A5038443124- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Advanced Semiconductor Detectors and Materials
- Nuclear Physics and Applications
- Advanced X-ray and CT Imaging
- Gamma-ray bursts and supernovae
- Neutrino Physics Research
- Medical Imaging Techniques and Applications
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Quantum and electron transport phenomena
- Radiation Therapy and Dosimetry
- Semiconductor Quantum Structures and Devices
- Astrophysical Phenomena and Observations
- Electronic and Structural Properties of Oxides
- Physics of Superconductivity and Magnetism
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Surface and Thin Film Phenomena
- Ionosphere and magnetosphere dynamics
- Silicon and Solar Cell Technologies
- Geophysics and Gravity Measurements
- Semiconductor materials and devices
Universidad Católica Santo Domingo
2023
University of California, Berkeley
1999-2023
Berkeley College
2023
Lawrence Berkeley National Laboratory
2010-2022
National Tsing Hua University
2017
Institute of Physics, Academia Sinica
2017
Institut de Recherche en Astrophysique et Planétologie
2017
Lawrence Livermore National Laboratory
2009
Paul Scherrer Institute
2000-2006
University of California System
2006
The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-β decay in ^{76}Ge. Demonstrator comprises 44.1 kg (29.7 enriched ^{76}Ge) split between two modules contained a low background shield at the Sanford Underground Research Facility Lead, South Dakota. Here we present results from data taken during construction, commissioning, and start full operations. We achieve unprecedented energy resolution 2.5 keV FWHM Q_{ββ} very with no...
We present a theoretical analysis for system composed of two mesoscopic tunnel junctions coupled in series. show that the current-voltage characteristic this can be obtained analytically. The usefulness model is demonstrated through fit experimental data acquired with cryogenic (4.2 K) scanning tunneling microscope. A simple extension predicts additional structure characteristics when discrete middle electrode states are present.
The focus of this paper is to evaluate thick, 20×20×10 and 10×10×10mm3, cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THM). phenomenal spectral performance small size low concentration Te inclusions/precipitates these indicate that THM suitable for mass production CZT radiation detectors can be used in a variety applications. Our result also proves with careful material selection IR high-quality fabrication processes, theoretical energy...
The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer (SMEX) satellite mission in development with planned launch 2027. COSI wide-field gamma-ray telescope designed to survey the entire sky at 0.2-5 MeV. It provides imaging, spectroscopy, polarimetry of astrophysical sources, its germanium detectors provide excellent energy resolution for emission line measurements. Science goals include studies 0.511 MeV from antimatter annihilation Galaxy, mapping radioactive elements...
Over 25 1-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> CdZnTe crystals produced using the Traveling Heater Method at Redlen Technologies have been characterized. The charge carrier mobility and lifetime, transport uniformity of each crystal were measured alpha particles. Some made into coplanar-grid detectors their performance characterized 662 keV gamma rays. average electron mobility-lifetime product for these was found to be a...
Gamma-ray spectroscopy is a valuable tool of science and technology. Many applications for this are in need detector technology capable achieving excellent energy resolution efficient detection while operating at room temperature. Detectors based on the material cadmium zinc telluride (CdZnTe) could potentially meet if certain deficiencies addressed. The coplanar-grid as well other electron-only techniques effective overcoming some problems CdZnTe and, consequently, have led to gamma-ray...
We present a theoretical study of the current-voltage characteristic new transistor based upon ‘‘Coulomb blockade.’’ In mesoscopic (submicron) tunnel junctions flow current can be blocked by electrostatic charging energy single electron. The charge-effect is composed two connected in series with gate terminal capacitively coupled to interjunction region. Such device has been shown lead Coulomb staircase when voltage zero. Here we effect on through for various ranges junction parameters. made...
A long duration gamma-ray burst, GRB 160530A, was detected by the Compton Spectrometer and Imager (COSI) during 2016 COSI Super Pressure Balloon campaign. As a telescope, is inherently sensitive to polarization of sources in energy range 0.2-5.0 MeV. We measured 160530A using 1) standard method (SM) based on fitting distribution azimuthal scattering angles with modulation curve, 2) an unbinned, maximum likelihood (MLM). In both cases, level below $99\%$ confidence minimum detectable levels...
The Nuclear Compton Telescope (NCT) is a balloon-borne telescope designed for the study of astrophysical sources in soft gamma-ray regime (200 keV–20 MeV). NCT's 10 high-purity germanium crossed-strip detectors measure deposited energies and three-dimensional positions interactions sensitive volume, this information used to restrict initial photon circle on sky using scatter technique. Thus NCT able perform spectroscopy, imaging, polarization analysis sources. one next generation...
The Compton Spectrometer and Imager (COSI) is a balloon-borne, soft-gamma ray imager, spectrometer, polarimeter with sensitivity from 0.2 to 5 MeV. Utilizing compact telescope design twelve cross-strip, high-purity germanium detectors, COSI has three main science goals: study the 511 keV positron annihilation line Galactic plane, image diffuse emission stellar nuclear lines, perform polarization studies of gamma-ray bursts other extreme astrophysical environments. just completed successful...
The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer (SMEX) satellite mission in development with planned launch 2027. COSI wide-field gamma-ray telescope designed to survey the entire sky at 0.2-5 MeV. It provides imaging, spectroscopy, polarimetry of astrophysical sources, its germanium detectors provide excellent energy resolution for emission line measurements. Science goals include studies 0.511 MeV from antimatter annihilation Galaxy, mapping radioactive elements...
Electron radiation induced hydrocarbon contamination can be either a problem or useful tool in electron beam analyses and lithographies. We have used atomic force microscopy to study written structures. Contamination is shown not only arise from the primary but also energy scattered outside of direct impingement area. The size structures correlates well with that expected scattering theory. By varying geometry structures, rate at which dose deposited, nearby surface density, we show...
Coplanar-grid CdZnTe detectors have been under development for the past ten years as room-temperature gamma-ray spectrometers and are being produced use in a number of applications. Despite improvements detector active volume spectral response that achieved with coplanar-grid technique, full potential such is still far from realized. There exists material, device, electronics factors limit performance yield. Some major identified examined terms their origins magnitude effects on energy resolution.
The search for a semiconductor detector capable of room-temperature operation with similar performance to liquid- nitrogen-cooled Ge detectors has been going on several decades. main challenge is in achieving the very high degree spatial uniformity response that needed high-resolution gamma-ray detection. There exist two distinct paths one can take meet this goal. One path develop materials near-perfect charge transport properties Ge. This requires mobilities and lifetimes both electrons...
The spectral response of several crystals grown by the Traveling Heater Method (THM) were investigated. An energy resolution 0.98% for a Pseudo Frisch-Grid 4 times 9 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and 2.1% FWHM coplanar-grid size 11 5 measured using xmlns:xlink="http://www.w3.org/1999/xlink">137</sup> Cs-662 keV. In addition 4% at 122 keV has also been on 20 X monolithic pixellated devices. material shows great...
Neutrinoless double-beta decay searches play a major role in determining the nature of neutrinos, existence lepton violating process, and effective Majorana neutrino mass. The Collaboration proposes to assemble an array HPGe detectors search for neutrinoless Ge-76. Our proposed method uses well-established technique searching high purity Ge-diode radiation that both roles source detector. is augmented with recent improvements signal processing detector design, advances controlling intrinsic...