Harald Lück AEI Hannover

Thank you Science Team! You did a great job!

The overall idea 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 targets 2.Available technologies (detector realization) 3.Infrastructure & site costs 1.Infrastructure & site costs 2.Available technologies (detector realization) 3.Science targets As a starting point of our studies we defined two rough requirements: Improving the advanced sensitivities by a factor 10 Extend sensitivity to the 1-10Hz frequency range Aim for routine gravitational wave astronomy

The goal

A bit of history  The ET design study is neither the first step nor the last one of the ET adventure  The first successful pan-European GW project towards the 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 (Chaired by M.Punturo and H.Lück)

The Design Study goal  Show that it is conceptually possible to build an observatory 10 times more sensitive than the „advanced“generation

Contributors to the DS  The conceptual design study is supported by the European Union within FP7 with about 3M€ Einstein Telescope 7 Participant Country EGO Italy France INFN Italy MPG Germany CNRS France University of Birmingham UK University of Glasgow UK Nikhef NL Cardiff University UK Science team total: ca. 250

ET will be a long lasting (decades) infrastructure Only mature techniques are foreseen as baseline design Subsequent upgrades to novel techniques will follow ET will be built underground Overall tunnel length will be 30km ET will be built in a ‘triple Michelson’ arrangement ET will use `Xylophone`detectors

Antenna pattern simple Michleson vs. triple Michelson Freise et al. Freise et al. DOI /s

ET will be a long lasting (decades) infrastructure Only mature techniques are foreseen as baseline design Subsequent upgrades to novel techniques will follow ET will be built underground Overall tunnel length will be 30km ET will be built in a ‘triple Michelson’ arrangement

ParameterET- High Frequency ET – Low Frequency Arm length10 km Input power500 W3 W Arm Power3 MW18 kW Temperature290 K10 K Mirror materialFused SilicaSilicon Mirror diameter x thickness 620 mm x 300 mm >450 mm dia. Mirror masses200 kg211 kg Laser Wavelength 1064 nm1550 nm SR- PhaseTunedDetuned (0.6 rad) SR Transmittance10%20 % Beam shapeLG33TEM00 Beam Radius72 mm90 mm SuspensionShort SA 8mSA 17m ‘Xylophone’: cool & hot 20K300K

‘Xylophone’ parts

Xylophone parameters

Suspension Upscaled Virgo SA are up to the isolation task  SA height = 17m for ET-LF (8m for ET-HF)

Squeezing

Filter cavities

Noise Budget

The site  Many site conditions measured in Europe and compared to data from abroad

The infrastructure

For efficiency reasons build a triangle. Start with a single xylophone detector.

For efficiency reasons build a triangle. Start with a single xylophone detector. Add second Xylophone detector to fully resolve polarisation.

For efficiency reasons build a triangle. Start with a single xylophone detector. Add second Xylophone detector to fully resolve polarisation. Add third Xylophone detector for redundancy and null-streams.

Costs  The true answer: it depends  The estimate in the DS document:

24 1st Generation 2nd Generation 3rd Gen.´06´07´08´09´10´11´12´13´14´15´16´17´18´19´20´21´22´23´24´25Virgo GEO LIGO E.T. Hanford Livingston DSPCP Construction Comm. data Site Prep. Virgo+ E-LIGO Advanced Virgo GEO 600 Advanced LIGO Detection Phase Rare Observation Routine Observation You are here

The GWIC roadmap

 … one of the “Magnificent Seven” on the ASPERA roadmap  … on the GWIC roadmap  … has to get on the ESFRI roadmap 26 The EINSTEIN TELESCOPE KM3NET CTA AUGER -N Einstein Telescope 1 ton dark matter 1 ton neutrino mass Megaton proton decay

The Future

28 1st Generation 2nd Generation 3rd Gen.´06´07´08´09´10´11´12´13´14´15´16´17´18´19´20´21´22´23´24´25Virgo GEO LIGO E.T. Hanford Livingston DSPCP Construction Comm. data Site Prep. Virgo+ E-LIGO Advanced Virgo GEO 600 Advanced LIGO You are here ESFRI RM

Einstein Telescope