Modernizing the Fission Basis

In 1939, Niels Bohr and John Wheeler formulated a theory of neutron-induced nuclear fission based on the hypothesis of the compound nucleus [1]. Their theory, the so-called ``Bohr hypothesis,'' is still at the heart of every theoretical fission model today and states that the decay of a compound nucleus for a given excitation energy, spin, and parity is independent of its formation [2]. We propose the first experiment to validate to 1-2{\%} absolute uncertainties the practical consequences of the Bohr hypothesis during induced nuclear fission. We will compare the fission product yields (FPYs) of the same $^{\mathrm{240}}$Pu compound nucleus produced via two different reactions (i) n$+^{\mathrm{239}}$Pu [3] and (ii) $\gamma +^{\mathrm{240}}$Pu. These high-precision FPYs measurements will be extremely beneficial for our fundamental understanding of the nuclear fission process and nuclear reactions from first principles. [1] N. Bohr and J. A. Wheeler, \textit{Phys. Rev.} \textbf{56}, 426 (1939). [2] N. Bohr, \textit{Nature}. \textbf{137}, 344 (1936). [3] M. E. Gooden et al. Nuclear Data Sheets \textbf{119, }324 (2016).