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Using a gridded ionization chamber, angular distributions for the 64 Zn(n,α) 61 Ni reaction were measured at 5.0, 5.7, and 6.5 MeV. The neutrons were produced through the D(d, n ) 3 He reaction. The neutron flux was determined through the 238 U(n, f) reaction. The results show a backward peak in the center-of-mass reference system for 5.7 and 6.5 MeV. The cross sections are 72.5, 72.0, and 70.8 mb for 5.0, 5.7, and 6.5 MeV, respectively.

The differential cross sections of the {sup 6}Li(n,t){sup 4}He reaction were measured at 1.85 and 2.67 MeV by using a gridded ionization chamber. Neutrons were produced through the T(p,n){sup 3}He reaction. The absolute neutron flux was determined through the {sup 238}U(n,f) reaction. Results are compared with existing data.

The differential cross sections of the 10 B(n, α) 7 Li reaction were measured at 4.17, 5.02, 5. 74, and 6.52 MeV by using a gridded ionization chamber. Neutrons were produced through the D(d,n) 3 He reaction. The absolute neutron flux was determined through the 238 U(n,f) reaction. The experiment shows that as the neutron energy increases from 4.17 to 6.52 MeV, the differential cross section changes from almost 90-deg symmetry to obviously backward peaked in the center-of-mass reference system.

The experiment of determination of the 64Zn(n, α)61Ni reaction cross section in the 5.0 - 6.75 MeV neutron energy range was performed at the 4.5 MV Van de Graaff accelerator at the Institute of Heavy Ion Physics, Peking University, Beijing. A double section ionization chamber with grids was used for direct registration of the reaction products. The cross sections and angular distributions were extracted from the experimental data. The obtained values were compared with the results of other authors and theoretical estimations. The analysis of the experimental data and model calculations were carried out.

A gridded ionization chamber was used to measure the differential cross sections for tritons from the {sup 6}Li(n,t){sup 4}He reaction at 3.67 and 4.42 MeV. Neutrons were produced via the D(d,n){sup 3}He reaction. The absolute neutron flux was determined through the {sup 238}U(n,f) and H(n,p) reactions. At 3.67 MeV the result is almost 90 deg symmetric, but it is obviously forward peaked at 4.42 MeV in the center-of-mass reference system.

Cross sections, angular distributions, and double-differential cross sections were measured for 39 K(n,α) 36 Cl reactions at E n = 4.5,'5.5, and 6.5 MeV and for 40 Ca(n,α) 37 Ar reactions at E n = 5.0 to 6.0 MeV, using a twin-gridded ionization chamber, and the experimental data were analyzed with the UNF code. The results indicate that the optical model parameters employed in the calculation are appropriate in the energy region. The energy level densities used in our calculations are a little different from the findings of Gilbert and Cameron, and the pair corrections of some nuclei are much smaller than what was determined by them. The experiment and model calculation results indicate that in the energy region below 7 MeV, the compound nuclear mechanism is predominant; at 6.5 MeV, the preequilibrium emission is ∼12%.