WorldWideScience

Sample records for heavy-ion reaction products

  1. Direct photon production in heavy-ion reactions at SPS and RHIC

    Indian Academy of Sciences (India)

    A review on experimental results for direct photon production in heavy ion reactions is given. A brief survey of early direct photon limits from SPS experiments is presented. The first measurement of direct photons in heavy ion reactions from the WA98 collaboration is discussed and compared to theoretical calculations.

  2. Direct photon production in heavy-ion reactions at SPS and RHIC

    Indian Academy of Sciences (India)

    The first measurement of direct photons in heavy ion reactions from the WA98 collaboration is discussed and compared to ... Experimentally, high energy direct photon measurement has always been consid- ered a challenge. This is ... charged and neutral pion spectra from different heavy-ion experiments. They estimate a.

  3. Dynamical deformation in heavy ion reactions and the characteristics of quasifission products

    Science.gov (United States)

    Guo, S. Q.; Gao, Y.; Li, J. Q.; Zhang, H. F.

    2017-10-01

    The investigation of the characteristics of low-energy heavy ion reactions covering both fusion and quasifission is carried out within the dinuclear system (DNS) concept, which is developed to include the deformation variables of fragments in addition to the mass numbers of the fragments, so that the energy dissipation, nucleon exchange, and deformation evolutions of the colliding nuclei as well as their correlations are treated simultaneously, and the potential energy surface of the system is thus reaction-time dependent. The direct consequence of introducing the deformation of fragments as dynamical variables is that one must treat the orientation between the two deformed nuclei. This is solved by introducing a barrier function. It is found that the model can reproduce data about the mass, as well as the total kinetic energy and its dispersion, of the reaction products very well, revealing that the DNS model has a reasonable theoretical foundation and thus can reliably describe the reaction mechanism.

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

    Energy Technology Data Exchange (ETDEWEB)

    Moody, Kenton James [Univ. of California, Berkeley, CA (United States)

    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 248Cm with 18O, 86Kr and 136Xe projectiles at several energies near and below the Coulomb barrier were determined. The results are compared with yields from 48Ca and 238U bombardments of 248Cm. 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 136Xe and 238U the new species 248Am, 249Am and 247Pu should be produced with large cross sections from a 248Cm target. A preliminary, unsuccessful attempt to isolate 247Pu 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 251Bk decay, necessary for calculating the 251Bk cross section, are also determined.

  5. IVO, a device for In situ Volatilization and On-line detection of products from heavy ion reactions

    CERN Document Server

    Duellmann, C E; Eichler, R; Gäggeler, H W; Jost, D T; Piguet, D; Türler, A

    2002-01-01

    A new gaschromatographic separation system to rapidly isolate heavy ion reaction products in the form of highly volatile species is described. Reaction products recoiling from the target are stopped in a gas volume and converted in situ to volatile species, which are swept by the carrier gas to a chromatography column. Species that are volatile under the given conditions pass through the column. In a cluster chamber, which is directly attached to the exit of the column, the isolated volatile species are chemically adsorbed to the surface of aerosol particles and transported to an on-line detection system. The whole set-up was tested using short-lived osmium (Os) and mercury (Hg) nuclides produced in heavy ion reactions to model future chemical studies with hassium (Hs, Z=108) and element 112. By varying the temperature of the isothermal section of the chromatography column between room temperature and -80 deg. C, yield measurements of given species can be conducted, yielding information about the volatility o...

  6. Transfer products from the reactions of heavy ions with heavy nuclei. [394 to 1156 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K.E. III

    1979-11-01

    Production of nuclides heavier than the target from /sup 86/Kr- and /sup 136/Xe-induced reactions with /sup 181/Ta and /sup 238/U was investigated. Attempts were made to produce new neutron-excess Np and Pu isotopes by the deep inelastic mechanism. No evidence was found for /sup 242/Np or /sup 247/Pu. Estimates were made for the production of /sup 242/Np, /sup 247/Pu, and /sup 248/Am from heavy-ion reactions with uranium targets. Comparisons of reactions of /sup 86/Kr and /sup 136/Xe ions with thick /sup 181/Ta targets and /sup 86/Kr, /sup 136/Xe and /sup 238/U ions with thick /sup 238/U targets indicate that the most probable products are not dependent on the projectile. The most probable products can be predicted by the equation Z - Z/sub target/ = 0.43 (A - A/sub target/) + 1.0. The major effect of the projectile is the magnitude of the production cross section of the heavy products. Based on these results, estimates are made of the most probable mass of element 114 produced from heavy-ion reactions with /sup 248/Cm and /sup 254/Es targets. These estimates give the mass number of element 114 as approx. 287 if produced in heavy-ion reactions with these very heavy targets. Excitation functions of gold and bismuth isotopes arising from /sup 86/Kr- and /sup 136/Xe-induced reactions with thin /sup 181/Ta targets were measured. These results indicate that the shape and location (in Z and A above the target) of the isotopic distributions are not strongly dependent on the projectile incident energy. Also, the nuclidic cross sections are found to increase with an increase in projectile energy to a maximum at approximately 1.4 to 1.5 times the Coulomb barrier. Above this maximum, the nuclidic cross sections are found to decrease with an increase in projectile energy. This decrease in cross section is believed to be due to fission of the heavy products caused by high excitation energy and angular momentum. 111 references, 39 figures, 34 tables.

  7. Quarkonium production in heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Arnaldi Roberta

    2014-03-01

    Full Text Available The production of quarkonium states plays a crucial role among the probes to investigate the formation of the plasma of quarks and gluons (QGP in heavy-ion collisions. A review of the charmonium and bottomonium production, mainly focussing on the latest results from the LHC experiments, is presented.

  8. Reaction mechanisms in heavy ion fusion

    Directory of Open Access Journals (Sweden)

    Lubian J.

    2011-10-01

    Full Text Available We discuss the reaction mechanisms involved in heavy ion fusion. We begin with collisions of tightly bound systems, considering three energy regimes: energies above the Coulomb barrier, energies just below the barrier and deep sub-barrier energies. We show that channel coupling effects may influence the fusion process at above-barrier energies, increasing or reducing the cross section predicted by single barrier penetration model. Below the Coulomb barrier, it enhances the cross section, and this effect increases with the system’s size. It is argued that this behavior can be traced back to the increasing importance of Coulomb coupling with the charge of the collision partners. The sharp drop of the fusion cross section observed at deep sub-barrier energies is addressed and the theoretical approaches to this phenomenon are discussed. We then consider the reaction mechanisms involved in fusion reactions of weakly bound systems, paying particular attention to the calculations of complete and incomplete fusion available in the literature.

  9. Radiochemical study of the reactions of heavy ions with gold

    Energy Technology Data Exchange (ETDEWEB)

    Binder, I.

    1977-07-01

    Thick gold foils have been bombarded with heavy-ion projectiles at energies above the Coulomb barrier. The radioactive products were identified and their yields measured using gamma-ray spectrometry and an extensive series of computer programs developed for the data analysis. The total mass-yield distribution was extracted from the data using charge-dispersion curves inferred from the experimental results. One observes a change in the mass-yield distributions corresponding to primarily fusion-fission tractions occurring with the lighter projectiles Ne-20 and Ar-40 and deep-inelastic transfer reactions predominating with heavier Kr-84, Kr-86, and Xe-136 projectiles. For the deep-inelastic transfer reaction, more mass transfer is seen to occur for a higher incident projectile energy, and the Gaussian distribution of products shows exponential tailing. The preferred direction for mass transfer is from gold to the projectile nucleus. Sequential fission is a likely fate for nucludes beyond the lead shell closure. The ''gold finger'' is explained as a combination of mass transfer, nucleon evaporation and sequential fission. The yields of gold nuclides indicate a superposition of two reaction mechanisms, quasi-elastic and deep-inelastic. The angular momentum involved with each mechanism determines which of two isomeric states is the end product of the nuclear reaction. Suggestions are offered regarding the possibility of synthesizing super-heavy elements by use of heavy-ion nuclear reactions.

  10. Production of N{congruent}Z Nuclei with A{approx}100 via Complete Heavy-Ion Fusion Reactions Followed by Cluster Emission

    Energy Technology Data Exchange (ETDEWEB)

    M. La Commara; J. Gomez del Campo; A. D' Onofrio; A. Gadea; M. Glogowski; P. Jarillo-Herrero; N. Belcari; R. Borcea; G. de Angelis; C. Fahlander; M. Gorska; H. Grawe; M. Hellstroem; R. Kirchner; M. Rejmund; V. Roca; E. Roeckl; M. Romano; K. Rykaczewski; K. Schmidt; F. Terrasi

    1999-12-31

    The production of isotopes near {sup 100}Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete fusion reactions. We measured {beta}-delayed protons and {gamma}-rays, deduced the mass-separated beam intensities for {sup 99}Cd, {sup 100}In, {sup 101}Sn and {sup 102}In, and determined the corresponding production cross-sections {sigma} for {sup 58}Ni+{sup 58}Ni reactions followed by emission of nuclear clusters, and for {sup 58}Ni+{sup 50}Cr reactions accompanied by emission of protons, neutrons and {alpha} particles. The results indicate that the {sigma} values for reactions followed by emission of clusters are comparable with those for reactions proceeding through light particle emission. Due to recoil-loss effects in on-line mass separation, the former mechanism is less suitable than the latter one for producing such neutron-deficient nuclei in this kind of experiments.

  11. The Lund–York–Cologne Calorimeter (LYCCA): Concept, design and prototype developments for a FAIR-NUSTAR detector system to discriminate relativistic heavy-ion reaction products

    Energy Technology Data Exchange (ETDEWEB)

    Golubev, P., E-mail: Pavel.Golubev@nuclear.lu.se [Department of Physics, Lund University, SE-22100 Lund (Sweden); Wendt, A. [Institut für Kernphysik, Universität zu Köln, D-50937 Köln (Germany); Scruton, L. [Department of Physics, University of York, York YO10 5DD (United Kingdom); Taprogge, J. [Institut für Kernphysik, Universität zu Köln, D-50937 Köln (Germany); Rudolph, D. [Department of Physics, Lund University, SE-22100 Lund (Sweden); Reiter, P. [Institut für Kernphysik, Universität zu Köln, D-50937 Köln (Germany); Bentley, M.A. [Department of Physics, University of York, York YO10 5DD (United Kingdom); Avdeichikov, V. [Department of Physics, Lund University, SE-22100 Lund (Sweden); Boutachkov, P. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Fox, S.P. [Department of Physics, University of York, York YO10 5DD (United Kingdom); Gerl, J. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Görgen, Ch. [Institut für Kernphysik, Universität zu Köln, D-50937 Köln (Germany); and others

    2013-09-21

    The concept, design and prototype developments for the Lund–York–Cologne CAlorimeter (LYCCA) is presented. LYCCA is a modular device for the NUclear STructure, Astrophysics and Reactions (NUSTAR) science pillar of the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. LYCCA is designed to discriminate heavy ions produced in nuclear reactions induced by relativistic radioactive ion beams. Measurements of energy loss, total energy, and time-of-flight allow the derivation of proton number, Z, and mass number, A, of the reaction products. LYCCA-inherent tracking of the flight paths of the reaction products enables coincident HIgh-resolution in-beam γ-ray SPECtroscopy (HISPEC) of atomic nuclei far from the line of β-stability.

  12. The Lund-York-Cologne Calorimeter (LYCCA): Concept, design and prototype developments for a FAIR-NUSTAR detector system to discriminate relativistic heavy-ion reaction products

    Science.gov (United States)

    Golubev, P.; Wendt, A.; Scruton, L.; Taprogge, J.; Rudolph, D.; Reiter, P.; Bentley, M. A.; Avdeichikov, V.; Boutachkov, P.; Fox, S. P.; Gerl, J.; Görgen, Ch.; Hoischen, R.; Kurz, N.; Nara Singh, B. S.; Pascovici, G.; Pietri, S.; Schaffner, H.; Taylor, M. J.; Thiel, S.; Wollersheim, H. J.

    2013-09-01

    The concept, design and prototype developments for the Lund-York-Cologne CAlorimeter (LYCCA) is presented. LYCCA is a modular device for the NUclear STructure, Astrophysics and Reactions (NUSTAR) science pillar of the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. LYCCA is designed to discriminate heavy ions produced in nuclear reactions induced by relativistic radioactive ion beams. Measurements of energy loss, total energy, and time-of-flight allow the derivation of proton number, Z, and mass number, A, of the reaction products. LYCCA-inherent tracking of the flight paths of the reaction products enables coincident HIgh-resolution in-beam γ-ray SPECtroscopy (HISPEC) of atomic nuclei far from the line of β-stability.

  13. Current experimental situation in heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D.K.

    1978-06-01

    A detailed survey of the present experimental situation in heavy-ion physics is presented. The discussion begins by considering the simple excitation of discrete states in elastic scattering, transfer, and compound-nucleus reactions; it then turns to more drastic perturbations of the nucleus high in the continuum through fusion, fission, and deeply inelastic scattering, and concludes with the (possibly) limiting asymptotic phenomena of relativistic heavy-ion collisions. 138 figures, 5 tables, 451 references. (RWR)

  14. Subthreshold photons in heavy-ion reactions at intermediate energies

    NARCIS (Netherlands)

    Martinez, G

    1998-01-01

    In the present talk, I discuss about the properties of the energetic photons produced in heavy-ion reactions. I show that they are sensitive to the maximum density reached in the first stage of the nuclear reaction. Then, the existence of a thermal contribution to the photon differential

  15. Classical simulations of heavy-ion fusion reactions and weakly ...

    Indian Academy of Sciences (India)

    This model is extended to simulate heavy-ion reactions such as 6Li + 209Bi involving the weakly-bound projectile considered as a weakly-bound cluster of deuteron and 4He nuclei, thus, simulating a 3-body system in 3S-CMD model. All the essential features of breakup reactions, such as complete fusion, incomplete fusion ...

  16. Heavy ion transfer reactions: Status and perspectives

    Indian Academy of Sciences (India)

    2015-11-27

    array (CLARA), extensive investigations of nuclear structure and reaction dynamics have been carried out. In the present paper aspects of these studies will be presented, focussing more closely on the reaction mechanism, ...

  17. Improved ion guide for heavy-ion fusion-evaporation reactions

    NARCIS (Netherlands)

    Dendooven, P; Beraud, R; Chabanat, E; Emsallem, A; Honkanen, A; Huhta, M; Jokinen, A; Lhersonneau, G; Oinonen, M; Penttila, H; Perajarvi, K; Wang, J.C.; Aysto, J

    1998-01-01

    The ion guide for heavy-ion-induced reactions developed originally for the SARA facility in Grenoble has been implemented at the Jyvaskyla IGISOL facility. For the Cd-116(Ar-40, 6n)Dy-150 reaction an efficiency of 0.5% relative to the number of reaction products entering the stopping chamber was

  18. HARD PHOTON INTENSITY INTERFEROMETRY IN HEAVY-ION REACTIONS

    NARCIS (Netherlands)

    OSTENDORF, R; SCHUTZ, Y; MERROUCH, R; LEFEVRE, F; DELAGRANGE, H; MITTIG, W; BERG, FD; KUHN, W; METAG, [No Value; NOVOTNY, R; PFEIFFER, M; BOONSTRA, AL; LOHNER, H; VENEMA, LB; WILSCHUT, HW; HENNING, W; HOLZMANN, R; MAYER, RS; SIMON, R; ARDOUIN, D; DABROWSKI, H; ERAZMUS, B; LEBRUN, C; SEZAC, L; LAUTRIDOU, P; QUEBERT, J; BALLESTER, F; CASAL, E; DIAZ, J; FERRERO, JL; MARQUES, M; MARTINEZ, G; NIFENECKER, H; FORNAL, B; FREINDL, L; SUJKOWSKI, Z; MATULEWICZ, T

    1992-01-01

    The present experimental knowledge on hard photon production in heavy ion collisions is summarized. An attempt to measure for the first time the intensity interference using photons in the MEV range is described. The effect is interpreted in terms of spatial and temporal extent of the photon's

  19. Study of the Particle Production in $^{12}$C Induced Heavy Ion Reactions at 86 MeV/N

    CERN Multimedia

    2002-01-01

    The aim of this experiment is to study various characteristics of light and heavy particle production in |1|2C induced reactions if possible over the whole unexplored energy region 50-86~MeV/N. In particular we want to investigate how the correlations in the multiparticle events can help us to distinguish bet existing models. \\\\ \\\\ Two-proton large-angle correlations and correlations between two heavier (Z~=~1 or 2) particles are studied with scintillator +~NaI and range telescopes, complemented with a 24 telescope scintillator wall for projectile fragments. Thereby we receive information about the reaction plane and the impact parameter in coincidence with the two-particle correlation spectra. Small @Dp correlations can also be studied. The inclusive @p|+ and @p|- production has been followed far below the nucleon-nucleon threshold. Pions are thereby identified from @DE-E correlations and the @p|+ decay in plastic range telescopes. These results are now followed up by @p-projectile fragment and @p-p correlat...

  20. Experimental review of quarkonium production in heavy-ion collisions

    Science.gov (United States)

    Zha, Wangmei; Tang, Zebo

    2017-08-01

    Quarkonium provides a sensitive probe to the properties of the quark-gluon plasma (QGP). Its production yield in heavy-ion collisions is modified by the color-screening effect, heavy quark (re)combination effect and cold nuclear matter effects. These effect have different sensitivity to various properties of the medium. Using quarkonium to experimentally study the properties of the QGP requires comprehensive measurements in heavy-ion collisions. In this article, we review the recent experimental measurements of different quarkonium states in heavy-ion collisions at the RHIC and the LHC.

  1. Heavy-ion reactions at the GSI Darmstadt

    Energy Technology Data Exchange (ETDEWEB)

    Metag, V. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)]|[Giessen Univ. (Germany). 2. Physikalisches Inst.

    1998-12-01

    In nucleus-nucleus collisions at bombarding energies on the order of 1 AGeV nuclear matter can be compressed to similar densities as encountered in stellar processes, i.e. to 2-3 times normal density. Experimental data providing information on the space-time evolution of these collisions are presented: the properties of hadrons in the hot and compressed nuclear medium in the high-density phase, collective flow phenomena during the expansion phase, and the hadrochemical composition of the collision system in the final stage of the reaction at freeze-out are discussed. Future directions in the heavy-ion reaction program are indicated. (orig.)

  2. Crystal-blocking measurements in heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Gomez del Campo, J.; Fearick, R.W.; Biggerstaff, J.A.; Moak, C.D.; Miller, P.D.; Neskovic, N.; Shapira, D.; Sellschop, J.P.F.

    1983-01-01

    The crystal blocking technique has been employed in the study of /sup 16/O + /sup nat/Ge and /sup 16/O + /sup 12/C (diamond) reactions. Measurements of the projectile-like fragments in the /sup 16/O + Ge reaction gave reaction times as fast as the elastic scattering; however, substantial time effects are seen for the evaporation residues (ER) of the fusion of /sup 16/O + /sup 12/C. Deexcitation times of the ER of 120-MeV /sup 16/O + /sup 12/C, emerging along the (110) axis of a 12-..mu..m diamond crystal were extracted and they ranged from 4 x 10/sup -18/ sec for Mg to 4 x 10/sup -18/ sec for N. These values are consistent with statistical model predictions and demonstrate the sequential decay nature of the deexcitation process in heavy-ion fusion reactions.

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

    Science.gov (United States)

    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.

  4. Hydrodynamics and freeze out problems in energetic heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yun

    2010-09-15

    The work is describing the development from QGP to the final stage (Freeze out) in energetic heavy ion reactions, which is particularly important because this model, based on matter properties we are interested in, describes the observables and can be compared to the experimental results. My doctoral work is mainly on theoretical models, which generated a full list of experimentally observable particles, and then evaluated the produced set of particles, comparable to those in experiments. Thus we produced the same collective observables that are measured in experiments. I concentrated on calculating the flow variables and presented a solution of the continuity equations, which provided a generalized description on matching heavy ion collision stages in a theoretical and simplified way. We also connected our hydrodynamic model with the PACIAE model, aiming for examining the flow properties. This work included the generation of parton distributions for the PACIAE model. The development of hybrid models is now in rapid progress internationally as these models are the most adequate to describe the experimental data in all details. The simple analytic treatment of the hydro and molecular dynamical stages of the model presents an important advantage and increased accuracy in the model construction. (Author)

  5. Light charged particle emission in heavy-ion reactions – What have ...

    Indian Academy of Sciences (India)

    Light charged particle emission in heavy-ion reactions –. What have we learnt? S KAILAS. Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. Abstract. Light charged particles emitted in heavy-ion induced reactions, their spectra and angu- lar distributions measured over a range of energies, ...

  6. Real causes of apparent abnormal results in heavy ion reactions

    Directory of Open Access Journals (Sweden)

    Mandaglio G.

    2015-01-01

    Full Text Available We study the effect of the static characteristics of nuclei and dynamics of the nucleus-nucleus interaction in the capture stage of reaction, in the competition between quasifission and complete fusion processes, as well as the angular momentum dependence of the competition between fission and evaporation processes along the de-excitation cascade of the compound nucleus. The results calculated for the mass-asymmetric and less mass-asymmetric reactions in the entrance channel are analyzed in order to investigate the role of the dynamical effects on the yields of the evaporation residue nuclei. We also discuss about uncertainties at the extraction of such relevant physical quantities as Γn/Γtot ratio or also excitation functions from the experimental results due to the not always realistic assumptions in the treatment and analysis of the detected events. This procedure can lead to large ambiguity when the complete fusion process is strongly hindered or when the fast fission contribution is large. We emphasize that a refined multiparameter model of the reaction dynamics as well as a more detailed and checked data analysis are strongly needed in heavy-ion collisions.

  7. Light nuclei production in heavy ion collisions

    CERN Document Server

    Khan, K H; Wazir, Z; Khan, E U; Haseeb, Mahnaz Q; Ajaz, M

    2009-01-01

    Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.

  8. Performance of the CERN Heavy Ion production complex

    CERN Document Server

    Manglunki, D; Bartosik, H; Bellodi, G; Blas, A; Bohl, T; Carli, C; Carlier, E; Cettour Cave, S; Cornelis, K; Damerau, H; Efthymiopoulos, I; Findlay, A; Gilardoni, S; Hancock, S; Jowett, JM; Kuchler, D; Maury, S; O'Neil, M; Papaphilippou, Y; Pasinelli, S; Scrivens, R; Tranquille, G; Vandorpe, B; Wehrle, U; Wenninger, J

    2012-01-01

    The second LHC ion run took place at 1.38 A TeV/c per beam in autumn 2011; more than 100 inverse microbarns were accumulated by each of the experiments. In addition, the LHC injector chain delivered primary Pb and secondary Be ion beams to fixed target experiments in the SPS North Area. This paper presents the current performance of the heavy ion production complex, and prospects to further improve it in the near future.

  9. Interplay of short-range correlations and nuclear symmetry energy in hard-photon production from heavy-ion reactions at Fermi energies

    Science.gov (United States)

    Yong, Gao-Chan; Li, Bao-An

    2017-12-01

    Within an isospin- and momentum-dependent transport model for nuclear reactions at intermediate energies, we investigate the interplay of the nucleon-nucleon short-range correlations (SRCs) and nuclear symmetry energy Esym(ρ ) on hard-photon spectra in collisions of several Ca isotopes on 112Sn and 124Sn targets at a beam energy of 45 MeV/nucleon. It is found that over the whole spectra of hard photons studied, effects of the SRCs overwhelm those owing to the Esym(ρ ) . The energetic photons come mostly from the high-momentum tails (HMTs) of single-nucleon momentum distributions in the target and projectile. Within the neutron-proton dominance model of SRCs based on the consideration that the tensor force acts mostly in the isosinglet and spin-triplet nucleon-nucleon interaction channel, there are equal numbers of neutrons and protons, thus a zero isospin asymmetry in the HMTs. Therefore, experimental measurements of the energetic photons from heavy-ion collisions at Fermi energies have the great potential to help us better understand the nature of SRCs without any appreciable influence by the uncertain Esym(ρ ) . These measurements will be complementary to but also have some advantages over the ongoing and planned experiments using hadronic messengers from reactions induced by high-energy electrons or protons. Because the underlying physics of SRCs and Esym(ρ ) are closely correlated, a better understanding of the SRCs will, in turn, help constrain the nuclear symmetry energy more precisely in a broad density range.

  10. A large area position-sensitive ionization chamber for heavy-ion-induced reaction studies

    CERN Document Server

    Pant, L M; Dinesh, B V; Thomas, R G; Saxena, A; Sawant, Y S; Choudhury, R K

    2002-01-01

    A large area position-sensitive ionization chamber with a wide dynamic range has been developed to measure the mass, charge and energy of the heavy ions and the fission fragments produced in heavy-ion-induced reactions. The split anode geometry of the detector makes it suitable for both particle identification and energy measurements for heavy ions and fission fragments. The detector has been tested with alpha particles from sup 2 sup 4 sup 1 Am- sup 2 sup 3 sup 9 Pu source, fission fragments from sup 2 sup 5 sup 2 Cf and the heavy-ion beams from the 14UD Mumbai Pelletron accelerator facility. Using this detector, measurements on mass and total kinetic energy distributions in heavy-ion-induced fusion-fission reactions have been carried out for a wide range of excitation energies. Results on deep inelastic collisions and mass-energy correlations on different systems using this detector setup are discussed.

  11. Studies of Heavy-Ion Reactions and Transuranic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, W. Udo [Univ. of Rochester, NY (United States). Dept. of Chemistry. Dept. of Physics

    2016-07-28

    Studies of heavy-ion reactions and transuranic nuclei performed by the University of Rochester Nuclear Science Research Group have been successful in furthering experimental systematics and theoretical understanding of the behavior of nuclear systems excited to their limits of stability. The theoretical results explain specifically the “boiling” and “vaporization” of atomic nuclei, but are more generally applicable to isolated, quantal many-particle systems which, under thermal or mechanical stresses, all disintegrate by evaporation, via surface cluster emission, or via fission-like processes. Accompanying experimental investigations by the group have demonstrated several new types of dynamical instability of nuclei: In central, “head-on” collisions, target nuclei exhibit limited ability to stop energetic projectile nuclei and to dissipate the imparted linear momentum. Substantial matter overlap (“neck”) between projectile and target nuclei, which is observed at elevated collision energies, can be stretched considerably and break at several places simultaneously. These results provide new testing grounds for microscopic theory of the cohesion of nuclear matter. This property has remained elusive, even though the elementary nucleon-nucleon forces are well known since some time. Technical R&D has resulted in a detailed characterization of a novel plastic material, which can now be used in the design of sensitive diagnostic systems for various types of radio-activity. Innovative application of powerful laser systems has produced intense, controllable sources of exotic particle radioactivity for nuclear investigations. Several students have received their Ph.D. degree in experimental nuclear science for their work on basic nuclear research or R&D projects.

  12. Recent studies in heavy ion induced fission reactions

    Indian Academy of Sciences (India)

    channel spins. Recently studies have been carried out on the spin distributions of fission fragments through the gamma ray multiplicity measurements. ... Heavy ion fission; angular distributions; fragment spin; mass; energy. ... neutrons and protons (magic numbers), and also resulting in deformed ground state shapes.

  13. Pre-equilibrium (exciton) model and the heavy-ion reactions with cluster emission

    CERN Document Server

    Betak, E

    2015-01-01

    We bring the possibility to include the cluster emission into the statistical pre-equilibrium (exciton) model enlarged for considering also the heavy ion collisions. At this moment, the calculations have been done without treatment of angular momentum variables, but all the approach can be straightforwardly applied to heavy-ion reactions with cluster emission including the angular momentum variables. The direct motivation of this paper is a possibility of producing the superdeformed nuclei, which are easier to be detected in heavy-ion reactions than in those induced by light projectiles (nucleons, deuterons, $\\alpha$-particles).

  14. Heavy flavour production at CMS in heavy ion collisions

    CERN Document Server

    Nguyen, Matthew

    2015-01-01

    We review recent results relating to beauty production in heavy-ion collisions, in both the closed and open heavy flavor sectors, from the CMS experiment at the LHC. The sequential suppression of the ° states in PbPb collisions is thought to be evidence of the dissociation of quarkonia bound states in deconfined matter. Data from pPb collisions demonstrate that while cold nuclear effects appear to be subdominant in minimum bias collisions, there exists a non-trivial dependence on collision multiplicity that remains to be understood. The suppression of high p T particles in heavy-ion collisions, relative to the expectation from pp collisions, is typically interpreted in terms of energy loss of hard scattered parton in the dense nuclear medium. The flavor dependence of the energy loss may be accessed via measurements of b hadrons and b-tagged jets. Measurement of B mesons, via non-prompt J = y , at relatively low p T indicate a smaller suppression factor than D meson or inclusive charged hadrons. Data on b jet...

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

    NARCIS (Netherlands)

    Abelev, B.I.; Bai, Y.; Botje, M.A.J.; Braidot, E; Snellings, R.J.M.; Mischke, A.; van Leeuwen, M.; Russcher, M.J.; Peitzmann, T.; Benedosso, F.

    2009-01-01

    We present results for the measurement of ϕ meson production via its charged kaon decay channel ϕ→K+K- in Au+Au collisions at √sNN=62.4,130, and 200 GeV, and in p+p and d+Au collisions at √sNN=200 GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (|y|

  16. Resonance Model of $\\pi \\Delta \\rightarrow Y K$ for Kaon Production in Heavy Ion Collisions

    OpenAIRE

    Tsushima, K.; Huang, S. W.; Faessler, Amand

    1994-01-01

    The elementary production cross sections $\\pi \\Delta \\rightarrow Y K$ $(Y=\\Sigma,\\,\\, \\Lambda)$ and $\\pi N \\rightarrow Y K$ are needed to describe kaon production in heavy ion collisions. The $\\pi N \\rightarrow Y K$ reactions were studied previously by a resonance model. The model can explain the experimental data quite well \\cite{tsu}. In this article, the total cross sections $\\pi \\Delta \\rightarrow Y K$ at intermediate energies (from the kaon production threshold to3 GeV of $\\pi \\Delta$ ce...

  17. Heavy Flavor Production in Heavy Ion Collisions at CMS

    CERN Document Server

    Sun, Jian

    2016-01-01

    Studies of Heavy flavor production are of great interest in heavy ion collisions. In the produced medium, the binding potential between a quark and antiquark in quarkonium is screened by surrounding light quarks and antiquarks. Thus, the various quarkonium states are expected to be melt at different temperatures depending on their binding energies, which allows us to characterize the QCD phase transition. In addition, open heavy flavor production are relevant for flavor-dependence of the in-medium parton energy loss. In QCD, gluons are expected to lose more energy compared to quarks when passing through the QGP due to the larger color charge. Compared to light quarks, heavy quarks are expected to lose less radiative energy because gluon radiation is suppressed at angles smaller than the ratio of the quark mass to its energy. This dead cone effect (and its disappearance at high transverse momentum) can be studied using open heavy flavor mesons and heavy flavor tagged jets. With CMS detector, quarkonia, open he...

  18. Reexamining the heavy-ion reactions 238U+238U and 238U+248Cm and actinide production close to the barrier

    Science.gov (United States)

    Kratz, J. V.; Schädel, M.; Gäggeler, H. W.

    2013-11-01

    that identical isotope distributions are populated independent of the bombarding energy indicating that the same bins of excitation energy are responsible for the production of these fissile isotopes. A comparison of the survival probabilities of the residues of equal charge and neutron transfers in the reactions of 238U projectiles with either 238U or 248Cm targets is consistent with such a cutoff as evaporation calculations assign the surviving heavy actinides to the 3n and/or 4n evaporation channels.

  19. Classical simulations of heavy-ion fusion reactions and weakly ...

    Indian Academy of Sciences (India)

    2014-04-30

    -ion reactions with spherical and deformed nuclei are simulated in a classical rigid-body dynamics (CRBD) model which takes into account the reorientation of the deformed projectile. It is found that the barrier parameters ...

  20. Evidence for pair correlation effects in heavy ion reactions

    CERN Document Server

    Auditore, L; D'Amico, V; De Pasquale, D; Trifiró, A; Trimarchi, M; Italiano, A

    2003-01-01

    The study of the sup 1 sup 2 C( sup 1 sup 4 N, sup 1 sup 4 N) sup 1 sup 2 C reaction was performed at 28 and 35 MeV beam energies. The results were analyzed in the frame of the EFRDWBA (Exact-Finite-Range Distorted Wave Born Approximation) assuming the simultaneous and sequential transfer of a np pair. The angular distributions, fairly reproduced in the first case, confirm the validity of the generalized BCS (Bardeen-Cooper-Schrieffer) theory to explain this behaviour. Moreover, this process could be regarded as a possible Nuclear Josephson Effect. (author)

  1. Particle Production In Relativistic Heavy-ion Collisions With Perturbative Qcd

    CERN Document Server

    Zhang, Y

    2003-01-01

    The commissioning of the Relativistic Heavy Ion Collider (RHIC) opened new era in nuclear collision physics, with the study of excited strongly-interacting matter becoming a reality. A primary motivation for studying high-p T hadron production in ultrarelativistic heavy ion collisions is to gain insight into the gluon density of the quark-gluon medium via jet energy loss. The sensitivity of high-pT hadron spectra to initial gluon density may be a probe of the formation of quark-gluon-plasma (QGP). However, a thorough understanding of ultrarelativistic nuclear (AA ) collisions requires the accurate description of proton-proton ( pp) and proton-nucleus (pA) collisions in the same framework. In the present dissertation we follow the evolution of high-p T hadron production in relativistic collisions from pp to pA to AA reactions. The perturbative Quantum Chromodynamics (pQCD) improved parton model is used for the study. We apply leading- order (LO) pQCD throughout, and augment the standard one- dimensional cross ...

  2. Proceedings of the Workshop on open problems in heavy ion reaction dynamics at VIVITRON energies

    Energy Technology Data Exchange (ETDEWEB)

    Beck, F.A.

    1993-07-01

    Some problems of heavy ion reaction dynamics at the VIVITRON tandem accelerator and the experimental facilities are discussed at the meeting. Topics include light dinuclear systems, collision dynamics at low energies, fission evaporation and fusion of heavy nuclei and others. Most documents consist of transparencies presented at the workshop, texts of papers are missing. All items are indexed and abstracted for the INIS database. (K.A.).

  3. Measurement of Total Reaction Cross-sections with Heavy Ions at the SC

    CERN Multimedia

    2002-01-01

    The aim of this experiment is the measurement of heavy ion total reaction cross-sections in the energy range 40-86 MeV/A with the anti-coincidence beam attenuation technique. A system of 19 @DE scintillation detectors together with a time-of-flight measurement is used for detection of the residual beam. The results will complete measurements at the Grenoble cyclotron and post accelerator over the energy range 10-40 MeV/A.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Recent results on heavy-ion reactions in the SIS-energy regime

    Energy Technology Data Exchange (ETDEWEB)

    Metag, V. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)]|[Giessen Univ. (Germany). 2. Physikalisches Inst.

    1998-02-01

    Future heavy-ion reaction studies at RHIC and LHC aim at exploring the partonic degrees of freedom of hadronic matter at temperatures of several 100 MeV and almost vanishing net baryon densities. In contrast, experiments at SIS, i.e. in the 1 AGeV energy regime, focus on hadronic matter at temperatures below 100 MeV and baryon densities of 2-3 times normal nuclear matter density. Both experimental approaches are complementary as they allow rather different regimes in the phase diagram of hadronic matter to be studied. There are, nevertheless, several aspects of common interest, among them, e.g. the partial restoration of chiral symmetry. In general, investigations at low incident energies are required for a full, quantitative description of ultrarelativistic heavy-ion reactions as any initially formed quark-gluon plasma will go through a temperature and density range during the hadronization phase that can be directly studied at lower collision energies. This overview over heavy-ion reactions in the SIS-energy range focuses on two aspects: (i) the global features of compressed hadronic matter generated in such collisions, and (ii) evidence for medium modifications of hadrons in this hot and dense nuclear medium. (orig.) 49 refs.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Duality and Chiral Restoration from Dilepton Production in Relativistic Heavy-Ion Collisions

    CERN Document Server

    Rapp, R

    2000-01-01

    We discuss the recent status in the theoretical understanding of dilepton production in central heavy-ion reactions with the Pb-beam at the full CERN-SpS energy of 158 AGeV. In the low-mass region ($M\\le$~1 GeV) a strong broadening of the vector meson resonances in hot and dense matter (especially for the $q\\bar q$ annihilation close to the expected phase boundary of the chiral symmetry restoring transition. A consistent description of the experimentally observed enhancement at both low and intermediate masses (1.5 GeV~$\\le M \\le$~3 GeV) in terms of thermal radiation from an expanding fireball can be obtained.

  8. Resolving the Antibaryon-Production Puzzle in High-Energy Heavy-Ion Collisions

    CERN Document Server

    Rapp, R

    2001-01-01

    We argue that the observed antiproton production in heavy-ion collisions at CERN-SpS energies can be understood if (contrary to most sequential scattering approaches) the backward direction in the process $p\\bar p \\leftrightarrow \\bar{n}\\pi$ (with $\\bar{n}$=5-6) is consistently accounted for within a thermal framework. Employing the standard picture of subsequent chemical and thermal freezeout, which induces an over-saturation of pion number with associated chemical potentials of $\\mu_\\pi\\simeq$~60-80 MeV, enhances the backward reaction substantially. The resulting rates and corresponding cross sections turn out to be large enough to maintain the abundance of antiprotons at chemical freezeout until the decoupling temperature, in accord with the measured $\\bar{p}/p$ ratio in Pb(158AGeV)+Pb collisions.

  9. Measurement of quarkonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Tapia Araya, Sebastian; The ATLAS collaboration

    2017-01-01

    The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in heavy-ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions , cold nuclear effects may also affect quarkonia production . Therefore, a full assessment requires detailed studies on the effects present in both A-A and p+A collisions. Based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt J/psi and psi(2S) productions as well as Upsilon production via the di-muon decay final states. The results are of the various measurements are discussed.

  10. Measurement of quarkonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Kremer, Jakub Andrzej; The ATLAS collaboration

    2017-01-01

    The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in heavy-ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions, cold nuclear effects may also affect quarkonia production. Therefore, a full assessment requires detailed studies on the effects present in both A-A and p+A collisions. Based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt J/psi and psi(2S) productions as well as Upsilon production via the di-muon decay final states. The results of the various measurements are discussed

  11. Bottomonium production in heavy-ion collisions at STAR

    CERN Document Server

    Vertesi, Robert

    2015-01-01

    Bottomonium measurements provide unique insight into hot and cold nuclear matter effects present in the medium that is formed in high-energy heavy-ion collisions. Recent STAR results show that in $\\sqrt{s_{NN}}$ = 200 GeV central Au+Au collisions the $\\Upsilon$(1S) state is suppressed more than if only cold nuclear matter effects were present, and the excited state yields are consistent with a complete suppression. In 2012, STAR also collected 263.4 $\\mu$b$^{-1}$ high-energy-electron triggered data in U+U collisions at $\\sqrt{s_{NN}}$= 193 GeV. Central U+U collisions, with an estimated 20% higher energy density than in central Au+Au data, extend the $\\Upsilon$(1S+2S+3S) and Upsilon(1S) nuclear modification trends observed in Au+Au towards higher number of participant nucleons, and confirm the suppression of the $\\Upsilon$(1S) state. We see a hint with 1.8 sigma significance that the $\\Upsilon$(2S+3S) excited states are not completely suppressed in U+U collisions. These data support the sequential in-medium qu...

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

    Directory of Open Access Journals (Sweden)

    Hagino K.

    2016-01-01

    Full Text Available 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.

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

    Directory of Open Access Journals (Sweden)

    Hagino K.

    2016-01-01

    Full Text Available 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.

  14. Simple estimates of excitation energy sharing between heavy and light fragments in heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dasso, C.H.; Lozano, M.; Pollarolo, G.

    1985-12-01

    Qualitative arguments are used to estiamte the ratio of excitation energies between heavy and light fragments for asymmetric heavy-ion collisions. The value of this quantity is linked to the relative role played by inelastic and transfer degrees of freedom and thereby to an approximate function of the total kinetic energy loss. A numerical analysis that confirms the trends anticipated by the simple arguments is performed for the reactions /sup 56/Fe+ /sup 238/U and /sup 86/Kr+ /sup 208/Pb at bombarding energies in the laboratory of 476 and 1565 MeV, respectively.

  15. Studies of low-energy heavy-ion reactions at LNL

    Energy Technology Data Exchange (ETDEWEB)

    Stefanini, A.M.; Ackermann, D.; Corradi, L.; He, J.H. [Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Beghini, S.; Montagnoli, G.; Scarlassara, F.; Segato, G.P. [Istituto Nazionale di Fisica Nucleare, Padua (Italy)

    1995-02-01

    Recent experimental investigations on low-energy heavy-ion reaction dynamics performed at Legnaro are reviewed. A short description is given of the setup which enables the study of elastic scattering and of quasielastic transfer reactions, as well as of fusion reactions. After a brief hint on the perspectives in the field of multinucleon transfer, the main part of the lecture is dedicated to the fusion reactions for which recent developments, like the studies of barrier distributions and the theoretical approach using the Interaction Boson Model, have lead to a renewed interest. Some results obtained by our group are presented for the system {sup 32}S+ {sup 58,64}Ni, {sup 16}O+{sup 194}Pt (sensitivity to the target deformation) and {sup 58}Ni+{sup 60}Ni (evidence for multiphonon excitation in subbarrier fusion). (author). 24 refs, 8 figs.

  16. Universal trend for heavy-ion total reaction cross sections at energies above the Coulomb barrier

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P.; Medeiros, E.L., E-mail: emil@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Morcelle, V. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2010-06-15

    Heavy-ion total reaction cross section measurements for more than one thousand one hundred reaction cases covering 61 target nuclei in the range {sup 6}Li-{sup 238}U, and 158 projectile nuclei from {sup 2}H up to {sup 84}Kr (mostly exotic ones) have been analysed in a systematic way by using an empirical, three-parameter formula which is applicable to cases for projectile kinetic energies above the Coulomb barrier. The analysis has shown that the average total nuclear binding energy per nucleon of the interacting nuclei and their radii are the chief quantities which describe the cross section patterns. A great number of cross section data (87%) has been quite satisfactorily reproduced by the proposed formula, therefore total reaction cross section predictions for new, not yet experimentally investigated reaction cases can be obtained within 25 percent (or much less) of uncertainty (author)

  17. Photon and dilepton production in high-energy heavy-ion collisions

    Indian Academy of Sciences (India)

    2015-05-07

    May 7, 2015 ... Hard production of photons and dileptons. One of the big successes in electromagnetic radiation measurements in relativistic heavy- ion collisions is the observation of high pT direct photons that are produced in the initial hard scattering [9]. Figures 4a and 4b show the latest direct photon pT spectra in Au+ ...

  18. The First LHC p-Pb Run: Performance of the Heavy Ion Production Complex

    CERN Document Server

    Manglunki, D; Bartosik, H; Bellodi, G; Blas, A; Bodendorfer, M; Bohl, T; Carli, C; Carlier, E; Cettour-Cave, S; Cornelis, K; Damerau, H; Findlay, A; Gilardoni, S; Hancock, S; Jowett, J; Küchler, D; O'Neil, M; Papaphilippou, Y; Pasinelli, S; Scrivens, R; Tranquille, G; Vandorpe, B; Wehrle, U; Wenninger, J

    2013-01-01

    The first LHC proton-ion run took place in January-February 2013; it was the first extension to the collider programme, as this mode was not included in the design report. This paper presents the performance of the heavy ion and proton production complex, and details the issues encountered, in particular the creation of the same bunch pattern in both beams.

  19. A spectrometer for study of high mass objects created in relativistic heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.A.; Barish, K.N.; Batsouli, S.; Bennett, M.J.; Bennett, S.J.; Chikanian, A.; Coe, S.D.; Cormier, T.M.; Davies, R.R.; De Cataldo, G.; Dee, P.; Diebold, G.E.; Dover, C.B.; Ewell, L.A.; Emmet, W.; Fachini, P.; Fadem, B.; Finch, L.E.; George, N.K.; Giglietto, N.; Greene, S.V.; Haridas, P.; Hill, J.C. E-mail: jhill@iastate.edu; Hirsch, A.S.; Hoversten, R.A.; Huang, H.Z.; Jaradat, H.; Kim, B.; Kumar, B.S.; Lajoie, J.G.; Lainis, T.; Lewis, R.A.; Li, Q.; Li, Y.; Libby, B.; Majka, R.D.; Miller, T.E.; Munhoz, M.G.; Nagle, J.L.; Petridis, A.; Pless, I.A.; Pope, J.K.; Porile, N.T.; Pruneau, C.; Rabin, M.S.Z.; Reid, J.D.; Rimai, A.; Riso, J.; Rose, A.; Rotondo, F.S.; Sandweiss, J.; Scharenberg, R.P.; Skank, H.; Slaughter, A.J.; Sleage, G.; Smith, G.A.; Spinelli, P.; Srivastava, B.K.; Tincknell, M.L.; Toothacker, W.S.; Van Buren, G.; Wilson, W.K.; Wohn, F.K.; Wolin, E.J.; Xu, Z.; Zhao, K

    1999-11-21

    Experiment E864 at the Brookhaven AGS accelerator uses a high sensitivity, large acceptance spectrometer, designed to search for strangelets and other novel forms of matter produced in high-energy heavy ion collisions. The spectrometer has excellent acceptance and rate capabilities for measuring the production properties of known particles and nuclei such as p-bar, d-bar and {sup 6}He. The experiment uses a magnetic spectrometer and employs redundant time of flight and position detectors and a hadronic calorimeter. In this paper we describe the design and performance of the spectrometer.

  20. A kinematic coincidence technique for the study of low-energy heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Corradi, L.; Montagnoli, G.; Napoli, D.R.; Spolaore, P.; Stefanini, A.M.; Xu Jincheng (Istituto Nazionale di Fisica Nucleare, Padua (Italy). Lab. di Legnaro); Beghini, S.; Scarlassara, F.; Segato, G.F.; Soramel, F. (Padua Univ. (Italy). Dipt. di Fisica Istituto Nazionale di Fisica Nucleare, Padua (Italy)); Signorini, C. (Salerno Univ. (Italy). Dipt. di Fisica Istituto Nazionale di Fisica Nucleare, Padua (Italy))

    1990-12-10

    A setup for kinematic coincidences has been developed for the study of low-energy binary heavy-ion reactions. It consists of a position-sensitive silicon detector, and a counter telescope with microchannel plates detectors and a conventional {Delta}E-E ionization chamber. The solid angle is around 0.6 msr. By measuring the time of flight of one of the ions, and both correlated scattering angles, we achieve mass and Q-value resolutions of {Delta}A/A{approx equal}1/120 FWHM and {Delta}Q{approx equal}900 keV, respectively, for the elastic scattering of {sup 58}Ni+{sup 64}Ni near the barrier. (orig.).

  1. TWAC facility and the use of the laser ion source for production of intense heavy ion beams

    CERN Document Server

    Sharkov, B Yu; Shumshurov, A V; Meshcheryakov, N D; Rudskoy, I; Homenko, S; Makarov, K; Rörich, V; Stepanov, A; Satov, Yu A; Haseroth, H; Kugler, H; Lisi, N; Scrivens, R

    1999-01-01

    Current activities on upgrading of the ITEP heavy ion accelerator complex in the framework of the ITEP-TWAC project are reported. The project being in progress since 1997 is aiming at production of intense (100 kJ/100 ns) heavy ion beams. The basic idea of the project is the application of the non-Liouvillian technique in an existing accelerator facility based on a heavy ion synchrotron for its adaptation to heavy ion fusion related experiments. Special attention is paid to the results on generation of highly charged medium mass and heavy ions in the laser produced plasma. Development of key elements of the laser ion source based on the use of a 100 J repetition rate CO/sub 2/-laser for filling of ITEP and CERN accelerator facilities in the single turn injection mode is presented. (4 refs).

  2. Detector system for the study of low energy heavy ion reactions using kinematic coincidence technique

    Science.gov (United States)

    Jhingan, Akhil; Kalkal, S.; Sugathan, P.; Golda, K. S.; Ahuja, R.; Gehlot, J.; Madhavan, N.; Behera, B. R.; Mandal, S. K.

