Publications

2023

• Far field energy distribution control using a coherent beam combining femtosecond digital laser
  
  • Fsaifes Ihsan
  • Ranély-Vergé-Dépré Claude-Alban
  • Veinhard Matthieu
  • Bellanger Séverine
  • Chanteloup Jean-Christophe
  Optics Express, Optical Society of America - OSA Publishing, 2023, 31 (5), pp.8217-8225. We report on far field energy distribution control using a coherent beam combining femtosecond digital laser employing 61 tiled channels. Each channel is considered as an individual pixel where amplitude and phase are controlled independently. Applying a phase difference between neighboring fibers or neighboring fiber-lines gives high agility for far field energy distribution and paves the way for deeper exploration of phase patterns as a tool to further improve tiled-aperture CBC laser efficiency and far field shaping on demand. (10.1364/oe.474607)
  DOI : 10.1364/oe.474607
• Numerical investigation of non-linear inverse Compton scattering in double-layer targets
  
  • Galbiati Marta
  • Formenti Arianna
  • Grech Mickael
  • Passoni Matteo
  Frontiers in Physics, Frontiers, 2023, 11, pp.1117543. Non-linear inverse Compton scattering (NICS) is of significance in laser-plasma physics and for application-relevant laser-driven photon sources. Given this interest, we investigated this synchrotron-like photon emission in a promising configuration achieved when an ultra-intense laser pulse interacts with a double-layer target (DLT). Numerical simulations with two-dimensional particle-in-cell codes and analytical estimates are used for this purpose. The properties of NICS are shown to be governed by the processes characterizing laser interaction with the near-critical and solid layers composing the DLT. In particular, electron acceleration, laser focusing in the low-density layer, and pulse reflection on the solid layer determine the radiated power, the emitted spectrum, and the angular properties of emitted photons. Analytical estimates, supported by simulations, show that quantum effects are relevant at laser intensities as small as ∼ 10$^{21}$ W/cm$^2$ Target and laser parameters affect the NICS competition with bremsstrahlung and the conversion efficiency and average energy of emitted photons. Therefore, DLT properties could be exploited to tune and enhance photon emission in experiments and future applications. (10.3389/fphy.2023.1117543)
  DOI : 10.3389/fphy.2023.1117543
• Measuring the principal Hugoniot of inertial-confinement-fusion-relevant TMPTA plastic foams
  
  • Paddock R.
  • von der Leyen M.
  • Aboushelbaya R.
  • Norreys P.
  • Chapman D.
  • Eakins D.
  • Oliver M.
  • Clarke R.
  • Notley M.
  • Baird C.
  • Booth N.
  • Spindloe C.
  • Haddock D.
  • Irving S.
  • Scott R.
  • Pasley J.
  • Cipriani M.
  • Consoli F.
  • Albertazzi Bruno
  • Koenig M.
  • Martynenko A.
  • Wegert L.
  • Neumayer P.
  • Tchórz P.
  • Rączka P.
  • Mabey P.
  • Garbett W.
  • Goshadze R. M. N.
  • Karasiev V.
  • Hu S. X.
  Physical Review E, American Physical Society (APS), 2023, 107 (2), pp.025206. Wetted-foam layers are of significant interest for inertial-confinement-fusion capsules, due to the control they provide over the convergence ratio of the implosion and the opportunity this affords to minimize hydrodynamic instability growth. However, the equation of state for fusion-relevant foams are not well characterized, and many simulations rely on modeling such foams as a homogeneous medium with the foam average density. To address this issue, an experiment was performed using the VULCAN Nd:glass laser at the Central Laser Facility. The aim was to measure the principal Hugoniot of TMPTA plastic foams at 260 mg/cm$^3$, corresponding to the density of liquid DT-wetted-foam layers, and their “hydrodynamic equivalent” capsules. A VISAR was used to obtain the shock velocity of both the foam and an $\alpha$-quartz reference layer, while streaked optical pyrometry provided the temperature of the shocked material. The measurements confirm that, for the 20–120 GPa pressure range accessed, this material can indeed be well described using the equation of state of the homogeneous medium at the foam density. (10.1103/PhysRevE.107.025206)
  DOI : 10.1103/PhysRevE.107.025206
• Pair creation in extreme light‎ : highlights on vortex laser beam
  
