Stationary magnetic field which necessary to electron cyclotron resonance formed by permanent magnets from alloy NeFeB. Computer simulation by code ANSYS allows us to find such configuration of permanent magnets that gives magnetic field strength equal 875 mT at input and output hole. Regulation of magnetic field distribution provides by special iron bars. Also, computer simulation shows that even slight change of position of the bars results to significant changes of ionization rate in resonators volume. This provides necessary conditions for effective ionization of gas in volume of the resonator. Ions highest production rate corresponds to resonance amplification coefficient equal 105.