Space charge oscillations in gyrotron magnetron-injection guns with high pitch-factor

The data of numerical simulation of gyrotron magnetron-injection guns (MIGs) forming helical electron beams (HEBs) with high pitch-factor are presented. The HEBs parameters for the regimes with big value of the locked into the adiabatic trap space charge are found. It is shown that if the magnetic compression ratio or the anode potential is high enough to cause the intense space charge oscillations in the beam, the values of the pitch-factor and velocity spread are saturated while the oscillations of the space charge and potential in the beam continue to increase.