Stability study of all-permanent-magnet electron cyclotron resonance ion source

Yoshida, Kenichi; Nara, Takayuki; Saito, Yuichi; Yokota, Wataru

The beam intensity fluctuation was investigated using an electron cyclotron resonance ion source (ECRIS) of an all-permanent-magnet type under development for high stability of the beam intensity. While the source has achieved the stability better than 3.2% with strict regulation of the coolant temperature change within 0.1C, the intensity varies strongly depending on the temperature of the plasma chamber coolant when it is changed intentionally. The influence of the temperature on chamber expansion, magnetic field strength and vacuum was measured or estimated in detail. The result shows that the slight change in vacuum has significant influence on the intensity.