We have studied experimentally the relation between the preionization of a plasma micro-channel in Argon at atmospheric pressure and the dynamics of the discharge initiated by preionization. Preionization is obtained in two different ways: (a) injecting the soft X rays produced by a 3 J, 3 ns YAG laser focused on a copper target through a pinhole (b) direct focusing of a 4ω laser (0·26 μm) along the Argon column. Both experiments and simple numerical models are presented in this paper.
Digital holographic interferometry employing Fresnel transform reconstruction for the study of flow shear stabilized Z-pinch plasmas