ilias gw meeting mallorca - october 23-24, 2005luca taffarello status of the commissioning of the...
TRANSCRIPT
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Status of the commissioning of the AURIGA detector
Luca Taffarello
(INFN Sezione di Padova)
on behalf of AURIGA Collaboration
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Summary of the talk: New detector set-up First Results, calibration and thermal behaviour Investigation of the un-modelled noise peaks
• Up-conversion of low frequency vibrations
Solution of the problem• New mechanical isolation at low frequency
Result achieved: very stable and gaussian behaviour• Duty Cycle 98 % (from 19th May 2005)
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
new mechanical suspensions: attenuation > 360 dB at 1 kHz FEM modelled
new capacitive transducer: two-modes (1 mechanical+1 electrical) optimized mass
new amplifier: double stage SQUID 200 energy resolution
new data analysis: C++ object oriented code frame data format
Expected target AURIGA II run with 1999-2003 upgrades
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
II RUN @ T = 4.5K = data = simulation
Best initial result of II run
Noise hunting in cryogenic operation
•Spurious peaks in the sensitive band•High false alarm rate
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Non Stationary Performances
F5
F5
F5
F5
F1
F1
F1
F1
It is possible to classify spurious peaks in correlated “Families” (F1..F5..)in time families appear and dissapear
Tim
e (5
hou
rs)
Sensitive frequency band
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Measurement of the real part of the impedence seen by the SQUID
No evidence of discharge
HV E bias=7.5 MV/m
‚ ƒ =865.68 Hz
‚ =914.14 Hz
ƒ =955.63 Hz
Calibration: The dissipations of the 3 sensitives modes
Q in operation ~ 400-1000cold-damping
QLV=1.15 106
QHV=1.15 106
QLV=5 106
QHV=0.74 106
QLV=0.45 106
QHV=0.75 106
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Calibration: the mechanical transfer function of the antenna
VERY IMPORTANT not evident excitation with mechanical and-or electromagnetic actuators
A
B
C
A
mechanical modes in the transducer charge line
B
Electromechanical modes
C
Mechanical modes of the charge plates
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
894 Hz Spurious peak in the sensitive band
SQUID output18-22 Hz
Seismometer 8-22 Hz
Accelerometer Inside vacuum chamber8-22 Hz
4 days friday-monday
Low Frequency Motions are Up-Converted!
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Evidence of the connection between the external (seismic) activity
and the spurious peaks excitation in the sensitive band
1
DAY
OUTPUT ofSEISMOMETERon top of the cryostat0-22 Hz
sensitive bandwidth
to determine a correlation between the external disturbances and the response in the sensitive bandwidth
Evidence for nolinear behaviour
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Run 590 (Time-Frequency) from Sat 11h-13/11/04 to Mon 12h-15/11/04
Clean Raw Data
Noisy Raw Data
Sat
Sun
Mon
Only during the Sunday nigth it is possible to get clean spectraThe duty cycle “gaussian and stationary” very poor 20 %, evidence of effects of Human Activity
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Low frequency mechanical excitation and response in the detector bandwidth
2 example also without electrical field
Shaking frequency 18.62 HzEffect: all the multiple
Shaking frequency 16.57 HzEffect: some cluster with more peaks equidistant 16.57/3 Hz
Not possible to reach shaking frequencybelow 10 Hz the seismic noise is too power
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Strategy: new mechanical isolation at low frequency
Step 1: Dissipation stacks material: Polyurethane (Sylodamp by Angst
Pfister),high dissipation Q=2roll-off frequency 8-10 Hz
Step 2: Active-air mounts (Vibraplane by Kinetic Systems)
internal damping Q=2 lower natural frequencies 1-2 Hz,automatic leveling/height control
Hardware up-grades integrated during cryogenic operations
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Position control feed-backlift used with the liquid heliuminside the dewars
STEP 1: rubber stacks between floor and cryostat supports2 Dec. 2004
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
800 850 900 950 10001x10-22
1x10-21
1x10-20
1x10-19
AURIGA T=4.5K
Sh
h
0.5 [
Hz-1
/2]
Frequency [Hz]
- noise prediction- mechanical thermal - LC thermal- SQUID back action - SQUID additive
First breakthrough: achieved design sensitivity (Dec 2004)
60% DUTY CYCLE !!!
Go ahead !!
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
F5 Veto 236.95+/- 0.2 Hz F5 893.63 Hz
F5 Veto
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
F5Threshold
veto
F5Noise Amplitude @ 236.95+/- 0.2 Hz
F5Veto
ampl
itude
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
AURIGA Events [no vetoes]
SN
R
Italian Holiday
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
AURIGA Events AFTER vetoes
SN
R
Is possible to apply the epoch vetoes and the result is a duty cycle 60 %
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
SNR Distribution AFTER vetoes (Simulation=Red)
SNR
3 eventswith SNR >10during9 days
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Second Step: seismic isolation up-gradeexternal suspensions low frequency with vibrational damping
Air springs: effective above 1-2 Hz
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Metal-arc welding on cryostat while keeping liquid helium in
“wings” to support Auriga above the center of mass of the cryostat
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Step 2: integration of low frequency suspensions (May 19th)
Final configuration Ferroconcrete Pillar
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
“Before the up-grade”
“After the up-grade”
Last breakthrough:
achieved 98% Duty Cycle (May 2005)
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
On line effect (May 19th)
suspension activation
1 hour
Sensitive frequency band
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Low frequency motion comparison
0 20 40 60 80 1001E-14
1E-13
1E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6Bar endface displacement
24/05/05 air suspensions on 17/05/05 air suspensions off
S xx
1/2
m/H
z1/2
Frequency [Hz]
ILIAS GW Meeting Mallorca - October 23-24, 2005 Luca Taffarello
Absolute amplitude 5.7 10-22 / Hz
Current AURIGA Burst Search• Thermal at 4.5 K • 13.6 days,• Epoch vetoes not needed apart from cryogenic maintenance• Duty time 98%• Very stationary• Gaussian noise• Outliers 9 events/day with SNR > 6• Event rate 3700 /day with SNR > 4