Astrophysical Dense Plasmas in Degenerate Stars

天体物理凝聚等离子体包括在中子星、白矮星、太阳、棕矮星和巨行星等天文物体的内部、表面和外包层中发现的等离子体。在这个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依赖于等离子体状态的变化，如冻结转变、化学分离、超临界流体、电离或绝缘体到金属的转变，以及由于密度压缩和/或温度变化而产生的磁性转变。因此，关于状态方程和相图构造的问题与对这些基本过程的理论理解以及对诸如白矮星和巨行星等简并恒星的结构、演化和动力学的理解密切相关。具体阐述了：A.热核和准非核反应：致密星体中固体准非核速率的热增强；超高压金属中增强的准非核反应；B.输运过程：具有绝缘体到金属转变和对流输运的状态方程；具有电离转变的致密高Z材料的电阻率和热阻；具有电离转变的致密物质的辐射不透明度；C.相变：凝聚等离子体中冻结转变的量子蒙特卡罗模拟研究；流固相界和化学分离；致密物质中绝缘体到金属的转变；恒星地震学：磁星中的非径向振荡；碰撞彗星激发的木星振荡；声传播探测Solar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