FIELD: beam collimators. SUBSTANCE: collimator has absorbing body formed by bushing 2, set of cylindrical absorbing members 3-6 joined over generating lines, and absorbing material 7 that fills up clearances between bushing 2 and members 3-6. Collimating aperture that has its cross-sectional area with two relatively perpendicular center lines X-X and Y-Y of different size along each axis and in direction perpendicular to it is formed by one or more gaps 8 between members 3-6. Bushing 2 may function as rotor of single-phase squirrel- cage motor. Members 3-6 have polished surfaces. EFFECT: reduced convergence of output beam due to specific geometry of collimator and additional collimation under effect of full external reflection. 4 cl, 3 dwg
