Measurement of Thermal Neutron Capture Cross Section and Resonance Integral for the $^{45}$Sc$(n,\gamma)^{46}$Sc Reaction with Pulsed Neutrons

Abstract

Thermal neutron capture cross section and resonance integral for the $^{45}$Sc(n,$\gamma )^{46}$Sc reaction were measured by the activation method using the $^{197}$Au(n,$\gamma )^{198}$Au reaction as a single comparator. The high-purity scandium and gold samples with and without Cd cover with the thickness of 0.5 mm were irradiated in a pulsed neutron field of the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL). The induced activities in the activated foils were measured with a well calibrated HPGe detector. In order to improve the accuracy of the experimental results the effect of the non-ideal epithermal spectrum was taken in to account by determining the neutron spectrum shape factor ($\alpha )$, and the corrections for the thermal (G$_{th})$ and the resonance (G$_{epi})$ neutron self-shielding effects, the $\gamma $-ray attenuation (F$_{g})$ and the $\gamma $-ray coincidence summing effect were made. The thermal neutron cross-section for the $^{45}$Sc(n,$\gamma )^{46}$Sc reaction has been determined to be $\sigma _{o}$ = 27.6 $\pm $ 0.8 barn. By assuming the cadmium cut-off energy of 0.55 eV, the resonance integral for the $^{45}$Sc(n,$\gamma )^{46}$Sc reaction has been determined to be I$_{o}$ = 12.7 $\pm $ 0.7 bar. The present results are compared with the reference data and discussed.