Operation stability, pinching efficiency and speed factor in 3-joules miniature plasma pinch generator, for different electrodes geometry

Regarding the importance of the stability in a miniature pinch plasma generator in repetitive and strong plasma pinch, the stable operation of a 3J miniature plasma focus device in two single-shot and repetitive discharge modes (at 0.5Hz and 5Hz discharge frequencies) and the factors in creation of switch misfire was demonstrated. Then, the device efficiency and strength of the plasma pinch for four different coaxial electrode configurations were studied, upon scanning argon gas pressure ranged from 0.6 to 1.5 mbar via the study of the charging voltage variation from 8.3 to 9.3 kV. It was observed that the strength and efficient pinching is appropriately produced for the tapered anode configuration over an expanded operating pressure ranged from 0.6 to 1.5 mbar. After the calculation of the speed factor and pinch sensitivity for the optimum electrodes geometry, it was shown that the best plasma compression at the pinch phase was associated with 0.88±0.8 mbar argon gas pressure and 8.3-8.5 kV charging voltage, respectively. From the viewpoint of the stability assessment of the device, it was observed that the stable operation of the device was for the charging voltage of 8.3 to 8.7 kV in the operating pressure of 0.6 to 1.1 mbar.