Laser-produced continua for absorption spectroscopy in the VUV and XUV

Abstract

Recent work has shown that with appropriate targets, laser-produced plasmas provide clean essentially line-free continua suitable for absorption spectroscopy from 40 to 2000 Å. A systematic study of the continua emitted by the elements from samarium to ytterbium is reported, and their use in absorption spectroscopy is demonstrated. The temporal profiles of the continuum pulses at different wavelengths are studied with a photomultiplier system and are found to have essentially the same halfwidths as the pulse from the exciting Q-switched ruby laser (∼25 nsec). Pulse heights are shown to be reproducible to 15% or better. Ambient gases, at least at pressures up to several Torr, do not affect the emission mechanism. A comparison with other continuum sources at XUV wavelengths (i.e., BRV, synchrotron) is made, and possible future developments are outlined.