Abstract: The invention relates to a solid organic scintillator comprising a polymeric matrix in which there are dispersed one or more fluorophore compounds and one or more chemical elements having an atomic number ranging from 40 to 83, characterized in that said scintillator has a weight content of said chemical elements of at least 5% by weight relative to the total weight of the scintillator, and in that the scintillator emits an emission spectrum comprising an emission peak at a wavelength of at least 550 nm.

Abstract: The invention relates to the use of 1,8-naphthalimide derivatives and of their salts as scintillation agents and more specifically as agents for discriminating between fast neutrons and gamma rays. It also relates to liquid scintillators comprising these scintillation agents in solution in a solvent and to novel 1,8-naphthalimide derivates of use as scintillation agents, in particular for discriminating between fast neutrons and gamma rays. Applications: all the fields of use of scintillators and in particular industry, geophysics, fundamental physics, in particular nuclear physics, the safety of goods and people, protection from radiation of workers in the industrial, nuclear and medical sectors, medical imaging, and the like.