AOF Wave front sensor modules GALACSI and GRAAL

AOF Wave front sensor modules GALACSI and GRAAL by Stefan Ströbele in behalf of the GALACSI and GRAAL Team members: R. Arsenault, R. Conzelmann, B. Delabre, R. Donaldson, M. Duchateau, G. Hess, P. Jolley, A. Jost, M. Kiekebusch, M. Lelouarn, P. Y. Madec, A. Manescau, J. Pirard, J. Quentin, R. Siebenmorgen, C. Soenke, S. Tordo, J. Vernet, SPARTA, DSM, 4 LGS, ASSIST, Teams, Integration and IR and CCD detector groups 20 Years AO@ESO 1

GRAAL- GALACSI Comparison parameter GRAAL GALACSI Instrument Hawk-I (IR imager) ESO Muse (VIS 3 D-spectrograph) Lyon Mode Maintenance mode GLAO Wide Field Mode Narrow Field Mode Field of view 10” 7. 5’ 1’ 7. 5” AO mode SCAO GLAO LTAO Performance (S. R. ~ 80% in Kband) x 1. 7 EE gain x 2 EE gain Natural Guide Stars On axis, ~ 8 mag R-mag 14. 5 within 6. 7’ to 7. 7’ radius R-mag <17. 5 within 52” to 105” radius Sky coverage Close to “bright” stars 95% >90% 4 LGSF config. NGS only Ø 12’ Ø 20” WFS 1 NGS L 3 -CCD (40*40 sub app. ) Loop frequency HO loop: ≥ 700 Hz 4 LGS L 3 -CCD (40*40 sub app. ) 1 TT L 3 -CCD HO loop: ≥ 700 Hz TT loop: 250 Hz 4 LGS L 3 -CCD (40*40 sub app. ) 1 TT L 3 -CCD HO loop: 1 k. Hz TT loop: 200 Hz 4 LGS L 3 -CCD (40*40 sub app. ) 1 IR Low Order HO loop: 1 k. Hz LO loop: 200 -500 Hz 20 Years AO@ESO S. R. >5% (10% goal) @650 nm On Axis, NIR, Jmag 15 Low Order sensing Science target = TT reference 2

AO Types • SCAO: – 1 Natural guide star, 1 WFS – WFS measures Turbulence – correction by the DM • GLAO: – 4 Laser guide stars, 4 WFSs – 1 Natural guide star, 1 TT Sens. – Average WFS signal High order DM command + tip tilt meas. • LTAO: – 4 Laser guide stars, 4 WFSs (closer together) – 1 Natural guide star, 1 low order sensor – WFS signal + Tomography Algorithm high order DM command + tip tilt +focus meas. – correction by the DM 4

Altitude [km] 20 Years AO@ESO LGS beam Ø [m] Beam offset [m] GRAAL GALACSI WFM GALACSI NFM LGS at 6’ LGS at 64” LGS at 10” 0 8 0 0 0 1. 4 7. 86 2. 6 0. 5 0. 07 2. 2 7. 8 3. 9 0. 7 0. 1 11. 2 6. 9 - 3. 5 0. 5 16 6. 6 - - 0. 8 5

GRAAL • LGS and NGS pickup outside the science field • HAWK-I co-rotates to the sky • Matching of the WFS – DSM geometries counter rotation of the LGS WFSs • Integration to a existing instrument Strong constraints to space, weight, access, 20 Years AO@ESO interfaces 6

GRAAL big pieces Alustructure NGS-TT sensor assembly LGS trombone LGS WFS assembly bearing Hawk-I shutter Torque drive Steel structure Counterweight Steel flange MCM assembly • Bearing (150 Nm friction / 80 kg) • Torque drive (500 Nm nominal / 70 kg) • Encoder (tape / scanning head) • Cable-guide system (110 kg) • Aluminium structure (75 kg) 20 Years AO@ESO • Steel structure (50 kg) 7

GRAAL as seen from (above) the Nasmyth platform Flange sandwiched between UTNasmyth and Hawk-I Aluminum and steel structure for stiffness and weight constraints ICPs for quick-separation Internal co-rotator for pupil derotation, direct drive in torque mode, strip band encoder, control loop using VLT-SW standard library 1 k. Hz, 0 -noise LGS WFS, optics and trombone focusing on a Ø 500 mm (x 4) Retractable focal enlarger x 6 (maintenance and commissioning), with WFS pick-up 100 kg counterweight to balance 150 kg of electronics

GRAAL arrangement on UT 4 • 2 E-Cabinet on board – (WFS camera electronics) • Uses the HAWK-I cable rotator • Cabinet on the NP – motion control, • Cabinet on Azimuth PF – SPARTA RTC – 5*NGC backend • Cabinet in the computer room – SPARTA cluster 20 Years AO@ESO 9

GRAAL Performance • Image improvement x~2 (EE in 0. 1” pixel), seeing reducer: x 0. 8 (in Ks) • Improvement for all seeing conditions J. Paufique GRAAL FDR, 10/03/2009

MUSE-GALACSI MUSE: – 3 d Spectrograph with 300 by 300 spatial resolution elements – Spectrometer resolution 1500 -3000 – 24 spectrographs with 1 CCD 4096 by 4096 pixels each – Wavelength range: 465930 nm – Developed by consortium lead by CRA-Lyon, PI: R. Bacon 20 Years AO@ESO 11

NGS-LGS Configurations WFM 1’ MUSE FOV 1 faint NGS within 3. 4’ FOV GALACSI –FDR 16 th June 2009 NFM 4 Sodium LGSs Rayleigh cone 12

20 Years AO@ESO 13

Telecentricity lens AIT pupil Focus compensator from VLT Reflects 589 nm transmits the rest to TTS LGS dichroic, LGS WFS path 2 nd Pupil relay Annular Mirror, ( no obstruction for MUSE WFM) LGS dichroic inserted for NFM Pyramid: • LGS separation near LGS focus • On linear stage to switch between modes Pupil relay WFS, LA Jitter actuator 14

GALACSI Main assembly • GALACSI at Nasmyth B UT 4 • 5 E-Boxes on board • 1 Cabinet on NP • 1 Cabinet on AZ P • 2 cable chains AO Facility Review, 24. 08 15

IRLOS • HAWAI –I 1024 x 1024 pixels, 4 quadrant geometry 4 sub aperture lenslet array • Frame rate 200/500 Hz for 20 by 20/8 by 8 pix RON <15 e-rms AO Facility Review, 24. 08 16

GALACSI Performance specification NFM performance WFM performance 20 Years AO@ESO 17

Outlook to GRAAL Commissioning 20 Years AO@ESO 18