In nuclear fusion experiments, neutrons are created in the reactions between fuel hydrogen isotops; deuterium-tritium and deuterium-deuterium fusion reactions give respectively rise to neutrons of 14MeV and 2.5MeV kinetic energy. Neutron spectrometry represents thus a tool for obtaining important information on the fuel ion composition, velocity distribution and temperature of fusion plasmas. Moreover in a fusion reaction gamma-rays generated both in the plasma source and by interaction of the neutrons with the materials in the shielding and the environment, contaminate neutron fields. Since neutron spectrometry is possible only if neutron- and photon-induced events can be well identified then detectors with n-g discrimination capability are needed. Mechanisms for detecting neutrons in matter are based on indirect methods. The neutron can be scattered by a nucleus, transferring some of its kinetic energy. If the neutron energy reaches the keV range, enough energy is transferred in the elastic scattering and the recoiling nucleus ionizes the material surrounding the point of interaction. This mechanism is only efficient for neutrons interacting with light nuclei. In fact, only hydrogen and helium nuclei are light enough for practical detectors. Hydrogen-containing scintillators allow the detection of high energy neutrons using proton recoil and successful applications have been reported with organic scintillators for neutron energies >1MeV.