EuPRAXIA-DN Camp II: Science

13 Jul 2025, 18:00 → 15 Jul 2025, 17:00 Europe/Lisbon

Anfiteatro Abreu Faro (Instituto Superior Técnico)

Carsten Peter Welsch

The second EuPRAXIA Camp will shine a light on the breakthrough science that the EuPRAXIA facility will enable. Talks will explore how advanced accelerator technologies pave the way for more compact and versatile particle accelerators. The Camp will discuss next-generation light sources, the diverse research program enabled by direct laser acceleration, and much more.

This 2-day science workshop will be split into sessions led by invited keynote speakers who will first present the state-of-the-art in a particular area. This will then be followed by selected presentations from other workshop participants of either 12 or 25 minute duration. 

Generous discussion time will be included in each session and there will also be more general discussions at the end of each day linking between different areas. A poster session will complement the challenge-driven program. 

The EuPRAXIA Camps are open to everyone interested in the latest R&D results in plasma accelerators and not limited to members of EuPRAXIA. Participants are asked to suggest their contribution during registration and indicate if they would like to contribute a talk or a poster.

Abstract submission deadline: 31 May 2025

Registration deadline: 15 June 2025

Payment deadline: 15 June 2025

 

WIFI please use:

Account name: EuPRAXIA CAMPII

Password: A7jZn3

 

Hosted by:

EuPRAXIA-DN-Camp-II-poster.pdf

EuPRAXIA-DN-practical-information-Camp-II-v3.pdf

Sunday 13 July

18:00 → 21:00 Reception

Monday 14 July

08:30 → 09:00 Registration

09:00 → 09:30 Welcome / admin & logistics

Speakers: Rogério Colaço, Carsten Peter Welsch

EuPRAXIA-DN Camp II - Welcome.pdf

EuPRAXIA-DN Camp II - Welcome.pptx

09:30 → 10:30 Session 1: HPC for laser plasma accelerators

09:30 HPC for laser plasma accelerators

Speaker: Ricardo Fonseca (Instituto Superior Técnico, Universidade de Lisboa)

Fonseca EuPRAXIA Summer Camp II 2025.pdf

10:00 Metasurfaces for laser-plasma applications

The development of meta-optics with high-aspect ratio, ultratall nanopillars has opened up an advanced nanotechnology platform for the shaping of intense structured light. We will highlight the promises and challenges lying ahead for the control of laser-plasma applications.

Speaker: Prof. Marco Piccardo (INESC MN and Tecnico Lisboa)

Piccardo_EuPRAXIA_July 25.pptx

10:30 → 11:00 Coffee break

11:00 → 11:45 Session 1: HPC for laser plasma accelerators

11:00 Digital Twin-Enabled Modelling of Antimatter Beam Control: Insights from AEgIS to EuPRAXIA

The AEgIS experiment at CERN investigates the behaviour of antimatter under gravity, requiring precise spatial and temporal control of antiprotons (and other antimatter particles) using electrostatic and magnetic traps. In this contribution, a CST Studio Suite-based modelling workflow developed to simulate and optimize antiproton trapping configurations, including field homogeneity, electrode geometries, and potential well depth will be presented. These simulations have been instrumental in guiding hardware design decisions and layout choices for the experiment for the experimental campaigns.
This talk will discuss an early-stage implementation of a Digital Twin approach, where high-fidelity field simulations inform the design, operation, and eventual control of beamline components. The methods and insights developed are transferable to plasma accelerator contexts, particularly in optimizing trapping, focusing, and guiding systems under complex boundary conditions. By highlighting simulation-driven decision-making in a high-precision antimatter setup, the goal is to stimulate dialogue on integrating similar modelling pipelines into future plasma-based accelerator facilities, such as EuPRAXIA.

Speaker: Bharat Rawat (University of Liverpool)

EuPRAXIA-DN Camp II- Digital Twin-Enabled Modelling of Antimatter Beam Control Insights from AEgIS to EuPRAXIA.pptx

11:15 Generation of superradiant single cycle light pulses.

