Transcript H.Heitmann
The Virgo+ shutdown
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Performances before V+ shutdown
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Virgo progress
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Virgo sensitivity: May 2008
H. Heit mann
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Spikes:
relaxation of magnet waterglass
glueing
ILIAS Birmingham, 10/07/2008
Recent upgrades
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
The cryotrap
Brewster window (SR-DT) introduces noise
Several attempts to mitigate scattered light
Baffles in detection and SR towers, near the Brewster, …
Final decision: remove it
Avoid spoiling of central area vacuum from detection tower
=> cryotrap
Cryotrap installation shutdown 10 days
Interferometer locked immediately afterwards
Signal
recycling
H. Heit
mann
Detection
tower
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ILIAS Birmingham, 10/07/2008
To ext. detection bench
Nice success of the vacuum group
Cryotrap functioning
Duration of functioning 3 days
Refilling takes 1 hour
Project of increasing functioning time to >= 1 week
Before the next science run
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
DAQ room air conditioning upgrade
Air conditioning systems affects the Virgo sensitivity
DAQ room is just in front of the detection lab
the noise of its (oldest) air conditioning system has been found
directly in the dark fringe
DAQ room (+CE hall)
North End AC
CleanRooms AC
Laser lab
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mann
AC ON
AC OFF
Central hall AC
Water pump of CE
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ILIAS Birmingham, 10/07/2008
DAQ room air conditioning upgrade
DT
lab
DT
SR
Acoustic isolation of the DAQ
=> reduce noise in central area
New AC system outside DAQ
Microphone sees a noise reduction
wrt. to the previous situation.
301
70
32
AC
120
200
119
90
232.5
233.5
60
UTA
157
137.5
430
H. Heit
mann
Hz
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before
after
AC off
ILIAS Birmingham, 10/07/2008
Thermal compensation system
Thermal lensing in the input mirrors has had a strong impact on
commissioning
Complicated locking procedure for surviving thermal transient
Bistabilities arise during transition
Be sure to catch the good state for continuing locking
We want to go from 8 to 25 Watt in Virgo+
Much higher power => no hope to survive thermal deformations
=> Thermal compensation system needed
CO2 laser ring system designed and realized by Roma Tor Vergata
group with support by EGO
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
TCS layout
Chiller
Electronics
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
TCS optical layout
Beam dump
L4
Power meter
AXICON
Half waveplate
2" Hot mirror
L2M
L1 Beam splitter Polarizer
Aiming laser
LASY-20S
H. Heit
mann
L7
AOM
L8
Beam splitter
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ILIAS Birmingham, 10/07/2008
TCS in-vacuum optics
In vacuum steering mirrors needed
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
TCS in-vacuum optics
In vacuum steering mirrors needed
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
TCS status
CO2 laser problems
One of the two lasers arrived broken from the company (Access Laser)
Sent back but delivered again out of order
Probably an undetected CO2 gas leakage
Sent back to the company a second time
WI TCS commissioning started
Still many things to be learned, but:
First encouraging results (see Enrico’s talk)
To be done
Power stabilization to be realized in the next months
Central spot needed for reducing thermal transient time?
Continue commissioning as soon as interferometer available again
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
The Eddy current issue
Increase of thermal noise due to Eddy current dissipation
Too strong SmCb magnets + aluminum reference mass
Noise level <-> Virgo sensitivity: subject to discussions
Magnetic noise coupling from external perturbations
Solution 1
Ferromagnetic hats proposed for reducing magnetic field
Solution 2 (chosen)
In-place substitution of magnets with smaller ones
Endoscopic procedure with tube, vacuum aspiration of dust etc.
Worked well, except re-gluing of one FS support with “water glass”
=> glitches in WI?
