1 ILIAS Birmingham, 10/07/2008H. Heit mann
The Virgo+ shutdownThe Virgo+ shutdown
2 ILIAS Birmingham, 10/07/2008H. Heit mann
Performances before V+ shutdownPerformances before V+ shutdown
3 ILIAS Birmingham, 10/07/2008H. Heit mann
Virgo progressVirgo progress
4 ILIAS Birmingham, 10/07/2008H. Heit mann
Virgo sensitivity: May 2008Virgo sensitivity: May 2008
Spikes: relaxation of magnet waterglass glueing
5 ILIAS Birmingham, 10/07/2008H. Heit mann
Recent upgradesRecent upgrades
6 ILIAS Birmingham, 10/07/2008H. Heit mann
The cryotrapThe 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 afterwardsNice success of the vacuum group
Detectiontower
Signal recycling
To e
xt.
dete
ctio
n b
ench
7 ILIAS Birmingham, 10/07/2008H. Heit mann
Cryotrap functioningCryotrap functioning
Duration of functioning 3 days
Refilling takes 1 hour
Project of increasing functioning time to >= 1 weekBefore the next science run
8 ILIAS Birmingham, 10/07/2008H. Heit mann
DAQ room air conditioning upgradeDAQ 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
AC ONAC OFF
Central hall AC Water pump of CECleanRooms AC Laser lab
DAQ room (+CE hall)
North End AC
9 ILIAS Birmingham, 10/07/2008H. Heit mann
DAQ room air conditioning upgradeDAQ room air conditioning upgrade
Acoustic isolation of the DAQ
=> reduce noise in central area
430
UTA
120
200
70
32
90
60 232.5
119
301
137.5
157
233.
5
AC
SR DT DT lab
New AC system outside DAQ
Microphone sees a noise reduction wrt. to the previous situation.
beforeafterAC offHz
10 ILIAS Birmingham, 10/07/2008H. Heit mann
Thermal compensation systemThermal compensation system
Thermal lensing in the input mirrors has had a strong impact on commissioning
Complicated locking procedure for surviving thermal transientBistabilities arise during transitionBe 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 neededCO2 laser ring system designed and realized by Roma Tor Vergata
group with support by EGO
11 ILIAS Birmingham, 10/07/2008H. Heit mann
TCS layoutTCS layout
Electronics
Chiller
12 ILIAS Birmingham, 10/07/2008H. Heit mann
L4
2" Hot mirrorL2M
AXICON
L1
L8L7
LASY-20S
Aiming laser
Beam splitter
Beam splitter
Power meter
Polarizer
Half waveplate
Beam dump
AOM
TCS optical layoutTCS optical layout
13 ILIAS Birmingham, 10/07/2008H. Heit mann
TCS in-vacuum opticsTCS in-vacuum optics
In vacuum steering mirrors needed
14 ILIAS Birmingham, 10/07/2008H. Heit mann
TCS in-vacuum opticsTCS in-vacuum optics
In vacuum steering mirrors needed
15 ILIAS Birmingham, 10/07/2008H. Heit mann
TCS statusTCS status
CO2 laser problemsOne of the two lasers arrived broken from the company (Access Laser)Sent back but delivered again out of order
Probably an undetected CO2 gas leakageSent back to the company a second time
WI TCS commissioning startedStill many things to be learned, but:First encouraging results (see Enrico’s talk)
To be donePower stabilization to be realized in the next monthsCentral spot needed for reducing thermal transient time?Continue commissioning as soon as interferometer available again
16 ILIAS Birmingham, 10/07/2008H. Heit mann
The Eddy current issueThe Eddy current issue
Increase of thermal noise due to Eddy current dissipationToo strong SmCb magnets + aluminum reference massNoise level <-> Virgo sensitivity: subject to discussions
Magnetic noise coupling from external perturbations
Solution 1Ferromagnetic hats proposed for reducing magnetic field
Solution 2 (chosen)In-place substitution of magnets with smaller onesEndoscopic 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+
17 ILIAS Birmingham, 10/07/2008H. Heit mann
Upgrades during the Virgo+ Upgrades during the Virgo+ shutdownshutdown
18 ILIAS Birmingham, 10/07/2008H. Heit mann
Virgo+ shutdownVirgo+ shutdown
Was scheduled for 3rd of JuneMay 9th incident => shutdown anticipated by 3 weeksRequired rearrangement of infrastructure works due to need of
clean rooms
Shutdown: Virgo+ packagesHigh power laser + corresponding opticsNew control and DAQ electronicsEnvironmental noise mitigationNE tower recovery
19 ILIAS Birmingham, 10/07/2008H. Heit mann
Laser amplifier ILaser amplifier I
Amplifies 20 W slave laser => 50 (up to 65) WIntegration started 22/05
Old Virgo layout
This part has been removed
20 ILIAS Birmingham, 10/07/2008H. Heit mann
Laser amplifier IILaser amplifier II
Much denser optical setup
21 ILIAS Birmingham, 10/07/2008H. Heit mann
Pre Mode CleanerPre Mode Cleaner
PMC was designed for filtering of technical laser noise at 6 MHzAlso guarantees a good beam shape
22 ILIAS Birmingham, 10/07/2008H. Heit mann
mirror
piezoCorundum ½ sphere
SpiderZeroduractuator
Brewster window
Front mirrors
Vacuum tank
0.35m
- Triangular zerodur cavity * avoid thermal control - low mechanical Q
- 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)
- Vacuum tank, Brewster window
126m
m
74mm
Glued mirrors
Mirror glued on piezo
PMC mechanical schemePMC mechanical scheme
23 ILIAS Birmingham, 10/07/2008H. Heit mann
PMC on its cradle
PMC tank
PMC mountingPMC mounting
24 ILIAS Birmingham, 10/07/2008H. Heit mann
External injection benchExternal injection bench
Super-polished optics for avoiding scattered lightPolished by General Optics / coated by LMA, Lyon
From laser
To ITF
25 ILIAS Birmingham, 10/07/2008H. Heit mann
Suspended injection benchSuspended 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
26 ILIAS Birmingham, 10/07/2008H. Heit mann
Input mode cleaner mirrorInput mode cleaner mirrorOld MC mirror was not good
Too light (80x30 mm)radiation
pressure forces
reference mass suspension <-> coil cables
Bad optical quality;backscattering in opposite
direction
27 ILIAS Birmingham, 10/07/2008H. Heit mann
New MC payloadNew MC payload
New MC mirror payloadHeavier (1.4 kg)Better optical quality
28 ILIAS Birmingham, 10/07/2008H. Heit mann
Control and DAQ Electronics packageControl and DAQ Electronics package
Big change in electronics during shutdownObsolete componentsBetter design (differential ADC inputs,…), lower noiseBetter performance (global control speed, more filters,…)
1. DAQ electronics (LAPP, Annecy)Real time PCs, interconnected with Mux/Demux boardsNew ADCs, timing systemInstallation 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 systemInstall new DAQ system
check that new data is same as old oneInstall new global control system
check that new Gc output is the same as old oneCheck compatibility of new system with suspension control (DSP)
=> when all tests positive, go to new system
29 ILIAS Birmingham, 10/07/2008H. Heit mann
Suspension controlSuspension control
STAC/Council June 2008 29
Computing Room
Mx/
Dx
RIO
-B
DSP
Sc
DSP
Sa
ADC
PSD
Platform
RT P
C
RIO
-A
Mx/
Mx
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
RT P
C
RIO
-A
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
RT P
C
RIO
-A
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
RT P
C
RIO
-A
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
RT P
C
RIO
-A
Cam
era
Cam
era
Cam
era
Cam
era
Cam
era
DAC
s
DAC
sD
ACs
DAC
sD
ACs
AD
Cs
AD
Cs A
DCs
AD
Cs A
DCs
Mx/
Dx
30 ILIAS Birmingham, 10/07/2008H. Heit mann
ISYS controlISYS control
STAC/Council June 2008 30
Computing Room
Mx/
Dx
RIO
-B
DSP
Sc
DSP
Sa
ADC
Coil
ADC
PSD
Platform
RT P
C
RIO
-A
