Measurement of the Thermal Neutron Capture Cross Section and the Resonance Integral of the⁹⁰Sr(n, γ)⁹¹Sr Reaction

Abstract

The thermal neutron capture cross section (σ 0 ) and the resonance integral (I 0 ) of the 90 Sr(n, γ ) 91 Sr reaction were measured with an activation method to provide fundamental data for research on nuclear transmutation methods of radioactive wastes. Strontium chloride containing 3.7×10 2 kBq of 90 Sr was irradiated for 10 h in the hydraulic transfer tube facility of Kyoto University Reactor. Flux monitor wires, Co/Al and Au/Al alloy wires, were irradiated together with the targets to determine the neutron flux and the fraction of epithermal component (Westcott's index) at the target position. A high purity Ge detector was used to measure the γ rays from the irradiated targets and monitor wires. The σ 0 was obtained as 10.1±1.3 mb, and I 0 as 104±16 mb.

Measurement of Effective Capture Cross Section of238Np for Thermal Neutrons

“…The BGO detector worked as an anti-coincidence spectrometer to improve the peak-to-background ratio of the Ge detector. The BGO detector has a cylindrical shape with an inner diameter of 11cm and a length a) Absolute intensity of -ray(-ray emission probability per decay) b) The G is a self-absorption coefficient 13) for -ray from the flux monitor wire.…”

“…The inner and outer casings work as heat transport material, and also for sample confinement. The irradiation capsule 13) was irradiated for 10 h in the hydraulic conveyor tube of Kyoto University Reactor (KUR). The error of the irradiation time was less than 10 s. The irradiation position in the tube has a Maxwellian spectrum in the thermal energy region and a 1=E spectrum in the epithermal energy region.…”