Time-resolved spectroscopy of doubly-excited states in helium Christian Ott, Andreas Kaldun, Philipp Raith, Kristina Meyer, Martin Laux, Yizhu Zhang, Steffen Hagstotz, Thomas Ding, Robert Heck and Thomas Pfeifer EPJ Web of Conferences, 41 (2013) 02023 Published online: 13 March 2013 DOI: 10.1051/epjconf/20134102023