论文标题
在实验室相关等离子体中的Alfvén波参数衰减不稳定性的混合模拟
Hybrid simulation of Alfvén wave parametric decay instability in a laboratory relevant plasma
论文作者
论文摘要
大振幅Alfvén波会受到参数衰变的影响，这些衰减可能在空间，天体物理和融合等离子体中产生重要的后果。尽管几十年前预测了Alfvén波参数衰减的不稳定性，但观察证据是有限的，激发了对实验室证明不稳定性和相关数值建模的极大兴趣。在这里，我们使用逼真的波浪注入和波皮 - 血浆参数报告了实验室相关等离子体（基于大等离子体设备）中Alfvén波参数衰减不稳定性的新型混合模拟。仅考虑无碰撞阻尼，我们确定了触发有限等离子体中不稳定性所需的阈值alfvén波幅度和频率。这些阈值行为通过简单的理论考虑来证实。简要讨论了本模型中未包括的其他效果，例如有限的横向尺度和离子中性碰撞。这些混合模拟展示了一种有希望的工具，用于研究实验室Alfvén波动力学，可以为未来的实验室证明参数衰减不稳定性提供指导。
Large-amplitude Alfvén waves are subject to parametric decays which can have important consequences in space, astrophysical, and fusion plasmas. Though the Alfvén wave parametric decay instability was predicted decades ago, observational evidence is limited, stimulating considerable interest in laboratory demonstration of the instability and associated numerical modeling. Here, we report novel hybrid simulation of the Alfvén wave parametric decay instability in a laboratory relevant plasma (based on the Large Plasma Device), using realistic wave injection and wave-plasma parameters. Considering only collisionless damping, we identify the threshold Alfvén wave amplitudes and frequencies required for triggering the instability in the bounded plasma. These threshold behaviors are corroborated by simple theoretical considerations. Other effects not included in the present model such as finite transverse scale and ion-neutral collision are briefly discussed. These hybrid simulations demonstrate a promising tool for investigating laboratory Alfvén wave dynamics that can provide guidance for future laboratory demonstration of the parametric decay instability.
