Abstracts Brochure - CERN

THPLS135
THPLS136
THPLS137
29-Jun-06 16:00 - 18:00 THPLS — Poster Session
The Study of Errors of ALBA Fixed Stretched Wire Bench
The new synchrotron radiation source ALBA
J. Marcos, J. Campmany (ALBA)
to be built nearby Barcelona is planned to
start operation in 2009. The facility includes
a laboratory for magnetic measurements laboratory devoted to IDs. The stretched wire measurement technique is
widely used to obtain magnetic field integrals. This technique is based upon the displacement of a stretched wire
relative to the magnetic structure to be measured. In the most usual configuration, the magnets are kept fixed while
the wire is moved. This arrangement is especially well suited for measuring big structures such as full undulators or
its jaws. In contrast, in the fixed stretched wire configuration the magnetic structure is moved relative to a stationary
pick-up coil with a straight segment. This layout is convenient for the measurement of small units, such as individual
magnet blocks or magnetic modules. These measurements allow characterising the inhomogeneities of the building
blocks of an undulator. In this paper we present an exhaustive analysis of error sources and tolerance requirements
for a particular design of a fixed stretched wire bench made at ALBA, based both in the ESRF, SOLEIL and BESSY
previous existing designs.
Measurement of Multipoles of Permanent Magnets
When assembling an insertion device before
Z. Martí (LLS) J. Campmany (ALBA)
shimming, sorting algorithms are used to reduce
the field errors by choosing the best
arrangement of magnetic blocks. In order to carry it out, magnets to be placed in the array are measured with
the Helmholtz coil. This yields the magnetic dipolar moment of each one. In fact, Helmholtz coil measurements
assume a dipolar filed for each block. The development of narrow gap insertion devices yields a growing interest
in the effect of magnetic inhomogeneities. Magnetic inhomogeneities introduce multipolar terms that are added to
those corresponding to the multipole development of an ideal magnetic source. However, magnetic inhomogeneities
are not measured so far with the Helmholtz coil, because it evaluates the magnetic field far from the magnet, and the
multipolar terms decay faster than the dipolar with distance. In order to take into account inhomogeneities, a new
approach could be used, based on the measurement of multipoles corresponding to each block. In this paper we
propose a method for the fast measurement of the multipoles corresponding to an arbitrary magnetic block, using a
Hall probe scanning along a single straight line.
Insertion Devices for the MAX IV Light Source
The foreseen insertion devices and expected
E.J. Wallén, B. N. Jensen, U. Johansson (MAX-lab)
brilliance for the MAX IV light source are
presented. The planned MAX IV light source
consists of three low emittance storage rings and a 3 GeV linac. The linac is used as a full energy injector. The three
storage rings will be operated at 700 MeV, 1.5 GeV, and 3.0 GeV, which makes it possible to cover a large spectral range
from IR to hard X-rays with insertion devices optimised for each storage ring.
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