Updated simulation for the nuclear scattering loss estimation at the RCS injection area

We have updated our simulation for a more realistic beam loss estimation at the RCS(rapid cycling synchrotron) injection area of J-PARC (Japan proton accelerator research complex). At the injection area, the beam loss caused by the nuclear scattering together with the multiple Coulomb scattering in the charge-exchange foil is the dominant one. A precise estimation of the beam loss can give direct feedback for a smooth operation strategy of RCS towards its goal of a 1MW class machine. The simulation code GEANT3 to take into account the scattering part and the realistic space charge simulation code SIMPSONS were used together for the present purpose. A precise loss together with the loss point identification can thus be obtained from the present method. We are in a stage of making the model more intelligent mainly concerning the CPU time when handling with relatively large number of macro particles for very precise calculation and will present here the interim report.