Two-dimensional simulations of laser-plasma interaction and hot electron generation in the context of shock-ignition research

Laser-plasma interaction and hot electron generation play a crucial role in the context of inertial confinement fusion and in particular in the shock-ignition concept. Here we present a fully kinetic large-scale two-dimensional simulation studying laser-plasma interaction and hot electron generation in a relatively long and hot coronal plasma. The simulation shows saturation of the reflectivity of an intense spike pulse and absorption taking place close to a quarter critical density in particular, due to cavitation and stimulated Raman scattering. The signatures of steady two-plasmon decay are observed, but the hot electron number produced by this instability is low in comparison with the other two processes. The spectral and angular distribution of the back-scattered light is presented and the energy and angular characteristics of hot electrons due to individual absorption processes are studied

Physics of laser plasma interaction and particle transport in the context of inertial confinement fusion

Lasers are unique tools for transporting extremely high powers over large distances, but transfer of such a power from photons to matter in small volumes is a very complicated problem. First of all, the interaction proceeds very far from equilibrium, as with photons having energy of a few electron-volts one would like to heat plasma to temperatures thousand times higher. Second, these processes are strongly nonlinear, as they correspond to transfer energies of a large number of photons to a much smaller number of charged particles in extremely small volumes and in very short time scales. Research in inertial confinement fusion (ICF) gave a strong push for studying all these processes in detail, and now, although many issues remain to be resolved, we have quite a good understanding of how they operate in ICF conditions and what limitations and advantages they offer.In this short review, I share my personal recollections of almost 50 years history of the physics of laser plasma interaction. Understanding of highly nonlinear microscopic processes allowed us to improve the hydrodynamic performance of ICF targets and to foresee future developments. The key point is that multiscale modeling allowed for the retainment of major elements of microscopic physics in macroscopic hydrodynamic codes and make them more accurate and predictive.Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortiu

Surveillance in eradication and elimination of infectious diseases: a progression through the years.

During the years since certification of smallpox eradication, the power of infectious disease surveillance has been greatly increased by new biotechnical and electronic technologies. These technologies have transformed the way that surveillance can be used to contribute to public health, and to infectious disease eradication and elimination. In addition to permitting precise geographical placement of infections by incorporating the most up to date geographical positioning systems, infectious disease surveillance can now also provide more comprehensive understanding of the spread and risks of infections because of genomic sequencing that leads to more meaningful epidemiological analysis. These new technologies have made infectious disease surveillance an even more powerful and timely tool than it was during the period of smallpox eradication. Future surveillance will continue to refine these technologies, and adapt newer ones such as rapid point of care diagnostics and hand held communication devices that will lead to more timely and accurate reporting from health facilities. These technologies will also lead to the possibility of direct participation in surveillance by individuals who will be able to report their own disease syndromes, those of their neighbors, or those of domestic and wild animals at the animal/human interface

Laser ion acceleration in the high laser energy and high laser intensity regimes

New laser facilities able to deliver either ultra high energy short pulses or ultra high intensity pulses are being constructed and will open new and exciting opportunities for laser ion acceleration. The interaction of a high intensity short pulse with underdense, near-critical and overdense targets has been studied using 2D Particle-In-Cell simulations in these regimes. In the ultra high energy regime, proton beams with maximum energies of hundreds of MeV and a high number of high energy protons could be accelerated using thin solid foils or low density targets. In the ultra high intensity regime, radiation losses will start affecting laser ion acceleration using thin overdense targets for intensities higher than 1022  W/cm2, and produce very energetic ions

Laser ion acceleration in the high laser energy and high laser intensity regimes

New laser facilities able to deliver either ultra high energy short pulses or ultra high intensity pulses are being constructed and will open new and exciting opportunities for laser ion acceleration. The interaction of a high intensity short pulse with underdense, near-critical and overdense targets has been studied using 2D Particle-In-Cell simulations in these regimes. In the ultra high energy regime, proton beams with maximum energies of hundreds of MeV and a high number of high energy protons could be accelerated using thin solid foils or low density targets. In the ultra high intensity regime, radiation losses will start affecting laser ion acceleration using thin overdense targets for intensities higher than 1022  W/cm2, and produce very energetic ions

Collective properties of a relativistic electron beam injected into a high intensity optical lattice

Behaviour of a relativistic electron bunch, injected and trapped in a high intensity optical lattice resulting from the interference of two laser beams is studied. The optical lattice modifies the phase space distribution of the electron bunch due to the trapping and compression of the electrons by a ponderomotive force. High-frequency longitudinal beam eigenmodes of the trapped electron bunch are described in the framework of fluid and kinetic models. Such beam oscillations are expected to play a pivotal role in a stimulated Raman scattering of laser beams on the electrons

Scattering of relativistic electron beam by two counter-propagating laser pulses: A new approach to Raman X-ray amplification

We present a detailed study of the properties of electron beam injected and trapped in an high intensity optical lattice. By using the hydrodynamic and kinetic approaches, we identified the beam trapping conditions, the high-frequency longitudinal beam eigenmodes and their dependence on the electron angular and energy spread. The coupling of these beam eigenmodes to the laser waves is also considered. This corresponds to the convective parametric instability: a stimulated scattering of two laser beams creating the optical lattice on the trapped electron beam mode. The amplification coefficients for the up-scattered Raman modes propagating parallel to the electron beam are calculated and their dependence on the beam characteristics is analyzed

New Issues on Stimulated Brillouin Scattering in a Laser-Produced Plasma

Good agreement between Stimulated Brillouin Scattering (SBS) measurements and the convective theory of SBS in randomly distributed speckles has been achieved thanks to recent progress in both the experimental and the theoretical parts. Modification of SBS in presence of a secondary interaction beam demonstrates the sensitivity of SBS to initial ion density fluctuations in the plasma