Development of radioactive sources fixated in epoxy matrix to verify nuclear medicine equipments

The aim of the present work is to study and develop commercial resins for manufacturing solid sealed sources. The sources are produced with radionuclides of barium-133, cesium-137 and cobalt-57. They are used in radiation detectors verification. For the immobilization of the radionuclides in the epoxy matrix, it is made use of emulsifying agents that ensure the miscibility between resin and aqueous radioactive solution, as well as curing agents for controlling, curing and sealing the standard radioactive solution completely. As a result, it is expected to obtain standard water-equivalent sealed sources (the radioisotopes used in Nuclear Medicine are supplied in an aqueous form and the resin applied must have a very similar density comparing to the water). We used DGEBA epoxy matrix and DETA polyamic modified catalyst, and obtained great results. The epoxy resin cure can be improved in relation to the cure at room temperature, with use of irradiation, since it is used a dose around 37 kGy during curing. (authors)