Paper |
Title |
Other Keywords |
Page |
IT03 |
Beam Loss Monitors at the ESRF
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beam-losses, vacuum, injection, synchrotron |
3 |
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- B. Joly, U. Weinrich, G.A. Naylor
ESRF, The European Synchrotron Radiation Facility, Grenoble, France
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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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IT07 |
Bunch Length Measurements
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electron, laser, linac, gun |
19 |
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IT12 |
Use of Superimposed Alternating Currents in Quadrupoles to Measure Beam Position with Respect to their Magnetic Centre
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quadrupole, electron, storage-ring, lattice |
38 |
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- N. Marks
CLRC, Daresbury Laboratory, Warrington, UK
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The positional stability of the electron beam in a modern
state-of-the-art synchrotron radiation source is critical, as
the many experimental users require consistency in the
position and dimensions of the incoming photon beams
which are incident on their experimental samples. At the
Daresbury Synchrotron Radiation Source (SRS),
inaccuracies in the measurements of the positions of both
beam position monitors and the lattice quadrupoles can be
overcome by measuring the position of the electron beam
with respect to the magnetic centres of the quadrupoles.
This was achieved by superimposing an alternating
('ripple') current on the direct current excitation of a
single lattice quadrupole and examining the resulting
beam oscillations at remote positions in the storage ring.
If the electron beam is then subjected to a local distortion
at the position of this quadrupole, the amplitude of the
beam oscillation induced by the superimposed current is
minimised (nominally zero) when the beam is at the
quadrupole's magnetic centre. This paper presents details
of the electrical circuit developed to inject an alternating
current into the coils of individual quadrupoles and gives
details of the results achieved to date.
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CT08 |
Adaptive Optics for the LEP 2 Synchrotron Light Monitors
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synchrotron, extraction, synchrotron-radiation, optics |
77 |
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- G. Burtin, R.J. Colchester, G. Ferioli, J.J. Gras, R. Jung, J.M. Vouillot
CERN, Geneva, Switzerland
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The image obtained with the LEP synchrotron
radiation telescopes deteriorates, giving multiple and
deformed images, when the beam energy goes beyond
80 GeV at beam currents above 2 mA. This problem is
due to the deformation of the light extracting beryllium
mirror, by as little as 1 mm, and had been predicted at
the design stage. To overcome this problem, several
changes together with an adaptive optics set-up have
been introduced. These essentially consist of a
cylindrically deformable mirror to compensate the
cylindrical deformation of the beryllium mirror and a
movable detector to compensate the spherical
deformation. Both components are continuously
adjusted as a function of beam current and energy.
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CT10 |
Real Time Display of the Vertical Beam Sizes in LEP Using the BEXE X-Ray Detector and Fast VME Based Computers
|
positron, electron, luminosity, synchrotron |
87 |
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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, kicker |
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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PT04 |
Radiation protection system installation for the accelerator production of tritium/low energy demonstration accelerator project (APT/LEDA)
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radio-frequency, controls, beam-transport, rfq |
162 |
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- J.E. Wilmarth, M.T. Smith, T.L. Tomei
LANL, Los Alamos National Laboratory, Los Alamos, NM, USA
|
The APT/LEDA personnel radiation protection system
installation was accomplished using a flexible, modular
proven system which satisfied regulatory orders, project
design criteria, operational modes, and facility
requirements. The goal of providing exclusion and safe
access of personnel to areas where prompt radiation in the
LEDA facility is produced was achieved with the
installation of a DOE-approved Personnel Access Control
System (PACS). To satisfy the facility configuration
design, the PACS, a major component of the overall
radiation safety system, conveniently provided five
independent areas of personnel access control. Because of
its flexibility and adaptability the Los-Alamos Neutron-
Science-Center-(LANSCE)-designed Radiation Security
System (RSS) was efficiently configured to provide the
desired operational modes and satisfy the APT/LEDA
project design criteria. The Backbone Beam Enable
(BBE) system based on the LANSCE RSS provided the
accelerator beam control functions with redundant,
hardwired, tamper-resistant hardware. The installation
was accomplished using modular components.
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PT16 |
Status of the delta synchrotron light-monitoring-system
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synchrotron, synchrotron-radiation, shielding, emittance |
196 |
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- U. Berges, K. Wille
DELTA, Institute for Accelerator Physics and Synchrotron Radiation, University of Dortmund, Germany
|
A synchrotron radiation source like DELTA needs an optical
monitoring system to measure the beam size at different
points of the ring with high resolution and accuracy.
The measurements with the present synchrotron light
monitors show that beam sizes larger than 250 μm can be
measured. The measured emittance is of the order of the
theoretical values of the optics and goes down to 8 nm rad.
The magnification of the system can simply be increased
by adding another lens to measure smaller emittances and
beamsizes down to 100 μm. In this case you still have
an optical image of the beam available, but sometimes the
position of the camera has to be adapted due to the great
magnification of the optical system. The image processing
system which is based on a VME Framegrabber makes a
two dimensional gaussian fit to the images from different
synchrotron light-monitors.
First tests with monochromatic components of the synchrotron
radiation (500 nm and 550 nm) and with short
time cameras (shutter time down to 1/10000 s) have been
performed. A two-dimensional PSD has been installed to
measure slow beam motion. To measure small beam sizes,
especially in the vertical plane, diffraction elements will be
used.
This paper gives an overview over the present installation
and the results.
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PT17 |
Role of pre-wave zone effects in TR-based beam diagnostics
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diagnostics, electromagnetic-fields, linac, background |
199 |
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- V.A. Verzilov
INFN-LNF, Laboratori Nazionali di Frascati dell'INFN, Frascati, Italy
|
Transition radiation (TR) is nowadays intensively exploited
by a number of techniques to characterize different beam
parameters. These methods are based, sometimes implicitly,
on standard formulae, and used often without paying
due attention to their applicability. In particular, standard
expressions are only first-order asymptotic, i.e., strictly
speaking, valid at infinity. In this paper TR is examined in a
spatial domain where conventional results are no more exact
and variations in radiation properties are observed. Under
certain conditions, for example, at long wavelengths or
very high energies the effect is so considerable that should
be taken into account in accurate beam measurements.
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