Propagation of ultrastrong femtosecond laser pulses in PLASMON-X

The derivation is presented of the nonlinear equations that describe the propagation of ultrashort laser pulses in a plasma, in the Plasmon-X device. It is shown that the Plasmon-X scheme used for the electron acceleration uses a sufficiently broad beam ($L_\bot\sim 130\,\,\mu{\rm m}$) that justifies the use of the standard stationary 1-D approximation in the electron hydrodynamic equations, since the pulse width is sufficiently bigger than the pulse length ($\sim 7.5\,\,\mu{\rm m}$). Furthermore, with the laser power of $W\leq 250$ TW and the $130\,\,\mu{\rm m}$ spot size, the dimensionless laser vector potential is sufficiently small $|A_{\bot_0}|^2/{2} = ({W}/{c^2\epsilon_0})({\lambda^2}/{8 \pi^2 c})({4}/{\pi L_\bot^2})({e}/{m_0 c})^2 \sim 0.26$, the nonlinearity is sufficiently weak to allow the power expansion in the nonlinear Poissons's equation. Such approximation yields a nonlinear Schr\" odinger equation with a reactive nonlocal nonlinear term. The nonlocality contains a cosine function under the integral, indicating the oscillating wake. For a smaller spot size that is used for the Thomson scattering, $L_\bot = 10\,\, \mu$m, the length and the width of the pulse are comparable, and it is not possible to use the 1-D approximation in the hydrodynamic equations. With such small spot size, the laser intensity is very large, and most likely some sort of chanelling in the plasma would take place (the plasma gets locally depleted so much that the electromagnetic wave practically propagates in vacuum).Comment: Oral contribution O3.205 delivered at the 38th EPS Conference on Plasma Physics, Strasbourg, France, 26 June - 1 July, 201

Local production and innovation systems in the state of São Paulo, Brazil

This paper applies a specific methodology to geographically locate and delimit local production and innovation systems in the state of São Paulo. A first task, and a bulk part of the paper, is the elaboration of a number of quantitative indicators for the geographic concentration of manufacturing industries and for the location of industries at regional and local levels in that state. The elaboration of indices and other indicators for measuring regional location and specialization of economic activities is an old practice and has been an important object of study in regional economics since the seminal contributions by the pioneers of Regional Science. However, the statistical work developed in this paper is based on two most important recent contributions by P. Krugman (in Geography and Trade, 1991) and D. B. Audretsch & M. Feldman (in R&D spillovers and the geography of innovation and production, The American Economic Review, 86 (3), 1996). These authors calculated locational Gini coefficients for branches of U. S. manufacturing industry (Krugman) and for the geographic concentration of innovative activities and the location of U. S. manufacturing industries (Audretsch & Feldman). This paper applies the same methodology to calculate locational Gini coefficients for manufacturing industries in the state of São Paulo, the most advanced state in Brazilian industrialization. The Gini coefficients were calculated from data in RAIS - Relação Anual de Informações Sociais, elaborated by the Brazilian Ministry of Labor. This database provides detailed information on employment and number of plants by branches of manufacturing industries at micro-region and municipality levels. On the basis of the locational Gini coefficients the paper assesses which manufacturing industries are mostly spatially concentrated. Once these industries are identified, the paper proceeds by adding other indicators such as locational quotients, share of the local industry in the total manufacturing employment in the state, number of jobs and number of plants in the local industry. Combined, the Gini coefficients and the other indicators allow to identify, locate, and geographically delimit local production and innovation systems. Additionally, they make it possible to assess to what extent the local system is integrated. These findings are essential for guiding field research and, afterwards, for designing policies oriented to local production and innovation systems.

Knowledge, Innovation and Agglomeration - regionalized multiple indicators and evidence from Brazil

This paper develops multiple indicators to map the geographical distribution of knowledge and scientific and technological capabilities as proxies of the geographical distribution of Science, Technology & Innovation activities, and applies such indicators to data and information from the state of São Paulo, Brazil. The overall view of the geographical distribution of S,T&I activities in the state is complemented by the analysis of the same activities in the perspective of a local production and innovation system: the case of information and communication technologies in the micro-region of Campinas. The results show a pattern for the regional distributions of S,T&I activities along the main highways of the state, around metropolitan areas such as São Paulo and Campinas, and in regions where educational, science and technology, and R&D institutions are strongly concentrated. Firms tend to agglomerate in these areas and regions, forming local production and innovation systems. The paper produces evidence on the adherence of the geographical distribution of those systems to the geographical distribution of S,T&I activities as shown by the indicators. This confirms the empirical findings of the literature about the relationship between geography and innovation.

Cyclic-time granularity based decomposition approach for multi-seasonal time-series and its use on a data management and analysis backbone for Peruvian data about exports

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Self consistent thermal wave model description of the transverse dynamics for relativistic charged particle beams in magnetoactive plasmas

Thermal Wave Model is used to study the strong self-consistent Plasma Wake Field interaction (transverse effects) between a strongly magnetized plasma and a relativistic electron/positron beam travelling along the external magnetic field, in the long beam limit, in terms of a nonlocal NLS equation and the virial equation. In the linear regime, vortices predicted in terms of Laguerre-Gauss beams characterized by non-zero orbital angular momentum (vortex charge). In the nonlinear regime, criteria for collapse and stable oscillations is established and the thin plasma lens mechanism is investigated, for beam size much greater than the plasma wavelength. The beam squeezing and the self-pinching equilibrium is predicted, for beam size much smaller than the plasma wavelength, taking the aberrationless solution of the nonlocal Nonlinear Schroeding equation.Comment: Poster presentation P5.006 at the 38th EPS Conference on Plasma Physics, Strasbourg, France, 26 June - 1 July, 201

Soliton solutions of 3D Gross-Pitaevskii equation by a potential control method

We present a class of three-dimensional solitary waves solutions of the Gross-Pitaevskii (GP) equation, which governs the dynamics of Bose-Einstein condensates (BECs). By imposing an external controlling potential, a desired time-dependent shape of the localized BEC excitation is obtained. The stability of some obtained localized solutions is checked by solving the time-dependent GP equation numerically with analytic solutions as initial conditions. The analytic solutions can be used to design external potentials to control the localized BECs in experiment.Comment: 11 pages, 5 figures, submitted to Phys. Rev.