Interferometric Wavelengths of Iron Lines from a Hollow Cathode Discharge*

Abstract

Interferometric wavelength measurements (3570 A to 5709 A) are given for 189 iron lines produced by a hollow cathode discharge. The lines are considerably sharper than those of the iron arc and the available evidence shows that the wavelengths are invariant with any changes in operating conditions of the tube. The hollow cathode discharge tube in neon with iron electrodes appears to be the best source of standards for wavelength measurements.