Showing 1–8 of 8 results for author: Cayzac, W

Microcoulomb-level electron beam and multi-Joule hard X-rays driven by a high-efficiency laser-plasma accelerator

Authors: B. Mahieu, L. Ribotte, W. Cayzac, G. Boutoux, R. Parreault, J. Gastineau, E. Lamoine, F. Audo, R. Babjak, D. Batani, N. Blanchot, J. L. Bourgade, M. Brochier, T. Caillaud, P. Canel, S. Cavaro, C. Chappuis, S. Debesset, R. Diaz, E. D Humieres, W. Duchastenier, R. du Jeu, A. Duval, B. Etchessahar, M. Ferri , et al. (16 additional authors not shown)

Abstract: We report on the production of ultrahigh-charge relativistic electron beams and the development of a laser-wakefield acceleration platform at the LMJ facility. Making use of the kilojoule-class, sub-picosecond PETAL laser pulse focused onto a supersonic helium gas jet, electron beams carrying a total charge beyond 1 $μ$C were generated, with energies up to $\sim$500 MeV. Given the ps-scale laser p… ▽ More We report on the production of ultrahigh-charge relativistic electron beams and the development of a laser-wakefield acceleration platform at the LMJ facility. Making use of the kilojoule-class, sub-picosecond PETAL laser pulse focused onto a supersonic helium gas jet, electron beams carrying a total charge beyond 1 $μ$C were generated, with energies up to $\sim$500 MeV. Given the ps-scale laser pulse duration, an on-target intensity approaching $10^{19}~\mathrm{W/cm^2}$, and a plasma density reaching 2% of the critical density, electron energisation arises from a combination of self-modulated laser wakefield acceleration (SMLWFA) and direct laser acceleration (DLA). The resulting electron spectrum exhibits a Maxwellian-like distribution, characteristic of this mixed SMLWFA/DLA regime. The total energy carried by the electron beam is estimated to be up to 17 J, within a sub-ps duration. A broadband Joule-level photon beam was also produced by Bremsstrahlung, demonstrating the potential for future applications. Experimental results are supported by start-to-end numerical simulations, including 3-D particle-in-cell and Monte-Carlo particle transport calculations. These findings pave the way for applications requiring high-charge electron beams, including the generation of high-power secondary radiation or particle sources. The use of these beams to probe matter in high-energy density states driven by the nanosecond-duration LMJ beams represents another promising avenue. △ Less

Submitted 18 August, 2026; v1 submitted 17 August, 2026; originally announced August 2026.

Weibel-mediated filamentary structures observed in the ICF context

Authors: C. Ruyer, S. Bolaños, P. E. Masson Laborde, L. Gremillet, N. Blanchot, G. Boutoux, W. Cayzac, C. Courtois, S. G. Dannhoff, V. Denis, L. Le Deroff, C. K. Li, J. Fuchs, A. Grisollet, I. Lantuéjoul, R. Riquier, R. Smets, G. D. Sutcliffe, B. Vauzour

Abstract: In light of novel and past experimental results, we demonstrate how Weibel-mediated filamentary structures can develop in the expanding plasma plume of a laser-irradiated foil. The transverse ballistic cooling that occurs during the quasi-spherical plasma expansion naturally drives an electron pressure anisotropy, resulting in the growth of electron current filaments. This effect competes with ele… ▽ More In light of novel and past experimental results, we demonstrate how Weibel-mediated filamentary structures can develop in the expanding plasma plume of a laser-irradiated foil. The transverse ballistic cooling that occurs during the quasi-spherical plasma expansion naturally drives an electron pressure anisotropy, resulting in the growth of electron current filaments. This effect competes with electron-ion Coulomb collisions which tend to isotropize the electron distribution function. Based on theoretical and particle-in-cell modeling, we provide estimates of the dominant wavelength and amplitude of the self-generated magnetic fluctuations, which are found to explain experimental data obtained at the OMEGA and Laser Megajoule facilities. △ Less

Submitted 11 May, 2026; originally announced May 2026.

Comments: Accepted for publication in Physics of Plasmas

Numerical modeling of isochoric heating experiments using the TROLL code in the warm dense matter regime

Authors: Sébastien Rassou, Marie Bonneau, Christophe Rousseaux, Xavier Vaisseau, Witold Cayzac, Adrien Denoeud, Frédéric Perez, Tom Beaumont, Morris Demoulins, Jean-Christophe Pain

