Liquid–gas phase transition in nuclear matter
Liquid–gas phase transition in nuclear matter
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DOI：
10.1038/305410a0
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发表时间：
1983-09
期刊：
影响因子：
64.8
通讯作者：
P. Siemens
中科院分区：
文献类型：
--
作者：
P. Siemens
每种自束缚费米液体在低温下都会表现出液-气相平衡，因为由于简并动能，压力在低密度下为正，并在平衡密度下再次降至零。然而，在两相平衡条件下很少发现核物质：在通常的核反应中，会产生一个加热的（“化合物”）核，其周围环境的温度要低得多，不平衡。最常见的两相平衡例子发生在中子滴线1内的中子星地壳中，温度低于一兆电子伏。在超新星中，在内爆逆转为爆炸的关键时刻，可能会达到与中子星相当的密度，相关温度可达 5 至 10 MeV。准确了解这些条件下核物质的性质对于理解超新星动力学至关重要。本次通讯展示了如何利用最新一代核加速器的实验室观察来推断核物质中液-气界面的表面张力——这是状态方程的一个重要组成部分，但目前还没有可靠的理论模型。
Every self-bound Fermi liquid will exhibit a liquid–gas phase equilibrium at low temperatures, because the pressure is positive at low densities due to the kinetic energy of degeneracy, and falls to zero again at the equilibrium density. Nuclear matter is seldom found under conditions of two-phase equilibrium, however: in usual nuclear reactions, a heated (‘compound’) nucleus is produced out of equilibrium with its surroundings, which are at a much lower temperature. The most familiar example of a two-phase equilibrium occurs in the crust of neutron stars inside the neutron-drip line1, at temperatures of less than an MeV. In supernovas, in the crucial moments when the implosion is reversed to an explosion, densities comparable to those of neutron stars may be attained with associated temperatures of 5 to 10 MeV. An accurate knowledge of the properties of nuclear matter under these conditions is essential to the understanding of supernova dynamics2. This communication shows how laboratory observations with the latest generation of nuclear accelerators can be used to infer the surface tension of the liquid–gas interface in nuclear matter–an essential ingredient of the equation of state for which a reliable theoretical model is not available.