Environmental scanning electron microscope (source code)

= Environmental scanning electron microscope
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= ESEM
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A scanning electron microscope permitting a controlled gaseous specimen environment while maintaining the electron column at lower pressure by differential pumping. Ionization of the gas supplies positive ions that can neutralize negative specimen charging, and a suitable gaseous detector collects electron signals. This enables examination of some nonconducting uncoated specimens, with gas scattering and detector response included in interpretation.