EM-MSC-100907

MSC staus & plans

Commissioning meeting 10-09-2007

EM-MSC-100907

outline

• VSR1 status

• post VSR1

EM-MSC-100907

Main features of MSC configuration for VSR1

PRE• LC flt roll-off attenuated to improve stability• GIPC of NE-WE (Global Inverted Pendulum Control)• 4-MARIO lock re-allocation• Q-coupling compensation (F7 and MARIO)

DURING• NI-WI LVDT/ACC : anti-Wind => anti-Sea => anti-Wind (Jun 5)• NE-WE V DC position readjusted (1mm)

(June 19) • BS LC tuning to improve regions with small phase margin (Jul 4)• MARIO lock re-allocation on NI-WI OFF (NE,WE only) (Jun 6)•Seism-Free Reconstruction of PR top stage Err Signal (Jul 6)• EQG Guardian to disable GIPC in case of EarthQuake (Jul mid)• NI-WI re-centring on beam

(Jul 12-17)

EM-MSC-100907

Essentials of the present MSC during VSR1

GIPC & SFR (both are partial): to make higher Poc/Acc sensor blending crossover frequency without significant Seism re-injection.

EQG: GIPC does not combine Acc => EQG disables GIPC in case of Earthquakes (coherent for far EQs).

But… note: I) summer ! II) sensitivity worse up to 40 times at low frequency !

Control Noise: no evidence of noise significantly limiting present Virgo sensitivity.

Compensation of actuator non-linear recoil: for both MARIO and SA

EM-MSC-100907

MSC targets before passing to V+

Improving disturbance rejection:

I) O-B-O tests to check disturbance entry-points (impact on Horizon).

II) Completion of SFR and GIPC will significantly improve Stormy weather and Earthquake rejection.

note: stable ITF operation is required!Actuator Eddy Current limit is reacheable through new CD (new driving strategies?) and easy improvements of Alignment control.note: stable ITF operation is required!

Once done: Hardware (mechanical) checks (ALL_TW): during V+ detector integration;standalone

MSC Control Noise:

EM-MSC-100907

Focus on: improving disturbance rejection

EM-MSC-100907

8.5*0.4348-0.3*0.4348* V1:Sa_NE_F0_xLvdt_50Hz_rms_0.03_0.1Hz-0.6*0.4348* V1:Sa_NE_F0_xLvdt_50Hz_rms_0.22_1Hz

€

HNSNS _ aveheu = 3.6958 −0.1304 ⋅W rms −0.2609 ⋅μS rms

€

[HNSNS _ aveheu ] = Mpc

[W rms] = [μS rms] = μm

Heuristic dependence on weather conditions

- effects related to the sea more relevant than those due to the wind;- overall coupling is weighted by other parameters of the ITF.

Mpc

MSC tuning

euristicthreshold

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Learning through misfunctioning…

“ghost” disturbance on WI top-stage as a localized wind-like source (30-100 mHz)

rad

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Learning through misfunctioning…

ITF rms fluctuationswith ghost and and quiet weather

Small effects:generally the ITFcopes even with largecorrections due to the ghost

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Learning through misfunctioning…

“ghost” disturbance on WI top-stage: attempt of extracting thresholded effects.

Hardly correlated to such kind of WI-like source:

zM ~ 2 V produces some effects on DF, but they are smaller than usual 10% Horizon fluctuations

EM-MSC-100907

Learning through misfunctioning…

“ghost” disturbance on WI top-stage: attempt of extracting thresholded effects.

The result is consistent with real-wind effects

Note: only 4 marionette data availabe for wind&no-sea

IN VSR1 conditions the wind issue for the suspension system was not crucial.

?

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Earthquakes

1

10

100

1000

0 20 40 60 80 100 120

EQ1LOCKEDLOCKED THROUGH EQGUNLOCK

day

Before middle of July unlock due in most cases (90%) to correction saturationAfter middle of July unlock due to 12 Hz oscillation (50%) and saturation (50%)

SFR+EQG

Saturation events roboustness

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Earthquakes/H-drops (6.5-mag EQ)Coherent excitation

SismometricITF response

zCorr Saturation

fast recover

4-min H recover instead of 30-40 min without EQG

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Sub-conclusion

Partial GIPC(ARMs)

Partial SFR(Central Area)

EQG GUARD(patch)

higher cross-over f:lower wind noise

without seism inj.

