Ultrahigh brilliance quasi-monochromatic MeV γ-rays based on self-synchronized all-optical Compton scattering.

Chenggang Yu ,Zhiyong Qin,Xiufeng Weng,Yuxin Leng,Cheng Wang,Wentao Li,Yi Xu,Ying Wu,Ming Fang,Zhizhan Xu,Rong Qi,Ruxin Li,Jiansheng Liu,Ye Tian,Yicheng Yi,Zhijun Zhang,Fuli Wei,Wentao Wang,Jihu Wang,Fenxiang Wu,Ke Feng,Song Zhang

doi:10.1038/srep29518

Abstract

Inverse Compton scattering between ultra-relativistic electrons and an intense laser field has been proposed as a major route to generate compact high-brightness and high-energy γ-rays. Attributed to the inherent synchronization mechanism, an all-optical Compton scattering γ-ray source, using one laser to both accelerate electrons and scatter via the reflection of a plasma mirror, has been demonstrated in proof-of-principle experiments to produce a x-ray source near 100 keV. Here, by designing a cascaded laser wakefield accelerator to generate high-quality monoenergetic e-beams, which are bound to head-on collide with the intense driving laser pulse via the reflection of a 20-um-thick Ti foil, we produce tunable quasi-monochromatic MeV γ-rays (33% full-width at half-maximum) with a peak brilliance of ~3 × 1022 photons s−1 mm−2 mrad−2 0.1% BW at 1 MeV. To the best of our knowledge, it is one order of magnitude higher than ever reported value of its kinds in MeV regime. This compact ultrahigh brilliance γ-ray source may provide applications in nuclear resonance fluorescence, x-ray radiology and ultrafast pump-probe nondestructive inspection.

Highlights

Inverse Compton scattering between ultra-relativistic electrons and an intense laser field has been proposed as a major route to generate compact high-brightness and high-energy γ-rays
Laser wakefield accelerators[1] (LWFA) have achieved significant progress recently owing to the sophisticated injections, cascade and guiding technologies[2,3,4,5,6,7,8], and they can produce monoenergetic, energy tunable, GeV-class femtosecond electron beams (e-beams) with tens of pC charge over a distance of centimeter-scale[6,8,9,10,11,12,13,14], which hold the potential of becoming compact alternatives to conventional radio-frequency-based linear accelerators[15]
We report the generation of quasi-monochromatic MeV γ-rays by using a self-synchronized all-optical Compton scattering scheme

Summary

Introduction

Inverse Compton scattering between ultra-relativistic electrons and an intense laser field has been proposed as a major route to generate compact high-brightness and high-energy γ-rays. Wiggling of the LWFA e-beams either in the conventional periodical magnetic field structures (undulator radiation)[17], strongly focusing laser wake-fields (betatron radiation)[18], or intense laser fields (Compton scattering)[19,20,21,22,23,24,25] have recently been experimentally realized to emit high-energy photons Of these schemes, the Compton scattering using LWFA e-beams, which has been successfully demonstrated to increase γ-rays’ brilliance by 10000 folds over that from the conventional accelerators, offers the most promising route to generate compact bright hard x- or γ-ray sources up to a few MeV, and will enable many practical applications. It can provide unique properties that may be of interest for a few practical applications such as ultrafast x-ray or γ-ray radiology and photonuclear research in the future

Methods

Results

Conclusion