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

Abstract

In November of 1998, the ISAC radioactive beam facility at TRIUMF started delivering on-line isotope separated radioactive beams to experiments. A surface ionization source developed for ISAC has been used to commission the mass separator and beam transport systems and is providing radioactive beams to the first generation of ISAC experiments. The ion source is integral with the radioactive beam production target and is designed to be simple, radiation hard, inexpensive, and easily exchanged by remote-handling techniques. The ion source and its extraction column are suspended at the bottom of ∼2 m of steel shielding incorporated in the target module. The module is suspended in a vacuum tank with primary and secondary vacuum systems. All services for the target/ion source and beam extraction system are ducted through the module shielding. The first sets of beam transport elements and beam diagnostic devices are similarly suspended in vacuum at the bottom of two additional shielded modules. Ion beam characteristics can be routinely 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 diagnostics devices are capable of resolving beam signals down to the 10 pA range.

In-Trap Spectroscopy of Charge-Bred Radioactive Ions

“…The Isotope Separator and Accelerator (ISAC) facility [20,21] at TRIUMF in Vancouver, Canada, employs a high-intensity (up to 100 µA) beam of 500 MeV protons to produce RIBs using the isotope separation on-line (ISOL) technique [8,22]. ISAC is currently able to provide a wide variety of RIBs through the use of several different production target and ion-source combinations [23], including the recent use of uranium-carbide (U C x ) targets [23].…”

Resonant Ionization Laser Ion Source Project at TRIUMF

“…The principal scheme of the laser ion source system is depicted in Figure 1. The distance from the on-line lasers to the target ion source is approximately 20 m. It is planned to use the current surface ionisation source [17] directly and adding resonant laser ionisation to the surface ionisation. The surface ioniser/transfer tube connects the target to the ion extraction lens.…”

“…A brief description of the system can be found in the literature [14]. This duplication of the on-line system [17] ensures ready transfer of results to on-line operation.…”

High intensity targets for ISOL, historical and practical perspectives

“…The TRIUMF-ISAC RIB facility was designed for maximum driver beam intensities of 100 lA of 500 MeV protons on target [31]. Initial beam delivery started in 1998 using 1-3 lA proton intensities on standard target containers [32,33]. In 1999, a Nb foil target was operated with a 10 lA proton beam and by 2000 both Nb and Ta foil targets were operated with 20 lA proton intensities; a target of SiC powder pressed into pellets was also operated at 10 lA.…”