Exploring few-photon, few-electron reactions at FLASH: from ion yield and momentum measurements to time-resolved and kinematically complete experiments

A Rudenko (1) , y H Jiang (2) , M Kurka (2) , K U Kühnel (2) , L Foucar (1) , O Herrwerth (3) , M Lezius (3) , M F Kling (3) , C D Schröter (2) , R Moshammer (1, 2) , J Ullrich (1, 2)

1 Max Planck Advanced Study Group at CFEL
2 MPIK - Max-Planck-Institut für Kernphysik
3 MPQ - Max-Planck-Institut für Quantenoptik

In this contribution we briefly review a series of recent pioneering experiments on fewphoton-induced multiple fragmentation of atoms and molecules performed at the Free electron LASer at Hamburg (FLASH) using a " Reaction Microscope ", i.e., a coincident momentum imaging technique. For atoms we consider the most basic non-linear process, namely direct or sequential two-photon double ionization (TPDI). In particular benchmark data for theory are presented such as recoil-ion momentum distributions for direct TPDI of He and Ne, and fully differential data for sequential TPDI of Ne. For molecules we show how one can identify contributions from different reaction channels by inspecting the measured kinetic energy and angular distributions of ionic fragments, and even infer the time-delay between the two photon absorption events in TPDI by detailed comparison with theory. Finally, we describe a novel split mirror arrangement for EUV-pump – EUV-probe experiments, and present the very first time-resolved data on the dynamics of N 2 molecules irradiated by the FLASH light.

Mots clés: Physical Sciences

A Rudenko, y H Jiang, M Kurka, K U Kühnel, L Foucar, et al.. Exploring few-photon, few-electron reactions at FLASH: from ion yield and momentum measurements to time-resolved and kinematically complete experiments. Journal of Physics B: Atomic, Molecular and Optical Physics, 2010, 43 (19), pp.194004. ⟨10.1088/0953-4075/43/19/194004⟩. ⟨hal-00569836⟩