Gd2O2S:Nd Fluorescent Ceramic for CT Detectors
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Solution Overview
Problem
Current fluorescent materials for CT and X-ray applications, such as Pr-doped Gd2O2S and Eu-doped (Y,Gd)2O3, lack alternatives with improved emitting characteristics and high light output, particularly suffering from significant afterglow issues.
Innovation Solution
Incorporation of Nd ions into Gd2O2S and (Y,Gd)2O3 materials as emitters, along with the use of hot-pressing and vacuum annealing processes, to produce a Gd2O2S:Nd fluorescent ceramic with enhanced light yield and reduced afterglow, utilizing Nd3+ concentrations between 100 to 1000 wt. ppm and grain sizes between 1 μm to 20 μm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional fluorescent materials (Pr-doped Gd2O2S, Eu-doped (Y,Gd)2O3) are used, then high light output is achieved, but significant afterglow occurs
Solution Approach 1:
The patent changes the emitter parameter from conventional Pr or Eu ions to Nd ions, which fundamentally alters the emission characteristics. Nd-doped materials exhibit minimal afterglow while maintaining high light output, directly resolving the contradiction between reducing energy loss and maintaining reliability.
2Manufacturing precision
If hot-pressing and vacuum annealing processes are used, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent applies hot-pressing and vacuum annealing as preliminary actions during material synthesis to achieve the desired ceramic density and Nd ion distribution before final detector assembly. This ensures high manufacturing precision is built into the material itself rather than requiring complex post-processing adjustments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The Gd2O2S:Nd fluorescent material exhibits a relative light yield greater than 120% of CdWO4, minimal afterglow, and improved transparency, making it suitable for high-performance CT and X-ray detectors.
Implementation Method 1
Fluorescent members for detecting high-energy radiation contain a phosphor that can absorb the radiation and convert it into visible light. The luminescent emission thereby generated is electronically acquired and evaluated with the assistance of light sensitive systems such as photodiodes or photomultipliers.
Implementation Method 2
The invention further relates to a method of manufacturing a fluorescent ceramic using single-axis hot pressing.
Data Source
AI summary
The invention relates to a Gd2O2S:Nd fluorescent material and the use of Nd3+ as emitter in suitable materials.