We report the observation of multiple ionization of argon through multi-XUV-photon absorption induced by an unprecedentedly powerful laser driven high-order harmonic generation source. Comparing the measured intensity dependence of the yield of the different argon charge states with numerical calculations we can infer the different channels-direct and sequential-underlying the interaction. While such studies were feasible so far only with free electron laser (FEL) sources, this paper connects highly nonlinear XUV processes with the ultrashort time scales inherent to the harmonic pulses and highlights the advanced perspectives of emerging large scale laser research infrastructures.

No abstract

Evaluation of the fused silica thermal conductivity by comparing infrared thermometry measurements with twodimensional simulations Appl.

International audienceA compact, versatile table-top kilohertz source of coherent extreme-ultraviolet (XUV) radiation in the wavelength region 18–100 nm, based on high-order harmonic generation from noble gases induced by a 40-femtosecond Ti:sapphire laser system, is presented. The XUV beamline delivers at its output 10^8 photons/s at a wavelength of 23 nm. The monochromatized XUV radiation is directly focused onto a 10^-2-mm^2 spot by a toroidal grating, allowing one to reach intensities higher than 10^6 W/cm^2. Optimization results are presented for a new XUV-generating geometry, utilizing a ‘semi-infinite' quasi-static gas cell and strong focusing. In those conditions, we observe an anomalous inversion between the cutoffs of argon and krypton, with the krypton spectrum extending to much higher orders than expected in an adiabatic limit

Articles you may be interested inHigh quality single shot ultrafast MeV electron diffraction from a photocathode radio-frequency gun Rev. Sci. Instrum. 85, 083701 (2014); 10.1063/1.4892135High quality single shot diffraction patterns using ultrashort megaelectron volt electron beams from a radio frequency photoinjector Rev. Sci. Instrum. 81, 013306 (2010); 10.1063/1.3292683Stability improvement at high emission densities for gold thin film photocathodes used in advanced electron beam lithography