Tag Archives: Evento scientifico

    Overview The objective of LODES is to carry out a study and deliver a report on enablers, obstacles, policies and recommendations for the setup of a cross-country federation of standard-based, multi-domain Linked Open Data repositories leveraging as well as addressing the concept of Open Science. The workshop is linked to work that the OECD Global Science Forum is carrying out on Open Data. The participation is free but the registration through the online registration form is required. We invite participants to register by the deadline of August 25th. We also suggest to take care of the hotel accommodation as soon as possible (see the Accommodation page for more information). The workshop will be held in the Bruno Touschek Auditorium (bldg. n. 36) of the Laboratori Nazionali di Frascati (LNF) of INFN. See LNF Map. This page has  URL http://agenda.infn.it/event/lodes2018 For an immediate view of the agenda go to https://agenda.infn.it/conferenceOtherViews.py?confId=15716&view=standard

Intense femtosecond laser pulses, spanning a large range of photon energies from the X-ray to the THz regime, allow for controlled excitations (“pump”) and monitoring (“probe”) of the nonequilibrium dynamics of all the relevant microscopic degrees of freedom in solids. The field of ultrafast materials science is currently evolving from measuring time constants – for instance for the decay of hot electrons via phonon emission – towards ultrafast laser engineering of nonthermal phases of matter with novel properties. Notable examples include light-induced superconducting-like behavior [1], ultrafast switching to hidden ordered states [2], or time-reversal symmetry-broken Floquet states in topological insulators [3]. I will discuss recent theoretical progress in understanding these diverse phenomena from microscopic models and nonequilibrium simulations. I will show examples of light-enhanced superconductivity in an electron-phonon system from classical nonlinear phononics [4,5] and laser-controlled order competition between superconductivity and charge-density waves [6]. I will discuss laser engineering of microscopic couplings in graphene [7] based on quantum nonlinear phononics [8,9]. I will also show ab initio time-dependent density functional theory results for laser-engineered Hubbard U in NiO [10], with a recent application to light-induce the elusive magnetic Weyl semimetal in pyrochlore iridates [11]. I will also highlight some recent developments towards cavity quantum electrodynamical environments enhancing electron-phonon coupling in 2D materials [12], and efforts to make nonequilbrium Green’s functions fast for correlated ordered phases (excitonic condensates) using the generalized Kadanoff-Baym ansatz [13].

The talk will present the second aspect of the concept – non-specific accumulation of radionuclides by microorganisms based on similarity of ionic radii of radionuclides and metal ions with macro elements. The first part will include an overview about ion interactions with surface cell structures and of mechanisms of ion transport into microbial cells. In the next part will be presented a principle for classification of elements according to similarity of ionic radii and comprehensive table rearranging the periodic table of elements according to this principle. After that, three groups consisting of macro elements and their metal and radionuclide analogues will be discussed in details to understand and analyze mechanisms of non-specific radionuclide accumulation. The last part of the seminar will discuss ways for application of natural mechanisms of ion sorption and transport to provide efficient radionuclide extraction from waste waters and methods for enhancing bioaccumulation capacity in various environmental conditions. Also, few examples of application of combination of microbial non-specific reduction and non-specific accumulation will be given to demonstrate an efficiency of established theoretical approach.

The talk will tell about the fundamentals of the concept – application of electrochemical approach to multi-component systems that include aqueous medium, radionuclides, organic matter and living organisms. These will include explanation of basic electrochemical notions and terminology, analysis of multi-component systems and characteristics of their element as well as detection of their key electrochemical properties. The result of these considerations will be justification of an idea about non-specific nature of microbial/radionuclide redox interactions, which will provide the scope and background for the further in-depth discussion. The second part of the seminar will be dedicated to presentation of the first tool of the concept – Pourbaix diagrams and their adaptation to analysis of radionuclide behavior in biological environment which will include explanation of limits for biological systems, transformation of stability fields into reaction equation towards metal ions and radionuclides, identification of essential conditions for running redox reaction and use of the pH – Eh coordinates to determine the characteristics of the reaction under various environmental conditions. Finally, few examples will be given to demonstrate the application of the approach to detect conditions for non-specific reduction of radionuclides and radioactive metal isotopes.

R&D activity on Cu photo-cathodes is under development at the SPARC_LAB test facility to fully characterize each stage of the photocathode ‘‘life’’ and to have a complete overview of the photoemission properties in high brightness photo-injectors. The nano (n)-machining process presented here consists in diamond milling, and blowing with dry nitrogen. This procedure reduces the roughness of the cathode surface and prevents surface contamination introduced by other techniques, such as polishing with diamond paste or the machining with oil. Both high roughness and surface contamination cause an increase of intrinsic emittance and consequently a reduction of the overall electron beam brightness. To quantify these effects, we have characterized the photocathode surface in terms of roughness measurement, and morphology and chemical composition analysis by means of Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and Atomic Force Microscopy (AFM) techniques. The effects of n-machining on the electron beam quality have been also investigated through emittance measurements before and after the surface processing technique. Finally, we present preliminary emittance studies of yttrium thin film on Cu photo-cathodes.

