Optical Spectra from Fast Ion Beams.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Optical Spectra from Fast Ion Beams. Meinel, A. B. ; Bashkin, S. Abstract Bashkin and Meinel have explored the method proposed by Bashkin to use a van de Graaff accelerator as a source of optical electronic transitions in ionic species. The production of excited states is by stripping a fast beam of ions by means of a carbon foil of a few micrograms per square mm thickness. The foil strips the ion of additional electrons and produces, with a high probability, an ion with residual electronic excitation. Upon decay of these states an emission spectrum is produced. The spectrum, moreover, shows a decay of intensity with distance downstream from the foil that is in general different for each emission wavelength. This fact offers in principle a means for directly observing the lifetimes of excited electronic states in atoms and under certain conditions the measurement of absolute oscillator strengths. Our first experiments with C, N, and 0 species at energies of the order of 1 MeV yielded an emission spectrum that showed a remarkable similarity in the line intensities to the spectra of novae, encouraging us to feel that we have a new laboratory tool of considerable precision to investigate properties of spectra of importance in some types of astronomical objects. A van de Graaff accelerator has recently been added to the facilities of the Department of Physics in Tucson, where experimental studies are being continued. The assistance of the staff of the Naval Research Laboratory and the use of their 5 MV van de Graaff accelerator is acknowledged in this work. Publication: The Astronomical Journal Pub Date: October 1964 DOI: 10.1086/109496 Bibcode: 1964AJ.....69S.552M full text sources ADS |