1. Classifications. Areas of application of the various methods

Most of these methods use the optics of light or X-ray photons, electrons, ions or other particles. In all cases, the equipment includes :

• a source of radiation ;

• device(s) for focusing an intense probe on the sample surface (primary beam);

• detectors to detect the intensity of the emitted signal as a function of position, angle, energy, etc;

• a large electronic component for amplifying, processing, recording and displaying signals, often combined, these days, with a computer that can store and process data, perform complex corrections, and even control the entire system. The considerable progress made in recent years is largely due to this use of computers.

Wherever possible, we have also tried to add devices...