The ISAC β-NMR HomePage



Introduction to β-NMR
Publications
Students Projects
Contacts
Technical Information
Data Acquistion
Approved Experiments
Internal Page
Related Links
BNMR Wiki
Data Analysis
Photo Album

  • Download BNMRfit istallation script
  • Download BNMRfit
  • Download BNMRminfit

  • Loading NMR in an empty cryostat next up previous contents
    Next: Shutting down the NMR Up: Changing and aligning samples Previous: Getting out a sample   Contents


    Loading $ \beta $ NMR in an empty cryostat

    If the load lock is under vacuum, vent it through SVV5 (see figure above) note there is a manual valve in line with this automatic valve. Remove the blankoff on the top of the lock by undoing the three bolts with the allan key located on the side of the lock. Keeping the rubber o-ring in place, mount the clean end of the manipulator into the vacuum lock and seal it using the three screws and the allan key. Do not get the manipulator's clean end dirty by touching it with your bare hand for example. Rough out the lock: Go To the Control Room and Get the operator to open up the EPICS page shown above. Make sure the vent valve SVV5 is closed. Turn on the roughing pump if it is off. (the round black circle BNMRBP5 above should be green). Note the Fuji dry roughing pumps are often switched off due to their short lifetimes. If the roughing pump is working the convectron gauge BNMRCG5 should go down to some low value like 50 mT - that's T for Torr. Open the valves to the lock: PV5, RVX6 and RV5. You can watch it rough down on the convectron gauges CG6A and CG5D. Rough out the backside of the sliding seal:

    Ensure the KF25 flexible pumping line is connected to the flange on the side of the manipulator. Close RV5. Note typically the lock pressure comes up when you isolate it due to outgassing this can be seen on CG5D. Open RV7. Watch it pump out on convectron CG6A.. Spin Up the Turbo Pump BNMRTP6 - the yellow circle above You need to back it with the roughing pump first, close VX6 then open BV6. When it is safe, open the inlet side of TP6 using GV6. Pump out the lock and the backside of the sliding seal: Let it pump for a while, then close RV7 and start pumping on the lock (open RV5). Pump the lock for  15mins. The gauge CG5D will quickly bottom out, but after a while you can turn on the ion gauge IG6 at the turbo and watch it come down to a few microTorr.

    Prepare to open the gate valve: Turn off the ion gauge IG6 to protect it. Close RV5, isolating the lock. Then QUICKLY open RV7 to pump on the "differential space" at the back of the sliding seal. If you are too slow the TP will trip off and you have to turn it back on. Note when the manipulator is going into the UHV space, you must pump continuously on the differential space with the turbo Let it pump for a minute or two Open the gate valve (SLV5) now the lock is open and the UHV is spoiled (not badly if you have followed the above) Go to the platform push the manipulator down, opening the hatch if you haven't already Using the motor and the side-to-side play of the bellows on the lock. position the manipulator directly over the threaded hole in the sample holder. Screw the sample in: note this is a normal thread, so you turn as if you were taking it in (pressenig gently to engage the threads). This is Clockwise! Once the thread is fully engaged, the inner reverse threads will begin to pull out. Continue turning the same way until the manipulator is free. Retract the manipulator (without the holder) into the lock all the way. ENSURE that the manipulator is up by using the brass rod to keep the manipulator handle at the necessary height Once this is done, close the gate valve from the control room SLV5. Turn off the turbo pump, and then turn off the roughing pump.


    next up previous contents
    Next: Shutting down the NMR Up: Changing and aligning samples Previous: Getting out a sample   Contents
    BNMR Web Site 2006-06-29



    Page last modified: 07/23/09 02:45 by Andrew MacFarlane.