Which part of a sample interacts with the beam first?

[thomasaarholt]

If a "pretend" sample has two atoms, A and B, with z = 0 and 5 Å respectively, which atom will be hit by the beam first?

Another way of asking the same question is, "is the sample sat with the z-axis increasing towards the electron gun, or increasing away from the gun"?

Stealing @cophus excellent image from prism-em/prismatic#33:

This is important for my application.

[Ivanlh20]

Hi Thomas, atom A will be hit first by the beam.

[thomasaarholt]

Great, thanks!