LO WFS Summit 6/19/2015Richard Dekany A Joint Meeting of the NGAO, IRIS, and K1 LO WFS Teams 12/15/2009

Agenda 8.30am-8.45am WFS requirement comparisons RGD (15 mins) 8.45am-9.45am NGAO WFS (Kent/Alex) + discussion 9.45am-10.45am TMT IRIS OIWFS + discussion (David L.) 10.45am am Break 11.15am-12.15pm Keck IR TT + discussion (Roger) 12.15pm-12.45pm Detector update + discussion (Roger) 12.45pm-1pm Summing up

3 LO WFS Requirements Comparison 6/19/2015Richard Dekany 2009 LO WFS Summit 12/15/2009

AO system comparisons (All # TBC during meeting) Keck 1NGAONFIRAOS LGS asterismSingle, on-axis Fixed 3+1 tetrad on 10” radius and Patrolling 3 within 60” radius Fixed 5+1 on 30” radius Laser power30 W of LMCT format 4 x 12.5 W SOR format and 3 x 8.6 W SOR format 6 x 25 W SOR format First Light Science Instrument(s)OSIRIS, NIR IFS and imagerNGAO NIR IFS and imager IRIS, NIR IFS and imager IRMS, NIR MOS TT NGS sharpening strategySCAOMOAOMCAO First light (if funded) for IR TT>= 2015>= 2018

LO WFS Input Plate Scales Keck 1 arcsec = mm1 mm = 1.38 arcsec 1 mas =  m1  m = 1.38 mas TMT 1 arcsec = 2.18 mm1 mm = 4.29 arcsec 1 mas = 2.18  m1  m = 4.29 mas

Driving Requirements Keck 1NGAOIRIS Volume constraintTight; complex …containable w/in… 2m diameter and 750 mm height [REQ-3-IRISOIWFS-0010] (BFD is actually 780 mm) Pixel IFoV~12 mas …pixel IFoV shall be mas [REQ-3-IRISOIWFS-0220] Detector readout (per chip) Redefinable multiple RoI; Full-field ACQ mode Redefinable single RoI; Full-field ACQ mode Rapidly redefinable single RoI; Full-field ACQ mode ADCNo requirement Each WFS subass’ly shall include a separate ADC [REQ-3-IRISOIWFS-0170] Power dissipationNo requirement …< 2 W into NFIRAOS chamber… (0.5 W goal) [REQ-3-IRISOIWFS-0090] Patrol range per OSM channel None Ø120” = 87 mm [FR-159] …enough to meet NFIRAOS sky coverage… [REQ-3-IRISOIWFS-0280] OSM motion accuracy/precision None TBD [FR-177] (typ. 2  m precision?) …absolute accuracy…< 2 mas RMS anywhere in…patrol range…[e.g. < 4.6  m] [REQ-3-IRISOIWFS-0610] Science FoV (to not obscure) No requirement (restricted J-H FoR) ø15 mm = 20” ø29 mm = 40” (goal) [FR-41] Ø58 mm = 25” [REQ-3-IRISOIWFS-0240] (changing as of 12/15/09)

OIWFS comparisons Keck 1NGAOIRIS Number / Type of NGS WFS 1 TT (TTF goal)2 TT + 1 TTFA (dedicated)3 TT / TTFA (selectable) Object Selection Mechanism NoneTheta-phi probe armsR-theta probe arms Active mirrorsNone32 x 32 MEMS DM None (accessible pupil) LO WFS gravity environment Fixed at Nasmyth OSM patrols vertical plane at Nasmyth Patrols horizontal plane at Nasmyth; rotates LO WFS acquisitionFull FoR imaging Ø 5 arcsec OSM FoV w/ aux. visible ACQ camera available Ø 4.4 arcsec OSM FoV w/ aux. IR ACQ camera available Spectral band K (full FoR) or J through H (> 35” off-axis) J through H

8 LO WFS Summit Wrap-Up 6/19/2015Richard Dekany 2009 LO WFS Summit 12/15/2009

Areas of potential common interest Detectors – HxRG characterization Other interests: HgCdTe e-APD (256 x 320, ~60-80% QE coming)? – Linux controller implementation – Pixel sampling ( /2D; arguments for J vs. H ?) Filters / Coatings – J through H vs. J + H (w/ possible K-blocking) ADC designs? Dewar thermal designs / cooling systems (Smith / Vasisht) Small OSM focus motions? – Collimator squiggle stage vs. sensor plunger stage Dithering strategies? – NGAO needs to tackle this in next couple months Time studies for acquisition timeline (Bouchez) – Requirement of 120 seconds each (after slew) Component cost estimates? Calibration units – Positional accuracy of probe arms (e.g. I&T position calibration using aux. equipment) – AO relay distortions (e.g. using a fiducial pinhold grid mask for IRIS)