Post on 05-Jan-2016
description
transcript
Present SA performance vs. AdV & ET Specs
S.Braccini for Virgo Suspension group
Passive Attenuation
Ground
Mirror
Resonances
f-2N
Long Pendula
2 Hz
Tran
smis
sion
Soft Springs
Frequency (Hz)
Blade Springs
MagneticAntisprings
8 m
Ground Seismic NoiseMirror Seismic Noise
Rumore Termico
DL(f) = h(f) / 3000
TFmax = DL(f) /(LSD Ground Seismic Noise)
LSD Ground Seismic Noise = 5 x 10 -7/ f 2
Same Exercise for ET sensitivity
DL(f) = h(f) / 10000
TFmax = DL(f) /(LSD Under-Ground Seismic Noise)
LSD Ground Seismic Noise (Kamioka) - 5 x 10 -9/ f 2
(Duzel Mine much better)
Same Exercise for ET-Xylophone sensitivity
DL(f) = h(f) / 10000
TFmax = DL(f) /(LSD Ground Seismic Noise)
LSD Ground Seismic Noise (Kamioka) - 5 x 10 -9/ f 2
Valid both for horizontal and vertical seismic noise
SA designe freccette
Filter Chain TF measurements(without Pre-Isolator !)
SA designe freccette
@ 4.1 Hz< 6 ×10e-8
CITF Measurements around 2, 4, 9 Hz
SA designe freccette
CITF Measurements around 2, 4, 9 Hz
@ 2.25 Hz5 ×10e-6
High Sens Range
Larger stabilityallows longer measurements
SA designe freccette
frequency (Hz)
Displacement (m .Hz-1/2)
Top
Mirror
Transfer Function < 10-10
StressedMeasurement
T = 41943 sHigh Sens Range
TOP
MIRROR
2 x 10-18 m Hz-1/2
1.2 x 10-6 m Hz-1/2
TF < 1.7 x 10-12
!!
TF = 1.26 x 10-11
ET-Xylophone AdV
1.26 x 10-11
+ Pre-Isolator
SA designe freccette
X-excitation
SA designe freccette
Possible Bypass
Bypass Indication ?
X - Excitation Results
HORIZONTAL
Integration Time Kind of Measurement FrequencyDisp Top
(Lines LSD) Disp Mirror Upper Limit (LSD) TF(s) (Hz) (m Hz^-1/2) (m Hz^-1/2)
10485 Central interferometer 2,30 4,80E-05 2,50E-10 5,21E-0610485 Central interferometer 4,10 3,30E-05 2,00E-12 6,06E-08
About 20000 s West Input Cavity Mirror 4,30 4,31E-06 3,6E-14 8,36E-09About 20000 s West Input Cavity Mirror 6,30 6,02E-06 5,4E-14 8,97E-09
10485 Central interferometer 9,80 5,70E-06 4,10E-13 7,19E-08About 20000 s West Input Cavity Mirror 10,30 3,00E-06 1,8E-16 6,00E-11About 20000 s West Input Cavity Mirror 18,30 2,85E-06 4,8E-17 1,68E-11
41943 North Input Cavity Mirror 29,30 2,95E-06 1,50E-17 5,08E-1241943 West Input Cavity Mirror 30,30 9,39E-07 6,00E-17 6,39E-1141943 North End Cavity Mirror 31,30 1,42E-06 1,80E-17 1,26E-1141943 West End Cavity Mirror 32,30 1,22E-06 2,4E-18 1,97E-12
VERTICALIncluded H-V Coupling
Integration Time Kind of Measurement FrequencyDisp Top
(Lines LSD) Disp Mirror Upper Limit (LSD) TF(s) (Hz) (m Hz^-1/2) (m Hz^-1/2)
2620 Central Interferometer 2,25 1,70E-04 2,60E-10 1,53E-062620 Central Interferometer 4,10 3,00E-04 3,00E-12 1,00E-08
25165 North Input Cavity Mirror 29,30 1,22E-06 3,00E-18 2,47E-1225165 West Input Cavity Mirror 30,30 3,88E-06 3,00E-18 7,73E-1325165 North End Cavity Mirror 31,30 4,14E-06 3,00E-18 7,24E-1325165 West End Cavity Mirror 32,30 4,43E-06 3,00E-18 6,77E-13
X-AXIS8388 North Input Cavity Mirror 29,30 1,18E-06 3,9E-17 3,30E-118388 West Input Cavity Mirror 30,30 6,08E-07 1,26E-17 2,07E-118388 North End Cavity Mirror 31,30 6,3E-07 3,9E-18 6,19E-128388 West End Cavity Mirror 32,30 7,53E-07 2,31E-17 3,07E-11
Red = Line DetectedBlue = Line Not Detected
Purple = Upper Limitnot useful (too large)
ET-Xylophone AdV
Upper Limit Detected
Without Pre-Isolator (Just filter chain !)
