Download or read book A Multi Contact Low Capacitance HPGe Detector for High Rate Gamma Spectroscopy written by and published by . This book was released on 2014 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The detection, identification and non-destructive assay of special nuclear materials and nuclear fission by-products are critically important activities in support of nuclear non-proliferation programs. Both national and international nuclear safeguard agencies recognize that current accounting methods for spent nuclear fuel are inadequate from a safeguards perspective. Radiation detection and analysis by gamma-ray spectroscopy is a key tool in this field, but no instrument exists that can deliver the required performance (energy resolution and detection sensitivity) in the presence of very high background count rates encountered in the nuclear safeguards arena. The work of this project addresses this critical need by developing a unique gamma-ray detector based on high purity germanium that has the previously unachievable property of operating in the 1 million counts-per-second range while achieving state-of-the-art energy resolution necessary to identify and analyze the isotopes of interest. The technical approach was to design and fabricate a germanium detector with multiple segmented electrodes coupled to multi-channel high rate spectroscopy electronics. Dividing the germanium detector's signal electrode into smaller sections offers two advantages; firstly, the energy resolution of the detector is potentially improved, and secondly, the detector is able to operate at higher count rates. The design challenges included the following; determining the optimum electrode configuration to meet the stringent energy resolution and count rate requirements; determining the electronic noise (and therefore energy resolution) of the completed system after multiple signals are recombined; designing the germanium crystal housing and vacuum cryostat; and customizing electronics to perform the signal recombination function in real time. In this phase I work, commercial off-the-shelf electrostatic modeling software was used to develop the segmented germanium crystal geometry, which underwent several iterations before an optimal electrode configuration was found. The model was tested and validated against real-world measurements with existing germanium detectors. Extensive modeling of electronic noise was conducted using established formulae, and real-world measurements were performed on candidate front-end electronic components. This initial work proved the feasibility of the design with respect to expected high count rate and energy resolution performance. Phase I also delivered the mechanical design of the detector housing and vacuum cryostat to be built in Phase II. Finally, a Monte Carlo simulation was created to show the response of the complete design to a Cs-137 source. This development presents a significant advance for nuclear safeguards instrumentation with increased speed and accuracy of detection and identification of special nuclear materials. Other significant applications are foreseen for a gamma-ray detector that delivers high energy resolution (1keV FWHM noise) at high count rate (1 Mcps), especially in the areas of physics research and materials analysis.

Download or read book Fabrication Process Development for High Purity Germanium Radiation Detectors with Amorphous Semiconductor Contacts written by Quinn Looker and published by . This book was released on 2014 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-purity germanium (HPGe) radiation detectors are well established as a valuable tool in nuclear science, astrophysics, and nuclear security applications. HPGe detectors excel in gamma-ray spectroscopy, offering excellent energy resolution with large detector sizes for high radiation detection efficiency. Although a robust fabrication process has been developed, improvement is needed, especially in developing electrical contact and surface passivation technology for position-sensitive detectors. A systematic study is needed to understand how the detector fabrication process impacts detector performance and reliability. In order to provide position sensitivity, the electrical contacts are segmented to form multiple electrodes. This segmentation creates new challenges in the fabrication process and warrants consideration of additional detector effects related to the segmentation. A key area of development is the creation of the electrical contacts in a way that enables reliable operation, provides low electronic noise, and allows fine segmentation of electrodes, giving position sensitivity for radiation interactions in the detector. Amorphous semiconductor contacts have great potential to facilitate new HPGe detector designs by providing a thin, high-resistivity surface coating that is the basis for electrical contacts that block both electrons and holes and can easily be finely segmented. Additionally, amorphous semiconductor coatings form a suitable passivation layer to protect the HPGe crystal surface from contamination. This versatility allows a simple fabrication process for fully passivated, finely segmented detectors. However, the fabrication process for detectors with amorphous semiconductors is not as highly developed as for conventional technologies. The amorphous semiconductor layer properties can vary widely based on how they are created and these can translate into varying performance of HPGe detectors with these contacts. Some key challenges include minimizing charge injection leakage current, increasing the long-term stability of the contacts, and achieving good charge collection properties in segmented detectors. A systematic study of contact characteristics is presented where amorphous germanium (a-Ge) and amorphous silicon (a-Si) contacts are sputtered with varying sputter gas hydrogen content, sputter gas pressure, and amorphous film thickness. A set of about 45 detectors fabricated from 11 different crystal samples were analyzed for electron barrier height and effective Richardson constant. Most of these detectors were subjected to as many as 10 temperature cycles over a period of up to several months in order to assess their long-term stability. Additionally, 6 double-sided strip detectors were fabricated with a-Ge and a-Si contacts in order to study their inter-electrode charge collection properties. An attempt is made to relate fabrication process parameters such as hydrogen content, sputter pressure, and film thickness to changes observed in detector performance and assess the level of reproducibility using the current methods. Several important results and conclusions were found that enable more reliable and highly performing detectors with amorphous semiconductor contacts. Utilizing the new information should enable consistent production of finely segmented detectors with excellent energy resolution that can be operated reliably for a long period of time. The passivation process could impact planar detectors as well as other designs, such as the p-type point contact detector. It is demonstrated that the long-term stability of amorphous semiconductor contacts is primarily dependent on the time the detector is at room temperature rather than the number of temperature cycles. For a-Ge contacts, higher sputter pressure yields a more stable process that changes little with time, giving a reliable hole-blocking contact. The a-Si contacts form a good electron-blocking contact with decreasing leakage current over time. Both materials, when 7% hydrogen is included in the argon sputter gas, show acceptable levels of inter-electrode charge collection to be useful for strip electrode detectors.

