Gold charge state distributions in highly ionized, low-density beam plasmas

Journal Article · Sat Oct 15 00:00:00 EDT 2011 · Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)

DOI:https://doi.org/10.1103/PHYSREVE.84.046402· OSTI ID:21612131

May, M J; Scofield, J; Schneider, M; Wong, K; Beiersdorfer, P ^[1]; Hansen, S B ^[2]

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1. PO Box 808 L260, Lawrence Livermore National Laboratory, Livermore California 94551 (United States)
2. Sandia National Laboratories, ICF Target Design, Albuquerque New Mexico, 87185-1186 (United States)

We present a systematic study of Au charge state distributions (CSDs) from low density, nonlocal thermodynamic equilibrium plasmas created in the Livermore electron beam ion traps (EBIT-I and EBIT-II). X-ray emission from Ni-like to Kr-like Au ions has been recorded from monoenergetic electron beam plasmas having E{sub beam}=2.66, 2.92, 3.53, and 4.54 keV, and the CSDs of the beam plasmas have been inferred by fitting the collisionally excited line transitions and radiative recombination emission features with synthetic spectra. We have modeled the beam plasmas using a collisional-radiative code with various treatments of the atomic structure for the complex M- and N-shell ions and find that only models with extensive doubly excited states can properly account for the dielectronic recombination (DR) channels that control the CSDs. This finding would be unremarkable for plasmas with thermal electron distributions, where many such states are sampled, and the importance of DR is well established. But in an EBIT source, the beam is resonant with only a subset of such states having spectator electrons in orbitals with high principal quantum number n (8{<=}n{<=}20). The inclusion of such states in the model was also necessary to obtain agreement with observed stabilizing transitions in the x-ray spectra.

• OSTI ID: 21612131
• Journal Information: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print), Vol. 84, Issue 4; Other Information: DOI: 10.1103/PhysRevE.84.046402; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1539-3755
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHARGE STATES
ELECTRON BEAMS
EQUILIBRIUM PLASMA
EXCITED STATES
GOLD
GOLD IONS
M SHELL
N SHELL
RECOMBINATION
X-RAY SPECTRA
BEAMS
CHARGED PARTICLES
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY LEVELS
IONS
LEPTON BEAMS
METALS
PARTICLE BEAMS
PLASMA
SPECTRA
TRANSITION ELEMENTS