Resonance and thermal-neutron total cross sections for promethium-147 and promethium-148m

Resonance parameters for 147Pm and 148mPm have been determined and the resonances 147Pm have been analyzed up to 317 eV. Only one resonance was observed for 148mPm; its location at 0.17 eV is important for thermal reactor calculations Transmission measurements were initially made on four samples of 147Pm2O3 containing 1.6% of the decay product 147Sm. Later measurements, made on a mixed sample of (148mPm + 147Pm)2O3 and on 147Sm, provided resonance parameters for 147Pm and an opportunity for a complete reevaluation of the previous 147Pm results. Corrections for the samarium content could also be made. Both shape and area analyses were performed. The measured total cross section for 147Pm at 0.025 eV was 198 ± 8 b and a capture resonance integral of 2280 ± 200 b was calculated. Using the parameters of the 148mPm resonance at 0.17 eV, a corresponding total thermal-neutron cross section of 10 600 b was ob-tained. Integral measurements with cadmium-covered samples gave a value of (3.6 ± 2.4) × 103 b for the resonance integral of 148mPm, thereby setting an upper limit of 6000 b.