The present study reports the measurements of plasma current sheath (PCS) dynamics, the energy dissipation processes, and the plasma focus (PF) electrical characteristics, particularly during the axial phase discharge in a Mather-type PF device (EAEA-PF1) energized with a 30 µF capacitor bank charged with 8, 10 and 12 kV. All these investigations carried out under discharge conditions where the optimal PF action is achieved. At each charging voltage (V ch), 8 kV, 10 kV and 12 kV, the optimal PF action is studied at different argon gas pressures (P) ranging from 0.4 to 1.2 Torr. The results show that the best PF is formed at V ch = 8 kV and P = 0.6 Torr, V ch = 10 kV and P = 0.8 Torr, and V ch = 12 kV and P = 0.8 Torr. The implosion velocity (V z) results of PCS show that the maximum value of V z (4.48 cm/µs) occurs at the end of the axial phase (i.e., at the coaxial electrode muzzle), which is detected at V ch = 12 kV and P = 0.8 Torr. Moreover, a less inefficient snowplow action is observed under these discharge conditions. The energy dissipation process data indicate that at V ch = 12 kV and P = 0.8 Torr, the ratio between the total energy dissipation and the input energy has a maximum value of 90%, and the minimum residual energy left on the condenser bank (175.39 J) is also achieved under these discharge conditions.

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This paper reports on the selection of insulating material types in a developed atmospheric-pressure non-thermal plasma jet (ANPJ-II) device which was operated previously in our laboratory based on the minimum erosion area of the insulator’s nozzle. Three identical insulator groups used in our experiment include; Teflon insulator material with different thicknesses of 1.5 mm and 2 mm respectively, and Ceramic insulating material with thickness of 2 mm. ANPJ-II device is operated with each of the three insulator groups. These insulators are operated and analyzed with different operation times for compressed Air or Nitrogen gas with a flow rate of 12 L/min and input voltage of 6 kV.  The erosion area of these insulator materials is measured as a function of the operation time. The Ceramic insulator was found to have the minimum erosion area. Also, the temperature of both the cathode and the insulating material (Teflon or Ceramic) are measured to study the effect of operation time and the gas type on the device components.

We report a simple-to-perform technique to investigate the distribution of the azimuthal magnetic field induction, B θ , and the induced magnetic force acting on the plasma current sheath (PCS) in a plasma focus (PF) discharge. This in situ measurement technique can undoubtedly be beneficial when other fast-imaging techniques are not available. techniques are not available. Experimental work was conducted in the low-energy Mather-type EAEA-PF1 device operated in argon. The axial distribution (B θ ) z along the coaxial electrodes system was measured with a four magnetic-probe set technique at different radial distances (r = 2.625 × 10−2 to 4.125 × 10−2 m) within the annular space between the coaxial electrodes during the 1st and 2nd half cycles of the discharge current waveform, where inner electrode of coaxial electrode system has a +ve polarity and −ve polarity, respectively. Axial, radial and total magnetic force distribution profiles were estimated from B θ data. Investigation of PCS shape in terms of its inclination (curvature) angle, θ, along the axial rundown phase and the correlation between the magnetic forces per unit volume acting on the PCS, the inclination angle θ of the PCS, and the formation of a powerful PF action during the 1st and 2nd half cycles is carried out. Dependence of inclination angle, θ, on total magnetic force per unit volume acting on PCS axial motion was studied, separately, during the 1st and 2nd half cycles.

This paper reports on the selection of insulating material types in a developed