Advanced instrumentation for spectral and spatial investigations of high-order laser harmonics

We report on the design and characterization of a grazing-incidence flat-field spectrograph that allows simultaneously the measurement of spectrum, beam divergence, and absolute flux of EUV and soft X-ray radiation for a beam of high-order laser harmonics generated by the interaction between an ultrashort femtosecond laser pulse and a gas jet. The instrument seems a very powerful tool for the understanding of the generation process

Integrated Numerical Models in Coastal Areas: An Example of Their Application in the North Adriatic Sea

Recent decades have witnessed considerable developments in the field of integrated numerical models used for simulating dynamic processes in coastal areas, that can now provide quantitative support to decision makers for questions such as erosion and coastal vulnerability. Improvements in various theoretical formulations and an on-going increase in computing power (alongside the growing availability of long-term observations and numerical output from meteorological and sea-state models) allow the implementation of high-resolution and long-term applications.However, the efficient use of these numerical tools is a function of their capacity to describe a variety of physical processes that are ‘integrated’ amongst themselves correctly. Indeed, from the air-sea interface to the turbulent mixing of water masses and the water-sediment interaction, integrated numerical modelling has to face a series of scientific and practical challenges still open. Examples include the non-linear interaction of waves and currents, the problem of turbulence, the modelling of resuspension and sediment-transport processes, the role of longperiod waves in generating beach and dune erosion. Dealing with these using numerical models is necessary for a variety of reasons, from protecting the coast to search-and-rescue activities and support for marine construction work of all types

Laser-produced plasma stigmatic observations in the EUV by means of a CCD detector with enhanced VUV sensitivity

The observations of the emission from laser-produced plasmas of carbon, aluminum and tungsten have been performed by means of a vacuum normal incidence stigmatic spectrograph. The detector used is a Peltier-cooled CCD, optimized for the vacuum ultraviolet spectral range. The results presented include the spectrum of the plasmas, in the range from 380 to 800 angstrom, the spectral and spatial profiles along the expanding plasmas and the absolute measurements of the plasma brightness. The measurements show an outstanding capability of this type of detector, in terms of sensitivity, resolution and dynamic range, with respect to traditional devices such as photographic film, intensified linear arrays, and CCD

Laser-produced plasma stigmatic observations in the extreme ultraviolet by means of a CCD detector

Observations of the emission from laser-produced plasmas of carbon, aluminum and tungsten have been performed by means of a vacuum normalincidence stigmatic spectrograph. The detector used is a Peltier-cooled CCD, particularly treated so to be sensitive in the vacuum ultraviolet spectral range. The presented results include the spectrum emitted, in the range from 380 to 800 \uc5, with spectral and spatial profiles along the expanding plasmas and absolute measurements of the plasma brightness. The measurements show an outstanding capability of this type of detector, in terms of sensitivity, resolution and dynamic range, with respect to traditional devices, for UV detection, as photographic film, intensified linear arrays and scintillator coated CCDs