Projectile fragmentation cross sections are calculated for reactions of 20 Ne 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.

Projectile fragmentation cross sections are calculated for reactions of and on C, Al, Cu, and Pb targets at 400 A MeV by using the improved quantum molecular dynamics model, together with the statistical model code GEMINI. The total cross sections increase with increasing target mass, which is in good agreement with the experimental results and other theoretical predictions. The isotopic distributions and isospin distributions suggest that the odd–even effect is dependent on the projectile nuclei. For a projectile with , the partial cross sections appear an obvious odd–even effect, and the isotopic distributions show that the maximal cross sections for the even-Z isotope are larger than that for the neighboring odd-Z isotope. However, the fragmentation cross sections and the isotopic distributions for the projectile have not shown these characteristics. The isospin distributions show that the odd–even effect of fragments from the projectile is stronger than that from the projectile.