STRUCTURE AND DYNAMICS OF CURRENT SHEETS AT ALFVEN RESONANCES IN A DIFFERENTIALLY ROTATING PLASMA

Alfven resonances, where the local flow speed relative to the boundary is equal to the local Alfven speed, introduce novel dynamical feature s in a differentially rotating plasma. The spatial structure and dynam ics of current sheets in such plasmas is investigated analytically as well as numerically. The current sheets at Alfven resonances tend to p ower-law singularities. The growth of current sheets is algebraic in t ime in the linear regime and saturates in the presence of dissipation without the intervention of nonlinear effects. These results have sign ificant implications for forced reconnection and Alfven wave dissipati on in laboratory and space plasmas. (C) 1998 American Institute of Phy sics. [S1070-664X(98)00606-5]