Bridgman-stockbarge method for preparing cerium-doped lanthanum bromide scintillating crystal

Abstract

The present invention relates to a bridgman-stockbarge method for preparing a cerium-doped lanthanum bromide scintillating crystal. According to the present invention, the modified bridgman-stockbarge method is adopted to prepare the scintillating crystal Cex:La(1-x)Br3; with the modified bridgman-stockbarge method, during the raw material melting stage, the upper temperature zone is divided into an upper temperature zone a and an upper temperature zone b through independent three temperature zone control, wherein the temperature of the upper temperature zone is higher than the melting point of the crystal, and the temperature of the upper temperature zone b is slightly higher than the temperature of the upper temperature zone a; during the spontaneous crystal nucleation stage, the embedded transparent quartz optical fiber is adopted to introduce helium neon laser, and the light loss change of the laser is observed to determine whether the single crystal of the spontaneously-nucleated seed crystal is formed after screening; after the crystal grows, the annealing treatment is performed for a long time under the reduction hydrogen atmosphere, the crystal thermal stress is eliminated, and the useless Ce<4+> in the crystal is subjected to valence variation to obtain the Ce<3+>.

Description

technical field [0001] The invention relates to the field of crystal raw material synthesis and crystal growth technology, in particular to an improved crucible descent method for preparing cerium-doped lanthanum bromide scintillation crystals. Background technique [0002] Scintillation crystals can be made into detectors, and have great application prospects in the fields of high-energy physics, nuclear physics, imaging nuclear medicine diagnosis (XCT, PET), geological exploration, astronomy and space physics, and safety inspection. With the rapid development of nuclear science and technology and other related technologies, its application fields are constantly expanding. Different application fields also put forward more and higher requirements for inorganic scintillators. Traditional scintillation crystals such as NaI(Tl) and BGO cannot meet the special requirements of new application fields. [0003] People are exploring new and excellent scintillation crystals suitab...

AI Technical Summary

Problems solved by technology

But LaBr3:Ce crystal growth is difficult, the components are seriously volatile, and it is very easy to react with oxygen and water; and the crystal is very easy to crack

Therefore, the yield of LaBr3:Ce crystals is very low, and it is particularly difficult to grow large-sized crystals, and the price is also extremely expensive.

Images