R&D activities in Florence Geppo Cagnoli INFN and U. of Glasgow WG2 & WG3 Meeting – 27 th Apr Firenze

27th April 2006WG2/3 Meeting - GWA - Firenze2 of 19 Firenze/Urbino group 6 Staff members working on STREGA: Flavio VetranoFrancesco Marin Filippo Martelli Giovanni Losurdo Francesco Piergiovanni Geppo Cagnoli Supporting staff members: –Andrea Vicere’ –Gianluca Guidi 2 Post docs: Enrico CampagnaFrancesco Marino 2 PhD Students: Matteo Lorenzini Elisabetta Cesarini

27th April 2006WG2/3 Meeting - GWA - Firenze3 of 19 Firenze and Urbino

27th April 2006WG2/3 Meeting - GWA - Firenze4 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 2006WG2/3 Meeting - GWA - Firenze5 of 19 Silicon fibres measurements setup Vacuum chamber P = /10 -6 mbar Fibre is clamped with 2 Al blocks Fibre profile measurements setup Finite element analysis X-Y shadow sensor exciter photodiodes

27th April 2006WG2/3 Meeting - GWA - Firenze6 of 19 Achievements Profiling and modelling

27th April 2006WG2/3 Meeting - GWA - Firenze7 of 19 Achievements cont. Measurements L=111.5 mm average diameter 242 m L [mm]Y [GPa]  [1/K]  [W/(mK)] c 111.5±0.5150±11 (2.54±0.13)146± ± ±0.5174±12 (2.56±0.11)138±11- L=308 mm average diameter 574 m

27th April 2006WG2/3 Meeting - GWA - Firenze8 of 19 Open points Excess losses with 1.5mm diameter fibre thermoelastic

27th April 2006WG2/3 Meeting - GWA - Firenze9 of 19 Open points cont. Like in Glasgow we used a piezo for sensing and for exciting the structure Fibre Structure

27th April 2006WG2/3 Meeting - GWA - Firenze10 of 19 Open points cont. Excess losses are higher for the “orthogonal” than for “parallel” modes (!!) orthogonal parallel Force and torque on the clamp (G.Cagnoli, F. Martelli, F. Piergiovanni)

27th April 2006WG2/3 Meeting - GWA - Firenze11 of 19 Cryogenic facility Study of the properties of materials suitable for 3 rd 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 expansion coefficient

27th April 2006WG2/3 Meeting - GWA - Firenze12 of 19 The cryostat 30 cm A.S. Scientific cryostat Experimental volume: about 14 dm 3 Inner cold shield Outer cold shield Optical windows Inner tank Liquid He Outer tank Liquid N 2 Vacuum chamber Experimental chamber

27th April 2006WG2/3 Meeting - GWA - Firenze13 of 19 Thermal conductivity measurement INSULATOR BOX HEATER COPPER BOX CLAMP SAMPLE THERMOMETERS SAMPLE HEATER

27th April 2006WG2/3 Meeting - GWA - Firenze14 of 19 Measurement of the power loss We are measuring the heat lost by wire conduction and radiation INSULATOR BOX HEATER COPPER BOX CLAMP SAMPLE THERMOMETERS SAMPLE HEATER 1mW of heating power At room temperature we have measured: Heat Capacity of the sample 4.2 J/K Heat Conductivity 3.7 mW/K

27th April 2006WG2/3 Meeting - GWA - Firenze15 of 19 Thermal expansion measurement facility

27th April 2006WG2/3 Meeting - GWA - Firenze16 of 19 Measuring cavity Sample Mirrors Fixed clamp Mobile clamp Laser Very soft elastic blades

27th April 2006WG2/3 Meeting - GWA - Firenze17 of 19 The reference cavity Vacuum chamber hosting reference cavity Heating wires for RC temperature control Mirror Reference material: zerodur Piezo actuator Elastic Cu/Be blades 1 h 1 K Result of the temperature stabilization (Matteo Lorenzini)

27th April 2006WG2/3 Meeting - GWA - Firenze18 of 19 Photothermal effect facility Small spot size results Low frequency: size effect High frequency: coating effect

27th April 2006WG2/3 Meeting - GWA - Firenze19 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