the status report of the auriga detector
DESCRIPTION
The status report of the AURIGA detector. Luca Taffarello (INFN Sezione di Padova ). Special tanks to L. Conti and G. Vedovato. Summary of the talk:. New detector set-up First Results, calibration and thermal behaviour BUT evidence of noise peaks - PowerPoint PPT PresentationTRANSCRIPT
WP1 Teleconference June 14 2005 Luca Taffarello
The status report of the AURIGA detector
Luca Taffarello
(INFN Sezione di Padova )
Special tanks to L. Conti and G. Vedovato
WP1 Teleconference June 14 2005 Luca Taffarello
Summary of the talk: New detector set-up First Results, calibration and thermal behaviour BUT
evidence of noise peaks External excitation to identify the input ports to avoid
the noise (mechanical excitation @ low frequencies) Strategy to overcome the disturbances
Definition of epoch vetoes in A.D. througt thresold identification New dampers and pneumatic isolation system @ low frequencies
Result achieve1. Good data in nigth and week end (2° Dec 2004-18° May
2005)2. Very stable and gaussian behaviour (from 19 May 2005)
WP1 Teleconference June 14 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
WP1 Teleconference June 14 2005 Luca Taffarello
Evidence of spurious peaks in the bandwidth
Setting @ T = 4.5K = experimental. data = simulation
immediatly is started a diagnostic phase to addressthe spurious features in the noise spectra
Best quiet period December 2003
WP1 Teleconference June 14 2005 Luca Taffarello
The thermal behaviour of the modes is estimates by the measurement of the real part of the input impedence to the SQUID a 4.5 K
Not evident lost of charge
T= 4.5 KE bias=7.5 MV/m
‚ ƒ 61.15 10scaricoQ =865.68 Hz
61.15 10caricoQ
‚ =914.14 Hz65 10scaricoQ
60.74 10caricoQ ƒ =955.63 Hz
60.75 10caricoQ
60.45 10scaricoQ
1000 400cold dampedQ
This is thermal
First step: Calibration of the 3 sensitives modes
WP1 Teleconference June 14 2005 Luca Taffarello
2 Step: THE MECHANICAL TRANSFER FUNCTION
VERY IMPORTANT not evident excitation with mechanical and-or electromagnetic actuators
‚
ƒ
mechanical mode near the switch
Electrome-chanical modes
Mechanical modes of the charge plates
WP1 Teleconference June 14 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
Complete control of the internal sources of noise(Note: one-sided spectra !)
December 2004after the firstup-grading detector up therubber
WP1 Teleconference June 14 2005 Luca Taffarello
Strategy to cope the spurious peaks Identification of noise sources: noise hunting Definition of the possible hardware solutions: 2 steps
1. Rubber dissipation layer below the cryostat(roll-off frequency 8-10 Hz Q=2)
2. Active-air mount (Vibraplane KS) automatic leveling/heigth control low vertical natural frequency and orizontal isolation 1-
2 Hz internal damping Q=2 and broad load range)
Very important parameter the Q factor to avoid other nolinear-coupling where the seismic power is higher and the movement of the cryostat can generate dangerous mechanical stress in the detector
Decision to maintain on air the detector because from the analysis data is possible to understand more what is wrong and to control directly the efficiency of the new set-up
Definition of epoch vetoes to obtain time period of data workable
WP1 Teleconference June 14 2005 Luca Taffarello
Noise hunting: 3 step analysis
1. Definition of peaks or band noise sources2. Identification of noise sensitive peaks out
bandwidth3. Application of epoch vetoes based by
crossing thresholds previous defined applied to this out bandwidth peaks
WP1 Teleconference June 14 2005 Luca Taffarello
Analysis of auxiliary channelsSpurious peak in bandwidth894 Hz
SQUID output18-22 Hz
Sismometer 8-22 Hz
Acc. Inside vacuum chamber8-22 Hz
4daysfriday-monday
WP1 Teleconference June 14 2005 Luca Taffarello
Evidence of connection between external (seismic) activities and bandwidth
1
DAY
OUTPUT ofSISMOMETERin the cryostat0-22 Hz
sensitive bandwidth
Not Possibleto determine a correlation between the external disturbances and the response in the sensitive bandwidth
Evidence for not-linearity behaviour
WP1 Teleconference June 14 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
WP1 Teleconference June 14 2005 Luca Taffarello
Sunday - Clean Spectrum
950 Hz
900 Hz
Sp
Sp
Sp
Sp S
p
Sp= spurious One year of data between dec. 03 to dec 04
WP1 Teleconference June 14 2005 Luca Taffarello
Clean/Noisy Spectrum
“Normal” Noisy spectrum
WP1 Teleconference June 14 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 is possible see the better spectraduty cycle Gaussian and stationary very poor 20 %, evidence of Monday morning effect, Human Activities?
