Measurement of neutron leakage spectra at a 500-MeV proton accelerator

We have measured the neutron leakage spectra at a number of representative locations outside the shielding of a 500-MeV proton accelerator using a multisphere technique and the 12C(n,2n)11C reaction in a plastic scintillator. The inclusion of the 12C(n,2n)11C reaction in the set of responses has a pronounced effect on the shape of the unfolded neutron spectra and the ambient dose equivalent rate calculated from them.