Formation of intense relativistic helical electron beam with high pitch-factor

A magnetron-injection gun for the Ka-band relativistic gyrotron is developed. By decreasing time to come electrons to the high potential area, this gun gives the possibility to increase the operating current up to 50% of the Langmuir gun current. High quality of the beam at the operating regime was confirmed experimentally by using the velocity distribution analyzer based on separation of different fractions of electrons in adiabatically increased magnetic field. High gyrotron efficiency (50%) confirms this statement also.