[Sem] scanning electron microscope practicals

[Andy Isaacson]

The SEM that Mike is proposing to donate consists of two gross objects:

1. a relay rack, about 19" x 24" x 48" tall
2. the instrument itself, about 6" x 9" x 16"

They can be stacked or the instrument can be installed on a workbench
near the rack.  The rack needs to be kept clean but is reasonably
resilient, while the instrument needs to be in a dust-free and
vibration-free environment.

So we're proposing to put the rack on the floor and build a vibration
isolation table using some innertubes and some MDF to hold the
instrument.  The table will have a plexiglass cube approximately 24" on
a side to keep the instrument in a clean space.

The plexiglass shield will have a few openings, one for a fan and air
filter (since the instrument is air-cooled the box can't be airtight),
a door for instrument access without having to remove the shield, and a
port for the power cord/vacuum hose/signal line to exit.

Mike will build the isolation platform, and I'm going to get a quote on
the plexi from Tap Plastics -- if it's cheap I'll just have them build
it rather than muck with it myself, but I suspect that'll be too
expensive and I'll come away with some plexi and some adhesive.

Current thinking is to install it on the northern wall about 10' west
of the "DJ Booth" stairwell, where there are currently some tables used
as storage.  I expect the footprint will be approximately 3' deep and 6'
wide for table and rack, with some additional clearance needed for
operator's chairs etc.

-andy