Upgrade of RIKEN 10 GHz Electron Cyclotron Resonance Ion Source Using Plasma Cathode Method

Abstract
Beam intensities of highly charged nitrogen, neon, argon and krypton ions from the RIKEN 10 GHz electron cyclotron resonance ion source were measured by applying the so-called plasma cathode method to its first-stage structure. This modification has allowed fairly large enhancement of their output intensities as compared with those obtained with the negatively biased electrode previously reported. In addition, characteristics of stability and lifetime have been greatly improved. Optimum gas pressures in the first and second stages have been lowered by nearly a factor of four. In this method gas mixing is not very effective in further increasing the beam intensities of highly charged light ions, except for krypton ions.