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PHARO is the Palomar Workhorse AO Instrument. Commissioned in early 1998Built at Cornell: Tom Hayward/Bernhard BrandlJHK Imaging spectroscopy coronagraphyVery good opticsAll reflective: 2 plate scales25 mas (Nyquist @ 1.2 mm)40 mas (Nyquist @ 1.9 mm) 35 nm RMS WFE (Hayward et al 2001). Pr
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1. PHARO (2?) James Lloyd
(Cornell)
2. PHARO is the Palomar Workhorse AO Instrument Commissioned in early 1998
Built at Cornell: Tom Hayward/Bernhard Brandl
JHK Imaging + spectroscopy + coronagraphy
Very good optics
All reflective: 2 plate scales
25 mas (Nyquist @ 1.2 mm)
40 mas (Nyquist @ 1.9 mm)
35 nm RMS WFE (Hayward et al 2001)
3. Problems with PHARO Detector
Early generation HAWAII-1 (1k)
Very peculiar reset anomaly
Limited dynamic range
Reliability of acquisition system based on SPARC-2/SunOS platform
Mechanism Reliability due to cryogenic Phytron Motors
4. Aperture Masking
5. Closure Phase/SelfCal
6. Contrast vs l
7. L Band Masking @ Keck
8. L Band Masking @ Palomar
9. Upgrade PHARO? Teledyne (Rockwell) has been advertising the “H4-RG-10” as the next generation:
4k x 4k detector with 10 micron pixels
a 10 micron pixel would give PHARO Nyquist sampling at l=660 nm.
Current generation of HgCdTe detectors from Teledyne are available substrate removed with QE>70% to l=400 nm
10. Upgrade PHARO? This would be neat:
push out l to cover the visible for P3K and the L/M bands for a masking planet survey
Solve the detector problems with PHARO
Solve at the same time PHARO mechanical problems and implement additional desirable capabilities.
(nb there is a wrinkle that additional cooling requires a new dewar)
Cornell is considering an NSF/MRI proposal to fund this upgrade
11. Options 10 micron pixel detector
Teledyne has fabricated Si-pin H4RG-10, but there are problems with the unit cell
A H4RG-10/H2RG-10 is probably $0.8M-$1.0M development today.
H2RG-18 with 0.7-5.3 mm substrate removed detector: about $400k + a whole new instrument (at least another $1M)
H1RG-18 with 0.7-5.3 mm substrate removal. May be able to add the optics for a finer plate scale, but likely will be stuck with 25mas pixels.
12. Questions/Comments? Will there be a role for PHARO without an upgrade?
Are there other important considerations or suggestions for a PHARO upgrade?