TRIUMF, Vancouver
ISAC is the TRIUMF facility for the production and post acceleration of Rare Isotope Beams (RIBs). The post acceleration section includes two normal conducting linacs, an RFQ injector and a variable energy IH-DTL, and a superconducting linac composed of five cryomodules each containing four quarter wave bulk niobium resonators. All three machines operate CW. The RFQ and DTL deliver beam since 2000 to a medium energy area with energies variable between 150 keV/u and 1.8 MeV/u. The superconducting linac, with an effective voltage of 20 MV started delivering in 2007 with performances exceeding design specifications reaching final energies up to 11 MeV/u for lighter particles. The linac gradients show no average degradation in performance. Well established operational and tuning procedures allow reliable operations. Schemes have been developed to effectively deliver the very low intensity (as low as few hundred particles per second) radioactive ion beams. The superconducting linac will be upgraded with the addition of twenty more cavities (boosting the acceleration voltage to 40 MV) by the end of 2009 making the reliability quest more challenging. In this paper we present past, present and planned operations with the ISAC linacs.
TRIUMF, Vancouver
At the ISAC facility in TRIUMF radioactive ion beams (RIB) are produced using the ISOL method and post accelerated. The post accelerator chain consists of a radio frequency quadrupole (RFQ) injector followed by a drift tube linac (DTL) that accelerates the ions from 150 keV/u up to 1.8 MeV/u. A further stage of acceleration is achieved using a superconducting linac where the beam is injected using the DTL and the energy boosted with 20 MV of acceleration voltage (increased to 40MV by the end of 2009). The possibility of decelerating the beam maintaining good beam quality using the DTL is investigated based on experimenters request to reach energies lower than 150 keV/u. The beam dynamics simulation using the LANA code are compared with on line measurements. In this paper we will report the results of the investigation that aims to establish the lowest energy we can deliver in the post accelerator section of the ISAC facility.