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Title: Initial ionization stage of FRC formation

Conference ·
OSTI ID:6752300

A Field-Reversed Configuration (FRC) is a prolate compact torus that is confined by poloidal fields only. Theta-pinch formation of an FRC employs an initial bias field, B/sub 1/, whose direction is opposite to that of the main theta-pinch field. Some fraction of the flux associated with this bias field eventually constitutes the closed-field-line flux of the FRC. Experimental and theoretical evidence suggest that the longest-lived FRC's are obtained when the closed flux is maximized. Because the initial ionization is done in the presence of the bias field, the actual bias flux available at the time of application of the main theta-pinch field depends strongly on the initial ionization, or preionization, technique used. In this paper we report on experiments characterizing the previously used theta-pinch preionization technique that employed a net field (bias plus preionization) null, or zero-crossing, of the axial component of the magnetic field to break down the gas. We also discuss results of experiments designed to develop preionization techniques in which the gas breakdown is not accomplished by a zero-crossing.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
DOE Contract Number:
W-7405-ENG-36
OSTI ID:
6752300
Report Number(s):
LA-UR-80-3214; CONF-801215-8; TRN: 81-001629
Resource Relation:
Conference: 3. symposium on the physics and technology of compact toroids in the magnetic fusion energy program, Los Alamos, NM, USA, 2 Dec 1980
Country of Publication:
United States
Language:
English