Paper |
Title |
Other Keywords |
Page |
PS02 |
Chromaticity Measurements at HERA-P Using the Head-Tail Technique with Chirp Excitation
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betatron, synchrotron, proton, pick-up |
103 |
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- M. Wendt, F. Willeke
DESY, Deutsches Elektronen-Synchrotron, Hamburg, Germany
- A. Boudsko
TRIUMF, Vancouver, Canada
- O.R. Jones, H. Schmickler
CERN, Geneva, Switzerland
|
Experiments have been performed in the HERA proton ring
(HERA-p) to test a quasi non-destructive method of chromaticity
measurements for protons. The method is based
on the detection of the head-tail phase shift of coherend betatron
oscillations using a broadband beam position pickup
and a commercial fast-frame oscilloscope. Previous experiments
have relied on a single kick for transverse excitation,
whereas the results presented here were carried out
using swept frequency chirp excitation. The tests proved
to be successful, and the method seems to be a good candidate
for chromaticity measurement in new large hadron
accelerators, such as LHC.
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PS15 |
Beam profile measurements at 40 MHz in the PS to SPS transfer channel
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injection, proton, ion, radiation |
135 |
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- G. Ferioli, J.J. Gras, H. Hiller, R. Jung
CERN, Geneva, Switzerland
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Bunch to bunch beam profile measurements provide a
valuable tool to control the injection lines to the SPS.
A fast profile monitor based on a 2.5μm Mylar coated
with Aluminium Optical Transition Radiation (OTR)
radiator, has been developed, installed and tested in the
transfer line between the PS and SPS.
The OTR beam image is focused onto a fast Linear
Multianode Photo Multiplier Tube and the associated
electronics sample and store profiles every 25ns.
The paper describes the detector design, the electronic
processing, and presents the results of different
measurements made with bunches of 109-1011 protons at 26
GeV, and bunches of 106 Pb82+ ions at 5.11 GeV/u.
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PS16 |
The fast head-tail instability suppression in multibunch mode at VEPP-4M
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feedback, injection, dipole, impedance |
138 |
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PT11 |
Dipole modes study by means of HOM couplers at SBTF
|
dipole, coupling, pick-up, damping |
183 |
|
- N. Baboi, M. Dohlus, A. Jöstingmeier, N. Holtkamp, M. Wendt, M. Nagl, J. Boster, H. Hartwig
DESY, Deutsches Elektronen Synchrotron, Hamburg, Germany
|
High order modes (HOM) are generated by the interaction
of a bunched beam with an accelerator environment. They
may act destructively on following particle bunches, leading
to an increase of the transverse oscillation amplitude
and finally to the deterioration of the emittance. Dipole
modes have been studied at the S-Band Test Facility at
DESY. One accelerating structure, specially designed for
this test linac, is equipped with waveguide pick-ups for
measuring the HOMs. For one part of the experiments, a
modulation of the transverse offset of the bunches at the
structure entrance has been induced using a fast broadband
kicker and the effect was measured with a precise stripline
BPM. No high impedance modes were clearly found in the
structure, which has been detuned and damped by both the
tapered geometry of the structure and an absorbing stainless
steel coating applied on the iris tips.
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PT15 |
High current precision long pulse electron beam position monitor
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electron, instrumentation, diagnostics, target |
193 |
|
- S.D. Nelson, Y.J. Chen, T. Fessenden, C. Holmes
LLNL, Lawrence Livermore National Laboratory, Livermore, CA, USA
|
Precision high current long pulse electron beam position
monitoring has typically experienced problems with high
Q sensors, sensors damped to the point of lack of precision,
or sensors that interact substantially with any beam
halo thus obscuring the desired signal. As part of the
effort to develop a multi-axis electron beam transport system
using transverse electromagnetic stripline kicker technology,
it is necessary to precisely determine the
position and extent of long high energy beams for accurate
beam position control (6 - 40 MeV, 1 - 4 kA, 2 μs
beam pulse, sub millimeter beam position accuracy.)
The kicker positioning system utilizes shot-to-shot adjustments
for reduction of relatively slow (< 20 MHz) motion
of the beam centroid. The electron beams passing through
the diagnostic systems have the potential for large halo
effects that tend to corrupt position measurements.
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