On the problem of noise and charge conservation in particle simulations

The particle simulation algorithm is considered conserving the charge in grid cells. The current timeaveraging procedure is used. The current is averaged over time interval that is a measure of the period that a particle runs over grid cell. The purpose of this procedure is the smoothing of electromagnetic noise. The considered particle simulation algorithm is realized in the problem of axial-symmetric electromagnetic field generation by relativistic electron beam passing through cylindrical resonator. Numerical results illustrate advantages of realized algorithm. These advantages are due to charge conservation and current time-averaging procedure.