XEPHWICH. Additionally, through simulation, the optical
performance of the XEPHWICH was characterized and can be compared to competing
scintillator designs. The experimental observations included expected and unexpected
effects that light capture properties had on the system signal. Of particular importance,
the experimental results supported the modeling method applied, and demonstrated that
an increase in expected light capture efficiency was associated with better energy
resolution for a full energy peak in a differential pulse height spectrum.
Advisors/Committee Members: Hamby, David (advisor), Anna, Harding (committee member).
Subjects/Keywords: Phoswich; Scintillation counters
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APA (6th Edition):
Jones, S. E. (2008). An investigation of the light capture properties of the XEPHWICH, a phoswich
radiation detection system. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/8906
Chicago Manual of Style (16th Edition):
Jones, Sean E. “An investigation of the light capture properties of the XEPHWICH, a phoswich
radiation detection system.” 2008. Masters Thesis, Oregon State University. Accessed March 07, 2021.
http://hdl.handle.net/1957/8906.
MLA Handbook (7th Edition):
Jones, Sean E. “An investigation of the light capture properties of the XEPHWICH, a phoswich
radiation detection system.” 2008. Web. 07 Mar 2021.
Vancouver:
Jones SE. An investigation of the light capture properties of the XEPHWICH, a phoswich
radiation detection system. [Internet] [Masters thesis]. Oregon State University; 2008. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1957/8906.
Council of Science Editors:
Jones SE. An investigation of the light capture properties of the XEPHWICH, a phoswich
radiation detection system. [Masters Thesis]. Oregon State University; 2008. Available from: http://hdl.handle.net/1957/8906
Oregon State University
4.
Yousefi, Siavash.
Digital pulse shape discrimination methods for triple-layer phoswich detectors using wavelets and fuzzy logic.
Degree: MS, Electrical and Computer Engineering, 2008, Oregon State University
URL: http://hdl.handle.net/1957/8935
► A two-channel data acquisition system for simultaneous detection and discrimination of beta particles and gamma rays has been developed. Each channel measures and analyzes the…
(more)
▼ A two-channel data acquisition system for simultaneous detection and discrimination of beta particles and gamma rays has been developed. Each channel measures and analyzes the input pulses resulting from the absorption of radiation in the layers of the detector. The detector is a triple-layer
phoswich (phosphor sandwich) scintillation detector followed by a photomultiplier tube (PMT). The PMT amplifies the photons and converts them into an electric signal. The signal is digitized and sent to the host computer for further processing. Two new digital algorithms based on Fuzzy Logic and on the Continuous Wavelet Transform have been developed and are discussed in this thesis.
In the first method, a de-noising algorithm based on the Wavelet Transform is implemented to reduce the effect of noise introduced by the analog channel and by the photomultiplier tube. Three new timing features are extracted and given as input to a fuzzy interface system. The main goal of fuzziness in a data set is to reduce the system complexity and to provide a model that allows for approximate results. Compared to the method which was originally implemented for this detector, the fuzzy algorithm shows a better performance in separating beta and gamma spectra, especially at high energies. Also, absorption in multiple layers is detected more efficiently.
The second algorithm is based on the Continuous Wavelet Transform. The novelty of this method consists in using scale-domain features. Since the output pulse shape of the photomultiplier tube is a non-stationary signal, conventional Fourier methods are not efficient for analyzing these signals and most of the existing pulse shape discrimination methods use time-domain features. Therefore, a time-frequency space is better suited to analyze these non-stationary signals. This method shows better performance over existing time-domain methods in terms of robustness to noise and reliability.
The simultaneous detection of beta particles and gamma rays has several applications (for instance detection of underground nuclear explosions). The methods presented in this thesis could also be used in alpha/beta/neutron/gamma discrimination systems for cancer diagnosis and treatment.
Advisors/Committee Members: Lucchese, Luca (advisor), Liu, Huaping (committee member).
Subjects/Keywords: Phoswich detector; Scintillation counters
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APA (6th Edition):
Yousefi, S. (2008). Digital pulse shape discrimination methods for triple-layer phoswich detectors using wavelets and fuzzy logic. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/8935
Chicago Manual of Style (16th Edition):
Yousefi, Siavash. “Digital pulse shape discrimination methods for triple-layer phoswich detectors using wavelets and fuzzy logic.” 2008. Masters Thesis, Oregon State University. Accessed March 07, 2021.
http://hdl.handle.net/1957/8935.
