Ionization growth in carbon dioxide

Abstract

Current growth measurements have been carried out in carbon dioxide for E/N (electric field/gas number density) values between 84*10-17 and 166*10-17 V cm2 and N values between 4.5*1017 and 220*1017 cm-3. Ionization and attachment coefficients have been obtained which agree with the results of other workers at the lower pressures while the higher pressure results provide new data for carbon dioxide. The results of sparking potential measurements indicate Paschen's Law is obeyed and secondary ionization coefficients have been calculated. A decrease in the initial photoelectric current with increasing E/N and N has been observed.

Drift Velocity and Longitudinal Diffusion Coefficient of Electrons in CO2?Ar Mixtures and Electron Collision Cross Sections for CO2 Molecules

“…The electron drift velocity measured in pure CO 2 (Hasegawa 1994) and the vibrational cross sections derived in the preceding section enabled us to determine elastic momentum transfer cross section over the energy range 1-30 eVe The resultant cross section is quite close to the measurement of Register et ale (1980) except near 4 eVe At the same time, the Townsend ionisation coefficient was compared with published measurements (Conti and Williams 1975;Alger and Rees 1976) and electronic excitation cross sections were determined. Electronic excitation cross sections for two thresholds at 7 and 10·5 eV were assumed (Hake and Phelps 1967).…”

“…4. Townsend's first ionisation coefficient in pure C02: solid curve, using the present cross sections; solid circles, Alger and Rees (1976); and open circles, Conti and Williams (1975).…”

“…The swarm parameters in the mixtures are analysed by using a multi-term Boltzmann equation analysis (Robson and Ness 1986) and then a set of electron collision cross sections for the CO 2 molecule is determined. Electron swarm parameters in pure CO 2 (Elford andHaddad 1980 andHasegawa 1994 for the electron drift velocity, Conti andWilliams 1975 andAlger andRees 1976 for the ionisation coefficient) are also analysed using the newly derived vibrational cross sections. Then the elastic momentum transfer cross section for the CO 2 molecule is derived up to a maximum energy of 30 eVe These cross sections are also compared with published cross sections from various sources.…”

Influence of O2 on the dielectric properties of CO2 at the elevated temperatures

“…measurements by Davies. 63 However, the measurements by Davies only involved a reduced electric field strength range from 75 Td to 100 Td, compared with those by Alger and Rees, 60 Conti and Williams', 61 Risbud and Naidu. 68 The present calculations show a good agreement.…”

“…Earlier data sorted by Gallagher 69 for the attachment coefficient under different electric field strength in CO 2 at room temperature were reported, measure by Alger and Rees, 60 Conti and Williams, 61,62 Davies, 63 and Moruzzi and Price, 64 and calculated by Davies, 63 Kucukarpaci and Lucas, 65 and Hake and Phelps. 66 The ionization coefficients of CO 2 were measured by Alger and Rees, 60 Conti and Williams, 61,62 Davies,63 Laksminarasimha and co-workers, 67 and Risbud and Naidu, 68 and calculated by Kucukarpaci and Lucas, 65 and Davies. Stoller 4 briefly calculated the effective ionization coefficient of hot CO 2 .…”