Abstract: The disclosed mass spectrometer has, positioned between an input slit and an output slit, crossed by particles emitted by a sample, an optical coupling system placed between two respectively electrostatic and magnetic sectors. The optical coupling system comprises at least two lenses with slits oriented respectively along a first direction in which the path of the ions is incurvated by the electrostatic and magnetic sectors and along a direction perpendicular to the plane of the path. The position of the two lenses on the optical axis of the spectrometer is determined to obtain a compensation for the chromatic dispersions throughout the axis downline from the spectrometer, a stigmatic image of the input slit in the output plane of the spectrometer and a stigmatic image downline from the spectrometer.

Abstract: A time-of-flight method and apparatus of analysis comprising a first step of continuously scanning the surface of a solid sample to be analyzed with a primary particles beam to liberate secondary particles from the sample and to thereby ionize the secondary particles. A second step forms a secondary particles beam and makes it travel through a path which is long enough for secondary particles with different energy levels or different masses to have substantially different times of flight. Then, the secondary particles are discriminated by deflecting them at an angle which is variable periodically as a function of time, with the same period as that of the scanning by the primary particles beam, but with a fixed phase shift such that the secondary particles have a given time of flight and are deflected in a pre-determined direction, irrespective of the point on the sample from which these secondary particles have been liberated.

Abstract: Disclosed are a method for the analysis of a sample by sputtering, using a particle beam, and a device to implement this method. The method consists in:scanning the sample on a surface called a scanning surface, to hollow out a crater with a flat bed, said flat bed constituting a surface called a surface of analysis;ionizing the particles liberated from the surface of analysis, by means of a pulsed laser beamidentifying the nature of the liberated and ionized particles by means of a mass spectrometer. The idle time available between two pulses of the laser beam is used to sputter the flanks of the crater, for these flanks also have to be sputtered although they do not form part of the surface of analysis proper. Thus the time needed to sputter the sample up to a certain depth is reduced to the minimum without loss of information.