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Dissertations / Theses on the topic 'High purity germanium detectors'

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Published: 4 June 2021

Last updated: 17 February 2022

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1

Ginsz, Michaël. "Characterization of high-purity, multi-segmented germanium detectors." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAE047/document.

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L’apparition de la segmentation électrique des détecteurs au GeHP et de l’électronique numérique a ouvert la voie à des applications prometteuses, telles que le tracking γ, l’imagerie γ ou la mesure bas bruit de fond, pour lesquelles une connaissance fine de la réponse du détecteur est un atout. L’IPHC a développé une table de scan utilisant un faisceau collimaté, qui sonde la réponse d’un détecteur dans tout son volume en fonction de la localisation de l’interaction. Elle est conçue pour utiliser une technique innovante de scan 3D, le Pulse Shape Comparison Scan, qui a été d’abord simulée afin de démontrer son efficacité. Un détecteur AGATA a été scanné de manière approfondie. Des scan 2D classiques ont permis, entre autres, de mettre en évidence des effets locaux de modification de la collection des charges, liés à la segmentation. Pour la première fois, une base de données 3D, complète, de formes d’impulsions fonction de la position d’interaction a été établie. Elle permettra notamment d’améliorer les performances du spectromètre AGATA<br>Recent developments of electrical segmentation of HPGe detectors, coupled with digital electronics have led to promising applications such as γ-ray tracking, γ-ray imaging or low-background measurements which will benefit from a fine knowledge of the detector response. The IPHC has developed a new scanning table which uses a collimated γ-ray beam to investigate the detector response as a function of the location of the γ-ray interaction. It is designed to use the Pulse Shape Comparison Scan technique, which has been simulated in order to prove its efficiency. An AGATA detector has been thoroughly scanned. 2D classical scans brought out, for example, local charge collection modification effects such as charge sharing, due to the segmentation. For the first time, a 3D, complete pulse-shape database has been established. It will especially allow to improve the overall AGATA array performances

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2

Colosimo, Samantha. "The characterisation of AGATA high purity germanium detectors for pulse shape analysis." Thesis, University of Liverpool, 2013. http://livrepository.liverpool.ac.uk/11077/.

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Gamma-ray spectroscopy is an essential tool in the study of nuclear phenomenon. The study of exotic nuclei and nuclear states have been used to expand the nuclear chart as well as understand the origin of the universe. Large volume high purity germanium arrays, very high beam intensities and more recently exotic beams have lead to new understanding of nuclear physics. The Advanced Gamma Tracking Array (AGATA) aims to utilise high purity germanium (HPGe) detectors in order to achieve a dramatic increase in efficiency over current spectrometers. The work detailed in this thesis shows a highly detailed characterisation of two AGATA asymmetric capsules of the same shape in order to test and compare performances. Detector A004 was acceptance tested and scanned at the University of Liverpool in February 2010. Detector A006 was scanned between April and September 2010. Resolution, efficiency and charge collection parameters have been studied, comparing these two detector. The results of the comparison show an excellent agreement between the performance of the two detectors. The depletion rate of the detectors has also been compared quantitatively indicating the dependence of depletion on impurity concentration of the capsules. An experimental pulse shape database was generated for detector A006. The sensitivity of the detector response was quantified indicating the regions of the detector of high variation in pulse shape response. The AGATA detector library, which used to simulate the detector response for pulse shape analysis, is compared with this database. The position resolution achieved between the two data sets has been calculated. The combination of the detailed comparison and characterisation of the detector with the study of the simulate database will provide the AGATA collaboration with useful information to improve detector simulations in the further for pulse shape analysis.

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3

Nelson, Justin Matthew 1981. "Total-to-peak ratios of high purity germanium gamma ray detector." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32746.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics; and, (S.B.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2004.<br>MIT Institute Archives copy: leaves 2-22 bound in reverse order.<br>Includes bibliographical references (leaf 22).<br>This study is concerned with the percentage of [gamma]-rays of a certain energy having their energy correctly measured by a high purity Germanium [gamma]-ray detector. The ratio between the total counts and the counts within the energy peak (total-to-peak ratio) is determined for seven energies ranging from 89 keV to 1275 keV. A Monte Carlo based on the physical parameters of the detector was used to extrapolate between these points and after an energy independent scaling factor fit the data with a reduced [chi]² slightly below 1. The same experiment was repeated with a lead brick and then a β detector near the Ge detector and these objects were found to not have an effect on the total-to-peak ratios within the precision of the experiment.<br>by Justin Matthew Nelson.<br>S.B.

