The energy spectra of neutrons and photons emitted by thick targets of carbon, iron, copper, and lead at angles of 0, 15, 30, 45, 75, and 135 deg to the incident beam of 33-MeV deuteron, 65-MeV ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, and 65-MeV alpha ions were obtained by unfolding the pulse height distributions measured with an NE-213 scintillator. The angular distributions of neutrons above 4 MeV and photons above 1.5 MeV were obtained by integrating the measured spectra. The total neutron yield was obtained by estimating the neutron yield below a few MeV by fitting the spectra measured above that energy to the Maxwellian distribution and showed good agreement with other experimental results. The measured spectra were analyzed by the thick-target radiation transport Monte Carlo code based on the intranuclear-cascade-evaporation model. The validity of the model was tested at the lower projectile energy limit through this comparison.

• Received 8 November 1983

DOI:https://doi.org/10.1103/PhysRevC.29.1307