Townsend formula

No attempts to calculate those limiting surface field intensities or gradients for small particles have been reported in the literature. However, point-to-plane corona has been studied in detail. Loeb (L8) has proposed a method for calculating positive corona threshold limits making use of established values of the Townsend first ionization coefficient. Loeb s threshold formula is... 

Under these circumstances we are very much tempted to conclude that the structural formula suggested by Townsend and Robins for 3-methylguanine is erroneous and that probably this molecule corresponds to a more classical type of tautomer. This could be, for example, the N(3)H-N(7)H one (63). As can be seen in Table XVI the properties of such a tautomer would be more reasonable and from the spectral point of view more in agreement with the observed properties of the substance. The distinction between 63 or the N(3)H-N(9)H tautomer could easily be made on the basis of dipole moment determination. The N(3)H-N(7)H seems to be the more probable of the two. 

From Formula 2 it is apparent that aXK depends on the overlap between QXK and E1/2f(E). For a particular gas, however, f(E) and E, the mean electron energy, are functions of X/n, the Townsend parameter. The mean electron energy is given by... 

For Reaction R4 the rate coefficient Pxx+A computed from Formulae 2.1 and 10 agrees closely with the values found from experiment (usually denoted as a/n or a/p) and long known as the Townsend coefficient of ionization (24). For Reaction R5 and for similar reactions generating the radiative species H2 (a 3V) and N2 (C 3nu), a similar concordance is found between experiment and the predictions of theory (16, 58, 59, 61, 74). In discussing possible interpretations of Kirkby s data for positive column reaction, it is assumed that the Maxwellian form for /(E) is a valid approximation to the true distribution. 

In seeking a quantitative interpretation of the rate coefficient for the formation of water, Pwa/n, Kirby invoked the theory of electron-impact reaction formulated first by Townsend (85, 86). In terms of the account given earlier in this paper, the formal statement of that early theory can be seen to approach closely Formulae 2 and 12 when the following qualifications are made ... 

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