An overview on armor research for the laser fusion project HiPER

During the current preparatory phase of the European laser fusion project HiPER, an intensive effort has being placed to identify an armour material able to protect the internal walls of the chamber against the high thermal loads and high fluxes of x-rays and ions produced during the fusion explosions. This poster addresses the different threats and limitations of a poly-crystalline Tungsten armour. The analysis is carried out under the conditions of an experimental chamber hypothetically constructed to demonstrate laser fusion in a repetitive mode, subjected to a few thousand 48MJ shock ignition shots during its entire lifetime. If compared to the literature, an extrapolation of the thermomechanical and atomistic effects obtained from the simulations of the experimental chamber to the conditions of a Demo reactor (working 24/7 at hundreds of MW) or a future power plant (producing GW) suggests that “standard” tungsten will not be a suitable armour. Thus, new materials based on nano-structured W and C are being investigated as possible candidates. The research programme launched by the HiPER material team is introduced

Study of interfacial stiffness ratio of a rough surface in contact using a spring model

This study proposes the use of a simple spring model that relates the interfacial stiffness with the complex reflection coefficient of ultrasound in a rough contact. The spring model cannot be directly related to the real area of contact as this depends on the amount, shape and distribution of contacting asperities. However, it is clear that the model provides a non-destructive tool to easily evaluate both longitudinal and shear interfacial stiffnesses and their ratio. Experimental findings indicate that the interfacial stiffness ratio K-tau/K-sigma determined during loading/unloading cycles is sensitive to the roughness level and load hysteresis. The results deviate from the theoretical available micromechanical models, indicating that actual contacting phenomenon is more complex and other variables needed are not accounted for by the models. (C) 2009 Elsevier B.V. All rights reserved

Contribution From Optical Course For The Educational Guidance Of Engineering Careers Students

The work shows the fundamental elements of an inclusive educational guidance conception of substantive university processes and results achieved at the Instituto Superior Politécnico José Antonio Echeverría of Havana in the contribution from optical course to develop it for the students in first and second year of the engineering programs, by means of lectures on holography and three-dimensional images of motivation and link with different specialties and the development of experimental facilities and methodology for the construction of holograms and anaglyph by students for engineering applications.9289 IEEE - The Photonics Society,International Commission for Optics (ICO),The Optical Society,The Society of Photo-Optical Instrumentation Engineers (SPIE)Collazo, B., Puentes, M., La orientacin en la actividad pedaggica ¿el maestro, un orientador? (1992) Editorial Pueblo y Educacin, , La HabanaCollazo, B., (2006) Modelo de Tutora Integral Para la Continuidad de Estudios Universitarios en Las Sedes Municipals, , Tesis de doctorado CubaRodrguez, S., (1997) Orientacin Universitaria y Evaluacin de la Calidad. Calidad de la Universidad: Orientacin y Evaluacin, , Apodaca P. y C. Lobato Eds, Barcelona, LaertesEcheverra, B., (1997) Los servicios de orientacin universitarios. Calidad en la universidad: Orientacin y evaluacin, pp. 112-136. , Apodaca P. y C. Lobato (Eds, Barcelona: LaertesMonge, M.C., (2009) Tutora y Orientacin Educative, , Nuevas competencies Las Rozas Wolters KluwerSantana, L.E., (2009) Orientacin Educativa e Intervencin Psicopedaggica Cambian Los Tiempos Cambian Las Responsabilidades Profesionales, , Pirmide MadridVieira, M.J., Vidal, J., Tendencias de la Educacin Superior Europea e implicaciones para la orientacin universitaria (2006) Revista Espaola de Orientacin y Psicopedagoga, 17 (1), pp. 75-97Jaime, R.A., La orientacin educativa como tarea inseparable de la Extensin Universitaria (2011) Revista Cuadernos de Educacin y Desarrollo, 3 (28)Daz, T., La Extensin: Un proceso formativo de la Universidad. Su relacin con otros procesos (2001) Conferencia Magistral Del VI Taller Internacional de Extensin Universitaria, , Memorias, CubaGonzlez, G., (2002) Extensin Universitaria: Una Visin un Cambio Necesario, , Conferencia de la III Convencin Internacional de Educacin Superior, Memorias, CubaOliveira, N., The notorial dynamic analisis of an artificial satellite: A pedagogical experiment in space education (2008) Revista Brasileira de Ensino de Fsica, 30 (1), p. 1401Serra, R., Alfonso, I., Herrera, R., Ferreira, D., Muramatsu, M., Soga, D., (2013) La Fsica y El Trabajo Cientfico Estudiantil en la formación Del Ingeniero Biomdico, , enviado a LAJFE en proceso de arbitraje, eneroSerra, R., (2004) La Utilizacin Del Holograma Como Medio de Enseñanza y de Educacin Social en Cuba A Travs Del Vnculo Investigación-Docencia-Extensin Universitaria, , Tesis Doctoral CubaSerra, R., Moreno, A., Magalhes, D., Muramatsu, M., Lemus, J., Haciendo hologramas en la escuela y en la casa (2010) Revista Brasileira de Ensino de Fsica, 32 (3), p. 3502Zottola, D., Hernndez, A., Serra, R., Anaglifos en la Enseñanza de la ingeniera biomdica (2011) Proc. of v Latin American Congress on Biomedical Engineering, , Haban

