Parametric Fit of the Total Neutron Cross Section of Manganese from 0.01 eV to 50 keV

Early work ascertained that the Mn total cross section could not be fit by the Breit-Wigner single-level formula. Later work showed that a satisfactory fit below 10 keV could be achieved by the use of R-matrix analysis. Here, recent resonance data and the Breit-Wigner multilevel formula are used to fit the experimental data from 0.01 eV to 50 keV. Two bound levels and several positive energy levels are introduced in order to produce very good agreement with the measured total cross section. The parametric representation of the ⁵⁵Mn cross section yields calculated values of 13.4 and 15 b for the capture 2200 m/sec cross section and resonance integral, and 1.94, 1.71, and 556 b for the thermal-bound atom, coherent-scattering cross section, and scattering resonance integral, respectively, all values being in good agreement with experiment. Qualitative agreement is obtained with polarization data.