Evaluation of the response of a "Long-Counter" for Am-241/Be neutrons

A "Long-Counter" neutron detector is being used in the context of the DREAB (Dosimetry of the Radiation in the Brazilian Airspace) project to monitor the integral flow of neutrons deriving from the interaction of cosmic radiation with the atmosphere, which is important for measuring radiation doses received by humans at ground level and is mainly responsible for doses received by aircraft crews and sensitive instrumentation. In this work the preliminary tests performed with the Long-Counter neutron detector are presented using a 241Am/Be neutron source where the radial and transversal directional dependence of the equipment was evaluated and also an additional backward-shield in the equipment was verified, as a way of minimizing the back nodule response in relation to the frontal nodule, which is a condition of interest for the current work in progress.