Determination of the vapor pressure of rubidium by optical absorption

The vapor pressure of rubidium was determined in the neighborhood of 330 K from measurements of optical absorption of the resonance lines. A narrow-line source was used and a full analysis of the line profiles was done. Measurements of resonance-broadening depolarization give another check on the Rb vapor pressure in the 430-K range, assuming that theoretical cross section is correct. The results are very close to the analytic compromise previously suggested by Nesemeyanov.