The Einstein Telescope project
description
Transcript of The Einstein Telescope project
The Einstein Telescope projectMichele PunturoINFN Perugia and EGOOn behalf of the ET Design Study Teamhttp://www.et-gw.eu/
1Einstein Telescope
The Einstein Telescope project aims to the realization of a third generation of GW observatory
The Einstein Telescope
Einstein Telescope2
Participant Country
EGO ItalyFrance
INFN Italy
MPG Germany
CNRS France
University of Birmingham UK
University of Glasgow UK
Nikhef NL
Cardiff University UK
The Einstein Telescope project aims to the realization of a third generation of GW observatory
The Einstein Telescope project is currently in its conceptual design study phase, supported by the European Community FP7 with about 3M€ from May 2008 to July 2011.
The target of this design phase is to understand the feasibility of a new generation of GW observatory that will permit to gain one order of sensibility
The main deliverable, at the end of these 3 years, will be a conceptual design of such as infrastructure
GW Astronomy ?
visibleInfrared
408MHz WMAP
X-ray g-ray
GRB
GW ?
Current e.m. telescopes are mapping the Universe in all the wavelengths detectable from the Earth and from the space.
Gravitational wave telescopes, having a comparable sight distance, could complement the e.m. observation opening the GW astrophysics era
Thanks to the small interaction between graviton and the matter , GW are the best messenger to investigate the first instants of the Universe
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GW interferometer past evolutionEvolution of the GW detectors (Virgo example):
2003
Infrastructure
realization and
detector assembling
2008
Sameinfrastructure
Proof of the working principle
Commissioning
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Upper Limit physics
GW interferometer present evolutionEvolution of the GW detectors (Virgo example):
2003
Infrastructure
realization and
detector assembling
2008
Sameinfrastructure
Proof of the working principle
Upper Limit physics
2011
enhanceddetectors
Sameinfrastructure
Test of “advanced” techsUL physics
2017
Sameinfrastructure
Advanced
detectors
First detection
Initial astrophysics
Commissioning
& first ru
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3rd generation?Evolution of the GW detectors (Virgo example):
2003
Infrastructure
realization and
detector assembling
2008
Sameinfrastructure
Proof of the working principle
Upper Limit physics
2011
enhanceddetectors
Sameinfrastructure
Test of “advanced” techsUL physics
2017Same
infrastructure
Advanced
detectors
First detection
Initial astrophysics
2022
SameInfrastructure
(20 years old for Virgo, even more for LIGO & GEO600)
Commissioning
& first ru
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Precision Astrophysics
Cosmology ?
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Limit of the current infrastructures
Physics Beyond Advanced Detectors GW detection is expected to occur in the advanced detectors. The 3rd generation will focus
on observational aspects: Astrophysics:
Measure in great detail the physical parameters of the stellar bodies composing the binary systems NS-NS, NS-BH, BH-BH Constrain the Equation of State of NS through the measurement
of the merging phase of BNS of the NS stellar modes of the gravitational continuous wave emitted by a pulsar NS
Contribute to solve the GRB enigma Relativity
Compare the numerical relativity model describing the coalescence of intermediate mass black holes
Test General Relativity against other gravitation theories Cosmology
Measure few cosmological parameters using the GW signal from BNS emitting also an e.m. signal (like GRB)
Probe the first instant of the universe and its evolution through the measurement of the GW stochastic background
Astro-particle: Contribute to the measure the neutrino mass? Constrain the graviton mass measurement 7
Einstein Telescope
Targets of the Design StudyEvaluate the science reaches of ETDefine the sensitivity and performance requirements
Site requirementsInfrastructures requirementsFundamental and (main) technical noise requirementsMultiplicity requirements
Draft the observatory specsSite candidatesMain infrastructures characteristicsGeometries
Size, L-Shaped or triangularTopologies
Michelson, Sagnac, …Technologies
Evaluate the (rough) cost of the infrastructure and of the observatory
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2009
2010
2011
Transversal Writing Team
EGO STAC (May 2010) 9
TWT
How to go beyond the 2nd generation?