The design of specific fuel targets represents the crucial point of the Inertial Confinement Fusion scheme. In fact during the laser-matter interaction, due to the irradiation in homogeneities both parametric and hydrodynamic instabilities could be generated, leading to target pre-heating and compression inefficiency. In order to avoid these drawbacks it was considered of interest to coat fusion pellet with light foams, which can act as absorbers of the laser radiation, providing a more homogeneous irradiation and enhancing the efficiency of conversion of laser energy into shock wave energy [1,2]. The presentation will concern the results of 2016 experimental campaign, developed at ENEA research center in Frascati (Rome), in which we studied the behavior of a porous material (Polystyrene Foam) interacting with an high energy Nd laser pulse (duration 3 ns, 30J energy, focal spot dimension 100 µm). From streak camera images we estimated the volume involved in absorption and from the measurement of plasma expansion velocity it was possible to roughly estimate the plasma temperature. With semiconductor detectors we were able to get information about the X-ray emission. In particular we observed that porous materials present an X-ray emission higher than the respective solid material, being comparable to the amount emitted by an Aluminum target. Concerning the density profile, the interferometric images highlighted the presence of second harmonic emission, when irradiating solid material and its absence during the irradiation of porous plastic, which can be symptomatic of a plasma characterized by smoother density gradients [3]. References 1. R. De Angelis, …

The talk will tell about implementation of the theoretical concept for development of processes of radioactive waste water purification and bioremediation of radionuclide-contaminated environment using microorganisms and plants. The first part of the presentation will include analysis of selective accumulation of elements at organism and ecosystem levels in the context of Vernadsky biosphere theory as well as justification an idea that microorganisms are the most efficient bioaccumulating agents. Also, synergic effects of use of several types of organisms for radionuclide extraction will be considered. The second part will summarize concept outputs and discuss their application to overcome the key methodological problems of radioactive water purification. In this part detailed experimental results on microbial extraction of radionuclides from radioactive waste water will be given to demonstrate reliability and efficiency of established approach. The last part will summarize essential conditions for purification of liquid radioactive waste based on electrochemical approach and non-specific interaction (reduction and accumulation) of radionuclides with microorganisms. Finally, bioremediation strategies for radionuclide-contaminated environment and development of plant-microbial artificial ecosystems with the enhanced bioaccumulating capacity will be considered.

The proton is an essential constituent of the visible matter that surround and compose us, but some of its fundamental properties are still not understood. In this seminar, I will focus on Semi-Inclusive Deep Inelastic Scattering (SIDIS) of electrons on an unpolarized target as a way to get information on the proton three dimensional structure in momentum space. I will briefly introduce the theoretical framework that leads to the definition of the Transverse Momentum Partonic Distribution functions (TMDs). I will then consider the processes : ep → eπ±,0X, and ep → eK±X that are being measured at CLAS12 ( Jlab, USA) in a wide kinematic range and with high statistic. An overview of the detector will be given with particular emphasis to its particle identification capability, reached thanks to an innovative Ring Imaging Cherenkov detector realized by the INFN.

In the last two decades, the crucial role played by the high brightness electron beams in the frontier fields of radiation generation and advanced acceleration schemes has been largely established. The design and optimisation of high brightness RF linacs has shown to be essential for the coherent X-rays generation in the FELs as well for the realization of bright Inverse Scattering Compton (ICS) sources, depending the FELs on the electron beam peak brightness and the ICS sources on the electron beam maximum phase space density. These features for the electron beam are achieved thanks to a hybrid scheme consisting in an RF photo-injector followed by booster sections. At the INFN-LNF in Frascati both the ELI-NP Inverse Compton Scattering source, in its installation phase in Magurele (Romenia), and the EuPRAXIA@SPARC_LAB FEL facility are under study. The guidelines to design RF linac able to drive these sources and electron beam dynamics studies for these two machines are here presented.

The new Gamma Beam System (GBS) of the ELI-NP project, currently under installation in Magurele (RO) by INFN, as part of EuroGammaS consortium, can provide tunable gamma rays, with narrow bandwidth (0.3%) and a high spectral density (104 photons/sec/eV) by the Compton backscattering effect. A turn-key high level software has been designed to fully characterise the 6D beam phase space and the trajectory in order to help operator during commissioning with an easily scalable suite for any high brightness LINAC. Currently the high level software, interfaced with EPICS control system, manages automatically accelerator devices to allow electron beam diagnostic measurements (emittance, energy, spread, length, longitudinal profile). Next developments for preserving the beam quality of well-aligned bunch trains will include beam based alignment and dispersion free steering software.