    2014-05-01

    The characteristics and performance of a new detector system developed for the study of low energy heavy ion binary reactions using the kinematic coincidence technique are presented. The detector system has been developed to carry out experiments such as multi-nucleon transfer reactions using the General Purpose Scattering Chamber (GPSC) facility at IUAC [1,2]. The detector system consists of a pair of two-dimensional position sensitive multi wire proportional counter (MWPC) and a ΔE - E gas ionization chamber. Both MWPC have an active area of 5×5 cm2, and provide position signals in horizontal (X) and vertical (Y) plane, and timing signal for time of flight measurements. The main design feature of MWPC is the reduced wire pitch of 0.025 in. (0.635 mm) in all electrodes, giving uniform field and faster charge collection, and usage of 10 μm diameter in anode frame which gives higher gains. The position resolution of the detectors was determined to be 0.45 mm FWHM and time resolution was estimated to be 400 ps FWHM. The detector could handle heavy ion count rates exceeding 100 kHz without any break down. The timing and position signals of the detectors are used for kinematic coincidence measurements and subsequent extraction of their mass and angular distributions. The ionization chamber has a conventional transverse field geometry with segmented anode providing multiple ΔE signals for nuclear charge (Z) identification. This article describes systematic study of these detectors in terms of efficiency, count rate handling capability, time, position and energy resolution.

  3. Detector system for the study of low energy heavy ion reactions using kinematic coincidence technique

    Energy Technology Data Exchange (ETDEWEB)

    Jhingan, Akhil, E-mail: akhil@iuac.res.in [Inter University Accelerator Centre, P. O. Box 10502, New Delhi 110067 (India); Kalkal, S. [Deptartment of Physics and Astrophysics, Delhi University, Delhi 110007 (India); Sugathan, P.; Golda, K.S.; Ahuja, R.; Gehlot, J.; Madhavan, N. [Inter University Accelerator Centre, P. O. Box 10502, New Delhi 110067 (India); Behera, B.R. [Deptartment of Physics, Panjab University, Chandigarh 160014 (India); Mandal, S.K. [Deptartment of Physics and Astrophysics, Delhi University, Delhi 110007 (India)

    2014-05-01

    The characteristics and performance of a new detector system developed for the study of low energy heavy ion binary reactions using the kinematic coincidence technique are presented. The detector system has been developed to carry out experiments such as multi-nucleon transfer reactions using the General Purpose Scattering Chamber (GPSC) facility at IUAC [1,2]. The detector system consists of a pair of two-dimensional position sensitive multi wire proportional counter (MWPC) and a ΔE−E gas ionization chamber. Both MWPC have an active area of 5×5 cm{sup 2}, and provide position signals in horizontal (X) and vertical (Y) plane, and timing signal for time of flight measurements. The main design feature of MWPC is the reduced wire pitch of 0.025 in. (0.635 mm) in all electrodes, giving uniform field and faster charge collection, and usage of 10μm diameter in anode frame which gives higher gains. The position resolution of the detectors was determined to be 0.45 mm FWHM and time resolution was estimated to be 400 ps FWHM. The detector could handle heavy ion count rates exceeding 100 kHz without any break down. The timing and position signals of the detectors are used for kinematic coincidence measurements and subsequent extraction of their mass and angular distributions. The ionization chamber has a conventional transverse field geometry with segmented anode providing multiple ΔE signals for nuclear charge (Z) identification. This article describes systematic study of these detectors in terms of efficiency, count rate handling capability, time, position and energy resolution.

  4. Measurement of quarkonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Kremer, Jakub Andrzej; The ATLAS collaboration

    2017-01-01

    The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in nucleus-nucleus collisions at the LHC. In addition to hot matter effects in heavy-ion collisions, cold nuclear effects may also affect quarkonia production. Therefore, a full assessment requires detailed studies on the effects present in both A+A and $\\textit{p}$+A collisions. Based on $\\textit{p}$+Pb data collected in 2013 and $\\textit{pp}$ and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt $J/\\psi$ and $\\psi\\left(2\\mathrm{S}\\right)$ productions as well as $\\Upsilon\\left(n\\mathrm{S}\\right)$ production via the di-muon decay final states. The results of the various measurements are discussed.

  5. D meson production in heavy ion collisions with CMS

    CERN Document Server

    Kim, Hyunchul

    2016-01-01

    The nuclear modification factor, $R_{\\text{AA}}$, of the $D^0$ meson production has been measured in pp and PbPb collisions at $\\sqrt{s_{NN}}~=~2.76$ TeV and 5.02 TeV with CMS detector. This measurement is important in investigating the properties of the high-density QCD (quantum chromodynamics) matter. The dependence on the centrality and transverse momentum up to 100 GeV were presented in a poster at this conference.

  6. Lanthanides in Nuclear Medicine. The Production of Terbium-149 by Heavy Ion Beams

    CERN Document Server

    Dmitriev, S N; Zaitseva, N G; Maslov, O D; Molokanova, L G; Starodub, G Ya; Shishkin, S V; Shishkina, T V

    2001-01-01

    Among radioactive isotopes of lanthanide series elements, finding the increasing using in nuclear medicine, alpha-emitter {149}Tb (T_{1/2} = 4.118 h; EC 76.2 %; beta^+ 7.1 %; alpha 16.7 %) is considered as a perspective radionuclide for radioimmunotherapy. The aim of the present work is to study experimental conditions of the {149}Tb production in reactions Nd({12}C, xn){149}Dy (4.23 min; beta^+, EC)\\to {149}Tb when the Nd targets have been irradiated by heavy ions of carbon. On the basis of results of formation and decay of {149}Dy\\to{149}Tb evaluation of the {149}Tb activity, is made which can be received under optimum conditions (enriched {142}Nd target, {12}C ions with the energy 120 MeV and up to current 100 mu A, time of irradiating 8-10 hours). Under these conditions {149}Tb can be obtained up to 30 GBq (up to 0.8 Ci).

  7. Particle Production in Strong Electromagnetic Fields in Relativistic Heavy-Ion Collisions

    Directory of Open Access Journals (Sweden)

    Kirill Tuchin

    2013-01-01

    Full Text Available I review the origin and properties of electromagnetic fields produced in heavy-ion collisions. The field strength immediately after a collision is proportional to the collision energy and reaches ~mπ2 at RHIC and ~10mπ2 at LHC. I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma lives as a consequence of finite electrical conductivity of the plasma. Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane, and therefore all kinetic coefficients are anisotropic. I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry. Very strong electromagnetic field has an important impact on particle production. I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate J/ψ dissociation via Lorentz ionization mechanism, and examine electromagnetic radiation by plasma. I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation.

  8. Measurement of charmonium production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00511724; The ATLAS collaboration

    2017-01-01

    The suppression of heavy charmonia states in heavy-ion collisions is a phenomenon understood as a consequence of quark gluon plasma formation in the hot, dense system formed in heavy ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions, cold nuclear effects may also affect heavy charmonia production. Therefore, a full assessment requires detailed studies on the effects present in both A+A and p+A collisions. Based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt $J/\\psi$ and $\\psi$(2S) productions via the dimuon decay final states. The production and excited-to-ground state ratios of heavy charmonia measured in both p+Pb and Pb+Pb collision data with respect to that measured in pp collision data will be presented in intervals of transverse momentum, rapidity and centrality.

  9. Measurement of charmonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Lopez, Jorge; The ATLAS collaboration

    2017-01-01

    The suppression of heavy charmonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in heavy ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions , cold nuclear effects may also affect heavy charmonia production . Therefore, a full assessment requires detailed studies on the effects present in both A+A and p+A collisions. Based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt $J/\\psi$ and $\\psi(2S)$ productions via the di-muon decay final states. The production and excited-to-ground state ratios of heavy charmonia measured in both p+Pb and Pb+Pb collision data with respect to that measured in pp collision data will be presented in intervals of transverse momentum, rapidity and centrality.

  10. Latest Results From the HypHI Experiments at GSI : Hypernuclear Spectroscopy with Heavy Ion Induced Reactions

    NARCIS (Netherlands)

    Saito, T. R.; Kim, E.; Nakajima, D.; Rappold, C.; Bianchin, S.; Borodina, O.; Bozkurt, V.; Kavatsyuk, M.; Ma, Y.; Maas, F.; Minami, S.; Ozel-Tashenov, B.; Yoshida, K.

    The HypHI Phase 0 experiment with Li-6 projectiles at 2 AGeV on a carbon target has been performed at GSI in order to demonstrate the feasibility of hypernuclear spectroscopy with induced reaction of heavy ion beams. Current data analyses have shown peaks in invariant mass distributions of p + pi

  11. Entropy production and effective viscosity in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu.B. [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); National Research Nuclear University ' ' MEPhI' ' (Moscow Engineering Physics Institute), Moscow (Russian Federation); Soldatov, A.A. [National Research Nuclear University ' ' MEPhI' ' (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2016-12-15

    The entropy production and an effective viscosity in central Au+Au collisions are estimated in a wide range of incident energies 3.3 GeV ≤ √(s{sub NN}) ≤ 39 GeV. The simulations are performed within a three-fluid model employing three different equations of state with and without deconfinement transition, which are equally good in the reproduction of the momentum-integrated elliptic flow of charged particles in the considered energy range. It is found that more than 80% entropy is produced during a short early collision stage which lasts ∝ 1 fm/c at the highest considered energies √(s{sub NN}) >or similar 20 GeV. The estimated values of the viscosity-to-entropy ratio (η/s) are approximately the same in all considered scenarios. At the final stages of the system expansion they range from ∝ 0.05 at the highest considered energies to ∝ 0.5 at the lowest ones. It is found that the η/s ratio decreases with the temperature (T) rise, approximately as ∝ 1/T{sup 4}, and exhibits a rather weak dependence on the net-baryon density. (orig.)

  12. Subthreshold Production of Neutral Pions in Heavy Ion Collisions

    CERN Multimedia

    2002-01-01

    The pion production below the threshold at 290 MeV/u (corresponding to the minimum beam velocity at which pions can be produced in nucleon-nucleon collisions) is sensitive to coherent effects in the momentum distribution of the nucleons in the internuclear collision region. Such collective or coherent effects would manifest themselves in an enhancement of the observed cross section with respect to a prediction on the basis of model momentum distributions, e.g. from the Fermi gas model. \\\\ \\\\ With neutral pions such experiments can be extended to rather low energies and rather small cross sections (in the sub-@mb range) due to the fact that the @p|0's leave the composite nuclear system undisturbed by the Coulomb forces and that their decay $\\gamma$ rays can be detected with high efficiency also at very low pion momentum. In our experiments using |1|2C~ions of 60, 74 and 84~MeV/u and |1|80 of 84~MeV/u we were able to clearly sep from background from different sources. The large efficiency of the annular lead gl...

  13. A Review on ϕ Meson Production in Heavy-Ion Collision

    Directory of Open Access Journals (Sweden)

    Md. Nasim

    2015-01-01

    Full Text Available The main aim of the relativistic heavy-ion experiment is to create extremely hot and dense matter and study the QCD phase structure. With this motivation, experimental program started in the early 1990s at the Brookhaven Alternating Gradient Synchrotron (AGS and the CERN Super Proton Synchrotron (SPS followed by Relativistic Heavy Ion Collider (RHIC at Brookhaven and recently at Large Hadron Collider (LHC at CERN. These experiments allowed us to study the QCD matter from center-of-mass energies (sNN 4.75 GeV to 2.76 TeV. The ϕ meson, due to its unique properties, is considered as a good probe to study the QCD matter created in relativistic collisions. In this paper we present a review on the measurements of ϕ meson production in heavy-ion experiments. Mainly, we discuss the energy dependence of ϕ meson invariant yield and the production mechanism, strangeness enhancement, parton energy loss, and partonic collectivity in nucleus-nucleus collisions. Effect of later stage hadronic rescattering on elliptic flow (v2 of proton is also discussed relative to corresponding effect on ϕ meson v2.

  14. Charged Particle, Photon Multiplicity, and Transverse Energy Production in High-Energy Heavy-Ion Collisions

    Directory of Open Access Journals (Sweden)

    Raghunath Sahoo

    2015-01-01

    Full Text Available We review the charged particle and photon multiplicities and transverse energy production in heavy-ion collisions starting from few GeV to TeV energies. The experimental results of pseudorapidity distribution of charged particles and photons at different collision energies and centralities are discussed. We also discuss the hypothesis of limiting fragmentation and expansion dynamics using the Landau hydrodynamics and the underlying physics. Meanwhile, we present the estimation of initial energy density multiplied with formation time as a function of different collision energies and centralities. In the end, the transverse energy per charged particle in connection with the chemical freeze-out criteria is discussed. We invoke various models and phenomenological arguments to interpret and characterize the fireball created in heavy-ion collisions. This review overall provides a scope to understand the heavy-ion collision data and a possible formation of a deconfined phase of partons via the global observables like charged particles, photons, and the transverse energy measurement.

  15. Inelastic collisions of heavy ions and their reaction mechanisms; Collisions inelastiques d'ions lourds et mecanismes de reaction

    Energy Technology Data Exchange (ETDEWEB)

    Scarpaci, J.A

    2004-06-01

    This work is dedicated to the study of inelastic collisions of heavy ions. Most experiments took place in Ganil facility. The 2 first chapters introduce the notion of inelastic scattering of heavy ions. The third chapter deals with target excitation, giant monopolar or dipolar or quadrupolar resonances ant the multi-phonon concept and presents relevant experimental results from the Ca{sup 40} + Ca{sup 40} nuclear reaction at 50 MeV/A. The fourth chapter is dedicated to nuclear processes involved in inelastic collisions: pick-up break-up mechanisms, the angular distribution of emitted protons and the towing mode. These notions are applied to the reaction Zr{sup 90}(Ar{sup 40}, Ar{sup 40}'). The fifth chapter presents the solving of the time dependent Schroedinger equation (TDSE) applied to the wave function of a particle plunged in a variable potential. TDSE solving is applied to the break-up of Be{sup 11}. These calculations have been validated by comparing them with experimental results from the nuclear reaction Ti{sup 48}(Be{sup 11}, Be{sup 10} + n + {gamma}) that is described in the chapter 6. The last chapter presents the advantages of inelastic scattering considered as a tool to study exotic nuclei.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Recent experimental results in sub- and near-barrier heavy-ion fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Montagnoli, Giovanna [Dipartimento di Fisica e Astronomia, Universita di Padova (Italy); INFN Sezione di Padova (Italy); Stefanini, Alberto M. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy)

    2017-08-15

    Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus is mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations overpredict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars. (orig.)

  18. Differences in high $p_{t}$ meson production between CERN SPS and RHIC heavy ion collisions

    CERN Document Server

    Papp, G; Barnafoldi, G G; Yi Zhang; Fái, G; Papp, Gabor; Levai, Peter; Barnafoldi, Gergely G.; Zhang, Yi; Fai, George

    2001-01-01

    In this talk we present a perturbative QCD improved parton model calculation for light meson production in high energy heavy ion collisions. In order to describe the experimental data properly, one needs to augment the standard pQCD model by the transverse momentum distribution of partons ("intrinsic k/sub T/"). Proton-nucleus data indicate the presence of nuclear shadowing and multi-scattering effects. Further corrections are needed in nucleus-nucleus collisions to explain the observed reduction of the cross section. We introduce the idea of proton dissociation and compare our calculations with the SPS and RHIC experimental data. (18 refs).

  19. Vector mesons in dense matter and dilepton production in heavy ion collisions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Santini, Elvira

    2008-02-15

    The vector meson spectral functions are calculated to the first order in the nuclear matter density assuming the dominant contribution comes from the couplings of the vector mesons to nucleons and nucleon resonances. An attempt is made to reproduce the HADES dilepton production data with the in-medium spectral functions of the vector mesons using the Relativistic Quantum Molecular Dynamics (RQMD) transport model developed earlier for modelling heavy-ion collisions. The results are sensitive to the in-medium broadening of nucleon resonances. A generally good agreement with the HADES data is achieved for selfconsistent treatment of the nucleon resonance broadening and the vector meson spectral functions. (orig.)

  20. Implementation of TTIK method and time of flight for resonance reaction studies at heavy ion accelerator DC-60

    Energy Technology Data Exchange (ETDEWEB)

    Nurmukhanbetova, A.K. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Goldberg, V.Z. [Cyclotron Institute, Texas A& M University, College Station, TX (United States); Nauruzbayev, D.K. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Saint Petersburg State University, Saint Petersburg (Russian Federation); Rogachev, G.V. [Cyclotron Institute, Texas A& M University, College Station, TX (United States); Golovkov, M.S. [Joint Institute of Nuclear Research, Dubna (Russian Federation); Dubna State University, Dubna (Russian Federation); Mynbayev, N.A. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Artemov, S.; Karakhodjaev, A. [Institute of Nuclear Physics, Tashkent (Uzbekistan); Kuterbekov, K. [L.N. Gumilov Eurasian National University, Astana (Kazakhstan); Rakhymzhanov, A. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Berdibek, Zh. [School of Science and Technology, Nazarbayev University, Astana (Kazakhstan); Ivanov, I. [Institute of Nuclear Physics, Astana (Kazakhstan); Tikhonov, A. [School of Science and Technology, Nazarbayev University, Astana (Kazakhstan); Zherebchevsky, V.I.; Torilov, S. Yu. [Saint Petersburg State University, Saint Petersburg (Russian Federation); Tribble, R.E. [Cyclotron Institute, Texas A& M University, College Station, TX (United States)

    2017-03-01

    To study resonance reactions of heavy ions at low energy we have combined the Thick Target Inverse Kinematics Method (TTIK) with Time of Flight method (TF). We used extended target and TF to resolve the identification problems of various possible nuclear processes inherent to the simplest popular version of TTIK. Investigations of the {sup 15}N interaction with hydrogen and helium gas targets by using this new approach are presented.

  1. Measurement of quarkonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Tapia Araya, Sebastian; The ATLAS collaboration

    2017-01-01

    The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system produced in interactions of heavy ions at high energy. In addition to hot matter effects, cold nuclear effects can play an important role in quarkonia production. Therefore, a full assessment of different physics scenarios requires detailed studies on the effects present in Pb+Pb and p+Pb collisions in comparison to the pp collisions. Results of the studies based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC by the ATLAS experiment at the centre of mass energy of 5.02 TeV allowed studying prompt and non-prompt J/ψ and ψ(2S) productions as well as Υ(nS) (n = 1, 2, 3) production via the di-muon decay final states. The results of the measurements presented as a function rapidity and transverse momentum as well as the ratios between different species and systems are presented and discussed in the talk.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. New results on Coulomb effects in meson production in relativistic heavy ion collisions

    Directory of Open Access Journals (Sweden)

    Rybicki Andrzej

    2014-01-01

    Full Text Available We propose a new method of investigating the space-time evolution of meson production in heavy ion collisions, by making use of spectator-induced electromagnetic (“Coulomb” effects. The presence of two nuclear remnants (“spectator systems” in the non-central collision generates a strong Coulomb field, which modifies the trajectories of charged final state hadrons. This results in charge-dependent azimuthal anisotropies in final state meson emission. In our approach, this effect can be computed numerically by means of a high-statistics Monte Carlo simulation, using the distance between the meson formation zone and the spectator system as free parameter. Our simulation correctly describes the electromagnetic effect on azimuthal anisotropies observed for π+ and π−mesons in Au+Au collisions at lower RHIC energy, known from data recently reported by the STAR Collaboration. Similarly to our earlier studies of spectator-induced electromagnetic effects, also in the present study we find that these effects offer sensitivity to the position of the meson formation zone with respect to the spectator system. Therefore, we conclude that they can serve as a new tool to investigate the space-time evolution of meson production, and the dynamics of the heavy ion collision.

  4. Universal behavior of charged particle production in heavy ion collisions at RHIC energies

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, Peter A.; Back, B.B.; Baker, M.D.; Barton, D.S.; Betts, R.R.; Ballintijn, M.; Bickley, A.A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M.P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G.A.; Henderson, C.; Hofman, D.J.; Hollis, R.S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C.M.; Lin, W.T.; Manly, S.; McLeod, D.; Michalowski, J.; Mignerey, A.C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I.C.; Pernegger, H.; Reed, C.; Remsberg, L.P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S.G.; Steinberg, P.; Stephans, G.S.F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G.J. van; Verdier, R.; Wadsworth, B.; Wolfs, F.L.H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A.H.; Wyslouch, B

    2003-04-01

    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 kinds of universal behavior are observed in 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/p-barp 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. This feature may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  5. Bottomonium production with statistical hadronization in heavy-ion collisions at collider energies

    CERN Document Server

    Byungsik, Hong

    2004-01-01

    We present the bottomonium production estimated by using the hybrid model that combines direct bb pair creation in hard scattering and a statistical hadronization of the deconfined quark-gluon plasma. Complete color screening and full equilibration of the deconfined quark matter is assumed in the quark-gluon plasma phase. An enhanced production of the Upsilon (1S) state is predicted at collider energies. However, a significant, difference between the RHIC (Relativistic Heavy Ion Collider) and the LHC (Large Hadron Collider) is expected in the centrality dependence of the Upsilon (1S) production. Normalizing the Upsilon (1S) production by the average number of binary collisions, we expect about a factor of five decrease from half-overlap to central collisions at the RHIC, but almost no change at the LHC. Plans for measuring the bottomonium production cross-sections in future collider experiments are summarized. (28 refs).

  6. Simultaneous production of lepton pairs in ultraperipheral relativistic heavy ion collisions

    Science.gov (United States)

    Kurban, E.; Güçlü, M. C.

    2017-10-01

    We calculate the total cross sections and probabilities of electromagnetic productions of electron, muon, and tauon pairs simultaneously. At the CERN Large Hadron Collider (LHC), the available electromagnetic energy is sufficient to produce all kinds of leptons coherently. The masses of muons and tauons are large, so their Compton wavelengths are small enough to interact with the colliding nuclei. Therefore, the realistic nuclear form factors are included in the calculations of electromagnetic pair productions. The cross section calculations show that, at LHC energies, the probabilities of simultaneous productions of all kinds of leptons are increased significantly compared to energies available at the BNL Relativistic Heavy Ion Collider (RHIC) . Experimentally, observing this simultaneous production can give us important information about strong QED.

  7. Defect production and annihilation in metals through electronic excitation by energetic heavy ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Iwase, Akihiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    Defect production, radiation annealing and defect recovery are studied in Ni and Cu irradiated with low-energy ({approx}1-MeV) and high-energy ({approx}100-MeV) ions. Irradiation of Ni with {approx}100-MeV ions causes an anomalous reduction, or even a complete disappearance of the stage-I recovery. This result shows that the energy transferred from excited electrons to lattice atoms through the electron-lattice interaction contributes to the annihilation of the stage-I interstitials. This effect is also observed in Ni as a large radiation annealing during 100-MeV heavy ion irradiation. On the other hand, in Cu thin foils, we find the defect production process strongly associated with electron excitation, where the defect production cross section is nearly proportional to S{sub e}{sup 2}. (author)

  8. D$^{0}$ Meson Production in Heavy Ion Collisions in CMS experiment

    CERN Document Server

    Wang, Jing

    2016-01-01

    The measurement of heavy flavour production is a powerful tool to study the properties of the high-density QCD medium created in heavy-ion collisions as heavy quarks are sensitive to the transport properties of the medium and may interact with the QCD matter differently from light quarks. In particular, the comparison between the nuclear modification factors of light and heavy flavoured particles provides insights into the expected flavour dependence of in-medium parton energy loss. With the CMS detector, the D$^{0}$ meson production is studied in pp and PbPb collisions at 2.76 and 5.02 TeV. In this talk, the nuclear modification factor of D$^{0}$ meson are presented and compared to the charged hadron nuclear modification factor and theoretical calculations.

  9. Double scattering production of two positron–electron pairs in ultraperipheral heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Mariola Kłusek-Gawenda

    2016-12-01

    Full Text Available We present first measurable predictions for electromagnetic (two-photon double scattering production of two positron–electron pairs in ultraperipheral heavy-ion collisions at LHC. Measurable cross sections are obtained with realistic cuts on electron/positron (pseudorapidities and transverse momenta for the ALICE and ATLAS or CMS experiments. The predictions for total and differential cross sections are presented. We show also two-dimensional distributions in rapidities of the opposite-sign (from the same or different subcollisions and of the same-sign (e+e+ or e−e− electrons and in rapidity distance between them. Expected number of events are presented and discussed. Our calculations strongly suggest that relevant measurements with the help of ATLAS, CMS and ALICE detectors are possible in a near future. We show and compare energy dependence of the cross sections for one-pair and two-pair production.

  10. Measurements of secondary neutrons producted from thick targets bombarded by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, T.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Nakao, N.; Shibata, T.; Uwamino, Y.; Nakanishi, N.; Fukumura, A.; Kumamoto, Y.

    1997-03-01

    We measured neutron angular and energy distributions from high energy heavy ions stopping in targets of carbon, aluminum, copper and lead at HIMAC. These spectra are much harder for the lighter target nucleus like carbon. This means that the momentum transfer in the forward direction from heavy ion beam to lighter nuclei is much higher than that to heavier nuclei. (author)

  11. Photon and dilepton production in high-energy heavy-ion collisions

    Indian Academy of Sciences (India)

    2015-05-07

    May 7, 2015 ... The recent results on direct photons and dileptons in high-energy heavy-ion collisions, obtained particularly at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (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 ...

  12. Latest results on $\\Upsilon$ production in heavy-ion collisions from the STAR experiment

    CERN Document Server

    Vertesi, Robert

    2016-01-01

    We report on the latest measurements of the production of $\\Upsilon$ mesons in heavy-ion collisions from the STAR experiment at RHIC. New measurements of the nuclear modification factors of the $\\Upsilon$(1S+2S+3S) and $\\Upsilon$(1S) states in U+U collisions at $\\sqrt{s_{NN}}$ = 193 GeV are presented as a function of the number of participants ($N_{part}$) in the collisions. In addition, the suppression of $\\Upsilon$(1S) and $\\Upsilon$(2S+2S) is presented versus the quark-antiquark binding energy. Preliminary results on Upsilon suppression in Au+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV, reconstructed via the dimuon channel, are also reported.

  13. Direct photon production in high-energy heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Manko, V.; Aggarwal, M.M.; Agnihotri, A.; Ahammed, Z.; Angelis, A.L.S.; Antonenko, V.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Awes, T.C.; Baba, P.V.K.S.; Badyal, S.K.; Baldine, A.; Barabach, L.; Barlag, C.; Bathe, S.; Batiounia, B.; Bernier, T.; Bhalla, K.B.; Bhatia, V.S.; Blume, C.; Bock, R.; Bohne, E.-M.; Boeroecz, Z.; Bucher, D.; Buijs, A.; Buesching, H.; Carlen, L.; Chalyshev, V.; Chattopadhyay, S.; Cherbatchev, R.; Chujo, T.; Claussen, A.; Das, A.C.; Decowski, M.P.; Djordjadze, V.; Donni, P.; Doubovik, I.; Dutt, S.; Majumdar, M.R. Dutta; El Chenawi, K.; Eliseev, S.; Enosawa, K.; Foka, P.; Fokin, S.; Frolov, V.; Ganti, M.S.; Garpman, S.; Gavrischuk, O.; Geurts, F.J.M.; Ghosh, T.K.; Glasow, R.; Gupta, S. K.; Guskov, B.; Gustafsson, H. A.; Gutbrod, H. H.; Higuchi, R.; Hrivnacova, I.; Ippolitov, M.; Kalechofsky, H.; Kamermans, R.; Kampert, K.-H.; Karadjev, K.; Karpio, K.; Kato, S.; Kees, S.; Kim, H.; Kolb, B. W.; Kosarev, I.; Koutcheryaev, I.; Kruempel, T.; Kugler, A.; Kulinich, P.; Kurata, M.; Kurita, K.; Kuzmin, N.; Langbein, I.; Lebedev, A.; Lee, Y.Y.; Loehner, H.; Luquin, L.; Mahapatra, D.P.; Martin, M.; Maximov, A.; Mehdiyev, R.; Mgebrichvili, G.; Miake, Y.; Mikhalev, D.; Mir, Md.F.; Mishra, G.C.; Miyamoto, Y.; Morrison, D.; Mukhopadhyay, D. S.; Myalkovski, V.; Naef, H.; Nandi, B. K.; Nayak, S. K.; Nayak, T. K.; Neumaier, S.; Nianine, A.; Nikitine, V.; Nikolaev, S.; Nilsson, P.; Nishimura, S.; Nomokonov, P.; Nystrand, J.; Obenshain, F.E.; Oskarsson, A.; Otterlund, I.; Pachr, M.; Parfenov, A.; Pavliouk, S.; Peitzmann, T.; Petracek, V.; Plasil, F.; Pinanaud, W.; Purschke, M.L.; Raeven, B.; Rak, J.; Raniwala, R.; Raniwala, S.; Ramamurthy, V.S.; Rao, N.K.; Retiere, F.; Reygers, K.; Roland, G.; Rosselet, L.; Roufanov, I.; Roy, C.; Rubio, J.M.; Sako, H.; Sambyal, S.S.; Santo, R.; Sato, S.; Schlagheck, H.; Schmidt, H.-R.; Shabratova, G.; Shah, T.H.; Sibiriak, I.; Siemiarczuk, T.; Silvermyr, D.; Sinha, B.C.; Slavine, N.; Soederstroem, K. [and others

    1999-07-26

    Direct thermal photons in the p{sub t} range of 0 - 5 GeV/c are expected to provide a sensitive probe of the hot dense matter formed in the early stage of relativistic heavy ion collisions. The production of single photons in 158 AGeV Pb+Pb interactions has been studied with the 10080 detector lead glass calorimeter of the WA98 experiment at CERN. Neutral {pi}{sup 0} cross section has been measured via its two-photon decay branch. At p{sub t} {>=}{approx}GeV/c single photon yields of {approx}20% of the decay photon yields are observed consistently with different photon identification criteria both for the peripheral and central events.

  14. A New Two-Component Model for Hadron Production in Heavy-Ion Collisions

    Directory of Open Access Journals (Sweden)

    Xuejiao Yin

    2017-01-01

    Full Text Available Using the experimental data from the ALICE program on the centrality dependence of the transverse momentum (pT spectra in Pb+Pb collisions at sNN=2.76 TeV, we show that the double-Tsallis distribution and the generalized Fokker-Planck (FP solution cannot describe the spectra of pions, kaons, and protons from central to peripheral collisions in the entire pT region, simultaneously. Hence, a new two-component distribution, which is a hydrodynamic extension of the generalized FP solution accounting for the collective motion effect in heavy-ion collisions, is proposed in order to reproduce all the identified particle spectra. Our results suggest that the particle production dynamics may be different for different particles, especially at very low pT region.

  15. Probing QCD critical fluctuations from light nuclei production in relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Kai-Jia Sun

    2017-11-01

    Full Text Available Based on the coalescence model for light nuclei production, we show that the yield ratio Op-d-t=NH3Np/Nd2 of p, d, and 3H in heavy-ion collisions is sensitive to the neutron relative density fluctuation Δn=〈(δn2〉/〈n〉2 at kinetic freeze-out. From recent experimental data in central Pb+Pb collisions at sNN=6.3 GeV, 7.6 GeV, 8.8 GeV, 12.3 GeV and 17.3 GeV measured by the NA49 Collaboration at the CERN Super Proton Synchrotron (SPS, we find a possible non-monotonic behavior of Δn as a function of the collision energy with a peak at sNN=8.8 GeV, indicating that the density fluctuations become the largest in collisions at this energy. With the known chemical freeze-out conditions determined from the statistical model fit to experimental data, we obtain a chemical freeze-out temperature of ∼144 MeV and baryon chemical potential of ∼385 MeV at this collision energy, which are close to the critical endpoint in the QCD phase diagram predicted by various theoretical studies. Our results thus suggest the potential usefulness of the yield ratio of light nuclei in relativistic heavy-ion collisions as a direct probe of the large density fluctuations associated with the QCD critical phenomena.

  16. Probing QCD critical fluctuations from light nuclei production in relativistic heavy-ion collisions

    Science.gov (United States)

    Sun, Kai-Jia; Chen, Lie-Wen; Ko, Che Ming; Xu, Zhangbu

    2017-11-01

    Based on the coalescence model for light nuclei production, we show that the yield ratio Op-d-t =N3HNp / Nd2 of p, d, and 3H in heavy-ion collisions is sensitive to the neutron relative density fluctuation Δn = 〈(δn) 2 〉 /〈 n 〉 2 at kinetic freeze-out. From recent experimental data in central Pb + Pb collisions at √{sNN} = 6.3 GeV, 7.6 GeV, 8.8 GeV, 12.3 GeV and 17.3 GeV measured by the NA49 Collaboration at the CERN Super Proton Synchrotron (SPS), we find a possible non-monotonic behavior of Δn as a function of the collision energy with a peak at √{sNN} = 8.8 GeV, indicating that the density fluctuations become the largest in collisions at this energy. With the known chemical freeze-out conditions determined from the statistical model fit to experimental data, we obtain a chemical freeze-out temperature of ∼ 144 MeV and baryon chemical potential of ∼ 385 MeV at this collision energy, which are close to the critical endpoint in the QCD phase diagram predicted by various theoretical studies. Our results thus suggest the potential usefulness of the yield ratio of light nuclei in relativistic heavy-ion collisions as a direct probe of the large density fluctuations associated with the QCD critical phenomena.

  17. Low-energy heavy-ion reactions: a link between nuclear structure and reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Corradi, L.; Ackermann, D.; Beghini, S.; Lin, C.J.; Montagnoli, G.; Pollarolo, G.; Scarlassara, F.; Segato, G.F.; Stefanini, A.M.; Zheng, L.F

    1999-07-26

    High precision data recently obtained in the study of multinucleon transfer and sub-barrier fusion reactions at LNL are presented. The studies of transfer channels in the systems {sup 40,48}Ca+{sup 124}Sn and {sup 64}Ni+{sup 238}U revealed important effects not identified in the past, and demonstrated the possibility of a quantitative understanding of the role played by the various degrees of freedom in the reaction mechanism. Evidence of their influence on the fusion enhancements seem to show-up in the systems {sup 40}Ca+{sup 124,116}Sn and {sup 40}Ca+{sup 90,96}Zr, but, in general, the data still escape a consistent treatment.

  18. Energetic Proton Emission and Reaction Dynamics in Heavy Ion Reactions Close to the Fermi Energy

    Science.gov (United States)

    Coniglione, R.; Sapienza, P.; Migneco, E.; Agodi, C.; Alba, R.; Bellia, G.; Colonna, M.; Del Zoppo, A.; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Piattelli, P.; Santonocito, D.; Ventura, P. G.; Colonna, N.; Bruno, M.; D'Agostino, M.; Fiandri, M. L.; Vannini, G.; Mastinu, P. F.; Gramegna, F.; Iori, I.; Fabbietti, L.; Moroni, A.; Margagliotti, G. V.; Milazzo, P. M.; Rui, R.; Tonetto, F.; Blumenfeld, Y.; Scarpaci, J. A.

    2001-11-01

    The energetic proton emission has been investigated in the 58Ni+58Ni at 30 MeV/u and 40Ar+ 51V at 44 MeV/u reactions. Information on the origin of the energetic protons and on basic ingredients of the BNV models such as the mean field interaction and the elementary nucleon-nucleon cross section was extracted. Extremely energetic protons were measured and their impact parameter dependence indicates the presence of cooperative processes.

  19. On-line Mass Spectrometric Study of Heavy-Ion Induced Reactions at Energies up to 86 MeV/amu

    CERN Multimedia

    2002-01-01

    The aim of the experiment was to measure isotopic distributions of Li, Na, K, Rb, Cs and Fr as reaction fragments in heavy ion collisions. In order to get an overall view of the new energy range for heavy ions available from the SC, different energies and projectile-target combinations had to be studied. The data taking status is now finished. |1|2C and |1|8O beams were used in bombarding |1|2C, |9|3Nb, |1|8|1Ta and |2|3|8U in order to look at target fragmentation, projectile fragmentation and evaporative residues of spallation processes. The experimental apparatus is composed of three parts: \\item a)~A target-oven-ionizer assembly where selective thermal diffusion and selective surface ionization takes place in order to obtain a chemical separation of the reaction products. \\item b)~The mass spectrometer where the different-mass fragments are selected. \\item c)~An electrostatic ion beam line through which the fragments are transported to a low-background area where the detector (an electron multiplier) is lo...

  20. $W$ boson production in ultrarelativistic heavy-ion collisions at the CERN LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00356981

    Ultrarelativistic heavy-ion collisions at the CERN Large Hadron Collider (LHC) are capable of producing a medium of deconfined quarks and gluons. This phase of nuclear matter is called a Quark-Gluon Plasma (QGP) and is believed to have been present during the first microseconds following the Big Bang. $\\Wboson$ bosons are a unique probe in a QGP since they do not carry color charge and thus do not interact with a strongly-coupled medium. Furthermore, the kinematics of $\\Wboson$ bosons are sensitive to the Bjorken momentum fraction $x$ of partons within nucleons, and therefore $\\Wboson$ bosons may also be used to constrain parton distribution functions and to detect the presence of nuclear effects. This thesis presents the measurement of $\\Wboson$ boson production in the dense nuclear environment created in $\\PbPb$ collisions at a per nucleon pair center-of-mass energy $\\sqrt{s_{\\mathrm{NN}}}=2.76\\TeV$. The data for this measurement were collected with the ATLAS detector in 2011 and correspond to a...

  1. Effective field theory approach to open heavy flavor production in heavy-ion collisions

    Science.gov (United States)

    Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan

    2017-03-01

    We develop a version of Soft Collinear Effective Theory (SCET) which includes finite quark masses, as well as Glauber gluons that describe the interaction of collinear partons with QCD matter. In the framework of this new effective field theory, labeled SCETM,G, we derive the massive splitting functions in the vacuum and the QCD medium for the processes Q → Qg, Q → gQ and g\\to Q\\overline{Q} . The numerical effects due to finite quark masses are sizable and our results are consistent with the traditional approach to parton energy loss in the soft gluon emission limit. In addition, we present a new framework for including the medium-induced full splitting functions consistent with next-to-leading order calculations in QCD for inclusive hadron production. Finally, we show numerical results for the suppression of D- and B-mesons in heavy ion collisions at √{s_{NN}}=5.02 TeV and 2.76 TeV and compare to available data from the LHC.

  2. Study of Particle Production and Nuclear Fragmentation in Relativistic Heavy-Ion Collisions in Nuclear Emulsions

    CERN Multimedia

    2002-01-01

    % EMU11 \\\\ \\\\ We propose to use nuclear emulsions for the study of nuclear collisions of $^{207}$Pb, $^{197}$Au, and any other heavy-ion beams when they are available. We have, in the past, used $^{32}$S at 200A~GeV and $^{16}$O at 200A and 60A~GeV from CERN (Experiment EMU08) and at present the analysis is going on with $^{28}$Si beam from BNL at 14.5A~GeV. It will be important to compare the previous and the present investigations with the new $^{207}$Pb beam at 60-160A~GeV. We want to measure in nuclear emulsion, on an event by event basis, shower particle multiplicity, pseudorapidity density and density fluctuations of charged particles, charge multiplicity and angular distributions of projectile fragments, production and interaction cross-sections of heavily ionizing particles emitted from the target fragmentation. Special emphasis will be placed on the analysis of events produced in the central collisions which are selected on the basis of low energy fragments emitted from the target excitation. It woul...

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

    Energy Technology Data Exchange (ETDEWEB)

    Fotiadis, Nikolaos [Los Alamos National Laboratory; Nelson, Ronald O [Los Alamos National Laboratory; Devlin, Matthew [Los Alamos National Laboratory; Cizewski, Jolie A [RUTGERS UNIV.; Krucken, Reiner [TECHNICAL UNIV OF MUNICH; Clark, R M [LBNL; Fallon, Paul [LBNL; Lee, I Yang [LBNL; Macchiavelli, Agusto O [LBNL; Becker, John A [LLNL; Younes, Walid [LLNL

    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.

  4. W Boson Production in Ultrarelativistic Heavy-Ion Collisions at the CERN LHC

    Science.gov (United States)

    Balestri, Thomas E.

    Ultrarelativistic heavy-ion collisions at the CERN Large Hadron Collider (LHC) are capable of producing a medium of deconfined quarks and gluons. This phase of nuclear matter is called a Quark-Gluon Plasma (QGP) and is believed to have been present during the first microseconds following the Big Bang. W bosons are a unique probe in a QGP since they do not carry color charge and thus do not interact with a strongly-coupled medium. Furthermore, the kinematics of W bosons are sensitive to the Bjorken momentum fraction x of partons within nucleons, and therefore W bosons may also be used to constrain parton distribution functions and to detect the presence of nuclear effects. This thesis presents the measurement of W boson production in the dense nuclear environment created in Pb+Pb collisions at a per nucleon pair center-of-mass energy squareroot of sNN = 2.76 TeV. The data for this measurement were collected with the ATLAS detector in 2011 and correspond to an integrated luminosity ƒ Ldt = 0.14 nb-1. The production of W bosons is detected using the W → munu mu decay channel, resulting in fiducial yields of 5487 +/-96 (stat.) +/-86(syst.) W+ → mu +numu events and 5262 +/-95 (stat.) +/-83(syst.) W- → mu- numu events. These results are combined with yields from the corresponding electron channel W → enue, and the combined measurement is used to construct the differential production yields and lepton charge asymmetry as a function of lepton absolute pseudorapidity. The integrated production yields and charge ratio as a function of the mean number of binary nucleon-nucleon collisions are also presented. The results are compared to predictions based on next-to-leading order QCD calculations. These observables can aid in better understanding nucleon structure within a heavy nucleus as well as provide insight into the mechanism of jet energy loss in a QGP.

  5. Exclusive production of π+π− and π0π0 pairs in photon-photon and in ultrarelativistic heavy ion collisions

    Directory of Open Access Journals (Sweden)

    Kłusek-Gawenda M.

    2012-12-01

    Full Text Available The γγ → ππ reactions are discussed. To describe those processes, we include dipion continuum, resonances, high-energy pion-pion rescatterings, ρ meson exchange and pQCD Brodsky-Lepage mechanisms. The cross section for the production of pion pairs in photon-photon collisions in peripheral heavy ion collisions is calculated with the help of Equivalent Photon Approximaption (EPA in the impact parameter space. We show predictions at √sNN TeV which could be measured e.g. by the ALICE collaboration at the LHC.

  6. A heuristic description of high-p{sub T} hadron production in heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Nemchik, Jan [Czech Technical University in Prague, FNSPE, Prague (Czech Republic); Institute of Experimental Physics SAS, Kosice (Slovakia); Pasechnik, Roman [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden); Potashnikova, Irina [Universidad Tecnica Federico Santa Maria, Departamento de Fisica, Valparaiso (Chile); Centro Cientifico-Tecnologico de Valparaiso, Valparaiso (Chile)

    2015-02-01

    Using a simplified model for in-medium dipole evolution accounting for color filtering effects we study the production of hadrons at large transverse momenta p{sub T} in heavy ion collisions. In the framework of this model, several important sources of the nuclear suppression observed recently at RHIC and LHC have been analyzed. A short production length of the leading hadron l{sub p} causes a strong onset of color transparency effects, manifesting themselves as a steep rise of the nuclear modification factor R{sub AA}(p{sub T}) at large hadron p{sub T}. The dominance of quarks with higher l{sub p} leads to a weaker suppression at RHIC than the one observed at LHC. In the RHIC kinematic region we include an additional suppression factor, steeply falling with p{sub T}, which is tightly related to the energy conservation constraints. This is irrelevant at LHC up to p{sub T}

  7. Jet and Leading Hadron Production in High-energy Heavy-ionCollisions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-Nian

    2005-11-01

    Jet tomography has become a powerful tool for the study ofproperties of dense matter in high-energy heavy-ion collisions. I willdiscuss recent progresses in the phenomenological study of jet quenching,including momentum, colliding energy and nuclear size dependence ofsingle hadron suppression, modification of dihadron correlations and thesoft hadron distribution associatedwith a quenched jet.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-03

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

  9. Forward electron production in heavy ion-atom and ion-solid collisions

    Energy Technology Data Exchange (ETDEWEB)

    Sellin, I.A.

    1984-01-01

    A sharp cusp in the velocity spectrum of electrons, ejected in ion-atom and ion-solid collisions, is observed when the ejected electron velocity vector v/sub e/ matches that of the emergent ion vector v/sub p/ in both speed and direction. In ion-atom collisions, the electrons originate from capture to low-lying, projectile-centered continuum states (ECC) for fast bare or nearly bare projectiles, and from loss to those low-lying continuum states (ELC) when loosely bound projectile electrons are available. Most investigators now agree that ECC cusps are strongly skewed toward lower velocities, and exhibit full widths half maxima roughly proportional to v/sub p/ (neglecting target-shell effects, which are sometimes strong). A close examination of recent ELC data shows that ELC cusps are instead nearly symmetric, with widths nearly independent on v/sub p/ in the velocity range 6 to 18 a.u., a result only recently predicted by theory. Convoy electron cusps produced in heavy ion-solid collisions at MeV/u energies exhibit approximately velocity-independent widths very similar to ELC cusp widths. While the shape of the convoy peaks is approximately independent of projectile Z, velocity, and of target material, it is found that the yields in polycrystalline targets exhibit a strong dependence on projectile Z and velocity. While attempts have been made to link convoy electron production to binary ECC or ELC processes, sometimes at the last layer, or alternatively to a solid-state wake-riding model, our measured dependences of cusp shape and yield on projectile charge state and energy are inconsistent with the predictions of available theories. 10 references, 8 figures, 1 table.

  10. First dedicated in-beam X-ray measurement in heavy-ion fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Berner, C. [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); RIKEN, Research Group for Superheavy Elements (Japan); Henning, W. [Argonne National Laboratory, Physics Division (United States); RIKEN, Research Group for Superheavy Elements (Japan); Muecher, D.; Gernhaeuser, R.; Hellgartner, S.; Maier, L. [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Morita, K.; Morimoto, K.; Kaji, D.; Wakabayashi, Y.; Baba, H. [RIKEN, Research Group for Superheavy Elements (Japan); Lutter, R. [Ludwig-Maximilians-Universitaet, Muenchen (Germany)

    2016-07-01

    We report on an experiment aiming at in-beam X-ray spectroscopy of heavy and superheavy elements (SHE). The goal is to establish K-X-ray spectroscopy as a sensitive tool to identify SHE produced in fusion reactions. SHE, formed after cold or hot fusion, are usually identified via the alpha-decay products, which have to be connected to well-known elements. However, various theories predict spontaneous fission as the dominant decay mode for the daughter nuclides. Additionally, half-lives of these elements are expected to increase to values impeding the identification of SHE solely by their decay. The in-beam identification of the characteristic X-rays would precisely allow to identify the charge number of the produced SHE. Experiments were performed at the RIKEN Nishina Centre for Accelerator based Science by using the gas-filled magnet separator GARIS for superheavy element detection. A high-purity, low-energy planar germanium LEGe-detector was adapted to the GARIS system at the target place for the first time in order to measure the element-characteristic, prompt X-ray emission.

  11. Fusion-fission and quasifission of superheavy systems in heavy-ion induced reactions

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-01

    Mass and energy distributions of fission-like fragments obtained in the reactions with {sup 26}Mg, {sup 36}S and {sup 58}Fe ions leading to the formation of the Z=108 composite nucleus are reported. From the analysis of TKE distributions for symmetric fragment it was found that at energies below the Coulomb barrier the bimodal fission of {sup 274}Hs, formed in the reaction {sup 26}Mg+{sup 248}Cm, is observed, while in the reaction {sup 36}S+{sup 238}U at these energies the main part of the symmetric fragments arises from the quasifission process. At energies above the Coulomb barrier the fusion-fission is a main process leading to the formation of symmetric fragment for the both reactions.

  12. Role of compound nuclei in intermediate-energy heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Moretto, L.G.; Wozniak, G.J.

    1988-05-01

    Hot compound nuclei are frequently produced in intermediate-energy reactions through a variety of processes. Their decay is shown to be an important and at times dominant source of complex fragments, high energy-gamma rays, and even pions.

  13. Prompt dipole gamma-ray emission in fusionlike heavy-ion reactions

    CERN Document Server

    Pierroutsakou, D; Di Pietro, M; Mordente, R; Ordine, A; Romoli, M; De Rosa, A; Inglima, G; La Commara, M; Martin, B; Roca, V; Sandoli, M; Trotta, M; Vardaci, E; Ming, R; Rizzo, F; Soramel, F; Stroe, L

    2003-01-01

    The sup 3 sup 2 S+ sup 1 sup 0 sup 0 Mo and sup 3 sup 6 S+ sup 9 sup 6 Mo fusionlike reactions were studied at incident energy of E sub l sub a sub b =298 MeV and 320 MeV, respectively, with the aim of probing the influence of the entrance channel charge asymmetry on the dipole gamma-ray emission. The excitation energy and spin distribution of the compound nucleus created in these reactions were identical, the only difference being associated with the unequal charge asymmetry of the two entrance channels. High-energy gamma-rays were detected in an array of 9 seven-pack BaF sub 2 clusters. Coincidence with fusionlike residues detected in four PPAC ensured the selection of central reaction events. By studying the differential gamma-ray multiplicity associated with the two reactions it was shown that the dipole strength excited in the compound nucleus increases with the entrance channel charge asymmetry. From the linearized spectra, the increase of the GDR gamma-ray intensity was found to be propor to 25% for th...

