Electron recombination and diffusion in CO at elevated temperature

Abstract

The electron time decay in an afterglow following a short pulsed d.c. discharge in CO has been investigated using microwave diagnostic techniques. The gas was heated to an average temperature of 775 °K. Two-body electron-ion recombination and ambipolar diffusion were found to be the only important electron removal mechanisms present in the pressure interval [Formula: see text] Torr with the rate constants α r = 3.9 × 10 −7 cm 3 s −1 and D a p 0 = 372 cm 2 s −1 Torr respectively. If we postulate a T −γ dependence for α r , comparison with room temperature results yields γ = 0.57. The diffusion coefficient appears to increase strongly with temperature based upon an estimated zero field mobility for CO + in CO at 273 °K found in the literature.