NE magnet substitution =>
No more Eddy current problems expected in Virgo+
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Upgrades during the Virgo+
shutdown
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Virgo+ shutdown
Was scheduled for 3rd of June
May 9th incident => shutdown anticipated by 3 weeks
Required rearrangement of infrastructure works due to need of
clean rooms
Shutdown: Virgo+ packages
High power laser + corresponding optics
New control and DAQ electronics
Environmental noise mitigation
NE tower recovery
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Laser amplifier I
Amplifies 20 W slave laser => 50 (up to 65) W
Integration started 22/05
Old Virgo layout
This part has been removed
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mann
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ILIAS Birmingham, 10/07/2008
Laser amplifier II
Much denser optical setup
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Pre Mode Cleaner
PMC was designed for filtering of technical laser noise at 6 MHz
Also guarantees a good beam shape
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
PMC mechanical scheme
- Triangular zerodur cavity
* avoid thermal control - low mechanical Q
Vacuum tank
- Controlled by 1 piezo
* Corundum half sphere glued on piezo
* Pushing a “telescope spider” shaped support
* 6x12 diam. mirror, glued on spider
-> Avoid piezo bending transfer to mirror displacement)
( simulation by F. Richard)
74mm
- Vacuum tank, Brewster window
Zerodur
Corundum ½ sphere
H. Heit
mann
0.35m
126mm
actuator
Mirror glued on piezo
Front mirrors
Spider
mirror
piezo
Brewster
window
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Glued mirrors
ILIAS Birmingham, 10/07/2008
PMC mounting
PMC on its cradle
PMC tank
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Super-polished optics for avoiding scattered light
Polished by General Optics / coated by LMA, Lyon
To ITF
External injection bench
From laser
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Suspended injection bench
Faraday isolation factor will go down with higher power (therm. lens)
=> insertion of remotely controllable waveplate for isolation improvement
+ compensation plate, if necessary
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Input mode cleaner mirror
Old MC mirror was not good
Too light (80x30 mm)
radiation pressure forces
reference mass suspension
<-> coil cables
Bad optical quality;
backscattering in opposite
direction
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
New MC payload
New MC mirror payload
Heavier (1.4 kg)
Better optical quality
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
Control and DAQ Electronics package
Big change in electronics during shutdown
Obsolete components
Better design (differential ADC inputs,…), lower noise
Better performance (global control speed, more filters,…)
1. DAQ electronics (LAPP, Annecy)
Real time PCs, interconnected with Mux/Demux boards
New ADCs, timing system
Installation ongoing; to be finished during shutdown
2. New DSP for suspension control (Pisa)
Much more powerful (6 DSP on one chip)
Step-by-step installation, in parallel with old system
Install new DAQ system
check that new data is same as old one
Install new global control system
check that new Gc output is the same as old one
Check compatibility of new system with suspension control (DSP)
=> when all tests positive, go to new system
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
H. Heit
mann
STAC/Council
June 2008
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NE/WE Terminal Building
ADC PSD
RIO-B
Camera
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
RT PC
Mx/Dx
Detection Lab
RIO-B
Camera
ADC PSD
RIO-B
Camera
ADC PSD
Platform
ILIAS Birmingham, 10/07/2008
DAQ Room
PR/BS/NI/WI/
SR
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
OB
RT PC
Mx/Dx
Mx/Dx
IB
ADC PSD
RIO-B
Camera
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
RT PC
Mx/Dx
Mx/Mx
Mx/Dx
RT PC
DSP Sc
ADCs
DACs
DSP Sa
RIO-A
Camera
RIO-B
ADC PSD
Mode Cleaner Build.
RT PC
Mx/Dx
Laser Lab
Suspension control
Computing Room
29
H. Heit
mann
Mx/Dx
Platform
RT PC DET
Computing Room
STAC/Council
June 2008
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ILIAS Birmingham, 10/07/2008
30
DAQ Room
OB
Mx/Dx
Mx/Dx
Mx/Dx
PR/BS/NI/WI/
SR
RIO-A Lo:Vb:Qa
DAC
ADC SSFS,IMC
ADC RFC,BMS
RT PC
DSP Sc
ADCs
DACs
DSP Sa
RIO-A
Camera
RIO-B
ADC Coil
ADC PSD
Mode Cleaner Build.
