August 29, 2007: Snowflake under electron microscope

[Beest]

I usually try and do this at least once each winter, personally I'm going for catching a falling flake, and imaging it without any prep. All that freezing with liquid nitrogen and bombarding with ions might change the structure.
Then again I haven't been successful yet.

Originally Posted by Scriveyn

I had been wondering how they did it, beacause electron microscopes can only image objects whose surface is electrically conductive. -

Modern (for at least the last ten years) electron microscopes can image non conducting objects by using a low gas pressure in the chamber, incoming beam ionizes the gas around the beam providing a conducting path to dispel charge.

Low beam currents, and accelerating voltages, also help reduce sample charging in the Field emission type SEMs.

I bet you're sorry you asked now