Sample analysis using secondary electron emission - formed after scanning with monokinetic primary electrons by monokintic primary electron beam

In the elementary and chemical analysis of a sample by spectral analysis of the energies of secondary electrons emitted by the sample when subjected to the action of a monokinetic beam of primary electrons concentrated on its surface, (a) the intensity of the beam of primary monokinetic electrons emitted by an electron gun is modulated in accordance with a sinusoidal law of frequency (b) the beam of secondary electrons of energy is collected and its intensity is detected (c) an electrical detection signal is generated proportional to the intensity of the beam of energy and the intensity of the component of frequency in this signal is measured, thus giving the number of secondary electrons corresp. to that energy and (d) the value of the collection energy is modified to scan a spectrum of energies between two limits and so that the spectrum of the intensity of secondary electronic emission from the sample is obtd. as a function of the energy. Method enables samples to be analysed with minimum degradation.