Michele Punturo. ET scientific Coordinator. INFN Perugia and EGO On behalf of the ET design study team

Transcription

1 Michele Punturo ET scientific Coordinator INFN Perugia and EGO On behalf of the ET design study team

2 Talk Outline A 3 rd generation GW Observatory? Motivations Site and Infrastructures Technologies Perspectives Astro-GR@Mallorca 2

3 Sathya will describe the ET science reaches. Here I will try to demonstrate why we need a new Infrastructure Astro-GR@Mallorca 3

4 Motivations Current (lack of) understanding of the Universe Multi-messenger observation! To re-compose a photograph of the Universe we need to observe it with several eyes (or ears ): E.M. astronomy Neutrino astronomy Cosmic rays Gravitational waves Astro-GR@Mallorca 4

5 E.M. Astronomy Current e.m. telescopes are mapping almost the entire Universe Keywords: Map it in all the accessible wavelengths 408MHz Arecibo VLA Radio Telescopes 5

6 E.M. Astronomy Current e.m. telescopes are mapping almost the entire Universe Keywords: Map it in all the accessible wavelengths 408MHz WMAP WMAP (Microwaves telescope) Plank (Satellite) 6

7 E.M. Astronomy Current e.m. telescopes are mapping almost the entire Universe Keywords: Map it in all the accessible wavelengths 408MHz WMAP Infrared E-ELT (infrared telescope) 7

8 E.M. Astronomy Current e.m. telescopes are mapping almost the entire Universe Keywords: Map it in all the accessible wavelengths 408MHz WMAP Infrared visible VLT (Very Large Telescope) Galileo s telescope Astro-GR@Mallorca 8

9 E.M. Astronomy Current e.m. telescopes are mapping almost the entire Universe Keywords: Map it in all the accessible wavelengths 408MHz WMAP Infrared visible X-ray γ-ray Fermi (GLAST) telescope GRB 9

10 E.M. Astronomy Current e.m. telescopes are mapping almost the entire Universe Keywords: Map it in all the accessible wavelengths See as far as possible Galaxy UDFy in Ultra Deep Field image (Hubble Telescope) 13.1 Gly Infrared 408MHz visible WMAP X-ray γ-ray M. Trenti, Nature 467, (21 October 2010) GRB 10

11 GW Astronomy? Enlarge as much as possible the frequency range of GW detectors Pulsar Timing Arrays Hz Space based detectors (LISA, DECIGO) Hz Ground based detectors Hz Improve as much as possible the sensitivity to increase the detection volume (rate) and the observation SNR Infrared X-ray 408MHz visible WMAP γ-ray GW? GRB Astro-GR@Mallorca 11

12 GW interferometer past evolution Evolution of the GW detectors (Virgo example): Proof of the working principle Upper Limit physics Infrastructu re realization and detector assembling 2003 Same infrastructure 2008 Detection distance (a.u.) year 12

13 GW interferometer present evolution Evolution of the GW detectors (Virgo example): Proof of the working principle Upper Limit physics Infrastructu re realization and detector assembling enhanced detectors Same Same Same infrastructure infrastructure infrastructure First detection Initial astrophysics Detection distance (a.u.) year

14 Advanced detectors Advanced detectors are, for example, promising: An increase of the BNS detection distance up to 200 MPc Enhanced LIGO/Virgo+ arxiv: v2 [astro-ph.he] Virgo/LIGO 10 8 ly Adv. Virgo/Adv. LIGO Universe in 1 Gly Astro-GR@Mallorca Credit: R.Powell, B.Berger 14

15 Advanced detectors Advanced detectors are, for example, promising: An increase of the BNS detection distance up to 200 MPc Enhanced LIGO/Virgo+ Virgo/LIGO 10 8 ly One order of magnitude is missing to compete/collaborate with e.m. telescopes at all the distances Universe in 1 Gly Adv. Virgo/Adv. LIGO Astro-GR@Mallorca Credit: R.Powell, B.Berger 15

16 3 rd generation? Precision Astrophysics Evolution of the GW detectors (Virgo example): Proof of the working principle Upper Limit physics Infrastructu re realization and detector assembling 2003 Same Same Same Same Infrastructure infrastructure infrastructure infrastructure ( 20 years old for Virgo, even more for LIGO & GEO600) 2008 Limit of the current infrastructures First detection Initial astrophysics enhanced detectors 2011 Cosmology Detection distance (a.u.) year 16 Astro-GR@Mallorca

