Download or read book Position Sensitive Proximity Charge Sensing Readout of HPGe Detectors written by Anders Peterson Priest and published by . This book was released on 2016 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrode segmentation is a necessity to achieve position sensitivity in semicon- ductor radiation detectors. Traditional segmentation requires decreasing electrode sizes while increasing channel numbers to achieve very fine position resolution. These electrodes can be complicated to fabricate, and many electrodes with individual electronic channels are required to instrument large detector areas. To simplify the fabrication process, we have moved the readout electrodes onto a printed cir- cuit board that is positioned above the ionization type detection material. In this scheme, charge from radiation interactions will be shared amongst several electrodes, allowing for position interpolation. Because events can be reconstructed in between electrodes, fewer electrodes are needed to instrument large detector areas. The prox- imity charge sensing method of readout promises to simplify detector fabrication while maintaining the position resolution that is required by fields such as home- land security, astrophysics, environmental remediation, nuclear physics, and medical imaging. We performed scanning measurements on a proof of principle detector that we fabricated at Lawrence Berkeley National Laboratory (LBNL). These measurements showed that position resolution much finer than the strip pitch was achievable using the proximity charge readout method. We performed analytic calculations and Monte Carlo modeling to optimize the readout electrode geometry for a larger detector to test the limits of this technology. We achieved an average position resolution of 288 [mu]m with eight proximity electrodes at a 5 mm pitch and 1 mm strip width, set 100 [mu]m away from the detector surface by a Kapton spacer. To achieve this resolution using standard technologies, 300 [mu]m pitch strips are necessary, and would require 100 channels to instrument the same area. Through our optimization calculations, we found that there is a trade-off between position resolution and energy resolution,2 and this system provided comparatively poor energy resolution by HPGe standards, with 4.7 keV FWHM at 59.5 keV. With another electrode geometry, we were able to achieve 2.9 keV FWHM at 59.5 keV. This dissertation describes the work we completed to achieve these results.
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 Charge Dividing Mechanism in Position Sensitive Detectors written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proximity Charge Sensing for Semiconductor Detectors written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A non-contact charge sensor includes a semiconductor detector having a first surface and an opposing second surface. The detector includes a high resistivity electrode layer on the first surface and a low resistivity electrode on the high resistivity electrode layer. A portion of the low resistivity first surface electrode is deleted to expose the high resistivity electrode layer in a portion of the area. A low resistivity electrode layer is disposed on the second surface of the semiconductor detector. A voltage applied between the first surface low resistivity electrode and the second surface low resistivity electrode causes a free charge to drift toward the first or second surface according to a polarity of the free charge and the voltage. A charge sensitive preamplifier coupled to a non-contact electrode disposed at a distance from the exposed high resistivity electrode layer outputs a signal in response to movement of free charge within the detector.
Download or read book Charge Collection in Silicon Strip Detectors written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of position sensitive silicon detectors as very high resolution tracking devices in high energy physics experiments has been a subject of intense development over the past few years. Typical applications call for the detection of minimum ionizing particles with position measurement accuracy of 10 .mu.m in each detector plane. The most straightforward detector geometry is that in which one of the collecting electrodes is subdivided into closely spaced strips, giving a high degree of segmentation in one coordinate. Each strip may be read out as a separate detection element, or, alternatively, resistive and/or capacitive coupling between adjacent strips may be exploited to interpolate the position via charge division measrurements. With readout techniques that couple several strips, the numer of readout channels can, in principle, be reduced by large factors without sacrificing the intrinsic position accuracy. The testing of individual strip properties and charge division between strips has been carried out with minimum ionizing particles or beams for the most part except in one case which used alphs particless scans. This paper describes the use of a highly collimated MeV proton beam for studies of the position sensing properties of representative one dimensional strip detectors.
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 Position Resolution Studies with MSU 32 Fold Segmented HPGe Detector written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present position sensitivity measurements obtained with one of the 32-fold segmented HPGe detectors from Michigan State University. These measurements were performed with a collimated beam of 137Cs gamma rays scattered by 90 degrees. This deposits 374 keV at a given location inside the crystal. A position resolution can be determined over many events by examining the digitally recorded pulse shapes on the 32 electrical contacts. If position resolution is adequate, gamma ray Compton camera imaging may be possible.