Download or read book Characterization of Mechanically Cooled High Purity Germanium HPGe Detectors at Elevated Temperatures written by Joseph Benjamin McCabe and published by . This book was released on 2015 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: High resolution gamma spectroscopy is a tool used in nuclear security applications due to its achievable energy resolution and associated ability to identify special nuclear material. This identification ability is achieved by identifying the characteristic gamma-rays of a material. The challenges that have confronted industry concerning the use of hand-held high purity germanium (HPGe) in homeland security applications have centered on weight, geometry, and cool-down time. Typical liquid nitrogen cooled detectors ranging in size from 10% to 150% detectors will cool down sufficiently within 2-6 hours of filling. The cool-down time achieved in this research ranges from 45 min on the smallest detector to six hours on the largest 180 cm3 detector; which is consistent with typical hand held HPGe devices. The weight and package geometry for HPGe-based designs is driven by the need to cool the HPGe detector to cryogenic temperatures. This is due to small bandgap (~0.7 eV) of HPGe. Liquid nitrogen or mechanical cooling is required to achieve such temperatures. This dissertation presents work performed to characterize energy resolution performance as a function of temperature in a new mechanically cooled HPGe detector design based upon a split-Stirling cryocooler. This research also quantifies the microphonic noise contribution from this cryocooler. Measurements have been taken on detector sizes ranging from 6.75 cubic centimeters to 180 cubic centimeters. Focus has been placed on determining volume dependence on energy resolution at elevated temperatures. Microphonic noise contribution from the cooler has also been studied over the same temperature range. This energy resolution degradation was most pronounced at low temperatures (

Download or read book Handbook of Particle Detection and Imaging written by Claus Grupen and published by Springer Science & Business Media. This book was released on 2012-01-08 with total page 1251 pages. Available in PDF, EPUB and Kindle. Book excerpt: The handbook centers on detection techniques in the field of particle physics, medical imaging and related subjects. It is structured into three parts. The first one is dealing with basic ideas of particle detectors, followed by applications of these devices in high energy physics and other fields. In the last part the large field of medical imaging using similar detection techniques is described. The different chapters of the book are written by world experts in their field. Clear instructions on the detection techniques and principles in terms of relevant operation parameters for scientists and graduate students are given.Detailed tables and diagrams will make this a very useful handbook for the application of these techniques in many different fields like physics, medicine, biology and other areas of natural science.

Download or read book A Transportable High resolution Gamma ray Spectrometer and Analysis System Applicable to Mobile Autonomous Or Unattended Applications written by and published by . This book was released on 1995 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Safeguards Technology Program at the Lawrence Livermore National Laboratory is developing systems based on a compact electro-mechanically cooled high-purity germanium (HPGe) detector. This detector system broadens the practicality of performing high- resolution gamma-ray spectrometry in the field. Utilizing portable computers, multi-channel analyzers and software these systems greatly improve the ease of performing mobile high-resolution gamma-ray spectrometry. Using industrial computers, we can construct systems that will run autonomously for extended periods of time without operator input or maintenance. These systems can start or make decisions based on sensor inputs rather than operator interactions. Such systems can provide greater capability for wider domain of safeguards, treaty verification application, and other unattended, autonomous or in-situ applications.

