Exploration of new monitoring procedures
Some alpha-emitters, such as Th-228, Th-232 and U-238 have gamma-emitting daughters which can be detected in whole- or partial-body-counters (see Table below).
IDEAplus provides the retention functions for such daughter nuclides related to the intake of the respective mother nuclide. The figure to the left shows as example the whole body and lung retention of Pb-212 after inhalation of Th-228 (type S, 5 µm AMAD). The whole-body retention function shows a typical double peak pattern with the first peak being due to the activity in the extra-thoracic air pathways and the second peak due to the activity in the lungs.
|
Radionuclide |
Principal gamma-emission of daughter |
Typical lower LLD for lung counting, Bq |
||
|
Mother |
Daugther |
Energy, keV |
Abundancy, % |
|
|
Th-228 |
Pb-212 |
238,6 |
44,6 |
5 |
|
Th-232 |
Ac-228 |
911,1 |
29 |
5 |
|
U-238 |
Th-234 |
63,3 + 92,4 + 92,8 |
9,2 |
10 |