Analytic Approximations for Describing the Interaction of Charged Particles with the Emitter of a Radioisotope Current Source

Approximate formulas for the modeling of the interaction of fast alpha particles and suprathermal electrons with solid-state plasmas of the emitter films in a secondary-electron-emission radioisotope current source are derived. The approximate formulas are used to estimate the characteristic interaction parameters, in particular, the effective stopping power of the composite material of the emitter, the ranges of alpha particles, the optimum thickness of the emitter, and the maximum possible number of binary current cells. The results obtained can be used to optimize the parameters of a prototype model of such a source and to analyze its current–voltage characteristic. They can also be applied in Monte Carlo modeling of the generation of suprathermal electrons by fast ion fluxes in a solid-state plasma and ion flux–induced fast nonequilibrium secondary electron emission from metallic and dielectric films.