Chapter/Index: Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Appendix
The energy of electron beam in EMs was discussed on page4787. It is very interesting to consider some real numbers regarding energy of electron beam through TEM specimen. With a cold FEG at 100 keV, we can put 1 nA into an area of diameter 1 nm. If you convert this current density to units of power (1 watt = 1 J/s), you’ll find that the energy the electron beam puts into this small area of the specimen is nearly 150 MW/mm2. By comparison, the output of a typical electric power-generating turbine is anywhere from 350 to 1000 MW. If all this energy were in fact absorbed by the TEM thin specimen the TEM technique would be useless since the specimen would vaporize.
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