Influence of irradiation on discharge current in an ozonizer
TL;DR: In this article, the principal characteristics of the effects of irradiation on the discharge current in an ozonizer were explained and extended by taking into account the role played by the negative ions formed in the discharge space.
Abstract: The paper outlines the principal characteristics of the effects of irradiation on the discharge current in an ozonizer. The ``electronic surface charge theory'' of the effect developed by Deb and Ghosh, on a suggestion of Mitra, is explained and is further extended by taking into account the role played by the negative ions formed in the discharge space. It is assumed that the effect of irradiation is to decrease the charges deposited on the surface and to increase those in the volume. The former reduces the discharge current due to the neutralization of the surface charges and the latter increases the main discharge current due to the applied voltage. The net effect is generally a decrease if conditions are favorable for the capture of the electrons in the volume by neutral gas molecules, leading to the formation of negative ions. In all other conditions the effect is generally an increase. It is shown that the theory, in its extended form, is able to account for the origin and the characteristics of bot...
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TL;DR: In this article, it is shown that ozone is composed only in the streamers and not on the walls of the ozonizer, and that opposite surface charges are formed by electrons and positive ions on the dielectrics of the Ozonizer.
Abstract: Die stille elektrische Entladung in Ozonisatoren setzt sich aus vielen einzelnen, kleinen Entladungsfunken zusammen. Der Strom zeigt daher eine grose Anzahl von Entladungsspitzen, die insgesamt den Wirkstrom darstellen. Mit einer photographischen Methode (Lichtenberg-Figuren) wird gezeigt, das in jedem Entladungsfunken durch Elektronen und positive Ionen entgegengesetzt gepolte Flachenladungen auf den Ozonisatordielektriken gebildet werden. Es wird ein neues Ersatzschaltbild angegeben, mit dem eine zutreffende theoretische Beschreibung der stillen elektrischen Entladung moglich ist. Aus Untersuchungen an Ozonisatormodellen folgt, das die Ozonbildung nicht an den Ozonisatorwanden, sondern in den Entladungskanalen stattfindet.
The silent electric discharge of ozonizers is composed of a great number of discharge streamers; therefore in the current one can see a lot of peaks, which in sum give the active current. By a photographic method (Lichtenberg figures) it can be shown, that from each streamer opposite surface charges are formed by electrons and positive ions on the dielectrics of the ozonizer. A new equivalent circuit gives an accurate theoretical description of the silent electric discharge. By investigations of ozonizer models it follows, that ozone is composed only in the streamers and not on the walls of the ozonizer.
11 citations
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TL;DR: In this article, the photovariation, enhancement, and diminution of the discharge current in halogen-filled discharge tubes, excited by a transformer discharge of 50-cycle potentials using external sleeve electrodes, is associated with the electrode regions and predominantly with the high-tension electrode region.
Abstract: It has been verified that the Joshi effect (the photovariation, enhancement +Δi, and diminution −Δi of the discharge current i) in halogen-filled discharge tubes, excited by a transformer discharge of 50-cycle potentials using external sleeve electrodes, is associated with the electrode regions and predominantly with the high-tension (HT) electrode region. The techniques of (i) partial irradiation and (ii) varying the irradiated length of the discharge column starting from either electrode were used and the Joshi effect was observed with (i) a reflection galvanometer and (ii) a cathode-ray oscillograph. The effect of scattered light from the illuminated glass side of the discharge tube and the gas or vapor reaching either electrode was minimized by increasing the spacing of the electrodes and using low gas pressures.It has also been verified that the applied field is one of the factors that determine the magnitude and sign of the Joshi effect. The maximum magnitude of +Δi was observed at the breakdown val...
1 citations
References
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TL;DR: In this paper, the properties of the upper atmosphere and in particular of the ionosphere and of the night-sky emission are outlined and the fundamental processes that might be involved are discussed.
Abstract: The properties of the upper atmosphere and in particular of the ionosphere and of the night-sky emission are outlined. The fundamental processes that might be involved are discussed. Various suggestions regarding the production of the layers are considered in detail and the main difficulties indicated. The theory of the equilibrium of the layers is built up and the outstanding problem of explaining the rate of disappearance of electrons is emphasized. Current views on the origin of the night-sky light are studied critically and serious discrepancies are shown to exist. Other possibilities are examined.
88 citations
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TL;DR: In this article, the fraction of the collisions between electrons and molecules which result in the attachment of the electron to form a negative ion has been measured in air and oxygen as a function of the average electron energy, the gas pressure, and the moisture content.
