Paper | Title | Other Keywords | Page | ||
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IT07 | Bunch Length Measurements | electron, laser, radiation, gun | 19 | ||
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An rf photo-injector in combination with a magnetic
bunch compressor is suited to produce high-charged sub-picosecond
electron bunches required for electron-drive
linacs for VUV and X-ray FELs. This report summarizes
time- and frequency domain bunch length measurement
techniques with sub-picosecond resolution.
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IT09 | Diagnostics in Heavy Ion Machines | ion, heavy-ion, diagnostics, electron | 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 |
diagnostics, emittance, ion, 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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PS05 | Recent Improvements of a Cryogenic Current Comparator for nA Ion Beams with High Intensity Dynamics | ion, pick-up, heavy-ion, instrumentation | 109 | ||
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Former measurements of extracted ion beams from the
GSI heavy ion synchrotron SIS showed large current fluctuations
in the microsecond region with a high peak-to-average
ratio. To adapt our Cryogenic Current Comparator
(CCC) to this time structure the detectors electronics have
been carefully modified.
The most important improvement of the new DC
SQUID system affects the enlargement of the bandwidth
and the slew rate of the measuring system. In addition the
existing data acquisition system for e.g. SEMs (Secondary
Emission Monitors) was extended to digitize the CCC signals
simultaneously. Measurements of Argon beams will
be shown to demonstrate the improved capabilities of the
upgraded Cryogenic Current Comparator.
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PS07 | Trajectory Measurements in the DAΦNE Transfer Lines | pick-up, damping, injection, 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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PT07 | Emittance measurements at the new UNILAC-pre-stripper using a pepper-pot with a PC-controlled CCD-camera | emittance, ion, laser, ion-source | 171 | ||
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The complex mathematical algorithms and procedures
to extract emittance data from intensity distributions
measured with a single shot pepper-pot device are
described. First results of mathematical evaluation from
the commissioning of the new GSI pre-stripper linac
structures are presented.
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PT10 | Emittance and dispersion measurements at TTF | emittance, quadrupole, dipole, acceleration | 180 | ||
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It is well known that beam dispersion , along with the
Twiss parameters and emittance, contributes to the beam
spot size. So that, in general, anomalous dispersion is an
undesirable event and must be minimized by careful tuning
the machine. If not, when the spot size is used to infer
beam emittances, as it is the case of the "quadrupole
scan" method, basically employed at TTF, the unknown
dispersion can lead to overestimated values for the emittance.
This paper presents the first attempt to determine the
dispersion function at several points of the TTF Linac and
to separate its contribution to the local emittance measurement,
performed by means of the OTR imaging technique.
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PT14 | Experience with stripline beam position monitors on the TESLA test facility LINAC | quadrupole, alignment, lattice, beam-transport | 190 | ||
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Measurement and correction of beam position are very
important for the optimization of beam characteristics and
alignment in the Tesla Test Facility (TTF) linac. We
describe and present measurements with beam of the
performance of the stripline beam position monitors
(BPMs) in operation and in order to determine the beam
response.
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PT17 | Role of pre-wave zone effects in TR-based beam diagnostics | radiation, diagnostics, electromagnetic-fields, 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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