Letter | Published:

Spectral Continua of the Rare Gases

Nature volume 142, page 614 (01 October 1938) | Download Citation



IT is known that most of the rare gases emit spectral continua under certain conditions of excitation. The most favourable conditions for excitation are obtained in the uniform positive column of an electric discharge using wide tubes, high pressures and low density currents. In the range of pressures, p, over which the continua predominate, the ratio of the axial force Z to the pressure p is small and decreases slowly with increase of pressure. As the pressure increases, the intensity of the continua emitted increases with respect to the intensity of the line spectra, and the intensity of the lines requiring the higher energies to excite them decreases rapidly with increase of pressure compared with that of the lines requiring the lower energies. For example, in argon and krypton at 40 mm. pressure, the only lines with intensities comparable with that of the continuum are those which emanate from the 2p levels requiring about 13 electron volts to excite them.

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  1. Electrical Laboratory, Oxford. Aug. 14.

    • S. P. MCCALLUM


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