20　MeV／u^（40）Ar离子与^（238）U相互作用中的靶余核

TARGET RESODUES FROM THE INTERACTION OF NATURAL URANIUM TARGET WITH 20 MeV/NUCLEON ￣(40)Ar IONS

采用核化学技术测定了２０ＭｅＶ／ｕ^（４０）Ａｒ离子与^（２３８）Ｕ靶相互作用中靶余核的生成截面，由此得到了该反应的电荷分布和质量分布。结果表明，裂变产物源于不同的反应机制，在入射粒子能量为２０ＭｅＶ／ｕ时，对应于重靶余核的“类熔合峰”依然存在。

The production cross sections of target residues from the interaction of natural uranium with 20 MeV/nucleon￣(40)Ar ions have been measured using nuclear chemistry techniques,Charge and mass yield distributions are obtained from these data. It is proved that the process of formation of neutron-excessive nuclides is different from that of neutron-deficient products,The appearance of fusion-like peak corresponding to heavy residues at incident projectile energy of 20 MeV/nucleon is observed.