The Japanese infrared astronomical satellite, ASTRO-F, employs the Far-Infrared Surveyor (FIS) for all sky survey. The FIS has two detector arrays; one covers from 50 to 110 μm wavelength, the other covers from 110 to 200 μm. Each of them uses Ge:Ga operating at 2K. We have developed and evaluated the preamplifiers for these detector arrays. The preamplifiers are required to work at 2K with low noise and low power dissipation. In this paper, we report on the development and evaluation of these cryogenic preamplifiers.
The ASTRO-F project is currently in its final stage of proto-model, which is constructed same as flight-model. Since instrument goals of the Far-Infrared Surveyor (FIS) are unprecedented achievement of high sensitivity and high spatial resolution in far-infrared wavelength, the proto- model stage is important to prove the performance as the flight instrument. We mainly present here the latest optical, thermal, and mechanical properties of the proto- model of the FIS.