Temperature Evolution and Light Species Diffusion in Armor and Structural Material for Inertial Fusion Reactor Chambers: a Case for HiPER 4a

One of the most advance designs for HiPER fusion reactor is a spherical chamber 10 m in diameter based on dry wall concept. In this system, the first wall will have to withstand short energy pulses of 5 to 20 MJ at a repetition rate of 0.5-10 Hz mostly in form of X-rays and charged particles. To avoid melting of the inner surface, the first wall consists on a thin armor attached to the structural material. Thickness (th) and material of each layer have to be chosen to assure the proper functioning of the facility during its planned lifetime

Probing Non-Standard Couplings of Neutrinos at the Borexino Detector

The present experimental status does not exclude weak-strength non-standard interactions of neutrinos with electrons. These interactions can be revealed in solar neutrino experiments. Our discussion covers several aspects related to this issue. First, we perform an analysis of the Super Kamiokande and SNO data to investigate their sensitivity to such interactions. In particular, we show that the \nu_e oscillation into sterile neutrinos can be still allowed if \nu_e has extra interactions of the proper strength. Second, we suggest that the Borexino detector can provide good signatures for these non-standard interactions. Indeed, in Borexino the shape of the recoil electron spectrum from the \nu e \to \nu e scattering essentially does not depend on the solar neutrino conversion details, since most of the signal comes from the mono-energetic ^7Be neutrinos. Hence, the partial conversion of solar \nu_e into a a nearly equal mixture of \nu_\mu and \nu_\tau, as is indicated by the atmospheric neutrino data, offers the chance to test extra interactions of \nu_\tau, or of \nu_e itself.Comment: 17 LaTeX pages, 15 postscript figures, uses epsfig.sty. More extended discussion about the spectral deformation for both Super-Kamiokande and Borexino; new figures are adde

Validity of the Generalized Second Law of Thermodynamics of the Universe Bounded by the Event Horizon in Holographic Dark Energy Model

In this letter, we investigate the validity of the generalized second law of thermodynamics of the universe bounded by the event horizon in the holographic dark energy model. The universe is chosen to be homogeneous and isotropic and the validity of the first law has been assumed here. The matter in the universe is taken in the form of non-interacting two fluid system- one component is the holographic dark energy model and the other component is in the form of dust.Comment: 8 page

