A dual neutron and gamma detection system has been developed for online measurements. The system consists of a single crystal mounted on a photomultiplier tube to detect simultaneously gamma radiation as well as thermal neutrons. A compact data acquisition system has been used for neutron and gamma discrimination. The system has been tested with different gamma energies and with an Am-Be neutron source at the University of Ontario Institute of Technology neutron facility. This thesis presents the characteristics of the developed detector, and experimental data carried out in different experiments in different fields. / UOIT