Note a conflicting procedure / documentation in the procedures folder: 9.8.3 Pumping/Venting Procedure . These are being reconciled.

Readiness checklist

•  All chamber doors must be closed
•  All chamber flanges must be in place (no obvious opening)
•  TC1:VGC:11, TC1:VGC:12, TC1-VGC-01, TC1-VGC-02, TC1-VGC-03, TC1-VGC-04 must be closed
•  MEZ-PMF-01 EBARA A70, MEZ-PMF-02 EBARA A70 must be off (if faulted, press RESET)
•  TC1-VGC-04, MEZ:VGC:17, MEZ:VGC:18, MEZ-VIC-19 must be closed
•  MEZ-GPI-02 must display ~ 6.5e+02 torr (if lower, open MEZ:VGC:18 until restored, then close)
•  TC1-VGC-04, MEZ:VGC:17, MEZ:VGC:18, MEZ-VIC-19 must be closed and allowed to open
•  The gas ballast control knob of the scroll pump should be set to level 0
•  Turbo pump should be at "Full Speed" (if not follow Turbo pump startup procedurebelow)

Pumpdown procedure

•  Press OPN on TC1-VGC-04
•  Press RUN on MEZ-PMF-01 EBARA A70
•  Press OPN on MEZ:VGC:17 (wait a few seconds if MEZ:VGC:17 cannot open)
•  Press RUN on MEZ-PMF-02 EBARA A70
•  Press OPN on MEZ-VIC-19 (wait a few seconds if MEZ-VIC-19 cannot open)
•  Wait until MEC:TC1:GPI:01 drops below 5.0e-02 torr
•  Press OPN on TC1-VGC-02
•  Press CLS on MEZ:VGC:17
•  Press STP on MEZ-PMF-01 EBARA A70
•  Press CLS on MEZ-VIC-19
•  Press STP on MEZ-PMF-02 EBARA A70
•  Press OPN on MEZ:VGC:18
•  Wait until MEZ-GPI-02 passes above ~ 6.5e+02 torr
•  Press CLS on MEZ:VGC:18

If something goes off track during this procedure, initiate the venting procedure and check for leaks (flanges, virtual leaks, waterlines, etc).

Turbo pump startup

•  Open mechome, go to the tab "User Devices", open the panel "User Sentry PDU"
•  Turn On "Roughing pump PTM 02 (turbo 2)"
•  Wait until SEW:GPI:04 drops below 1.0e-02 torr
•  Press OPN on SEW-VGC-15
•  Press RUN next to the turbo pump logo
•  Wait until turbo pump displays "Full Speed"

Version tracking

System overview

MEC's pumping system is comprised of 2 multi-stage dry vacuum pumps (Ebara A70) located on the mezzanine above the hutch, and 2 turbo pumps (Varian TV-2KG) backed with a scroll pump (Edwards xds35i). The following sketch shows the vacuum system as displayed in the controls window.

Image Removed

The dark grey rectangle in the center symbolizes the target chamber and displays the readout values of different vacuum gauges measuring the in-chamber pressure (top: cold-cathode, bottom-left: pirani, right: capacitance). Let's note that the capacitance gauge is out of order and always displays the same faulted value.

The top right side of the window details the primary pump subsystem. The ends of this branch lead to the 2 Ebara pumps. Controllable gate-valves are positioned at the target chamber entrance to isolate the primary pump subsystem, at the inlet of each independent Ebara pump, and along the line to allow for venting of the subsystem. Pirani gauges are also used to monitor the pressure along the subsystem pumping line and at the inlet of both Ebara pumps.

The bottom side of the window details the secondary pump subsystem. It comprises 3 branches: 2 of them are identical and symmetric on the sketch, and 1 of them (left-most), the shortest with only 3 symbols, is obsolete 

Tools necessary to the pumping procedure

Primary vacuum

Secondary vacuum

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