Publications

2021

• Numerical investigation of spallation neutrons generated from petawatt-scale laserdriven proton beams
  
  • Soloviev A.
  • Burdonov K.
  • Kotov A.
  • Perevalov S.
  • Zemskov R.
  • Ginzburg V.N.
  • Kochetkov A.
  • Kuzmin A.
  • Shaikin A.
  • Shaikin I.
  • Khazanov E.
  • Yakovlev I.
  • Luchinin A.
  • Morozkin M.V.
  • Proyavin M.
  • Glyavin M.Yu.
  • Fuchs J.
  • Starodubtsev M.V.
  Matter and Radiation at Extremes, AIP Publishing, 2021, 63 (11), pp.876-886. Laser-driven neutron sources could offer a promising alternative to those based on conventional accelerator technologies in delivering compact beams of high brightness and short duration. We examine this through particle-in-cell and Monte Carlo simulations, that model, respectively, the laser acceleration of protons from thin-foil targets and their subsequent conversion into neutrons in secondary lead targets. Laser parameters relevant to the 0.5 petawatt (PW) LMJ-PETAL and 0.6-6 PW Apollon systems are considered. Due to its high intensity, the 20-fs-duration 0.6 PW Apollon laser is expected to accelerate protons up to above 100 MeV, thereby unlocking efficient neutron generation via spallation reactions. As a result, despite a 30-fold lower pulse energy than the LMJ-PETAL laser, the 0.6 PW Apollon laser should perform comparably well both in terms of neutron yield and flux. Notably, we predict that very compact neutron sources, of ~ 10 ps duration and ~ 100 µm spot size, can be released provided the lead convertor target is thin enough (~ 100 µm). These sources are characterized by extreme fluxes, of the order of 10 23 n cm-2 s-1 , and even ten times higher when using the 6 PW Apollon laser. Such values surpass those currently achievable at large-scale accelerator-based neutron sources (~ 10 16 n cm-2 s-1), or reported from previous laser experiments using low-Z converters (~ 10 18 n cm-2 s-1). By showing that such laser systems can produce neutron pulses significantly brighter than existing sources, our findings open a path towards attractive novel applications, such as flash neutron radiography or laboratory studies of heavy-ion nucleosynthesis. (10.1007/s11141-021-10101-y)
  DOI : 10.1007/s11141-021-10101-y
• Pulsed magnetic field generation system for laser-plasma research
  
  • Luchinin A G
  • Malyshev V A
  • Kopelovich E A
  • Burdonov K F
  • Gushchin M E
  • Morozkin M V
  • Proyavin M D
  • Rozental R M
  • Soloviev A A
  • Starodubtsev M V
  • Fokin A P
  • Fuchs Julien
  • Glyavin M. Yu.
  Review of Scientific Instruments, American Institute of Physics, 2021, 92 (12), pp.123506. An up to 15 T pulsed magnetic field generator in a volume of a few cubic centimeters has been developed for experiments with magnetized laser plasma. The magnetic field is created by a pair of coils placed in a sealed reservoir with liquid nitrogen, installed in a vacuum chamber with a laser target. The bearing body provides the mechanical strength of the system both in the case of co-directional and oppositely connected coils. The configuration of the housing allows laser radiation to be introduced into the working area between the coils in a wide range of directions and focusing angles, place targets away from the symmetry axis of the magnetic system, and irradiate several targets simultaneously. (10.1063/5.0035302)
  DOI : 10.1063/5.0035302
• Micron-scale phenomena observed in a turbulent laser-produced plasma
  
  • Rigon G.
  • Albertazzi B.
  • Pikuz T.
  • Mabey P.
  • Bouffetier V.
  • Ozaki N.
  • Vinci T.
  • Barbato F.
  • Falize E.
  • Inubushi Y.
  • Kamimura N.
  • Katagiri K.
  • Makarov S.
  • Manuel M. J.-E.
  • Miyanishi K.
  • Pikuz S.
  • Poujade O.
  • Sueda K.
  • Togashi T.
  • Umeda Y.
  • Yabashi M.
  • Yabuuchi T.
  • Gregori G.
  • Kodama R.
  • Casner A.
  • Koenig M.
  Nature Communications, Nature Publishing Group, 2021, 12 (1). Abstract Turbulence is ubiquitous in the universe and in fluid dynamics. It influences a wide range of high energy density systems, from inertial confinement fusion to astrophysical-object evolution. Understanding this phenomenon is crucial, however, due to limitations in experimental and numerical methods in plasma systems, a complete description of the turbulent spectrum is still lacking. Here, we present the measurement of a turbulent spectrum down to micron scale in a laser-plasma experiment. We use an experimental platform, which couples a high power optical laser, an x-ray free-electron laser and a lithium fluoride crystal, to study the dynamics of a plasma flow with micrometric resolution (~1μm) over a large field of view (>1 mm 2 ). After the evolution of a Rayleigh–Taylor unstable system, we obtain spectra, which are overall consistent with existing turbulent theory, but present unexpected features. This work paves the way towards a better understanding of numerous systems, as it allows the direct comparison of experimental results, theory and numerical simulations. (10.1038/s41467-021-22891-w)
  DOI : 10.1038/s41467-021-22891-w
• i-REAL : Voyage dans les cartographies sensibles
  
