Simulation of Radiation-Driven Instabilities

辐射驱动不稳定性的模拟

• 批准号: 1792537
• 金额: --
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1792537
• 关键词: Simulation; Radiation; Driven; Instabilities

Laboratory astrophysics, where laboratory experiments act as scale analogues of astrophysical objects and phenomena, is a topic of increasing research activity. To date, most laboratory astrophysics activity has concentrated on plasma physics. However, it was suggested recently that cold atomic gases could play a useful role as analogues for astrophysical systems where light interacts and propagates through highly opaque, strongly scattering media such as stellar atmospheres. There is significant interest in phenomena which arise in these systems e.g.photon bubbles, localised structures which arise due to the interplay between radiation pressure and gravity and allow stars to produce enhanced localised luminosities which exceed the usual Eddington limit. Recent theoretical work has predicted that analogues of photon bubbles could be produced in the laboratory in a cold, dense atomic gas. The theoretical models used in this work involved some simplifying assumptions e.g. diffusive light propagation in the gas due to multiple scattering and a fluid model of the atomic gas. In this project a microscopic, computational model of the light-gas interaction will be developed which describes the motion of an ensemble of atoms under the action of incident and scattered light fields. This model will allow extension of the theory of photon bubble formation to allow investigation of e.g.* finite optical depth* the role of kinetic effects* the transition from stable bubbles to turbulence* the role of optical dipole forces and their interplay with radiation pressure forcesUltimately, the model will be used to determine the conditions under which radiation-pressure driven instabilities such as photon bubbles and related phenomena could be observed in the laboratory and stimulate proof-of-principle experiments.

实验室天体物理学是研究活动日益增加的一个主题，实验室实验是天体物理物体和现象的尺度模拟。迄今为止，大多数实验室天体物理学活动都集中在等离子体物理学上。然而，最近有人提出，冷原子气体可以作为天体物理系统的类似物发挥有用的作用，在天体物理系统中，光通过高度不透明的强散射介质（如恒星大气）相互作用和传播。有显着的兴趣在这些系统中出现的现象，例如光子泡，局部结构，由于辐射压力和重力之间的相互作用而产生，并允许恒星产生增强的局部亮度超过通常的爱丁顿限制。最近的理论工作预测，在实验室中，在冷的、致密的原子气体中可以产生类似于光子泡的物质。在这项工作中使用的理论模型涉及一些简化的假设，例如，由于多重散射和原子气体的流体模型，在气体中的漫射光传播。在这个项目中，将开发一个光-气体相互作用的微观计算模型，该模型描述了入射光场和散射光场作用下原子系综的运动。该模型将允许扩展光子气泡形成的理论，以允许研究例如 *有限光学深度 * 动力学效应的作用 * 从稳定气泡到湍流的过渡 * 光学偶极力的作用及其与辐射压力的相互作用最终，该模型将用于确定辐射压力驱动的不稳定性（如光子气泡和相关现象）可在实验室中观察到的条件，并刺激原理验证实验。