nmTransmission NEXAFS

Saturation free and time resolved soft X-ray absorption on liquids and colloids for UE52-SGM

This instrument is dedicated to time-resolved and steady-state soft x-ray absorption spectroscopy (XAS/NEXAFS/XANES/EXAFS) in transmission on liquid samples and solids. The liquid sample is continuously refreshed in a flatjet system. The transmitted intensity of synchrotron radiation for ground state NEXAFS is measured with a gallium arsenide photodiode (average diode current is recorded). For static measurements, the full filling pattern of BESSY II is used. For time-resolved measurements, a MHz laser excites the sample and an avalanche photo diode detects the time-dependent signal.

Selected Applications:
  • Photo-induced ligand substitution
  • Proton transfer - systematic investigations
  • Electronic structure changes upon UV excitation
  • Detection of excited states by photoabsorption
(a) Schematic top view of the experimental layout for static and time resolved NEXAFS measurements of liquid samples. (b) Thickness variation across a water flatjet based on the transmitted intensity

(a) Schematic top view of the experimental layout for static and time resolved NEXAFS measurements of liquid samples. (b) Thickness variation across a water flatjet based on the transmitted intensity


Methods

EXAFS, Time-resolved absorption, NEXAFS

Remote access

depends on experiment - please discuss with Instrument Scientist

Beamline data
Energy range 100 - 1500 eV
Energy resolution > 4,000
Flux > 1012
Polarisation variable
Focus size (hor. x vert.) 60 µm (hor)
Phone +49 30 8062 13431
More details UE52_SGM
Station data
Temperature range room temperature
Pressure range <10-3 mbar
Detector gallium arsenide photo (GaAsP) diode or avalanche photo diode (APD)
Manipulators X, Y, Z and rotation stage available
Sample holder compatibility -
Additional equipment MHz laser for time-resolved measurements:
• Power – 30 W
• Rep. rate – tunable from 2 MHz down to KHz
• Pulse duration – from 300 fs to 10 ps
• Wavelenght – 1030 nm, 515 nm, 343 nm and 258 nm
Samples Thin liquid films

End station for time-resolved and steady-state soft x-ray absorption spectroscopy (XAS/NEXAFS/XANES/EXAFS) in transmission on liquid samples. The liquid sample is continiously refreshed in a flatjet system. The transmitted intensity of synchrotron radiation for ground state NEXAFS is measured with a gallium arsenide (GaAs) photodiode. Here, the average diode current is recorded as a measure of transmitted intensity. For static measurements the full filling pattern of BESSY II is used. For time resolved measurement a MHz laser is incoupled to the end station. For time resolved studies an avalanche photo diode (APD) is used to separate the "single bunch" in the hybrid filling pattern of BESSY II. 

For details see: M. Fondell, S. Eckert, R. M. Jay, C. Weniger, W. Quevedo, J. Niskanen, B. Kennedy, F. Sorgenfrei, D. Shick, E. Giangrisostomi, R. Ovsyannikov, K. Adamzyk, N. Huse, P. Wernet, R. Mitzner, A. Föhlisch, "Time-resolved soft X-ray absorption spectroscopy in transmission mode on liquids at MHz repetition rates", Structural dynamics 4, 054902 (2017).