bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing French syllabification in preliterate children and adults
Authors: GOSLIN JEREMY , FLOCCIA CAROLINE
Published: April 2008

The influence of development and literacy upon syllabification in French was evaluated by comparing the segmental behavior of 4- to 5-year-old preliterate children and adults using a pause insertion task. Participants were required to repeat bisyllabic words such as “fourmi” (ant) by inserting a pause between its two syllabic components (/fur/-/mi/). In the first experiment we tested segmentation over a range of 49 double intervocalic consonant clusters. A similar general segmentation behavior was observed in both age groups, with a pattern that fit the predictions from a legality principle-based model of syllabification. Experiment 2 revealed that opacity between phonological and orthographic representations lead to increased ambisyllabic responses and a reduction in segmentation consistency in adults. In total, these findings indicate that syllabic forms are consistently represented from an early age, but that segmentation in metalinguistic tasks is susceptible to contamination from spelling and etymological knowledge.
Cross-linguistic transfer and borrowing in bilinguals
Authors: MARIAN VIORICA , KAUSHANSKAYA MARGARITA
Published: April 2008

Cross-linguistic borrowing (overt use of words from the other language) and transfer (use of semantic or syntactic structures from the other language without active switching to that language) were examined during language production in Russian–English bilinguals. Grammatical category (noun/verb) and level of concreteness were found to influence language interaction. More cross-linguistic borrowings were found for nouns than for verbs and more cross-linguistic transfers were found for verbs than for nouns, suggesting that grammatical categories are differentially vulnerable to covert and overt language interaction. Moreover, concrete nouns and verbs were transferred more than abstract nouns and verbs, suggesting that level of concreteness influences lexical access in bilinguals. Overall, bilinguals transferred more when speaking their second and less proficient language and borrowed more when speaking their first and less recent language (especially if the described event took place in the other language). We suggest that language architecture (e.g., semantic representation, lexical access) and language environment influence the nature of cross-linguistic interaction.
Dynamique du pseudo-groupe des isométries locales sur une variété Lorentzienne analytique de dimension 3
Authors: DUMITRESCU SORIN
Published: April 2008

Soit (M,g) une variété lorentzienne analytique réelle de dimension 3 compacte et connexe. Nous démontrons que l’existence d’une orbite ouverte (non vide) du pseudo-groupe des isométries locales implique que la métrique lorentzienne est localement homogène (i.e. le pseudo-groupe des isométries locales de g agit transitivement sur M).
Proper minimal sets on compact connected 2-manifolds are nowhere dense
Authors: KOLYADA SERGII˘ , SNOHA L’UBOMÍR , TROFIMCHUK SERGEI˘
Published: April 2008

Let $\mathcal {M}^2$ be a compact connected two-dimensional manifold, with or without boundary, and let $f:{\mathcal {M}}^2\to \mathcal {M}^2$ be a continuous map. We prove that if $M \subseteq \mathcal {M}^2$ is a minimal set of the dynamical system $(\mathcal {M}^2,f)$ then either $M = \mathcal {M}^2$ or M is a nowhere dense subset of $\mathcal {M}^2$. Moreover, we add a shorter proof of the recent result of Blokh, Oversteegen and Tymchatyn, that in the former case $\mathcal {M}^2$ is a torus or a Klein bottle.
New Approaches to Global Labor History
Authors: Hanagan Michael , van der Linden Marcel
Published: April 2008

Employing innovative methods and new approaches to global labor history, the six essays in this collection explore important aspects of labor's role in global capitalism since the early modern period. Essays by Jan Lucassen and Jeffrey D. Glasco study the commercial agents, soldiers, and sailors that constituted the institutional framework for the global expansion of Western capitalism. Essays by Julie Greene and by Donna Gabaccia, Franca Iacovetta, and Fraser Ottanelli concentrate on workers who entered the international labor markets of the nineteenth and twentieth centuries. They show how employers attempted to use migrants to promote stratification within the working classes and how workers responded to these efforts by trying to fashion their own identities. Finally, essays by Josie Fowler and Victor Silverman investigate the international organizations created by labor movements, responding to global capitalism, and illustrate how these organizations have shaped the development of the labor movement.
Laboring Across National Borders: Class, Gender, and Militancy in the Proletarian Mass Migrations
Authors: Gabaccia Donna , Iacovetta Franca , Ottanelli Fraser
Published: April 2008

A decade-long project on the migration of Italian laborers around the world during the nineteenth and twentieth centuries points to the methodological challenges, theoretical debates, and some of the rewards of transnational analysis of class, ethnicity, and gender in the making of modern national states. Analyses of internationally mobile laborers historicize current transnational studies, problematize the historiography of national groups, and reveal how profoundly—and usually also how “nationally”—every multiethnic nation-state understood relations among ethnicity, race or color, class, and gender.
From East to West and West to East: Ties of Solidarity in the Pan-Pacific Revolutionary Trade Union Movement, 1923–1934
Authors: Fowler Josephine
Published: April 2008

In this article, I examine the contours of pan-Pacific revolutionary trade union internationalism from 1923 up through 1934, with special attention to the years 1928 to 1934, which years are commonly understood in Communist International (Comintern) historiography as the Third Period. The Third Period is typically viewed as being characterized by “a loss of influence” on the part of the Red International of Labor Unions (RILU or Profintern) as a result of the Comintern's “left” turn. My research shows that in spite of high levels of repression across Asia during the late 1920s and early 1930s and the continued existence of restrictive immigration and shipping laws in North America, the pan-Pacific revolutionary trade union movement retained a visible presence across the Pacific. Sustaining this movement were two groups of actors. First, were Chinese and Japanese seamen who, subject as they were to severe repression, understood that the strength of their unions at the local scale depended at least in part upon support from overseas and their ability to command space at the regional and international scales. Therefore, at great risk, through face to face contact and the medium of print, they sought to forge pan-Pacific ties of international solidarity. Second, were the Chinese and Japanese immigrant Communists who, also at great personal risk and with their efforts also always subject to repression and failure, sought to “jump” scales by boarding ships that came into North American ports and on which Chinese or Japanese seamen worked. Together these immigrant workers and seamen were the “conductors of the [pan-Pacific] revolutionary movement” linking up one side of the Pacific with the other.
Sustainable Alliances: The Origins of International Labor Environmentalism
Authors: Silverman Victor
Published: April 2008

This article examines evaluates the strength of the Labor-Environmentalist alliance of the late twentieth century. It traces the evolution of trade unionists' thinking about nature and the human relationship to the environment by examining intellectual and political sources of labor involvement in United Nations' environmental policy making from the 1950s through the 1980s. The article explores the reasons trade union organizations, notably the International Confederation of Free Trade Unions, the International Trade Secretariats (Global Union Federations) and the European Trade Union Confederation, participated in a variety of international conferences and institutions such as the 1972 Stockholm Conference on the Environment, the 1992 Rio Earth Summit and the 2002 Johannesburg World Summit on Sustainable Development. It finds that environmentally conscious trade unionists developed their own version of environmentalism and sustainable development based on a reworking of basic trade union principles, a reworking that emphasized solidarity with nature and made central the protection of the health and safety of workers, communities, and environments.
Interview with Allan Sekula
Authors: Tchen Jack (John Kuo Wei)
Published: April 2008

Still reeling from 9/11, I had been working in and about lower Manhattan nonstop until this trip. It was great to be far away in the smog-filtered Los Angeles sun, if even only for a day. I met Allan Sekula in his Echo Park work studio, a nondescript corner storefront filled with files of his photographs and boxes of exhibition prints just a stone's throw from Koreatown.
The Essential E.P. Thompson, edited by Dorothy Thompson. New Press: New York, 2001. x + 498 pp. $45.00 cloth; $21.95 paper.
Authors: Dworkin Dennis
Published: April 2008

Readers in the humanities and social sciences abound. There are those that introduce key texts in a given field. Others seek to encapsulate the contributions of a major intellectual figure. In this latter category, there are volumes that focus on cultural critics, social theorists, literary scholars, and political writers. But there are few—if any—that highlight the writings of historians. It is thus says a great deal regarding E.P. Thompson's stature that the New Press has published The Essential E.P. Thompson. He is, as the book's editor Dorothy Thompson states, “one of the most influential historians of his generation” (vii). But he is more than this, as readers of this journal undoubtedly know. He is among the major public intellectuals of the last half of the twentieth century, certainly in the English-speaking world.
The Essential E.P. Thompson, edited by Dorothy Thompson. New Press: New York, 2001. x + 498 pp. $45.00 cloth; $21.95 paper.
Authors: Yang Manuel
Published: April 2008

Putting together a reader from the polymorphously diverse writings of a formidably creative, dissident writer who reflects in his or her sensibility and voice the defining compass of the times that he or she has lived through and, moreover, helped remake is an unenviable task of tribute fraught with inevitable omissions and haunting incompletion. In his obituary on C. Wright Mills, his trans-Atlantic friend and comrade of the international New Left, Edward Thompson recognized that it was Mill's “style, rather than a comprehensive theory of social process . . . the style of a responsible and catholic eclectic” that he successfully attained in his late years and remains his enduring legacy. Thompson was able to make greater strides in achieving, if not a “comprehensive theory of social process,” a poetically incandescent, empirically textured way of reading this social process from the perspective of the English plebeians, artisans, and commoners, most famously with The Making of the English Working Class. Noting that in America The Making of the English Working Class “had both a Movement reading and an Academic reading,” Peter Linebaugh, a former student of Thompson's, has stressed its function as “an iconic text in some ways in the Movement . . . a text of particular class composition and a particular political moment” that also became among the students “a shield for the troops in this strategy, protecting us from the shafts and cuts of the Old Boy Network” of US higher education in the 1960s. Thirty-five years later, under the specter of another “particular class composition,” we may ask ourselves if The Essential E.P. Thompson can bid us to undertake new readings of the last “great bustard” and to pitch them against the neoliberal imperial Behemoth that encircles us today wherever we turn our eyes.
“Rough Mens” in “the Toughest Places I Ever Seen”: The Construction and Ramifications of Black Masculine Identity in the Mississippi Delta's Levee Camps, 1900–1935
Authors: McCoyer Michael
Published: April 2008

