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Please follow the links to view the publication.The twenty-sixth Kelvin Lecture. “The molecular structure of dielectrics”
http://dl-live.theiet.org/content/journals/10.1049/jiee-1.1935.0203
Sources of ionisation in high-pressure gases above 2000°K
http://dl-live.theiet.org/content/journals/10.1049/piee.1964.0266
Previous experiments with inert gases at high pressure between coaxial graphite electrodes, at temperatures above 2000° K, have shown unexpectedly high electrical conductivities for quite small voltages across the electrodes. In the present experiments the influences of electrode geometry and supply frequency are examined, and the gas pressure is steadily reduced until the classical regions of low pressure (several mmHg) and high vacuum (mean free path ≫ electrode spacing) are reached. Spectroscopic observations confirm the presence in the gas of ‘seed’ impurities from the electrodes, and results are described for the deliberate addition to the gas of aluminium vapour as a ‘seed’ element.Rubidium atomic frequency source having small size and fast warm up
http://dl-live.theiet.org/content/journals/10.1049/el_19700509
An experimental miniaturised rubidium frequency source which has been built in a volume of a little more than 100 in<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sup> provides a stability of better than 1 part in 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sup> over one year and a warm-up time of 5 min. This long-term stability lies between that of a good crystal frequency standard and a high-grade rubidium atomic frequency standard.Growth of ionisation currents in the methyl halides
http://dl-live.theiet.org/content/journals/10.1049/el_19680043
The prebreakdown ionisation currents between parallel electrodes, <i xmlns="http://pub2web.metastore.ingenta.com/ns/">d</i> apart, were measured at fixed reduced fields as <i xmlns="http://pub2web.metastore.ingenta.com/ns/">d</i> was varied. Townsend alpha coefficients have been derived for CH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>F, CH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>Cl and CH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>Br for 26 < <i xmlns="http://pub2web.metastore.ingenta.com/ns/">E/p</i> < 60 V cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> torr<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup>. Appreciable negative-ion formation seemed absent in CH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>F and CH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>Cl, whereas a small but constant attachment coefficient, <i xmlns="http://pub2web.metastore.ingenta.com/ns/">η</i>/<i xmlns="http://pub2web.metastore.ingenta.com/ns/">p</i> = 0.015 cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> torr<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> was observed in CH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>Br.Electron detachment in oxygen
http://dl-live.theiet.org/content/journals/10.1049/el_19670113
A new experimental method for determining electron detachment (δ) coefficients in swarm conditions in gases is described. Data are given for oxygen at pressures of 20 and 40torr (<i xmlns="http://pub2web.metastore.ingenta.com/ns/">E/p</i>=40–50 <i xmlns="http://pub2web.metastore.ingenta.com/ns/">V</i> cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> torr<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup>). δ/<i xmlns="http://pub2web.metastore.ingenta.com/ns/">p</i> varies from 2×10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−3</sup> to about 1.3×10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−2</sup>cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup>torr<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup>.Electron detachment in sulphur hexafluoride
http://dl-live.theiet.org/content/journals/10.1049/el_19670319
Electron detachment in swarm conditions has been observed in SF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub> at an observed theshold of about <i xmlns="http://pub2web.metastore.ingenta.com/ns/">Elp</i> = 95V/cmtorr at a pressure of 5.2torr. The relevance of this process to various corona studies is discussed briefly.The forty-second Kelvin Lecture. Modern conceptions of the structure of matter
http://dl-live.theiet.org/content/journals/10.1049/pi-1.1951.0080
Statistical models for laser-induced ionisation of gases
http://dl-live.theiet.org/content/journals/10.1049/el_19660249
Previous calculations, assuming random (Poissonian) fluctuations in laser intensity, overestimate the lowest threshold fluxes required to induce ionisation breakdown. This may be corrected by replacing the Poisson distribution by a Polya distribution, which takes account of correlations between coherent photons.Townsend's first ionisation coefficient in compressed methane
http://dl-live.theiet.org/content/journals/10.1049/el_19650078
Townsend's first ionisation coefficient a has been determined in methane by three independent methods for a range of pressures between atmospheric and 14 atm absolute, thus extending the range of previous measurements to lower values of <i xmlns="http://pub2web.metastore.ingenta.com/ns/">E/p</i> and much higher pressures. It is confirmed that α/<i xmlns="http://pub2web.metastore.ingenta.com/ns/">p</i> is dependent only on the value of <i xmlns="http://pub2web.metastore.ingenta.com/ns/">E/p</i>.Effect of high-current pulsed discharges on SF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub> and C<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">5</sub>F<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sub>
http://dl-live.theiet.org/content/journals/10.1049/el_19660206
The effect of high-current pulsed discharges on the abundance of ion species produced by electron impact in SF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sub> and C<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">5</sub>F<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">8</sub> has been studied. In addition, the effect of the pulses on the electric strength of the gases has been determined.Laser and microwave interferometric study of recombination in a highly ionised helium plasma
http://dl-live.theiet.org/content/journals/10.1049/el_19660129
A 3.3 μm helium–neon laser and 2.25 and 8.6 mm microwave interferometer systems have been used to measure electron densities over the range 1.8 × 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">15</sup> to 8 × 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">11</sup> electrons/cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sup> in a decaying helium plasma without a confining magnetic field at gas pressures ranging from 82 mtorr to 1.2 torr. Collisional radiative recombination is considered to be the dominant mechanism of electron removal above a pressure of 700 mtorr.Ionisation and dissociation in CF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub>
http://dl-live.theiet.org/content/journals/10.1049/el_19650049
A mass-spectrometric reinvestigation of ionisation and dissociation in CF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub> was undertaken to deduce the probable value of the CF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub>–F bond strength. From studies of the appearance potentials for both positive and negative F and CF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">3</sub> ions a best value for the bond strength of 143 kcal/mole is deduced. Possible reasons for the abnormal low dielectric strength of CF<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">4</sub> are discussed.