中国科学技术大学学报 ›› 2014, Vol. 44 ›› Issue (5): 439-443.DOI: 10.3969/j.issn.0253-2778.2014.05.009

• 原创论文 • 上一篇    下一篇

Landau阻尼和能量守恒

秦 宏   

  1. 1.中国科学技术大学近代物理系,安徽合肥 230026; 2. 哈尔滨工业大学物理系,哈尔滨 150001
  • 收稿日期:2014-05-23 修回日期:2014-05-27 出版日期:2014-05-31 发布日期:2014-05-31
  • 通讯作者: 秦宏
  • 作者简介:秦宏(通讯作者),中国科学技术大学近代物理系教授,中国科学院磁约束聚变理论中心主任.1990年毕业于北京大学空间物理学专业,1993年获得北京大学空间物理学硕士学位,1998年获得普林斯顿大学天体物理学(等离子体物理)博士学位.历任普林斯顿等离子体物理国家实验室助理研究员、副研究、研究员,并兼任普林斯顿大学天体物理系Lecturer with the rank of Professor.因在磁约束聚变理论和强流加速器物理领域的突出贡献,于2004年荣获“美国总统青年科学家工程师早期成就奖”和“美国能源部青年科学家工程师早期成就奖”;2009年入选中组部“千人计划”.近年来在国际上首先推动了等离子体物理几何理论和几何算法的研究方向,在国际一类期刊上发表论文约120篇.
  • 基金资助:
    中国科学院交叉创新团队,国家自然科学基金中日韩前瞻计划(JSPS-NRF-NSFC A3 NSFC-11261140328),教育部创新团队发展计划(IRT1190)资助.

Landau damping and energy conservation

QING Hong   

  1. 1.Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China; 2.Department of Physics, Harbin Institute of Technology, Harbin 150001, China
  • Received:2014-05-23 Revised:2014-05-27 Online:2014-05-31 Published:2014-05-31

摘要: Landau阻尼是线性Vlasov-Poisson方程所描述的无碰撞等离子体中静电振荡强度的衰减或增长.其物理本质在学术界至今一直存在争论,主流的观点认为Landau阻尼是波和粒子交换能量的结果.但是目前用来解释Landau阻尼的物理图像和线性Vlasov-Poisson方程是矛盾的,这是因为线性Vlasov-Poisson系统的动能是守恒的,电场的能量不能转化为动能.本文发展了和线性Vlasov-Poisson方程完全一致的能量关系,并证明这个能量关系在数学上就是Landau阻尼.这应该是Landau阻尼最准确的物理图像.

关键词: Landau阻尼, 能量守恒, 等离子体波

Abstract: Landau damping is a collisionless dissipation process for electrostatic plasma waves governed by the linearized Vlasov-Poisson equations. Its physical mechanism is still being debated. It is commonly believed that Landau damping is caused by the energy exchange between waves and particles. However, this picture is not compatible with the linearized Vlasov-Poisson system, because the kinetic energy of particles in the linearized Vlasov-Poisson system is conserved, and the energy of the electrical field cannot be converted into the kinetic energy for the particles. We derived an energy relation that is fully consistent with the linearized Vlasov-Poisson system. It is shown that this energy relation is an exact statement of Landau damping, and thus the most accurate physical picture for it.

Key words: Landau damping, energy conservation, plasma waves