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These vacuum procedures are primarily based on the "standard" BAMBINO configurations used for the first several TIGRESS experiments. It should also be relevant for the SHARC. The instructions MAY need customization n the future with more sophisticated vacuum configurations or gas counters.

[edit] EPICS Graphical Interface

ISAC2 Commissioning Window, about to select SEBT3A

All controls are performed through the EPICS interface, which displays on any X-type display terminal (Linux, or Cygwin after startx).

• ssh -X tigsebt3a@isacepics1 (or use -Y on Cygwin)
• The ISAC2 Comissioning Menu will appear. Click on the SEBT3 button. A small popup window will appear. Select SEBT3A, as shown.

Typical SEBT3A_0 vacuum window. Target chamber has been vented and is at atmosphere.

• The SEBT3A_0 Vacuum page will now appear. This page allows you to control the vacuum.
  • Real physical devices are represented on the EPICS page by an icon of some sort. Typically, there will also be a black box with grey lettering with the EPICS name of the device. Clicking on the black box will bring up a control window that provides more information and actions.
  • Often the main page will also have grey 1 and 0 buttons that can be used to turn devices on or off, and a blue readback value. This provides a shortcut so you don't have to pull up the control window for a specific device every time you want to do something with it.
  • Device icons are colored black for off, bright green for on, yellow for interlocked, and red for malfunctioned. Some devices will appear dark green with white outlines while they are transitioning between on and off.
  • Valves are normally closed, and a valve that is "off" is closed. That is, closed valves are off, and open valves are on. Interlocked valves are (usually) closed. Malfunctioned valves can be in an indeterminate state.
• You can also use the " Utilities" button to o the Commissioning Menu window to start a Striptool.

[edit] Pumping Down

• First make sure everything is "buttoned up".
  • 

    

    BAMBINO closed up. Note arrows.
    For BAMBINO: Make sure the target ladder and side piece are both installed. It is recommended to clean the o-ring, groove, and surfaces before installation. Make sure the red arrows on the main vacuum chamber and the side piece are aligned.
• The page should closely resemble the "Typical" window shown above. In particular, make sure that the roughing and backing pump SEBT3A:BP6, the backing pump main valve SEBT3A:CG6B, and the backing vacuum guage SEBT3A:CG6A are all green as shown.
  • Do not be concerned that SEBT3A:IV5 is red. This valve is currently mechanically forced open and should never be closed.
• Close the constricted vent valve SEBT3A:VV6 by clicking the 0 button underneath its name.
• Open the roughing valve SEBT3A:RV6 by clicking the 1 button underneath its name.
• The pressure on SEBT3A:CG5 and SEBT3A:CG6 should fall rapidly (a few Torr/s) at first. The turbo pump SEBT3A:TP6 is interlocked so that it can only be turned on when the vacuum in the beam dump chamber (i.e.,SEBT3A:CG6) is below 300 mTorr. This can take up to half an hour. You may close SEBT3A:RV6 at this point; however, it is recommended to wait until it closes automatically at 100 mTorr.
• Open SEBT3A:BV6.
• Turn on SEBT3A:TP6. The turbo will begin to spin, as indicated by turning dark green with white outlines. After a few seconds, the pressure in the target chambers should begin to drop and the pressure in the backing line should briefly rise. (If this pump is interlocked and cannot be started it must first be reset. To do this click on the device name in the black box to bring up its control panel, then click the RST button. Now click 1 to start it.)
• After a few minutes, when the turbo pump is at full speed, the turbo will turn bright green.
• Turn on SEBT3A:PNG5 and SEBT3A:PNG6. THIS SECTION HAS SOME IMPORTANT GOTCHAS. READ IT CAREFULLY.
  • The gauges take about 15 to 30 seconds to turn on.
  • If they are operating properly, they will read back a pressure in the range of 5.00e-4 to 1.00e-6. The high end is typical of a freshly-pumped vacuum system.
  • IF THE GAUGE REPORTS AN UNUSUALLY LOW VALUE BELOW 5E-8, IT DID NOT TURN ON PROPERLY. TURN IT OFF RIGHT AWAY.
    • The gauges have a failure mode where they end up reporting a reading of 9.11e-9 or 2.20e-8 or something similarly way too low. They will continue reporting this value until they are turned off. If the situation is not corrected, experimenters and ISAC operators (and more dangerously, the ISAC interlock system) may think the vacuum is good, when in fact it could be in any state -- even at air. As such, if the gauge is reading below 5E-8, TURN IT OFF RIGHT AWAY.
  • The gauge may also time out, in which case its icon will turn red. To clear this malfunction, click on the device name in the black box to bring up its control panel, then click the RST button.
  • Wait five minutes before attempting to turn on a gauge after it has malfunctioned. Keep trying (and waiting) until each gauge is reading a sensible value.
• When both SEBT3A:PNG5 and 6 are reading sensible vacuum values (above 5e-08 Torr), you may call the ISAC operators and ask them to open SEBT3A:IV4. This may help pump the beamline faster. More importantly, it is necessary to deliver beam. This opens the chamber to the beamline. It is recommended to wait until the vacuum is "good".

[edit] Venting

• DO NOT vent during or just before the automated Ge fills.
• Bring up the tigsebt3a@isacepics1 window as described in the EPICS Graphical Interface section above.
• 

  

  Good vacuum, after closing SEBT3A:IV4
  Call ISAC Operations (7500 or 7557) to inform them that you intend to vent the vacuum chamber and instruct them to close SEBT3A:IV4. This isolates the experiment vacuum chamber from the accelerator and beam-delivery part of the beamline.
• Make sure everything is safely prepared for venting. This varies from experiment to experiment, and details of these steps may be documented elsewhere, such as in the elog. Some example of typical things to do before venting are:
  • Make sure that the band around the BAMBINO is secured, as the chamber will otherwise fall apart when not under vacuum.
  • Remove bias from target ladder if any (BAMBINO).
  • Turn off bias on Si detectors (SHARC, BAMBINO).
  • Verify that the channeltron bias is off (Beam dump), see first blue cabinet by ISAC II vault entrance.
  • Remove power from zero-degree scintillator (Beam dump).
• Turn off Turbopump SEBT3A:TP6.
• Check that: SEBT3A:PNG5 and SEBT3A:PNG6 are turned off (interlocked with turbo pump).
• Check that: SEBT3A:BV6 is closed (interlocked with turbo pump).
  • Note: As these steps are followed, some devices may turn yellow, indicating that they are interlocked. This is normal.
• Hook up a dry nitrogen line to the vent valve.
• Per standard ISAC operations, allow the turbo to spin down for 10 minutes
• Open valve SEBT3A:VV6
• Wait until the values on SEBT3A:CG5 and SEBT3A:CG6 approach and stabilize near 770 T.
• If this is the first time you have vented since beam of any sort was delivered, you must do a swipe test. Call someone on the group contacts page with a respirator icon next to their name for further instructions.