Abstract
A measurement of the doubly differential cross sections of secondary electrons ejected from molecular oxygen by electron impact has been made. A modulated crossed-beam method was used with incident electron energies from 25 to 250 eV. The energy and angular range of secondary electrons covered from 1.0 eV to one-half of the difference between the incident energy and ionization potential and from 12° to 156°, respectively. The present results have been compared with the previous measurements and considerable discrepancies were found.