Travis, Margot, and Kate

Removed the horizontal 4" wafer from the beamtube (between the purge air port and ACB). The 1" optic that was placed with the wafer couldn't be removed (no PETG containers available), so it was moved to the opposite tube for the time being. When possible, it should be moved back to its original location or removed. A new 1" optic (s/n 1195) was mounted vertically to the QUAD.

Refer to Betsy's earlier alogs on contamination in BSC10 (10522, 10675 & 10686). There is still a lot of particulate contamination, even after cleaning. The first photo shows a wipe used to clean the tube on Monday. Dust, metal, a few red fibers, and white fuzzies were observed on the tube floor from the ACB all the way to the PCAL periscope. The iphone photos and videos don't really do it justice. There was a much higher concentration of white fuzzies along one half of the tube (on the right side, if you have your back to the ACB and are facing the periscope). Travis took an FBI sample, and then vacuumed the area.