WorldWideScience

Sample records for heavy-ion reaction studies

  1. Heavy ion transfer reactions

    International Nuclear Information System (INIS)

    Weisser, D.C.

    1977-06-01

    To complement discussions on the role of γ rays in heavy ion induced reactions, the author discusses the role played by particle detection. Transfer reactions are part of this subject and are among those in which one infers the properties of the residual nucleus in a reaction by observing the emerging light nucleus. Inelastic scattering ought not be excluded from this subject, although no particles are transferred, because of the role it plays in multistep reactions and in fixing O.M. parameters describing the entrance channel of the reaction. Heavy ion transfer reaction studies have been under study for some years and yet this research is still in its infancy. The experimental techniques are difficult and the demands on theory rigorous. One of the main products of heavy ion research has been the thrust to re-examine the assumptions of reaction theory and now include many effects neglected for light ion analysis. This research has spurred the addition of multistep processes to simple direct processes and coupled channel calculations. (J.R.)

  2. Studies of heavy-ion reactions and transuranic nuclei

    International Nuclear Information System (INIS)

    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 32 S + 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 197 Au+ 208 Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction 209 Bi+ 136 Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral 209 Bi+ 136 Xe Collisions at E 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 μ - with a Muon Telescope

  3. [Studies of heavy-ion induced reactions]: Annual progress report

    International Nuclear Information System (INIS)

    Mignerey, A.C.

    1986-10-01

    An experiment was performed at the Lawrence Berkeley Laboratory Bevalac, extending previous studies using inverse reactions to 50 MeV/u 139 La incident on targets of C and Al. Studies of excitation energy division in lower energy division in lower energy heavy-ion reactions were furthered using kinematic coincidences to measure the excitation energies of primary products in the Fe + Ho reaction at 12 MeV/u. These results will provide important systematics for comparisons with previous measurements at 9 MeV/u on the same system and at 15 MeV/u on the Fe + Fe and Fe + U systems. Also studied were different aspects of 15 MeV/u Fe-induced reactions, with experiments performed at the Oak Ridge HHIRF. The first three contributions of this report constitute a major portion of the results from this research. Finally, at the Lawrence Berkeley Laboratory Bevalac a large detector array for coincident detection of fragmentation products in heavy-ion collisions below 100 MeV/u is being built. A list of publications, personnel, and activities is provided

  4. Polarization phenomena in heavy-ion reactions

    International Nuclear Information System (INIS)

    Sugimoto, K.; Ishihara, M.; Takahashi, N.

    1984-01-01

    This chapter presents a few key experiments which provide direct evidence of the polarization phenomena in heavy-ion reactions. The theory of polarization observables and measurements is given with the necessary formulae. The polarization phenomena is described and studies of product nuclear polarization in heavy-ion reactions are discussed. Studies of heavy-ion reactions induced by polarized beams are examined

  5. Studies of heavy-ion reactions and transuranic nuclei

    International Nuclear Information System (INIS)

    Schroeder, W.U.; Huizenga, J.R.

    1991-08-01

    The development of the ''cold-fusion'' episode is reviewed. Ongoing studies of compound-nucleus formation and decay via the neutron multiplicity distribution confirm the validity of conventional statistical theory. The excitation energy partition in near-barrier damped 58 Ni + 208 Pb collisions is found to be largely independent of the direction of net mass transfer, supporting a diffusion-like nucleon-exchange mechanism. Exclusive experiments on the heavy reaction systems 197 Au + 208 Pb and 209 Bi + 136 Xe in the Fermi-energy domain have revealed important new insights into the reaction mechanism, which is found to be dominated by damped, binary processes. The effectiveness of the neutron multiplicity as an impact-parameter filter is demonstrated. It is shown that very-heavy-ion reactions lead to transient nuclear systems with temperatures in excess of τ = 6 MeV and transfer of large, aligned spins to reaction fragments. The first measurements of neutrons in coincidence with kinematically identified reaction fragments provide evidence for the binary, sequential character of dissipative collisions in the Fermi-energy domain. Also for the first time, a full event characterization was achieved for nuclear reactions in terms of neutrons and charged particles. Technical information on this experiment is provided. First results yield strong evidence for dominantly binary primary reaction dynamics of even highly dissipative 209 Bi + (28MeV/u) 136 Xe collisions, associated with several intermediate-mass fragments

  6. Studies of complex fragment emission in heavy ion reactions

    International Nuclear Information System (INIS)

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

    1993-01-01

    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

  7. Study of energy deposition in heavy-ion reactions

    International Nuclear Information System (INIS)

    Mota, V. De La; Abgrall, P.; Sebille, F.; Haddad, F.

    1993-01-01

    An investigation of energy deposition mechanisms in heavy-ion reactions at intermediate energies is presented. Theoretical simulations are performed in the framework of the semi-classical Landau-Vlasov model. They emphasize the influence of the initial non-equilibrium conditions, and the connection with the incident energy is discussed. Characteristic times involved in the energy thermalization process and finite size effects are analyzed. (authors) 20 refs., 4 figs

  8. [Reaction mechanism studies of heavy ion induced nuclear reactions]: Annual progress report, October 1987

    International Nuclear Information System (INIS)

    Mignerey, A.C.

    1987-10-01

    The experiments which this group has been working on seek to define the reaction mechanisms responsible for complex fragment emission in heavy ion reactions. The reactions studied are La + La, La + Al, and La + Cu at 46.8 MeV/u; and Ne + Ag and Ne + Au reactions at 250 MeV/u. Another experimental program at the Oak Ridge Hollifield Heavy Ion Research Facility (HHIRF) is designed to measure the excitation energy division between reaction products in asymmetric deep inelastic reactions. A brief description is given of progress to date, the scientific goals of this experiment and the plastic phoswich detectors developed for this experiment

  9. Studies of complex fragment emission in heavy ion reactions

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  10. Study of elastic scattering between heavy ions. Reaction channel influence

    International Nuclear Information System (INIS)

    Doubre, Hubert.

    1978-01-01

    The role of absorption on the behavior of heavy ion angular distributions and excitaton functions has been investigated on light and medium mass systems. Comparison between 20 Ne+ 12 C and 16 O+ 16 O systems which lead to the same compound nucleus, shows that it originates from the direct channels strongly coupled to the entrance channel. Structures in the excitation functions occur for almost all the light systems and it is shown that the damping observed for heavier systems such as 40 Ca+ 40 Ca, essentially results on the predominance of Coulomb effects which hide the nuclear structure effects. Thus no valuable information on the details of S-matrix can be extracted for such an heavy system. A coherent description of the elastic scattering, based on a splitting of the scattering amplitude into two components, the modulus of each component varying smoothly as a function of energy and angle. The interference between these sub-amplitudes give rise to interference effects in angular distributions and excitation functions. The study of the main reaction channels of the 40 Ca+ 40 Ca system - i.e. deep inelastic reactions and fusion - also shows that the closed-shell nature of the interacting nuclei does not play any role in these processes due to the excitation processes in the first stage of the reactions which destroy the specific structure of the nuclei [fr

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

    International Nuclear Information System (INIS)

    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

  12. 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.

  13. 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.

  14. Studies of Heavy-Ion Reactions and Transuranic Nuclei

    International Nuclear Information System (INIS)

    Schroeder, W. Udo

    2016-01-01

    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.

  15. Relativistic heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Brink, D M

    1989-08-01

    The theory of quantum chromodynamics predicts that if nuclear matter is heated to a sufficiently high temperature then quarks might become deconfined and a quark-gluon plasma could be produced. One of the aims of relativistic heavy ion experiments is to search for this new state of matter. These lectures survey some of the new experimental results and give an introduction to the theories used to interpret them. 48 refs., 4 tabs., 11 figs.

  16. Relativistic heavy ion reactions

    International Nuclear Information System (INIS)

    Brink, D.M.

    1989-08-01

    The theory of quantum chromodynamics predicts that if nuclear matter is heated to a sufficiently high temperature then quarks might become deconfined and a quark-gluon plasma could be produced. One of the aims of relativistic heavy ion experiments is to search for this new state of matter. These lectures survey some of the new experimental results and give an introduction to the theories used to interpret them. 48 refs., 4 tabs., 11 figs

  17. Heavy ion transfer reactions

    Indian Academy of Sciences (India)

    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, in particular on the ...

  18. Application of radioanalytical techniques in the study of the products of heavy-ion reactions

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1989-01-01

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

  19. Studies of complex fragment emission in heavy ion reactions

    International Nuclear Information System (INIS)

    Sobotka, L.G.

    1989-01-01

    The production of large fragments, fragments with mass between light particles and fission fragments, in intermediate and high energy nuclear reactions has fostered the proposal of a number of novel reaction mechanisms. These include liquid-vapor equilibrium and nuclear shattering. Temporarily left in the wake of these exciting proposed mechanisms was the old standard, statistical decay of compound nuclei. To be sure, the standard treatment of compound nucleus decay did not deal with large fragment production. However, this omission was not due to any fundamental deficiency of statistical models, but rather an uncertainty concerning exactly how to splice large fragment emission into statistical models. A large portion of our program deals with this problem. Specifically, by studying the yields of large fragments produced in sufficiently low energy reactions we are attempting to deduce the asymmetry and l-wave dependence of large fragment emission from compound nuclear intermediates. This, however, is only half of the problem. Since the novel mechanisms proposed for large fragment emission were spawned by intermediate and high energy reaction data, we must also realize the relevance of the compound nucleus mechanisms at high energies. It is not unreasonable to suspect that compound nucleus-like objects are formed with less than complete momentum transfer and perhaps less than complete mass transfer. Therefore the study of energy, mass, and angular momentum transfer in incomplete fusion and non-compound reactions. This thread joins the apparently divergent subjects covered in this report

  20. Validating PHITS for heavy ion fragmentation reactions

    International Nuclear Information System (INIS)

    Ronningen, Reginald M.

    2015-01-01

    The performance of the Monte Carlo code system PHITS is validated for heavy-ion transport capabilities by performing simulations and comparing results against experimental data from heavy-ion reactions of benchmark quality. These data are from measurements of isotope yields produced in the fragmentation of a 140 MeV/u "4"8Ca beam on a beryllium target and on a tantalum target. The results of this study show that PHITS performs reliably. (authors)

  1. Targets for high-resolution studies with heavy-ion reactions

    International Nuclear Information System (INIS)

    Erskine, J.R.

    1975-01-01

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

  2. Spectroscopic studies with the use of deep-inelastic heavy-ion reactions

    International Nuclear Information System (INIS)

    Broda, R

    2006-01-01

    Gamma spectroscopic studies exploiting deep-inelastic heavy-ion reactions in thick target experiments are reviewed. The description of physical motivation, history of early experiments, analysis of the N/Z equilibration process as well as the outline of the experimental method and data analysis are followed by the presentation of main results obtained in various regions of the nuclide chart. Brief comments on thin target spectroscopy experiments involving fragment detection and future outlook are summarized. (topical review)

  3. 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.

  4. Heavy ion reactions at low energies

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1985-01-01

    Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

  5. Multiparticle production in heavy-ion reactions

    International Nuclear Information System (INIS)

    Pelte, D.

    1980-01-01

    This lecture is concerned with the question how many particles and what kind of them are produced in heavy-ion collisions at energies about 10 MeV/n. We tend to assume that heavy-ion reactions at this energy are binary reactions. The experimental set consisting of two large ionization chambers serving to detection, in coincidence, the reaction fragments is described. With this set-up a number of reactions induced on 27 Al, 28 Si and 40 Ca by the 32 S beam of 135 and 190 MeV energy has been studied. Two-fragments inclusive and exclusive reactions were investigated. The assumption of a sequential statistical decay gives the best agreement with the data for all analyzed cases. (H.M.)

  6. Study of peripheral heavy ion reactions at 84 MeV/nucleon

    International Nuclear Information System (INIS)

    Rabe, H.J.

    1986-01-01

    In peripheral heavy ion reactions between 18 O and 58,64 Ni, 18 O and u97 Au, as well as between 12 C and 197 Au at an incident energy of 84 MeV/nucleon azimutal angular correlations between projectile fragments and light particles (p,d,t,α) were studied. By the selection of heavy projectile fragments Z p ≥6 and small multiplicity of the light particles from the target or from the reaction zone peripheral reactions between the heavy ions were selected. The data analysis showed that the emission of light particles under ΔΦ=180 0 , i.e. on the side lying relative to the beam axis opposite to the projectile fragment, is distinctly increased. The counting-rate ratio N(ΔΦ=180 0 )/N(ΔΦ=0 0 ) can amount up to 3.5:1. A detailed analysis yields the result that the anisotropy is closely correlated to the transverse momentum p t of the projectile fragments, whereby the connection for p t 600 MeV/c is nearly linear. The absolute cross section for these processes with small multiplicity of the light particles in coincidence with heavy projectile fragments (Z p ≥6) lies in the order of magnitude of 200 mb. (orig./HSI) [de

  7. Electron capture rates in stars studied with heavy ion charge exchange reactions

    Science.gov (United States)

    Bertulani, C. A.

    2018-01-01

    Indirect methods using nucleus-nucleus reactions at high energies (here, high energies mean ~ 50 MeV/nucleon and higher) are now routinely used to extract information of interest for nuclear astrophysics. This is of extreme relevance as many of the nuclei involved in stellar evolution are short-lived. Therefore, indirect methods became the focus of recent studies carried out in major nuclear physics facilities. Among such methods, heavy ion charge exchange is thought to be a useful tool to infer Gamow-Teller matrix elements needed to describe electron capture rates in stars and also double beta-decay experiments. In this short review, I provide a theoretical guidance based on a simple reaction model for charge exchange reactions.

  8. Studies of heavy ion reactions and transuranic nuclei. Progress report, August 1, 1979-July 31, 1980

    International Nuclear Information System (INIS)

    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 209 Bi + 136 Xe reaction; the fragment yields for specific Z and A for projectile-like fragments produced in the reaction of 8.3-MeV/u 56 Fe ions with targets of 56 Fe, 165 Ho, 209 Bi, and 238 U; and time distributions of fragments from delayed fission after muon capture for muonic 235 U, 238 U, 237 Np, 239 Pu, and 242 Pu

  9. Heavy ion reactions at high energies

    International Nuclear Information System (INIS)

    Jakobsson, Bo.

    1977-01-01

    A review on heavy ion experiments at energies >0.1GeV/nucleon is presented. Reaction cross-sections, isotope production cross-sections and pion production in nucleus-nucleus collisions are discussed. Some recent models for heavy ion reactions like the abrasion-ablation model, the fireball model and the different shock-wave models are also presented

  10. Scattering and transfer reactions with heavy ions

    International Nuclear Information System (INIS)

    Hussein, M.S.

    From the elastic scattering analysis the input parameters are found for the inelastic scattering analysis and the transfer reactions of the heavy ion reactions. The main theme reported is the likeness and conection among these processes. (L.C.) [pt

  11. Study of pheripheral heavy ion reactions at 84 MeV/nucleon

    International Nuclear Information System (INIS)

    Rabe, H.J.

    1986-04-01

    In peripheral heavy ion collisions between 18 O and sup(58,64)Ni, 18 O and 197 Au, as well as between 12 C and 197 Au at an incident energy of 84 MeV/nucleon azimutal angular correlations between projectile fragments and light particles (p,d,t,α) were studied. For the detection of the projectile fragments a 54-fold segmented in theta and phi space-resolving and Z-insensitive scintillator hodoscope was developed and constructed. The particle identification is aimed in the angular range 2 0 0 only by a ΔE measurement because the fragments exhibit a narrow velocity distribution around the beam velocity. The theta and phi resolution is 1.5 0 and 60 0 . In the external angular range 6.5 0 0 the particle identification is performed by simultaneous measurement of ΔE abd Esub(rest) in phoswich detectors with a theta and phi resolution of 4.5 0 respectively 30 0 . The light particles were detected in a large-area space-resolving scintillator hodoscope. Because this hodoscope possesses no particle identification and thus does not allow energy measurement, the coincidence measurement was supplemented by the detection of the light particles in semiconductor telescopes with good energy and particle resolution. By the selection of heavy projectile fragments Zsub(p)>=6 and low multiplicity of the light particle from the target or from the reaction zone peripheral reactions between the heavy ions were selected. (orig./HSI) [de

  12. Study of a new mechanism of reaction between heavy ions: the quasi-fission

    International Nuclear Information System (INIS)

    Ngo, Christian.

    1975-01-01

    A new type of deep inelastic reaction between two heavy ions (quasi-fission) has been discovered and studied when the product Z 1 Z 2 between the two ion atomic numbers is greater than or approximately equal to 1500. This mechanism is mainly binary, the total kinetic energy of the products is the one expected for a binary fission giving the same products, most of the products have masses very close to the initial masses, the angular distribution of the light products is peaked slightly forwards the projectile grazing angle (when the bombarding energy is not too much above the interaction barrier), at last, the total cross section for this process is a large part of the total reaction cross section. These results have been interpreted on the one hand using a static model and on the other hand using a dynamic model. An interaction potential between the two heavy ions has been derived using the energy density formalism within the framework of the sudden approximation. It has been shown that the nuclear part satisfies a scaling law which allows to factorize it in one term which depends on the two ion masses and another term which is independent of the system (universal function). Using the critical distance notion, the static calculations reproduce the quasi-fission cross sections. With regards to the dynamical calculations, the previously described potential has been introduced within the framework of Deubler and Dietrich's model. It is a classical dynamical calculation including dissipative terms. The vibration degrees of freedom of each ion have been explicitely taken into account. This calculation nicely reproduces both the energy loss in the relative motion, the focusing effect of the angular distribution, and the quasi-fission cross sections [fr

  13. Study of heavy ion fusion reaction of 58Ni + 24Mg at 11 MeV/nucleon

    International Nuclear Information System (INIS)

    Shea, J.Y.

    1991-01-01

    This thesis presents a study of the heavy ion fusion reaction in which a 58 Ni projectile bombards a 24 Mg target at 11 MeV/nucleon. The incident projectile energy was purposefully chosen so as the system studied to be at the onset of the more complex and interesting phenomenon of incomplete fusion. The physics motivation is to probe the central collision of a heavy, energetic, and asymmetric system by means of both inclusive and exclusive experimental measurements. The experiment was performed at HHIRF (Holifield Heavy Ion Research Facility) by using the coupled accelerators at Oak Ridge National Laboratory. The reaction products were measured by the new open-quotes HILI-Ringclose quotes large solid angle detector system at Oak Ridge National Laboratory. The thesis discusses the physics motivation and the systematics of heavy ion fusion reactions. Details of the design and construction of a new CsI(T1) Ring detector is given. Since this is the first such study performed on the Heavy Ion Light Ion (HILI) detector, an extensive discussion of the calibration procedures and the data reduction methods are given. The fusion reaction data were analyzed in both inclusive and exclusive modes with the result that a valuable new perspective on the deconvolution of the reaction mechanism has been achieved

  14. Giant resonances in heavy-ion reactions

    International Nuclear Information System (INIS)

    Hussein, M.S.

    1982-11-01

    The several roles of multipole giant resonances in heavy-ion reactions are discussed. In particular, the modifications in the effective ion-ion potencial due to the virtual excitation of giant resonances at low energies, are considered and estimated for several systems. Real excitation of giant resonances in heavy-ion reactions at intermediate energies are then discussed and their importance in the approach phase of deeply inelastic processes in emphasized. Several demonstrative examples are given. (Author) [pt

  15. The use of statistical models in heavy-ion reactions studies

    International Nuclear Information System (INIS)

    Stokstad, R.G.

    1984-01-01

    This chapter reviews the use of statistical models to describe nuclear level densities and the decay of equilibrated nuclei. The statistical models of nuclear structure and nuclear reactions presented here have wide application in the analysis of heavy-ion reaction data. Applications are illustrated with examples of gamma-ray decay, the emission of light particles and heavier clusters of nucleons, and fission. In addition to the compound nucleus, the treatment of equilibrated fragments formed in binary reactions is discussed. The statistical model is shown to be an important tool for the identification of products from nonequilibrium decay

  16. Heavy ion and hadron reactions in emulsion

    International Nuclear Information System (INIS)

    Otterlund, I.

    1979-04-01

    Recent results from heavy ion and hadron reactions in emulsion are reviewed. General properties of hadron-reaction multiplicities and their correlation to the production of recoiling protons are given. Properties of pseudo-rapidity distributions of shower-particles especially the particle production in the central region of pseudo-rapidity will be discussed. Non-peripheral heavy ion reactions are compared to recent participant-spectator model calculations. Very energetic cosmic ray events will be examined in the light of recent results from hadron-nucleus reactions. (author)

  17. On experimental and theoretical studies of dynamics and particle production in p-nucleus and heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Fokin, A.B

    1998-11-01

    Several experiments and theoretical models of intermediate energy heavy ion collision physics are presented in this thesis. Statistical and dynamical aspects of nuclear collisions are widely discussed these days, particularly in connection with the multifragmentation phenomenon and the possible link to a liquid-gas phase transition in the spinodal region of nuclear matter phase diagram. Experimental techniques which allow us to measure various parameters of hot and dense (equilibrated) regions (emission sources) formed in a heavy ion collision are well established nowadays. In recent CHIC (Celsius Heavy Ion Collaboration) experiments the properties of such sources were measured using slowly ramping mode of the CELSIUS storage ring. In this thesis the entropy and chaos production in nuclear collisions is discussed in connection with the t/d/p ratios. Subthreshold pion production explores collective effects in heavy ion collisions and brings additional information about the equation of state of nuclear matter. Continuous pion production excitation functions were measured in the beam energy region from far below the nucleon-nucleon threshold up to the delta dominant region. Mass and angular dependencies of pion production are discussed. A version of the molecular dynamics model which includes pion production in direct nucleon-nucleon collisions was developed and experimental data were analysed in the scope of this model. Properties of the emission sources formed in heavy ion collisions at energies below 50A MeV were studied in the experiments of fragmentation type performed by CHIC. Temperatures of these sources were extracted from fragment energy spectra and from `isotopic effect`. A version of the quantum molecular dynamics model, where the Pauli potential is introduced into the Hamiltonian, was combined with the statistical multifragmentation model and used to explore dynamical and statistical properties of the reaction development. The artificial neural networks

  18. On experimental and theoretical studies of dynamics and particle production in p-nucleus and heavy ion reactions

    International Nuclear Information System (INIS)

    Fokin, A.B.

    1998-11-01

    Several experiments and theoretical models of intermediate energy heavy ion collision physics are presented in this thesis. Statistical and dynamical aspects of nuclear collisions are widely discussed these days, particularly in connection with the multifragmentation phenomenon and the possible link to a liquid-gas phase transition in the spinodal region of nuclear matter phase diagram. Experimental techniques which allow us to measure various parameters of hot and dense (equilibrated) regions (emission sources) formed in a heavy ion collision are well established nowadays. In recent CHIC (Celsius Heavy Ion Collaboration) experiments the properties of such sources were measured using slowly ramping mode of the CELSIUS storage ring. In this thesis the entropy and chaos production in nuclear collisions is discussed in connection with the t/d/p ratios. Subthreshold pion production explores collective effects in heavy ion collisions and brings additional information about the equation of state of nuclear matter. Continuous pion production excitation functions were measured in the beam energy region from far below the nucleon-nucleon threshold up to the delta dominant region. Mass and angular dependencies of pion production are discussed. A version of the molecular dynamics model which includes pion production in direct nucleon-nucleon collisions was developed and experimental data were analysed in the scope of this model. Properties of the emission sources formed in heavy ion collisions at energies below 50A MeV were studied in the experiments of fragmentation type performed by CHIC. Temperatures of these sources were extracted from fragment energy spectra and from 'isotopic effect'. A version of the quantum molecular dynamics model, where the Pauli potential is introduced into the Hamiltonian, was combined with the statistical multifragmentation model and used to explore dynamical and statistical properties of the reaction development. The artificial neural networks

  19. Studies of the nuclear inertia in fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Moeller, P.; Nix, J.R.

    1978-01-01

    On the basis of the non-self-consistent cranking model the authors study some aspects of the nuclear inertia of interest in fission and heavy-ion reactions. First, the authors consider in the adiabatic limit the inertia for a doubly closed-shell nucleus in a deformed spheroidal harmonic-oscillator single-particle potential plus a small perturbation. When expressed in terms of a coordinate that describes the deformation of the nuclear matter distribution, the inertia for small oscillations about a spherical shape is exactly equal to the incompressible, irrotational value. For large distortions it deviates from the incompressible, irrotational value by up to about +-1% away from level crossings. Second, in order to study the dependence of the inertia upon a level crossing, two levels of the above system are considered. This is done both in the adiabatic limit and for large collective velocities. At level crossings the adiabatic inertia relative to the deformation of the matter distribution diverges as 1/modΔV, where modΔV is the magnitude of the perturbation. However, for large collective velocities the contribution to the inertia from a level crossing is less than 4modΔV(d(rsub(m))/dt) 2 where d(rsub(m))/dt is the collective velocity of the matter distribution. Although the effect of large velocities on the remaining levels of the many-body system or the effect of a statistical ensemble of states has not been considered, some of the results suggest that for high excitation energies and moderately large collective velocities the nuclear inertia approaches approximately the irrotational value. (Auth.)

  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. Review of heavy ion reaction mechanisms

    International Nuclear Information System (INIS)

    Ngo, C.

    1986-04-01

    We review some of the many aspects of heavy-ion reaction mechanisms observed at bombarding energies smaller than approximately 50 MeV/u that is to say in what is called the low bombarding energy domain and the intermediate bombarding energy domain. We emphasize the results concerning the use of very heavy projectiles which has led to the observation of new mechanisms

  2. Contribution to the source size study produced in the heavy ion reactions at 30MeV/u

    International Nuclear Information System (INIS)

    Khelfaoui, Ben Abed.

    1991-05-01

    In this work are given the measurement results of source sizes produced in the heavy ion reactions at intermediate energies, and are studied the correlations of light particles (proton-proton correlations) with very weak momentum. The used technics is an application of intensity interferometry to the case of particles submitted to hadronic interactions. The studied reactions were induced by a 20 We beam on 12 C, 59 Co, and 197 Au targets at 25 0 C and on 27 Al (at 22 0 C, 60 0 C and 80 0 C). Beam energy was 30 MeV/u [fr

  3. Systematic study of sub-barrier fusion enhancement in heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, C E; Aleixo, A N; Barbosa, V C; Canto, L F; Donangelo, R [Universidade Federal Rural do Rio de Janeiro (Brazil). Dept. de Fisica

    1989-08-14

    A systematic study of the heavy-ion fusion-cross-section enhancement at sub-barrier energies is carried out. The asymptotic energy shift introduced in a previous paper as a measure of this enhancement is considered from a theoretical point of view. It is claimed that this energy shift is composed of two terms: One of them is related to the bulk properties of nuclear matter, and the other corresponds to deviations depending on the specific nuclear structure of the collision partners. We show that the former can be approximately described by the neck-formation model for fusion and the latter is frequently a consequence of static deformation or vibrational excitation of the projectile and/or the target. A comparison of the neck-formation effects with those arising from neutron flow suggests that there is a connection between these two mechanisms. (orig.).

  4. 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.

  5. 7th high energy heavy ion study

    International Nuclear Information System (INIS)

    Bock, R.; Gutbrod, H.H.; Stock, R.

    1985-03-01

    These proceedings contain the articles presented at the named conference. They deal with relativistic heavy ion reactions, the expansion and freeze-out of nuclear matter, anomalon experiments, and multifragmentation and particle correlations in heavy ion reactions. See hints under the relevant topics. (HSI)

  6. Direct processes in heavy ion reactions

    International Nuclear Information System (INIS)

    Bunakov, V.E.; Zagrebaev, V.I.

    1983-01-01

    Direct processes in heavy ion reactions are investigated. Relative theoretical contributions in the inclusive spectrum of α particles on processes of stripping breakup and inelastic breakup are estimated using the 22 Ne+ 181 Ta reaction as an example. The consideration is performed taking into account Coulomb and nuclear distortions in the inlet and outlet ion channels. It is shown that the hard edge of α spectrum and its maximum are well described by peripheral direct processes. The hard spectrum edge is conditioned by the pure process of ''incomplete fussion'' bringing about the production af a compound nucleus. The main part of inclusive spectrum is conditioned by reactions of inelastic and elastic breakup not connected with the production of a compound nucleus

  7. Studies of complex fragment emission in heavy ion reactions. Progress report, January 1, 1993 - September 1, 1995

    International Nuclear Information System (INIS)

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

    1995-01-01

    This work involves the study of low and intermediate energy heavy-ion nuclear reactions. This work has two foci. First, the authors desired to learn about the properties of both nuclei and nuclear matter under abnormal conditions. Their efforts towards this end run abreast of those for their second focus which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because their experimental laboratory for studying nuclear properties is a dynamic one. Their task is to answer the questions of how nuclear and nuclear matter properties are reflected in the dynamics of the reactions. The second objective also has great intrinsic value in that they can anticipate improving upon their understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has been: to study the dynamics of fusion reactions, specifically the dynamics of energy, mass, and angular momentum deposition. This work includes reactions near the Coulomb barrier, where fusion dominates the reaction cross section as well as higher energies where incomplete fusion reactions are the primary reactions. This includes the dynamics of fission, still the premier example of collective nuclear motion, as a function of excitation, spin, mass, and mass asymmetry. The authors push these kinds of studies into the intermediate energy domain, and where novel reaction scenarios are predicted. They have studied very central and peripheral collisions between very massive nuclei, and simplified projectile fragmentation reactions utilizing medium to light mass projectiles. The study of central collisions has shown us the importance of collective expansion. The study of peripheral collisions between very heavy nuclei has demonstrated the importance of dynamical production of fragments from the neck region

  8. Spin transfer in reactions between heavy ions

    International Nuclear Information System (INIS)

    Dong Pil Min.

    1980-06-01

    The model presented affords a better understanding of the manner in which the orbital angular moment can be converted into an intrinsic spin in the collision between two heavy ions. After referring to the vector fields and the collective energy of a spheroidal nucleus, the calculation of the exchange of nucleons is described and the dissipation function is constructed. The spin transfer and the reorientation of the spin during the reaction are then examined (effect of friction and vibration). The estimated calculations are compared with the results of the 63 Cu+ 197 Au and 86 Kr+ 209 Bi experiments. The sensitivity of the calculation to the parameters of the model is discussed (nuclear potential, vibrational inertial parameter) [fr

  9. Studies of heavy-ion reactions and transuranic nuclei: Progress report, September 1, 1987--August 31, 1988

    International Nuclear Information System (INIS)

    Schroeder, W.U.; Huizenga, J.R.

    1988-08-01

    The effect of successively increasing gradients of the potential energy surface on mass and charge transport was studied experimentally and theoretically with a series of damped reactions induced by 48 Ca, 64 Ni, 58 Ni, and 40 Ca projectiles on 238 U targets. Combined transport-evaporation calculations that were performed for the interpretation of data demonstrate a systematic deficiency of quantitative reaction theory. A new type of experimental method has been employed to study several moments of the energy partition in damped reactions, measuring multiplicity correlations of neutrons emitted from the asymptotic fragments with a specially designed, directionally sensitive multiplicity counter. First results indicate significant departures of damped reaction systems from thermal equilibrium. Employing realistic Monte Carlo simulation of published experiments, it was demonstrated that the directions of net mass transfer and energy deposit are uncorrelated in damped reactions. Evaporative and preequilibrium neutron emission has been studied for the asymmetric heavy-ion system 139 La + 40 Ar. The disequilibrium energy transport phenomena observed in the experiment are quantitatively reproduced by model calculations. A strong impact-parameter dependence of preequilibrium emission is demonstrated. The emission patterns of α particles evaporated from high spin compound nuclei, previously attributed to exotic nuclear shapes, have been explained in realistic statistical model calculations for nuclei with conventional shapes. A new octal digital delay module has been designed and tested

  10. Complementarity between neutron capture and heavy-ion reactions in nuclear structure studies

    International Nuclear Information System (INIS)

    Schult, O.W.B.

    1978-01-01

    The study of the complementarity of certain nuclear reactions in nuclear structure studies includes spectroscopic methods, nuclear rotation and coupling of nucleons to the core, and the de-excitation and structure of high lying states. 23 references

  11. 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.

  12. Nuclear transfer in peripheral heavy ion reactions

    International Nuclear Information System (INIS)

    Werner, K.

    1984-01-01

    The aim of the whole thesis is to understand the experimental results of N. Frascaria et al. (1980), namely structures in the cross section as function of the excitation energy for the reaction 40 Ca + 40 Ca at 400 MeV incident energy. We present therefore in chapter 1 a simple model of two identical potentials with only two energy levels. On the base of statistically independent T-L excitations and by fitting a two parameters to the experiments it succeeds to reproduce sufficiently the experimental results. The next step is a microscopical treatment of these parameters for the understanding and the foundation of the fitted values. For this we develop in chapter 2 a theory of collective variables in the framework of TDHF which allows to perform in chapter 3 in a very transparent way microscopical calculations and especially to understand the transfer behaviour in peripheral heavy ion reactions. This transfer behaviour will also be the key for the understanding of the experimental structures. (orig.) [de

  13. Pre-equilibrium decay processes in energetic heavy ion reactions

    International Nuclear Information System (INIS)

    Blann, M.

    1986-01-01

    The Boltzmann master equation (BME) is defined for application to precompound decay in heavy ion reactions in the 10 100 MeV/nucleon regime. Predicted neutron spectra are compared with measured results for central collisions of 20 Ne and 12 C with 165 Ho target nuclei. Comparisons are made with subthreshold π 0 yields in heavy ion reactions between 35 and 84 MeV/nucleon, and with the π 0 spectra. The BME is found to be an excellent tool for investigating these experimentally observed aspects of non-equilibrium heavy ion reactions. 18 refs., 8 figs

  14. Nuclear dynamics in heavy ion induced fusion-fission reactions

    International Nuclear Information System (INIS)

    Kapoor, S.S.

    1992-01-01

    Heavy ion induced fission and fission-like reactions evolve through a complex nuclear dynamics encountered in the medium energy nucleus-nucleus collisions. In the recent years, measurements of the fragment-neutron and fragment-charged particle angular correlations in heavy ion induced fusion-fission reactions, have provided new information on the dynamical times of nuclear deformations of the initial dinuclear complex to the fission saddle point and the scission point. From the studies of fragment angular distributions in heavy ion induced fission it has been possible to infer the relaxation times of the dinuclear complex in the K-degree of freedom and our recent measurements on the entrance channel dependence of fragment anisotropies have provided an experimental signature of the presence of fissions before K-equilibration. This paper reviews recent experimental and theoretical status of the above studies with particular regard to the questions relating to dynamical times, nuclear dissipation and the effect of nuclear dissipation on the K-distributions at the fission saddle in completely equilibrated compound nucleus. (author). 19 refs., 9 figs

  15. Contributions to the study of nuclear reactions mechanism induced by heavy ions on intermediate mass nuclei

    International Nuclear Information System (INIS)

    Avrigeanu, M.

    1982-01-01

    A detailed analysis is presented, based on Hauser-Feshbach statistical model calculations of the γ-ray excitation functions measured in the sup(74,76)Ge ( 12 C, xn) and sup(72,73)Ge ( 16 O,xnyp) reactions. The most usual quantities provided by the in beam γ-ray measurements such as the cross sections for the population of the final states as well as the decay scheme and the degree of alignment of these states mainly offer the means of testing models of both the reaction mechanism and nuclear properties of high excitation energies, since they concentrate information on the whole reaction process. Experimental information on sup(85,86)Sr and sup(85,86)Y, γ-decay scheme and the excitation functions for the population of the final states were obtained by sub(74,76)Ge ( 12 C,αn), n = 2-4, sup(74,76)Ge ( 14 N,xn) n = 3-5, sup(72,73)Ge ( 16 O,xnyp), x = 1-3, y=1 reactions at incident energies between 35 and 60 MW. Statistical model calculations in the Hauser-Feshbach formalism have been compared with the experimental γ-ray excitation functions. The competitive emission of neutrons, protons, alpha particles and gamma rays from the compound nucleus has been considered in the calculations. The calculations describe satisfactorily the total cross sections for the population of the 2n, 3n and 4n channels for 12 C + sup(74,76)Ge and 2n, np, 3n and 2np channels for 16 O + 72 Ge. The calculations are sensitive to the characteristics of the excited levels (such as spin values) but htis this sensitivity could be exploited with some reliability only if one makes use of a rather complete level scheme in the calculations. In the case of 2n, np, 3n and 2 np channels for 16 O+ 73 Ge one concludes on the reliability of consideration some structural aspects in the calculations

  16. Dynamical processes in heavy ion reactions

    International Nuclear Information System (INIS)

    Blann, M.; Remington, B.A.

    1988-01-01

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

  17. Heavy ion reactions in the transition region

    International Nuclear Information System (INIS)

    Hendrie, D.L.

    1977-11-01

    Evidence is given for a serious and systematic failure of the DWBA to predict the cross sections for single nucleon transfers induced by heavy ions above about 10 MeV/Nucleon beam energies. This is perhaps related to a coherent coupling to an increasing cross section to the quasi-elastic continuum, which also shows an anomalous energy dependence at about the same energy

  18. Study on fusion potential barrier in heavy ion reactions based on the dynamical model

    International Nuclear Information System (INIS)

    Tian Junlong; Wu Xizhen; Li Zhuxia; Wang Ning; Liu Fuhu

    2004-01-01

    Based on an improved quantum molecular dynamics model the static and dynamic potential in the entrance channel of synthesis of superheavy nuclei are studied. The dependence of the static potential (and driving potential) on mass-asymmetry is obtained. From this study authors find out that the mass-symmetric system seems to be difficult to fuse and the fusing system with the largest driving potential could be the optimal choice of the projectile-target combination. By comparing the static potential barrier with the dynamic one authors find that the latter one is lower than former one obviously, and that the dynamical potential barrier is entrance energy dependent. The maximum and minimum of dynamic potential barriers approach to the diabatic (sudden approximation) and the adiabatic static potential barriers, respectively

  19. Heavy-Ion Reactions: a current awareness bulletin

    International Nuclear Information System (INIS)

    Kinser, W.H.

    1985-01-01

    This current awareness bulletin announces on a semimonthly basis the current worldwide information entered into the Energy Data Base on theoretical and experimental studies (including instrumentation) of heavy-ion (A > 4) nuclear reactions for nuclear structure studies; for producing new isotopes and superheavy elements for nuclear, atomic, and chemical properties studies; for understanding quantum chromodynamics as an exact theory of the strong nuclear force; and for studying the equations of state and phases of nuclear matter (pion condensate and quark matter) of special interest in astrophysics, and cosmology. An abstract is included with each citation. Regular publication began in January 1985

  20. Current experimental situation in heavy-ion reactions

    International Nuclear Information System (INIS)

    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

  1. Potential surfaces in symmetric heavy-ion reactions

    International Nuclear Information System (INIS)

    Royer, G.; Piller, C.; Mignen, J.; Raffray, Y.

    1989-01-01

    The entrance channel in symmetric heavy-ion reactions is studied in the liquid-drop model approach including the nuclear proximity energy and allowing ellipsoidal deformations of the colliding nuclei. In the whole mass range a sudden transition occurs from oblate to prolate shapes when the proximity forces become important. This strongly affects the effective moment of inertia. The ellipsoidal deformations reduce the fusion barrier width for light systems and lower the potential barrier height for medium and heavy nuclei. The results are in agreement with the empirical effective barrier shift determined by Aguiar et al for the 58 Ni + 58 Ni, 74 Ge + 74 Ge and 80 Se + 80 Se systems. The sub-barrier fusion enhancement in heavy-ion reactions might be explained by the slowness of the process. Below the static fusion barrier, the reaction time is long; allowing some adiabaticity and deformations of the colliding ions. Above the barrier, the reaction is more sudden and the deformation degree of freedom is frozen

  2. New aspects of high energy heavy-ion transfer reactions

    International Nuclear Information System (INIS)

    Scott, D.K.

    1975-03-01

    New aspects of heavy ion reactions at incident energies in the region of 10 MeV/nucleon are discussed with an emphasis on the peripheral nature of the collisions, which leads to simplicities in the differential cross sections. The distortion of the peripheral distribution through the interference of direct and multistep processes is used to illustrate aspects of high energy reactions unique to heavy ions. The simplicities of the distributions for reactions on lighter nuclei are exploited to give new information about nuclear structure from direct and compound reactions at high energy. (16 figures, 32 references) (U.S.)

  3. Studies in heavy ion activation analysis Pt. 4

    International Nuclear Information System (INIS)

    Lass, B.D.; Ojo, J.F.; Schweikert, E.A.

    1980-01-01

    The use of 7 MeV 6 Li + for heavy ion activation analysis was investigated. A survey of reactions, involving targets of lithium through oxygen inclusive, were studied for production of β + radioactivation products with half-lives of 10 1 -10 5 seconds. Specific activities for all reactions under the experimental conditions are reported and their use for analysis is assessed. (author)

  4. Reaction mechanisms for the synthesis of the heaviest elements from heavy ion reactions

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.

    1988-10-01

    This review paper concerns fusion reactions with light heavy-ions, cold fusion, transfer reactions using light heavy-ions or heavy ions. In two appendices, methods for the separation and detection of nuclides in the domain of heaviest elements are described and a comment on the discovery of the element 104 is given. 51 figs., 10 tabs., 335 refs

  5. Study of heavy ion collisions with TAPS

    NARCIS (Netherlands)

    Löhner, H.

    The photon spectrometer TAPS is a versatile instrument to measure nuclear bremsstrahlung and neutral mesons via their gamma decay. The formation and evolution of compressed nuclear matter is studied in heavy ion collisions at relativistic energies by analyzing the yield and spectral distribution of

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

    Indian Academy of Sciences (India)

    82, No. 5. — journal of. May 2014 physics pp. 879–891. Classical simulations of heavy-ion fusion reactions and weakly-bound projectile breakup reactions ... on the collision energy and the moment of inertia of the deformed nucleus. ... where each individual nucleus consists of a number of protons and neutrons, in some.

