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Primary vacuum

Preparation 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

Pumping 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)

Both Ebara pumps will start running in MAIN mode. On the striptool graph, the target chamber Pirani gauge value should drop rapidly. Once pre-pump Pirani gauges (MEZ-GPI-06 and MEZ-GPI-07) drop below 7.5e+00 torr, the Ebara pumps will start running in BOOSTER mode (typically after 10-15 minutes from startup). The primary vacuum procedure is finished when the target chamber Pirani gauge (MEC:TC1:GPI:01) drops below 5.0e-02 torr (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 procedure

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.

  • Open mechome
  • Go the tab "User Devices"
  • Open the panel "User Sentry PDU"
  • Turn On "Roughing pump PTM 02 (turbo 2)"
    - after a while, scroll to turbo gate-valve (SEW-VGC-15) will switch to allowed to open.
  • Press OPN on SEW-VGC-15
    - turbo status goes to "OK to Run"
  • Press RUN next to the turbo pump logo
    - turbo status will go through "Accelerating" then "Full Speed" mode

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

The target chamber is now fully pumped down, ready to be exposed to the x-ray beamline through the beryllium window system.

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