| Popis: |
For the on-line production of a 14O+ ion beam, an integrated target—transfer line ion source system is now under development at LBNL. 14O is produced in the form of CO in a high temperature carbon target using a 20 MeV 3He beam from the LBNL 88″ Cyclotron via the reaction 12C(3He,n)14O. The neutral radioactive CO molecules diffuse through an 8 m room temperature stainless steel line from the target chamber into a cusp ion source. The molecules are dissociated, ionized and extracted at energies of 20 to 30 keV and mass separated with a double focusing bending magnet. The different 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 ion beam transport efficiencies and the off-line ion source efficiencies for Ar, O2 and CO are presented. Ionization efficiencies of 28% for Ar+, 1% for CO, 0.7% for O+, 0.33 for C+ have been measured. |
