Preliminary findings from efforts to model pulsed inductive theta-pinch plasmas via Particle-In-Cell

Abstract

A method is pursued to approximately model the electron energy distribution of pulsed inductive plasma devices with Particle-In-Cell code to elucidate formation physics during early times (t < 1 μs). Specifically, reported results from AFRL-Kirtland's pulsed inductive device, FRCHX, are used as a test case to validate results. An r-z slab approximation is outlined and gyro-frequency, Larmor radius, and E×B guiding center drift are verified against theory to within 1% difference. The analyses presented, using both single electron and Particle-In-Cell modeling, agree with FRCHX reported results by showing that average electron kinetic energy does not exceed the ionization threshold of 15.47 eV for gaseous deuterium until after the first ¼ cycle of the ringing pre-ionization stage (when net magnetic field is approximately nullified). These results provide supportive evidence for the concept that bias field actually inhibits ionization if improperly implemented.

Effects of Three Typical Resistivity Models on Pulsed Inductive Plasma Acceleration Modeling

“…In 2012, the PIC code was adopted to research the pre-ionization physical process for conical coils at Missouri University of Science and Technology. [11] They found that the bias field would inhibit the pre-ionization process of plasma if the electric field is mismatched.…”