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4

Gamir, Luis Palafox. "A new method for the determination of the entry position of #gamma#-rays in high purity germanium detectors by current pulse analysis." Thesis, Cranfield University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387640.

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5

Palafox, Gamir Luis. "A new method for the determination of the entry position of y-rays [gamma rays] in high purity germanium detectors by current pulse analysis." Thesis, Cranfield University, 1997. http://hdl.handle.net/1826/850.

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A new method for determining the entry point of gamma-rays in closed ended HPGe detectors has been developed. Exploiting the position dependence shown by the current pulses generated when a gamma-ray interacts with the detector, it is possible to electronically divide the crystal in the radial coordinate and thus increase the effective granularity of the detector. Position resolution is particularly important for correcting the Doppler peak broadening observed in many in-beam gamma-spectroscopy experiments. Position resolution within coaxial crystals is accomplished by combining the angular information gained by segmenting the outer contact with the determination of the event radius by current pulse shape analysis. With increasing gamma-energy, more than one interaction is in general required to completely stop a gamma-ray in a germanium detector. The concept of a main interaction, defined as that depositing the largest fraction of the original gamma-energy, is introduced and seen to be the dominant contribution to the event current pulses. A Monte Carlo simulation for the positions and energies of the interactions in an event has been performed in order to establish the physical limits for the position resolution that can be measured in a segmented CLUSTER module. A varying fraction of events, from 55% at a gamma-energy of 400 keV to 85% at 1800 keV, have their main interaction within 5 mm from the entry point. The position of the main interaction can therefore be successfully used to measure the entry position of the gamma-ray in the detector. In order to provide high quality charge/energy and current outputs from the detector signal, a new preamplifier for large volume HPGe detectors has been developed. The intrinsic equivalent noise contribution from the preamplifier was measured at 0.65 keV + 35 eV /pF. The measured energy resolution when the input FET is operated at cryogenic temperature is 2.30 keV at 1333 keV with 3 μs shaping time. Using this preamplifier and the first prototype of a two-fold segmented CLUSTER module, a radial resolution of ±4mm has been measured with the new method both at 662 and 1333 keV. The method can be incorporated into an analogue electronic circuit and is therefore directly applicable in in-beam gamma- spectroscopy experiments.

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6

Palafox, Gamir Luis. "A new method for the determination of the entry position of γ-rays [gamma rays] in high purity germanium detectors by current pulse analysis". Thesis, Cranfield University, 1997. http://dspace.lib.cranfield.ac.uk/handle/1826/850.

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A new method for determining the entry point of gamma-rays in closed ended HPGe detectors has been developed. Exploiting the position dependence shown by the current pulses generated when a gamma-ray interacts with the detector, it is possible to electronically divide the crystal in the radial coordinate and thus increase the effective granularity of the detector. Position resolution is particularly important for correcting the Doppler peak broadening observed in many in-beam gamma-spectroscopy experiments. Position resolution within coaxial crystals is accomplished by combining the angular information gained by segmenting the outer contact with the determination of the event radius by current pulse shape analysis. With increasing gamma-energy, more than one interaction is in general required to completely stop a gamma-ray in a germanium detector. The concept of a main interaction, defined as that depositing the largest fraction of the original gamma-energy, is introduced and seen to be the dominant contribution to the event current pulses. A Monte Carlo simulation for the positions and energies of the interactions in an event has been performed in order to establish the physical limits for the position resolution that can be measured in a segmented CLUSTER module. A varying fraction of events, from 55% at a gamma-energy of 400 keV to 85% at 1800 keV, have their main interaction within 5 mm from the entry point. The position of the main interaction can therefore be successfully used to measure the entry position of the gamma-ray in the detector. In order to provide high quality charge/energy and current outputs from the detector signal, a new preamplifier for large volume HPGe detectors has been developed. The intrinsic equivalent noise contribution from the preamplifier was measured at 0.65 keV + 35 eV /pF. The measured energy resolution when the input FET is operated at cryogenic temperature is 2.30 keV at 1333 keV with 3 μs shaping time. Using this preamplifier and the first prototype of a two-fold segmented CLUSTER module, a radial resolution of ±4mm has been measured with the new method both at 662 and 1333 keV. The method can be incorporated into an analogue electronic circuit and is therefore directly applicable in in-beam gamma-spectroscopy experiments.

