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This is a drawing of the Earth's magnetosphere. The plasma sheet is highlighted in yellow.
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The Plasma Sheet

The plasma sheet is simply that, a sheet of plasma that extends down the magnetotail dividing the two lobes of the Earth's magnetic field. The particle density here is about 0.5 cm-3 for both electrons and protons. The average particle energies are 0.6 keV for the electrons and 5.0 keV for the protons.

This outer plasma is hotter than the plasma in the plasmasphere, but is considered low energy when compared to the particles in the Van Allen radiation belts. The plasma sheet is several Earth radii thick and has an inner edge at about 7 Earth radii at local midnight. Its thickness and position do vary.

Sometimes the plasma sheet is also called the current sheet because one of the main currents which circle the magnetosphere cuts through the center of the magnetotail.

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