Neutron Energy Distributions in Proton Bombardment of Be and C at 100 Mev

The energy distributions of neutrons emitted in the forward direction when beryllium and carbon targets are bombarded by 100-Mev protons were investigated. The neutron energy distribution was found from the range distribution of recoil protons from a polyethylene target, measured with a scintillation counter telescope. The distribution for beryllium was found to be peaked at about 93 Mev, while the distribution for carbon fell off rapidly above 70 Mev. The influence on the observed distribution of energy resolution effects, particularly those involving energy spread of the cyclotron proton beam, is discussed.