Focusing Properties of Magnetic Laminas and Their Applications to the Microtron

Abstract

The possibility of attaining vertical focusing in small accelerating machines, like the microtron, without destroying their marked simplicity, is pointed out. Indeed, it is shown that a vertical focusing in low energy accelerators can be obtained by the location of a magnetic lamina inside and at a suitable distance from the equilibrium orbit. In the case of the microtron, the location of the lamina inside the first orbit and at a distance from the resonant cavity of 0.42 times the radius of this orbit produces a vertical focusing for all orbits. Experiments performed on a 2.5 MeV microtron are in agreement with the theoretical predictions.