COLLISIONS OF MONOENERGETIC ELECTRONS WITH NO2 - POSSIBLE LOWER LIMITS TO ELECTRON AFFINITIES OF O2 AND NO

The yields of O-, NO-, and Of ions produced by dissociative attachment of electrons to NO2 have been studied as a function of the electron energy from 0 to 6 eV. A modulated retarding-potential- difference technique permitted electron-energy resolution of approximately 0.1 eV. The measured appearance potentials for NO- and Of were found to be consistent with an electron affinity of >0.65 eV for NO and >1.1 eV for O2. These lower limit measurements to the electron affinities of Oi and NO are discussed in relation to previous studies of electron attachment to these molecules.