Plasma-based accelerators provide a compact and efficient means of generating ultra-relativistic particles [1], making them strong candidates for next-generation light sources. These X-ray sources are inherently ultrafast, highly-collimated, and energetic, with applications in biology, plasma physics, and material and high energy density science. These sources are compact and affordable but produce incoherent radiation. Making them coherent and superradiant will radically increase the attractiveness of these light sources, by placing them on equal footing to the brightness of X-ray sources today, such as free-electron-lasers (FEL).

One of the most consolidated X-ray source configurations in plasma accelerators is based on nonlinear Thomson scattering [2]. Here, relativistic electrons from a plasma-based accelerator interact with a counter or copropagating, intense laser pulse. Temporal coherence and superradiance are highly sought features in this context because the peak brightness increases very favourably with the number of light-emitting particles squared [3]. This is in stark contrast with temporally incoherent sources, where the peak intensity grows linearly with the number of emitters.

This work presents results on the generation of superradiant emission from electron bunches interacting with an azimuthally polarised laser pulse. We investigate how this interaction evolves at varying electron densities and examine the collective effects that lead to enhanced, superradiant radiation.

References
[1] T. Tajima and J. M. Dawson, Phys. Rev. Lett. 43, 267 (1979).
[2] E. Esarey et al., Phys. Rev. E 48, 3003 (1993).
[3] J. Vieira et al., Nature Physics 17, pages 99–104 (2021).

Speaker: Bhushan Thakur (Instituto Superior Tecnico, Lisbon)

Presentation_EuPRAXIA.pdf

11:30 Wavefront Reconstruction as a Gateway to Precision Science at EuPRAXIA

Recent advances in laser technology have significantly propelled the development of Laser Plasma Accelerators (LPAs). However, a critical factor influencing the quality and performance of the plasma-target interaction is the spatial structure of the laser pulse, especially its wavefront. To address this, we present, in collaboration with Dynamic Optics, an optimization software capable of real-time wavefront correction and enhancement, ensuring the highest achievable peak intensity at the laser focus. This capability is essential for maximizing the efficiency and stability of the laser-target interaction that ultimately unlocks a range of scientific and technological opportunities. LPAs with an active wavefront correction can support cutting-edge research in ultrafast phenomena, solid-state physics, and nonlinear optics. Most notably, they offer a transformative pathway for next-generation medical applications such as FLASH radiotherapy.

Speaker: David Gregocki (Consiglio Nazionale delle Ricerche - Istituto Nazionale di Ottica)

Camp_2_Gregocki.pptx

11:45 → 12:30 Group photo and lab tour

12:30 → 14:00 Lunch

14:00 → 16:00 Session 2: FEL driven by LWFA

14:00 FEL driven by LWFA

Speaker: Marie Emmanuelle Couprie (Synchrotron SOLEIL)

15:00 Development of a two-chamber LWFA target for fine electron injection control

Laser wakefield acceleration (LWFA) has seen great improvements in recent years, demonstrating the ability to generate high-energy, ultrashort electron beams in compact setups.
However, reproducibility remains a major challenge, with beam properties often affected by shot-to-shot fluctuations [1], caused by fluctuations in the laser system, inconsistencies in the plasma density profile, and stochastic processes in the electron injection and acceleration stages. Such limitations hinder the reliability and applicability of LWFA-based electron sources, particularly in precision-demanding fields like medical therapy [2] or advanced radiation sources such LWFA-driven X-FELs.
To address this, we present a novel two-chamber gas cell design that enables precise and tunable control over the plasma density profile along the laser propagation axis. By independently regulating the gas temperature in each chamber, longitudinal gas density modulation is achieved, allowing for a down-ramp injection scheme that supports reproducible, charge-tunable electron beam generation.
The cell's adjustable length further enhances control over the acceleration process, facilitating energy tuning and compatibility with a wide range of experimental conditions. This flexible, 10Hz-compatible design also enables real-time, automated optimization of LWFA performance (in line with previous successful experiments such as [3] and more recently [4]).
Computational fluid dynamics (CFD) simulations performed using OpenFOAM [5] suggest that the target can produce the desired gas density profiles. Additionally, a Bayesian optimization approach was applied to OSIRIS [6] particle-in-cell simulations to explore optimal laser and plasma density parameters within experimentally achievable ranges.

