| タイトル | SHARC II: A Caltech Submillimeter Observatory Facility Camera with 384 Pixels |
| 本文（外部サイト） | http://hdl.handle.net/2060/20030016723 |
| 著者（英） | Allen, Christine A.; Kovacs, Attila; Gardner, Matthew B.; Freund, Minoru; Dowell, C. Darren; Jhabvala, Murzy; Babu, Sachidananda; Groseth, Jeffrey; Lis, Dariusz C.; Moseley, S. Harvey, Jr. |
| 著者所属（英） | NASA Goddard Space Flight Center|California Inst. of Tech. |
| 発行日 | 2002-01-01 |
| 言語 | eng |
| 内容記述 | SHARC II is a background-limited 350 micron and 450 micron facility camera for the Caltech Submillimeter Observatory undergoing commissioning in 2002. The key component of SHARC II is a 12 x 32 array of doped silicon 'pop-up' bolometers developed at NASA/Goddard. Each 1 mm x 1 mm pixel is coated with a 400 Omega/square bismuth film and located lambda/4 above a reflective backshort to achieve greater than 75% absorption efficiency. The pixels cover the focal plane with greater than 90% filling factor. At 350 microns, the SHARC II pixels are separated by 0.65 lambda/D. In contrast to the silicon bolometers in the predecessor of SHARC II, each doped thermistor occupies nearly the full area of the pixel, which lowers the 1/f knee of tile detector noise to less than 0.03 Hz, under load, at tile bath temperature of 0.36 K. The bolometers are AC-biased and read in 'total power' mode to take advantage of the improved stability. Each bolometer is biased through a custom approx. 130 MOmega CrSi load resistor at 7 K and read with a commercial JFET at 120 K. The JFETs and load resistors are integrated with the detectors into a single assembly to minimize microphonic noise. Electrical connection across the 0.36 K to 4 K and 4 K to 120 K temperature interfaces is accomplished with lithographed metal wires on dielectric substrates. In the best 25% of winter nights on Mauna Kea, SHARC II is expected to have an NEFD at 350 micron of 1 Jy Hz(sup -1/2) or better. The new camera should be at least 4 times faster at detecting known point sources and 30 times faster at mapping large areas compared to the prior instrument. |
| NASA分類 | Instrumentation and Photography |
| レポートNO | Rept-2002-5 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/90508 |
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