A CW superconducting linac as the proton driver for a medium baseline neutrino beam in China

In a long-term planning for neutrino experiments in China, a medium baseline neutrino beam is proposed which uses a continue wave (CW) superconducting linac of 15 MW in beam power as the proton driver. The linac will be based on the technologies which are under development by the China-ADS project, namely it is also composed of a 3.2 MeV normal conducting RFQ and five different types of superconducting cavities. However, the design philosophy is quite different from the China-ADS linac because of the much weaker requirement on reliability here. The nominal design energy and current are 1.5 GeV and 10 mA, respectively. The general considerations and preliminary results on the physics design will be presented here. In addition, the alternative designs such as 2.0 GeV and 2.5 GeV, which may be required by the general design, can be easily extended from the nominal one. (authors)