A device for monitoring beams of relativistic nuclei is described. The
monitor's radiator is a square matrix consisting of 121 scintillating
sticks. The light from a scintillating stick is detected by two XP 20
20 photomultiplier tubes. The applications of the device, which depend
s on the beam width and the required accuracy of beam-intensity measur
ement, are discussed in detail. The maximum intensity measured by the
monitor amounts to 5.10(8) particle/discharge.