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Knowledge of spatio-temporal couplings such as pulse-front tilt or curvature is important to determine the focused intensity of high-power lasers. Common techniques to diagnose these couplings are either qualitative or require hundreds of measurements. Here we present both a new algorithm for retrieving spatio-temporal couplings, as well as novel experimental implementations. Our method is based on the expression of the spatio-spectral phase in terms of a Zernike-Taylor basis, allowing us to directly quantify the coefficients for common spatio-temporal couplings. We take advantage of this method to perform quantitative measurements using a simple experimental setup, consisting of different bandpass filters in front of a Shack-Hartmann wavefront sensor. This fast acquisition of laser couplings using narrowband filters, abbreviated FALCON, is easy and cheap to implement in existing facilities. To this end, we present a measurement of spatio-temporal couplings at the ATLAS-3000 petawatt laser using our technique.

Contains fulltext : 287473.pdf (Publisher’s version ) (Closed access) CoNEXT '22

Relativistic surface high harmonics have been considered a unique source for the generation of intense isolated attosecond pulses in the extreme ultra-violet (XUV) and X-ray spectral range. However, its experimental realization is still a challenging task requiring identification of the optimum conditions for the generation of isolated attosecond pulses as well as their temporal characterization. Here, we demonstrate measurements in both directions. Particularly, we have made a first step towards the temporal characterization of the emitted XUV radiation by adapting the attosecond streak camera concept to identify the time domain characteristics of relativistic surface high harmonics. The results, supported by PIC simulations, set the upper limit for the averaged (over many shots) XUV duration to

When a rather cold electron bunch is transported during laser bubble acceleration in a strongly focusing plasma channel with typical forces of 100 GeV/m, it will form partially ordered long electron cylinders due to the relativistically longitudinal reduced repulsion between electrons, resulting in a long-range pair correlation function, when reaching energies in the laboratory above 0.5 GeV. During Compton back-scattering with a second laser, injected opposite to the electron bunch, the electron bunch will be further modulated with micro bunches and due to its ordered structure will reflect coherently, M��ssbauer-like, resulting in a ��free electron laser (��-FEL). Increasing the relativistic ��factor, the quantal regime becomes more dominant. We discuss the scaling laws with ��.

Item does not contain fulltext CSEIT 2012 : 3rd Annual International Conference on Computer Science Education: Innovation and Technology, 19-20 November, Singapore

The Vulcan laser at the Rutherford Appleton Laboratory in England has been used to show, for the first time, that picosecond laser generated non-thermal K-alpha radiation can be used effectively as a backlighter for radiographic imaging of an implosion. This novel method of x-ray radiography features high temporal resolution, high signal to noise ratio and monochromatic imaging. We present here the Ti K-alpha backlit images of a series of six-beam driven spherical implosions of thin-walled 500 micron Cu doped CD shells. These images, separated by ∼ 0.5ns intervals, capture various states of implosion in and around a stagnation time observed to be ∼ 3.25 ns. Images of imploding coned Cu doped CD shells used in fast ignition research are additionally presented. These images, taken near the previously determined stagnation time, show an imploded core collapsed around an attached gold laser entry cone. These radiographic results were linked to a study of fast electron transport within imploded Cu doped coned CD shells as a result of interaction with a high intensity, short pulse laser. The radiographic results, then, served as a verification of a smooth and uniform implosion and provided an empirical determination of stagnation time, both prerequisites for the electron transport diagnosis.

We present the first systematic measurement of the transverse parameters of laser produced proton beam. We find a similarity for the shape of the accelerating sheath, which is always close to a parabola. We find also a similarity for the relation between source size and proton energy with the maximum source size and proton energy as a free parameter, which is confirming the similarity we already found for the sheath shape. This is of particular interest for the application of laser produced proton beams as it shows the scalability of the transverse beam parameter.

Laser-wakefield-accelerated electrons were used to drive an all-optical undulator source, a 5-keV betatron X-ray source and a tunable quasi-monochromatic Compton-X-ray source. Also, we present a phase-contrast tomogram of a fly obtained with the betatron beam. © 2014 OSA.