APPARATUS TO MEASURE THE IONIC CURRENT PRODUCED BY AN ION BEAM

摘要

The invention relates to an ion current measuring device. This device comprises a vacuum chamber, a diaphragm for introducing an ion beam into the chamber, means for collecting the ions from the diaphragm and located at the end of the chamber opposite to the diaphragm, and means for measuring a periodic voltage between the collecting means and the reference earth. It is characterized in that it also comprises means located between the diaphragm and the collecting means, for bringing about a periodic modulation of the intensity of the ion current circulating between the collecting means and a reference earth, the measuring means being current or frequency measuring means. Application to the measurement of ion currents, particularly in mass spectrometry.