Abstracts Brochure - CERN

WEPCH011
WEPCH012
WEPCH013
WEPCH014
28-Jun-06 16:00 - 18:00 WEPCH — Poster Session
Optimisation of a New Lattice for the ESRF Storage Ring
The installation of canted undulators in some
A. Ropert, L. Farvacque (ESRF)
of the straight sections of the ESRF storage
ring is envisaged in the future. In order to
free maximum space in the straight sections and minimise the reduction in length of the undulators, a new lattice,
in which the straight section quadrupole triplets are replaced by doublets, is being studied. The paper describes the
main features of the lattice and presents the experimental results achieved so far.
Comparison of Betatron Function Measurement Methods and Consideration of Hysteresis
Effects
Two methods for determining the betatron
O. Kopitetzki, D. Schirmer, G. Schmidt, K. Wille (DELTA)
functions in a storage ring were used to survey
the linear optics at Delta (Dortmund
Electron Accelerator). On the one hand the fast orbit response analysis is used to gain betatron functions at the
beam position monitors and dipole correctors. These are compared to betatron functions measured by the tune scan
method. For higher accuracy of the betatron functions obtained by the tune scan method a measuring procedure is
introduced, which considers the hysteresis effects in the quadrupole magnets. Systematic deviations in the beta functions
measured between the two methods have been observed. The calibration errors of the beam position monitors
can explain the observed deviations. With the orbit response analysis also the betatron phase advances between the
measurement points can be calculated. Because these do not depend on the calibration errors, unlike the betatron
functions, the differences between measurement and model can be determined more precise. A comparison of both
methods with the optics model will be presented.
Electron Transport Line Optimization by Using Neural Networks and Genetic Algorithms
D. Schirmer, P. Hartmann (DELTA) T. Buening, D. Mueller (New
Affiliation Request Pending)
276
Methods of computational intelligence (CI)
were investigated to support the optimization
of the electron transfer efficiency from
the booster synchrotron BoDo to the electron
storage ring DELTA. Neural networks and genetic algorithms were analysed alternatively. At first both types of
methods were trained on the basis of a theoretical model of the transport line. After the training various algorithms
were used to improve the magnet settings of the real transport line elements with respect to the electron transfer
efficiency. The results of different strategies are compared and prospects as well as limitations of CI-methods to the
application of typical optimization problems in accelerator operation are discussed.
Linear Optics Measurement at the VUV-FEL
A series of experiments have been carried out
C. Gerth, B. Beutner, L. Fröhlich, M. Roehrs, H. Schlarb (DESY) in order to study the linear optics at the VUV-
FEL at DESY. The full understanding of the
linear beam optics and the correct matching of the electron beam from the injector to the undulator are of major
importance for a reliable and stable operation of the VUV-FEL. Orbit response matrix measurements have been