Properties of hyperkahler manifolds and their twistor spaces

We describe the relation between supersymmetric sigma-models on hyperkahler manifolds, projective superspace, and twistor space. We review the essential aspects and present a coherent picture with a number of new results.Comment: 26 pages. v2: Sign mistakes corrected; Kahler potential explicitly calculated in example; references added. v3: Published version--several small clarifications per referee's reques

Robust signatures of solar neutrino oscillation solutions

With the goal of identifying signatures that select specific neutrino oscillation parameters, we test the robustness of global oscillation solutions that fit all the available solar and reactor experimental data. We use three global analysis strategies previously applied by different authors and also determine the sensitivity of the oscillation solutions to the critical nuclear fusion cross section, S_{17}(0), for the production of 8B. The favored solutions are LMA, LOW, and VAC in order of g.o.f. The neutral current to charged current ratio for SNO is predicted to be 3.5 +- 0.6 (1 sigma), which is separated from the no-oscillation value of 1.0 by much more than the expected experimental error. The predicted range of the day-night difference in charged current rates is (8.2 +- 5.2)% and is strongly correlated with the day-night effect for neutrino-electron scattering. A measurement by SNO of either a NC to CC ratio > 3.3 or a day-night difference > 10%, would favor a small region of the currently allowed LMA neutrino parameter space. The global oscillation solutions predict a 7Be neutrino-electron scattering rate in BOREXINO and KamLAND in the range 0.66 +- 0.04 of the BP00 standard solar model rate, a prediction which can be used to test both the solar model and the neutrino oscillation theory. Only the LOW solution predicts a large day-night effect(< 42%) in BOREXINO and KamLAND. For the KamLAND reactor experiment, the LMA solution predicts 0.44 of the standard model rate; we evaluate 1 sigma and 3 sigma uncertainties and the first and second moments of the energy spectrum.Comment: Included predictions for KamLAND reactor experiment and updated to include 1496 days of Super-Kamiokande observation

Homestake result, sterile neutrinos and low energy solar neutrino experiments

The Homestake result is about ~ 2 \sigma lower than the Ar-production rate, Q_{Ar}, predicted by the LMA MSW solution of the solar neutrino problem. Also there is no apparent upturn of the energy spectrum (R \equiv N_{obs}/N_{SSM}) at low energies in SNO and Super-Kamiokande. Both these facts can be explained if a light, \Delta m^2_{01} ~ (0.2 - 2) \cdot 10^{-5} eV^2, sterile neutrino exists which mixes very weakly with active neutrinos: \sin^2 2\alpha ~ (10^{-5} - 10^{-3}). We perform both the analytical and numerical study of the conversion effects in the system of two active neutrinos with the LMA parameters and one weakly mixed sterile neutrino. The presence of sterile neutrino leads to a dip in the survival probability in the intermediate energy range E = (0.5 - 5) MeV thus suppressing the Be, or/and pep, CNO as well as B electron neutrino fluxes. Apart from diminishing Q_{Ar} it leads to decrease of the Ge-production rate and may lead to decrease of the BOREXINO signal and CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO and KamLAND as well as by the new low energy experiments will allow us to check this possibility. We present a general analysis of modifications of the LMA energy profile due to mixing with new neutrino states.Comment: Figures 5 and 6 modified, shorter version will be published in PR

Kinetics and Jamming Coverage in a Random Sequential Adsorption of Polymer Chains

Using a highly efficient Monte Carlo algorithm, we are able to study the growth of coverage in a random sequential adsorption (RSA) of self-avoiding walk (SAW) chains for up to 10^{12} time steps on a square lattice. For the first time, the true jamming coverage (theta_J) is found to decay with the chain length (N) with a power-law theta_J propto N^{-0.1}. The growth of the coverage to its jamming limit can be described by a power-law, theta(t) approx theta_J -c/t^y with an effective exponent y which depends on the chain length, i.e., y = 0.50 for N=4 to y = 0.07 for N=30 with y -> 0 in the asymptotic limit N -> infinity.Comment: RevTeX, 5 pages inclduing figure