Field‐aligned electron precipitation at the edge of an arc
Field‐aligned electron precipitation at the edge of an arc
复制标题
电弧边缘的场对准电子沉淀
DOI：
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发表时间：
1986
期刊：
影响因子：
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通讯作者：
M. Boehm
中科院分区：
文献类型：
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作者：
J. Mcfadden;C. Carlson;M. Boehm
在一个安静的午后极光弧线上，火箭探测飞行，测量到了弧线边缘的场向电子。高时间分辨率测量显示了电子分布函数在2.3公里宽的场定向降水上的演变。在很宽的平行能量范围内(100-900 eV)，这些场定向通量的垂直温度几乎是恒定的。较小的垂直温度表明加速区位于较低的高度。检验了两种冷等离子体对流进入V型位势结构边缘的模式，发现它们与观测到的边缘降水的通量和空间宽度都是一致的。这两个模型都预测平均源等离子体密度低于130/cm³，以解释观测到的场向通量，因此加速区远高于1000公里。
Measurements of field-aligned electrons at the edge of an arc are presented from a sounding rocket flight through a quiet afternoon auroral arc. High time resolution measurements show the evolution of the electron distribution function over the 2.3-km width of field-aligned precipitation. A nearly constant 1.2-eV perpendicular temperature was found for these field-aligned fluxes over a broad range of parallel energies (100–900 eV). The small perpendicular temperature indicates that the acceleration region is located at a low altitude. Two models of cold plasma convection into the edge of a V-shaped potential structure are examined and found consistent with both the observed fluxes and spatial width of the edge precipitation. Both models predict an average source plasma density less than 130/cm³ to account for the observed field-aligned fluxes and thus an acceleration region well above 1000 km.