Chandra requested that a witness plate be put in the output tube section under a port where a proposed new VE pump will go.  This morning, while closing out HAM4, I went in and laid this plate (in a horizontal holder) in the specified location.  Pictures below.  While doing this, I also inspected the floor and found many large particulate pieces.  I spent some time carefully wet wiping, and picking up (with tweezers) fuzzies, fibers, and other bits, which were along mostly the central part of the tube.  All of this is has likely been tracked in from the trips down this tube for work.  I am skeptical of the in-chamber shoes which are top of my list as being the probable fuzzy contributor.

Note, the last witness plate picture is just showing the particulate I removed from the tube and brought out to dump on a wafer for easy inspection.  Looks to be fuzzies, glove bits, metal, body parts... usual stuff.