Formation of an oblate FRC from a single flux-core coil in the TS-6 plasma device

The field-reversed configuration (FRC) is a high β torus plasma with only poloidal magnetic field in its idealized form. Traditional formation methods for prolate FRCs have relied on theta-pinch formation, while oblate FRCs have been formed through spheromak merging. In this work, we report a novel method for forming an oblate FRC through plasma discharge from a single flux-core coil. We have observed that by introducing time delay in poloidal field (PF) reversal between the two flux-core coils, an initially formed spheromak-like plasma linked with a flux-core coil will split into a spheromak and an oblate FRC. The magnetic field profile is measured with a 2D array of B-dot probes on a poloidal cross section. Low-n toroidal mode activities are measured with B-dot probes located at 8 toroidal locations. The result suggests the possibility of quasistatic formation of FRC with a single plasma gun.