Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 17: Posters Friday (Spectroscopy)
A 17.49: Poster
Freitag, 6. April 2001, 12:30–15:00, AT3
Forbidden-line lifetime measurements in Fe X through Fe XIII — •Elmar TRÄBERT1,2, Gerald GWINNER3, Emile J. KNYSTAUTAS4, Xavier TORDOIR2, and Andreas WOLF3 — 1Ruhr-Universität Bochum, GERMANY — 2Université de Liege, IPNAS B15, Belgium — 3Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany — 4Département de physique, Université Laval, Québec, Québec, Canada G1K 7P4
Electric-dipole forbidden transitions in highly charged heavy ions of the iron group are among the most prominent lines in the visible and ultraviolet spectrum of the solar corona. Under quiet corona conditions, Fe X (the spectrum of the ion Fe9+ and neighbouring spectra are expected to be brightest. However, while the levels of the 3s23pk ground configurations in most iron ions are well established, many of the high-J levels of the 3s23pk−13d configurations are not, and calculations are sparse.
We have used the Heidelberg heavy-ion storage ring TSR for lifetime measurements on 3p and 3d levels in Fe9+ through Fe12+. Our optical observations in the wavelength range 160 nm - 310 nm yielded lifetimes in the 4 ms - 310 ms range, some of which reached uncertainties as low as 1%. This precision exceeds that of all available predictions of these lifetimes.