Determination of the Thermal Neutron Flux by Measuring Gamma Radiations with High and Low Resolution Detectors

Thermal neutron flux (Фth) of Americium-Beryllium (Am-Be) neutron source has been measured by adopting the foil activation method. The neutrons emitted from Am-Be source are used to activate the indium-115 (115In) foil. The gamma radiations emitted from the activated isomer 116m1In are measured with NaI(Tl) and HPGe detectors. The thermal neutron flux is measured by adopting the cadmium (Cd) foil difference technique in which the Cd foil placed in front of the source to prevent the thermal neutrons from entering into the indium foil. The neutron flux is determined by measuring the gamma radiation emitted from indium foil using a low and high energy resolution NaI(Tl) and HPGe detectors respectively. The measured thermal neutron flux obtained from both detectors has been compared and found that the Фth does not depend on the resolution and type of the detectors used in the present investigations.