Improved electron collisional line broadening for low-temperature ions and neutrals in plasma modeling

Journal Article · Tue Sep 29 00:00:00 EDT 2015 · Journal of Physics. B, Atomic, Molecular and Optical Physics

DOI:https://doi.org/10.1088/0953-4075/48/22/224009· OSTI ID:1233549

Johns, H. M. ^[1]; Kilcrease, D. P. ^[1]; Colgan, J. ^[1]; Judge, E. J. ^[1]; Barefield II, J. E. ^[1]; Wiens, R. C. ^[1]; Clegg, S. M. ^[1]

---

1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

In this study, electron collisional broadening of observed spectral lines depends on plasma electron temperature and density. Including this effect in models of measured spectra is necessary to determine plasma conditions; however, computational limits make accurate line broadening treatments difficult to implement in large-scale plasma modeling efforts. In this paper, we report on improvements to the treatment of electron collisional line broadening and illustrate this with calculations using the Los Alamos ATOMIC code. We implement the Dimitrijevic and Konjevic modified semi-empirical model Dimitrijevic and Konjevic (1986 Astron. and Astrophy. 163 297 and 1987 Astron. Astrophys. 172 345), which we amend by employing oscillator strengths from Hartree–Fock calculations. This line broadening model applies to near-neutral plasmas with electron temperatures of Te ~ 1 eV and electron densities of N_e ~10¹⁷ cm^-3. We evaluate the D.K.-inspired model against the previous hydrogenic approach in ATOMIC through comparison to NIST-rated measurements for selected neutral and singly-ionized Ca, O, Fe, and Sn lines using both fine-structure and configuration-averaged oscillator strengths. The new D.K.-inspired model is significantly more accurate than the previous hydrogenic model and we find the use of configuration-averaged oscillator strengths a good approximation for applications such as LIBS (laser induced breakdown spectroscopy), for which we demonstrate the use of the D.K.-inspired model.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1233549
• Alternate ID(s): OSTI ID: 1342267
• Report Number(s): LA-UR-15-23919; TRN: US1600379
• Journal Information: Journal of Physics. B, Atomic, Molecular and Optical Physics, Vol. 48, Issue 22; ISSN 0953-4075
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
LIBS
stark broadening
ATOMIC
CATS
NIST Atomic Spectral Database
line broadening