17 Target Sensitivity Target sensitivity of a new, 3 rd generation observatory (the Einstein Telescope, ET) is the result of the trade off between several requirements 1. Science Infrastructure targets & site costs 2. Available technologies (detector realization) 3. Infrastructure Science targets & site costs As starting point of our studies we defined two rough requirements: Improvement by a factor 10 the advanced sensitivities Access, as much as possible, to the 1-10Hz frequency range Astro-GR@Mallorca 17

18 A bit of history The ET design study is neither the first step nor the last one of the ET adventure The first successful attempt to setup a common path toward a pan-european GW project of 3 rd generation has been the I3 initiative ILIAS ( ), in FP6: STREGA (JRA3), thermal noise reduction beyond advanced detectors N5-WP3, future pan-european projects The right framework about the ET proposal born with the support of the European Science Foundation (ESF) Exploratory Workshop (2005, Perugia) Astro-GR@Mallorca 18

19 Achievements of the Design Study Evaluate the science reaches of ET Define the sensitivity and performance requirements Site requirements Infrastructures requirements Fundamental and (main) technical noise requirements Multiplicity requirements Draft the observatory specs Site candidates Main infrastructures characteristics Geometries Size, L-Shaped or triangular Topologies Michelson, Sagnac, Technologies Evaluate the (rough) cost of the infrastructure and of the observatory 19

20 Conceptual Design Document ET conceptual design document released: ~400 pages describing the main characteristics of the observatory To be sent to the European Commission at the end of September To be published on CQG 20

21 How a new infrastructure (and new technologies) pushes ET beyond the 2 nd generation? Seismic h(f) [1/sqrt(Hz)] Hz Frequency [Hz] 10 khz Astro-GR@Mallorca 21

22 Seismic noise Virgo and advanced Virgo seismic filtering is already close to the top of the possible performances Longer suspensions to facilitate the low frequency access Gravity gradient noise bypasses the seismic filtering NEWTONIAN NOISE SEISMIC NOISE G h ρ f const x f H( f) 0 ( ) =. 0( ) Astro-GR@Mallorca Credit M.Lorenzini 2 22

23 Seismic noise Virgo and advanced Virgo seismic filtering is already close to the top of the possible performances Gravity gradient noise bypasses the seismic filtering The only way to access the 1-10Hz range, i.e. appealing for IMBH, is to select a site with very low seismic noise We need to minimize Seismic noise Gravity Gradient Noise Environmental noises (wind, human activities, ) Astro-GR@Mallorca 23

24 Seismic noise model Peterson's background noise model 24

25 Current GW detectors seismic noise µ-seism in a very noisy day Astro-GR@Mallorca 25

26 The ET idea The main limitation for another jump of factor of 10 in sensitivity is then the infrastructure Where is it located? What needs to be realized? When? To go beyond the infrastructure limitation, at low frequency, there are three possibilities: 1. Go in the space 2. Go on the Moon 3. Go underground!!! LISA, DECIGO Crazy (up to now) LCGT, ET 26

27 Seismology network In ET we started the investigation using the support and the data of the ORFEUS* Network (>200 sites in Europe) * Observatories and Research Facilities for European Seismology Astro-GR@Mallorca 27

28 ET: Site search Underground sites (mines, labs, ) Seismometer (Nikhef) Astro-GR@Mallorca 28

29 WP1: Site search: Many sites visited in Europe 29

30 Underground Seismic noise Measurement 30

31 Day/Night variability vs population density 31

32 Site selection Single site selection was not one of the targets of the conceptual design study Our objective has been to define the requirements to understand the relationship between site characteristics, costs and performances To prepare a list of good candidates The selection of the site will be performed in a future phase and the scientific and technical arguments will be joint to the political and financial aspects Astro-GR@Mallorca 32

33 ET infrastructure: the keywords During the ET conceptual design study period we developed a new jargon For initial and advanced interferometer the right keyword is detection and these apparatuses are named detectors. ET aims to observe the GW sources and the keywords are different The target is an infrastructure operating for many decades with high duty cycle ET must be able to observe a wide range of frequencies ET must be able to host more than one detector (multiplicity) and accommodate the future evolutions, minimizing the suspension of the data taking (modularity) ET will operate embedded in a world wide network, but it should have scientific relevance if working alone (rough pointing capabilities, high SNR) Hence, ET will be an observatory (rather than a detector) Astro-GR@Mallorca 33

34 Implementing the infrastructure Schematic view Full infrastructure realized Initial detector(s) implementation 1 detector (2 ITF) Physics already possible in coincidence with the improved advanced detectors Progressive implementation 2 detector (4 ITF) Redundancy and crosscorrelation Full implementation 3 detector (6 ITF) Virtual interferometry 2 polarizations reconstruction Astro-GR@Mallorca 34

