Effect of the Gas Pressure, Charging Voltage, and Anode Length on the Neon Soft X-Ray Emission From Plasma Foci—Measurements and Simulation

Abstract

Using the Lee model code, numerical experiments were performed to compute the soft x-ray (SXR) yield as a function of the initial neon pressure for seven different energy plasma focus devices (NX2, INTI, UNU/ICTP, APF, NX1, PF7, PF24). In addition, the effect of operation voltage for four plasma focus devices (APF, NX2, UNU/ICTP, NX1) and the anode length for two plasma focus devices (NX1, NX2) on the soft x-ray yield (Y_sxr) versus pressure was studied and discussed. At experimental pressure, the computed current waveform was well fitted to the measured total current waveform for each device. Furthermore, the maximum discharge current, pinch current, axial and radial velocities, average pinch temperatures and densities, and pinch dimensions around the optimum pressure for the maximum Y_sxr were computed for the seven mentioned devices. The computed values obtained are within the temperature window required to generate H-like (1022 eV) and He-like (922 eV) plasmas. The computed Y_sxr are in good agreement with part of the experimental results. Moreover, experimental and computed values of the end axial speed (v_a), final inward shock speed (v_s), the speed factor (SF) and the current per cm of anode radius (ID) were compared for part of the considered devices.