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An extended and revised analysis of the spectrum of Be(III) is reported. Spectra of Be were recorded at the Joint European Torus (JET) fusion facility where beryllium was used as surface material in the divertor in 1995. Observations of the divertor plasma have revealed many previously unknown Be lines, of which 28 (in the range 2100 angstroms to 5300 angstroms) have been classified as Be(III) transitions. Passive charge exchange processes between neutral excited hydrogen (n=2) and ground state Be(3+) leading to enhanced population of Be(2+) (n=5) is evident. Observed line components belonging to the 4-5 transition array lying in the visible or near visible wavelength region are with the exception of 4f-5g completely resolved into triplet and singlet branches. These data, together with 32 previously known lines now represent an observed term system comprising 40 levels, with energy value uncertainties of around +/- 1 cm{-1}. The ionization energy of 1 s{2} has been determined to 1 241 243 +/- 13 cm{-1} with an estimated Lamb shift of -43 +/- 13 cm{-1}. A complete description of the term scheme deduced from polarization and Ritz formulae is presented.

Additional information

Authors: JUPÉN C, University of Lund, Department of Physics (SE);BERINGER M, JET Joint Undertaking, Abingdon, Oxon (GB);MEIGS A, JET Joint Undertaking, Abingdon, Oxon (GB);VON HELLERMANN M, JET Joint Undertaking, Abingdon, Oxon (GB);MORSI H W, CEC Bruxelles (BE);JUPEN C, University of Lund, Department of Physics (SE)
Bibliographic Reference: Report: JET-P(96)52 EN (1996) 26pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (GB)
Record Number: 199710051 / Last updated on: 1997-02-26
Original language: en
Available languages: en