51 research outputs found
Characterization and Application of Hard X-Ray Betatron Radiation Generated by Relativistic Electrons from a Laser-Wakefield Accelerator
The necessity for compact table-top x-ray sources with higher brightness,
shorter wavelength and shorter pulse duration has led to the development of
complementary sources based on laser-plasma accelerators, in contrast to
conventional accelerators. Relativistic interaction of short-pulse lasers with
underdense plasmas results in acceleration of electrons and in consequence in
the emission of spatially coherent radiation, which is known in the literature
as betatron radiation. In this article we report on our recent results in the
rapidly developing field of secondary x-ray radiation generated by high-energy
electron pulses. The betatron radiation is characterized with a novel setup
allowing to measure the energy, the spatial energy distribution in the
far-field of the beam and the source size in a single laser shot. Furthermore,
the polarization state is measured for each laser shot. In this way the emitted
betatron x-rays can be used as a non-invasive diagnostic tool to retrieve very
subtle information of the electron dynamics within the plasma wave. Parallel to
the experimental work, 3D particle-in-cell simulations were performed, proved
to be in good agreement with the experimental results.Comment: 38 pages, 19 figures, submitted to the Journal of Plasma Physic
Experimental investigation of fast electron transport in solid density matter: Recent results from a new technique of X-ray energy-encoded 2D imaging
AbstractThe development activity of a new experimental technique for the study of the fast electron transport in high density matter is reported. This new diagnostic tool enables the X-ray 2D imaging of ultrahigh intensity laser plasmas with simultaneous spectral resolution in a very large energy range to be obtained. Results from recent experiments are discussed, in which the electron propagation in multilayer targets was studied by using the Kα. In particular, results highlighting the role of anisotropic Bremsstrahlung are reported, for the sake of the explanation of the capabilities of the new diagnostics. A discussion of a test experiment conceived to extend the technique to a single-shot operation is finally given
Spatially resolved twin domain distribution and lattice parameter variations in the near-surface region of SrTiO_3 single crystals
Soft-x-ray imaging with toroidally curved thallium acid phthalate crystals in the water window
Vacuum birefringence at x-ray free-electron lasers
We study the perspectives of measuring the phenomenon of vacuum birefringence
predicted by quantum electrodynamics using an x-ray free-electron laser (XFEL)
alone. We devise an experimental scheme allowing the XFEL beam to collide with
itself under a finite angle, and thus act as both pump and probe field for the
effect. The signature of vacuum birefringence is encoded in
polarization-flipped signal photons to be detected with high-purity x-ray
polarimetry. Our findings for idealized scenarios underline that the discovery
potential of solely XFEL-based setups can be comparable to those involving
optical high-intensity lasers. For currently achievable scenarios, we identify
several key details of the x-ray optical ingredients that exert a strong
influence on the magnitude of the desired signatures.Comment: 26 pages, 2 figure
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