  7. Applications of heavy-ion reactions on hydrogen isotopes

    International Nuclear Information System (INIS)

    Evers, E.J.

    1987-01-01

    This thesis describes various aspects of 'inverse' reactions between the lightest nuclides, hydrogen and deuterium, and heavy ions in the range from carbon to phosphorus. The reactions studied in this thesis always result in one light ejectile and one excited heavy nucleus. Coincidence experiments have been performed in which both the emitted light particle and the gamma radiation emitted by the excited heavy nucleus produced, are detected. Ch. 1 describes the system built for the acquisition of data obtained in such coincidence experiments. Ch. 2 describes precision measurements of nuclear lifetimes and stopping powers. Coincident Doppler shift attenuation (DSA) experiments were performed with the reaction 2 H( 31 P,pγ) 32 P at E( 31 P 7+ )=50 MeV and thin Ti 2 H targets on Au, Ag and Cu backings. Mean lifetimes of the E x =513, 1150, 1323 and 1755 levels were determined with experimental stopping powers of Forster et al. These lifetimes were used as input in further analysis of the experimental data and of an additional experiment with a target on Mg backing to determine a consistent set of stopping power data for P ions with a velocity in the range 0-8(c/137) in the four materials mentioned. Ch.'s 3 and 4 deal with narrow resonances in reactions of nitrogen and fluorine beams with hydrogen targets. In Ch. 3 a method is described for the calibration of analyzing-magnet systems of heavy-ions accelerators. Ch. 4 describes an experiment to investigate the hydrogen concentration in silicon nitride films using a resonant inverse nuclear reaction. This method turns out to be a very suitable one for determining hydrogen concentration profiles with a good depth resolution over a large depth. 69 refs.; 23 figs.; 7 tabs

  8. Selectivity in heavy ion transfer reactions

    International Nuclear Information System (INIS)

    Boucenna, A.

    1989-01-01

    One-two-and three-nucleon stripping reactions induced by 480 MeV 12 C and by 793 MeV 16 O have been studied on 12 C, 16 O, 28 Si, 40 Ca, and 54 Fe targets. Discrete levels are fed with cross sections up to 1 mb/sr for d-transfer reactions and one and two orders of magnitude less for 2p- and 3 He-transfers, respectively. These reactions are governed by two selection rules contained in the semi-classical model of Brink: i) Large orbital final momentum states are selectively populated and ii) The most highly populated states correspond to no-flip transitions. Two-proton transfer reactions induced by 112 MeV 12 C on even Ni and Zn isotopes are found to be less selective than two-neutron transfer reactions induced by the same projectile on the same targets in a similar incident energy range. The additional collective aspects observed in the two-proton transfers are examined in view of a semiphenomenological model of two quasi-particles coupled to a triaxial asymmetric rotor. The energy of excited states is well reproduced by simple shell model calculations. Such estimates are useful in proposing spins of newly observed states, especially as the shapes of the measured angular distributions are independant of the final spin of the residual nucleus. The experimental results of two-proton and two-neutron stripping reactions and the simple shell model allow an estimate of two-body matrix elements describing the nucleon-nucleon interaction and of the Coulomb energy [fr

  9. Reaction mechanism in high energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Tanihata, Isao.

    1982-04-01

    The reaction mechanism in high energy heavy-ion collision is discussed. The discussion is mainly based on the experimental data. Empirical equations have been given for the total cross-sections of nucleus-nucleus reactions and the reaction cross-sections. These cross-sections are well described by the geometrical size of the colliding nuclei. The cross-sections are also understood by microscopic calculation. The charged particle multiplicity gives additional information about the geometrical aspect of heavy ion collision. The data suggested that the total energy, independent of projectile size, is most important for determining the multiplicity. The inclusive proton spectrum in a heavy ion collision showed two distinct regions. The one is the fragment region, and the other the participant region. The spectral shapes of inclusive pion spectra are reasonably well explained by the Coulomb interaction of pions with nuclear fragments. The high energy heavy ion reaction occurs in the overlap region of the projectile and target. This has been tested by measuring the number of participants for various reactions. The space and the time structure of the collision are also discussed in this paper as well as the dynamical aspects of the collision. (Kato, T.)

  10. Relativistic hydrodynamics, heavy ion reactions and antiproton annihilation

    International Nuclear Information System (INIS)

    Strottman, D.

    1985-01-01

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

  11. Probing the nuclear structure with heavy-ion reactions

    International Nuclear Information System (INIS)

    Broglia, R.A.

    1982-01-01

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

  12. Application of laplace transform method in heavy ion reaction research

    International Nuclear Information System (INIS)

    Wang Jinchuan; Xi Hongfei; Guo Zhongyan; Zhan Wenlong; Zhu Yongtai; Zhou Jianqun; Liu Guanhua

    1993-01-01

    Laplace transform method (LTM) is applied to investigate the effects of different spectroscopy amplifiers parameters on identification of the light charged particles (LCP) emitted from 12 C(46,7 MeV/u) + 58 Ni reaction. The significance of application of LTM in heavy ion experimental nuclear physics is also discussed

  13. Heavy ion studies with CMS HF calorimeter

    International Nuclear Information System (INIS)

    Damgov, I.; Genchev, V.; Kolosov, V.A.; Lokhtin, I.P.; Petrushanko, S.V.; Sarycheva, L.I.; Teplov, S.Yu.; Shmatov, S.V.; Zarubin, P.I.

    2001-01-01

    The capability of the very forward (HF) calorimeter of the CMS detector at LHC to be applied to specific studies with heavy ion beams is discussed. The simulated responses of the HF calorimeter to nucleus-nucleus collisions are used for the analysis of different problems: reconstruction of the total energy flow in the forward rapidity region, accuracy of determination of the impact parameter of collision, study of fluctuations of the hadronic-to-electromagnetic energy ratio, fast inelastic event selection

  14. Heavy Ion Fusion Systems Assessment study

    International Nuclear Information System (INIS)

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

    1986-07-01

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

  15. Prospect of heavy ion studies in Japan

    International Nuclear Information System (INIS)

    Sakai, M.

    1976-01-01

    The status and future developments of heavy ion facilities in Japan are presented. New tandem, linear accelerator and Mumatron for studies of nuclear matter are under construction. Mumatron which provides 500 MeV/nucleon with rather small intensity consists of four parts, namely, Wideroe-type linear accelerator, Alvarez-type linear accelerator, Cockcroft-Walton accelerator and synchrotron. Mumatron is expected not only to open an entirely new field of nuclear physics but for application to the cancer therapy

  16. Giant dipole modes in heavy-ion reactions

    International Nuclear Information System (INIS)

    Suraud, E.; Schuck, P.

    1988-07-01

    A detailed study of the excitation of giant dipole modes (GDR) in intermediate energy heavy-ion collisions is presented in the framework of a full (non linearized) Landau-Vlasov equation. After having recalled the basic inputs of this dynamical formalism, within insisting upon the limitations of the Uehling-Uhlenbeck collision integral and upon the introduction of a realistic (isospin dependant) effective interaction, we present our tools for analysing the GDR in the simple case of isolated nuclei. We then pass on to simulations of collisions and discuss in some detail isospin modes in the model 12 Be + 12 C reaction. Results obtained for the energy of the excited dipole mode are in agreement with what is expected for excited, rotating, giant dipole oscillations in deformed nuclei

  17. Fission in intermediate energy heavy ion reactions

    International Nuclear Information System (INIS)

    Wilhelmy, J.B.; Begemann-Blaich, M.; Blaich, T.; Boissevain, J.; Fowler, M.M.; Gavron, A.; Jacak, B.V.; Lysaght, P.S.; Britt, H.C.; Fields, D.J.; Hansen, L.F.; Lanier, R.G.; Massoletti, D.J.; Namboodiri, M.M.; Remington, B.A.; Sangster, T.C.; Struble, G.L.; Webb, M.L.; Chan, Y.D.; Dacai, A.; Harmon, A.; Leyba, J.; Pouliot, J.; Stokstad, R.G.; Hansen, O.; Levine, M.J.; Thorn, C.E.; Trautmann, W.; Dichter, B.; Kaufman, S.; Videbaek, F.; Fraenkel, Z.; Mamane, G.; Cebra, D.; Westfall, G.D.

    1989-01-01

    A systematic study of reaction mechanisms at intermediate energies (50-100 MeV/A) has been performed at the Lawrence Berkeley Laboratory's BeValac using medium weight projectiles on medium and heavy element targets. A gas and plastic phoswich detector system was employed which gave large geometric coverage and a wide dynamic response. The particles identified with the gas detectors could be characterized into three components - intermediate mass fragments (IMF), fission fragments (FF) and heavy residues (HR). Major observed features are: The reaction yields are similar in the 50 to 100 MeV/A range, central collisions have high multiplicty of IMF's with broad angular correlations consistent with a large participant region, effects of final state Coulomb interactions are observed and give information on the size and temporal behavior of the source, true fission yields are dependent on target fissility and correlated with relatively peripheral collisions. Analysis of fission and evaporation yields implies limiting conditions for which fission decay remains a viable deexcitation channel. (orig.)

  18. Fission in intermediate energy heavy ion reactions

    International Nuclear Information System (INIS)

    Wilhelmy, J.B.; Begemann-Blaich, M.; Blaich, T.

    1989-01-01

    A systematic study of reaction mechanisms at intermediate energies (50--100 MeV/A) has been performed at the Lawrence Berkeley Laboratory's BeValac using medium weight projectiles on medium and heavy element targets. A gas and plastic phoswich detector system was employed which gave large geometric coverage and a wide dynamic response. The particles identified with the gas detectors could be characterized into three components - intermediate mass fragments (IMF), fission fragments (FF) and heavy residues (HR). Major observed features are: the reaction yields are similar in the 50 to 100 MeV/A range, central collisions have high multiplicity of IMF's with broad angular correlations consistent with a large participant region, effects of final state Coulomb interactions are observed and give information on the size and temporal behavior of the source, true fission yields are dependent on target fissility and correlated with relatively peripheral collisions. Analysis of fission and evaporation yields implies limiting conditions for which fission decay remains a viable deexcitation channel. 7 figs

  19. Studies of relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Madansky, L.

    1989-01-01

    This report presents the progress in our program of Relativistic Heavy Ion studies. The first phase of experiments on lepton pairs is almost complete and the results from the initial part of this program are presented in copies of three publications. It appears that the origin of lepton pairs is the annihilation of pions. The evidence for this seems to be the shape of the dilepton mass spectrum, the cross-section as a function of energy which seems to scale with pion production, and the general kinematic behavior of the lepton pairs themselves. We present progress on the development of Ring Imaging Cerenkov counters for dilepton observations in general, and a short report on a high resolution method counter proposal that could be adapted to RHIC counters in general. Publication of results on hyperon polarization with incident polarized proton beams is also presented. These results use the phenomenological approach that could be useful in understanding hyperon production in heavy ion collisions. In this connection, a proposal for studying high density nuclear matter with incident antiprotons is presented. Progress on the TPC detectors developed by the BNL group for heavy ion research is reported, along with recent analysis of polarization with incident silicon beams. Finally, the most recent results on subthreshold antiproton production is presented. These latter results are several orders of magnitude more than expected and they point to some kind of coherent hadronic phenomena even at extremely low energies

  20. Kinematic relations in heavy-ion reactions

    International Nuclear Information System (INIS)

    Gippner, P.; Kalpakchieva, R.

    1988-01-01

    The present work gives a short overview of the non-relativistic kinematics of nuclear reactions derived on the basis of the conservation laws of energy and linear momentum. Section 2 contains kinematic relations valid for two-body reactions, sections 3 makes use of these relations to describe sequential fission as a special case of reactions with three particles in the exit channel. It is the aim of this work to comprise the kinematic formulae essential for planning of experiments, data analysis and critical examination of the obtained results. (author)

  1. Multifragmentation in relativistic heavy ion reactions

    International Nuclear Information System (INIS)

    Trautmann, W.

    1996-11-01

    Multifragmentation is the dominant decay mode of heavy nuclear systems with excitation energies in the vicinity of their binding energies. It explores the partition space associated with the number of nucleonic constituents and it is characterized by a multiple production of nuclear fragments with intermediate mass. Reactions at relativistic bombarding energies, exceeding several hundreds of MeV per nucleon, have been found very efficient in creating such highly excited systems. Peripheral collisions of heavy symmetric systems or more central collisions of mass asymmetric systems produce spectator nuclei with properties indicating a high degree of equilibration. The observed decay patterns are well described by statistical multifragmentation models. The present experimental and theoretical studies are particularly motivated by the fact that multifragmentation is being considered a possible manifestation of the liquid-gas phase transition in finite nuclear systems. From the simultaneous measurement of the temperature and of the energy content of excited spectator systems a caloric curve of nuclei has been obtained. The characteristic S-shaped behavior resembles that of ordinary liquids. Signatures of critical phenomena in finite nuclear systems are searched for in multifragmentation data. These studies, supported by the success of percolation in reproducing the experimental mass or charge correlations, concentrate on the fluctuations observed in these observables. Attempts have been made to deduce critical-point exponents associated with multifragmentation. (orig.)

  2. On intermediate structures in heavy ion reactions

    International Nuclear Information System (INIS)

    Rotter, I.

    1977-01-01

    The conceptions of the nuclear reaction theory are reinvestigated on the basis of the continuum shell model. The correlation of the resonance states via the continuum can lead to intermediate structures in the cross section. (Auth.)

  3. 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...

  4. Selective population of high-j states via heavy-ion-induced transfer reactions

    International Nuclear Information System (INIS)

    Bond, P.D.

    1982-01-01

    One of the early hopes of heavy-ion-induced transfer reactions was to populate states not seen easily or at all by other means. To date, however, I believe it is fair to say that spectroscopic studies of previously unknown states have had, at best, limited success. Despite the early demonstration of selectivity with cluster transfer to high-lying states in light nuclei, the study of heavy-ion-induced transfer reactions has emphasized the reaction mechanism. The value of using two of these reactions for spectroscopy of high spin states is demonstrated: 143 Nd( 16 O, 15 O) 144 Nd and 170 Er( 16 O, 15 Oγ) 171 Er

  5. Heavy ion reactions: an experimental vista

    International Nuclear Information System (INIS)

    Stokstad, R.G.

    1977-01-01

    Examples of recent experiments in the areas of fusion and deep-inelastic scattering are presented and discussed. Emphasis is placed on the importance of individual nucleons in the fusion process, the effects of high angular momentum, and the understanding of compound nuclear decay. Experiments on deep inelastic scattering are entering a new stage in which important parameters of the reaction mechanism are now open to investigation. Primarily through coincidence measurements, direct information on the angular momentum transferred in a collision and on the time scale of decay is being obtained

  6. Coulomb dissociation in relativistic heavy ion reactions

    International Nuclear Information System (INIS)

    Mercier, M.T.

    1982-01-01

    Targets of 12 C, 59 Co, 89 Y, 197 Au and 238 U were bombarded by 2.1 GeV/A 1 H, 12 C and 20 Ne projectiles using the SuperHILAC and BEVATRON facilities at Lawrence Berkeley Laboratory (LBL). The beam flux was calculated by monitoring the decay of 11 C produced from the 12 C(projectile,projectile n) 11 C reaction. Residual gamma-ray activity from the Co, Y, Au and U targets was collected in order to trace the decay of several reaction products. The experiment focused on the calculation of cross sections for the formation of products with one neutron removed from the various target nuclei. Corrections to the saturation activity of each product were made for detector efficiency, gamma-ray absorption in the target, gamma-ray branching, beam geometry and secondary reactions. These date are shown to be inconsistent with a geometrical form given by sigma varies as (A/sub p/sup 1/3/ + A/sub t/sup 1/3/ - b) where b is a universal constant. In fact the data indicates the b = A/sub t/sup 1/3/. Instead the data can be fit quite well by a simple empirical relation, sigma/sub emp/ = 12.0 mb A/sub p/sup 1/3/ A/sub t/sup 1/3/. It is demonstrated that an empirical fit which varies as A/sub t/sup 1/3/ is also consistent with projectile fragmentation data measured by a group at LBL. In addition these data are compared to a theoretical prediction which is the sum of a renormalized Glauber term and a term which represents the contribution due to Coulomb or electromagnetic dissociation (ED). The theoretical predictions are quite low for the 12 C projectile data and high for the 20 Ne projectile data. The systematic trends from the comparison seem to indicate that theoretical prediction for the ED contribution is rising too fast as a function of projectile for a given target

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

    Science.gov (United States)

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

    1991-01-01

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

  8. Intermediate energy heavy ion reactions. A program for CELSIUS

    International Nuclear Information System (INIS)

    Jakobsson, B.

    1986-02-01

    The accelerator system under construction in Uppsala with the ECR-source + the K equals 200 synchrocyclotron + the CELSIUS synchrotron ring for storage, cooling and acceleration opens up possibilities for a very fruitful heavy ion physics program. Some recently obtained results and some recent ideas on intermediate energy reactions are discussed and speculations are made about some experiments where the unconventional qualities of CELSIUS beams could be utilized. (author)

  9. Stopping power for heavy ions in gases: a comparative study

    International Nuclear Information System (INIS)

    Diwan, P.K.; Singh, Lakhwant; Singh, Gurinder; Shyam Kumar

    1999-01-01

    The accurate knowledge of stopping power for heavy ions in gases is of paramount importance in nuclear reaction studies for the identification of reaction products involving ΔE-E telescope detectors. In the present work, it has been calculated the stopping power values for different heavy ions, such as Ne, Ar, Cu, Kr and Ag in various gas absorbers like H 2 , He, N 2 , Ne, Ar, Kr and Xe in the energy domain ∼ 2.5-6 MeV/n using the SRIM-98 code recently developed by Ziegler and the formulations of Benton and Henke, Hubert et al, Mukherjee and Nayak and Northcliffe and Schilling. This study has been undertaken in order to establish the validity of various semiempirical formulations for gas targets

  10. Application of Wigner-transformations in heavy ion reactions

    International Nuclear Information System (INIS)

    Esbensen, H.

    1981-01-01

    One of the main features of inelastic heavy ion reactions is the excitation of collective surface vibrations. It is discussed a model, based on Wigner transformations and classical dynamics, that gives a semiclassical description of the excitation of surface vibrations due to the Coulomb and nuclear interaction in heavy ion collisions. The treatment consists of three stages, viz. the preparation of classical initial conditions compatible with the quantal ground state of surface vibrations, the dynamical evolution of the system governed by Liouville's equation (i.e. classical mechanics) and finally the interpretation of final results after the interaction in terms of excitation probabilities, elastic and inelastic cross sections etc. The first and the last stage are exact and based on the Wigner transformations while the time evolution described by classical mechanics is an approximation. Application examples are given. (author)

  11. Central collisions in intermediate energy heavy-ion reactions

    International Nuclear Information System (INIS)

    Wong, C.Y.

    1979-01-01

    The critical collisions in intermediate energy heavy-ion reactions are examined from both a microscopic and macroscopic viewpoint. In the microscopic description the proper tool is the extended TDHF approximation involving both the mean field and the particle collisions. To understand the underlying physics, the effect of the mean field and the effect of particle collisions are studied separately. It is found that th sudden increase in the density of the overlapping region can cause the volcano effect, leading to the complete disintegration of one of the nuclei. The self-consistent mean field also gives rise to the bunching instability when the two Fermi spheres of the colliding nucleons separate. The collision between nucleons, on the other hand, leads to irreversible dissipation, thermalization, and the possibility of a hydrodynamical description of the dynamics. Next is studied the dynamics of central collisions using the hydrodynamical description for many combinations of targets and projectiles at different energies. The formation of shock waves, sidesplash, and the complete disintegration of the whole nucleus are examined. Nuclear viscosity is found to affect the angular distribution of the reaction products and also the maximum compression ratio achieved during the collision. 28 references

  12. Light particle and gamma ray emission measurements in heavy-ion reactions. Progress report

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1982-01-01

    The development of a position-sensitive neutron detector and a data acquisition system at HHIRF for studying light particle emission in heavy ion reactions is described. Results are presented and discussed for the reactions 12 C + 158 Gd, 13 C + 157 Gd, and 20 Ne + 150 Nd

  13. Dynamics of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

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

    1979-01-01

    Large-amplitude collective motion in fission and heavy-ion reactions is studied by solving classical equations of motion for the time evolution of the nuclear shape. In the nuclear potential energy of deformation, the generalized surface energy was calculated by means of a double volume integral of a Yukawa-plus-exponential function, which was obtained by requiring that two semi-infinite slabs of constant-density nuclear matter have minimum energy at zero separation. The collective kinetic energy is calculated for nuclear flow that is a superposition of incompressible, nearly irrotational collective-shape motion and rigid-body rotation. Nuclear dissipation is included by means of the Rayleigh dissipation function, which depends upon the physical mechanism that converts collective energy into internal energy. For both ordinary two-body viscosity and a combined wall and window one-body dissipation, fission-fragment kinetic energies are calculated for the fission of nuclei throughout the periodic table and compare with experimental results. Finally, the one-body dynamics of nucleons inside a cylinder colliding with a moving piston is explicitly studied by solving exactly the collisionless Boltzmann equation for the distribution function. By examining the relative phases of the pressure at the piston and the piston's velocity, a dissipative force and an elastic restoring force can be separately identified. 9 references

  14. Heavy-ion reactions at energies near the Coulomb barrier

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1991-01-01

    The title covers a very broad area of both experimental and theoretical studies. The common characteristic of heavy-ion collisions at these energies, compared to what is usually seen at higher energies, is the important interplay between different reaction channels or internal degrees of freedom. The couplings between the various channels can result in important multistep contributions to a given channel. These often have to be treated explicitly, for example by solving the appropriate set of coupled equations. In contrast, at higher energies the effects of these couplings frequently can be represented in a simple, average way, as is done when one introduces an imaginary part to the optical potential for elastic scattering. At first, it might be thought that the possible importance of multistep transitions would be a strong disadvantage of working at these energies. However, although the analysis of the data becomes more complicate, the study of these terms and their interferences can be a rich source of information. In particular, it can tell us, indirectly, something about transitions between two excited states. Overviews of some of these phenomena have been presented elsewhere; here I have selected two topics as representative. Even then I cannot go into much detail, so perhaps this paper is best regarded as providing some references as the stating point for a literature search exclamation point

  15. Chaotic scattering in heavy-ion reactions with mass transfer

    International Nuclear Information System (INIS)

    Rodriguez Padron, Emilio; Guzman Martinez, Fernando

    1998-01-01

    The role of the mass transfer in heavy ion collisions is analyzed in the framework of a simple semi phenomenological model searching for chaotic scattering effects. The model couples the relative motion of the ions to a collective degree of freedom. The collective degree of freedom is identified by the mass asymmetry of the system. A Saxon-Woods potential is used for nucleus-nucleus interaction whiles a harmonic potential rules the temporal behaviour of the collective degree of freedom. This model shows chaotic scattering which could be an explanation for certain types of cross-section fluctuations observed in this kind of reactions

  16. Theory of nuclear heavy-ion direct transfer reactions

    International Nuclear Information System (INIS)

    Crowley, B.J.B.

    1979-01-01

    We review the distorted-wave approach to direct transfer reactions and draw attention to some of the shortcomings of current theories. We show that a reformulated form of the distorted-wave Born approximation (DWBA) for transfer can lead to important simplifications of the theory, which are valid for nuclear heavy-ion induced reactions at energies > or approx. =MeV/nucleon. In particular, in the semiclassical limit, it leads to a new and simple formula for the transfer t-matrix which includes all the essential physics while offering several important advantages over standard ''full-recoil finite-range'' DWBA. One such advantage is that the new formula is more transparent in that it is amendable to interpretation and analytical manipulation. At high-energy it is shown to reduce to one earlier deduced using eikonal-DWBA. The conditions for the validity of the new theory are discussed in detail. They are shown to be generally well satisfied for small-mass transfer between heavy-ions at energies at or above those particularly favour transfer (> or approx. =10 MeV/nucleon for transfer of valence nucleons). The restriction to small mass is not due to any recoil approximation; in fact, it is only a necessary restriction at certain energies. The theory treats recoil exactly. Consideration of the optimum dynamical conditions for transfer leads to a set of matching conditions. The presence of hitherto neglected absorption, arising from dynamical effects of poor matching, it suggested and qualitatively discussed. Condition under which such absorption may be neglected are derived. Results of numerical calculations are presented showing that the theory is capable of good agreement with standard full-recoil finite-range DWBA, and that it is capable of giving at least as good an account of experimental data for nucleon-transfer between heavy-ions at energies approx.10 MeV/nucleon

  17. Studies of complex fragment emission in heavy ion reactions: Progress report, September 1, 1986 through August 31, 1987

    International Nuclear Information System (INIS)

    Sobotka, L.G.

    1987-01-01

    The production of large fragments, fragments with mass between light particles and fission fragments, in intermediate and high energy nuclear reactions has fostered the proposal of a number of novel reaction mechanisms. These include liquid-vapor equilibrium and nuclear shattering. Temporarily left in the wake of these exciting proposed mechanisms was the old standard, statistical decay of compound nuclei. To be sure, the standard treatment of compound nucleus decay did not deal with large fragment production. However, this omission was not due to any fundamental deficiency of statistical models, but rather an uncertainty concerning exactly how to splice large fragment emission into statistical models. A large portion of our program deals with this problem. Specifically, by studying the yields of large fragments produced in sufficiently low energy reactions we are attempting to deduce the asymmetry and l-wave dependence of large fragment emission from compound nuclear intermediates. This, however, is only half of the problem. Since the novel mechanisms proposed for large fragment emission were spawned by intermediate and high energy reaction data, we must also realize the relevance of the compound nucleus mechanisms at high energies. It is not unreasonable to suspect that compound nucleus-like objects are formed with less than complete momentum transfer and perhaps less than complete mass transfer. Therefore the study of large fragment production in low energy reactions should go hand in hand with the study of energy, mass, and angular momentum transfer in non-compound reactions. This thread joins the apparently divergent subjects covered in this report. 39 refs., 24 figs., 2 tabs

  18. Studies of complex fragment emission in heavy ion reactions: Progress report, September 1, 1987--August 31, 1988

    International Nuclear Information System (INIS)

    Sobotka, L.G.

    1988-01-01

    The production of large fragments, fragments with mass between light particles and fission fragments, in intermediate and high energy nuclear reactions has fostered the proposal of a number of novel reaction mechanisms. These include liquid-vapor equilibrium and nuclear shattering. Temporarily left in the wake of these exciting proposed mechanisms was the old standard, statistical decay of compound nuclei. To be sure, the standard treatment of compound nucleus decay did not deal with large fragment production. However, this emission was not due to any fundamental deficiency of statistical models, but rather an uncertainty concerning exactly how to splice large fragment emission into statistical models. A large portion of our program deals with this problem. Specifically, by studying the yields of large fragments produced in sufficiently low energy reactions we are attempting to deduce the asymmetry and l-wave dependence of large fragment emission from compound nuclear intermediates. This, however, is only half of the problem. Since the novel mechanisms proposed for large fragment emission were spawned by intermediate and high energy reaction data, we must also realize the relevance of the compound nucleus mechanisms at high energies. It is not unreasonable to suspect that compound nucleus-like objects are formed with less than complete momentum transfer and perhaps less than complete mass transfer. Therefore the study of large fragment production in low energy reactions should go hand in hand with the study of energy, mass, and angular momentum transfer in incomplete fusion and non-compound reactions. This thread joins the apparently divergent subjects covered in this report

  19. Dynamical calculations of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

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

    1984-01-01

    With the goal of determining the magnitude and mechanism of nuclear dissipation from comparisons of predictions with experimental data, we describe recent calculations in a unified macroscopic-microscopic approach to large-amplitude collective nuclear motion such as occurs in fission and heavy-ion reactions. We describe the time dependence of the distribution function in phase space of collective coordinates and momenta by a generalized Fokker-Planck equation. The nuclear potential energy of deformation is calculated as the sum of repulsive Coulomb and centrifugal energies and an attractive Yukawa-plus-exponential potential, the inertia tensor is calculated for a superposition of rigid-body rotation and incompressible, nearly irrotational flow by use of the Werner-Wheeler method, and the dissipation ensor that describes the conversion of collective energy into single-particle excitation energy is calculated for two prototype mechanisms that represent opposite extremes of large and small dissipation. We solve the generalized Hamilton equations of motion for the first moments of the distribution function to obtain the mean translational fission-fragment kinetic energy and mass of a third fragment that sometimes forms between the two end fragments, as well as dynamical thresholds, capture cross sections, and ternary events in heavy-ion reactions. 33 references

  20. A few aspects of intermediate energy heavy ion reactions

    International Nuclear Information System (INIS)

    Guet, C.

    1982-10-01

    Some aspects of reactions induced by intermediate energy heavy ions, with a special emphasis of 85 MeV/nucleon 12 C data, are discussed and compared to low energy and relativistic energy features. Transition from mean field to independant nucleon picture is advocated by an increase of nuclear transparency illuminated by reaction cross section estimations. Projectile-like fragment distributions, while demonstrating a typical high energy fragmentation behaviour, exhibit low energy regime distortions. Light fragments, associated to large parallel momentum transfer may result from total explosion. Proton emission is investigated and discussed in terms of opposite models such as thermal equilibrium and nucleon-nucleon scattering. First pion production data are well explained by single nucleon-nucleon inelastic scattering

  1. Study on broad beam heavy ion CT

    International Nuclear Information System (INIS)

    Ohno, Yumiko; Kohno, Toshiyuki; Sasaki, Hitomi; Nanbu, S.; Kanai, Tatsuaki

    2003-01-01

    To achieve the heavy ion radiotherapy more precisely, it is important to know the distribution of the electron density in a human body, which is highly related to the range of charged particles. From a heavy ion CT image, we can directly obtain the 2-D distribution of the electron density in a sample. For this purpose, we have developed a broad beam heavy ion CT system. The electron density was obtained using some kinds of solutions targets. Also the dependence of the spatial resolution on the target size and the kinds of beams was estimated in this work using cylinders targets of 40, 60 and 80 mm in diameter, each of them has a hole of 10 mm in diameter at the center of it. (author)

  2. Dilepton and vector meson production in heavy-ion reactions

    International Nuclear Information System (INIS)

    Wolf, Gy.

    1997-01-01

    A nonperturbative dynamical study of dilepton an vector meson production in heavy-ion collisions from 1 to 2 GeV/A bombarding energies is presented incorporating all known sources relevant in this energy range. The dynamical evolution of the nucleus-nucleus collision is described by a transport equation of the Boltzmann-Uehling-Uhlenbeck type evolving phase-space distribution functions for nucleons, baryon resonances, pions, η's, ρ's and σ's with their isospin degrees of freedom. In particular, the sensitivity of the calculated yields to predicted changes of the ρ and ω mesons in dense matter is investigated. (author)

  3. 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...

  4. Fusion hindrance in reactions with very heavy ions: Border between normal and hindered fusion

    International Nuclear Information System (INIS)

    Shen Caiwan; Li Qingfeng; Boilley, David; Shen Junjie; Abe, Yasuhisa

    2011-01-01

    The fusion hindrance in heavy-ion collisions is studied in the framework of the two-center liquid drop model. It appears that the neck and the radial degrees of freedom might both be hampered by an inner potential barrier on their path between the contact configuration to the compound nucleus. Heavy-ion reactions with and without the two kinds of fusion hindrance are classified through systematic calculations. It is found that the number of reactions without radial fusion hindrance is much smaller than that without neck fusion hindrance, and for both kinds of fusion hindrance the number of reactions without fusion hindrance at small mass-asymmetry parameter α is smaller than that at large α. In the formation of a given compound nucleus, if a reaction with α c is not hindered, then other reactions with α>α c are also not hindered, as is well known experimentally.

  5. Resume and discussion of session on direct heavy ion reactions

    International Nuclear Information System (INIS)

    Hansen, O.

    1983-01-01

    A conference divides into sessions, but the physics does not always respect such divisions. I found the subject of barrier penetrabilities viewed in a coupled channels picture new, exciting and central to all heavy-ion reaction dynamics. The subject was discussed in bits and pieces over three different sessions, partly in the talks by Winther, Landowne, Braun-Munzinger and Broglia, and partly from the floor by the same people and by Smilanski, I have concentrated on that subject alone and I therefore must apologize to the speakers in my session who covered different material, that definitely merited further discussions. Also, I apologize to other session chairmen, whose territory I have invaded. (orig.)

  6. Studying extremely peripheral collisions of relativistic heavy ions

    International Nuclear Information System (INIS)

    Fatyga, M.

    1990-01-01

    Relativistic heavy ion facilities have been proposed (and in some cases constructed) with an intent to search for a new state of matter, a quark gluon plasma. As with all tools in the experimental physics, one should always search for ways in which relativistic heavy ions can be used to study physical phenomena beyond this original goal. New possibilities for a study of higher order photonuclear excitations in extremely peripheral collisions of relativistic heavy ions are discussed in this contribution. Data on the electromagnetic and nuclear fragmentation of a 14.6Gev/nucleon 28 Si projectile are presented

  7. Study of the multi-fragment production in asymmetric heavy ion reactions at E/A = 600 MeV

    International Nuclear Information System (INIS)

    Hubele, J.C.

    1992-03-01

    In this thesis the fragmentation of Au projectiles in collisions with light target nuclei ( 12 C, 27 Al, 64 Cu) is studied at a projectile energy of 600 MeV per nucleon. For the description of an event three observables are used: the multiplicity M lp of the light particles, the largest observed charge Z max of the projectile fragments, as well as a newly introduced obsevable Z bound , which is defined as the sum of all charge contained in complex projectile fragments (Z ≥ 2). By means of this observable different exit channels can be identified: the formation of a heavy residual nucleus by evaporation of light particles, the binary fission, the decay into IMF's (3 ≤ Z ≤ 30) and the complete decay into light particles. At the applied incident energy in the case of Au+Cu reactions each of these decay channels can be realized. The observables Z bound and M lpp are proved as suited quantities for the reconstruction of the impact parameter. Furthermore independently on the target a universal relation between Z bound and the multiplicity distribution of medium-heavy fragments is found. By simple model assumptions it is made plausible that Z bound is correlated both with the size of the projectile residue and in the mean with its excitation energy. For the characterization of the decay into IMF's the multiplicity M imf of these fragments is applied. For all three targets with increasing centrality first an increasing of the mean fragment multiplicities to maximal values of 3-4 is observed. In the case of the Cu target and suggestively also at the Al target in the most central collisions again a decreasing of the multiplicity is found. The universal Z bound behaviour is a hint to a - at least partial - equilibration of the primary projectile residue before the decay. (HSI) [de

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  9. FOBOS - a 4π-fragment spectrometer for heavy-ion reaction products

    International Nuclear Information System (INIS)

    Ortlepp, H.G.; Schilling, K.D.

    1992-06-01

    The FOBOS detector presently under construction at Dubna is intended for heavy ion reaction studies in the bombarding energy range of 10...100 AMeV. It will consist of a 'gas-ball' of 30 position-sensitive avalanche counters and 30 axial ionization chambers behind them, a shell of 190 scintillation counters surrounding the gas ball and a forward phoswich array. All charged reaction products may be measured in a wide dynamic range and in a geometry covering a substantial part of 4π. Special developments were necessary concerning the mechanical construction, the detector design, the evacuation and gas supply and the electronics. Presently individual detector modules are being tested at the beam of the U-400 heavy ion cyclotron of the Laboratory of nuclear reactions. (orig.)

  10. Mass and angular distributions of the reaction products in heavy ion collisions

    Science.gov (United States)

    Nasirov, A. K.; Giardina, G.; Mandaglio, G.; Kayumov, B. M.; Tashkhodjaev, R. B.

    2018-05-01

    The optimal reactions and beam energies leading to synthesize superheavy elements is searched by studying mass and angular distributions of fission-like products in heavy-ion collisions since the evaporation residue cross section consists an ignorable small part of the fusion cross section. The intensity of the yield of fission-like products allows us to estimate the probability of the complete fusion of the interacting nuclei. The overlap of the mass and angular distributions of the fusion-fission and quasifission products causes difficulty at estimation of the correct value of the probability of the compound nucleus formation. A study of the mass and angular distributions of the reaction products is suitable key to understand the interaction mechanism of heavy ion collisions.

  11. Hyperfine interaction studies with pulsed heavy-ion beams

    International Nuclear Information System (INIS)

    Raghavan, P.

    1985-01-01

    Heavy-ion reactions using pulsed beams have had a strong impact on the study of hyperfine interactions. Unique advantages offered by this technique have considerably extended the scope, detail and systematic range of its applications beyond that possible with radioactivity or light-ion reaction. This survey will cover a brief description of the methodological aspects of the field and recent applications to selected problems in nuclear and solid state physiscs illustrating its role. These include measurements of nuclear magnetic and electric quadrupole moments of high spin isomers, measurements of hyperfine magnetic fields at impurities in 3d and rare-earths ferromagnetic hosts, studies of paramagnetic systems, especially those exhibiting valence instabilities, and investigations of electric field gradients of impurities in noncubic metals. Future prospects of this technique will be briefly assessed. (orig.)

  12. Light particle and gamma ray emission measurements in heavy ion reactions. Progress report

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1983-01-01

    Studies of neutron and charged particle emission in heavy ion reactions using the facilities at the HHIRF and the new computer facilities at Georgia State are briefly described. A progress report for 1982 to 1983 is combined with a proposal for work to be performed during 1983 to 1984. Present activities and immediate plans for a run already approved by the Program Advisory Committee of the HHIRF are discussed

  13. Application of path integral method to heavy ion reactions, 1. General formalism

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, J; Negishi, T [Tokyo Univ. of Education (Japan). Dept. of Physics

    1976-03-01

    The semiclassical approach for heavy ion reactions has become more and more important in analyzing rapidly accumulating data. The purpose of this paper is to lay a quantum-mechanical foundation of the conventional semiclassical treatments in heavy ion physics by using Feynman's path integral method on the basis of the second paper of Pechukas, and discuss simple consequences of the formalism.

  14. Heavy ion radiative capture. A study of the 12C(12C,γ) reaction using a large germanium detector array

    International Nuclear Information System (INIS)

    Jenkins, D.G.; Lister, C.J.; Carpenter, M.P.

    2002-01-01

    A new technique has been developed to investigate the little-explored phenomenon of heavy ion radiative capture. Employing a state-of-the-art germanium detector array (GAMMASPHERE) in a novel fashion as a sum energy calorimeter it is possible to separate the radiative capture channel from overwhelming competition from particle emission channels with exquisite sensitivity. By studying in detail the decay pathways and the intermediate states populated in the decay, it is possible to learn information relevant to the hypothesis of nuclear molecular states. (author)

  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. 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).

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

    Indian Academy of Sciences (India)

    2014-04-30

    Apr 30, 2014 ... Heavy-ion collision simulations in various classical models are discussed. ... are also simulated in a 3-stage classical molecular dynamics (3S-CMD) ... considered as a weakly-bound cluster of deuteron and 4He nuclei, thus, ...

  18. Heavy ion fusion reactions: comparison among different models

    Energy Technology Data Exchange (ETDEWEB)

    Canto, L F; Carlson, B V; Hussein, M S

    1988-03-01

    A comparison among different ion fusion models is presented. In particular, the multistep aspects of the recently proposed Dinucleus Doorway Model are made explicit and the model is confronted with other compound nucleus limitation models. It is suggested that the latter models provide effective one-step descriptions of heavy ion fusion.

  19. Concluding remarks presented at the Symposium on heavy ion reaction dynamics on the tandem energy region

    International Nuclear Information System (INIS)

    Betts, R.R.

    1988-01-01

    This paper discusses the divisions between different heavy ion reaction processes. Fusion, deep inelastic, quasi-elastic and elastic interactions are discussed in terms of coupled channel calculations. 20 refs., 8 figs

  20. Large fragment production calculations in relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    Seixas de Oliveira, L.F.

    1978-12-01

    The abrasion-ablation model is briefly described and then used to calculate cross sections for production of large fragments resulting from target or projectile fragmentation in high-energy heavy-ion collisions. The number of nucleons removed from the colliding nuclei in the abrasion stage and the excitation energy of the remaining fragments (primary products) are calculated with the geometrical picture of two different models: the fireball and the firestreak models. The charge-to-mass dispersion of the primary products is calculated using either a model which assumes no correlations between proton and neutron positions inside the nucleus (hypergeometric distribution) or a model based upon the zero-point oscillations of the giant dipole resonance (NUC-GDR). Standard Weisskopf--Ewing statistical evaporation calculations are used to calculate final product distributions. Results of the pure abrasion-ablation model are compared with a variety of experimental data. The comparisons show the insufficiency of the extra-surface energy term used in the abrasion calculations. A frictional spectator interaction (FSI) is introduced which increases the average excitation energy of the primary products, and improves the results considerably in most cases. Agreements and discrepancies of the results calculated with the different theoretical assumptions and the experimental data are studied. Of particular relevance is the possibility of observing nuclear ground-state correlations.Results of the recently completed experiment of fragmentation of 213 Mev/A 40 Ar projectiles are studied and shown not to be capable of answering that question unambiguously. But predictions for the upcoming 48 Ca fragmentation experiment clearly show the possibility of observing correlation effects. 78 references

  1. The study of hadron dynamics in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Venema, L.B.

    1994-01-01

    In this thesis, pion emission patterns were studied in two reaction systems Ar + Ca and Au + Au at 1 GeV/u, with the aim to improve the understanding of the pion production in relativistic heavy ion collisions. The study of the high energy tail of the π 0 -momentum spectrum was regarded as promising because of its sensitivity to compression since it did not appear in small reaction systems. Experiments were performed with TAPS together with the Forward Wall of the FoPi-collaboration at GSI. The combined measurement of charged particle multiplicities in the Forward Wall and the particles entering TAPS enabled an exclusive study of the pion production. TAPS was tested in separate experiments and its capabilities were demonstrated by measuring different reaction products, like photons, charged particles and neutrons. The data analysis involved new methods to treat the background contamination below the invariant mass peak of the π 0 -meson due to the geometry of the detector and to perform particle identification in a high particle multiplicity environment. (orig.)

