Influence of electronic stopping power on the total neutron yield of energetic heavy ions

High-energy protons bombarding matter are stopped mostly by inelastic collisions with the target nuclei, inducing a high level of radio-activation. In contrary, it is shown here that the penetration depth of heavy ions with energy below 1 GeV/u is mostly determined by the electronic stopping power. This results in lower activation levels, which is important for estimating the tolerable beam loss limit in high intensity heavy ion accelerators. A method to calculate the total neutron yield of heavy ions bombarding thick targets is proposed, validated by measured data and applied to the tolerable beam loss limit in heavy ion accelerators in the energy range E=100 MeV/u–1 GeV/u.