Core–valence luminescence in scintillators

The state of the art of core–valence luminescence (CVL) in a number of halides (BaF₂, CsCl, LiBaF₃, etc.) is analysed. The following items are discussed: common properties of CVL, a suppression of slow emission component in BaF₂, an effect of secondary excitation density on intensity and decay profile of the emission, a neutron–gamma discrimination, spectrum simulations, impurity-associated CVL, an origin of slow- and long-wavelength CVL components, a lattice relaxation, vibrations of lattice environment and phonon broadening of the emission bands.

Experimental results on impurity-associated CVL of Rb_1−xCs_xBr (x<0.2) are presented and discussed. It is shown that the impurity-associated luminescence gives us a convenient way for the improvement of light output and variation of the emission wavelength of the scintillators.