Energy Dispersive X-Ray Spectrometer Calibration Using Diffraction Geometry

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Solution Overview

Problem

Existing calibration methods for energy-dispersive X-ray spectrometry, particularly those using polynomial approximations, suffer from reduced precision outside the energy range between peaks, leading to inaccurate energy axis calibration across the entire detectable range.

Innovation Solution

A calibration method that determines the energy of signals detected in each detection region based on the positional relationships between the specimen, spectroscopic element, and detector, using a logical expression to convert positional data into energy values, ensuring precise energy determination across the entire detectable range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If polynomial approximation is used to correct the energy axis, then the energy range between peaks can be corrected comparatively precisely, but the precision deteriorates dramatically outside the energy range between the peaks used in the correction

Engineering Contradiction:
Improveenergy axis calibration precisionVSAvoidenergy range coverage
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the calibration approach from using polynomial approximation parameters to using a diffraction grating equation-based parameter system. By determining energy values through the diffraction grating equation involving grating constant, incident angle, and diffraction angle, the system achieves accurate calibration across the entire detectable energy range without the precision deterioration that occurs with polynomial approximation outside the peak range.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If polynomial approximation is used for energy axis correction, then calibration can be performed using peak positions, but accuracy is reduced outside the correction range

Engineering Contradiction:
Improvecalibration process simplicityVSAvoidenergy value accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces the mathematical approximation system (polynomial fitting) with a physical principle-based system (diffraction grating equation). This substitution allows the system to calculate energy values directly from the diffraction geometry and grating parameters, achieving high accuracy across the full energy range without relying on empirical peak position fitting that is limited to specific ranges.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This method provides precise energy axis calibration over the entire range of energy values, improving accuracy compared to polynomial approximation methods by directly utilizing positional relationships to determine energy values in each detection region.

Implementation Method 1

a diffraction grating that diffracts the signal

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

arranged in an energy dispersion direction

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 3

a detector that detects the signal diffracted by the spectroscopic element

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3671191B1Calibration method executed in an analysis device
Publication Date: 2023.07.12 JEOL LTD
  • EP3671191B1 patent drawingFigure 1
  • EP3671191B1 patent drawingFigure 2~3
  • EP3671191B1 patent drawingFigure 4~5

AI summary

A calibration method is executed in an analysis device (100) including a spectroscopic element (30) for diffracting a signal generated from a specimen (S) by irradiating the specimen with a primary beam, and a detector (40) that detects the signal diffracted by the spectroscopic element (30), the detector (40) having a plurality of detection regions (2) arranged in an energy dispersion direction (B), and the detector (40) detecting the signal to acquire a spectrum of the signal. The calibration method includes determining energy of the signal detected in each of the plurality of detection regions (2) based on a positional relationship between the specimen (S) and the spectroscopic element (30) and a positional relationship between the spectroscopic element (30) and each of the plurality of detection regions (2).