Protective overcoatings on thin-film titanium targets for neutron generators

We have developed a thin-film coating for neutron generator targets that can be loaded with deuterium or tritium at low temperatures (100 °C), and at gas/Ti ratios greater than 1.7. The key to this improvement is the addition of a thin palladium overcoat at the end of the titanium deposition. This overcoat prevents the oxidation of the titanium film, yet still allows loading to take place at low temperatures. A palladium overcoat of just 50–100 Å is sufficient to protect the titanium, while presenting a minimal energy loss to incident ions. We have just begun producing targets using this method, and see the possibility of substantial improvement in neutron generator efficiencies.