Development of a 27.12 MHz radio frequency driven ion source with 3 mTorr operation pressure for neutron generators

An inductively coupled rf plasma ion source has been developed for neutron generators. The ion source configuration has been optimized for low pressure operation. Both 13.56 and 27.12 MHz rf powers have been used to generate hydrogen plasma. Experimental results show that 27.12 MHz operation is more efficient than 13.56 MHz in a low pressure region. The ion source can also be operated in pulsed mode. Current density higher than 30 mA/cm2 can be extracted from a 2-mm-diam aperture at 2 kW rf input power and 3 mTorr operation pressure