Simulation and test of a thermioic hairpin source DC electron beam gun

A hairpin source electron gun was simulated and tested for its emission characteristics. We calculated beam emittance 4.3 π-mm-mR and average current density 5.80 A/cm2 which corresponds to power density 5.80 × 104 W/cm2 with 0.9 mm of beam waist diameter at 113 mm in the post anode region. The simulation and test results were found in agreement at 10 kV of acceleration potential. We also calculated the variation of current density and emittance with acceleration potential up to the saturation limit of the gun (100 kV). The gun is useful for electron optical devices, electron accelerators and deep weld joints of refractory metals.