Speaker
Description
The present status of the authentic FLUKA code will be presented with particular emphasis to developments and features added in the last couple of years.
High-energy FLUKA’s model have been deeply revised in order to improve predictions, and to better match experimental data on the production of intermediate hadronic resonances, data which show a picture rather different from the one usually assumed in hadronization models. Concurrently, hadronic cross section fluctuations are now implemented in the code, improving emitted particle multiplicity distributions, and allowing for the first time to compute quasi-elastic and absorption cross sections directly from the built-in FLUKA Glauber model. A thorough revision and extension of the latter now allows the computation of reliable hadron-nucleus (hA) cross sections up to energies as high as $10^{20}$ eV. Consequently, non-elastic cross sections (quasi-elastic and absorption/particle production ones) have been completely revised and improved in FLUKA.
The interface with DPMJET-3 was deeply modified and streamlined in collaboration with Anatoli Fedynitch, and it is now integrated into the latest Dpmjet version 3.19.3.1. Moreover, thanks to this work, issues at low energies with meson spectra in DPMJET have been improved. Finally, for intranuclear cascading, DPMJET-3 can now use directly the FLUKA hadronic models as an alternative to the original Hadrin model from the 80's.
In the framework of an effort to extend FLUKA to higher energies, the code has been successfully used up to $10^{19}$ eV for high energy cosmic ray problems, both for photon, proton, and ion projectiles.
At the same time, several developments in the sub-GeV - few GeV energy range have improved results when compared with experimental data.
A new model for coherent and incoherent (quasi-elastic) hA interactions has been developed and it is now applied to protons and neutrons up to 200 MeV, with parameters optimized against available experimental data and DWBA calculations taken from JENDL-4 and ENDF/B-VIIIR0. The same approach is now used for all hadrons from 1 GeV to infinity, accounting also for quasi-elastic interactions at high energies, which are now explicitly described and no longer treated as a sub-case of coherent elastic interactions.
Concerning energies and projectiles of relevance for hadron-therapy, several developments in cross sections for very light fragments and in the modified rQMD-2.4 interface significantly improved predictions for light ion beams, in particular 4He beams. Those beams are now in clinical use at HIT, also thanks to the improvement carried out in FLUKA.
The addition of a sophisticated electro-magnetic tracking algorithm, based on the 4th order Runge-Kutta-Gill method, enables the accurate description of charged particle motion in complex, time dependent, fields (eg resonating cavities), even starting from almost zero energy.
Another important addition had been the ability to propagate and let excited nuclei interact. Now nuclei on an excited nuclear level of known/finite mean life, will travel until the decay point, rather than de-excite instantaneously at the interaction point. This has consequences both at low and very high energies.
For all these topics examples will be given assuming the time will be enough.
The major changes in the neutron sector will be described in a companion presentation.