Measurement of the electric current profile of particle clusters in gases and in a vacuum

摘要

The invention relates to the measurement of current profiles of free-flying ion or electron clusters which impinge on a detector electrode of a Faraday detector. The detector electrode here consists of a large number of structural elements in a bipolar arrangement, where neighboring structural elements have opposite polarities and structural elements with the same polarity are electrically connected, and a voltage is applied between neighboring structural elements so that before ions or electrons impinge on the detection electrode, they are essentially deflected onto the structural elements with one of the two polarities. If the current profiles on the structural elements of the two polarities are measured separately and subtracted from each other, a current profile which corresponds to the pure ion or electron current profile is obtained without using a screen grid.