Abstract

The possibility of ionization of the solar coronal loops by energetic current-carrying electrons is investigated, since FeXII and other highly ionized atoms are brightest along looped magnetic field lines in the corona. In this paper, we consider a photo spheric dynamo under a magnetic arcade as the source of field-aligned current. Assuming the current intensity of 1 A/cm2, the density N = 1012/cm3 in the lower corona (not too different from the auroral condition) and current-carrying electrons accelerated by the double layer 10 KeV, the ionization rate q is estimated to be 1.3 x 104/cm3s. The result is compared with the auroral ionization, which is caused basically by the same process and is well confirmed (1.3 x 105/cm3s) by observations. A possible consequence of our consideration on the coronal temperature is mentioned.