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Volynets, Oleksandr [Verfasser], Bela [Akademischer Betreuer] Majorovits, Peter [Akademischer Betreuer] Fierlinger, and Alejandro [Akademischer Betreuer] Ibarra. "Methods to improve and understand the sensitivity of high purity germanium detectors for searches of rare events / Oleksandr Volynets. Gutachter: Peter Fierlinger ; Alejandro Ibarra. Betreuer: Bela Majorovits." München : Universitätsbibliothek der TU München, 2012. http://d-nb.info/1025337832/34.

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Ljungvall, Joa. "Characterisation of the Neutron Wall and of Neutron Interactions in Germanium-Detector Systems." Doctoral thesis, Uppsala University, Department of Nuclear and Particle Physics, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5845.

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<p>A Monte Carlo simulation of the Neutron Wall detector system has been performed using Geant4, in order to define optimum conditions for the detection and identification of multiple neutrons. Emphasis was put on studying the scattering of neutrons between different detectors, which is the main source of the apparent increase of the number of detected neutrons. The simulation has been compared with experimental data. The quality of neutron gated γ-ray spectra was improved for both two- and three-neutron evaporation channels. The influence of small amounts of γ rays mis-interpreted as neutrons was investigated. It was found that such γ rays dramatically reduce the quality of neutron gated γ-ray spectra.</p><p>The interaction properties of fast neutrons in a closed-end coaxial and a planar high-purity germanium detector (HPGe) were studied. Digitised waveforms of HPGe preamplifier signals were recorded for time-of-flight separated neutrons and γ rays, emitted by a <sup>252</sup>Cf source. The experimental waveforms from the detectors were compared to simulated pulse shapes. In the analysis, special emphasis was given to the detection of elastically scattered neutrons, which may be an important effect to take into account in future spectrometers based on γ-ray tracking. No differences between neutron and γ-ray induced pulse shapes were found in this work.</p><p>A Monte Carlo simulation of the interactions of fast neutrons in the future 4π γ-ray spectrometer AGATA was also performed, in order to study the influence of neutrons on γ-ray tracking. It was shown that although there is a large probability of detecting neutrons in AGATA, the neutrons decrease the photo-peak efficiency of AGATA by only about 1% for each neutron emitted in coincidence with γ rays. The peak-to-background ratios in γ-ray spectra are, however, reduced to a much larger extent. The possibility of using AGATA as a neutron detector system was also investigated.</p>

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Foerster, Nadine [Verfasser], and J. [Akademischer Betreuer] Blümer. "Detector optimization based on studies of charge migration in the high purity germanium crystals of the EDELWEISS dark matter experiment / Nadine Foerster ; Betreuer: J. Blümer." Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1129258793/34.

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De, Canditiis Bartolomeo. "3D characterization of multi-segmented HPGe detectors : simulation and validation of the PSCS technique and its application for different energies with a 152 Eu source." Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAE008.

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Les ensembles de détecteurs de rayon gamma de nouvelle génération, tel AGATA, utilisent des détecteurs multi-segmentés de germanium hyper-pur dans les expériences de physique nucléaire pour lesquelles une grande résolution et efficacité sont demandées. Ces caractéristiques sont obtenues par l’application des techniques d'analyse des formes d'impulsion et de tracking des rayons gamma. Ces dernières demandent une caractérisation volumétrique des détecteurs. À cet effet, l'IPHC a développé une table de scan qui utilise la technique Pulse Shape Comparison Scan (PSCS). Des simulations sont réalisées pour quantifier la précision de la technique PSCS et pour la valider. Elles sont appliquées sur un détecteur planaire pixelisé 3x3 et sur un détecteur symétrique d'AGATA de type S. La méthode est testée avec plusieurs énergies de rayons gamma et diverses statistiques d'entrée. Des scans réels sont aussi entrepris sur les deux détecteurs, qui sont totalement caractérisés. En particulier, un scan réalisé pour la première fois avec une source de rayons gamma de 152Eu, prouve la validité de certaines hypothèses sur lesquelles repose la technique de tracking<br>New generation gamma-ray detectors arrays, such as AGATA, employ multi-segmented high purity germanium detectors in experiments of nuclear physics that require high resolution and efficiency which are obtained thanks to the application of pulse-shape analysis and gamma-ray tracking. These techniques require full volume characterization of the position sensitive detectors. The IPHC developed a scanning table that uses the Pulse Shape Comparison Scan (PSCS) technique to perform this task. Simulations are performed to quantify the accuracy of the PSCS and to validate it.They are applied on a pixelated 3x3 planar detector and a symmetrical S-type AGATA detector. The method is tested with different gamma-ray energies and input statistics. Several real scans are performed as well on both detectors, which are fully characterized. In particular a scan with agamma-ray source of 152Eu, the first ever done, prove some assumptions on which the tracking technique is based

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Abdualhadi, S. A. "Quantifying disequilibrium in U-series decay using high-purity germanium spectrometry." Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3004531/.

