DETERMINATION OF THE NEUTRON ANGULAR RESPONSE USING A SINGLE ETCHED TRACK DETECTOR

A method for the determination of the neutron angular response as a fu nction of incident angle is described using only one exposure of a sin gle bent plastic detector strip in a half cylindrical geometry. After etching, the detector surface is scanned along the centre line in para llel narrow fields. On the basis of the equation derived from the irra diation geometry the distance of each field can be correlated to the a ngle of neutron incidence alpha. Thus, the track density values corres pond to all angles from 0-degree to 90-degrees. The application of the least square fit method provides: (a) correction in case of an inaccu rate irradiation geometry, (b) the proper 'source-detector' distance c orrection of the neutron fluence, and (c) a method for estimating the angular response as a function of angle alpha of neutron incidence usi ng the simple empirical equation.p (alpha) = a + b x cos (2alpha + pi) .