ESO Technology Needs Ireland Industry Day Marco Quattri Engineering, ESO
Dublin 17.09.2018 Overview
Complete Observatory From concrete to plumbing Mechanics: structural, vibrations, seismic Environmental engineering: wind, micro- seismic General Telescope Technologies ➢ Active Optics ➢ Adaptive Optics ➢ Tracking and guiding ➢ Interferometry
Instrument Technologies
(Sub)millimeter technologies: ALMA
ELT Technologies
Dublin 17.09.2018 Key-Technologies in Astronomy
ESO has contributed to the progress of several technologies in modern astronomy to improve the image sharpness, among these: ➢ ACTIVE OPTICS • Preserves optimal image quality by adjusting a “flexible” mirror’s shape with actuators during observations (i.e. corrects telescope flexure) • In use in most modern medium and large telescopes ➢ ADAPTIVE OPTICS • Technology to reduce distortions introduced by atmospheric turbulence • One of the principal reasons for launching the Hubble Space Telescope was to avoid this image smearing ➢ INTERFEROMETRY • The combination of the light collected by two or more telescopes boosts the angular resolution beyond that of a single telescope • ESO has been a pioneer in this field with the Very Large Telescope Interferometer (VLTI) at Paranal
Dublin 17.09.2018 Principle of Active Optics
Closed control loop with:
1.Measurement of wave front error generated by the telescope itself ➢ Integration times of ~30 sec ➢ Modal analysis using optical aberrations and elastic modes of the flexible meniscus mirrors
2.Correction of the errors by the optical elements of the telescope ➢ Rigid-body movements of the mirrors ➢ Deformation of the mirrors by adjusting the support forces
Dublin 17.09.2018 Active Optics From the NTT to the VLT A computer-controlled active optics system was first developed by ESO in the 1980s The first major telescope to benefit from this revolution in telescopic techniques was ESO's New Technology Telescope (NTT) at the La Silla Observatory This has become a standard technology for all major new telescopes
VLT Mirror
VLT Cell
Dublin 17.09.2018 Adaptive Optics
An adaptive optics system (AO) corrects turbulence in the atmosphere (loop frequency in kHz range), which is much faster than corrigible by the active optics ➢Active optics: Shape of the primary mirror adjusted by stiff actuators to compensate slowly changing disturbances (gravity flexures, thermal deformations) on a timescale of tens of seconds ➢Adaptive optics: Shape of a smaller and thinner deformable Turbulence in the earth atmosphere: mirror adjusted (typically second Cassegrain Warm (red) and cool (blue) air cells (~10 mirror “M2” or a subsequent mirror cm) distort the incoming wavefront from conjugate to pupil plane) the star.
Dublin 17.09.2018 Adaptive Optics Principle
Dublin 17.09.2018 An AO Milestone: MAD
MCAO: 3 Guide stars at 2’, K-band, FWHM: 100- Multi-conjugate adaptive optics demonstrator 120mas, Sr: >20%, 0.7” seeing, Exposure 360 s (MAD) installed on Nasmyth A of UT3
Dublin 17.09.2018 Laser for Adaptive Optics
LASER GUIDE STARS LASER DEVELOPMENT ➢ Laser guide stars are artificial stars ➢ In 2009 ESO demonstrated continuous generated by excited atomic sodium in the output power >50 W at 589nm in a narrow mesosphere at an altitude of 90km spectral line ➢ This requires a powerful laser beam ➢ Optical fibre Raman amplifier technology launched from the telescope. The yellow developed at ESO and licensed to industry wavelength (589nm) is the colour of a sodium street lamp ➢ Milestone industrial demonstrator of 20W using technology developed by ESO
Dublin 17.09.2018 Laser Guide Star Development
4LGSF Laser Launch Telescope
4LGSF Laser Guide Star Unit
4LGSF LGSU1 Installation Tests
Field Selector Beam Steering Mirror
Dublin 17.09.2018 10 4LGSF Commissioning
