Measurements of 27Al(γ, n) reaction using quasi-monoenergetic γ beams from 13.2 MeV to 21.7 MeV at SLEGS∗

The accurate photoneutron cross section of the 27Al nucleus has an important impact on clarifying the dif-ferences in existing experimental data and improving the precision of the calculation of the nuclear reactionrate of 26Al in nuclear astrophysics. The photoneutron cross sections for the 27Al(γ, n)26Al reaction, withinthe neutron separation energy of 13.2 to 21.7 MeV, have been meticulously measured with a new flat efficiencydetector (FED) array at the Shanghai Laser-Electron Gamma Source (SLEGS). The uncertainty of the data arecontrolled below 4% throughout the process and inconsistency between the present data and the existing datafrom different sources of gamma, as well as the TENDL-2021 data, is discussed in detail. These discussionsprovide a reference and help solve the inconsistency of the data of the 27Al(γ, n)26Al cross section and improvethe related theoretical calculation.