Study of argon additive in a beam injection type negative ion source using VUV emission spectroscopy

Abstract

Effects of Ar addition are studied by using a beam injection type negative ion source. With adding Ar, I H À increases at low base H 2 pressure. At high base H 2 pressure, however, I H À decreases. VUV emission intensities also decrease at high base pressure. In other words, Ar addition is adverse effect for production of H 2 (vW). Therefore, decrease in I H À is caused by decrease in H 2 (vW). In D 2 plasmas, variation patterns of plasma parameters and VUV intensities by Ar addition are nearly the same as ones in H 2 plasmas. Even in low base pressure, however, enhancement of I D À is not observed. D 2005 Published by Elsevier B.V.