  • Veyrat Marc
  • Franck Philippe
  Turbulences Vidéo, 2021 (114), pp.45-55. À partir d’un parcours de plasticien puis d’artiste/ concepteur numérique, Marc Veyrat a développé, au sein de sa structure la Société i Matériel, des projets collaboratifs associant recherche (il est directeur du département Communication Hypermédia de l’Université de Savoie Mont-Blanc et membre du laboratoire CiTu-Paragraphe à l’Université Paris 8) et création « in progress ».
• Characterization and performance of the Apollon short-focal-area facility following its commissioning at 1 PW level
  
  • Burdonov K.
  • Fazzini A.
  • Lelasseux V.
  • Albrecht J.
  • Antici P.
  • Ayoul Y.
  • Beluze A.
  • Cavanna D.
  • Ceccotti T.
  • Chabanis M.
  • Chaleil A.
  • Chen S. N.
  • Chen Z.
  • Consoli F.
  • Cuciuc M.
  • Davoine X.
  • Delaneau J.
  • D’humières E.
  • Dubois J.-L.
  • Evrard C.
  • Filippov E.
  • Freneaux A.
  • Forestier-Colleoni P.
  • Gremillet L.
  • Horny V.
  • Lancia L.
  • Lecherbourg L.
  • Lebas N.
  • Leblanc A.
  • Ma W.
  • Martin L.
  • Negoita F.
  • Paillard J.-L.
  • Papadopoulos D.
  • Perez F.
  • Pikuz S.
  • Qi G.
  • Quéré F.
  • Söderström P.-A.
  • Ranc Lucas
  • Scisciò M.
  • Sun S.
  • Vallières S.
  • Wang P.
  • Yao W.
  • Mathieu F.
  • Audebert P.
  • Fuchs J.
  Matter and Radiation at Extremes, AIP Publishing, 2021, 6 (6), pp.064402. We present the results of the first commissioning phase of the short-focal-length area of the Apollon laser facility (located in Saclay, France), which was performed with the first available laser beam (F2), scaled to a nominal power of 1 PW. Under the conditions that were tested, this beam delivered on-target pulses of 10 J average energy and 24 fs duration. Several diagnostics were fielded to assess the performance of the facility. The on-target focal spot and its spatial stability, the temporal intensity profile prior to the main pulse, and the resulting density gradient formed at the irradiated side of solid targets have been thoroughly characterized, with the goal of helping users design future experiments. Emissions of energetic electrons, ions, and electromagnetic radiation were recorded, showing good laser-to-target coupling efficiency and an overall performance comparable to that of similar international facilities. This will be followed in 2022 by a further commissioning stage at the multi-petawatt level. (10.1063/5.0065138)
  DOI : 10.1063/5.0065138
• Experimental characterization of hot electron emission and shock dynamics in the context of the Shock Ignition Approach to Inertial Confinement Fusion
  
  • Tentori A
  • Colaïtis Arnaud
  • Theobald W.
  • Ruocco A.
  • Trela Jocelain
  • Casner A.
  • Le Bel Edouard
  • D. Raffestin
  • Pikuz S.A. A
  • M. Koenig
  • Henderson B.
  • Baton S. D.
  • Betti R.
  • Anderson K.
  • Wei M.
  • Batani Dimitri
  Physics of Plasmas, American Institute of Physics, 2021, 28, pp.103302. We report on planar target experiments conducted on the OMEGA-EP laser facility performed in the context of the Shock Ignition (SI) approach to inertial confinement fusion. The experiment aimed at characterizing the propagation of strong shock in matter and the generation of hot-electrons (HE), with laser parameters relevant to SI (1-ns UV laser beams with I ∼10 16 W/cm 2). Time-resolved radiographies of targets were performed in order to study the hydrodynamic evolution. The hot-electron source was characterized in terms of maxwellian temperature T h and laser to hot-electron energy conversion efficiency η using data from different x-rays spectrometers. The post-processing of these data gives a range of possible values for T h and η (i.e. T h [keV] ∈ [20,50] and η ∈ [2%,13%]). These values are used as input in hydrodynamic simulations to reproduce the results obtained in radiographies, thus constraining the range for the HE measurements. According to this procedure, we found that the laser converts ∼10% ±4% of energy into hot-electrons with T h = 27 keV ±7 keV. Such electrons have enough low temperature that they should not be a prehaeat concern in SI. (10.1063/5.0059651)
  DOI : 10.1063/5.0059651
• Clinical phenotype and loss of the slow skeletal muscle troponin T in three new patients with recessive TNNT1 nemaline myopathy
  
