Determining the Np(,) cross section using the surrogate ratio method

Czeszumska, A.*; Angell, C.; Burke, J. T.*; Scielzo, N. D.*; Norman, E. B.*; Austin, R. A. E.*; Boutoux, G.*; Casperson, R. J.*; Chodash, P.*; Hughes, R. O.*; et al.

Physical Review C, 87(3), p.034613_1 - 034613_6, 2013/03

AA2012-0918.pdf:0.85MB

https://doi.org/10.1103/PhysRevC.87.034613

Neutron-induced fission cross section data are needed in various fields of applied and basic nuclear science. However, cross sections of short-lived nuclei are difficult to measure directly due to experimental constraints. The first experimental determination of the neutron-induced fission cross section of Np at non-thermal energies was performed. The Surrogate Ratio Method (SRM) was employed to indirectly deduce the Np(,) cross section. The surrogate reactions used were U and U with the reference cross section given by the well-known Np(,) cross section. The ratio of observed fission reactions resulting from the two formed compound nuclei, Np and Np, was multiplied by the directly-measured Np(,) cross section to determine theNp(,) cross section. The Np(,) cross section was determined with an uncertainty ranging between 3 - 30% over the energy range of 0.2 - 20 MeV.