Generation of high purity CW proton beams from microwave driven sources

We describe a technique we have developed to significantly increase the proton fraction extracted from high pressure (mTorr) electron cyclotron resonance (ECR) sources of the type developed by Chalk River Laboratories (CRL)[1]. Specifically, this proton enhancement is achieved by the addition of environmentally benign additives (H₂ O being the most effective) to the plasma, in molecular concentrations of the order of 1%. Typically, operating under non-resonant source conditions, this technique will enhance the proton fraction from about 75% to greater than 95% for a power input of 700 W at 2.45 GHz. Similar results are achieved for deuteron beams. We believe this technique is capable of similar results in arc-discharge (bucket) sources, Penning sources and any other gas discharge sources, under suitable conditions