Simulation of generation and losses of He and N ions in a multicharged-ion cyclotron source

Processes of production and losses of He and N ions with regard to previously-known approaches have been simulated with the aim of obtaining intense ion beams and ion high-charge states in a cyclotron source of multicharged ions. The model has been selected on the condition of plasma quasineutrality. Ions were produced in the process of successive ionization. Numerical integration of the self-contained set of linear 1st-order normal differential equations by the Runge-Kutt method has been carried out. The quantitative agreement of calculation results for He with experimental ones has been obtained at the following model parameters: Tsub(e) (electron temperature) 15 Ev, tau (time of ion escape from charge) 10-5 s, a (impact ionization coefficient) 10-11 cm3xs-1. Agreement of calculated data for N with experimental ones has been attained at Tsub(e)=30 eV, tau=2.5x10-6 s, a=Z2x10-11 cm-3xs-1, where Z is the ion charge