  • Géraud Justine
  • Dieterich Klaus
  • Rendu John
  • Uro Coste Emmanuelle
  • Dobrzynski Murielle
  • Marcorelle Pascale
  • Ioos Christine
  • Romero Norma Beatriz
  • Baudou Eloise
  • Brocard Julie
  • Coville Anne-Cécile
  • Fauré Julien
  • Koenig Michel
  • Juntas Morales Raul
  • Lacène Emmanuelle
  • Madelaine Angéline
  • Marty Isabelle
  • Pegeot Henri
  • Theze Corinne
  • Siegfried Aurore
  • Cossee Mireille
  • Cances Claude
  Journal of Medical Genetics, BMJ Publishing Group, 2021, 58 (9), pp.602-608. Background Congenital nemaline myopathies are rare pathologies characterised by muscle weakness and rod-shaped inclusions in the muscle fibres. Methods Using next-generation sequencing, we identified three patients with pathogenic variants in the Troponin T type 1 ( TNNT1 ) gene, coding for the troponin T (TNT) skeletal muscle isoform. Results The clinical phenotype was similar in all patients, associating hypotonia, orthopaedic deformities and progressive chronic respiratory failure, leading to early death. The anatomopathological phenotype was characterised by a disproportion in the muscle fibre size, endomysial fibrosis and nemaline rods. Molecular analyses of TNNT1 revealed a homozygous deletion of exons 8 and 9 in patient 1; a heterozygous nonsense mutation in exon 9 and retention of part of intron 4 in muscle transcripts in patient 2; and a homozygous, very early nonsense mutation in patient 3. Western blot analyses confirmed the absence of the TNT protein resulting from these mutations. Discussion The clinical and anatomopathological presentations of our patients reinforce the homogeneous character of the phenotype associated with recessive TNNT1 mutations. Previous studies revealed an impact of recessive variants on the tropomyosin-binding affinity of TNT. We report in our patients a complete loss of TNT protein due to open reading frame disruption or to post-translational degradation of TNT. (10.1136/jmedgenet-2019-106714)
  DOI : 10.1136/jmedgenet-2019-106714
• Phase behaviours of superionic water at planetary conditions
  
  • Cheng Bingqing
  • Bethkenhagen Mandy
  • Pickard Chris
  • Hamel Sebastien
  Nature Physics, Nature Publishing Group [2005-....], 2021, 17 (11), pp.1228-1232. Most water in the Universe may be superionic, and its thermodynamic and transport properties are crucial for planetary science but difficult to probe experimentally or theoretically. We use machine learning and free-energy methods to overcome the limitations of quantum mechanical simulations and characterize hydrogen diffusion, superionic transitions and phase behaviours of water at extreme conditions. We predict that close-packed superionic phases, which have a fraction of mixed stacking for finite systems, are stable over a wide temperature and pressure range, whereas a body-centred cubic superionic phase is only thermodynamically stable in a small window but is kinetically favoured. Our phase boundaries, which are consistent with existing—albeit scarce—experimental observations, help resolve the fractions of insulating ice, different superionic phases and liquid water inside ice giants. (10.1038/s41567-021-01334-9)
  DOI : 10.1038/s41567-021-01334-9
• Laser astrophysics experiment on the amplification of magnetic fields by shock-induced interfacial instabilities
  
  • Sano Takayoshi
  • Tamatani Shohei
  • Matsuo Kazuki
  • Law King Fai Farley
  • Morita Taichi
  • Egashira Shunsuke
  • Ota Masato
  • Kumar Rajesh
  • Shimogawara Hiroshi
  • Hara Yukiko
  • Lee Seungho
  • Sakata Shohei
  • Rigon Gabriel
  • Michel Thibault
  • Mabey Paul
  • Albertazzi Bruno
  • Koenig Michel
  • Casner Alexis
  • Shigemori Keisuke
  • Fujioka Shinsuke
  • Murakami Masakatsu
  • Sakawa Youichi
  Physical Review E, American Physical Society (APS), 2021, 104. (10.1103/physreve.104.035206)
  DOI : 10.1103/physreve.104.035206
• Scattering of ultrashort laser pulses on plasmons in a Maxwellian plasma
  