Abstract: Experiments of isochoric heating by protons of solid material were recently performed at LULI laser facilities. In these experiments, protons, produced from target normal sheath acceleration (TNSA) of Au foil with the PICO2000 laser, deposit their energy into an aluminum or copper foil initially at room temperature and solid density. The heated material reaches the warm dense matter regime with te… ▽ More Experiments of isochoric heating by protons of solid material were recently performed at LULI laser facilities. In these experiments, protons, produced from target normal sheath acceleration (TNSA) of Au foil with the PICO2000 laser, deposit their energy into an aluminum or copper foil initially at room temperature and solid density. The heated material reaches the warm dense matter regime with temperature in the rear face of the material between 1 and 5 eV. The temperature is inferred by streaked optical pyrometry and the proton beam is characterized by Thomson parabola. The high-energy protons produced by TNSA are modeled to deduce the initial proton distribution before the slowing down in the target. Hydrodynamic radiative simulations were next performed using the TROLL code in multidimensional geometry. In the TROLL code, the heating of protons is modeled with a Monte-Carlo transport module of charged particle and the calculation of the energy deposited by the protons in the matter is performed using stopping power formulas like SRIM functions. The results of simulations with the TROLL code are compared with the experimental results. An acceptable agreement between experiment and simulation is found for the temperature at the rear of the material using SESAME equation of state and SRIM stopping power for protons in aluminum. △ Less

Submitted 10 June, 2025; originally announced June 2025.

Comments: submitted to "Contributions to Plasma Physics"

Roadmap for warm dense matter physics

Authors: Jan Vorberger, Frank Graziani, David Riley, Andrew D. Baczewski, Isabelle Baraffe, Mandy Bethkenhagen, Simon Blouin, Maximilian P. Böhme, Michael Bonitz, Michael Bussmann, Alexis Casner, Witold Cayzac, Peter Celliers, Gilles Chabrier, Nicolas Chamel, Dave Chapman, Mohan Chen, Jean Clérouin, Gilbert Collins, Federica Coppari, Tilo Döppner, Tobias Dornheim, Luke B. Fletcher, Dirk O. Gericke, Siegfried Glenzer , et al. (49 additional authors not shown)

Abstract: This roadmap presents the state-of-the-art, current challenges and near future developments anticipated in the thriving field of warm dense matter physics. Originating from strongly coupled plasma physics, high pressure physics and high energy density science, the warm dense matter physics community has recently taken a giant leap forward. This is due to spectacular developments in laser technolog… ▽ More This roadmap presents the state-of-the-art, current challenges and near future developments anticipated in the thriving field of warm dense matter physics. Originating from strongly coupled plasma physics, high pressure physics and high energy density science, the warm dense matter physics community has recently taken a giant leap forward. This is due to spectacular developments in laser technology, diagnostic capabilities, and computer simulation techniques. Only in the last decade has it become possible to perform accurate enough simulations \& experiments to truly verify theoretical results as well as to reliably design experiments based on predictions. Consequently, this roadmap discusses recent developments and contemporary challenges that are faced by theoretical methods, and experimental techniques needed to create and diagnose warm dense matter. A large part of this roadmap is dedicated to specific warm dense matter systems and applications in astrophysics, inertial confinement fusion and novel material synthesis. △ Less

Submitted 13 February, 2026; v1 submitted 5 May, 2025; originally announced May 2025.

Experimental mitigation of fast magnetic reconnection in multiple interacting laser-produced plasmas

Authors: S. Bolaños, R. Smets, C. Courtois, N. Blanchot, G. Boutoux, W. Cayzac, S. N. Chen, V. Denis, A. Grisollet, I. Lantuejoul, L. Le Deroff, R. Riquier, B. Vauzour, J. Fuchs

Abstract: The meeting of astrophysical plasmas and their magnetic fields creates many reconnection sites. We experimentally compare the reconnection rate of laser-driven magnetic reconnection when it takes place at a single site and multiple sites. For a single site, where the ram pressure dominates the magnetic pressure, the measured reconnection rate exceeds the well-established rate of 0.1. However, in t… ▽ More The meeting of astrophysical plasmas and their magnetic fields creates many reconnection sites. We experimentally compare the reconnection rate of laser-driven magnetic reconnection when it takes place at a single site and multiple sites. For a single site, where the ram pressure dominates the magnetic pressure, the measured reconnection rate exceeds the well-established rate of 0.1. However, in the case of multiple close-by sites, we observed a reduction of the reconnection rate. Hybrid-PIC simulations support this observation and suggest that the distortion of the Hall field as well as the concomitant obstruction of one of the outflows are detrimental to the magnetic reconnection rate. △ Less

Submitted 9 May, 2023; originally announced May 2023.

