2024-03-29T11:25:07Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00005446
2023-01-16T04:23:05Z
320:321:322
Comparison of He I line intensity ratio method and electrostatic probe for electron density and temperature measurements in NAGDIS-II
Kajita, Shin
Ohno, Noriyasu
Takamura, Shuichi
Nakano, Tomohide
open access
Copyright (2006) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
The electron density and temperature obtained from the line intensity ratio method of He I (λ=667.8, 706.5, and 728.1 nm) are compared to the probe method in a divertor simulator. When a collisional radiative model that does not include the effect of the radiation transport was used for the analysis, ne obtained from the spectroscopic method was significantly higher than that from the electrostatic probe method. The discrepancy between the two methods increases with the gas pressure; in other words, it increases with the optical thickness. In the case that the effect of the radiation trapping is taken into consideration using optical escape factor, the discrepancy becomes moderate. And then, the parameters obtained from the line intensity ratio method agree with the probe method within a factor of 2 in the case that the radiation trapping was introduced with R=0.05 m, which corresponds to the column radius of the spatial profile of the excited population density. In recombining plasmas, however, it was shown that the line intensity ratios might not be appropriate because the recombining component broke the monotonic increase/decrease dependences of the line intensity ratios on ne and Te. A measurement of another He I line intensity of 447.1 nm (2^3P←4^3D) is proposed for solving the problem.
9pages
American Institute of Physics
2006-01
eng
journal article
VoR
http://hdl.handle.net/2237/7050
https://nagoya.repo.nii.ac.jp/records/5446
https://doi.org/10.1063/1.2164461
1070-664X
Physics of Plasmas
13
1
013301
013301
https://nagoya.repo.nii.ac.jp/record/5446/files/PhysPlasmas_13_013301.pdf
application/pdf
717.8 kB
2018-02-19