Abstract
The solar corona is believed to be generally low beta. In a low-beta plasma, energy is mainly stored as magnetic energy or current. To dissipate the stored magnetic energy in the highly conductive corona, anomalous resistivity is needed. Activities of outer layers of X-ray loops in solar flares have been interpreted as the result of reconnection of magnetic field due to anomalous resistivity in a current sheet located above the flaring loop. Soft X-ray observations of solar flares show that high density and high temperature plasmas are confined in small volumes. Nobeyama Radioheliograph and TRACE observations suggest that flares originate in small loops. We can expect high beta plasma and small curvature in small loops. They also observed high-velocity flows along magnetic loops associated with flares. Bounded motions of charged particles (both thermal motion and flow) along the magnetic lines of force create the centrifugal force. They exceed gravity force under certain conditions. They can even exceed magnetic tension force depending on plasma beta values of the plasma in the loop. In the case of the upward acceleration (centrifugal - gravity > 0), the plasma is balanced by the magnetic tension force if the beta value is not large enough. This is a favorable condition for the interchange mode instability. Finite beta (beta 0.1) plasma in a loop whose ends are anchored at the photosphere is unstable against the BALLOONING mode. It can develop into non-linear phase and explosive phenomena are expected. This is called HIGH-BETA DISRUPTION. The high-beta disruption has many common characteristics to solar flares. Flare phenomena will be interpreted in terms of high-beta disruption.