Date: Friday 9th May 2025 – 11:00 (Europe/London)
Speaker: Prof Jorge Vieira, Computational and theoretical plasma physicist (GoLP/IPFN) and associate professor at Instituto Superior Técnico.
Watch the interview with Prof Jorge Vieira here https://youtu.be/Ze4EUfi0d_U
Abstract
Coherent light sources, such as free electron lasers, provide bright beams for biology, chemistry, physics, and advanced technological applications. As their brightness increases, these sources are also becoming progressively larger, with the longest being several km long (e.g. LCLS). Plasma accelerators are much more compact and can play a key role in bringing these sources to smaller laboratories. Reaching this goal requires orders of magnitude increase in the brightness delivered by plasma accelerator-based light sources. A radical enhancement of beam brightness in plasma accelerator light sources depends directly on the onset of temporal coherence and superradiance.
Here, we investigate a new radiation emission mechanism that may bring temporal coherence and superradiance to plasma accelerator-based light sources [1]. The concept makes use of the radiation produced by an ensemble of light-emitting particles exhibiting collective, matter-wave effects. Such collective motions, which can be as simple as a plasma wave, are pervasive in plasma physics and, notably, in plasma-based accelerators. We find that the trajectory of the centroid of such collective perturbation (which we denote as a quasi-particle) determines key radiation aspects, such as temporal coherence, just as if it were a single particle undergoing a similar trajectory.
We apply this concept to obtain superradiant emission using relativistic electron bunches, and in plasma accelerator-based light sources, to generate broadband and narrow bandwidth superradiant and temporally coherent radiation in the XUV/soft-xray region. We use theory and particle-in-cell simulations complemented by the Radiation Diagnostic for Osiris (RaDiO) [2], and discuss a recent experimental verification [3].
[1] B. Malaca et al, Nature Photonics 18, pages 39–45 (2024)
[2] M. Pardal et al, Comp. Phys. Communs. 285, 108634 (2023)
[3] S. Fu et al., Phys. Rev. Lett. 134, 045001 (2025).
Biography
Jorge Vieira is a computational and theoretical plasma physicist and an associate professor at Instituto Superior Técnico. He has specialised in laser-matter and beam-matter interactions at ultra-high intensities, combined with high performance computing as a tool to explore new, more compact plasma-based accelerators and light sources. In addition to his mentoring and supervision activities, he lectures on plasma physics, computational physics, and electromagnetism. He is also involved in several pan-european plasma-accelerator related projects such as EuPRAXIA, the advanced wakefield acceleration experiment (AWAKE) at CERN, and served as a member of the European expert panel for plasma-based accelerators for the 2020 update of the European strategy for particle physics.