MLA Handbook (7th Edition):
Yousefi, Siavash. “Digital pulse shape discrimination methods for triple-layer phoswich detectors using wavelets and fuzzy logic.” 2008. Web. 07 Mar 2021.
Vancouver:
Yousefi S. Digital pulse shape discrimination methods for triple-layer phoswich detectors using wavelets and fuzzy logic. [Internet] [Masters thesis]. Oregon State University; 2008. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1957/8935.
Council of Science Editors:
Yousefi S. Digital pulse shape discrimination methods for triple-layer phoswich detectors using wavelets and fuzzy logic. [Masters Thesis]. Oregon State University; 2008. Available from: http://hdl.handle.net/1957/8935
Texas A&M University
5.
Zarrella, Andrew James.
Pionic Fusion of ⁴He + ¹²C.
Degree: PhD, Chemistry, 2018, Texas A&M University
URL: http://hdl.handle.net/1969.1/174318
► Pionic fusion is the process by which two nuclei collide, undergo complete fusion, and then de-excite solely by the emission of a pion. Previously measured…
(more)
▼ Pionic fusion is the process by which two nuclei collide, undergo complete fusion, and then de-excite solely by the emission of a pion. Previously measured pionic fusion cross sections are inconsistent with known mechanisms for pion production and suggest unknown collective processes might dominate production at low energies in heavy ion collisions. In this work, an experiment was developed to make the first coincident measurement of pionic fusion for a charged pion channel of a reaction for which there are no previous measurements.
The pionic fusion reaction ⁴He (55 MeV/u) + ¹²C → ¹⁶N + π⁺ was studied at the Texas A&M University Cyclotron Institute. The ¹⁶N fusion residues were detected using a dE-E silicon telescope at the focal plane of the MARS spectrometer and the newly designed ParTI
phoswich detector array was used to detect the charged pions. Fast-sampling digitizers recorded the waveform responses of the phoswiches which were used to identify the pions through fast vs. slow (dEE) pulse shape discrimination and through the characteristic decay of the muon daughters of the implanted pions.
An energy calibration method for light charged particles including charged pions is developed for the ParTI
phoswich detectors and the geometrical and particle identification efficiencies of the array are explored. The "muon decay trigger" which was implemented in the firmware of the onboard FPGA in the digitizers is discussed and its ability to increase the pion event selectivity is characterized. A detailed characterization of the transmission efficiency and particle identification capabilities at the focal plane of MARS is also given.
Cross sections are reported for all species detected at the focal plane of MARS and upper limits for the cross section of pionic fusion based on the measurement of ¹⁶N in MARS and charged pions in the ParTI array are reported.
Advisors/Committee Members: Yennello, Sherry J (advisor), Bonasera, Aldo (committee member), Folden, Charles M (committee member), Natowitz, Joseph B (committee member).
Subjects/Keywords: Pionic Fusion; Pion Detection; Phoswich Detector Array
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APA (6th Edition):
Zarrella, A. J. (2018). Pionic Fusion of ⁴He + ¹²C. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174318
Chicago Manual of Style (16th Edition):
Zarrella, Andrew James. “Pionic Fusion of ⁴He + ¹²C.” 2018. Doctoral Dissertation, Texas A&M University. Accessed March 07, 2021.
http://hdl.handle.net/1969.1/174318.
MLA Handbook (7th Edition):
Zarrella, Andrew James. “Pionic Fusion of ⁴He + ¹²C.” 2018. Web. 07 Mar 2021.
Vancouver:
Zarrella AJ. Pionic Fusion of ⁴He + ¹²C. [Internet] [Doctoral dissertation]. Texas A&M University; 2018. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/1969.1/174318.
Council of Science Editors:
Zarrella AJ. Pionic Fusion of ⁴He + ¹²C. [Doctoral Dissertation]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/174318
6.
Hamonet, Margaux.
Tomographie hybride simultanée TEP/TDM combinant détecteurs à pixels hybrides et modules phoswich à scintillateurs : Development of a simultaneous PET/CT scanner for mice combining hybrid pixels detectors and phoswich scintillators modules.
