中川 貴雄

Experimental studies are carried out to clarify the structures and erosive properties of rectangular cavitating jets. The jet is supplied from a high pressure pump and injected through a rectangular nozzle of aspect ratio of two or four. It discharges into a test cell at specified constant pressure and impinges against a test specimen of aluminum alloy. The structures of the jets are observed by instantaneous photographs and high-speed movies. The erosion tests are conducted at the injection pressure of 18 MPa and the cavitation number of 0.01, 0.02, and 0.03. It is shown that the structures of the cavitating jets issuing from the rectangular nozzles are completely different from those of circular cavitating jets. Corresponding to the jet structures, the erosive properties of the rectangular cavitating jets are different from those of the circular cavitating jets.

資料番号: SA4583057000

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.

資料番号: SA4592186000

Ge:Ga 外囚性半導体を用いた光伝導型検出器は、波長110μmまで感度を持つ遠赤外検出器であり、天文観測や、遠赤外分光など高感度が必要な分野に用いるため研究開発が行われてきた。現在衛星搭載用観測装置のフォーカル・プレーン検出器として各国で研究が進められており、我が国においても次期赤外天文衛星(IRIS)の遠赤外サーベイヤー装置の焦点部にGe:Ga遠赤外検出器が搭載される予定である。検出器の多素子化は同空間分解で同時観測可能領域の拡大をもたらし、観測の効率化及び精度の向上に寄与する。我々は検出器の二次元化を目指し、アレイ化に適した構造である透明電極を用いたLongitudinal型Ge:Ga検出器を開発し、それを極低温動作読み出し回路にインジウムを用いて直接コンタクトをとるダイレクトハイブリッド構造の開発を行った。