Speaker
Rainer Wanzenberg
(DESY)
Description
At DESY the PETRA ring has been converted into a synchrotron
radiation facility, called PETRA III. 20 damping wigglers have
been installed to achieve an emittance of 1 nm. The commissioning
with beam started in April 2009 and user runs have been started
in 2010. The design current is 100 mA and the bunch to bunch
distance is 8 ns for one particular filling pattern with 960 bunches.
At a current of about 50 mA a strong vertical emittance
increase has been observed. During machine studies it was found
that the emittance increase depends strongly on the bunch
filling pattern. For the user operation a filling scheme has
been found which mitigates the increase of the vertical
emittance. In Aug. 2010 PETRA III has been operated without
damping wigglers for one week. The vertical emittance growth
was not significantly smaller without wigglers. Furthermore
tune spectra at PETRA III show characteristic lines
which have been observed at other storage rings in the
connection with electron clouds. The measurements at PETRA III
are presented for different bunch filling patterns and with and
without wiggler magnets.
Primary author
Rainer Wanzenberg
(DESY)
