@techreport{oai:nifs-repository.repo.nii.ac.jp:00010048, author = {Narihara, K. and Toi, K. and Hamada, Y. and Yamauchi, K. and Adachi, K. and Yamada, I. and Sato, K. N. and Kawahata, K. and Nishizawa, A. and Ohdachi, S. and Sato, K. and Seki, T. and Watari, T. and Xu, J. and Ejiri, A. and Hirokura, S. and Ida, K. and Kawasumi, Y. and Kojima, M. and Sakakita, H. and Ido, T. and Kitachi, K. and Koog, J. and Kuramoto, H.}, month = {Mar}, note = {Laser scattering signals which indicate the presence of small dusts ( diameter leq 2 mu m) were occasionally observed in the JIPPT-IIU tokamak chamber. This phenomenon was reproduced by deliberately spreading carbon dusts from the top of the vacuum chamber. No noticeable effect on the plasma was observed for dust-fall of up to at least 10^6 dusts (10 mu g) in 20 ms during discharge. Dusts fallen just before the plasma start-up seemed to be confined but soon be ejected in less than 30 ms.}, title = {Observation of Dusts by Laser Scattering Method in the JIPPT-IIU Tokamak}, year = {1997} }