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

    Indian Academy of Sciences (India)

    They are considerably below the heavy-ion results which indicates that a simple scaling of prompt photons as observed in pp is not sufficient to explain the direct photons in central. Pb+Pb reactions. It is also instructive to compare the γ/π0 ratio extracted from heavy-ion data to those from pp and pC in figure 3. The value in ...

  3. Reaction mechanism and spectroscopy of transfer reactions induced by heavy ions

    International Nuclear Information System (INIS)

    Lemaire, M.-C.

    1977-01-01

    The specific features displayed by data on heavy ion elastic and inelastic angular distributions are discussed, and their physical origin is pointed out from semi-classical calculations in counterpart ambiguities in the phenomenological description of the optical potential appear. Two nucleon transfer reactions induced by heavy ions successfully point out important contributions of a two-step process where the transfer is proceeding via target and residual nucleus inelastic excitation. At incident energies not too high above the Coulomb barrier, such process produces clear shape changes between different final state angular distributions. At higher incident energy, the angular distributions are forward peaked and display oscillations for both mechanisms. As for four-nucleon transfer reactions, the existing data suggest that the nucleons are well transferred into a Os relative

  4. Recent progress and new challenges in isospin physics with heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Li Baoan [Department of Physics, Texas A and M University-Commerce, Commerce, TX 75429-3011 (United States)], E-mail: Bao-An_Li@Tamu-Commerce.edu; Chen Liewen [Institute of Theoretical Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: Lwchen@Sjtu.edu.cn; Ko, Che Ming [Cyclotron Institute and Physics Department, Texas A and M University, College Station, TX 77843-3366 (United States)], E-mail: Ko@Comp.tamu.edu

    2008-08-15

    The ultimate goal of studying isospin physics via heavy-ion reactions with neutron-rich, stable and/or radioactive nuclei is to explore the isospin dependence of in-medium nuclear effective interactions and the equation of state of neutron-rich nuclear matter, particularly the isospin-dependent term in the equation of state, i.e., the density dependence of the symmetry energy. Because of its great importance for understanding many phenomena in both nuclear physics and astrophysics, the study of the density dependence of the nuclear symmetry energy has been the main focus of the intermediate-energy heavy-ion physics community during the last decade, and significant progress has been achieved both experimentally and theoretically. In particular, a number of phenomena or observables have been identified as sensitive probes to the density dependence of nuclear symmetry energy. Experimental studies have confirmed some of these interesting isospin-dependent effects and allowed us to constrain relatively stringently the symmetry energy at sub-saturation densities. The impact of this constrained density dependence of the symmetry energy on the properties of neutron stars have also been studied, and they were found to be very useful for the astrophysical community. With new opportunities provided by the various radioactive beam facilities being constructed around the world, the study of isospin physics is expected to remain one of the forefront research areas in nuclear physics. In this report, we review the major progress achieved during the last decade in isospin physics with heavy ion reactions and discuss future challenges to the most important issues in this field.

  5. 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.

  6. Constraining the EOS of Neutron-Rich Nuclear Matter and Properties of Neutron Stars with Heavy-Ion Reactions

    International Nuclear Information System (INIS)

    Li Baoan; Worley, Aaron; Chen, L.-W.; Ko, Che Ming; Krastev, Plamen G.; Wen Dehua; Xiao Zhigang; Zhang Ming; Xu Jun; Yong Gaochan

    2009-01-01

    Heavy-ion reactions especially those induced by radioactive beams provide useful information about the density dependence of the nuclear symmetry energy, thus the Equation of State of neutron-rich nuclear matter, relevant for many astrophysical studies. The latest developments in constraining the symmetry energy at both sub- and supra-saturation densities from analyses of the isopsin diffusion and the π - /π + ratio in heavy-ion collisions using the IBUU04 transport model are discussed. Astrophysical ramifications of the partially constrained symmetry energy on properties of neutron star crusts, gravitational waves emitted by deformed pulsars and the w-mode oscillations of neutron stars are presented briefly.

  7. On-line mass spectometry of nuclear reactions induced by heavy ions

    International Nuclear Information System (INIS)

    Saint Simon, M. de.

    1977-01-01

    The adaptation of the on-line mass-spectrometric technique to the special conditions of heavy ion induced reactions is described. The method is very selective about A and Z, even for the very heavy reaction products in counterpart of the limitation of its applications to the alkaline elements only. This method is used in order to study the effects of angular momentum brought by the projectile in the complete fusion process and in the following neutron evaporation. The analysis of excitation functions shows that the increase in mass of the projectile has not always the effect of increasing the rotation energy of the compound nucleus. The on-line mass spectrometry has allowed to study heavy ion induced fission. Measurements of complementary isotopic distributions of fission products make it possible to explain that the total number of neutrons emitted per fission can be always deduced from the fragment excitation energy. The study of the isotope distribution variance shows that the statistical model for fission is in good agreement with experimental results after taking into account the non-fusion processes [fr

  8. Applications of Wigner transformations in heavy-ion reactions

    International Nuclear Information System (INIS)

    Esbensen, H.

    1981-01-01

    We discuss a model, based on Wigner transformations and classical dynamics, that gives a semiclassical description of the excitation of surface vibrations due to the Coulomb and nuclear interaction in heavy-ion collisions. The treatment will consist of three stages, viz. the preparation of classical initial conditions compatible with the quantal ground state of surface vibrations, the dynamical evolution of the system governed by Liouville's equation (i.e. classical mechanics) and finally the interpretation, of final results after the interaction in terms of excitation probabilities, elastic and inelastic cross-sections, etc. The first and the last stage are exact and based on the Wigher transformations, while the time evolution described by classical mechanics is an approximation. We shall later return to the question of the applicability of this approximation and give some illustrative examples. (orig./HSI)

  9. Resonances and fusion in heavy ion reactions: new models and developments

    International Nuclear Information System (INIS)

    Cindro, N.

    1982-01-01

    Several aspects of the problem of the resonant behaviour of heavy-ion induced reactions are discussed. First, the problem is set in its relation to fundamental nuclear physics and our understanding of nuclear structure. It is suggested that, if the resonant behaviour of heavy-ion reactions is indeed due to the presence of particular configurations in the composite systems, these configurations must have a very specific nature which prevents their mixing with the adjacent states or else other conditons (e.g. low level density) should be met. Further on, the problem of resonant behaviour observed in back-angle elastic scattering and in forward-angle reaction data is discussed. Collisions between heavy ions leading to the composite systems 36 Ar and 40 Ca are used to discuss the apparent lack of correlation between these two sets of data. A way to understand it, based on the fragmentation of broad resonances, is suggested. In the third part the relation between structure in the fusion cross section excitation functions and that in reaction channel cross sections is discussed. Finally, in the fourth part, the orbiting-cluster model of heavy-ion resonances is briefly described and its predictions discussed. Based on this model a list is given of colliding heavy-ion systems where resonances are expected. (author)

  10. Light particle emission in light heavy-ion induced reactions

    International Nuclear Information System (INIS)

    Bozek, E.; Cassagnou, Y.; Dayras, R.

    1982-01-01

    A detailed study was made of the different processes which may compete with fusion in the energy domain where the cross section for fusion deviates from the reaction cross section. Both reactions 14 N + 12 C and 16 O + 10 B were used to form the compound nucleus 26 Al at the same excitation energy of 44 MeV

  11. The Glauber model and heavy ion reaction and elastic scattering cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Mehndiratta, Ajay [Physics Department, Indian Institute of Technology, Guwahati (India); Shukla, Prashant, E-mail: pshukla@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094 (India)

    2017-05-15

    We revisit the Glauber model to study the heavy ion reaction cross sections and elastic scattering angular distributions at low and intermediate energies. The Glauber model takes nucleon–nucleon cross sections and nuclear densities as inputs and has no free parameter and thus can predict the cross sections for unknown systems. The Glauber model works at low energies down to Coulomb barrier with very simple modifications. We present new parametrization of measured total cross sections as well as ratio of real to imaginary parts of the scattering amplitudes for pp and np collisions as a function of nucleon kinetic energy. The nuclear (charge) densities obtained by electron scattering form factors measured in large momentum transfer range are used in the calculations. The heavy ion reaction cross sections are calculated for light and heavy systems and are compared with available data measured over large energy range. The model gives excellent description of the data. The elastic scattering angular distributions are calculated for various systems at different energies. The model gives good description of the data at small momentum transfer but the calculations deviate from the data at large momentum transfer.

  12. Sub-Coulomb heavy ion neutron transfer reactions and neutron orbit sizes

    International Nuclear Information System (INIS)

    Phillips, W.R.

    1976-01-01

    Direct transfer reactions below the Coulomb barrier offer the best means of determining neutron densities near the nuclear surface. This paper describes how heavy ion sub-Coulomb transfer can be used to determine the rms radii of neutron orbits in certain nuclei. The theoretical background is outlined and problems associated with the comparison of experiment and theory are discussed. Experiments performed to calibrate sub-Coulomb heavy ion transfer reactions are presented, and some comments are made on the relative roles of light and heavy ion reactions. Preliminary values for the rms radii of neutron orbits and neutron excesses extracted from recent experiments are given, and some remarks are made concerning the implications of these results for the triton wave function and for the Coulomb energy difference anomaly. (author)

  13. 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.

  14. 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 238 U 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.

  15. Splendor and misery of the distorted wave method applied to heavy ions transfer reactions

    International Nuclear Information System (INIS)

    Mermaz, M.C.

    1979-01-01

    The success and failure of the Distorted Wave Method (DWM) applied to heavy ion transfer reactions are illustrated by few examples: one and multi-nucleon transfer reactions induced by 15 N and 18 O on 28 Si target nucleus performed on the vicinity of Coulomb barrier respectively at 44 and 56 MeV incident energy

  16. Light particle emission measurements in heavy ion reactions: Progress report, June 1, 1987-May 31, 1988

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1988-01-01

    This paper discusses work on heavy ion reactions done at Georgia State University. Topics and experiments discussed are: energy division in damped reactions between 58 Ni projectiles and 165 Ho and 58 Ni targets using time-of-flight methods; particle-particle correlations; and development works on the Hili detector system. 10 refs., 9 figs

  17. Studies in heavy ion activation analysis Pt. 5

    International Nuclear Information System (INIS)

    Ojo, J.F.; Lass, B.D.; Schweikert, E.A.

    1980-01-01

    Nondestructive heavy ion activation analysis has been used to determine the carbon content in various NBS SRM steel samples with a 7.0 MeV 6 Li + beam. The reaction 12 C( 6 Li,αn) 13 N allows for carbon analysis with the only possible interference being beryllium, 9 Be( 6 Li,2n) 13 N. Under interference-free conditions, and employing a post-irradiation etch, the detection limit for carbon analysis in steel was 5 ppm. (author)

  18. Transverse emittance studies of an induction accelerator of heavy ions

    International Nuclear Information System (INIS)

    Garvey, T.; Eylon, S.; Fessenden, T.J.; Hahn, K.; Henestroza, E.

    1991-01-01

    Current amplification of heavy ion beams is an integral feature of the induction linac approach to heavy ion fusion. As part of the Heavy Ion Fusion Accelerator Research program at LBL the authors have been studying the evolution of the transverse emittance of ion beams while they are undergoing current amplification, achieved by longitudinal bunch compression and acceleration. Experiments are conducted on MBE-4, a four beam Cs + induction linac. The space-charge dominated beams of MBE-4 are focused by electrostatic quadrupoles while they are accelerated from nominally 200 keV up to ∼ 1 MEV by 24 accelerating gaps. Initially the beams have currents of typically 4 mA to 10 mA per beam. Early experimental results showed a growth of the normalized emittance by a factor of 2 while the beam current was amplified by up to 9 times its initial value. The authors will discuss the results of recent experiments in which a mild bunch length compression rate, more typical of that required by a fusion driver, has shown that the normalized emittance can be maintained at its injection value (0.03 mm-mr) during acceleration

  19. Pre-compound neutron evaporation in heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Ajay Kumar; Singh, Hardev; Rajesh Kumar; Govil, I.M.; Golda, K.S.; Rakesh Kumar; Datta, S.K.; Yogi, B.K.; Viesti, G.

    2007-01-01

    In the present investigation, exclusive neutron spectra have been measured in coincidence with the observed γ-rays characteristic to the residual nuclei 53 Fe, 55 Fe and 56 Co. In this new experimental study, we have followed the strategy of forming the compound nucleus 58 Ni at the same excitation energy through two different entrance channels viz the mass symmetric reaction 31 P + 27 Al and the mass asymmetric reaction 12 C + 46 Ti

  20. Direct inner shell ionization accompanying heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Sujkowski, Z.

    1987-07-01

    51 V+ 40 Ar (180 MeV) fusion reaction is studied by means of K X-ray-particle-γ-ray coincidences. K X-ray yields associated with various evaporation residues are determined separately for two ionization processes: the direct ionization by the projectile prior to the nuclear interaction and the postcollisional ionization due to the internal conversion of γ-rays. Implications for possible measurements of nuclear reaction times are discussed. 24 refs., 9 figs., 2 tabs. (author)

  1. Heavy ions amorphous semiconductors irradiation study

    International Nuclear Information System (INIS)

    Benmalek, M.

    1978-01-01

    The behavior of amorphous semiconductors (germanium and germanium and arsenic tellurides) under ion bombardment at energies up to 2 MeV was studied. The irradiation induced modifications were followed using electrical parameter changes (resistivity and activation energy) and by means of the transmission electron microscopy observations. The electrical conductivity enhancement of the irradiated samples was interpreted using the late conduction theories in amorphous compounds. In amorphous germanium, Electron Microscopy showed the formations of 'globules', these defects are similar to voids observed in irradiated metals. The displacement cascade theory was used for the interpretation of the irradiation induced defects formation and a coalescence mechanism of growth was pointed out for the vacancy agglomeration [fr

  2. Towards an unambiguous determination of the excitation energy of the projectile in heavy-ion reactions?

    Energy Technology Data Exchange (ETDEWEB)

    Buta, A.M.; Steckmeyer, J.C. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Auger, G. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)] [and others

    2002-03-01

    The excitation energy of the quasi-projectiles produced in heavy-ion collisions is determined for the {sup 58}Ni+{sup 197}Au reactions at 52 and 90 AMeV. A new method is proposed for isolating unambiguously the particles evaporated by the source. It consists in observing them at small angles along the flight direction of the source. (authors)

  3. The heavy-ion total reaction cross-section and nuclear transparancy

    International Nuclear Information System (INIS)

    Rego, R.A.; Hussein, M.S.

    1982-10-01

    The total reaction cross section of heavy ions at intermediate energies is discussed. The special role played by the individual nucleon-nucleon collisions in determining the nuclear transparancy is analysed. Several competing effects arising from the nuclear and Coulomb interactions between the two ions are found to be important in determing σ sub(R) at lower energies. (Author) [pt

  4. The heavy-ion total reaction cross-section and nuclear transparency

    International Nuclear Information System (INIS)

    Rego, R.A.; Hussein, M.S.

    1982-01-01

    The total reaction cross section of heavy ions at intermediate energies is discussed. The special role played by the individual nucleon-nucleon collisions in determining the nuclear transparency is analysed. Several competing effects arising from the nuclear and Coulomb interactions between the two ions are found to be important in determining σ(sub R) at lower energies. (Author) [pt

  5. The effect of correlations on the entropy and hadrochemical composition in heavy ion reactions

    International Nuclear Information System (INIS)

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

    1987-01-01

    It is shown that spatial correlations between the constituent particles of a gas lead to roughly excluded volume type corrections in the equation of state. These corrections will appreciably change the hadrochemical composition of fireballs formed in heavy ion reactions. (author) 29 refs.; 3 figs

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

    Indian Academy of Sciences (India)

    coincidence with gamma rays, fission products, evaporation residues have yielded interesting results which bring out the influence of nuclear structure, nuclear mean field and dynamics on the emission of these particles. Keywords. Light charged particles; heavy-ion induced reactions; particle spectra and angular distri-.

  7. Present status and perspectives of heavy ion studies on cells and organisms

    International Nuclear Information System (INIS)

    Yang, T.C.; Craise, L.M.; Mei Mantong.

    1992-01-01

    Biomedical research of heavy ion radiation has been an unique and highly active field in past two decades. Through these intensive research efforts, significant amount of quantitative and qualitative data, which provide insights into biological effects, have been obtained. RBE and LET relationship has been well established for cell inactivation, somatic mutation, and cancer induction. In addition, the effects of oxygen and cell cycle on radiosensitivity of mammalian cells, exposed to heavy ions, have been examined. In spite of such large quantitative information, there is only very limited understanding of the mechanisms of these effects of heavy ions. It remains to be discovered how heavy ions cause various biological effects and why heavy ions can be so effective in producing these effects. As the understanding of molecular effects of heavy ion increases, the potential use of heavy ions in probing molecular mechanism(s) of mutation and neoplastic cell transformation becomes more evident. The exciting progress of heavy ion research in past decades only leads to more challenging questions. Answers for these interesting questions can be obtained by developing new heavy ion facilities for single particle irradiation, by further studies with modern molecular biology techniques, and by innovative approaches. Knowledge from biomedical heavy ion research will not only enhance our basic understanding of fundamental biological processes, such as repair, cell growth control, differentiation, etc., but also help in assessing health risk of space radiation and in improving animal and plant breeding. Research in heavy ion radiobiology is gradually growing from infant to mature stage. (author)

  8. Collective charge and mass transfer in heavy ion reactions

    International Nuclear Information System (INIS)

    Hahn, J.

    1982-01-01

    In this thesis the dynamics of the charge and mass asymmetry degree of freedom was studied in the framework of the fragmentation theory by means of a time-dependent Schroedinger equation. New is the introduction of a friction potential which describes the coupling of these collective degrees of freedom to the not explicitely treated other collective respectively internal degrees of freedom. Thereby it was shown that the measured widths of the isobaric charge distributions in the 86 Kr+sup(92,98)Mo reaction can be explained mainly by the quantum mechanical uncertainty in the charge asymmetry degree of freedom. The charge equilibration occurring at the begin of a deep inelastic collision can therefore by considered as a quantum mechanical, collective, damped motion which is connected with the excitation of the isovector giant dipole resonance of the nucleus-nucleus system. The study of the mass transfer in the reactions 132 Xe+ 120 Sn and 86 Kr+ 166 Er shows, how important at the begin of a deep inelastic collision shell structures and their conservation are for a large part of the reaction, even if the elemental distribution show no maxima in the region of magic shell closures. The experimental width are up to 10 MeV/A well described under conservation of the shell structure. (orig./HSI) [de

  9. 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)

  10. Pre-equilibrium emission of nucleons from reactions induced by medium-energy heavy ions

    International Nuclear Information System (INIS)

    Korolija, M.; Holuh, E.; Cindro, N.; Hilscher, D.

    1984-01-01

    Recent data on fast-nucleon emission in heavy-ion-induced reactions are analysed successfully in terms of pre-equilibrium models; it is shown that the relevant parameters of those models preserve the physical meaning they have in light-ion-induced reactions. The initial exciton number obtained from a Griffin-plot analysis and the initial number of degrees of freedom, which is the relevant parameter of the modified HMB model, appear to be approximately equal for a given reaction at a given energy. It is inferred that, for heavy-ion reactions, the determination of such a parameter is substantially dominated by the centre-of-mass energy per nucleon above the Coulomb barrier, in contrast with the results of nucleon-induced reactions

  11. Theory of nuclear reactions, with applications to heavy ion scattering reactions

    International Nuclear Information System (INIS)

    Youssef, M.S.A.

    1981-01-01

    Nuclear science to day, has gained its stature through the pioneer work of both theorists and experimentalists within its two main divisions, Nuclear Reaction and Nuclear Structure theories. Our main interest in this theoretical work in nuclear reaction theory is focused on three topics, come under the headings of three parts which are the constituents of the present paper. Part 1 is concerned with ''Contributions to the theory of Threshold phenomena in nuclear reactions; cluster threshold states in heavy ion reactions''. Part II is devoted to ''Hermiticity of the Laplacian operator, R-matrix theories and direct interaction theory'', while part xII is ascribed to ''Heavy ion transfer reactions and scattering''. The aforementioned selected topics are the backbones of this thesis, which starts with general introduction giving a brief account about the material included in. In each part, investiqations are given in an extended manner through several chapters. Finally, the thesis is ended eith the chapter on ''General Discussions and Conclusions''. Appendices, references, and figure captions are found at the end of each part, the matter which we believe to facilitate much the reading through of the thesis. The first two parts are based (to some extent) on the same formal background (R-matrix, Kapur-Peierls-theories) and they converge to solve some physical problems originating from flux conservation laws in nuclear reactions, while the third part is indirect related to the first two; in principle it joins the other two parts under computational aspects. All of them after all, form the solidarity of the material included in the thesis. (author)

  12. Multifragmentation in intermediate energy 129Xe-induced heavy-ion reactions

    International Nuclear Information System (INIS)

    Tso, Kin.

    1996-05-01

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

  13. Multifragmentation in intermediate energy 129Xe-induced heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Tso, Kin [Univ. of California, Berkeley, CA (United States)

    1996-05-01

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

  14. 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.

  15. Effect of γ-ray emission on transuranium element production cross sections in heavy ion reactions

    International Nuclear Information System (INIS)

    Il'inov, A.S.; Oganesyan, Yu.Ts.; Cherepanov, E.A.

    1980-01-01

    The effect of competition of the γ ray emission with neutron evaporation and of compound nuclei fission induced by heavy ion reactions on the production cross sections for transuranium elements is considered. It is shown that taking account of γ ray emission leads to the broadening of the excitation functions of the (HI, xny) reactions such as 18 O+ 238 U, 40 Ar+ 206 Pb, 40 Ar+ 207 Pb and 40 Ar+ 208 Pb reactions and to the displacement of their maximum toward the higher energies as well as to an increase of the absolute cross sections which is especially strong close to the fusion barrier. Cross sections for the radiative capture of heavy ions by a heavy target nucleus in 40 Ar+ 206 Pb, 40 Ar+ 208 Pb, 48 Ca+ 204 Pb and 48 Ca+ 208 Pb reactions are estimated

  16. Angular evolution of peripheral heavy ion reactions at intermediate energies

    International Nuclear Information System (INIS)

    Blumenfeld, Y.; Chomaz, P.; Frascaria, N.; Garron, J.P.; Jacmart, J.C; Roynette, J.C

    1985-01-01

    Energy spectra and angular distributions of projectile-like fragments have been measured in the vicinity of the grazing angle for the 40 Ar+ 40 Ca and 40 Ar+ 208 Pb reactions at 44MeV/nucleon. Measurements of the 40 Ar+ 40 Ca system at 27MeV/nucleon and 20 Ne+ 208 Pb reaction at 44MeV/nucleon at one angle have also been performed. For fragments with charge and mass close to the projectile numerous deviations from the standard fragmentation model have been observed including rapidly changing shapes of the angular distributions with the fragment mass. Moreover the isotopic distributions and mean fragment velocities are strongly dependent on detection angle. A surface transfer reaction component dominant at the grazing angle can be separated from a second component which cannot be entirely accounted for by a simple fragmentation mechanism

  17. Nuclear momentum distribution and relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    Wong, C.Y.; Blankenbecler, R.

    1980-01-01

    In terms of a direct fragmentation process and a hard-scattering process, the proton-inclusive data for the reaction α + 12 C → p + X have been successfully analyzed. The extracted semiempirical momentum distribution indicates possible evidence of nuclear correlations and final-state interactions. 4 figures

  18. Quasi-Classical Description of Heavy Ion Reactions

    International Nuclear Information System (INIS)

    Luk'yanov, V.K.

    1994-01-01

    A method for calculating the distorted waves for a realistic nuclear complex potential with the Coulomb forces included is developed using the quasi-classical and high energy approximations. The distorted waves are obtained in the analytical form and applications are made to elastic, inelastic scattering and to the one-nucleon transfer reactions. 9 refs., 2 figs

  19. Heavy residues from very mass asymmetric heavy ion reactions

    International Nuclear Information System (INIS)

    Hanold, K.A.

    1994-08-01

    The isotopic production cross sections and momenta of all residues with nuclear charge (Z) greater than 39 from the reaction of 26, 40, and 50 MeV/nucleon 129 Xe + Be, C, and Al were measured. The isotopic cross sections, the momentum distribution for each isotope, and the cross section as a function of nuclear charge and momentum are presented here. The new cross sections are consistent with previous measurements of the cross sections from similar reaction systems. The shape of the cross section distribution, when considered as a function of Z and velocity, was found to be qualitatively consistent with that expected from an incomplete fusion reaction mechanism. An incomplete fusion model coupled to a statistical decay model is able to reproduce many features of these reactions: the shapes of the elemental cross section distributions, the emission velocity distributions for the intermediate mass fragments, and the Z versus velocity distributions. This model gives a less satisfactory prediction of the momentum distribution for each isotope. A very different model based on the Boltzman-Nordheim-Vlasov equation and which was also coupled to a statistical decay model reproduces many features of these reactions: the shapes of the elemental cross section distributions, the intermediate mass fragment emission velocity distributions, and the Z versus momentum distributions. Both model calculations over-estimate the average mass for each element by two mass units and underestimate the isotopic and isobaric widths of the experimental distributions. It is shown that the predicted average mass for each element can be brought into agreement with the data by small, but systematic, variation of the particle emission barriers used in the statistical model. The predicted isotopic and isobaric widths of the cross section distributions can not be brought into agreement with the experimental data using reasonable parameters for the statistical model

  20. Fission before mass equilibration in heavy ion reactions

    International Nuclear Information System (INIS)

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

    2013-01-01

    For compound nucleus (CN) fission, it is expected that the width of the fragment mass distribution is independent of the entrance channel. In quasifission reaction, however, recent experiments reported anomalous broadening of mass distribution for more symmetric systems forming the same compound nucleus in fissile (fissility ∼ 0.8) and less fissile (fissility ∼ 0.7) systems. These measurements have not shown any mass-angle correlation, but width of fission fragment mass distribution was found to be consistently higher than that expected for fusion-fission

  1. Heavy-ion reactions and new trends of nuclear Physics

    International Nuclear Information System (INIS)

    Bernas, M.

    1987-06-01

    On the chart of the nuclei, there are still areas which would deserve to be explored like the Nickel hole on the neutron rich side. We shall illustrate here the progress recently accomplished along this line and compare resulting datas with Hartree Fock Bogoliubov (H.F.B.) calculations performed on those isotopes. It is shown how well-known production reactions like quasi elastic transfer or neutron induced fission have been pushed toward their limits, thanks to improvements in experimental devices, to be usable further apart from stability

  2. Mechanism of nuclear dissipation in fission and heavy-ion reactions

    International Nuclear Information System (INIS)

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

    1986-01-01

    Recent advances in the theoretical understanding of nuclear dissipation at intermediate excitation energies are reviewed, with particular emphasis on a new surface-plus-window mechanism that involves interactions of either one or two nucleons with the moving nuclear surface and also, for dumbbell-like shapes encountered in fission and heavy-ion reactions, the transfer of nucleons through the window separating the two portions of the system. This novel dissipation mechanism provides a unified macroscopic description of such diverse phenomena as widths of isoscalar giant quadrupole and giant octupole resonances, mean fission-fragment kinetic energies and excitation energies, dynamical thresholds for compound-nucleus formation, enhancement in neutron emission prior to fission, and widths of mass and charge distributions in deep-inelastic heavy-ion reactions. 41 refs., 8 figs

  3. Comparative study between hadron and heavy ion dissociation at high energies

    International Nuclear Information System (INIS)

    El-Bakry, Y.M.N.; Abd-Elhalim, S.M.

    2002-01-01

    The present work deals with the dissociation of hadrons and heavy ions at high energies. In investigating hadron nucleus and nucleus-nucleus collisions, it is important to classify the experimental data, into two main classes; the coherent. and incoherent reactions. The coherent production is the main of our study. This process called electromagnetic dissociation (ED) and can be differentiate into coulomb dissociation (CD) and diffraction dissociation (DD). This work explains the experimental data of collisions of hadrons K± (70 GeV/c) and π(340 Gc V/c) and heavy ions 6 L i, 7 L i, 1 2C and1 6O at Dubna energies (3-4.5 A GeV/c)with emulsion target, in the frame of some models and theories which describe the mechanism of ED dissociation

  4. Recent developments in heavy ion deep inelastic reactions

    International Nuclear Information System (INIS)

    Lefort, M.; Ngo, C.

    1979-01-01

    In the first attempts to understand deep inelastic reactions (DIR), the attention was focussed on the dissipation mechanism and simple classical models have been elaborated to describe the dynamical evolution of the mean values of the macroscopic variables. Very early, it has also been realized that the distributions around the mean values were rather broad and that this might reveal the importance of fluctuations which are mainly expected to be statistical fluctuations. In section II, we shall only say a few words about the two classes of models: dynamical evolution and diffusion model, which have been described many time. Each of them accounts for a particular aspect of the DI phenomena. It appeared worthwhile to unify these approaches and to treat on the same footing both dissipation and statistical fluctuations. Microscopic attempts have succeeded in understanding the evolution of the macroscopic degrees which are slow as compared to the intrinsic degrees. In section III we shall briefly discuss them and in section IV we will more extensively see how they can be applied to the computation of multidifferential cross section for DIR. (autho.)

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

    International Nuclear Information System (INIS)

    Beck, F.A.

    1993-01-01

    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.)

  6. 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.).

  7. Experimental studies of heavy-ion slowing down in matter

    International Nuclear Information System (INIS)

    Geissel, H.; Weick, H.; Scheidenberger, C.; Bimbot, R.; Gardes, D.

    2002-08-01

    Measurements of heavy-ion slowing down in matter differ in many aspects from experiments with light particles like protons and α-particles. An overview of the special experimental requirements, methods, data analysis and interpretation is presented for heavy-ion stopping powers, energy- and angular-straggling and ranges in the energy domain from keV/u up to GeV/u. Characteristic experimental results are presented and compared with theory and semiempirical predictions. New applications are outlined, which represent a challenge to continuously improve the knowledge of heavy-ion slowing down. (orig.)

  8. Study of charge exchanges of heavy ions passing through solids

    International Nuclear Information System (INIS)

    Baron, Eric.

    1975-01-01

    The charge state distributions of 1 to 6MeV/nucleon heavy ions (from oxygen to krypton) passing through thin targets of various materials (C, Cu, Ag, Au) are studied. The variation of the average charge state and of the charge state fractions as a function of the thickness of carbon targets ranging from zero to the equilibrium thickness is measured; this allows the calculation of effective cross-sections of the charge changing process. It is also shown that the lower the target atomic number, the higher the average charge state, which is explained by a decrease of the capture cross sections. Finally, a semi-empirical formula predicting the average charge state is proposed, as an extension of Betz's and Nikolaev and Dmitriev's formula [fr

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

    Science.gov (United States)

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

    1998-07-21

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

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

    Science.gov (United States)

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

    1999-02-16

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

  11. Dynamical hindrance to compound nucleus formation in heavy ion reactions

    International Nuclear Information System (INIS)

    Blocki, J.; Feldmeier, H.; Swiatecki, W.J.

    1987-01-01

    A large number of dynamical trajectories corresponding to colliding nuclei, as represented by an idealized, sharp-surfaced liquid-drop model with one-body dissipation are examined. The objective was to delineate quantitatively, within this model, the behaviour of the extra-extra-push energy E XX in its dependence on the mass /or charge/ numbers of the colliding nuclei. Qualitatively, the results are as anticipated on the basis of earlier studies: the appearance of a dynamical limitation on compound nucleus formation beyond a certain threshold locus in the A 1 . A 2 plane, with the energy E XX rising smoothly but rapidly beyond the threshold. The reduction of the two-dimensional function E XX /A 1 ,A 2 / to a one-dimensional function of a mean fissility x m appears possible as a rough approximation. As expected, the mean fissility x and the entrance channel fissility x 0 . The optimum choice appears to be one in which x is given about twice the weight of x 0

  12. 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.

  13. Excitation functions for quasi-elastic transfer reactions induced with heavy ions in bismuth

    International Nuclear Information System (INIS)

    Gardes, D.; Bimbot, R.; Maison, J.; Reilhac, L. de; Rivet, M.F.; Fleury, A.; Hubert, F.; Llabador, Y.

    1977-01-01

    The excitation functions for the production of 210 Bi, 210 Po, sup(207-211)At and 211 Rn through quasi-elastic transfer reactions induced with heavy ions in 209 Bi have been measured. The corresponding reactions involved the transfer of one neutron, one proton, two and three charges from projectile to target. The projectiles used were 12 C, 14 N, 16 O, 19 F, 20 Ne, 40 Ca, 56 Fe and 63 Cu. The experimental techniques involved target irradiations and off-line α and γ activity measurements. Chemical separations were used to solve specific problems. Careful measurements of incident energies and cross sections were performed close to the reaction thresholds

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

    International Nuclear Information System (INIS)

    Moody, K.J.

    1983-07-01

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

  15. Neutron emission in heavy ion induced reactions at 10 MeV/A

    International Nuclear Information System (INIS)

    Benrachi, F.

    1984-01-01

    The neutron emission mechanism in reactions induced by heavy ions (in which a high energy component had already been observed) has been investigated. To get informations on the desexcitation mode which is responsible of that component and on the sharing of the excitation energy between the fragments, a very disymmetric system 14 N+ 165 Ho at E inc=10,5 MeV/a.m.u. was studied. The neutrons are preferentially emitted forward in the direction of the quasi-projectile and are in average highly energetic. The calculations of the excitation energies and of the multiplicities showed that the detected events are mainly coming from peripheral processes with a weak angular momentum exchange. The analysis of the energy spectra and of the invariance cross section maps pointed out a strong asymmetry and then proved that at least two neutron sources were involved in that reaction mechanism. Studying these two components in terms of a sequential mechanism i.e. an emission from the totally equilibrated quasi-target and quasi-projectile, the whole neutron emission could not be explained. To interpret the experimental results, non statistical models with a preequilibrium emission at the collision beginning were used [fr

  16. Light particle emission measurements in heavy ion reactions: Progress report, June 1, 1988--May 31, 1989

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1989-01-01

    We have completed another successful year of experimental work at the Heavy Ion Research Facility (HHIRF) and at Georgia State University (GSU). Since submitting our previous progress report we have completed our paper on neutron emission from products of the reaction 58 Ni + 165 Ho and it has been submitted to Physical Review C. Some of the details of these results are discussed below. We have installed the Vaxstation computer system for which we received supplemental funding from DOE during 1988-89 and it is being used to analyze the Ni + Ho data using the codes Pace and a modified version of Lilita, both of which we have been able to transfer to our Vaxstation systems from the Vax at ORNL with very minimal modification. The Exabyte tape drive which we ordered with the computer system was finally delivered at the end of January after months of delays. It is now being used to scan data tapes from our experiment to study neutron-neutron and neutron-charged-particle momentum correlations using the reaction 32 S + 197 Au at 25 MeV/nucleon. This data analysis can now proceed at a fast pace. Finally, we have continued our developmental work on the Hili detector system at ORNL, and have participated in experiments to study the predictions of the Dyabatic Dynamics model of particle emission using the Ni + Ni system and the HILI detector system

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

    International Nuclear Information System (INIS)

    Okorokov, V.A.

    2013-01-01

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

  18. Squids, supercurrents, and slope anomalies: Nuclear structure from heavy-ion transfer reactions

    International Nuclear Information System (INIS)

    Guidry, M.W.

    1989-01-01

    Within the past five years we have developed experimental techniques to study heavy-ion transfer reactions to high spin states in deformed nuclei. These methods have been turned into a quantitative tool to assess the influence of collective excitation on single-particle and pairing structure. I discuss some of the nuclear structure questions which are being answered in these experiments: How strong is ground state pairing? How does pairing change with angular momentum? Why is two-neutron transfer much stronger than expected at large radial separation? What is the evidence for a nuclear Josephson Effect? What is the evidence for a nuclear Berry phase effect (nuclear SQUID)? Why does one-neutron transfer populate much higher spins than would be naively expected? Conversely, why does two-neutron transfer populate much lower spins than anyone expected? The answer to each of these questions involves the influence of detailed nuclear structure on transfer reactions, and represents quantitative new information about the effect of angular momentum and excitation energy on many-body systems with a finite number of particles. 8 refs., 6 figs

  19. Production of high-energetic photons in the heavy ion reaction 136Xe + 48Ti at ELab = 18.5 MeV/u

    International Nuclear Information System (INIS)

    Enders, G.

    1991-05-01

    The production mechanism for high-energetic photons in heavy ion collisions was studied on the example of the deep inelastic reaction 136 Xe+ 48 Ti at a projectile energy of 18.5 MeV/u in an exclusive experiment, in which photons and heavy reaction fragments were detected in coincidence. (orig.) [de

  20. 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)

  1. Reaction Dynamics and Nuclear Structure Studies of n-Rich Nuclei Around 48Ca via Deep Inelastic Collisions with Heavy-Ions

    International Nuclear Information System (INIS)

    Leoni, S.

    2011-01-01

    The population and γ decay of neutron rich nuclei around 48 Ca has been measured at Legnaro National Laboratory with the PRISMA-CLARA setup, using deep-inelastic collisions on 64 Ni, at 5.9 MeV/A. The reaction properties of the main products are investigated, focusing on total cross-sections and energy integrated angular distributions. Gamma spectroscopy studies are also performed for the most intense transfer channels, making use of angular distributions and polarization measurements to firmly establish spin and parity of the excited states. In the case of 49 Ca candidates for particle-core couplings are investigated and interpreted on basis of lifetime measurements and comparison with model predictions. (author)

  2. Emission of high-energy, light particles from intermediate-energy heavy-ion reactions

    International Nuclear Information System (INIS)

    Ball, J.B.; Auble, R.L.

    1982-01-01

    One of the early surprises in examining reaction products from heavy ion reactions at 10 MeV/nucleon and above was the large yield of light particles emitted and the high energies to which the spectra of these particles extended. The interpretation of the origin of the high energy light ions has evolved from a picture of projectile excitation and subsequent evaporation to one of pre-equilibrium (or nonequilibrium) emission. The time scale for particle emission has thus moved from one that occurs following the initial collision to one that occurs at the very early stages of the collision. Research at ORNL on this phenomenon is reviewed

  3. Nuclear rotational population patterns in heavy-ion scattering and transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, J O; Stoyer, M A [Lawrence Berkeley Lab., CA (USA); Canto, L F; Donangelo, R [Universidade Federal do Rio de Janeiro, RJ (Brazil); Ring, P [Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik

    1991-05-01

    A model of {sup 239}Pu with decoupled neutron is used for theoretical calculations of rotational population patterns in heavy ion inelastic scattering and one-neutron transfer reactions. The system treated in {sup 90}Zr on {sup 239}Pu at the near-barrier energy of 500 MeV and backscattering angles of 180deg and 140deg. The influence of the complex nuclear optical potential is seen to be very strong, and the Nilsson wave function of the odd neutron produces a distinctive pattern in the transfer reaction. (orig.).

  4. PTOLEMY, a program for heavy-ion direction-reaction calculations

    International Nuclear Information System (INIS)

    Gloeckner, D.H.; Macfarlane, M.H.; Pieper, S.C.

    1976-03-01

    Ptolemy is an IBM/360 program for the computation of nuclear elastic and direct-reaction cross sections. It carries out both optical-model fits to elastic-scattering data at one or more energies, and DWBA calculations for nucleon-transfer reactions. Ptolemy has been specifically designed for heavy-ion calculations. It is fast and does not require large amounts of core. The input is exceptionally flexible and easy to use. This report outlines the types of calculation that Ptolemy can carry out, summarizes the formulas used, and gives a detailed description of its input

  5. Identification of mechanisms in heavy ion reactions by measurement of angular correlations

    International Nuclear Information System (INIS)

    Carlin Filho, N.

    1987-01-01

    The identification of reaction mechanisms in light heavy-ion collisions has been performed within the framework of the three body kinematics, by means of angular correlation measurements. The 16 O+ 27 Al, 16 +O+ 28 Si and 10 B+ 27 Al reactions were investigated at Laboratory bombarding energies of 64 MeV, 64 and 48 MeV, respectively. Contributions of transfer-reemission and projectile sequential decay mechanisms were identified by the analysis of the relative kinetic energy of the final state components, excitation energies of the system at the intermediate stages, and also by means of fits to theoretical predictions for the angular correlations. (author) [pt

  6. Isobaric yield ratios and the symmetry energy in heavy-ion reactions near the Fermi energy

    International Nuclear Information System (INIS)

    Huang, M.; Chen, Z.; Kowalski, S.; Ma, Y. G.; Wada, R.; Hagel, K.; Barbui, M.; Bottosso, C.; Materna, T.; Natowitz, J. B.; Qin, L.; Rodrigues, M. R. D.; Sahu, P. K.; Keutgen, T.; Bonasera, A.; Wang, J.

    2010-01-01

    The relative isobaric yields of fragments produced in a series of heavy-ion-induced multifragmentation reactions have been analyzed in the framework of a modified Fisher model, primarily to determine the ratio of the symmetry energy coefficient to the temperature, a sym /T, as a function of fragment mass A. The extracted values increase from 5 to ∼16 as A increases from 9 to 37. These values have been compared to the results of calculations using the antisymmetrized molecular dynamics (AMD) model together with the statistical decay code gemini. The calculated ratios are in good agreement with those extracted from the experiment. In contrast, the values extracted from the ratios of the primary isobars from the AMD model calculation are ∼4 to 5 and show little variation with A. This observation indicates that the value of the symmetry energy coefficient derived from final fragment observables may be significantly different than the actual value at the time of fragment formation. The experimentally observed pairing effect is also studied within the same simulations. The Coulomb coefficient is also discussed.

  7. AFM studies on heavy ion irradiated YBCO single crystals

    International Nuclear Information System (INIS)

    Lakhani, Archana; Marhas, M.K.; Saravanan, P.; Ganesan, V.; Srinivasan, R.; Kanjilal, D.; Mehta, G.K.; Elizabeth, Suja; Bhat, H.L.

