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1

Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider Relativistic Heavy Ion Collider managed for the U.S. Department of Energy by Brookhaven Science Associates, founded by Stony Brook University and Battelle. managed for the U.S. Department of Energy by Brookhaven Science Associates, a company founded by Stony Brook University and Battelle 07/07 Brookhaven National Laboratory Funded by the U.S. Department of Energy, Brookhaven National Laboratory is a multipurpose research institution located on a 5,300-acre site on Long Island, New York. Six Nobel Prize-winning discoveries have been made at Brookhaven Lab. The Laboratory operates large-scale scientific facilities and performs research in physics, chemistry, biology, medicine, applied science, and

2

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

indicate that collisions of small particles with large gold nuclei at the Relativistic Heavy Ion Collider may be serving up miniscule servings of hot quark-gluon plasma. RHIC...

3

Relativistic Heavy Ion Collider, RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

The Relativistic Heavy Ion Collider website has moved to www.bnl.govrhicdefault.asp Sponsored by the U.S. Department of Energy Office of Science, Office of Nuclear Physics. Last...

4

Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

at the same time. Capable of accelerating 70 trillion protons with every pulse, and heavy ions such as gold and iron, the AGS receives protons and other ions from the AGS...

5

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider Relativistic Heavy Ion Collider Photo of LINAC The Relativistic Heavy Ion Collider (RHIC) is a world-class particle accelerator at Brookhaven National Laboratory where physicists are exploring the most fundamental forces and properties of matter and the early universe. RHIC accelerates beams of particles (e.g., the nuclei of heavy atoms such as gold) to nearly the speed of light, and smashes them together to recreate a state of matter thought to have existed immediately after the Big Bang some 13.8 billion years ago. STAR and PHENIX, two large detectors located around the 2.4-mile-circumference accelerator, take "snapshots" of these collisions to reveal a glimpse of the basic constituents of visible matter, quarks and gluons. Understanding matter at

6

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites

Brookhaven National Laboratory Brookhaven National Laboratory search U.S. Department of Energy logo Home RHIC Science News Images Videos For Scientists Björn Schenke 490th Brookhaven Lecture, 12/18 Join Björn Schenke of Brookhaven Lab's Physics Department for the 490th Brookhaven Lecture, titled 'The Shape and Flow of Heavy Ion Collisions,' on Wednesday, Dec. 18, at 4 p.m. in Berkner Hall. droplets Tiny Drops of Hot Quark Soup-How Small Can They Be? New analyses indicate that collisions of small particles with large gold nuclei at the Relativistic Heavy Ion Collider may be serving up miniscule servings of hot quark-gluon plasma. RHIC Physics RHIC is the first machine in the world capable of colliding ions as heavy as gold. The Spin Puzzle RHIC is the world's only machine capable of colliding beams of polarized

7

RHIC | Physics of the Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

The Physics of RHIC Physicists from around the world are using the Relativistic Heavy Ion Collider to explore some of Nature's most basic -- and intriguing -- ingredients and...

8

Brookhaven National Laboratory The Relativistic Heavy Ion Collider (RHIC)  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider (RHIC) Relativistic Heavy Ion Collider (RHIC) An Exciting Beginning and a Compelling Future At the Relativistic Heavy Ion Collider (RHIC), a world-class particle accelerator at Brookhaven National Laboratory, physicists are exploring the most fundamental forces and properties of matter and the early universe, with important implications for our understanding of the world around us. Operated with funding from the U.S. Department of Energy's Office of Science, the Relativistic Heavy Ion Collider (RHIC), was designed to recreate a state of matter thought to have existed immediately after the Big Bang some 13 billion years ago, and to investigate how the proton gets its spin and intrinsic magnetism from its quark and gluon constituents. Large detectors located

9

Relativistic hydrodynamics, heavy ion reactions and antiproton annihilation  

SciTech Connect

The application of relativistic hydrodynamics to relativistic heavy ions and antiproton annihilation is summarized. Conditions for validity of hydrodynamics are presented. Theoretical results for inclusive particle spectra, pion production and flow analysis are given for medium energy heavy ions. The two-fluid model is introduced and results presented for reactions from 800 MeV per nucleon to 15 GeV on 15 GeV per nucleon. Temperatures and densities attained in antiproton annihilation are given. Finally, signals which might indicate the presence of a quark-gluon plasma are briefly surveyed.

Strottman, D.

1985-01-01T23:59:59.000Z

10

Single event upset testing with relativistic heavy ions  

SciTech Connect

Two bipolar devices, the AMD 2901B microprocessor and the AMD 27LS00 256-bit RAM, have been tested for single event upset using relativistic heavy ions. Upset thresholds and asymptotic cross sections have been measured with iron, argon and neon beams having cosmic ray energies. Further, the magnitude of the funnel effect in the 2901B was determined by irradiating the device at normal incidence and at large angles and comparing the observed upset thresholds. Combinatorial logic upsets were seen in the 2901B and their cross section measured. The 27LS00 exhibited multibit upset produced by single ions penetrating the device edge-on.

Criswell, T.L.; Measeal, P.R.; Walin, K.L.

1984-12-01T23:59:59.000Z

11

AdS/CFT Correspondence and Hydrodynamics of Relativistic Heavy Ion Collisions.  

E-Print Network (OSTI)

??The experiments performed at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab have discovered a state of matter called the strongly coupled quark-gluon (more)

Alsup, James Ethan

2010-01-01T23:59:59.000Z

12

Particle-production mechanism in relativistic heavy-ion collisions  

SciTech Connect

We discuss the production of particles in relativistic heavy-ion collisions through the mechanism of massive bremsstrahlung, in which massive mesons are emitted during rapid nucleon acceleration. This mechanism is described within the framework of classical hadrodynamics for extended nucleons, corresponding to nucleons of finite size interacting with massive meson fields. This new theory provides a natural covariant microscopic approach to relativistic heavy-ion collisions that includes automatically spacetime nonlocality and retardation, nonequilibrium phenomena, interactions among all nucleons, and particle production. Inclusion of the finite nucleon size cures the difficulties with preacceleration and runaway solutions that have plagued the classical theory of self-interacting point particles. For the soft reactions that dominate nucleon-nucleon collisions, a significant fraction of the incident center-of-mass energy is radiated through massive bremsstrahlung. In the present version of the theory, this radiated energy is in the form of neutral scalar ({sigma}) and neutral vector ({omega}) mesons, which subsequently decay primarily into pions with some photons also. Additional meson fields that are known to be important from nucleon-nucleon scattering experiments should be incorporated in the future, in which case the radiated energy would also contain isovector pseudoscalar ({pi}{sup +}, {pi}{sup {minus}}, {pi}{sup 0}), isovector scalar ({delta}{sup +}, {delta}{sup {minus}}, {delta}{sup 0}), isovector vector ({rho}{sup +}, {rho}{sup {minus}}, {rho}{sup 0}), and neutral pseudoscalar ({eta}) mesons.

Bush, B.W.; Nix, J.R.

1994-07-01T23:59:59.000Z

13

Spacetime nonlocality and retardation in relativistic heavy-ion collisions  

SciTech Connect

We discuss the exact numerical solution of the classical relativistic equations of motion for a Lagrangian corresponding to point nucleons interacting with massive scalar and vector meson fields. The equations of motion contain both external retarded Lorentz forces and radiation-reaction forces; the latter involve nonlocal terms that depend upon the past history of the nucleon in addition to terms analogous to those of classical electrodynamics. The resulting microscopic many-body approach to relativistic heavy-ion collisions is manifestly Lorentz covariant and allows for nonequilibrium phenomena, interactions with correlated clusters of nucleons, and particle production. For point nucleons, the asymptotic behavior of nucleonic motion prior to the collision is exponential, with a range in proper time of approximately 0.5 fm. However, this behavior is altered by the finite nucleon size, whose effect we are currently incorporating into our equations of motion. The spacetime nonlocality and retardation that will be present in the solutions of these equations may be responsible for significant collective effects in relativstic heavy-ion collisions. 11 refs., 3 figs.

Bush, B.W.; Nix, J.R.; Sierk, A.J.

1991-01-01T23:59:59.000Z

14

Relativistic Heavy Ion Collider (RHIC) Animation and Multimedia Collection  

DOE Data Explorer (OSTI)

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is a world-class scientific research facility that began operation in 2000, following 10 years of development and onstruction. Hundreds of physicists from around the world use RHIC to study what the universe may have looked like in the first few moments after its creation. RHIC drives two intersecting beams of gold ions head-on, in a subatomic collision. This library of animations and multimedia includes virtual video tours of the RHIC complex, of the spin configuration, and of experiments; documentaries of the science involved; animations of the various kinds of collisions and reactions; event displays; and even interactive Java games about RHIC and RHIC physics.

15

Relativistic Heavy Ion Collider | The Case for Continuing Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

The Case for Continuing RHIC Operations The Case for Continuing RHIC Operations The Relativistic Heavy Ion Collider (RHIC) - the nation's only remaining particle collider, located at Brookhaven National Laboratory - has made a series of landmark discoveries and continuing breakthroughs in science and technology. One major accomplishment has been RHIC's ability to recreate and study in detail a type of matter that last existed at the beginning of the universe to better understand the strongest force in nature - the force that holds together the fundamental particles that make up 99 percent of visible matter in the universe today, everything from stars to planets to people. In addition to giving us a new way to explore and understand the nature of the early universe and the force that holds together ordinary matter, research at RHIC has revealed stunning

16

Observation of snake resonances at Relativistic Heavy Ion Collider  

SciTech Connect

The Siberian snakes are powerful tools in preserving polarization in high energy accelerators has been demonstrated at the Brookhaven Relativistic Heavy Ion Collider (RHIC). Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the Siberian snakes also introduce a new set of depolarization resonances, i.e. snake resonances as first discovered by Lee and Tepikian. The intrinsic spin resonances above 100 GeV are about a factor of two stronger than those below 100 GeV which raises the challenge to preserve the polarization up to 250 GeV. In 2009, polarized protons collided for the first time at the RHIC design store energy of 250 GeV. This paper presents the experimental measurements of snake resonances at RHIC. The plan for avoiding these resonances is also presented.

Bai, M.; Ahrens, L.; Alekseev, I.G.; Alessi, J.; et al

2010-09-27T23:59:59.000Z

17

Consequences of energy conservation in relativistic heavy-ion collisions  

E-Print Network (OSTI)

Complete characterization of particle production and emission in relativistic heavy-ion collisions is in general not feasible experimentally. This work demonstrates, however, that the availability of essentially complete pseudorapidity distributions for charged particles allows for a reliable estimate of the average transverse momenta and energy of emitted particles by requiring energy conservation in the process. The results of such an analysis for Au+Au collisions at sqrt{s_{NN}}= 130 and 200 GeV are compared with measurements of mean-p_T and mean-E_T in regions where such measurements are available. The mean-p_T dependence on pseudorapidity for Au+Au collisions at 130 and 200 GeV is given for different collision centralities.

B. B. Back

2005-08-15T23:59:59.000Z

18

Langevin dynamics of heavy flavors in relativistic heavy-ion collisions  

E-Print Network (OSTI)

We study the stochastic dynamics of c and b quarks, produced in hard initial processes, in the hot medium created after the collision of two relativistic heavy ions. This is done through the numerical solution of the relativistic Langevin equation. The latter requires the knowledge of the friction and diffusion coefficients, whose microscopic evaluation is performed treating separately the contribution of soft and hard collisions. The evolution of the background medium is described by ideal/viscous hydrodynamics. Below the critical temperature the heavy quarks are converted into hadrons, whose semileptonic decays provide single-electron spectra to be compared with the current experimental data measured at RHIC. We focus on the nuclear modification factor R_AA and on the elliptic-flow coefficient v_2, getting, for sufficiently large p_T, a reasonable agreement.

W. M. Alberico; A. Beraudo; A. De Pace; A. Molinari; M. Monteno; M. Nardi; F. Prino

2010-09-13T23:59:59.000Z

19

Langevin dynamics of heavy flavors in relativistic heavy-ion collisions  

E-Print Network (OSTI)

We study the stochastic dynamics of c and b quarks, produced in hard initial processes, in the hot medium created after the collision of two relativistic heavy ions. This is done through the numerical solution of the relativistic Langevin equation. The latter requires the knowledge of the friction and diffusion coefficients, whose microscopic evaluation is performed treating separately the contribution of soft and hard collisions. The evolution of the background medium is described by ideal/viscous hydrodynamics. Below the critical temperature the heavy quarks are converted into hadrons, whose semileptonic decays provide single-electron spectra to be compared with the current experimental data measured at RHIC. We focus on the nuclear modification factor R_AA and on the elliptic-flow coefficient v_2, getting, for sufficiently large p_T, a reasonable agreement.

Alberico, W M; De Pace, A; Molinari, A; Monteno, M; Nardi, M; Prino, F

2011-01-01T23:59:59.000Z

20

T.D. LEE: RELATIVISTIC HEAVY ION COLLISIONS AND THE RIKEN BROOKHAVEN CENTER.  

SciTech Connect

This paper presents the history of Professor T. D. Lee's seminal work on the theory of relativistic heavy ion collisions, and the founding and development of the Riken Brookhaven Center. A number of anecdotes are given about Prof. Lee, and his strong positive effect on his colleagues, particularly young physicists.

MCLERRAN,L.; SAMIOS, N.

2006-11-24T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Multi Module Modeling of Ultra-Relativistic Heavy Ion Collisions.  

SciTech Connect

Multi Module Model is required for the realistic and detailed description of an ultrarelativistic heavy ion reaction. We are working in the framework of such a model: initial stages are described by Effective String Rope Model with expanding final streaks; hydrodynamical approach is used for the intermediate stages. This paper is mainly devoted to Third Module - the one dealing with Freeze Out (FO). Two possibilities are discussed in details: (A) freeze out at the constant time hypersurface, where the statistical production model is used to describe post FO particle species; and (B) simultaneous hadronization and freeze out from supercooled QGP. For the last case the ALCOR-like algorithm for calculation of the post FO particle species is presented, due to the fact that these do not have time to reach chemical equilibrium.

Magas, V. K.; Csernai, L. P. (Lszl P.); Keranen, A.; Manninen, J.; Strottman, D. D. (Daniel D.)

2002-01-01T23:59:59.000Z

22

Bound-Free Electron-Positron Pair Production in Relativistic Heavy-Ion Collisions  

E-Print Network (OSTI)

The bound-free electron-positron pair production is considered for relativistic heavy ion collisions. In particular, cross sections are calculated for the pair production with the simultaneous capture of the electron into the 1s ground state of one of the ions and for energies that are relevant for the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Colliders (LHC). In the framework of perturbation theory, we applied Monte-Carlo integration techniques to compute the lowest-order Feynman diagrams amplitudes by using Darwin wave functions for the bound states of the elec- trons and Sommerfeld-Maue wave functions for the continuum states of the positrons. Calculations were performed especially for the collision of Au + Au at 100 GeV/nucleon and Pb + Pb at 3400 GeV/nucleon.

M. Y. Sengul; M. C. Guclu; S. Fritzsche

2009-07-30T23:59:59.000Z

23

Hydro-kinetic approach to relativistic heavy ion collisions  

E-Print Network (OSTI)

We develop a combined hydro-kinetic approach which incorporates a hydrodynamical expansion of the systems formed in \\textit{A}+\\textit{A} collisions and their dynamical decoupling described by escape probabilities. The method corresponds to a generalized relaxation time ($\\tau_{\\text{rel}}$) approximation for the Boltzmann equation applied to inhomogeneous expanding systems; at small $\\tau_{\\text{rel}}$ it also allows one to catch the viscous effects in hadronic component - hadron-resonance gas. We demonstrate how the approximation of sudden freeze-out can be obtained within this dynamical picture of continuous emission and find that hypersurfaces, corresponding to a sharp freeze-out limit, are momentum dependent. The pion $m_{T}$ spectra are computed in the developed hydro-kinetic model, and compared with those obtained from ideal hydrodynamics with the Cooper-Frye isothermal prescription. Our results indicate that there does not exist a universal freeze-out temperature for pions with different momenta, and support an earlier decoupling of higher $p_{T}$ particles. By performing numerical simulations for various initial conditions and equations of state we identify several characteristic features of the bulk QCD matter evolution preferred in view of the current analysis of heavy ion collisions at RHIC energies.

S. V. Akkelin; Y. Hama; Iu. A. Karpenko; Yu. M. Sinyukov

2008-04-25T23:59:59.000Z

24

Hydro-inspired parameterizations of freeze-out in relativistic heavy-ion collisions  

E-Print Network (OSTI)

Popular parameterizations of the freeze-out conditions in relativistic heavy-ion collisions are discussed. Similarities and differences between the blast-wave model and the single-freeze-out model, both used recently to interpret the RHIC data, are outlined. A non-boost-invariant extension of the single-freeze-out model is proposed and applied to describe the recent BRAHMS data.

Wojciech Florkowski; Wojciech Broniowski

2004-10-19T23:59:59.000Z

25

Final Report for Project ``Theory of ultra-relativistic heavy-ion collisions''  

SciTech Connect

In the course of this project the Ohio State University group led by the PI, Professor Ulrich Heinz, developed a comprehensive theoretical picture of the dynamical evolution of ultra-relativistic heavy-ion collisions and of the numerous experimental observables that can be used to diagnose the evolving and short-lived hot and dense fireball created in such collisions. Starting from a qualitative understanding of the main features based on earlier research during the last decade of the twentieth century on collisions at lower energies, the group exploited newly developed theoretical tools and the stream of new high-quality data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory (which started operations in the summer of the year 2000) to arrive at an increasingly quantitative description of the experimentally observed phenomena. Work done at Ohio State University (OSU) was instrumental in the discovery during the years 2001-2003 that quark-gluon plasma (QGP) created in nuclear collisions at RHIC behaves like an almost perfect liquid with minimal viscosity. The tool of relativistic fluid dynamics for viscous liquids developed at OSU in the years 2005-2007 opened the possibility to quantitatively determine the value of the QGP viscosity empirically from experimental measurements of the collective flow patterns established in the collisions. A first quantitative extraction of the QGP shear viscosity, with controlled theoretical uncertainty estimates, was achieved during the last year of this project in 2010. OSU has paved the way for a transition of the field of relativistic heavy-ion physics from a qualitative discovery stage to a new stage of quantitative precision in the description of quark-gluon plasma properties. To gain confidence in the precision of our theoretical understanding of quark-gluon plasma dynamics, one must test it on a large set of experimentally measured observables. This achievement report demonstrates that we have, at different times, systematically investigated both so-called ``soft" and ``hard, penetrating" probes of the fireball medium: hadron yields and momentum spectra and their anisotropies, two-particle momentum correlations, high-energy partons fragmenting into jets, heavy quarks and heavy-flavor mesons, and electromagnetic probes (photons and dileptons). Our strongest emphasis, and our most significant achievements, has, however, always remained on understanding the bulk behavior of the heavy-ion fireball medium, for which soft probes provide the most abundantly available data and thus the most stringent constraints.

Ulrich W. Heinz

2012-11-09T23:59:59.000Z

26

Charm elliptic flow in relativistic heavy-ion collisions RID A-2398-2009  

E-Print Network (OSTI)

Charm elliptic flow in heavy-ion collisions at the Relativistic Heavy Ion Collider is studied in a multiphase transport model. Assuming that the cross section for charm quark scattering with other light quarks is the same as that between light quarks, we find that both charm and light quark elliptic flows are sensitive to the value of the cross section. Compared to that of light quarks, the elliptic flow of charm quarks is smaller at low transverse momentum but approaches comparable values at high transverse momentum. Similar features are seen in the elliptic flow of charmed mesons as well as that of the electrons from their semileptonic decays when the charmed mesons are produced from quark coalescence during hadronization of the partonic matter. To describe the large electron elliptic flow observed in available experimental data requires a charm quark-scattering cross section that is much larger than that given by the perturbative quantum chromodynamics.

Zhang, B.; Chen, LW; Ko, Che Ming.

2005-01-01T23:59:59.000Z

27

Identity method to study chemical fluctuations in relativistic heavy-ion collisions  

Science Conference Proceedings (OSTI)

Event-by-event fluctuations of the chemical composition of the hadronic final state of relativistic heavy-ion collisions carry valuable information on the properties of strongly interacting matter produced in the collisions. However, in experiments incomplete particle identification distorts the observed fluctuation signals. The effect is quantitatively studied and a new technique for measuring chemical fluctuations, the identity method, is proposed. The method fully eliminates the effect of incomplete particle identification. The application of the identity method to experimental data is explained.

Gazdzicki, Marek; Grebieszkow, Katarzyna; Mackowiak, Maja; Mrowczynski, Stanislaw [Goethe-Universitaet Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt am Main, Germany, and Institute of Physics, Jan Kochanowski University, ul. SwiePtokrzyska 15, PL-25-406 Kielce (Poland); Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, PL-00-662 Warszawa (Poland); Institute of Physics, Jan Kochanowski University, ul. SwiePtokrzyska 15, PL-25-406 Kielce (Poland) and Soltan Institute for Nuclear Studies, ul. Hoza 69, PL-00-681 Warszawa (Poland)

2011-05-15T23:59:59.000Z

28

Fourth workshop on experiments and detectors for a relativistic heavy ion collider  

Science Conference Proceedings (OSTI)

This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4{pi} tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/{psi} detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector.

Fatyga, M.; Moskowitz, B. (eds.)

1990-01-01T23:59:59.000Z

29

Alternative Scenarios of Relativistic Heavy-Ion Collisions: I. Baryon Stopping  

E-Print Network (OSTI)

Simulations of relativistic heavy-ion collisions within the three-fluid model employing a purely hadronic equation of state (EoS) and two versions of the EoS involving deconfinement transition are presented. The latter are an EoS with the first-order phase transition and that with a smooth crossover transition. The model setup is described in detail. The analysis is performed in a wide range of incident energies 2.7 GeV $energy. Results on proton and net-proton rapidity distributions are reported. Comparison with available data indicate certain preference of the crossover EoS. It is found that predictions within deconfinement-transition scenarios exhibit a "peak-dip-peak-dip" irregularity in the incident energy dependence of the form of the net-proton rapidity distributions in central collisions. This irregularity is a signal of deconfinement onset occurring in the hot and dense stage of the nuclear collision.

Yu. B. Ivanov

2013-02-23T23:59:59.000Z

30

Multiplicity Dependence of Partially Coherent Pion Production in Relativistic Heavy Ion Collisions  

E-Print Network (OSTI)

We investigate two- and three-particle intensity correlation functions of pions in relativistic heavy ion collisions for different colliding energies. Based on three models of particle production, we analyze the degree to which the pion sources are chaotic in the SPS S+Pb, Pb+Pb and the RHIC Au+Au collisions. The ``chaoticity'', $\\lambda$, of the two-particle correlation functions is corrected for long-lived resonance decays. The effect of the partial Coulomb correction is also examined. Although the partially coherent model gives a result which is consistent with that of STAR, the chaotic fraction does not exhibit clear multiplicity dependence if we take into account both the corrected chaoticity and the weight factor of the three-pion correlation function. The result of the partially-multicoherent model indicates an increasing number of coherent sources in higher multiplicity events.

Kenji Morita; Shin Muroya; Hiroki Nakamura

2006-02-04T23:59:59.000Z

31

Relativistic heavy ion physics. Progress report, November 15, 1992--November 14, 1993  

SciTech Connect

This is a progress report for the period May 1992 through April 1993. The first section, entitled ``Purpose and Trends, gives background on the recent trends in the research program and its evolution from an emphasis on nuclear structure physics to its present emphasis on relativistic heavy ion and RHIC physics. The next section, entitled ``Physics Research Progress``, is divided into four parts: participation in the program to develop a large detector named PHENIX for the RHIC accelerator; joining E864 at the AGS accelerator and the role in that experiment; progress made in the study of electromagnetic dissociation highlight of this endeavor is an experiment carried out with the {sup 197}Au beam from the AGS accelerator in April 1992; progress in completion of the nuclear structure studies. In the final section a list of publications, invited talks, and contributed talks is given.

Hill, J.C.; Wohn, F.K.

1993-11-01T23:59:59.000Z

32

Turbulent pattern formation and diffusion in the early-time dynamics in the relativistic heavy-ion collision  

E-Print Network (OSTI)

We propose a picture of turbulent pattern formation in the relativistic heavy-ion collision, which follows an efficient process to break color strings and dispose energy in the whole phase space. We perform numerical simulations using the SU(2) pure Yang-Mills theory in a non-expanding box to observe a dynamical phenomenon in the transverse plane akin to the domain growth in time-dependent spin systems.

Kenji Fukushima

2013-07-03T23:59:59.000Z

33

Measurements of phi meson production in relativistic heavy-ion collisions at RHIC  

Science Conference Proceedings (OSTI)

We present results for the measurement of {phi} meson production via its charged kaon decay channel {phi} {yields} K{sup +}K{sup -} in Au + Au collisions at {radical}s{sub NN} = 62.4, 130, and 200 GeV, and in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (|y| energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for {phi} production at RHIC. The {Omega}/{phi} yield ratio as a function of p{sub T} is consistent with a model based on the recombination of thermal s quarks up to p{sub T} {approx} 4 GeV/c, but disagrees at higher transverse momenta. The measured nuclear modification factor, R{sub dAu}, for the {phi} meson increases above unity at intermediate p{sub T}, similar to that for pions and protons, while R{sub AA} is suppressed due to the energy loss effect in central Au + Au collisions. Number of constituent quark scaling of both R{sub cp} and v{sub 2} for the {phi} meson with respect to other hadrons in Au + Au collisions at {radical}s{sub NN} = 200 GeV at intermediate p{sub T} is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate p{sub T} region at RHIC.

STAR Coll

2009-06-16T23:59:59.000Z

34

PREVENTING POLLUTION USING ISO 14001 AT A PARTICLE ACCELERATOR THE RELATIVISTIC HEAVY ION COLLIDER PROJECT.  

SciTech Connect

In early 1997 Brookhaven National Laboratory (BNL) discovered that the spent fuel pool of their High Flux Beam Reactor was leaking tritium into the groundwater. Community members, activist groups, politicians and regulators were outraged with the poor environmental management practices at BNL. The reactor was shut down and the Department of Energy (DOE) terminated the contract with the existing Management Company. At this same time, a major new scientific facility, the Relativistic Heavy Ion Collider (RHIC), was nearing the end of construction and readying for commissioning. Although environmental considerations had been incorporated into the design of the facility; some interested parties were skeptical that this new facility would not cause significant environmental impacts. RHIC management recognized that the future of its operation was dependent on preventing pollution and allaying concerns of its stakeholders. Although never done at a DOE National Laboratory before Brookhaven Science Associates, the new management firm, committed to implementing an Environmental Management System (EMS) and RHIC managers volunteered to deploy it within their facility on an extremely aggressive schedule. Several of these IS0 requirements contribute directly to preventing pollution, an area where particular emphasis was placed. This paper describes how Brookhaven used the following key IS0 14001 elements to institutionalize Pollution Prevention concepts: Environmental Policy, Aspects, Objectives and Targets, Environmental Management Program, Structure and Responsibility, Operational Controls, Training, and Management Review. In addition, examples of implementation at the RHIC Project illustrate how BNL's premiere facility was able to demonstrate to interested parties that care had been taken to implement technological and administrative controls to minimize environmental impacts, while at the same time reduce the applicability of regulatory requirements to their operations.

BRIGGS,S.L.K.; MUSOLINO,S.V.

2001-06-01T23:59:59.000Z

35

Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider  

E-Print Network (OSTI)

We have studied the time evolution of the heavy ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC), at BNL, and in the Large Hadron Collider (LHC), at CERN. First, we present measurements from a large number of RHIC stores (from Run 7), colliding 100 GeV/nucleon Au beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the RF bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future Pb beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

R. Bruce; M. Blaskiewicz; W. Fischer; J. M. Jowett

2010-09-08T23:59:59.000Z

36

Sorting chromatic sextupoles for easily and effectively correcting second order chromaticity in the Relativistic Heavy Ion Collider  

Science Conference Proceedings (OSTI)

Based on the contributions of the chromatic sextupole families to the half-integer resonance driving terms, we discuss how to sort the chromatic sextupoles in the arcs of the Relativistic Heavy Ion Collider (RHIC) to easily and effectively correct the second order chromaticities. We propose a method with 4 knobs corresponding to 4 pairs of chromatic sextupole families to online correct the second order chromaticities. Numerical simulation justifies this method, showing that this method reduces the unbalance in the correction strengths of sextupole families and avoids the reversal of sextupole polarities. Therefore, this method yields larger dynamic apertures for the proposed RHIC 2009 100GeV polarized proton run lattices.

Luo,Y.; Tepikian, S.; Fischer, W.; Robert-Demolaize, G.; Trbojevic, D.

2009-01-02T23:59:59.000Z

37

Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"  

E-Print Network (OSTI)

Experimental Physics with Relativistic Heavy Ions dates from 1992 when a beam of 197Au of energy greater than 10A GeV/c first became available at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A GeV/c at the Super Proton Synchrotron (SPS) at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac in the late 1970's and early 1980's were at much lower bombarding energies (~ 1 A GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the Relativistic Heavy Ion Collider (RHIC) at BNL has produced head-on collisions of two 100A GeV beams of fully stripped Au ions, corresponding to nucleon-nucleon center-of-mass energy, sqrt(sNN)=200 GeV, total c.m. energy 200A GeV. The objective of this research program is to produce nuclear matter with extreme density and temperature, possibly resulting in a state of matter where the quarks and gluons normally confined inside individual nucleons (r laboratories: "A new state of matter", by CERN on Feb 10, 2000 and "The perfect fluid", by BNL on April 19, 2005.

M. J. Tannenbaum

2006-03-01T23:59:59.000Z

38

Heavy-quark probes of the quark-gluon plasma and interpretation of recent data taken at the BNL Relativistic Heavy Ion Collider  

E-Print Network (OSTI)

Thermalization and collective flow of charm (c) and bottom (b) quarks in ultrarelativistic heavy-ion collisions are evaluated based on elastic parton rescattering in an expanding quark-gluon plasma (QGP). We show that resonant interactions in a strongly interacting QGP (sQGP), as well as parton coalescence, can play an essential role in the interpretation of recent data from the BNL Relativistic Heavy-Ion Collider (RHIC), and thus illuminate the nature of the sQGP and its hadronization. Our main assumption, motivated by recent findings in lattice quantum chromodynamics, is the existence of D- and B-meson states in the sQGP, providing resonant cross sections for heavy quarks. Pertinent drag and diffusion coefficients are implemented into a relativistic Langevin simulation to compute transverse-momentum spectra and azimuthal asymmetries (v(2)) of b- and c-quarks in Au-Au collisions at RHIC. After hadronization into D- and B-mesons using quark coalescence and fragmentation, associated electron-decay spectra and v(2) are compared to recent RHIC data. Our results suggest a reevaluation of radiative and elastic quark energy-loss mechanisms in the sQGP.

van Hees, H.; Greco, V.; Rapp, Ralf.

2006-01-01T23:59:59.000Z

39

Alternative Scenarios of Relativistic Heavy-Ion Collisions: II. Particle Production  

E-Print Network (OSTI)

Particle production in relativistic collisions of heavy nuclei is analyzed in a wide range of incident energies 2.7 GeV $\\le \\sqrt{s_{NN}}\\le$ 62.4 GeV. The analysis is performed within the three-fluid model employing three different equations of state (EoS): a purely hadronic EoS, an EoS with the first-order phase transition and that with a smooth crossover transition. It is found that the hadronic scenario fails to reproduce experimental yields of antibaryons (strange and nonstrange), starting already from lower SPS energies, i.e. $\\sqrt{s_{NN}}>$ 5 GeV. Moreover, at energies above the top SPS one, i.e. $\\sqrt{s_{NN}}>$ 17.4 GeV, the mid-rapidity densities predicted by the hadronic scenario considerably exceed the available RHIC data on all species. At the same time the deconfinement-transition scenarios reasonably agree (to a various extent) with all the data. The present analysis demonstrates certain advantage of the deconfinement-transition EoS's. However, all scenarios fail to reproduce the strangeness enhancement in the incident energy range near 30A GeV (i.e. a horn anomaly in the $K^+/\\pi^+$ ratio) and yields of $\\phi$-mesons at 20A--40A GeV.

Yu. B. Ivanov

2013-04-05T23:59:59.000Z

40

Effect of the Wood-Saxon nuclear distribution on the chiral magnetic field in Relativistic Heavy-ion Collisions  

E-Print Network (OSTI)

The formation of the QCD vacuum with nonzero winding number $Q_w$ during relativistic heavy-ion collisions breaks the parity and charge-parity symmetry. A new kind of field configuration can separate charge in the presence of a background magnetic field-the "chiral magnetic effect". The strong magnetic field and the QCD vacuum can both completely be produced in the noncentral nuclear-nuclear collision. Basing on the theory of Kharzeev,Mclerran and Warringa, we use the Wood-Saxon nucleon distribution to replace that of the uniform distribution to improve the magnetic field calculation method of the noncentral collision. The chiral magnetic field distribution at LHC(Large Hadron Collider) energy regions are predicted. We also consider the contributions to the magnetic field of the total charge given by the produced quarks.

Yu-Jun Mo; Sheng-Qin Feng; Ya-Fei Shi

2013-08-20T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Particle production in strong electromagnetic fields in relativistic heavy-ion collisions  

E-Print Network (OSTI)

I review the origin and properties of electromagnetic fields produced in heavy ion collisions. The field strength immediately after a collision is proportional to the collision energy and reaches eB\\sim(m_\\pi)^2 at RHIC and eB\\sim10 (m_\\pi)^2 at LHC. I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma exists as a consequence of finite electrical conductivity of the plasma. Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane and therefore all kinetic coefficients are anisotropic. I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry. Very strong electromagnetic field has an important impact on particle production. I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate J/Psi dissociation via Lorentz ionization mechanism and examine electromagnetic radiation by plasma. I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation.

Kirill Tuchin

2013-01-01T23:59:59.000Z

42

Vector meson production in coherent hadronic interactions: Update on predictions for energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider  

SciTech Connect

In this Rapid Communication we update our predictions for the photoproduction of vector mesons in coherent pp and AA collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies using the color dipole approach and the Color Glass Condensate formalism. In particular, we present our predictions for the first run of the LHC at half energy and for the rapidity dependence of the ratio between the J/{Psi} and {rho} cross sections at RHIC energies.

Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Machado, M. V. T. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2011-07-15T23:59:59.000Z

43

Analysis of the baryon-, proton-, and charged particle kurtosis in heavy ion collisions within a relativistic transport approach  

E-Print Network (OSTI)

We explore the potential of recent lattice QCD predictions on net baryon number, net charge and net proton fluctuations (in terms of an effective kurtosis) to investigate the properties of hot and dense matter created in relativistic heavy ion reactions. Lattice QCD suggests a value for the baryon number fluctuation between 0 and 1, depending whether the system is in the hadron gas phase or in the quark gluon phase. The present analysis is performed on simulated events taking into account realistic fluctuations due to stopping, resonance decays, etc. while conserving electric and baryon charge exactly on an event-by-event basis. The investigations are performed within the UrQMD framework for Pb+Pb reactions in the energy range from E_lab = 20A to 158A GeV. We find that the effective kurtosis of net proton fluctuations (being experimentally more feasible than net baryon fluctuations) around midrapidity are compatible with 0 +/- 1. However, the baryon number effective kurtosis is found to be negative in the who...

Schuster, Tim; Mitrovski, Michael; Stock, Reinhard; Bleicher, Marcus

2009-01-01T23:59:59.000Z

44

Photodetachment of relativistic ions  

Science Conference Proceedings (OSTI)

A series of fundamental laser ion beam experiments has been made feasible by the high-quality, relativistic (..beta.. = 0.842) H/sup -/ ion beam available at the Clinton P. Anderson Meson Physics Facility (LAMPF). The relatavistic Doppler shift of the light from an ordinary ultraviolet laser provides what is, in effect, a continuously tunable vacuum-ultraviolet laser in the rest frame of the moving ions. The Lorentz transformation of a modest laboratory magnetic field provides an electric field of several megavolts/centimeter. The latest results of photo-detachment work with H/sup -/ beams and our spectroscopic work with H/sup 0/ beams are presented. Plans for future work are discussed.

Donahue, J.B.; Gram, P.A.M.; Hamm, M.E.; Hamm, R.W.; Bryant, H.C.; Butterfield, K.B.; Clark, D.A.; Frost, C.A.; Smith, W.W.

1980-01-01T23:59:59.000Z

45

RELATIVISTIC HEAVY ION EXPERIMENTS  

E-Print Network (OSTI)

ve for the study of very high energy nucleus-nucleus collisions is to observe the properties of nuclear

Pugh, H.G.

2010-01-01T23:59:59.000Z

46

Relativistic heavy ions physics  

SciTech Connect

Central nuclear collisions at energies far above 1 GeV/nucleon may provide for conditions, where the transition from highly excited hadronic matter into quark matter or quark-gluon plasma can be probed. We review current ideas about the nature of, and signals for, this transition, and we discuss the (hadronic) string model approach to the nuclear collisions dynamics. At even higher energies in the TeV/nucleon range peripheral nuclear collisions may become a laboratory for electroweak physics at the unification scale allowing, e.g., for Higgs boson production. 42 refs., 29 figs.,

Mueller, B.

1989-01-01T23:59:59.000Z

47

Heavy-Ion Physics with CMS  

E-Print Network (OSTI)

This article presents a brief overview of the CMS experiment capabilities to study the hot and dense matter created in relativistic heavy-ion collisions. The CERN Large Hadron Collider will provide collisions of Pb nuclei at 5.5 TeV per nucleon. The CMS heavy ion group has developed a plethora of physics analyses addressing many important aspects of heavy-ion physics in preparation for a competitive and successful program.

Aneta Iordanova

2008-06-06T23:59:59.000Z

48

Strange quark suppression and strange hadron production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider  

Science Conference Proceedings (OSTI)

The parton and hadron cascade model PACIAE based on PYTHIA is utilized to systematically investigate strange particle production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). Globally speaking, the PACIAE results of the strange particle rapidity density at midrapidity and the transverse momentum distribution are better than those of PYTHIA (default) in comparison with STAR and ALICE experimental data. This may represent the importance of the parton and hadron rescatterings, as well as the reduction mechanism of strange quark suppression, added in the PACIAE model. The K/{pi} ratios as a function of reaction energy in pp collisions from CERN Super Proton Synchrotron (SPS) to LHC energies are also analyzed in this paper.

Long Haiyan; Feng Shengqin; Zhou Daimei; Yan Yuliang; Ma Hailiang; Sa Benhao [Department of Physics, College of Science, China Three Gorges University, Yichang 443002 (China); Institute of Particle Physics, Huazhong Normal University, Wuhan 430082 (China); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); Institute of Particle Physics, Huazhong Normal University, Wuhan 430082 (China); CCAST (World Laboratory), P.O. Box 8730, Beijing 100080 (China)

2011-09-15T23:59:59.000Z

49

Effect of jets on $v_4/v_2^2$ ratio and constituent quark scaling in relativistic heavy-ion collisions  

E-Print Network (OSTI)

The Monte Carlo HYDJET++ model, that combines parametrized hydrodynamics with jets, is employed to study formation of second v_2 and fourth v_4 components of the anisotropic flow in ultrarelativistic heavy-ion collisions at energies of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), sqrt{s}=200 AGeV and sqrt{s}=2.76 ATeV, respectively. It is shown that the quenched jets contribute to the soft part of the v_2(p_T) and v_4(p_T) spectra. The jets increase the ratio v_4/v_2^2 thus leading to deviations of the ratio from the value of 0.5 predicted by the ideal hydrodynamics. Together with the event-by-event fluctuations, the influence of jets can explain quantitatively the ratio v_4/v_2^2 at p_T energies and qualitatively the rise of its high-p_T tail at LHC. Jets are also responsible for violation of the number-of-constituent-quark (NCQ) scaling at LHC despite the fact that the scaling is fulfilled for the hydro-part of particle spectra.

L. Bravina; B. H. Brusheim Johansson; G. Eyyubova; E. Zabrodin

2013-02-26T23:59:59.000Z

50

Effect of jets on $v_4/v_2^2$ ratio and constituent quark scaling in relativistic heavy-ion collisions  

E-Print Network (OSTI)

The Monte Carlo HYDJET++ model, that combines parametrized hydrodynamics with jets, is employed to study formation of second v_2 and fourth v_4 components of the anisotropic flow in ultrarelativistic heavy-ion collisions at energies of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), sqrt{s}=200 AGeV and sqrt{s}=2.76 ATeV, respectively. It is shown that the quenched jets contribute to the soft part of the v_2(p_T) and v_4(p_T) spectra. The jets increase the ratio v_4/v_2^2 thus leading to deviations of the ratio from the value of 0.5 predicted by the ideal hydrodynamics. Together with the event-by-event fluctuations, the influence of jets can explain quantitatively the ratio v_4/v_2^2 at p_T energies and qualitatively the rise of its high-p_T tail at LHC. Jets are also responsible for violation of the number-of-constituent-quark (NCQ) scaling at LHC despite the fact that the scaling is fulfilled for the hydro-part of particle spectra.

Bravina, L; Eyyubova, G; Zabrodin, E

2013-01-01T23:59:59.000Z

51

Probing the direct step of relativistic heavy ion fragmentation: (/sup 12/C, /sup 11/B+p) at 2. 1 GeV/nucleon with C and CH/sub 2/ targets  

DOE Green Energy (OSTI)

Relativistic heavy ion collisions may be classified as central (and near central), peripheral, and grazing with each collision type producing different proton and other charged projectile fragment scattering mechanisms and characteristics. This report focuses on peripheral and grazing collisions in the fragmentation of Carbon-12 into Boron-11 and a proton, testing models of the kinetics involved in this reaction. The data were measured at the Heavy Ion Superconducting Spectrometer (HISS) at Lawrence Berkeley Laboratory and include excitation energy for the p/Boron-11 pair, and rapidity versus transverse momentum for protons and Boron-11. 58 refs., 35 figs., 8 tabs. (DWL)

Webb, M.L.

1987-06-01T23:59:59.000Z

52

Head shock vs Mach cone: azimuthal correlations from 2 to 3 parton processes in relativistic heavy-ion collisions  

E-Print Network (OSTI)

We study the energy-momentum deposited by fast moving partons within a medium using linearized viscous hydrodynamics. The particle distribution produced by this energy-momentum is computed using the Cooper-Frye formalism. We show that for the conditions arising in heavy-ion collisions, energy momentum is preferentially deposited along the head shock of the fast moving partons. We also show that the double hump in the away-side of azimuthal correlations can be produced by two (instead of one) away-side partons that deposit their energy-momentum along their directions of motion. These partons are originated in the in-medium hard scattering in 2 to 3 processes. We compare the results of the analysis to azimuthal angular correlations from PHENIX and show that the calculation reproduces the data systematics of a decreasing away-side correlation when the momentum of the associated hadron becomes closer to the momentum of the leading hadron. This scenario seems to avoid the shortcomings of the Mach cone as the origin of the double-hump structure in the away-side

Alejandro Ayala; Isabel Dominguez; Maria Elena Tejeda-Yeomans

2012-12-05T23:59:59.000Z

53

PROCEEDINGS OF THE SECOND WORKSHOP ON EXPERIMENTS AND DETECTORS FOR A RELATIVISTIC HEAVY ION COLLIDER (RHIC), LAWRENCE BERKELEY LABORATORY, MAY 25-29, 1987  

E-Print Network (OSTI)

Heavy-Ion Collider. Brookhaven National Lab.. Upton N.Y. (Zingman Lawrence Berkeley Laboratory Brookhaven NationalLaboratory Brookhaven National Laboratory Johns Hopkins

Ritter, Hans Georg

2010-01-01T23:59:59.000Z

54

A Large-scale Relativistic Configuration-Interaction Calculation for the 4s-4p Transition Energies of Copperlike Heavy Ions  

Science Conference Proceedings (OSTI)

The 4s-4p transition energies for high-Z copperlike ions are calculated using the relativistic configuration-interaction (RCI) method. These calculations are based on the relativistic no-pair Hamiltonian which includes Coulomb and frequency-dependent, retarded Breit interactions and use B-spline orbitals as basis functions. Mass polarization and quantum electrodynamic (QED) corrections are also calculated. The present RCI energies agree very well with results from the relativistic many-body perturbation theory. With QED corrections included, our total transition energies are in very good agreement with recent high-precision measurements.

Cheng, K T; Chen, M H

2005-06-30T23:59:59.000Z

55

THE RELATIVISTIC HEAVY ION COLLIDER (RHIC) REFRIGERATOR SYSTEM AT BROOKHAVEN NATIONAL LABORATORY: PHASE III OF THE SYSTEM PERFORMANCE AND OPERATIONS UPGRADES FOR 2003  

SciTech Connect

An ongoing program at Brookhaven National Laboratory (BNL) consists of improving the efficiency of the Relativistic Heavy Ion Collider (RHIC) cryogenic system and reducing its power consumption. Phase I and I1 of the program addressed plant operational improvements and modifications that resulted in substantial operational cost reduction and improved system reliability and stability, and a compressor input power reduction of 2 MW has been demonstrated. Phase 111, now under way, consists of plans for further increasing the efficiency of the plant by adding a load ''wet'' turbo-expander and its associated heat exchangers at the low temperature end of the plant. This additional stage of cooling at the coldest level will further reduce the required compressor flow and therefore compressor power input. This paper presents the results of the plant characterization, as it is operating presently, as well as the results of the plant simulations of the various planned upgrades for, the plant. The immediate upgrade includes the changes associated with the load expander. The subsequent upgrade will involve the resizing of expander 5 and 6 to increase their efficiencies. The paper summarizes the expected improvement in the plant efficiency and the overall reduction in the compressor power.

SIDI-YEKHLEF,A.; TUOZZOLO,J.; THAN, R.; KNUDSEN, P.; ARENIUS, D.

2005-08-29T23:59:59.000Z

56

Net-baryon-, net-proton-, and net-charge kurtosis in heavy-ion collisions within a relativistic transport approach  

E-Print Network (OSTI)

We explore the potential of net-baryon, net-proton and net-charge kurtosis measurements to investigate the properties of hot and dense matter created in relativistic heavy-ion collisions. Contrary to calculations in a grand canonical ensemble we explicitly take into account exact electric and baryon charge conservation on an event-by-event basis. This drastically limits the width of baryon fluctuations. A simple model to account for this is to assume a grand-canonical distribution with a sharp cut-off at the tails. We present baseline predictions of the energy dependence of the net-baryon, net-proton and net-charge kurtosis for central ($b\\leq 2.75$ fm) Pb+Pb/Au+Au collisions from $E_{lab}=2A$ GeV to $\\sqrt{s_{NN}}=200$ GeV from the UrQMD model. While the net-charge kurtosis is compatible with values around zero, the net-baryon number decreases to large negative values with decreasing beam energy. The net-proton kurtosis becomes only slightly negative for low $\\sqrt{s_{NN}}$.

