New computational method for non-LTE, the linear response matrix

摘要

My coauthors have done extensive theoretical and computational calculations that211u001elay the ground work for a linear response matrix method to calculate non-LTE 211u001e(local thermodynamic equilibrium) opacities. I will give briefly review some of 211u001etheir work and list references. Then I will describe what has been done to 211u001eutilize this theory to create a computational package to rapidly calculate mild 211u001enon-LTE emission and absorption opacities suitable for use in hydrodynamic 211u001ecalculations. The opacities are obtained by performing table look-ups on data 211u001ethat has been generated with a non-LTE package. This scheme is currently under 211u001edevelopment. We can see that it offers a significant computational speed 211u001eadvantage. It is suitable for mild non-LTE, quasi-steady conditions. And it 211u001eoffers a new insertion path for high-quality non-LTE data. Currently, the linear 211u001eresponse matrix data file is created using XSN. These data files could be 211u001egenerated by more detailed and rigorous calculations without changing any part of 211u001ethe implementation in the hydro code. The scheme is running in Lasnex and is 211u001ebeing tested and developed.