SHEAR-WAVE DISSIPATION IN PLANAR MAGNETIC X-POINTS

The resistive dissipation of nonlinear shear wave disturbances is disc ussed. We consider an incompressible, ''open'' X-point geometry, in wh ich mass and energy are free to enter and leave the reconnection regio n. An analytic treatment is possible which unifies many of the dynamic and steady-state X-point solutions obtained previously. We show that while field disturbances in the plane of the X-point have the potentia l for rapid energy release when suitably driven, perpendicular shear d isturbances dissipate slowly, at a rate similar to eta(1/2), where eta is the plasma resistivity. This behavior can be understood in terms o f the absence of flux pileup in nonplanar shear wave disturbances. We conclude that only planar shear waves have the potential for fast magn etic energy release.