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Sample records for alkali heavy-ion reaction

  1. Chemistry of heavy ion reactions

    SciTech Connect

    Hoffman, D.C.

    1988-10-01

    The use of heavy ions to induce nuclear reactions was reported as early as 1950. Since that time it has been one of the most active areas of nuclear research. Intense beams of ions as heavy as uranium with energies high enough to overcome the Coulomb barriers of even the heaviest elements are available. The wide variety of possible reactions gives rise to a multitude of products which have been studied by many ingenious chemical and physical techniques. Chemical techniques have been of special value for the separation and unequivocal identification of low yield species from the plethora of other nuclides present. Heavy ion reactions have been essential for the production of the trans-Md elements and a host of new isotopes. The systematics of compound nucleus reactions, transfer reactions, and deeply inelastic reactions have been elucidated using chemical techniques. A review of the variety of chemical procedures and techniques which have been developed for the study of heavy ion reactions and their products is given. Determination of the chemical properties of the trans-Md elements, which are very short-lived and can only be produced an ''atom-at-a-time'' via heavy ion reactions, is discussed. 53 refs., 19 figs.

  2. Resonant structures in heavy-ion reactions

    SciTech Connect

    Sanders, S.J.; Henning, W.; Ernst, H.; Geesaman, D.F.; Jachcinski, C.; Kovar, D.G.; Paul, M.; Schiffer, J.P.

    1980-01-01

    An investigation of heavy-ion resonance structures using the /sup 24/Mg(/sup 16/O, /sup 12/C)/sup 28/Si reaction is presented. The data are analyzed in the context of Breit-Wigner resonances added to a direct-reaction background.

  3. Dynamics of fission and heavy ion reactions

    SciTech Connect

    Nix, J.R.; Sierk, A.J.

    1984-05-01

    Recent advances in a unified macroscopic-microscopic description of large-amplitude collective nuclear motion such as occurs in fission and heavy ion reactions are discussed. With the goal of finding observable quantities that depend upon the magnitude and mechanism of nuclear dissipation, one-body dissipation and two-body viscosity within the framework of a generalized Fokker-Planck equation for the time dependence of the distribution function in phase space of collective coordinates and momenta are considered. Proceeding in two separate directions, the generalized Hamilton equations of motion for the first moments of the distribution function with a new shape parametrization and other technical innovations are first solved. This yields the mean translational fission-fragment kinetic energy and mass of a third fragment that sometimes forms between the two end fragments, as well as the energy required for fusion in symmetric heavy-ion reactions and the mass transfer and capture cross section in asymmetric heavy-ion reactions. In a second direction, we specialize to an inverted-oscillator fission barrier and use Kramers' stationary solution to calculate the mean time from the saddle point to scission for a heavy-ion-induced fission reaction for which experimental information is becoming available. 25 references.

  4. Crystal blocking in heavy ion reactions

    SciTech Connect

    del Campo, J.G.

    1986-01-01

    The crystal blocking technique, used to measure very short lifetime (10/sup -18/ sec), was developed during the 1960's primarily in connection with the study of the channeling effect. Early blocking lifetime measurements involved light ion resonance reactions yielding typical lifetime values down to the order of 10/sup -17/ sec. Recently, studies of heavy-ion induced fission and fusion have extended the technique into the 10/sup -18/ to 10/sup -19/ sec scale. In this work measurements of fusion for /sup 16/O + Ge and deep inelastic reactions for /sup 28/Si + Ge are presented for bombarding energies around 8 nucleon. Also measurements of the projectile fragmenatation of 44 MeV/nucleon /sup 40/Ar + Ge are discussed. In all reactions studied the presence of particle evaporation is the dominant mechanism that determines the reaction times of about 10/sup -18/ sec extracted with the blocking technique. 16 refs., 9 figs.

  5. Prompt processes in heavy ion reactions

    SciTech Connect

    Blann, M.; Remington, B.A.

    1987-12-01

    We test a relaxation model based on two body nucleon-nucleon scattering processes to interpret phenomena observed in heavy ion reactions. We use the Boltzmann Master Equation to accomplish this. By assuming that the projectile nucleons partition the total excitation with equal a-priori probability of all configurations, we are able to reproduce several sets of neutron spectra from /sup 20/Ne and /sup 12/C induced reactions on /sup 165/Ho and from reactions of /sup 40/Ar or /sup 40/Ca. We point out ambiguities in deducing angle-integrated energy spectra from double differential spectra. With no additional free parameters, our model successfully reproduces a large body of high energy ..gamma..-ray spectra by assuming an incoherent n-p-bremsstrahlung mechanism. 45 refs., 13 figs.

  6. Heavy Ion Reaction Modeling for Hadrontherapy Applications

    SciTech Connect

    Cerutti, F.; Ferrari, A.; Enghardt, W.; Gadioli, E.; Mairani, A.; Parodi, K.; Sommerer, F.

    2007-10-26

    A comprehensive and reliable description of nucleus-nucleus interactions represents a crucial need in different interdisciplinary fields. In particular, hadrontherapy monitoring by means of in-beam positron emission tomography (PET) requires, in addition to measuring, the capability of calculating the activity of {beta}{sup +}-decaying nuclei produced in the irradiated tissue. For this purpose, in view of treatment monitoring at the Heidelberg Ion Therapy (HIT) facility, the transport and interaction Monte Carlo code FLUKA is a promising candidate. It is provided with the description of heavy ion reactions at intermediate and low energies by two specific event generators. In-beam PET experiments performed at GSI for a few beam-target combinations have been simulated and first comparisons between the measured and calculated {beta}{sup +}-activity are available.

  7. Recent Progress in Isospin Physics with Heavy-Ion Reactions

    SciTech Connect

    Chen Liewen; Ko, Che Ming; Li Baoan

    2008-11-11

    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 future high energy radioactive beams. Implications of these results for the nuclear effective interactions are also discussed.

  8. Dynamical processes in heavy ion reactions

    SciTech Connect

    Blann, M.; Remington, B.A.

    1988-07-25

    In this report I review the physical assumptions of the Boltzmann Master Equation (BME). Comparisons of the model with experimental neutron spectra gated on evaporation residues for a range of incident projectile energies and masses are presented; next, I compare n spectra gated on projectile-like fragments, followed by comparisons with ungated, inclusive proton spectra. I will then consider secondary effects from the nucleon-nucleon processes involved in the heavy ion relaxation processes, specifically the high energy ..gamma..-rays which have been observed at energies up to 140 MeV in collisions of heavy ions of 20/endash/84 MeV/..mu... Another secondary effect, subthreshold pion production, was covered in the XVII School and will not be repeated. 39 refs., 16 figs.

  9. Thermodynamical Aspects in Heavy Ion Reactions

    NASA Astrophysics Data System (ADS)

    Bruno, M.; Cannata, F.; D'Agostino, M.; de Sanctis, J.; Fabbri, S.; Fuschini, E.; Geraci, E.; Guiot, B.; Vannini, G.; Verondini, E.; Gulminelli, F.; Chomaz, Ph.; Casini, G.; Chiari, M.; Nannini, A.; Barlini, S.; Gramegna, F.; Kravchuk, V.; Lanchais, A.; Vannucci, L.; Moroni, A.; Ordine, A.; Abbondanno, U.; Margagliotti, G. V.

    2005-12-01

    The excited nuclear systems formed in heavy ion collisions can be studied from a thermodynamical point of view. Charged finite systems have different behaviors with respect to infinite ones. After experimental selection of such equilibrated systems the extraction of thermodynamic coordinates is performed. Different signals compatible with a liquid-gas phase transition have been obtained. In particular a bimodal distribution of the asymmetry between the first two heaviest fragments is presented. Abnormally large fluctuations, which in thermodynamic equilibrium are associated to a negative branch of the heat capacity give indications of a first order phase transition. Perspectives for new generation experiments are indicated.

  10. Hydrodynamic approaches in relativistic heavy ion reactions

    NASA Astrophysics Data System (ADS)

    Derradi de Souza, R.; Koide, T.; Kodama, T.

    2016-01-01

    We review several facets of the hydrodynamic description of the relativistic heavy ion collisions, starting from the historical motivation to the present understandings of the observed collective aspects of experimental data, especially those of the most recent RHIC and LHC results. In this report, we particularly focus on the conceptual questions and the physical foundations of the validity of the hydrodynamic approach itself. We also discuss recent efforts to clarify some of the points in this direction, such as the various forms of derivations of relativistic hydrodynamics together with the limitations intrinsic to the traditional approaches, variational approaches, known analytic solutions for special cases, and several new theoretical developments. Throughout this review, we stress the role of course-graining procedure in the hydrodynamic description and discuss its relation to the physical observables through the analysis of a hydrodynamic mapping of a microscopic transport model. Several questions to be answered to clarify the physics of collective phenomena in the relativistic heavy ion collisions are pointed out.

  11. Probing the nuclear structure with heavy-ion reactions

    SciTech Connect

    Broglia, R.A.

    1982-01-01

    Nuclei display distortions in both ordinary space and in gauge space. It is suggested that it is possible to learn about the spatial distribution of the Nilsson orbitals and about the change of the pairing gap with the rotational frequency through the analysis of one- and two-nucleon transfer reactions induced in heavy-ion collisions.

  12. Mechanism of dissipation in heavy-ion reactions

    SciTech Connect

    Nix, J.R.; Sierk, A.J.

    1987-01-01

    We discuss a new surface-plus-window mechanism for the conversion of nuclear collective energy into internal degrees of freedom at intermediate excitation energies. This novel dissipation mechanism, which results from the long mean free path of nucleons inside a nucleus, involves interactions of either one or two nucleons with the moving nuclear surface and also, for dumbbell-like shapes encountered in heavy-ion reactions and fission, the transfer of nucleons through the window separating the two portions of the system. To illustrate the effect of surface-plus-window dissipation on heavy-ion-fusion reactions we present dynamical calculations for values of the dissipation strength corresponding to 27% and 100% of the Swiatecki wall-formula value, as well as for no dissipation. In addition to dynamical thresholds for compound-nucleus formation in heavy-ion reactions, our new picture describes such other phenomena as experimental mean fission-fragment kinetic energies for the fission of nuclei throughout the periodic system, enhancement in neutron emission prior to fission, short scission-to-scission times in sequential ternary fission, widths of mass and charge distributions in deep-inelastic heavy-ion reactions, and widths of isoscalar giant quadrupole and giant octupole resonances. 32 refs., 2 figs.

  13. Momentum transfer in relativistic heavy ion charge-exchange reactions

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W.; Khan, F.; Khandelwal, G. S.

    1991-01-01

    Relativistic heavy ion charge-exchange reactions yield fragments (Delta-Z = + 1) whose longitudinal momentum distributions are downshifted by larger values than those associated with the remaining fragments (Delta-Z = 1, -2,...). Kinematics alone cannot account for the observed downshifts; therefore, an additional contribution from collision dynamics must be included. In this work, an optical model description of collision momentum transfer is used to estimate the additional dynamical momentum downshift. Good agreement between theoretical estimates and experimental data is obtained.

  14. Proximity potential for heavy ion reactions on deformed nuclei

    SciTech Connect

    Baltz, A. J.; Bayman, B. F.

    1982-01-01

    The usual treatment of the deformed optical model for analysis of heavy ion induced inelastic scattering data involves a deformed (target) radius, a spherical (projectile) radius and a potential strength dependent on the surface separation along the line between the two centers. Several authors using various approaches have shown that this center line potential is geometrically inadequate especially for description of higher L deformation parameters probed in heavy ion induced inelastic scattering experiments. A quantitatively adequate form of the deformed proximity potential suitable for use with a coupled channels reaction code in the analysis of inelastic scattering data above the Coulomb barrier is described. A major objective is to be able to extract reliably higher deformed multipole moments from such data. The deformed potential calculated in the folding model will serve as a geometrically exact benchmark to evaluate the accuracy of the proximity potential prescriptions. (WHK)

  15. Numerical simulations of relativistic heavy-ion reactions

    NASA Astrophysics Data System (ADS)

    Daffin, Frank Cecil

    Bulk quantities of nuclear matter exist only in the compact bodies of the universe. There the crushing gravitational forces overcome the Coulomb repulsion in massive stellar collapses. Nuclear matter is subjected to high pressures and temperatures as shock waves propagate and burn their way through stellar cores. The bulk properties of nuclear matter are important parameters in the evolution of these collapses, some of which lead to nucleosynthesis. The nucleus is rich in physical phenomena. Above the Coulomb barrier, complex interactions lead to the distortion of, and as collision energies increase, the destruction of the nuclear volume. Of critical importance to the understanding of these events is an understanding of the aggregate microscopic processes which govern them. In an effort to understand relativistic heavy-ion reactions, the Boltzmann-Uehling-Uhlenbeck (Ueh33) (BUU) transport equation is used as the framework for a numerical model. In the years since its introduction, the numerical model has been instrumental in providing a coherent, microscopic, physical description of these complex, highly non-linear events. This treatise describes the background leading to the creation of our numerical model of the BUU transport equation, details of its numerical implementation, its application to the study of relativistic heavy-ion collisions, and some of the experimental observables used to compare calculated results to empirical results. The formalism evolves the one-body Wigner phase-space distribution of nucleons in time under the influence of a single-particle nuclear mean field interaction and a collision source term. This is essentially the familiar Boltzmann transport equation whose source term has been modified to address the Pauli exclusion principle. Two elements of the model allow extrapolation from the study of nuclear collisions to bulk quantities of nuclear matter: the modification of nucleon scattering cross sections in nuclear matter, and the

  16. Studies of complex fragment emission in heavy ion reactions

    SciTech Connect

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

    1992-01-01

    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.

  17. Theoretical aspects of high-energy heavy-ion reactions

    SciTech Connect

    Wong, Cheuk-Yin

    1987-01-01

    An elementary introduction is given to the subject of nucleus-nucleus collisions at high energies. It begins with a discussion on the relevant kinematic variables to establish the language for these collisions. It examines the question of particle production and the characteristics of the loss of baryon energy in an inelastic nucleon-nucleon collision. The geometrical aspect of a nucleus-nucleus collision is then described in terms of the Glauber multiple-collision model. As the theory of relativistic heavy-ion collision has not yet reached a stage whereby the dynamics can be examined from a fundamental theory, various phenomenological models have been proposed. The assumptions used in various models are described. Future use of relativistic heavy-ion collisions to study the quark-gluon plasma is briefly discussed.

  18. STOPPING AND BARYON TRANSPORT IN HEAVY ION REACTIONS.

    SciTech Connect

    VIDEBAEK, F.

    2005-02-05

    In this report I will give an experimental overview on nuclear stopping in hadron collisions, and relate observations to understanding of baryon transport. Baryon number transport is not only evidenced via net-proton distributions but also by the enhancement of strange baryons near mid-rapidity. Although the focus is on high-energy data obtained from pp and heavy ions from RHIC, relevant data from SPS and ISR will be considered. A discussion how the available data at higher energy relates and gives information on baryon junction, quark-diquark breaking will be made.

  19. Population of high spin states in very heavy ion transfer reactions. The experimental evidence

    SciTech Connect

    Guidry, M.W.

    1985-01-01

    Transfer reactions have been studied for some time with light heavy ions such as oxygen. Although states of spin I approx.10 h are sometimes populated in such reactions, it is assumed that collective excitation is small, and the transferred particles are responsible for the angular momentum transfer. In this paper we will discuss a qualitatively different kind of transfer reaction using very heavy ions (A greater than or equal to 40). In these reactions the collective excitation in both the entrance and exit channels is strong, and there may be appreciable angular momentum transfer associated with inelastic excitation. 12 refs., 13 figs.

  20. [Reaction mechanism studies of heavy ion induced nuclear reactions]. Annual progress report, [January 1992--February 1993

    SciTech Connect

    Mignerey, A.C.

    1993-02-01

    Completed work is summarized on the topics of excitation energy division in deep-inelastic reactions and the onset of multifragmentation in La-induced reactions at E/A = 45 MeV. Magnetic fields are being calculated for the PHOBOS detector system, a two-arm multiparticle spectrometer for studying low-transverse-momentum particles produced at the Relativistic Heavy Ion Collider. The Maryland Forward Array is being developed for detection of the reaction products from very peripheral collisions; it consists of two individual units of detectors: the annular silicon detector in front and the plastic phoswich detector at back.

  1. Study of Heavy Ion Fusion Reaction of NICKEL-58 and Magnesium at 11 Mev/nucleon

    NASA Astrophysics Data System (ADS)

    Shea, Jing Ye.

    This thesis presents a study of the heavy ion fusion reaction in which a ^{58} Ni projectile bombards a ^{24 }Mg target at 11 MeV/nucleon. The incident projectile energy was purposefully chosen so as the system studied to be at the onset of the more complex and interesting phenomenon of incomplete fusion. The physics motivation is to probe the central collision of a heavy, energetic, and asymmetric system by means of both inclusive and exclusive experimental measurements. The experiment was performed at HHIRF (Holifield Heavy Ion Research Facility) by using the coupled accelerators at Oak Ridge National Laboratory. The reaction products were measured by the new "HILI-Ring" large solid angle detector system at Oak Ridge National Laboratory. The thesis discusses the physics motivation and the systematics of heavy ion fusion reactions. Details of the design and construction of a new CsI(Tl) Ring detector is given. Since this is the first such study performed on the Heavy Ion Light Ion (HILI) detector, an extensive discussion of the calibration procedures and the data reduction methods are given. The fusion reaction data were analyzed in both inclusive and exclusive modes with the result that a valuable new perspective on the deconvolution of the reaction mechanism has been achieved.

  2. Dispersion relation approach to sub-barrier heavy-ion fusion reactions

    SciTech Connect

    Franzin, V.L.M.; Hussein, M.S.

    1988-11-01

    We discuss the conditions under which the dispersion relation technique, extensively employed in the context of elastic scattering, can be used in the analysis of heavy-ion fusion reactions. General unitarity defect arguments are used for this purpose. With the aid of an inverse dispersion relation, which gives the imaginary part of the fusion inclusive polarization potential in terms of the principal part integral involving the real part of the inclusive polarization potential, the sub-barrier fusion of heavy ions is discussed. The system /sup 16/O+/sup A/Sm is taken as an example.

  3. [Use of photonuclear reactions for studying the biological action of slow heavy ions].

    PubMed

    Kapchigashev, S P

    1984-01-01

    Since ranges of low-energy heavy ions are too little the study of their action on cells is only possible using indirect irradiation, for instance, with neurons which form low--energy heavy ions uniformly inside a cell. In our studies we used photonuclear reactions which occur upon irradiation of a bio-object with high energy bremsstrahlung. The advantage of this method over the method based on the usage of neutrons has been demonstrated. The data are submitted obtained after exposure of yeast cells to photonuclear products. PMID:6324271

  4. A comparison of total reaction cross section models used in particle and heavy ion transport codes

    NASA Astrophysics Data System (ADS)

    Sihver, Lembit; Lantz, M.; Takechi, M.; Kohama, A.; Ferrari, A.; Cerutti, F.; Sato, T.

    To be able to calculate the nucleon-nucleus and nucleus-nucleus total reaction cross sections with precision is very important for studies of basic nuclear properties, e.g. nuclear structure. This is also of importance for particle and heavy ion transport calculations because, in all particle and heavy ion transport codes, the probability function that a projectile particle will collide within a certain distance x in the matter depends on the total reaction cross sections. Furthermore, the total reaction cross sections will also scale the calculated partial fragmentation cross sections. It is therefore crucial that accurate total reaction cross section models are used in the transport calculations. In this paper, different models for calculating nucleon-nucleus and nucleus-nucleus total reaction cross sections are compared and discussed.

  5. Deduction of compound nucleus formation probability from the fragment angular distributions in heavy-ion reactions

    NASA Astrophysics Data System (ADS)

    Yadav, C.; Thomas, R. G.; Mohanty, A. K.; Kapoor, S. S.

    2015-07-01

    The presence of various fissionlike reactions in heavy-ion induced reactions is a major hurdle in the path to laboratory synthesis of heavy and super-heavy nuclei. It is known that the cross section of forming a heavy evaporation residue in fusion reactions depends on the three factors—the capture cross section, probability of compound nucleus formation PCN, and the survival probability of the compound nucleus against fission. As the probability of compound nucleus formation, PCN is difficult to theoretically estimate because of its complex dependence on several parameters; attempts have been made in the past to deduce it from the fission fragment anisotropy data. In the present work, the fragment anisotropy data for a number of heavy-ion reactions are analyzed and it is found that deduction of PCN from the anisotropy data also requires the knowledge of the ratio of relaxation time of the K degree of freedom to pre-equilibrium fission time.

  6. HIBRA: A computer code for heavy ion binary reaction analysis employing ion track detectors

    NASA Astrophysics Data System (ADS)

    Jamil, Khalid; Ahmad, Siraj-ul-Islam; Manzoor, Shahid

    2016-01-01

    Collisions of heavy ions many times result in production of only two reaction products. Study of heavy ions using ion track detectors allows experimentalists to observe the track length in the plane of the detector, depth of the tracks in the volume of the detector and angles between the tracks on the detector surface, all known as track parameters. How to convert these into useful physics parameters such as masses, energies, momenta of the reaction products and the Q-values of the reaction? This paper describes the (a) model used to analyze binary reactions in terms of measured etched track parameters of the reaction products recorded in ion track detectors, and (b) the code developed for computing useful physics parameters for fast and accurate analysis of a large number of binary events. A computer code, HIBRA (Heavy Ion Binary Reaction Analysis) has been developed both in C++ and FORTRAN programming languages. It has been tested on the binary reactions from 12.5 MeV/u 84Kr ions incident upon U (natural) target deposited on mica ion track detector. The HIBRA code can be employed with any ion track detector for which range-velocity relation is available including the widely used CR-39 ion track detectors. This paper provides the source code of HIBRA in C++ language along with input and output data to test the program.

  7. Multimodal Fission in Heavy-Ion Induced Reactions

    SciTech Connect

    Pokrovskiy, I. V.; Bogachev, A. A.; Iitkis, M. G.; Iitkis, J. M.; Kondratiev, N. A.; Kozulin, E. M.; Dorvaux, O.; Rowley, N.; Schmitt, Ch.; Stuttge, L.

    2006-08-14

    Mass, energy and folding angle distributions of the fission fragments as well as multiplicities of neutron and gamma-quanta emissions accompanying the fission process were measured for fission of 226Th, 227Pa and 234Pu compound nuclei produced in reactions with 18O and 26Mg projectiles over a wide energy range. Data were analyzed with respect to the presence of fission modes. Asymmetric fission was observed even at very high initial excitation for all the measured systems. The so-called fission mode S1 (caused by the proton shell Z{approx}50 and neutron shell N{approx}82 in heavy fragment) was found to be dominant in asymmetric fission of 234Pu. Reactions with not full linear momentum transfer were observed in the folding spectra for all the measured systems.

  8. Statistics at work in heavy-ion reactions

    SciTech Connect

    Moretto, L.G.

    1982-07-01

    In the first part special aspects of the compound nucleus decay are considered. The evaporation of particles intermediate between nucleons and fission fragments is explored both theoretically and experimentally. The limitations of the fission decay width expression obtained with the transition state method are discussed, and a more general approach is proposed. In the second part the process of angular momentum transfer in deep inelastic reactions is considered. The limit of statistical equilibrium is studied and specifically applied to the estimation of the degree of alignment of the fragment spins. The magnitude and alignment of the transferred angular momentum is experimentally determined from sequentially emitted alpha, gamma, and fission fragments.

  9. Calculation of cross sections for binary reactions between heavy ion projectiles and heavy actinide targets

    SciTech Connect

    Hoffman, D.C.; Hoffman, M.M.

    1990-11-01

    The computer program, described in this report, is identified as PWAVED5. It was developed to calculate cross sections for nucleon transfer reactions in low energy heavy ion bombardments. The objective was to calculate cross sections that agree with experimental results for ions of different charge and mass and to develop a predictive capability. It was undertaken because previous heavy ion calculations, for which programs were readily available, appeared to focus primarily on reactions resulting in compound nucleus formation and were not particularly applicable to calculations of binary reaction cross sections at low interaction energies. There are to principal areas in which this computation differs from several other partial wave calculations of heavy-ion reaction cross sections. First, this program is designed specifically to calculate cross sections for nucleon exchange interactions and to exclude interactions that are expected to result in fusion of the two nuclei. A second major difference in this calculation is the use of a statistical distribution to assign the total interaction cross section to individual final mass states.

  10. {gamma} spectroscopy around doubly magic {sup 48}Ca by heavy-ion transfer reactions

    SciTech Connect

    Leoni, Silvia

    2012-10-20

    {gamma} spectroscopy of neutron-rich nuclei around {sup 48}Ca is performed by the heavy-ion transfer reaction {sup 48}Ca on {sup 64}Ni at 282 MeV, with the PRISMA-CLARA setup at Legnaro Laboratory. Angular distributions, polarizations and lifetimes analysis probe spin and parities of several excited states, shading lights on their configuration. In the one neutron transfer channels, {sup 49}Ca and {sup 47}Ca, states arising by coupling a single particle to the 3{sup -} phonon of {sup 48}Ca are observed, showing the robustness of nuclear collectivity in rather light systems. The work demonstrates the feasibility of complete in-beam {gamma}-spectroscopy with heavy-ion transfer reactions and provides a method that can be further exploited in the future with heavy targets and radioactive beams.

  11. Heavy-ion reactions near the Coulomb barrier

    SciTech Connect

    Esbensen, H.; Rehm, K.E.; Jiang, C.L.

    1995-08-01

    Fusion reactions between different Kr and Ni isotopes were measured recently at ATLAS. We performed coupled-channels calculations and made comparisons to the measurements. Such calculations become increasingly difficult for heavy, soft nuclei due to strong couplings and the importance of higher-order, multi-step processes. The calculations were made possible by adopting the so-called rotating frame approximation, and they included one- and two-phonon excitations of the low-lying 2{sup +} and 3{sup -} states in both the projectile and the target. These calculations reproduced quite accurately the measured fusion cross sections for a beam of {sup 86}Kr. Some discrepancies remain for the much softer {sup 78}Kr nucleus; the calculations were clearly much more sensitive to higher-order processes in this case. In particular, it was important to implement the correct coupling strength and excitation energy for the soft, one- to two-phonon quadrupole transition in {sup 78}Kr, which differs significantly from the vibrational limit. This work was performed in collaboration with the experimentalists and was submitted for publication.

  12. Actinide Production in the Reaction of Heavy Ions withCurium-248

    SciTech Connect

    Moody, K.J.

    1983-07-01

    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.

  13. Multifragment azimuthal correlation functions: Probes for reaction dynamics in collisions of intermediate energy heavy ions

    SciTech Connect

    Lacey, R.A.; Elmaani, A.; Lauret, J.; Li, T.; Bauer, W.; Craig, D.; Cronqvist, M.; Gualtieri, E.; Hannuschke, S.; Reposeur, T.; Vander Molen, A.; Westfall, G.D.; Wilson, W.K.; Winfield, J.S.; Yee, J.; Yennello, S.; Nadasen, A.; Tickle, R.S.; Norbeck, E. National Superconducting Cyclotron Laboratory Department of Physics, Michigan State University, East Lansing, Michigan 48824-1321 Department of Physics, University of Michigan at Dearborn, Dearborn, Michigan 48128 Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1120 Department of Physics, University of Iowa, Iowa City, Iowa 52242 )

    1993-03-01

    Multifragment azimuthal correlation functions have been measured as a function of beam energy and impact parameter for the Ar+Sc system ([ital E]/[ital A]=35 to 115 MeV). The observed azimuthal correlation functions---which do not require corrections for dispersion of the reaction plane---exhibit strong asymmetries which are dependent on impact parameter and beam energy. Rotational collective motion and flow seem to dominate the correlation functions at low beam energies. It is proposed that multifragment azimuthal correlation functions can provide a useful probe for intermediate energy heavy ion reaction dynamics.

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

    SciTech Connect

    Moller, Peter; Iwamoto, A; Ichikawa, I

    2010-09-10

    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.

  15. Recent developments in heavy-ion fusion reactions around the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Hagino, K.; Rowley, N.; Yao, J. M.

    2016-06-01

    The nuclear fusion is a reaction to form a compound nucleus. It plays an important role in several circumstances in nuclear physics as well as in nuclear astrophysics, such as synthesis of superheavy elements and nucleosynthesis in stars. Here we discuss two recent theoretical developments in heavy-ion fusion reactions at energies around the Coulomb barrier. The first topic is a generalization of the Wong formula for fusion cross sections in a single-channel problem. By introducing an energy dependence to the barrier parameters, we show that the generalized formula leads to results practically indistinguishable from a full quantal calculation, even for light symmetric systems such as 12C+12C, for which fusion cross sections show an oscillatory behavior. We then discuss a semi-microscopic modeling of heavy-ion fusion reactions, which combine the coupled-channels approach to the state-of-the-art nuclear structure calculations for low-lying collective motions. We apply this method to subbarrier fusion reactions of 58Ni+58Ni and 40Ca+58Ni systems, and discuss the role of anharmonicity of the low-lying vibrational motions.

  16. Present status of coupled-channels calculations for heavy-ion subbarrier fusion reactions

    NASA Astrophysics Data System (ADS)

    Hagino, K.; Yao, J. M.

    2016-05-01

    The coupled-channels method has been a standard tool in analyzing heavy-ion fusion reactions at energies around the Coulomb barrier. We investigate three simplifications usually adopted in the coupledchannels calculations. These are i) the exclusion of non-collective excitations, ii) the assumption of coordinate independent coupling strengths, and iii) the harmonic oscillator approximation for multiphonon excitations. In connection to the last point, we propose a novel microscopic method based on the beyond-mean-field approach in order to take into account the anharmonic effects of collective vibrations.

  17. Preequilibrium neutron emission in heavy ion reaction: Mean field effect and multiple emission

    NASA Astrophysics Data System (ADS)

    Paul, Sabyasachi; Nandy, Maitreyee; Mohanty, A. K.; Gambhir, Y. K.

    2016-09-01

    Effects of nuclear mean field and of multiple preequilibrium (PEQ) emission on double differential neutron multiplicity distribution from heavy ion reactions (12C+165Ho and 20Ne+165Ho ) at 10-30 MeV/u have been investigated in the framework of the semiclassical formalism for heavy ion reaction (henceforth termed "HION") developed earlier. HION follows the equilibration of a target+projectile composite system through the kinematics of two-body scattering. In the present work nuclear density distribution in the composite system is estimated in the relativistic mean field (RMF) approach. The nucleon-nucleon collision rates and subsequently the nucleon emission probability are calculated from this density distribution. A second approach based on a semiphenomenological formalism is also used for nuclear density distribution. Energy-angle distribution of neutron multiplicities calculated with this modified HION model coupled with multiple PEQ emission could reproduce the measured data of earlier workers in the projectile energy range of 10-30 MeV/u.

  18. Excitation energy sharing in binary peripheral heavy ion reactions at Fermi energies

    NASA Astrophysics Data System (ADS)

    Piantelli, S.; Mangiarotti, A.; Maurenzig, P. R.; Olmi, A.; Bardelli, L.; Bini, M.; Casini, G.; Pasquali, G.; Poggi, G.; Stefanini, A. A.

    2008-12-01

    Evidence for the dependence of excitation energy sharing between two heavy remnants on the difference in the lost mass in two-body peripheral heavy ion reactions at Fermi energy is presented, based on experimental results for the reactions Nb93+Sn116, Sn116+Nb93, and Nb93+Nb93 at 38A MeV. An observable based on the experimental velocities of the heavy residues is used to select reactions with equal preevaporative masses of projectile-like fragments and target-like fragments. The excitation energy, evaluated by means of a complete average calorimetry, is found to be larger for the nucleus that finally retains a larger part of the hot interaction region.

  19. Competition between fusion and quasi-fission in heavy ion induced reactions

    SciTech Connect

    Back, B.B.

    1986-09-01

    Quantitative analyses of angular distributions and angle-mass correlations have been applied to the U + Ca reaction to obtain upper limit estimates for the cross sections for complete fusion near or below the interaction barrier. Extrapolating to the systems Ca + Cm and Ca + Es using the well established scaling properties of the extra push model, an estimate of the cross sections relevant to the efforts of synthesizing super-heavy elements in the region Z = 116 and N = 184 via heavy-ion fusion reactions are obtained. A simple evaporation calculation using properties of the super heavy elements shows that the failure to observe super-heavy elements with the Ca + Cm reaction is consistent with estimates of the complete fusion process. 33 refs., 9 figs., 1 tab.

  20. Actinide production in the reaction of heavy ions with curium-248

    SciTech Connect

    Moody, K.J.

    1983-01-01

    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/Kr and /sup 86/O, /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. A preliminary, unsuccessful attempt to isolate /sup 247/Pu is outlined. The absolute ..gamma.. ray intensities from /sup 251/Bk decay, necessary for calculating the /sup 251/Bk cross section, are also determined.

  1. Abrasion-ablation model for neutron production in heavy ion reactions

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.; Townsend, Lawrence W.

    1995-01-01

    In heavy ion reactions, neutron production at forward angles is observed to occur with a Gaussian shape that is centered near the beam energy and extends to energies well above that of the beam. This paper presents an abrasion-ablation model for making quantitative predictions of the neutron spectrum. To describe neutrons produced from the abrasion step of the reaction where the projectile and target overlap, the authors use the Glauber model and include effects of final-state interactions. They then use the prefragment mass distribution from abrasion with a statistical evaporation model to estimate the neutron spectrum resulting from ablation. Measurements of neutron production from Ne and Nb beams are compared with calculations, and good agreement is found.

  2. A new approach to the kinematic coincidence method in heavy ion reactions

    NASA Astrophysics Data System (ADS)

    Casini, G.; Maurenzig, P. R.; Olmi, A.; Stefanini, A. A.

    1989-05-01

    A new approach to the kinematic coincidence method (KCM) is proposed, which makes use of the whole kinematic information of heavy ion experiments in a self-consistent way. It takes advantage of the overdetermination of the measurement yielding not only solutions for the primary masses of the fragments, but also "improved values" for their velocity vectors. A statistical variable, Δν, indicates to what extent the secondary quantities violate the kinematics of the reaction. The ability of the present approach to reproduce the primary quantities of a binary or ternary reaction is compared with that of older approaches on the basis of realistic Monte Carlo simulations. The background of incompletely detected events of higher multiplicity can be effectively subtracted using the results of the present analysis.

  3. [Reaction mechanism studies of heavy ion induced nuclear reactions]. [Dept. of Chemistry and Biochemistry, Univ. of Maryland, College Park, Maryland

    SciTech Connect

    Mignerey, A.C.

    1993-02-01

    Completed work is summarized on the topics of excitation energy division in deep-inelastic reactions and the onset of multifragmentation in La-induced reactions at E/A = 45 MeV. Magnetic fields are being calculated for the PHOBOS detector system, a two-arm multiparticle spectrometer for studying low-transverse-momentum particles produced at the Relativistic Heavy Ion Collider. The Maryland Forward Array is being developed for detection of the reaction products from very peripheral collisions; it consists of two individual units of detectors: the annular silicon detector in front and the plastic phoswich detector at back.

  4. Delta excitations and shell-model information in heavy-ion, charge-exchange reactions

    NASA Technical Reports Server (NTRS)

    Deutchman, P. A.; Maung, K. M.; Norbury, J. W.; Rasmussen, J. O.; Townsend, L. W.

    1986-01-01

    We calculate total cross sections for coherent pion production using localized plane-wave approximations for the shell-structure of valence nucleons that are excited to delta particles in the intermediate state in the (12C, 12B) and (12C, 12N) charge-exchange, heavy-ion reactions. We find comparable agreement to projectile downshift data for 12C(12C, 12B)12N. Then we improve the formalism by replacing the localized plane wave bound states with harmonic oscillator states which are imbedded in a multipole expansion approach and calculate pion differential cross sections to test for the sensitivity of the spectra to the single-particle mass parameter.

  5. Intimations of neck formation in heavy-ion subbarrier fusion reactions

    SciTech Connect

    Stelson, P.H.

    1990-07-01

    Since the observed fusion cross sections for collisions between heavy ions at subbarrier energies are orders of magnitude larger than would be expected for barrier tunnelling, one is faced with the task of identifying the basic force which is strong enough to overcome the strong Coulomb force and bring about fusion. The two possibilities seem to be excursions of the nuclear surface (and strong nuclear force) due to collective motions of the colliding nuclei and formation of a neck of nuclear matter. The first possibility has received the most attention. However, the systematics of fusion cross sections suggest neck formation is playing an important role. Neck formation can also result in a reseparation of the composite system and we review the experimental information on these reactions at barrier and subbarrier energies. 15 refs., 18 figs.

  6. Multifragmentation in intermediate energy {sup 129}Xe-induced heavy-ion reactions

    SciTech Connect

    Tso, Kin

    1996-05-01

    The {sup 129}Xe-induced reactions on {sup nat}Cu, {sup 89}Y, {sup 165}Ho, and {sup 197}Au at bombarding energies of E/A = 40 & 60 MeV have been studied theoretically and experimentally in order to establish the underlying mechanism of multifragmentation at intermediate energy heavy-Ion collisions. Nuclear disks formed in central heavy-ion collisions, as simulated by means of Boltzmann-like kinetic equations, break up into several fragments due to a new kind of Rayleigh-like surface instability. A sheet of liquid, stable in the limit of non-interacting surfaces, is shown to become unstable due to surface-surface interactions. The onset of this instability is determined analytically. A thin bubble behaves like a sheet and is susceptible to the surface instability through the crispation mode. The Coulomb effects associated with the depletion of charges in the central cavity of nuclear bubbles are investigated. The onset of Coulomb instability is demonstrated for perturbations of the radial mode. Experimental intermediate-mass-fragment multiplicity distributions for the {sup 129}Xe-induced reactions are shown to be binomial at each transverse energy. From these distributions, independent of the specific target, an elementary binary decay probability p can be extracted that has a thermal dependence. Thus it is inferred that multifragmentation is reducible to a combination of nearly independent emission processes. If sequential decay is assumed, the increase of p with transverse energy implies a contraction of the emission time scale. The sensitivity of p to the lower Z threshold in the definition of intermediate-mass-fragments points to a physical Poisson simulations of the particle multiplicities show that the weak auto-correlation between the fragment multiplicity and the transverse energy does not distort a Poisson distribution into a binomial distribution. The effect of device efficiency on the experimental results has also been studied.

  7. Multi-Module Modeling of Heavy Ion Reactions and the 3rd Flow Component

    NASA Astrophysics Data System (ADS)

    Csernai, L. P.; Anderlik, A.; Anderlik, Cs.; Magas, V. K.; Molná, E.; Nyiri, A.; Röhrich, D.; Tamosiunas, K.

    2004-12-01

    Fluid dynamical calculations with QGP showed a softening of the directed flow while with hadronic matter this effect is absent. On the other hand, we indicated that a third flow component shows up in the reaction plane as an enhanced emission, which is orthogonal to the directed flow. This is not shadowed by the deflected projectile and target, and shows up at measurable rapidities, ycm = 1 - 2. To study the formation of this effect initial stages of relativistic heavy ion collisions are studied. An effective string rope model is presented for heavy ion collisions at RHIC energies. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field. The typical field strength (string tension) for RHIC energies is about 5-12 GeV/fm, what allows us to talk about "string ropes". The results show that QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. The produced initial state can be used as an initial condition for further hydrodynamical calculations. Such initial conditions lead to the creation of third flow component. Recent v1 measurements are promising that this effect can be used as a diagnostic tool of the QGP. Collective flow is sensitive to the early stages of system evolution. To study the sensitivity of the flow signal, we have calculated flow harmonics from a Blast Wave model, a tilted, ellipsoidally expanding source. We studied recent experimental techniques used for calculation of the vn Fourier coefficients and pointed out a few possible problems connected to these techniques, which may impair the sensitivity of flow analysis.

  8. Pre-Equilibrium Effects in the Secondary Particle Spectra in the Reactions with Heavy Ions

    NASA Astrophysics Data System (ADS)

    Fotina, O. V.; Eremenko, D. O.; Parfenova, Yu. L.; Platonov, S. Yu.; Yuminov, O. A.; Kravchuk, V. L.; Gramegna, F.; Barlini, S.; Casini, G.; Bruno, M.; D'Agostino, M.; Wieland, O.; Bracco, A.; Camera, F.

    Theoretical description of the experimentally obtained spectra for protons and α-particles and model calculations for the neutron spectra in the reactions with heavy ions has been presented. The hybrid model of non-equilibrium processes was used. Equilibrium evaporation process was analyzed in the framework of the statistical theory of nuclear reactions with Monte-Carlo simulation including certain dynamical and kinematical characteristics. This approach was included in PACE code, which permits to simulate Monte-Carlo de-excitation nuclear process. The Fermi-gas model and level-density phenomenological model for the variation of the nuclear level density parameters was used. In this approach data on 16O+116Sn reaction with Ebeam = 130, 250 MeV were analyzed. Double-differential light charged particle spectra for this reaction were measured using the GARFIELD apparatus in coincidence with evaporation residues. The experimental data were collected in four angular ranges from 29 to 41, 41 to 53, 53 to 67 and 67 to 82 degrees in the laboratory system. The results of the calculations are shown and discussed for these four angular ranges. The contributions from the evaporative and pre-equilibrium processes were analyzed in connection with different nucleus equilibration mechanisms.

  9. Backtracing of the Impact Parameter through Pattern Recognition Analysis on Heavy Ion Reaction Data

    SciTech Connect

    De Sanctis, Jacopo; Masotti, Matteo; Bonasera, A.

    2007-04-23

    One of the problems in the analysis of nucleus-nucleus collisions is to get information on the value of the impact parameter b through the knowledge of some features of each event. The experimental values of Z, transverse energy and multiplicity of fragments are good candidates to get hints on the values of b. Motivated by this consideration, this work consists in the application of pattern recognition techniques aimed at associating values of b to groups of events. To this end, a support vector machine (SVM) classifier is adopted to analyze multifragmentation reactions. This analysis consists of mainly two different steps. In the first one, known as the training phase, SVM learns how to discriminate between peripheral, semi-peripheral and central reactions. These examples are taken from a large number of events generated with classical molecular dynamics (CMD) and heavy ion phase-space exploration (HIPSE) models for each value of b. In the second one, known as the test phase, what has been learned is tested on new events generated by the same models. Our tests demonstrate that, by following this approach, central, semi-peripheral and peripheral reactions are correctly classified for about 85% of the cases.

  10. Reaction dynamics and nuclear structure of moderately neutron-rich Ne isotopes by heavy-ion reactions

    NASA Astrophysics Data System (ADS)

    Bottoni, S.; Benzoni, G.; Leoni, S.; Montanari, D.; Bracco, A.; Azaiez, F.; Franchoo, S.; Stefan, I.; Blasi, N.; Camera, F.; Crespi, F. C. L.; Corsi, A.; Million, B.; Nicolini, R.; Vigezzi, E.; Wieland, O.; Zocca, F.; Corradi, L.; De Angelis, G.; Fioretto, E.; Guiot, B.; Marginean, N.; Napoli, D. R.; Orlandi, R.; Sahin, E.; Stefanini, A. M.; Valiente-Dobon, J. J.; Aydin, S.; Bazzacco, D.; Farnea, E.; Lenzi, S.; Lunardi, S.; Mason, P.; Mengoni, D.; Montagnoli, G.; Recchia, F.; Ur, C.; Scarlassara, F.; Gadea, A.; Maj, A.; Wrzesinski, J.; Zuber, K.; Dombradi, Zs.; Szilner, S.; Saltarelli, A.; Pollarolo, G.

    2012-06-01

    The heavy-ion reaction 22Ne+208Pb at 128 MeV beam energy has been studied using the PRISMA-CLARA experimental setup at Legnaro National Laboratories. Elastic, inelastic, and one-nucleon transfer differential cross sections are measured and global agreement is obtained with semiclassical and distorted-wave Born approximation (DWBA) calculations. In particular, the angular distribution of the 2+ state of 22Ne is analyzed by DWBA and a similar calculation is performed for the unstable 24Ne nucleus, using existing data from the reaction 24Ne+208Pb at 182 MeV (measured at SPIRAL with the VAMOS-EXOGAM setup). In both cases the DWBA model gives a good reproduction of the experiment, pointing to a strong reduction of the β2C charge deformation parameter in 24Ne. This follows the trend predicted for the evolution of the quadrupole deformation along the Ne isotopic chain.

  11. Heavy ion reaction measurements with the EOS TPC (looking for central collisions with missing energy)

    SciTech Connect

    Wieman, H.H.; EOS Collaboration

    1994-05-01

    The EOS TPC was constructed for complete event measurement of heavy ion collisions at the Bevalac. We report here on the TPC design and some preliminary measurements of conserved event quantities such as total invariant mass, total momentum, total A and Z.

  12. Possibilities of research for on-line mass separator with heavy ion reactions

    NASA Astrophysics Data System (ADS)

    Siváček, I.; Kliman, J.; Rodin, A. M.; Krupa, L'; Belozerov, A. V.; Podshibyakin, A. V.; Salamatin, V. S.; Stepantsov, S. V.; Vedeneev, V. Yu

    2014-09-01

    Mass Analyser of Superheavy Atoms is ISOL - type setup created for direct mass measurement heavy ions. Hot catcher and ECR ion source combination allows effective formation of secondary beams of volatile elements. Powerful magnetic analysing system offers possibility to achieve mass resolution M/ΔM > 1000 in the focal plane silicon strip detector. The efficiency, time characteristics and detection system properties are described. Two applications of setup in different fields of research are presented together with methodology of experiments and data analysis.

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

    SciTech Connect

    Schroeder, W.U.

    1993-08-01

    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.

  14. NUMEN Project @ LNS : Heavy ions double charge exchange reactions towards the 0νββ nuclear matrix element determination

    SciTech Connect

    Agodi, C. Calabretta, L.; Calanna, A.; Carbone, D.; Cavallaro, M.; Colonna, M.; Cuttone, G.; Finocchiaro, P.; Pandola, L.; Rifuggiato, D.; Tudisco, S.; Cappuzzello, F.; Greco, V.; Bonanno, D. L.; Bongiovanni, D. G.; Longhitano, F.; Branchina, V.; Foti, A.; Lo Presti, D.; Lanzalone, G.; and others

    2015-10-28

    In the NUMEN Project it is proposed an innovative technique to access the nuclear matrix elements entering in the expression of the life-time of the neutrinoless double beta decay, using relevant cross sections of double charge exchange reactions. A key aspect is the use of MAGNEX large acceptance magnetic spectrometer, for the detection of the ejectiles, and of the INFN Laboratori Nazionali del Sud (LNS) K800 Superconducting Cyclotron (CS), for the acceleration of the required high resolution and low emittance heavy-ion beams.

  15. Effective moment of inertia for several fission reaction systems induced by nucleons, light particles, and heavy ions

    NASA Astrophysics Data System (ADS)

    Soheyli, S.

    2011-10-01

    The effective moment of inertia of the compound nucleus is calculated for several fission reaction systems induced by nucleons, light particles, and heavy ions. The determination of this quantity for these systems is based upon the comparison between the experimental data of the fission fragment angular distributions as well as the prediction of the standard saddle-point statistical model. For the systems, the two cases, namely with and without neutron emission corrections, were considered. Afterward, our theoretical results are compared with the data obtained from the rotational liquid drop model as well as the Sierk model and satisfactory agreements were found. We also calculated the quadrupole deformation and mass asymmetry parameters of the fissioning nuclei at the saddle point by two methods, the first method is based on an ellipsoid shape assumption for the fissioning nucleus, and the other is based on dinuclear system model, since in heavy ion induced fission reactions, the compound nuclei which undergo fission can be considered as states of two touching clusters (dinuclear system). Afterward, the results of these two methods were compared and satisfactory agreements were found between them.

  16. Transition from subbarrier to deep-subbarrier regimes in heavy-ion fusion reactions

    NASA Astrophysics Data System (ADS)

    Thein, Ei Shwe Zin; Lwin, N. W.; Hagino, K.

    2012-05-01

    We analyze recent experimental data of heavy-ion fusion cross sections available up to deep-subbarrier energies in order to discuss the threshold incident energy for a deep-subbarrier fusion hindrance phenomenon. To this end, we employ a one-dimensional potential model with a Woods-Saxon internuclear potential. Fitting the experimental data in two different energy regions with different Woods-Saxon potentials, we define the threshold energy as an intersection of the two fusion excitation functions. We show that the threshold energies so extracted are in good agreement with the empirical systematics as well as with the values of the Krappe-Nix-Sierk (KNS) potential at the touching point. We also discuss the asymptotic energy shift of fusion cross sections with respect to the potential model calculations, and show that it decreases with decreasing energies in the deep-subbarrier region, although it takes a constant value at subbarrier energies.

  17. Nucleon-nucleon correlations in heavy ion transfer reactions: Recent investigations at energies far below the Coulomb barrier

    SciTech Connect

    Corradi, Lorenzo

    2015-10-15

    Excitation functions of one- and two-neutron transfer channels have been measured for the {sup 96}Zr+{sup 40}Ca and {sup 116}Sn+{sup 60}Ni systems at bombarding energies ranging from the Coulomb barrier to ∼25% below. Target-like recoils have been identified in A, Z and velocity with the large solid angle magnetic spectrometer PRISMA. The experimental transfer probabilities have been compared, in absolute values and in slope, with semiclassical microscopic calculations which incorporate nucleon-nucleon pairing correlations. For the first time in a heavy ion collision, one was able to provide a consistent description of one and two neutron transfer reactions by incorporating, in the reaction mechanism, all known structure information of entrance and exit channels nuclei. In particular, there is no need to introduce any enhancement factor for the description of two neutron transfer, of course very important are the correlations induced by the pairing interaction.

  18. Studies of complex fragment emission in heavy ion reactions. Progress report, January 1, 1993--September 15, 1993

    SciTech Connect

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

    1993-09-12

    The study of intermediate-energy heavy-ion nuclear reactions is reported. This work has two foci: the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities and the study of the relevant reaction mechanisms. Nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. 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. The program has the following objectives: to study energy, mass, and angular momentum deposition by studying incomplete fusion reactions; to gain confidence in the understanding of 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 (where intermediate mass fragment emission is not improbable) with excitation function studies; and to learn about the dynamics of the decays using particle-particle correlations. The last effort focuses on simple systems, where definitive statements are possible. These avenues of research share a common theme, large complex fragment production. It is this feature, more than any other, which distinguishes the intermediate energy domain.

  19. Cross section systematics for the lightest Bi and Po nuclei produced in complete fusion reactions with heavy ions

    SciTech Connect

    Andreyev, A.N.; Ackermann, D.; Muenzenberg, G.; Antalic, S.; Saro, S.; Streicher, B.; Darby, I.G.; Page, R.D.; Wiseman, D.R.; Franchoo, S.; Hessberger, F.P.; Kuusiniemi, P.; Lommel, B.; Kindler, B.; Mann, R.; Sulignano, B.; Hofmann, S.; Huyse, M.; Vel, K. van de; Duppen, P. van

    2005-07-01

    The production of the very neutron-deficient nuclides {sup 184-192}Bi and {sup 186-192}Po in the vicinity of the neutron midshell at N = 104 has been studied by using heavy-ion-induced complete fusion reactions in a series of experiments at the velocity filter SHIP. The cross sections for the xn and pxn evaporation channels of the {sup 46}Ti+{sup 144}Sm{yields}{sup 190}Po*,{sup 98}Mo+{sup 92}Mo{yields}{sup 190}Po*,{sup 50,52}Cr+{sup 142}Nd{yields}{sup 192,194}Po*, and {sup 94,95}Mo+{sup 93}Nb{yields}{sup 187,188}Bi* reactions were measured. The results obtained, together with the previously known cross section data for the heavier Bi and Po nuclides, are compared with the results of statistical model calculations carried out with the HIVAP code. It is shown that a satisfactory description of the experimental data requires a significant (up to 35%) reduction of the theoretical fission barriers. The optimal reactions for production of the lightest Bi and Po isotopes are discussed.

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

    SciTech Connect

    Patin, Joshua B.

    2002-05-24

    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.

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

    SciTech Connect

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

    1992-09-01

    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.

  2. PREFACE: International Symposium on Entrance Channel Effect on the Reaction Mechanism in Heavy Ion Collisions

    NASA Astrophysics Data System (ADS)

    Giardina, Giorgio; Nasirov, Avazbek K.; Mandaglio, Giuseppe

    2014-05-01

    The aim of the Symposium has been to widen and detail the discussion of problems arising in front of experimental and theoretical groups, and to find overlap between different approaches and methods which are devoted to the studying dynamics of nuclear reactions. Therefore, the reaction product yields are determined by various processes in competition. The main topics of the Symposium have been devoted to the following well sounded problems of nuclear reactions: The synthesis of superheavy elements and the study of exotic nuclei far from the valley of the beta stability. The production mechanism of the observed new elements and isotopes. The study of transfer reactions as a way to understand mechanism of evolution of from the deep-inelastic collisions to fusion regime. The study of non-equilibrium stage of the reaction mechanism and distribution of the excitation energy between binary reaction products including spontaneous fission products are still important to have a correct presentation about the whole reaction mechanism. The similarities and difference between fusion-fission and quasifission products. Unambiguity in estimation of the realistic fusion cross sections by the experimental and theoretical methods. Angular anisotropy of the complete and incomplete fusion reaction products. The effect of the nuclear shell structure in formation of the mass symmetric and asymmetric fission products. The investigation of the role of angular momentum, mass asymmetry and orientation angles of the symmetry axes of colliding nuclei in the entrance channel in formation of the evaporation residues, mass and angular distribution of the fusion-fission and quasifission products. Multi-fragmentation and symmetry energy. The new experimental and theoretical investigations on these and related topics allow researchers to improve knowledge about nucleus-nucleus interaction dynamics and to make conclusions about perspectives in the study of the landscape of islands superheavy

  3. Experimental determination of particle range and dose distribution in thick targets through fragmentation reactions of stable heavy ions.

    PubMed

    Inaniwa, Taku; Kohno, Toshiyuki; Tomitani, Takehiro; Urakabe, Eriko; Sato, Shinji; Kanazawa, Mitsutaka; Kanai, Tatsuaki

    2006-09-01

    In radiation therapy with highly energetic heavy ions, the conformal irradiation of a tumour can be achieved by using their advantageous features such as the good dose localization and the high relative biological effectiveness around their mean range. For effective utilization of such properties, it is necessary to evaluate the range of incident ions and the deposited dose distribution in a patient's body. Several methods have been proposed to derive such physical quantities; one of them uses positron emitters generated through projectile fragmentation reactions of incident ions with target nuclei. We have proposed the application of the maximum likelihood estimation (MLE) method to a detected annihilation gamma-ray distribution for determination of the range of incident ions in a target and we have demonstrated the effectiveness of the method with computer simulations. In this paper, a water, a polyethylene and a polymethyl methacrylate target were each irradiated with stable (12)C, (14)N, (16)O and (20)Ne beams. Except for a few combinations of incident beams and targets, the MLE method could determine the range of incident ions R(MLE) with a difference between R(MLE) and the experimental range of less than 2.0 mm under the circumstance that the measurement of annihilation gamma rays was started just after the irradiation of 61.4 s and lasted for 500 s. In the process of evaluating the range of incident ions with the MLE method, we must calculate many physical quantities such as the fluence and the energy of both primary ions and fragments as a function of depth in a target. Consequently, by using them we can obtain the dose distribution. Thus, when the mean range of incident ions is determined with the MLE method, the annihilation gamma-ray distribution and the deposited dose distribution can be derived simultaneously. The derived dose distributions in water for the mono-energetic heavy-ion beams of four species were compared with those measured with an

  4. Study of near-stability nuclei populated as fission fragments in heavy-ion fusion reactions

    SciTech Connect

    Fotiadis, Nikolaos; Nelson, Ronald O; Devlin, Matthew; Cizewski, Jolie A; Krucken, Reiner; Clark, R M; Fallon, Paul; Lee, I Yang; Macchiavelli, Agusto O; Becker, John A; Younes, Walid

    2010-01-01

    Examples are presented to illustrate the power of prompt {gamma}-ray spectroscopy of fission fragments from compound nuclei with A {approx} 200 formed in fusion-evaporation reactions in experiments using the Gammasphere Ge-detector array. Complementary methods, such as Coulomb excitation and deep-inelastic processes, are also discussed. In other cases (n, xn{gamma}) reactions on stable isotopes have been used to establish neutron excitation functions for {gamma}-rays using a pulsed 'white'-neutron source, coupled to a high-energy-resolution germanium-detector array. The excitation functions can unambiguously assign {gamma}-rays to a specific reaction product. Results from all these methods bridge the gaps in the systematics of high-spin states between the neutron-deficient and neutron-rich nuclei. Results near shell closures should motivate new shell model calculations.

  5. Entrance-channel mass-asymmetry dependence of compound nucleus formation time in light heavy-ion reactions

    SciTech Connect

    Szanto de Toledo, A.; Carlson, B.V.; Beck, C.

