Reduced ionization coefficients in low-current dc discharge in freons of a new generation

In this paper we present results for reduced ionization coefficients (alpha/N, N-gas density) obtained from the breakdown voltage and emission profile measurements in low-pressure dc discharges in two freons: 1,1,1,2-tetrafluoroethane (R134a) with the chemical formula CH2F-CF3 and 2,3,3,3-tetrafluoropropene (HFO1234yf) with the chemical formula CH2=CFCF3. Our results for alpha/N are determined from the axial emission profiles in low-current Townsend discharge and lay in the intervals of reduced electric fields E/N (E-electric field, N-gas density), from 2.7 to 5.9 kTd for R134a and from 5 to 23 kTd for HFO1234yf. We also provide a comparison of our experimental results with those from the available literature.