  14. Detector Calibrations for Fragmentation Reactions with Relativistic Heavy Ions at the NSCL

    Science.gov (United States)

    Garland, Heather; Stephenson, Sharon; Mosby, Michelle; MoNA Collaboration

    2014-09-01

    Prefragmentation dynamics, when neutron-rich beam nuclei interact with reaction target nuclei, have not been the subject of much experimental study. Recent data taken at the National Superconducting Cyclotron Laboratory (NSCL), in an experiment to further understand prefragmentation processes, is currently being analyzed. To experimentally determine the momentum distributions of the charged fragments made after the prefragmentation interaction between a 32Mg beam and a 9Be reaction target, the charged fragments' velocity vectors must be known. Four detectors give us position information, and two others give us energy. I worked on calibrating the four position detectors for this experiement. Prefragmentation dynamics, when neutron-rich beam nuclei interact with reaction target nuclei, have not been the subject of much experimental study. Recent data taken at the National Superconducting Cyclotron Laboratory (NSCL), in an experiment to further understand prefragmentation processes, is currently being analyzed. To experimentally determine the momentum distributions of the charged fragments made after the prefragmentation interaction between a 32Mg beam and a 9Be reaction target, the charged fragments' velocity vectors must be known. Four detectors give us position information, and two others give us energy. I worked on calibrating the four position detectors for this experiement. This work was supported by the National Science Foundation under Grant No. PHY-12-05537.

  15. Fission characteristics of Ra formed in heavy-ion induced reactions

    Indian Academy of Sciences (India)

    section of the evap- oration residue, fission cross-section, average pre-fission multiplicities of protons and α-particles for 216Ra formed in 19F+197Au reactions and results are compared with the experimental data. To calculate these quantities, the ...

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

    Directory of Open Access Journals (Sweden)

    Singh BirBikram

    2015-01-01

    Full Text Available 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.

  17. Study of resonance production as a probe of heavy-ion collisions with the ALICE detector

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Hadronic resonances provide a rich set of measurements that can be used to study the properties of ultra-relativistic heavy-ion collisions. Measurements of resonances and long-lived particles provide information about the properties of the late hadronic phase due to the presence of scattering effects that can modify resonance yields. Resonances can also be used along with long-lived hadrons to study the various mechanisms that shape particle pT spectra, including in-medium energy loss, radial flow, and recombination. Measurements of resonances in pp and p-Pb collisions serve as baselines for measurements in heavy-ion collisions, provide input for tuning QCD-inspired event generators, and aid searches for collective behavior in small systems. I will present measurements of a wide variety of hadronic resonances, including some of the most recent results presented at the Quark Matter conference. By comparing measurements of resonances with different masses, lifetimes, and quark contents in pp, p-Pb, and Pb-Pb co...

  18. Past and future detector arrays for complete event reconstruction in heavy-ion reactions

    Science.gov (United States)

    Cardella, G.; Acosta, L.; Auditore, L.; Boiano, C.; Castoldi, A.; D'Andrea, M.; De Filippo, E.; Dell'Aquila, D.; De Luca, S.; Fichera, F.; Giudice, N.; Gnoffo, B.; Grimaldi, A.; Guazzoni, C.; Lanzalone, G.; Librizzi, F.; Lombardo, I.; Maiolino, C.; Maffesanti, S.; Martorana, N. S.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Parsani, T.; Passaro, G.; Pirrone, S.; Politi, G.; Previdi, F.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Saccà, G.; Salemi, G.; Sciliberto, D.; Trifirò, A.; Trimarchi, M.; Vigilante, M.

    2017-11-01

    Complex and more and more complete detector arrays have been developed in the last two decades, or are in advanced design stage, in different laboratories. Such arrays are necessary to fully characterize nuclear reactions induced by stable and exotic beams. The need for contemporary detection of charged particles, and/or γ -rays, and/or neutrons, has been stressed in many fields of nuclear structure and reaction dynamics, with particular attention to the improvement of both high angular and energy resolution. Some examples of detection systems adapted to various energy ranges is discussed. Emphasis is given to the possible update of relatively old 4π detectors with new electronics and new detection methods.

  19. On the Role of Nuclear Surface in Heavy Ion Reaction Cross Section Formation

    CERN Document Server

    Lukyanov, V K; Zemlyanaya, E V

    2000-01-01

    The Glauber-Sitenko approach is developed for calculations of the nucleus-nucleus cross sections at intermediate energies on the basis of the analytic expression of the eikonal phase for the symmetrized Woods-Saxon potential. Calculations show that the differential elastic and total reaction cross sections occur in a good agreement with those obtained by numerical solutions of the wave equation. For the total reaction cross section, an instructive model of the phase is suggested that allows one to separate contributions from internal and peripheral regions of interaction. An important role of the surface is established in formation of the total cross section, and effects of the Coulomb field are studied, too. The nature of the continuous ambiguity of optical potentials is ascertained for interpreting experimental data.

  20. Probing nucleon-nucleon correlations in heavy-ion transfer reactions

    Directory of Open Access Journals (Sweden)

    Szilner S.

    2016-01-01

    Full Text Available The γ-particle coincident measurements, performed by coupling of the PRISMA spectrometer to the large γ arrays (CLARA and AGATA, demonstrate a strong interplay between single-particle and collective degrees of freedom that is pertinent to the reaction dynamics. By using the unique PRISMA performance in terms of both resolution and efficiency, measurements at very low bombarding energies have been performed. Via transfer of nucleon pairs, valuable information on the component responsible for particle correlations has been derived.

  1. Reaction mechanisms and their interaction time in dissipative heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    De Rosa, A.; Fioretto, E.; Inglima, G.; Romoli, M.; Sandoli, M.; Setola, R. (Dipartimento di Scienze Fisiche Universita di Napoli Federico II Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Pad. 20 Mostra d' Oltremare, Napoli, (Italy)); Cardella, G.; Papa, M.; Pappalardo, G.; Rizzo, F.; Wang, Q. (Dipartimento di Fisica Universita di Catania Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Corso Italia, 57 Catania, (Italy)); Napoli, D.R.; Scarlassara, F.; Segato, G.F.; Signorini, C.; Stefanini, A.M. (Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, Padova, (Italy))

    1990-05-01

    Angular distributions of fragments emitted in the reaction {sup 19}F+{sup 63}Cu measured in the range {theta}{sub lab}=10{degree} to 120{degree} at incident energy between 100 to 108 MeV (lab) have been analyzed according to available models for deep inelastic collisions with the aim to evidence different mechanisms contributing to such reactions. The analysis was performed in the framework of Strutinsky model taking into account both the development of Kun and of Abul-Magd and Simbel. To determine the interaction times, previously published excitation functions were also analyzed in the framework of Kun's model of cross section statistical fluctuations and near-side and far-side scattering were taken into account separately. It was pointed out that the rotational energy dissipation occurs in a limited angular range around the grazing angle. The presence of two distinct reaction mechanisms, each of them characterized by an interaction time, was also evidenced by comparing the energy averaged angular distributions to the Abul-Magd and Simbel model for dissipative collisions.

  2. Development in the field of heavy ion physics at the Flerov Laboratory of Nuclear Reactions

    CERN Document Server

    Itkis, M G; Popeko, A G

    2001-01-01

    A unique research base with modern set-ups (kinematic separators, 4 pi-spectrometers of charged particles, detectors of neutron and gamma-quanta) has been created at the FLNR on the basis of the U-400 and U-400M isochronous cyclotrons. A program on the synthesis of superheavy elements in the region of predicted spherical shells with Z approx = 114 and N approx = 184 has been launched. First experiments aimed at the synthesis of the nuclei with Z = 112, 114 and 116 have been carried out using sup 4 sup 8 Ca+ sup 2 sup 3 sup 8 U, sup 4 sup 8 Ca+ sup 2 sup 4 sup 2 sup , sup 2 sup 4 sup 4 Pu and sup 4 sup 8 Ca+ sup 2 sup 4 sup 8 Cm reactions. New results on the properties of Rf and Sg have been obtained. New evidence of the shell influence on the nuclear fission dynamics has been obtained. A number of experiments devoted to the study of reaction mechanism in nucleus-nucleus collisions were carried out. Manifestations of the sup 6 He-nucleus structure in elastic scattering and transfer reactions between sup 6 He a...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Heavy-ion transfer reactions at large internuclear distances using the PRISMA magnetic spectrometer

    Directory of Open Access Journals (Sweden)

    Montanari D. J.

    2013-12-01

    Full Text Available We measured excitation functions for the main transfer channels in the 116Sn+60Ni reaction at different bombarding energies from above to well below the Coulomb barrier. The experiment has been performed in inverse kinematics, detecting the lighter (target-like ions with the magnetic spectrometer PRISMA at very forward angles. Good mass, nuclear charge and kinetic energy resolutions have been achieved. The comparison between the data and microscopic calculations for the present case and for the previously measured 96Zr+40Ca system, namely superfluid and near closed shells nuclei, should significantly improve our understanding of nucleon-nucleon correlation properties in multinucleon transfer processes.

  5. Excitation of Nucleon Resonances in Heavy-Ion Charge-Exchange Reactions

    Science.gov (United States)

    Benlliure, J.; Vargas, J.; Alvarez-Pol, H.; Aumann, T.; Atkinson, J.; Ayyad, Y.; Beceiro, S.; Borezky, K.; Chatillon, A.; Cortina, D.; Diaz, P.; Estrade, A.; Geissel, H.; Lenske, H.; Litvinov, Y.; Mostazo, M.; Paradela, C.; Pietri, S.; Prochazka, A.; Taieb, J.; Takechi, M.; Vidaña, I.; Weick, H.; Winfield, J.

    Isobaric charge-exchange reactions induced by different tin isotopes have been investigated at GSI. The high-resolving power of the FRS spectrometer made it possible to separate elastic and inelastic components in the missing-energy spectra of the ejectiles. The inelastic component was associated to the in-medium excitation of nucleon resonances such as the Delta and Roper resonances. These data are expected to contribute to better understand the role of subnuclear degrees of freedom in three body forces or the missing strength in Gamow-Teller transitions but also to investigate the abundance of protons and neutrons at the nuclear periphery.

  6. Impact of spin-orbit density dependent potential in heavy ion reactions forming Se nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Rajni; Sharma, Ishita; Sharma, Manoj K. [Thapar University, School of Physics and Materials Science, Patiala (India); Jain, Deepika [Mata Gujri College, Department of Physics, Fatehgarh Sahib (India)

    2017-10-15

    The Skyrme energy density formalism is employed to explore the effect of spin-orbit interaction potential by considering a two nucleon transfer process via various entrance channels such as {sup 23}Na + {sup 49}V, {sup 25}Mg + {sup 47}Ti, {sup 27}Al + {sup 45}Sc, {sup 29}Si + {sup 43}Ca and {sup 31}P + {sup 41}K, all forming the same compound system {sup 72}Se*, using both spherical as well as quadrupole deformed (β{sub 2}) nuclei. For spherical nuclei, the spin-orbit density part V{sub J} of nuclear potential remains unaffected with the transfer of two nucleons from the target to the projectile, however, show notable variation in magnitude after inclusion of deformation effects. Likewise, deformations play an important role in the spin-orbit density independent part V{sub P}, as the fusion pocket start appears, which otherwise diminish for the spherical nuclei. Further, the effect of an increase in the N/Z ratio of Se is explored on V{sub J} as well as V{sub P} and results are compared with transfer channels. In addition to this, the role of double spin-orbit parameters (W{sub 0} and W{sub 0}{sup '}) with relative contribution of the isoscalar and isovector parts of spin-orbit strength is explored in view of SkI2, SkI3 and SkI4 Skyrme forces. Beside this, the decay path of {sup 72}Se* nucleus formed in {sup 27}Al + {sup 45}Sc reaction is investigated within the framework of dynamical cluster decay model (DCM), where the nuclear proximity potential is obtained by both Skyrme energy density formalism (SEDF) and proximity pocket formula. The fusion hindrance in the {sup 27}Al + {sup 45}Sc reaction is also addressed via the barrier lowering parameter ΔV{sub B}. Finally, the contribution of spin-orbit density dependent interaction potential is estimated for the {sup 27}Al + {sup 45}Sc reaction using single (W{sub 0} or W{sub 0}{sup '}) and double spin-orbit parameters (W{sub 0} and W{sub 0}{sup '}). (orig.)

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

    Directory of Open Access Journals (Sweden)

    Vo-Phuoc K.

    2016-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  9. Statistical and dynamical modeling of heavy-ion fusion-fission reactions

    Science.gov (United States)

    Eslamizadeh, H.; Razazzadeh, H.

    2018-02-01

    A modified statistical model and a four dimensional dynamical model based on Langevin equations have been used to simulate the fission process of the excited compound nuclei 207At and 216Ra produced in the fusion 19F + 188Os and 19F + 197Au reactions. The evaporation residue cross section, the fission cross section, the pre-scission neutron, proton and alpha multiplicities and the anisotropy of fission fragments angular distribution have been calculated for the excited compound nuclei 207At and 216Ra. In the modified statistical model the effects of spin K about the symmetry axis and temperature have been considered in calculations of the fission widths and the potential energy surfaces. It was shown that the modified statistical model can reproduce the above mentioned experimental data by using appropriate values of the temperature coefficient of the effective potential equal to λ = 0.0180 ± 0.0055, 0.0080 ± 0.0030 MeV-2 and the scaling factor of the fission barrier height equal to rs = 1.0015 ± 0.0025, 1.0040 ± 0.0020 for the compound nuclei 207At and 216Ra, respectively. Three collective shape coordinates plus the projection of total spin of the compound nucleus on the symmetry axis, K, were considered in the four dimensional dynamical model. In the dynamical calculations, dissipation was generated through the chaos weighted wall and window friction formula. Comparison of the theoretical results with the experimental data showed that two models make it possible to reproduce satisfactorily the above mentioned experimental data for the excited compound nuclei 207At and 216Ra.

  10. A Monte Carlo approach to study neutron and fragment emission in heavy-ion reactions

    CERN Document Server

    Garzelli, M V; Battistoni, G; Cerutti, F; Ferrari, A; Gadioli, E; Ottolenghi, A; Pinsky, L S; Ranft, J; Sala, P R

    2007-01-01

    Quantum Molecular Dynamics models (QMD) are Monte Carlo approaches targeted at the description of nucleon-ion and ion-ion collisions. We have developed a QMD code, which has been used for the simulation of the fast stage of ion-ion collisions, considering a wide range of system masses and system mass asymmetries. The slow stage of the collisions has been described by statistical methods. The combination of both stages leads to final distributions of particles and fragments, which have been compared to experimental data available in literature. A few results of these comparisons, concerning neutron double-differential production cross-sections for C, Ne and Ar ions impinging on C, Cu and Pb targets at 290 - 400 MeV/A bombarding energies and fragment isotopic distributions from Xe + Al at 790 MeV/A, are shown in this paper.

  11. Preequilibrium particle emissions and in-medium effects on the pion production in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhao-Qing [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

    2017-02-15

    Within the framework of the Lanzhou quantum molecular dynamics (LQMD) transport model, pion dynamics in heavy-ion collisions near threshold energies and the emission of preequilibrium particles (nucleons and light complex fragments) have been investigated. A density, momentum and isospin-dependent pion-nucleon potential based on the Δ-hole model is implemented in the transport approach, which slightly leads to the increase of the π{sup -}/π{sup +} ratio, but reduces the total pion yields. It is found that a bump structure of the π{sup -}/π{sup +} ratio in the kinetic energy spectra appears at the pion energy close to the Δ(1232) resonance region. The yield ratios of neutrons to protons from the squeeze-out particles perpendicular to the reaction plane are sensitive to the stiffness of nuclear symmetry energy, in particular at the high-momentum (kinetic energy) tails. (orig.)

  12. Particle and jet production in heavy-ion collisions with the ATLAS detector at LHC

    CERN Document Server

    Debbe, R; The ATLAS collaboration

    2012-01-01

    Particles and jets produced in heavy ion collisions are used to understand the hot, dense matter created in these interactions. Because of its wide angular coverage, highly hermetic design, and high pT capabilities, the ATLAS detector at the LHC provides an ideal environment in which to study these collisions. ATLAS has measured a wide variety of observables characterizing the bulk medium properties as well as the response of the medium to high-pT probes. Measurements have been made of charged particle multiplicity, elliptic flow, and higher-order particle flow, which allow characterization of global properties of the system. For the first time at this energy, elliptic and higher order flow has been measured over 5 units of pseudorapidity, from -2.5 to 2.5, and over a broad range in transverse momentum, 0.5-20 GeV. The higher-order particle flow studies are providing new insight into the role of initial state geometric fluctuations in these observables, with results obtained for the first through the sixth Fo...

  13. ϒ Production in Heavy-Ion Collisions from the STAR Experiment

    Science.gov (United States)

    Ye, Zaochen; STAR Collaboration

    2017-08-01

    In these proceedings, we present recent results of ϒ measurements in heavy-ion collisions from the STAR experiment at RHIC. Nuclear modification factors (RAA) for ϒ (1 S) and ϒ (1 S + 2 S + 3 S) in U+U collisions at √{sNN } = 193 GeV are measured through the di-electron channel and compared to those in Au+Au collisions at √{sNN } = 200 GeV and Pb+Pb collisions at √{sNN } = 2.76 TeV. The ratio between the ϒ (2 S + 3 S) and ϒ (1 S) yields in Au+Au collisions at √{sNN } = 200 GeV is measured in the di-muon channel and compared to those in p+p collisions and in Pb+Pb collisions at √{sNN } = 2.76 TeV. Prospects for future ϒ measurements with the STAR experiment are also discussed.

  14. Development of a laser ion source for production of high-intensity heavy-ion beams

    Science.gov (United States)

    Kashiwagi, H.; Yamada, K.; Kurashima, S.

    2017-09-01

    A laser ion source has been developed as a high-intensity source for the ion implanter and the single pulsed beam of the azimuthally varying field cyclotron at TIARA. Highly charged beams of C5+ and C6+ ions and low-charged beams of heavy ions such as C, Al, Ti, Cu, Au, and Pt are required for the single-pulse acceleration in the cyclotron and for the ion implanter, respectively. In the vacuum chamber of the ion source, a target holder on a three-dimensional linear-motion stage provides a fresh surface for each laser shot. A large-sized target with a maximum size of 300 mm × 135 mm is mounted on the holder for long-term operation. The ion current (ion charge flux) in the laser-produced plasma is measured by a Faraday cup and time-of-flight spectra of each charge state are measured using a 90° cylindrical electrostatic analyzer just behind the Faraday cup. Carbon-plasma-generation experiments indicate that the source produces intense high- and low-charged pulsed ion beams. At a laser energy of 483 mJ (2.3 × 1013 W/cm2), average C6+ current of 13 mA and average C5+ current of 23 mA were obtained over the required time duration for single-pulse acceleration in the cyclotron (49 ns for C6+ and 80 ns for C5+). Furthermore, at 45 mJ (2.1 × 1012 W/cm2), an average C2+ current of 1.6 mA over 0.88 μs is obtained.

  15. Mini-jet production in proton-antiproton interactions and particle production in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Wang Haiqiao

    1997-04-01

    The thesis is based on the data analysis and detector development of the EMU01/CERN, E863/BNL and UA1/CERN experiments. Particle fluctuations are studied with the scaled factorial moments in the fragmentation region of oxygen induced emulsion interactions from 3.7 to 200 A GeV. The intermittency indices show an energy independent behaviour in the target and projectile regions of pseudorapidity. In order to study the origin of the fluctuations, jet-like and ring-like substructures of particles produced in the azimuthal plane are investigated for the S - Au, S - Em and O - Em interactions at 200 A GeV. The study shows that the two particle azimuthal correlations can be well understood if Bose-Einstein correlations and {gamma}-conversion are included. A nuclear rescattering model, which incorporates the FRITIOF model, has been developed. The model can well describe multiplicity distributions of slow recoiling protons, evaporation particles and their correlations with particles produced in high energy heavy ion collisions. In order to improve the measurements of Pb induced collisions, an automatic system based on the CCD technique and image processing was developed. This system has been used to measure densities of the particles produced. Mini-jet production is studied using the UA1 1987 minimum bias data sample for p (anti) interaction at s{sup 1/2} 0 630 GeV. The study shows that the transverse energy distribution of mini-jets is in good agreement with the QCD prediction. The angular distributions of two leading jets show the behaviour of elastic scattering of partons with gluon exchange. 86 refs.

  16. Beam losses in heavy ion drivers

    CERN Document Server

    Mustafin, E R; Hofmann, I; Spiller, P J

    2002-01-01

    While beam loss issues have hardly been considered in detail for heavy ion fusion scenarios, recent heavy ion machine developments in different labs (European Organization for Nuclear Research (CERN), Gesellschaft fur Schwerionenforschung (GSI), Institute for Theoretical and Experimental Physics (ITEP), Relativistic Heavy-Ion Collider (RHIC)) have shown the great importance of beam current limitations due to ion losses. Two aspects of beam losses in heavy ion accelerators are theoretically considered: (1) secondary neutron production due to lost ions, and (2) vacuum pressure instability due to charge exchange losses. Calculations are compared and found to be in good agreement with measured data. The application to a Heavy-Ion Driven Inertial Fusion (HIDIF) scenario is discussed. 12 Refs.

  17. Electron-positron production in ultra-peripheral heavy-ion collisions with the STAR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Vladimir Borisovitch [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    This thesis presents a measurement of the cross-section of the purely electromagnetic production of e+e- pairs accompanied by mutual nuclear Coulomb excitation AuAu → Au*Au* + e+e-, in ultra-peripheral gold-gold collisions at RHIC at the center-of-mass collision energy of √SNN = 200 GeV per nucleon. These reactions were selected by detecting neutron emission by the excited gold ions in the Zero Degree Calorimeters. The charged tracks in the e+e- events were reconstructed with the STAR Time Projection Chamber. The detector acceptance limits the kinematical range of the observed e+e- pairs; therefore the measured cross-section is extrapolated to 4π with the use of Monte Carlo simulations. We have developed a Monte Carlo simulation for ultra-peripheral e+e- production at RHIC based on the Equivalent Photon Approximation, the lowest-order QED e+e- production cross-section by two real photons and the assumption that the mutual nuclear excitations and the e+e- production are independent (EPA model). We compare our experimental results to two models: the EPA model and a model based on full QED calculation of the e+e- production, taking the photon virtuality into account. The measured differential cross-section dσ/dMinv (Minv - e+e- invariant mass) agrees well with both theoretical models. The measured differential cross-section dσ/dp $tot\\atop{\\perp}$ (p$tot\\atop{\\perp}$- e+e- total transverse momentum) favors the full QED calculation over the EPA model.

  18. Heavy-ion-induced production and preseparation of short-livedisotopes for chemistry experiments

    Energy Technology Data Exchange (ETDEWEB)

    Dullmann, Christoph E.; Folden III, Charles M.; Gregorich, Kenneth E.; Hoffman, Darleane C.; Leitner, Daniela; Pang, Gregory K.; Sudowe, Ralf; Zielinski, Peter M.; Nitsche, Heino

    2005-02-24

    Physical separation of short-lived isotopes produced inheavy-ion-induced fusion reactions is a powerful and well know method andoften applied in investigations of the heaviest elements, called thetransactinides (Z>=104). By extracting these isotopes from a recoilseparator, they can be made available for transport to setups locatedoutside the heavily shielded irradiation position such as chemistrysetups. This physical preseparation technique overcomes many limitationscurrently faced in the chemical investigation of transactinides. Here wedescribe the basic principle using relatively short-lived isotopes of thelighter group 4 elements zirconium (Zr) and hafnium (Hf) that are used asanalogs of the lightest transactinide element, rutherfordium (Rf, element104). The Zr and Hf isotopes were produced at the LBNL 88-Inch Cyclotronusing a cocktail of 18O and 50Ti beams and the appropriate targets.Subsequently, the isotopes were physically separated in the BerkeleyGas-filled Separator (BGS) and guided to a Recoil Transfer Chamber (RTC)to transfer them to chemistry setups. The magnetic rigidities of thereaction products in low-pressure helium gas were measured and theiridentities determined with gamma-pectroscopy. Using preseparated isotopeshas the advantages of low background and beam plasma free environment forchemistry experiments. The new possibilities that open up for chemicalinvestigations of transactinide elements are descr ibed. The method canreadily be applied to homologous elements within other groups in theperiodic table.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-20

    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.

  20. Studies of heavy ion reactions and transuranic nuclei. Progress report, August 1, 1979-July 31, 1980. [Univ. of Rochester, New York, 8/1/79-7/31/80

    Energy Technology Data Exchange (ETDEWEB)

    Huizenga, J.R.

    1980-07-01

    The study of heavy-ion reaction mechanisms at the SuperHILAC and LAMPF is reported. Preprints of five articles and manuscripts of four recent conference papers are given, along with complete citations of publications and a list of personnel. Significant work was performed in the following areas: the bombarding energy dependence of the /sup 209/Bi + /sup 136/Xe reaction; the fragment yields for specific Z and A for projectile-like fragments produced in the reaction of 8.3-MeV/u /sup 56/Fe ions with targets of /sup 56/Fe, /sup 165/Ho, /sup 209/Bi, and /sup 238/U; and time distributions of fragments from delayed fission after muon capture for muonic /sup 235/U, /sup 238/U, /sup 237/Np, /sup 239/Pu, and /sup 242/Pu. (RWR)

  1. Heavy-ion Physics (ATLAS)

    CERN Document Server

    Przybycien, Mariusz; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment at the Large Hadron Collider has undertaken a broad physics program to probe and characterize the hot nuclear matter created in relativistic heavy-ion collisions. This talk presents recent results on production of electroweak bosons and quarkonium, charged particles and jets, bulk particle collectivity and electromagnetic processes in ultra-peripheral collisions, from Pb+Pb and p+Pb collisions.

  2. Low charge state heavy ion production with sub-nanosecond laser.

    Science.gov (United States)

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

    2016-02-01

    We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

  3. Strong Enhancement of Extremely Energetic Proton Production in Central Heavy Ion Collisions at Intermediate Energy

    Science.gov (United States)

    Sapienza, P.; Coniglione, R.; Colonna, M.; Migneco, E.; Agodi, C.; Alba, R.; Bellia, G.; del Zoppo, A.; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Piattelli, P.; Santonocito, D.; Ventura, P. G.; Blumenfeld, Y.; Bruno, M.; Colonna, N.; D'Agostino, M.; Fabbietti, L.; Fiandri, M. L.; Gramegna, F.; Iori, I.; Margagliotti, G. V.; Mastinu, P. F.; Milazzo, P. M.; Moroni, A.; Rui, R.; Scarpaci, J. A.; Vannini, G.

    2001-08-01

    The energetic proton emission has been investigated as a function of the reaction centrality for the system 58Ni+58Ni at 30A MeV. Extremely energetic protons (ENNp>=130 MeV) were measured and their multiplicity is found to increase almost quadratically with the number of participant nucleons, thus indicating the onset of a mechanism beyond one- and two-body dynamics.

  4. Production of pi(0) and eta mesons in carbon-induced relativistic heavy-ion collisions

    NARCIS (Netherlands)

    Averbeck, R; Doppenschmidt, A; Appenheimer, M; Charbonnier, Y; Diaz, J; Hejny, [No Value; Hlavac, S; Holzmann, R; Kugler, A; Lefevre, F; Lohner, H; Marin, A; Metag, [No Value; Niebur, W; Ostendorf, RW; Pleskac, R; Schubert, A; Schutz, Y; Siemssen, H; Simon, RS; Stratmann, R; Stroher, H; Tlusty, P; Vogt, PH; Wagner, [No Value; Weiss, J; Wilschut, HW; Wissmann, F; Wolf, M

    The production of pi(0) and eta mesons has been investigated in the system C-12+C-12 at 0.8A GeV, 1.0A GeV, and 2.0A GeV using the TAPS photon detector. The production cross sections and transverse-momentum distributions measured around midrapidity extend the existing systematics of neutral-meson

  5. Intriguing aspects in baryon production at relativistic heavy-ion collider

    Indian Academy of Sciences (India)

    Abstract. We review experimental results on baryon production at mid-rapidity in nucleus–nucleus collisions at RHIC. Outstanding physics issues include the mechanism for baryon–anti-baryon pro- duction from thermally equilibrated partons, the dynamics of baryon number transport and the evolu- tion dynamics of baryons ...

  6. Heavy flavor production and interactions in relativistic heavy-ion collisions in CMS experiment

    CERN Document Server

    Xie, Wei

    2017-02-07

    This paper presents the CMS measurements of quarkonia and open heavy flavor production in \\pp, \\pPb, and \\PbPb collisions at \\sqrtsnn = 2.76 and 5.02 TeV. A brief outlook of the near-future CMS heavy flavor physics analyses is provided at the end.

  7. Electroweak boson production in heavy ion collisions with the ATLAS detector

    CERN Document Server

    Janus, Piotr Andrzej; The ATLAS collaboration

    2017-01-01

    Electroweak bosons produced in p+Pb and Pb+Pb collisions are excellent tools to probe a variety of initial state effects on hard processes involving nuclei. These effects include the nuclear modification of the partonic momentum structure and the energy loss of the incoming partons participating in a hard scattering. These probes are also important for serving as a standard candle against which to calibrate centrality in Pb+Pb collisions, thus putting measurements of jet suppression in these collisions into a proper context. In this talk, we present two new results from the ATLAS detector at the LHC: (1) Prompt photon production in the recently collected high-statistics 8.16 TeV p+Pb collision data. Photon yields are reported over a broad kinematic range, 25 < pT^gamma < 500 GeV and |eta^lab| < 2.37, and the production rates are compared to an extrapolated pp reference based on existing 8 TeV collision data. (2) High-statistics measurement of W boson production, new at this collision energy, both in ...

  8. Measurements of $\\phi$ meson production in relativistic heavy-ion collisions at RHIC

    CERN Document Server

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Baumgart, S; Beavis, D R; Bellwied, R; Benedosso, F; Betts, R R; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Biritz, B; Bland, L C; Blyth, S L; Bombara, M; Bonner, B E; Botje, M; Bouchet, J; Braidot, E; Brandin, A V; Bruna, E; Bültmann, S; Burton, T P; Bystersky, M; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Callner, J; Catu, O; Cebra, D; Cendejas, R; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, S U; Clarke, R F; Codrington, M J M; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Daugherity, M; De Silva, C; Dedovich, T G; De Phillips, M; Derevshchikov, A A; Derradide Souza, R; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Du, F; Dunlop, J C; Dutta-Majumdar, M R; Edwards, W R; Efimov, L G; Elhalhuli, E; Elnimr, M; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Eun, L; Fachini, P; Fatemi, R; Fedorisin, J; Feng, A; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Gagliardi, C A; Gaillard, L; Gangadharan, D R; Ganti, M S; García-Solis, E; Ghazikhanian, V; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O; Grosnick, D; Grube, B; Guertin, S M; Guimaraes, K S F F; Sen-Gupta, A; Gupta, N; Guryn, W; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Heppelmann, S; Hippolyte, B; Hirsch, A; Hoffman, A M; Hoffmann, G W; Hofman, D J; Hollis, R S; Huang, H Z; Humanic, T J; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jin, F; Jones, P G; Joseph, J; Judd, E G; Kabana, S; Kajimoto, K; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Kettler, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kopytine, M; Kotchenda, L; Kouchpil, V; Kravtsov, P; Kravtsov, V I; Krüger, K; Krus, M; Kuhn, C; Kumar, L; Kurnadi, P; Lamont, M A C; Landgraf, J M; La Pointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, C H; Le Vine, M J; Li, C; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Mahapatra, D P; Majka, R; Mall, M I; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Matis, H S; Matulenko, Yu A; McShane, T S; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mischke, A; Mitchell, J; Mohanty, B; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Nepali, C; Netrakanti, P K; Ng, M J; Nogach, L V; Nurushev, S B; Odyniec, G J; Ogawa, A; Okada, H; Okorokov, V; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Yu A; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Phatak, S C; Planinic, M; Pluta, J; Poljak, N; Poskanzer, A M; Potukuchi, B V K S; Prindle, D; Pruneau, C; Pruthi, N K; Putschke, J; Raniwala, R; Raniwala, S; Ray, R L; Reed, R; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Rykov, V; Sahoo, R; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Shi, X H; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Snellings, R; Sørensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Staszak, D; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Timoshenko, S; Tlusty; Tokarev, M; Trainor, T A; Tram, V N; Trattner, A L; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; Van Leeuwen, M; Van der Molen, A M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasilevski, I M; Vasilev, A N; Videbaek, F; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, Q; Wang, X; Wang, X L; Wang, Y; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, Y; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yepes, P; Yoo, I K; Yue, Q; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, H; Zhang, S; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zhou, J; Zoulkarneev, R; Zoulkarneeva, Y; Zuo, J X

    2008-01-01

    We present results for the measurement of $\\phi$ meson production via its charged kaon decay channel $\\phi \\to K^+K^-$ in Au+Au collisions at $\\sqrt{s_{_{NN}}}=62.4$, 130, 200 GeV, and in p+p and d+Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV from the STAR experiment at RHIC. The mid-rapidity ($|y|<0.5$) $\\phi$ meson spectra in central Au+Au collisions are found to be well described by a single exponential distribution. On the other hand, the spectra from p+p, d+Au and peripheral Au+Au collisions show power-law tails at intermediate and high transverse momenta ($p_{T}$) and are described better by Levy distributions. The constant $\\phi/K^-$ yield ratio vs. beam species, collision centrality and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for $\\phi$ production at RHIC. The $\\Omega/\\phi$ yield ratio as a function of $p_{T}$ is consistent with a model based on the recombination of thermal $s$ quarks up to $p_{T}\\sim 4$ GeV/c, but disagree...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

  10. Cross section for production of low-energy electron-positron pairs by relativistic heavy ions

    Science.gov (United States)

    Eby, P. B.

    1991-01-01

    Starting with the lowest-order unscreened QED matrix element for electron-positron pair production by heavy charged particles, the paper calculates the cross section for this process differential in all independent variables and valid for all pair energies small compared to the incident particle energy. Integration over the possible emission angles of one of the pair members gives an expression that is valid for low-energy pairs that can be compared with previous work based on the Weizsaecker-Williams method. Integration over the possible angles of the other pair member then yields an expression identical to one derived by Racah. The high energy-transfer limit of the expression for the cross section integrated over electron and positron angles is found to be identical to that of Kelner in the unscreened case.

  11. Exclusive DD¯${m{Dar D}}$ meson pair production in peripheral ultrarelativistic heavy ion collisions

    Directory of Open Access Journals (Sweden)

    Luszczak Marta

    2012-12-01

    Full Text Available The cross sections for exclusive D+D- and DD¯${D^0ar D^0}$ meson pair production in peripheral nucleus - nucleus collisions are calculated and several differential distributions are presented. The calculation of the elementary γγ → DD¯${m{Dar D}}$ cross section is done within the heavy-quark approximation and in the Brodsky- Lapage formalism with distribution amplitudes describing recent CLEO data on leptonic D+ decay. Absorption effects are discussed and quantified. The cross sections of a few nb are predicted for RHIC and of a few hundreds of nb for LHC with details depending on the approximation made in calculating elementary γγ → DD¯${m{Dar D}}$ cross sections.

  12. Multifractal characteristics of multiparticle production in heavy-ion collisions at SPS energies

    Science.gov (United States)

    Khan, Shaista; Ahmad, Shakeel

    Entropy, dimensions and other multifractal characteristics of multiplicity distributions of relativistic charged hadrons produced in ion-ion collisions at SPS energies are investigated. The analysis of the experimental data is carried out in terms of phase space bin-size dependence of multiplicity distributions following the Takagi’s approach. Yet another method is also followed to study the multifractality which, is not related to the bin-width and (or) the detector resolution, rather involves multiplicity distribution of charged particles in full phase space in terms of information entropy and its generalization, Rényi’s order-q information entropy. The findings reveal the presence of multifractal structure — a remarkable property of the fluctuations. Nearly constant values of multifractal specific heat “c” estimated by the two different methods of analysis followed indicate that the parameter “c” may be used as a universal characteristic of the particle production in high energy collisions. The results obtained from the analysis of the experimental data agree well with the predictions of Monte Carlo model AMPT.

  13. Dielectron production in heavy ion collisions at 158 GeV/c per nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Busch, Oliver

    2007-12-03

    In this thesis we study dilepton production in Pb-Au collisions at 158 GeV/c per nucleon measured with the Cherenkov Ring Electron Spectrometer (CERES) at the Super Proton Synchrotron (SPS) at CERN. The data taken in the year 2000 represent the first CERES runs with the fully operational Time Projection Chamber (TPC). The upgrade of the spectrometer with this powerful tracking device allows to realize a new approach for particle identification with the Ring Imaging Cherenkov (RICH) detector. We present the development and optimization of track-based ring reconstruction methods which allow to identify both electrons and pions at momenta above the Cherenkov threshold. To compare the performance of different methods, the reconstruction is applied to the CERES data. This allows to determine experimentally, for the first time, the CERES RICH efficiency and background rejection power. The new particle identification is used for low-mass dielectron reconstruction. Significant improvements in the simulation of the detector allow to evaluate the electron pair reconstruction efficiency with high accuracy and to study the origin of electron pair combinatorial background. The results motivate an extension of the TPC tracking, to improve the reconstruction efficiency for low-momentum tracks, and allow better identification of electron background. Our results corroborate the previous CERES findings of an enhancement of electron pairs over the hadronic cocktail in the invariant mass region m{sub inv} >or similar 0.2 GeV/c{sup 2}. Comparison to previous analyses of the same data shows good consistency and supports our estimate of the systematic uncertainties of the electron analysis. Our results supply evidence for a modification of the spectral function of the {rho} meson in the hot and dense medium and strongly support baryon-induced interactions at the origin of the effect. Furthermore, we present in this work the first direct measurements of transition radiation (TR) spectra

  14. Heavy-ion collisions described by a new QMD code interfaced to FLUKA: model validation by comparisons with experimental data concerning neutron and charged fragment production

    CERN Document Server

    Garzelli, M V; Battistoni, G.; Cerutti, F.; Fasso, A.; Ferrari, A.; Gadioli, E.; Ottolenghi, A.; Pinsky, Lawrence S.; Ranft, J.; Sala, P.R.

    2006-01-01

    A new code, based on the Quantum Molecular Dynamics theoretical approach, has been developed and interfaced to the FLUKA evaporation/fission/Fermi break-up module. At present, this code is undergoing a series of validation tests. In this paper its predictions are compared to measured charged fragment yields and double differential neutron spectra in thin target heavy-ion reactions, at bombarding energies of about 100 MeV/A. The comparisons with the predictions of a modified version of RQMD 2.4 originally developed in Frankfurt, already available in the FLUKA code, are presented and potential improvements are briefly sketched.

  15. Particle Correlations with Heavy Ions at LHC Energies

    CERN Document Server

    Erazmus, B; Roy, C; Werner, K; Lednicky, R; Lyuboshitz, V L; Mikhailov, K; Stavinsky, A V; Pluta, J; Sinyukov, Yu M

    1998-01-01

    The ALICE detector will offer very good conditions to study the space-time characteristics of particle production in heavy-ion collisions at LHC from measurements of the correlation function of identical and non-identical particles at small relative velocities. The correlations - induced by Coulomb and nuclear final-state interactions - of non-identical particles appear to be directly sensitive to the space-time asymmetries of particle production allowing, in particular, a measurement of the mean relative delays in particle emission at time scales as small as few fm/c. The problem of Coulomb interaction of the correlated particles is particularly important in the case of the large effective volumes formed in ultra-relativistic heavy-ion reactions.

  16. Extracting integrated and differential cross sections in low-energy heavy-ion reactions from backscattering measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sargsyan, V.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Yerevan State University, Yerevan (Armenia); Adamian, G.G.; Antonenko, N.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Diaz-Torres, A. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas, Villazzano (Italy); Gomes, P.R.S. [Universidade Federal Fluminense, Instituto de Fisica, Niteroi (Brazil); Lenske, H. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, Giessen (Germany)

    2014-11-15

    We suggest new methods to extract elastic (quasi-elastic) scattering angular distribution and reaction (capture) cross sections from the experimental elastic (quasi-elastic) backscattering excitation function taken at a single angle. A novel Coulomb scattering relation between angular momentum and centrifugal energy is used. The methodology is developed for addressing complementary reaction observables, improving the description of elastic differential cross section. (orig.)

  17. Light Particle Emission Mechanisms in Heavy-Ion Reactions at 5-20 MeV/u

    Directory of Open Access Journals (Sweden)

    Fotina O.V.

    2010-03-01

    Full Text Available Light Charged Particle emission mechanisms were studied for different mass entrance channel nuclear reactions. The 300, 400, 500 MeV 64Ni + 68Zn and 130, 250 MeV 16O + 116Sn reactions were measured at the Legnaro National Laboratory using the beams from the TANDEM-ALPI acceleration system. Light Charged Particles were measured in coincidence with Evaporation Residues and their spectra were analyzed using the global moving source fit technique. The characterization of different emission sources (evaporative, pre-equilibrium, break-up is discussed. The behavior of pre-equilibrium emission as a function of projectile energy, excitation energy and mass-asymmetry in the entrance channel was studied, evaluating the energy, mass and charge lost by the composite systems and using Griffin exciton model for the pre-equilibrium neutron emission. The present results are compared with the systematics of the asymmetric mass entrance channel reactions. The present work shows that also at the onset the pre-equilibrium emission depends not only on the projectile velocity but also on the reaction entrance channel mass-asymmetry. The first attempt of the particle spectra analysis using the Griffin exciton model is demonstrated for the case of proton emission in the 130 MeV 16O + 116Sn reaction.

  18. Heavy-ion double charge exchange reactions: A tool toward 0 νββ nuclear matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Cappuzzello, F.; Bondi, M. [Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); INFN, Laboratori Nazionali del Sud, Catania (Italy); Cavallaro, M.; Agodi, C.; Carbone, D.; Cunsolo, A. [INFN, Laboratori Nazionali del Sud, Catania (Italy); Foti, A. [Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); INFN, Sezione di Catania, Catania (Italy)

    2015-11-15

    The knowledge of the nuclear matrix elements for the neutrinoless double beta decay is fundamental for neutrino physics. In this paper, an innovative technique to extract information on the nuclear matrix elements by measuring the cross section of a double charge exchange nuclear reaction is proposed. The basic point is that the initial- and final-state wave functions in the two processes are the same and the transition operators are similar. The double charge exchange cross sections can be factorized in a nuclear structure term containing the matrix elements and a nuclear reaction factor. First pioneering experimental results for the {sup 40}Ca({sup 18}O,{sup 18}Ne){sup 40}Ar reaction at 270 MeV incident energy show that such cross section factorization reasonably holds for the crucial 0{sup +} → 0{sup +} transition to {sup 40}Ar{sub gs}, at least at very forward angles. (orig.)

  19. Studies of subbarrier fusion in heavy ion reactions leading to {sup 118,122,128}Ba as compound nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, D.; Bednarczyk, P.; Corradi, L.; Napoli, D.R.; Spolaore, P.; Stefanini, A.M.; Zhang, H. [Instituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Padova (Italy); Petrache, C.M. [Institute of physique and Nuclear Eng., Bucarest (Romania); Scarlassara, F.; Beghini, S.; Montagnoli, G.; Muller, L.; Segato, G.F.; Signorini, C. [Universita di Padova and Istituto Nazionale di Fisica Nucleare, Padova (Italy)

    1995-12-31

    Fusion cross sections and mean angular momenta have been measured for the reactions {sup 58}Ni + {sup 60}Ni and {sup 58,64}Ni + {sup 64}Ni at energies ranging from {approx} 10% - 15 % above to {approx} 10 % below the Coulomb barrier. Barrier distributions have been extracted directly from the fusion excitation functions. The influence on fusion of transfer channels with Q = 0, Q < 0 and Q > 0 shows up clearly with different signatures in the barrier distributions. (authors) 17 refs.

  20. Analysis of particle production in ultrarelativistic heavy-ion collisions within a two-source statistical model

    CERN Document Server

    Zhong Dao Lu; Fuchs, C; Zabrodin, E E; 10.1103/PhysRevC.66.044905

    2002-01-01

    The experimental data on hadron yields and ratios in central lead- lead and gold-gold collisions at 158A GeV/c (SPS) and square root s =130A GeV (RHIC), respectively, are analyzed within a two-source statistical model of an ideal hadron gas. A comparison with the standard thermal model is given. The two sources, which can reach the chemical and thermal equilibrium separately and may have different temperatures, particle and strangeness densities, and other thermodynamic characteristics, represent the expanding system of colliding heavy ions, where the hot central fireball is embedded in a larger but cooler fireball. The volume of the central source increases with rising bombarding energy. Results of the two-source model fit to RHIC experimental data at midrapidity coincide with the results of the one-source thermal model fit, indicating the formation of an extended fireball, which is three times larger than the corresponding core at SPS. (49 refs).

  1. Role of Barrier Modification and Nuclear Structure Effects in Sub-Barrier Fusion Dynamics of Various Heavy Ion Fusion Reactions

    Science.gov (United States)

    Gautam, Manjeet Singh; Vinod, K.; Kumar, Hitender

    2017-10-01

    The role of barrier modifications and the relevant nuclear structure effects in the fusion of the {}_8{}^{16}O+{}_{62}{}^{144,148,150,152,154}Sm and {}_3{}^{6,7}Li+{}_{62}{}^{152}Sm systems is analyzed within the context of the energy-dependent Woods-Saxon potential model (EDWSP model) and the coupled channel model. For the {}_8{}^{16}O+{}_{62}{}^{144,148,150,152,154}Sm reactions, where the colliding pairs are stable against breakup, the collective excitations and/or static deformations are sufficient to account for the observed fusion enhancement. In contrast, the model calculations overpredict the complete fusion data at above - barrier energies for the {}_3{}^{6,7}Li+{}_{62}{}^{152}Sm systems, where the importance of projectile breakup effects has been pointed out. Due to the low threshold of the alpha-breakup channel, the weakly bound projectiles ({}_3{}^{6,7}Li) break up into charged fragments before reaching the fusion barrier and consequently the complete fusion cross section is suppressed by 28% (25%) in the {}_3{}^6Li+{}_{62}{}^{152}Sm({}_3{}^7Li+{}_{62}{}^{152}Sm) reaction with respect to predictions of coupled channel calculations. However, the EDWSP model based calculations can minimize the suppression factor by as much as of 13% (8%) in the {}_3{}^6Li+{}_{62}{}^{152}Sm({}_3{}^7Li+{}_{62}{}^{152}Sm) reaction with reference to the predictions made by the coupled channel calculations. Therefore, the complete fusion data of the {}_3{}^6Li+{}_{62}{}^{152}Sm({}_3{}^7Li+{}_{62}{}^{152}Sm) reaction at above - barrier energies is reduced by 15% (17%) with respect to the expectations of the EDWSP model. The extracted suppression factors for the studied reactions are due to the modifications of the barrier profile as a consequence of the energy - dependence in nucleus-nucleus potential, and thus greater barrier modifications occur for more weakly bound system, which in turn, confirms the breakup of projectile in the incoming channel.

  2. Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL.

    Science.gov (United States)

    Zhao, H W; Sun, L T; Zhang, X Z; Guo, X H; Cao, Y; Lu, W; Zhang, Z M; Yuan, P; Song, M T; Zhao, H Y; Jin, T; Shang, Y; Zhan, W L; Wei, B W; Xie, D Z

    2008-02-01

    There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

  3. LEXUS heavy ion collisions

    CERN Document Server

    Sang Yong Jeon

    1997-01-01

    We use a Glauber-like approach to describe very energetic nucleus- nucleus collisions as a sequence of binary nucleon-nucleon collisions. No free parameters are needed: all the information comes from simple parametrizations of nucleon-nucleon collision data. Produced mesons are assumed not to interact with each other or with the original baryons. Comparisons are made to published experimental measurements of baryon rapidity and transverse momentum distributions, negative hadron rapidity and transverse momentum distributions, average multiplicities of pions, kaons, hyperons, and antihyperons, and zero degree energy distributions for sulfur-sulfur collisions at 200 GeV/c per nucleon and for lead-lead collisions at 158 GeV/c per nucleon. Good agreement is found except that the number of strange particles produced, especially antihyperons, is too small compared with experiment. We call this model LEXUS: Linear EXtrapolation of Ultrarelativistic nucleon-nucleon Scattering to heavy ion collisions. (11 refs).

