A proposal to produce a triton beam using a caesium sputter source

Abstract

Until recently most accelerator laboratories have avoided accelerating tritons because of the excessive activity involved in handling large volumes of tritium. The caesium sputter source utilizes tritium as titanium titride in a sputter cone which releases gas by sputtering the cone with caesium ions at a rate necessary to produce the required negative ion beam. The efforts at McMaster have been directed in four main areas : reliability of source components, cone loading, contamination problems and safety. Tests on the reliability of source components indicate that a lifetime of 1 000 hours of maintenance free operation is not unreasonable. Procedures have been developed for loading the titanium inserts used in sputter cones with deuterium. These results are not expected to differ substantially for tritium. Pumping and collection of released tritium will be accomplished using a high speed titanium getter pump in conjunction with a small oil diffusion pump. The tritium will be differentially pumped to avoid contamination of the existing large oil diffusion pumps on our ion source chamber. The main areas of safety being studied are the use of a residual gas analyser for vacuum monitoring of released gases and a high sensitivity tritium gas monitor for air monitoring. The program at McMaster should allow us to produce triton beams during the summer of 1977.