arc spectrum

arc spectrum

[′ärk ‚spek·trəm]
(spectroscopy)
The spectrum of a neutral atom, as opposed to that of a molecule or an ion; it is usually produced by vaporizing the substance in an electric arc; designated by the roman numeral I following the symbol for the element, for example, HeI.
References in periodicals archive ?
On the Absorption Spectrum of Noble Gases at the Arc Spectrum Limit
It is experimentally known that arc spectrum series of noble gases do not converge toward a single limit, but toward two distinct limits.
b] spectra upon continuum terms of ordinary arc spectra gives rise to the same situation that occurs in noble gases' spectra between the two limits of the arc spectrum.