PROCESS AND APPARATUS FOR THE ELEMENTARY AND CHEMICAL ANALYSIS OF A SAMPLE BY SPECTRUM ANALYSIS OF THE ENERGY OF THE SECONDARY ELECTRONS

摘要

ABSTRACT OF THE DISCLOSUREA process of elementary and chemical analysis ofsamples by spectrum analysis of secondary electrons emittedby the sample when this is subjected to a beam of monoenergeticprimary electrons concentrated on its surface, the processconforming with the spectral, geometric and temporal needsand characteristics previously set forth, consists in thefollowing steps: the intensity of a beam of monoenergeticprimary electrons Ep emitted by an electron gun is modulatedaccording to a sinusoidal law at a frequency .omega.; the secondaryelectrons of energy E emitted by the sample are collected;the intensity of the collected beam is detected by generatingan electric detection signal proportional to the said intensity;the intensity of the electrons beam modulated at the frequency.omega. of the detection signal, which provides the number ofsecondary electrons corresponding to the energy, is measured,and, the value of the collection energy E is modified in orderto scan the energy spectrum comprised between the values E1and E2 50 that one obtains the spectrum n(E) of the intensityof the secondary electron emission of the sample as a functionof the energy E.