1 / 28

DPG spring meeting, March 2011

The AEI 10m Prototype Interferometer. Tobias Westphal for the AEI 10 m Prototype team. http://10m-prototype.aei.uni-hannover.de. DPG spring meeting, March 2011. Why to build another PT. Ultra-low displacement-noise test environment To probe at and beyond the Standard Quantum Limit (SQL)

quail-johns
Download Presentation

DPG spring meeting, March 2011

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The AEI 10m Prototype Interferometer Tobias Westphalfor the AEI 10 m Prototype team http://10m-prototype.aei.uni-hannover.de DPG spring meeting, March 2011

  2. Whytobuildanother PT • Ultra-low displacement-noise test environment • To probe at and beyond the Standard Quantum Limit (SQL) • equivalent Heisenberg limit for 100g test masses • Thermal noise interferometer • Other experiments within QUEST (for e.g. LISA or GRACE follow on) • Entanglement of macroscopic test masses (a bit further down the road…) Maximal overlap with GEO-HF subsystems • Develop and prove as many of the techniques needed for gravitational wave detector upgrades as possible (e.g. laser, digital control infrastructure) • Provide training for people who will install upgrades to and run GEO-HF

  3. Whatisthe SQL

  4. SQL interferometerlayout Optional: Signal recycling ~8W @ 1064nmfibercoupled 10m Fabry-Perot arm cavity Finesse ca. 700 Tap off ~130mW Optional: Power recycling Frequency referencecavity Length: 12m Finesse: ca. 7500 Triplependulumsuspension Mirror mass: 860g 100g Mirrors monolithicsilicasuspensions Anti-resonant Fabry-Perotcavity as compound end mirror

  5. Squeeze-in tanks Learnfromexperience! Earlierdays (GEO600 design): Not very versatile REALLY uncomfortable towork in

  6. Walk-in tanks 100mm flanges to fit feedthroughs 600mm flanges to fit viewports Walk-in door 100mm flanges to fit feedthroughs

  7. Ultra-high vacuum system Tubes: 1.5m Ø Tanks: 3.4m tall 3m Ø 10-6mbar after about 12 hours • 100m³ Volume • 22t stainlesssteel • 170l/s screw pump (roughing) • 2x 2000l/s turbo pump (main) • 2x scroll pump (backing & differential) • Metalgasketsbelow 600mm • Double O-ring differentiallypumped

  8. Slicedopen Optical benches in thetanks Passive seismicisolation Activeintertablestabilisation

  9. Table subsystems Inverted pendulum Accelerometer Geometric antispring Vertical motorized blade Optical table Filter support Base plate LVDT / Actuator Tilt stabilisation Horizontal motorized blade

  10. GAS filter (verticalisolation) Top view Side view Featuring very soft potential → large isolation Huge loading capabilities

  11. Estimated motion micro-seismic anthropogenic 60dB 70dB

  12. Vertical isolation (measured) ← GAS-resonance frequency ca. 440mHz without magic wand off-centered accelerometer 7dB shaker structure

  13. GAS filter shaker

  14. GAS filter in action

  15. Estimated differential motion Inter table Activeisolation Passive isolation

  16. Low freqency active isolation Stabilized intertable Activeisolation Passive isolation SPI Accelerometers LVDT`s

  17. Suspension platforminterferometer Goal: Stabilize inter table motion 100pm/√Hz, 10nrad/√Hz @ 10mHz Based on LISA Pathfinder experience: Heterodyne Mach-Zehnder interferometer with unequal arm length (by 23m) Iodine-stabilised Nd:YAG (frequency noise) Optics bonded onto low CTE plate (thermal drifts) Digital signalprocessing (FPGAs)

  18. Digital controlsystem • Analog world • Digital world • User world • Giveserrorsignals • Carriesactuation out • Changes • Getdata Experiment Sensors & actuators Front-end Digital filters Workstation ADC/DAC 6 x 32channel PCI-X DA/AD & DIO Fieldboxes Signal conditioning AA/AI filters GPS timing Frame builder Storage Based on realtime LINUX Runs EPICS software

  19. Laser: 35W @ 1064nm 99% in TEM00 Pump diode: • 808nm, 45W • 400µm Øfiber coupled,NA=0,22 24W measurement TEM00 model Amplifier: • 38W for 2W seed and 150W pump Normalized power Frequency [FSR] Crystals: 3 x 3 x 10mm3 Nd:YVO4 8 mm 0,3% doped, 2mm endcap

  20. Mirrorsuspensions Frequency reference cavity: Three horizontal, two vertical stages 850g per stage (mirror 10cm x 5cm) Steel wires, last stage 55µm Ø Local control and alignment control at uppermost stage (fast alignment is done at steering mirrors) Interferometer optics: Three horizontal stages, two vertical stages 100g per stage (mirror ca. 2“ x 1“) All silica last stage, 4 filaments of 20µm Ø

  21. Sensitivity w/o Khalilicavities

  22. Where does coating noise appear? Coating noise Reflectivity N N • High reflectivecoatingshave lots ofcoatinglayers • Few layers  medium R, low CTN • Many layers  high R, high CTN • Let‘s separate reflectivity and losses!

  23. Khalili cavity IETM EETM (2n+1) l/2 • One HR mirrortwomirrors: • Medium reflectivity: ca. 50% (IETM) • High reflectivity: 99.99% (EETM) • Factor 1.6 reductionofcoating thermal noise

  24. Sensitivity w/o Khalilicavities

  25. SensitivitywithKhalilicavities

  26. Sensitivitywithdoping & Khalili • Titanium

  27. The team http://10m-prototype.aei.uni-hannover.de • Ken Strain: Scientific leader • Stefan Goßler: Coordinator • Gerhard Heinzel: LISA/LPF related experiments • Yanbei Chen, KentaroSomiya, Stefan Danilishin: Experiment design, noise analysis • Roman Schnabel: Squeezing and QND experiments • HaraldLück: Vacuum system and GEO 600 related experiments • Hartmut Grote: Electronics and GEO 600 related experiments • GEO operators: Filter design and construction, environmental monitoring • Andreas Weidner: Electronics design • KasemMossavi: Vacuum system and pumps control • Jens Breyer: Mechanical design • BennoWillke, Jan HendrikPöld, Christina Bogan: High power laser • GerritKühn, Michael Born, Martin Hewitson: Real time control system • Alessandro Bertolini, Alexander Wanner: Isolation tables • Katrin Dahl: SPI • Fumiko Kawazoe: Frequency reference cavity • Stefan Hild, Sabina Huttner, Christian Gräf:Interferometric sensing & control • Giles Hammond, Tobias Westphal: Monolithic suspensions • Gerald Bergmann: Commissioning See poster Christian Gräf Q57.83 16:30

More Related