Measurement of the 239Pu(n,f)/235U(n,f) Cross-Section Ratio with the NIFFTE fission Time Projection Chamber

• Published in: Nuclear data sheets Vol. 178; pp. 1 - 40
• Main Authors: Snyder, L., Anastasiou, M., Bowden, N.S., Bundgaard, J., Casperson, R.J., Cebra, D.A., Classen, T., Dongwi, D.H., Fotiades, N., Gearhart, J., Geppert-Kleinrath, V., Greife, U., Hagmann, C., Heffner, M., Hensle, D., Higgins, D., Isenhower, L.D., Kazkaz, K., Kemnitz, A., King, J., Klay, J.L., Latta, J., Leal-Cidoncha, E., Loveland, W., Magee, J.A., Manning, B., Mendenhall, M.P., Monterial, M., Mosby, S., Neudecker, D., Prokop, C., Sangiorgio, S., Schmitt, K.T., Seilhan, B., Tovesson, F., Towell, R.S., Walsh, N., Watson, T.S., Yao, L., Younes, W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2021; Elsevier
• Subjects: cross-section ratio; neutron time-of-flight (nToF); Nuclear Criticality Safety Program (NCSP); nuclear data
• ISSN: 0090-3752; 1095-9904
• DOI: 10.1016/j.nds.2021.11.001

The 239Pu(n,f)/235U(n,f) cross-section ratio has been measured with the fission Time Projection Chamber (fissionTPC) from 100 keV to 100 MeV. The fissionTPC provides three-dimensional reconstruction of fission-fragment ionization profiles, allowing for a precise quantification of measurement uncertainties. The measurement was performed at the Los Alamos Neutron Science Center which provides a pulsed white source of neutrons. The data are recommended to be used as a cross-section ratio shape. A discussion of the status of the absolute normalization and comparisons to ENDF evaluations and previous measurements is included.