Design, simulation and analysis of beam optics and solenoid of high-power gun for RF power source

Abstract A 5.5-Megawatt thermionic electron gun and solenoid have been designed, simulated and analyzed for the use of ultra-high radio frequency (P-band) amplifier for proton beam acceleration. The gun produced space charge limited current more than 50 A at 110 kV (beam perveance , 1.37  μ P) acceleration potential. The maximum surface gradient less than 61 kV/cm has been achieved to avoid any breakdown due to high voltage operation. An average cathode loading of 1.30 A/cm 2 has been achieved that is agreeable with the theoretical limitations. Beam optics has been designed in EGUN & DGUN (2-dimensional) codes respectively, for fast parametrization and optimization of the electrodes and then cross verified in CST (3-dimensional) software that are found in good agreement. A solenoid has been designed in POISSON (2-dimensional) software and then also in CST for a constant flow and transmission of the beam downstream. A laminar beam with ripple rate 3.5% (on average) has successfully been achieved with beam fill factor less than 0.660. Simulations results show that a triple code design scheme is effective and has an excellent beam transport characteristic. The results anticipate enhanced life and stability of the gun due to low surface gradient and cathode loading.