Analysis of discharge characteristics of the inertial electrostatic confinement fusion using a particle code with Monte Carlo collision scheme

In this paper, we study the mechanism of a self-maintaining discharge in the Inertial Electrostatic Confinement Fusion (IECF) with D₂ gas. We developed a 1-D particle code with Monte Carlo collision scheme including atomic and molecular processes of ion, energetic neutral, and electron impact based on the PDS-1 code. Also we developed the energy dependent transparency model of the cathode, and applied constant discharge current control to simulate a steady discharge. As electrons are accelerated quickly just outside of the cathode, electron impact ionization hardly occurred outside the cathode. Therefore, the quantity of D₂⁺ supplied by electron impact ionization is not enough to maintain a discharge. From the simulation, we found that D₂⁺ impact charge-exchange and D₂⁰ impact re-ionization contribute greatly to maintain a discharge.