DECam Filter/Shutter Installation and Filters Installation Alistair Walker Internal Review August 9 2012

Internal Review August 9 2012 From August 20… We commence prime focus cage build-up, including installation of the Imager, and test that it all works. This is called “Commissioning Phase I” and ends with Technical First Light. Nominally this is September 28, but we hope to be earlier. The task list can be summarized as: Install the Filter Control Module and the Shutter (together) Install the six filters and the two filter mass models Install the BCams, install the DECal system etc on the top ring Install the Imager Run full system tests Internal Review August 9 2012

Filter/Shutter unit, & Filters We need to position the telescope in the N position, so that the in-out axis is horizontal This is not so easy The filters are installed from both sides (i.e. four from one side, then four from the other) The filters cost $500,000 and (now) typically take ~ a year to procure (from Asahi) In the future we may have more than 8 filters We need to service the mechanisms annually Internal Review August 9 2012

Internal Review August 9 2012 Work Schedule Aug 20 Monday: i) telescope at NW platform (ii) attach filter control boxes and filter-changer covers to the barrel (iii)Bolt shutter to filter-changer (on C floor, need crane] (iv) Install F-S installation hardware at N platform or else do first thing Tuesday. Scissor Lift arrives. Aug 21 Tuesday: (i)Install the F-C & shutter need crane plus lift access both sides, ref doc 5428, (ii) Remove installation hardware (TCS tests possible - night) Aug 22 Wednesday: Telescope at N platform, install 2 dummy filters and 2 real filters. (TCS tests possible- night) Aug 23 Thursday: Install remaining 4 filters telescope at N platform, see 4786, re-balance. If time, move to NW platform and start hookup (see Monday). (TCS tests possible - night) Aug 24 Friday: BCams/ (i) telescope at NW platform (ii) install lower BCams near primary mirror(iii) Attach upper BCams to filter-changer covers and align with lower BCams, (iv) test BCams with SISPI ref doc 6232 (v) Aug 25, 26: Contingency Aug 27 Monday: Hook up and test FC and shutter at NW platform. That would need power, compressed air and Ethernet and so might have to wait until the Imager is installed and its utilities completed. (TCS tests possible - night) Internal Review August 9 2012