High-resolution angular beam stability monitoring at a nanofocusing beamline.
Two semi-transparent imaging beam-position monitors developed at the ESRF have been installed at the micro-analysis beamline ID22 for monitoring the angular stability of the X-ray beam. This system allows low-frequency (10 Hz) angular beam stability measurements at a submicroradian range. It is demonstrated that the incoming macro-beam angular fluctuations are one of the major sources of focal spot instabilities downstream of the Kirkpatrick-Baez mirrors. It is also shown that scanning the energy by rotating the so-called fixed-exit monochromator induces some unexpected angular beam shifts that are, to a large extent, deterministic.
Tucoulou
R
R
ESRF, 38043 Grenoble CEDEX 09, France. tucoulou@esrf.fr
Martinez-Criado
G
G
Bleuet
P
P
Kieffer
I
I
Cloetens
P
P
Labouré
S
S
Martin
T
T
Guilloud
C
C
Susini
Jean
J