Development of Volume Produced Negative Ion Source using a CCRF Discharge

This work shows the development of a volume-produced negative ion source that consists of annular parallel plates driven by a 13.56 MHz capacitively coupled radio frequency in a push-pull configuration. This source shows advantages in controlling plasma conditions by varying the pressure, power, and applied axial magnetic field. It is found that the push-pull configuration allows the plasma potential to remain in the range of 20 to 40 Volts. Conversely, the application of a magnetic field helps serves to augment the production of negative ions in the central hollow part of the annular plate. Further, a plausible explanation to the obtained experimental results is presented.