EXCITATION TEMPERATURE MEASUREMENTS IN GLOW AND ARC DISCHARGES IN HYDROGEN

Journal Article · Thu Jan 01 04:00:00 EST 1959 · Proc. Roy. Soc. (London)

DOI:https://doi.org/10.1098/rspa.1959.0018· OSTI ID:4258354

Edels, H; Gambling, W A

Experiments on high-pressure glow discharges in hydrogen have shown that by either increasing the current or gas pressure of the discharge, a sudden marked column constriction can be produced which results in the formation of an arc column. It was also found that this columnar glow-to-arc transition could be induced or reversed by control of the thermal conditions of the discharge, indicating that the transition depends upon the discharge temperature values. The relative intensities of the alpha , beta , and gamma Balmer lines emitted by the discharge column section in hydrogen were measured, and the variation of the excitation temperatures T/sub alpha beta / and T/sub beta gamma / through the discharge transition region was derived. The radiation measurements were made using a photomultiplier technique and yielded derived temperature values accurate to plus or minus 3%. Temperatures were obtained for currents between 0.25 and 10 A and for pressures from 0.33 to 2 atm. In all cases, except at 2 atm, the current range included the transition condition. The results show that with current variation the excitation temperature curves always exhibit minima at the transition current, even though the latter is changed by the change in pressure conditions. Further, the values of the minima are constant at 3900 plus or minus 100 deg K for T/sub alpha beta / and 2800 plus or minus 100 deg K for T/sub beta gamma /. A thermally dependent mechanism of arc column formation in hydrogen is indicated. The results also show that when the column is in the glow state T/sub alpha beta / > T/sub beta gamma /. It is concluded that in the glow state the distribution of excited state concentrations is nonthermal, being mainly governed by electron coillsions. Above the transition current value the results show that the excitation temperatures rapidly converge, so that for the arc a thermal distribution of concentrations exists in the quantum states n = 3, 4, and 5. However, from considerations of the derived values of electron concentration and electron drift velocity and from calculations of the excess of the electron temperature over the gas temperature, true thermal equilibrium does not exist in the newly formed low-current arc column in hydrogen. The transition in the column from glow to arc is explained in terms of the change in effective thermal conductivity produced by the variations of dissociation with temperature. (auth)

• Research Organization: Univ. of Liverpool
• Sponsoring Organization: USDOE
• NSA Number: NSA-13-004878
• OSTI ID: 4258354
• Journal Information: Proc. Roy. Soc. (London), Journal Name: Proc. Roy. Soc. (London) Vol. Vol: A249
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACTIVATION
CAPTURE
COBALT 59
COBALT 60
CROSS SECTIONS
CURRENTS
DISTRIBUTION
ELECTRIC ARCS
ELECTRIC DISCHARGES
ELECTRONS
EMISSION
ENERGY LEVELS
ENERGY RANGE
ERRORS
EV RANGE
EXCITATION
GASES
GLOW DISCHARGES
HALF- LIFE
HEAVY WATER
HYDROGEN
INTERACTIONS
IONIZATION
IRRADIATION
MEASURED VALUES
METALS
METASTABLE STATES
NUMERICALS
PHOTOMULTIPLIERS
PHYSICS AND MATHEMATICS
PLATES
PRESSURE
QUANTUM MECHANICS
REACTORS
SPECTRA
TEMPERATURE
THERMAL CONDUCTIVITY
THERMAL NEUTRONS
VARIATIONS
VELOCITY