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Beyond 6dF (what more can we do for you?). Anna Moore Roger Haynes Will Saunders + BJB. ECHIDNA. Counterweight. Fibre Positioner for Subaru/FMOS Piezo ball-spine 400 fibres 0.5deg diam. 150mm Pick-and-place 0.9-1.8 m m Feed FMOS spectrograph. Steel Ball. Magnets. Spine.
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Beyond 6dF(what more can we do for you?) Anna Moore Roger Haynes Will Saunders + BJB
ECHIDNA Counterweight Fibre Positioner for Subaru/FMOS • Piezo ball-spine • 400 fibres • 0.5deg diam. • 150mm Pick-and-place • 0.9-1.8mm • Feed FMOS spectrograph Steel Ball Magnets Spine Echidna Ball-Spine
Moduleassembly Top bridge Fibre cover Middle bridge Fibre spines and piezo actuators Module PCB Module base
Echidna complete design Single module
30 30 20 20 10 10 Y (mm) 0 0 -10 -10 -20 -20 -30 -30 -30 -20 -10 0 10 20 30 X (mm) ECHIDNA Example of fibre allocation to randomly scattered targets 7mm spine deviation 90% success rate for random targets
Applications for Echinda Gemini wide-field MOS (GWiMOS) • 1.5deg2 at prime focus • Corrector design exists (400kg) • 0.5arcsec images (1” fibres) • 1.4m corrector • 4000 fibres • Echidna fibre positioner • Fibre-spacing compatible with Subaru • 10 more fibres, 10 larger area
Gemini wide-field • US$20M project • Initial design already begun (NOAO/AAO) • Opportunity to use AAO funds (A$2.5M) • Committed over 2002-05 as part of successful bid to Aus. Govt to increase Gemini share • Build prototype to address ‘high-risk’ areas • addressing >1000 fibres • patrolling field/reconfiguring times Build prototype for use on UK Schmidt
ECHIDNA Prototype Concept Positioner • 2250 spines (15 arcmin patrol area) • Slight lower packing than Echidna (s’graph limited) • 60mm diameter (4 arcsec) • <10% vignetting over full 6o f.o.v. • Spine Tip Imager: ‘single shot’ for full field • 5min reconfiguration time SCHM
Spectrograph Concept • Based on KOSMOS concept • Single-beam Schmidt-Schmidt spectrograph • Collimator f/2.25 • Camera f/1.3 • VPH grating: R=10000 • 2 x 2k x 4k CCD • 3 slits (750 fibres each) • 1st order 845-870nm (egrat=0.9) • 2nd order 422-435nm (egrat=0.8)
Schmechidna • Total cost A$4M • Spectrograph: A$1.5M • Positioner: A$2.5M • Purpose designed for stellar work • IAB=15.5 R=104 S/N=30 in 1200s (S/N for 2nd order) • 30 mins/field (inc. overheads) • 60% clear • 2000 objects/field (not limited by stellar density) 22000 objects per night (average)
Options Option A • No upgrade to existing system Option B • 6dF full upgrade: • new field plates + new spectrograph Option C • Schmechinda
Cost/benefit analysis DIVA survey (accessible from Australia): done in ~3yr *Fields/clear night: 5 (A), 8 (B), 18 (C) Ids/field: 100(A), 135(B), 2000(C) Fraction clear: 60% Resolution: 4000 (A,B) 10000(C)
Futher Issues • Schmechidna: medium technical risk • Echidna spine module already working • patrol camera innovative • AAO ‘in kind’ contribution: $2.5M • only $1.5M outstanding instrumentation costs • Room to increase S/N or mag. limit • 107 stars in 5 years (S/N 50 or Ilim 16)
Further issues • Survey using Schmechidna start in 2005/6? • Minimum of 107 stars by 2007 2010 • depending on survey parameters • N. hemisphere: Kisochidna/KOSMOS?? • Double cost • Double number of objects • Cover whole sky Schmechidna All New Stellar Survey for Orbits, Uelocities, and Chemical Indices