Scintillator surface modification by glancing angle deposition of thin ZrO₂ films

Abstract

In this research, we evaluated the properties of ZrO2 films produced with the glancing angle deposition technique and evaluated its effect on the detector properties. With using ZrO2, we created films with a refraction index in the range of 1.3 to 2.0, and produced a four layer graded-index (GRIN) antireflection coating. A BGO scintillator sample with an applied GRIN coating demonstrated up to ∼ 53% light output enhancement in comparison with the reference ones. For LYSO scintillators, the observed magnitude of the effect was less, ∼ 11%. Thus, this method is a technologically applicable way to improve the characteristics of existing and projected detector systems.

Modeling of the synergistic anti-reflection effect in gradient refractive index films integrated with subwavelength structures for photothermal conversion

“…Quintic index distribution (QID) is reported to be close to the optimal distribution for graded-index anti-reflection coatings. 17,57,58 The quintic refractive index profile is defined as: 17 n = n min + (n max À n min )(10t 3 À 15t 4 + 6t 5 ), (0 r t r 1) (23) In this model, a three-step approximation method is employed to select three discrete refractive index values that follow the quintic index distribution. By minimizing the mean square error (MSE), the three-step approximation function can better match the quintic index profile.…”

“…Quintic index distribution (QID) is reported to be close to the optimal distribution for graded-index anti-reflection coatings. 17,57,58 The quintic refractive index profile is defined as: 17 n = n min + ( n max − n min )(10 t 3 − 15 t 4 + 6 t 5 ), (0 ≤ t ≤ 1)…”

“…13 Furthermore, the admittance recursion model is extended to the design of gradient refractive index transparent ceramics, thus developing a complete algorithm for the design of this anti-reflection system. Genetic algorithm (GA), 14 particle swarm algorithm (PSO), 15 simulated annealing algorithm (SA), 16 and the quintic index distribution method (QID) 17 are employed respectively to optimize the structures of GRITCs, followed by a comprehensive analysis and comparison of these methods. Moreover, the electric field distributions of the structures calculated by the finite difference time domain (FDTD) method are demonstrated.…”

Bright Innovations: Review of Next-Generation Advances in Scintillator Engineering

“…A monolayer of polystyrene nanospheres (d = 200−600 nm) 82 Electron Beam Evaporation 28 BGO (11 × 13 × 2 mm 3 ) Light output increased by 53% (without grease) and 29% with grease under γ-quanta excitation; crystals were covered with reflective paint. Vertical columnar structure of ZrO 2 with graded refractive index (n = 1.3 to 2.0) 83 29 BGO (20 × 20 × 1.5 mm 3 ) Light output increased by 15% under γ-quanta excitation, and reflective wrapping and no optical grease were used. Vertical columnar structure of TiO 2 with graded refractive index (n = 1.15−2.17) 69 (Figure 2J)…”