Integral measurement of the $^{12}$C(n,p)$^{12}$B reaction up to 10 GeV

Abstract

The integral measurement of the 12 C(n,p) 12 B reaction was performed at the neutron time of flight facility n TOF at CERN. The total number of 12 B nuclei produced per neutron pulse of the n TOF beam was determined using the activation technique in combination with a time of flight technique. The cross section is integrated over the n TOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1 GeV on basis of the 235 U(n,f) reaction, the neutron energy spectrum above 200 MeV has been reevaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the 12 C(n,p) 12 B reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which mostly underestimate the 12 B production. On the contrary, a good reproduction of the integral cross section derived from measurements is obtained with TALYS-1.6 calculations, with optimized parameters.