Periodic Table
X-ray peak intensities
Leverage this quick-reference table for exploring x-ray peak intensities across element series (K, L, M, N) to interpret spectra more accurately, distinguish elemental signals with greater clarity, and make more informed analytical decisions.
Atomic number | Element | Series | K Peak Intensities | L Peak Intensities | M Peak Intensities | N Peak Intensities |
|---|---|---|---|---|---|---|
3 | Lithium | K | Kα = 0.052 | |||
4 | Beryllium | K | Kα = 0.109 | |||
5 | Boron | K | Kα = 0.183 | |||
6 | Carbon | K | Kα = 0.277 | |||
7 | Nitrogen | K | Kα = 0.392 | |||
8 | Oxygen | K | Kα = 0.525 | |||
9 | Fluorine | K | Kα = 0.677 | |||
10 | Neon | K | Kα = 0.848; Kβ = 0.857 | |||
11 | Sodium | K | Kα = 1.041; Kβ = 1.067 | |||
12 | Magnesium | K | Kα = 1.253; Kβ = 1.295 |
Understanding K, L, M, and N series in EDS
In energy dispersive spectroscopy (EDS/EDX), the K, L, M, and N series reveal how characteristic x-rays are generated during electron transitions within an atom.
Each series corresponds to the electron shell where the initial vacancy is created, providing a systematic way to interpret emission lines and identify elements.
Electron shell series
- K series (n = 1): Indicates a vacancy in the innermost shell. These transitions require the highest energy and are most commonly used to analyze light to mid-weight elements.
- L series (n = 2): Represents a vacancy in the second shell. These lines are typically used for mid- to heavy elements, where K-line excitation may be less accessible.
- M series (n = 3): Indicates a vacancy in the third shell. These transitions are relevant for high–atomic number elements.
- N series (n = 4): Corresponds to vacancies in the fourth shell and is used when analyzing the heaviest elements in the periodic table.
Greek letter sub-classifications
Each series is further divided using Greek letters (e.g., Kα, Kβ, Lα), which define the specific transition pathway and relative intensity of the emitted x-rays. Below is information outlining the sub-classifications.
- Kα = The combined Kα1, Kα2 is used for Z less than 40. The Kα1 only is used for the higher Z values.
- N = The data set for the N-series peaks is not completely characterized by standardized methods.
K-series relative peak intensities
18 ≤ Z < 59 | |
|---|---|
Kα | 100% |
Kβ | 10 – 20 |
At Z less than 18, the Kβ decreases in height, and becomes closer to, and is eventually not resolved from the Kα. At Z greater than 59, the Kβ increases in size and sub-peaks can be seen.
L-series relative peak intensities
| 21 ≤ Z ≤ 34 | 35 < Z | |
|---|---|---|
| Ll | 200 – 6% | 3.5 – 6% |
| Ln | 70 – 3% | 2 – 3% |
| Lα1 | 100% | 100% |
| Lβ1 | 20 – 34% | 35 – 52% |
| Lβ2 | 0% | 0 – 20% |
| Lγ1 | 0% | 0 – 8% |
| Lγ2 | 0% | 0 – 2% |
At Z less than 21, the Lα1 and Lβ1 are 0 and Ll is the dominant peak. The Ll is not observable at a Z of 14 or less.
M-series relative peak intensities
| 57 ≤ Z ≤ 70 | 70 < Z | |
|---|---|---|
| Mz | 140 – 13% | 6 – 4.5% |
| Mα | 100% | 100% |
| Mβ | 0 – 45% | 45 – 57% |
| Mγ | 20 – 3% | 3.5 – 1% |
| M2N4 | 0 – 2% | 0 – 2% |
At Z less than 57, the Mα becomes 0% and the Mz is the dominant peak. The Mγ becomes 0 at Z < 50.