Initial Results of Multi-pulse Compact Toroid Refueling in the C-2W Field-Reversed Configuration

One of the limiting factors in the lifetime of a field-reversed configuration (FRC) is particle loss. To refuel the long-lived FRC plasma in the C-2W experiment a multi-pulse compact toroid injector (CTI) has been developed. Refueling is accomplished with two radially oriented magnetized coaxial plasma guns (MCPG), diametrically opposed on the mid-plane of the confinement vessel. The MCPG consists of puff valves, a quasi-DC iron-core magnet providing the compact toroid’s (CT) stuffing flux, a pre-ionizer system to improve breakdown and decrease jitter, in addition to coaxial electrodes where the CT is formed and accelerated. These systems allow for the creation of a relatively hot spheromak-like CT, while limiting excess neutral gas. The multi-pulse capability is achieved with individual pulsed power supplies for each CT for a total of 5 CT’s from each of the two injectors at a repetition rate up to 1kHz. Initial results, including CT parameters and effects on the FRC will be presented.