Dublin 17.09.2018 11 Adaptive Optics Facility
Adaptive Optics Facility (AOF): Technical Data of 4LGSF: ➢ Second generation AO System on UT4 ➢ 4 LGS, off axis up to 330” ➢ Uses 4 laser guide stars, a deformable ➢ 2.5-5 Mphot/sec/m2 secondary mirror (DSM), and 2 WFS modules: ▪ GALACSI for instrument MUSE ➢ LGS FWHM <1.2“ on WFS ▪ GRAAL for instrument Hawk-I ➢ 4 LGSs fixed on pupil ➢ Commissioning 2016/2017 The 1.1 m DSM used for AOF The GRAAL WFS-AO module The 4 LGSF in final constellation
DSM AIV in NIH
Dublin 17.09.2018 12 Deformable Secondary Mirror
Reference Body Wave front map : < 10 nm RMS
2.6m glass shell, 2 mm thick at SAGEM (experimental for ELT)
➢ Reference Body manufactured by SESO (France) ➢ Thin Shells manufactured by REOSC (France) ➢ Complete new M2 Unit designed, manufactured, tested and delivered on-site by Microgate and ADS DSM installation on UT4 (Italy)
Dublin 17.09.2018 13 Detector Development
Near infrared high speed wavefront sensor: eAPD array ▪ HgCdTe Electron Avalanche PhotoDiode array: 320x256 pixel ▪ Avalanche effect offers noiseless amplification sensitivity larger by factor 100 ▪ first time worldwide NIR subelectron readout noise at 5Mpix/s/output ▪ Technology only available in Europe: SELEX (UK), SOFRADIR (FR) funded by ESO & NSF ▪ Needed for IR wavefront sensing and fringe tracking in interferometry (GRAVITY)
Mid infrared detector (3-28 mm): AQUARIUS ▪ Arsenic doped Silicon detector (Raytheon) ▪ 1024 x 1024 pixels, 30 µm pixel-pitch ▪ Hybridized construction: silicon MUX + indium bumps ▪ 64 outputs with 150 Hz frame rate
Dublin 17.09.2018 14 NGC: Generic Control Electronics
• Controller platform NGC is the result of three decades of development at ESO • NGC is a state-of-the art controller for all detectors at the observatory • high speed (10MHz) low noise (sub-electron) AO wavefront sensors • large format mosaic (VISTA: 256 channels)
Dublin 17.09.2018 15 Real Time Computer & Control Future E-ELT needs Complexity vs time SPARTA dev @10ESO13 today EPICS
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7 NAOS ATLAS 10 RTC for MACAO MAORY in 2002 EAGLE MACAO EPICS 6 10 2000 2005 2010 2015 2020 2025 Dublin 17.09.2018 16 VLT – Main-Axes Drive System
VLT is well known for its excellent tracking performance. The four main contributors to this technology are:
1. Direct drive motors 2. Collocated encoders 3. Hydrostatic bearing system 4. Innovative control algorithms
Dublin 17.09.2018 17 VLT – Technologies
▪ VLT was the first telescope to use large diameter direct drive motors (early 90s) outperform traditional gear or friction coupled drives due to high stiffness and no backlash little wear and maintenance 10 m ▪ Direct drive motors offer possibility of using collocated encoders optimal for control engineering VLT encoders are high quality tape encoders with same diameter as the motors. mounted together on the same structure, accuracy ~0.1” ▪ VLT main axis uses hydrostatic bearing system telescope structure floats on an oil film of thickness 50 µm. very low friction (one person can move it) absence of stick-slip friction make the system practically linear. huge advantage for the control system ▪ First telescope with entire control system implemented in software Dublin 17.09.2018 18 VLTI = VLT & Interferometry
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Dublin 17.09.2018 VLTI Scheme
Very Large Telescope Interferometer (VLTI) ➢ Combines light from the 8-m UTs and several moveable 1.8-m ATs, separated by up to 200 m ➢ Inside a130-m long underground tunnel the light beams pass through delay lines to balance the optical path length from each telescope ➢ The resulting interference fringes provide information needed to reconstruct an image with unprecedented detail ➢ The angular resolution is increased according to telescope distance, i.e. 10-20 times better than individual telescope opens door to milli-arcsec resolutions
