Neutron yield and dose equivalent from heavy ion interactions on thick target

Thick target neutron yields and angular distributions are essential for shielding calculations for ion beam accelerators. Most of such measurements available in the literature are for proton and alpha particle bombardments. In case of heavy ions, very few data are available in the energy region of 20 MeV amu-1 and below. We report here the neutron yield, double differential neutron yields and neutron dose equivalent values obtained from the double differential yields at 0 deg. and 90 deg. with respect to the beam for various heavy ions in the energy range of 3.5-7.0 MeV amu-1. Pulse shape discrimination was used to separate neutrons from gamma rays and time of flight technique was used for energy measurement. The double differential neutron yields were fitted using the moving source model and the nuclear temperature and source intensity are also determined. The neutron yield increases inversely with the mass of the projectile except in the case of 7Li where the yields are much lower than that obtained from 11B. This could be due to the structure of the loosely bound 7Li projectile. The neutron dose equivalent shows increasing trend with the decrease of the mass of the projectile