257 / 2023-04-21 21:21:35

A path for optimizing direct laser acceleration

极端光下的基础物理学 > 粒子加速-I

The near-future laser facilities will allow exploring new regimes of laser-driven particle acceleration. I

will present a recent work introducing the theoretical background for the optimal acceleration of

electrons in gaseous targets by multi-PW lasers. The acceleration is achieved due to the resonance

between the fast oscillations in the field of a laser pulse and betatron oscillations in an ion channel

created by the ponderomotive force of the laser pulse (known in the community as direct laser

acceleration - DLA). We analytically explain the effect of a transverse displacement from the channel

axis of accelerated electrons on the energy that electrons can achieve at given initial conditions.

Uncovering this non-linear dependence allows to construct the scaling of maximum energies as a

function of plasma density and laser intensity that is in good agreement with full-scale Quasi-3D

particle-in-cell simulations. We also demonstrate that proper focusing of the laser pulse and guiding

over a sufficiently long distance can lead to the acceleration of 100s of nC charge electron bunch with

energies exceeding 10 GeV [1]. This can be beneficial for many possible applications in high-energy

QED regime such as the seeding of QED cascades or the creation of a significant amount of positrons

that can be used in electron-positron collider.

[1] https://doi.org/10.48550/arXiv.2304.10469