A substitution measurement for cross section of 65Cu(γ, n)64Cu reaction using natCu and 63Cutargets by quasi-monoenergetic γ beams at SLEGS?

Abstract: To overcome the difficulty and expensive cost for some specific isotopic targets, a substitution method was proposed to measure the cross section of (γ, n) reactions. Considering that the natural copper element (natCu) only has 63Cu and 65Cu isotopes, the 65Cu(γ, n)64Cu reaction was taken as an example to test the substitution method. Using quasi-monoenergetic γ beams provided by the Shanghai Laser Electron Gamma Source (SLEGS) of the Shanghai Synchrotron Radiation Facility (SSRF), the natCu(γ, n) was measured from Eγ= 11.09 to 17.87 MeV. Furthermore, based on the 63Cu(γ, n) reaction measured using the same experimental setup at SLEGS, the 65Cu(γ, n)64Cu was extracted using the substitution method. The abundance variation of natural copper, showing a significant influence in the cross section, is also investigated. The results were compared to the existing experimental data measured by bremsstrahlung and positron annihilation in-flight sources, and the TALYS 2.0 predictions. The γ strength function (γSF) of 65Cu is obtained from the 65Cu(γ, n) data, and the reaction cross section of 64Cu(n, γ) was further calculated.