  A calorimetric-time-of-flight (CTOF) technique was used for real-time,
high-precision measurement of neutron spectrum at the angle of 175 degrees from
the initial proton beam direction, which hits a face plane of a cylindrical
iron target of 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 0.4-, 0.6-, 0.8-, 1.0-, and 1.2-GeV protons.
