Determination of the neutron angular respone using a single etched track detector

A method for the determination of the neutron angular response as a function of incident angle is described using only one exposure of a single bent plastic detector strip in a half cylindrical geometry. After etching, the detector surface is scanned along the centre line in parallel narrow fields. On the basis of the equation derived from the irradiation geometry the distance of each field can be correlated to the angle of neutron incidence α. Thus, the track density values correspond to all angles from 0o to 90o. The application of the least square fit method provides: (a) correction in case of an inaccurate irradiation geometry, (b) the proper 'source-detector' distance correction of the neutron fluence, and (c) a method for estimating the angular response as a function of angle α of neutron incidence using the simple empirical equation ρ (α) = a + b x cos (2α + π). (author)