New radiographic images from old neutron converter screens

This report summarizes the activities under the IAEA Coordinated Research Project (CRP) on 'Development of Improved Sources and Imaging Systems for Neutron Radiography'. Firstly a brief historical regarding the development of the Neutron Radiography - NR technique in IPEN with emphasis to the ideas to obtain new images from old neutron converter screens is provided. The NR working group of IPEN began to develop these ideas in 2000 using the available infrastructure. Because of the good preliminary results a CRP has been proposed to the IAEA. During this period of development several modifications, improvements and optimizations have been carried out in the NR facility as well as in the digital system to capture and process radiography images. As consequence most of the previous radiography data were improved resulting in the implementation of a new radiography technique the 'neutron induced electron and alpha radiography' having as most important feature the possibility to inspect low-thickness samples (∼ μm). Other important consequences of this CRP for our working group were the improvement of the track-etch neutron radiography sensitivity, the possibility to inspect radioactive samples in an almost real-time mode and as a future plan, the development of new researches such as the neutron induced proton radiography. (author)