CERN Accelerating science

Article
Title	Cold Test Results of the ISAC-II Medium Beta High Gradient Cryomodule
Author(s)	Laxdal, R E ; Bylinskii, Y ; Clark, G S ; Fong, K ; Mitra, A K ; Poirier, R L ; Rawnsley, B ; Ries, T ; Sekatchev, I ; Stanford, G ; Zvyagintsev, V
Affiliation	(TRIUMF, Vancouver)
Publication	2004
In:	22nd International Linear Accelerator Conference, Lubeck, Germany, 16 - 20 Aug 2004, pp.222
Subject category	Accelerators and Storage Rings
Abstract	Many proposals (RIA, Eurisol, ISAC-II) are emerging for a new generation of high gradient heavy ion accelerators. The ISAC-II medium beta cryomodule represents the first realized application that encorporates many new techniques to improve the performance over machines presently being used for beam delivery. The machine lattice, compatible with multi-charge acceleration, uses high field (9T) superconducting solenoids with bucking coils for active fringe field compensation. The bulk niobium quarter wave medium beta cavity produces 6 MV/m over an effective length of 18cm with a peak surface field of  30 MV/m. TRIUMF has developed a mechanical tuner capable of both coarse (kHz) and fine (Hz) frequency adjustments of the cavity. The demonstrated tuner resolution is better than 0.1 μm (0.6 Hz). A new rf coupling loop has been developed that operates at 200 Watts forward power with less than 0.5 Watt of power being added to the helium load. Cold alignment in ISAC-II has been done with rf pick-ups using a stretched wire technique. Finally all cryomodule and testing has been done in a clean environment. The alignment cryogenic, solenoid and rf performance will be presented.