Field-emission ion source with spiral shaped filament heater

摘要

The field-emission-type ion source according to the present invention comprises an emitter tip, a heater, a reservoir which stores material to be ionized, an extracting electrode situated at the front end of the emitter tip, and a coating-layer which is refractory and anti-reactive with the material to be ionized and which is coated on at least the heater of the emitter tip and heater, in order to prevent their reactions with the material to be ionized.