Secondary emission mass spectrometer mechanism to be used with other

Abstract

There is disclosed a secondary ion mass spectrometer to be used with other spectro analysis mechanisms where the sample holder is fixed in a main vacuum chamber having a secondary vacuum chamber communicating with the main chamber with a vacuum seal between the two in which a substantially 90.degree. spherical segment energy analyzer is disposed in the second vacuum chamber along with a quadrupole mass spectrometer and electron multiplier. A primary ion gun is disposed within the main vacuum chamber directing an ion beam at the samples to be tested and the secondary ions emitted are collected through a longitudinal extraction lens mechanism disposed between the 90.degree. spherical segment energy analyzer and the sample to be tested in which the longitudinal extraction lens mechanism is connected to a linear movement device to focus and withdraw the extraction lens with respect to the sample to be tested and a plurality of blanking plates are disposed within the longitudinal extraction lens mechanism for deflecting certain of the secondary ions which are emitted from outside a selected area of the sample to be tested and the blanking plates are controlled through an electronic switching means that controls the blanking plates and the ion gun so that only secondary ions are emitted from the selected area of the samples being tested. The mechanism is moveable along lateral axes with respect to an axis extending through the longitudinal extraction lens and the sample to be tested.