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

Readiness checklist

Tools necessary for operation

It is necessary to open a couple of windows to be ready to operate the vacuum system. You must be operating from one of the hutch computer (mec-daq, mec-monitor, mec-console, mec-laser, mec-hutch01, mec-laptop08), or you can ssh to these computers.

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mechome

In a terminal, type mechome to open the above window. It is the start point of many processes in the MEC system.

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MEC Vacuum

In mechome, in the top left part of the window, press the "Vacuum" button to unfold the menu, then select MEC Vacuum to open the above window. It will be used to operate the pumping system components: pumps, gate-valves, etc

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tc_vacuum

In a terminal logged as mecopr, type tc_vacuum to open the above window. Often called "striptool", this type of window can display the time evolution of some environmental parameters. Here it shows 4 curves monitoring the pressure value read by 4 different gauges. You can reshape the window and change the time axis range to monitor pressure values over a long time span (~ 1 hour). The curves correspond to the following gauges:
MEC:TC1:GPI:01:PMON   → target chamber Pirani gauge
MEC:TC1:GCC:01:PMON → target chamber Cold-cathode gauge
MEC:SEW:GPI:03:PMON → scroll pump Pirani gauge (Maglev roughing)
MEC:SEW:GPI:04:PMON → scroll pump Pirani gauge (Varian turbo roughing)

Primary vacuum

Prerequisites

• All chamber doors must be closed

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•  All chamber

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• flanges must be

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• in place (no obvious opening)
•  TC1:VGC:11, TC1:VGC:12, TC1-VGC-01, TC1-VGC-02, TC1-VGC-03, TC1-VGC-04

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• must be closed
•  MEZ-PMF-01 EBARA A70, MEZ-PMF-02 EBARA A70 must be off

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• (if faulted, press RESET

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• )
•  TC1-VGC-04, MEZ:VGC:17, MEZ:VGC:18, MEZ-VIC-19

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• must be

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• closed
•  MEZ-GPI-02

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• must display ~ 6.5e+02 torr

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• (if lower,

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• open MEZ:VGC:18

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• until

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• restored, then close)
•  TC1-VGC-04, MEZ:VGC:17, MEZ:VGC:18, MEZ-VIC-19

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Primary vacuum pumping procedure

• 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

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•  Press RUN on MEZ-PMF-01

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• EBARA A70
•  Press OPN on MEZ:VGC:17 (

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• wait a few seconds if MEZ:VGC:17 cannot open

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• )
•  Press RUN on MEZ-PMF-02

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• EBARA A70
•  Press OPN on MEZ-VIC-19 (

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• wait a few seconds if MEZ-VIC-19 cannot open

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• )
•  Wait until MEC:TC1:GPI:01

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• 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

(typically after 30-40 minutes from startup).If something goes off track during this procedure, initiate the venting procedure and check for leaks (flanges, virtual leaks, waterlines, etc).

Secondary vacuum

Turbo pump startup

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This procedure can be done anytime as long as the turbo gate-valve to the target chamber is closed. The following steps assume that the turbo pump branch is fully shutdown (scroll off, scroll to turbo gate-valve closed, turbo off, turbo to target chamber gate-valve-closed). If the system is in an intermediate state, you can restart the following procedure from the corresponding step. In this example, we consider only turbo pump #2 associated with gate-valve TC1-VGC-02.

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•  Open mechome, go to

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• the tab "User Devices"

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• , open the panel "User Sentry PDU"

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•  Turn On "Roughing pump PTM 02 (turbo 2)"

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•  Wait until SEW:GPI:04 drops below 1.0e-02 torr
•  Press OPN on SEW-VGC-15

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•  Press RUN next to the turbo pump logo

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•  Wait until turbo pump displays "Full Speed"

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The turbo pump subsystem is now ready for operation.

Prerequisites

• Turbo pump subsystem must be up and running as described above.
• Primary vacuum pumping procedure must have been completed.
• Target chamber Pirani gauge (MEC:TC1:GPI:01) must be below 5.0e-02 torr.
• On the striptool graph, the target chamber Pirani gauge curve should look asymptotic, meaning the primary vacuum subsystem has reached saturation.

Secondary vacuum pumping procedure

• Press OPN on TC1-VGC-02
  - primary vacuum gate-valve will automatically close first, before turbo gate-valve opens → do not forget the primary vacuum shutdown procedure below
  - target chamber Pirani gauge value should plummet, until it goes out of range and the target chamber cold-cathode gauge takes turn
• Press STP on both Ebara pumps
• Press CLS on MEZ:VGC:17 and MEZ-VIC-19
• Press OPN on MEZ:VGC:18
  - primary vacuum line will start venting
  - wait until Pirani gauge MEZ-GPI-02 goes above ~ 6.5e+02 torr
• Press CLS on MEZ:VGC:18
  - primary vacuum venting valve should not stay open longer than ~ 5 minutes as it may heat up too much

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