Experimental study and numerical simulation of electron beam in gyrotron-type electron-optical systems

The most widely used system of helical electron beam (HEB) formation for gyrotron applications includes a magnetron-injection gun (MIG) and magnetic compression region. In this system, it is necessary to take into account such specific phenomena as the reflection of electrons with large transverse velocities from magnetic mirror, the accumulation of the space charge in the trap between gun cathode and magnetic field plateau, the excitation of low-frequency "trap" oscillations, the electron bombardment of cathode surface. These phenomena have an effect on HEB quality and limit gyrotron parameters. In our paper, the results of experimental study and numerical simulation of physical processes accompanying HEB formation are summarized.