  • Mercuri-Baron Anthony
  , 2023. Since the invention of the Chirped Pulse Amplification technique, achievable laser intensities never stopped increasing. The upcoming facilities are expected to deliver several PW peak power on a focal spot of a few microns diameter. When particles interact with those extreme electromagnetic fields, nonlinear effects of a quantum nature can be dominant, described by the so-called strong-field quantum electrodynamics (SFQED). Among the prediction of SFQED two phenomena in particular attracted the interest of the community over the last decade. The first one, the nonlinear Compton scattering process, is the emission of a high energy gamma photon (from a hundred of MeV to tens of GeV) by an electron or a positron interacting with a strong background field. The second one is the nonlinear Breit-Wheeler (NBW) process, that consists in the creation of an electron-positron pair from the conversion of a high energy gamma photon interacting with the strong electromagnetic field. Thanks to this processes, multi-PW laser facilities open the way to prolific electron-positron pair production in the laboratory. The ultimate goal, although not yet achievable in current facilities, is the creation of an electron-positron pair plasma in the laboratory. This kind of plasma is of interest from a fundamental point of view for its exotic properties, but also because it is present in the astrophysical environment. The common thread in this thesis is the optimisation of pair creation in ultra intense lasers, for which two promising physical configurations achievable in the future were studied. The first one, in the so-called shower-regime, involves the head-on collision of a high intensity laser pulse with a flash of high energy gamma photons. A semi-analytical model was developed for this configuration that takes fully into account the laser pulse spatio-temporal distribution and allows to predict quickly the amount of produced pairs. The model prediction was in excellent agreement with three dimensional Particle-in-cell (PIC) simulations performed with the code SMILEI. A systematic study for different laser pulse configurations was performed, by considering a fixed total pulse energy, to match experimental conditions. In this study Laguerre-Gauss (LG) beams, or vortex beams, were also considered because of their interesting properties, such as a ring shape transverse intensity distribution, and the fact that they carry orbital angular momentum. The study allowed to identify the optimal focalisation in order to maximise pair production that, depending on the total energy available, is not necessarily the tightest focus. General guidelines for upcoming experiments were also provided. The second configuration studied involves two counter streaming laser beams, with seeding electrons in the focal plane. With this set-up an exponential growth (avalanche) of the pairs’ number can be obtained, as charges are constantly reaccelerated and emit gamma photons, further converted into pairs. The present work re-examined the conditions for the inset of the avalanche in a realistic 3D geometry for the laser pulse, and extended the study to LG beams. We studied semi-analytically the short time (less than a laser period) particle dynamics in the counter streaming lasers and showed that there are large qualitative differences in the onset of the cascade depending on the field configuration. The growth rate of pair production was derived from 3D PIC simulations and confirmed the qualitative differences. Moreover we showed that -at the same peak intensity- LG beams can have larger growth rates than Gaussian beams. The analysis of the short time particle dynamics allowed to propose a new model to predict the growth rate of the avalanche for an idealised configuration, with the perspective of an extension to a more realistic 3D counter-streaming beams configuration. (10.70675/3e504cc3zc366z4f93z9407z5a37d6d5ed9b)
  DOI : 10.70675/3e504cc3zc366z4f93z9407z5a37d6d5ed9b
• Cellular irradiations with laser-driven carbon ions at ultra-high dose rates
  