    2000-01-01

    Atomic Force Microscopy (AFM) is extensively used to characterise the surface morphology of high energy ion irradiated single crystals of high temperature superconductor - YBCO. Our earlier systematic studies on thin films of YBCO under high energy and heavy ion irradiation shows clear evidence of ion induced sputtering or erosion, even though the effect is more on the grain boundaries. These earlier results were supported by electrical resistance measurements. In order to understand more clearly, the nature of surface modification at these high energies, AFM studies were carried out on single crystals of YBCO. Single crystals were chosen in order to see the effect on crystallites alone without interference from grain boundaries. 200 MeV gold ions were used for investigation using the facilities available at Nuclear Science Centre, New Delhi. The type of ion and the range of energies were chosen to meet the threshold for electronically mediated defect production. The results are in conformity with our earlier studies and will be described in detail in the context of electronic energy loss mediated sputtering or erosion. (author)

  8. Fifth high-energy heavy-ion study

    International Nuclear Information System (INIS)

    1981-10-01

    This was the fifth of a continuing series of summer studies held at LBL to discuss high energy heavy ion collisions. Recently, a similar meeting has been held on alternate years at GSI (Darmstadt); and, in 1979, we held a meeting at LBL exclusively devoted to ultra-relativistic nuclear collisions. Two new features distinguish this study from earlier meetings in the series. First, the energy range for discussion was broadened by including collisions from about 20 MeV/nucleon to the highest available in the cosmic radiation. The lower range, particularly below 100 MeV/nucleon, will be under intense study in the near future with machines such as the upgraded Bevalac, Michigan State University Superconducting Cyclotron, GANIL in France, and the SC at CERN. Recently, the high energy collision regime has been expanded by the successful operation of the CERN ISR with alpha particles. Second, in addition to an extensive program of invited talks, we decided for the first time to actively solicit contributions. Forty-seven individual items from the conference were prepared separately for the data base

  9. Fifth high-energy heavy-ion study

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-01

    This was the fifth of a continuing series of summer studies held at LBL to discuss high energy heavy ion collisions. Recently, a similar meeting has been held on alternate years at GSI (Darmstadt); and, in 1979, we held a meeting at LBL exclusively devoted to ultra-relativistic nuclear collisions. Two new features distinguish this study from earlier meetings in the series. First, the energy range for discussion was broadened by including collisions from about 20 MeV/nucleon to the highest available in the cosmic radiation. The lower range, particularly below 100 MeV/nucleon, will be under intense study in the near future with machines such as the upgraded Bevalac, Michigan State University Superconducting Cyclotron, GANIL in France, and the SC at CERN. Recently, the high energy collision regime has been expanded by the successful operation of the CERN ISR with alpha particles. Second, in addition to an extensive program of invited talks, we decided for the first time to actively solicit contributions. Forty-seven individual items from the conference were prepared separately for the data base. (GHT)

  10. 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.

  11. Bystander effect studies using heavy-ion microbeam

    International Nuclear Information System (INIS)

    Kobayashi, Yasuhiko; Funayama, Tomoo; Sakashita, Tetsuya; Wada, Seiichi; Yokota, Yuichiro; Kakizaki, Takehiko; Hamada, Nobuyuki; Hara, Takamitsu; Fukamoto, Kana; Suzuki, Michiyo; Ni, M.; Furusawa, Yoshiya

    2007-01-01

    We have established a single cell irradiation system, which allows selected cells to be individually hit with defined number of heavy charged particles, using a collimated heavy-ion microbeam apparatus at JAEA-Takasaki. This system has been developed to study radiobiological processes in hit cells and bystander cells exposed to low dose and low dose-rate high-LET radiations, in ways that cannot be achieved using conventional broad-field exposures. Individual cultured cells grown in special dishes were irradiated in the atmosphere with a single or defined numbers of 18.3 MeV/amu 12 C, 13.0 or 17.5 MeV/amu 20 Ne, and 11.5 MeV/amu 40 Ar ions. Targeting and irradiation of the cells were performed automatically according to the positional data of the target cells microscopically obtained before irradiation. The actual number of particle tracks that pass through target cells was detected with prompt etching of the bottom of the cell dish made of ion track detector TNF-1 (modified CR-39). (author)

  12. Calculation for fission decay from heavy ion reactions at intermediate energies

    International Nuclear Information System (INIS)

    Blaich, T.; Begemann-Blaich, M.; Fowler, M.M.; Wilhelmy, J.B.; Britt, H.C.; Fields, D.J.; Hansen, L.F.; Namboodiri, M.N.; Sangster, T.C.; Fraenkel, Z.

    1992-01-01

    A detailed deexcitation calculation is presented for target residues resulting from intermediate-energy heavy ion reactions. The model involves an intranuclear cascade, subsequent fast nucleon emission, and final decay by statistical evaporation including fission. Results are compared to data from bombardments with Fe and Nb projectiles on targets of Ta, Au, and Th at 100 MeV/nucleon. The majority of observable features are reproduced with this simple approach, making obvious the need for involving new physical phenomena associated with multifragmentation or other collective dissipation mechanisms

  13. Collective flow as a probe of heavy-ion reaction dynamics

    International Nuclear Information System (INIS)

    Awes, T.C.

    1997-01-01

    Collective flow of nuclear matter probes the dynamics of heavy-ion reactions and can provide information about the nuclear-matter equation of state. In particular, the incident energy dependences of collective flow may be a sensitive means to deduce the existence of a Quark Gluon Plasma phase in the equation of state. Collective flow measurements from 30 A MeV to 200 A GeV incident energies are briefly reviewed. Preliminary results on collective flow from the WA98 experiment at the CERN SPS are presented

  14. Design study on an intense heavy-ion linac system

    International Nuclear Information System (INIS)

    Okamura, M.; Oguri, Y.; Takahashi, Y.; Hattori, T.; Takeda, O.; Satoh, K.; Tanabe, Y.

    1992-01-01

    A four-vane RFQ cavity is designed for an intense heavy-ion linac system. RFQ-vanes with small tip curvatures are applied in order to improve the RF power efficiency. Beam optical and RF parameters are investigated by beams of numerical methods. Using a scale model, the cavity structure is experimentally optimized. (Author) 7 refs., 4 figs

  15. Jet-Underlying Event Separation Method for Heavy Ion Collisions at the Relativistic Heavy Ion Collider

    OpenAIRE

    Hanks, J. A.; Sickles, A. M.; Cole, B. A.; Franz, A.; McCumber, M. P.; Morrison, D. P.; Nagle, J. L.; Pinkenburg, C. H.; Sahlmueller, B.; Steinberg, P.; von Steinkirch, M.; Stone, M.

    2012-01-01

    Reconstructed jets in heavy ion collisions are a crucial tool for understanding the quark-gluon plasma. The separation of jets from the underlying event is necessary particularly in central heavy ion reactions in order to quantify medium modifications of the parton shower and the response of the surrounding medium itself. There have been many methods proposed and implemented for studying the underlying event substructure in proton-proton and heavy ion collisions. In this paper, we detail a me...

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

    International Nuclear Information System (INIS)

    Tavares, O.A.P.; Medeiros, E.L.; Morcelle, V.

    2010-06-01

    Heavy-ion total reaction cross section measurements for more than one thousand one hundred reaction cases covering 61 target nuclei in the range 6 Li- 238 U, and 158 projectile nuclei from 2 H up to 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. 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)

  18. Heavy-ion induced multinucleon transfer reactions in the 2s--1d shell

    International Nuclear Information System (INIS)

    Olmer, C.

    1975-01-01

    In order to investigate whether new nuclear structure information can be obtained from studying the direct transfer of more than two nucleons using heavy-ion projectiles, we have investigated the 28 Si( 16 O, 12 C) 32 S and 12 C( 14 N,d) 24 Mg reactions as candidates for the direct transfer of four- and twelve-nucleons, respectively. The counter telescope-position sensitive detector kinematic coincidence method--both angular distributions (22 0 less than theta/sub L/ less than 95 0 , E/sub L/ = 55.54 MeV) and excitation functions (theta/sub L/ = 26 0 , 50 less than E/sub L/ less than 63 MeV) were obtained for strongly excited states below 10 MeV in excitation in the first reaction. For the 12 C + 14 N interaction, a measurement of the angular distributions (25 0 less than theta/sub L/ less than 140 0 , E/sub L/ = 20,25 MeV) for proton, deuteron and alpha-particle emission to many low-lying states sufficed for the present purposes. Comparison of Hauser-Feshbach statistical model calculations with these data indicated that the light-particle production from the 12 C + 14 N interaction as investigated here is predominantly compound nuclear in nature. The selectively strong population of a few states in 32 S by the 28 Si-( 16 O, 12 C) 32 S reaction is primarily direct. The structure of these states was deduced from available light-ion-induced transfer reaction studies and shell model calculations; the importance of shell model configurations is indicated, and an alpha-particle transfer model can not account for the observed selectivity. Calculations of the 28 Si( 16 O, 12 C) 32 S reaction with a microscopic multinucleon transfer code indicate selectivities consistent with the present results. Moreover, the calculations suggest the presence of other, unexpected selectivities, all of which may be understood on a physical basis, and some of which appear as an extension of a similar effect seen in two-nucleon transfer reactions

  19. A study of the collective effects in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Tai, A.

    1995-11-01

    Motivated by both the collective features observed in relativistic heavy ion reactions and the assumption that QCD vacuum might have properties similar to a type II superconductor we investigate in this thesis a few possible models which may work in an intermediate state corresponding to the vortex line states of the type II superconductor. In these models we assume that several strings from a relativistic heavy ion reaction will form a cluster and then the strings inside such a cluster will interact in a collective way. We argue that with an increasing energy density the hadronic phase may not be directly changed into the QGP phase through a phase transition, but will go through the intermediate state first. Whether the intermediate state can change further into a QGP state in which the strings 'melt' up into an extended flux tube may largely depend on the nature of the collective effects exhibited in this state. The investigations are proved quite successful in describing many experimental data including the high P T enhancement, the low P T enhancement, the production of transverse energy in mid-rapidity, the strangeness production and so on. It also brings up a more fundamental question, can we reach the energy density needed for the formation of a QGP state in the accelerator experiments? The collective effects, like Firecracker, Smokering and color rope which we study in this thesis are of the same character, they will all tend to disperse the energy density obtained in the initial encounter of relativistic heavy ion collisions. This dynamical possibility may actually mean that it will become more difficult to reach the second phase transition, i. e. to 'melt' the vacuum into a quark-gluon plasma. 56 refs

  20. 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...

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

    International Nuclear Information System (INIS)

    Back, B.B.

    1986-09-01

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

  2. Transfer products from the reactions of heavy ions with heavy nuclei

    International Nuclear Information System (INIS)

    Thomas, K.E. III.

    1979-11-01

    Production of nuclides heavier than the target from 86 Kr- and 136 Xe-induced reactions with 181 Ta and 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 242 Np or 247 Pu. Estimates were made for the production of 242 Np, 247 Pu, and 248 Am from heavy-ion reactions with uranium targets. Comparisons of reactions of 86 Kr and 136 Xe ions with thick 181 Ta targets and 86 Kr, 136 Xe and 238 U ions with thick 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 248 Cm and 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 86 Kr- and 136 Xe-induced reactions with thin 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

  3. 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.

  4. Design study of an accelerator for heavy ion fusion

    International Nuclear Information System (INIS)

    Katayama, T.; Noda, A.; Tokuda, N.; Hirao, Y.

    1980-01-01

    Design of a demonstration accelerator for heavy ion fusion based on a synchrotron system is briefly described. The proposed complex system of injector linac, rapid cycling synchrotron and five accumulation rings can produce a peak current 1.6 kA, peak power 32 TW and total energy 0.3 MJ. Investigations of the intrabeam scattering give a lifetime of the beam longer than the fusion cycle time of 1 sec

  5. Introduction to the experimental study of hadronic matter in heavy ion collisions. The Quark Gluon Plasma

    International Nuclear Information System (INIS)

    Martinez, G.

    2006-12-01

    In the last 20 years, heavy ion collisions have been an unique way to study the hadronic matter in the laboratory. The phase diagram of hadronic matter remains unknown, although many experimental and theoretical studies have been done in the last decade, aiming at studying its phase transitions. After a general introduction, two phases transition of the hadronic matter, liquid-gas and the transition to the Quark Gluon Plasma, are addressed. A general view about the experimental methods to study these phase transitions is presented in chapter three. The most important results of the heavy ion program in the RHIC collider at BNL (Upton, N.Y., Usa) are presented in chapter four. The last three chapters are devoted to the heavy ion program in the future large hadron collider (LHC) at CERN (Geneva, Switzerland). In particular, the unique LHC experiment specially designed for heavy ion physics, ALICE and its muon spectrometer are presented. (author)

  6. Heavy ions

    CERN Multimedia

    CERN. Geneva; Antinori, Federico

    2001-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  7. Heavy ions

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  8. Study of heavy ion fusion: application to the system 28Si + 28Si

    International Nuclear Information System (INIS)

    Plagnol, E.

    1982-03-01

    Study of the fusion reactions between medium mass range heavy ions (experiments on 56 Ni compound nucleus formed by the reaction 28 Si + 28 Si): - analysis of the properties of the compound nucleus de-excitation process: utilization of the evaporation model based on the Hauser-Fesbach statistical model; study of the evolution of the production cross sections of the evaporation residues as a function of the excitation energy and of the angular momentum; - analysis of the kinetics of the compound nucleus formation, with construction of a model describing the various observed regimes, as a function of energy, in the compound nucleus formation cross section: study of the properties of the rotating liquid drop and of the formation kinetics evolution of the nuclei under Coulomb and nuclear potentials, up to a minimal approach distance, sticking conditions, and development towards scission or equilibrium state (compound nucleus) [fr

  9. First phase plan for experimental study of heavy-ion inertial fusion accelerator

    International Nuclear Information System (INIS)

    Hattori, Toshiyuki; Okamura, Masahiro; Oguri, Yoshiyuki; Aida, Toshihiro; Takeuchi, Kouichi; Sasa, Kimikazu; Itoh, Takashi; Okada, Masashi; Takahashi, Yousuke; Ishii, Yasuyuki.

    1993-01-01

    We propose the basic experiment plan of driver for heavy-ion inertial fusion by heavy-ion linac [1-3] system and the heavy-ion cooler synchrotron. As the first phase of planning, we will improve old heavy-ion accelerator system that accelerate small intensity around Cl ion with charge to mass ratio of 1/4 up to 2.4 MeV/amu. The injector of the system will exchange from the 1.6 MV Peletron Tandem accelerator to an RFQ type linac with an ECR heavy-ion source. According to building up the power sources of RF and focusing magnet, then it is able to accelerate intense around Xe ion with charge to mass ratio of 1/6 up to 2.4 MeV/amu. At the next stage of it, we will construct a heavy-ion cooler synchrotron having magneticrigidity of 3 or 6 Tm and begin to study about HIF driver. (author)

  10. Heavy-ion radiography

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.; Woodruff, K.H.; MacFarland, E.W.

    1983-01-01

    High energy, heavy-ion beams offer superior discrimination of tissue electron densities at very low radiation doses. This characteristic has potential for diagnostic medical imaging of neoplasms arising in the soft tissues and organs because it can detect smaller inhomogeneities than x rays. Heavy-ion imaging may also increase the accuracy of cancer radiotherapy planning involving use of accelerated charged particles. In the current physics research program of passive heavy-ion imaging, critical modulation transfer function tests are being carried out in heavy-ion projection radiography and heavy-ion computerized tomography. The research goal is to improve the heavy-ion imaging method until it reaches the limits of its theoretical resolution defined by range straggling, multiple scattering, and other factors involved in the beam quality characteristics. Clinical uses of the imaging method include the application of heavy-ion computerized tomography to heavy-ion radiotherapy planning, to the study of brain tumors and other structures of the head, and to low-dose heavy-ion projection mammography, particularly for women with dense breasts where other methods of diagnosis fail. The ions used are primarily 300 to 570 MeV/amu carbon and neon ions accelerated at the Lawrence Berkeley Laboratory Bevalac

  11. Beyond mean-field approach to heavy-ion reactions around the Coulomb barrier

    Directory of Open Access Journals (Sweden)

    Ayik Sakir

    2011-10-01

    Full Text Available Dissipation and fluctuations of one-body observables in heavy-ion reactions around the Coulomb barrier are investigated with a microscopic stochastic mean-field approach. By projecting the stochastic meanfield dynamics on a suitable collective path, transport coefficients associated with the relative distance between colliding nuclei and a fragment mass are extracted. Although microscopic mean-field approach is know to underestimate the variance of fragment mass distribution, the description of the variance is much improved by the stochastic mean-field method. While fluctuations are consistent with the empirical (semiclassical analysis of the experimental data, concerning mean values of macroscopic variables the semiclassical description breaks down below the Coulomb barrier.

  12. The Dubna double-arm time-of-flight spectrometer for heavy-ion reaction products

    International Nuclear Information System (INIS)

    Schilling, K.D.; Gippner, P.; Seidel, W.; Stary, F.; Will, E.; Heidel, K.; Lukyanov, S.M.; Penionzhkevich, Yu.E.; Salamatin, V.S.; Sodan, H.; Chubarian, G.G.

    1986-05-01

    The double-arm time-of-flight spectrometer DEMAS designed for the detection and identification of heavy-ion reaction products at incident energies below 10 MeV/amu is presented. Based on the kinematic coincidence method, the relevant physical information is obtained from the measurement of the two correlated velocity vectors of the binary fragments. Construction and performance of the different detector systems applied to measure the time-of-flight values, the position coordinates and the kinetic energies of both fragments are presented in detail. The description of the data acquisition and analysing procedures is followed by the discussion of some experimental examples to demonstrate the spectrometer performance. A mass resolution of typically 4 - 5 amu (fwhm) is routinely achieved. (author)

  13. Fragment formation in GeV-energy proton and light heavy-ion induced reactions

    International Nuclear Information System (INIS)

    Murakami, T.; Haga, M.; Haseno, M.

    2002-01-01

    We have investigated similarities and differences among the fragment formation processes in GeV-energy light-ion and light heavy-ion induced reactions. We have newly measured inclusive and exclusive energy spectra of intermediate mass fragments (3 ≤ Z ≤ 30; IMFs) for 8-GeV 16 O and 20 Ne and 12-GeV 20 Ne induced target multifragmentations (TMFs) in order to compare them with those previously measured for 8- and 12-GeV proton induced TMFs. We fond noticeable difference in their spectrum shapes and magnitudes but all of them clearly indicate the existence of sideward-peaked components, indicating fragment formations are mainly dictated not by a incident energy per nucleon but by a total energy of the projectile. (author)

  14. Dependence of compound nucleus formation probability on K equilibration time in heavy-ion reactions

    International Nuclear Information System (INIS)

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

    2014-01-01

    In the present work, we have carried out the analysis of fragment anisotropy data of various systems selected for cases Z 1 Z 2 < 1600 and Z CN < 96 so that both QF and FF are absent and the anomalous anisotropies are only due to PEF. It may also be noted that in such cases J cr (the J above which the fusion pocket vanishes) is less than J Bf = 0 (the J at which the liquid drop fission barrier vanishes) so that all J's will be contributing to PEF as well. According to PEF model, the observed angular anisotropy of fission fragments in heavy-ion induced reactions can be written as an admixture of two components: the anisotropy from compound nucleus fission (CN) and anisotropy due to non-compound nucleus fission (NCN)

  15. Catapult mechanism for fast particle emission in fission and heavy ion reactions

    International Nuclear Information System (INIS)

    Maedler, P.

    1984-01-01

    The fission processes of slabs of nuclear matter is modelled in the Hartree-Fock time dependence approximation by adding an initial collective velocity field to the static self-consistent solution. In dependence on its amplitude either large amplitude density oscillations are excited or fission occurs. The final disintegration of the slab proceeds on a time scale 10 -22 s and is characterized by a sharp peak in the actual velocity field in the region of the ''snatching'' inner low density tails. A characteristic time later a low density lump correlated with a peak in the velocity field energies in front of the fragments. These particles are called ''catapult particles''. Recent experimental results possibly provide evidence for catapult neutrons in low-energy fission. The significance of the catapult mechanism for fast particle emission in the exit channel of heavy ion reactions is discussed

  16. Proceedings of the 2nd joint seminar on atomic collisions and heavy ion induced nuclear reactions

    International Nuclear Information System (INIS)

    Harada, Kichinosuke; Ozawa, Kunio; Kamitsubo, H.; Nomura, T.; Awaya, Y.; Watanabe, T.

    1982-11-01

    The meeting of the 2nd joint seminar on atomic collisions and heavy ion induced nuclear reactions was held at the University of Tokyo, May 13 and 14, 1982. The aim of this seminar has been not only to recognize the common problems lying between above two research fields, but also to obtain an overview of the theoretical and experimental approaches to clear the current problems. In the seminar, more than 50 participants gathered and presented 16 papers. These are two general reviews and fourteen comprehensive surveys on topical subjects which have been developed very intensively in recent years. The editors would like to thank all participants for their assistance and cooperation in making possible a publication of these proceedings. (author)

  17. An experimental approach to angular momentum transfer in heavy ion reactions

    International Nuclear Information System (INIS)

    Babinet, R.

    1980-01-01

    The current experimental status on angular momentum transfer status in heavy ion reactions is reviewed. After a short presentation of the basic theoretical concepts that are underlying all the research works in this field, the experimental techniques that have been commonly used are presented. Results obtained by the γ-multiplicity method are discussed first. Then come, for the very heavy systems, the sequential fission data, followed by the results of a recent experiment on light charged particles. The simple theoretical concepts that are introduced first are continuously used as guidelines to discuss the following results. The respective advantages but also the basic limitations of the above three experimental techniques are exposed. Although they are expected to work best in different regions of the mass table, it is shown, that they give complementary informations which have been most useful in improving our understanding of the tangential friction mechanism

  18. Role of hexadecapole deformation of projectile 28Si in heavy-ion fusion reactions near the Coulomb barrier

    Science.gov (United States)

    Kaur, Gurpreet; Hagino, K.; Rowley, N.

    2018-06-01

    The vast knowledge regarding the strong influence of quadrupole deformation β2 of colliding nuclei in heavy-ion sub-barrier fusion reactions inspires a desire to quest the sensitivity of fusion dynamics to higher order deformations, such as β4 and β6 deformations. However, such studies have rarely been carried out, especially for deformation of projectile nuclei. In this article, we investigated the role of β4 of the projectile nucleus in the fusion of the 28Si+92Zr system. We demonstrated that the fusion barrier distribution is sensitive to the sign and value of the β4 parameter of the projectile, 28Si, and confirmed that the 28Si nucleus has a large positive β4. This study opens an indirect way to estimate deformation parameters of radioactive nuclei using fusion reactions, which is otherwise difficult because of experimental constraints.

  19. Non-equilibrium statistical mechanical approach for describing heavy ion reactions

    International Nuclear Information System (INIS)

    Sventek, J.S.

    1979-01-01

    With the availability of heavy-ion projectiles (A > 4) at low to intermediate energies (4 < E/A < 10), products showing various stages of relaxation for certain macroscopic variables (center-of-mass energy, orbital angular momentum, etc.) were produced in various reactions. The distributions for these macroscopic variables showed a correlation between the stage of relaxation reached and the net amount of mass transfer which had occurred in the reaction. There was also evidence that there was an asymmetry in the number of net transfers necessary for complete relaxation between stripping ad pickup reactions. A model for describing the time-evolution of these reactions has been formulated, the keystone of which is a master-equation approach for describing the time-dependence of the mass-asymmetry. This, coupled with deterministic equations of motion for the other macroscopic coordinates in the reaction lead to calculated distributions which provide an excellent qualitative description of these reactions, and, in some cases, quantitatively reproduce the experimental data quite well

  20. Study of excitation energy sharing in heavy ion collisions as a function of their inelasticity

    International Nuclear Information System (INIS)

    Lott, B.

    1986-01-01

    The excitation energy sharing between the fragments of a heavy ion collision has been studied for quasi-elastic and deep inelastic mechanisms. A 32 S beam of 232 MeV incident energy has been used to bombard several targets (S, 58 Ni, 93 Nb). The evaporated charged particle multiplicities have been measured by inclusive measurements of the projectile-like nuclei and exclusive measurements of the two final nuclei. Evaporation calculations using the Hauser-Feshbach formalism allows us to deduce from the multiplicity measurements the projectile-like excitation energy. These results are compatible with the assumption of an equal sharing of excitation energies for quasi-elastic reaction products, and with the assumption of a mass ratio sharing for fully relaxed reaction products. Limiting values for the relaxation time of this mode have been deduced and are in agreement with predictions from the model developed by Randrup [fr

  1. Origin of transverse momentum in relativistic heavy-ion collisions: Microscopic study

    International Nuclear Information System (INIS)

    Blaettel, B.; Koch, V.; Lang, A.; Weber, K.; Cassing, W.; Mosel, U.

    1991-01-01

    We study the origin of the transverse momentum distribution in heavy-ion collisions within a relativistic transport approach. To achieve a better understanding of the reaction dynamics, we decompose the total p t distribution into a mean-field, N-N collision, and Fermi-momentum part. We find that the origin of the transverse momentum strongly depends on the rapidity region. Our investigation of the impact-parameter and mass dependence suggests that peripheral collisions may be useful to investigate the momentum dependence of the mean-field in the nucleus-nucleus case, whereas the mass dependence could give hints about the N-N-collision part. Only after these two issues are settled it may be possible to extract information about the density dependence in central collisions, which may, however, necessitate reactions at even higher energies than the 800 MeV/nucleon considered in this work

  2. Pauli-blocking effect in two-body collisions dominates the in-medium effects in heavy-ion reactions near Fermi energy

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Yong-Zhong, E-mail: yzxing@tsnu.edu.cn [Institute for the Fundamental Physics, Tianshui Normal University, Gansu, Tianshui 741000 (China); Zhang, H.F. [Institute for the Fundamental Physics, Tianshui Normal University, Gansu, Tianshui 741000 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Liu, Xiao-Bin [Institute for the Fundamental Physics, Tianshui Normal University, Gansu, Tianshui 741000 (China); Zheng, Yu-Ming [Institute for the Fundamental Physics, Tianshui Normal University, Gansu, Tianshui 741000 (China); China Institute of Atomic Energy, P.O. Box 275(18), Beijing 102413 (China)

    2017-01-15

    The dissipation phenomenon in the heavy-ion reaction at incident energy near Fermi energy is studied by simulating the reactions {sup 129}Xe + {sup 129}Sn and {sup 58}Ni + {sup 58}Ni with isospin-dependent quantum molecular dynamics model (IQMD). The isotropy ratio in terms of transverse and longitudinal energies of the free protons emitted in the final states of these reactions is quantitatively analyzed to explore the in-medium correlation of the binary collisions. Comparison of the calculations with the experimental data recently released by INDRA collaboration exhibits that the ratio is very sensitive to the Pauli blocking effect in two-body collisions and Pauli exclusion principle is indispensable in the theoretical simulations for the heavy-ion reactions near the Fermi energy.

  3. Studies in High Energy Heavy Ion Nuclear Physics

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Gerald W. [Univ. of Texas, Austin, TX (United States); Markert, Christina [Univ. of Texas, Austin, TX (United States)

    2016-09-01

    This close-out report covers the period 1994 - 2015 for DOE grant DE-FG02-94ER40845 with the University of Texas at Austin. The research was concerned with studies of the strong nuclear force and properties of nuclear matter under extreme conditions of temperature and density which far exceed that in atomic nuclei. Such extreme conditions are briefly created (for about 10 trillionths of a trillionth of a second) during head-on collisions of large atomic nuclei (e.g. gold) colliding at speeds very close to the speed-of-light. The collisions produce thousands of subatomic particles, many of which are detected in our experiment called STAR at the Relativistic Heavy-Ion Collider at the Brookhaven National Lab in New York. The goal of our research is to learn how the strong nuclear force and its fundamental particles (quarks and gluons) behave in extreme conditions similar to that of the early Universe when it was about 1 micro-second old, and in the cores of very dense neutron stars. To learn anything new about the matter which exists for such a very short amount of time requires carefully designed probes. In our research we focused on two such probes, one being short-lived resonance particles and the other using correlations between pairs of the detected particles. Resonances are short-lived particles created in the collision, which interact with the surrounding matter, and which break apart, or "decay" into more stable particles which survive long enough to be seen in our detectors. The dependence of resonance properties on the conditions in the collision system permit tests of theoretical models and improve our understanding. Dynamical interactions in the matter also leave imprints on the final, outgoing particle distributions measured in the experiment. In particular, angular correlations between pairs of particles can be related to the fundamental strong force as it behaves in the hot, dense matter. Studying correlations as a function of experimentally controlled

  4. Studies in High Energy Heavy Ion Nuclear Physics

    International Nuclear Information System (INIS)

    Hoffmann, Gerald W.; Markert, Christina

    2016-01-01

    This close-out report covers the period 1994 - 2015 for DOE grant DE-FG02-94ER40845 with the University of Texas at Austin. The research was concerned with studies of the strong nuclear force and properties of nuclear matter under extreme conditions of temperature and density which far exceed that in atomic nuclei. Such extreme conditions are briefly created (for about 10 trillionths of a trillionth of a second) during head-on collisions of large atomic nuclei (e.g. gold) colliding at speeds very close to the speed-of-light. The collisions produce thousands of subatomic particles, many of which are detected in our experiment called STAR at the Relativistic Heavy-Ion Collider at the Brookhaven National Lab in New York. The goal of our research is to learn how the strong nuclear force and its fundamental particles (quarks and gluons) behave in extreme conditions similar to that of the early Universe when it was about 1 micro-second old, and in the cores of very dense neutron stars. To learn anything new about the matter which exists for such a very short amount of time requires carefully designed probes. In our research we focused on two such probes, one being short-lived resonance particles and the other using correlations between pairs of the detected particles. Resonances are short-lived particles created in the collision, which interact with the surrounding matter, and which break apart, or 'decay' into more stable particles which survive long enough to be seen in our detectors. The dependence of resonance properties on the conditions in the collision system permit tests of theoretical models and improve our understanding. Dynamical interactions in the matter also leave imprints on the final, outgoing particle distributions measured in the experiment. In particular, angular correlations between pairs of particles can be related to the fundamental strong force as it behaves in the hot, dense matter. Studying correlations as a function of experimentally controlled

  5. Origin of a maximum of the astrophysical S factor in heavy-ion fusion reactions at deep subbarrier energies

    Science.gov (United States)

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

    2018-03-01

    The hindrance phenomenon of heavy-ion fusion cross sections at deep subbarrier energies often accompanies a maximum of an astrophysical S factor at a threshold energy for fusion hindrance. We argue that this phenomenon can naturally be explained when the fusion excitation function is fitted with two potentials, with a larger (smaller) logarithmic slope at energies lower (higher) than the threshold energy. This analysis clearly suggests that the astrophysical S factor provides a convenient tool to analyze the deep subbarrier hindrance phenomenon, even though the S factor may have a strong energy dependence for heavy-ion systems unlike that for astrophysical reactions.

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

    International Nuclear Information System (INIS)

    Celata, C.M.

    2004-01-01

    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 ∼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

  7. Heavy ion fusion

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1986-01-01

    This report on the International Symposium on Heavy Ion Fusion held May 27-29, 1986 summarizes the problems and achievements in the areas of targets, accelerators, focussing, reactor studies, and system studies. The symposium participants recognize that there are large uncertainties in Heavy Ion Fusion but many of them are also optimistic that HIF may ultimately be the best approach to fusion

  8. Beam dynamics studies of the Heavy Ion Fusion Accelerator injector

    International Nuclear Information System (INIS)

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

    1995-04-01

    A driver-scale injector for the Heavy Ion Fusion Accelerator project has been built at LBL. This machine has exceeded the design goals of high voltage (> 2 MV), high current (> 0.8 A of K + ) and low normalized emittance (< 1 π mm-mr). The injector consists of a 750 keV diode pre-injector followed by an electrostatic quadrupole accelerator (ESQ) which provides strong (alternating gradient) focusing for the space-charge dominated beam and simultaneously accelerates the ions to 2 MeV. The fully 3-D PIC code WARP together with EGUN and POISSON were used to design the machine and analyze measurements of voltage, current and phase space distributions. A comparison between beam dynamics characteristics as measured for the injector and corresponding computer calculations will be presented

  9. Heavy ion microbeam system for study of single event effects

    International Nuclear Information System (INIS)

    Kamiya, Tomihiro; Utsunomiya, Nobuhiro; Minehara, Eiichi; Tanaka, Ryuichi; Ohmura, Miyoshi; Kohno, Kazuhiro; Iwamoto, Eiji.

    1992-01-01

    A high-energy heavy ion microbeam system has been developed and installed on a beam line of a 3 MV tandem electrostatic accelerator mainly for analysis of basic mechanism of single event upset (SEU) of semiconductor devices in spacecraft. The SEU is now the most serious problem for highly reliable spacecraft electronics system with long space mission. However, the mechanism has not been understood on the basis of microscopic process of SEU. The SEU phenomena depends not only upon hitting particles, but also upon the hit position on the microcircuit. To observe the transient charge pulse from a SEU, a single ion particle must hit exactly the desired position of the microcircuit. Such an experiment requires the microbeam spot size within 1 μm, the beam positioning accuracy within ±1 μm, and single ion hitting. The microbeam system has been designed to meet the above technical requirements. The system is equipped with two lens systems: one to control the target beam current in a wide range down to extremely low current without any change of the beam optics, and the other to focus heavy ion beams within a spot size of 1 μm. The final goal is to hit a microscopic target area with a single 15 MeV nickel ion. The beam spot size has been evaluated by Gaussian fitting of secondary electron profiles with microbeam scanning across the fine Cu mesh. The single ion detection has been also tested to generate a trigger signal for closing beam shutter to prevent further hits. This paper outlines the new microbeam system and describes methods to realize these techniques. (author)

  10. Localization effects in heavy ion collisions

    International Nuclear Information System (INIS)

    Donangelo, R.J.

    1984-01-01

    Radial and angular localization in heavy ion reactions on deformed nuclei is discussed. A theoretical method appropriate to study these localization effects is briefly described and then applied to the determination of deformed heavy ion potentials from inclastic scattering data. It is argued that one-and two-nucleon transfer reactions on deformed nuclei can provide a probe of nuclear structure in high angular momentum states and be at least qualitatively analyzed in the light of these localization concepts. (Author) [pt

  11. Central collisions of heavy ions

    International Nuclear Information System (INIS)

    Fung, Sun-yiu.

    1991-10-01

    This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1990 to September 30, 1991. During this period, our program focuses on particle production at AGS energies, and correlation studies at the Bevalac in nucleus central collisions. We participated in the preparation of letters of intent for two RHIC experiments -- the OASIS proposal and the Di-Muon proposal -- and worked on two RHIC R ampersand D efforts -- a silicon strip detector project and a muon-identifier project. A small fraction of time was also devoted to physics programs outside the realm of heavy ion reactions by several individuals

  12. Classical molecular dynamics simulation of weakly-bound projectile heavy-ion reactions

    Directory of Open Access Journals (Sweden)

    Morker Mitul R.

    2015-01-01

    Full Text Available A 3-body classical molecular dynamics approach for heavy-ion reactions involving weakly bound projectiles is developed. In this approach a weakly bound projectile is constructed as a two-body cluster of the constituent tightly bound nuclei in a configuration corresponding to the observed breakup energy. This 3-body system with their individual nucleon configuration in their ground state is dynamically evolved for given initial conditions using the three-stage classical molecular dynamics approach (3S-CMD. Various levels of rigidbody constraints on the projectile constituents and the target are considered at appropriate stages. This 3-dimensional approach explicitly takes into account not only the long range Coulomb reorientation of the deformed collision partner but internal excitations and breakup probabilities at distances close to the barrier also. Dynamical simulations of 6Li+209Bi show all the possible reaction mechanism like complete fusion, incomplete fusion, scattering and breakup scattering. Complete fusion cross sections of 6Li+209Bi and 7Li+209Bi reactions are calculated in this approach with systematic relaxations of the rigid-body constraints on one or more constituent nuclei.

  13. Semi-classical approaches for the proton emission in intermediate energy heavy ion reactions

    International Nuclear Information System (INIS)

    Gregoire, C.; Scheuter, F.; Remaud, B.; Sebille, F.

    1984-05-01

    Semi-classical approaches are proposed to study the transition between the one- and two-body processes in intermediate energy heavy ion collisions. The Landau-Vlasov equation is used as a transport equation for nucleons in the nuclear matter. We apply our formalism to the fast proton ejection. On the one hand, the effects of the nucleon-nucleon collisions are studied for the particles which travel through the nucleus cores. On the other hand, the inertial emission turns out to be an important proton emission mechanism. Our results conflict the interpretation of the proton spectra in terms of moving sources. Reasonable agreements with the experimental data are found without reference to any thermal equilibrium

  14. 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

  15. Heavy ions reactions at GANIL energies: the use of LISE telescopic mode for the small angle measurements

    International Nuclear Information System (INIS)

    Bacri, C.O.

    1989-01-01

    The use of heavy ions at GANIL energies leads to a concentration of the reaction products in the forward direction. Measurements have to be performed at and around 0 degree and with an accuracy around one milliradian. The angular selection (after the two dipoles) is performed after a magnetic rigidity one (between the two dipoles). The double sorting does allow measurements close to the beam in magnetic rigidity and in angle. TRANSPORT calculations show that the LISE spectrometer of GANIL can be used in telescopic mode. Experiments with a 44 MeV per nucleon Argon beam on C, Al, Ni and Au targets are performed. The identification of all the detected ions allowed the obtention of angular distributions at and around 0 degree with the required accuracy. This study is completed by a theoretical approach of the thermodynamical evolution based on an extended quantal mean field theory in which a collision-like term simulates residual interaction effects [fr

  16. A possible mechanism in heavy ion induced reactions: 'fast fission process'

    International Nuclear Information System (INIS)

    Borderie, B.; Gardes, D.; Berlanger, M.

    1980-01-01

    The influence of the orbital angular momentum l on the mass distribution of fission fragments is studied, both on previously available data on heavy ion induced fission and in new specifically planned experiments: systems 40 Ar + 165 Ho and 24 Mg + 181 Ta at bombarding energies ranging from 180 up to 391 MeV and leading to the same fissionning nucleus 205 At wigh different l distributions. When l values corresponding to a vanished fission barrier are reached, the mass distribution broadens. This suggest the existence of a specific process, 'fast fission', at l-values leading to compound nucleus formation and deep inelastic collisions, respectively. This process and its conditions of occurrence are discussed; of special interest are the correlated differences between the limitations to the fission cross-section and the fission mass distributions broadenings, respectively, for the Ar + Ho and Mg + Ta systems

  17. Study of resonances produced in Heavy Ion Collisions

    Science.gov (United States)

    Quattrocchi, L.; Acosta, L.; Auditore, L.; Cardella, G.; Chbihi, A.; De Filippo, E.; Favela, F.; Gnoffo, B.; Lanzalone, G.; Martel, I.; Martorana, N. S.; Pagano, A.; Pagano, E. V.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Rizzo, F.; Russotto, P.; Trifirò, A.; Trimarchi, M.; Verde, G.; Veselsky, M.

    2018-05-01

    At Laboratori Nazionali del Sud of Catania an experiment has been carried out in order to investigate the correlations between particles produced in 12C+24Mg reaction at 35 AMeV incident energy. Two α correlation has been explored because provide information about temperature of 8Be nuclei produced in the reaction, while three α correaltion has been studied in order to evaluate the competition between sequential and direct decay mode of resonances produced in 12C quasi-projectiles.

  18. 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.)

  19. Chemical equilibrium relations used in the fireball model of relativistic heavy ion reactions

    International Nuclear Information System (INIS)

    Gupta, S.D.

    1978-01-01

    The fireball model of relativistic heavy-ion collision uses chemical equilibrium relations to predict cross sections for particle and composite productions. These relations are examined in a canonical ensemble model where chemical equilibrium is not explicitly invoked

  20. Study of multiple scattering effects in heavy ion RBS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Z; O` Connor, D J [Newcastle Univ., NSW (Australia). Dept. of Physics

    1997-12-31

    Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

  1. Study of multiple scattering effects in heavy ion RBS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Z.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics

    1996-12-31

    Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

  2. Excitation functions for quasielastic transfer reactions induced with heavy ions in bismuth

    International Nuclear Information System (INIS)

    Gardes, D.; Bimbot, R.; Maison, J.; de Reilhac, L.; Rivet, M.F.; Fleury, A.; Hubert, F.; Llabador, Y.

    1978-01-01

    The excitation functions for the production of 210 Bi, 210 Po, /sup 207-211/At, and 211 Rn through quasielastic transfer reactions induced with heavy ions in 209 Bi have been measured. The corresponding reactions involved the transfer of one neutron, one proton, two charges, and three charges from projectile to target. The projectiles used were 12 C, 14 N, 16 O, 19 F, 20 Ne, 40 Ar, 40 Ca, 56 Fe, and 63 Cu. The experimental techniques involved target irradiations and off-line α and γ activity measurements. Chemical separations were used to solve specific problems. Careful measuremnts of incident energies and cross sections were performed close to the reaction thresholds. All excitation functions exhibit the typical features of quasielastic transfer reactions: a sharp increase at low energy, and a constant value at high incident energy. The position of the thresholds are strongly influenced by the energetics of the reaction: High cross sections are observed under the strong interaction barrier if the energy balance at the minimum distance of approach is positive. This balance is equal to the difference between the interaction potentials in the entrance and exit channels, corrected for the mass balance. The constant cross sections observed for the high energy part of a given excitation function are consistent with the assumption that the curve P (R) which represents the transfer probability versus the distance between the nucleus centers does not vary with incident energy. This assumption implies the constancy of the optimum distance of approach R/sub opt/, of the R window ΔR for which P (R) is significant, and of the magnitude of P (R). Moreover the data show that the high energy cross sections for one-proton transfer are independent of the projectile, while odd-even effects of the projectile atomic number Z on the two-charge transfer cross sections are observed for the lightest incident ions 14 N to 20 Ne

  3. Studies on advantages of heavy ions in radiotherapy compared with γ-rays

    International Nuclear Information System (INIS)

    Guo Chuanling; Wang Jufang; Jin Xiaodong; Jing Xigang; Li Renmin; Wei Wei; Li Wenjian

    2007-01-01

    Hepatoma and melanoma cells were exposed to 12 C 6+ beams generated by HIRFL facility and γ-rays and the cell response was studied by colony assays as well as the analysis of RBE of carbon ions was evolved. The survival curves of cells irradiated by heavy ions were different from those of cells irradiated by γ-rays. And two kinds of cell showed the obvious discrepancy in response to the photon and ion irradiation. The results showed that heavy ions have special physical properties and mighty potency to kill cell in both single and fractional irradiation meanwhile it can kill tumor cells with high radioresistance more efficiently. When involved in clinical therapy, heavy ions will enhance the therapy efficiency and decrease the suffering of patients because it can impair the repair for sublethal damage of cells which can lead to fewer irradiation fractions

  4. Preliminary study on mutagenic effects of heavy ions irradiation on maize inbred lines

    International Nuclear Information System (INIS)

    Yu Lixia; Li Wenjian; Xie Hongmei; Chen Xuejun; Chen Jing

    2010-01-01

    In order to study mutagenic effects of different heavy ions irradiation on maize inbred lines,corn seeds of Zheng58, Lu9801, Jinxiang4C-1, CSR24001, 308 and 478 were irradiated with 12 C 6+ and 36 Ar 18+ ions. The experimental results showed that the germination rate and planting percent were different after irradiation. The wettish seeds had higher sensibility to heavy ion irradiation. The leaf type of the plant appeared visible changes in M 1 generation. In M 2 generation, great changes had taken place in economic traits, many of which are beneficial mutation. Some beneficia1 mutation could be stably inherited in M 3 generation. From the above, it can be predicted that heavy ions irradiation is an effective means of genetic improvement of maize. (authors)

  5. Preliminary Study on 50MHz Heavy Ion RFQ without Pre-Bunchers

    International Nuclear Information System (INIS)

    Cho, Yong Sub; Jang, Ji Ho; Kim, Han Sung; Kwon, Hyeok Jung

    2009-01-01

    We are studying a Radio Frequency Quadrupole (RFQ) as a lower energy part for a 200-MeV/u heavy ion linear accelerator of the International Business and Science Belt Project. The RFQ accelerates the 10- keV/u heavy ion beams from ion source (hydrogen molecules to uranium) and injects the 300-keV/u beam to the superconducting linac. Table I shows the basic parameters for the RFQ accelerator. In this study, we assumed that pre-bunchers to accelerate two charge state is not required

  6. Two-body molecular model for resonances in heavy ion reactions

    International Nuclear Information System (INIS)

    Abe, Y.

    1978-01-01

    It is necessary to develop qualitative arguments on resonance mechanisms, which will give an overview on occurrences of resonances in heavy ion reactions, and further to identify typical examples of nuclear molecules among existing experimental data. In section 2, qualitative arguments on resonance mechanisms are given by exemplifying the 12 C + 16 O system with the 3 - excitation of the 16 O nucleus. In section 3 a simple formulation in the coupled channel framework is given. Resonances in the 12 C - 16 O system, which has been observed well above the Coulomb barrier, are investigated in section 4. In section 5 an old, but not yet solved problem on resonances in the 12 C + 12 C system which have been observed at sub-Coulomb energies, is taken up along the nuclear molecular picture. Further discussions are given on a role of the 20 Ne-α channel along the present simple qualitative picture given in section 2, which can be extended to rearrangement channels. (Auth.)

  7. Micropolyelectrons as possible sources of the anomalous positron peaks in heavy-ion reactions

    International Nuclear Information System (INIS)

    Wong, Cheuk-Yin.

    1988-01-01

    We propose that aggregates of electrons and positrons in a small assembly [micropolyelectrons (e + e - ) n ], held together by their own electromagnetic interactions, are probably the sources of the anomalous positron peaks observed in heavy-ion reactions. The quasistability of the micropolyelectrons arises from a strong noncentral, short-range, attractive interaction between an electron and a positron in their 0 ++ state, which may be supercritical and may lead to a condensation of such pairs. These entities are strongly attracted to a nucleus with a large charge, due to the quadratic Coulomb interaction between the nucleus and the constituents, and may therefore have binding energies greater than their rest masses to render them spontaneously produced in a strong Coulomb field. Final-state interactions between the produced micropolyelectrons and the receding nuclei may lead to their being nearly at rest and back-to-back decay into e + and e - in some cases, and their being captured into stationary orbits and asymmetrical decay in some other cases

  8. Description of heavy-ion fusion in terms of direct reaction theory

    International Nuclear Information System (INIS)

    Hong, S.W.

    1987-01-01

    A direct reaction description of the heavy-ion fusion, proposed by Udagawa, Kim and Tamura, has been successfully used in calculating the fusion cross sections and the spin distributions for a number of systems in the energy regions from the sub-barrier to the above-barrier region. A fusion potential is introduced in this theory and the radius of the fusion potential is treated as an adjustable parameter. The theory is thus a one-parameter theory. The results obtained by Udagawa, Kim and Tamura showed that the radius parameter ranges from 1.4 to 1.5 fm, which is much larger than the radius (1.0 fm) used in other models. A hard evidence is shown to demonstrate the necessity of the long-ranged fusion potential radius in the near-barrier region. In the above-barrier region, the use of the energy-dependent optical potential and the energy-dependent fusion potential radius is proved to be essential in reproducing the measured fusion cross sections. As a further application of the theory, the double folded potential model is utilized to provide the real part of the optical potential. The imaginary part of the optical potential is determined so that not only the elastic scattering but also the fusion cross sections can be reproduced

  9. Proceedings of the workshop on microscopic and phenomenological studies of the interactions between light-heavy ions

    International Nuclear Information System (INIS)

    Yamaguchi, S.

    1993-01-01

    The workshop 'Microscopic and Phenomenological Studies of the Interactions between Light-Heavy Ions' was held at Institute for Nuclear Study, University of Tokyo from Dec. 24 to Dec. 26, 1991. The workshop included 1) studies of the nucleus-nucleus interactions of the systems as 16 O- 16 O, 16 O- 15 N, etc., or the studies of the elastic and inelastic scatterings and the transfer reactions in such systems, 2) structure and reactions of neutron-rich nuclei, 3) microscopic derivation of the effective two-nucleon interactions, 4) development of the methods of techniques applied to the heavier systems. (author)

  10. Evolution of direct mechanisms with incident energy from the Coulomb-barrier to relativistic energies. - Two-center effects in nucleon transfer between nuclei. - Signatures of nucleon promotion in heavy ion reactions at barrier energies

    International Nuclear Information System (INIS)

    Oertzen, W. von; Voit, H.; Imanishi, B.

    1988-10-01

    This report contains a review article considering the evolution of direct mechanisms with incident energy in heavy ion reactions and two theoretical articles concerning two-center effects in transfer reactions between heavy ions and the nucleon promotion in heavy ion reactions. See hints under the relevant topics. (HSI)

  11. Use of heavy ion accelerators in fusion reactor-related radiation-damage studies

    International Nuclear Information System (INIS)

    Taylor, A.; Dobson, D.A.

    1974-01-01

    The heavy-ion accelerator has become an important tool in the study of the fundamentals of radiation damage in fission- and fusion-reactor materials. Present facilities for such studies within the Materials Science Division at Argonne National Laboratory are provided by two complementary accelerator systems. Examples of the work carried out are discussed

  12. Studies of Limits on Uncontrolled Heavy Ion Beam Losses for Allowing Hands-On Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Reginald M. Ronningen; Igor Remec

    2010-09-11

    Dose rates from accelerator components activated by 1 W/m beam losses are obtained semiempirically for a 1 GeV proton beam and by use of Monte Carlo transport codes for the proton beam and for 777 MeV/u 3He, 500 MeV/u 48Ca, 86Kr, 136Xe, and 400 MeV/u 238U ions. The dose rate obtained by the semi-empirical method, 0.99 mSv/h (99 mrem/h) at 30 cm, 4 h after 100 d irradiation by a 1-GeV proton beam, is consistent with studies at several accelerator facilities and with adopted hands-on maintenance dose rate limits. Monte Carlo simulations verify this result for protons and extend studies to heavy ion beam losses in drift-tube linac and superconducting linac accelerating structures. The studies indicate that the 1 W/m limit imposed on uncontrolled beam losses for high-energy proton beams might be relaxed for heavy ion beams. These studies further suggest that using the ratio of neutrons produced by a heavy ion beam to neutrons produced by a proton beam along with the dose rate from the proton beam (for thin-target scenarios) should allow an estimate of the dose rates expected from heavy ion beam losses.

  13. Study of the effect of heavy ion energy on the sensitivity of electronic devices

    International Nuclear Information System (INIS)

    Raine, M.

    2011-01-01

    This thesis studies the sensitivity of advanced electronic devices in radiative environments. The work deals with the detailed modeling of the deposited energy induced by heavy-ion in matter, and the influence of taking it into account in the tools simulating the response of irradiated devices. To do so, a simulation chain was developed, combining different calculation codes at various scales. In a first step, the particle-matter interaction code Geant4 is used to model the heavy ion track. These tracks are then implemented in a TCAD simulator, in order to study the response of elementary transistors to these detailed energy deposits. This step is completed with experimental measurements. Finally, the study is extended to the circuit level, by interfacing the heavy ion tracks with a SEE prediction tool. These different steps evidence the need for taking into account the radial extension of the ion track to all simulation levels, to adequately model the response of advanced devices under heavy ion irradiations. (author) [fr

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

    International Nuclear Information System (INIS)

    Patin, Joshua B.

    2002-01-01

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

  15. Analysis of multi-fragmentation reactions induced by relativistic heavy ions using the statistical multi-fragmentation model

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, T., E-mail: ogawa.tatsuhiko@jaea.go.jp [Research Group for Radiation Protection, Division of Environment and Radiation Sciences, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan); Sato, T.; Hashimoto, S. [Research Group for Radiation Protection, Division of Environment and Radiation Sciences, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan); Niita, K. [Research Organization for Information Science and Technology, Shirakata-shirane, Tokai, Ibaraki 319-1188 (Japan)

    2013-09-21

    The fragmentation cross-sections of relativistic energy nucleus–nucleus collisions were analyzed using the statistical multi-fragmentation model (SMM) incorporated with the Monte-Carlo radiation transport simulation code particle and heavy ion transport code system (PHITS). Comparison with the literature data showed that PHITS-SMM reproduces fragmentation cross-sections of heavy nuclei at relativistic energies better than the original PHITS by up to two orders of magnitude. It was also found that SMM does not degrade the neutron production cross-sections in heavy ion collisions or the fragmentation cross-sections of light nuclei, for which SMM has not been benchmarked. Therefore, SMM is a robust model that can supplement conventional nucleus–nucleus reaction models, enabling more accurate prediction of fragmentation cross-sections.

  16. Analysis of multi-fragmentation reactions induced by relativistic heavy ions using the statistical multi-fragmentation model

    International Nuclear Information System (INIS)

    Ogawa, T.; Sato, T.; Hashimoto, S.; Niita, K.

    2013-01-01

    The fragmentation cross-sections of relativistic energy nucleus–nucleus collisions were analyzed using the statistical multi-fragmentation model (SMM) incorporated with the Monte-Carlo radiation transport simulation code particle and heavy ion transport code system (PHITS). Comparison with the literature data showed that PHITS-SMM reproduces fragmentation cross-sections of heavy nuclei at relativistic energies better than the original PHITS by up to two orders of magnitude. It was also found that SMM does not degrade the neutron production cross-sections in heavy ion collisions or the fragmentation cross-sections of light nuclei, for which SMM has not been benchmarked. Therefore, SMM is a robust model that can supplement conventional nucleus–nucleus reaction models, enabling more accurate prediction of fragmentation cross-sections

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

    International Nuclear Information System (INIS)

    Wieman, H.H.

    1994-05-01

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

  18. On the study of fragments from heavy ion collisions

    International Nuclear Information System (INIS)

    Nolte, H.M.

    1989-06-01

    In order to study the mechanism of nucleus nucleus collisions, a dedicated apparaturs was built. The detectors have large solid angles (17 msr each), and are therefore good tools for coincidence measurements. Also time of flight measurements were possible. The developed ionization chamber showed a good charge resolution up to Z ≅ 20. With this new developed apparatus coincidence measurements with a relative large solid angle of 27 msr and time of flight measurements for mass determination were performed. The following reactions were studied (E 0 = 1012.4 MeV): Inclusive measurements: A( 32 S,f)X with A = 51 V, 109 Ag, 197 Au and 238 U. The angles θ lab (f) were: +17 0 , -35 0 , +53 0 , -71 0 , +89 0 and -107 0 . Coincidence measurements: A( 32 S;f 1 ,f 2 )X with A = 109 Ag and 197 Au, with θ(f 1 ) = 17 0 and θ(f 2 ) = -35 0 . The fragments were separated with respect to their charge number up to Z = 16. The ejectile mass was determined with the time of flight measurements at 17 0 . (orig./HSI) [de

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

    Energy Technology Data Exchange (ETDEWEB)

    Leyba, J.D.

    1990-09-07

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

  20. Studying heavy-ion collisions with coverage near zero degrees using FAUST–QTS

    International Nuclear Information System (INIS)

    Cammarata, Paul; Chapman, Matthew B.; McIntosh, Alan B.; Souliotis, George A.; Bakhtiari, Layla; Behling, Spencer; Bonasera, Giacomo; Heilborn, Lauren A.; Mabiala, Justin; May, Larry W.; Raphelt, Andrew; Youngs, Michael D.

    2015-01-01

    Heavy-ion collisions around the Fermi energy provide a rich environment for investigating reaction dynamics and provide an opportunity to explore the transition from quasi-fission to multi-fragmentation. A new detection system, FAUST–QTS, has been commissioned at Texas A&M University in order to investigate the reaction dynamics in this transitional energy regime. FAUST–QTS is constructed through the coupling of the FAUST array to a large bore quadrupole triplet spectrometer, and designed to detect heavy fragments near the beam axis coincident with lighter particles

  1. Correlations between reaction product yields as a tool for probing heavy-ion reaction scenarios

    International Nuclear Information System (INIS)

    Gawlikowicz, W.; Agnihotri, D. K.; Baldwin, S. A.; Schroeder, W. U.; Toke, J.; Charity, R. J.; Sarantites, D. G.; Sobotka, L. G.; Souza, R. T. de; Barczyk, T.; Grotowski, K.; Micek, S.; Planeta, R.; Sosin, Z.

    2010-01-01

    Experimental multidimensional joint distributions of neutrons and charged reaction products were analyzed for 136 Xe + 209 Bi reactions at E/A=28, 40, and 62 MeV and were found to exhibit several different types of prominent correlation patterns. Some of these correlations have a simple explanation in terms of the system excitation energy and pose little challenge to most statistical decay theories. However, several other types of correlation patterns are difficult to reconcile with some, but not other, possible reaction scenarios. In this respect, correlations between the average atomic numbers of intermediate-mass fragments, on the one hand, and light particle multiplicities, on the other, are notable. This kind of multiparticle correlation provides a useful tool for probing reaction scenarios, which is different from the traditional approach of interpreting inclusive yields of individual reaction products.

  2. Lecture 2: Equilibrium statistical treatment of angular momenta associated with collective modes in fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1979-01-01

    The angular momentum effects in deep inelastic processes and fission have been studied in the limit of statistical equilibrium. The model consists of two touching liquid drop spheres. Angular momentum fractionation has been found to occur along the mass asymmetry coordinate. If neutron competition is included (i.e., in compound nucleus formation and fission), the fractionation occurs only to a slight degree, while extensive fractionation is predicted if no neutron competition occurs (i.e., in fusion--fission without compound nucleus formation). Thermal fluctuations in the angular momentum are predicted to occur due to degrees of freedom which can bear angular momentum, like wriggling, tilting, bending, and twisting. The coupling of relative motion to one of the wriggling modes, leading to fluctuations between orbital and intrinsic angular momentum, is considered first. Next the effect of the excitation of all the collective modes on the fragment spin is treated. General expressions for the first and second moments of the fragment spins are derived as a function of total angular momentum and the limiting behavior at large and small total angular momentum is examined. Furthermore, the effect of collective mode excitation on the fragment spin alignment is explored and is discussed in light of recent experiments. The relevance of the present study to the measured first and second moments of the γ-ray multiplicities as well as to sequential fission angular distributions is illustrated by applying the results of the theory to a well studied heavy ion reaction

  3. Study of the dynamical potential barriers in heavy ion collisions

    International Nuclear Information System (INIS)

    Zhu, Long; Su, Jun; Xie, Wen-Jie; Zhang, Feng-Shou

    2013-01-01

    The nucleus–nucleus interaction potentials for the fusion reactions 16 O + 208 Pb, 64 Ni + 64 Ni, 58 Ni + 58 Ni and 16 O + 154 Sm are extracted from the improved isospin-dependent quantum molecular dynamics model. The shell correction effects are discussed. The negative shell correction energies lower potential barriers of a certain reaction. The incident energy dependence of the potential barrier is investigated for each system. A complex phenomenon of energy dependence is observed. It is also found that incident energy dependence of the barrier radius and barrier height shows opposite behaviors. The Coulomb potential shows weak energy dependence when distance of two colliding nuclei is lower than the touching distance. The isospin effects of the potential barrier are investigated. The orientation effects of the potential barrier is also discussed for the system 16 O + 154 Sm. The fusion cross sections that correspond to the equatorial orientation of 154 Sm are very low in sub-barrier region because of the high fusion barriers and the shallow potential pockets

  4. An overview of relativistic hydrodynamics as applied to heavy ion reactions

    International Nuclear Information System (INIS)

    Strottman, D.D.

    1989-01-01

    The application of relativistic hydrodynamics as applied to heavy ions is reviewed. Constraints on the nuclear equation of state, as well as the form of the hydrodynamic equations imposed by causality are discussed. Successes (flow, side-splash, scaling) and shortcomings of one-fluid hydrodynamics are reviewed. Models for pion production within hydrodynamics and reasons for disagreement with experiment are assessed. Finally, the motivations for and the implementations of multi-fluid models are presented. 74 refs., 11 figs

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

    International Nuclear Information System (INIS)

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

    1986-07-01

    With the aid of an inverse dispersion relation, which gives the imaginary part of the fusion inclusive polarization potential (IPP) in terms of the principal part integral involving the real part of the IPP, the sub-barrier fusion of heavy ions is discussed. The system 16 O+ A Sm is taken as an example. The reactive content of the extracted IPP is analysed within the coupled channels theory. (Author) [pt

  6. Excitation of the Δ resonance in heavy ion charge exchange reactions

    International Nuclear Information System (INIS)

    Roy-Stephan, M.

    1987-06-01

    Results on the Δ excitation by heavy ion charge exchange are presented. 900 MeV per nucleon 12 C, 16 0, 20 Ne and 1100 MeV per nucleon 12 C have been used. The Δ excitation strength depends on the projectile - ejectile nature and on the incident energy. The role of the target mass is also discussed. The peak for the Δ in nuclei is energy shifted from the free Δ peak

  7. Proceedings of study meeting on microscopic and phenomenological research of interaction for light heavy-ion systems

    International Nuclear Information System (INIS)

    1991-06-01

    The Research Center for Nuclear Physics study meeting 'Microscopic and phenomenological research of interaction for light heavy-ion systems was held on March 7-9, 1990 as the study meeting in the second half of 1990, and 25 researchers took part in it. As the background of holding this study meeting, the fact that recently the rainbow scattering due to nuclear force was discovered experimentally in 16 O- 16 O system, and phenomenologically it was explained only by deep inter-nucleus potential. This should be evaluated as an important foothold for the research on the interaction for light heavy-ion systems and nuclear reaction mechanism. Accordingly, most of the papers presented this time were those related to the inter-nucleus potential and nuclear reaction mechanism. Also the development of theoretical analysis method was carried out and reported. Further, recently the experimental study on the structure and reaction of the neutron rich nucleus has advanced, and the theoretical research related to this topic was reported. (K.I.)

  8. Studies on the feasibility of heavy-ion beams for inertial confinement fusion

    International Nuclear Information System (INIS)

    1982-04-01

    This annual report summarizes the scientific results of work carried out in 1981 in the framework of a feasibility study for inertial confinement fusion (ICF) with heavy ion beams. This program, established in autumn 1979 and funded by the German Ministry for Science and Technology, is devoted in a first period until 1984 to the study of fundamental aspects of the field. Its principal aims are the investigation of key problems and the identification of critical issues of the heavy ion ICF concept in the fields of accelerator research, pellet physics, atomic physics, and reactor design. The research is carried out by about ten working groups at various German research centers and universities. In addition, together with a group of the University of Wisconsin a conceptual design study for a reactor plant (HIBALL) has been started in 1980 and was continued 1981. (orig.) [de

  9. Studies on the feasibility of heavy ion beams for inertial confinement fusion

    International Nuclear Information System (INIS)

    1985-08-01

    This Annual Report summarizes experimental and theoretical investigations carried out in the framework of a feasibility study of inertial confinement fusion by heavy ion beams, funded by the Federal Ministry for Research and Technology. After the completion of the conceptual design study HIBALL with an upgraded version, the investigations concentrated in 1984 mainly on problems of accelerator and target physics. In the area of accelerator physics the main interest was in the production and acceleration of high intensity heavy ion beams of high phase space density and in beam dynamics theory, in the area of target physics on beam-target interaction, radiation hydrodynamics, instabilities and the equation of state of highly compressed hot matter. (orig./AH)

  10. Studies of the QCD Phase Diagram with Heavy-Ion Collisions at J-PARC

    Science.gov (United States)

    Sako, Hiroyuki

    To clarify phase structures in the QCD phase diagram is an ultimate goal of heavy-ion collision experiments. Studies of internal structures of neutron stars are also one of the most important topics of nuclear physics since the discovery of neutron stars with two-solar mass. For these physics goals, J-PARC heavy-ion project (J-PARC-HI) has been proposed, where extremely dense matter with 5-10 times the normal nuclear density will be created. Heavy-ion beams up to Uranium will be accelerated to 1-19 AGeV/c, with the designed world's highest beam rate of 1011 Hz. The acceleration of such high-rate beams can be realized by a new heavy-ion linac and a new booster ring, in addition to the existing 3-GeV and 50-GeV proton synchrotrons. To study the above physics goals, following physics observables will be measured in extremely high statistics expected in J-PARC-HI. To search for the critical point, high-order event-by-event fluctuations of conserved charges such as a net-baryon number, an electric charge number, and a strangeness number will be measured. To study the chiral symmetry restoration, dilepton spectra from light vector meson decays will be measured. Also, collective flows, particle correlations will be measured to study the equation of state and hyperon-hyperon and hyperon-nucleon interactions related to neutron stars. Strange quark matter (strangelet) and multi-strangeness hypernuclei will be searched for which may be related directly to the matter constituting the neutron star core. In this work, the physics goals, the experimental design, and expected physics results of J-PARC-HI will be discussed.

  11. Positron annihilation and perturbed angular correlation studies of defects in neutron and heavy ion irradiated Si

    International Nuclear Information System (INIS)

    Zhu Shenyun; Li Anli; Li Donghong; Huang Hanchen; Zheng Shengnan; Du Hongshan; Ding Honglin; Gou Zhenhui; Iwata, T.

    1995-01-01

    The positron annihilation and perturbed angular correlation methods have been used to study the radiation damage induced defects in Si irradiated by the fast neutrons of 1.45x10 20 /cm 2 and the 178 W heavy ions of 5x10 11 /cm 2 . The divacancies, quadrivacancies and different types of monovacancy-, divacancy- and quadrivacancy-oxygen complexes were observed. The results obtained by both methods are consistent. (orig.)

  12. Betatron-collimation Studies for Heavy Ions in the FCC-hh

    CERN Multimedia

    Logothetis Agaliotis, Efstathios

    2018-01-01

    One of the biggest challenges in the design of the FCC-hh is the collimation system. From LHC experience it is known that a collimation system optimized for proton cleaning has a significantly reduced efficiency for heavy ions. The study presented in this contribution evaluates the betatron-collimation efficiency for the heavy-ion operation with lead nuclei at a beam energy of 50 Z TeV in the system designed for proton operation. The fragmentation processes of the main beam particles in the primary collimator are simulated with FLUKA and fragments are individually tracked with SixTrack until being lost in the downstream aperture. In this way a first-impact loss-map is obtained, identifying locations where high energy deposition are to be expected. This provides a first-level assessment of feasibility and allows to include countermeasures in the conceptual accelerator design.

  13. Development and performance of charged particle detectors applied to the study of heavy ion reactions; Developpement et performances de detecteurs de particules chargees appliques a l`etude des reactions avec ions lourds

    Energy Technology Data Exchange (ETDEWEB)

    Gourde, M; Beaulieu, L; Dore, D; Laforest, R; Pouliot, J; Roy, R; St-Pierre, C [Laval Univ., Quebec City, PQ (Canada). Dept. de Physique

    1994-12-31

    The new type of charged particle detector described comprises a thin layer of plastic scintillator over a much thicker CsI(Tl) crystal, an optical guide, and a photomultiplier. Results obtained at Chalk River Laboratories for the identification of particles with Z = 1-6 from the {sup 12}C + {sup 197}Au reaction are shown. 12 refs., 4 figs.

  14. Delta-electron spectroscopy: An aid for the determination of reaction times in heavy ion reactions

    International Nuclear Information System (INIS)

    Skapa, H.

    1983-01-01

    For the systems I->Au and I->Bi at an incident energy of 6.2 MeV/u (I->Au) and 6.6 MeV/u (I->Bi) the emission probability of delta electrons was determined. In an energy range from 150 KeV to 1000 KeV electrons were spectroscoped in coincidence to elastically, quasielastically, and deep inelastically scattered ions. In deep inelastic reaction between reaction products with high and without a mean mass drift was discriminated. The contribution of the conversion electrons, determined from gamma spectra, extends in the range of deep inelastic reactions of about 60%. While the ratio of conversion electrons for deep inelastic events with large to such without mass drift shows a flat, monotoneous growth for the ratio of the measured emission probabilities a oscillation-like structure with about 400 KeV width results. An interpretation of this structure as interference effect by nuclear time delay yields for the case of large mass drift a nuclear retention time of 7.5 x 10 -21 s. (orig./HSI) [de

  15. Study of jet quenching in heavy ion collisions at LHC using ATLAS detector

    CERN Document Server

    Štefko, Pavol

    2015-01-01

    Quark-Gluon Plasma (QGP) is one of the most extreme states of matter which exists only in extraordinary conditions of heavy-ion collisions that can be achieved at particle accelerators. Interactions between the partons and the hot, dense QGP are expected to cause the loss of the jet energy, which is phenomenon called jet quenching. In this talk we provide an introduction to the problematics of ultra-relativistic heavy ion collisions and we show how the jet quenching can be used to analyze the properties of QGP. We also present some “work in progress” results of the jet analysis done on the data taken by the ATLAS detector during the 2011 heavy-ion run at the LHC. Jets are studied as a function of collision centrality and dijet energy imbalance. Dijets are observed to be increasingly asymmetric with increasing centrality. The study of charged particles indicates an increase of yields of low- p T tracks in events with strongly quenched jets

  16. Studies on the feasibility of heavy ion beams for inertial confinement fusion

    International Nuclear Information System (INIS)

    1984-05-01

    The studies on the ''Feasibility of Heavy Ion Beams for Inertial Confinement'' funded by the German Ministry of Research and Technology have been continued in the same extent as in previous years. This Annual Report summarizes the scientific results of research carried out in the framework of this project at various research laboratories and universities. The principal aims of this research program are the identification and investigation of key issues of the heavy ion ICF concept based on a RF linac driver. Work done in 1983 concentrated on problems of accelerator and target physics: The theoretical investigations on the dynamics of high-intensity beams were continued. For the first time a low frequency RFQ for a high A/q ratio, to be used as a first unit of an injector, was put into operation. Theoretical target studies concentrated more on fundamental physics problems in the ICF targets, and on considerations for the generation of dense plasmas by intense beams of heavy ions. (orig./GG) [de

  17. Studies of relativistic heavy ion collisions at the AGS (Experiment 814)

    International Nuclear Information System (INIS)

    Cleland, W.E.

    1992-01-01

    During the past year, the Pittsburgh group has continued to work with the E814 collaboration in carrying out AGS Experiment 814. We present here a brief history of the experiment, followed by a detailed report of the analysis work being pursued at the University of Pittsburgh. As originally proposed, Experiment 814 is a study of both extreme peripheral collisions and the transition from peripheral to central collisions in relativistic heavy ion-nucleus interactions. We are studying relativistic heavy ion interactions with nuclei in two types of collisions: (a) extreme peripheral collisions of large impact parameter, and (b) central collisions with high transverse energy in the final state. The experiment emphasizes the measurement of overall event characteristics, in particular energy flow measurements and a precise measurement of the particle charge, momentum, and energy in the forward direction. This permits measurements of cross sections and rapidity densities as a function of the transverse energy for leading baryons emitted into regions of larger rapidity. Combining the energy flow measurements as a function of rapidity with the spectra of leading baryons provides information on the impact parameter dependence of the nuclear stopping of the projectile in relativistic heavy ion collisions. In 1988, the scope of Experiment 814 was enlarged to include a search for strange matter in central collisions, the first results of which have been published, and analysis on a longer run taken in 1990 is still under way

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

    International Nuclear Information System (INIS)

    Krolas, W.

    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 208 Pb + 64 Ni, 130 Te + 64 Ni and 208 Pb + 58 Ni systems have been created. The production cross sections of fragment isotopes have been determined and compared with existing model predictions

  19. 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

  20. Study of the continuum in heavy ion inelastic spectra by light particle coincidence measurements

    International Nuclear Information System (INIS)

    Scarpaci, J.A.; Blumenfeld, Y.; Chomaz, P.; Frascaria, N.; Garron, J.P.; Roynette, J.C.; Suomijarvi, T.; Van der Woude, A.; Alamanos, N.; Fernandez, B.; Gillibert, A.; Van der Woude, A.; Lepine, A.

    1990-01-01

    The continuum in heavy ion inelastic spectra contains, in addition to the excitation of target nucleus states, contributions from pick-up break-up and knock out reactions. In the case of the 40 Ca + 40 Ca collision at 50 MeV/N these contributions are separated and their relative importance assessed by the measurement of light charged particles in coincidence with the inelastically scattered fragments. The pick-up break-up contribution is found to make up less than half of the cross section at high excitation energies, conversely, the knock out process is important

  1. Proceedings of the Ninth High Energy Heavy Ion Study

    International Nuclear Information System (INIS)

    Chacon, A.D.; Justice, M.; Ritter, H.G.

    1993-01-01

    This report contains papers on the following topics: di-lepton production; multifragmentation; collective effects and flow; beam and radioactive beam studies; and scattering and particle production. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database

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

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Polycrystalline aluminum oxide is synthesized by combustion technique and XRD studies of the sample revealed the α-phase. ... of applications such as RF windows in fusion reactors, toroidal insulating breaks, diagnostic .... the crystal structure such as sample of different origin and substitution by different cations ...

  3. Relativistic heavy-ion physics

    CERN Document Server

    Herrera Corral, G

    2010-01-01

    The study of relativistic heavy-ion collisions is an important part of the LHC research programme at CERN. This emerging field of research focuses on the study of matter under extreme conditions of temperature, density, and pressure. Here we present an introduction to the general aspects of relativistic heavy-ion physics. Afterwards we give an overview of the accelerator facility at CERN and then a quick look at the ALICE project as a dedicated experiment for heavy-ion collisions.

  4. Contribution to the study of sputtering and damage of uranium dioxide by fast heavy ions

    International Nuclear Information System (INIS)

    Schlutig, S.

    2001-03-01

    Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO 2 targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited to describe our results. Finally, the sputtering yields are compared with a set of earlier experimental data on uranium dioxide damage obtained by T. Wiss and we observe that only a small fraction of UO 2 monolayers are sputtered. (author)

  5. Studies on the production of high energy densities in matter by intense heavy-ion beams

    International Nuclear Information System (INIS)

    Jacoby, J.

    1989-08-01

    In the framework of the present thesis the interaction of an intense heavy-ion beam with a small, but macroscopical amount of matter is studied. Thereby high energy densities in the target matter are produced. For this experiment it was for the first time possible to heat matter with ion beams from conventional heavy-ion accelerators up to plasma conditions. A KR + -ion beam was first accelerated with the heavy-ion accelerator MAXILAC to 45 keV/u and then focussed by a fine-focusing lens to a closed xenon gas target. The light emitted from the target was space- and time resolved taken up by a spectrometer as well as by a streak and CCD camera. Thereby the radial development of the plasma and the penetration behaviour of the ion beam was observed. The free electron density of the plasma was determined from the Stark broadening of emission lines (n e ≅ 4x10 16 cm -3 ). The temperature could be determined by different methods (shock-wave velocity, degree of ionization, line ratios). The electron temperature amounted in the center of the pipe to kT ≅ 0.75 eV. For the opacity of the target by which the emitted light power is determined under the assumption of the two-dimensional model (equilibrium between emitted and absorbed energy) the value κ p ≅ 7700 cm 2 /g resulted. (orig./HSI) [de

  6. Studies on the production of high energy density in matter with intense heavy-ion beams

    International Nuclear Information System (INIS)

    Jacoby, J.

    1989-01-01

    In the framework of the present thesis the interaction of an intense heavy-ion beam with a small, but macroscopic, amount of matter is studied. Thereby high energy densities are produced in the target matter. For this experiment it was for the first time possible to heat matter with ion beams from conventional heavy-ion accelerators up to plasma conditions. A Kr + ion beam was first accelerated with the heavy-ion accelerator MAXILAC to 45 keV/u and then focused by a fine-focusing lens on a closed xenon gas target. The light emitted from the target was space- and time-resolved taken up with a spectrometer as well a streak and CCD camera. Thereby the radial development of the plasma and the penetration behaviour of the ion beam were consecuted. The free-electron density of the plasma was determined from the Stark-broadening of emission lines (n e ≅ 4x10 16 cm -3 ). The electron temperature amounted in the center of the pipelet kT ≅ 0.75 eV. (orig./HSI) [de

  7. Simulation studies of acceleration of heavy ions and their elemental compositions

    International Nuclear Information System (INIS)

    Toida, Mieko; Ohsawa, Yukiharu

    1996-07-01

    By using a one-dimensional, electromagnetic particle simulation code with full ion and electron dynamics, we have studied the acceleration of heavy ions by a nonlinear magnetosonic wave in a multi-ion-species plasma. First, we describe the mechanism of heavy ion acceleration by magnetosonic waves. We then investigate this by particle simulations. The simulation plasma contains four ion species: H, He, O, and Fe. The number density of He is taken to be 10% of that of H, and those of O and Fe are much lower. Simulations confirm that, as in a single-ion-species plasma, some of the hydrogens can be accelerated by the longitudinal electric field formed in the wave. Furthermore, they show that magnetosonic waves can accelerate all the particles of all the heavy species (He, O, and Fe) by a different mechanism, i.e., by the transverse electric field. The maximum speeds of the heavy species are about the same, of the order of the wave propagation speed. These are in good agreement with theoretical prediction. These results indicate that, if high-energy ions are produced in the solar corona through these mechanisms, the elemental compositions of these heavy ions can be similar to that of the background plasma, i.e., the corona

  8. Moessbauer study of amorphous alloys irradiated with energetic heavy ions

    International Nuclear Information System (INIS)

    Kuzmann, E.; Spirov, I.N.

    1984-01-01

    The Moessbauer spectroscopy was applied to study radiation damages in amorphous alloys irradiated with 40 Ar (E=225 MeV) or 132 Xe (E=120 MeV) ions at room temperature. In the magnetically splitted Moessbauer spectra the dose-dependent decreases of the intensity of the 2nd and 5th lines as well as of the average hyperfine magnetic field were observed. The changes weAe also analysed using the hyperfine field distribution obtained from the spectra. The results are interpreted in terms of defect creation and structural changes of shortrange order of irradiated amorphoys alloys

  9. Scintillating screens study for LEIR/LHC heavy ion beams

    CERN Document Server

    Bal, C; Lefèvre, T; Scrivens, R; Taborelli, M

    2005-01-01

    It has been observed on different machines that scintillating ceramic screens (like chromium doped alumina) are quickly damaged by low energy ion beams. These particles are completely stopped on the surface of the screens, inducing both a high local temperature increase and the electrical charging of the material. A study has been initiated to understand the limiting factors and the damage mechanisms. Several materials, ZrO2, BN and Al2O3, have been tested at CERN on LINAC3 with 4.2MeV/u lead ions. Alumina (Al2O3) is used as the reference material as it is extensively used in beam imaging systems. Boron nitride (BN) has better thermal properties than Alumina and Zirconium oxide (ZrO2). BN has in fact the advantage of increasing its electrical conductivity when heated. This contribution presents the results of the beam tests, including the post-mortem analysis of the screens and the outlook for further measurements. The strategy for the choice of the screens for the Low Energy Ion Ring (LEIR), currently under ...

  10. Non local separable interactions in the description of some nuclear properties. Recoil and finite range effects in the CRC formalism for the study of heavy ion transfers

    International Nuclear Information System (INIS)

    Meyer, J.

    1976-01-01

    Some simplifications given by the nonlocal separable interactions (NLSI) allowed an exhaustive study of the three body problem to be performed. This work is intended to show that NLSI are also useful in studying the properties of nuclei. Some satisfactory results obtained in the infinite nuclear matter and also in the Hartree-Fock study of some 3s-1d nuclei are then given. A coupled reaction formalism has been developed for the analysis of heavy ion induced reactions. The recoil and finite range effects, which are necessary tools in heavy-ion induced reactions, have been introduced from the work of Coker et al. for the ( 3 He,t) reaction [fr

  11. Etching kinetics of swift heavy ion irradiated silicone rubber with insoluble additives or reaction products

    International Nuclear Information System (INIS)

    Fink, D.; Mueller, M.; Petrov, A.; Farenzena, L.; Behar, M.; Papaleo, R.P.

    2003-01-01

    It is normally understood as a basic precondition of the etching of swift heavy ion tracks in polymers that both the additives and etching products are soluble in the etchant. If this is not given, the polymer surface may be gradually blocked by the deposition of the insoluble material that acts as a diffusion barrier for the penetration of fresh etchant into the tracks, and therefore the effective track etching speed will gradually be reduced. The etching kinetics is developed for that case, and the theory is compared with first experimental findings. For that purpose we have taken commercial silicone rubber foils as test materials, that were irradiated with GeV heavy ions through a mask at a fluence that corresponds to the onset of track overlapping. After etching with NaOH, the corresponding etching speed was recorded via the reduction of the foil thickness. The etching speed is seen to decrease with exposure time, in parallel to the development of an insoluble surface layer. It is discussed how to prevent that surface blocking, to maintain a high etching speed

  12. Heavy-ion radiation chemistry

    International Nuclear Information System (INIS)

    Imamura, Masashi

    1975-01-01

    New aspect of heavy ion radiation chemistry is reviewed. Experiment has been carried out with carbon ions and nitrogen ions accelerated by a 160 cm cyclotron of the Institute of Physical and Chemical Research. The results of experiments are discussed, taking into consideration the effects of core radius depending on heavy ion energy and of the branch tracks of secondary electrons outside the core on chemical reaction and the yield of products. The effect of core size on chemical reaction was not able to be observed, because the incident energy of heavy ions was only several tens of MeV. Regarding high radical density, attention must be given to the production of oxygen in the core. It is possible to produce O 2 in the core in case of high linear energy transfer (LET), while no production of O 2 in case of low LET radiation. This may be one of study problems in future. LET effects on the yield of decomposed products were examined on acetone, methyl-ethyl-ketone and diethyl ketone, using heavy ions (C and N) as well as gamma radiation and helium ions. These three ketones showed that the LET change of two gaseous products, H 2 and CO, was THF type. There are peaks at 50-70 eV/A in the yield of both products. The peaks suggest the occurrence of ''saturation'' in decomposition. Attention was drawn to acetone containing a small amount (2 wt.%) of H 2 O. H 2 O and CO produced from this system differ from those in the pure system. The hydrogen connection formed by such a small amount of H 2 O may mediate the energy transfer. Sodium acetate tri-hydrate produces CH 3 radical selectively by gamma-ray irradiation at 77 K. In this case, the production of CH 2 COO - increases with the increase of LET of radiation. This phenomenon may be an important study problem. (Iwakiri, K.)

  13. Recent progress of hydrogen isotope behavior studies for neutron or heavy ion damaged W

    Energy Technology Data Exchange (ETDEWEB)

    Oya, Yasuhisa, E-mail: syoya@ipc.shizuoka.ac.jp [Shizuoka University, 836 Ohya, Suruga-ku Shizuoka 422-8529 (Japan); Hatano, Yuji [University of Toyama, 3190 Gofuku, Toyama 939-8555 (Japan); Shimada, Masashi [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Buchenauer, Dean; Kolasinski, Robert [Sandia National Laboratories, Livermore, CA 94551 (United States); Merrill, Brad [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Kondo, Sosuke; Hinoki, Tatsuya [Kyoto University, Gokasho, Uji 611-0011 (Japan); Alimov, Vladimir Kh. [University of Toyama, 3190 Gofuku, Toyama 939-8555 (Japan)

    2016-12-15

    Highlights: • This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. • Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. • The distribution of defects throughout the sample also changes the shape of TDS spectrum. • Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed. - Abstract: This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. In particular, the desorption temperature shifts higher as the defect concentration increases. In addition, the distribution of defects throughout the sample also changes the shape of TDS spectrum. Even if low energy traps were distributed in the bulk region, the D diffusion toward the surface requires additional time for trapping/detrapping during surface-to-bulk transport, contributing to a shift of desorption peaks toward higher temperatures. It can be said that both of distribution of damage (e.g. hydrogen isotope trapping sites) and their stabilities would have a large impact on desorption. In addition, transmutation effects should be also considered for an actual fusion environment. Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed.

