1. 1 Investigation on annealing effect in a Suprasil sample and loss measurements in silicon samples 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Elisabetta Cesarini Elisabetta Cesarini a,b), Gianpietro Cagnoli a,c), Enrico Campagna a,d), Matteo Lorenzini a,b), Giovanni Losurdo a), Filippo Martelli a,d), Francesco Piergiovanni a,d), Flavio Vetrano a,d) a)INFN Sez. Firenze b)Università di Firenze (Dip. Astronomia e Scienza dello Spazio) c)University of Glasgow d)Università di Urbino

2. 2 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Summary Now: We are measuring the loss angle of different interesting materials: Herasil Suprasil (annealed sample, that we are investigating with surface analysis) Silicon (we are trying to calculate the thermoelastic contribution to fit our measurements) Now: We are measuring the loss angle of different interesting materials: Herasil Suprasil (annealed sample, that we are investigating with surface analysis) Silicon (we are trying to calculate the thermoelastic contribution to fit our measurements) Last ILIAS-GW meeting 26-27 October 2006 we presented: Q measurement facility Innovative nodal suspension, designed and realized (GeNS) Last ILIAS-GW meeting 26-27 October 2006 we presented: Q measurement facility Innovative nodal suspension, designed and realized (GeNS)

3. 3 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Dissipation measurements on Suprasil samples 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 SAMPLE: Suprasil 311 disk 75x3 mm Sapphire sphere D= 4.75 mm SAMPLE: Suprasil 311 disk 75x3 mm Sapphire sphere D= 4.75 mm 3469 Hz 1° Butterfly mode 3469 Hz 1° Butterfly mode Contact surface (radius 20 m) 7890 Hz 2° Butterfly mode 7890 Hz 2° Butterfly mode Q does not depend on suspension centering, in a single suspension, in the region between -30μm e +30μm with a contact surface of ~20 μm

4. 4 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Dissipation measurements on Suprasil samples First measurement: Q(3469Hz)=2.7·10 6 Measurement after the annealing: Q(3469Hz)=2·10 7 Anneal in air (suggested by S.Penn) : -Raise the oven temperature to the annealing point (1120°C for Suprasil) - Cool down to the strain temperature (1025°C for Suprasil) with a rate of about 10 degrees per hour -Turn off the oven and wait for cool down in 24 hours Anneal in air (suggested by S.Penn) : -Raise the oven temperature to the annealing point (1120°C for Suprasil) - Cool down to the strain temperature (1025°C for Suprasil) with a rate of about 10 degrees per hour -Turn off the oven and wait for cool down in 24 hours V/S = 1.3875 μm φ Penn = 2 · 10 -8 Q Penn = 50 millions Q exp = 20 millions V/S = 1.3875 μm φ Penn = 2 · 10 -8 Q Penn = 50 millions Q exp = 20 millions Taken from Mechanical Loss in Fused Silica Steve Penn Hobart and William Smith Colleges LSC Meeting, March 2006 LIGO DCC LIGO-G0601 40-00-Z Taken from Mechanical Loss in Fused Silica Steve Penn Hobart and William Smith Colleges LSC Meeting, March 2006 LIGO DCC LIGO-G0601 40-00-Z FI samples Similar samples it is smaller by a factor two!!

5. 5 Binding Energy (eV) counts/s 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Annealing study Is the Q value increasing due to an internal or a surface effect? Is the Q value increasing due to an internal or a surface effect? Surface Analysis In collaboration with: INFN sezione Genova and Università di Genova Surface Analysis In collaboration with: INFN sezione Genova and Università di Genova Ellipsometry and XPS … still under investigation …

6. 6 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Dissipation measurements on silicon samples Samples: 75x1 mm 75x3 mm sapphire sphere (d=4.76 mm) 75x10 mm sapphire sphere (d=15-20 mm) Samples: 75x1 mm 75x3 mm sapphire sphere (d=4.76 mm) 75x10 mm sapphire sphere (d=15-20 mm) RESULT SUMMARY Bad reproducibility of measurements in different suspensions Bad reproducibility of measurements in different suspensions CLEANING PROCEDURE We have to work in a clean room!!! CLEANING PROCEDURE We have to work in a clean room!!!

7. 7 Taking into account only the maximum values … 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Dissipation measurements on silicon samples WHAT IS HAPPENING?

8. 8 ADIABATIC APPROXIMATION: The T is not influenced by heat fluxes ADIABATIC APPROXIMATION: The T is not influenced by heat fluxes 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Thermoelastic contribution calculation Thermoelastic contribution for a disk of finite dimensions Previous calculations : - F. Bondu, P. Hello, J.Y. Vinet, Phys. Lett A 246 (1998) 227 -Y.T. Liu and K.S. Thorne, Phys. Rev. D 62 (2000) 122002 - V. B. Braginsky, M.L. Gorodetski, S.P. Vyatchanin, Phys Lett. A 264 (1999) 1 Previous calculations : - F. Bondu, P. Hello, J.Y. Vinet, Phys. Lett A 246 (1998) 227 -Y.T. Liu and K.S. Thorne, Phys. Rev. D 62 (2000) 122002 - V. B. Braginsky, M.L. Gorodetski, S.P. Vyatchanin, Phys Lett. A 264 (1999) 1 What is our idea? How to solve the problem of the sources in a non-adiabatic condition for a cristalline material? How to solve the problem of the sources in a non-adiabatic condition for a cristalline material? We want to calculate exactly the thermoelastic contribution without any approximation We want to calculate exactly the thermoelastic contribution without any approximation We want to simulate the vibrations ANSYS of the disk with ANSYS, then take the time derivative of the deformations and put them in the diffusion heat equation. We want to simulate the vibrations ANSYS of the disk with ANSYS, then take the time derivative of the deformations and put them in the diffusion heat equation. … work in progress …

9. 9 4° ILIAS-GWA Annual Meeting - Tubingen (D), October 8-9, 2007 Next work… 1.New surface analysis after the annealing, trying to understand if the produced effect is internal or superficial. 2.Calculation of the thermoelastic contribution in silicon disks, without any approximation. 3.New loss measurements of the silicon samples with different thickness (in collaboration with Jena University). 4.Measurements of mechanical properties of coated samples suitably altered or damaged. 1.New surface analysis after the annealing, trying to understand if the produced effect is internal or superficial. 2.Calculation of the thermoelastic contribution in silicon disks, without any approximation. 3.New loss measurements of the silicon samples with different thickness (in collaboration with Jena University). 4.Measurements of mechanical properties of coated samples suitably altered or damaged.

10. 10 Thanks for your attention