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Many of the naturally occurring radioactive elements are members of radioactive de- cay chains. These chains originate from parent nuclides with very long half-lives and end with a stable nuclide of lead. In any natural material containing uranium which was not disrupted, a state of secular equilibrium will occur between parent nuclide and its daughter products. However, when sedimentary deposits are formed, many geological processes can occur which may cause isotopic fractionation of the elements resulting in a state of disequilibrium between the parent nuclide and its daughters in the chain. This study is aimed at the determination of the activity concentrations of radionuclides from U-series decay and hence quantifying possible disequilibrium in 14 sediment samples selected from four different locations. Six samples were collected from Namibia in the South Africa, four samples were from the Cambridge Gulf in Western Australia and the four remaining samples were from Czech Republic and South Germany regions in Europe. This work was carried out with a novel Broad Energy Germanium (BEGe) detector inside a 50mm thick lead shield. The BEGe detector utilises a novel point like electrode structure which through extremely low capacitance (1pF) provides excellent an energy resolution at low energy. This performance is far superior to conventional germanium detectors, which en- ables a potential step change in the ability to resolve low energy peaks on a background. Gamma-ray energy resulting in excellent spectra. Gamma-ray transitions lines ranging from 46 keV up to 1.7 MeV associated with decay products of the 238U and 232Th decay chains have been analysed separately to obtain more statistically significant overall results. In the measurements of environmental samples using gamma-ray spectrometry, the main concern is a reliable efficiency calibration. This is crucial especially for the analysis of low-energy gamma emitters ( < 100 keV) such as 210Pb (46.5 keV) and 234Th (63.3 keV and 92.6 keV). Modelled efficiency calibrations using the LabSOCS (Laboratory Sourceless Object Calibration Software) were applied within this work. A series of validation tests was performed and evaluated for different sample types, densities and volumes. Using this method, an improvement can be obtained in the reliability of the derived activity concentrations. The sample preparation and the gamma-ray spectroscopic analysis technique are discussed in detail. The specific activities of radionuclides from the 238U decay chain ranged from 16.8 ± 2.3 to 80 ± 5 Bq/kg for 234Th, from 14 ± 3 to 98 ± 6 Bq/kg for 226Ra, from 16.8 ± 0.6 to 116 ± 3 Bq/kg for 214Pb, from 16.6 ± 0.7 to 112 ± 3 for 214Bi and from 15.9 ± 2.6 to 114 ± 8 Bq/kg for 210Pb. Six samples were found to be in disequilibrium as a result of an excess in 226Ra activity concentrations. The 226Ra/238U activity ratio in these samples ranged from 1.22 ± 0.13 to 1.77 ± 0.15. Notably, these samples were collected from an area in Namibia where leaching of radium has taken place. In the remaining samples the results showed secular equilibrium. The activity concentrations of 228Ac ranged from 20.6 ±1.0 to 60.6 ± 2.0 Bq/kg, of 212Pb from 20.0 ± 0.9 to 59.7 ± 2.5 Bq/kg and of 208Tl from 21.1 ± 1.0 to 58.6 ± 2.4 Bq/kg, from 232Th decay chain. All results show secular equilibrium for this decay chain. The results obtained for the uranium and thorium concentrations some of the investigated samples are consistent with mass spectrometry (ICP-MS) and other gamma-ray spectrometry measurements.

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Suarez, Reynold. "Real-time DSP implementation of self-calibrating pulse-shape discriminator for high purity germanium." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Fall2006/r_suarez_120806.pdf.

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MADUAR, MARCELO F. "Desenvolvimento de um codigo computacional aberto de analise quantitativa para determinacao de radionuclideos por espectrometria gama com detectores semicondutores." reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9534.

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SANTOS, ROBERTO M. dos. "Desenvolvimento de um método para obtenção da eficiência de detecção para detectores HPGe em medidas com fontes extensas." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10104.

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MARTINS, FERNANDO P. G. "Medida do espectro de energia dos neutrons no núcleo do reator IPEN/MB-01." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11485.

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BATISTA, WAGNER F. "Determinacao de parametros nucleares do nucleo de sup(127)Te: uma proposta para o ensino de fisica nuclear." reponame:Repositório Institucional do IPEN, 2011. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9949.

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Kolahdouz, Esfahani Mohammadreza. "Application of SiGe(C) in high performance MOSFETs and infrared detectors." Doctoral thesis, KTH, Integrerade komponenter och kretsar, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32049.

