Accurate plasma diagnostics using collective Thomson scattering (TS) are essential in Inertial Confinement Fusion (ICF) research. However, measuring TS spectra in an ICF hohlraum presents significant challenges due to weak signals and intense background noise. One practical approach to mitigate these challenges is to optimize the scattering angle. In forward scattering calculations, the conventional collisionless model can greatly distort TS spectra under low temperature and high density conditions. To address this issue, we considered a collision correction based on the BGK model. Analysis indicates that there is an optimal scattering angle for the TS electron spectra. At this angle, the intensity of the resonance peak is maximized, and the peak width is narrowed, making it easier to identify against a broad background. According to theoretical evaluations, we conducted TS measurements on the Shenguang-100 kJ laser facility using 42° scattering, which can increase the signal intensity by ~4 times compared to traditional 90° scattering. The measurements are conducted in the coronal region of a gas-filled hohlraum, successfully obtaining both TS electron and ion spectra. This research provides valuable insights into the evolution of electron density and temperature at the interface of the "gold bubble", establishing a foundation for future studies in hohlraum plasma physics.

Thomson scattering,collision,hohlraum plasma