Paper | Title | Other Keywords | Page | ||
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IT08 | Controls and Beam Diagnostics for Therapy-Accelerators | ion, controls, light-ion, synchrotron | 24 | ||
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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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IT09 | Diagnostics in Heavy Ion Machines | ion, heavy-ion, electron, linac | 28 | ||
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An overview of the measurements of most important beam
parameters in heavy ion machines is given. The special
characteristics of heavy ions concerning the great variety
of parameters with respect to the type of accelerator (linac,
circular machine), the species of accelerated ions as well
as their energy, beam intensity, beam emittance and time
structure are considered. The consequences for the design
of beam diagnostic systems are discussed. Typical examples
of measuring systems are given. Experimental results
taken during the long operating time of the GSI facilities,
covering a wide range of parameters, are reported.
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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 |
emittance, ion, linac, injection | 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 todays and tomorrows 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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CT01 | Measurements with a versatile Test Bench for Commissioning of the new GSI High Current Linac | emittance, rfq, ion, pick-up | 45 | ||
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For the commissioning of the new GSI prestripper a conventional
slitdetector system and a single shot pepperpot system has been
installed on a mobile test bench to measure intensity distributions in
the two transverse phase spaces. To determine intensity distributions
in the longitudinal phase space, including beam energy capacitive
pickups and newly developed diamond counters have been installed on the
test bench. The setup of the test bench provides also redundant
information for beam current, beam profile and beam position. The most
important features of all measuring systems including signal processing
and data evaluation are reported. First results from the commissioning
of the upgraded prestripper of the UNILAC at GSI are reported.
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CT06 | Developments and Plans for Diagnostics on the ISIS Synchrotron | injection, 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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CT09 | Luminosity Optimization in DAΦNE | luminosity, coupling, feedback, synchrotron | 82 | ||
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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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PS19 | Photon counting detectors for fill structure measurements at visible wavelengths | photon, storage-ring, single-bunch, electron | 144 | ||
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When making accurate measurements of the relative
populations of electron bunches in a storage ring, notably
in light sources operating with only a single bunch filled,
the method of time-correlated single photon counting
gives the greatest dynamic range. The timing resolution
and background noise level of the photon detector
employed is critically important in determining the overall
performance of the system; hitherto the best performance
has been obtained detecting X-ray photons using
avalanche photodiodes. On the SRS at Daresbury a visible
light diagnostic station offers greater ease of access to
instrumentation and operational advantages. A review is
given of the detector types which have been employed,
and the performances which can be obtained using visible
light.
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PT02 | Real-time betatron tune measurement in the accelerator ramp at COSY-Jülich | betatron, synchrotron, acceleration, feedback | 156 | ||
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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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PT15 | High current precision long pulse electron beam position monitor | kicker, electron, instrumentation, target | 193 | ||
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Precision high current long pulse electron beam position
monitoring has typically experienced problems with high
Q sensors, sensors damped to the point of lack of precision,
or sensors that interact substantially with any beam
halo thus obscuring the desired signal. As part of the
effort to develop a multi-axis electron beam transport system
using transverse electromagnetic stripline kicker technology,
it is necessary to precisely determine the
position and extent of long high energy beams for accurate
beam position control (6 - 40 MeV, 1 - 4 kA, 2 μs
beam pulse, sub millimeter beam position accuracy.)
The kicker positioning system utilizes shot-to-shot adjustments
for reduction of relatively slow (< 20 MHz) motion
of the beam centroid. The electron beams passing through
the diagnostic systems have the potential for large halo
effects that tend to corrupt position measurements.
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PT17 | Role of pre-wave zone effects in TR-based beam diagnostics | radiation, electromagnetic-fields, linac, background | 199 | ||
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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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