  14. Recent progress of hydrogen isotope behavior studies for neutron or heavy ion damaged W

    International Nuclear Information System (INIS)

    Oya, Yasuhisa; Hatano, Yuji; Shimada, Masashi; Buchenauer, Dean; Kolasinski, Robert; Merrill, Brad; Kondo, Sosuke; Hinoki, Tatsuya; Alimov, Vladimir Kh.

    2016-01-01

    Highlights: • This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. • Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. • The distribution of defects throughout the sample also changes the shape of TDS spectrum. • Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed. - Abstract: This paper reviews recent results pertaining to hydrogen isotope behavior in neutron and heavy ion damaged W. Accumulation of damage in W creates stable trapping sites for hydrogen isotopes, thereby changing the observed desorption behavior. In particular, the desorption temperature shifts higher as the defect concentration increases. In addition, the distribution of defects throughout the sample also changes the shape of TDS spectrum. Even if low energy traps were distributed in the bulk region, the D diffusion toward the surface requires additional time for trapping/detrapping during surface-to-bulk transport, contributing to a shift of desorption peaks toward higher temperatures. It can be said that both of distribution of damage (e.g. hydrogen isotope trapping sites) and their stabilities would have a large impact on desorption. In addition, transmutation effects should be also considered for an actual fusion environment. Experimental results show that production of Re by nuclear reaction of W with neutrons reduces the density of trapping sites, though no remarkable retention enhancement is observed.

  15. Nuclear physics with heavy ions. 1

    International Nuclear Information System (INIS)

    Reif, R.; Schmidt, R.

    1981-01-01

    Some results obtained in nuclear physics with heavy ions in the energy range up to 10 MeV/nucleon are summarized. A short review of the tendencies in the development of heavy ion accelerators is followed by a classification of the mechanisms observed in heavy ion interactions. The characteristics of the various types of reactions are presented. Applications of heavy ion beams in other branches of sciences are discussed. (author)

  16. The role of collision terms for nucleon emission in intermediate energy heavy ion reactions

    International Nuclear Information System (INIS)

    Gregoire, C.; Scheuter, F.; Remaud, B.; Sebille, F.

    1984-01-01

    A semi-classical description of heavy ion collisions is developed with a particular attention to the nucleon flux from one partner through the other one. The phase-space extension of the nucleons is explicitly treated by means of the Wigner transform of the density matrix. Its dynamical evolution is obtained by solving the Landau-Vlasov equation, where collision terms are explicitely introduced. As a matter of fact, the experimental nucleon spectra usually described by a thermal source with an intermediate velocity (around vsub(beam)/2) are interpreted in our framework by the coexistence of one-and two-body dissipation. Multi-differential cross-sections d 2 σ/dEdΩ are computed for the 12 C(86MeV/u) + 12 C system and are compared with the experimental data. Comparisons are also given for the 16 O (20 MeV/u) + 197 Au system

  17. Studies on radiation symmetrization in heavy-ion driven hohlraum targets

    International Nuclear Information System (INIS)

    Temporal, M.; Atzeni, S.

    1993-01-01

    Radiation symmetrization within spherical, ellipsoidal and cylindral hohlraum targets for heavy ion inertial confinement fusion (ICF) is studied by means of a 3-D numerical, static model, in which realistic assumptions are made concerning the geometry of the system and, particularly, of the radiation converters. Among the systems so far studied, only spherical hohlraums with six converters achieve the illumination symmetry of the fusion capsule considered necessary for ICF applications. A parametric study of cylindrical hohlraums enlightens the effect of several parameter changes, and suggests directions for further studies, aiming at the design of two-converter targets

  18. Determination of cross sections of nuclear reactions to use Al as monitoring foil in heavy ion irradiation with 20Ne projectile

    International Nuclear Information System (INIS)

    Chowdhury, D.P.; Datta, J.; Guin, R.; Verma, R.

    2009-01-01

    The beam current is generally accurately measured using monitoring foils during the irradiation of thick samples by high energy ion beams. The cross sections of many nuclear reactions induced by light particles are available in literature for use as monitoring foil. However, such cross sections of heavy ion induced reactions are not reported much for their use in applied works. We have determined cross sections of two nuclear reactions, 27 Al ( 20 Ne,2p2n) 43 Sc and 27 Al ( 20 Ne, 2pn) 44m Sc, to use Al as monitoring foil for the irradiation with 20 Ne heavy ion beam. (author)

  19. Nuclear fission induced by heavy ions

    International Nuclear Information System (INIS)

    Newton, J.O.

    1988-09-01

    Because the accelerators of the 50's and 60's mostly provided beams of light ions, well suited for studying individual quantum states of low angular momentum or reactions involving the transfer of one or two nucleons, the study of fission, being an example of large-scale collective motion, has until recently been outside of the mainstream of nuclear research. This situation has changed in recent years, due to the new generation of accelerators capable of producing beams of heavy ions with energies high enough to overcome the Coulomb barriers of all stable nuclei. These have made possible the study of new examples of large-scale collective motions, involving major rearrangements of nuclear matter, such as deep-inelastic collisions and heavy-ion fusion. Perhaps the most exciting development in the past few years is the discovery that dissipative effects (nuclear viscosity) play an important role in fission induced by heavy ions, contrary to earlier assumptions that the viscosity involved in fission was very weak and played only a minor role. This review will be mainly concerned with developments in heavy-ion induced fission during the last few years and have an emphasis on the very recent results on dissipative effects. Since heavy-ion bombardment usually results in compound systems with high excitation energies and angular momenta, shell effects might be expected to be small, and the subject of low energy fission, where they are important, will not be addressed. 285 refs., 58 figs

  20. Studying the applicability of densities mixture unfolding for heavy ion jet spectra in the ALICE experiment

    CERN Document Server

    Hackstock, Philip

    2016-01-01

    The results of a three months summer project from July 4th 2016 to September 23rd are presented in this summer student report.\\\\ The method presented in the paper\\footnote{\\url{http://www.sciencedirect.com/science/article/pii/S0168900215000406}} on densities mixture unfolding by Nikolay Gagunashvili and its software implementation were studied. A mind map flowchart, plotting macros and documentation were produced and while an 18 fold performance boost trough parallelization could be achieved, the verdict on the applicability of this method for heavy ion jet spectra in the ALICE experiment remains inconclusive. This is mainly due to a lack of time and complexity of the method and its implementation.

  1. Study of recirculating induction accelerator as drivers for heavy ion fusion

    International Nuclear Information System (INIS)

    Shay, H.D.; Barnard, J.J.; Brooks, A.L.; Coffield, F.; Deadrick, F.; Griffith, L.V.; Kirbie, H.C.; Neil, V.K.; Newton, M.A.; Paul, A.C.

    1993-01-01

    Two years ago, Lawrence Livermore National Laboratory (LLNL) began a study of the viability and relative utility of recirculating induction accelerators as drivers for Heavy Ion Fusion (HIF). The final draft of the report detailing the results in 284 pages was completed in September, 1991. As well as broadly involving the collaboration of many researchers from several groups at LLNL, it also benefited from contributions from several individuals in the HIF program at Lawrence Berkeley Laboratory and from others in the HIF community nationwide. This presentation summarizes the key findings given in that report

  2. Experimental study of the transport limits of intense heavy ion beams in the HCX

    International Nuclear Information System (INIS)

    Prost, L.R.; Bieniosek, F.M.; Celata, C.M.; Dugan, C.C.; Faltens, A.; Seidl, P.A.; Waldron, W.L.; Cohen, R.; Friedman, A.; Kireeff Covo, M.; Lund, S.M.; Molvik, A.W.; Haber, I.

    2004-01-01

    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 space-charge intensity (line charge density up to ∼ 0.2 (micro)C/m) over long pulse durations (4 (micro)s) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. The experiment also contributes to the practical baseline knowledge of intense beam manipulations necessary for the design, construction and operation of a heavy ion driver for inertial fusion. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and beam steering, matching, image charges, halo, electron cloud effects, and longitudinal bunch control. We first present the results for a coasting 1 MeV K + ion beam transported through the first ten electrostatic transport quadrupoles, measured with optical beam-imaging and double-slit phase-space diagnostics. This includes studies at two different radial fill factors (60% and 80%), for which the beam transverse distribution was characterized in detail. Additionally, beam energy measurements will be shown. We then discuss the first results of beam transport through four pulsed room-temperature magnetic quadrupoles (located downstream of the electrostatic quadrupoles), where the beam dynamics become more sensitive to the presence of secondary electrons

  3. Heavy ion accelerator GANIL

    International Nuclear Information System (INIS)

    1975-04-01

    This article presents GANIL, a large national heavy ion accelerator. The broad problems of nuclear physics, atomic physics, astrophysics and physics of condensed media which can be approached and studied with this machine are discussed first, after which the final construction project is described. The project comprises a circular injector, a separated sector cyclotron up beam stripper, and a second separated cyclotron downstream [fr

  4. Past, present and future aspects of studies of heavy ion radiotherapy. 2. Future view of clinical studies of heavy ion radiotherapy

    International Nuclear Information System (INIS)

    Tsujii, Hirohiko; Kamata, Tadashi

    2007-01-01

    The purpose of clinical studies of heavy ion radiotherapy (HIR, using carbon beam) in National Institute of Radiological Sciences (NIRS) is, in treatment of cancers, to elucidate its potential and significance for establishing the methodology for curing the disease safely and reliably to further spread the therapy. Here is presented a future view of clinical studies of HIR based on the past results and along authorities' medical policy. NIRS has treated 3,100 or more cancer patients in about 50 clinical trials from the start of HIR in 1994. In those studies, curing the intractable malignancies has become possible in a short term of therapy, and the irradiating machine is being miniaturized (actually under construction in Gunma Univ.). At the end of 2006, about 4,000 patients have been treated with HIR globally: the impact of NIRS HIR. There are such future HIR plans as the promotion of clinical trials, development of irradiation technology, promotion and efficient practice as an advanced frontier medicare, imaging diagnosis for the aim of treatment, biological studies, and comparative studies to elucidate the usefulness. Cooperation of NIRS, manufacturers and authorities will make HIR a more useful, less burdensome mean to treat patients with more intractable cancers. (R.T.)

  5. Investigation of incomplete linear momentum transfer in heavy ion reactions at intermediate energies

    International Nuclear Information System (INIS)

    Leray, S.

    1986-07-01

    At intermediate energies, heavy ion central collisions lead to the incomplete fusion of the incident nuclei while part of the initial linear momentum is carried away by fast light particles. Experiments were performed with 30 MeV per nucleon neon and 20, 35 and 44 MeV per nucleon argon projectiles bombarding heavy targets. Results obtained with 30 MeV per nucleon neon and 20 MeV per nucleon argon beams are in good agreement with an empirical law established with lighter projectiles. On the contrary, 35 and 44 MeV per nucleon argon projectiles do not follow the same law and fission fragments progressively disappear. A simple model explains the evolution of the amount of transferred linear momentum versus incident energy. The disappearance of the fusion products of the composite system observed with argon projectiles beyond 35 MeV per nucleon is explained by a limitation of the excitation energy per nucleon which can be deposited in a nucleus. The limit is evaluated from nucleon binding energy in nuclei and probability to emit clusters and is in good agreement with experimental data. Because of the coupling between intrinsic motion of nucleons and relative motion of nuclei, some nucleons have a kinetic energy high enough to be emitted: a theoretical model is proposed which rather well fits the data concerning fast nucleons but cannot explain the measured amounts of transferred linear momentum. This is attributed to the existence of other mechanisms [fr

  6. Effects of rotation on the stability of nuclei under fission and the possibility of fusion in heavy-ion reactions

    International Nuclear Information System (INIS)

    Mustafa, M.G.; Kumar, K.

    1975-06-01

    The two-center shell model for fission is extended to include the effects of nuclear rotation or angular momentum J. The principle of minimization of total nuclear energy with respect to a constraint on J leads to an effective potential energy which depends on J as well as moment of inertia. This effective potential energy is minimized with respect to nuclear shape variables, neutron pairing energy gap, and proton pairing energy gap for each J value. The resulting potential minima, fission barriers, and moments of inertia are quite sensitive to J. Results are given for 208 82 Pb, 240 94 Pu, and for a super-heavy nucleus, 298 114 X. Microscopic calculations of the critical angular momentum (at which the fission barrier vanishes) are compared with the rotating liquid drop calculations of Cohen, Plasil, and Swiatecki. The influence of these results on the possibility of fusion in heavy-ion reactions is discussed. (5 figures, 6 tables) (U.S.)

  7. Studies on the feasibility of heavy ion beams for inertial confinement fusion

    International Nuclear Information System (INIS)

    1983-05-01

    This Annual Report summarizes the scientific results of work carried out in 1982 in the framework of a feasibility study for inertial confinement fusion with heavy ion beams funded by the German Ministry of Research and Technology. The principal aim of this basic research program is the investigation of key problems and the identification of critical issues of the heavy ion ICF concept in the fields of accelerator research, atomic physics, target physics, and reactor design. The research is carried out by about ten working groups at various research centers and universities. One of the highlights in 1982 was a symposium held end of March at GSI which focussed on a critical analysis of the HIBALL accelerator concept. Whereas technical issues and hardware parameters were found feasible the beam dynamics in the storage rings turned out to be beyond the so far believed stability limits. As a consequence a revised accelerator scenario based on a lower charge state and a higher linac current has been investigated during the last year. First considerations were made on an experimental facility necessary for the study of high-intensity beam dynamics and of beam target interaction. Experimental studies of this kind will be of increasing importance for the future of the project. (orig.) [de

  8. 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...

  9. Studies on heavy ion losses from collimation cleaning at the LHC

    CERN Document Server

    Hermes, P D; Jowett, J M; Redaelli, S; Salvachua, B M; Valentino, G; Wollmann, D

    2015-01-01

    The LHC collimation system protects superconducting magnets from beam losses. By design, it was optimized for the high-intensity proton challenges but so far provided adequate protection also during the LHC heavy-ion runs with 208Pb82+ ions up to a beam energy of 4 Z TeV. Ion beam cleaning brings specific challenges due to different physical interactions with the collimator materials and might require further improvements for operation at 7 Z TeV. In this article, we study heavy-ion beam losses leaking out of the LHC collimation system, both in measurement and simulations. The simulations are carried out using both ICOSIM, with a simplified ion physics model implemented, and SixTrack, including more detailed starting conditions from FLUKA but without including online scattering in subsequent collimator hits. The results agree well with measurements overall, although some discrepancies are present. The reasons for the discrepancies are investigated and, on this basis, the requirements for an improved simulatio...

  10. Molecular resonances, fusion reactions and surface transparency of interaction between heavy ions

    International Nuclear Information System (INIS)

    Abe, Yasuhisa.

    1980-01-01

    A review of the Band Crossing Model is given, including recent results on the 16 O + 16 O system. Surface Transparency is discussed in the light of the recent development in our understanding of the fusion reaction mechanisms and by calculating the number of open channels available to direct reactions. The existence of the Molecular Resonance Region is suggested in several systems by the fact that Band Crossing Region overlaps with the Transparent Region. A systematic study predicts molecular resonances in the 14 C + 14 C and 12 C + 14 C systems as prominent as those observed in the 16 O + 16 O and 12 C + 16 O systems

  11. 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.

  12. Accelerator-Based Studies of Heavy Ion Interactions Relevant to Space Biomedicine

    Science.gov (United States)

    Miller, J.; Heilbronn, L.; Zeitlin, C.

    1999-01-01

    Alternating Gradient Synchrotron at Brookhaven National Laboratory (BNL AGS) and the Heavy Ion Medical Accelerator (HIMAC) in Chiba, Japan. Until fairly recently most of these experiments were done to investigate fundamental problems in nuclear physics, but with the increasing interest in heavy charged particles on the part of the space flight, radiobiology and radiotherapy communities, an increasing number of experiments are being directed at these areas. Some of these measurements are discussed in references therein. Over the past several years, our group has taken cross section and fluence data at the AGS and HIMAC for several incident beams with nuclear charge, Z, between 6 and 26 at energies between 290 and 1050 MeV/nucleon. Iron (Z = 26) has been studied most extensively, since it is the heaviest ion present in significant numbers in the GCR. Targets have included tissue-equivalent and proposed shielding materials, as well as a variety of elemental targets for cross section measurements. Most of the data were taken along the beam axis, but measurements have been made off-axis, as well. Here we present selected data and briefly discuss some implications for spacecraft and planetary habitat design.

  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. Establishing the transport properties of QCD with heavy ion reactions. Final Scientific Report for DE-FG02-07ER41524

    International Nuclear Information System (INIS)

    Teaney, Derek

    2008-01-01

    During the time period from 9/1/07 - 3/1/08 the principle investigator was awarded a federal grant from the Department of Energy (DE-FG02-07ER41524) to establish the transport properties of QCD through heavy ion reactions. A relativistic viscous hydrodynamic computer code was developed in 2+1 dimensions which is suitable for extracting the shear viscosity from available heavy ion data. In addition, the transport coefficients of heavy mesons in strongly coupled N = 4 plasmas were determined using the gauge gravity duality. These transport coefficients are suppressed by 1/N c 2 which stymied previous efforts to determine the kinetics of these mesons.

  15. Fission fragment yields from heavy-ion-induced reactions measured with a fragment separator

    Science.gov (United States)

    Tarasov, O. B.; Delaune, O.; Farget, F.; Morrissey, D. J.; Amthor, A. M.; Bastin, B.; Bazin, D.; Blank, B.; Cacéres, L.; Chbihi, A.; Fernández-Dominguez, B.; Grévy, S.; Kamalou, O.; Lukyanov, S. M.; Mittig, W.; Pereira, J.; Perrot, L.; Saint-Laurent, M.-G.; Savajols, H.; Sherrill, B. M.; Stodel, C.; Thomas, J. C.; Villari, A. C.

    2018-04-01

    The systematic study of fission fragment yields under different initial conditions has provided valuable experimental data for benchmarking models of fission product yields. Nuclear reactions using inverse kinematics coupled to the use of a high-resolution spectrometer with good fragment identification are shown here to be a powerful tool to measure the inclusive isotopic yields of fission fragments. In-flight fusion-fission was used in this work to produce secondary beams of neutron-rich isotopes in the collisions of a 238U beam at 24 MeV/u with 9Be and 12C targets at GANIL using the LISE3 fragment separator. Unique identification of the A, Z, and atomic charge state, q, of fission products was attained with the Δ E- TKE-B ρ- ToF measurement technique. Mass, and atomic number distributions are reported for the two reactions. The results show the importance of different reaction mechanisms in the two cases. The optimal target material for higher yields of neutron-rich high- Z isotopes produced in fusion-fission reactions as a function of projectile energy is discussed.

  16. Light particle emission measurements in heavy ion reactions. Final report, June 1, 1981-May 31, 1984

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1984-01-01

    Progress in instrumentation development reported includes improvements in the design of position sensitive neutron detectors, design of a thin-walled, spherical, aluminum target chamber, and use of thin silicon detectors to detect and identify evaporation residues from fusion reactions. The problem of the short lifetime of evaporation residue detectors is addressed by using a pair of large area, multi-wire proportional counters followed by a thin sheet of plastic scintillator. Neutron emission associated with fission has been studied, as well as nonequilibrium emission associated with inelastic products and evaporation residue. An experiment was performed to study neutron emission associated with fission and fission-like events in the case of the Er composite system. Other work in progress includes neutron emissions from the C + Gd and Ne + Nd reactions. 9 refs

  17. Proceedings of the international conference on dynamical properties of heavy-ion reactions held at the University of the Witwatersrand, v. 1

    International Nuclear Information System (INIS)

    Engelbrecht, C.A.; Lemmer, R.H.; Sellschop, J.P.F.; Toeppfer, C.

    1978-01-01

    The report contains abstracts of the papers delivered at the conference. The abstracts have been grouped into the following chapters: Very heavy nuclei; Deep inelastic reactions and fusion; Resonances; Elastic and quasi-elastic scattering; Atomic physics with heavy ions; Miscellaneous; Post-deadline contributions. Each abstract has been submitted to INIS separately

  18. Neutron-proton bremsstrahlung from intermediate energy heavy-ion reactions as a probe of the nuclear symmetry energy?

    International Nuclear Information System (INIS)

    Yong, G.-C.; Li Baoan; Chen Liewen

    2008-01-01

    Hard photons from neutron-proton bremsstrahlung in intermediate energy heavy-ion reactions are examined as a potential probe of the nuclear symmetry energy within a transport model. Effects of the symmetry energy on the yields and spectra of hard photons are found to be generally smaller than those due to the currently existing uncertainties of both the in-medium nucleon-nucleon cross sections and the photon production probability in the elementary process pn→pnγ. Very interestingly, nevertheless, the ratio of hard photon spectra R 1/2 (γ) from two reactions using isotopes of the same element is not only approximately independent of these uncertainties but also quite sensitive to the symmetry energy. For the head-on reactions of 132 Sn + 124 Sn and 112 Sn + 112 Sn at E beam /A=50 MeV, for example, the R 1/2 (γ) displays a rise up to 15% when the symmetry energy is reduced by about 20% at ρ=1.3ρ 0 which is the maximum density reached in these reactions

  19. X detection in heavy ion induced reactions. Application to the lifetime measurement of a compound nucleus

    International Nuclear Information System (INIS)

    Liatard, E.

    1984-01-01

    The ionization of inner electronic shells can be used to determine the lifetime of a compound nucleus formed in a nuclear reaction. The principle of the measure is based on the comparison between the unknown lifetime of the nuclear process and the known lifetime of a K-shell vacancy created during the collision. Besides testing this method, which we call the ''atomic-clok'' method with the compound nucleus 112 Te formed by the reaction 20 Ne (205 MeV) + 92 Mo, the work in this thesis basically consists of a description and a study of the problems presented by the use of X-ray spectroscopy in nuclear-decay-time measurements and Z-identification of heavy nuclear products [fr

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

    International Nuclear Information System (INIS)

    Wang, Fuqiang

    2007-01-01

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

  1. Studies of heavy ion beam transport in a magnetic quadrupole channel

    International Nuclear Information System (INIS)

    Klabunde, J.; Reiser, M.; Schonlein, A.; Spadtke, P.; Struckmeier, J.

    1983-01-01

    In connection with the West German Heavy Ion Fusion Program the first stage (six periods) of a magnetic quadrupole channel (FODO type) to study the transport of intense ion beams was built at GSI. Different ion beams can be used and the variation of the brightness of these beams (hence of the tune depression sigma/sigma /SUB o/ ) is sufficiently large that regions of theoretically predicted instabilities can be covered. The initial studies are being carried out with a high-brightness beam of 190 keV Ar+ ions and currents of a few mA. Since the pulse length is > 0.5 ms and the pressure is between 10 -6 and 10 -7 torr partial space charge neutralization occurs. Clearing electrodes can be used to remove the electrons from the beam. Results of theoretical studies, measurements of charge neutralization effects and first results of transport experiments are reported

  2. Study of the 6Li+16O light heavy-ion system around the Coulomb barrier

    International Nuclear Information System (INIS)

    Glasner, K.; Ricken, L.; Kuhlmann, E.

    1986-01-01

    Total cross sections of the light heavy-ion reactions 16 O( 6 Li,p) 21 Ne, i=0-10, have been measured for beam energies Esub(Li)=4.5-8.0 MeV in steps of 100 keV. Additional excitation functions of the inclusive reactions 16 O( 6 Li,xy), x=p, n and α, were taken for Esub(li)=4.1-12.5 MeV. The 6 Li+ 16 O reaction can be understood as a predominant compound-nucleus process as extensive Hauser-Feshbach calculations show. A comprehensive statistical analysis yields a coherence width GAMMA=130+-20 keV for Esub(x)( 22 Na)approx.=19 MeV. Statistically significant deviations from pure fluctuation phenomena are found in most excitation functions at Esub(x)( 22 Na)=17.9, 18.4, 19.2 and 20.2 MeV. Interpreting these structures with widths 400<=GAMMAsub(tot)<=800 keV as intermediate-width resonances in terms of rotational band, tentative spin assignments can be given. (orig.)

  3. HIBALL - a conceptual heavy ion beam driven fusion reactor study. Vol. 1

    International Nuclear Information System (INIS)

    Badger, B.; El-Guebaly, L.; Engelstad, R.; Hassanein, A.; Klein, A.; Kulcinski, G.; Larsen, E.; Lee, K.; Lovell, E.; Moses, G.

    1981-12-01

    A preliminary concept for a heavy-ion beam driven inertial confinement fusion power plant is presented. The high repetition rate of the RF accelerator driver is utilized to serve four reactor chambers alternatingly. In the chambers a novel first-wall protection scheme is used. At a target gain of 83 the total net electrical output is 3.8 GW. The recirculating power fraction is below 15%. The main goal of the comprehensive HIBALL study (which is continuing) is to demonstrate the compatibility of the design of the driver, the target and the reactor chambers. Though preliminary, the present dessign is essentially self-consistent. Tentative cost estimates are given. The costs compare well with those found in similar studies on other types of fusion reactors. (orig.) [de

  4. Structure and dynamics of highly charged heavy ions studied with the electron beam ion trap in Tokyo

    International Nuclear Information System (INIS)

    Nakamura, Nobuyuki; Hu, Zhimin; Watanabe, Hirofumi; Li, Yueming; Kato, Daiji; Currell, Fred J.; Tong Xiaomin; Watanabe, Tsutomu; Ohtani, Shunsuke

    2011-01-01

    In this paper, we present the structure and the dynamics of highly charged heavy ions studied through dielectronic recombination (DR) observations performed with the Tokyo electron beam ion trap. By measuring the energy dependence of the ion abundance ratio in the trap at equilibrium, we have observed DR processes for open shell systems very clearly. Remarkable relativistic effects due to the generalized Breit interaction have been clearly shown in DR for highly charged heavy ions. We also present the first result for the coincidence measurement of two photons emitted from a single DR event.

  5. Dosimetry in radiobiological studies with the heavy ion beam of the Warsaw cyclotron

    International Nuclear Information System (INIS)

    Kaźmierczak, U.; Banaś, D.; Braziewicz, J.; Czub, J.; Jaskóła, M.; Korman, A.; Kruszewski, M.; Lankoff, A.; Lisowska, H.; Malinowska, A.; Stępkowski, T.; Szefliński, Z.

    2015-01-01

    The aim of this study was to verify various dosimetry methods in the irradiation of biological materials with a 12 C ion beam at the Heavy Ion Laboratory of the University of Warsaw. To this end the number of ions hitting the cell nucleus, calculated on the basis of the Si-detector system used in the set-up, was compared with the number of ion tracks counted in irradiated Solid State Nuclear Track Detectors and with the number of ion tracks detected in irradiated Chinese Hamster Ovary cells processed for the γ-H2AX assay. Tests results were self-consistent and confirmed that the system serves its dosimetric purpose.

  6. Studies of relativistic heavy ion collisions at the AGS (E814/E877)

    International Nuclear Information System (INIS)

    Cleland, W.E.

    1993-01-01

    Efforts have continued in the area of peripheral and central collisions of relativistic heavy ions. In the area of peripheral collisions, the analysis of the 1n and 2p decay channels has been completed. In the area of central collisions, the first measurement of the E T distributions in Au + Au collisions, through the use of the participant calorimeter, was completed, and the results were compared with those obtained in collisions with Si projectiles. In addition, a thorough study of two-particle correlation functions was carried out by use of the data from the silicon pad multiplicity detector. Differential cross sections for 14.6-GeV/c 28 Si on Al, Cu, and Pb, and 11.4-GeV/c 197 Au on Al, Cu, Au, and Pb are given. 32 figs., 4 tabs., 24 refs

  7. Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials.

    Science.gov (United States)

    Kulriya, P K; Singh, F; Tripathi, A; Ahuja, R; Kothari, A; Dutt, R N; Mishra, Y K; Kumar, Amit; Avasthi, D K

    2007-11-01

    An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90 MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T=255 K.

  8. Dosimetry in radiobiological studies with the heavy ion beam of the Warsaw cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kaźmierczak, U. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, 02-093 Warsaw (Poland); Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Banaś, D.; Braziewicz, J. [Institute of Physics, Jan Kochanowski University, ul. Świętokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Czub, J. [Institute of Physics, Jan Kochanowski University, ul. Świętokrzyska 15, 25-406 Kielce (Poland); Jaskóła, M.; Korman, A. [National Centre for Nuclear Research, ul. Andrzeja Sołtana 7, 05-400 Otwock (Poland); Kruszewski, M. [Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland); Institute of Rural Health, ul. Jaczewskiego 2, 20-090 Lublin (Poland); Lankoff, A. [Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland); Institute of Biology, Jan Kochanowski University, ul. Świętokrzyska 15, 25-406 Kielce (Poland); Lisowska, H. [Institute of Biology, Jan Kochanowski University, ul. Świętokrzyska 15, 25-406 Kielce (Poland); Malinowska, A. [National Centre for Nuclear Research, ul. Andrzeja Sołtana 7, 05-400 Otwock (Poland); Stępkowski, T. [Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland); Szefliński, Z. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, 02-093 Warsaw (Poland); and others

    2015-12-15

    The aim of this study was to verify various dosimetry methods in the irradiation of biological materials with a {sup 12}C ion beam at the Heavy Ion Laboratory of the University of Warsaw. To this end the number of ions hitting the cell nucleus, calculated on the basis of the Si-detector system used in the set-up, was compared with the number of ion tracks counted in irradiated Solid State Nuclear Track Detectors and with the number of ion tracks detected in irradiated Chinese Hamster Ovary cells processed for the γ-H2AX assay. Tests results were self-consistent and confirmed that the system serves its dosimetric purpose.

  9. Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials

    Science.gov (United States)

    Kulriya, P. K.; Singh, F.; Tripathi, A.; Ahuja, R.; Kothari, A.; Dutt, R. N.; Mishra, Y. K.; Kumar, Amit; Avasthi, D. K.

    2007-11-01

    An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T =255K.

  10. Study on relations between heavy ions single event upset cross sections and γ accumulated doses

    International Nuclear Information System (INIS)

    He Chaohui; Geng Bin; Wang Yanping; Peng Honglun; Yang Hailiang; Chen Xiaohua; Li Guozheng

    2002-01-01

    Experiments were done under 252 Cf and 60 Co γ source to study the relation between heavy ion Single Event Upset (SEU) cross sections and γ accumulated doses. There was no obvious rule and little influence of γ accumulated doses on SEU cross sections when Static Random Access Memories were in power off mode and static power on mode. In active measuring mode, the SEU cross section increased as the accumulated doses increasing when same data were written in memory cells. If reverse data, such as '55' and 'AA', were written in memory cells during the experiment, the SEU cross sections decreased to the level when memories were not irradiated under 60 Co γ source, even more small. It implied that the influence of γ accumulated doses on SEU cross sections can be set off by this method

  11. Generation and scaling behaviour of high-energy pions in relativistic heavy ion reactions

    International Nuclear Information System (INIS)

    Riess, F.

    1979-12-01

    Calculations with the help of a collision approximation as carried out in this study, are certainly linked with many uncertainties. The different forms of pulse distributions and cross sections used cover however such a broad region of possibilities, that even detailed calculations will not give any results essentially deviating from those obtained here. The various assumptions and statements could be relatively easily investigated using the collision approximation. Hence the above-mentioned aim, to pick out the principal information from the statement is achieved. It was shown that taking the two assumptions - nucleon-nucleon collisions only and - consideration of a cluster effect, in both cases the experimental results for a given reaction can be well reproduced as long as one only regards one projectile energy. It is important in the first case that the pulse distribution in the region of 0,5 to 1 GeV/c contains sufficiently large components - a simple Gauss distribution with a 'normal' parameter from nuclean physics is not sufficient here. The cluster statement provides the high-energy pions through the changed kinematics, compared to pure nucleon-nucleon collisions, and through the greater energy provided by a cluster in the reaction. (orig./HSI) [de

  12. 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.

  13. Isospin and angular momentum effects in the peripheral heavy ion reactions

    International Nuclear Information System (INIS)

    Jouault, B.; De La Mota, V.; Sebille, F.; Royer, G.; Lecolley, J. F.

    1997-01-01

    The semi-classical Landau Vlasov model has been used to investigate the decay modes of peripheral Pb + Au reactions at 29 MeV/n. Statics and dynamics of these very massive nuclei are analyzed especially through the isospin dependence of the effective nuclear force. The degree of dissipation of the collisions is studied for different bins of impact parameter pointing out the influence of the nucleon-nucleon cross section. The appearance of intermediate mass fragments from neck-like structures is evidenced and the effects of angular momentum transfers are shown to play a fundamental role in this phenomenon. The theoretical results are compared with experimental data, showing the importance of the dynamical and out of equilibrium effects on the observables. (authors)

  14. Subthreshold pion production study with heavy ions at low and medium energy

    International Nuclear Information System (INIS)

    Rebreyend, D.

    1988-02-01

    In the domain of subthreshold pion production with heavy ions at low and medium energy (40-100 MeV/u), only Π 0 have been up to now, extensively studied. The incompleteness of the charged pion data and especially the lack of results for pions of energy less than 30 MeV have led to conceive the magnetic spectrometer SPIC. In the present work, we demonstrate that this spectrometer is particularly well suited for the detection of low energy charged pions (Inferior threshold of detection: T Π = 7 MeV), emitted around 0 0 in heavy ion collisions. Principle and performances, successfully tested at 38 and 93 MeV/u, are described in detail. The main characteristics of a Π 0 spectrometer, that was used to realize a comparative experiment of Π 0 production, are then given. The last chapter is devoted to experimental results. First, we present the results obtained with the 16 0 beam of 38 MeV/u of the SARA accelerator, in charged pions (Al and Ni targets) and in Π 0 (Al and Au targets). A comparison of the data Π - /Π 0 seems to indicate that coulomb effects are surprisingly small. Finally, we report the data obtained with the 16 0 beam of 93 MeV/u of GANIL. In contrast with low energy data, coulomb effects are very strong (ratio Π - /Π + = 100 for pions of low energy with heavy targets) and allowed us to extract informations on the geometry of the collision [fr

  15. Studies in High Current Density Ion Sources for Heavy Ion Fusion Applications

    International Nuclear Information System (INIS)

    Chacon-Golcher, E.

    2002-01-01

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

  16. Studies in High Current Density Ion Sources for Heavy Ion Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chacon-Golcher, Edwin [Univ. of California, Berkeley, CA (United States)

    2002-06-01

    This dissertation develops diverse research on small (diameter ~ few mm), high current density (J ~ several tens of mA/cm2) heavy ion sources. The research has been developed in the context of a programmatic interest within the Heavy Ion Fusion (HIF) Program to explore alternative architectures in the beam injection systems that use the merging of small, bright beams. An ion gun was designed and built for these experiments. Results of average current density yield () at different operating conditions are presented for K+ and Cs+ contact ionization sources and potassium aluminum silicate sources. Maximum values for a K+ beam of ~90 mA/cm2 were observed in 2.3 μs pulses. Measurements of beam intensity profiles and emittances are included. Measurements of neutral particle desorption are presented at different operating conditions which lead to a better understanding of the underlying atomic diffusion processes that determine the lifetime of the emitter. Estimates of diffusion times consistent with measurements are presented, as well as estimates of maximum repetition rates achievable. Diverse studies performed on the composition and preparation of alkali aluminosilicate ion sources are also presented. In addition, this work includes preliminary work carried out exploring the viability of an argon plasma ion source and a bismuth metal vapor vacuum arc (MEVVA) ion source. For the former ion source, fast rise-times (~ 1 μs), high current densities (~ 100 mA/cm+) and low operating pressures (< 2 mtorr) were verified. For the latter, high but acceptable levels of beam emittance were measured (εn ≤ 0.006 π· mm · mrad) although measured currents differed from the desired ones (I ~ 5mA) by about a factor of 10.

  17. Quasi-elastic scattering an alternative tool for mapping the fusion barriers for heavy-ion induced fusion reaction

    International Nuclear Information System (INIS)

    Behera, B.R.

    2016-01-01

    Heavy element synthesis through heavy-ion induced fusion reaction is an active field in contemporary nuclear physics. Exact knowledge of fusion barrier is one of the essential parameters for planning any experiments for heavy element production. Theoretically there are many models available to predict the exact barrier. Though these models are successful for predicting the fusion of medium mass nuclei, it somehow fails for predicting the exact location of barrier for fusion of heavy nuclei. Experimental determination of barrier for such reactions is required for future experiments for the synthesis of heavy elements. Traditionally fusion barrier is determined taking a double derivative of fusion excitation function. However, such method is difficult in case of fusion of heavy nuclei due to its very low fusion/capture cross section and its experimental complications. Alternatively fusion barrier can be determined by measuring the quasi-elastic cross section at backward angles. This method can be applied for determining the fusion barrier for the fusion of heavy nuclei. Experimental determination of fusion barrier by different methods and comparison of the fusion excitation function and quasi-elastic scattering methods for the determination of fusion barrier are reviewed. At IUAC, New Delhi recently a program has been started for the measurement of fusion barrier through quasi-elastic scattering methods. The experimental facility and the first results of the experiments carried out with this facility are presented. (author)

  18. Interference between direct and indirect modes in two-nucleon transfer reactions with heavy ions

    International Nuclear Information System (INIS)

    Scott, D.K.; Harvey, B.G.; Hendrie, D.L.; Jahnke, U.; Kraus, L.; Maguire, C.F.; Mahoney, J.; Terrien, Y.; Yagi, K.; Glendenning, N.K.

    1975-01-01

    Direct and indirect transitions to the lowest 2 + collective states are shown to interfere constructively in the pickup reaction 122 Sn( 16 O, 18 O) 120 Sn at 104 MeV, and destructively in the inverse stripping reaction 120 Sn( 18 O, 16 O) 122 Sn at 99 MeV

  19. The circular polarization of gamma rays from heavy-ion reactions high above the Coulomb barrier

    International Nuclear Information System (INIS)

    Lauterbach, C.; Boer, J. de; Duennweber, W.; Graw, G.; Hering, W.; Puchta, H.; Trautmann, W.

    1978-01-01

    We have measured the circular polarization P of the γ radiation emitted in coincidence with the projectile-like fragments from the 100 MeV 16 O+ 27 Al, 58 Ni reactions at the Munich MP tandem accelerator and the 284 (303) Mev 40 Ar+Ag and 539 MeV 86 Kr+Ag reactions at the GSI UNILAC. (orig.) [de

  20. Nuclear research with heavy ions

    International Nuclear Information System (INIS)

    Kaplan, M.

    1991-08-01

    This report discusses the following topics: Asymmetric fission of 149 Tb* from the finite-range, rotating-liquid-drop model: mean total kinetic energies for binary fragmentation; charged-particle evaporation from hot composite nuclei: evidence over a broad Z range for distortions from cold nuclear profiles; the role of reversed kinematics and double kinematic solutions in nuclear reactions studies; production of intermediate-mass-fragments in the reaction 98 Mo + 51 V at an excitation energy E* = 224-MeV; emission of light charged particles in the reaction 344-MeV 28 Si + 121 Sb; continued developments of the statistical evaporation code LILITA N90; and planning for heavy-ion-collision studies at very high energies: the STAR collaboration at RHIC

  1. 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, 141980 Dubna (Russian Federation); Yerevan State University, 0025 Yerevan (Armenia); Adamian, G. G., E-mail: adamian@theor.jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Antonenko, N. V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Mathematical Physics Department, Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Diaz-Torres, A. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas, I-38123 Villazzano, Trento (Italy); Gomes, P. R. S. [de Fisica, Universidade Federal Fluminense, Av. Litorânea, s/n, Niterói, R.J. 24210-340 (Brazil); Lenske, H. [Institut für Theoretische Physik der Justus–Liebig–Universität, D–35392 Giessen (Germany)

    2016-07-07

    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.

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

    International Nuclear Information System (INIS)

    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

  3. Compound nuclei, binary decay, and multifragmentation in intermediate-energy heavy-ion reactions

    International Nuclear Information System (INIS)

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

    1988-07-01

    Hot compound nuclei, frequently produced in intermediate-energy reactions through a variety of processes, are shown to be an important and at times dominant source of complex fragments. 13 refs., 12 figs

  4. Transfer reactions with very heavy ions. Quarterly report 3. quarter 1987

    International Nuclear Information System (INIS)

    Juutinen, Sakari.

    1988-03-01

    This thesis deals with the reaction mechanism of the few-nucleon transfer reactions between the 58 Ni projectiles and the Dy targets. A series of transfer experiments utilizing the particle-γ coincidence technique was performed. Particle detection was used to give the scattering angles of two reaction products and the reaction channel was selected by the discrete γ-rays in the Ge detectors. Total γ-ray energy and multiplicity distributions were measured by the Spin Spectrometer. Total γ-ray energy and multiplicity distributions, γ-ray spectra obtained by the Ge and NaI detectors and angular distributions of the projectile-like ions are discussed. For one- and two-neutron transfer the experimental results provide direct evidence of a cold mechanism populating high-spin states near the yrast line. A schematic model for the transfer mechanism is proposed. This model accounts for the prominent features of one- and two-neutron pickup

  5. Double-differential heavy-ion production cross sections

    International Nuclear Information System (INIS)

    Miller, T. M.; Townsend, L. W.

    2004-01-01

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

  6. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    Science.gov (United States)

    Oganessian, Yu. Ts.; Shchepunov, V. A.; Dmitriev, S. N.; Itkis, M. G.; Gulbekyan, G. G.; Khabarov, M. V.; Bekhterev, V. V.; Bogomolov, S. L.; Efremov, A. A.; Pashenko, S. V.; Stepantsov, S. V.; Yeremin, A. V.; Yavor, M. I.; Kalimov, A. G.

    2003-05-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10 -3. The set up can work in the wide mass range from A≈20 to A≈500, its mass acceptance is as large as ±2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90° electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considered. Description of its elements and subsystems is given.

  7. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    CERN Document Server

    Oganessian, Yu T; Dmitriev, S N; Itkis, M G; Gulbekyan, G G; Khabarov, M V; Bekhterev, V V; Bogomolov, S L; Efremov, A A; Pashenko, S V; Stepantsov, S V; Yeremin, A V; Yavor, M I; Kalimov, A G

    2003-01-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10 sup - sup 3. The set up can work in the wide mass range from A approx 20 to A approx 500, its mass acceptance is as large as +-2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90 deg. electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considere...

