Background Flash X-ray radiography is an effective means to obtain the transient density information of an object undergoing high-speed evolution, which is of critical importance in material physics, detonation physics and weapon design. A rod-pinch diode driven by pulsed power is one of the most iconic load configurations in the field of flash X-ray radiography, for its X-ray spot with small size, high dose and fixed position.

Purpose This paper aims to investigate the parallel driven mode of low-impedance wire-shorted rod-pinch diodes as a potential technical approach for synchronous multi-axial and quasi-coaxial multi-frame X-ray radiography, and to characterize the load electrical properties over a wide range of driving currents.

Methods Through experimental trials on a four-stage linear transformer pulsed power driver and circuit simulations in Ansys Simplorer, the X-ray characteristics and electrical performance of the loads are systematically evaluated.

Results Experiments show that the current distribution and the X-ray burst timing can be adjusted by the wire mass. The parallel loads with identical configurations give two X-ray bursts that are synchronous in time and even in dose, which can be used for dual-axial radiography; while the parallel loads with different wire mass give two sequenced X-ray bursts separated by 70 ns, which is suitable for double-frame radiography. Compared with the use of multiple independent pulsed power sources, this technical approach can significantly reduce costs; and compared with the scheme of driving a single load with multiple pulses to achieve multi-frame X-ray output, it features a simpler driving configuration and weaker mutual interference between sequenced pulses. In addition, this paper presents equivalent circuit models for the wire-shorted rod-pinch diode load, the circuit simulation coupling the pulsed power driver and the load gives calculation results consistent with the experimental measurements, further corroborating the conclusions on the plasma dynamics of exploding wire in the load and facilitating the application of the load.

Conclusion In conclusion, the parallel operation mode of low-impedance wire-shorted rod-pinch diodes is demonstrated to be an effective approach for multi-frame or multi-axial flash X-ray radiography, and the circuit model further provides predictive capability for load optimization, supporting its application in advanced radiographic diagnostics.