  4. QCD in heavy ion collisions

    CERN Document Server

    Iancu, Edmond

    2014-04-10

    These lectures provide a modern introduction to selected topics in the physics of ultrarelativistic heavy ion collisions which shed light on the fundamental theory of strong interactions, the Quantum Chromodynamics. The emphasis is on the partonic forms of QCD matter which exist in the early and intermediate stages of a collision -- the colour glass condensate, the glasma, and the quark-gluon plasma -- and on the effective theories that are used for their description. These theories provide qualitative and even quantitative insight into a wealth of remarkable phenomena observed in nucleus-nucleus or deuteron-nucleus collisions at RHIC and/or the LHC, like the suppression of particle production and of azimuthal correlations at forward rapidities, the energy and centrality dependence of the multiplicities, the ridge effect, the limiting fragmentation, the jet quenching, or the dijet asymmetry.

  5. A search for quarks produced in heavy-ion interactions

    CERN Multimedia

    2002-01-01

    We propose to search for free fractional charges produced in 225~GeV/A heavy-ion collisions at the SPS. A tank of mercury placed in the NA38 beam stop will serve both as a production target and as an absorber to stop reaction products. Mercury from the tank will subsequently be distilled.\\\\ \\\\ This process will decrease the amount of mercury that has to be processed by a factor of about $10^{5}$. The concentrate will be searched for quarks using the proven SFSU automated Millikan apparatus.\\\\ \\\\ This experiment will be sensitive to about one quark produced per $2 \\times 10^{8}$ beam particles.

  6. Large scale collective modeling the final 'freeze out' stages of energetic heavy ion reactions and calculation of single particle measurables from these models

    Energy Technology Data Exchange (ETDEWEB)

    Nyiri, Agnes

    2005-07-01

    -relativistic heavy ion reactions is an important hadronic observable sensitive to the early stages of system evolution. The flow analysis involves the particles, which have already been frozen out. Therefore, to perform realistic flow computations from the Multi Module Model we need a complete freeze out description and a well identified freeze out surface. However, the freeze out module is still not ready. Although we have not yet been able to evaluate collective flow using the Multi Module Model, the method and code for the calculation of flow components has been worked out in an independent module. This module is completed and can be coupled to the previous modules when those are ready for use. In order to test the code, we have calculated directed and elliptic flow from a tilted, ellipsoidally expanding source using a simple, blast wave type of model. This model was developed directly for this aim based on Buda-Lund hydro models. Although, this oversimplified blast wave model is not suitable to reproduce the experimental data--which will be an important task in the future to check our Multi Module Model--it has provided us with important information. We have found that the directed flow, is very sensitive to the correct identification of the reaction plane included the determination of the impact parameter vector, and can be misinterpreted by some experimental methods. We have shown that misidentification of the reaction plane may even set the directed flow to zero by construction. We have presented results of the rapidity dependence of the directed flow, v1, and elliptic flow, v2, furthermore, the transverse momentum dependence of v2. We have also investigated the dependence of the flow pattern on the initial geometry of the fireball by calculating flow components from two ellipsoidal sources with the same thermodynamical properties but different shape. The code determining the freeze out hypersurface should still be improved in order to avoid inaccuracies in the further

  7. Ultrarelativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, H.G.

    1980-12-01

    Studies with ultrarelativistic heavy ions combine aspects of cosmic ray physics, particle physics, nuclear physics, astrophysics and cosmogenesis. The leading theoretical concerns are the behavior of matter at very high-energy density and flux, the general behavior of space time in collisions, relativistic nuclear theory, and quantum chromodynamics. The field has developed over a period of more than thirty years, since the first observation of heavy nuclei in cosmic rays and the major developments of understanding of high-energy collisions made by Fermi and Landau in the early fifties. In the late sixties the discovery of the parton content of nucleons was rapidly followed by a great extension of high-energy collision phenomenology at the CERN ISR and subsequent confirmation of the QCD theory. In parallel the study of p-nucleus and nucleus-nucleus collisions at very high energies, especially at the CERN PS, Fermilab and the Bevalac, and in cosmic rays demonstrated that studies involving the nucleus opened up a new dimension in studies of the hadronic interaction. It is now at a high level of interest on an international scale, with major new accelerators being proposed to dedicate to this kind of study.

  8. CHICO, a heavy ion detector for Gammasphere

    CERN Document Server

    Simon, M W; Wu, C Y; Gray, R W; Teng, R; Long, C

    2000-01-01

    A 4 pi position-sensitive heavy-ion detector system, CHICO, has been developed primarily for use in conjunction with the 4 pi gamma-ray facility, Gammasphere. The CHICO detector comprises an array of 20 Parallel Plate Avalanche Counters (PPACs) covering 12 deg. reactions the kinematics can be reconstructed from the measured information, allowing identification of the target- and projectile-like nuclei with a mass resolution of DELTA m/m approx 5%. The measured masses, recoil velocities, and recoil angles allow correction for Doppler shift and assignment of individual gamma-rays to decay of the correct reaction product. This paper describes the design, operation and perform...

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

    Energy Technology Data Exchange (ETDEWEB)

    Patin, Joshua Barnes [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    The study of the reactions between heavy ions and 208Pb, 209Bi, 238U, and 248Cm 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 238U(18O,xn)256-xFm, 238U(22Ne,xn)260-xNo, and 248Cm(15N,xn)263-xLr 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 48Pb(238Ca,xn)256-xNo, 208Pb(50Ti,xn)258-xRf, 208Pb(51V,xn)259-xDb, 50Bi(238Ti,xn)259-xDb, and 209Bi(51V,xn)260-xSg 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.

  10. Exotic hadrons from heavy ion collisions

    Science.gov (United States)

    Cho, Sungtae; Hyodo, Tetsuo; Jido, Daisuke; Ko, Che Ming; Lee, Su Houng; Maeda, Saori; Miyahara, Kenta; Morita, Kenji; Nielsen, Marina; Ohnishi, Akira; Sekihara, Takayasu; Song, Taesoo; Yasui, Shigehiro; Yazaki, Koichi

    2017-07-01

    High energy heavy ion collisions are excellent ways for producing heavy hadrons and composite particles, including the light (anti)nuclei. With upgraded detectors at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), it has become possible to measure hadrons beyond their ground states. Therefore, heavy ion collisions provide a new method for studying exotic hadrons that are either molecular states made of various hadrons or compact system consisting of multiquarks. Because their structures are related to the fundamental properties of Quantum Chromodynamics (QCD), studying exotic hadrons is currently one of the most active areas of research in hadron physics. Experiments carried out at various accelerator facilities have indicated that some exotic hadrons may have already been produced. The present review is a summary of the current understanding of a selected set of exotic particle candidates that can be potentially measured in heavy ion collisions. It also includes discussions on the production of resonances, exotics and hadronic molecular states in these collisions based on the coalescence model and the statistical model. A more detailed discussion is given on the results from these models, leading to the conclusion that the yield of a hadron that is a compact multiquark state is typically an order of magnitude smaller than if it is an excited hadronic state with normal quark numbers or a loosely bound hadronic molecule. Attention is also given to some of the proposed heavy exotic hadrons that could be produced with sufficient abundance in heavy ion collisions because of the significant numbers of charm and bottom quarks that are produced at RHIC and even larger numbers at LHC, making it possible to study them in these experiments. Further included in the discussion are the general formalism for the coalescence model that involves resonance particles and its implication on the present estimated yield for resonance production. Finally

  11. Heavy-ion nucleus scattering

    CERN Document Server

    Rahman, M A; Haque, S

    2003-01-01

    Heavy ion-nucleus scattering is an excellent laboratory to probe high spin phenomena, exotic nuclei and for the analysis of various exit channels. The Strong Absorption Model or the generalized diffraction models, which are semi-classical in nature, have been employed in the description of various heavy ion-nucleus scattering phenomena with reasonable success. But one needs to treat the deflection function (scattering angles) quantum mechanically in the Wave Mechanical picture for the appropriate description of the heavy-ion nucleus scattering phenomena. We have brought the mathematics for the cross-section of the heavy-ion nucleus scattering to an analytic expression taking account of the deflection function (scattering angles) quantum mechanically. sup 9 Be, sup 1 sup 6 O, sup 2 sup 0 Ne and sup 3 sup 2 S heavy-ion beams elastic scattering from sup 2 sup 8 Si, sup 2 sup 4 Mg and sup 4 sup 0 Ca target nuclei at various projectile energies over the range 20-151 MeV have been analysed in terms of the 2-paramet...

  12. The Holifield Heavy Ion Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.M.; Alton, G.D.; Ball, J.B.; Biggerstaff, J.A.; Dowling, D.T.; Erb, K.A.; Haynes, D.L.; Hoglund, D.E.; Hudson, E.D.; Juras, R.C.

    1987-01-01

    Development of the Holifield facility has continued with resulting improvements in the number of ion species provided, ion energy for tandem-only operations, and utilization efficiency. The Holifield Heavy Ion Research Facility (HHIRF) is located at the Oak Ridge National Laboratory and operated as a national user facility for research in heavy ion science. The facility operates two accelerators: an NEC pelletron tandem accelerator designed to operate at terminal potentials up to 25 MV and the Oak Ridge Isochronous Cyclotron (ORIC) which has been modified to serve as an energy booster for beams from the tandem accelerator. The principal experimental devices of the facility include a broad range spectrograph (ME/q/sup 2/ = 225) equipped with a vertical drift chamber detector system, a 4..pi.. spin spectrometer equipped with 72 NaI detectors (Ge detectors and BGO compton-suppression units can be used in place of the NaI detectors), a time-of-flight spectrometer, a 1.6-m scattering chamber, a heavy-ion/light-ion detector (HILI) which will be used for studying inverse reactions, a split-pole spectrograph, and a velocity filter. In this report, we will discuss our recent development activities, operational experience, and future development plans.

  13. The ALICE experiment: $\\rm D^{+}$-meson production in heavy-ion collisions and silicon low noise sensors characterization for the ITS Upgrade.

    CERN Document Server

    AUTHOR|(CDS)2084697; Bruna, Elena

    This thesis collects my work on two aspects of the ALICE experiment at the Large Hadron Collider: the measurement of $\\rm D^{+}$-meson production in Pb-Pb collisions at $\\sqrt{s_{\\rm {NN}}}= 2.76$ TeV and the characterization of silicon low noise sensors for the Inner Tracking System Upgrade. I worked within the INFN group of Torino that it is involved in the ALICE experiment both in the physics program related to the study of heavy-flavour production and in the project of the ITS Upgrade. ALICE is one of the main experiment of the LHC and it is the only one optimized to study ultra-relativistic heavy-ion collisions. The main goal is to study the properties of the Quark Gluon Plasma (QGP), a phase of matter where quarks and gluons are deconned. Heavy quarks are a powerful tool to study such properties because they can be created only in hard scattering processes at the initial stage of the collision and, subsequently, they interact with the QGP. The measurement of charmed meson production in Pb-P...

  14. Results of heavy ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Castro, J.R. [Lawrence Berkeley Lab., CA (United States). Life Sciences Div.

    1994-04-01

    The potential of heavy ion therapy for clinical use in cancer therapy stems from the biological parameters of heavy charged particles, and their precise dose localization. Biologically, carbon, neon and other heavy ion beams (up to about silicon) are clinically useful in overcoming the radioresistance of hypoxic tumors, thus increasing biological effectiveness relative to low-LET x-ray or electron beams. Cells irradiated by heavy ions show less variation in cell-cycle related radiosensitivity and decreased repair of radiation injury. The physical parameters of these heavy charged particles allow precise delivery of high radiation doses to tumors while minimizing irradiation of normal tissues. Clinical use requires close interaction between radiation oncologists, medical physicists, accelerator physicists, engineers, computer scientists and radiation biologists.

  15. Heavy ions: Report from Relativistic Heavy Ion Collider

    Indian Academy of Sciences (India)

    We review selected highlights from the experiments at the Relativistic Heavy Ion Collider (RHIC) exploring the QCD phase diagram. A wealth of new results appeared recently from RHIC due to major recent upgrades, like for example the Υ suppression in central nucleus-nucleus collisions which has been discovered ...

  16. Real-time mode detection of heavy ion-induced nuclear reaction products

    CERN Document Server

    Tsyganov, Yu S; Polyakov, A N; Yakushev, A B; Vakatov, V I

    2002-01-01

    Design of spectrometers of two nuclear research facilities, the Dubna Gas-filled Recoil Separator and KHIPTI is reviewed. The sources of backgrounds are discussed and techniques used to suppress these backgrounds in one-event detection experiments aimed at the synthesis of heavy elements are presented. The first system was used in 1998 in experiments on Z=114 superheavy element. We consider the possibility of detection of rare time and position correlated recoil-alpha and alpha-alpha sequences in real-time mode as basic techniques to suppress beam and target-like associated backgrounds. Fields of application of such a technique are discussed from the viewpoint of synthesis of heavy elements and by studying their chemical properties.

  17. Statistical and off-equilibrium production of fragments in heavy ion collisions at intermediate energies; Production statistique et hors-equilibre de fragments dans les collisions d`ions lourdes aux energies intermediaires

    Energy Technology Data Exchange (ETDEWEB)

    Bocage, Frederic [Lab. de Physique Corpusculaire, Caen Univ., 14 - Caen (France)

    1998-12-15

    The study of reaction products, fragments and light charged particles, emitted during heavy-ion collisions at intermediate energies has shown the dominant binary dissipative character of the reaction, which is persisting for almost all impact parameters. However, in comparison with this purely binary process, an excess of nuclear matter is observed in-between the quasi-projectile and the quasi-target. To understand the mechanisms producing such an excess, this work studies more precisely the breakup in two fragments of the quasi-projectile formed in Xe+Sn, from 25 to 50 MeV/u, and Gd+C and Gd+U at 36 MeV/u. The data were obtained during the first INDRA experiment at GANIL. The angular distributions of the two fragments show the competition between statistical fission and non-equilibrated breakup of the quasi-projectile. In the second case, the two fragments are aligned along the separation axis of the two primary partners. The comparison of the fission directions and probabilities with statistical models allows us to measure the fission time, as well as the angular momentum, temperature and size of the fissioning residue. The relative velocities are compatible with Coulomb and thermal effects in the case of statistical fission and are found much higher for the breakup of a non-equilibrated quasi-projectile, which indicates that the projectile was deformed during interaction with the target. Such deformations should be compared with dynamical calculations in order to constrain the viscosity of nuclear matter and the parameters of the nucleon-nucleon interaction, (author) 148 refs., 77 figs., 11 tabs.

  18. Future relativistic heavy ion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, H.G.

    1980-12-01

    Equations of state for nuclear matter and ongoing experimental studies are discussed. Relativistic heavy ion physics is the only opportunity to study in the laboratory the properties of extended multiquark systems under conditions such that quarks might run together into new arrangements previously unobserved. Several lines of further study are mentioned. (GHT)

  19. Production of $e^+e^-$ Pairs Accompanied by Nuclear Dissociation in Ultra-Peripheral Heavy Ion Collision

    CERN Document Server

    Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhatia, V S; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Buren; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Carroll, J; Castillo, J; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; De Moura, M M; Derevshchikov, 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; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Foley, K J; Fomenko, K; Fu, J; Gagliardi, C A; Gans, J; Ganti, M S; Gaudichet, L; Geurts, F J M; Ghazikhanian, V; Ghosh, P; González, J E; Grachov, O; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guo, Y; Gutíerrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Huang Sheng Li; Huang, H Z; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kravtsov, P; Kravtsov, V I; Krämer, M; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Le Vine, M J; Lebedev, A; Lednicky, R; Lehocka, S; Li, C; Li, Q; Li, Y; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; López-Noriega, M; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnik, Yu M; Meschanin, A; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mischke, A; Mishra, D; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Mora-Corral, M J; Morozov, D A; Morozov, V; Munhoz, M G; Nandi, B K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, Thomas; Perevozchikov, 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 V; Potrebenikova, E V; 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 M; Reid, J G; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schröder, L S; Schweda, K; Seger, J; Sen-Gupta, A; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimansky, S S; Simon, F; Singaraju, R N; Skoro, G P; Smirnov, N; Snellings, R; Sood, G; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Sørensen, P; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O; Ulery, J; Ullrich, T; Underwood, D G; Urkinbaev, A R; Van Leeuwen, M; Van der Molen, A M; Van, G; Varma, R; Vasilev, A N; Vasilevski, I M; Vernet, R; Vigdor, S E; Viyogi, V P; Vokal, S; Voloshin, S A; Vznuzdaev, M; Waggoner, B; Wang, F; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Wells, R; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zanevsky, Yu V; Zhang, H; Zhang, W M; Zhang, Z P; Zolnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

    2004-01-01

    We present the first data on $e^+e^-$ pair production accompanied by nuclear breakup in ultra-peripheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order corrections to the pair production cross section should be enhanced. We compare the pair kinematic distributions with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED); the latter includes the photon virtuality. The cross section, pair mass, rapidity and angular distributions are in good agreement with both calculations. The pair transverse momentum, $p_T$, spectrum agrees with the QED calculation, but not with the equivalent photon approach. We set limits on higher-order contributions to the cross section. The $e^+$ and $e^-$ $p_T$ spectra are similar, with no evidence for interference effects due to higher-order diagrams.

  20. Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions

    CERN Document Server

    AUTHOR|(CDS)2070213; Arnaldi, R.; Beraudo, A.; Bruna, E.; Caffarri, D.; del Valle, Z.Conesa; Contreras, J.G.; Dahms, T.; Dainese, A.; Djordjevic, M.; Ferreiro, E.G.; Fujii, H.; Gossiaux, P.B.; de Cassagnac, R.Granier; Hadjidakis, C.; He, M.; van Hees, H.; Horowitz, W.A.; Kolevatov, R.; Kopeliovich, B.Z.; Lansberg, J.P.; Lombardo, M.P.; Lourenço, C.; Martinez-Garcia, G.; Massacrier, L.; Mironov, C.; Mischke, A.; Nahrgang, M.; Nguyen, M.; Nystrand, J.; Peigné, S.; Porteboeuf-Houssais, S.; Potashnikova, I.K.; Rakotozafindrabe, A.; Rapp, R.; Robbe, P.; Rosati, M.; Rosnet, P.; Satz, H.; Schicker, R.; Schienbein, I.; Schmidt, I.; Scomparin, E.; Sharma, R.; Stachel, J.; Stocco, D.; Strickland, M.; Tieulent, R.; Trzeciak, B.A.; Uphoff, J.; Vitev, I.; Vogt, R.; Watanabe, K.; Woehri, H.; Zhuang, P.

    2016-01-01

    This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photo-production in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Unio...

  1. Forward hadron production in ultra-peripheral proton-heavy-ion collisions at the LHC and RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Mitsuka, Gaku [Universita degli Studi di Firenze, Sesto Fiorentino (Italy); INFN Sezione di Firenze, Sesto Fiorentino (Italy)

    2015-12-15

    We present a hadron production study in the forward rapidity region in ultra-peripheral proton-lead (p+Pb) collisions at the LHC and proton-gold (p + Au) collisions at RHIC. The present paper is based on the Monte Carlo simulations of the interactions of a virtual photon emitted by a fast moving nucleus with a proton beam. The simulation consists of two stages: the starlight event generator simulates the virtual photon flux, which is then coupled to the sophia, dpmjet, and pythia event generators for the simulation of particle production. According to these Monte Carlo simulations, we find large cross sections for ultra-peripheral collisions particle production, especially in the very forward region. We show the rapidity distributions for charged and neutral particles, and the momentum distributions for neutral pions and neutrons at high rapidities. These processes lead to substantial background contributions to the investigations of collective nuclear effects and spin physics. Finally we propose a general method to distinguish between proton-nucleus (p + A) inelastic interactions and ultra-peripheral collisions which implements selection cuts based on charged-particles multiplicity at mid-rapidity and/or neutron activity at negative forward rapidity. (orig.)

  2. Forward hadron production in ultra-peripheral proton–heavy-ion collisions at the LHC and RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Mitsuka, Gaku, E-mail: gaku.mitsuka@cern.ch [Università degli Studi di Firenze and INFN Sezione di Firenze, Via Sansone 1, 50019, Sesto Fiorentino, FI (Italy)

    2015-12-26

    We present a hadron production study in the forward rapidity region in ultra-peripheral proton–lead (p+Pb) collisions at the LHC and proton–gold (p+Au) collisions at RHIC. The present paper is based on the Monte Carlo simulations of the interactions of a virtual photon emitted by a fast moving nucleus with a proton beam. The simulation consists of two stages: the starlight event generator simulates the virtual photon flux, which is then coupled to the sophia, dpmjet, and pythia event generators for the simulation of particle production. According to these Monte Carlo simulations, we find large cross sections for ultra-peripheral collisions particle production, especially in the very forward region. We show the rapidity distributions for charged and neutral particles, and the momentum distributions for neutral pions and neutrons at high rapidities. These processes lead to substantial background contributions to the investigations of collective nuclear effects and spin physics. Finally we propose a general method to distinguish between proton–nucleus (p+A) inelastic interactions and ultra-peripheral collisions which implements selection cuts based on charged-particles multiplicity at mid-rapidity and/or neutron activity at negative forward rapidity.

  3. Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Andronic, A. [GSI Helmholzzentrum fuer Schwerionenforschung, Research Division, ExtreMe Matter Institute (EMMI), Darmstadt (Germany); Arleo, F. [Ecole Polytechnique, CNRS/IN2P3, Universite Paris-Saclay, Laboratoire Leprince-Ringuet, Palaiseau (France); Universite de Savoie, CNRS, Laboratoire d' Annecy-le-Vieux de Physique Theorique (LAPTh), Annecy-le-Vieux (France); Arnaldi, R.; Beraudo, A.; Bruna, E.; Scomparin, E. [INFN, Sezione di Torino, Turin (Italy); Caffarri, D.; Lourenco, C.; Woehri, H. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Del Valle, Z.C.; Hadjidakis, C.; Lansberg, J.P. [CNRS/IN2P3, Universite Paris-Saclay, IPNO, Univ. Paris-Sud, Orsay Cedex (France); Contreras, J.G.; Trzeciak, B.A. [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Prague (Czech Republic); Dahms, T. [Technische Universitaet Muenchen, Excellence Cluster Universe, Munich (Germany); Dainese, A. [INFN, Sezione di Padova, Padua (Italy); Djordjevic, M. [University of Belgrade, Institute of Physics Belgrade (Serbia); Ferreiro, E.G. [Universidad de Santiago de Compostela, Departamento de Fisica de Particulas, IGFAE, Santiago de Compostela (Spain); Fujii, H. [University of Tokyo, Institute of Physics, Tokyo (Japan); Gossiaux, P.B.; Martinez-Garcia, G.; Peigne, S.; Stocco, D. [Ecole des Mines de Nantes, Universite de Nantes, CNRS-IN2P3, SUBATECH, Nantes (France); Cassagnac, R.G. de; Mironov, C.; Nguyen, M. [Ecole Polytechnique, CNRS/IN2P3, Universite Paris-Saclay, Laboratoire Leprince-Ringuet, Palaiseau (France); He, M. [Nanjing University of Science and Technology, Department of Applied Physics, Nanjing (China); Hees, H. van [FIAS, Institute for Theoretical Physics, Frankfurt (Germany); Horowitz, W.A. [University of Cape Town, Department of Physics, Cape Town (South Africa); Kolevatov, R. [Ecole des Mines de Nantes, Universite de Nantes, CNRS-IN2P3, SUBATECH, Nantes (France); Saint-Petersburg State University, Department of High Energy Physics, Saint Petersburg (Russian Federation); Kopeliovich, B.Z.; Potashnikova, I.K.; Schmidt, I. [Centro Cientifico-Tecnologico de Valparaiso, Universidad Tecnica Federico Santa Maria, Departamento de Fisica, Valparaiso (Chile); Lombardo, M.P. [INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Massacrier, L. [CNRS/IN2P3, Universite Paris-Saclay, IPNO, Univ. Paris-Sud, Orsay Cedex (France); Ecole des Mines de Nantes, Universite de Nantes, CNRS-IN2P3, SUBATECH, Nantes (France); Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, LAL, Orsay (France); Mischke, A. [Utrecht University, Faculty of Science, Institute for Subatomic Physics, Utrecht (Netherlands); National Institute for Subatomic Physics, Amsterdam (Netherlands); Nahrgang, M. [Duke University, Department of Physics, Durham (United States); Nystrand, J. [University of Bergen, Department of Physics and Technology, Bergen (Norway); Porteboeuf-Houssais, S.; Rosnet, P. [Universite Clermont Auvergne, Universite Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique Corpusculaire (LPC), Clermont-Ferrand (France); Rakotozafindrabe, A. [IRFU/SPhN, CEA Saclay, Gif-sur-Yvette Cedex (France); Rapp, R. [Texas A and M University, Department of Physics and Astronomy, Cyclotron Institute, College Station (United States); Robbe, P. [Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, LAL, Orsay (France); Rosati, M. [Iowa State University, Ames (United States); Satz, H. [Universitaet Bielefeld, Fakultaet fuer Physik, Bielefeld (Germany); Schicker, R.; Stachel, J. [Ruprecht-Karls-Universitaet Heidelberg, Physikalisches Institut, Heidelberg (Germany); Schienbein, I. [Universite Grenoble-Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Sharma, R. [Tata Institute of Fundamental Research, Department of Theoretical Physics, Mumbai (India); Strickland, M. [Kent State University, Department of Physics, Kent (United States); Tieulent, R. [IPN-Lyon, Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, Villeurbanne (France); Uphoff, J. [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Vitev, I. [Los Alamos National Laboratory, Theoretical Division, Los Alamos (United States); Vogt, R. [Lawrence Livermore National Laboratory, Physics Division, Livermore (United States); University of California, Physics Department, Davis (United States); Watanabe, K. [University of Tokyo, Institute of Physics, Tokyo (Japan); Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE), Institute of Particle Physics, Wuhan (China); Zhuang, P. [Collaborative Innovation Center of Quantum Matter, Tsinghua University, Physics Department, Beijing (China)

    2016-03-15

    This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photoproduction in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7th Framework Programme. (orig.)

  4. Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions.

    Science.gov (United States)

    Andronic, A; Arleo, F; Arnaldi, R; Beraudo, A; Bruna, E; Caffarri, D; Del Valle, Z Conesa; Contreras, J G; Dahms, T; Dainese, A; Djordjevic, M; Ferreiro, E G; Fujii, H; Gossiaux, P-B; de Cassagnac, R Granier; Hadjidakis, C; He, M; van Hees, H; Horowitz, W A; Kolevatov, R; Kopeliovich, B Z; Lansberg, J-P; Lombardo, M P; Lourenço, C; Martinez-Garcia, G; Massacrier, L; Mironov, C; Mischke, A; Nahrgang, M; Nguyen, M; Nystrand, J; Peigné, S; Porteboeuf-Houssais, S; Potashnikova, I K; Rakotozafindrabe, A; Rapp, R; Robbe, P; Rosati, M; Rosnet, P; Satz, H; Schicker, R; Schienbein, I; Schmidt, I; Scomparin, E; Sharma, R; Stachel, J; Stocco, D; Strickland, M; Tieulent, R; Trzeciak, B A; Uphoff, J; Vitev, I; Vogt, R; Watanabe, K; Woehri, H; Zhuang, P

    This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photoproduction in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7[Formula: see text] Framework Programme.

  5. Relativistic heavy ions physics

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.

    1989-01-01

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

  6. Semiholography for heavy ion collisions

    CERN Document Server

    Mukhopadhyay, Ayan

    2017-01-01

    The formation of QGP in heavy ion collisions gives us a great opportunity for learning about nonperturbative dynamics of QCD. Semiholography provides a new consistent framework to combine perturbative and non-perturbative effects in a coherent way and can be applied to obtain an effective description for heavy ion collisions. In particular, it allows us to include nonperturbative effects in existing glasma effective theory and QCD kinetic theory for the weakly coupled saturated degrees of freedom liberated by the collisions in the initial stages in a consistent manner. We argue why the full framework should be able to confront experiments with only a few phenomenological parameters and present feasibility tests for the necessary numerical computations. Furthermore, we discuss that semiholography leads to a new description of collective flow in the form of a generalised non-Newtonian fluid. We discuss some open questions which we hope to answer in the near future.

  7. Estimating nonlinear effects in forward dijet production in ultra-peripheral heavy ion collisions at the LHC

    Science.gov (United States)

    Kotko, P.; Kutak, K.; Sapeta, S.; Stasto, A. M.; Strikman, M.

    2017-05-01

    Using the framework that interpolates between the leading power limit of the color glass condensate and the high energy (or kT) factorization we calculate the direct component of the forward dijet production in ultra-peripheral Pb-Pb collisions at CM energy 5.1 TeV per nucleon pair. The formalism is applicable when the average transverse momentum of the dijet system PT is much bigger than the saturation scale Qs, PT≫ Qs, while the imbalance of the dijet system can be arbitrary. The cross section is uniquely sensitive to the Weizsäcker-Williams (WW) unintegrated gluon distribution, which is far less known from experimental data than the most common dipole gluon distribution appearing in inclusive small- x processes. We have calculated cross sections and nuclear modification ratios using WW gluon distribution obtained from the dipole gluon density through the Gaussian approximation. The dipole gluon distribution used to get WW was fitted to the inclusive HERA data with the nonlinear extension of unified BFKL + DGLAP evolution equation. The saturation effects are visible but rather weak for realistic pT cut on the dijet system, reaching about 20% with the cut as low as 6 GeV. We find that the LO collinear factorization with nuclear leading-twist shadowing predicts quite similar effects.

  8. Production of highly charged heavy ions by 18 GHz superconducting electron cyclotron resonance at Research Center for Nuclear Physics.

    Science.gov (United States)

    Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

    2010-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source has been installed as a subject of the azimuthally varying field cyclotron upgrade project (K. Hatanaka et al., in Proceedings of the 17th International Conference on Cyclotrons and Their Applications, Tokyo, Japan, 18-22 October 2004, pp. 115-117), in order to increase beam currents and to extend the variety of ions. The production development of several ions has been performed since 2006 and some of them have already been used for user experiments [T. Yorita et al., Rev. Sci. Instrum. 79, 02A311 (2008)]. Further optimizations for each component such as the material of plasma electrode, material, and shape of bias probe and mirror field have been continued and more intense ion beams have been obtained for O, N, and Ar. For the purpose of obtaining highly charged Xe with several microamperes, the optimization of position and shape of plasma electrode and bias disk has also been done and highly charged Xe(32+) beam has been obtained successfully.

  9. Holifield Heavy Ion Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.M.; Alton, G.D.; Ball, J.B.; Biggerstaff, J.A.; Dowling, D.T.; Erb, K.A.; Haynes, D.L.; Hoglund, D.E.; Hudson, E.D.; Juras, R.C.

    1986-02-15

    The Holifield Heavy Ion Research Facility has been in routine operation since July 1982. Beams have been provided using both the tandem accelerator alone and a coupled mode in which the Oak Ridge Isochronous Cyclotron is used as an energy booster for tandem beams. The coupled mode has proved to be especially effective and has allowed us to provide a wide range of energetic beams for scheduled experiments. In this report we discuss our operational experience and recent development activities.

  10. Holifield Heavy Ion Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.M.; Alton, G.D.; Ball, J.B.; Biggerstaff, J.A.; Dowling, D.T.; Erb, K.A.; Haynes, D.L.; Hoglund, D.E.; Hudson, E.D.; Juras, R.C.

    1985-01-01

    The Holifield Heavy Ion Research Facility has been in routine operation since July 1982. Beams have been provided using both the tandem accelerator alone and a coupled mode in which the Oak Ridge Isochronous Cyclotron is used as an energy booster for tandem beams. The coupled mode has proved to be especially effective and has allowed us to provide a wide range of energetic beams for scheduled experiments. In this report we discuss our operational experience and recent development activities.

  11. Heavy ion therapy: Bevalac epoch

    Energy Technology Data Exchange (ETDEWEB)

    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)

  12. Chromosome Aberrations by Heavy Ions

    Science.gov (United States)

    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.

  13. Electromagnetic dissociation effects in galactic heavy-ion fragmentation

    Science.gov (United States)

    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.

  14. Heavy Ion Physics at CMS

    CERN Document Server

    Veres, Gabor

    2017-01-01

    In the present proceedings recent heavy ion results from the Compact Muon Solenoid collaboration at the LHC are presented. These contain comparisons between small and large collision systems, as well as studies of energy evolution, thus include data collected in proton-proton collisions at 13 TeV (2015 and 2016), proton-proton and lead-lead collisions at 5 TeV (2015), and proton-lead collisions at 5 TeV and 8 TeV (2016) center-of-mass energy per nucleon pair. They provide new insights into the properties of the extremely high density and high temperature matter created in heavy ion collisions, while pointing out similarities and differences in comparison to smaller collision systems. These include gluon distribution functions in the lead nucleus; the azimuthal anisotropy of final state particle distributions in all the three different collision systems; charge separation signals from proton-lead collisions and consequences for the Chiral Magnetic Effect; new studies of parton energy loss and its dependence on...

  15. Studying heavy-ion collisions with FAUST-QTS

    Directory of Open Access Journals (Sweden)

    Cammarata P.

    2015-01-01

    Full Text Available Heavy-ion collisions at lower energies provide a rich environment for investigating reaction dynamics. Recent theory has suggested a sensitivity to the symmetry energy and the equation of state via deformations of the reaction system and ternary breaking of the deformed reaction partners into three heavy fragments. A new detection system has been commissioned at Texas A&M University in an attempt to investigate some of the observables sensitive to the nuclear equation of state.

  16. Relativistic heavy-ion physics: Experimental overview

    Indian Academy of Sciences (India)

    Abstract. The field of relativistic heavy-ion physics is reviewed with emphasis on new results and highlights from the first run of the relativistic heavy-ion collider at BNL and the 15 year research programme at the super proton synchrotron (SPS) at CERN and the AGS at BNL.

  17. Rho0 Photoproduction in Ultra-Peripheral Relativistic Heavy Ion Collisions with STAR

    Energy Technology Data Exchange (ETDEWEB)

    STAR Coll

    2007-12-20

    Photoproduction reactions occur when the electromagnetic field of a relativistic heavy ion interacts with another heavy ion. The STAR collaboration presents a measurement of {rho}{sup 0} and direct {pi}{sup +}{pi}{sup -} photoproduction in ultra-peripheral relativistic heavy ion collisions at {radical}s{sub NN} = 200 GeV. We observe both exclusive photoproduction and photoproduction accompanied by mutual Coulomb excitation. We find a coherent cross-section of {sigma}(AuAu {yields} Au*Au* {rho}{sup 0}) = 530 {+-} 19 (stat.) {+-} 57 (syst.) mb, in accord with theoretical calculations based on a Glauber approach, but considerably below the predictions of a color dipole model. The {rho}{sup 0} transverse momentum spectrum (p{sub T}{sup 2}) is fit by a double exponential curve including both coherent and incoherent coupling to the target nucleus; we find {sigma}{sub inc}/{sigma}{sub coh} = 0.29 {+-} 0.03 (stat.) {+-} 0.08 (syst.). The ratio of direct {pi}{sup +}{pi}{sup -} production is comparable to that observed in {gamma}p collisions at HERA, and appears to be independent of photon energy. Finally, the measured {rho}{sup 0} spin helicity matrix elements agree within errors with the expected s-channel helicity conservation.

  18. Photoluminescence and Raman studies in swift heavy ion irradiated ...

    Indian Academy of Sciences (India)

    Administrator

    Swift heavy ions (SHI) cause intense electronic excita- tions along the ion trajectory when they pass through material that may result in defect production or amorphiza- tion or phase transformation on nanometer scale (Bolse et al 2004; Wang et al 2004). Thus, it is interesting to know the effect of strong electronic excitation ...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  1. Relativistic heavy-ion physics: three lectures

    CERN Document Server

    McLerran, L

    2007-01-01

    These lectures provide an introduction to the physics issues which are being studied in the collisions of ultrarelativistic heavy ions. The lectures are focused on the production of new states of matter. The quark-gluon plasma is thermal matter which once existed in the Big Bang. The colour glass condensate is a universal form of high energy density gluonic matter which is part of a hadron wavefunction and which controls the high-energy limit of strong interactions. The glasma is matter produced in the collisons of high-energy hadrons which evolves into a quarkgluon plasma. The glasma has interesting topological properties and may be responsible for the early thermalization seen at RHIC. I introduce the student to these topics, discuss results from experiments, and comment upon future opportunities.

  2. Heavy ion deep inelastic collisions studied by discrete gamma ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Krolas, W. [The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

    1996-05-01

    The discrete gamma ray spectroscopy has been used as a tool to investigate the heavy ion collision. It has been shown that such experimental information supplemented by results of additional of-line radioactivity measurements is complete enough to reconstruct distributions of products of very complex nuclear reactions. Three experiments have been performed in which the {sup 208}Pb + {sup 64}Ni, {sup 130}Te + {sup 64}Ni and {sup 208}Pb + {sup 58}Ni systems have been created. The production cross sections of fragment isotopes have been determined and compared with existing model predictions 64 refs, 59 figs, 19 tabs

  3. K-shell X-ray production cross sections in Ti by 0.3–1.0 MeV/u {sup 12}C and {sup 28}Si ions for heavy ion PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Msimanga, M., E-mail: MsimangaM@tut.ac.za [Physics Department, Tshwane University of Technology, P Bag X680, Pretoria 0001 (South Africa); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P. O. Box 722, Somerset West 7129 (South Africa); Faculty of Health & Wellness Sciences, C.P.U.T., Bellville (South Africa); Madhuku, M. [iThemba LABS Gauteng, National Research Foundation, P Bag 11, WITS 2050, Johannesburg (South Africa)

    2016-08-01

    An inhibiting factor in the implementation of heavy ion PIXE is that heavy ion X-ray production cross sections are not well known for many materials. This contribution reports on work carried out at iThemba LABS to measure X-ray production cross-sections in Ti thin films irradiated with {sup 12}C and {sup 28}Si ions within the 0.3–1.0 MeV/u energy range. Experimental data are compared to predictions by the PWBA, SCA-UA and ECPSSR theories. For the C–Ti asymmetric collision, ECPSSR theory describes experiment fairly well, but fails for the nearly symmetric Si–Ti collision, even after correction for multiple ionisation effects. The SCA-UA calculations tend to agree with data only at low (<0.5 MeV/u) energies for the lighter {sup 12}C incident ions, but like ECPSSR, fail in the case of {sup 28}Si projectiles. The PWBA predictions grossly overestimate experiment in both cases.

  4. heavy ion acceleration at shocks

    Science.gov (United States)

    Shevchenko, V. I.; Galinsky, V.

    2009-12-01

    The theoretical study of alpha particle acceleration at a quasi-parallel shock due to interaction with Alfven waves self-consistently excited in both upstream and downstream regions was conducted using a scale-separation model [1]. The model uses conservation laws and resonance conditions to find where waves will be generated or dumped and hence particles will be pitch--angle scattered as well as the change of the wave energy due to instability or damping. It includes in consideration the total distribution function (the bulk plasma and high energy tail), so no any assumptions (e.g. seed populations, or some ad-hoc escape rate of accelerated particles) are required. In previous studies heavy ions were treated as perfect test particles, they only experienced the Alfven turbulence excited by protons and didn’t contribute to turbulence generation. In contrast to this approach, we consider the ion scattering on hydromagnetic turbulence generated by both protons and ions themselves. It is important for alpha particles with their relatively large mass-loading parameter that defines efficiency of the wave excitation by alpha particles. The energy spectra of alpha particles is found and compared with those obtained in test particle approximation. [1] Galinsky, V.L., and V.I. Shevchenko, Astrophys. J., 669, L109, 2007.

  5. Heavy Ion Fusion Accelerator Research (HIFAR)

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Electron cloud studies for heavy-ion and proton machines

    CERN Document Server

    Petrov, F; Weiland, Th

    2013-01-01

    Electron cloud effects are a known problem in various accelerator facilities around the world. Electron clouds cause instabilities and emittance growth in positron and proton beams as well as in heavy ion beams. Most of the hadron machines experience the build-up of EC due to the multipacting. In LHC and in positron machines production of electrons due to the synchrotron radiation becomes as important as the build-up due to the secondary emission. The main source of seed electrons in heavy ion machines is the residual gas ionization. FAIR facility in Darmstadt will operate with heavy-ion and proton beams. However, the beam parameters are such that the multipacting will start to play a role only for the unconditioned wall with the secondary emission yieldmore than 1.8. In this paperwe study the electron cloud build-up and its effect on the beam stability for FAIR heavy-ion coasting beams. These beams will be used during slow extraction. Electron scattering on the beam ions and its effect on the final neutraliz...

  7. Transport theory of deeply inelastic heavy-ion collisions based on a random-matrix model. III. Calculation of cross sections. Comparison with the reaction Ar+Th

    Energy Technology Data Exchange (ETDEWEB)

    Agassi, D.; Ko, C.M.; Weidenmueller, H.A.

    1979-02-01

    The transport equation deduced previously is cast into a form which allows for numerical computation of cross sections. The approximations, especially the moments approach, are exhibited, as are the essential points of the numerical procedure. The validity of the Einstein relation is discussed. Doubly differential cross sections for various fragments produced in the reaction /sup 40/Ar+/sup 232/Th are calculated and compared with experimental data.

  8. Proceedings of the heavy ion fusion workshop

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R C [ed.

    1978-01-01

    These proceedings contain reviews of current laboratory programs dealing with inertial fusion driven by beams of heavy ions, as well as several individually abstracted invited talks, workshop reports and contributed papers.

  9. Heavy-ion performance of the LHC and future colliders

    Energy Technology Data Exchange (ETDEWEB)

    Schaumann, Michaela

    2015-04-29

    In 2008 the Large Hadron Collider (LHC) and its experiments started operation at the European Centre of Nuclear Research (CERN) in Geneva with the main aim of finding or excluding the Higgs boson. Only four years later, on the 4th of July 2012, the discovery of a Higgs-like particle was proven and first published by the two main experiments ATLAS and CMS. Even though proton-proton collisions are the main operation mode of the LHC, it also acts as an heavy-ion collider. Here, the term ''heavy-ion collisions'' refers to the collision between fully stripped nuclei. While the major hardware system of the LHC is compatible with heavy-ion operation, the beam dynamics and performance limits of ion beams are quite different from those of protons. Because of the higher mass and charge of the ions, beam dynamic effects like intra-beam scattering and radiation damping are stronger. Also the electromagnetic cross-sections in the collisions are larger, leading to significantly faster intensity decay and thus shorter luminosity lifetimes. As the production cross-sections for various physics processes under study of the experiments are still small at energies reachable with the LHC and because the heavy-ion run time is limited to a few days per year, it is essential to obtain the highest possible collision rate, i.e. maximise the instantaneous luminosity, in order to obtain enough events and therefore low statistical errors. Within this thesis, the past performance of the LHC in lead-lead (Pb-Pb) collisions, at a centre-of-mass energy of 2.76 TeV per colliding nucleon pair, is analysed and potential luminosity limitations are identified. Tools are developed to predict future performance and techniques are presented to further increase the luminosity. Finally, a perspective on the future of high energy heavy-ion colliders is given.

  10. From heavy ions to exotic atoms

    OpenAIRE

    Indelicato, Paul; Trassinelli, Martino

    2005-01-01

    We review a number of experiments and theoretical calculations on heavy ions and exotic atoms, which aim at providing informations on fundamental interactions. Among those are propositions of experiments for parity violation measurements in heavy ions and high-precision mesurements of He-like transition energies in highly charged ions. We also describe recent experiments on pionic atoms, that make use of highly-charged ion transitions to obtain accurate measurements of strong interaction shif...

  11. The search for super-heavy ions

    CERN Document Server

    Grévy, S

    2003-01-01

    The present the search for heavy nuclei, they briefly draw a historical review of the production of heavy isotopes and then describe the means and possibilities the French GANIL (national great accelerator of heavy ions) facility offers. The different steps of the experimental process are described: production, selection, detection and identification. The production cross-sections are so weak that every parameter involved in the production process has to be optimized. It appears that the limit of our technological knowledge has been reached and unless an important technical step forward it seems impossible to go down below the pico-barn (10 sup - sup 1 sup 2 *10 sup - sup 2 sup 4 cm sup 2) for production cross-sections. The 2 remaining ways to improve the situation are: 1) to increase the intensity of the incident particle beam (today we have < 10 sup 1 sup 3 pps), this implies that an important development about accelerators and ion sources has to be achieved, 2) the other way is to use radioactive ion be...

  12. Particle Production in pp and Heavy Ion Collisions from $\\sqrt{s_{NN}}$ = 200 GeV to 5.5 TeV

    CERN Document Server

    Mondal, Mriganka Mouli; Chattopadhyay, Subhasis

    Exploring the creation of Quark Gluon Plasma (QGP), a new state of Nuclear matter is the main aim in Relativistic Heavy Ion collision experiments which √ are being performed in the STAR experiment at RHIC ( s = 200 GeV) and √ ALICE ( s = 5.5 TeV) experiment at LHC. Various observables derived from the properties of the produced particles of the interacting system. Specialized detectors are built for detection of specific types of particles. Dedicated efforts are made in data analysis studying the observables in the soft and hard sector in AA collisions which are then compared with the results form pp and dAu collisions for attaining at a consistent picture. In this thesis as a part of the detector developmental work, fabrication and testing of the Photon Multiplic- ity Detector (PMD) installed in the ALICE experiment at LHC have been discussed. A detailed√ simulation using PYTHIA with GEANT is performed with pp collision (at s = 14 TeV) events at LHC as a readiness exercise of data analysis in such coll...

  13. Probing subnucleon scale fluctuations in ultraperipheral heavy ion collisions

    Science.gov (United States)

    Mäntysaari, Heikki; Schenke, Björn

    2017-09-01

    We show that introducing subnucleon scale fluctuations constrained by HERA diffractive J / Ψ production data significantly affects the incoherent diffractive J / Ψ production cross section in ultraperipheral heavy ion collisions. We find that the inclusion of the additional fluctuations increases the ratio of the incoherent to the coherent cross section approximately by a factor of 2, and modifies the transverse momentum spectra of the produced J / Ψ at momenta larger than the scale that corresponds to the distance scale of the subnucleonic fluctuations. We present predictions for J / Ψ production in ultraperipheral heavy ion collisions at √{sNN} = 5.02 TeV at the LHC and 200 GeV at RHIC.

  14. Probing subnucleon scale fluctuations in ultraperipheral heavy ion collisions

    Directory of Open Access Journals (Sweden)

    Heikki Mäntysaari

    2017-09-01

    Full Text Available We show that introducing subnucleon scale fluctuations constrained by HERA diffractive J/Ψ production data significantly affects the incoherent diffractive J/Ψ production cross section in ultraperipheral heavy ion collisions. We find that the inclusion of the additional fluctuations increases the ratio of the incoherent to the coherent cross section approximately by a factor of 2, and modifies the transverse momentum spectra of the produced J/Ψ at momenta larger than the scale that corresponds to the distance scale of the subnucleonic fluctuations. We present predictions for J/Ψ production in ultraperipheral heavy ion collisions at sNN=5.02 TeV at the LHC and 200 GeV at RHIC.

  15. Relation between hard photon production and impact parameter in heavy ion collisions at intermediate energies; Dependance de la production de photons durs avec le parametre d`impact dans les collisions entre ions lourds aux energies intermediaires

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Garcia, G.

    1994-06-01

    Hard photons produced in heavy-ions collisions at intermediate energies have been used in order to study hot and compresses nuclear matter created in these collisions (at Ganil). It was found that Bremsstrahlung radiation emitted in np collisions is the main mechanism of hard-photon production for the whole range of impact parameter. Moreover, it was observed a substantial decrease of the hardness of hard-photon spectrum. The BUU model reproduces very well the experimental results, showing that the hardness of the spectrum reflects, mainly, nuclear-matter compression in the first stage of the collision. A new method was developed to measure the density of the nuclear matter created at the beginning of the collision. BUU results and some experimental evidences point out that a significant contribution of hard photons are produced in the last stage of the collision: thermal hard photons. These photons are sensitive to the density oscillation of nuclear matter. Its production cross-section will constitute a measurement of the compressibility of nuclear matter and its spectrum a measure of the temperature. (from author) 64 figs., 60 refs.

