Characteristics of a condensed discharge through a capillary

1970 ◽  
Vol 12 (5) ◽  
pp. 598-602
Author(s):  
G. V. Ovechkin ◽  
I. A. Gael'
Keyword(s):  
Condensed Discharge

NEW EMISSION BANDS OF ,

1961 ◽  
Vol 39 (8) ◽  
pp. 1138-1145 ◽  
Author(s):  
Y. Tanaka ◽  
T. Namioka ◽  
A. S. Jursa
Keyword(s):  
Transition Formula ◽  
Condensed Discharge

Thirty-eight new bands of nitrogen were observed in the region 2050–3070 Å in an a-c. condensed discharge of neon mixed with a small amount of nitrogen. It was determined that these bands result from the transition [Formula: see text] of [Formula: see text].

scholarly journals The structure of the high pressure carbon bands and the swan system

1929 ◽  
Vol 124 (795) ◽  
pp. 668-688 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
High Pressure ◽  
High Pressures ◽  
Carbon Electrodes ◽  
High Dispersion ◽  
Pressure System ◽  
True Nature ◽  
Discharge Tubes ◽  
Condensed Discharge

The so-called high pressure “ CO ” bands—or high pressure carbon bands, as they are better called—were first found by Fowler* in 1910 in tubes containing carbon monoxide at relatively high pressures. The system was described as consisting of some six apparently double-headed bands degraded to the violet, their wave-lengths being approximately at— 6441 6420 } 5897 5878 } 5431 5413 } 5030 5015 } 4679 4663 } 4365 4353 } Å. U. In 1923 the conditions of production of this spectrum were further investigated by Merton and Johnson who obtained the bands with considerable strength by condensed discharges in capillary tubes fitted with carbon electrodes, and containing CO at pressures of 5 mm. and more. It was found that while the high pressure bands and the Swan bands were mingled in the light from the capillary of the tube, the former bands were isolated in bluish jets where the two ends of the capillary merged into the wider parts of the tube. Further observations indicated that the introduction of a little C0 2 destroyed the bands, but that the system re-apppeared after a few minutes, in which time presumably the carbon dioxide had been reduced to monoxide by the carbon electrodes. A reproduction of these bands photographed under low dispersion is given in the above-mentioned paper. No further experimental work appears to have been done on this system, and it has not been correlated with any other band system or assigned any place in the system of electronic levels of the CO molecule. We have therefore made an attempt to photograph the system under high dispersion with a view to fine structure analysis and identification of the molecular emitter. For this purpose large discharge tubes having a bore of about 15 to 20 mm. and a length of 60 or 70 cm. were used. These had at least one of the electrodes made of carbon and were fitted with side bulbs containing caustic potash and phosphorus pentoxide and a palladium regulator. The tubes were filled with carbon monoxide to such a pressure (probably 20-40 mm.) that a condensed discharge could just be forced through by the ¼ kilowatt 15,000 volt transformer used. Some of the tubes had large side flasks attached to them, increasing thereby the volume of gas in the tube, and giving the tubes a life of 4 to 6 hours during which the high pressure bands were emitted strongly. After some such period the pressure fell below the optimum value, and deposits of carbon had accumulated on the walls of the tube. Impurities such as hydrogen, carbon dioxide, and water-vapour were found to inhibit formation of the high pressure bands, and the tube always attained its best condition after running for about an hour (removing meanwhile any little hydrogen present through the regulator). Under these conditions the wide bore is practically filled with light, and presents a remarkable appearance, as of dense pale blue puffs of smoke (showing the high pressure system), threaded by a narrow green ribbon (showing the Swan system). If side tubes having a fair capacity ( e . g ., flasks) are attached to the discharge tube the high pressure glow is capable of diffusion into these. The appearance is suggestive of an afterglow emitter, but if this is its true nature it is of very short duration. Photographs of the H. P. bands were taken in times varying from 4 to 10 hours in the first order of a 21-foot grating. The green band in the neighbourhood of λ 5000 is exceedingly faint and was not attempted. Before considering the results -obtained it will be an advantage to summarise our present knowledge of the Swan spectrum and its emitter, with which it will subsequently be shown that the high pressure carbon system is intimately related.

scholarly journals Note on the oxygen afterglow

1935 ◽  
Vol 150 (869) ◽  
pp. 34-36 ◽  
Keyword(s):  
Electrodeless Discharge ◽  
Condensed Discharge

A paper on the oxygen afterglow by Stoddart appears in ‘Proc. Roy. Soc.,’ A, December 1, 1931. Many years ago I made an investigation on this subject. The title was perhaps not sufficiently explicit, and the paper escaped Stoddart’s notice. The conclusions reached are not in agreement with his, and I wish to draw attention to the old experiments, which appeared to me at the time, and appear still, to be definite and conclusive, as far as they go. Stoddart’s experiments seem to have been carefully carried out. But rather different experiments would, I believe, have led to a different conclusion. Before coming to the main point, it is necessary to deal with one preliminary matter. That is the meaning to be attached to the expression “Electrodeless discharge.” The phrase has usually been applied to the bright discharges obtained by J. J. Thomson, by electromagnetic induction, using the currents induced by a coil of wire wrapped round the tube, through which is passed the oscillatory discharge of a condenser. Dis­charges of this kind approximate to the condensed discharge in an electrode tube.