  • Astapenko V. A
  • Rosmej F. B
  • Khramov E. S
  Matter and Radiation at Extremes, AIP Publishing, 2021, 6 (5), pp.054404. On the basis of equations obtained in the framework of second-order quantum-mechanical perturbation theory, the standard approach to the calculation of scattering radiation probability is extended to the case of ultrashort laser pulses. We investigate the mechanism of the appearance of plasmon peaks in the spectrum of the plasma form factor for different parameters of the problem. For the case in which scattering on plasmons dominates over scattering on electron density fluctuations caused by chaotic thermal motion, we derive analytical expressions describing the scattering probability of ultrashort laser pulses on plasmons. Together with this, we obtain a simple expression connecting the frequency of scattered radiation and the energy transmitted from the incident pulse to plasmon, and vice versa. In considering the scattering probability, our emphasis is on the dependence on the pulse duration. We assess in detail the trends of this dependence for various relations between pulse carrier frequency and plasmon energy. (10.1063/5.0065835)
  DOI : 10.1063/5.0065835
• An Integrated Clinical-Biological Approach to Identify Interindividual Variability and Atypical Phenotype-Genotype Correlations in Myopathies: Experience on A Cohort of 156 Families
  
  • Juntas Morales Raul
  • Perrin Aurélien
  • Solé Guilhem
  • Lacourt Delphine
  • Pegeot Henri
  • Walther-Louvier Ulrike
  • Cintas Pascal
  • Cances Claude
  • Espil Caroline
  • Theze Corinne
  • Zenagui Reda
  • Yauy Kevin
  • Cosset Elodie
  • Renard Dimitri
  • Rigau Valerie
  • Maues de Paula Andre
  • Uro-Coste Emmanuelle
  • Arne-Bes Marie-Christine
  • Martin Négrier Marie-Laure
  • Leboucq Nicolas
  • Acket Blandine
  • Malfatti Edoardo
  • Biancalana Valérie
  • Metay Corinne
  • Richard Pascale
  • Rendu John
  • Rivier François
  • Koenig Michel
  • Cossée Mireille
  Genes, MDPI, 2021, 12 (8), pp.1199. Diagnosis of myopathies is challenged by the high genetic heterogeneity and clinical overlap of the various etiologies. We previously reported a Next-Generation Sequencing strategy to identify genetic etiology in patients with undiagnosed Limb-Girdle Muscular Dystrophies, Congenital Myopathies, Congenital Muscular Dystrophies, Distal Myopathies, Myofibrillar Myopathies, and hyperCKemia or effort intolerance, using a large gene panel including genes classically associated with other entry diagnostic categories. In this study, we report the comprehensive clinical-biological strategy used to interpret NGS data in a cohort of 156 pediatric and adult patients, that included Copy Number Variants search, variants filtering and interpretation according to ACMG guidelines, segregation studies, deep phenotyping of patients and relatives, transcripts and protein studies, and multidisciplinary meetings. Genetic etiology was identified in 74 patients, a diagnostic yield (47.4%) similar to previous studies. We identified 18 patients (10%) with causative variants in different genes (ACTA1, RYR1, NEB, TTN, TRIP4, CACNA1S, FLNC, TNNT1, and PAPBN1) that resulted in milder and/or atypical phenotypes, with high intrafamilial variability in some cases. Mild phenotypes could mostly be explained by a less deleterious effect of variants on the protein. Detection of inter-individual variability and atypical phenotype-genotype associations is essential for precision medicine, patient care, and to progress in the understanding of the molecular mechanisms of myopathies. (10.3390/genes12081199)
  DOI : 10.3390/genes12081199
• Backward-ion acceleration in critical density plasmas
  
  • Iwawaki T
  • Habara H
  • Nakaguchi S
  • Uematsu Y
  • Aizawa K
  • Enmei Y
  • Minami T
  • Baton S
  • Rousseaux C
  • Chen S N
  • Fuchs J
  • Nazarov W
  • Macdonald M
  • Kodama R
  • Tanaka K A
  , 2021.
• PISTIL interferometry diagnosis on a 61 channels coherent beam combining digital laser
  
