First-principles estimation of plasma jet properties from x-ray Thomson scattering spectrum in the double-cone ignition scheme

In the Double-Cone Ignition (DCI) scheme, the unique configuration of the gold cones facilitates plasma compression. However, the gold impurity in the plasma jet may have a potential impact on the energy conversion efficiency and final fusion yield. In this study, we reanalyzed the X-ray Thomson scattering spectrum from DCI-R7 experiments by combining the imaginary-time correlation function method with first-principles calculations. Our findings revise the previously diagnosed temperature of 50 ± 10 eV to 25 eV, with a density of 8 ± 2 g/cm³ and only 0.162 ± 0.015 % of gold impurity. These results provide clear evidence of the role played by the gold cones during the compression process, and demonstrate that the gold impurity fraction is well within acceptable limits.