scholarly journals Spark spectra of bismuth, Bi II and Bi III. Evidence of hyperfine structure

1930 ◽  
Vol 129 (811) ◽  
pp. 579-588 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Term Structure ◽  
Optical System ◽  
Spectral Region ◽  
Considerable Progress ◽  
Condensed Discharge ◽  
Made In

Wave-lengths in the spectrum of a condensed discharge in heated bismuth vapour have been measured from λ 7050 A. to λ 2000 A. and those in the spectrum of a condensed spark between metallic terminals in hydrogen from λ 2000 A. to λ 1340 A. Hilger E 1 spectrographs, one with a glass and one with a quartz optical system, were used to study the first-mentioned spectral region and a Hilger vacuum fluorite instrument for the latter range. Light from a hot spark between metallic terminals in vacuo was photographed with a 1-metre vacuum grating spectrograph in order to investigate the spectrum below λ 1340 A. By a study of the frequencies of the wave-lengths thus obtained, considerable progress has been made in the identification of the multiplet term structure of bismuth II and of bismuth III. Confirmation of the correctness of assignment of wave-lengths to one or other of these spectra was obtained readily in most cases by varying the excitation of the sources of light by means of inductance in the secondary spark circuit.

scholarly journals On the absorption of light by electrically luminescent mercury vapour

1921 ◽  
Vol 100 (703) ◽  
pp. 149-166 ◽  
Keyword(s):  
Current Strength ◽  
Spectral Lines ◽  
Mercury Vapour ◽  
Selective Absorption ◽  
Similar Work ◽  
Photometric Observations ◽  
Absorption Of Light ◽  
Condensed Discharge ◽  
Photometric Measurements ◽  
Hydrogen Lines

Some of the earliest experiments on the absorption of light by electrically luminous gases were carried out by Pflüger, who, in 1907, investigated the absorption and reversal of the hydrogen lines by luminous hydrogen. He used a condensed discharge in a three-electrode tube, in which a short constriction provided the source of radiation and the wider and longer part the absorbing column. He succeeded in reversing H α . This work was followed up by Landenburg and Loria, who reversed H α and H β . In the same year Kuch and Retschinsky made experiments on selective absorption in mercury vapour lamps. They found that the ratio of the intensities of the spectral lines in the light from the mercury vapour depends on the thickness of the radiating layer of vapour, the intensities of neighbouring lines tending to equalise as the layer increases in thickness, a result which would follow from a relatively greater absorption of the stronger lines. They also made photometric measurements of the illumination from two mercury lamps, one of which was placed behind the other so that the light from the first had to traverse the second. They discovered that the radiation from the combination of lamps, arranged thus, was less than the sum of the radiations from each separately. Pflüger followed with photometric observations on the absorption of the lines 5461 Å. U., 4358 Å. U., 4047 Å. U., 5791 Å. U., and 5770 Å. U. Similar work was done by L. Grebe, on 5461 Å. U. and 4358 Å. U. In all these experiments with luminous mercury vapour, the current densities (of the order of 2 ampères per square centimetre) and the power developed in the absorbing arcs were considerable. Preliminary Experiments . It occurred to the present writers that very faintly luminous mercury vapour might possibly exhibit more marked selective absorption than had been observed by previous experimenters. It was, therefore, thought worth while to look for a means of maintaining a mercury arc of very low current density. This was found possible in a three-electrode tube in which two arcs were formed, having a common cathode. This arrangement, which is somewhat similar to that used in “self-starting ” vapour lamps, is shown in fig. 1. A strong arc is started between mercury pools K and A in the lower part of the vacuous tube; the third electrode B being a thick iron wire cemented in with sealing wax. Connections are made as shown. The apparatus having been pumped out to a very low pressure, an arc is struck between A and K, B being connected to the supply through a rheostat. When the ionised vapour from the arc AK reaches B, the second arc BK starts, taking a current whose strength depends on the resistance R 2 . This current strength can be indefinitely diminished by increasing R 2 . The low power arc BK can only be maintained in the presence of the strong ionising arc AK. If the pressure in the tube is sufficiently low and the current in BK is of the order of 0·1 ampére, the second arc fills the tube with a characteristic faint luminosity. In this state the vapour is found to exhibit marked selective absorption.

