发表机构
Shanghai Jiao Tong University（上海交通大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在EPOCH粒子模拟框架中开发了准圆柱方向分裂无色散求解器，可自洽处理轴子-光子耦合，消除了轴向群速度误差，降低了计算成本，实现了轴子-光子物理的准三维无色散模拟。
AI 中文摘要
我们为开源EPOCH粒子模拟框架开发了一种准圆柱方向分裂（QDS）无色散麦克斯韦求解器。该方法通过以cΔt=Δx的偏移量平流输运横向输运变量，为所有保留的方位模式保留精确的轴向相速度。基于相同的输运观点，我们构建了一种轴子求解器，该求解器在QDS求解器中推进克莱因-戈登方程和轴子再生的电磁场，从而自洽地处理轴子-光子耦合。基准测试表明，圆柱型QDS求解器重现了标准Yee尾场结构，同时消除了轴向群速度误差，并将计算成本降低了数个数量级。在双色激光混合的共振轴子产生测试中，QDS求解器消除了虚假真空源项并保持相位匹配，而Yee求解器因数值色散遭受快速相位失配。因此，所提出的算法可实现激光-等离子体相互作用中轴子-光子物理的准三维模拟，且激光输运无色散。
英文摘要
We develop a quasi-cylindrical direction-splitting (QDS) dispersionless Maxwell solver for the open-source EPOCH particle-in-cell framework. The method preserves the exact axial phase velocity for every retained azimuthal mode by advecting transverse transport variables with the $cΔt=Δx$ shift. Building on the same transport viewpoint, we formulate an axion solver that advances the Klein--Gordon equation and the axion-regenerated electromagnetic fields within the QDS solver, so that axion--photon coupling is handled self-consistently. Benchmarks demonstrate that the cylindrical QDS solver reproduces the standard Yee wakefield structure while removing the axial group-velocity error and reducing computational cost by orders of magnitude. In the resonant axion generation test via two-color laser mixing, the QDS solver eliminates the spurious vacuum source term and maintains phase matching, whereas the Yee solver suffers from rapid dephasing due to numerical dispersion. The proposed algorithm therefore enables quasi-3D simulations of axion--photon physics in laser-plasma interaction with dispersion-free laser transport.
