15 research outputs found
Démographie, structures foncières et société : évolution d’un village d’Artois du VIe au XIXe siècle
Multiplicity of electron- and photon-seeded electromagnetic showers at multi-petawatt laser facilities
Electromagnetic showers developing from the collision of an ultra-intense
laser pulse with a beam of high-energy electrons or photons are investigated
under conditions relevant to future experiments on multi-petawatt laser
facilities. A semi-analytical model is derived that predicts the shower
multiplicity, i.e. the number of pairs produced per incident seed particle
(electron or gamma photon). The model is benchmarked against particle-in-cell
simulations and shown to be accurate over a wide range of seed particle
energies (100 MeV - 40 GeV), laser relativistic field strengths (), and quantum parameter (ranging from 1 to 40). It is shown
that, for experiments expected in the next decade, only the first generations
of pairs contribute to the shower while multiplicities larger than unity are
predicted. Guidelines for forthcoming experiments are discussed considering
laser facilities such as Apollon and ELI Beamlines. The difference between
electron- and photon seeding and the influence of the laser pulse duration are
investigated.Comment: 23 pages, 9 figure
Crystal structure of type 2 isopentenyl diphosphate isomerase from Thermus thermophilus in complex with inorganic pyrophosphate
The N-terminal region is stabilized in the crystal structure of T. thermophilus type 2 IPP isomerase in complex with inorganic pyrophosphate; providing new insights about the active site and the catalytic mechanism of the enzyme. The PPi moiety is located near the conserved residues, H10, R97, H152, Q157, E158 and W219, and the flavin cofactor. The putative active site of IDI-2 provides interactions for stabilizing a carbocationic intermediate similar to those that stabilize the intermediate in the well-established protonation/deprotonation mechanism of IDI-1
Multiplicity of electron- and photon-seeded electromagnetic showers at multi-petawatt laser facilities
International audienceElectromagnetic showers developing from the collision of an ultra-intense laser pulse with a beam of high-energy electrons or photons are investigated under conditions relevant to future experiments on multi-petawatt laser facilities. A semi-analytical model is derived that predicts the shower multiplicity, i.e. the number of pairs produced per incident seed particle (electron or gamma photon). The model is benchmarked against particle-in-cell simulations and shown to be accurate over a wide range of seed particle energies (100 MeV - 40 GeV), laser relativistic field strengths (), and quantum parameter (ranging from 1 to 40). It is shown that, for experiments expected in the next decade, only the first generations of pairs contribute to the shower while multiplicities larger than unity are predicted. Guidelines for forthcoming experiments are discussed considering laser facilities such as Apollon and ELI Beamlines. The difference between electron- and photon seeding and the influence of the laser pulse duration are investigated
Multiplicity of electron- and photon-seeded electromagnetic showers at multi-petawatt laser facilities
International audienceElectromagnetic showers developing from the collision of an ultra-intense laser pulse with a beam of high-energy electrons or photons are investigated under conditions relevant to future experiments on multi-petawatt laser facilities. A semi-analytical model is derived that predicts the shower multiplicity, i.e. the number of pairs produced per incident seed particle (electron or gamma photon). The model is benchmarked against particle-in-cell simulations and shown to be accurate over a wide range of seed particle energies (100 MeV - 40 GeV), laser relativistic field strengths (), and quantum parameter (ranging from 1 to 40). It is shown that, for experiments expected in the next decade, only the first generations of pairs contribute to the shower while multiplicities larger than unity are predicted. Guidelines for forthcoming experiments are discussed considering laser facilities such as Apollon and ELI Beamlines. The difference between electron- and photon seeding and the influence of the laser pulse duration are investigated