Recombination of vibrationally cold N2+ ions with electrons.

Abstract

Recombination of vibrationally cold N2+ ions with electrons was studied in the temperature range of 140-250K. A cryogenic stationary afterglow apparatus equipped with cavity ring-down spectrometer and microwave diagnostics was utilized to probe in situ the time evolutions of number densities of particular rotational and vibrational states of N2+ ions and of electrons. The obtained value of the recombination rate coefficient for the recombination of the vibrational ground state of N2+ with electrons is αv=0 = (2.95 ± 0.50) × 10-7(300/T)(0.28±0.07)cm3s-1, while that for the first vibrationally excited state was inferred as αv=1 = (4 ± 4) × 10-8cm3s-1 at 250K.