The long-lived neptunium 236 isomer's fission cross section for thermal neutrons

Conflicting findings on the correlations between fission cross section and target-nucleus spin for several nuclei, viz., a large cross section corresponding to a high spin, prompted the authors to verify such a correlation by repeating the measurement of the familiar fission cross section of Np 236 (zeta) by using analogous methods of chemical purification of the substance and identification of the fragments as were used in the case of Np(s) 236