Status report of the gravitational wave detector AURIGA J.P. Zendri * - - PowerPoint PPT Presentation

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status report of the gravitational wave detector auriga
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Status report of the gravitational wave detector AURIGA J.P. Zendri * - - PowerPoint PPT Presentation

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Status report of the gravitational wave detector AURIGA J.P. Zendri * For the Auriga Collaboration I.N.F.N. Padova Section, Via Marzolo 8, 35010 Padova, Italy, Zendri@lnl.infn.it Next Auriga run 1. More sensitive readout 2. New cryogenic

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Status report of the gravitational wave detector AURIGA

J.P. Zendri* For the Auriga Collaboration

I.N.F.N. Padova Section, Via Marzolo 8, 35010 Padova, Italy, Zendri@lnl.infn.it

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Next Auriga run

1. More sensitive readout 2. New cryogenic suspensions 3. Simplified cryogenics 4. New DAQ system and data analysis

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

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SLIDE 3

1.The new readout

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

Scheme

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SLIDE 4
  • 1. The new readout

Transducer Test Facility

  • Cryogenic suspensions 180 db @ 1KHz
  • Dilution refrigerator
  • Fast thermal cycle (few days)

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

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SLIDE 5

1.The new readout:results

Separated modes: Transducer thermal noise

T=4.6±0.4 K Measures at 4.2 K

6 6

938.18 1.1 10 3.8 1168.6 0.4 10

mec mec Tr el el

Hz Q m Kg Hz Q ν ν = = × = = = ×

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

( )

el mec

ν ν ≠

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SLIDE 6

1.The new readout

Separated modes: amplifier W.B. noise and LC thermal noise

1.5 2.0 2.5 3.0 3.5 4.0 4.5 0.6 0.8 1.0 1.2 1.4 1.6

White Band Noise

Msq

2SII [(µφ0) 2)/Hz])

Termodynamic Temperature [K]

1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5

Back-Action plus Thermal noise (el. Mode) Mode Temperature [K] Thermodinamic Temperature [K]

Measured Energy Sensitivity a 20 E t 1.5 K = ( ) / 350

el

K µ ω ∆ h

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

( )

el mec

ν ν ≠

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1.The new readout

Tuned modes: noise measurements

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

(measured) Fitting function: PSD (measured)

1 e ( ) Z ω   ℜ    

B

1 T 4.2 0. 2 k e ( ) 2 Z T K ω   ℜ  = ±   

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SLIDE 8

2.The new cryogenic suspensions

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

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2.The new cryogenic suspensions

Mode Number FEM predict [Hz] FEM accur acy [%] Meas ured [Hz] FEM pred. brass [Hz] FEM accura cy [%] Measur ed [Hz] 1 74.8 4.3 69.4 38.4 4.5 38.8 2 74.9 4.9 69.4 38.6 5.2 40.0 3 149.4 4.0 140.0 74.6 4.1 74.2 4 168.3 1.9 160.6 86.1 2.7 82.5 5. 185.7 3.2 190.0 86.5 1.8 86.9 6. 186.0 3.2 190.1 86.6 3.2 87.7 7. 1796.0 2.1 1820. 1852.0 2.5 1815.0

Mode 1-2 Mode 3 Mode 4 Mode 5-6 Mode 7

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

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  • 2. The new cryogenic suspension

Last suspension stage

Bar Suspension Tube (CuAl)

Old Set-up New configuration

  • Geometric attenuation gain 10 db
  • First violin 1300 Hz
  • First longitudinal 200 Hz

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

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SLIDE 11
  • 2. The new cryogenic suspension

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

Transducer Electronics wiring support LHe4 vessel Al2081 holder Main Attenuator Compression Spring Thermal Shield

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  • 2. The new cryogenic suspensions

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

Present Status

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  • 3. The new cryogenics

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

Cryostat 100 K 20 K IVC Liquid helium Dewar: 100 liters

A new 100 liters LHe4 dewar is installed For the next Auriga run the detector temperature will be 1.5 K

  • Stable cryogenic temperature
  • Time to solve 1K-pot problem

In the next run this dewar will hold the cold part of the dilution refrigerator

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SLIDE 14
  • 4. New DAQ & data analysis

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

DAQ ( CHEP03 at www-conf.slac.standford.edu)

  • Same Front-end
  • Linux, C++
  • Frame format

Data analysis

  • Optimized for the incremented bandwidth
  • Frame format
  • Burst
  • More general templates (less then few seconds)
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SLIDE 15

Predicted noise curve for the next AURIGA run

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

For impulsive signal:

23 1 min

H ( ) 6 10 1500 Hz ω ε

− −

= × = h For a ms pulse:

19 min

1.2 10 h

−

= ×

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SLIDE 16

Near future improvements

Auriga Ultracryogenic

Preliminary results

  • At 0.2 K the SQUID

noise is 35 ħ (P.Falferi this conf.) Still Open Questions:

  • Is the LC resonator

thermal at 0.1 K?

  • Are we able to reduce

the disturbances of the 1K pot vibrations?

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri

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SLIDE 17

Conclusions

  • 1. The resonant detector of gravitational wave

AURIGA is about to start its second run

  • 2. Compared to the previous run the sensitivity and

the bandwidth should be increased of at least one

  • rder of magnitude
  • 3. The up-graded detector has been designed to

maximize the observation duty cycle and to reduce as much as possible the non gaussian noise which strongly affected the G.W. detectors sensitivity

XXXVIIIth Rencontre de Moriond, 2003, J.-P.Zendri