Ultra-small-angle X-ray photon correlation spectroscopy using the Eiger detector

Successful implementation of the single-photon-counting Eiger 500k pixel array detector for sub-millisecond X-ray photon correlation spectroscopy (XPCS) measurements in the ultra-small-angle scattering region is reported. The performance is demonstrated by measuring the dynamics of dilute silica colloids in aqueous solvents when the detector is operated at different counter depths, 4, 8 and 12   bit. In the fastest mode involving 4   bit parallel readout, a stable frame rate of 22   kHz is obtained that enabled measurement of intensity – intensity autocorrelation functions with good statistics down to the 50   µ s range for a sample with sufficient scattering power. The high frame rate and spatial resolution together with large number of pixels of the detector facilitate the investigation of sub-millisecond dynamics over a broad length scale by multispeckle XPCS. This is illustrated by an example involving phoretic motion of colloids during the phase separation of the solvent.

Source: Journal of Synchrotron Radiation - October 24, 2018 Category: Physics Authors: Zinn, T. Homs, A. Sharpnack, L. Tinti, G. Fr ö jdh, E. Douissard, P.-A. Kocsis, M. M ö ller, J. Chushkin, Y. Narayanan, T. Tags: USAXS XPCS colloid dynamics coherent X-ray scattering research papers Source Type: research