  16. Fragment production in central heavy-ion collisions: reconciling the dominance of dynamics with observed phase transition signals through universal fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Frankland, J.D.; Chbihi, A.; Hudan, S. [and others

    2002-07-01

    Fragment production in central collisions of Xe+Sn has been systematically studied with the INDRA multidetector from 25 to 150 AMeV. The predominant role of collision dynamics is evidenced in multiple intermediate mass fragment production even at the lowest energies, around the so-called multifragmentation threshold. For beam energies 50 AMeV and above, a promising agreement with suitably modified Anti-symmetrized Molecular Dynamics calculations has been achieved. Intriguingly the same reactions have recently been interpreted as evidence for a liquid-gas phase transition in thermodynamically equilibrated systems. The universal fluctuation theory, thanks to its lack of any equilibrium hypothesis, shows clearly that in all but a tiny minority of carefully-selected central collisions fragment production is incompatible with either critical or phase coexistence behaviour. On the other hand, it does not exclude some similarity with aggregation scenarios such as the lattice-gas or Fisher droplet models. (authors)

  17. Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders

    Directory of Open Access Journals (Sweden)

    Ashwini Kumar

    2013-01-01

    Full Text Available The present paper reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for charged hadrons produced in such high energy collisions. Various features of available experimental data, for example, the variations of charged hadron multiplicity and pseudorapidity density with the mass number of colliding nuclei, center-of-mass energies, and the collision centrality obtained from heavy-ion collider experiments, are interpreted in the context of various theoretical concepts and their implications. Finally, several important scaling features observed in the measurements mainly at RHIC and LHC experiments are highlighted in the view of these models to draw some insight regarding the particle production mechanism in heavy-ion collisions.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Nigel Oswald [Univ. of California, Berkeley, CA (United States)

    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 ~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, ~200 g/cm3 and ~20 keV, that a substantial number of fusion reactions occur; the pellet microexplosion typically releases ~350 MJ of energy in optimized power plant scenarios.

  20. Two-pion correlations in heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Heavy ion transfer reactions: Status and perspectives

    Indian Academy of Sciences (India)

    respond to the transfer of two neutrons in the p3/2 orbital, and we remind that the single-particle form-factors for the p3/2 orbital is much larger than the one for the .... trajectory. The imaginary potential W(r), that describes the depopulation of the entrance channel, at very low energies is dominated by the single-nucleon ...

  2. Electromagnetic Radiations from Heavy Ion Collision

    Directory of Open Access Journals (Sweden)

    Payal Mohanty

    2013-01-01

    Full Text Available In this review, we have discussed the different sources of photons and dileptons produced in heavy ion collision (HIC. The transverse momentum (pT spectra of photons for different collision energies are analyzed with a view of extracting the thermal properties of the system formed in HIC. We showed the effect of viscosity on pT spectra of produced thermal photons. The dilepton productions from hot hadrons are considered including the spectral change of light vector mesons in the thermal bath. We have analyzed the pT and invariant mass (M spectra of dileptons for different collision energies too. As the individual spectra are constrained by certain unambiguous hydrodynamical inputs, so we evaluated the ratio of photon to dilepton spectra, Rem, to overcome those quantities. We argue that the variation of the radial velocity extracted from Rem with M is indicative of a phase transition from the initially produced partons to hadrons. In the calculations of interferometry involving dilepton pairs, it is argued that the nonmonotonic variation of HBT radii with invariant mass of the lepton pairs signals the formation of quark gluon plasma in HIC. Elliptic flow (v2 of dilepton is also studied at sNN=2.76 TeV for 30–40% centrality using the (2+1d hydrodynamical model.

  3. What have we learned from jets in heavy ion collisions

    Science.gov (United States)

    Nattrass, Christine

    2017-09-01

    The Quark-Gluon Plasma (QGP) is created in high energy heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). The properties of this medium is transparent to electromagnetic probes but nearly opaque to colored probes. Hard partons fragment and hadronize into a collimated spray of particles called a jet. The partons lose energy as they traverse the medium, a process called jet quenching. Most of the lost energy is still correlated with the parent parton, contributing to particle production at larger angles and lower momenta relative to the parent parton than in proton-proton collisions. This partonic energy loss can be measured through several observables, each of which give different insights into the degree and mechanism of energy loss. The measurements to date are summarized and the path forward is discussed.

  4. Jet studies in heavy ion collisions with the ATLAS detector

    CERN Document Server

    Slovak, Radim; The ATLAS collaboration

    2016-01-01

    In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. Jets are produced at the early stages of this collision and are known to become attenuated as they propagate through the hot matter. One manifestation of this energy loss is a lower yield of jets emerging from the medium than expected in the absence of medium effects. ATLAS has provided a quantification of this jet suppression by the jet Raa measurement in run 1 of LHC. A factor of two suppression was seen in central heavy ion collisions with respect to pp collisions. The Raa exhibited only a week, if any, rapidity dependence, and a slow rise with increasing jet momentum. This talk summarizes the run 1 results on the inclusive jet production and the new results on dijet measurements.

  5. Multiple beam induction accelerators for heavy ion fusion

    Energy Technology Data Exchange (ETDEWEB)

    Seidl, Peter A., E-mail: paseidl@lbl.gov [Lawrence Berkeley National Laboratory, US (United States); Barnard, John J. [Lawrence Livermore National Laboratory, US (United States); Faltens, Andris [Lawrence Berkeley National Laboratory, US (United States); Friedman, Alex [Lawrence Livermore National Laboratory, US (United States); Waldron, William L. [Lawrence Berkeley National Laboratory, US (United States)

    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.

  6. Heavy ion induced mutation in arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Tano, Shigemitsu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Heavy ions, He, C, Ar and Ne were irradiated to the seeds of Arabidopsis thaliana for inducing the new mutants. In the irradiated generation (M{sub 1}), germination and survival rate were observed to estimate the relative biological effectiveness in relation to the LET including the inactivation cross section. Mutation frequencies were compared by using three kinds of genetic loci after irradiation with C ions and electrons. Several interesting new mutants were selected in the selfed progenies of heavy ion irradiated seeds. (author)

  7. Bremsstrahlung from relativistic heavy ions in matter

    DEFF Research Database (Denmark)

    Sørensen, Allan Hvidkjær

    2010-01-01

    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....... 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...

  8. European heavy ion ICF driver development

    CERN Document Server

    Plass, Günther

    1996-01-01

    Approaches in Europe to heavy ion induced Inertial Confinement Fusion are oriented toward the linac-plus- storage ring technique. Despite the very limited support of this work, technical pro gress was achieved in some important areas. For the immediate future, a substantial intensity upgrade of the GSI accelerator facilities at Darmstadt is being implemented, leading to specific energy depositions of the order of 100 kJ/g and plasma temperatures of 10 to 20 eV. For the longer term, a conceptual design study of a heavy ion based Ignition Facility is being initiated.

  9. Jets in heavy ion collisions with CMS

    CERN Document Server

    Salur, Sevil

    2016-01-01

    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.

  10. What Can We Learn From Proton Recoils about Heavy-Ion SEE Sensitivity?

    Science.gov (United States)

    Ladbury, Raymond L.

    2016-01-01

    The fact that protons cause single-event effects (SEE) in most devices through production of light-ion recoils has led to attempts to bound heavy-ion SEE susceptibility through use of proton data. Although this may be a viable strategy for some devices and technologies, the data must be analyzed carefully and conservatively to avoid over-optimistic estimates of SEE performance. We examine the constraints that proton test data can impose on heavy-ion SEE susceptibility.

  11. Magnetic Monopole Mass Bounds from Heavy-Ion Collisions and Neutron Stars.

    Science.gov (United States)

    Gould, Oliver; Rajantie, Arttu

    2017-12-15

    Magnetic monopoles, if they exist, would be produced amply in strong magnetic fields and high temperatures via the thermal Schwinger process. Such circumstances arise in heavy-ion collisions and in neutron stars, both of which imply lower bounds on the mass of possible magnetic monopoles. In showing this, we construct the cross section for pair production of magnetic monopoles in heavy-ion collisions, which indicates that they are particularly promising for experimental searches such as MoEDAL.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. A heavy load for heavy ions

    CERN Multimedia

    2003-01-01

    On 25 September, the two large coils for the dipole magnet of ALICE, the LHC experiment dedicated to heavy ions, arrived at Point 2 on two heavy load trucks after a 1200 km journey from their assembly in Vannes, France.

  14. HIGH DENSITY QCD WITH HEAVY-IONS

    CERN Multimedia

    The Addendum 1 to Volume 2 of the CMS Physics TDR has been published The Heavy-Ion analysis group completed the writing of a TDR summarizing the CMS plans in using heavy ion collisions to study high density QCD. The document was submitted to the LHCC in March and presented in the Open Session of the LHCC on May 9th. The study of heavy-ion physics at the LHC is promising to be very exciting. LHC will open a new energy frontier in ultra-relativistic heavy-ion physics. The collision energy of heavy nuclei at sNN = 5.5 TeV will be thirty times larger than what is presently available at RHIC. We will certainly probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research programme is to study the fundamental theory of the strong interaction - Quantum Chromodynamics (QCD) - in extreme conditions of temperature, density and parton momentum fraction (low-x). Such studies, with impressive experimental and theoretical advances in recent years thanks to the wealth of high-qua...

  15. Working group report: Heavy ion physics

    Indian Academy of Sciences (India)

    Working group report: Heavy ion physics. Coordinator: JAN-E ALAM1. Contributors: K Assamagan2, S Chattopadhyay1, R Gavai3, Sourendu Gupta3,. B Layek4, S Mukherjee3, R Ray3, Pradip K Roy5 and A Srivastava4. 1Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064, India. 2Brookhaven National ...

  16. Superconducting heavy-ion accelerating structures

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.

    1996-08-01

    This paper briefly reviews the technical history of superconducting ion-accelerating structures. Various superconducting cavities currently used and being developed for use in ion linacs are discussed. Principal parameters and operational characteristics of superconducting structures in active use at various heavy-ion facilities are described.

  17. Working group report: Heavy ion physics

    Indian Academy of Sciences (India)

    The 8th workshop on high energy physics phenomenology (WHEPP-8) was held at the Indian Institute of Technology, Mumbai, India during January 5–16, 2004. One of the four working groups, group III was dedicated to QCD and heavy ion physics (HIC). The present manuscript gives a summary of the activities of group III ...

  18. Green's function methods in heavy ion shielding

    Science.gov (United States)

    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. Metastable states of highly excited heavy ions

    Science.gov (United States)

    Pegg, D. J.; Griffin, P. M.; Sellin, I. A.; Smith, W. W.; Donnally, B.

    1973-01-01

    Description of the method used and results obtained in an experimental study of the metastable states of highly stripped heavy ions, aimed at determining the lifetimes of such states by the rates of autoionization and radiation. The significance and limitations of the results presented are discussed.

  20. Relativistic heavy-ion physics: Experimental overview

    Indian Academy of Sciences (India)

    highlights from the first run of the relativistic heavy-ion collider at BNL and the 15 year research programme at the super ... The energy dependence of the charged particle density dNch/dη, normalized to the num- ..... meson both in the dropping mass and the collision broadening scenarios, is almost as high at RHIC as at ...

  1. Multifragmentation and dynamics in heavy ion collisions

    Indian Academy of Sciences (India)

    A midrapidity zone formed in heavy-ion collisions has been investigated through special selections of light .... lished from analysing charged particles emitted at velocities between those characteristic of projectilelike .... only, one low and one high, are displayed (more complete results are given in [15]). For the QP source ...

  2. Heavy-Ion Physics in a Nutshell

    Directory of Open Access Journals (Sweden)

    Hirano Tetsufumi

    2013-05-01

    Full Text Available The physics of quark gluon plasma (QGP and heavy ion collisions at the collider energies is briefly reviewed. We first discuss about the discovery of a nearly perfect fluidity of the QGP. We also highlights recent topics on responses of the QGP to initial deformation and propagation of a jet.

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

    Science.gov (United States)

    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. New beam for the CERN fixed target heavy ion programme

    CERN Document Server

    Hill, C E; O'Neill, M

    2002-01-01

    The physicists of the CERN heavy ion community (SPS fixed target physics) have requested lighter ions than the traditional lead ions, to scale their results and to check their theories. Studies have been carried out to investigate the behaviour of the ECR4 for the production of an indium beam. Stability problems and the low melting point of indium required some modifications to the oven power control system which will also benefit normal lead ion production. Present results of the source behaviour and the ion beam characteristics will be presented.

  5. Heavy ion results from ATLAS

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00241915; The ATLAS collaboration

    2017-01-01

    These proceedings provide an overview of the new results obtained with the ATLAS Detector at the LHC, which are presented in the Quark Matter 2017 conference. These results are covered in twelve parallel talks, one flash talk and eleven posters, and they are grouped into five areas: initial state, jet quenching, quarkonium production, longitudinal flow dynamics, and collectivity in small systems.

  6. Computing for Heavy Ion Physics

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, G.; Schiff, D.; Hristov, P.; Menaud, J.M.; Hrivnacova, I.; Poizat, P.; Chabratova, G.; Albin-Amiot, H.; Carminati, F.; Peters, A.; Schutz, Y.; Safarik, K.; Ollitrault, J.Y.; Hrivnacova, I.; Morsch, A.; Gheata, A.; Morsch, A.; Vande Vyvre, P.; Lauret, J.; Nief, J.Y.; Pereira, H.; Kaczmarek, O.; Conesa Del Valle, Z.; Guernane, R.; Stocco, D.; Gruwe, M.; Betev, L.; Baldisseri, A.; Vilakazi, Z.; Rapp, B.; Masoni, A.; Stoicea, G.; Brun, R

    2005-07-01

    This workshop was devoted to the computational technologies needed for the heavy quarkonia and open flavor production study at LHC (large hadron collider) experiments. These requirements are huge: peta-bytes of data will be generated each year. Analysing this will require the equivalent of a few thousands of today's fastest PC processors. The new developments in terms of dedicated software has been addressed. This document gathers the transparencies that were presented at the workshop.

  7. Probing of complete and incomplete fusion dynamics in heavy-ion ...

    Indian Academy of Sciences (India)

    2014-04-04

    Apr 4, 2014 ... Heavy-ion induced reactions; complete and incomplete fusion; excitation functions; forward recoil range ... CF reaction the projectile completely fuses with the target nucleus and the highly excited compund nucleus .... higher charge precursor isobars 176W and 173Ta have been separated to obtain their.

  8. Light charged particle emission in heavy-ion reactions–What have ...

    Indian Academy of Sciences (India)

    Light charged particles emitted in heavy-ion induced reactions, their spectra and angular distributions measured over a range of energies, carry the signature of the underlying reaction mechanisms. Analysis of data of light charged particles, both inclusive and exclusive measured in coincidence with gamma rays, fission ...

  9. Evolving theoretical descriptions of heavy-ion fusion: from phenomenological to microscopic approaches

    Directory of Open Access Journals (Sweden)

    Hagino K.

    2017-01-01

    Full Text Available We overview the current status of theoretical approaches for heavy-ion fusion reactions at subbarrier energies. We particularly discuss theoretical challenges in the coupled-channels approach, that include i a description of deep subbarrier hindrance of fusion cross sections, ii the role of nuclear dissipation, iii fusion of unstable nuclei, and iv an interplay between fusion and multi-nucleon transfer processes. We also present results of a semi-microscopic approach to heavy-ion fusion reactions, that combines the coupled-channels approach with state-of-the-art microscopic nuclear structure calculations.

  10. Jet Physics in Heavy Ion Collisions

    Science.gov (United States)

    Salur, Sevil

    2017-09-01

    Jet studies in heavy ion collisions have 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. In this talk, with an emphasis on experimental results from LHC, we will discuss the latest developments of jet finding techniques and their applications on new jet structure observables in heavy ion environments. These new measurements could be used to differentiate whether the medium affects the jet formation process from the hard process through hadronization, or whether the parton loses energy to the medium with the showers only affected at much later stages.

  11. The future of heavy ion radiotherapy.

    Science.gov (United States)

    Jäkel, Oliver; Karger, Christian P; Debus, Jürgen

    2008-12-01

    Currently, there is an increasing interest in heavy ion radiotherapy (RT) and a number of new facilities are being installed in Europe and Japan. This development is accompanied by intensive technical, physical, and clinical research. The authors identify six research fields where progress is likely and propose a thesis on the expected achievements for each of the fields: (1) Synchrotrons with active energy variation and three-dimensional beam scanning will be the standard in ion beam RT. (2) Common standards for precise measurement, prescription, and reporting of dose will be available. (3) Intensity-modulated particle therapy will be state-of-the-art. (4) Time-adaptive treatments of moving targets will be feasible. (5) Therapeutic effectiveness of heavy ions will be known for the most important indications while cost effectiveness will remain to be shown. (6) The potential of high-linear energy transfer radiation will be known. The rationale for each of these theses is described.

  12. The holifield heavy ion research facility

    Science.gov (United States)

    Jones, C. M.; Alton, G. D.; Ball, J. B.; Biggerstaff, J. A.; Dowling, D. T.; Erb, K. A.; Haynes, D. L.; Hoglund, D. E.; Hudson, E. D.; Juras, R. C.; Lane, S. N.; Ludemann, C. A.; Martin, J. A.; Mosko, S. W.; Olsen, D. K.; Richardson, E. G.; Stelson, P. H.; Ziegler, N. F.

    1986-02-01

    The Holifield Heavy Ion Research Facility has been in routine operation since July 1982. Beams have been provided using both the tandem accelerator alone and a coupled mode in which the Oak Ridge Isochronous Cyclotron is used as an energy booster for tandem beams. The coupled mode has proved to be especially effective and has allowed us to provide a wide range of energetic beams for scheduled experiments. In this report we discuss our operational experience and recent development activities.

  13. The heavy-ion magnetic spectrometer PRISMA

    Energy Technology Data Exchange (ETDEWEB)

    Stefanini, A.M. E-mail: alberto.stefanini@lnl.infn.it; Corradi, L.; Maron, G.; Pisent, A.; Trotta, M.; Vinodkumar, A.M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Segato, G.F.; De Rosa, A.; Inglima, G.; Pierroutsakou, D.; Romoli, M.; Sandoli, M.; Pollarolo, G.; Latina, A

    2002-04-22

    PRISMA is a magnetic spectrometer for heavy ions under construction at Legnaro, with very large solid angle (80 msr), wide momentum acceptance ({+-} 10%) and good mass resolution via TOF measurement; it will be dedicated to the study of nuclear dynamics and nuclear structure with stable and exotic ion beams. This is a review of its main features and of the present status of the project.

  14. Recent ATLAS Heavy Ion results

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Lead nucleus collisions in the LHC recreate the state of matter which existed when the universe was a few microseconds old. This super-hot matter, composed of quark and gluons, emits thousands of particles as it expands, cools and converts back into hadrons. The ATLAS detector provides an excellent opportunity to perform detailed studies of this novel state of matter, measuring its bulk properties and its response to penetrating probes. Recent studies of particle correlations and fluctuations shed light on the initial geometry and its evolution into the final state. Studies of jet suppression and fragmentation show how the energetic partons interact with the medium. High precision measurements of boson production and first results on boson-jet correlations are important steps towards quantitative understanding of the parton energy loss mechanism.

  15. Heavy Ion Physics with the ATLAS Detector

    CERN Multimedia

    Takai, H

    2003-01-01

    I guess the first thing that comes to people's mind is why is an experiment such as ATLAS interested in heavy ion physics. What is heavy ion physics anyway? The term heavy ion physics refers to the study of collisions between large nuclei such as lead, atomic number 208. But why would someone collide something as large and extensive as lead nuclei? When two nuclei collide there is a unique opportunity to study QCD at extreme energy densities. This said why do we think ATLAS is a good detector to study this particular physics? Among many of the simultaneous collisions that takes place when two nuclei encouter, hard scattering takes place. The unique situation now is that before hadronization partons from hard scattering may feel the surrounding media serving as an ideal probe for the matter formed in these collisions. As a consequence of this, jets may be quenched and their properties, e.g. fragmentation function or cone radius, modified when compared to proton-proton collisions. This is precisely where ATL...

  16. Dilepton radiation and bulk viscosity in heavy-ion collisions

    Science.gov (United States)

    Vujanovic, Gojko; Paquet, Jean-François; Shen, Chun; Denicol, Gabriel S.; Jeon, Sangyong; Gale, Charles; Heinz, Ulrich

    2017-08-01

    Starting from IP-Glasma initial conditions, we investigate the effects of bulk pressure on thermal dilepton production at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) energies. Though results of the thermal dilepton v2 under the influence of both bulk and shear viscosity is presented for top RHIC energy, more emphasis is put on LHC energy where such a calculation is computed for the first time. The effects of the bulk pressure on thermal dilepton v2 at the LHC are explored through bulk-induced modifications on the dilepton yield.

  17. Dynamical description of heavy-ion collisions at Fermi energies

    Directory of Open Access Journals (Sweden)

    Napolitani P.

    2016-01-01

    Full Text Available Descriptions of heavy-ion collisions at Fermi energies require to take into account in-medium dissipation and phase-space fluctuations. The interplay of these correlations with the one-body collective behaviour determines the properties (kinematics and fragment production and the variety of mechanisms (from fusion to neck formation and multifragmentation of the exit channel. Starting from fundamental concepts tested on nuclear matter, we build up a microscopic description which addresses finite systems and applies to experimental observables.

  18. The phi-meson and Chiral-mass-meson production in heavy-ion collisions as potential probes of quark-gluon-plasma and Chiral symmetry transitions

    Science.gov (United States)

    Takahashi, Y.; Eby, P. B.

    1985-01-01

    Possibilities of observing abundances of phi mesons and narrow hadronic pairs, as results of QGP and Chiral transitions, are considered for nucleus-nucleus interactions. Kinematical requirements in forming close pairs are satisfied in K+K decays of S(975) and delta (980) mesons with small phi, and phi (91020) mesons with large PT, and in pi-pi decays of familiar resonance mesons only in a partially restored chiral symmetry. Gluon-gluon dominance in QGP can enhance phi meson production. High hadronization rates of primordial resonance mesons which form narrow hadronic pairs are not implausible. Past cosmic ray evidences of anomalous phi production and narrow pair abundances are considered.

  19. Dynamic processes in heavy-ion collisions at intermediate energies

    Science.gov (United States)

    Prendergast, E. P.

    1999-03-01

    This thesis describes the study of the reaction dynamics in heavy-ion collisions of small nuclear systems at intermediate energies. For this, experiments were performed of 24Mg+27A1 at 45 and 95 AMeV. The experiments described in this thesis were performed at the GANIL accelerator facility in Caeri (France) using the Huygens detectors in conjunction with the ‘MUR’. The Huygens detectors consist of the CsI(Tl)-Wall (CIW) covering the backward hemisphere and, located at mid-rapidity, the central trigger detector (CTD), a gas chamber with microstrip read-out backed by 48 plastic scintillators. The forward region is covered by 16 of the plastic scintillators of the CTD and by the MUR, a time-of-flight wall consisting of 96 plastic scintillator sheets. In earlier experiments only fragments with atomic number, Z, greater then two could be identifled in the CTD. Therefore, an investigation was done into the properties of different drift gases. The use of freon (CF4) in the drift chamber, combined with an increase of the gas pressure to 150 mbar, makes it possible to identify all particles with Z ≥ 2. Under these conditions particles with Z = 1 can only be identifled to approximately 25 AMeV. The Isospin Quantum Molecular Dynamics (IQMD) model has been used, to interpret the measured data. This model gives a microscopical description of heavy-ion collisions and simulates collisions on an event by event basis. In IQMD all protons and neutrons are represented as individual Gaussian wave packets. After initialisation the path of each nucleon is calculated for 200 fm/c, after which the simulation is stopped. At this time, nucleons which are close in space are clustered into fragments. The events generated by IQMD can then be processed by a GEANT detector simulation. This calculation takes into account the effects of the detector on the incoming particles. By using the GEANT simulation it is possible to give a direct comparison between the results of IQMD and the

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Heavy ion physics at LHC with CMS detector

    CERN Document Server

    Kvatadze, R A

    1997-01-01

    The CMS ( Compact Muon Solenoid) is a general purpose detector, optimised for p-p collisions at LHC. However, a very good muon system, fine granularity and excellent energy resolution of electromagnetic and hadron calorimeters and high quality central tracker gives the possibility of using the detector for specific heavy ion studies. Various ways of searching for the phase transition from hadronic matter to the plasma of deconfined quarks and gluons ( QGP) in heavy ion collisions with CMS detector have been investigated: Production of ( bb) and ( cc) resonant states through their muon decay channel to study the colour-screening effect. The dimuon mass spectra and rates of heavy quark bound state production for two weeks of running time are presented. Expected statistics will be sufficient to perfom the Upsilon family suppression study. Detection of J/Psi is mostly concentrated in the forwa rd region. Z production and its subsequent mu+mu- decay can be detected with high statistics and very low background ( 4%...

  2. Emission of fragments in heavy ion-collisions at Fermi energy; Modes de production des fragments dans les collisions d'ions lourds aux energies intermediaires

    Energy Technology Data Exchange (ETDEWEB)

    Normand, J

    2001-10-01

    The study of reaction mechanisms in Fermi energy domain has shown the dominant binary character of the process. The two heavy sources produced after the first stage of the interaction (the quasi-projectile QP and the quasi-target QT) can experience various decay modes from evaporation to multifragmentation. However, the presence of light fragments at mid rapidity cannot be explained by the standard decay of the QP and the QT. To understand the mechanisms producing such a contribution, the break-up of the QP has been studied on the following systems: Xe+Sn from 25 to 50 MeV/A, Ta+Au and Ta+U at 33, 39.6 MeV/A and U+U at 24 MeV/A. The experiment has been performed at GANIL with the INDRA multidetector. The particular behaviour of the heaviest fragment and the correlation between the charge and the velocity of the fragments suggest a shape deformation followed by the rupture of a neck formed in between the two partners of the collision. The heaviest fragment could be the reminiscence of the projectile. A method based on the angular distribution of the heaviest fragment has allowed to separate the statistical break-up of the QP and the non equilibrated break-up. The statistical break-up ranges from 30 % to 75 % of the break-ups. The comparison of the statistical component with a statistical model gives information about the charge, the angular momentum and the temperature of the QP. The comparison of the non equilibrated component with dynamical models could give information about the parameters of the nuclear interaction in medium. (author)

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

    Science.gov (United States)

    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.

  4. Search for nuclei in heavy ion collisions at ultrarelativistic energies

    CERN Multimedia

    2002-01-01

    We would like to know if nuclei are still present after a collision of two heavy ions at ultrarelativistic energies. If one can detect some of them at large angle $(>10^{\\circ}-15^{\\circ})$ they very likely come from a multifragmentation of the excited target spectators. Such a multifragmentation in several nuclei has been in proton induced reactions at Fermilab and it was interpreted as a gas-liquid phase transition in nuclei matter near the critical point. With heavy ions the energy deposited in the target spectators will be much higher than in the case of protons and a different mechanism should be involved if nuclei are still observed. \\\\ \\\\ We propose to detect nuclei using 1-2 silicon telescopes and a 1-2mg/cm$^{2}$ Au target bombarded by an $^{16}$O or $^{32}$S beam at 226 GeV/u. The set-up will be installed in a small cube located just before the NA38 experiment and should not perturb it.\\\\ \\\\ Data from $^{16}$O incident on Au have been taken last year. The experiment is presently taking data with $^{...

  5. Production of partons in the presence of classical fields in ultrarelativistic heavy-ion collisions; Produktion von Patronen in Anwesenheit klassischer Felder in ultrarelativistischen Schwerionenkollisionen

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, D.D

    2003-09-01

    In this work the production of quarks, antiquarks and of gluonic fluctuations is studied in the presence of classical bosonic field. A comparison of the production of anti-quark pairs with the creation of pairs of gluonic quantum fluctuations based on perturbative calculations will be presented here. This analysis is valid for quantum particles with a large momentum compared to the magnitude of the classical vector potential multiplied by the coupling constant. The model contains 3 parameters: the initial magnitude of the gauge field, the coupling constant and the time scale on which the field decays. It appears that none of the species (quark-antiquark pairs, gluonic fluctuation pairs, bosons and fermion-anti fermions) can be neglected from the beginning. A corresponding calculation requires a non-perturbative description of at least the soft fermions. In this thesis the exact expression for fields varying arbitrarily in time is derived. After the full solution has been obtained, various approximation schemes are proposed for different domains, in order to find out into which the situation under consideration falls. There are approximations in the ultraviolet (perturbative), the infrared, and the Abelian (commutative) regime. The exact expression and the lowest orders of the different approximation schemes are evaluated in the presence of the model field with the same parameters as before. (A.C.)

  6. Evaluation of excitation energy and spin from light charged particles multiplicities in heavy-ion collisions

    CERN Document Server

    Steckmeyer, J C; Grotowski, K; Pawowski, P; Aiello, S; Anzalone, A; Bini, M; Borderie, B; Bougault, R; Cardella, G; Casini, G; Cavallaro, S; Charvet, J L; Dayras, R; De Filippo, E; Durand, D; Femin, S; Frankland, J D; Galíchet, E; Geraci, M; Giustolisi, F; Guazzoni, P; Iacono-Manno, M; Lanzalone, G; Lanzan, G; Le Neindre, N; Lo Nigro, S; Lo Piano, F; Olmi, A; Pagano, A; Papa, M; Pârlog, M; Pasquali, G; Piantelli, S; Pirrone, S; Politi, G; Porto, F; Rivet, M F; Rizzo, F; Rosato, E; Roy, R; Sambataro, S; Sperduto, M L; Stefanini, A A; Sutera, C; Tamain, B; Vient, E; Volant, C; Wieleczko, J P; Zetta, L

    2005-01-01

    A simple procedure for evaluating the excitation energy and the spin transfer in heavy-ion dissipative collisions is proposed. It is based on a prediction of the GEMINI evaporation code : for a nucleus with a given excitation energy, the average number of emitted protons decreases with increasing spin, whereas the average number of alpha particles increases. Using that procedure for the reaction 107Ag+58Ni at 52 MeV/nucleon, the excitation energy and spin of quasi-projectiles have been evaluated. The results obtained in this way have been compared with the predictions of a model describing the primary dynamic stage of heavy-ion collisions.

  7. Studying Heavy Ion Collisions Using Methods From Cosmic Microwave Background (CMB Analysis

    Directory of Open Access Journals (Sweden)

    Gaardhøje J. J.

    2014-04-01

    Full Text Available We present and discuss a framework for studying the morphology of high-multiplicity events from relativistic heavy ion collisions using methods commonly employed in the analysis of the photons from the Cosmic Microwave Background (CMB. The analysis is based on the decomposition of the distribution of the number density of (charged particles expressed in polar and azimuthal coordinates into a sum of spherical harmonic functions. We present an application of the method exploting relevant symmetries to the study of azimuthal correlations arizing from collective flow among charged particles produced in relativistic heavy ion collisions. We discuss perspectives for event-by- event analyses, which with increasing collision energy will eventually open entirely new dimensions in the study of ultrarelaticistic heavy ion reactions.

  8. Three-nucleon interaction in heavy-ion collisions at intermediate energies

    Science.gov (United States)

    Wada, R.

    2017-09-01

    The effect of a three-nucleon (3 N ) interaction is studied for the production of high energy protons in heavy-ion collisions in the incident energy range of 44 to 400 A MeV . The 3 N interaction is incorporated into the antisymmetrized molecular dynamics transport model of Ono [A. Ono, Phys. Rev. C 59, 853 (1999), 10.1103/PhysRevC.59.853] as a 3 N collision term, following a diagram of three consecutive binary collisions. For the theoretical 40Ar+51V reaction studies, no contribution from the 3 N collisions is observed for high energy proton production at the incident energy of 44 A MeV . However when the incident energy increases, the contribution increases gradually. At 200 A MeV and above, the contribution is observed as distinctly harder energy slopes in the proton energy spectra. The model is applied to the available Bevalac data for 40Ar+40Ca at 42 ,92 , and 137 A MeV . The experimental proton energy spectra are reasonably well reproduced at angles θ ≥70∘ for all three incident energies, showing negligible 3 N contributions at 42 A MeV and significant contributions at 137 A MeV at the large laboratory angles. Good agreement at these large angles, where the 3 N collision is a major mechanism to produce such protons, strongly indicates for the first time the importance of the 3 N interaction in intermediate heavy ion reactions in a full transport calculation. The possible relation between the 3 N collision term and the short range and the tensor interactions is suggested.

  9. State density formalism of the Iwamoto-Harada model: A suitable tool to treat cluster emission from heavy-ion collisions with account for spin variables

    Directory of Open Access Journals (Sweden)

    Běták Emil

    2017-01-01

    Full Text Available We study the possibility to include the cluster emission into the statistical pre-equilibrium (exciton model suitable also for heavy ion collisions. The direct motivation of this paper is a possibility of producing superdeformed nuclei, which are easier to be detected in heavy-ion reactions than in those induced by light projectiles (nucleons, deuterons, α-particles.

  10. Glenn T. Seaborg and heavy ion nuclear science

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  11. Glenn T. Seaborg and heavy ion nuclear science

    Energy Technology Data Exchange (ETDEWEB)

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

    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. Direct photons in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Baeuchle, Bjoern

    2010-12-13

    Direct photon emission from heavy-ion collisions has been calculated and compared to available experimental data. Three different models have been combined to extract direct photons from different environments in a heavy-ion collision: Thermal photons from partonic and hadronic matter have been extracted from relativistic, non-viscous 3+1-dimensional hydrodynamic calculations. Thermal and non-thermal photons from hadronic interactions have been calculated from relativistic transport theory. The impact of different physics assumptions about the thermalized matter has been studied. The models used for the determination of photons from both hydrodynamic and transport calculations have been elucidated and their numerical properties tested. The origin of direct photons, itemised by emission stage, emission time, channel and baryon number density, has been investigated for various systems, as have the transverse momentum spectra and elliptic flow patterns of direct photons. Taking into account the full (vacuum) spectral function of the rho-meson decreases the direct photon emission by approximately 10% at low photon transverse momentum. In all systems that have been considered -- heavy-ion collisions at E{sub lab}=35 AGeV and 158 AGeV, (s{sub NN}){sup 1/2}=62.4 GeV, 130 GeV and 200 GeV -- thermal emission from a system with partonic degrees of freedom is greatly enhanced over that from hadronic systems, while the difference between the direct photon yields from a viscous and a non-viscous hadronic system (transport vs. hydrodynamics) is found to be very small. Predictions for direct photon emission in central U+U-collisions at 35 AGeV have been made. (orig.)

  13. Energy and system size dependence of {xi}{sup -} and anti {xi}{sup +} production in relativistic heavy-ion collisions at the CERN SPS

    Energy Technology Data Exchange (ETDEWEB)

    Mitrovski, M.K.

    2007-11-21

    The strong nuclear force is described by Quantum Chromodynamics (QCD), the parallel field theory to Quantum Electrodynamics (QED) that describes the electromagnetic force. It is propagated by gluons analogously to photons in the electromagnetic force, but unlike photons, which do not carry electric charge, gluons carry color, and they can self-interact. However, as individual quarks have never been observed in nature, it is postulated that the color charge itself is confined, and hence all baryons and mesons must be colorless objects. To study nuclear matter under extreme conditions, it is necessary to create hot and dense nuclear matter in the laboratory. In such conditions the confinement between quarks and gluons is cancelled (deconfinement). This state is characterized with a quasi-free behavior of quarks and gluons. The strange (s) and anti-strange (anti-s) quarks are not contained in the colliding nuclei, but are newly produced and show up in the strange hadrons in the final state. It was suggested that strange particle production is enhanced in the QGP with respect to that in a hadron gas. This enhancement is relative to a collision where a transition to a QGP phase does not take place, such as p+p collisions where the system size is very small. Therefore the energy- and system size dependence is studied to receive a picture about the initial state. In this thesis experimental results on the energy- and system size dependence of Xi hyperon production at the CERN SPS is shown. All measurements were performed with the NA49 detector at the CERN SPS. NA49 took central lead-lead collisions from 20 - 158 AGeV, minimus bias lead-lead collisions at 40 and 158 AGeV, and semi-central silicon-silicon collisions at 158 AGeV. The NA49 experiment features a large acceptance in the forward hemisphere allowing for measurements of Xi rapidity spectra. At the SPS accelerator at CERN Pb+Pb collisions are performed with beam energies to 158 AGeV. The analyzed data sets were

  14. Hyperons polarization in heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Baznat Mircea

    2017-01-01

    Full Text Available We study the structure of vorticity and hydrodynamic helicity fields in peripheral heavy-ion collisions using the kinetic Quark-Gluon Strings Model. The angular momentum which is a source of P-odd observables is preserved within this model with a good accuracy. We observe the formation of specific toroidal structures of vorticity field. Their existence is mirrored in the polarization of hyperons of the percent order. The observed qualitative energy dependence of polarization was predicted earlier and is quantified now.

  15. Heavy Ions in 2011 and beyond

    CERN Document Server

    Jowett, J; Bruce, R; Carli, C; Manglunki, D; Mertens, T; Wollmann, D

    2011-01-01

    The LHC's first heavy ion run set - and tested - the operational pattern for 2011 and later years: a rapid commissioning strategy intended to ensure delivery of integrated luminosity despite the risks associated with the short time-frame. It also gave us hard data to test our understanding of the beam physics that will limit performance. The 2010 experience is fed into the commissioning plan, parameter choices and projected performance for 2011. The prospects for future stages of the LHC ion program, Pb-Pb collisions at higher energy and luminosity, hybrid collisions and other species, depend critically on the scheduling of certain hardware upgrades.

  16. Progress in understanding heavy-ion stopping

    Energy Technology Data Exchange (ETDEWEB)

    Sigmund, P., E-mail: sigmund@sdu.dk [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark); Schinner, A. [Institut für Experimentalphysik, Johannes Kepler Universität, A-4040 Linz (Austria)

    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. Deep Subthreshold Ξ- Production in Ar+KCl Reactions at 1.76AGeV

    Science.gov (United States)

    Agakishiev, G.; Balanda, A.; Bassini, R.; Belver, D.; Belyaev, A. V.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Fabbietti, L.; Fateev, O. V.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; González-Díaz, D.; Guber, F.; Hennino, T.; Holzmann, R.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krizek, F.; Krücken, R.; Kühn, W.; Kugler, A.; Kurepin, A.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Sudol, M.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Weber, M.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y. V.; Zhou, P.; Zumbruch, P.

    2009-09-01

    We report first results on a deep subthreshold production of the doubly strange hyperon Ξ- in a heavy-ion reaction. At a beam energy of 1.76AGeV the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Λ sample was collected, allowing for the investigation of the decay channel Ξ-→Λπ-. The deduced Ξ-/(Λ+Σ0) production ratio of (5.6±1.2-1.7+1.8)×10-3 is significantly larger than available model predictions.

  18. Energy of vanishing flow in heavy-ion collisions: Role of mass ...

    Indian Academy of Sciences (India)

    Energy of vanishing flow in heavy-ion collisions: Role of mass asymmetry of a reaction. VARINDERJIT KAUR and SUNEEL KUMAR. ∗. School of Physics and Material Science, Thapar University, Patiala 147 004, India. ∗. Corresponding author. E-mail: suneel.kumar@thapar.edu. MS received 28 April 2011; revised 4 July ...

  19. Fusion-Fission process and gamma spectroscopy of binary products in light heavy ion collisions (40 {<=} A{sub CN} {<=} 60); Processus de fusion-fission et spectroscopie gamma des produits binaires dans les collisions entre ions lourds legers (40 {<=} A{sub NC} {<=} 60)

    Energy Technology Data Exchange (ETDEWEB)

    Nouicer, Rachid [Institut de Recherche Subatomique, CNRS-IN2P3 - Universite Louis Pasteur, 67 - Strasbourg (France)

    1997-11-21

    During the work on which this Thesis is based, the significant role of the Fusion-Fission Asymmetric mechanism in light heavy ion collisions (A{sub NC} {<=} 60) has been emphasized. The Spin Dis-alignment in the oblate-oblate system has supplied evidence for the first time for the Butterfly mode in a resonant-like reaction. These two aspects, one macroscopic and the other more closely related to microscopic effects are certainly different from a conceptual point of view but are quite complementary for a global understanding of dinuclear systems. In the first part, inclusive and exclusive measurements of the {sup 35}Cl + {sup 12}C and {sup 35}Cl + {sup 24}Mg reaction have been performed at 8 MeV/nucleon in the Saclay experiment. These measurements have permitted us to verify the origin of products which have given rise of the asymmetric fusion-fission mechanism and which have demonstrated that the three-body process in this energy range is very weak. In the second part the {sup 28}Si + {sup 28}Si reaction has been performed at the resonance energy E{sub lab}> = 111.6 MeV at Strasbourg with the Eurogam phase II multi-detector array and VIVITRON accelerator. An angular momentum J{sup {pi}} 38{sup +} for inelastic and mutual channels of the {sup 28}Si + {sup 28}Si exit channel has been measured and has supplied evidence for a spin dis-alignment which has been interpreted in the framework of a molecular model by Butterfly motion. The spectroscopic study of {sup 32}S nucleus, has revealed the occurrence of a new {gamma}-ray transition 0{sup +}(8507.8 keV) {yields} 2{sub 1}{sup +}(2230.2 keV). (author) 105 refs., 116 figs., 26 tabs.

  20. QCD and Heavy Ions RHIC Overview

    CERN Document Server

    Granier de Cassagnac, Raphael

    2010-01-01

    Nowadays, the most violent heavy ion collisions available to experimental study occur at the Relativistic Heavy Ion Collider (RHIC) of the Brookhaven National Laboratory. There, gold ions collide at psNN = 200 GeV. The early and most striking RHIC results were summarised in 2005 by its four experiments, BRAHMS, PHENIX, PHOBOS and STAR, in their so-called white papers [1, 2, 3, 4] that will be largely referenced thereafter. Beyond and after this, a wealth of data has been collected and analysed, providing additional information about the properties of the matter created at RHIC. It is categorically impossible to give a comprehensive review of these results in a 20 minutes talk or a 7 pages report. Here, I have made a selection of some of the most striking or intriguing signatures: jet quenching in Section 2, quarkonia suppressions in Section 3 and thermal photons in Section 4. A slightly longer and older version of this review can be found in [5]. Some updates are given here, as well as emphasis on new probes ...

  1. A high energy, heavy ion microprobe for ion beam research on the tandem accelerator at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, D.D.; Siegele, R.; Dytlewski, N.

    1996-04-01

    A comprehensive review is given on the production and use of heavy ion beams with spot sizes of a few {mu}m. The development of a high energy, heavy ion microprobe at ANSTO and its possible applications are discussed. The microprobe is designed to focus a wide range of ion beam types, from light ions such as protons up to ions as heavy as iodine. Details of the ion beam optics, optical calculations and a description of the proposed microbeam design are given. The unique combination of high energy, heavy ions and improved detection systems will provide high sensitivity elemental composition and depth profiling information, allowing surface topography and 3D surface reconstruction to be performed on a broad range of materials. 86 refs., 5 tabs., 15 figs.

  2. Femtoscopic analysis of baryon correlations in ultra-relativistic heavy-ion collisions registered by ALICE

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00361630

    Heavy-ion collisions at ultra-relativistic energies give a unique possibility to create and to analyse the Quark-Gluon Plasma predicted by the theory of Quantum Chromodynamics. The research on the properties of such state of matter is crucial for understanding the features of the strongly interacting system. Experimental results reveal the collective behaviour of matter created in the heavy-ion collisions at ultra-relativistic energies. The existence of this effect can be verified by the measurement of the transverse mass dependence of the source size extracted using different particle species. Such characteristics can be determined using the analysis technique called femtoscopy. This method is based on the correlations of particles with small relative momenta which originate from the effects of Quantum Statistics as well as the strong and Coulomb Final State Interactions. A recent analysis of the particle production at the highest available collision energies of heavy-ion collisions reveals the puzzling res...

  3. The time-of-flight spectrometer for heavy ions PISOLO

    Energy Technology Data Exchange (ETDEWEB)

    Montagnoli, G. E-mail: montagnoli@pd.infn.it; Scarlassara, F.; Beghini, S.; Dal Bello, A.; Segato, G.F.; Stefanini, A.M.; Ackermann, D.; Corradi, L.; He, J.H.; Lin, C.J

    2000-11-11

    A time-of-flight spectrometer with magnetic focusing has been installed at the Laboratori Nazionali di Legnaro. The spectrometer's length is 3.6 m and allows for high-resolution time-of-flight measurements. Magnetic focusing is accomplished by two quadrupole doublets. The spectrometer is connected to a sliding seal scattering chamber rotating over a large angular range. Micro channel-plate detectors for start/stop signals and an ionization chamber for {delta}E-E measurements at the focal plane, are used. The setup provides a maximum effective solid angle {delta}{omega}=2.8 msr, and is dedicated to the study of quasi-elastic reactions between heavy ions; in particular, it has already been used to investigate near-barrier multi-nucleon transfer processes.

  4. Nuclear Fragmentation in Clinical Heavy Ion Beams, Should We Worry?

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, David Christoffer; Toftegaard, Jakob

    particles is formed beyond the Bragg-peak. This tail may deliver unwanted dose to normal tissue, however the magnitude of the tail is directly depending on the inelastic nuclear reaction cross sections. 2. Dosimetry a. Stopping power ratios: Routine dosimetry is performed with air-filled ionization chambers...... the sensitivity on the three fields mentioned above, including: turning off nuclear fragmentation entirely, changing all ineleastic cross sections +/- 20%, changing key parameters in the Fermi-Breakup (FB) model. Results show nuclear effects have their largest impact on the dose distribution. Stopping power......Particle therapy with fast ions is increasingly applied as a treatment option for localized inoperable tumour sites. One of the reasons for the increased complications of understanding heavy ion dosimetry and radiobiology stems from the mixed particle spectrum which occurs due to nuclear...

  5. Hard Probes in Heavy-Ion Physics

    CERN Document Server

    Renk, Thorsten

    2012-01-01

    The aim of ultrarelativistic heavy ion physics is to study collectivity and thermodynamics of Quantum Chromodynamics (QCD) by creating a transient small volume of matter with extreme density and temperature. There is experimental evidence that most of the particles created in such a collision form indeed a thermalized system characterized by collective response to pressure gradients. However, a numerically small subset of high transverse momentum ($P_T$) processes takes place independent of the bulk, with the outgoing partons subsequently propagating through the bulk medium. Understanding the modification of such 'hard probes' by the bulk medium is an important part of the efforts to determine the properties of hot and dense QCD matter. In this paper, current developments are reviewed.

  6. Application of hydrodynamics to heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Felsberger, Lukas

    2014-12-02

    The Bjorken model is a simple tool for making rough predictions of the hydrodynamic evolution of the thermalized matter created in a heavy ion collision. The advantage of the model clearly lies in its simplicity, rather than accuracy. As it is still used for making rough estimations 'by hand', in this thesis, I investigate in which cases the Bjorken model gives useful results and in which it is not recommended. For central collisions, I show which critical size the nuclei should have so that the Bjorken model can be applied. For non-central collisions, I demonstrate that using Glauber initial conditions combined with the Bjorken evolution, leads to reasonable results up to large impact parameters. Finally, I study the case of a non-ideal (viscous) description of the thermalized matter which leads to strongly differing results if first- or second-order hydrodynamics is applied.

  7. Heavy Ion results from RHIC-BNL

    Directory of Open Access Journals (Sweden)

    Esumi Shinlchi

    2013-05-01

    Full Text Available Recent results from heavy ion collision experiments from RHIC at BNL are presented and discussed in terms of Quark Gluon Plasm properties, such as partonic collectivity and partonic energy loss. The experimental results with direct photons and heavy quarks have given important additional insights of the plasma on top of what has been known with light hadrons. Higher order event anisotropies and the related results have provided the geometrical, temporal and dynamical information of the plasma. The beam energy dependence of the various measurements could reveal the structure of QCD phase diagram and possibly the critical point in the diagram, where the properties of phase transition are expected to change drastically.

  8. Statistics of heavy-ion stopping

    CERN Document Server

    Glazov, L G; Schinner, A

    2002-01-01

    Energy-loss straggling of swift heavy ions penetrating through matter has been analysed on the basis of binary stopping theory as well as the modified Bohr model allowing for projectile screening. A program has been written which evaluates the generalized Bothe-Landau formula governing the energy-loss spectrum for penetration through a thin layer, allowing for charge exchange involving an arbitrary number of charge states. This program was generated on the basis of calculational schemes developed originally for swift light ions. Projectile screening and multiple-shell structure of target atoms are allowed for. Explicit energy-loss spectra are given for oxygen in carbon for charge states 6-8 and foil thickness 2, 10 and 50 mu g/cm sup 2. It is also demonstrated that frozen-charge straggling depends only weakly on charge state.

  9. Heavy ion Physics with the ATLAS Detector

    CERN Document Server

    White, S N

    2006-01-01

    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 ?sNN = 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.

