The 9th International Conference on Matter and Radiation at Extremes (ICMRE2026) ( ICMRE2026)

The China Z-Pinch Fusion Facility (CZFF) employs the Z-pinch inertial confinement fusion approach, utilizing intense pulsed currents to drive the implosion of cylindrical Z-pinch plasma. This process forms a high-temperature hohlraum radiation field that compresses a deuterium-tritium (DT) capsule to achieve fusion. Neutron yield serves as a critical parameter for quantifying capsule implosion performance and determining the success of thermonuclear ignition. The CZFF facility implements three activation schemes—indium, copper, and zirconium activation—for direct diagnosis of neutron yield and its spatial distribution. The study theoretically analyzes factors influencing two key metrics: neutron yield measurement range and measurement uncertainty. Through empirical extrapolation, it examines how parameters such as sample size, activation distance, and measurement time affect the yield measurement range. Using Geant4 Monte Carlo simulations, it assesses the impact of scattered neutrons, background counts, and interfering reactions on yield measurement uncertainty, proposing methods to enhance diagnostic accuracy in future construction phases. Considering the structural features of the CZFF vacuum target chamber, the paper details the spatial layout of the zirconium activation subsystem in the target area and evaluates the effect of scattered neutrons on areal density asymmetry diagnosis via Monte Carlo simulations. This research provides a reference for optimizing neutron activation schemes in inertial confinement fusion (ICF).

Neutron activation diagnostic,Z-pinch,Geant4 simulation,Neutron yield