Magellan F/5 System Status

A.Szentgyorgyi/SAO/25 Sept 2004

• 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

Overview

• 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.

Core Elements

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

• 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.

Structural and Optical Analyses

• 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 FixtureF/5 Lifting Fixture Concept

• 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.

Software

• 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.

Electronics

• 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

Project Status

Expect on-schedule delivery in early Jan 2006.