Messung der radialen Elektronendichte- und Magnetfeldverteilung beim Thetapinch und Vergleich mit numerischen Rechnungen

Abstract

In a θ-pinch the electron density as function of space and time has been measured bya MACH-ZEHNDER interferometer. Also the magnetic fields have been determined with help of magnetic probes. These experimental results are compared with the hydromagnetic theory. The agreement between these two holds for several compressions in the case of a captured parallel field, however, only for one compression for the antiparallel field. The disagreement for later times for the parallel field case can be explained by end losses and incomplete ionization which is not taken into account in the theory. In the antiparallel field case, however, the disagreement cannot be explained by generalizing the hydromagnetic theory. It seems almost sure that microinstabilities will cause the fast mixing of magnetic fields found experimentally.