5th Smilei user & training workshop

19 Mar 2025, 08:45 → 21 Mar 2025, 18:00 Europe/Madrid

ETSIAE (U. P. Madrid)

For its 5th iteration, the Smilei user & training workshop is hosted in Madrid (Spain) by ETSIAE from March 19th to 21st, 2025. You will have the opportunity to present your research, review the latest news on Smilei, and for newcomers, learn how to use Smilei on a supercomputer. Coffee and lunches will be provided on site.

There is no participation fee, but registration is mandatory.

Programme

• 1st day: Project status by the Smilei team + presentations from users
• 2nd and 3rd days: Courses and hands-on training sessions with access to a supercomputer (limited to 30 participants)

Organizers

• ETSIAE: Javier Honrubia
• Scientific commitee: Yasmina Azamoum, Jan Psikal
• Smilei devs: Arnaud Beck, Guillaume Bouchard, Mickael Grech, Francesco Massimo, Frédéric Perez, Charles Prouveur, Tommaso Vinci

Links

• Smilei's main website and documentation
• Repository on GitHub
• Chatroom
• Previous workshop

 

Feedback

https://framaforms.org/5th-smilei-trainings-1742486474

02_Ecosystem-2025.pdf

Achieving_performance.pdf

Advanced-techniques.pdf

B.Corobean_Peeler_Acceleration_Scheme.pdf

B.Schmitz_Modeling_of_a_Liquid_Leaf_Target_TNSA_Experiment_using_Particle-In-Cell_Simulations_and_Deep_Learning.pdf

Hue_Do_PIC_Simulations_of_Quantum_Plasmas.pdf

M.Jirka_Effects_of_colliding_laser_pulses_polarization_on_e−e+_cascade_development_in_extreme_focusing.pdf

P.Sikorski_Novel_signatures_of_radiation_reaction_in_electron–laser_sidescattering.pdf

Parallelization.pdf

PIC-Basics.pdf

Planning.pdf

RucheCommands.html

Run_on_GPU.pdf

Status_Perspectives.pdf

SuperComputingLandscape.pdf

Wednesday 19 March ¶

08:45 → 09:30 Check-in & Welcome coffee

09:30 → 10:40 Smilei: Project review¶

09:30 Introduction¶

09:40 Smilei: Status and perspectives¶

Speaker: Arnaud Beck (LLR (CNRS, Ecole polytechnique))

Status_Perspectives.pdf

10:10 Smilei: Ecosystem¶

Speaker: Tommaso Vinci (LULI - Ecole Polytechnique)

10:40 → 11:10 Contributed talks: by Users¶

10:40 Novel signatures of radiation reaction in electron–laser sidescattering¶

The phenomenon of radiation reaction describes the fact that accelerated charged particles emit radiation that carries away energy and momentum and, hence, the radiation emission must act back onto the motion of the particles. Those effects are expected to affect laser-plasma accelerators in the near future. This presentation explores novel signatures of radiation reaction via the angular deflection of an electron beam colliding at 90 degrees with an intense laser pulse. Due to the radiation reaction effect, the electrons can be deflected towards the beam axis for plane wave backgrounds, which is not possible in the absence of radiation reaction effects. The magnitude and size of the deflection angle can be controlled by tailoring the laser pulse shapes. The effect is first derived analytically using the Landau–Lifshitz equation, which allows to determine the important scaling behavior with laser intensity and particle energy. These findings are validated through comprehensive 1D and 3D simulations performed using the SMILEI PIC-code, employing both the classical and quantum radiation reaction models, thus confirming the phenomenon's observability with current laser technology.

Speaker: Philipp Sikorski

Sikorski_2024_New_J._Phys._26_063011 (2).pdf

11:10 → 11:35 Coffee

11:35 → 12:50 Contributed talks: by Users¶

11:35 Particle-In-Cell Simulations of Quantum Plasmas¶

Room-temperature metals and semi-metals, characterized by bound electron gases in near-continuum band structures, can be viewed as cold quantum plasmas. This perspective enables the adaptation of Particle-in-Cell (PIC) simulations, traditionally used for classical plasmas, to model dynamic phenomena in nanophotonics and plasmonics. In our work, we have extended the capabilities of the SMILEI PIC code by implementing four innovative physics modules: (I) initialization of Fermi-Dirac distributed charge species, (II) material boundary conditions tailored for condensed matter interactions, (III) a bound-particle model enabling the simulation of linear dispersive media, and (IV) a framework for modeling massless Dirac fermions to simulate graphene-like materials. These additions provide a versatile and self-consistent platform for exploring dynamic electromagnetic responses in nanophotonic and plasmonic systems [1][2][3].
This talk outlines the integration of these modules into the SMILEI framework and their role in enhancing quantum plasma modeling. We discuss practical considerations during implementation, including adapting the modified Boris scheme for new particle dynamics: bound electrons and massless Dirac electrons, and present benchmark simulations validating the updates. These results highlight the augmented SMILEI code's potential for studying time-dependent phenomena in quantum plasmas, such as interband plasmon resonances and nonlinear Dirac electron dynamics. By sharing these developments, we aim to support further exploration of quantum materials and nanophotonic systems using mesoscopic particle simulations [4].

