ELECTRON PROBE (EPMA)
An electron microprobe, also defined as an electron probe micro analyzer or electron microprobe analyzer, is a kind of measuring instruments which used to detect the chemical structure of relatively small quantities of bulk objects in a non-destructive manner. EPMA is a technology for obtaining specific and reliable quantitative chemical tests of our specimens’ micron size ranges.
Working principle:
EPMA operates by hitting a sample in micro-volume with a concentrated electron beam (average energy = 5-30 keV) and gathering the X-ray photons produced by different chemical components. An electron microprobe works on the assumption that when a solid substance is probed with an amplified and targeted beam of electrons, the incoming electron beam has enough energy to release both energy and matter from the specimen.
Characteristics:
EPMA equipment have a complete collection of developed microscope tools that enable continuous X-ray, SEM, and BSE imaging, as well as advanced light source microscopes; they offer extremely versatile sample screening with image magnification ranging from 40 to 400,000.
Uses:
- To determine which elements make up a material, irradiate it using electron beams and measure the distinctive X-ray that is produced.
- In certain situations, a mineral’s U-Th age, such as monazite, may be determined without testing isotopic ratios.
- EPMA is also often used to examine synthetic materials such as optical wafers, thin films, microcircuits, semi-conductors, and superconducting ceramics.
- The most often used approach for the chemical examination of geological materials at small scales is quantitative EPMA analysis.
SAMPLES:
Electron Probe Micro-Analyzer Fundamental Principles (EPMA) An electron microprobe begins with the idea that when a solid substance is attacked with an amplified and concentrated electron beam, the incoming beam of electrons has enough energy to release both energy and matter from specimen.
LIMITATIONS:
- Some elements produce x-rays with overlap peak regions (both in terms of power and wavelength) that must be separated.
- The electron probe is incapable of detecting the lightest elements (H, He, and Li).
- Probe analysis is also unable of distinguishing between the various valences states of Fe.
