LAUSR

Abstract The (n,2n) cross sections and their isomeric cross-section ratios (σm/σg) in the neutron energy range 13–15 MeV have been measured for 85,87Rb by an activation and off-line γ-ray spectrometric technique using the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The natural Rb samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The neutrons were produced via the 3H(d,n)4He reaction. The pure cross section of the ground-state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. The 85Rb(n,2n)84m,gRb and 87Rb(n,2n)86m,gRb reaction excitation functions and their isomeric cross-section ratios were also calculated theoretically using the TALYS-1.8 code with different level density options. Results are discussed and compared with the corresponding literature data.