Experimental studies of linear high‐beta heliac plasma configurations

Autor: Mark Koepke, C. M. Greenfield, F. L. Ribe
Rok vydání: 1990
Předmět:
Zdroj: Physics of Fluids B: Plasma Physics. 2:133-142
ISSN: 0899-8221
Popis: The formation and quasi‐equilibrium of a high‐beta heliac plasma are investigated in the High‐Beta Q Machine [Phys. Fluids 30, 2885 (1987)], a linear high‐beta l=1 stellarator with an internal current carrying conductor (hardcore). The hardcore current rise time is varied from 9 μsec to smaller values comparable with that of the main compression field (450 nsec). Flux contours and plasma pressure calculated from internal magnetic‐probe measurements are used to distinguish between nearly axisymmetric plasma confined near the hardcore and the heliac plasma confined near the magnetic axis. For the shorter hardcore rise times, the axisymmetric plasma pressure becomes small compared to that of the heliac. Further analysis of the data allows calculation of the currents flowing in the plasma, the rotational transform, and the magnetic well depth. Appreciable axial current is observed, consistent with induction by the changing magnetic fields during the heliac formation. The observed relationship between the axia...
Databáze: OpenAIRE