Marlene Nahrgang; Tim Schuster; Michael Mitrovski; Reinhard Stock; Marcus Bleicher

2009-03-17T23:59:59.000Z

57

HEAVY ION INERTIAL FUSION  

E-Print Network (OSTI)

Accelerators as Drivers for Inertially Confined Fusion, W.B.LBL-9332/SLAC-22l (1979) Fusion Driven by Heavy Ion Beams,OF CALIFORNIA f Accelerator & Fusion Research Division

Keefe, D.

2008-01-01T23:59:59.000Z

58

Heavy ion fusion--Using heavy ions to make electricity  

E-Print Network (OSTI)

in Proc. of the Inertial Fusion Science and ApplicationsP. Abbott, P. F. Peterson, Fusion Science and Technology 44March 1520, 2004 Heavy Ion Fusion Using Heavy Ions to Make

Celata, C.M.

2004-01-01T23:59:59.000Z

59

Solenoid transport for heavy ion fusion  

E-Print Network (OSTI)

Transport for Heavy Ion Fusion* Edward Lee** LawrenceHm Heavy Ion Inertial Fusion Abstract Solenoid transport ofseveral stages of a heavy ion fusion driver. In general this

Lee, Edward

2004-01-01T23:59:59.000Z

60

HEAVY ION LINEAR ACCELERATOR  

DOE Patents (OSTI)

A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

Van Atta, C.M.; Beringer, R.; Smith, L.

1959-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Heavy Ions - Cyclotron  

NLE Websites -- All DOE Office Websites (Extended Search)

Heavy Ions Heavy Ions Heavy ions used at the BASE Facility are accelerated in the form of "cocktails," named because of the fact that several heavy ions with the same mass-to-charge ratio are sent into the Cyclotron, which accelerates the ions while acting as a precision mass separator. The Control Room Operator then uses Cyclotron frequency to select only the desired ion, a process that takes about 2 minutes. We provide four standard cocktails: 4.5, 10, 16, and 30 MeV/nucleon. Depending on the cocktail, LETs from 1 to 100 MeV/(mg/cm^2) and flux levels of up to 1E7 ions/cm2-sec are available. Parts are tested in our vacuum chamber, and can be remotely positioned horizontally, vertically, or rotationally (y and z axes) with the motion table. An alignment laser is available to ensure the part is in the center of the beam. Mounting hardware is readily available. 12xBNC (F-F), 2x25-pin D (F-M or M-F), 4x40-pin flat ribbon (M-M), 4x50-pin flat ribbon (M-M), 12xSMA (F-F), and 2xEthernet vacuum feedthroughs are mounted upon request. (The 4x40-pin and 4x50-pin flat ribbon connectors are wired straight across, so you will need a F-F adapter to correct the pin numbers to normal.) Holes are provided through the cave shielding blocks for connecting additional test equipment, with a distance of approximately 10 feet from vacuum feedthrough to the top of the shielding block.

62

Ratios of heavy baryons to heavy mesons in relativistic nucleus-nucleus collisions  

E-Print Network (OSTI)

Heavy baryon/meson ratios Lambda(c)/D(0) and Lambda(b)/(B) over bar (0) in relativistic heavy ion collisions are studied in the quark coalescence model. For heavy baryons, we include production from coalescence of heavy quarks with free light quarks as well as with bounded light diquarks that might exist in the strongly coupled quark-gluon plasma produced in these collisions. Including the contribution from decays of heavy hadron resonances and also that due to fragmentation of heavy quarks that are left in the system after coalescence, the resulting Lambda(c)/D(0) and Lambda(b)/(B) over bar (0) ratios in midrapidity (vertical bar y vertical bar heavy baryon/meson ratios is found to be sensitive to the heavy quark mass, with the Lambda(b)/(B) over bar (0) ratio being much flatter than the Lambda(c)/D(0) ratio. The latter peaks at the transverse momentum p(T) similar or equal to 0.8 GeV but the peak shifts to p(T) similar or equal to 2 GeV in the absence of diquarks.

Oh, Yongseok; Ko, Che Ming; Lee, Su Houng; Yasui, Shigehiro.

2009-01-01T23:59:59.000Z

63

ULTRARELATIVISTIC HEAVY IONS  

E-Print Network (OSTI)

energy density and flux, the general behavior of space time in collisions, relativistic nuclear theory, and

Pugh, H.G.

2010-01-01T23:59:59.000Z

64

Characterizing Heavy Ion  

NLE Websites -- All DOE Office Websites (Extended Search)

Heavy Ion Heavy Ion Reactions in the 1980's Is there Treasure at the end of the Rainbow? & What happens and how do different modes compete? John Schiffer One of the three research areas for ATLAS, as stated in a 1984 document to Congress: Are there some new marvelous symmetries, hidden in resonances in heavier nuclei, beyond 12 C+ 12 C and its immediate vicinity? (s.c. linac work, pre-ATLAS) Other attempts to chase the rainbow 180 o elastic scattering of 12 C on 40 Ca shows structure Fusion of 16 O on 40 Ca does not. In the end, it seemed that these structures were sometimes present in alpha-particle nuclei, but almost never in others. Some optimists, continued the pursuit. We also looked at the total fusion cross section in systems that showed resonances in scattering.

65

DEDICATED HEAVY ION MEDICAL ACCELERATORS  

E-Print Network (OSTI)

et al. , ,8iological and Medical Research with Acceleratedet al. , "Biological and Medical Research with J\\cceleratedic Heavy Ions in Medical and Scientific Research, Edmonton,

Gough, R.A.

2013-01-01T23:59:59.000Z

66

Heavy Ion Fusion development plan  

SciTech Connect

Some general cnsiderations in the fusion development program are given. The various factors are considered that must be determined before heavy ion fusion can be assessed. (MOW)

Maschke, A.W.

1978-01-01T23:59:59.000Z

67

Very high energy heavy-ion accelerators  

SciTech Connect

A review is given of various programs for building heavy ion accelerators. Topics discussed are (1) options of reaching very high energies with heavy ions; (2) present performance of the superHILAC and the Bevalac; (3) heavy ion sources; (4) applications of heavy ion accelerators outside of basic research; and (5) reliability and operating costs of heavy ion sources. (PMA)

Grunder, H.A.

1975-10-01T23:59:59.000Z

68

SYNCHROTRONS FOR HEAVY IONS - BEVALAC EXPERIENCE  

E-Print Network (OSTI)

Heavy Ions ir. Medical and Scientific Research", Edmonton,Heavy Ions in Medical and Scientific Research" Edmonton,vigorous medical and nuclear science research groups. The

Grunder, H.A.

2010-01-01T23:59:59.000Z

69

Heavy ion fusion--Using heavy ions to make electricity  

E-Print Network (OSTI)

for a practical fusion power reactor. HIF is the only fusionenter the reactor chamber, and focus Heavy Ion Fusion ontoengineering test reactor. The promise of fusion as a power

Celata, C.M.

2004-01-01T23:59:59.000Z

70

Heavy Ion Collisions at RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

at Heavy Ion Colliders at Heavy Ion Colliders Theory Drivers & View from LHC Urs Achim Wiedemann CERN PH-TH NSAC Implementation Subcommittee Hearings 7 September 2012 Heavy Ion Physics - Main Tools of Theorists Understanding properties of hot and dense matter from the elementary interactions in QCD High Energy Physics String Theory Computational Physics Fluid Dynamics Dissipative fluid dynamic description * Based on: E-p conservation: 2 nd law of thermodynamics: * Sensitive to properties of matter that are calculated from first principles in quantum field theory - EOS: and sound velocity - transport coefficients: shear , bulk viscosity, conductivities ...

71

Accelerators for heavy ion fusion  

SciTech Connect

Large fusion devices will almost certainly produce net energy. However, a successful commercial fusion energy system must also satisfy important engineering and economic constraints. Inertial confinement fusion power plants driven by multi-stage, heavy-ion accelerators appear capable of meeting these constraints. The reasons behind this promising outlook for heavy-ion fusion are given in this report. This report is based on the transcript of a talk presented at the Symposium on Lasers and Particle Beams for Fusion and Strategic Defense at the University of Rochester on April 17-19, 1985.

Bangerter, R.O.

1985-10-01T23:59:59.000Z

72

Hadron Production in Heavy Ion Collisions  

E-Print Network (OSTI)

2A GeV 3 Hadron Production from AGS to RHIC 3.1 SystematicsHadron Production in Heavy Ion Collisions Hans Georg RitterAC02- 05CH11231. Hadron Production in Heavy Ion Collisions

Ritter, Hans Georg

2009-01-01T23:59:59.000Z

73

Heavy Ion Physics and Quark-Gluon Plasma  

E-Print Network (OSTI)

These proceedings represent a brief overview of the exciting physics coming out from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The experimental results from BRAHMS, PHOBOS, PHENIX and STAR indicate a strongly-coupled state of matter that can only be described on the partonic level. Here we review some of the latest experimental results as presented at the meeting of the Division of Particles and Fields of the American Physical Society in Riverside, CA in August 2004.

J. L. Nagle

2004-11-15T23:59:59.000Z

74

HEAVY-ION RADIOGRAPHY AND HEAVY-ION COMPUTED TOMOGRAPHY  

E-Print Network (OSTI)

In: Biological and Medical Research with Accelerated Heavyeds. Biological and Medical Research with Accelerated HeavyIn: Biological and Medical Research with Accelerated Heavy

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

75

Relativistic Heavy Ion Collider Funding Agencies  

NLE Websites -- All DOE Office Websites (Extended Search)

Funding Agencies Funding Agencies In addition to the operations funding received from the Office of Nuclear Physics within the U.S. Department of Energy's Office of Science, RHIC experiments receive funding from a variety of sources PHENIX U.S. National Science Foundation Ministry of Education, Culture, Sports, Science and Technology of Japan Japan Society for the Promotion of Science National Council for Scientific and Technological Development, Brazil Research Supporting Foundation of the State of Sao Paulo, Brazil National Natural Science Foundation of China National Institute of Nuclear Physics and Particle Physics of the National Center for Scientific Research of France Atomic Energy Commission of France ARMINES (France) Federal Ministry of Education and Research of Germany

76

MESON PRODUCTION IN RELATIVISTIC HEAVY ION COLLISIONS  

E-Print Network (OSTI)

Cerenkov Counter 4.1.5 Lead-Glass Blocks 4.1.6 MATRIX f. liand an array of lead glass blocks. Lucite Cerenkov Counter80% of the kaons. Lead-Glass Blocks The array ot lead glass

Schnetzer, S.R.

2010-01-01T23:59:59.000Z

77

Heavy ions and string theory  

E-Print Network (OSTI)

We review a selection of recent developments in the application of ideas of string theory to heavy ion physics. Our topics divide naturally into equilibrium and non-equilibrium phenomena. On the non-equilibrium side, we discuss generalizations of Bjorken flow, numerical simulations of black hole formation in asymptotically anti-de Sitter geometries, equilibration in the dual field theory, and hard probes. On the equilibrium side, we summarize improved holographic QCD, extraction of transport coefficients, inclusion of chemical potentials, and approaches to the phase diagram. We close with some possible directions for future research.

Oliver DeWolfe; Steven S. Gubser; Christopher Rosen; Derek Teaney

2013-04-29T23:59:59.000Z

78

Heavy ion physics at the LHC  

E-Print Network (OSTI)

Heavy Ion Physics at the LHC ? R. VogtLaboratory, Berkeley, CA USA Physics Department, Universityfor addressing unique physics issues in a completely new

Vogt, R.

2004-01-01T23:59:59.000Z

79

On stability of collisional coupling between relativistic electrons and ions in hot plasmas  

Science Conference Proceedings (OSTI)

The collisional coupling of relativistic electrons and non-relativistic ions in hot plasmas has been analysed. It is found that relativistic effects produce a new feature: while the condition T{sub e}75 keV, collisional decoupling between relativistic electrons and ions becomes impossible.

Marushchenko, I.; Azarenkov, N. A. [V. N. Karazin Kharkiv National University, Svobody Sq. 4, 61022 Kharkiv (Ukraine); Marushchenko, N. B. [Max Planck Institute for Plasma Physics, EURATOM Association, Wendelsteinstr. 1, 17491 Greifswald (Germany)

2012-11-15T23:59:59.000Z

80

Production of hypernuclei in peripheral relativistic ion collisions  

E-Print Network (OSTI)

Within a dynamical and statistical approach we study the main regularities in production of hypernuclei coming from projectile and target residues in relativistic ion collisions. We demonstrate that yields of hypernuclei increase considerably above the energy threshold for Lambda hyperons, and there is a saturation for yields of single hypernuclei with increasing the beam energy up to few TeV. Production of specific hypernuclei depend very much on the isotopic composition of the projectile, and this gives a chance to obtain exotic hypernuclei that may be difficult to reach in traditional hypernuclear experiments. Possibilities for the detection of such hypernuclei with planned and available relativistic ion facilities are discussed.

Botvina, A S; Pochodzalla, J

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Heavy Ion Collisions at the LHC - Last Call for Predictions  

SciTech Connect

In August 2006, the CERN Theory Unit announced to restructure its visitor program and to create a 'CERN Theory Institute', where 1-3 month long specific programs can take place. The first such Institute was held from 14 May to 10 June 2007, focusing on 'Heavy Ion Collisions at the LHC - Last Call for Predictions'. It brought together close to 100 scientists working on the theory of ultra-relativistic heavy ion collisions. The aim of this workshop was to review and document the status of expectations and predictions for the heavy ion program at the Large Hadron Collider LHC before its start. LHC will explore heavy ion collisions at {approx} 30 times higher center of mass energy than explored previously at the Relativistic Heavy Ion Collider RHIC. So, on the one hand, the charge of this workshop provided a natural forum for the exchange of the most recent ideas, and allowed to monitor how the understanding of heavy ion collisions has evolved in recent years with the data from RHIC, and with the preparation of the LHC experimental program. On the other hand, the workshop aimed at a documentation which helps to distinguish pre- from post-dictions. An analogous documentation of the 'Last Call for Predictions' [1] was prepared prior to the start of the heavy-ion program at the Relativistic Heavy Ion Collider RHIC, and it proved useful in the subsequent discussion and interpretation of RHIC data. The present write-up is the documentation of predictions for the LHC heavy ion program, received or presented during the CERN TH Institute. The set-up of the CERN TH Institute allowed us to aim for the wide-most coverage of predictions. There were more than 100 presentations and discussions during the workshop. Moreover, those unable to attend could still participate by submitting predictions in written form during the workshop. This followed the spirit that everybody interested in making a prediction had the right to be heard. To arrive at a concise document, we required that each prediction should be summarized on at most two pages, and that predictions should be presented, whenever possible, in figures which display measurable quantities. Full model descriptions were not accepted--the authors were encouraged to indicate the relevant references for the interested reader. Participants had the possibility to submit multiple contributions on different topics, but it was part of the subsequent editing process to ensure that predictions on neighboring topics were merged wherever possible. The contributions summarized here are organized in several sections,--though some of them contain material related with more than one section--roughly by going from low transverse momentum to high transverse momentum and from abundant to rare measurements. In the low transverse momentum regime, we start with predictions on multiplicity distributions, azimuthal asymmetries in particle production and hadronic flavor observables, followed by correlation and fluctuation measurements. The contributions on hard probes at the LHC start with predictions for single inclusive high transverse momentum spectra, and jets, followed by heavy quark and quarkonium measurements, leptonic probes and photons. A final section 'Others' encompasses those predictions which do not fall naturally within one of the above-mentioned categories, or discuss the more speculative phenomena that may be explored at the LHC.

Armesto, N; Borghini, N; Jeon, S; Wiedemann, U A; Abreu, S; Akkelin, V; Alam, J; Albacete, J L; Andronic, A; Antonuv, D; Arleo, F; Armesto, N; Arsene, I C; Barnafoldi, G G; Barrette, J; Bauchle, B; Becattini, F; Betz, B; Bleicher, M; Bluhm, M; Boer, D; Bopp, F W; Braun-Munzinger, P; Bravina, L; Busza, W; Cacciari, M; Capella, A; Casalderrey-Solana, J; Chatterjee, R; Chen, L; Cleymans, J; Cole, B A; delValle, Z C; Csernai, L P; Cunqueiro, L; Dainese, A; de Deus, J D; Ding, H; Djordjevic, M; Drescher, H; Dremin, I M; Dumitru, A; El, A; Engel, R; d' Enterria, D; Eskola, K J; Fai, G; Ferreiro, E G; Fries, R J; Frodermann, E; Fujii, H; Gale, C; Gelis, F; Goncalves, V P; Greco, V; Gyulassy, M; van Hees, H; Heinz, U; Honkanen, H; Horowitz, W A; Iancu, E; Ingelman, G; Jalilian-Marian, J; Jeon, S; Kaidalov, A B; Kampfer, B; Kang, Z; Karpenko, I A; Kestin, G; Kharzeev, D; Ko, C M; Koch, B; Kopeliovich, B; Kozlov, M; Kraus, I; Kuznetsova, I; Lee, S H; Lednicky, R; Letessier, J; Levin, E; Li, B; Lin, Z; Liu, H; Liu, W; Loizides, C; Lokhtin, I P; Machado, M T; Malinina, L V; Managadze, A M; Mangano, M L; Mannarelli, M; Manuel, C; Martinez, G; Milhano, J G; Mocsy, A; Molnar, D; Nardi, M; Nayak, J K; Niemi, H; Oeschler, H; Ollitrault, J; Paic, G; Pajares, C; Pantuev, V S; Papp, G; Peressounko, D; Petreczky, P; Petrushanko, S V; Piccinini, F; Pierog, T; Pirner, H J; Porteboeuf, S; Potashnikova, I; Qin, G Y; Qiu, J; Rafelski, J; Rajagopal, K; Ranft, J; Rapp, R; Rasanen, S S; Rathsman, J; Rau, P; Redlich, K; Renk, T; Rezaeian, A H; Rischke, D; Roesler, S; Ruppert, J; Ruuskanen, P V; Salgado, C A; Sapeta, S; Sarcevic, I; Sarkar, S; Sarycheva, L I; Schmidt, I; Shoski, A I; Sinha, B; Sinyukov, Y M; Snigirev, A M; Srivastava, D K; Stachel, J; Stasto, A; Stocker, H; Teplov, C Y; Thews, R L; Torrieri, G; Pop, V T; Triantafyllopoulos, D N; Tuchin, K L; Turbide, S; Tywoniuk, K; Utermann, A; Venugopalan, R; Vitev, I; Vogt, R; Wang, E; Wang, X N; Werner, K; Wessels, E; Wheaton, S; Wicks, S; Wiedemann, U A; Wolschin, G; Xiao, B; Xu, Z; Yasui, S; Zabrodin, E; Zapp, K; Zhang, B

2008-02-25T23:59:59.000Z

82

Synchrotron radiation by fast fermions in heavy-ion collisions  

SciTech Connect

We study the synchrotron radiation of gluons by fast quarks in strong magnetic field produced by colliding relativistic heavy ions. We argue that due to high electric conductivity of plasma, the magnetic field is almost constant during the entire plasma lifetime. We calculate the energy loss due to synchrotron radiation of gluons by fast quarks. We find that the typical energy loss per unit length for a light quark at the Large Hadron Collider is a few GeV per fm. This effect alone predicts quenching of jets with p{sub perpendicular} up to about 20 GeV. We also show that the spin-flip transition effect accompanying the synchrotron radiation leads to a strong polarization of quarks and leptons with respect to the direction of the magnetic field. Observation of the lepton polarization may provide a direct evidence of existence of strong magnetic field in heavy-ion collisions.

Tuchin, Kirill [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States) and RIKEN BNL Research Center, Upton, New York 11973-5000 (United States)

2010-09-15T23:59:59.000Z

83

Modeling heavy ion ionization loss in the MARS15 code  

E-Print Network (OSTI)

The needs of various accelerator and space projects stimulated recent developments to the MARS Monte Carlo code. One of the essential parts of those is heavy ion ionization energy loss. This paper describes an implementation of several corrections to dE/dx in order to take into account the deviations from the Bethe theory at low and high energies as well as the effect of a finite nuclear size at ultra-relativistic energies. Special attention is paid to the transition energy region where the onset of the effect of a finite nuclear size is observed. Comparisons with experimental data and NIST data are presented.

I. L. Rakhno; N. V. Mokhov; S. I. Striganov

2005-05-05T23:59:59.000Z

84

Ferroelectric Plasma Source for Heavy Ion Beam Charge Neutralization  

E-Print Network (OSTI)

Heavy Ion Beam Driven Fusion Reactor Study, KfK-3480,a possible heavy ion fusion reactor design [1]. The final

2005-01-01T23:59:59.000Z

85

Studies in ion source development for application in heavy ion fusion  

E-Print Network (OSTI)

Ion Sources for Heavy Ion Fusion Applications . Ph.D.Sources for Heavy Ion Fusion . Proceedings of the ParticleDevelopment for Heavy Ion Fusion. Wollnik, H. , Optics of

Kapica, Jonathan G.

2004-01-01T23:59:59.000Z

86

Heavy mesons spectra in a semi-analytical quantum relativistic approach  

SciTech Connect

The obtaining of bound states of heavy and light quarks interacting via a static quark potential is revisited here. We present an approach that both approximate the relativistic wave equation and allows the obtaining of analytical solutions and binding energies (and consequently, the heavy mesons spectra) of the system.

Mota, A. L.; Caldas, H.; Da Fonseca, J. E. [Departamento de Ciencias Naturais, Universidade Federal de Sao Joao del Rei C.P. 110, CEP 36.301-160, Sao Joao del Rei (Brazil)

2013-03-25T23:59:59.000Z

87

Alternative Size and Lifetime Measurements for High-Energy Heavy-Ion Collisions  

E-Print Network (OSTI)

Two-Particle correlations based on the interference of identical particles has provided the chief means for determining the shape and lifetime of sources in relativistic heavy ion collisions. Here, Strong and Coulomb induced correlations are shown to provide equivalent information.

Scott Pratt; Silvio Petriconi

2003-05-07T23:59:59.000Z

88

Microscopic track structure of equal-LET heavy ions  

SciTech Connect

The spatial distributions of ionization and energy deposition produced by heavy (HZE) ions are crucial to an understanding of their radiation quality as exhibited eg., in track segment experiments of cell survival and chromosome aberrations of mammalian cells. The stopping power (or LET) of a high velocity ion is proportional to the ratio Z**2/v**2, apart from a slowly varying logarithmic factor. The maximum delta-ray energy that an ion can produce is proportional to v**2 (non-relativistically). Therefore, two HZE ions having the same LET, but in general differing Z and v will have different maximum delta-ray energies and consequently will produce different spatial patterns of energy deposition along their paths. To begin to explore the implications of this fact for the microscopic dosimetry of heavy ions, we have calculated radial distributions in energy imparted and ionization for iron and neon ions of approximately equal LET in order to make a direct comparison of their delta-ray track structure. Monte Carlo techniques are used for the charged particle radiation transport simulation. 10 refs., 8 figs.

Wilson, W.E.; Criswell, T.L.

1986-07-01T23:59:59.000Z

89

A 3 MEGAJOULE HEAVY ION FUSION DRIVER  

E-Print Network (OSTI)

Research, Office of Inertia! Fusion, Research Division ofA 3 MEGAJOULE HEAVY ION FUSION DRIVER* A. Faltens, E. Hoyer,Research, Office of Inertial Fusion, Research Division of

Faltens, A.

2010-01-01T23:59:59.000Z

90

Hadron Production in Heavy Ion Collisions  

E-Print Network (OSTI)

We review hadron production in heavy ion collisions with emphasis on pion and kaon production at energies below 2 AGeV and on partonic collectivity at RHIC energies.

Helmut Oeschler; Hans Georg Ritter; Nu Xu

2009-08-12T23:59:59.000Z

91

Glenn T. Seaborg and heavy ion nuclear science  

Science Conference Proceedings (OSTI)

Radiochemistry has played a limited but important role in the study of nucleus-nucleus collisions. Many of the important radiochemical studies have taken place in Seaborg's laboratory or in the laboratories of others who have spent time in Berkeley working with Glenn T. Seaborg. I will discuss studies of low energy deep inelastic reactions with special emphasis on charge equilibration, studies of the properties of heavy residues in intermediate energy nuclear collisions and studies of target fragmentation in relativistic and ultrarelativistic reactions. The emphasis will be on the unique information afforded by radiochemistry and the physical insight derived from radiochemical studies. Future roles of radiochemistry in heavy ion nuclear science also will be discussed.

Loveland, W. (Oregon State Univ., Corvallis, OR (United States). Dept. of Chemistry Lawrence Berkeley Lab., CA (United States))

1992-04-01T23:59:59.000Z

92

Glenn T. Seaborg and heavy ion nuclear science  

Science Conference Proceedings (OSTI)

Radiochemistry has played a limited but important role in the study of nucleus-nucleus collisions. Many of the important radiochemical studies have taken place in Seaborg`s laboratory or in the laboratories of others who have spent time in Berkeley working with Glenn T. Seaborg. I will discuss studies of low energy deep inelastic reactions with special emphasis on charge equilibration, studies of the properties of heavy residues in intermediate energy nuclear collisions and studies of target fragmentation in relativistic and ultrarelativistic reactions. The emphasis will be on the unique information afforded by radiochemistry and the physical insight derived from radiochemical studies. Future roles of radiochemistry in heavy ion nuclear science also will be discussed.

Loveland, W. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States)

1992-04-01T23:59:59.000Z

93

GYRAC?D?O: Relativistic plasma accumulator and ion accelerator  

Science Conference Proceedings (OSTI)

Plasma heating and relativistic plasma accumulation are realized in the GYRAC?D?O installation. Relativistic plasma accumulation is a result of plasma heating under synchrotron gyromagnetic autoresonance (SGA) and subsequent throwing of the SGA plasma into the central region of the magnetic mirror trap in the regime of the SGA?pulse packet. The optimum of the initial plasma pulsed injection is found. The obtained plasma is e?vortex filled with ions. Major parameters of the plasma are as follows: n ? 8 109 cm?3: average energy of electrons W?200 keV; lifetime ??40 ms. The problem of the plasma ejection out of the trap after the accumulation cycle completion is discussed. It is shown that effective plasma ejection and ion acceleration are possible in case of a relatively dense plasma which is feasible only in the accumulation regime.

V. V. Andreev; A. A. Apraksin; A. M. Umnov

1992-01-01T23:59:59.000Z

94

High Current Ion Sources and Injectors for Heavy Ion Fusion  

E-Print Network (OSTI)

2001). [40] L.R. Grisham, Fusion Sci. & Tech. 43, 191, (Symp. on Heavy Ion Inertial Fusion, Princeton, New Jersey,Sept. 6-9, 1995; in Fusion Engineering and Design, 32-33,

Kwan, Joe W.

2005-01-01T23:59:59.000Z

95

Heavy flavor in heavy-ion collisions at RHIC and RHIC II  

E-Print Network (OSTI)

In the initial years of operation, experiments at the Relativistic Heavy Ion Collider (RHIC) have identified a new form of matter formed in nuclei-nuclei collisions at energy densities more than 100 times that of a cold atomic nucleus. Measurements and comparison with relativistic hydrodynamic models indicate that the matter thermalizes in an unexpectedly short time, has an energy density at least 15 times larger than needed for color deconfinement, has a temperature about twice the critical temperature predicted by lattice QCD, and appears to exhibit collective motion with ideal hydrodynamic properties - a "perfect liquid" that appears to flow with a near-zero viscosity to entropy ratio - lower than any previously observed fluid and perhaps close to a universal lower bound. However, a fundamental understanding of the medium seen in heavy-ion collisions at RHIC does not yet exist. The most important scientific challenge for the field in the next decade is the quantitative exploration of the new state of nuclear matter. That will require new data that will, in turn, require enhanced capabilities of the RHIC detectors and accelerator. In this report we discuss the scientific opportunities for an upgraded RHIC facility - RHIC II - in conjunction with improved capabilities of the two large RHIC detectors, PHENIX and STAR. We focus solely on heavy flavor probes. Their production rates are calculable using the well-established techniques of perturbative QCD and their sizable interactions with the hot QCD medium provide unique and sensitive measurements of its crucial properties making them one of the key diagnostic tools available to us.

A. D. Frawley; T. Ullrich; R. Vogt

2008-06-05T23:59:59.000Z

96

Physics of Ultra-Relativistic Nuclear Collisions with Heavy Beams at LHC Energy  

E-Print Network (OSTI)

We discuss current plans for experiments with ultra-relativistic nuclear collisions with heavy beams at LHC energy ($\\sqrt{s} = 5.5$ TeV/nucleon pair). Emphasis will be placed on processes which are unique to the LHC program. They include event-by-event interferometry, complete spectroscopy of the $\\Upsilon$ resonances, and open charm and open beauty measurements.

Peter Braun-Munzinger

1999-08-18T23:59:59.000Z

97

Carbon foils as heavy ion strippers  

SciTech Connect

A discussion is given of the advantages and disadvantages of thin carbon foil strippers for heavy ion beams from tandem electrostatic accelerators. Foil lifetimes were increased by radiative heating and by the evaporation of a thin layer of gold on the foil. (PMA)

Yntema, J.L.

1975-01-01T23:59:59.000Z

98

$?$-scaling and heat capacity in relativistic ion collisions  

E-Print Network (OSTI)

The $\\Delta$-scaling method has been applied to the total multiplicity distribution of the relativistic ion collisions of p+p, C+C and Pb+Pb which were simulated by a Monte Carlo package, LUCIAE 3.0. It is found that the $\\Delta$-scaling parameter decreases with the increasing of the system size. Moreover, the heat capacities of different mesons and baryons have been extracted from the event-by-event temperature fluctuation in the region of low transverse mass and they show the dropping trend with the increasing of impact parameter.

Y. G. Ma; G. L. Ma; X. Z. Cai; J. G. Chen; J. H. Chen; D. Q. Fang; W. Guo; Z. J. He; H. Z. Huang; J. L. Long; C. W. Ma; B. H. Sa; W. Q. Shen; Q. M. Su; K. Wang; Y. B. Wei; T. Z. Yan; C. Zhong; J. X. Zuo

2004-11-28T23:59:59.000Z

99

YEAR-END REPORT: HEAVY ION FUSION PROGRAM  

E-Print Network (OSTI)

1978-Mar. 1979, Heavy Ion Fusion Program, Lawrence BerkeleyOlson, Proceedings of the Heavy Ion Fusion Workshop, ArgonneUniversity Ravi N. Sudan KMS Fusion, Inc. Stanford Linear

Fusion Staff, Heavy Ion

2010-01-01T23:59:59.000Z

100

INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMS  

E-Print Network (OSTI)

HIFAN 1830 INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMSAC02-05CH11231. INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION467 (1992). [38] R. W. Moir, Fusion Tech. 25, 5 (1994) [39

Sharp, W. M.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

The high current transport experiment for heavy ion inertial fusion  

E-Print Network (OSTI)

on Heavy Ion Inertial Fusion, Princeton, 1996, edited by J.Conference on Inertial Fusion Sciences and Applications (FOR HEAVY ION INERTIAL FUSION 1 L. R. Prost, D. Baca, F. M.

2004-01-01T23:59:59.000Z

102

The Modular Point Design for Heavy Ion Fusion  

E-Print Network (OSTI)

POINT DESIGN FOR HEAVY ION FUSION S.S. Yu 1 , J.J. BarnardUpdated Point Design for Heavy Ion Fusion, Proc. 2002 Amer.Nucl. Soc. Fusion Topical Meeting, 17-21 November 2002,

2004-01-01T23:59:59.000Z

103

High-energy accelerator for beams of heavy ions  

DOE Patents (OSTI)

An apparatus for accelerating heavy ions to high energies and directing the accelerated ions at a target comprises a source of singly ionized heavy ions of an element or compound of greater than 100 atomic mass units, means for accelerating the heavy ions, a storage ring for accumulating the accelerated heavy ions and switching means for switching the heavy ions from the storage ring to strike a target substantially simultaneously from a plurality of directions. In a particular embodiment the heavy ion that is accelerated is singly ionized hydrogen iodide. After acceleration, if the beam is of molecular ions, the ions are dissociated to leave an accelerated singly ionized atomic ion in a beam. Extraction of the beam may be accomplished by stripping all the electrons from the atomic ion to switch the beam from the storage ring by bending it in magnetic field of the storage ring.

Martin, Ronald L. (La Grange, IL); Arnold, Richard C. (Chicago, IL)

1978-01-01T23:59:59.000Z

104

Multiple Electron Stripping of Heavy Ion Beams  

DOE Green Energy (OSTI)

One approach being explored as a route to practical fusion energy uses heavy ion beams focused on an indirect drive target. Such beams will lose electrons while passing through background gas in the target chamber, and therefore it is necessary to assess the rate at which the charge state of the incident beam evolves on the way to the target. Accelerators designed primarily for nuclear physics or high energy physics experiments utilize ion sources that generate highly stripped ions in order to achieve high energies economically. As a result, accelerators capable of producing heavy ion beams of 10 to 40 Mev/amu with charge state 1 currently do not exist. Hence, the stripping cross-sections used to model the performance of heavy ion fusion driver beams have, up to now, been based upon theoretical calculations. We have investigated experimentally the stripping of 3.4 Mev/amu Kr 7+ and Xe +11 in N2; 10.2 MeV/amu Ar +6 in He, N2, Ar and Xe; 19 MeV/amu Ar +8 in He, N2, Ar and Xe; 30 MeV He 1 + in He, N2, Ar and Xe; and 38 MeV/amu N +6 in He, N2, Ar and Xe. The results of these measurements are compared with the theoretical calculations to assess their applicability over a wide range of parameters.

D. Mueller; L. Grisham; I. Kaganovich; R. L. Watson; V. Horvat; K. E. Zaharakis; Y. Peng

2002-06-25T23:59:59.000Z

105

Medium energy heavy ion operations at RHIC  

Science Conference Proceedings (OSTI)

As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

2011-03-28T23:59:59.000Z

106

Diamond Detectors for Heavy Ion Measurements  

E-Print Network (OSTI)

In 1999, the accelerator facility at GSI is scheduled to deliver beam intensities of about 10 10 particles/spill for all available ions up to 238 U. This necessitates the development of a new generation of radiation-resistant and ultra-fast detectors, in conjunction with new high-speed and low-noise electronics. Preliminary results confirm the suitability of CVD-diamond detectors for both, beam diagnostics, and heavy-ion experiments with projectiles in the energy region from 50 MeV/amu to 2 GeV/amu. Various test measurements

E. Berdermann; K. Blasche; P. Moritz; H. Stelzer; F. Zeytouni

1998-01-01T23:59:59.000Z

107

A Radiographic Technique With Heavy Ion Microbeams  

SciTech Connect

In this work, we introduce a new technique to perform densitometric and multielemental analysis of samples at the same time using a simple detector with heavy ion micro-beams. It consists in the simultaneous analysis of X-rays induced in the sample and in a secondary target arranged behind the specimen. The X-rays originated in the secondary target are attenuated when crossing the specimen producing a radiographic image with a monochromatic source.

Muscio, J. [ECyT, UNSAM, 1650 San Martin, Buenos Aires (Argentina); Somacal, H.; Burlon, A. A.; Debray, M. E.; Valda, A. A. [ECyT, UNSAM, 1650 San Martin, Buenos Aires (Argentina); U.A. Fisica, Laboratorio TANDAR, CNEA, 1650 San Martin, Buenos Aires (Argentina); Kreiner, A. J. [U.A. Fisica, Laboratorio TANDAR, CNEA, 1650 San Martin, Buenos Aires (Argentina); ECyT, UNSAM, 1650 San Martin, Buenos Aires (Argentina); CONICET (Argentina); Kesque, J. M.; Minsky, D. M. [U.A. Fisica, Laboratorio TANDAR, CNEA, 1650 San Martin, Buenos Aires (Argentina)

2007-02-12T23:59:59.000Z

108

Heavy Ion Fusion Systems Assessment study  

SciTech Connect

The Heavy Ion Fusion Systems Assessment (HIFSA) study was conducted with the specific objective of evaluating the prospects of using induction linac drivers to generate economical electrical power from inertial confinement fusion. The study used algorithmic models of representative components of a fusion system to identify favored areas in the multidimensional parameter space. The resulting cost-of-electricity (COE) projections are comparable to those from other (magnetic) fusion scenarios, at a plant size of 100 MWe.

Dudziak, D.J.; Herrmannsfeldt, W.B.

1986-07-01T23:59:59.000Z

109

Dynamics of neutralizing electrons during the focusing of intense heavy ions beams inside a heavy fusion reactor chamber  

E-Print Network (OSTI)

beams inside a heavy ion fusion reactor chamber * Agustin F.of a Heavy Ion Fusion reactor heavily depends on the maximum

Lifschitz, Agustin F.; Maynard, Gilles; Vay, Jean-Luc; Lenglet, Andrian

2006-01-01T23:59:59.000Z

110

Dynamics of neutralizing electrons during the focusing of intense heavy ions beams inside a heavy fusion reactor chamber  

E-Print Network (OSTI)

beams inside a heavy ion fusion reactor chamber * Agustin F.efficiency of a Heavy Ion Fusion reactor heavily depends on

Lifschitz, Agustin F.; Maynard, Gilles; Vay, Jean-Luc; Lenglet, Andrian

2006-01-01T23:59:59.000Z

111

Planar and nonplanar ion acoustic shock waves in relativistic degenerate astrophysical electron-positron-ion plasmas  

SciTech Connect

We have studied the propagation of ion acoustic shock waves involving planar and non-planar geometries in an unmagnetized plasma, whose constituents are non-degenerate ultra-cold ions, relativistically degenerate electrons, and positrons. By using the reductive perturbation technique, Korteweg-deVries Burger and modified Korteweg-deVries Burger equations are derived. It is shown that only compressive shock waves can propagate in such a plasma system. The effects of geometry, the ion kinematic viscosity, and the positron concentration are examined on the ion acoustic shock potential and electric field profiles. It is found that the properties of ion acoustic shock waves in a non-planar geometry significantly differ from those in planar geometry. The present study has relevance to the dense plasmas, produced in laboratory (e.g., super-intense laser-dense matter experiments) and in dense astrophysical objects.

Ata-ur-Rahman,; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Centre for Physics, QAU Campus, Shahdrah Valley Road, Islamabad 44000 (Pakistan); Ali, S. [National Centre for Physics, QAU Campus, Shahdrah Valley Road, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Physics Department, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

2013-04-15T23:59:59.000Z

112

Using Microwave Radiation for Removing Heavy Metal Ions and ...  

Science Conference Proceedings (OSTI)

Presentation Title, Using Microwave Radiation for Removing Heavy Metal Ions and Producing Biofuels. Author(s), Aharon Gedanken. On-Site Speaker (Planned )...

113

Ion-acoustic solitary waves in ultra-relativistic degenerate pair-ion plasmas  

SciTech Connect

The arbitrary and the small amplitude ion-acoustic solitary waves (IASWs) have been studied. The former is studied by using the Sagdeev pseudo-potential approach in a plasma consisting of the degenerate ultrarelativistic electrons, positrons, and the non-relativistic classical ions. It is seen that only compressive solitary waves can propagate through such plasmas. The numerical calculations show that the region of existence of the ion-acoustic solitary waves depends upon the positron (ion) number density and the plasma thermal temperature. This study is appropriate for applications in inertial confinement fusion laboratory research as well as the study of astrophysical dense objects such as white dwarf and dense neutron stars.

Rasheed, A.; Tsintsadze, N. L. [Department of Physics, G.C. University, Lahore 54000 (Pakistan); Salam Chair in Physics, G.C. University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, G.C. University, Lahore 54000 (Pakistan)

2011-11-15T23:59:59.000Z

114

The Heavy Ion Fusion Science Virtual National Laboratory Status of heavy-ion-beam-driven  

E-Print Network (OSTI)

and fusion Ranges given in table reflect options under study Table 4.1, page 43 of an HIF White Paper.E. Coleman et al., in Proc. of the 2007 Particle Accelerator Conf., Albuquerque, NM, 2007(IEEE catalog# 07CH-see http://videos.komando.com/2008/08/19/water-painting/]. #12;12/7/08 The Heavy Ion Fusion Science Virtual

115

Triangular flow in heavy ion collisions in a multiphase transport model  

E-Print Network (OSTI)

We obtain a new set of parameters in a multiphase transport (AMPT) model that are able to describe both the charged particle multiplicity density and the elliptic flow measured in Au + Au collisions at center-of-mass energy root(S)NN = 200 GeV at the Relativistic Heavy Ion Collider, although they still give somewhat softer transverse momentum spectra. We then use the model to predict the triangular flow due to fluctuations in the initial collision geometry and study its effect relative to those from other harmonic components of anisotropic flows on the dihadron azimuthal correlations in both central and midcentral collisions.

Xu, Jun; Ko, Che Ming.

2011-01-01T23:59:59.000Z

116

Develpoment of a one-meter plasma source for heavy ion beam charge neutralization  

E-Print Network (OSTI)

Heavy Ion Beam Driven Fusion Reactor Study, KfK-3480,is a possible heavy ion fusion reactor design [1]. The final

2005-01-01T23:59:59.000Z

117

Report of the Ad Hoc Panel on heavy ion facilities  

SciTech Connect

In response to a request from the USAEC, the President of the National Academy of Sciences appointed an Ad Hoc Panel under the NAS-NRC Committee on Nuclear Science to make an intensive study of various aspects of the science and technology involved in heavy ion research in light of the needs of the national program in this field. In particular, the panel was asked to formulate and evaluate various options for the development of heavy ion facilities that would include an appropriate accelerator complex capable of producing heavy ion beams and the ancillary apparatus required for experimental exploitation. Also, the Panel was asked to evaluate the current status and potentialities of the Super HILAC and Bevalac accelerators of the Lawrence Radiation Laboratory, Berkeley. Results of the study are presented. Topics include heavy ions in nuclear physics and chemistry, atomic physics, heavy ions and astro and space physics, materials science and solid state, and biomedicine. The state of the technology related to the choice of a heavy ion accelerator system is reviewed, and the various possible choices are reviewed including the large tandem accelerator, tandem- cyclotron systems, and linear accelerators. The upgrading of existing facilities (Super HILAC, Bevalac, and PPA) is discussed. Cost estimates for various heavy ion facilities are briefly discussed. (WHK)

1974-01-01T23:59:59.000Z

118

Sandia National Labs: PCNSC: Heavy Ion Backscattering Spectrometry  

NLE Websites -- All DOE Office Websites (Extended Search)

Heavy Ion Backscattering Spectrometry (HIBS) Heavy Ion Backscattering Spectrometry (HIBS) IBA Table (HTML) | IBA Table (135KB GIF) | IBA Table (1.2MB PDF) | IBA Table (33MB TIF) | Heavy Ion Backscattering Spectrometry (HIBS) | Virtual Lab Tour (6MB) Description of Technique: HIBS is used to detect ultra-trace levels of heavy impurities on the surface of a Si wafer. HIBS has advantages over TXRF, including: Improved sensitivity for most elements Quantifying composition without standards Measurement on rough surfaces. HIBS is accomplished by focusing a 120 keV beam of C+ions onto a small spot at the wafer's surface. The backscattered ions are collected by a time-of-flight (TOF) detector array with a large solid angle. The flight time of the backscattered C identifies the near-surface impurities and the

119

The Relativistic Heavy Ion Collider (RHIC) - the nation's only remaining  

NLE Websites -- All DOE Office Websites (Extended Search)

Collider (RHIC) - the nation's only remaining Collider (RHIC) - the nation's only remaining particle collider, located at Brookhaven National Laboratory - has made a series of landmark discoveries and continuing breakthroughs in science and technology. One major accomplishment has been RHIC's ability to recreate and study in detail a type of matter that last existed at the beginning of the universe to better understand the strongest force in nature - the force that holds together the fundamental particles that make up 99 percent of visible matter in the universe today, everything from stars to planets to people. In addition to giving us a new way to explore and understand the nature of the early universe and the force that holds together ordinary matter, research at RHIC has revealed stunning

120

Proton Polarimetry at the Relativistic Heavy Ion Collider  

DOE Green Energy (OSTI)

The RHIC polarized proton collider employs polarimeters in each of the Blue and Yellow rings that utilize the analyzing power in p-Carbon elastic scattering in the Coulomb Nuclear Interference region to measure the absolute beam polarization. These are calibrated by the polarized Hydrogen Jet Target that measures the absolute beam polarization in pp elastic scattering in the CNI region. This paper describes the status and performance of these polarimeters in the FY09 run which included both a 250 GeV/c and 100 GeV/c physics data taking periods. We will describe some of the difficulties encountered and the efforts underway to improve the performance in better energy resolution, rate handling capability, and reduced systematic uncertainties.

Makdisi, Y.; Aschenauer, E.; Atoian, G.; Bazilevsky, A.; Bunce, G.; Gill, R.; Huang, H.; Morozov, B.; Rescia, S.; Sivertz, M.; Yip, K.; Zelenski, A.; Lee, S.K.; Li, X.; Alekseev, I.; Svirida, D.

2009-09-07T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Hydro-kinetic approach to relativistic heavy ion collisions  

E-Print Network (OSTI)

We develop a combined hydro-kinetic approach which incorporates hydrodynamical expansion of the systems formed in \\textit{A}+\\textit{A} collisions and their dynamical decoupling described by escape probabilities. The method corresponds to a generalized relaxation time ($\\tau_{\\text{rel}}$) approximation for Boltzmann equation applied to inhomogeneous expanding systems; at small $\\tau_{\\text{rel}}$ it also allows one to catch the viscous effects in hadronic component - hadron-resonance gas. We demonstrate how the approximation of sudden freeze-out can be obtained within this dynamical picture of continuous emission and find that hypersurfaces, corresponding to sharp freeze-out limit, are momentum dependent. The pion $m_{T}$ spectra are computed in the developed hydro-kinetic model, and compared with those obtained from ideal hydrodynamics with the Cooper-Frye isothermal prescription. Our results indicate that there does not exist a universal freeze-out temperature for pions with different momenta, and support ...

Akkelin, S V; Karpenko, Iu A; Sinyukov, Yu M

2008-01-01T23:59:59.000Z

122

Heavy Ion Physics at the ATLAS Detector  

E-Print Network (OSTI)

The ATLAS detector is one of the two large detectors built to carry on high pT physics at the Large Hadron Collider. The detector is designed to perform optimally at the challenging nominal LHC machine luminosity of 10^34 cm-2s-1. ATLAS has a finely segmented electromagnetic and hadronic calorimeters covering 10 units of rapidity. The inner tracking system is composed of sicilicon pixel detector, silicon central tracker, transition radiation tracker and a 2T solenoidal magnet, covering 5 units of rapidity. The muon spectrometer is located outside the calorimeter volume. Muon chambers and air core toroids are used to track muons of momentum larger than 4 GeV. The ATLAS detector has a superb performance for jet physics because of its calorimeters. Simulation studies also indicate that it will be possible to tag b-jets in the heavy ion environment. Upsilon and J/Psi can be reconstructed through the di-muon decay channel. The detector is ideal for the study of global variables, namely total energy flow and ...

