2014/01/13 by Rui Li, Li, Rui
Engineering · Physics and Astronomy · #Accelerator Physics (physics.acc-ph) #FOS: Physical sciences #Geophysics and Sensor Technology #Particle Accelerators and Free-Electron Lasers #Quantum Electrodynamics and Casimir Effect #physics.acc-ph
paper · pdf · doi:10.48550/arxiv.1401.2868
arxiv created 2014/01/13 · openalex publication_date 2014/01/13 · arxiv updated 2014/01/14 · openalex created_date 2017/01/06 · openalex updated_date 2026/07/28
In the previous canonical formulation of beam dynamics for an electron bunch moving ultrarelativistically through magnetic bending systems, we have shown that the transverse dynamics equation for a particle in the bunch has a driving term which behaves as the centrifugal force caused by the particle's initial potential energy due to collective particle interactions within the bunch. As a result, the initial potential energy at the entrance of a bending system, which we call pseudo (kinetic) energy, is indistinguishable from the usual kinetic energy offset from the design energy in its perturbation to particle optics through dispersion and momentum compaction. In this paper, in identifying this centrifugal force on particles as the remnant of the CSR cancellation effect in transverse particle dynamics, we show how the dynamics equation in terms of the canonical momentum for beam motion on a curved orbit is related to the Panofsky-Wenzel theorem for wakefields for beam motion on a straight path. It is shown that the effect of pseudo energy spread can be measurable only for a high-peak-current bunch when the pseudo slice energy spread is appreciable compared to the slice kinetic energy spread. The implication of the pseudo slice energy spread for bunch dynamics in magnetic bends is discussed.