The Mobility of Negative Ions in $\hbox {CF}_{3} \hbox {I}$ , $\hbox {CF}_{3}\hbox {I}{-}\hbox {N}_{2}$

Using a pulsed Townsend technique, the drift velocity and the mobility of positive ions in C₂F₄ and C₄F₈ and those of negative ions in C₂F₆, CHF₃, and CF₃I and its mixtures with N₂, Ar, and Xe are reported. The overall range of the density-normalized electric field is 4-600 times10^{-17 - V}ldrcm². Ion identification is provided by means of previous studies on partial ionization and electron attachment. Thus, it is suggested that the predominant drifting ion in the discharge is C₂F₄ ⁺ for C₂F₄ and c-C₄F₈, F^- for C₂F₆ and CHF₃, and I^- for CF₃I. The use of more comprehensive theories of ion motion considering the influence of a permanent dipole moment (CHF₃ and CF₃I) has provided reasonable agreement between low-field measured and calculated mobilities. The mobility of negative ions in CF₃I-N₂, CF₃I-Ar, and CF₃I-Xe mixtures agrees reasonably well with the predicted values by Blanc´s law.