Investigations of ionisation growth in gas mixtures

Abstract

Ionisation growth in the gas mixtures, N2:NO, N2:He and CO2:N2:He has been studied using combined spatial and temporal measurement techniques. Observations in N2:NO mixtures confirmed that reliable information about primary ionisation processes could be obtained even in the presence of large secondary surface ionisation processes and extensive studies of the two ternary mixtures CO2:N2:He (1:1:8) and (1:2:3) and one binary N2:He (1:9) mixture have been undertaken. Primary and secondary ionisation coefficients covering the range of values 60<or=E/N<or=1500 Td have been measured and for the CO2:N2:He mixture have been compared with other recent measurements and computations. The temporal data obtained in N2:He have been used to determine an 'effective' diffusion coefficient. Interpretation of the present result and that of Gusinow and Gerber (1970) in terms of an 'effective' value appropriate to a mixture of He(23S) and He2(3 Sigma uP) particles is considered.

Electron swarm parameters in a CO2:N2:He:CO gas mixture

“…Lakshminarasimha et a1 (1976) and Haydon and McIntosh (1978) have shown that the ionisation rate is highly dependent on the gas composition in C02:N2:He gas mixtures.…”

Laser-induced optogalvanic effects under prebreakdown conditions in neon

“…The temporal growth of the ionisation current was measured by chopping the uv lamp and observing the resultant current waveform (see e.g. figure 1, Haydon and McIntosh 1978). The current decay was measured after the lamp had been switched off, to avoid complications from the start-up transient after the lamp was switched on.…”