Sentinel Se-75 sources for industrial radiography are formed as a metallic selenide, in a method that has been developed and patented by QSA. This gives QSA-Sentinel sources a unique and high degree of thermal safety and material stability properties, which the native form of Se-75 does not possess. Some of the advantages of the Sentinel sources are:
The active focal of the sources are octagon shaped in the range of 1.4 mm to 3.5 mm (maximum focal) to maximize the output in all directions of use while minimizing the focal spot size.
Sources are available in cylindrical and quasi-spherical focals. Compared to a right circular cylinder focal, the unique focal (quasi-spherical) of the Se-75 permits shorter SFDs and greater sensitivity on fixed geometries.
Testing of the metallic selenide sources demonstrates a high degree of thermal safety and material stability.
|Pellet Diameter||Maximum Focal Sizes||Nominal Activities|
|1 mm*||1.4 mm*||4Ci (148 GBq)|
|1.4 mm*||1.9 mm*||8Ci (296 GBq)|
|2 mm||2.2 mm||20Ci (740 GBq)|
|2.5 mm||2.7 mm||40 Ci (1.48 TBq)|
|2.85 mm||3.1 mm||60 Ci (2.22 TBq)|
|3.25 mm||3.5 mm||80 Ci (3.00 TBq)|
*Right circular cylinder focal