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Epitaxially grown SiGe(C) materials have a great importance for many device applications. In these applications, (strained or relaxed) SiGe(C) layers are grown either selectively on the active areas, or on the entire wafer. Epitaxy is a sensitive step in the device processing and choosing an appropriate thermal budget is crucial to avoid the dopant out–diffusion and strain relaxation. Strain is important for bandgap engineering in (SiGe/Si) heterostructures, and to increase the mobility of the carriers. An example for the latter application is implementing SiGe as the biaxially strained channel layer or in recessed source/drain (S/D) of pMOSFETs. For this case, SiGe is grown selectively in recessed S/D regions where the Si channel region experiences uniaxial strain.The main focus of this Ph.D. thesis is on developing the first empirical model for selective epitaxial growth of SiGe using SiH2Cl2, GeH4 and HCl precursors in a reduced pressure chemical vapor deposition (RPCVD) reactor. The model describes the growth kinetics and considers the contribution of each gas precursor in the gas–phase and surface reactions. In this way, the growth rate and Ge content of the SiGe layers grown on the patterned substrates can be calculated. The gas flow and temperature distribution were simulated in the CVD reactor and the results were exerted as input parameters for the diffusion of gas molecules through gas boundaries. Fick‟s law and the Langmuir isotherm theory (in non–equilibrium case) have been applied to estimate the real flow of impinging molecules. For a patterned substrate, the interactions between the chips were calculated using an established interaction theory. Overall, a good agreement between this model and the experimental data has been presented. This work provides, for the first time, a guideline for chip manufacturers who are implementing SiGe layers in the devices.The other focus of this thesis is to implement SiGe layers or dots as a thermistor material to detect infrared radiation. The result provides a fundamental understanding of noise sources and thermal response of SiGe/Si multilayer structures. Temperature coefficient of resistance (TCR) and noise voltage have been measured for different detector prototypes in terms of pixel size and multilayer designs. The performance of such structures was studied and optimized as a function of quantum well and Si barrier thickness (or dot size), number of periods in the SiGe/Si stack, Ge content and contact resistance. Both electrical and thermal responses of such detectors were sensitive to the quality of the epitaxial layers which was evaluated by the interfacial roughness and strain amount. The strain in SiGe material was carefully controlled in the meta–stable region by implementingivcarbon in multi quantum wells (MQWs) of SiGe(C)/Si(C). A state of the art thermistor material with TCR of 4.5 %/K for 100×100 μm2 pixel area and low noise constant (K1/f) value of 4.4×10-15 is presented. The outstanding performance of these devices is due to Ni silicide contacts, smooth interfaces, and high quality of multi quantum wells (MQWs) containing high Ge content.The novel idea of generating local strain using Ge multi quantum dots structures has also been studied. Ge dots were deposited at different growth temperatures in order to tune the intermixing of Si into Ge. The structures demonstrated a noise constant of 2×10-9 and TCR of 3.44%/K for pixel area of 70×70 μm2. These structures displayed an improvement in the TCR value compared to quantum well structures; however, strain relaxation and unevenness of the multi layer structures caused low signal–to–noise ratio. In this thesis, the physical importance of different design parameters of IR detectors has been quantified by using a statistical analysis. The factorial method has been applied to evaluate design parameters for IR detection improvements. Among design parameters, increasing the Ge content of SiGe quantum wells has the most significant effect on the measured TCR value.<br>QC 20110405

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GONCALVES, JOSEMARY A. C. "Medidas de correlacao angular direcional gama-gama para transicoes no sup(135)Xe." reponame:Repositório Institucional do IPEN, 1989. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10217.

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NUNES, BEATRIZ G. "Determinação exerimental de razões espectrais e do espectro de energia dos nêutrons no combustível do reator nuclear IPEN/MB-01." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10069.

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TAKEDA, MAURO N. "Determinacao da correcao para o efeito de soma em cascata para espectrometros de HPGe pelo metodo de Monte Carlo." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10916.

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GENEZINI, FREDERICO A. "Estudo do decaimento beta menos dos nucleos sup101Mo e sup101Tc." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10784.

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Martins, Fernando Prat Gonçalves. "Medida do espectro de energia dos nêutrons no núcleo do Reator IPEN/MB-01." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-14052012-110606/.

