Giant Resonances in Atoms and in Fluorine Cage Molecules

Abstract

Giant resonances in the photoabsorption spectra of atoms occur in the extreme ultraviolet region of the electromagnetic spectrum. In order to observe absorption spectra in this region it is necessary to generate columns of atomic vapour which will often be very hot and chemically aggressive, and to contain them without solid windows between two regions of high vacuum, the spectrometer and the light source, usually an electron synchrotron. The technical problems are often formidable so that although it had long been recognised that giant resonances in solid lanthanides were essentially atomic phenomena (Fomichev et al. 1967, Dehmer et al. 1971) earlier investigations of giant resonances in atoms were limited to the more managable elements which precede the transition rows, the inert gases, alkali and alkaline earth elements.