ADC Env,Qt
ADC
SSFS
,IMC
ADC
RFC,
BMS
RIO
-A L
o:Vb
:Qa
RT P
C Ca
RTRT
PC
ISYS
RT PC DETM
x/D
x
Mx/
Dx
Mx/
Dx
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
ADC
Coil
RT P
C
RIO
-A
Cam
era
RIO-A
DSP Bc
BMS
DACCam
era
DAC
s
DAC
s
DAC
AD
Cs
AD
Cs
31 ILIAS Birmingham, 10/07/2008H. Heit mann
ITF controlITF control
STAC/Council June 2008 31
Computing Room
Mx/
Dx
RIO
-B
DSP
Sc
DSP
Sa
ADC
Coil
ADC
PSD
Platform
RT P
C
RIO
-A
Mx/Dx
RIO
-A L
o:Vb
:Qa
RIO
-B B
7Pos
ADC
B7AD
C Q
7
ADC Env,Qt
ADC
B2,B
2_3f
ADC
SSFS
,IMC
ADC
RFC,
BMS
RIO
-A L
o:Vb
:Qa
ADC
PiAD
C M
c
ADC
B1,B
1pAD
C B1
_2f,B
1sAD
C B5
,B5_
2fRT
PC
CaRT
RT P
C IS
YS
RT P
C tx
,tyIT
FRT
PC
zITF
RT PC DETM
x/D
x
Mx/
Dx
Mx/
Dx
Mx/
Dx
Mx/
Dx
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
ADC
Coil
RT P
C
RIO
-A
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
ADC
Coil
RT P
C
RIO
-A
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
ADC
Coil
RT P
C
RIO
-A
Mx/
Dx
DSP
Sa
DSP
Sc
RIO
-B
ADC
PSD
ADC
Coil
RT P
C
RIO
-A
ADC
Q5
ADC
Q2
ADC
Q1p
RIO-ACalibration
ADC Mx/Dx
Cam
era
Cam
era
Cam
era
Cam
era
RIO-A
DSP Bc
BMS
DACCam
era
DAC
s
DAC
sD
ACs
DAC
sD
ACs
DAC
DAC
2 Ca
mer
as
2 D
ACs
RIO
-B1*
,B5
Pos
4 Ca
mer
as
RIO
-A L
o:Vb
:Qa
4 D
ACs
RIO
-A
Lo:V
b:Q
a2
DAC
s
AD
Cs
AD
Cs A
DCs
AD
Cs A
DCs
ADC
SFP,
TCS
ADC
Ph.C
am
32 ILIAS Birmingham, 10/07/2008H. Heit mann
Environmental noise reductionEnvironmental 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 arethe displacement of the laser lab electronics to a new “EE room”the displacement of the detection photodiodes under vacuum
33 ILIAS Birmingham, 10/07/2008H. Heit mann
The EE (electronics equipment) roomThe EE (electronics equipment) room
A part of the laser lab electronics racks will go to its own roomAcoustically isolatedLaser chiller has a separate room
Laser lab
EE room
MC
34 ILIAS Birmingham, 10/07/2008H. Heit mann
Photodiodes under vacuumPhotodiodes under vacuum
34
• Photodiodes, the pre-amplifier, the motors and supports will go under two vacuum proof boxes, air filled (electronics cooling)
Putting photodiodes under vacuum for reducing environmental noise coupling through scattered light
35 ILIAS Birmingham, 10/07/2008H. Heit mann
The boxesThe boxesBoxes 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
36 ILIAS Birmingham, 10/07/2008H. Heit mann
Summary – upgrades already madeSummary – upgrades already made
Cryotrap installationFor getting rid of “Radio Brewster”
DAQ room airconditioning improvementFor reducing environmental noise
Thermal compensation system Installed, but laser broken; to be commissioned
Magnet weakeningResults to be seen after restart
37 ILIAS Birmingham, 10/07/2008H. Heit mann
Summary - Virgo+ shutdown upgradesSummary - Virgo+ shutdown upgrades
Injection system opticsLaser amplifier – installed, long term observation going onPre-Mode cleaner – installed, lockedLow scattering optics on ext. bench - optics deliveredFaraday isolation, remote tuning - to be installed
Mode cleaner curved mirror with marionette+reference massInstalled: MC has been relocked
Laser lab electronics equipment roomInfrastructure works finished; electronics to be migrated
Photodiodes under vacuumTo be installed after whole ITF has been relocked again
New DAQ electronicsOngoing; to be finished before relock
New suspension electronicsTo be done in a second time
End
39 ILIAS Birmingham, 10/07/2008H. Heit mann
Cryotrap: Residual gas analysisCryotrap: Residual gas analysisRGA installed on trap (SR side) Before (blue) and after (black) the DT opening, and compared to DT (blue)
air
H2
water
Contamination 1E-10 mbar
Part. pressure (mbar)