Measurements and calculations of electron swarm coefficients in N2-CO2 mixtures
Résumé
The electron drift velocity ve , density-normalized ongitudinal diffusion and effective ionization coefficients (α−η)/N in the N2-CO2 mixtures have been measured for E/N from 1 Td to 350 Td, for 10-100% N2 concentrations. These swarm data, including the transverse diffusion coefficient and the mean electron energy, have been calculated over a wider range of E/N from 1 Td to 1000 Td, using a multi-term solution of Boltzmann equation, based on fitted sets of collision cross sections of electrons interacting with N2 and CO2. We have found an excellent agreement between measured and calculated ve, while the values of NDL agree well only at the higher E/N portion of the range of overlap. Even though the measured density-normalised effective ionisation coefficients (α−η)/N agree very well in trend, they turned out to be slightly smaller that those calculated. The calculations provide now reliable data over a wide range of E/N.