Design optimization of the proposed ISAC-2 project at TRIUMF

A radioactive ion beam facility, ISAC, is presently under construction at TRIUMF The post-accelerator takes ions of A/q⩽30 from 2 keV/u to energies up to 1.5 MeV/u. For the next five year plan, it is intended to increase the final energy above the Coulomb barrier (roughly 6.5 MeV/u) and broaden the mass range up to roughly A=150. The ISAC-2 proposal utilizes the existing RFQ, and a new IH drift tube linac to reach a new stripping energy of 0.4 MeV/u. A post-stripper superconducting linac will accelerate ions with 3⩽A/q⩽7 to 6.5 MeV/u for the heaviest ions and to more than twice this value for the lightest ions. This paper documents the optimization of the ISAC-2 linac design