Download or read book Amorphous Germanium as an Electron Or Hole Blocking Contact on High purity Germanium Detectors written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were performed in an attempt to make thin n contacts on high-purity germanium by the solid phase1/ epitaxial regrowth of arsenic doped amorphous germanium. After cleaning the crystal surface with argon sputtering and trying many combinations of layers, it was not found possible to induce recrystallization below 400°C. However, it was found that simple thermally evaporated amorphous Ge made fairly good electron or hole blocking contacts. Excellent spectrometers have been made with amorphous Ge replacing the n/sup +/ contact. As presently produced, the amorphous Ge contact diodes show a large variation in high-voltage leakage current.

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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1977 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1977 with total page 1104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1977 with total page 1682 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1977 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1978 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.

Download or read book INIS Atomindex written by and published by . This book was released on 1984 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of X ray and Gamma ray Astrophysics written by Cosimo Bambi and published by Springer Nature. This book was released on with total page 5912 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hard X ray Gamma ray and Neutron Detector Physics written by and published by . This book was released on 2000 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Segmentation of the Outer Contact on P Type Coaxial Germanium Detectors written by Richard H. Pehl and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Germanium detector arrays are needed for low-level counting facilities. The practical applications of such user facilities include characterization of low-level radioactive samples. In addition, the same detector arrays can also perform important fundamental physics measurements including the search for rare events like neutrino-less double-beta decay. Coaxial germanium detectors having segmented outer contacts will provide the next level of sensitivity improvement in low background measurements. The segmented outer detector contact allows performance of advanced pulse shape analysis measurements that provide additional background reduction. Currently, n-type (reverse electrode) germanium coaxial detectors are used whenever a segmented coaxial detector is needed because the outer boron (electron barrier) contact is thin and can be segmented. Coaxial detectors fabricated from p-type germanium cost less, have better resolution, and are larger than n-type coaxial detectors. However, it is difficult to reliably segment p-type coaxial detectors because thick ({approx}1 mm) lithium-diffused (hole barrier) contacts are the standard outside contact for p-type coaxial detectors. During this Phase 1 Small Business Innovation Research (SBIR) we have researched the possibility of using amorphous germanium contacts as a thin outer contact of p-type coaxial detectors that can be segmented. We have developed amorphous germanium contacts that provide a very high hole barrier on small planar detectors. These easily segmented amorphous germanium contacts have been demonstrated to withstand several thousand volts/cm electric fields with no measurable leakage current (

Download or read book Index to IEEE Publications written by Institute of Electrical and Electronics Engineers and published by . This book was released on 1978 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues for 1973- cover the entire IEEE technical literature.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1977 with total page 1270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1992 with total page 1812 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Applied Physics Applied Physics Letters written by Nichigai Asoshiētsu and published by . This book was released on 1974 with total page 1272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Tunneling Into Amorphous Germanium written by James W. Osmun and published by . This book was released on 1975 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of the RF Sputtered Blocking Contacts on High Purity Germanium Detectors written by Richard Ira Stamm and published by . This book was released on 1979 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: