5,040 research outputs found
Comment on: "Neutron driven fusion" [Phys. Lett. A 334 (2005) 42]
No full textIt is shown that the scheme suggested by R.L. Liboff [Phys. Lett. A 334 (2005) 42] cannot lead to significant energy production by fusion reactions. A modest energy release (less than 1% of the value claimed by Liboff) is obtained from the reaction n + Li-6 -> T + He-4 + 4.78 MeV, while fusion reactions only occur at negligible rate. (c) 2005 Elsevier
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Comments on: "Neutron driven fusion" [Phys. Lett. A 334 (2005) 42]
Author(s): Atzeni, S (Atzeni, S)
Source: PHYSICS LETTERS A Volume: 342 Issue: 1-2 Pages: 196-197 DOI: 10.1016/j.physleta.2005.05.047 Published: JUL 4 2005
Times Cited: 0 (from Web of Science)
Cited References: 9 [ view related records ] Citation Map
Abstract: It is shown that the scheme suggested by R.L. Liboff [Phys. Lett. A 334 (2005) 42] cannot lead to significant energy production by fusion reactions. A modest energy release (less than 1% of the value claimed by Liboff) is obtained from the reaction n + Li-6 -> T + He-4 + 4.78 MeV, while fusion reactions only occur at negligible rate. (c) 2005 Elsevier B.V. All rights reserved
Assessing target design robustness for shock ignition using 3D laser raytracing
No full textShock ignition (SI)[1] is a laser direct-drive Inertial Confinement Fusion scheme in which fuel compression and hot spot formation are separated. Shock ignition shows potential for high gain at laser energy below 1 MJ (see review Ref.[2]), and could be tested on present large scale facilities. We produced an analytical model for SI which allows rescaling of target and laser drive parameters starting from a given point design [3]. The goal is to redefine a laser-target configuration increasing the robustness while preserving its performance. We developed a metric for ignition margins specific to SI [4]. We report on simulations of rescaled targets using 2D hydrodynamic fluid model with 3D laser raytracing. The robustness with respect to target fabrication parameters and laser facility fluctuations will be assessed for an original reference design as well as for a rescaled target, testing the accuracy of the ignition margin predictor just developed. Work supported by the Italian MIUR project PRIN2012AY5LEL.
[1] R. Betti, C.D. Zhou et al, PRL 98, 155001 (2007)
[2] S. Atzeni, X. Ribeyre et al, Nucl. Fusion 14, 054008 (2014)
[3] S. Atzeni, A. Marocchino, A. Schiavi and G. Schurtz, New J. Phys. 15, 045004 (2013) [4] S. Atzeni, A. Marocchino, A. Schiavi, EPS Conf. proc. submitted to PPCF (2014
A GPU based 3D raytracing algorithm for DUED laser fusion code
No full textThese days, graphical processing units (GPUs) deliver performance comparable to that of hundreds of CPU cores. This level of performance allows certain classes of simulations to be run in-house on a standard consumer workstation, eliminating the need for a cluster. In this paper, it is shown that medium-resolution, 2D radiation hydrodynamics simulations for laser-driven inertial confinement fusion with realistic 3D laser raytracing can now be conducted on a single consumer device. A novel raytracing module has indeed been developed for the 2D Lagrangian radiation-hydro-nuclear code DUED (Atzeni 1986 Comput. Phys. Commun. 43 107–24; Atzeni et al 2005 Comput. Phys. Commun. 169 153–9) to leverage the computational power of GPUs. By employing 3D raytracing, more realistic investigations of laser-driven plasmas become feasible, with a particular focus on perturbations resulting from non-uniform laser irradiation
Appunti sul racconto storico in Atzeni.
