Neutron capture and total cross sections of 144Sm.

Abstract

Neutron capture and transmission measurements have been made from 0.5 eV to 500 keV and have been analyzed to give parameters of resonances up to \ensuremath{\sim}100 keV. The average resonance spacing for s-wave resonances was determined to be 670\ifmmode\pm\else\textpm\fi{}60 eV and the s-wave strength function (3.6\ifmmode\pm\else\textpm\fi{}0.8)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}4}$. The average radiation width for s-wave resonances was 74\ifmmode\pm\else\textpm\fi{}5 meV and that for p-wave resonances somewhat larger \ensuremath{\sim}89 meV. The Maxwellian average capture cross section at a stellar temperature of 30 keV was 92\ifmmode\pm\else\textpm\fi{}6 mb. The capture resonance integral of 1.7\ifmmode\pm\else\textpm\fi{}0.1 b calculated from the resonance parameters and the thermal cross section is smaller than the recently measured value of 2.38\ifmmode\pm\else\textpm\fi{}0.17 b.