Lower hybrid (LH) and magneto-sonic (MS) waves are well known modes of magnetized plasma. These modes play important roles in many phenomena. The lower hybrid wave is often employed in magnetic confinement fusion experiments for current drive and heating purposes. Both LH and MS waves are observed in various astrophysical and space plasma observations. These waves involve ion motion and have not therefore been considered in high power pulsed laser experiments. This paper shows, with the help of Particle - In - Cell (PIC) simulations, a simple mechanism for excitation of lower hybrid and magnetosonic excitations in the context of laser plasma interaction. A detailed study characterising the formation and propagation of these modes have been provided. The scheme for generating these perturbations relies on the application of a strong magnetic field in the plasma to constrain the motion of lighter electron species in the laser electric field. The magnetic field strength is chosen so as to leave the heavier ions un-magnetized at the laser frequency. This helps in the excitation of the LH waves. On the other hand at the slower time scale associated with the laser pulse duration, even the ions show a magnetized response and magnetosonic excitations are observed to get excited.

中文翻译：

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激光等离子体相互作用中低混合和磁声波扰动的激发

低混合 (LH) 和磁声 (MS) 波是众所周知的磁化等离子体模式。这些模式在许多现象中发挥着重要作用。较低的混合波通常用于磁约束聚变实验，用于电流驱动和加热目的。在各种天体物理和空间等离子体观测中都观察到 LH 和 MS 波。这些波涉及离子运动，因此在高功率脉冲激光实验中没有考虑。本文借助 Particle - In - Cell (PIC) 模拟，展示了一种在激光等离子体相互作用背景下激发较低混合和磁声激发的简单机制。已经提供了表征这些模式的形成和传播的详细研究。产生这些扰动的方案依赖于在等离子体中施加强磁场来限制较轻电子物种在激光电场中的运动。选择磁场强度以使较重的离子在激光频率下未被磁化。这有助于激发 LH 波。另一方面，在与激光脉冲持续时间相关的较慢时间尺度上，即使离子也显示出磁化响应，并且观察到磁声激发被激发。