status of the virgo commissioning g.losurdo – infn firenze/urbino for the virgo collaboration
TRANSCRIPT
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 2
Since last meeting…
‘Jumps’ disappeared
Two runs:– C6 run: 29 Jul-12 Aug – C7 run: 14-19 Sep
Big improvement in stability and sensitivity
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 6
Actions before C6
IB aligned on the position of May 19-26 (when no jumps were present). No more changes since then (except ABP offset during C6)
B2_3f phase detuned by 75° from “optimal” phase Photodiode centering
Jumps disappeared
NE autoalignment using B1p (HH talk) Alignment drift control Improvement of SSFS loop
ITF more stable
‘ technique’ implemented
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 7
Laser0
+
-
Control of the differential mode
B5
BS
B5_ACp
B5_ACq
B1_ACp
B2_3f_ACp
Subtraction of BS control noise by the correction sent to the end mirrors
+
-
” technique”
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 8
Actions during C6
C6 sensitivity has been improved twice:
Spurious beam damped on NE bench
Change of power stabilization setup (use error signal after MC)
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 9
0 5 10 14days
Recycling cavity power
C6
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 10
C6 vs C5
(PR pwr *BS_AR)/(injected pwr*10)
C5 (no drift control)
C6 (drift control)
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 11
Duration: 336h
Locking: 89.3%
Science mode: 86.2%
C6 Duty cycle
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 14
C6 inspiral range
04/08(15:00 LT):
spurious beams damped on NE bench
04/08(15:00 LT):
spurious beams damped on NE bench
10/08 (14:00LT):
laser beam re-aligned on the IMC
10/08 (14:00LT):
laser beam re-aligned on the IMC
11/08 (15:30LT):
laser power stabilization reconfigured
11/08 (15:30LT):
laser power stabilization reconfigured
GPS: 807818236 ( 297kPc)
GPS: 807842186 ( 300kPc)
GPS: 807818236 ( 297kPc)
GPS: 807842186 ( 300kPc)
04/08(15:00 LT):
spurious beams damped on NE bench
04/08(15:00 LT):
spurious beams damped on NE bench
10/08 (14:00LT):
laser beam re-aligned on the IMC
10/08 (14:00LT):
laser beam re-aligned on the IMC
11/08 (15:30LT):
laser power stabilization reconfigured
11/08 (15:30LT):
laser power stabilization reconfigured
GPS: 807818236 ( 297kPc)
GPS: 807842186 ( 300kPc)
GPS: 807818236 ( 297kPc)
GPS: 807842186 ( 300kPc)
04/08(15:00 LT):
spurious beams damped on NE bench
04/08(15:00 LT):
spurious beams damped on NE bench
10/08 (14:00LT):
laser beam re-aligned on the IMC
10/08 (14:00LT):
laser beam re-aligned on the IMC
11/08 (15:30LT):
laser power stabilization reconfigured
11/08 (15:30LT):
laser power stabilization reconfigured
GPS: 807818236 ( 297kPc)
GPS: 807842186 ( 300kPc)
GPS: 807818236 ( 297kPc)
GPS: 807842186 ( 300kPc)
0.14
0.42
0.28
Best range: 0.4 Mpc
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 15
Improvements during C6
Sensitivity from Jul 29 Sensitivity from Aug 12
Suppression of the non stationary
bumpPower noise
reduction
• Improvement of B1 optical gain (better alignment conditions ?)
• B1 electronic noise reduced by 2 (all the power sent to only one photodiode)
• Slight reduction of frequency noise (alignment ?)
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 16
Stray light
Stray beams in the NE external bench.
3 dumped, the bump disappeared !
Effect of stray beams dumping on B1_ACp RMS (in the bump region)
Coherence of dark fringe and NE bench photodiode:before and after dumping
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 17
Mode Cleaner transmission
Power stabilisation loopJuly 29 : Sensitivity limited by power noise due to beam jitter before the IMC
Improvement of the beam alignment on the IMC
Improvement of the power stabilisation loop (error signal taken after the IMC)
End of the run : the coherence between B1 & angular error signals of MC mirror disappears.
