Charge, energy, and angular distributions of products from reactions between ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ and Ni have been measured at 164 MeV. The total reaction cross section inferred from the quarter-point of the elastic scattering data is 2010 mb. Products with $6\le Z\le 20$ account for 30% of the total reaction cross section. The evaporation residue cross section was also measured and found to be 1236 mb, or 61% of the total cross section. Products with atomic number near that of the projectile have angular distributions which increase in the forward direction and have energy spectra characteristic of both quasielastic and deeply inelastic events. Products with atomic numbers greater than 14 show an angular distribution $\frac{d\sigma }{d\Omega }\propto \frac{1}{{sin\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}}$ and have kinetic energies that are characteristic of Coulomb repulsion following binary fission, indicating that complete damping has occurred. However, the yield near $Z=19\mathrm{}$ is low, and thus symmetric fission, if present at all, accounts for a rather small fraction of the total reaction cross section.

NUCLEAR REACTIONS ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ + Ni; $E=164\mathrm{}$ MeV; strongly damped; $10°<~{\psi }_{\mathrm{lab}}<~70°$; quasielastic; product energies, charge distributions, cross sections $\frac{d\sigma }{d{\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}}$; evaporation residue cross section ${\sigma }_{\mathrm{ER}}$; reaction cross section; gas ionization detector $\Delta E$; surface barrier detector $E$.

• Received 13 February 1978

DOI:https://doi.org/10.1103/PhysRevC.18.764