Takao Nakagawa

The Far-Infrared Surveyor (FIS) is one of the on-board instruments on the ASTRO-Fsatellite, which will be launched in early 2004. The first a half year of its mission period of 500days is dedicated to an all sky survey in four bands between 50 and 200μm. On the basis of thepresent hardware specfications and configurations of the FIS, we have written a computer programto simulate the FIS. The program can be used to evaluate the performance of the instrument aswell as to produce input for the data reduction system. In this paper, we describe the currentstatus of the program. As an example of the usage of the simulation program, we present theexpected observing data for three different detector sampling rates. The functions which shouldbe implemented into the program, in the future, are enumerated.

Current idea of focal plane instruments onboard HII/L2 (SPICA) mission is described.To squeeze out maximum scientific output, the instruments cover 2-200 μm in both imaging modeand spectroscopic mode.

Gallium-doped germanium (Ge:Ga) extrinsic semiconductors have been used as sensitive far-infrared detectors with a cutoff wavelength of 110μm (3 THz), especially in the fields of astronomy, the spectroscopy of molecules and solids, and plasma diagnostics. Developing Ge:Ga photoconductor arrays to take two-dimensional THz images is now an important target for such research fields as the space astronomy. We are developing Ge:Ga far-infrared photoconductor direct hybrid arrays for use as focal-plane detectors in the Far Infrared Surveyor (FIS), one of the two main instruments of the Infrared Imaging Surveyor (IRIS) satelite that will be launched in 2003. In this paper, we report on the basic idea of a 20×3 Ge:Ga far-infrared photoconductor array directly hybridized to a Si p-MOS readbut integrated circuit (IC) using indium bump technology, and give the results of vibration and cooling tests conducted to confirm the strength of the direct hybrid structure.