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ET: Einstein Telescope Michele Punturo INFN Perugia On behalf of the ET design study team ILIAS General meeting, Jaca Feb 2008 1 Evolution of the current GW detectors • Current Gravitational Wave interferometric detectors have a well defined evolution line in the next 5-7 years – LIGO just completed its S5 scientific run – Virgo completed in October 07 its first long scientific run in parallel with LIGO • Both the detectors are in upgrade/commissioning mode to implement their 1.5 generation upgrade step (Virgo+, enhanced LIGO) – GEO is covering (“astrowatch” mode) the down time of LIGO and Virgo in collaboration with the resonant bar detectors • … see G.Losurdo Talk ILIAS General meeting, Jaca Feb 2008 2 h (Hz-1/2) 1st generation GW detectors sensitivities -18 10 1st generation detectors Pulsars hmax – 1 yr integration -19 10 -20 LIGO Credit: P.Rapagnani Virgo 10 BH-BH Merger Oscillations @ 100 Mpc GEO -21 10 Core Collapse @ 10 Mpc QNM from BH Collisions, 100 - 10 Msun, 150 Mpc QNM from BH Collisions, 1000 - 100 Msun, z=1 Resonant antennas BH-BH Inspiral, 100 Mpc -22 NS-NS Merger Oscillations @ 100 Mpc 10 BH-BH Inspiral, z = 0.4 NS, e=10-6 , 10 kpc -23 10 NS-NS Inspiral, 300 Mpc -24 10– May 2, 2006 ESO 1 10 ILIAS General meeting, JacaG.Losurdo Feb 2008 – INFN Firenze 100 3 1000 3 Hz 4 10 “1.5 generation” sensitivities Laser amplifier Higher finesse, lower mirror TN ILIAS General meeting, Jaca Feb 2008 4 Advanced detectors • Enhanced detectors are a step toward the realization of the 2nd generation detectors (“advanced”) – Also GEO will participate to the network of enhanced detectors with an upgraded version, “specialized” in the high frequency regime thanks (mainly) to the signal recycling technology • GEO HF – They are based on “small” changes of the current detectors with available technologies that anticipate the next step • Advanced detectors will be online in the >2013 timeslot – They will be based on known technologies currently under preliminary engineering phase • • • • High power laser (~200W) and compliant optics Lower thermal noise mirrors (substrates and coatings) Lower thermal noise suspensions (FS monolithic suspensions) Better seismic isolation – Active filtering in LIGO – Focused improvements of the Virgo Super-Attenuator • Signal recycling ILIAS General meeting, Jaca Feb 2008 5 Credit: Detection progresses Richard Powell, Beverly Berger. From LIGO presentation G050121 NS-NS (1.4MS): 13 15/50 120/170 Mpc 10 -18 h(f) [1/sqrt(Hz)] st 10 -19 10 -20 10 -21 10 -22 10 -23 10 -24 1 generation: Virgo LIGO 1.5 generation: Virgo+ eLIGO nd 2 generation advVirgo advLIGO 10 100 NS-NS 1000 Frequency [Hz] 10000 3rd generation detectors • Second generation detectors: – Will permit the detection of Gravitational Waves (GW) – Will open the era of the GW astronomy – Will be the “core business” of the next decade in experimental GW research • But can we look beyond? – Precision GW astronomy needs high SNR to determine the parameters of the astrophysical process – Interesting phenomena involves massive bodies that requires low frequency sensitivity in GW detectors – We need to think to 3rd generation GW detectors ILIAS General meeting, Jaca Feb 2008 7 Objectives of a 3 rd generation GW detectors From detection and initial GW astronomy to precision GW astronomy • Fundamental Physics: Test general relativity in the strongly non-linear regime – Initial and advanced detectors won’t have the sensitivity required to test strong field GR (too low SNR) • Most tests are currently quoted in the context of LISA, but in a different frequency range – We need to have good enough SNR for rare BBH mergers which will enable strong-field test of GR • Black hole physics: • – What is the end state of a gravitational collapse? Astrophysics: Take a census of binary neutron stars in the high red-shift Universe – Adv VIRGO/LIGO might confirm BNS mergers, possibly provide links to g-ray bursts – 3rd generation GW detectors could do much more: see different classes of sources (NS-NS, NS-BH) and contribute to resolve the enigma in the variety of g-ray bursts ILIAS General meeting, Jaca Feb 2008 8 How to arrive to an European 3rd generation GW Observatory? • Long preparatory path, already started: – ILIAS played a determinant role: • ILIAS-GW-WP3 realized the correct environment where to discuss, at European level, the evolution of the current detectors and where to merge the efforts addressed to the proposition of a 3rd generation GW observatory – It supported the