Commissioning and initial operation of a radioactive beam ion source at ISAC

In November of 1998, the ISAC radioactive beam facility at TRIUMF started d elivering on-line isotope separated radioactive beams to experiments. A sur face ionization source developed for ISAC has been used to commission the m ass separator and beam transport systems and is providing radioactive beams to the first generation of ISAC experiments. The ion source is integral wi th the radioactive beam production target and is designed to be simple, rad iation hard, inexpensive, and easily exchanged by remote-handling technique s. The ion source and its extraction column are suspended at the bottom of similar to 2 m of steel shielding incorporated in the target module. The mo dule is suspended in a vacuum tank with primary and secondary vacuum system s. All services for the target/ion source and beam extraction system are du cted through the module shielding. The first sets of beam transport element s and beam diagnostic devices are similarly suspended in vacuum at the bott om of two additional shielded modules. Ion beam characteristics can be rout inely monitored during on-line operation by a system of Faraday cups, wire scanners, "harp" monitors, and a novel emittance measurement apparatus that can measure beam emittance in both horizontal and vertical planes. The dia gnostics devices are capable of resolving beam signals down to the 10 pA ra nge. (C) 2000 American Institute of Physics. [S0034-6748(00)64102-3].