2013 Volume 8 Pages 2401087
In order to expand the applied range of the heavy ion beam probe measurement on LHD, it is important to increase the probing beam current. A method of increasing the current is the improvement of charge exchange efficiency of a gas cell. The experiments were carried out on a tandem accelerator at Kobe University, 5SDH-2, because various conditions of experiments can be selected for gas species, gas pressure, and ion energy. Charge fractions of negative ion, neutral atom and the positive ions were measured by a micro channel plate or Faraday cup. Dependence of the fractions of Au−, Au0, Au+ and Au2+ on gas thickness was measured. Results were compared with prior calculations, and a solution of rate equations. The cross sections for ionizing and electron capture were calculated, and some cross sections were obtained from experiments. The dependence of charge fractions for Au0, Au+ and Au2+ on the gas thickness was well presented.