  • Rouze Bastien
  • Bellanger Severine
  • Fsaifes Ihsan
  • Bellanger Cindy
  • Veinhard Matthieu
  • Chanteloup Jean-Christophe
  • Primot Jérôme
  , 2021, pp.1-1. Coherent beam combining (CBC) opens the way to a new paradigm in laser architecture [1] . The quest to high peak and average power indeed faces several fundamental limitations (transverse amplified spontaneous emission in wide amplifiers, thermal management issues) which can be addressed when relying on numerous smaller scale reliable lasers coherently combined. Achieving CBC for a large number of amplifiers will not only rely on the use of an efficient phase-locking scheme but also on fiber management inside the laser head (such as accurate angular and lateral positioning, at µm or mrad levels), optics, and amplifiers management as well as laboratory environment control. An accurate diagnosis of the laser array is mandatory in order to get significant feedback on its design, and potentially improve or stabilize its behavior, either in phase-locked loop or in free run. (10.1109/CLEO/Europe-EQEC52157.2021.9542514)
  DOI : 10.1109/CLEO/Europe-EQEC52157.2021.9542514
• Measuring the structure and equation of state of polyethylene terephthalate at megabar pressures
  
  • Lütgert J.
  • Vorberger J.
  • Hartley N. J
  • Voigt K.
  • Rödel M.
  • Schuster A. K
  • Benuzzi-Mounaix A.
  • Brown S.
  • Cowan T. E
  • Cunningham E.
  • Döppner T.
  • Falcone R. W
  • Fletcher L. B
  • Galtier E.
  • Glenzer S. H
  • Laso Garcia A.
  • Gericke D. O
  • Heimann P. A
  • Lee H. J
  • Mcbride E. E
  • Pelka A.
  • Prencipe I.
  • Saunders A. M
  • Schölmerich M.
  • Schörner M.
  • Sun P.
  • Vinci T.
  • Ravasio A.
  • Kraus D.
  Scientific Reports, Nature Publishing Group, 2021, 11 (1). We present structure and equation of state (EOS) measurements of biaxially orientated polyethylene terephthalate (PET, $$({\hbox {C}}_{10} {\hbox {H}}_8 {\hbox {O}}_4)_n$$ ( C 10 H 8 O 4 ) n , also called mylar) shock-compressed to ( $$155 \pm 20$$ 155 ± 20 ) GPa and ( $$6000 \pm 1000$$ 6000 ± 1000 ) K using in situ X-ray diffraction, Doppler velocimetry, and optical pyrometry. Comparing to density functional theory molecular dynamics (DFT-MD) simulations, we find a highly correlated liquid at conditions differing from predictions by some equations of state tables, which underlines the influence of complex chemical interactions in this regime. EOS calculations from ab initio DFT-MD simulations and shock Hugoniot measurements of density, pressure and temperature confirm the discrepancy to these tables and present an experimentally benchmarked correction to the description of PET as an exemplary material to represent the mixture of light elements at planetary interior conditions. (10.1038/s41598-021-91769-0)
  DOI : 10.1038/s41598-021-91769-0
• Numerical investigation of spallation neutrons generated from petawatt-scale laser-driven proton beams
  
  • Martinez B.
  • Chen S.N.
  • Bolaños S.
  • Blanchot N.
  • Boutoux G.
  • Cayzac W.
  • Courtois C.
  • Davoine X.
  • Duval A.
  • Horny V.
  • Lantuejoul I.
  • Deroff L. Le
  • Masson-Laborde P.E.
  • Sary G.
  • Vauzour B.
  • Smets R.
  • Gremillet L.
  • Fuchs J.
  , 2021. 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.
• Caractérisation hydrodynamique et spectroscopique de plasmas de carbone, aluminium et germanium produits par impulsion laser picoseconde
  
