Astrophysical Dense Plasmas in Degenerate Stars

天体物理学上的凝聚等离子体包括在中子星、白色矮星、太阳、棕矮星和巨行星等天体的内部、表面和外层中发现的凝聚等离子体。在本科学研究计划中研究的基本过程包括与原子跃迁、电子传导、辐射转移、能量产生和耗散以及核过程有关的过程。这些物理过程的速率敏感地取决于等离子体状态的变化，例如冷冻转变、化学分离、超临界流体、电离或绝缘体到金属的转变，以及由密度压缩和/或温度变化引起的磁转变。因此，状态方程和相图的构建问题与这些基本过程以及简并恒星（如白色矮星和巨行星）的结构、演化和动力学的理论理解密切相关。具体阐明的是：A.热核和浓缩核反应：致密恒星物质中固体浓缩核速率的热增强;高气压金属中增强的浓缩核反应B.传输过程：具有绝缘体到金属跃迁和对流传输的状态方程;具有电离跃迁的致密高Z材料的电和热膨胀率;具有电离跃迁的致密材料的辐射不透明度C.相变：对凝聚等离子体中冻结转变的量子蒙特卡罗模拟研究;流体-固体相界和化学分离;致密物质中绝缘体-金属转变D.恒星地震学：磁星中的非径向振荡;碰撞彗星激发木星振荡;通过声传播探测太阳结构

Astrophysical condensed plasmas include those found in the interiors, surfaces, and outer envelopes of such astronomical objects as neutron stars, white dwarfs, the sun, brown dwarfs, and giant planets. Among the elementary processes which have been investigated in this Scientific Research Program are those related to atomic transitions, electronic conduction, radiative transfer, energy generation and dissipation as well as the nuclear processes. The rates of these physical processes depend sensitively on a change in the plasma states, such as freezing transition, chemical separation, supercritical fluids, ionization or insulator-to-metal transition, and magnetic transitions, resulting from a compression in density and/or a change in temperature. The issues on the equations of state and construction of the phase diagrams are thus intimately related to theoretical understanding of these elementary processes and of structure, evolution, and dynamics of degenerate stars, such as white dwarfs and giant planets. Specifically clarified are :A.Thermonuclear and pycnonuclear reactions : Thermal enhancement of solid pycnonuclear rates in dense stellar matter ; Enhanced pycnonuclear reactions in ultrahigh pressure metalsB.Transport processes : Equations of state with insulator-to-metal transitions and convective transport ; Electric and thermal resistivities of dense high-Z materials with ionization transition ; Radiative opacities of dense materials with ionization transitionC.Phase transitions : Quantum Monte Carlo simulation study of freezing transition in a condensed plasma ; Fluid-solid phase boundaries and chemical separation ; Insulator-to-metal transitions in dense matterD.Stellar Seismology : Non-radial oscillations in magnetic stars ; Excitation of Jovian oscillations by a colliding comet ; Probing Solar structure by acoustic propagation