  8. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    International Nuclear Information System (INIS)

    Oganessian, Yu.Ts.; Shchepunov, V.A.; Dmitriev, S.N.; Itkis, M.G.; Gulbekyan, G.G.; Khabarov, M.V.; Bekhterev, V.V.; Bogomolov, S.L.; Efremov, A.A.; Pashenko, S.V.; Stepantsov, S.V.; Yeremin, A.V.; Yavor, M.I.; Kalimov, A.G.

    2003-01-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10 -3 . The set up can work in the wide mass range from A∼20 to A∼500, its mass acceptance is as large as ±2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90 deg. electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considered. Description of its elements and subsystems is given

  9. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    Energy Technology Data Exchange (ETDEWEB)

    Oganessian, Yu.Ts.; Shchepunov, V.A. E-mail: shchepun@sunhe.jinr.rushchepun@cv.jinr.ru; Dmitriev, S.N.; Itkis, M.G.; Gulbekyan, G.G.; Khabarov, M.V.; Bekhterev, V.V.; Bogomolov, S.L.; Efremov, A.A.; Pashenko, S.V.; Stepantsov, S.V.; Yeremin, A.V.; Yavor, M.I.; Kalimov, A.G

    2003-05-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10{sup -3}. The set up can work in the wide mass range from A{approx}20 to A{approx}500, its mass acceptance is as large as {+-}2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90 deg. electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considered. Description of its elements and subsystems is given.

  10. Heavy Ion Physics at LHC

    CERN Document Server

    Valenti, G.

    2002-01-01

    The study of heavy ion interactions constitutes an important part of the experimental program outlined for the Large Hadron Collider under construction at CERN and expected to be operational by 2006. ALICE 1 is the single detector having the capabilities to explore at the same time most of the characteristics of high energy heavy ion interactions. Specific studies of jet quenching and quarkonia production, essentially related to µ detection are also planned by CMS 2 .

  11. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Fessenden, T.J.; Friedman, A.

    1991-01-01

    This report describes the research status in the following areas of research in the field of heavy ion inertial fusion: (1) RF accelerators, storage rings, and synchrotrons; (2) induction linacs; (3) recirculation induction accelerator approach; (4) a new accelerator concept, the ''Mirrortron''; (5) general issues of transport, including beam merging, production of short, fat quadrupoles with nearly linear focusing, calculations of beam behaviour in image fields; 3-D electrostatic codes on drift compression with misalignments and transport around bends; (6) injectors, ion sources and RFQs, a.o., on the development of a 27 MHz RFQ to be used for the low energy portion of a new injector for all ions up to Uranium, and the development of a 2 MV carbon ion injector to provide 16 C + beams of 0.5 A each for ILSE; (7) beam transport from accelerator to target, reporting, a.o., the feasibility to suppress third-order aberrations; while Particle-in-Cell simulations on the propagation of a non-neutral ion beam in a low density gas identified photo-ionization by thermal X-rays from the target as an important source of defocusing; (9) heavy ion target studies; (10) reviewing experience with laser drivers; (11) ion cluster stopping and muon catalyzed fusion; (12) heavy ion systems, including the option of a fusion-fission burner. 1 tab

  12. Studies of Limits on Uncontrolled Heavy Ion Beam Losses for Allowing Hands-On Maintenance. Final report

    International Nuclear Information System (INIS)

    Ronningen, Reginald M.; Remec, Igor

    2010-01-01

    Dose rates from accelerator components activated by 1 W/m beam losses are obtained semiempirically for a 1 GeV proton beam and by use of Monte Carlo transport codes for the proton beam and for 777 MeV/u 3He, 500 MeV/u 48Ca, 86Kr, 136Xe, and 400 MeV/u 238U ions. The dose rate obtained by the semi-empirical method, 0.99 mSv/h (99 mrem/h) at 30 cm, 4 h after 100 d irradiation by a 1-GeV proton beam, is consistent with studies at several accelerator facilities and with adopted hands-on maintenance dose rate limits. Monte Carlo simulations verify this result for protons and extend studies to heavy ion beam losses in drift-tube linac and superconducting linac accelerating structures. The studies indicate that the 1 W/m limit imposed on uncontrolled beam losses for high-energy proton beams might be relaxed for heavy ion beams. These studies further suggest that using the ratio of neutrons produced by a heavy ion beam to neutrons produced by a proton beam along with the dose rate from the proton beam (for thin-target scenarios) should allow an estimate of the dose rates expected from heavy ion beam losses.

  13. CHICSi - a 3π multi-detector system for studying heavy ion interactions inside a storage ring

    International Nuclear Information System (INIS)

    Avdeichikov, V.; Carlen, L.; Fokin, A.; Jakobsson, J.; Murin, Yu.; Maartensson, J.; Oskarsson, A.; van Veldhuizen, E.J.; Westerberg, L.; Whitlow, H.J.

    1996-01-01

    CHICSi - a 3π multi-detector system is presented. The setup consists of 576 ultra high vacuum compatible telescopes to study intermediate energy heavy ion as well as proton induced collisions at storage rings operating in slow ramping mode. Primary it will be installed at the gas-jet target station of the CELSIUS facility at The Svedberg Laboratory in Uppsala. (orig.)

  14. Alpha-particle energy spectra measured at forward angles in heavy-ion-induced reactions

    International Nuclear Information System (INIS)

    Borcea, C.; Cierlic, E.; Kalpakchieva, R.; Oganessian, Yu.Ts.; Penionzhkevich, Yu.E.

    1980-01-01

    Energy spectra have been measured for α-particles emitted in the bombardment of 159 Tb, 181 Ta, 197 Au, and 232 Th nuclei by 20 Ne, 22 Ne, and 40 Ar projectiles. The reaction products emitted in the angular range (0+-2)deg relative to the beam direction were analyzed using a magnetic spectrometer and detected by means of a semiconductor ΔE-E telescope. It was found that in all cases the experimentally measured maximum α-particle energy almost amounts to the maximum possible value calculated from the reaction energy balance for a two-body exit channel. A correlation was found between the measured absolute cross section in different target-projectile combinations and the α-particle binding energy in the target nuclei. On the basis of the obtained results a conclusion has been drawn that the α-particles are emitted in the early stage of the reaction

  15. Oriented heavy ions and the choice of a cool compound nucleus reaction

    International Nuclear Information System (INIS)

    Aroumougame, R.; Gupta, R.K.

    1980-01-01

    Potential energy surfaces are calculated within the mechanism of fragmentation theory with a view to selecting the target-projectile combinations for producing new elements through cool compound nucleus formation. The orientation of the colliding nuclei is also included. It is shown that both the reaction partners of a cool compound nucleus, formed in either a central or a nearly central collision, should preferably be spherical and either nearly symmetric or extremely asymmetric. For reactions with deformed nuclei, it is suggested that polarised targets should be used. The calculations are illustrated for the compound nuclei 258 104 and 260 106. (author)

  16. Ptolemy: a program for heavy-ion direct-reaction calculations

    International Nuclear Information System (INIS)

    Macfarlane, M.H.; Pieper, S.C.

    1978-04-01

    Ptolemy is an IBM/360 program for the computation of nuclear elastic and direct-reaction cross sections. It carries out optical-model fits to elastic-scattering data at one or more energies and for one or more combinations of projectile and target, collective model DWBA calculations of excitation processes, and finite-range DWBA calculations of nucleon-transfer reactions. It is fast and does not require large amounts of core. The input is exceptionally flexible and easy to use. The types of calculations that Ptolemy can carry out are outlined, the formulas used are summarized, and a detailed description of its input is given

  17. Dynamical limitations to heavy-ion fusion

    International Nuclear Information System (INIS)

    Back, B.B.

    1983-01-01

    In spite of the many attempts to synthesize superheavy elements in recent years, these efforts have not yet been successful. Recent improved theoretical models of heavy-ion fusion reactions suggest that the formation of super-heavy elements is hindered by the dynamics of the process. Several recent experiments lend support to these theories. The necessity of an excess radial velocity (extra push) over the Coulomb barrier in order to induce fusion is observed experimentally as predicted by the theory. So is a new reaction mechanism, called quasi-fission which tend to exhaust the part of the reaction cross section, which would otherwise lead to fusion. The present study shows that the angular distribution of fragments from quasi-fission processes are very sensitive to the occurrence of this reaction mechanism. A slight modification of one parameter in the theory demanded by the observation of quasi-fission for lighter projectiles via the angular distributions, has the consequence of posing even more-stringent limitations on heavy-ion-fusion reactions. This reduces even further the possibility for synthesizing and identifying superheavy elements in heavy-ion-fusion reactions

  18. Studies on the dynamics of heavy ion collisions at intermediate energies

    International Nuclear Information System (INIS)

    David, C.; Hartnack, C; Aichelin, J.

    1997-01-01

    We use the Quantum Molecular Dynamics model for the investigation of the dynamics of heavy ion collisions at intermediate energies. A detailed comparison between different versions of the models demonstrate the influence of not exactly known parameters in the description of nuclei like interaction range or initial densities and thus describes the limits of predictive power. The dynamics of the reaction are discussed quite similarly in the different models. A radial expansion with a linear velocity profile is found at central collisions. A strong interaction of pions with nuclear matter is reported. This interaction is strongly influenced by the lifetime of baryonic resonances in nuclear matter. These lifetimes depend strongly on the mass distribution of the resonances. These mass distributions are influenced by the momentum distribution in the nuclei. Here the inclusion of the spectral function shows visible effects. These effects influence the energy dissipation in nuclei and thus enter e.g. into the analysis of p + A collisions for the GEDEON project. (author)

  19. Role of transfer reactions in heavy-ion collisions at the Coulomb barrier

    Directory of Open Access Journals (Sweden)

    Pollarolo Giovanni

    2011-10-01

    Full Text Available One and two neutron transfer reactions are discussed in the semiclassical formalism. The twoneutrons transfer cross sections are calculated in the successive approximation. Comparisons with new experimental data below the Coulomb barrier are discussed in term of transfer probabilities as a function of the distance of closest approach for Coulomb scattering.

  20. Regge parametrization of angular distributions for heavy-ion transfer reactions

    International Nuclear Information System (INIS)

    Carlson, B.V.; McVoy, K.W.

    1977-01-01

    A two-pole one-zero Regge parametrization of the l-window for transfer reactions is employed in conjunction with a chi-squared search program to obtain high-quality fits to a wide variety of transfer data. The data employed include both direct and multi-step transfers. (Auth.)

  1. Collinear laser spectroscopy on In isotopes from heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Ulm, G.

    1984-07-01

    Indium isotopes 107-111 were produced by 16 O-fusion reactions and investigated in a collinear laser geometry. The hyperfine structure and isotopic shifts are measured and the deduced magnetic dipole moments are in agreement with shell model calculations. The nuclear charge radii are determined from the isotopic shifts. (WL)

  2. A new closed form expression for the total reaction cross-section of heavy ions

    International Nuclear Information System (INIS)

    Rego, R.A.; Hussein, M.S.

    1989-02-01

    A new analytical expression for the HI total reaction cross-section which exhibits the macroscopic features of the transparency factor is derived. Comparison with optical model calculation are made for the 12 C+ 208 Pb and 16 O + 208 Pb at several energies. (author)

  3. 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.

  4. Light particle emission measurements in heavy ion reactions: Progress report, June 1, 1986-May 31, 1987

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1987-01-01

    During the past year we have completed our work on neutron emission in coincidence with fission fragments from the 158 Er system. In addition to this we have completed preliminary analysis of our results on neutron emission from products of damped reactions between 58 Ni and 165 Ho at 930 MeV. Two experiments were planned for the present contract period as discussed in our proposal for 1986-87. One of these, to measure the mass and charge distributions from projectile-like fragments (PLF) in the reactions 58 Ni + 165 Ho and 58 Ni + 58 Ni using the time-of-flight facility at the HHIRF has been successfully completed. The other, to measure momentum correlations between neutrons and charged particles produced in central collisions between 32 S + 197 Au is scheduled to be run in mid-February. 14 refs., 4 figs

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

    International Nuclear Information System (INIS)

    Cardella, G.; Acosta, L.; Auditore, L.

    2016-01-01

    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.

  6. A search for collective pion production in 2 GeV/Nucleon heavy ion reactions

    International Nuclear Information System (INIS)

    Jakobsson, B.; Kullberg, R.; Otterlund, I.; Ruiz, A.; Bolta, J.M.; Higon, E.

    1977-10-01

    he π(+-) multiplicity distributions in 12 C and 16 O induced reactions in nuclear emulsion at 2 GeV/nucleon have been measured. The results are compared to a model in which we assume that only independent nucleon-nucleon scattering occurs. Such a model can explain the complete π(+-) multiplicity spectra, only if we assume a very limited shadow effect, i.e. very few nucleons must be swept out of the nuclei during the time of overlap. (author)

  7. Evidence for the characterization of heavy-ion reactions by the ratio E/B

    International Nuclear Information System (INIS)

    Mathews, G.J.; Wozniak, G.J.; Schmitt, R.P.; Moretto, L.G.

    1977-01-01

    The connection between the characteristic features of reactions involving very heavy target-projectile combinations (e.g. 86 Kr + 197 Au) and lighter systems (e.g. 40 Ar + sup(nat)Ag) is discussed. Evidence for an impirical scaling law based upon the ratio E/B (center-of-mass kinetic energy to Coulomb barrier) is presented. This scaling is justified in terms of semiquantitative arguments whereby the different charge and angular distribution patterns from light and heavy target-projectile combinations are correlated with different lifetime regimes for the 'intermediate complex' as it diffuses along the mass-asymmetry coordinate. (orig.) [de

  8. Transition probabilities of 36Cl and 36Ar excited states in heavy ion reactions

    International Nuclear Information System (INIS)

    Costa, G.J.; Alexander, T.K.; Forster, J.S.; McDonald, A.B.; Towner, I.S.

    The reactions 2 H( 35 Cl,pγ) and 2 H( 35 Cl,nγ) have been used to determine by the recoil-distance method, the lifetimes of levels in 36 Cl and 36 Ar respectively. Large discrepancies exist in the literature for some lifetimes of 36 Cl levels. Transition rates found for decay of the negative parity states in 36 Ar (4178 (3 - ), 4974 (2 - ) and 5171 (5 - ) keV), are compared whith the Maripuu-Hokken model and RPA and TDA predictions [fr

  9. Differential cross section study of fragment production, at small angle, in relativistic heavy ion collisions. Application at a calculation of heavy ion beam transport in the matter

    International Nuclear Information System (INIS)

    Morel, P.

    1992-02-01

    Relativistic heavy ion collisions present the opportunity of creating in laboratory small volumes of hot, dense nuclear matter. On the experimental point of view, the collision events are characterized by a great number of fragments, especially in the direction of the projectile. The first part is devoted to a survey of relativistic heavy ion physics. Then, we present two experimental set-ups which permit, in particular, the analyse of light fragment production at small angles. We present experimental results concerning light projectiles on Ca, Nb, Pb targets, with energies from 200 A.MeV up to 600 A.MeV. Different aspects of the collision are put in evidence. Momentum and charge differential cross section are extrapolated to other projectile/target systems; that is used in a transport calculation of Ne ions in a target of biological interest (water), with a collimator. We show that nuclear fragmentation produces a dispersion in the spatial and energy distributions, and that one light fragments have a range greater than the projectile range. That last point causes a distortion of the Bragg curve, and that distortion must be taken into account for the application of heavy ions to radiotherapy problems. 95 figs., 8 tabs

  10. 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.)

  11. Roles of multi-step transfer in fusion process induced by heavy-ion reactions

    International Nuclear Information System (INIS)

    Imanishi, B.; Oertzen, W. von.

    1993-06-01

    In nucleus-nucleus collisions of the systems, 12 C+ 13 C and 13 C+ 16 O- 12 C+ 17 O, the effects of the multi-step transfers and inelastic excitations on the fusion cross sections are investigated in the framework of the coupled-reaction-channel (CRC) method. Strong CRC effects of the multi-step processes are observed. Namely, the valence neutron in 13 C or 17 O plays an important role in the enhancement of the fusion. The potential barrier is effectively lowered with the formation of the covalent molecule of the configuration, 12 C+n+ 12 C or 12 C+n+ 16 O. In the analyses of the system 12 C+ 13 C, however, it is still required to introduce core-core optical potential of lower barrier height in the state of the positive total parity. This could be due to the neck formation with the nucleons contained in two core nuclei. (author)

  12. Microscopic calculation of friction coefficients for use in heavy-ion reaction

    International Nuclear Information System (INIS)

    Iwamoto, A.; Harada, K.; Yoshida, S.

    1981-01-01

    A microscopic calculation has been done for the friction coefficient for use in the deep-inelastic collision of heavy nuclei. We adopted the formalism of the linear response theory as a basis and used the adiabatic base of the two-center shell model. Several reaction channels with the total mass numbers of 236 and 260 systems were investigated. The friction coefficients for the radial and deforming motions including the coupling term were calculated as a function of the distance between two nuclei and deformation of the two nuclei for each channel. The general feature of the friction coefficient, its strength and form factor, was clarified in this model and comparison with the results of other models were done. It was found that our model gives a physically plausible value for the friction coefficient as a whole. (orig.)

  13. Using MASHA+TIMEPIX Setup for Registration Beta Decay Isotopes Produced in Heavy Ion Induced Reactions

    Science.gov (United States)

    Rodin, A. M.; Belozerov, A. V.; Chernysheva, E. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Itkis, M. G.; Novoselov, A. S.; Oganessian, Yu. Ts.; Salamatin, V. S.; Stepantsov, S. V.; Vedeneev, V. Yu.; Yukhimchuk, S. A.; Krupa, L.; Granja, C.; Pospisil, S.; Kliman, J.; Motycak, S.; Sivacek, I.

    2015-06-01

    Radon and mercury isotopes were produced in multi nucleon transfer (48Ca + 232Th) and complete fusion (48Ca + naturalNd) reactions, respectively. The isotopes with given masses were detected using two detectors: a multi-strip detector of the well-type (made in CANBERRA) and a position-sensitive quantum counting hybrid pixel detector of the TIMEPIX type. The isotopes implanted into the detectors then emit alpha- and betaparticles until reaching the long lived isotopes. The position of the isotopes, the tracks, the time and energy of beta-particles were measured and analyzed. A new software for the particle recognition and data analysis of experimental results was developed and used. It was shown that MASHA+ TIMEPIX setup is a powerful instrument for investigation of neutron-rich isotopes far from stability limits.

  14. Salient features of heavy ion reactions in the intermediate energy region

    International Nuclear Information System (INIS)

    Jakobsson, B.

    1987-01-01

    In this lecture the attention is focused on the most central and therefore generally also the most violent collisions. It is necessary to remember that the non-participating volumes could be very different for symmetric and asymmetric reactions. The onset of the multifragmentation channel or rather the cease of the fusion process is the first topic to be discussed. This question is directly related to the limitation in energy and momentum transfer and thus to the question about nuclear transparency. Exclusive data on multifragmentation on an event-by-event basis, which may help the model constructors, is presented as the second topic. In lecture the onset of fragmentation, fragment sizes in multifragmentation processes, the origin of light particle correlations and emission of pions and kaons close to the threshold are discussed

  15. 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.

  16. Production study of light fragments emitted at low angle in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Bastid, N.

    1987-03-01

    The Diogene plastic wall was built in order to study fragment production in a 0 O -6 O angular range. After generalities on heavy ion collisions and a description of the Diogene detector, methods used for data analysis allowing identification of charged particles and measurement of their energy and emission angle are presented. From correlation studies between the Diogene events and the plastic wall events, we can have an information on the centrality of collisions. On the other hand, the study of differential cross sections shows two existing sources: one formed by the projectile remnant, at a velocity close to beam velocity and a source of intermediary rapidity formed by the participants. We have shown that even for very central collisions and heavy targets, the target nucleus remains partially transparent. In order to explain projectile fragmentation mechanism, we have used two models: a coalescence model and a thermal model. The first model gives the value of the coalescence radius. It seems that this model does not apply to angles nearing 0 O . With the thermal model, we have been able to sort out apparent temperature values which confirm the weak excitation energy of the projectile remnant [fr

  17. Design studies of heavy ion linear accelerators constructed of independently phased spiral resonators

    International Nuclear Information System (INIS)

    Stokes, R.H.; Armstrong, D.D.

    1975-01-01

    Preliminary design studies are reported for two linear accelerators for heavy ions. One accelerator is a high-intensity machine which would operate with 100 percent duty factor and would produce tin ions with 6.1 MeV/A. Alternatively, it could be operated under pulsed conditions with 25 percent duty factor and would then accelerate uranium ions to 8.1 MeV/A, tin ions to 10.5 MeV/A, and all lighter ions to higher velocities. It would be injected with a positive multicharge ion source and a 4-MV single-ended dc generator. Also, design studies are reported for small postaccelerator injected by a model FN tandem. Both accelerators use three-drift-tube spiral resonators operating at room temperature. Magnetic quadrupole singlets are placed between all resonators to provide radial focussing. Each resonator is independently phased according to the velocity of the ion to be accelerated. The ability to adjust the phase of each resonator permits variations in final energy and other beam properties with great flexibility. (U.S.)

  18. Systematic studies of heavy ion collisions in the low SIS energy region

    International Nuclear Information System (INIS)

    Li Qingfeng; Wang Yongjia; Guo Chenchen; Li Zhuxia

    2014-01-01

    After inserting the Skyrme potential energy density functions for potential update, more detailed medium modifications for nucleon-nucleon elastic cross sections, and the isospin effect for cluster recognition into the Ultra-relativistic Quantum Molecular Dynamics (UrQMD), the dynamic process of heavy ion collisions (HICs) at low SIS energies (about 40∼400 MeV/u) is primarily studied. And, after systematically studying the emission and collective flows of light clusters from HICs in such beam energy region, the sensitive observables especially to the density dependent symmetry energy at supra-normal densities are focused. It is found that: (1)the initial neutron/proton ratio dependence of the balance energy of neutrons from mass-symmetric Sn isotopes can be taken as a useful probe to constrain the stiffness of the nuclear symmetry energy; (2) the transverse velocity/momentum dependence of the elliptic flow ratio of neutrons and protons or hydrogen isotopes (v 2 n /v 2 p,H ) is also sensitive to symmetry energy. The χ 2 analysis from the difference bet e the theoretical (taking Skyrme potential parametrizations with incompressibility K 0 being almost same but the slope parameter L of symmetry energy being largely different) and experimental (taking FOPI/LAND data) v 2 n /v 2 H values determines the value of L to be (89 ± 45) MeV within in a 2σ uncertainty. (authors)

  19. Coupled channels effects in heavy ion elastic scattering

    International Nuclear Information System (INIS)

    Bond, P.D.

    1977-01-01

    The effects of inelastic excitation on the elastic scattering of heavy ions are considered within a coupled channels framework. Both Coulomb and nuclear excitation results are applied to 18 O + 184 W and other heavy ion reactions

  20. The European FAZIA initiative: a high-performance digital telescope array for heavy-ion studies

    International Nuclear Information System (INIS)

    Casini, G.; Barlini, S.; Pasquali, G.; Pastore, G.; Bini, M.; Carboni, S.; Olmi, A.; Piantelli, S.; Poggi, G.; Stefanini, A.; Valdre, S.; Bonnet, E.; Chbihi, A.; Frankland, J.D.; Gruyer, D.; Marini, P.; Borderie, B.; Edelbruck, P.; Rivet, M.F.; Salomon, F.; Bougault, R.; Le Neindre, N.; Lopez, O.; Parlog, M.; Vient, E.; Bruno, M.; Guerzoni, M.; Morelli, L.; Cinausero, M.; Gramegna, F.; Degerlier, M.; Kordjasz, A.; Twarog, T.; Kozik, T.; Marchi, T.; Ordine, A.; Rosato, E.; Spadaccini, G.; Vigilante, M.

    2014-01-01

    A modular array of 192 Si-Si-CsI(Tl) telescopes is under construction by the european FAZIA collaboration for charged product identification in heavy-ion studies. Thanks to an intense development phase, the ion identification capability of such modules has been improved both adopting specific solutions for the detectors and using fast digital electronics channels featuring high resolution. The silicons have been cut to present almost random orientation and have uniform doping homogeneity. To improve pulse shape analysis (PSA), they are reverse mounted in the telescopes. Full charge separation has been obtained up to over Z=54 also for ions stopping in the first silicon layer via PSA, with a threshold of 2.5 MeV/u for Carbon (Tin) ions. Isotopes are separated up to the iron region by the ΔE - E method for ions stopped in second silicon or in the CsI crystal. For slower particles, the PSA allows for isotopic resolution up to Z ∼ 14 with thresholds corresponding to ∼ 50 μm of (fully depleted) silicon detector. Preliminary results for partially depleted detectors indicate a strong improvement of mass separation with respect to the full depletion case at the cost of somewhat higher thresholds

  1. Low-emittance uniform density Cs+ sources for heavy ion fusion accelerators studies

    International Nuclear Information System (INIS)

    Eylon, S.; Henestroza, E.; Garvey, T.; Johnson, R.; Chupp, W.

    1991-04-01

    Low-emittance (high-brightness) Cs + thermionic sources were developed for the heavy ion induction linac experiment MBE-4 at LBL. The MBE-4 linac accelerates four 10 mA beams from 200 ke V to 900 ke V while amplifying the current up to a factor of nine. Recent studies of the transverse beam dynamics suggested that characteristics of the injector geometry were contributing to the normalized transverse emissions growth. Phase-space and current density distribution measurements of the beam extracted from the injector revealed overfocusing of the outermost rays causing a hollow density profile. We shall report on the performance of a 5 mA scraped beam source (which eliminates the outermost beam rays in the diode) and on the design of an improved 10 mA source. The new source is based on EGUN calculations which indicated that a beam with good emissions and uniform current density could be obtained by modifying the cathode Pierce electrodes and using a spherical emitting surface. The measurements of the beam current density profile on a test stand were found to be in agreement with the numerical simulations. 3 refs., 6 figs

  2. Review of Heavy-ion Induced Desorption Studies for Particle Accelerators

    CERN Document Server

    Mahner, E

    2008-01-01

    During high-intensity heavy-ion operation of several particle accelerators worldwide, large dynamic pressure rises of orders of magnitude were caused by lost beam ions that impacted under grazing angle onto the vacuum chamber walls. This ion-induced desorption, observed, for example, at CERN, GSI, and BNL, can seriously limit the ion intensity, luminosity, and beam lifetime of the accelerator. For the heavyion program at CERN's Large Hadron Collider collisions between beams of fully stripped lead (208Pb82+) ions with a beam energy of 2.76 TeV/u and a nominal luminosity of 10**27 cm**-2 s**-1 are foreseen. The GSI future project FAIR (Facility for Antiproton and Ion Research) aims at a beam intensity of 10**12 uranium (238U28+) ions per second to be extracted from the synchrotron SIS18. Over the past years an experimental effort has been made to study the observed dynamic vacuum degradations, which are important to understand and overcome for present and future particle accelerators. The paper reviews the resu...

  3. 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...

  4. Limiting fragmentation, scaling and substructual dependence of multiparticle production in high energy heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Otterlund, I; Garpman, S; Persson, S; Soderstrom, K; Stenlund, E [Lund Univ. (Sweden); Adamovich, M I; Alexandrov, Y A; Chernyavsky, M M; Gerassimov, S G; Kharlamov, S P; Larionova, V G; Maslennikova, N V; Orlova, G I; Peresadko, N G; Salmanova, N A; Tretyakova, M I [AN SSSR, Moscow. Fizicheskij Inst. (USSR); Aggarwal, M M; Friedlander, E M; Heckman, H H; Lindstrom, P J [Lawrence Berkeley Lab., CA (USA); Andreeva, N P; Anson, Z V; Ameeva, Z V; Bubnov, V I; Chasnicov, I Y; Eremenko, L E; Eligbaeva, G Z; Gaitinov, A S; Kalyachkina, G S; Kanygina, E K; Shakhova, T I [AN Kazakhskoj SSR, Alma-Ata. Inst. Fiziki Vysokikh Ehnergij (USSR); Arora, R; Bhatia, V S; Kaur, M; Mittra, I S [Panjab Univ., Chandigarh (India); Azimov, S A; Chernova, L P; Gadzhieva, S I; Gulamov, K G; Kadyrov, F G; Lukicheva, N S; Navotny, V S; Svechnikova, L N [AN Uzbekskoj SSR, Tashkent. Fiziko-Tekhnicheskij Inst. (USSR); Basova, E; Bondarenko, R A; Gulyamov, U G; EMUO1 Collaboration

    1990-01-01

    We report on recent results obtained by the EMUO1 collaboration from studies of {sup 16}O + emulsion, at 14.6, 60 and 200 A GeV, and {sup 32}S + emulsion and {sup 32}S+Au interactions at 200 A GeV. Shower-particle production in oxygen-induced interactions are studied over the energy range 2.1-200 A GeV. Scaling and limiting fragmentation are observed. Multiplicity and angular distributions of low energy target-associated particles are presented and compared with distributions obtained using the Ranft and the Fritiof simulation codes. (orig.).

  5. [Light particle emission in heavy ion reactions.] Progress report for 1994--1995

    International Nuclear Information System (INIS)

    Howell, E.H.; He, Xiaochun; Petitt, G.A.; Zhang, Ziyang.

    1995-01-01

    This report discusses the following topics: PHENIX RD94 R ampersand D: PISA/PISORP code development; level-1 trigger rate simulation study for PHENIX muon arm; μ/τ discrimination performance of PHENIX muon arm; and μ/τ discrimination performance of RD45 calorimeter

  6. Studies of complex fragment emission in heavy ion reactions

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  7. Large Acceptance Measurement of Photons and Charged Particles in Heavy Ion Reactions

    CERN Multimedia

    2002-01-01

    % WA98 \\\\ \\\\ The aim of the experiment is the high statistics study of photons and neutral hadrons, as well as of charged particles, and their correlations in Pb~-~Pb collisions. The photons are measured by: \\begin{enumerate}[-] \\item a 10~000 module LEADGLASS SPECTROMETER yielding high precision data on $ \\pi ^0 $ and $ \\eta $ at midrapidity (with transverse momenta 0.3 GeV/c $>$ p$ _{T} $ $>$ 4.5 GeV/c for $\\pi ^0 $ and 1.5~GeV/c~$>$~p$ _{T}~$ $>$~4.0~GeV/c for $ \\eta $ covering the $^{\\prime\\prime}$thermal$^{\\prime\\prime}$ as well as the $^{\\prime\\prime}$hard scattering$^{\\prime\\prime}$ regime beyond 3~GeV/c) and determination of the thermal and direct photon to $ \\pi ^0 $ ratio. \\item a pad preshower PHOTON MULTIPLICITY DETECTOR which, by comparing with the charged particle multiplicity measurement allows to determine the photon enrichment in an event or event class. \\end{enumerate}\\\\ \\\\The charged particle setup contains:\\\\ \\\\\\begin{enumerate}[-] \\item a 4000 element SILICON PAD DETECTOR and a 4-inch SIL...

  8. Theoretical study of cylindrical energy analyzers for MeV range heavy ion beam probes

    International Nuclear Information System (INIS)

    Fujisawa, A.; Hamada, Y.

    1993-07-01

    A cylindrical energy analyzer with drift spaces is shown to have a second order focusing for beam incident angle when the deflection angle is properly chosen. The analyzer has a possibility to be applied to MeV range heavy ion beam probes, and will be also available for accurate particle energy measurements in many other fields. (author)

  9. Experimental study of the slowing down of heavy ions at 20 to 100 MeV per nucleon in matter

    International Nuclear Information System (INIS)

    Herault, J.

    1988-01-01

    The measurements of typical parameters on heavy ions penetration through matter presented in this work have been performed at the GANIL accelerator facility, using the LISE magnetic spectrometer from 20 to 100 MeV per nucleon. Two magnetic optical configurations of the spectrometer LISE corresponding respectively to energy and angle analysis, have been used. In the first configuration, the analysis of the energy loss distribution, caused by the interaction of the heavy ions beam with the target material, permit to determine the stopping power and the energy straggling. The stopping power is defined experimentally by the ratio of the average energy loss in the target to the thickness of this one. This quantity has been measured for a set of heavy ions ( 17 O, 40 Ar, 86 Kr and 132 Xe) in gaseous media (H 2 , He, N 2 , Ne, Ar, Kr, Xe, CH 4 , C 4 H 10 , CO 2 and CF 4 ) and compared to semi-empirical tabulations. These determinations are compared to those obtained in solid media to study the evolution of the solid-gas difference. This effect vanishes progressively when the projectile tends to be totally stripped (the charge state becomes identical to the atomic number). The heavy ion energy distributions at the exit of degraders and particularly their full width at half maximum have been measured for various projectiles ( 16 O, 40 Ar, 84 Kr, 86 Kr, 100 Mo and 132 Xe) in solid (Be, C, Al, Si, Ti, Ni, Cu, Ag, Ta, Au and Mylar) and gaseous media (the same as for stopping power determinations). A significant contribution of charge exchange straggling to the energy loss straggling is observed for partially stripped ions. A second optical configuration of the beam line LISE has been used, to obtain an image of heavy ions beams passing through targets for various heavy ions ( 16 O, 17 O, 40 Ar, 86 Kr and 100 Mo) in gaseous and solid media. The scaling law for angular straggling is confirmed and extended over five orders of magnitude [fr

  10. Heavy ion medical accelerator, HIMAC

    International Nuclear Information System (INIS)

    Yamada, Satoru

    1993-01-01

    The heavy ion beam is undoutedly suitable for the cancer treatment. The supriority of the heavy ions over the conventional radiations including protons and neutrons comes mainly from physical characteristics of a heavy particle with multiple charges. A straggling angle due to a multiple Coulomb scattering process in a human body is small for heavy ions, and the small scattering angle results in a good dose localization in a transverse direction. An ionization ratio of the heavy ion beam makes a very sharp peak at the ends of their range. The height of the peak is higher for the heavier ions and shows excellent biomedical effects around Ne ions. In order to apply heavy ion beams to cancer treatment, Heavy Ion Medical Accelerator in Chiba (HIMAC) has been constructed at National Institute of Radiological Sciences. The accelerator complex consists of two ion sources, two successive linac tanks, a pair of synchrotron rings, a beam transport system and an irradiation system. An operation frequency is 100 MHz for two linacs, and the ion energy is 6.0 MeV/u at the output end of the linac. The other four experimental rooms are prepared for basic experiments. The synchrotron accelerates ions up to 800 MeV/u for a charge to mass ratio of 1/2. The long beam transport line provides two vertical beams in addition with two horizontal beams for the treatment. The three treatment rooms are prepared one of which is equipped with both horizontal and vertical beam lines. The whole facility will be open for all scientists who have interests in the heavy ion science as well as the biophysics. The conceptual design study of HIMAC started in 1984, and the construction of the accelerator complex was begun in March 1988. The beam acceleration tests of the injector system was successfully completed in March of this year, and tests of the whole system will be finished throughout this fyscal year. (author)

  11. Whole study of nuclear matter collective motion in central collisions of heavy ions of the FOPI detector

    International Nuclear Information System (INIS)

    Bendarag, A.

    1999-01-01

    In this work we study the collective phenomena in the central collisions of heavy ions for the Au + Au, Xe + CsI and Ni + Ni systems at incident energies from 150 to 400 MeV/nucleon with the data of the FOPI detector. In order to describe completely the flow of the nuclear matter, we fit the double differential momentum distributions with two-dimensional Gaussian. We study the characteristic parameters of the collective flow (flow range, aspect ratios, flow parameter) versus the charge and the mass of the fragments as well as the incident energy and the centrality of the collisions. The transverse energy is used for selecting the central collisions. The method of the Gaussian fits requires also to reconstruct the reaction plane of the event. Then we correct the parameters for the finite number of particles effects and account for the influence of the acceptance of the detector. We confirm the importance of the thermal motion for the light charge or mass fragments and, conversely, the predominance of the collective motion for the heavy fragments. A common flow angle for all the types of particles is highlighted for the first time, demonstrating the power of the method of the Gaussian fits; The evolution of the other parameters confirms the observations done with other methods of flow analysis. These results should contribute to put constraints on the collision models and to enlarge our knowledge of the properties of the nuclear matter. (author)

  12. Ultra thin layer activation by recoil implantation of radioactive heavy ions. Applicability in wear and corrosion studies

    International Nuclear Information System (INIS)

    Lacroix, O.; Sauvage, T.; Blondiaux, G.; Guinard, L.

    1997-07-01

    A new calibration procedure is proposed for the application of recoil implantation of radioactive heavy ions (energies between a few hundred keV and a few MeV) into the near surface of materials as part of a research programme on sub-micrometric wear or corrosion phenomena. The depth profile of implanted radioelements is performed by using ultra thin deposited films obtained by cathode sputtering under argon plasma. Two curves for 56 Co ion in nickel have been determined for implantation depths of 110 and 200 nm, respectively, and stress the feasibility and reproducibility of this method for such activated depths. The achieved surface loss detection sensitivities are about 1 and 2 nm respectively. The on line detection mode is performed directly on the sample of interest. A general description of the method is presented. A study of the reaction kinematics followed by a general treatment on the irradiation parameters to be adopted are also developed with the intention of using the ultra thin layer activation method (UTLA) to further applications in research and industry. (author)

  13. Heavy-ion driver parametric studies and choice of a base 5 mega-joule driver design

    International Nuclear Information System (INIS)

    Bieri, R.; Meier, W.

    1992-01-01

    Parametric studies to optimize heavy-ion driver designs are described and an optimized 5 MJ driver design is described. Parametric studies are done on driver parameters including driver energy, number of beams, type of superconductor used in focusing magnets, maximum magnetic field allowed at the superconducting windings, axial quadrupole field packing fraction, ion mass, and ion charge state. All modeled drivers use the maximum beam currents allowed by the Maschke limits; driver scaling is described in a companion paper. The optimized driver described is conservative and cost effective. The base driver direct costs are only $120/Joule, and the base driver uses no recirculation, beam combination, or beam separation. The low driver cost achieved is due, in part, to the use of compact Nb 3 Sn quadrupole arrays, but results primarily from optimization over the large, multi-dimensional, parameter space available for heavy-ion drivers

  14. Anisotropic flow studies with identified particles with ALICE: a tool to probe different stages of a heavy-ion collision

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Anisotropic flow studies play a crucial role in the characterization of the nature of the quark gluon plasma (QGP) created in collisions of heavy ions at ultra-relativistic energies. These studies rely on measuring the coefficients vn of the Fourier expansion of the azimuthal particle distribution. They have been essential in establishing that the QGP is a strongly coupled, almost perfect fluid. In this seminar, I review the latest results from measurements of elliptic (v2), triangular (v3), quadrangular (v4) and pentagonal (v5) flow of identified particles at the LHC measured with ALICE. I will discuss how these results allow us to gain insight into the transport properties of the QGP and the initial conditions of a heavy-ion collision. In addition, they reveal the role of different hadronisation mechanisms as well as the highly dissipative hadronic rescattering phase to the development of vn.

  15. Heavy-ion targets

    International Nuclear Information System (INIS)

    Adair, H.L.; Kobisk, E.H.

    1985-01-01

    This chapter examines the characteristics of targets required in heavy-ion accelerator physics experiments. The effects of target parameters on heavy-ion experimental results are reviewed. The target fabrication and characterization techniques used to minimize experimental problems during heavy-ion bombardment are described. Topics considered include target thickness and uniformity, target lifetime, target purity, substrate materials, Doppler shift effects, metal preparations, and target preparation methods

  16. Proceedings of the international conference on dynamical properties of heavy-ion reactions held at the University of the Witwatersrand, Johannesburg, South Africa, 1-3 August 1978. v. 3

    International Nuclear Information System (INIS)

    Sellschop, J.P.F.; Lemmer, R.H.; Toepffer, C.; Engelbrecht, C.A.

    1978-01-01

    At this pre-conference symposium lectures on 'applications of (heavy) ions' were delivered. The following topics were discussed: 1) heavy ions in archaeological dating, 2) nuclear physics in metallurgy, 3) nuclear physics in solid-state research, 4) nuclear probes in geological studies, and 5) nuclear approaches in biological investigations

  17. Study on possibility of development of a laser multicharged ion source for a heavy ion fusion driver

    International Nuclear Information System (INIS)

    Barabash, L.Z.; Krechet, K.I.; Lapitskij, Yu.Ya.; Latyshev, S.V.; Shumshurov, A.V.

    1983-01-01

    The results of studying laser produced plasma ion sources for a heavy ion accelerating-storage complex used as a heavy ion fusion driver are presented. The following parameters were measured on an installation aimed for studying physical characteristics of heavy ion laser plasma for a lead target at laser radiation flux density of approximately 3x10 10 W/cm 2 : scattered ion charge composition, energy spectra and scattering angle distributions, ion currents, absolute number of ions in every charge state, plasma electron temperature. The ion current pulse duration varied from 3x10 -4 s at Z +1 to 2x10 -5 s at Z +10 . The maximum current amplitude of 2 mA corresponded to Z +7 charge. The scattering velocity increased with charge. The total number of ions that could be used for acceleration was approximately 5x10 13 for Z +2 and 5x10 12 for Z +6 per pulse. The ion laser source brightness was 2x10 11 A/cm 2 , the particle phase density was 10 18 (cmxrad) -1

  18. 2nd-order optical model of the isotopic dependence of heavy ion absorption cross sections for radiation transport studies

    Science.gov (United States)

    Cucinotta, Francis A.; Yan, Congchong; Saganti, Premkumar B.

