A5025443069- Advanced Semiconductor Detectors and Materials
- Calibration and Measurement Techniques
- Superconducting and THz Device Technology
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- CCD and CMOS Imaging Sensors
- Planetary Science and Exploration
- Semiconductor Quantum Structures and Devices
- Stellar, planetary, and galactic studies
- Silicon and Solar Cell Technologies
- Infrared Target Detection Methodologies
- Space Exploration and Technology
- Spacecraft and Cryogenic Technologies
- Semiconductor materials and interfaces
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Ion-surface interactions and analysis
- Nuclear Physics and Applications
- Spectroscopy and Laser Applications
- Spacecraft Design and Technology
- Electron and X-Ray Spectroscopy Techniques
- Silicon Nanostructures and Photoluminescence
- Photonic and Optical Devices
- Astrophysics and Star Formation Studies
- Advanced Chemical Physics Studies
Ames Research Center
2008-2021
Engineering Systems (United States)
2014-2016
Orion Corporation (United Kingdom)
1995
University of Saskatchewan
1993
Lund University
1989
Lawrence Berkeley National Laboratory
1981-1988
University of California, Berkeley
1980-1987
The Infrared Array Camera (IRAC) is one of three focal plane instruments in the Spitzer Space Telescope. IRAC a four-channel camera that obtains simultaneous broad-band images at 3.6, 4.5, 5.8, and 8.0 microns. Two nearly adjacent 5.2x5.2 arcmin fields view are viewed by four channels pairs (3.6 5.8 microns; 4.5 8 microns). All detector arrays 256x256 pixels size, with two shorter wavelength using InSb longer Si:As IBC detectors. powerful survey instrument because its high sensitivity, large...
The Infrared Array Camera (IRAC) is one of three focal plane instruments on board the Spitzer Space Telescope. IRAC a four-channel camera that obtains simultaneous broad-band images at 3.6, 4.5, 5.8, and 8.0 μm in two nearly adjacent fields view. We summarize here in-flight scientific, technical, operational performance IRAC.
In germanium, an interstitial hydrogen atom may bind at a substitutional of carbon, silicon, beryllium, or zinc to form shallow, monovalent acceptor complex. Photothermal ionization spectroscopy under uniaxial stress reveals that the complexes A(H,C), A(H,Si), A(Be,H), and A(Zn,H) have trigonal (${C}_{3v}$) symmetry. Each has two (1s)-like levels which shift, but do not split, stress. fourfold basis for ${\ensuremath{\Gamma}}_{8}$(${T}_{d}$) level, simultaneous diagonalization perturbations...
Using 14C-spiked pyrolytic graphite-coated quartz crucibles for the growth of nine ultra-pure germanium single crystals, we have determined carbon content and distribution in these crystals. autoradiography, observe a rapidly decreasing cluster concentration successively grown Nuclear radiation detectors made from crystals measure betas internally decaying 14C nuclei with close to 100% efficiency. An average value total [14C+12C] is ~2×1014cm-3, substantially larger than expected earlier...
The Echelon-cross-echelle spectrograph (EXES) is a high spectral resolution, mid-infrared designed for and operated on the Stratospheric Observatory Infrared Astronomy (SOFIA). EXES has multiple operational modes, but optimized resolution. heart of instrument one meter long, diamond-machined echelon grating. also uses 1024 2 Si:As detector low-background flux. We will discuss design, operation performance EXES.
This paper presents comparisons between wind measurements in the mesosphere and lower thermosphere by medium‐frequency (MF) radars high‐resolution Doppler imager onboard Upper Atmosphere Research Satellite (UARS). Because of distinctive observational patterns, time space averaging, data processing algorithms, satellites observe atmosphere from their own perspectives. thermal tides are an important part dynamics these regions atmosphere, tidal determinations both techniques were given...
The James Webb Space Telescope (JWST) is the successor to Hubble Telescope. JWST will be an infrared-optimized telescope, with approximately 6.5 m diameter primary mirror, that located at Sun-Earth L2 Lagrange point. Three of JWST’s four science instruments use Teledyne HgCdTe HAWAII-2RG (H2RG) near infrared detector arrays. During 2010, Project noticed a few its 5 μm cutoff H2RG detectors were degrading during room temperature storage, and NASA chartered “Detector Degradation Failure Review...
A double acceptor binding three holes has been observed for the first time with photoconductive far-infrared spectroscopy in beryllium-doped germanium single crystals. This new center, ${\mathrm{Be}}^{+}$, a hole energy of \ensuremath{\sim}5 meV and is only present when free are generated by ionization either neutral shallow acceptors or Be acceptors. The ${\mathrm{Be}}^{+}$ center thermally ionizes above 4 K. It disappears at uniaxial stress \ensuremath{\gtrsim}${10}^{9}$ dyn...
