Differential and angle-integrated cross sections for the 40Ca(n, α)37Ar reaction from 4.0 to 6.5 MeV

Abstract

Differential cross sections for the 40 Ca(n, $ \alpha_{{0}}^{}$ ) , $ (n,\alpha_{1,2})$ and $ (n,\alpha_{3,4,5})$ reactions are measured at neutron energies of 4.0, 4.5, 5.0, 5.5, 6.0 and 6.5MeV using a double-section gridded ionization chamber and two CaF2 samples. Monoenergetic neutrons were produced through the 2 H(d, n)3 He reaction with a deuterium gas target. A BF3 neutron counter was utilized to normalize the neutron flux among different measurements. The absolute value of neutron flux was calibrated using a 238U sample. Angle-integrated cross sections for the 40 Ca(n, $ \alpha_{{0}}^{}$ ) , $ (n,\alpha_{1,2})$ and $ (n,\alpha_{3,4,5})$ reactions are obtained from the integration of the differential data. Model calculations are performed using the TALYS-1.6 code and general agreement is achieved between measurements and calculations. Then the total 40Ca(n, $ \alpha$ )37Ar cross sections are derived from the angle-integrated cross sections combined with the code calculations. Present results are compared with existing measurements and evaluations.