The Effective Resonance Integrals of U-238 and Th-232

Numerical calculations performed on the ORACLE have made possible exact inclusion of the effect of Doppler broadening of resonance lines in the calculation of resonance absorption integrals. The effective resonance integrals of U²³⁸ and Th²³² have been calculated as functions of the scattering cross section per absorbing nucleus for 0° and 300°K. Agreement of the calculated (300°K) and experimental resonance integrals is excellent for U²³⁸ and good for Th²³², except in the case of pure ThO₂ where a discrepancy is noted.