Electron-molecule collision ionization in hydrogen and deuterium

Electron Excitation, Dissociation and Ionization of H2, D2, T2, Simple Hydrocarbons and Their Ions

“…Experimental total (gross) ionization cross-sections have been obtained by Rapp and Englander-Golden [19] from threshold up to 1000 eV, quoting an uncertainty of 4.5%. These measurements are in excellent agreement with older data by Tate and Smith [20] and of Cowling and Fletcher [21], but are about 20 percent larger than values obtained by Schram et al [22]. See also the bibliography of Kieffer and Dum [23] and their review article [24].…”

“…In the case of ionization an isotope effect is present near the threshold only, which probably has its origin in the predissociation and preionization phenomena discussed above. In Table I1 we give the ratios of ui(D2)/ai(H2) as derived from the data of Rapp and Englander-Golden [19], Cowling and Fletcher [21] and Schram et al [22]. It is clear that near threshold ui is larger for D2 than for H2, as predicted theoretically, but that towards higher energies (> 25 eV), the cross-sections become almost equal.…”

Scanning drift tube measurements of electron transport parameters in different gases: argon, synthetic air, methane and deuterium

“…The reduced ionization coefficient as a function of E/N, in comparison with values obtained by other authors is presented in figure 9(c). The data of Rose [56], Cowling and Fletcher [57], as well as Davies et al [58] were obtained via measurements of current growth in drift tubes with variable gap lengths. All data sets for N / α , including ours, agree reasonably well over the whole domain of E/N.…”

Multi-gap Pseudospark Switches for High Voltage Applications

“…These differences in the Paschen breakdown characteristics are attributed to a difference in the secondary electron emission coefficient γ, but there are no quantitative numbers given for this difference. An early explanation [18] claimed for a difference in the values of the reduced primary ionization coefficients α/p at relatively low reduced electric fields E/p, but for much higher E/p-values, as typical for modern switching devices, the differences in α/p are negligible for H 2 and D 2 [19]. As the reports on the technology of the thyratron ad related literature deliver apparently only insufficient data, a more general search for cold cathode Paschen breakdown curves in H 2 and D 2 yielded only three more papers [20,21,22].…”