Isotopically resolved intermediate-mass fragment and light charged particle production from the reactions 40 Ar and 40 Ca with 58 Fe and 58 Ni at E beam = 33 and 45 MeV/nucleon

Isotopically resolved intermediate-mass fragments and light charged particles have been detected from the reactions ${}^{40}\mathrm{Ar}$ and ${}^{40}\mathrm{Ca}$ with ${}^{58}\mathrm{Fe}$ and ${}^{58}\mathrm{Ni}$ at ${E}_{\mathrm{beam}}=33$ and 45 MeV/nucleon. There is an angular dependence to the isotopic ratios. A moving source analysis shows that fragments emitted at ${\ensuremath{\Theta}}_{\mathrm{lab}}=40\ifmmode^\circ\else\textdegree\fi{}$ can be attributed primarily to a composite source while the fragments emitted at backward angles are primarily from a targetlike source. The results are compared to predictions of QMD, BUU, and GEMINI. QMD generally reproduces the charge distribution and energy spectra and has partial success with the isobaric ratios when the system is chemically equilibrated. All of the models have difficulty reproducing the isotopic ratios when the system is not chemically equilibrated.