Impact parameter dependence of light charged particle production in $25A\hspace{0.5em}\mathrm{MeV}{\hspace{0.5em}}^{16}\mathrm{O}$ on Tb, Ta, and Au and $35A\hspace{0.5em}\mathrm{MeV}{\hspace{0.5em}}^{14}\mathrm{N}$ on Sm and Ta

The impact parameter dependence of light charged particle $(p,d,t,\alpha )$ emission has been studied using an impact parameter selection based on coincident detection of residues or fission fragments. The energy spectra at twelve angles between $20°$ and $150°$ have been fit by a multiple moving source parametrization. The angle and energy integrated preequilibrium proton multiplicities decrease with increasing impact parameter in qualitative agreement with a Fermi jet calculation. The preequilibrium $d/p$ and $t/p$ multiplicities increase slowly with increasing impact parameter and are nearly identical at the two bombarding energies. The preequilibrium $\alpha /p$ ratio shows a less consistent dependency on impact parameter but decreases significantly with increasing bombardment energy. A calculation of the $d/p$ and $t/p$ multiplicity ratios with a transport model incorporating complex particle emission is quite successful in reproducing the absolute magnitude, impact parameter dependence, and bombarding energy dependence of the experimental total multiplicities.