r&d activities in florence
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R&D activities in Florence
Geppo CagnoliINFN and U. of Glasgow
WG2 & WG3 Meeting – 27th Apr. 2006 - Firenze
27th April 2006 WG2/3 Meeting - GWA - Firenze 2 of 19
Firenze/Urbino group• 6 Staff members working on STREGA:
• Flavio Vetrano Francesco Marin• Filippo Martelli• Giovanni Losurdo• Francesco Piergiovanni• Geppo Cagnoli
• Supporting staff members:– Andrea Vicere’– Gianluca Guidi
• 2 Post docs: Enrico Campagna Francesco Marino
• 2 PhD Students:Matteo LorenziniElisabetta Cesarini
27th April 2006 WG2/3 Meeting - GWA - Firenze 3 of 19
Firenze and Urbino
27th April 2006 WG2/3 Meeting - GWA - Firenze 4 of 19
Activities on thermal noiseActivities on thermal noise• Modelling of thermal noise for Virgo optics and suspensions
(funded by EGO)• Measurements on crystalline silicon fibres (CRYSTAL
collaboration, funded by INFN )• Study of new materials for 3rd generation interferometric
GW detectors (JRA3-STREGA collaboration)
27th April 2006 WG2/3 Meeting - GWA - Firenze 5 of 19
Silicon fibres measurements setup
Vacuum chamberP = 10-5/10-6 mbar
Fibre is clampedwith 2 Al blocks
Fibre profile measurements setup Finite element analysis
X-Y shadow sensor
exciterphotodiodes
27th April 2006 WG2/3 Meeting - GWA - Firenze 6 of 19
Achievements• Profiling and modelling
27th April 2006 WG2/3 Meeting - GWA - Firenze 7 of 19
Achievements cont.• Measurements
L=111.5 mm average diameter 242 m
L [mm] Y [GPa] [1/K] [W/(mK)] c111.5±0.5 150±11 (2.54±0.13) 146±13 0.018±0.002308.0±0.5 174±12 (2.56±0.11) 138±11 -
L=308 mm average diameter 574 m
2
)1(16.21dccf
Vpp
27th April 2006 WG2/3 Meeting - GWA - Firenze 8 of 19
Open points• Excess losses with 1.5mm diameter fibre
0.0E+00
2.0E-05
4.0E-05
6.0E-05
8.0E-05
1.0E-04
1.2E-04
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000Frequency [Hz]
loss
ang
le
48kg round
55kg flat
New clamp handtightenedSlotted clamp 100 kg
Slotted clamp - brokenfibreShort head - handtightened
9.19e-4
thermoelastic
27th April 2006 WG2/3 Meeting - GWA - Firenze 9 of 19
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
0 500 1000 1500 2000 2500 3000Frequency [Hz]
Am
plitu
de
[V]
Without massWith 600 g mass
Open points cont.• Like in Glasgow we used a piezo for sensing
and for exciting the structure
Fibre
Structure
27th April 2006 WG2/3 Meeting - GWA - Firenze 10 of 19
Open points cont.• Excess losses are higher for the “orthogonal”
than for “parallel” modes (!!)
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
10 100 1000 10000
Frequency [Hz]
Am
plitu
de
[V]
12
34 5
6 7
orthogonal
parallel
2 23
11 63.2 10 N1 mm 20 cm 1.7 10 Pa 10 J 11
id L E TF
1224
11 65.8 10 N m1 mm 20 cm 1.7 10 Pa 10 J
d L E TM
Force and torque on the clamp(G.Cagnoli, F. Martelli, F. Piergiovanni)
27th April 2006 WG2/3 Meeting - GWA - Firenze 11 of 19
Cryogenic facilityStudy of the properties of materials suitable for 3rd generation
interferometric GW detectors
Crystalline Silicon Samples
To be performed inside the JRA3-STREGA collaboration
Measurements concern
Q measurements (possible, but our set up is not
optimized for this)
Thermal conductivity
Thermal expansioncoefficient
27th April 2006 WG2/3 Meeting - GWA - Firenze 12 of 19
The cryostat
30 cm
A.S. Scientific cryostatExperimental volume: about 14 dm3
Inner cold shield
Outer cold shield
Optical windows
Optical windows
Inner tank Liquid He
Outer tank Liquid N2
Vacuum chamber
Experimental chamber
27th April 2006 WG2/3 Meeting - GWA - Firenze 13 of 19
Thermal conductivity measurement
INSULATORBOX
HEATER
COPPERBOX
CLAMP
SAMPLE
THERMOMETERS
SAMPLEHEATER
t
ΔTP = R
ΔT = 1 K
t t
L = R S
27th April 2006 WG2/3 Meeting - GWA - Firenze 14 of 19
Measurement of the power loss• We are measuring the heat lost by wire conduction and radiation
INSULATORBOX
HEATER
COPPERBOX
CLAMP
SAMPLE
THERMOMETERS
SAMPLEHEATER
1mW of heating power
At room temperature we have measured:
Heat Capacity of the sample 4.2 J/KHeat Conductivity 3.7 mW/K
27th April 2006 WG2/3 Meeting - GWA - Firenze 15 of 19
Thermal expansion measurement facility
27th April 2006 WG2/3 Meeting - GWA - Firenze 16 of 19
Measuring cavity
Sample
Mirrors Fixed clampMobile clamp
Laser
Very soft elastic blades
27th April 2006 WG2/3 Meeting - GWA - Firenze 17 of 19
The reference cavityVacuum chamber hosting reference cavity
Heating wires for RC temperature control
Mirror Reference material: zerodur
Piezo actuator
Elastic Cu/Be blades
1 h
1 KResult of the temperature stabilization
(Matteo Lorenzini)
27th April 2006 WG2/3 Meeting - GWA - Firenze 18 of 19
Frequencyservo loop
Laser EOM1O.I.BS
PD1 QW
PBS
13.3 MHz
PD2
QWPBS
PD4
Cavity servo loopAOM
EOM2
C1
C2
PD3
Oscilloscope+
PC
Photothermal effect facilitySmall spot size results
Low frequency:size effect
High frequency:coating effect
27th April 2006 WG2/3 Meeting - GWA - Firenze 19 of 19
Conclusion• First measurement of thermal
conductivity expected soon
• The reference cavity for thermal expansion measurements is being assembled
• Photothermal facility is working successfully
• We are looking forward to show you our labs tomorrow afternoon
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