Basics of Scanning Electron Microscopy: Secondary Electron and BSE imaging mode

  1. To start, work with the menu, instructions and icons on the left side of the screen (or the simulator tab).

  2. Start the instrument by clicking the “Power On/Off” button.

  3. Select one the "available material" tab in simulator and drag and drop the material in the marked region (on the bottom portion below the scanner). There are 4 materials available namely "Metal", "Powder","Hair" and "Ceramic Sample". Once the sample is appropriately placed, you will be ready to go to next step.

  4. After placing the material, set the vacuum to the required range. Note that vacuum level of ~ 10-5 torr is needed for the instrument to get started. Lower vacuum level will lead to scattering of electron beam, and image will be poor.

  5. Start the beam current (near the filament) so the electrons can be generated. Usually this current is optimised to obtain highest brightness at lowest current value so the life of filament can be extended.

  6. Once the vacuum level is attained, and beam current is on, set the accelerating voltage (typically 15-20 kV for conducting materials, and ~5-20 kV for gold/carbon coated insulating materials).

  7. Click the “Beam On/Off” (to open the Wehnelt cap and remove the Faraday cage) and start the beam (i.e. incidence of electrons) on the sample.

  8. Select Secondary Electron Image (SE) or Back Scattered electron image (BSE) on top. The default is SE image. These two settings can be swapped for imaging.

  9. Adjust the brightness and contrast of the image using the provided buttons.

  10. Record the image by using save button.

  11. For shutting down, switch off the beam by “Beam On/Off” button, release the vacuum button, and remove the sample, and click the “Power On/Off” button. These buttons are not to be clicked when imaging is on. These create a sudden shock in the instrument and lowers its life. It is very important to follow the reverse sequence during shutting down of the equipment.