| Paper | Title | Other Keywords | Page | ||
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| IT07 | Accelerator Physics Experiments with Beam Loss Monitors at BESSY | instrumentation, diagnostics, BESSY | 31 | ||
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The extended use of beam loss monitoring has led to a better
understanding of the linear and non-linear physics involved in the single
and multiple particle dynamics at BESSY. This knowledge has been used for
improving the performance of the light source in terms of lifetime, beam
stability, and stability of the energy.
The key to these experiments are loss monitors placed at strategic
locations of the ring with high sensitivity to Touschek or Coulomb
scattered particles.
Coulomb-scattering depends strongly on the transverse dynamics which is
determined by the magnetic guiding fields. Losses occur primarily at the
vertical aperture restrictions imposed by the flat insertion device
vacuum chambers. Tune scan measurements clearly show resonances produced
by the lattice magnets and by some of the insertion devices.
Touschek scattering depends on the 3-dimensional electron density and the
spins of the colliding particles. In transfer function type experiments
these dependencies have been used to observe the effect of resonant
transverse and longitudinal beam excitations. Loss monitors allow to
detect excited head-tail and higher longitudinal modes which are
invisible in the center of mass motion. Another application is the
detection of the resonant destruction of the spin polarization of the
ensemble of electrons. This is used routinely in order to determine the
beam energy with high accuracy.
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| CT04 | Fibre Optical Radiation Sensing System for TESLA | instrumentation, diagnostics, linear-collider, fibre-optics, TESLA, TTF | 73 | ||
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High energy accelerators generate ionising radiation along the beam-line
and at target places. This radiation is related to beam losses or dark
currents. The in-situ measurement of this ionising dose that is
distributed over long distances or large areas requires a new monitor
system. This paper presents first results and the concept of such a
monitor system at the Tesla Test Facility.
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| PS11 | Test of Different Beam Loss Detectors at the GSI Heavy Ion Synchrotron | instrumentation, diagnostics, GSI, synchrotron | 129 | ||
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For the sensitive process of slow extraction from a synchrotron
a reliable control of the beam losses is needed.
We have tested several types of particle detectors mounted
at the extraction path of the SIS: A BF-tube for pure neutron
detection, a liquid and a plastic scintillator detecting
neutrons, gammas and charged particles and an Argon filled
ionization chamber mainly sensitive to charged particles.
While the count rate is quite different, the time evolution of
all detector signals during the spill are similar, but the plastic
scintillator has the highest dynamic range. This type is
going to be used for beam alignment.
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| PM14 | LHC Beam Loss Monitors | instrumentation, diagnostics, LHC, collider, simulation | 198 | ||
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At the Large Hadron Collider (LHC) a beam loss
system will be installed for a continuous surveillance of
particle losses. These beam particles deposit their energy
in the super-conducting coils leading to temperature
increase, possible magnet quenches and damages.
Detailed simulations have shown that a set of six
detectors outside the cryostats of the quadrupole magnets
in the regular arc cells are needed to completely diagnose
the expected beam losses and hence protect the magnets.
To characterize the quench levels different loss rates
are identified. In order to cover all possible quench
scenarios the dynamic range of the beam loss monitors
has to be matched to the simulated loss rates. For that
purpose different detector systems (PIN-diodes and
ionization chambers) are compared.
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| DS06 | Beam Loss Monitors
Discussion Session 6: Tuesday Morning (11:30--13:00 Hrs) |
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