Abstract: The invention concerns a device (10) for regulating the intensity of a beam extracted from a particle accelerator, such as a cyclotron, used for example for protontherapy, said particles being generated from an ion source. The invention is characterized in that it comprises at least: a comparator (90) determining a difference ? between a digital signal IR representing the intensity of the beam measured at the output of the accelerator and a setpoint value IC of the beam intensity: a Smith predictor (80) which determines on the basis of the difference ?, a correct value of the intensity of the beam IP; an inverted correspondence table (40) supplying, on the basis of the corrected value of the intensity of the beam IP, a setpoint value IA for supply arc current from the ion source (20).

Abstract: The invention concerns a device (10) for regulating the intensity of a beam extracted from a particle accelerator, such as a cyclotron, used for example for protontherapy, said particles being generated from an ion source. The invention is characterised in that it comprises at least: a comparator (90) determining a difference &egr; between a digital signal IR representing the intensity of the beam measured at the output of the accelerator and a setpoint value IC of the beam intensity: a Smith predictor (80) which determines on the basis of the difference &egr;, a corrected value of the intensity of the beam IP; an inverted correspondence table (40) supplying, on the basis of the corrected value of the intensity of the beam IP a setpoint value IA for supplying arc current from the ion source (20).