Finite element analysis of beam optics, gun envelope and magnetic of megawatt electron gun of microwave power source

We present the beam & gun envelopes, and magnet system design, simulation, and test of a 5.5-MW electron gun of microwave power source for the use of proton accelerator in neutron spallation source. The maximum surface gradient of the beam and gun envelopes are 5.8 kV/mm & 1.65 kV/mm, respectively. The beam perveance is 1.39 AV-3/2(μP) at 110 kV beam voltage. The magnet system transports the beam with low scalloping parameter of 2.7% with laminar flow downstream. The gun faced no structural change under the operational temperature of 970 Co. The simulations (2D & 3D), and test results are in good agreement. The beam characteristics fully matches the interaction parameters of the power source of a proton accelerator. •Comprehensive analyses of the complete gun and magnet system of the RF power source.•Crossed check technique using 2D &3D softwares for precision and authenticity of the results.•Reduced surface gradient, cathode loading and beam scalloping for smooth operation & life of the klystron.