| Paper | Title | Other Keywords | Page | ||
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| IT03 | Beam Loss Monitors at the ESRF | beam-losses, vacuum, radiation, synchrotron | 3 | ||
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The European Synchrotron radiation facility is a third
generation x-ray source providing x-rays on a continuous
basis. As a facility available to external users, the
monitoring of radiation caused by the loss of high-energy
stored beam is of great concern. A network of beam loss
monitors has been installed inside the storage ring tunnel
so as to detect and localize the slow loss of electrons
during a beam decay. This diagnostic tool allows
optimization of beam parameters and physical aperture
limits as well as giving useful information on the
machine to allow the lifetime to be optimized and
defects localized.
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| IT11 | Beam Diagnostics, Old and New
This is essentially a repeat of 'Beam Diagnostics Revisited', invited talk given at EPAC, Stockholm, June 1998 |
diagnostics, emittance, ion, linac | 33 | ||
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The performance of accelerators and storage rings
depends critically on the completeness and quality of their
beam diagnostic systems. It is essential to equip them
from inception with all the instruments providing the
information on the properties and the behaviour of the
beams, needed during running-in, in operation, and for
development of performance towards the design goal and
often well beyond. Most of the instruments have proven
their worth since decades, but their power has been
increased through the modern means of data acquisition
and treatment. A few new instruments have made their
appearance in recent years, some still under development
and scrutiny for their operational value and precision. The
multi-accelerator chains of today’s and tomorrow’s big
colliders have tight tolerances on beam loss and emittance
blow-up. For beam diagnostics this means a great
challenge for precision and consistency of measurements
all along the chain.
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| CT06 | Developments and Plans for Diagnostics on the ISIS Synchrotron | diagnostics, synchrotron, betatron, resonance | 67 | ||
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Developments of diagnostics on the 800 MeV High
Intensity Proton Synchrotron of ISIS, the Spallation
Neutron Source at the Rutherford Appleton Laboratory in
the UK, are described. Recent upgrades to instrumentation
and control computers have made much more information
readily available, which is valuable for control of a loss
limited, high intensity machine. Measurements on high
intensity beams have fundamental limitations in terms of
accuracy, detail and interpretation. However, it is found
that use of specially configured low intensity diagnostic
beams can provide much detailed information not
otherwise available, which is extremely valuable after
careful interpretation. The methods and systems being
developed to help trouble shooting, to find optimal
conditions rapidly and systematically, and to improve
understanding of high intensity performance are
described.
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| CT11 | The OTR Screen Betatron Matching Monitor of the CERN SPS | betatron, emittance, optics, scattering | 90 | ||
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In order to satisfy the stringent emittance
requirements of LHC, betatron matching monitors,
based on multiturn beam profile measurements, have
been proposed for the SPS and LHC. A test monitor
has been installed for evaluation in the CERN SPS first
in 1996 and improved in 1997. It is based on an OTR
screen and a fast beam profile acquisition system. It
has been used with proton beams to assess the quality
of the betatron matching from the PS to the SPS in
1998. Experience and results are presented.
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| CT12 | Preliminary Test of a Luminescence Profile Monitor in the CERN SPS | proton, vacuum, ion, photon | 95 | ||
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In order to satisfy the tight emittance requirements of
LHC, a non-intercepting beam profile monitor is needed
in the SPS to follow the beam emittance evolution during
the acceleration cycle from 26 to 450 GeV. Beyond 300
GeV, the synchrotron light monitor can be used. To cover
the energy range from injection at 26 GeV to 300 GeV, a
monitor based on the luminescence of gas injected in the
vacuum chamber has been tested and has given
interesting results. This monitor could also be used in
LHC, where the same problem arises. Design and results
are presented for the SPS monitor.
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| PS07 | Trajectory Measurements in the DAΦNE Transfer Lines | linac, pick-up, damping, vacuum | 115 | ||
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An improved beam position monitor system has been
installed in the Transfer Lines (TL) connecting the
DAΦNE Linac to the collider Main Rings through the
Damping Ring, to monitor the beam trajectory and optimize
the transmission efficiency.
Signals from stripline type beam position monitors are
stretched, sampled through Track & Hold circuits and
digitized to 12 bits. The sampling stage is triggered,
according to the timing of the desired beam, to measure
the amplitude of the signals induced on a BPM.
Hardware control, data collection and reconstruction of
the beam position along the Transfer Lines are performed
by the DAΦNE Control System on a VME standard local
processor.
Design issues, implementation and performance of the
system are presented.
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| PS09 | Beam Steering With Image Processing In The Cryring Injection Beamline | quadrupole, ion, focusing, synchrotron | 118 | ||
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By varying six quadrupoles and observing how the
beam spot moves on three fluorescent screens the beam is
aligned in the injection beamline. The method is now
automated and upgraded by using image processing of the
picture to get the position of the beam.
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| PS15 | Beam profile measurements at 40 MHz in the PS to SPS transfer channel | proton, ion, radiation, kicker | 135 | ||
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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 | feedback, kicker, dipole, impedance | 138 | ||
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In this paper the bunch-by-bunch transverse feedback
system for suppression fast head-tail as well as coupled
bunch instabilities is described. The experimental results
of the feedback affecting on the current threshold are
presented. The effects of reactive and resistive feedback
on the current threshold are discussed. Two times as large
the bunch current than the threshold current was obtained.
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| PT03 | Measuring beam intensity and lifetime in BESSY II | storage-ring, synchrotron, vacuum, microtron | 159 | ||
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The measurement of the intensity of the beam in the
transfer lines and the storage ring are based on current
transformers. The pulsed current in the transfer lines is
measured with passive Integrating Beam Current
Transformers (ICT). The bunch charge is transferred to a
DC-voltage and sampled with a multifunction I/O-board
of a PC. The beam current of the storage ring is measured
with a high precision Parametric Current Transformer
(PCT) and sampled by a high quality digital volt meter
(DVM). A stand alone PC is used for synchronisation,
real-time data acquisition and signal processing.
Current and lifetime data are updated every second and
send via CAN- bus to the BESSY II control system. All
PC programs are written in LabVIEW.
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| PT08 | A fast protection system for narrow-gap insertion device vessels | monitoring, insertion, beam-losses, insertion-device | 174 | ||
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Presented in this paper are details of an electronic,
beam position based interlock system, which has been
designed to protect narrow - gap insertion device vessels
from the thermal damage that would result from mis
steered beam. Details of system design and operational
experience are presented, and the paper concludes with an
outline proposal for a system enhancement, that would
offer diagnostic information immediately prior to an
excessive beam displacement trip.
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