Collimated Ultra-Bright Gamma-Rays from a PW-Laser-Driven Wire Wiggler

TL;DR

This paper demonstrates through 3D QED particle-in-cell simulations that a 2.5 PW laser pulse can generate highly collimated, ultra-bright gamma-ray beams with unprecedented brilliance and energy, using a solid wire target.

Contribution

The study introduces a novel scheme for producing collimated gamma-ray beams via laser-driven wire wiggler, achieving higher brilliance and photon energy than existing sources.

Findings

Generated $10^{12}$ photons between 5-500 MeV within 10 fs.

Achieved peak brilliance of $10^{27}$ photons s$^{-1}$ mrad$^{-2}$ mm$^{-2}$.

Gamma-ray energy and number scale with laser power P$_0$ and P$_0^{3/2}$.

Abstract

It is shown by three-dimensional QED particle-in-cell simulation that as a laser pulse of 2.5 PW and 20 fs propagates along a sub-wavelength-wide solid wire, directional synchrotron $\gamma-$rays along the wire surface can be efficiently generated. With 8\% energy conversion from the pulse, the $\gamma-$rays contains $10^{12}$ photons between 5 and 500 MeV within 10 fs duration, corresponding to peak brilliance of $10^{27}$ photons ${\rm s^{-1}~ mrad^{-2}~ mm^{-2}}$ per 0.1\% bandwidth. The brilliance and photon energy are respectively 2 and 3 orders of magnitude higher than the highest values of synchrotron radiation facilities. The radiation is attributed to the generation of nC, GeV electron beams well guided along the wire surface and their wiggling motion in strong electrostatic and magnetostatic fields induced at the high-density-wire surface. In particular, these quasistatic fields are so strong that QED effects already play a significant role for the $\gamma-$ray radiation. With the laser power $P_0$ ranging from 0.5 PW to 5 PW available currently, this scheme can robustly produce $\gamma-$rays peaked at $1^\circ$ with few-mrad divergence and the photon energy and number roughly scales with $P_0$ and $P_0^{3/2}$, respectively. Our scheme embraces both the merits of high directionality comparable to those based upon laser wakefield acceleration and high charge comparable to those based upon laser-solid interaction.