Translational and vibrational energy release in nitrogen recombinative desorption from Cu(111)

Nitrogen recombinative desorption from Cu(111) has been investigated using resonance enhanced multiphoton ionisation and ion time of flight measurements to obtain the energy release into N2 product vibrational and translational excitation. N2(ν = 0) desorbs from a 700 K surface with a mean translational energy perpendicular to the surface of 4.2 eV, a substantial fraction of the N2 bond strength. The desorbed molecules are vibrationally hot, with a population ratio P(ν = 1)/P(ν = 0) = 0.52, corresponding to a vibrational temperature of 5100 K, and N2(ν = 1) shows a slightly lower translational energy release than the ground state.