A. Müller (1), S. Schippers (1), R. A. Phaneuf (2), A. L. D. Kilcoyne (3),
H. Bräuning (1), A. S. Schlachter (3), M. Lu. (2), and B. M. McLaughlin (4,5) ((1)Institut für Atom- und Molekülphysik, Justus-Liebig-Universität Giessen,Giessen, Germany; (2) Department of Physics, University of Nevada, Reno, NV, USA; (3) Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; (4) School of Mathematics and Physics, The David Bates Building, Queen’s University Belfast, Belfast, UK; (5) Institute for Theoretical Atomic and Molecular Physics, Harvard Smithsonian
Center for Astrophysics, Cambridge, MA, USA)
High-resolution photoionization experiments were carried out using beams of Be-like C^{2+}, N^{3+}, and O^{4+} ions with roughly equal populations of the ^1S ground-state and the ^3P^o manifold of metastable components. The energy scales of the experiments are calibrated with uncertainties of 1 to 10 meV depending on photon energy. Resolving powers beyond 20,000 were reached allowing for the separation of contributions from the individual metastable ^3P_0^0, ^3P_1^o, and ^3P_2^o states. The measured data compare favourably with semi-relativistic Breit-Pauli R-matrix.
Complete preprint ==> http://arxiv.org/abs/1203.6533