| Paper |
Title |
Other Keywords |
Page |
| PM08 |
Recent Advances in the Measurement of Chromaticity Via Head-Tail Phase Shift Analysis
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diagnostics, instrumentation, chromatic effects, LHC |
107 |
| |
- N. Catalan-Lasheras, S. Fartoukh, R. Jones
CERN, Geneva, Switzerland
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A so-called "Head-Tail" monitor has been operational in the CERN-SPS for
a few years. The measurement of chromaticity using such a monitor relies
on the periodic dephasing and rephasing that occurs between the head and
tail of a single bunch for non-zero chromaticity. By measuring the
turn-by-turn position data from two longitudinal positions in a bunch it
is possible to extract the relative dephasing of the head and the tail,
and so to determine the chromaticity. Until recently this technique had
suffered from an unexplained “missing factor” when compared to
conventional chromaticity measurements. This paper explains the source of
this factor and also reports on the considerable experimental, simulation
and analysis effort that has qualified the technique for use in the LHC.
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| PM11 |
Beam Studies Made With The SPS Ionization Profile Monitor
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diagnostics, emittance, instrumentation, monitoring |
116 |
| |
- C. Fischer, G. Ferioli, J. Koopman, F. Roncarolo
CERN, Geneva, Switzerland
| |
During the last two years of SPS operation, investigations were pursued
on the ability of the SPS ionization profile monitor prototype to fulfill
different tasks. It is now established that the instrument can be used
for injection matching tuning, by turn to turn recording of the beam size
after the injection. Other applications concern beam size measurements on
beams ranging from an individual bunch to a nominal SPS batch foreseen
for injection into the LHC (288 bunches). By continuously tracking
throughout the SPS acceleration cycle from 26 GeV to 450 GeV the
evolution of parameters associated to the beam size, it is possible to
explain certain beam behavior. Comparisons are also made at different
beam currents and monitor gains with measurements made with the wire
scanners. Data are presented and discussed, and the possible
implementation of new features is suggested in order to further improve
the consistency of the measurements.
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| PT27 |
A 40 MHz Bunch by Bunch Intensity Measurement for the CERN SPS and LHC
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diagnostics, instrumentation, LHC |
237 |
| |
- H. Jakob, L. Jensen, R. Jones, J.J. Savioz
CERN, Geneva, Switzerland
| |
A new acquisition system has been developed to allow the measurement of
the individual intensity of each bunch in a 40 MHz bunch train. Such a
system will be used for the measurement of LHC type beams after
extraction from the CERN-PS right through to the dump lines of the
CERN-LHC. The method is based on integrating the analogue signal supplied
by a Fast Beam Current Transformer at a frequency of 40 MHz. This has been
made possible with the use of a fast integration ASIC developed by the
University of Clermont-Ferrand, France, for the LHC-b pre-shower
detector. The output of the integrator is digitised using a 12-bit ADC
and fed into a Digital Acquisition Board (DAB) that was originally
developed by TRIUMF, Canada, for use in the LHC orbit system. A full
system set-up was commissioned during 2002 in the CERN-SPS, and following
its success will now be extended in 2003 to cover the PS to SPS transfer
lines and the new TT40 LHC extraction channel.
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