Takai, H; The ATLAS collaboration

2009-01-01T23:59:59.000Z

123

Inertially confined fusion using heavy ion drivers  

Science Conference Proceedings (OSTI)

The various technical issues of HIF will be briefly reviewed in this paper. It will be seen that there are numerous areas in common in all the approaches to HIF. In the recent International Symposium on Heavy Ion Inertial Fusion, the attendees met in specialized workshop sessions to consider the needs for research in each area. Each of the workshop groups considered the key questions of this report: (1) Is this an appropriate time for international collaboration in HIF (2) Which problems are most appropriate for such collaboration (3) Can the sharing of target design information be set aside until other driver and systems issues are better resolved, by which time it might be supposed that there could be a relaxation of classification of target issues (4) What form(s) of collaboration are most appropriate, e.g., bilateral or multilateral (5) Can international collaboration be sensibly attempted without significant increases in funding for HIF The authors of this report share the conviction that collaboration on a broad scale is mandatory for HIF to have the resources, both financial and personnel, to progress to a demonstration experiment. Ultimately it may be possible for a single driver with the energy, power, focusibility, and pulse shape to satisfy the needs of the international community for target physics research. Such a facility could service multiple experimental chambers with a variety of beam geometries and target concepts.

Herrmannsfeldt, W.B. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Bangerter, R.O. (Lawrence Berkeley Lab., CA (United States)); Bock, R. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)); Hogan, W.J.; Lindl, J.D. (Lawrence Livermore National Lab., CA (United States))

1991-10-01T23:59:59.000Z

124

Inertially confined fusion using heavy ion drivers  

Science Conference Proceedings (OSTI)

The various technical issues of HIF will be briefly reviewed in this paper. It will be seen that there are numerous areas in common in all the approaches to HIF. In the recent International Symposium on Heavy Ion Inertial Fusion, the attendees met in specialized workshop sessions to consider the needs for research in each area. Each of the workshop groups considered the key questions of this report: (1) Is this an appropriate time for international collaboration in HIF? (2) Which problems are most appropriate for such collaboration? (3) Can the sharing of target design information be set aside until other driver and systems issues are better resolved, by which time it might be supposed that there could be a relaxation of classification of target issues? (4) What form(s) of collaboration are most appropriate, e.g., bilateral or multilateral? (5) Can international collaboration be sensibly attempted without significant increases in funding for HIF? The authors of this report share the conviction that collaboration on a broad scale is mandatory for HIF to have the resources, both financial and personnel, to progress to a demonstration experiment. Ultimately it may be possible for a single driver with the energy, power, focusibility, and pulse shape to satisfy the needs of the international community for target physics research. Such a facility could service multiple experimental chambers with a variety of beam geometries and target concepts.

Herrmannsfeldt, W.B. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Bangerter, R.O. [Lawrence Berkeley Lab., CA (United States); Bock, R. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Hogan, W.J.; Lindl, J.D. [Lawrence Livermore National Lab., CA (United States)

1991-10-01T23:59:59.000Z

125

Experimental Evaluation of a Negative Ion Source for a Heavy Ion Fusion Negative Ion Driver  

DOE Green Energy (OSTI)

Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photo-detached to neutrals. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm{sup 2} was obtained under the same conditions that gave 57 45 mA/cm{sup 2} of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that i s used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl{sup -} was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 45 mA/cm{sup 2}, sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source.

L.R. Grisham, S.K. Hahto, S.T. Hahto, J.W. Kwan, and K.N. Leung

2004-06-16T23:59:59.000Z

126

Measurements of phi meson production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC)  

E-Print Network (OSTI)

We present results for the measurement of ? meson production via its charged kaon decay channel ??K[superscript +]K[superscript -] in Au+Au collisions at ?(s[subscript NN])=62.4,130, and 200 GeV, and in p+p and d+Au ...

Sakuma, Tai

127

The Heavy Ion Fusion Science Virtual National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Slide 1 The Heavy Ion Fusion Science Virtual National Laboratory Python in a Parallel Environment Dave Grote - LLNL & LBNL NUG2013 User Day Wednesday, February 15, 2013 Slide 2 The...

128

Heavy-ion Accelerators for Testing Microelectronic Components at LBNL |  

Office of Science (SC) Website

Heavy-ion Accelerators for Testing Heavy-ion Accelerators for Testing Microelectronic Components at LBNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Heavy-ion Accelerators for Testing Microelectronic Components at LBNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Use of heavy-ion accelerators for testing microelectronic components for

129

$\\Delta$-scaling and heat capacity in relativistic ion collisions  

E-Print Network (OSTI)

The $\\Delta$-scaling method and the multiplicity information entropy has been applied to the relativistic collisions of p+p, C+C and Pb+Pb which were simulated by a Monte Carlo package, LUCIAE 3.0. In addition, the heat capacities of different mesons and baryons have been extracted from event-by-event temperature fluctuation.

Ma, Y G; Cai, X Z; Chen, J G; Chen, J H; Fang, D Q; Guo, W; He, Z J; Huang, H Z; Long, J L; Ma, C W; S Ben-Hao; Shen, W Q; Su, Q M; Wang, K; Wei, Y B; Yan, T Z; Zhong, C; Zuo, J X

2005-01-01T23:59:59.000Z

130

Relativistic diffusion  

E-Print Network (OSTI)

We discuss a relativistic diffusion in the proper time in an approach of Schay and Dudley. We derive (Langevin) stochastic differential equations in various coordinates.We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form.We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution.We discuss drag terms leading to an equilibrium distribution.The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Juettner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

Z. Haba

2008-09-08T23:59:59.000Z

131

A new luminescence beam profile monitor for intense proton and heavy ion beams  

DOE Green Energy (OSTI)

A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.

Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T.; Thieberger, P.; Trbojevic, D.; Zelenski, A.

2008-10-01T23:59:59.000Z

132

NUCLEAR STRUCTURE AND HEAVY-ION FUSION  

E-Print Network (OSTI)

Nuclear Structure and Heavy-Ton Fusion* A series of lecturesthe cross section for fusion in the experiments consideredEffects g in III. Subharrier Fusion Cross Sections for Light

Stokstad, R.G.

2010-01-01T23:59:59.000Z

133

RECENT PROGRESS IN HEAVY ION SOURCES  

E-Print Network (OSTI)

improved Bevalac Fusion reactors Vi Q) U .c. Laser, expl.into thermonuclear fusion reactors. A summary of ion sources

Clark, D.J.

2010-01-01T23:59:59.000Z

134

Dirac Equation and Quantum Relativistic Effects in a Single Trapped Ion  

Science Conference Proceedings (OSTI)

We present a method of simulating the Dirac equation in 3+1 dimensions for a free spin-1/2 particle in a single trapped ion. The Dirac bispinor is represented by four ionic internal states, and position and momentum of the Dirac particle are associated with the respective ionic variables. We show also how to simulate the simplified 1+1 case, requiring the manipulation of only two internal levels and one motional degree of freedom. Moreover, we study relevant quantum-relativistic effects, like the Zitterbewegung and Klein's paradox, the transition from massless to massive fermions, and the relativistic and nonrelativistic limits, via the tuning of controllable experimental parameters.

Lamata, L.; Leon, J. [Instituto de Matematicas y Fisica Fundamental, CSIC, Serrano 113-bis, 28006 Madrid (Spain); Schaetz, T. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Solano, E. [Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado Postal 1761, Lima (Peru)

2007-06-22T23:59:59.000Z

135

Direct Photons in Heavy-Ion Collisions  

E-Print Network (OSTI)

A brief overview of direct-photon measurements in ultra-relativistic nucleus-nucleus collisions is given. The results for Pb+Pb collisions at sqrt{s_NN} = 17.3 GeV and for Au+Au collisions at sqrt{s_NN} = 200 GeV are compared to estimates of the direct-photon yield from hard scattering. Both results leave room for a significant thermal photon component. A description purely based on hard scattering processes, however, is not ruled out so far.

Klaus Reygers

2006-11-06T23:59:59.000Z

136

Molecular dynamics simulations of ion range profiles for heavy ions in light targets  

SciTech Connect

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ionsolid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Lan, C.; Xue, J. M.; Zhang, Y.; Morris, J. R.; Zhu, Zh.; Gao, Yanfei; Wang, Y. G.; Yan, S.; Weber, William

2012-01-01T23:59:59.000Z

137

Molecular dynamics simulations of ion range profiles for heavy ions in light targets  

SciTech Connect

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (< {approx} 25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Lan, Chune [Peking University; Xue, Jianming [Peking University; Zhang, Yanwen [ORNL; Morris, James R [ORNL; Zhu, Zihua [Pacific Northwest National Laboratory (PNNL); Gao, Yuan [Peking University; Wang, Yugang [Peking University; Yan, Sha [Peking University; Weber, William J [ORNL

2012-01-01T23:59:59.000Z

138

Molecular dynamics simulations of ion range profiles for heavy ions in light targets  

SciTech Connect

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (<25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Lan, Chune; Xue, Jianming; Zhang, Yanwen; Morris, James R.; Zhu, Zihua; Gao, Yuan; Wang, Yugang; Yan, Sha; Weber, William J.

2012-09-01T23:59:59.000Z

139

THE DEVELOPMENT OF HEAVY-ION ACCELERATORS AS DRIVERS FOR INERTIALLY CONFINED FUSION  

E-Print Network (OSTI)

29 The Fission-fusion Hybrid - iii - General DiscussionInteraction in Heavy Ion Fusion BIBLIOGRAPHY HEAVY IONReactor Designs . . . 27 Pure Fusion Power Reactor Tritium

Herrmannsfeldt, W.b.

2010-01-01T23:59:59.000Z

140

Inertial Fusion Driven by Intense Heavy-Ion Beams  

NLE Websites -- All DOE Office Websites (Extended Search)

INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMS INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMS * W. M. Sharp # , A. Friedman, D. P. Grote, J. J. Barnard, R. H. Cohen, M. A. Dorf, S. M. Lund, L. J. Perkins, M. R. Terry, LLNL, Livermore, CA, USA B. G. Logan, F. M. Bieniosek, A. Faltens, E. Henestroza, J.-Y. Jung, J. W. Kwan, E. P. Lee, S. M. Lidia, P. A. Ni, L. L. Reginato, P. K. Roy, P. A. Seidl, J. H. Takakuwa, J.-L. Vay, W. L. Waldron, LBNL, Berkeley, CA, USA R. C. Davidson, E. P. Gilson, I. D. Kaganovich, H. Qin, E. Startsev, PPPL, Princeton, NJ, USA I. Haber, R. A. Kishek, University of Maryland, College Park, MD, USA A. E. Koniges, NERSC, Berkeley, CA, USA Abstract Intense heavy-ion beams have long been considered a promising driver option for inertial-fusion energy production. This paper briefly compares inertial

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88)  

SciTech Connect

The interpretation of relativistic heavy-ion collisions at RHIC energies with thermal concepts is largely based on the relative success of ideal (nondissipative) hydrodynamics. This approach can describe basic observables at RHIC, such as particle spectra and momentum anisotropies, fairly well. On the other hand, recent theoretical efforts indicate that dissipation can play a significant role. Ideally viscous hydrodynamic simulations would extract, if not only the equation of state, but also transport coefficients from RHIC data. There has been a lot of progress with solving relativistic viscous hydrodynamics. There are already large uncertainties in ideal hydrodynamics calculations, e.g., uncertainties associated with initial conditions, freezeout, and the simplified equations of state typically utilized. One of the most sensitive observables to the equation of state is the baryon momentum anisotropy, which is also affected by freezeout assumptions. Up-to-date results from lattice quantum chromodynamics on the transition temperature and equation of state with realistic quark masses are currently available. However, these have not yet been incorporated into the hydrodynamic calculations. Therefore, the RBRC workshop 'Hydrodynamics in Heavy Ion Collisions and QCD Equation of State' aimed at getting a better understanding of the theoretical frameworks for dissipation and near-equilibrium dynamics in heavy-ion collisions. The topics discussed during the workshop included techniques to solve the dynamical equations and examine the role of initial conditions and decoupling, as well as the role of the equation of state and transport coefficients in current simulations.

Karsch,F.; Kharzeev, D.; Molnar, K.; Petreczky, P.; Teaney, D.

2008-04-21T23:59:59.000Z

142

Heavy ion radiation damage simulations for CMOS image sensors Henok Mebrahtua  

E-Print Network (OSTI)

Heavy ion radiation damage simulations for CMOS image sensors Henok Mebrahtua , Wei Gaoa , Paul J, University of Toronto, Toronto, Ontario, Canada ABSTRACT Damage in CMOS image sensors caused by heavy ions and range of ions in matter) simulation results of heavy ion radiation damage to CMOS image sensors

Hornsey, Richard

143

QCD plasma instability and thermalisation at heavy ion collisions  

E-Print Network (OSTI)

Under suitable non-equilibrium conditions QCD plasma can develop plasma instabilities, where some modes of the plasma grow exponentially. It has been argued that these instabilities can play a significant role in the thermalisation of the plasma in heavy-ion collision experiments. We study the instability in SU(2) plasmas using the hard thermal loop effective lattice theory, which is suitable for studying real-time evolution of long wavelength modes in the plasma. We observe that under suitable conditions the plasma can indeed develop an instability which can grow to a very large magnitude, necessary for the rapid thermalisation in heavy-ion collisions.

Dietrich Bodeker; Kari Rummukainen

2007-11-13T23:59:59.000Z

144

Heating of heavy ions on auroral field lines  

DOE Green Energy (OSTI)

Heating of heavy ions is studied in the presence of large amplitude hydrogen cyclotron waves. A three wave decay process, in which a large amplitude pump hydrogen cyclotron wave decays into a daughter hydrogen cyclotron wave and a low frequency oxygen cyclotron wave, is studied theoretically and by numerical simulations. The numerical simulations show a decay instability resulting in strong heating of both the oxygen ions and the hydrogen ions. In particular, the high energy tail of the oxygen ions is observed in the perpendicular distribution.

Nishikawa, K.I.; Okuda, H., Hasegawa, A.

1983-01-01T23:59:59.000Z

145

EBIS as an injector for heavy-ion linacs  

SciTech Connect

The Electron Beam Ion Source (EBIS), because of its high-charge states and pulsed operation, is ideally suited as an injector for a heavy-ion linac operating at a low duty factor. Although presently in use with conventional linacs, the low emittance and the large yield of highly charged ions in each pulse make the EBIS even more interesting as an injector for the new linac accelerating structures such as the alternating-phase-focusing (APF) structure or the radio-frequency quadrupole (RFQ) structure. These new structures could be used with an EBIS to produce a small, efficient, low-duty-cycle accelerator. Coupled to a conventional linac, the resulting accelerator could be used for heavy-ion medical therapy or nuclear physics, or it could be used as an injector for a synchrotron or storage ring.

Hamm, R.W.

1979-01-01T23:59:59.000Z

146

Fragmentation of very high energy heavy ions  

E-Print Network (OSTI)

A stack of CR39 (C12H18O7)n nuclear track detectors with a Cu target was exposed to a 158 A GeV lead ion beam at the CERN-SPS, in order to study the fragmentation properties of lead nuclei. Measurements of the total, break-up and pick-up charge-changing cross sections of ultrarelativistic Pb ions on Cu and CR39 targets are presented and discussed.

Giorgini, M

2001-01-01T23:59:59.000Z

147

Direct photons ~basis for characterizing heavy ion collisions~  

E-Print Network (OSTI)

After years of experimental and theoretical efforts, direct photons become a strong and reliable tool to establish the basic characteristics of a hot and dense matter produced in heavy ion collisions. The recent direct photon measurements are reviewed and a future prospect is given.

Takao Sakaguchi

2008-05-30T23:59:59.000Z

148

Chemical Equilibrium in Heavy Ion Collisions: Rapidity Dependence  

E-Print Network (OSTI)

Particle yields in heavy ion collisions show an overwhelming evidence for chemical or relative chemical equilibrium at all beam energies. The rapidity dependence of the thermal parameters $T$ and $\\mu_B$ can now be determined over a wide range of rapidities and show a systematic behavior towards an increase in $\\mu_B$ away from mid-rapidity.

F. Becattini; J. Cleymans

2007-01-04T23:59:59.000Z

149

Spatially resolved instability measurements with a heavy ion beam probe  

SciTech Connect

A heavy ion beam probe was used to make simultaneous measurements of the amplitude and phase of both density and space potential fluctuations in an energetic arc plasma. Detailed comparison with theoretical predictions identifies a 70 KHz coherent oscillation as a Kelvin-Helmholtz instability localized to a region of strong fluid shear. (auth)

Jennings, W. C.; Hickok, R. L.; Glowienka, J. C.

1975-01-01T23:59:59.000Z

150

Jozso's Legacy Chemical and Kinetic Freeze-out in Heavy-Ion Collisions  

E-Print Network (OSTI)

We review J. Zimanyi's key contributions to the theoretical understanding of dynamical freeze-out in nuclear collisions and their subsequent applications to ultra-relativistic heavy-ion collisions, leading to the discovery of a freeze-out hierarchy where chemical freeze-out of hadron yields precedes the thermal decoupling of their momentum spectra. Following Zimanyi's lines of reasoning we show that kinetic freeze-out necessarily leads to a dependence of the corresponding freeze-out temperature on collision centrality. This centrality dependence can be predicted within hydrodynamic models, and for Au+Au collisions at RHIC this prediction is shown to reproduce the experimentally observed centrality dependence of the thermal decoupling temperature, extracted from hadron momentum spectra. The fact that no such centrality dependence is observed for the chemical decoupling temperature, extracted from the hadron yields measured in these collisions, excludes a similar kinetic interpretation of the chemical decouplin...

Heinz, U

2008-01-01T23:59:59.000Z

151

Heavy-Ion-Fusion-Science: Summary of U.S. Progress  

E-Print Network (OSTI)

IAEA-06 Topic IF Heavy-Ion-Fusion-Science: Summary of U.S.W.L. Waldron, U.S. Heavy Ion Fusion Science Virtual NationalExperiment at PPPL. [1] Fusion Energy Sciences Advisory

2006-01-01T23:59:59.000Z

152

HEAVY ION FUSION YEAR-END REPORT APRIL 1, 1981 - SEPT. 30, 1981  

E-Print Network (OSTI)

Keefe E. Denis Keefe HEAVY ION FUSION ROSTER Warren W. ChuppOF CALIFORNIA Accelerator & Fusion Research DivisionHEAVY ION FUSION YEAR-END REPORT April 1, 1981 - September

Authors, Various

2010-01-01T23:59:59.000Z

153

LAWRENCE BERKELEY LABORATORY YEAR-END-REPORT ON HEAVY-ION FUSION PROGRAM  

E-Print Network (OSTI)

Beams of a Pellet Fusion Reactor by D. Neuffer, GeometricTarget of a Heavy Ion Fusion Reactor: Summary of a meetingTarget of a Heavy Ion Fusion Reactor: Summary of a Meeting

Staff, HIF

2011-01-01T23:59:59.000Z

154

Workshop on Accelerators for Heavy Ion Fusion Summary Report of the Workshop  

E-Print Network (OSTI)

W. M. Sharp, and D. R. Welch, Fusion Sci. Technol. 44, 266implosion in heavy ion fusion,"Laser Part. Beam 24, 359-Heavy-Ion-Beam Inertial Fusion at High Coupling Efficiency.

Seidl, P.A.

2013-01-01T23:59:59.000Z

155

Means for obtaining a metal ion beam from a heavy-ion cyclotron source  

DOE Patents (OSTI)

A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

Hudson, E.D.; Mallory, M.L.

1975-08-01T23:59:59.000Z

156

ON THE FEASIBILITY OF POLARIZED HEAVY IONS IN RHIC.  

Science Conference Proceedings (OSTI)

Heavy nonspherical ions such as uranium have been proposed for collisions in RHIC[1]. When two such ions collide with their long axes aligned parallel to the beams (large helicities), then the plasma density might be as much as 60% higher. Since the collisions might have any orientation of the two nuclei, the alignment of the nuclei must be inferred from a complicated unfolding of multiplicity distributions. Instead, if it would be possible to polarize the ions and control the orientation in RHIC, then a much better sensitivity might be obtained. This paper investigates the manipulation of such polarized ions with highly distorted shapes in RHIC. A number of ion species are considered as possibilities with either full or partial Siberian snakes in RHIC.

MACKAY, W.W.

2006-06-23T23:59:59.000Z

157

The ECR heavy-ion source for ATLAS  

SciTech Connect

The ATLAS PII-ECR ion source is the first ECR ion source to be designed for operation in a high voltage platform. The source system is required to provide beams of heavy ions with a velocity of 0.01c for subsequent acceleration by the superconducting ATLAS Positive Ion Injector Linac. At present, the ability of the system to provide high charge state ions with velocities up to .01c is probably unique and as such has generated significant interest in the atomic physics community. A beamline for atomic physics has been installed and is now in use. The source began operation in October, 1987. The source capabilities and operating experiences to date will be discussed. 6 refs., 3 figs., 3 tabs.

Pardo, R.C.; Billquist, P.J.

1989-01-01T23:59:59.000Z

158

Light-ion production from intermediate-energy Heavy-Ion interactions  

Science Conference Proceedings (OSTI)

The production of light ions such as protons, neutrons, deuterons, tritons, 3He and 4He from heavy ion interactions still remains as a key issue to be investigated for the purposes of radiation protection in space. Ultimately, we will produce double-differential ...

L. Heilbronn; M. Beach; L. Townsend

2011-03-01T23:59:59.000Z

159

Analytical Proton Transfer Amplitude for Heavy Ion Induced Nuclear Reactions  

Science Conference Proceedings (OSTI)

Direct reactions between heavy ions have been studied widely using semi-classical theories. The Distorted Wave Born Approximation or DWBA has been extensively applied to analyse transfer reaction processes. Initial attempts to gain insights into the simple semi-classical parametrisation starting from the DWBA had focused mainly on neutron transfer reactions. An analytical formula for the semi-classical amplitude for the transfer of a single neutron between bound classical orbits states in heavy ion collisions that agrees well with the DWBA calculations has been successfully derived. In this paper, we have successfully derived the corresponding analytical expression for the proton transfer amplitude by using a technique analogous to the transfer of a single neutron between bound states. Our result reduces to the well known expression for the neutron transfer amplitude in the limit that the nuclear charge tends to zero.

Kumar, P. Rajesh [Open University Malaysia, Jalan Tun Ismail, 50480 Kuala Lumpur (Malaysia); Wong, Bernardine Renaldo [Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

160

Kaon production in heavy ion reactions at intermediate energies  

E-Print Network (OSTI)

The article reviews the physics related to kaon and antikaon production in heavy ion reactions at intermediate energies. Chiral dynamics predicts substantial modifications of the kaon properties in a dense nuclear environment. The status of the theoretical predictions as well as experimental evidences for medium effects such as repulsive/attractive mass shifts for $K^+/K^-$ are reviewed. In the vicinity of the thresholds, and even more pronounced below threshold, the production of strangeness is a highly collective process. Starting from elementary reaction channels the phenomenology of $K^+$ and $K^-$ production, i.e. freeze-out densities, time scales etc. as derived from experiment and theoretical transport calculations is presented. Below threshold kaon production shows a high sensitivity on the nuclear compression reached in heavy ion reactions. This allows to put constraints on the nuclear equation-of-state which are finally discussed.

Christian Fuchs

2005-07-07T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Triggering on hard probes in heavy ion collisions with CMS  

E-Print Network (OSTI)

We present a study of the CMS trigger system in heavy-ion collisions. Concentrating on two physics channels, dimuons from decays of quarkonia and single jets, we evaluate a possible trigger strategy for Pb+Pb running that relies on event selection solely in the High-Level Trigger (HLT). The study is based on measurements of the timing performance of the offline algorithms and event-size distributions using full simulations. Using a trigger simulation chain, we compare the physics reach for the jet and dimuon channels using online selection in the HLT to minimum bias running. The results demonstrate the crucial role the HLT will play for CMS heavy-ion physics.

G. Roland; for the CMS Collaboration

2007-02-21T23:59:59.000Z

162

Heavy-ion accelerator research for inertial fusion  

SciTech Connect

Thermonuclear fusion offers a most attractive long-term solution to the problem of future energy supplies: The fuel is virtually inexhaustible and the fusion reaction is notably free of long-lived radioactive by-products. Also, because the fuel is in the form of a plasma, there is no solid fuel core that could melt down. The DOE supports two major fusion research programs to exploit these virtues, one based on magnetic confinement and a second on inertial confinement. One part of the program aimed at inertial fusion is known as Heavy Ion Fusion Accelerator Research, or HIFAR. In this booklet, the aim is to place this effort in the context of fusion research generally, to review the brief history of heavy-ion fusion, and to describe the current status of the HIFAR program.

1987-08-01T23:59:59.000Z

163

Accelerators for heavy ion inertial fusion: Progress and plans  

SciTech Connect

The Heavy Ion Inertial Fusion Program is the principal part of the Inertial Fusion Energy Program in the Office of Fusion Energy of the U.S. Department of Energy. The emphasis of the Heavy Ion Program is the development of accelerators for fusion power production. Target physics research and some elements of fusion chamber development are supported in the much larger Inertial Confinement Fusion Program, a dual purpose (defense and energy) program in the Defense Programs part of the Department of Energy. The accelerator research program will establish feasibility through a sequence of scaled experiments that will demonstrate key physics and engineering issues at low cost compared to other fusion programs. This paper discusses progress in the accelerator program and outlines how the planned research will address the key economic issues of inertial fusion energy.

Bangerter, R.O.; Friedman, A.; Herrmannsfeldt, W.B.

1994-08-01T23:59:59.000Z

164

The shape of heavy ion upset cross section curves  

Science Conference Proceedings (OSTI)

An approach is developed to describe heavy ion single event upset cross section curves. It accounts for all significant mechanisms which cause the curve to deviate from ideal, step function-like behavior. The method is developed in terms of the charge deposited by an incident ion in a memory cell and is therefore free of ambiguities associated with the effective LET concept. It is suggested that this type of approach is an improvement over current methods used to characterize a memory response to accelerator tests. This has significant implications for predicting space upset rates.

Xapsos, M.A. (Naval Research Lab., Washington, DC (United States). Radiation Effects Branch); Weatherford, T.R.; Shapiro, P. (SFA, Inc., Landover, MD (United States))

1993-12-01T23:59:59.000Z

165

Limiting fragmentation of chemical potentials in heavy ion collisions  

E-Print Network (OSTI)

Thermal models have been used to successfully describe the hadron yields from heavy ion collisions at a variety of energies. For root(S)chemical potentials, muS = 0.21 +-0.01muB. Using this relation we are able to describe the energy dependence of Lambda, Xsi and Omega ratios from other experiments. We also find that the chemical potentials are consistent with limiting fragmentation.

Laura A. Stiles; Michael Murray

2006-01-30T23:59:59.000Z

166

Production of 14 MeV neutrons by heavy ions  

SciTech Connect

This invention relates to a neutron generator and a method for the production of 14 MeV neutrons. Heavy ions are accelerated to impinge upon a target mixture of deuterium and tritium to produce recoil atoms of deuterium and tritium. These recoil atoms have a sufficient energy such that they interact with other atoms of tritium or deuterium in the target mixture to produce approximately 14 MeV neutrons.

Brugger, Robert M. (Columbia, MO); Miller, Lowell G. (Idaho Falls, ID); Young, Robert C. (Idaho Falls, ID)

1977-01-01T23:59:59.000Z

167

Experimental evaluation of a negative ion source for a heavy ionfusion negative ion driver  

DOE Green Energy (OSTI)

Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photodetached to neutrals [1,2,3]. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm{sup 2} was obtained under the same conditions that gave 57 mA/cm{sup 2} of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that is used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl{sup -} was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 mA/cm{sup 2}, sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source.

Grisham, L.R.; Hahto, S.K.; Hahto, S.T.; Kwan, J.W.; Leung, K.N.

2005-01-18T23:59:59.000Z

168

Modeling Chamber Transport for Heavy-Ion Fusion  

DOE Green Energy (OSTI)

In a typical thick-liquid-wall scenario for heavy-ion fusion (HIF), between seventy and two hundred high-current beams enter the target chamber through ports and propagate about three meters to the target. Since molten-salt jets are planned to protect the chamber wall, the beams move through vapor from the jets, and collisions between beam ions and this background gas both strip the ions and ionize the gas molecules. Radiation from the preheated target causes further beam stripping and gas ionization. Due to this stripping, beams for heavy-ion fusion are expected to require substantial neutralization in a target chamber. Much recent research has, therefore, focused on beam neutralization by electron sources that were neglected in earlier simulations, including emission from walls and the target, photoionization by the target radiation, and pre-neutralization by a plasma generated along the beam path. When these effects are included in simulations with practicable beam and chamber parameters, the resulting focal spot is approximately the size required by a distributed radiator target.

Sharp, W M; Niller, D A C; Tabak, M; Yu, S S; Peterson, P F; Welch, D R; Rose, D V; Olson, C L

2002-08-02T23:59:59.000Z

169

Beam Compression in Heavy-Ion Induction Linacs  

SciTech Connect

The Heavy-Ion Fusion Sciences Virtual National Laboratory is pursuing an approach to target heating experiments in the Warm Dense Matter regime, using space-charge-dominated ion beams that are simultaneously longitudinally bunched and transversely focused. Longitudinal beam compression by large factors has been demonstrated in the LBNL Neutralized Drift Compression Experiment (NDCX) experiment with controlled ramps and forced neutralization. The achieved peak beam current and energy can be used in experiments to heat targets and create warm dense matter. Using an injected 30 mA K{sup +} ion beam with initial kinetic energy 0.3 MeV, axial compression leading to {approx}50x current amplification and simultaneous radial focusing to beam radii of a few mm have led to encouraging energy deposition approaching the intensities required for eV-range target heating experiments. We discuss experiments that are under development to reach the necessary higher beam intensities and the associated beam diagnostics.

Seidl, P.A.; Anders, A.; Bieniosek, F.M.; Barnard, J.J.; Calanog, J.; Chen, A.X.; Cohen, R.H.; Coleman, J.E.; Dorf, M.; Gilson, E.P.; Grote, D.P.; Jung, J.Y.; Leitner, M.; Lidia, S.M.; Logan, B.G.; Ni, P.; Roy, P.K.; Van den Bogert, K.; Waldron, W.L.; Welch, D.R.

2009-01-01T23:59:59.000Z

170

System for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high (n,f) reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

Fries, D.P.; Browning, J.F.

1998-07-21T23:59:59.000Z

171

System for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

Fries, David P. (St. Petersburg, FL); Browning, James F. (Palm Harbour, FL)

1998-01-01T23:59:59.000Z

172

Method for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

Fries, David P. (St. Petersburg, FL); Browning, James F. (Palm Harbour, FL)

1999-01-01T23:59:59.000Z

173

Method for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

Fries, D.P.; Browning, J.F.

1999-02-16T23:59:59.000Z

174

Induction Linac Systems Experiments for heavy ion fusion  

Science Conference Proceedings (OSTI)

The Lawrence Berkeley Laboratory and the Lawrence Livermore National Laboratory propose to build at LBL the Induction Linac Systems Experiments (ILSE), the next logical step toward the eventual goal of a heavy ion induction accelerator powerful enough to implode or drive inertial confinement fusion targets. Though much smaller than a driver, ILSE will be at full driver scale in several important parameters. Nearly all accelerator components and beam manipulations required for a driver will be tested. It is expected that ILSE will be built in stages as funds and technical progress allow. The first stage, called Elise will include all of the electrostatic quadrupole focused parts of ILSE.

Herrmannsfeldt, W.B. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Bangerter, R.O. [Lawrence Berkeley Lab., CA (United States). Accelerator and Fusion Research Div.

1994-06-01T23:59:59.000Z

175

System Size and Energy Dependence of Dilepton Production in Heavy-Ion Collisions at SIS Energies  

E-Print Network (OSTI)

We study the dilepton production in heavy-ion collisions at energies of 1-2 AGeV as well as in proton induced pp, pn, pd and p+A reactions from 1 GeV up to 3.5 GeV. For the analysis we employ three different transport models - the microscopic off-shell Hadron-String-Dynamics (HSD) transport approach, the Isospin Quantum Molecular Dynamics (IQMD) approach as well as the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) approach. We confirm the experimentally observed enhancement of the dilepton yield (normalized to the multiplicity of neutral pions $N_{\\pi^0}$) in heavy-ion collisions with respect to that measured in $NN = (pp+pn)/2$ collisions. We identify two contributions to this enhancement: a) the $pN$ bremsstrahlung which scales with the number of collisions and not with the number of participants, i.e. pions; b) the dilepton emission from intermediate $\\Delta$'s which are part of the reaction cycles $\\Delta \\to \\pi N ; \\pi N \\to \\Delta$ and $NN\\to N\\Delta; N\\Delta \\to NN$. With increasing system size more generations of intermediate $\\Delta$'s are created. If such $\\Delta$ decays into a pion, the pion can be reabsorbed, however, if it decays into a dilepton, the dilepton escapes from the system. Thus, experimentally one observes only one pion (from the last produced $\\Delta$) whereas the dilepton yield accumulates the contributions from all $\\Delta$'s of the cycle. We show as well that the Fermi motion enhances the production of pions and dileptons in the same way. Furthermore, employing the off-shell HSD approach, we explore the influence of in-medium effects like the modification of self-energies and spectral functions of the vector mesons due to their interactions with the hadronic environment.

E. L. Bratkovskaya; J. Aichelin; M. Thomere; S. Vogel; M. Bleicher

2013-01-04T23:59:59.000Z

176

Overview of heavy-ion fusion focus on computer simulation aspect  

E-Print Network (OSTI)

Vay Heavy-Ion Fusion Virtual National Laboratory LawrenceBerkeley National Laboratory Computer Engineering Scienceand Lawrence Livermore National Laboratories under Contract

Vay, Jean-Luc

2002-01-01T23:59:59.000Z

177

Progress in Heavy Ion Driven Target Fabrication and Injection (A24727)  

E-Print Network (OSTI)

Physics Research A 544, 34 (2005)15th International Symposium on Heavy Ion Inertial Fusion Princeton New Jersey, US, 2004999609735

Goodin, D.T.

2004-06-16T23:59:59.000Z

178

Fully integrated transport approach to heavy ion reactions with an intermediate hydrodynamic stage  

E-Print Network (OSTI)

We present a coupled Boltzmann and hydrodynamics approach to relativistic heavy ion reactions. This hybrid approach is based on the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport approach with an intermediate hydrodynamical evolution for the hot and dense stage of the collision. Event-by-event fluctuations are directly taken into account via the non-equilibrium initial conditions generated by the initial collisions and string fragmentations in the microscopic UrQMD model. After a (3+1)-dimensional ideal hydrodynamic evolution, the hydrodynamical fields are mapped to hadrons via the Cooper-Frye equation and the subsequent hadronic cascade calculation within UrQMD proceeds to incorporate the important final state effects for a realistic freeze-out. This implementation allows to compare pure microscopic transport calculations with hydrodynamic calculations using exactly the same initial conditions and freeze-out procedure. The effects of the change in the underlying dynamics - ideal fluid dynamics vs. non-equilibrium transport theory - will be explored. The freeze-out and initial state parameter dependences are investigated for different observables. Furthermore, the time evolution of the baryon density and particle yields are discussed. We find that the final pion and proton multiplicities are lower in the hybrid model calculation due to the isentropic hydrodynamic expansion while the yields for strange particles are enhanced due to the local equilibrium in the hydrodynamic evolution. The results of the different calculations for the mean transverse mass excitation function, rapidity and transverse mass spectra for different particle species at three different beam energies are discussed in the context of the available data.

Hannah Petersen; Jan Steinheimer; Gerhard Burau; Marcus Bleicher; Horst Stcker

2008-06-10T23:59:59.000Z

179

SYSTEMATIC STUDIES OF HEAVY ION COLLISIONS TO SEARCH FOR QUARK-GLUON PLASMA  

SciTech Connect

This is the final technical report for DOE Outstanding Junior Investigator (OJI) Award, 'Systematic Studies of Heavy Ion Collisions to Search for Quark-Gluon Plasma', grant DE-FG02-02ER41219, Principal Investigator (PI) Fuqiang Wang. The research under the grant was divided into two phases. The first concentrated on systematic studies of soft hadron production at low transverse momentum (p{sub T}), in particular the production of (anti-)baryon and strangeness in heavy ion collisions at RHIC energies. The second concentrated on measurements of di-hadron and multi-hadron jet-correlations and investigations of medium response to jets. The research was conducted at the Relativistic Heavy-Ion Collider (RHIC) at BNL with the Solenoidal Tracker At RHIC (STAR) experiment. The total grant is $214,000. The grant established a PC farm solely used for this research. The PC farm consists of 8 nodes with a total of 16 CPUs and 3 disk servers of total 2 TB shared storage. The current balance of the grant is $19,985. The positive balance is because an initial purchase of $22,600 for the PC farm came out of the PI's start-up fund due to the lateness of the award. The PC farm is an integral part of the Purdue Physics Department's computer cluster. The grant supported two Ph.D. graduate students. Levente Molnar was supported from July 2002 to December 2003, and worked on soft hadron production. His thesis title is Systematics of Identified Particle Production in pp, d-Au and Au-Au Collisions at RHIC Energies. He graduated in 2006 and now is a Postdoctoral fellow at INFN Sezione di Bari, Italy working on the ALICE experiment at the LHC. Jason Ulery was supported from January 2004 to July 2007. His thesis title is Two- and Three-Particle Jet-Like Correlations. He defended his thesis in October 2007 and is moving to Frankfurt University, Germany to work on the ALICE experiment at the LHC. The research by this grant resulted in 7 journal publications (2 PRL, 1 PLB, 1 PRC, 2 submitted and 1 in preparation), and 14 invited talks and 10 contributed talks at major conferences. These are listed at end of this report.

Fuqiang Wang

2007-11-29T23:59:59.000Z

180

Photon measurements in forward rapidity in heavy-ion collisions  

E-Print Network (OSTI)

Contribution of a preshower photon multiplicity detector to the physics of ultra-relativistic nuclear collisions is reviewed and future possibilities at RHIC and LHC are discussed

Yogendra Pathak Viyogi

2005-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
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181

Physics implications of correlation data from the RHIC and LHC heavy-ion programs  

E-Print Network (OSTI)

Two-dimensional angular correlation data from the STAR experiment at RHIC and from the LHC experiments provide critical information about dynamical processes in relativistic heavy-ion collisions. The principal correlation structures of interest are a broad jet-related peak at small relative azimuth ($\\phi$) extending to large relative pseudorapidity ($\\eta$), the dijet ridge at large relative azimuth, and an independent double ridge on $\\phi$ represented by a quadrupole function. The broad peak at small relative azimuth has been attributed, in large part, to initial-state fluctuations and hydrodynamic flow which produce higher-order harmonics on $\\phi$. That conjecture is challenged in this paper. It is shown that the net effect of additional higher harmonic model elements is to describe small, non-Gaussian (NG) shapes in the broad jet-related peak. The quadrupole correlation, which is also conventionally attributed to hydrodynamic flow, is considered within the Balitsky - Fadin - Kuraev - Lipatov (BFKL) Pomeron framework. Preliminary results using this model for the quadrupole correlation for particle production from 200 GeV $p+p$ collisions are shown to be consistent with recent data from STAR.

R. L. Ray

2013-11-04T23:59:59.000Z

182

Jozso's Legacy: Chemical and Kinetic Freeze-out in Heavy-Ion Collisions  

E-Print Network (OSTI)

We review J. Zimanyi's key contributions to the theoretical understanding of dynamical freeze-out in nuclear collisions and their subsequent applications to ultra-relativistic heavy-ion collisions, leading to the discovery of a freeze-out hierarchy where chemical freeze-out of hadron yields precedes the thermal decoupling of their momentum spectra. Following Zimanyi's lines of reasoning we show that kinetic freeze-out necessarily leads to a dependence of the corresponding freeze-out temperature on collision centrality. This centrality dependence can be predicted within hydrodynamic models, and for Au+Au collisions at RHIC this prediction is shown to reproduce the experimentally observed centrality dependence of the thermal decoupling temperature, extracted from hadron momentum spectra. The fact that no such centrality dependence is observed for the chemical decoupling temperature, extracted from the hadron yields measured in these collisions, excludes a similar kinetic interpretation of the chemical decoupling process. We argue that the chemical decoupling data from Au+Au collisions at RHIC can only be consistently understood if the chemical freeze-out process is driven by a phase transition, and that the measured chemical decoupling temperature therefore measures the critical temperature of the quark-hadron phase transition. We propose additional experiments to further test this interpretation.

Ulrich W. Heinz; Gregory Kestin

2007-09-21T23:59:59.000Z

183

THERMINATOR 2: THERMal heavy IoN generATOR 2  

E-Print Network (OSTI)

We present an extended version of THERMINATOR, a Monte Carlo event generator dedicated to studies of the statistical production of particles in relativistic heavy-ion collisions. The increased functionality of the code contains the following features: The input of any shape of the freeze-out hypersurface and the expansion velocity field, including the 3+1 dimensional profiles, in particular those generated externally with various hydrodynamic codes. The hypersufraces may have variable thermal parameters, which allows for studies departing significantly from the mid-rapidity region, where the baryon chemical potential becomes large. We include a library of standard sets of hypersurfaces and velocity profiles describing the RHIC Au+Au data at sqrt(s_(NN)) = 200 GeV for various centralities, as well as those anticipated for the LHC Pb+Pb collisions at sqrt(s_(NN)) = 5.5 TeV. A separate code, FEMTO-THERMINATOR, is provided to carry out the analysis of femtoscopic correlations which are an important source of info...

Chojnacki, Mikolaj; Florkowski, Wojciech; Broniowski, Wojciech

2012-01-01T23:59:59.000Z

184

The Heavy Ion Fusion Science Virtual National Laboratory Overview of Fusion Program  

E-Print Network (OSTI)

-pg white paper. Join us in a new IFE skunkworks. #12;11/30/2009 The Heavy Ion Fusion Science Virtual.1, from page 43 of the HIF White Paper prepared for the FESAC HEDLP panel. The proposed OFES heavy ion diagnostics (Bieniosek/Barnard talks), as well as adding more acceleration cells to extend accessible WDM

185

Determining the density dependence of the nuclear symmetry energy using heavy-ion reactions  

E-Print Network (OSTI)

We review recent progress in the determination of the subsaturation density behavior of the nuclear symmetry energy from heavy-ion collisions as well as the theoretical progress in probing the high density behavior of the symmetry energy in heavy-ion reactions induced by high energy radioactive beams. We further discuss the implications of these results for the nuclear effective interactions and the neutron skin thickness of heavy nuclei.

Lie-Wen Chen; Che Ming Ko; Bao-An Li; Gao-Chan Yong

2007-11-12T23:59:59.000Z

186

Beam instrumentation for the BNL Heavy Ion Transfer Line  

Science Conference Proceedings (OSTI)

The Heavy Ion Transfer Line (HITL) was constructed to transport beams from the BNL Tandem Van de Graaff (TVDG) to be injected into the AGS. Because the beam line is approximately 2000 feet long and the particle rigidity is so low, 20 beam monitor boxes were placed along the line. The intensity ranges from 1 to 100 nanoAmps for the dc trace beam used for line set-up, to over 100 ..mu..A for the pulsed beam to be injected into the AGS. Profiles are measured using multiwire arrays (HARPS) while Faraday cups and beam transformers monitor the intensity. The electronics stations are operated through 3 Instrumentation Controllers networked to Apollo workstations in the TVDG and AGS control rooms. Details of the detectors and electronics designs and performance will be given.

Witkover, R.L.; Buxton, W.; Castillo, V.; Feigenbaum, I.; Lazos, A.; Li, Z.G.; Smith, G.; Stoehr, R.

1987-01-01T23:59:59.000Z

187

Statistical Model of Heavy-Ion Fusion-Fission Reactions  

E-Print Network (OSTI)

Cross-section and neutron-emission data from heavy-ion fusion-fission reactions are consistent with the fission of fully equilibrated systems with fission lifetime estimates obtained via a Kramers-modified statistical model which takes into account the collective motion of the system about the ground state, the temperature dependence of the location and height of fission transition points, and the orientation degree of freedom. If the standard techniques for calculating fission lifetimes are used, then the calculated excitation-energy dependence of fission lifetimes is incorrect. We see no evidence to suggest that the nuclear viscosity has a temperature dependence. The strong increase in the nuclear viscosity above a temperature of approximately 1.3 MeV deduced by others is an artifact generated by an inadequate fission model.

J. P. Lestone; S. G. McCalla

2008-07-21T23:59:59.000Z

188

Medium effects on charged pion ratio in heavy ion collisions  

E-Print Network (OSTI)

We have recently studied in the delta-resonance--nucleon-hole model the dependence of the pion spectral function in hot dense asymmetric nuclear matter on the charge of the pion due to the pion p-wave interaction in nuclear medium. In a thermal model, this isospin-dependent effect enhances the ratio of negatively charged to positively charged pions in neutron-rich nuclear matter, and the effect is comparable to that due to the uncertainties in the theoretically predicted stiffness of nuclear symmetry energy at high densities. This effect is, however, reversed if we also take into account the s-wave interaction of the pion in nuclear medium as given by chiral perturbation theory, resulting instead in a slightly reduced ratio of negatively charged to positively charged pions. Relevance of our results to the determination of the nuclear symmetry energy from the ratio of negatively to positively charged pions produced in heavy ion collisions is discussed.

Che Ming Ko; Yongseok Oh; Jun Xu

2010-02-01T23:59:59.000Z

189

Nuclear deformation effect on the binding energies in heavy ions  

E-Print Network (OSTI)

Nuclear deformation effects on the binding energies in heavy ions are investigated. Approximate formulas for the nuclear-size correction and the isotope shift for deformed nuclei are derived. Combined with direct numerical evaluations, these formulas are employed to reanalyse experimental data on the nuclear-charge-distribution parameters in $^{238}\\textrm{U}$ and to revise the nuclear-size corrections to the binding energies in H- and Li-like $^{238}\\textrm{U}$. As a result, the theoretical uncertainties for the ground-state Lamb shift in $^{238}\\textrm{U}^{91+}$ and for the $2p_{1/2}-2s$ transition energy in $^{238}\\textrm{U}^{89+}$ are significantly reduced. The isotope shift of the $2p_{j}-2s$ transition energies for $^{142}\\textrm{Nd}^{57+}$ and $^{150}\\textrm{Nd}^{57+}$ is also evaluated including nuclear size and nuclear recoil effects within a full QED treatment.

Kozhedub, Y S; Shabaev, V M; Tupitsyn, I I; Brandau, C; Kozhuharov, C; Plunien, G; Sthlker, T

2007-01-01T23:59:59.000Z

190

Heavy ion collisions: Correlations and Fluctuations in particle production  

E-Print Network (OSTI)

Correlations and fluctuations (the latter are directly related to the 2-particle correlations) is one of the important directions in analysis of heavy ion collisions. At the current stage of RHIC exploration, when the details matter, basically any physics question is addressed with help of correlation techniques. In this talk I start with a general introduction to the correlation and fluctuation formalism and discuss weak and strong sides of different type of observables. In more detail, I discuss the two-particle $p_t$ correlations/$\\mpt$ fluctuations. In spite of not observing any dramatic changes in the event-by-event fluctuations with energy, which would indicate a possible phase transition, such correlations measurements remain an interesting and important subject, bringing valuable information. Lastly, I show how radial flow can generate characteristic azimuthal, transverse momentum and rapidity correlations, which could qualitatively explain many of recently observed phenomena in nuclear collisions.

Sergei A. Voloshin

2005-05-02T23:59:59.000Z

191

From chemical freezeout to critical conditions in heavy ion collisions  

E-Print Network (OSTI)

We compare the statistical thermodynamics of hadron resonance gas with recent LGT results at finite chemical potential. We argue that for $T\\leq T_c$ the equation of state derived from Monte--Carlo simulations of two quark--flavor QCD at finite chemical potential is consistent with that of a hadron resonance gas when applying the same set of approximations as used in LGT calculations. We indicate the relation of chemical freezeout conditions obtained from a detailed analysis of particle production in heavy ion collisions with the critical conditions required for deconfinement. We argue that the position of a hadron--quark gluon boundary line in temperature chemical potential plane can be determined in terms of the resonance gas model by the condition of fixed energy density.

Krzysztof Redlich

2004-06-23T23:59:59.000Z

192

Development of long-lived thick carbon stripper foils for high energy heavy ion accelerators by a heavy ion beam sputtering method  

Science Conference Proceedings (OSTI)

In the past decade, we have developed extremely long-lived carbon stripper foils of 1-50 {mu}g/cm{sup 2} thickness prepared by a heavy ion beam sputtering method. These foils were mainly used for low energy heavy ion beams. Recently, high energy negative Hydrogen and heavy ion accelerators have started to use carbon stripper foils of over 100 {mu}g/cm{sup 2} in thickness. However, the heavy ion beam sputtering method was unsuccessful in production of foils thicker than about 50 {mu}g/cm{sup 2} because of the collapse of carbon particle build-up from substrates during the sputtering process. The reproduction probability of the foils was less than 25%, and most of them had surface defects. However, these defects were successfully eliminated by introducing higher beam energies of sputtering ions and a substrate heater during the sputtering process. In this report we describe a highly reproducible method for making thick carbon stripper foils by a heavy ion beam sputtering with a Krypton ion beam.

Muto, Hideshi [Center of General Education, Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino Nagano 391-0292 (Japan); Ohshiro, Yukimitsu [Center for Nuclear Study, School of Science, University of Tokyo, 2-1 Hirosawa, Riken Campus, Wako Saitama 351-0198 (Japan); Kawasaki, Katsunori [Van de Graaff Laboratory, Department of Physics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro Tokyo 152-8551 (Japan); Oyaizu, Michihiro [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba Ibaraki 305-0801 (Japan); Hattori, Toshiyuki [Heavy Ion Cancer Therapy Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage Chiba 263-855 (Japan)

2013-04-19T23:59:59.000Z

193

Effects of nuclear symmetry energy on eta meson production and its rare decay to the dark U-boson in heavy-ion reactions  

E-Print Network (OSTI)

Using a relativistic transport model ART1.0, we explore effects of nuclear symmetry energy on eta meson production and its rare decay to the dark U-boson in heavy-ion reactions from 0.2 to 10 GeV/nucleon available at several current and future facilities. The yield of eta mesons at sub-threshold energies is found to be very sensitive to the density dependence of nuclear symmetry energy. Above a beam energy of about 5 GeV/nucleon in Au+Au reactions, the sensitivity to symmetry energy disappears. Using the branching ratio of the rare eta decay (eta->gamma U) available in the literature, we estimate the maximum cross section for the U-boson production in the energy range considered, providing a useful reference for future U-boson search using heavy-ion reactions.

Gao-Chan Yong; Bao-An Li

2013-03-05T23:59:59.000Z

194

Effects of nuclear symmetry energy on eta meson production and its rare decay to the dark U-boson in heavy-ion reactions  

E-Print Network (OSTI)

Using a relativistic transport model ART1.0, we explore effects of nuclear symmetry energy on eta meson production and its rare decay to the dark U-boson in heavy-ion reactions from 0.2 to 10 GeV/nucleon available at several current and future facilities. The yield of eta mesons at sub-threshold energies is found to be very sensitive to the density dependence of nuclear symmetry energy. Above a beam energy of about 5 GeV/nucleon in Au+Au reactions, the sensitivity to symmetry energy disappears. Using the branching ratio of the rare eta decay (eta->gamma+U) available in the literature, we estimate the maximum cross section for the U-boson production in the energy range considered, providing a useful reference for future U-boson search using heavy-ion reactions.

Yong, Gao-Chan

2013-01-01T23:59:59.000Z

195

Elliptic flow of thermal photons in heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider  

E-Print Network (OSTI)

We calculate the thermal photon transverse momentum spectra and elliptic flow in $\\sqrt{s_{NN}} = 200$ GeV Au+Au collisions at RHIC and in $\\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb collisions at the LHC, using an ideal-hydrodynamical framework which is constrained by the measured hadron spectra at RHIC and LHC. The sensitivity of the results to the QCD-matter equation of state and to the photon emission rates is studied, and the photon $v_2$ is discussed in the light of the photonic $p_T$ spectrum measured by the PHENIX Collaboration. In particular, we make a prediction for the thermal photon $p_T$ spectra and elliptic flow for the current LHC Pb+Pb collisions.

Hannu Holopainen; Sami Rsnen; Kari J. Eskola

2011-04-28T23:59:59.000Z

196

A Scaled Final Focus Experiment for Heavy Ion Fusion  

SciTech Connect

A one-tenth dimensionally scaled version of a final focus sub-system design for a heavy ion fusion driver is built and tested. By properly scaling the physics parameters that relate particle energy and mass, beam current, beam emittance, and focusing field, the transverse dynamics of a driver scale final focus are replicated in a small laboratory beam. The experiment uses a 95 {micro}A beam of 160 keV Cs{sup +} ions to study the dynamics as the beam is brought to a ballistic focus in a lattice of six quadrupole magnets. Diagnostic stations along the experiment track the evolution of the transverse phase space of the beam. The measured focal spot size is consistent with calculations and the report of the design on which the experiment is based. By uniformly varying the strengths of the focusing fields in the lattice, the chromatic effect of a small energy deviation on the spot size can be reproduced. This is done for {+-}1% and {+-}2% shifts and the changes in the focus are measured. Additionally, a 400 {micro}A beam is propagated through the experiment and partially neutralized after the last magnet using electrons released from a hot tungsten filament. The increase in beam current allows for the observation of significant effects on both the size and shape of the focal spot when the electrons are added.

MacLaren, Stephan, Alexander

2000-09-19T23:59:59.000Z

197

Workshop on Accelerators for Heavy Ion Fusion: Summary Report of the Workshop  

SciTech Connect

The Workshop on Accelerators for Heavy Ion Fusion was held at Lawrence Berkeley National Laboratory May 23-26, 2011. The workshop began with plenary sessions to review the state of the art in HIF (heavy ion fusion), followed by parallel working groups, and concluded with a plenary session to review the results. There were five working groups: IFE (inertial fusion energy) targets, RF approach to HIF, induction accelerator approach to HIF, chamber and driver interface, ion sources and injectors.

Seidl, P.A.; Barnard, J.J.

2011-04-29T23:59:59.000Z

198

Atomic nuclei decay modes by spontaneous emission of heavy ions  

Science Conference Proceedings (OSTI)

The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic (/sup 208/Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of 10/sup 10/--10/sup 30/ s: /sup 5/He, /sup 8en-dash10/Be, /sup 11,12/B, /sup 12en-dash16/C, /sup 13en-dash17/N, /sup 15en-dash22/O, /sup 18en-dash23/F, /sup 20en-dash26/Ne, /sup 23en-dash28/Na, /sup 23en-dash30/Mg, /sup 27en-dash32/Al, /sup 28en-dash36/Si, /sup 31en-dash39/P, /sup 32en-dash42/S, /sup 35en-dash45/Cl, /sup 37en-dash47/Ar, /sup 40en-dash49/ K, . .Ca, /sup 44en-dash53/ Sc, /sup 46en-dash53/Ti, /sup 48en-dash54/V, and /sup 49en-dash55/ Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.

Poenaru, D.N.; Ivascu, M.; Sndulescu, A.; Greiner, W.

1985-08-01T23:59:59.000Z

199

Magnetic effects in heavy-ion collisions at intermediate energies  

E-Print Network (OSTI)

The time-evolution and space-distribution of internal electromagnetic fields in heavy-ion reactions at beam energies between 200 and 2000 MeV/nucleon are studied within an Isospin-dependent Boltzmann-Uhling-Uhlenbeck transport model IBUU11. While the magnetic field can reach about $7\\times 10^{16}$ G which is significantly higher than the estimated surface magnetic field ($\\sim 10^{15}$ G) of magnetars, it has almost no effect on nucleon observables as the Lorentz force is normally much weaker than the nuclear force. Very interestingly, however, the magnetic field generated by the projectile-like (target-like) spectator has a strong focusing/diverging effect on positive/negative pions at forward (backward) rapidities. Consequently, the differential $\\pi^-/\\pi^+$ ratio as a function of rapidity is significantly altered by the magnetic field while the total multiplicities of both positive and negative pions remain about the same. At beam energies above about 1 GeV/nucleon, while the integrated ratio of total $\\pi^-$ to $\\pi^+$ multiplicities is not, the differential $\\pi^-/\\pi^+$ ratio is sensitive to the density dependence of nuclear symmetry energy $E_{\\rm{sym}}(\\rho)$. Our findings suggest that magnetic effects should be carefully considered in future studies of using the differential $\\pi^-/\\pi^+$ ratio as a probe of the $E_{\\rm{sym}}(\\rho)$ at supra-saturation densities.

Li Ou; Bao-An Li

2011-07-16T23:59:59.000Z

200

Heavy Ion Beams for Investigation of Thermophysical Properties  

E-Print Network (OSTI)

Perspectives for study of thermophysical properties via uniform quasi-stationary volumetric heating under Heavy Ion Beam (HIB) heating with moderate but realistic energy deposition (~ 1 kJ/g) are under discussion. New quasi-isobaric regime of heating is proposed as combination of the HIB energy deposition with the use of highly dispersed porous material as an irradiating sample. Regime of "tracing saturation curve" is proposed also when heating the evaporating porous materials. Consequent preferences and priorities are emphasized. In frames of this technique HIB could became an uncompetitive tool for study of phase transition phenomenon for a wide number of materials with high-temperature location of critical point. Two important thermophysical problems, which could approve using of HIB facility, are discussed as the first-row candidates. Evaporation in Uranium is one of the most tempting candidates to be studied under HIB heating in such manner. When being successful this experiment has a good chance to resolve the old contradiction within the problem of Uranium critical point parameters estimations. The heating by HIB seems to be especially promising as an effective tool for systematic study of so-called "non-congruent" phase transition -- striking and mostly unusual sort of high-temperature phase equilibrium in chemically active strongly coupled plasmas. Phase transition in uranium dioxide is remarkable example of such non-congruency. New information on the thermophysical properties of phase transitions in uranium and uranium dioxide could be valuable for application in nuclear reactor safety analysis

Igor Iosilevskiy

2010-05-23T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields  

DOE Green Energy (OSTI)

Some years ago it was suggested that halogen negative ions [1]could offer a feasible alternative path to positive ions as a heavy ion fusion driver beam which would not suffer degradation due to electron accumulation in the accelerator and beam transport system, and which could be converted to a neutral beam by photodetachment near the chamber entrance if desired. Since then, experiments have demonstrated that negative halogen beams can be extracted and accelerated away from the gas plume near the source with a surviving current density close to what could be achieved with a positive ion of similar mass, and with comparable optical quality. In demonstrating the feasibility of halogen negative ions as heavy ion driver beams, ion - ion plasmas, an interesting and somewhat novel state of matter, were produced. These plasmas, produced near the extractor plane of the sources, appear, based upon many lines of experimental evidence, to consist of almost equal densities of positive and negative chlorine ions, with only a small component of free electrons. Serendipitously, the need to extract beams from this plasma for driver development provides a unique diagnostic tool to investigate the plasma, since each component - positive ions, negative ions, and electrons -- can be extracted and measured separately. We discuss the relevance of these observations to understanding negative ion beam extraction from electronegative plasmas such as halogens, or the more familiar hydrogen of magnetic fusion ion sources. We suggest a concept which might improve negative hydrogen extraction by the addition of a halogen. The possibility and challenges of producing ion-ion plasmas with thin targets of halogens or, perhaps, salt, is briefly addressed.

Grisham, L.R.; Kwan, J.W.

2008-08-01T23:59:59.000Z

202

Molecular dynamics simulations of swift heavy ion induced defect recovery in SiC  

SciTech Connect

Swift heavy ions induce a high density of electronic excitations that can cause the formation of amorphous ion tracks in insulators. No ion tracks have been observed in the semiconductor SiC, but recent experimental work suggests that irradiation damaged SiC can undergo defect recovery under swift heavy ion irradiation. It is believed that local heating of the lattice due to the electronic energy deposition can anneal, and thereby recover, some of the disordered structure. We simulate the local heating due to the ions by the inelastic thermal spike model and perform molecular dynamics simulations of dierent model damage states to study the defect recovery on an atomistic level. We find significant recovery of point defects and a disordered layer, as well as recrystallization at the amorphous-to-crystalline interface of an amorphous layer. The simulation results support the swift heavy ion annealing hypothesis.Swift heavy ions induce a high density of electronic excitations that can cause the formation of amorphous ion tracks in insulators. No ion tracks have been observed in the semiconductor SiC, but recent experimental work suggests that irradiation damaged SiC can undergo defect recovery under swift heavy ion irradiation. It is believed that local heating of the lattice due to the electronic energy deposition can anneal, and thereby recover, some of the disordered structure. We simulate the local heating due to the ions by the inelastic thermal spike model and perform molecular dynamics simulations of dierent model damage states to study the defect recovery on an atomistic level. We find significant recovery of point defects and a disordered layer, as well as recrystallization at the amorphous-to-crystalline interface of an amorphous layer. The simulation results support the swift heavy ion annealing hypothesis.

Backman, Marie [University of Tennessee, Knoxville (UTK); Toulemonde, Marcel [CEA-CNRS-ENSICAEN-University of Caen, FRANCE; Pakarinen, Olli H [University of Helsinki; Juslin, Niklas [University of Tennessee, Knoxville (UTK); Djurabekova, Flyura [University of Helsinki; Nordlund, Kai [University of Helsinki; Debelle, Aurelien [Universite Paris Sud, Orsay, France; Weber, William J [ORNL

2013-01-01T23:59:59.000Z

203

DOE - Office of Legacy Management -- Yale Heavy Ion Linear Accelerator - CT  

NLE Websites -- All DOE Office Websites (Extended Search)

Yale Heavy Ion Linear Accelerator - Yale Heavy Ion Linear Accelerator - CT 05 FUSRAP Considered Sites Site: Yale Heavy Ion Linear Accelerator (CT.05) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: New Haven , Connecticut CT.05-1 Evaluation Year: 1987 CT.05-3 Site Operations: Research and development with solvents. CT.05-1 Site Disposition: Eliminated - Potential for contamination remote based on limited amount of materials handled CT.05-3 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium, Radium CT.05-1 Radiological Survey(s): No Site Status: Eliminated from consideration under FUSRAP Also see Documents Related to Yale Heavy Ion Linear Accelerator CT.05-1 - MED Memorandum; To the Files, Thru Ruhoff, et. al.;

204

HEAVY ION FUSION HALF-YEAR REPORT APRIL 1, 1980 - SEPTEMBER 30, 1980  

E-Print Network (OSTI)

of Rochester Ravi N. Sudan KMS Fusion, Inc. Henry J. GombergOF CALIFORNIA Accelerator & Fusion Research DivisionHEAVY ION FUSION HALF-YEAR REPORT APRIL 1, 1980 - SEPTEMBER

Authors, Various

2010-01-01T23:59:59.000Z

205

Generation, transport and focusing of high-brightness heavy ion beams  

E-Print Network (OSTI)

The Neutralized Transport Experiment (NTX) has been built at the Heavy Ion Fusion Virtual National Laboratory. NTX is the first successful integrated beam system experiment that explores various physical phenomena, and ...

Henestroza, Enrique

2006-01-01T23:59:59.000Z

206

Direct drive heavy-ion-beam inertial fusion at high coupling efficiency  

E-Print Network (OSTI)

M J of fusion yield. This NIF capsule design ab- sorbs 200capsules the size of the NIF capsule with heavy-ion beams (designs emerge, and, if the NIF's ignition campaign is also

Logan, B.G.

2008-01-01T23:59:59.000Z

207

Direct Drive Heavy-Ion-Beam Inertial Fusion at High Coupling Efficiency  

E-Print Network (OSTI)

of fusion yield [16]. This NIF capsule design absorbs 200 kJcapsules the size of the NIF capsule with heavy ion beams (designs emerge, and, i f the NIF's ignition campaign is also

Logan, B. Grant

2008-01-01T23:59:59.000Z

208

Heavy-ion Collisions: Direct and indirect probes of the density and temperature dependence of Esym  

E-Print Network (OSTI)

Heavy-ion collisions provide a versatile terrestrial probe of the nuclear equation of state through the formation of nuclear matter at a wide variety of temperatures, densities, and pressures. Direct and indirect approaches for constraining the density dependence of the symmetry energy using heavy-ion collisions have been developed. The direct approach relies on scaling methods which attempt to connect isotopic fragment distributions to the symmetry energy. Using the indirect approach constraints on the equation of state are extracted from comparison of experimental results and theoretical transport calculations which utilize effective nucleon-nucleon interactions. Besides exploring the density dependence of the equation of state, heavy-ion collisions are simultaneously probing different temperature gradients of nuclear matter allowing for the temperature dependence of the symmetry energy to be examined. The current progress and open questions related to constraining the density and temperature dependence of the symmetry energy with heavy-ion collisions are discussed in the review.

Z. Kohley; S. J. Yennello

2014-01-22T23:59:59.000Z

209

Turbulent Transport and Heating of Trace Heavy Ions in Hot Magnetized Plasmas  

E-Print Network (OSTI)

Scaling laws for the transport and heating of trace heavy ions in low-frequency magnetized plasma turbulence are derived and compared with direct numerical simulations. The predicted dependences of turbulent fluxes and ...

Barnes, Michael

210

Heavy-ion-induced digital single event transients in a 180 nm fully depleted SOI process  

E-Print Network (OSTI)

Heavy-ion-induced single events transients (SETs) in advanced digital circuits are a significant reliability issue for space-based systems. SET pulse widths in silicon-on-insulator (SOI) technologies are often significantly ...

Gouker, Pascale M.

211

Scientific issues in future induction linac accelerators for heavy ion fusion  

E-Print Network (OSTI)

Miller, M. Tabak, Nuc. Fusion, 39, 883 (1999). [2] S.S. Yu,W.M. Sharp, D.R. Welch, Fusion Science and Technology, 44,Transport for Heavy Ion Fusion", in these proceedings. [18

Celata, C.M.

2004-01-01T23:59:59.000Z

212

Heavy Nuclei from RHIC to the Cosmos  

E-Print Network (OSTI)

Ultra-relativistic heavy ion collisions produce a high-temperature, thermalized system that may mimic the conditions present shortly after the big bang. This writeup will given an overview of early results from the Relativistic Heavy Ion Collider (RHIC), and discuss what we have learned about hot, strongly interacting nuclear systems. The thermal and chemical composition of the system will be discussed, along with observables that are sensitive to the early evolution of the system. I will also discuss the implications of the RHIC results for cosmic ray air showers.

Spencer R. Klein

2002-11-01T23:59:59.000Z

213

Recent Heavy Flavor Results at RHIC  

E-Print Network (OSTI)

We summarize the recent experimental results of heavy favor physics from the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Lab (BNL) at Long Island, New York, USA.We will discuss the directly reconstructed open charm mesons as well as electrons from heavy favor hadron decays. The charm and bottom quark production cross-sections have also been measured. We will also discuss JPsi and Upsilon states in p+p and heavy ion collisions. The studies described here were carried out and reported by the STAR and PHENIX collaborations at RHIC.

Wenqin Xu

2011-10-13T23:59:59.000Z

214

Studies of complex fragment emission in heavy ion reactions  

Science Conference Proceedings (OSTI)

Our work involves the study of intermediate energy heavy-ion nuclear reactions. This work has two foci. On the one hand, we desire to learn about the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities. This purpose runs abreast of the second, which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because our experimental laboratory for studying nuclear matter properties is a dynamic one. We are forced to ask how nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. It may be that irrefutable information about nuclear matter will not be extracted from the reaction work. Nevertheless, we are compelled to undertake this effort not only because it is the only game in town and as yet we do not know that information cannot be extracted, but also because of our second objective. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. Our program has been: To study energy, mass, and angular momentum deposition by studying incomplete fusion reactions. To gain confidence that we understand how highly excited systems decompose by studying all emissions from the highly excited systems. To push these kinds of studies into the intermediate energy domain, with excitation function studies. And attempt to learn about the dynamics of the decays using particle-particle correlations. In the last effort, we have decided to focus on simple systems, where we believe, definitive statements are possible. These avenues of research share a common theme, large complex fragment production.

Charity, R.J.; Sobotka, L.G.

1992-01-01T23:59:59.000Z

215

Relativistic shock waves in viscous gluon matter  

E-Print Network (OSTI)

We solve the relativistic Riemann problem in viscous gluon matter employing a microscopic parton cascade. We demonstrate the transition from ideal to viscous shock waves by varying the shear viscosity to entropy density ratio $\\eta/s$ from zero to infinity. We show that an $\\eta/s$ ratio larger than 0.2 prevents the development of well-defined shock waves on timescales typical for ultrarelativistic heavy-ion collisions. Comparisons with viscous hydrodynamic calculations confirm our findings.

I. Bouras; E. Molnar; H. Niemi; Z. Xu; A. El; O. Fochler; C. Greiner; D. H. Rischke

2009-02-11T23:59:59.000Z

216

Probing the Nuclear Symmetry Energy with Heavy-Ion Reactions Induced by Neutron-Rich Nuclei  

E-Print Network (OSTI)

Heavy-ion reactions induced by neutron-rich nuclei provide a unique means to investigate the equation of state of isospin-asymmetric nuclear matter, especially the density dependence of the nuclear symmetry energy. In particular, recent analyses of the isospin diffusion data in heavy-ion reactions have already put a stringent constraint on the nuclear symmetry energy around the nuclear matter saturation density. We review this exciting result and discuss its implications on nuclear effective interactions and the neutron skin thickness of heavy nuclei. In addition, we also review the theoretical progress on probing the high density behaviors of the nuclear symmetry energy in heavy-ion reactions induced by high energy radioactive beams.

Chen, Lie-Wen; Li, Bao-An; Yong, Gao-Chan

2007-01-01T23:59:59.000Z

217

Direct drive heavy-ion-beam inertial fusion at high coupling efficiency  

SciTech Connect

Issues with coupling efficiency, beam illumination symmetry, and Rayleigh-Taylor instability are discussed for spherical heavy-ion-beam-driven targets with and without hohlraums. Efficient coupling of heavy-ion beams to compress direct-drive inertial fusion targets without hohlraums is found to require ion range increasing several-fold during the drive pulse. One-dimensional implosion calculations using the LASNEX inertial confinement fusion target physics code shows the ion range increasing fourfold during the drive pulse to keep ion energy deposition following closely behind the imploding ablation front, resulting in high coupling efficiencies (shell kinetic energy/incident beam energy of 16% to 18%). Ways to increase beam ion range while mitigating Rayleigh-Taylor instabilities are discussed for future work.

Logan, B.G.; Perkins, L.J.; Barnard, J.J.

2008-05-16T23:59:59.000Z

218

Modeling of Heavy Metals Ions Adsorption by Polyamidoamine ...  

Science Conference Proceedings (OSTI)

... that employ PAMAM dendrimers for adsorption of heavy metals from wastewater. ... Heat Treatment of Black Dross for the Production of a Value Added Material ... Mullites Bodies Produced From the Kaolin Residue Using Microwave Energy.

219

Swift heavy ion irradiation of Pt nanocrystals: I. shape transformation and dissolution  

Science Conference Proceedings (OSTI)

We report on the effects of swift heavy ion irradiation of embedded Pt nanocrystals (NCs), which change from spheres to prolate spheroids to rods upon irradiation. Using a broad range of ion irradiation energies and NC mean sizes we demonstrate that the elongation and dissolution processes are energy and size dependent, attaining comparable levels of shape transformation and dissolution upon a given energy density deposited in the matrix. The NC shape transformation remains operative despite discontinuous ion tracks in the matrix and exhibits a constant threshold size for elongation. In contrast, for ion irradiations in which the ion tracks are continuous, the threshold size for elongation is clearly energy dependent.

Giulian, R.; Araujo, L.L.; Kluth, P.; Sprouster, D.J.; Schnohr, C.S.; Byrne, A.P.; Ridgway, M.C. (ANU)

2011-12-09T23:59:59.000Z

220

HIGH-ENERGY HEAVY-ION BEAMS AS IGNITERS FOR COMMERCIAL-SCALE INTERTIAL-FUSION POWER PLANTS  

E-Print Network (OSTI)

Nucl. Proceedings of the Brookhaven Workshop on Heavy IonOctober 17-21, 1977- Brookhaven National Laboratory Report (the physics of Argonne, Brookhaven, Lawrence Berkeley, and

Judd, D.L.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
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221

Proton and heavy ion upsets in GaAs MESFET devices  

Science Conference Proceedings (OSTI)

This paper reports on proton and heavy SEU data that has been obtained for devices made by several GaAs MESFET manufacturers. Proton energy dependence and proton and heavy ion upset cross sections are reported. Measurements of charge collection from latches designed with various gate widths show that charge collection depths appear deeper than the 1 {mu}m depth expected. Critical charge does not scale linearly with area. Proton upset cross sections are reduced with increased device width.

Weatherford, T.R.; Tran, L. (Sachs/Freeman Associates, Inc., Bowie, MD (United States)); Stapor, W.J.; Petersen, E.L.; Langworthy, J.B.; McMorrow, D. (Naval Research Lab., Washington, DC (United States)); Abdel-Kader, W.G.; McNulty, P.J. (Clemson Univ., SC (United States). Dept. of Physics and Astronomy)

1991-12-01T23:59:59.000Z

222

Cost reduction possibilities for a heavy-ion accelerator for inertial confinement fusion  

SciTech Connect

A design was produced for a single module in a cost-optimized accelerator appropriate for a commercial heavy-ion power plant. The goal of the study was to determine if the cost of the accelerator module could be reduced through design options, selection of materials, and manufacturing techniques. Independent cost estimates were obtained for the three main components of the module, and cost reductions of 20% from the cost calculated by the heavy-ion accelerator design/cost-minimization computer code LIACEP were identified. 3 refs., 23 figs.

Thayer, G.R.; Sims, J.R.; Henke, M.D.; Harris, D.B.; Dudziak, D.J.; Phillips, N.R.

1987-10-01T23:59:59.000Z

223

Lattice QCD and Hydro/Cascade Model of Heavy Ion Collisions  

E-Print Network (OSTI)

We report here on a recent lattice study of the QCD transition region at finite temperature and zero chemical potential using domain wall fermions (DWF). We also present a parameterization of the QCD equation of state obtained from lattice QCD that is suitable for use in hydrodynamics studies of heavy ion collisions. Finally, we show preliminary results from a multi-stage hydrodynamics/hadron cascade model of a heavy ion collision, in an attempt to understand how well the experimental data (e.g. particle spectra, elliptic flow, and HBT radii) can constrain the inputs (e.g. initial temperature, freezeout temperature, shear viscosity, equation of state) of the theoretical model.

Michael Cheng

2010-05-11T23:59:59.000Z

224

Doorway state expansion approach to coupled channels problems and application to heavy ions  

SciTech Connect

The doorway expansion method is extended to coupled channels problems in low energy heavy ion collisions. As a test, it is applied to an exactly soluble model and the convergence problem is discussed. The method is then applied to heavy ion elastic scattering due to the optical potential and to a simple coupled channels problem. In both cases very good convergence is reached with six doorway states. The calculation with a single doorway is shown to be much better than the DWBA. 9 refs., 8 figs., 1 tab.

Breitschaft, A.M.S.; Canto, L.F.; Schechter, H. (Universidade Federal do Rio de Janeiro (Brazil)); Hussein, M.S. (Universidade de Sao Paulo (Brazil)); Moniz, E.J. (Massachusetts Institute of Technology, Cambridge, MA (United States))

1994-08-15T23:59:59.000Z

225

Photon decay in strong magnetic field in heavy-ion collisions  

E-Print Network (OSTI)

We calculate the photon pair production rate in strong magnetic field created in off-central heavy-ion collisions. Photon decay leads to depletion of the photon yield by a few percent at RHIC and by as much as 20% at the LHC. It also generates a substantial azimuthal asymmetry ("elliptic flow") of the final photon distribution. We estimate v_2~2% at RHIC and v_2~14% at LHC. Photon decay measurements is an important tool for studying the magnetic fields in early stages of heavy-ion collisions.

Tuchin, Kirill

2010-01-01T23:59:59.000Z

226

The Multi-Purpose Detector for NICA heavy-Ion Collider at JINR  

Science Conference Proceedings (OSTI)

The Multi-Purpose Detector (MPD) is designed to study heavy-ion collisions at the Nuclotron-based heavy Ion Collider fAcility (NICA) at JINR, Dubna. Its main components located inside a superconducting solenoid are a tracking system composed of a silicon microstrip vertex detector followed by a large volume time-projection chamber, a time-of-flight system for particle identification and a barrel electromagnetic calorimeter. A zero degree hadron calorimeter is designed specifically to measure the energy of spectators. In this paper, all parts of the apparatus are described and their tracking and particle identification parameters are discussed in some detail.

Rogachevsky, O. V., E-mail: rogachevsky@jinr.ru [JINR, Veksler and Baldin Laboratory on High Energy Physics (Russian Federation)

2012-05-15T23:59:59.000Z

227

Lattice QCD and Hydro/Cascade Model of Heavy Ion Collisions  

E-Print Network (OSTI)

We report here on a recent lattice study of the QCD transition region at finite temperature and zero chemical potential using domain wall fermions (DWF). We also present a parameterization of the QCD equation of state obtained from lattice QCD that is suitable for use in hydrodynamics studies of heavy ion collisions. Finally, we show preliminary results from a multi-stage hydrodynamics/hadron cascade model of a heavy ion collision, in an attempt to understand how well the experimental data (e.g. particle spectra, elliptic flow, and HBT radii) can constrain the inputs (e.g. initial temperature, freezeout temperature, shear viscosity, equation of state) of the theoretical model.

Cheng, Michael

2010-01-01T23:59:59.000Z

228

System-size independence of directed flow at the Relativistic Heavy-Ion Collider  

E-Print Network (OSTI)

We measure directed flow ($v_1$) for charged particles in Au+Au and Cu+Cu collisions at $\\sqrt{s_{NN}} =$ 200 GeV and 62.4 GeV, as a function of pseudorapidity ($\\eta$), transverse momentum ($p_t$) and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all existing models, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to different collision systems, and investigate possible explanations for the observed sign change in $v_1(p_t)$.

STAR Collaboration; B. I. Abelev

2008-07-09T23:59:59.000Z

229

EXPERIMENTS WITH RELATIVISTIC HEAVY IONS: A POTPOURRI OF CHEMISTRY, CANIS MAJORIS AND GRAINS OF SILVER  

E-Print Network (OSTI)

the f i r s t by B. Judek, NRC, who studied the PFs o f 0 atLBL. The r e s u l t s of the NRC and LBL experiments werel i c l e s , with stack I (NRC) c o n t a i n i n g 50 p e

Heckman, H.H.

2010-01-01T23:59:59.000Z

230

Transverse Energy Measurement and Fluctuation Studies in Ultra-Relativistic Heavy Ion Collisions  

E-Print Network (OSTI)

Transverse energy ($E_T$) has been measured with both of it's components, namely hadronic ($E_T^{had}$) and electromagnetic ($E_T^{em}$) at mid-rapidity, for 62.4 GeV Au+Au collisions by the STAR experiment. In the common phase space of TPC and BEMC ($0 tower hits after correcting for the hadronic contaminations in the calorimeter. The centrality behavior of $/(0.5 N_{part})$ and the excitation function of $/(0.5 N_{part})$ has been compared with the final state gluon saturation model (EKRT) along with similar measurements from SPS to RHIC. The most striking feature is the observation of a nearly constant value of $E_T/N_{ch} \\sim 0.8$ GeV from AGS, SPS to RHIC. The $E_T$ and $N_{ch}$ production has been observed to follow a logarithmic behavior. The initial energy density estimated by the boost-invariant Bjorken hydrodynamic model, is well above the lattice QCD value for a deconfined matter of Quarks and Gluons. Taking similar colliding species i.e. Au+Au, the $\\epsilon_{Bj} .\\tau$ has been predicted for LHC, based on the measurements at RHIC. We have also made predictions for $(dE_T/d\\eta)/(0.5 N_{part})$ and $(dN_{ch}/d\\eta)/(0.5 N_{part})$ for the LHC energy. Furthermore, we have studied the event-by event fluctuations in $E_T$ and in the ratio of it's components using $\\sigma/\\mu$ as the fluctuation observable.

Raghunath Sahoo

2008-04-10T23:59:59.000Z

231

Trends in Yield and Azimuthal Shape Modification in Dihadron Correlations in Relativistic Heavy Ion Collisions  

E-Print Network (OSTI)

Fast parton probes produced by hard scattering and embedded within collisions of large nuclei have shown that partons suffer large energy loss and that the produced medium may respond collectively to the lost energy. We present measurements of neutral pion trigger particles at transverse momenta p^t_T = 4-12 GeV/c and associated charged hadrons (p^a_T = 0.5-7 GeV/c) as a function of relative azimuthal angle Delta Phi at midrapidity in Au+Au and p+p collisions at sqrt(s_NN) = 200 GeV. These data lead to two major observations. First, the relative angular distribution of low momentum hadrons, whose shape modification has been interpreted as a medium response to parton energy loss, is found to be modified only for p^t_T < 7 GeV/c. At higher p^t_T, the data are consistent with unmodified or very weakly modified shapes, even for the lowest measured p^a_T. This observation presents a quantitative challenge to medium response scenarios. Second, the associated yield of hadrons opposite to the trigger particle in Au+Au relative to that in p+p (I_AA) is found to be suppressed at large momentum (IAA ~ 0.35-0.5), but less than the single particle nuclear modification factor (R_AA ~0.2).

A. Adare; S. Afanasiev; C. Aidala; N. N. Ajitanand; Y. Akiba; H. Al-Bataineh; J. Alexander; T. Alho; K. Aoki; L. Aphecetche; Y. Aramaki; J. Asai; E. T. Atomssa; R. Averbeck; T. C. Awes; B. Azmoun; V. Babintsev; M. Bai; G. Baksay; L. Baksay; A. Baldisseri; K. N. Barish; P. D. Barnes; B. Bassalleck; A. T. Basye; S. Bathe; S. Batsouli; V. Baublis; C. Baumann; A. Bazilevsky; S. Belikov; R. Belmont; R. Bennett; A. Berdnikov; Y. Berdnikov; A. A. Bickley; J. G. Boissevain; J. S. Bok; H. Borel; K. Boyle; M. L. Brooks; H. Buesching; V. Bumazhnov; G. Bunce; S. Butsyk; C. M. Camacho; S. Campbell; B. S. Chang; W. C. Chang; J. -L. Charvet; C. -H. Chen; S. Chernichenko; C. Y. Chi; M. Chiu; I. J. Choi; R. K. Choudhury; P. Christiansen; T. Chujo; P. Chung; A. Churyn; O. Chvala; V. Cianciolo; Z. Citron; B. A. Cole; M. Connors; P. Constantin; M. Csand; T. Csrg?; T. Dahms; S. Dairaku; I. Danchev; K. Das; A. Datta; G. David; A. Denisov; D. d'Enterria; A. Deshpande; E. J. Desmond; O. Dietzsch; A. Dion; M. Donadelli; O. Drapier; A. Drees; K. A. Drees; A. K. Dubey; M. Durham; A. Durum; D. Dutta; V. Dzhordzhadze; S. Edwards; Y. V. Efremenko; F. Ellinghaus; T. Engelmore; A. Enokizono; H. En'yo; S. Esumi; K. O. Eyser; B. Fadem; D. E. Fields; M. Finger; \\, Jr.; M. Finger; F. Fleuret; S. L. Fokin; Z. Fraenkel; J. E. Frantz; A. Franz; A. D. Frawley; K. Fujiwara; Y. Fukao; T. Fusayasu; I. Garishvili; A. Glenn; H. Gong; M. Gonin; J. Gosset; Y. Goto; R. Granier de Cassagnac; N. Grau; S. V. Greene; M. Grosse Perdekamp; T. Gunji; H. -. Gustafsson; A. Hadj Henni; J. S. Haggerty; I. Hahn; H. Hamagaki; J. Hamblen; J. Hanks; R. Han; E. P. Hartouni; K. Haruna; E. Haslum; R. Hayano; M. Heffner; S. Hegyi; T. K. Hemmick; T. Hester; X. He; J. C. Hill; M. Hohlmann; W. Holzmann; K. Homma; B. Hong; T. Horaguchi; D. Hornback; S. Huang; T. Ichihara; R. Ichimiya; J. Ide; Y. Ikeda; K. Imai; J. Imrek; M. Inaba; D. Isenhower; M. Ishihara; T. Isobe; M. Issah; A. Isupov; D. Ivanischev; B. V. Jacak; J. Jia; J. Jin; B. M. Johnson; K. S. Joo; D. Jouan; D. S. Jumper; F. Kajihara; S. Kametani; N. Kamihara; J. Kamin; J. H. Kang; J. Kapustinsky; D. Kawall; M. Kawashima; A. V. Kazantsev; T. Kempel; A. Khanzadeev; K. M. Kijima; J. Kikuchi; B. I. Kim; D. H. Kim; D. J. Kim; E. -J. Kim; E. Kim; S. H. Kim; Y. J. Kim; E. Kinney; K. Kiriluk; A. Kiss; E. Kistenev; J. Klay; C. Klein-Boesing; L. Kochenda; B. Komkov; M. Konno; J. Koster; D. Kotchetkov; A. Kozlov; A. Krl; A. Kravitz; G. J. Kunde; K. Kurita; M. Kurosawa; M. J. Kweon; Y. Kwon; G. S. Kyle; R. Lacey; Y. S. Lai; J. G. Lajoie; D. Layton; A. Lebedev; D. M. Lee; J. Lee; K. B. Lee; K. Lee; K. S. Lee; T. Lee; M. J. Leitch; M. A. L. Leite; E. Leitner; B. Lenzi; P. Liebing; L. A. Linden Levy; T. Lika; A. Litvinenko; H. Liu; M. X. Liu; X. Li; B. Love; R. Luechtenborg; D. Lynch; C. F. Maguire; Y. I. Makdisi; A. Malakhov; M. D. Malik; V. I. Manko; E. Mannel; Y. Mao; L. Maek; H. Masui; F. Matathias; M. McCumber; P. L. McGaughey; N. Means; B. Meredith; Y. Miake; A. Mignerey; P. Mike; K. Miki; A. Milov; M. Mishra; J. T. Mitchell; A. K. Mohanty; Y. Morino; A. Morreale; D. P. Morrison; T. V. Moukhanova; D. Mukhopadhyay; J. Murata; S. Nagamiya; J. L. Nagle; M. Naglis; M. I. Nagy; I. Nakagawa; Y. Nakamiya; T. Nakamura; K. Nakano; J. Newby; M. Nguyen; T. Niita; R. Nouicer; A. S. Nyanin; E. O'Brien; S. X. Oda; C. A. Ogilvie; H. Okada; K. Okada; M. Oka; Y. Onuki; A. Oskarsson; M. Ouchida; K. Ozawa; R. Pak; A. P. T. Palounek; V. Pantuev; V. Papavassiliou; I. Park; J. Park; S. K. Park; W. J. Park; S. F. Pate; H. Pei; J. -C. Peng; H. Pereira; V. Peresedov; D. Yu. Peressounko; C. Pinkenburg; R. P. Pisani; M. Proissl; M. L. Purschke; A. K. Purwar; H. Qu; J. Rak; A. Rakotozafindrabe; I. Ravinovich; K. F. Read; S. Rembeczki; K. Reygers; V. Riabov; Y. Riabov; E. Richardson; D. Roach; G. Roche; S. D. Rolnick; M. Rosati; C. A. Rosen; S. S. E. Rosendahl; P. Rosnet; P. Rukoyatkin; P. Rui?ka; V. L. Rykov; B. Sahlmueller; N. Saito; T. Sakaguchi; S. Sakai; K. Sakashita; V. Samsonov; S. Sano; T. Sato; S. Sawada; K. Sedgwick; J. Seele; R. Seidl; A. Yu. Semenov; V. Semenov; R. Seto; D. Sharma; I. Shein; T. -A. Shibata; K. Shigaki; M. Shimomura; K. Shoji; P. Shukla; A. Sickles; C. L. Silva; D. Silvermyr; C. Silvestre; K. S. Sim; B. K. Singh; C. P. Singh; V. Singh; M. Slune?ka; A. Soldatov; R. A. Soltz; W. E. Sondheim; S. P. Sorensen; I. V. Sourikova; N. A. Sparks; F. Staley; P. W. Stankus; E. Stenlund; M. Stepanov; A. Ster; S. P. Stoll; T. Sugitate; C. Suire; A. Sukhanov; J. Sziklai; E. M. Takagui; A. Taketani; R. Tanabe; Y. Tanaka; K. Tanida; M. J. Tannenbaum; S. Tarafdar; A. Taranenko; P. Tarjn; H. Themann; T. L. Thomas; M. Togawa; A. Toia; L. Tomek; Y. Tomita; H. Torii; R. S. Towell; V-N. Tram; I. Tserruya; Y. Tsuchimoto; C. Vale; H. Valle; H. W. van Hecke; E. Vazquez-Zambrano; A. Veicht; J. Velkovska; R. Vertesi

2010-02-04T23:59:59.000Z

232

SINGLE ELECTRON ATTACHMENT AND STRIPPING CROSS SECTIONS FOR RELATIVISTIC HEAVY IONS  

E-Print Network (OSTI)

of atomic number Z? -l. An event trigger was defined as athe particle generating an event trigger passed through thewas that, whenever an event trigger was accepted, the CPU

Crawford, H.J.

2010-01-01T23:59:59.000Z

233

More than mass proportional heating of heavy ions by supercritical collisionless shocks in the solar corona  

E-Print Network (OSTI)

We propose a new model for explaining the observations of more than mass proportional heating of heavy ions in the polar solar corona. We point out that a large number of small scale intermittent shock waves can be present in the solar corona. The energization mechanism is, essentially, the ion reflection off supercritical quasi-perpendicular collisionless shocks in the corona and the subsequent acceleration by the motional electric field ${\\bf E} = - (1/c) {\\bf V} \\times {\\bf B}$. The acceleration due to ${\\bf E}$ is perpendicular to the magnetic field, in agreement with observations, and is more than mass proportional with respect to protons, because the heavy ion orbit is mostly upstream of the quasi-perpendicular shock foot. The observed temperature ratios between O$^{5+}$ ions and protons in the polar corona, and between $\\alpha$ particles and protons in the solar wind are easily recovered.

Zimbardo, Gaetano

2009-01-01T23:59:59.000Z

234

Solar-wind protons and heavy ions sputtering of lunar surface materials A.F. Barghouty a,  

E-Print Network (OSTI)

Solar-wind protons and heavy ions sputtering of lunar surface materials A.F. Barghouty a, , F Available online 21 December 2010 Keywords: Solar wind sputtering Lunar regolith KREEP soil Potential a c t Lunar surface materials are exposed to $1 keV/amu solar-wind protons and heavy ions on almost

235

Targets for high-resolution studies with heavy-ion reactions  

SciTech Connect

Target problems in heavy ion reaction studies are discussed, including non-uniformity in thickness effects and the inability to fully compensate for reaction-site effects, both problems becoming more serious the heavier the ion. For the non-uniformity effects, the flatness of the target is very critical. Other problems not yet solved are beam-spot heating and the buildup of carbon. (PMA)

Erskine, J.R.

1975-01-01T23:59:59.000Z

236

Cascade Problems in Some Atomic Lifetime Measurements at a Heavy-Ion Storage Ring  

SciTech Connect

Lifetimes of 3s{sup 2}3p{sup k} ground configuration levels of Al-, Si-, P-, and S-like ions of Be, Co, and Ni have been measured at a heavy-ion storage ring. Some of the observed decay curves show strong evidence of cascade repopulation from specific 3d levels that feature lifetimes in the same multi-millisecond range as the levels of the ground configuration.

Tr?bert, E; Hoffmann, J; Krantz, C; Wolf, A; Ishikawa, Y; Santana, J

2008-10-09T23:59:59.000Z

237

Joe W. Kwan U.S. Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL)  

E-Print Network (OSTI)

Washington DC December 5, 2012 Heavy Ion Fusion Science Virtual National Laboratory #12;We presented to NAS diameter spot 0.03 J/cm2 (50 ns window) 5.3 J/cm2 (0.6 ns window) Fluence w/in focal radius & FWHM duration

238

Biological and medical research with accelerated heavy ions at the Bevalac, 1977-1980. [Lead abstract  

SciTech Connect

Separate abstracts were prepared for the 46 papers presented in this progress report. This report is a major review of studies with accelerated heavy ions carried out by the Biology and Medicine Division of Lawrence Berkeley Laboratory from 1977 to 1980. (KRM)

Pirruccello, M.C.; Tobias, C.A. (eds.)

1980-11-01T23:59:59.000Z

239

A study of total reaction cross section models used in particle and heavy ion transport codes  

Science Conference Proceedings (OSTI)

Understanding the interactions and propagations of high energy protons and heavy ions are essential when trying to estimate the biological effects of Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE) on personnel in space.12 To be able to calculate ...

L. Sihver; M. Lantz

2011-03-01T23:59:59.000Z

240

Simulation of an RFQ (radio-frequency quadruple) funnel for heavy-ion beams  

Science Conference Proceedings (OSTI)

Use of the magnetic force to focus and deflect heavy-ion beams is marginal at low ion velocities. Low-emittance-growth funnels using discrete magnetic elements are difficult to design for these beams. We show that a new type of radio-frequency quadruple (RFQ) funnel is especially suitable for this application. Simulation procedures, which include space-charge and image effects, have produced a high-quality funnel design for 20-MeV Bi/sup +1/ ions. 4 refs., 4 figs., 2 tabs.

Guy, F.W.; Stokes, R.H.

