New developments in FLUKA modeling hadronic and EM interactions

Abstract Recent developments,in the FLUKA code are outlined. Charged particle energy losses below an (arbitrary) explicit ray production threshold are obtained from a sophisticated statistical approach which includes “close” collisions, plus a two-oscillators model for “distant” collisions; comparison with experimental energy loss strag- gling are presented. Several improvements took place in the PEANUT hadronic generator, among which the in- clusion of new processes mainly triggered by the needs of the ICARUS experiment. Standard and exotic nucleon decay channels are now available with full simulation of the intranuclear effects and their influence on the final state configuration. Negative muon capture at rest is also described, and the implementation of neutrino nuclear interactions, with particular care in the treatment of nuclear Fermi motion and hadron formation time effects is in progress. The calculation of residual nuclei has been refined and extended also to neutron interactions below 20 MeV, including fission, with suitable modifications to the multigroup library. A few only of these topics are presented in the text, because of space reasons. Other details about some of the FLUKA applications can be found in a companion,paper at this conference [1]. 1 Ionization energy losses Figure 1: Experimental [14] and calculated energy loss distributionsfor 2 GeV/c positrons ( left) and protons(right)