The effect of scattering interference term on the practical width

The practical width Image has an important application in the characterization of the resonance type for the calculation of neutron average cross sections. Previous treatments ignore the interference term Image for the Doppler broadening function in the practical width calculation. In the present paper, a rational approximation for the Image function is derived, using a modified asymptotic Padé method. A new approximation for Γp is obtained. The results which are presented here provide evidence that the practical width as a function of temperature varies considerably with the inclusion of the interference term Image .