Proposal of sharing of CW superconducting linac with ILC injector and photon light source

We propose sharing of the 6-GeV class CW superconducting (SC) linac with ILC and X-ray light source. Although the main linac of ILC is operated at 1 ms pulse at 5 Hz, CW operation can be better solution for the positron source to avoid the thermal loading problem of the positron target. In this scheme, CW linac accelerates not only the positron beam but the GeV class driven electron beam for the conventional positron source. The stretch of the pulse duration is limited in 64 ms to ensure the damping time the at the damping ring. Thanks to the low average current of the beams of ILC and the 136 ms margin at 5 Hz, it is possible to simultaneously operate the high quality electron beams for brilliant light source, such as ERL and CW-XFEL. (author)