Decoupling acceleration and wiggling in a laser-produced Betatron source

Julien Gautier; Igor Andriyash; Andreas Döpp; Michaela Kozlova; Aimé Matheron; Benoit Mahieu; Cédric Thaury; Ronan Lahaye; Jean-Philippe Goddet; Amar Tafzi; Pascal Rousseau; Stéphane Sebban; Antoine Rousse; Kim Ta Phuoc

arXiv · 2506.22021

Decoupling acceleration and wiggling in a laser-produced Betatron source

Julien Gautier·Igor Andriyash·Andreas Döpp·Michaela Kozlova·Aimé Matheron·Benoit Mahieu·Cédric Thaury·Ronan Lahaye·Jean-Philippe Goddet·Amar Tafzi·Pascal Rousseau·Stéphane Sebban·Antoine Rousse·Kim Ta Phuoc

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Abstract

Betatron radiation is produced in Laser Plasma Accelerators when the electrons are accelerated and simultaneously wiggle across the propagation axis. The mechanisms of electron acceleration and X-ray radiation production follow different scaling laws, and the brightest X-ray radiation is often produced for an electron beam with a lower quality in terms of energy and divergence. Here, we report a laser-driven Betatron X-ray source where the plasma density profile is tailored in order to separate the acceleration and wiggler stages, which allows for the independent optimizations of acceleration and X-ray production. We demonstrate this concept experimentally, and show that the Betatron photon energy can be controlled by adjusting the length of the plasma wiggler. This scheme offers a path to overcome the limitations of conventional Betatron sources, enabling the production of bright, stable, energetic, and collimated X-ray beams.

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Julien Gautier, Igor Andriyash, Andreas Döpp, Michaela Kozlova, Aimé Matheron, Benoit Mahieu, Cédric Thaury, Ronan Lahaye, Jean-Philippe Goddet, Amar Tafzi, Pascal Rousseau, Stéphane Sebban, Antoine Rousse, Kim Ta Phuoc. 2025-06-27. Decoupling acceleration and wiggling in a laser-produced Betatron source. https://arxiv.org/abs/2506.22021

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