Advanced PICOP algorithm with adaptive meshless field solver

We have developed a new advanced Particle-In- Cloud-Of-Points (PICOP) algorithm, which solves macro particle motion equations using a meshless point structure (a cloud of points) as a reference basis to compute electrostatic fields. The cloud of points is iteratively adapted (number of points and their locations are varied) to the field structure. That allows resolving boundary and current layers, sheaths, etc. simultaneously with solution to an initial problem. The algorithm was applied to model ion extraction from an electron cyclotron resonance ion source (ECRIS). The IonEx code has been developed. The code computes the steady state trajectories of the extracted ions and the electrostatic potential from Poisson’s equation self-consistently, assuming Boltzmann distribution for electrons. The process leads to the formation of a few microns thick plasma sheath inside extraction optics a few centimeters in size. The code resolves the potential drop in the sheath by adaptation of the cloud of points. Benchmark and numerical simulation of ion beam extraction are presented.