Decay Kinetics of CeF3 under VUV and X-ray Synchrotron Radiation

Symmetry

Andrei Belsky¹  Irina Kamenskikh²  Evgeny Tishchenko²  Sergey Omelkov³  Marco Kirm³  Andrey Vasil’ev⁴ 

[1] CELIA, CNRS-CEA-University of Bordeaux, 33405 Talence, France;Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory 1(2), 119991 Moscow, Russia;Institute of Physics, University of Tartu, W. Ostwald str. 1, 50411 Tartu, Estonia;Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Leninskie Gory 1(2), 119991 Moscow, Russia;

关键词: CeF₃ crystals;    luminescence kinetics;    electronic excitations;    interaction of excitations;   

DOI  :  10.3390/sym12060914

来源: DOAJ

【 摘 要 】

Characteristic dimensions and evolution times of regions of secondary electronic excitations created by the interaction of ionizing radiation with matter cannot be measured directly. At the same time these are essential parameters both for engineering of nanostructured composite materials defining optimal layer thickness and nanoparticles radii and for the development of optimized scintillators. The paper demonstrates how such spatial and temporal data can be extracted from luminescence decay kinetics excited by vacuum ultraviolet (VUV) and X-ray photons at modern sources of synchrotron radiation MAX IV and PETRA III. Specific features of energy-band structure of self-activated crystal CeF₃ are discussed, and its potential for a super-fast detection of ionizing radiation evaluated. Diffusion-controlled dipole–dipole interaction of Frenkel excitons is demonstrated to account well for the luminescence non-exponential decay kinetics providing information on the scales of excited regions created by photons of different energy. For 20 eV photons the radius of excited regions is estimated to be 10 nm, and for 200 eV photons it increases to 18 nm. Effective radius of excited regions of complicated shape created by 19 keV is as large as 80 nm and the diffusion length of Frenkel excitons over radiative time is 14 nm.

【 授权许可】

Unknown