THE REACTION OF ACTIVE NITROGEN WITH ETHANOL

1965 ◽  
Vol 43 (4) ◽  
pp. 935-939 ◽  
Author(s):  
P. A. Gartaganis
Keyword(s):  
Flow System ◽  
Methyl Radicals ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Active Nitrogen ◽  
Condensed Discharge ◽  
Preliminary Study ◽  
Fast Flow ◽  
Ethyl Radicals ◽  
Water Hydrogen

The reaction of active nitrogen with ethanol has been investigated in the range 300 to 593 °K using a modified condensed-discharge Wood–Bonhoeffer fast-flow system. The only condensable products found in appreciable amounts were hydrogen cyanide and water. Hydrogen was the main noncondensable product. A very small amount of acetaldehyde was also formed along with traces of ethane, ethylene, methane, acetonitrile, cyanogen, and probably carbon monoxide. The overall activation energy is 3.4 kcal/mole. It is postulated that the mechanism consists of the formation of two fragments NC2H5 and OH, from which the condensable products result as follows:[Formula: see text]A number of products found in trace quantities are produced by concomitant reactions of the hydrogen atoms with methyl radicals, and with ethanol as well as by disproportionation of ethyl radicals to produce ethane and ethylene. A preliminary study of the reaction of active nitrogen with isopropanol indicated that the energy of activation is in line with the energies of activation of methanol and ethanol.

scholarly journals Investigations on the spectrum of selenium. III.—Extension of Se III

1934 ◽  
Vol 145 (855) ◽  
pp. 681-694 ◽  
Keyword(s):  
Capillary Tube ◽  
Infra Red ◽  
Condensed Discharge ◽  
Constant Deviation

In the second of these contributions dealing with investigations on the successive spectra of selenium, evidence was obtained that the spectrum of Se III consists of singlets and triplets, and nearly all the terms corresponding to the deepest 4 p and the higher 5 s , 4 d , 5 p and s p 3 states were discovered, The present work is an extension of the identification of the predicted terms, particularly those arising from the still higher states 6 s and 5 d ; it also gives the results of a further investigation of the spectrum in the infra-red region. It was pointed out in part II that many of the lines due to the transition 4 d → 5 p must be situated in the infra-red above λ 6700, and that their wave-lengths could be exactly calculated from the known values of the terms. the spectrum in this region has accordingly been investigated with a Hilger Constant Deviation spectrograph. the source employed was the usual condensed discharge through a capillary tube excited by a ½ K. W. transformer. To photograph this region, krypto- and neo-cyanine plates were used, after hypersensitizing them in a bath of ammonia. Exposures extended over a period of 8 to 10 hours. The lines of the iron are served as standards for the measurements of the plates. measurement of tire plates.

scholarly journals The hyperfine structure of Tl II

1931 ◽  
Vol 132 (819) ◽  
pp. 10-21 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Structure Analysis ◽  
Copper Wire ◽  
Wave Length ◽  
Slight Modification ◽  
Electrodeless Discharge ◽  
Spark Gap ◽  
In Series ◽  
Condensed Discharge ◽  
Term Analysis

In a previous publication a term and a hyperfine structure analysis of the spark spectrum of thallium, Tl II, were presented. The hyperfine structure analysis, although limited by the low resolution of the spectrographs employed, confirmed the intensity rules and the vector relation for the compounding of I and J; showed for the electronic configurations involving a 6 s electron that the energy of interaction between I and J was large; and established I = ½ for thallium. In view of the recent development of the theory of hyperfine structure, more accurate detail is desirable for the verification and the extension of this theory. The consistent interpretation of the preliminary hyperfine structure analysis, the completeness of the term analysis, the magnitude of the hyperfine separations, and the simplicity of the patterns, features of Tl II, suggested that for this spectrum a detailed hyperfine structure analysis, sufficiently accurate to confirm or show the limitations of the theory, would be feasible. Accordingly, the hyperfine structure of Tl II was investigated. The details and results of this investigation are presented below. The spectrum of thallium was excited by two methods: In the first, a condensed discharge was produced in thallium vapour, contained in a quartz discharge tube, by connecting the two terminals, sealed into the tube, in parallel with a condenser, and in series with an adjustable spark gap and the secondary of a transformer; in the second method, an electrodeless discharge was produced in the vapour by passing a high frequency current, generated in an oscillating circuit by a transformer with its secondary in series with a capacity and in parallel with a spark gap, through a heavy copper wire coiled around the tube containing the vapour. Both methods gave satisfactory excitation, but as the electrodeless method was more easily controlled it only was used in the latter part of the investigation. The radiation, excited by these methods was photographed in the spectral region λλ 7100-2300 A. U. in several orders, from the first to the fourth depending on wave-length, of a 3 metre concave grating of 60,000 lines, ruled with 15,000 lines to the inch. From the spectrograms obtained, the separations and the relative intensities of the hyperfine structure components were determined for the lines of appreci­able intensity in the analysis of Tl II, as presented by McLennan, McLay and Crawford and extended by Smith; and for a few additional lines classified in this investigation, the classification of which involved a slight modification and extension of the former term analysis.

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