Degree: Docteur es, Instrumentation, 2016, Aix Marseille Université
URL: http://www.theses.fr/2016AIXM4012
► Le mise en commun de la tomographie par émission de positons (TEP) et de la tomodensitométrie (TDM) sur des scanner bimodaux TEP/TDM a été un…
(more)
▼ Le mise en commun de la tomographie par émission de positons (TEP) et de la tomodensitométrie (TDM) sur des scanner bimodaux TEP/TDM a été un axe de recherche essentiel en imagerie ces vingt dernières années et a mené à un développement rapide de cette technique en clinique et en pré-clinique. Cependant, même si les deux modalités peuvent être juxtaposées sur le même statif, l’idée originelle de David W. Townsend prévoyait d’acquérir de manière simultanée les données TEP et TDM provenant du même champ de vue. Cela devrait permettre de connaître la position exacte du sujet lors de l’acquisition, et donc potentiellement de corriger de ses mouvements. C’est dans cet optique que nous avons développé le prototype ClearPET/XPAD : le premier scanner TEP/TDM simultané combinant les modules phoswich à scintillateurs du prototype ClearPET et un détecteur à pixels hybride développé au CPPM faisant face à une source de rayons X sur le même rotateur. Je présente les premières images TEP/CT simultanées de source ponctuelles, du fantôme Derenzo et d’une souris vivante acquises sur le prototype ClearPET/XPAD et discute les limites et les particularités de l’imagerie hybride TEP/TDM simultanée.
The combination of Positron Emission Tomography (PET) and X-ray Computerized Tomographie (CT) for PET/CT imaging has been an essential line of research in the previous decades and led to a rapid expansion of this technique in clinics and preclinics. However, even if the two modalities can be juxtaposed on the same gantry, the original concept invented by David W. Townsend foresaw to do both PET and CT imaging at the same time, while imaging a common Field-Of-View (FOV). This will allow to know the exact position of the animal during the scan and possibly to correct for the animal movements. Therefore we developed the ClearPET/XPAD prototype: the first simultaneous PET/CT scanner for mice combining on the same gantry ClearPET modules and the hybrid pixels camera XPAD3 facing an X-ray source. I present the first simultaneous PET/CT scans of point sources, of the Derenzo phantom and of a living mouse acquired with the ClearePET/XPAD prototype and discuss the limitations and prospects of simultaneous hybrid PET/CT imaging.
Advisors/Committee Members: Morel, Christian (thesis director).
Subjects/Keywords: Tep; Tdm; Tomographie bimodale simultanée; Modules phoswich; Détecteur à pixels hybrides; Pet; Ct; Simultaneous bimodal tomography; Phoswich scintillators modules; Hybrid pixels detectors; 530
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APA (6th Edition):
Hamonet, M. (2016). Tomographie hybride simultanée TEP/TDM combinant détecteurs à pixels hybrides et modules phoswich à scintillateurs : Development of a simultaneous PET/CT scanner for mice combining hybrid pixels detectors and phoswich scintillators modules. (Doctoral Dissertation). Aix Marseille Université. Retrieved from http://www.theses.fr/2016AIXM4012
Chicago Manual of Style (16th Edition):
Hamonet, Margaux. “Tomographie hybride simultanée TEP/TDM combinant détecteurs à pixels hybrides et modules phoswich à scintillateurs : Development of a simultaneous PET/CT scanner for mice combining hybrid pixels detectors and phoswich scintillators modules.” 2016. Doctoral Dissertation, Aix Marseille Université. Accessed March 07, 2021.
http://www.theses.fr/2016AIXM4012.
MLA Handbook (7th Edition):
Hamonet, Margaux. “Tomographie hybride simultanée TEP/TDM combinant détecteurs à pixels hybrides et modules phoswich à scintillateurs : Development of a simultaneous PET/CT scanner for mice combining hybrid pixels detectors and phoswich scintillators modules.” 2016. Web. 07 Mar 2021.
Vancouver:
Hamonet M. Tomographie hybride simultanée TEP/TDM combinant détecteurs à pixels hybrides et modules phoswich à scintillateurs : Development of a simultaneous PET/CT scanner for mice combining hybrid pixels detectors and phoswich scintillators modules. [Internet] [Doctoral dissertation]. Aix Marseille Université 2016. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2016AIXM4012.
