Projectile fragmentation reactions of 40 Ar at 57 MeV/nucleon

The projectile fragmentation reactions of ${}^{40}$Ar at 57 MeV/nucleon on ${}^{9}$Be and ${}^{181}$Ta targets have been studied by the Radioactive Ion Beam Line in Lanzhou (RIBLL) at the Heavy-Ion Research Facility in Lanzhou (HIRFL). The momentum distributions of fragments have been measured and the competition between different mechanisms are observed. The production cross sections have been obtained and compared with the empirical parametrization of fragmentation cross section (EPAX), abrasion-ablation (AA), and heavy-ion phase space exploration (HIPSE) models, and the target dependence of fragment cross sections has also been discussed.