We want to deepen the content of the topic segmentation with a few examples.
The following examples show the results of segmented gamma scan measurements for 200 L barrels. The measurements were carried out in the so-called multi-disc scan mode (often referred to as multi-rotation scan), as described on the previous page.
The examples begin with the display of each measured overall spectrum. This is created by summing the spectra measured at each individual position.
After starting the animation, the corresponding spatial distributions are shown for various characteristic lines in the overall spectrum. For this purpose, the respective characteristic line is first highlighted in red in the overall spectrum, with the abbreviation of the radionuclide name also shown in red, followed by its mass number and the energy of the line indicated below. Subsequently, the associated spatial distribution is shown.
You can pause, fast forward, or rewind the videos at any time after you start them.
1st Example:
From the spatial distributions of the various radionuclides, four insights can be derived:
- The spatial distributions of the two Co-60 lines are at the same positions; this must be the case since both characteristic lines come from the same radionuclide.
- The spatial distributions of Co-60, Cs-137, and Pa-233 are similar to each other, meaning they show approximately the same distributions. This indicates that the three radionuclides are likely present in a homogeneous mixture.
- Am-241 is located at a completely different position in the barrel. It is a point-like or small-volume source.
You can see that already from the observation of the spatial distributions, many pieces of information about the radionuclides contained in the examined container can be gained. This information is extremely useful when it comes to quantifying the radionuclides, i.e., determining their activities.
2nd Example
From the spatial distributions of the various radionuclides, several insights can be derived:
- The spatial distributions of the two Co-60 lines are at the same positions; this must be the case since both characteristic lines come from the same radionuclide.
- The spatial distributions for Co-60 show a large-volume, spatially limited distribution; this could indicate a container located in the 200 L barrel at approximately 40 cm height that contains Co-60.
- The spatial distributions of Co-60, Cs-137, and Eu-152 are similar to each other, meaning they show approximately the same distributions. This indicates that the three radionuclides are likely present in a homogeneous mixture.
- Pa-233 appears as a small-volume distribution at approximately 65 cm height.
- The spatial distribution for Am-241 shows several locally limited distributions at different height and angle positions.
You can see that already from the observation of the spatial distributions, many pieces of information about the radionuclides contained in the examined container can be gained. This information is extremely useful when it comes to quantifying the radionuclides, i.e., determining their activities.
Note:
If you have examined the spectrum more closely, you may have noticed that we have not identified all the lines contained in the spectrum and created their corresponding spatial distributions. The lines that were not considered are, for example, lines that also originate from Pa-233 (remember: A radionuclide can emit multiple characteristic lines at different energies). Other lines do not originate from the container itself but from the surroundings of the measurement site (e.g., natural radiation). Or they are characteristic X-ray lines.
