MEASUREMENT OF NITROGEN II AND CARBON II RESONANCE MULTIPLET LINE SHAPES FROM A PLASMA.

The spectral line shapes of the Nitrogen II and Carbon II resonance multiplets, which occur in the vacuum ultraviolet region of the spectrum, have been measured. The Stark widths were deduced from the optically thin Lorentz wings. The source of radiation was a hot plasma produced by reflecting the shock wave generated by an electromagnetic T-type shock tube operating at a moderate pressure of helium gas to which the test elements and hydrogen were added. The electron temperature was determined from the ratio of the total intensities of the He I 4713 A and the H beta 4861 A lines. The electron density was obtained from the halfwidth of the He I 3889 A line. Measurement of the electron temperature and density of the test plasma was such as to provide a critical test of a recent semiempirical theory of Stark broadening of isolated ion lines under conditions in which the broadening electron collisions are predominantly elastic and without classical analogue. Agreement with the theory was found to within the expected precision of the theory. Author