[1] Ding, W. J. et al. Particle simulation of plasmons. Nanophotonics 9, 3303–3313 (2020)
[2] Do, H. T. B. et al. Electron dynamics in plasmons.
Nanoscale 13, 2801–2810 (2021).
[3] Do, H. T. B. et al. Nonlinear Terahertz Resonances from Ballistic Electron Funnelling. Preprint at https://doi.org/10.48550/arXiv.2411.09212.
[4] Ngirmang, G. K. et al. Particle-In-Cell Simulations of Quantum Plasmas. Preprint at https://doi.org/10.48550/arXiv.2501.07465.

Speaker: Hue Do (National University of Singapore)

2501.07465v1.pdf

12:00 Simulations of wave generation by electron beams using cylindrical simulation frame¶

During peaks of magnetospheric activity, energetic electrons trapped in the inner magnetosphere can precipitate in the lower ionosphere due to electromagnetic wave activity. Such waves can be generated naturally or artificially, for instance, through the emission of plasma beams. In this work, we study waves generated by electron beams emitted parallel to the magnetic field using SMILEI. We take advantage of the rotational symmetry of the problem and use a cylindrical frame, to reduce the simulation to a 2D problem. This computational gain allowed us to investigate the impact of the beam characteristics (such as beam density, frequency, length, etc.) on the wave generation, and the structural evolution of the beam as it exchanges energy with the electromagnetic fields and interacts with the background plasma.

Speaker: Jérémy Dargent (Laboratoire de Physique des Plasmas)

12:25 Non-equilibrium formation and dynamics of fundamental plasma structures: importance of kinetic physics¶

Fundamental magnetized plasma structures such as current sheets and flux tubes have textbook solutions for equilibrium, e.g., the Harris sheet and the Bennett pinch, which describe a balance between the magnetic and thermal forces in a plasma. However, in actual spacecraft measurements of these structures in space, various characteristics such as their magnetic profiles do not match the textbook solutions. For example, current sheets that have bifurcated structures have been observed for decades, with origins that have eluded scientists. In this talk, I will show how the details of these structures can be explained by considering the kinetic aspects of their formation process. Particle orbit transitions leave distinct footprints in the distribution function in phase space, which are translated to kinetic equilibrium profiles that cannot be explained by MHD. Particle-in-cell simulations are used to probe this evolution in real time, and the resulting plasma profiles are shown to agree strikingly with spacecraft observations.

Speaker: Young Dae Yoon (Asia Pacific Center for Theoretical Physics)

12:50 → 13:40 Lunch

13:40 → 14:50 Poster session¶

14:50 → 15:20 Smilei: Project review¶

14:50 Smilei: Supercomputing Landscape¶

Speaker: Charles Prouveur (CNRS, MdlS)

15:20 → 16:10 Contributed talks¶

15:20 Quasi-monochromatic carbon ion beams with the “peeler” acceleration scheme¶

The “peeler” scheme, originally proposed for proton acceleration, involves irradiating the narrow (sub-micron) side of a solid tape target. A large number of electrons are extracted by the laser pulse and travel to the target rear, creating a strong space charge field. This accelerates and collimates hydrogen ions found in the contaminant layer, resulting in a proton beam with an energy spectrum peaked near the maximum energy. However since heavier ions, such as carbon, have a lower charge-to-mass ratio, they are more difficult to accelerate and still show an exponentially decaying energy spectrum in the standard case.

Using full 3D simulations with the particle-in-cell code SMILEI, we optimize this process in order to obtain high peak energy, quasi-monochromatic and low divergence carbon ion beams. This is achieved by placing low density carbon structure, with dimensions on the order of a few hundred nanometers, at the target rear, replacing the contaminant layer as the ion source. Potential applications for these ion beams include radiotherapy, fast ignition studies, and nuclear physics.

