A&A Supplement series, Vol. 122, April I 1997, 1-10
Received May 13; accepted July 2, 1996
K.L. Mullman - M. Sakai - J.E. Lawler
Send offprint request: K.L. Mullman
Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, U.S.A.
We report the first laboratory measurement of absorption oscillator strengths (f-values) for 6 VUV () transitions of the multiplet (#8) in Fe II. We have also reconfirmed a recent measurement of the f-value of the Fe II resonance line at . These measurements are made with the high sensitivity absorption experiment at the University of Wisconsin-Madison. Measurements are also made on UV () lines in Fe II with accurately known f-values in order to construct a reliable curve of growth for the experiment. Diffusive cooling of ions in the negative glow of the hollow cathode discharge, which serves as an absorbing sample, results in a non-Maxwellian ion velocity distribution. A satisfactory curve of growth is generated using a full Voigt profile with an artificially low ion temperature in some cases.
keywords: atomic data -- ISM: abundances -- ISM: atoms -- ultraviolet: general -- Sun: abundances