排序方式: 共有42条查询结果,搜索用时 15 毫秒
1.
Johannes Staguhn Dominic Benford Eli Dwek Gene Hilton Dale Fixsen Kent Irwin Christine Jhabvala Attila Kovacs Samuel Leclercq Stephen Maher Tim Miller S. Harvey Moseley Elmer Sharp Edward Wollack 《Journal of Low Temperature Physics》2014,176(5-6):829-834
We present the main design features for the GISMO-2 bolometer camera, which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISMO-2 will operate simultaneously in the 1 and 2 mm atmospherical windows. The 1 mm channel uses a \(32 \times 40\) TES-based backshort under grid (BUG) bolometer array, the 2 mm channel operates with a \(16 \times 16\) BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISMO-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera, which is successfully operating at the 30 m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals. 相似文献
2.
Rinehart SA Benford DJ Cataldo G Dwek E Henry R Kinzer RE Nuth J Silverberg R Wheeler C Wollack E 《Applied optics》2011,50(21):4115-4123
Dust is found throughout the universe and plays an important role for a wide range of astrophysical phenomena. In recent years, new IR facilities have provided powerful new data for understanding these phenomena. However, interpretation of these data is often complicated by a lack of complementary information about the optical properties of astronomically relevant materials. The Optical Properties of Astronomical Silicates with Infrared Techniques (OPASI-T) program at NASA's Goddard Space Flight Center is designed to provide new high-quality laboratory data from which we can derive the optical properties of astrophysical dust analogues. This program makes use of multiple instruments, including new equipment designed and built specifically for this purpose. The suite of instruments allows us to derive optical properties over a wide wavelength range, from the near-IR through the millimeter, also providing the capability for exploring how these properties depend upon the temperature of the sample. In this paper, we discuss the overall structure of the research program, describe the new instruments that have been developed to meet the science goals, and demonstrate the efficacy of these tools. 相似文献
3.
One dominant trend in magnetic disk recording has been rapidly increasing areal bit density. This has been accompanied by lower head flying heights, which has caused the disk surface smoothness and flatness to be of greater concern. One technique for evaluating the surface is to fly a 3330 type slider equipped with a piezoelectric crystal instead of a read/write head. The output of the piezo-electric crystal is monitored as the full recording band of the disk surface is traversed. Isolated bursts of activity are interpreted as head contacts with flaws on the disk surface. However, even in the absence of such head hits there may be a high output from the burnish head, which we refer to as "burnish noise". Heads flying on such high burnish noise disks generate substantial audible noise accompanied by high head wear rates. In this investigation we have shown the relationship between burnish noise and the high frequency axial acceleration of the disk surface. 相似文献
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Lau J Fowler J Marriage T Page L Leong J Wishnow E Henry R Wollack E Halpern M Marsden D Marsden G 《Applied optics》2006,45(16):3746-3751
We have developed and tested an antireflection (AR) coating method for silicon lenses used at cryogenic temperatures and millimeter wavelengths. Our particular application is a measurement of the cosmic microwave background. The coating consists of machined pieces of Cirlex glued to the silicon. The measured reflection from an AR-coated flat piece is less than 1.5% at the design wavelength. The coating has been applied to flats and lenses and has survived multiple thermal cycles from 300 to 4 K. We present the manufacturing method, the material properties, the tests performed, and estimates of the loss that can be achieved in practical lenses. 相似文献
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T. Stevenson D. Benford C. Bennett N. Cao D. Chuss K. Denis W. Hsieh A. Kogut S. Moseley J. Panek G. Schneider D. Travers K. U-Yen G. Voellmer E. Wollack 《Journal of Low Temperature Physics》2008,151(1-2):471-476
We describe a prototype detector system designed for precise measurements of Cosmic Microwave Background polarization. The
design combines a quasi-optical polarization modulator, a metal feedhorn, a superconducting planar microwave circuit, and
a pair of transition-edge sensor (TES) bolometers operating at <100 mK. The circular feedhorn produces highly symmetric beams
with very low cross-polarization. The planar circuit preserves symmetry in coupling to bolometers measuring orthogonal polarizations.
We implement the circuit with superconducting niobium transmission lines. Three-dimensional interfaces between the planar
circuit and waveguides leading to feedhorn and backshort have been carefully designed with electromagnetic simulations. Power
is thermalized in resistors and conducted to bolometers via normal electrons. Our system is designed for a 29–43 GHz signal
band. We have tested individual circuit elements in this frequency range. Fabrication of a full single-pixel system is underway.
相似文献
8.
Ari-David Brown Regis Brekosky David Franz Wen-Ting Hsieh Alexander Kutyrev Vilem Mikula Timothy Miller S. Harvey Moseley Joseph Oxborrow Karwan Rostem Edward Wollack 《Journal of Low Temperature Physics》2018,193(5-6):675-680
The high-resolution mid-infrared spectrometer (HIRMES) is a high resolving power (R ~?100,000) instrument operating in the 25–122 μm spectral range and will fly on board the Stratospheric Observatory for Far-Infrared Astronomy in 2019. Central to HIRMES are its two transition edge sensor (TES) bolometric cameras, an 8 × 16 detector high-resolution array and a 64 × 16 detector low-resolution array. Both types of detectors consist of Mo/Au TES fabricated on leg-isolated Si membranes. Whereas the high-resolution detectors, with a noise equivalent power (NEP) ~ 1.5 × 10?18 W/rt (Hz), are fabricated on 0.45 μm Si substrates, the low-resolution detectors, with NEP ~ 1.0 × 10?17 W/rt (Hz), are fabricated on 1.40 μm Si. Here, we discuss the similarities and differences in the fabrication methodologies used to realize the two types of detectors. 相似文献
9.
B. T. Bulcha G. Cataldo T. R. Stevenson K. U-Yen S. H. Moseley E. J. Wollack 《Journal of Low Temperature Physics》2018,193(5-6):777-785
The design of a two-dimensional spatial beam-combining network employing a parallel-plate superconducting waveguide filled with a monocrystalline silicon dielectric substrate is presented. This component uses arrays of magnetically coupled antenna elements to achieve high coupling efficiency and full sampling of the intensity distribution while avoiding diffractive losses in the multimode waveguide region. These attributes enable the structure’s use in realizing compact far-infrared spectrometers for astrophysical and instrumentation applications. If unterminated, reflections within a finite-sized spatial beam combiner can potentially lead to spurious couplings between elements. A planar meta-material electromagnetic absorber is implemented to control this response within the device. This broadband termination absorbs greater than 0.99 of the power over the 1.7:1 operational band at angles ranging from normal to near-parallel incidence. The design approach, simulations and applications of the spatial power combiner and meta-material termination structure are presented. 相似文献