Download PPT - MagellanTech

Magellan F/5 System Status
A.Szentgyorgyi/SAO/25 Sept
2004
Overview
• Focus will be optically identical to MMT
- 1°, Curved spectroscopy focal plane
- 1/2°, Flat imaging focal plane
• Atmospheric dispersion compensation
• Wavefront sensing & guide function
• Shutter & filter handling
• “First light” instruments MMIRS and Megacam and
capability to serve wide field to MIKE fiber feed
Core Elements
• Wide field corrector & ADC very similar to MMT.
• Instrument adapter to provide interface from MMT
mounting to Clay rotator.
• Topbox for Megacam shutter & filter handling.
• Wavefront sensors included in instrument or topbox
functionality.
• F/5 Secondary supplied by Magellan.
• Software interface to Clay guiding and mirror support
software.
• Ancillary handling fixtures.
Wide Field Corrector Optical
Elements
Wide Field Corrector Optical
Elements
Optical Fabrication
• Fabrication by
Goodrich/Danbury
• L1 & L2 and ADCs
complete
• L3 & L4 complete on
30 Oct 04
AR Coatings
Are two viable suppliers of AR coatings for
refractive optics this large with two
complementary technologies:
• Sol Gel coatings by Cleveland Crystals –
fragile, but optically superb & trivial recovery
from bad coating.
• Dielectric multilayers by SAGEM –
somewhat more robust, but not quite as
good as Sol Gel & bad deposition is
catastrophic.
Selected Sol Gel for WFC
Optics AR Coating
• Cleveland Crystal now under contract.
• Coating commences 11/11/2004
•Three months to complete
Structural and Optical
Analyses
• S.Gunnels has finished analysis of
global deflections of mirror cell.
• F. Perez’s has performed a pull
test on the Baade rotator bearing.
• Henry Bergner calculates bearing
is about half as stiff as spec. sheet
indicates & finds that the Instrument
Adapter is robust.
• Hope to get pull test on Clay
rotator bearing in Mar. or Apr.
• Ordway’s measurement of
interfaces was completed 23 Aug
2004.
• Will produce detailed performance
prediction in next three weeks.
• WFC will be a tight fit.
• Have measured the diameters and roundness of critical diameters
and flatness of axial references in August 04.
• Rotation axis of Cass bearing apparently within ~0.001” of center of
WFC mounting surface, but ovalized ~0.003”
• Mounting holes for WFC are up to 0.035” from true position.
• Will fit check the WFC flange in Mar or Apr when tertiary comes out again
before lenses are bonded into cells.
• Will fit check Instrument Adapter if possible.
Lift Fixture
Tertiary Lifting Fixture
F/5 Lifting Fixture Concept
Software
• Need to develop interfaces between F/5
wavefront sensor & mirror support system and
the Megcam/MMIRS guide CCDS & telescope
• S. Schaller will accept raw Shack-Hartmann
. and guide images.
Electronics
• Magellan cable runs are ~3x as long as MMT,
so we are required to develop a new controller
architecture.
• We have minimized size of interface; each
subsystem only requires AC, optical fiber &
ethernet.
• Will need to deliver coolant to modules on
Cass rotator.
Project Status
• All WFC optic done except L3 & L4
- Completion 1 Nov 04
• WFC AR coating done early Feb 05
• ADC bearings complete
• Other WFC structures in work.
• WFC complete Oct 05
• Topbox in work
• Instrument Adapter fab. Starts next two
weeks.
• Lift table, handling fixtures fab starts Jan 05
Project Status
Expect on-schedule delivery in early
Jan 2006.