Electrostatic ion-cyclotron heating of solar atmosphere

Some consequences of current dissipation in the coronal magnetic loops are studied. Particular attention is paid to the electrostatic ion-cyclotron (ESIC) instability, which possesses a self-limiting heating mechanism and which can be excited with a lower electron drift velocity than the Buneman instability. A current-carrying loop will have nonsymmetric temperature and density distributions across the top of the loop. When the electron drift velocity is near or above the critical value for the ESIC instability, the plasma will be heated to a temperature of up to a few million kelvins if the electron density is approximately 100 million per cubic cm and the height of the loop is approximately 1 billion cm. Furthermore, the ion temperature will be as much as a factor of 2 higher than the electron temperature if the ESIC instability criterion is satisfied. Otherwise, the ion and the electron temperatures will be the same.