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IRTF Adaptive Optics System Review Overview • IRTF is building a 36 element curvature based AO system • Purpose of this Review - Is to identify any remaining design, installation or operational problems and to expose the IRTF staff to the system details • Present Status – Design 90% complete, construction 70% Overview AO System Block Diagram AO Relay AO Wavefront Sensor(WFS) Target Science • Planetary Science Jupiter and it’s satellites (using the satellite to guide) Saturn and it’s satellites (using the satellite to guide) Neptune (using the disk to guide) Uranus (using the disk to guide) Mars (with to-be designed wide field WFS) • Mission support Cassini(Saturn), Galileo (Jupiter), Mars Global Surveyor, Mars 2001 Non-planetary Science projects •Searches for companions to nearby stars (BDs and planets) •Astrometry of companions for second epoch confirmation •AO Spectroscopy for spectral typing R~1,000 •Large telescope follow up for Radial Velocities R~10,000 •YSO disks and companions •Imaging of disks and companions •Companion spectroscopy •Imaging (JHKL) of young star clusters •high resolution imaging for luminosity and mass functions, disk lifetime studies •Seyfert galaxies •AO spectroscopy of nuclear regions •Quasar hosts •JHK imaging of underlying host galaxy Expected Image Quality Performance Filter Wavelength (microns) Lambda/D Expected Strehl J H 1.25 1.6 0.086 0.112 50% 60% K L M 2.2 3.8 4.6 0.151 0.259 0.315 70% 85% 95% Estimated Performance (continued) Estimated Emissivity Addition of 6 mirrors – 5 Silver(1%), one Aluminum(2.2%) Wavelength Telescope Emissivity Sky Emissivity Telescope+ Sky AO Emissivity Telescope+ Sky+AO L(3.77) 7% 2.5% 9.5% 7.2% 16.7% M(4.58) 7% 10% 17% 7.2% 24.2% Estimated Performance(continued) Sensitivity Limits •Full AO correction, average to good night, within 30 degrees of zenith is expected to 12-13th visual magnitude •Partial AO correction out to 15th magnitude with a gradual decrease in performance. •Tip/tilt only correction to 16th Top Level Requirements •A design that is optimized for planetary observations •Operation with NSFCAM(two plate scales) and SPEX •Optics that allow easily removing the AO optics from the beam •Support of differential track guide/science objects •A wavefront sensor field of view that allows tracking directly on Neptune and Uranus. •A wavefront sensor that bolts on the instrument and is fed via the science instrument cold dichroic •Operation optimized for J, H, K wavelengths with low enough emissivity to work at L and M. •Pass a corrected science field of 80x80 square Desirable Features • Easy changing between platescales on NSFCAM • WFS optics that allow IR wavefront sensors in the future. • Guide camera w/visible Photometry capability Optical Design IRTF AO Relay Optical Layout Optical Design Wavefront Sensor Optical Performance Relay performance ~96% Strehl over the 80 arcsecond field WFS performance ~95% on axis to ~80% in the corners at visible wavelengths Relay optics specified at Lambda/20 in the visible to reduce scatter to below the atmospheric scatter. AO Components • Dan AO SYSTEM NASA IRTF MECHANICAL SECTION Vern Stahlberger Mechanical Tasks: 1) RELAY 2) WAVE FRONT SENSOR 3) APD RACK MOUNT 4) SPOOL 5) AO AND SpeX (Interface) 6) AO AND NSFCAM (Interface) 1) RELAY I: DESIGN DRIVERSA) Tolerances: Position Optical Elements to 0.001 inch Tilt Tolerance: 0.016 degrees (~ 54’) B) Must be able to assemble Relay with MIM in place C) Kinematic Mounts for Optical Elements A) Tolerances: HOW TO ACCOMPLISH! General Rules: 1)Design for absolute positioning (no adjmts) 2) Minimize interfaces => (more complex prts) • Limit Structure Deflection: FEA done; shows < 0.0001 inch max. deflection • Positional accuracy: Precision machined optical Mounts with doweled interfaces to Relay.Detail drawings are built with tolerances to meet these requirements. Sub-sections of Relay precision machined and doweled. • Tilt tolerance of 0.016 degree (~ one minute) The tolerances on the optics mounts are well within these specifications. B) Ability to assembly above MIM ,Relay is 8ft+long OA RELAY SUB-SECTIONS C) Kinematic Mounts for Optical elements (Flat2) II: Construction: 1) Relay made up from 3 subsections; all bolted assemblies. 