| Paper |
Title |
Page |
| IT11 |
Possible Spin-Offs from LHC Physics Experiments for Beam Instrumentation
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51 |
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- R. Jones
CERN, Geneva, Switzerland
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This paper aims to introduce some of the new
technology and materials used in the construction of the
LHC physics experiments into the domain of the beam
instrumentalist. The development of radiation hard fibre-optic
technology, for example, can equally well be
applied to beam instrumentation systems for the direct
transmission of analogue or digital signals from high to
low radiation environments. Many electronics techniques
such as a system developed for the fast integration of
photomultiplier signals could also prove very useful in
the construction of new beam diagnostic instruments for
bunch-to-bunch measurements. Other topics covered will
include a fast beam synchronous timing system based on
laser technology and a look at pixel detectors as a
possible replacement for CCD cameras in imaging
applications.
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| CT06 |
The Measurement of Q' And Q'' in the CERN-SPS by Head-Tail Phase Shift Analysis
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79 |
| |
- R. Jones, H. Schmickler
CERN, Geneva, Switzerland
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A so-called "Head-Tail" chromaticity measurement system has recently
been installed in the CERN-SPS, which allows the chromaticity (Q’) to be
calculated from several hundred turns of data after transverse
excitation. The measurement 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 turnby-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. In addition, by changing the orbit of the circulating beam
this technique allows the variation of chromaticity with radial position
(Q’’) to be measured with a much higher resolution than is currently
possible using RF modulation. This paper describes this "Head-Tail"
measurement technique and discusses some recent results obtained using
prototype LHC beam (25 ns spacing) in the CERN-SPS.
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| CT07 |
Excitation of Large Transverse Beam Oscillations without Emittance Blow-Up Using the "AC-Dipole" Principle
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82 |
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- O. Berrig, W. Höfle, R. Jones, J. Koopman, J.-P. Koutchouk, F. Schmidt
CERN, Geneva, Switzerland
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The so-called "AC-Dipole" principle allows the excitation of transverse
oscillations to large (several σ) excursions without emittance
blow-up. The idea was originally proposed and tested at BNL for
resonance crossing with polarized beams, using an orbit corrector dipole
with an excitation frequency close to the betatron tune, hence
"AC-Dipole". This method of beam excitation has several potential
applications in the LHC, such as phase advance and β-measurements,
dynamic aperture studies and the investigation of resonance strengths.
The technique was recently tested in the CERN-SPS using the transverse
damper as an "AC-Dipole" providing the fixed frequency excitation.
results from this experiment are presented, along with an explanation of
the underlying principle.
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| PM12 |
The SPS Individual Bunch Measurement System
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192 |
| |
- A. Guerrero, H. Jakob, J.J. Savioz, R. Jones
CERN, Geneva, Switzerland
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The Individual Bunch Measurement System (IBMS)
allows the intensity of each bunch in an LHC batch to be
the measured both in the PS to SPS transfer lines and in
the SPS ring itself. The method is based on measuring the
peak and valley of the analogue signal supplied by a Fast
Beam Current Transformer at a frequency of 40MHz. A
12 bit acquisition system is required to obtain a 1 %
resolution for the intensity range of 5×109 to 1.7×1011
protons per bunch, corresponding to the pilot and ultimate
LHC bunch intensities. The acquisition selection and
external trigger adjustment system is driven by the
200MHz RF, which is distributed using a single-mode
fibre-optic link. A local oscilloscope, controlled via a
GPIB interface, allows the remote adjustment of the
timing signals. The low-level software consists of a realtime
task and a communication server run on a VME
Power PC, which is accessed using a graphical user
interface. This paper describes the system as a whole and
presents some recent uses and results from the SPS run in
2000.
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| PM17 |
First Beam Tests for the Prototype LHC Orbit and Trajectory System in the CERN-SPS
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207 |
| |
- D. Cocq, L. Jensen, R. Jones, J.J. Savioz
CERN, Geneva, Switzerland
- D. Bishop, B. Roberts, G. Waters
TRIUMF, Vancouver, Canada
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The first beam tests for the prototype LHC orbit and
trajectory system were performed during the year 2000 in
the CERN-SPS. The system is composed of a wide-band
time normaliser, which converts the analogue pick-up
signals into a 10 bit position at 40MHz, and a digital
acquisition board, which is used to process and store the
relevant data. This paper describes the hardware involved
and presents the results of the first tests with beam.
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