35 Artistic/Schematic views 35

36 Corner and ancillary halls 36

37 ~30km of Gilgel Gibe II Power Station headrace tunnel Şanlıurfa Irrigation Tunnels Kanayama-Nagoya Dome-mae Yada-Kanayama (Meijo Line) Hakkōda Tunnel(Tōhoku Shinkansen) tunnels? LEP Tunnel Dainichi-Nagahara (Tanimachi Line) Morden - East Finchley (Northern Line) Under Taihang construction Tunnel[4] or advanced plan Guadarrama Tunnel[3] Förbifart Stockholm[29] Fehmarn Belt Fixed Link Follo Line Musil Tunnel[27] Gaoligongshan Tunnel Mont d'ambin base tunnel Brenner Base Tunnel Marmaray Ceneri Base Tunnel Solan Tunnel[26] Mavi Tünel (Blue Tunnel)[25] Iiyama Tunnel[24] Pajares Base Tunnel Lainzer/Wienerwaldtunnel New Guanjiao Tunnel Koralm Tunnel Gotthard Base Tunnel New York City Water Tunnel#3 Prospekt Veteranov - Devyatkino (line 1) Parnas - Kupchino (line 2) Côte-Vertu - Montmorency (Line 2 Orange) Rathaus Spandau-Rudow (U7) Metro Madrid L-7: Hospital del Henares - Pitis Lötschberg Base Tunnel Medvedkovo - Novoyasenevskaya (line 6) Quabbin Aqueduct Kárahnjúkar Hydroelectric Powerplant Tocho-mae - Shiodome - Hikarigaoka (Toei Oedo Metro Madrid L-12: (Metro Sur) Altufyevo - Bulvar Dmitriya Donskogo (line 9) Seoul Subway: Line 5 Channel Tunnel Želivka Water Tunnel[2] Seikan Tunnel Bolmen Water Tunnel Orange Fish River Tunnel Dahuofang Water Tunnel Päijänne Water Tunnel Delaware Aqueduct Astro-GR@Mallorca

38 ET: The technologies Seismic h(f) [1/sqrt(Hz)] Hz Frequency [Hz] 10 khz Astro-GR@Mallorca 38

39 Reduction of the thermal noise Thermal noise reduction is achievable through two handles Fluctuation dissipation theorem: Minimization of the mechanical losses in the (suspension and test mass) material and optimization of the suspension geometry Equipartition theorem: reduction of the thermal energy (low temperatures) Advanced detector are fully exploiting the first handle Third generation will benefit (as LCGT intends to do) of the second one: Cryogenics 39

40 Cryogenic plants and technologies A cryogenic design of the payload has been investigated in the design document Conceptual solutions identified but intense R&D needed for the next years Silicon optics Cryo-cooling techniques Coatings Astro-GR@Mallorca 40

41 Synergies with LCGT: ELiTES LCGT is pioneering the development of an underground infrastructure and of the cryogenic interferometer for GW detection We considered mandatory to profit of all the collaboration possibilities At the beginning of 2011 has been submitted a FP7-European proposal (ELiTES) for a 4 years exchange of scientist programme between Europe (ET-Science Team laboratories) and Japan (ICRR-UT)focused on cryogenics The proposal has been evaluated positively and now we are in the negotiation phase Astro-GR@Mallorca 41

42 Optical Configuration Optical topologies have been investigated in the design study Different geometries analyzed Compliance with the observatory keywords has been the crucial requirement 42

43 Optical Technologies Reduction of the quantum noise asks for new technologies to be developed in ET 1.55µm lasers, High power lasers Low absorption silicon and fused silica optics Higher mode cavities Frequency dependent squeezing Thermal compensation improvements 43

44 ASPERA tech forum A first small step to support the optical technology development for ET Astro-GR@Mallorca 44

45 ET as European Research Infrastructure ET is candidate to be a major infrastructure, fundamental brick of the European Research Area To transform this wish in reality, several achievements are needed The successful conclusion of the conceptual design phase, the enthusiastic participation of many scientists, well beyond the 8 beneficiaries, the international relevance achieved in these three years are a confirmation of the validity of the project and a good starting point But a long path is in front of us: Astro-GR@Mallorca 45

46 The worldwide scenario ET project is obviously fully immersed in the worldwide evolution of the GW detectors GWIC roadmap: 46

47 ET Conceptual design R&D Technical design First detection on advanced interferometers ET Site and infrastructures realisation ET Observatory Funding Site preparation Hardware production Components pre-commissioning and first ET detector commissioning First science data

48 END 48