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Este trabalho apresenta a medida do espectro de energia dos nêutrons no núcleo do Reator IPEN/MB-01. Para tal, foram inseridos detectores de ativação na forma de diminutas folhas metálicas no núcleo do reator, na região moderadora, utilizando um dispositivo articulado que permite que as folhas fiquem posicionadas na posição central do núcleo do reator, garantindo que todas as folhas sejam irradiadas na mesma posição. Os detectores de ativação foram selecionados de forma a cobrir grande parte do espectro de energia dos nêutrons no Reator, para tanto foram utilizadas folhas de Au197, Mg24, Ti48, In115, Sc45 entre outras. Após a irradiação os detectores de ativação foram submetidos a espectrometria gama num sistema de contagem de Germânio hiper-puro, o que possibilitou a obtenção da atividade de saturação por núcleo alvo, um dos principais dados de entrada do código computacional de desdobramento de espectro unfolding SANDBP, que através de um processo iterativo, ajusta o espectro que melhor se adequa ao conjunto de dados de entrada do código, composto principalmente pelas taxas de reação por núcleo alvo obtidas experimentalmente e um espectro inicial de entrada, neste caso obtido à nível celular pelo código Hammer-Technion para a célula representativa do núcleo do Reator, fornecendo assim a solução do espectro.<br>This work presents the neutron spectrum measurements in the Reactor IPEN/MB- 01 using very thin activation detectors in the metallic form, in reactor core, in moderator region. An articulated device allows that the foils are inserted in the central position of reactor core, ensuring that all the foils are irradiated in the same position. The activation detectors of different materials such Au197, Mg24, Ti48, In115, Sc45 and others, were selected to cover a large range of neutron spectrum. After the irradiation, the activation detectors were submitted to a spectrometry gamma by using a system of counting with high purity Germanium, to obtain the saturation activity per target nuclide. The saturation activity is one of the main data of input of unfolding code SANDBP, that through an iterative adjustment, modify the spectrum that better agree with the dataset of code input, composition mainly for measure reaction rate per target nuclide and a initial input spectrum, calculated for Hammer-Technion code, supplying a solution spectrum.

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COSTA, PRISCILA. "Desenvolvimento de uma metodologia para caracterização do filtro cuno do reator IEA-R1 utilizando o método de Monte Carlo." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23659.

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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-04-14T11:33:08Z No. of bitstreams: 0<br>Made available in DSpace on 2015-04-14T11:33:08Z (GMT). No. of bitstreams: 0<br>Dissertação (Mestrado em Tecnologia Nuclear)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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ZEITUNI, CARLOS A. "Espectrometria gama em elementos combustiveis tipo placa irradiados." reponame:Repositório Institucional do IPEN, 1998. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10689.

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CARDOSO, VANDERLEI. "Metodos de ajuste de curvas de eficiencia obtidas por meio de espectrometros de HPGe." reponame:Repositório Institucional do IPEN, 2002. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11015.

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AQUINO, REGINALDO R. de. "Avaliacao da radioatividade natural em areias das praias da Grande Vitoria, Espirito Santo." reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9612.

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Made available in DSpace on 2014-10-09T12:28:38Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T13:57:15Z (GMT). No. of bitstreams: 0<br>Dissertacao (Mestrado)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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COSTA, OSVALDO L. da. "Estudo e desenvolvimento de uma nova metodologia de produção de iodo-125 a partir de xenônio-124 pelo método de ativação neutrônica." reponame:Repositório Institucional do IPEN, 2015. http://repositorio.ipen.br:8080/xmlui/handle/123456789/25301.

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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-12-10T17:38:32Z No. of bitstreams: 0<br>Made available in DSpace on 2015-12-10T17:38:32Z (GMT). No. of bitstreams: 0<br>Tese (Doutorado em Tecnologia Nuclear)<br>IPEN/T<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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PURGATO, RAFAEL T. "Medida do buckling e da probabilidade de fuga de nêutrons do núcleo do reator IPEN/MB-01." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23276.

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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-01-19T10:26:11Z No. of bitstreams: 0<br>Made available in DSpace on 2015-01-19T10:26:11Z (GMT). No. of bitstreams: 0<br>Dissertação (Mestrado em Tecnologia Nuclear)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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MEDEIROS, ILCA M. M. A. "Espectroscopia gama no nucleo sup(149) Nd." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10961.

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Made available in DSpace on 2014-10-09T12:46:08Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T14:02:07Z (GMT). No. of bitstreams: 1 07612.pdf: 5577228 bytes, checksum: 86856f19b569f944e37500784558338a (MD5)<br>Dissertacao (Mestrado)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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LIMA, JOSENILSON B. DE. "Desenvolvimento de uma metodologia para a caracterização de tambores de rejeitos radioativos." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/27131.

