对超热电子诱生的磁场分布的估算

CONFIGURATION OF MAGNETIC FIELDS INDUCED BY SUPERTHERMAL ELECTRONS

利用简化模型估算了电荷分离场及由超热电子逃逸在等离子体表面产生的自生磁场的大小和空间分布 .受电荷分离场的影响以及超热电子逃逸数的限制 ,超热电子产生的环形磁场主要分布于等离子体表面附近的焦斑半径内 ,仅当超热电子束流很强时 (在 1μm半径截面内达到kA量级 ) ,环形磁场才可以达到 10 2 T量级 .一般情况下 。

Charge separation electric fields and magnetic fields induced by superthermal electrons escaped from plasmas have been evaluated using a very simple model. The magnitude and configuration of magnetic fields have been obtained. Generally, the circular-shaped magnetic fields are weak because of the charge separation electric field and the followed finite number of the escaped superthermal electrons, and they are mainly distributed in laser focus near the surface of the plasma because of the transverse motion of the escaped superthermal electrons. Only when the electron current is very strong (about kA through the cross-section with 1 mum radius),can a megagauss magnetic field be obtained.