Hall probe measurements
The magnetic field is measured with
a Hall probe system moving along
the wiggler axis in order to find the
gap (FEMTOSLICING operational gap)
corresponding to a resonant energy of 780
nm. The magnetic field reaches 1.85 T at
the minimum gap and 1.66 T at the 16.7
mm FEMTOSLICING operation gap (Fig.
➌
).
Field integral measurements
Field integral measurements enable
to deduce the kick angle experienced
by the electron beam at the exit of
the wiggler which should vanish if the
wiggler is perfect. A six meter air coil
travelling transversally in the median
plane of the wiggler is used to evaluate
both the residual horizontal and vertical
field integrals and their transverse
homogeneity.
The characterization of the wiggler using
the electron beam has started just after
its installation (October 2013) in the ring.
It has been verified first that the wiggler
can be closed at minimum gap with a 500
mA stored beam without damaging the
front end absorber. A special tuning of the
storage ring optics has been optimized
to operate the wiggler at 16.7 mm gap
for the FEMTOSLICING experiments. As
expected, due to the high field value, the
horizontal emittance is increased by 10%
at minimum gap. The effects on the main
electron beam parameters (tunes and
chromaticities) have been measured and
the very good agreement with expected
values confirms the high quality of the
magnetic measurements. In a second step
it is intended on the one hand to study
the effect of the wiggler on beam lifetime
and injection rate, in order to evaluate the
efficiency of the compensation system.
On the other hand optical performances
of the wiggler such as laser-synchrotron
radiation overlap, spatial and spectral
photon distribution will be measured.
Magnetic measurements
On beam commissioning
Magnetism & Insertions group
ASSOCIATED PUBLICATION
O. Marcouillé*, H. Abualrob, P. Brunelle, L.
Chapuis, M.-E. Couprie, T. Elajjouri, M. Labat,
J.-L. Marlats, A. Mary, A. Nadji, K. Tavakoli and
M.-A. Tordeux
*Synchrotron SOLEIL, l’Orme des Merisiers,
St Aubin BP48, 91192 Gif sur Yvette Cedex,
France
CORRESPONDING AUTHOR
➋
Measured magnetic field of W164 at minimum gap (14.5 mm) and FEMTOSLICING operational gap (16.7 mm).
REFERENCES
[1] A. Zholents & Zoloterev, Phys. Rev. Let
76 (1996), 912
[2] A. Nadji et al. Proc. of EPAC2004
conference, Lucerne, Switzerland
2332 (2004)
[3] PUMA website:
/
IPANEMA/methodessynchrotron#puma
[4] J. Safranek et al. Phys. Rev. ST Accel. Beams
2002 Vol. 5, 010701
139
SOLEIL
HIGHLIGHTS
2013
