Debayle A, Tikhonchuk V T
Centre Lasers Intenses et Applications, Université Bordeaux 1, CNRS, CEA, 351, Cours de la Libération, 33405 Talence Cedex, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Dec;78(6 Pt 2):066404. doi: 10.1103/PhysRevE.78.066404. Epub 2008 Dec 12.
High-intensity laser-matter interaction is an efficient method for high-current relativistic electron beam production. At current densities exceeding a several kA microm{-2} , the beam propagation is maintained by an almost complete current neutralization by the target electrons. In such a geometry of two oppositely directed flows, beam instabilities can develop, depending on the target and the beam parameters. The present paper proposes an analytical description of the filamentation instability of an electron beam propagating through an insulator target. It is shown that the collisionless and resistive instabilities enter into competition with the ionization instability. This latter process is dominant in insulator targets where the field ionization by the fast beam provides free electrons for the neutralization current.
高强度激光与物质相互作用是产生高电流相对论电子束的一种有效方法。在电流密度超过几kA/μm²时，束流的传播通过靶电子几乎完全中和电流来维持。在这种两个相反方向流的几何结构中，取决于靶和束流参数，束流不稳定性可能会发展。本文提出了对通过绝缘体靶传播的电子束丝状不稳定性的一种解析描述。结果表明，无碰撞不稳定性和电阻性不稳定性与电离不稳定性相互竞争。后一过程在绝缘体靶中占主导地位，其中快电子束的场致电离为中和电流提供自由电子。
