Optimization of double-wire X-pinch using prepulse current

Abstract

The radiation properties including size, intensity, and pulse width of the double-wire X-pinch were optimized using prepulse current. The optimization mechanism was investigated using optical diagnostics. The X-pinch driven by a current with a peak intensity of ∼250 kA and a rise rate of 0.95 kA/ns was difficult to produce strong radiation. The application of prepulse effectively enhances the current rise rate and intensity of the radiation source. The radiation source also exhibited reduced spatial dimensions and radiation duration, thereby improving spatial and temporal resolution while used in x-ray projection shadow radiography. The magnetic field and current distribution were measured using Faraday rotation. During the early stage, the current predominantly flows in the corona plasma at a larger radius generated by the prepulse current, consequently reducing the load inductance. As the time delay between the main and prepulse current increased, the intensity of the radiation source further increased. This study provides an approach for controlling radiation sources and enables different applications of X-pinches with adjustable prepulse current.