    1996-12-01

    The entrance-channel mass-asymmetry dependence of the compound nucleus formation time in light heavy-ion reactions has been investigated within the framework of semiclassical dissipative collision models. The model calculations have been applied successfully to the formation of the {sup 38}Ar compound nucleus as populated via the {sup 9}Be+{sup 29}Si, {sup 11}B+{sup 27}Al, {sup 12}C+{sup 26}Mg, and {sup 19}F+{sup 19}F entrance channels. The shape evolution of several other light composite systems appears to be consistent with the so-called {open_quote}{open_quote}Fusion Inhibition Factor{close_quote}{close_quote} which has been observed experimentally. As found previously in more massive systems for the fusion-evaporation process, the entrance-channel mass-asymmetry degree of freedom appears to determine the competition between the different mechanisms as well as the time scales involved. {copyright} {ital 1996 The American Physical Society.}

  6. Analysis of heavy-ion fusion reactions at extreme sub-barrier energies using the proximity formalism

    NASA Astrophysics Data System (ADS)

    Ghodsi, O. N.; Gharaei, R.

    2013-11-01

    The recent measured values of the fusion excitation functions of the heavy-ion colliding systems 28Si+100Mo, 58Ni+54Fe, and 64Ni+64Ni are investigated using the original version of the proximity formalism. The fusion cross sections are calculated based on the coupled-channels approach, including couplings to the low-lying 2+ and 3- states in both target and projectile nuclei. The comparison between the calculated and the measured values of the fusion excitation functions indicates that the potential Prox.77 needs to be modified considerably at sub-barrier energies. In the present study, the role of the surface energy coefficient γ and also the temperature T of the compound nucleus in nuclear potential and fusion cross section has been explored for our colliding systems. Moreover, the mutual and the multiphonon excitations of the lowest 2+ and 3- states are considered in the coupled-channels calculations. It is demonstrated that the potential Prox.77 with these corrective effects can reproduce the experimental data of the fusion cross section, the S factor and the logarithmic derivative for fusion reactions 28Si+100Mo, 58Ni+54Fe, and 64Ni+64Ni with good accuracy especially at below-barrier energies.

  7. Heavy ion collision dynamics of 10,11B+10,11B reactions

    NASA Astrophysics Data System (ADS)

    Singh, BirBikram; Kaur, Manpreet; Kaur, Varinderjit; Gupta, Raj K.

    2015-01-01

    The dynamical cluster-decay model (DCM) of Gupta and collaborators has been applied successfully to the decay of very-light (A ˜ 30), light (A ˜ 40-80), medium, heavy and super-heavy mass compound nuclei for their decay to light particles (evaporation residues, ER), fusion-fission (ff), and quasi-fission (qf) depending on the reaction conditions. We intend to extend here the application of DCM to study the extreme case of decay of very-light nuclear systems 20,21,22Ne∗ formed in 10,11B+10,11B reactions, for which experimental data is available for their binary symmetric decay (BSD) cross sections, i.e., σBSD. For the systems under study, the calculations are presented for the σBSD in terms of their preformation and barrier penetration probabilities P0 and P. Interesting results are that in the decay of such lighter systems there is a competing reaction mechanism (specifically, the deep inelastic orbiting of non-compound nucleus (nCN) origin) together with ff. We have emipirically estimated the contribution of σnCN. Moreover, the important role of nuclear structure characteristics via P0 as well as angular momentum ℓ in the reaction dynamics are explored in the study.

  8. Fission barriers for Po nuclei produced in complete fusion reactions with heavy ions

    SciTech Connect

    Sagaidak, R. N.; Andreyev, A. N.

    2009-05-15

    Evaporation residues and fission excitation functions obtained in complete fusion reactions leading to Po compound nuclei have been analyzed in the framework of the standard statistical model. Macroscopic fission barriers deduced from the cross-section data analysis are compared with the predictions of various theoretical models and available data. A drop in the Po barriers with the decrease in a neutron number was found, which is stronger than predicted by any theory. The presence of entrance channel effects and collective excitations in the compound nucleus decay is considered as a possible reason for the barrier reduction.

  9. Comparison of fast cascade plus statistical models for heavy ion induced multifragmentation reactions

    NASA Astrophysics Data System (ADS)

    Mustafa, M. G.; Blann, M.; Peilert, G.; Botvina, A.

    1994-05-01

    We consider the reaction 36Ar+197Au at incident 36Ar energies of 35, 50, 80, and 110A MeV, comparing calculations of precompound decay using the Boltzmann master equation (BME) and quantum molecular dynamics (QMD) models. We then estimate quasiequilibrated nuclei and excitations using the BME, and use these values as input into statistical multifragmentation models. For the latter we compare sequential binary decay as an extension of the Weisskopf-Ewing evaporation model, and a simultaneous multifragmentation for an expanded low density gas. The exclusive multiplicities predicted by these models are compared with experimental results.

  10. The time scale of quasifission process in reactions with heavy ions

    NASA Astrophysics Data System (ADS)

    Knyazheva, G. N.; Itkis, I. M.; Kozulin, E. M.

    2014-05-01

    The study of mass-energy distributions of binary fragments obtained in the reactions of 36S, 48Ca, 58Fe and 64Ni ions with the 232Th, 238U, 244Pu and 248Cm at energies below and above the Coulomb barrier is presented. These data have been measured by two time-of-flight CORSET spectrometer. The mass resolution of the spectrometer for these measurements was about 3u. It allows to investigate the features of mass distributions with good accuracy. The properties of mass and TKE of QF fragments in dependence on interaction energy have been investigated and compared with characteristics of the fusion-fission process. To describe the quasifission mass distribution the simple method has been proposed. This method is based on the driving potential of the system and time dependent mass drift. This procedure allows to estimate QF time scale from the measured mass distributions. It has been found that the QF time exponentially decreases when the reaction Coulomb factor Z1Z2 increases.

  11. Heavy ion fusion--Using heavy ions to make electricity

    SciTech Connect

    Celata, C.M.

    2004-03-15

    The idea of using nuclear fusion as a source of commercial electrical power has been pursued worldwide since the 1950s. Two approaches, using magnetic and inertial confinement of the reactants, are under study. This paper describes the difference between the two approaches, and discusses in more detail the heavy-ion-driven inertial fusion concept. A multibeam induction linear accelerator would be used to bring {approx}100 heavy ion beams to a few GeV. The beams would then heat and compress a target of solid D-T. This approach is unique among fusion concepts in its ability to protect the reaction chamber wall from neutrons and debris.

  12. New recoil transfer chamber for thermalization of heavy ions produced in fusion-evaporation reactions

    NASA Astrophysics Data System (ADS)

    Alfonso, M. C.; Tereshatov, E. E.; DeVanzo, M. J.; Sefcik, J. A.; Bennett, M. E.; Mayorov, D. A.; Werke, T. A.; Folden, C. M.

    2015-10-01

    A new Recoil Transfer Chamber (RTC) has been designed, fabricated, and characterized at the Cyclotron Institute at Texas A&M University. The design is based on a gas stopper that was previously in routine use at the National Superconducting Cyclotron Laboratory. This new RTC uses He gas to stop ions, and a combination of a static electric field and gas flow to maximize the extraction efficiency. In offline experiments, a 228Th source was used to produce 216Po which was successfully extracted even though it has a short half-life. In online experiments using the products of the 118Sn(40Ar, 6n)152Er reaction, an efficiency of several tens of percent was measured.

  13. Nuclear structure effects on heavy-ion reactions with microscopic theory

    NASA Astrophysics Data System (ADS)

    Vo-Phuoc, K.; Simenel, C.; Simpson, E. C.

    2016-09-01

    The self-consistent mean-field Hartree-Fock (HF) theory, both static and time-dependent (TDHF) versions, is used to study static and dynamic properties of fusion reactions between even 40-54Ca isotopes and 116Sn. The bare nucleus-nucleus potential, calculated with the frozen HF approach, is affected by the groundstate density of the nuclei. However, once dynamical effects are included, as in TDHF, the static effects on the barrier are essentially washed out. Dynamic properties of the nuclei, including low-lying vibrational modes, are calculated with TDHF and selectively used in coupled-channels calculations to identify which modes have the most effect on the TDHF fusion threshold. Vibrations cannot fully explain the difference between the static HF and TDHF fusion barriers trend so other dynamical effects such as transfer are considered.

  14. Investigating multichannel quantum tunneling in heavy-ion fusion reactions with Bayesian spectral deconvolution

    NASA Astrophysics Data System (ADS)

    Hagino, K.

    2016-06-01

    Excitations of colliding nuclei during a nuclear reaction considerably affect fusion cross sections at energies around the Coulomb barrier. It has been demonstrated that such channel coupling effects can be represented in terms of a distribution of multiple fusion barriers. I here apply a Bayesian approach to analyze the so-called fusion barrier distributions. This method determines simultaneously the barrier parameters and the number of barriers. I particularly investigate the 16O+144Sm and 16O+154Sm systems in order to demonstrate the effectiveness of the method. The present analysis indicates that the fusion barrier distribution for the former system is most consistent with three fusion barriers, even though the experimental data show only two distinct peaks.

  15. Theoretical Study of Projectile Fragmentations in Relativistic Heavy-Ion Reactions

    NASA Astrophysics Data System (ADS)

    Ogul, R.; Imal, H.; Ergun, A.; Buyukcizmeci, N.; Botvina, A. S.; Trautmann, W.

    2015-05-01

    We have investigated and interpreted the production cross sections and isotopic distributions of projectile-like residues in the reactions 124Sn + 124Sn and 112Sn + 112Sn at an incident beam energy of 1 GeV/nucleon measured with the FRS fragment separator at the GSI laboratory. For the interpretation of the data, calculations within the statistical multifragmentation model (SMM) for an ensemble of excited sources were performed with ensemble parameters. The possible modification of symmetry energy parameter, in the multifragmentation region at the low density and hot freeze-out environment, is studied. It is reconfirmed that a significant reduction of the symmetry energy term is found necessary to reproduce experimental results at these conditions. We have also found a decreasing trend of the symmetry energy for large neutron-rich fragments of low excitation energy which is interpreted as a nuclear-structure effect.

  16. Procedure for measuring photon and vector meson circular polarization variation with respect to the reaction plane in relativistic heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Tang, A. H.; Wang, G.

    2016-08-01

    The electromagnetic (EM) field pattern created by spectators in relativistic heavy-ion collisions plants a seed of positive (negative) magnetic helicity in the hemisphere above (below) the reaction plane. Owing to the chiral anomaly, the magnetic helicity interacts with the fermionic helicity of the collision system and causes photons emitted in upper and lower hemispheres to have different preferences in the circular polarization. Similar helicity separation for massive particles, owing to the global vorticity, is also possible. In this paper, we lay out a procedure to measure the variation of the circular polarization with respect to the reaction plane in relativistic heavy-ion collisions for massless photons, as well as similar polarization patterns for vector mesons decaying into two daughters. We propose to study the yield differentially and compare the yield between upper and lower hemispheres to identify and quantify such effects.

  17. Contribution of neutron reactions in hybrid targets of inertial heavy ion fusion (HIF)

    NASA Astrophysics Data System (ADS)

    Imshennik, V. S.; Zhukov, V. T.

    2006-08-01

    Recently some simple estimations (Koskarev, Sharkov) were made for capability of achievement of critical conditions in an uranium shell of HIF energetic target, and afterwards it was proved use of an uranium shell (pusher) for substantial expansion of energy-release in a such hybrid target. The mentioned justification is included accounting of neutron-induced fission in the pusher. This accounting is formulated as generalization for cylindrical geometry of the well-known Axiezer-Pomeranchuk solution. A corresponding analytical solution of one-speed Payerls equation allows sufficiently accurately to compute the critical parameters of the uranium pusher in hydrodynamic model of compression and fusion of HIF target ( taking into account of development of chain nuclear fission reaction under critical condition achievement). Nevertheless the implemented computations show that the most essential effect is forced nuclear fission of uranium under the influence of thermonuclear neutrons generated by fusion of deuterium- tritium fuel in the central region of the target. In these computations we use a simple analytical description of forced nuclear fission of uranium by thermonuclear neutrons. The critical conditions are not achieved in the considered ( not optimized) hybrid targets but they are close to accomplishment in the investigated shock-free compression regime. This regime of compression is the most adequate one for hybrid HIF targets. The obtained results allow us to make conclusion of advisability of further development of energetic hybrid HIF targets particularly their optimization and utilization of natural uranium as pusher materials.

  18. Heavy-Ion Reactions in Time-dependent Hartree-Fock

    SciTech Connect

    Maruhn, J.A.

    2005-03-31

    Nuclear collisions at low energies present a unique opportunity for the study of degenerate Fermi systems far from equilibrium. Their behavior shows a rich variety: from complete fusion through highly nonelastic collisions to grazing situations with a complicated interplay of collective and single-particle degrees of freedom. The time-dependent Hartree-Fock approximation assumes a dominance of Pauli exclusion, ignoring the two-body collisions and instead using the mean field as the dominant dynamic quantity. For a class of zero-range effective interactions (the so-called Skyrme forces) it is possible to numerically solve the equations of motion to obtain a description of reactions that is parameter-free in the sense that the forces are fitted exclusively to nuclear ground-state properties. In this talk I give an overview of the theoretical issues, ignoring much of the technical detail of nuclear theory involved in such studies, and instead concentrating on the interesting consequences of the nonlinear coupling through the mean field: the spurious interaction between the different exit channels, the 'one-body dissipation' mechanism and the essential semiclassical nature of the approach.

  19. Moon originating heavy ions associated with CIR

    NASA Astrophysics Data System (ADS)

    Saito, Yoshifumi; Yokota, Shoichiro; Nishino, Masaki; Tsunakawa, Hideo

    2014-05-01

    Existance of a tenuous alkali atmosphere around the Moon was discovered by ground-based optical observations in 1980s. Since then the generation mechanism of the alkali atmosphere has been actively investigated. Currently, photon-stimulated desorption is regarded as the major generation process of the lunar alkai atmosphere such as sodium and potassium. MAP-PACE-IMA on Kaguya found four typical ion populations on the dayside of the Moon. These includes (1) solar wind protons backscattered at the lunar surface, (2) solar wind protons reflected by magnetic anomalies on the lunar surface, (3) reflected/backscattered protons picked-up by the solar wind, and (4) ions originating from the lunar surface/lunar exosphere. One of these populations: (4) ions originating from the lunar surface/lunar exosphere usually consisted of heavy ions such as carbon, oxygen, sodium, and potassium. Some of these ions were generated on the lunar surface by photon-stimulated desorption especially for alkali ions such as sodium and potassium and some others were generated by solar wind sputtering. Photo-ionized neutral particles were also included in these ions. These heavy ions were accelerated by the solar wind convection electric field and detected by the ion energy mass spectrometer MAP-PACE-IMA on Kaguya. Since the gyro-radius of these heavy ions was much larger than the Moon, the energy of these ions detected at 100km altitude was in most cases lower than the incident solar wind ion energy. Two special examples were found where the energy of the heavy ions was higher than the incident solar wind ion energy. These high-energy heavy ions were observed on the dayside of the Moon when CIR (Corotating Interaction Region) passed the Moon. The high energy heavy ions were observed for several hours with the highest heavy ion flux observed when the solar wind pressure increased due to the passage of the CIR. The mass spectrum of the heavy ions observed associated with CIR showed H+, He++, He

  20. Violence of heavy-ion reactions from neutron multiplicity: 11 to 20A-italic MeV /sup 20/Ne+ /sup 238/U

    SciTech Connect

    Jahnke, U.; Ingold, G.; Hilscher, D.; Lehmann, M.; Schwinn, E.; Zank, P.

    1986-07-14

    The suitability of the neutron multiplicity as a gauge for the violence of medium-energy heavy-ion reactions is investigated for the first time. For this purpose the number of neutrons emitted from fission reactions induced by 220-, 290-, and 400-MeV /sup 20/Ne on /sup 238/U is registered event-by-event with a large 4..pi.. scintillator tank. It is shown that the neutron multiplicity is indeed closely related to the two quantities characterizing the violence: the induced total intrinsic excitation and the linear momentum transfer.

  1. The Ring Counter (RCo): A high resolution IC Si CsI(Tl) device for heavy ion reaction studies at 10 30 MeV/A

    NASA Astrophysics Data System (ADS)

    Moroni, A.; Bruno, M.; Bardelli, L.; Barlini, S.; Brambilla, S.; Casini, G.; Cavaletti, R.; Chiari, M.; Cortesi, A.; D'Agostino, M.; De Sanctis, J.; Geraci, E.; Giordano, G.; Giussani, A.; Gramegna, F.; Guiot, B.; Kravchuk, V.; Lanchais, A.; Margagliotti, G. V.; Nannini, A.; Ordine, A.; Piantelli, S.; Vannini, G.; Vannucci, L.

    2006-01-01

    An annular detector (Ring Counter, RCo) is presented, which has been designed and built to detect and identify in mass and charge light charged particles and fragments with very low energy thresholds and high energy resolution. It complements the GARFIELD apparatus, operating at INFN Laboratori Nazionali di Legnaro, to detect the forward emitted products of nuclear heavy ion reactions. It consists of eight sectors of a three-stage telescope, each one formed by an ionization chamber followed by eight strips of a silicon detector and by two CsI(Tl) scintillators. Construction features and performances are described and discussed in details.

  2. Heavy-ion dosimetry

    SciTech Connect

    Schimmerling, W.

    1980-03-01

    This lecture deals with some of the more important physical characteristics of relativistic heavy ions and their measurement, with beam delivery and beam monitoring, and with conventional radiation dosimetry as used in the operation of the BEVALAC biomedical facility for high energy heavy ions (Lyman and Howard, 1977; BEVALAC, 1977). Even so, many fundamental aspects of the interaction of relativistic heavy ions with matter, including important atomic physics and radiation chemical considerations, are not discussed beyond the reminder that such additional understanding is required before an adequte perspective of the problem can be attained.

  3. A telescope with microstrip gas chambers for the detection of charged products in heavy-ion reactions

    NASA Astrophysics Data System (ADS)

    Gramegna, F.; Abbondanno, U.; Andreano, A.; Bassini, R.; Bonutti, F.; Bruno, M.; Casini, G.; D'Agostino, M.; Manzin, G.; Margagliotti, G. V.; Mastinu, P. F.; Milazzo, P. M.; Moroni, A.; Squarcini, M.; Tonetto, F.; Vannini, G.; Vannucci, L.

    1997-02-01

    Prototypes of a ΔE-E telescope, designed to detect and identify with low-energy threshold both light charged particles and heavy fragments, are described. They are based on a gas drift chamber which conveys primary ionization electrons on gas microstrip devices where multiplication occurs and the energy loss signals are generated. Silicon detectors or CsI(T1) crystals operate as residual energy detectors. The prototypes were tested both with a source and heavy ion beams. Performances, mainly related to energy resolution, charge identification and angle resolution, are reported.

  4. Two-proton correlation measurements in 800 and 400 MeV/nucleon heavy-ion reactions

    SciTech Connect

    Tanihata, I; Lemaire, M -C; Nagamiya, S; Schnetzer, S

    1980-03-01

    Energy and angular correlations of two protons emitted in collisions of C + C, C + Pb, Ne + NaF, Ar + KCl, at Elabbeam = 800MeV/A, and Ne + NaF at Elabbeam = 400MeV/A have been measured. A strong correlation due to p-p quasi-elastic scattering is observed except for C + Pb where nuclear shadowing is observed. A simple model is proposed to estimate the magnitude of the knock-out process in these heavy-ion collisions.

  5. Beam dynamics in heavy ion induction LINACS

    SciTech Connect

    Smith, L.

    1981-10-01

    Interest in the use of an induction linac to accelerate heavy ions for the purpose of providing the energy required to initiate an inertially confined fusion reaction has stimulated a theoretical effort to investigate various beam dynamical effects associated with high intensity heavy ion beams. This paper presents a summary of the work that has been done so far; transverse, longitudinal and coupled longitudinal transverse effects are discussed.

  6. Heavy ion collisions

    SciTech Connect

    Jacak, B.V.

    1994-11-01

    Heavy ion collisions at very high energies provide an opportunity to recreate in the laboratory the conditions which existed very early in the universe, just after the big bang. We prepare matter at very high energy density and search for evidence that the quarks and gluons are deconfined. I describe the kinds of observables that are experimentally accessible to characterize the system and to search for evidence of new physics. A wealth of information is now available from CERN and BNL heavy ion experiments. I discuss recent results on two particle correlations, strangeness production, and dilepton and direct photon distributions.

  7. Centrality and energy dependence of charged-particle multiplicities in heavy ion collisions in the context of elementary reactions

    SciTech Connect

    Back, B. B.; Wuosmaa, A. H.; Baker, M. D.; Barton, D. S.; Carroll, A.; Gushue, S.; Heintzelman, G. A.; Holzman, B.; Pak, R.; Remsberg, L. P.; Steinberg, P.; Sukhanov, A.; Betts, R. R.; Garcia, E.; Halliwell, C.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Kucewicz, W.; McLeod, D.

    2006-08-15

    The PHOBOS experiment at the BNL Relativistic Heavy Ion Collider has measured the total multiplicity of primary charged particles as a function of collision centrality in Au+Au collisions at {radical}(s{sub NN})= 19.6, 130, and 200 GeV. An approximate independence of / on the number of participating nucleons is observed, reminiscent of 'wounded nucleon' scaling (N{sub ch}{proportional_to}N{sub part}) observed in proton-nucleus collisions. Unlike p+A, the constant of proportionality does not seem to be set by the pp/pp data at the same energy. Rather, there seems to be a surprising correspondence with the total multiplicity measured in e{sup +}e{sup -} annihilations, as well as the rapidity shape measured over a large range. The energy dependence of the integrated multiplicity per participant pair shows that e{sup +}e{sup -} and A+A data agree over a large range of center-of-mass energies ({radical}(s)>20 GeV), and pp/pp data can be brought to agree approximately with the e{sup +}e{sup -} data by correcting for the typical energy taken away by leading particles. This is suggestive of a mechanism for soft particle production that depends mainly on the amount of available energy. It is conjectured that the dominant distinction between A+A and p+p collisions is the multiple collisions per participant, which appears to be sufficient to substantially reduce the energy taken away by leading particles.

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

    SciTech Connect

    Itkis, I. M.; Itkis, M. G.; Knyazheva, G. N.; Kozulin, E. M.

    2012-10-20

    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.

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

    SciTech Connect

    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

    2011-06-15

    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.

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

    NASA Astrophysics Data System (ADS)

    Itkis, I. M.; Itkis, M. G.; Knyazheva, G. N.; Kozulin, E. M.

    2012-10-01

    Mass and energy distributions of binary reaction products obtained in the reactions 22Ne+249Cf,26Mg+248Cm,36S+238U and 58Fe+208Pb leading to Hs isotopes have been measured. At energies below the Coulomb barrier the bimodal fission of Hs*, formed in the reaction 26Mg+248Cm, is observed. In the reaction 36S+238U 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 58Fe+208Pb 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.

  11. Production cross sections for heavy-ion fragmentation reactions on a liquid deuterium target at intermediate energies

    SciTech Connect

    Roeder, B. T.; Kemper, K. W.; Aoi, N.; Motobayashi, T.; Takeuchi, S.; Bazin, D.; Mueller, W. F.; Yoneda, K.; Bowen, M.; Campbell, C. M.; Cook, J. M.; Dinca, D.-C.; Gade, A.; Glasmacher, T.; Terry, J. R.; Zwahlen, H.; Iwasaki, H.; Sakurai, H.; Suzuki, H.; Kanno, S.

    2006-09-15

    The inclusive cross sections for 38 different reaction products produced in the interaction of {sup 48}Ca, {sup 40}S, and {sup 42}S beams around 100 MeV/nucleon with a liquid deuterium target are reported. The cross sections for the {sup 48}Ca +{sup 2}H products are compared to those with {sup 48}Ca incident on the commonly used fragmentation targets {sup 9}Be and {sup 181}Ta and also to global calculations for fragmentation reaction cross sections based on the EPAX parameterization. The sizes of the measured reaction cross sections for the deuterium target were comparable to those of the cross sections measured on the heavier targets, indicating that nucleon removal from a deuterium target can be carried out for single- and multiple-nucleon knockout reaction studies. It was also found that the charge exchange cross sections were large enough that it should be possible to obtain nuclear structure information from these reactions.

  12. Fusion hindrance and quasi-fission in heavy-ion induced reactions: disentangling the effect of different parameters

    SciTech Connect

    Fioretto, E.; Stefanini, A. M.; Behera, B. R.; Corradi, L.; Gadea, A.; Latina, A.; Trotta, M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Chizhov, A. Yu.; Itkis, I. M.; Itkis, M. G.; Kniajeva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Pokrovsky, I. V.; Sagaidak, R. N.; Voskressensky, V. M.; Courtin, S.

    2006-04-26

    Experimental results on the fusion inhibition effect near the Coulomb barrier due to the onset of the quasi-fission mechanism are presented. The investigation was focused on reactions induced by 48Ca projectiles on different heavy targets and comparing them to reactions induced by light ions such as 12C and 16O leading to the same compound nuclei. Cross sections and angular distributions of evaporation residues and fission fragments have been measured.

  13. GARFIELD + RCo digital upgrade: A modern set-up for mass and charge identification of heavy-ion reaction products

    NASA Astrophysics Data System (ADS)

    Bruno, M.; Gramegna, F.; Marchi, T.; Morelli, L.; Pasquali, G.; Casini, G.; Abbondanno, U.; Baiocco, G.; Bardelli, L.; Barlini, S.; Bini, M.; Carboni, S.; Cinausero, M.; D'Agostino, M.; Degerlier, M.; Kravchuk, V. L.; Geraci, E.; Mastinu, P. F.; Ordine, A.; Piantelli, S.; Poggi, G.; Moroni, A.

    2013-10-01

    An upgraded GARFIELD + Ring Counter (RCo) apparatus is presented with improved performances as far as electronics and detectors are concerned. On the one hand fast sampling digital read out has been extended to all detectors, allowing for an important simplification of the signal processing chain together with an enriched extracted information. On the other hand a relevant improvement has been made in the forward part of the set-up (RCo): an increased granularity of the CsI(Tl) crystals and a higher homogeneity in the silicon detector resistivity. The renewed performances of the GARFIELD + RCo array make it suitable for nuclear reaction measurements both with stable and with Radioactive Ion Beams (RIB), like the ones planned for the SPES facility, where the physics of isospin can be studied.

  14. How the projectile neutron number influences the evaporation cross section in complete fusion reactions with heavy ions

    SciTech Connect

    Wang Chengbin; Zhang Jinjuan; Ren, Z. Z.; Shen, C. W.

    2010-11-15

    The influence of the projectile neutron number on the evaporation residue cross sections for the reactions {sup 208}Pb({sup 52,54}Cr,n,2n){sup 258-261}Sg and {sup 208}Pb({sup 48,50}Ti,n,2n){sup 254-257}Rf has been studied within the framework of a fusion-fission statistical model. The results obtained with the kewpie2 code are compared with recent experimental data. The excitation functions represent the experimental results well both in the maximum value and the lactation of the peak. The calculations show that the projectile neutron number greatly influences both the capture cross section and the fusion probability.

  15. Heavy ion beam probing

    SciTech Connect

    Hickok, R L

    1980-07-01

    This report consists of the notes distributed to the participants at the IEEE Mini-Course on Modern Plasma Diagnostics that was held in Madison, Wisconsin in May 1980. It presents an overview of Heavy Ion Beam Probing that briefly describes the principles and discuss the types of measurements that can be made. The problems associated with implementing beam probes are noted, possible variations are described, estimated costs of present day systems, and the scaling requirements for large plasma devices are presented. The final chapter illustrates typical results that have been obtained on a variety of plasma devices. No detailed calculations are included in the report, but a list of references that will provide more detailed information is included.

  16. HEAVY ION LINEAR ACCELERATOR

    DOEpatents

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

    1959-01-01

    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.

  17. Simple parametrization of fragment reduced widths in heavy ion collisions.

    PubMed

    Tripathi, R K; Townsend, L W

    1994-04-01

    A systematic analysis of the observed reduced widths obtained in relativistic heavy ion fragmentation reactions is used to develop a phenomenological parametrization of these data. The parametrization is simple, accurate, and completely general in applicability.

  18. Lithological influence of aggregate in the alkali-carbonate reaction

    SciTech Connect

    Lopez-Buendia, A.M. . E-mail: angel.lopez@aidico.es; Climent, V. . E-mail: vcliment@grupogla.com; Verdu, P.

    2006-08-15

    The reactivity of carbonate rock with the alkali content of cement, commonly called alkali-carbonate reaction (ACR), has been investigated. Alkali-silica reaction (ASR) can also contribute in the alkali-aggregate reaction (AAR) in carbonate rock, mainly due to micro- and crypto-crystalline quartz or clay content in carbonate aggregate. Both ACR and ASR can occur in the same system, as has been also evidenced on this paper. Carbonate aggregate samples were selected using lithological reactivity criteria, taking into account the presence of dedolomitization, partial dolomitization, micro- and crypto-crystalline quartz. Selected rocks include calcitic dolostone with chert (CDX), calcitic dolostone with dedolomitization (CDD), limestone with chert (LX), marly calcitic dolostone with partial dolomitization (CD), high-porosity ferric dolostone with clays (FD). To evaluate the reactivity, aggregates were studied using expansion tests following RILEM AAR-2, AAR-5, a modification using LiOH AAR-5Li was also tested. A complementary study was done using petrographic monitoring with polarised light microscopy on aggregates immersed in NaOH and LiOH solutions after different ages. SEM-EDAX has been used to identify the presence of brucite as a product of dedolomitization. An ACR reaction showed shrinkage of the mortar bars in alkaline solutions explained by induced dedolomitization, while an ASR process typically displayed expansion. Neither shrinkage nor expansion was observed when mortar bars were immersed in solutions of lithium hydroxide. Carbonate aggregate classification with AAR pathology risk has been elaborated based on mechanical behaviours by expansion and shrinkage. It is proposed to be used as a petrographic method for AAR diagnosis to complement the RILEM AAR1 specifically for carbonate aggregate. Aggregate materials can be classified as I (non-reactive), II (potentially reactive), and III (probably reactive), considering induced dedolomitization ACR

  19. Imaging using accelerated heavy ions

    SciTech Connect

    Chu, W.T.

    1982-05-01

    Several methods for imaging using accelerated heavy ion beams are being investigated at Lawrence Berkeley Laboratory. Using the HILAC (Heavy-Ion Linear Accelerator) as an injector, the Bevalac can accelerate fully stripped atomic nuclei from carbon (Z = 6) to krypton (Z = 34), and partly stripped ions up to uranium (Z = 92). Radiographic studies to date have been conducted with helium (from 184-inch cyclotron), carbon, oxygen, and neon beams. Useful ranges in tissue of 40 cm or more are available. To investigate the potential of heavy-ion projection radiography and computed tomography (CT), several methods and instrumentation have been studied.

  20. Nuclear interactions of heavy ions

    SciTech Connect

    Tabak, M.; Bangerter, R.

    1982-02-24

    A possible source of preheat for heavy ion driven inertial fusion targets is the production of fast precursors by nuclear interactions between the incident heavy ions and the outer parts of the target. A model has been developed which roughly describes these interactions for all beam-target combinations for all incident energies. This interaction model has been applied to a specific capsule design. The resultant preheat is an order of magnitude below the level which could impair target performance.

  1. Heavy ion tumour therapy

    NASA Astrophysics Data System (ADS)

    Scholz, M.

    2000-03-01

    Ion beams represent a promising radiotherapy modality for the treatment of deep seated tumours. Compared to conventional photon beams, in particular beams of heavier ions like e.g. carbon show several advantages which are related to their different physical and radiobiological properties: The dose increases with penetration depth and shows a sharp distal fall off at the end of the particle range, i.e., the depth dose profile is inverted compared to photon beams. They exhibit an increased biological effectiveness in particular at the end of their range and thus in the target volume. The spatial distribution of stopping particles can be monitored by means of PET-techniques making use of the small amount of radioactive projectile fragments. Ion beams were first used for medical applications in 1954 in Berkeley. Since then, several treatment facilities for tumour therapy have been established worldwide, and approximately 25 000 patients have been treated with protons and 3000 patients with heavier ions successfully. As an example, the specific advantages of the heavy ion therapy facility at GSI Darmstadt established in cooperation with the Radiological Clinics and DKFZ Heidelberg and FZ Rossendorf will be described. In contrast to most existing facilities, it is based on an active beam delivery system, using magnetic deflection of a pencil beam (raster scan) and accelerator energy variation to adjust the penetration depth. Thus, an optimal conformation of the dose to the target volume is achieved. PET-measurements allow for a quasi on-line monitoring of the 3D distribution of stopping particles and in particular of the position of the distal edge of the dose distribution. Furthermore, in the treatment planning procedure the radiobiological properties of ion beams are taken into account in great detail. In December 1997, patient treatments started at GSI, and up to now 42 patients were treated with carbon ions alone or in a mixed carbon/photon beam regime.

  2. Double-differential heavy-ion production cross sections.

    PubMed

    Miller, T M; Townsend, L W

    2004-01-01

    Current computational tools used for space or accelerator shielding studies transport energetic heavy ions either using a one-dimensional straight-ahead approximation or by dissociating the nuclei into protons and neutrons and then performing neutron and proton transport using Monte Carlo techniques. Although the heavy secondary particles generally travel close to the beam direction, a proper treatment of the light ions produced in these reactions requires that double-differential cross sections should be utilised. Unfortunately, no fundamental nuclear model capable of serving as an event generator to provide these cross sections for all ions and energies of interest exists currently. Herein, we present a model for producing double-differential heavy-ion production cross sections that uses heavy-ion fragmentation yields produced by the NUCFRG2 fragmentation code coupled with a model of energy degradation in nucleus-nucleus collisions and systematics of momentum distributions to provide energy and angular dependences of the heavy-ion production.

  3. Alkali-silica reaction resistant concrete using pumice blended cement

    NASA Astrophysics Data System (ADS)

    Ramasamy, Uma

    Durability of structures is a major challenge for the building industry. One of the many types of concrete deterioration that can affect durability is alkali-silica reaction (ASR). ASR has been found in most types of concrete structures, including dams, bridges, pavements, and other structures that are 20 to 50 years old. The degradation mechanism of ASR produces a gel that significantly expands in the presence of water as supplied from the surrounding environment. This expansion gel product can create high stresses and cracking of the concrete, which can lead to other forms of degradation and expensive structural replacement costs. The four essential factors that produce an expansive ASR gel in concrete are the presence of alkalis, siliceous aggregate, moisture, and free calcium hydroxide (CH). If concrete is starved of any one of these essential components, the expansion can be prevented. Reducing CH through the use of a supplementary cementitious material (SCM) such as natural pozzolan pumice is the focus of this research. By using a pozzolan, the amount of CH is reduced with time based on the effectiveness of the pozzolan. Many pozzolans exist, but one such naturally occurring pozzolanic material is pumice. This research focuses on determining the effect of a finely ground pumice as a SCM in terms of its resistance to ASR expansion, as well as improving resistance to other potential concrete durability mechanisms. In spite of having high alkali contents in the pumice, mixtures containing the SCM pumice more effectively mitigated the ASR expansion reaction than other degradation mechanisms. Depending on the reactivity of the aggregates and fineness of the pumice, 10-15% replacement of cement with the pumice was found to reduce the ASR expansion to the acceptable limits. The amount of CH remaining in the concrete was compared to the ASR expansion in order to improve understanding of the role of CH in the ASR reaction. Thermo-gravimetric analysis (TGA) and X

  4. Computerized Heavy-Ion Tomography

    NASA Astrophysics Data System (ADS)

    Holley, W. R.; Tobias, C. A.; Fabrikant, J. I.; Llacer, J.; Chu, W. T.; Benton, E. V.

    1981-07-01

    Several techniques for heavy-ion computerized tomography are being investigated at Lawrence Berkeley Laboratory. Using beams of carbon and neon from the Bevalac, we have demonstrated that these methods are feasible and capable of high resolution. We describe in some detail the method of heavy-ion CT imaging using nuclear track detectors, including a discussion of procedures for optical scanning and digitization of data and computerized distortion corrections. Comparisons between a heavy-ion CT image and X-ray CT image of a simple phantom are discussed. Preliminary results from two techniques using active, online detector systems for performing heavy-ion computerized tomography are presented. One method uses a multiplane, multiwire ionization chamber for detecting the heavy ions in a mode allowing true three-dimensional reconstructions. The other technique uses a system of position-sensitive silicon solid-state detectors for spacial information and high-purity germanium detectors to measure accurately the residual energy of the ions.

  5. Swift Heavy Ions in Matter

    NASA Astrophysics Data System (ADS)

    Rothard, Hermann; Severin, Daniel; Trautmann, Christina

    2015-12-01

    The present volume contains the proceedings of the Ninth International Symposium on Swift Heavy Ions in Matter (SHIM). This conference was held in Darmstadt, from 18 to 21 May 2015. SHIM is a triennial series, which started about 25 years ago by a joint initiative of CIRIL - Caen and GSI - Darmstadt, with the aim of promoting fundamental and applied interdisciplinary research in the field of high-energy, heavy-ion interaction processes with matter. SHIM was successively organized in Caen (1989), Bensheim (1992), Caen (1995), Berlin (1998), Catania (2002), Aschaffenburg (2005), Lyon (2008), and Kyoto (2012). The conference attracts scientists from many different fields using high-energy heavy ions delivered by large accelerator facilities and characterized by strong and short electronic excitations.

  6. Accelerators for heavy ion fusion

    SciTech Connect

    Bangerter, R.O.

    1985-10-01

    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.

  7. In situ alkali-silica reaction observed by x-ray microscopy

    SciTech Connect

    Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.; Meyer-Ilse, W.

    1997-04-01

    In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques available for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.

  8. The n-p bremsstrahlung in heavy ion collision processes

    NASA Astrophysics Data System (ADS)

    Blann, M.

    1990-01-01

    The goal is to summarize the current status of the interpretation of energetic gamma-rays in heavy ion collisions via the n-p-bremsstrahlung mechanism. An essential element of the topic is a transport equation to approximate the fast non-equilibrium nucleon-nucleon cascade/emission stage of the heavy ion reactions. It is during this stage that it was expected that the n-p-bremsstrahlung processes produced energetic photons. The Boltzmann master equation (BME) model which will be used as the transport code is briefly described, deferring to earlier works for a more complete description, and present but a single representative comparison with an experimental neutron emission spectrum. The status of the elementary n-p-gamma cross section needed to extend the transport code to photon emission in heavy ion reactions, and the status of these comparisons with data are summarized.

  9. Superconducting heavy ion injector linac

    SciTech Connect

    Shepard, K.W.

    1985-01-01

    A conceptual design for a very low velocity (.007 < v/c < .07) superconducting heavy-ion linac is reviewed. This type of linac may have significant cost and performance advantages over room-temperature linacs, at least for applications requiring modest beam currents. Some general features of the design of very-low velocity superconducting accelerating structures are discussed and a design for a 48.5 MHz, v/c = .009 structure, together with the status of a niobium prototype, is discussed in detail. Preliminary results of a beam dynamics study indicate that the low velocity linac may be able to produce heavy-ion beams with time-energy spreads of a few keV-nsec. 11 refs, 4 figs.

  10. Heavy ion therapy: Bevalac epoch

    SciTech Connect

    Castro, J.R.

    1993-10-01

    An overview of heavy ion therapy at the Bevelac complex (SuperHILac linear accelerator + Bevatron) is given. Treatment planning, clinical results with helium ions on the skull base and uveal melanoma, clinical results with high-LET charged particles, neon radiotherapy of prostate cancer, heavy charged particle irradiation for unfavorable soft tissue sarcoma, preliminary results in heavy charged particle irradiation of bone sarcoma, and irradiation of bile duct carcinoma with charged particles and-or photons are all covered. (GHH)

  11. Central collisions of heavy ions

    SciTech Connect

    Fung, Sun-yiu.

    1992-10-01

    This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1991 to September 30, 1992. During this period, the program focused on particle production at AGS energies, and correlation studies at the Bevalac in nucleus-nucleus central collisions. As part of the PHENIX collaboration, contributions were made to the Preliminary Conceptual Design Report (pCDR), and work on a RHIC silicon microstrip detector R D project was performed.

  12. Heavy Ion Fusion Injector Program

    SciTech Connect

    Yu, S.; Eylon, S.; Chupp, W.W.

    1993-05-01

    A program is underway to construct a 2 MV, 800 mA, K{sup +} injector for heavy ion fusion. The Electrostatic Quadrupole (ESQ) injector configuration consists of a zeolite source, a diode of up to 1 MV, together with several electrostatic quadrupole units to simultaneously focus and accelerate the beam to 2 MV. The key issues of source technology, high voltage breakdown, beam aberrations, and transient effects will be discussed. Results from ongoing experiments and simulations will be presented.

  13. Progress Toward Heavy Ion IFE

    SciTech Connect

    Meier, W R; Logan, B G; Waldron, W L; Sabbi, G L; Callahan-Miller, D A; Peterson, P F; Goodin, D T

    2002-01-17

    Successful development of Heavy Ion Fusion (HIF) will require scientific and technology advances in areas of targets, drivers and chambers. Design work on heavy ion targets indicates that high gain (60-130) may be possible with a -3-6 MJ driver depending on the ability to focus the beams to small spot sizes. Significant improvements have been made on key components of heavy ion drivers, including sources, injectors, insulators and ferromagnetic materials for long-pulse induction accelerator cells, solid-state pulsers, and superconducting quadrupole magnets. The leading chamber concept for HIF is the thick-liquid-wall HYLEE-II design, which uses an array of flibe jets to protect chamber structures from x-ray, debris, and neutron damage. Significant progress has been made in demonstrating the ability to create and control the types of flow needed to form the protective liquid blanket. Progress has also been made on neutron shielding for the final focus magnet arrays with predicted lifetimes now exceeding the life of the power plant. Safety analyses have been completed for the HYLEE-II design using state-of-the-art codes. Work also continues on target fabrication and injection for HE. A target injector experiment capable of > 5 Hz operation has been designed and construction will start in 2002. Methods for mass production of hohlraum targets are being evaluated with small-scale experiments and analyses. Progress in these areas will be reviewed.

  14. Depth-dose relations for heavy ion beams

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1977-01-01

    Radiation transport of heavy ions in matter is of interest to radiological protection in space and high-altitude aircraft. In addition, heavy ion beams are expected to be of advantage in radiotherapy since their characteristic Bragg curve allows a relative reduction of the dose in reaching a tumor site and the near elimination of exposure beyond the tumor region as the beam exits the body. Furthermore, the radioresistance of tumorous cells due to their hypoxic state may be reduced or eliminated by the high specific ionization of heavy ion beams. The depth-dose distribution of heavy ion beams consists of energy deposited by the attenuated primary beam with its characteristic Bragg curve and a relatively unstructured background due to secondary radiations produced in nuclear reactions. As the ion mass increases, the secondary contribution becomes more structured and may add significantly to the Bragg peak of the primary ions. The result for heavy ions (z greater than 20) is a greatly broadened Bragg peak region, especially in comparison to straggling effects, which may prove to be of importance in radiotherapy and biomedical research.

  15. Heavy ion transport in the straight ahead approximation

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1983-01-01

    An as yet unsolved problem in space radiation protection is the necessary relation between the external cosmic ray heavy ion fluence and the resultant environment within the spacecraft. Such a relation involves the transport of such ions through extended materials. Presented is a derivation of the solution of the transport equation for heavy ions in the straight ahead approximation for directed beam applications. An iterative scheme for the solution of the inhomogeneous integral transport equations is applied to a neon ion beam in water. The iterative scheme requires transport coefficients as input, which are determined from the available data on ion nuclear reactions. The iteration converged for the neon beam in water. Thus this iterative scheme appears to be a suitable approximation of heavy ion transport.

  16. Heavy ion collisions and the pre-equilibrium exciton model

    SciTech Connect

    Betak, E.

    2012-10-20

    We present a feasible way to apply the pre-equilibrium exciton model in its masterequation formulation to heavy-ion induced reactions including spin variables. Emission of nucleons, {gamma}'s and also light clusters is included in our model.

  17. Electromagnetic dissociation effects in galactic heavy-ion fragmentation

    NASA Technical Reports Server (NTRS)

    Norbury, J. W.; Townsend, L. W.

    1986-01-01

    Methods for calculating cross sections for the breakup of galactic heavy ions by the Coulomb fields of the interacting nuclei are presented. By using the Weizsacker-Williams method of virtual quanta, estimates of electromagnetic dissociation cross sections for a variety of reactions applicable to galactic cosmic ray shielding studies are presented and compared with other predictions and with available experimental data.

  18. Chromosome Aberrations by Heavy Ions

    NASA Astrophysics Data System (ADS)

    Ballarini, Francesca; Ottolenghi, Andrea

    It is well known that mammalian cells exposed to ionizing radiation can show different types of chromosome aberrations (CAs) including dicentrics, translocations, rings, deletions and complex exchanges. Chromosome aberrations are a particularly relevant endpoint in radiobiology, because they play a fundamental role in the pathways leading either to cell death, or to cell conversion to malignancy. In particular, reciprocal translocations involving pairs of specific genes are strongly correlated (and probably also causally-related) with specific tumour types; a typical example is the BCR-ABL translocation for Chronic Myeloid Leukaemia. Furthermore, aberrations can be used for applications in biodosimetry and more generally as biomarkers of exposure and risk, that is the case for cancer patients monitored during Carbon-ion therapy and astronauts exposed to space radiation. Indeed hadron therapy and astronauts' exposure to space radiation represent two of the few scenarios where human beings can be exposed to heavy ions. After a brief introduction on the main general features of chromosome aberrations, in this work we will address key aspects of the current knowledge on chromosome aberration induction, both from an experimental and from a theoretical point of view. More specifically, in vitro data will be summarized and discussed, outlining important issues such as the role of interphase death/mitotic delay and that of complex-exchange scoring. Some available in vivo data on cancer patients and astronauts will be also reported, together with possible interpretation problems. Finally, two of the few available models of chromosome aberration induction by ionizing radiation (including heavy ions) will be described and compared, focusing on the different assumptions adopted by the authors and on how these models can deal with heavy ions.

  19. Exotics from Heavy Ion Collisions

    SciTech Connect

    Ohnishi, Akira; Jido, Daisuke; Cho, Sungtae; Furumoto, Takenori; Yazaki, Koichi; Hyodo, Tetsuo; Ko, Che Ming; Lee, Su Houng; Nielsen, Marina; Sekihara, Takayasu; Yasui, Shigehiro

    2011-10-21

    Discriminating hadronic molecular and multi-quark states is a long standing problem in hadronic physics. We propose here to utilize relativistic heavy ion collisions to resolve this problem, as exotic hadron yields are expected to be strongly affected by their structures. Using the coalescence model, we find that the exotic hadron yield relative to the statistical model result is typically an order of magnitude smaller for a compact multi-quark state, and larger by a factor of two or more for a loosely bound hadronic molecule. We further find that some of the newly proposed heavy exotic states could be produced and realistically measured at RHIC and LHC.

  20. RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT

    SciTech Connect

    Friedlander, Erwin M.; Heckman, Harry H.

    1982-04-01

    Relativistic heavy ion physics began as a 'no man's land' between particle and nuclear physics, with both sides frowning upon it as 'unclean', because on one hand, hadronic interactions and particle production cloud nuclear structure effects, while on the other, the baryonic environment complicates the interpretation of production experiments. They have attempted to review here the experimental evidence on RHI collisions from the point of view that it represents a new endeavor in the understanding of strong interaction physics. Such an approach appears increasingly justified; first, by the accumulation of data and observations of new features of hadronic interactions that could not have been detected outside a baryonic environment; second, by the maturation of the field owing to the advances made over the past several years in experimental inquiries on particle production by RHI, including pions, kaons, hyperons, and searches for antiprotons; and third, by the steady and progressive increase in the energy and mass ranges of light nuclear beams that have become available to the experiment; indeed the energy range has widened from the {approx} 0.2 to 2 AGeV at the Bevalac to {approx}4 AGeV at Dubna and recently, to the quantum jump in energies to {approx} 1000 equivalent AGeV at the CERN PS-ISR. Accompanying these expansions in the energy frontier are the immediate prospects for very heavy ion beams at the Bevalac up to, and including, 1 AGeV {sup 238}U, thereby extending the 'mass frontier' to its ultimate extent.

  1. The Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Fischer, Wolfram

    The Relativistic Heavy Ion Collider (RHIC), shown in Fig. 1, was build to study the interactions of quarks and gluons at high energies [Harrison, Ludlam and Ozaki (2003)]. The theory of Quantum Chromodynamics (QCD) describes these interactions. One of the main goals for the RHIC experiments was the creation and study of the Quark-Gluon Plasma (QGP), which was expected to be formed after the collision of heavy ions at a temperature of approximately 2 trillion kelvin (or equivalently an energy of 150 MeV). The QGP is the substance which existed only a few microseconds after the Big Bang. The QGP was anticipated to be weakly interacting like a gas but turned out to be strongly interacting and more like a liquid. Among its unusual properties is its extremely low viscosity [Auerbach and Schlomo (2009)], which makes the QGP the substance closest to a perfect liquid known to date. The QGP is opaque to moderate energy quarks and gluons leading to a phenomenon called jet quenching, where of a jet and its recoil jet only one is observable and the other suppressed after traversing and interacting with the QGP [Jacak and Müller (2012)]...

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

    DOEpatents

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

    1998-07-21

    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.

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

    DOEpatents

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

    1999-02-16

    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.

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

    DOEpatents

    Fries, David P.; Browning, James F.

    1999-01-01

    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.

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

    DOEpatents

    Fries, David P.; Browning, James F.

    1998-01-01

    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.

  6. Progress in Heavy Ion Fusion

    SciTech Connect

    Herrmannsfeldt, W.B.

    1988-09-01

    The progress of the field of Heavy Ion Fusion has been documented in the proceedings of the series of International Symposia that, in recent years, have occurred every second year. The latest of these conferences was hosted by Gesellshaft fuer Schwerionenforshung (GSI) in Darmstadt, West Germany, June 28-30, 1988. For this report, a few highlights from the conference are selected, stressing experimental progress and prospects for future advances. A little extra time is devoted to report on the developments at the Lawrence Berkeley Laboratory (LBL) which is the center for most of the HIFAR program. The Director of the HIFAR program at LBL is Denis Keefe, who presented the HIF report at the last two of the meetings in this series, and in whose place the author is appearing now. 4 refs., 1 fig.

  7. NUCLEAR AND HEAVY ION PHYSICS: Measurement of the astrophysical S factor for the low energy 2H(d,γ)4He reaction

    NASA Astrophysics Data System (ADS)

    Zhou, Jing; Fu, Yuan-Yong; Zhou, Shu-Hua; Xia, Hai-Hong; Li, Cheng-Bo; Meng, Qiu-Ying

    2009-05-01

    The γ-rays and protons from an Ed = 20 keV deuteron beam incident on a D—Ti target were measured. A branching ratio of the 2H(d,γ)4 He reaction versus the 2H(d,p) 3H reaction of Γγ/Γp = (1.06 ± 0.34) × 10-7 has been obtained, and the astrophysical S factor of the 2H(d,γ)4 He reaction at the center of mass energy Ecm approx 7 keV of (6.0 ± 2.4) × 10-6 keV·b was deduced.

  8. Detection of alkali-silica reaction swelling in concrete by staining

    DOEpatents

    Guthrie, Jr., George D.; Carey, J. William

    1998-01-01

    A method using concentrated aqueous solutions of sodium cobaltinitrite and rhodamine B is described which can be used to identify concrete that contains gels formed by the alkali-silica reaction (ASR). These solutions present little health or environmental risk, are readily applied, and rapidly discriminate between two chemically distinct gels; K-rich, Na--K--Ca--Si gels are identified by yellow staining, and alkali-poor, Ca--Si gels are identified by pink staining.

  9. Detection of alkali-silica reaction swelling in concrete by staining

    DOEpatents

    Guthrie, G.D. Jr.; Carey, J.W.

    1998-04-14

    A method using concentrated aqueous solutions of sodium cobalt nitrite and rhodamine B is described which can be used to identify concrete that contains gels formed by the alkali-silica reaction (ASR). These solutions present little health or environmental risk, are readily applied, and rapidly discriminate between two chemically distinct gels; K-rich, Na-K-Ca-Si gels are identified by yellow staining, and alkali-poor, Ca-Si gels are identified by pink staining.

  10. Relation of expansion due to alkali silica reaction to the degree of reaction measured by SEM image analysis

    SciTech Connect

    Haha, M. Ben; Gallucci, E. Guidoum, A.; Scrivener, K.L.

    2007-08-15

    Scanning Electron Microscopy Image Analysis (SEM-IA) was used to quantify the degree of alkali silica reaction in affected microbars, mortar and concrete prisms. It was found that the degree of reaction gave a unique correlation with the macroscopic expansion for three different aggregates, stored at three temperatures and with two levels of alkali. The relationships found for the concretes and the mortars overlap when normalised by the aggregate content. This relationship seems to be linear up to a critical reaction degree which coincides with crack initiation within the reactive aggregates.

  11. Integrated experiments for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Barnard, J. J.; Ahle, L. E.; Bieniosek, F. M.; Celata, C. M.; Davidson, R. C.; Henestroza, E.; Friedman, A.; Kwan, J. W.; Logan, B. G.; Lee, E. P.; Lund, S. M.; Meier, W. R.; Sabbi, G.-L.; Seidl, P. A.; Sharp, W. M.; Shuman, D. B.; Waldron, W. L.; Qin, H.; Yu, S. S.

    2003-10-01

    We describe the next set of experiments proposed in the U.S. Heavy Ion Fusion Virtual National Laboratory, the so-called Integrated Beam Experiment (IBX). The purpose of IBX is to investigate in an integrated manner the processes and manipulations necessary for a heavy ion fusion induction accelerator. The IBX experiment will demonstrate injection, acceleration, compression, bending, and final focus of a heavy ion beam at significant line charge density. Preliminary conceptual designs are presented and issues and trade-offs are discussed. Plans are also described for the step after IBX, the Integrated Research Experiment (IRE), which will carry out significant target experiments.

  12. Heavy Ion Fusion Accelerator Research (HIFAR)

    SciTech Connect

    Not Available

    1991-04-01

    This report discusses the following topics: emittance variations in current-amplifying ion induction lina; transverse emittance studies of an induction accelerator of heavy ions; drift compression experiments on MBE-4 and related emittance; low emittance uniform- density C{sub s}+ sources for heavy ion fusion accelerator studies; survey of alignment of MBE-4; time-of-flight dependence on the MBE-4 quadrupole voltage; high order calculation of the multiple content of three dimensional electrostatic geometries; an induction linac injector for scaled experiments; induction accelerator test module for HIF; longitudinal instability in HIF beams; and analysis of resonant longitudinal instability in a heavy ion induction linac.

  13. Quasimolecular single-nucleon effects in heavy-ion collisions

    SciTech Connect

    Erb, K.A.

    1984-01-01

    Several experimental examples are discussed to illustrate that single-particle molecular orbital behavior has become an established reality in nuclear physics over the last several years. Measurements and analyses of inelastic scattering in the /sup 13/C + /sup 12/C and /sup 17/O + /sup 12/C systems, and of neutron transfer in the /sup 13/C(/sup 13/C, /sup 12/C)/sup 14/C reaction, show that the motion of valence nucleons can be strongly and simultaneously influenced by both collision partners in heavy-ion collisions. This bvehavior is characteristic of a molecular (single-particle) rather than a direct (DWBA) mechanism: it demonstrates that the single-particle analog of atomic molecular motion plays an important role in nuclear reactions at bombarding energies near the Coulomb barrier. Such behavior may be even more pronounced in the collisions of massive nuclei that will be studied with the new generation of heavy-ion accelerators. 19 references.

  14. Relativistic heavy ion fragmentation at HISS (Heavy Ion Spectrometer System)

    SciTech Connect

    Tull, C.E.

    1990-10-01

    An experiment was conducted at the Lawrence Berkeley Laboratory to measure projectile fragmentation of relativistic heavy ions. Charge identification was obtained by the use of a Cerenkov Hodoscope operating above the threshold for total internal reflection, while velocity measurement was performed by use of a second set of Cerenkov radiators operating at the threshold for total internal reflection. Charge and mass resolution for the system was {sigma}{sub Z} = 0.2 e and {sigma}{sub A} = 0.2 u. Measurements of the elemental and isotopic production cross sections for the fragmentation of {sup 40}Ar at 1.65{center dot}A GeV have been compared with an Abrasion-Ablation Model based on the evaporation computer code GEMINI. The model proves to be an accurate predictor of the cross sections for fragments between Chlorine and Boron. The measured cross section were reproduced using simple geometry with charge dispersions induced by zero-point vibrations of the giant dipole resonance for the prompt abrasion stage, and injecting an excitation energy spectrum based on a final state interaction with scaling factor E{sub fsi} = 38.8 MeV/c. Measurement of the longitudinal momentum distribution widths for projectile fragments are consistent with previous experiment and can be interpreted as reflecting the Fermi momentum distribution in the initial projectile nucleus. Measurement of the transverse momentum indicate an additional, unexplained dependence of the reduced momentum widths on fragment mass. This dependence has the same sign and similar slope to previously measured fragments of {sup 139}La, and to predictions based on phase-space constraints on the final state of the system.

  15. Heavy-ion versus {sup 3}He/{sup 4}He fusion-fission reactions: Angular momentum dependence of dissipation in nuclear fission

    SciTech Connect

    Ye, W.

