The boride surface modification of rare-emitter, the emitter and the boride surface modifying devic

PROBLEM TO BE SOLVED : To provide a surface reforming method for a rare earth boride emitter that can easily reform a B terminal surface to a rare earth terminal surface, a surface reformed rare earth boride emitter which is reformed to have a rare earth terminal surface and enhanced in electron discharging capability, and a surface reforming device and electron beam source device.SOLUTION : In a surface reforming method for a rare earth boride emitter, a voltage of 200 V or more is applied to nanofiber formed of rare earth boride for a fixed time to extract rare earth elements from the inside of the nanofiber to the surface thereof, thereby reforming the surface of the nanofiber to a rare earth element terminal surface.SELECTED DRAWING : Figure 6