摘要
利用量子分子动力学模型研究了不同核温度计测量的热核温度。使用中能区的对心重离子碰撞产生平衡的热核,同时选取轻质量的弹核和重质量的靶核作为反应系统。使用上述的反应系统可以使核子发生足够多次的碰撞,从而使系统达到平衡。热核的质量数范围是190~200,不对称度(N-Z)/A范围是0.11~0.20。研究发现使用不同的核温度计时,核温度的同位旋效应存在差异。使用伽马光子温度计时,丰中子系统的温度较高。丰中子系统的温度比缺中子系统的温度高大约为0.1 MeV。使用斜率温度计时,缺中子系统的温度较高,缺中子系统的温度比丰中子系统的温度高大约0.2 MeV。由于斜率温度计会受到发射粒子的库仑效应、反冲效用以及费米动能的影响,因此需要进一步研究核温度计的物理特性,从而更加精确的提取重离子碰撞中产生的热核温度。
In this paper,we study the nuclear temperatures by different thermometer via the isospin-dependent quantum molecular dynamics model.The hot nuclei are produced by small mass projectiles and great mass targets.Since in such reaction system there are enough nucleons in the overlap volume of target and projectile to experience enough collisions needed for thermalization to take place.In order to decrease the mass effect on the nuclear temperatures,only events having the mass of the hot nuclei 190~200 and asymmetry of the hot nuclei 0.11~0.20 are used to study the isospin dependence of the nuclear temperatures.We find that the isospin dependence of the nuclear temperature is different for different thermometer.Using the thermal-photon thermometer,the temperatures are higher for neutron-rich system.The temperatures divergence is about 0.1 MeV.However,the temperatures are higher for neutron-poor system by slope thermometer.The temperatures divergence is about 0.2 MeV.Since the slope thermometer is affected by the coulomb effect,recoil effect and Fermi kinetic energy of the emitted particles,it is necessary to further study the physical characteristics of the nuclear thermometer,so as to more accurately extract the temperature of the hot nuclei.
作者
张凡
王鄂
关贵明
郭琛琛
吴丽娟
ZHANG Fan;WANG E;GUAN Guiming;GUO Chenchen;WU Lijuan(College of Physics Science and Technology,Shenyang Normal University,Shenyang 110034,China;Department of Electronic Information and Physics,Changzhi University,Changzhi 046011,China;Unit 31441 of the People s Liberation Army,Shenyang 110004,China;Sino-French Institute of Nuclear Engineering and Technology,Sun Yat-sen University,Zhuhai 519082,China)
出处
《沈阳师范大学学报（自然科学版）》
CAS
2019年第6期539-542,共4页
Journal of Shenyang Normal University:Natural Science Edition
基金
国家自然科学基金资助项目(11847036,11605270)
辽宁省教育厅科研基金资助项目(L2010521)
关键词
核温度
同位旋效应
动力学模型
nuclear temperature
isospin effects
dynamics model