  • Morana Ambra
  , 2021. La spectroscopie X joue un rôle majeur dans le domaine des plasmas générés par laser, étant un outil crucial pour l'investigation de leurs propriétés atomiques, ainsi que de leur évolution hydrodynamique. Ce rôle devient encore plus important quand l'évolution du plasma est fortement déterminée par des phénomènes de transport radiatif. Ceci est le cas de la Fusion par Confinement Inertiel dans le cas d’attaque directe et indirecte.Afin de simuler l’évolution du plasma, il est nécessaire d’avoir des modèles fiables pour les codes d’hydrodynamique et de cinétique atomique. Dans le but de valider leurs hypothèses et approximations, il faut obtenir des données expérimentales qui couvrent la partie dédiée aux spectres d’émission ainsi qu’à l’évolution hydrodynamique de façon indépendante.Nous allons présenter les résultats des deux premières campagnes d’un projet pluriannuel. Les deux campagnes expérimentales ont été réalisées sur l’installation laser ELFIE du laboratoire LULI.Nous avons d’abord testé le dispositif expérimental avec la caractérisation de deux éléments bien connus : le carbone et l’aluminium. La conception de la cible et celle des paramètres laser ont été optimisées afin d’obtenir un plasma homogène. Dans ce cas, une impulsion laser de 5 ps à intensité modérée (I = 10^15 – 10^16 W/cm^2) a été focalisée sur une cible composée d’un substrat de Si3N4 et d’une couche de C ou d’Al. Deux diagnostics principaux ont été utilisés lors de cette expérience : l’un pour mesurer le profil de densité de plasma (interféromètre optique de type Nomarski) et l’autre pour mesurer l’émission X-XUV du plasma (spectromètre à réseau de diffraction). Les résultats concernant les propriétés hydrodynamiques et spectroscopiques du plasma ont été comparés aux sorties des simulations du code hydrodynamique MULTI-fs, ainsi que celles du code de cinétique atomique PrismSPECT, confirmant la fiabilité du dispositif. Un très bon accord a été trouvé entre les résultats expérimentaux et numériques pour l’aluminium et le carbone.La deuxième campagne a permis d’utiliser une configuration similaire pour l’étude du germanium, un matériau utilisé en guise d’ablateur lors des expériences de FCI. Une impulsion laser de 4 ps à haute intensité (I = 10^17 W/cm^2) a été focalisée sur des cibles de différentes épaisseurs d’aluminium, de germanium ou d’un mélange de ces deux matériaux. Le profil de densité électronique a été extrait à l’aide d’un diagnostic d’ombroscopie. Les spectres d’émission ont été mesurés avec un spectromètre Von Hamos à cristal PET dans la gamme 1500-2100 eV. Les résultats expérimentaux, après comparaison avec des résultats de simulations issus de MULTI-fs, ont montré que l’expansion hydrodynamique du plasma est fortement modifiée du fait de la présence d’une pré-impulsion. Les spectres expérimentaux ont été comparés aux résultats d’un modèle pour une température et une densité et aux spectres synthétiques intégrés en temps calculés à l’aide des codes de cinétique atomique PrismSPECT et DEDALE (CEA/DAM).La combinaison de ces deux diagnostics nous ont permis de reproduire l’expansion du plasma et l’émission X des deux éléments purs. L’analyse du mélange n’a montré aucune différence par rapport aux cas de chacun des deux éléments purs.Cependant, nous avons observé que le code MULTI-fs surestime les paramètres plasma dans les 200 premières picosecondes suivant le passage de l’impulsion laser principale. Cette surestimation provient probablement des limitations de modélisation de l’absorption laser dans le plasma. (10.70675/a73d160bze33fz4e03zbd67zbbf726b9550f)
  DOI : 10.70675/a73d160bze33fz4e03zbd67zbbf726b9550f
• Investigating strong-field QED processes in laser-electron beam collisions at Apollon
  
  • Grech M
  • Lancia L
  • Andriyash I A
  • Audebert P
  • Beck A
  • Corde S
  • Davoine X
  • Frotin M
  • Grassi A
  • Gremillet L
  • Le Pape S
  • Lobet M
  • Leblanc A
  • Mathieu F
  • Massimo F
  • Mercuri-Baron A
  • Papadopoulos D
  • Pérez F
  • Prudent J
  • Riconda C
  • Romagnani L
  • Specka A
  • Thaury C
  • Phuoc K Ta
  • Vinci T
  , 2021.
• Forward scattering and filamentation of a spatially smoothed laser pulse in the hydrodynamic and kinetic frameworks
  
  • Nakatsutsumi ‡ M
  • Ruyer C.
  • Debayle A.
  • Loiseau P.
  • Masson-Laborde P. E
  • Fuchs J.
  • Casanova M.
  • Marquès J. R
  • Romagnani L.
  • Antici P.
  • Bourgeois N.
  • Nakatsutsumi M.
  • Safronova M.
  • Starodubtsev M.
  • Lin T.
  Physics of Plasmas, American Institute of Physics, 2021, 28 (5), pp.052701. (10.1063/5.0043931)
  DOI : 10.1063/5.0043931
• Biallelic loss-of-function variations in PRDX3 cause cerebellar ataxia
  