ADC Env,Qt
IB
ADC PSD
ADC Coil
RIO-B
Camera
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
RT PC
Mx/Dx
BMS
RIO-A
DAC
DSP Bc
NE/WE Terminal Building
RT PC ISYS
RT PC CaRT
Detection Lab
Laser Lab
ISYS control
ADC
H. Heit
mann
RT PC DET
Mx/Dx
Computing Room
STAC/Council
June 2008
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Mx/Dx
ADC PSD
ADC Coil
RIO-B
Camera
Platform
ILIAS Birmingham, 10/07/2008
31
RIO-B
Camera
RIO-B
Camera
OB
Mx/Dx
ADC PSD
ADC Coil
PR/BS/NI/WI/
SR
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
ADC PSD
ADC Coil
RT PC
Mx/Dx
Mx/Dx
ADC Q5
ADC Q2
ADC Q1p
Alignment
RIO-A
Lo:Vb:Qa
2 DACs
RT PC
Mx/Dx
Mx/Dx
Mx/Dx
DAQ Room
Mx/Dx
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
RT PC
NE/WE Terminal Building
RIO-B B7Pos
2 Cameras
RIO-A Lo:Vb:Qa
2 DACs
Mx/Dx
Mx/Dx
ADC B1,B1p
ADC B1_2f,B1s
ADC B5,B5_2f
RIO-B1*,B5 Pos
4 Cameras
RIO-A Lo:Vb:Qa
4 DACs
ADC Pi
ADC Mc
RT PC
IB
ADC PSD
ADC Coil
RIO-B
Camera
RIO-A
DSP Sa
DACs
ADCs
DSP Sc
RT PC
Mx/Dx
BMS
RIO-A
DAC
DSP Bc
ADC B7
ADC Q7
RT PC ISYS
RT PC CaRT
RT PC zITF
RT PC tx,tyITF
Calibration
RIO-A
DAC
RIO-A Lo:Vb:Qa
DAC
ADC SSFS,IMC
ADC B2,B2_3f
ADC RFC,BMS
DSP Sc
ADCs
DACs
DSP Sa
RIO-A
Camera
RIO-B
ADC Coil
ADC PSD
Mode Cleaner Build.
ADC Env,Qt
ADC Ph.Cam
ADC SFP,TCS
Detection Lab
Laser Lab
ITF control
Environmental noise reduction
The reduction of the environmental noises is a “never ending
story”
During the shutdown a series of tests and actions is going on
The major ones are
the displacement of the laser lab electronics to a new “EE room”
the displacement of the detection photodiodes under vacuum
H. Heit
mann
‹#›
ILIAS Birmingham, 10/07/2008
The EE (electronics equipment) room
A part of the laser lab electronics racks will go to its own room
Acoustically isolated
Laser chiller has a separate room
EE room
MC
Laser lab
H. Heit
mann
‹#›
ILIAS Birmingham, 10/07/2008
Photodiodes under vacuum
Putting photodiodes under vacuum for reducing environmental noise
coupling through scattered light
•
Photodiodes, the preamplifier, the motors and
supports will go under two
vacuum proof boxes, air
filled (electronics cooling)
H. Heit
mann
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ILIAS Birmingham, 10/07/2008
34
The boxes
Boxes are in steel (3mm thick) and their behavior in vacuum has been
FEM studied at LAPP.
The additional weight should be compliant with a minor retuning of the
suspension
H. Heit
mann
‹#›
ILIAS Birmingham, 10/07/2008
Summary – upgrades already made
Cryotrap installation
For getting rid of “Radio Brewster”
DAQ room airconditioning improvement
For reducing environmental noise
Thermal compensation system
Installed, but laser broken; to be commissioned
Magnet weakening
Results to be seen after restart
H. Heit
mann
‹#›
ILIAS Birmingham, 10/07/2008
Summary - Virgo+ shutdown upgrades
Injection system optics
Laser amplifier – installed, long term observation going on
Pre-Mode cleaner – installed, locked
Low scattering optics on ext. bench - optics delivered
Faraday isolation, remote tuning - to be installed
Mode cleaner curved mirror with marionette+reference mass
Installed: MC has been relocked
Laser lab electronics equipment room
Infrastructure works finished; electronics to be migrated
Photodiodes under vacuum
To be installed after whole ITF has been relocked again
New DAQ electronics
Ongoing; to be finished before relock
New suspension electronics
To be done in a second time
H. Heit
mann
‹#›
ILIAS Birmingham, 10/07/2008
End
Cryotrap: Residual gas analysis
Part. pressure
(mbar)
RGA installed on trap (SR side)
Before (blue) and after (black) the DT opening,
air
and compared to DT (blue)
water
H2
Contamination 1E-10 mbar
H. Heit
mann
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ILIAS Birmingham, 10/07/2008