Manufacturing and testing of a Neutron Thermopile detector at Tehran research reactor's thermal column

Upon increasing needs and vast application of neutron detectors, especially in nuclear reactors and growing number of linear accelerators, design and manufacturing of neutron detectors is a serious demand. The aim of this project is building neutron detectors capable of compensating gamma and temperature response in a radiation media. A special thermocouple coated with Boron carbide at the junction is developed. In a neutron flux, the nuclear reaction between neutron and Boron carbide which produces alpha particles, induce a voltage across the junction which is proportional to neutron density. To eliminate the effect of gamma and temperature of the medium, a thermocouple coated with Aluminum used as a differentiation mode in the detector, because of close atomic number, density, conduction coefficient and heat coefficient of Boron carbide and Aluminum. Detector is placed into thermal column of TRR. The threshold of measured flux was found to be using indium foil.