Dedicated to Bretislav Friedrich on the occasion of his 60 th birthdayWe demonstrate strong adiabatic laser alignment and mixed-field orientation at kHz repetition rates. We observe degrees of alignment as large as cos 2 θ 2D = 0.94 at 1 kHz operation for iodobenzene. The experimental setup consist of a kHz laser system simultaneously producing pulses of 30 fs (1.3 mJ) and 450 ps (9 mJ). A cold 1 K state-selected molecular beam is produced at the same rate by appropriate operation of an Even-Lavie valve. Quantum state selection has been obtained using an electrostatic deflector. A camera and data acquisition system records and analyzes the images on a single-shot basis. The system is capable of producing, controlling (translation and rotation) and analyzing cold molecular beams at kHz repetition rates and is, therefore, ideally suited for the recording of ultrafast dynamics in so-called "molecular movies".

This paper gives an account of our progress towards performing femtosecond time-resolved photoelectron diffraction on gas-phase molecules in a pump-probe setup combining optical lasers and an X-ray free-electron laser. We present results of two experiments aimed at measuring photoelectron angular distributions of laser-aligned 1-ethynyl-4-fluorobenzene (C(8)H(5)F) and dissociating, laser-aligned 1,4-dibromobenzene (C(6)H(4)Br(2)) molecules and discuss them in the larger context of photoelectron diffraction on gas-phase molecules. We also show how the strong nanosecond laser pulse used for adiabatically laser-aligning the molecules influences the measured electron and ion spectra and angular distributions, and discuss how this may affect the outcome of future time-resolved photoelectron diffraction experiments.