1. JRA3 STREGA - Introduction Geppo Cagnoli IGR – University of Glasgow ILIAS-GW Meeting, Orsay, 5 th -6 th Nov 2004

2. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20042 10 0 10 9 10 6 [Hz]10 3 Bars and Spheres RF Cavities Interferometers Overview on GW detection The expected strain of space is 10 -22 Hz -1/2 or lower

3. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20043 Ultimate limits on GW detection All the detectors are mainly limited by thermal noise that causes fluctuations on position and shape of the test masses  Interferometers: thermal noise in mirrors and in suspension fibres  Bars/Spheres: thermal noise in the resonant elements  RF cavities: thermal noise in the cavity walls and in the e.m. field

4. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20044 STREGA Mission Lower thermal noise 10 times with respect to the second generation detectors

5. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20045 IFOS TH.NS BAND Detectors Generations 1 101001k10k Frequency [Hz] 10 -22 10 -23 10 -24 10 -25 10 -19 10 -20 10 -21 h [ Hz –1/2 ] GEO600 LIGO VIRGO AURIGA NAUTILUS 1 ST GENERATION FOR IFOS STEEL SUSPENSIONS (APART GEO600) ROOM TEMPERATURE FOR RESONATORS ALUMINIUM CYLINDERS 100mK < T < 4K LIGO SCIENTIFIC RUN 3 POSSIBLE DETECTION OF NS/NS MERGING WITHIN THE LOCAL GROUP DISTANCE < 1.8 MPc 1 ST GENERATION SHOULD REACH THE VIRGO CLUSTER AT 17MPc

6. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20046 Detectors Generations 1 101001k10k Frequency [Hz] 10 -22 10 -23 10 -24 10 -25 10 -19 10 -20 10 -21 h [ Hz –1/2 ] GEO600 LIGO VIRGO AURIGA NAUTILUS 1 ST GENERATION FOR IFOS STEEL SUSPENSIONS (APART GEO600) ROOM TEMPERATURE FOR RESONATORS ALUMINIUM CYLINDERS 100mK < T < 4K 2 ND GENERATION FOR IFOS SILICA SUSPENSIONS HIGHER LASER POWER ROOM TEMPERATURE FOR RESONATORS CuAl SPHERES T < 100mK BETTER READOUT RF CAVITIES 1 ST DETECTORS AD. LIGO AD. VIRGO MiniGRAIL PACO

7. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20047 Detectors Generations 1 101001k10k Frequency [Hz] 10 -22 10 -23 10 -24 10 -25 10 -19 10 -20 10 -21 h [ Hz –1/2 ] GEO600 LIGO VIRGO AURIGA NAUTILUS 1 ST GENERATION FOR IFOS STEEL SUSPENSIONS (APART GEO600) ROOM TEMPERATURE FOR RESONATORS ALUMINIUM CYLINDERS 100mK < T < 4K 2 ND GENERATION FOR IFOS SILICA SUSPENSIONS HIGHER LASER POWER ROOM TEMPERATURE FOR RESONATORS CuAl SPHERES T < 100mK BETTER READOUT RF CAVITIES 1 ST DETECTORS AD. LIGO AD. VIRGO MiniGRAIL PACO EGO DUAL 3 RD GENERATION FOR IFOS SILICON MIRRORS SILICON SUSPENSIONS HIGHER LASER POWER BETTER COATINGS LOW TEMPERATURE FOR RESONATORS CRISTALLINE MATERIALS DOUBLE RESONATORS T < 10mK SQL Z = 1

8. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20048 … coming back on Earth 3 Objectives for STREGA 1 Research on Materials Outcomes - Selection or Development of the most suitable materials for Mirrors, Suspensions and Resonant Masses - Development of low losses Dielectric Coatings - Investigation on Acoustic Emission caused by Cosmic Rays

9. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 20049 … coming back on Earth 3 Objectives for STREGA 2 Research on Cryogenics Outcomes - Development of a cryogenic system for the interferometers with a low mechanical noise - Design of a last stage suspension able to provide 1W of heat flow at ~5K - Development of a low noise ultra cryogenic system (~10mK) for resonant detectors

10. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 200410 … coming back on Earth 3 Objectives for STREGA 3 Research on Thermal Noise Outcomes - Development of facilities for the direct measurement of Thermo-elastic noise - Development of facilities for the direct measurement of Photo-elastic noise - Novel read-out configurations able to reduce the effect of thermal noise on the signal detected with resonant bars

11. ILIAS-GW Meeting, Orsay, 5 th – 6 th Nov 200411 Some Numbers 124 people of 25 different groups (subgroup of the Network) € 1794 per person per year STREGA web page: http://www.ego-gw.it/ILIAS-GW/ STREGA has the largest number of deliverables among the ILIAS activities (15 in the first 18 months) GOOD WORK !!