Paper |
Title |
Other Keywords |
Page |
IT03 |
Beam Loss Monitors at the ESRF
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beam-losses, vacuum, radiation, injection |
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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IT08 |
Controls and Beam Diagnostics for Therapy-Accelerators
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ion, diagnostics, controls, light-ion |
24 |
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- H. Eickhoff
GSI, Gesellschaft für Schwerionenforschung, Darmstadt, Germany
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During the last four years GSI has developed a new
procedure for cancer treatment by means of the intensity
controlled rasterscan-method. This method includes
active variations of beam parameters during the treatment
session and the integration of 'on-line' PET monitoring.
Starting in 1997 several patients have been successfully
treated within this GSI experimental cancer treatment
program; within this program about 350 patients shall be
treated in the next 5 years. The developments and
experiences of this program accompanied by intensive
discussions with the medical community led to a proposal
for a hospital based light ion accelerator facility for the
clinic in Heidelberg. An essential part for patients
treatments is the measurement of the beam properties
within acceptance and constancy tests and especially for
the rasterscan method during the treatment sessions.
The presented description of the accelerator controls and
beam diagnostic devices mainly covers the requests for
the active scanning method, which are partly more crucial
than for the passive scattering methods.
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CT04 |
Bunch Length Measurements in LEP
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pick-up, impedance, photon, monitoring |
59 |
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- A.J. Burns, H. Schmickler
CERN, Geneva, Switzerland
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For many years a streak camera has been used for
observing the longitudinal distribution of the particles in
any LEP e+ or e- bunch (5-50 ps r.m.s. length) on a turn
by turn basis, using synchrotron light. In 1996, a
comparison made with the longitudinal vertex
distributions of 3 LEP experiments allowed the
identification and elimination of certain systematic errors
in the streak camera measurements. In 1997, a new bunch
length measurement technique was commissioned that
uses the high frequency slope of the bunch power
spectrum from a button pickup. In 1998, this new method
was confronted with measurements from the streak
camera and the LEP experiments. The measurements
made in 1996 and 1998 are presented, with emphasis on
the calibration of the two instrumental methods and their
respective precision and limitations.
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CT06 |
Developments and Plans for Diagnostics on the ISIS Synchrotron
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injection, diagnostics, betatron, resonance |
67 |
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- C.M. Warsop, D.J. Adams, K. Tilley
RAL, Rutherford Appleton Laboratory
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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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CT07 |
The ELETTRA Streak Camera: System Set-Up and First Results
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electron, single-bunch, storage-ring, cathode |
72 |
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- M. Ferianis
ELETTRA, Sincrotrone Trieste, Trieste, Italy
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At ELETTRA, a Streak Camera system has been
installed and tested. The bunch length is a significant
machine parameter to measure, as it allows a direct
derivation of fundamental machine characteristics, like its
broadband impedance. At ELETTRA the Light from a
Storage Ring Dipole is delivered through an optical
system to an Optical Laboratory where it can be observed
and analysed.
The Streak Camera is equipped with different timebases,
allowing both single sweep and dual sweep
operation modes, including the Synchroscan mode. The
Synchroscan frequency equal to 250 MHz, which is half
of the ELETTRA RF frequency, allows the acquisition of
consecutive bunches, 2ns apart. To fully exploit the
performances of the Streak Camera, an optical path has
been arranged which includes a fast opto-electronic
shutter. By doing so, the optical power deposited on the
photo-cathode is reduced in the different ELETTRA
fillings.
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CT08 |
Adaptive Optics for the LEP 2 Synchrotron Light Monitors
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extraction, radiation, 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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CT09 |
Luminosity Optimization in DAΦNE
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luminosity, coupling, diagnostics, feedback |
82 |
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- F. Sannibale
INFN-LNF, Laboratori Nazionali di Frascati dell'INFN, Frascati, Italy
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DAΦNE the Frascati F-factory, started the two beams
commissioning on March 1998. Since then a relevant
amount of experience concerning the techniques and procedures
for optimizing the luminosity has been acquired.
All the schemes used are strongly based on the use of
various diagnostic systems including a dedicated luminosity
monitor, orbit measurement, tune monitor, synchrotron
light monitor and others. A summary of the used
techniques, with accent on the diagnostic aspects, is
presented.
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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
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positron, electron, luminosity, radiation |
87 |
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PS02 |
Chromaticity Measurements at HERA-P Using the Head-Tail Technique with Chirp Excitation
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betatron, proton, pick-up, kicker |
103 |
|
- M. Wendt, F. Willeke
DESY, Deutsches Elektronen-Synchrotron, Hamburg, Germany
- A. Boudsko
TRIUMF, Vancouver, Canada
- O.R. Jones, H. Schmickler
CERN, Geneva, Switzerland
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Experiments have been performed in the HERA proton ring
(HERA-p) to test a quasi non-destructive method of chromaticity
measurements for protons. The method is based
on the detection of the head-tail phase shift of coherend betatron
oscillations using a broadband beam position pickup
and a commercial fast-frame oscilloscope. Previous experiments
have relied on a single kick for transverse excitation,
whereas the results presented here were carried out
using swept frequency chirp excitation. The tests proved
to be successful, and the method seems to be a good candidate
for chromaticity measurement in new large hadron
accelerators, such as LHC.
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PS04 |
Influence of transverse beam dimensions on beam position monitor signals
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pick-up, emittance, quadrupole, instrumentation |
106 |
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PS06 |
Turn-By-Turn Phase Space Diagram Construction for Non-Linear Betatron Oscillation
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lattice, betatron, pick-up, simulation |
112 |
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- A. Kalinin, V. Smaluk
BINP, Budker Institute of Nuclear Physics, Novosibirsk, Russia
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The problem of phase space diagram construction for
non-linear betatron oscillation measured by pickup, is
considered. The conventional two-pickup method of
phase trajectory construction was improved. Discrete
Fourier filter applied to data measured yields a large
dividend in accuracy. The result of our investigations is
the method of turn-by-turn phase trajectory construction
using data measured by single pickup. The single-pickup
method developed was tested by computer simulation of
non-linear betatron oscillation in several models of
magnet lattice. Practicality of the method and its accuracy
limitation were studied. The method applying for
experimental study of beam dynamic is discussed.
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PS09 |
Beam Steering With Image Processing In The Cryring Injection Beamline
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quadrupole, injection, ion, focusing |
118 |
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PT02 |
Real-time betatron tune measurement in the accelerator ramp at COSY-Jülich
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betatron, acceleration, diagnostics, feedback |
156 |
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- J. Dietrich, I. Mohos
IKP, Forschungszentrum Jülich GmbH, Jülich, Germany
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A new real-time method for betatron tune measurements
at COSY was developed and tested from the
early 1997. A bandlimited broadband noise source was
used for beam excitation, the transversal beam position
oscillation was bunch-synchronous sampled and digitized
with a high resolution ADC. The Fourier transform of the
acquired data represents immediately the betatron tune.
After the first promising experiments an automatic
tunemeter was constructed. The tunemeter is used as
routine diagnostic tool since end of 1998.
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PT03 |
Measuring beam intensity and lifetime in BESSY II
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storage-ring, vacuum, injection, microtron |
159 |
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- R. Bakker, R. Georgen, P. Kuske, J. Kuszynski
BESSY, Berliner Speicherring-Gesellschaft für Synchrotronstrahlung mbH, Berlin, Germany
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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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PT16 |
Status of the delta synchrotron light-monitoring-system
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radiation, 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
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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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