Elastic scattering cross sections for 65 MeV neutrons have been measured for natural targets of C, Si, Cd, Fe, Sn, and Pb at laboratory angles from 6' to 45'. A unique, compact detection system consisting of a CHq (proton) converter and large-acceptance, wire-chamber-based, recoilproton telescope is utilized for the measurements. The data are compared with macroscopic optical model potentials derived from proton scattering. In addition, comparisons with the microscopic optical model potentials, those of 3eukenne-Lejeune-Mahaux and Yamaguchi-Nagata-Matsuda, give a very good at to the data.

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New elastic and inelastic neutron scattering data for 6 Li taken at 24.0 MeV have been analyzed in conjunction with existing proton scattering data for these targets at 24.4 MeV. The new data allow us to infer that p"=p~i n Li and Li in contrast with the results p"=(N/Z)p~deduced from earlier proton and electron work.

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The Al 27 (^,#)Si 27 , Si 29 (p,n)V®, and ~P u (p,n)S u ground-state reactions have been measured using poly ethylene "long counters." Absolute cross sections and angular distributions were obtained from 0° to 160° at 10° intervals. The measured angular distributions were compared with the predictions of an optical-model calculation, using an optical potential suggested by Lane, which is a function of the isotopic spins of the incident proton and target nucleus. Since the ground-state (p,n) reactions were measured below the threshold for the excited state, the proton incident energies were between 5.8 and 7.6 MeV. Because of this low proton energy, the optical-model calculations include both Coulomb effects of distortion of the proton wave and the Coulomb energy difference between the incoming proton and the outgoing neutron. Fair agreement between the theoretical and experimental results was obtained for Si 29 and P 31 using a surface interaction for the imaginary and isobaric parts of the optical potential. Furthermore, the angular distributions from these two nuclei wefe quite similar in structure, in agreement with the twin-reaction hypothesis of Bloom, Glendenning, and Moszkowski. The neutron angular distributions from Al 27 are quite different in structure from those obtained from Si 29 and P 31 , and attempts to fit them with the optical-model calculation were not successful. A calculation based on distorted-wave single-particle excitation with charge-exchange was also. carried out. The results of this calculation agree with those of the optical model for Si 29 and P 31 . For the Al 27 reaction the results of the DWBA calculation are different from those of the optical model, since in the former calculation momentum transfers greater than zero are included; however, neither calculation fitted the Al 27 data.

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Experimental results are presented on the charge, velocity, and angular distributions of intermediate mass fragments (IMFs) for the reaction Fe+Au at bombarding energies of 50 and 100 MeV/nucleon.Results are compared to the quantum molecular dynamics (QMD) model and a modified QMD which includes a Pauli potential and follows the subsequent statistical decay of excited reaction products. The more complete model gives a good representation of the data and suggests that the major source of IMFs at large angles is due to multifragmentation of the target residue.PACS number(s): 25.70.Mn