Fusion Hindrance Factor of Heavy Nuclei Extracted from Experimental Data  

作　　者：刘祖华 周宏余 

机构地区：[1]Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 [2]China Institute of Atomic Energy, Beijing 102413

出　　处：《Chinese Physics Letters》2006年第9期2395-2398,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grants Nos 10235020 and 10235030.

摘　　要：The reactions of ^16O＋^204pb, ^82Se＋^138Ba and ^96Zr＋^124Sn lead to the same compound nucleus ^220Th. In terms of the assumption that the surviving probability is independent of entrance channel, we have extracted the fusion hindrance factor from the evaporation residue cross sections for the reactions of ^82Se＋^138 Ba and ^96Zr＋^124Sn and compared with the results calculated using a two-parameter Smoluchowski equation. The theoretical predictions are basically in agreement with the experimental data. It is found that the probability of forming a compact ^220Th is less than 10% for the reactions considered. For the systems more massive than ^220Th, fusion should be much more strongly suppressed due to the competition of quasifission with complete fusion. Understanding of this inhibition is essential to forming new superheavy nuclei.The reactions of ^16O＋^204pb, ^82Se＋^138Ba and ^96Zr＋^124Sn lead to the same compound nucleus ^220Th. In terms of the assumption that the surviving probability is independent of entrance channel, we have extracted the fusion hindrance factor from the evaporation residue cross sections for the reactions of ^82Se＋^138 Ba and ^96Zr＋^124Sn and compared with the results calculated using a two-parameter Smoluchowski equation. The theoretical predictions are basically in agreement with the experimental data. It is found that the probability of forming a compact ^220Th is less than 10% for the reactions considered. For the systems more massive than ^220Th, fusion should be much more strongly suppressed due to the competition of quasifission with complete fusion. Understanding of this inhibition is essential to forming new superheavy nuclei.

关 键 词：CROSS-SECTIONS SUPERHEAVY NUCLEI DINUCLEAR-SYSTEM QUASI-FISSION MASSIVENUCLEI COLD-FUSION BARRIER PROBABILITY COMPETITION MODEL 

分 类 号：O571.44[理学—粒子物理与原子核物理]