Abstract: An essentially linear ion beam is derived from an ion emitting sample, inding a high-frequency mass filter of essentially linear ion beam path, the ion beam path extending towards an ion-electron converter of general rotation symmetrical shape with respect to an axis, the ion-electron converter having an axis aligned with the essentially linear ion beam path and including an electrode which has an aperture traversed by the beam from the source after having passed through the filter, the electrode having a secondary electron-emissive surface on a side thereof which is averted from the ion source and formed as a smoothly curved concave surface defining a converter chamber, the ions which have passed through the aperture being reflected back unto the secondary electron-emissive surface to then being detected by an electrode positioned within the converter chamber.
Type:
Grant
Filed:
March 15, 1978
Date of Patent:
September 16, 1980
Assignee:
Max-Planck-Gesellschaft zur Foerderung der Wissenschafter e.V.
Inventors:
Wolfgang O. Hofer, Jurgen Kirschner, Franz Thum