A Low Background Semiconductor Counter Telescope for Neutron Reaction Studies

A telescope system is described, in which coincidence or anticoincidence of associated alpha particle pulses from the H3(d,n)He4 reaction with pulses produced in the counters is required in order to reduce the background in investigations of 14 MeV neutron induced reactions. By using current pulse transformers with surface barrier semiconductor counters and fast electronics, coincidence resolving time between neutron induced pulses in the counters and associated alpha particle pulses of 1.6 ns is obtained, and the background is reduced by an order of magnitude. The same method may be employed for studies using lithium-drifted germanium counters, both with 14 MeV neutrons and neutrons produced in the H2(d,n)He3 reaction.