State selective measurements of HCI produced by strong ultrashort laser clusters interaction

International audienceWe have performed studies of keV x-ray production from (Ar)n , (Kr)n and (Xe)n rare gas clusters (with n between 104 and 106 atoms/cluster) submitted to intense (~10^18 W/cm2) infrared (790 nm) laser pulses. We have determined the photon energies and the absolute photon emission yields as a function of several physical parameters governing the interaction : size and atomic number of the clusters, peak intensity of the laser. Up to 10^6 3 keV photons per pulse at a moderate (10^15/cm3) atomic density have been observed. High resolution spectroscopy studies in the case of (Ar)n clusters have also been performed, giving unambiguous evidence of highly charged (up to heliumlike) ions with K vacancies production. The results obtained indicate that X-rays are emitted before cluster explosion on a subpicosecond time scale, and shed some light on the mechanisms involved in the first stage of the production of the nanoplasma induced from each cluster

Water Deficit-Responsive QTLs for Cell Wall Degradability and Composition in Maize at Silage Stage

The use of lignocellulosic biomass for animal feed or biorefinery requires the optimization of its degradability. Moreover, biomass crops need to be better adapted to the changing climate and in particular to periods of drought. Although the negative impact of water deficit on biomass yield has often been mentioned, its impact on biomass quality has only been recently reported in a few species. In the present study, we combined the mapping power of a maize recombinant inbred line population with robust near infrared spectroscopy predictive equations to track the response to water deficit of traits associated with biomass quality. The population was cultivated under two contrasted water regimes over 3 consecutive years in the south of France and harvested at silage stage. We showed that cell wall degradability and β-O-4-linked H lignin subunits were increased in response to water deficit, while lignin and p-coumaric acid contents were reduced. A mixed linear model was fitted to map quantitative trait loci (QTLs) for agronomical and cell wall-related traits. These QTLs were categorized as “constitutive” (QTL with an effect whatever the irrigation condition) or “responsive” (QTL involved in the response to water deficit) QTLs. Fifteen clusters of QTLs encompassed more than two third of the 213 constitutive QTLs and 13 clusters encompassed more than 60% of the 149 responsive QTLs. Interestingly, we showed that only half of the responsive QTLs co-localized with constitutive and yield QTLs, suggesting that specific genetic factors support biomass quality response to water deficit. Overall, our results demonstrate that water deficit favors cell wall degradability and that breeding of varieties that reconcile improved drought-tolerance and biomass degradability is possible

40th European Physical Society Conference on Plasma Physics

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41st European Physical Society Conference on Plasma Physics

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Special issue: Inertial Fusion State of the Art–a collection of overview and technical papers from IFSA2017

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ATOMIC PARAMETERS FOR NE-LIKE AG COLLISIONAL EXCITATION X-RAY LASER SIMULATIONS

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APOLLON: a multi-PW laser facility: on behalf of the APOLLON project team and of the CILEX consortium

International audienceAPOLLON laser facility was initiated by Nobel Laureat Gérard Mourou to become one of the few European 10 PW laser facilities. End of 2018, APOLLON reached 1 PW peak power. Experiments at this power are under preparation with an expected start during spring 2019 or early summer. In parallel, today the laser is under upgrade for reaching 10 PW in few years with an intermediate step at around 5 PW dedicated to the development of experiments at this high power. APOLLON will be open for external users on 2020 at 1 PW and very likely on 2021 at several PW. APOLLON has two experimental areas on which X-ray sources will be developed. The so-called "Long focal length area" (LFA) is dedicated to electron acceleration and related X-ray emission. The room may accommodate focal length up to 9m. The experiments are designed in a way to allows single or double stage electron acceleration with expected electron energies reaching several 10's of GeV. X-ray emission from betatron will be used as a diagnostic of electron acceleration processes but will be also developed independently aiming at achieving energetic and well-collimated X-ray beam. The experiment has been set in a way to allows heads-on electron-laser collision for Compton scattering experiments. The second target area called "Short Focal area", aims at achieving intensities as high as possible for electron and ion acceleration, non-linear QED tests and X-ray generation through high harmonic generation on solid. X-ray emission ranging up to 10 keV is foreseen, with very high peak power at lower energy

43rd European Physical Society Conference on Plasma Physics

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