用QMD模型研究晕核^(11)Be+^(208)Pb的熔合机制  

Study of Fusion Mechanism of Halo Nuclear ^(11)Be+^(208) Pb by Applying QMD Model

作　　者：王宁[1] 李祝霞[1] 

机构地区：[1]中国原子能科学研究院

出　　处：《高能物理与核物理》2001年第5期399-404,共6页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金!资助 ( 1 99750 73 )&&

摘　　要：通过用QMD模型研究晕核 11Be + 2 0 8Pb的近垒熔合反应 ,发现晕核引起的熔合反应中 ,并存着两种相互竞争的机制 :一方面当入射晕核 11Be靠近靶核时 ,由于 11Be是弱束缚体系 ,与靶核的相互作用可使其很容易破裂或少数核子被靶核俘获形成核子转移反应 ,从而对于熔合表现出压制 ;另一方面当 11Be的少数中子进入靶核并与靶核相互作用而使得靶核有些激发 ,而使局部半径增大 ,导致熔合势垒降低 ,熔合截面增强 .用QMD模型计算出的熔合截面与实验值基本符合 。We have studied the fusion reaction for 11 Be+ 208 Pb near barrier by applying QMD model, and find taht in the fusion reaction induced by halo nuclei there simultaneously exist two mechanisms competing with each other. On one hand, 11 Be is a weakly bound nuclear system and is easily broke up caused by the interaction with target, when it approaches to target, so the fusion cross section is suppressed. On the other and, several neutrons of 11 Be transfer into 208 Pb and interact with 208 Pb to cause the local radius of 208 Pb increase and result in an enhancement of fusion cross section. The fusion cross sections calculatd show an enhancement near barrier, and the calculated results agree with the experimental data reasonably well.

关 键 词：晕核 熔合机制 势垒 Bell Pb208 QMD模型 放射性核束 中子晕 靶核 重离子碰撞 

分 类 号：O571[理学—粒子物理与原子核物理]