Council of Science Editors:
Hamonet M. Tomographie hybride simultanée TEP/TDM combinant détecteurs à pixels hybrides et modules phoswich à scintillateurs : Development of a simultaneous PET/CT scanner for mice combining hybrid pixels detectors and phoswich scintillators modules. [Doctoral Dissertation]. Aix Marseille Université 2016. Available from: http://www.theses.fr/2016AIXM4012
7.
Luo, Yiyan.
Etude de faisabilité d'un détecteur dédié à la discrimination bêta/gamma : Study of the feasibility of a detector dedicated to the beta/gamma discrimination.
Degree: Docteur es, Physique, 2018, Normandie
URL: http://www.theses.fr/2018NORMC291
► A des fins de propreté radiologique, les exploitants nucléaires doivent évaluer l'activité surfacique résiduelle, telle que la contamination bêta. Pour cela, les contaminamètres sont essentiels.…
(more)
▼ A des fins de propreté radiologique, les exploitants nucléaires doivent évaluer l'activité surfacique résiduelle, telle que la contamination bêta. Pour cela, les contaminamètres sont essentiels. Dans ce cadre, EDF R&D a proposé un projet de recherche visant à étudier la faisabilité d’un contaminamètre innovant permettant de détecter l’activité surfacique bêta in situ, alors qu’elle est actuellement mesurée ex-situ.L'objectif principal de ce travail est de détecter une contamination bêta surfacique de 0,4 Bq/cm2 dans un environnement gamma élevé, jusqu'à 100 µSv/h. Cela exige un détecteur ayant une performance de discrimination bêta/gamma élevée. Plusieurs technologies basées sur un scintillateur et/ou un détecteur à gaz ont été étudiées. Des simulations Geant4 ont été effectuées pour optimiser la configuration des technologies retenues (géométrie, matériaux, etc.). Suite à ces simulations, deux prototypes, de type Phoswich, optimisés ont été fabriqués et testés à l’aide de sources bêta et gamma au laboratoire ( LPC Caen). En outre, deux campagnes d’essai ont été menées dans une centrale nucléaire (CNPE de Chinon) afin d'évaluer les performances des prototypes développés dans un bruit de fond gamma réaliste. Les simulations Geant4 et les tests sont discutés dans cette thèse.
For radiological cleanliness purpose, nuclear operators have to assess surface residual activity such as beta contamination. To this aim, contamination monitors are essential. In this context, EDF R&D proposed a research project in order to study the feasibility of an innovative contamination monitor to detect beta surface activity in situ which is until now performed ex situ. The main objective is to detect a 0.4 Bq/cm2 beta surface contamination in a high gamma background up to 100 μSv/h. This demands the detector to have a high beta/gamma discrimination performance. Several technologies based on scintillator and/or gas filled detector have been investigated. Geant4 simulations have been carried out to optimise the configuration of the chosen detector such as geometry, materials, etc. Two simulation-optimised prototypes based on Phoswich detectors have been developed and tested with beta and gamma sources in a laboratory framework (LPC Caen). Furthermore, two experimental campaigns have been conducted in a nuclear power plant (NPP of Chinon) in order to evaluate the performance of the developed prototypes in a realistic gamma background environment. The Geant4 simulations and the experimental work are discussed in this thesis.
Advisors/Committee Members: Labalme, Marc (thesis director).
Subjects/Keywords: Activité surfacique bêta; Discrimination bêta/gamma; Simulation Geant4; Contaminamètre; Détecteur Phoswich; Contamination monitor; Beta surface activity; Beta/gamma discrimination; Geant4 simulation; Phoswich detector; Gas detector
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APA (6th Edition):
Luo, Y. (2018). Etude de faisabilité d'un détecteur dédié à la discrimination bêta/gamma : Study of the feasibility of a detector dedicated to the beta/gamma discrimination. (Doctoral Dissertation). Normandie. Retrieved from http://www.theses.fr/2018NORMC291
Chicago Manual of Style (16th Edition):
Luo, Yiyan. “Etude de faisabilité d'un détecteur dédié à la discrimination bêta/gamma : Study of the feasibility of a detector dedicated to the beta/gamma discrimination.” 2018. Doctoral Dissertation, Normandie. Accessed March 07, 2021.
http://www.theses.fr/2018NORMC291.
MLA Handbook (7th Edition):
Luo, Yiyan. “Etude de faisabilité d'un détecteur dédié à la discrimination bêta/gamma : Study of the feasibility of a detector dedicated to the beta/gamma discrimination.” 2018. Web. 07 Mar 2021.
