Electron transport properties and collision cross sections in C2F4

Abstract

We have measured the electron drift velocity, longitudinal diffusion coefficient, and ionization coefficient in tetrafluoroethene (C2F4). Using these data and the results of ab initio calculations of the elastic, momentum-transfer, and neutral-excitation cross sections, along with measurements of the partial ionization cross sections, we have performed a swarm analysis in order to construct a self-consistent set of electron impact cross sections for C2F4. The swarm analysis consists of solutions to Boltzmann’s equation for electrons in C2F4 for values of E/N⩽500 Td and direct Monte Carlo simulation of electron transport in C2F4 for 500 Td⩽E/N⩽2000 Td. We present an analysis and discussion of the sensitivity of cross sections derived from swarm data to uncertainties in the electron transport measurements. We also discuss the failure of the two-term spherical harmonic solution to Boltzmann’s equation for E/N>500 Td, which necessitated the use of Monte Carlo simulations for high values of E/N.