Interferometric Measurement of Large Number Density of Metal Vapor in the Heat Pipe

Abstract

A method is proposed which permits one to determine a large number density of metal atoms along the absorption path in a heat-pipe cell. The proposed method requires a measurement of the anomalous dispersion near the absorption lines with known oscillator strengths by the use of a Mach-Zehnder interferometer and a stigmatic spectrograph. The method is tested on the resonance line of calcium and the first doublet of sodium. Its advantage over the hook method and the method by Frich et al. is demonstrated, and its precision and validity are discussed.