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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.
  • All chamber ports must be covered.
  • All gate-valves to the chamber must be closed (TC1:VGC:11, TC1:VGC:12, TC1-VGC-01, TC1-VGC-02, TC1-VGC-03, TC1-VGC-04).
  • Both Ebara pre-pumps must be off. If faulted, press RESET.
  • All gate-valves in the primary vacuum subsystem must be closed (TC1-VGC-04, MEZ:VGC:17, MEZ:VGC:18, MEZ-VIC-19).
  • Primary pumping line must be vented with Pirani gauge (MEZ-GPI-02) displaying ~ 6.5e+02 torr. If pressure is lower, use venting valve (MEZ:VGC:18) until situation is restored.
  • All gate-valves in the primary vacuum subsystem must be closed and allowed to open (TC1-VGC-04, MEZ:VGC:17, MEZ:VGC:18, MEZ-VIC-19).

Primary vacuum pumping procedure

  • Press OPN on TC1-VGC-04 (primary vacuum gate-valve to chamber)
  • Press RUN on MEZ-PMF-01 (pre-pump 1)
  • Press OPN on MEZ:VGC:17 (pre-pump 1 gate-valve to primary pumping line)
    - wait until allowed to open if MEZ:VGC:17 cannot open
  • Press RUN on MEZ-PMF-02 (pre-pump 2)
  • Press OPN on MEZ-VIC-19 (pre-pump 2 gate-valve to primary pumping line)
    - wait until allowed to open 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.


Venting

Prerequisites

  • If ending operation with the x-ray beamline, make sure that the pulse picker is closed, stopper S6 is inserted, hutch search is broken and glass window inserted.
  • Stand next to the chamber during the procedure to be ready to react once the chamber is vented and avoid over-pressurization.

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Logical permissions on the gate-valves 

PVFunctionLogical values
MEC:TC1:VGC:11:OPN_OKTarget chamber venting with compressed dry air0: Low=forbidden / 1: High=allowed
MEC:TC1:VGC:12:OPN_OKTarget chamber venting with atmospheric air0: Low=forbidden / 1: High=allowed
MEC:TC1:VGC:04:OPN_OKPrimary vacuum line / target chamber0: Low=forbidden / 1: High=allowed
MEC:MEZ:VGC:18:OPN_OKPrimary vacuum line venting0: Low=forbidden / 1: High=allowed
MEC:MEZ:VGC:17:OPN_OKEbara pump 1 / primary vacuum line0: Low=forbidden / 1: High=allowed
MEC:MEZ:VIC:19:OPN_OKEbara pump 2 / primary vacuum line0: Low=forbidden / 1: High=allowed
MEC:TC1:VGC:02:OPN_OKTurbo 2 vacuum line / target chamber0: Low=forbidden / 1: High=allowed
MEC:SEW:VGC:15:OPN_OKTurbo pump 2 / scroll pump0: Low=forbidden / 1: High=allowed

Pressure gauges

PVFunction
MEC:TC1:GMP:01:PRESSTarget chamber capacitance gauge (out of order)
MEC:TC1:GPI:01:PMONTarget chamber Pirani gauge
MEC:TC1:GCC:01:PMONTarget chamber cold-cathode gauge
MEC:MEZ:GPI:02:PMONPrimary vacuum line Pirani gauge
MEC:MEZ:GPI:06:PMONEbara pump 1 inlet Pirani gauge
MEC:MEZ:GPI:07:PMONEbara pump 2 inlet Pirani gauge
MEC:SEW:GPI:04:PMONScroll (turbo 2) pump inlet Pirani gauge