Table 1.
Critical absorption and emission energies for photoelectric absorption and x-ray fluorescence emission.
| |
|
Iodine (I) |
Gadolinium (Gd) |
Platinum (Pt) |
|---|---|---|---|---|
| Atomic number (Z) | 53 | 64 | 78 | |
| Critical absorption | Kab | 33.164 | 50.229 | 78.379 |
| energies (keV) | LIab | 5.190 | 8.393 | 13.873 |
| LIIab | 4.856 | 7.940 | 13.268 | |
| LIIIab | 4.559 | 7.252 | 11.559 | |
| Emission energies | Kβ2 | 33.016 | 49.961 | 77.866 |
| from x-ray | Kβ1 | 32.292 | 48.718 | 75.736 |
| fluorescence (keV)1 | Kα2 | 28.610 | 42.983 | 66.820 |
| Kα1 | 28.315 | 42.280 | 65.111 | |
| Lγ1 | 4.800 | 7.788 | 12.939 | |
| Lβ2 | 4.507 | 7.102 | 11.249 | |
| Lβ1 | 4.220 | 6.714 | 11.069 | |
| Lα2 | 3.937 | 6.059 | 9.441 | |
| Lα1 | 3.926 | 6.027 | 9.360 | |
| Peaks identified from | Kβ2 | 32.42 | 48.87 | …2 |
| XRF imaging (keV) | Kβ1 | |||
| Kα2 | 29.00 | 43.13 | 66.89 | |
| Kα1 | 65.59 |
1
The emission energies are based on transition relations: Kα1 = Kab − LabIII; Kα1 = Kab − LIIab; Kβ1 = Kab − MIIIab, etc.
2
The Kβ peak of Pt (77.87 and 75.74 keV) is only detectable in the high concentration of Pt and it is not clearly defined in the low concentration of Pt. Thus, it was not used for data processing to relate fluorescence output to Pt concentration within the phantom.