Electron-impact excitation of the 3s''3P° and 2s2p53P° autoionizing states of atomic oxygen

✍ Scribed by E.C. Zipf; W.W. Kao

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 542 KB
• Volume: 125
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(86)85179-x

✦ Synopsis

The excitation of the ~s"~P' and 2s2ps3Po autoionizing states of 01 by electron impact on atomic oxygen has been studied. Absolute cross section values from threshold to 300 eV have been obtained for the ~s"~P' state. Limited emission cross section data for the 2s2p5 3P0 and other partially radiating autoionizing states were also obtained at an impact energy of 100 eV. These results suggest that the excitation of the 01 autoionizing states account for = 33% of the total O+ total ionization cross section at 40 eV under optically thin conditions and that the cross section ratio, e( 4S)/o( 2 D + 'P), has been underestimated substantially in earlier theoretical work. Electron-impact excitation of the ~s"~P" and 2s2p5"Po states in an optically thick medium enhances the effective total ionization cross section for atomic oxygen by = 15% and increases the specific O+ (4S) production rate by = 25% with important implications for Of ion chemistry in gaseous discharges and planetary ionospheres.