EM-MSC MSC staus & plans Commissioning meeting

EM-MSC outline VSR1 status post VSR1

EM-MSC 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 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 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 Focus on: improving disturbance rejection

EM-MSC * *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 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 euristic threshold

EM-MSC Learning through misfunctioning… “ghost” disturbance on WI top-stage as a localized wind-like source ( mHz)  rad

EM-MSC Learning through misfunctioning… ITF rms fluctuations with ghost and and quiet weather Small effects: generally the ITF copes even with large corrections due to the ghost

EM-MSC 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 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. ?

EM-MSC Earthquakes Before middle of July unlock due in most cases (90%) to correction saturation After middle of July unlock due to 12 Hz oscillation (50%) and saturation (50%)  SFR+EQG Saturation events roboustness

EM-MSC Earthquakes/H-drops (6.5-mag EQ) Coherent excitation Sismometric ITF response zCorr Saturation fast recover 4-min H recover instead of min without EQG

EM-MSC 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 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.

EM-MSC 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

EM-MSC VSR1-end and pre-Vplus activity

EM-MSC ) 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

EM-MSC ) 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).

EM-MSC )  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 ….

EM-MSC ) 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+

EM-MSC ) 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

EM-MSC  SFR MicroSeism-free Reconstruction …work again on bad-weather impact reduction WEM

EM-MSC 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 ( Hz) 1) differential Lvdt  seism-free available for BS and PR 2) higher crossover frequency allowed! off-line reconstrucion WEM

EM-MSC Using analogic (DAC/ADC) connection between DSPs: tested PR-NI Test during last-week mantenance break: PR reconstruction Confirms the prediction: test of BS reconstruction soon ? In-line test for PR WEM