Fig. 3

Thermal neutron field characteristics measured with the radiochromic film (A). The use of this method allows for a quick and accurate sample alignment with the beam. Line profiles, when taken through the centre, demonstrate the slightly skewed nature of thermal neutron flux within the beam. In the X profile (B) the beam intensity can be seen to drop off slightly from left to right but remains linear until it falls away sharply at the edge. The Y profile (C) shows a flatter profile but with much more pronounced shoulders. The proposed region for irradiation is delimited by the blue lines.