The Effects of Ferrites on Dense Plasma Focus Device: Using a Modification to the Lee Model

摘要

The Lee mode code has been promoted for better simulation of the dense plasma focus (DPF) device. At the first step, the calculation of magnetic field and tube inductance was improved to include the geometry of the rods forming the cathode. At the second step, the influences of the number of the cylindrical cathodes have been investigated. Ultimately, for enhancing the current sheath dynamics in the axial acceleration phase, the effects of ferrites located near the cathodes have been studied. Simulations were performed with integrating the modified generating equations. The influences of the ferrite's susceptibility as well as saturation field on the current waveform, the tube inductance, and the current sheath speed in the DPF axial phase have been investigated. The numerical studies showed that increasing the number of cathodes would decrease the starting time of the pinch phase. The weak ferrites presented some enhancement in the total magnetic field and the axial speed of the current sheath.