| Paper | Title | Other Keywords | Page | ||
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| IT01 | Review Of Diagnostics For Next Generation Linear Accelerators | instrumentation, diagnostics | 1 | ||
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New electron linac designs incorporate substantial advances in critical
beam parameters such as beam loading and bunch length and will require
new levels of performance in stability and phase space control. In the
coming decade, e- (and e+) linacs will be built for a high power linear
collider (TESLA, CLIC, JLC/NLC), for fourth generation X-ray sources
(TESLA FEL, LCLS, Spring 8 FEL) and for basic accelerator research and
development (Orion). Each project assumes significant instrumentation
performance advances across a wide front.
This review will focus on basic diagnostics for beam position and phase
space monitoring. Research and development efforts aimed at high precision
multi-bunch beam position monitors, transverse and longitudinal profile
monitors and timing systems will be described.
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| IT10 | 6-D Electron Beam Characterisation Using Optical Transition Radiation and Coherent Diffraction Radiation | instrumentation, diagnostics, emittance | 46 | ||
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The development of non-intercepting diagnostics for high charge density
and high energy electron beams is one of the main challenge of beam
instrumentation.
Diffraction Radiation based diagnostics, being non-intercepting, are
among the possible candidates for the measurements of beam properties for
the new generation linacs.
At the 1 GeV Sincrotrone Trieste linac, we are performing the first
measurements of beam transverse parameters using Diffraction Radiation
emitted by the electron beam passing through a 1 mm slit opened on a
screen made of aluminium deposited on a silicon substrate.
The analysis of the angular distribution of the Diffraction Radiation for
a given wavelength, slit aperture and beam energy gives information about
the beam size and its angular divergence.
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| IT12 | Investigations of Longitudinal Charge Distribution in Very Short Electron-Bunches | instrumentation, diagnostics, emittance | 56 | ||
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Electro-optical-sampling is a powerful technique to measure
the longitudinal charge distribution of very short electron
bunches. The electrical field moving with the bunch
induces an optical an-isotropy in a ZnTe crystal which is
probed by a polarized laser pulse. Two measurement principles
are possible. In the first one a short laser pulse of
lengths <50 fs is used directly to scan the time varying
optical properties of the crystal. In the second method the
laser pulse is frequency chirped and the temporal information
is encoded into the time ordered frequency spectrum,
which can be recovered by an optical grating and a CCD
camera.
A resolution in the 100 fs regime can also be achieved
with longitudinal phase space tomography. Acceleration
on the slope of the rf wave at different phases and measurements
of the energy profiles are sufficient for a reconstruction
algorithm based on maximum entropy methods.
The longitudinal phase space distribution can be obtained
without artifacts due to the limited angular range of the
projections.
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| CT04 | Fibre Optical Radiation Sensing System for TESLA | instrumentation, diagnostics, beam-losses, 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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| PS20 | Beam Diagnostic for the Next Linear Collider | instrumentation, diagnostics, NLC | 151 | ||
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The Next Linear Collider (NLC) is proposed to study
e+-e--collisions in the TeV energy region. The small beam spot size
at the interaction point of the NLC makes its luminosity sensitive to
beam jitter. A mechanism for aligning the beams to each other which acts
during the bunch-train crossing time has been proposed to maintain
luminosity in the presence of pulse-pulse beam jitter. We describe a
beam-beam deflection feedback system which responds quickly enough to
correct beam misalignments within the 265 ns long crossing time. The
components of this system allow for a novel beam diagnostic, beam-beam
deflection scans acquired in a single machine pulse.
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| PM09 | Design of a Multi-Bunch BPM for the Next Linear Collider
Work supported by the US Department of Energy, contract DE-AC03-76SF00515 |
instrumentation, diagnostics, NLC, pick-up | 183 | ||
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The Next Linear Collider (NLC) design requires
precise control of colliding trains of high-intensity
(1.4×1010 particles/bunch) and low-emittance beams.
High-resolution multi-bunch beam position monitors
(BPMs) are required to ensure uniformity across the
bunch trains with bunch spacing of 1.4ns. A high
bandwidth (~350 MHz) multi-bunch BPM has been
designed based on a custom-made stripline sum and
difference hybrid on a Teflon-based material. High
bandwidth RF couplers were included to allow injection
of a calibration tone. Three prototype BPMs were
fabricated at SLAC and tested in the Accelerator Test
Facility at KEK and in the PEP-II ring at SLAC. Tone
calibration data and single-bunch and multi-bunch beam
data were taken with high-speed (5Gsa/s) digitisers.
Offline analysis determined the de-convolution of
individual bunches in the multi-bunch mode by using the
measured single bunch response. The results of these
measurements are presented in this paper.
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