|
|
|
CHROMATIC
ABERRATION in the TEM:
|
|
|
|
In LM results in
“color fringe” in cheap lenses.
|
|
|
|
In TEM,
short-wavelength, high energy electrons have a longer focal point than
long-WL low-energy ones.
|
|
|
|
Result in
degraded focus.
|
|
|
|
Corrected by
using only a single WL of electrons, with a stable acceleratiing V and good
vacuum.
|
|
|
|
THICK SPECIMENS
can cause CA by absorbing electron energies unequally.
|
