| 摘要 |
PROBLEM TO BE SOLVED: To provide an ion source in which a plurality of heated units are provided in a plasma generating container, in which stable thermoelectrons are emitted stably and the operating time of the ion source until exchange of the heated units is extended. SOLUTION: The ion source includes a plasma container which includes an internal space with a conductor face in which gas is supplied and plasma is generated, a pair of thermoelectron emitting elements which are electrically insulated from the plasma container and protrude from the inner wall face of the internal space and emit thermoelectrons to the internal space by current flow, and a power source which makes electric current flow respectively to the pair of thermoelectron emitting elements. The material of the inner wall face exposed to plasma in the plasma container and the material of a portion of the pair of thermoelectron emitting elements which is exposed to the plasma and emits the thermoelectrons are constructed of a material having the same metal as a main component. COPYRIGHT: (C)2009,JPO&INPIT
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