Development of remote control and monitoring system for the FE gun in HVEM.

This paper describes a control and monitoring system for the field emission (FE) gun in the high-voltage electron microscope (HVEM), where the whole FE gun system is located inside a pressure vessel and is floated on a high voltage of 1 MV. The operating condition of the FE gun system is controlled and monitored mainly by a bi-directional communication system between ground and high potential through optical fibres. A mechanical driving system by combination of insulator rods and stepping motors is partially used as a control system for FE gun operation.