Multilayered target for the production of {sup 15}O secondary radioactive beams

The authors have used the Jet Vapor Deposition (JVD) method to produce a target with 350 layers of Ti{sup 15}N backed by carbon (1,000 A each). And 7.6 MeV proton beams (< 55 {mu} Amps) from the Louvain-La-Neuve CYCLON30, to produce secondary radioactive {sup 15}O beams using the {sup 15}N(p,n){sup 15}O reaction. The {sup 15}O nuclei are stopped in the carbon layers and produce CO molecules that are readily extracted from the hot foil and collected in a cryogenic getter for counting of the {beta}{sup +} decay. The authors measure an extraction efficiency of approximately 15%, limited by target meltdown. Hence they project a production of {sup 15}O secondary radioactive beams at least a factor of 100 better than could be obtained with the use of the {sup 12}C({alpha},n){sup 15}O reaction. They continue their effort to improve target resilience and better extraction efficiency, as well as produce thicker foils with approximately 5,000 layers (1mm).