Efficient production of O- by dissociative attachment of slow electrons tohighly excited metastable oxygen molecules

In this paper, the mechanism for efficient production of O- in the afterglo w of a low-pressure and high-density oxygen plasma has been described. We p roposed a new production process, the dissociative attachment of slow elect rons to highly excited metastable oxygen molecules O-2 (A(3) Sigma(u)(+), A '(3) Delta(u), C-1 Sigma(u)(-)). The electron attachment frequency has been obtained from the experimental results, and was significantly high for the electron temperature of less than 2 eV. The cross section, sigma(DA), for this process was evaluated by a quantum mechanical approach. sigma(DA) at 0 .1 eV was larger by two-orders of magnitude than the peak value at 6.7 eV f or the ground state O-2 (X-3 Sigma(g)(+)). The enhancement of the electron attachment frequency at low temperature can be explained by dissociative at tachment of slow electrons to O-2 (A(3) Sigma(u)(+), A'(3) Delta(u), c(1) S igma(u)(-)).