Electron fluxes in the near-Earth magnetotail

In the geomagnetic tail, enhanced electron fluxes are observed mainly in the plasma sheet and in the plasma sheet boundary layer. We use the data of the Interball-tail probe to study the regions of electron fluxes across the near-Earth magnetotail, up to the distances of 30 R-E. The Interball orbit allows us to scan the tail in both Y-GSM and Z(GSM) coordinates, from low to high latitudes. The spatial distribution of enhanced electron fluxes has been statistically estimated using the data collected during more than 2 years of satellite operation. We have found two basic regions of occurrence: (1) As expected, with a nearly 100% occurrence rate, the electron fluxes have been found in the plasma sheet region, up to 3-4 R-E above the neutral sheet in the central part and up to 7-8 R-E above the neutral sheet near the low-latitude boundary layer; (2) with about 10% occurrence rate, we observe enhanced electron fluxes near the high-latitude magnetopause. In each of these regions, we present a case study based on two point measurements onboard both main satellite and subsatellite. We characterize ion and electron plasma components and motion of observed boundaries. Low-latitude case can be interpreted as irregular flapping of the plasma sheet and its boundary layer. Near the high-latitude magnetopause, the case study shows isolated plasma structures having the size comparable to the Earth's radius and moving with a velocity from several km/s up to several tens of km/s. These structures contain electrons with energies of several hundreds of eV, and their nature remains unclear.