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AbstractBy using a twin-gridded ionization chamber, differential cross-section data of the 64Zn(n,α)61Ni reaction were measured at neutron energies of 2.54, 4.00, and 5.50 MeV. The experiment was performed at the 4.5-MV Van de Graaff accelerator of the Institute of Heavy Ion Physics, Peking University, China. Monoenergetic neutrons of 2.54 MeV were produced through the T(p,n)3He reaction with a solid Ti-T target, and those of 4.00 and 5.50 MeV were produced through the D(d,n)3He reaction with a deuterium gas target. The absolute neutron flux was determined through the 238U(n,f) reaction and a BF3long counter was used as the neutron flux monitor. Results of the present work are combined with our previous data between 5.0 and 6.5 MeV and compared with other measurements and evaluations.

AbstractDifferential cross sections of the 64Zn(n,α)61Ni reaction were measured at neutron energies of 5.03 and 5.95 MeV by using a gridded ionization chamber. The experiment was performed at the 4.5-MV Van de Graaff accelerator of the Institute of Heavy Ion Physics, Peking University. Neutrons were produced through the D(d,n)3He reaction with a deuterium gas target. The absolute neutron flux was determined by the 238U(n,f) reaction and a calibrated BF3long counter. Present results are compared with existing data.

AbstractDifferential cross sections and angle-integrated cross sections of the 6Li(n,t)4He reaction were measured at En= 1.05, 1.54, and 2.25 MeV by using the gridded ionization chamber method. A 6LiF sample and a 238U sample were set back-to-back inside the twin chamber for measurement. Neutrons were produced through the T(p,n)3He reaction. The absolute neutron flux for En= 2.25 MeV was determined by the 238U(n,f) reaction, and those for En= 1.54 MeV and En= 1.05 MeV were determined by a calibrated BF3long counter. Present results are compared with existing data.

AbstractUsing a gridded ionization chamber, angular distributions for the 64Zn(n, α)61Ni reaction were measured at 5.0, 5.7, and 6.5 MeV. The neutrons were produced through the D(d,n)3He reaction. The neutron flux was determined through the 238U(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.

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

AbstractThe differential cross sections of the 10B(n, α)7Li 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)3He reaction. The absolute neutron flux was determined through the 238U(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.

AbstractBased on analyses of previous experimental methods and results, the cross sections of the 186W(n, γ)187W reaction were measured in the neutron energy range from 0.50 to 1.50 MeV by the activation technique. Neutrons were produced through the T(p,n)3He reaction, and the cross sections of the 197Au(n, γ)198Au reaction were used to determine the absolute neutron flux. Experimental results agreed with the previous time-of-flight measurements but did not agree with the previous activation measurements. Without the tungsten resonance absorption foils, the measured cross sections of the 186W(n, γ)187W reaction by the activation method were shown to be larger than the corrected ones because of the interference of the low-energy neutrons.

AbstractA gridded ionization chamber was used to measure the differential cross sections for tritons from the 6Li(n,t)4He reaction at 3.67 and 4.42 MeV. Neutrons were produced via the D(d,n)3He reaction. The absolute neutron flux was determined through the 238U(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.

AbstractCross sections, angular distributions, and double-differential cross sections were measured for 39K(n,α)36Cl reactions at En= 4.5, 5.5, and 6.5 MeV and for 40Ca(n,α)37Ar reactions at En= 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%.