Vancouver:
Luo Y. Etude de faisabilité d'un détecteur dédié à la discrimination bêta/gamma : Study of the feasibility of a detector dedicated to the beta/gamma discrimination. [Internet] [Doctoral dissertation]. Normandie; 2018. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2018NORMC291.
Council of Science Editors:
Luo Y. Etude de faisabilité d'un détecteur dédié à la discrimination bêta/gamma : Study of the feasibility of a detector dedicated to the beta/gamma discrimination. [Doctoral Dissertation]. Normandie; 2018. Available from: http://www.theses.fr/2018NORMC291
University of Texas – Austin
8.
Ward, Rebecca Morgan.
Comparison of the phoswich and ARSA-type detectors for radioxenon detection.
Degree: MSin Engineering, Mechanical Engineering, 2010, University of Texas – Austin
URL: http://hdl.handle.net/2152/ETD-UT-2010-05-1016
► The Comprehensive Nuclear Test Ban Treaty verification regime mandates atmospheric monitoring for the four radioxenon isotopes that are produced in high abundance in a nuclear…
(more)
▼ The Comprehensive Nuclear Test Ban Treaty verification regime mandates atmospheric monitoring for the four radioxenon isotopes that are produced in high abundance in a nuclear explosion: [superscript 131m]Xe, [superscript 133m]Xe, [superscript 133g]Xe, and [superscript 135g]Xe. This mandate has driven the development of improved xenon detectors, including a
phoswich detector, which has potential to replace the ARSA detector in the International Monitoring System. In this experiment, the four relevant radioxenon isotopes were produced through neutron activation and the
phoswich detector was used to attain spectra from the gas. Spectral characteristics and resolution of the
phoswich spectra were compared to an ARSA-type [beta]-[gamma] coincidence detector to perform an overall evaluation of the
phoswich detector. The results indicated that spectral characteristics and resolutions for the
phoswich were comparable to the ARSA-type detector, with slightly improved beta detection. As an additional test of the new detector's capabilities, a tailored spectrum designed to mimic a nuclear explosion signature was produced and analyzed with the detector.
Advisors/Committee Members: Biegalski, Steven R. (advisor), Haas, Derek (committee member).
Subjects/Keywords: Radioxenon; Atmospheric monitoring; Beta-gamma coincidence; Phoswich
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APA (6th Edition):
Ward, R. M. (2010). Comparison of the phoswich and ARSA-type detectors for radioxenon detection. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/ETD-UT-2010-05-1016
Chicago Manual of Style (16th Edition):
Ward, Rebecca Morgan. “Comparison of the phoswich and ARSA-type detectors for radioxenon detection.” 2010. Masters Thesis, University of Texas – Austin. Accessed March 07, 2021.
http://hdl.handle.net/2152/ETD-UT-2010-05-1016.
MLA Handbook (7th Edition):
Ward, Rebecca Morgan. “Comparison of the phoswich and ARSA-type detectors for radioxenon detection.” 2010. Web. 07 Mar 2021.
Vancouver:
Ward RM. Comparison of the phoswich and ARSA-type detectors for radioxenon detection. [Internet] [Masters thesis]. University of Texas – Austin; 2010. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2152/ETD-UT-2010-05-1016.
Council of Science Editors:
Ward RM. Comparison of the phoswich and ARSA-type detectors for radioxenon detection. [Masters Thesis]. University of Texas – Austin; 2010. Available from: http://hdl.handle.net/2152/ETD-UT-2010-05-1016
University of Michigan
9.
Bush-Goddard, Stephanie Paulette.
Beta spectroscopy using deconvolution and spectral stripping techniques with a triple layer phoswich detector.
