Extreme Ultraviolet Absorption by Lithium Fluoride

Abstract

A study was made to determine the absolute value of the absorption coefficient for lithium fluoride between 10 and 110 ev. The first exciton level in the fundamental absorption was found to be at 12.9 ev. Absorption structure attributed to the fluorine $2s$ electrons and lithium $1s$ electrons was observed. The energy band gap was estimated to be less than 14 ev. The absorption structure associated with the Li $K$ electrons was found at energies corresponding to transitions by the $2s$ electrons of the free ${\mathrm{Li}}^{+}$ ion. A duplication of this structure at a higher energy suggested the possibility that a multiple process was involved in the photon absorption.