High photon flux Kα Mo x-ray source driven by a multi-terawatt femtosecond laser at 100 Hz

We develop a pulsed hard x-ray K α source at 17.4 keV produced by the interaction of a multi-terawatt peak power in-frared femtosecond laser pulse with a thick molybdenum (Mo) target at a 100 Hz repetition rate. We measure the highest Mo K α photon production reported to date corresponding to a K α photon flux of 1×10 11 ph∕sr·s and an estimated peak brightness of ∼2.5×10 17 ph∕s·mm 2 ·mrad 2 0.1%bandwidth at ∼5 × 10 18 W∕cm 2 driving laser intensity.The Integrated Initiative of European Laser Research Infrastructure

High repetition rate (100 Hz), high peak power, high contrast femtosecond laser chain

High intensity femtosecond laser are now routinely used to produce energetic particles and photons via interaction with solid targets. However, the relatively low conversion efficiency of such processes requires the use of high repetition rate laser to increase the average power of the laser-induced secondary source. Furthermore, for high intensity laser-matter interaction, a high temporal contrast is of primary importance as the presence of a ns ASE pedestal (Amplified Spontaneous Emission) and/or various prepulses may significantly affect the governing interaction processes by creating a pre-plasma on the target surface. We present the characterization of a laser chain based on Ti:Sa technology and CPA technique, which presents unique laser characteristics : a high repetition rate (100 Hz), a high peak power (> 5 TW) and a high contrast ratio (ASE<10(-10)) obtained thanks to a specific design with 3 saturable absorbers inserted in the amplification chain. A deformable mirror placed before the focusing parabolic mirror should allow us to focus the beam almost at the limit of diffraction. In these conditions, peak intensity above 1019W. cm(-2) on target could be achieved at 100 Hz, allowing the study of relativistic optics at a high repetition rate

Identification of novel PAX6 mutations in two families with bilateral aniridia. Mutations in brief no. 167. Online

We report two novel PAX6 mutations in aniridia patients of two Swiss pedigrees (We, Sc) which give rise to different phenotypes. An SSCP analysis of the PAX6 14 exons reveals electrophoretic mobility shifts exclusively in exons 5 and 12 of aniridia patients. As determined by bidirectional sequencing and restriction digest analysis, these shifts are caused by mono-allelic base transitions in exon 5 (c.547C--&gt;T; R44X; We) and intron 12 (IVS12+5G--&gt;A; Sc). Each mutation co-segregates with the trait in the affected family with complete penetrance. The Sc mutation in the splicing donor site of intron 12 may result in either intron inclusion or exon skipping, both giving rise to a truncated PAX6 protein which may retain a residual transactivating activity. In contrast, the We genetic alteration is a loss-of-function mutation leading to a more severe phenotype than that observed in the Sc pedigree

Complete characterization of damage threshold in titanium doped sapphire crystals with nanosecond, picosecond and femtosecond laser pulses

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