Observation of heterodyne mixing in surface x-ray photon correlation spectroscopy experiments.
We report measurements of propagating capillary waves on a liquid water surface at T=5 degrees C with x-ray photon correlation spectroscopy. The experiment has been performed under grazing incidence conditions with an incoming x-ray beam below the critical angle of total external reflection. In the q region investigated the measured intensity-intensity autocorrelation functions of the liquid water surface were found to be heterodyne signals, i.e., a combination of first- and second-order correlation functions g(1)(tau) and g(2)(tau).
Gutt
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C
Experimentelle Physik I, Universität Dortmund, Dortmund, Germany. gutt@physik.uni-dortmund.de
Ghaderi
T
T
Chamard
V
V
Madsen
A
A
Seydel
T
T
Tolan
M
M
Sprung
M
M
Grübel
G
G
Sinha
S K
SK