New Cadmium Transmission Measurements in the Thermal and Low Energy region at GELINA

Sheets of cadmium (Cd) of variant thickness are often used as a neutron absorber in integral neutron experiments, such as integral benchmark and neutron activation measurements. The near-thermal resonance in 113Cd at 0.178 eV removes the neutron flux below at a nominal energy of 0.5 eV. Consequently, the neutron cross-sections of natCd are very important for a correct interpretation and analysis of such experiments. Nonetheless, the neutron total, capture and scattering cross sections in cadmium have not been studied often and experiments covering the energy region from a few meV up to the low energy part of the resolve resonance region (RRR) have not been performed. The last major experiment, that could be used in non-fundamental applications was performed by Liou et al. in 1974. The lack of good quality data for cadmium may be a source of the long standing discrepancy between resonance integral measurements and the values calculated from the resolved resonance parameters. Therefore, it was suggested that some new measurements should be carried out at IRMM Geel on natural Cd to try to resolve this problem. These measurements were performed in collaboration with the IAEA, Vienna in the framework of NUDAME. As a part of these measurements we carried out 6 new Cd transmission measurements at 50 Hz working frequency of GELINA. These experiments were built up at 26 m and 50 m flight paths of GELINA, using natural Cd samples with thicknesses of 0.030 mm, 0.050 mm, 0,125 mm, 25.8 mm enriched up to 99.99 % in Cd, and a Cd (NO3)2.4H2O solution sample. The transmission measurements at 50 Hz of the two thin Cd foil samples and the Cd solution sample were performed especially in order to obtain quality data in the thermal energy region, from which we could extract the resonance parameters for the first well-known resonance of 113Cd at 0.178 eV. The data obtained in our 50 Hz measurements were compared to the existing one in ENDF/B-VI library. In this paper we report our first results from the analysis of the data obtained in these measurements. The resonance parameters were extracted from the transmission data by using the analysis code REFIT.

IVANOV Ivaylo;  SIEGLER Peter;  KOPECKY Stefan;  MOXON Michael; 

2009-11-11

Bulgarian Nuclear Society

JRC44038

1310-8727,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC44038,