Deuterium hybrid X-pinch driven by small dense plasma focus

This study presents a proof of the concept of a deuterium hybrid X-pinch configuration, driven by a 3 kJ dense plasma focus (PFZ-200) at the Czech Technical University in Prague. The system consists of two opposing conical electrodes filled with deuterium gas, forming a point-like source of DD fusion protons via D(d,p)T reactions. Two axial anode–cathode gaps of 3 and 5 mm were investigated. Key diagnostics included CR-39-based proton imaging, pinhole camera, and energy spectrometry. The smaller A–K gap (3 mm) produced a compact, nearly circular proton source with a diameter of 1.2 mm and yields on the order of 107 protons/shot. Based on the spectral measurements, the maximum proton energy reached 3.6 MeV, corresponding to deuteron energies approximately up to 1.3 MeV. Compared to standard plasma focus operation, the hybrid X-pinch configuration provided improved proton source localization suitable for advanced plasma diagnostics such as proton imaging and deflectometry.