空间科学学报2025，Vol.45Issue(1)：56-65,10.DOI:10.11728/cjss2025.01.2024-yg29
波模并合激发谐频脉泽辐射的泵波模拟
Simulation on the Mechanism of Harmonic Maser Emission Through the Wave Coalescence Process
摘要
Abstract
Electron Cyclotron Maser Emission(ECME)driven by electrons with loss-cone distribution is the main mechanism for explaining solar radio spikes.However,in strongly magnetized plasmas,the losscone-driven ECME mainly generates fundamental X mode emissions,which can be efficiently ab-sorbed when escaping through the second-harmonic layer in the solar corona.To solve the"escaping dif-ficulty",recent studies suggested a new mechanism of harmonic maser emission(X2)involving nonlinear wave coupling process of Z-mode and fundamental X-mode(X1)waves(Z+Z→X2,Z+X1→X2).It is necessary to verify the nonlinear wave coalescence process with theoretical analyses and numerical simu-lations.Here,the possibility of a nonlinear wave coupling process is examined via solving the matching conditions for three-wave resonant interaction based on the dispersion relation of cold plasma in magne-to-ionic theory.The matching conditions for the Z and/or X1 waves were found to be satisfied over a wide range of parameters,leading to the production of X2 emissions that propagate perpendicularly and obliquely relative to the direction of the background magnetic field.Based on the solutions obtained in the matching condition analysis,we selected four sets of solutions of Z+Z and Z+X1 to perform particle-in-cell simulations using wave pumping method,to verify the nonlinear process of wave coalescence gen-erating second harmonic X-mode emissions.With X1 and/or Z modes correctly pumped in the simula-tion domain,efficient generation of X2 emissions was observed,with saturation achieved within 400Ωce-1.The conversion rate of energies of X2 emissions to Z mode waves varies from 2%to 8%.The study presents strong evidence to support the new mechanism of harmonic maser emission,which can be wide-ly applied to explain the solar and space radio emissions.关键词
相干辐射机制/PIC模拟/太阳射电辐射/非线性过程Key words
Coherent emission mechanism/PIC simulation/Solar radio emission/Nonlinear process分类
地球科学引用本文复制引用
刘功林,宁昊,倪素兰,李传洋,张子龙,李耀坤,陈耀..波模并合激发谐频脉泽辐射的泵波模拟[J].空间科学学报,2025,45(1):56-65,10.基金项目
国家自然科学基金项目(12203031,12103029),中国博士后科学基金项目(2022TQ089)和山东省自然科学基金项目(ZR2021QA033,ZR2023QA141)共同资助 （12203031,12103029）
