Technique for measuring direct current of charged particle beam

A method is described for measuring direct current of charged particle beam. The method is based on a pulse modulation of beam current and measuring the strength of the magnetic field induced. The purpose of the invention is the current measurement at any cross section of a beam, noise suppression and enhancement of the measurement accuracy. This is achieved by the following: the beam current is modulated by low frequency with periodically varied phase, the noise voltage, proportional to the measured magnetic field strength, and useful signal are separated. The voltage noise is detected in the time intervals between the current pulses and introduced as error signal via the feedback channel to the transmitter input. The constant component of the measured signal is separated and registered