High-beta plasma production and confinement in screw pinch TPE-2

A high-beta plasma of βt∼0.1 and εβp>2 is produced and its confinement properties are studied in a screw pinch of moderately elongated cross section. The initially constricted high-beta plasma column is surrounded by a force-free current layer and expands radially. The energy confinement time is much less than that from the empirical scaling of an ohmically heated tokamak, but it gradually improves as βp decreases. The fast plasma-energy decay and the fast boundary diffusion are considered to be caused by the ballooning mode. (author)