Discover sub-ns dynamics in pulsed discharges with synchronised high-speed optical and electrical diagnostics

Low-temperature plasmas have a wide range of applications, from modifying the surface of materials to providing advanced biomedical treatments. In many discharges operating at atmospheric pressure, the underlying processes unfold within sub-nanosecond timescales. During these rapid breakdown events, important reactive species are formed that trigger multiple plasma-chemical reactions. Therefore, to understand the spatial and temporal evolution of the discharge, diagnostics are required that can capture phenomena on sub-nanosecond scales.

This contribution emphasises the significant advantages of combining sub-nanosecond optical diagnostics with high-speed electrical measurements. Modern emission-based techniques, such as streak cameras with picosecond resolution, demonstrate this capability. This article details the operating principles of a streak camera system, including how it synchronises with pulsed plasma generation to capture transient emission profiles. This approach provides detailed insights into the early breakdown stages of the discharge with sub-nanosecond resolution.

It is shown how ultrafast optical and electrical diagnostics reveal critical discharge parameters, providing deeper insights into fundamental plasma behaviour at atmospheric pressure. Several case studies underscore the versatility of this technique, demonstrating how breakdown can be tracked with exceptional temporal precision.

Overall, this work demonstrates that, when combined with synchronised electrical measurements, sub-nanosecond diagnostics enable researchers to investigate—and ultimately control—key aspects of plasma formation and evolution. These methods not only elucidate fundamental physical mechanisms, but also provide valuable benchmarks for validating simulations and driving innovation in various areas of plasma technology.