Degree: PhD, Pure Sciences, 2000, University of Michigan
URL: http://hdl.handle.net/2027.42/132314
► The overall objective of this research was to identify and quantify beta-emitting radionuclides in a mixed beta radiation field. The first and second objectives were…
(more)
▼ The overall objective of this research was to identify and quantify beta-emitting radionuclides in a mixed beta radiation field. The first and second objectives were to design a triple layer
phoswich detector and to generate electron response functions using the Monte Carlo code, Electron Gamma Shower Four (EGS4). In the third objective, the pure beta emitting radionuclides of
63Ni,
99Tc, and
90Sr/Y were measured for comparing to modeled data. The final objective was to develop a deconvolution and spectral stripping technique to separate measured and modeled spectra into constituent betaemission spectra for the purpose of nuclide identification. The detector is 5.08 cm in diameter and 9.06 mm thick. It has a mylar window with a density thickness of 0.75 mg/cm
2. The first and third layers are vinyltoluene-based scintillators (BC-400, and BC-444), the second layer is made of CaF
2 (Eu), an inorganic scintillator. The assembly is coupled to a EMI 9266 photomultiplier tube. A total of seventy-seven mono-energetic response functions were modeled in the EGS4 code to obtain deposition characteristics. These response functions were convolved and deconvolved. with the source and measured spectra. The largest relative difference when comparing the source and deconvolved spectra of
63Ni was at the 50 keV energy bin with a difference of 1.65%. The highest relative difference between the measured and convolved spectra was at 15 keV with a difference of 1.83%. For
99Tc, the largest difference between the source and deconvolved. spectra was at 300 keV with a difference of 1.4%. The largest difference between the measured and convolved spectra at was at 60 keV with a difference of 1.6%. For
90Sr/Y, the largest difference between the source and deconvolved spectra was at 2.25 MeV with a difference of 2.0%. The largest difference between the measured and convolved spectra was at 1.0 MeV with a difference of 3.0%. Overall the relative differences showed good agreement with the major sources of error arising from calibration issues and non-linear light output for the organic phosphors below 125 keV. Overall, this research established identifying beta emitting radionuclides in a mixed beta radiation field using a
phoswich detector.
Advisors/Committee Members: Hamby, David M. (advisor).
Subjects/Keywords: Beta Spectroscopy; Deconvolution; Layer; Phoswich Detector; Spectral Stripping; Techniques; Triple; Using
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APA (6th Edition):
Bush-Goddard, S. P. (2000). Beta spectroscopy using deconvolution and spectral stripping techniques with a triple layer phoswich detector. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/132314
Chicago Manual of Style (16th Edition):
Bush-Goddard, Stephanie Paulette. “Beta spectroscopy using deconvolution and spectral stripping techniques with a triple layer phoswich detector.” 2000. Doctoral Dissertation, University of Michigan. Accessed March 07, 2021.
http://hdl.handle.net/2027.42/132314.
MLA Handbook (7th Edition):
Bush-Goddard, Stephanie Paulette. “Beta spectroscopy using deconvolution and spectral stripping techniques with a triple layer phoswich detector.” 2000. Web. 07 Mar 2021.
Vancouver:
Bush-Goddard SP. Beta spectroscopy using deconvolution and spectral stripping techniques with a triple layer phoswich detector. [Internet] [Doctoral dissertation]. University of Michigan; 2000. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2027.42/132314.
Council of Science Editors:
Bush-Goddard SP. Beta spectroscopy using deconvolution and spectral stripping techniques with a triple layer phoswich detector. [Doctoral Dissertation]. University of Michigan; 2000. Available from: http://hdl.handle.net/2027.42/132314
Université de Sherbrooke
10.
Bouziri, Haithem.
Identification de cristaux dans un phoswich par la méthode de mesure de temps au dessus d'un seuil (ToT) pour le scanner LabPET II.
