TRIUMF, Vancouver
PAVAC, Richmond, B.C.
The ISAC-II superconducting heavy ion linac, commissioned in 2006, consists of twenty quarter wave cavities housed in five cryomodules. An upgrade of the linac is ongoing that will see the addition of twenty more quarter wave cavities in three cryomodules by the end of 2009. The status of the upgrade will be reported.
University of Pennsylvania, Philadelphia, Pennsylvania
TRIUMF, Vancouver
The quality factor of superconducting radio-frequency niobium cavities decreases with the applied RF field in the medium field range. The medium field Q-slope effect has been investigated by many authors but models, most commonly including thermal feedback, do not fully explain experimental evidence. In this contribution we analyze medium field Q-slope data measured on ISAC-II low beta quarter wave cavities at 4.2K and 2K. The data is compared with a model that, in addition to thermal feedback of the surface temperature, takes into account the reduction of the critical temperature with the applied magnetic field. This hypothesis is tested adding two surface heaters on the LHe side of the cavity in the high magnetic field region and obtaining Q-curves at different heater power levels. The temperature increase of the RF surface due to the heater power is directly measured using a test niobium chamber. A model to explain the experimental results is presented with conclusions concerning the thermal feedback mechanism and on the relationship between the critical temperature field dependence and the Q-slope.
TRIUMF, Vancouver
Solid state amplifiers are being used for linear accelerators at TRIUMF which are either being upgraded or under development. The Radioactive Ion Beam (RIB) facility at ISAC II which is being upgraded with additional 20 quarter wave superconducting bulk niobium cavities will employ twenty 141 MHz solid state amplifiers. A 650 MHz solid state amplifier for electron gun development and an 1.3 GHz solid state amplifier for characterization of an elliptical superconducting niobium cavity are being used for the 50 MeV electron linac being planned at TRIUMF.
TRIUMF, Vancouver
TRIUMF, in collaboration with university partners, proposes to construct a megawatt-class electron linear accelerator (e-linac) as a driver for U(γ,f) with rates up to 1013−1014 fissions/sec for Rare Isotope Beams (RIB) for nuclear structure and astrophysics, and 9Be(γ,p)8Li for materials science. The emphasis would be on neutron-rich species. The 50 MeV, 10 mA, c.w. linac is based on TTF superconducting radiofrequency technology at 1.3 GHz & 2K. Many of the major sub-system components have been identified; where possible existing designs will be adopted. The first stage of the project, a 25 MeV, 5 mA, c.w. linac matching the isotope production target power-handling capability in the next five-year plan, is to be completed in 2013. The injector cryomodule (ICM)development, which is being fast tracked, is the subject of a scientific collaboration between TRIUMF and the VECC laboratory in Kolkata, India. The paper gives an overview of the accelerator design progress with emphasis on the ICM.