Assessing the impact of pre-ionization technique on the homogeneity and stability of the current sheath layer in dense plasma focus device

In this research, the pre-ionization technique was applied using an optimal shunt resistor on a Dense Plasma Focus (DPF) device filled with deuterium as the working gas. The effects of this technique on the properties of the current sheath layer, particularly its homogeneity and stability, which are crucial factors in the quality of nuclear fusion, have been investigated. Time-frequency wavelet analysis of pulses obtained from Mirnov coils in two different configurations (toroidal and poloidal arrangements) indicated the effect of this technique on improving the homogeneity of the magnetic field intensity produced by the current sheath layer. Time-Integrated Analysis (TIA) and Frequency-Integrated Analysis (FIA) of the Mirnov circuit pulses, along with the evaluation of the magnetic field intensity ratios of these coils placed at specific azimuthal angles (particularly 0 and 180 degrees) and different orientations (particularly radial and axial), demonstrated the positive effect of the current sheath's homogeneity on the quantitative convergence of these ratios. This convergence indicates the beneficial effect of the pre-ionization technique in reducing the stresses, asymmetries, and instabilities of the current sheath layer, which subsequently leads to an improvement in the efficiency of the nuclear fusion reaction in the DPF system.