Development of a Time-Independent Particle-in-Cell Code for Simulating DC Discharges in Inertial Electrostatic Confinement Devices

A two-dimensional numerical code has been developed for simulating dc discharges in inertial electrostatic confinement (IEC) fusion devices. Unlike the existing IEC codes, the developed code is not based on Monte Carlo scheme by the use of random number nor time-domain particle-in-cell (PIC) method, aiming at a drastic reduction of computational efforts. It is based on a time-independent scheme, i.e. iterative calculations of particle-tracking and induced self-field, leading to a much faster convergence than the time-domain PIC scheme on steady-state self-consistent solutions. Also, a new scheme for atomic process treatment is proposed, which is completely free from the inherent difficulty of Monte Carlo method, i.e. requiring many particles for simulating rare events. Preliminary numerical result from the this code showed agreement with experimental helium discharge characteristics in an IEC device.