This article examines the “levee camp” as a social and cultural site for reconstituting rural black workers' masculine identities in the early twentieth-century Mississippi-Arkansas Delta. The construction of the Mississippi River's levees during this period depended heavily on the labor of black mule-drivers drawn from the Delta's cotton plantations. In spite of this dependency, the levee camps' exploitative commissaries and harsh disciplinary violence quashed workers' efforts to reclaim a sense of autonomy that was increasingly denied them on the region's plantations. However, partly in response to the perceived erosion of their authority within the sharecropper family, levee workers successfully used the notorious after-hours culture of the levee camps to construct a hyper-masculine image of themselves as “rough mens” who had been to the levee camps, enjoyed the sexual attention of camp women, and were manly enough to survive the murderous violence of white bosses and other “rough mens” alike. Using a series of 1930s labor investigations as well as early Delta blues hollers and songs about the levee camps, this article shows how black workers' efforts to cultivate this hyper-masculine levee worker image ultimately proved detrimental to their class interests. Levee contractors and foremen welcomed levee camp gambling, prostitution, drinking, and fighting as ways of reducing workers' wages and maintaining labor control in the camps. Ultimately, the levee camps provide a useful example of an all-male work site where gender had important, if unintended, ramifications for workers' class position.
Bodies, Sexuality and the “Modernization” of the British Working Classes, 1920s to 1960s
Authors: Brooke Stephen
Published: April 2008

A neglected aspect of the perceived “embourgeoisement” of the British working-classes in the 1950s was the representation of a blurring of class difference around questions of sexuality. In different ways, female bodies and sexuality in the postwar period became a means of talking about changing class identity and the modernization of society. In the 1920s and 1930s, the working-class body and working-class sexuality served as counterpoints to largely middle-class ideas of modern femininity and sexuality. Working-class women's inability to control their reproduction was portrayed as one cause of the deprivation experienced by the working classes. In the fifties, by contrast, working-class bodies and sexuality had become signifiers of the modernization of British class society. Working-class women were perceived as being able to control the size of their families. Such control was, with full employment and better housing, a mark of a modern, affluent working class. At the same time, working-class marriage was represented as increasingly incorporating notions of companionability and sexual pleasure previously only seen in middle-class life. “Embourgeoisement” in postwar Britain was thus represented as having a sexual aspect.
Spaces of Encounter: The Cultural Labor of Class Difference
Authors: Cameron Ardis
Published: April 2008

This article explores the complicated relationship between narratives of working-class America and formations of national Otherness. Arguing that class, sex, and ethnicity are deeply relational, it seeks to map the symbolic terrain and emotional depth of class difference as it circulates in the American imaginary. It ask how we might think about the cultural poetics of class difference in ways that make a difference—in ways that register class narratives as participants in constructions of the Nation and the “normal,” the irregular and the queer? Attending to the kinds of emotional and conceptual services stories of class perform, it locates “class” as part of a discursive imaginary topography that structures and turns narratives of working men and women into spaces of encounter, contest, and containment.
Production of ion beams in high-power laser–plasma
interactions and their applications
Authors: PEGORARO F. , ATZENI S. , BORGHESI M. , BULANOV S. , ESIRKEPOV T. , HONRUBIA J. , KATO Y. , KHOROSHKOV V. , NISHIHARA K. , TAJIMA T. , TEMPORAL M. , WILLI O.
Published: April 2008

Energetic ion beams are produced during the interaction of
ultrahigh-intensity, short laser pulses with plasmas. These
laser-produced ion beams have important applications ranging from the
fast ignition of thermonuclear targets to proton imaging, deep proton
lithography, medical physics, and injectors for conventional
accelerators. Although the basic physical mechanisms of ion beam
generation in the plasma produced by the laser pulse interaction with
the target are common to all these applications, each application
requires a specific optimization of the ion beam properties, that is,
an appropriate choice of the target design and of the laser pulse
intensity, shape, and duration.
Enhanced Raman scattering of a rippled laser beam in a magnetized
collisional plasma
Authors: SAINI NARESHPAL SINGH , GILL TARSEM SINGH
Published: April 2008

In the laser–plasma interaction experiments, self-focusing and
filamentation affect quite a large number of other parametric processes
including stimulated scattering processes. Nonlinearity considered in
the present problem is the collisional type. The coupling between the
main beam, ripple, and excited electron plasma wave is strong. Authors
have investigated the growing interaction of a rippled laser beam with
an electron plasma wave leading to enhanced Raman scattering. An
expression for scattered power is derived and the effect of the
externally applied magnetic field on the enhancement of scattered power
is observed. From computational results, it is observed that the effect
of increased intensity of the main beam leads to suppression of power
associated with the Raman scattered wave.
Ionization processes in the ultrashort, intense laser field interaction with large clusters
Authors: SHOKRI B. , NIKNAM A.R. , SMIRNOV M.
Published: April 2008

Multiple ionization of large clusters when they are irradiated by an intense ultrashort laser pulse is investigated. Different mechanisms, responsible for cluster ionization, are investigated. It is found that the ionization of large clusters, irradiated by a strong intense ultrashort laser pulse, is realized by means of the surface thermoemission.
Cold compression of solid matter by intense
heavy-ion-beam-generated pressure waves
Authors: CONSTANTIN C. , DEWALD E. , NIEMANN C. , HOFFMANN D.H.H , UDREA S. , VARENTSOV D. , JACOBY J. , FUNK U.N. , NEUNER U. , TAUSCHWITZ A.
Published: April 2008

