Acquiring SE (Scanning Electron) And BSE (Back-Scattered
Electron) Images

The techniques used for collecting SE and BSE images are very similar, although the setup of the system is a bit different for the two image types.

For collection of both image types, Scanning must be ON. Scanning can be turned on using the toggle on the Roller Control window, or the one in the General window.

Backscattered Electron Imaging

Backscattered electron imaging gives you a picture of the mean atomic number of the area that you’re imaging. It is very useful for working on polyphase samples, or samples that are chemically zoned.

Turn beam current (I) to 20 nA (Roller control window or General window)
Go to the SEM tab on the main SX Control window. This is the large window on the left-hand screen that opens when you LC on “General”.
Set Acquisition to 1
Set Resolution to 1024x768
Set frame time to 1.067 seconds
On the rectangular box under the “Acquisition” button, RH and set the video channel to VS1. This should be labeled BSE-Z.
Remove Faraday cup (SX Control window or Roller Console)
Turn magnification down (Roller Console or SX Control window)
You will now need to adjust contrast and brightness. To do this, look at the Roller Console (the physical panel with wheels and buttons). There is a button in the upper left corner labeled VS1/VS2. Toggling this button until the area labeled “Roller” on the SX-Control Roller window reads VS1. Now you can move the wheels on the console to adjust brightness, contrast and “Offset” (which adjusts brightness and contrast together).

Secondary Electron Imaging

Secondary electron imaging gives you a 3-D picture of your sample.

Turn beam current (I) to 1 nA (Roller control window or General window)
Go to the SEM tab on the SX Control window
Set Acquisition to 1
Set Resolution to 1024x768
Set frame time to 1.067 seconds
Set the video channel to VS2
Turn Secondary Electron Detector ON (select the appropriate video channel, and the SE on/off toggle will appear in the lower right of the screen).
Remove Faraday cup (SX Control window or Roller Console)
Turn magnification down (Roller Console or SX Control window)
You will now need to adjust contrast and brightness. To do this, look at the Roller Console (the physical panel with wheels and buttons). There is a button in the upper left corner labeled VS1/VS2. Toggling this button until the area labeled “Roller” on the SX-Control Roller window reads VS2 (the uppermost box will be labeled SE PM. Now you can move the wheels on the console to adjust brightness, contrast and “Offset” (which adjusts brightness and contrast together).
WHEN DONE with imaging, TURN THE DETECTOR OFF

Preparing to Save and Print Images

Go to the SEM tab on the SX Control window
Have the image that you want on the Sony monitor
Select a frame time of 12.8 seconds
LC in the small white box in the upper left corner of the larger black box. This will freeze the image.
When the image is frozen, a box that says “Save & Display” will appear to the right of the black box. LC on the “Save & Display” box.
A window will now appear that will allow you to save the image as a Cameca file. Give the image a name and then save.
The image will now appear in a window labeled “SXResults”. From here you manipulate, print or save the image.

Printing Image

Go to the Windows “File” area
Select “Print Setup”
The first time that you’re printing, go to Print Setup and select conditions. Landscape is probably the best format for printing images.
Select Print

Viewing an X-ray map

Be imaging an area around 100-200 microns, or less
Go to SEM tab
Select 4 in the Acquisition area
Select the elements that you want on the WDS tab
Go to a long frame time (26.5 or 51.2)

“Move To”

“Move To” is a useful feature that allows you to click on a point on a collected image, and have the machine automatically drive to that point. This is particularly useful when programming quantitative points to a complicated sample

At the top of the SXResults window, select the image icon (little mountain/sun picture, 2nd from left).
Go to File, Open, select the image that you want
At the top of the SXResults window, select Tools, Move To
From here, you should be able to click anywhere on the image, and the stage will drive to that point. Be aware that the image must have been in optical focus when you collected it in order for the points that you drive to to be in optical focus each time.

Saving Image

At the end of an analytical session, you can save all of the images that you collected that day in a TIF or JPG format.
Go to the “File” menu item on SXResults.
Select Save (merge) images.
Select “Save all images from Dataset”
Select the appropriate directory
As a file format, TIF (8 bit) or JPG will work. TIF may be a bit better because it save more information.

About us • Publications • Laboratories • Geoscience Info • Archives & Collections

New Mexico Bureau of Geology & Mineral Resources
New Mexico Institute of Mining & Technology
801 Leroy Place
Socorro, NM 87801-4796

information: (575) 835-5420
fax: (575) 835-6333
http://geoinfo.nmt.edu