Speaker: Bogdan Corobean (UNSTPB, ELI-NP)

Smilei_workshop_B_Corobean

15:45 Unforeseen advantage of looser focusing in vacuum laser acceleration¶

Acceleration of electrons in vacuum directly by intense laser fields holds great promise for the generation of high-charge, ultrashort, relativistic electron bunches. While the energy gain is expected to be higher with tighter focusing, this does not account for the reduced acceleration range, which is limited by diffraction. Here, we present the results of an experimental investigation that exposed nanotips to relativistic few-cycle laser pulses. We demonstrate the vacuum laser acceleration of electron beams with 100s pC charge and 15 MeV energy. Two different focusing geometries, with normalized vector potential a0 of 9.8 and 3.8, produced comparable overall charge and electron spectra, despite a factor of almost ten difference in peak intensity. The experimental findings are in good agreement with 3D particle-in-cell simulations performed using SMILEI code, which indicate the importance of dephasing.

Speaker: Shikha Bhadoria (Max Planck Institute for Nuclear Physics)

16:10 → 16:35 Coffee

16:35 → 18:00 Contributed talks: by Users¶

16:35 Effects of colliding laser pulses polarization on e-e+ cascade development in extreme focusing¶

The onset and development of electron-positron cascade in a standing wave formed by multiple colliding laser pulses requires tight focusing in order to achieve the maximum laser intensity. There, steep spatiotemporal gradients in the laser intensity expel seed particles from the high-intensity region and thus can prevent the onset of a cascade. We show that radially polarized laser pulses ensure that the seed electrons are present at the focal plane at the moment of the highest amplitude even in the case of extreme focusing. This feature reduces the required laser power for the onset of a cascade 100 times (80 times) compared to circularly (linearly) polarized laser pulses having the same focal spot radius and duration.

Speaker: Martin Jirka (Czech Technical University in Prague)

17:00 Modelling any kind of "smoothed" laser beams with Smilei¶

Optical smoothing is a technique used to smooth out the laser focal spot of kJ/nanosecond class laser beams in Inertial Confinement Fusion experiments. Instead of being a perfect Gaussian or near-Gaussian beam with a well defined temporal envelope, the laser light is the result of a complicated interference pattern constituted of many intense spots -called speckles- moving and or blinking during the pulse duration.
We will explain different optical smoothing techniques such as Smoothing by Spectral Dispersion, Induced Spatial Incoherence with continuous spectrum (broadband) beams and with multi-colour beams. The qualitative and quantitative description of such light beam will be directly linked with the mathematical representation done in Smilei. We will also address the challenges encountered in the simulation process and introduce the different applications of optical smoothing for laser-plasma interactions.

Speaker: Dr Arnaud Debayle (Focused Energy)

17:25 Modeling of a Liquid Leaf Target TNSA Experiment Using Particle-In-Cell Simulations and Deep Learning¶

Liquid leaf targets show promise as high repetition rate targets for laser-based ion acceleration using the Target Normal Sheath Acceleration (TNSA) mechanism and are currently under development. This work discusses the effects of different ion species and investigates how they can be leveraged as a laser-driven neutron source. Based on artificial neural networks, we developed a surrogate model for liquid leaf target laser-ion acceleration experiments to aid in this research. The model is trained using data from Particle-In-Cell (PIC) simulations. The fast inference speed of our deep learning model allows us to optimize experimental parameters for maximum ion energy and laser-energy conversion efficiency. An analysis of parameter influence on our model output, using Sobol’ and PAWN indices, provides deeper insights into the laser-plasma system.

Speaker: Benedikt Schmitz (TU Darmstadt)

Thursday 20 March ¶

09:00 → 09:30 Coffee

09:30 → 10:45 Smilei: The PIC method and its parallelization¶

09:30 Smilei: PIC Basics¶

Speaker: Mickael GRECH (LULI, CNRS)

10:10 Smilei: Parallelization¶

Speaker: Frederic Perez (LULI)

10:45 → 11:05 Coffee

11:05 → 13:00 Training: First contact with Smilei¶

13:00 → 14:00 Lunch

14:00 → 15:20 Smilei: Beyond PIC¶

14:00 Smilei: Advanced numerical methods¶

Speaker: Francesco Massimo (LPGP - CNRS)

Workshop2025_Advanced-techniques.pdf

14:45 Smilei: Additional physics modules¶

Speaker: Guillaume Bouchard (Université Paris-Saclay, CEA, LMCE, France)

15:20 → 15:40 Coffee

15:40 → 17:15 Training: PIC basics¶

Friday 21 March ¶

09:00 → 09:30 Coffee

09:30 → 10:10 Smilei: New technologies¶

09:30 Smilei: Achieving performances¶

Speaker: Arnaud Beck (LLR (CNRS, Ecole polytechnique))

09:50 Smilei: Running on GPU¶

Speaker: Charles Prouveur (CNRS, MdlS)

10:10 → 13:00 Training: Parallelization, optimization¶

13:00 → 14:10 Lunch

14:10 → 17:10 Training: Advanced modules¶