meetings, the workshops and the preliminary studies – All the ET proposal writing meetings have been supported by WP3 – WP3 has been also the core of the new WG6 (GW) in the ASPERA road-mapping activity • ILIAS-JRA3 (STREGA) partially supported R&D activities in thermal noise issues for 3rd generation GW detectors – European Science Foundation supported an exploratory workshop (Perugia, Sept 2005) that has been a milestone in the definition of the strategy for the proposal of a new Observatory – FP7 Design Study has been the perfect environment where to synthesize our ideas in a proposal and compete with other excellent proposals ILIAS General meeting, Jaca Feb 2008 9 ET • ET: Einstein Telescope – An European 3rd Generation Gravitational Wave Observatory • Conceptual design study proposed at the May 2007 FP7 call – Capacities • Research Infrastructures – Collaborative projects ILIAS General meeting, Jaca Feb 2008 10 ET: Participants Participant no. Participant organization name Country 1 European Gravitational Observatory Italy-France 2 Istituto Nazionale di Fisica Nucleare Italy 3 Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V., acting through MaxPlanck-Institut für Gravitationsphysik Germany 4 Centre National de la Recherche Scientifique France 5 University of Birmingham United Kingdom 6 University of Glasgow United Kingdom 7 NIKHEF The Netherlands 8 Cardiff University United Kingdom ILIAS General meeting, Jaca Feb 2008 11 ET: Status of the project • The proposal passed the first selection and now we are in an advanced negotiation phase • We agreed a budget reduction to 3M€ for 38Months of activity – Main costs: man power and travels • Description of Work document accepted by the European Officer – We are submitting the signed documents to prepare the Grant Agreement – Consortium Agreement under final definition ILIAS General meeting, Jaca Feb 2008 12 Project Coordinator Project organization Scientific Coordinator Secretary WP1 coordinator: Infrastructures WP2 coordinator: suspensions WP3 coordinator: Topology Task responsible Task reponsible Task responsible Task responsible Task responsible Task responsible WP4 coordinator: Astrophysics Task responsible Task responsible ET Project WP5: Management Executive board Governing Council Institutions Science Team Information fluxes Scientific community • Project organization driven by the “Physics”: – 4 working groups are devoted to the major technical and scientific issues – Let see the main technical aspects: ILIAS General meeting, Jaca Feb 2008 13 3 main noise sources 10 -19 10 -20 10 -21 10 -22 10 -23 10 -24 10 -25 1st generation 2nd generation 3rd generation Thermal Noise 1 10 100 ILIAS General meeting, Jaca Feb 2008 1000 10000 14 Thermal Noise • Long interferometer arms 3 main noise sources • Cryogenic optics 1st generation 2nd generation 3rd generation • Large beams, large optics -19 10 • Improved coatings • Non-gaussian beams 10 -20 10 -21 10 -22 10 -23 Thermal Noise •Long interferometer arms • Cryogenic optics •Large beams, large optics 10 -24 10 -25 • Non-gaussian beams 2nd generation 10km • Improved coatings 1 10 100 ILIAS General meeting, Jaca Feb 2008 1000 10000 15 Cryogenic Optics • Test masses and suspensions thermal noise reduces at low temperature: <X2> ~ T • Thermoelastic noise of the mirror substrates and coatings decrease: <X2> ~ α T2 – Thermal expansion rate a decreases at low temperature; • Mechanical Q of some materials increases at low temperature • Thermal lensing: – Thermal conductivity increases and consequently reduces thermal gradients on the coating; – Refraction index variation with temperature is very small at low temperature; (Sapphire @ 20K β = 9 × 10−8, Fused Silica @ 300K β ~ 10−6) ILIAS General meeting, Jaca Feb 2008 16 ILIAS “supported” or related activities Silicon substrates Mechanical loss of coated silicon cantilever R&D activities in many European Labs: Glasgow, INFN Florence & Perugia, Jena University, … -5 3.5x10 Coatings studies 4th mode undoped Ta2O5 4th mode, TiO2 doped Ta2O5 R&D activities in many European Labs: Glasgow, INFN Perugia, LMA-Lyon, MPG Hannover, … -5 3.0x10 -5 2.5x10 -5 2.0x10 -5 1.5x10 -5 1.0x10 0 50 100 150 200 250 300 Temperature (K) Cryogenic Super attenuator R&D activities in INFN Rome & Pisa ILIAS General meeting, Jaca Feb 2008 17 Thermal Noise • Long interferometer arms • Cryogenic optics 3 main noise sources 1st generation 2nd generation 3rd generation • Large beams, large optics -19 10 • Improved coatings • Non-gaussian beams 10 -20 10 -21 10 -22 10 -23 10 -24 10 -25 