Session 7E - Space and Basic.
ORAL session, Thursday morning, November 14
Majestic Ballroom, Adam's Mark
In the last meeting in Louisville, the plasma decay of mm scale tiny plasma ball with spheromak type helicity ( 10 microsecond, 100 kA) was discussed with experimental results. This plasma is closely related to the laser produced plasma train to attract and to induce lightning discharge from thunder clouds and the temperature decay time constant is found to be divided into two categories. The fast process is explained reasonably well but the latter, few hundred micro second time scale, is at least one order of magnitude larger than the conventional chemical reaction models. In this paper we show the time history of travelling arcs with a velocity around the sound speed. The arc behaviour as a fluid is reasonably well understood in Newtonian Fluid Model under a reasonable assumptions. However the decay of the temperature in the slower time scale again is somewhat different from the conventional chemical models. Bull.American Phys.Soc., 40,11(1995) OCT, 1775