Electron attachment to oxygen in nitrogen buffer gas at atmospheric pressure.

We have carried out experimental and theoretical studies of three body electron attachment (TBEA) to O 2 in N 2/O 2 mixtures. We have applied three different experimental methods to determine the apparent rate constant k for TBEA to O 2 for reduced electric fields E/ n from 0.5 Td up to 4.5 Td and O 2 concentrations from 0.02% up to 3%. From the apparent rate constant k we have evaluated three body rate constant for electron attachment to O 2 in pure O 2$$\left( {k_{O_2 } } \right)$$ and in pure N 2$$\left( {k_{N_2 } } \right)$$ . The comparison of present data with former studies shows that the former values of $$k_{N_2 }$$ overestimated the efficiency of this reaction, while in case of $$k_{O_2 }$$ we have found agreement with earlier studies. We have solved numerically the Boltzmann equation of the electrons and calculated the values of k, $$k_{N_2 }$$ and $$k_{O_2 }$$ using well established cross sections. Using the known collision cross section set for TBEA to O 2, very good agreement between calculated and measured results for $$k_{O_2 }$$ was found, while in the case of k and $$k_{N_2 }$$ we had to introduce a scaling function, which describes the decrease of the efficiency of TBEA to O 2 in presence of N 2 and the dependence of the scaling function on E/ n was determined. [ABSTRACT FROM AUTHOR]