1. SAC Report Povilas Palunas 2/23/2012 1

2. Primary Mirrors Primary Aluminizing Schedule back on track –Baade aluminized in Jan after 4 years. 3% gain over washing. –Modifying CO 2 cleaning procedure to improve uniformity Baade M3 washed due to failure of du Pont tank –Reflectivity 88.3% in blue compared to 91.7% for the freshly aluminized primary. ADC cleaned with acetone – the coatings are failing. 2/23/2012 2

3. Earthquakes! Two significant earthquakes –Nov 14 end of f/5 run--starting AO commissioning Mag 6.1 epicenter 59km depth 61km –Jan 30 end of Baade wash Mag 6.7 epicenter 94km depth 47km Both quakes had an effect on Clay collimation –In the second quake the secondary required 1mm offset to remove coma. In the following engineering the position values were back close to nominal. 2/23/2012 3

4. Transparency Started projects to monitor site transparency. –DIMM poor sky coverage but limited number of stars and systematics –CASCA full sky coverage more systematics and data handling Project completion is resource limited 2/23/2012 4

5. f/5 Changeovers becoming reasonably routine –Primary issue is scheduling Juan Gallardo f/11  MegaCam takes more than one day but on sky engineering done on the first night Telescope collimation easier with MegaCam 2/23/2012 5

6. AO Run Guider functional but not complete Glycol above the primary –Controls installed to stop a system leaks Vibrations –Primary Mirror Cooling system glycol pump –CLIO LN2 vacuum pump (will be moved) –AO CCD cooling circuit (?) Rotator control problem –Rotator not tracking to spec after telescope offsets 2/23/2012 6

7. GMT Supported GMT primary mirror phasing camera test run Other –Primary mirror Temperature distribution –Adaptive optics performance –Test of coarse lenslet array –Telescope Vibration –Dust analysis –Weather 2/23/2012 7

8. Space We are filling up. 2/23/2012 8 To ASB

9. Safety Two accidents on site this year: –Chemical spill –Broken leg Hard hats and safety shoes required for everyone at lifts and moves. Working on official procedures for all major tasks New safety system –Cell cart scaffold –Primary mirror cover access –Inner catwalk (for 2 nd changes) 2/23/2012 9