Natural and enriched Iridium-192 sources are constructed using iridium metal discs or pellets of uniform size in a welded stainless-steel capsule.
Selenium-75 sources are available in cylindrical and quasi-spherical focals, permitting shorter SFDs and greater sensitivity on fixed geometries.
Cobalt-60 sources are constructed using compres sion fused cobalt metal pellets confined within welded titanium and stainless steel capsules.
Ytterbium-169 sources are available in spherical and right circular cylinder focals, housed in a welded titanium alloy capsule.