New Aspects of the Equilibrium and Dynamics of Collisionless Current Sheets

电流片对于几乎所有等离子体系统的结构和动力学都具有巨大的重要性。在太空和天体物理等离子体中，它们在许多活动现象中发挥着至关重要的作用。电流片尤其与存储的磁能的释放以及通过诸如磁重联等过程将其转换成其他形式的能量(例如，动能和/或热能)有关。在任何涉及电流片的物理过程的研究中，明智的第一步是找到适当的平衡解。无碰撞等离子体平衡理论已经确立，但在过去的几年里，人们对寻找具有特殊性质的电流片的平衡分布函数重新产生了兴趣，例如，在电流密度与磁场平行的情况下(无力电流片)。这种兴趣是由于科学好奇心和对空间和天体物理等离子体的潜在应用的结合，例如对在太阳风中观察到的结构的应用(例如，见Neukirch等人，2020)。该项目将集中于无作用力无碰撞电流片理论中的公开问题和新的方面，包括但不限于，精确中性和准中性平衡电流片之间的联系，寻找自洽无碰撞无作用力电流片解的不同方法的研究(例如，见Allanson等人，2015,2016；参考文献：Allanson，O.D.，Neukirch，T.，Wilson，F.和Troscheit，S.，Phys.等离子体22,102116(2015年)Allanson，O.D.，Neukirch，T.，Troscheit S.和Wilson，F.，J.等离子体物理。82,905820306(2016年)Neukirch，T，Vasko，I.Y，Artemyev，A.V.和Allanson，O.D.，占星学。J.891，86(2020)Wilson，F.，Neukirch，T.和Allanson，O.D.，J.等离子体物理。84,905840309(2018年)

Current sheets have huge importance for the structure and dynamics of almost all plasma systems. In space and astrophysical plasmas, they play a crucial role in many activity phenomena. Current sheets are in particular associated with the release of stored magnetic energy and its conversion into other forms of energy (e.g., kinetic energy and/or thermal energy) by processes such as magnetic reconnection.This project will focus on current sheets in collisionless plasma systems. A sensible first step in any investigation of physical processes involving current sheets is to find appropriate equilibrium solutions. The theory of collisionless plasma equilibria is well established, but over the past few years there has been a renewed interest in finding equilibrium distribution functions for current sheets with particular properties, for example for cases where the current density is parallel to the magnetic field (force-free current sheets). This interest is due to a combination of scientific curiosity and potential applications to space and astrophysical plasmas, for example to structures observed in the solar wind (see e.g., Neukirch et al., 2020).The project will focus on open questions in and novel aspects of the theory of force-free collisionless current sheets including, but not limited to, the link between exactly neutral and quasi-neutral equilibrium current sheets, the investigation of different methods to find self-consistent collisionless force-free current sheet solutions with plasma beta values below unity (see e.g., Allanson et al., 2015,2016; Wilson et al., 2018) and the stability of such current sheets.References:Allanson, O.D., Neukirch, T., Wilson, F. and Troscheit, S., Phys. Plasmas 22, 102116 (2015)Allanson, O.D., Neukirch, T., Troscheit, S. and Wilson, F., J. Plasma Phys. 82, 905820306 (2016)Neukirch, T, Vasko, I.Y, Artemyev, A.V. and Allanson, O.D., Astrophys. J. 891, 86 (2020)Wilson, F., Neukirch, T. and Allanson, O.D., J. Plasma Phys. 84, 905840309 (2018)