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Submitted by Maria Eneide de Souza Araujo (mearaujo@ipen.br) on 2017-03-10T15:06:09Z No. of bitstreams: 1 23000.pdf: 2483857 bytes, checksum: ba54fa302ba8e46dabc056e73e8bd8ee (MD5)<br>Made available in DSpace on 2017-03-10T15:06:09Z (GMT). No. of bitstreams: 1 23000.pdf: 2483857 bytes, checksum: ba54fa302ba8e46dabc056e73e8bd8ee (MD5)<br>Rejeitos radioativos são gerados em todas as etapas do ciclo do combustível nuclear e em instituições que fazem uso de elementos radioativos. No Brasil, para que possam atender a legislação vigente, eles devem ser devidamente gerenciados e tratados. A caracterização é a etapa do gerenciamento de rejeitos radioativos que certifica e complementa as informações presentes no documento de identificação fornecido pelo gerador dos rejeitos radioativos. O objetivo desse trabalho foi desenvolver uma metodologia para caracterização de tambores de rejeitos radioativos. Neste trabalho foi utilizada a técnica de espectrometria gama associada ao método de Monte Carlo para obter e estabelecer uma relação entre as eficiências de contagens teóricas e experimentais para quatro tambores de calibração com densidades diferentes, preparados com nove tubos de PVC em seu interior. O detector de HPGe utilizado foi posicionado em três diferentes distâncias em relação a extremidade do tambor de calibração. A utilização do método de Monte Carlo mostrou-se adequado a metodologia proposta neste trabalho.<br>Dissertação (Mestrado em Tecnologia Nuclear)<br>IPEN/D<br>Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

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LACERDA, FLAVIO W. "Padronização de sup(68)Ga em sistema de coincidências 4pß-?" reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10211.

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Made available in DSpace on 2014-10-09T12:36:04Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T13:59:49Z (GMT). No. of bitstreams: 0<br>Dissertação (Mestrado)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Bruyneel, Bart [Verfasser]. "Characterization of segmented large volume, high purity Germanium detectors / vorgelegt von Bart Bruyneel." 2006. http://d-nb.info/981519466/34.

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Chen, Jing-Han, and 陳璟翰. "Background Studies and Understanding for High-Purity Germanium Detector at Kuo-Sheng Neutrino Laboratory." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/84818870922492230524.

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碩士<br>國立臺灣大學<br>天文物理研究所<br>104<br>To observe the neutrino-nucleus coherent scattering and dark matter searching, a detection system with ultra-low energy high purity germanium detector has been built up by TEXONO Collaboration in Kuo-Sheng Nuclear Power Plant. Due to the rarity and small recoil energy of these processes, understanding the background sources and their contribution to the energy spectrum are the key factors in this experiment. By using a data analysis toolkit called ROOT which was developed by CERN to reproduce the background, comparing to the experimental data, we can estimate the upper limit of Tritium beta decay activities in HPGe crystal. In data analysis, the p-type Germanium detector has a surface effect which will distort the energy deposit in the surface of Ge crystal, a charge collection efficiency function is to determine the energy loss because of the surface effect. By ROOT and a simulation toolkit GEANT4, we can try to find out the possible structure of charge collection efficiency in Ge surface.

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34

Barnabé, Heider Marik [Verfasser]. "Performance and stability tests of bare high purity germanium detectors in liquid argon for the GERDA experiment / presented by Marik Barnabé Heider." 2009. http://d-nb.info/99503785X/34.

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Hsi-Ming, Chang. "A Search for Axions at the Kuo-Sheng Nuclear Power Plant with a High-Purity Germanium Detector." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1206200618201200.

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Chang, Hsi-Ming, and 張曦明. "A Search for Axions at the Kuo-Sheng Nuclear Power Plant with a High-Purity Germanium Detector." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/47311153023296352795.

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碩士<br>國立臺灣大學<br>物理研究所<br>94<br>In order to solve the strong CP problem, a new neutral particle with spin-parity 0^{-}, the axion, was invented. The strong CP problem is perplexing because it will manifest itself as an enormous neutron electric dipole moment: ten orders of magnitude larger than the experimental constraint. Although, from the experimental point of view, axion remains undiscovered, there is still strong interest in axions while other solutions to strong CP problem are not explicitly better. For instance, axions and weakly interacting massive particles (WIMPs) are two leading candidates for dark matter in our universe. A search for axions in specific nuclear transitions was performed at the Kuo-Sheng Nuclear Power Plant. Because of the pseudoscalar nature of axions, they could be emitted by competing with photons via nuclear de-excitation in reactor. Similar to neutrinos, axions interact feebly with normal matter, which makes the detection of such particles difficult. A 1.06 kg high-purity germanium detector was placed 28 meters from reactor core to detect single photons produced by axion Primakoff and/or Compton conversions inside the detector. For axion-to-photon branching ratio as well as axion coupling constants, two model-independent limits have been derived at 90% confidence level. Although the g_arr limit is not as competitive as other experiments, our limit on g_aee is unique.

