Application of a high-speed imaging system for characterization of a hypersonic plasma jet

Plasma-jet-driven magneto-inertial fusion (PJMIF), achieving uniform high-Z plasma liners via hypersonic plasma jets (Ma > 10), requires precise control of jet reproducibility, synchronization, and mass/velocity uniformity. To address jet nonuniformities in the coaxial plasma gun of the ShanghaiTech Gun1 (STG1) facility, a high-speed imaging system utilizing intensified complementary metal oxide semiconductor (ICMOS) cameras (5120×5120 pixels, 3 ns exposure) with synchronized triggering (< 1 μs delay, < 50 ps jitter) was developed. The system’s 45°×45° field of view (42×42 cm² midplane coverage) and ~ 1 mm spatial resolution enabled non-perturbative monitoring of hypersonic argon plasma jets (v_jet ~ 100 km/s). Triaxial imaging (top/side/end-on views) quantified axial deviations and jet structures, while densitometric profiling derived Mach numbers through boundary spread angles. This diagnostic approach resolves critical challenges in PJMIF gun optimization, with future extensions to multi-channel imaging, narrowband spectral filtering, and 3D reconstruction.