Ce-doped LuAG single-crystal fibers grown from the melt for high-energy physics

Abstract

Under a stationary stable regime undoped and Ce-doped LuAG (Lu 3 Al 5 O 12 ) single-crystal fibers were grown by a micro-pullingdown technique. The meniscus length corresponding to the equilibrium state was <200 lm. Fluctuations in the fiber composition and pulling rate were found to have a significant effect on the properties of the fibers grown. A great improvement in the performance was found in samples containing low Ce concentrations (60.1 at.%) and produced using pulling rates <0.5 mm min À1 . Under such conditions a good lateral surface fiber quality was obtained and light propagation was significantly improved. Conversely, a high Ce concentration and a high pulling rate resulted in a strong degradation of the fiber surface quality causing defects to appear and a decrease in light output.

Needs, Trends, and Advances in Inorganic Scintillators

“…In this frame, the garnet composition has been identified as the most promising material [156]. During the last few years, much progress has been made in the understanding and optimization of the growing process and the doping conditions to improve the radial segregation of the dopant, the attenuation length, and the radiation hardness [46], [157], [158] in YAG and LuAG fibers. Long fibers of more than 40-cm length can now be produced in a reproducible way with homogeneous quality in term of light yield and attenuation length (Fig.…”

Progress in fabrication of long transparent YAG:Ce and YAG:Ce,Mg single crystalline fibers for HEP applications

“…1c,d). Variation of fiber diameter can be related both to Ce segregation to the fiber periphery 5 and by Al deficiency in the melt, as well as by unstable thermal conditions of the crystallization. Microscopic observations also show the presence of gas bubbles in both LuAG:Ce and YAG:Ce fibers ( Fig.…”

“…Transparency degradation in some LuAG:Ce fibers was linked to scattering centers created on inclusions consisting of microscopic gas bubbles 5 . Inclusions are formed at deterioration of steady-state conditions of crystallization, namely variation of melt meniscus thickness and shape during µ-PD growth.…”

Calorimeter Designs Based on Fibre-Shaped Scintillators

“…Following a process of optimization of the crystal growth procedure in connection with the material elaboration, the average attenuation length of fibres grown with micro-pulling-down technique has been improved up to 60 cm (see Fig.4) and the reproducibility required for large mass production was demonstrated [19][20].…”