Resonant Cross Section for 14.4-keV Gamma-Ray Absorption inFe57

Abstract

The resonant cross section and internal conversion coefficients of the 14.4-keV level in ${\mathrm{Fe}}^{57}$ are determined from Mössbauer absorption spectra of thin polarized iron foils. We obtain a value for the maximum resonant cross section of (2.56±0.05) × ${10}^{-18\mathrm{}}$ ${\mathrm{cm}}^2$, which leads to a total internal conversion coefficient of 8.19±0.18. This value for the internal conversion coefficient is in excellent agreement with recent results from x-x-ray and x-$\gamma$-ray coincident experiments and is nearly 10% lower than the previously accepted value.