10km 10km, 20K 1 10 100 ILIAS General meeting, Jaca Feb 2008 1000 10000 18 Thermal Noise • Long interferometer arms • Cryogenic optics 3 main noise sources 1st generation 2nd generation 3rd generation • Large beams, large optics -19 10 • Improved coatings • Non-gaussian beams 10 -20 10 -21 10 -22 10 -23 10 -24 10 -25 10km, 20K, 10cm 1 10 10km, 20K 100 ILIAS General meeting, Jaca Feb 2008 1000 10000 19 Non Gaussian Beams • Thermal noise in a GW interferometric detector could be further reduced by using “flatter” beams: ILIAS General meeting, Jaca Feb 2008 20 Thermal Noise • Long interferometer arms • Cryogenic optics 3 main noise sources 1st generation 2nd generation 3rd generation • Large beams, large optics -19 10 • Improved coatings • Non-gaussian beams • Improved coatings 10 -20 10 -21 10 -22 10 -23 10 -24 10 -25 10km, 20K, 10cm 10km, 20K, 10cm, non gauss 1 10 100 ILIAS General meeting, Jaca Feb 2008 1000 10000 21 3 main noise sources Shot-19 Noise 1st generation 2nd generation 3rd generation 10 • High laser power •(maybe Squeezing -20 1550nm for silicon; 10 • less Longthermal interferometer lensing @ arms 25K) 10 -21 10 -22 10 -23 10 -24 10 -25 800kW Shot Noise 1 10 100 ILIAS General meeting, Jaca Feb 2008 1000 3MW 10000 22 3 main noise sources Shot-19 Noise 1st generation 2nd generation 3rd generation 10 • High laser power • Squeezing -20 10 • Long interferometer arms • Multiple colocated -21 10 interferometers 10 -22 10 -23 10 -24 10 800kW 3MW 3MW, 6dB 3MW, 6dB, 10km -25 1 10 100 ILIAS General meeting, Jaca Feb 2008 3MW, 6dB, 10km, 3ifos 1000 10000 23 Co-located interferometers • “Old” idea still under debate – Possible implementation: 3 detectors in a triangle configuration Rüdiger, ‘85 Antenna Patterns: Credit: Cella, Vicerè Angular response of a standard ITF ILIAS General meeting, Jaca Feb 2008 Angular response of the triangle configuration 24 3 main noise sources 1st generation 2nd generation 3rd generation -19 10 • Underground operation • Homogeneous ‚soil‘ 10 -20 10 -21 10 -22 10 -23 10 -24 10 -25 Seismic 1 10 100 ILIAS General meeting, Jaca Feb 2008 1000 10000 25 Underground operations • LISM: 20 m Fabry-Perot interferometer, R&D for LCGT, moved from Mitaka (ground based) to Kamioka (underground) 10 overall gain • Seismic noise strongly reduced 10 at 4 Hz 2 3 Credit: K.Kuroda ILIAS General meeting, Jaca Feb 2008 26 Seismic Isolation Shortcut Newtonian Noise! ILIAS General meeting, Jaca Feb 2008 Figure: M.Lorenzini 27 Credit: G. Cella Surface waves Newtonian Noise Credit: G. Cella Compression waves credit: G.Cella • Surface waves give the main contribution to newtonian noise Reduction factor (Compression waves not included) Surface waves die exponentially with depth 102 less seismic noise x 104 geometrical reduction NN reduction of 104 @5 Hz with a 20 m radius cave Cave radius [m] 106 overall reduction (far from surface) ILIAS General meeting, Jaca Feb 2008 Credit: G.Cella 28 3 main noise sources 10 -19 10 -20 10 -21 10 -22 10 -23 10 -24 1st generation 2nd generation 3rd generation Ground surface Underground 10 -25 1 10 100 ILIAS General meeting, Jaca Feb 2008 1000 10000 29 Conclusions • The target of the four Working Groups in the ET project is to try to transform these (and many other) ideas in a coherent conceptual design • It is an huge job for a restricted set of persons • ET is an emerging facility for the whole Europe and we don’t want to limit the contribution to the founding team/institutions • The proposal writers created in the project structure a special body that permits the exchange with a larger Scientific Community • The Science Team has been considered extremely important by the project referee and already promoted the Governing Council interest of European and extraEuropean Scientists Institutions • If you are interested, please, contact us ILIAS General meeting, Jaca Feb 2008 ET Project Executive board Science Team Scientific community 30 Comments • ILIAS-N5 played a fundamental role in building-up the framework where ET project is born • ILIAS-JRA3 partially supported the technological development needed to “think” to ET • ET is a conceptual design, with any R&D support: – It needs a further support from the ILIAS (-next) community ILIAS General meeting, Jaca Feb 2008 31 Conclusions: Planning You are here ´06 ´07 ´08 ´09 ´10 ´11 ´12 ´13 ´14 ´15 ´16 ´17 ´18 ´19 ´20 ´21 ´22 Virgo Virgo+ GEO Advanced Virgo GEO HF LIGO Hanford Livingston Advanced LIGO LIGO+ LISA E.T. Launch Transfer data DS PCP ILIAS General meeting, Jaca Feb 2008 Construction Commissioning data 32