The CTOF measurements and Monte Carlo analyses of neutron spectra for backward direction from tungsten target irradiated by protons with energies from 200 to 1200 MeV

A calorimetric-time-of-flight (CTOF) technique was used for real-time, high-precision measurement of neutron spectrum at the angle of 175° from the initial proton beam direction, which hits a face plane of a cylindrical tungsten target 20 cm in diameter and 25 cm thick. A comparison was performed between the neutron spectra predicted by the MARS and the MCNPX code systems and measured by experiments for 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 GeV protons.