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10-25
10-16
h(f)
[1/s
qrt(H
z)]
Frequency [Hz]1 Hz 10 kHz
Seismic
Thermal Quantum
Seism
ic
NewtonianSusp. ThermalQuantum
Mirror thermal
3rd generation ideal target
Stressing the current technologies
Obviously a certain improvement of the sensitivity of the advanced detectors could be achieved by stressing the “current” technologies:High power lasers (1kW laser, shot noise reduction)Larger mirrors and larger beams (lower thermal noise)Better coatings (lower thermal noise, lower scattering)
But these aren’t the key elements justifying:the transition 2nd 3rd generationthe need of a new infrastructure
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3rd generation Technologies in ETInjection of squeezed light states (where the phase noise
in the ifo arms is lowered at the cost of the amplitude noise) permits to reduce HF noise
Higher order modes (LG33) resonating in the FP cavities permit to reduce the intermediate (thermal) noise effects
Cryogenic operative temperature (~10-20K) permits to suppress the thermal noise and improve the low and intermediate frequency sensitivityNew materials: Sapphire (LCGT), Silicon New coatings
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Access the very low frequencyThe most challenging requirement of a 3rd generation
GW observatory is to access, as much as possible, the ~1-10Hz frequency range
The “enemy” to fight is the seismic noise, that acts on the test masses1) Indirectly, through the suspension chain2) Directly, through the so-called gravity gradient noise
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Virgo has implemented a seismic filtering chainThe super attenuator (SA)It has been evaluated (S. Braccini et al, 2010) to be compliant
with the ET requirements, above 3Hz, if xseism<510-9/f2 m/Hz-1/2 and hSA~20m
Underground siteVirgo SA filtering capabilities are compatible with the ET
requirements from 3Hz, provided that xseims< 5×10-9/f2 m/Hz½ (Kamioca underground site specs)
Surface wave GGN reduced going underground (G.Cella 2009)
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We need an underground site: new infrastructure!
Measurements in Europe:
BFO (Black Forest Observatory): -162mBRG (Berggieshübel seism Observatory): -36mGRFO (Graefenberg borehole station): -116m
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Peterson’s Low Noise Model
Peterson’s High Noise ModelSite Investigation
http://www.et-gw.eu/
Credits: J.v.d.Brand
The infrastructurePictorial view
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~100
m
The infrastructureSchematic view
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Full infrastructure realized Initial detector(s)
implementation1 detector (2 ITF)Physics already possible
in coincidence with the improved advanced detectors
Progressive implementation 2 detector (4 ITF) Redundancy and cross-
correlation Full implementation
3 detector (6 ITF)Virtual interferometry2 polarizations
reconstruction
Cred
its: S
. Hild
ET TimelineThe t0 depends on several constrains:
Readiness of the project (completion of the design studies)Detection of GW in Advanced detectors (~2017?)Formal decisions…
We suppose to have a construction t0=2018, having a decision t0’=2016-2017
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Site prepara
tion
Site excavation
and realization
Vacuum plants
installation
First detector
installation
Pre-commissioning
and commissioning
2016 2018 2022 20242020
2nd detector
installation
ET Timeline
ASPERA-SAC, Apr2010 19
ET Design
ILIAS-next
ET 2nd DS
ET Prep. phase?
FP7 FP8?
ET Design Study: 2nd phaseWe need maintain active the network between the
scientists that currently are involved in ET, after the end of the DS
We need to pass from the conceptual design (“is it feasible?”) to the technical design (“how it should be realized?”)
Possibility to submit a new proposal to EU in 2010Who?
Enlarge the beneficiaries listWhat?
Content of the proposal Targets
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ConclusionsThe Einstein Telescope
project is concluding its first phaseWe have been able to
group a large community around a new idea
The effort and the continuity on this target must increase in the next years, although the advanced detectors realization will absorb a large fraction of the GW community resourcesOther large research
infrastructures are currently competing for the same budget
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