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Title: Continuum Lowering and Fermi-Surface Rising in Strongly Coupled and Degenerate Plasmas

Here, continuum lowering is a well-known and important physics concept that describes the ionization potential depression (IPD) in plasmas caused by thermal-/pressure-induced ionization of outer-shell electrons. The existing IPD models are often used to characterize plasma conditions and to gauge opacity calculations. Recent precision measurements have revealed deficits in our understanding of continuum lowering in dense hot plasmas. However, these investigations have so far been limited to IPD in strongly coupled but nondegenerate plasmas. Here, we report a first-principles study of the K-edge shifting in both strongly coupled and fully degenerate carbon plasmas, with quantum molecular dynamics (QMD) calculations based on the all-electron density-functional theory (DFT). The resulted K-edge shifting versus plasma density, as a probe to the continuum lowering and the Fermi-surface rising, is found to be significantly different from predictions of existing IPD models. In contrast, a simple model of “single atom in box” (SAIB), developed in this work, accurately predicts K-edge locations as what ab-initio calculations provide.
Authors:
 [1]
  1. Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
Publication Date:
Report Number(s):
2017-36, 1349
Journal ID: ISSN 0031-9007; PRLTAO; 2017-36, 2304, 1349; TRN: US1702795
Grant/Contract Number:
NA0001944
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 119; Journal Issue: 6; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
OSTI Identifier:
1375435
Alternate Identifier(s):
OSTI ID: 1374768