Determn. of emittance of beam of charged particles - permitting beam of predetermined dimensions to be obtd. at zone of utilisation

摘要

Determn. comprises measuring the max. elongation of the beam at two points in its trajectory, one downstream of the other, and the max. elongation at the downstream point when the beam is subjected to the action of a quadripolar lens of convergence C placed near the upstream point, the distance between the lens and the downstream point being equal to 1/C. The appts. consists of a first measuring system, giving the max. elongation at a point P1 in a plane Q perpendilar to the trajectory along a specified axis X1X1. A second measuring system gives the max. elongation at a point P2 downstream of P1 in a plane parallel to plane Q and along an axis X2X2, parallel to X1X1. A magnetic lens is present of the quadripolar type. Any system of guiding the beam can be regulated, in an optimum way, to obtain in the area of utilisation, e.g. a target, a beam of predetermined dimensions.