An improved view-factor method including plasma filling for angular distribution of radiation temperature from a laser-driven hohlraum

Angular distribution of radiation temperature from a laser-driven hohlraum is vital for investigations on the radiation field inside the hohlraum, code validation, and predication of drive on the capsule in indirect-drive inertial confinement fusion. A modified version of the view-factor method including plasma filling is proposed, which improves the accuracy of the description of angular distribution of radiation temperature. Firstly, the radial velocity of the gold bubble motion is scaled from a simple data-based model in a gas-filled hohlraum experiment performed on a hundreds of kJ laser facility in China. Then, an equivalent radiative volume model is advanced to approximately characterize the contribution of the blow-off bubble in the new view-factor method incorporate into IRAD3D. The simulation shows reasonable agreement with experimental measurements in a gas-filled hollow hohlraum. Furthermore, the influence of the electron density and temperature distribution, and bubble velocity, is analyzed. The value of the method is that it can be used as an approximate 'first-look' at hohlraum energy balance prior to a more detailed radiation hydrodynamic modeling.