A TALIF calibration method for quantitative oxygen atom density measurement in plasma jets

In this communication we propose a calibration method for two-photon absorption laser induced fluorescence (TALIF). It can be carried out without any addition or modification to the O atom TALIF set-up. It is based on the measurement of the collision quenching of the laser-excited state (3p 3 P 2 ) in a pure O 2 system in which a high dissociation degree can be achieved. Since the collision rate constant by O is largely lower than that by O 2 , the quenching rate can be correlated to the O density. The incertitude in this procedure is comparable to other calibration techniques. We have applied this method to the spatially resolved measurement of O atom density in an O 2 rf plasma jet.