This ultra-high vacuum chamber was designed for studying
surface photochemistry, non-linear optical processes, and two-photon
photoemission. The resistively heated Pt(111) single crystal is held on a
(x, y, z, f) manipulator with an open loop liquid helium cooled cryostat. In
addition to photochemical work the chamber is equipped for x-ray
photoelectron spectroscopy, Auger electron spectroscopy, and thermal
programmed desorption spectroscopy.
Planned experiments include measuring ultrafast wavelength dependent
photochemical cross sections of small molecules such as N2, CO2 and CH4,
probing ultrafast surface dynamics, and examining unique photochemical
reactions driven by short-pulse light. Two-photon photoemission will be used
to probe the affinity bands of small molecules adsorbed on the Pt(111)
surface as a function of Cs or K promoter coverage. Sum frequency generation
studies are also planned, in order to optimize the technique with a minimal
number of experimental variables.
Surface characterization techniques include angle-resolved X-ray
photoelectron spectroscopy, Auger spectroscopy, and thermal programmed
desorption spectroscopy. A flowing liquid helium cryostat built into the
sample manipulator can cool samples to 20 K. Resistive heating provides the
means to raise a sample's temperature to as high as 1500 K. Current work
examines the ultrafast dynamics of adsorbates and electrons on Pt(111)
surfaces in studies of catalysis and fs-MALDI.