References
[1] Félicie Albert et al, 2020 roadmap on plasma accelerators, New J. Phys. 23 031101 (2021) https://iopscience.iop.org/article/10.1088/1367-2630/abcc62
[2] Labate, L., Palla, D., Panetta, D. et al. Toward an effective use of laser-driven very high energy electrons for radiotherapy: Feasibility assessment of multi-field and intensity modulation irradiation schemes. Sci Rep10, 17307 (2020). https://doi.org/10.1038/s41598-020-74256-w
[3] Shalloo 2020 - Shalloo, R.J., Dann, S.J.D., Gruse, JN. et al. Automation and control of laser wakefield accelerators using Bayesian optimization. Nat Commun11, 6355 (2020). https://doi.org/10.1038/s41467-020-20245-6
[4] Irshad 2024 - Irshad, F., Eberle, C., Foerster, et al Pareto optimization and tuning of a laser wakefield accelerator. Phys. Rev. Lett.133, 085001 (2024). https://doi.org/10.1103/PhysRevLett.133.085001
[5] OpenFoam - https://www.openfoam.com/.
[6] Fonseca, R.A. et al. (2002). OSIRIS: A Three-Dimensional, Fully Relativistic Particle in Cell Code for Modeling Plasma Based Accelerators. In: Sloot, P.M.A., Hoekstra, A.G., Tan, C.J.K., Dongarra, J.J. (eds) Computational Science — ICCS 2002. ICCS 2002. Lecture Notes in Computer Science, vol 2331. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-47789-6_36

Speaker: Diogo Lemos (GoLP, Instituto Superior Técnico)

2025_07_08_EuPRAXIA_Slides_DL_KeynoteFriendly.pptx

15:15 Beam transport system with active plasma lens for LPA-driven EUV FEL

Laser-Plasma Accelerators (LPAs) produce high-quality electron beams with high peak currents and low emittance, making them ideal for compact novel Free Electron Lasers (FELs). However, the large angular divergence and energy spread of these beams pose challenges for efficient beam transport overall FEL performance. This study explores the use of an Active Plasma Lens (APL) as a capture block to improve the transport of LPA-generated beams into an undulator. Initial beam parameters were based on published results from LWFA studies. In this report, we present the design of a LPA-based electron beamline operating in the EUV FEL regime. Our goal is to achieve saturation of the photon beam power within the undulator section. The results show that the APL enables efficient beam transport and facilitates the generation of high-brightness coherent X-rays.
This work underscores the potential of APLs in developing compact FELs and advancing LPA beams. This technology is essential for creating a new generation of FELs at ELI-ERIC in the Czech Republic and within the EuPRAXIA project.

Speaker: Mihail MICESKI

EuPRAXIA-DN_Camp-II_Lisabon.pdf

15:30 Diagnostics for ultrashort electron bunches in LWFA-driven FELs

Laser wakefield accelerators (LWFAs) produce electron bunches that are ideal for driving free-electron lasers (FELs), both in seeded and self-amplified spontaneous emission (SASE) configurations, making them candidates for achieving compact plasma-based FEL user facilities with their ultra-high accelerating gradients and small footprints. However, the inherent shot-to-shot fluctuations, large energy spread, and femtosecond-scale bunch lengths resulting from LWFA pose significant challenges to ensuring beam quality control and optimizing FEL performance. LWFA longitudinal bunch profiles can feature complex structures with a broad range of durations (fs to several tens of fs) and substructures (sub-fs to fs long) with small bunch charges in the pC to nC ranges, all bringing critical challenges for the measurements. This talk will provide a brief and broad overview of longitudinal diagnostics applicable to FELs, drawing on recent studies developed for both LWFA-based and traditional setups, with a focus on the requirements and applicability to plasma-based FEL lasing.

