====== Einstein Telescope Design Update ====== [[https://events.ego-gw.it/indico/conferenceDisplay.py?confId=60|Einstein Telescope Design Update Workshop]] at Glasgow, September 2017 {{:et_update_2017:p1080155.jpg?1300|}} ===== Slides From Plenary Presentations ===== * Karsten Danzmann: * David Shoemaker: [[https://dcc.ligo.org/LIGO-G1701783/public | aLIGO experience in the context of ET]] * Sheila Rowan: {{:et_update_2017:et_glasgow_2017_rowan_dcc.pptx|Worldwide co-ordination towards a 3G network}} * Jo van der Brand: * Salvatore Vitale: {{:et_update_2017:slides_svitale.pdf|3G Science overview}} * Michele Punturo: [[https://tds.virgo-gw.eu/ql/?c=12612 | Overview of the ET design and next steps on the ET roadmap]] * Harald Lueck:{{:et_update_2017:gwic_3g_rad_glasgow.pptx|}} * Stefan Hild: {{:et_update_2017:starting-off-discussions.pptx|Slides for starting of discussion}} * Humboldt Foundation (not given due to illness): {{:et_update_2017:2017_07_30_fa_treffen_uni_hannover_in_glasgow_final.pptx|Slides}} * Dr Barden-Lauefer, Dr Huntebrinker: {{:et_update_2017:leibniz_research_alumni_network_glasgow2017_ariel_kompatibilitätsmodus_.pdf|Leibniz University Alumni overview and opportunities}} * Joe Galloway: {{:et_update_2017:gravitational_waves_ejd_presentation.pptx|Slides on ITN, EJD and joint doctorates in general}} ===== GraWIToN ESR presentation award Ceremony ===== All GraWIToN Early Stage Researchers present at the ET update meeting gave a four minute presentation of their PHD project.\\ The best presentation (judged by a jury of supervisors) got a certificate:\\ {{:et_update_2017:p1080179korr.jpg?900|}} ===== Background ===== * [[https://tds.virgo-gw.eu/?call_file=ET-0106C-10.pdf|ET design study]] * ET-D sensitivity data: total sensitivity: {{:et_update_2017:et_d_spectrum.fig|Matlab-figure}}, {{:et_update_2017:et_d_data.mat|Matlab mat}} * ET-D LF noise budget: {{:et_update_2017:etd_lf3.fig|Matlab fig}}\\ * {{:et_update_2017:etd_lf3.png?200|}} * ET-D HF noise budget: {{:et_update_2017:etd_hf3.fig|Matlab fig}}\\ * {{:et_update_2017:etd_hf3.png?200|}} ===== Top level discussions ===== * [[et-lf-still-needed|Still LF the key feature?]] --- Science case difference between 2Hz cut-off and 10Hz cut-off. What will be covered by LISA already? What else to we get from LF apart from BBH? Thomas, David. * Length argument: Infrastructure (ultimate noise limit, long-term capability) vs detector (short term + cheaper)? * Michele: The two things we have to decide within the next two years: Underground or not? And triangular or not? * Is ET a brand? Is it what we want to be? Is it important or a hindrance in global coordination? * Steps needed towards ESFRI roadmap (level of maturity/TDS?) {{:et_update_2017:p1080167.jpg?300|}} ===== List of items to investigate ===== * [[science-case-for-2Hz|Science case difference between 2Hz cut-off and 10Hz cut-off?]] Tomek, David * Lessons learned from KAGRA so far in terms of materials? * Lessons learned from KAGRA so far in terms of sensors and actuators? * What do we lose if we abandon triangular footprint vs longer L? * [[abandoning-xylophone|What do we lose if we abandon the xylophone (because might not be necessary in global network)? What cost reduction to we get?]] Stefan * Tube diameter to small currently for proper scattering mitigation? * [[optimum-length|Optimum arm-length? is there a sweet spot from beam divergence, mirror dimensions available, energy stored in suspensions?]] * What an estimate for the classical noise budget of an 3G detector? (Useful for optimisation) * Is it of any use if a single ET has good LF sensitivity but no other detector has similar sensitivity in this frequency range? * Do we need sky localisation capability? ==== suspension: ==== * Unordered List Itemmodify to two floor design. Con: lose flexibility of infrastructure * a-LIGO pre-isolation and compact SUS. * Warm and cold sensors and actuators. * [[sus-materials-update|up to date list of what is available in terms of materials (sapphire, silicon, composite masses?) today]] Giles, * SPI: options for central ifo? * improvement of seismic sensors, tiltmeters * actuators for minimal cross-coupling (act only in the desired direction) * violin mode sensors and dampers * [[all-sus-modes|think about ALL modes of long suspensions]] Norna * Need to look anew into cryo-suspension techniques. 1.5m last stage. * SPI? ==== optical topology ==== * (Michelson vs speedmeter etc) what is the decision path? decision point can be late as they all fit into the same infrastructure * [[lg33|LG33 availability of optics, TCS, do we need LG33 ? rely on better coatings? review investigations since ET DS.]] Jerome * squeezing higher order modes * [[coatings-update|coatings review]] Stuart, Peter * [[substrates-update|substrates review of materials and performance]] Harald * [[PIs|PIs]] Anna, Andreas, Daniel * [[TCS|TCS]]: Better wavefront sensors, better actuators? Need for TCS in "voyager" design? * alternatives to xylophone design? what do we need? what do we gain? * update options for optics surface, surface figure, scatter. Derive cavity losses (10km) from this * squeezing losses in FC. Actuating BW of FC. Actuating on surface figure of FC to reduce losses and improve MM. * adaptive mode matching * [[et_update_2017:quantum_noise_of_et_lf|quantum noise of ET LF]] Haixing * [[reaching-ce-sensitivity|what parameters do we have to push to get to CE sensitivity?]] Haixing * [[large_beams| problems with increasing beam size]] ==== site and infrastructure ==== * [[site-geology|derive site preference from geology and noise sources (cities)? Is it possible?]] * [[validating-site|minimum set of measurements for validating site. Improve understanding of damping of different materials at sites.]] Michele * cryogenics. Cooling power --> disturbances. liquid He "from above". safety issue? * [[anthropogenic-noise|self made seismic noise: level, counter-measures]] Nikhef * Identify any potential cost savings on vacuum? * facilities for producing large cryo substrates --> GWIC 3G R&D [[6Sept2017|Working group meeting]]: Michele Punturo, Jo v/d Brand, Tamas Novak, Peter Van, Niels van Bakel ==== Others ==== * requirements of calibration accuracy * [[Telecon 6 Oct]] ===== Outcomes ===== * [[Conclusions and Observations of the meeting]] * [[ET telecons]]