Atomic structure considerations for the low-temperature opacity of Sn

Journal Article · Fri Mar 31 00:00:00 EDT 2017 · High Energy Density Physics

DOI:https://doi.org/10.1016/j.hedp.2017.03.009· OSTI ID:1352383

Colgan, J. ^[1]; Kilcrease, D. P. ^[1]; Abdallah, J. ^[1]; Sherrill, M. E. ^[1]; Fontes, C. J. ^[1]; Hakel, P. ^[1]; Armstrong, G. S. J. ^[2]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kansas State Univ., Manhattan, KS (United States). J.R. Macdonald Lab.

Here, we have begun a preliminary investigation into the opacity of Sn at low temperatures (< 50 eV). The emissivity and opacity of Sn is a crucial factor in determining the utility of Sn in EUV lithography, with numerous industrial implications. To this end, we have been exploring the accuracy of some approximations used in opacity models for the relevant ion stages of Sn (neutral through ~ 18 times ionized). We also find that the use of intermediate-coupling, as compared to full configuration-interaction, is not adequate to obtain accurate line positions of the important bound-bound transitions in Sn. One requires full configuration-interaction to properly describe the strong mixing between the various n=4 sub-shells that give rise to the Δn= 0 transitions that dominate the opacity spectrum at low temperatures. Furthermore, since calculations that include full configuration-interaction for large numbers of configurations quickly become computationally prohibitive, we have explored hybrid calculations, in which full configuration-interaction is retained for the most important transitions, while intermediate-coupling is employed for all other transitions. After extensive exploration of the atomic structure properties, local-thermodynamic-equilibrium (LTE) opacities are generated using the ATOMIC code at selected temperatures and densities and compared to experiment.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1352383
• Alternate ID(s): OSTI ID: 1419534
• Report Number(s): LA-UR-17-21866; TRN: US1700562
• Journal Information: High Energy Density Physics, Vol. 23, Issue C; ISSN 1574-1818
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
opacity