1. LBT Q3 2008 Eng/SW Review ALPC – Primary Mirror Aluminum Shooting

2. 20-Oct-2008LBT Q3 2008 Engineering Review Highlights (Q3/2008) The third aluminization of the LBT SX primary mirror went according to schedule during the week of 11-August-2008. The third aluminization of the LBT SX primary mirror went according to schedule during the week of 11-August-2008. There were no significant problems, and the coating looks good There were no significant problems, and the coating looks good We are disappointed that the coating is still not well adhered to the glass substrate, but this does not impact science performance. We are disappointed that the coating is still not well adhered to the glass substrate, but this does not impact science performance. Old coating (SX2) had good adhesion over 70% of the surface Old coating (SX2) had good adhesion over 70% of the surface Only outer 70 cm of mirror had poor adhesion – sharp transition Only outer 70 cm of mirror had poor adhesion – sharp transition Ultraviolet reflectivity is still to be measured on the witness slides. Ultraviolet reflectivity is still to be measured on the witness slides. We continue to refine and improve the 8.4m coating procedures as we gain experience with the process. We continue to refine and improve the 8.4m coating procedures as we gain experience with the process.

3. 20-Oct-2008LBT Q3 2008 Engineering Review Progress (Q3/2008) Planning From Q3 Review Planning From Q3 Review Next Aluminization starts 11 Aug on SX √ Next Aluminization starts 11 Aug on SX √ Monday 11th: Mirror Wet with Chemicals 11AM-3PM Monday 11th: Mirror Wet with Chemicals 11AM-3PM Tuesday 12th: Final Wipe of SX Mirror Surface at Zenith, Tip telescope to Horizon Tuesday 12th: Final Wipe of SX Mirror Surface at Zenith, Tip telescope to Horizon Wednesday 13th: Mount Bell Jar & Start Pumpdown Wednesday 13th: Mount Bell Jar & Start Pumpdown Shoot aluminum Thursday night or Friday morning depending on weather and other issues. Shoot aluminum Thursday night or Friday morning depending on weather and other issues. Warmup on Saturday Warmup on Saturday Vent to atmosphere on Sunday (or Monday AM). Vent to atmosphere on Sunday (or Monday AM). Dismount Bell on Monday 18th. Dismount Bell on Monday 18th. Park Bell on Tuesday 19th Park Bell on Tuesday 19th Prep for Washing DX on Weds 20th Prep for Washing DX on Weds 20th Wash DX on Thursday 21st AM (with enough manpower, we might be able to wash DX on Weds 20). Wash DX on Thursday 21st AM (with enough manpower, we might be able to wash DX on Weds 20).

4. 20-Oct-2008LBT Q3 2008 Engineering Review

5. 20-Oct-2008LBT Q3 2008 Engineering Review

6. 20-Oct-2008LBT Q3 2008 Engineering Review

7. 20-Oct-2008LBT Q3 2008 Engineering Review Open Issues Technical Technical Documentation for Aluminization System from OSU improved but needs more work Documentation for Aluminization System from OSU improved but needs more work Upgrade of Aluminization System Upgrade of Aluminization System Cleaning/Stripping System Cleaning/Stripping System Glow discharge ? Glow discharge ? Locking devices unreliable Locking devices unreliable LBT personnel can do most of the process now, as long as nothing goes wrong LBT personnel can do most of the process now, as long as nothing goes wrong Nothing really went wrong this time Nothing really went wrong this time Schedule Schedule None None Financial Financial None None Resources Resources None None

8. 20-Oct-2008LBT Q3 2008 Engineering Review Planning (Q4/2008) Next Aluminization Aug 09 on DX Next Aluminization Aug 09 on DX