FIELD: physics.
SUBSTANCE: method involves using a guide structure, having a channel for conveying particles of the initial beam, having a straight longitudinal axis and a wall made from material which is capable of electrostatic charging by a charge of the same polarity as that of the particles of the initial beam, and an inner surface of the wall in form of a body of rotation; the channel narrows from the input to the output. The invention is characterised by that the outline of said surface is an arc of a smooth curve whose convex side faces the side opposite the longitudinal axis. The smallest radius R of curvature of said arc is linked to the highest energy E and charge Q of the particles in the beam by the relationship: E/Q<RdUnp/2r, which also includes the smallest thickness d of the wall of the channel, dielectric strength Unp of the material of the wall of the channel and the radius r of the input hole of the channel.
EFFECT: avoiding channel blocking, high transmission coefficient and possibility of controlling the shape of the output beam, including focusing thereof.
12 cl, 10 dwg
