Elastic Scattering of Heavy Ions byPb206,Pb207, andPb208

Abstract

The angular distributions of ${\mathrm{C}}^{12}$, ${\mathrm{N}}^{14}$, ${\mathrm{O}}^{16}$, and ${\mathrm{Ne}}^{20}$ elastically scattered by ${\mathrm{Pb}}^{206}$, ${\mathrm{Pb}}^{207}$, and ${\mathrm{Pb}}^{208}$ have been measured at laboratory energies of approximately 10.4 MeV/nucleon. The elastically scattered ions were recorded in photographic emulsions at laboratory angles from 17° to 175°. In general, measurements were extended only to angles where the ratio of the cross section to the Coulomb cross section, $\frac{\sigma }{{\sigma }_c}$, was greater than 0.2. In one case, the measurement was extended to a region where $\frac{\sigma }{{\sigma }_c}\le 1.2\times {10}^{-5\mathrm{}}$. The cross sections all exhibited a behavior similar to that previously reported for the same ions on ${\mathrm{Au}}^{197}$ and ${\mathrm{Bi}}^{209}$. Excellent agreement with the semiclassical strong absorption model was obtained. Nuclear interaction distances calculated by fitting the strong absorption calculations are consistent with $r_0=1.45\mathrm{}$ F, where $R=r_0({A_1}^{\frac{1}{3}}+{A_2}^{\frac{1}{3}})$.