• R.E. Laxdal, C.D. Beard, R.J. Dawson, K. Fong, A. Grassellino, M.P. Laverty, D. Longuevergne, M. Marchetto, A.K. Mitra, T.C. Ries, I. Sekachev, Q. Zheng, V. Zvyagintsev
  TRIUMF, Vancouver

The ISAC-II Phase II expansion includes the addition of 20 new quarter wave resonators in three cryomodules to double the energy gain of the ISAC-II superconducting linac. The rf cavities are produced in Canada. The talk will concentrate on the beam commissioning (scheduled for March 2010) and early operating experience.

• M.P. Laverty, K. Fong, R.E. Laxdal, Q. Zheng
  TRIUMF, Vancouver
• G. Dennison
  UBC & TRIUMF, Vancouver, British Columbia

The rf control system for the twenty 141 MHz TRIUMF quarter wave superconducting cavities is a hybrid analogue/digital design. It is based in part on an earlier design developed for the 106MHz 1/4 wave superconducting cavities of the ISACII linac. This design has undergone several iterations in the course of its development. In the current version, a value-engineering approach was used to reduce the cost and simplify the hardware. The result is a single C-size VXI module that incorporates all the required low-level rf functions - amplitude/phase control, tuning control, and control of the rf coupler. It accomplishes these functions at a substantially lower cost than the previous two-module solution. It also includes support for field upgrade of the DSP/PLD hardware and firmware. Some early test results of the system operating in the linac are outlined, and conclusions are summarized.