Dublin 17.09.2018 20 Instrument Example MATISSE ➢ Instrument MATISSE: ➢ Multi AperTure mid-Infrared SpectroScopic Experiment; ➢ Project lead: Observatoire de la Cote d'Azur and University of Sophia-Antipolis, Nice ➢ Operating with 8-m telescopes (UT) and 1.8-m telescopes (AT) ➢ Combine four telescopes in 2 mid-infrared, channels LM and N-band; interferometric instruments ➢ Spectral resolutions between R=30 and 5000 ➢ Complex Optics: ➢ Warm part includes delay lines, anamorphic optics, periscopes, dichroics and calibration sources ➢ Two cryostats contain cold optical benches including spatial, polarimetric and chromatic filters, beam splitters, prisms, grisms, polarising optics, focussing optics Dublin 17.09.2018 21 Instrument Technology Developments
MUSE Instrument: ➢ Built by Consortium under the lead of
Dublin 17.09.2018 Center of Astrophy2s2ical Research in Lyon (CRAL) Cryogenic Systems & Lines Cooling systems and cryostats down to 3 Kelvin, small and large scale
VLT MUSE cooling system with 24 identical CCD cryostats (built by ESO) small series production Single detector head cryostat for MUSE
Manufacturing and testing qualification of transfer and Wave front sensor cryostat for GRAVITY distribution lines for liquid nitrogen Dublin 17.09.2018 23 Manufacturing Small and Large structures
Small accurate parts
➢ Filter wheels, grating wheels, calibration slides optical mounts, custom gears, worm systems,
➢ Materials: Aluminum, martensitic and austenitic stainless steels, copper…
Large parts and structures ➢ Manufacturing Techniques for Aluminum structures ➢ Aluminum forming, TIG welding ➢ Machining, in-situ metrology for accurate reference ➢ Thermal treatments (cryogenic applications) ➢ Stainless steel structures ➢ Vacuum vessels, Cryostats Dublin 17.09.2018 Control Systems on PLC-basis
Cryogenic and Vacuum Control System for Scientific Instruments: X-Shooter, Gravity, MUSE, MATISSE
• Interlock and Safety Systems for telescopes and instruments ELT, VLT, 4LGSF • UT Dome control system upgrade • From the shelves components standardized SIEMENS, WAGOO, MAXON, PI, etc
Dublin 17.09.2018 Obsolescence management
➢HW Virtualization: keep HW and SW interfaces untouched • Today Design and back engineering made by ESO • Shall be outsourced FPGA and schematic design, Layouting, production, tests
Dublin 17.09.2018 26 Control Software at ESO
➢ At ESO, we develop control software for telescopes, antennae and astronomical instruments over the full lifecycle ➢ VLT Software: All current ESO telescopes and their instruments are based on the VLT Common Software and on the VLT Instrumentation Software
Graphical user interfaces Real time HW control VLT Software
Dublin 17.09.2018 27 Laser Frequency Comb (LFC)
Precise Wavelength LFC at 3.6m Telescope at La Calibration Silla High res spectroscopy Precision wl generation
Collaboration ESO – MPQ ➢ Spin off Menlo Systems Challenges: ➢ Coverage to blue (<400nm)
Dublin 17.09.2018 28 Detector Arrays For VLT (and ELT) instruments Near infrared Optical
➢ HAWK-I near infrared mosaic: ➢ OmegaCAM CCD mosaic ➢ 4 x Hawaii 2RG arrays (2Kx2K, HgCdeTe) - 32 CCDs, 268 M Pixels ➢ Cutoff wavelength λc = 2.5 μm ➢ 128 parallel video outputs ➢ NEW: 9Kx9K e2v CCDs for ESPRESSO ➢ cryogenic preamplifiers Also to be used in ELT instruments ➢ MICADO (ELT Instrument): ➢ mosaic of 16x4Kx4K Hawaii-4RG-15 arrays
Dublin 17.09.2018 29 New paradigms in optical design
➢ Curved detectors: ➢ potential for massive simplification of the optical design of instrument (i.e. high cost savings impact) ➢ Collaboration initiated with Laboratoire d’Astrophysique de Marseille (LAM). ➢ The goal is to demonstrate typ. R=200mm, >60x60mm2.