Experimental investigations of heavy-ion-generated shock waves in
solid, multilayered targets were performed by applying a Schlieren and
a laser-deflection technique. Shock velocity and the corresponding
pressures, temporal and spatial density profiles inside the material
compressed by multiple shock waves, and details of the shock dynamics
were determined. Important for equation-of-state and phase transition
studies, such experiments extend their relevance to inertial
confinement fusion and astrophysical fundamental research.
Multigroup kinetic description of X-ray transport in hohlraums
Authors: BALDINA E.G.
Published: April 2008

The article presents the multigroup kinetic approximation of
radiation transport in hohlraum systems. The view factor-based method
of numerical solution is proposed. Its advantages are a detailed
account of the problem geometry and accurate handling of the solution
angular anisotropy and discontinuities. The method is computationally
efficient and easily parallelizable. Coupled to the kinetic + hydro
description of the wall dynamics, it represents a powerful tool for
integrated investigation of the systems with strongly inhomogeneous
optical properties.
Solutions of the nonlinear paraxial equation due to laser
plasma–interactions
Authors: OSMAN F. , BEECH R. , HORA H.
Published: April 2008

This article presents a numerical and theoretical study of the
generation and propagation of oscillation in the semiclassical limit
ħ → 0 of the nonlinear paraxial equation. In a general
setting of both dimension and nonlinearity, the essential differences
between the “defocusing” and “focusing” cases
are observed. Numerical comparisons of the oscillations are made
between the linear (“free”) and the cubic (defocusing and
focusing) cases in one dimension. The integrability of the
one-dimensional cubic nonlinear paraxial equation is exploited to give
a complete global characterization of the weak limits of the
oscillations in the defocusing case.
On formation of subnanosecond electron beams in air under
atmospheric pressure
Authors: TARASENKO V.F. , SKAKUN V.S. , KOSTYRYA I.D. , ALEKSEEV S.B. , ORLOVSKII V.M.
Published: April 2008

This article reports on experimental studies of subnanosecond
electron beams formed in air under atmospheric pressure. An electron
beam with an amplitude of ∼170 A with a duration at FWHM of
∼0.3 ns has been obtained. Based on beam temporal characteristics
and discharge spatial characteristics, the critical fields were
supposed to be reached at plasma approach to anode. Simultaneously, the
sharp high-energy pulse of e-beam current is generated. Of critical
importance is the cathode type and occurrence on the cathode of plasma
protrusions. It is shown that to get maximum amplitude of the electron
beam in the gas diode, the discharge in the gas diode should be
volumetric.
High resolution spectroscopy in the XUV with pairs of mutually coherent and time-delayed laser harmonics
Authors: BELLINI MARCO , CAVALIERI STEFANO , CORSI CHIARA , ERAMO ROBERTO , MATERAZZI MARZIA
Published: April 2008

We present a Ramsey technique using high-order harmonics for high-resolution atomic spectroscopy in the extreme ultraviolet. Pairs of time-delayed and phase-coherent harmonic pulses generated by the interaction of ultrashort and intense laser pulses with a noble gas are used to study excited states of krypton.
Tracking ground state Ba+ions in an expanding laser–plasma plume using time-resolved vacuum ultraviolet photoionization imaging
Authors: HIRSCH J.S. , KAVANAGH K.D. , KENNEDY E.T. , COSTELLO J.T. , NICOLOSI P. , POLETTO L.
Published: April 2008

We report results from a study of the integrated column density and expansion dynamics of ground-state-selected Ba+ions in a laser–plasma plume using a new experimental system—VPIF (vacuum-ultraviolet photoabsorption imaging facility). The ions are tracked by recording the attenuation of a pulsed and collimated vacuum ultraviolet beam, tuned to the 5p–6dinner-shell resonance of singly ionized barium, as the expanding plasma plume moves across it. The attenuated beam is allowed to fall on a CCD array where the spatial distribution of the absorption is recorded. Time-resolved ion velocity and integrated column density maps are readily extracted from the photoionization images.
X-ray spectral diagnostics for satellite lines of H-like Mg ions measured by a high resolution spectrometer
Authors: KATO TAKAKO , YAMAMOTO NORIMASA , ROSMEJ FRANK B.
Published: April 2008

X-ray spectra of H-like Mg ions produced in a laser plasma have been measured by space-resolved high-resolution spectroscopy. We identified satellite lines near Lyα lines, 2lnl′ − 1snl′ +hν forn= 2, 3, and 4. We construct a collisional radiative model including the doubly excited states for the intensity ratios of satellite lines. We use atomic data calculated by different methods for satellite lines and compare the results. We derive the electron temperature and density of the laser-produced plasma by a new technique using intensity ratios of only satellite lines. This technique is useful because the Lyα lines are often affected by opacity.
Simulation of high-intensity laser–plasma interactions by use of the 2D Lagrangian code “ATLANT-HE”
Authors: LEBO I.G. , DEMCHENKO N.N. , ISKAKOV A.B. , LIMPOUCH J. , ROZANOV V.B. , TISHKIN V.F.
Published: April 2008

