| Paper |
Title |
Other Keywords |
Page |
| IT04 |
Challenges for LHC and Demands on Beam Instrumentation
|
instrumentation, collimation, luminosity, superconducting-magnet |
15 |
| |
- J. Wenninger
CERN, Geneva, Switzerland
| |
The LHC machine presently under construction at CERN will exceed existing
superconducting colliders by about one order of magnitude for luminosity
and beam energies for pp collisions. To achieve this performance the
bunch frequency is as large as 40 MHz and the range in beam intensity
covers 5·109 protons to 3·1014 protons with a normalised
beam emittance as small as 3 μmrad. This puts very stringent demands on the beam
instrumentation to be able to measure beam parameters like beam
positions, profiles, tunes, chromaticities, beam losses or luminosity.
The presentation will pick out interesting subjects of the LHC beam
instrumentation field. The examples will be chosen to cover new detection
principles or new numerical data treatments, which had to be developed
for the LHC as well as aspects of operational reliability for
instrumentation, which will be used for machine protection systems.
|
|
|
|
| PM08 |
Recent Advances in the Measurement of Chromaticity Via Head-Tail Phase Shift Analysis
|
diagnostics, instrumentation, chromatic effects, SPS |
107 |
| |
- N. Catalan-Lasheras, S. Fartoukh, R. Jones
CERN, Geneva, Switzerland
| |
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.
|
|
|
|
| PT08 |
The LHC Orbit and Trajectory System
|
diagnostics, closed-orbit, controls, instrumentation |
187 |
| |
- E. Calvo-Giraldo, C. Boccard, D. Cocq, L. Jensen, R. Jones, J.J. Savioz
CERN, Geneva, Switzerland
- D. Bishop, G. Waters
TRIUMF, Vancouver, Canada
| |
This paper describes the definitive acquisition system selected for the
measurement of the closed orbit and trajectory in the CERN-LHC and its
transfer lines. The system is based on a Wide Band Time Normaliser (WBTN)
followed by a 10-bit ADC and a Digital Acquisition Board (DAB), the
latter developed by TRIUMF, Canada. The complete chain works at 40 MHz, so
allowing the position of each bunch to be measured individually. In order
to avoid radiation problems with the electronics in the LHC tunnel, all
the digital systems will be kept on the surface and linked to the
analogue front-ends via a single mode fibre-optic connection. Slow
control via a WorldFIP fieldbus will be used in the tunnel for setting
the various operational modes of the system and will also be used to
check power supply statuses. As well as describing the hardware involved,
some results will be shown from a complete prototype system installed on
four pick-ups in the CERN-SPS using the full LHC topology.
|
|
|
|
| PT27 |
A 40 MHz Bunch by Bunch Intensity Measurement for the CERN SPS and LHC
|
diagnostics, instrumentation, SPS |
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.
|
|
|
|