MATTERS RELATED TO THE NEANDC TASK FORCES ON 238U AND 56FE RESONANCES
Harwell Laboratory, UKAEA, Oxon., UK
CEC, JRC, Central Bureau for Nuclear Measurements, Geel, Belgium
Following the Antwerp Conference, Task Forces were appointed by the Nuclear Energy Agency Nuclear Data Committee (NEANDC) to investigate discrepancies in the resolved resonance parameters of 238U and the 1.15 keV resonance in 56Fe. The 238U Task Force also considered the discrepancies in the measurements of the 238U capture cross-section between 1 and 30 keV. The work of the Task Forces was reviewed at the Santa Fé Conference where it was concluded that the origins of the 238U discrepancies were largely understood. For 56Fe it was clear that a consistent set of resonance parameters could be obtained from improved transmission measurements for the 1.15 keV resonance. However, the discrepancy between the results of capture and those of transmission remained. The work undertaken since Santa Fé on matters related to the Task Forces is reviewed. In the case of 238U, particular emphasis is placed on the reanalysis and evaluation of resolved resonance parameters. In the case of 56Fe, the attention is focussed on the experimental determination of the response functions of capture detectors and on the comparison of these data with calculations.
KEYWORDS: 238U, resonance parameters, capture cross-section, 56Fe 1.15 keV resonance, capture detectors, resonance parameters