Pre-ionization for high-density, high-field Field-Reversed Configuration formation *

The performance of Field-Reversed Configuration (FRC) formation and the properties of the resulting equilibria strongly depend on the parameters of the pre-ionized plasma prior to field-reversal. In order to optimize these initial conditions, several pre-ionization methods have been investigated including ringing-theta pre-ionization, injection of plasma using an annular array of rail guns, and any additional ionization due to field-reversal. The utility and initial results of these techniques are discussed in the context of formation at high densities and high reverse bias field made possible by new high-voltage, low-inductance reversal systems under development at Los Alamos National Laboratory.