Growth of ⁶Li-enriched LiCl/BaCl₂ eutectic as a novel neutron scintillator

Abstract

In this study, Eu:6LiCl/BaCl2 with a high Li concentration was developed as a novel thermal neutron scintillator. Eu ions were doped as activators for the BaCl2 phase, and Eu:6LiCl/BaCl2 eutectics were grown via the vertical Bridgman–Stockbarger method in quartz ampoules (inner diameter = 4 mm). The Eu:6LiCl/BaCl2 eutectic exhibited a lamellar eutectic structure and optical transparency. The 400-nm emission due to the Eu2+ 4f–5d transition was observed in the BaCl2 phase by a cathode luminescence measurement. The light yield under neutrons was estimated to be over 20,200 photons/MeV. A pulse shape discrimination study was also performed using gamma and alpha-rays. The Eu:6LiCl/BaCl2 eutectic scintillator showed good potential of pulse shape discrimination.

Fabrication and Characterization of K2CeCl5/6LiCl and CeCl3/SrCl2/6LiCl Eutectics for Thermal Neutron Detection

“…The sealed ampoule was heated using a Pt tube heater with a high-frequency coil and pulled down at a rate of 0.2 mm/min. In this study, rates applied in the previous literature [13][14][15] were selected in order to verify the potential of the eutectics as thermal neutron scintillators. The grown eutectics were cut and polished in the cross-section and growth direction using a wire saw in a dry room (humidity < 3%) to prevent deliquescence.…”

“…This eutectic scintillator allows for a higher concentration of 6 Li than conventional single-crystal scintillators, thereby increasing the sensitivity to thermal neutrons. Our group has developed eutectic scintillators for thermal neutron detection, such as Ce 3+activated bromide of CeBr 3 / 6 LiBr [13] and Eu 2+ -activated chlorides of Eu:BaCl 2 / 6 LiCl [14] and Eu: 6 Li 2 SrCl 4 / 6 LiCl [15]. Some of them have been reported to exceed the scintillator properties of conventional single-crystal scintillators in terms of 6 Li concentration and light yield.…”

Light Inorganic Scintillation Materials for Neutron and Charge Particle Detection

“…Analyzing the genesis of the development of the technology of inorganic scintillation materials, we can say that the awareness of the advantages of light inorganic compounds appeared more than 20 years ago [19][20][21]. A noticeable interest in them grew with the start of research on a wider set of the light materials for the purpose of creating scintillators for neutron detection [22][23][24][25]. The range of activating additives was expanded, and work was also carried out to combine several elements (Li, B, O) containing nuclei that effectively interact with neutrons [26,27].…”

Compositionally Disordered Crystalline Compounds for Next Generation of Radiation Detectors

“…Light ternary compounds containing lithium and alkaline earth metals have also been studied quite well as phosphors of different luminescence colors. For scintillators, over the past year attempts have been made to grow crystals of relatively heavy lithium-containing eutectics: the lithium-strontium and lithium-barium chlorides [ 169 , 170 ]. An LiCaAlF 6 scintillator doped with cerium [ 171 ] and divalent europium [ 172 ] is also known from non-oxide systems, but it has low scintillation yield: 9000–12,000 ph/neutron when doped with Eu 2+ .…”