  • Chaudhary Pankaj
  • Milluzzo Giuliana
  • Mcilvenny Aodhan
  • Ahmed Hamad
  • Mcmurray Aaron
  • Maiorino Carla
  • Polin Kathryn
  • Romagnani Lorenzo
  • Doria Domenico
  • Mcmahon Stephen J
  • Botchway Stanley W
  • Rajeev Pattathil P
  • Prise Kevin M
  • Borghesi Marco
  Physics in Medicine and Biology, IOP Publishing, 2023, 68 (2), pp.025015. Objective. Carbon is an ion species of significant radiobiological interest, particularly in view of its use in cancer radiotherapy, where its large Relative Biological Efficiency is often exploited to overcome radio resistance. A growing interest in highly pulsed carbon delivery has arisen in the context of the development of the FLASH radiotherapy approach, with recent studies carried out at dose rates of 40 Gy s$^{−1}$ . Laser acceleration methods, producing ultrashort ion bursts, can now enable the delivery of Gy-level doses of carbon ions at ultra-high dose rates (UHDRs), exceeding 10$^9$ Gy s$^{−1}$ . While studies at such extreme dose rate have been carried out so far using low LET particles such as electrons and protons, the radiobiology of high-LET, UHDR ions has not yet been explored. Here, we report the first application of laser-accelerated carbon ions generated by focussing 10$^{20}$ W cm$^{−2}$ intense lasers on 10–25 nm carbon targets, to irradiate radioresistant patient-derived Glioblastoma stem like cells (GSCs). Approach. We exposed GSCs to 1 Gy of 9.5 ± 0.5 MeV/n carbon ions delivered in a single ultra-short (∼400-picosecond) pulse, at a dose rate of 2 × 10$^9$ Gy s$^{−1}$ , generated using the ASTRA GEMINI laser of the Central Laser Facility at the Rutherford Appleton Laboratory, Didcot, Oxfordshire, UK. We quantified carbon ion-induced DNA double strand break (DSB) damage using the 53BP1 foci formation assay and used 225 kVp x-rays as a reference radiation. Main Results. Laser-accelerated carbon ions induced complex DNA DSB damage, as seen through persistent 53BP1 foci (11.5 ± 0.4 foci/cell/Gy) at 24 h and significantly larger foci (1.69 ± 0.07 μm$^2$ ) than x-rays induced ones (0.63 ± 0.02 μm$^2$ ). The relative foci induction value for laser-driven carbon ions relative to conventional x-rays was 3.2 ± 0.3 at 24 h post-irradiation also confirming the complex nature of the induced damage. Significance. Our study demonstrates the feasibility of radiobiology investigations at unprecedented dose rates using laser-accelerated high-LET carbon ions in clinically relevant models. (10.1088/1361-6560/aca387)
  DOI : 10.1088/1361-6560/aca387
• Investigating particle acceleration dynamics in interpenetrating magnetized collisionless super-critical shocks
  
  • Yao Weipeng
  • Fazzini A.
  • Chen S.N.
  • Burdonov K.
  • Béard J.
  • Borghesi M.
  • Ciardi A.
  • Miceli M.
  • Orlando S.
  • Ribeyre X.
  • d'Humières E.
  • Fuchs J.
  Journal of Plasma Physics, Cambridge University Press (CUP), 2023, 89 (1), pp.915890101. Colliding collisionless shocks appear in a great variety of astrophysical phenomena and are thought to be possible sources of particle acceleration in the Universe. We have previously investigated particle acceleration induced by single super-critical shocks (whose magnetosonic Mach number is higher than the critical value of 2.7) (Yao et al. , Nat. Phys. , vol. 17, issue 10, 2021, pp. 1177–1182; Yao et al. , Matter Radiat. Extrem. , vol. 7, issue 1, 2022, 014402), as well as the collision of two sub-critical shocks (Fazzini et al. , Astron. Astrophys. , vol. 665, 2022, A87). Here, we propose to make measurements of accelerated particles from interpenetrating super-critical shocks to observe the ‘phase-locking effect’ (Fazzini et al. , Astron. Astrophys. , vol. 665, 2022, A87) from such an event. This effect is predicted to significantly boost the energy spectrum of the energized ions compared with a single super-critical collisionless shock. We thus anticipate that the results obtained in the proposed experiment could have a significant impact on our understanding of one type of primary source (acceleration of thermal ions as opposed to secondary acceleration mechanisms of already energetic ions) of ion energization of particles in the Universe. (10.1017/S002237782300003X)
  DOI : 10.1017/S002237782300003X
• Absolute calibration up to 20 MeV of an online readout CMOS system suitable to detect high-power lasers accelerated protons
  
