A Compact Proton Injector Based on the Electron Cyclotron Resonance

A proton injector based on electron cyclotron resonance is described. It can operate for a long time without the need to apply a high voltage to its power-supply equipment without providing a coolant. For a supplied microwave power of ~150 W, the extracted ion current in a continuous mode was 17 mA at an energy of 45 keV and a proton content of 68%. The proton-beam divergence was 0.4°, and the normalized rms emittance was e = 0.13π mm mrad.