Hot electrons may significantly influence interaction of ultrashort laser pulses with solids. Accurate consideration of resonant absorption of laser energy and hot electron generation at a critical surface was achieved through the developed physical and mathematical models. A two-dimensional (2D) ray-tracing algorithm has been developed to simulate laser beam refraction and Bremsstrahlung absorption with allowance for nonlinear influence of a strong electromagnetic field. Hot electron transport was considered as a straight-line flow weakening by a friction force calculated in the approximation of the average state of ionization. Developed models were coupled with the 2D Lagrangian gas dynamic code “ATLANT” that takes into account nonlinear heat transport. The developed program has been applied to simulate irradiation of Al foils by picosecond laser double pulses. Hot electron transport and heating resulted in thin foil explosions. The transition from the exploding foil regime to the ablative one with foil thickening has been simulated and analyzed at various values of laser light intensity. In second series of calculations we have modeled the interaction of a nanosecond iodine laser with a two-layered target.
Study of XUV beam splitter flatness for use on a Michelson interferometer
Authors: MORLENS ANNE-SOPHIE , ZEITOUN PHILIPPE , VANBOSTAL LAURENT , MERCERE PASCAL , FAIVRE GRÉGORY , HUBERT SÉBASTIEN , TROUSSEL PHILIPPE , REMOND CHRISTIAN , MARMORET RÉMY , DELMOTTE FRANCK , RAVET MARIE-FRANÇOISE , ROUILLAY MARC
Published: April 2008

A XUV Michelson interferometer has been developed by LIXAM/CEA/LCFIO and has been tested as a Fourier-transform spectrometer for measurement of X-ray laser line shape. The observed strong deformation of the interference fringes limited the interest of such an interferometer for plasma probing. Because the fringe deformation was coming from a distortion of the beam splitter (5 × 5 mm2open aperture, about 150 nm thick), several parameters of the multilayer deposition used for the beam splitter fabrication have been recently optimized. The flatness has been improved from 80 nm rms obtained by using the ion beam sputtering technique, to 20 nm rms by using the magnetron sputtering technique. Over 3 × 3 mm2, the beam splitter has a flatness better than 4 nm rms.
Easy spectrally tunable highly efficient X-ray backlighting schemes based on spherically bent crystals
Authors: PIKUZ T. , FAENOV A. , SKOBELEV I. , MAGUNOV A. , LABATE L. , GIZZI L.A. , GALIMBERTI M. , ZIGLER A. , BALDACCHINI G. , FLORA F. , BOLLANTI S. , DI LAZZARO P. , MURRA D. , TOMASSETTI G. , RITUCCI A. , REALE A. , REALE L. , FRANCUCCI M. , MARTELLUCI S. , PETROCELLI G.
Published: April 2008

New easy spectrally tunable backlighting schemes based on a spherically bent crystal are considered. Contrary to traditional backlighting scheme, in which the investigated objects should be placed between the backlighter and the crystal, for the considered schemes an object is placed downstream of the crystal, before the tangential or after the sagittal focus and an image of the object is recorded at the distance from the object corresponding to the needed magnification. The magnification is defined by the ratio of the distances from the sagittal focus to the detector and from the object to the sagittal focus. A ray-tracing modeling and experimental images of test meshes, obtained at incidence angles of the backlighter radiation of 10° and 22°, are presented. It is demonstrated that a simple linear transformation of the obtained astigmatic images allows reconstructing them as a stigmatic with an accuracy of 5–15%. For the spectral range around 9 Å a spatial resolution about 10 μm in a field of view of some square millimeters is achieved experimentally and confirmed by ray-tracing simulations.
Efficient hard X-ray source using femtosecond plasma at solid targets with a modified surface
Authors: GAVRILOV S.A. , GOLISHNIKOV D.M. , GORDIENKO V.M. , SAVEL'EV A.B. , VOLKOV R.V.
Published: April 2008

Recent results on constructing of an efficient hard X-ray source using solid targets irradiated by high-contrast 200-fs laser pulses with an intensity above 1016W/cm2are presented. We used different solid targets with a laser- and electrochemically modified surface layer: craters, pyramidal cavities, porous silicon, gratings. Experimental data obtained confirms that using solid targets with a corrugated surface one can achieve a prominent increase both in the efficiency of hard X-ray generation (in the quanta range 2–30 keV) and in the hot electron temperature of plasma.
Toward the single-cycle regime in the generation of high-order laser harmonics
Authors: PASCOLINI M. , POLETTO L. , SANSONE G. , STAGIRA S. , VOZZI C. , NISOLI M. , VILLORESI P. , TONDELLO G. , DE SILVESTRI S.
Published: April 2008

The dependence of the high-order harmonic cutoff spectrum from the absolute phase of the laser pulse is here experimentally investigated. Noticeable shifts are observed. Their interpretation is proposed with a model based on the absolute-phase dependence of the trajectories of the photoelectrons that contribute to a given harmonic order.
Soft laser-plasma X-ray source for differential absorption imaging
of tracing elements in thin samples
Authors: GIZZI L. A. , CECCHETTI C.A. , GALIMBERTI M. , GIULIETTI D. , GIULIETTI A. , KOESTER P. , LABATE L. , LAVILLE S. , TOMASSINI P.
Published: April 2008

The differential imaging technique is particularly suitable for the
detection of small concentrations of contrasts agents for biological
and medical applications in samples using X-ray radiography. In this
paper, we present an application of this technique using a laser-plasma
soft X-ray source combined with a bent crystal. Using a Fresnel plate
as a test object, we were able to obtain spatial resolutions of the
order of a few tens of microns. The use of our configuration to perform
differential imaging of a test-sample at the L2 edge of Br
at 1,596 eV is finally demonstrated.
Physics of Inertial Fusion: Beam Plasma Interaction,
Hydrodynamics, Hot Dense Matter, Stafano Atzeni and Jürgen
Meyer-ter-Vehn
Authors: Miley George H.
Published: April 2008

