Plasma and Fusion Research
Volume 2, S1053 (2007)
Regular Articles
- National Institute for Fusion Science, Toki 509-5292, Japan
Abstract
Three emission lines of neutral helium, i.e., the λ 667.8 nm (21P-31D), λ 728.1 nm (21P-31S), and λ 706.5 nm (23P-33S) lines, are observed with an array of parallel lines-of-sight which covers an entire poloidal cross section of the plasma in the Large Helical Device (LHD). Their emission locations and intensities are determined from the Zeeman profiles. The electron temperature and density are evaluated from intensity ratios among the observed emission lines at each emission location and the poloidal distribution of ionization flux or its equivalent quantity, inward neutral particle flux, is derived with the help of collisional-radiative model calculations. A relatively strong neutral flux is observed at the inboard-side X-point and this result implies a high particle recycling in the inboardside divertor region. The result is consistent with the ion flux distribution onto the helically located divertor plates measured with Langmuir probes.
Keywords
spectroscopy, helium, Zeeman effect, collisional-radiative model
Full Text
References
- [1] M. Goto and S. Morita, Phys. Rev. E 65, 026401 (2002).
- [2] M. Goto, K. Sawada, and T. Fujimoto, Phys. Plasmas 9, 4316 (2002).
- [3] T. Fülöp, P. Helander and Peter J. Catto, Phys. Rev. Lett. 89, 225003 (2002).
- [4] B. Schweer, G. Mank, A. Pospieszczyk, B. Brosda, and B. Pohlmeyer, J. Nucl. Mater. 196-198, 174 (1992).
- [5] M. Goto, J. Quant. Spectrosc. Radiat. Transf. 76, 331 (2003).
- [6] M. Goto and S. Morita, Rev. Sci. Instrum. 77, 10F124 (2006).
- [7] S. Masuzaki, T. Morisaki, N. Ohyabu et al., Nucl. Fusion 42, 750 (2002).
- [8] R.L. Boivin, J.A. Goetz, A.E. Hubbard et al., Phys. Plasmas 7, 1919 (2000).
- [9] T. Morisaki, S. Sakakibara, K.Y. Watanabe et al., Contrib. Plasma Phys. 40, 266 (2000).
This paper may be cited as follows:
Motoshi GOTO and Shigeru MORITA, Plasma Fusion Res. 2, S1053 (2007).