Berlin 2008 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 5: Superconductivity - Cryodetectors
TT 5.1: Vortrag
Montag, 25. Februar 2008, 11:30–12:00, H 3010
SABOCA - a multiplexed 37 channel bolometer camera for 350 micrometer wavelength — Torsten May1, Viatcheslav Zakosarenko1, Andre Krueger1, Solveig Anders1, Katja Peiselt1, •Hans-Georg Meyer1, Ernst Kreysa2, Giorgio Siringo2, and Walter Esch2 — 1Institute of Photonic Technology, Albert-Einstein-Str. 9, D-07745 Jena, Germany — 2Max-Planck-Institute for radio astronomy, Auf dem Huegel 69, D-52888 Bonn, Germany
Some of the most interesting objects in the Universe are only accessible through astronomical observations in a so far only sparsely used atmospheric window at sub millimeter wavelengths. The sub millimeter emission from molecular spectral lines and from warm dust allows an almost unhindered, unique view onto ongoing star forming regions and galactic nuclei, from our own Milky Way to the most distant galaxies and quasars in the early Universe. One of the best accessible sites for submillimeter observations is the high plateau Llano de Chajnantor in Chile's Atacama desert. At 5000 meter altitude APEX (Atacama Pathfinder Experiment), a 12 meter radio telescope, has seen first light in 2005. Due to its high surface accuracy this instrument is particularly suited to utilize one of last atmospheric radio windows on earth: the 350 micron band. The Small Array BOlometer CAmera (SABOCA) is scheduled to operate at APEX in spring 2008. It is an array of 37 transition edge sensors operated at a temperature of 300 mK, provided by a 3He sorption cooler on a cryostat with liquid 4He. The instrument is read out by SQUID current sensors in a time domain multiplexing scheme. Four integrated multiplexer chips, 10 first stage SQUIDs each, are placed next to the detector chip, operating at the same temperature. Every multiplexer chip is coupled to one amplifier SQUID. The four amplifier SQUIDs are placed at the 4He stage, with a temperature of 1.5K during operation. The signals are acquired by room temperature electronics and digitized by 24bit A/D converters. The data acquisition system limits the system clock to 2 kHz, resulting in an effective data rate of 200 Hz per channel.