53113
IP Guarantees for this !Already compliant for ET
(Remind that we are speaking of Upper Limits !)
Vertical TF measurements(Coupling included in the measurement)
Vertical Measurements
ET-Xylophone AdV
Without Filter Zero (Just filter chain !)
60
F0 Guarantees for thisUPPER LIMIT (!) compliant for ET
Vertical Upper Limit Vertical Detected
Preisolator makes safetymargin wide in AdV
SA are compliant also for ET starting from 4 Hz....
What happens below?
@ 2.25 Hz5 ×10e-6
Remarkable Attenuation also at 2.25 Hz
HORIZONTAL
@ 2.25 Hz1.5 ×10e-6
Remarkable Attenuation also at 2.25 Hz
VERTICAL
Yes
No
Maybe
423
TF
f
ModelMeas.
Stage by Stage Measurement (and Model)
ET Design Programme
Cut-off 3-4 Hz No Design Study
Cut-off 1-2 Hz Design Study
SCIENCE CASE & NEWTONIAN NOISETO BE DISCUSSED AT ERICE MEETING
N 1 Hz 2 Hz ------------------------- {3, 1.6*10-7, 5.4*10-10} {4, 4.8*10-8, 3.3*10-11} {5, 2.6*10-8, 3.4*10-12} {6, 2.3*10-8, 6.7*10-12} {7, 2.1*10-8, 2.6*10-12}
Optimized at 1Hz
Courtesy G. Cella
Horizontal
~50 m
G.Cella
2 Independent full simulations in progress
Actuation Noise
Bobina
MagneteVV
-0.2
0.2
V
Lunghezza cavità
V
-0.2
0.2
l/100
Locking
M
GiuntoFlessibile
g
30 mHz
PendoloInvertito
ADC DSP DAC
Actuators
Accelerometers
RESIDUAL SWING < 0.1 mm
CPU
PPC
Motor
Driver
Dual
Port
RAM
DAC-D-
ADC-D-
DSP-D-
DSP-L-
Timing
DOL DAC-L-
DAC-L-
Dual
Port
RAM
ADC-D-
ADC-D-
VME bus
VSB bus 1 VBeX bus 1 VSB bus 2
VBeX bus 2
Superattenuatore
Sensors
Coil Drivers
Motors
Sensors
Sensors
Coil Drivers
Coil Drivers
Position &
Damping
DSP:- 96 bit- 60 MFLOPs
DAC:- 8 Chan.- 20 bit- 500 KHz
ADC:- 8 Chan.- 16 bit
SAR- 200 KHz
Acc. Sens:- 10-9 m/s2
- 0 – 100Hz- f.s. 1g
Control Electronics System
Hierarchical Control
WIND SEAMIRROR
ACTUATION
Tilt
Direct Measurement on the ITF !!
A.Gennai (VIR 029-A09)
Distribution and (its integral) of the maximum of the absolute values of marionettacorrection voltage computed on 200 s-long interval
(all VSR1 run, itf in science mode)
Calm Any
Calm Any
Setting the marionetta actuation range to 2.2 V we “risk” 1% of duty cycle(techical solutions to avoid unlocks available)
Calm Any
Actuation Noise Reduction by
a factor 4 immediatelyavailable !
Reduction factor
3-4 Wind (5%)
7-8 Calm (95%)
Direct Meas. Now
Calm
Wind
AdV
Many other possibility to reduce noise
AdV: SA performance are compliant with AdVboth for passive isolation and actuation noise
ET: Safety margin guarantees present SA attenuation goodalso for the ET project (not too demanding above a few Hz)
Passive isolation compliant above about 3-4 HzOptimization necessary if lower frequency will be investigated
Actuation Noise is the major concern
AdV: Upgrades provide additional safety margin.......
Recent upgrades (each requiring a separate talk)
Gyrolaser: A.Di Virgilio’s group provided an instrument able to monitor ground tilt with the required sensitivity (close to 10-9 rad/Hz1/2) with high duty cycle.
Tiltmeters: The flex-joint solution was killed. A new prototype concevied by A.Giazotto based on a complete different design was assembled (excellent mechanical performance).
Piezo Actuation: The entire electro-mechanical system was assembled by F.Frasconi on SAFE bottom ring and monitored by LVDT. Preliminary tests are very encouraging.
Vertical to Horizontal Coupling: The MSC group measured the coupling factor exciting marionetta in vertical and looking at the itf with a “surprising result” (TBC).