Zettawatt-Exawatt Lasers and Their Applications in Ultrastrong-Field Physics: High Energy Front

Since its birth, the laser has been extraordinarily effective in the study and applications of laser-matter interaction at the atomic and molecular level and in the nonlinear optics of the bound electron. In its early life, the laser was associated with the physics of electron volts and of the chemical bond. Over the past fifteen years, however, we have seen a surge in our ability to produce high intensities, five to six orders of magnitude higher than was possible before. At these intensities, particles, electrons and protons, acquire kinetic energy in the mega-electron-volt range through interaction with intense laser fields. This opens a new age for the laser, the age of nonlinear relativistic optics coupling even with nuclear physics. We suggest a path to reach an extremely high-intensity level $10^{26-28}$W/cm$^2$ in the coming decade, much beyond the current and near future intensity regime $10^{23}$W/cm$^2$, taking advantage of the megajoule laser facilities. Such a laser at extreme high intensity could accelerate particles to frontiers of high energy, tera-electron-volt and peta-electron-volt, and would become a tool of fundamental physics encompassing particle physics, gravitational physics, nonlinear field theory, ultrahigh-pressure physics, astrophysics, and cosmology. We focus our attention on high-energy applications in particular and the possibility of merged reinforcement of high-energy physics and ultraintense laser.Comment: 25 pages. 1 figur

Status of pelagic habitats within the EU-Marine Strategy Framework Directive: Proposals for improving consistency and representativeness of the assessment

Anthropogenic activities have transformed the pelagic habitat in the last decades with profound implications for its essential functions. While the EU-Marine Strategy Framework Directive 2008/56/EC and the Commission Decision (EU) 2017/848 have set criteria and methodological standards for the assessment and determination of Good Environmental Status (GES) for pelagic habitats in EU waters, there is strong evidence that Member States have not yet harmonized the pelagic GES assessment across EU marine waters. Today, pelagic habitats are assessed by evaluating whether good status is achieved by each of the pelagic indicators, but this approach fails to observe the high variability of the pelagic environment. To this end, GES is not estimated at pelagic habitats scale but only for each individual indicator. This paper synthesises the latest developments on pelagic habitats assessment and identifies the main factors limiting the consistency of the assessment across Member States: i) coarse spatial and temporal scales of sampling effort as regards to the pelagic habitat dynamics, ii) little consideration of the whole range of plankton (and, to some extent, of zooplankton) size and trophic spectra, iii) lack of integrated hydro-biogeochemical and biological studies and collaboration among experts from different scientific fields, iv) limited availability of pressure-based indicators, and v) lack of integration methods of the pelagic indicators’ status for the GES determination. This analysis demonstrates the importance of maintaining a consistent sampling frequency and a spatially extensive network of stations across the gradient of anthropogenic pressures, where spatial environmental data can help objectively extrapolating field data

Technical Design Report EuroGammaS proposal for the ELI-NP Gamma beam System

The machine described in this document is an advanced Source of up to 20 MeV Gamma Rays based on Compton back-scattering, i.e. collision of an intense high power laser beam and a high brightness electron beam with maximum kinetic energy of about 720 MeV. Fully equipped with collimation and characterization systems, in order to generate, form and fully measure the physical characteristics of the produced Gamma Ray beam. The quality, i.e. phase space density, of the two colliding beams will be such that the emitted Gamma ray beam is characterized by energy tunability, spectral density, bandwidth, polarization, divergence and brilliance compatible with the requested performances of the ELI-NP user facility, to be built in Romania as the Nuclear Physics oriented Pillar of the European Extreme Light Infrastructure. This document illustrates the Technical Design finally produced by the EuroGammaS Collaboration, after a thorough investigation of the machine expected performances within the constraints imposed by the ELI-NP tender for the Gamma Beam System (ELI-NP-GBS), in terms of available budget, deadlines for machine completion and performance achievement, compatibility with lay-out and characteristics of the planned civil engineering

Habitat modelling for the blue shark (Prionace glauca) by sex and size classes in the Indian Ocean

This paper is a regional focus in the Indian Ocean (IO) of a global analysis of blue shark (Prionace glauca) habitat by size and sex classes (small juveniles, large juvenile males and females, adult males and females, Druon et al., in prep.). The habitat modeling, calibrated using fishing interaction data (i.e., fishery observer data) and electronic tracking data, uses two feeding proxies, i.e., the satellite-derived productivity fronts in mesotrophic areas and the mesopelagic micronekton in oligotrophic areas, and two abiotic variables, i.e., temperature and sea surface height anomaly. The temperature niche includes sea surface temperature (SST) and temperature 100 m below the mixed layer depth (Tmld+100) to ensure that both the horizontal and vertical extent of this thermoregulated species‘ habitat are covered. Here we show that the overall feeding niche displays highly diverse biotic and abiotic conditions although the blue shark population tends to progress from mesotrophic and relatively cold surface waters for the juvenile stages (North and South of IO) to more oligotrophic and warm surface waters for the adults (central IO). However, warm temperatures or low productivity limit the habitat of mostly the juveniles in the Central and/or North IO mainly in Apr-Jun and Jul-Sep. Large females tend to have more habitat overlap with small juveniles than large males, notably driven by temperature preferences. Large females also display an intermediate range of SST avoidance resulting in an important lack of habitat overlap with large males mostly in Jan-Mar and Apr-Jun in the South IO around 30°S. In Oct-Dec however, fisheries observer data show a higher habitat overlap between large males and females in this intermediate SST range, which may correspond to mating. These results on blue shark habitat provide key elements useful to stock assessment models and potential leads for conservation and management measures of this near-threatened species