Cross section  for electron imipact ionization of O2
O2  + e => O2+ + 2e

ref: Itikawa 2009
"Cross sections for electron collisions with Oxygen molecules", J.Phys.Chem.Ref.DATA,vol.38, No.1,2009
Table 11:  not listed here:  table 11 list also XS for O2 + e => O+
                                          O2 + e => O++


energy(eV)  Cross section (1e-16 cm2)

12. 0.
13. 0.0127
15.5 0.0792 
18. .178
23. .4
28. .69
33. .83
38. 1.
43. 1.5
48. 1.7
53. 1.9
58. 2.0
63. 2.2
68. 2.3
73. 2.4
78. 2.4
83. 2.4
88. 2.5
93. 2.5
98. 2.5
108. 2.5
118. 2.6
138. 2.6
158. 2.6
178. 2.4
198. 2.4
223. 2.3
248. 2.2
273. 2.1
298. 2.0
348. 1.9
398. 1.7
448. 1.6
498. 1.0
548. .95
598. 0.9
648. .86
698. .82
748. .78
798. .74
848. .71
898. .69
948. .66
998. .64