Angular Distributions of Fission Fragments from 22-Mev Proton-Induced Thorium Fission

The angular distributions of barium, strontium, zirconium, ruthenium, and silver fission products from thorium fission induced by 22-Mev protons were measured using the internal, circulating beam of the ORNL 86-inch cyclotron. Within the accuracy of the measurements, all angular distributions are symmetric about 90° and may be well fitted to $I\left(\theta \right)=a+b{cos}^2\theta$. For Ba, Sr, Zr, Ru, and Ag fission products, for which the fission mass ratios are 1.53, 1.52, 1.37, 1.19, and 1.04, the anisotropy ($\frac{b}{a}$) is 0.26, 0.25, 0.19, 0.15, and 0.10, respectively.