Electron-impact ionization of Be-like CIII, NIV, and OV

被引:32
作者
Fogle, M. [1 ]
Bahati, E. M. [1 ]
Bannister, M. E. [1 ]
Vane, C. R. [1 ]
Loch, S. D. [2 ]
Pindzola, M. S. [2 ]
Ballance, C. P. [3 ]
Thomas, R. D. [4 ]
Zhaunerchyk, V. [4 ]
Bryans, P. [5 ]
Mitthumsiri, W. [5 ]
Savin, D. W. [5 ]
机构
[1] Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA
[2] Auburn Univ, Dept Phys, Auburn, AL 36849 USA
[3] Rollins Coll, Dept Phys, Winter Pk, FL 32789 USA
[4] Univ Stockholm, Dept Phys, S-10691 Stockholm, Sweden
[5] Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA
关键词
atomic data; atomic processes; methods : laboratory;
D O I
10.1086/525256
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
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.
引用
收藏
页码:543 / 556
页数:14
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