IBA USING A SMALL TANDEM AND A SINGLE-ENDED VANDEGRAAFF

Using an NEC 5SDH-2 tandem and an upgraded KN-4000 single-ended Van de Graaff machine we are investigating the depth profiles of 1,2H, 4He and 6,7Li which have been implanted or dispersed into silicon wafers, SiO2/Si, SiO2/magnetic bubble garnet, soda-lime glass and stainless steel. The tandem is used to generate an 8 MeV 16O beam for ERD measurements of these light elements and also a 15N4+ beam for profiling hydrogen by means of the 1H(15N, αγ)12C reaction. The Van de Graaff has a maximum terminal voltage of 4.75 MV and accelerates 15N2+ ions for 1H profiling and 3He+ ions for highly sensitive 2H measurements by means of the 2H(3He, pα) reaction. An RBS investigation is running instead of PIXE experiments which have been terminated some years ago. We are using two types of homemade cold-cathode Penning-type ion source (PIG). The one has a side-extraction design for the tandem, and the other is an end-extraction source for the Van de Graaff. Owing to very low gas consumption, both sources are suitable for generation of ions of expensive isotopes such as 3He and 15N. We will report the experience with IBA using both types of electrostatic machines. © 1990.