Fundamental Absorption in Alkali Chlorides in the Extreme Ultraviolet

Abstract

The absorption measurements were made on thin films of solid solutions of alkali chlorides at room temperature. The differences in the spectra of NaCl, KCl, and RbCl are discussed in connection with the nature of the alkali metals. From the measurements in KCl–NaCl and KCl–RbCl, additional evidences were obtained for the assignment of the peaks at 20.3 eV and 21.5 eV in KCl being due to the transitions from K⁺ 3p level. The peaks at 11.4 eV and at 12.3 eV in NaCl are proposed to be attributed to Na⁺ ion through the results obtained in KCl–NaCl system. These peaks in NaCl were found to behave consistently also in the system NaCl–NaBr.