The Mid-Infrared Instrument (MIRI) is a 5 to 28 micron imager and spectrometer that slated fly aboard the JWST in 2013. Each of flight arrays 1024×1024 pixel Si:As impurity band conductor detector array, developed by Raytheon Vision Systems. JPL, conjunction with MIRI science team, has selected three along their spares. We briefly summarize development these devices, then describe measured performance supplemental data from sister flight-like parts.
HgCdTe detector arrays with a cutoff wavelength of ~10 ${\mu}$m intended for the NEOCam space mission were subjected to proton beam irradiation at University California Davis Crocker Nuclear Laboratory. Three tested - one 800 $\mu$m substrate intact, 30 substrate, and completely substrate-removed. The CdZnTe on which is grown, has been shown produce luminescence in shorter wave that causes elevated signal non-hit pixels when irradiation. This testing was conducted ascertain whether or not...
We examine cosmic ray rejection methodology on data collected from InSb and Si:As detectors. The application of an Up-the-Ramp sampling technique with identification mitigation is the focus this study. This valuable for space-based observatories which are exposed to high-radiation environments. validate approach radiation-test sets detectors were generated SIRTF. method studied in paper over 99.9% effective at removing rays preserves structure photometric quality image well within measurement error.
The HIgh-Resolution Mid-infrarEd Spectrometer (HIRMES) is the 3rd Generation Instrument for Stratospheric Observatory For Infrared Astronomy (SOFIA), currently in development at NASA Goddard Space Flight Center (GSFC), and due commissioning 2019. By combining direct-detection Transition Edge Sensor (TES) bolometer arrays, grating-dispersive spectroscopy, a host of Fabry-Perot tunable filters, HIRMES will provide ability high resolution ([Formula: see text]), mid-resolution low-resolution...
Transit spectroscopy is the most promising path toward characterizing nearby terrestrial planets at mid-infrared wavelengths in next 20 years. The Spitzer Space telescope has achieved moderately good photometric precision observations of transiting planets, but intrinsic stability mid-IR detectors themselves not been reported scientific or technical literature. Here, we evaluated a JWST MIRI prototype Si:As impurity band conduction detector, using time-series data taken under flood...
The Infrared Array Camera (IRAC) on Spitzer Space Telescope includes four Raytheon Vision Systems focal plane arrays, two with InSb detectors, and Si:As detectors. A brief comparison of pre- flight laboratory results vs. in-flight performance is given, including quantum efficiency noise, as well a discussion irregular effects, such residual image performance, "first frame effect", "banding", "column pull-down" multiplexer bleed. Anomalies not encountered in pre-flight testing, post-flight...
Raytheon/SBRC has demonstrated high quality Si:As IBC IR FPAs for both ground-based and space-based Mid-IR astronomy applications. These arrays offer in-band quantum efficiencies of approximately 50 percent over a wavelength range from 6 micrometers to 26 usable responses 2 28 . For background, applications the readout input circuit is direct injection (DI) FET, while low source follower per detector (SFD) used. The SFD offers extremely noise power dissipation, implemented in very small unit...
A recently proposed topological theory of strong interactions is extended to electromagnetism. This extension constructed so that, for reactions involving only leptons and photons, the expansion coincides with usual perturbation QED. The lowest term in corresponds pointlike elementary hadrons (as well as leptons); hadronic structure appears nonleading terms. natural explanation emerges quantization electric charge observed charges hadrons. Fractional nowhere appear even though there a notion...
Two Medium Frequency radars have been developed 500 km from the Saskatoon MF Radar (52.2N, 107.1W) to form a triangle within Canadian Prairies. The western system is at Sylvan Lake (52.4N, 114.1W) in lee of Rockies and southern Robsart (49.2N, 109.3W). In this preliminary assessment winds data, daily mean solar tides (24‐, 12‐hour) are shown be very similar, with short‐term variations several days being seen all three radars. This shows that such short term changes larger scale than km....
As the logical extension of 20-year mission Hubble Space Telescope, NASA plans to launch James Webb Telescope (JWST, formerly NGST) near end this decade. Hubble's scientific and technological successor, equipped with a 6-meter-class deployable mirror, JWST will allow observations very early universe initial formation galaxies at levels not achievable today. JWST's unprecedented sensitivity cannot be utilized without new class IR focal plane arrays whose performance matches that telescope. In...
We present measurements of proton-induced single event transients in ultra-low noise HgCdTe IR detector arrays being developed for space-based astronomy and compare to modeling results.