1. Sample preparation and operating conditions

Although it is possible to analyze samples with a certain degree of relief, this is strongly discouraged, as is any chemical attack. Indeed, to avoid any abnormal absorption of the X-ray spectrum from the sample, the latter must be perfectly flat and polished.

Acceleration voltage should be chosen according to the relative ionization energy of the lines being analyzed (in general, two to three times the ionization energy is recommended). In wavelength-dispersive spectrometry (WDS), it can be adapted for each X-ray or at least for each energy range: 5 to 10 kV for low-energy radiation, up to 20 to 30 kV for the most energetic radiation. In energy selection spectrometry (EDS), the single voltage must be chosen according to the total energy range analyzed, usually 10 or 20 kV.

The electron beam intensity must be sufficiently high to ensure...