Plasmapause observations with the M.I.T. experiment on IMP 2

Abstract

The M.I.T. plasma experiment flown on the IMP 2 satellite has detected the boundary of the region of dense thermal ions in the inner magnetosphere. The location of this boundary corresponds to the knee region investigated by whistler techniques. In the dawn hemisphere the boundary assumes a nearly circular shape during times of low magnetic activity (3-hr Kp ≤ 1). An empirical relationship between the average L shell of the boundary and the 3-hr Kp index has been found to be L = 6 - 0.6 Kp.