Download or read book High resolution Gamma ray Detectors for Nuclear Spectroscopy written by Mark Forrest Cunningham and published by . This book was released on 2002 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation Detection for Nuclear Physics written by David Gareth Jenkins and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Radiation detection is key to experimental nuclear physics as well as underpinning a wide range of applications in nuclear decommissioning, homeland security and medical imaging. This book presents the state-of-the-art in radiation detection of light and heavy ions, beta particles, gamma rays and neutrons. The underpinning physics of different detector technologies is presented, and their performance is compared and contrasted. Detector technology likely to be encountered in contemporary international laboratories is also emphasized. There is a strong focus on experimental design and mapping detector technology to the needs of a particular measurement problem. This book will be invaluable to PhD students in experimental nuclear physics and nuclear technology, as well as undergraduate students encountering projects based on radiation detection for the first time. Part of IOP Series in Nuclear Spectroscopy and Nuclear Structure." -- Prové de l'editor.

Download or read book Complete System for Portable Gamma Spectroscopy written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The report described a system built around the Computing Gamma Spectrometer (PSA) LEA 74-008. The software primarily supports high-resolution gamma-ray spectroscopy using either a high-purity intrinsic germanium detector (HPGe) or a lithium-drifted germanium detector (Ge(Li)).

Download or read book IEEE Standard Test Procedures for Germanium Gamma ray Detectors written by and published by . This book was released on 1997 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Practical Gamma ray Spectrometry written by Gordon Gilmore and published by John Wiley & Sons. This book was released on 2024-11-25 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cutting-edge new edition of the classic introduction to radioactive measurement Gammy-Ray Spectrometry is a key technique in the study of radioactive decay. It measures the rate and extent of radioactivity from a variety of sources, both natural and artificial, including cosmic ray sources, nuclear reactors, high-energy physics experiments, and more. The resulting data can be essential to environmental monitoring and to a range of experimental sciences. For years, Practical Gamma-Ray Spectrometry has served as the classic introduction to this area for current or aspiring practitioners. A comprehensive but accessible treatment of the subject, with a thorough discussion of all major classes of detectors and their associated electronic systems, it contains everything a researcher needs to make optimal gamma-ray measurements. Now fully updated to reflect the latest technology and experimental data, it is a must-own for researchers looking to incorporate gamma-ray spectrometry into their scientific practice. Readers of the third edition of Practical Gamma-Ray Spectrometry will also find: Fault-finding guide for rapid and effective problem resolution Workshop-style approach emphasizing the fundamentals of laboratory practice New sections dealing with novel developments in nuclear structure research, measuring effects of pollution and climate change, new semiconductor materials, and more Practical Gamma-Ray Spectrometry is ideal for PhD students and practicing gamma-ray spectroscopists, including researchers working on radiation, energy and environmental monitoring professionals, and researchers working in physics, archaeometry, and related subjects.

Download or read book Verslag Rembrandt tentoonstelling written by and published by . This book was released on 1952 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Semiconductor Detector Systems written by Helmuth Spieler and published by OUP Oxford. This book was released on 2005-08-25 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor sensors patterned at the micron scale combined with custom-designed integrated circuits have revolutionized semiconductor radiation detector systems. Designs covering many square meters with millions of signal channels are now commonplace in high-energy physics and the technology is finding its way into many other fields, ranging from astrophysics to experiments at synchrotron light sources and medical imaging. This book is the first to present a comprehensive discussion of the many facets of highly integrated semiconductor detector systems, covering sensors, signal processing, transistors and circuits, low-noise electronics, and radiation effects. The diversity of design approaches is illustrated in a chapter describing systems in high-energy physics, astronomy, and astrophysics. Finally a chapter "Why things don't work" discusses common pitfalls. Profusely illustrated, this book provides a unique reference in a key area of modern science.

