Electronuclear Interactions in FLUKA

                             Pavel Degtiarenko
                               Jefferson Lab

Abstract:
The presentation will discuss simulating radiation environment at high energy
electron accelerators, including calculations of target source terms and thin
target activation. One of the real-life examples important at JLab deals with
the neutron source term calculations for several-GeV electrons interacting with
liquid Deuterium targets. Electron scattering on a target nucleus is possible
with energy transfer sufficient to break the nucleus. This will result in the
prompt neutron emission and possible production of radioactive isotopes. At high
energies and on thin targets, such processes become major contributors to the
target radiation source terms and activation. Presently, electronuclear
reactions are not included in the list of Physics processes simulated by FLUKA.
Correspondingly, FLUKA utility is somewhat limited in such conditions. JLab is
getting ready to start using FLUKA extensively, and we would like to help
improve the situation with the description of electronuclear processes in the
code. I will discuss the method of Equivalent Photon Approximation and its
implementation in the DINREG/GEANT3 code presently in use at JLab. The method
allows to model hadronic interactions of every electron in an electromagnetic
cascade by representing it as a flux of "equivalent" real photons interacting
according to their total hadronic cross sections. Existing tools available in a
simulation code for generating real photon hadronic interactions can therefore
be utilized to simulate such interactions of electrons. Results of several
benchmark comparisons between thin target calculations in DINREG/GEANT3, Geant4,
and FLUKA will be discussed. A possible program of collaboration between JLab
and the FLUKA team may become beneficial to all parties.