Instructions for Use of the Scanning Electron Microscope (SEM)

Starting Up and Shutting Down the SEM


NOTE. The SEM can be shutdown in two modes: Yellow (or partial shutdown) leaves the water chiller and electronics board running but shuts down the computer and the pumps. Red (or full shutdown) turns everything off. If shutting down for an extended period of time or if you experience a computer or electronics error that you cannot resolve, shutting down to Red is recommended.


  1. Sign the User Logbook each time you use the SEM. Record the time you start using it.
  2. If there is a N2 gas tank present, open the main valve by turning the knob a half-turn counterclockwise.
  3. Before turning on the SEM, perform the following checks:
    1. N2 tank pressure: 3 � 4 psi (lefthand gauge)
    2. N2 level: please alert Cathryn or Rachel if the N2 gas level is empty or almost empty (righthand gauge)
    3. Water chiller:
      • Red light ON (power is on)
      • Orange light ON (water tank is full)
  4. Turn on the SEM:
    1. If shutdown to RED: Press the yellow button on the front panel of the SEM. Give the pumps 1-2 minutes to warm up, then proceed to next step.
    2. If shutdown to YELLOW: Press the green button on the front panel of the SEM. This will turn the lefthand computer on. This computer runs the LEO software that operates the SEM.
  5. Turn on the righthand computer if you plan to use EDS or EBSD.
  6. Start up the SEM program by double clicking on the LEO UIF icon on the desktop. Enter the username and password.
  7. Open the Control Panel (Ctrl-G).
  8. Go to Gun and choose Beam State = Beam On.
  9. Align the gun and adjust the filament saturation as needed.


Before shutting down, make sure the chamber is pumped (closed) and the beam is off!

  1. In LEO UIF, go to File > Logoff. Select Yes to close UIF. Select Yes to save SEM conditions if you would like to keep the modifications you made to gun alignment, filament saturation, kEV, etc.
  2. Close out LEO SRV-32 window. Select OK to shutdown SEM.
  3. Press Yellow button on front panel of SEM for partial shutdown. The lefthand computer will shutdown as well.
  4. If you want to shutdown completely to Red (see note above), shutdown to Yellow first. Wait until you hear the pumps release pressure (the hum will get softer), then press the Red button on front panel of the SEM.
  5. Close main valve on N2 tank.
  6. Record end time in User Logbook.