| Paper |
Title |
Other Keywords |
Page |
| CT08 |
Adaptive Optics for the LEP 2 Synchrotron Light Monitors
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synchrotron, extraction, radiation, optics |
77 |
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- G. Burtin, R.J. Colchester, G. Ferioli, J.J. Gras, R. Jung, J.M. Vouillot
CERN, Geneva, Switzerland
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The image obtained with the LEP synchrotron
radiation telescopes deteriorates, giving multiple and
deformed images, when the beam energy goes beyond
80 GeV at beam currents above 2 mA. This problem is
due to the deformation of the light extracting beryllium
mirror, by as little as 1 mm, and had been predicted at
the design stage. To overcome this problem, several
changes together with an adaptive optics set-up have
been introduced. These essentially consist of a
cylindrically deformable mirror to compensate the
cylindrical deformation of the beryllium mirror and a
movable detector to compensate the spherical
deformation. Both components are continuously
adjusted as a function of beam current and energy.
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| PT16 |
Status of the delta synchrotron light-monitoring-system
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synchrotron, radiation, shielding, emittance |
196 |
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- U. Berges, K. Wille
DELTA, Institute for Accelerator Physics and Synchrotron Radiation, University of Dortmund, Germany
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A synchrotron radiation source like DELTA needs an optical
monitoring system to measure the beam size at different
points of the ring with high resolution and accuracy.
The measurements with the present synchrotron light
monitors show that beam sizes larger than 250 μm can be
measured. The measured emittance is of the order of the
theoretical values of the optics and goes down to 8 nm rad.
The magnification of the system can simply be increased
by adding another lens to measure smaller emittances and
beamsizes down to 100 μm. In this case you still have
an optical image of the beam available, but sometimes the
position of the camera has to be adapted due to the great
magnification of the optical system. The image processing
system which is based on a VME Framegrabber makes a
two dimensional gaussian fit to the images from different
synchrotron light-monitors.
First tests with monochromatic components of the synchrotron
radiation (500 nm and 550 nm) and with short
time cameras (shutter time down to 1/10000 s) have been
performed. A two-dimensional PSD has been installed to
measure slow beam motion. To measure small beam sizes,
especially in the vertical plane, diffraction elements will be
used.
This paper gives an overview over the present installation
and the results.
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