Electron-impact Multiple-ionization Cross Sections for Atoms and Ions of Helium through Zinc
Abstract
We compiled a set of electron-impact multiple-ionization (EIMI) cross section for astrophysically relevant ions. EIMIs can have a significant effect on the ionization balance of non-equilibrium plasmas. For example, it can be important if there is a rapid change in the electron temperature or if there is a non-thermal electron energy distribution, such as a kappa distribution. Cross section for EIMI are needed in order to account for these processes in plasma modeling and for spectroscopic interpretation. Here, we describe our comparison of proposed semiempirical formulae to available experimental EIMI cross-section data. Based on this comparison, we interpolated and extrapolated fitting parameters to systems that have not yet been measured. A tabulation of the fit parameters is provided for 3466 EIMI cross sections and the associated Maxwellian plasma rate coefficients. We also highlight some outstanding issues that remain to be resolved.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2017
- DOI:
- 10.3847/1538-4357/aa9276
- arXiv:
- arXiv:1708.02155
- Bibcode:
- 2017ApJ...850..122H
- Keywords:
-
- atomic data;
- atomic processes;
- techniques: spectroscopic;
- Astrophysics - Instrumentation and Methods for Astrophysics;
- Physics - Atomic Physics
- E-Print:
- Submitted to Astrophysical Journal Supplement. The cross section database (Table 2 in the manuscript) is available upon request