Attainment of high confinement in neutral beam heated divertor discharges in the PDX tokamak

S. M. Kaye, M. G. Bell, K. Bol, D. Boyd, K. Brau, D. Buchenauer, R. Budny, A. Cavallo, P. Couture, T. Crowley, D. S. Darrow, H. Eubank, R. J. Fonck, R. Goldston, B. Grek, K. P. Jaehnig, D. Johnson, R. Kaita, H. Kugel, B. LeblancJ. Manickam, D. Manos, D. Mansfield, E. Mazzucato, R. McCann, D. McCune, K. McGuire, D. Mueller, A. Murdock, M. Okabayashi, K. Okano, D. K. Owens, D. E. Post, M. Reusch, G. L. Schmidt, S. Sesnic, R. Slusher, S. Suckewer, C. Surko, H. Takahashi, F. Tenney, H. Towner, J. Valley

Research output: Contribution to journalArticle

143 Citations (Scopus)

Abstract

The PDX divertor configuration has recently been converted from an open to a closed geometry to inhibit the return of neutral gas from the divertor region to the main chamber. Since then, operation in a regime with high energy confinement in neutral beam heated discharges (ASDEX H-mode) has been routine over a wide range of operating conditions. These H-mode discharges are characterized by a sudden drop in divertor density and Hα emission and a spontaneous rise in main chamber plasma density during neutral beam injection. The confinement time is found to scale nearly linearly with plasma current, but can be degraded due either to the presence of edge instabilities or heavy gas puffing. Detailed Thomson scattering temperature profiles show high values of Tc near the plasma edge (∼ 450 eV) with sharp radial gradients (∼ 400 eV/cm) near the separatrix. Density profiles are broad and also exhibit steep gradients close to the separatrix.

Original languageEnglish
Pages (from-to)115-125
Number of pages11
JournalJournal of Nuclear Materials
Volume121
Issue numberC
DOIs
Publication statusPublished - 1984 May 1

    Fingerprint

ASJC Scopus subject areas

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

Cite this

Kaye, S. M., Bell, M. G., Bol, K., Boyd, D., Brau, K., Buchenauer, D., Budny, R., Cavallo, A., Couture, P., Crowley, T., Darrow, D. S., Eubank, H., Fonck, R. J., Goldston, R., Grek, B., Jaehnig, K. P., Johnson, D., Kaita, R., Kugel, H., ... Valley, J. (1984). Attainment of high confinement in neutral beam heated divertor discharges in the PDX tokamak. Journal of Nuclear Materials, 121(C), 115-125. https://doi.org/10.1016/0022-3115(84)90111-9