2) Made from Plates Alu Sup K100 (used for Stability and Flatness) 3) Weight: ~ 260 lbs 4) Overall Dimensions: 101 x 21 x 12 inches III: Relay Optical Subassemblies 1) Flat1&3Mount (6 “ translation, in-out of beam) 2) Flat2 Mount (Fixed) 3) Fiber Optics Guide (2” translation, in-out of beam) 4) OAP1 (Fixed) 5) DM (Fixed) 6) OAP2 (Fixed) Optical Elements supported by Relay Structure DM Flat2 OAP TO DEWAR OAP Flat1 Flat3 Relay Optical Subassemblies DM DM mount Fold2 Mount OAP Fold1&3Mount OAP Interfaces: doweled/bolted DM-Subsection of Relay Relay: Fold1&Fold3 Assembly Relay assembled except some optics mounts 2) WAVE FRONT SENSOR I: Design DriversGeneral Rules: Absolute positioning Minimize interfaces A) Positioning Tolerances for Optics: 0.001 inch B) Optics Bench: Flatness over surface <.0025 C) Assemble WFS to both NSFCAM and SpeX D) Kinematics Mounts for Optical Elements E) Light Tight Enclosure (1 bend) F) Cable Feed Through ( Fiber +) A) Positioning Tolerance:how to accomplish • Precision machined Optics Mounts: GD&T is used for specifying important dimensions and geometric relationships on individual detail drawings. • Each Optics Mount is individually doweled to the Optics Bench. Bench is toleranced to meet specs Example of kinematic mounting Assembly Drawing for Steering Mirror: Example of Kinematic Mount B) Optics Bench: (Features) • Rigidity: Primary concern (to prevent relative platform motion) • Guaranteed flatness by Vendor < 0.0025 inch • Lightweight Structure: 47 lbs • Max. Static Deflection 0.001 inch/40lbs load applied at center. • Dimensions: 44 1/2 x 15 x 2 inch Custom Optics Bench with Ray-trace Lenslette array Membrane Mirror Dichroic Newport Optics Bench Design: TRUSSED CORE DESIGN:Extra Steel Member through center of cell significantly stiffens cell with little increase in weight. C) Assemble to both NSFCAM and SpeX • WFS will bolt to Vacuum Jacket of either NSFCAM or SpeX • NSFCAM will have two focal positions: WFS will be shifted by 2.75 inches when changing plate scales. Note: Apd Mount will not move when changing Plate-scales on NSFCAM. Tie brackets are used to bolt Apd Mount and WFS together only when changing instruments D) Kinematic Mount for Optical Elements E) Light tight Enclosure:Access covers WFS Optical Subassemblies 3) APD MOUNT I: Design DriversA) Cool Apd’s + Thermal Managment B) Need Access to Apd’s for Service/Replacement C) Need Wire feedthroughs for Fiber and Coax’s A) Cool Apd’s Heat dissipation per Apd = 2.6 Watts For 36 Apd’s ~ 100 W Set: In calculator- (next slide..) Apd Steady State working Temp. = 25 degrees C Fluid Stream Velocity = 1 m/s Fluid Free Stream Temp. (Dome) = 5 degrees C Fluid (Air) density=1.252 kg/m^3 Calculated: Heat Transfer Rate to Air: Q with the purchased heat sinks For 2 large heat-sinks =171.6 W + for 2 small heat sinks =85.8 W Total Q=257.4 W (Q is proportional to Area of heat sink) Heat Sinks: Two sizes Heat Transfer Rate to Air: Large sink However…. Air Properties at Sea level Air Properties at 5000 m Density at 4000m Recalc.Heat Transfer Rate to Air: Fluid density at 50% from previous calculation 27% Reduction We can expect: Heat transfer Rate to Air Q: on Summit 2 * 62.3 + 2* 31.1 = 187 W B) Access to Apd’s (Service/Replacement) Basic Heat Exchanger Core with mounted APD’s