No full textIl saggio prende in esame la poetica di Sergio Atzeni e la sua concezione del racconto storico
Edward Teller Medal
No full textPremio in
"Recognition of pioneering research and leadership in Inertial Fusion and Applications"
Citation:
"Professor Atzeni is being honored because of his leading contributions to understanding and teaching the high energy density physics related to Inertial Confinement Fusion. His contributions to development of the isobaric gain model and to modeling fluid instabilities and mixing are notable. His publications span a broad range of physics issues including implosion symmetry and instabilities, thermonuclear burn, and fast ignition. Professor Atzeni is an outstanding teacher and has lectured on high energy density physics in several European countries and in Japan.
Cromatismo, ritmo, memoria: sulla narrativa di Sergio Atzeni
No full textSergio Atzeni’s works are many and really heterogeneous, both in style and contents. But if we dig up deeply into his texts, we discover that the currents followed by the author are always the same, and that texts that are apparently different have actually significant common aspects.Le opere di Sergio Atzeni sono numerose e molto eterogenee, sia nello stile che nei contenuti. Ma se andiamo a scavare nel profondo, ci rendiamo conto che i filoni seguiti dall’autore sono sempre gli stessi, e che esiti testuali apparentemente distinti hanno in realtà importanti aspetti in comune
Dispositivi allegorici e esiti fiabeschi nei romanzi di Sergio Atzeni
No full textSono passati oltre vent'anni dalla scomparsa dello scrittore Sergio Atzeni (1952-1995), ma la sua opera, radicata profondamente nella tradizione sarda e insieme aperta all'innovazione e al dialogo con la cultura contemporanea internazionale, continua ad avere una fortissima presenza in Sardegna e a suscitare un ampio interesse in Italia e all'estero. Questo volume, composto di quindici capitoli firmati da scrittori e da studiosi attivi in università italiane e straniere, indaga molti aspetti della scrittura di Atzeni: le relazioni con la letteratura e la politica sarda, con la tradizione letteraria italiana e con fenomeni culturali internazionali; il ricorso alle tecniche allegoriche e la riflessione sui rapporti fra storia e narrativa; i dialoghi con la musica e con il cinema; i caratteri tematici, strutturali e stilistici delle sue opere
Perspectives for inertial fusion
No full textThe quest for demonstrating ignition and gain in Inertial Confinement Fusion [1] has come to a crucial point, where the long awaited
proof of principle of this approach to fusion still fails to arrive. We present the status of this field of research, both at the international
[2] and european level [3], focussing on the standard approach and on the new strategies in laser fusion.
The path ahead is also indicated, highlighting some of the key points in the design of a fusion reactor. The recent results obtained by
our group on target design for shock ignition [4], optimization of direct-drive irradiation schemes [5], and energy and laser
wavelength scaling models are illustrated [6].
[1] J.D. Lindl, Physics of Plasmas 2, 3933 (1995).
[2] J.D. Lindl, E.I. Moses, Physics of Plasmas 18, 050901 (2011).
[3] M. Dunne, Nature Physics 2, 2 (2006).
[4] S. Atzeni, A. Schiavi, A. Marocchino, Plasma Physics and Controlled Fusion 53, 35010 (2011).
[5] A. Schiavi, S. Atzeni, A. Marocchino, Europhysics Letters 94, 35002 (2011).
[6] S. Atzeni, A. Marocchino, A. Schiavi, G. Schurtz, New J. of Physics 15, 045004 (2013)
Self piercing riveting for metal-polymer joints
No full textSelf-Piercing Riveting (SPR) is a sheet metal joining technique based on the insertion of a rivet into two or more sheets, with no preparatory hole. This process has gained wide diffusion in the automotive industry, due to the increasing use of materials alternative to steel, that are difficult or impossible to join with traditional techniques. In particular, polymeric materials are becoming increasingly used, due to their favorable weight/strength ratio. This paper reports the results of experimental investigations, aimed at identifying the variables affecting the mechanical characteristics of mixed metal-plastic joints. A statistic model for the optimization of the geometrical parameters has been computed. The paper demonstrates that self-piercing riveting appears competitive for metal/polymer junction. The results analyzed in light of statistical techniques show that some geometrical parameters affect joint performance more than others and can therefore be used as independent variables for joint performance optimizatio
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