Electron impact double ionization of singly charged ions C + , N + , O + , F + and Ne +

The first absolute cross section measurements for double ionization of C+, N+, O+ and Ne+ ions by electron impact are reported. The animated crossed beams method has been employed in the energy range from below ionization thresholds to approximately 2500 eV. The classical binary encounter approximation overestimates measured cross sections by almost two orders of magnitude. Along the sequence, the cross section maximum does not follow classical scaling laws. A simple scaling law based on an electron pair ejection model is proposed for the prediction of direct double ionization. Inner-shell ionization followed by autoionization is seen to play a dominant role for C+ only.

[1]  D. Yu,et al.  The formation of H+ from H- by electron impact , 1992 .

[2]  Z. Hui,et al.  Absolute Cross-section Measurements for Electron-impact Ionization of Ar-7+ , 1991 .

[3]  S. Chantrenne,et al.  Absolute Cross-section Measurements for Electron-impact Ionization of Li-like N-4+, O+5+, and Ne-7+ Ions , 1990 .

[4]  Mantian Liu,et al.  Cross sections for K-shell ionization by electron impact☆ , 1990 .

[5]  A. Müller,et al.  Electron impact double ionisation of Arq+ ions (q=1, 2, …, 7): two-electron processes compared with inner-shell contributions , 1989 .

[6]  H. Koslowski,et al.  Partial and state-selective cross sections for multiple ionisation of rare-gas atoms by electron impact , 1989 .

[7]  Hofmann,et al.  Resonances in electron-impact single, double, and triple ionization of heavy metal ions. , 1988, Physical review letters.

[8]  Y. Ikezaki,et al.  Measurements of Cross Sections for Single and Double Ionization of Na+ and K+ by Electron Impact , 1986 .

[9]  T. Oguri,et al.  Angular Distribution of Scattered Electron and Medium Energy Electron Spectroscopy for Metals , 1986 .

[10]  P. Grujić.  The threshold law for double ionisation in electron-atom collisions , 1983 .

[11]  D. W. Hughes,et al.  Absolute experimental cross sections for the electron impact single, double, triple, and quadruple ionization of Cs+ ions , 1982 .

[12]  W. Claeys,et al.  Crossed beam measurement of absolute cross sections: an alternative method and its application to the electron impact ionisation of He+ , 1981 .

[13]  A. Mueller,et al.  L-shell contributions to multiple ionization of Ar/sup i/+ ions (i=1,2,3,) by electron impact , 1980 .

[14]  R. Tweed.  Double ionization by electron impact: I. General theory , 1973 .

[15]  R. Tweed.  Double ionization by electron impact: II. Calculations of cross sections for H-, He and Li+ , 1973 .

[16]  B. Peart,et al.  Electron detachment from H- ions by electron impact , 1970 .

[17]  B. Peart,et al.  The ionization of Li+ to Li3+ by electron impact , 1969 .

[18]  W. Lotz,et al.  Electron-impact ionization cross-sections and ionization rate coefficients for atoms and ions from hydrogen to calcium , 1968 .

[19]  C. Joachain,et al.  Multiple ionization processes in helium , 1967 .

[20]  C. Joachain,et al.  Importance of Correlation Effects in the Ionization of Helium by Electron Impact , 1966 .

[21]  M. Gryziński,et al.  Classical Theory of Atomic Collisions. I. Theory of Inelastic Collisions , 1965 .

[22]  G. Wannier.  Threshold Law for Multiple Ionization , 1955 .