Dissociative attachment in electron-stimulated desorption from condensed NO and N2O

We have measured the intensity of O- ions produced by low-energy electrons (1--20 eV) impinging on NO and N2O molecules condensed on a polycrystalline platinum surface held at 17 and 40 K. In condensed NO (i.e., in the dimerized form N2O2), the energy dependence of the O- yield exhibits four broad peaks within the range 5--20 eV whereas in condensed N2O two peaks are observed at 9.4 and 16.4 eV. The linearity of O- production near the peak energies with coverage indicates the presence of a first-order mechanism which we ascribe to the decay of transient anion states (i.e., electron resonances) into the dissociative attachment channel