A5065407193- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Advanced Semiconductor Detectors and Materials
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- CCD and CMOS Imaging Sensors
- Semiconductor materials and interfaces
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Advancements in Semiconductor Devices and Circuit Design
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Radiation Effects in Electronics
- Calibration and Measurement Techniques
- Solar and Space Plasma Dynamics
- Dark Matter and Cosmic Phenomena
- Planetary Science and Exploration
- Nuclear and radioactivity studies
- Spacecraft and Cryogenic Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Semiconductor Quantum Structures and Devices
- VLSI and Analog Circuit Testing
- Graphite, nuclear technology, radiation studies
- Thin-Film Transistor Technologies
Public Health Dayton & Montgomery County
2014-2021
PHDS (United States)
2014
Lawrence Livermore National Laboratory
2002-2007
Lawrence Berkeley National Laboratory
1999-2005
Lawrence Livermore National Security
2004
Indiana University Bloomington
1995-2002
Indiana University
1996
We present an initial evaluation of a mechanically cooled, high-purity germanium double-sided strip detector as potential gamma camera for small-animal SPECT. It is 90 mm in diameter and 10 thick with two sets 16 orthogonal strips that have 4.5 width 5 pitch. found energy resolution 0.96% at 140 keV, intrinsic efficiency 43.3% 122 keV FWHM spatial approximately 1.5 mm. demonstrated depth-of-interaction estimation capability through comparison pinhole acquisitions point source on off axes....
We describe a coded-aperture-based gamma-ray imager that uses unique hybrid germanium detector system. A planar, strip detector, 11 mm thick, is followed by coaxial detector. The 19/spl times/19 (2-mm pitch) used to determine the location and energy of low-energy events. high-energy events determined from Compton scatter in planar sum energies. With this geometry, we obtain useful photopeak quantum efficiency position-sensitive mode out 500 keV with times/17 URA coded aperture spectrally...
A technique has been implemented for improving the 3-D position resolution in a germanium strip detector. By using signals induced on multiple electrodes, of drifting charges can be interpolated to smaller than width strips. Interpolation allows desired achieved with fewest number electronic channels. Applications include portable and space-based instruments where power, cooling, mass are at premium. Measurements were made fully instrumented 19/spl times/19 planar This system is used as...
We have investigated the effects of charge sharing and loss in gap between strips a prototype 19 /spl times/ germanium strip detector. Our measurements indicate some for events occurring strips, find that this "dead" region where is lost (which leads to an underestimated incident photon energy) narrower than physical width, confined small below surface. This illustrated by observing coincidence spectra nearest neighbor as function energy (and therefore interaction depth), confirmed with...
Recent developments of large-area Si(Li) orthogonal-strip detectors have revealed their capability for applications in Compton-effect-based instruments. Some inherent advantages silicon such as the dominance Compton scattering photon interactions and operation at room or somewhat lower temperature combined with availability large-volume could stimulate development powerful Several diodes 10 mm thickness a diameter 102 were fabricated. Two thick cut to form 74 mm/spl times/74 square slightly...
We have developed germanium detector technologies for use in the Nuclear Compton Telescope (NCT) - a balloon-borne soft γ-ray (0.2-10 MeV) telescope to study astrophysical sources of nuclear line emission and polarization. The heart NCT is an array twelve large volume cross strip detectors, designed provide 3-D positions each photon interaction with ~1mm resolution while maintaining high spectral germanium. Here we discuss detailed performance our prototype 19x19 detector, including...
A novel, fully reconfigurable liquid collimator device for γ-ray and X-ray imaging was built tested as a coded aperture. The contained 10 × grid of 5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> chambers, each cm long. chambers were either grilled with an attenuating liquid, absorbing photons, or evacuated the allowing photons to pass. As pattern “on” “off” manipulated, different, semi-independent views source found. random mask...
Many future space missions will use cadmium zinc telluride (CdZnTe) gamma-ray detectors because their operation at room temperature makes compact, lightweight detector systems possible. Even though instruments for using CdZnTe have already been built, the effect of high- energy particle environment on these has not measured. To determine energetic charged particles detectors, we bombarded several with 199 MeV protons Indianan University Cyclotron Facility. Planar area 1 cm<SUP>2</SUP> and...
Our collaboration is developing a 2-detector prototype high resolution Compton telescope utilizing 3D imaging germanium detectors (GeDs) for test balloon flight in Spring 2003. This instrument full 12-GeD instrument, the Nuclear Telescope. NCT balloon-borne soft gamma-ray (0.2-15 MeV) designed to study astrophysical sources of nuclear line emission and polarization. The program develop technologies analysis techniques crucial Advanced Telescope, while studying radiation with very spectral...
A gamma-ray spectrometer (GRS) has been built and delivered to the MESSENGER spacecraft which launched on August 3, 2004, from Cape Canaveral, Florida. The GRS, a part of seven scientific instruments board MESSENGER, is based coaxial high-purity germanium detector. Gamma-ray detectors have advantage providing excellent energy resolution, critical achieving science goals mission. However, disadvantage that it must operated at cryogenic temperatures (typically /spl sim/80 K). This requirement...
A coded aperture, germanium‐detector based gamma‐ray imaging system has been designed, fabricated, and tested. The detector, cryostat, signal processing electronics are discussed in this paper. latest version orthogonal strip planar detector is 11‐millimeters thick, having 38×38 strips of 2‐millimeter pitch. was fabricated using amorphous germanium contacts. on each face the lie a chorded‐circular pattern to more efficiently utilize area 10‐cm diameter crystal. held mount that allows...
A germanium based gamma ray imager with 3D position sensitivity is being developed. The will detect rays in the range of /spl sim/10 keV to 1.5 MeV and locate their interactions within 2 mm X, Y Z. instrument segmented into 39 orthogonal strips both X directions a pitch. Each channel separately instrumented miniature low-noise charge-sensitive preamplifier followed by shaping timing electronics. Germanium imagers 2-D have recently been developed fully our group. current adds capability for...