Simulation study of self-organization in plasma

我们与美国人民合作，在不同的空间尺度上调查了“自组织”现象的细节，1)我们开发了一个新的模拟程序来揭示MHD等离子体中的发电机机制。我们发现旋转等离子体的对流运动通过动能到磁能的转换形成了一个胞状结构，并形成了偶极磁场。应该强调的是，磁重联在偶极磁场结构的形成中起着重要的作用。2)我们研究了螺旋系统中有限β等离子体的结构，发现了以下有趣而重要的自组织过程即使螺旋等离子体最初是不稳定的，结构由于压力驱动的不稳定而被破坏，通过非线性相互作用…再次形成有序结构更多的离子。需要注意的是，当结构形成时，通常会产生熵，即热能。在这种情况下，热能是结构不稳定的原因，同时它也导致了有序结构。3)我们开发了一个全新的粒子模拟程序。我们为开放边界系统开发了一个全新的粒子模拟程序。我们发现了幅度比常规离子-声学双层的幅度大20多倍。在本研究中，可以指出，当结构组成时，熵产生速率最高，4)我们对MHD等离子体的自组织过程做了一个概括性的研究，其中一个结论是结构的形成是间歇性的，并且随系统能量输入方式的不同而呈现反复。此外，我们还研究了尘埃等离子体中结构的形成、聚合物在液体中结晶等各种自组织过程。现在，我们继续这方面的研究，旨在构建“自组织”的一般理论。较少

We have investigated the detail of "Self-organization" phenomena in various spatial scale in collaboration with the people in U.S., Europe and Australia.The followings are some of the successful results we got in this research project.1) We have developed a new simulation code in order to reveal the dynamo mechanism in MHD plasma.We found that the convection motion of the rotating plasma makes a cell structure and forms a dipole magnetic field through the transformation of the kinetic energy to the magnetic energy.It should be emphasized that the magnetic reconnection plays an important role in the formation of the dipole magnetic field structure.2) We have studied the structure of the finite beta plasma in the helical system and found the following interesting and important self-organization process.Even if the helical plasma is initially unstable and the structure is destroyed due to the pressure driven instability, the ordered structure is formed again through the nonlinear interact … More ion.It should be noticed that when the structure is formed, the entropy, i.e., thermal energy is generally produced.In this case, the thermal energy is the cause of the structure instability, and simultaneously it resulted in the ordered structure.3) We have developed a quite new particle simulation code for an open boundary system.We found the "Super" ion-Acoustic double layr whose amplitude is more than 20 times larger than the regular one.In this study, it can be pointed out that the entropy production rate becomes highest when the structure is made up, and the entropy expulsion mechanism plays an important role in the maintenance of the ordered structure.4) We alomost made up a general scenario of the self-organization process for MHD plasmas.One of the conclusion of this scenario is that the structure formation occurs intermittently and shows the recurrence depending on the way of energy input to the system.Besides above results, we have studied various self-organization processes such as the structure formation in a dusty plasma, or the crystallization of polymer in the liquid.Now, we continue this investigation aiming the construction of the general theory of "Self-organization". Less