Numerical investigation of spallation neutrons generated from petawatt-scale laser-driven proton beams

Authors: B. Martinez, S. N. Chen, S. Bolaños, N. Blanchot, G. Boutoux, W. Cayzac, C. Courtois, X. Davoine, A. Duval, V. Horny, I. Lantuejoul, L. Le Deroff, P. E. Masson-Laborde, G. Sary, B. Vauzour, R. Smets, L. Gremillet, J. Fuchs

Abstract: Due to their high cost of acquisition and operation, there are still a limited number of high-yield, high-flux neutron source facilities worldwide. In this context, laser-driven neutron sources offer a promising, cheaper alternative to those based on large-scale accelerators, with, in addition, the potential of generating compact neutron beams of high brightness and ultra-short duration. In partic… ▽ More Due to their high cost of acquisition and operation, there are still a limited number of high-yield, high-flux neutron source facilities worldwide. In this context, laser-driven neutron sources offer a promising, cheaper alternative to those based on large-scale accelerators, with, in addition, the potential of generating compact neutron beams of high brightness and ultra-short duration. In particular, the predicted capability of next-generation petawatt (PW)-class lasers to accelerate protons beyond the 100 MeV range should unlock efficient neutron generation through spallation reactions. In this paper, this scenario is investigated numerically through particle-in-cell and Monte Carlo simulations, modeling, respectively, the laser acceleration of protons from thin-foil targets and their subsequent conversion into neutrons in secondary heavy-ion targets. Laser parameters relevant to the 1 PW LMJ-PETAL and 1-10 PW Apollon systems are considered. Under such conditions, neutron fluxes exceeding $10^{23}\,\rm n\,cm^{-2}\,s^{-1}$ are predicted, opening up attractive fundamental and applicative prospects. △ Less

Submitted 22 June, 2021; v1 submitted 24 May, 2021; originally announced May 2021.

Comments: 16 pages, 13 figures

A quasi-monoenergetic short time duration compact proton source for probing high energy density states of matter

Authors: J. I. Apiñaniz, S. Malko, R. Fedosejevs, W. Cayzac, X. Vaisseau, D. de Luis, G. Gatti, C. McGuffey, M. Bailly-Grandvaux, K. Bhutwala, V. Ospina-Bohorquez, J. Balboa, J. J. Santos, D. Batani, F. Beg, L. Roso, J. A. Perez-Hernandez, L. Volpe

Abstract: We report on the development of a highly directional, narrow energy band, short time duration proton beam operating at high repetition rate, suitable for measurements of stopping power in high energy density plasmas as well as other applications. The protons are generated with an ultrashort-pulse laser interacting with a solid target and converted to a pencil-like narrow-band beam using a compact… ▽ More We report on the development of a highly directional, narrow energy band, short time duration proton beam operating at high repetition rate, suitable for measurements of stopping power in high energy density plasmas as well as other applications. The protons are generated with an ultrashort-pulse laser interacting with a solid target and converted to a pencil-like narrow-band beam using a compact magnet-based energy selector. We experimentally demonstrate the production of a proton beam with an energy of 500 keV and energy spread well below 10%, and a pulse duration of 260 ps. The energy loss of this beam is measured in a 2 $μ$m thick solid Mylar target and found to be in within 1% of theoretical predictions. The short time duration of the proton pulse makes it particularly well suited for applications involving the probing of highly transient plasma states produced in laser-matter interaction experiments, in particular measurements of proton stopping power. △ Less

Submitted 27 November, 2020; originally announced November 2020.

Effects of alpha stopping power modelling on the ignition threshold in a directly-driven Inertial Confinement Fusion capsule

Authors: Mauro Temporal, Benoit Canaud, Withold Cayzac, Rafael Ramis, Robert L. Singleton Jr

Abstract: The alpha-particle energy deposition mechanism modifies the ignition conditions of the thermonuclear Deuterium-Tritium fusion reactions, and constitutes a key issue in achieving high gain in Inertial Confinement Fusion implosions. One-dimensional hydrodynamic calculations have been performed with the code Multi-IFE [R. Ramis and J. Meyer-ter-Vehn, Comp. Phys. Comm. 203, 226 (2016)] to simulate the… ▽ More The alpha-particle energy deposition mechanism modifies the ignition conditions of the thermonuclear Deuterium-Tritium fusion reactions, and constitutes a key issue in achieving high gain in Inertial Confinement Fusion implosions. One-dimensional hydrodynamic calculations have been performed with the code Multi-IFE [R. Ramis and J. Meyer-ter-Vehn, Comp. Phys. Comm. 203, 226 (2016)] to simulate the implosion of a capsule directly irradiated by a laser beam. The diffusion approximation for the alpha energy deposition has been used to optimize three laser profiles corresponding to different implosion velocities. A Monte-Carlo package has been included in Multi-IFE to calculate the alpha energy transport, and in this case the energy deposition uses both the LP [C.K. Li and R.D. Petrasso, Phys. Rev. Lett. 70, 3059 (1993)] and the BPS [L.S. Brown, D.L. Preston, and R.L. Singleton Jr., Phys. Rep. 410, 237 (2005)] stopping power models. Homothetic transformations that maintain a constant implosion velocity have been used to map out the transition region between marginally-igniting and high-gain configurations. The results provided by the two models have been compared and it is found that - close to the ignition threshold - in order to produce the same fusion energy, the calculations performed with the BPS model require about 10% more invested energy with respect to the LP model. △ Less

Submitted 24 February, 2017; originally announced February 2017.

Comments: 6 pages, 6 figures

Report number: LA-UR-17-20568