Probe dia. variation device for electron beam analysis - uses two beam deflectors and has fixed multi-aperture plate

The appts. works in conjunction with an X-ray analyser using the bombardment of electrons on a sample, and is connected to an electronic probe in order to vary the aperture of the electronic beam, for example to change from functioning as a scanning electron microscope to functioning as an X-ray microprobe. The device contains an electronic beam source, set of lenses and plate with holes to vary the electronic beam aperture. In this device however the plate is fixed in relation to the optical axis of the system. The device contains two beam deflectors, the first before the plate to permit the beam to pass through one hole of the plate and the second after the plate to return the beam to the optical axis of the system. LE DISPOSITIF COMPORTE UNE PLAQUE 5 PERCEE D'ORIFICES 6 POUR FAIRE VARIER L'OUVERTURE DU FAISCEAU ELECTRONIQUE, CETTE PLAQUE ETANT IMMOBILISEE PAR RAPPORT A L'AXE OPTIQUE DU SYSTEME D'OPTIQUE ELECTRONIQUE, ET DEUX ENSEMBLES DE DEVIATION 7 ET 8 MONTES DE PART ET D'AUTRE DE LA PLAQUE 5, DE SORTE QUE LE PREMIER ENSEMBLE DE DEVIATION 7 PERMET LE PASSAGE DU FAISCEAU ELECTRONIQUE 15 A TRAVERS L'UN DES ORIFICES 6 DE LA PLAQUE 5 ET LE DEUXIEME ENSEMBLE DE DEVIATION 8 ASSURE LE RETOUR DU FAISCEAU 15 SUR L'AXE OPTIQUE DU SYSTEME D'OPTIQUE ELECTRONIQUE.