Description of two tomography systems developed at IPEN-CNEN/SP

In this work, two computed tomography systems were developed for industrial application. The first one was of the first generation, which use a 5.08 cm (2'') NaI(Tl) detector. The second was developed with a 40 cm bar of plastic scintillator detector using two phototubes in its extremities in order to be used as a sensitive position detector. In both systems a 60Co source was used to carry out the CT experiments. The data acquisition board, the mechanical control interface and the software were specially developed in our laboratory to be used in this project. The tomography systems were tested using a phantom placed between the detector and a collimated 60Co source. The source activity was of 12 MBq (325 μCi). The phantom used was the standard phantom designed and prepared by the University of Bergen (Norway). The phantom is composed of solid polypropylene with 400 mm diameter with two 50 mm diameter holes. The phantom was placed between the 60Co source and the detector collimated with 5 mm lead window and it was rotated 360 deg in stepwise angle of 6 degree. The holes of the phantom were filled with materials of different densities; such as air, lead and rape seed oil. (author)