Simulations of photoneutron spectra due to incident high energy electrons on t ungsten target using FLUKA

Bremsstrahlung photons followed by photoneutrons are the major radiation hazards in high energy electron accelerators. These neutrons in high energy electron accelerator are produced by Bremsstrahlung photons through photo nuclear reactions. Monte Carlo code FLUKA was used to generate the photoneutron spectra for 20 MeV, 450 MeV and 2.5 GeV electron (electron energies in Indus facility) hitting 4 mm of tungsten target. The total photoneutron yield was calculated from the generated spectrum for different target thicknesses. The results have indicated the isotropic Giant Dipole Resonance (GDR) neutrons dominating the spectra for the above three incident electron energies. The peak energy of the neutron spectra lies between 0.1-1 MeV for these electron energies. The average neutron energy was calculated and found to be 0.82 MeV, 4.09 MeV and 11.6 MeV for 20 MeV, 450 MeV and 2.5 GeV incident electron energy, respectively. The details of the simulation and results are discussed in the paper.