Speaker: Ana Maria Guisao Betancur (University of Liverpool)

EuPRAXIA-DN Camp II- Diagnostics for ultrashort electron bunches in LWFA-driven FELs.pptx

15:45 Optimization of FEL performance using modern LLRF systems

The performance of Free Electron Lasers (FELs) strongly depends on the stability, synchronization, and control of the electron beam that drives the lasing process. While Low-Level RF (LLRF) systems are a critical component regulating the amplitude, phase, and frequency of the RF accelerating fields within linac structures, they form part of a broader control system required to ensure overall beam quality and stability.
As FELs increasingly demand higher peak currents, shorter bunches, and sub-femtosecond timing precision, LLRF systems face increasingly stringent performance requirements. Modern digital LLRF systems must incorporate fast feedback, precise timing control, and real-time processing to meet these challenges particularly in high frequency regimes such as X-band, which require tight field stability and fast system response.
Advances in digital LLRF architectures, high-speed data converters, machine learning based control, and real-time FPGA processing are enabling new possibilities for enhancing FEL beam quality and operational flexibility. In particular, X-band accelerator structures present unique challenges and opportunities for LLRF integration, including improved temporal resolution and a reduced footprint.
This talk presents an overview of state-of-the-art LLRF system architectures, highlighting their role in enhancing beam stability, synchronization, and lasing performance, with a focus on next-generation FELs such as EuPRAXIA.

Speaker: Phani Deep Meruga

PD Meruga_EuPRAXIA_Camp-II_LLRF.pptx

16:00 → 16:15 Discussion session

16:15 → 16:45 Coffee break

16:45 → 18:00 Poster session

19:00 → 22:00 Workshop Dinner

Tuesday 15 July

09:00 → 10:30 Session 3: Betatron radiation – Theory

09:00 Betatron radiation – Theory

Speaker: Alessandro Curcio (Istituto Nazionale di Fisica Nucleare)

EupraxiaDN_Lisbon.pptx

10:00 Structured Light from Generalised Thomson Scattering

Structured light - light whose spatial and temporal profiles may be simultaneously tailored - offers new capabilities for controlling all degrees of freedom of an optical field and therefore its interaction with matter. Achieving such control requires tunable spatiotemporal spectra.

Separately, Thomson scattering is a known process in which the collision of energetic particle bunches and intense laser beams results in short bursts of high frequency radiation. This allows for the control of the temporal degree of freedom of the resulting radiation.

In this talk, we present a generalised Thomson scattering formalism that also enables the accurate control of the spatial structured of the emitted radiation. This approach allows the generation of arbitrarily structured light pulses from the interaction of relativistic particle bunches with intense structured lasers. As a concrete example, we use this approach to convert orbital angular momentum (OAM) of the driver laser into transverse optical angular momentum (TOAM) in the radiation field, thereby creating spatiotemporal optical vortices (STOV) in Thomson scattering experiments. This framework opens a new path toward generating structured high-frequency light with full spatiotemporal control.

Speaker: Rafael Almeida (GoLP / Instituto de Plasmas e Fusão Nuclear Instituto Superior Técnico, Lisbon, Portugal)

20250715_EupraxiaCamp2.pdf

10:15 Investigation of Gamma-Radiation Background Using sCVD Diamond Detectors

Radiation background poses a challenge in the accurate evaluation of radiation environments, such as in neutron spectroscopy, and beam monitoring. In particular, gamma-radiation background complicates the measurement of low-energy particles. Understanding the methodology for discriminating gamma-radiation background can significantly improve the accuracy of radiation measurements in mixed radiation fields. The primary objective of this study is to investigate the gamma-radiation sensitivity of single-crystal Chemical Vapor Deposition (sCVD) diamond sensors with respect to varying thicknesses. The measurements were performed at the thermal neutron beamline of the TRIGA Center, Atominstitut, Wien, Austria.

Speaker: Divya Divya (TU Wien & CIVIDEC Instrumentation GmbH)

DD_Lisbon_2025.pdf

10:30 → 11:00 Coffee break

11:00 → 12:30 Session 4: Direct Laser Acceleration

11:00 Direct Laser Acceleration

Speaker: Marija Vranic (GoLP/IPFN - Instituto Superior Tecnico)

MVranic-DLA-EupraxiaCamp.pdf

12:00 Optical Synchrotron Radiation as a Non-Invasive Tool for emittance diagnostics

As next-generation accelerators target higher brightness and lower emittance, conventional diagnostics may fall short. Optical Synchrotron Radiation (OSR), while coupled with an optimized optical transport system, offers a scalable, high-resolution alternative. We apply a robust simulation framework for using OSR as a non-invasive tool to extract the transverse emittance of relativistic electron beams in advanced accelerator facilities.

