Written by: Iwan T. Mitchell
Published on:

DTHE (Dual Tomograph for High Energy) by RX Solutions

Overview

The Dual Tomograph for High Energy (DTHE) is a unique laboratory X-ray computed tomography system hosted at INSA Lyon and operated by the MateIS laboratory.

Photograph of DTHE

Unlike conventional XCT systems, DTHE consists of two independent high-energy tomography lines mounted at 90° around a shared rotation stage. This unusual configuration enables simultaneous imaging of the same specimen using different imaging parameters such as tube voltage, filtration, magnification, and exposure time.

Beam Characteristics

Property Value
Source type Microfocus X-ray tube
Beam geometry Cone beam
Target material Tungsten (W)
Target angle 12°
Tube voltage range 60–260 kV
Tube current range 50–500 μA

Scientific Applications

The DTHE system is particularly suited to research involving:

  • Materials science research
  • Industrial inspection
  • Additive manufacturing
  • Metals and alloys
  • Composite materials
  • High-density engineering materials
  • Multi-scale tomography
  • Multi-energy tomography
  • Beam-hardening studies
  • Imaging protocol optimisation

The dual-line design enables comparative acquisitions under different conditions, making DTHE particularly valuable for investigating the influence of imaging parameters on image quality, artefact formation, and reconstruction accuracy.

Twin Fidelity

Unlike a purely geometrical representation, the DTHE digital twin includes experimentally measured and calibrated parameters:

  • Calibrated tube flux model
  • Source filtration
  • Detector line spread function (LSF)
  • Detector gain model
  • Detector energy response
  • Mechanical positioning constraints
  • Variable tube voltage and current
  • Multiple detector acquisition modes

These models allow realistic simulation of image quality, blur, detector response, and acquisition statistics observed on the physical system.

X-ray Source

X-ray Tube

Property Value
Type Tungsten microfocus tube
Geometry Cone beam
Voltage range 60–260 kV
Current range 50–500 μA
Target material W
Target angle 12°

Inherent Filtration

Material Thickness
Aluminium 0.5 mm
Carbon 4 mm

Available External Filtration

Material Available Thicknesses
Copper 1, 2, 3, 4 mm
Molybdenum 0.2–1.0 mm
Silver 0.125–0.625 mm

Flux Model

The digital twin incorporates a calibrated flux model derived from experimental measurements. Flux is computed as a function of tube voltage and exposure conditions, enabling realistic noise simulation and acquisition planning.

Detector Model

The digital twin includes a detector model calibrated from experimental measurements.

Detector Characteristics

Property Value
Maximum resolution 2880 × 2880 pixels
Pixel pitch 150 μm
Scintillator Gd₂O₂S DRZ-Plus
Scintillator thickness 210 μm
Line spread function Measured and modelled
Dark-field noise Not modelled

Available Acquisition Modes

Resolution
2880 × 2880
1920 × 1920
1440 × 1440
1440 × 2880
1920 × 2880
960 × 2880
480 × 2880

Available Exposure Times

  • 0.067 s
  • 0.083 s
  • 0.111 s
  • 0.167 s
  • 0.333 s
  • 0.500 s

Detector Gain Model

The detector gain model reproduces the response of the detector electronics through experimentally calibrated gain parameters and ADU conversion factors.

This enables realistic simulation of detector dynamic range and exposure behaviour.

Simulated Effects

  • Detector blur (LSF)
  • Detector gain
  • Quantum noise
  • Scintillator response
  • Tube spectrum generation
  • Source filtration effects

Acquisition Geometry

Source Position

Parameter Value
Source-to-object distance 0–1000 mm

Detector Position

Parameter Value
Object-to-detector distance 0–1000 mm

The flexible acquisition geometry enables a wide range of magnifications.

Why This Twin Is Unique

The DTHE digital twin reproduces an unconventional dual-line laboratory tomography instrument in which two independent X-ray systems share a common rotation stage.

This architecture makes it possible to investigate acquisition strategies using different imaging conditions, including variations in energy, filtration, magnification, and exposure settings.

The twin incorporates experimentally characterised detector response, detector blur, source filtration, and acquisition constraints, providing a realistic environment for the development and evaluation of advanced XCT methodologies.

Its unique multi-line design makes it particularly attractive for research into:

  • Beam-hardening mitigation
  • Acquisition optimisation
  • Reconstruction benchmarking
  • Synthetic dataset generation
  • Machine-learning applications
  • Multi-energy imaging workflows

Affiliations