Download or read book Particle Detectors written by Hermann Kolanoski and published by Oxford University Press. This book was released on 2020-06-30 with total page 949 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the fundamentals of particle detectors as well as their applications. Detector development is an important part of nuclear, particle and astroparticle physics, and through its applications in radiation imaging, it paves the way for advancements in the biomedical and materials sciences. Knowledge in detector physics is one of the required skills of an experimental physicist in these fields. The breadth of knowledge required for detector development comprises many areas of physics and technology, starting from interactions of particles with matter, gas- and solid-state physics, over charge transport and signal development, to elements of microelectronics. The book's aim is to describe the fundamentals of detectors and their different variants and implementations as clearly as possible and as deeply as needed for a thorough understanding. While this comprehensive opus contains all the materials taught in experimental particle physics lectures or modules addressing detector physics at the Master's level, it also goes well beyond these basic requirements. This is an essential text for students who want to deepen their knowledge in this field. It is also a highly useful guide for lecturers and scientists looking for a starting point for detector development work.
Download or read book Environmental Health Perspectives written by and published by . This book was released on 1993 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation and Human Health written by Michael R. Quastel and published by . This book was released on 1997 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Principles of Radiation Interaction in Matter and Detection written by Claude Leroy and published by World Scientific. This book was released on 2009 with total page 951 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, like its first edition, addresses the fundamental principles of interaction between radiation and matter and the principle of particle detectors in a wide scope of fields, from low to high energy, including space physics and the medical environment. It provides abundant information about the processes of electromagnetic and hadronic energy deposition in matter, detecting systems, and performance and optimization of detectors. In this second edition, new sections dedicated to the following topics are included: space and high-energy physics radiation environment, non-ionizing energy loss (NIEL), displacement damage in silicon devices and detectors, single event effects, detection of slow and fast neutrons with silicon detectors, solar cells, pixel detectors, and additional material for dark matter detectors. This book will benefit graduate students and final-year undergraduates as a reference and supplement for courses in particle, astroparticle, and space physics and instrumentation. A part of it is directed toward courses in medical physics. The book can also be used by researchers in experimental particle physics at low, medium, and high energy who are dealing with instrumentation.
Download or read book Remote Compositional Analysis written by Janice L. Bishop and published by Cambridge University Press. This book was released on 2019-11-28 with total page 655 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive overview of the spectroscopic, mineralogical, and geochemical techniques used in planetary remote sensing.
Download or read book Passive Nondestructive Assay of Nuclear Materials written by Doug Reilly and published by . This book was released on 1991 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conduction in Non Crystalline Materials written by Sir Nevill Mott and published by Clarendon Press. This book was released on 1993-05-20 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition deals in an elementary way with electrons in non-crystalline systems. It reflects advances in the theory of interactions in non-crystalline systems, provides a more detailed discussion of the "minimum metallic conductivity", and addresses the relevance of disorder in the new high-temperature semiconductors.
Download or read book Astroparticle Particle and Space Physics Detectors and Medical Physics Applications written by Michele Barone and published by World Scientific. This book was released on 2006 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exploration of the subnuclear world is done through increasingly complex experiments covering a wide range of energies and in a large variety of environments ? from particle accelerators, underground detectors to satellites and space laboratories. For these research programs to succeed, novel techniques, new materials and new instrumentation need to be used in detectors, often on a large scale. Hence, particle physics is at the forefront of technological advancement and leads to numerous applications. Among these, medical applications have a particular importance due to the health and social benefits they bring. This volume reviews the advances made in all technological aspects of current experiments in the field.
Download or read book Radiation Detection and Measurement written by Glenn F. Knoll and published by . This book was released on 1989 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition of the methods and instrumentation used in the detection of ionizing radiation has been revised and updated to reflect recent advances. It covers modern engineering practice, provides useful design information and contains an up-to-date review of the literature.
