Issues to be verified by IFMIF prototype accelerator for engineering validation

The validation of the accelerator technology providing the 250 mA/40 MeV continuous-wave (CW) deuteron beam with the required quality is a key issue to realize the international fusion materials irradiation facility (IFMIF). As the difficulty of high current accelerator generally comes from the low energy section due to space-charge effects, a prototype test of such a part is planned in the next development phase. The optimal choice of the prototype consists of a full-scale injector, a full-modelled radiofrequency quadrupole, and a short drift tube linear accelerator associated with a beam diagnostics/dump. Through prototype tests, the stable control of the CW accelerator at the various operational conditions will be addressed, and the technical risks of IFMIF accelerator construction can be significantly reduced.