    2011-09-15

    The stochastic Langevin model is employed to study dissipation properties in fission in the {sup 16}O + {sup 181}Ta {yields}{sup 197}Tl system by analyzing prescission neutron yields measured in this reaction. It has been found that the {sup 197}Tl nuclei undergo fission that is not in accordance with the standard Bohr-Wheeler statistical theory. A detailed comparison with previously published work in which fission excitation functions measured in {sup 3,4}He + {sup 197}Au {yields}{sup 200,201}Tl are shown to be in excellent agreement with the fission width formula predicted by the traditional models of nuclear fission suggests that nuclear dissipation strength may have an angular momentum dependence in addition to the known deformation and temperature dependence. Implications for the basic understanding of the observed abnormal rise in prescission particles at high energy and the need for further experimental confirmations are discussed.

  16. Observation of high-j quasiparticle states in {sup 249}Cm by in-beam {gamma}-ray spectroscopy using heavy-ion transfer reactions

    SciTech Connect

    Ishii, T.; Makii, H.; Asai, M.; Tsukada, K.; Toyoshima, A.; Matsuda, M.; Makishima, A.; Shigematsu, S.; Kohno, T.; Kaneko, J.; Ogawa, M.; Shizuma, T.; Toume, H.; Hossain, I.

    2008-11-15

    We have measured de-excitation {gamma} rays in {sup 249}Cm populated by one-neutron stripping reactions with a {sup 248}Cm target and 162-MeV {sup 16}O, 162-MeV {sup 18}O, and 120-MeV {sup 13}C beams. {gamma} rays in {sup 249}Cm were identified by measuring kinetic energies of outgoing particles using Si {delta}E-E detectors. It was demonstrated that high-j orbitals were selectively populated in the ({sup 16}O, {sup 15}O) reaction having a large negative Q value. We have observed eight quasiparticle states above the deformed shell gap of N=152. The 1/2{sup +}[620], 1/2{sup -}[750], and 7/2{sup +}[613] bands were extended up to 19/2{sup +}, 19/2{sup -}, and 13/2{sup +} states, respectively. We have established the 9/2 9/2{sup +}[615] state at 526 keV, the 9/2 9/2{sup +}[604] state with a short life of T{sub 1/2}<<2 ps at 1030 keV, and the 11/2 11/2{sup -}[725] state with T{sub 1/2}=19(1) ns at 375 keV. Furthermore, the 17/2 1/2{sup +}[880] state, having a large component of the k{sub 17/2} spherical single-particle state, has been identified at 1505 keV. We discuss the properties of those quasiparticle states in the framework of a deformed shell model.

  17. Use of ground clay brick as a pozzolanic material to reduce the alkali-silica reaction

    SciTech Connect

    Turanli, L.; Bektas, F.; Monteiro, P.J.M

    2003-10-01

    The objective of this experimental study was to use ground clay brick (GCB) as a pozzolanic material to minimize the alkali-silica reaction expansion. Two different types of clay bricks were finely ground and their activity indices were determined. ASTM accelerated mortar bar tests were performed to investigate the effect of GCB when used to replace cement mass. The microstructure of the mortar was investigated using scanning electron microscopy (SEM). The results showed that the GCBs meet the strength activity requirements of ASTM. In addition, the GCBs were found to be effective in suppressing the alkali-silica reaction expansion. The expansion decreased as the amount of GCBs in the mortar increased.

  18. Historical aspects of heavy ion radiotherapy

    SciTech Connect

    Raju, M.R.

    1995-03-01

    This paper presents historical developments of heavy-ion radiotherapy including discussion of HILAC and HIMAC and discussion of cooperation between Japan and the United States, along with personal reflections.

  19. Jets in relativistic heavy ion collisions

    SciTech Connect

    Wang, Xin-Nian; Gyulassy, M.

    1990-09-01

    Several aspects of hard and semihard QCD jets in relativistic heavy ion collisions are discussed, including multiproduction of minijets and the interaction of a jet with dense nuclear matter. The reduction of jet quenching effect in deconfined phase of nuclear matter is speculated to provide a signature of the formation of quark gluon plasma. HIJING Monte Carlo program which can simulate events of jets production and quenching in heavy ion collisions is briefly described. 35 refs., 13 figs.

  20. Heavy-ion physics with CMS

    NASA Astrophysics Data System (ADS)

    Betts, R. R.; CMS Collaboration

    2007-08-01

    The Large Hadron Collider (LHC) at CERN will collide protons at \\sqrt{s_NN} = 14 \\ TeV and lead ions at \\sqrt{s_NN} = 5.5 \\ TeV . The research program of the Compact Muon Solenoid (CMS) experiment includes a strong heavy-ion physics agenda, especially in the measurement of hard processes. The high centre-of-mass energies available at the LHC will allow high statistics studies of high-density QCD with hard probes: heavy quarks and quarkonia with an emphasis on the J/ψ and Upsilon, high-pT jets, direct photons as well as Z0 bosons. In addition to the detailed studies of hard probes, CMS will measure charged particle multiplicity and energy flow with respect to the reaction plane on an event-by-event basis. Studies of the CMS capabilities and physics reach for different high-density QCD observables, using the full detector simulation and reconstruction, are presented.

  1. Research in Heavy Ion Nuclear Reactions

    SciTech Connect

    Petitt, G.A.; Nelson, W.H.; He, Xiaochun; Lee, W.

    1999-04-14

    This is the final progress report for the experimental nuclear physics program at Georgia State University (GSU) under the leadership of Gus Petitt. In June, 1996, Professor Petitt retired for health reasons and the DOE contract was extended for another year to enable the group to continue it's work. This year has been a productive one. The group has been heavily involved in the E866 experiment at Fermilab where we have taken on the responsibility of developing a new level-3 trigger for the experiment. Bill Lee, the graduate student in our group expects to obtain his thesis data from the run extension currently in progress, which focuses on the A dependence of J/{psi}'s and {Upsilon}'s from beryllium, tungsten, and iron targets. In the past year and a half the GSU group has led the development of a new level-3 software trigger system for E866. Our work on this project is described.

  2. Coulomb explosion during the early stages of the reaction of alkali metals with water.

    PubMed

    Mason, Philip E; Uhlig, Frank; Vaněk, Václav; Buttersack, Tillmann; Bauerecker, Sigurd; Jungwirth, Pavel

    2015-03-01

    Alkali metals can react explosively with water and it is textbook knowledge that this vigorous behaviour results from heat release, steam formation and ignition of the hydrogen gas that is produced. Here we suggest that the initial process enabling the alkali metal explosion in water is, however, of a completely different nature. High-speed camera imaging of liquid drops of a sodium/potassium alloy in water reveals submillisecond formation of metal spikes that protrude from the surface of the drop. Molecular dynamics simulations demonstrate that on immersion in water there is an almost immediate release of electrons from the metal surface. The system thus quickly reaches the Rayleigh instability limit, which leads to a 'coulomb explosion' of the alkali metal drop. Consequently, a new metal surface in contact with water is formed, which explains why the reaction does not become self-quenched by its products, but can rather lead to explosive behaviour.

  3. Alkali-silica reaction products: Comparison between samples from concrete structures and laboratory test specimens

    SciTech Connect

    Sachlova, Sarka Prikryl, Richard; Pertold, Zdenek

    2010-12-15

    Alkali-silica gels (ASG) were investigated in concrete from bridge structures (constructed from the 1920s to 2000), as well as in experimental specimens; employing optical microscopy, petrographic image analysis, and scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS). The main differences were found in the chemical composition and morphology of the ASGs. ASGs which had formed in older concrete samples (50-80 years old) show a partly crystalline structure and higher Ca{sup 2+} content, indicating their aging and maturation. Younger concrete samples and experimental test specimens exhibit the presence of amorphous ASG. The chemistry of ASG from experimental specimens reflects the chemical composition of accelerating solutions. - Research Highlights: {yields} Quantitative analysis of alkali-silica gels {yields} Comparison of ASR in experimental conditions with ASR in bridge structures {yields} Investigation of factors affecting alkali-silica reaction {yields} Investigation of ASR of different types of aggregates.

  4. Heavy-ion radiolysis of cyclooctane

    SciTech Connect

    LaVerne, J.A.; Wojnarovits, L.

    1995-06-15

    The major products produced in radiolysis of cyclooctane with 1-15 MeV protons, 10-30 MeV carbon ions, and 20-30 MeV oxygen ions were investigated in the absence and presence of iodine radical scavenger and compared with the {gamma} and 5-20 MeV helium ion radiolysis published in a previous work. While almost 70% of the cyclooctyl radicals survive until a few microseconds in {gamma}-radiolysis, the yields with carbon ions and oxygen ions are about an order of magnitude lower. It appears that all of the hydrogen atoms produced in {gamma}-radiolysis react by hydrogen atom abstraction from the medium molecules, whereas in the heavy-ion tracks enhanced intratrack reactions eliminate most of the hydrogen atoms before such reactions can occur to any significant extent. The yield of products derived from the excited singlet state steadily decreases with the linear energy transfer (LET), and in carbon and oxygen ion radiolysis its yield is less than 20% of that found in {gamma}-radiolysis. Product formation through radical mechanisms first slightly increases with particle LET until about 50 eV/nm, and then the total yields of all products decrease to half of that found in {gamma}-radiolysis. Much of the change in product yields with increasing LET can be explained by a radical mechanism, but it also appears that there is a change in initial radical formation due to a shift toward an increased probability of triplet excited-state formation over that of singlet excited states. 27 refs., 9 figs., 3 tabs.

  5. Skyrme tensor force in heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Stevenson, P. D.; Suckling, E. B.; Fracasso, S.; Barton, M. C.; Umar, A. S.

    2016-05-01

    Background: It is generally acknowledged that the time-dependent Hartree-Fock (TDHF) method provides a useful foundation for a fully microscopic many-body theory of low-energy heavy ion reactions. The TDHF method is also known in nuclear physics in the small-amplitude domain, where it provides a useful description of collective states, and is based on the mean-field formalism, which has been a relatively successful approximation to the nuclear many-body problem. Currently, the TDHF theory is being widely used in the study of fusion excitation functions, fission, and deep-inelastic scattering of heavy mass systems, while providing a natural foundation for many other studies. Purpose: With the advancement of computational power it is now possible to undertake TDHF calculations without any symmetry assumptions and incorporate the major strides made by the nuclear structure community in improving the energy density functionals used in these calculations. In particular, time-odd and tensor terms in these functionals are naturally present during the dynamical evolution, while being absent or minimally important for most static calculations. The parameters of these terms are determined by the requirement of Galilean invariance or local gauge invariance but their significance for the reaction dynamics have not been fully studied. This work addresses this question with emphasis on the tensor force. Method: The full version of the Skyrme force, including terms arising only from the Skyrme tensor force, is applied to the study of collisions within a completely symmetry-unrestricted TDHF implementation. Results: We examine the effect on upper fusion thresholds with and without the tensor force terms and find an effect on the fusion threshold energy of the order several MeV. Details of the distribution of the energy within terms in the energy density functional are also discussed. Conclusions: Terms in the energy density functional linked to the tensor force can play a non

  6. Process in high energy heavy ion acceleration

    NASA Astrophysics Data System (ADS)

    Dinev, D.

    2009-03-01

    A review of processes that occur in high energy heavy ion acceleration by synchrotrons and colliders and that are essential for the accelerator performance is presented. Interactions of ions with the residual gas molecules/atoms and with stripping foils that deliberately intercept the ion trajectories are described in details. These interactions limit both the beam intensity and the beam quality. The processes of electron loss and capture lie at the root of heavy ion charge exchange injection. The review pays special attention to the ion induced vacuum pressure instability which is one of the main factors limiting the beam intensity. The intrabeam scattering phenomena which restricts the average luminosity of ion colliders is discussed. Some processes in nuclear interactions of ultra-relativistic heavy ions that could be dangerous for the performance of ion colliders are represented in the last chapter.

  7. Reactions between cold methyl halide molecules and alkali-metal atoms

    SciTech Connect

    Lutz, Jesse J.; Hutson, Jeremy M.

    2014-01-07

    We investigate the potential energy surfaces and activation energies for reactions between methyl halide molecules CH{sub 3}X (X = F, Cl, Br, I) and alkali-metal atoms A (A = Li, Na, K, Rb) using high-level ab initio calculations. We examine the anisotropy of each intermolecular potential energy surface (PES) and the mechanism and energetics of the only available exothermic reaction pathway, CH{sub 3}X + A → CH{sub 3} + AX. The region of the transition state is explored using two-dimensional PES cuts and estimates of the activation energies are inferred. Nearly all combinations of methyl halide and alkali-metal atom have positive barrier heights, indicating that reactions at low temperatures will be slow.

  8. New developments in heavy ion fusion

    SciTech Connect

    Herrmannsfeldt, W.B.

    1983-04-01

    Beginning in 1984, the US Department of Energy plans a program aimed at determining the feasibility of using heavy ion accelerators as pellet drivers for Inertial Confinement Fusion (ICF). This paper will describe the events in the field of Heavy Ion Fusion (HIF) that have occurred in the three years since the Lausanne conference in this series. The emphasis will be on the events leading towards the new energy oriented program. in addition to providing an overview of progress in HIF, such a discussion may prove useful for promoters of any emerging energy technology.

  9. Solenoid transport for heavy ion fusion

    SciTech Connect

    Lee, Edward

    2004-06-15

    Solenoid transport of high current, heavy ion beams is considered for several stages of a heavy ion fusion driver. In general this option is more efficient than magnetic quadrupole transport at sufficiently low kinetic energy and/or large e/m, and for this reason it has been employed in electron induction linacs. Ideally an ion beam would be transported in a state of Brillouin flow, i.e. cold in the transverse plane and spinning at one half the cyclotron frequency. The design of appropriate solenoids and the equilibrium and stability of transported ion beams are discussed. An outline of application to a fusion driver is also presented.

  10. Jets In Heavy Ion Collisions with CMS

    NASA Astrophysics Data System (ADS)

    Salur, Sevil

    2016-08-01

    Jet physics in heavy ion collisions is a rich field which has been rapidly evolving since the first observations of medium interactions at RHIC through back-to-back hadron correlations and at LHC via reconstructed jets. In order to completely characterize the final state via jet-medium interactions and distinguish between competing energy loss mechanisms, complementary and robust jet observables are investigated. Latest developments of jet finding techniques and their applications to heavy ion environments are discussed with an emphasis given on experimental results from CMS experiment.

  11. Physics Issues of Heavy-Ion-Beam-Driven Inertial Confinement Fusion*

    NASA Astrophysics Data System (ADS)

    Celata, Christine

    2003-04-01

    The heavy ion fusion concept envisions using of the order of a hundred intense few-GeV ion beams to implode an inertial fusion target, in order to produce commercial electricity using nuclear fusion reactions. The current density of the beams is high enough that each beam is a nonneutral plasma, with dynamics dominated by space charge. The stability, wave phenomena, and nonlinear dynamics of such a system then determine whether beam quality can be preserved through the length of the accelerator and final focus, so that an adequate focus on target occurs. Five experiments are currently exploring the physics of the transport, neutralization, and focusing of these intense heavy ion beams. The targets for heavy ion fusion build upon the work done for indirect drive, laser targets for the National Ignition Facility (NIF). Many of the fundamental target physics issues for heavy ion targets will be addressed on NIF. Using these targets for a power plant adds additional issues, including heavy ion beam/target interactions, the interface with the fusion chamber, and mass-production of targets. In this paper the physics issues for heavy ion fusion will be discussed, and results from both the experimental program and an extensive simulation program will be shown.

  12. Alteration of alkali reactive aggregates autoclaved in different alkali solutions and application to alkali-aggregate reaction in concrete (II) expansion and microstructure of concrete microbar

    SciTech Connect

    Lu Duyou . E-mail: duyoulu@njut.edu.cn; Mei Laibao; Xu Zhongzi; Tang Mingshu; Mo Xiangyin; Fournier, Benoit

    2006-06-15

    The effect of the type of alkalis on the expansion behavior of concrete microbars containing typical aggregate with alkali-silica reactivity and alkali-carbonate reactivity was studied. The results verified that: (1) at the same molar concentration, sodium has the strongest contribution to expansion due to both ASR and ACR, followed by potassium and lithium; (2) sufficient LiOH can completely suppress expansion due to ASR whereas it can induce expansion due to ACR. It is possible to use the duplex effect of LiOH on ASR and ACR to clarify the ACR contribution when ASR and ACR may coexist. It has been shown that a small amount of dolomite in the fine-grained siliceous Spratt limestone, which has always been used as a reference aggregate for high alkali-silica reactivity, might dedolomitize in alkaline environment and contribute to the expansion. That is to say, Spratt limestone may exhibit both alkali-silica and alkali-carbonate reactivity, although alkali-silica reactivity is predominant. Microstructural study suggested that the mechanism in which lithium controls ASR expansion is mainly due to the favorable formation of lithium-containing less-expansive product around aggregate particles and the protection of the reactive aggregate from further attack by alkalis by the lithium-containing product layer.

  13. Alkali metal mediated C-C bond coupling reaction

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto

    2015-02-01

    Metal catalyzed carbon-carbon (C-C) bond formation is one of the important reactions in pharmacy and in organic chemistry. In the present study, the electron and hole capture dynamics of a lithium-benzene sandwich complex, expressed by Li(Bz)2, have been investigated by means of direct ab-initio molecular dynamics method. Following the electron capture of Li(Bz)2, the structure of [Li(Bz)2]- was drastically changed: Bz-Bz parallel form was rapidly fluctuated as a function of time, and a new C-C single bond was formed in the C1-C1' position of Bz-Bz interaction system. In the hole capture, the intermolecular vibration between Bz-Bz rings was only enhanced. The mechanism of C-C bond formation in the electron capture was discussed on the basis of theoretical results.

  14. Alkali metal mediated C–C bond coupling reaction

    SciTech Connect

    Tachikawa, Hiroto

    2015-02-14

    Metal catalyzed carbon-carbon (C–C) bond formation is one of the important reactions in pharmacy and in organic chemistry. In the present study, the electron and hole capture dynamics of a lithium-benzene sandwich complex, expressed by Li(Bz){sub 2}, have been investigated by means of direct ab-initio molecular dynamics method. Following the electron capture of Li(Bz){sub 2}, the structure of [Li(Bz){sub 2}]{sup −} was drastically changed: Bz–Bz parallel form was rapidly fluctuated as a function of time, and a new C–C single bond was formed in the C{sub 1}–C{sub 1}′ position of Bz–Bz interaction system. In the hole capture, the intermolecular vibration between Bz–Bz rings was only enhanced. The mechanism of C–C bond formation in the electron capture was discussed on the basis of theoretical results.

  15. Petrography study on altered flint aggregate by alkali-silica reaction

    SciTech Connect

    Bulteel, D. . E-mail: bulteel@ensm-douai.fr; Rafai, N.; Degrugilliers, P.; Garcia-Diaz, E.

    2004-11-15

    The aim of our study is to improve our understanding of an alkali-silica reaction (ASR) via petrography. We used a chemical concrete subsystem: flint aggregate, portlandite and KOH. The altered flint aggregate is followed by optical microscopy and scanning electron microscopy (SEM) before and after acid treatment at different intervals. After acid treatment, the observations showed an increase in aggregate porosity and revealed internal degradation of the aggregate. This degradation created amorphous zones. Before acid treatment, the analyses on polished sections by scanning electron microscopy coupled with energy dispersive spectroscopy (EDS) enabled visualization of K{sup +} and Ca{sup 2+} penetration into the aggregate. The appearance of amorphous zones and penetration of positive ions into the aggregate are correlated with the increase in the molar fraction of silanol sites. This degradation is specific to the alkali-silica reaction.

  16. Heavy ion beams for inertial fusion

    SciTech Connect

    Godlove, T.F.; Herrmannsfeldt, W.B.

    1980-05-01

    The United States' program in inertial confinement fusion (ICF) is described in this paper, with emphasis on the studies of the use of intense high energy beams of heavy ions to provide the power and energy needed to initiate thermonuclear burn. Preliminary calculations of the transport of intense ion beams in an electrostatic quadrupole focussing structure are discussed.

  17. Super high energy heavy ion collisions

    SciTech Connect

    Geist, W.M.

    1987-12-01

    Basic theoretical ideas on a phase transition to a plasma of free quarks and gluons in heavy ion collisions are outlined. First results from experiments with oxygen beams at 14.5 GeV/c/N (BNL), 60 and 200 GeV/c/N (CERN) are discussed. 30 refs., 9 figs.

  18. Green's function methods in heavy ion shielding

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Costen, Robert C.; Shinn, Judy L.; Badavi, Francis F.

    1993-01-01

    An analytic solution to the heavy ion transport in terms of Green's function is used to generate a highly efficient computer code for space applications. The efficiency of the computer code is accomplished by a nonperturbative technique extending Green's function over the solution domain. The computer code can also be applied to accelerator boundary conditions to allow code validation in laboratory experiments.

  19. Relativistic Hydrodynamics for Heavy-Ion Collisions

    ERIC Educational Resources Information Center

    Ollitrault, Jean-Yves

    2008-01-01

    Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…

  20. Pion probes of heavy ion collision dynamics

    SciTech Connect

    Rasmussen, J.O.

    1985-03-01

    Pion interferometry data (2-pion correlation) are examined for information on size and lifetime of the pion-emitting matter. The temperatures inferred from pion, proton and kaon spectra are considered. An explanation consistent with the above size and temperature data is proposed. New theoretical Monte Carlo results on spectator effects on heavy-ion pion spectra are presented. 23 refs., 9 figs.

  1. Cataracts Heavy Ions and Individual Susceptibility

    NASA Astrophysics Data System (ADS)

    Hall, E.; Worgul, B.; Brenner, D.; Smilenov, L.

    Ocular cataracts represents one of the few legacies of space flight evident in a significant proportion of astronauts X-rays are known to induce cataracts Heavy ions are known to be much more effective per unit dose than gamma -rays The object of this present study was to identify genes that confer individual susceptibility and to estimate RBE values Wild type mice were compared with animals heterozygous for Atm Mrad9 or BRCA1 or animals that were double heterozygotes for pairs of genes Mice were irradiated with x-rays at Columbia University in New York City or with heavy ions 1GeV amu 56 Fe ions at Brookhaven National Laboratory Haploinsufficiency for either Atm or mRAD9 resulted in cataracts appearing earlier than in wild type animals whether exposed to gamma -rays or heavy ions Double heterozygotes were more radiosensitive than animals haploinsufficient for either gene alone Heavy ions were much more effective than x-rays in inducing cataracts of all grades in animals of all genotypes A detailed analysis suggest that the RBE varies to some extent with the genotype of the animal and the cataract grade

  2. Cellular track model for study of heavy ion beams

    NASA Technical Reports Server (NTRS)

    Shinn, Judy L.; Katz, Robert; Cucinotta, Francis A.; Wilson, John W.; Ngo, Duc M.

    1993-01-01

    Track theory is combined with a realistic model of a heavy ion beam to study the effects of nuclear fragmentation on cell survival and biological effectiveness. The effects of secondary reaction products are studied as a function of depth in a water column. Good agreement is found with experimental results for the survival of human T-l cells exposed to monoenergetic carbon, neon, and argon beams under aerobic and hypoxia conditions. The present calculation, which includes the effect of target fragmentation, is a significant improvement over an earlier calculation because of the use of a vastly improved beam model with no change in the track theory or cellular response parameters.

  3. Clinical trial of cancer therapy with heavy ions at heavy ion research facility in lanzhou

    NASA Astrophysics Data System (ADS)

    Zhang, Hong

    -6 month intervals thereafter. Local control rates were estimated according to WHO criteria. The evaluation included a physical examination (ultrasonography and CT, for some cases) and a complete blood count. Acute and late side effects were scored according to the Common Toxicity Criteria (CTC). Reactions occurring during RT or within the first 3 months after RT were scored as acute reactions. Results: 49 patients were followed-up (ranging from 1-13 months) and 2 were lost to follow-up. The tumors responded very well to the treatment in all patients. The tumor volumes started to regress during the RT or at the end of the RT, and up to 3-6 months, majority of tumors disappeared completely or almost. So far, no severe side-effects and no local recurrence within the treated volume have been observed. Conclusions: The data demonstrated that heavy ion radiotherapy for patients with shallow-seated tumors is clinical effective and safe, especially for patients with failures or recurrences of conventional therapies.

  4. Alkali - Aggregate reaction (AAR) A brief history of discovery of tis basic chemistry

    SciTech Connect

    Leps, T.M.

    1995-12-31

    Alkali Aggregate Reaction (AAR), also variously known as Alkali Silica Reaction (ASR) and even Alkali Carbonate Reaction (ACR), has troubled and challenged those of us since the 1930`s who would have liked to think of portland cement concrete and aggregates as a simple, reliable, inert, enduring construction material. Its complex and not easily understood chemistry successfully defied the understanding of the engineering fraternity for many decades. After all, civil engineers, architects, and construction engineers are not chemists or petrographers, and are only minimally laboratory-oriented or trained. Furthermore, the almost infinite variety of minerals which Nature has provided in the form of rocks and aggregates indeed constituted a nearly insurmountable challenge to the ready development of a credible understanding of the chemistry of expanding concrete. Accordingly, although a few talented pioneers such as E.A. Stephenson in 1916, J.C. Pearson & G.F. Loughlin in 1923, Professor R.J. Holden in 1935, and F. M. Lea & C.H. Desch in 1935, nibbled at the edges of understanding how gels were formed in the alkali-aggregate interaction process, it was not until 1940 when an engineer, Thomas E. Stanton, dared to publish a preliminary but understandable view of what causes portland cement concrete to expand. The writer`s interest in AAR began as far back as 1946 when the importance of the problem was repeatedly brought to his attention by Ralph W. Spencer, then Chief Civil Engineer of Southern California Edison Company, who was the writer`s supervisor in planning, designing and contracting the construction of many major projects, including dams. Previously as well as subsequently, the writer`s interest was enhanced by friendships and association with pioneers of AAR such as Professor Roy Carlson, Professor R.E. Davis, Lewis H. Tuthill, R.F. Blanks, and Roger Rhoades. The writer regrets never having met Thomas E. Stanton and his chief chemist, G.H.P.

  5. Biomedical research with heavy ions at the IMP accelerators

    NASA Astrophysics Data System (ADS)

    Li, Qiang

    The main ion-beam acceleration facilities and research activities at the Institute of Modern Physics (IMP), Chinese Academy of Sciences are briefly introduced. Some of the biomedical research with heavy ions such as heavy-ion biological effect, basic research related to heavy-ion cancer therapy and radiation breeding at the IMP accelerators are presented.

  6. The effects of lithium hydroxide solution on alkali silica reaction gels created with opal

    SciTech Connect

    Mitchell, Lyndon D.; Beaudoin, James J.; Grattan-Bellew, Patrick

    2004-04-01

    The reaction of Nevada opal with calcium hydroxide, potassium hydroxide and lithium hydroxide solutions was investigated. In addition, opal was exposed to a combined solution of these three hydroxides. The progress of the three reactions was followed using X-ray diffraction (XRD), {sup 29}Si nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The XRD results indicated the presence of a low-angle peak exclusive to the lithium-based reactions. The NMR results suggested a change in the silicate structure in the presence of lithium. These techniques indicated that the reaction of the alkali with the opal starting material is inhibited and perhaps stopped in the presence of lithium hydroxide. SEM revealed that the morphology of the reaction products on the surface of the reacted opal grains is markedly different invariably. It was concluded that evidence to support the theory of a protective layer exists and that the nature of the layer varies with ion type.

  7. Detection, monitoring and modelling of alkali-aggregate reaction in Kouga Dam (South Africa)

    SciTech Connect

    Elges, H.; Lecocq, P.; Oosthuizen, C.; Geertsema, A.

    1995-12-31

    Kouga Dam (formerly Paul Sauer Dam) is a double curvature arch dam completed in 1969. The aggregates and the cement used for the construction have subsequently been proven to be alkali reactive. The results of the monitoring programme and the alkali-aggregate reaction (AAR) tests as well as the methodology developed to standardise the logging of cores for these investigations are presented. A brief description of the Finite Element Model used to approximate the AAR process in order to determine positions for in-situ stress measurements is also given. The aim with these tests is to refine the model for prediction of the long-term behaviour of the dam and to make an assessment of the possibility of raising the dam.

  8. Chiral Magnetic Effect in Heavy Ion Collisions

    DOE PAGESBeta

    Liao, Jinfeng

    2016-12-01

    The Chiral Magnetic Effect (CME) is a remarkable phenomenon that stems from highly nontrivial interplay of QCD chiral symmetry, axial anomaly, and gluonic topology. We show it is of fundamental importance to search for the CME in experiments. The heavy ion collisions provide a unique environment where a hot chiral-symmetric quark-gluon plasma is created, gluonic topological fluctuations generate chirality imbalance, and very strong magnetic fields |Β→|~m2π are present during the early stage of such collisions. Significant efforts have been made to look for CME signals in heavy ion collision experiments. Lastly, in this contribution we give a brief overview onmore » the status of such efforts.« less

  9. Viscous photons in relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Dion, Maxime; Paquet, Jean-François; Schenke, Björn; Young, Clint; Jeon, Sangyong; Gale, Charles

    2011-12-01

    Theoretical studies of the production of real thermal photons in relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are performed. The space-time evolution of the colliding system is modelled using music, a 3+1D relativistic hydrodynamic simulation, using both its ideal and viscous versions. The inclusive spectrum and its azimuthal angular anisotropy are studied separately, and the relative contributions of the different photon sources are highlighted. It is shown that the photon v2 coefficient is especially sensitive to the details of the microscopic dynamics like the equation of state, the ratio of shear viscosity over entropy density, η/s, and to the morphology of the initial state.

  10. Heavy Ion Fragmentation Experiments at the Bevatron

    NASA Technical Reports Server (NTRS)

    Heckman, H. H.

    1975-01-01

    Fragmentation processes of heavy nuclei in matter using the heavy-ion capability of the Bevatron were studied. The purpose was to obtain the single particle inclusive spectra of secondary nuclei produced at 0 deg by the fragmentation of heavy ion beam projectiles. The process being examined is B+T yields F + anything, where B is the beam nucleus, T is the target nucleus, and F is the detected fragment. The fragments F are isotopically identified by experimental procedures involving magnetic analysis, energy loss and time-of-flight measurements. Attempts were also made to: (1) measure the total and partial production cross section for all isotopes, (2) test the applicability of high-energy multi-particle interaction theory to nuclear fragmentation, (3) apply the cross-section data and fragmentation probabilities to cosmic ray transport theory, and (4) search for systematic behavior of fragment production as a means to improve existing semi-empirical theories of cross sections.

  11. HEAVY-ION IMAGING APPLIED TO MEDICINE

    SciTech Connect

    Fabrikant, J.I.; Tobias, C.A.; Capp, M.P.; Benton, E.V.; Holley, W.R.

    1980-02-01

    Heavy particle radiography is a newly developed noninvasive low dose imaging procedure with increased resolution of minute density differences in soft tissues of the body. The method utilizes accelerated high energy ions, primarily carbon and neon, at the BEVALAC accelerator at the Lawrence Berkeley Laboratory. The research program applied to medicine utilizes heavy-ion radiography for low dose mammography, for treatment planning for cancer patients, and for imaging and accurate densitometry of skeletal structures and brain and spinal neoplasms. The presentation will be illustrated with clinical cases under study. Discussion will include the potential of heavy-ion imaging, and particularly reconstruction tomography, as an adjunct to existing diagnostic imaging procedures in medicine, both for the applications to the diagnosis, management and treatment of clinical cancer in man, but also for the early detection of small soft tissue tumors at low radiation dose.

  12. Experimental Verification of Heavy Ion Irradiation Simulation

    NASA Astrophysics Data System (ADS)

    Zhu, Shengyun; Iwata, T.; Xu, Yongjun; Zheng, Yongnan; Zhou, Dongmei; Zhu, Jiazheng; Wang, Zhiqqiang; Yuan, Daqing; Du, Enpeng; Zuo, Yi

    The heavy ion irradiation simulation of neutron and/or proton irradiation has been verified experimentally by the detailed study of radiation damage in α-Al2O3 irradiated at the equivalent dose by 5.28×1015 cm-285 MeV 19F ions and by 3×1020 cm-2 En≥1MeV neutrons, respectively. The radiation damage created by irradiation was examined by a positron annihilation lifetime technique. The positron annihilation parameters of lifetime and intensity obtained for both irradiations in α-Al2O3 are all in good agreement. This demonstrates that the heavy ion irradiation can well simulate the neutron and/or proton irradiation.

  13. Chamber propagation physics for heavy ion fusion

    SciTech Connect

    Callahan, D.A.

    1995-09-01

    Chamber transport is an important area of study for heavy ion fusion. Final focus and chamber-transport are high leverage areas providing opportunities to significantly decrease the cost of electricity from a heavy ion fusion power plant. Chamber transport in two basic regimes is under consideration. In the low chamber density regime ({approx_lt}0.003 torr), ballistic or nearly-ballistic transport is used. Partial beam neutralization has been studied to offset the effects of beam stripping. In the high chamber density regime ({approx_gt}.1 torr), two transport modes (pinched transport and channel transport) are under investigation. Both involve focusing the beam outside the chamber then transporting it at small radius ({approx} 2 mm). Both high chamber density modes relax the constraints on the beam quality needed from the accelerator which will reduce the driver cost and the cost of electricity.

  14. COMMISSIONING OF THE RELATIVISTIC HEAVY ION COLLIDER.

    SciTech Connect

    TRBOJEVIC,D.; AHRENS,L.; BLASKIEWICZ,M.; BRENNAN,M.; BAI,M.; CAMERON,P.; CARDONA,J.; CONNOLLY,R.; ET AL; TSOUPAS,N.; VAN ZEIJTS,J.

    2001-06-18

    This report describes in detail steps performed in bringing the Relativistic Heavy Ion Collider (RHIC) from the commissioning into the operational stage when collisions between 60 bunches of fully striped gold ions, were routinely provided. Corrections of the few power supplies connections by the beam measurements are described. Beam lifetime improvements at injection, along the acceleration are shown. The beam diagnostic results; like Schottky detector, beam profile monitor, beam position monitors, tune meter and others, are shown [1].

  15. Holifield Heavy Ion Research Facility: Users handbook

    SciTech Connect

    Auble, R.L.

    1987-01-01

    The primary objective of this handbook is to provide information for those who plan to carry out research programs at the Holifield Heavy Ion Research Facility (HHIRF) at Oak Ridge National Laboratory. The accelerator systems and experimental apparatus available are described. The mechanism for obtaining accelerator time and the responsibilities of those users who are granted accelerator time are described. The names and phone numbers of ORNL personnel to call for information about specific areas are given. (LEW)

  16. Heavy ion fusion 2 MV injector

    SciTech Connect

    Yu, S.; Eylon, S.; Henestroza, E.

    1995-04-01

    A heavy-ion-fusion driver-scale injector has been constructed and operated at Lawrence Berkeley Laboratory. The injector has produced 2.3 MV and 950 mA of K{sup +}, 15% above original design goals in energy and current. Normalized edge emittance of less than 1 {pi} mm-mr was measured over a broad range of parameters. The head-to-tail energy flatness is less than {+-} 0.2% over the 1 {micro}s pulse.

  17. Medium energy heavy ion operations at RHIC

    SciTech Connect

    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.

    2011-03-28

    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.

  18. Femtoscopy in Relativistic Heavy Ion Collisions

    SciTech Connect

    Lisa, M; Pratt, S; Soltz, R A; Wiedemann, U

    2005-07-29

    Analyses of two-particle correlations have provided the chief means for determining spatio-temporal characteristics of relativistic heavy ion collisions. We discuss the theoretical formalism behind these studies and the experimental methods used in carrying them out. Recent results from RHIC are put into context in a systematic review of correlation measurements performed over the past two decades. The current understanding of these results are discussed in terms of model comparisons and overall trends.

  19. Progress in Heavy Ion Fusion Research*

    NASA Astrophysics Data System (ADS)

    Celata, Christine

    2002-11-01

    The Heavy Ion Fusion program has recently transitioned from small scaled experiments to experiments with driver-scale currents at low energy. Two new experiments are in operation, the High Current Experiment (HCX), and the Neutralized Transport Experiment (NTX). The space charge in these experiments is similar to that of a driver, and enables investigation of the interaction of the beam with electrons, both those produced by beam halo scraping surfaces, and also electrons intentionally introduced to assist a neutralized focus. Other HIF-VNL experiments are being used to investigate a new approach to beam injectors. At the University of Maryland, an electron ring is being used to explore transport issues of interest. The design of all of these experiments, their goals, and recent experimental results and computer simulation, will be described. Future programmatic plans for Heavy Ion Fusion will also be discussed, including the scientific objectives and physics design of a proposed new next-step proof-of-principle experiment for Heavy Ion Fusion, the Integrated Beam Experiment (IBX). This experiment would constitute an integrated source-to-target test of beam dynamics using a driver-scale beam. Many beam manipulations, such as drift compression (integrated with final focus and subsequent neutralization), long-length-scale transport, longitudinal wave dynamics, and bending of space-charge-dominated beams would be tested at scale for the first time in this experiment. Finally, the programmatic importance, parameters, and scientific mission of a proof-of-performance experiment, the Integrated Research Experiment, will be discussed.

  20. Overview of US heavy ion fusion research

    SciTech Connect

    Logan, B.G.; Bieniosek, F.M.; Celata, C.M.; Henestroza, E.; Kwan,J.W.; Lee, E.P.; Leitner, M.; Roy, P.K.; Seidl, P.A.; Eylon, S.; Vay,J-L.; Waldron, W.L.; Yu, S.S.; Barnard, J.J.; Callahan, D.A.; Cohen,R.H.; Friedman, A.; Grote, D.P; Covo, Kireeff M.; Meier, W.R.; Molvik,A.W.; Lund, S.M.; Davidson, R.C.; Efthimion, P.C.; Gilson, E.P.; Grisham,L.R.; Kaganovich, I.D.; Qin, H.; Startsev, E.A.; Rose, D.V.; Welch, D.R.; Olson, C.L.; Kishek, R.A.; O'Shea, P.; Haber, I.; Prost, L.R.; Prost, L.

    2004-11-01

    Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, injectors, transport, final focusing, chambers and targets for high energy density physics (HEDP) and inertial fusion energy (IFE) driven by induction linac accelerators. One focus of present research is the beam physics associated with quadrupole focusing of intense, space-charge dominated heavy-ion beams, including gas and electron cloud effects at high currents, and the study of long-distance-propagation effects such as emittance growth due to field errors in scaled experiments. A second area of emphasis in present research is the introduction of background plasma to neutralize the space charge of intense heavy ion beams and assist in focusing the beams to a small spot size. In the near future, research will continue in the above areas, and a new area of emphasis will be to explore the physics of neutralized beam compression and focusing to high intensities required to heat targets to high energy density conditions as well as for inertial fusion energy.

  1. Ultra-Relativistic Heavy Ion Nuclear Physics

    SciTech Connect

    Braithwaite, W. J.

    1995-05-31

    This report describes an on-going research initiative for the University of Arkansas at Little Rock (UALR): investigating the physics of ultra-relativistic heavy ions, i.e. collisions between massive nuclei which have been accelerated to kinetic energies so large that the rest mass of the ions is a negligible fraction of their total mass-energy. This progress report is being submitted in conjunction with a 3-year grant-renewal proposal, containing additional materials. Three main categories drive the UALRGultra-relativistic heavy ion research. (1) investigations of multi-particle Hanbury-Brown-Twiss (HBT) correlations in the CERN and RHIC energy domains strongly influence the URHI experimental effort, (2) participation in the NA49 Experiment to study 33 TeV (160 GeV/nucleon) Pb on Pb collisions using the SPS facili& at CERN, and (3) participation in the STAR collaboration which is developing a major detector for use with the STAR Experiment at the Relativistic Heavy Ion Collider (RHIC), being built at BNL.

  2. Heavy ion driven LMF design concept. Revised

    SciTech Connect

    Lee, E.P.

    1995-07-01

    From 1988 to 1991, the US Department of Energy conducted a study of the requirements, designs and costs for a Laboratory Microfusion Facility (LMF). The primary purpose of the LMF would be testing of weapons physics and effects simulation using the output from microexplosions of inertial fusion targets. It does not need a high repetition rate, efficient driver system as required by an electrical generating plant; however there would be so many features in common that the design, construction and operation of an LMF would considerably advance the application of inertial confinement fusion to energy production. The DOE study concentrated particularly on the LMF driver, with design and component development undertaken at several national laboratories. Heavy Ions, although considered a possible LMF driver, did not receive attention until the final stages of this study since its program management was through the Office of Energy Research rather than Defense Programs. However, during preparation of the summary report for the study it was decided that an account of heavy ions was needed for a complete survey of the driver candidates. The conceptual heavy ion LMF driver design created for the DOE report did not receive the level of scrutiny of the other driver concepts and, unlike the others, no cost analysis by an independent contractor was performed.

  3. Overview of US heavy ion fusion research

    SciTech Connect

    Logan, B.G.; Bieniosek, F.M.; Celata, C.M.; Henestroza, E.; Kwan,J.W.; Lee, E.P.; Leitner, M.; Roy, P.K.; Seidl, P.A.; Eylon, S.; Vay,J-L.; Waldron, W.L.; Yu, S.S.; Barnard, J.J.; Callahan, D.A.; Cohen,R.H.; Friedman, A.; Grote, D.P.; Kireeff Covo, M.; Meier, W.R.; Molvik,A.W.; Lund, S.M.; Davidson, R.C.; Efthimion, P.C.; Gilson, E.P.; Grisham,L.R.; Kaganovich, I.D.; Qin, H.; Startsev, E.A.; Rose, D.V.; Welch, D.R.; Olson, C.L.; Kishek, R.A.; O'Shea, P.; Haber, I.; Prost, L.R.

    2005-06-23

    Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, injectors, transport, final focusing, chambers and targets for high energy density physics (HEDP) and inertial fusion energy (IFE) driven by induction linac accelerators. One focus of present research is the beam physics associated with quadrupole focusing of intense, space-charge dominated heavy-ion beams, including gas and electron cloud effects at high currents, and the study of long-distance-propagation effects such as emittance growth due to field errors in scaled experiments. A second area of emphasis in present research is the introduction of background plasma to neutralize the space charge of intense heavy ion beams and assist in focusing the beams to a small spot size. In the near future, research will continue in the above areas, and a new area of emphasis will be to explore the physics of neutralized beam compression and focusing to high intensities required to heat targets to high energy density conditions as well as for inertial fusion energy.

  4. Multiple Electron Stripping of Heavy Ion Beams

    SciTech Connect

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

    2002-06-25

    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.

  5. Biomolecular Emission by Swift Heavy Ion Bombardment

    SciTech Connect

    Wakamatsu, Yoshinobu; Yamada, Hideaki; Ninomiya, Satoshi; Matsuo, Jiro; Jones, Brian N.; Webb, Roger; Seki, Toshio; Aoki, Takaaki

    2011-01-07

    Secondary Ion Mass spectrometry (SIMS) has been generally used in the field of material sciences. In recent years, it has also been applied for molecular imaging of biological samples. Nevertheless, molecular ions derived from the large molecules (more than 1 kDa) were detected with very low sensitivity. Plasma desorption mass spectrometry (PDMS) is known as mass spectrometry for large organic molecule. In PDMS, fission fragments bombard samples and the impact induces molecular ionization by electronic excitation. Large organic molecules are detected by using swift heavy ions in SIMS. In this work, 6 MeV Cu{sup 4+} we irradiated angiotensin II, a class of peptides. The intact molecular ions generated by swift heavy ion irradiation were analyzed by time-of-flight (TOF) measurement. The yields are compared with some other probe ions, bismuth or flurane. Swift heavy ion bombardment ionized large organic molecules more effectively than other probes. Therefore, high energy ion can be applied in high resolution molecular imaging.

  6. Alkali-aggregate reaction under the influence of deicing salts in the Hokuriku district, Japan

    SciTech Connect

    Katayama, Tetsuya . E-mail: katayamat@kge.co.jp; Tagami, Masahiko; Sarai, Yoshinori; Izumi, Satoshi; Hira, Toshikatsu

    2004-11-15

    Concrete cores taken from highway bridges and culverts undergoing alkali-silica reaction (ASR) were investigated petrographically by means of core scanning, point counting, polarizing microscopy, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), electron-probe microanalysis with energy-dispersive spectrometry, in conjunction with wet chemical analyses and expansion tests. Field damage was roughly proportional to the content of andesite in the gravel aggregates due to the presence of highly reactive cristobalite and tridymite. Electron-probe microanalyzer analysis of unhydrated cement phases in the concrete revealed that the cement used had contained at least 0.5% to 1.0% alkali (Na{sub 2}Oeq) and that both the aggregates and the deicing salts had supplied part of the water-soluble alkali to concrete toward the threshold of producing ASR (Na{sub 2}O{sub eq} 3.0 kg/m{sup 3}). An accelerated concrete core expansion test (1 M NaOH, 80 deg. C) of the damaged structures mostly gave core expansions of >0.10% at 21 days (or >0.05% at 14 days), nearly comparable to those of a slow expansion test with saturated NaCl solution (50 deg. C, 91 days) which produced Cl-containing ASR gel.

  7. Harmonic well matter densities and Pauli correlation effects in heavy-ion collisions

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.

    1982-01-01

    A generalized optical model heavy ion reaction theory is extended to include correlation effects between projectile and target constituents according to the Pauli exclusion principle. These correlation effects are significant for accurately predicting cross sections for projectile nucleus abrasions, but are relatively unimportant for determining total and absorption cross sections for heavy ion collisions. For lighter nuclei, predictive capabilities were also improved by developing an analytic method for extracting their nuclear single particle density distributions from experimentally measured harmonic well charge density distributions. This improved theory is compared with previous theoretical predictions and recent experimental results.

  8. Two-particle interferometry for noncentral heavy-ion collisions

    SciTech Connect

    Wiedemann, U.A.

    1998-01-01

    In noncentral heavy-ion collisions, identical two-particle Hanbury-Brown{endash}Twiss (HBT) correlations C({bold K},{bold q}) depend on the azimuthal direction of the pair momentum {bold K}. We investigate the consequences for a harmonic analysis of the corresponding HBT radius parameters R{sub ij}{sup 2}. Our discussion includes both, a model-independent analysis of these parameters in the Gaussian approximation, and the study of a class of hydrodynamical models which mimic essential geometrical and dynamical properties of peripheral heavy-ion collisions. Also, we discuss the additional geometrical and dynamical information contained in the harmonic coefficients of R{sub ij}{sup 2}. The leading contribution of their first and second harmonics are found to satisfy simple constraints. This allows for a minimal, azimuthally sensitive parametrization of all first and second harmonic coefficients in terms of only two additional fit parameters. We determine to what extent these parameters can be extracted from experimental data despite finite multiplicity fluctuations and the resulting uncertainty in the reconstruction of the reaction plane. {copyright} {ital 1998} {ital The American Physical Society}

  9. Overview of Particle and Heavy Ion Transport Code System PHITS

    NASA Astrophysics Data System (ADS)

    Sato, Tatsuhiko; Niita, Koji; Matsuda, Norihiro; Hashimoto, Shintaro; Iwamoto, Yosuke; Furuta, Takuya; Noda, Shusaku; Ogawa, Tatsuhiko; Iwase, Hiroshi; Nakashima, Hiroshi; Fukahori, Tokio; Okumura, Keisuke; Kai, Tetsuya; Chiba, Satoshi; Sihver, Lembit

    2014-06-01

    A general purpose Monte Carlo Particle and Heavy Ion Transport code System, PHITS, is being developed through the collaboration of several institutes in Japan and Europe. The Japan Atomic Energy Agency is responsible for managing the entire project. PHITS can deal with the transport of nearly all particles, including neutrons, protons, heavy ions, photons, and electrons, over wide energy ranges using various nuclear reaction models and data libraries. It is written in Fortran language and can be executed on almost all computers. All components of PHITS such as its source, executable and data-library files are assembled in one package and then distributed to many countries via the Research organization for Information Science and Technology, the Data Bank of the Organization for Economic Co-operation and Development's Nuclear Energy Agency, and the Radiation Safety Information Computational Center. More than 1,000 researchers have been registered as PHITS users, and they apply the code to various research and development fields such as nuclear technology, accelerator design, medical physics, and cosmic-ray research. This paper briefly summarizes the physics models implemented in PHITS, and introduces some important functions useful for specific applications, such as an event generator mode and beam transport functions.

  10. Microscopic Theory of Heavy-Ion Interaction Potentials.

    NASA Astrophysics Data System (ADS)

    Katoot, Mohammad Walid

    Heavy-ion interaction potentials are calculated in a realistic, fully microscopic theory. The theory is based on the nonrelativistic quantum theory of many-body systems and is formulated in the language of second quantization; it utilizes a molecular set of basis states (two-center shell model) rather than selfconsistent wavefunctions. These basis states depend on two collective parameters: internuclear distance and fragment deformation. In constructing the ground state of the interacting many-body system, we assume, for simplicity, that the nucleons remain in the lowest possible molecular energy levels throughout the reaction. This adiabaticity assumption appears to be justified at bombarding energies near the Coulomb barrier. For computational reasons, the effective nucleon -nucleon interaction is described by a Skyrme force without spin-orbit coupling. The 5 parameters of the Skyrme interaction are fitted to measured binding energies. Heavy-ion interaction potentials are calculated for the following systems: ('28)Si + ('28)Si, ('40)Ca + ('40)Ca, ('90)Zr + ('90)Zr and ('238)U + ('238)U. At large internuclear distances, our theory approaches the double -folding model, which reproduces elastic and inelastic scattering data. However, at smaller distances, it is much more realistic than these phenomenological models, because (a) exchange energy and kinetic energy contributions are calculated consistently and (b) shell effects are taken into account. Possible improvements of the theory are discussed in the last chapter.

  11. Glenn T. Seaborg and heavy ion nuclear science

    SciTech Connect

    Loveland, W. . Dept. of Chemistry Lawrence Berkeley Lab., CA )

    1992-04-01

    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.

  12. Glenn T. Seaborg and heavy ion nuclear science

    SciTech Connect

    Loveland, W. |

    1992-04-01

    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.

  13. Glenn T. Seaborg and heavy ion nuclear science

    NASA Astrophysics Data System (ADS)

    Loveland, W.

    1992-04-01

    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. Studies of low energy deep inelastic reactions are discussed, and special emphasis is placed on charge equilibration. Additionally, studies of the properties of heavy residues in intermediate energy nuclear collisions and studies of target fragmentation in relativistic and ultrarelativistic reactions are reported. 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.

  14. Heavy-ion fission probability calculations at high excitation energy

    SciTech Connect

    D'Arrigo, A.; Giardina, G.; Taccone, A. Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Messina, Messina Istituto di Tecniche Spettroscopiche del Consiglio Nazionale delle Ricerche, Messina )

    1991-12-01

    In the framework of the statistical theory of nuclear reactions we calculated the fission probability {ital P}{sub {ital f}} of the {sup 153}Tb, {sup 158}Er, {sup 159}Dy, {sup 175}Hf, {sup 179}Ta, {sup 186}Os, and {sup 188}Os nuclei with a mass number {ital A}=150--200 produced by heavy-ion reactions. Starting from the spectra of the single-particle levels as determined by Nix and Moeller, and utilizing a formalism we developed, we determined the excitation energy dependence of the effective level density parameters for the fission and the neutron emission channels. The agreement between the fission probability calculations and the experimental data was reached when a nonadiabatic estimate of the collective effects was used to calculate the nuclear level density. In the fission process at high excitation energies induced by ions heavier than the {alpha} particle, an energy dependence of the effective fission barrier has to be used.

  15. Genetic effects on heavy ions in drosophila

    NASA Technical Reports Server (NTRS)

    Kale, P. G.

    1986-01-01

    Drosophila sex-linked recessive lethal mutation test was used to study the dose response relation and relative biological effectiveness of heavy ions. The experiments were performed using the heavy ion beams at BEVALAC of Lawrence Berkeley Laboratory. These experiments were undertaken according to the proposed milestones and included Ne-20, A-40 and Fe-65 ions with respective energies of 600 MeV, 840 MeV and 850 MeV. At these energies several doses of these radiations ranging from 20 to 1280 R were used. Space radiation exposure to astronauts is supposed to be quite low and therefore very low dose experiments i.e., 20 R, were also performed for the three ions. The mutation response was measured in all germ cell types i.e., spermatozoa, spermatids, spermatocytes and spermatogonia of treated Drosophila males. A linear dose frequency relation was observed for most of the range except at high doses where the saturation effect was observed. Also, a very significant difference was observed among the sensitivity of the four germ cell stages where spermatozoa and spermatids were more sensitive. At the higher doses of this range, most of the spermatogonia and spermatocytes were killed. Although comparative and identical experiments with X-rays or neutrons have not been performed, the compassion of our data with the ones available in literature suggest that the heavy ions have a high rbe and that they are several times more effective than low LET X-rays. The rbe compared to neutrons however appears to be only slightly higher.

  16. Progress in understanding heavy-ion stopping

    NASA Astrophysics Data System (ADS)

    Sigmund, P.; Schinner, A.

    2016-09-01

    We report some highlights of our work with heavy-ion stopping in the energy range where Bethe stopping theory breaks down. Main tools are our binary stopping theory (PASS code), the reciprocity principle, and Paul's data base. Comparisons are made between PASS and three alternative theoretical schemes (CasP, HISTOP and SLPA). In addition to equilibrium stopping we discuss frozen-charge stopping, deviations from linear velocity dependence below the Bragg peak, application of the reciprocity principle in low-velocity stopping, modeling of equilibrium charges, and the significance of the so-called effective charge.

  17. Modular TPC's for relativistic heavy ion experiments

    SciTech Connect

    Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Lindenbaum, S.J.

    1989-02-10

    We have developed a TPC system for use in relativistic heavy ion experiments that permits the efficient reconstruction of high multiplicity events including events with decay vertices. It operates with the beam through the middle of the chamber giving good efficiency, two-track separation and spatial resolution. The three-dimensional points in this system allow the reconstruction of the complex events of interest. The use of specially developed hybrid electronics allows us to build a compact and cost-effective system. 11 figs.

  18. Jet reconstruction in heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Cacciari, Matteo; Rojo, Juan; Salam, Gavin P.; Soyez, Gregory

    2011-01-01

    We examine the problem of jet reconstruction at heavy-ion colliders using jet-area-based background subtraction tools as provided by FastJet. We use Monte Carlo simulations with and without quenching to study the performance of several jet algorithms, including the option of filtering, under conditions corresponding to RHIC and LHC collisions. We find that most standard algorithms perform well, though the anti- k t and filtered Cambridge/Aachen algorithms have clear advantages in terms of the reconstructed p t offset and dispersion.

  19. Vorticity in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Deng, Wei-Tian; Huang, Xu-Guang

    2016-06-01

    We study the event-by-event generation of flow vorticity in the BNL Relativistic Heavy Ion Collider Au +Au collisions and CERN Large Hadron Collider Pb +Pb collisions by using the hijing model. Different definitions of the vorticity field and velocity field are considered. A variety of properties of the vorticity are explored, including the impact parameter dependence, the collision energy dependence, the spatial distribution, the event-by-event fluctuation of the magnitude and azimuthal direction, and the time evolution. In addition, the spatial distribution of the flow helicity is also studied.

  20. Non abelian hydrodynamics and heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Calzetta, E.

    2014-01-01

    The goal of the relativistic heavy ion collisions (RHIC) program is to create a state of matter where color degrees of freedom are deconfined. The dynamics of matter in this state, in spite of the complexities of quantum chromodynamics, is largely determined by the conservation laws of energy momentum and color currents. Therefore it is possible to describe its main features in hydrodynamic terms, the very short color neutralization time notwithstanding. In this lecture we shall give a simple derivation of the hydrodynamics of a color charged fluid, by generalizing the usual derivation of hydrodynamics from kinetic theory to the non abelian case.

  1. The heavy ions in space experiment

    NASA Technical Reports Server (NTRS)

    Adams, J. H., Jr.; Beahm, L. P.; Stiller, B.

    1985-01-01

    The Heavy Ions in Space (HIIS) experiment was developed and is currently in orbit onboard the long duration facility (LDEF). The HIIS will record relativistic cosmic ray nuclei heavier than magnesium and stopping nuclei down to helium. The experiment uses plastic track detectors that have a charge resolution of 0.15 charge units at krypton and 0.10 charge units, or better, for nuclei lighter than cobalt. The HIIS has a collecting power of 2 square meter steradians and it has already collected more than a year's data.

  2. Economic aspects of heavy ion fusion

    SciTech Connect

    Herrmannsfeldt, W.B.

    1984-01-01

    The usual parameter space for examining scenarios for heavy ion fusion power plants has generally been based on large, slow cycling, reactor chambers which are only marginally different from chambers proposed for laser drivers. This paper will examine the economic implications of assuming that an inexpensive, low gain pellet is available and that a suitable high-repetition rate reactor has been devised. Interesting scenarios are found that generate economically feasible power from a system with a minimum net capacity of approx. 1 GWe compared to the larger approx. 4 GWe required in previous studies.

  3. Faster Heavy Ion Transport for HZETRN

    NASA Technical Reports Server (NTRS)

    Slaba, Tony C.

