Superconducting quarter wave resonator as a beam phase detector for IUAC heavy ion linac

The superconducting heavy ion linac booster consists of three identical accelerating modules of linac along with the super-buncher and re-buncher cryostat. Each accelerating modules of linac consists of eight superconducting (SC) niobium quarter wave resonators (QWRs) which need to be independently phase locked with respect to master oscillator. The reference phase of each QWR adjusted for optimum acceleration efficiency. The SC linac energy tuning procedure being followed at IUAC utilises gold foil scattering set up in a scattering chamber at the exit of the accelerating modules along with the suitable surface barrier (SB) detector system for energy and time measurement. In an alternate development, a new technique based on the superconducting QWR operating in a beam bunch phase detection mode is developed and tested along with the existing linac tuning technique using SB detectors. Both the techniques are used to derive a full set of phase tuning parameters for beam acceleration during a test run with Si Beam. Verification of the superconducting phase detector is accomplished with the measurements from surface barrier detector. The new technique is not so sensitive to the changing beam current, is independent of beam steering/focussing and has the capability to quickly tune the complete linac consisting of 24 QWRs. The developed new technique has the potential to auto tune the linac set up procedure. The measurement techniques along with developments, results and future plan will be presented in this paper. (author)