  • Burdonov K
  • Lelièvre R
  • Forestier-Colleoni P
  • Ceccotti T
  • Cuciuc M
  • Lancia L
  • Yao W
  • Fuchs J
  Review of Scientific Instruments, American Institute of Physics, 2023, 94 (8), pp.083303. We present the design and absolute calibration of a charged particle online readout CMOS system tailored for high-power laser experiments. This system equips a Thomson parabola spectrometer, which is used at the Apollon petawatt scale laser facility to measure the spectra of protons produced by high-intensity laser–target interactions. The RadEye1 CMOS matrices array detectors are paired with a custom triggering system for image grabbing. This allows us to register the proton and ion signals remotely. The repetition rate is presently 1 shot/min, but the frame grabbing enables the system to be compatible with modern high-power lasers running, e.g., at 1 Hz. We detail here the implementation, in the harsh electromagnetic environment of such interactions, of the system, and its absolute calibration, which was performed for proton energies from 4 to 20 MeV. (10.1063/5.0150373)
  DOI : 10.1063/5.0150373
• Experimental characterisation of a single-shot spectrometer for high-flux, GeV-scale gamma-ray beams
  
  • Cavanagh N
  • Fleck K
  • Streeter M.J.V
  • Gerstmayr E
  • Dickson L. T.
  • Ballage C
  • Cadas R
  • Calvin L
  • Dufrénoy S. Dobosz
  • Moulanier I.
  • Romagnani L
  • Vasilovici Ovidiu
  • Whitehead A
  • Specka A
  • Cros B.
  • Sarri G
  Physical Review Research, American Physical Society, 2023, 5 (4), pp.043046. We report on the first experimental characterisation of a gamma-ray spectrometer designed to spectrally resolve high-flux photon beams with energies in the GeV range. The spectrometer has been experimentally characterised using a bremsstrahlung source obtained at the Apollon laser facility during the interaction of laser-wakefield accelerated electron beams (maximum energy of 1.7 GeV and overall charge of 207$\pm$62 pC) with a 1 mm thick tantalum target. Experimental data confirms the possibility of performing single-shot measurements, without the need for accumulation, with a high signal to noise ratio. Scaling the results to photons in the multi-GeV range suggests the possibility of achieving percent-level energy resolution, as required, for instance, by the next generation of experiments in strong-field quantum electrodynamics. (10.1103/PhysRevResearch.5.043046)
  DOI : 10.1103/PhysRevResearch.5.043046
• Zr-based metallic glasses Hugoniot under laser shock compression and spall strength evolution with the strain rate >10$^7$ s$^{-1}$)
  
