Detailed Radiative Opacity Studies of a High-Temperature Gold Plasma

The radiative opacity of a gold plasma at a temperature of 360eV and a density of 0.01g/cm³ has been studied using a detailed level accounting (DLA) method. Under this plasma condition, the average ionization degree is 50.2. Dominant ion types in the plasma are Au⁺⁴⁹, Au⁺⁵⁰ and Au⁺⁵¹, which account for 18.3%, 33.1% and 32.6%, respectively. The spectrally resolved opacity shows complex fine structures. The result obtained by the DLA method is compared with that of the average atom model. Detailed analyses are carried out to study the strongest absorption peaks caused by 3d-4f transitions near the photon energy of 2600eV. To better understand the value of the Rosseland mean opacity, the radiative opacity around the energy region of the maximal Rosseland weighting function is also discussed in detail.