  Using radiometrically calibrated instrumentation of Physikalisch-Technische
Bundesanstalt, the L-shell fluorescence yields and Coster-Kronig factors of
tantalum (including the uncertainty budget) were experimentally determined
based on transmission and X-ray fluorescence experiments. The determined
fluorescence yields ($\omega_{L3} = 0.247(12)$, $\omega_{L2} = 0.278(15)$,
$\omega_{L1} = 0.157(12)$) were independently validated trough XRR-GIXRF
experiments. Both, the Coster-Kronig factors ($f_{23} = 0.123(84)$, $f_{13} =
0.328(152)$, $f_{12} = 0.14(11)$) as well as the fluorescence yields are in
good agreement with the most established databases in the field of X-ray
fluorescence.

Atomic Physics