Abstract
It is suggested that the high temperature of the corona, 2 x 106K, recognized by the presence of FeXIV is caused by the ionization of accelerated electrons by a double layer. Under the condition of magnetic field-aligned currents (along magnetic loops in the corona) of intensity of about 0.001A (103 µA) and 1 Kev electrons accelerated by the double layer, the ionization rate is estimated to be 6.3x108/cm3s in the middle level of the corona, where the density of hydrogen atoms is about 1011/cm3 at the height of 2 x 103 km. A dynamo process of the photosphere provides the field-aligned currents. A double layer might be formed in a prominent discontinuity of the electron density of about the height of 2 x 103 km, where the above estimates are made.
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