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Trends in Device See Susceptibility from Heavy Ions  

E-Print Network (OSTI)

it-r April, , was in entry in can now ask what parameters or arc to writes in Almost all 1 E 1 soft usually in "write" One or two devices be than preliminary partial data. test is Specific Arrays (GA) `1 1 for arc! in t a show that widely, as" process. gate! array however; `1 several rather hard, soft thresholds and no for including variations, an ONO Applied Laboratory. In has 1 ions (Au and 1) and ions 1. E 1>43 is voltage (5 V). A. Swift (18) permanent failure may from (SE day devices is but attempts to harden Manufacturers arc! with thinner a n d Voltage may more sensitive this is also to 1 Arrays Devices A's were! tested this All fairly soft error an 1 7 `1 A's anti A resistant to 1 data that up hardening used. In but not always It is a of that inclusion not an iron clad guarantee against because the thickness may great for the device. how thin the epi thickness must cannot answered an experimental data it depends intrinsic of in Linear 1 devices have mu

D.K. Nichols; J.R. Coss; K.P. McCarty

1995-01-01T23:59:59.000Z

242

Review of multi-dimensional large-scale kinetic simulation and physics validation of ion acceleration in relativistic laser-matter interaction  

Science Conference Proceedings (OSTI)

Two new experimental technologies enabled realization of Break-out afterburner (BOA) - High quality Trident laser and free-standing C nm-targets. VPIC is an powerful tool for fundamental research of relativistic laser-matter interaction. Predictions from VPIC are validated - Novel BOA and Solitary ion acceleration mechanisms. VPIC is a fully explicit Particle In Cell (PIC) code: models plasma as billions of macro-particles moving on a computational mesh. VPIC particle advance (which typically dominates computation) has been optimized extensively for many different supercomputers. Laser-driven ions lead to realization promising applications - Ion-based fast ignition; active interrogation, hadron therapy.

Wu, Hui-Chun [Los Alamos National Laboratory; Hegelich, B.M. [Los Alamos National Laboratory; Fernandez, J.C. [Los Alamos National Laboratory; Shah, R.C. [Los Alamos National Laboratory; Palaniyappan, S. [Los Alamos National Laboratory; Jung, D. [Los Alamos National Laboratory; Yin, L [Los Alamos National Laboratory; Albright, B.J. [Los Alamos National Laboratory; Bowers, K. [Guest Scientist of XCP-6; Huang, C. [Los Alamos National Laboratory; Kwan, T.J. [Los Alamos National Laboratory

2012-06-19T23:59:59.000Z

243

Heavy ion and proton analysis of a GaAs C-HIGFET SCRAM  

Science Conference Proceedings (OSTI)

The authors present heavy ion and proton upset measurements, including total dose, and displacement damage on a one micron, GaAs, complementary-heterostructure insulated-gate FET (C-HIGFET) 1k x 1 SRAM. SEU characteristics show a two order of magnitude improvement over GaAs MESFET technology. Heavy-ion upset equilibrium measurements show that all cells upset with equal probability at the five percent LET threshold. This indicates that for this device the shape of the cross section versus LET curve is a result of a probability distribution that applies to all cells and is not the result of variations in cell sensitivities. The data set also indicates that the traditional two-dimensional cos([theta]) normalization to LET and fluence are not applicable to this technology.

Cutchin, J.H.; Marshall, P.W.; Weatherford, T.R. (SFA Inc., Landover, MD (United States) Naval Research Lab., Washington, DC (United States)); Langworthy, J.; Petersen, E.L.; Campbell, A.B. (Naval Research Lab., Washington, DC (United States)); Hanka, S.; Peczalski, A. (Honeywell, Inc., Minneapolis, MN (United States))

1993-12-01T23:59:59.000Z

244

A survey of energy loss calculations for heavy ions between 1 and 100 keV  

E-Print Network (OSTI)

The original Lindhard-Scharff-Schitt (LSS) theory and the more recent Tilinin theory for calculating the nuclear and electronic stopping powers of slow heavy ions are compared with predictions from the SRIM code by Ziegler. While little discrepancies are present for the nuclear contribution to the energy loss, large differences are found in the electronic one. When full ion recoil cascade simulations are tested against the elastic neutron scattering data available in the literature, it can be concluded that the LSS theory is the more accurate.

J. Pinto Da Cunha A; P. Sona D

2007-01-01T23:59:59.000Z

245

Biosorption of heavy metal ions to brown algae, Macrocystis pyrifera, Kjellmaniella crassiforia, and Undaria pinnatifida  

SciTech Connect

A fundamental study of the application of brown algae to the aqueous-phase separation of toxic heavy metals was carried out. The biosorption characteristics of cadmium and lead ions were determined with brown algae, Macrocystis pyrifera, Kjellmaniella crassiforia, and Undaria pinnatifida. A metal binding model proposed by the authors was used for the description of metal binding data. The results showed that the biosorption of bivalent metal ions to brown algae was due to bivalent binding to carboxylic groups on alginic acid in brown algae.

Seki, Hideshi; Suzuki, Akira [Hokkaido Univ., Hakodate (Japan)

1998-10-01T23:59:59.000Z

246

Actinide Production in the Reaction of Heavy Ions withCurium-248  

Science Conference Proceedings (OSTI)

Chemical experiments were performed to examine the usefulness of heavy ion transfer reactions in producing new, neutron-rich actinide nuclides. A general quasi-elastic to deep-inelastic mechanism is proposed, and the utility of this method as opposed to other methods (e.g. complete fusion) is discussed. The relative merits of various techniques of actinide target synthesis are discussed. A description is given of a target system designed to remove the large amounts of heat generated by the passage of a heavy ion beam through matter, thereby maximizing the beam intensity which can be safely used in an experiment. Also described is a general separation scheme for the actinide elements from protactinium (Z = 91) to mendelevium (Z = 101), and fast specific procedures for plutonium, americium and berkelium. The cross sections for the production of several nuclides from the bombardment of {sup 248}Cm with {sup 18}O, {sup 86}Kr and {sup 136}Xe projectiles at several energies near and below the Coulomb barrier were determined. The results are compared with yields from {sup 48}Ca and {sup 238}U bombardments of {sup 248}Cm. Simple extrapolation of the product yields into unknown regions of charge and mass indicates that the use of heavy ion transfer reactions to produce new, neutron-rich above-target species is limited. The substantial production of neutron-rich below-target species, however, indicates that with very heavy ions like {sup 136}Xe and {sup 238}U the new species {sup 248}Am, {sup 249}Am and {sup 247}Pu should be produced with large cross sections from a {sup 248}Cm target. A preliminary, unsuccessful attempt to isolate {sup 247}Pu is outlined. The failure is probably due to the half life of the decay, which is calculated to be less than 3 minutes. The absolute gamma ray intensities from {sup 251}Bk decay, necessary for calculating the {sup 251}Bk cross section, are also determined.

Moody, K.J.

1983-07-01T23:59:59.000Z

247

Photon production from non-equilibrium QGP in heavy ion collisions  

E-Print Network (OSTI)

We present a calculation of thermal photon production i.e. photons from secondary interactions among particles produced in heavy ion collisions at collider energies. This is done within the framework of hydrodynamics. We take into account the lack of chemical equilibrium in QGP. It turns out that main effects from chemical non-equilibrium composition of QGP, reduction of particle number and increase in temperature, nearly cancel in photon spectrum.

F. Gelis; H. Niemi; P. V. Ruuskanen; S. S. Rasanen

2004-03-15T23:59:59.000Z

248

Coupled-Channel Effects in Collisions between Heavy Ions near the Coulomb Barrier  

E-Print Network (OSTI)

With the recent availability of state-of-the-art heavy-ion stable and radioactive beams, there has been a renew interest in the investigation of nuclear reactions with heavy ions. I first present the role of inelastic and transfer channel couplings in fusion reactions induced by stable heavy ions. Analysis of experimental fusion cross sections by using standard coupled-channel calculations is discussed. The role of multi-neutron transfer is investigated in the fusion process below the Coulomb barrier by analyzing $^{32}$S+$^{90,96}$Zr as benchmark reactions. The enhancement of fusion cross sections for $^{32}$S+$^{96}$Zr is well reproduced at sub-barrier energies by NTFus code calculations including the coupling of the neutron-transfer channels following the Zagrebaev semi-classical model. Similar effects for $^{40}$Ca+$^{90}$Zr and $^{40}$Ca+$^{96}$Zr fusion excitation functions are found. The breakup coupling in both the elastic scattering and in the fusion process induced by weakly bound stable projectiles is also shown to be crucial. In this lecture, full coupled-channel calculations of the fusion excitation functions are performed by using the breakup coupling for the more neutron-rich reaction and for the more weakly bound projectiles. I clearly demonstrate that Continuum-Discretized Coupled-Channel calculations are capable to reproduce the fusion enhancement from the breakup coupling in $^{6}$Li+$^{59}$Co.

C. Beck

2012-05-21T23:59:59.000Z

249

Coupled-Channel Effects in Collisions between Heavy Ions near the Coulomb Barrier  

E-Print Network (OSTI)

With the recent availability of state-of-the-art heavy-ion stable and radioactive beams, there has been a renew interest in the investigation of nuclear reactions with heavy ions. I first present the role of inelastic and transfer channel couplings in fusion reactions induced by stable heavy ions. Analysis of experimental fusion cross sections by using standard coupled-channel calculations is discussed. The role of multi-neutron transfer is investigated in the fusion process below the Coulomb barrier by analyzing $^{32}$S+$^{90,96}$Zr as benchmark reactions. The enhancement of fusion cross sections for $^{32}$S+$^{96}$Zr is well reproduced at sub-barrier energies by NTFus code calculations including the coupling of the neutron-transfer channels following the Zagrebaev semi-classical model. Similar effects for $^{40}$Ca+$^{90}$Zr and $^{40}$Ca+$^{96}$Zr fusion excitation functions are found. The breakup coupling in both the elastic scattering and in the fusion process induced by weakly bound stable projectiles...

Beck, C

2013-01-01T23:59:59.000Z

250

Overview of Theory and Modeling in the Heavy Ion Fusion Virtual National Laboratory  

Science Conference Proceedings (OSTI)

This paper presents analytical and simulation studies of intense heavy ion beam propagation, including the injection, acceleration, transport and compression phases, and beam transport and focusing in background plasma in the target chamber. Analytical theory and simulations that support the High Current Experiment (HCX), the Neutralized Transport Experiment (NTX), and the advanced injector development program are being used to provide a basic understanding of the nonlinear beam dynamics and collective processes, and to develop design concepts for the next-step Integrated Beam Experiment (IBX), an Integrated Research Experiment (IRE), and a heavy ion fusion driver. Three-dimensional (3-D) nonlinear perturbative simulations have been applied to collective instabilities driven by beam temperature anisotropy and to two-stream interactions between the beam ions and any unwanted background electrons. Three-dimensional particle-in-cell simulations of the 2 MV Electrostatic Quadrupole (ESQ) injector have clarified the influence of pulse rise time. Analytical studies and simulations of the drift compression process have been carried out. Syntheses of a four-dimensional (4-D) particle distribution function from phase-space projections have been developed. And, studies of the generation and trapping of stray electrons in the beam self-fields have been performed. Particle-in-cell simulations, involving preformed plasma, are being used to study the influence of charge and current neutralization on the focusing of the ion beam in Neutralized Transport Experiment and in a fusion chamber.

R.C. Davidson, I.D. Kaganovich, W.W. Lee, H. Qin, E.A. Startsev; S. Tzenov; A. Friedman; J.J. Barnard; R.H. Cohen; D.P. Grote; S.M. Lund; W.M. Sharp; C.M. Celata, M. de Hoon; E. Henestroza; E.P. Lee; S.S. Yu; J.-L. Vay; D.R. Welch; D.V. Rose; C.L. Olson

2003-04-09T23:59:59.000Z

251

Semiconductor detectors for medical tomography with high-energy heavy ions  

SciTech Connect

High-energy heavy ion beams are in use at the Lawrence Berkeley Laboratory for cancer therapy. In order to take full advantage of the very favorable depth-dose characteristics of those beams, it is necessary to determine the stopping characteristics of the ions in the complex media of a human with greater accuracy than obtainable with x-ray CAT scanning. Initial measurements with an array of Si dE/dx position sensitive detectors and a windowless thin planar Ge detector used in a side entry mode show the potential for fabricating an instrument for high accuracy on-line CAT scanning using the same ions to be used for therapy. It is estimated that one tomography can be obtained with a dose of 0.72 Rad-gm.

Llacer, J.; Haller, E.E.; Hansen, W.L.; Walton, J.T.; Batho, E.K.

1980-11-01T23:59:59.000Z

252

The new computer program for three dimensional relativistic hydrodynamical model  

E-Print Network (OSTI)

An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.

Daniel Kikola; Wiktor Peryt; Yuri M. Sinyukov; Marcin Slodkowski; Marek Szuba

2006-01-30T23:59:59.000Z

253

High-injection carrier dynamics generated by MeV heavy ions impacting high-speed photodetectors  

Science Conference Proceedings (OSTI)

The generation of single event transients generated by the impact of high-energy ions in high-speed photodetectors leads to bit error rate degradation in optical communications in radiation hard environments such as space. High-energy heavy ions

Jamie Stuart Laird

2005-01-01T23:59:59.000Z

254

Removal of heavy metal ions from oil shale beneficiation process water by ferrite process  

SciTech Connect

The ferrite process is an established technique for removing heavy metals from waste water. Because the process water resulting from oil shale beneficiation falls into the category of industrial waste water, it is anticipated that this process may turn out to be a potential viable treatment for oil shale beneficiation process water containing many heave metal ions. The process is chemoremedial because not only effluent water comply with quality standards, but harmful heavy metals are converted into a valuable, chemically stable by-product known as ferrite. These spinel ferrites have magnetic properties, and therefore can be use in applications such as magnetic marker, ferrofluid, microwave absorbing and scavenging material. Experimental results from this process are presented along with results of treatment technique such as sulfide precipitation.

Mehta, R.K.; Zhang, L.; Lamont, W.E.; Schultz, C.W. (Alabama Univ., University, AL (United States). Mineral Resources Inst.)

1991-01-01T23:59:59.000Z

255

Removal of heavy metal ions from oil shale beneficiation process water by ferrite process  

SciTech Connect

The ferrite process is an established technique for removing heavy metals from waste water. Because the process water resulting from oil shale beneficiation falls into the category of industrial waste water, it is anticipated that this process may turn out to be a potential viable treatment for oil shale beneficiation process water containing many heave metal ions. The process is chemoremedial because not only effluent water comply with quality standards, but harmful heavy metals are converted into a valuable, chemically stable by-product known as ferrite. These spinel ferrites have magnetic properties, and therefore can be use in applications such as magnetic marker, ferrofluid, microwave absorbing and scavenging material. Experimental results from this process are presented along with results of treatment technique such as sulfide precipitation.

Mehta, R.K.; Zhang, L.; Lamont, W.E.; Schultz, C.W. [Alabama Univ., University, AL (United States). Mineral Resources Inst.

1991-12-31T23:59:59.000Z

256

Benchmarking Heavy Ion Transport Codes FLUKA, HETC-HEDS MARS15, MCNPX, and PHITS  

Science Conference Proceedings (OSTI)

Powerful accelerators such as spallation neutron sources, muon-collider/neutrino facilities, and rare isotope beam facilities must be designed with the consideration that they handle the beam power reliably and safely, and they must be optimized to yield maximum performance relative to their design requirements. The simulation codes used for design purposes must produce reliable results. If not, component and facility designs can become costly, have limited lifetime and usefulness, and could even be unsafe. The objective of this proposal is to assess the performance of the currently available codes â?? PHITS, FLUKA, MARS15, MCNPX, and HETC-HEDS â?? that could be used for design simulations involving heavy ion transport. We plan to access their performance by performing simulations and comparing results against experimental data of benchmark quality. Quantitative knowledge of the biases and the uncertainties of the simulations is essential as this potentially impacts the safe, reliable and cost effective design of any future radioactive ion beam facility. Further benchmarking of heavy-ion transport codes was one of the actions recommended in the â??Report of the 2003 RIA R&D Workshop".

Ronningen, Reginald Martin [Michigan State University; Remec, Igor [Oak Ridge National Laboratory; Heilbronn, Lawrence H. [University of Tennessee-Knoxville

2013-06-07T23:59:59.000Z

257

U.S. Heavy Ion Beam Science towards inertial fusion energy  

DOE Green Energy (OSTI)

Significant experimental and theoretical progress in the U.S heavy-ion fusion (HIF) program is reported in modeling and measurements of intense space-charge-dominated heavy ion and electron beams. Measurements of the transport of a well-matched and aligned high current (0.2A) 1.0 MeV potassium ion beam through 10 electric quadrupoles, with a fill factor of 60%, shows no emittance growth within experimental measurement uncertainty, as expected from the simulations. Another experiment shows that passing a beam through an aperture can reduce emittance to near the theoretical limits, and that plasma neutralization of the beam's space-charge can greatly reduce the focal spot radius. Measurements of intense beamlet current density, emittance, charge-state purity, and energy spread from a new, high-brightness, Argon plasma source for HIF experiments are described. New theory and simulations of neutralization of intense beam space charge with plasma in various focusing chamber configurations indicate that near-emittance-limited beam focal spot sizes can be obtained even with beam perveance an order of magnitude higher than in earlier HIF focusing experiments.

Logan, B.G.; Baca, D.; Barnard, J.J.; Bieniosek, F.M.; Burkhart, C.; Celata, C.M.; Chacon-Golcher, E.; Cohen, R.H.; Davidson, R.C.; Efthimion P.; Faltens, A.; Friedman, A.; Grisham, L.; Grote, D.P.; Haber, I.; Henestroza, E.; Kaganovich, I.; Kishek, R.A.; Kwan, J.W.; Lee, E.P.; Lee, W.W.; Leitner, M.; Lund, S.M.; Meier, W.R.; Molvik, A.W.; O'Shea, P.G.; Olson, C.; Olson, R.E.; Prost, L.R.; Qin, H.; Reiser, M.; Rose, D.; Sabbi, G.; Seidl, P.A.; Sharp, W.M.; Shuman, D.B.; Vay, J-L.; Waldron, W.L.; Welch, D.; Westenskow, G.A.; Yu, S.S.

2002-10-01T23:59:59.000Z

258

Heavy quark production from jet conversions in a quark-gluon plasma  

E-Print Network (OSTI)

Recently, it has been demonstrated that the chemical composition of jets in heavy ion collisions is significantly altered compared to the jets in the vacuum. This signal can be used to probe the medium formed in nuclear collisions. In this study we investigate the possibility that fast light quarks and gluons can convert to heavy quarks when passing through a quark-gluon plasma. We study the rate of light to heavy jet conversions in a consistent Fokker-Planck framework and investigate their impact on the production of high-p(T) charm and bottom quarks at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

Liu, W.; Fries, Rainer J.

2008-01-01T23:59:59.000Z

259

Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Quarkonium Production in Elementary and Heavy Ion Collisions  

Science Conference Proceedings (OSTI)

Understanding the structure of the hadron is of fundamental importance in subatomic physics. Production of heavy quarkonia is arguably one of the most fascinating subjects in strong interaction physics. It offers unique perspectives into the formation of QCD bound states. Heavy quarkonia are among the most studied particles both theoretically and experimentally. They have been, and continue to be, the focus of measurements in all high energy colliders around the world. Because of their distinct multiple mass scales, heavy quarkonia were suggested as a probe of the hot quark-gluon matter produced in heavy-ion collisions; and their production has been one of the main subjects of the experimental heavy-ion programs at the SPS and RHIC. However, since the discovery of J/psi at Brookhaven National Laboratory and SLAC National Accelerator Laboratory over 36 years ago, theorists still have not been able to fully understand the production mechanism of heavy quarkonia, although major progresses have been made in recent years. With this in mind, a two-week program on quarkonium production was organized at BNL on June 6-17, 2011. Many new experimental data from LHC and from RHIC were presented during the program, including results from the LHC heavy ion run. To analyze and correctly interpret these measurements, and in order to quantify properties of the hot matter produced in heavy-ion collisions, it is necessary to improve our theoretical understanding of quarkonium production. Therefore, a wide range of theoretical aspects on the production mechanism in the vacuum as well as in cold nuclear and hot quark-gluon medium were discussed during the program from the controlled calculations in QCD and its effective theories such as NRQCD to various models, and to the first principle lattice calculation. The scientific program was divided into three major scientific parts: basic production mechanism for heavy quarkonium in vacuum or in high energy elementary collisions; the formation of quarkonium in nuclear medium as well as the strong interacting quark-gluon matter produced in heavy ion collisions; and heavy quarkonium properties from the first principle lattice calculations. The heavy quarkonium production at a future Electron-Ion Collider (EIC) was also discussed at the meeting. The highlight of the meeting was the apparent success of the NRQCD approach at next-to-leading order in the description of the quarkonium production in proton-proton, electron-proton and electron positron collisions. Still many questions remain open in lattice calculations of in-medium quarkonium properties and in the area of cold nuclear matter effects.

Dumitru, A.; Lourenco, C.; Petreczky, P.; Qiu, J., Ruan, L.

2011-08-03T23:59:59.000Z

260

Fission Decay Widths for Heavy-Ion Fusion-Fission Reactions  

E-Print Network (OSTI)

Cross-section and neutron-emission data from heavy-ion fusion-fission reactions are consistent with a Kramers-modified statistical model which takes into account the collective motion of the system about the ground state; the temperature dependence of the location of fission transition points; and the orientation degree of freedom. We see no evidence to suggest that the nuclear viscosity departs from the surface-plus-window dissipation model. The strong increase in the nuclear viscosity above a temperature of ~1 MeV deduced by others is an artifact generated by an inadequate fission model.

S. G. McCalla; J. P. Lestone

2008-01-30T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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261

Modified Fragmentation Function in Heavy Ion Collisions at RHIC via Direct photon-Jet Measurements  

E-Print Network (OSTI)

The presented results are the first measurements at RHIC for direct $\\gamma$-charged hadron azimuthal correlations in heavy ion collisions. We use these correlations to study the color charge density of the medium through the medium-induced modification of high-p$_T$ parton fragmentation. Azimuthal correlations of direct photons at high transverse energy (8 $direct photons and photons from the decays of high p$_T$ $\\pi^{0}$. The per-trigger away-side yield of direct $\\gamma$ is smaller than from $\\pi^{0}$ trigger at the same centrality class. Within the current uncertainty the I$_{CP}$ of direct $\\gamma$ and $\\pi^{0}$ are similar.

Ahmed M. Hamed

2008-09-08T23:59:59.000Z

262

Estimation of electric conductivity of the quark gluon plasma via asymmetric heavy-ion collisions  

E-Print Network (OSTI)

We show that in asymmetric heavy-ion collisions, especially off-central Cu+Au collisions, a sizable strength of electric field directed from Au nucleus to Cu nucleus is generated in the overlapping region, because of the difference in the number of electric charges between the two nuclei. This electric field would induce an electric current in the matter created after the collision, which result in a dipole deformation of the charge distribution. The directed flow parameters $v_1^{\\pm}$ of charged particles turn out to be sensitive to the charge dipole and provide us with information about electric conductivity of the quark gluon plasma.

Yuji Hirono; Masaru Hongo; Tetsufumi Hirano

2012-11-06T23:59:59.000Z

263

Criterion for the applicability of standard thermodynamics in heavy ion collisions  

Science Conference Proceedings (OSTI)

The use of integrals as approximations for discrete sums in microcanonical equilibrium calculations is valid in the thermodynamic limit. We derive a criterion for testing the validity of this approximation for the relatively small volumes encountered in heavy ion collision fireballs. Numerical examples with CERN and BNL parameters show that there is a real possibility that continuous calculations for the hadronic gas are not accurate. By means of an example, we illustrate the dangers of using canonical and grand canonical methods without first testing whether assumptions underlying their use are valid. Detailed investigations are now required to test the difference between continuous and discrete calculations.

Eggers, H.C.; Heinz, U. (Institut fuer Theoretische Physik, Universitaet Regensburg, Postfach 10 10 42, DW-8400 Regensburg (Germany))

1993-08-01T23:59:59.000Z

264

The performance of a double sided silicon strip detector as a transmission detector for heavy ions  

E-Print Network (OSTI)

The performance of a double sided silicon strip detector (DSSSD), used for position and energy detection of heavy ions, is reported. The analysis shows that the incomplete charge collection (ICC) and charge sharing (CS) effects of the DSSSD give rise to a loss of energy resolution, however the position information is recorded without ambiguity. Representations of ICC/CS events in the energy spectra are shown and their origins are confirmed by correlation analysis of the spectra from both junction side and ohmic side of the DSSSD.

J L Han; J B Ma; X G Cao; Q Wang; J S Wang; Y Y Yang; P Ma; M R Huang; S L Jin; X J Rong; Z Bai; F Fu; Q Hu; R F Chen; S W Xu; J B Chen; L Jin; Y Li; M H Zhao; H S Xu

2013-07-16T23:59:59.000Z

265

Design and testing of the magnetic quadrupole for the Heavy Ion Fusion Program  

SciTech Connect

The Heavy Ion Fusion Program at the Lawrence Berkeley Laboratory is conducting experiments in the transport and acceleration of ``driverlike`` beams. The single beam coming from the four-to-one beam combiner will be transported in a lattice of pulsed magnetic quadrupoles. The present beam transport consists of high field, short aspect ratio magnetic quadrupoles to maximize the transportable current. This design could also be converted to be superconducting for future uses in a driver. The pulsed quadrupole will develop a maximum field of two Tesla and will be housed within the induction accelerator cells at the appropriate lattice period. Hardware implementation of the physics requirements and full parameter testing is described.

Benjegerdes, R.; Faltens, A.; Fawley, W.; Peters, C.; Reginato, L.; Stuart, M.

1995-04-01T23:59:59.000Z

266

What have we learned and want to learn from heavy ion collisions at CERN SPS?  

E-Print Network (OSTI)

The talk is a mini-review of the current status of the field, with emphasis on SPS heavy ion program, now and beyond 2000 (as asked by the organizers). The main question is, of course, whether we can convince ourselves and the community at large that the QGP is in fact produced at SPS. We came a long way toward the positive answer, and are definitely on strongly rising part of the learning curve. Still, in few key directions we lack important pieces of evidences.

E. V. Shuryak

1999-06-21T23:59:59.000Z

267

Interplay between compound and fragments aspects of nuclear fission and heavy-ion reaction  

SciTech Connect

The scission point in nuclear fission plays a special role where one-body system changes to two-body system. Inverse of this situation is realized in heavy-ion fusion reaction where two-body system changes to one body system. Among several peculiar phenomena expected to occur during this change, we focus our attention to the behavior of compound and fragments shell effects. Some aspects of the interplay between compound and fragments shell effect are discussed related to the topics of the fission valleys in the potential energy surface of actinide nuclei and the fusion-like trajectory found in the cold fusion reaction leading to superheavy nuclei.

Moller, Peter [Los Alamos National Laboratory; Iwamoto, A [JAPAN; Ichikawa, I [JAPAN

2010-09-10T23:59:59.000Z

268

Time-Depentent Hartree-Fock description of heavy ions fusion  

E-Print Network (OSTI)

A microscopic mean-field description of heavy ions fusion is performed in the framework of the Time-Dependent Hartree-Fock (TDHF) theory using a Skyrme interaction with the SLy4d parametrization. A good agreement with experiments is obtained on the position of the fusion barriers for various total masses, mass asymmetries and deformations. The excitation function of the 16O+208Pb is overestimated by about 16% above the barrier. The restriction to an independent particles state in the mean-field dynamics prevents the description of sub-barrier fusion. Effect of transfer on fusion is discussed.

Cdric Simenel; Benot Avez

2007-11-06T23:59:59.000Z

269

Off-momentum dynamic aperture for lattices in the RHIC heavy ion runs  

Science Conference Proceedings (OSTI)

To reduce transverse emittance growth rates from intrabeam scattering in the RHIC heavy ion runs, a lattice with an increased phase advance in the arc FODO cells was adopted in 2008-2011. During these runs, a large beam loss due to limited off-momentum dynamic aperture was observed during longitudinal RF re-bucketing and with transverse cooling. Based on the beam loss observations in the previous ion runs and the calculated off-momentum apertures, we decided to adopt the lattice used before 2008 for the 2012 U-U and Cu-Au runs. The observed beam decay and the measured momentum aperture in the 2012 U-U run are presented.

Luo Y.; Bai, M.; Blaskiewicz, M.; Gu, X.; Fischer, W.; Marusic, A.; Roser, T.; Tepikian, S.; Zhang, S.

2012-05-20T23:59:59.000Z

270

Relativistic configuration-interaction calculations of the n=3-3 transition energies in highly charged tungsten ions  

SciTech Connect

A large-scale relativistic configuration-interaction calculation of the n=3-3 transition energies for Ne- to Ar-like tungsten is carried out. The calculation is based on the relativistic no-pair Hamiltonian and uses finite B-spline orbitals in a cavity as basis functions. Quantum electrodynamic and mass polarization corrections are also included. Results are compared with other theories and with experiment, and are generally found to be more reliable than previous theoretical predictions.

Chen, M. H.; Cheng, K. T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2011-07-15T23:59:59.000Z

271

Electrostatic waves in a relativistic and anisotropic plasma stream electron waves and ion-acoustic mode: Fusion instability  

SciTech Connect

The electrostatic dispersion and instabilities for an anisotropic relativistic plasma stream are analytically studied for various regimes with streaming dissipation relevant to the analysis of fusion and turbulence in beam-plasma and wave-plasma interaction. It reveals the modified spectrum of streaming dispersion and onset of instability at nonrelativistic temperatures suitable for space, at moderately relativistic temperature including fusion, and at ultrarelativistic temperature limit relevant to astrophysical plasmas and pulsars.

Mohanty, J.N.

1983-11-01T23:59:59.000Z

272

Pre-saddle neutron multiplicity for fission reactions induced by heavy ions and light particles  

E-Print Network (OSTI)

Pre-saddle neutron multiplicity has been calculated for several fission reactions induced by heavy ions and light particles. Experimentally, it is impossible to determine the contribution of neutrons being emitted before the saddle point and those emitted between the saddle and the scission points. Determination of the pre-saddle neutron multiplicity in our research is based on the comparison between the experimental anisotropies and those predicted by the standard saddle-point statistical model. Analysis of the results shows that the pre-saddle neutron multiplicity depends on the fission barrier height and stability of the compound nucleus. In heavy ion induced fission, the number of pre-saddle neutrons decreases with increasing the excitation energy of the compound nucleus. A main cause of this behavior is due to a reduction in the ground state-to-saddle point transition time with increasing the excitation energy of the compound nucleus. Whereas in induced fission by light particles, the number of pre-saddle neutrons increases with increasing the excitation energy of the compound nucleus.

S. Soheyli; M. K. Khalili

2013-06-03T23:59:59.000Z

273

A high-intensity plasma-sputter heavy negative ion source  

SciTech Connect

A multicusp magnetic field plasma surface ion source, normally used for H/sup /minus//ion beam formation, has been modified for the generation of high-intensity, pulsed, heavy negative ion beams suitable for a variety of uses. To date, the source has been utilized to produce mA intensity pulsed beams of more than 24 species. A brief description of the source, and basic pulsed-mode operational data, (e.g., intensity versus cesium oven temperature, sputter probe voltage, and discharge pressure), are given. In addition, illustrative examples of intensity versus time and the mass distributions of ion beams extracted from a number of samples along with emittance data, are also presented. Preliminary results obtained during dc operation of the source under low discharge power conditions suggest that sources of this type may also be used to produce high-intensity (mA) dc beams. The results of these investigations are given, as well, and the technical issues that must be addressed for this mode of operation are discussed. 15 refs., 10 figs., 2 tabs.

Alton, G.D.; Mori, Y.; Takagi, A.; Ueno, A.; Fukumoto, S.

1989-01-01T23:59:59.000Z

274

The european FAZIA initiative: a high-performance digital telescope array for heavy-ion studies  

E-Print Network (OSTI)

The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification also via pulse shape analysis. The achievement of top performances imposes specific electronics which has been developed by FAZIA and features high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program centered on experiments to be done with the demonstrator. First results on the isospin dynamics obtained with a reduced set-up demonstrate well the performance of the telescope and represent a good starting point towards future investigations with both stable and exotic beams.

G. Casini; S. Barlini; G. Pasquali; G. Pastore; M. Bini; S. Carboni; A. Olmi; S. Piantelli; G. Poggi; A. Stefanini; S. Valdre'; E. Bonnet; B. Borderie; R. Bougault; M. Bruno; A. Chbihi; M. Cinausero; M. Degerlier; P. Edelbruck; J. D. Frankland; F. Gramegna; D. Gruyer; M. Guerzoni; A. Kordjasz; T. Kozik; N. Le Neindre; O. Lopez; T. Marchi; P. Marini; L. Morelli; A. Ordine; M. Parlog; M. F. Rivet; E. Rosato; F. Salomon; G. Spadaccini; T. Twarog; E. Vient; M. Vigilante

2013-09-05T23:59:59.000Z

275

Comment on the article 'Solitary waves and double layers in an ultra-relativistic degenerate dusty electron-positron-ion plasma'[Phys. Plasmas 19, 033705 (2012)  

SciTech Connect

More recently, Roy et al.[Phys. Plasmas 19, 033705 (2012)] have investigated the occurrence of nonlinear solitary and double-layers in an ultrarelativistic dusty electron-positron-ion degenerate plasma using a Sagdeev potential method. They have considered a full parametric examination on Mach-number criteria for existence of such nonlinear excitations using the specific degeneracy limits of Chandrasekhar equation of state (EoS) for Fermi-Dirac plasmas. In this comment, we point-out a misleading extension of polytropic EoS to study the Fermi-Dirac relativistically degenerate plasmas.

Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan University of Tarbiat Moallem, 51745-406 Tabriz (Iran, Islamic Republic of)

2012-06-15T23:59:59.000Z

276

Relativistic shock waves and the excitation of plerions  

Science Conference Proceedings (OSTI)

The shock termination of a relativistic magnetohydrodynamic wind from a pulsar is the most interesting and viable model for the excitation of the synchrotron sources observed in plerionic supernova remnants. We have studied the structure of relativistic magnetosonic shock waves in plasmas composed purely of electrons and positrons, as well as those whose composition includes heavy ions as a minority constituent by number. We find that relativistic shocks in symmetric pair plasmas create fully thermalized distributions of particles and fields downstream. Therefore, such shocks are not good candidates for the mechanism which converts rotational energy lost from a pulsar into the nonthermal synchrotron emission observed in plerions. However, when the upstream wind contains heavy ions which are minority constituent by number density, but carry the bulk of the energy density, much of the energy of the shock goes into a downstream, nonthermal power law distribution of positrons with energy distribution N(E)dE {proportional to}E{sup {minus}s}. In a specific model presented in some detail, s = 3. These characteristics are close to those assumed for the pairs in macroscopic MHD wind models of plerion excitation. The essential mechanism is collective synchrotron emission of left-handed extraordinary modes by the ions in the shock front at high harmonics of the ion cyclotron frequency, with the downstream positrons preferentially absorbing almost all of this radiation, mostly at their fundamental (relativistic) cyclotron frequencies. Possible applications to models of plerions and to constraints on theories of energy loss from pulsars are briefly outlines. 27 refs., 5 figs.

Arons, J. (California Univ., Berkeley, CA (USA)); Gallant, Y.A. (California Univ., Berkeley, CA (USA). Dept. of Physics); Hoshino, Masahiro; Max, C.E. (California Univ., Livermore, CA (USA). Inst. of Geophysics and Planetary Physics); Langdon, A.B. (Lawrence Livermore National Lab., CA (USA))

1991-01-07T23:59:59.000Z

277

Incorporation of the effect of the composite electric fields of molecular ions as a simulation tool for biological damage due to heavy-ion irradiation  

Science Conference Proceedings (OSTI)

This paper presents a theoretical study of the DNA damage due to the effect of the composite electric fields of H{sub 2}O{sup +} ions produced from the irradiation of a heavy ion onto a cell. A model for atomic and molecular processes in strong electric fields is developed. It is found that the composite electric fields increase the number of events of electron-impact ionization processes. This may promote DNA damage.

Moribayashi, Kengo [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1-7 Umemidai, Kizugawa-City, Kyoto 619-0215 (Japan) and Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe City, Kyoto 610-0394 (Japan)

2011-07-15T23:59:59.000Z

278

Swift heavy-ion irradiation-induced shape and structural transformation in cobalt nanoparticles  

Science Conference Proceedings (OSTI)

The shape and structural evolution of Co nanoparticles embedded in SiO{sub 2} and subjected to swift heavy-ion irradiation have been investigated over a wide energy and fluence range. Modifications of the nanoparticle size and shape were characterized with transmission electron microscopy and small-angle x-ray scattering. Nanoparticles below a threshold diameter remained spherical in shape and progressively decreased in size under irradiation due to dissolution. Nanoparticles above the threshold diameter transformed into nanorods with their major dimension parallel to the incident ion direction. Modifications of the atomic-scale structure of the Co nanoparticles were identified with x-ray absorption spectroscopy. Analysis of the x-ray absorption near-edge spectra showed that prior to irradiation all Co atoms were in a metallic state, while after irradiation Co atoms were in both oxidized and metallic environments, the former consistent with dissolution. The evolution of the nanoparticle short-range order was determined from extended x-ray absorption fine structure spectroscopy. Structural changes in the Co nanoparticles as a function of ion fluence included an increase in disorder and asymmetric deviation from a Gaussian interatomic distance distribution coupled with a decrease in bondlength. Such changes resulted from the irradiation-induced decrease in nanoparticle size and subsequent dissolution.

Sprouster, D.J.; Giulian, R.; Araujo, L.L.; Kluth, P.; Johannessen, B.; Cookson, D.J.; Ridgway, M.C. (Aust. Synch.); (ANU)

2012-02-07T23:59:59.000Z

279

Melting of Dense Hydrogen during Heavy Ion Beam-Driven Compression  

DOE Green Energy (OSTI)

Until now the thermodynamic and structural properties of hydrogen continue to be understood unsatisfactory. A number of complex high pressure phases at relatively low temperatures has been confirmed [1]. However, conclusive answers on the existence of a plasma phase transition, the dissociation of hydrogen molecules at high densities, the metallization in the solid, and the melting line for pressures above 70GPa are still missing. A particularly interesting behavior has been predicted for the melting line at high pressures where it has a maximum and its slope changes sign [2]. In Ref. [3], we have shown that these states can be created using cylindrical compression driven by heavy ion beams. Employing ab initio simulations [4] and experimental data, a new wide range equation of state for hydrogen was constructed [3]. This new hydrogen EOS combined with hydrodynamic simulations is then used to describe the compression of hydrogen in LAPLAS targets [5] driven by heavy ion beams to be generated at the FAIR. The results shown in Fig. 1 indicate that the melting line up to its maximum as well as the transition from molecular fluids to fully ionized plasmas can be tested. By carefully tuning the number of particles in the beam, the compression can be adjusted to yield states at the solid-liquid phase transition (compare panels (a) and (b) in Fig. 1). This allows one to test the shape of the melting line beyond its maximum. It was demonstrated [3] that x-ray scattering [6] can be used to distinguish between the molecular solid and liquid phases as well as the metallic states. Hydrodynamic simulations have also highlighted the importance of temperature diagnostics, as it is more sensitive to the EOS than the density based diagnostic methods. Different materials have been considered as absorber. Although lead might seem to be the natural choice, the simulations show that aluminium is also a feasible option if slightly less compression is sufficient. Moreover, aluminium offers further options for testing by x-ray scattering and, thus, might be favorable compared to lead drivers. In summary, valuable information on the properties of high-density hydrogen can be obtained by dynamic compression with heavy ion beams. The long standing questions of the plasma phase transition, melting, and metallization can be addressed. The calculated Jupiter isentrope shown in Fig. 1 indicates that such experiments would be also highly beneficial for the giant planet modeling.

Grinenko, A; Gericke, D O; Vorberger, J; Glenzer, S H

2009-03-02T23:59:59.000Z

280

Dynamical approach to heavy-ion induced fusion using actinide target  

Science Conference Proceedings (OSTI)

To treat heavy-ion reactions using actinide target nucleus, we propose a model which takes into account the coupling to the collective states of interacting nuclei in the penetration of the Coulomb barrier and the dynamical evolution of nuclear shape from the contact configuration. A fluctuation-dissipation model (Langevin equation) was applied in the dynamical calculation, where effect of nuclear orientation at the initial impact on the prolately deformed target nucleus was considered. Using this model, we analyzed the experimental data for the mass distribution of fission fragments (MDFF) in the reaction of {sup 36}S+{sup 238}U at several incident energies. Fusion-fission, quasifission and deep-quasi-fission are separated as different trajectories on the potential energy surface. We estimated the fusion cross section of the reaction.

Aritomo, Y.; Hagino, K.; Chiba, S.; Nishio, K. [Flerov Laboratory of Nuclear Reactions, JINR, Dubna, 141980 (Russian Federation); Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195 (Japan)

2012-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Photon HBT interferometry for non-central heavy-ion collisions  

E-Print Network (OSTI)

Currently, the only known way to obtain experimental information about the space-time structure of a heavy-ion collision is through 2-particle momentum correlations. Azimuthally sensitive HBT interferometry (Hanbury Brown-Twiss intensity interferometry) can complement elliptic flow measurements by constraining the spatial deformation of the source and its time evolution. Performing these measurements on photons allows us to access the fireball evolution at earlier times than with hadrons. Using ideal hydrodynamics to model the space-time evolution of the collision fireball, we explore theoretically various aspects of 2-photon intensity interferometry with transverse momenta up to 2 GeV, in particular the azimuthal angle dependence of the HBT radii in non-central collisions. We highlight the dual nature of thermal photon emission, in both central and non-central collisions, resulting from the superposition of QGP and hadron resonance gas photon production. This signature is present in both the thermal photon s...

Frodermann, Evan

2009-01-01T23:59:59.000Z

282

Heavy Ion Beam in Resolution of the Critical Point Problem for Uranium and Uranium Dioxide  

E-Print Network (OSTI)

Important advantages of heavy ion beam (HIB) irradiation of matter are discussed in comparison with traditional sources - laser heating, electron beam, electrical discharge etc. High penetration length (~ 10 mm) is of primary importance for investigation of dense matter properties. This gives an extraordinary chance to reach the uniform heating regime when HIB irradiation is being used for thermophysical property measurements. Advantages of HIB heating of highly-dispersive samples are claimed for providing free and relatively slow quasi-isobaric heating without fast hydrodynamic expansion of heated sample. Perspective of such HIB application are revised for resolution of long-time thermophysical problems for uranium and uranium-bearing compounds (UO2). The priorities in such HIB development are stressed: preferable energy levels, beam-time duration, beam focusing, deposition of the sample etc.

Igor Iosilevskiy; Victor Gryaznov

2010-05-23T23:59:59.000Z

283

Strangeness Production close to Threshold in Proton-Nucleus and Heavy-Ion Collisions  

E-Print Network (OSTI)

We discuss strangeness production close to threshold in p+A and A+A collision. Comparing the body of available K+, K0, K-, and Lambda data with the IQMD transport code and for some key observables as well with the HSD transport code, we find good agreement for the large majority of the observables. The investigation of the reaction with help of these codes reveals the complicated interaction of the strange particles with hadronic matter which makes strangeness production in heavy-ion collisions very different from that in elementary interactions. We show how different strange particle observables can be used to study the different facets of this interaction (production, rescattering and potential interaction) which finally merge into a comprehensive understanding of these interactions. We identify those observables which allow for studying (almost) exclusively one of these processes to show how future high precision experiments can improve our quantitative understanding. Finally, we discuss how the K+ multipl...

Hartnack, Christoph; Leifels, Yvonne; Bratkovskaya, Elena L; Aichelin, Jrg

2011-01-01T23:59:59.000Z

284

Dynamic Stabilization of the Ablative Rayleigh-Taylor Instability for Heavy Ion Fusion  

SciTech Connect

Dynamic stabilization of the ablative Rayleigh-Taylor instability of a heavy ion fusion target induced by a beam wobbling system is studied. Using a sharp-boundary model and Courant-Synder theory, it is shown, with an appropriately chosen modulation waveform, that the instability can be sta- bilized in certain parameter regimes. It is found that the stabilization e ect has a strong dependence on the modulation frequency and the waveform. Modulation with frequency comparable to the instability growth rate is the most e ective in terms of stabilizing the instability. A modulation with two frequency components can result in a reduction of the growth rate larger than the sum of that due to the two components when applied separately.

Hong Qin, Ronald C. Davidson and B. Grant Logan

2012-10-04T23:59:59.000Z

285

Energy loss in high energy heavy ion collisions from the Hydro+Jet model  

E-Print Network (OSTI)

We investigate the effect of energy loss of jets in high energy heavy ion collisions by using a full three-dimensional space-time evolution of a fluid combined with (mini-)jets that are explicitly evolved in space-time. In order to fit the pi^0 data for the Au+Au collisions at sqrt(s_{NN}) = 130 GeV, the space-time averaged energy loss dE/dx(tau energy loss occurs at the very early time less than 2 fm/c in the QGP phase and that energy loss in the mixed phase is negligible within our parameterization for jet energy loss. This is a consequence of strong expansion of the system.

Hirano, T; Hirano, Tetsufumi; Nara, Yasushi

2002-01-01T23:59:59.000Z

286

ACE/SWICS OBSERVATIONS OF HEAVY ION DROPOUTS WITHIN THE SOLAR WIND  

SciTech Connect

We present the first in situ observations of heavy ion dropouts within the slow solar wind, observed for select elements ranging from helium to iron. For iron, these dropouts manifest themselves as depletions of the Fe/H ratio by factors up to {approx}25. The events often exhibit mass-dependent fractionation and are contained in slow, unsteady wind found within a few days from known stream interfaces. We propose that such dropouts are evidence of gravitational settling within large coronal loops, which later undergo interchange reconnection and become source regions of slow, unsteady wind. Previously, spectroscopic studies by Raymond et al. in 1997 (and later Feldman et al. in 1999) have yielded strong evidence for gravitational settling within these loops. However, their expected in situ signature plasma with heavy elements fractionated by mass was not observed prior to this study. Using data from the SWICS instrument on board the Advanced Composition Explorer (ACE), we investigate the composition of the solar wind within these dropouts and explore long term trends over most of a solar cycle.

Weberg, Micah J. [PhD Candidate in Space and Planetary Physics, 2435 Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States); Zurbuchen, Thomas H. [Professor, Space Science and Aerospace Engineering, Associate Dean for Entrepreneurship, 2429 Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States); Lepri, Susan T., E-mail: mjweberg@umich.edu, E-mail: thomasz@umich.edu, E-mail: slepri@umich.edu [Associate Research Scientist, 2417 Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States)

2012-11-20T23:59:59.000Z

287

A systematic study of actinide production from the interactions of heavy ions with sup 248 Cm  

Science Conference Proceedings (OSTI)

Production cross sections for heavy actinides produced from the interactions of {sup 12}C, {sup 31}P, {sup 40}Ar, and {sup 44}Ca ions with {sup 248}Cm were measured at energies ranging from 0.98 to 1.35 X Coulomb barrier. The recoiling reaction products were collected in copper or gold catcher foils located near the {sup 248}Cm target. Separate fractions of Bk, Cf, Es, Fm, and Md were obtained from a radiochemical separation procedure. For the {sup 12}C system, a He/KCl jet was used to transport the recoiling No activities of interest to a rotating wheel system. The isotopic distributions of the actinide products were found to be essentially symmetric about the maximum with full-widths-at-half-maximum of approximately 2.5 mass units. Isotopic distributions of the {sup 12}C, {sup 31}P, {sup 40}Ar, and {sup 44}Ca systems were found to be very similar to the {sup 40,48}Ca systems studied previously. The maxima of the isotopic distributions generally occurred for those reaction channels which involved the exchange of the fewest number of nucleons between the target and projectile for which the calculated excitation energy was a positive quantity. Additionally, the maxima of the excitation functions occurred at those projectile energies which were consistent with the calculated reaction barriers based upon a binary reaction mechanism. The experimental data from the four systems investigated were compared to several models of heavy ion interactions including a damped reaction mechanism, compound nucleus formation and subsequent particle evaporation, and classical partial wave calculations for binary systems.

