The design of a novel gun for gyro-amplifiers

In the paper, we designed a novel Magnetic injection gun for gyrotron. Added a coaxial signal input wave-guide into a conventional MIG to complete the electron beam and the signal transmission. The new structure reduces the transverse radius of the gyrotron, predigest the design complexity of the magnetic field and the water cold system. In addition to great deal of simulations, we get the result as follows : the velocity pitch is 1.5, the spread of the beam is less than 5%, the transmission efficiency of TE₀₁ is 98%. The code measurements verified the design.