Helical electron-beam microbunching by harmonic coupling in a helical undulator.
Microbunching of a relativistic electron beam into a helix is examined analytically and in simulation. Helical microbunching is shown to occur naturally when an e beam interacts resonantly at the harmonics of the combined field of a helical magnetic undulator and an axisymmetric input laser beam. This type of interaction is proposed as a method to generate a strongly prebunched e beam for coherent emission of light with orbital angular momentum at virtually any wavelength. The results from the linear microbunching theory show excellent agreement with three-dimensional numerical simulations.
Hemsing
E
E
Particle Beam Physics Laboratory, Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA.
Musumeci
P
P
Reiche
S
S
Tikhoplav
R
R
Marinelli
A
A
Rosenzweig
J B
JB
Gover
A
A