An electron gun driver , comprising a high voltage side and a low voltage side , the high voltage side comprising: a half bridge driver circuit , comprising: a drive circuit configured to generate a grid drive voltage for a grid connection of an electron gun ; and a cutoff circuit configured to generate a grid cutoff voltage for the grid connection of the electron gun ; and a gate driver configured to switch between the grid drive voltage and the grid cutoff voltage ; and a drive controller configured to generate a pulse input to the drive circuit and cutoff circuit and grid switching signals for the gate driver , characterized in that : the drive circuit further comprises: a drive voltage power amplifier configured to provide the grid drive voltage for the half bridge driver circuit , a drive digital to analog converter, DAC, configured to generate a programming voltage to the drive voltage power amplifier , and a drive power switch configured to apply the grid drive voltage to the grid connection ; and the cutoff circuit further comprises: a cutoff voltage power amplifier configured to provide the grid cutoff voltage for the half bridge driver circuit , a cutoff DAC configured to generate a programming voltage to the cutoff voltage power amplifier , and a cutoff power switch configured to apply the cutoff voltage to the grid connection ; and the gate driver is configured to apply grid control signals to the drive power switch and the cutoff power switch . a half bridge driver circuit , comprising: a drive circuit configured to generate a grid drive voltage for a grid connection of an electron gun ; and a cutoff circuit configured to generate a grid cutoff voltage for the grid connection of the electron gun ; and a gate driver configured to switch between the grid drive voltage and the grid cutoff voltage ; and a drive circuit configured to generate a grid drive voltage for a grid connection of an electron gun ; and a cutoff circuit configured to generate a grid cutoff voltage for the grid connection of the electron gun ; and a gate driver configured to switch between the grid drive voltage and the grid cutoff voltage ; and a drive controller configured to generate a pulse input to the drive circuit and cutoff circuit and grid switching signals for the gate driver , characterized in that : the drive circuit further comprises: a drive voltage power amplifier configured to provide the grid drive voltage for the half bridge driver circuit , a drive digital to analog converter, DAC, configured to generate a programming voltage to the drive voltage power amplifier , and a drive power switch configured to apply the grid drive voltage to the grid connection ; and a drive voltage power amplifier configured to provide the grid drive voltage for the half bridge driver circuit , a drive digital to analog converter, DAC, configured to generate a programming voltage to the drive voltage power amplifier , and a drive power switch configured to apply the grid drive voltage to the grid connection ; and the cutoff circuit further comprises: a cutoff voltage power amplifier configured to provide the grid cutoff voltage for the half bridge driver circuit , a cutoff DAC configured to generate a programming voltage to the cutoff voltage power amplifier , and a cutoff power switch configured to apply the cutoff voltage to the grid connection ; and a cutoff voltage power amplifier configured to provide the grid cutoff voltage for the half bridge driver circuit , a cutoff DAC configured to generate a programming voltage to the cutoff voltage power amplifier , and a cutoff power switch configured to apply the cutoff voltage to the grid connection ; and the gate driver is configured to apply grid control signals to the drive power switch and the cutoff power switch . <EOS>