环电流区能量离子分布特性研究

为了考察环电流区离子的分布情况,采用环电流粒子理论模式,对环电流中10-100 keV的离子进行了模拟研究.这个模式能够根据近地注入区外边界处离子的分布函数得出磁暴主相期间环电流中的主要成分H+,O+,He+3种离子的通量分布.计算结果分析表明,在其他条件相同的情况下,不同种类离子的通量分布的形态结构十分相似.电场强度对环电流离子通量的空间分布具有决定性的作用;晨昏电场强度越强,离子的通量越高;晨昏电场越强,环电流离子的内边界越接近地球.10keV的离子在电场相当弱的时候还是存在着连续的通量分布,但他们的形态和结构随着电场的变化有明显的变化.电场很弱时,离子分布主要集中于内外两个环带,离子通量在晨侧的更多一些,离子通量的最大值基本上是在比较靠近地球的环带上;随着电场的增强,离子分布的内外两个环带逐步合并,离子的分布逐渐靠近地球,通量分布的最大值也移动到了昏侧.环电流离子投掷角分布具有各向异性,投掷角在90°左右的时候,离子通量能达到最大值. 

Energetic Ions Flux Distribution Properties of the Earth's Ring Current Region

In order to investigate the distribution of ring currents ions, Shen and Liu＇s model of ring currents ions distribution simulation is used to research 10-100 keV ion＇s distribution property. Without calculating loss, based on the ions distribution of plasma sheets injection region and near earth injection region, we obtained the flux distribution of ring currents region main composition, such as H^＋, O^＋, He^＋, during the main phase of a magnetic storm. Different ions have the same structure of flux distribution under the same conditions. Ions flux will become intensity if the electric field improves. 10 keV energetic ions widely distribute in ring current even if electric field is considerably weak. 40 keV energetic ions and other higher energetic ions form steady flux distribution with improved electric field. And the intensity of high energetic ions （≥ 40 keV） flux will exceed thelow energetic ions relatively if the electric field is intense enough. Ions flux intensity will reach the maximum when the pitch angle is 90°.