Asymptotic SelfSimilar Solutions of ZPinches in Vacuum
Abstract
The dynamics of axially symmetric magnetized Zpinches is studied. Radiation is neglected, while ohmicheating and thermalconductivity of the plasma are taken into account. The selfsimilar problem is treated analytically by asymptotic expansions in the limit of high but finite thermal conductivity. An asymptotic solution is obtained with the aid of the principle of minimum singularity. Explicit expressions for radial profiles characterizing Zpinches carrying power law in time total currents (I=I_0t^S ) are found that depend on the line density, the total current amplitude I_0, and exponent S. A nonequilibrium solution is obtained for S=1/5 in addition to the conventional selfsimilar solutions for either exact (for S=± 1/3, Coppins M., Culverwell I.D. and Haines M.G., Phys. Fluids, 31(9), 2688, 1988) or longtime asymptotic equilibrium of Zpinches (Bud'ko A.B., Kravchenko Yu., Uby L., Plasma Phys. Control. Fusion, 36, 833, 1994) . It is shown that the latter is possible only for S>1/5. The multiplicity of the selfsimilar solutions is analyzed.
 Publication:

APS Division of Plasma Physics Meeting Abstracts
 Pub Date:
 October 2003
 Bibcode:
 2003APS..DPPLP1144S