Effect of plasma electrode position on the beam intensity of heavy ions from a RIKEN 18 GHz electron cyclotron resonance ion source

To investigate the effect of the plasma electrode position on the beam intensity, we measured the beam intensity of Ar ions, with various charge states as a function of the electrode position. In this experiment, we observed that the beam intensity of highly charged Ar ions is strongly dependent on the electrode position and that there is the suitable position to maximize the beam intensity. The optimum position varies with the charge state of ions. The beam intensity of 1.3 mA for Ar8+ was obtained at the optimum plasma electrode position. (C) 2002 American Institute of Physics.