稲富 裕光

In the phase analysis, accuracy can degrade when the intensity of bright and dark lines in interference fringes varies significantly spatially, or when the phase change Δφ is temporally discontinuous. In this study, we improved the interference fringe analysis method by focusing on a local region in phase analysis and classifying phase inter-frame differences δφ’ in phase unwrapping. The objective of this study is to clarify how to set the threshold for classifying δφ’ and the accuracy of the phase φ and phase change Δφ obtained by the proposed method. Both experimentally obtained in a microgravity and artificially generated interference fringes were analyzed using the proposed method. As a result, the obtained spatial distribution of Δφ had a few outliers. In addition, it was revealed that a reliable threshold for classifying δφ’ can be automatically determined by using the total amount of tolerable noise and estimated δφ’. The phase error and the phase change error were as small as 0.025π and 0.034π rad, respectively, which is less than one-fifth of the conventional method.

<p>国際宇宙ステーション「きぼう」利用簡易曝露実験装置ExHAMを利用した炭素質ダストの宇宙曝露実験は，年老いた星周環境で凝縮したダストが星間空間に至り次世代の星形成活動に寄与するまでの過程で被る物性変化を調べることを目的とする試みである．本実験では，未同定赤外バンド担い手の同定に焦点をあて，実験室で合成するダストである膜状急冷炭素質物質をはじめとして，約30種の実験試料を1年間，国際宇宙ステーションの軌道環境に曝露し，曝露前後の物質の赤外分光特性や物性変化の調査を実施している．この記事では，本曝露実験の概要と進捗状況を示すとともに，主要な実験試料の1つである膜状急冷炭素質物質に焦点をあて，宇宙環境曝露実験前後での赤外線吸光スペクトルの変化に関する初期成果の一部を紹介する．</p>

InxGa1−xSb bulk crystal was grown using a GaSb (seed)/InSb/GaSb (feed) sandwich-structured system onboard the International Space Station (ISS). In order to investigate the transport phenomena especially in terms of interface shapes and dissolution heights, the dissolution process was simulated under a micro-gravity level of the ISS. Simulation results showed that the seed/melt interface was concave towards the seed due to the temperature distribution of the system. This prediction is in good agreement with the results of our previous experimental study.