Heat exchanger core with G-10 insulation Thermal Insulation from Rack; Use of Sil-pads under Apd’s Sil-Pads Sil-Pads were developed to eliminate the need for thermal grease. They consist on an elastomeric binder compounded with a thermally conductive filler coated on a carrier. A typical filler material used is alumina. On application, the Sil-Pads are meant to flow under pressure. C) Wire feedthrough for Fiber/Coax Cables Green part is neoprene, slits not shown (Coax shown) 4) SPOOL: STARTING CONCEPT SPOOL: NEEDS FEA 5) AO AND SPEX Modifications to SpeX: •Vacuum Jacket: no changes •Calibration Box: will need 3 tapped holes SpeX Vacuum Jacket and Cal-box with Ao Spex CalBox Tap 3 holes Vacuum Jacket WFS Apd Rack Mount 6) AO AND NSFCAM 1:1 PLATE-SCALE SHOWN Modifications to NSFCAM: • Design is shown for NSFCAM Upgrade: • Interface Box needs to be redone • Bottom of instrument needs an extension •Note: The AO System can be fitted to •NSFCAM as it exists presently. Holes •will need to be drilled into the VJ. NSFCAM: 1:1 PLATE-SCALE NSFCAM: 3:1 PLATE-SCALE THK Mechanism to Change Plate-scales Note: Telescope is at Zenith Rails bolt to NSFCAM Interface AO ON NSFCAM w/WFS +APD Mount AO AND NSFCAM: 3:1 PLATESCALE Shim for Adjustm. Procedure to change Plate Scales for NSFCAM: Notes: a) When using NSFCAM, the quick release ball lock pin should always be in place! b) The Apd Rack Mount will NOT move with the WFS box when changing plate scales, except possibly be moved out on the drawer slides for access. 1) Telescope is at Zenith 2) Loosen 8 Captive Screws (1/4-20) (sliding the Apd Rack mount out will make it easier to get at the bolts and pivot brackets) 3) Move the WFS box AWAY from the VJ of NSFCAM. 4) Rotate the pivot brackets in or out depending on Plate scale to use 5) Make sure the field adjusted spacers are in place 6) Bring WFS box in slowly, the tapered pins will help to guide it into proper position. 7) Tighten 8 Captive Screws (1/4-20) Status:Mechanical (% complete) • Relay: 90% (OAP Optics Mounts not done) • WFS: 90% (some detailing left,Fab started) • Apd Rack Mount: 100% complete • Ao to SpeX interface: 75% (detailing only) • Ao Spool: 10% (FEA required) • Ao to NSFCAM interface: 75% (detailing only) • Offset Guider/On-axis camera: not started • Handler on Telescope (10%) AO Electronics Peter Onaka Major Subsystems • Wavefront Sensor Assy = Deformable piezo mirror, optomechanical subsystems + lenselette fiber feed • APD Mount Assy = Fiber in/Counts out, EG&G Avalanche Photodiodes, cooled chassis • AO Crate = APD counters + mirror high voltage amplifiers • AOPC = AO calculation CPU (Real Time Linux PC) • Motion Control Box = opto-mechanisms in WFS • Vendor support electronics = tiptilt drive, X,Y,Z stage IRTF NETWORK TELESCOPE CONTROL ROOM AOPC PCPS TERMINAL SERVER ETHERNET AO CRATE MOTION CONTROL PCI-DIO-32HS NAT. INST. +12V RACK PS X Y Z STAGE -12V SH6868-D1 +5V AOPC TX MULTI-FUNCTION BOARD RX FIBER OPTIC 62.5 J1 10 METERS RX FIBER OPTIC 62.5 MEMBRANE MIRROR APERATURE CONTROL AO CRATE MULTI-FUNCTION BOARD/INTERFACE TX PICK OFFMIRROR TIP/TILT N D FILTER MASTER CLOCK +12V OUT OPTIMA IN AUDIO AMP 25W X2 FIBER CALIBRATION STAGE SINE WAVE PHASE CONTROL GATE GENERATOR BULKHEAD 24 CHNL COUNTER #1 BULKHEAD P2 P2 -C1 BNC X36 24 CHNL COUNTER #2 P2 P2 -C2 TO MECHANISMS 12 CH HV AMP #1 P2 SOLA-SDN 5-24-100 24V 5A 12 CH HV AMP #2 ULTRAVOLT + /- 500V PS #1/2 24-NP125W IN BNC X3 P2 P2 -HVA2 12 CH HV AMP #3 PI TIP/TILT AMP 19" RACK P2 -HVA1 P2 P2 -HVA3 OUT LEMO X3 S P HVA-DMCABLE 20 FT. PI-TIP/TILT CABLE 20 FT. S LEMO X3 W AVEFRONT FRONT SENSOR MEMBRANE APCONTROL MEMBRANE MIRROR LENSLET BNC X36 APD'S P ADAPTIVE OPTICS RELAY 66-PIN DM ND FILTER X,Y,Z STAGE 3MFIBER X36 AC/DC 5V 50A SUPPLY FIBER CALIBRATOR PICK-OFFMIRROR SCIENCE INSTRUMENT APD-COUNTER