Leyba, J.D.

1990-09-07T23:59:59.000Z

288

Relics of Minijets amid Anisotropic Flows in High-energy Heavy-ion Collisions  

E-Print Network (OSTI)

Two dimensional low-$p_T$ dihadron correlations in azimuthal angle $\\phi$ and pseudo-rapidity $\\eta$ in high-energy heavy-ion collisions are investigated within both the HIJING Monte Carlo model and an event-by-event (3+1)D ideal hydrodynamic model. Without final-state interaction and collective expansion, dihadron correlations from HIJING simulations have a typical structure from minijets that contains a near-side two-dimensional peak and an away-side ridge along the $\\eta$-direction. In contrast, event-by-event (3+1)D ideal hydrodynamic simulations with fluctuating initial conditions from the HIJING+AMPT model produce a strong dihadron correlation that has an away-side as well as a near-side ridge. Relics of intrinsic dihadron correlation from minijets in the initial conditions still remain as superimposed on the two ridges. By varying initial conditions from HIJING+AMPT, we study effects of minijets, non-vanishing initial flow and longitudinal fluctuation on the final state dihadron correlations. With a large rapidity gap, one can exclude near-side correlations from minijet relics and dihadron correlations can be described by the superposition of harmonic flows up to the 6th order. When long-range correlations with a large rapidity gap are subtracted from short-range correlations with a small rapidity gap, the remaining near-side dihadron correlations result solely from relics of minijets. Low transverse momentum hadron yields per trigger ($p_T^{\\rm trig} <4$ GeV/$c$, $p_T^{\\rm asso}<2$ GeV/$c$) in central heavy-ion collisions are significantly enhanced over that in p+p collisions while widths in azimuthal angle remain the same, in qualitative agreement with experimental data.

Longgang Pang; Qun Wang; Xin-Nian Wang

2013-09-26T23:59:59.000Z

289

Integrated Experimental and Computational Approach to Understand the Effects of Heavy Ion Radiation on Skin Homeostasis.  

SciTech Connect

The effects of low dose high linear energy transfer (LET) radiation on human health are of concern for both space and clinical exposures. As epidemiological data for such radiation exposures are scarce for making relevant predictions, we need to understand the mechanism of response especially in normal tissues. Our objective here is to understand the effects of heavy ion radiation on tissue homeostasis in a realistic model system. Towards this end, we exposed an in vitro three dimensional skin equivalent to low fluences of Neon (Ne) ions (300 MeV/u), and determined the differentiation profile as a function of time following exposure using immunohistochemistry. We found that Ne ion exposures resulted in transient increases in the tissue regions expressing the differentiation markers keratin 10, and filaggrin, and more subtle time-dependent effects on the number of basal cells in the epidermis. We analyzed the data using a mathematical model of the skin equivalent, to quantify the effect of radiation on cell proliferation and differentiation. The agent-based mathematical model for the epidermal layer treats the epidermis as a collection of heterogeneous cell types with different proliferation/differentiation properties. We obtained model parameters from the literature where available, and calibrated the unknown parameters to match the observed properties in unirradiated skin. We then used the model to rigorously examine alternate hypotheses regarding the effects of high LET radiation on the tissue. Our analysis indicates that Ne ion exposures induce rapid, but transient, changes in cell division, differentiation and proliferation. We have validated the modeling results by histology and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The integrated approach presented here can be used as a general framework to understand the responses of multicellular systems, and can be adapted to other epithelial tissues.

von Neubeck, Claere; Shankaran, Harish; Geniza, Matthew; Kauer, Paula M.; Robinson, Robert J.; Chrisler, William B.; Sowa, Marianne B.

2013-08-08T23:59:59.000Z

290

Study of heavy ion induced fission fragment angular and mass distribution at near and sub-coulomb barrier energies  

E-Print Network (OSTI)

The thesis presents investigations on the angular and mass distribution of fission fragments on heavy ion induced fission reactions. The present investigations address current issues in heavy ion induced fission reactions like finding the optimum entrance channel for the synthesis of super heavy elements (SHE). A double arm time of flight spectrometer over long flight path was used to measure the precise masses of complementary fission fragments. Necessary large area position sensitive gas detectors, the method of experiments and data analysis were developed. The first string of measurements were for a spherical target (209^Bi) with oxygen and fluorine projectiles. The next series of experiments were done using a deformed target (232^Th) with fluorine, oxygen and carbon projectiles.

T. K. Ghosh

2005-08-10T23:59:59.000Z

291

Development of a Micromegas TPC for Low Energy Heavy Ions Measurement for Nuclear Fission and Astrophysics Applications  

SciTech Connect

Time Projection Chambers are widely used since many years for tracking and identification of charged particles in high energy physics. We present a new R and D project to investigate the feasibility of a Micromegas TPC for low energy heavy ions detection. Two physics cases are relevant for this project. The first is the study of the nuclear fission of actinides by measuring the fission fragments properties (mass, nuclear charge, kinetic energy) that will be performed at different installations and in particular at the NFS facility to be built in the framework of the SPIRAL2 project in GANIL. The second physics case is the study of heavy ion reactions, like ({alpha},{gamma}), ({alpha},p), ({alpha},n) and all the inverse reactions in the energy range between 1.5 and 3 AMeV using both stable and radioactive beams. These reactions have a key role in p process in nuclear astrophysics to explain the synthesis of heavy proton-rich nuclei. Within the project, a large effort is devoted to Monte-Carlo simulations and a detailed benchmark of different simulation codes on the energy loss and range in gas of heavy ions at low energy has been performed. A new approach for simulating the ion charge state evolution in GEANT4 is also presented. Finally, preliminary results of an experimental test campaign on prototype are discussed.

Panebianco, S.; Dore, D.; Giomataris, I.; Papaevangelou, Th.; Vernoud, L. [CEA, Centre de Saclay, Institut de Recherche sur les lois Fondamentales de l' Univers, 91191 Gif-sur-Yvette (France); Axiotis, M.; Fanourakis, G.; Geralis, Th.; Harissopoulos, S.; Lagoyannis, A. [Institute of Nuclear Physics, NCRS ' Demokritos' , 15310 Aghia Paraskevi, Athens (Greece)

2011-10-28T23:59:59.000Z

292

Simulation and Analysis of Human Phantoms Exposed to Heavy Charged Particle Irradiations Using the Particle and Heavy Ion Transport System (PHITS)  

E-Print Network (OSTI)

Anthropomorphic phantoms are commonly used for testing radiation fields without the need to expose human subjects. One of the most widely known is RANDO phantom. This phantom is used primarily for medical X-ray applications, but a similar design known as "MATROSHKA" is now being used for space research and exposed to heavy ion irradiations from the Galactic environment. Since the radiation field in the phantom should respond in a similar manner to how it would act in human tissues and organs under an irradiation, the tissue substitute chosen for soft tissue and the level of complexity of the entire phantom are crucial issues. The phantoms, and the materials used to create them, were developed mainly for photon irradiations and have not been heavily tested under the conditions of heavy ion exposures found in the space environment or external radiotherapy. The Particle and Heavy-Ion Transport code System (PHITS) was used to test the phantoms and their materials for their potential as human surrogates for heavy ion irradiation. Stopping powers and depth-dose distributions of heavy charged particles (HCPs) important to space research and medical applications were first used in the simulations to test the suitability of current soft tissue substitutes. A detailed computational anthropomorphic phantom was then developed where tissue substitutes and ICRU-44 tissue could be interchanged to verify the validation of the soft tissue substitutes and and determine the required level of complexity of the entire phantom needed to achieve a specified precision as a replacement of the human body. The materials tested were common soft tissue substitutes in use and the materials which had a potential for the soft tissue substitute. Ceric sulfate dosimeter solution was closest to ICRU-44 tissue; however, it was not appropriate as the phantom material because it was a solution. A150 plastic, ED4C (fhw), Nylon (Du Pont Elvamide 8062), RM/SR4, Temex, and RW-2 were within 1% of the mean normalized difference of mass stopping powers (or stopping powers for RW-2) when compared to the ICRU-44 tissue, and their depth-dose distributions were close; therefore, they were the most suitable among the remaining solid materials. Overall, the soft tissue substitutes which were within 1% of ICRU-44 tissue in terms of stopping power produced reasonable results with respect to organ dose in the developed phantom. RM/SR4 is the best anthropomorphic phantom soft tissue substitute because it has similar interaction properties and identical density with ICRU-44 tissue and it is a rigid solid polymer giving practical advantages in manufacture of real phantoms.

Lee, Dongyoul

2011-12-01T23:59:59.000Z

293

A very thin havar film vacuum window for heavy ions to perform radiobiology studies at the BNL Tandem  

Science Conference Proceedings (OSTI)

Heavy ion beams from the BNL Tandem Van de Graaff accelerators will be made available for radiobiology studies on cell cultures. Beam energy losses need to be minimized both in the vacuum window and in the air in order to achieve the ranges required for the cells to be studied. This is particularly challenging for ions heavier than iron. The design is presented of a 0.4-inch diameter Havar film window that will satisfy these requirements. Films as thin as 80 microinches were successfully pressure tested. The final thickness to be used may be slightly larger to help in achieving pin hole free windows. We discuss design considerations and present pressure and vacuum test results as well as tests with heavy ion beams.

Thieberger, P.; Abendroth, H.; Alessi, J.; Cannizzo, L.; Carlson, C.; Gustavsson, A.; Minty, M.; Snydstrup, L.

2011-03-28T23:59:59.000Z

294

Incorporation of the effect of the composite electric fields of molecular ions as a simulation tool for biological damage due to heavy ion irradiation II  

SciTech Connect

This paper presents a theoretical study of the DNA damage due to the effect of the composite electric fields of H{sub 2}O{sup +} ions produced from the irradiation of a heavy ion onto a cell. It is found that a much larger number of electrons, which are produced from electron impact ionization, is trapped near the track of an incident ion in the case of C{sup 6+} ion irradiation with the energy of 3 MeV/u than that of proton irradiation. Therefore, the irradiation of carbon ions may produce a larger number of cluster DNA damage than that in the irradiation of protons. This may lead to the understanding of relative biological effectiveness (RBE).

Moribayashi, Kengo [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1-7, Umemidai, Kizugawa-city, 619-0215 (Japan) and Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe City, 610-0394 (Japan)

2012-07-11T23:59:59.000Z

295

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields  

E-Print Network (OSTI)

of positive and negative chlorine ions, with only a smalltest case. We chose chlorine because, unlike iodine orTwo sets of experiments with chlorine using different RF ion

Kwan, J.W.

2008-01-01T23:59:59.000Z

296

Effect of nonthermal electrons on the propagation characteristics and stability of two-dimensional nonlinear electrostatic coherent structures in relativistic electron positron ion plasmas  

SciTech Connect

Two-dimensional propagation of nonlinear ion acoustic shock and solitary waves in an unmagnetized plasma consisting of nonthermal electrons, Boltzmannian positrons, and singly charged hot ions streaming with relativistic velocities are investigated. The system of fluid equations is reduced to Kadomtsev-Petviashvili-Burgers and Kadomtsev-Petviashvili (KP) equations in the limit of small amplitude perturbation. The dependence of the ion acoustic shock and solitary waves on various plasma parameters are explored in detail. Interestingly, it is observed that increasing the nonthermal electron population increases the wave dispersion which enervates the strength of the ion acoustic shock wave; however, the same effect leads to an enhancement of the soliton amplitude due to the absence of dissipation in the KP equation. The present investigation may be useful to understand the two-dimensional propagation characteristics of small but finite amplitude localized shock and solitary structures in planetary magnetospheres and auroral plasmas where nonthermal populations of electrons have been observed by several satellite missions.

Masood, W. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Rizvi, H. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan)

2011-06-15T23:59:59.000Z

297

Jet quenching in heavy-ion collisions at LHC with CMS detector  

E-Print Network (OSTI)

The collision of highly relativistic nuclei can produce a volume of high energy density which can be used to learn about the behavior of quantum chromodynamics (QCD) at extreme conditions, such as those of the universe at ...

Yilmaz, Yetkin

2013-01-01T23:59:59.000Z

298

Simulation of measuring bottom quark flow in heavy ion collisions using the CMS detector  

E-Print Network (OSTI)

In this thesis, I carried out a simulation study to characterize the measurement of bottom quark flow in relativistic Pb+Pb collisions using the Compact Muon Solenoid experiment. The Hydjet event generator is used to produce ...

Franke, Arthur James

2007-01-01T23:59:59.000Z

299

System Size, Energy and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy Ion Collisions  

E-Print Network (OSTI)

We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, \\sqrtsnn = 22.4, 62.4 and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. Making a global comparison of Cu+Cu and Au+Au results, we find that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same Npart/2A value rather than the same Npart value. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.

B. Alver; B. B. Back; M. D. Baker; M. Ballintijn; D. S. Barton; R. R. Betts; R. Bindel; W. Busza; Z. Chai; V. Chetluru; E. Garca; T. Gburek; K. Gulbrandsen; J. Hamblen; I. Harnarine; C. Henderson; D. J. Hofman; R. S. Hollis; R. Ho?y?ski; B. Holzman; A. Iordanova; J. L. Kane; P. Kulinich; C. M. Kuo; W. Li; W. T. Lin; C. Loizides; S. Manly; A. C. Mignerey; R. Nouicer; A. Olszewski; R. Pak; C. Reed; E. Richardson; C. Roland; G. Roland; J. Sagerer; I. Sedykh; C. E. Smith; M. A. Stankiewicz; P. Steinberg; G. S. F. Stephans; A. Sukhanov; A. Szostak; M. B. Tonjes; A. Trzupek; G. J. van Nieuwenhuizen; S. S. Vaurynovich; R. Verdier; G. I. Veres; P. Walters; E. Wenger; D. Willhelm; F. L. H. Wolfs; B. Wosiek; K. Wo?niak; S. Wyngaardt; B. Wys?ouch

2007-09-25T23:59:59.000Z

300

Properties of baryonic, electric and strangeness chemical potentials and some of their consequences in relativistic heavy ion collisions  

E-Print Network (OSTI)

Analytic expressions are given for the baryonic, electric and strangeness chemical potentials which explicitly show the importance of various terms. Simple scaling relations connecting these chemical potentials are found. Applications to particle ratios and to fluctuations and related thermal properties such as the isothermal compressibility kappaT are illustrated. A possible divergence of kappaT is discussed.

Aram Z. Mekjian

2007-12-07T23:59:59.000Z

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301

Properties of baryonic, electric and strangeness chemical potentials and some of their consequences in relativistic heavy ion collisions  

E-Print Network (OSTI)

Analytic expressions are given for the baryonic, electric and strangeness chemical potentials which explicitly show the importance of various terms. Simple scaling relations connecting these chemical potentials are found. Applications to particle ratios and to fluctuations and related thermal properties such as the isothermal compressibility kappaT are illustrated. A possible divergence of kappaT is discussed.

Mekjian, Aram Z

2007-01-01T23:59:59.000Z

302

RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN  

SciTech Connect

Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; DOttavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

2010-05-23T23:59:59.000Z

303

RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN  

Science Conference Proceedings (OSTI)

Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; DOttavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

2010-05-23T23:59:59.000Z

304

Effects of Minijets on Common Observables in Heavy-Ion Collisions with Uncommon Implications  

E-Print Network (OSTI)

In this brief review of the observable effects of minijets in heavy-ion collisions the main points emphasized are that the quadruple moment $v_2(p_T,b)$ and the hadronic ($\\pi$ and $p$) spectra at low $p_T$ can both be reproduced by minijet contributions to the recombination of thermal and shower partons. Without using hydrodynamics the minijet approach does not trace the evolution of the expanding system. The thermal distribution of the medium partons at the time of hadronization is assumed, but rapid thermalization initially is not required so as to allow minijets to leave their footprints on the system in the final state. Azimuthal anisotropy due to minijets is directly calculated in the momentum space without any fluid assumption relating the spatial eccentricity to $v_2$. There are no more parameters used, compared to the hydro approach in fitting the data on $v_2$ and $p_T$ spectra. Thus both approaches satisfy the sufficiency condition for a viable description of the dynamical process involved.

Rudolph C. Hwa

2013-02-14T23:59:59.000Z

305

Detection Efficiency of a ToF Spectrometer from Heavy-Ion Elastic Recoil Detection  

SciTech Connect

The detection efficiency of a time-of-flight system based on two micro-channel plates (MCP) time zero detectors plus a conventional silicon surface barrier detector was obtained from heavy ion elastic recoil measurements (this ToF spectrometer is mainly devoted to measurements of total fusion cross section of weakly bound projectiles on different mass-targets systems). In this work we have used beams of {sup 7}Li, {sup 16}O, {sup 32}S and {sup 35}Cl to study the mass region of interest for its application to measurements fusion cross sections in the {sup 6,7}Li+{sup 27}Al systems at energies around and above the Coulomb barrier (0.8V{sub B{<=}}E{<=}2.0V{sub B}). As the efficiency of a ToF spectrometer is strongly dependent on the energy and mass of the detected particles, we have covered a wide range of the scattered particle energies with a high degree of accuracy at the lowest energies. The different experimental efficiency curves obtained in that way were compared with theoretical electronic stopping power curves on carbon foils and were applied.

Barbara, E. de; Marti, G. V.; Capurro, O. A.; Fimiani, L.; Mingolla, M. G. [Laboratorio ANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, B1650KNA Partido de San Martin, Provincia de Buenos Aires (Argentina); Negri, A. E.; Arazi, A.; Figueira, J. M.; Pacheco, A. J.; Martinez Heimann, D.; Carnelli, P. F. F. [Laboratorio ANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, B1650KNA Partido de San Martin, Provincia de Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Ciudad Autonoma de Buenos Aires (Argentina); Fernandez Niello, J. O. [Laboratorio ANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, B1650KNA Partido de San Martin, Provincia de Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Ciudad Autonoma de Buenos Aires (Argentina); Universidad Nacional de General San Martin, Ayacucho 2197, B1650BWA Partido de San Martin, Provincia de Buenos Aires (Argentina)

2010-08-04T23:59:59.000Z

306

Photon HBT interferometry for non-central heavy-ion collisions  

E-Print Network (OSTI)

Currently, the only known way to obtain experimental information about the space-time structure of a heavy-ion collision is through 2-particle momentum correlations. Azimuthally sensitive HBT interferometry (Hanbury Brown-Twiss intensity interferometry) can complement elliptic flow measurements by constraining the spatial deformation of the source and its time evolution. Performing these measurements on photons allows us to access the fireball evolution at earlier times than with hadrons. Using ideal hydrodynamics to model the space-time evolution of the collision fireball, we explore theoretically various aspects of 2-photon intensity interferometry with transverse momenta up to 2 GeV, in particular the azimuthal angle dependence of the HBT radii in non-central collisions. We highlight the dual nature of thermal photon emission, in both central and non-central collisions, resulting from the superposition of QGP and hadron resonance gas photon production. This signature is present in both the thermal photon source function and the HBT radii extracted from Gaussian fits of the 2-photon correlation function.

Evan Frodermann; Ulrich Heinz

2009-07-07T23:59:59.000Z

307

Energy deposition in hard dihadron triggered events in heavy-ion collisions  

E-Print Network (OSTI)

The experimental observation of hadrons correlated back-to-back with a (semi-)hard trigger in heavy ion collisions has revealed a splitting of the away side correlation structure in a low to intermediate transverse momentum (P_T) regime. This is consistent with the assumption that energy deposited by the away side parton into the bulk medium produced in the collision excites a sonic shockwave (a Mach cone) which leads to away side correlation strength at large angles. A prediction following from assuming such a hydrodynamical origin of the correlation structure is that there is a sizeable elongation of the shockwave in rapidity due to the longitudinal expansion of the bulk medium. Using a single hadron trigger, this cannot be observed due to the unconstrained rapidity of the away side parton. Using a dihadron trigger, the rapidity of the away side parton can be substantially constrained and the longitudinal structure of the away side correlation becomes accessible. However, in such events several effects occur which change the correlation structure substantially: There is not only a sizeable contribution due to the fragmentation of the emerging away side parton, but also a systematic bias towards small energy deposition into the medium and hence a weak shockwave. In this paper, both effects are addressed.

Thorsten Renk

2008-04-08T23:59:59.000Z

308

Adiabatic Heavy Ion Fusion Potentials for Fusion at Deep Sub-barrier Energies  

E-Print Network (OSTI)

The fusion cross sections from well above barrier to extreme sub-barrier energies have been analysed using the energy (E) and angular momentum (L) dependent barrier penetration model ({\\small{ELDBPM}}). From this analysis, the adiabatic limits of fusion barriers have been determined for a wide range of heavy ion systems. The empirical prescription of Wilzynska and Wilzynski has been used with modified radius parameter and surface tension coefficient values consistent with the parameterization of the nuclear masses. The adiabatic fusion barriers calculated from this prescription are in good agreement with the adiabatic barriers deduced from {\\small{ELDBPM}} fits to fusion data. The nuclear potential diffuseness is larger at adiabatic limit, resulting in a lower $\\hbar\\omega$ leading to increase of "logarithmic slope" observed at energies well below the barrier. The effective fusion barrier radius and curvature values are anomalously smaller than the predictions of known empirical prescriptions. A detailed comparison of the systematics of fusion barrier with and without L-dependence has been presented.

S. V. S. Sastry; S. Kailas; A. K. Mohanty; A. Saxena

2003-11-12T23:59:59.000Z

309

Isospin-dependent pion in-medium effects on the charged-pion ratio in heavy ion collisions  

E-Print Network (OSTI)

Using results from the chiral perturbation theory for the s-wave interaction and the Delta-resonance model for the p-wave interaction of pions with nucleons, we evaluated the spectral functions of pions in asymmetric nuclear matter with unequal proton and neutron densities. We find that in hot dense neutron-rich matter the strength of the spectral function of positively charged pions at low energies is somewhat larger than that of negatively charged pions. In a thermal model, this isospin-dependent effect slightly reduces the ratio of negatively charged to positively charged pions that are produced in heavy ion collisions induced by radioactive beams. The relevance of our results to the determination of the nuclear symmetry energy from the measured ratio of negatively to positively charged pions produced in heavy ion collisions is discussed.

Xu, Jun; Ko, Che Ming; Oh, Yongseok.

2010-01-01T23:59:59.000Z

310

Heavy ion SEU immunity of a GaAs complementary HIGFET circuit fabricated on a low temperature grown buffer layer  

SciTech Connect

The authors compare dynamic SEU characteristics of GaAs complementary HIGFET devices fabricated on conventional semi-insulating substrates versus low temperature grown GaAs (LT GaAs) buffer layers. Heavy ion test results on shift register and flip-flop devices from the same process lot demonstrate that the LT GaAs layer provides immunity from upsets, even at an LET value of 90 MeV {center_dot} cm{sup 2}/mg. This result is also consistent with pulsed laser measurements performed on the same flip-flop circuits used in the ion test.

Marshall, P.W.; Weatherford, T.; Carts, M. [Naval Research Lab., Washington, DC (United States)]|[SFA, Inc., Landover, MD (United States); Dale, C.J.; McMorrow, D. [Naval Research Lab., Washington, DC (United States); Peczalski, A.; Baier, S.; Nohava, J.; Skogen, J. [Honeywell Systems and Research Center, Bloomington, MN (United States)

1995-12-01T23:59:59.000Z

311

Bound-free pair production cross section in heavy-ion colliders from the equivalent photon approach  

E-Print Network (OSTI)

Exact calculations of the electron-positron pair production by a single photon in the Coulomb field of a nucleus with simultaneous capture of the electron into the K-shell are discussed for different nuclear charges. Using the equivalent photon method of Weizsaecker and Williams, a simple expression for the bound-free production of electron-positron pairs by colliding very-high-energy fully stripped heavy ions is derived for nuclei of arbitrary charge.

Andreas Aste

2007-10-23T23:59:59.000Z

312

Dependence of asymmetries for charge distribution with respect to the reaction plane on initial energy in heavy ion collisions  

E-Print Network (OSTI)

In the paper two combinations of correlators are defined in order to investigate the evolution of possible $\\mathcal{P/CP}$ invariance violation in strong interactions with initial energy for heavy ion collisions. These combinations correspond to absolute and relative asymmetry of distribution of electrically charge particles with respect to the reaction plane in heavy ion collisions. Energy dependence of the parameters was derived from data of STAR and ALICE experiments. Significant decreasing both absolute and relative asymmetry is observed at energies $\\sqrt{s_{NN}} < 20$ GeV. This feature agrees qualitatively with other results of stage-I beam energy scan program in STAR experiment. General behavior of dependence of absolute asymmetry on initial energy agree reasonably with behavior of similar dependence of Chern -- Simons diffusion rate calculated at different values of external Abelian magnetic field. The observed behavior of understudying parameters vs energy can be considered as indication on possible transition to predominance of hadronic states over quark-gluon degrees of freedom in the mixed phase created in heavy ion collisions at intermediate energies.

V. A. Okorokov

2013-01-05T23:59:59.000Z

313

A new solar flare heavy ion model and its implementation through MACREE, an improved modeling tool to calculate single event effect rates in space  

Science Conference Proceedings (OSTI)

A new solar flare heavy ion model has been developed to support Space Station Single Event Effects (SEE) evaluations. It shows good agreement with previous flare data, and is implemented through an improved version of the CREME code.

Majewski, P.P.; Normand, E.; Oberg, D.L. [Boeing Defense and Space Group, Seattle, WA (United States)] [Boeing Defense and Space Group, Seattle, WA (United States)

1995-12-01T23:59:59.000Z

314

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields  

E-Print Network (OSTI)

pos itive and ne gative chlorine i ons, w ith onl y a s malltest case. W e ch ose chlorine b ecause, u nlike iodine o rsets of e xperiments with chlorine using different RF ion s

Grisham, L. R.

2010-01-01T23:59:59.000Z

315

Relativistic many-body calculations of lifetimes, rates, and line strengths of multipole transitions between 3l-1 4l' states in Ni-like ions  

Science Conference Proceedings (OSTI)

Transition rates and line strengths are calculated for electric-multipole (E2 and E3) and magnetic-multipole (M1, M2, and M3) transitions between 3s{sup 2}3p{sup 6}3d{sup 10}, 3s{sup 2}3p{sup 6}3d{sup 9}4l, 3s{sup 2}3p{sup 5}3d{sup 10}4l, and 3s3p{sup 6}3d{sup 10}4l states (with 4l = 4s, 4p, 4d, and 4f) in Ni-like ions with the nuclear charges ranging from Z = 34 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded multipole matrix elements. Transition energies used in the calculation of line strengths and transition rates are from second-order RMBPT. Lifetimes of the 3s{sup 2}3p{sup 6}3d{sup 9}4s levels are given for Z = 34-100. Taking into account that calculations were performed in a very broad range of Z, most of the data are presented in graphs as Z-dependencies. The full set of data is given only for Ni-like W ion. In addition, we also give complete results for the 3d4s{sup 3}D{sub 2}-3d4s {sup 3}D{sub 1} magnetic-dipole transition, as the transition may be observed in future experiments, which measure both transition energies and radiative rates. These atomic data are important in the modeling of radiation spectra from Ni-like multiply-charged ions generated in electron beam ion trap experiments as well as for laboratory plasma diagnostics including fusion research.

Safronova, U I; Safronova, A S; Beiersdorfer, P

2007-10-08T23:59:59.000Z

316

A 16 MeV/nucleon cocktail for heavy ion testing  

E-Print Network (OSTI)

early 1990s, a second-generation ion source was built at thethe first third generation ECR ion source being built in thenewest generations of chips. Once the VENUS ion source is

2004-01-01T23:59:59.000Z

317

SPALLATION-FISSION COMPETITION IN ASTATINE COMPOUND NUCLEI FORMED BY HEAVY-ION BOMBARDMENT  

E-Print Network (OSTI)

Effect of Angular Momentum on Fission Probability (Thesis),R. Vandenbosch, Nuclear Fission, to be published in Nuclearfrom Heavy-lon-Induced Fission (Thesis), Lawrence Radiation

Thomas, T. Darrah; Gordon, Glen E.; Latimer, Robert M.; Seaborg, Glenn T.

2008-01-01T23:59:59.000Z

318

Relativistic many-body calculation of energies, oscillator strengths, transition rates, lifetimes, polarizabilities, and quadrupole moment of Fr-like Th IV ion  

E-Print Network (OSTI)

Atomic properties of the 24 low-lying ns, np, nd, nf, and ng states in Th IV ion are calculated using the high-precision relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Fock wave functions are included to all orders of perturbation theory. Recommended values are provided for a large number of electric-dipole matrix elements, oscillator strengths, transition rates, and lifetimes. Scalar polarizabilities of the ground and six excited states (5f_j, 6d_j, 7p_j, and 7s), and tensor polarizabilities of the 5f_j, 6d_j, 7p_{3/2} states of Th IV are evaluated. The uncertainties of the recommended values are estimated. These calculations provide recommended values critically evaluated for their accuracy for a number of Th IV atomic properties for use in theoretical modeling as well as planning and analysis of various experiments including development of ultra precise nuclear clock and RESIS studies of actinide ions

M. S. Safronova; U. I. Safronova

2013-03-31T23:59:59.000Z

319

Relativistic many-body calculation of energies, oscillator strengths, transition rates, lifetimes, polarizabilities, and quadrupole moment of Fr-like Th IV ion  

E-Print Network (OSTI)

Atomic properties of the 24 low-lying ns, np, nd, nf, and ng states in Th IV ion are calculated using the high-precision relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Fock wave functions are included to all orders of perturbation theory. Recommended values are provided for a large number of electric-dipole matrix elements, oscillator strengths, transition rates, and lifetimes. Scalar polarizabilities of the ground and six excited states (5f_j, 6d_j, 7p_j, and 7s), and tensor polarizabilities of the 5f_j, 6d_j, 7p_{3/2} states of Th IV are evaluated. The uncertainties of the recommended values are estimated. These calculations provide recommended values critically evaluated for their accuracy for a number of Th IV atomic properties for use in theoretical modeling as well as planning and analysis of various experiments including development of ultra precise nuclear clock and RESIS studies of actinide ions

Safronova, M S

2013-01-01T23:59:59.000Z

320

Solenoid transport of a heavy ion beam for warm dense matterstudies and inertial confinement fusion  

SciTech Connect

From February to July 2006, I have been doing research as a guest at Lawrence Berkeley National Laboratory (LBNL), in the Heavy Ion Fusion group. This internship, which counts as one semester in my master's program in France, I was very pleased to do it in a field that I consider has the beauty of fundamental physics, and at the same time the special appeal of a quest for a long-term and environmentally-respectful energy source. During my stay at LBNL, I have been involved in three projects, all of them related to Neutralized Drift Compression Experiment (NDCX). The first one, experimental and analytical, has consisted in measuring the effects of the eddy currents induced by the pulsed magnets in the conducting plates of the source and diagnostic chambers of the Solenoid Transport Experiment (STX, which is a subset of NDCX). We have modeled the effect and run finite-element simulations that have reproduced the perturbation to the field. Then, we have modified WARP, the Particle-In-Cell code used to model the whole experiment, in order to import realistic fields including the eddy current effects and some details of each magnet. The second project has been to take part in a campaign of WARP simulations of the same experiment to understand the leakage of electrons that was observed in the experiment as a consequence to some diagnostics and the failure of the electrostatic electron trap. The simulations have shown qualitative agreement with the measured phenomena, but are still in progress. The third project, rather theoretical, has been related to the upcoming target experiment of a thin aluminum foil heated by a beam to the 1-eV range. At the beginning I helped by analyzing simulations of the hydrodynamic expansion and cooling of the heated material. But, progressively, my work turned into making estimates for the nature of the liquid/vapor two-phase flow. In particular, I have been working on criteria and models to predict the formation of droplets, their size, and their partial or total evaporation in the expanding flow.

Armijo, Julien

2006-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
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321

Non-collective excitations in low-energy heavy-ion reactions: applicability of the random-matrix model  

E-Print Network (OSTI)

We investigate the applicability of a random-matrix model to the description of non-collective excitations in heavy-ion reactions around the Coulomb barrier. To this end, we study fusion in the reaction $^{16}$O + $^{208}$Pb, taking account of the known non-collective excitations in the $^{208}$Pb nucleus. We show that the random-matrix model for the corresponding couplings reproduces reasonably well the exact calculations, obtained using empirical deformation parameters. This implies that the model may provide a powerful method for systems in which the non-collective couplings are not so well known.

S. Yusa; K. Hagino; N. Rowley

2013-08-29T23:59:59.000Z

322

Status of Trapped-Ion Physics in Europe  

Science Conference Proceedings (OSTI)

... Innsbruck molecular ions spectroscopy K. Wendt Mainz heavy ions laser ion sources ... K. Wendt Mainz heavy ions laser ion sources W. Quint ...

2011-03-01T23:59:59.000Z

323

A Large-scale Relativistic Configuration-interaction Approach: Application to the 4s2 - 4s4p Transition Energies and E1 Rates for Zn-like Ions  

SciTech Connect

Relativistic configuration-interaction calculations of the 4s4p excitation energies and 4s{sup 2} - 4s4p E1 transitions for Zn-like ions from Z = 30 to 92 are shown. B-spline basis functions are used for these large-scale calculations. QED corrections to the excitation energies are also calculated. Results are in good agreement with other theories and with experiment, and demonstrate the utility of this method for high-precision atomic structure calculations not just for few-electron systems but also for large atomic systems such as Zn-like ions along the entire isoelectronic sequence.

Chen, M H; Cheng, K T

2009-08-28T23:59:59.000Z

324

Studies of heavy-ion reactions and transuranic nuclei. Progress report, September 1, 1992--August 31, 1993  

SciTech Connect

This report contain papers on the following topics: The Cold-Fusion Saga; Decay Patterns of Dysprosium Nuclei Produced in {sup 32}S + {sup 118,124}Sn Fusion Reactions; Unexpected Features of Reactions Between Very Heavy Ions at Intermediate Bombarding Energies; Correlations Between Neutrons and Charged Products from the Dissipative Reaction {sup 197}Au+{sup 208}Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction {sup 209}Bi+{sup 136}Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral {sup 209}Bi+{sup 136}Xe Collisions at E{sub lab}/A = 28.2 MeV; The Rochester 960-Liter Neutron Multiplicity Meter; A Simple Pulse Processing Concept for a Low-Cost Pulse-Shape-Based Particle Identification; A One-Transistor Preamplifier for PMT Anode Signals; A Five-Channel Multistop TDC/Event Handler for the SuperBall Neutron Multiplicity Meter; Construction of the SuperBall -- a 16,000-Liter Neutron Detector for Calorimetric Studies of Intermediate-Energy Heavy-Ion Reactions; A Computer Code for Light Detection Efficiency Calculations for Photo-multipliers of a Neutron Detector; Evaluation of Gd-Loaded Liquid Scintillators for the SuperBall Neutron Calorimeter; and Measurement of the Interaction of Cosmic-Ray {mu}{sup {minus}} with a Muon Telescope.

Schroeder, W.U.

1993-08-01T23:59:59.000Z

325

Experimental investigation and thermodynamic modeling of extraction of heavy metal ions from aqueous solutions by chelation in supercritical carbon dioxide  

E-Print Network (OSTI)

Wastewater streams containing heavy metals are common in industry. To prevent the contamination of clean water sources, the Clean Water Act specifies limits on the heavy metal concentrations of industrial waste water. This creates a strong need for developing cost effective and environmentally friendly metal removal technologies. Solvent extraction has been recognized as one of the best methods for removing metals from wastewater. Although the metals are easily removed, this process has two major disadvantages. First, the solvent/metal solution must be subsequently purified. Second, since the solvent may be miscible in the aqueous phase, the residual solvent must be removed from the water stream. These disadvantages can be eliminated by substituting conventional organic solvents with supercritical fluids. The main objective of this research has been to investigate the potential and feasibility of heavy metal ion extraction through chelation in supercritical CO2. Copper has been chosen as the model contaminant as it is frequently found in industrial waste streams. Different chelating agents have been tested to find the most appropriate one for copper. Analytical methods have been developed to quantify supercritical and aqueous phase compositions. Specifically, an Atomic Absorption Analyzer and a Gas Chromatograph have been employed. Copper ions have been successfully extracted up to 97% on different isotherms. Considering the phase equilibria and the thirteen reactions taking place in the system, a thermodynamic model has been developed. This model predicts the system pH which is a important factor in design of metal extraction units. With the model the efficiency of the extraction with different chelating agents at different temperatures and pressures is easily estimated. The model is also capable of calculating the concentrations of chemical species present in the system. This study proposed a novel and viable technique for the remediation of metal ions in waste water streams. In conjunction with the developed model the efficiency of this process for a specific industrial application can be accurately estimated. The results of this study demonstrate that this process is both environmentally friendly and economically feasible for wide spread industrial use.

Uyansoy, Hakki

1995-01-01T23:59:59.000Z

326

Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion  

DOE Green Energy (OSTI)

Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles close-in to the target (built-in as part of each target); (4) beam space charge-neutralization during both drift compression and final focus to target. Except for (1) and (2), these critical issues may be explored on existing heavy-ion storage ring accelerator facilities.

Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

1998-04-01T23:59:59.000Z

327

THE CLASSICAL-LIMIT S-MATRIX FOR HEAVY ION SCATTERING  

E-Print Network (OSTI)

probabilities are sensi nuclear interference ve to Coulomb-now feel the nuclear one would expect ve to the nuclearncl us ion a complex nuclear potential. ve using t integral

Donangelo, R.J.

2010-01-01T23:59:59.000Z

328

Dynamics in the production of superheavy nuclei in low-energy heavy-ion collisions  

E-Print Network (OSTI)

We present a review of the recent progress of theoretical models on the description of the formation of superheavy nuclei in collisions of heavy systems. Two sorts of reactions that are the fusion-evaporation mechanism and the massive damped collisions to produce superheavy nuclei are discussed. Problems and further improvements of the capture of colliding partners, the formation of compound nucleus and the de-excitation process are pointed out. Possible combinations in the synthesis of the gap of the cold fusion and $^{48}$Ca induced reactions are proposed by the calculations based on the dinuclear system model and also compared with other approaches. The synthesis of neutron-rich heavy isotopes near sub-shell closure N=162 via transfer reactions in the damped collisions of two actinides and the influence of shell closure on the production of heavy isotopes are investigated. Prospective possibility to reach superheavy nuclei near N=184 via neutron-rich radioactive beams of high intensity in the future is discussed.

Zhao-Qing Feng; Gen-Ming Jin; Jun-Qing Li

2011-05-26T23:59:59.000Z

329

Shear viscosity to entropy density ratio of a relativistic Hagedorn resonance gas  

E-Print Network (OSTI)

The new state of matter produced at Relativistic Heavy Ion Collider reveals a strongly coupled quark-gluon plasma with an extremely small shear viscosity to entropy density ratio eta/s. We calculate the eta/s of an equilibrated hadron matter characterized by a relativistic hadron resonance gas with a Hagedorn mass spectrum that grows exponentially with the hadron mass. We find with increase in temperature of the system the eta/s value decreases due to rapid increase in the multiplicity of massive resonances. In the vicinity of the critical temperature for deconfinement transition, the minimum value of eta/s in the Hagedorn resonance gas is found to be consistent with the current estimates for a strongly coupled quark-gluon plasma.

Subrata Pal

2010-01-11T23:59:59.000Z

330

Temperature determined by isobaric yield ratio in heavy-ion collisions  

E-Print Network (OSTI)

This work focuses on the study of temperature associated with the final heavy fragments in reactions induced by both the neutron-proton symmetric and the neutron-rich projectiles, and with incident energy ranges from 60$A$ MeV to 1$A$ GeV. Isobaric yield ratio (IYR) is used to determine the temperature of heavy fragments. Cross sections of measured fragment in reactions are analyzed, and a modified statistical abrasion-ablation (SAA) model is used to calculate the yield of fragment in 140$A$ MeV $^{64}$Ni + $^{9}$Be and 1$A$ GeV $^{136}$Xe + $^{208}$Pb reactions. Relatively low $T$ of heavy fragments are obtained in different reactions ($T$ ranges from 1 to 3MeV). $T$ is also found to depend on the neutron-richness of the projectile. The incident energy affects $T$ very little. $\\Delta\\mu/T$ (the ratio of the difference between the chemical potential of neutron and proton to temperature) is found to increase linearly as $N/Z$ of projectile increases. It is found that $T$ of the $^{48}$Ca reaction, for which IYRs are of $A<50$ isobars, is affected greatly by the temperature-corrected $\\Delta B(T)$. But $T$ of reactions using IYRs of heavier fragments are only slightly affected by the temperature-corrected $\\Delta B(T)$. The SAA model analysis gives a consistent overview of the results extracted in this work. $T$ from IYR, which is for secondary fragment, is different from that of the hot emitting source. $T$ and $\\Delta\\mu$ are essentially governed by the sequential decay process.

C. W. Ma; J. Pu; Y. G. Ma; R. Wada; S. S. Wang

2012-12-01T23:59:59.000Z

331

High intensity production of high and medium charge state uraniumand other heavy ion beams with VENUS  

SciTech Connect

The next generation, superconducting ECR ion source VENUS(Versatile ECR ion source for NUclear Science) started operation with 28GHzmicrowave heating in 2004. Since then it has produced world recordion beam intensities. For example, 2850 e mu A of O6+, 200 e mu A of U33+or U34+, and in respect to high charge state ions, 1 e mu A of Ar18+, 270e mu A of Ar16+, 28 e mu A of Xe35+ and 4.9 e mu A of U47+ have beenproduced. A brief overview of the latest developments leading to theserecord intensities is given and the production of high intensity uraniumbeams is discussed in more detail.

Leitner, Daniela; Galloway, Michelle L.; Loew, Timothy J.; Lyneis, Claude M.; Rodriguez, Ingrid Castro; Todd, Damon S.

2007-11-15T23:59:59.000Z

332

Probing High-Velocity Transient-Field Strength Using Heavy-ions Traversing Fe and Gd  

SciTech Connect

The transient field strength for {sup 76}Ge ions, passing through iron and gadolinium layers at velocities approxZv{sub 0}, has been measured. Although a sizeable value has been obtained for Gd, a vanishing strength has been observed in Fe.

Fiori, E.; Georgiev, G.; Cabaret, S.; Lozeva, R. [CSNSM, CNRS/IN2P3, Universite Paris-Sud 11, UMR8609, F-91405 ORSAY-Campus (France); Stuchbery, A. E. [Department of Nuclear Physics, Australian National University, Canberra (Australia); Jungclaus, A.; Modamio, V.; Walker, J. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain); Balabanski, D. L. [INRNE-BAS, Sofia (Bulgaria); Blazhev, A. [IKP, Cologne (Germany); Clement, E.; Grevy, S.; Stodel, C.; Thomas, J. C. [GANIL, Caen (France); Danchev, M. [University of Sofia (Bulgaria); Daugas, J. M. [CEA, DAM, DIF, 91297 Arpajon cedex (France); Hass, M.; Kumar, V. [The Weizmann Institute, Rehovot (Israel); Leske, J.; Pietralla, N. [TU Darmstadt, Darmstadt (Germany)

2009-08-26T23:59:59.000Z

333

Design features of high-intensity medium-energy superconducting heavy-ion Linac.  

DOE Green Energy (OSTI)

The proposed Rare Isotope Accelerator (RIA) requires the construction of a cw 1.4 GV superconducting (SC) linac that is capable of producing 400 kW beams of all ions from protons at 900 MeV to uranium at 400 MeV/u. The design of such a linac was outlined at the previous Linac conference. This linac will accelerate multiple-charge-states (multi-q) of the heaviest ion beams, for which the beam current is limited by ion-source performance. The linac consists of two different types of accelerating and focusing lattice: for uranium below {approx}85 MeV/u the focusing is provided by SC solenoids installed in cryostats with the SC resonators while in the high-beta section the focusing elements are located outside of the cryostats. A detailed design has been developed for the focusing-accelerating lattice of the linac. Beam dynamics studies have been performed with the goal of optimization of the linac structure in order to reduce a possible effective emittance growth of the multi-q uranium beam. A wide tuning range of the accelerating and focusing fields is required for acceleration of the variety of ions with different charge-to-mass ratios to the highest possible energy in single charge state mode. The focusing must be retuned for different ion masses to avoid resonance coupling between the transverse and longitudinal motions. Any visible impact of this coupling on the formation of beam halo must be avoided due to the high beam power.

Ostroumov, P. N.

2002-09-20T23:59:59.000Z

334

Heavy ion fusion half-year report, October 1, 1979-March 31, 1980  

Science Conference Proceedings (OSTI)

Major elements of the program in the first half of Fiscal Year 1980 included: (1) characterization of the 1 amp, 1 MV, 2 ..mu..s beam after acceleration through one pulsed drift tube; (2) observation of current and energy spikes at the onset of the beam pulse occasioned by the unusually long transit-time (approx. 1 ..mu..sec) of the mass 133 ions across the diode gap; (3) completion of the full system, comprising of source and three drift-tubes, in February 1980; (4) development of new beam diagnostic probes for high-intensity ion beams; and (5) a major re-direction of the design effort on the Induction Linac Test Bed to bring costs, based on R/D funds that include overhead, down from the 40 million system (described in LBL PUB-5031) to the canonical 25 million.

Not Available

1980-03-01T23:59:59.000Z

335

Formation of Dense Partonic Matter in High Energy Heavy-Ion Collisions: Highlights of RHIC Results  

E-Print Network (OSTI)

I review some important results from RHIC experiments. They were obtained in a unique environment for studying QCD bulk matter at temperatures and densities that surpass the limits where hadrons can exist as individual entities, raising the quark-gluon degrees of freedom to prominence. These findings support the major experimental observations from measuring the bulk properties of particle production, particle ratios and chemical freeze-out conditions, elliptic flow followed by hard probes measurements: di-jet fragment azimuthal correlations, high-pt hadron suppression, and heavy-flavors probes. I present the measurements as a function of collision centrality, energy, system size and for different particle species. These results reveal that a dense strongly interacting medium was created in central Au+Au collisions at 200 GeV: the RHIC discovery. Further, they suggest that this medium is partonic. However, the discoveries so far observed at RHIC are far from being understood fully. Accordingly, the focus of the experiments has shifted from the discovery phase to the detailed exploration phase of the properties of this medium.

