In inertial confinement fusion (ICF) experiments, the fusion yield and burn history are key parameters for evaluating implosion performance and analyzing implosion dynamics. During implosion experiments, the 16.75 MeV fusion gamma rays are produced by the T(d, γ)⁵He reaction. Unlike fusion neutrons, fusion gamma rays are not subject to time-of-flight broadening or capsule compression effects, enabling precise measurements of bang time and burn width. In ²H(p, γ)³He experiments, the yield of 5.49 MeV gamma rays is measured to determine the pD reaction S-factor, providing critical constraints for Big Bang nucleosynthesis (BBN) models. Precise characterization of fusion gamma-ray yield and burn history is essential for implosion experiments involving DT and pD reactions.
Fusion gamma-ray diagnostics in implosion experiments face significant interference from prompt neutron-induced gamma rays. Cherenkov detectors are an effective diagnostic for ICF gamma-ray spectra, utilizing their intrinsic threshold effect to reject such background noise. Since background signals in gamma-ray diagnostics depend on target conditions, we analyzed gamma-ray spectra from DT and pD implosions on a 100-kJ laser facility. Then, we propose optimized measurement parameters and forward simulation predictions for the fusion gamma measurement. Using a gas Cherenkov detector, we successfully measured fusion gamma rays from DT and pD reactions on a 100-kJ laser facility. In these implosion experiments, we extracted key parameters such as bang time and burn width, and characterized the gas fluorescence in different media. These results are critical for evaluating DT implosion performance and advancing the study of laser-driven pD reactions.
 

burn width,fusion gamma,Cherenkov,implosion