Stability objectives for
the CLIC Main
Beam Quadrupoles (MBQ)
3992 CLIC MBQ should be stable at nanometre
level.
There are four MBQ
types with mass: ~ 100 to 400 kg
and length: 500 to 2000 mm
The
CLIC MBQ stability objectives are given in integrated RMS
displacement at a certain frequency f as shown in the formula
below. Φx
is the power
spectrum density displacement in the x direction.
The
MBQ integrated RMS displacement should be smaller than
1.5 nm at 1 Hz
in vertical direction
and 5nm
at 1 Hz in lateral direction)
The
strategy selected is based on the use of high resolution and
high precision piezo actuators. An additional study is the use
of such actuators to position the MBQ magnets in between beam
pulses with nanometre resolution. Vibrations are measured with
inertial reference masses such as seismometers or geophones.
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