Physics of Inertial Fusion: Beam Plasma Interaction,
Hydrodynamics, Hot Dense Matter, Stafano Atzeni and Jürgen
Meyer-ter-Vehn, Clarendon Press, 2004, 458 pages, ISBN: 0198562640

This book has several remarkable highlights summarized on laser
produced plasmas and particle beam driven fusion energy. In contrast to
the usual books, the nuclear fusion reactions are presented with very
detailed experience, including pycnonuclear reactions, spin polarization,
and mentioning the 25 orders of magnitude less probable weak force
pp-reaction than DT. There is a rather comprehensive collection of the
conditions of confinement, spherical implosion, ignition burn, and gain.
Hydrodynamics is based on a one fluid model, not Schlüter's
space charge quasi-neutral two-fluid model nor the genuine two-fluid
treatment. Hohlraum targets are covered and the fast ignition (FI)
contains the forte of the authors' own achievements though the entire
problems shown experimentally or theoretically (Mulser
et al., 2004) are not discussed nor the new aspects on FI
known before finishing the book (Hora, 2004).
The 36 pages for the entire physics of (laser- and particle-) beam-target
interaction are used to sketch at least the most important aspects.
A 3D trajectory numerical simulation of the transport of energetic light ion beams in plasma targets
Authors: BARRIGA-CARRASCO MANUEL D. , MAYNARD GILLES
Published: April 2008

We present in this paper a theoretical modeling and a numerical simulation devoted to the problem of transport and energy deposition profile of high current light ion beams interacting with dense matter. A numerical code, named MBC-ITFIP, is used to follow the trajectories of light atomic or molecular ions inside plasma targets with non-uniform density, temperature and composition profiles. MBC-ITFIP has been more specifically optimized for application of ion beams generated by the new high intensity laser sources, such as radiography and isochoric heating of dense plasmas.
Generation of quasi-monoenergetic electron beams using ultrashort and ultraintense laser pulses
Authors: GLINEC Y. , FAURE J. , PUKHOV A. , KISELEV S. , GORDIENKO S. , MERCIER B. , MALKA V.
Published: April 2008

Plasma-based accelerators have been proposed for the next generation of compact accelerators because of the huge electric fields they can support. However, it has been difficult to use them efficiently for applications because they produce poor quality particle beams with large energy spreads. Here, we demonstrate a dramatic enhancement in the quality of electron beams produced in laser-plasma interaction: an ultrashort laser pulse drives a plasma bubble which traps and accelerates plasma electrons to a single energy. This produces an extremely collimated and quasi-monoenergetic electron beam with a high charge of 0.5 nanocoulomb at energy 170 ± 20 MeV.
Thermonuclear gain and parameters of fast ignition ICF-targets
Authors: GUS'KOV S. YU.
Published: April 2008

The requirements of matching shell ICF target parameters, parameters
of compressing, and triggering drivers under direct (fast) ignition are
developed. Thin shell target, which represents a shell-ablator with a
DT-ice layer, frosted on the inner surface of the shell are considered.
Design of a target which ensures the energy supply from the triggering
driver to the central part of thermonuclear fuel, in both spherical and
cylindrical geometry is developed. Spherical target is furnished with one
or two conical channels for the injection of the triggering driver
radiation. The ends of the cylindrical target are protected by heavy
material walls that have the holes of the radius equal to the final radius
of compressed fuel. It was found that the parameters of fast ignition
spherical and cylindrical targets, which provide high thermonuclear gain
of 500–2000 in the range of the compressing driver energy of
1–10 MJ, may be matched with the drivers parameters at low aspect
ratios of the targets, 10–20. The operation of spherical targets at
the moderate radius convergence ratio of 15–20, may be provided at
the triggering driver energy not higher than 30 kJ. The operation of
cylindrical target with spin-oriented DT-fuel at radius convergence ratio
of 20–25 may be provided at 150–200 kJ of the triggering
driver energy.
Advanced 20 TW Ti:S laser system for X-ray laser and coherent XUV generation irradiated by ultra-high intensities
Authors: KURODA HIROTO , SUZUKI MASAYUKI , GANEEV RASHID , ZHANG JUN , BABA MOTOYOSHI , OZAKI TSUNEYUKI , WEI ZHI YI , ZHANG JIE
Published: April 2008

In order to develop a high repetition rate X-ray lasers, the longitudinal-pumped transient collisional excitation (TCE) X-ray laser is one of the most effective pumping schemes. The high directive Ni-like Mo 18.9 nm soft X-ray laser pumped by modest laser energy has already been demonstrated by using the tabletop size Ti:sapphire/Nd:glass laser system that delivering energy of 150 mJ in 475 fs at the center wavelength of 1054 nm. The total energy in the pre-pulse and the main pulse was 150 mJ, which will make possible multi-hertz operation. To pursue the high repetition rate of the laser-driven TCE X-ray laser, we have designed a new 20 TW Ti:Sapphire laser system (600 mJ, 30 fs, 10 Hz). Special attention was paid to improve the contrast ratio, control of pulse shape as well as phase by an acoustic optic programmable dispersive filter (AOPDF) and 1 kHz preamplifier. Preliminary data have shown good laser characteristics. As the preliminary experiments, we have investigated high order harmonics generation from low-density laser plasma by using the solid target irradiated by a femtosecond laser pulse. The highest order was the 51st. harmonic at wavelength of 15.61 nm.
Direct drive double shell target implosion hydrodynamics on
OMEGA
Authors: KYRALA GEORGE A. , DELAMATER NORMAN , WILSON DOUGLAS , GUZIK JOYCE , HAYNES DON , GUNDERSON MARK , KLARE KENNETH , WATT ROBERT W. , WOOD WILLIAM M. , VARNUM WILLIAM
Published: April 2008

