Measurement of the 23Na(n,2n) cross section in 235U and 252Cf fission neutron spectra Michal Košťál, Martin Schulc, Vojtěch Rypar, Evžen Losa, Marie Švadlenková, Petr Baroň, Bohumil Jánský, Evžen Novák, Martin Mareček and Jan Uhlíř EPJ Web Conf., 146 (2017) 04045 Published online: 13 September 2017 DOI: 10.1051/epjconf/201714604045