Tunable charged particle vortex beam generator and method

A charged particle vortex beam generator, the generator comprising

• one or more components for providing a charged particle beam, the one or more components configured to provide an electrical arrangement which imparts an orbital angular momentum to the charged particle beam during operation, wherein the electrical arrangement comprises at least one electrical conductor for providing a first electrical current flowing in a first direction and a second electrical current flowing in a second opposite direction, wherein the first direction is antiparallel to the second direction,
• wherein a section of the electrical conductor for said first electrical current makes an acute angle (a) with the charged particle beam path and wherein a section of the electrical conductor for said second electrical current makes an acute angle (a) with the charged particle beam path,
• wherein the section of electrical conductor for said first electrical current and the section of the electrical conductor for said second electrical current both extend to the center of the charged particle beam.