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Title |
Page |
| PM19 |
Ionisation Beam Profile Monitor at the Cooler Synchrotron COSY-Jülich
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140 |
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- V. Kamerdzhiev, J. Dietrich
IKP, Forschungszentrum Jülich, Germany
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For beam profile measurements, a residual-gas ionisation beam profile
monitor using a position sensitive micro channel plate (MCP) detector was
developed and installed at the cooler synchrotron and storage ring
COSY at Forschungszentrum Julich.
A parallel ion drift field is maintained in the gap between two
electrodes. Residual gas ions are drifted onto an MCP assembly that
provides a charge gain of about 107. For online calibration the detector
can be illuminated with an α-source. The secondary charge produced from
each ion is collected by a wedge and strip anode. After some processing
the charge signal is digitized and read out by means of a PC running
Cobold PC software.
Since COSY operates with beam intensities up to 1011 protons and a vacuum
of 10-9 mbar, there is a high risk of detector damage. The lifetime of
the channel plates and the event rate are crucial issues for the profile
measurement of intense proton beams. The aging of the channel plates
(i.e. inhomogeneous decrease of the gain) were investigated using
scanning electron microscope and energy dispersive x-ray microanalysis.
Different implemented detector protection mechanisms are discussed.
Measurements with electron cooled beams are reported.
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| PT19 |
Transverse Feedback System For The Cooler Synchrotron COSY-Jülich - First Results
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214 |
| |
- V. Kamerdzhiev, J. Dietrich, I. Mohos
IKP, Forschungszentrum Jülich GmbH, Jülich, Germany
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The cooler synchrotron COSY delivers unpolarized and polarized protons
and deuterons in the momentum range 300 MeV/c up to 3.65 GeV/c. Electron
cooling at injection level and stochastic cooling covering the range from
1.5 GeV/c up to maximum momentum are available to prepare high precision
beams for internal as well as for external experiments in hadron physics.
In case of electron cooled beam the intensity is limited by transverse
instabilities. The major losses are due to the vertical coherent beam
oscillations. To damp these instabilities a transverse feedback system is
under construction. First results with a simple feedback system are
presented. Due to the feedback system operation the intensity and
lifetime of the electron cooled proton beam at injection energy could be
significantly increased. Measurements in frequency and time domain
illustrate the performance of the system.
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