Download or read book Use of Gamma Radiation Techniques in Peaceful Applications written by Basim Almayahi and published by BoD – Books on Demand. This book was released on 2019-10-02 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with gamma radiation in many fields, which encompasses diverse factors that affect human and animal life inside an environment. These fields include nuclear and medical physics, industrial processes, environmental sciences, radiation biology, radiation chemistry, radiotherapy, agriculture and forestry, sterilization, the food industry, and so on. The book covers an overview of gamma background radiations and measurements, radioactive decay, radioecological applications in environmental gamma dosimetry, gamma-ray interaction, monocolor gamma, influence of gamma radiation on dynamical mechanical properties, influence of low-dose gamma irradiation treatments on microbial decontamination, gamma-ray ionization enhancement in tissues, gas-filled surge arresters, modeling plastic deformation located in irradiated materials, radiotherapy, application of radiation and genetic engineering techniques, and gamma-ray measurements using unmanned aerial systems. This book is expected to benefit undergraduate and postgraduate students, researchers, teachers, practitioners, policy makers, and every individual who has a concern for a healthy life.

Download or read book Simulation of Background Reduction and Compton Suppression in a Low background HPGe Spectrometer at a Surface Laboratory written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: High-purity germanium (HPGe) detectors are well suited to analyse the radioactivity of samples. In order to reduce the environmental background for an ultra-low background HPGe spectrometer, low-activity lead and oxygen free copper are installed outside the probe to shield from gamma radiation, with an outer plastic scintillator to veto cosmic rays, and an anti-Compton detector to improve the peak-to-Compton ratio. Using Geant4 tools and taking into account a detailed description of the detector, we optimize the sizes of these detectors to reach the design requirements. A set of experimental data from an existing HPGe spectrometer was used to compare with the simulation. For the future low-background HPGe detector simulation, considering different thicknesses of BGO crystals and anti-coincidence efficiency, the simulation results show that the optimal BGO thickness is 5.5 cm, and the peak-to-Compton ratio of 40 K is raised to 1000 when the anti-coincidence efficiency is 0.85. In the background simulation, 15 cm oxygen-free copper plus 10 cm lead can reduce the environmental gamma rays to 0.0024 cps/100 cm 3 Ge (50 keV-2.8 MeV), which is about 10 −5 of the environmental background.

Download or read book Germanium Based Technologies written by Cor Claeys and published by Elsevier. This book was released on 2011-07-28 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Germanium is a semiconductor material that formed the basis for the development of transistor technology. Although the breakthrough of planar technology and integrated circuits put silicon in the foreground, in recent years there has been a renewed interest in germanium, which has been triggered by its strong potential for deep submicron (sub 45 nm) technologies. Germanium-Based technologies: From Materials to Devices is the first book to provide a broad, in-depth coverage of the field, including recent advances in Ge-technology and the fundamentals in material science, device physics and semiconductor processing. The contributing authors are international experts with a world-wide recognition and involved in the leading research in the field. The book also covers applications and the use of Ge for optoelectronics, detectors and solar cells. An ideal reference work for students and scientists working in the field of physics of semiconductor devices and materials, as well as for engineers in research centres and industry. Both the newcomer and the expert should benefit from this unique book. - State-of-the-art information available for the first time as an all-in-source - Extensive reference list making it an indispensable reference book - Broad coverage from fundamental aspects up to industrial applications

Download or read book Measurement and Detection of Radiation written by Nicholas Tsoulfanidis and published by Chem/Mats-Sci/E. This book was released on 1983 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamentals of nuclear radiation counting for undergraduate and graduate students in nuclear science, engineering, nuclear medicine, and health physics, and for laboratory engineers, scientists, and technicians. Covers statistical errors, different types of radiation detectors, relative and absolute measurements, spectroscopy, analyzing experimental data, activation analysis, and health physics. Annotation copyright by Book News, Inc., Portland, OR

Download or read book GRABGAM Analysis of Ultra Low Level HPGe Gamma Spectra written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The GRABGAM code has been used successfully for ultra-low level HPGe gamma spectrometry analysis since its development in 1985 at Savannah River Technology Center (SRTC). Although numerous gamma analysis codes existed at that time, reviews of institutional and commercial codes indicated that none addressed all features that were desired by SRTC. Furthermore, it was recognized that development of an in-house code would better facilitate future evolution of the code to address SRTC needs based on experience with low-level spectra. GRABGAM derives its name from Gamma Ray Analysis BASIC Generated At MCA/PC.