Absorbed dose

Dosimetry refers to the action of quantitatively measuring the dose absorbed by an organism or sample when exposed to ionizing radiation.

The absorbed dose corresponds to the quantity of energy absorbed per unit mass of the material exposed to ionizing radiation. It is a physical quantity.
To ensure the best traceability, ATRON uses Alanine dosimeters to measure the absorbed dose in the irradiated sample. These serve as the standard and are commonly used for routine measurements of absorbed doses from 10 Gy to 100 kGy.

Displacement per atom

Effects of irradiation on materials are generally expressed in number of displacements per atom (d.p.a.).

Irradiation of a material can lead to atomic displacements within the material itself. The projectile yields part of its energy to atoms of the medium during elastic shocks. The impacted atom (PKA) is then projected and strikes other atoms and so on.
The number of displacements per atom translates the number of transfers of each atom of the structure during its lifetime. These can generate point defects (gaps or interstitials) leading to aging, embrittlement or accelerated corrosion of the material.
The specifications for resistance to irradiation are expressed in fluences of damage "end-of-life", i.e. generally in d.p.a.

Measurement tools

In order to characterize the effects of irradiation on a material, ATRON provides electrical, magnetic or mechanical measurements.

The ATRON platform can provide a set of expertise and tools for characterization:

  • Transmission or scanning electron microscope, with high spatial resolution,
  • Tomographic atomic probe,
  • Optical spectrometry, X-ray spectrometry,
  • Ohmmeter, resistivity meter,
  • Force measuring instruments, dynamometer or other,
  • Piezoelectric measurements by interferometry or rheometer,
  • Hardness tester for indentation,
  • Etc.