RFP behavior at various F values in the MS

Plasma behavior is tracked as the reversal parameter F of the Madison Symmetric Torus (MST) is varied from -0.3 to 0.2 with corresponding pinch parameter θ from above 1.8 to under 1.2. The general plasma properties are quite similar for all F values, but significant differences exist: (1) Both magnetic and electrostatic fluctuations are minimum when the reversal is shallow (F = -0.1). (2) Plasma resistance is minimum and the conductivity temperature is maximum at shallow reversed plasma. (3) Enhanced plasma-wall interaction is found when F > 0. Periodic oscillations called flux jumps, or sawtooth oscillations, are seen on various diagnostics throughout most of the F-scan, but a dependence of amplitude and frequency on F is noted also. High-frequency (10-15 kHz) precursors associated with higher plasma temperature and longer plasma duration time are seen. Plasmas under various discharge conditions have been obtained and compared with standard discharges.