The odd-even effect of 20Ne fragmentation cross sections

Projectile fragmentation cross sections are calculated for reactions of Ne-20 on the C, Al, Cu, Sn and Pb targets at 400 A MeV by using the improved quantum molecular dynamics model together with the statistical model code GEMINI. The improved quantum molecular dynamics model is applied to describe the dynamical process, and the GEMINI model is used to simulate the de-excitation process of excited primary fragments. It is found that the total cross sections increase as a function of the target mass, which is in good agreement with the experimental results and other theoretical predictions. The odd-even effect of the partial cross sections observed in experiments is well reproduced, which appears in the de-excitation process of the excited primary fragments as a result of pairing effect and is mainly formed in the grazing collisions. The results of isospin distributions demonstrate that the odd-even effect of partial cross sections mainly comes from the fragments with T-Z = 0, +/- 0.5.