Operation strategies involving suspension operation as-a-whole improve disturbance rejection capability.

GUARD macros can be effectively used for environmentally-featured configurations to improve and make more roboust the system.

EM-MSC-100907

Sub-conclusion

GIPC(ARMs)

SFR(Central Area)

ENV-TUNED GUARD

higher cross-over f:lower wind noise

without seism inj.

Operation strategies involving suspension operation as-a-whole improve disturbance rejection capability.

GUARD macros can be effectively used for environmentally-featured configurations to improve and make more roboust the system.

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GIPC (Global IP Control) + SFR (SeismFreeReconstruction)GIPC:

zGC is not crucially affected by Seism (referred to suspended mirror)

deduced from GC zCorr

SFR:Sseism is coherent in the central area and reconstructed signals are free from it.

reconstructed by local DSP

GC

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VSR1-end and pre-Vplus activity

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1) 5-30 Sept: commissioning breaks (light actions)

Beam centering: H-offset on BS is probably rather large; it should be checked for all the mirrors and it a crucial issue for the VSR1 noise characterization (the campaign started on 05/Sept).

Accelerometer recombination test (Input=>End suspension): meant to complete “GIPC” for the cavities (now we use differential position and recombine it with local acceleration => we need EQGuard); very precious data in case of EQ (~1/week) (A. Gennai is arranging the set-up: probably ready by the next mantenance 12/Sept).

Note: only crate switch Off-On to allow the installation of two DOL on NI-WI VSBs

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2) 1-15 Oct: investigation&characterization

2.1) Detailed measurement of F7-mirror TF aimed to H-reconstruction: TF measurements injecting noise at MARIO and Mirror stages and using ITF readout (one shift).

2.3) GIPC: in-line implementation of complete GIPC.

2.2) tests in quiet environmental conditions: O-B-O noise injections to investigate the likeage of wind and sea disturbance in VSR1 configuration (heuristic formula to predict horizon).

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2.4) Seism-Free-Reconstruction: use of the II S-link to reconstruct BS and PR differential top-stage signals at DSP level (now we use DAD conversion to do SFR for PR suspension).

great relevance for :

- suspension configuration during the winter and for the future;

- better robusteness during EQ;

- new options to improve suspension control (sensor-blending at least);

- Virgo paper ….

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3.1) Short TW, IB, Vertical-control: IB V-control implementation should be integrated with AA improvement (done by ISYS and AA people).

Time: 1 W. Note: only SW actions.

3.2) Short TW, MC, Vertical-control: V-control and IP tuning involve HW

- V-control => one accelerometer out of order

- IP is now too rigid because MC payload is light => add mass

Time: 1 W+3 days ITF operation check

3.3) F7 sensor noise: investigations (electronics ? …. dedicated tests… )

for V+ we should exploit the availability of F7 control handle

Time : ??

3.4) LC HW mantenance: laser-diode replacements etc…

Time : few days

3) 16 Oct-15 Jan08: toward V+

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4.1) NINE-WIWE: IP re-tuning after payload installations required

Time : to be defined in the context of V+ detector scheduling

4) Reccommended in V+ detector context

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SFR

MicroSeism-free Reconstruction

…work again on bad-weather impact reduction

WEM-200607

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The method: reconstruction of BS and PR zLVDT upon the basis of NI and WI zLvdt

consistency

check using

actual zCorr

TH: suspensions in the central BLD are coherently excited by microseism (0.1-0.5 Hz)

1) differential Lvdt seism-free available for BS and PR2) higher crossover frequency allowed!

off-line reconstrucion

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Using analogic (DAC/ADC) connection between DSPs: tested PR-NI

Test during last-week mantenance break: PR reconstruction

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Confirms the prediction: test of BS reconstruction soon ?

In-line test for PR

WEM-200607