Abstract
Abstract X/γ-rays have many potential applications in laboratory astrophysics and particle physics. Although several methods have been proposed for generating electron, positron, and X/γ-photon beams with angular momentum (AM), the generation of ultra-intense brilliant γ-rays is still challenging. Here, we present an all-optical scheme to generate a high-energy γ-photon beam with large beam angular momentum (BAM), small divergence, and high brilliance. In the first stage, a circularly polarized laser pulse with intensity of 1022 W/cm2 irradiates a micro-channel target, drags out electrons from the channel wall, and accelerates them to high energies via the longitudinal electric fields. During the process, the laser transfers its spin angular momentum (SAM) to the electrons’ orbital angular momentum (OAM). In the second stage, the drive pulse is reflected by the attached fan-foil and a vortex laser pulse is thus formed. In the third stage, the energetic electrons collide head-on with the reflected vortex pulse and transfer their AM to the γ-photons via nonlinear Compton scattering. Three-dimensional particle-in-cell simulations show that the peak brilliance of the γ-ray beam is $\sim 1{0}^{22}$ photons·s–1·mm–2·mrad–2 per 0.1% bandwidth at 1 MeV with a peak instantaneous power of 25 TW and averaged BAM of $1{0}^6\hslash$ /photon. The AM conversion efficiency from laser to the γ-photons is unprecedentedly 0.67%.
Highlights
Bright X/ -ray sources have various applications in the laboratory astrophysics, nuclear photonics, ultra-high density matter radiography, high-flux positron generation, nuclear medical imaging.[1,2,3,4,5,6] Hard X/ -rays are conventionally produced by large synchrotron facilities with peak brilliance in the range of 1 019 24 photons/s/mm 2 /mrad 2 /0.1 % BW and photon energy ranging from several keV to MeV
Laser-plasma-based X/ -photon sources have the advantages of compact size, relatively low cost, high beam brilliance and photon energy, making them extremely attractive for potential applications, especially in astrophysics and high energy physics.[7,8,9]
Significant progress has been made in experiments, to develop a table-top hard X/ -ray source, allowing a peak brilliance of the same order of magnitude as the synchrotrons at photon energy between 20 and 150 keV.[10,11,12]
Summary
Bright X/ -ray sources have various applications in the laboratory astrophysics, nuclear photonics, ultra-high density matter radiography, high-flux positron generation, nuclear medical imaging.[1,2,3,4,5,6] Hard X/ -rays are conventionally produced by large synchrotron facilities with peak brilliance in the range of 1 019 24 photons/s/mm 2 /mrad 2 /0.1 % BW and photon energy ranging from several keV to MeV. The huge size and high cost of these large infrastructures mean that access to these sources is limited. Due to the high photon energy, short pulse duration and small source size, it is very challenging to manipulate these -rays in a compact manner, e.g., the wave front, intensity distribution, and angular momentum
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