Using the Synchrotron Radiation Workshop (SRW) code, we model OSR emission and propagation through realistic optics, incorporating detector and transport effects. Feasibility of this emittance measurement study was assessed using a microlens array (MLA) system to capture angular beam distributions from OSR. To validate the imaging performance, we integrate SRW with optical ray-tracing simulations in Zemax. Successful reconstruction of the emittance and Twiss parameters from the simulated results in the end validate the framework’s accuracy in optimizing beam diagnostics.

The method is benchmarked using beam conditions from the CLEAR facility at CERN, while also providing a blueprint for extending OSR-based emittance diagnostics to other facilities.

Speaker: Debdeep Ghosal (University of Liverpool)

EuPRAXIA-DN Camp II- Emittance Diagnostics_withOSR_new.key

EuPRAXIA-DN Camp II- Emittance Diagnostics_withOSR_new.pdf

12:15 Gas-Jet Diagnostics for Precision Science at EuPRAXIA

Precise and reliable beam delivery is of paramount importance across a wide range of multidisciplinary applications, particularly in the medical field, where accuracy in dose administration directly impacts treatment efficacy and patient safety. In this context, non-invasive and real-time beam monitoring technologies play a crucial role by enabling continuous verification of beam parameters without interfering with the beam itself.

At the Cockcroft Institute, a novel, minimally invasive online beam monitoring system has been developed, employing a gas-jet-based Ionization Profile Monitor (IPM). This technology is specifically designed to meet the demanding requirements of medical accelerators, particularly in advanced proton and ion beam therapy. These therapies require highly accurate spatial and dosimetric control of particle beams, and traditional invasive methods often fall short in providing online monitoring during treatment. The gas-jet IPM addresses these limitations by allowing real-time, non-disruptive monitoring of the beam profile through the controlled ionization of a thin gas jet intersecting the beam path.

Beyond its application in medical accelerators, the performance of the gas-jet-based IPM demonstrates its suitability for a broad range of other scientific and industrial domains. These include high-precision material irradiation studies, radioisotope production for medical and industrial use, and beam diagnostics in conventional proton and ion accelerator facilities. The system's ability to provide detailed beam profile information without perturbing the beam makes it a valuable diagnostic tool across these diverse applications.

In this work, the underlying working principles of the gas-jet Ionization Profile Monitor, detailing its design, implementation, and operational mechanisms are presented. Furthermore, its potential to significantly enhance beam diagnostics and control in both clinical and research environments, highlighting its role as a versatile solution to current beam monitoring challenges, is discussed.

Speaker: Mrs Farhana Thesni Mada Parambil (University of Liverpool/ Cockcroft Institute)

EuPRAXIA_Camp-II_Lisbon_Farhana.pptx

12:30 → 14:00 Lunch

14:00 → 15:45 Session 5: Laser-induced Plasma Science

14:00 Plasma-based particle acceleration

Speaker: Raoul Trines (STFC)

EuPRAXIA-DN Camp II- Plasma-based particle acceleration.pptx

15:00 Unlocking Atomic Motion: Dielectric THz-Driven Accelerators for Ultrafast Electron Microscopy and Diffraction

High-resolution electron microscopy (HREM) and ultrafast electron diffraction (UED) are crucial techniques in material science, biology, and chemistry. They enable researchers to visualize atomic structures and observe fastchanging processes, such as phase transitions, changes in molecular shapes, and chemical reactions, with high spatial and temporal accuracy. However, current electron sources have limitations regarding temporal resolution, brightness, and beam quality, which restrict their ability to effectively study ultrafast or fleeting phenomena in
complex systems.

Recent progress with Dielectric Terahertz-driven Accelerators (DTAs) provides a promising improvement. These compact devices operate within the THz range and use strong accelerating fields, exploiting shorter wavelength capabilities for particle acceleration and manipulation. Their design allows for the generation of high-quality electron beams. THz-linear accelerators can produce electron bunches lasting less than 100 femtoseconds, with an energy spread of less than 0.1%, very low transverse emittance (less than 0.1 nm·rad), and energies in the multi-MeV range.

Using these electron beams in HREM and UED would enable real-time imaging of atomic-scale movements with unmatched spatiotemporal resolution. In materials science, this advancement would permit direct observation
of rapid lattice changes and the movement of nanoscale defects. In biology, researchers could capture the motions of proteins or viral capsids with little radiation damage. In chemistry, they would allow for the visualization of transition states and reaction pathways as they occur. Therefore, THz-driven dielectric acceleration marks a significant advancement in fundamental research, providing access to beam qualities that were previously available only at huge facilities.

