摘要
在 30MeV/u4 0 Ar +112 ,12 4 Sn反应中用平行板雪崩计数器实现了前冲余核的测量 .在不同的线性动量转移下用运动源模型拟合了后角的3 He,α和6He能谱 ,发现3 He的能谱斜率温度在12 4 Sn系统中高于112 Sn系统 ,而6He的温度在112 Sn系统中更高 ,α粒子在两个系统中没有明显差别 .用热核粒子蒸发过程衰变道的选择性对这种同位旋相关性进行了解释 .
The coincidence measurements between residues and light particles have been carried out for the reactions 30MeV/u 40 Ar+ 112,124 Sn. The times of flight of the residues are measured by PPACs installed concentrically around the beam at forward angle. The spectra of 3He,α and 6He detected at backward angle in coincidence with residues having different average velocities are analyzed with moving source fit. The average excitation energy of hot nuclei is obtained in the incomplete fusion frame. It is shown that the slope temperature extracted from 3He( 6He) spectra is higher (lower) in the neutron-rich system 40 Ar+ 124 Sn than that in the neutron-deficient system 40 Ar+ 112 Sn. For α particle. there is almost no difference between the two reaction systems. The possible causality of these systematic behaviors is discussed from the selectivity of the emitting particles along the decay chain of hot nuclei. The calculation of GEMINI can not repsoduce the experimental observations.
出处
《高能物理与核物理》
CSCD
北大核心
2001年第7期643-650,共8页
High Energy Physics and Nuclear Physics
基金
中国科学院"百人计划"基金 ( 1998年
2 0 0 0年 )
"九五"基础性研究重大科学基金 (KJ95T - 0 3)资助&&
