Abstract In order to accurately model implosion hydrodynamics in a radiation-hydrodynamics code, it is essential to include accurate accounting for energy deposition physics. In inertial confinement fusion (ICF), where capsules are driven by lasers or laser-driven x-rays, energy deposition profiles and energy transport have a strong impact on the development and evolution of capsule dynamics and hydrodynamic instabilities. Nevertheless, accurately modeling laser beam propagation in radiation-hydrodynamics codes presents unique challenges associated with disparate resolution requirements, the potential to seed spurious noise in highly unstable systems, and computational expense. We discuss a new method for coupling laser ray-tracing physics to a radiation hydrodynamics code, developed in the process of implementing the Mazinisin laser ray-trace into the xRAGE radiation hydrodynamics code. In contrast to previous approaches, in which laser ray-tracing is performed on the radiation-hydrodynamics mesh, our method involves a mesh generation and evolution strategy that addresses the unique requirements of the laser ray-trace in a separate mesh, enabling performance enhancements and strategies to reduce noise seeded by the discretization of beams into computational rays. In addition, we have employed several methods to ensure that spurious mesh imprinting is minimized. These involved optimizing the laser and radiation-hydrodynamics meshes as well as interpolation between them and requires the use of an exact initialization method for the radiation-hydrodynamics mesh. These techniques have enabled efficient computation of laser-driven implosions and other experiments with minimal introduction of spurious noise.

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将激光物理与辐射流体动力学耦合

摘要 为了在辐射流体动力学代码中准确地模拟内爆流体动力学，必须准确考虑能量沉积物理。在惯性约束聚变 (ICF) 中，胶囊由激光或激光驱动的 X 射线驱动，能量沉积剖面和能量传输对胶囊动力学和流体动力学不稳定性的发展和演变有很大影响。然而，在辐射流体动力学代码中准确模拟激光束传播带来了与不同分辨率要求、在高度不稳定系统中产生虚假噪声的可能性以及计算费用相关的独特挑战。我们讨论了一种将激光射线追踪物理耦合到辐射流体动力学代码的新方法，在将 Mazinisin 激光射线追踪应用到 xRAGE 辐射流体动力学代码的过程中开发。与之前在辐射流体动力学网格上执行激光光线追踪的方法相比，我们的方法涉及网格生成和演化策略，该策略解决了单独网格中激光光线追踪的独特要求，从而实现了性能增强和通过将光束离散化为计算射线来减少噪声的策略。此外，我们采用了多种方法来确保最大限度地减少虚假网格印记。这些包括优化激光和辐射流体动力学网格以及它们之间的插值，并且需要对辐射流体动力学网格使用精确的初始化方法。