CABLE IRTF ADAPTIVE OPTICS BLOCK DIAGRAM Wavefront Sensor Assy Electronics • Membrane Mirror: speaker driver • Lenselette: 36 SC terminated fiber cables • • • XYZ stage: Ball Aerospace Filter Wheel: vendor supplied Inputs: Photons from telescope, filter wheel control signals, X/Y/Z stage control, membrane mirror drive Outputs: 36 fiber cables • WAVEFRONT FRONT SENSOR MEMBRANE APCONTROL MEMBRANE MIRROR LENSLET 3M FIBER X36 ND FILTER X ,Y ,Z S T A GE APD mount • • • • Cooled housing for 36 EG&G Avalanche Photo-Diode modules Inputs : 36 fiber cables from lenselette array, power for APDs and fans. Outputs: 36 APD outputs, temp sensors, thermal cutoff switches. Power Dissipation ~100W nominal BNC X36 APD'S AC/DC 5V 50A SUPPLY 3M FIBER X36 AO Crate • • • • 7U Eurocard Chassis (not a VME computer system) Control boards Power supplies Amplifier for membrane mirror AO CRATE +12V RACK PS -12V +5V J1 RX TX AO CRATE MULTI-FUNCTION BOARD/INTERFACE TIP/TILT +12V OUT OPTIMA IN AUDIO AMP 25W X2 MASTER CLOCK SINE WAVE PHASE CONTROL GATE GENERATOR 24 CHNL COUNTER #1 P2 P2 -C1 24 CHNL COUNTER #2 P2 P2 -C2 12 CH HV AMP #1 SOLA-SDN 5-24-100 24V 5A ULT RA VOLT + /- 500V P S #1/2 24-NP 125W 12 CH HV AMP #2 12 CH HV AMP #3 P2 P2 -HVA1 P2 P2 -HVA2 P2 P2 -HVA3 PI-TIP/TILT CABLE 20 FT. S P AO Crate Boards • “remote” Multifunction board – – – • 24 Channel Counter boards x 2 – – • Fiber interface Sinephase Generator = system clock Backplane bus interface Inputs: APD signals, backplane bus Outputs: backplane bus 12 Channel High Voltage Amps x 3 – – Inputs: backplane bus Outputs: HV drive to Deformable Mirror AO Crate I/O • • I/O Inputs – – – • 36 Coax cables from APDs Fiber from PC MFB AC power X 2 Outputs – – – HV output cable to DM 3 channels of analog drive to PI piezo amplifiers Output cable to membrane mirror AO Crate Power Supplies • Power supplies – – • +/- 500V Ultravolt High Voltage Power Supply. Sola +24V supply for Ultravolt Amplifier for membrane mirror – Basic audio car amp AOPC AOPC • Real Time Linux PC – • • Read in APD counts/phase National Instruments DIO fast parallel PCI interface board “local” Multifunction board PCPS PCI-DIO-32HS NAT. INST. SH6868-D1 AOPC TX MULTI-FUNCTION BOARD RX Motion Control Box Form factor TBD • Ball Aerospace control electronics • Filter Wheel control • Physik Instrumente Tiptilt piezo amplifiers (may be separate assy) • Other mechanisms MOTION CONTROL X Y Z STAGE MEMBRANE MIRROR APERATURE CONTROL PICK OFF MIRROR N D FILTER FIBER CALIBRATION STAGE BULKHEAD Software Tony Denault Don’t blame me I am new 1. Software Plan A Zyoptics will give us a copy of their AO software.. Compile & Run! • • • • Received a port of Hokupa’a from VXWorks/RTLinux (40 % completed). Just enough to sample sensor data & check timing. (Does not output to D.Mirror). All of the higher level function also commented out. Major issues not addressed: – LP_SHMEM – pointers problem. – Semaphore – resource locking/protections. • Zyoptics software was configured to their hardware setup – slightly difference from IRTF hardware. 2. Plan B – “Oh no….. what’s plan B?” Zyoptics software can be used as raw material for IRTF system. Implement similar structure in RTLinux. to Reverse engineer & import code from zyoptics system IRTF system. Implement additional IRTF requirements. 3. The Guider (Porky) Detailed Design to be done later. Currently we just have a rough outline of hardware requirements. On/offset Acquistion/Guide Camera System Guider Layout Schedule to Completion Changes Required for AO Installation • Relocation of Electronics • Replacement of On and Off-axis Guiders • Replacement of NSFCAM’s mount Changes Desired for AO Installation • Control of Dome Thermal Environment • Removal of Electronics Heat • Control of Astigmatism with the Mirror Bender The End