环形激光辐照驱动的螺旋喷流
Helical jets driven by a ring of laser irradiation
AI总结：
本研究利用OMEGA激光装置参数，通过环形能量递增的激光脉冲，经三维磁流体动力学模拟生成高螺旋度等离子体喷流，为天体物理螺旋等离子体结构研究提供可控实验平台。
AI中文摘要：
在多种天体物理系统中，当等离子体从源处快速喷射时会形成等离子体喷流，其中一部分喷流是磁化的且具有螺旋结构。本研究证明，可利用一系列环形激光脉冲形成螺旋喷流，这些脉冲依次入射到平面箔上且能量逐渐增加。基于OMEGA激光装置参数设定条件，通过一组三维磁流体动力学模拟研究了喷流的形成过程及其包括动力学螺旋度在内的特性。研究发现，在实际实验条件下，相比均匀喷流，本方法可产生螺旋度更高的喷流。从模拟数据计算得到的合成X射线和汤姆孙散射诊断结果表明，螺旋喷流在形态和等离子体参数上提供了独特的特征。该实验室螺旋喷流平台可实现对螺旋等离子体结构动力学的可控实验研究，且通过与其他喷流或靶标的相互作用，还可开展与天体物理喷流和环境云或侧风相互作用相关的剪切驱动湍流和混合研究。
英文摘要：
Plasma jets are formed in various astrophysical systems as plasma is rapidly ejected from a source, with a subset of these jets being magnetized and having a helical structure. Here, we demonstrate that helical jets may be formed using a ring of laser pulses that arrive on planar foils sequentially with increasing energy. The formation of the jets and their properties, including kinetic helicity, are studied through a set of three-dimensional magneto-hydrodynamics simulations with conditions informed by the parameters of the OMEGA laser facility. We find that jets with a higher degree of helicity may be generated under realistic experimental conditions when compared to a uniform jet. Synthetic x-ray and Thomson scattering diagnostics computed from simulated data demonstrate that the helical jet provides a unique fingerprint in both its morphology and plasma parameters. This laboratory helical jet platform may allow for controlled experimental study of the dynamics of helical plasma structures and, through interaction with other jets or targets, can allow for studies of shear-driven turbulence and mixing relevant to interactions between astrophysical jets and ambient clouds or crosswind.
