Improvements in or relating to mass-spectroscopy

摘要

1,030,421. Mass spectrometers. ATLAS MESSUND ANALYSENTECHNIK G.m.b.H. March 11, 1963 [March 10, 1962], No. 9593/63. Heading H1D. In mass-spectrometers of the type having photographic plates as detectors, the exposure times of the plates are graduated by a method wherein the number of ion current impulses reaching a plate is preselected and used for cutting off the ion current, and wherein the charge generated on the plate, or a charge proportional thereto, is measured during the exposure time. As shown, a mass-spectrometer comprises an ion source a, a deflecting system b, c, and a collector d having a slit g through which part of the ion beam A passes to impinge on a photographic plate f. The number of ion current impulses reaching the plate f is preselected by a device h which cuts off the impulse generator i for the ion source a when the selected number of current impulses is reached. During the exposure time, the charge generated on the plate is measured by capacitor k and device m.