Measurements of the vapor pressure of cesium by absorption of resonance radiation, λ = 8521 Å

Abstract

We have measured using optical means the absolute density of the saturated vapor pressure of cesium by absorption of resonance radiation corresponding to the 62P3/2→62S1/2 transition. Experimental results are compared with those obtained with a surface-ionization gauge and with the Taylor-Langmuir equations. Density was measured between 12.5°C and 39.2°C; in this temperature range the experimental error is about 10%. For higher temperatures, the absorption increases with the temperature but is not in a simple fashion related to the atom density in the absorption cell. A different method is proposed which permits density to be measured up to temperatures above 100°C, but this requires calibration using the Taylor-Langmuir formulae.