Photon yield of superradiant inverse Compton scattering from microbunched electrons

Abstract

Compact X-ray sources offering high-brightness radiation for advanced imaging applications are highly desired. We investigate, analytically and numerically, the photon yield of superradiant inverse Compton scattering from microbunched slectrons in the linear Thomson regime, using a classical electrodynamics approach. We show that for low electron beam energy, which is generic to inverse Compton sources, the single electron radiation distribution does not match well to collective amplification pattern induced by a density modulated electron beam. Consequently, for head-on scattering from a visible laser, the superradiant yield is limited by the transverse size of typical electron bunches driving Compton sources. However, by simultaneously increasing the electron beam energy and introducing an oblique scattering geometry, the superradiant yield can be increased by orders of magnitude.

Isolated attosecond X-ray pulses from superradiant thomson scattering by a relativistic chirped electron mirror

“…In the beer-can beam regime, where 1 ≫ CEM , destructive interference due to the transverse size dominates, significantly limiting the pulse energy of the attosecond pulse. This effect can be compensated for by focusing to a small waist or going to high beam energy and introducing a oblique scattering geometry such that the angles better overlap 29 .…”

“…Superradiant emission, describing only the constructive interfering part of the reflected radiation, occurs when the phase difference of the radiation from spatially separated emitters is equal to an integer n of 2π . For superradiant TS of radiation at frequency ω 1 , a density modulated electron beam should have a bunching frequency 29 However, in chirped pulse compression the laser frequency is not constant but varies with time. The use of a frequency chirped laser pulse has been proposed before to compensate for bandwidth broadening in incoherent TS [30][31][32] .…”

Free-electron crystals for enhanced X-ray radiation

“…Spontaneous light emission driven by free electrons is one of the most fundamental interactions in quantum electrodynamics (QED). Serving as the cornerstone for a wide range of tunable light sources, these emission processes come in various forms and span many octaves from the THz regime to the X-ray regime, e.g., bremsstrahlung 1 , 2 , Cherenkov radiation 3 – 10 , transition radiation 11 , 12 , inverse Compton scattering 13 – 15 , Smith–Purcell radiation 8 , 16 – 25 , undulator 2 , 26 – 28 , and synchrotron radiation 29 .…”