WP1 Teleconference June 14 2005 Luca Taffarello
Run 590 (Time-Frequency)5 hours
F5
F5
F5
F5
F1
F1
F1
F1
It is possible to define some group of spurious peaks correlatedF means Family, during the history different family appear and dissapear
WP1 Teleconference June 14 2005 Luca Taffarello
Run 608 - Vetoes
F5 Veto (120 s)236.95 +/- 0.2
Hz
Wide Band Veto
Wide BandSpurious
F5
F1 Veto (60 s)241.25 +/- 0.5
HzF7 Veto (60 s)1133.2 +/- 2 Hz
F1
F7
More clean data, long period good in the nigths and in week-end
4000 s Time-frequency behaviour during normal day
WP1 Teleconference June 14 2005 Luca Taffarello
F5 Veto 236.95+/- 0.2 Hz F5 893.63 Hz
F5 Veto
WP1 Teleconference June 14 2005 Luca Taffarello
F5Threshold
veto
F5Ada lck psp plugin @ 236.95+/- 0.2 Hz
F5Veto
ampl
itude
WP1 Teleconference June 14 2005 Luca Taffarello
Previous position
Position control feed-backlift used with the liquid heliuminside the dewars
First hardware up-grade: rubber layer of Sylodamp (Angst Pfister)
Starting new run 2 Dec. 2004
WP1 Teleconference June 14 2005 Luca Taffarello
AURIGA Events [no vetoes]
SN
R
Italian Holiday
WP1 Teleconference June 14 2005 Luca Taffarello
AURIGA Events [with vetoes]
SN
R
Is possible to apply the epoch vetoes and the result is a duty cycle 60 %
WP1 Teleconference June 14 2005 Luca Taffarello
AURIGA Events [with vetoes & prob>0.00001]
SN
R
a test of consistency about the shape of the burst
WP1 Teleconference June 14 2005 Luca Taffarello
AURIGA Events [with vetoes & prob>0.00001]
Am
plitu
de
Good stability of the detector in absolute amplitude
WP1 Teleconference June 14 2005 Luca Taffarello
SNR Distribution (with vetoes) (Simulation/Red)
SNR
3 eventswith SNR >10during9 days
WP1 Teleconference June 14 2005 Luca Taffarello
Last hardware up-grade:external suspensions low frequency and with vibrational damping
Air springs: effective above1-2 Hz
WP1 Teleconference June 14 2005 Luca Taffarello
Metal-arc welding with liquid helium inside the dewarswithout bias in the trasducer
A kind of “wings” to support Auriga above the center of mass of the cryostat
WP1 Teleconference June 14 2005 Luca Taffarello
Low frequency suspensions installed (May 19th)
Final configuration Ferroconcrete Pillar
WP1 Teleconference June 14 2005 Luca Taffarello
Low frequency suspensions installed (May 19th)
suspension activation
WP1 Teleconference June 14 2005 Luca Taffarello
Before the up-grade
AFTER! Also during the day
WP1 Teleconference June 14 2005 Luca Taffarello
Low frequency suspensions installed (May 19th)before after
Not so evident and dramatic the isolation effect, but impressive the effect in the data!
in the best case 1 order of magnitude in amplitude
WP1 Teleconference June 14 2005 Luca Taffarello
Perfect Gaussian and stationarybehaviour, duty cycle > 98%