Development of an intense O-15 radioactive ion beam using low energy protons

The production of copious quantities of 15O, (half-life = 122.2 s) for astrophysical applications has been a source of concern at TRIUMF and ISAC for some time. An 15O beam is needed for two experiments (15O(α,γ)19 Ne and 15O(6Li,d)19Ne) at ISAC. The beam flux required for these experiments is extremely high, (between 109 and 101115O/s) and thus high efficiencies at all steps in the process will be required. Difficulties arise due to the fact that oxygen is very reactive chemically and thus is difficult to extract from a thick spallation target. The possibility of using one of the small cyclotrons on site (TR13, CP42 or TR30) for the production of this isotope (15O) has been discussed. This production approach will involve the use of low energy protons to interact with a nitrogen gas target via the 15N(p,n)15O reaction, which is accessible with attainable particle energies using these cyclotrons. Preliminary results using the 14N(d,n)15O reaction as a model for the 15N(p,n)15O reaction have been obtained and is presented describing the appropriate on-line chemistry to separate, trap, purify and transfer the 15O. The 15O will be converted to the preferred chemical form of C15O which will be available for introduction into an ECR ion source for the production of the high intensity 15O ion beam at ISAC