Measurement of cross sections and isomeric cross-section ratios for the (n,2n) reactions on 85,87Rb in energies between 13 and 15 MeV

The (n,2n) cross sections and their isomeric cross-section ratios (σ m /σ g ) in the neutron energy range 13–15 MeV have been measured for 85,87 Rb 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 3 H( d , n ) 4 He 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 85 Rb(n,2n) 84m,g Rb and 87 Rb(n,2n) 86m,g Rb 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.