High β compact toroidal equilibria

Abstract

The relationship of the recently proposed tokamak with spheromak shell (STSS) with other compact equilibria in the low aspect ratio A regime, e.g., spherical tokamaks, field reversed configurations, is studied. It is shown that these equilibria are complementary to equilibria with a magnetic hole studied earlier by Cowley et al. [S. C. Cowley, P. K. Kaw, R. S. Kelly, and R. M. Kulsrud, Phys. Fluids B 3, 2066 (1991)] in the large A regime. The former is perfectly paramagnetic while the latter is perfectly diamagnetic. Relevance of these results to the study of compact equilibria conducted recently on Tokyo University Spherical Torus(TS)-3 and TS-4 [M. Inomoto, Y. Ueda, Y. Ono, T. Murakami, M. Tsurda, M. Yamada, and M. Katsurai, Proceedings of the 17th Conference on Fusion Energy, Yokohama, 1998 (International Atomic Energy Agency, Vienna, 1998), Vol. 3, p. 927] is briefly discussed.