LAM/LETI results: Tunable Original design New design with curved detector convex/concave R=inf.to 270mm, 3kX5k from CMOSIS
➢ Free Form Optics ➢ Use a more complicated (freeform) shape rather than spherical lenses high flexibility ➢ Enabled by new manufacturing techcnologies Dublin 17.09.2018 ALMA Technology Developments
Selected Technology Developments
Dublin 17.09.2018 31 The ALMA Observatory
ALMA=Atacama Large Millimeter / sub-millimeter Array: ➢ Giant array of 66 radio antennas at 5000m altitude ➢ 54 x 12-m antennas which can be configured to achieve baselines up to 16 km for highest angular resolution, plus a compact array of 12 x 7-m antennas ALMA is a joint project between ESO, North America (USA, Canada), and East Asia (Japan, Taiwan, Korea)
Some challenges: ➢ Continuous operation at the Array Operations Site (AOS) at 5000m ➢ Operation up to 18 m/s wind ➢ Temperature extremes of -20C to +20C and large temporal gradients ➢ Seismically active region
Dublin 17.09.2018 32 ALMA Technologies
ALMA uses state-of-the-art technologies in many areas including ➢ Antennas ➢ Antenna transporters ➢ Cryogenic receivers (30-1000 GHz) ➢ Digital electronics & transmission ➢ Digital supercomputer ➢ Photonics ➢ Software
Dublin 17.09.2018 33 ALMA Antennas
➢ Demanding specifications, Industrial contractors: AEM • Thales-Alenia Space, leading to • European Industrial Engineering ➢ Direct drive system • MT Mechatronics ➢ Advanced metrology ➢ New materials (CFRP)
➢ Receiver cabin in CFRP technology: Low inertia, no need for insulation ➢ Antenna back structure out of 16 CFRP slices glued together ➢ High-res tilt-meter (sub-arcsec) to correct pointing errors due to wind- induced structural deformations.
Dublin 17.09.2018 34 Cryogenic Receivers
Specialized heterodyne receivers, operated at 2.5 K Superconducting detector elements Each antennas has one cryostat with 10 bands
Dublin 17.09.2018 35 ALMA Correlator
Specialized Supercomputer Operates at 5000m (Cosmic Rays tolerant) Key Technologies: high speed digital electronics CMOS ASICs (212 units), FPGAs ~1016 multiply/accumulate fixed point operations/s 32 full size cabinets, ~3000 printed circuit boards, ~5000 cables, ~20 million solder joints, 170 kW
Dublin 17.09.2018 36 Industrial Opportunities
➢Contributions to new developments ➢Radio astronomy instrumentation ➢Scientific software ➢Digital electronics ➢Machining of parts ➢Maintenance of high-tech systems in Chile ➢Mechanical (incl. CFRP repairs) ➢Electronic ➢Direct drive ➢Sensor equipment ➢Radio frequency equipment
Dublin 17.09.2018 37 E-ELT Technology Developments
Dublin 17.09.2018 38 FEA and CFD Analyses
M1 Segment subunit detailed FE model E-ELT Dome wind velocity distribution
Wind Tunnel Tests for Dome and Main Structure Verification of seismic •Validation of in-house CFD analyses isolation analyses by testing Seismic isolation 3rd mode shape •Input to specification requirements Dublin 17.09.2018 39 E-ELT mirror handling handling & treating large mirrors
2. 1. 3. 1. E-ELT segment handling system for M1 2. E-ELT large mirror handling system for M2, M3: gantry with 5 DoF, precision movement, force control 3. Mirror cleaning and washing facilities 4. Coating tank with infrastructure for applying y multi-layer coatings on glass-ceramic substrates (ca 4. 4m diameter) Dublin 17.09.2018 40 Control System Design
VLT - Model-based controller design based on frequency models
ALMA - Model-based non-linear damping system design
EELT - Prototyping and design of M1 and M5 control systems
Presentation of EELT technical concepts to the public
Dublin 17.09.2018 41 Optical Metrology Technologies
Monitoring telescope’s inter-mirror positions • Laser trackers (5µm/m): M1 • Multiline freq. scanning laser interferometry (0.5µm/m) M5
PA CT
