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
| Critical ionization energy is also known as absorption edge energy, critical excitation energy, or X-ray absorption energy. The characteristic energy is value measured by our X-ray detector. The value of the critical ionization energy (Ec) is higher than the associated characteristic (line) X-ray energy. The origin of the difference is because the atom doesn’t return completely to ground state when an X-ray is emitted. For instance, if the electron that fills a hole in the ionized inner shell comes from an outer shell this process will leave a hole in that outer shell. This hole will essentially be filled by another electron with perhaps the emission of another X-ray and so on until eventually a free electron from the conduction or valence band fills the last hole in the outermost core shell.
|