Conceptual design of accelerator driven systems with light ion beams

The superior energy efficiency of light ion beams instead of proton beams for energy production in accelerator driven systems (ADS) is demonstrated. The energy efficiency is characterized by the energy gain calculated as the ratio of the energy released in the target to the energy spent for the beam acceleration. The energy deposited in the target is obtained via Geant4 simulation. A method to calculate the energy spent for the beam acceleration by scaling from the data for a reference beam is presented. The influence of the target structure on the energy efficiency of 0.5 - 4 GeV proton beams and 0.25 1 AGeV light ion beams is studied. The target consists of rods with different composition (metal, oxide, carbide) and different levels of enrichment in order to implement the target with a criticality coefficient keff of 0.96 - 0.97, which ensure safe operation. The influence of the rod dimensions, the coolant and converter on the neutron spectrum and energy released are analysed.