1. Measurement of the normalized U238(n,f)/U235(n,f) cross section ratio from threshold to 30 MeV with the NIFFTE fission Time Projection Chamber
- Author
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D. Higgins, N. S. Bowden, N. Hertel, F. Tovesson, D. Hensle, L. Yao, B. Wendt, C. Brune, W. Younes, K. T. Schmitt, L. D. Isenhower, M. Heffner, J. Ruz, H. Qu, N. Walsh, U. Hager, T. Classen, J. Baker, E. Guardincerri, J. S. Barrett, J. King, S. Sangiorgio, A. B. Laptev, D. A. Cebra, S. Sharma, M. Lynch, B. Seilhan, V. Geppert-Kleinrath, W. S. Lynn, M. Cunningham, R. Meharchand, R. S. Towell, L. Wood, T. Hill, S. Stave, A. C. Tate, W. Loveland, G. Tatishvili, S. Grimes, T. N. Massey, L. Snyder, J. Bundgaard, B. Manning, J. L. Klay, U. Greife, S. Watson, J. A. Magee, J. Gearhart, D. M. Asner, I. Ferguson, C. McGrath, J. Deaven, D. E. Towell, R. G. Baker, L. Montoya, D. L. Duke, C. Hagmann, R. Kudo, N. Kornilov, E. Burgett, R. T. Thornton, M. P. Mendenhall, R. J. Casperson, and N. T. Pickle
- Subjects
Nuclear physics ,Normalization (statistics) ,Physics ,Time projection chamber ,010308 nuclear & particles physics ,Fission ,Ionization ,0103 physical sciences ,Neutron ,MicroMegas detector ,010306 general physics ,01 natural sciences ,Neutron temperature - Abstract
The normalized $^{238}$U(n,f)/$^{235}$U(n,f) cross section ratio has been measured using the NIFFTE fission Time Projection Chamber from the reaction threshold to $30$~MeV. The fissionTPC is a two-volume MICROMEGAS time projection chamber that allows for full three-dimensional reconstruction of fission-fragment ionization profiles from neutron-induced fission. The measurement was performed at the Los Alamos Neutron Science Center, where the neutron energy is determined from neutron time-of-flight. The $^{238}$U(n,f)/$^{235}$U(n,f) ratio reported here is the first cross section measurement made with the fissionTPC, and will provide new experimental data for evaluation of the $^{238}$U(n,f) cross section, an important standard used in neutron-flux measurements. Use of a development target in this work prevented the determination of an absolute normalization, to be addressed in future measurements. Instead, the measured cross section ratio has been normalized to ENDF/B-VIII.$\beta$5 at 14.5 MeV.
- Published
- 2018