present superatttenuator performance vs. adv & et requirements s.braccini for virgo suspension...
TRANSCRIPT
Present Superatttenuator performance vs.
AdV & ET Requirements
S.Braccini for Virgo Suspension group
TFmax = DL(f) /(LSD Under-Ground Seismic Noise)
LSD Ground Seismic Noise (Kamioka) - 5 x 10 -9/ f 2
(Duzel Mine much better)
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
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”
ET-Xylophone AdV
Without Filter Zero (Just filter chain !)
60
F0 Guarantees for thisUPPER LIMIT (!) compliant for ET
Vertical Upper Limit Vertical Detected
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
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
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)
Setting the marionetta actuation range to 2.2 V we “risk” 1% of duty cycle
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
Recent upgrades
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).
AdV: SA performance are compliant with AdVboth for passive isolation and actuation noise
ET: Present SA attenuation good also for the ET project (not too demanding above a few Hz)
Passive isolation compliant above about 3-4 HzDesign Study necessary if lower frequency will be investigated
Actuation Noise is the major concern
Conclusions