Frank Linde 19 June 2018 AEI Hannover Before

Frank Linde, 19 June 2018, AEI, Hannover

Before: 2017, prototype plan by AB & Jvd. B 26 January 2018, discussion @ AEI

Prototype studies: ‘mini. ET’ 31 -JAN-2018 R&D laser-interferometers: Caltech, MIT, Glasgow, Hannover, 10 m prototype ‘soft’ issues: • • Liège AEI, Hannover scope of mini. ET Gaining expertise 20 meter long arms Community building 10 M€ (capital) Ties with industry 5 years to build? Focal point many years of R&D! possible R&D focus: • • Sensors & Controls? Large mirrors? ET-like suspensions? Cryogenic systems?

Maastricht Friday, 9 May 2018 11: 15 11: 30 12: 00 12: 30 14: 00 14: 30 introduction relevance of having a prototype for ET (Jvd. B) overview of existing prototype facilities (BS) experiences with the AEI 10 m prototype (HL) technology we can/should test for ET (SH) discussion plus informal & ongoing follow-up discussions

B-D-NL project: ‘ETpathfinder’ 20 meters R&D facility Partners: • Universiteit Antwerpen • KU Leuven • Universiteit Gent • Universiteit Maastricht • Technische Universiteit Eindhoven • Nikhef (lead partner) +1 nm rms 0. 1 nm -1 nm optics cold Satellite partners: 14, 5 M€ • Universiteit Luik only capital • Vrije Universiteit Brussel no manpower • Université Catholique de Louvain partial funding • Fraunhofer Institute for Laser Technology • Rheinisch-Westfälisches Technische Hochschule • More are very welcome! Status: • • 18 May pre-proposal submitted 3 september decision = verdict If ok: full proposal December Final verdict: 3 March 2019 vibration attenuation controls 5

geology inventory – R&D facility next opportunity Liège takes lead (EMR includes Aachen) 6

Present ‘ETpathfinder’ ideas (can R&D facility targeted @: cryogenic silicon optics thermal expansion [K 1] change!) thermal expansion temperature [K] Note: credits notably to Stefan Hild, for any mistakes please blame me 8

Present ‘ETpathfinder’ ideas (can R&D facility targeted @: cryogenic silicon optics thermal conductivity [Wcm 1 K 1] change!) thermal conductivity temperature [K] Note: credits notably to Stefan Hild, for any mistakes please blame me 9

Present ‘ETpathfinder’ ideas (can Central issues: change!) Temperature 10 -20 K 120 K Wavelength 1, 55 m 2. 1 m No fast answers – just take an educated guess? or – go for R&D facility? ETpathfinder: 1. flexible laser-interferometry R&D infrastructure 2. full 10 K compatible infrastructure - start with one arm (FPMI // beams) at 120 K - next other arm (FPMI // beams) at 10 -20 K - allows to explore in parallel 1, 55 & 2. 1 m ETpathfinder possible testbed for ET, LIGO Voyager & Cosmic Explorer 10

Present ‘ETpathfinder’ ideas (can change!) 1 st conceptual design (v 0. 1) Stefan Hild 73 K 4 K 11

Present ‘ETpathfinder’ ideas (can change!) Allows many tests, investigations, etc. • • Cooling down of mirrors of cryogenic temperatures Stable control of mirrors at low temperatures? Thermal compensation? Problems with contamination on mirror surfaces? Attenuation of cryo-system induced vibrations? Suspensions & cryogenic interfaces – do we get it to work? Lots of things I know nothing about … phase noise, … • And probably (hopefully!) even a lot more! E X p E C T E D E T p a t h f i n d e r L I F E T I M E 15 -20 years 12

Next steps • Meetings like this one: expand community/users & collect ideas • Liège people will organize meeting @ CSL (July/August) • Vigorously explore funding opportunities • Cryogenics: • Friday 13 July 2018: discussion with CERN cryo experts • Contacting our Japanese (KAGRA) colleagues (already received € info) • Agree on cleanroom geometry & find a location (funding consraints …) • Explore institutional & industrial contacts • Start realizing R&D facility! 13

Your world You make things with 10 9 meter precision combining optics, mechanics, controls, … 100 M€/piece, ten(s) of units/year Our world We register displacements of 10 18 meters combining optics, mechanics, controls, … 100 M€/piece, few for 30 -40 years each 14