H3D performance at the Nuclear Industry Proficiency Test Exercise (2019)

The H3D H420 was used at the Nuclear Industry Proficiency Test Exercise in 2019 to test its performance compared to other imaging spectrometers, mainly HPGe. As part of the exercise, a source package of unknown activity was placed in a waste drum in an unknown orientation. Detectors were to assess the waste drum and locate the source package as well as identify the isotopes and quantify their respective activities.

The source package contained Cs-137, Co-60, and Am-241, and was placed in the top of the waste drum, as shown in the following diagram.


The H420 was used to detect and create images of the waste drum. As shown below, the H420 was able to accurately locate the source package, and correctly identify all three isotopes present.

While imaging helps identify the source location, it does not affect the quantitative analysis done to identify source activity. Therefore the same results could be achieved with other H3D technology!

In this exercise, 36 different detectors were tested. 35 of the detectors were HPGe, with H3D representing the only non-HPGe detector at the exercise. Each detector quantified the amount of Cs-137, Co-60, and Am-241 in the source package. The following plots show the comparison between the HPGe results (blue dots), H3D CZT results (green triangle), and the actually activity value (red dotted line).

As shown in each comparison, H3D CZT results agree with the known activity value within one standard deviation for each of the isotopes. This exercise proved that H3D CZT performs on track or even better than competing HPGe detectors for quantifying unknown activities.

If you have any questions about this exercise or H3D performance, feel free to reply to this post!