摘要
测量了35MeV／u36Ar+112,124Sn反应中小角关联出射的中等质量碎片(IMF)约化速度关联函数．结果表明36Ar+124Sn反应系统中的约化速度关联函数在小约化速度处的反关联程度比36Ar+112Sn反应系统中的强,表现出明显的入射道依赖性．考察出射粒子对的单核子总动量时,发现这种差异主要来自于高动量粒子对的贡献．用三体弹道理论模型MENEKA分别计算了两个系统的IMF发射时标,在36Ar+112Sn反应系统中约为150fm／c,而在36Ar+124Sn反应系统中,约为120fm／c．同位旋相关的量子分子动力学计算表明,36Ar+124Sn系统中IMF的发射时间谱比36Ar+112Sn系统略有前移,相应地,其中心密度从最高点随时间的下降亦比36Ar+112Sn系统略快．
The reduced velocity correlation functions of the Intermediate Mass Fragments （IMFs） were measured in the reactions of ^36Ar＋^112,^124Sn at 35MeV/u. The anti-correlation at small reduced velocities is more pronounced in ^36Ar＋^124Sn system than that in ^36Ar＋^112Sn system. The difference of the correlation functions between the two reactions is mainly contributed by the particle pairs with high momenta. A three-body Coulomb repulsive trajectory code （MENEKA） is employed to calculate the emission time scale of IMFs for the both systems. The time scale is 150fm/c in the ^36Ar＋^112Sn system and 120fm/c in the ^36Ar＋^124Sn system, respectively. A calculation based on an Isospin dependence Quantum Molecular Dynamics code （IQMD） reveals that the emission time spectrum of IMFs is shifted slightly leftwards in ^36Ar＋^124Sn compared with that in the ^36Ar＋^112Sn system, indicating a shorter emission time scale. Correspondingly, the central density of the hot nuclei decreases faster in ^36Ar＋^124Sn than in ^36Ar＋^112Sn.
出处
《高能物理与核物理》
CSCD
北大核心
2007年第4期350-356,共7页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金(10205020
19575055
10175081)
国家重点基础研究发展规划项目(G2000077401)
中国科学院知识创新工程方向性项目(KJCX2-SW-N18)资助~~
关键词
中等质量碎片
关联函数
发射时标
同位旋
intermediate mass fragment, correlation function, emission time scale~ isospin
