Radiation Width Variations in the Slow-Neutron Resonances of Europium and Indium

The parameters of the lowest-energy resonances in europium and indium have been determined from total cross section measurements using the Brookhaven crystal spectrometer. The data have been analyzed for variations in the radiation width parameter ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}}$ from resonance to resonance. The method of analysis used to take account of Doppler effect in the observed cross section is discussed. The radiation width in the 0.327 -ev resonance in Eu is 70\ifmmode\pm\else\textpm\fi{}10 mv, which is definitely smaller than that for the 0.461-ev and 1.056-ev resonances which are respectively 93\ifmmode\pm\else\textpm\fi{}3 mv and 94\ifmmode\pm\else\textpm\fi{}3 mv. The widths of the 1.456-ev and 3.85-ev resonances in In are 72\ifmmode\pm\else\textpm\fi{}2 mv and 81\ifmmode\pm\else\textpm\fi{}4 mv respectively. The remaining one-level parameters for each resonance are also presented.