Thermal neutron capture and resonance integral cross sections of Sc-45

Abstract

The thermal neutron cross section (sigma(0)) and resonance integral (I-0) of the Sc-45(n,gamma)Sc-46 reaction have been measured relative to that of the Au-197(n,gamma)Au-198 reaction by means of the activation method. High-purity natural scandium and gold foils without and with a cadmium cover of 0.5 mm thickness were irradiated with moderated pulsed neutrons produced from the Pohang Neutron Facility (PNF). The induced activities in the activated foils were measured with a high purity germanium (HPGe) detector. In order to improve the accuracy of the experimental results the counting losses caused by the thermal (G(th)) and resonance (G(epi)) neutron self-shielding, the gamma-ray attenuation (F-g) and the true gamma-ray coincidence summing effects were made. In addition, the effect of non-ideal epithermal spectrum was also taken into account by determining the neutron spectrum shape factor (alpha). The thermal neutron cross-section and resonance integral of the Sc-45(n,gamma)Sc-46 reaction have been determined relative to the reference values of the Au-197(n,gamma)Au-198 reaction, with sigma(o,Au) = 98.65 +/- 0.09 barn and = 1550 +/- 28 barn. The present thermal neutron cross section has been determined to be sigma(o,Sc) = 27.5 +/- 0.8 barn. According to the definition of cadmium cut-off energy at 0.55 eV, the present resonance integral cross section has been determined to be I-o,I-Sc = 12.4 +/- 0.7 barn. The present results are compared with literature values and discussed. (C) 2015 Elsevier B.V. All rights reserved.