Search

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.

Differential scattering cross-section data have been measured at 43 angles from ${11}^{\ifmmode^\circ\else\textdegree\fi{}}$ to ${160}^{\ifmmode^\circ\else\textdegree\fi{}}$ for 37-MeV neutrons incident on $^{209}\mathrm{Bi}$. The primary motivation for the measurements is to address the scarcity of neutron scattering data above 30 MeV and to improve the accuracy of optical-model predictions at medium neutron energies. The high-statistics measurements were conducted at the China Institute of Atomic Energy using the $^{3}\mathrm{H}$($d,n$)$^{4}\mathrm{He}$ reaction as the neutron source, a pulsed deuteron beam, and time-of-flight (TOF) techniques. Within the resolution of the TOF spectrometer, the measurements included inelastic scattering components. The sum of elastic and inelastic scattering cross sections was computed in joint optical-model and distorted-wave Born approximation calculations under the assumption of the weak particle-core coupling. The results challenge predictions from well-established spherical optical potentials. Good agreement between data and calculations is achieved at 37 MeV provided that the balance between surface and volume absorption in a recent successful model [A. J. Koning and J. P. Delaroche, Nucl. Phys. A 713, 231 (2003)] is modified, thus suggesting the need for global optical-model improvements at medium neutron energies.