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Majorovits, Béla Alexander [Verfasser]. "High purity germanium detectors for the search of rare events : background discrimination and future prospects with the GENIUS project / presented by Béla Alexander Majorovits." 2000. http://d-nb.info/961763531/34.

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Heng-Ye, Liao. "A Search of Neutrino-Induced Nuclear Transitions in 73Ge at the Kuo-Sheng Nuclear Power Plant with a High-Purity Germanium Detector." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2007200604151300.

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(5929988), Shih-Chieh Liu. "Test of Decay Rate Parameter Variation due to Antineutrino Interactions." Thesis, 2019.

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High precision measurements of a weak interaction decay were conducted to search for possible variation of the decay rate parameter caused by an antineutrino flux. The experiment searched for variation of the <sup>54</sup>Mn electron capture decay rate parameter to a level of precision of 1 part in ∼10<sup>5</sup> by comparing the difference between the decay rate in the presence of an antineutrino flux ∼3×10<sup>12</sup> cm<sup>-2</sup>sec<sup>-1</sup> and no flux measurements. The experiment is located 6.5 meters from the reactor core of the High Flux Isotope Reactor (HFIR) in Oak Ridge National Laboratory. A measurement to this level of precision requires a detailed understanding of both systematic and statistical errors. Otherwise, systematic errors in the measurement may mimic fundamental interactions. <div><br></div><div>The gamma spectrum has been collected from the electron capture decay of <sup>54</sup>Mn. What differs in this experiment compared to previous experiments are, (1) a strong, uniform, highly controlled, and repeatable source of antineutrino flux, using a reactor, nearly 50 times higher than the solar neutrino flux on the Earth, (2) the variation of the antineutrino flux from HFIR is 600 times higher than the variation in the solar neutrino flux on the Earth, (3) the extensive use of neutron and gamma-ray shielding around the detectors, (4) a controlled environment for the detector including a fixed temperature, a nitrogen atmosphere, and stable power supplies, (5) the use of precision High Purity Germanium (HPGe) detectors and finally, (6) accurate time stamping of all experimental runs. By using accurate detector energy calibrations, electronic dead time corrections, background corrections, and pile-up corrections, the measured variation in the <sup>54</sup>Mn decay rate parameter is found to be δλ/λ=(0.034±1.38)×10<sup>-5</sup>. This measurement in the presence of the HFIR flux is equivalent to a cross-section of σ=(0.097±1.24)×10<sup>-25 </sup>cm<sup>2</sup>. These results are consistent with no measurable decay rate parameter variation due to an antineutrino flux, yielding a 68% confidence level upper limit sensitivity in δλ/λ <= 1.43×10<sup>-5</sup> or σ<=1.34×10<sup>-25 </sup>cm<sup>2</sup> in cross-section. The cross-section upper limit obtained in this null or no observable effect experiment is ∼10<sup>4</sup> times more sensitive than past experiments reporting positive results in <sup>54</sup>Mn.</div>

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Lu, Christopher Hing. "Determination of fission product yields of 235U using gamma ray spectroscopy." 2012. http://hdl.handle.net/2152/19716.

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It is important to have a method of experimentally calculating fission product yields. Statistical calculations and simulations produce very large uncertainties. Experimental calculations, depending on the methods used, tend to produce lower uncertainties. This work set up a method to calculate fission product yields using gamma ray spectroscopy. In order to produce a method that was theoretically sound, a simulation was set up using OrigenArp to calculate theoretical concentrations of fission products from the irradiation of natural uranium. From these concentrations, the fission product yields were calculated to verify that they would agree with expected values. Moving forward in the work, the total flux at the point of irradiation, in the pneumatic transfer system, was calculated and determined to be 3.9070E+11 ± 6.9570E+10 n/cm^2/s at 100 kW. Once the flux was calculated, the method for calculating fission product yields was implemented and yields were calculated for 10 fission products. The yields calculated were in very good agreement (within 10.04%) with expected values taken from the ENDF-349 library. This method has strong potential in nuclear forensics as it can provide a means for developing a library of experimentally-determined fission product yields, as well as rapid post-nuclear detonation analysis.<br>text

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