-
Author(s):
S. Morita, H. Idei, H. Iguchi, S. Kubo, K. Matsuoka, T. Minami, S. Okamura, T. Ozaki, K. Tanaka, K. Toi, R. Akiyama, A. Ejiri, A. Fujisawa, M. Fujiwara, M. Goto, K. Ida, N. Inoue, A. Komori, R. Kumazawa, S. Masuzaki, T. Morisaki, S. Muto, K. Narihara, K. Nishimura, I. Nomura, S. Ohdachi, M.. Osakabe, A. Sagara, Y. Shirai, H. Suzuki, C. Takahashi, K. Tsumori, T. Watari, H. Yamada and I. Yamada
-
Title:
A Study on Density Profile and Density Limit of NBI Plasmas in CHS
Date of publication:
Sep. 1996
-
Key words:
Hydrogen neutral particle, Neutral energy, Density profile, Density limit, Plasma collapse
-
Abstract:
The mechanism of density profile formation has been studied in CHS. It has been generally known that the profiles become peaked and hollow in limiter- and divertor-dominated cases, respectively. This tendency does not change for the direction of NBI such as co- and counter-injection resulting a difference of the electric field. It is also found that the density profiles are not affected by the magnetic configuration itself. The density profile, however, is influenced by the limiter insertion. Edge ion temperatures were correlated with density peaking factor of n_e0 /< ne >. As a result, it was found that a peaked profile, (n_e0 /< ne > geq 1.5) can be obtained with higher edge ion temperature (geq 40ev at rho=0.9). These results indicate the importance of energy distribution of incoming neutral particles. An analysis is done to explain the results. On the other hand, the density limit has been also studied in CHS NBI plasmas. It was found that the density limit was strongly affected by the density profile. Some discussions are made on the mechanism related to the density limit.
-
|