Speaker: Andrés Leiva Genre

EuPRAXIA-DN Camp II- Unlocking atomic motion - Dielectric THz-driven Accelerators for ultrafast electron microscopy and diffraction.pdf

EuPRAXIA-DN Camp II-Unlocking atomic motion - Dielectric THz-driven Accelerators for ultrafast electron microscopy and diffraction.pptx

15:15 Plasma-Based Acceleration of Decaying Particles

Plasma-based accelerators achieve accelerating fields of 10-100 GV/m. While plasma wakefields naturally accelerate electrons due to their near-light-speed motion [1,2], heavier particles like muons [3] and pions, with lifetimes from microseconds to nanoseconds, struggle to be trapped due to velocity mismatch with the wake.

We use spatio-temporal spectral shaping [4,5,6] to control the group velocity of drive pulses, generating subluminal wakes suitable for slower particles. PIC simulations with OSIRIS [7] show non-relativistic particles accelerating to relativistic speeds. By tailoring the plasma density profile, we can extend the dephasing length, which sustains the acceleration process.
This method enables plasma-based acceleration of unstable particles, with applications in cooled muon injection and enhanced muon yield via pion acceleration and decay.

[1] T. Tajima and J. M. Dawson, Physical Review Letters 43, 267 (1979).
[2] C. Joshi, Physics Today 56 (6), 47 (1993).
[3] K.R. Long, et al., Nature Physics 17, 289–292 (2021).
[4] A. Sainte-Marie et al., Optica 4, 1298-1304 (2017).
[5] Froula, D.H., Turnbull, D., Davies, A.S. et al., Nature Photonics 12, 262–265 (2018).
[6] H. Kondakci, Y. F. Abouraddy, Nature Communications 10, 929 (2019).
[7] R.A. Fonseca et al., Phys. Plasmas Control. Fusion 55, 124011 (2013).

Speaker: Chiara Badiali

eupraxiacamp_CB.pptx

15:30 Relativistic beam-plasma instabilities

The interaction of relativistic particle beams with plasmas underpins a broad range of physical systems — from the dynamics of AGN jets and Gamma-Ray Bursts to next-generation plasma-based accelerators. In both astrophysical and laboratory scenarios, these beam-driven plasma instabilities play an important role on the interplay of kinetic and electromagnetic energy. Understanding the growth and nonlinear evolution of these instabilities is essential for predicting energy transfer, particle acceleration, and high-energy radiation generation.

In this presentation, we will introduce a novel analytical framework that captures, for the first time, the spatiotemporal evolution and coupling mechanisms of a full class of streaming instabilities — including the Current Filamentation Instability (CFI), Two-Stream Instability (TSI), Oblique Instability, and Self-Modulation Instability (SMI) — driven by relativistic beams propagating through a background plasma. The model is derived under the quasi-static approximation, exploiting the large disparity in timescales between the dilute, relativistic driver and the fast plasma response of the ambient medium.

Benchmarking against Particle-In-Cell (PIC) simulations, both quasi-static and fully kinetic, reveals excellent agreement, validating the model across a wide range of parameters. This opens a new modeling regime for highly relativistic, low-density beam–plasma systems — including those of relevance to laboratory astrophysics and advanced accelerator testbeds such as EuPRAXIA.

In addition to the theoretical and computational developments, this presentation will also outline the potential experimental campaigns that could be implemented at EuPRAXIA to study beam-plasma instabilities. These include scenarios involving relativistic electron beams interacting with underdense plasmas, where signatures of self-modulation, filamentation, and beam-induced wakefields can be diagnosed through state-of-the-art diagnostics. Such experiments would offer a unique opportunity to bridge theoretical, computational, and experimental plasma physics under controlled beam conditions.

Speaker: Pablo San Miguel (Ecole Polytechnique)

PSM_EuPraxia_camp_15_07_25_sheareble.pdf

15:45 → 16:00 Putting it all together / Discussion

Speaker: Carsten Peter Welsch

16:00 → 16:20 End of workshop