磁暴主相期间外辐射带结构的变化

本文利用相对論带电粒子的两个寝渐不变量,討論了磁暴主相期間外輻射带中心結构的变化。作者认为磁暴主相是由“磁暴带”环电流所产生。“磁暴带”假設位于外輻射带中心之外,它是太阳等离子体穿入磁层后形成的。本文对初始能量W=20Kev和W=1Mev的电子分別进行了計算。 結果表明,在磁暴主相期間电子向外漂移,其赤道投擲角減小,但镜点离地面距离增高。因此,主相时所观測到的极光,并不是由于地磁場的平緩下降使小投擲角电子注入大气层而形成的。此外,計数率降低的主要原因是由于力管截面膨胀造成的粒子密度減小以及电子減速,而电子減速与投擲角有关,由此决定了电子通量沿磁力线分布的变化。以上結果与探险者6号（Explorer Ⅵ）的观測一致。

VARIATION OF THE STRUCTURE IN THE OUTER RADIATION BELT DURING THE MAIN PHASE OF A MAGNETIC STORM

By means of two adiabatic in-variants of relativistic charge particles,some variations of the structure in the outer radiation belt during the main phase of a magnetic storm are discussed. It is supposed that the main phase is caused by the ring current of the "storm belt" situated outside the centre of the radiation belt and consisted of solar plasma penetrating into the magnetosphere. The calculation had been proceeded for electrons with initial energy W=20Kev and W=1 Mev respectively. It is shown that during the main phase of a magnetic storm the electrons drift outward,the pitch angles are decreased,but the height of the mirror points is increased. This means that the excitation of aurora during the main phase can not be attributed to the precipitation of electrons into atmosphere caused by the slow change of geomagnetic field. It is also shown that the variation of counting rate during the main phase is produced primarily by the decrease of the density of electrons in accompanying with the expansion of the tubes of force and by the electrons deceleration,the changes in the dis tribution of electrons fluxes along the lines of force could explaned in terms of the deceleration related to the pitch angles. The results obtained agree fairly well with the observation by Explorer Ⅵ.