【摘要】 在5°—140°范围内测量了30MeV／u40Ar束流轰击不同靶核（58Ni、64Ni、115In）时出射的中等质量碎片的元素分布．在20°—80°之间，观察到了原子序数大于弹核原子库数的出射碎片（Z＝3—24），发现中等质量碎片的微分截面在其原子库数从小于弹核原子库数向大于弹核原子库数变化过程中是连续变化的，该角区出就碎片的元素分布与弹核原子库数关系不大．对中能区核反应的过渡性质做了讨论，指出了探测阈对所测得的元素分布的影响，并讨论了元素分布的幂指数规律.更多还原

【Abstract】 The element distribuhons of intermediate mass fragments (IMF) emitted over an angular region of 5°-140° have been measured in the reachons of 30MeV/u 40Ar + 58, 64 Ni and 115 In. Within 20°- 80° range the IMFs with Z= 3-24 were observed. The IMF production cross section changes smoothly with its charge number,and the element distribuhon changes continuously when the IMF charge number increases across the charge number of the projectile. There is no strong dependence of the element distribution on the charge number of the projectile in this angular region.The transition nature of the reaction mechanism in the intermediate energy region and the power law of the IMF element distribution,as well as the dependence of element distributions on the threshold of the detectors were discussed.更多还原