    2013-01-01

    The deterministic particle transport code HZETRN was developed to enable fast and accurate space radiation transport through materials. As more complex transport solutions are implemented for neutrons, light ions (Z < 2), mesons, and leptons, it is important to maintain overall computational efficiency. In this work, the heavy ion (Z > 2) transport algorithm in HZETRN is reviewed, and a simple modification is shown to provide an approximate 5x decrease in execution time for galactic cosmic ray transport. Convergence tests and other comparisons are carried out to verify that numerical accuracy is maintained in the new algorithm.

  4. Non abelian hydrodynamics and heavy ion collisions

    SciTech Connect

    Calzetta, E.

    2014-01-14

    The goal of the relativistic heavy ion collisions (RHIC) program is to create a state of matter where color degrees of freedom are deconfined. The dynamics of matter in this state, in spite of the complexities of quantum chromodynamics, is largely determined by the conservation laws of energy momentum and color currents. Therefore it is possible to describe its main features in hydrodynamic terms, the very short color neutralization time notwithstanding. In this lecture we shall give a simple derivation of the hydrodynamics of a color charged fluid, by generalizing the usual derivation of hydrodynamics from kinetic theory to the non abelian case.

  5. High-energy accelerator for beams of heavy ions

    DOEpatents

    Martin, Ronald L.; Arnold, Richard C.

    1978-01-01

    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.

  6. A heavy ion spectrometer system for the measurement of projectile fragmentation of relativistic heavy ions

    SciTech Connect

    Engelage, J.; Crawford, H.J.; Greiner, L.; Kuo, C.

    1996-06-01

    The Heavy Ion Spectrometer System (HISS) at the LBL Bevalac provided a unique facility for measuring projectile fragmentation cross sections important in deconvolving the Galactic Cosmic Ray (GCR) source composition. The general characteristics of the apparatus specific to this application are described and the main features of the event reconstruction and analysis used in the TRANSPORT experiment are discussed.

  7. Local brain heavy ion irradiation induced Immunosuppression

    NASA Astrophysics Data System (ADS)

    Lei, Runhong; Deng, Yulin; Huiyang Zhu, Bitlife.; Zhao, Tuo; Wang, Hailong; Yu, Yingqi; Ma, Hong; Wang, Xiao; Zhuang, Fengyuan; Qing, Hong

    Purpose: To investigate the long term effect of acute local brain heavy ion irradiation on the peripheral immune system in rat model. Methodology: Only the brain of adult male Wistar rats were radiated by heavy ions at the dose of 15 Gy. One, two and three months after irradiation, thymus and spleen were analyzed by four ways. Tunel assay was performed to evaluate the percentage of apoptotic cells in thymus and spleen, level of Inflammatory cytokines (IL-2, IL-6, SSAO, and TNF-α) was detected by ELISA assay, the differentiation of thymus T lymphocyte subsets were measured by flow cytometry and the relative expression levels of genes related to thymus immune cell development were measured by using quantitative real-time PCR. Results: Thymus and spleen showed significant atrophy from one month to three months after irradiation. A high level of apoptosis in thymus and spleen were obtained and the latter was more vulnerable, also, high level of inflammatory cytokines were found. Genes (c-kit, Rag1, Rag2 and Sca1) related to thymus lymphocytes’ development were down-regulated. Conclusion: Local area radiation in the rat brain would cause the immunosuppression, especially, the losing of cell-mediated immune functions. In this model, radiation caused inflammation and then induced apoptosis of cells in the immune organs, which contributed to immunosuppression.

  8. The Relativistic Heavy Ion Collider at Brookhaven

    SciTech Connect

    Hahn, H.

    1988-01-01

    The conceptual design of a Relativistic Heavy Ion Collider (RACK) to be constructed in the existing 3.8 km tunnel at Brookhaven has been developed. The collider has been designed to provide collisions of gold ions at six intersection points with a luminosity of about 5 /times/ 10/sup 26/cm/sup /minus/2/sec/sup /minus/1/ at an energy of 100 GeV/u in each beam. Collisions with different ion species, including protons, will be possible. The collider consists of two interlaced, but otherwise separate, superconducting magnet rings. The 9.7 m long dipoles will operate at 3.5 T. Their 8 cm aperture was determined by the dimensions of gold ion beams taking into account diffusion due to intrabeam scattering. Heavy ion beams will be available from the Tandem Van de Graaff/Booster/AGS complex. The salient design features and the reasons for major design choices of the proposed machine are discussed in this paper. 24 refs., 7 figs., 2 tabs.

  9. Heavy ion irradiation of astrophysical ice analogs

    NASA Astrophysics Data System (ADS)

    Duarte, Eduardo Seperuelo; Domaracka, Alicja; Boduch, Philippe; Rothard, Hermann; Balanzat, Emmanuel; Dartois, Emmanuel; Pilling, Sergio; Farenzena, Lucio; da Silveira, Enio Frota

    Icy grain mantles consist of small molecules containing hydrogen, carbon, oxygen and nitrogen atoms (e.g. H2O, CO, CO2, NH3). Such ices, present in different astrophysical environments (giant planets satellites, comets, dense clouds, and protoplanetary disks), are subjected to irradiation of different energetic particles: UV radiation, ion bombardment (solar and stellar wind as well as galactic cosmic rays), and secondary electrons due to cosmic ray ionization of H2. The interaction of these particles with astrophysical ice analogs has been the object of research over the last decades. However, there is a lack of information on the effects induced by the heavy ion component of cosmic rays in the electronic energy loss regime. The aim of the present work is to simulate of the astrophysical environment where ice mantles are exposed to the heavy ion cosmic ray irradiation. Sample ice films at 13K were irradiated by nickel ions with energies in the 1-10 MeV/u range and analyzed by means of FTIR spectrometry. Nickel ions were used because their energy deposition is similar to that deposited by iron ions, which are particularly abundant cosmic rays amongst the heaviest ones. In this work the effects caused by nickel ions on condensed gases are studied (destruction and production of molecules as well as associated cross sections, sputtering yields) and compared with respective values for light ions and UV photons.

  10. Heavy ion fragmentation experiments at the bevatron

    NASA Technical Reports Server (NTRS)

    Heckman, H. H.

    1976-01-01

    Collaborative research efforts to study the fragmentation processes of heavy nuclei in matter using heavy ion beams of the Bevatron/Bevalac are described. The goal of the program is to obtain the single particle inclusive spectra of secondary nuclei produced at 0 deg by the fragmentation of heavy ion beam projectiles. The process being examined is B+T yields F + anything, where B is the beam nucleus, T is the target nucleus, and F is the detected fragment. The fragments F are isotopically identified by experimental procedures involving magnetic analysis, energy loss and time-of-flight measurements. Effects were also made to: (a) study processes of heavy nuclei in matter, (b) measure the total and partial production cross section for all isotopes, (c) test the applicability of high energy multiparticle interaction theory to nuclear fragmentation, (d) apply the cross section data and fragmentation probabilities to cosmic ray transport theory, and (e) search for systematic behavior of fragment production as a means to improve existing semi-empirical theories of cross-sections.

  11. Constraining relativistic models through heavy ion collisions

    SciTech Connect

    Menezes, D. P.; Providencia, C.; Chiapparini, M.; Bracco, M. E.; Delfino, A.; Malheiro, M.

    2007-12-15

    Relativistic models can be successfully applied to the description of compact star properties in nuclear astrophysics as well as to nuclear matter and finite nuclei properties, these studies taking place at low and moderate temperatures. Nevertheless, all results are model dependent, and so far it is unclear whether some of them should be discarded. Moreover, in the regime of hot hadronic matter, very few calculations exist using these relativistic models, in particular when applied to particle yields in heavy ion collisions. A very important investigation is the simulation of a supernova explosion that is based on the construction of an adequate equation of state that needs to be valid within very large ranges of temperatures (0 to 100 MeV at least) and densities (very low to ten times the nuclear saturation density at least). In the present work, we comment on the known constraints that can help the selection of adequate models in this wide regime and investigate the main differences that arise when the particle production during a Au+Au collision at the BNL Relativistic Heavy Ion Collider is calculated with different relativistic models. We conclude that most of the models investigated in the present work give a very good overall description of the data and make predictions for not yet measured particle ratios.

  12. Chamber transport for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Olson, Craig L.

    2014-01-01

    A brief review is given of research on chamber transport for HIF (heavy ion fusion) dating from the first HIF Workshop in 1976 to the present. Chamber transport modes are categorized into ballistic transport modes and channel-like modes. Four major HIF reactor studies are summarized (HIBALL-II, HYLIFE-II, Prometheus-H, OSIRIS), with emphasis on the chamber transport environment. In general, many beams are used to provide the required symmetry and to permit focusing to the required small spots. Target parameters are then discussed, with a summary of the individual heavy ion beam parameters required for HIF. The beam parameters are then classified as to their line charge density and perveance, with special emphasis on the perveance limits for radial space charge spreading, for the space charge limiting current, and for the magnetic (Alfven) limiting current. The major experiments on ballistic transport (SFFE, Sabre beamlets, GAMBLE II, NTX, NDCX) are summarized, with specific reference to the axial electron trapping limit for charge neutralization. The major experiments on channel-like transport (GAMBLE II channel, GAMBLE II self-pinch, LBNL channels, GSI channels) are discussed. The status of current research on HIF chamber transport is summarized, and the value of future NDCX-II transport experiments for the future of HIF is noted.

  13. Robust target implosion in heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Kawata, Shigeo; Iizuka, Yoshifumi; Kodera, Tomohiro; Ogoyski, Alexandar

    2008-11-01

    In heavy ion inertial fusion (HIF) a robust mode of target implosion is proposed to mitigate the beam illumination non-uniformity and the Rayleigh-Taylor (R-T) instability growth. In the HIF target implosion, key issues include uniformity of heavy ion beam (HIB) illumination, target implosion symmetry, compressed fuel ignition, reduction of the R-T instability growth, etc [1]. In the robust target in HIF, an oscillating implosion acceleration is employed to reduce the R-T instability growth, and a low-density foam layer is also inserted to enhance the radiation conversion efficiency from. The oscillating acceleration can be introduced by HIB axis oscillation, which can be easily realized in an actual accelerator final element. The oscillating acceleration introduces a new method of the R-T instability growth control. In the robust foam target, the radiation converted is confined and reduces the HIB illumination non-uniformity, though the HIBs illumination scheme is spherically symmetric and the target is also spherically symmetric. Therefore, the foam target irradiated by the oscillating HIBs can serve a robust direct-indirect hybrid mode of the symmetric target implosion in HIF. [1] Phys. of Plasmas, 12 (2005) 122702; NIMA, 577 (2007) 21.

  14. Induction accelerator development for heavy ion fusion

    SciTech Connect

    Reginato, L.L.

    1993-05-01

    For approximately a decade, the Heavy Ion Fusion Accelerator Research (HIFAR) group at LBL has been exploring the use of induction accelerators with multiple beams as the driver for inertial fusion targets. Scaled experiments have investigated the transport of space charge dominated beams (SBTE), and the current amplification and transverse emittance control in induction linacs (MBE-4) with very encouraging results. In order to study many of the beam manipulations required by a driver and to further develop economically competitive technology, a proposal has been made in partnership with LLNL to build a 10 MeV accelerator and to conduct a series of experiments collectively called the Induction Linac System Experiments (ILSE). The major components critical to the ILSE accelerator are currently under development. We have constructed a full scale induction module and we have tested a number of amorphous magnetic materials developed by Allied Signal to establish an overall optimal design. The electric and magnetic quadrupoles critical to the transport and focusing of heavy ion beams are also under development The hardware is intended to be economically competitive for a driver without sacrificing any of the physics or performance requirements. This paper will concentrate on the recent developments and tests of the major components required by the ILSE accelerator.

  15. Neutral cloud and heavy ion inner torus at Saturn

    SciTech Connect

    Johnson, R.E.; Pospieszalska, M.K.; Sittler, E.C. Jr.; Cheng, A.F.; Lanzerotti, L.J.

    1989-02-01

    Voyager plasma data are used in conjunction with laboratory data on water molecule sputter-yields and energy distributions to calculate the morphology of the Saturn neutral water molecule and dissociated water molecule-product torus coexisting with the E-ring and icy satellites of this planet. Plasma production rates determined for this cloud exhibit a structure with distance from Saturn as well as from the orbit plane; this suggests a lack of equilibrium for the heavy ion plasma at less than 7 planet radii. Attention is given to the possibility that the Saturn E-ring may be a precipitate of the neutral cloud that is initiated by low-energy ion-molecule reactions. 61 references.

  16. Multi Module Modeling of Ultra-Relativistic Heavy Ion Collisions.

    SciTech Connect

    Magas, V. K.; Csernai, L. P.; Keranen, A.; Manninen, J.; Strottman, D. D.

    2002-01-01

    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.

  17. Concrete modelling for expertise of structures affected by alkali aggregate reaction

    SciTech Connect

    Grimal, E.; Sellier, A.; Multon, S.; Le Pape, Y.; Bourdarot, E.

    2010-04-15

    Alkali aggregate reaction (AAR) affects numerous civil engineering structures and causes irreversible expansion and cracking. In order to control the safety level and the maintenance cost of its hydraulic dams, Electricite de France (EDF) must reach better comprehension and better prediction of the expansion phenomena. For this purpose, EDF has developed a numerical model based on the finite element method in order to assess the mechanical behaviour of damaged structures. The model takes the following phenomena into account: concrete creep, the stress induced by the formation of AAR gel and the mechanical damage. A rheological model was developed to assess the coupling between the different phenomena (creep, AAR and anisotropic damage). Experimental results were used to test the model. The results show the capability of the model to predict the experimental behaviour of beams subjected to AAR. In order to obtain such prediction, it is necessary to take all the phenomena occurring in the concrete into consideration.

  18. Microstructural Changes Due to Alkali-Silica Reaction during Standard Mortar Test

    DOE PAGESBeta

    Shin, Jun-Ho; Struble, Leslie; Kirkpatrick, R.

    2015-12-01

    The microstructural development of mortar bars with silica glass aggregate undergoing alkali-silica reaction (ASR) under the conditions of American Society for Testing and Materials (ASTM) Standard Test C1260 was analyzed using scanning electron microscopy and qualitative X-ray microanalysis. Cracking in the aggregate, the hydrated paste, and the paste-aggregate interface was important in the development of the microstructure. Cracks were characterized according to their location, their relationship to other cracks, and whether they are filled with ASR gel. Expansion of the bars was approximately 1% at 12 days and 2% at 53 days. They fell apart by 63 days. The barsmore » contained two zones, an inner region that was undergoing ASR and an outer and much more highly damaged zone that extended further inward over time. Evidence of ASR was present even during the period when specimens were immersed in water, prior to immersion in NaOH solution.« less

  19. Insights into alkali-silica reaction damage in mortar through acoustic nonlinearity

    NASA Astrophysics Data System (ADS)

    Rashidi, M.; Kim, J.-Y.; Jacobs, L. J.; Kurtis, K. E.

    2016-02-01

    The progression of damage as a result of alkali-silica reaction in mortar samples is monitored by using the Nonlinear Impact Resonance Acoustic Spectroscopy (NIRAS) method and expansion measurements, which were performed daily. Results of this study show a strong correlation between the cumulative average nonlinearity parameter and expansion for each sample type, and a strong linear relationship between fourteen-day expansion and the cumulative average nonlinearity of among sample types. In addition to the cumulative average nonlinearity parameter, the standard deviation of average nonlinearity parameter shows strong correlation with the fourteen-day expansion of sample types. Results provide insights to the relationship with the acoustic nonlinearity and damage caused by the ASR.

  20. Microstructural Changes Due to Alkali-Silica Reaction during Standard Mortar Test

    SciTech Connect

    Shin, Jun-Ho; Struble, Leslie; Kirkpatrick, R.

    2015-12-01

    The microstructural development of mortar bars with silica glass aggregate undergoing alkali-silica reaction (ASR) under the conditions of American Society for Testing and Materials (ASTM) Standard Test C1260 was analyzed using scanning electron microscopy and qualitative X-ray microanalysis. Cracking in the aggregate, the hydrated paste, and the paste-aggregate interface was important in the development of the microstructure. Cracks were characterized according to their location, their relationship to other cracks, and whether they are filled with ASR gel. Expansion of the bars was approximately 1% at 12 days and 2% at 53 days. They fell apart by 63 days. The bars contained two zones, an inner region that was undergoing ASR and an outer and much more highly damaged zone that extended further inward over time. Evidence of ASR was present even during the period when specimens were immersed in water, prior to immersion in NaOH solution.

  1. Microwave material characterization of alkali-silica reaction (ASR) gel in cementitious materials

    NASA Astrophysics Data System (ADS)

    Hashemi, Ashkan

    Since alkali-silica reaction (ASR) was recognized as a durability challenge in cement-based materials over 70 years ago, numerous methods have been utilized to prevent, detect, and mitigate this issue. However, quantifying the amount of produced ASR byproducts (i.e., ASR gel) in-service is still of great interest in the infrastructure industry. The overarching objective of this dissertation is to bring a new understanding to the fundamentals of ASR formation from a microwave dielectric property characterization point-of-view, and more importantly, to investigate the potential for devising a microwave nondestructive testing approach for ASR gel detection and evaluation. To this end, a comprehensive dielectric mixing model was developed with the potential for predicting the effective dielectric constant of mortar samples with and without the presence of ASR gel. To provide pertinent inputs to the model, critical factors on the influence of ASR gel formation on dielectric and reflection properties of several mortar samples were investigated at R, S, and X-band. Effects of humidity, alkali content, and long-term curing conditions on ASR-prone mortars were also investigated. Additionally, dielectric properties of chemically different synthetic ASR gel were also determined. All of these, collectively, served as critical inputs to the mixing model. The resulting developed dielectric mixing model has the potential to be further utilized to quantify the amount of produced ASR gel in cement-based materials. This methodology, once becomes more mature, will bring new insight to the ASR reaction, allowing for advancements in design, detection and mitigation of ASR, and eventually has the potential to become a method-of-choice for in-situ infrastructure health-monitoring of existing structures.

  2. Heavy Ion Accelerator-Driven Inertial Fusion

    NASA Astrophysics Data System (ADS)

    Hofmann, Ingo

    The idea of using accelerators in the production of energy by inertial confinement fusion has been developed since the mid-1970s. The basic concept is to use accelerated beams of heavy ions to provide energy to implode and ignite a small fusion pellet. Accelerators have been seen as attractive for this application due to their reliability, high repetition rate, and potential efficiency. They are therefore competitive with high power lasers at least for the commercial production of electrical power. This review summarizes part of the development and scientific efforts directed toward this application, which has been realized over time to be an extremely demanding one. Here we focus primarily on the rf linac/storage ring driver system approach and summarize the specific development that culminated in the European HIDIF study of the late 1990s. We also discuss some of the relevant followup accelerator studies.

  3. Mutagenic effects of heavy ions in bacteria

    NASA Astrophysics Data System (ADS)

    Horneck, G.; Krasavin, E. A.; Kozubek, S.

    1994-10-01

    Various mutagenic effects by heavy ions were studied in bacteria, irradiated at accelerators in Dubna, Prague, Berkeley or Darmstadt. Endpoints investigated are histidine reversion (B. subtilis, S. typhimurium), azide resistance (B. subtilis), mutation in the lactose operon (E. coli), SOS chromotest (E. coli) and λ-prophage induction (E. coli). It was found that the cross sections of the different endpoints show a similar dependence on energy. For light ions (Z <= 4) the cross section decreases with increasing energy. For ions of Z = 10, it is nearly independent of energy. For heavier ions (Z >= 26) it increases with energy up to a maximum or saturation. The increment becomes steeper with increasing Z. This dependence on energy suggests a ``mutagenic belt'' inside the track that is restricted to an area where the density of departed energy is low enough not to kill the cell, but high enough to induce mutations.

  4. Nuclei at HERA and heavy ion physics

    SciTech Connect

    Gavin, S.; Strikman, M.

    1995-12-31

    Copies of 16 viewgraph sets from a workshop held at Brookhaven National Laboratory, 17-18 November, 1995. Titles of talks: HERA: The Present; HERA: Potential with Nuclei; Review of Hadron-Lepton Nucleus Data; Fermilab E665: results in muon scattering; Interactions of Quarks and Gluons with Nuclear Matter; Rescattering in Nuclear Targets for Photoproduction and DIS; Structure Functions and Nuclear Effect at PHENIX; Probing Spin-Averaged and Spin-Dependent Parton Distributions Using the Solenoidal Tracker at RHIC (STAR); Jet Quenching in eA, pA, AA; Nuclear Gluon Shadowing via Continuum Lepton Pairs; What can we learn from HERA with a colliding heavy ion beam? The limiting curve of leading particles at infinite A; Coherent Production of Vector Mesons off Light Nuclei in DIS; A Model of High Parton Densities in PQCD; Gluon Production for Weizaecker-Williams Field in Nucleus-Nucleus Collisions; Summary Talk.

  5. Identifying Multiquark Hadrons from Heavy Ion Collisions

    SciTech Connect

    Cho, Sungtae; Furumoto, Takenori; Yazaki, Koichi; Hyodo, Tetsuo; Jido, Daisuke; Ohnishi, Akira; Ko, Che Ming; Lee, Su Houng; Nielsen, Marina; Sekihara, Takayasu; Yasui, Shigehiro

    2011-05-27

    Identifying hadronic molecular states and/or hadrons with multiquark components either with or without exotic quantum numbers is a long-standing challenge in hadronic physics. We suggest that studying the production of these hadrons in relativistic heavy ion collisions offers a promising resolution to this problem as yields of exotic hadrons are expected to be strongly affected by their structures. Using the coalescence model for hadron production, we find that, compared to the case of a nonexotic hadron with normal quark numbers, the yield of an exotic hadron is typically an order of magnitude smaller when it is a compact multiquark state and a factor of 2 or more larger when it is a loosely bound hadronic molecule. We further find that some of the newly proposed heavy exotic states could be produced and realistically measured in these experiments.

  6. Latchup in CMOS devices from heavy ions

    NASA Technical Reports Server (NTRS)

    Soliman, K.; Nichols, D. K.

    1983-01-01

    It is noted that complementary metal oxide semiconductor (CMOS) microcircuits are inherently latchup prone. The four-layer n-p-n-p structures formed from the parasitic pnp and npn transistors make up a silicon controlled rectifier. If properly biased, this rectifier may be triggered 'ON' by electrical transients, ionizing radiation, or a single heavy ion. This latchup phenomenon might lead to a loss of functionality or device burnout. Results are presented from tests on 19 different device types from six manufacturers which investigate their latchup sensitivity with argon and krypton beams. The parasitic npnp paths are identified in general, and a qualitative rationale is given for latchup susceptibility, along with a latchup cross section for each type of device. Also presented is the correlation between bit-flip sensitivity and latchup susceptibility.

  7. Jet Structure in Heavy Ion Collisions

    NASA Astrophysics Data System (ADS)

    Blaizot, J.-P.; Mehtar-Tani, Y.

    We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark-gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter hat q. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the incone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.

  8. Jet structure in heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Blaizot, J.-P.; Mehtar-Tani, Y.

    2015-10-01

    We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark-gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter q̂. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the in-cone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.

  9. Focal-surface detector for heavy ions

    DOEpatents

    Erskine, John R.; Braid, Thomas H.; Stoltzfus, Joseph C.

    1979-01-01

    A detector of the properties of individual charged particles in a beam includes a gridded ionization chamber, a cathode, a plurality of resistive-wire proportional counters, a plurality of anode sections, and means for controlling the composition and pressure of gas in the chamber. Signals generated in response to the passage of charged particles can be processed to identify the energy of the particles, their loss of energy per unit distance in an absorber, and their angle of incidence. In conjunction with a magnetic spectrograph, the signals can be used to identify particles and their state of charge. The detector is especially useful for analyzing beams of heavy ions, defined as ions of atomic mass greater than 10 atomic mass units.

  10. HEAVY ION PHYSICS WITH THE ATLAS DETECTOR.

    SciTech Connect

    WHITE, S.

    2005-02-05

    Soon after the LHC is commissioned with proton beams the ATLAS experiment will begin studies of Pb-Pb collisions with a center of mass energy of {radical}s{sub NN} = 5.5 TeV. The ATLAS program is a natural extension of measurements at RHIC in a direction that exploits the higher LHC energies and the superb ATLAS calorimeter and tracking coverage. At LHC energies, collisions will be produced with even higher energy density than observed at RHIC. The properties of the resulting hot medium can be studied with higher energy probes, which are more directly interpreted through modification of jet properties emerging from these collisions, for example. Other topics which are enabled by the 30-fold increase in center of mass energy include probing the partonic structure of nuclei with hard photoproduction (in UltraPeripheral collisions) and in p-Pb collisions. Here we report on evaluation of ATLAS capabilities for Heavy Ion Physics.

  11. Rapidity dependence in holographic heavy ion collisions

    DOE PAGESBeta

    Wilke van der Schee; Schenke, Bjorn

    2015-12-11

    We present an attempt to closely mimic the initial stage of heavy ion collisions within holography, assuming a decoupling of longitudinal and transverse dynamics in the very early stage. We subsequently evolve the obtained initial state using state-of-the-art hydrodynamic simulations and compare results with experimental data. We present results for charged hadron pseudorapidity spectra and directed and elliptic flow as functions of pseudorapidity for √sNN = 200GeV Au-Au and 2.76TeV Pb-Pb collisions. As a result, the directed flow interestingly turns out to be quite sensitive to the viscosity. The results can explain qualitative features of the collisions, but the rapiditymore » spectra in our current model is narrower than the experimental data.« less

  12. Rapidity dependence in holographic heavy ion collisions

    SciTech Connect

    Wilke van der Schee; Schenke, Bjorn

    2015-12-11

    We present an attempt to closely mimic the initial stage of heavy ion collisions within holography, assuming a decoupling of longitudinal and transverse dynamics in the very early stage. We subsequently evolve the obtained initial state using state-of-the-art hydrodynamic simulations and compare results with experimental data. We present results for charged hadron pseudorapidity spectra and directed and elliptic flow as functions of pseudorapidity for √sNN = 200GeV Au-Au and 2.76TeV Pb-Pb collisions. As a result, the directed flow interestingly turns out to be quite sensitive to the viscosity. The results can explain qualitative features of the collisions, but the rapidity spectra in our current model is narrower than the experimental data.

  13. Superconducting heavy-ion linac at Argonne

    SciTech Connect

    Aron, J.; Benaroya, R.; Bollinger, L.M.; Clifft, B.G.; Johnson, K.W.; Nixon, J.M.; Markovich, P.; Pardo, R.C.; Shepard, K.W.

    1981-01-01

    The design, status, and performance of the first operating superconducting heavy-ion accelerator, a linac used to boost the energies of beams from a 9-MV tandem, is summarized. When completed in 1981, the linac will consist of 24 independently-phased split-ring niobium resonators operating at 97 MHz. This linac is designed to provide 29 MV of acceleration. Because of the modular character of the system, the linac has been operable and useful since mid-1978, when a beam was accelerated through 2 units and the first nuclear-physics experiments were preformed. Now, 16 resonators are in use, and a beam has been accelerated for approx. 6000 h. Resonator performance has been remarkably stable, in spite of vacuum accidents, and the linac as a whole operates reliably without operators in attendance during nights and weekends. The ease and speed with which the beam energy can be changed is proving to be unexpectedly valuable to users.

  14. Bremsstrahlung from relativistic heavy ions in matter

    SciTech Connect

    Soerensen, Allan H.

    2010-02-15

    The emission of electromagnetic radiation by relativistic bare heavy ions penetrating ordinary matter is investigated. Our main aim is to determine the bremsstrahlung which we define as the radiation emitted when the projectile does not break up. It pertains to collisions without nuclear contact ('ultraperipheral collisions'). Requirement of coherent action of the nucleons in order to keep the penetrating projectile intact limits bremsstrahlung to relatively soft photons. The spectrum shows a resonance structure with peak position near 2{gamma} times the position of the giant dipole resonance, that is, near 25{gamma} MeV for a lead ion ({gamma}{identical_to}E/Mc{sup 2} is the Lorentz factor of the projectile of energy E and mass M). The maximum exceeds the bremsstrahlung from a hypothetical structureless, pointlike particle of the same charge and mass as the incoming nucleus, but rapid depletion follows on the high-energy side of the peak. As a result of its relative softness, bremsstrahlung never dominates the energy-loss process for heavy ions. As to the emission of electromagnetic radiation in collisions with nuclear break-up, it appears modest when pertaining to incoherent action of the projectile nucleons in noncontact collisions. In collisions with nuclear contact, though, substantial radiation is emitted. It overshoots the bremsstrahlung. However, despite the violence of contact events, the associated photon emission only exceeds the radiation from a hypothetical structureless pointlike nucleus [emitted energy per unit photon-energy interval essentially constant up to ({gamma}-1)Mc{sup 2}] at relatively low photon energies (for lead roughly below 0.2{gamma} GeV, a limit which is about an order of magnitude above the position of the bremsstrahlung peak). Results are presented for bare lead ions penetrating a solid lead target at energies of 158 GeV/n ({gamma}=170) and beyond.

  15. Bremsstrahlung from relativistic heavy ions in matter

    NASA Astrophysics Data System (ADS)

    Sørensen, Allan H.

    2010-02-01

    The emission of electromagnetic radiation by relativistic bare heavy ions penetrating ordinary matter is investigated. Our main aim is to determine the bremsstrahlung which we define as the radiation emitted when the projectile does not break up. It pertains to collisions without nuclear contact (“ultraperipheral collisions”). Requirement of coherent action of the nucleons in order to keep the penetrating projectile intact limits bremsstrahlung to relatively soft photons. The spectrum shows a resonance structure with peak position near 2γ times the position of the giant dipole resonance, that is, near 25γ MeV for a lead ion (γ≡E/Mc2 is the Lorentz factor of the projectile of energy E and mass M). The maximum exceeds the bremsstrahlung from a hypothetical structureless, pointlike particle of the same charge and mass as the incoming nucleus, but rapid depletion follows on the high-energy side of the peak. As a result of its relative softness, bremsstrahlung never dominates the energy-loss process for heavy ions. As to the emission of electromagnetic radiation in collisions with nuclear break-up, it appears modest when pertaining to incoherent action of the projectile nucleons in noncontact collisions. In collisions with nuclear contact, though, substantial radiation is emitted. It overshoots the bremsstrahlung. However, despite the violence of contact events, the associated photon emission only exceeds the radiation from a hypothetical structureless pointlike nucleus [emitted energy per unit photon-energy interval essentially constant up to (γ-1)Mc2] at relatively low photon energies (for lead roughly below 0.2γ GeV, a limit which is about an order of magnitude above the position of the bremsstrahlung peak). Results are presented for bare lead ions penetrating a solid lead target at energies of 158 GeV/n (γ=170) and beyond.

  16. Chromosomal instability induced by heavy ion irradiation

    NASA Technical Reports Server (NTRS)

    Limoli, C. L.; Ponnaiya, B.; Corcoran, J. J.; Giedzinski, E.; Morgan, W. F.

    2000-01-01

    PURPOSE: To establish the dose-response relationship for the induction of chromosomal instability in GM10115 cells exposed to high-energy iron ions (1 GeV/nucleon, mean LET 146 keV/microm) and gold ions (11 GeV/nucleon, mean LET 1450 keV/microm). Past work has established that sparsely ionizing X-rays can induce a long-lived destabilization of chromosomes in a dose-dependent manner at an incidence of approximately 3% per gray. The present investigation assesses the capacity of High-Z and High-energy (HZE) particles to elicit this same endpoint. MATERIALS AND METHODS: Clonal populations derived from single progenitor cells surviving heavy-ion irradiation were analyzed cytogenetically to identify those clones showing a persistent destablization of chromosomes. RESULTS: Dose-response data, with a particular emphasis at low dose (< 1.0 Gy), indicate a frequency of approximately 4% per gray for the induction of chromosomal instability in clones derived from single progenitor cells surviving exposure to iron ions. The induction of chromosomal instability by gold ions was, however, less responsive to applied dose, as the observed incidence of this phenotype varied from 0 to 10% over 1-8 Gy. Both iron and gold ions gave dose-dependent increases in the yield of chromosomal aberrations (both chromosome- and chromatid-type) measured at the first mitosis following irradiation, as well as shoulderless survival curves having D0=0.87 and 1.1 Gy respectively. CONCLUSIONS: Based on the present dose-response data, the relative biological effectiveness of iron ions is 1.3 for the induction of chromosomal instability, and this indicates that heavy ions are only slightly more efficient than X-rays at eliciting this delayed phenotype.

  17. Theoretical Concepts for Ultra-Relativistic Heavy Ion Collisions

    SciTech Connect

    McLerran,L.

    2009-07-27

    Various forms of matter may be produced in ultra-relativistic heavy ion collisions. These are the Quark GluonPlasma, the Color Glass Condensate , the Glasma and Quarkyoninc Matter. A novel effect that may beassociated with topological charge fluctuations is the Chiral Magnetic Effect. I explain these concepts andexplain how they may be seen in ultra-relatvistic heavy ion collisions

  18. Bose condensation of nuclei in heavy ion collisions.

    PubMed

    Tripathi, R K; Townsend, L W

    1994-07-01

    Using a fully self-consistent quantum statistical model, we demonstrate the possibility of Bose condensation of nuclei in heavy ion collisions. The most favorable conditions of high densities and low temperatures are usually associated with astrophysical processes and may be difficult to achieve in heavy ion collisions. Nonetheless, some suggestions for the possible experimental verification of the existence of this phenomenon are made.

  19. Bose condensation of nuclei in heavy ion collisions

    NASA Technical Reports Server (NTRS)

    Tripathi, Ram K.; Townsend, Lawrence W.

    1994-01-01

    Using a fully self-consistent quantum statistical model, we demonstrate the possibility of Bose condensation of nuclei in heavy ion collisions. The most favorable conditions of high densities and low temperatures are usually associated with astrophysical processes and may be difficult to achieve in heavy ion collisions. Nonetheless, some suggestions for the possible experimental verification of the existence of this phenomenon are made.

  20. Monte-Carlo Simulations of Heavy Ions Track Structures and Applications

    NASA Technical Reports Server (NTRS)

    Plante, Ianik; Cucinotta, Francia A.

    2013-01-01

    In space, astronauts are exposed to protons, high ]energy heavy (HZE) ions that have a high charge (Z) and energy (E), and secondary radiation, including neutrons and recoil nuclei produced by nuclear reactions in spacecraft walls or in tissue. The astronauts can only be partly shielded from these particles. Therefore, on travelling to Mars, it is estimated that every cell nucleus in an astronaut fs body would be hit by a proton or secondary electron (e.g., electrons of the target atoms ionized by the HZE ion) every few days and by an HZE ion about once a month. The risks related to these heavy ions are not well known and of concern for long duration space exploration missions. Medical ion therapy is another situation where human beings can be irradiated by heavy ions, usually to treat cancer. Heavy ions have a peculiar track structure characterized by high levels of energy ]deposition clustering, especially in near the track ends in the so ]called eBragg peak f region. In radiotherapy, these features of heavy ions can provide an improved dose conformation with respect to photons, also considering that the relative biological effectiveness (RBE) of therapeutic ions in the plateau region before the peak is sufficiently low. Therefore, several proton and carbon ion therapy facilities are under construction at this moment

  1. Development of a Position Sensitive Heavy Ion Detector for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Need, Emily; Blackmon, J. C.; Deibel, C. M.; Lai, J.; Lindhart, L. E.; Macon, K. T.; Matos, M.; Rasco, B. C.; Rogachev, G.; Wiedenhover, I.

    2012-10-01

    The Array for Nuclear Astrophysics Studies with Exotic Nuclei (ANASEN) is a charged-particle detector array used to study reactions with radioactive beams at FSU and the NSCL. One of the main goals is to improve our understanding of nuclear reactions important in stellar explosions. One important component of ANASEN is a heavy ion detector located downstream of the target that is used to identify the atomic number of heavy ions based upon their energy loss through the gas-filled chamber. We have developed a new version of this detector with major design changes to improve data collection and allow much greater selectivity for the reactions of interest. These changes include anodes based on custom printed circuit boards that provide position sensitivity, larger grids to provide greater acceptance, and a change in wire spacing on the grids to improve transmission. We will present the new design and results from initial tests.

  2. Monitoring, Modeling, and Diagnosis of Alkali-Silica Reaction in Small Concrete Samples

    SciTech Connect

    Agarwal, Vivek; Cai, Guowei; Gribok, Andrei V.; Mahadevan, Sankaran

    2015-09-01

    Assessment and management of aging concrete structures in nuclear power plants require a more systematic approach than simple reliance on existing code margins of safety. Structural health monitoring of concrete structures aims to understand the current health condition of a structure based on heterogeneous measurements to produce high-confidence actionable information regarding structural integrity that supports operational and maintenance decisions. This report describes alkali-silica reaction (ASR) degradation mechanisms and factors influencing the ASR. A fully coupled thermo-hydro-mechanical-chemical model developed by Saouma and Perotti by taking into consideration the effects of stress on the reaction kinetics and anisotropic volumetric expansion is presented in this report. This model is implemented in the GRIZZLY code based on the Multiphysics Object Oriented Simulation Environment. The implemented model in the GRIZZLY code is randomly used to initiate ASR in a 2D and 3D lattice to study the percolation aspects of concrete. The percolation aspects help determine the transport properties of the material and therefore the durability and service life of concrete. This report summarizes the effort to develop small-size concrete samples with embedded glass to mimic ASR. The concrete samples were treated in water and sodium hydroxide solution at elevated temperature to study how ingress of sodium ions and hydroxide ions at elevated temperature impacts concrete samples embedded with glass. Thermal camera was used to monitor the changes in the concrete sample and results are summarized.

  3. Reactions of HCl and D2O with molten alkali carbonates.

    PubMed

    Krebs, Thomas; Nathanson, Gilbert M

    2011-02-01

    The acidic oxide SO₂ and protic acid HCl are among the gases released in the combustion of coal and the incineration of municipal waste. They are typically removed by wet or dry scrubbing involving calcium carbonate or calcium hydroxide. The molten alkali carbonate eutectic provides a liquid-state alternative that readily absorbs SO₂ and HCl and does not become covered with a passivating layer. Gas-liquid scattering experiments utilizing the eutectic mixture (44 mol % Li₂CO₃, 31 mol % Na₂CO₃, 25 mol % K₂CO₃) reveal that the reaction probability for HCl(g) + CO₃²⁻ → CO₂(g) + OH⁻ + Cl⁻ is 0.31 ± 0.02 at 683 K and rises to 0.39 at 783 K. Gaseous CO₂ is formed within 10⁻⁴ s or less, implying that the reaction takes place in a liquid depth of less than 1000 Å. When the melt is exposed to D₂O, the analogous reaction D₂O(g) + CO₃²⁻ → CO₂(g) + 2OD⁻ occurs too slowly to measure and no water uptake is observed. Together with previous studies of SO₂(g) + CO₃²⁻ → CO₂(g) + SO₃²⁻, these results demonstrate that molten carbonates efficiently remove both gaseous HCl and SO₂ while reacting at most weakly with water vapor. The experiments further highlight the remarkable ability of hot CO₃²⁻ ions to behave as a base in reactions with protic and Lewis acids.

  4. Effect of entrance channel on dynamics of heavy ions collision

    NASA Astrophysics Data System (ADS)

    Naderi, D.

    2016-01-01

    A combined dynamical model using concept of dinuclear systems (DNS) and one-dimensional (1D) Langevin equations was applied to investigate the effect of entrance channel on dynamics of heavy ions collision. The 30Si+170Er, 16O+184W and 19F+181Ta reactions which formed the compound nucleus 200Pb have been considered to study this effect. We studied these reactions dynamically and calculated the ratio of evaporation residue cross-section to fusion cross-section (σER/σFus) as a tool for investigation of entrance channel effect. Results of combined model are compared with available experimental data and results of 1D Langevin equations. Obtained results based on combined model are in better agreement with experimental data in comparison with results of Langevin equations. We concluded for 30Si+170Er and 19F+181Ta reactions the results of combined model that support the quasi-fission process are different relative to Langevin dynamical approach, whereas for 16O+184W system the two models give similar results.

  5. Model for Cumulative Solar Heavy Ion Energy and LET Spectra

    NASA Technical Reports Server (NTRS)

    Xapsos, Mike; Barth, Janet; Stauffer, Craig; Jordan, Tom; Mewaldt, Richard

    2007-01-01

    A probabilistic model of cumulative solar heavy ion energy and lineary energy transfer (LET) spectra is developed for spacecraft design applications. Spectra are given as a function of confidence level, mission time period during solar maximum and shielding thickness. It is shown that long-term solar heavy ion fluxes exceed galactic cosmic ray fluxes during solar maximum for shielding levels of interest. Cumulative solar heavy ion fluences should therefore be accounted for in single event effects rate calculations and in the planning of space missions.

  6. Heavy ion fusion experiments at LBNL and LLNL

    SciTech Connect

    Ahle, L

    1998-08-19

    The long-range goal of the US Heavy Ion Fusion (HIF) program is to develop heavy ion accelerators capable of igniting inertial fusion targets to generate fusion energy for electrical power production. Accelerators for heavy ion fusion consist of several subsystems: ion sources, injectors, matching sections, combiners, induction acceleration sections with electric and magnetic focusing, beam compression and bending sections, and a final-focus system to focus the beams onto the target. We are currently assembling or performing experiments to address the physics of all these subsystems. This paper will discuss some of these experiments.

  7. Swift heavy ion irradiation of polystyrene

    NASA Astrophysics Data System (ADS)

    Balanzat, E.; Bouffard, S.; Bousquerel, A.; Devy, J.; Gaté, Chr.

    1996-08-01

    We have studied by Fourier transform infrared spectroscopy the chemical modifications induced by swift heavy ions in polystyrene. The overall destruction yield becomes very significant at high electronic stopping power ( {dE }/{dx }) e and the radiation sensitivity of this aromatic polymer merges typical values of equivalent aliphatic polymers as polyethylene. So, the radiation resistance conferred, at low ( {dE }/{dx }) e, to polystyrene by the phenyl side group is lost at high ( {dE }/{dx }) e. The creation of different unsaturated groups is also observed. They correspond to the vibration frequencies of alkyne, allene, vinylidene, vinyl and trans-vinylene groups. Moreover, the emergence of a wide band without any structure around 1600 cm -1 reveals the presence of double bonds with different degrees of conjugation. By comparison with the modifications induced in polyethylene, we discuss the role played by the phenyl side group and we consider the multiple ionisation of the aromatic ring as one possible way to induce the observed modifications.

  8. Inertially confined fusion using heavy ion drivers

    SciTech Connect

    Herrmannsfeldt, W.B.; Bangerter, R.O.; Bock, R.; Hogan, W.J.; Lindl, J.D.

    1991-10-01

    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.

  9. Inertially confined fusion using heavy ion drivers

    SciTech Connect

    Herrmannsfeldt, W.B. ); Bangerter, R.O. ); Bock, R. ); Hogan, W.J.; Lindl, J.D. )

    1991-10-01

    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.

  10. Emission source functions in heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Shapoval, V. M.; Sinyukov, Yu. M.; Karpenko, Iu. A.

    2013-12-01

    Three-dimensional pion and kaon emission source functions are extracted from hydrokinetic model (HKM) simulations of central Au+Au collisions at the top Relativistic Heavy Ion Collider (RHIC) energy sNN=200 GeV. The model describes well the experimental data, previously obtained by the PHENIX and STAR collaborations using the imaging technique. In particular, the HKM reproduces the non-Gaussian heavy tails of the source function in the pair transverse momentum (out) and beam (long) directions, observed in the pion case and practically absent for kaons. The role of rescatterings and long-lived resonance decays in forming the mentioned long-range tails is investigated. The particle rescattering contribution to the out tail seems to be dominating. The model calculations also show substantial relative emission times between pions (with mean value 13 fm/c in the longitudinally comoving system), including those coming from resonance decays and rescatterings. A prediction is made for the source functions in Large Hadron Collider (LHC) Pb+Pb collisions at sNN=2.76 TeV, which are still not extracted from the measured correlation functions.

  11. Heavy-ion fusion hindrance at extreme sub-barrier energies.

    SciTech Connect

    Jiang, C. L.; Back, B. B.; Esbensen, H.; Janssens, R. V. F.; Misicu, S.; Rehm, K. E.; Collon, P.; Davids, C. N.; Greene, J.; Henderson, D. J.; Jisonna, L.; Kurtz, S.; Lister, C. J.; Notani, M.; Paul, M.; Pardo, R.; Peterson, D.; Seweryniak, D.; Shumard, B.; Tang, X. D.; Wang, X.; Zhu, S.; Physics; National Inst. for Nuclear Physics; Univ. of Notre Dame; Hebrew Univ.; Northwestern Univ.; Michigan State Univ.

    2006-01-01

    There are many new results in the study of the heavy-ion fusion hindrance phenomenon at extreme sub-barrier energies since Fusion03. Some of them have been published. Presented are some new results, including the first evidence in fusion hindrance for a system with small negative Q-value, {sup 28}Si + {sup 64}Ni, and the impact of fusion hindrance on reactions of interest to astrophysics.

  12. Multi-module model for ultra-relativistic heavy ion collisions.

    SciTech Connect

    Magas, V.; Csernai, L. P.; Strottman, D.

    2001-01-01

    The Multi Module Model for Ultra-Relativistic Heavy Ion Collisioiis at RHIC and LHC energies is presented. It uses the Effective String Rope Model for the calculation of the initial stages of the reaction; the output of this model is used as the initial state for the subsequent one-fluid calculations. It is shown that such an initial state leads to the creation of the third flow component. The hydrodynainical evolution of the energy density distribution is also presented.

  13. Microscopy and Cathodoluminescence Spectroscopy Characterization of Quartz Exhibiting Different Alkali-Silica Reaction Potential.

    PubMed

    Kuchařová, Aneta; Götze, Jens; Šachlová, Šárka; Pertold, Zdeněk; Přikryl, Richard

    2016-02-01

    Different quartz types from several localities in the Czech Republic and Sweden were examined by polarizing microscopy combined with cathodoluminescence (CL) microscopy, spectroscopy, and petrographic image analysis, and tested by use of an accelerated mortar bar test (following ASTM C1260). The highest alkali-silica reaction potential was indicated by very fine-grained chert, containing significant amounts of fine-grained to cryptocrystalline matrix. The chert exhibited a dark red CL emission band at ~640 nm with a low intensity. Fine-grained orthoquartzites, as well as fine-grained metamorphic vein quartz, separated from phyllite exhibited medium expansion values. The orthoquartzites showed various CL of quartz grains, from blue through violet, red, and brown. Two CL spectral bands at ~450 and ~630 nm, with various intensities, were detected. The quartz from phyllite displayed an inhomogeneous dark red CL with two CL spectral bands of low intensities at ~460 and ~640 nm. The massive coarse-grained pegmatite quartz from pegmatite was assessed to be nonreactive and displayed a typical short-lived blue CL (~480 nm). The higher reactivity of the fine-grained hydrothermal quartz may be connected with high concentrations of defect centers, and probably with amorphized micro-regions in the quartz, respectively; indicated by a yellow CL emission (~570 nm).

  14. Influence of steel fibers on the development of alkali-aggregate reaction

    SciTech Connect

    Pires de Carvalho, Maria Rita; Pagan Hasparyk, Nicole

    2010-04-15

    This work presents the results of an experimental research concerning the use of fibers in mortar specimens subjected to alkali-aggregate reaction (AAR). Two types of steel fibers (0.16 mm diameter and 6.0 mm length, and 0.20 mm diameter and 13.0 mm length) were used with fiber volume contents of 1% and 2%. Besides the expansion accelerated tests, compressive tests and flexural tests have also been carried out to display the main mechanical characteristics of the fiber-reinforced mortars after being subjected to AAR. Moreover, the microstructure of the specimens was analyzed by scanning electron microscopy and energy dispersive X-ray. The results shown that the addition of steel fibers reduced the expansion due to AAR for the experimental conditions studied in this paper. The most expressive benefit corresponded to the addition of 13.0 mm fibers in the mixture containing 2% fiber content. This fiber volume content also corresponded to the maximum increment in the mechanical properties compared to the reference mortar, mainly for the post-cracking strength and for the toughness in bending. It was observed that the fibers have a beneficial effect on the material, without compromising its main mechanical properties.

  15. Microscopy and Cathodoluminescence Spectroscopy Characterization of Quartz Exhibiting Different Alkali-Silica Reaction Potential.

    PubMed

    Kuchařová, Aneta; Götze, Jens; Šachlová, Šárka; Pertold, Zdeněk; Přikryl, Richard

    2016-02-01

    Different quartz types from several localities in the Czech Republic and Sweden were examined by polarizing microscopy combined with cathodoluminescence (CL) microscopy, spectroscopy, and petrographic image analysis, and tested by use of an accelerated mortar bar test (following ASTM C1260). The highest alkali-silica reaction potential was indicated by very fine-grained chert, containing significant amounts of fine-grained to cryptocrystalline matrix. The chert exhibited a dark red CL emission band at ~640 nm with a low intensity. Fine-grained orthoquartzites, as well as fine-grained metamorphic vein quartz, separated from phyllite exhibited medium expansion values. The orthoquartzites showed various CL of quartz grains, from blue through violet, red, and brown. Two CL spectral bands at ~450 and ~630 nm, with various intensities, were detected. The quartz from phyllite displayed an inhomogeneous dark red CL with two CL spectral bands of low intensities at ~460 and ~640 nm. The massive coarse-grained pegmatite quartz from pegmatite was assessed to be nonreactive and displayed a typical short-lived blue CL (~480 nm). The higher reactivity of the fine-grained hydrothermal quartz may be connected with high concentrations of defect centers, and probably with amorphized micro-regions in the quartz, respectively; indicated by a yellow CL emission (~570 nm). PMID:26790877

  16. Classification of alkali-silica reaction and corrosion distress using acoustic emission

    NASA Astrophysics Data System (ADS)

    Abdelrahman, Marwa; ElBatanouny, Mohamed; Serrato, Michael; Dixon, Kenneth; Larosche, Carl; Ziehl, Paul

    2016-02-01

    The Nuclear Regulatory Commission regulates approximately 100 commercial nuclear power reactor facilities that contribute about 20% of the total electric energy produced in the United States. Half of these reactor facilities are over 30 years old and are approaching their original design service life. Due to economic and durability considerations, significant portions of many of the facilities were constructed with reinforced concrete, including the containment facilities, cooling towers, and foundations. While most of these concrete facilities have performed exceptionally well throughout their initial expected service life, some are beginning to exhibit different forms of concrete deterioration. In this study, acoustic emission (AE) is used to monitor two main concrete deterioration mechanisms; alkali-silica reaction (ASR) distress and corrosion of reinforcing steel. An accelerated ASR test was conducted where specimens were continuously monitored with AE. The results show that AE can detect and classify damage due to ASR distress in the specimens. AE was also used to remotely monitor active corrosion regions in a reactor facility. AE monitoring of accelerated corrosion testing was also conducted on a concrete block specimen cut from a similar reactor building. Electrochemical measurements were conducted to correlate AE activity to quantifiable corrosion measurements and to enhance capabilities for service life prediction.

  17. HISTRAP proposal: heavy ion storage ring for atomic physics

    SciTech Connect

    Olsen, D.K.; Alton, G.D.; Datz, S.; Dittner, P.F.; Dowling, D.T.; Haynes, D.L.; Hudson, E.D.; Johnson, J.W.; Lee, I.Y.; Lord, R.S.

    1986-11-01

    HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charged very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will have a maximum bending power of 2.0 Tm and will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac.

  18. Silicon Carbide Power Device Performance Under Heavy-Ion Irradiation

    NASA Technical Reports Server (NTRS)

    Lauenstein, Jean-Marie; Casey, Megan; Topper, Alyson; Wilcox, Edward; Phan, Anthony; Ikpe, Stanley; LaBel, Ken

    2015-01-01

    Heavy-ion induced degradation and catastrophic failure data for SiC power MOSFETs and Schottky diodes are examined to provide insight into the challenge of single-event effect hardening of SiC power devices.

  19. New observations on the mechanism of lithium nitrate against alkali silica reaction (ASR)

    SciTech Connect

    Feng, X.; Thomas, M.D.A.; Bremner, T.W.; Folliard, K.J.; Fournier, B.

    2010-01-15

    In the current study, in order to elucidate the mechanisms for the favorable effects of lithium nitrate in controlling alkali silica reaction (ASR), vycor glass disk immersion specimens and glass disk-cement paste sandwich specimens were prepared and examined by XRD, SEM and Laser Ablation Induction Coupled Plasma Mass Spectrometry (LA-ICP-MS). Results showed that when glass disk was immersed in only NaOH solution, the glass was attacked by hydroxyl ions but no solid reaction product was found, thus the presence of calcium was essential for the formation of ASR gel. In the presence of lithium, the glass surface was covered by a thick layer of Li-Si crystal. With the addition of Ca(OH){sub 2}, the glass surface was completely covered by Li-Si crystal and a lithium-bearing low Ca-Na-(K)-Si gel. These two phases either form a dense matrix with Li-Si crystal serving as the framework, and the gel filling in the void space, or the Li-Si crystal serving as the foundation to completely cover the entire reactive SiO{sub 2} surface, and the gel sitting on top of these crystal particles. Hence, the suppressive effects of LiNO{sub 3} were attributed to the formation of a layer of Li-Si crystals intimately at the reactive SiO{sub 2} particle surface and the formation of Li-bearing low-Ca ASR gel products. The Li-bearing low-Ca ASR gels may have a dense and rigid structure, thus having low capacity to absorb moisture from the surrounding paste, and exhibiting a non-swelling property.

  20. Classical gluon production amplitude in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Chirilli, Giovanni Antonio

    2016-03-01

    The distribution of quarks and gluons produced in the initial stages of nuclear collisions, known as the initial condition of the Quark-Gluon Plasma formation, is the fundamental building block of heavy-ion theory. I will present the scattering amplitude, beyond the leading order, of the classical gluon produced in heavy-ion collisions. The result is obtained in the framework of saturation physics and Wilson lines formalism.

  1. HIGH-INTENSITY, HIGH CHARGE-STATE HEAVY ION SOURCES

    SciTech Connect

    ALESSI,J.G.

    2004-08-16

    There are many accelerator applications for high intensity heavy ion sources, with recent needs including dc beams for RIA, and pulsed beams for injection into synchrotrons such as RHIC and LHC. The present status of sources producing high currents of high charge state heavy ions is reviewed. These sources include ECR, EBIS, and Laser ion sources. Benefits and limitations for these type sources are described. Possible future improvements in these sources are also mentioned.

  2. Intense Pulsed Heavy Ion Beam Technology

    NASA Astrophysics Data System (ADS)

    Masugata, Katsumi; Ito, Hiroaki

    Development of intense pulsed heavy ion beam accelerator technology is described for the application of materials processing. Gas puff plasma gun and vacuum arc discharge plasma gun were developed as an active ion source for magnetically insulated pulsed ion diode. Source plasma of nitrogen and aluminum were successfully produced with the gas puff plasma gun and the vacuum arc plasma gun, respectively. The ion diode was successfully operated with gas puff plasma gun at diode voltage 190 kV, diode current 2.2 kA and nitrogen ion beam of ion current density 27 A/cm2 was obtained. The ion composition was evaluated by a Thomson parabola spectrometer and the purity of the nitrogen ion beam was estimated to be 86%. The diode also operated with aluminum ion source of vacuum arc plasma gun. The ion diode was operated at 200 kV, 12 kA, and aluminum ion beam of current density 230 A/cm2 was obtained. The beam consists of aluminum ions (Al(1-3)+) of energy 60-400 keV, and protons (90-130 keV), and the purity was estimated to be 89 %. The development of the bipolar pulse accelerator (BPA) was reported. A double coaxial type bipolar pulse generator was developed as the power supply of the BPA. The generator was tested with dummy load of 7.5 ohm, bipolar pulses of -138 kV, 72 ns (1st pulse) and +130 kV, 70 ns (2nd pulse) were succesively generated. By applying the bipolar pulse to the drift tube of the BPA, nitrogen ion beam of 2 A/cm2 was observed in the cathode, which suggests the bipolar pulse acceleration.

  3. The Relativistic Heavy Ion Collider control system

    SciTech Connect

    Clifford, T.S.; Barton, D.S.; Oerter, B.R.

    1997-12-01

    The Relativistic Heavy Ion Collider control system has been used in the commissioning of the AGS to RHIC transfer line and in the first RHIC sextant test. Much of the controls infrastructure for networks and links has been installed throughout the collider. All of the controls hardware modules needed to be built for early RHIC operations have been designed and tested. Many of these VME modules are already being used in normal AGS operations. Over 150 VME based front end computers and device controllers will be installed by the Summer of 1998 in order to be ready for Fall of 1998. A few features are being added to the front end computer core software. The bulk of the Accelerator Device Objects (ADOs) which are instantiated in the FECs, have been written and tested in the early commissioning. A configuration database has been designed. Generic control and display of ADO parameters via a spreadsheet like program on the console level computers was provided early on in the control system development. User interface tools that were developed for the AGS control system have been used in RHIC applications. Some of the basic operations programs, like alarm display and save/restore, that are used in the AGS operations have been or will be expanded to support RHIC operations. A model for application programs which involves a console level manager servicing ADOs have been verified with a few RHIC applications. More applications need to be written for the Fall of 1998 commissioning effort. A sequencer for automatic control of the fill is being written with the expectation that it will be useful in early commissioning.