Abstract: By a new method, the fraction $h$ of the collisions between electrons and molecules which result in the attachment of the electron to form a negative ion has been measured in air and oxygen as a function of the average electron energy, the gas pressure, and the moisture content. In oxygen $h$ had a minimum at 0.9 volts average electron energy, and increased with either increase or decrease of the energy from this value. In air $h$ increased as the average electron energy was reduced below 0.9 volts. The absolute value was about 0.4 of that predicted from the value in ${\mathrm{O}}_{2}$ assuming simple additivity, but this difference is possibly within the limits of error. The variation with electron energy and the order of magnitude of $h$ are in agreement with Bailey's results for air. On the other hand, a rapid increase in $h$ with increase in pressure at constant electron energy was found at low energy, while Bailey's results, which seem more reliable, show no variation with pressure. In ${\mathrm{H}}_{2}$O $h$ is of the same order of magnitude as in ${\mathrm{O}}_{2}$, but in mixtures of ${\mathrm{H}}_{2}$O and ${\mathrm{O}}_{2}$ $h$ is much larger than in either alone, showing that here at least the attachment process is complex.
49 citations
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01 Oct 1951
TL;DR: In this paper, the current flow through a 50 c/s, electrodeless discharge in a short cylindrical glass vessel with plane electrodes at the ends filled with chlorine at 5-50 mm Hg was investigated with an oscillograph.
Abstract: The current flowing through a 50 c/s, electrodeless discharge in a short cylindrical glass vessel with plane electrodes at the ends filled with chlorine at 5-50 mm Hg was investigated with an oscillograph It consists essentially of between one and fifty or more distinct pulses per half cycle, the number increasing with the voltage At sufficiently large voltage these pulses cover the greater part of a half cycle including the instant of zero voltage By irradiating the discharge with light from an incandescent lamp the average pulse height decreases, radiation below 4,800 A being strongly active By irradiating only the central portion of the vessel the pulse height does not change Irradiating one wall reduces the height of the pulses in every second half cycle, namely those pulses whose electron avalanches start from that wall Once the discharge starts, electric charges collect on the inner surface of the vessel Each current pulse consists of a series of avalanches which develop between small areas of the inner glass walls One such area may discharge within a half cycle in several steps The time variation of the applied field, the wall-charge field and the field in the gas are discussed and a new mechanism is developed which appears to apply to discharges between solid dielectrics At room temperatures, chlorine molecules form an adsorbed layer, several molecules thick, on the glass walls Irradiation produces photo-dissociation of Cl2, the atoms being effective in capturing electrons in this layer where slow electrons and many-body collisions are likely This reduction of the number of secondary electrons reduces the pulse height Adsorbed molecular gas layers also explain observations at higher temperatures At higher voltages the interval between two successive pulses becomes so small that one pulse reduces the height of the following one This is probably due to metastable Cl atoms and resonance radiation diffusing to the wall where they cause dissociation of molecules in the adsorbed layers, the chlorine atoms capturing electrons as before It also explains why at high voltages the effect of irradiation becomes insignificant
39 citations
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TL;DR: Mitra as discussed by the authors proposed a new theory that the afterglow of active nitrogen is due to recombination of ionized nitrogen molecules with free electrons, but it seems doubtful whether it can explain all the facts, and it is unlikely to receive general acceptance.
Abstract: THE afterglow of nitrogen in a discharge tube was first observed in 1884, and attempts to explain it have been made at intervals for the last thirty-five years. In the first, and larger, part of this book the observations on active nitrogen during this period are reviewed. This part is well and stimulatingly written ; the discussion of the work of Lord Rayleigh, Willey, Kaplan and others on the production, decay and chemical effects seems particularly well done and makes interesting reading ; on the spectroscopic side Prof. Mitra seems on slightly less firm ground. He appears to have missed the work of Spealman and Rodebush showing that the yellow-green air afterglow is due to reaction between nitric oxide and atomic oxygen, not between nitrogen peroxide and ozone as stated in the book ; but the bibliography on the nitrogen afterglow itself seems fairly complete. Existing theories of the afterglow are briefly stated and receive some well-justified criticism. The second part of the book gives Prof. Mitra's new theory that the afterglow is due to recombination of ionized nitrogen molecules with free electrons. The case for this simple theory is put clearly ; but it seems doubtful whether it can explain all the facts, and it is unlikely to receive general acceptance. The chief value of the book lies in its clear readable summary of experimental work. Active Nitrogen—A New Theory By Prof. S. K. Mitra. (Joykissen Mookerjee Medal Lecture for 1945.) Pp. vi + 73. (Calcutta: Indian Association for the Cultivation of Science, 1945.) n.p.
34 citations
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TL;DR: Light effect in chlorine under electrical discharge: change of the wave form due to Irradiation as discussed by the authors was the first work to consider the effect of electrical discharge on chlorine.
Abstract: Light-Effect in Chlorine under Electrical Discharge: Change of the Wave Form due to Irradiation
30 citations