Photoproduction of high-energy neutrons in thick targets by electrons in the energy range 150 to 270 MeV

Abstract

Photoneutron spectra with energies greater than 12 MeV produced by electrons incident on a thick lead target have been measured for primary electron energies between 150 and 266 MeV and at a fixed angle of 90 ~ to the beam axis. Measurements of the neutron yield have furthermore been performed at a primary energy of 234 MeV as a function of target depth for the same lead target and as a function of the mass number for C, A1, Cu, Cd and Pb targets. The results were obtained with three independent neutron detectors: two proton recoil counters and one time-of-flight set-up. The high-energy regions of the spectra are compared with the predictions of the phenomenological quasi-deuteron model and a satisfactory agreement in shape and scale of the spectra is found. Additional high-energy neutrons from pion reabsorption processes were observed at electron energies of 234 and 266 MeV.

Nucleon-nucleon correlations inside atomic nuclei: synergies, observations and theoretical models

“…Still, there were rather few studies which highlighted the quasi-deuteron mechanism as an important reaction mechanism in this energy region for electron beams. One example of high energy neutron production at 90 • was investigated for electron beam energies between 150 and 260 MeV by Eyss and Lührs at Mainz in 1973 [49]. Neutron production for 150-200 MeV was nicely accounted for by the quasi-deuteron based model by Matthews et al [50] while an additional neutron-production bump was observed for higher energy electrons due to the onset of pion-production channels.…”

Rare Gas Isotope Yields in Bremsstrahlung-induced Nuclear Reactions of 41K, 87Rb, 127I, 133Cs,and 139La

“…Correction for the yields from the secondary reactions was performed on the basis of the excitation functions for these secondary reactions calculated with the ALICE code [24,25], the reported photoproton [26][27][28], and photoneutron spectra [29,30]. The details of the method as well as the Parameter evaluation for the calculation were described in Refs.…”