6533b7d9fe1ef96bd126c004

RESEARCH PRODUCT

Estimation of the emission temperature of an electrodeless discharge lamp and determination of the oscillator strength for the I(2P3/2) 183.038 nm resonance transition

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Abstract The 183.038 nm resonance absorption transition of I( 2 P 3/2 ) has been studied using a flash photolysis set-up for gas-phase chemistry and a radio frequency powered electrodeless discharge lamp filled with iodine. The dependence of self-absorption and self-reversal on iodine partial pressure in the discharge volume was measured. The optimum iodine partial pressure, with self-absorption minimized and acceptable intensity, is determined to be approximately 2.5×10 −3 mbar. A method is described to estimate the temperature of the emitting atoms using direct measurements of relative absorption at different absorber concentrations. This yields an emission temperature of 923±50 K. Using this temperature, the oscillator strength for the I( 2 P 3/2 ) transition at 183.038 nm is determined to be f =(3.87±0.57)×10 −3 , corresponding to an absorption cross-section at the center of the line of σ=(5.42±0.8)×10 −14 cm 2 atom −1 . This shows a difference from one of two earlier measurements, but is close to the other. The remaining difference from the latter measurement is probably due to tendencies of opposite biases inherent to the experiments.