canada-france-hawaii-telescope interview and presentationbauman/publications/presentations/overview...

Canada-France-Hawaii-Telescope Interview and Presentation

Steven Bauman Principal Mechanical Engineer University of Arizona Steward Observatory 6-6-08

LOTIS 6.5m Primary Mirror Coating Effort

• Need 6.5m Aluminization chamber capable of coating the LOTIS primary mirror in it’s primary cell by March of 2008 • LOTIS has reached an agreement with the Multi-Mirror Telescope (MMT) to supply the back half of the coating chamber consisting of the Rear Bell Jar which include the Filament array, pumps, valves, and power supplies needed to pump down the chamber and coat the LOTIS primary mirror. •Started the process with a concept design with analysis to support and verify the design of components and the overall chamber assembly. Created drawings, researched vendors, reviewed proposals, and awarded a bid to the selected vendor for $500K. Acted as the main contact thought the manufacturing process. Managed and organized the set-up of the chamber for testing and coating. Performed actions needed during the coating and set-up process such as a witness sample verification method, a mirror cleaning procedure, and the lifting and staging of large assemblies and components.

6.5m Coating Chamber Concept

Closed Chamber Section view

Chamber GSE - Tilt Stand

Tilt stand rotation support

Tilt Stand Analysis

•Additional analysis examples:

•Primary Mirror Support stands. •P-Cell upright beam analysis. •Pickle fork analysis.

Tilt Stand drawing

Chamber GSE - Cart

Chamber GSE - Delivered

Chamber GSE - Cradle

Chamber Extension

Stand GSE

Stand drawing

Rear Bell Jar Arm

Rear Bell Jar Fabrication

Rear Bell Jar Fabrication Dwg.

Rear Bell Jar Finished

GSE and Tilt Stand Delivery

Rear Bell Jar Delivery

Rear Bell Jar Lift and staging

Rear Bell Jar on Tilt Stand

Chamber assembled and ready for Testing

Aluminum Filament Array

Coating Filaments

Witness Sample Specimens • 1” x 3” Glass microscope slides

– 45 samples placed on mimicked mirror contour. – Samples measured for coating thickness

• 1” x 3” Glass microscope slides – 25 samples placed on mimicked mirror contour. – Samples places in chamber for various testing

• 18” x 18” x ¼ “Borofloat Glass plates – 8 samples placed in chamber for various testing.

• 12” x 12” x ¼” Borofloat Glass plates with Simulated Hartmann mirrors bonded (4” x 0.75” Pyrex disks). – 4 samples placed in the chamber for on going Hartman testing.

• Specimens were coated in 6.5m test shoot #2. – Improved cleaning procedures

• A Final cleaning step involving a D.I. Water and Alcohol wipe just prior to installation in the chamber.

• A last cleaning step with CO2 snow treatment just before closing the chamber for pump down.

Coating Sample Layout

Specimens loaded in the chamber

Chamber opened to remove Samples

Chamber post coating

1” x 3” slides and other plates removed for testing

Step thickness measurements

• Optical thickness measurement devices. – Veeco NT-9800 - Optical Profiler – Micromap Topometer – Optical topographic reader

• Optical application – Dae Wook Kim – Optical graduate student – OSC

• All 45 slides measured by S.Bauman and Dan by 9-18-07 – Michael Jacobson – Optical data Associates

• 5 Slides measured to verify above measurements.

LOTIS 2nd Witness Sample Aluminum Coating

05

101520253035404550556065707580859095

100105110115120125

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135

Radius from center (in)

Coa

ting

thic

knes

s (n

m)

West East Vertical

Coating Thickness Summary

• Second Test Shoot Coating - Successful – Uniform thickness overall, average overall thickness 108

nm or 1081 angstroms. • Significantly better cleaning preparation for second shoot

compared the first shoot. • Final cleaning step with D.I. water and Alcohol reduced

cloudy, white, streaky, residue. • CO2 snow cleaning treatment reduced particulates from the

coating surface for better adhesion. • Primary Mirror cleaning procedure is being modified to

incorporate new final cleaning steps. • Hartman mirror protection plan on-going.

Rear Bell Jar moved Inside Lab

After the filament firing had been calibrated by the witness sample testing and measurements the coating chamber was disassembled and brought inside the integration lab for reassembly and the Final coating step.

Rear Bell Jar Rigging

Wrote lifting procedures and supplied detailed drawings for lifting, staging, and rigging equipment.

Tilt stand rigging

Tilt stand moved inside

Extension and Cradle Lift

Front Bell Jar Moved Inside

Final Component needed for Chamber Assembly

Chamber staging needed for assembly in tight quarters

Aluminization Chamber Assembled

•Chamber assembled inside Integration lab and ready for pump down and leak test. •Next task is to prepare the mirror for coating. •Clean Primary Mirror, tilt down to accept the primary mirror/Cell and coat.

Preparing the Primary Mirror

•The Primary Mirror needed to be shrouded in a way that was never done before horizon pointing. •A misting system was added above the mirror to keep the entire mirror surface wet during the cleaning process. •A plug was installed in the center of the mirror to keep out all liquids.

Mirror cleaning equipment •Multiple scissor lifts and an articulating boom lift were used to reach the entire mirror surface for the cleaning event. •Trained and Certified to operate forklifts, scissor lifts and articulating boom lifts.

Unique Cleaning Method •A special cleaning procedure needed to be developed to address cleaning a mirror horizon pointing as well as dealing with Hartman mirrors. •Developed a cleaning procedure and chemical list with process and guidelines.

Cleaning the Primary Mirror •Prepared a detailed schedule and checklist for cleaning the mirror.

•Organized and Managed a six (6) man team to carry out the cleaning activates.

•Worked with the team thought the process.

Drying the Primary Mirror •After the Primary Mirror was inspected and deemed clean and dry technique needed to be developed. •Ultra pure dry nitrogen, custom blow guns, and ESD guns were used to remove the water and dust particles.

•Chamber opened. •Coated 6.5m Mirror ready for inspection. •Rotate Rear Bell Jar down and remove the primary mirror and cell. •Coat the mirror with Opti-coat and tarp. •Disassemble the coating chamber and ship components.

Thank You CFHT

Any Questions?

canada-france-hawaii-telescope interview and presentationbauman/publications/presentations/overview...

Documents