Understanding the focusing of charged particle for 2D sheet beam in a cusped magnetic field

TL;DR

This paper analyzes how a cusped magnetic field can focus high-current sheet beams, clarifying the underlying physics and dynamics using a simplified single-electron model to enhance understanding of beam behavior.

Contribution

It provides an intuitive analysis of sheet beam focusing in cusped magnetic fields, addressing misconceptions about non-uniform fields guiding particle beams.

Findings

Cusped magnetic fields can effectively focus sheet beams with less axial field requirement.

The analysis highlights the importance of beam geometry and magnet positioning.

Particle dynamics depend on radius, velocity, and curvature within the cusped field.

Abstract

The requirement of axial magnetic field for focusing and transportation of sheet beam using cusped magnets is less as compared to solenoid magnetic fields which is uniform. There is often some confusion about how a cusped magnetic field focuses high current density sheet beam because it is generally understood that non-uniform magnetic field cannot guide the particle beam along its axis of propagation .In this paper, we perform simple analysis of the dynamics of sheet beam in a cusped magnetic field with single electron model and emphasize an intuitive understanding of interesting features (as beam geometry, positioning of permanent magnets, particle radius,particle velocity,radius of curvature of particle inside cusped magnetic field)