Rachid Nouicer

2009-01-07T23:59:59.000Z

336

Coupled modes in magnetized dense plasma with relativistic-degenerate electrons  

SciTech Connect

Low frequency electrostatic and electromagnetic waves are investigated in ultra-dense quantum magnetoplasma with relativistic-degenerate electron and non-degenerate ion fluids. The dispersion relation is derived for mobile as well as immobile ions by employing hydrodynamic equations for such plasma under the influence of electromagnetic forces and pressure gradient of relativistic-degenerate Fermi gas of electrons. The result shows the coexistence of shear Alfven and ion modes with relativistically modified dispersive properties. The relevance of results to the dense degenerate plasmas of astrophysical origin (for instance, white dwarf stars) is pointed out with brief discussion on ultra-relativistic and non-relativistic limits.

Khan, S. A. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan)

2012-01-15T23:59:59.000Z

337

ATM-Dependent Hyper-Radiosensitivity in Mammalian Cells Irradiated by Heavy Ions  

SciTech Connect

Purpose: Low-dose hyper-radiosensitivity (HRS) and the later appearing radioresistance (termed induced radioresistance [IRR]) was mainly studied in low linear energy transfer (LET) radiation with survival observation. The aim of this study was to find out whether equivalent hypersensitivity occurred in high LET radiation, and the roles of ataxia telangiectasia mutated (ATM) kinase. Methods and Materials: Survival and mutation were measured by clonogenic assay and HPRT mutation assay. ATM Ser1981 activation was detected by Western blotting and immunofluorescent staining. Pretreatment of specific ATM inhibitor (10 {mu}M KU55933) and activator (20 {mu}g/mL chloroquine) before carbon radiation were adopted to explore the involvement of ATM. The roles of ATM were also investigated in its G2/M checkpoint function with histone H3 phosphorylation analysis and flow cytometric assay, and DNA double strand break (DSB) repair function measured using {gamma}-H2AX foci assay. Results: HRS/IRR was observed with survival and mutation in normal human skin fibroblast cells by carbon ions, while impaired in cells with intrinsic ATM deficiency or normal cells modified with specific ATM activator or inhibitor before irradiation. The dose-response pattern of ATM kinase activation was concordant with the transition from HRS to IRR. The ATM-dependent 'early' G2 checkpoint arrest and DNA DSB repair efficiency could explain the difference between HRS and IRR. Conclusions: These data demonstrate that the HRS/IRR by carbon ion radiation is an ATM-dependent phenomenon in the cellular response to DNA damage.

Xue Lian [School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou (China); Yu Dong [Tumor Endocrinology Project, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan)], E-mail: ydong@ncc.go.jp; Furusawa, Yoshiya [Heavy-Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba-shi (Japan); Cao Jianping [School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou (China); Okayasu, Ryuichi [Heavy-Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba-shi (Japan); Fan Saijun [School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou (China)

2009-09-01T23:59:59.000Z

338

Time delays in heavy-ion-induced fission of medium-Z nuclei, measured by crystal blocking  

Science Conference Proceedings (OSTI)

Time delays in fission induced by bombardment of Mo with 170- and 180-MeV {sup 32}S, 225- and 240-MeV {sup 48}Ti, and 300-MeV {sup 58}Ni have been measured by observation of crystal blocking of fission fragments. In contrast to earlier measurements with a W target, the results are consistent with fission of a compound nucleus in competition with mainly neutron emission. Most of the fissions happen on a time scale much shorter than attoseconds but there is a significant component of fission with much longer lifetimes. The measurements are reproduced with a standard statistical model, including a Kramers correction to fission widths from the viscosity of hot nuclear matter. These new results support the interpretation of our earlier measurements with a W target, which indicate that there is a transition in heavy-ion-induced fission at large atomic number and mass, from multichance fission in the standard Bohr-Wheeler picture to fission without formation of a compound nucleus. The process is slowed down by nuclear viscosity, with measured delays of order attoseconds.

Andersen, J. U. [Aarhus University; Chevallier, J. [University of Aarhus, Denmark; Forster, J. S. [Universite de Montreal; Karamian, S. A. [FLNR-JINR, Russia; Vane, C Randy [ORNL; Beene, James R [ORNL; Gross, Carl J [ORNL; Krause, Herbert F [ORNL; Liang, J Felix [ORNL; Shapira, Dan [ORNL; Uguzzoni, A. [University of Bologna

2012-01-01T23:59:59.000Z

339

Mass-energy distribution of fragments within Langevin dynamics of fission induced by heavy ions  

SciTech Connect

A stochastic approach based on four-dimensional Langevin fission dynamics is applied to calculating mass-energy distributions of fragments originating from the fission of excited compound nuclei. In the model under investigation, the coordinate K representing the projection of the total angular momentum onto the symmetry axis of the nucleus is taken into account in addition to three collective shape coordinates introduced on the basis of the {l_brace}c, h, {alpha}{r_brace} parametrization. The evolution of the orientation degree of freedom (K mode) is described by means of the Langevin equation in the overdamped regime. The tensor of friction is calculated under the assumption of the reducedmechanismof one-body dissipation in the wall-plus-window model. The calculations are performed for two values of the coefficient that takes into account the reduction of the contribution from the wall formula: k{sub s} 0.25 and k{sub s} = 1.0. Calculations with a modified wall-plus-window formula are also performed, and the quantity measuring the degree to which the single-particle motion of nucleons within the nuclear system being considered is chaotic is used for k{sub s} in this calculation. Fusion-fission reactions leading to the production of compound nuclei are considered for values of the parameter Z{sup 2}/A in the range between 21 and 44. So wide a range is chosen in order to perform a comparative analysis not only for heavy but also for light compound nuclei in the vicinity of the Businaro-Gallone point. For all of the reactions considered in the present study, the calculations performed within four-dimensional Langevin dynamics faithfully reproduce mass-energy and mass distributions obtained experimentally. The inclusion of the K mode in the Langevin equation leads to an increase in the variances of mass and energy distributions in relation to what one obtains from three-dimensional Langevin calculations. The results of the calculations where one associates k{sub s} with the measure of chaoticity in the single-particle motion of nucleons within the nuclear system under study are in good agreement for variances of mass distributions. The results of calculations for the correlations between the prescission neutron multiplicity and the fission-fragment mass, Left-Pointing-Angle-Bracket n{sub pre}(M) Right-Pointing-Angle-Bracket , and between, this multiplicity and the kinetic energy of fission fragments, Left-Pointing-Angle-Bracket n{sub pre}(E{sub k}) Right-Pointing-Angle-Bracket , are also presented.

Anischenko, Yu. A., E-mail: yuri.anischenko@gmail.com; Adeev, G. D. [Omsk State University (Russian Federation)

2012-08-15T23:59:59.000Z

340

Nuclear interactions in high energy heavy ions and applications in astrophysics. Technical progress report, 1 April 1992--31 March 1993  

SciTech Connect

The overall objective is to study the mechanisms and the energy dependence of heavy ion fragmentation by studying the reactions of heavy ion projectiles (e.g. {sup 4}He, {sup 16}O, {sup 20}Ne, {sup 28}Si, {sup 56}Fe) in a variety of targets (H, He, C, Si, Cu, Pb) and at a number of beam energies exceeding 0.1 GeV/nucleon. The results have application to questions in high-energy nuclear astrophysics. Most of the discussion is on low-energy {sup 16}O,{sup 28}Si data analysis. The description includes analysis procedures and techniques, detector calibrations, data selections and normalizations. Cross section results for the analysis are also presented. 83 figs., 6 tabs., 73 refs.

Wefel, J.P.; Guzik, T.G.

1993-01-11T23:59:59.000Z

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341

Nuclear interactions in high energy heavy ions and applications in astrophysics. [Dept. of Physics and Astronomy, Louisiana State Univ. , Baton Rouge  

SciTech Connect

The overall objective is to study the mechanisms and the energy dependence of heavy ion fragmentation by studying the reactions of heavy ion projectiles (e.g. [sup 4]He, [sup 16]O, [sup 20]Ne, [sup 28]Si, [sup 56]Fe) in a variety of targets (H, He, C, Si, Cu, Pb) and at a number of beam energies exceeding 0.1 GeV/nucleon. The results have application to questions in high-energy nuclear astrophysics. Most of the discussion is on low-energy [sup 16]O,[sup 28]Si data analysis. The description includes analysis procedures and techniques, detector calibrations, data selections and normalizations. Cross section results for the analysis are also presented. 83 figs., 6 tabs., 73 refs.

Wefel, J.P.; Guzik, T.G.

1993-01-11T23:59:59.000Z

342

Relativistic electron beam generator  

DOE Patents (OSTI)

A relativistic electron beam generator for laser media excitation is described. The device employs a diode type relativistic electron beam source having a cathode shape which provides a rectangular output beam with uniform current density.

Mooney, L.J.; Hyatt, H.M.

1975-11-11T23:59:59.000Z

343

Compositional analysis and depth profiling of thin film CrO{sub 2} by heavy ion ERDA and standard RBS: a comparison  

Science Conference Proceedings (OSTI)

Chromium dioxide (CrO{sub 2}) thin film has generated considerable interest in applied research due to the wide variety of its technological applications. It has been extensively investigated in recent years, attracting the attention of researchers working on spintronic heterostructures and in the magnetic recording industry. However, its synthesis is usually a difficult task due to its metastable nature and various synthesis techniques are being investigated. In this work a polycrystalline thin film of CrO{sub 2} was prepared by electron beam vaporization of Cr{sub 2}O{sub 3} onto a Si substrate. The polycrystalline structure was confirmed through XRD analysis. The stoichiometry and elemental depth distribution of the deposited film were measured by ion beam nuclear analytical techniques heavy ion elastic recoil detection analysis (ERDA) and Rutherford backscattering spectrometry (RBS), which both have relative advantage over non-nuclear spectrometries in that they can readily provide quantitative information about the concentration and distribution of different atomic species in a layer. Moreover, the analysis carried out highlights the importance of complementary usage of the two techniques to obtain a more complete description of elemental content and depth distribution in thin films. - Graphical abstract: Heavy ion elastic recoil detection analysis (ERDA) and Rutherford backscattering spectrometry (RBS) both have relative advantage over non-nuclear spectrometries in that they can readily provide quantitative information about the concentration and distribution of different atomic species in a layer. Highlights: Black-Right-Pointing-Pointer Thin films of CrO{sub 2} have been grown by e-beam evaporation of Cr{sub 2}O{sub 3} target in vacuum. Black-Right-Pointing-Pointer The composition was determined by heavy ion-ERDA and RBS. Black-Right-Pointing-Pointer HI-ERDA and RBS provided information on the light and heavy elements, respectively.

Khamlich, S., E-mail: skhamlich@gmail.com [Nano-Sciences Laboratories, Materials Research Department, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Department of Chemistry, Tshwane University of Technology, Private Bag X 680, Pretoria, 0001 (South Africa); The African Laser Centre, CSIR campus, P.O. Box 395, Pretoria (South Africa); Msimanga, M., E-mail: mandla@tlabs.ac.za [Nano-Sciences Laboratories, Materials Research Department, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); iThemba LABS Gauteng, Private Bag 11, WITS 2050, Johannesburg (South Africa); Pineda-Vargas, C.A. [Nano-Sciences Laboratories, Materials Research Department, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, C.P.U.T., P.O. Box 1906, Bellville 7535 (South Africa); Nuru, Z.Y. [Nano-Sciences Laboratories, Materials Research Department, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); McCrindle, R. [Department of Chemistry, Tshwane University of Technology, Private Bag X 680, Pretoria, 0001 (South Africa); Maaza, M. [Nano-Sciences Laboratories, Materials Research Department, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Department of Chemistry, Tshwane University of Technology, Private Bag X 680, Pretoria, 0001 (South Africa); The African Laser Centre, CSIR campus, P.O. Box 395, Pretoria (South Africa)

2012-08-15T23:59:59.000Z

344

A spectroscopic ellispometric study of the tunability of the optical constants and thickness of GeO{sub x} films with swift heavy ions  

Science Conference Proceedings (OSTI)

Sub-stoichiometric GeO{sub x} films were fabricated by electron-beam evaporation method. The films were irradiated with 100 MeV Ag{sup 7+} ions at fluences between 1 x 10{sup 12} and 1 x 10{sup 14} ions-cm{sup -2}. Spectroscopic ellipsometric measurements were performed in air at room temperature. The values of the layer thickness and refractive index were extracted from ellipsometry using a multilayer analysis and the Tauc Lorentz model. The refractive index (at 633 nm) of the as-deposited GeO{sub x} film was estimated to be 1.860 and decreased to 1.823 for films irradiated at an ion fluence of 1 x 10{sup 14} ions-cm{sup -2}. The thickness of the films also decreased after irradiation and is due to a sputtering induced by the ion beam. The change in the refractive index with ion fluence is attributed to a stoichiometric change and structural transformation represented by GeO{sub x}{yields} Ge + GeO{sub y} (y > x) occurring due to a thermal spike induced by ion irradiation. Swift heavy ions thus provide a scope for modulating the refractive index of GeO{sub x} films. The thickness and stoichiometric changes are supported by Rutherford backscattering measurements.

Vijayarangamuthu, K.; Singh, Chaman; Rath, Shyama [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Kabiraj, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

2011-09-15T23:59:59.000Z

345

CHEMICAL PROCESSING OF PURE AMMONIA AND AMMONIA-WATER ICES INDUCED BY HEAVY IONS  

SciTech Connect

Cosmic rays are possibly the main agents to prevent the freeze-out of molecules onto grain surfaces in cold dense clouds. Ammonia (NH{sub 3}) is one of the most abundant molecules present in dust ice mantles, with a concentration of up to 15% relative to water (H{sub 2}O). FTIR spectroscopy is used to monitor pure NH{sub 3} and NH{sub 3}-H{sub 2}O ice samples as they are irradiated with Ni and Zn ion beams (500-600 MeV) at GANIL/France. New species, such as hydrazine (N{sub 2}H{sub 4}), diazene (N{sub 2}H{sub 2} isomers), molecular hydrogen (H{sub 2}), and nitrogen (N{sub 2}) were identified after irradiation of pure NH{sub 3} ices. Nitrous oxide (N{sub 2}O), nitrogen oxide (NO), nitrogen dioxide (NO{sub 2}), and hydroxylamine (NH{sub 2}OH) are some of the products of the NH{sub 3}-H{sub 2}O ice radiolysis. The spectral band at 6.85 {mu}m was observed after irradiation of both types of ice. Besides the likely contribution of ammonium (NH{sub 4}{sup +}) and amino (NH{sub 2}) radicals, data suggest a small contribution of NH{sub 2}OH to this band profile after high fluences of irradiation of NH{sub 3}-H{sub 2}O ices. The spectral shift of the NH{sub 3} ''umbrella'' mode (9.3 {mu}m) band is parameterized as a function of NH{sub 3}/H{sub 2}O ratio in amorphous ices. Ammonia and water destruction cross-sections are obtained, as well as the rate of NH{sub 3}-H{sub 2}O (1:10) ice compaction, measured by the OH dangling bond destruction cross-section. Ammonia destruction is enhanced in the presence of H{sub 2}O in the ice and a power law relationship between stopping power and NH{sub 3} destruction cross-section is verified. Such results may provide relevant information for the evolution of molecular species in dense molecular clouds.

Bordalo, V.; Da Silveira, E. F. [Departamento de Fisica/Laboratorio do Acelerador Van de Graaff, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de S. Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil); Lv, X. Y.; Domaracka, A.; Rothard, H.; Boduch, P. [Centre de Recherche sur les Ions, les Materiaux et la Photonique (CEA/CNRS/ENSICAEN/Universite de Caen-Basse Normandie), CIMAP-CIRIL-GANIL, Boulevard Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Seperuelo Duarte, E., E-mail: vbordalo@fis.puc-rio.br [Grupo de Fisica e Astronomia, Instituto Federal do Rio de Janeiro, Rua Lucio Tavares 1045, 26530-060 Nilopolis, RJ (Brazil)

2013-09-10T23:59:59.000Z

346

Magnetic-sublevel population and alignment for the excitation of H- and He-like uranium in relativistic collisions  

Science Conference Proceedings (OSTI)

We have measured the alignment of the L-shell magnetic substates following the K-shell excitation of hydrogen- and helium-like uranium in relativistic collisions with a low-Z gaseous target. Within this experiment, the population distribution for the L-shell magnetic sublevels has been obtained via an angular differential study of the decay photons associated with the subsequent deexcitation process. The results show a very distinctive behavior for the H- and He-like heavy systems. In particular, for K{yields}L excitation of He-like uranium, a considerable alignment of the L-shell levels was observed. A comparison of our experimental findings with recent rigorous relativistic predictions provides a good qualitative and a reasonable quantitative agreement, emphasizing the importance of the magnetic-interaction and many-body effects in the strong-field domain of high-Z ions.

Gumberidze, A. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); FIAS Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main (Germany); Fritzsche, S. [FIAS Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 (Finland); Hagmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Institut fuer Kernphysik, University of Frankfurt, D-60486 Frankfurt (Germany); Kozhuharov, C.; Steck, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Ma, X. [Institute of Modern Physics, 730000 Lanzhou (China); Surzhykov, A. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet, Heidelberg (Germany); Warczak, A. [Institute of Physics, Jagiellonian University, Krakow (Poland); Stoehlker, Th. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet, Heidelberg (Germany); Helmholtz-Institut Jena, D-07743 Jena (Germany)

2011-10-15T23:59:59.000Z

347

Experimental Cross Sections for Reactions of Heavy Ions and 208Pb, 209Bi, 238U, and 248Cm Targets  

Science Conference Proceedings (OSTI)

The study of the reactions between heavy ions and {sup 208}Pb, {sup 209}Bi, {sup 238}U, and {sup 248} Cm targets was performed to look at the differences between the cross sections of hot and cold fusion reactions. Experimental cross sections were compared with predictions from statistical computer codes to evaluate the effectiveness of the computer code in predicting production cross sections. Hot fusion reactions were studied with the MG system, catcher foil techniques and the Berkeley Gas-filled Separator (BGS). 3n- and 4n-exit channel production cross sections were obtained for the {sup 238}U({sup 18}O,xn){sup 256-x}Fm, {sup 238}U({sup 22}Ne,xn){sup 260-x}No, and {sup 248}Cm({sup 15}N,xn){sup 263-x}Lr reactions and are similar to previous experimental results. The experimental cross sections were accurately modeled by the predictions of the HIVAP code using the Reisdorf and Schaedel parameters and are consistent with the existing systematics of 4n exit channel reaction products. Cold fusion reactions were examined using the BGS. The {sup 208}Pb({sup 48}Ca,xn){sup 256-x}No, {sup 208}Pb({sup 50}Ti,xn){sup 258-x}Rf, {sup 208}Pb({sup 51}V,xn){sup 259-x}Db, {sup 209}Bi({sup 50}Ti,xn){sup 259-x}Db, and {sup 209}Bi({sup 51}V,xn){sup 260-x}Sg reactions were studied. The experimental production cross sections are in agreement with the results observed in previous experiments. It was necessary to slightly alter the Reisdorf and Schaedel parameters for use in the HIVAP code in order to more accurately model the experimental data. The cold fusion experimental results are in agreement with current 1n- and 2n-exit channel systematics.

Patin, Joshua B.

2002-05-24T23:59:59.000Z

348

Studies of complex fragment emission in heavy ion reactions. Progress report, January 1, 1990--August 5, 1992  

Science Conference Proceedings (OSTI)

Our work involves the study of intermediate energy heavy-ion nuclear reactions. This work has two foci. On the one hand, we desire to learn about the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities. This purpose runs abreast of the second, which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because our experimental laboratory for studying nuclear matter properties is a dynamic one. We are forced to ask how nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. It may be that irrefutable information about nuclear matter will not be extracted from the reaction work. Nevertheless, we are compelled to undertake this effort not only because it is the only game in town and as yet we do not know that information cannot be extracted, but also because of our second objective. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. Our program has been: To study energy, mass, and angular momentum deposition by studying incomplete fusion reactions. To gain confidence that we understand how highly excited systems decompose by studying all emissions from the highly excited systems. To push these kinds of studies into the intermediate energy domain, with excitation function studies. And attempt to learn about the dynamics of the decays using particle-particle correlations. In the last effort, we have decided to focus on simple systems, where we believe, definitive statements are possible. These avenues of research share a common theme, large complex fragment production.

Charity, R.J.; Sobotka, L.G.

1992-09-01T23:59:59.000Z

349

High intensity production of high and medium charge state uranium and other heavy ion beams with VENUS  

E-Print Network (OSTI)

is the first third generation source routinely operated atIntroduction Third generation ECR ion sources are designedfor 4 th generation ECR ion sources [9] . The VENUS

Leitner, Daniela; Galloway, Michelle L.; Loew, Timothy J.; Lyneis, Claude M.; Rodriguez, Ingrid Castro; Todd, Damon S.

2008-01-01T23:59:59.000Z

350

Nuclear modification factor of nonphotonic electrons in heavy-ion collisions, and the heavy-flavor baryon-to-meson ratio  

E-Print Network (OSTI)

The nuclear modification factor R(AA) of nonphotonic electrons in Au + Au collisions at root(S)NN = 200 GeV is studied by considering the decays of heavy-flavor hadrons produced in a quark coalescence model. Although an enhanced Lambda(c)/D(0) ratio is predicted by the coalescence model, it is peaked at small transverse momenta (similar to 2 GeV) due to the large difference between heavy and light quark masses. As a result, the enhanced Lambda(c)/D(0) ratio, which is expected to suppress the electron R(AA) as the branching ratio of Lambda(c) decay into electrons is smaller than that of D(0), does not lead to additional suppression of the electron R(AA) at large transverse momenta (>= 5 GeV), where the suppression is mainly due to heavy quark energy loss in produced quark-gluon plasma. Also, the enhanced Lambda(b)/(B) over bar (0) ratio predicted by the coalescence model has even smaller effect on the nonphotonic electron R(AA) as bottom baryons and mesons have similar branching ratios for semileptonic decays into electrons.

Oh, Yongseok; Ko, Che Ming.

2009-01-01T23:59:59.000Z

351

Chemical freeze-out in ultra-relativistic heavy ion collisions at sqrt(s)_NN = 130 and 200 GeV  

E-Print Network (OSTI)

A comprehensive and detailed analysis of hadronic abundances measured in Au-Au collisions at RHIC at sqrt(s)_NN = 130 and 200 GeV is presented. The rapidity densities measured in the central rapidity region have been fitted to the statistical hadronization model and the chemical freeze-out parameters determined as a function of centrality, using data from experiments BRAHMS, PHENIX and STAR. The chemical freeze-out temperature turns out to be independent of centrality to a few percent accuracy, whereas the strangeness under-saturation parameter gamma_S decreases from almost unity in central collisions to a significantly lower value in peripheral collisions. Our results are in essential agreement with previous analyses, with the exception that fit quality at sqrt(s)_NN = 200 GeV is not as good as previously found. From the comparison of the two different energies, we conclude that the difference in fit quality, as described by chi2 values, is owing to the improved resolution of measurements which has probably exceeded the intrinsic accuracy of the simplified theoretical formula used in the fits.

J. Manninen; F. Becattini

2008-06-25T23:59:59.000Z

352

PROCEEDINGS OF THE SECOND WORKSHOP ON EXPERIMENTS AND DETECTORS FOR A RELATIVISTIC HEAVY ION COLLIDER (RHIC), LAWRENCE BERKELEY LABORATORY, MAY 25-29, 1987  

E-Print Network (OSTI)

at RHIC. Designing the "event trigger" is important for thecollisions, the event trigger for "high multiplicity" or "can be used as an event trigger in their experiment. We have

Ritter, Hans Georg

2010-01-01T23:59:59.000Z

353

PROCEEDINGS OF THE SECOND WORKSHOP ON EXPERIMENTS AND DETECTORS FOR A RELATIVISTIC HEAVY ION COLLIDER (RHIC), LAWRENCE BERKELEY LABORATORY, MAY 25-29, 1987  

E-Print Network (OSTI)

BGO crystals or Pb-glass blocks could be used. to comparelayer calorimetry, BOO or v Pb-glass blocks for em showers

Ritter, Hans Georg

2010-01-01T23:59:59.000Z

354

HEAVY-ION DOSIMETRY  

E-Print Network (OSTI)

10. These consist of a brass plate with a precisely maclrnedridge f i l t e r , an additional 4-rnn brass p l a t e , ac e r t r a l brass cylinder, and a concentric brass r i n

Schimmerling, W.

2010-01-01T23:59:59.000Z

355

HEAVY ION INERTIAL FUSION  

E-Print Network (OSTI)

in the Tokamak Fusion Test Reactor which will be completedDrivers and Reactors for Inertial Confinement Fusion, K.A.

Keefe, D.

2008-01-01T23:59:59.000Z

356

Hanbury Brown-Ttiss Correlation Functions from Event Generators: A Reliable Approach to Determine the Size of the Emitting Source in Ultrarelativistic Heavy Ion Collisions?  

E-Print Network (OSTI)

Employing NEXUS, one of the most recent simulation programs for heavy ions collisions, we investigate in detail the Hanbury-Twiss correlation function for charged pions for reactions 158 GeV Pb+Pb. For this study we supplement the standard simulation program by electromagnetic interactions. We find that the string fragmentation introduces strong space-momentum correlations and the freeze out times of the correlated pairs have a wide distribution. Both has a strong influence on the apparent source radius determined from the measured correlation correlation function.An equally strong influence is observed for the final state electromagnetic interaction.

F. Gastineau; J. Aichelin

2000-07-20T23:59:59.000Z

357

Matching heavy-light currents with NRQCD and HISQ quarks  

E-Print Network (OSTI)

We calculate the one loop renormalisation parameters for the heavy-light axial-vector and vector currents using lattice perturbation theory. We use NonRelativistic QCD (NRQCD) heavy quarks and the Highly Improved Staggered Quark (HISQ) action for the light quarks. We present results for heavy-light currents with massless HISQ quarks and briefly discuss the extension to heavy-heavy currents with massive HISQ quarks.

Christopher Monahan; Christine Davies; Ron Horgan; G. Peter Lepage; Heechang Na; Junko Shigemitsu

2012-10-25T23:59:59.000Z

358

DEVELOPMENTS IN HEAVY QUARKONIUM SPECTROSCOPY  

E-Print Network (OSTI)

­ 1­ DEVELOPMENTS IN HEAVY QUARKONIUM SPECTROSCOPY Written May 2012 by S. Eidelman (Budker Inst. Navas (Univ. Granada), and C. Patrignani (Univ. Genova, INFN). A golden age for heavy quarkonium physics at HERA and the Tevatron matured; and heavy-ion collisions at RHIC opened a window on the deconfinement

359

Multiplicity and angular distribution of particles emitted in relativistic nuclear-nuclear interactions  

E-Print Network (OSTI)

We discuss the experimental results on the behavior of the average multiplicities and angular distributions of slow particles emitted in hadron-nuclear and nuclear-nuclear interactions at relativistic energies as a function of the centrality of collisions. It is observed that by increasing the mass of the projectiles the angular distributions of slow particles change and the structure which was demonstrated in the case of pi-mesons, protons and light nuclear projectiles, almost disappears. During the interaction of the heavier projectile with nuclear target, the number of secondary interactions as well as number of nucleon-nucleon elastic scattering and re-scattering events increases. We suggest to restore this information using the heavy ion generators taking into account the multiplicity distributions. Because our investigations show that the formation of the percolation cluster sufficiently influences the behaviour of the average multiplicity of the slow particles emitted in these interactions.

M. K. Suleymanov; E. U. Khan; A. Kravchakova; Mahnaz Q. Haseeb; S. M. Saleem; Y. H. Huseynaliyev; S. Vokal; A. S. Vodopianov; O. B. Abdinov

2007-12-01T23:59:59.000Z

360

Relativistic Nuclear Collisions  

E-Print Network (OSTI)

A comprehensive introduction is given to the field of relativistic nuclear collisions, and the phase diagram of strongly interacting matter. The content of this complex of reviews is shown.

Reinhard Stock

2009-07-29T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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361

RELATIVISTIC NUCLEAR COLLISIONS: THEORY  

E-Print Network (OSTI)

Effects in Relativistic Nuclear Collisions", Preprint LBL-Pion Interferometry of Nuclear Collisions. 18.1 M.Gyulassy,was supported by the Office of Nuclear Physics of the U.S.

Gyulassy, M.

2010-01-01T23:59:59.000Z

362

Relativistic effects on nonlinear lower hybrid oscillations in cold plasma  

Science Conference Proceedings (OSTI)

Nonlinear lower hybrid mode in a quasineutral magnetized plasma is analyzed in one space dimension using Lagrangian coordinates. In a cold fluid, we treat electron fluid relativistically, whereas ion fluid nonrelativistically. The homotopy perturbation method is employed to obtain the nonlinear solution which also finds the frequency-amplitude relationship for the lower hybrid mode. The solution indicates that the amplitude of oscillation increases due to the weak relativistic effects. The appearance of density spikes is not ruled out in a magnetized plasma.

Maity, Chandan; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Sengupta, Sudip [Institute of Plasma Research, Bhat, Gandhinagar 382 428 (India)

2011-04-15T23:59:59.000Z

363

Single phase formation of Co-implanted ZnO thin films by swift heavy ion irradiation: Optical studies  

SciTech Connect

Low temperature photoluminescence and optical absorption studies on 200 MeV Ag{sup +15} ion irradiated Co-implanted ZnO thin films were studied. The Co clusters present in as implanted samples were observed to be dissolved using 200 MeV Ag{sup +15} ion irradiation with a fluence of 1x10{sup 12} ions/cm{sup 2}. The photoluminescence spectrum of pure ZnO thin film was characterized by the I{sub 4} peak due to the neutral donor bound excitons and the broad green emission. The Co-doped ZnO films show three sharp levels and two shoulders corresponding to 3t{sub 2g} and 2e{sub g} levels of crystal field splitted Co d orbitals, respectively. The ultraviolet-visible absorption spectroscopy also shows the systematic variation of band gap after 200 MeV Ag{sup +15} ion irradiation.

Kumar, Ravi; Singh, Fouran; Angadi, Basavaraj; Choi, Ji-Won; Choi, Won-Kook; Jeong, Kwangho; Song, Jong-Han; Khan, M. Wasi; Srivastava, J. P.; Kumar, Ajay; Tandon, R. P. [Materials Science Division, Inter-University Accelerator Centre, P.O. Box 10502, Aruna Asaf Ali Marg, New Delhi 110067 (India); Thin Films Materials Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650 (Korea, Republic of); Institute of Physics and Applied Physics, Yonsei University, Shincheon-dong 134, Seoul 120-749 (Korea, Republic of); Advanced Analysis Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650 (Korea, Republic of); Department of Physics, Aligarh Muslim University, Aligarh 202002 (India); Department of Physics and Astrophysics, Delhi University, Delhi 110007 (India)

2006-12-01T23:59:59.000Z

364

ION ACCELERATORS AS DRIVERS FOR INERTIAL CONFINEMENT FUSION  

E-Print Network (OSTI)

and Controlled Nuclear Fusion Research, Brussels, Belgium,of the Heavy Ion Fusion Workshop held at Brookhaven NationalReport, Hearthfire Heavy Ion Fusion, October 1, 1979 - March

Faltens, A.

2010-01-01T23:59:59.000Z

365

Coherence effects in heavy ion-atom collisions. [Total cross sections, F waves, charge capture, ionization, interference, scattering amplitudes  

DOE Green Energy (OSTI)

A new approach to charge capture and ionization by highly stripped projectiles is described and shown to explain cross section systematics through the periodic table. Oscillations in cross section with respect to charge state observed around atomic number 70 are explained as an f-wave resonance in the target electron-projectile scattering. The ratio of H/sub 2/ to H cross sections for both light and heavy projectiles is shown to fit a two center coherent scattering model; independent scattering by the two centers is not a good assumption for velocities below 4 a.u. Similar coherence effects are predicted in stripping by molecular gases even in multi-electron processes where the independent atom model might be thought valid. Recent experiments on the forward peak of electrons ejected from the projectile show interesting structure which can be partly explained without invoking interference effects. 7 references.

Bottcher, C.

1978-01-01T23:59:59.000Z

366

Brouwer's problem on a heavy particle in a rotating vessel: wave propagation, ion traps, and rotor dynamics  

E-Print Network (OSTI)

In 1918 Brouwer considered stability of a heavy particle in a rotating vessel. This was the first demonstration of a rotating saddle trap which is a mechanical analogue for quadrupole particle traps of Penning and Paul. We revisit this pioneering work in order to uncover its intriguing connections with classical rotor dynamics and fluid dynamics, stability theory of Hamiltonian and non-conservative systems as well as with the modern works on crystal optics and atomic physics. In particular, we find that the boundary of the stability domain of the undamped Brouwer's problem possesses the Swallowtail singularity corresponding to the quadruple zero eigenvalue. In the presence of dissipative and non-conservative positional forces there is a couple of Whitney umbrellas on the boundary of the asymptotic stability domain. The handles of the umbrellas form a set where all eigenvalues of the system are pure imaginary despite the presence of dissipative and non-conservative positional forces.

Oleg N. Kirillov

2010-12-04T23:59:59.000Z

367

3D Relativistic SPH  

E-Print Network (OSTI)

In this paper we present the equations and some basic applications of relativistic SPH. The equations are generated under the assumption that there are no interaction terms between the fluid modelled and the background space-time, i.e. we are neglecting the perturbations to the metric produced by the modelled fluid. This corresponds to a stationary metric, which for this work, we further limit to be static as well. The equations use a new signal velocity term and artificial viscosity to smear out the effects of strong shocks and are tested here against Newtonian and relativistic shocks.

Stuart Muir; Joe Monaghan

2003-12-11T23:59:59.000Z

368

Crystallization and collapse in relativistically degenerate matter  

SciTech Connect

In this paper, it is shown that a mass density limit exists beyond which the relativistically degenerate matter would crystallize. The mass density limit, found here, is quite analogous to the mass limit predicted by Chandrasekhar for a type of compact stars called white dwarfs (M{sub Ch} Asymptotically-Equal-To 1.43 Solar Mass). In this study, the old problem of white dwarf core collapse, which has been previously investigated by Chandrasekhar using hydrostatic stability criteria, is revisited in the framework of the quantum hydrodynamics model by inspection of the charge screening at atomic scales in the relativistic degeneracy plasma regime taking into account the relativistic Fermi-Dirac statistics and electron interaction features such as the quantum statistical pressure, Coulomb attraction, electron exchange-correlation, and quantum recoil effects. It is revealed that the existence of ion correlation and crystallization of matter in the relativistically degenerate plasma puts a critical mass density limit on white dwarf core region. It is shown that a white dwarf star with a core mass density beyond this critical limit can undergo the spontaneous core collapse (SCC). The SCC phenomenon, which is dominantly caused by the electron quantum recoil effect (interference and localization of the electron wave function), leads to a new exotic state of matter. In such exotic state, the relativistic electron degeneracy can lead the white dwarf crystallized core to undergo the nuclear fusion and an ultimate supernova by means of the volume reduction (due to the enhanced compressibility) and huge energy release (due to the increase in cohesive energy), under the stars huge inward gravitational pressure. Moreover, it is found that the SCC phenomenon is significantly affected by the core composition (it is more probable for heavier plasmas). The critical mass density found here is consistent with the values calculated for core density of typical white dwarf stars.

Akbari-Moghanjoughi, M. [International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum, Germany and Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz (Iran, Islamic Republic of)

2013-04-15T23:59:59.000Z

369

Fusion-fission and quasifission in the reactions with heavy ions leading to the formation of Hs  

Science Conference Proceedings (OSTI)

Mass and energy distributions of binary reaction products obtained in the reactions {sup 22}Ne+{sup 249}Cf,{sup 26}Mg+{sup 248}Cm,{sup 36}S+{sup 238}U and {sup 58}Fe+{sup 208}Pb leading to Hs isotopes have been measured. At energies below the Coulomb barrier the bimodal fission of Hs*, formed in the reaction {sup 26}Mg+{sup 248}Cm, is observed. In the reaction {sup 36}S+{sup 238}U the considerable part of the symmetric fragments arises from the quasifission process. At energies above the Coulomb barrier the symmetric fragments originate mainly from fusion-fission process for both reactions with Mg and S ions. In the case of the {sup 58}Fe+{sup 208}Pb reaction the quasifission process dominates at all measured energies. The pre- and post-scission neutron multiplicities as a function of the fragment mass have been obtained for the reactions studied.

Itkis, I. M.; Itkis, M. G.; Knyazheva, G. N.; Kozulin, E. M. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

2012-10-20T23:59:59.000Z

370

Fission and quasifission modes in heavy-ion-induced reactions leading to the formation of Hs{sup *}  

SciTech Connect

Mass and energy distributions of binary reaction products obtained in the reactions {sup 22}Ne+{sup 249}Cf,{sup 26}Mg+{sup 248}Cm, {sup 36}S+{sup 238}U, and {sup 58}Fe+{sup 208}Pb have been measured. All reactions lead to Hs isotopes. At energies below the Coulomb barrier the bimodal fission of Hs{sup *}, formed in the reaction {sup 26}Mg+{sup 248}Cm, is observed. In the reaction {sup 36}S+{sup 238}U, leading to the formation of a similar compound nucleus, the main part of the symmetric fragments arises from the quasifission process. At energies above the Coulomb barrier fusion-fission is the main process leading to the formation of symmetric fragments for both reactions with Mg and S ions. In the case of the {sup 58}Fe+{sup 208}Pb reaction the quasifission process dominates at all measured energies.

Itkis, I. M.; Kozulin, E. M.; Itkis, M. G.; Knyazheva, G. N.; Bogachev, A. A.; Chernysheva, E. V.; Krupa, L.; Oganessian, Yu. Ts.; Zagrebaev, V. I.; Rusanov, A. Ya.; Goennenwein, F.; Dorvaux, O.; Stuttge, L.; Hanappe, F.; Vardaci, E.; Goes Brennand, E. de [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Institute of Nuclear Physics of the National Nuclear Center of Kazakhstan, 050032 Almaty (Kazakhstan); Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen (Germany); Institut Pluridisciplinaire Hubert Curien and Universite de Strasbourg, F-67037 Strasbourg (France); Universite Libre de Bruxelles, CP229, B-1050 Bruxelles, Belgique (Belgium); Istituto Nazionale di Fisica Nucleare and Dipartimento di Scienze Fisiche dell'Universita di Napoli, Napoli (Italy); Departamento de Fisica, Universidade Estadual da Paraiba, 58109-753 Campina Grande (Brazil)

2011-06-15T23:59:59.000Z

371

Nuclear symmetry potential in the relativistic impulse approximation RID A-2398-2009 RID C-6879-2009  

E-Print Network (OSTI)

Using the relativistic impulse approximation with the Love-Franey NN scattering amplitude developed by Murdock and Horowitz, we investigate the low-energy (100 nuclear symmetry potential in isospin asymmetric nuclear matter. We find that the nuclear symmetry potential at fixed baryon density decreases with increasing nucleon energy. In particular, the nuclear symmetry potential at saturation density changes from positive to negative values at nucleon kinetic energy of about 200 MeV. Furthermore, the obtained energy and density dependence of the nuclear symmetry potential is consistent with those of the isospin- and momentum-dependent MDI interaction with x=0, which has been found to describe reasonably well both the isospin diffusion data from heavy-ion collisions and the empirical neutron-skin thickness of (208)Pb.

Li, Zeng-Hua; Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An; Ma, Hong-Ru.

2006-01-01T23:59:59.000Z

372

Relativistic Brownian motion: From a microscopic binary collision model to the Langevin equation  

E-Print Network (OSTI)

The Langevin equation (LE) for the one-dimensional relativistic Brownian motion is derived from a microscopic collision model. The model assumes that a heavy point-like Brownian particle interacts with the lighter heat bath particles via elastic hard-core collisions. First, the commonly known, non-relativistic LE is deduced from this model, by taking into account the non-relativistic conservation laws for momentum and kinetic energy. Subsequently, this procedure is generalized to the relativistic case. There, it is found that the relativistic stochastic force is still $\\gd$-correlated (white noise) but does \\emph{no} longer correspond to a Gaussian white noise process. Explicit results for the friction and momentum-space diffusion coefficients are presented and discussed.

Jrn Dunkel; Peter Hnggi

2006-07-04T23:59:59.000Z

373

Relativistic Pseudospin Symmetry  

Science Conference Proceedings (OSTI)

We show that the pseudospin symmetry that Akito Arima discovered many years ago (with collaborators) is a symmetry of the the Dirac Hamiltonian for which the sum of the scalar and vector potentials are a constant. In this paper we discuss some of the implications of this relativistic symmetry and the experimental data that support these predictions. In his original paper Akito also discussed pseudo-U(3) symmetry. We show that pseudo-U(3) symmetry is a symmetry of the Dirac Hamiltonian for which the sum of harmonic oscillator vector and scalar potentials are equal to a constant, and we give the generators of pseudo-U(3) symmetry. Going beyond the mean field we summarize new results on non relativistic shell model Hamiltonians that have pseudospin symmetry and pseudo-orbital angular momentum symmetry as a dynamical symmetries.

Ginocchio, Joseph N. [MS 283, Los Alamos National Laboratory, Los Alamos, NM, 87545 (United States)

2011-05-06T23:59:59.000Z

374

Extensivity and Relativistic Thermodynamics  

E-Print Network (OSTI)

The mathematical properties associated with the widely accepted concept of the extensivity of many of the common thermodynamic variables are examined and some of their consequences considered. The possible conflict between some of these and currently accepted results of special relativistic thermodynamics is highlighted. Although several questions are raised, answers are not advanced as this seems an area demanding calm, widespread reflection which could conceivably lead to radical revision of part, or parts, of theoretical physics.

J. Dunning-Davies

2007-06-27T23:59:59.000Z

375

JOURNAL DE PHYSIQUE Colloque C5, supplment au n \\\\, Tome 37., Novembre 1976., page C5-237 THE HEAVY ION FACILITY V I C K S I AT BERLIN  

E-Print Network (OSTI)

- und Strahlenphysik, H a h n - M e i t ~ r I n s t i t u t , Wissenschaftlicher Ergebnisbericht 1, 1974-237 THE HEAVY ION FACILITY V I C K S I AT BERLIN VICKSI-Group, presented t>y K. H. Lindenberger Bereich Kern' /3/ D. Hilscher e t a l . , IEEE Trans. Nucl. Sci. NS-22, No. 3, June 75, p. 1643 /4/ Bereich Kern

Paris-Sud XI, Université de

376

Relativistic mechanism of superconductivity  

E-Print Network (OSTI)

According to the theory of relativity, the relativistic Coulomb's force between an electron pair is composed of two parts, the main part is repulsive, while the rest part can be attractive in certain situations. Thus the relativistic attraction of an electron pair provides an insight into the mechanism of superconductivity. In superconductor, there are, probably at least, two kinds of collective motions which can eliminate the repulsion between two electrons and let the attraction being dominant, the first is the combination of lattice and electron gas, accounting for traditional superconductivity; the second is the electron gas themselves, accounting for high $T_c$ superconductivity. In usual materials, there is a good balance between the repulsion and attraction of an electron pair, the electrons are regarded as free electrons so that Fermi gas theory plays very well. But in some materials, when the repulsion dominates electron pairs, the electron gas will has a behavior opposite to superconductivity. In the present paper the superconducting states are discussed in terms of relativistic quantum theory in details, some significant results are obtained including quantized magnetic flux, London equation, Meissner effect and Josephson effect.

H. Y. Cui

2002-12-17T23:59:59.000Z

377

Precipitation of relativistic electrons of the Van Allen belts into the proton aurora  

Science Conference Proceedings (OSTI)

The Van Allen electron belts consist of two regions encircling the earth in which relativistic electrons are trapped in the earth's magnetic field. Populations of relativistic electrons in the Van Allen belts vary greatly with geomagnetic disturbance and they are a major source of damage to space vehicles. In order to know when and by how much these populations of relativistic electrons increase, it is important to elucidate not only the cause of acceleration of relativistic electrons but also the cause of their loss from the Van Allen belts. Here we show the first evidence that left-hand polarized electromagnetic ion cyclotron (EMIC) plasma waves can cause the loss of relativistic electrons into the atmosphere, on the basis of results of an excellent set of ground and satellite observations showing coincident precipitation of ions with energies of tens of keV and of relativistic electrons into an isolated proton aurora. The proton aurora was produced by precipitation of ions with energies of tens of keV due to EMIC waves near the plasma pause, which is a manifestation of wave-particle interactions. These observations clarify that ions with energies of tens of keV affect the evolution of relativistic electrons in the Van Allen belts via parasitic resonance with EMIC waves, an effect that was first theoretically predicted in the early 1970's.

Jordanova, Vania K [Los Alamos National Laboratory; Miyoshi, Y [NAGOYA UNIV; Sakaguchi, K [NAGOYA UNIV; Shiokawa, K [NAGOYA UNIV; Evans, D S [SEC/NOAA; Albert, Jay [AFRL; Connors, M [UNIV OF ATHABASCA

2008-01-01T23:59:59.000Z

378

What product might a renewal of Heavy IonFusion development offerthat competes with methane microbes and hydrogen HTGRs  

DOE Green Energy (OSTI)

In 1994 a Fusion Technology journal publication by Logan, Moir and Hoffman described how exploiting unusually-strong economy-of-scale for large (8 GWe-scale) multi-unit HIF plants sharing a driver and target factory among several low cost molten salt fusion chambers {at} < $40M per 2.4 GW fusion each (Fig. 1), could produce electricity below 3 cts/kWehr, even lower than similar multi-unit fission plants. The fusion electric plant could cost $12.5 B for 7.5 GWe and produce hydrogen fuel by electrolysis at prices competitive with gasoline-powered hybrids getting fuel from oil at $20$/bbl. At $60/bbl oil, the fusion plant can cost $35B and compete {at} 10% APR financing. Given massive and still-increasing world demand for transportation fuel even with oil climbing above $60/bbl, large HIF plants producing both low cost electricity and hydrogen could be more relevant to motivate new R&D funding for HIF development in the next few years. Three major challenges to get there: (1) NIF ignition in indirect drive geometry for liquid chambers, (2) a modular accelerator to enable a one-module IRE < $100 M, (3) compatible HIF target, driver and chamber allowing a small driver {at}< $500 M cost for a >100MWe net power DEMO. This scoping study, at a very preliminary conceptual level, attempts to identify how we might meet the last two great challenges taking advantage of several recent ideas and advances which motivate reconsideration of modular HIF drivers: >60X longitudinal compression of neutralized ion beams using a variable waveform induction module in NDCX down to 2 nanosecond bunches, the proof-of-principle demonstration of fast optical-gated solid state SiC switches by George Caporaso's group at LLNL (see George's RPIA06 paper), and recent work by Ed Lee, John Barnard and Hong Qin on methods for time-dependent correction of chromatic focusing errors in neutralized beams with up to 10 % {Delta}v/v velocity tilt, allowing 5 or more bunches, and shorter bunches, and possibly < 1 mm radius focal spot targets. We seek multi-pulsing with neutralized compression and focusing to enable higher peak power capability and the ability to create nearly arbitrary composite ''picket fence'' pulse shapes can be used to innovate HIF target designs for lower driver energy, and at the same time, reduce unit driver cost per joule for given driver energy, and reduce development time. For example, Debbie Callahan has explored close-coupled HIF targets with adequate gains > 40 that would need higher peak beam intensities in order to reduce total driver energy below 1 MJ. In principle, both PLIA and induction accelerators might benefit from multiple short bunches (see June 24, 2005 talk by Logan on multi-pulsing in PLIA accelerators for IFE), although the PLIA approach, because of fixed circuit wave velocities at any z, requires imaginative work-arounds to handle the different bunch velocities required. George's RPIA06 paper also describes a different type of radial line induction linac that might be considered, but its unclear how the required pulse-to-pulse variable waveforms can be obtained with such pulselines. This initial MathCad analysis explores multi-pulsing in modular solenoid induction linacs (concept shown in Figure 1) considering high-q ECR sources, basic induction acceleration limits assuming affordable agile waveforms, transverse and longitudinal bunch confinement constraints, models to optimize bunch lengths, solenoid fields, core radial builds and switching. Figure 2 below illustrates one linac module for a driver example (not yet optimized) consisting of 40 linacs (20 at each end). Necessarily, this first look invokes many new ideas, but could they potentially meet the above challenges?

