Production of radioactive beams of francium

✍ Scribed by G. Stancari; S. Veronesi; L. Corradi; S.N. Atutov; R. Calabrese; A. Dainelli; E. Mariotti; L. Moi; S. Sanguinetti; L. Tomassetti

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 284 KB
• Volume: 557
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2005.11.193

✦ Synopsis

We describe the production of francium beams from the fusion-evaporation reaction 197 Auð 18 O; knÞ 215-k Fr generated by a $100 MeV 18 O 6þ beam on a thick gold target. The physics of the production process is discussed, together with estimates of expected production rates. The production target is heated to $1200 K and kept at a potential of þ3 kV to enhance Fr diffusion and surface desorption, and to accelerate surface-ionized ions. Details are given on its design and construction. The performance of the target is measured as a function of primary beam energy and flux, target temperature and extraction voltage. Average production rates are 0:7 Â 10 6 ions=s for 210 Fr with a primary beam flux of 10 12 particles=s, with peaks of 2 Â 10 6 ions=s. From these measurements, information on the efficiency of the release processes is inferred.