The successful use of gamma radiography depends on the ability to provide sufficient radiation to penetrate the weld and produce an image of acceptable resolution and contrast on the processed radiographic film.

Isotopes with low gamma energies don’t give a good quality due to the inability to penetrate the object being imaged but well Se-75 which Gamma Spectrum is from 66 keV to 401 keV, with two lines of high intensity at 136 keV and 265 keV.

The resultant average energy of 217 keV is lower than the 353 keV for Ir-192. This means that the Se-75 give better image quality compare to Ir-192 due to less energy.

Double Capsule containing the isotope as pressed selenium powder. The capsules are tested to comply with Special Form Certification, also fully accredited by the IAEA.

Se-75 Capsule type