Degree: 2014, Université de Sherbrooke
URL: http://hdl.handle.net/11143/6157
► La performance d’un scanner TEP se mesure par sa sensibilité, son contraste et sa résolution spatiale. Cette dernière doit être idéalement uniforme dans tout le…
(more)
▼ La performance d’un scanner TEP se mesure par sa sensibilité, son contraste et sa résolution spatiale. Cette dernière doit être idéalement uniforme dans tout le champ de vue utile (CDV) du scanner. Cependant, le problème de parallaxe dû à l’éloignement de la source du centre de CDV, entraîne une dégradation de la résolution spatiale radiale. Ce problème est très présent dans les scanners avec une grande densité de détecteurs et de petit diamètre notamment dans le LabPET II, le scanner en cours de développement à l’Université de Sherbrooke par le Groupe de recherche en appareillage médicale de Sherbrooke (GRAMS) et le Centre d’imagerie moléculaire de Sherbrooke (CIMS), avec [tilde]37 000 détecteurs pour un CDV de 16 cm de diamètre et 12 cm de longueur axiale. Chaque détecteur a une surface de 1,2[indice supérieur *] 1,2 mm[indice supérieur 2] et une longueur supérieure à 10 mm. La mesure de profondeur d’interaction (PDI) demeure très utile pour résoudre le problème de parallaxe. La PDI peut être réalisée par l’assemblage de deux cristaux en
phoswich, tout en gardant la même longueur totale pour assurer une bonne efficacité de détection, et puis, le cristal dans lequel une interaction est faite sera déterminé à l’aide d’algorithme d’identification de cristaux. Pour le traitement des signaux issus des modules de détection, un ASIC de 64 canaux a été développé. L’ASIC utilise une nouvelle technique de mesure de temps à doubles seuils inspirée de la technique de mesure de temps au-dessus d’un seuil (ToT). Cette technique repose sur l’utilisation de deux discriminateurs à seuil afin de déterminer le temps d’arrivée du photon d’annihilation et son énergie. Le temps d’arrivée est estimé par le moment de discrimination du signal avec le premier discriminateur. Tandis que l’énergie du signal est calculée par la différence des moments de discrimination du signal avec le premier et le deuxième discriminateur. Cette différence de temps est non linéaire en fonction de l’énergie. Donc une correction d’énergie est faite pour déterminer le spectre d’énergie. Les seuils des discriminateurs sont méticuleusement choisis afin de minimiser l’erreur sur les temps de croisement. Cette méthode de ToT à doubles seuils est une technique innovatrice pour identifier les cristaux qui ont scintillés [i.e. scintillé] dans un scanner TEP. Avec une erreur inférieure à 5%, cette technique discrimine entre un LGS045ns et un LYSO40ns. Malgré le taux d’erreur élevé comparé à d’autres méthodes d’identification, cette technique possède l’avantage d’être facilement intégrable dans l’ASIC du LabPET II.
Advisors/Committee Members: Fontaine, Réjean (advisor).
Subjects/Keywords: LabPET II; ASIC; Détecteur phoswich; Identification de cristaux; Mesure du temps au-dessus d’un seuil; Résolution spatiale; Profondeur d’interaction; Parallaxe; Tomographie d’émission par positrons
Record Details
Similar Records
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Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bouziri, H. (2014). Identification de cristaux dans un phoswich par la méthode de mesure de temps au dessus d'un seuil (ToT) pour le scanner LabPET II. (Masters Thesis). Université de Sherbrooke. Retrieved from http://hdl.handle.net/11143/6157
Chicago Manual of Style (16th Edition):
Bouziri, Haithem. “Identification de cristaux dans un phoswich par la méthode de mesure de temps au dessus d'un seuil (ToT) pour le scanner LabPET II.” 2014. Masters Thesis, Université de Sherbrooke. Accessed March 07, 2021.
http://hdl.handle.net/11143/6157.
MLA Handbook (7th Edition):
Bouziri, Haithem. “Identification de cristaux dans un phoswich par la méthode de mesure de temps au dessus d'un seuil (ToT) pour le scanner LabPET II.” 2014. Web. 07 Mar 2021.
Vancouver:
Bouziri H. Identification de cristaux dans un phoswich par la méthode de mesure de temps au dessus d'un seuil (ToT) pour le scanner LabPET II. [Internet] [Masters thesis]. Université de Sherbrooke; 2014. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/11143/6157.
Council of Science Editors:
Bouziri H. Identification de cristaux dans un phoswich par la méthode de mesure de temps au dessus d'un seuil (ToT) pour le scanner LabPET II. [Masters Thesis]. Université de Sherbrooke; 2014. Available from: http://hdl.handle.net/11143/6157
Université de Sherbrooke
11.
Yousefzadeh, Hoorvash Camilia.
Identification des cristaux dans un détecteur Phoswich appliqué à la tomographie d'émission par positrons.
