Berkeley Lab

Facilities

The Chemical Dynamics Project employs a variety of femtosecond and picosecond XUV and X-ray light sources to study electronic and structural dynamics in molecules, clusters, and interfacial systems. Laboratory-based experiments using high-order harmonics generation (HHG) driven light sources are complemented by experimental campaigns at X-ray free electron lasers (X-FELs) and synchrotron radiation light sources.

HHG based experiments

All laboratory based experiments of the Chemical Dynamics Project are driven by a high-power, high-repetition rate femtosecond laser system operating at a central wavelength of 780 nm that runs at repetition rate of 1-3 kHz with up to 12-15 W average power output (≤12 mJ at 1 kHz, ≤5 mJ at 3 kHz), and a pulse duration of ≈25 fs. This laser drives three high-order harmonic generation light sources consisting of gas cells filled with noble gases at pressures of several to several 10 mbar. The emerging femtosecond XUV and X-ray pulses are used to either access highly excited states of noble gas clusters or probe ultrafast molecular dynamics by time-resolved inner-shell absorption spectroscopy.

Figure A1: Schematic of the femtosecond XUV photoelectron and ion imaging experiment that is used to study ultrafast dynamics in superfluid helium nanodroplets.

HeDropletSetup

 

Figure A2. Components of the Chemical Dynamics experimental setup:

Figure A2

a) High repetition rate, high power femtosecond laser system

 

Figure A2 b)

b) femtosecond HHG beamline

 

IMG_5887

c) panorama of Chemical Dynamics Laboratory

X-FELs and Synchrotrons

Femtosecond and picosecond time-resolved X-ray spectroscopy and coherent diffractive imaging experiments are currently performed at the Linac Coherent Light Source (LCLS) X-ray free electron laser (X-FEL) at SLAC National Accelerator Laboratory and the Advanced Light Source (ALS) synchrotron radiation facility at Berkeley Lab.