Jul 29 Vs Aug 12
Power noise
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 20
Actions after C6
10 AA loops closed (HH talk)
Full hierarchical control implemented
New B5 setup (more power on B5, less frequency noise)
Tidal control on BS
Coil driver upgraded to reduce DAC noise
New PR control filter
Important achievements:
Anderson technique demonstrated
SA control design demonstrated
ITF left locked during night !
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 21
Frequency noise limits the sensitivity above 1kHz It is due to B5_d1 shot+electronic noise which is introduced by the SSFS This noise can be reduced if a bigger fraction of B5 is sent to B5_d1
Sensitivity Aug 12thB1 shot noise
B1 elec noiseFrequency noiseIncoherent sum
Frequency noise
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 22
B5 setup modification
50 %
2f
50 %
Data in WPr_B5_DC,AC
d1
d2
50 %
50 %
90 %
quadrants10 %
Data in WPr_B5_2f
10 %
2f
90 %
Data in WPr_B5_DC,AC
d1
d2
90 %
10 %
95 %
quadrants5 %
Data in WPr_B5_2f
Old setup New setup
Now B5_d2 is used for SSFS, with 3 times more power (80% instead of 25%) Expected reduction of the frequency noise by a factor 2
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 23
B5 electronic and shot noise converted into a laser frequency noise by the SSFS loop
New optical setup : the SSFS error signal receives 3 times more power
Laser frequency noise should be decreased by 2 wrt C6
- B1_ACp, end of C6- B1_ACp, Aug 23 (new setup)- Shot + electronic noise- Electronic noise
Edwige Tournefier Aug 27
Laser frequency noise has been reduced but coherence with B1 still visible
Laser
0B5_ACp
Laser frequency control loop (SSFS)
B5: results
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 24
DAC noise
“Simple” DAC noise estimation does not explain the noise (50-150 Hz) in the 27 Aug sensitivity
DAC noise larger when correction applied
R.Gouaty
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 26
zCorr reduction
Marionette/RM crossover @5 Hz
After reallocation zCorr rms reduced by 100
Without marionette700 nm rms
With marionette7 nm rms
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 27
Automation
5 mins
Lock to DF variable finesse
AA ONOMC lock
MarionetteLow noise CD
techniqueLines ON
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 28
M9 – Aug 25
Marionette +NE/WE coil driver upgrade
New PR filter
New B5 setup
Turbo pump DETswitched OFF
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 29
BS DAC noise
BS DAC noise limits the sensitivity
Reduction of coil driver gain requires tidal control
Tidal control required!
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 30
M9 inspiral range
0.2
0.4
0.6MPc
Best range: 0.6 Mpc
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 31
Reliability
ITF stayed locked for 28 hrs with 10 dof AA ON, full hierarchical control, tidal control on BS
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 32
After M9
BS coil driver upgrade
Low gain LC
Aug 27
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 33
27 Aug inspiral range
0.6
0.8
0.7
Best range: 0.85 MpcMpc
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 34
Non stationarity
Probably due to diffused light on the end benches
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 35
Sensitivity from Aug 12 (End of C6)
Sensitivity from Aug 27Improvement due to Linear Alignment (4 loops closed
instead of 2)
DAC noise reduction
PR z control noise reduction (Neo
filter with roll-off @ 100 Hz)
BS z control noise : alpha tuning
New optical setup for B5 Reduction of laser frequency noise
2kHz bump due to detection tower pump (exciting external bench resonances)
August summary
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 36
Modulation depth
Modulation depth has been increased by a factor 2 (now m = 0.3)
PRCL control noise reduction expected
Tuning of the locking parameters needed
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 38
C7 run
Many new features:– AA– Hierarchical control– Tidal control on BS– Coil driver upgraded– New B5 setup– Modulation depth increased
We decided to make a short run (5 days) before shutdown
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 40
C7 inspiral range
Best range: 1.65 Mpc
ILIAS WG1 – Perugia, September 19, 2005 G.Losurdo – INFN Firenze-Urbino 41
C7 duty cycle
Locked: 70%Science mode: 64%