THE ELECTRON MICROPROBE


	THE ELECTRON MICROPROBE

Electron microprobe laboratory,
Instructions for use,
Application fields.

Contact

A CNRS engineer is in charge of the electron microprobe. He takes in consideration every request, defining and preparing the samples, and carrying out the corresponding analyses.

For any information, please contact :
Marcel BOHN, Electron microprobe laboratory
IFREMER Brest
BP 70
29280 PLOUZANE cedex
Phone : (33) 2 98 22 42 56
Fax : (33) 2 98 22 45 70
Electronic mail : bohn@ifremer.fr

Electron microprobe laboratory

The electron microprobe laboratory consists in very high-performance equipments making it possible to qualitatively and quantitatively identify at the micron cubic scale some chemical elements which are present in various materials : rocks, metallic alloys, powders, etc.

Since 1951 when it was designed by Professor CASTAING, around one hundred electron microprobes have been built and sold throughout the world by the French company CAMECA.

The electron microprobe and its peripheral equipments located in the Marine Geosciences Department of IFREMER (Brest) make available in the West of France, a unique mode of analysis.

It belongs to IFREMER, Rennes and Nantes Universities, UBO (Université de Bretagne Occidentale), INSA Rennes, "Région Bretagne and Pays de Loire", which you can get in touch with if necessary.

Way of functioning

A beam of highly accelerated electrons hits a small surface (a square micron) of the analysed sample. The emerging radiation is analysed in a spectrometer in order to identify the various characteristic radiations which compose it and to know the elements present in the small volume concerned (1 micron cube). It is thus possible to quantify these information by comparing the X rays intensities characteristic of each element present in the sample, with the intensity of the same radiations emitted by a reference model.

The analysis and its processing are piloted by a computer.

The results of the analysis are visualized, memorized and recorded on video screens, printers, plotters, polaroïds, and so on.

1) Electron gun

2) Adjustable anode to wehnelt distance

3) Versatile three lens electron optical column

4) Spectrometer

5) Minicoil probe forming lens

6) High precision mechanical stage

7) Coaxial high resolution light optical microscope

8) SEM scanning coils

9) Introduction airlock for specimens

10) High pumping speed

The application fields

Observation, characterisation of specimens by scanning microscopy.

Qualitative and quantitative analyses on all mineral, vegetal, animal, synthetic, composite materials...

Determination of anomalies, studies of behaviour, modification or transformation of materials (fatigue, erosion, breaking, mixing, penetration of impurities, interdiffusion).

Examples of achievements

Mineralogical analyses :

Mineralogical study in rocks ;

Detection of precious metals in rocks (Au, Pt, Ag,...) ;

Comparison study between synthetic and natural crystals in gemmology ;

Mineralogical study of precious stones.

Metallurgical analyses :

Study of conformity on the composition of founder's steel.

Study of an alloy present in prosthondontics.

Study on the behaviour of a weld in metallurgy.

Analyses on thin layers :

Study of a conductive or insulating deposit on an electronic substrate in electronics.

Study of an anticorrosive covering for cars.

Various applications in various fields can be considered. The Electron Microprobe laboratory can work for any organism or company, whether it is public or private (estimate on request). The work is carried out in confidentiality conditions as specified by the customer.