Focusing of electron beams by laser-beam fields

Abstract

Employing the paraxial electron-trajectory equation of a cylindrical electron (beam) the theory of the focusing action of an enveloping annular laser beam is presented and discussed. Analogies between schemes employing laser-beam fields to focus electron beams and methods involving conventional ’’strong’’ and ’’quadrupole’’ focusing of electron beams are indicated. Some advantages and limitations of the suggested focusing method are pointed out. Also, some approximate numerical estimates regarding the parameters of a cylindrical electron beam and a (focusing) surrounding annular laser beam are obtained for a typical example.