BEAM STABILITY ANALYSIS FOR ADS

摘要

In an Accelerator Driven System (ADS) aimed for the transmutation of nuclear waste, super-criticality accidents are eliminated but are replaced instead by over-power transients. Thus an important challenge for designing an ADS-Reactor facility is to demonstrate that the multiplicity of the target cannot change significantly due to some perturbations. This requires understanding the underlying physics of the spallation process, but also of the collective effects such as the space charge effects that tend to modify the final beam distribution on the target. As part of these investigations, space charge simulations of the KURRI scaling FFAG accelerator in Japan have been undertaken, using a newly implemented module in the tracking code Zgoubi, that allows the computation of self fields. A perturbative approach is used to investigate the beam stability. This is followed by MCNP6 simulations to determine the variation of the spallation induced neutrons that will drive the sub-critical reactor assembly.