The AEI10 m prototype interferometer

Stefan Goßler for the 10 m prototype team

DPG, March 2009

203.03.2009 The AEI 10 m prototype interferometer

Purpose of our prototype

Ultra-low displacement noise test environment to probe at and beyond the Standard Quantum Limit (SQL)

for of order 100 g to kilogram scale masses

Maximal overlap with GEO-HF subsystems develop and prove as many of the techniques needed for GEO 600

upgrades as possible (e.g. laser, digital control infrastructure) provide training for people who will install and run GEO-HF

303.03.2009 The AEI 10 m prototype interferometer

Vacuum system

Roughing: One 170 l/s screw pumpMain pumps: Two 2000 l/s turbo-molecular pumps

Backing and differential pumping: Two scroll pumps10-6

mbar after about 12 hours

Tanks:3 m diameter, 3.4 m tall

Tubes:1.5 m diameter

Volume ca. 100 m3 22 t stainless steel

403.03.2009 The AEI 10 m prototype interferometer

In the prototype hall

180° view

503.03.2009 The AEI 10 m prototype interferometer

603.03.2009 The AEI 10 m prototype interferometer

Walk-in tanks

03.03.2009

600 mm flangesto fit viewports

100 mm flangesto fit feed throughs

100 mm flangesto fit feed throughs

703.03.2009 The AEI 10 m prototype interferometer

Isolated optical tables

GAS Filters

Inverted pendulum legs

Experimental platform

See next talk by Katrin Dahl

for full detailsPrototype of passive isolation table at MIT

LASTI HAM-SAS

803.03.2009 The AEI 10 m prototype interferometer

Suspension platform interferometer

Digital signals from FPGAs need custom interface to digital control system

Based on LISA Pathfinder phase meter

Mach-Zehnder interferometer with unequal arm length (by 20 m), requires stable laser to reach design sensitivity of 100 pm/sqrt(Hz) @ 10 mHz: Iodine-stabilised Nd:YAG

Thermal drift requires components to be bonded onto plate with low CTE

See talk by Oliver Kranz

Q31.4 for full details

903.03.2009 The AEI 10 m prototype interferometer

Mirror suspensions

Uppermass

Secondmass

Penultimatemass

MirrorPre-installed suspension

cartridgeMonolithic last stage

100 g mirror, four 20 µm silica fibres

1003.03.2009 The AEI 10 m prototype interferometer

• Crystals: 3 x 3 x 10 mm3 Nd:YVO4 8 mm 0,3 % dot.2 mm undoped endcap

• Pump diode: 808 nm, 45 W400 µm fiber diameterNA=0,22

• Amplifier: 38 W for 2 W seed and 150 W pump

/4

/2

NPRO

Isolator

Nd:YVOcrysta ls

4

pum poptics

/4

/2

NPRO

Isolator

Nd:YVOcrysta ls

4

pum poptics

Light source: 35 W @ 1064 nm

1103.03.2009 The AEI 10 m prototype interferometer

Digital control

Based on real-time Linux system and EPICS software

Experiment

sensors &

actuators

Field box Front end WorkstationExpansionchassis

Timing slave

Timing master

GPS clock

6 x 32 channel PCI-X DA/AD & DIO

Opteron based,64bit real-time Linux

Framebuilder

Fibre link forreal-time network

Signal conditioningAA/AI

Linux,Simulink

based input

10 GHz

1203.03.2009 The AEI 10 m prototype interferometer

Optical layout

Frequency reference cavityLength: 12 m

Finesse: ca. 7500Triple pendulum suspension

Mirror mass: 860 g

10 m Fabry-Perot arm cavityFinesse ca. 700

100 g Mirrorsmonolithic silica suspensions

Optional:Power recycling

~35 W input @ 1064 nmOptional:

Signal recycling

Anti-resonantFabry-Perot cavity

as compound end mirror

Tap off~130 mW

See talk by Fumiko Kawazoe

about reference cavity

Noise budget

1303.03.2009 The AEI 10 m prototype interferometer

1403.03.2009 The AEI 10 m prototype interferometer

The teamKen Strain: Scientific leaderStefan Goßler: CoordinatorKasem Mossavi: Vacuum system and pumps controlJens Breyer: Mechanical designBenno Willke: High power laserGerhard Heinzel: LISA/LPF related experimentsYanbei Chen, Kentaro Somiya, Stefan Danilishin, Henning Rehbein, Helge Müller-Ebhardt: Noise analysis, experiment designRoman Schnabel: Squeezing and QND experimentsHarald Lück: Vacuum system and GEO 600 related experimentsHartmut Grote: Electronics and GEO 600 related experimentsGerrit Kühn, Michael Born, Martin Hewitson: Real time control systemGEO operators: Filter design and construction, environmental monitoring Andreas Weidner: Electronics designHenning Ryll: Laser and fibre-modecleanerKatrin Dahl (PhD), Oliver Kranz (diploma): Suspension platform interferometer Bob Taylor (postdoc): Seismic isolation and controlAlexander Wanner (PhD): Inertial controlFumiko Kawazoe (postdoc): Frequency reference cavity and global controlAlessandro Bertolini: Seismic isolationTobias Westphal (PhD): Monolithic suspensionsChristian Gräf (PhD): RT controlThomas Brockt (Diploma): Power supplies and voltage distributionDaniel Gering (Diploma): Interface Phase Meter - CDS