  10. Electromagnetic probes in heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    van Hees H.

    2015-01-01

    Full Text Available Due to their penetrating nature, electromagnetic probes, i.e., lepton-antilepton pairs (dileptons and photons are unique tools to gain insight into the nature of the hot and dense medium of strongly-interacting particles created in relativistic heavy-ion collisions, including hints to the nature of the restoration of chiral symmetry of QCD. Of particular interest are the spectral properties of the electromagnetic current-correlation function of these particles within the dense and/or hot medium. The related theoretical investigations of the in-medium properties of the involved particles in both the partonic and hadronic part of the QCD phase diagram underline the importance of a proper understanding of the properties of various hadron resonances in the medium.

  11. Highlights from STAR heavy ion program

    Science.gov (United States)

    Okorokov, Vitalii

    2017-10-01

    Recent experimental results obtained in STAR experiment at the Relativistic heavy-ion collider (RHIC) with ion beams will be discussed. Investigations of different nuclear collisions in some recent years focus on two main tasks, namely, detail study of quark-gluon matter properties and exploration of the quantum chromodynamics (QCD) phase diagram. Results at top RHIC energy show clearly the collective behavior of heavy quarks in nucleus-nucleus interactions. Jet and heavy hadron measurements lead to new constraints for energy loss models for various flavors. Heavy-ion collisions are unique tool for the study of topological properties of theory as well as the magneto-hydrodynamics of strongly interacting matter. Experimental results obtained for discrete QCD symmetries at finite temperatures confirm indirectly the topologically non-trivial structure of QCD vacuum. Finite global vorticity observed in non-central Au+Au collisions can be considered as important signature for presence of various chiral effects in sQGP. Most results obtained during stage I of the RHIC beam energy scan (BES) program show smooth behavior vs initial energy. However certain results suggest the transition in the domain of dominance of hadronic degrees of freedom at center-of-mass energies between 10-20 GeV. The stage II of the BES at RHIC will occur in 2019-2020 and will explore with precision measurements in the domain of the QCD phase diagram with high baryon densities. Future developments and more precise studies of features of QCD phase diagram in the framework of stage II of RHIC BES will be briefly discussed.

  12. Basic atomic interactions of accelerated heavy ions in matter atomic interactions of heavy ions

    CERN Document Server

    Tolstikhina, Inga; Winckler, Nicolas; Shevelko, Viacheslav

    2018-01-01

    This book provides an overview of the recent experimental and theoretical results on interactions of heavy ions with gaseous, solid and plasma targets from the perspective of atomic physics. The topics discussed comprise stopping power, multiple-electron loss and capture processes, equilibrium and non-equilibrium charge-state fractions in penetration of fast ion beams through matter including relativistic domain. It also addresses mean charge-states and equilibrium target thickness in ion-beam penetrations, isotope effects in low-energy electron capture, lifetimes of heavy ion beams, semi-empirical formulae for effective cross sections. The book is intended for researchers and graduate students working in atomic, plasma and accelerator physics.

  13. Transport models for relativistic heavy-ion collisions at Relativistic ...

    Indian Academy of Sciences (India)

    2015-04-29

    Apr 29, 2015 ... Transport models for relativistic heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider. Subrata Pal. Volume 84 Issue 5 May 2015 pp ... Subrata Pal1. Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India ...

  14. Heavy ions at the LHC: Physics perspectives and experimental ...

    Indian Academy of Sciences (India)

    Abstract. Ultrarelativistic heavy ion physics is entering the new era of collider experiments with the start-up of RHIC at BNL and construction for detectors at LHC well under way. At this crossroads, the article will give a summary of the experimental program and our current view of heavy ion physics at the LHC, concentrating ...

  15. Heavy ions: Results from the Large Hadron Collider

    Indian Academy of Sciences (India)

    The LHC worked exceedingly well during its one month of operation with heavy ions, delivering about 10 −1 of data, with peak luminosity reaching to L O = 2 × 10 25 cm-2 s-1 towards the end of the run. Three experiments, ALICE, ATLAS and CMS, recorded their first heavy-ion data, which were analysed in a record time.

  16. Theoretical Concepts for Ultra-Relativistic Heavy Ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. Structural and electrical properties of swift heavy ion beam irradiated ...

    Indian Academy of Sciences (India)

    Synthesis of swift heavy ion induced metal silicide is a new advancement in materials science research. We have investigated the mixing at Co/Si interface by swift heavy ion beam induced irradiation in the electronic stopping power regime. Irradiations were undertaken at room temperature using 120 MeV Au ions at the ...

  18. Diffusion kinetics of the glucose/glucose oxidase system in swift heavy ion track-based biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Dietmar, E-mail: fink@xanum.uam.mx [Nuclear Physics Institute, 25068 Řež (Czech Republic); Departamento de Fisica, Universidad Autónoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 México, DF (Mexico); Vacik, Jiri; Hnatowicz, V. [Nuclear Physics Institute, 25068 Řež (Czech Republic); Muñoz Hernandez, G. [Departamento de Fisica, Universidad Autónoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 México, DF (Mexico); Garcia Arrelano, H. [Departamento de Ciencias Ambientales, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Lerma, Av. de las Garzas No. 10, Col. El Panteón, Lerma de Villada, Municipio de Lerma, Estado de México CP 52005 (Mexico); Alfonta, Lital [Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105 (Israel); Kiv, Arik [Department of Materials Engineering, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105 (Israel)

    2017-05-01

    Highlights: • Application of swift heavy ion tracks in biosensing. • Obtaining yet unknown diffusion coefficients of organic matter across etched ion tracks. • Obtaining diffusion coefficients of organics in etched ion tracks of biosensors. • Comparison with Renkin’s equation to predict the effective etched track diameter in the given experiments. - Abstract: For understanding of the diffusion kinetics and their optimization in swift heavy ion track-based biosensors, recently a diffusion simulation was performed. This simulation aimed at yielding the degree of enrichment of the enzymatic reaction products in the highly confined space of the etched ion tracks. A bunch of curves was obtained for the description of such sensors that depend only on the ratio of the diffusion coefficient of the products to that of the analyte within the tracks. As hitherto none of these two diffusion coefficients is accurately known, the present work was undertaken. The results of this paper allow one to quantify the previous simulation and hence yield realistic predictions of glucose-based biosensors. At this occasion, also the influence of the etched track radius on the diffusion coefficients was measured and compared with earlier prediction.

  19. Optical model calculations of heavy-ion target fragmentation

    Science.gov (United States)

    Townsend, L. W.; Wilson, J. W.; Cucinotta, F. A.; Norbury, J. W.

    1986-01-01

    The fragmentation of target nuclei by relativistic protons and heavy ions is described within the context of a simple abrasion-ablation-final-state interaction model. Abrasion is described by a quantum mechanical formalism utilizing an optical model potential approximation. Nuclear charge distributions of the excited prefragments are calculated by both a hypergeometric distribution and a method based upon the zero-point oscillations of the giant dipole resonance. Excitation energies are estimated from the excess surface energy resulting from the abrasion process and the additional energy deposited by frictional spectator interactions of the abraded nucleons. The ablation probabilities are obtained from the EVA-3 computer program. Isotope production cross sections for the spallation of copper targets by relativistic protons and for the fragmenting of carbon targets by relativistic carbon, neon, and iron projectiles are calculated and compared with available experimental data.

  20. Time-of-flight detector for heavy ion backscattering spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, J.A.; Banks, J.C.; Doyle, B.L. [Sandia National Labs., Albuquerque, NM (United States). Ion Solid Interactions and Defect Physics Dept.

    1994-04-01

    This report describes the results of a two-year laboratory directed research and development project to explore advanced concepts in Heavy Ion Backscattering Spectrometry (HIBS), undertaken with the goal of extending the sensitivity of this relatively new technique to levels unattainable by any other existing trace element surface analysis. Improvements in sensitivity are required for the application of HIBS to contamination control in the microelectronics industry. Tools with sensitivity approaching 10{sup 8} atoms/cm{sup 2} are expected to be essential for enabling advanced IC production by the year 2000. During the project the authors developed a new analysis chamber with channeling goniometer and a prototype time-of-flight detector with a demonstrated sensitivity of {approximately} 5 {times} 10{sup 8} atoms/cm{sup 2} for Au on Si and {approximately} 5 {times} 10{sup 10} for Fe, and sufficient mass resolution to separate contributions from Fe and Cu.

  1. Chemical freeze-out in relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Jun Xu

    2017-09-01

    Full Text Available One surprising result in relativistic heavy-ion collisions is that the abundance of various particles measured in experiments is consistent with the picture that they reach chemical equilibrium at a temperature much higher than the temperature they freeze out kinetically. Using a multiphase transport model to study particle production in these collisions, we find, as an example, that the effective pion to nucleon ratio, which includes those from resonance decays, indeed changes very little during the evolution of the hadronic matter from the chemical to the kinetic freeze-out, and it is also accompanied by an almost constant specific entropy. We further use a hadron resonance gas model to illustrate the results from the transport model study.

  2. Jets and Vector Bosons in Heavy Ion Collisions

    Directory of Open Access Journals (Sweden)

    de la Cruz Begoña

    2013-11-01

    Full Text Available 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.

  3. Dissociation of biomolecules in liquid environments during fast heavy-ion irradiation

    Science.gov (United States)

    Nomura, Shinji; Tsuchida, Hidetsugu; Kajiwara, Akihiro; Yoshida, Shintaro; Majima, Takuya; Saito, Manabu

    2017-12-01

    The effect of aqueous environment on fast heavy-ion radiation damage of biomolecules was studied by comparative experiments using liquid- and gas-phase amino acid targets. Three types of amino acids with different chemical structures were used: glycine, proline, and hydroxyproline. Ion-induced reaction products were analyzed by time-of-flight secondary-ion mass spectrometry. The results showed that fragments from the amino acids resulting from the C—Cα bond cleavage were the major products for both types of targets. For liquid-phase targets, specific products originating from chemical reactions in solutions were observed. Interestingly, multiple dissociated atomic fragments were negligible for the liquid-phase targets. We found that the ratio of multifragment to total fragment ion yields was approximately half of that for gas-phase targets. This finding agreed with the results of other studies on biomolecular cluster targets. It is concluded that the suppression of molecular multifragmentation is caused by the energy dispersion to numerous water molecules surrounding the biomolecular solutes.

  4. Phenotypic spectrum of Parachlorella kessleri (Chlorophyta) mutants produced by heavy-ion irradiation.

    Science.gov (United States)

    Ota, Shuhei; Matsuda, Takahiro; Takeshita, Tsuyoshi; Yamazaki, Tomokazu; Kazama, Yusuke; Abe, Tomoko; Kawano, Shigeyuki

    2013-12-01

    Heavy-ion mutagenesis is a technology used for effective production of genetic mutants. This study demonstrates that algal breeding using a unicellular alga, Parachlorella kessleri, by heavy-ion mutagenesis can improve lipid yield in laboratory experiments. The primary screening yielded 23 mutants among which a secondary screening yielded 7 strains, which were subjected to phenotypic assays. P. kessleri strains produced by heavy-ion radiation spanned a broad spectrum of phenotypes that differed in lipid content and fatty acid profiles. Starch grain morphology was distinctively altered in one of the mutants. The growth of strain PK4 was comparable to that of the wild type under stress-free culture conditions, and the mutant also produced large quantities of lipids, a combination of traits that may be of commercial interest. Thus, heavy-ion irradiation is an effective mutagenic agent for microalgae and may have potential in the production of strains with gain-of-function phenotypes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Promp photon yield and υ2 coefficent from gluon fusion induced by magnetic field in heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Castaño-Yepes Jorge David

    2018-01-01

    Full Text Available We compute the production of prompt photons and the υ2 harmonic coefficient in relativistic heavy-ion collisions induced by gluon fusion in the presence of an intense magnetic field, during the early stages of the reaction. The calculations take into account several parameters which are relevant to the description of the experimental transverse momentum distribution, and elliptic flow for RHIC and LHC energies. The main imput is the strenght of the magnetic field which varies in magnitude from 1 to 3 times the pion mass squared, and allows the gluon fusion that otherwise is forbidden in the absence of the field. The high gluon occupation number and the value of the saturation scale also play an important role in our calculation, as well as a flow velocity and geometrical factors. Our results support the idea that the origin of at least some of the photon excess observed in heavy-ion experiments may arise from magnetic field induced processes, and gives a good description of the experimental data.

  6. The high current transport experiment for heavy ion inertial fusion

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. High current transport experiment for heavy ion inertial fusion

    Directory of Open Access Journals (Sweden)

    L. R. Prost

    2005-02-01

    Full Text Available The High Current Experiment at Lawrence Berkeley National Laboratory is part of the U.S. 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 ∼0.2  μC/m over long pulse durations (4  μs 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^{+} 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 (≈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.

  8. High current injector for heavy ion fusion

    Science.gov (United States)

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

    1993-05-01

    A 2 MV, 800 mA, K(+) injector for heavy ion fusion studies is under construction. This new injector is a one-beam version of the proposed 4-beam ILSE injector. A new 36-module MARX is being built to achieve a 5 micro-s flat top. The high voltage generator is stiff (less than 5k Omega) to minimize effects of beam-induced transients. A large (approximately 7 in. diameter) curved hot alumina-silicate source emits a 1 micro-s long beam pulse through a gridless extraction electrode, and the ions are accelerated to 1 MV in a diode configuration. Acceleration to 2 MV takes place in a set of electrostatic quadrupole (ESQ) units, arranged to simultaneously focus and accelerate the ion beam. Heavy shields and other protection devices have been built in to minimize risks of high voltage breakdown. Beam aberration effects through the ESQ have been studied extensively with theory, simulations, and scaled experiments. The design, simulations, experiments, and engineering of the ESQ injector will be presented.

  9. Inertially confined fusion using heavy ion drivers

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-10-01

    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. Inertially confined fusion using heavy ion drivers

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-10-01

    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.

  11. Strange Particles and Heavy Ion Physics

    Energy Technology Data Exchange (ETDEWEB)

    Bassalleck, Bernd [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy; Fields, Douglas [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy

    2016-04-28

    This very long-running grant has supported many experiments in nuclear and particle physics by a group from the University of New Mexico. The gamut of these experiments runs from many aspects of Strangeness Nuclear Physics, to rare Kaon decays, to searches for exotic Hadrons such as Pentaquark or H-Dibaryon, and finally to Spin Physics within the PHENIX collaboration at RHIC. These experiments were performed at a number of laboratories worldwide: first and foremost at Brookhaven National Lab (BNL), but also at CERN, KEK, and most recently at J-PARC. In this Final Technical Report we summarize progress and achievements for this award since our last Progress Report, i.e. for the period of fall 2013 until the award’s termination on November 30, 2015. The report consists of two parts, representing our two most recent experimental efforts, participation in the Nucleon Spin Physics program of the PHENIX experiment at RHIC, the Relativistic Heavy Ion Collider at BNL – Task 1, led by Douglas Fields; and participation in several Strangeness Nuclear Physics experiments at J-PARC, the Japan Proton Accelerator Research Center in Tokai-mura, Japan – Task 2, led by Bernd Bassalleck.

  12. Heavy ion acceleration at parallel shocks

    Directory of Open Access Journals (Sweden)

    V. L. Galinsky

    2010-11-01

    Full Text Available A study of alpha particle acceleration at parallel shock due to an interaction with Alfvén waves self-consistently excited in both upstream and downstream regions was conducted using a scale-separation model (Galinsky and Shevchenko, 2000, 2007. The model uses conservation laws and resonance conditions to find where waves will be generated or damped and hence where particles will be pitch-angle scattered. It considers the total distribution function (for the bulk plasma and high energy tail, so no standard assumptions (e.g. seed populations, or some ad-hoc escape rate of accelerated particles are required. The heavy ion scattering on hydromagnetic turbulence generated by both protons and ions themselves is considered. The contribution of alpha particles to turbulence generation is important because of their relatively large mass-loading parameter Pα=nαmα/npmp (mp, np and mα, nα are proton and alpha particle mass and density that defines efficiency of wave excitation. The energy spectra of alpha particles are found and compared with those obtained in test particle approximation.

  13. A radial TPC for heavy ions

    CERN Document Server

    Garabatos, C

    2000-01-01

    The CERES experiment at the CERN SPS has been recently upgraded with a TPC with radial drift field, the first one of its sort. Constructed during 1998, it has been successfully operated in commissioning and physics runs, with muon, proton, and heavy-ion beams. A high voltage electrode of about 0.5 m radius is surrounded by sixteen 2 m long readout chambers, placed at a radius of 1.3 m, with chevron-shaped readout pads. The field cage is enclosed by two low-mass voltage degraders at each end of the cylindrical structure. A Ne-CO/sub 2/ [80-20] gas mixture allows for a safe operation and good transport properties under drift fields ranging from 200 to 600 V/cm. A spatial resolution better than 700 microns and 350 microns in r and rdelta (phi), respectively, has been achieved in a highly inhomogeneous magnetic field. Details of its construction as well as results of the operation and performance in a high multiplicity environment are presented. (0 refs).

  14. Status of the relativistic heavy ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Karl, F. [Brookhaven National Lab., Upton, NY (United States)

    1999-07-01

    At the present time, commissioning of the 3.8 kilometer Relativistic Heavy Ion Collider (RHIC) is in full swing. On July 16, 1999, the commissioners were successful in circulating a Gold Ion Beam for the first time, in the Blue Ring, as power supplies were being checked out for beam into the Yellow Ring. The commissioning schedule is to accelerate beam in the Blue Ring, then spiral and accelerate beam in the Yellow Ring, then if all goes well, obtain some collisions, all before a fast approaching shutdown in mid-August. The four experimental regions, Star, Phenix, Brahms and Phobos are gearing up for their maiden beam runs and much effort is being spent to make the thirst glimpse of the beam an exciting one. Our Alignment Group has been working closely with the experimenters in these areas, mostly with MANCAT type component pre-surveys and in the near future installing and locating these various components relative to the RHIC Beam Line. (author)

  15. Heavy Ion physics in ATLAS and CMS

    CERN Document Server

    Kodolova, Olga

    2008-01-01

    We will present the capabilities of the ATLAS and CMS experiments to explore the heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies $\\sqrt{s_{_{NN}}}$ = 5.5 TeV, will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction (QCD) in extreme conditions of temperature, density and low parton momentum fraction. The current paper will give an overview of the potential of ATLAS and CMS to carry out a set of representative Pb-Pb measurements. These include ``bulk'' observables, like charged hadron multiplicity, low $p_{\\rm T}$ inclusive hadron identified spectra and elliptic flow -- which provide information on the collective properties of the system; as well as perturbative processes, such as quarkonia, heavy-quarks, jets, $\\gamma$-jet, and high $p_{\\rm T}$ hadrons --- which yield ``tomographic'' information of the hottest and densest phases...

  16. Imaging instrument for positron emitting heavy ion beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Llacer, J.; Chatterjee, A.; Jackson, H.C.; Lin, J.C.; Zunzunegui, M.V.

    1978-10-01

    The design and performance of an instrument for the imaging of coincidence annihilation gamma rays emitted from the end point of the trajectories of radioactive high-energy heavy ions is described. The positron-emitting heavy ions are the result of nuclear fragmentation of accelerated heavy ions used in cancer therapy or diagnostic medicine. The instrument constructed is capable of locating the ion beam trajectory end point within 1 mm for an injected activity of 200 nanoCi in a measurement time of 1 sec in some favorable conditions. Limited imaging in three dimensions is also demonstrated.

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

    Science.gov (United States)

    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.

  18. Color screening and regeneration of bottomonia in high-energy heavy-ion collisions

    Science.gov (United States)

    Du, X.; He, M.; Rapp, R.

    2017-11-01

    The production of ground-state and excited bottomonia in ultrarelativistic heavy-ion collisions is investigated within a kinetic-rate equation approach including regeneration. We augment our previous calculations by an improved treatment of medium effects, with temperature-dependent binding energies and pertinent reaction rates, B -meson resonance states in the equilibrium limit near the hadronization temperature, and a lattice-QCD based equation of state for the bulk medium. In addition to the centrality dependence of the bottomonium yields, we compute their transverse-momentum (pT) spectra and elliptic flow with momentum-dependent reaction rates and a regeneration component based on b -quark spectra from a nonperturbative transport model of heavy-quark diffusion. The latter has noticeable consequences for the shape of the bottomonium pT spectra. We quantify how uncertainties in the various modeling components affect the predictions for observables. Based on this we argue that the Υ (1 S ) suppression is a promising observable for mapping out the in-medium properties of the QCD force, while Υ (2 S ) production can help to quantify the role of regeneration from partially thermalized b quarks.

  19. Isotope composition and ratios neutron/proton of nuclear matter emitted in heavy ion reactions at intermediate energies; Composition isotopique et ratios neutrons/protons de la matiere nucleaire emise dans les reactions d'ions lourds aux energies intermediaires

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, D

    2005-07-01

    Reaction cross sections for heavy ions collisions at intermediate energies are dominated by binary dissipative collisions. In those reactions, three emission sources can be identified: quasi-projectile (QP), quasi-target (QT) and the mid-rapidity source (MRS). The QP and QT are excited nuclei that keep a strong memory of the entrance channel after the first stage of the collision in which the projectile and target are in contact. The MRS has velocities between that of QP and QT and its formation is believed to be due, in part, to a dynamical breakup of a neck structure formed between the projectile and the target. Up to now, there are many experimental evidences showing that light particles and fragments produced at mid-rapidity are more neutron-rich than those emitted from the QP or QT. Despite those observations, the question about whether or not the complete nuclear material in the MRS is enriched in neutrons is still open. The goal of the work is to study the neutron and proton composition of the MRS and QP. Particularly, finding if the MRS nuclear material is enriched in neutrons compared to the system neutron to proton ratio (N/Z) is the main objective. Two reactions are studied: {sup 58}Ni + {sup 58}Ni at 52 MeV/nucleon and {sup 64}Zn + {sup 64}Zn at 45 MeV/nucleon. The charged particles produced in the {sup 58}Ni + {sup 58}Ni collisions were detected with the INDRA array and neutron multiplicities for the reaction were evaluated in the HERACLES 2001 experiment using the {sup 36}Ar + {sup 58}Ni at 50 MeV/nucleon. Data for the {sup 64}Zn + {sup 64}Zn reaction were obtained with the FIRST detector with LASSA telescopes and neutron detectors added to the setup. On an event-by-event basis, the QP source and the MRS are reconstructed using a statistical method and velocity cuts. The MRS average N/Z ratios are above the original N/Z ratio of the system for the centrality range studied. QP average N/Z ratios are always below the original N/Z ratio of the system for

  20. An integrated Boltzmann+hydrodynamics approach to heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Hannah

    2009-04-22

    In this thesis the first fully integrated Boltzmann+hydrodynamics approach to relativistic heavy ion reactions has been developed. After a short introduction that motivates the study of heavy ion reactions as the tool to get insights about the QCD phase diagram, the most important theoretical approaches to describe the system are reviewed. The hadron-string transport approach that this work is based on is the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) approach. Predictions for the charged particle multiplicities at LHC energies are made. The next step is the development of a new framework to calculate the baryon number density in a transport approach. Time evolutions of the net baryon number and the quark density have been calculated at AGS, SPS and RHIC energies. Studies of phase diagram trajectories using hydrodynamics are performed. The hybrid approach that has been developed as the main part of this thesis is based on the UrQMD transport approach with an intermediate hydrodynamical evolution for the hot and dense stage of the collision. The full (3+1) dimensional ideal relativistic one fluid dynamics evolution is solved using the SHASTA algorithm. Three different equations of state have been used, namely a hadron gas equation of state without a QGP phase transition, a chiral EoS and a bag model EoS including a strong first order phase transition. For the freeze-out transition from hydrodynamics to the cascade calculation two different set-ups are employed. The parameter dependences of the model are investigated and the time evolution of different quantities is explored. The hybrid model calculation is able to reproduce the experimentally measured integrated as well as transverse momentum dependent v{sub 2} values for charged particles. The multiplicity and mean transverse mass excitation function is calculated for pions, protons and kaons in the energy range from E{sub lab}=2-160 A GeV. The HBT correlation of the negatively charged pion source

  1. Sample Management System for Heavy Ion Irradiation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A robotic sample management device and system for the exposure of biological and material specimens to heavy ion beams of the NASA Space Radiation Laboratory (NSRL)...

  2. Failure Analysis of Heavy-Ion-Irradiated Schottky Diodes

    Science.gov (United States)

    Casey, Megan C.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Topper, Alyson D.; Campola, Michael J.; Label, Kenneth A.

    2017-01-01

    In this work, we use high- and low-magnitude optical microscope images, infrared camera images, and scanning electron microscope images to identify and describe the failure locations in heavy-ion-irradiated Schottky diodes.

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

    Science.gov (United States)

    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.

  4. Beam loss mechanisms in relativistic heavy-ion colliders

    CERN Document Server

    Bruce, Roderik; Gilardoni, S; Wallén, E

    2009-01-01

    The Large Hadron Collider (LHC), the largest particle accelerator ever built, is presently under commissioning at the European Organization for Nuclear Research (CERN). It will collide beams of protons, and later Pb82+ ions, at ultrarelativistic energies. Because of its unprecedented energy, the operation of the LHC with heavy ions will present beam physics challenges not encountered in previous colliders. Beam loss processes that are harmless in the presently largest operational heavy-ion collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, risk to cause quenches of superconducting magnets in the LHC. Interactions between colliding beams of ultrarelativistic heavy ions, or between beam ions and collimators, give rise to nuclear fragmentation. The resulting isotopes could have a charge-to-mass ratio different from the main beam and therefore follow dispersive orbits until they are lost. Depending on the machine conditions and the ion species, these losses could occur in loca...

  5. Background Effects on Jet Detection in Heavy Ion Collisions

    Science.gov (United States)

    Aukerman, Alexander; Hughes, Charles; Krobatch, Thomas; Matyja, Adam; Nattrass, Christine; Neuhas, James; Sorensen, Soren; Witt, Will

    2017-09-01

    Heavy ion collisions performed at the LHC and RHIC at large energy scales produce a liquid of quarks and gluons known as a Quark-Gluon Plasma (QGP). Jets, which are collimated bunches of particles emitted from highly energetic partons, are produced at the early stages of these collisions, and can provide information about the properties of the QGP. Partonic energy loss in the medium can by quantified by measurements of fragmentation functions. However, the high background energies resulting from emissions uncorrelated to the initial hard scatterings in the heavy ion collisions place limitations on jet detection methods and fragmentation measurements. For the purpose of investigating the limitations on these current jet detection methods we generated a heavy ion background based on charged hadron data. We explore the behavior of a jet finding algorithm with our generated background to examine how the presence of a heavy ion background may affect the measurements of jet properties.

  6. Gamma-ray spectroscopy with relativistic exotic heavy-ions

    Indian Academy of Sciences (India)

    Abstract. Feasibility of gamma-ray spectroscopy at relativistic energies with exotic heavy-ions and new generation of germanium detectors (segmented Clover) is discussed. An experiment with such detector array and radioactive is discussed.

  7. Argonne superconducting heavy-ion linac

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, L.M.; Benaroya, R.; Clifft, B.E.; Jaffey, A.H.; Johnson, K.W.; Khoe, T.K.; Scheibelhut, C.H.; Shepard, K.W.; Wangler, Y.Z.

    1976-01-01

    A summary is given of the status of a project to develop and build a small superconducting linac to boost the energy of heavy ions from an existing tandem electrostatic accelerator. The design of the system is well advanced, and construction of major components is expected to start in late 1976. The linac will consist of independently-phased resonators of the split-ring type made of niobium and operating at a temperature of 4.2/sup 0/K. The resonance frequency is 97 MHz. Tests on full-scale resonators lead one to expect accelerating fields of approximately 4 MV/m within the resonators. The linac will be long enough to provide a voltage gain of at least 13.5 MV, which will allow ions with A less than or approximately 80 to be accelerated above the Coulomb barrier of any target. The modular nature of the system will make future additions to the length relatively easy. A major design objective is to preserve the good quality of the tandem beam. This requires an exceedingly narrow beam pulse, which is achieved by bunching both before and after the tandem. Focusing by means of superconducting solenoids within the linac limit the radial size of the beam. An accelerating structure some 15 meters downstream from the linac will manipulate the longitudinal phase ellipse so as to provide the experimenter with either very good energy resolution (..delta..E/E approximately equal to 2 x 10/sup -4/) or very good time resolution (..delta.. t approximately equal to 30 psec).

  8. Residual activity induced by heavy ions and beam-loss criteria for heavy-ion accelerators

    Directory of Open Access Journals (Sweden)

    I. Strašík

    2010-07-01

    Full Text Available The paper presents results of FLUKA simulations of the residual activity induced by heavy ions in two target configurations representing: (1 a beam pipe of an accelerator and (2 a bulky accelerator structure like a magnet yoke or a coil. The target materials were stainless steel and copper representing the most common construction materials used for basic accelerator components. For these two materials, the inventory of the induced isotopes depends mainly on the target material and much less on the projectile species. Time evolution of the induced activity can be described by means of a generic curve that is independent from the projectile mass. Dependence of the induced residual activity on selected ion beam parameters was studied. The main goal of the study was establishing a scaling law expanding the existing proton beam-loss tolerance to heavy-ion beams. This scaling law enables specifying beam-loss criteria for projectile species from proton up to uranium at energies from 200  MeV/u up to 1  GeV/u.

  9. Heavy Ions at the LHC Physics Perspectives and Experimental Program

    CERN Document Server

    Schükraft, Jürgen

    2002-01-01

    Ultrarelativistic heavy ion physics is entering the new era of collider experiments with the start-up of RHIC at BNL and construction for detectors at HC well under way. At this crossroads, the article will give a summary of the experimental program and our current view of heavy ion physics at the LHC, concentrating in particular on physics topics that are different or unique compared to current facilities.

  10. Heavy-ion physics at high baryon densities

    Directory of Open Access Journals (Sweden)

    Friese Volker

    2015-01-01

    Full Text Available Currently, several experimental programmes, both at existing and at future accelerator facilities, aim at investigating strongly interacting matter with nuclear collisions at energies below top SPS energy. These activities complement the heavy-ion experiments conducted at the highest available energies at the RHIC and LHC accelerators. In this report, we discuss the motivation for and prospects of the low-energy heavy-ion programmes.

  11. Performance of the Alice muon spectrometer. Weak boson production and measurement in heavy-ion collisions at LHC; Performance du spectrometre a muons d'ALICE. Production et mesure des bosons faibles dans des collisions d'ions lourds aupres du LHC

    Energy Technology Data Exchange (ETDEWEB)

    Conesa del valle, Z

    2007-07-15

    Lattice QCD predicts a transition from a hadronic phase to a Quark Gluon Plasma phase, QGP, for temperatures above 10{sup 13} K. Heavy-ion collisions are proposed to recreate it in laboratory. With such a purpose, the LHC (Large Hadron Collider) will provide Pb-Pb collisions at 5.5 TeV/u, and the ALICE experiment will permit to explore them. In particular, the ALICE muon spectrometer will permit to investigate the muon related probes (quarkonia, open beauty,...). The expected apparatus performances to measure muons and dimuons are discussed. A factorization technique is employed to unravel the different contributions to the global efficiency. Results indicate that the detector should be able to measure muons up to pT {approx} 100 GeV/c with a resolution of about 10 per cent. We show that weak bosons production could be measured for the first time in heavy-ion collisions. Single muon p{sub T} and dimuons invariant mass distributions will probe W and Z production. As mainly muons from b- and c-quarks decays will populate the intermediate-p{sub T} of 5 - 25 GeV/c, heavy quark in-medium energy loss calculations indicate that the single muon spectra would be suppressed by a factor 2-4 in the most central 0 - 10% Pb-Pb collisions at 5.5 TeV. However, for p{sub T} > 35 GeV/c the weak boson decays are predominant, and no suppression is expected. Estimations indicate that the b- and W-muons crossing point shifts down in transverse momenta by 5 to 7 GeV/c in the most central 0 - 10% Pb-Pb collisions at 5.5 TeV. (author)

  12. Radiation Physics and Chemistry in Heavy-ion Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Kimura, M.

    2007-12-01

    Full Text Available Heavy ions, such as carbon and oxygen ions, are classified as high-LET radiations, and produce a characteristic dose-depth distribution different from that of low-LET radiations such as γ-rays, xrays and electrons. Heavy ions lose less energy at the entrance to an irradiated biological system up to some depth than the low-LET radiations, while they deposit a large amount of dose within a very narrow range at a certain depth, producing the characteristic sharp peak called the Bragg peak. Therefore, by controlling the Bragg peak, it becomes possible to irradiate only the tumor region in a pin-point manner, while avoiding irradiation of the normal tissue, thus making heavyion therapy ideal for deep-seated tumor treatment. Clinical results on more than 2400 patients are very encouraging. However, very little is known about what is going on in terms of physics and chemistry inside the Bragg peak. In this paper the current status of our understanding of heavy-ion interactions and remaining problems of physics and chemistry for the heavy-ion treatment are explored, particularly in the Bragg peak region. Specially, the survey of the basic physical quantity, the mean energy required to form an ion pair (Wvalue for heavy ions of interest for radiotherapy is presented. Finally, the current clinical status of heavy-ion therapy is presented.

  13. Modeling and Analysis of Ultrarelativistic Heavy Ion Collisions

    Science.gov (United States)

    McCormack, William; Pratt, Scott

    2014-09-01

    High-energy collisions of heavy ions, such as gold, copper, or uranium serve as an important means of studying quantum chromodynamic matter. When relativistic nuclei collide, a hot, energetic fireball of dissociated partonic matter is created; this super-hadronic matter is believed to be the quark gluon plasma (QGP), which is theorized to have comprised the universe immediately following the big bang. As the fireball expands and cools, it reaches freeze-out temperatures, and quarks hadronize into baryons and mesons. To characterize this super-hadronic matter, one can use balance functions, a means of studying correlations due to local charge conservation. In particular, the simple model used in this research assumed two waves of localized charge-anticharge production, with an abrupt transition from the QGP stage to hadronization. Balance functions were constructed as the sum of these two charge production components, and four parameters were manipulated to match the model's output with experimental data taken from the STAR Collaboration at RHIC. Results show that the chemical composition of the super-hadronic matter are consistent with that of a thermally equilibrated QGP. High-energy collisions of heavy ions, such as gold, copper, or uranium serve as an important means of studying quantum chromodynamic matter. When relativistic nuclei collide, a hot, energetic fireball of dissociated partonic matter is created; this super-hadronic matter is believed to be the quark gluon plasma (QGP), which is theorized to have comprised the universe immediately following the big bang. As the fireball expands and cools, it reaches freeze-out temperatures, and quarks hadronize into baryons and mesons. To characterize this super-hadronic matter, one can use balance functions, a means of studying correlations due to local charge conservation. In particular, the simple model used in this research assumed two waves of localized charge-anticharge production, with an abrupt transition

  14. Heavy ion time-of-flight ERDA of high dose metal implanted germanium

    Energy Technology Data Exchange (ETDEWEB)

    Dytlewski, N.; Evans, P.J.; Noorman, J.T. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Wielunski, L.S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics; Bunder, J. [New South Wales Univ., Wollongong, NSW (Australia). Wollongong Univ. Coll

    1996-12-31

    With the thick Ge substrates used in ion implantation, RBS can have difficulty in resolving the mass-depth ambiguities when analysing materials composed of mixtures of elements with nearly equal masses. Additional, and complimentary techniques are thus required. This paper reports the use of heavy ion time-of-flight elastic recoil detection analysis (ToF- ERDA), and conventional RBS in the analysis of Ge(100) implanted with high dose Ti and Cu ions from a MEWA ion source . Heavy ion ToF ERDA has been used to resolve, and profile the implanted transition metal species, and also to study any oxygen incorporation into the sample resulting from the implantation, or subsequential reactions with air or moisture. This work is part of a study on high dose metal ion implantation of medium atomic weight semiconductor materials. 13 refs., 6 figs.

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

    Science.gov (United States)

    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.

  16. Thermal electromagnetic radiation in heavy-ion collisions

    Science.gov (United States)

    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.

  17. Review of Recent Results in Heavy Ion Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Csernai Laszlo P.

    2014-03-01

    Full Text Available Fluid dynamical phenomena in high energy heavy ion reactions were predicted in the 1970s and still today these are the most dominant and basic observables. With increasing energy and the reach of QGP the low viscosity of the plasma became apparent and this brought a new revolution in the fluid dynamical studies. The high energy and low viscosity made it possible to observe fluctuations up to high multipolarity flow harmonics. This is an obvious, direct proof of the low viscosity of QGP. Many aspects of these fluctuations are under intensive study today. The low viscosity opened ways to observe special fluid dynamical turbulent phenomena. These may arise from random fluctuations, as well as from the global symmetries of peripheral collisions. At LHC energies the angular momentum of the participant matter can reach 106ħ, which leads to rotation and turbulent instabilities, like the Kelvin-Helmholtz instability. Low viscosity ensures that these remain observable at the final freeze-out stages of the collision. Thus new investigations in addition to the standard flow analysis methods became possible. Femtoscopy may also detect rotation and turbulence. Due to the high local thermal vorticity, particle polarization and orbital rotation may reach thermal and mechanical equilibrium. This leads to baryon polarization which, in given directions may be detectable.

  18. Model of wet chemical etching of swift heavy ions tracks

    Science.gov (United States)

    Gorbunov, S. A.; Malakhov, A. I.; Rymzhanov, R. A.; Volkov, A. E.

    2017-10-01

    A model of wet chemical etching of tracks of swift heavy ions (SHI) decelerated in solids in the electronic stopping regime is presented. This model takes into account both possible etching modes: etching controlled by diffusion of etchant molecules to the etching front, and etching controlled by the rate of a reaction of an etchant with a material. Olivine ((Mg0.88Fe0.12)2SiO4) crystals were chosen as a system for modeling. Two mechanisms of chemical activation of olivine around the SHI trajectory are considered. The first mechanism is activation stimulated by structural transformations in a nanometric track core, while the second one results from neutralization of metallic atoms by generated electrons spreading over micrometric distances. Monte-Carlo simulations (TREKIS code) form the basis for the description of excitations of the electronic subsystem and the lattice of olivine in an SHI track at times up to 100 fs after the projectile passage. Molecular dynamics supplies the initial conditions for modeling of lattice relaxation for longer times. These simulations enable us to estimate the effects of the chemical activation of olivine governed by both mechanisms. The developed model was applied to describe chemical activation and the etching kinetics of tracks of Au 2.1 GeV ions in olivine. The estimated lengthwise etching rate (38 µm · h-1) is in reasonable agreement with that detected in the experiments (24 µm · h-1).

  19. Thermal electromagnetic radiation in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, R. [Texas A and M University, Cyclotron Institute and Department of Physics and Astronomy, College Station, TX (United States); Hees, H. van [Goethe-Universitaet Frankfurt, Institut fuer Theoretische Physik, Frankfurt (Germany); Frankfurt Institute of Advanced Studies (FIAS), Frankfurt (Germany)

    2016-08-15

    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. (orig.)

  20. Production of Energetic Light Fragments in Spallation Reactions

    Directory of Open Access Journals (Sweden)

    Mashnik Stepan G.

    2014-03-01

    Full Text Available Different reaction mechanisms contribute to the production of light fragments (LF from nuclear reactions. Available models cannot accurately predict emission of LF from arbitrary reactions. However, the emission of LF is important formany applications, such as cosmic-ray-induced single event upsets, radiation protection, and cancer therapy with proton and heavy-ion beams, to name just a few. The cascade-exciton model (CEM and the Los Alamos version of the quark-gluon string model (LAQGSM, as implemented in the CEM03.03 and LAQGSM03.03 event generators used in the Los Alamos Monte Carlo transport code MCNP6, describe quite well the spectra of fragments with sizes up to 4He across a broad range of target masses and incident energies. However, they do not predict high-energy tails for LF heavier than 4He. The standard versions of CEM and LAQGSM do not account for preequilibrium emission of LF larger than 4He. The aim of our work is to extend the preequilibrium model to include such processes. We do this by including the emission of fragments heavier than 4He at the preequilibrium stage, and using an improved version of the Fermi Break-up model, providing improved agreement with various experimental data.

  1. Two-Photon Interactions with Nuclear Breakup in Relativistic Heavy Ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Baltz, Anthony J.; Gorbunov, Yuri; R Klein, Spencer; Nystrand, Joakim

    2010-07-07

    Highly charged relativistic heavy ions have high cross-sections for two-photon interactions. The photon flux is high enough that two-photon interactions may be accompanied by additional photonuclear interactions. Except for the shared impact parameter, these interactions are independent. Additional interactions like mutual Coulomb excitation are of experimental interest, since the neutrons from the nuclear dissociation provide a simple, relatively unbiased trigger. We calculate the cross sections, rapidity, mass and transverse momentum (p{sub T}) distributions for exclusive {gamma}{gamma} production of mesons and lepton pairs, and for {gamma}{gamma} reactions accompanied by mutual Coulomb dissociation. The cross-sections for {gamma}{gamma} interactions accompanied by multiple neutron emission (XnXn) and single neutron emission (1n1n) are about 1/10 and 1/100 of that for the unaccompanied {gamma}{gamma} interactions. We discuss the accuracy with which these cross-sections may be calculated. The typical p{sub T} of {gamma}{gamma} final states is several times smaller than for comparable coherent photonuclear interactions, so p{sub T} may be an effective tool for separating the two classes of interactions.

  2. Jet Quenching in Relativistic Heavy Ion Collisions at the LHC

    CERN Document Server

    Angerami, Aaron

    Jet production in relativistic heavy ion collisions is studied using Pb+Pb collisions at a center of mass energy of 2.76 TeV per nucleon. The measurements reported here utilize data collected with the ATLAS detector at the LHC from the 2010 Pb ion run corresponding to a total integrated luminosity of 7 μb−1. The results are obtained using fully reconstructed jets using the anti-kt algorithm with a per-event background subtraction procedure. A centrality-dependent modification of the dijet asymmetry distribution is observed, which indicates a higher rate of asymmetric dijet pairs in central collisions relative to peripheral and pp collisions. Simultaneously the dijet angular correlations show almost no centrality dependence. These results provide the first direct observation of jet quenching. Measurements of the single inclusive jet spectrum, measured with jet radius parameters R = 0.2,0.3,0.4 and 0.5, are also presented. The spectra are unfolded to correct for the finite energy resolution introduced by bot...

  3. Single electrons from heavy-flavor mesons in relativistic heavy-ion collisions

    Science.gov (United States)

    Song, Taesoo; Berrehrah, Hamza; Torres-Rincon, Juan M.; Tolos, Laura; Cabrera, Daniel; Cassing, Wolfgang; Bratkovskaya, Elena

    2017-07-01

    We study the single electron spectra from D - and B - meson semileptonic decays in Au+Au collisions at √{sNN}=200 , 62.4, and 19.2 GeV by employing the parton-hadron-string dynamics (PHSD) transport approach that has been shown to reasonably describe the charm dynamics at Relativistic Heavy Ion Collider and Large Hadron Collider energies on a microscopic level. In this approach the initial charm and bottom quarks are produced by using the PYTHIA event generator which is tuned to reproduce the fixed-order next-to-leading logarithm calculations for charm and bottom production. The produced charm and bottom quarks interact with off-shell (massive) partons in the quark-gluon plasma with scattering cross sections which are calculated in the dynamical quasiparticle model that is matched to reproduce the equation of state of the partonic system above the deconfinement temperature Tc. At energy densities close to the critical energy density (≈0.5 GeV /fm3 ) the charm and bottom quarks are hadronized into D and B mesons through either coalescence or fragmentation. After hadronization the D and B mesons interact with the light hadrons by employing the scattering cross sections from an effective Lagrangian. The final D and B mesons then produce single electrons through semileptonic decay. We find that the PHSD approach well describes the nuclear modification factor RAA and elliptic flow v2 of single electrons in d +Au and Au+Au collisions at √{sNN}=200 GeV and the elliptic flow in Au+Au reactions at √{sNN}=62.4 GeV from the PHENIX Collaboration, however, the large RAA at √{sNN}=62.4 GeV is not described at all. Furthermore, we make predictions for the RAA of D mesons and of single electrons at the lower energy of √{sNN}=19.2 GeV . Additionally, the medium modification of the azimuthal angle ϕ between a heavy quark and a heavy antiquark is studied. We find that the transverse flow enhances the azimuthal angular distributions close to ϕ =0 because the heavy

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

    Directory of Open Access Journals (Sweden)

    Douglass M.

    2012-10-01

    Full Text Available 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.

  5. Localized Beampipe Heating due to $e^{-}$ Capture and Nuclear Excitation in Heavy Ion Colliders

    CERN Document Server

    Klein, S R

    2001-01-01

    At heavy ion colliders, two major sources of beam loss are expected to be $e^+e^-$ production, where the $e^-$ is bound to one of the nuclei, and photonuclear excitation and decay via neutron emission. Both processes alter the ions charged to mass ratio by well defined amounts, creating beams of particles with altered magnetic rigidity. These beams will deposit their energy in a localized region of the accelerator, causing localized heating, The size of the target region depends on the collider optics. For medium and heavy ions, at design luminosity at the Large Hadron Collider, local heating may be more than an order of magnitude higher than expected. This could cause magnet quenches if the local cooling is inadequate. The altered-rigidity beams will also produce localized radiation damage. The beams could also be extracted and used for fixed target experiments.

  6. Jet results in heavy ion collisions with the ATLAS experiment at the LHC

    CERN Document Server

    Perepelitsa, Dennis; The ATLAS collaboration

    2015-01-01

    In relativistic collisions of heavy ions, a hot medium with a high density of unscreened color charges is produced, and jets propagating through this medium are known to suffer energy loss. This results in several distinct effects seen in central heavy ion collisions: the yield of inclusive jets measured via the nuclear modification factor is observed to be strongly suppressed; the yield of events with highly asymmetric dijet pairs is observed to be increased; the jet fragmentation is modified. In proton-lead collisions, the production of hard processes is expected to be modified via a modification of nuclear parton distribution functions. While the theory predicts rather small effects to be observed, the data show interesting unexpected features: the nuclear modification factor exhibits a strong centrality dependence; charged particle spectra show an enhancement at large transverse momenta with respect to the proton-proton reference. In this talk, we will summarize the most recent results by ATLAS involving ...

  7. Track Reconstruction in Heavy Ion Events using the CMS Tracker

    CERN Document Server

    Roland, Christof

    2006-01-01

    The Large Hadron Collider at CERN will collide protons at sqrt{S}=14 TeV and lead ions at sqrt{S_{NN} =5.5 TeV. The study of heavy ion collisions is an integral part of the physics program of the Compact Muon Solenoid (CMS). Central heavy ion events at LHC energies are expected to produce a multiplicity of 1500 to 4000 charged particles per unit of rapidity. The CMS detector features a large acceptance and high resolution silicon tracker consisting of pixel and strip detector layers. In this note the algorithms used for pattern recognition in the very high track density environment of heavy ion collisions will be described. Detailed studies using the full detector simulation and reconstruction are presented and achieved reconstruction efficiencies, fake rates and resolutions are discussed.

  8. Ultrarelativistic heavy ion collisions: the first billion seconds

    Energy Technology Data Exchange (ETDEWEB)

    Baym, Gordon

    2016-12-15

    I first review the early history of the ultrarelativistic heavy ion program, starting with the 1974 Bear Mountain Workshop, and the 1983 Aurora meeting of the U.S. Nuclear Science Committtee, just one billion seconds ago, which laid out the initial science goals of an ultrarelativistic collider. The primary goal, to discover the properties of nuclear matter at the highest energy densities, included finding new states of matter – the quark-gluon plasma primarily – and to use collisions to open a new window on related problems of matter in cosmology, neutron stars, supernovae, and elsewhere. To bring out how the study of heavy ions and hot, dense matter in QCD has been fulfilling these goals, I concentrate on a few topics, the phase diagram of matter in QCD, and connections of heavy ion physics to cold atoms, cosmology, and neutron stars.

  9. Elucidating Jet Energy Loss in Heavy Ion Collisions

    CERN Document Server

    Grau, N

    2008-01-01

    Very soon the LHC will provide beams for heavy ion collisions at 5.52 TeV/nucleon. This center-of-mass energy results in a large cross-section for producing high-$E_T$ ($>$ 50 GeV) jets that are distinct from the soft, underlying event. This brings with it the possibility of performing full jet reconstruction to directly study jet energy loss in the medium produced in heavy ion collisions. In this note, we present the current state of jet reconstruction performance studies in heavy ion events using the ATLAS detector. We also discuss the possibilities of energy loss measurements available with full jet reconstruction: single jet $R_{AA}$ and di-jet and $\\gamma$-jet correlations.

