INSITU CALIBRATION FOR ELECTRIC-FIELD MEASUREMENTS IN GLOW-DISCHARGE PLASMAS BY LASER-INDUCED FLUORESCENCE USING THE OPTOGALVANIC TECHNIQUE

We proposed and performed an in-situ calibration of electric field determination in glow-discharge plasmas based on the Stark effect, to relate ratios of laser-induced fluorescence (LIF) intensities (forbidden/allowed) with electric fields E, where accurate E values were measured by the laser optogalvanic (LOG) method. The results were compared with Bell Lab Group static calibration, and yielded 30% lower E value at a given fluorescence intensity. It is discussed, by the aid of solutions of rate equations for the LIF processes, that the present calibration is more accurate at higher electric field (E > 100 V/mm) than that obtained by extrapolation of Bell Lab Group results at lower field (E < 94.3 V/mm). Also, in the course of this comparision, the value of electric dipole moment for BCl was estimated to be mu = 0.93 +/- 0.02 Debye.