Search for photon oscillations into massive particles

International audienceIn this paper, we present the final results of our experiment on photon-axion oscillations in the presence of a magnetic field, which took place at LULI (Laboratoire pour l'Utilisation des Lasers Intenses, Palaiseau, France). Our null measurement allowed us to exclude the existence of axions with inverse coupling constant $M>9.\times 10^5$ GeV for low axion masses and to improve the preceding BFRT limits by a factor 3 or more for axion masses $1.1\, \mbox{meV

Effects of self-generated electric and magnetic fields in laser-generated fast electron propagation in solid materials: Electric inhibition and beam pinching

We present some experimental results which demonstrate the presence of electric inhibition in the propagation of relativistic electrons generated by intense laser pulses, depending on target conductivity. The use of transparent targets and shadowgraphic techniques has made it possible to evidence electron jets moving at the speed of light, an indication of the presence of self-generated strong magnetic fields

Experimental Study of electron acceleration by plasma beat-waves with Nd lasers

International audienceWe have observed the acceleration of electrons by a beat-wave generated in a deuterium plasma by two Nd-YAG and Nd-YLF laser wavelengths. Electrons injected at an energy of 3.3 MeV are observed to be accelerated up to 4.7 MeV after the plasma. The energy gain is compatible with a peak electric field of the order of 1.2 GV/m. The experiment has been performed with different injection energies, from 2.5 to 3.3 MeV, with different plasma dimensions, and with different laser intensitie

Fast electron transport and heating in solid-density matter

Two experiments have been performed to investigate heating by high-intensity laser-generated electrons, in the context of studies of the fast ignitor approach to inertial confinement fusion (ICF). A new spectrometer and layered targets have been used to detect Kα emission from aluminum heated by a fast electron beam. Results show that a temperature of about 40 eV is reached in solid density aluminum up to a depth of about 100 μm

Apollon : le laser de l’extrême

Étudier les plasmas relativistes et l’interaction lumière-matière dans des conditions extrêmes, produire de nouvelles sources intenses et brèves de particules et de rayonnement pour une large gamme d’applications, interagir avec les particules virtuelles du vide et atteindre le régime de l’électrodynamique quantique en champ fort, tels sont les défis d’Apollon, une nouvelle infrastructure de recherche laser en construction sur le Plateau de Saclay. D’une puissance inégalée allant jusqu’à 10 pétawatts (PW), les impulsions énergétiques et brèves délivrées par le faisceau principal d’Apollon, jusqu’à 150 joules en 15 femtosecondes (fs), permettront à une large communauté de se lancer dans de nouvelles recherches, aux frontières des connaissances actuelles

Génération et transport des électrons rapides dans l'interaction laser-plasma à haut flux

PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF

HiPER: The European path to laser energy

While for decades, energy production relying on laser inertial fusion has been a strong motivation for the development in Europe of a few high-energy laser facilities and dedicated scientific programs, the HiPER initiative launched in 2004 fostered an ambitious large-scale coordinated European program toward inertial fusion energy. Anticipating the successful demonstration of fusion ignition and gain at the National Ignition Facility (NIF) in the USA, scientists and engineers from across Europe are developing the case for a next generation laser fusion facility, HiPER, to be constructed in Europe. The single-facility build strategy of HiPER (High Power Laser Energy Research Facility) aims at first demonstrating some key elements of a fusion reactor in a high rep-rate few-second cycle mode, before addressing energy production on a high rep-rate continuous mode in a second area

Amplification laser et diagnostic temporel de paquets d'électrons ultra-relativistes en interaction laser-plasma

La thèse dont ce manuscrit fait l objet traite de deux des possibles applications de l interaction d un laser intense avec la matière. La première de ces applications est l utilisation d un plasma pour catapulter des particules à des énergies relativistes. Un plasma peut en effet supporter des champs électriques cent, voir mille fois supérieurs à ceux dans les matériaux classiques. Les lasers de puissance permettent d exploiter cette capacité en engendrant d importants champs électriques de sillage afin d accélérer des électrons. Dans le présent manuscrit est étudié en particulier la mise ne place d un nouveau diagnostic de mesure de durée pour les faisceaux d électrons obtenus. Le diagnostic est basé sur une technique électro-optique et possède une excellente résolution. Son étude, sa mise en place, ses tests et ses premiers résultats sont présentés. La seconde application que couvre ce manuscrit est l utilisation d un plasma comme amplificateur laser, en régime dit de super-radiance. En effet, un amplificateur laser est un élément capable de transférer de l énergie d une source extérieure vers l impulsion laser qui le traverse. Or un plasma, par le biais des ondes qu il véhicule, est capable de réaliser ce transfert, tout en supportant des intensités bien supérieures aux techniques d amplification traditionnelles. Si ce domaine d étude est encore récent, sa maîtrise constitue pourtant un des développements clé qui pourrait conduire la technologie laser vers des seuils d intensité encore jamais atteint.The present thesis relates of two specific applications of the laser-matter interaction scheme.The first of those applications is using a plasma as a relativistic particles accelerator. A plasma can actually support electric fields far beyond what classical materials are capable of. High intensity lasers can be used to generate large electric wake fields in order to accelerate electrons. The thesis discuss of such experiments and in particular of the integration of a new diagnostic to mesure the duration of the produced electron beams. The diagnostic is based on an electro-optic technic and has a very good resolution. Study, setup and first results are presented.The second application covered is the use of a plasma as a laser amplificator, in the so-called regime of super-radiance. Actually, a plasma is capable of transfering large amounts of energy from a laser beam to another via the waves it carries. Developping such a technic could be usefull to achieve laser intensities far beyond the actual limits. This field of study is only at its beginings, but some first results are presented.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF