The effect of a non-Maxwellian electron distribution on oxygen and iron ionization balances in the solar corona

Abstract

view Abstract Citations (130) References (44) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The effect of a non-Maxwellian electron distribution on oxygen and iron ionization balances in the solar corona Owocki, S. P. ; Scudder, J. D. Abstract Analytic expressions are derived for ionization and recombination rates in a parameterized non-Maxwellian electron velocity distribution with an enhanced high-energy tail. These expressions are then used in investigating the effect of such an enhancement in the high-energy tail of the coronal electron velocity distribution on the oxygen and iron ionization balances, O(+6) - O(+7) and Fe(+11) - Fe(+12). Relative to a Maxwellian of the same mean electron energy, the degree of ionization allowed by such a distribution is found to be either unchanged or slightly decreased for iron but often substantially increased for oxygen. The greater sensitivity of oxygen ionization balance to the high-energy distribution tail derives from the higher oxygen ionization threshold energy. It is noted that the electron temperature inferred from a measurement of the oxygen ionization ratio, O(+6)/O(+7), could indeed overestimate the actual coronal electron temperature by nearly 10 to the 6th K if the coronal electron distribution is incorrectly assumed to be Maxwellian. Publication: The Astrophysical Journal Pub Date: July 1983 DOI: 10.1086/161167 Bibcode: 1983ApJ...270..758O Keywords: Electron Distribution; Ionization; Solar Corona; Electron Energy; Iron; Oxygen Ions; Radiative Recombination; Velocity Distribution; Solar Physics full text sources ADS |