Development of a low-energy oxygen 14 ion beam (abstract).

At the 88 Inch Cyclotron at the Lawrence Berkeley National Laboratory (LBNL) we have developed an intense (3 x 10[sup 7] pps), low-energy [sup 14]0 ion beam for precision tests of the standard model. The 70 s half-life of [sup 14]O requires on-line production of the isotope. [sup 14]O is produced in the form of [sup 12]C[sup 14]O in a high-temperature carbon aerogel target using a 20 MeV ³He beam from the LBNL 88 Inch Cyclotron via the reaction [sup 12]C(³He, n)[sup 14]O. In order to minimize the background radiation for the experiments, the [sup 14]O atoms must be separated from the other radioactive isotopes produced in the carbon target. For this purpose, we have developed an experimental setup including the target, transfer line, the electron cyclotron resonance ion source IRIS, and a low-energy ion beam transport line. The major components of the setup are described. The release and transport efficiency for the CO molecules from the target through the transfer line was measured for various target temperatures. The on-line and off-line ion source efficiencies for radioactive and stable oxygen beams are presented. [ABSTRACT FROM AUTHOR]