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Electron-Impact Ionization of Be-like C III, N IV, and O V

Fogle, M.; Bahati, E. M.; Bannister, M. E.; Vane, C. R.; Loch, S. D.; Pindzola, M. S.; Ballance, C, P,; Thomas, R. D.; Zhaunerchyk, V.; Bryans, P.; Mitthumsiri, W.; Savin, Daniel Wolf

We present recent measurements of absolute electron-impact ionization cross sections for Be-like C III, N IV, and O V forming Li-like C IV, N V, and O VI. The measurements were taken using the crossed-beams apparatus at Oak Ridge National Laboratory. A gas cell beam attenuation method was used to independently measure the metastable fractions present in the ion beams. The measured ionization cross sections were compared with calculations using the R-matrix with pseudostates and distorted-wave theoretical methods. Best agreement is found with the R-matrix with pseudostates cross sections results that account for the metastable fractions inferred from the gas attenuation measurements. We present a set of recommended rate coefficients for electron-impact single ionization from the ground state and metastable term of each ion.


Also Published In

The Astrophysical Journal Supplement Series

More About This Work

Academic Units
Astronomy and Astrophysics
Published Here
March 18, 2013