Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Experimental observation of neoclassical currents

Technical Report ·
OSTI ID:6948258

The parallel and perpendicular equilibrium currents have been experimentally studied in the Levitated Octupole, with toroidal field. Observations of the spatial structure, collisionality and toroidal field dependence of the complete current and the ion portion of the current are presented. Experimentally measured currents are compared to neoclassical current distributions calculated for the actual machine geometry. Measurements of the total plasma parallel current for absolute-MHD-stable flux surfaces (inside the separatrix) agree well with theory, showing the bootstrap and Pfirsch-Schlueter currents as predicted by neoclassical transport theory. On average-MHD-stable flux surfaces (outside the separatrix) there is more parallel current than predicted by theory, though the spatial structure is correct. Separate measurements of the ion parallel and perpendicular currents agree with theory, showing the lack of measurable ion poloidal rotation in all situations.

Research Organization:
Wisconsin Univ., Madison (USA). Dept. of Physics
DOE Contract Number:
AC02-83ER53154
OSTI ID:
6948258
Report Number(s):
DOE/ER/53154-67; ON: DE84015113
Country of Publication:
United States
Language:
English