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R&D activities in Florence Geppo Cagnoli INFN and U. of Glasgow WG2 & WG3 Meeting – 27th Apr. 2006 - Firenze Firenze/Urbino group • 6 Staff members working on STREGA: • • • • • Flavio Vetrano Filippo Martelli Giovanni Losurdo Francesco Piergiovanni Geppo Cagnoli Francesco Marin • Supporting staff members: – Andrea Vicere’ – Gianluca Guidi • 2 Post docs: Enrico Campagna Francesco Marino • 2 PhD Students: Matteo Lorenzini Elisabetta Cesarini 27th April 2006 WG2/3 Meeting - GWA - Firenze 2 of 19 Firenze and Urbino 27th April 2006 WG2/3 Meeting - GWA - Firenze 3 of 19 Activities 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 4 of 19 Silicon fibres measurements setup Fibre is clamped with 2 Al blocks Vacuum chamber P = 10-5/10-6 mbar X-Y shadow sensor Fibre profile measurements setup 27th April 2006 Finite element analysis WG2/3 Meeting - GWA - Firenze photodiodes exciter 5 of 19 Achievements • Profiling and modelling 27th April 2006 WG2/3 Meeting - GWA - Firenze 6 of 19 Achievements cont. • Measurements L=111.5 mm average diameter 242 mm L=308 mm fp 1 p 2.16 average diameter 574 mm k (1 c) cV d 2 L [mm] Y [GPa] a [1/K] k [W/(mK)] c 111.5±0.5 308.0±0.5 150±11 174±12 (2.54±0.13) (2.56±0.11) 146±13 138±11 0.018±0.002 - 27th April 2006 WG2/3 Meeting - GWA - Firenze 7 of 19 Open points • Excess losses with 1.5mm diameter fibre loss angle 1.2E-04 9.19e-4 48kg round 1.0E-04 55kg flat 8.0E-05 New clamp hand tightened Slotted clamp 100 kg Slotted clamp - broken fibre 6.0E-05 Short head - hand tightened 4.0E-05 2.0E-05 thermoelastic 0.0E+00 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Frequency [Hz] 27th April 2006 WG2/3 Meeting - GWA - Firenze 8 of 19 Open points cont. • Like in Glasgow we used a piezo for sensing and for exciting the structure 1.E-02 Without mass With 600 g mass Amplitude [V] 1.E-03 Fibre 1.E-04 1.E-05 Structure 1.E-06 0 500 1000 1500 2000 2500 3000 Frequency [Hz] 27th April 2006 WG2/3 Meeting - GWA - Firenze 9 of 19 Open points cont. • Excess losses are higher for the “orthogonal” than for “parallel” modes (!!) 1.E-01 orthogonal 1 Amplitude [V] 1.E-02 2 3 parallel 1.E-03 4 5 6 7 1.E-04 1.E-05 10 100 1000 10000 Frequency [Hz] Force and torque on the clamp (G.Cagnoli, F. Martelli, F. Piergiovanni) 2 2 2 d L F 3.2 103 1 mm 20 cm d L M 5.8 10 1 mm 20 cm 4 27th April 2006 WG2/3 Meeting - GWA - Firenze E T ai N 11 1.7 10 Pa 106 J 11 1 2 E T Nm 11 1.7 10 Pa 106 J 10 of 19 Cryogenic facility Study of the properties of materials suitable for 3rd generation interferometric GW detectors To be performed inside the JRA3-STREGA collaboration Measurements concern Thermal conductivity Crystalline Silicon Samples Thermal expansion coefficient Q measurements (possible, but our set up is not optimized for this) 27th April 2006 WG2/3 Meeting - GWA - Firenze 11 of 19 The cryostat A.S. Scientific cryostat Experimental volume: about 14 dm3 Vacuum chamber Outer tank Liquid N2 Inner tank Liquid He Outer cold shield Inner cold shield 30 cm Optical windows 27th April 2006 Experimental chamber WG2/3 Meeting - GWA - Firenze Optical windows 12 of 19 Thermal conductivity measurement INSULATOR BOX HEATER CLAMP THERMOMETERS SAMPLE SAMPLE HEATER COPPER BOX ΔT P= ΔT = 1 K Rt L k= Rt St 27th April 2006 WG2/3 Meeting - GWA - Firenze 13 of 19 Measurement of the power loss • We are measuring the heat lost by wire conduction and radiation 1mW of heating power INSULATOR BOX HEATER CLAMP THERMOMETERS SAMPLE SAMPLE HEATER COPPER BOX At room temperature we have measured: Heat Capacity of the sample 4.2 J/K Heat Conductivity 3.7 mW/K 27th April 2006 WG2/3 Meeting - GWA - Firenze 14 of 19 Thermal expansion measurement facility 27th April 2006 WG2/3 Meeting - GWA - Firenze 15 of 19 Measuring cavity Very soft elastic blades Sample Laser Mobile clamp Mirrors 27th April 2006 WG2/3 Meeting - GWA - Firenze Fixed clamp 16 of 19 The reference cavity Vacuum chamber hosting reference cavity Heating wires for RC temperature control Elastic Cu/Be blades Mirror Reference material: zerodur Piezo actuator Result of the temperature stabilization (Matteo Lorenzini) 27th April 2006 WG2/3 Meeting - GWA - Firenze 1K 1h 17 of 19 Photothermal effect facility Small spot size results C1 QW PD1 Frequency servo loop Oscilloscope + PC PBS AOM Cavity servo loop 13.3 MHz C2 PD2 Laser O.I. PD4 EOM2 EOM1 BS PBS QW PD3 Low frequency: size effect High frequency: coating effect 27th April 2006 WG2/3 Meeting - GWA - Firenze 18 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 27th April 2006 WG2/3 Meeting - GWA - Firenze 19 of 19