Theoretical study of transverse emittance growth in a gridded electron gun

Theoretical work has been carried out to study the transverse emittance growth in a thermionic gridded electron gun. The potential distribution in the cathode-grid and grid-anode region and the beam emittance growth produced the grid are calculated. The results indicate that emittance growth due to the grid mesh located in front of the cathode is the dominant source compared to other emittance sources such as due to the intrinsic thermal motion. Theoretical results have also been compared with the experimental results and they are in relatively good agreement.