Production and loss of H atoms in a microwave discharge in

Two-photon laser-induced fluorescence (LIF) is used to study the production and loss of H atoms in a pulsed microwave discharge in over the pressure range 1-50 Torr. Absolute measurements of the H atom density are made at the end of the pulse. These measurements were calibrated using a new technique based on the decay rate of the LIF signal. The temporal variation of emission during pulsing of the discharge is used to estimate the rate of dissociation of , which compares well with the predictions of a one-dimensional model for the electron energy distribution function. This measurement also gives the wall recombination probability for H atoms, which is compared with that obtained by LIF measurement of the decay of the H atom density in the pulse afterglow.