Logan, Grant; Lee, Ed; Yu, Simon; Briggs, Dick; Barnard, John; Friedman, Alex; Qin, Hong; Waldron, Will; Leitner, Mattaheus; Kwan, Joe; Henestroza, Enrique; Caporaso, George; Meier, Wayne; Tabak, Max; Callahan, Debbie; Moir, Ralph; Peterson, Per

2006-04-19T23:59:59.000Z

379

Relativistic Quantum Communication  

E-Print Network (OSTI)

In this Ph.D. thesis, I investigate the communication abilities of non-inertial observers and the precision to which they can measure parametrized states. I introduce relativistic quantum field theory with field quantisation, and the definition and transformations of mode functions in Minkowski, Schwarzschild and Rindler spaces. I introduce information theory by discussing the nature of information, defining the entropic information measures, and highlighting the differences between classical and quantum information. I review the field of relativistic quantum information. We investigate the communication abilities of an inertial observer to a relativistic observer hovering above a Schwarzschild black hole, using the Rindler approximation. We compare both classical communication and quantum entanglement generation of the state merging protocol, for both the single and dual rail encodings. We find that while classical communication remains finite right up to the horizon, the quantum entanglement generation tends to zero. We investigate the observers' abilities to precisely measure the parameter of a state that is communicated between Alice and Rob. This parameter was encoded to either the amplitudes of a single excitation state or the phase of a NOON state. With NOON states the dual rail encoding provided greater precision, which is different to the results for the other situations. The precision was maximum for a particular number of excitations in the NOON state. We calculated the bipartite communication for Alice-Rob and Alice-AntiRob beyond the single mode approximation. Rob and AntiRob are causally disconnected counter-accelerating observers. We found that Alice must choose in advance with whom, Rob or AntiRob she wants to create entanglement using a particular setup. She could communicate classically to both.

Dominic Hosler

2013-06-20T23:59:59.000Z

380

129 Lecture Notes Relativistic Quantum Mechanics  

E-Print Network (OSTI)

129 Lecture Notes Relativistic Quantum Mechanics 1 Need for Relativistic Quantum Mechanics's equation of motion in mechanics. The initial condtions to solve the Newton's equation of motion

Murayama, Hitoshi

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Relativistic Photon Mediated Shocks  

E-Print Network (OSTI)

A system of equations governing the structure of a steady, relativistic radiation dominated shock is derived, starting from the general form of the transfer equation obeyed by the photon distribution function. Closure is obtained by truncating the system of moment equations at some order. The anisotropy of the photon distribution function inside the shock is shown to increase with increasing shock velocity, approaching nearly perfect beaming at upstream Lorentz factors $\\Gamma_{-}>>1$. Solutions of the shock equations are presented for some range of upstream conditions. These solutions are shown to converge as the truncation order is increased.

Amir Levinson; Omer Bromberg

2007-11-21T23:59:59.000Z

382

Heavy ion fusion--Using heavy ions to make electricity  

E-Print Network (OSTI)

as a source of commercial electrical power has been pursuedfusion to produce commercial electrical power has been anpower plant output would be high ? 2 GW); high electrical

Celata, C.M.

2004-01-01T23:59:59.000Z

383

ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.  

SciTech Connect

This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linac. The highly successful development of an EBIS at BNL now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based pre-injectors are presently used at most accelerator and collider facilities with the exception of RHIC, where the required gold beam intensities could only be met with a Tandem until the recent EBIS development. EBIS produces high charge state ions directly, eliminating the need for the two stripping foils presently used with the Tandem. Unstable stripping efficiencies of these foils are a significant source of luminosity degradation in RHIC. The high reliability and flexibility of the new Linac-based pre-injector will lead to increased integrated luminosity at RHIC and is an essential component for the long-term success of the RHIC facility. This new pre-injector, based on an EBIS, also has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium beams and, as part of a future upgrade, might also be used to produce polarized {sup 3}He beams. These capabilities will be critical to the future luminosity upgrades and electron-ion collisions in RHIC. The new RFQ and Linac that are used to accelerate beams from the EBIS to an energy sufficient for injection into the Booster are both very similar to existing devices already in operation at other facilities. Injection into the Booster will occur at the same location as the existing injection from the Tandem.

ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D.; ET AL.

2005-02-28T23:59:59.000Z

384

Ion Sources, Preinjectors and the Road to EBIS (459th Brookhaven Lecture)  

Science Conference Proceedings (OSTI)

To meet the requirements of the scientific programs of the Relativistic Heavy Ion Collider and the NASA Space Radiation Lab, BNL's Collider-Accelerator Department needs a variety of ion sources. Although these sources are a relatively small and inexpensive part of an accelerator, they can have a big impact on the machine's overall performance. For the 459th Brookhaven Lecture, James Alessi will describe C-AD's long history of developing state-of-the-art ion sources for its accelerators, and its current process for source and pre-injector development. He will follow up with a discussion of the features and development status of EBIS, which, as the newest source and preinjector, is in the final stages of commissioning at the end of a five-year construction project.

Alessi, James (BNL Collider-Accelerator Dept)

2010-07-21T23:59:59.000Z

385

Effects of momentum-dependent nuclear potential on two-nucleon correlation functions and light cluster production in intermediate energy heavy-ion collisions RID A-2398-2009  

E-Print Network (OSTI)

Using an isospin- and momentum-dependent transport model, we study the effects due to the momentum dependence of isoscalar nuclear potential as well as that of symmetry potential on two-nucleon correlation functions and light cluster production in intermediate energy heavy-ion collisions induced by neutron-rich nuclei. It is found that both observables are affected significantly by the momentum dependence of nuclear potential, leading to a reduction of their sensitivity to the stiffness of nuclear symmetry energy. However, the t/He-3 ratio remains a sensitive probe of the density dependence of nuclear symmetry energy.

Chen, LW; Ko, Che Ming; Li, Ba.

2004-01-01T23:59:59.000Z

386

ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.  

SciTech Connect

This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linear accelerator (Linac). The highly successful development of an EBIS at Brookhaven National Laboratory (BNL) now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based preinjectors are presently used at most accelerator and collider facilities with the exception of RHIC, where the required gold beam intensities could only be met with a Tandem until the recent EBIS development. EBIS produces high charge state ions directly, eliminating the need for the two stripping foils presently used with the Tandem. Unstable stripping efficiencies of these foils are a significant source of luminosity degradation in RHIC. The high reliability and flexibility of the new Linac-based pre-injector will lead to increased integrated luminosity at RHIC and is an essential component for the long-term success of the RHIC facility. This new pre-injector, based on an EBIS, also has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium beams and, as part of a future upgrade, might also be used to produce polarized {sup 3}He beams. These capabilities will be critical to the future luminosity upgrades and electron-ion collisions in RHIC. The proposed pre-injector system would also provide for a major enhancement in capability for the NASA Space Radiation Laboratory (NSRL), which utilizes heavy-ion beams from the RHIC complex. EBIS would allow for the acceleration of all important ion species for the NASA radiobiology program, such as, helium, argon, and neon which are unavailable with the present Tandem injector. In addition, the new system would allow for very rapid switching of ion species for NSRL experiments, reducing delays due to the interference with RHIC injection operations, and allowing enhanced mixed field radiation studies. The new RFQ and Linac that are used to accelerate beams from the EBIS to an energy sufficient for injection into the Booster are both very similar to existing devices already in operation at other facilities. Injection into the Booster will occur at the same location as the existing injection from the Tandem.

ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D.; GRANDINETTI, R.; HSEUH, H.; JAVIDFAR, A.; KPONOU, A.; LAMBIASE, R.; LESSARD, E.; LOCKEY, R.; LODESTRO, V.; MAPES, M.; MIRABELLA, D.; NEHRING, T.; OERTER, B.; PENDZICK, A.; PIKIN, A.; RAPARIA, D.; RITTER, J.; ROSER, T.; RUSSO, T.; SNYDSTRUP, L.; WILINSKI, M.; ZALTSMAN, A.; ZHANG, S.

2005-09-01T23:59:59.000Z

387

Parametic Study of the current limit within a single driver-scale transport beam line of an induction Linac for Heavy Ion Fusion  

E-Print Network (OSTI)

Physics of Magnetic Fusion Reactors, Rev. of Modern Physicsheavy ion beam driven fusion reactor study, Technical Reporta toroidally shaped fusion reactor (tokamak) such as shown

Prost, Lionel Robert

2007-01-01T23:59:59.000Z

388

RHIC | Electron-Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron-Ion Collider A breakthrough particle accelerator could collide electrons with heavy ions or protons at nearly the speed of light to create rapid-fire, high-resolution...

389

221B Lecture Notes Relativistic Quantum Mechanics  

E-Print Network (OSTI)

221B Lecture Notes Relativistic Quantum Mechanics 1 Need for Relativistic Quantum Mechanics We, similarly to the Newton's equation of motion in mechanics. The initial condtions to solve the Newton

Murayama, Hitoshi

390

221B Lecture Notes Relativistic Quantum Mechanics  

E-Print Network (OSTI)

221B Lecture Notes Relativistic Quantum Mechanics 1 Need for Relativistic Quantum Mechanics We's equation of motion in mechanics. The initial condtions to solve the Newton's equation of motion

Murayama, Hitoshi

391

Entropy Production in Simple Special Relativistic Fluids  

E-Print Network (OSTI)

It is well known that, in the absence of external forces, simple non-relativistic fluids involve entropy production only through heat conduction and shear viscosity. In this work, it is shown that a number density gradient contributes to the local entropy production of a simple relativistic fluid using special relativistic kinetic theory. Also, the presence of an external field may cause strictly relativistic contributions to the entropy production, a fact not widely recognized. The implications of these effects are thoroughly discussed.

D. Brun-Battistini; A. Sandoval-Villalbazo; A. L. Garcia-Perciante

2013-11-08T23:59:59.000Z

392

Relativistic Positioning Systems: current status  

E-Print Network (OSTI)

A {\\em relativistic positioning system} consists in a set of four clocks broadcasting their respective proper time by means of light signals. Among them, the more important ones are the {\\em auto-located positioning systems,} in which every clock broadcasts not only its proper time but also the proper times that it receives from the other three. At this level, no reference to any exterior system (the Earth surface, for example) and no synchronization are needed. The current status of the theory of relativistic positioning systems is sketched.

Bartolom Coll; Joan J. Ferrando; Juan A. Morales-Lladosa

2009-06-03T23:59:59.000Z

393

Final Scientific and Technical Report for Grant DE-FG02-99ER41099 Entitled Study the Collective Behavior of Quarks and Gluons in High Energy Nuclear Collisions  

SciTech Connect

This is the final technical/scientific report for a heavy ion research program on the PHOBOS experiment at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory.

Steven Manly

2008-09-08T23:59:59.000Z

394

Swift heavy ion irradiation-induced microstructure modification on two delta-phase oxides: Sc4Zr3O12 and Lu4Zr3O12  

Science Conference Proceedings (OSTI)

Swift gold ions (185 MeV) were used to systematically investigate the radiation damage response of delta phase compounds Sc{sub 4}Zr{sub 3}O{sub 12} and Lu{sub 4}Zr{sub 3}O{sub 12} in the electronic energy loss regime. Ion irradiation-induced microstructural modifications were examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD investigations indicate a phase transformation from ordered rhombohedral to disordered fluorite (O-D) in both compounds, with the Sc compound transforming at a higher ion fluence compared with the Lu compound. This result is consistent with our previous study on Sc{sub 4}Zr{sub 3}O{sub 12} and Lu{sub 4}Zr{sub 3}O{sub 12} under displacive radiation environment in which the nuclear energy loss is dominant. High resolution TEM revealed that individual ion tracks maintains crystalline structure where the core region experiences an O-D phase transformation. TEM observation also suggests that the O-D phase transformation occurs through the ion range after overlapping of ion tracks.

Tang, Ming [Los Alamos National Laboratory; Zhang, Jian [Los Alamos National Laboratory; Uberuaga, Blas P [Los Alamos National Laboratory; Sickafus, Kurt E [Los Alamos National Laboratory; Reichhardt, Cynthia J [Los Alamos National Laboratory; Kluth, Patrick [AUSTRALIA; Maulik, Patel [INDIA

2009-01-01T23:59:59.000Z

395

Kinetic equilibrium and relativistic thermodynamics  

E-Print Network (OSTI)

Relativistic thermodynamics is treated from the point of view of kinetic theory. It is shown that the generalized J\\"uttner distribution suggested in [1] is compatible with kinetic equilibrium. The requirement of compatibility of kinetic and thermodynamic equilibrium reveals several generalizations of the Gibbs relation where the velocity field is an independent thermodynamic variable.

Vn, P

2011-01-01T23:59:59.000Z

396

Kinetic equilibrium and relativistic thermodynamics  

E-Print Network (OSTI)

Relativistic thermodynamics is treated from the point of view of kinetic theory. It is shown that the generalized J\\"uttner distribution suggested in [1] is compatible with kinetic equilibrium. The requirement of compatibility of kinetic and thermodynamic equilibrium reveals several generalizations of the Gibbs relation where the velocity field is an independent thermodynamic variable.

P. Vn

2011-02-01T23:59:59.000Z

397

Heavy Oil Projects  

NLE Websites -- All DOE Office Websites (Extended Search)

Select Reports from Heavy Oil Projects Project Number Performer Title Heavy Oil Recovery US (NIPERBDM-0225) BDM-Oklahoma, Inc. Feasibility Study of Heavy Oil Recovery in the...

398

ECR (Electron Cyclotron Resonance) ion sources for cyclotrons  

SciTech Connect

In the last decade ECR (Electron Cyclotron Resonance) ion sources have evolved from a single large, power consuming, complex prototype into a variety of compact, simple, reliable, efficient, high performance sources of high charge state ions for accelerators and atomic physics. The coupling of ECR sources to cyclotrons has resulted in significant performance gains in energy, intensity, reliability, and variety of ion species. Seven ECR sources are in regular operation with cyclotrons and numerous other projects are under development or in the planning stag. At least four laboratories have ECR sources dedicated for atomic physics research and other atomic physics programs share ECR sources with cyclotrons. An ECR source is now installed on the injector for the CERN SPS synchrotron to accelerate O/sup 8 +/ to relativistic energies. A project is underway at Argonne to couple an ECR source to a superconducting heavy-ion linac. Although tremendous progress has been made, the field of ECR sources is still a relatively young technology and there is still the potential for further advances both in source development and understanding of the plasma physics. The development of ECR sources is reviewed. The important physics mechanisms which come into play in the operation of ECR Sources are discussed, along with various models for charge state distributions (CSD). The design and performance of several ECR sources are compared. The 88-Inch Cyclotron and the LBL ECR is used as an example of cyclotron+ECR operation. The future of ECR sources is considered.

Lyneis, C.M.

1986-10-01T23:59:59.000Z

399

ccsd00001714, Nonlinear dynamics of electromagnetic pulses in cold relativistic plasmas  

E-Print Network (OSTI)

ccsd­00001714, version 2 ­ 19 Oct 2004 Nonlinear dynamics of electromagnetic pulses in cold particle and photon accel- eration, nonlinear optics, laser fusion, and others [1{6]. Intense of coupled electromagnetic and electrostatic modes in cold relativistic electron-ion plas- mas to conclude

400

Relativistic study of the nuclear anapole moment effects in diatomic molecules  

E-Print Network (OSTI)

Nuclear-spin-dependent (NSD) parity violating effects are studied for a number of diatomic molecules using relativistic Hartree-Fock and density functional theory and accounting for core polarization effects. Heavy diatomic molecules are good candidates for the successful measurement of the nuclear anapole moment, which is the dominant NSD parity violation term in heavy elements. Improved results for the molecules studied in our previous publication [Borschevsky et al., Phys. Rev. A 85, 052509 (2012)] are presented along with the calculations for a number of new promising candidates for the nuclear anapole measurements.

Borschevsky, A; Dzuba, V A; Flambaum, V V; Schwerdtfeger, P

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

SciTech Connect: "smart grid"  

Office of Scientific and Technical Information (OSTI)

Project Theory of ultra-relativistic heavy-ion collisions'' Citation Details In-Document Search Title: Final Report for Project Theory of ultra-relativistic heavy-ion...

402

Rapid plasma heating by collective interactions, using strong turbulence and relativistic electron beams  

SciTech Connect

A multi-kilovolt, moderate density plasma was generated in a magnetic mirror confinement system by two methods: turbulent heating and relativistic electron beam. Extensive diagnostic development permitted the measurement of important plasma characteristics, leading to interesting and novel conclusions regarding heating and loss mechanisms. Electron and ion heating mechanisms were categorized, and parameter studies made to establish ranges of importance. Nonthermal ion and electron energy distributions were measured. Beam propagation and energy deposition studies yielded the spatial dependence of plasma heating.

Wharton, C.B.

1977-01-01T23:59:59.000Z

403

Simple Cosmological Model with Relativistic Gas  

E-Print Network (OSTI)

We construct simple and useful approximation for the relativistic gas of massive particles. The equation of state is given by an elementary function and admits analytic solution of the Friedmann equation, including more complex cases when the relativistic gas of massive particles is considered together with radiation or with dominating cosmological constant. The model of relativistic gas may be interesting for the description of primordial Universe, especially as a candidate for the role of a Dark Matter.

Guilherme de Berredo-Peixoto; Ilya L. Shapiro; Flavia Sobreira

2004-12-11T23:59:59.000Z

404

Mesoscopic Superposition States in Relativistic Landau Levels  

Science Conference Proceedings (OSTI)

We show that a linear superposition of mesoscopic states in relativistic Landau levels can be built when an external magnetic field couples to a relativistic spin 1/2 charged particle. Under suitable initial conditions, the associated Dirac equation produces unitarily superpositions of coherent states involving the particle orbital quanta in a well-defined mesoscopic regime. We demonstrate that these mesoscopic superpositions have a purely relativistic origin and disappear in the nonrelativistic limit.

Bermudez, A.; Martin-Delgado, M. A. [Departamento de Fisica Teorica I, Universidad Complutense, 28040 Madrid (Spain); Solano, E. [Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado Postal 1761, Lima (Peru)

2007-09-21T23:59:59.000Z

405

Relativistic Bernstein waves in a degenerate plasma  

SciTech Connect

Bernstein mode for a relativistic degenerate electron plasma is investigated. Using relativistic Vlasov-Maxwell equations, a general expression for the conductivity tensor is derived and then employing Fermi-Dirac distribution function a generalized dispersion relation for the Bernstein mode is obtained. Two limiting cases, i.e., non-relativistic and ultra-relativistic are discussed. The dispersion relations obtained are also graphically presented for some specific values of the parameters depicting how the propagation characteristics of Bernstein waves as well as the Upper Hybrid oscillations are modified with the increase in plasma number density.

Ali, Muddasir; Hussain, Azhar [Department of Physics, G.C. University, Lahore 54000 (Pakistan); Salam Chair in Physics, G.C. University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, G.C. University, Lahore 54000 (Pakistan)

2011-09-15T23:59:59.000Z

406

Dynamics of the ion-ion acoustic instability in the thermalization of ion beams  

SciTech Connect

Particle simulation using a nonlinear adiabatic electron response with two streaming ion species and nonlinear theory are used to study the collisionless thermalization of ion beams in a hot electron plasma. The slow beam or subsonic regime is investigated and the criterion for the transition from predominantly light ion to predominantly heavy ion heating is developed. Long-lived ion hole structures a-re observed in the final state.

Han, J.H.; Horton, W. (Texas Univ., Austin, TX (United States). Inst. for Fusion Studies); Leboeuf, J.N. (Oak Ridge National Lab., TN (United States))

1992-07-01T23:59:59.000Z

407

Jet quenching and heavy quarks  

E-Print Network (OSTI)

Jet quenching and more generally physics at high transverse momentum P_T scales is a cornerstone of the heavy-ion physics program at the LHC. In this work, the current understanding of jet quenching in terms of a QCD shower evolution being modified by the surrounding medium is reviewed along with the evidence for this picture from light parton high P_T observables. Conceptually, the same QCD shower description should also be relevant for heavy quarks, but with several important modifications introduced by the quark masses. Thus especially in the limit of small jet energy over quark mass E_jet/m_q, the relevant physics may be rather different from light quark jets, and several attempts to explain the observed phenomenology of heavy quarks at high P_T are discussed here.

Thorsten Renk

2013-09-12T23:59:59.000Z

408

Graphical aids for relativistic optics  

E-Print Network (OSTI)

The paper presents a relativistic space-time diagram, which displays in true values the space (Cartesian and polar) and the time coordinates of the same event detected from two inertial reference frames in relative motion related by the Lorentz-Einstein transformations, the aberration angles and the Doppler shifted periods and wavelengths. We use it in order to illustrate the reflection of light on moving mirrors (horizontal and vertical) and the way in which a single observer could measure the length of a moving rod. It displays in true values the space-time coordinates of the same event generated by a light signal.

Bernhard Rothenstein; Corina Nafornita

2005-03-01T23:59:59.000Z

409

Conservative, special-relativistic smoothed particle hydrodynamics  

Science Conference Proceedings (OSTI)

We present and test a new, special-relativistic formulation of smoothed particle hydrodynamics (SPH). Our approach benefits from several improvements with respect to earlier relativistic SPH formulations. It is self-consistently derived from the Lagrangian ... Keywords: Computational fluid dynamics, Shocks, Smoothed particle hydrodynamics, Special relativity

Stephan Rosswog

2010-11-01T23:59:59.000Z

410

Coherent Dissociation of Relativistic $^{12}$N Nuclei  

E-Print Network (OSTI)

The dissociation of relativistic $^{12}$N nuclei having a momentum of 2 GeV/c per nucleon and undergoing the most peripheral interactions in a track emulsion is studied. The picture of charged topology of product ensembles of relativistic fragments and special features of their angular distributions are presented.

R. R. Kattabekov; K. Z. Mamatkulov; S. S. Alikulov; D. A. Artemenkov; R. N. Bekmirzaev; V. Bradnova; P. I. Zarubin; I. G. Zarubina; N. V. Kondratieva; N. K. Kornegrutsa; D. O. Krivenkov; A. I. Malakhov; K. Olimov; N. G. Peresadko; N. G. Polukhina; P. A. Rukoyatkin; V. V. Rusakova; R. Stanoeva; S. P. Kharlamov

2013-10-08T23:59:59.000Z

411

Relativistic Multireference Many-body Perturbation Theory for Open-shell Ions with Multiple Valence Shell Electrons: the Transition Rates and Lifetimes of the Excited Levels in Chlorinelike Fe X  

SciTech Connect

A recently developed relatistic multireference many-body perturbation theory based on multireference configuration-interaction wavefunctions as zeroth order wavefunctions is outlined. The perturbation theory employs a general class of configuration-interaction wve functions as reference functions, and thus is applciable to multiple open valence shell systems with near degeneracy of a manifold of strongly interacting configurations. Multireference many-body perturbation calculations are reported for the ground and excited states of chlorine-like Fe X in which the near degeneracy of a manifold of strongly interacting configurations mandates a multireference treatment. Term energies of a total of 83 excited levels arising from the 3s{sup 2}3p{sup 5}, 3s3p{sup 6}, 3s{sup 2}3p{sup 4}3d, 3s3p{sup 5}3d, and 3s{sup 2}3p{sup 3}3d{sup 2} configurations of the ion are evaluated to high accuracy. Transition rates associated with E1/M1/E2/M2/E3 radiative decays and lifetimes of a number of excited levels are calculated and compared with laboratory measurements to critically evaluate recent experiments.

Ishikawa, Y; Santana, J A; Tr?bert, E

2009-09-30T23:59:59.000Z

412

Parallel, grid-adaptive approaches for relativistic hydro and magnetohydrodynamics  

Science Conference Proceedings (OSTI)

Relativistic hydro and magnetohydrodynamics provide continuum fluid descriptions for gas and plasma dynamics throughout the visible universe. We present an overview of state-of-the-art modeling in special relativistic regimes, targeting strong shock-dominated ... Keywords: AMR, Relativistic HD, Relativistic MHD, Shock-capturing schemes

R. Keppens; Z. Meliani; A. J. van Marle; P. Delmont; A. Vlasis; B. van der Holst

2012-02-01T23:59:59.000Z

413

Kadomtsev-Petviashvili solitons propagation in a plasma system with superthermal and weakly relativistic effects  

SciTech Connect

Two dimensional (2D) solitons are studied in a plasma system comprising of relativistically streaming ions, kappa distributed electrons, and positrons. Kadomtsev-Petviashvili (KP) equation is derived through the reductive perturbation technique. Analytical solution of the KP equation has been studied numerically and graphically. It is noticed that kappa parameters of electrons and positrons as well as the ions relativistic streaming factor have an emphatic influence on the structural as well as propagation characteristics of two dimensional solitons in the considered plasma system. Our results may be helpful in the understanding of soliton propagation in astrophysical and laboratory plasmas, specifically the interaction of pulsar relativistic wind with supernova ejecta and the transfer of energy to plasma by intense electric field of laser beams producing highly energetic superthermal and relativistic particles [L. Arons, Astrophys. Space Sci. Lib. 357, 373 (2009); P. Blasi and E. Amato, Astrophys. Space Sci. Proc. 2011, 623; and A. Shah and R. Saeed, Plasma Phys. Controlled Fusion 53, 095006 (2011)].

Hafeez-Ur-Rehman; Mahmood, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Department of Physics and Applied Mathematics, PIEAS, Nilore, 44000 Islamabad (Pakistan); Shah, Asif; Haque, Q. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

2011-12-15T23:59:59.000Z

414

Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies  

E-Print Network (OSTI)

We study a particular class of relativistic nuclear energy density functionals in which only nucleon degrees of freedom are explicitly used in the construction of effective interaction terms. Short-distance (high-momentum) correlations, as well as intermediate and long-range dynamics, are encoded in the medium (nucleon density) dependence of the strength functionals of an effective interaction Lagrangian. Guided by the density dependence of microscopic nucleon self-energies in nuclear matter, a phenomenological ansatz for the density-dependent coupling functionals is accurately determined in self-consistent mean-field calculations of binding energies of a large set of axially deformed nuclei. The relationship between the nuclear matter volume, surface and symmetry energies, and the corresponding predictions for nuclear masses is analyzed in detail. The resulting best-fit parametrization of the nuclear energy density functional is further tested in calculations of properties of spherical and deformed medium-heavy and heavy nuclei, including binding energies, charge radii, deformation parameters, neutron skin thickness, and excitation energies of giant multipole resonances.

T. Niksic; D. Vretenar; P. Ring

2008-09-08T23:59:59.000Z

415

LIPS-thermalization of a relativistic gas  

E-Print Network (OSTI)

It is argued that two-particle collisions of relativistic particles "at a distance", irrespective of their position in the configuration space, generate uniform distribution of particles in Lorentz invariant phase space.

Vladimr Balek

2011-01-31T23:59:59.000Z

416

Star Products for Relativistic Quantum Mechanics  

E-Print Network (OSTI)

The star product formalism has proved to be an alternative formulation for nonrelativistic quantum mechanics. We want introduce here a covariant star product in order to extend the star product formalism to relativistic quantum mechanics in the proper time formulation.

P. Henselder

2007-05-24T23:59:59.000Z

417

Ion Sources - Cyclotron  

NLE Websites -- All DOE Office Websites (Extended Search)

Sources Sources The 88-Inch Cyclotron is fed by three Electron Cyclotron Resonance (ECR) high-charge-state ion sources, the ECR, the AECR, and VENUS, currently the most powerful ECR ion source in the world. Built to answer the demand for intense heavy ion beams, these high performance ion sources enable the 88-Inch Cyclotron to accelerate beams of ions from hydrogen to uranium. The ECR ion sources allow the efficient use of rare isotopes of stable elements, either from natural or enriched sources. A variety of metallic ion beams are routinely produced in our low temperature oven (up to 600°C) and our high temperature oven (up to 2100°C). Furthermore, the ability to produce "cocktails" (mixtures of beams) for the Berkeley Accelerator Space Effects (BASE) Facility adds tremendously to the flexibility of the 88-Inch Cyclotron.

418

Microscopic Calculation of Fusion: Light to Heavy Systems  

E-Print Network (OSTI)

The density-constrained time-dependent Hartree-Fock (DC-TDHF) theory is a fully microscopic approach for calculating heavy-ion interaction potentials and fusion cross sections below and above the fusion barrier. We discuss recent applications of DC-TDHF method to fusion of light and heavy neutron-rich systems.

A. S. Umar; V. E. Oberacker; J. A. Maruhn; R. Keser

2013-10-02T23:59:59.000Z

419

Atomic Physics Aspects of a Relativistic Nuclear Collider  

DOE Green Energy (OSTI)

Atomic collision cross sections involving bare uranium nuclei are large at relativistic energies and will affect the design and operation of a relativistic nuclear collider (RNC). The most significant may be production of electron-positron pairs and muon pairs ({approx} 10{sup 8} per sec. and 2000 per sec. respectively for a 100 GeV/nucleon collider with a luminosity of 10{sup 27} cm{sup 2} s{sup -1}). Although the pair production is a direct measure of the luminosity it is also a large source of background and capture of an electron from the pair by one of the nuclei will result in the loss of the ion. Another important loss mechanism is Coulomb excitation of the giant nuclear dipole and giant nuclear quadrupole resonances. Storing and colliding bare and highly-stripped uranium opens up new possibilities for novel atomic physics experiments and an alternate approach for present experiments. As examples, the use of a collider for experiments to study spontaneous decay of the super-critical state (both positron production and x-ray production) of quasi-atoms of atomic number Z > 172, and a storage-ring measurement of the ground state hyperfine structure of hydrogen like thallium as a test of quantum electrodynamics (QED) are discussed.

Gould, R.

1984-11-01T23:59:59.000Z

420

Diffusive Shock Acceleration in Unmodified Relativistic, Oblique Shocks  

E-Print Network (OSTI)

We present results from a fully relativistic Monte Carlo simulation of diffusive shock acceleration (DSA) in unmodified shocks. The computer code uses a single algorithmic sequence to smoothly span the range from nonrelativistic speeds to fully relativistic shocks of arbitrary obliquity, providing a powerful consistency check. While known results are obtained for nonrelativistic and ultra-relativistic parallel shocks, new results are presented for the less explored trans- relativistic regime and for oblique, fully relativistic shocks. We find, for a wide trans-relativistic range extending to shock Lorentz factors >30, that the particle spectrum produced by DSA varies strongly from the canonical f(p) proportional to p^{-4.23} spectrum known to result in ultra-relativistic shocks. Trans- relativistic shocks may play an important role in gamma-ray bursts and other sources and most relativistic shocks will be highly oblique.

Donald C. Ellison; Glen P. Double

2004-08-27T23:59:59.000Z

Note: This page contains sample records for the topic "relativistic heavy ion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Observation of relativistic antihydrogen atoms  

DOE Green Energy (OSTI)

An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {bar H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +} e{sup -} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

Blanford, Glenn DelFosse

1998-01-01T23:59:59.000Z

422

AN INTENSE NON-RELATIVISTIC CESIUM ION BEAM  

E-Print Network (OSTI)

of the Diagnostic Tank Showing ESP Example Data Set of EBPElectron Beam Probe (ESP) was developed as an independentbetween measurements with the ESP and the small, movable

Lampel, M.C.

2010-01-01T23:59:59.000Z

423

Tetraquark bound states in the heavy-light heavy-light system  

Science Conference Proceedings (OSTI)

A calculation of the interaction potential of a heavy-light heavy-light (HLHL) system in lattice QCD is used to study the existence of tetraquark bound states. The interaction potential of the tetraquark system is calculated on the lattice with 2+1 flavours of dynamical fermions with lattice interpolating fields constructed using colorwave propagators. These propagators provide a new method for constructing all-to-all spatially smeared the interpolating fields, a technique which allows for a better overlap with the ground state wavefunction as well as reduced statistical noise. Lattice HLHL potentials are extracted for 24 distinct channels, and are fit with a phenomenological non-relativistic quark model potential, from which a determination of the existence of bound states is made via numerical solution of the two body radial Schroedinger equation.

Konstantinos Orginos, Zachary Brown

2012-12-01T23:59:59.000Z

424

Inductive and Electrostatic Acceleration in Relativistic Jet-Plasma Interactions  

Science Conference Proceedings (OSTI)

We report on the observation of rapid particle acceleration in numerical simulations of relativistic jet-plasma interactions and discuss the underlying mechanisms. The dynamics of a charge-neutral, narrow, electron-positron jet propagating through an unmagnetized electron-ion plasma was investigated using a three-dimensional, electromagnetic, particle-in-cell computer code. The interaction excited magnetic filamentation as well as electrostatic (longitudinal) plasma instabilities. In some cases, the longitudinal electric fields generated inductively and electrostatically reached the cold plasma wave-breaking limit, and the longitudinal momentum of about half the positrons increased by 50% with a maximum gain exceeding a factor of two. The results are relevant to understanding the micro-physics at the interface region of an astrophysical jet with the interstellar plasma, for example, the edge of a wide jet or the jet-termination point.

Ng, Johnny S.T.; Noble, Robert J.; /SLAC

2005-07-13T23:59:59.000Z

425

Hot-electron refluxing enhanced relativistic transparency of overdense plasmas  

E-Print Network (OSTI)

A new phenomenon of enhancing the relativistic transparency of overdense plasmas by the influence of hot-electron refluxing has been found via particle-in-cell simulations. When a p-polarized laser pulse, with intensity below the self-induced-transparency (SIT) threshold, obliquely irradiates a thin overdense plasma, the initially opaque plasma would become transparent after a time interval which linearly relies on the thickness of the plasma. This phenomenon can be interpreted by the influence of hot-electron refluxing. As the laser intensity is higher than the SIT threshold, the penetration velocity of the laser in the plasma is enhanced when the refluxing is presented. Simulation data with ion motion considered is also consistent with the assumption that hot-electron refluxing enhances transparency. These results have potential applications in laser shaping.

Yu, Yong; Chen, Zi-Yu; Wang, Jia-Xiang; Zhu, Wen-Jun

2013-01-01T23:59:59.000Z

426

Relativistic electromagnetic flat top solitons and their stability  

Science Conference Proceedings (OSTI)

The inclusion of ion response in the study of relativistically intense electromagnetic laser pulse propagation in plasma yields certain distinct varieties of single peak solitonic structures. A flat top slow moving structure (for which the various fields have a flat profile over a wide spatial range) is one such solution. A detailed characterization of these solutions along with the eigen spectrum of their formation in the parameter space has been presented. The evolution of this particular solution is studied in detail with the help of a coupled fluid Maxwell set of equations. The study shows that the flat top solution is unstable. The instability is characterized as the backward Brillouin instability for which the electron quiver velocity plays the role of the effective temperature.

Sundar, Sita; Das, Amita; Saxena, Vikrant; Kaw, Predhiman; Sen, Abhijit [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)

2011-11-15T23:59:59.000Z

427

Heavy-Ion Fusion Science (HIFS)  

NLE Websites -- All DOE Office Websites (Extended Search)

gain of energy. Instead of using enormous lasers (as in laser fusion) or magnets (as in ITER) to cause the fuel pellet to compress, the idea is to use a very high-current particle...

428

098- Swift Heavy Ion Irradiation of Gd  

Science Conference Proceedings (OSTI)

125- Influence of Gas Flow Rate Ratio on the Structural Properties of a-SiC:H Prepared by ... 145- The Synergy of XRD and XRF in a Shale and Slate Analysis.

429

HEAVY-ION RADIOBIOLOGY: CELLULAR STUDIES  

E-Print Network (OSTI)

S! , Ar 4 ll! 1d 10 em brass "Submarine Reprod. lntegl'ltymd Ill! , fir 4 em Pb and 10 em brass Chapman et al. , 1977,No Hallet a1. , 1977 10 em brass Raju and Phillips, 1977 C,

Blakely, Eleanor A.

2013-01-01T23:59:59.000Z

430

Proceedings of the heavy ion fusion workshop  

SciTech Connect

Separate abstracts were prepared for 35 of the included papers. Abstracts for 9 of the remaining papers appeared earlier in ERA. Two of the included papers were title listed only. (MOW)

Herrmannsfeldt, W.B. (ed.)

1980-09-01T23:59:59.000Z

431

Overview of US heavy ion fusion research  

E-Print Network (OSTI)

Albuquerque, NM, USA Sandia National Laboratories, USAMission Research Corporation, Sandia National Laboratories,targets are underway on the Sandia National Laboratories Z-

2004-01-01T23:59:59.000Z

432

Light nuclei production in heavy ion collisions  

E-Print Network (OSTI)

Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.

K. H. Khan; M. K. Suleymanov; Z. Wazir; E. U. Khan; Mahnaz Q. Haseeb; M. Ajaz

2009-04-14T23:59:59.000Z

433

Heavy Ion Fusion Science Virtual National Laboratory  

E-Print Network (OSTI)

.6 0.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 E / eV (E pump +E probe ) / eV /(cm/GW) 0 1 2 3 4 /(104.(Mol/l)-1.cm.2 3.4 3.6 3.8 4.0 4.2 E / eV (E pump +E probe ) / eV /(cm/GW) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 /(104.(Mol

434

Block Heavy Hitters  

E-Print Network (OSTI)

e study a natural generalization of the heavy hitters problem in thestreaming context. We term this generalization *block heavy hitters* and define it as follows. We are to stream over a matrix$A$, and report all *rows* ...

Andoni, Alexandr

2008-05-02T23:59:59.000Z

435

NUCLEAR SLAB COLLISION IN A RELATIVISTIC QUANTUM FIELD THEORY  

E-Print Network (OSTI)

Energy under Contract W-7405-ENG-43 LBL-12893 NUCLEAR SLAB COLLISION IN A RELATIVISTIC QUANTUM FIELD THEORY

Muller, K.-H.

2010-01-01T23:59:59.000Z

436

Blackbody radiation drag on a relativistically moving mirror  

E-Print Network (OSTI)

We compute the drag force on a mirror moving at relativistic velocity relative to blackbody radiation background.

N. R. Balasanyan; V. E. Mkrtchian

2009-07-14T23:59:59.000Z

437

Integral Transforms in Relativistic Quantum Constraint Mechanics  

E-Print Network (OSTI)

In relativistic quantum constraint mechanics the state of a physical system is constrained to a 3-dimensional subspace of Minkowski 4-space. Fourier transformation can be used to relate this state between constraint spaces in 4-position and 4-momentum space. It is shown that integral transforms of this nature can be carried out using Lorentz-invariant 3-dimensional constraint space coordinates such that a complete equivalence class of 4-space representations can be constructed from the transform. This method is further applied to develop a relativistic generalization of the Segal-Bargmann transformation that leads to the representation of quantum systems in a three-dimensional subspace of Bargmann 4-space.

Robert J. Ducharme

2011-01-29T23:59:59.000Z

438

Timelike Killing Fields and Relativistic Statistical Mechanics  

E-Print Network (OSTI)

For spacetimes with timelike Killing fields, we introduce a "Fermi-Walker-Killing" coordinate system and use it to prove a Liouville Theorem for an appropriate volume element of phase space for a statistical mechanical system of particles. We derive an exact relativistic formula for the Helmholtz free energy of an ideal gas and compare it, for a class of spacetimes, to its Newtonian analog, derived both independently and as the Newtonian limit of our formula. We also find the relativistic thermodynamic equation of state. Specific examples are given in Kerr spacetime.

David Klein; Peter Collas

2008-10-09T23:59:59.000Z

439

Heat conduction in relativistic neutral gases revisited  

E-Print Network (OSTI)

The kinetic theory of dilute gases to first order in the gradients yields linear relations between forces and fluxes. The heat flux for the relativistic gas has been shown to be related not only to the temperature gradient but also to the density gradient in the representation where number density, temperature and hydrodynamic velocity are the independent state variables. In this work we show the calculation of the corresponding transport coefficients from the full Boltzmann equation and compare the magnitude of the relativistic correction.

A. L. Garcia-Perciante; A. R. Mendez

2010-09-30T23:59:59.000Z

440

Heat conduction in relativistic systems: alternatives and perspectives  

E-Print Network (OSTI)

The non-equilibrium thermodynamics of relativistic systems have a rich phenomenology. The simplest phenomenon in the class of dissipative processes is that of heat. This letter presents a brief summary of the efforts made to tackle the problem of relativistic heat conduction. In particular, we focus on the multi-fluid approach to relativistic dissipation.

Lopez-Monsalvo, C S

2010-01-01T23:59:59.000Z

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441

Heat conduction in relativistic systems: alternatives and perspectives  

E-Print Network (OSTI)

The non-equilibrium thermodynamics of relativistic systems have a rich phenomenology. The simplest phenomenon in the class of dissipative processes is that of heat. This letter presents a brief summary of the efforts made to tackle the problem of relativistic heat conduction. In particular, we focus on the multi-fluid approach to relativistic dissipation.

C. S. Lopez-Monsalvo

2010-11-30T23:59:59.000Z

442

Hybrid Electron-Positron-Ion Shear Flows and Applications to Gamma-Ray Bursts  

E-Print Network (OSTI)

We present Particle-in-Cell simulation results of relativistic shear boundary layers for hybrid electron-positron-ion plasmas and discuss their potential applications to gamma-ray bursts.

Liang, Edison; Smith, Ian

2013-01-01T23:59:59.000Z

443

System-size dependence of open-heavy-flavor production in nucleus-nucleus collisions at $\\sqrt{s_{_{NN}}}$=200 GeV  

E-Print Network (OSTI)

The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy flavor production in Cu$+$Cu collisions at $\\sqrt{s_{_{NN}}}$=200 GeV through the measurement of electrons at midrapidity that originate from semileptonic decays of charm and bottom hadrons. In peripheral Cu$+$Cu collisions an enhanced production of electrons is observed relative to $p$$+$$p$ collisions scaled by the number of binary collisions. In the transverse momentum range from 1 to 5 GeV/$c$ the nuclear modification factor is $R_{AA}$$\\sim$1.4. As the system size increases to more central Cu$+$Cu collisions, the enhancement gradually disappears and turns into a suppression. For $p_T>3$ GeV/$c$, the suppression reaches $R_{AA}$$\\sim$0.8 in the most central collisions. The $p_T$ and centrality dependence of $R_{AA}$ in Cu$+$Cu collisions agree quantitatively with $R_{AA}$ in $d+$Au and Au$+$Au collisions, if compared at similar number of participating nucleons $\\langle N_{\\rm part} \\rangle$.

Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Apadula, N; Aphecetche, L; Armendariz, R; Aronson, S H; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Baumgart, S; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bickley, A A; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Chang, B S; Charvet, J -L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Cleven, C R; Cole, B A; Comets, M P; Constantin, P; Csand, M; Csrg?, T; Dahms, T; Das, K; David, G; Deaton, M B; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Dubey, A K; Durham, J M; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fields, D E; Finger, M; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H -; Hachiya, T; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hamagaki, H; Han, R; Harada, H; Hartouni, E P; Haruna, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Ichihara, T; Iinuma, H; Imai, K; Inaba, M; Inoue, Y; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kanou, H; Kawall, D; Kazantsev, A V; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, E; Kinney, E; Kiss, ; Kistenev, E; Kiyomichi, A; Klay, J; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Krl, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Lika, T; Litvinenko, A; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mao, Y; Maek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; Miake, Y; Mike, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, M; Mitchell, J T; Mitrovski, M; Morreale, A; Morrison, D P; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Norman, B E; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J -C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakata, H; Samsonov, V; Sato, S; Sawada, S; Seele, J; Seidl, R; Semenov, V; Seto, R; Sharma, D; Shein, I; Shevel, A; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Slune?ka, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarjn, P; Thomas, T L; Togawa, M; Toia, A; Tojo, J; Tomek, L; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Velkovska, J; Vrtesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zimnyi, J; Zolin, L

2013-01-01T23:59:59.000Z

444

Concepts of Hyperbolicity and Relativistic Continuum Mechanics  

E-Print Network (OSTI)

After a short introduction to the characteristic geometry underlying weakly hyperbolic systems of partial differential equations we review the notion of symmetric hyperbolicity of first-order systems and that of regular hyperbolicity of second-order systems. Numerous examples are provided, mainly taken from nonrelativistic and relativistic continuum mechanics.

Robert Beig

2004-11-18T23:59:59.000Z

445

Relativistic electron beam plasma heating experiment  

SciTech Connect

An intense (5 x 10/sup 5/ Amp/cm/sup 2/), relativistic (5 MeV), electron beam will be used to investigate the heating of small volumes (approx. 5 to 10 cm/sup 3/) of dense plasma (10/sup 17/ to 10/sup 18/ electrons/cm/sup 3/) to kilovolt temperatures via the electrostatic two-stream instability.

Montgomery, M.D.; Parker, J.V.

1980-04-01T23:59:59.000Z

446

Relativistic atomic physics at the SSC  

SciTech Connect

This report discusses the following proposed work for relativistic atomic physics at the Superconducting Super Collider: Beam diagnostics; atomic physics research; staffing; education; budget information; statement concerning matching funds; description and justification of major items of equipment; statement of current and pending support; and assurance of compliance.

NONE

1990-12-31T23:59:59.000Z

447

Fully relativistic calculation of nuclear magnetic shieldings and indirect nuclear spin-spin couplings in group-15 and -16 hydrides  

Science Conference Proceedings (OSTI)

Fully relativistic calculations of the isotropic and anisotropic parts of both indirect nuclear spinspin couplings 1 J(X- H ) and 2 J( H-H ) and nuclear magnetic shieldings ?(X) and ?(H) for the group-15 and -16 hydrides are presented. Relativistic calculations were performed with DiracFock wave functions and the random phase approximation method. Results are compared to its nonrelativistic counterpart. Paramagnetic and diamagnetic contributions to the nuclear magnetic shielding constants are also reported. We found very large relativistic corrections to both properties in the sixth-