Vacuum Beampipes in 7ID Hutches
The x-ray beam flightpaths in the 7ID hutches of MHATT/XOR can be
evacuated with roughing pumps. The pipes are 2" diameter aluminum
or steel with KF50 flanges. Analog vacuum gauges are installed at
various points along the flightpaths to check that there are no
leaks. (Electronic gauges that can be incorporated into the
beamline's EPS system are being developed.) Windows at the ends
of the flightpaths can be Kapton (R) foil (not Kapton tape) held with
superglue (not epoxy) or Be on specialized flanges. Some pipes
have valves that can be used to bleed air into them once the pump is
turned off; these are located right next to the pumps.
The entire length of the B hutch can be under vacuum. There are
several stages of
offset adapter nipples on the upstream and downstream walls to adapt
from large Conflat flanges to the KF50 flanges of the beampipe.
The offset flanges may need to be rotated to match the beam height in
white-beam mode; the photos below are for monochromatic mode.
To protect the Be windows at the ends of the hutch against oxidation,
they should always be hooked up to beampipes that are evacuated.
That is, remember to turn the pump on! (Or, two pumps, if there
are two sections of beampipe.)
The upstream end of the beampipe is under Configuration Control and
cannot be adjusted without contacting a Floor Coordinator and obtaining
the proper permissions.
When the entire length of the hutch is evacuated, a short KF50 bellows
must be part of the flightpath (it's hard enough to find the right
lengths of beampipe, and they usually don't quite line up perfectly).
The 7ID-C hutch is not yet configured to support evacutated beampipes
along its entire length. So it must start with a window on a
flange. When the beam is being ported all the way into the D
hutch, then the beampipe can butt up to the 6" Conflat flange on the
wall and be attached using bulkhead clamps.
The beampipe coming into the 7ID-D hutch attaches to the 6"
Conflat-to-KF50 reducing flange attached to the upstream wall.
The short tee with the pressure gauge should be left in place.
Choose the appropriate length of beampipe and end it with a window
Don Walko, MHATT/XOR, APS, ANL
Last updated January 9, 2006