  10. arXiv Heavy ions at the Future Circular Collider

    CERN Document Server

    Dainese, A.; Armesto, N.; d'Enterria, D.; Jowett, J.M.; Lansberg, J.P.; Milhano, J.G.; Salgado, C.A.; Schaumann, M.; van Leeuwen, M.; Albacete, J.L.; Andronic, A.; Antonioli, P.; Apolinario, L.; Bass, S.; Beraudo, A.; Bilandzic, A.; Borsanyi, S.; Braun-Munzinger, P.; Chen, Z.; Cunqueiro Mendez, L.; Denicol, G.S.; Eskola, K.J.; Floerchinger, S.; Fujii, H.; Giubellino, P.; Greiner, C.; Grosse-Oetringhaus, J.F.; Ko, C.M.; Kotko, P.; Krajczar, K.; Kutak, K.; Laine, M.; Liu, Y.; Lombardo, M.P.; Luzum, M.; Marquet, C.; Masciocchi, S.; Okorokov, V.; Paquet, J.F.; Paukkunen, H.; Petreska, E.; Pierog, T.; Ploskon, M.; Ratti, C.; Rezaeian, A.H.; Riegler, W.; Rojo, J.; Roland, C.; Rossi, A.; Salam, G.P.; Sapeta, S.; Schicker, R.; Schmidt, C.; Stachel, J.; Uphoff, J.; van Hameren, A.; Watanabe, K.; Xiao, B.W.; Yuan, F.; Zaslavsky, D.; Zhou, K.; Zhuang, P.

    2017-06-22

    The Future Circular Collider (FCC) Study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode, seven times larger than the nominal LHC energies. Operating such machine with heavy ions is an option that is being considered in the accelerator design studies. It would provide, for example, Pb-Pb and p-Pb collisions at sqrt{s_NN} = 39 and 63 TeV, respectively, per nucleon-nucleon collision, with integrated luminosities above 30 nb^-1 per month for Pb-Pb. This is a report by the working group on heavy-ion physics of the FCC Study. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of the Quark-Gluon Plasma, of gluon saturation, of photon-induced collisions, as well as connections with other fields of high-energy physics.

  11. Quark vs Gluon jets in Heavy Ion Collisions

    CERN Document Server

    Drauksas, Simonas

    2017-01-01

    The project concerned quark and gluon jets which are often used as probes of Quantum Chromodynamics(QCD) matter created in nuclear collisions at collider energies. The goal is to look for differences between quark and gluon jets, study their substructure, look for distinguishing features in unquenched (pp collisions) and quenched (heavy ion collisions) jets by using multi-variate analysis which was carried out with the help of ROOT's \\href{https://root.cern.ch/tmva}{TMVA} tool. Mapping out the modification of jets due to medium interactions could give valuable input to constraining the time evolution of the Quark Gluon Plasma created in heavy ion collisions.

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

    Science.gov (United States)

    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.

  13. Heavy ion observation with MIDORI satellite: trapped ACR

    CERN Document Server

    Kohno, T; Yamagiwa, I; Kato, C; Goka, T; Matsumoto, H

    1999-01-01

    The Heavy Ion Telescope (HIT) on board the Japanese earth observation satellite MIDORI (ADEOS) has observed energetic heavy ions at the circular sun-synchronous orbit with an altitude of 800 km and an inclination of 98 deg. . Geomagnetically trapped oxygen and nitrogen at L=2 are clearly observed which is similar to the results of SAMPEX. Their geographical distribution at a long belt from the southern tip of South America to that of Africa is also very close to the SAMPEX observation. The adiabaticity parameter epsilon sub m sub a sub x can be deduced as <=0.1.

  14. Chemical and dynamics properties of heavy ion collisions at RHIC energies by the measurement of the production of the doubly strange baryons in the STAR experiment; Proprietes chimiques et dynamiques des collisions d'ions lourds aux energies du RHIC par la mesure de la production des baryons doublement etranges dans l'experience STAR

    Energy Technology Data Exchange (ETDEWEB)

    Estienne, M

    2005-04-15

    Lattice QCD calculations predict, at {mu}{sub B} {approx} 0, a crossover from ordinary hadronic matter to a Quark Gluon Plasma. Heavy ion collisions have been proposed to recreate it in the laboratory and to study its properties. The Au+Au, d+Au collisions at {radical}(S{sub NN}) = 200 GeV and the Au+Au ones at 62.4 GeV delivered at RHIC have been probed by the measurement of the {xi} particles in the STAR experiment. Their yield evolution with collision energy and system size gives size to the chemical properties of the reaction in the framework of hadronic and statistical models. The {xi} R{sub CP} shows: (1) a meson/baryon dependence for 2 < {sub pT} < 5 GeV/c well reproduced by quark coalescence and recombination models, (2) the formation of a dense matter signed by a R{sub CP} suppression at {sub pT} > 3 GeV/c, (3) strong interactions between constituents suggesting the existence of strong collectivity in the medium. The {xi} transverse flow seems to be interesting to probe the early stage the collision with presumably partonic degrees of freedom. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Kost, M.; Pross, H.D.; Russmann, C.; Schneider, E.; Kiefer, J.; Kraft, G.; Lenz, G.; Becher, W. [Gesellschaft fuer Schwerionenforschung m.b.H., Darmstadt (Germany)

    1994-12-31

    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.

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

    Science.gov (United States)

    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.

  17. Reaction product imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, D.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  18. Photoluminescence and Raman studies in swift heavy ion irradiated ...

    Indian Academy of Sciences (India)

    Photoluminescence and Raman studies in swift heavy ion irradiated polycrystalline aluminum oxide ... Polymers Volume 32 Issue 5 October 2009 pp 515-519 ... A broad photoluminescence (PL) emission with peak at ∼447 nm and two sharp emissions with peak at ∼ 679 and ∼ 695 nm are observed in pristine when ...

  19. Quark-gluon plasma: Status of heavy ion physics

    Indian Academy of Sciences (India)

    produce such energy densities, thereby providing us a chance to test the above prediction. After a brief introduction of the .... bone of the analyses seeking to extract information from the data on whether QGP did form in the heavy ion ..... A similar exercise for S+Au or Pb+Au reveals an enhancement in the low mass region ...

  20. Theory of heavy ion collision physics in hadron therapy

    CERN Document Server

    2013-01-01

    Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features detailed reviews written by leading international researchers. This volume focuses on the theory of heavy ion physics in medicine.

  1. Heavy ion accelerator and associated developments in India

    Indian Academy of Sciences (India)

    c Indian Academy of Sciences. Vol. 59, No. 5. — journal of. November 2002 physics pp. 703–712. Heavy ion accelerator and associated developments in India. G K MEHTA. University of Allahabad, Allahabad 211 002, India. Abstract. Developments of ion accelerator and associated facilities in India are presented. Various.

  2. Transport models for relativistic heavy-ion collisions at Relativistic ...

    Indian Academy of Sciences (India)

    Abstract. We review the transport models that are widely used to study the properties of the quark-gluon plasma formed in relativistic heavy-ion collisions at RHIC and LHC. We show that transport model analysis of two important and complementary observables, the anisotropic flow of bulk hadrons and suppression of ...

  3. What have we learned from relativistic heavy-ion collider?

    Indian Academy of Sciences (India)

    What do we hope and expect to learn in the future? 1. Introduction. The goal of the heavy ion program at the RHIC at Brookhaven National Laboratory is to make and study new forms of matter at energy densities in excess of ten times that of nuclear matter. I will describe the status of this program from a theorist's perspective.

  4. Systematics of elliptic flow in heavy-ion collisions

    Indian Academy of Sciences (India)

    The main goal of ultra-relativistic heavy-ion collisions is to understand the behavior of. QCD under extreme ... collective motion of particles are called as flow and are identified as radial, sideward and elliptic flow. ... expands it becomes more spherical, quenching the driving force that produces the elliptic flow. The elliptic flow ...

  5. What have we learned from relativistic heavy-ion collider?

    Indian Academy of Sciences (India)

    In this talk, I present what I believe we have learned from the recent RHIC heavy ion experiments. The goal of these experiments is to make and study matter at very high energy densities, greater than an order of magnitude larger than that of nuclear matter. Have we made such matter? What have we learned about the ...

  6. Hydrodynamic modelling for relativistic heavy-ion collisions at RHIC ...

    Indian Academy of Sciences (India)

    Nz. 1. Introduction. The quark gluon plasma (QGP) is formed in high-energy heavy-ion collisions at Relativis- .... To obtain final hadrons, pure hydrodynamic simulations assume free hadron resonances directly emitted ... models is realized by a Monte-Carlo event generator, which transforms the hydrody- namic output into ...

  7. Response of silicon position sensitive detectors to heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Read, P.M.; Rotberg, V.H. (UKAEA Atomic Energy Research Establishment, Harwell. Nuclear Physics Div.); Tolfree, D.W.L.; Groves, J. (Science Research Council, Daresbury (UK). Daresbury Lab.)

    1983-01-15

    The pulse height response characteristics of surface barrier and ion implanted position sensitive detectors have been measured. Surface barrier detectors with junctions formed using oxidation by potassium dichromate exhibit small heavy ion pulse height defects indicating thin entrance windows. Ion implanted detectors give considerably larger defects because of penetrating tails in the distribution of implanted ions and electrically active defects.

  8. The response of silicon position sensitive detectors to heavy ions

    Science.gov (United States)

    Read, P. M.; Rotberg, V. H.; Tolfree, D. W. L.; Groves, J.

    1983-01-01

    The pulse height response characteristics of surface barrier and ion implanted position sensitive detectors have been measured. Surface barrier detectors with junctions formed using oxidation by potassium dichromate exhibit small heavy ion pulse height defects indicating thin entrance windows. Ion implanted detectors give considerably larger defects because of penetrating tails in the distribution of implanted ions and electrically active defects.

  9. Elastic recoil detection (ERD) with extremely heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Forster, J.S. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.; Currie, P.J. [Royal Tyrrell Museum, Drumheller, Alberta T0J 0Y0 (Canada); Davies, J.A. [Accelerator Laboratory, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Siegele, R. [Accelerator Laboratory, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Wallace, S.G. [Accelerator Laboratory, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Zelenitsky, D. [Department of Geology and Geophysics, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

    1996-06-01

    Extremely heavy-ion beams such as {sup 209}Bi in elastic recoil detection (ERD) make ERD a uniquely valuable technique for thin-film analysis of elements with mass {<=}100. We report ERD measurements of compositional analysis of dinosaur eggshells and bones. We also show the capability of the ERD technique on studies of thin-film, high-temperature superconductors. (orig.).

  10. Quarkonia at finite temperature in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    2015-05-06

    May 6, 2015 ... ... is reviewed. After a detailed discussion of the current theoretical understanding of quarkonia in a static equilibriated plasma, we discuss quarkonia yield from the fireball created in ultrarelativistic heavy-ion collision experiments. We end with a brief discussion of the experimental results and outlook.

  11. From Heavy-Ion Collisions to Quark Matter course

    CERN Multimedia

    CERN. Geneva HR-RFA

    2006-01-01

    Overview of the experimental activity going on at CERN (SPS and LHC) and at RHIC in view of the understanding of the properties of QCD matter (quark gluon plasma) at high temperatures and densities, through the study of heavy-ion collisions at very high energies.

  12. Structural and electrical properties of swift heavy ion beam irradiated ...

    Indian Academy of Sciences (India)

    Unknown

    search. We have investigated the mixing at Co/Si interface by swift heavy ion beam induced irradiation in the ... films are often employed in semiconductor technology and are used as ... rements at Co/Si interface were carried out online in the.

  13. Heavy ion collisions at collider energies – Insights from PHENIX

    Indian Academy of Sciences (India)

    ken 305-0801, Japan. 15Korea University, Seoul ... early stages of high energy heavy-ion collisions where quark matter is expected to form. .... PHENIX has published spectra of charged pions, kaons, protons and their anti-particles over a broad ...

  14. Gamma-ray spectroscopy with relativistic exotic heavy-ions

    Indian Academy of Sciences (India)

    Vol. 57, No. 1. — journal of. July 2001 physics pp. 161–164. Gamma-ray spectroscopy with relativistic exotic heavy-ions. SAMIT MANDAL, J GERL, H GEISSEL, K HAUSCHILD. ¿. , M HELLSTR ¨OM, ... large [2,3] to perform a meaningful high spin decay spectroscopy of exotic nuclei. At the same time relativistic Coulomb ...

  15. Calculating Fragmentation Functions in Heavy Ion Physics Simulations

    Science.gov (United States)

    Hughes, Charles; Aukerman, Alex; Krobatsch, Thomas; Matyja, Adam; Nattrass, Christine; Neuhaus, James; Sorensen, Soren; Witt, William

    2017-09-01

    A hot dense liquid of quarks and gluons called a Quark Gluon Plasma (QGP) is formed in high energy nuclear collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider. The high energy partons which scatter during these collisions can serve as probes for measuring QGP bulk properties. The details of how partons lose energy to the QGP medium as they traverse it can be used to constrain models of their energy loss. Specifically, measurements of fragmentation functions in the QGP medium can provide experimental constraints on theoretical parton energy loss mechanisms. However, the high background in heavy ion collisions limits the precision of these measurements. We investigate methods for measuring fragmentation functions in a simple model in order to assess their feasibility. We generate a data-driven heavy ion background based on measurements of charged hadron transverse momentum spectra, charged hadron azimuthal flow, and charged hadron rapidity spectra. We then calculate fragmentation functions in this heavy ion background and compare to calculations in proton-proton simulations. We present the current status of these studies.

  16. Physics Opportunities in Ultraperipheral Heavy Ion Collisions at LHC

    OpenAIRE

    Baur, G.

    2001-01-01

    Due to coherence, there are strong electromagnetic fields of short duration in very peripheral heavy ion collisions. They give rise to photon-photon and photon-nucleus collisions with high flux. Photon-photon and photon-hadron physics at various invariant mass scales are discussed.

  17. Heavy ions: Results from the Large Hadron Collider

    Indian Academy of Sciences (India)

    2012-10-02

    Oct 2, 2012 ... accelerator, designed to address some of the most fundamental questions of recent times such as, whether Higgs ... Knowledge of the space-time evolution of the system produced in high-energy heavy-ion collisions .... The information about the freeze-out volume and lifetime of the created system in p–p.

  18. Recent relativistic heavy ion collider results on photon, dilepton and ...

    Indian Academy of Sciences (India)

    large baryon density, the so-called quark gluon plasma. We focus on a specific category of observables: the electromagnetic probes which cover a large spectrum of experimental studies. Keywords. Quark gluon plasma; relativistic heavy ion collider; photon; vector meson; thermal dilepton; heavy quarks. PACS No. 25.75.Cj.

  19. Inferring Magnetospheric Heavy Ion Density using EMIC Waves

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Production of neutron-rich nuclides in the vicinity of N = 126 shell closure in multinucleon transfer reactions

    Directory of Open Access Journals (Sweden)

    Karpov Alexander

    2017-01-01

    Full Text Available Multinucleon transfer in low-energy nucleus-nucleus collisions is widely discussed as a method of production of yet-unknown neutron-rich nuclei hardly accessible (or inaccessible by other methods. Modeling of complicated dynamics of nuclear reactions induced by heavy ions is done within a multidimensional dynamical model of nucleus-nucleus collisions based on the Langevin equations. The model gives a continuous description of the system evolution starting from the well-separated target and projectile in the entrance channel of the reaction up to the formation of final reaction products. In this paper, rather recent sets of experimental data for the 136Xe+198Pt,208Pb reactions are analyzed together with the production cross sections for neutron-rich nuclei in the vicinity of the N = 126 magic shell.

  1. Heavy-ion radiation induced bystander effect in mice

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. Experimental approach to measure thick target neutron yields induced by heavy ions for shielding

    Directory of Open Access Journals (Sweden)

    Trinh N.D.

    2017-01-01

    Full Text Available Double differential (angular and energy neutron distributions were measured using an activation foil technique. Reactions were induced by impinging two low-energy heavy-ion beams accelerated with the GANIL CSS1 cyclotron: (36S (12 MeV/u and 208Pb (6.25 MeV/u onto thick natCu targets. Results have been compared to Monte-Carlo calculations from two codes (PHITS and FLUKA for the purpose of benchmarking radiation protection and shielding requirements. This comparison suggests a disagreement between calculations and experiment, particularly for high-energy neutrons.

  4. Status report on the Lawrence Berkeley Laboratory heavy ion fusion program

    Energy Technology Data Exchange (ETDEWEB)

    Keefe, D.; Faltens, A.; Hoyer, E.

    1978-11-01

    This status report is presented in three sections: (1) a design and cost procedure for heavy-ion induction LINACS, (2) theoretical activities, and (3) the experimental program on heavy ion fusion at LBL. (MOW)

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

    Science.gov (United States)

    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

  6. 1. contribution of the dynamics on the reactions mechanisms in the heavy ions collisions at the intermediary energies (20-100 MeV/A) for the light systems. 2. management of radioactive wastes by new options: nuclear data measurement programme between 20 and 150 MeV; 1. role de la dynamique sur les mecanismes de reactions dans les collisions d'ions lourds aux energies intermediaires (20-100 MeV/A) pour des systemes legers. 2. gestion des dechets radioactifs par des options nouvelles: programme de mesures de donnees nucleaires entre 20 et 150 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Eudes, Ph

    2000-09-22

    The first part concerns the features of emitted charged particles in heavy ions reactions that have been studied in the framework of the semi classical Landau-Vlasov approach for the light system Ar + Al at 65 MeV/nucleon incident energy. The second part is devoted to the radioactive waste management (transmutation), but it was necessary to increase the data banks evaluated in neutrons up to 150-200 MeV and to create a data bank in protons. In the European framework it was decide to focus on three representative elements: lead (spallation target), iron (structure material) and uranium (actinide). (N.C.)

  7. Remarkable optical-potential systematics for lighter heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Brandan, M.E. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Mexico 01000 Distrito Federal (Mexico); McVoy, K.W. [Physics Department, University of Wisconsin, Madison, Wisconsin 53706 (United States)

    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}

  8. Observation of fission modes in heavy ion induced reactions

    Science.gov (United States)

    Itkis, M. G.; Kondratiev, N. A.; Kozulin, E. M.; Oganessian, Yu. Ts.; Pashkevich, V. V.; Pokrovsky, I. V.; Salamatin, V. S.; Rusanov, A. Ya.; Calabretta, L.; Maiolino, C.; Lukashin, K.; Agodi, C.; Bellia, G.; Chubarian, G. G.; Hurst, B. J.; O'Kelly, D.; Schmitt, R. P.; Hanappe, F.; Liatard, E.; Huck, A.; Stuttgé, L.

    1998-02-01

    The fission of the systems 220,224,226Th was investigated by measuring the mass-energy distributions of the fission fragments. The corresponding excitation energies at the saddle point, Esp*, ranged from 16 to 40 MeV. As Esp* decreases, an asymmetric mass component becomes visible on the predominately symmetric mass distribution. The contribution of the asymmetric mode is characterized by the total yield ratio Ys/Ya, which decreases rapidly for the heavier isotopes of thorium. This behavior of Ys/Ya is in qualitative agreement with theoretical calculations. For all isotopes studied, the subtracted asymmetric fission component, Ya=Y1-Ys, exhibits a complex structure, actually showing two components, Ya=Ya1+Ya0, which have average masses Ma1=132 and Ma0=140.

  9. Proceedings of the Workshop on Heavy Ion Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Li, C. C.; Lai, G. Y.

    1978-09-01

    Chromium carbide-nichrome coatings being considered for wear protection of some critical components in high-temperature gas-cooled reactors (HTGR's) were investigated. The coatings were deposited either by the detonation gun or the plasma-arc process. Sliding wear tests were conducted on specimens in a button-on-plate arrangement with sliding velocities of 7.1 x 10/sup -3/ and 7.9 mm/s at 816/sup 0/C in a helium environment simulates HTGR primary coolant chemistry. The coatings containing 75 or 80 wt % chromium carbide exhibited excellent wear resistance. As the chromium carbide content decreased from either 80 or 75 to 55 wt %, with a concurrent decrease in coating hardness, wear-resistance deteriorated. The friction and wear behavior of the soft coating was similar to that of the bare metal--showing severe galling and significant amounts of wear debris. The friction characteristics of the hard coating exhibited a strong velocity dependence with high friction coefficients in low sliding velocity tests ad vice versa. Both the soft coating and bare metal showed no dependence on sliding velocity. The wear behavior observed in this study is of adhesive type, and the wear damage is believed to be controlled primarily by the delamination process.

  10. An Experimental Review on Elliptic Flow of Strange and Multistrange Hadrons in Relativistic Heavy Ion Collisions

    Directory of Open Access Journals (Sweden)

    Shusu Shi

    2016-01-01

    Full Text Available Strange hadrons, especially multistrange hadrons, are good probes for the early partonic stage of heavy ion collisions due to their small hadronic cross sections. In this paper, I give a brief review on the elliptic flow measurements of strange and multistrange hadrons in relativistic heavy ion collisions at Relativistic Heavy Ion Collider (RHIC and Large Hadron Collider (LHC.

  11. Production of very neutron-deficient isotopes near {sup 100}Sn via reactions involving light-particle and cluster emission

    Energy Technology Data Exchange (ETDEWEB)

    La Commara, M.; Gomez del Campo, J.; D' Onofrio, A.; Gadea, A.; Glogowski, M.; Jarillo-Herrero, P.; Belcari, N.; Borcea, R.; De Angelis, G.; Fahlander, C.; Gorska, M.; Grawe, H.; Hellstroem, M.; Kirchner, R.; Rejmund, M.; Roca, V.; Roeckl, E.; Romano, M.; Rykaczewski, K.; Schmidt, K.; Terrasi, F

    2000-04-10

    The production of very neutron-deficient isotopes near {sup 100}Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete-fusion reactions. We measured the cross sections for {sup 99}Cd, {sup 100}In, {sup 101}Sn and {sup 102}In via {sup 58}Ni+{sup 58}Ni fusion reactions followed by cluster emission, and via {sup 58}Ni+{sup 50}Cr fusion reactions accompanied by evaporation of protons, neutrons or {alpha} particles. Both types of reactions yield similar cross sections for the production of exotic nuclei near {sup 100}Sn. The data are discussed in comparison with results obtained from statistical-model calculations.

  12. Heavy ion physics with the ATLAS detector

    CERN Document Server

    Przybycien, Mariusz; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment at the Large Hadron Collider has undertaken a broad physics program to probe and characterize the hot nuclear matter created in relativistic lead-lead collisions. This talk presents recent results on production of jet, electroweak bosons and quarkonium, electromagnetic processes in ultra-peripheral collisions, and bulk particle collectivity from Pb+Pb and p+Pb collisions.

  13. Recent Heavy Ion results from ATLAS experiment

    CERN Document Server

    Olszewski, Andrzej; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the Large Hadron Collider has undertaken a broad physics program to probe and characterize the hot nuclear matter created in relativistic lead-lead collisions. This talk presents recent results on production of jet, eletroweak bosons and quarkonium, electromagnetic processes in ultra-peripheral collisions, and bulk particle collectivity from PbPb and pPb collisions.

  14. Experimental measurement of the 4-d transverse phase space map of a heavy ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, H S

    1997-12-01

    The development and employment of a new diagnostic instrument for characterizing intense, heavy ion beams is reported on. This instrument, the ''Gated Beam Imager'' or ''GBI'' was designed for use on Lawrence Livermore National Laboratory Heavy Ion Fusion Project's ''Small Recirculator'', an integrated, scaled physics experiment and engineering development project for studying the transport and control of intense heavy ion beams as inertial fusion drivers in the production of electric power. The GBI allows rapid measurement and calculation of a heavy ion beam's characteristics to include all the first and second moments of the transverse phase space distribution, transverse emittance, envelope parameters and beam centroid. The GBI, with appropriate gating produces a time history of the beam resulting in a 4-D phase-space and time ''map'' of the beam. A unique capability of the GBI over existing diagnostic instruments is its ability to measure the ''cross'' moments between the two transverse orthogonal directions. Non-zero ''cross'' moments in the alternating gradient lattice of the Small Recirculator are indicative of focusing element rotational misalignments contributing to beam emittance growth. This emittance growth, while having the same effect on the ability to focus a beam as emittance growth caused by non-linear effects, is in principle removable by an appropriate number of focusing elements. The instrument uses the pepperpot method of introducing a plate with many pinholes into the beam and observing the images of the resulting beamlets as they interact with a detector after an appropriate drift distance. In order to produce adequate optical signal and repeatability, the detector was chosen to be a microchannel plate (MCP) with a phosphor readout screen. The heavy ions in the pepperpot beamlets are stopped in the MCP's thin

  15. An overview of experimental results from ultra-relativistic heavy-ion collisions at the CERN LHC: Hard probes

    Directory of Open Access Journals (Sweden)

    Panagiota Foka

    2016-11-01

    Full Text Available The first collisions of lead nuclei, delivered by the CERN Large Hadron Collider (LHC at the end of 2010, at a centre-of-mass energy per nucleon pair sNN= 2.76 TeV, marked the beginning of a new era in ultra-relativistic heavy-ion physics. The study of the properties of the produced hot and dense strongly-interacting matter at these unprecedented energies is currently experimentally pursued by all four big LHC experiments, ALICE, ATLAS, CMS, and LHCb. The more than a factor 10 increase of collision energy at LHC, relative to the previously achieved maximal energy at other collider facilities, results in an increase of production rates of hard probes. This review presents selected experimental results focusing on observables probing hard processes in heavy-ion collisions delivered during the first three years of the LHC operation. It also presents the first results from Run 2 heavy-ion data at the highest energy, as well as from the studies of the reference pp and p–Pb systems, which are an integral part of the heavy-ion programme.

  16. Probing the nuclear symmetry energy with heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    De Filippo E.

    2015-01-01

    Full Text Available Heavy ion collisions (HIC have been widely used to extract the parametrization of symmetry energy term of nuclear equation of state as a function of barionic density. HIC in fact are a unique tool in terrestrial laboratories to explore the symmetry energy around the saturation density (ρ0 = 0.16fm−3 from sub-saturation densities (Fermi energies towards compressed nuclear matter (ρ > 2 − 3ρ0 that can be reached at relativistic energies, as a function of different conditions of temperature, mass asymmetry and isospin. One of the main study at present is to reach a coherent description of EOS of asymmetric nuclear matter from heavy ion collisions of stable and exotic nuclei, nuclear structure studies and astrophysical observations. In this work an overview of the current status of the research is shortly reviewed together with new perspectives aimed to reduce the present experimental and theoretical uncertainties.

  17. Spiraling Beam Illumination Uniformity on Heavy Ion Fusion Target

    CERN Document Server

    Kurosaki, T; Noguchi, K; Koseki, S; Barada, D; Ma, Y Y; Ogoyski, A I; Barnard, J J; Logan, B G

    2012-01-01

    A few percent wobbling-beam illumination nonuniformity is realized in heavy ion inertial confinement fusion (HIF) by a spiraling beam axis motion in the paper. So far the wobbling heavy ion beam (HIB) illumination was proposed to realize a uniform implosion in HIF. However, the initial imprint of the wobbling HIBs was a serious problem and introduces a large unacceptable energy deposition nonuniformity. In the wobbling HIBs illumination, the illumination nonuniformity oscillates in time and space. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs illumination nonuniformity. The wobbling HIBs can be generated in HIB accelerators and the oscillating frequency may be several 100MHz-1GHz. Three-dimensional HIBs illumination computations presented here show that the few percent wobbling HIBs illumination nonuniformity oscillates successfully with the same wobbling HIBs frequency.

  18. Activation of accelerator construction materials by heavy ions

    Science.gov (United States)

    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. Probing transverse momentum broadening in heavy ion collisions

    Directory of Open Access Journals (Sweden)

    A.H. Mueller

    2016-12-01

    Full Text Available We study the dijet azimuthal de-correlation in relativistic heavy ion collisions as an important probe of the transverse momentum broadening effects of a high energy jet traversing the quark–gluon plasma. We take into account both the soft gluon radiation in vacuum associated with the Sudakov logarithms and the jet PT-broadening effects in the QCD medium. We find that the Sudakov effects are dominant at the LHC, while the medium effects can play an important role at RHIC energies. This explains why the LHC experiments have not yet observed sizable PT-broadening effects in the measurement of dijet azimuthal correlations in heavy ion collisions. Future investigations at RHIC will provide a unique opportunity to study the PT-broadening effects and help to pin down the underlying mechanism for jet energy loss in a hot and dense medium.

  20. Heavy ion physics : Exhibition Lepton-Photon 2001

    CERN Multimedia

    2001-01-01

    High-energy Heavy Ion Physics studies strongly interacting matter at extreme energy densities.QCD predicts that at such densities hadronic matter turns into a plasma of deconfined quarks and gluons,the Quark Gluon Plasma (QGP).Matter in the Universe must have existed in this state up to about 10 ms after the Big Bang.Today QGP might exist in the c re of neutron stars.The study of the phase diagram of matter is a new approach to investigate QCD at its natural scale,L QCD ,and to address the fundamental questions of confinement and chiral-symmetry breaking.The combined results obtained by the SPS heavy ion experiments,in particular those obtained with the Pb beam,pr vide compelling evidence for the existence of a new state of matter featuring many of the characteristics predicted for the QGP.The ALICE experiment will carry this research into the LHC era.

  1. The threshold anomaly for heavy-ion scattering

    Energy Technology Data Exchange (ETDEWEB)

    Satchler, G.R.

    1987-01-01

    The real parts of optical potentials deduced from heavy-ion scattering measurements become rapidly more attractive as the bombarding energy is reduced close to the top of the Coulomb barrier. This behavior is explained as a coupled-channels effect, and is related to the corresponding reduction in the absorptive potential through a dispersion relation which expresses the consequences of causality. Another manifestation of this ''anomaly'' is the striking enhancement observed for the near- and sub-barrier fusion of two heavy ions. The barrier penetration model of fusion is examined critically in this context. It is also stressed that similar anomalies could appear in the energy dependence of nonelastic scattering. 21 refs., 4 figs.

  2. <span class="hlt">Heavy-Ion</span> Imaging Applied To Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J. I.; Tobias, C. A.; Capp, M. P.; Benton, E. V.; Holley, W. R.; Gray, Joel E.; Hendee, William R.; Haus, Andrew G.; Properzio, William S.

    1980-08-18

    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.

  3. Activation of accelerator construction materials by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Katrík, P., E-mail: p.katrik@gsi.de [GSI Darmstadt, Planckstrasse 1, D-64291 (Germany); Mustafin, E. [GSI Darmstadt, Planckstrasse 1, D-64291 (Germany); Hoffmann, D.H.H. [TU Darmstadt, Schlossgartenstraße 9, D-64289 (Germany); Pavlovič, M. [FEI STU Bratislava, Ilkovičova 3, SK-81219 (Slovakia); Strašík, I. [GSI Darmstadt, Planckstrasse 1, D-64291 (Germany)

    2015-12-15

    Activation data for an aluminum target irradiated by 200 MeV/u {sup 238}U 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.

  4. Scaled beam merging experiment for heavy ion inertial fusion

    Directory of Open Access Journals (Sweden)

    P. A. Seidl

    2003-09-01

    Full Text Available Transverse beam combining is a cost-saving option employed in many designs for heavy ion fusion drivers. However, the resultant transverse phase space dilution must be minimized so as not to sacrifice focusability at the target. A prototype combining experiment has been completed employing four 3-mA Cs^{+} beams injected at 160 keV. The focusing elements upstream of the merge consist of four quadrupoles and a final combined-function element (quadrupole and dipole. Following the merge, the resultant single beam is transported in a single alternating gradient channel where the subsequent evolution of the distribution function is diagnosed. The results are in fair agreement with particle-in-cell simulations. They indicate that for some heavy ion fusion driver designs, the phase space dilution from merging is acceptable.

  5. Highlights from STAR heavy ion program arXiv

    CERN Document Server

    Okorokov, V.A.

    Recent experimental results obtained in STAR experiment at the Relativistic heavy-ion collider (RHIC) with ion beams will be discussed. Investigations of different nuclear collisions in some recent years focus on two main tasks, namely, detail study of quark-gluon matter properties and exploration of the quantum chromodynamics (QCD) phase diagram. Results at top RHIC energy show clearly the collective behavior of heavy quarks in nucleus-nucleus interactions. Jet and heavy hadron measurements lead to new constraints for energy loss models for various flavors. Heavy-ion collisions are unique tool for the study of topological properties of theory as well as the magneto-hydrodynamics of strongly interacting matter. Experimental results obtained for discrete QCD symmetries at finite temperatures confirm indirectly the topologically non-trivial structure of QCD vacuum. Finite global vorticity observed in non-central Au+Au collisions can be considered as important signature for presence of various chiral effects in ...

  6. Thermodynamic interpretation of multiparticle emission in relativistic heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Gleeson, A.M.; Raha, S.

    1980-02-01

    The scattering of the heavy ion Ne from NaF is analyzed at relativistic energy. The spectra of the emission fragments are studied for evidence of a thermodynamic-hydrodynamic collective motion. The spectra of pion, deuteron, and proton emission are fitted for fixed beam and target. The fit is consistent with an interpretation of an expanding hot fluid of interacting nucleons. 2 figures.

  7. New operational beam for the CERN heavy ion program

    CERN Document Server

    Chamings, J A; Hill, C E; Küchler, D; Lombardi, A M; O'Neill, M; Scrivens, R

    2004-01-01

    The use of indium beams in place of lead beams for the CERN heavy ion program was studied. It was found that the Indium beam emittance was measured downstream of the spectrometer by a quadrupole sean. The frequency of source adjustments to keep the beam current at a certain level was also studied. Results shows that the oven-resistance fluctuations were partially solved by using the oven power controller. (Edited abstract) 4 Refs.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Heavy ion linear accelerator for radiation damage studies of materials

    Energy Technology Data Exchange (ETDEWEB)

    Kutsaev, Sergey V.; Mustapha, Brahim; Ostroumov, Peter N.; Nolen, Jerry; Barcikowski, Albert; Pellin, Michael; Yacout, Abdellatif

    2017-03-01

    A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials. Material scientists will be able to use the measured material parameters to validate computer simulation codes and extrapolate the response of the material in a nuclear reactor environment. Utilizing a new heavy-ion accelerator will provide the appropriate energies and intensities to study these effects with beam intensities which allow experiments to run over hours or days instead of years. The XMAT facility will use a CW heavy-ion accelerator capable of providing beams of any stable isotope with adjustable energy up to 1.2 MeV/u for U-238(50+) and 1.7 MeV for protons. This energy is crucial to the design since it well mimics fission fragments that provide the major portion of the damage in nuclear fuels. The energy also allows damage to be created far from the surface of the material allowing bulk radiation damage effects to be investigated. The XMAT ion linac includes an electron cyclotron resonance ion source, a normal-conducting radio-frequency quadrupole and four normal-conducting multi-gap quarter-wave resonators operating at 60.625 MHz. This paper presents the 3D multi-physics design and analysis of the accelerating structures and beam dynamics studies of the linac.

  10. Heavy ion linear accelerator for radiation damage studies of materials

    Science.gov (United States)

    Kutsaev, Sergey V.; Mustapha, Brahim; Ostroumov, Peter N.; Nolen, Jerry; Barcikowski, Albert; Pellin, Michael; Yacout, Abdellatif

    2017-03-01

    A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials. Material scientists will be able to use the measured material parameters to validate computer simulation codes and extrapolate the response of the material in a nuclear reactor environment. Utilizing a new heavy-ion accelerator will provide the appropriate energies and intensities to study these effects with beam intensities which allow experiments to run over hours or days instead of years. The XMAT facility will use a CW heavy-ion accelerator capable of providing beams of any stable isotope with adjustable energy up to 1.2 MeV/u for 238U50+ and 1.7 MeV for protons. This energy is crucial to the design since it well mimics fission fragments that provide the major portion of the damage in nuclear fuels. The energy also allows damage to be created far from the surface of the material allowing bulk radiation damage effects to be investigated. The XMAT ion linac includes an electron cyclotron resonance ion source, a normal-conducting radio-frequency quadrupole and four normal-conducting multi-gap quarter-wave resonators operating at 60.625 MHz. This paper presents the 3D multi-physics design and analysis of the accelerating structures and beam dynamics studies of the linac.

  11. Structural and electrical properties of swift heavy ion beam irradiated ...

    Indian Academy of Sciences (India)

    TECS

    Abstract. The present work deals with the mixing of iron and silicon by swift heavy ions in high-energy range. The thin film was deposited on a n-Si (111) substrate at 10. –6 torr and at room temperature. Irradia- tions were undertaken at room temperature using 120 MeV Au. +9 ions at the Fe/Si interface to investigate ion.

  12. Heavy-ion Results of the CMS Experiment

    CERN Document Server

    Boimska, B

    2016-01-01

    An overview of selected heavy-ion results of the CMS experiment is presented. Jet quenching, quarkonia suppression and two-particle angular correlation results are discussed. The measurements have been performed for lead–lead, proton–lead and proton–proton data samples recorded for Run 1 of the LHC accelerator. In the correlation analysis, low pile-up proton–proton collisions at an energy of 13 TeV (from Run 2) have been used as well

  13. Thermalization in the initial stage of heavy ion collisions

    Directory of Open Access Journals (Sweden)

    Zhu Yan

    2017-01-01

    Full Text Available The high density non-abelian matter produced in heavy ion collisions is extremely anisotropic. Prethermal dynamics for the anisotropic and weakly coupled matter is discussed. Thermalization is realized with the effective kinetic theory in the leading order accuracy of the weakly coupled expansion. With the initial condition from color glass condensate, hydrodynamization time for the LHC energies is realized to be about 1 fm/c, while the thermalization happens much later than the hydrodynamization.

  14. Results from the first heavy ion run at the LHC

    CERN Document Server

    Schukraft, J

    2012-01-01

    Early November 2010, the LHC collided for the first time heavy ions, Pb on Pb, at a centre-of-mass energy of 2.76 TeV/nucleon. This date marked both the end of almost 20 years of preparing for nuclear collisions at the LHC, as well as the start of a new era in ultra-relativistic heavy ion physics at energies exceeding previous machines by more than an order of magnitude. This contribution summarizes some of the early results from all three experiments participating in the LHC heavy ion program (ALICE, ATLAS, and CMS), which show that the high density matter created at the LHC, while much hotter and larger, still behaves like the very strongly interacting, almost perfect liquid discovered at RHIC. Some surprising and even puzzling results are seen in particle ratios, jet-quenching, and Quarkonia suppression observables. The overall experimental conditions at the LHC, together with its set of powerful and state-of-the-art detectors, should allow for precision measurements of quark-gluon-plasma parameters like v...

  15. Mutagenic effects of heavy ion radiation in plants

    Science.gov (United States)

    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. Results from the first heavy ion run at the LHC

    Science.gov (United States)

    Schukraft, J.

    2012-09-01

    Early November 2010, the LHC collided for the first time heavy ions, Pb on Pb, at a centre-of-mass energy of 2.76 TeV/nucleon. This date marked both the end of almost 20 years of preparing for nuclear collisions at the LHC, as well as the start of a new era in ultra-relativistic heavy ion physics at energies exceeding previous machines by more than an order of magnitude. This contribution summarizes some of the early results from all three experiments participating in the LHC heavy ion program (ALICE, ATLAS, and CMS), which show that the high density matter created at the LHC, while much hotter and larger, still behaves like the very strongly interacting, almost perfect liquid discovered at RHIC. Some surprising and even puzzling results are seen in particle ratios, jet-quenching, and Quarkonia suppression observables. The overall experimental conditions at the LHC, together with its set of powerful and state-of-the-art detectors, should allow for precision measurements of quark-gluon-plasma parameters like viscosity and opacity.

  17. Heavy-ion performance of the LHC and future colliders

    CERN Document Server

    AUTHOR|(SzGeCERN)696614; Stahl, Achim; Jowett, John M

    2015-10-09

    In 2008 the Large Hadron Collider (LHC) and its experiments started operation at the European Centre of Nuclear Research (CERN) in Geneva with the main aim of finding or excluding the Higgs boson. Only four years later, on the 4th of July 2012, the discovery of a Higgs-like particle was proven and first published by the two main experiments ATLAS and CMS. Even though proton–proton collisions are the main operation mode of the LHC, it also acts as an heavy-ion collider. Here, the term “heavy-ion collisions” refers to the collision between fully stripped nuclei. While the major hardware system of the LHC is compatible with heavy-ion operation, the beam dynamics and performance limits of ion beams are quite different from those of protons. Because of the higher mass and charge of the ions, beam dynamic effects like intra-beam scattering and radiation damping are stronger. Also the electromagnetic cross-sections in the collisions are larger, leading to significantly faster intensity decay and thus shorter l...

  18. Preliminary results from the heavy ions in space experiment

    Science.gov (United States)

    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.

  19. Proceedings of the workshop on prospects for research with radioactive beams from heavy ion accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Nitschke, J.M. (ed.)

    1984-04-01

    The SuperHILAC Users Executive Committee organized a workshop on Prospects for Research with Radioactive Beams from Heavy Ion Accelerators. The main purpose of the workshop was to bring together a diverse group of scientists who had already done experients with radioactive beams or were interested in their use in the future. The topics of the talks ranged from general nuclear physics, astrophysics, production of radioactive beams and high energy projectile fragmentation to biomedical applications. This publication contains the abstracts of the talks given at the workshop and copies of the viewgraphs as they were supplied to the editor.

  20. Experimental studies of single-event effects induced by heavy ions

    Science.gov (United States)

    Liu, J.; Hou, M. D.; Li, B. Q.; Liu, C. L.; Wang, Z. G.; Cheng, S.; Sun, Y. M.; Jin, Y. F.; Lin, Y. L.; Cai, J. R.; Wang, S. J.; Ye, Z. H.; Zhu, G. W.; Du, H.; Ren, Q. Y.; Wu, W.; Mao, X. M.; Sun, Y. Q.; Guo, R.

    2000-04-01

    This paper presents the results of ground-based heavy ion test of single-event effect (SEE) vulnerability on microcircuits used in space. We observed the dependence of upset cross-sections on the incident angle of ions in Intel 8086 CPU. SEU cross-sections of various SRAMs did not depend on the stored pattern, but 0→1 and 1→0 transitions were completely different for different manufacturer products. Some SEE protection methods were verified in conditions of ground simulation experiments.

  1. Production cross section of At radionuclides from 7Li+natPb and 9Be+natTl reactions

    Science.gov (United States)

    Maiti, Moumita; Lahiri, Susanta

    2011-12-01

    Earlier we reported theoretical studies on the probable production of astatine radionuclides from 6,7Li- and 9Be-induced reactions on natural lead and thallium targets, respectively. The production of astatine radionuclides were investigated experimentally with two heavy-ion-induced reactions: 9Be + natTl and 7Li + natPb. Formation cross sections of the evaporation residues, 207,208,209,210At, produced in the (HI,xn) channel, were measured by the stacked-foil technique followed by off-line γ spectrometry at low incident energies (<50 MeV). Measured excitation functions were interpreted in terms of a compound nuclear reaction mechanism using Weisskopf-Ewing and Hauser-Feshbach models. Measured cross-section values are lower than the respective theoretical predictions.

  2. A 3-year plan for beam science in the heavy-ion fusion virtual national laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Logan, B. Grant

    2001-09-10

    In December 1998, LBNL Director Charles Shank and LLNL Director Bruce Tarter signed a Memorandum of Agreement to create the Heavy-Ion Fusion Virtual National Laboratory (HIF-VNL) with the purpose of improving the efficiency and productivity of heavy ion research through coordination of the two laboratories' efforts under one technical director. In 1999, PPPL Director Robert Goldston signed the VNL MOA for PPPL's heavy-ion fusion group to join the VNL. LBNL and LLNL each contribute about 45% of the $10.6 M/yr trilab VNL effort, and PPPL contributes currently about 10% of the VNL effort. The three labs carry out collaborative experiments, theory and simulations of a variety of intense beam scientific issues described below. The tri-lab HIF VNL program is part of the DOE Office of Fusion Energy Sciences (OFES) fusion program. A short description of the four major tasks areas of HIF-VNL research is given in the next section. The task areas are: High Current Experiment, Final Focus/Chamber Transport, Source/Injector/Low Energy Beam Transport (LEBT), and Theory/Simulation. As a result of the internal review, more detailed reviews of the designs, costs and schedules for some of the tasks have been completed, which will provide more precision in the scheduled completion dates of tasks. The process for the ongoing engineering reviews and governance for the future management of tasks is described in section 3. A description of the major milestones and scientific deliverables for flat guidance budgets are given in section 4. Section 5 describes needs for enabling technology development for future experiments that require incremental funding.

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

    CERN Document Server

    Schukraft, J

    2012-01-01

    After close to 20 years of preparation, the dedicated heavy ion experiment ALICE took first data at the CERN 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 pp and nucleus-nucleus reactions, in the new energy regime of LHC. The pp results differ, to a varying degree, from most QCD 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 LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect...

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

    Science.gov (United States)

    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.

  5. From molecules to rainbows and Airy structures in light heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Haas, F.; Nicoli, M.P.; Freeman, R.M. [Inst. de Rech. Subatomiques, CNRS-IN2P3/ULP, Strasbourg (France); Szilner, S.; Basrak, Z. [Ruder Boskovic Institute HR-10 001 Zagreb (Croatia); Morsad, A. [Universite Hassan II, Casablanca (Morocco); Brandan, M.E. [Instituto de Fisica, UNAM (Mexico); Satchler, G.R. [University of Tennessee Knoxville and Oak Ridge National Laboratory (United States)

    2001-09-01

    Full text: Heavy ion interactions are usually dominated by strong absorption. This is not the case for certain light heavy ion collisions where the number of open channels is small and the absorption weak. Consequently, resonance phenomena are observed in these systems at bombarding energies lower than {approx} 5 MeV per nucleon. At higher energies, the weak absorption results in the observation of refractive effects which are very important to determine the nucleus-nucleus potential. In the present study, the refractive effects have been searched for in {sup 12} C + {sup 12} C, {sup 16} O + {sup 16} O, {sup 12} C + {sup 16} O and {sup 12} C + {sup 18} O reactions where the exit binary channels have been measured at several laboratory energies between 5 and 10 MeV per nucleon. The experiments have been performed at the Strasbourg Vivitron accelerator in the bombarding energy range where the reported experimental results are rather scarce. Detailed elastic scattering angular distributions up to large angles (crucial for the refractive effects) have been obtained. Their optical model analysis allowed to extract rather unique potentials which have strongly attractive real parts and relatively weakly absorbing imaginary parts. The energy and system dependence of the obtained potentials have been established. The elastic scattering angular distributions not only show the usual Fraunhofer diffraction pattern but also, at larger angles, refractive effects under the form of the nuclear rainbow Airy structures. For the systems studied, the existence and properties of the Airy minima will be discussed. (Author)

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

    Science.gov (United States)

    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.

  7. Fusion cross section measurements of astrophysical interest for light heavy ions systems within the STELLA project

    Science.gov (United States)

    Fruet, Guillaume; Courtin, Sandrine; Jenkins, David G.; Heine, Marcel; Montanari, Daniele; Morris, Luke G.; Adsley, Philip; Beck, Christian; Della Negra, Serge; Haas, Florent; Hammache, Fairouz; Kirsebom, Oliver S.; Meyer, Anne; Regan, Patrick H.; Rudiger, Matthias; de Séréville, Nicolas; Stodel, Christelle

    2017-11-01

    This contribution is focused on the STELLA project (STELlar LAboratory), which aims at the measurement of fusion cross sections between light heavy ions like 12C+12C, 12C+16O or 16O+16O at deep subbarrier energies. The gamma-particle coincidence technique is used in order to reduce background contributions that become dominant for measurements in the nanobarn regime. The experimental setup composed of an ultra high vacuum reaction chamber, a set of 3 silicon strip detectors, up to 36 LaBr3(Ce) scintillators from the UK FATIMA collaboration, and a fast rotating target system will be described. The 12C+12C fusion reaction has been studied from Elab = 11 to 5.6 MeV using STELLA at the Andromède facility in Orsay, France. Preliminary commissioning results are presented in this article.

  8. Isotropization and hydrodynamization in weakly coupled heavy-ion collisions

    CERN Document Server

    Kurkela, Aleksi

    2015-01-01

    We numerically solve 2+1D effective kinetic theory of weak coupling QCD under longitudinal expansion relevant for early stages of heavy-ion collisions. We find agreement with viscous hydrodynamics and classical Yang-Mills simulations in the regimes where they are applicable. By choosing initial conditions that are motivated by color-glass-condensate framework we find that for Q=2GeV and $\\alpha_s$=0.3 the system is approximately described by viscous hydrodynamics well before $\\tau \\lesssim 1.0$ fm/c.