Optical “hexapod” test on the VLT Flexure measurements using LT on the VLT Segment phasing during day time • Instantaneous Multiwavelength shearing interferometry (10nm, 1 arcsec sensitivity): • Multiwavelength fiber interferometry (nm resolution over 1.2mm)
Dublin 17.09.2018 42 Optical Phasing
➢Phasing test bench ➢ 61 elements segmented mirror, 4 sky phasing sensors, AO (SH 16x16, DM-227) ➢ Tested on sky: 10nm rms residual phasing errors on bright stars ➢ Study of cross performance with AO, incl. double segmentation and ability to perform efficient phasing using laser guide stars (spot elongation)
Internal Mach- Metrology Zehnder Curvature Turbulence Shack- generator ASM Pyramid Hartmann
Parabola
Dublin 17.09.2018 43 Prefocal Station Technologies
SensorArm
Cable wrap system and adapter PFS lateral mode Telescope Wavefront Sensor module (TWFS) module with sensor arms
Prefocal Station (PFS): Interface between telescope and instruments, • light can be directed to 3 different locations on and 1 below Nasmyth platform • Contains sensor arms with wavefront sensors and cameras active optics correction and telescopecontrol
Dublin 17.09.2018 44 Prefocal Station (PFS) Technologies
VLT Sensor Arm ELT Sensor Arm (System @ UT4) (Draft Design)
Pick-up mirror from CESIC
PMMA create unfinished aluminium castings Final milling Installation at Nasmyth Adapter mould
Dublin 17.09.2018 45 ELT Technologies for Adaptive Optics WFS cameras Low noise, fast, integrated cooling
Fast low-noise Deformable mirrors detectors High order >1k compact DMs Laser Guide stars E-ELT post-focal AO systems, Multi-Object AO Optimize and understand return flux and XAO Effect of elongated laser spots Strategy for direct tilt measurement (without natural guide star)
Real time computer Close to industrial standards Emphasis on obsolescence management
Dublin 17.09.2018 ELT M4: a deformable mirror on voice coil technology (Adoptica)
➢ 5152 actuators (4230 in on-axis pupil) ➢ 6 segment shells ~2mm thick ➢ Light-weighted structural reference body ➢ A “mirror cell” with load spreaders ➢ Hexapod for tip-tilt and decentering ➢ A rotator for Nasmyth selection ➢ Maintained to temperature using gas cooling
Thin zerodur mirrors (REOSC) Silicon Carbide reference petal Actuator Brick (Boostec) Adoptica
Dublin 17.09.2018 47 Deformable mirror technology development
Two technologies developed for extreme adaptive optics and multi- objects adaptive optics ➢ Push forward the voice coil technology on small pitch to reach high density of actuators (ALPAO- FR) ALPAO design: 1.5 mm pitch actuators Coil and magnet from clock industry Mirror in silicon membrane
1 DM developed already sold in Europe and 1 US institute interested to buyone
➢ Develop a new technology based on standard piezo actuators (PICMA technology manufactured by PI company -DE)
IOF-PI design: 3.7 mm actuator pitch Actuators mounted in modules Thin mirror glass shell
Dublin 17.09.2018 48 Technology needs in Astronomy Questions?
Dublin 17.09.2018 49 General Technology Needs
Optics, Opto-mechanics Detectors (Infrared, Visible) Mechanical structures Integration support and facilities Cooling and chiller system Heating, Ventilation, and Air conditioning (HVAC) Cranes and handling equipments Mirror coating facilities Actuators & Controllers Software Power generation and distribution systems Waste and chemicals treatment Laser systems at specific wavelength Consultancy (RAMS, PA, QA) And many more …….
Dublin 17.09.2018 50 Instrument examples: ERIS
➢ ERIS (Enhanced Resolution Imager & Spectrograph) ➢ Workhorse instrument merging the capabilities of two existing facility at the VLT. ➢ Uses Adaptive Optics paired with AOF @UT4
High precision optics and optomechanics
Laser driven light sources (courtesy Energetiq)
Dublin 17.09.2018 51