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Methoden und Instrumentierung Poster: Mi., 14:00–16:30 M-P83
Insertion Devices for the PETRA III Storage Ring
Markus Tischer 1 , Miriam Barthelmeß 1 , Martin Bräuer 1 , Uwe Englisch 1 ,
Joachim Pflüger 1 , Jochen Skupin 1
1 Deutsches Elektronen-Synchrotron (DESY), HASYLAB, Notkestr. 85, 22603 Ham-
burg, Germany
The PETRA ring at DESY, presently used as a booster ring, will be reconstructed
and converted to a dedicated 3rd generation light source in the years 2007/2008 [1].
One octant of the machine will be completely remodeled for installation of 14 undulator
beamlines with unprecedented brilliance, particularly suited for experiments with
small or diluted samples requiring small beam size or extreme focusing conditions.
PETRA III will operate in top-up mode at an energy of 6 GeV with a beam current
of 100 mA. The first stored electron beam is expected for the end of 2008, first photon
beam and start of beamline commissioning in early 2009. The emittance of the
new storage ring will be brought down to 1 nmrad by means of 20 permanent magnet
damping wigglers [2].
In the remodeled octant 8 straight sections will be available for installation of 5 m
long insertion devices (IDs). To enlarge the number of independently operable beamlines,
five of these sections will be used for two 2 m long undulators with a 5 mrad
bend in-between. Furthermore, the straight section at the beginning of the octant
provides space for installation of a 20 m long undulator.
There will be 7 different undulator types, the majority of which are conventional, planar
hybrid undulators of 2 m and 5 m length with two different period lengths. In addition,
five special undulators have been assigned, including a quasi-periodic undulator
with shifted higher harmonics and an APPLE2 device for circularly and elliptically
polarized radiation in the VUV region. Furthermore, two hard X-ray IDs for 30
and 100 keV photons and the 20 m undulator are in the design phase.
A common development of undulators has been started for PETRA III and the European
XFEL [3], the other large future project at DESY to be realized until 2012. Aside
from minor differences the undulator requirements in both projects have a lot in common
regarding their magnetic properties, mechanical stability, and precision of the
motion control system. First devices, which will be available in the near future, are
expected to meet the more demanding requirements regarding specification and performance
of either project.
[1] K. Balewski et al. (Ed.), PETRA III Technical Design Report, DESY 2004-
035 (2004); http://petra3.desy.de
[2] M. Tischer et al., Damping Wigglers for the PETRA III Light Source, JACoW conference
proceedings PAC 2005 (2005), 2446-2448
[3] M. Altarelli et al. (Ed.), The European X-Ray Free-Electron Laser XFEL, Technical
Design Report (2006), in preparation; http://xfel.desy.de