The effect of an analyzed deuterium ion beam on the lifetime of TiT targets used at the fast neutron therapy facility (DT, 14 MeV) Hamburg-Eppendorf.

Report on experiments performed with mixed or analyzed deuterium ion beams incident on TiT targets at the neutron therapy facility Hamburg-Eppendorf. Bombarding a TiT target area with all separated atomic and molecular ions of an analyzed deuterium ion beam at different beam spots, the "initial" half-life of the used tritium target increases with a factor of more than three as against the half-life obtained with a mixed deuterium ion beam at a single beam spot. In this case, the effective target current is not reduced and in the same order as that for a mixed deuterium ion beam. Using the atomic deuterons only, the increase of the "initial" half-life is far longer yet, but the loss in target current is about 50% dependent on the reduction of molecular deuterium ions. These facts are most important for the economy of this type of neutron therapy facilities clinical work.