Axial velocity measurement of current sheath in a plasma focus device using a magnetic probe

A magnetic probe was used to study the current sheath in a plasma focus device with energy of about 2.8 kJ. Measurements were carried out for argon gas under a pressure of about 1 mbar. The axial distributions of trajectory, average axial velocity, and magnetic field of the current sheath at a certain radial distance along the axis of the tube were obtained experimentally and theoretically. Experimental results were compared with theoretical calculations which were performed using the snow plow model for the axial phase of the discharge. The voltage and current signals versus time were recorded and the plasma focus was characterized.