Ptychography Background Radiation Estimation

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Solution Overview

Problem

Existing image data generation methods, such as PIE and ePIE, are affected by inelastic scattering, which introduces incoherent background radiation that contaminates coherent diffraction patterns, leading to artefacts in probe and object function reconstructions.

Innovation Solution

A method and apparatus that estimate and separate the incoherent background radiation by creating an incoherent background map, allowing for the reduction of background radiation effects by masking and subtracting the background component from diffraction patterns, thereby improving the accuracy of probe and object function estimates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If incident radiation interacts with the target object, then coherent diffraction patterns are generated for imaging, but inelastic scattering introduces incoherent background radiation that contaminates the patterns

Engineering Contradiction:
Improvediffraction pattern qualityVSAvoidinelastic scattering background
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent segments the total detected signal into coherent and incoherent components by measuring the target object with and without a mask, then subtracting the masked signal (coherent only) from the unmasked signal to isolate and remove the incoherent background contribution

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the incoherent background radiation component from the total diffraction pattern by using mask-based measurements to identify and separate the background contribution, then removes it to recover the pure coherent diffraction signal

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If background radiation is not removed, then the complete scattering signal is recorded, but artefacts appear in probe and object function reconstructions

Engineering Contradiction:
Improvereconstruction accuracyVSAvoidbackground radiation artefacts
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements an iterative feedback process where the reconstructed probe and object functions are used to predict the coherent diffraction pattern, compare it with the measured signal, and update the reconstruction to progressively reduce background artefact contamination

Inventive Principle:
Principle #23Feedback

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 approach reduces the impact of inelastic scattering artefacts, resulting in more accurate image data generation by isolating the coherent signal and improving the fidelity of reconstructed probe and object functions.

Implementation Method 1

An intensity of radiation scattered by the target object is detected using at least one detector

Methodology Applied
Scientific EffectElastic scattering: Scattering

Implementation Method 2

a portion of the radiation interacts via inelastic scattering. At least some of the radiation having undergone inelastic scattering undergoes a change in wavelength

Methodology Applied
Scientific EffectInelastic scattering: Scattering

Implementation Method 3

Incident radiation is provided from a radiation source at the target object

Methodology Applied
Scientific EffectX-ray radiation: X-Ray

Data Source

PatentEP2890975B1Estimation of background radiation from ptychography
Publication Date: 2020.01.01 PHASE FOCUS
  • EP2890975B1 patent drawingFigure 1~2
  • EP2890975B1 patent drawingFigure 3~4
  • EP2890975B1 patent drawingFigure 5

AI summary

Embodiments of the present invention provide a method of estimating a magnitude of background radiation for each of a plurality of regions of a target object comprising providing an estimate of background radiation detected by a detector, measuring radiation scattered by the target object at the detector for each of a plurality of positions of the object with respect to the incident radiation, calculating, for each of the positions, an estimate of a wavefront at the detector, and determining, for each position, an estimated wavefront comprising a coherent contribution from radiation scattered by the target object and a background contribution, wherein said background contribution is at least partly incoherent with the radiation scattered by the target object. This method is particularly suitable for performing coherent diffractive imaging using ptychography where contribution from the incoherently scattered background is taken into account.