Nagayama T, Bailey J E, Loisel G P, Dunham G S, Rochau G A, Blancard C, Colgan J, Cossé Ph, Faussurier G, Fontes C J, Gilleron F, Hansen S B, Iglesias C A, Golovkin I E, Kilcrease D P, MacFarlane J J, Mancini R C, More R M, Orban C, Pain J-C, Sherrill M E, Wilson B G
Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
CEA, DAM, DIF, F-91297 Arpajon, France.
Phys Rev Lett. 2019 Jun 14;122(23):235001. doi: 10.1103/PhysRevLett.122.235001.
The first systematic study of opacity dependence on atomic number at stellar interior temperatures is used to evaluate discrepancies between measured and modeled iron opacity [J. E. Bailey et al., Nature (London) 517, 56 (2015)NATUAS0028-083610.1038/nature14048]. High-temperature (>180 eV) chromium and nickel opacities are measured with ±6%-10% uncertainty, using the same methods employed in the previous iron experiments. The 10%-20% experiment reproducibility demonstrates experiment reliability. The overall model-data disagreements are smaller than for iron. However, the systematic study reveals shortcomings in models for density effects, excited states, and open L-shell configurations. The 30%-45% underestimate in the modeled quasicontinuum opacity at short wavelengths was observed only from iron and only at temperature above 180 eV. Thus, either opacity theories are missing physics that has nonmonotonic dependence on the number of bound electrons or there is an experimental flaw unique to the iron measurement at temperatures above 180 eV.
首次在恒星内部温度条件下对不透明度与原子序数的依赖关系进行的系统研究，被用于评估实测铁不透明度与模型预测之间的差异[J. E. 贝利等人，《自然》（伦敦）517, 56 (2015)NATUAS0028 - 083610.1038/nature14048]。采用与之前铁实验相同的方法，测量了高温（>180 eV）下铬和镍的不透明度，测量不确定度为±6% - 10%。10% - 20%的实验可重复性证明了实验的可靠性。整体模型与数据的差异比铁的情况要小。然而，该系统研究揭示了密度效应、激发态和开放L壳层构型模型中的缺陷。仅在铁中且仅在温度高于180 eV时，观察到短波长处模型预测的准连续不透明度被低估了30% - 45%。因此，要么不透明度理论遗漏了对束缚电子数具有非单调依赖关系的物理机制，要么在温度高于180 eV时铁的测量存在独特的实验缺陷。
