Determination of the fraction of excited iodine atoms produced by dissociation of iodides in a self-sustained pulsed discharge

Based on the measured absorption coefficient for the atomic iodine transition in the mixtures of iodides with helium we have determined the fractions of the excited atomic iodine produced by dissociation of CH₃I, CF₃I, i-C₃F₇I, C₂F₅I and C₂H₅I molecules in a self-sustained pulsed discharge. In the 1:(3–15) mixtures of iodides with helium at the pressure 133–400 Pa these fractions amount to 0.29 for CF₃I and CH₃I, 0.2 for i-C₃F₇I, and 0.31 for C₂F₅I and C₂H₅I. The accuracy of determining the excited iodine fraction is 10%. The numerical modelling is carried out for the mixtures containing CF₃I. The calculated values of the excited iodine fraction for the mixture with CF₃I agree well with the experimental data.