Investigation of the nuclear liquid-gas phase transition in the static AMD
Investigation of the nuclear liquid-gas phase transition in the static AMD
复制标题
静态 AMD 中核液-气相变的研究
DOI：
10.1088/1361-6471/abe563
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发表时间：
2021-02
期刊：
影响因子：
--
通讯作者：
Wada R.
中科院分区：
文献类型：
--
作者：
Lin W.;Ren P.;Liu X.;Zheng H.;Huang M.;Qu G.;Wada R.
在恒定体积或恒定压力下的静态反对称分子动力学（静态 AMD）模型框架中研究核液-气相变。采用氘核四极动量涨落温度计提取Ar和Sn裂解体系的温度。对于密度 ρ ≤ 0.03 fm−3 的系统，在恒定体积下观察到热量曲线的平台结构。在研究的所有压力下，在恒定压力下观察到热量曲线明显后弯，这表明发生了一级相变。 Ar和Sn体系的热量曲线的相似行为表明在恒定体积或恒定压力下不存在强烈的体系尺寸效应。在静态 AMD 模拟中，质量分布和轻粒子多重性在低激发能下都表现出强烈的 α 聚类。应用多重导数 (dM/dT) 和 Zmax (NVZ) 归一化方差的液-气相变测量。实验热曲线还与定容和定压条件下静态 AMD 模拟的 Sn 热曲线进行了比较。讨论了可用的实验结果和静态 AMD 模拟的结果。实验温度测量和主要碎裂源重建技术中的大误差阻碍了得出相变是否发生在恒定体积或恒定压力下的结论。这项研究表明，除了热量曲线之外，还应该检查液-气相变的不同测量方法才能得出结论。
Nuclear liquid-gas phase transitions are investigated in the framework of static antisymmetrized molecular dynamics (static AMD) model under either a constant volume or a constant pressure. A deuteron quadrupole momentum fluctuation thermometer is applied to extract the temperature of fragmenting systems of Ar and Sn. A plateau structure of caloric curves is observed under a constant volume for those system with a density ρ ≤ 0.03 fm−3. A clear backbending in the caloric curves, which indicates a first order phase transition, is observed under a constant pressure with all pressures studied. The similar behavior of caloric curves of Ar and Sn systems indicates that there is no strong system size effect under a constant volume or a constant pressure. Both the mass distributions and the light particle multiplicities show a strong α clusterization at low excitation energies in the static AMD simulations. The liquid-gas phase transition measures of the multiplicity derivative (dM/dT) and the normalized variance of Zmax (NVZ) are applied. The experimental caloric curves are also compared with those of Sn of the static AMD simulations under both the constant volume and the constant pressure conditions. Discussions are presented with the available experimental results and those from the static AMD simulations. Large errors in the experimental temperature measurements and those in the reconstruction technique for the primary fragmenting source hinder to draw a conclusion whether the phase transition occurs under either a constant volume or a constant pressure. This study suggests that different measures for the liquid-gas phase transitions should be examined besides the caloric curves in order to draw a conclusion.
DOI：
10.1525/gfc.2020.20.3.53
发表时间：
2020-08
期刊：
Gastronomica
影响因子：
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作者：
Bharati Chaturvedi
通讯作者：
Bharati Chaturvedi