The relative detection efficiency of funnelled channel electron multipliers for low energy protons and argon ions

Abstract

A determination has been made of the efficiency with which certain commercially available channel electron multipliers detect H+ and Ar+ ions. The three multipliers tested were Bendix types 4013 and 4039, which have 3 mm and 10 mm diameter funnels respectively, and a Mullard type B419 BL which has a 10 mm diameter funnel. The efficiency shows saturation for ions with energy above a few kilovolts and is relatively constant across the whole surface of the 10 mm funnels. The particular 3 mm funnel tested shows an energy dependent sensitivity across its surface.