Excitation Functions for Alpha-Induced Reactions on Zinc-64

Abstract

Eleven excitation functions for alpha-induced reactions on ${\mathrm{Zn}}^{64}$ have been measured up to incident energies of 41 Mev. The values of $\frac{\sigma (\alpha , p)}{\sigma (\alpha , n)}$ and $\frac{\sigma (\alpha , pn)}{\sigma (\alpha , 2n)}$ in the region of maximum yield were found to be 1.7 and 9, respectively. Reactions involving alpha-particle emission account for about 20% of the total inelastic cross section at 40 Mev. The total inelastic cross section was found to agree with calculated values for $r_0=1.6\mathrm{}\times {10}^{-13\mathrm{}}$ cm. The competition between different reactions was analyzed in terms of the statistical theory by use of a level density expression of the form $W\left(E\right)=C\exp \left\{2\mathrm{}{\left[a\right(E-\delta \left)\right]}^{\frac{1}{2}}\right\}$. Values of $a$ ranging from 0.8 to 2.8 were required to fit the experimental results, indicating that the statistical theory is not completely applicable.