INVESTIGATION OF A NORMAL CONDUCTING 175 MHZ LINAC DESIGN FOR IFMIF

The work for the project study of an International Fu-sion Material Irradiation Facility (IFMIF) has been con-tinued. The linac part of the facility has to provide a 40 MeV, 125 mA D+ beam for the homogenous irradiation of a Li target to produce very high neutron fluxes for fu-sion chamber wall material tests. The linac consists of a Radio Frequency Quadrupole (RFQ) accelerator followed by a Drift Tube Linac (DTL). To different rf structures have been investigated for the DTL: the well known Al-varez type and the IH-type, both operating successfully at several large laboratories. Moderate rf power losses in the structure has been one main aspect in the design with re-spect to the required cw operation. Results of multiparti-cle beam dynamics simulations demonstrate the capability of each structure to handle the very high currents without particle losses and at moderate emittance growth. While the Alvarez DTL design shows less emittance growth with and without errors, the IH-DTL is attractive with respect to its compactness and mechanical robustness [1].