The profile of the Fe 372·00 nm line excited in a hollow cathode discharge

The profile of the Fe 372·00 nm line emitted in the negative glow of a hollow-cathode discharge is analyzed. The value of the discharge current was varied within the range 7–15 mA, the neon pressure being 1·22–4·40 Torr. The Lorenzian and Gaussian components of the recorded line profile were corrected for instrumental broadening. A correlation was found to exist between the Gaussian component and the cathode voltage drop. The half-width of the Lorentzian component shows the expected dependence on gas pressure. Under the operating conditions used, this component is approx. 10² times greater than the natural one. No dependence on the discharge current was observed. The emitted line profiles may be considered to be Voigt functions with the Voigt parameter varying in the range 3·2 × 10^-2 to 5.5 × 10^-2