Design and Simulation Analysis of a Magnetron Injection Gun for a 0.42 THz Second Harmonic Gyrotron

Abstract

A double anode magnetron injection gun (MIG) for a 0.42 THz second harmonic gyrotron has been presented in this paper. Through design, simulation and optimization by the particle-in-cell code, a double-anode electron gun with maximum transverse velocity spread of 3.19 % is obtained, the beam acceleration voltage is 50 kV, operating current is 5.5 A and the ratio of the transverse velocity to the axial velocity is equal to 1.4. A comprehensive analysis of MIG for 0.42 THz second harmonic gyrotron is presented, and the designed electron gun well satisfies the requirement of the 0.42 THz gyrotron.

The influences of beam quality and Ohmic loss on the beam-wave interaction in a 420 GHz second-harmonic complex-cavity gyrotron

“…By combination with the electron gun simulation in ref. [33] the electron velocity spread and the finite width of the electron beam in the designed MIG (Magnetron Injection Gun) are about 5% and 0.195 mm, respectively. Meanwhile the mode's Ohmic quality factor can be approximated as Q nΩ ≈ (δμ 2 mn /(μ 2 mn − m 2 n )R) −1 (δ is the skin depth, R is the cavity radius, m n is the azimuthal index of the n-th mode, μ mn is the n-th root of the derivative of Bessel function J m ), here the Ohmic quality factor of TE −17.4 in the designed complex cavity is about 75000.…”