Imploding indirect-drive double shell targets may provide an
alternative, non-cryogenic path to ignition at the National Ignition
Facility (NIF). Experiments are being pursued at OMEGA to understand the
hydrodynamics of these implosions and the possibility of scaling it to the
NIF design. We have used 40 beams from the OMEGA laser to directly drive
the capsules, and we have used the remaining 20 beams to backlight the
imploding shells from two different directions at multiple times. We will
review the recent experiments to measure the hydrodynamics of the targets
using two-view X-ray radiography of the capsules. We will present data on
measured yields from the targets. We will present a measured time history
of the hydrodynamics of the implosion. Experiments were pursued using
direct drive in which the M-band effect (experienced in the indirect drive
experiments) could be eliminated or controlled. It was learned in the
direct drive experiments that the best performing capsules were those that
had a thin outer layer of gold. This effectively causes M-band pre-heat
effects giving implosion hydrodynamics and performance closer to the
indirect drive case. We will review the methods used to radiograph the
targets and the techniques used to extract useful information to compare
with calculations. The effect of imperfections in the target construction
will be shown to be minimal during the initial stage of implosion. The
yields from the targets were observed to be uniformly low compared to
indirect-drive.
Laser-induced migration and isotope separation of epi-thermal monomers and dimers in supercooled free jets
Authors: EERKENS JEFF W.
Published: April 2008

Explicit relations are developed to estimate the outflux of migrating isotopomersiQF6to the outskirts of a supersonic supercooled free jet whose core is irradiated by a co-axial laser beam and intercepted by a skimmer that separates core gas from peripheral gases. The QF6target gas is diluted in carrier gas G (G = He, N2, Ar, Xe, SF6, etc.) which determines the jet's supersonic characteristics and forms QF6:G dimers at low temperatures. Under isotope-selective laser excitation, excitediQF6* convert their vibrational energy V into kinetic energy T after forming transientiQF6*:G dimers that dissociate in sub-microseconds. Three migrating groups with different transport parameters are created in the jet: thermal monomers, faster-moving epithermal monomers, and slower-moving dimers. Jet-core-fleeing QF6is enriched iniQF6due to enhanced outwards migration ofiQF6!epithermals and reduced escape ofjQF6:G dimers in the jet. Isotope enrichments in the rim gases are highest for heavier carrier gases such as G = Xe or G = SF6.
An inductive scheme of power conditioning at mega-Ampere
currents
Authors: CHUVATIN A.S. , KOKSHENEV V.A. , ARANCHUK L.E. , HUET D. , KURMAEV N.E. , FURSOV F.I.
Published: April 2008

This work describes an inductive energy storage scheme intended for
power multiplication at mega-Ampere currents. The key power multiplication
element of the scheme is an opening switch generating the voltage of
inductive origin. The switch represents an additional volume with
magnetically accelerated solid-state or plasma conductor between the
generator and the load. Motion of the conductor increases the inductance
of the volume. A sufficiently fast increase of this inductance at the end
of magnetic energy storage time ensures power multiplication. A critical
requirement for the accelerated conductor is the possibility of temporal
profiling of the inductance increase. A proof-of-principle experiment at
GIT12 shows that such profiling is possible. We suggest a simple analysis
of the scheme efficiency and illustrate this analysis for a
multi-mega-Ampere class generator. The scheme is alternative to existing
inductive energy storage technologies for pulsed-power conditioning at
high currents.
Laser-Compton scattering as a tool for electron beam
diagnostics
Authors: CHOUFFANI K. , HARMON F. , WELLS D. , JONES J. , LANCASTER G.
Published: April 2008

Laser-Compton scattering (LCS) experiments were carried out at the
Idaho Accelerator Center (ICA) using the 5 ns (FWHM) and 22 MeV electron
beam. The electron beam was brought to an approximate head-on collision
with a 7 ns (FWHM), 10 Hz, 29 MW peak power Nd:YAG laser. We observed
clear and narrow X-ray peaks resulting from the interaction of
relativistic electrons with the 532 nm Nd:YAG laser second harmonic line
on top of a very low bremsstrahlung background. We have developed a method
of using LCS as a non-intercepting electron beam monitor. Unlike the
method used by Leemans et al. (1996),
our method focused on the variation of the shape of the LCS spectrum
rather than the LCS intensity as a function of the observation angle in
order to extract the electron beam parameters at the interaction region.
The electron beam parameters were determined by making simultaneous fits
to spectra taken across the LCS X-ray cone. We also used the variation of
LCS X-ray peak energy and spectral width as a function of the detector
angles to determine the electron beam angular spread, and direction and
compared the results to the previous method. Experimental data show that
in addition to being viewed as potential bright, tunable and monochromatic
X-ray source, LCS can provide important information on electron beam pulse
length, direction, energy, angular, and energy spread. Since the quality
of LCS X-ray peaks, such as degree of monochromaticity, peak energy and
flux, depends strongly on the electron beam parameters, LCS can therefore
be viewed as an important non-destructive means for electron beam
diagnostics.
Low velocity ion stopping of relevance to the US beam-target
program
Authors: DEUTSCH CLAUDE , POPOFF ROMAIN
Published: April 2008

