...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Annales Geophysicae >Electron velocity distribution function in a plasma with temperature gradient and in the presence of suprathermal electrons: application to incoherent-scatter plasma lines
【24h】

Electron velocity distribution function in a plasma with temperature gradient and in the presence of suprathermal electrons: application to incoherent-scatter plasma lines

机译：具有温度梯度且存在超热电子的等离子体中的电子速度分布函数：应用于非相干散射等离​​子体线

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The plasma dispersion function and thereduced velocity distribution function are calculated numerically for anyarbitrary velocity distribution function with cylindrical symmetry along themagnetic field. The electron velocity distribution is separated into twodistributions representing the distribution of the ambient electrons and thesuprathermal electrons. The velocity distribution function of the ambientelectrons is modelled by a near-Maxwellian distribution function in presence ofa temperature gradient and a potential electric field. The velocity distributionfunction of the suprathermal electrons is derived from a numerical model of theangular energy flux spectrum obtained by solving the transport equation ofelectrons. The numerical method used to calculate the plasma dispersion functionand the reduced velocity distribution is described. The numerical code is usedwith simulated data to evaluate the Doppler frequency asymmetry between the up-and downshifted plasma lines of the incoherent-scatter plasma lines at differentwave vectors. It is shown that the observed Doppler asymmetry is more dependenton deviation from the Maxwellian through the thermal part for high-frequencyradars, while for low-frequency radars the Doppler asymmetry depends more on thepresence of a suprathermal population. It is also seen that the full evaluationof the plasma dispersion function gives larger Doppler asymmetry than the heatflow approximation for Langmuir waves with phase velocity about three to sixtimes the mean thermal velocity. For such waves the moment expansion of thedispersion function is not fully valid and the full calculation of thedispersion function is needed.Key words. Non-Maxwellian electron velocitydistribution · Incoherent scatter plasma lines · EISCAT · Dielectric responsefunction
机译：对于沿磁场呈圆柱对称的任意速度分布函数，数值计算了等离子体弥散函数和由此产生的速度分布函数。将电子速度分布分为代表环境电子和超热电子分布的两个分布。在存在温度梯度和势电场的情况下，通过近麦克斯韦分布函数对环境电子的速度分布函数进行建模。超热电子的速度分布函数是通过求解电子的传输方程而获得的角能通量谱的数值模型得出的。描述了用于计算等离子体弥散函数和降低的速度分布的数值方法。数值代码与模拟数据一起使用，以评估在不同波矢处非相干散射等离​​子体线的上移和下移等离子体线之间的多普勒频率不对称性。结果表明，对于高频雷达，观测到的多普勒不对称性更依赖于麦克斯韦通过热部分的偏离，而对于低频雷达，多普勒不对称性更多地取决于超热种群的存在。还可以看到，与相速度约为平均热速度三到六倍的朗缪尔波的热流逼近相比，对等离子体弥散函数的全面评估具有更大的多普勒不对称性。对于此类波，色散函数的矩展开并不完全有效，需要对色散函数进行完整的计算。 关键词。非麦克斯韦电子速度分布·非相干散射等离​​子体线· EISCAT·介电响应功能

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号