  4. String theory and relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Friess, Joshua J.

    It has long been known that string theory describes not only quantum gravity, but also gauge theories with a high degree of supersymmetry. Said gauge theories also have a large number of colors in a regime with a large effective coupling constant that does not depend on energy scale. Supersymmetry is broken in nature, if it is present at all, however the gauge theory described by string theory shares many common features with QCD at temperatures above the quark deconfinement transition. It is generally though not entirely accepted that collisions of gold nuclei at the Relativistic Heavy Ion Collider (RHIC) produce a thermalized Quark-Gluon Plasma (QGP) at temperatures distinctly above the transition temperature as determined from lattice simulations. Hence, we might hope that a string theoretic description of gauge dynamics can elucidate some otherwise intractable physics of the strongly coupled plasma. Here we use string theory to calculate the outgoing energy flux from a RHIC process called "jet quenching", in which a high-momentum quark or gluon traverses a large distance in the QGP. Our setup is in the context of the highly supersymmetric string dual gauge theory, but we nevertheless find that the gross features of the resulting stress-energy tensor match reasonably well with experimental data. We will furthermore discuss the technology behind computations of the leading-order corrections to gauge theory observables that are uniquely string-induced, and we will describe a potential solution to string theory that could resolve a number of discrepancies between the traditional highly supersymmetric setup and QCD---in particular, a significant reduction in the amount of supersymmetry, and a finite effective coupling that is still greater than unity but does depend on energy scale.

  5. Pion correlations in relativistic heavy ion collisions at Heavy Ion Spectrometer Systems (HISS)

    SciTech Connect

    Christie, W.B. Jr.

    1990-05-01

    This thesis contains the setup, analysis and results of experiment E684H Multi-Pion Correlations in Relativistic Heavy Ion Collisions''. The goals of the original proposal were: (1) To initiate the use of the HISS facility in the study of central Relativistic Heavy Ion Collisions (RHIC). (2) To perform a second generation experiment for the detailed study of the pion source in RHIC. The first generation experiments, implied by the second goal above, refer to pion correlation studies which the Riverside group had performed at the LBL streamer chamber. The major advantage offered by moving the pion correlation studies to HISS is that, being an electronic detector system, as opposed to the Streamer Chamber which is a visual detector, one can greatly increase the statistics for a study of this sort. An additional advantage is that once one has written the necessary detector and physics analysis code to do a particular type of study, the study may be extended to investigate the systematics, with much less effort and in a relatively short time. This paper discusses the Physics motivation for this experiment, the experimental setup and detectors used, the pion correlation analysis, the results, and the conclusions possible future directions for pion studies at HISS. If one is not interested in all the details of the experiment, I believe that by reading the sections on intensity interferometry, the section the fitting of the correlation function and the systematic corrections applied, and the results section, one will get a fairly complete synopsis of the experiment.

  6. Unified mechanism of alkali and alkaline earth catalyzed gasification reactions of carbon by CO2 and H2O

    USGS Publications Warehouse

    Chen, S.G.; Yang, R.T.

    1997-01-01

    From molecular orbital calculations, a unified mechanism is proposed for the gasification reactions of graphite by CO2 and H2O, both uncatalyzed and catalyzed by alkali and alkaline earth catalysts. In this mechanism, there are two types of oxygen intermediates that are bonded to the active edge carbon atoms: an in-plane semiquinone type, Cf(O), and an off-plane oxygen bonded to two saturated carbon atoms that are adjacent to the semiquinone species, C(O)Cf(O). The rate-limiting step is the decomposition of these intermediates by breaking the C-C bonds that are connected to Cf(O). A new rate equation is derived for the uncatalyzed reactions, and that for the catalyzed reactions is readily available from the proposed mechanism. The proposed mechanism can account for several unresolved experimental observations: TPD and TK (transient kinetics) desorption results of the catalyzed systems, the similar activation energies for the uncatalyzed and catalyzed reactions, and the relative activities of the alkali and alkaline earth elements. The net charge of the edge carbon active site is substantially changed by gaining electron density from the alkali or alkaline earth element (by forming C-O-M, where M stands for metal). The relative catalytic activities of these elements can be correlated with their abilities of donating electrons and changing the net charge of the edge carbon atom. As shown previously (Chen, S. G.; Yang, R. T. J. Catal. 1993, 141, 102), only clusters of the alkali compounds are active. This derives from the ability of the clusters to dissociate CO2 and H2O to form O atoms and the mobility of the dissociated O atoms facilitated by the clusters.

  7. Estimates of Sputter Yields of Solar-Wind Heavy Ions of Lunar Regolith Materials

    NASA Technical Reports Server (NTRS)

    Barghouty, Abdulmasser F.; Adams, James H., Jr.

    2008-01-01

    At energies of approximately 1 keV/amu, solar-wind protons and heavy ions interact with the lunar surface materials via a number of microscopic interactions that include sputtering. Solar-wind induced sputtering is a main mechanism by which the composition of the topmost layers of the lunar surface can change, dynamically and preferentially. This work concentrates on sputtering induced by solar-wind heavy ions. Sputtering associated with slow (speeds the electrons speed in its first Bohr orbit) and highly charged ions are known to include both kinetic and potential sputtering. Potential sputtering enjoys some unique characteristics that makes it of special interest to lunar science and exploration. Unlike the yield from kinetic sputtering where simulation and approximation schemes exist, the yield from potential sputtering is not as easy to estimate. This work will present a preliminary numerical scheme designed to estimate potential sputtering yields from reactions relevant to this aspect of solar-wind lunar-surface coupling.

  8. Physics perspectives of heavy-ion collisions at very high energy

    DOE PAGESBeta

    Chang, Ning-bo; Cao, ShanShan; Chen, Bao-yi; Chen, Shi-yong; Chen, Zhen-yu; Ding, Heng-Tong; He, Min; Liu, Zhi-quan; Pang, Long-gang; Qin, Guang-you; et al

    2016-01-15

    We expect heavy-ion collisions at very high colliding energies to produce a quark-gluon plasma (QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide an unprecedented range of information on properties of the QGP at high temperatures. We also report theoretical investigations of the physics perspectives of heavy-ion collisions at a future high-energy collider. These include initial parton production, collective expansion of the dense medium, jet quenching, heavy-quark transport, dissociation and regeneration of quarkonia, photon and dilepton production. Here, we illustrate the potential of future experimental studies of the initial particle production andmore » formation of QGP at the highest temperature to provide constraints on properties of strongly interaction matter.« less

  9. Heavy ion induced mutations in mammalian cells: Cross sections and molecular analysis

    NASA Technical Reports Server (NTRS)

    Stoll, U.; Schmidt, P.; Schneider, E.; Kiefer, J.

    1994-01-01

    Our investigations of heavy ion-induced mutations in mammalian cells, which had been begun a few years ago, were systematically continued. For the first time, it was possible to cover a large LET range with a few kinds of ions. To do this, both UNILAC and SIS were used to yield comparable data for a large energy range. This is a necessary condition for a comprehensive description of the influence of such ion parameters as energy and LET. In these experiments, the induced resistance against the poison 6-thioguanin (6-TG), which is linked to the HPRT locus on the genome, is being used as mutation system. In addition to the mutation-induction cross-section measurements, the molecular changes of the DNA are being investigated by means of Multiplex PCR ('Polymerase Chain Reaction') gene amplification. From these experiments we expect further elucidation of the mutation-inducing mechanisms composing the biological action of heavy-ion radiation.

  10. A particle-hole calculation for pion production in relativistic heavy-ion collisions

    NASA Technical Reports Server (NTRS)

    Norbury, J. W.; Deutchman, P. A.; Townsend, L. W.

    1985-01-01

    A differential cross section for pi-meson production in peripheral heavy-ion collisions is formulated within the context of a particle-hole model in the Tamm-Dancoff approximation. This is the first attempt at a fully quantum-mechanical particle-hole calculation for pion production in relativistic heavy-ion collisions. The particular reaction studied is an O-16 projectile colliding with a C-12 target at rest. In the projectile a linear combination of isobar-hole states is formed, with the possibility of a coherent isobar giant resonance. The target can be excited to its giant M1 resonance (J-pi = 1(+), T = 1) at 15.11 MeV, or to its isobar analog neighbors, B-12 at 13.4 MeV and N-12 at 17.5 MeV. The theory is compared to recent experimental results.

  11. Dynamics of strangeness production in heavy-ion collisions near threshold energies

    SciTech Connect

    Feng Zhaoqing; Jin Genming

    2010-11-15

    Within the framework of the improved isospin-dependent quantum molecular dynamics (ImIQMD) model, the dynamics of strangeness (K{sup 0,+}, {Lambda}, and {Sigma}{sup -,0,+}) production in heavy-ion collisions near threshold energies is investigated systematically, with the strange particles considered to be produced mainly by inelastic collisions of baryon-baryon and pion-baryon. Collisions in the region of suprasaturation densities of the dense baryonic matter formed in heavy-ion collisions dominate the yields of strangeness production. Total multiplicities as functions of incident energies and collision centralities are calculated with the Skyrme parameter SLy6. The excitation function of strangeness production is analyzed and also compared with the KaoS data for K{sup +} production in the reactions {sup 12}C+{sup 12}C and {sup 197}Au+{sup 197}Au.

  12. A new version of JQMD for soft heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Mancusi, Davide; Niita, Koji; Sihver, Lembit

    The JQMD model (JAERI Quantum Molecular Dynamics) has been successfully used for a long time now to describe many different aspects of nuclear reactions in a unified way. However, in soft, peripheral heavy-ion collisions, the JQMD model shows instabilities and spurious fluctuations that are responsible for an overestimation of few-nucleon-removal cross sections. The reasons of this shortcoming are, firstly, that the JQMD is not fully relativistically covariant, and secondly, that the fermionic nature of the nuclear ground state cannot be faithfully reproduced in a semi-classical framework. We present here R-JQMD, an improved and fully covariant version of JQMD that also features a new ground-state initialisation algorithm for nuclei. The new code is only marginally slower than JQMD and it produces physically sounder results. We also discuss whether R-JQMD can be adjusted to improve JQMD's agreement with measured heavy-ion fragmentation cross sections.

  13. Thermal electromagnetic radiation in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Rapp, R.; van Hees, H.

    2016-08-01

    We review the potential of precise measurements of electromagnetic probes in relativistic heavy-ion collisions for the theoretical understanding of strongly interacting matter. The penetrating nature of photons and dileptons implies that they can carry undistorted information about the hot and dense regions of the fireballs formed in these reactions and thus provide a unique opportunity to measure the electromagnetic spectral function of QCD matter as a function of both invariant mass and momentum. In particular we report on recent progress on how the medium modifications of the (dominant) isovector part of the vector current correlator ( ρ channel) can shed light on the mechanism of chiral symmetry restoration in the hot and/or dense environment. In addition, thermal dilepton radiation enables novel access to a) the fireball lifetime through the dilepton yield in the low invariant-mass window 0.3 GeV ≤ M ≤ 0.7 GeV, and b) the early temperatures of the fireball through the slope of the invariant-mass spectrum in the intermediate-mass region (1.5 GeV < M < 2.5 GeV). The investigation of the pertinent excitation function suggests that the beam energies provided by the NICA and FAIR projects are in a promising range for a potential discovery of the onset of a first-order phase transition, as signaled by a non-monotonous behavior of both low-mass yields and temperature slopes.

  14. Biophysical aspects of heavy ion interactions in matter

    NASA Technical Reports Server (NTRS)

    Schimmerling, Walter; Wong, Mervyn; Ludewigt, Bernhard; Phillips, Mark; Alpen, Edward L.; Powers-Risius, Patricia; Deguzman, Randy J.; Townsend, Larry W.; Wilson, John W.

    1989-01-01

    The biological effects of high energy, high charge nuclei (HZE particles) occupy a central role in the management of space radiation hazards due to galactic cosmic rays. For the energy range of interest, the mean free path for nuclear interactions of these heavy ions is comparable to the thickness of the material traversed, and a significant fraction of stopping particles will undergo a nuclear reaction with the nuclei of the stopping material. Transport methods for HZE particles are dependent on models of the interaction of man-made systems with the space environment to an even greater extent than methods used for other types of radiation. Hence, there is a major need to validate these transport codes by comparison with experimental data. The basic physical properties of HZE particles will be reviewed and illustrated with the results of nuclear fragmentation experiments performed with 670A MeV neon ions incident on a water absorber and with measurements of multiple Coulomb scattering of uranium beams in copper. Finally, the extent to which physical measurements yield radiobiological predictions is illustrated for the example of neon.

  15. Two-pion correlations in heavy ion collisions

    SciTech Connect

    Zajc, W.A.

    1982-08-01

    An application of intensity interferometry to relativistic heavy ion collisions is reported. Specifically, the correlation between two like-charged pions is used to study the reactions Ar+KCl..-->..2..pi../sup +-/+X and Ne+NaF..-->..2..pi../sup -/+X. Source sizes are obtained that are consistent with a simple geometric interpretation. Lifetimes are less well determined but are indicative of a faster pion production process than predicted by Monte Carlo cascade calculations. There appears to be a substantial coherent component of the pion source, although measurement is complicated by the presence of final state interactions. Additionally, the generation of spectra of uncorrelated events is discussed. In particular, the influence of the correlation function on the background spectrum is analyzed, and a prescription for removal of this influence is given. A formulation to describe the statistical errors in the background is also presented. Finally, drawing from the available literature, a self-contained introduction to Bose-Einstein correlations and the Hanbury-Brown - Twiss effect is provided, with an emphasis on points of contact between classical and quantum mechanical descriptions.

  16. Facile nucleophilic fluorination reactions using tert-alcohols as a reaction medium: significantly enhanced reactivity of alkali metal fluorides and improved selectivity.

    PubMed

    Kim, Dong Wook; Jeong, Hwan-Jeong; Lim, Seok Tae; Sohn, Myung-Hee; Katzenellenbogen, John A; Chi, Dae Yoon

    2008-02-01

    Although protic solvents are generally not preferred for nucleophilic displacement reactions because of their partial positive charge and hydrogen-bonding capacity that solvate the nucleophile and reduce its reactivity, we recently reported a remarkably beneficial effect of using tertiary alcohols as a reaction media for nucleophilic fluorination with alkali metal fluorides, as well as fluorine-18 radiolabeling with [18F]fluoride ion for the preparation of PET radiopharmaceuticals. In this work, we investigate further the influence of the tert-alcohol reaction medium for nucleophilic fluorination with alkali metal fluorides by studying various interactions among tert-alcohols, the alkali metal fluoride (CsF), and the sulfonyloxy substrate. Factors such as hydrogen bonding between CsF and the tert-alcohol solvent, the formation of a tert-alcohol solvated fluoride, and hydrogen bonding between the sulfonate leaving group and the tert-alcohol appear to contribute to the dramatic increase in the rate of the nucleophilic fluorination reaction in the absence of any kind of catalyst. We found that fluorination of 1-(2-mesyloxyethyl)naphthalene (5) and N-5-bromopentanoyl-3,4-dimethoxyaniline (8) with Bu(4)N(+)F(-) in a tert-alcohol afforded the corresponding fluoro products in much higher yield than obtained by the conventional methods using dipolar aprotic solvents. The protic medium also suppresses formation of byproducts, such as alkenes, ethers, and cyclic adducts.

  17. Particle production in {radical}(s{sub NN})=2.76 TeV heavy ion collisions

    SciTech Connect

    Rafelski, Johann; Letessier, Jean

    2011-05-15

    We obtain within the statistical hadronization model (SHM) the hadron yields dh/dy in heavy ion reactions at {radical}(s{sub NN})=2.76 TeV. We discuss the dependence both on hadronization temperature T and on critical hadronization pressure P. We consider observables distinguishing the hadronization models and conditions.

  18. EDITORIAL: Focus on Heavy Ions in Biophysics and Medical Physics FOCUS ON HEAVY IONS IN BIOPHYSICS AND MEDICAL PHYSICS

    NASA Astrophysics Data System (ADS)

    Durante, Marco

    2008-07-01

    Interest in energetic heavy ions is rapidly increasing in the field of biomedicine. Heavy ions are normally excluded from radiation protection, because they are not normally experienced by humans on Earth. However, knowledge of heavy ion biophysics is necessary in two fields: charged particle cancer therapy (hadrontherapy), and radiation protection in space missions. The possibility to cure tumours using accelerated heavy charged particles was first tested in Berkeley in the sixties, but results were not satisfactory. However, about 15 years ago therapy with carbon ions was resumed first in Japan and then in Europe. Heavy ions are preferable to photons for both physical and biological characteristics: the Bragg peak and limited lateral diffusion ensure a conformal dose distribution, while the high relative biological effectiveness and low oxygen enhancement ration in the Bragg peak region make the beam very effective in treating radioresistant and hypoxic tumours. Recent results coming from the National Institute of Radiological Sciences in Chiba (see the paper by Dr Tsujii and co-workers in this issue) and GSI (Germany) provide strong clinical evidence that heavy ions are indeed an extremely effective weapon in the fight against cancer. However, more research is needed in the field, especially on optimization of the treatment planning and risk of late effects in normal tissue, including secondary cancers. On the other hand, high-energy heavy ions are present in galactic cosmic radiation and, although they are rare as compared to protons, they give a major contribution in terms of equivalent dose to the crews of manned space exploratory-class missions. Exploration of the Solar System is now the main goal of the space program, and the risk caused by exposure to galactic cosmic radiation is considered a serious hindrance toward this goal, because of the high uncertainty on late effects of energetic heavy nuclei, and the lack of effective countermeasures. Risks

  19. THERMALIZATION OF HEAVY IONS IN THE SOLAR WIND

    SciTech Connect

    Tracy, Patrick J.; Kasper, Justin C.; Zurbuchen, Thomas H.; Raines, Jim M.; Shearer, Paul; Gilbert, Jason

    2015-10-20

    Observations of velocity distribution functions from the Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer heavy ion composition instrument are used to calculate ratios of kinetic temperature and Coulomb collisional interactions of an unprecedented 50 ion species in the solar wind. These ions cover a mass per charge range of 1–5.5 amu/e and were collected in the time range of 1998–2011. We report the first calculation of the Coulomb thermalization rate between each of the heavy ion (A > 4 amu) species present in the solar wind along with protons (H{sup +}) and alpha particles (He{sup 2+}). From these rates, we find that protons are the dominant source of Coulomb collisional thermalization for heavy ions in the solar wind and use this fact to calculate a collisional age for those heavy ion populations. The heavy ion thermal properties are well organized by this collisional age, but we find that the temperature of all heavy ions does not simply approach that of protons as Coulomb collisions become more important. We show that He{sup 2+} and C{sup 6+} follow a monotonic decay toward equal temperatures with protons with increasing collisional age, but O{sup 6+} shows a noted deviation from this monotonic decay. Furthermore, we show that the deviation from monotonic decay for O{sup 6+} occurs in solar wind of all origins, as determined by its Fe/O ratio. The observed differences in heavy ion temperature behavior point toward a local heating mechanism that favors ions depending on their charge and mass.

  20. Robust heavy-ion-beam illumination in direct-driven heavy-ion inertial fusion

    NASA Astrophysics Data System (ADS)

    Kawata, S.; Miyazawa, K.; Ogoyski, A. I.; Someya, T.; Kikuchi, T.

    2007-07-01

    In heavy ion beam (HIB) inertial confinement fusion (HIF), implosion asymmetry should be less than a few percent in order to compress a fuel sufficiently and release fusion energy effectively. It is known that the HIB illumination nonuniformity and implosion symmetry are sensitive to a little pellet displacement from a reactor chamber center. We present a new HIB illumination scheme which is robust against the displacement of a direct-driven fuel pellet in an HIF reactor chamber. In conventional HIB illumination schemes a pellet displacement of 25-100 μm was tolerable. The new robust HIB illumination scheme is examined by three-dimensional computer simulations. In the new HIB illumination scheme the tolerable pellet displacement is about 200-300 μm.

  1. Heavy Ion Effects on Kelvin-Helmholtz Instability: Hybrid Study

    NASA Astrophysics Data System (ADS)

    Burgess, D.; Lin, D.

    2015-12-01

    Kelvin-Helmholtz instability (KHI) is a candidate mechanism for solar wind tansportation into the magnetosphere. The statistical study of Bouhram et al. 2005 has shown that heavy ions could dominate the magnetopause for as much as 30% of the time on the dusk side. Thus the influence of heavy ions in solar wind-magnetosphere coupling should not be neglected. However, the magnetohydrodynamic (MHD) linear theory for KHI does not include any ion effects, and people working on the heavy ion effects have not come to an agreement either. Whether the heavy ions promote or inhibit the KHI still remains not well addressed. With a two-dimensional hybrid model, we investigated the effects of ion mass number on the KHI growth rate, starting from the simplest case of uniform density and uniform magnetic field perpendicular to the shear flow. It is shown that the growth rate of the KHI is lower with a heavier mass number. We try to to derive the linear theory for the kinetic KHI and compare it with the hybrid simulation results. The linear theory with ion effects considered is going to be further verified with varying heavy ion fractions and finite magnetic shear. More implications for the dawn-dusk asymmetry of KHI on planetary magnetopause are desirable when comparing the results of opposite magnetic field directions relative to the flow vorticity.

  2. Physical Modelling of Proton and Heavy Ion Radiation using Geant4

    NASA Astrophysics Data System (ADS)

    Douglass, M.; Bezak, E.

    2012-10-01

    Protons and heavy ion particles are considered to be ideal particles for use in external beam radiotherapy due to superior properties of the dose distribution that results when these particles are incident externally and due to their relative biological effectiveness. While significant research has been performed into the properties and physical dose characteristics of heavy ions, the nuclear reactions (direct and fragmentation) undergone by He4, C12 and Ne20 nuclei used in radiotherapy in materials other than water is still largely unexplored. In the current project, input code was developed for the Monte Carlo toolkit Geant 4 version 9.3 to simulate the transport of several mono-energetic heavy ions through water. The relative dose contributions from secondary particles and nuclear fragments originating from the primary particles were investigated for each ion in both water and dense bone (ICRU) media. The results indicated that the relative contribution to the total physical dose from nuclear fragments increased with both increasing particle mass and with increasing medium density. In the case of 150 MeV protons, secondary particles were shown to contribute less than 0.5% of the peak dose and as high as 25% when using 10570 MeV neon ions in bone. When water was substituted for a bone medium, the contributions from fragments increased by more than 6% for C12 and Ne20.

  3. Matching stages of heavy-ion collision models

    SciTech Connect

    Cheng Yun; Csernai, L. P.; Magas, V. K.; Schlei, B. R.; Strottman, D.

    2010-06-15

    Heavy-ion reactions and other collective dynamical processes are frequently described by different theoretical approaches for the different stages of the process, like initial equilibration stage, intermediate locally equilibrated fluid dynamical stage, and final freeze-out stage. For the last stage, the best known is the Cooper-Frye description used to generate the phase space distribution of emitted, noninteracting particles from a fluid dynamical expansion or explosion, assuming a final ideal gas distribution, or (less frequently) an out-of-equilibrium distribution. In this work we do not want to replace the Cooper-Frye description, but rather clarify the ways of using it and how to choose the parameters of the distribution and, eventually, how to choose the form of the phase space distribution used in the Cooper-Frye formula. Moreover, the Cooper-Frye formula is used in connection with the freeze-out problem, while the discussion of transition between different stages of the collision is applicable to other transitions also. More recently, hadronization and molecular dynamics models have been matched to the end of a fluid dynamical stage to describe hadronization and freeze-out. The stages of the model description can be matched to each other on space-time hypersurfaces (just like through the frequently used freeze-out hypersurface). This work presents a generalized description of how to match the stages of the description of a reaction to each other, extending the methodology used at freeze-out, in simple covariant form which is easily applicable in its simplest version for most applications.

  4. Heavy ion precompound phenomena: A glance at hard gamma and subthreshold pion production

    SciTech Connect

    Blann, M.; Remington, B.A.

    1987-08-01

    We test a relaxation model based on two body nucleon-nucleon scattering processes to interpret phenomena observed in heavy ion reactions. We use the Boltzmann master equation to accomplish this. By assuming that the projectile nucleons share the total excitation with equal a-priori probability of all configurations, we are able to reproduce several sets of neutron spectra from /sup 20/Ne and /sup 12/C induced reactions on /sup 165/Ho. With no additional free parameters our model successfully reproduces subthreshold pion production cross sections, high energy ..gamma..-ray spectra, and angular distributions of high energy ..gamma..-rays. 40 refs., 12 figs., 2 tabs.

  5. Fusion measurements in light and medium mass heavy-ion reactions. Progress report, June 1, 1979-May 31, 1980. [Univ. of Kansas, 6/1/79-5/31/80

    SciTech Connect

    Prosser, F.W.

    1980-01-01

    Data were obtained on the ..gamma..-ray yield from the fusion reactions of /sup 16/ /sup 18/O + /sup 24/ /sup 26/Mg in the 25 to 70 MeV energy range. Analysis of these data in terms of the relative yields of specific residues as a function of bombarding energy is almost complete for /sup 16/O + /sup 26/Mg. Of particular interest will be a comparison of these results with those for /sup 18/O + /sup 24/Mg. The investigation of the fusion cross sections of /sup 16/O + /sup 24/ /sup 26/Mg was extended from 70 MeV to 140 MeV. An unexpected decrease in the fusion cross sections begins at about 100 MeV and persists to the highest energy obtained. This investigation will be continued to 170 MeV and expanded to include /sup 18/O + /sup 24/Mg. Data were obtained on the interaction of /sup 16/O + /sup 40/Ca at 128 MeV to determine the reaction mechanisms, other than fusion, present at higher energy. Plans for continuation of these experiments and for new experiments are discussed. A major effort has been the development of new programing to take advantage of a new color graphics interactive terminal for data analysis. No data of significance are included with this report; completed work will be published. 2 figures. (RWR)

  6. Characterizing the Energetic Heavy Ion Environment Inside 4 Jovian Radii

    NASA Astrophysics Data System (ADS)

    Cohen, C. M.; Stone, E. C.

    2004-05-01

    On 21 September 2003 Galileo impacted Jupiter to end its 8-year tour of the Jovian magentosphere. During this last phase data was collected in the very inner part of the magnetosphere at distances < 4 Rj. The region from 2 to 4 Rj was previously explored by Galileo during its 34th orbit around Jupiter. We present the combined data from these two passes obtained by the Heavy Ion Counter (HIC) for heavy ions at energies above 2 MeV/nucleon. In particular we discuss the significant ion absorption near the moons Thebe and Amalthea, the anisotropic pitch angle distribution and the dramatic increase in heavy ion intensity with decreasing radius seen in this region

  7. Direct-driven target implosion in heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Noguchi, K.; Suzuki, T.; Kurosaki, T.; Barada, D.; Kawata, S.; Ma, Y. Y.; Ogoyski, A. I.

    2016-03-01

    In inertial confinement fusion, the driver beam illumination non-uniformity leads a degradation of fusion energy output. A fuel target alignment error would happen in a fusion reactor; the target alignment error induces heavy ion beam illumination non-uniformity on a target. On the other hand, heavy ion beam accelerator provides a capability to oscillate a beam axis with a high frequency. The wobbling beams may provide a new method to reduce or smooth the beam illumination non-uniformity. First we study the effect of driver irradiation non-uniformity induced by the target alignment error (dz) on the target implosion. We found that dz should be less than about 130 μm for a sufficient fusion energy output. We also optimize the wobbling scheme. The spiral wobbling heavy ion beams would provide a promissing scheme to the uniform beam illumination.

  8. Ultra-relativistic heavy ions and cosmic rays

    SciTech Connect

    McLerran, L.

    1983-05-01

    The collisions of ultra-relativistic heavy ions, E/sub /N/ greater than or equal to 1 TeV/nucleon are most interesting, since, at these energies, matter is produced at sufficiently high energy density that a quark-gluon plasma has a good chance to form. Very heavy ions are also most interesting since the matter forms in a larger volume than for light ions, and the matter is at a somewhat higher energy density. At very high energies with very heavy ions there is great flexibility in the experimental signals which might be studied, as well as the nature of the matter which is produced. The fragmentation region and central region provide different environments where a plasma might form. The former is baryon rich while the central region is high temperature with low baryon number density and is not accessible except at very high energies.

  9. Heavy Ion Heating at Shocks in the Heliosphere

    NASA Astrophysics Data System (ADS)

    Korreck, K. E.; Stevens, M. L.; Lepri, S. T.; Kasper, J. C.

    2014-12-01

    Ions heavier than protons can be used as tracers for heating mechamisms in solar wind plasma. Measurments by the ACE and WIND satellites provide information on the relative heating of the heavy ions versus the protons. Greater than mass proportional heating has been seen at coronal mass ejections (CME) shock fronts. Using ACE SWICS heavy ions data from CME associated shocks, heavy ion heating and the non-thermal nature of helium and oxygen distributions at 1AU is examined. The WIND SWE data set is used to examine the helium distributions at the shock fronts observed at the spacecraft. Understanding the heating and source of energetic particles and their evolution through the heliosphere is relevant to predicting space weather events and the evolution of the solar wind.

  10. The Path to Heavy Ions at LHC and Beyond

    NASA Astrophysics Data System (ADS)

    Gutbrod, Hans H.

    My appreciation of Rolf Hagedorn motivates me to look back at my more than 40 years of trial and error in relativistic heavy ion physics. More than once, wise colleagues helped me move forward to new and better understandings. Rolf Hagedorn was one of these important people. At first, I met him anonymously in the mid 1970s when reading his 1971 Cargèse Lectures in Physics, and later in person for many years in and around CERN. I wonder what this modest person would say about his impact on physics in this millennium. As he is not here to answer, I and others give our answers in this book. I focus my report on the beginning of the research program with relativistic heavy ions, the move to CERN-SPS and the development of the heavy ion collaboration at the CERN-LHC.

  11. HISTRAP proposal: heavy ion storage ring for atomic physics

    SciTech Connect

    Olsen, D.K.; Alton, G.D.; Datz, S.; Dittner, P.F.; Dowling, D.T.; Haynes, D.L.; Hudson, E.D.; Johnson, J.W.; Lee, I.Y.; Lord, R.S.

    1986-01-01

    HISTRAP is a proposed synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charged very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac. The ring will have a maximum bending power of 2.0 T.m and have a circumference of 46.8 m.

  12. INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMS

    SciTech Connect

    Sharp, W. M.; Friedman, A.; Grote, D. P.; Barnard, J. J.; Cohen, R. H.; Dorf, M. A.; Lund, S. M.; Perkins, L. J.; Terry, M. R.; Logan, B. G.; Bieniosek, F. M.; Faltens, A.; Henestroza, E.; Jung, J. Y.; Kwan, J. W.; Lee, E. P.; Lidia, S. M.; Ni, P. A.; Reginato, L. L.; Roy, P. K.; Seidl, P. A.; Takakuwa, J. H.; Vay, J.-L.; Waldron, W. L.; Davidson, R. C.; Gilson, E. P.; Kaganovich, I. D.; Qin, H.; Startsev, E.; Haber, I.; Kishek, R. A.; Koniges, A. E.

    2011-03-31

    Intense heavy-ion beams have long been considered a promising driver option for inertial-fusion energy production. This paper briefly compares inertial confinement fusion (ICF) to the more-familiar magnetic-confinement approach and presents some advantages of using beams of heavy ions to drive ICF instead of lasers. Key design choices in heavy-ion fusion (HIF) facilities are discussed, particularly the type of accelerator. We then review experiments carried out at Lawrence Berkeley National Laboratory (LBNL) over the past thirty years to understand various aspects of HIF driver physics. A brief review follows of present HIF research in the US and abroad, focusing on a new facility, NDCX-II, being built at LBNL to study the physics of warm dense matter heated by ions, as well as aspects of HIF target physics. Future research directions are briefly summarized.

  13. Laser ion source for high brightness heavy ion beam

    NASA Astrophysics Data System (ADS)

    Okamura, M.

    2016-09-01

    A laser ion source is known as a high current high charge state heavy ion source. However we place great emphasis on the capability to realize a high brightness ion source. A laser ion source has a pinpoint small volume where materials are ionized and can achieve quite uniform low temperature ion beam. Those features may enable us to realize very small emittance beams. In 2014, a low charge state high brightness laser ion source was successfully commissioned in Brookhaven National Laboratory. Now most of all the solid based heavy ions are being provided from the laser ion source for regular operation.

  14. Heavy-ion-induced electronic desorption of gas from metals.

    PubMed

    Molvik, A W; Kollmus, H; Mahner, E; Covo, M Kireeff; Bellachioma, M C; Bender, M; Bieniosek, F M; Hedlund, E; Krämer, A; Kwan, J; Malyshev, O B; Prost, L; Seidl, P A; Westenskow, G; Westerberg, L

    2007-02-01

    During heavy-ion operation in several particle accelerators worldwide, dynamic pressure rises of orders of magnitude were triggered by lost beam ions that bombarded the vacuum chamber walls. This ion-induced molecular desorption, observed at CERN, GSI, and BNL, can seriously limit the ion beam lifetime and intensity of the accelerator. From dedicated test stand experiments we have discovered that heavy-ion-induced gas desorption scales with the electronic energy loss (dE_{e}/dx) of the ions slowing down in matter; but it varies only little with the ion impact angle, unlike electronic sputtering. PMID:17358950

  15. Heavy-ion induced electronic desorption of gas from metals

    SciTech Connect

    Molvik, A W; Kollmus, H; Mahner, E; Covo, M K; Bellachioma, M C; Bender, M; Bieniosek, F M; Hedlund, E; Kramer, A; Kwan, J; Malyshev, O B; Prost, L; Seidl, P A; Westenskow, G; Westerberg, L

    2006-12-19

    During heavy ion operation in several particle accelerators world-wide, dynamic pressure rises of orders of magnitude were triggered by lost beam ions that bombarded the vacuum chamber walls. This ion-induced molecular desorption, observed at CERN, GSI, and BNL, can seriously limit the ion beam lifetime and intensity of the accelerator. From dedicated test stand experiments we have discovered that heavy-ion induced gas desorption scales with the electronic energy loss (dE{sub e}/d/dx) of the ions slowing down in matter; but it varies only little with the ion impact angle, unlike electronic sputtering.

  16. Laser ion source for isobaric heavy ion collider experiment.

    PubMed

    Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

    2016-02-01

    Heavy-ion collider experiment in isobaric system is under investigation at Relativistic Heavy Ion Collider. For this experiment, ion source is required to maximize the abundance of the intended isotope. The candidate of the experiment is (96)Ru + (96)Zr. Since the natural abundance of particular isotope is low and composition of isotope from ion source depends on the composites of the target, an isotope enriched material may be needed as a target. We studied the performance of the laser ion source required for the experiment for Zr ions.

  17. Development of Superconducting Focusing Quadrupoles for Heavy Ion Drivers

    SciTech Connect

    Martovetsky, N; Manahan, R; Lietzke, A F

    2001-09-10

    Heavy Ion Fusion (HIF) is exploring a promising path to a practical inertial-confinement fusion reactor. The associated heavy ion driver will require a large number of focusing quadrupole magnets. A concept for a superconducting quadrupole array, using many simple racetrack coils, was developed at LLNL. Two, single-bore quadrupole prototypes of the same design, with distinctly different conductor, were designed, built, and tested. Both prototypes reached their short sample currents with little or no training. Magnet design, and test results, are presented and discussed.

  18. Heavy ions at steamboat: summary of parallel sessions

    SciTech Connect

    Ludlam, T.W.

    1984-01-01

    The interest in heavy ions at the intersection between particle and nuclear physics is motivated by the opportunity for an entirely new approach to the understanding of fundamental interactions by studying extreme states of nuclear matter. At this conference we have seen important new results on some of the central issues including: (1) how well can we predict the landscape of the extremes - that is, the phase structure of QCD and nuclear matter; (2) can we explore it with heavy ion collisions; and (3) can we recognize the appearance of new terrain. Our present understanding of the behavior of nuclear matter under extreme conditions is briefly discussed. 16 references. (WHK)

  19. Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Xiao, Zhi-Gang; Yong, Gao-Chan; Chen, Lie-Wen; Li, Bao-An; Zhang, Ming; Xiao, Guo-Qing; Xu, Nu

    2014-02-01

    The high-density behavior of nuclear symmetry energy is among the most uncertain properties of dense neutron-rich matter. Its accurate determination has significant ramifications in understanding not only the reaction dynamics of heavy-ion reactions, especially those induced by radioactive beams, but also many interesting phenomena in astrophysics, such as the explosion mechanism of supernova and the properties of neutron stars. The heavy-ion physics community has devoted much effort during the last few years to constrain the high-density symmetry using various probes. In particular, the / ratio has been most extensively studied both theoretically and experimentally. All models have consistently predicted qualitatively that the / ratio is a sensitive probe of the high-density symmetry energy especially with beam energies near the pion production threshold. However, the predicted values of the / ratio are still quite model dependent mostly because of the complexity of modeling pion production and reabsorption dynamics in heavy-ion collisions, leading to currently still controversial conclusions regarding the high-density behavior of nuclear symmetry energy from comparing various model calculations with available experimental data. As more / data become available and a deeper understanding about the pion dynamics in heavy-ion reactions is obtained, more penetrating probes, such as the K +/ K 0 ratio, meson and high-energy photons are also being investigated or planned at several facilities. Here, we review some of our recent contributions to the community effort of constraining the high-density behavior of nuclear symmetry energy in heavy-ion collisions. In addition, the status of some worldwide experiments for studying the high-density symmetry energy, including the HIRFL-CSR external target experiment (CEE) are briefly introduced.

  20. Heavy ion action on single cells: Cellular inactivation capability of single accelerated heavy ions

    NASA Technical Reports Server (NTRS)

    Kost, M.; Pross, H.-D.; Russmann, C.; Schneider, E.; Kiefer, J.; Kraft, G.; Lenz, G.; Becher, W.

    1994-01-01

    Heavy ions (HZE-particles) constitute an important part of radiation in space. Although their number is small the high amount of energy transferred by individual particles may cause severe biological effects. Their investigation requires special techniques which were tested by experiments performed at the UNILAC at the GSI (Darmstadt). Diploid yeast was used which is a suitable eucaryotic test system because of its resistance to extreme conditions like dryness and vacuum. Cells were placed on nuclear track detector foils and exposed to ions of different atomic number and energy. To assess the action of one single ion on an individual cell, track parameters and the respective colony forming abilities (CFA) were determined with the help of computer aided image analysis. There is mounting evidence that not only the amount of energy deposited along the particle path, commonly given by the LET, is of importance but also the spatial problem of energy deposition at a submicroscopical scale. It is virtually impossible to investigate track structure effects in detail with whole cell populations and (globally applied) high particle fluences. It is, therefore, necessary to detect the action of simple ions in individual cells. The results show that the biological action depends on atomic number and specific energy of the impinging ions, which can be compared with model calculations of recent track structure models.

  1. The chromatic correction in RHIC (Relativistic Heavy Ion Collider)

    SciTech Connect

    Lee, S.Y.; Dell, G.F.; Hahn, H.; Parzen, G.

    1987-01-01

    The scheme for the correction of chromatic effects in the Relativistic Heavy Ion Collider at BNL is discussed. This scheme uses six families of sextupoles excited by four independent power supplies, and provides adequate control of linear and quadratic terms in the tune vs momentum dependence and reduces the variation of the betatron amplitude, vs momentum.

  2. Inferring Magnetospheric Heavy Ion Density using EMIC Waves

    SciTech Connect

    Kim, Eun-Hwa; Johnson, Jay R.; Kim, Hyomin; Lee, Dong-Hun

    2014-05-01

    We present a method to infer heavy ion concentration ratios from EMIC wave observations that result from ionion hybrid (IIH) resonance. A key feature of the ion-ion hybrid resonance is the concentration of wave energy in a field-aligned resonant mode that exhibits linear polarization. This mode converted wave is localized at the location where the frequency of a compressional wave driver matches the IIH resonance condition, which depends sensitively on the heavy ion concentration. This dependence makes it possible to estimate the heavy ion concentration ratio. In this letter, we evaluate the absorption coefficients at the IIH resonance at Earth's geosynchronous orbit for variable concentrations of He+ and field-aligned wave numbers using a dipole magnetic field. Although wave absorption occurs for a wide range of heavy ion concentrations, it only occurs for a limited range of field-aligned wave numbers such that the IIH resonance frequency is close to, but not exactly the same as the crossover frequency. Using the wave absorption and observed EMIC waves from GOES-12 satellite, we demonstrate how this technique can be used to estimate that the He+ concentration is around 4% near L = 6.6.

  3. Overview of US heavy-ion fusion progress and plans

    SciTech Connect

    Logan, B.G.

    2004-06-01

    Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, transport, final focusing, chambers and targets for inertial fusion energy (IFE) driven by induction linac accelerators seek to provide the scientific and technical basis for the Integrated Beam Experiment (IBX), an integrated source-to-target physics experiment recently included in the list of future facilities planned by the U.S. Department of Energy. To optimize the design of IBX and future inertial fusion energy drivers, current HIF-VNL research is addressing several key issues (representative, not inclusive): gas and electron cloud effects which can exacerbate beam loss at high beam perveance and magnet aperture fill factors; ballistic neutralized and assisted-pinch focusing of neutralized heavy ion beams; limits on longitudinal compression of both neutralized and un-neutralized heavy ion bunches; and tailoring heavy ion beams for uniform target energy deposition for high energy density physics (HEDP) studies.

  4. Photon and dilepton production in high energy heavy ion collisions

    DOE PAGESBeta

    Sakaguchi, Takao

    2015-05-07

    The recent results on direct photons and dileptons in high energy heavy ion collisions, obtained particularly at RHIC and LHC are reviewed. The results are new not only in terms of the probes, but also in terms of the precision. We shall discuss the physics learned from the results.

  5. Experimental atomic physics in heavy-ion storage rings

    SciTech Connect

    Datz, S.; Andersen, L.H.; Briand, J.P.; Liesen, D.

    1987-01-01

    This paper outlines the discussion which took place at the ''round table'' on experimental atomic physics in heavy-ion storage rings. Areas of discussion are: electron-ion interactions, ion-ion collisions, precision spectroscopy of highly charged ions, beta decay into bound final states, and atomic binding energies from spectroscopy of conversion elections. 18 refs., 1 tab. (LSP)

  6. Entropy and hadrochemical composition in heavy ion collision

    SciTech Connect

    Biro, T.; Barz, H.W.; Lukacs, B.; Zimanyi, J.

    1983-06-01

    The composite particle production in a heavy ion collision is calculated in the framework of a hadrochemical model. A critical comparison is performed between the produced entropy and the observables. The entropy production during the hadrochemical processes is found to be negligible.

  7. Nonuniformity mitigation of beam illumination in heavy ion inertial fusion

    NASA Astrophysics Data System (ADS)

    Kawata, S.; Noguchi, K.; Suzuki, T.; Kurosaki, T.; Barada, D.; Ogoyski, A. I.; Zhang, W.; Xie, J.; Zhang, H.; Dai, D.

    2014-08-01

    In inertial fusion, a target DT fuel should be compressed to typically 1000 times the solid density. The target implosion nonuniformity is introduced by a driver beam’s illumination nonuniformity, for example. The target implosion should be robust against the implosion nonuniformities. In this paper, the requirement for implosion uniformity is first discussed. The implosion non-uniformity should be less than a few percent. The implosion dynamics is also briefly reviewed in heavy ion inertial fusion (HIF). Heavy ions deposit their energy inside the target energy absorber, and the energy deposition layer is rather thick, depending on the ion particle energy. Then nonuniformity mitigation mechanisms of the heavy ion beam (HIB) illumination in HIF are discussed. A density valley appears in the energy absorber, and the large-scale density valley also works as a radiation energy confinement layer, which contributes to a radiation energy smoothing. In HIF, wobbling heavy ion beam illumination was also introduced to realize a uniform implosion. The wobbling HIB axis oscillation is precisely controlled. In the wobbling HIBs’ illumination, the illumination nonuniformity oscillates in time and space on an HIF target. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs’ illumination nonuniformity by its smoothing effect on the HIB illumination nonuniformity and also by a growth mitigation effect on the Rayleigh-Taylor instability.

  8. Comments about the electromagnetic field in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    McLerran, L.; Skokov, V.

    2014-09-01

    In this article we discuss the properties of electromagnetic fields in heavy-ion collisions and consequences for observables. We address quantitatively the issue of the magnetic field lifetime in a collision including the electric and chiral magnetic conductivities. We show that for reasonable parameters, the magnetic field created by spectators in a collision is not modified by the presence of matter.

  9. Tumor Therapy with High-Energy Heavy-Ion Beams

    NASA Astrophysics Data System (ADS)

    Schardt, D.

    2001-09-01

    Heavy-ion beams offer favourable conditions for the treatment of deep-seated local tumors. The well defined range and the small lateral beam spread make it possible to deliver the dose with millimeter precision. In addition, heavy ions have an enhanced biological efficiency in the Bragg peak region which is caused by the dense ionization and the resulting reduced cellular repair rate. Furthermore, heavy ions offer the unique possibility of in-vivo range monitoring by applying Positron-Emission-Tomography (PET) techniques. Taking advantage of these clinically relevant properties, a therapy unit using 12C beams with energies of 80-430 MeV/u was constructed at GSI. The fully active beam delivery system includes a magnetic raster scan device providing a high degree of dose conformation to the target volume while healthy tissue and radiosensitive structures are spared to a maximum extent. In the framework of a clinical study 68 patients have been treated since December 1997 with promising results so far. Plans for a dedicated heavy-ion treatment center at the Radiological Clinic Heidelberg will be further pursued.

  10. Trends in Device SEE Susceptibility from Heavy Ions

    NASA Technical Reports Server (NTRS)

    Nichols, D. K.; Coss, J. R.; McCarty, K. P.; Schwartz, H. R.; Swift, G. M.; Watson, R. K.; Koga, R.; Crain, W. R.; Crawford, K. B.; Hansel, S. J.

    1995-01-01

    The sixth set of heavy ion single event effects (SEE) test data have been collected since the last IEEE publications in December issues of IEEE - Nuclear Science Transactions for 1985, 1987, 1989, 1991, and the IEEE Workshop Record, 1993. Trends in SEE susceptibility (including soft errors and latchup) for state-of- are evaluated.

  11. NSAC Recommends a Relativistic Heavy-Ion Collider.

    ERIC Educational Resources Information Center

    Physics Today, 1984

    1984-01-01

    Describes the plan submitted by the Nuclear Science Advisory Committee to the Department of Energy and National Science Foundation urging construction of an ultrarelativistic heavy-ion collider designed to accelerate nucleon beams of ions as heavy as uranium. Discusses the process of selecting the type of facility as well as siting. (JM)

  12. Update on parts SEE susceptibility from heavy ions

    NASA Astrophysics Data System (ADS)

    Nickols, D. K.; Smith, L. S.; Schwartz, H. R.; Soli, G.; Watson, K.

    1992-10-01

    Jet Propulsion Laboratory (JPL) and The Aerospace Corporation have collected a fourth set of heavy ion single event effects (SEE) test data since their last joint contributions to IEEE Transactions on Nuclear Science in December 1985, 1987, and 1989. Trends in SEE susceptibility (including soft errors and latchup) for state-of-the-art parts are displayed.

  13. Three-dimensional Model of Tissue and Heavy Ions Effects

    NASA Technical Reports Server (NTRS)

    Ponomarev, Artem L.; Sundaresan, Alamelu; Huff, Janice L.; Cucinotta, Francis A.

    2007-01-01

    A three-dimensional tissue model was incorporated into a new Monte Carlo algorithm that simulates passage of heavy ions in a tissue box . The tissue box was given as a realistic model of tissue based on confocal microscopy images. The action of heavy ions on the cellular matrix for 2- or 3-dimensional cases was simulated. Cells were modeled as a cell culture monolayer in one example, where the data were taken directly from microscopy (2-d cell matrix), and as a multi-layer obtained from confocal microscopy (3-d case). Image segmentation was used to identify cells with precise areas/volumes in an irradiated cell culture monolayer, and slices of tissue with many cell layers. The cells were then inserted into the model box of the simulated physical space pixel by pixel. In the case of modeled tissues (3-d), the tissue box had periodic boundary conditions imposed, which extrapolates the technique to macroscopic volumes of tissue. For the real tissue (3-d), specific spatial patterns for cell apoptosis and necrosis are expected. The cell patterns were modeled based on action cross sections for apoptosis and necrosis estimated from current experimental data. A spatial correlation function indicating a higher spatial concentration of damaged cells from heavy ions relative to the low-LET radiation cell damage pattern is presented. The spatial correlation effects among necrotic cells can help studying microlesions in organs, and probable effects of directionality of heavy ion radiation on epithelium and endothelium.

  14. Heavy-ion tumor therapy: Physical and radiobiological benefits

    NASA Astrophysics Data System (ADS)

    Schardt, Dieter; Elsässer, Thilo; Schulz-Ertner, Daniela

    2010-01-01

    High-energy beams of charged nuclear particles (protons and heavier ions) offer significant advantages for the treatment of deep-seated local tumors in comparison to conventional megavolt photon therapy. Their physical depth-dose distribution in tissue is characterized by a small entrance dose and a distinct maximum (Bragg peak) near the end of range with a sharp fall-off at the distal edge. Taking full advantage of the well-defined range and the small lateral beam spread, modern scanning beam systems allow delivery of the dose with millimeter precision. In addition, projectiles heavier than protons such as carbon ions exhibit an enhanced biological effectiveness in the Bragg peak region caused by the dense ionization of individual particle tracks resulting in reduced cellular repair. This makes them particularly attractive for the treatment of radio-resistant tumors localized near organs at risk. While tumor therapy with protons is a well-established treatment modality with more than 60 000 patients treated worldwide, the application of heavy ions is so far restricted to a few facilities only. Nevertheless, results of clinical phase I-II trials provide evidence that carbon-ion radiotherapy might be beneficial in several tumor entities. This article reviews the progress in heavy-ion therapy, including physical and technical developments, radiobiological studies and models, as well as radiooncological studies. As a result of the promising clinical results obtained with carbon-ion beams in the past ten years at the Heavy Ion Medical Accelerator facility (Japan) and in a pilot project at GSI Darmstadt (Germany), the plans for new clinical centers for heavy-ion or combined proton and heavy-ion therapy have recently received a substantial boost.

  15. Cosmic heavy ion tracks in mesoscopic biological test objects

    NASA Technical Reports Server (NTRS)

    Facius, R.

    1994-01-01

    Since more than 20 years ago, when the National Academy of Sciences and the National Research Council of the U.S.A. released their report on 'HZE particle effects in manned spaced flight', it has been emphasized how difficult - if not even impossible - it is to assess their radiobiological impact on man from conventional studies where biological test organisms are stochastically exposed to 'large' fluences of heavy ions. An alternative, competing approach had been realized in the BIOSTACK experiments, where the effects of single cosmic as well as accelerator - heavy ions on individual biological test organisms could be investigated. Although presented from the beginning as the preferable approach for terrestrial investigations with accelerator heavy ions too ('The BIOSTACK as an approach to high LET radiation research'), only recently this insight is gaining more widespread recognition. In space flight experiments, additional constraints imposed by the infrastructure of the vehicle or satellite further impede such investigations. Restrictions concern the physical detector systems needed for the registration of the cosmic heavy ions' trajectories as well as the biological systems eligible as test organisms. Such optimized procedures and techniques were developed for the investigations on chromosome aberrations induced by cosmic heavy ions in cells of the stem meristem of lettuce seeds (Lactuca sativa) and for the investigation of the radiobiological response of Wolffia arriza, which is the smallest flowering (water) plant. The biological effects were studied by the coworkers of the Russian Institute of Biomedical Problems (IBMP) which in cooperation with the European Space Agency ESA organized the exposure in the Biosatellites of the Cosmos series. Since biological investigations and physical measurements of particle tracks had to be performed in laboratories widely separated, the preferred fixed contact between biological test objects and the particle detectors

  16. Heavy-ion tumor therapy: Physical and radiobiological benefits

    SciTech Connect

    Schardt, Dieter; Elsaesser, Thilo; Schulz-Ertner, Daniela

    2010-01-15

    High-energy beams of charged nuclear particles (protons and heavier ions) offer significant advantages for the treatment of deep-seated local tumors in comparison to conventional megavolt photon therapy. Their physical depth-dose distribution in tissue is characterized by a small entrance dose and a distinct maximum (Bragg peak) near the end of range with a sharp fall-off at the distal edge. Taking full advantage of the well-defined range and the small lateral beam spread, modern scanning beam systems allow delivery of the dose with millimeter precision. In addition, projectiles heavier than protons such as carbon ions exhibit an enhanced biological effectiveness in the Bragg peak region caused by the dense ionization of individual particle tracks resulting in reduced cellular repair. This makes them particularly attractive for the treatment of radio-resistant tumors localized near organs at risk. While tumor therapy with protons is a well-established treatment modality with more than 60 000 patients treated worldwide, the application of heavy ions is so far restricted to a few facilities only. Nevertheless, results of clinical phase I-II trials provide evidence that carbon-ion radiotherapy might be beneficial in several tumor entities. This article reviews the progress in heavy-ion therapy, including physical and technical developments, radiobiological studies and models, as well as radiooncological studies. As a result of the promising clinical results obtained with carbon-ion beams in the past ten years at the Heavy Ion Medical Accelerator facility (Japan) and in a pilot project at GSI Darmstadt (Germany), the plans for new clinical centers for heavy-ion or combined proton and heavy-ion therapy have recently received a substantial boost.

  17. Heavy-ion radiation induced bystander effect in mice

    NASA Astrophysics Data System (ADS)

    Liang, Shujian; Sun, Yeqing; Zhang, Meng; Wang, Wei; Cui, Changna

    2012-07-01

    Radiation-induced bystander effect is defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, Low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic, metabolomics and proteomics play significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male mice head were exposed to 2000mGy dose of 12C heavy-ion radiation and the distant organ liver was detected on 1h, 6h, 12h and 24h after radiation, respectively. MSAP was used to monitor the level of polymorphic DNA methylation changes. The results show that heavy-ion irradiate mouse head can induce liver DNA methylation changes significantly. The percent of DNA methylation changes are time-dependent and highest at 6h after radiation. We also prove that the hypo-methylation changes on 1h and 6h after irradiation. But the expression level of DNA methyltransferase DNMT3a is not changed. UPLC/Synapt HDMS G2 was employed to detect the proteomics of bystander liver 1h after irradiation. 64 proteins are found significantly different between treatment and control group. GO process show that six of 64 which were unique in irradiation group are associated with apoptosis and DNA damage response. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

  18. Cosmic heavy ion tracks in mesoscopic biological test objects

    SciTech Connect

    Facius, R.

    1994-12-31

    Since more than 20 years ago, when the National Academy of Sciences and the National Research Council of the U.S.A. released their report on `HZE particle effects in manned spaced flight`, it has been emphasized how difficult - if not even impossible - it is to assess their radiobiological impact on man from conventional studies where biological test organisms are stochastically exposed to `large` fluences of heavy ions. An alternative, competing approach had been realized in the BIOSTACK experiments, where the effects of single cosmic as well as accelerator - heavy ions on individual biological test organisms could be investigated. Although presented from the beginning as the preferable approach for terrestrial investigations with accelerator heavy ions too (`The BIOSTACK as an approach to high LET radiation research`), only recently this insight is gaining more widespread recognition. In space flight experiments, additional constraints imposed by the infrastructure of the vehicle or satellite further impede such investigations. Restrictions concern the physical detector systems needed for the registration of the cosmic heavy ions` trajectories as well as the biological systems eligible as test organisms. Such optimized procedures and techniques were developed for the investigations on chromosome aberrations induced by cosmic heavy ions in cells of the stem meristem of lettuce seeds (Lactuca sativa) and for the investigation of the radiobiological response of Wolffia arriza, which is the smallest flowering (water) plant. The biological effects were studied by the coworkers of the Russian Institute of Biomedical Problems (IBMP) which in cooperation with the European Space Agency ESA organized the exposure in the Biosatellites of the Cosmos series.

  19. Baryon distributions in heavy ion collisions at AGS energies: An experimental overview

    SciTech Connect

    Videbaek, F.

    1993-06-01

    Data on rapidity distributions of protons from the three AGS experiments E-814, E-810 and E-802 are compared on a common base to enlarge the rapidity coverage. Together they provide a unique opportunity to study the proton distributions in relativistic heavy ion reactions over the full rapidity range. Systematics of the rapidity density distributions are presented as function of centrality and mass of colliding system. Considerable stopping is achieved for the heaviest system studied, Au+Au, thus giving the means to study high-density effects in nuclear matter.

  20. Baryon distributions in heavy ion collisions at AGS energies: An experimental overview

    SciTech Connect

    Videbaek, F.

    1993-01-01

    Data on rapidity distributions of protons from the three AGS experiments E-814, E-810 and E-802 are compared on a common base to enlarge the rapidity coverage. Together they provide a unique opportunity to study the proton distributions in relativistic heavy ion reactions over the full rapidity range. Systematics of the rapidity density distributions are presented as function of centrality and mass of colliding system. Considerable stopping is achieved for the heaviest system studied, Au+Au, thus giving the means to study high-density effects in nuclear matter.