Degree: 2010, Université de Sherbrooke
URL: http://hdl.handle.net/11143/5798
► La tomographie d'émission par positrons (TEP) occupe une place de choix dans le domaine de l'imagerie moléculaire par sa capacité d'obtenir des informations ultrasensibles et…
(more)
▼ La tomographie d'émission par positrons (TEP) occupe une place de choix dans le domaine de l'imagerie moléculaire par sa capacité d'obtenir des informations ultrasensibles et quantitatives sur des processus métaboliques, physiologiques ou cellulaires. De plus, grâce à la similitude des génomes de l'homme et de petits rongeurs comme la souris, elle attire un grand intérêt dans le domaine de la recherche médicale, allant de la détection précoce de différentes formes de cancers jusqu'au développement de nouveaux médicaments. Toutefois, pour tirer profit des images acquises lors d'études animales, des scanners de plus en plus performants sont nécessaires. Le LabPETTM, le scanner TEP petit animal conçu par les efforts unis du Groupe de recherche en appareillage médicale de Sherbrooke (GRAMS) et du Centre d'imagerie moléculaire de Sherbrooke (CIMS) se démarque des autres scanners d'une part par son couplage individuel des photodiodes à avalanche à une paire de cristaux scintillateurs et d'autre part par une numérisation hâtive des signaux et un traitement numérique parallèle. Cela permet d'y implanter des algorithmes de traitement de signaux puissants. Le filtre de Wiener est une des techniques utilisées dans le LabPETTM pour optimiser à la fois le rendement et la capacité d'identification du cristal (IC) excité par le rayonnement émis dans le scanner par les radioisotopes. Les travaux de cette thèse portent, dans une première partie, sur le développement et l'implantation d'une version plus complète et ajustée de la méthode d'IC basée sur le filtre de Wiener. L'amélioration de cette technique porte sur l'utilisation des deux caractéristiques élémentaires des cristaux, soit leur constante de temps et leur rendement lumineux pour une IC plus précise et rapide. Une telle IC peut être réalisée même avec des cristaux possédant des caractéristiques très similaires, et pour des énergies très basses - jusqu'à 100 keV. Dans une deuxième partie, les performances de la méthode d'IC Wiener ont été évaluées en tenant compte de la contribution des différentes sources de bruit de la chaîne d'acquisition d'un scanner TEP. L'influence du bruit de multiplication de la photodiode à avalanche (un bruit non-stationnaire et poissonien), le bruit électronique (un bruit stationnaire et gaussien), ainsi que l'effet de l'utilisation des filtres de mise en forme rapide CR-RC n sur les résultats de l'algorithme d'IC ont été étudiés grâce au développement d'un simulateur de TEP qui imite les signaux de sortie du LabPETTM. Finalement, la possibilité d'utiliser la méthode d'IC Wiener pour discriminer des détecteurs multicouches, composés de trois et quatre cristaux, a été étudiée. L'implantation de cet algorithme dans un scanner TEP permettra à court terme d'améliorer les performances de démultiplexage des détecteurs et, de ce fait, la résolution spatiale axiale du système. Des techniques de modélisations du bruit non-stationnaire sont proposées pour rehausser les résultats de l'algorithme d'IC. En se basant sur les résultats de l'algorithme d'IC, il…
Advisors/Committee Members: Fontaine, Réjean (advisor), Lecomte, Roger (advisor).
Subjects/Keywords: Tomographie d'émissions par positrons (TEP); Sensibilité; Résolution spatiale; Diffusions Compton; Détecteurs phoswich; Identification des cristaux
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Yousefzadeh, H. C. (2010). Identification des cristaux dans un détecteur Phoswich appliqué à la tomographie d'émission par positrons. (Doctoral Dissertation). Université de Sherbrooke. Retrieved from http://hdl.handle.net/11143/5798
Chicago Manual of Style (16th Edition):
Yousefzadeh, Hoorvash Camilia. “Identification des cristaux dans un détecteur Phoswich appliqué à la tomographie d'émission par positrons.” 2010. Doctoral Dissertation, Université de Sherbrooke. Accessed March 07, 2021.
http://hdl.handle.net/11143/5798.
MLA Handbook (7th Edition):
Yousefzadeh, Hoorvash Camilia. “Identification des cristaux dans un détecteur Phoswich appliqué à la tomographie d'émission par positrons.” 2010. Web. 07 Mar 2021.
Vancouver:
Yousefzadeh HC. Identification des cristaux dans un détecteur Phoswich appliqué à la tomographie d'émission par positrons. [Internet] [Doctoral dissertation]. Université de Sherbrooke; 2010. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/11143/5798.
Council of Science Editors:
Yousefzadeh HC. Identification des cristaux dans un détecteur Phoswich appliqué à la tomographie d'émission par positrons. [Doctoral Dissertation]. Université de Sherbrooke; 2010. Available from: http://hdl.handle.net/11143/5798
. 
Open Access Theses and Dissertations
