SC accelerator components for light ion linacs

Abstract

SRF related activities are mainly dedicated to two projects. One is connected with the LINAC system of the proposed European Spallation Neutron Source ESS which is supposed to deliver 1.3 GeV H(-) pulses of about 110 mA over 1.2 ms with a repetition rate of 50 Hz for injection into compressor/storage rings. Additionally H(+) pulses of 2.5 ms with the same current should be provided in interlaced operation with a repetition rate of 16.66 Hz. In close cooperation with European partners, selected items for the ESS LINAC are worked on. A superconducting (sc) test module with 5 elliptic cells is available for investigating stability effects i.e. microphonics and Lorentz Force Detuning (LFD) in pulse mode operation. For the medium energy segment spoke type cavities are under investigation. Since May 2001 the realization of a low energy LINAC based on sc Quarter Wave Resonators (QWR) is pursued, which will serve as H(-) and D(-) injector for the cooler synchrotron COSY. For the design an experienced partner in INFN-LNL, Legnaro, Italy, was found and the ALPI heavy ion accelerator was constructed using sc QWR technology. Their resonator structures have to be modified to compensate the disturbing effects of nonsymmetrical fields, which are especially important in light ion acceleration.