18F intense spot positron source for spin polarized positron beam

An intense positron source, 18F, with a half life of 110 min has been developed for spin polarized positron beams. The 18 . 18 18 .18 radioactive F ca. 30 GBq is produced in 1 ml O-water target via the O p,n F reaction with a 14 MeV proton beam at a current of 20 mA in the AVF cyclotron vault. An irradiated 18O-water is transferred to an experimental vault downstairs to be trapped and placed just in front of the moderator. The electrodeposition method was used to collect and fix 18F on a small spot from 18O-water. Recovery of 18F on the graphite cylinder of 5 mm B is 69% and 35% for 3 mm B cylinder, respectively. q1999 Published by Elsevier Science B.V. All rights reserved.