Thermal effect on electron trajectory and growth rate in a two-stream free electron laser with a guide field

N. Mahdizadeh

doi:10.1063/1.5025104

Abstract

Temperature effects on the electron trajectory and growth rate are investigated for a two-stream free-electron laser (FEL) with a helical wiggler along with a guide magnetic field. Both longitudinal and transverse components of the beam temperature are including providing the full beam temperature effects. Two different cases namely, conventional and reversed guide field are considered. Based on the fluid theory, the dispersion relation for the right hand polarized of the electromagnetic wave, including the important influence of temperature is obtained and solved numerically. Two resonances occur in this model: FEL and two-stream FEL (TS-FEL) resonances. It is shown that both of the peak growths of the resonances are reduced due to temperature. However, peak growth rates are substantially affected owing to transverse component of the beam temperature. The result shows, in the case of a reversed guide field the TS-FEL resonance has low thermal sensitivity with respect to the conventional guide field.

Highlights

The free-electron lasers are one of the brightest source of UV to X-ray radiation available to the scientific community.1 They exhibit this exceptional brightness on a tunable range of photon energies while maintaining their coherence properties
Accelerated electrons are spatially injected in a periodic magnetic fields
We investigate the influence of both longitudinal and transverse components of the beam temperature in the form of Πα = 3nαKB[T⊥α I + T α − T⊥α bb]

Summary

INTRODUCTION

The free-electron lasers are one of the brightest source of UV to X-ray radiation available to the scientific community. They exhibit this exceptional brightness on a tunable range of photon energies while maintaining their coherence properties. The free-electron lasers are one of the brightest source of UV to X-ray radiation available to the scientific community.. The free-electron lasers are one of the brightest source of UV to X-ray radiation available to the scientific community.1 They exhibit this exceptional brightness on a tunable range of photon energies while maintaining their coherence properties. The FELs are seeded with an optical/X-ray beam to improve their bandwidth properties. Several aspects of TS-FELs with different wiggler field configurations have been studied, [Refs. Components of the electron beam temperature in a laboratory frame with respect to the local magnetic field, respectively.

STABILITY OF THE STEADY-STATE TRAJECTORIES

THE DISPERSION RELATION

D αB 0

NUMERICAL RESULTS AND CONCLUSION