Measurement of Thermal Neutron Capture Cross Section and Resonance Integral of the 129(n,.GAMMA.)130I Reaction.

Abstract

To obtain fundamental data for research on the transmutation of nuclear wastes, the thermal neutron cross section and the resonance integral of the 129I(n, γ)130I reaction have been measured using an activation method. The neutron cross sections for the formation of the ground (5+) state and the isomeric (2+) state of 130I were measured separately. Six 129I targets were irradiated for 10 min with thermal reactor neutrons; three of them containing 2.55- 2.61 kBq of 129I were irradiated within a Cd capsule, and the other three targets containing 259–261 Bq of 129I were irradiated without it. The Co/Al and Au/Al alloy wires were used to monitor the neutron flux and the fraction of the epithermal part (Westcott's epithermal index). The gamma-ray spectra from the irradiated samples were measured with a Ge detector. The thermal neutron capture cross section (the 2,200 m/s neutron cross section) and the resonance integral of the 129I(n, 7)130I reaction were determined to be 12.5±0.5b and 15.6±0.7b for the format...