Abstracts Brochure - CERN

TUPCH015
TUPCH016
TUPCH018
27-Jun-06 16:00 - 18:00 TUPCH — Poster Session
Integrated Beam Diagnostics Systems for HICAT and CNAO
An integrated system for beam diagnostics
A. Reiter, A. Peters, M. Schwickert (GSI)
was produced at GSI for the heavy-ion cancer
treatment facility HICAT of the Heidelberg
university clinics. A set of 92 manifold beam diagnostic devices allows automated measurements of the main beam
parameters such as beam current, profile or energy. The beam diagnostic subsystem is completely integrated in the
overall accelerator control system and its timing scheme. This paper reports on the underlying design patterns for
the abstraction of the beam diagnostic devices towards the control system. Event-counting devices, i.e. scintillating
counters and ionization chambers, are presented as examples of the diagnostic devices in the synchrotron and highenergy
beam transport section of HICAT. Additionally, it is shown that the well-defined building blocks of the beam
instrumentation made it possible to prepare almost identical devices including the manual control software, to be
used in the CNAO facility (Centro Nazionale di Adroterapia Oncologica) presently under construction in Pavia, Italy.
Numerical Simulation of Synchrotron Radiation for Bunch Diagnostics
For the operation of the VUV-FEL at DESY,
A. Paech, W. Ackermann, T. Weiland (TEMF) O. Grimm (DESY) Hamburg, the longitudinal charge distribution
of the electron bunches that drive the
free electron laser is of high importance. One novel method to measure the bunch shape is to analyze the coherent
far-infrared synchrotron radiation generated at the last dipole magnet of the first bunch compressor. For the correct
interpretation of the results it is mandatory to know how various parameters, like the bunch shape and path, the
vacuum chamber walls, the optical beamline, etc., influence the observed spectrum. The aim of this work is to
calculate the generation of synchrotron radiation inside the bunch compressor with the emphasis of including the
effects of the vertical and horizontal vacuum chamber walls in the vicinity of the last dipole magnet. Challenging
problems for the numerical simulations are the very short wavelength and the broad frequency range of interest. As
a first step, it is shown how the radiation leaving the vacuum chamber, that is generated by a single point charge, can
be calculated with the help of the uniform theory of diffraction (UTD).
Fast Beam Dynamics Investigation Based on an ADC Filling Pattern Measurement
A diagnostic tool to determine the longitudi-
J. Kettler, P. Hartmann, R.G. Heine, T. Weis (DELTA)
nal particle filling pattern has been installed
at the 1.5 GeV electron storage ring DELTA.
The instrument is PC-based using an ADC-conversion at a sampling rate of 2 GS/s and a nominal bandwidth of 1
GHz which is applied to the sumsignal of a single storage ring beam position monitor. By sampling over successive
turns the resolution is enhanced by one order of magnitude allowing an easy access to the longitudinal particle
distribution inside the ring. The data obtained turn-by-turn over hundreds of revolutions can be further analysed by
FFT-techniques allowing a very fast detection (∼ 1 s) of longitudinal coupled bunch mode (CBM) instabilities from the
phase modulated spectrum. The application of the FFT to the amplitude modulated particle distribution moreover
allows a "post mortem"-investigation of CBM induced beam loss. The paper will present the layout of the diagnostic
system and will report on filling pattern measurements as well as on investigations of longitudinal CBM-instabilities.
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