  1. The heavy ion composition in 3HE-rich solar flares

    NASA Technical Reports Server (NTRS)

    Mason, G. M.; Reames, D. V.; Hovestadt, D.; Vonrosenvinge, T. T.

    1985-01-01

    The 3He-rich flares show a tendency to be enriched in heavy ions, and that this enrichment covers the charge range through Fe. The discovery of this association was responsible, in part, for the discarding of 3He enrichment models which involved spallation or thermonuclear reactions, since such models were unable to produce heavy nuclei enhancement. Results of a survey of heavy nucleus abundances observed in 66 3He-rich flares which occurred over the period October 1978 to June 1982 are presented.

  2. Vorticity and hydrodynamic helicity in heavy-ion collisions in the hadron-string dynamics model

    NASA Astrophysics Data System (ADS)

    Teryaev, Oleg; Usubov, Rahim

    2015-07-01

    The hydrodynamic helicity separation effect in noncentral heavy-ion collisions is investigated using the hadron-string dynamics (HSD) model. Computer simulations are done to calculate velocity and hydrodynamic helicity on a mesh in a small volume around the center of the reaction. The time dependence of hydrodynamic helicity is observed for various impact parameters and different calculation methods. Comparison with a similar earlier work is carried out. A new quantity related to jet handedness is used to probe for p -odd effects in the final state.

  3. Narrow Resonances in Light Heavy-Ion Collisions: Formation and Decay

    SciTech Connect

    Haas, F.; Courtin, S.; Lebhertz, D.; Salsac, M.-D.

    2009-03-04

    Resonances in light heavy-ion collisions have been observed in systems with a small number of open channels. Very narrow resonances have been reported in the {sup 24}Mg+{sup 24}Mg and {sup 12}C+{sup 12}C cases for which the results of recent experiments on their decay modes will be presented. Special emphasis will be given to the {sup 12}C+{sup 12}C reaction where weak absorption allows the observation of resonant and refractive effects over a large bombarding energy range. The nature of recently observed sub-coulomb resonances will also be raised.

  4. Coulomb effects on pions produced in heavy-ion reactions

    SciTech Connect

    Sullivan, J.P.

    1981-11-01

    Double differential cross sections for the production of ..pi../sup +/ and ..pi../sup -/ near the velocity of the incident beam for pion lab angles less than 40 degrees are presented. The experimental apparatus and the techniques are discussed. Beams of /sup 20/Ne with E/A from 80 to 655 MeV and /sup 40/Ar with E/A = 535 MeV incident on Be, C, NaF, KC1, Cu, and U targets were used. A sharp peak in the ..pi../sup -/ spectrum and a depression in the ..pi../sup +/ spectrum were observed at zero degrees near the incident beam velocity. The effect is explained in terms of Coulomb interactions between the pions and fragments of the incident beam. Least squares fits to the data using the Coulomb correction formulas of Gyulassy and Kauffman and an effective projectile fragment charge are made. The relationship between these data and previously measured pion production and projectile fragmentation data is discussed. The data are also compared to some theoretical models. A simple expression is given for the differential cross section as a function of the projectile mass, target mass, and beam energy.

  5. Effects of Coulomb quadrupole excitation in heavy-ion reactions

    NASA Astrophysics Data System (ADS)

    Cheoun, Myung-Ki; Choi, K. S.; Kim, K. S.; Kim, T. H.; So, W. Y.

    2016-09-01

    For 12C + 184W, 18O + 184W, and 20Ne + 208Pb systems, we investigate the suppression of the ratios P E = σ el/ σ RU by using the Coulomb quadrupole excitation (CQE) potentials. In order to explain the effect of the CQE potentials, we first use a well-known Love's CQE potential, and reproduce the experimental P E data well by using this potential. We also introduce a simple CQE potential written as W CQE( r) = - W P / r n , which is much simpler than the conventional Love's potential, to investigate the suppression of the P E ratios. Using this potential, we perform a χ2 analysis to find the adjustable parameter n, then, we find that the best fit parameters n ≈ 5 is close to the lowest order term, 1/ r 5. Consequently, we find that using the simple CQE potential explains the experimental P E data and that the ratio P E depends on the n values sensitively.

  6. Studies of complex fragment emission in heavy ion reactions

    SciTech Connect

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

    1991-09-04

    This report discusses the following topics: High energy photon production in a HI collision; the mechanism for the disassembly of excited {sup 16}O projectiles into four alpha particles; the disassembly of excited {sup 28}Si projectiles; large pre-fission multiplicities from temperature; dependent friction and fission barriers; multiplicity correlations; molecular beam induced fusion; dwarf ball and wall; mini wall; and computer and local data acquisition systems.

  7. EDITORIAL: Focus on Heavy Ions in Biophysics and Medical Physics FOCUS ON HEAVY IONS IN BIOPHYSICS AND MEDICAL PHYSICS

    NASA Astrophysics Data System (ADS)

    Durante, Marco

    2008-07-01

    Interest in energetic heavy ions is rapidly increasing in the field of biomedicine. Heavy ions are normally excluded from radiation protection, because they are not normally experienced by humans on Earth. However, knowledge of heavy ion biophysics is necessary in two fields: charged particle cancer therapy (hadrontherapy), and radiation protection in space missions. The possibility to cure tumours using accelerated heavy charged particles was first tested in Berkeley in the sixties, but results were not satisfactory. However, about 15 years ago therapy with carbon ions was resumed first in Japan and then in Europe. Heavy ions are preferable to photons for both physical and biological characteristics: the Bragg peak and limited lateral diffusion ensure a conformal dose distribution, while the high relative biological effectiveness and low oxygen enhancement ration in the Bragg peak region make the beam very effective in treating radioresistant and hypoxic tumours. Recent results coming from the National Institute of Radiological Sciences in Chiba (see the paper by Dr Tsujii and co-workers in this issue) and GSI (Germany) provide strong clinical evidence that heavy ions are indeed an extremely effective weapon in the fight against cancer. However, more research is needed in the field, especially on optimization of the treatment planning and risk of late effects in normal tissue, including secondary cancers. On the other hand, high-energy heavy ions are present in galactic cosmic radiation and, although they are rare as compared to protons, they give a major contribution in terms of equivalent dose to the crews of manned space exploratory-class missions. Exploration of the Solar System is now the main goal of the space program, and the risk caused by exposure to galactic cosmic radiation is considered a serious hindrance toward this goal, because of the high uncertainty on late effects of energetic heavy nuclei, and the lack of effective countermeasures. Risks

  8. Meson interferometry in relativistic heavy ion collisions

    SciTech Connect

    Not Available

    1993-05-01

    This report contains discussions on the following topics: Recent HBT results form CERN experiment NA44; interferometry results from E802/E859/E866; recent results on two particle correlations from E814; source sizes from CERN data; intermittency and interferometry; Bose-Einstein correlations in 200A GeV S+Au collisions; HBT correlations at STAR; HBT interferometry with PHENIX; HBT calculations from ARC; three pion correlations; and pion correlations in proton-induced reactions.

  9. Diffusion with chemical reaction: An attempt to explain number density anomalies in experiments involving alkali vapor

    NASA Technical Reports Server (NTRS)

    Snow, W. L.

    1974-01-01

    The mutual diffusion of two reacting gases is examined which takes place in a bath of inert gas atoms. Solutions are obtained between concentric spheres, each sphere acting as a source for one of the reactants. The calculational model is used to illustrate severe number density gradients observed in absorption experiments with alkali vapor. Severe gradients result when sq root k/D R is approximately 5 where k, D, and R are respectively the second order rate constant, the multicomponent diffusion constant, and the geometrical dimension of the experiment.

  10. Remarkable optical-potential systematics for lighter heavy ions

    SciTech Connect

    Brandan, M.E.; McVoy, K.W.

    1997-03-01

    Nuclear rainbows, which appear in the elastic scattering angular distributions for certain combinations of lighter heavy ions like {sup 12}C+{sup 12}C and {sup 16}O+{sup 16}O, uniquely determine the major features of the optical potentials for these systems. These features are conveniently summarized by the central depth of the real part of the potential, V(r=0){approximately}100{minus}300 MeV, and by the ratio of imaginary to real parts of the potential, W(r)/V(r), found to be {lt}1 for both small and large r (internal and far-tail transparency), but {approx}1 in the surface region. The resulting maximum in W/V, which is found over the entire energy range 6 MeV {approx_lt}E{sub L}/A{approx_lt}100 MeV, appears to correlate with the peripheral reactions that occur in this energy range. At higher energies the data available indicate that the far-surface region is no longer transparent. Rather, W{approx}V there, suggesting the dominance of nuclear knockout reactions in the far tail. The knockout mode of inelasticity is the one described by the double-Glauber approximation, and W(r){approx}V(r) agrees with the Glauber prediction in the high-energy range. This suggests that the double-Glauber prediction begins to be accurate in the low-density tail of the A{sub 1}+A{sub 2} interaction around E{sub L}/A{approx}100 MeV and that its failure for the higher-density interior may provide a means of investigating the density dependence of Pauli blocking on NN scattering in the nuclear medium. By way of contrast, systems like {sup 20}Ne+{sup 12}C and {sup 14}N+{sup 12}C, which do not exhibit rainbows, have distinctly more absorptive potentials and do not follow the above systematics. This suggests that the imaginary part of the optical potential reflects the shell structure of the target and/or projectile in important ways, and so will not be easy to calculate from an infinite-matter many-body approach. {copyright} {ital 1996} {ital The American Physical Society}

  11. Heavy Ion Collisions at the LHC - Last Call for Predictions

    SciTech Connect

    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

    2008-02-25

    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

  12. Heavy ion beam propagation through a gas-filled chamber for inertial confinement fusion

    SciTech Connect

    Barboza, N.O.

    1996-10-01

    The work presented here evaluates the dynamics of a beam of heavy ions propagating through a chamber filled with gas. The motivation for this research stems from the possibility of using heavy ion beams as a driver in inertial confinement fusion reactors for the purpose of generating electricity. Such a study is important in determining the constraints on the beam which limit its focus to the small radius necessary for the ignition of thermonuclear microexplosions which are the source of fusion energy. Nuclear fusion is the process of combining light nuclei to form heavier ones. One possible fusion reaction combines two isotopes of hydrogen, deuterium and tritium, to form an alpha particle and a neutron, with an accompanying release of {approximately}17.6 MeV of energy. Generating electricity from fusion requires that we create such reactions in an efficient and controlled fashion, and harness the resulting energy. In the inertial confinement fusion (ICF) approach to energy production, a small spherical target, a few millimeters in radius, of deuterium and tritium fuel is compressed so that the density and temperature of the fuel are high enough, {approximately}200 g/cm{sup 3} and {approximately}20 keV, that a substantial number of fusion reactions occur; the pellet microexplosion typically releases {approximately}350 MJ of energy in optimized power plant scenarios.

  13. Cathodoluminescence microscopy and petrographic image analysis of aggregates in concrete pavements affected by alkali-silica reaction

    SciTech Connect

    Stastna, A.; Sachlova, S.; Pertold, Z.; Prikryl, R.; Leichmann, J.

    2012-03-15

    Various microscopic techniques (cathodoluminescence, polarizing and electron microscopy) were combined with image analysis with the aim to determine a) the modal composition and degradation features within concrete, and b) the petrographic characteristics and the geological types (rocks, and their provenance) of the aggregates. Concrete samples were taken from five different portions of Highway Nos. D1, D11, and D5 (the Czech Republic). Coarse and fine aggregates were found to be primarily composed of volcanic, plutonic, metamorphic and sedimentary rocks, as well as of quartz and feldspar aggregates of variable origins. The alkali-silica reaction was observed to be the main degradation mechanism, based upon the presence of microcracks and alkali-silica gels in the concrete. Use of cathodoluminescence enabled the identification of the source materials of the quartz aggregates, based upon their CL characteristics (i.e., color, intensity, microfractures, deformation, and zoning), which is difficult to distinguish only employing polarizing and electron microscopy. - Highlights: Black-Right-Pointing-Pointer ASR in concrete pavements on the Highways Nos. D1, D5 and D11 (Czech Republic). Black-Right-Pointing-Pointer Cathodoluminescence was combined with various microscopic techniques and image analysis. Black-Right-Pointing-Pointer ASR was attributed to aggregates. Black-Right-Pointing-Pointer Source materials of aggregates were identified based on cathodoluminescence characteristics. Black-Right-Pointing-Pointer Quartz comes from different volcanic, plutonic and metamorphic parent rocks.

  14. Nuclear research with heavy ions. Annual progress report. January 1, 1980-December 31, 1980

    SciTech Connect

    Kaplan, M.

    1980-10-01

    The program of research is oriented towards experimental studies of the interactions between heavy ions and complex nuclei. These interactions are probed by detailed measurements of light-charged-particle emission using counter telescopes for atomic number and mass number identification. Singles measurements of the charged-particle energy spectra and angular distributions, together with coincidence correlations with heavy nuclear-reaction fragments, provide insight into the contributing reaction mechanisms. The application of the statistical model to the appropriate experimental data allows the determination of parameters necessary to calibrate the theory, and gives indications of dynamical control vs. equilibrium in the several degrees of freedom associated with the nuclear collisions. A large body of data are presented and discussed for /sup 40/Ar reactions with /sup 116/Sn, /sup 154/Sm, /sup 164/Dy, and /sup 197/Au targets. Complete results are also given for twelve reactions which produce /sup 194/Hg compound nuclei at several excitation energies.

  15. Studies in High Current Density Ion Sources for Heavy Ion FusionApplications

    SciTech Connect

    Chacon-Golcher, E.

    2002-06-01

    This dissertation develops diverse research on small (diameter {approx} few mm), high current density (J {approx} several tens of mA/cm{sup 2}) heavy ion sources. The research has been developed in the context of a programmatic interest within the Heavy Ion Fusion (HIF) Program to explore alternative architectures in the beam injection systems that use the merging of small, bright beams. An ion gun was designed and built for these experiments. Results of average current density yield () at different operating conditions are presented for K{sup +} and Cs{sup +} contact ionization sources and potassium aluminum silicate sources. Maximum values for a K{sup +} beam of {approx}90 mA/cm{sup 2} were observed in 2.3 {micro}s pulses. Measurements of beam intensity profiles and emittances are included. Measurements of neutral particle desorption are presented at different operating conditions which lead to a better understanding of the underlying atomic diffusion processes that determine the lifetime of the emitter. Estimates of diffusion times consistent with measurements are presented, as well as estimates of maximum repetition rates achievable. Diverse studies performed on the composition and preparation of alkali aluminosilicate ion sources are also presented. In addition, this work includes preliminary work carried out exploring the viability of an argon plasma ion source and a bismuth metal vapor vacuum arc (MEVVA) ion source. For the former ion source, fast rise-times ({approx} 1 {micro}s), high current densities ({approx} 100 mA/cm{sup 2}) and low operating pressures (< 2 mtorr) were verified. For the latter, high but acceptable levels of beam emittance were measured ({var_epsilon}{sub n} {le} 0.006 {pi} mm {center_dot} mrad) although measured currents differed from the desired ones (I {approx} 5mA) by about a factor of 10.

  16. Antiradiation Vaccine: Technology Development- Radiation Tolerance,Prophylaxis, Prevention And Treatment Of Clinical Presentation After Heavy Ion Irradiation.

    NASA Astrophysics Data System (ADS)

    Popov, Dmitri; Maliev, Slava; Jones, Jeffrey

    Introduction: Research in the field of biological effects of heavy charged particles is necessary for both heavy-ion therapy (hadrontherapy) and protection from the exposure to galactic cosmic radiation in long-term manned space missions.[Durante M. 2004] In future crew of long-term manned missions could operate in exremely high hadronic radiation areas of space and will not survive without effective radiation protection. An Antiradiation Vaccine (AV) must be an important part of a countermeasures regimen for efficient radiation protection purposes of austronauts-cosmonauts-taukonauts: immune-prophylaxis and immune-therapy of acute radiation toxic syndromes developed after heavy ion irradiation. New technology developed (AV) for the purposes of radiological protection and improvement of radiation tolerance and it is quite important to create protective immune active status which prevent toxic reactions inside a human body irradiated by high energy hadrons.[Maliev V. et al. 2006, Popov D. et al.2008]. High energy hadrons produce a variety of secondary particles which play an important role in the energy deposition process, and characterise their radiation qualities [Sato T. et al. 2003] Antiradiation Vaccine with specific immune-prophylaxis by an anti-radiation vaccine should be an important part of medical management for long term space missions. Methods and experiments: 1. Antiradiation vaccine preparation standard, mixture of toxoid form of Radiation Toxins [SRD-group] which include Cerebrovascular RT Neurotoxin, Cardiovascular RT Neurotoxin, Gastrointestinal RT Neurotoxin, Hematopoietic RT Hematotoxin. Radiation Toxins of Radiation Determinant Group isolated from the central lymph of gamma-irradiated animals with Cerebrovascular, Cardiovascular, Gastro-intestinal, Hematopoietic forms of ARS. Devices for radiation are "Panorama", "Puma". 2. Heavy ion exposure was accomplished at Department of Research Institute of Nuclear Physics, Dubna, Russia. The heavy ions

  17. Nonresonant interaction of heavy ions with electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Berchem, J.; Gendrin, R.

    1985-01-01

    The motion of a heavy ion in the presence of an intense ultralow-frequency electromagnetic wave propagating along the dc magnetic field is analyzed. Starting from the basic equations of motion and from their associated two invariants, the heavy ion velocity-space trajectories are drawn. It is shown that after a certain time, particles whose initial phase angles are randomly distributed tend to bunch together, provided that the wave intensity b-sub-1 is sufficiently large. The importance of these results for the interpretation of the recently observed acceleration of singly charged He ions in conjunction with the occurrence of large-amplitude ion cyclotron waves in the equatorial magnetosphere is discussed.

  18. Activation of accelerator construction materials by heavy ions

    NASA Astrophysics Data System (ADS)

    Katrík, P.; Mustafin, E.; Hoffmann, D. H. H.; Pavlovič, M.; Strašík, I.

    2015-12-01

    Activation data for an aluminum target irradiated by 200 MeV/u 238U ion beam are presented in the paper. The target was irradiated in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. The purpose of the experiment was to study the role of primary particles, projectile fragments, and target fragments in the activation process using the depth profiling of residual activity. The study brought information on which particles contribute dominantly to the target activation. The experimental data were compared with the Monte Carlo simulations by the FLUKA 2011.2c.0 code. This study is a part of a research program devoted to activation of accelerator construction materials by high-energy (⩾200 MeV/u) heavy ions at GSI Darmstadt. The experimental data are needed to validate the computer codes used for simulation of interaction of swift heavy ions with matter.

  19. Development of heavy-ion radiotherapy technology with HIMAC

    NASA Astrophysics Data System (ADS)

    Noda, Koji

    2016-09-01

    Since 1994, HIMAC has carried out clinical studies and treatments for more than 9000 cancer patients with carbon-ion beams. During the first decade of the HIMAC study, a single beam-wobbling method, adopted as the HIMAC beam-delivery technique, was improved for treatments of moving tumors and for obtaining more conformal dose distribution. During the second decade, a pencil-beam 3D scanning method has been developed toward an “adaptive cancer treatment” for treatments of both static and moving tumors. A new treatment research facility was constructed with HIMAC in order to verify the developed 3D scanning technology through a clinical study that has been successfully conducted since 2011. As the next stage, a compact heavy-ion rotating gantry with a superconducting technology has been developed for the more accurate and shorter-course treatments. The twenty-year development of the heavy-ion radiotherapy technologies including accelerator technologies with HIMAC is reviewed.

  20. Solutions to heavy ion induced avalanche burnout in power devices

    NASA Astrophysics Data System (ADS)

    Wrobel, Theodore F.; Beutler, David E.

    1992-12-01

    A review of normal breakdown and current induced avalanche (CIA) breakdown mechanisms in silicon power transistors is presented. The applicability of the CIA model to heavy ion induced burnout is shown, and solutions to CIA in silicon power semiconductors are given. It is noted that solving the problem of CIA burnout in npn bipolar and n-channel DMOS devices is, at best, difficult. Several techniques of hardening these devices to the effects of heavy ion, dose-rate induced failure, and any other condition producing CIA are discussed. The most effective techniques are those that minimize the emitter current injection by reducing the emitter injection efficiency or making the parasitic bipolar more difficult to turn on. However, it is believed that the simplest solution to the problem is to use pnp bipolar and p-channel DMOS devices whenever possible.

  1. Uniform fuel target implosion in heavy ion inertial fusion

    NASA Astrophysics Data System (ADS)

    Kawata, S.; Karino, T.; Kondo, S.; Iinuma, T.; Barada, D.; Ma, Y. Y.; Ogoyski, A. I.

    2016-05-01

    For a steady operation of a fusion power plant the target implosion should be robust against the implosion non-uniformities. In this paper the non-uniformity mitigation mechanisms in the heavy ion beam (HIB) illumination are discussed in heavy ion inertial fusion (HIF). A density valley appears in the energy absorber, and the large-scale density valley also works as a radiation energy confinement layer, which contributes to the radiation energy smoothing for the HIB illumination non-uniformity. The large density-gradient scale, which is typically ∼500μm in HIF targets, also contributes to a reduction of the Rayleigh- Taylor instability growth rate. In HIF a wobbling HIBs illumination would also reduce the Rayleigh-Taylor instability growth and to realize a uniform implosion.

  2. Clustered DNA damage induced by heavy ion particles.

    PubMed

    Terato, Hiroaki; Ide, Hiroshi

    2004-12-01

    Clustered DNA damage (locally multiply damaged site) is thought to be a critical lesion caused by ionizing radiation, and high LET radiation such as heavy ion particles is believed to produce high yields of such damage. Since heavy ion particles are major components of ionizing radiation in a space environment, it is important to clarify the chemical nature and biological consequences of clustered DNA damage and its relationship to the health effects of exposure to high LET particles in humans. The concept of clustered DNA damage emerged around 1980, but only recently has become the subject of experimental studies. In this article, we review methods used to detect clustered DNA damage, and the current status of our understanding of the chemical nature and repair of clustered DNA damage. PMID:15858387

  3. Advances in U.S. Heavy Ion Fusion Science

    SciTech Connect

    Barnard, JJ; Logan, B.G.; Barnard, J.J.; Bieniosek, F.M.; Cohen, R.H.; Coleman, J.E.; Davidson, R.C.; Efthimion, P.C.; Friedman, A.; Gilson, E.P.; Grisham, L.R.; Grote, D.P.; Henestroza, E.; Kaganovich, I.D.; Kireeff-Covo, M.; Lee, E.P.; Leitner, M.A.; Lund, S.M.; Molvik, A.W.; Ni, P.; Perkins, L.J.; Qin, H.; Roy, P.K.; Sefkow, A.B.; Seidl, P.A.; Startsev, E.A.; Waldron, W.L.

    2007-09-03

    During the past two years, the US heavy ion fusion science program has made significant experimental and theoretical progress in simultaneous transverse and longitudinal beam compression, ion-beam-driven warm dense matter targets, high-brightness beam transport, advanced theory and numerical simulations, and heavy ion target physics for fusion. First experiments combining radial and longitudinal compression {pi} of intense ion beams propagating through background plasma resulted in on-axis beam densities increased by 700X at the focal plane. With further improvements planned in 2008, these results enable initial ion beam target experiments in warm dense matter to begin next year. They are assessing how these new techniques apply to higher-gain direct-drive targets for inertial fusion energy.

  4. Advances in U.S. Heavy Ion Fusion Science

    SciTech Connect

    Logan, B.G.; Barnard, J.J.; Bieniosek, F.M.; Cohen, R.H.; Coleman, J.E.; Davidson, R.C.; Efthimion, P.C.; Friedman, A.; Gilson, E.P.; Grisham, L.R.; Grote, D.P.; Henestroza, E.; Kaganovich, I.D.; Kireeff-Covo, M.; Lee, E.P.; Leitner, M.A.; Lund, S.M.; Molvik, A.W.; Ni, P.; Perkins, L. J.; Qin, H.; Roy, P.K.; Sefkow, A.B.; Seidl, P.A.; Startsev, E.A.; Waldron, W.L.

    2007-09-01

    During the past two years, the US heavy ion fusion science program has made significant experimental and theoretical progress in simultaneous transverse and longitudinal beam compression, ion-beam-driven warm dense matter targets, high-brightness beam transport, advanced theory and numerical simulations, and heavy ion target physics for fusion. First experiments combining radial and longitudinal compression {pi} of intense ion beams propagating through background plasma resulted in on-axis beam densities increased by 700X at the focal plane. With further improvements planned in 2008, these results enable initial ion beam target experiments in warm dense matter to begin next year. They are assessing how these new techniques apply to higher-gain direct-drive targets for inertial fusion energy.

  5. Dosimetry of heavy ions by use of CCD detectors

    NASA Technical Reports Server (NTRS)

    Schott, J. U.

    1994-01-01

    The design and the atomic composition of Charge Coupled Devices (CCD's) make them unique for investigations of single energetic particle events. As detector system for ionizing particles they detect single particles with local resolution and near real time particle tracking. In combination with its properties as optical sensor, particle transversals of single particles are to be correlated to any objects attached to the light sensitive surface of the sensor by simple imaging of their shadow and subsequent image analysis of both, optical image and particle effects, observed in affected pixels. With biological objects it is possible for the first time to investigate effects of single heavy ions in tissue or extinguished organs of metabolizing (i.e. moving) systems with a local resolution better than 15 microns. Calibration data for particle detection in CCD's are presented for low energetic protons and heavy ions.

  6. Factorization, the Glasma and the Ridge in heavy ion collisions

    SciTech Connect

    Venugopalan, Raju

    2008-10-13

    High energy heavy ion collisions can be efficiently described as the collision of two sheets of Color Glass Condensate. The dynamics of the collision can be studied ab initio in a systematic effective field theory approach. This requires factorization theorems that separate the initial state evolution of the wave functions with energy from the final state interactions that produce matter with high energy densities called the Glasma. We discuss how this matter is formed, its remarkable properties and its relevance for understanding thermalization of the Quark Gluon Plasma in heavy ion collisions. Long range rapidity correlations in the collision that have a remarkable ridge like structure may allow us to probe early times in the collision and infer directly the properties of the Glasma.

  7. High-brightness heavy-ion injector experiments

    NASA Astrophysics Data System (ADS)

    Westenskow, G. A.; Kwan, J. W.; Grote, D. P.; Bieniosek, F.

    2007-07-01

    To provide a compact high-brightness heavy-ion beam source for Heavy Ion Fusion, we have performed experiments to study a proposed merging beamlet approach for the injector. We used an RF plasma source to produce the initial beamlets. An array of converging beamlets was used to produce a beam with the envelope radius, convergence, and ellipticity matched to an electrostatic quadrupole channel. Experimental results were in good quantitative agreement with simulation and have demonstrated the feasibility of this concept. The size of a driver-scale injector system using this approach will be several times smaller than one designed using traditional single large-aperture beams. The success of this experiment has possible significant economical and technical impacts on the architecture of HIF drivers.

  8. Multiple beam induction accelerators for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Seidl, Peter A.; Barnard, John J.; Faltens, Andris; Friedman, Alex; Waldron, William L.

    2014-01-01

    Induction accelerators are appealing for heavy-ion driven inertial fusion energy (HIF) because of their high efficiency and their demonstrated capability to accelerate high beam current (≥10 kA in some applications). For the HIF application, accomplishments and challenges are summarized. HIF research and development has demonstrated the production of single ion beams with the required emittance, current, and energy suitable for injection into an induction linear accelerator. Driver scale beams have been transported in quadrupole channels of the order of 10% of the number of quadrupoles of a driver. We review the design and operation of induction accelerators and the relevant aspects of their use as drivers for HIF. We describe intermediate research steps that would provide the basis for a heavy-ion research facility capable of heating matter to fusion relevant temperatures and densities, and also to test and demonstrate an accelerator architecture that scales well to a fusion power plant.

  9. Anti-biofilm activity of Fe heavy ion irradiated polycarbonate

    NASA Astrophysics Data System (ADS)

    Joshi, R. P.; Hareesh, K.; Bankar, A.; Sanjeev, Ganesh; Asokan, K.; Kanjilal, D.; Dahiwale, S. S.; Bhoraskar, V. N.; Dhole, S. D.

    2016-10-01

    Polycarbonate (PC) polymers were investigated before and after high energy heavy ion irradiation for anti-bacterial properties. These PC films were irradiated by Fe heavy ions with two energies, viz, 60 and 120 MeV, at different fluences in the range from 1 × 1011 ions/cm2 to 1 × 1013 ions/cm2. UV-Visible spectroscopic results showed optical band gap decreased with increase in ion fluences due to chain scission mainly at carbonyl group of PC which is also corroborated by Fourier transform infrared spectroscopic results. X-ray diffractogram results showed decrease in crystallinity of PC after irradiation which leads to decrease in molecular weight. This is confirmed by rheological studies and also by differential scanning calorimetric results. The irradiated PC samples showed modification in their surfaces prevents biofilm formation of human pathogen, Salmonella typhi.

  10. Compact High-Current Heavy-Ion Injector

    SciTech Connect

    Westenskow, G A; Grote, D P; Kwan, J W; Bieniosek, F

    2006-04-13

    To provide a compact high-brightness heavy-ion beam source for Heavy Ion Fusion (HIF), we have been experimenting with merging multi-beamlets in an injector which uses an RF plasma source. An array of converging beamlets was use to produce a beam with the envelope radius, convergence, and ellipticity matched to an electrostatic quadrupole (ESQ) channel. Experimental results were in good quantitative agreement with simulation and have demonstrated the feasibility of this concept. The size of a driver-scale injector system using this approach will be several times smaller than one designed using traditional single large-aperture beams. The success of this experiment has possible significant economical and technical impacts on the architecture of HIF drivers.

  11. On compositional variations of heavy ions during solar particle events

    NASA Technical Reports Server (NTRS)

    Klecker, B.; Scholer, M.; Hovestadt, D.; Fan, C. Y.; Fisk, L. A.; Gloeckler, G.; Ipavich, F. M.; Ogallagher, J. J.

    1981-01-01

    Intensity-time profiles of protons, alpha particles, and heavy ions (C, O, Fe) in the MeV/nucleon energy range have been analyzed for one solar particle event following the solar flare on September 23, 1978. The data have been obtained with the wide angle double dE/dx-E sensor of the Max-Planck-Institut/University of Maryland experiment onboard ISEE-3. Time variations in the iron to helium ratio of up to 2 orders of magnitude and a significant variation of the O/He ratio during this event have been found, whereas the C/O-ratio at the same energy/nucleon appears to be time independent. The influence of a rigidity dependent mean free path in interplanetary space and of rigidity dependent coronal propagation on heavy ion ratios during solar particle events was investigated.

  12. The magnet system of the Relativistic Heavy Ion Collider (RHIC)

    SciTech Connect

    Greene, A.; Anerella, M.; Cozzolino, J.

    1995-07-01

    The Relativistic Heavy Ion Collider now under construction at Brookhaven National Laboratory (BNL) is a colliding ring accelerator to be completed in 1999. Through collisions of heavy ions it is hoped to observe the creation of matter at extremely high temperatures and densities, similar to what may have occurred in the original ``Big Bang.`` The collider rings will consist of 1740 superconducting magnet elements. Some of elements are being manufactured by industrial partners (Northrop Grumman and Everson Electric). Others are being constructed or assembled at BNL. A description is given of the magnet designs, the plan for manufacturing and test results. In the manufacturing of the magnets, emphasis has been placed on uniformity of their performance and on quality. Results so far indicate that this emphasis has been very successful.

  13. The magnet system of the Relativistic Heavy Ion Collider (RHIC)

    SciTech Connect

    Greene, A.; Anerella, M.; Cozzolino, J.

    1996-07-01

    The Relativistic Heavy Ion Collider now under construction at Brookhaven National Laboratory (BNL) is a colliding ring accelerator to be completed in 1999. Through collisions of heavy ions it is hoped to observe the creation of matter at extremely high temperatures and densities, similar to what may have occurred in the original ``Big Bang``. The collider rings will consist of 1,740 superconducting magnet elements. Some of these elements are being manufactured by industrial partners (Northrop Grumman and Everson Electric). Others are being constructed or assembled at BNL. A description is given of the magnet designs, the plan for manufacturing and test results. In the manufacturing of the magnets, emphasis has been placed on uniformity of their performance and on quality. Results so far indicate that this emphasis has been very successful.

  14. Selected experimental results from heavy-ion collisions at LHC

    DOE PAGESBeta

    Singh, Ranbir; Kumar, Lokesh; Netrakanti, Pawan Kumar; Mohanty, Bedangadas

    2013-01-01

    We reviewmore » a subset of experimental results from the heavy-ion collisions at the Large Hadron Collider (LHC) facility at CERN. Excellent consistency is observed across all the experiments at the LHC (at center of mass energysNN=2.76 TeV) for the measurements such as charged particle multiplicity density, azimuthal anisotropy coefficients, and nuclear modification factor of charged hadrons. Comparison to similar measurements from the Relativistic Heavy Ion Collider (RHIC) at lower energy (sNN=200 GeV) suggests that the system formed at LHC has a higher energy density and larger system size and lives for a longer time. These measurements are compared to model calculations to obtain physical insights on the properties of matter created at the RHIC and LHC.« less

  15. UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS.

    SciTech Connect

    STEINBERG,P.A.FOR THE PHOBOS COLLABORATION

    2002-07-24

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at {radical}(s{sub NN}) = 19.6, 130 and 200 GeV. Two observations indicate universal behavior of charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and e{sup +}e{sup -} data. / in nuclear collisions at high energy scales with {radical}s in a similar way as N{sub ch} in e{sup +}e{sup -} collisions and has a very weak centrality dependence. These features may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  16. Hypertriton and light nuclei production at Lambda-production subthreshold energy in heavy-ion collisions

    SciTech Connect

    Zhang, S.; Zu, Z.; Chen, J.H., Ma, Y.G., Cai, X-Z, Ma, G.L., Zhong, C.

    2011-08-01

    High-energy heavy-ion collisions produce abundant hyperons and nucleons. A dynamical coalescence model coupled with the ART model is employed to study the production probabilities of light clusters, deuteron (d), triton (t), helion ({sup 3}He), and hypertriton ({sub {Lambda}}{sup 3}H) at subthreshold energy of Aproduction ({approx} 1 GeV per nucleon). We study the dependence on the reaction system size of the coalescence penalty factor per additional nucleon and entropy per nucleon. The Strangeness Population Factor (S{sub 3} = {sup 3}{sub {Lambda}}H/({sup 3}He x {Lambda}/p)) shows an extra suppression of hypertriton comparing to light clusters of the same mass number. This model predicts a hypertriton production cross-section of a few {mu}b in {sup 36}Ar+{sup 36}Ar, {sup 40}Ca+{sup 40}Ca and {sup 56}Ni+{sup 56}Ni in 1 A GeV reactions. The production rate is as high as a few hypertritons per million collisions, which shows that the fixed-target heavy-ion collisions at CSR (Lanzhou/China) at {Lambda} subthreshold energy are suitable for breaking new ground in hypernuclear physics.

  17. HEAVY ION COLLISIONS AND NEW FORMS OF MATTER

    SciTech Connect

    MCLERRAN,L.

    2007-07-02

    I discuss forms of high energy density matter in QCD. These include the Color Glass Condensate, the Glasma and the Quark Gluon Plasma. These all might be studied in ultra-relativistic heavy ion collisions, and the Color Glass Condensate might also be probed in electron-hadron collisions. I present the properties of such matter, and some aspects of what is known of their properties.

  18. Isotope analysis in central heavy ion collisions at intermediate energies

    NASA Astrophysics Data System (ADS)

    Geraci, E.; Abbondanno, U.; Bardelli, L.; Barlini, S.; Bini, M.; Bruno, M.; Cannata, F.; Casini, G.; Chiari, M.; D'Agostino, M.; de Sanctis, J.; Giussani, A.; Gramegna, F.; Kravchuk, V. L.; Lanchais, A. L.; Marini, P.; Moroni, A.; Nannini, A.; Olmi, A.; Ordine, A.; Pasquali, G.; Piantelli, S.; Poggi, G.; Vannini, G.; Nucl-Ex Collaboration

    2007-11-01

    Symmetry energy is a key quantity in the study of the equation of state of asymmetric nuclear matter. Heavy ion collisions at low and intermediate energies, performed at Laboratori Nazionali di Legnaro and Laboratori Nazionali del Sud, can be used to extract information on the symmetry energy coefficient Csym, which is currently poorly known but relevant both for astrophysics and for deeper knowledge of the structure of exotic nuclei.

  19. Calculations of heavy ion charge state distributions for nonequilibrium conditions

    NASA Technical Reports Server (NTRS)

    Luhn, A.; Hovestadt, D.

    1985-01-01

    Numerical calculations of the charge state distributions of test ions in a hot plasma under nonequilibrium conditions are presented. The mean ionic charges of heavy ions for finite residence times in an instantaneously heated plasma and for a non-Maxwellian electron distribution function are derived. The results are compared with measurements of the charge states of solar energetic particles, and it is found that neither of the two simple cases considered can explain the observations.

  20. Measurements of Thermal Photons in Heavy Ion Collisions with PHENIX

    SciTech Connect

    Dahms, T.; Awes, Terry C; Cianciolo, Vince; Efremenko, Yuri V; Enokizono, Akitomo; Hornback, Donald; Read Jr, Kenneth F; Silvermyr, David O; Sorensen, Soren P; Stankus, Paul W; Young, Glenn R; PHENIX, Collaboration

    2008-01-01

    Thermal photons are thought to be the ideal probe to measure the temperature of the quark-gluon plasma created in heavy ion collisions. PHENIX has measured direct photons with p{sub T} < 5 GeV/c via their internal conversions into e{sup +}e{sup -} pairs in Au+Au collisions at {radical}s{sub NN} = 200 GeV and has now provided a baseline measurement from p + p data.

  1. An integrated systems model for heavy ion drivers

    SciTech Connect

    Bangerter, R O; Faltens, A; Meier, W R

    1998-09-02

    A source-to-target computer model for an induction linac driver for heavy ion fusion has been developed and used to define a reference case driver that meets the requirements of one current target design. Key features of the model are discussed, and the design parameters of the reference case design are described. Examples of the systems analyses leading to the point design are given, and directions for future work are noted.

  2. Production of 14 MeV neutrons by heavy ions

    DOEpatents

    Brugger, Robert M.; Miller, Lowell G.; Young, Robert C.

    1977-01-01

    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.

  3. Six tesla analyzing magnet for heavy-ion beam transport

    SciTech Connect

    Smith, R.P.; Bollinger, L.; Erskine, J.; Genens, L.; Hoffman, J.

    1980-01-01

    A superconducting analyzer magnet for particle beam deflection has been designed and is being fabricated for use at the Argonne Tandem-Linac Accelerator System (ATLAS). This six tesla magnet will provide 45/sup 0/ of deflection for the heavy-ion beams from the ATLAS tandem electrostatic accelerator and together with its twin will replace the existing conventional 90/sup 0/ analyzer magnet which will become inadequate when ATLAS is completed.

  4. Is laser cooling for heavy-ion fusion feasible?

    NASA Astrophysics Data System (ADS)

    Ho, D. D.-M.; Brandon, S. T.

    2010-12-01

    Heavy-ion beams, each with current in the kiloampere range and particle energy in the giga-electronvolt range, must be focused onto a millimetre-size spot to provide the power required for ignition of high-gain targets for inertial confinement fusion. However, the focal spot size is always enlarged by chromatic aberration generated by the thermal spread of the beam ions in the direction of beam propagation. Enlarged focal spot degrades the target performance. For high-current beams, the conventional remedy for chromatic aberration using sextupole magnets has been shown to be ineffective. If novel correction schemes can be found, then the spot size can be reduced to below that previously believed possible. Smaller spots can mean lower energy targets so that the heavy-ion fusion (HIF) scenario can look more attractive. Success in laser cooling of ion beams in storage rings has inspired us to explore the feasibility of applying laser cooling for HIF, and the recirculator configuration proposed for HIF appears to be well suited for this purpose. However, using particle-in-cell simulations and theoretical arguments, we demonstrate in this paper that although laser cooling of heavy-ion beams is feasible in principle, the rapid velocity-space diffusion of ions in the bump-in-tail distribution, set up by the cooling lasers, limits the velocity-space compressibility of the thermal spread along the beam. Consequently, laser cooling is impractical for high-current, heavy-ion beams for the proposed recirculator configuration. Nevertheless, if the recirculator architecture or the target requirement can reduce the beam current, then the cooling scheme described here would be useful. This scheme may also be applicable to the RF linac and storage ring approach to HIF.

  5. Range and etching behaviour of swift heavy ions in polymers

    NASA Astrophysics Data System (ADS)

    Singh, Lakhwant; Singh, Mohan; Samra, Kawaljeet Singh; Singh, Ravinder

    Aliphatic (CR-39) and aromatic (Lexan polycarbonate) polymers have been irradiated with a variety of heavy ions such as 58Ni, 93Nb, 132Xe, 139La, 197Au, 208Pb, 209Bi, and 238U having energy ranges of 5.60-8.00 MeV/n in order to study the range and etching kinetics of heavy ion tracksE The ion fluence (range ˜104-105 ions/cm2) was kept low to avoid the overlapping of etched tracks. The measured values of maximum etched track length were corrected due to bulk etching and over etching to obtain the actual range. The experimental results of range profiles were compared with those obtained by the most used procedures employed in obtaining range and stopping power. The range values of present ions have been computed using the semiempirical codes (SRIM-98, SRIM-2003.26, and LISE++:0-[Hub90]) in order to check their accuracy. The merits and demerits of the adopted formulations have been highlighted in the present work. It is observed that the range of heavy ions is greater in aromatic polymers (Lexan polycarbonate) as compared to the aliphatic polymers (CR-39) irradiated with similar ions having same incident energies. The SRIM-98 and SRIM2003.26 codes don't show any significant trend in deviations, however, LISE++:0-[Hub90] code provides overall good agreement with the experimental values. The ratio of track etch rate (along projectile trajectory) to the bulk etch rate has also been studied as a function of energy loss of heavy ions in these polymers.

  6. Coherent rho(0) production in ultraperipheral heavy-ion collisions.

    PubMed

    Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Deng, W S; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Nystrand, J; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

    2002-12-30

    The STAR Collaboration reports the first observation of exclusive rho(0) photoproduction, AuAu-->AuAurho(0), and rho(0) production accompanied by mutual nuclear Coulomb excitation, AuAu-->Au*Au*rho(0), in ultraperipheral heavy-ion collisions. The rho(0) have low transverse momenta, consistent with coherent coupling to both nuclei. The cross sections at sqrt[s(NN)]=130 GeV agree with theoretical predictions treating rho(0) production and Coulomb excitation as independent processes. PMID:12513197

  7. Quantum Electrodynamics Effects in Heavy Ions and Atoms

    SciTech Connect

    Shabaev, V. M.; Andreev, O. V.; Bondarev, A. I.; Glazov, D. A.; Kozhedub, Y. S.; Maiorova, A. V.; Tupitsyn, I. I.; Plunien, G.; Volotka, A. V.

    2011-05-11

    Quantum electrodynamics theory of heavy ions and atoms is considered. The current status of calculations of the binding energies, the hyperfine splitting and g factor values in heavy few-electron ions is reviewed. The theoretical predictions are compared with available experimental data. A special attention is focused on tests of quantum electrodynamics in strong electromagnetic fields and on determination of the fundamental constants. Recent progress in calculations of the parity nonconservation effects with heavy atoms and ions is also reported.

  8. Aspects of heavy-ion collisions at the LHC

    SciTech Connect

    Wolschin, G.

    2014-01-14

    Three aspects of relativistic heavy-ion collisions are considered in this article: (1) Stopping and baryon transport in a QCD-based approach, (2) charged-hadron production in a nonequilibrium-statistical relativistic diffusion model (RDM), and (3) quarkonia suppression and in particular, Υ suppression in PbPb at the current LHC energy of √(s{sub NN}) = 2.76TeV.

  9. Dynamics of heavy ion beams during longitudinal compression

    SciTech Connect

    Ho, D.D.M.; Bangerter, R.O.; Lee, E.P.; Brandon, S.; Mark, J.W.K.

    1987-03-13

    Heavy ion beams with initially uniform line charge density can be compressed longitudinally by an order of magnitude in such a way that the compressed beam has uniform line charge density and velocity-tilt profiles. There are no envelope mismatch oscillations during compression. Although the transverse temperature varies along the beam and also varies with time, no substantial longitudinal and transverse emittance growth has been observed. Scaling laws for beam radius and transport system parameters are given.

  10. SIMULATION OF CHAMBER TRANSPORT FOR HEAVY-ION FUSION DRIVERS

    SciTech Connect

    Sharp, W M; Callahan, D A; Tabak, M; Yu, S S; Peterson, P F; Rose, D V; Welch, D R

    2004-05-20

    The heavy-ion fusion (HIF) community recently developed a power-plant design that meets the various requirements of accelerators, final focus, chamber transport, and targets. The point design is intended to minimize physics risk and is certainly not optimal for the cost of electricity. Recent chamber-transport simulations, however, indicate that changes in the beam ion species, the convergence angle, and the emittance might allow more-economical designs.

  11. LHC INTERACTION REGION CORRECTION IN HEAVY ION OPERATION

    SciTech Connect

    PTITSIN,V.; FISCHER,W.; WEI,J.

    1999-09-07

    In heavy ion operation the LHC interaction region at IP2 will have a low-{beta} optics for collisions. The dynamic aperture is therefore sensitive to magnetic field errors in the interaction region quadrupoles and dipoles. The authors investigate the effect of the magnetic field errors on the dynamic aperture and evaluate the effectiveness of local interaction region correctors. The dynamic aperture and the tune space are computed for different crossing angles.

  12. BRAHMS collaboration results for relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Arsene, I.

    2008-12-01

    In this work we review very briefly a few of the most important results obtained by the BRAHMS Collaboration on the properties of the collisions of heavy ions at relativistic energies. The discussion is general and aims to illustrate the most important achievements of our collaboration during the RHIC run period with short discussions and references to articles that treat the subjects in more detail.

  13. Mass spectra of heavy ions near comet Halley

    NASA Technical Reports Server (NTRS)

    Korth, A.; Richter, A. K.; Loidl, A.; Anderson, K. A.; Carlson, C. W.

    1986-01-01

    The heavy-ion analyzer, RPA2-PICCA, aboard the Giotto spacecraft, detected the first cometary ions at a distance of about 1.05 million km from the nucleus of comet Halley. In the inner coma the major ions identified are associated with the H2O, CO and CO2 groups. Ions of larger atomic mass unit are also present, corresponding possibly to various hydrocarbons, heavy metals of the iron-group or to sulphur compounds.

  14. Mini-proceedings of the workshop on heavy ion physics and instrumentation for a 15-Tm booster and storage ring

    SciTech Connect

    Not Available

    1986-11-01

    The goal of this workshop was to probe in depth a few of the areas of possible physics made possible by the availability of an intermediate energy heavy-ion physics facility. There was a special emphasis on physics that would be possible only with a storage/cooler ring. Topics discussed were nuclei far from stability, quantum electrodynamics, giant resonances and photonuclear reactions, and high energy gamma-ray production. Individual papers in this meeting were abstracted separately.

  15. Mutagenic effects of heavy ion radiation in plants

    NASA Technical Reports Server (NTRS)

    Mei, M.; Deng, H.; Lu, Y.; Zhuang, C.; Liu, Z.; Qiu, Q.; Qiu, Y.; Yang, T. C.

    1994-01-01

    Genetic and developmental effects of heavy ions in maize and rice were investigated. Heavy particles with various charges and energies were accelerated at the BEVALAC. The frequency of occurrence of white-yellow stripes on leaves of plants developed from irradiated maize seeds increased linearly with dose, and high Linear Energy Transfer (LET) heavy charged particles, e.g., neon, argon, and iron, were 2-12 times as effective as gamma rays in inducing this type of mutation. The effectiveness of high-LET heavy ion in (1) inhibiting rice seedling growth, (2) reducing plant fertility, (3) inducing chromosome aberration and micronuclei in root tip cells and pollen mother cells of the first generation plants developed from exposed seeds, and (4) inducing mutation in the second generation, were greater than that of low-LET gamma rays. All effects observed were dose-dependent; however, there appeared to be an optimal range of doses for inducing certain types of mutation, for example, for argon ions (400 MeV/u) at 90-100 Gy, several valuable mutant lines with favorable characters, such as semidwarf, early maturity and high yield ability, were obtained. Experimental results suggest that the potential application of heavy ions in crop improvement is promising. Restriction-fragment-length-polymorphism (RFLP) analysis of two semidwarf mutants induced by argon particles revealed that large DNA alterations might be involved in these mutants.

  16. Solar wind heavy ions from flare-heated coronal plasma

    NASA Technical Reports Server (NTRS)

    Bame, S. J.; Asbridge, J. R.; Feldman, W. C.; Fenimore, E. E.; Gosling, J. T.

    1979-01-01

    Information concerning the coronal expansion is carried by solar-wind heavy ions. Distinctly different energy-per-charge ion spectra are found in two classes of solar wind having the low kinetic temperatures necessary for E/q resolution of the ion species. Heavy-ion spectra which can be resolved are most frequently observed in the low-speed interstream (IS) plasma found between high speed streams; the streams are thought to originate from coronal holes. Although the sources of the IS plasma are uncertain, the heavy-ion spectra found there contain identifiable peaks of O, Si, and Fe ions. Such spectra indicate that the IS ionization state of O is established in coronal gas at a temperature of approximately 1.6 million K, while that of Fe is frozen in farther out at about 1.5 million K. On occasion anomalous spectra are found outside IS flows in solar wind with abnormally depressed local kinetic temperatures. The anomalous spectra contain Fe(16+) ions, not usually found in IS flows, and the derived coronal freezing-in temperatures are significantly higher. The coronal sources of some of these ionizationally hot flows are identified as solar flares.

  17. Preliminary results from the heavy ions in space experiment

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.; Beahm, Lorraine P.; Tylka, Allan J.

    1992-01-01

    The Heavy Ions In Space (HIIS) experiment has two primary objectives: (1) to measure the elemental composition of ultraheavy galactic cosmic rays, beginning in the tin-barium region of the periodic table; and (2) to study heavy ions which arrive at LDEF below the geomagnetic cutoff, either because they are not fully stripped of electrons or because their source is within the magnetosphere. Both of these objectives have practical as well as astrophysical consequences. In particular, the high atomic number of the ultraheavy galactic cosmic rays puts them among the most intensely ionizing particles in Nature. They are therefore capable of upsetting electronic components normally considered immune to such effects. The below cutoff heavy ions are intensely ionizing because of their low velocity. They can be a significant source of microelectronic anomalies in low inclination orbits, where Earth's magnetic field protects satellites from most particles from interplanetary space. The HIIS results will lead to significantly improved estimates of the intensely ionizing radiation environment.

  18. Uniformity of fuel target implosion in heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Kawata, S.; Noguchi, K.; Suzuki, T.; Karino, T.; Barada, D.; Ogoyski, A. I.; Ma, Y. Y.

    2015-12-01

    In inertial confinement fusion the target implosion non-uniformity is introduced by a driver beams' illumination non-uniformity, a fuel target alignment error in a fusion reactor, the target fabrication defect, et al. For a steady operation of a fusion power plant the target implosion should be robust against the implosion non-uniformities. In this paper the requirement for the implosion uniformity is first discussed. The implosion uniformity should be less than a few percent. A study on the fuel hotspot dynamics is also presented and shows that the stagnating plasma fluid provides a significant enhancement of vorticity at the final stage of the fuel stagnation. Then non-uniformity mitigation mechanisms of the heavy ion beam (HIB) illumination are also briefly discussed in heavy ion inertial fusion (HIF). A density valley appears in the energy absorber, and the large-scale density valley also works as a radiation energy confinement layer, which contributes to a radiation energy smoothing. In HIF a wobbling heavy ion beam illumination was also introduced to realize a uniform implosion. In the wobbling HIBs illumination, the illumination non-uniformity oscillates in time and space on a HIF target. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs' illumination non-uniformity by its smoothing effect on the HIB illumination non-uniformity and also by a growth mitigation effect on the Rayleigh-Taylor instability.

  19. L X-ray emission induced by heavy ions

    NASA Astrophysics Data System (ADS)

    Pajek, M.; Banaś, D.; Braziewicz, J.; Majewska, U.; Semaniak, J.; Fijał-Kirejczyk, I.; Jaskóła, M.; Czarnacki, W.; Korman, A.; Kretschmer, W.; Mukoyama, T.; Trautmann, D.

    2015-11-01

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster-Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L2-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  20. Heavy ion induced changes in small intestinal parameters

    NASA Astrophysics Data System (ADS)

    Carr, K. E.; McCullough, J. S.; Brennan, P.; Hayes, T. L.; Ainsworth, E. J.; Nelson, A. C.

    1994-10-01

    The effects on 17 different structural parameters of mouse small intestine three days after treatment with three types of heavy ion (neon, iron and niobium) are compared, the first two being of particular relevance to space flight. The data for niobium are given in full, showing that changes after niobium ion treatment are not standard and are concentrated in the epithelial compartment, with few of the parameters having a response which is dose dependent. When comparisons are made for the three types of heavy ion, the damage is greatest after neon ion irradiation, implying that the additional non-epithelial damage produced as LET rises from X rays through neutrons to neon ions is not necessarily maintained as LET continues to rise. Further understanding is therefore needed of the balance between changes affecting the vascular and absorptive components of the organ. Variation from group to group is also important, as is variation of strain or gastrointestinal status. All such factors are important in the understanding of changes in multicellular organs after exposure to heavy ion radiation.

  1. Heavy Ion Inertial Fusion Energy: Summaries of Program Elements

    SciTech Connect

    Friedman, A; Barnard, J J; Kaganovich, I; Seidl, P A; Briggs, R J; Faltens, A; Kwan, J W; Lee, E P; Logan, B G

    2011-02-28

    The goal of the Heavy Ion Fusion (HIF) Program is to apply high-current accelerator technology to IFE power production. Ion beams of mass {approx}100 amu and kinetic energy {>=} 1 GeV provide efficient energy coupling into matter, and HIF enjoys R&D-supported favorable attributes of: (1) the driver, projected to be robust and efficient; see 'Heavy Ion Accelerator Drivers.'; (2) the targets, which span a continuum from full direct to full indirect drive (and perhaps fast ignition), and have metal exteriors that enable injection at {approx}10 Hz; see 'IFE Target Designs'; (3) the near-classical ion energy deposition in the targets; see 'Beam-Plasma Interactions'; (4) the magnetic final lens, robust against damage; see 'Final Optics-Heavy Ion Beams'; and (5) the fusion chamber, which may use neutronically-thick liquids; see 'Liquid-Wall Chambers.' Most studies of HIF power plants have assumed indirect drive and thick liquid wall protection, but other options are possible.

  2. Effect of charge density in chain extension reactions involving complexes of 4, 4'-diaminodiphenylmethane and various alkali metal salts

    NASA Astrophysics Data System (ADS)

    Deshmukh, Subrajeet; Carrasquillo, Katherine; Tsai, Fang Chang; Wu, Lina; Hsu, Shaw Ling; University of Massachusetts Amherst Team

    Controlling the reaction of methylene diphenyl diisocyanate (MDI)-terminated polyester prepolymer and 4, 4'-diaminodiphenylmethane (MDA) is extremely important in many large scale applications. The ion-diamine complex has the advantage of blocking the instantaneous reaction between the diamine and isocyanate from taking place until it is released at elevated temperatures. We synthesized complexes of MDA with various alkali metal salts. These complexes create a barrier between the diamine and isocyanate thus preventing the premature reaction. We compared the complexes in terms of their dissociation and the subsequent curing with the prepolymer. Charge density had a tremendous effect. DSC showed that Na complexes dissociated at a lower temperature and needed less energy to dissociate than the Li complexes. The effect of change in cation on complex dissociation was more pronounced compared to the change in anion. Also, the ionic liquid introduced greatly altered the dissociation behavior. Temperature and time resolved IR spectroscopy was used to monitor the urea and NH band. By DSC and IR, we showed that NaCl complex is best suited for the curing of prepolymer with regards to curing temperature and energy.

  3. Experimental research of heavy ion and proton induced single event effects for a Bi-CMOS technology DC/DC converter

    NASA Astrophysics Data System (ADS)

    Anlin, He; Gang, Guo; Shuting, Shi; Dongjun, Shen; Jiancheng, Liu; Li, Cai; Hui, Fan

    2015-11-01

    This paper tested and analyzed heavy ion and proton induced single event effects (SEE) of a commercial DC/DC converter based on a 600 nm Bi-CMOS technology. Heavy ion induced single event transients (SET) testing has been carried out by using the Beijing HI-13 tandem accelerator at China Institute of Atomic Energy. Proton test has been carried out by using the Canadian TRIUMF proton accelerator. Both SET cross section versus linear energy transfer (LET) and proton energy has been measured. The main study conclusions are: (1) the DC/DC is both sensitive to heavy ion and proton radiations although at a pretty large feature size (600 nm), and threshold LET is about 0.06 MeV·mg/cm2 (2) heavy ion SET saturation cross section is about 5 magnitudes order larger than proton SET saturation cross section, which is consistent with the theory calculation result deduced by the RPP model and the proton nuclear reaction model; (3) on-orbit soft error rate (SER) prediction showed, on GEO orbit, proton induced SERs calculated by the heavy ion derived model are 4-5 times larger than those calculated by proton test data.

