LXCat is an open‐access platform (http://www.lxcat.net) for curating data needed for modeling the electron and ion components of technological plasmas. The data types presently supported on LXCat are scattering cross sections and swarm/transport parameters, ion‐neutral interaction potentials, and optical oscillator strengths. Twenty‐four databases contributed by different groups around the world can be accessed on LXCat. New contributors are welcome; the database contributors retain ownership and are responsible for the contents and maintenance of the individual databases. This article summarizes the present status of the project.

Abstract. In this contribution, the electron swarm parameters of the hydrofluoroolefine HFO1234ze, systematic name 1,3,3,3-Tetrafluoro-1-propene, are experimentally investigated. The analysis of the electron avalanche current measured in a pulsed Townsend experiment yields the effective ionization rate coefficient, the electron drift velocity and the longitudinal electron diffusion coefficient. The subsequent ion current is analyzed as well, to obtain separately the ionization and attachment rate coefficients. Measurements in pure HFO1234ze at different pressures show that the effective ionization rate is strongly influenced by three-body attachment and the three-body attachment rate coefficient is derived.

The electrical insulation properties of pure C 4 F 7 N and of C 4 F 7 N/N 2 and C 4 F 7 N/CO 2 mixtures are investigated in a pulsed Townsend setup. The electron rate and transport coefficients and the density-reduced critical electric field of these mixtures are obtained, and a synergy effect is observed in C 4 F 7 N/N 2 and C 4 F 7 N/CO 2 mixtures. The total electron attachment cross section of C 4 F 7 N is estimated based on the attachment rate to C 4 F 7 N in diluted C 4 F 7 N/N 2 , C 4 F 7 N/CO 2 and C 4 F 7 N/O 2 /CO 2 mixtures. Measurements in pure C 4 F 7 N at pressures of a few hundred pascal show that ion kinetics play a major role in C 4 F 7 N discharges and that further modelling is required to assess the electric strength of C 4 F 7 N at high pressures.

The electrical insulation properties of pure C 5 F 10 O and of C 5 F 10 O/N 2 and C 5 F 10 O/CO 2 mixtures are investigated in a pulsed Townsend setup. The electron rate and transport coefficients and the density-reduced critical electric field of these mixtures are obtained, and a synergy effect is observed in in C 5 F 10 O/N 2 and C 5 F 10 O/CO 2 mixtures. The total electron attachment cross section of C 5 F 10 O is estimated based on the attachment rate to C 5 F 10 O in diluted C 5 F 10 O/N 2 and C 5 F 10 O/CO 2 mixtures.

We follow up on our previous publication on C 4 F 7 N and investigate the ion kinetics influencing C 4 F 7 N discharges with a pulsed Townsend experiment. The measured current signals at pressures between 6 and 69 kPa, in the range of density-reduced electric fields E/N from 500 to 1050 Td, show evidence of three anions: one long-lived anion with a detachment rate coefficient in the order of 10 −20 m 3 s −1 , a presumably non-detaching anion, and a short-lived anion with a detachment rate coefficient in the order of 10 −17 m 3 s −1. We obtain the corresponding rate coefficients for ionization, attachment and detachment in C 4 F 7 N. Using these results, we calculate a corrected value of the effective ionization rate coefficient (ν eff /N) * , taking into account detachment from negative ions. It results in a corrected value of the density-reduced critical electric field strength (E/N) * crit = 785 ± 15 Td, much lower than the previously obtained value of (E/N) crit = 975 ± 15 Td, which is valid only when electron detachment is negligible, i.e. for low pressure and small geometric distance. To find which value is most relevant for electrical insulation, we perform breakdown voltage measurements in homogeneous electric fields in C 4 F 7 N at 5 to 65 kPa. We compare the measured density-reduced breakdown field strength (E/N) bd to that calculated using the streamer criterion with the presently obtained rate coefficients, including electron detachment. We find excellent agreement between the measured and calculated (E/N) bd .