Laser and Electric Arc Synthesis of Nanocrystalline Scintillators

Two new methods of preparation of nanocrystalline scintillators are described. Laser ablation of microscopic powders immersed in optically transparent liquid was used to produce spherical nanoparticles, which preserved the initial compositions. Electric arc discharge between electrodes of definite metals immersed in water solutions of different salts produces a vast variety of scintillating compounds with nanoscopic dimensions and morphologies having crystallographic symmetry of the corresponding equilibrium phases. A wide range of different compositions and structures of tungsten oxides are obtained during one synthesis process, which is due to variety of temperatures and other conditions around the arc channel. It was found that the light emission spectroscopy of the discharge is a rather informative method of diagnostics of the process of the nanoparticle synthesis inside the discharge chamber. The synthesis of nanoscintillators by arc discharge turned out to be rather efficient and capable to create nanocrystalline scintillators of easily regulated compositions. Hydrogen injection into nanoparticles of tungsten oxide is detected by light emission and infrared absorption spectroscopy. Hydrogenated nanoscintillators obtained by this method are interesting for registration of fast neutrons.