Interrupted z-pinch in argon

The pinch effect in a low-pressure discharge in air between two cone-shaped copper electrodes was investigated. The paraxial dense part of the z-pinch became interrupted due to the barrel shape of the magnetic and electric fields, and two relatively stable plasma jets, connected with the electrode tips, were formed in the discharge shortly after the breakdown. Later a high-density ellipsoidal structure with a sharp boundary formed. Michelson interferometry and the Schlieren method, respectively, were used in measurements of the plasma density in the discharge channel and in the small inhomogeneity regions. A distinct filamentary structure of the plasma jets was well seen in the Schlieren pictures. The electron temperature was calculated from the intensities of spectral lines and of continuum radiation in the visible region. (J.U.) 1 fig., 3 refs