Elmitec LEEM V

Notes

***When changing to/from 100 um FOV or LEED Wehnelt must be turned up to 800V otherwise you risk serious damage to the channel plates!!!***

Elevated Pressures (main chamber)

First consult with staff before working at pressures above 1E-7 Torr.

If the pressure will exceed 1E-7 Torr:

Open the gate valve to the main turbo if it is not already open.

Turn off the main chamber ion pump.

If pressure will exceed 1E-6 Torr you will need to bypass the setpoint override. Otherwise, the system will shutdown all power supplies including the heating power supply, image intensifier, electron gun, etcetera. This will delay your experiment as some power supplies have to be ramped up very slowly.

When you return to <1E-7 Torr, turn on the ion pump.

You may leave the main turbo gate valve open, but be certain to close it at the end of the day.

Sample Heating (main chamber)

Max filament current = 2.75A

microCMA Instructions

1) Turn on the power supply in the rack

2) Load the "CMapp" software

3) Click on the "egn" icon in the toolbar

4) Press the "filament on" button

5) Ramp the filament up to 1.003 Amps

6) Press the "2kV" button

7) Place the sample under the microCMA and drive the microCMA so that it is about 3mm from the surface of the sample

8) Select "Acquisition" --> "New alignment peak". The default settings from 1950-2050 eV are sufficient. Press "Acquire"

9) Adjust the z-position of the microCMA until the maximum in the alignment peak is centered at 2000 eV. Then press the red square button to stop.

10) Select "Acquisition" --> "Survey" and choose the parameters for your scan. Do not go below 20eV.

11) At the end of the scan you will be presented with a save dialogue to save the native ".adn" file.

12) After saving the native file click "File" --> "Export text" to save a text file that can be loaded into other programs.

13) After you are done turn off the high voltage and ramp the filament down to 0 and then turn off the filament. Finally turn of the power supply in the rack.

14) Retract microCMA completely to prevent any accidental collisions.

Saving LEEM/LEED Data

1) In the lower right hand side of the toolbar menu in the U-View 2002 software select the "..." to open the "file save directory".

2) Create a new folder with today's date in the format "YYYYMMDD_##_Description"

3) After the new folder is created enter the filenames in the "file name" dialog box with the following format "YYYYMMDD_##_Description_" . The last underscore is important.

4) After saving the file the directory in the bottom right of the toolbar at the top of the screen should show "C"\.....\YYYYMMDD_##_Description_"

5) Just to the right of the file directory set the counter to "0" and change "every" to 10. Typically we will record an image every 10 seconds.

6) When you are ready to record change the dropdown box next to "every" to seconds. This will record an image every 10 seconds or whatever you had set in step 5.