题目：Heating and deceleration of minor ions by oblique Alfven waves in the fast solar wind

主讲：李醒 博士

时间：2009年06月19日（周五）上午10：30

地点：空间科学与物理学院三楼会议室

简介：

In the fast solar wind, ions generally have mass proportional temperatures and heavier ions flow faster than protons. The differential speed is roughly one local Alfven speed. This has been a puzzle for decades. In the past few years, theoretical studies of magnetohydrodynamic turbulence and turbulence observations have indicated the importance of obliquely propagating kinetic Alfven waves. I will briefly review this topic. We then propose that in typical fast solar wind conditions, oblique Alfven waves are able to heat minor ions via ion cyclotron and Landau resonance and decelerate them so the relative speed between these minor ions and protons can be maintained at roughly one Alfven speed. The heating of these minor ions due to Landau damping is less important because these waves have a small electric field component parallel to the background magnetic field.