We have focused our attention on the stopping mechanisms involved in
the recently proposed ion beam-target US program. This mechanism
emphasizes out production of warm dense matter through pulsed ion beams,
linearly accelerated, and interacting with thin foils in Bragg peak
conditions. We reviewed the relevant energy loss mechanisms involved at
moderate and low velocity ion projectile. Small velocities close to zero
are given some attention.
Numerical simulations of Rayleigh-Taylor instability in elastic solids
Authors: CELA J.J. LÓPEZ , PIRIZ A.R. , MORENO M.C. SERNA , TAHIR N.A.
Published: April 2008

Numerical simulations of the Rayleigh-Taylor instability in the interface of two semi-infinite media have been performed based on the finite element method. Two different interfaces have been considered: elastic solid/elastic solid and elastic solid/viscous fluid. The results have been compared with previously published analytical models. In particular, the asymptotic growth rate has been compared with the model by Terrones (2005) while the initial transient phase is compared with the model by Pirizet al.(2005). Finally, some examples show the importance of such an initial transient phase if more realistic material laws (for example, elastoplastic behavior) are taken into account.
Self-focusing and self-phase modulation of an elliptic Gaussian
laser beam in collisionless magnetoplasma
Authors: SAINI NARESHPAL SINGH , GILL TARSEM SINGH
Published: April 2008

The problem of nonlinear self-focusing of elliptic Gaussian laser beam
in collisionless magnetized plasma is studied using variation approach.
The dynamics of the combined effects of nonlinearity and spatial
diffraction is presented. With a and b as the beam width
parameters of the beam along x and y directions, respectively, the
phenomenon of cross-focusing is observed where focusing of a
results in defocusing of b and vice versa. Although no stationary
self-trapping is observed, oscillatory self-trapping occurs far below the
threshold. The regularized phase is always negative.
Sculpted pulsed indium atomic beams via selective laser ablation of
thin film
Authors: ALTI KAMLESH , KHARE ALIKA
Published: April 2008

We present a novel experiment for the generation of sculpted pulsed
indium atomic beams of regular arrays in one and two-dimensions via rear
side ablation of indium by two and four beams interference pattern using
second harmonic of high power Nd: YAG laser under high vacuum
(10−5 Torr).
General foundation for the nonlinear ponderomotive four-force in laser-plasma interactions
Authors: ROWLANDS T.P.
Published: April 2008

The interaction of electromagnetic radiation with plasmas is studied in relativistic four-vector formalism. A gauge and Lorentz invariant ponderomotive four-force is derived from the time dependent nonlinear three-force of Hora (1985). This four-force, due to its Lorentz invariance, contains new magnetic field terms. A new gauge and Lorentz invariant model of the response of plasma to electromagnetic radiation is then devised. An expression for the dispersion relation is obtained from this model. It is then proved that the magnetic permeability of plasma is unity for a general reference frame. This is an important result since it has been previously assumed in many plasma models.
Long term stabilization of the beam combination laser with a phase
controlled stimulated Brillouin scattering phase conjugation mirrors for
the laser fusion driver
Authors: KONG HONG JIN , YOON JIN WOO , SHIN JAE SUNG , BEAK DU HYUN , LEE BONG JU
Published: April 2008

Laser fusion requires very high energy/power output with high
repetition rate over 10 Hz, which is very difficult with the current laser
technologies. However, the recent research work on the phase controlling
of the stimulated Brillouin scattering wave enables the realization of
this kind of laser fusion driver. The recent progress of controlling the
phase has been successfully demonstrated by the self-generated density
modulation method proposed by one of the authors (Kong). Nevertheless, it
showed a long-term fluctuation of the phase because of the long-term
fluctuation of the density of the SBS medium due to the thermal
fluctuation. This long-term thermal fluctuation is inevitable a fact in
nature. The authors used a specially designed stabilizing system for the
phase controlling system, which has the PZT control of the mirror for
phase controlling SBS-PCM (the so-called feedback mirror). This system
stabilizes the phase controlling system very well for more than 1 h. This
technique will help the laser fusion driver to be realized sooner than
expected. In addition, we propose a similar scheme to be applied to the
ultra-fast pulse laser system, which must operate at high repetition rate
for the laser fusion energy power plant.
Design, development, and testing of non-intercepting profile
diagnostics for intense heavy ion beams using a capacitive pickup and beam
induced gas fluorescence monitors
Authors: BECKER F. , HUG A. , FORCK P. , KULISH M. , NI P. , UDREA S. , VARENTSOV D.
Published: April 2008

An intense and focused heavy ion beam is a suitable tool to generate
high energy density in matter. To compare results with simulations it is
essential to know beam parameters as intensity, longitudinal, and
transversal profile at the focal plane. Since the beam's energy
deposition will melt and evaporate even tungsten, non-intercepting
diagnostics are required. Therefore a capacitive pickup with high
resolution in both time and space was designed, built and tested at the
high temperature experimental area at GSI. Additionally a beam induced
fluorescence monitor was investigated for the synchrotron's (SIS-18)
energy-regime (60–750 AMeV) and successfully tested in a
beam-transfer-line.