  Important features of Electron Cyclotron Resonance Ion Source (ECRIS)
operation are accurately reproduced with a numerical code. The code uses the
particle-in-cell technique to model a dynamics of ions in ECRIS plasma. It is
shown that gas dynamical ion confinement mechanism is sufficient to provide the
ion production rates in ECRIS close to the experimentally observed values.
Extracted ion currents are calculated and compared to the experiment for few
sources. Changes in the extracted ion currents are obtained with varying the
gas flow into the source chamber and the microwave power. Empirical scaling
laws for ECRIS design are studied and the underlying physical effects are
discussed.
