TRANSPARENT CERAMIC SCINTILLATION DETECTOR WITH GARNET STRUCTURE FOR POSITRON EMISSION TOMOGRAPHY Russian patent published in 2021 - IPC C09K11/78 C09K11/80 C04B35/01 C04B35/50 C04B35/626 G01T1/20 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry; it can be used when manufacturing scintillators for detecting radiation in systems of computer tomography (CT), positron emission tomography (PET), single-photon emission computer tomography (SPET). First of all, powder is formed by flame-aerosol pyrolysis of liquid precursors; synthesis in the combustion process; processing to obtain particles with a size of less than 500 mcm, for example, by grinding; deposition of particles from liquid solutions by changing pH or by synthesis based on ash-gel technology. The specified powder contains a composition with the formula: (Gd_3-a-cY_a)_x(Ga_5-bAl_b)_yO₁₂D_c, where D is alloying additive selected from Са²⁺, Се³⁺, Се⁴⁺, Mg²⁺, Nb⁵⁺, Pr³⁺, Sn²⁺, Sr²⁺, Ta⁵⁺, Tl⁺, Zr⁴⁺ and combinations thereof; a is from 0.5 to about 1.5; b is from 2.5 to 2.8; x and y is from 2.97 to 3.03; c is from 0.003 to 0.3. The obtained powder is combined to form optically transparent ceramics, using temperature, surrounding atmosphere or pressure to reduce defects in ceramics, which are connected to oxygen and/or thermodynamically reversible. In particular, the powder can be sintered in oxygen-containing atmosphere at 1200-1700°C, for example on air; or it can be pressed into a billet with following calcination firing at 500-1500°C. Се⁴⁺ content in optically transparent ceramics is from 0 to 50%. The obtained optically transparent ceramics is annealed in oxygen-containing atmosphere at 1000-1900°C. Optically transparent ceramics is characterized by rise time of less than or equal to 2 ns and/or temporal resolution of less than or equal to about 350 ps. The system for detecting radiation contains an optically transparent scintillator obtained from the specified ceramics that has polycrystalline structure, as well as a photo detector containing photo multiplier, for example silicon, for detecting light pulses from the optically transparent ceramic scintillator.

EFFECT: invention allows for an increase in ceramics transparency due to reduction in the specified defects in it and absence of residual porosity.

26 cl, 5 dwg, 2 tbl