CALCULATION OF NEUTRON TIME-OF-FLIGHT AND ENERGY SPECTRA BEHIND THICK SHIELDING OF AN ELECTRON ACCELERATOR AND COMPARISON TO EXPERIMENTAL DATA

摘要

Energy spectra of high-energy neutrons and neutron time-of-flight spectra were calculated for the set-up of experiment T-454 performed with a NE213 liquid scintillator at the Final Focus Test Beam (FFTB) facility at the Stanford Linear Accelerator Center. The neutrons were created by the interaction of a 28.7 GeV electron beam in the aluminium beam dump of the FFTB which is housed inside a thick steel and concrete shielding. To determine the attenuation length of high-energy neutrons, additional concrete shielding of various thicknesses was placed outside the existing shielding. The calculations were performed using the FLUKA interaction and transport code. The energy and time-of-flight were recorded for the location of the detector allowing a detailed comparison with the experimental data. A generally good description of the data is achieved, adding confidence in the use of FLUKA for the shielding design of high-energy electron accelerators.