Alignment : Hardware

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Alignment Hardware Software Status Henrich
Heitmann, Julien Marque with the contribution of
INFN Frascati, Mario Favati, Dominique Le
Galliot, Alain Masserot, Flavio Nocera, Tatania
Zelenova
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Contents

• Hardware review
• Software review
• Last upgrades
• a. Rearrangement of crate C34b. The 9th
  quadrant c. Global Control newsd. The offset
  issue

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1a. The quadrant (Frascati)
 

• Silicon photodiode, type EGG YAG 444
• sensitivity 0.45 A/W
• DC power 2.77 mWmax
• transimpedance 2 k ?
• Bias voltage 180 V

 
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1b. Quadrant electronics (Frascati)
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1c. The translation stages (Frascati)
2 translation stages / quadrant(PI/M-125.90)1
translation stage control module 4 translation
stages control boards quadrant power supply
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1d. Flippers, Shutters (Frascati)
Shutter used to measure DC offsets.-
shutter control card by Frascati. Mirrors (or
neutral densities) mounted on flip-mount to
attenuatethe light when diode used in 2
different configurations recombined/recycled
(ratio of 1000 in DC power).- will install next
week proper power supply.- need for their own
electronics?
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2a. The photodiode readout, translation stage
control (LAPP/Napoli)
Phase tuning,Gain controlQuadrant motion
control
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2b. The Global Control (LAL)
Compute correction signals to be sent to the
DSP of each mirror to be applied to the reference
mass
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2c. The automation (LAPP/Napoli)
Alignment automation consits of prealignment of
the direct beam, prealignment of the north and
west arm cavities, closing linear alignment loops
on all mirror.
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2d. The alignment UI (EGO)
Used for the commissioning of the linear
alignment (need to migrate to Labview?)
automatic measurement and reconstruction of the
optical matrix (Maddalena, Gabriele)
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3a. Rearrangement of the electronics
Operation needed to-separate analogic fron
digital electronics-accommodate the electronics
for the 9th quadrant Hardware monitoring
completedNew electronics for DC remote control
gain
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3b. The 9th Quadrant
Everything installed but the cables (
problem of communication between a 3rd
translation stage driver and the rio to be
fixed) No more spare!!!!! Need for a 10th
quadrant next year?
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3c. Global Control news
New features for the alignment part of GC-All
matrices on the fly,-Integrated filters in GC
(output and input),-Possibility to inject
coherent lines on all mirrors for matrix
measurement comodity, Need to write some code
still
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3d. The offset issue
Where the offsets of AC error signals are coming
from? a)DC offsets between different elements of
the quadrant gt beam not centered on diode gt
coupling with longitudinal signals gt offset on
alignment AC signals This should have been fixed
by a better DC tuning b)Multireflection in the
splitters of the optical setup gt secondary beam
combined with main beam gt offset on alignment AC
signal Optics with 3 degrees wedge have been
acquired will be installed soon