The effect of divertor tile material on radiation profiles in LHD

B. J. Peterson, S. Masuzaki, R. Sakamoto, K. Sato, S. Inagaki, A. Sagara, S. Ohdachi, Y. Nakamura, N. Noda, Y. Xu, J. E. Rice, N. Ashikawa, S. Yamamoto, M. Takechi, K. Toi, S. Morita, M. Goto, K. Narihara, N. Inoue, Y. TakeiriM. Sato, M. Osakabe, K. Tanaka, T. Tokuzawa, S. Sakakibara, M. Shoji, K. Kawahata, O. Kaneko, N. Ohyabu, H. Yamada, A. Komori, K. Yamazaki, S. Sudo, O. Motojima

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

In the large helical device (LHD) radiation profiles measured using arrays of resistive metal, foil bolometers are used to investigate the change in radiation resulting from a replacement of stainless steel divertor plates with graphite tiles between the second and third experimental campaigns. In particular, for the magnetic configuration of Aaxis -3.6 m and at line averaged densities below 3 × 1019 m-3, a reduction of the radiated power fraction from 35% in the second campaign to down to 12% in third campaign was observed. Comparing similar shots (in terms of discharge parameters) from the second and third cycles the core (0 < r/a. < 0.79) radiation fraction was reduced from 44% to 30% of the total radiation. Spectroscopic measurements show a corresponding decrease in radiation from iron. Comparing long pulse discharges the radiated power fraction reduced from greater than 67% during the density limiting oscillation observed in the second campaign to 20% during the third campaign with a reduction in the respective core radiation fractions from 63% to 37%.

Original languageEnglish
Pages (from-to)930-934
Number of pages5
JournalJournal of Nuclear Materials
Volume290-293
DOIs
Publication statusPublished - Mar 2001
Externally publishedYes

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Materials Science(all)
  • Nuclear Energy and Engineering

Cite this

Peterson, B. J., Masuzaki, S., Sakamoto, R., Sato, K., Inagaki, S., Sagara, A., ... Motojima, O. (2001). The effect of divertor tile material on radiation profiles in LHD. Journal of Nuclear Materials, 290-293, 930-934. https://doi.org/10.1016/S0022-3115(00)00460-8