  4. The new Heavy-ion MCP-based Ancillary Detector DANTE for the CLARA-PRISMA Setup

    SciTech Connect

    Valiente-Dobon, J. J.; Gadea, A.; Corradi, L.; De Angelis, G.; Della Vedova, F.; Fioretto, E.; Marginean, N.; Napoli, D. R.; Orlandi, R.; Pokrovsky, I.; Sahin, E.; Stefanini, A. M.; Brambilla, S.; Kondratiev, N. A.; Kozulin, E. M.; Beghini, S.; Farnea, E.; Lunardi, S.; Montagnoli, G.; Ur, C. A.

    2006-08-14

    The CLARA-PRISMA setup is a powerful tool for spectroscopic studies of neutron-rich nuclei produced in multi-nucleon transfer and deep-inelastic reactions. It combines the large acceptance spectrometer PRISMA with the {gamma}-ray array CLARA. At present, the ancillary heavy-ion detector DANTE, based on Micro-Channel Plates to be installed at the CLARA-PRISMA setup, is being constructed at LNL. DANTE will open the possibility of measuring {gamma}-{gamma} Doppler-corrected coincidences for the events outside the acceptance of PRISMA. In this presentation, it is described the heavy-ion detector DANTE, as well as the performances of the first prototype.

  5. Nuclear quantum many-body dynamics. From collective vibrations to heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Simenel, Cédric

    2012-11-01

    A summary of recent researches on nuclear dynamics with realistic microscopic quantum approaches is presented. The Balian-Vénéroni variational principle is used to derive the time-dependent Hartree-Fock (TDHF) equation describing the dynamics at the mean-field level, as well as an extension including small-amplitude quantum fluctuations which is equivalent to the time-dependent random-phase approximation (TDRPA). Such formalisms as well as their practical implementation in the nuclear physics framework with modern three-dimensional codes are discussed. Recent applications to nuclear dynamics, from collective vibrations to heavy-ion collisions are presented. Particular attention is devoted to the interplay between collective motions and internal degrees of freedom. For instance, the harmonic nature of collective vibrations is questioned. Nuclei are also known to exhibit superfluidity due to pairing residual interaction. Extensions of the theoretical approach to study such pairing vibrations are now available. Large amplitude collective motions are investigated in the framework of heavy-ion collisions leading, for instance, to the formation of a compound system. How fusion is affected by the internal structure of the collision partners, such as their deformation, is discussed. Other mechanisms in competition with fusion, and responsible for the formation of fragments which differ from the entrance channel (transfer reactions, deep-inelastic collisions, and quasi-fission) are investigated. Finally, studies of actinide collisions forming, during very short times of few zeptoseconds, the heaviest nuclear systems available on Earth, are presented.

  6. Heavy-ion physics with the ALICE experiment at the CERN Large Hadron Collider.

    PubMed

    Schukraft, J

    2012-02-28

    After close to 20 years of preparation, the dedicated heavy-ion experiment A Large Ion Collider Experiment (ALICE) took first data at the CERN Large Hadron Collider (LHC) accelerator with proton collisions at the end of 2009 and with lead nuclei at the end of 2010. After a short introduction into the physics of ultra-relativistic heavy-ion collisions, this article recalls the main design choices made for the detector and summarizes the initial operation and performance of ALICE. Physics results from this first year of operation concentrate on characterizing the global properties of typical, average collisions, both in proton-proton (pp) and nucleus-nucleus reactions, in the new energy regime of the LHC. The pp results differ, to a varying degree, from most quantum chromodynamics-inspired phenomenological models and provide the input needed to fine tune their parameters. First results from Pb-Pb are broadly consistent with expectations based on lower energy data, indicating that high-density matter created at the LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect liquid.

  7. Investigation of the heavy-ion mode in the FAIR High Energy Storage Ring

    NASA Astrophysics Data System (ADS)

    Kovalenko, O.; Dolinskii, O.; Litvinov, Yu A.; Maier, R.; Prasuhn, D.; Stöhlker, T.

    2015-11-01

    High energy storage ring (HESR) as a part of the future accelerator facility FAIR (Facility for Antiproton and Ion Research) will serve for a variety of internal target experiments with high-energy stored heavy ions (SPARC collaboration). Bare uranium is planned to be used as a primary beam. Since a storage time in some cases may be significant—up to half an hour—it is important to examine the high-order effects in the long-term beam dynamics. A new ion optics specifically for the heavy ion mode of the HESR is developed and is discussed in this paper. The subjects of an optics design, tune working point and a dynamic aperture are addressed. For that purpose nonlinear beam dynamics simulations are carried out. Also a flexibility of the HESR ion optical lattice is verified with regard to various experimental setups. Specifically, due to charge exchange reactions in the internal target, secondary beams, such as hydrogen-like and helium-like uranium ions, will be produced. Thus the possibility of separation of these secondary ions and the primary {{{U}}}92+ beam is presented with different internal target locations.

  8. Effects of heavy ions on visual function and electrophysiology of rodents: the ALTEA-MICE project

    NASA Astrophysics Data System (ADS)

    Sannita, W. G.; Acquaviva, M.; Ball, S. L.; Belli, F.; Bisti, S.; Bidoli, V.; Carozzo, S.; Casolino, M.; Cucinotta, F.; De Pascale, M. P.; Di Fino, L.; Di Marco, S.; Maccarone, R.; Martello, C.; Miller, J.; Narici, L.; Peachey, N. S.; Picozza, P.; Rinaldi, A.; Ruggieri, D.; Saturno, M.; Schardt, D.; Vazquez, M.

    2004-01-01

    ALTEA-MICE will supplement the ALTEA project on astronauts and provide information on the functional visual impairment possibly induced by heavy ions during prolonged operations in microgravity. Goals of ALTEA-MICE are: (1) to investigate the effects of heavy ions on the visual system of normal and mutant mice with retinal defects; (2) to define reliable experimental conditions for space research; and (3) to develop animal models to study the physiological consequences of space travels on humans. Remotely controlled mouse setup, applied electrophysiological recording methods, remote particle monitoring, and experimental procedures were developed and tested. The project has proved feasible under laboratory-controlled conditions comparable in important aspects to those of astronauts' exposure to particle in space. Experiments are performed at the Brookhaven National Laboratories [BNL] (Upton, NY, USA) and the Gesellschaft für Schwerionenforschung mbH [GSI]/Biophysik (Darmstadt, FRG) to identify possible electrophysiological changes and/or activation of protective mechanisms in response to pulsed radiation. Offline data analyses are in progress and observations are still anecdotal. Electrophysiological changes after pulsed radiation are within the limits of spontaneous variability under anesthesia, with only indirect evidence of possible retinal/cortical responses. Immunostaining showed changes (e.g increased expression of FGF2 protein in the outer nuclear layer) suggesting a retinal stress reaction to high-energy particles of potential relevance in space.

  9. Effects of heavy ions on visual function and electrophysiology of rodents: the ALTEA-MICE project

    NASA Technical Reports Server (NTRS)

    Sannita, W. G.; Acquaviva, M.; Ball, S. L.; Belli, F.; Bisti, S.; Bidoli, V.; Carozzo, S.; Casolino, M.; Cucinotta, F.; De Pascale, M. P.; Di Fino, L.; Di Marco, S.; Maccarone, R.; Martello, C.; Miller, J.; Narici, L.; Peachey, N. S.; Picozza, P.; Rinaldi, A.; Ruggieri, D.; Saturno, M.; Schardt, D.; Vazquez, M.; Lowenstein, D. (Principal Investigator)

    2004-01-01

    ALTEA-MICE will supplement the ALTEA project on astronauts and provide information on the functional visual impairment possibly induced by heavy ions during prolonged operations in microgravity. Goals of ALTEA-MICE are: (1) to investigate the effects of heavy ions on the visual system of normal and mutant mice with retinal defects; (2) to define reliable experimental conditions for space research; and (3) to develop animal models to study the physiological consequences of space travels on humans. Remotely controlled mouse setup, applied electrophysiological recording methods, remote particle monitoring, and experimental procedures were developed and tested. The project has proved feasible under laboratory-controlled conditions comparable in important aspects to those of astronauts' exposure to particle in space. Experiments are performed at the Brookhaven National Laboratories [BNL] (Upton, NY, USA) and the Gesellschaft fur Schwerionenforschung mbH [GSI]/Biophysik (Darmstadt, FRG) to identify possible electrophysiological changes and/or activation of protective mechanisms in response to pulsed radiation. Offline data analyses are in progress and observations are still anecdotal. Electrophysiological changes after pulsed radiation are within the limits of spontaneous variability under anesthesia, with only indirect evidence of possible retinal/cortical responses. Immunostaining showed changes (e.g. increased expression of FGF2 protein in the outer nuclear layer) suggesting a retinal stress reaction to high-energy particles of potential relevance in space. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  10. Hadron production in relativistic heavy ion interactions and the search for the quark-gluon plasma

    SciTech Connect

    Tannenbaum, M.J.

    1989-12-01

    The course starts with an introduction, from the experimentalist's point of view, of the challenge of measuring Relativistic Heavy Ion interactions. A review of some theoretical predictions for the expected signatures of the quark gluon plasma will be made, with a purpose to understand how they relate to quantities which may be experimentally measured. A short exposition of experimental techniques and details is given including charged particles in matter, momentum resolution, kinematics and Lorentz Transformations, calorimetry. Principles of particle identification including magnetic spectrometers, time of flight measurement. Illustrations using the E802 spectrometer and other measured results. Resolution smearing of spectra, and binning effects. Parent to daughter effects in decay, with {pi}{sup 0} {yields} {gamma} {gamma} as an example. The experimental situation from the known data in p -- p collisions and proton-nucleus reactions is reviewed and used as a basis for further discussions. The Cronin Effect'' and the Seagull Effect'' being two arcana worth noting. Then, selected experiments from the BNL and CERN heavy ion programs are discussed in detail. 118 refs., 45 figs.

  11. How much do heavy quarks thermalize in a heavy ion collision?

    SciTech Connect

    Moore, Guy D.; Teaney, Derek

    2005-06-01

    We investigate the thermalization of charm quarks in high-energy heavy-ion collisions. To this end, we calculate the diffusion coefficient in the perturbative quark gluon plasma and relate it to collisional energy loss and momentum broadening. We then use these transport properties to formulate a Langevin model for the evolution of the heavy quark spectrum in the hot medium. The model is strictly valid in the nonrelativistic limit and for all velocities {gamma}v<{alpha}s{sup -1/2} to leading logarithm in T/m{sub D}. The corresponding Fokker-Planck equation can be solved analytically for a Bjorken expansion and the solution gives a simple estimate for the medium modifications of the heavy quark spectrum as a function of the diffusion coefficient. Finally we solve the Langevin equations numerically in a hydrodynamic simulation of the heavy-ion reaction. The results of this simulation are the medium modifications of the charm spectrum R{sub AA} and the expected elliptic flow v{sub 2}(p{sub T}) as a function of the diffusion coefficient.

  12. Studying the interplay of strong and electromagnetic forces in heavy-ion collisions with NICA

    NASA Astrophysics Data System (ADS)

    Rybicki, A.; Szczurek, A.; Kłusek-Gawenda, M.; Sputowska, I.

    2016-08-01

    In the following we stress the advantages of the NICA research programme in the context of studying the spectator-induced electromagnetic phenomena present in heavy-ion collisions. We point at the specific interest of using these phenomena as a new, independent source of information on the space-time evolution of the reaction and of the non-perturbative process of particle production. We propose an extended series of measurements of well-defined observables to be performed in different types of nuclear reactions and in the whole range of collision energies available to NICA. We expect these measurements to bring very valuable new insight into the mechanism of non-perturbative strong interactions, complementary to the studies made at the SPS at CERN, RHIC at BNL, and the LHC.

  13. The Mesozoic Era of relativistic heavy ion physics and beyond

    SciTech Connect

    Harris, J.W.

    1994-03-01

    In order to understand how matter 15 billion years ago in the form of quarks, gluons and leptons at a temperature of 2 {times} 10{sup 12} {degrees}K evolved to become today`s Universe, the goal of relativistic and ultra-relativistic heavy ion physics is to understand the equation of state of nuclear, hadronic and partonic matter. This quest is of cross-disciplinary interest. The phase transition from partonic matter to hadronic matter tens of micro-seconds after the beginning of the universe is of interest to cosmology. Fluctuations during this phase transition would influence nucleosynthesis and the understanding of baryonic inhomogeneities in the universe. The nuclear matter equation of state, which describes the incompressibility of nuclear matter, governs neutron star stability. It determines the possible existence of strange quark matter stars and the dynamics of supernova expansion in astrophysics. The existence of collective nuclear phenomena in nuclear physics is also determined by the nuclear equation of state. In relativistic heavy ion collisions collective nuclear flow has been observed and is being studied extensively to obtain a better understanding of the incompressibility of nuclear matter. In high energy nuclear and particle physics, production and excitations of hadronic final states have been studied in detail and are important to an overall understanding of the equation of state of nuclear matter at finite temperature. The possibility in ultra-relativistic heavy ion collisions to create and study highly excited hadronic and partonic degrees of freedom provides a unique opportunity for understanding the behavior of nuclear, hadronic and partonic matter. Study of the QCD vacuum, of particular interest in particle physics, would provide a better understanding of symmetry-breaking mechanisms and the origins of the masses of the various quarks and particles.

  14. Calorimetric low temperature detectors for mass identification of heavy ions

    NASA Astrophysics Data System (ADS)

    Kraft, S.; Bleile, A.; Egelhof, P.; Golser, R.; Kisselev, O.; Kutschera, W.; Liechtenstein, V.; Meier, H. J.; Priller, A.; Shrivastava, A.; Steier, P.; Vockenhuber, C.; Weber, M.

    2002-02-01

    The energy sensitive detection of heavy ions with calorimetric low temperature detectors (CLTDs) is investigated for the energy range E=0.1-1 MeV/u, commonly used for accelerator mass spectrometry (AMS). Such measurements complement earlier investigations [1, 2] at higher energies (E=5-300 MeV/u) where an energy resolution of ΔE/E=1-2×10-3 was obtained for various ion species. The detectors used consist of sapphire absorbers and superconducting transition edge thermometers operated at T~1.5 K. They were irradiated with various heavy ion beams (13C, 197Au, 238U) provided by the VERA tandem accelerator in Vienna, Austria. An energy resolution of ΔE/E=5-6×10-3 has been obtained even for heaviest ions like 197Au and 238U at E=0.1-0.3 MeV/u, thereby exceeding the resolution of conventional semiconductor detectors in this energy range by at least one order of magnitude. In addition, no evidence for pulse height defects has been observed. With the achieved performance, the present CLTDs bear a large potential for applications in various fields of heavy ion research. Of special interest is isotope mass identification via combined energy and time-of-flight (TOF) measurement. In present test measurements, including a standard TOF spectrometer, a clear separation of the isotopes 206Pb and 208Pb at E~0.1 MeV/u has been obtained. Such a detection scheme may in future provide substantial background suppression for AMS measurements. .

  15. Heating of heavy ions on auroral field lines

    SciTech Connect

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

    1983-01-01

    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.

  16. Calculation of relativistic effects in sub Coulomb heavy ion scattering

    NASA Astrophysics Data System (ADS)

    Hencken, Kai; Trautmann, Dirk

    1991-06-01

    Relativistic corrections for the elastic scattering of heavy ions in the sub Coulomb regime are given. The case of two identical particles is treated especially. The deviation from the Rutherford (Mott) cross section is calculated by using the Todorov equation and the Darwin Hamiltonian, resp. It is shown, that both approches lead to the same results for small kinetic energies. Furthermore we discuss the applicability of the WKB method for calculating the phase shifts and the possibility of using a classical perturbative approach in the case of nonidentical particles.

  17. Chamber transport of ''foot'' pulses for heavy-ion fusion

    SciTech Connect

    Sharp, W.M.; Callahan-Miller, D.A.; Tabak, M.; Yu, S.S.; Peterson, P.F.

    2002-02-20

    Indirect-drive targets for heavy-ion fusion must initially be heated by ''foot'' pulses that precede the main heating pulses by tens of nanoseconds. These pulses typically have a lower energy and perveance than the main pulses, and the fusion-chamber environment is different from that seen by later pulses. The preliminary particle-in-cell simulations of foot pulses here examine the sensitivity of the beam focusing to ion-beam perveance, background-gas density, and pre-neutralization by a plasma near the chamber entry port.

  18. Deciphering azimuthal correlations in relativistic heavy-ion collisions

    SciTech Connect

    Cetner, Tomasz; Grebieszkow, Katarzyna; Mrowczynski, Stanislaw

    2011-02-15

    We discuss various sources of azimuthal correlations in relativistic heavy-ion collisions. The integral measure {Phi} is applied to quantify the correlations. We first consider separately the correlations caused by the elliptic flow, resonance decays, jets, and transverse momentum conservation. An effect of randomly lost particles is also discussed. Using the PYTHIA and HIJING event generators we produce a sample of events that mimic experimental data. By means of kinematic cuts and particle selection criteria, the data are analyzed to identify a dominant source of correlations.

  19. Theory of nuclear excitation by electron capture for heavy ions

    SciTech Connect

    Palffy, Adriana; Scheid, Werner; Harman, Zoltan

    2006-01-15

    We investigate the resonant process of nuclear excitation by electron capture (NEEC), in which a continuum electron is captured into a bound state of an ion with the simultaneous excitation of the nucleus. In order to derive the cross section a Feshbach projection operator formalism is introduced. Nuclear states and transitions are described by a nuclear collective model and making use of experimental data. Transition rates and total cross sections for NEEC followed by the radiative decay of the excited nucleus are calculated for various heavy-ion collision systems.

  20. Nuclear multifragmentation: Antiprotons versus photons and heavy ions

    SciTech Connect

    Cugnon, J.

    1994-09-01

    Nuclear multifragmentation is the phenomenon by which a nucleus breaks into many pieces of intermediate size. It occurs in the excitation-energy regime, between the spallation + evaporation regime and the explosive fragmentation regime. The various models of multifragmentation are briefly reviewed and the possibility of critical behavior in the multifragmentation process is underlined. Unanswered problems are stated. It is shown, by model calculations, that antiproton annihilation is, in many respects, better suited than proton-nucleus and heavy-ion collisions for studying multifragmentation and, in other respects, complementary to these other tools. 36 refs., 17 figs., 1 tab.

  1. Disappearance of flow in heavy-ion collisions

    SciTech Connect

    Krofcheck, D.; Bauer, W.; Crawley, G.M.; Djalali, C.; Howden, S.; Ogilvie, C.A.; Vander Molen, A.; Westfall, G.D.; Wilson, W.K. ); Tickle, R.S. ); Gale, C. )

    1989-11-06

    We report the first observation of the disappearance of flow in heavy-ion collisions. This is accomplished by measuring the excitation function of the average in-plane transverse momentum for the symmetric system {sup 139}La+{sup 139}La, using beam energies of 130, 70, and 50 MeV/nucleon. The observation is indicative of a change from dominantly repulsive to attractive scattering. We also present the results of calculations performed with the Boltzmann-Uehling-Uhlenbeck equation which support the concept of vanishing flow for this system in the energy region between 30 and 50 MeV/nucleon.

  2. Superconducting focusing quadrupoles for heavy ion fusion experiments

    SciTech Connect

    Sabbi, G.L.; Faltens, A.; Leitner, M.; Lietzke, A.; Seidl, P.; Barnard, J.; Lund, S.; Martovetsky, N.; Gung, C.; Minervini, J.; Radovinsky, A.; Schultz, J.; Meinke, R.

    2003-05-01

    The Heavy Ion Fusion (HIF) Program is developing superconducting focusing magnets for both near-term experiments and future driver accelerators. In particular, single bore quadrupoles have been fabricated and tested for use in the High Current Experiment (HCX) at Lawrence Berkeley National Laboratory (LBNL). The next steps involve the development of magnets for the planned Integrated Beam Experiment (IBX) and the fabrication of the first prototype multi-beam focusing arrays for fusion driver accelerators. The status of the magnet R&D program is reported, including experimental requirements, design issues and test results.

  3. Simulation of Drift-Compression for Heavy-Ion-Fusion

    SciTech Connect

    Sharp, W M; Barnard, J J; Grote, D P; Celata, C M; Yu, S S

    2005-03-16

    Lengthwise compression of space-charge-dominated beams is needed to obtain the high input power required for heavy-ion fusion. The ''drift-compression'' scenario studied here first applies a head-to-tail velocity variation with the beam tail moving faster than the head. As the beam drifts, the longitudinal space-charge field slows compression, leaving the beam nearly monoenergetic as it enters the final-focus magnets. This paper presents initial work to model this compression scenario. Fluid and particle simulations are compared, and several strategies for setting up the compression schedule are discussed.

  4. Inclusive inelastic scattering of heavy ions and nuclear correlations

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.; Khandelwal, Govind S.

    1990-01-01

    Calculations of inclusive inelastic scattering distributions for heavy ion collisions are considered within the high energy optical model. Using ground state sum rules, the inclusive projectile and complete projectile-target inelastic angular distributions are treated in both independent particle and correlated nuclear models. Comparisons between the models introduced are made for alpha particles colliding with He-4, C-12, and O-16 targets and protons colliding with O-16. Results indicate that correlations contribute significantly, at small momentum transfers, to the inelastic sum. Correlation effects are hidden, however, when total scattering distributions are considered because of the dominance of elastic scattering at small momentum transfers.

  5. Optical model analyses of heavy ion fragmentation in hydrogen targets

    NASA Technical Reports Server (NTRS)

    Townsend, Lawrence W.

    1994-01-01

    Quantum-mechanical optical-model methods for calculating cross sections for the fragmentation of high-energy heavy ions by hydrogen targets are presented. The cross sections are calculated with a knockout-ablation collision formalism which has no arbitrary fitting parameters. Predictions of elemental production cross sections from the fragmentation of 1.2A Ge(V(La-139) nuclei and of isotope production cross sections from the fragmentation of 400A MeV(S-32) nuclei are in good agreement with recently reported experimental measurements.

  6. Jets and Vector Bosons in Heavy Ion Collisions

    NASA Astrophysics Data System (ADS)

    de la Cruz, Begoña

    2013-11-01

    This paper reviews experimental results on jets and electroweak boson (photon,Wand Z) production in heavy-ion collisions, from the CMS and ATLAS detectors, using data collected during 2011 PbPb run and pp data collected at an equivalent energy. By comparing the two collision systems, the energy loss of the partons propagating through the medium produced in PbPb collisions can be studied. Its characterization is done using dijet events and isolated photon-jet pairs. Since the electroweak gauge bosons do not participate in the strong interaction, and are thus unmodified by the nuclear medium, they serve as clean probes of the initial state in the collision.

  7. High Current Ion Sources and Injectors for Heavy Ion Fusion

    SciTech Connect

    Kwan, Joe W.

    2005-02-15

    Heavy ion beam driven inertial fusion requires short ion beam pulses with high current and high brightness. Depending on the beam current and the number of beams in the driver system, the injector can use a large diameter surface ionization source or merge an array of small beamlets from a plasma source. In this paper, we review the scaling laws that govern the injector design and the various ion source options including the contact ionizer, the aluminosilicate source, the multicusp plasma source, and the MEVVA source.

  8. Medical applications of nuclear physics and heavy-ion beams

    SciTech Connect

    Alonso, Jose R.

    2000-08-01

    Isotopes and accelerators, hallmarks of nuclear physics, are finding increasingly sophisticated and effective applications in the medical field. Diagnostic and therapeutic uses of radioisotopes are now a $10B/yr business worldwide, with over 10 million procedures and patient studies performed every year. This paper will discuss the use of isotopes for these applications. In addition, beams of protons and heavy ions are being more and more widely used clinically for treatment of malignancies. To be discussed here as well will be the rationale and techniques associated with charged-particle therapy, and the progress in implementation and optimization of these technologies for clinical use.

  9. Modeling heavy ion ionization loss in the MARS15 code

    SciTech Connect

    Rakhno, I.L.; Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2005-05-01

    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 ultrarelativistic 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.

  10. Heavy ion beam interaction with a direct-driven pellet

    NASA Astrophysics Data System (ADS)

    Someya, T.; Kikuchi, T.; Miyazawa, K.; Kawata, S.; Ogoyski, A. I.

    2006-06-01

    In heavy ion beam (HIB) inertial confinement fusion (ICF), key issues include beam illumination non-uniformity. In this study we simulate the HIB interaction with a direct-driven target. The main purposes of this study are to clarify the multi-HIB energy deposition non-uniformity onto a direct-driven target and to calculate the target hydrodynamics in HIF. The calculation results demonstrate that we can realize a rather low non-uniform energy deposition, for example, less than 2.0% even for a 32-HIBs irradiation system.

  11. Galactic heavy-ion shielding using electrostatic fields

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.

    1984-01-01

    The shielding of spacecraft against galactic heavy ions, particularly high-energy Fe(56) nuclei, by electrostatic fields is analyzed for an arrangement of spherical concentric shells. Vacuum breakdown considerations are found to limit the minimum radii of the spheres to over 100 m. This limitation makes it impractical to use the fields for shielding small spacecraft. The voltages necessary to repel these Fe(56) nuclei exceed present electrostatic generating capabilities by over 2 orders of magnitude and render the concept useless as an alternative to traditional bulk-material shielding methods.

  12. Gluon multiplication in high energy heavy ion collisions

    SciTech Connect

    Xiong, L.; Shuryak, E.V. )

    1994-04-01

    Hot gluons are the dominant components of the QCD plasma to be formed in future high energy heavy ion experiments. In this paper we study the elementary processes in the plasma medium for gluon multiplication based on all orders of the tree diagrams in perturbative QCD. When applying to the chemical equilibration in the expanding system, we found that the gluon reaches chemical equilibrium well within its plasma phase. The inclusion of all the next-to-leading-order processes makes the equilibration considerably faster than the simple [ital gg][leftrightarrow][ital ggg] one considered previously.

  13. Effect of heavy ion irradiation on C 60

    NASA Astrophysics Data System (ADS)

    Lotha, S.; Ingale, A.; Avasthi, D. K.; Mittal, V. K.; Mishra, S.; Rustagi, K. C.; Gupta, A.; Kulkarni, V. N.; Khathing, D. T.

    1999-06-01

    Thin films of C 60 were subjected to swift heavy ion irradiation spanning the region from 2 to 11 keV/nm of electronic excitation. Studies of the irradiated films by Raman spectroscopy indicated polymerization and damage of the film with an ion fluence. The ion track radii are estimated for various ions using the Raman data. Photoluminescence spectroscopy of the irradiated film indicated a decrease in the C 60 phase with a dose, and an increase in the intensity at the 590 nm wavelength, which is attributed to an increase in the oxygen content.

  14. From Stopping to Viscosity in Heavy Ion Collisions

    SciTech Connect

    Barker, Brent W.; Danielewicz, Pawel

    2010-04-26

    Stopping in heavy ion collisions is investigated with the aim of learning about the shear viscosity of nuclear matter. Boltzmann equation simulations are compared to available data on stopping in the energy range of 20-117 MeV/nucleon. Stopping observables used include momentum anisotropy and linear momentum transfer. The data show that modeling the transport with free nucleon-nucleon cross-sections is inaccurate and reduced cross-sections are required. Reduction of the cross-sections produces an increase in the shear viscosity of nuclear matter, compared to calculations based on free cross-sections.

  15. Beyond the thermal model in relativistic heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Wolschin, Georg

    2016-08-01

    Deviations from thermal distribution functions of produced particles in relativistic heavy-ion collisions are discussed as indicators for nonequilibrium processes. The focus is on rapidity distributions of produced charged hadrons as functions of collision energy and centrality, which are used to infer the fraction of particles produced from a central fireball as compared with that from the fragmentation sources that are out of equilibrium with the rest of the system. Overall thermal equilibrium would only be reached for large times t →∞ .

  16. Coupled alkali feldspar dissolution and secondary mineral precipitation in batch systems: 4. Numerical modeling of kinetic reaction paths

    NASA Astrophysics Data System (ADS)

    Zhu, Chen; Lu, Peng; Zheng, Zuoping; Ganor, Jiwchar

    2010-07-01

    This paper explores how dissolution and precipitation reactions are coupled in batch reactor experimental systems at elevated temperatures. This is the fourth paper in our series of "Coupled Alkali Feldspar Dissolution and Secondary Mineral Precipitation in Batch Systems". In our third paper, we demonstrated via speciation-solubility modeling that partial equilibrium between secondary minerals and aqueous solutions was not attained in feldspar hydrolysis batch reactors at 90-300 °C and that a strong coupling between dissolution and precipitation reactions follows as a consequence of the slower precipitation of secondary minerals ( Zhu and Lu, 2009). Here, we develop this concept further by using numerical reaction path models to elucidate how the dissolution and precipitation reactions are coupled. Modeling results show that a quasi-steady state was reached. At the quasi-steady state, dissolution reactions proceeded at rates that are orders of magnitude slower than the rates measured at far from equilibrium. The quasi-steady state is determined by the relative rate constants, and strongly influenced by the function of Gibbs free energy of reaction ( ΔG) in the rate laws. To explore the potential effects of fluid flow rates on the coupling of reactions, we extrapolate a batch system ( Ganor et al., 2007) to open systems and simulated one-dimensional reactive mass transport for oligoclase dissolution and kaolinite precipitation in homogeneous porous media. Different steady states were achieved at different locations along the one-dimensional domain. The time-space distribution and saturation indices (SI) at the steady states were a function of flow rates for a given kinetic model. Regardless of the differences in SI, the ratio between oligoclase dissolution rates and kaolinite precipitation rates remained 1.626, as in the batch system case ( Ganor et al., 2007). Therefore, our simulation results demonstrated coupling among dissolution, precipitation, and flow rates

  17. PREFACE: Heavy-Ion Spectroscopy and QED Effects in Atomic Systems

    NASA Astrophysics Data System (ADS)

    Lindgren, Ingvar; Martinson, Indrek; Schuch, Reinhold

    1993-01-01

    now essentially solved. The experimental accuracy is already so high that also higher-order QED effects become observable, and several groups are now active in trying to evaluate such effects from first principles. Another related field where substantial progress has recently been made involves precision measurements of X-ray transitions. This has created an interest in the study of deep inner holes in heavy atoms, where large relativistic and QED effects appear. These effects are as large as in corresponding highly charged ions, but the interpretation requires that the many-body effects from the surrounding electrons are accurately extracted. This is a big challenge at present. Atomic collision physics with highly charged ions has been dominated in recent years by the search for a possibility to describe electron-electron interaction within the dynamics of collisions. The experiments on multielectron transfer reactions with highly charged ions posed in this respect quite a challenge to the theory. The models developed to meet this were often based on methods and terminologies developed for describing the inter-electronic interactions in atomic structure. This caused many controversial discussions, also during this symposium. A new and fast rising field is the interaction of highly charged ions with solid surfaces. This may become an important link between atomic physics and condensed-matter physics, stimulated by the opportunity to study effects in coupled many-body systems present in the case when a large amount of electrons is transferred from the solid to each single ion. Furtheron, collision experiments with cooled ion beams in ion storage rings open new dimensions also for atomic spectroscopy. It appears possible that transition and binding energies can be measured in recombination of very heavy ions with a better quality than by conventional Auger electron or X-ray spectroscopy. Obviously, it is not possible to cover all the fields mentioned here in a single

  18. IR and XRD Study of the Tribochemical Reactions of Copper Sulfate with Alkali Halides

    NASA Astrophysics Data System (ADS)

    Fernández, J.; González, E.; de Oñate, J.; López, R.; Navarro, E.

    1993-12-01

    Tribochemical reactions of CuSO 4 · 5H 2O and CuSO 4 during milling with KCl, KBr, and KI have been studied by IR and XRD techniques. The reactions are rather similar for the hydrated and anhydrous salts, but proceed faster with the former. With KCl, the reaction leads directly to CuK 2SO 4Cl 2 also known as the mineral chlorothionite. With KBr, the mixed salts CuK 2(SO 4) 2 · 2H 2O and CuK 2 (SO 4) 2 · 6H 2O are first obtained which transform to a new compound upon further milling, that we postulate as CuK 2SO 4Br 2. With KI, there is a fast reaction to a mixture of CuK 2(SO 4) 2 · 6H 2O, γ-CuI, and I 2, later proceeding to K 2SO 4, γ-CuI, and I 2.

  19. Chemistry of alkali halide and ice surfaces: Characterization of reactions relevant to atmospheric chemistry

    NASA Astrophysics Data System (ADS)

    Zangmeister, Christopher Douglas

    Atmospherically-relevant surface reactions were studied. These reactions were investigated to provide insight into the products formed on sea salt atmospheric particle surfaces, the quantitative distribution of species on the surface of model sea salt particles, and the molecular environment of the interfacial region of HNO3/H2O ices. The reactions of model sea salt particles (NaCl) exposed to mineral acids (HNO3 and H2SO4) were studied using Raman spectroscopy and atomic force microscopy (AFM). The reaction of powdered NaCl with HNO3 was studied using Raman spectroscopy. NANO3 growth was monitored as a function of HNO3 exposure in a flow cell. Mode-specific changes in the NO3- vibrational mode intensities with HNO3 exposure suggest a rearrangement of the NaNO3 film with coverage. In the absence of H 2O, intensities of NaNO3 bands increase with HNO3 exposure until a capping layer of NaNO3 forms. The capping layer prevents subsequent HNO3 from reacting with the underlying. The reaction of NaCl with H2SO4 is investigated using Raman spectroscopy and atomic force microscopy (AFM). Raman spectra are consistent with the formation of NaHSO4 with no evidence for Na2SO4. The spectra indicate that the phase of NaHSO 4 varies with the amount of H2O in the H2SO 4. The reaction produces anhydrous β-NaHSO4 which undergoes a phase change to anhydrous α- NaHSO4. AFM measurements on NaCl (100) show the formation of two distinct types of NaHSO4 structures consistent in shape with α- NaHSO4 and β-NaHSO4 . Model sea salt particles were gown from solution to determine the surface Br/Cl of crystals grown from solution. These studies show surface Br concentration is 35 times that of the bulk concentration. This data is useful in the understanding of enhanced volatile Br compounds in the Arctic troposphere. Thin films of model polar stratospheric cloud (PSC) surfaces were studied in ultrahigh vacuum. Low temperature data show the preferential orientation of HNO3 on crystalline H2O

  20. Chiral symmetry restoration versus deconfinement in heavy-ion collisions at high baryon density

    NASA Astrophysics Data System (ADS)

    Cassing, W.; Palmese, A.; Moreau, P.; Bratkovskaya, E. L.

    2016-01-01

    We study the production of strange hadrons in nucleus-nucleus collisions from 4 to 160 A GeV within the parton-hadron-string dynamics (PHSD) transport approach that is extended to incorporate essentials aspects of chiral symmetry restoration (CSR) in the hadronic sector (via the Schwinger mechanism) on top of the deconfinement phase transition as implemented in PHSD. Especially the K+/π+ and the (Λ +Σ0) /π- ratios in central Au+Au collisions are found to provide information on the relative importance of both transitions. The modeling of chiral symmetry restoration is driven by the pion-nucleon Σ term in the computation of the quark scalar condensate that serves as an order parameter for CSR and also scales approximately with the effective quark masses ms and mq. Furthermore, the nucleon scalar density ρs, which also enters the computation of , is evaluated within the nonlinear σ -ω model which is constrained by Dirac-Brueckner calculations and low-energy heavy-ion reactions. The Schwinger mechanism (for string decay) fixes the ratio of strange to light quark production in the hadronic medium. We find that above ˜80 A GeV the reaction dynamics of heavy nuclei is dominantly driven by partonic degrees of freedom such that traces of the chiral symmetry restoration are hard to identify. Our studies support the conjecture of "quarkyonic matter" in heavy-ion collisions from about 5 to 40 A GeV and provide a microscopic explanation for the maximum in the K+/π+ ratio at about 30 A GeV, which only shows up if a transition to partonic degrees of freedom is incorporated in the reaction dynamics and is discarded in the traditional hadron-string models.

  1. Nuclear de-excitation processes following medium energy heavy ion collisions

    SciTech Connect

    Blann, M.

    1986-09-01

    As heavy ion reaction studies have progressed from beam energies below 10 MeV/nucleon to higher energies, many non-equilibrium reaction phenomena have been observed. Among these are nucleon emission with velocities in excess of the beam velocity, incomplete momentum transfer to evaporation residue and fission-like fragments, ..gamma..-rays with energies in excess of 100 MeV, and ..pi../sup 0/ production when beam energies are below the threshold for production by the nucleon-nucleon collision mechanism. Additionally, prefission neutrons have been observed in excess of numbers expected from equilibrium models. A few of the approaches which have been applied to these phenomena are as follows: Intranuclear cascade: two body collisions are assumed to mediate the equilibration. The geometry and momentum space is followed semiclassically. The approach has many successes though it may suffer in a few applications is not following holes; TDHF considers one body processes only; in the energy regime of interest, two body processes are important so that this may not be a viable approach; Boltzmann-Uehling-Uhlenbeck or Vlasov-Uehling-Uhlenbeck (BUU/VUU) equations combine both one body and two body dynamics. The spatial and momentum evolution of the reactions are followed in a mean field. These should be the Cadillacs of the models. They are computationally tedious, and sometimes significant approximations are made in order to achieve computational tract ability; models of collective deceleration. A very simple model approach is discussed to interpret these phenomena, the Boltzmann master equation (BME). The hybrid model was the first to be applied to the question of heavy ion precompound decay, and the BME second. 26 refs., 5 figs., 2 tabs.

  2. Modeling heavy ion ionization energy loss at low and intermediate energies

    SciTech Connect

    Rakhno, I.L.; /Fermilab

    2009-11-01

    The needs of contemporary accelerator and space projects led to significant efforts made to include description of heavy ion interactions with matter in general-purpose Monte Carlo codes. This paper deals with an updated model of heavy ion ionization energy loss developed previously for the MARS code. The model agrees well with experimental data for various projectiles and targets including super-heavy ions in low-Z media.

  3. Characterization of swift heavy ion irradiation damage in ceria

    SciTech Connect

    Yablinsky, Clarissa A.; Devanathan, Ram; Pakarinen, Janne; Gan, Jian; Severin, Daniel; Trautmann, Christina; Allen, Todd R.

    2015-03-04

    Swift heavy ion induced radiation damage is investigated for ceria (CeO2), which serves as a UO2 fuel surrogate. Microstructural changes resulting from an irradiation with 940 MeV gold ions of 42 keV/nm electronic energy loss are investigated by means of electron microscopy accompanied by electron energy loss spectroscopy showing that there exists a small density reduction in the ion track core. While chemical changes in the ion track are not precluded, evidence of them was not observed. Classical molecular dynamics simulations of thermal spikes in CeO2 with an energy deposition of 12 and 36 keV/nm show damage consisting of isolated point defects at 12 keV/nm, and defect clusters at 36 keV/nm, with no amorphization at either energy. Inferences are drawn from modeling about density changes in the ion track and the formation of interstitial loops that shed light on features observed by electron microscopy of swift heavy ion irradiated ceria.

  4. Characterization of swift heavy ion irradiation damage in ceria

    SciTech Connect

    Yablinsky, Clarissa; Devanathan, Ram; Pakarinen, Janne; Gan, Jian; Severin, Daniel; Trautmann, Christina; Allen, T. R.

    2015-05-14

    We have examined microstructural evolution in irradiated ceria (CeO2) using swift heavy ion irradiation, electron microscopy, and atomistic simulation. CeO2, a UO2 fuel surrogate, was irradiated with gold ions at an energy of 1 GeV to fluences up to 1x1014 ions/cm2. Transmission electron microscopy accompanied by electron energy loss spectroscopy showed that the ion tracks were of similar size at all fluences, and that there was no chemical change in the ion track core. Classical molecular dynamics simulations of thermal spikes in CeO2 with energy deposition of 12 and 36 keV/nm show damage consisting of isolated point defects at the lower energy and defect clusters at 36 keV/nm, with no amorphization at either energy. Inferences are drawn from modeling about density changes in the ion track and the formation of interstitial loops that shed light on features observed by electron microscopy of swift heavy ion irradiated ceria.

  5. Late degeneration in rabbit tissues after irradiation by heavy ions

    NASA Technical Reports Server (NTRS)

    Lett, J. T.; Cox, A. B.; Keng, P. C.; Lee, A. C.; Su, C. M.; Bergtold, D. S.

    1980-01-01

    Results are presented for investigations of the late effects of heavy-ion irradiation on rabbit tissues which were undertaken to assess the hazards associated with the long-term exposure of humans to heavy ions in space during such activities as the construction of solar power stations or voyages to Mars. White rabbits approximately six weeks old were exposed to various doses of collimated beams of 400-MeV/n Ne ions, 570 MeV/n Ar ions and Co-60 gamma rays directed through both eyes, and the responses of the various tissues (hair follicles, skin, cornea, lens, retina, Harderian glands, bone and forebrain) were examined. Proliferating tissues are found to exhibit high damage levels in the early and late periods following irradiation, while terminally differentiating tissues repond to radiation most intensely in the late period, years after irradiation, with no intermediate recovery. The results obtained from rabbits are used to predict the occurrence of late tissue degeneration in the central nervous system, terminally differentiating systems and stem cells of humans one or more decades following exposure to radiation levels anticipated during long-duration space flights. The studies also indicate that tissues may be prematurely aged in the sense that tissue life spans may be shortened without the development of malignancies.

  6. Torqued fireballs in relativistic heavy-ion collisions

    SciTech Connect

    Bozek, Piotr; Broniowski, Wojciech; Moreira, Joao

    2011-03-15

    We show that the fluctuations in the wounded-nucleon model of the initial stage of relativistic heavy-ion collisions, together with the natural assumption that the forward- (backward-) moving wounded nucleons emit particles preferably in the forward (backward) direction, lead to an event-by-event torqued fireball. The principal axes associated with the transverse shape are rotated in the forward region in the opposite direction than in the backward region. On the average, the standard deviation of the relative torque angle between the forward and backward rapidity regions is {approx}20 deg. for the central and 10 deg. for the midperipheral collisions. The hydrodynamic expansion of a torqued fireball leads to a torqued collective flow, yielding, in turn, torqued principal axes of the transverse-momentum distributions at different rapidities. We propose experimental measures, based on cumulants involving particles in different rapidity regions, which should allow for a quantitative determination of the effect from the data. To estimate the nonflow contributions from resonance decays we run Monte Carlo simulations with therminator, a thermal heavy-ion generator. If the event-by-event torque effect is found in the data, it will support the assumptions concerning the fluctuations in the early stage of the fireball formation, as well as the hypothesis of the asymmetric rapidity shape of the emission functions of the moving sources in the nucleus-nucleus collisions.

  7. Modeling Electron-Cloud Effects in Heavy-Ion Accelerators

    SciTech Connect

    Cohen, R H; Friedman, A; Lund, S M; Molvik, A W; Lee, E P; Azevedo, T; Vay, J; Stoltz, P; Veitzer, S

    2004-09-21

    Stray electrons can arise in positive-ion accelerators for heavy ion fusion or other applications as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary- electron emission. We summarize results from several studies undertaken in conjunction with an effort to develop a self-consistent modeling capability: (1) Calculation of the electron cloud produced by electron desorption from computed beam-ion loss, which illustrates the importance of retaining ion reflection at the walls; (2) Simulation of the effect of specified electron cloud distributions on ion beam dynamics; and (3) analysis of an instability associated with a resonance between the beam-envelope ''breathing'' mode and the electron perturbation. We also report first results from a long-timestep algorithm for electron dynamics, which holds promise for efficient simultaneous solution of electron and ion dynamics. One conclusion from study (2) is that heavy-ion beams are surprisingly robust to electron clouds, compared to a priori expectations.

  8. Heavy-ion induced genetic changes and evolution processes

    NASA Astrophysics Data System (ADS)

    Yang, C. H.; Craise, L. M.; Durante, M.; Mei, M.

    1994-10-01

    On Moon and Mars, there will be more galactic cosmic rays and higher radiation doses than on earth. Our experimental studies showed that heavy ion radiation can effectively cause mutation and chromosome aberrations and that high-LET heavy-ion induced mutants can be irreversible. Chromosome translocations and deletions are common in cells irradiated by heavy particles, and ionizing radiations are effective in causing hyperploidy. The importance of the genetic changes in the evolution of life is an interesting question. Through evolution, there is an increase of DNA content in cells from lower forms of life to higher organisms. The DNA content, however, reached a plateau in vertebrates. By increasing DNA content, there can be an increase of information in the cell. For a given DNA content, the quality of information can be changed by rearranging the DNA. Because radiation can cause hyperploidy, an increase of DNA content in cells, and can induce DNA rearrangement, it is likely that the evolution of life on Mars will be effected by its radiation environment. A simple analysis shows that the radiation level on Mars may cause a mutation frequency comparable to that of the spontaneous mutation rate on Earth. To the extent that mutation plays a role in adaptation, radiation alone on Mars may thus provide different mutation for the evolution of life.

  9. Electron-Cloud Effects on Heavy-Ion Beams

    SciTech Connect

    Azevedo, T; Friedman, A; Cohen, R; Vay, J

    2004-03-29

    Stray electrons can be introduced in positive-charge accelerators for heavy ion fusion (or other applications) as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. We are developing a capability for self-consistent simulation of ion beams with the electron clouds they produce. We report on an ingredient in this capability, the effect of specified electron cloud distributions on the dynamics of a coasting ion beam. We consider here electron distributions with axially varying density, centroid location, or radial shape, and examine both random and sinusoidally varying perturbations. We find that amplitude variations are most effective in spoiling ion beam quality, though for sinusoidal variations which match the natural ion beam centroid oscillation or breathing mode frequencies, the centroid and shape perturbations can also be effective. We identify a possible instability associated with resonance with the beam-envelope ''breathing'' mode. One conclusion from this study is that heavy-ion beams are surprisingly robust to electron clouds, compared to a priori expectations.

  10. Heavy ion induced double strand breaks in bacteria and bacteriophages

    NASA Astrophysics Data System (ADS)

    Micke, U.; Schäfer, M.; Anton, A.; Horneck, G.; Bücker, H.

    DNA damage induced by heavy ions in bacterial cells and bacteriophages such as Bacillus subtilis, E. coli and Bacteriophage Tl were investigated by analyzing the double strand breaks in the chromosomal DNA. This kind of lesion is considered as one of the main reasons for lethal events. To analyze double strand breaks in long molecules of DNA - up to some Mbp in length - the technique of pulse field agarose gel electrophoresis has been used. This allows the detection of one double strand break per genome. Cell lysis and DNA isolation were performed in small agarose blocks directly. This procedure secured minimum DNA destruction by shearing forces. After running a gel, the DNA was stained with ethidium bromide. The light intensity of ethidium bromide fluorescence for both the outcoming (running) DNA and the remaining intact DNA were measured by scanning. The mean number of double strand breaks was calculated by determining the quotient of these intensities. Strand break induction after heavy ion and X-ray irradiation was compared.

  11. The composition of heavy ions in solar energetic particle events

    NASA Technical Reports Server (NTRS)

    Fan, C. Y.; Gloeckler, G.; Hovestadt, D.

    1983-01-01

    Recent advances in determining the elemental, charge state, and isotopic composition of or approximate to 1 to or approximate to 20 MeV per nucleon ions in solar energetic particle (SEP) events and outline our current understanding of the nature of solar and interplanetary processes which may explain the observations. Average values of relative abundances measured in a large number of SEP events were found to be roughly energy independent in the approx. 1 to approx. 20 MeV per nucleon range, and showed a systematic deviation from photospheric abundances which seems to be organized in terms of the first ionization potential of the ion. Direct measurements of the charge states of SEPs revealed the surprisingly common presence of energetic He(+) along with heavy ion with typically coronal ionization states. High resolution measurements of isotopic abundance ratios in a small number of SEP events showed these to be consistent with the universal composition except for the puzzling overabundance of the SEP(22)Ne/(20)Ne relative to this isotopes ratio in the solar wind. The broad spectrum of observed elemental abundance variations, which in their extreme result in composition anomalies characteristic of (3)He rich, heavy ion rich and carbon poor SEP events, along with direct measurements of the ionization states of SEPs provided essential information on the physical characteristics of, and conditions in the source regions, as well as important constraints to possible models for SEP production.

  12. Heavy Ion Radiation Effects Studies With Ion Photon Emission Microscopy

    SciTech Connect

    Branson, J. V.; Hattar, K.; Vizkelethy, G.; Powell, C. J.; Doyle, B. L.; Rossi, P.

    2011-06-01

    The development of a new radiation effects microscopy (REM) technique is crucial as emerging semiconductor technologies demonstrate smaller feature sizes and thicker back end of line (BEOL) layers. To penetrate these materials and still deposit sufficient energy into the device to induce single event effects, high energy heavy ions are required. Ion photon emission microscopy (IPEM) is a technique that utilizes coincident photons, which are emitted from the location of each ion impact to map out regions of radiation sensitivity in integrated circuits and devices, circumventing the obstacle of focusing high-energy heavy ions. Several versions of the IPEM have been developed and implemented at Sandia National Laboratories (SNL). One such instrument has been utilized on the microbeam line of the 6 MV tandem accelerator at SNL. Another IPEM was designed for ex-vacu use at the 88'' cyclotron at Lawrence Berkeley National Laboratory (LBNL). Extensive engineering is involved in the development of these IPEM systems, including resolving issues with electronics, event timing, optics, phosphor selection, and mechanics. The various versions of the IPEM and the obstacles, as well as benefits associated with each will be presented. In addition, the current stage of IPEM development as a user instrument will be discussed in the context of recent results.

  13. Characterization of swift heavy ion irradiation damage in ceria

    DOE PAGESBeta

    Yablinsky, Clarissa A.; Devanathan, Ram; Pakarinen, Janne; Gan, Jian; Severin, Daniel; Trautmann, Christina; Allen, Todd R.

    2015-03-04

    Swift heavy ion induced radiation damage is investigated for ceria (CeO2), which serves as a UO2 fuel surrogate. Microstructural changes resulting from an irradiation with 940 MeV gold ions of 42 keV/nm electronic energy loss are investigated by means of electron microscopy accompanied by electron energy loss spectroscopy showing that there exists a small density reduction in the ion track core. While chemical changes in the ion track are not precluded, evidence of them was not observed. Classical molecular dynamics simulations of thermal spikes in CeO2 with an energy deposition of 12 and 36 keV/nm show damage consisting of isolatedmore » point defects at 12 keV/nm, and defect clusters at 36 keV/nm, with no amorphization at either energy. Furthermore, inferences are drawn from modeling about density changes in the ion track and the formation of interstitial loops that shed light on features observed by electron microscopy of swift heavy ion irradiated ceria.« less

  14. Nonuniformity Mitigation of Beam Illumination in Heavy Ion Inertial Fusion

    NASA Astrophysics Data System (ADS)

    Kawata, Shigeo; Noguchi, K.; Suzuki, T.; Kurosaki, T.; Barada, D.; Ma, Y. Y.; Ogoyski, A. I.

    2013-10-01

    In heavy ion inertial fusion wobbling heavy ion beam (HIB) illumination was proposed to realize a uniform implosion. The wobbling HIB axis oscillation is precisely controlled. The oscillating frequency may be several 100 MHz ~ 1 GHz. In the wobbling HIBs illumination, the illumination nonuniformity oscillates in time and space on a HIF target. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs' illumination nonuniformity. Three-dimensional HIBs illumination computations presented here show that the few percent wobbling HIBs illumination nonuniformity oscillates with the same wobbling HIBs frequency. In general a perturbation of physical quantity would feature the instability onset. Normally the perturbation phase is unknown so that the instability growth is discussed with the growth rate. However, if the perturbation phase is known, the instability growth can be controlled by a superposition of perturbations; the well-known mechanism is a feedback control to compensate the displacement of physical quantity. If the perturbation is induced by, for example, a HIB axis wobbling, the perturbation phase could be controlled and the instability growth is mitigated by the superposition of the growing perturbations. Partly supported by JSPS, MEXT, CORE, ASHULA, Japan / US Cooperation program and ILE/Osaka University.

  15. Spiral wobbling beam illumination uniformity in Heavy Ion Fusion

    NASA Astrophysics Data System (ADS)

    Kawata, S.; Kurosaki, T.; Koseki, S.; Hisatomi, Y.; Barada, D.; Ogoyski, A. I.; Logan, B. G.; Barnard, J.

    2011-10-01

    A new beam illumination scheme has been found, in which a few per cent beam illumination nonuniformity is realized for a spiraling and ``wobbling'' beam in a heavy ion inertial confinement fusion (HIF) driver. The oscillating-HIB (heavy ion beam) energy deposition may produce a time-dependent implosion acceleration, which reduces both the Rayleigh-Taylor (R-T) growth [NIMA 606, 152(2009)] and the implosion nonuniformity. Three-dimensional HIB illumination computations indicate that the few per cent spiral-wobbling HIB illumination nonuniformity oscillates with the same wobbling HIB frequency. In HIF, HIB axes can be controlled precisely with a high frequency (100MHz ~ 1GHz) centroid oscillation about the axis. This oscillating HIB creates a small oscillating energy deposition in time and space. This small oscillating nonuniformity can produce a small oscillating implosion acceleration nonuniformity. When the oscillation frequency is comparable to or larger than the R-T growth rate, it reduces the R-T growth significantly. This work is partly supported by MEXT, JSPS, ILE/Osaka Univ. and CORE (Center for Optical Research and Education, Utsunomiya Univ., Japan).

  16. Robust beam illumination in heavy ion inertial fusion

    NASA Astrophysics Data System (ADS)

    Kawata, Shigeo; Miyazawa, K.; Someya, T.; Kikuchi, T.; Ogoyski, A. I.

    2006-10-01

    In this paper an optimized new HIB illumination scheme is presented in order to realize a robust illumination scheme against a displacement of a direct-driven fuel pellet in an ICF reactor. In heavy ion inertial fusion (HIF) heavy ion beam (HIB) precise illumination is essentially important to obtain a sufficient fusion energy output. In direct-driven pellet implosion, HIBs illuminate a spherical target and the HIB deposition non-uniformity should be suppressed less than a few %. In our study, we developed a 3D HIB illumination code [1] and a hydrodynamic implosion code for HIF studies. We have obtained an optimal HIB illumination scheme to minimize the HIB illumination non-uniformity on a direct-driven fuel pellet and to make the illumination scheme robust against a little pellet displacement dz in a fusion reactor chamber. The optimized HIB illumination scheme allows 200-300 [micron m] of dz in HIF [2]. [1] T. Someya, et.al, Phy.Rev.STAB, 7, 044701 (2004). [2] S. Miyazawa, et al., Phys. of Plasma, 12, 122702 (2005)

  17. Modeling Chamber Transport for Heavy-Ion Fusion

    SciTech Connect

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

    2002-08-02

    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.

  18. Modeling chamber transport for heavy-ion fusion

    SciTech Connect

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

    2002-10-01

    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.

  19. A Compact High-Brightness Heavy-Ion Injector

    SciTech Connect

    Westenskow, G A; Grote, D P; Halaxa, E; Kwan, J W; Bieniosek, F

    2005-05-11

    To provide a compact high-brightness heavy-ion beam source for Heavy Ion Fusion (HIF) accelerators, we have been experimenting with merging multi-beamlets in an injector which uses an RF plasma source. In an 80-kV 20-microsecond experiment, the RF plasma source has produced up to 5 mA of Ar{sup +} in a single beamlet. An extraction current density of 100 mA/cm{sup 2} was achieved, and the thermal temperature of the ions was below 1 eV. We have tested at full voltage gradient the first 4 gaps of an injector design. Einzel lens were used to focus the beamlets while reducing the beamlet to beamlet space charge interaction. We were able to reach greater than 100 kV/cm in the first four gaps. We also performed experiments on a converging 119 multi-beamlet source. Although the source has the same optics as a full 1.6 MV injector system, these test were carried out at 400 kV due to the test stand HV limit. We have measured the beam's emittance after the beamlets are merged and passed through an electrostatic quadrupole (ESQ). Our goal is to confirm the emittance growth and to demonstrate the technical feasibility of building a driver-scale HIF injector.

  20. The composition of heavy ions in solar energetic particle events

    NASA Technical Reports Server (NTRS)

    Fan, C. Y.; Gloeckler, G.; Hovestadt, D.

    1984-01-01

    Recent advances in determining the elemental, charge state, and isotopic composition of or approximate to 1 to or approximate to 20 MeV per nucleon ions in solar energetic particle (SEP) events and outline our current understanding of the nature of solar and interplanetary processes which may explain the observations. Average values of relative abundances measured in a large number of SEP events were found to be roughly energy independent in the approx. 1 to approx. 20 MeV per nucleon range, and showed a systematic deviation from photospheric abundances which seems to be organized in terms of the first ionization potential of the ion. Direct measurements of the charge states of SEPs revealed the surprisingly common presence of energetic He(+) along with heavy ion with typically coronal ionization states. High resolution measurements of isotopic abundance ratios in a small number of SEP events showed these to be consistent with the universal composition except for the puzzling overabundance of the SEP(22)Ne/(20)Ne relative to this isotopes ratio in the solar wind. The broad spectrum of observed elemental abundance variations, which in their extreme result in composition anomalies characteristic of (3)He rich, heavy ion rich and carbon poor SEP events, along with direct measurements of the ionization states of SEPs provided essential information on the physical characteristics of, and conditions in the source regions, as well as important constraints to possible models for SEP production. Previously announced in STAR as N83-20886

  1. Characterization of swift heavy ion irradiation damage in ceria

    SciTech Connect

    Yablinsky, Clarissa A.; Devanathan, Ram; Pakarinen, Janne; Gan, Jian; Severin, Daniel; Trautmann, Christina; Allen, Todd R.

