Modelling of transport phenomena in gases

The major outcome of this PhD work consist in the development and the implementation of the method for the calculation of the reduced mobility of the ions in low reduced electric field. The main interest were ions generated in the negative corona. The calculated results of the reduced mobility served to more accurate analysis of the products in the negative corona discharge by the ion mobility spectrometry. To accomplish this goal the following tasks have been fulfilled: (1) We have designed the parameters of the calculation and the method of the data processing to obtain the desired rateability of the results. The accuracy of the model has been verified for the known results of the atomic ion in atomic gas. In the case of the two-atom ion, we have observed the dependence of the mobility on the tangential component of the potential. The obtained results correspond to the previous result within the mutual errors. (2) We calculated the reduced mobility of the ion generated by the negative corona discharge. Namely, NO₃^- a NO₂^- in nitrogen a NO₃^-, NO₂^-, O₃^-, CO₃^- a N₂O₂^- in oxygen. We have compared the calculated values to other theories and experimental results. In the case of the reduced mobilities in the nitrogen the results underestimate the mobility of the ions. It is caused probably by the cutoff potential approximation. In contrast, the final mobility in the oxygen are slightly higher than the expected values. The probable reason lies in the inaccurate intermolecular potential. (3) In the case of the ion N₂O₂^-, we have observed the influence of the ion structure on the reduced mobility. Our calculation predicted the higher mobility of the C2v ion structure than the trans structure. (Author)