Study of a thick target surface ionizer at INS

Abstract A surface-ionization ion source for the use of a thick target has been studied by an isotope separator on-line at INS using the 40 Ca(p,2pn) 38 K reaction. The ionization efficiency and release time were measured for CaC 2 , CaO and CaF 2 targets. The measured efficiency turned out to be about 20% both for tantalum and platinum surface ionizers. The release time was also deduced for each target at various values of temperature by measuring time distributions of the extracted radioactivity after bombarding the target for a short time.