Luminescence of LaBr3:Ce,Hf scintillation crystals under UV-VUV and X-ray excitation

The present study was carried out by means of the low temperature time-resolved luminescence UV–VUV spectroscopy as well as the optical and thermally activation spectroscopy. The Ce3+ centers in regular lattice sites and located in the vicinity of the point defects of crystal structure were observed. Spectral and kinetic characteristics of the luminescence of these centers were defined. A photoluminescence of new point defects of the crystal structure are also manifested. We evaluated the energy of the interband transitions as Eg ≈ 6.2 eV in LaBr3. At the excitation energies Eexc>13 eV (higher than 2Eg) the effect of the electronic excitations multiplication was detected

Luminescence of LaBr3LaBr_3 :Ce,Hf scintillation crystals under UV-VUV and X-ray excitation

The present study was carried out by means of the low temperature time-resolved luminescence UV–VUV spectroscopy as well as the optical and thermally activation spectroscopy. The Ce3+ centers in regular lattice sites and located in the vicinity of the point defects of crystal structure were observed. Spectral and kinetic characteristics of the luminescence of these centers were defined. A photoluminescence of new point defects of the crystal structure are also manifested. We evaluated the energy of the interband transitions as Eg ≈ 6.2 eV in LaBr3. At the excitation energies Eexc>13 eV (higher than 2Eg) the effect of the electronic excitations multiplication was detected

Artistic output as intersubjective third

Time-resolved X-ray-induced photoluminescence (PL) of LaBr 3:Ce scintillation spectrometer crystals excited by synchrotron radiation with photon energies within 45-290 eV has been studied at 7. 5 and 295 K. It is established that the PL response is essentially nonproportional to the exciting photon energy in the regions of photoionization of the Br 3d and La 4d levels and especially in the vicinity of the giant resonance. The PL decay kinetics in the spectral region corresponding to the d → f luminescence of Ce 3+ ions is nonexponential. The decay time is smaller than 15 ns and depends on the exciting photon energy and radiation wavelength. The influence of the products of interaction of these hygroscopic crystals with atmosphere on the spectral and kinetic characteristics of X-ray-induced PL has been determined. © 2012 Pleiades Publishing, Ltd

Time-Resolved Luminescence of LaBr3\mathrm{LaBr_3}-Ce Scintillation Crystals Upon Selective UV-VUV-XUV Excitation

The time-resolved photoluminescence (PL) of LaBr3-Ce scintillation spectrometric crystals produced in Russia is measured upon excitation using synchrotron radiation with photon energies of 3.7-21 and 45-290 eV at temperatures of 295 and 7.5 K. The PL spectra and decay curves are measured for excitation in the transparency range, at the edge of fundamental absorption, at the interband transitions, and in the range of inner-shell absorption. It is demonstrated that the PL yield is not proportional to the excitation energy, and that the PL decay curves are modified in the range of photoionization of the 3d (Br) and 4d (La) inner shells and, especially, in the range of giant resonance. © 2013 Allerton Press, Inc