    2015-03-04

    Swift heavy ion induced radiation damage is investigated for ceria (CeO2), which serves as a UO2 fuel surrogate. Microstructural changes resulting from an irradiation with 940 MeV gold ions of 42 keV/nm electronic energy loss are investigated by means of electron microscopy accompanied by electron energy loss spectroscopy showing that there exists a small density reduction in the ion track core. While chemical changes in the ion track are not precluded, evidence of them was not observed. Classical molecular dynamics simulations of thermal spikes in CeO2 with an energy deposition of 12 and 36 keV/nm show damage consisting of isolated point defects at 12 keV/nm, and defect clusters at 36 keV/nm, with no amorphization at either energy. Furthermore, inferences are drawn from modeling about density changes in the ion track and the formation of interstitial loops that shed light on features observed by electron microscopy of swift heavy ion irradiated ceria.

  2. Experiments at The Virtual National Laboratory for Heavy Ion Fusion

    SciTech Connect

    Seidl, P.A.; Bieniosek, F.M.; Celata, C.M.; Faltens, A.; Kwan, J.W.; MacLaren, S.A.; Ponce, D.; Shuman, D.; Yu, S.; Ahle, L.; Lund, S.; Molvik, A.; Sangster, T.C.

    2000-07-24

    An overview of experiments is presented, in which the physical dimensions, emittance and perveance are scaled to explore driver-relevant beam dynamics. Among these are beam merging, focusing to a small spot, and bending and recirculating beams. The Virtual National Laboratory for Heavy Ion Fusion (VNL) is also developing two driver-scale beam experiments involving heavy-ion beams with I(sub beam) about 1 Ampere to provide guidance for the design of an Integrated Research Experiment (IRE) for driver system studies within the next 5 years. Multiple-beam sources and injectors are being designed and a one-beam module will be built and tested. Another experimental effort will be the transport of such a beam through about 100 magnetic quadrupoles. The experiment will determine transport limits at high aperture fill factors, beam halo formation, and the influence on beam properties of secondary electron Research into driver technology will be briefly presented, including the development of ferromagnetic core materials, induction core pulsers, multiple-beam quadrupole arrays and plasma channel formation experiments for pinched transport in reactor chambers.

  3. Heavy-ion induced genetic changes and evolution processes

    NASA Technical Reports Server (NTRS)

    Yang, C. H.; Craise, L. M.; Durante, M.; Mei, M.

    1994-01-01

    On Moon and Mars, there will be more galactic cosmic rays and higher radiation doses than on Earth. Our experimental studies showed that heavy ion radiation can effectively cause mutation and chromosome aberrations and that high Linear Energy Transfer (LET) heavy-ion induced mutants can be irreversible. Chromosome translocations and deletions are common in cells irradiated by heavy particles, and ionizing radiations are effective in causing hyperploidy. The importance of the genetic changes in the evolution of life is an interesting question. Through evolution, there is an increase of DNA content in cells from lower forms of life to higher organisms. The DNA content, however, reached a plateau in vertebrates. By increasing DNA content, there can be an increase of information in the cell. For a given DNA content, the quality of information can be changed by rearranging the DNA. Because radiation can cause hyperploidy, an increase of DNA content in cells, and can induce DNA rearrangement, it is likely that the evolution of life on Mars will be effected by its radiation environment. A simple analysis shows that the radiation level on Mars may cause a mutation frequency comparable to that of the spontaneous mutation rate on Earth. To the extent that mutation plays a role in adaptation, radiation alone on Mars may thus provide sufficient mutation for the evolution of life.

  4. RELATIVISTIC HEAVY ION PHYSICS : RESULTS FROM AGS TO RHIC.

    SciTech Connect

    STEINBERG,P.

    2002-06-20

    High-energy collisions of heavy ions provide a means to study QCD in a regime of high parton density, and may provide insight into its phme structure. Results from the four experiments at RHIC (BRAHMS, PHENIX, PHOBOS and STAR) are presented, and placed in context with the lower energy data from the AGS and SPS accelerators. The focus is on the insights these measurements provide into the time history of the collision process. Taken together, the data point to the creation of a deconfined state of matter that forms quickly, expands rapidly and freezes out suddenly. With the new RHIC data, systematic data now exists for heavy ion collisions as a function of {radical}s over several orders of magnitude and as a function of impact parameter. These data test the interplay between hard and soft processes in a large-volume system where nucleons are struck multiple times. The data is consistent with creating a deconfined state (jet quenching) that forms quickly (saturation models), expands rapidly (radial and elliptic flow) and freezes out suddenly (single freezeout and blast wave fits). There are also intriguing connections with particle production in elementary systems, which point to the role of the energy available for particle production on the features of the final state. Many in this field are optimistic that the careful understanding of this experimental data may lead t o the theoretical breakthroughs that will connect these complex systems to the fundamental lattice predict ions.

  5. Systematics of heavy-ion charge-exchange straggling

    NASA Astrophysics Data System (ADS)

    Sigmund, P.; Schinner, A.

    2016-10-01

    The dependence of heavy-ion charge-exchange straggling on the beam energy has been studied theoretically for several ion-target combinations. Our previous work addressed ions up to krypton, while the present study focuses on heavier ions, especially uranium. Particular attention has been paid to a multiple-peak structure which has been predicted theoretically in our previous work. For high-Z1 and high-Z2 systems, exemplified by U in Au, we identify three maxima in the energy dependence of charge-exchange straggling, while the overall magnitude is comparable with that of collisional straggling. Conversely, for U in C, charge-exchange straggling dominates, but only two peaks lie in the energy range where we presently are able to produce credible predictions. For U-Al we find good agreement with experiment in the energy range around the high-energy maximum. The position of the high-energy peak - which is related to processes in the projectile K shell - is found to scale as Z12 , in contrast to the semi-empirical Z13/2 dependence proposed by Yang et al. Measurements for heavy ions in heavy targets are suggested in order to reconcile a major discrepancy between the present calculations and the frequently-used formula by Yang et al.

  6. Progress in heavy-ion drivers for inertial fusion

    SciTech Connect

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

    1994-12-22

    Heavy-ion induction accelerators are being developed as fusion drivers for ICF power production in the US Inertial Fusion Energy (IFE) program, in the Office of Fusion Energy of the US Department of Energy. In addition, they represent an attractive driver option for a high-yield microfusion facility for defense research. This paper describes recent progress in induction drivers for Heavy-Ion Fusion (HIF), and plans for future work. It presents research aimed at developing drivers having reduced cost and size, specifically advanced induction linacs and recirculating induction accelerators (recirculators). The goals and design of the Elise accelerator being built at Lawrence Berkeley Laboratory (LBL), as the first stage of the ILSE (Induction Linac Systems Experiments) program, are described. Elise will accelerate, for the first time, space-charge-dominated ion beams which are of full driver scale in line-charge density and diameter. Elise will be a platform on which the critical beam manipulations of the induction approach can be explored. An experimental program at Lawrence Livermore National Laboratory (LLNL) exploring the recirculator principle on a small scale is described in some detail; it is expected that these studies will result ultimately in an operational prototype recirculating induction accelerator. In addition, other elements of the US HIF program are described.

  7. Self-aligned nanostructures created by swift heavy ion irradiation

    SciTech Connect

    Gehrke, Hans-Gregor; Nix, Anne-Katrin; Hofsaess, Hans; Krauser, Johann; Trautmann, Christina; Weidinger, Alois

    2010-05-15

    In tetrahedral amorphous carbon (ta-C) swift heavy ions create conducting tracks of about 8 nm in diameter. To apply these nanowires and implement them into nanodevices, they have to be contacted and gated. In the present work, we demonstrate the fabrication of conducting vertical nanostructures in ta-C together with self-aligned gate electrodes. A multilayer assembly is irradiated with GeV heavy ions and subsequently exposed to several selective etching processes. The samples consist of a Si wafer as substrate covered by a thin ta-C layer. On top is deposited a SiN{sub x} film for insulation, a Cr layer as electrode, and finally a polycarbonate film as ion track template. Chemical track etching opens nanochannels in the polymer which are self-aligned with the conducting tracks in ta-C because they are produced by the same ions. Through the pores in the polymer template, the Cr and SiN{sub x} layers are opened by ion beam sputtering and plasma etching, respectively. The resulting structure consists of nanowires embedded in the insulating carbon matrix with a built in gate electrode and has potential application as gated field emission cathode.

  8. Energy loss of heavy ions at high velocity

    NASA Astrophysics Data System (ADS)

    Andersen, J. U.; Ball, G. C.; Davies, J. A.; Davies, W. G.; Forster, J. S.; Geiger, J. S.; Geissel, H.; Ryabov, V. A.

    1994-05-01

    The slowing down of heavy ions by electronic stopping at high velocity is discussed. The ions are nearly fully stripped and have a well defined charge with relatively small fluctuations. Owing to the large charge of the ions, the classical Bohr formula applies instead of the Bethe formula, which is based on a quantum perturbation calculation. It is essential to include the Barkas effect in the description since it becomes quite large for heavy ions, especially in high-Z materials. In Lindhard's treatment [Nucl. Instr. and Meth. 132 (1976) l], the Barkas correction is viewed as an effect of dynamic screening of the ion potential in the initial phase of a collision with an electron, which reduces the relative velocity and therefore enhances the cross section. With inclusion of this enhancement factor for all impact parameters, as evaluated by Jackson and McCarthy for distant collisions [Phys. Rev. B 6 (1972) 4131], the description reproduces within a few percent measurements for 15 MeV/u Br on Si, Ni, and Au and for 10 MeV/u Kr on Al, Ni, and Au. The procedure is shown also to apply at lower velocities near the stopping maximum, albeit with less accuracy. The straggling in energy loss has been analyzed for a measurement on Si and it is well described by a combination of about equal contributions from fluctuations in the number of violent collisions with single electrons (Bohr straggling) and from fluctuations in ion charge state.

  9. Electrostatic solitary wave and double layer in a plasma with heavy ions and nonthermally distributed electrons

    SciTech Connect

    Choi, C.-R.; Min, K.-W.; Woo, M.-H.; Ryu, C.-M.

    2010-09-15

    The existence condition for bump and dip type, as well as double layer (DL), solutions of electrostatic solitary waves (ESWs) in a nonthermal electron plasma with heavy ions is investigated by a pseudopotential method. It is found that the nonthermality of electrons determines the existence of the DL solution and that the amplitude of ESWs is enhanced by the density of heavy ions. When the heavy ion density is beyond a certain critical value, ESWs and DLs cannot exist. It is also found that both the lower and upper critical Mach numbers are reduced by the presence of heavy ions.

  10. Effects of radical scavengers on aqueous solutions exposed to heavy-ion irradiation using the liquid microjet technique

    NASA Astrophysics Data System (ADS)

    Nomura, Shinji; Tsuchida, Hidetsugu; Furuya, Ryousuke; Miyahara, Kento; Majima, Takuya; Itoh, Akio

    2015-12-01

    The effects of the radical scavenger ascorbic acid on water radiolysis are studied by fast heavy-ion irradiation of aqueous solutions of ascorbic acid, using the liquid microjet technique under vacuum. To understand the reaction mechanisms of hydroxyl radicals in aqueous solutions, we directly measure secondary ions emitted from solutions with different ascorbic acid concentrations. The yield of hydronium secondary ions is strongly influenced by the reaction between ascorbic acid and hydroxyl radicals. From analysis using a simple model considering chemical equilibria, we determine that the upper concentration limit of ascorbic acid with a radical scavenger effect is approximately 70 μM.

  11. Heavy ion initial conditions and correlations between higher moments in the spatial anisotropy

    SciTech Connect

    Nagle, J. L.; McCumber, M. P.

    2011-04-15

    Fluctuations in the initial conditions for relativistic heavy ion collisions are proving to be crucial to understanding final state flow and jet quenching observables. The initial geometry has been parametrized in terms of moments in the spatial anisotropy (i.e., {epsilon}{sub 2},{epsilon}{sub 3},{epsilon}{sub 4},{epsilon}{sub 5},...), and it has been stated in multiple published articles that the vector directions of odd moments are uncorrelated with the even moments and the reaction place angle. In this article, we demonstrate that this is incorrect and that a substantial nonzero correlation exists between the even and odd moments in peripheral Au+Au collisions. These correlations persist for all centralities, though at a very small level for the 0-55% most central collisions.

  12. Azimuthal anisotropy at the relativistic heavy ion collider: the first and fourth harmonics.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Ganti, M S; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Gutierrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, D A; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; de Toledo, A Szanto; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2004-02-13

    We report the first observations of the first harmonic (directed flow, v(1)) and the fourth harmonic (v(4)), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v(2)) generated at RHIC. From the correlation of v(2) with v(1) it is determined that v(2) is positive, or in-plane. The integrated v(4) is about a factor of 10 smaller than v(2). For the sixth (v(6)) and eighth (v(8)) harmonics upper limits on the magnitudes are reported. PMID:14995231

  13. Irradiation of nuclear track emulsions with thermal neutrons, heavy ions, and muons

    SciTech Connect

    Artemenkov, D. A. Bradnova, V.; Zaitsev, A. A.; Zarubin, P. I.; Zarubina, I. G.; Kattabekov, R. R.; Mamatkulov, K. Z.; Rusakova, V. V.

    2015-07-15

    Exposures of test samples of nuclear track emulsion were analyzed. Angular and energy correlations of products originating from the thermal-neutron-induced reaction n{sub th} +{sup 10} B → {sup 7} Li + (γ)+ α were studied in nuclear track emulsions enriched in boron. Nuclear track emulsions were also irradiated with {sup 86}Kr{sup +17} and {sup 124}Xe{sup +26} ions of energy about 1.2 MeV per nucleon. Measurements of ranges of heavy ions in nuclear track emulsionsmade it possible to determine their energies on the basis of the SRIM model. The formation of high-multiplicity nuclear stars was observed upon irradiating nuclear track emulsions with ultrarelativistic muons. Kinematical features studied in this exposure of nuclear track emulsions for events of the muon-induced splitting of carbon nuclei to three alpha particles are indicative of the nucleardiffraction interaction mechanism.

  14. Pairing energy of fragments produced in intermediate-energy heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Ma, Chun-Wang; Niu, Fei; Qiao, Chun-Yuan; Niu, Yi-Fei; Yan, Ting-Zhi

    2016-08-01

    The pairing energy (Ep) of fragments, which is assumed to have a finite temperature in heavy-ion collisions, is obtained using an isobaric yield ratio method in the framework of a modified Fisher model. The fragments in the measured and simulated 140 A MeV Ca,4840+9Be/181Ta and Ni,6458+9Be/181Ta reactions have been adopted to perform the analysis. The results show that the ratio of the pairing-energy coefficient to the temperature (ap/T ) is not significantly influenced by the reaction system, but depends on the neutron excess (I =N -Z ) of the fragment. For most fragments, ap/T falls in the range of -1.0 heavy-ion collisions.

  15. Helium and heavy ion measurements with the CRRES satellite

    NASA Astrophysics Data System (ADS)

    Clayton, Edmund Gary

    The CRRES satellite was in service from July 1990 to October 1991, during a period of high solar modulation and solar activity. The ONR-604 experiment aboard CRRES measured helium with isotopic resolution in the energy range 38-110 MeV/nucleon, and heavy ions through iron at 200-500 MeV/nucleon. Although solar modulation was high throughout the CRRES mission, the mission included periods of solar quiescence as well as a number of large solar flares and associated solar energetic particle events. Measurements were made of helium and heavy ions during both the quiet times and the flare periods. A study was made to search for anomalous component helium in the Earth's magnetosphere using the magnetic field as a rigidity filter. This effort was inconclusive due to background in the outer electron radiation belt. During the solar quiet times, the helium spectrum above 60 MeV/nucleon is consistent with the galactic cosmic rays. Below that energy, a separate component appears early in the mission and rises in prominence over the course of the mission, dominating over the galactic cosmic rays below 60 MeV/nucleon. The distinctness of this component is seen both in the helium spectra and the 3He/4He ratio. An association of this component with interplanetary shocks driven by coronal mass ejections is suggested. During the March and June 1991 flare periods, helium spectral characteristics and isotopic ratios are measured. The results are compared to related diagnostic phenomena of gradual and impulsive solar energetic particle acceleration. The average 3He/4He ratio in both periods is enriched relative to the solar wind; 0.01 in June 1991 and 0.07 in March. The March period contains spikes in the isotopic ratio rising to 0.22. Signatures of known solar phenomena are compared to attempt to identify the predominant acceleration mechanism of each major flare. The development of the CRRES/SPACERAD Heavy Ion Model of the Environment (CHIME) is described and the results presented.

  16. Mutation induction in bacteria after heavy ion irradiation

    NASA Technical Reports Server (NTRS)

    Horneck, G.; Kozubek, S.

    1994-01-01

    From a compilation of experimental data on the mutagenic effects of heavy ions in bacteria, main conclusions have been drawn as follows: (1) The mutagenic efficacy of heavy ions in bacteria depends on physical and biological variables. Physical variables are the radiation dose, energy and charge of the ion; the biological variables are the bacterial strain, the repair genotype of bacteria, and the endpoint investigated (type of mutation, induction of enzymes related to mutagenesis); (2) The responses on dose or fluence are mainly linear or linear quadratic. The quadratic component, if found for low LET radiation, is gradually reduced with increasing LET; (3) At low values of Z and LET the cross section of mutation induction sigma m (as well as SOS response, sigma sos. and lambda phage induction, sigma lambda versus LET curves can be quite consistently described by a common function which increases up to approximately 100 keV/mu m. For higher LET values, the sigma(m) versus LET curves show the so-called 'hooks' observed also for other endpoints; (4) For light ions (Z is less than or equal to 4), the cross sections mostly decrease with increasing ion energy, which is probably related to the decrease of the specific energy departed by the ion inside the sensitive volume (cell). For ions in the range of Z = 10, sigma(m) is nearly independent on the ion energy. For heavier ions (Z is greater than or equal to 16), sigma(m) increases with the energy up to a maximum or saturation around 10 MeV/u. The increment becomes steeper with increasing atomic number of the ion. It correlates with the increasing track radius of the heavy ion; (5) The mutagenic efficiency per lethal event changes slightly with ion energy, if Z is small indicating a rough correlation between cellular lethality and mutation induction, only. For ions of higher Z this relation increases with energy, indicating a change in the 'mode' of radiation action from 'killing-prone' to 'mutation-prone'; and (6

  17. Light and heavy ion beam analysis of thin biological sections

    NASA Astrophysics Data System (ADS)

    Lee, Joonsup; Siegele, Rainer; Pastuovic, Zeljko; Hackett, Mark J.; Hunt, Nicholas H.; Grau, Georges E.; Cohen, David D.; Lay, Peter A.

    2013-07-01

    The application of ion beam analysis (IBA) techniques to thin biological sections (ThBS) presents unique challenges in sample preparation, data acquisition and analysis. These samples are often the end product of expensive, time-consuming experiments, which involve many steps that require careful attention. Analysis via several techniques can maximise the information that is collected from these samples. Particle-induced X-ray emission (PIXE) and Rutherford backscattering (RBS) spectroscopy are two generally non-destructive IBA techniques that use the same MeV ions and can be performed simultaneously. The use of heavy ion PIXE applied to thick samples has, in the past, resulted in X-ray spectra of a poorer quality when compared to those obtained with proton beams. One of the reasons for this is the shorter probing depth of the heavy ions, which does not affect thin sample analysis. Therefore, we have investigated and compared 3-MeV proton and 36-MeV carbon ion beams on 7-μm thick mouse brain sections at the ANSTO Heavy ion microprobe (HIMP). The application of a 36-MeV C4+ ion beam for PIXE mapping of ThBS on thin Si3N4 substrate windows produced spectra of high quality that displayed close to a nine-times gain in signal yield (Z2/q) when compared to those obtained for 3-MeV protons for P, S, Cl and K but not for Fe, Cu and Zn. Image quality was overall similar; however, some elements showed better contrast and features with protons whilst others showed improved contrast with a carbon ion beam. RBS spectra with high enough counting statistics were easily obtained with 3-MeV proton beams resulting in high resolution carbon maps, however, the count rate for nitrogen and oxygen was too low. The results demonstrate that on thin samples, 36-MeV C4+ will produce good quality PIXE spectra in less time; therefore, carbon ions may be advantageous depending on which element is being studied. However, these advantages may be outweighed by the inherent disadvantages including

  18. Beam instrumentation for the BNL Heavy Ion Transfer Line

    SciTech Connect

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

    1987-01-01

    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.

  19. Heavy-ion injection from tandems into an isochronous cyclotron

    SciTech Connect

    LeVine, M.J.; Chasman, C.

    1981-01-01

    A design has been realized for the injection of heavy ion beams generated by the BNL 3-stage tandem facility into a proposed isochronous cyclotron. The tandem beams are bunched into +- 1/sup 0/ R.F. phase (less than or equal to 0.5 nsec) in two stages. The beam is then injected into the cyclotron through a valley, past a hill, and into the next valley on to a stripper foil. Only a single steerer is required to make trajectory corrections for the different beams. Two achromats are used to regulate the tandem potential and to provide phase control. A final section of the injection optics provides matching of transverse phase space to the acceptance of the cyclotron. The calculations use realistic tandem emittances and magnetic fields for the cyclotron based on measurements with a model magnet.

  20. Stopping of relativistic heavy ions in various media

    NASA Technical Reports Server (NTRS)

    Waddington, C. J.; Fixsen, D. J.; Crawford, H. J.; Lindstrom, P. J.; Heckman, H. H.

    1986-01-01

    The residual ranges of (900 + or - 3)-MeV/amu gold nuclei accelerated at the Lawrence Berkeley Laboratory Bevalac have been measured in several different media. The energy of the beam of nuclei was measured directly using a new time-of-flight system. The ranges were measured by absorption in linear wedges of polyethylene, carbon, aluminum, copper, tin, and lead and in circular wedges of polystyrene, aluminum, and gold, and by total absorption in nuclear emulsion. The measured ranges were significantly different from those calculated from the best available theoretical estimates of the energy loss of highly charged nuclei. It is concluded that at present energy losses and residual ranges of relativistic heavy ions in an arbitrary medium cannot be predicted with better than an approximately 2 percent accuracy.

  1. Production of photons in relativistic heavy-ion collisions

    DOE PAGESBeta

    Jean -Francois Paquet; Denicol, Gabriel S.; Shen, Chun; Luzum, Matthew; Schenke, Bjorn; Jeon, Sangyong; Gale, Charles

    2016-04-18

    In this work it is shown that the use of a hydrodynamical model of heavy-ion collisions which incorporates recent developments, together with updated photon emission rates, greatly improves agreement with both ALICE and PHENIX measurements of direct photons, supporting the idea that thermal photons are the dominant source of direct photon momentum anisotropy. The event-by-event hydrodynamical model uses the impact parameter dependent Glasma model (IP-Glasma) initial states and includes, for the first time, both shear and bulk viscosities, along with second-order couplings between the two viscosities. Furthermore, the effect of both shear and bulk viscosities on the photon rates ismore » studied, and those transport coefficients are shown to have measurable consequences on the photon momentum anisotropy.« less

  2. Beam-beam observations in the Relativistic Heavy Ion Collider

    SciTech Connect

    Luo, Y.; Fischer, W.; White, S.

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  3. Formation of energetic heavy ion tracks in polyimide thin films

    NASA Astrophysics Data System (ADS)

    Deslandes, Alec; Murugaraj, Pandiyan; Mainwaring, David E.; Ionescu, Mihail; Cohen, David D.; Siegele, Rainer

    2013-11-01

    Polyimide thin films have been irradiated with a high energy beam of heavy ions to a fluence of approximately 4 × 1013 ions/cm2. Proton backscattering spectroscopy was used to measure the composition of the films, which showed that oxygen was the element that exhibited the most rapid loss from the film. The gases evolved from the film during polymer modification were monitored using a quadrupole mass spectrometer for residual gas analysis (RGA). The fluence dependence of RGA signals were indicative of multi-step processes of gas release, whereby the passage of an ion through a region of pristine film changes the local molecular structure to one that will more readily form volatile species when subsequent ions pass.

  4. Mutagenic effect of accelerated heavy ions on bacterial cells

    NASA Astrophysics Data System (ADS)

    Boreyko, A. V.; Krasavin, E. A.

    2011-11-01

    The heavy ion accelerators of the Joint Institute for Nuclear Research were used to study the regularities and mechanisms of formation of different types of mutations in prokaryote cells. The induction of direct (lac-, ton B-, col B) mutations for Esherichia coli cells and reverse his- → His+ mutations of Salmonella typhimurium, Bacillus subtilis cells under the action of radiation in a wide range of linear energy transfer (LET) was studied. The regularities of formation of gene and structural (tonB trp-) mutations for Esherichia coli bacteria under the action of accelerated heavy ions were studied. It was demonstrated that the rate of gene mutations as a function of the dose under the action of Γ rays and accelerated heavy ions is described by linear-quadratic functions. For structural mutations, linear "dose-effect" dependences are typical. The quadratic character of mutagenesis dose curves is determined by the "interaction" of two independent "hitting" events in the course of SOS repair of genetic structures. The conclusion made was that gene mutations under the action of accelerated heavy ions are induced by δ electron regions of charged particle tracks. The methods of SOS chromotest, SOS lux test, and λ prophage induction were used to study the regularities of SOS response of cells under the action of radiations in a wide LET range. The following proposition was substantiated: the molecular basis for formation of gene mutations are cluster single-strand DNA breaks, and that for structural mutations, double-strand DNA breaks. It was found out that the LET dependence of the relative biological efficiency of accelerated ions is described by curves with a local maximum. It was demonstrated that the biological efficiency of ionizing radiations with different physical characteristics on cells with different genotype, estimated by the lethal action, induction of gene and deletion mutations, precision excision of transposons, is determined by the specific

  5. Modelling early stages of relativistic heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Ruggieri, M.; Puglisi, A.; Oliva, L.; Plumari, S.; Scardina, F.; Greco, V.

    2016-05-01

    In this study we model early time dynamics of relativistic heavy ion collisions by an initial color-electric field which then decays to a plasma by the Schwinger mechanism. The dynamics of the many particles system produced by the decay is described by relativistic kinetic theory, taking into account the backreaction on the color field by solving self-consistently the kinetic and the field equations. Our main results concern isotropization and thermalization for a 1+1D expanding geometry. In case of small η/s (η/s ≲ 0.3) we find τisotropization ≈ 0.8 fm/c and τthermalization ≈ 1 fm/c in agreement with the common lore of hydrodynamics.

  6. Drift Compression and Final Focus Options for Heavy Ion Fusion

    SciTech Connect

    Hong Qin; Ronald C. Davidson; John J. Barnard; Edward P. Lee

    2005-02-14

    A drift compression and final focus lattice for heavy ion beams should focus the entire beam pulse onto the same focal spot on the target. We show that this requirement implies that the drift compression design needs to satisfy a self-similar symmetry condition. For un-neutralized beams, the Lie symmetry group analysis is applied to the warm-fluid model to systematically derive the self-similar drift compression solutions. For neutralized beams, the 1-D Vlasov equation is solved explicitly, and families of self-similar drift compression solutions are constructed. To compensate for the deviation from the self-similar symmetry condition due to the transverse emittance, four time-dependent magnets are introduced in the upstream of the drift compression such that the entire beam pulse can be focused onto the same focal spot.

  7. Theoretical overview: Light ion lessons, heavy ion hopes

    SciTech Connect

    Gavin, S.

    1992-01-01

    Experiments using light ion beams of atomic masses A [approximately] 30 have been underway since 1986 at the Brookhaven AGS and the CERN SPS at the respective energies [radical]s [approximately] 5 A GeV and 20 A GeV. The first truly heavy ion runs with a gold beam began this spring at the AGS. In this talk I will survey our progress towards an understanding of nuclear collision dynamics, focusing on those issues that are relevant to Au+Au at the AGS. In view of what we have already learned from the light ion data, I will argue that the prospects for producing matter at extreme density in these experiments are excellent.

  8. Theoretical overview: Light ion lessons, heavy ion hopes

    SciTech Connect

    Gavin, S.

    1992-12-31

    Experiments using light ion beams of atomic masses A {approximately} 30 have been underway since 1986 at the Brookhaven AGS and the CERN SPS at the respective energies {radical}s {approximately} 5 A GeV and 20 A GeV. The first truly heavy ion runs with a gold beam began this spring at the AGS. In this talk I will survey our progress towards an understanding of nuclear collision dynamics, focusing on those issues that are relevant to Au+Au at the AGS. In view of what we have already learned from the light ion data, I will argue that the prospects for producing matter at extreme density in these experiments are excellent.

  9. Mars heavy ion precipitating flux as measured by MAVEN

    NASA Astrophysics Data System (ADS)

    Leblanc, F.

    2015-12-01

    Mars' atmospheric escape induced by heavy planetary ions accelerated by the solar wind and reimpacting Mars' atmosphere has been suggested to occur. The sputtering of Mars' atmosphere has been even suggested to lead to a significant cumulated loss along Mars' history. Up to now, only a limited number of observations have been possible. ASPERA-3/Mars Express observed such precipitation only during extreme solar conditions events suggesting that sputtering might be not as intense as theoretically predicted. Based on MAVEN first six months of observations, we here show that precipitation of heavy ions also occur during quiet solar conditions and that the average precipitating flux during this period is significant and globally in good agreement with predictions. From these measured precipitating flux, we propose a first estimate of the atmospheric escape induced by sputtering. Up to 8.8×105 O/cm2/s was lost by Mars' atmosphere between November 2014 and April 2015.

  10. Multi-beam RFQ linac structure for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Hayashizaki, Noriyosu; Ishibashi, Takuya; Ito, Taku; Hattori, Toshiyuki

    2009-07-01

    Both the RF linear accelerator (linac) and the linear induction accelerator have been considered as injectors in a driver system for heavy ion fusion (HIF). In order to relax beam defocusing by space charge effect in the low-energy region, the accelerating beams that were merged and had their beam currents increased by the funnel tree system are injected into storage rings. A multi-beam linac that accelerates multiple beams in an accelerator cavity has the advantages of cost reduction and downsizing of the system. We modeled the multi-beam Interdigital-H type radio frequency quadruple (IH-RFQ) cavities with the different beam numbers and evaluated the electromagnetic characteristics by simulation. As a result, the reasonable ranges of their configuration were indicated for a practical use.

  11. Heavy ion collision evolution modeling with ECHO-QGP

    NASA Astrophysics Data System (ADS)

    Rolando, V.; Inghirami, G.; Beraudo, A.; Del Zanna, L.; Becattini, F.; Chandra, V.; De Pace, A.; Nardi, M.

    2014-11-01

    We present a numerical code modeling the evolution of the medium formed in relativistic heavy ion collisions, ECHO-QGP. The code solves relativistic hydrodynamics in (3 + 1)D, with dissipative terms included within the framework of Israel-Stewart theory; it can work both in Minkowskian and in Bjorken coordinates. Initial conditions are provided through an implementation of the Glauber model (both Optical and Monte Carlo), while freezeout and particle generation are based on the Cooper-Frye prescription. The code is validated against several test problems and shows remarkable stability and accuracy with the combination of a conservative (shock-capturing) approach and the high-order methods employed. In particular it beautifully agrees with the semi-analytic solution known as Gubser flow, both in the ideal and in the viscous Israel-Stewart case, up to very large times and without any ad hoc tuning of the algorithm.

  12. Relativistic viscous hydrodynamics for high energy heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Vredevoogd, Joshua Aaron

    It has been over a decade since the first experimental data from gold nuclei collisions at the Relativistic Heavy Ion Collider suggested hydrodynamic behavior. Early ideal hydrodynamical models ignored the large longitudinal gradients that imply viscosity playing an important role in the dynamics. In addition, at that time, much less was known about the equation of state predicted by lattice calculations of quantum chromodynamics and the effects of late (dilute) stage rescattering were handled within the hydrodynamic framework. This dissertation presents a three-dimensional viscous hydrodynamics code with a realistic equation of state coupled consistently to a hadron resonance gas calculation. This code is capable of making significant comparisons to experimental data as part of an effort to learn about the structure of experimental constraints on the microscopic interactions of dense, hot quark matter.

  13. Determining the structure of X (3872) in heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Abreu, L. M.; Khemchandani, K. P.; Martínez Torres, A.; Navarra, F. S.; Nielsen, M.

    2016-08-01

    We study the time evolution of the X (3872) abundance in the hot hadron gas produced in the late stage of heavy ion collisions. We use effective field Lagrangians to obtain the production and dissociation cross sections of X(3872). In this evaluation we include diagrams involving the anomalous couplings πD*D̅* and XD̅*D* and also the couplings of the X(3872) with charged D and D* mesons. With these new terms the X(3872) interaction cross sections are much larger than those found in previous works. Using these cross sections as input in rate equations, we conclude that during the expansion and cooling of the hadronic gas, the number of X(3872), originally produced at the end of the mixed QGP/hadron gas phase, is reduced by a factor of 4.

  14. Heavy ion induction linac drivers for inertial confinement fusion

    SciTech Connect

    Lee, E.P.; Hovingh, J.

    1988-10-01

    Intense beams of high energy heavy ions (e.g., 10 GeV Hg) are an attractive option for an ICF driver because of their favorable energy deposition characteristics. The accelerator systems to produce the beams at the required power level are a development from existing technologies of the induction linac, rf linac/storage ring, and synchrotron. The high repetition rate of the accelerator systems, and the high efficiency which can be realized at high current make this approach especially suitable for commercial ICF. The present report gives a summary of the main features of the induction linac driver system, which is the approach now pursued in the USA. The main subsystems, consisting of injector, multiple beam accelerator at low and high energy, transport and pulse compression lines, and final focus are described. Scale relations are given for the current limits and other features of these subsystems. 17 refs., 1 fig., 1 tab.

  15. Beam Compression in Heavy-Ion Induction Linacs

    SciTech Connect

    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.

    2009-01-01

    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.

  16. Observation of snake resonances at Relativistic Heavy Ion Collider

    SciTech Connect

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

    2010-09-27

    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.

  17. Potential measurements with heavy ion beam probe system on LHD

    SciTech Connect

    Shimizu, A.; Nishiura, M.; Kato, S.; Ido, T.; Toi, K.; Nakamura, S.

    2010-10-15

    The heavy ion beam probe system in the Large Helical Device (LHD) was improved as follows. At first, the additional new sweeper was installed into the diagnostic port to extend the observable region. By using this sweeper, the potential profile was measured in a wider minor radius range than in previous experiments, in the case of outward shifted magnetic configuration of LHD. Next, the real time control system was installed to control the probe beam orbit for measuring the potential in plasma with large plasma current. In this system, a digital signal processor was used to control the probe beam in real time. The system worked well in the fixed position observation mode. In the sweeping mode for profile measurement, this control system became unstable. The details of this system and the experimental results are reported in this article.

  18. Two models with rescattering for high energy heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Bøggild, H.; Hansen, Ole; Humanic, T. J.

    2006-12-01

    The effects of hadronic rescattering in high energy relativistic Au+Au collisions are studied using two very different models to describe the early stages of the collision. One model is based on a hadronic thermal picture and the other on a superposition of parton-parton collisions. Operationally, the output hadrons from each of these models are used as input to a hadronic rescattering calculation. The results of the rescattering calculations from each model are then compared with rapidity and transverse momentum distributions from the BNL Relativistic Heavy Ion Collider BRAHMS experiment. In spite of the different points of view of the two models of the initial stage, after rescattering, the observed differences between the models are mostly “washed out” and both models give observables that agree roughly with each other and with experimental data.

  19. Longitudinal fluid dynamics for ultrarelativistic heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Satarov, L. M.; Mishustin, I. N.; Merdeev, A. V.; Stöcker, H.

    2007-02-01

    We developed a 1+1 dimensional hydrodynamical model for central heavy-ion collisions at ultrarelativistic energies. Deviations from Bjorken's scaling are taken into account by implementing finite-size profiles for the initial energy density. The calculated rapidity distributions of pions, kaons, and antiprotons in central Au+Au collisions at sNN=200 GeV are compared with experimental data of the BRAHMS Collaboration. The sensitivity of the results to the choice of the equation of state, the parameters of the initial state, and the freeze-out conditions were investigated. Experimental constraints on the total energy of produced particles were used to reduce the number of model parameters. The best fits of experimental data were obtained for soft equations of state and Gaussian-like initial profiles of the energy density. It was found that initial energy densities required for fitting the experimental data decrease with the increasing critical temperature of the phase transition.

  20. The response of scintillators to heavy ions: 1, Plastics

    SciTech Connect

    McMahan, M.A.

    1987-10-01

    The response of various scintillator detectors to ions of A = 1-84 and energies E/A = 5 to 30 MeV have been measured, and are found to be linear above an energy of 100 MeV. Results are presented for a typical organic plastic scintillator including parametrizations of the data as a function of Z, A, and energy. These results can be used by anyone using scintillators as heavy ion detectors, with one calibration point giving a normalization that allows use of the whole set of curves. The response functions are compared to previous parametrizations at lower energies and discussed in terms of the theory of delta-ray formation in the scintillator.

  1. Heavy ion observations by MARIE in cruise phase and Marsorbit

    SciTech Connect

    Lee, Kerry T.; Cleghorn, Timothy F.; Cucinotta, Francis A.; Pinsky, Lawrence S.; Zeitlin, Cary

    2004-12-01

    The charged particle spectrum for nuclei from protons to neon, (charge Z = 10) was observed during the cruise phase and orbit around Mars by the MARIE charged particle spectrometer on the Odyssey spacecraft. The cruise data were taken between April 23, 2001 and mid-August 2001. The Mars orbit data were taken March 5, 2002 through May 2002 and are scheduled to continue until August 2004. Charge peaks are clearly separated for charges up to Z = 10. Especially prominent are the carbon and oxygen peaks, with boron and nitrogen also clearly visible. Although heavy ions are much less abundant than protons in the cosmic ray environment, it is important to determine their abundances because their ionization energy losses (proportional to Z2) are far more dangerous to humans and to instruments. Thus the higher charged nuclei make a significant contribution to dose and dose equivalent received in space. Results of the charged particle spectrum measurements will be reported.

  2. The high current transport experiment for heavy ion inertial fusion

    SciTech Connect

    Prost, L.R.; Baca, D.; Bieniosek, F.M.; Celata, C.M.; Faltens, A.; Henestroza, E.; Kwan, J.W.; Leitner, M.; Seidl, P.A.; Waldron, W.L.; Cohen, R.; Friedman, A.; Grote, D.; Lund, S.M.; Molvik, A.W.; Morse, E.

    2004-05-01

    The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program to explore heavy-ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density {approx} 0.2 {micro}C/m) over long pulse durations (4 {micro}s) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo and, electron and gas cloud effects. We present the results for a coasting 1 MeV K{sup +} ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius) for which the transverse phase-space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor ({approx}80%) is achieved with acceptable emittance growth and beam loss, even though the initial beam distribution is not ideal (but the emittance is low) nor in thermal equilibrium. We achieved good envelope control, and rematching may only be needed every ten lattice periods (at 80% fill factor) in a longer lattice of similar design. We also show that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics.

  3. SIMULATION OF INTENSE BEAMS FOR HEAVY ION FUSION

    SciTech Connect

    Friedman, A

    2004-06-10

    Computer simulations of intense ion beams play a key role in the Heavy Ion Fusion research program. Along with analytic theory, they are used to develop future experiments, guide ongoing experiments, and aid in the analysis and interpretation of experimental results. They also afford access to regimes not yet accessible in the experimental program. The U.S. Heavy Ion Fusion Virtual National Laboratory and its collaborators have developed state-of-the art computational tools, related both to codes used for stationary plasmas and to codes used for traditional accelerator applications, but necessarily differing from each in important respects. These tools model beams in varying levels of detail and at widely varying computational cost. They include moment models (envelope equations and fluid descriptions), particle-in-cell methods (electrostatic and electromagnetic), nonlinear-perturbative descriptions (''{delta}f''), and continuum Vlasov methods. Increasingly, it is becoming clear that it is necessary to simulate not just the beams themselves, but also the environment in which they exist, be it an intentionally-created plasma or an unwanted cloud of electrons and gas. In this paper, examples of the application of simulation tools to intense ion beam physics are presented, including support of present-day experiments, fundamental beam physics studies, and the development of future experiments. Throughout, new computational models are described and their utility explained. These include Mesh Refinement (and its dynamic variant, Adaptive Mesh Refinement); improved electron cloud and gas models, and an electron advance scheme that allows use of larger time steps; and moving-mesh and adaptive-mesh Vlasov methods.

  4. Charmonium production in relativistic heavy-ion collisions

    SciTech Connect

    Song, Taesoo; Han, Kyong Chol; Ko, Che Ming

    2011-09-15

    Using the two-component model that includes charmonium production from both initial nucleon-nucleon hard scattering and regeneration in the produced quark-gluon plasma, we study J/{psi} production in heavy-ion collisions at the Super Proton Synchrotron (SPS), Relativistic Heavy Ion Collider (RHIC), and Large Hadron Collider (LHC). For the expansion dynamics of produced hot dense matter, we use a schematic viscous hydrodynamic model with the specific shear viscosity in the quark-gluon plasma and the hadronic matter taken, respectively, to be two and ten times the lower bound of 1/4{pi} suggested by the anti-de Sitter/conformal field theory (AdS/CFT) correspondence. For the initial dissociation and the subsequent thermal decay of charmonia in the hot dense matter, we use the screened Cornell potential to describe the properties of charmonia and perturbative QCD to calculate their dissociation cross sections. Including regeneration of charmonia in the quark-gluon plasma via a kinetic equation with in-medium chamonium decay widths, we obtain a good description of measured J/{psi} nuclear modification factors in Pb + Pb collisions at {radical}(s{sub NN})=1.73 GeV at SPS and in Au + Au collisions at {radical}(s{sub NN})=200 GeV at RHIC. A reasonable description of the measured nuclear modification factor of high transverse momenta J/{psi} in Pb + Pb collisions at {radical}(s{sub NN})=2.76 TeV at LHC is also obtained.

  5. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    SciTech Connect

    Bieniosek, F.M.; Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2008-08-01

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  6. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    SciTech Connect

    Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2010-03-16

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  7. Imaging with a multiplane multiwire proportional chamber using heavy ion beams

    SciTech Connect

    Chu, W.T.; Alonso, J.R.; Tobias, C.A.

    1982-01-01

    A 16-plane multiwire proportional chamber has been developed to accurately map intensity profiles of heavy ion beams at the Bevalac. The imaging capability of the system has been tested for reconstruction of 3-dimensional representation of a canine thorax region using heavy ion beams.

  8. Imaging With A Multiplane Multiwire Proportional Chamber Using Heavy Ion Beams

    NASA Astrophysics Data System (ADS)

    Chu, W. T.; Alonso, J. R.; Tobias, C. A...

    1982-11-01

    A 16-plane multiwire proportional chamber has been developed to accurately map intensity pro files of heavy ion beams at the Bevalac. The imaging capability of the system has been tested for reconstruction of 3-dimensional representation of a canine thorax region using heavy ion beams.

  9. Imaging with a multiplane multiwire proportional chamber using heavy-ion beams

    NASA Astrophysics Data System (ADS)

    Chu, W. T.; Alonso, J. R.; Tobias, C. A.

    A 16 plane multiwire proportional chamber was developed to accurately map intensity profiles of heavy ion beams at the Bevalac. The imaging capability of the system was tested for reconstruction of 3 dimensional representation of a canine thorax region using heavy ion beams.

  10. Heavy ion beam studies and imaging with a multiplane multiwire proportional chamber

    NASA Astrophysics Data System (ADS)

    Chu, W. T.; Alonso, J. R.; Tobias, C.

    1981-03-01

    A 16-plane multiwire proportional chamber was used to accurately measure intensity profiles of heavy ion beams at the Bevalac. An imaging capability was developed for the system, allowing for reconstruction of three dimensional representation of radiological objects using heavy ion beams.

  11. Fourth workshop on Experiments and Detectors for a Relativistic Heavy Ion Collider

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    We present a description of an experiment which can be used to search for effects of strong electromagnetic fields on the production of e(sup +) e(sup -) pairs in the elastic scattering of two heavy ions at the Relativistic Heavy Ion Collider (RHIC). A very brief discussion of other possible studies of electromagnetic phenomena at RHIC is also presented.

  12. Non-Targeted Effects and the Dose Response for Heavy Ion Tumorigenesis

    NASA Technical Reports Server (NTRS)

    Chappell, Lori J.; Cucinotta, Francis A.

    2010-01-01

    There is no human epidemiology data available to estimate the heavy ion cancer risks experienced by astronauts in space. Studies of tumor induction in mice are a necessary step to estimate risks to astronauts. Previous experimental data can be better utilized to model dose response for heavy ion tumorigenesis and plan future low dose studies.

  13. Comparative study on sample stacking by moving reaction boundary formed with weak acid and weak or strong alkali in capillary electrophoresis: I. Theory.

    PubMed

    Cao, Chengxi; Zhang, Wei; Fan, Liuyin; Shao, Jing; Li, Si

    2011-05-15

    The condensation of low abundance zwitterion substance, such as protein and peptide, has great significance to the study on proteomics. This paper develops the theory on design of online stacking conditions of zwitterion by a moving reaction boundary (MRB) in capillary electrophoresis (CE). This concerns the choice of running and sample buffers, velocity design of MRB, and salt effect on the stacking. The theoretical results unveil that: (1) the velocity of MRB formed with weak acidic buffer and strong alkali should be set between zero and the velocity of zwitterion in the alkali phase, or no stacking occurs; (2) if a strong alkali is used to prepare the sample, a much long front plug of strong base must be injected before the alkaline sample plug for complete stacking, whereas no such front plug is needed if a weak alkali with enough high concentration and pH value is used to prepare the sample buffer; (3) the existence of salt in sample matrix has a weak effect on the stacking of zwitterion if sample is prepared with weak alkaline buffer, while has a dramatic effect on the same stacking if with a strong base buffer. In addition, the concentration of weak alkali used for preparation of sample should be set at the point, at which the velocity of MRB is as much as possible close to that of negative zwitterion. The developed theory and its computation are quantitatively proved by the experiments of zwitterion stacking by the MRB as shown in the previous and the accompanying papers. The proposed theoretic results hold obvious significances on-column stacking of low abundance zwitterions, such as amino acid, or peptides or proteins, in CE.

  14. Transport rates and momentum isotropization of gluon matter in ultrarelativistic heavy-ion collisions

    SciTech Connect

    Xu Zhe; Greiner, Carsten

    2007-08-15

    To describe momentum isotropization of gluon matter produced in ultrarelativistic heavy-ion collisions, the transport rate of gluon drift and the transport collision rates of elastic (gg{r_reversible}gg) as well as inelastic (gg{r_reversible}ggg) perturbative quantum chromodynamics- (pQCD) scattering processes are introduced and calculated within the kinetic parton cascade Boltzmann approach of multiparton scatterings (BAMPS), which simulates the space-time evolution of partons. We define isotropization as the development of an anisotropic system as it reaches isotropy. The inverse of the introduced total transport rate gives the correct time scale of the momentum isotropization. The contributions of the various scattering processes to the momentum isotropization can be separated into the transport collision rates. In contrast to the transport cross section, the transport collision rate has an indirect but correctly implemented relationship with the collision-angle distribution. Based on the calculated transport collision rates from BAMPS for central Au+Au collisions at Relativistic Heavy Ion Collider energies, we show that pQCD gg{r_reversible}ggg bremsstrahlung processes isotropize the momentum five times more efficiently than elastic scatterings. The large efficiency of the bremsstrahlung stems mainly from its large momentum deflection. Due to kinematics, 2{yields}N (N>2) production processes allow more particles to become isotropic in momentum space and thus kinetically equilibrate more quickly than their back reactions or elastic scatterings. We also show that the relaxation time in the relaxation time approximation, which is often used, is strongly momentum dependent and thus cannot serve as a global quantity that describes kinetic equilibration.

  15. Fragmentation of DNA components by hyperthermal heavy ion (Ar+ and Xe+) impact in the condensed phase

    NASA Astrophysics Data System (ADS)

    Sarabipour, Sarvenaz; Sarvenaz Sarabipour, Ms; Michaud, Marc; Deng, Zongwu; Huels, Michael A.

    The overriding environmental factor that presently limits human endeavors in space is exposure to heavy ion radiation. While knowledge of its damage to living tissue is essential for radiation protection and risk estimates for astronauts, very little data exists at the molecular level regarding the nascent DNA damage by the primary particle track, or by secondary species during subsequent reaction cascades. This persistent lack of a basic understanding of nascent damage induced by such low dose, high LET radiation, introduces unacceptable errors in radiation risk estimates (based mainly on extrapolation from high dose, low LET radiation), particularly for long term exposure. Mutagenic effects induced by heavy ion radiation to cells are largely due to DNA damage by secondary transient species, i.e. secondary ballistic ions, electrons and radicals generated along the ion tracks; the secondary ions have hyperthermal energies up to several 100 eV, which they will deposit within a few nm in the surrounding medium; thus their LET is very high, and yields lethal clustered DNA lesions. We present measurements of molecular damage induced in films of DNA components by ions with precisely such low energies (1-100 eV) and compare results to conventional electron impact measurements. Experiments are conducted in UHV using a mass selected low energy ion source, and a high-resolution quadrupole MS to monitor ion yields desorbing from molecular films. Among the major fragments, NH4 + is identified in the desorption mass spectra of irradiated films of Adenine, Guanine, Cytosine, indicating efficient deamination; in cells this results in pre-mutagenic lesions. Experiments with 5-amino-Uracil, and comparison to previous results on uracil and thymine show that deamination is a key step in the NH4 + fragment formation. For Adenine, we also observe formation of amine aducts in the films, viz. amination of Adenine, and global fragmentation in all ion impact mass spectra, attributed

  16. Dynamics of alkali ions-neutral molecules reactions: Radio frequency-guided beam experimental cross-sections and direct quasiclassical trajectory studies

    SciTech Connect

    Aguilar, J.; Andres, J. de; Lucas, J. M.; Alberti, M.; Huarte-Larranaga, F.; Bassi, D.; Aguilar, A.

    2012-11-27

    Different reactive processes taking place in collisions between alkali ions and neutral i-C{sub 3}H{sub 7}Cl molecules in the low (center of mass frame) energy range have been studied using an octopole radiofrequency guided-ion-beam apparatus developed in our laboratory. Cross-section energy dependences for all these reactions have been obtained in absolute units. Ab initio electronic structure calculations for those colliding systems evolving on the ground single potential surface have given relevant information on the main topological features of the surfaces. For some of the reactions a dynamic study by 'on the fly' trajectories has complemented the available experimental and electronic structure information.

  17. Heavy ion event generator HYDJET++ (HYDrodynamics plus JETs)

    NASA Astrophysics Data System (ADS)

    Lokhtin, I. P.; Malinina, L. V.; Petrushanko, S. V.; Snigirev, A. M.; Arsene, I.; Tywoniuk, K.

    2009-05-01

    HYDJET++ is a Monte Carlo event generator for simulation of relativistic heavy ion AA collisions considered as a superposition of the soft, hydro-type state and the hard state resulting from multi-parton fragmentation. This model is the development and continuation of HYDJET event generator (Lokhtin and Snigirev, EPJC 45 (2006) 211). The main program is written in the object-oriented C++ language under the ROOT environment. The hard part of HYDJET++ is identical to the hard part of Fortran-written HYDJET and it is included in the generator structure as a separate directory. The soft part of HYDJET++ event is the "thermal" hadronic state generated on the chemical and thermal freeze-out hypersurfaces obtained from the parameterization of relativistic hydrodynamics with preset freeze-out conditions. It includes the longitudinal, radial and elliptic flow effects and the decays of hadronic resonances. The corresponding fast Monte Carlo simulation procedure, C++ code FAST MC (Amelin et al., PRC 74 (2006) 064901; PRC 77 (2008) 014903) is adapted to HYDJET++. It is designed for studying the multi-particle production in a wide energy range of heavy ion experimental facilities: from FAIR and NICA to RHIC and LHC. Program summaryProgram title: HYDJET++, version 2 Catalogue identifier: AECR_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECR_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 100 387 No. of bytes in distributed program, including test data, etc.: 797 019 Distribution format: tar.gz Programming language: C++ (however there is a Fortran-written part which is included in the generator structure as a separate directory) Computer: Hardware independent (both C++ and Fortran compilers and ROOT environment [1] ( http://root.cern.ch/) should be installed

  18. Alkali- or acid-induced changes in structure, moisture absorption ability and deacetylating reaction of β-chitin extracted from jumbo squid (Dosidicus gigas) pens.

    PubMed

    Jung, Jooyeoun; Zhao, Yanyun

    2014-01-01

    Alkali- or acid-induced structural modifications in β-chitin from squid (Dosidicus gigas, d'Orbigny, 1835) pens and their moisture absorption ability (MAA) and deacetylating reaction were investigated and compared with α-chitin from shrimp shells. β-Chitin was converted into the α-form after 3h in 40% NaOH or 1-3 h in 40% HCl solution, and α-chitin obtained from NaOH treatment had higher MAA than had native α-chitin, due to polymorphic destructions. In contrast, induced α-chitin from acid treatment of β-chitin had few polymorphic modifications, showing no significant change (P>0.05) in MAA. β-Chitin was more susceptible to alkali deacetylation than was α-chitin, and required a lower concentration of NaOH and shorter reaction time. These results demonstrate that alkali- or acid-treated β-chitin retained high susceptibility toward solvents, which in turn resulted in good biological activity of β-chitosan for use as a natural antioxidant and antimicrobial substance or application as edible coatings and films for various food applications.

  19. Isospin Effects in Heavy-Ion Collisions: Some Results From CHIMERA Experiments At LNS And Perspectives With Radioactive Beams

    SciTech Connect

    Cardella, G.; De Filippo, E.; Pagano, A.; Papa, M.; Pirrone, S.; Verde, G.; Amorini, F.; Cavallaro, S.; Lombardo, I.; Porto, F.; Rizzo, F.; Russotto, P.; Anzalone, A.; Maiolino, C.; Arena, N.; Geraci, E.; Grassi, L.; Lo Nigro, S.; Politi, G.; Auditore, L.

    2009-05-04

    CHIMERA is a 4{pi} multidetector for charged particles available at Laboratori Nazionali del Sud (INFN-LNS). A new method to measure the time scale of the emission of nuclear fragments is described, together with some applications in the field of the isospin dynamics of heavy-ion collisions. Competition between fusion-like and binary reactions near the energy threshold for nuclear multifragmentation is discussed. Opportunities are pointed out to use the detector at low and intermediate energies using the kinematical-coincidence method.

  20. Antiradiation Vaccine: Technology Development- Radiation Tolerance,Prophylaxis, Prevention And Treatment Of Clinical Presentation After Heavy Ion Irradiation.

    NASA Astrophysics Data System (ADS)

    Popov, Dmitri; Maliev, Slava; Jones, Jeffrey

    Introduction: Research in the field of biological effects of heavy charged particles is necessary for both heavy-ion therapy (hadrontherapy) and protection from the exposure to galactic cosmic radiation in long-term manned space missions.[Durante M. 2004] In future crew of long-term manned missions could operate in exremely high hadronic radiation areas of space and will not survive without effective radiation protection. An Antiradiation Vaccine (AV) must be an important part of a countermeasures regimen for efficient radiation protection purposes of austronauts-cosmonauts-taukonauts: immune-prophylaxis and immune-therapy of acute radiation toxic syndromes developed after heavy ion irradiation. New technology developed (AV) for the purposes of radiological protection and improvement of radiation tolerance and it is quite important to create protective immune active status which prevent toxic reactions inside a human body irradiated by high energy hadrons.[Maliev V. et al. 2006, Popov D. et al.2008]. High energy hadrons produce a variety of secondary particles which play an important role in the energy deposition process, and characterise their radiation qualities [Sato T. et al. 2003] Antiradiation Vaccine with specific immune-prophylaxis by an anti-radiation vaccine should be an important part of medical management for long term space missions. Methods and experiments: 1. Antiradiation vaccine preparation standard, mixture of toxoid form of Radiation Toxins [SRD-group] which include Cerebrovascular RT Neurotoxin, Cardiovascular RT Neurotoxin, Gastrointestinal RT Neurotoxin, Hematopoietic RT Hematotoxin. Radiation Toxins of Radiation Determinant Group isolated from the central lymph of gamma-irradiated animals with Cerebrovascular, Cardiovascular, Gastro-intestinal, Hematopoietic forms of ARS. Devices for radiation are "Panorama", "Puma". 2. Heavy ion exposure was accomplished at Department of Research Institute of Nuclear Physics, Dubna, Russia. The heavy ions