  9. Status report on the Holifield Heavy Ion Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.M.; Alton, G.D.; Ball, J.B.; Benjamin, J.A.; Biggerstaff, J.A.; Erb, K.A.; Hudson, E.D.; Juras, R.C.; Kloeppel, P.K.; Lord, R.S. (Oak Ridge National Lab., TN (USA))

    1984-02-15

    The Holifield Heavy Ion Research Facility has been in routine operation since July, 1982. Beams have been provided using both the tandem accelerator alone and a coupled mode in which the Oak Ridge Isochronous Cyclotron is used as an energy booster for tandem beams. The coupled mode has proved to be especially effective and has allowed us to provide a wide range of energetic beams for scheduled experiments. In this report we will discuss the status of the tandem accelerator and some aspects of our experience with coupled operation.

  10. Status report on the holifield heavy ion research facility

    Science.gov (United States)

    Jones, C. M.; Alton, G. D.; Ball, J. B.; Benjamin, J. A.; Biggerstaff, J. A.; Erb, K. A.; Hudson, E. D.; Juras, R. C.; Kloeppel, P. K.; Lord, R. S.; Ludemann, C. A.; Mann, J. E.; Martin, J. A.; Mosko, S. W.; Richardson, E. G.; Sayer, R. O.; Ziegler, N. F.

    1984-02-01

    The Holifield Heavy Ion Research Facility has been in routine operation since July, 1982. Beams have been provided using both the tandem accelerator alone and a coupled mode in which the Oak Ridge Isochronous Cyclotron is used as an energy booster for tandem beams. The coupled mode has proved to be especially effective and has allowed us to provide a wide range of energetic beams for scheduled experiments. In this report we will discuss the status of the tandem accelerator and some aspects of our experience with coupled operation.

  11. Medical applications of nuclear physics and heavy-ion beams

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Studies on stochastic cooling of heavy ions in the LHC

    CERN Document Server

    Schaumann, M; Salvant, B; Wendt, M; Blaskiewicz, M; Verdú-Andrés, S

    2014-01-01

    Future high luminosity heavy-ion operation of the LHC will be dominated by very rapid luminosity decay due to the large collision cross-section and, to a lesser extent, emittance growth from intra-beam scattering (IBS) due to the high bunch intensities. A stochastic cooling system could reduce the emittance far below its initial value and reduce the losses from debunching during collisions, allowing more of the initial beam intensity to be converted into integrated luminosity before the beams are dumped. We review the status of this proposal, system and hardware properties and potential locations for the equipment in the tunnel.

  13. Data acquisition for the HILI (Heavy Ion Light Ion) detector

    Energy Technology Data Exchange (ETDEWEB)

    Teh, K.M.; Shapira, D.; McConnell, J.W.; Kim, H.; Novotny, R.

    1987-01-01

    A large acceptance, multi-segmented detector system capable of the simultaneous detection of heavy and light ions has been constructed. The heavy ions are detected with a segmented gas ionization chamber and a multiwire proportional counter while the light ions are detected with a 192 element plastic phoswich hodoscope. Processing the large number of signals is accomplished through a combination of CAMAC and FASTBUS modules and preprocessors, and a Host minicomputer. Details of the data acquisition system and the reasons for adopting a dual standards system are discussed. In addition, a technique for processing signals from an individual hodoscope detector is presented. 4 refs., 3 figs.

  14. Microchannel plate based detector for a heavy ion beam spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.I.

    1979-10-01

    The design parameters and operating characteristics of the detector used in the Brutus and Fannie heavy ion beam spectrometers at the SuperHILAC facility are described. The detector utilizes a 25 mm diameter microchannel plate array to obtain gains of 10/sup 2/ to 10/sup 8/ with a linear dynamic range of 10/sup 3/. It has had over three years of almost maintenance-free service, detecting ion beams from carbon to xenon with energies between 1.2 and 8.5 MeV per nucleon.

  15. Initial operation of the Argonne superconducting heavy-ion linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K. W.

    1979-01-01

    Initial operation and recent development of the Argonne superconducting heavy-ion linac are discussed. The linac has been developed in order to demonstrate a cost-effective means of extending the performance of electrostatic tandem accelerators. The results of beam acceleration tests which began in June 1978 are described. At present 7 of a planned array of 22 resonators are operating on-line, and the linac system provides an effective accelerating potential of 7.5 MV. Although some technical problems remain, the level of performance and reliability is sufficient that appreciable beam time is becoming available to users.

  16. Influence of heavy ion implantation on the microhardness of lif

    CERN Document Server

    Abu-Alazm, S M

    2003-01-01

    The paper presented microhardness measurements for pure lithium fluoride (LiF) implanted with Ar, Kr and Xe at doses ranged from 10 sup 9 up to 10 sup 1 2 ion/cm sup 2. Measurements were also performed for the microhardness after irradiation by electron and gamma rays. The data exhibited a large increase of microhardness of LiF using heavy ions in comparison with the unimplanted and irradiated samples with electrons and gamma rays. The influence of annealing the samples on the microhardness is also studied. The obtained results were interpreted according to the formation of F-centers in LiF.

  17. High Current Ion Sources and Injectors for Heavy Ion Fusion

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Neutron-induced reaction cross-section measurements using a ...

    Indian Academy of Sciences (India)

    Abstract. The experimental setup of Louvain-la-Neuve (UCL-Belgium) used to perform light- charged particle production experiment in fast neutron-induced reactions is presented. A short de- scription of the neutron modular detector DEMON is also given. DEMON is a detector array for neutrons emitted in heavy ion induced ...

  19. PREFACE: Heavy-Ion Spectroscopy and QED Effects in Atomic Systems

    Science.gov (United States)

    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

  20. D-meson production in p-Pb collisions at $\\sqrt{s_{\\rm NN}}=5.02$ TeV and in pp collisions at $\\sqrt{s}=7$ TeVsu

    OpenAIRE

    Adam, J.; Adamova, D.; Aggarwal, M.M.(Panjab University, Chandigarh, 160014, India); Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; S.U. Ahn; Aiola, S.; Akindinov, A; S.N. Alam; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; D. Alexandre

    2016-01-01

    Background: In the context of the investigation of the quark gluon plasma produced in heavy-ion collisions, hadrons containing heavy (charm or beauty) quarks play a special role for the characterization of the hot and dense medium created in the interaction. The measurement of the production of charm and beauty hadrons in proton-proton collisions, besides providing the necessary reference for the studies in heavy-ion reactions, constitutes an important test of perturbative quantum chromodynam...

  1. Design of 57.5 MHz cw RFQ for medium energy heavy ion superconducting linac

    Directory of Open Access Journals (Sweden)

    P. N. Ostroumov

    2002-06-01

    Full Text Available The nuclear science community considers the construction of the Rare Isotope Accelerator (RIA facility as a top priority. The RIA includes a 1.4 GV superconducting linac for production of 400 kW cw heavy ion beams. The initial acceleration of heavy ions delivered from an electron cyclotron resonance ion source can be effectively performed by a 57.5 MHz 4-m long room temperature RFQ. The principal specifications of the RFQ are (i formation of extremely low longitudinal emittance, (ii stable operation over a wide range of voltage for acceleration of various ion species needed for RIA operation, and (iii simultaneous acceleration of two-charge states of uranium ions. cw operation of an accelerating structure leads to a number of requirements for the resonators such as high shunt impedance, efficient water cooling of all parts of the resonant cavity, mechanical stability together with precise alignment, reliable rf contacts, a stable operating mode, and fine tuning of the resonant frequency during operation. To satisfy these requirements a new resonant structure has been developed. This paper discusses the beam dynamics and electrodynamics design of the RFQ cavity, as well as some aspects of the mechanical design of the low-frequency cw RFQ.

  2. Modeling of single event gate rupture in power MOSFETs under heavy ion irradiation

    Science.gov (United States)

    Useinov, R. G.; Zebrev, G. I.; Emelyanov, V. V.; Vatuev, A. S.

    2014-12-01

    Destructive single event gate rupture (SEGR) occurring in the gate oxides of power MOSFETs under impact of heavy ions is studied and modeled. SEGR cross section of power MOSFET with 70 nm oxide thickness as function of gate voltage was measured for four types of heavy ions. A predictive formula for the SEGR cross section is derived and validated. This formula can be used as a predictive instrument for computation of survival probability in a given spectrum of heavy ions in space environments.

  3. Time Dependence of Chemical Freeze-out in Relativistic Heavy Ion Collisions

    CERN Document Server

    Bellwied, R; Humanic, T J

    2000-01-01

    We investigate chemical and thermal freeze-out time dependencies for strange particle production for CERN SPS heavy ion collisions in the framework of a dynamical hadronic transport code. We show that the Lambda yield changes considerably after hadronization in the case of Pb+Pb collisions, whereas for smaller system sizes (e.g. S+S) the direct particle production dominates over production from inelastic rescattering. Chemical freeze-out times for strange baryons in Pb+Pb are smaller than for non-strange baryons, but they are still sufficiently long for hadronic rescattering to contribute significantly to the final Lambda yield. Based on inelastic and elastic cross section estimates we expect the trend of shorter freeze-out times (chemical and kinetic), and thus less particle production after hadronization, to continue for multi-strange baryons.

  4. Dislocation loop formation by swift heavy ion irradiation of metals

    Science.gov (United States)

    Khara, Galvin S.; Murphy, Samuel T.; Duffy, Dorothy M.

    2017-07-01

    A coupled two-temperature, molecular dynamics methodology is used to simulate the structural evolution of bcc metals (Fe and W) and fcc metals (Cu and Ni) following irradiation by swift heavy ions. Electronic temperature dependent electronic specific heat capacities and electron-phonon coupling strengths are used to capture the full effects of the variation in the electronic density of states. Tungsten is found to be significantly more resistant to damage than iron, due both to the higher melting temperature and the higher thermal conductivity. Very interesting defect structures, quite different from defects formed in cascades, are found to be created by swift heavy ion irradiation in the bcc metals. Isolated vacancies form a halo around elongated interstitial dislocation loops that are oriented along the ion path. Such configurations are formed by rapid recrystallization of the molten cylindrical region that is created by the energetic ion. Vacancies are created at the recrystallization front, resulting in excess atoms at the core which form interstitial dislocation loops on completion of crystallization. These unique defect structures could, potentially, be used to create metal films with superior mechanical properties and interesting nanostructures.

  5. Characterization of swift heavy ion irradiation damage in ceria

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Characterization of swift heavy ion irradiation damage in ceria

    Energy Technology Data Exchange (ETDEWEB)

    Yablinsky, Clarissa A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Devanathan, Ram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pakarinen, Janne [Inst. for Nuclear Research Center (SCK-CEN), Mol, (Belgium); Gan, Jian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Severin, Daniel [GSI-Darmstadt (Germany); Trautmann, Christina [GSI-Darmstadt (Germany); Allen, Todd R. [Univ. of Wisconsin, Madison, WI (United States). Energy Physics Dept.

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, R.P. [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Hareesh, K., E-mail: appi.2907@gmail.com [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Bankar, A. [Department of Microbiology, Waghire College, Pune 412301 (India); Sanjeev, Ganesh [Microtron Centre, Department of Studies in Physics, Mangalore University, Mangalore 574166 (India); Asokan, K.; Kanjilal, D. [Inter University Accelerator Centre, Arun Asaf Ali Marg, New Delhi 110067 (India); Dahiwale, S.S.; Bhoraskar, V.N. [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India)

    2016-10-01

    Highlights: • PC films were irradiated by 60 and 120 MeV Fe ions. • Irradiated PC films showed changes in its physical and chemical properties. • Irradiated PC also showed more anti-biofilm activity compared to pristine PC. - Abstract: 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 × 10{sup 11} ions/cm{sup 2} to 1 × 10{sup 13} ions/cm{sup 2}. 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.

  8. Modeling chamber transport for heavy-ion fusion

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Solar wind heavy ions from energetic coronal events

    Energy Technology Data Exchange (ETDEWEB)

    Bame, S.J.

    1978-01-01

    Ions heavier than those of He can be resolved in the solar wind with electrostatic E/q analyzers when the local thermal temperatures are low. Ordinarily this condition prevails in the low speed solar wind found between high speed streams, i.e. the interstream, IS, solar wind. Various ions of O, Si and Fe are resolved in IS heavy ion spectra. Relative ion peak intensities indicate that the O ionization state is established in the IS coronal source regions at approx. 2.1 x 10/sup 6/K while the state of Fe is frozen in at approx. 1.5 x 10/sup 6/K farther out. Occasionally, anomalous spectra are observed in which the usually third most prominent ion peak, O/sup 8 +/, is depressed as are the Fe peaks ranging from Fe/sup 12 +/ to Fe/sup 7 +/. A prominent peak in the usual Si/sup 8 +/ position of IS spectra is self-consistently shown to be Fe/sup 16 +/. These features demonstrate that the ionization states were frozen in at higher than usual coronal temperatures. The source regions of these hot heavy ion spectra are identified as energetic coronal events including flares and nonflare coronal mass ejections. 24 references.

  10. Uniformity of fuel target implosion in Heavy Ion Fusion

    CERN Document Server

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

    2015-01-01

    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 he...

  11. The Heavy-Ion Physics Programme with the ATLAS Detector

    CERN Document Server

    Rosselet, L

    2008-01-01

    The CERN LHC will collide lead ions at $\\sqrt{s}=5.5$ TeV per nucleon pair and will provide crucial information about the formation of a quark--gluon plasma at the highest temperatures and densities ever created in the laboratory. We report on an updated evaluation of the ATLAS potential to study heavy--ion physics. The ATLAS detector will perform especially well for high $p_T$ phenomena even in the presence of the high--multiplicity soft background expected from lead-lead collisions, and most of the detector subsystems retain their nearly full capability. ATLAS will study a full range of observables which characterize the hot and dense medium formed in heavy--ion collisions. In addition to global measurements such as particle multiplicities and collective flow, heavy--quarkonia suppression, jet quenching and the modification of jets passing in the dense medium will be accessible. ATLAS will also study forward physics and ultraperipheral collisions using Zero Degree Calorimeters.

  12. The Heavy-Ion Physics Programme with the ATLAS Detector

    CERN Document Server

    Rosselet, L

    2008-01-01

    The CERN LHC will collide lead ions at sqrt(s)=5.5 TeV per nucleon pair and will provide crucial information about the formation of a quark gluon plasma at the highest temperatures and densities ever created in the laboratory. We report on an updated evaluation of the ATLAS potential to study heavy-ion physics. The ATLAS detector will perform especially well for high pT phenomena even in the presence of the high-multiplicity soft background expected from lead-lead collisions, and most of the detector subsystems retain their nearly full capability. ATLAS will study a full range of observables which characterize the hot and dense medium formed in heavy-ion collisions. In addition to global measurements such as particle multiplicities and collective flow, heavy-quarkonia suppression, jet quenching and the modification of jets passing in the dense medium will be accessible to ATLAS. ATLAS will also study forward physics and ultraperipheral collisions using Zero Degree Calorimeters.

  13. Heavy flavours production in quark-gluon plasma formed in high energy nuclear reactions

    Science.gov (United States)

    Kloskinski, J.

    1985-01-01

    Results on compression and temperatures of nuclear fireballs and on relative yield of strange and charmed hadrons are given . The results show that temperatures above 300 MeV and large compressions are unlikely achieved in average heavy ion collision. In consequence, thermal production of charm is low. Strange particle production is, however, substantial and indicates clear temperature - threshold behavior.

  14. Can van Hove singularities be observed in relativistic heavy-ion ...

    Indian Academy of Sciences (India)

    Keywords. Perturbative quantum chromodynamics; hard thermal loop; gluon condensate; quark–gluon plasma; dispersion relation; collective modes; van Hove singularity; relativistic heavy-ion collisions.

  15. Biological and medical research with accelerated heavy ions at the Bevalac, 1974--1977. [Planning for use for radiotherapy and as radiation source for diagnostic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Elam, S. (ed.)

    1977-04-01

    The Bevalac, a versatile high-energy heavy-ion accelerator complex, has been in operation for less than two years. A major purpose for which the Bevalac was constructed was to explore the possibility of heavy-ion teams for therapy for certain forms of cancer. Significant progress has been made in this direction. The National Cancer Institute has recognized the advantages that these and other accelerated particles offer, and heavy ions have been included in a long-term plan for particle therapy that will assess by means of controlled therapeutic tests the value of various modalities. Since accelerated heavy ions became available, the possibility of other contributions, not planned, became apparent. We are developig a new diagnostic method known as heavy-ion radiography that has greatly increased sensitivity for soft-tissue detail and that may become a powerful tool for localizing early tumors and metastases. We have discovered that radioactive beams are formed from fragmentation of stable deflected beams. Use of these autoradioactive beams is just beginning; however, we know that these beams will be helpful in localizing the region in the body where therapy is being delivered. In addition, it has been demonstrated that instant implantation of the radioactive beam allows direct measurements of blood perfusion rates in inaccessible parts of the body, and such a technique may become a new tool for the study of fast hot atom reactions in biochemistry, tracer biology and nuclear medicine. The Bevalac will also be useful for the continuation of previously developed methods for the control of acromegaly, Cushing's disease and, on a research basis, advanced diabetes mellitus with vascular disease. The ability to make small bloodless lesions in the brain and elsewhere with heavy-ion beams has great potential for nervous-system studies and perhaps later for radioneurosurgery.

  16. Quarkonia measurements in 5 TeV heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Smirnov, Nikita; The ATLAS collaboration

    2017-01-01

    The in-medium suppression of heavy quarkonia production in heavy-ion collisions, with respect to proton-proton collisions, serves as a sensitive probe for studying the QGP. A full assessment of the suppression requires understanding of hot and cold nuclear matter effects using A-A and smaller sized p-A collision systems, respectively. Based on proton-lead collision data collected in 2013 and proton-proton and lead-lead collision data collected in 2015 at the LHC, it is possible to study J/psi, psi(2S) and Upsilon(nS) production using the ATLAS detector. The charmonium states are further separated into contributions from B-hadron decays and prompt production to study effects of charmonium suppression for B-hardons traversing the hot medium. Several measurements such as nuclear modification factors and excited-to-ground state ratios will be presented in this talk.

  17. Effects of radical scavengers on aqueous solutions exposed to heavy-ion irradiation using the liquid microjet technique

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Shinji [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Tsuchida, Hidetsugu, E-mail: tsuchida@nucleng.kyoto-u.ac.jp [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan); Furuya, Ryousuke; Miyahara, Kento [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Majima, Takuya; Itoh, Akio [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan)

    2015-12-15

    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.

  18. Event-shape-engineering study of charge separation in heavy-ion collisions

    Science.gov (United States)

    Wen, Fufang; Bryon, Jacob; Wen, Liwen; Wang, Gang

    2018-01-01

    Recent measurements of charge-dependent azimuthal correlations in high-energy heavy-ion collisions have indicated charge-separation signals perpendicular to the reaction plane, and have been related to the chiral magnetic effect (CME). However, the correlation signal is contaminated with the background caused by the collective motion (flow) of the collision system, and an effective approach is needed to remove the flow background from the correlation. We present a method study with simplified Monte Carlo simulations and a multi-phase transport model, and develop a scheme to reveal the true CME signal via event-shape engineering with the flow vector of the particles of interest. Supported by a grant (DE-FG02-88ER40424) from U.S. Department of Energy, Office of Nuclear Physics

  19. Recent Improvements of Particle and Heavy Ion Transport code System: PHITS

    Science.gov (United States)

    Sato, Tatsuhiko; Niita, Koji; Iwamoto, Yosuke; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shin-ichiro; Kai, Takeshi; Matsuda, Norihiro; Okumura, Keisuke; Kai, Tetsuya; Iwase, Hiroshi; Sihver, Lembit

    2017-09-01

    The Particle and Heavy Ion Transport code System, PHITS, has been developed under the collaboration of several research institutes in Japan and Europe. This system can simulate the transport of most particles with energy levels up to 1 TeV (per nucleon for ion) using different nuclear reaction models and data libraries. More than 2,500 registered researchers and technicians have used this system for various applications such as accelerator design, radiation shielding and protection, medical physics, and space- and geo-sciences. This paper summarizes the physics models and functions recently implemented in PHITS, between versions 2.52 and 2.88, especially those related to source generation useful for simulating brachytherapy and internal exposures of radioisotopes.

  20. Reaction products of chlorine dioxide.

    Science.gov (United States)

    Stevens, A A

    1982-01-01

    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxide treatment of organic materials are oxidized species, some of which also contain chlorine. The relative amounts of species types may depend on the amount of chlorine dioxide residual maintained and the concentration and nature of the organic material present in the source water. The trend toward lower concentrations of chlorinated by-products with increasing ClO2 concentration, which was observed with phenols, has not been observed with natural humic materials as measured by the organic halogen parameter. Organic halogen concentrations have been shown to increase with increasing chlorine dioxide dose, but are much lower than those observed when chlorine is applied. Aldehydes have been detected as apparent by-products of chlorine dioxide oxidation reactions in a surface water that is a drinking water source. Some other nonchlorinated products of chlorine dioxide treatment may be quinones and epoxides. The extent of formation of these moieties within the macromolecular humic structure is also still unknown. PMID:7151750

  1. Mutagenic effect of accelerated heavy ions on bacterial cells

    Science.gov (United States)

    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

  2. Investigations of heavy ion tracks in polyethylene naphthalate films

    CERN Document Server

    Starosta, W; Sartowska, B; Buczkowski, M

    1999-01-01

    The heavy ion beam (with fluence 3x10 sup 8 ion/cm sup 2) from a cyclotron has been used for irradiation of thin polyethylene naphthalate (PEN) films. Latent tracks in these polymeric films have been sensitized by UV radiation and then chemically etched in NaOH solution. The etching process parameters have been controlled by the electroconductivity method. After etching, parameters of samples have been examined by SEM and bubble point methods (Coulter[reg] Porometer II instrument). Results have shown good quality of PEN track membranes with pore sizes in the range: 0.1 - 0.5 mu m. The described procedure is known for thin polyethylene terephthalate (PET) films. Taking into consideration that PEN films have got better mechanical, thermal, gas barrier as well as better chemical resistance properties in comparison with PET films, the possibility of application of such membranes is much wider.

  3. High $p_{T}$ physics in the heavy ion era

    CERN Document Server

    Rak, Jan

    2013-01-01

    Aimed at graduate students and researchers in the field of high-energy nuclear physics, this book provides an overview of the basic concepts of large transverse momentum particle physics, with a focus on pQCD phenomena. It examines high $p_{T}$ probes of relativistic heavy-ion collisions and will serve as a handbook for those working on RHIC and LHC data analyses. Starting with an introduction and review of the field, the authors look at basic observables and experimental techniques, concentrating on relativistic particle kinematics, before moving onto a discussion about the origins of high $p_{T}$ physics. The main features of high $p_{T}$ physics are placed within a historical context and the authors adopt an experimental outlook, highlighting the most important discoveries leading up to the foundation of modern QCD theory. Advanced methods are described in detail, making this book especially useful for newcomers to the field.

  4. Velocity dependence of heavy-ion stopping below the maximum

    Energy Technology Data Exchange (ETDEWEB)

    Sigmund, P., E-mail: sigmund@sdu.dk [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark); Schinner, A. [Institut für Experimentalphysik, Johannes Kepler Universität, A-4040 Linz (Austria)

    2015-01-01

    In the slowing-down of heavy ions in materials, the standard description by Lindhard and Scharff assumes the electronic stopping cross section to be proportional to the projectile speed v up to close to a stopping maximum, which is related to the Thomas–Fermi speed v{sub TF}. It is well known that strict proportionality with v is rarely observed, but little is known about the systematics of observed deviations. In this study we try to identify factors that determine positive or negative curvature of stopping cross sections on the basis of experimental data and of binary stopping theory. We estimate the influence of shell structure of the target and of the equilibrium charge of the ion and comment the role of dynamic screening.

  5. Response of the pixel detector Timepix to heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Granja, Carlos, E-mail: carlos.granja@utef.cvut.cz [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Jakubek, Jan [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Koester, Ulli [Institute Laue Langevin, 6 rue Jules Horowitz, F-38042 Grenoble Cedex 9 (France); Platkevic, Michal; Pospisil, Stanislav [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic)

    2011-05-15

    The response of the pixel detector Timepix to ions in the 4-110 MeV kinetic energy range and A=3-136 mass range has been studied at the fission-fragment separator Lohengrin of the Institute Laue Langevin in Grenoble. Timepix detects single ions measuring their position, kinetic energy, and time of arrival. Heavy ions with energy above several tens of 10 MeV produce a distortion of the electronic pixel signal response which arises when the energy collected is, under conventional detector settings, of around {approx}1 MeV per pixel. This effect can be suppressed, and the detector energy range extended, by suitable pixel signal baseline and threshold levels, together with optimally low sensor chip bias voltage. Reasonable results are achieved within the range of ion mass and energy studied extending the linearity level of per pixel measured energy up to {approx}2 MeV.

  6. Volume ignition targets for heavy-ion inertial fusion

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Val, J.M.; Eliezer, S.; Piera, M. [Madrid Polytcehnical Univ. (Spain). Inst. of Nuclear Fusion

    1994-12-31

    Inertial confinement fusion (ICF) targets can be imploded by heavy-ion beams (HIBs) in order to obtain a highly compressed fuel microsphere. The hydrodynamic efficiency of the compression can be optimized by tuning the ablation process in order to produce the total evaporation of the pusher material by the end of the implosion. Such pusherless compressions produce very highly compressed targets for relatively short confinement times. However, these times are long enough for a fusion burst to take place, and burnup fractions of 30% and higher can be obtained if the volume ignition requirements are met. Numerical simulations demonstrate that targets of 1-mg DT driven by a few MJ can yield energy gains of over 70. Although direct drive is used in these simulations, the main conclusions about volume ignition are also applicable to indirect drive. (author).

  7. Deposition of molecular probes in heavy ion tracks

    CERN Document Server

    Esser, M

    1999-01-01

    By using polarized fluorescence techniques the physical properties of heavy ion tracks such as the dielectric number, molecular alignment and track radius can be traced by molecular fluorescence probes. Foils of poly(ethylene terephthalate) (PET) were used as a matrix for the ion tracks wherein fluorescence probes such as aminostyryl-derivatives can be incorporated using a suitable solvent, e.g. N,N'-dimethylformamide (DMF) as transport medium. The high sensitivity of fluorescence methods allowed the comparison of the probe properties in ion tracks with the virgin material. From the fluorescence Stokes shift the dielectric constants could be calculated, describing the dielectric surroundings of the molecular probes. The lower dielectric constant in the tracks gives clear evidence that there is no higher accommodation of the highly polar solvent DMF in the tracks compared with the virgin material. Otherwise the dielectric constant in the tracks should be higher than in the virgin material. The orientation of t...

  8. Heavy Ion Collisions at the dawn of the LHC era

    CERN Document Server

    Takahashi, J.

    2013-06-27

    This is a proceeding of the CERN Latin American School of High-Energy physics that took place in the beautiful city of Natal, northern Brazil, in March 2011. In this paper I present a review of the main topics associated with the study of Heavy Ion Collisions, intended for students starting or interested in the field. It is impossible to summarize in a few pages the large amount of information that is available today, after a decade of operations of the RHIC accelerator and the beginning of the LHC operations. Thus, I had to choose some of the results and theories in order to present the main ideas and goals. All results presented here are from publicly available references, but some of the discussions and opinions are my personal view, where I have made that clear in the text.

  9. A new QMD code for heavy-ion collisions

    Science.gov (United States)

    Kim, Kyungil; Kim, Youngman; Lee, Kang Seog

    2017-11-01

    We develop a new quantum molecular dynamics (QMD) type nuclear transport code to simulate heavy-ion collisions for RAON, a new accelerator complex under construction in Korea. At RAON, the rare isotope beams with energies from a few MeV/n to a few hundreds MeV/n will be utilized. QMD is one of the widely used theoretical methods and is useful for both theoretical and experimental purposes. We describe our QMD model with the numerical realization. The validity of the code is tested by comparing our simulation results with experimental data and also results from other transport codes in 197Au+197Au collisions at Elab = 90 - 120 MeV/n. Finally, we present a brief discussion on applicability and outlook of our code.

  10. The 2015 Heavy-Ion Run of the LHC

    CERN Document Server

    Jowett, John; Bruce, Roderik; Giovannozzi, Massimo; Hermes, Pascal; Höfle, Wolfgang; Lamont, Mike; Mertens, Tom; Redaelli, Stefano; Schaumann, Michaela; Uythoven, Jan; Wenninger, Jorg

    2016-01-01

    In late 2015 the LHC collided lead nuclei at a beam energy of 6.37 Z TeV, chosen to match the 5.02 TeV per colliding nucleon pair of the p-Pb collision run in 2013. In so doing, it surpassed its design luminosity by a factor of 2. Besides the higher energy, the operational configuration had a number of new features with respect to the previous Pb-Pb run at 3.5 Z TeV in 2011; unusual bunch patterns providing collisions in the LHCb experiment for the first time, luminosity levelling and sharing requirements, a vertical displacement of the interaction point in the ALICE experiment, and operation closer to magnet quench limits with mitigation measures. We present a summary of the commissioning and operation and what has been learned in view of future heavy-ion operation at higher luminosity.

  11. Beam-beam observations in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    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.

  12. Heavy ion collision evolution modeling with ECHO-QGP

    Science.gov (United States)

    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.

  13. Imprint reduction in rotating heavy ions beam energy deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bret, A., E-mail: antoineclaude.bret@uclm.es [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States); ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Piriz, A.R., E-mail: Roberto.Piriz@uclm.es [ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Tahir, N.A., E-mail: n.tahir@gsi.de [GSI Darmstadt, Plankstrasse 1, 64291 Darmstadt (Germany)

    2014-01-01

    The compression of a cylindrical target by a rotating heavy ions beam is contemplated in certain inertial fusion schemes or in heavy density matter experiments. Because the beam has its proper temporal profile, the energy deposition is asymmetric and leaves an imprint which can have important consequences for the rest of the process. In this paper, the Fourier components of the deposited ion density are computed exactly in terms of the beam temporal profile and its rotation frequency Ω. We show that for any beam profile of duration T, there exist an infinite number of values of ΩT canceling exactly any given harmonic. For the particular case of a parabolic profile, we find possible to cancel exactly the first harmonic and nearly cancel every other odd harmonics. In such case, the imprint amplitude is divided by 4 without any increase of Ω.

  14. Stopping of relativistic heavy ions in various media

    Science.gov (United States)

    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.

  15. Split ring resonator for the Argonne superconducting heavy ion booster

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Scheibelhut, C.H.; Benaroya, R.; Bollinger, L.M.

    1977-01-01

    A split-ring resonator for use in the ANL superconducting heavy-ion linac was constructed and is being tested. The electromagnetic characteristics of the 98-MHz device are the same as the unit described earlier, but the housing is formed of a new material consisting of niobium sheet explosively bonded to copper. The niobium provides the superconducting path and the copper conducts heat to a small area cooled by liquid helium. This arrangement greatly simplified the cryogenic system. Fabrication of the housing was relatively simple, with the result that costs have been reduced substantially. The mechanical stability of the resonator and the performance of the demountable superconducting joints are significantly better than for the earlier unit.

  16. Jets in heavy ion collisions with the ATLAS detector

    CERN Document Server

    Santos, Helena; The ATLAS collaboration

    2018-01-01

    Jets constitute a golden probe to study the quark gluon plasma produced in heavy ion collisions at the LHC. Being produced at the early stages of the collisions, they are expected to be modified as propagating through the hot and dense medium. A signature of the modification is the energy loss lowering the jet yields at a given transverse momentum. A factor of two suppression is observed in central Pb+Pb collisions with respect to pp collisions. Other signatures are the modification of the dijet momentum balance and the modification of fragmentation functions. This talk will present the currently available jet results from ATLAS in Run 2. The high statistical significance of this data sample collected by ATLAS in Run 2 allows precision measurements of these observables in a wide range of transverse momentum, centrality and rapidity intervals.

  17. Jet quenching in heavy-ion collisions with CMS

    CERN Document Server

    Lee, Yen-Jie

    2008-01-01

    The energy loss of fast partons traversing the strongly interacting matter produced in relativistic heavy-ion collisions is one of the most interesting observables to probe the nature of the produced medium. The collisional and radiative energy loss of the partons will modify the fragmentation functions depending on the path length in the medium. In this report, we present a detailed study of complete simulated $\\gamma$-jet events by the CMS detector at LHC in view of the expected modification of jet fragmentation functions in central collisions at $\\sqrt{s_{NN}} = 5.5$ TeV compared to the p+p case. Since the produced prompt photon does not interact strongly with the medium, the initial transverse energy of the fragmentation parton can be related to the photon transverse energy in $\\gamma$-jet events. This enables us to make precision measurements of the modification of the fragmentation function.

  18. Jets in heavy ion collisions with the ATLAS detector

    CERN Document Server

    Santos, Helena; The ATLAS collaboration

    2017-01-01

    Jets constitute a golden probe to study the quark gluon plasma produced in heavy ion collisions at the LHC. Being produced at the early stages of the collisions, they are expected to be modified as propagating through the hot and dense medium. A signature of the modification is the energy loss lowering the jet yields at a given transverse momentum. A factor of two suppression is observed in central Pb+Pb collisions with respect to pp collisions. Other signatures are the modification of the dijet momentum balance and the modification of fragmentation functions. This talk will present the currently available jet results from ATLAS in Run 2. The high statistical significance of this data sample collected by ATLAS in Run 2 allows precision measurements of these observables in a wide range of transverse momentum, centrality and rapidity intervals.

  19. Heavy-ion physics studies for the Future Circular Collider

    CERN Document Server

    Armesto, Nestor; d'Enterria, David; Masciocchi, Silvia; Roland, Christof; Salgado, Carlos; van Leeuwen, Marco; Wiedemann, Urs

    2014-01-01

    The Future Circular Collider (FCC) design study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode including proton and nucleus beams, more than seven-times larger than the nominal LHC energies. An electron-positron collider in the same tunnel is also considered as an intermediate step, which would provide the electron-hadron option in the long term. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of Quark-Gluon Plasma, gluon saturation, photon-induced collisions, as well as connections with ultra-high-energy cosmic rays.

  20. Heavy-ion physics studies for the Future Circular Collider

    Energy Technology Data Exchange (ETDEWEB)

    Armesto, N. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Dainese, A., E-mail: andrea.dainese@pd.infn.it [INFN — Sezione di Padova, 35131 Padova (Italy); D' Enterria, D. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland); Masciocchi, S. [EMMI and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Roland, C. [Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Salgado, C.A. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Leeuwen, M. van [Nikhef, National Institute for Subatomic Physics and Institute for Subatomic Physics of Utrecht University, Utrecht (Netherlands); Wiedemann, U.A. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland)

    2014-11-15

    The Future Circular Collider (FCC) design study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron–hadron collision mode including proton and nucleus beams, more than seven times larger than the nominal LHC energies. An electron–positron collider in the same tunnel is also considered as an intermediate step, which in the long term would allow for electron–hadron collisions. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of quark–gluon plasma, gluon saturation, photon-induced collisions, as well as connections with the physics of ultra-high-energy cosmic rays.

  1. Modelling early stages of relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Ruggieri M.

    2016-01-01

    Full Text Available 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.

  2. Production of very neutron-deficient isotopes near sup 1 sup 0 sup 0 Sn via reactions involving light-particle and cluster emission

    CERN Document Server

    La Commara, M; D'Onofrio, A; Gadea, A; Glogowski, M; Jarillo-Herrero, P; Belcari, N; Borcea, R; De Angelis, G; Fahlander, C; aGórska, M; Grawe, H; Hellström, M; Kirchner, R; Rejmund, M; Roca, V; Roeckl, E; Romano, M; Rykaczewski, K; Schmidt, K; Terrasi, F

    2000-01-01

    The production of very neutron-deficient isotopes near sup 1 sup 0 sup 0 Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete-fusion reactions. We measured the cross sections for sup 9 sup 9 Cd, sup 1 sup 0 sup 0 In, sup 1 sup 0 sup 1 Sn and sup 1 sup 0 sup 2 In via sup 5 sup 8 Ni+ sup 5 sup 8 Ni fusion reactions followed by cluster emission, and via sup 5 sup 8 Ni+ sup 5 sup 0 Cr fusion reactions accompanied by evaporation of protons, neutrons or alpha particles. Both types of reactions yield similar cross sections for the production of exotic nuclei near sup 1 sup 0 sup 0 Sn. The data are discussed in comparison with results obtained from statistical-model calculations.

  3. Heavy-Ion Radiation Impact on a 4Mb FRAM under Different Test Conditions

    CERN Document Server

    Gupta, V.; Tsiligiannis, G.; Zadeh, A.; Javanainen, A.; Virtanen, A.; Puchner, H.; Saigne, F.; Wrobel, F.; Dilillo, L.

    2015-01-01

    The impact of heavy-ions on commercial Ferroelectric Memories (FRAMs) is analyzed. The influence of different test modes (static and dynamic) on this memory is investigated. Static test results show that the memory is prone to temporary effects occurring in the peripheral circuitry. Dynamic tests results show a high sensitivity of this memory to heavy-ions.

  4. The initial stages of heavy-ion collisions in the colour glass ...

    Indian Academy of Sciences (India)

    collision at high energy in the colour glass condensate (CGC) framework. Keywords. Heavy-ion collisions; quantum chromodynamics; colour glass condensate. PACS Nos 12.38.Mh; 11.10.Wx; 12.38.Cy; 11.15.Kc; 12.38.Gc. 1. Introduction. Heavy-ion collisions at ultrarelativistic energies are used to study the properties of ...

  5. Review on heavy ion radiotherapy facilities and related ion sources (invited)

    NARCIS (Netherlands)

    Kitagawa, A.; Fujita, T.; Muramatsu, M.; Biri, S.; Drentje, A. G.

    Heavy ion radiotherapy awakens worldwide interest recently. The clinical results obtained by the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan have clearly demonstrated the advantages of carbon ion radiotherapy. Presently, there are four

  6. Jet Physics in Heavy Ion Collisions with Compact Muon Solenoid detector at the LHC

    CERN Document Server

    Lokhtin, I P

    2006-01-01

    The status of CMS jet simulations and physics analysis in heavy ion collisions is presented. Jet reconstruction and high transverse momentum particle tracking in the high multiplicity environment of heavy ion collisions at the LHC using the CMS calorimetry and tracking system are described. The Monte Carlo tools used to simulate jet quenching are discussed.

  7. Working group report: Heavy-ion physics and quark-gluon plasma

    Indian Academy of Sciences (India)

    This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.

  8. Study of transient current induced by heavy-ion microbeams in Si and GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Hirao, Toshio; Nashiyama, Isamu; Kamiya, Tomihiro; Suda, Tamotu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Heavy-ion microbeams were applied to the study of mechanism of single event upset (SEU). Transient current induced in p{sup +}n junction diodes by strike of heavy ion microbeam were measured by using a high-speed digitizing sampling system. (author)

  9. Prospects for parity-nonconservation experiments with highly charged heavy ions

    OpenAIRE

    Maul, Martin; Schäfer, Andreas; Greiner, Walter; Indelicato, Paul

    2006-01-01

    We discuss the prospects for parity-nonconservation experiments with highly charged heavy ions. Energy levels and parity mixing for heavy ions with 2–5 electrons are calculated. We investigate two-photon transitions and the possibility of observing interference effects between weak-matrix elements and Stark matrix elements for periodic electric field configurations.

  10. Prospects for Parity Non-conservation Experiments with Highly Charged Heavy Ions

    OpenAIRE

    Maul, M.; Schäfer, A.; Greiner, W.; Indelicato, P.

    1996-01-01

    We discuss the prospects for parity non-conservation experiments with highly charged heavy ions. Energy levels and parity mixing for heavy ions with two to five electrons are calculated. We investigate two-photon-transitions and the possibility to observe interference effects between weak-matrix elements and Stark matrix elements for periodic electric field configurations.

  11. Bremsstrahlung from relativistic bare heavy ions: Nuclear and electronic contributions in amorphous and crystalline materials

    DEFF Research Database (Denmark)

    Jensen, Tue Vissing; Sørensen, Allan Hvidkjær

    2013-01-01

    A charged particle emits bremsstrahlung while traversing matter. We calculate the radiation cross section for bare heavy ions penetrating amorphous materials and single crystals at highly relativistic energies. The main component originates in scattering of the virtual photons of screened target...... in a pronounced directional dependence of the energy loss of bare heavy ions at extreme relativistic energies....

  12. Effect of entrance channel parameters on the fusion of two heavy ions

    Indian Academy of Sciences (India)

    the charge state of the energetic heavy ions is important. The selected charge state of the energetic heavy ions might get modified when they traverse through the target foils. The average charge state of the ions emerging from the target ... high-spin isomer was considered to represent the cross-section of the radionuclide.

  13. MEGHNAD – A multi element detector array for heavy ion collision ...

    Indian Academy of Sciences (India)

    gamma, heavy ion and neutron array of detectors (MEGHNAD) to detect and study the properties of a wide variety of ... The gamma detector array consists of four numbers of Clover detectors, a few high efficiency HPGe ... chamber (IC) for measurement of energy and charge of the heavy ions stopping within the active gas ...

  14. Workshop on Heavy Ion Collisions at the LHC: Last Call for Predictions

    CERN Document Server

    Borghini, N; Akkelin, V; Alam, J; Albacete, J L; Andronic, A; Antonov, 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 W; Cleymans, J; Cole, B A; Conesa Del Valle, Z; Csernai, L P; Cunqueiro, L; Dainese, A; Dias de Deus, J; Ding, H T; Djordjevic, M; Drescher, H; Dremin, I M; Dumitru, A; El, A; Engel, R; d'Enterria, D; Eskola, K J; Fái, G; Ferreiro, E G; Fries, R J; Frodermann, E; Fujii, H; Gale, C; Gelis, François; Gonçalves, V P; Greco, V; Greiner, C; Gyulassy, M; Van Hees, H; Heinz, U; Honkanen, H; Horowitz, W A; Iancu, E; Ingelman, G; Jalilian-Marian, J; Jeon, S; Kaidalov, A B; Kämpfer, B; Kang, Z B; Karpenko, Iu 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 A; Lin, Z W; Liu, H; Liu, W; Loizides, C; Lokhtin, I P; Machado, M V T; Malinina, L V; Managadze, A M; Mangano, Michelangelo L; Mannarelli, M; Manuel, C; Martínez, G; Milhano, J G; Mocsy, A; Molnár, D; Nardi, M; Nayak, J K; Niemi, H; Oeschler, H; Ollitrault, J Y; 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 W; Rafelski, J; Rajagopal, K; Ranft, J; Rapp, R; Räasänen, 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; Shoshi, A I; Sinha, B; Sinyukov, Yu M; Snigirev, A M; Srivastava, D K; Stachel, J; Stasto, A; Stöcker, H; Teplov, C Yu; Thews, R L; Torrieri, G; Topor-Pop, V; 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, Urs Achim; Wolschin, G; Xiao, B W; Xu, Z; Yasui, S; Zabrodin, E; Zapp, K; Zhang, B; Zhang, B W; Zhang, H; Zhou, D

    2008-01-01

    This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last Call for Predictions', held from May 14th to June 10th 2007.

  15. Photon annd pion production in heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Blann, M.

    1989-05-01

    In this paper we describe different formulations for treating the nucleon-nucleon transport physics. These will all be semi-classical treatments; however considerable work has been done considering the relationship between quantal and semi-classical formulations. We discuss additional input specific to calculation of pion and photon yields, and present comparisons between calculated and experimental results, mostly for high energy photons. Conclusions and suggestions for future work are presented in the last section. 65 refs., 7 figs.

  16. Parity violation in the radiative electron capture of H-like heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Gunst, Jonas; Surzhykov, Andrey [Universitaet Heidelberg (Germany); GSI Helmholtzzentrum, Darmstadt (Germany)

    2012-07-01

    Measurements of parity-violation (PV) effects in atomic systems attract considerable attention as a valuable tool for testing of the Standard Model in the low-energy regime. In the past, however, most of these PV experiments have dealt with neutral atoms. Much less attention was paid to highly-charged heavy ions which are alternative and very promising candidates for atomic PV studies. Most of the proposals for PV-experiments with such heavy few-electron species still require the application of spin-polarized ion beams and/or of circular polarization x-ray measurements. These experimental tasks, however, cannot be easily accomplished today. In this contribution, therefore, we propose and discuss a new method for observing the PV effects in highly-charged ions. The method employs the measurement of a linear polarization of the photons emitted due to the radiative electron capture (REC) into the 1s 2p {sup 3}P{sub 0} state of unpolarized helium-like heavy ions. For such a scenario, significant mixing of opposite-parity levels 2 {sup 3}P{sub 0} and 2 {sup 1}S{sub 0} may manifest itself in the rotation of the polarization out of the reaction plane that can be observed by the present-day solid-state detectors. In order to describe this PV-induced rotation, a theoretical model has been developed within the framework of the density matrix approach and relativistic Dirac equation. Detailed calculations have been performed for relativistic collisions of unpolarized (initially) hydrogen-like Gadolinium ions with an electronic target.

  17. Study of the color effect in a quark-gluon plasma on the production rates of quarkonia in heavy ion collisions in the Phenix experiment; Etude de l'effet d'ecrantage de couleur dans un plasma de quarks et de gluons sur les taux de production des quarkonia dans les collisions d'ions lourds aupres de l'experience Phenix

    Energy Technology Data Exchange (ETDEWEB)

    Rakotozafindrabe, A

    2007-05-15

    This work deals with the measurement of the production of J/{psi} in Cu + Cu collisions at 200 GeV per nucleon pair via their decay channel into 2 muons. The experimental data used is that collected during the 2005 campaign at the RHIC. In the first chapter, we present the theoretical context of the study of quark-gluon plasmas (QGP) and its production in relativistic heavy ion collisions. The second chapter deals with the production of J/{psi} in proton-proton collisions and in case of light ion collisions where QGP can not be produced. The experimental setting is presented in the third chapter, particularly the muon spectrometer and the detectors whose purpose is to measure collision centrality. Data analysis concerning the extraction of the signal and the reconstruction of data is described in the fourth chapter. The method that has enabled us to extract the production of the J/{psi} as well as its uncertainties is detailed in the fifth chapter.

  18. Fluid dynamics with saturated minijet initial conditions in ultrarelativistic heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Paatelainen, R.; Eskola, K.J.; Niemi, H. [Department of Physics, PO Box 35, FI-40014 University of Jyväskylä (Finland); Helsinki Institute of Physics, PO Box 64, FI-00014 University of Helsinki (Finland); Tuominen, K. [Department of Physics, PO Box 64, FI-00014 University of Helsinki (Finland); Helsinki Institute of Physics, PO Box 64, FI-00014 University of Helsinki (Finland)

    2014-04-04

    Using next-to-leading order perturbative QCD and a conjecture of saturation to suppress the production of low-energy partons, we calculate the initial energy densities and formation times for the dissipative fluid dynamical evolution of the quark–gluon plasma produced in ultrarelativistic heavy-ion collisions. We identify the model uncertainties and demonstrate the predictive power of the approach by a good global agreement with the measured centrality dependence of charged particle multiplicities, transverse momentum spectra and elliptic flow simultaneously for the Pb+Pb collisions at the LHC and Au+Au at RHIC. In particular, the shear viscosity in the different phases of QCD matter is constrained in this new model simultaneously by all these data.

  19. Central collisions of heavy ions. Progress report, October 1, 1992--August 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Fung, Sun-yiu

    1993-08-01

    This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1992 to August 31, 1993. During this period, our AGS E802/E859/E866 experiments focused on strange particle production, and the fluctuation phenomenon associated with correlation studies in nucleus nucleus central collisions. We have designed and are implementing a new detector to replace the Target Multiplicity Array (TMA) for the E866 runs. As part of the PHENIX collaboration, we contributed to the Conceptual Design Report (CDR), and worked on a RHIC silicon microstrip detector R&D project, the central core of the multiplicity-vertex detector (MVD). In the coming year, we planned to complete the New Multiplicity Array (NMA) detector for the gold projectile E866 experiment, and analyzed the data associated with this new system. We are continuing our efforts in the preparation of the PHENIX detector system.

  20. Inclusive reconstruction of hadron resonances in elementary and heavy-ion collisions with HADES

    Directory of Open Access Journals (Sweden)

    Kornakov Georgy

    2016-01-01

    Full Text Available The unambiguous identification of hadron modifications in hot and dense QCD matter is one of the important goals in nuclear physics. In the regime of 1 - 2 GeV kinetic energy per nucleon, HADES has measured rare and penetrating probes in elementary and heavy-ion collisions. The main creation mechanism of mesons is the excitation and decay of baryonic resonances throughout the fireball evolution. The reconstruction of shortlived (≈ 1 fm/c resonance states through their decay products is notoriously difficult. We have developed a new iterative algorithm, which builds the best hypothesis of signal and background by distortion of individual particle properties. This allows to extract signals with signal-to-background ratios of <1%.