  • Rebelo Adriana
  • Eidhof Ilse
  • Cintra Vivian
  • Guillot-Noel Léna
  • Pereira Claudia
  • Timmann Dagmar
  • Traschütz Andreas
  • Schöls Ludger
  • Coarelli Giulia
  • Durr Alexandra
  • Anheim Mathieu
  • Tranchant Christine
  • van de Warrenburg Bart
  • Guissart Claire
  • Koenig Michel
  • Howell Jack
  • Moraes Carlos
  • Schenck Annette
  • Stevanin Giovanni
  • Züchner Stephan
  • Synofzik Matthis
  Brain - A Journal of Neurology, Oxford University Press, 2021, 144 (5), pp.1467-1481. Abstract Peroxiredoxin 3 (PRDX3) belongs to a superfamily of peroxidases that function as protective antioxidant enzymes. Among the six isoforms (PRDX1–PRDX6), PRDX3 is the only protein exclusively localized to the mitochondria, which are the main source of reactive oxygen species. Excessive levels of reactive oxygen species are harmful to cells, inducing mitochondrial dysfunction, DNA damage, lipid and protein oxidation and ultimately apoptosis. Neuronal cell damage induced by oxidative stress has been associated with numerous neurodegenerative disorders including Alzheimer’s and Parkinson’s diseases. Leveraging the large aggregation of genomic ataxia datasets from the PREPARE (Preparing for Therapies in Autosomal Recessive Ataxias) network, we identified recessive mutations in PRDX3 as the genetic cause of cerebellar ataxia in five unrelated families, providing further evidence for oxidative stress in the pathogenesis of neurodegeneration. The clinical presentation of individuals with PRDX3 mutations consists of mild-to-moderate progressive cerebellar ataxia with concomitant hyper- and hypokinetic movement disorders, severe early-onset cerebellar atrophy, and in part olivary and brainstem degeneration. Patient fibroblasts showed a lack of PRDX3 protein, resulting in decreased glutathione peroxidase activity and decreased mitochondrial maximal respiratory capacity. Moreover, PRDX3 knockdown in cerebellar medulloblastoma cells resulted in significantly decreased cell viability, increased H2O2 levels and increased susceptibility to apoptosis triggered by reactive oxygen species. Pan-neuronal and pan-glial in vivo models of Drosophila revealed aberrant locomotor phenotypes and reduced survival times upon exposure to oxidative stress. Our findings reveal a central role for mitochondria and the implication of oxidative stress in PRDX3 disease pathogenesis and cerebellar vulnerability and suggest targets for future therapeutic approaches. (10.1093/brain/awab071)
  DOI : 10.1093/brain/awab071
• Liquid Structure of Tantalum under Internal Negative Pressure
  
  • Katagiri K.
  • Ozaki N.
  • Ohmura S.
  • Albertazzi Bruno
  • Hironaka Y.
  • Inubushi Y.
  • Ishida K.
  • Koenig Michel
  • Miyanishi K.
  • Nakamura H.
  • Nishikino M.
  • Okuchi T.
  • Sato T.
  • Seto Y.
  • Shigemori Keisuke
  • Sueda K.
  • Tange Y.
  • Togashi T.
  • Umeda Y.
  • Yabashi M.
  • Yabuuchi T.
  • Kodama R.
  Physical Review Letters, American Physical Society, 2021, 126 (1), pp.012027. In situ femtosecond x-ray diffraction measurements and ab initio molecular dynamics simulations were performed to study the liquid structure of tantalum shock released from several hundred gigapascals (GPa) on the nanosecond timescale. The results show that the internal negative pressure applied to the liquid tantalum reached −5.6 ð0.8Þ GPa, suggesting the existence of a liquid-gas mixing state due to cavitation. This is the first direct evidence to prove the classical nucleation theory which predicts that liquids with high surface tension can support GPa regime tensile stress. (10.1103/physrevlett.126.175503)
  DOI : 10.1103/physrevlett.126.175503
• Enhanced X-ray emission arising from laser-plasma confinement by a strong transverse magnetic field
  
  • Filippov Evgeny D
  • Makarov Sergey S
  • Burdonov Konstantin F
  • Yao Weipeng
  • Revet Guilhem
  • Béard Jérome
  • Bolaños Simon
  • Chen Sophia N
  • Guediche Amira
  • Hare Jack
  • Romanovsky Denis
  • Skobelev Igor Yu
  • Starodubtsev Mikhail
  • Ciardi Andrea
  • Pikuz Sergey A
  • Fuchs J.
  Scientific Reports, Nature Publishing Group, 2021, 11 (1), pp.8180. We analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 10[Formula: see text]-10[Formula: see text] W/cm[Formula: see text]) from a solid target as it expands into a homogeneous, strong magnetic field (up to 30 T) that is transverse to its main expansion axis. We find that as early as 2 ns after the start of the expansion, the plasma becomes constrained by the magnetic field. As the magnetic field strength is increased, more plasma is confined close to the target and is heated by magnetic compression. We also observe that after [Formula: see text] ns, the plasma is being overall shaped in a slab, with the plasma being compressed perpendicularly to the magnetic field, and being extended along the magnetic field direction. This dense slab rapidly expands into vacuum; however, it contains only [Formula: see text] of the total plasma. As a result of the higher density and increased heating of the plasma confined against the laser-irradiated solid target, there is a net enhancement of the total X-ray emissivity induced by the magnetization. (10.1038/s41598-021-87651-8)
  DOI : 10.1038/s41598-021-87651-8
• Rayleigh-Taylor mixing may account for the position anomaly in NIF dot experiments
  