  • Raffray Yoann
  • Jodar Benjamin
  • Sangleboeuf Jean-Christophe
  • Benuzzi-Mounaix Alessandra
  • Vinci Tommaso
  • Berthe Laurent
  • Lescoute Emilien
  • Barraud Étienne
  • Brambrink Erik
  • Daudin Rémi
  • Blandin Jean-Jacques
  • Loison Didier
  International Journal of Impact Engineering, Elsevier, 2023, 181, pp.104755. We investigate the mechanical response of Zr$_{50}$Cu$_{40}$Al$_{10}$ and Zr$_{60}$Cu$_{30}$Al$_{10}$ metallic glasses under laser shock compression to reproduce hypervelocity impact conditions such as high longitudinal stresses and high strain rates in an unknown range of 10$^6$−10$^7$s$^{−1}$. Hugoniot curves and strength parameters (spall strength and strain rate) are obtained from free surface velocity profiles and compared with previous studies on the mechanical behaviour of Zr-based metallic glasses under plate impact experiments. We established Hugoniot curves for both compositions up to 100 GPa, corresponding to a particle velocity of 1.8 km/s, and consistent with literature up to 75 GPa. Concerning the strength parameters, we studied the evolution of the spall strength with the strain rate and obtained data unreached up to now from 1.7×10$^6$s$^{−1}$ to 2.7×10$^7$s$^{−1}$. This range of data correspond to strain rates of hypervelocity impacts of small debris (≈0.1−1mm) on space infrastructure shields. Moreover, we highlight a strong dependency of the spall strength with the strain rate starting from 2×10$^6$s$^{−1}$. Indeed, the spall strength increases from 2.6 GPa, close to its quasi-static tensile strength value, up to 13.6 GPa. (10.1016/j.ijimpeng.2023.104755)
  DOI : 10.1016/j.ijimpeng.2023.104755
• Coherent subcycle optical shock from superluminal plasma wake
  
  • Peng H.
  • Huang T.W.
  • Jiang K.
  • Li R.
  • Wu C.N.
  • Yu M.Y.
  • Riconda C.
  • Weber S.
  • Zhou C.T.
  • Ruan S.C.
  Physical Review Letters, American Physical Society, 2023, 131 (14), pp.145003. We propose a new mechanism for generating coherent subcycle optical pulse by directing a relativistic electron beam (REB) into a plasma with a density up-ramp. The subcycle pulse is coherently emitted by bubble-sheath electrons in REB-induced superluminal plasma wake. Using three-dimensional particle-in-cell and far-field time-domain radiation simulations as well as analytical modeling, we show that an isolated subcycle optical shock can be produced at the Cherenkov angle. This radiation has ultra-short attosecond-scale duration and high intensity and exhibits excellent directionality with ultra-low angular divergence and stable carrier envelope phase. Its central frequency can be easily tuned over a wide range, from the far-infrared to the ultra-violet, by adjusting the plasma and driver-beam density. (10.1103/PhysRevLett.131.145003)
  DOI : 10.1103/PhysRevLett.131.145003
• Short-term evolution of electron wave packet in a constant crossed field with radiative corrections
  
  • Kostyukov I.Yu
  • Nerush E.N
  • Mironov A.A
  • Fedotov A.M
  Phys.Rev.D, 2023, 108 (9), pp.093007. We study the dynamics of an electron wave packet in a strong constant crossed electromagnetic field with account for radiative corrections due to interaction of the electron with the vacuum fluctuations. We evaluate a wave packet composed of the solutions to the Dyson-Schwinger equation, which describes electron propagation without emission of real photons. Spacetime dependence of the wave packet is obtained analytically for a short time interval, the more restricted from above the wider is the packet in momentum space. The radiative corrections alter the electron wavefunction, resulting in particular in a damping of the wave packet. The expectation value of the Dirac spin operator also gets modified. (10.1103/PhysRevD.108.093007)
  DOI : 10.1103/PhysRevD.108.093007
• Proton and helium ions acceleration in near-critical density gas targets by short-pulse Ti:Sa PW-class laser
  