  • Poujade Olivier
  • Barrios M.A.
  • Baton S. D.
  • Blancard Christophe
  • Devriendt Ronan
  • Primout Michel
  Physics of Plasmas, American Institute of Physics, 2021, 28, pp.042704. (10.1063/5.0040583)
  DOI : 10.1063/5.0040583
• Inferring possible magnetic field strength of accreting inflows in EXor-type objects from scaled laboratory experiments
  
  • Burdonov K.
  • Bonito R.
  • Giannini T.
  • Aidakina N.
  • Argiroffi C.
  • Béard Jérome
  • Chen S. N.
  • Ciardi A.
  • Ginzburg V.
  • Gubskiy K.
  • Gundorin V.
  • Gushchin M.
  • Kochetkov A.
  • Korobkov S.
  • Kuzmin A.
  • Kuznetsov A.
  • Pikuz S.
  • Revet G.
  • Ryazantsev S.
  • Shaykin A.
  • Shaykin I.
  • Soloviev A.
  • Starodubtsev M.
  • Strikovskiy A.
  • Yao W.
  • Yakovlev I.
  • Zemskov R.
  • Zudin I.
  • Khazanov E.
  • Orlando S.
  • Fuchs J.
  Astronomy & Astrophysics - A&A, EDP Sciences, 2021, 648, pp.A81. Aims. EXor-type objects are protostars that display powerful UV-optical outbursts caused by intermittent and powerful events of magnetospheric accretion. These objects are not yet well investigated and are quite difficult to characterize. Several parameters, such as plasma stream velocities, characteristic densities, and temperatures, can be retrieved from present observations. As of yet, however, there is no information about the magnetic field values and the exact underlying accretion scenario is also under discussion.Methods. We use laboratory plasmas, created by a high power laser impacting a solid target or by a plasma gun injector, and make these plasmas propagate perpendicularly to a strong external magnetic field. The propagating plasmas are found to be well scaled to the presently inferred parameters of EXor-type accretion event, thus allowing us to study the behaviour of such episodic accretion processes in scaled conditions.Results. We propose a scenario of additional matter accretion in the equatorial plane, which claims to explain the increased accretion rates of the EXor objects, supported by the experimental demonstration of effective plasma propagation across the magnetic field. In particular, our laboratory investigation allows us to determine that the field strength in the accretion stream of EXor objects, in a position intermediate between the truncation radius and the stellar surface, should be of the order of 100 G. This, in turn, suggests a field strength of a few kilogausses on the stellar surface, which is similar to values inferred from observations of classical T Tauri stars. (10.1051/0004-6361/202040036)
  DOI : 10.1051/0004-6361/202040036
• Calibration of the scintillation of cerium-doped yttrium aluminum garnet crystals irradiated by monoenergetic 4 MeV energy electrons
  
  • Burdonov K.
  • Forestier-Colleoni P.
  • Cayla J-N
  • Ceccotti T.
  • Chancé S.
  • Chaumat V.
  • Delerue N.
  • Guler H.
  • Lelasseux V.
  • Lucas B.
  • Fuchs J.
  , 2021. This paper presents the results of measurements of fluorescing cerium-doped yttrium aluminum garnet crystals after being irradiated by an accelerated electron beam with energy of around 4 MeV. The measurements were performed using the PHIL linear accelerator at LAL (France). We observe linear dependence of the crystal emission to the electron beam charge and the isotropy of the photon emission. We provide the calibration coefficients of the photon emission depending on the charge of the accelerated electron beam for two crystals originating from two different manufacturers.
• 61 channels coherent beam combining femtosecond digital laser
  
  • Chanteloup Jean-Christophe
  • Bellanger Severine
  • Daniault Louis
  • Fsaifes Ihsan
  • Veinhard Matthieu
  • Bourderionnet Jérôme
  • Larat Christian
  • Lallier Eric
  • Brignon Arnaud
  , 2021, 11665. Tiled-aperture Coherent Beam Combination architecture opens the way to digital laser operating in high peak and average power regimes. (10.1117/12.2576606)
  DOI : 10.1117/12.2576606