  • Henares J.L
  • Puyuelo-Valdes P
  • Salgado-López C
  • Apiñaniz J.I
  • Bradford P
  • Consoli F
  • de Luis D
  • Ehret M
  • Hannachi F
  • Hernández-Martín R
  • Huber A
  • Lancia L
  • Mackeviciute M
  • Maitrallain A
  • Marquès J.-R
  • Pérez-Hernández J.A
  • Santos C
  • Santos J.J
  • Stankevic V
  • Tarisien M
  • Tomkus V
  • Volpe L
  • Gatti G
  Journal of Plasma Physics, Cambridge University Press (CUP), 2023, 89 (6), pp.965890601. <p>The ability to quickly refresh gas-jet targets without cycling the vacuum chamber makes them a promising candidate for laser-accelerated ion experiments at high repetition rate. Here we present results from the first high repetition rate ion acceleration experiment on the VEGA-3 PW-class laser at CLPU. A near-critical density gas-jet target was produced by forcing a 1000 bar H$_2$ and He gas mix through bespoke supersonic shock nozzles. Proton energies up to 2 MeV were measured in the laser forward direction and 2.2 MeV transversally. He $^{2+}$ ions up to 5.8 MeV were also measured in the transverse direction. To help maintain a consistent gas density profile over many shots, nozzles were designed to produce a high-density shock at distances larger than 1 mm from the nozzle exit. We outline a procedure for optimizing the laser–gas interaction by translating the nozzle along the laser axis and using different nozzle materials. Several tens of laser interactions were performed with the same nozzle which demonstrates the potential usefulness of gas-jet targets as high repetition rate particle source.</p> (10.1017/S0022377823001332)
  DOI : 10.1017/S0022377823001332
• Ultrafast x-ray detection of low-spin iron in molten silicate under deep planetary interior conditions
  
  • Shim Sang-Heon
  • Ko Byeongkwan
  • Sokaras Dimosthenis
  • Nagler Bob
  • Lee He Ja
  • Galtier Eric
  • Glenzer Siegfried
  • Granados Eduardo
  • Vinci Tommaso
  • Fiquet Guillaume
  • Dolinschi Jonathan
  • Tappan Jackie
  • Kulka Britany
  • Mao Wendy
  • Morard Guillaume
  • Ravasio Alessandra
  • Gleason Arianna
  • Alonso-Mori Roberto
  Science Advances, American Association for the Advancement of Science (AAAS), 2023, 9 (42), pp.eadi6153. The spin state of Fe can alter the key physical properties of silicate melts, affecting the early differentiation and the dynamic stability of the melts in the deep rocky planets. The low-spin state of Fe can increase the affinity of Fe for the melt over the solid phases and the electrical conductivity of melt at high pressures. However, the spin state of Fe has never been measured in dense silicate melts due to experimental challenges. We report detection of dominantly low-spin Fe in dynamically compressed olivine melt at 150 to 256 gigapascals and 3000 to 6000 kelvin using laser-driven shock wave compression combined with femtosecond x-ray diffraction and x-ray emission spectroscopy using an x-ray free electron laser. The observation of dominantly low-spin Fe supports gravitationally stable melt in the deep mantle and generation of a dynamo from the silicate melt portion of rocky planets. (10.1126/sciadv.adi6153)
  DOI : 10.1126/sciadv.adi6153
• Electron acceleration by laser plasma wedge interaction
  
  • Marini S.
  • Kleij P.S.
  • Grech M.
  • Raynaud M.
  • Riconda C.
  Physical Review Research, American Physical Society, 2023, 5 (1), pp.013115. A new electron acceleration mechanism is identified that develops when a relativistically intense laser irradiates the wedge of an over-dense plasma. This induces a diffracted electromagnetic wave with a significant longitudinal electric field that accelerates electrons from the plasma over long distances to relativistic energies. Well collimated, highly-charged (nC) electron bunches with energies up to 100's MeV are obtained using a laser beam with $I \lambda_0^2 =3.5\times 10^{19}\,{\rm W \mu m^2/cm^2}$. Multi-dimensional particle-in-cell simulations, supported by a simple analytical model, confirm the efficiency and robustness of the proposed acceleration scheme. (10.1103/PhysRevResearch.5.013115)
  DOI : 10.1103/PhysRevResearch.5.013115