    2018-01-01

    Heavy ion absorption cross sections play an important role in radiation transport codes used in risk assessment and for shielding studies of galactic cosmic ray (GCR) exposures. Due to the GCR primary nuclei composition and nuclear fragmentation leading to secondary nuclei heavy ions of charge number, Z with 3 ≤ Z ≥ 28 and mass numbers, A with 6 ≤ A ≥ 60 representing about 190 isotopes occur in GCR transport calculations. In this report we describe methods for developing a data-base of isotopic dependent heavy ion absorption cross sections for interactions. Calculations of a 2nd-order optical model solution to coupled-channel solutions to the Eikonal form of the nucleus-nucleus scattering amplitude are compared to 1st-order optical model solutions. The 2nd-order model takes into account two-body correlations in the projectile and target ground-states, which are ignored in the 1st-order optical model. Parameter free predictions are described using one-body and two-body ground state form factors for the isotopes considered and the free nucleon-nucleon scattering amplitude. Root mean square (RMS) matter radii for protons and neutrons are taken from electron and muon scattering data and nuclear structure models. We report on extensive comparisons to experimental data for energy-dependent absorption cross sections for over 100 isotopes of elements from Li to Fe interacting with carbon and aluminum targets. Agreement between model and experiments are generally within 10% for the 1st-order optical model and improved to less than 5% in the 2nd-order optical model in the majority of comparisons. Overall the 2nd-order optical model leads to a reduction in absorption compared to the 1st-order optical model for heavy ion interactions, which influences estimates of nuclear matter radii.

  19. Relativistic heavy ion physics

    International Nuclear Information System (INIS)

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

    1992-01-01

    In 1992 a proposal by the Iowa State University experimental nuclear physics group entitled ''Relativistic Heavy Ion Physics'' was funded by the US Department of Energy, Office of Energy Research, for a three-year period beginning November 15, 1991. This is a progress report for the first six months of that period but, in order to give a wider perspective, we report here on progress made since the beginning of calendar year 1991. In the first section, entitled ''Purpose and Trends,'' we give some background on the recent trends in our research program and its evolution from an emphasis on nuclear structure physics to its present emphasis on relativistic heavy ion and RHIC physics. The next section, entitled, ''Physics Research Programs,'' is divided into three parts. First, we discuss our participation in the program to develop a large detector named PHENIX for the RHIC accelerator. Second, we outline progress made in the study of electromagnetic dissociation (ED). A highlight of this endeavor is experiments carried out with the 197 Au beam from the AGS accelerator in April 1991. Third, we discuss progress in completion of our nuclear structure studies. In the final section a list of publications, invited talks and contributed talks starting in 1991 is given

  20. Heavy ion fusion

    International Nuclear Information System (INIS)

    Bock, R.

    1983-01-01

    Two accelerator scenarios for heavy ion fusion are considered as driver candidates for an ICF power plant: the RF linac with storage rings and the induction linac. The necessary beam intensity and beam quality requirements are already believed to be achievable in the long run; repetition rate and accelerator efficiency are not critical issues. Conceptual design studies have indicated that the technical problems of the ICF concept with a heavy ion driver can be solved and that the economical aspects are not prohibitive as compared to other ICF concepts. Nevertheless, many open problems still exist, and some new ones have exhibited themselves, and it has become evident that most of them cannot be investigated with existing facilities and at the present level of effort. The first section of this paper deals with current conceptual design studies and focuses on the interface between the accelerator and the reactor. The second section summarizes the present research programs and recommends that their scope should be expanded and intensified in the areas of accelerator physics and beam-target interaction and target physics. In the third section the author calls for a dedicated facility and reports on the plans and ideas for such a facility. Schematics of two proposed accelerator driver systems--the driver for HIBALL (5 MJ/pulse) and a single-pass four-beam induction linac (3 MJ/pulse)--are provided

  1. Study of deep inelastic collisions in the heavy-ion interaction of (14.0MeV/u){sup 208}Pb+{sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Baluch, J J [Department of Physics, Gomal University, D. I. Khan (Pakistan); Khan, E U [Physics Research Division, Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan); Tahseen, R [Department of Physics, Gomal University, D. I. Khan (Pakistan); Qureshi, I E [Physics Research Division, Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan); Nasir, Tabassum [Department of Physics, Gomal University, D. I. Khan (Pakistan); Hassan, Najam ul [Department of Physics, Gomal University, D. I. Khan (Pakistan)

    2006-02-15

    Using mica as a passive detector and employing the 2{pi}-geometry technique (14.0MeV/u) {sup 208}Pb+{sup 238}U heavy-ion nuclear interaction has been studied. The particle tracks were converted into their actual lengths and polar angles through simple geometry. The elastic binary events so bifurcated were used to deduce the coefficients to analyze the three prong events. The relative velocities of the correlated fission fragments were calculated at the second stage of the reaction in order to construct the intermediate stage of the reaction, and hence, determine the pre-fission masses integrated over all angles and energies. The angular distribution of fission fragments within the reaction plane provided the information about the speed of the reaction and proximity effect.

  2. Study of deep inelastic collisions in the heavy-ion interaction of (14.0MeV/u)208Pb+238U

    International Nuclear Information System (INIS)

    Baluch, J.J.; Khan, E.U.; Tahseen, R.; Qureshi, I.E.; Nasir, Tabassum; Hassan, Najam ul

    2006-01-01

    Using mica as a passive detector and employing the 2π-geometry technique (14.0MeV/u) 208 Pb+ 238 U heavy-ion nuclear interaction has been studied. The particle tracks were converted into their actual lengths and polar angles through simple geometry. The elastic binary events so bifurcated were used to deduce the coefficients to analyze the three prong events. The relative velocities of the correlated fission fragments were calculated at the second stage of the reaction in order to construct the intermediate stage of the reaction, and hence, determine the pre-fission masses integrated over all angles and energies. The angular distribution of fission fragments within the reaction plane provided the information about the speed of the reaction and proximity effect

  3. In situ study of heavy ion induced radiation damage in NF616 (P92) alloy

    International Nuclear Information System (INIS)

    Topbasi, Cem; Motta, Arthur T.; Kirk, Mark A.

    2012-01-01

    Highlights: ► The ferritic–martensitic alloy NF616 was irradiated in situ with 1 MeV Kr ions at 50 K and 473 K. ► The defect cluster density increases with dose and saturates at ∼6 dpa at 50 K and 473 K. ► The defect size distributions do not change with dose at this temperature range. ► Results indicate that defect cluster formation and destruction is governed by cascade impact. - Abstract: NF616 is a nominal 9Cr ferritic–martensitic steel that is amongst the primary candidates for cladding and duct applications in the Sodium-Cooled Fast Reactor, one of the Generation IV nuclear energy systems. In this study, an in situ investigation of the microstructure evolution in NF616 under heavy ion irradiation has been conducted. NF616 was irradiated to 8.4 dpa at 50 K and to 7.6 dpa at 473 K with 1 MeV Kr ions. Nano-sized defects first appeared as white dots in dark-field TEM images and their areal density increased until saturation (∼6 dpa). Dynamic observations at 50 K and 473 K showed appearance and disappearance of TEM-visible defect clusters under irradiation that continued above saturation dose. Quantitative analysis showed no significant change in the average size (∼3–4 nm) and distribution of defect clusters with increasing dose at 50 K and 473 K. These results indicate a cascade-driven process of microstructure evolution under irradiation in these alloys that involves both the formation of TEM-visible defect clusters by various degrees of cascade overlap and cascade induced defect cluster elimination. According to this mechanism, saturation of defect cluster density is reached when the rate of defect cluster formation by overlap is equal to the rate of cluster elimination during irradiation.

  4. Heavy ion beam study of potential formation in bumpy torus plasma

    International Nuclear Information System (INIS)

    Takasugi, Keiichi.

    1985-01-01

    A heavy ion beam probe is constructed for the study of plasma confinement in Nagoya Bumpy Torus (NBT-1/1M). The measurement of the local plasma potential as well as the electron density profile is possible with good spatial (1 -- 2 cm) and temporal (-- 1 msec) resolutions. The feedback controlled detection technique and the time resolved fast detection technique are coupled to use, which enables us to measure local potential reliably even in the pulsed experiments. The process of the devlopment of concentric equipotential surface is observed. The cold and collisional plasma in bumpy torus is not in the equilibrium (C-mode), and the vertically polarized potential profile is produced by the toroidal drift. With the growth of warm collisionless electron component, the polarization is poloidally short-circuited, and the concentric equipotential surface is developed. The concentric negative potential well and its positive rim are observed in the standard operation. The position of the potential boundary (rim) moves with the second harmonic ECRH zone at the midplane of each mirror section, where the hot electron ring exists. The rim potential is formed by the direct loss of warm electrons. It is confirmed that the core electron heating is essential for the negative potential formation. The potential depth is much larger than the ion temperature Tsub(i), and cannot be explained by the existing neoclassical theory. A stable positive potential is observed near T-M transition. The positive potential is also observed in the ion heated plasma. Relating to the growth of the high energy component, the potential formation due to direct loss process is discussed. (author)

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  6. Study of the point defect creation and of the excitonic luminescence in alkali halides irradiated by swift heavy ions

    International Nuclear Information System (INIS)

    Protin, L.

    1994-01-01

    The aim of this experimental thesis is to study the excitonic mechanisms and of the defect creation, in NaCl and KBr, under dense electronic excitations induced by swift heavy ion irradiations. In the first part, we present the main features of the interaction of swift heavy ions with solid targets, and after we review the well known radiolytic processes of the defect creation during X-ray irradiation. In the second chapter, we describe our experimental set-up. In the chapter III, we present our results of the in-situ optical absorption measurements. This results show that defect creation is less sensitive to the temperature than during a classical irradiation. Besides, we observe new mechanisms concerning the defect aggregation. In the chapter IV, we present the results of excitonic luminescence induced by swift by swift heavy ions. We observe that the luminescence yields only change with the highest electronic stopping power. In the chapter V, we perform thermal spike and luminescence yields calculations and we compare the numerical results to the experiments presented in the chapter IV. (author). 121 refs., 65 figs., 30 tabs

  7. Experimental and theoretical study of heavy ion slowing down in solid targets

    International Nuclear Information System (INIS)

    Mehana, A.

    1993-06-01

    Heavy ion energy losses in C, Al, Cu, Ag, Ta and Au solid targets have been measured at high energy (0.2 to 5 MeV/u), using the backward secondary ion technique, and at low energy (0.1 to 0.25 MeV/u) for the C, N and O ions, using the particle backscatter method. A brief review of the various matter-induced charged particle slowing down theories, and especially the Lindhard dielectric theory, is first presented. Then, the various models for the evaluation of the effective charge and of the high order correction, are discussed and compared. Experimental techniques and data processing methods are described, and the experimental results are compared to calculations derived from the dielectric theory. In particular, the effective charges and the high order corrections (Barkas-Bloch) are examined and compared to the models for the determination of the z 3 and z 4 terms for heavy ions

  8. TDHF-motivated macroscopic model for heavy ion collisions: a comparative study

    International Nuclear Information System (INIS)

    Biedermann, M.; Reif, R.; Maedler, P.

    1984-01-01

    A detailed investigation of Bertshc's classical TDHF-motivated model for the description of heavy ion collisions is performed. The model agrees well with TDHF and phenomenological models which include deformation degrees of freedom as well as with experimental data. Some quantitative deviations from experiment and/or TDHF can be removed to a large extent if the standard model parameters are considered as adjustable parameters in physically reasonable regions of variation

  9. Diogene: A 4PI detector for studying central collisions of relativistic heavy ions

    International Nuclear Information System (INIS)

    Babinet, R.

    1984-01-01

    Heavy ion beams up to 1.15 Gev/amu should soon be available at the Saturne II facility. In this prospect a small time projection chamber has been built which allows to reconstruct all the light charged particles (π,p,d...) tracks for large multiplicity events (approximately 40). As a first test of the experimental set up, some data taking has already started with 4He-beams at 400, 600 and 800 MeV/amu

  10. Coupled chemical reactions in dynamic nanometric confinement: VII. Biosensors based on swift heavy ion tracks with membranes

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Munoz, G. H.; García Arellano, H.; Alfonta, L.; Vacík, Jiří; Kiv, A.; Hnatowicz, Vladimír

    2017-01-01

    Roč. 172, 1-2 (2017), s. 159-173 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : biotechnology * tracks * swift heavy ions * polymers * etching Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nano-materials (production and properties) Impact factor: 0.443, year: 2016

  11. Recent Progress in Constraining the Equation of State of Dense Neutron-Rich Nuclear Matter with Heavy-Ion Reactions

    International Nuclear Information System (INIS)

    Li Baoan; Chen Liewen; Wen Dehua; Xiao Zhigang; Xu Chang; Yong Gaochan; Zhang Ming

    2010-01-01

    The nuclear symmetry energy E sym (ρ) is the most uncertain part of the Equation of State (EOS) of dense neutron-rich nuclear matter. In this talk, we discuss the underlying physics responsible for the uncertain E sym (ρ) especially at supra-saturation densities, the circumstantial evidence for a super-soft E sym (ρ) from analyzing π - /π + ratio in relativistic heavy-ion collisions and its impacts on astrophysics and cosmology.

  12. Semi-classical precompound decay models for heavy ion reactions of 10-100 MeV/nucleon

    International Nuclear Information System (INIS)

    Blann, M.

    1986-01-01

    The hybrid and Boltzmann master equation, which predict heavy ion precompound decay phenomena, are investigated. These are both semi-classical approaches. The physical concepts of these two models are discussed, and their numerical formulations are summarized. Their success in reproducing experimentally measured (HI,n) spectra and in estimating limits on beam momentum transfer due to the precompound nucleon emission cascade are summarized. Results of calculations for subthreshold pion production are presented and compared with experimental yields. 19 refs., 5 figs

  13. Study of the interaction between heavy ions and integrated circuits using a pulsed laser beam

    International Nuclear Information System (INIS)

    Lewis, D.; Fouillat, P.; Pouget, V.; Lapuyade, H.

    2002-01-01

    A new pulsed laser beam equipment dedicated to the characterization of integrated circuit is presented. Using ultra-short laser pulses is a convenient way to simulate experimentally the spatial environment of integrated circuits when interactions with heavy ions occur. This experimental set-up can be considered as a complementary tool for particle accelerators to evaluate the hardness assurance of integrated circuits for space applications. These particles generate temporally electrical disturbance called Single Event Effect (SEE). The theoretical approach of an equivalence between heavy ions and a laser pulses is discussed. The experimental set-up and some relevant operational methodologies are presented. Experimental results demonstrate that the induced electrical responses due to an heavy ion or a laser pulse are quite similar. Some sensitivity mappings of integrated circuits provided by this test bench illustrate the capabilities and the limitations of this laser-based technique. Contrary to the particle accelerators, it provides useful information concerning the spatial and temporal dependences of SEE mechanisms. (authors)

  14. Studies of relativistic heavy ion collisions. Final report, July 16, 1987-December 31, 1997

    International Nuclear Information System (INIS)

    Madansky, L.

    1997-01-01

    As a member of the DLS collaboration, the Hopkins group participated in all aspects of the experiment and the analysis of the results. The recent work involved measurements of dielectrons from p-p, p-d collisions as well as heavy ion Ca-Ca collisions at high densities. These results show the expected effects of bremsstrahlung vector meson decay and Dalitz decay but still show that some varieties of the low mass cross-sections disagree with various theoretical estimates, which could indicate other effects of high nuclear density. The Hopkins group has also been an initial member of the STAR collaboration and helped initiate the proposal for jet searches in the heavy ion experiments at RHIC. The group was instrumental in initiating the first stage of an electro-magnetic calorimeter for these experiments. The group also joined (E896) the Ho experiment. This work was primarily devoted to finding the existence of an elementary system containing strange quarks. An initial experiment was done recently at which Hopkins provided various beam counters. The final work is expected to commence in the fall of '98. Finally, the group has contributed to a number of experiments involving polarization effects in nuclear collisions, searching for production of antimatter, and other aspects of relativistic collisions of heavy ions using the facilities at Brookhaven National Laboratory (BNL)

  15. Heavy ion collisions and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Floerchinger, Stefan

    2016-12-15

    There are interesting parallels between the physics of heavy ion collisions and cosmology. Both systems are out-of-equilibrium and relativistic fluid dynamics plays an important role for their theoretical description. From a comparison one can draw interesting conclusions for both sides. For heavy ion physics it could be rewarding to attempt a theoretical description of fluid perturbations similar to cosmological perturbation theory. In the context of late time cosmology, it could be interesting to study dissipative properties such as shear and bulk viscosity and corresponding relaxation times in more detail. Knowledge and experience from heavy ion physics could help to constrain the microscopic properties of dark matter from observational knowledge of the cosmological fluid properties.

  16. Heavy ion collisions at energies near the Coulomb barrier 1990

    International Nuclear Information System (INIS)

    Nagarajan, M.A.

    1991-01-01

    During recent years, detailed experimental and theoretical investigations have been carried out on heavy ion collisions at energies close to the Coulomb barrier. These studies have provided direct evidence of strong couplings between the various reaction channels available at energies near the top of the Coulomb barrier. This field of research has remained the focus of interest and with improved experimental techniques, new detailed high resolution data have been obtained. The workshop on ''Heavy Ion Collisions at Energies Close to the Coulomb Barrier'' was organized with the aim of reviewing the current understanding of the collision dynamics and to discuss future directions in this area of research. The topics discussed at the workshop were broadly classified under the titles: quasielastic reactions; fusion of heavy ions; and shape and spin dependence in heavy ion collisions. The last of these topics was included to review new data obtained with polarized heavy ions and their theoretical interpretations. This volume contains the invited and contributed talks as well as a few short presentations during panel discussions. (author)

  17. Dynamical limitations to heavy ion fusion

    International Nuclear Information System (INIS)

    Back, B.B.

    1983-01-01

    Dynamical limitations to heavy ion fusion reaction are considered. The experimental signatures and the importance of a quasi-fission process are examined. The anaular distributions of fission fragments for the 32 S+ 208 Pb and 16 O+ 238 U systems are presented. It is shown that the observations of quasi-fission for even rather ''light'' heavy ions poeess severe limitations on the fusion process. This result may consequently be responsible for the lack of success of the search for super heavy elements in heavy ion fusion reactions

  18. Nuclear reaction studies

    International Nuclear Information System (INIS)

    Alexander, J.M.; Lacey, R.A.

    1994-01-01

    Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

  19. UMo nuclear fuels behaviour under heavy ion irradiation: a μ-XAS study

    International Nuclear Information System (INIS)

    Palancher, H.; Martin, P.; Dubois, S.; Valot, C.; Sabathier, C.; Palancher, H.; Nassif, V.; Proux, O.; Hazemann, J.L.; Wieschalla, N.; Petry, W.; Jarousse, C.

    2007-01-01

    Full text of publication follows. A worldwide program encourages the use of low enriched uranium (LEU, 235 U 235 U concentration up to 93 wt. %). Due to the decrease in 235 U enrichment for the conversion to LEU, the total density of uranium atoms in the fuel must be increased accordingly. To preserve the neutron flux, metallic uranium alloys could be the best fuel material. The fuel, which consists of UMo alloy spherical particles surrounded by an Al matrix (cf. Figure 1-A), is rolled between two aluminium claddings. Post-irradiation examinations of U-7 wt%Mo demonstrated its strong potentialities as fuel but they also pointed out its interaction with aluminium (cf. Figure 1-B). In certain cases this interaction can cause a break-away swelling of the plate. The aim of this project is the understanding of: - the phenomena driving the growth of the interaction layer. - the influence on interaction layer composition of limited adjunction of elements (silicon...) to the Al matrix. To overcome the difficulties inherent to the in-pile irradiated samples, an out-of-pile methodology (collaboration between CEA, FRM II and CERCA) has been developed based on heavy ion irradiation. This methodology enables to simulate the fission fragment damages using a 80 MeV iodine beam at the Maier Leibnitz laboratory (Garching, Germany). After irradiation, samples are characterised at micrometer scale by microscopy (SEM coupled with EDX) and X-Ray techniques (XRD and XAS). The irradiation (final dose: 2 x 10 17 at/cm 2 ) of undoped U-7 wt%Mo fuel plates leads to the formation of an interaction layer surrounding each fuel particles (cf. Figure 1-C). μ-XRD analysis performed at the ESRF (ID18f) showed only the presence of UAl 3 phase in the interaction layer. Same results have been obtained on in-pile irradiated fuel by Sears et al using neutron diffraction confirming the interest of the developed methodology. However the behaviour of the Mo atoms in the interaction layer could not be

  20. Future relativistic heavy ion experiments

    International Nuclear Information System (INIS)

    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

  1. TDHF calculations for heavy-ion collisions

    International Nuclear Information System (INIS)

    Dhar, A.K.

    1981-01-01

    In considering the TDHF theory for heavy-ion reaction calculations it is shown that this parameter-free approach spans a wide range of nuclear phenomena ranging from elastic scattering to fusion, including dissipative and collective processes, in a unified manner. The subject is considered under the headings: (1) TDHF equations, conservation laws, effective hamiltonian and initial conditions. (2) Symmetries and filling approximation. (3) Qualitative features of TDHF dynamics. (4) Comparison with experiment (fusion results, deep-inelastic reaction studies, particle emission from TDHF calculations). (U.K.)

  2. Relativistic heavy ion physics

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  3. Relativistic heavy ion research at Berkeley

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The project of a superconducting synchrotron for heavy ions with 1 TeV/amu is described. In this connection the physics is discussed which can be studied by this accelerator. Furthermore, the HISS-heavy ion spectrometer system and the Plastic Ball detector are described. (HSI).

  4. Phenomenological approaches of dissipative heavy ion collisions

    International Nuclear Information System (INIS)

    Ngo, C.

    1983-09-01

    These lectures describe the properties of dissipative heavy ion collisions observed in low bombarding energy heavy ion reactions. These dissipative collisions are of two different types: fusion and deep inelastic reactions. Their main experimental properties are described on selected examples. It is shown how it is possible to give a simple interpretation to the data. A large number of phenomenological models have been developped to understand dissipative heavy ion collisions. The most important are those describing the collision by classical mechanics and friction forces, the diffusion models, and transport theories which merge both preceding approaches. A special emphasis has been done on two phenomena observed in dissipative heavy ion collisions: charge equilibratium for which we can show the existence of quantum fluctuations, and fast fission which appears as an intermediate mechanism between deep inelastic reactions and compound nucleus formation [fr

  5. Comparative study of energy accounting for heavy ion fusion with various driver accelerators

    International Nuclear Information System (INIS)

    Kawasaki, S.; Miyahara, A.

    1980-04-01

    Typical designs of driver heavy ion accelerator systems are referred and compared with regard to the assessment of the energy payback problem involved in their applications to the inertial fusion. Detailed analyses show that the energy investment for the construction of the HIF power station is fairly smaller than the energy produced by the station in its lifetime, in spite of the large scale of its hardware. The situation could be more favourable than, or at least comparable with, the case of the magnetically confined fusion. (author)

  6. HIBALL-II - an improved conceptual heavy ion beam driven fusion reactor study

    International Nuclear Information System (INIS)

    Badger, B.; Corradini, M.; El-Guebaly, L.; Engelstad, R.; Henderson, D.; Klein, A.; Kulcinski, G.; Larsen, E.; Lovell, E.; Moses, G.; Peterson, R.; Pong, L.; Sawan, M.; Sviatoslavsky, I.; Symon, K.; Vogelsang, W.; White, A.; Wittenberg, L.; Beckert, K.; Bock, R.; Boehne, D.; Hofmann, I.; Keller, R.; Mueller, R.; Bozsik, I.; Jahnke, A.; Brezina, J.; Nestle, H.; Wendel, W.; Wollnik, H.; Lessmann, E.; Froehlich, R.; Goel, B.; Hoebel, W.; Kessler, G.; Moellendorff, U. von; Moritz, N.; Plute, K.; Schretzmann, K.; Sze, D.

    1985-07-01

    An improved design of the HIBALL inertial-confinement fusion power station is presented. The new RF-linac based heavy ion driver has improved concepts for beam stacking, bunching and final focusing. The new target design takes into account radiation transport effects in a coarse approximation. The system of four reactors with a net total output of 3.8 GW electric is essentially the same as described earlier, however, progress in the analysis has enhanced its credibility and self-consistency. Considerations of environmental and safety aspects and cost estimates are given. (orig.) [de

  7. Numerical simulation studies of the LBNL heavy-ion beam combiner experiment

    International Nuclear Information System (INIS)

    Fawley, W.M.; Seidl, P.; Haber, I.; Friedman, A.; Grote, D.P.

    1997-01-01

    Transverse beam combining is a cost-saving option employed in many designs for heavy-ion inertial fusion energy drivers. A major area of interest, both theoretically and experimentally, is the resultant transverse phase space dilution during the beam merging process. Currently, a prototype combining experiment is underway at LBNL and we have employed a variety of numerical descriptions to aid in both the initial design of the experiment data. These range from simple envelope codes to detailed 2- and 3-D PIC simulations. We compare the predictions of the different numerical models to each other and to experimental data at different longitudinal positions

  8. HISTRAP [Heavy Ion Storage Ring for Atomic Physics] prototype hardware studies

    International Nuclear Information System (INIS)

    Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.

    1989-01-01

    HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs

  9. Study of heavy ions collision at SIS energies with the detector FOPI; Etude des collisions d'ions lourds aux energies de SIS avec le detecteur FOPI

    Energy Technology Data Exchange (ETDEWEB)

    Bastid, N

    1999-09-23

    The present work has been carried out in the framework of experiments performed with the FOPI detector at the SIS/ESR accelerator facility of GSI-Darmstadt. It is devoted to the study of central and semi-central heavy ion collisions at beam energies ranging from 100 MeV to 2 GeV per nucleon. We present first generalities on relativistic heavy ion collisions then the FOPI detector with a special attention to the FOPI Inner Wall constructed by the Clermont-Ferrand group. The main results of the FOPI collaboration obtained with light and intermediate mass fragments and kaons are presented. A systematic study of the different forms of collection motion of nuclear matter, radial flow in very central reactions, sideward flow and squeeze-out in semi-central collisions, is performed. Further exciting possibilities concerning production and propagation of strangeness at SIS energies will be offered soon with the upgrade of the FOPI detector. The FOPI data have introduced constraints on parameters of theoretical models. Important progress concerning the knowledge of the properties of nuclear matter, the dynamics of the collisions and in-medium effects have been achieved. (author)

  10. Fourier analysis of nonself-averaging quasiperiodic oscillations in the excitation functions of dissipative heavy-ion collisions: quantum chaos in dissipative heavy-ion collisions?

    International Nuclear Information System (INIS)

    Kun, S.Yu.; Australian Nat. Univ., Canberra; Australian National Univ., Canberra, ACT

    1997-01-01

    We employ stochastic modelling of statistical reactions with memory to study quasiperiodic oscillations in the excitation functions of dissipative heavy-ion collisions. The Fourier analysis of excitation function oscillations is presented. It suggests that S-matrix spin and parity decoherence, damping of the coherent nuclear rotation and quantum chaos are sufficient conditions to explain the nonself-averaging of quasiperiodic oscillations in the excitation functions of dissipative heavy-ion collisions. (orig.)

  11. Heavy-ion dosimetry

    International Nuclear Information System (INIS)

    Schimmerling, W.

    1980-03-01

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

  12. Heavy ion physics

    International Nuclear Information System (INIS)

    Kalpakchieva, R.; Cherepanov, E.A.

    1993-01-01

    The international school-seminar on heavy ion physics had been organized in Dubna in may of 1993. The scientific program of reports covers the following main topics: synthesis and properties of heavy nuclei; synthesis and investigation of properties of exotic nuclei; experiments with radioactive nuclear beams; interaction between complex nuclei at low and intermediate energies. It also includes reports on laser spectroscopy and exotic nuclear beams, on some application of heavy ion beams for the problems of solid state physics, on construction of multidetector facilities and on developing of heavy ion accelerator complexes. Short communication

  13. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Keefe, D.; Sessler, A.M.

    1980-01-01

    Inertial fusion has not yet been as well explored as magnetic fusion but can offer certain advantages as an alternative source of electric energy for the future. Present experiments use high-power beams from lasers and light-ion diodes to compress the deuterium-tritium (D-T) pellets but these will probably be unsuitable for a power plant. A more promising method is to use intense heavy-ion beams from accelerator systems similar to those used for nuclear and high-energy physics; the present paper addresses itself to this alternative. As will be demonstrated the very high beam power needed poses new design questions, from the ion-source through the accelerating system, the beam transport system, to the final focus. These problems will require extensive study, both theoretically and experimentally, over the next several years before an optimum design for an inertial fusion driver can be arrived at. (Auth.)

  14. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Keefe, D.; Sessler, A.M.

    1980-07-01

    Inertial fusion has not yet been as well explored as magnetic fusion but can offer certain advantages as an alternative source of electric energy for the future. Present experiments use high-power beams from lasers and light-ion diodes to compress the deuterium-tritium (D-T) pellets but these will probably be unsuitable for a power plant. A more promising method is to use intense heavy-ion beams from accelerator systems similar to those used for nuclear and high-energy physics; the present paper addresses itself to this alternative. As will be demonstrated the very high beam power needed poses new design questions, from the ion source through the accelerating system, the beam transport system, to the final focus. These problems will require extensive study, both theoretically and experimentally, over the next several years before an optimum design for an inertial fusion driver can be arrived at

  15. Funny hills in pion spectra from heavy-ion collisions

    International Nuclear Information System (INIS)

    Rasmussen, J.O.

    1982-03-01

    A discussion of some of the systematic features of the pion spectra in heavy-ions reactions is given. A discussion of the hills and valleys in heavy ion pion spectra that show up at the lower pion energies is given. The following topics are discussed: (1) three kinds of funny hills; (2) π - / + ratios near center of mass; (3) new Monte Carlo studies of charged pion spectra; and (4) pion orbiting about fireballs and Bose-Einstein behavior as explanation for the mid-rapidity P/sub perpendicular to/ approx. = 0.4 to 0.5 m/sub π/c hill

  16. Summary of heavy ion theory

    International Nuclear Information System (INIS)

    Gavin, S.

    1994-09-01

    Can we study hot QCD using nuclear collisions? Can we learn about metallic hydrogen from the impact of comet Shoemaker-Levy 9 on Jupiter? The answer to both questions may surprise you exclamation point I summarize progress in relativistic heavy ion theory reported at DPF '94 in the parallel sessions

  17. 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.

  18. Study on the desorption yield for natural botanic sample induced by energetic heavy ions

    CERN Document Server

    Xue, J M; Du, G H; Yan, S; Zhao, W J

    2002-01-01

    The dependence of desorption yield for the natural botanic sample bombarded with heavy ion on the electronic stopping power (S sub e) and dose has been measured by weighing sample mass before and after irradiation. Primary ions including 50 keV N sup + , 1.5 MeV F sup + , 3.0 MeV F sup 2 sup + , 4.0 MeV F sup 2 sup + and 3.0 MeV Si sup 2 sup + were used in the experiment. Three megaelectron volts of F sup 2 sup + with doses ranging from 4x10 sup 1 sup 5 to 4x10 sup 1 sup 6 ions/cm sup 2 were used in order to investigate the influence of ion dose. A mass spectrum from the sample bombarded with 3 MeV Si sup 2 sup + was also taken for a better understanding of the desorption process. Results show that the natural botanic sample is very easily to be desorpted. The yield of MeV heavy ions can be as high as thousands CH sub 2 O/ion, and significantly depends on both the S sub e and dose. The measured yields increase quickly with S sub e , but drop down with increasing ion dose. These results fit roughly with the pr...

  19. Study on the desorption yield for natural botanic sample induced by energetic heavy ions

    International Nuclear Information System (INIS)

    Xue, J.M.; Wang, Y.G.; Du, G.H.; Yan, S.; Zhao, W.J.

    2002-01-01

    The dependence of desorption yield for the natural botanic sample bombarded with heavy ion on the electronic stopping power (S e ) and dose has been measured by weighing sample mass before and after irradiation. Primary ions including 50 keV N + , 1.5 MeV F + , 3.0 MeV F 2+ , 4.0 MeV F 2+ and 3.0 MeV Si 2+ were used in the experiment. Three megaelectron volts of F 2+ with doses ranging from 4x10 15 to 4x10 16 ions/cm 2 were used in order to investigate the influence of ion dose. A mass spectrum from the sample bombarded with 3 MeV Si 2+ was also taken for a better understanding of the desorption process. Results show that the natural botanic sample is very easily to be desorpted. The yield of MeV heavy ions can be as high as thousands CH 2 O/ion, and significantly depends on both the S e and dose. The measured yields increase quickly with S e , but drop down with increasing ion dose. These results fit roughly with the prediction of the pressure pulse model

  20. A double zero-dispersion magnetic spectrometer used in a telescopic mode for very forward heavy ions studies

    International Nuclear Information System (INIS)

    Bacri, C.O.; Roussel, P.

    1990-01-01

    An original method based on the use of a double magnetic spectrometer in a telescopic mode is proposed for the studies of heavy ions collisions both at very forward angles and for magnetic rigidities close to that of the beam. It consists in the direct measurement of angular distributions on doubly - Bρ and angle - sorted events. The method has been tested on the LISE spectrometer at GANIL with a 44 MeV/A 40 Ar beam impinging on C, Al, Ni and Au targets. Milliradian angular accuracy have been obtained at magnetic rigidities as close as 0.9977 of that of the beam

  1. Heavy ion accelerators

    International Nuclear Information System (INIS)

    Schmelzer, C.

    1974-01-01

    This review of the present state of work on heavy-ion accelerators pays particular attention to the requirements for nuclear research. It is divided into the following sections: single-particle versus collective acceleration, heavy-ion accelerators, beam quality, and a status report on the UNILAC facility. Among the topics considered are the recycling cyclotron, linacs with superconducting resonators, and acceleration to the GeV/nucleon range. (8 figures, 2 tables) (U.S.)

  2. 3-megajoule heavy-ion fusion driver

    International Nuclear Information System (INIS)

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

    1981-06-01

    The initiation of inertial confinement fusion reactions with a heavy ion particle beam has been under intensive study since 1976, and the progress of this study is principally documented in the proceedings of annual workshops held by US National Laboratories. At this time a 3MJ, 150 TW, ion beam is a good choice to initiate microexplosions with energy gain of 100. The Lawrence Berkeley Laboratory has made systems studies based on a Linear Induction Accelerator to meet the beam requirements. The accelerator system, expected performance and cost, and technical problems to be addressed in the near future are discussed

  3. Beam dynamics in heavy ion induction LINACS

    International Nuclear Information System (INIS)

    Smith, L.

    1981-10-01

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

  4. Now day methods for heavy ion monitoring

    International Nuclear Information System (INIS)

    Luk'yanov, S.M.; Penionzhkevich, Yu.Eh.; Chubaryan, G.G.

    1984-01-01

    Up-to-date methods for identification of products yield as a result of heavy ion interaction with nuclei are described. Monitoring of total ionization has been realized by gas-filled ionization chambers semiconductor detectors, scintillators. A method for specific ionization loss monitoring and time-of-flight technique for heavy-ion mass identification are considered. Advantages of the method for identification of nuclear reaction prodUcts by means of a magnetic analyzer are displayed

  5. Mutation induction by heavy ions

    Science.gov (United States)

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

    1994-10-01

    Mutation induction by heavy ions is compared in yeast and mammalian cells. Since mutants can only be recovered in survivors the influence of inactivation cross sections has to be taken into account. It is shown that both the size of the sensitive cellular site as well as track structure play an important role. Another parameter which influences the probability of mutation induction is repair: Contrary to naive assumptions primary radiation damage does not directly lead to mutations but requires modification to reconstitute the genetic machinery so that mutants can survive. The molecular structure of mutations was analyzed after exposure to deuterons by amplification with the aid of polymerase chain reaction. The results-although preliminary-demonstrate that even with densely ionizing particles a large fraction does not carry big deletions which suggests that point mutations may also be induced by heavy ions.

  6. A study of defect cluster formation in vanadium by heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sekimura, Naoto; Shirao, Yasuyuki; Morishita, Kazunori [Tokyo Univ. (Japan)

    1996-10-01

    Formation of defect clusters in thin foils of vanadium was investigated by heavy ion irradiation. In the very thin region of the specimens less than 20 nm, vacancy clusters were formed under gold ion irradiation, while very few clusters were detected in the specimens irradiated with 200 and 400 keV self-ions up to 1 x 10{sup 16} ions/m{sup 2}. The density of vacancy clusters were found to be strongly dependent on ion energy. Only above the critical value of kinetic energy transfer density in vanadium, vacancy clusters are considered to be formed in the cascade damage from which interstitials can escape to the specimen surface in the very thin region. (author)

  7. Study of plasma confinement in ELMO Bumpy Torus with a heavy-ion beam probe

    Energy Technology Data Exchange (ETDEWEB)

    Bieniosek, F. M.

    1981-01-01

    Plasma confinement in ELMO Bumpy Torus (EBT) is generally strongly dependent on an ambipolar electric field. Spatially resolved measurements of the resulting electric space potential phi/sub sp/ have been made in a single plasma cross section by the heavy-ion beam probe. This diagnostic injects a 4-60-keV beam of (usually) Cs/sup +/ ions into the plasma. Measurement of the energy of Cs/sup 2 +/ secondary ions leaving the plasma gives a continuous monitor of the local space potential. In addition, the total detected Cs/sup 2 +/ ion current is proportional to the product of the local electron density and the ionization rate, which, in turn, is a function of the electron temperature. This signal, nf(T/sub e/), is sensitive to all three electron distributions found in EBT - those of the cold surface plasma, the warm core plasma, and the hot electron ring.

  8. Study of plasma confinement in ELMO Bumpy Torus with a heavy-ion beam probe

    International Nuclear Information System (INIS)

    Bieniosek, F.M.

    1981-01-01

    Plasma confinement in ELMO Bumpy Torus (EBT) is generally strongly dependent on an ambipolar electric field. Spatially resolved measurements of the resulting electric space potential phi/sub sp/ have been made in a single plasma cross section by the heavy-ion beam probe. This diagnostic injects a 4-60-keV beam of (usually) Cs + ions into the plasma. Measurement of the energy of Cs 2+ secondary ions leaving the plasma gives a continuous monitor of the local space potential. In addition, the total detected Cs 2+ ion current is proportional to the product of the local electron density and the ionization rate, which, in turn, is a function of the electron temperature. This signal, nf(T/sub e/), is sensitive to all three electron distributions found in EBT - those of the cold surface plasma, the warm core plasma, and the hot electron ring

  9. Design study of primary ion provider for relativistic heavy ion collider electron beam ion source.

    Science.gov (United States)

    Kondo, K; Kanesue, T; Tamura, J; Okamura, M

    2010-02-01

    Brookhaven National Laboratory has developed the new preinjector system, electron beam ion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.

  10. Study of the mechanisms of heavy-ion induced desorption on accelerator-relevant materials

    International Nuclear Information System (INIS)

    Bender, Markus

    2008-01-01

    The ion beam loss induced desorption is a performance limitation for low charge state heavy ion accelerators. If charge exchanged projectile ions get lost onto the beam pipe, desorption of gas is stimulated resulting in a pressure increase inside of the synchrotron and thus, a dramatically reduction of the beam life time. To minimize the amount of desorbed gas an experimental program has been started to measure the desorption yields (released gas molecules per incident ion) of various materials and different projectile ions. The present work is a contribution to the understanding of the physical processes behind the ion beam loss induced desorption. The yield measurements by the pressure rise method have been combined for the rst time with in situ ion beam analysis technologies such as ERDA and RBS. With this unique method the desorption behavior of a sample can be correlated to its surface and bulk properties. The performed experiments with 1,4 MeV/u Xenon-Ions show that the ion induced desorption is mainly a surface effect. Sputtered oxide layers or impurities do not contribute to the desorbed gas significantly. Nevertheless bulk properties play an important role in the desorption strength. Pure metallic samples desorb less gas than isolating materials under swift heavy ion irradiation. From the experimental results it was possible to estimate the desorption yields of various materials under ion bombardment by means of an extended inelastic thermal-spike-model. The extension is the combination of the thermal-spike's temperature map with thermal desorption. Within this model the ion induced desorption can be regarded as the release of adsorbates from a transient overheated spot on the samples surface around the ion impact. Finally a copper substrate with a gold coated surface was developed and proposed as a suitable material for a beam loss collimator with minimum desorption to ensure the performance of GSI's SIS18 in high current beam operation. (orig.)

  11. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    Wallace, S.J.

    1991-05-01

    This report discusses topics in the following areas: Hadronic structure; hadrons in nuclei; hot hadronic matter; relativistic nuclear physics and NN interaction; leptonic emissions from high-Z heavy ion collisions; theoretical studies of heavy ion dynamics; nuclear pre-equilibrium reactions; classical chaotic dynamics and nuclear structure; and, theory of nuclear fission

  12. Recent developments in heavy-ion physics

    International Nuclear Information System (INIS)

    Bonche, Paul; Schaeffer, Richard; Grammaticos, Basile; Vichniac, Gerard; Orland, Henri.

    1978-01-01

    In this course the main experimental results on heavy ion reactions are reviewed and the various theoretical methods used in their description are presented. The first chapter attempts a classification of heavy ion reactions, assuming that the various processes depend significantly on the energy available for the reaction and on the relative angular momentum of the collision. The second chapter presents a semi-classical method which makes use of the concept of complex trajectories. Various phenomena such as the absorption along the classical trajectory or the penetration in the classicaly forbidden region can be described in this way. The third chapter deals with the time dependent phenomena in the context of the TDHF theory. The complete formalism is presented, together with a review of the most important theoretical results. In the fourth chapter the nuclear well collision model is presented. This model makes possible the calculation of the elastic, inelastic or transfer reaction probabilities in a microscopic way with no adjustable parameters. Finally in a fifth chapter, various statistical models are developped for the study of deep inelastic collisions [fr

  13. Study of the energetic proton production in relativistic heavy ions Ne + nuclei collisions, using Diogene detector. Hadronic matter temperature

    International Nuclear Information System (INIS)

    Rahmani, A.

    1988-12-01

    The study of the proton's production differential cross sections, in the collision of relativistic heavy ions, allows to obtain the nuclear-matter temperature and gives information about the nucleons large burst pulses in the nucleus. The chosen thermodynamic model is a generalized approach of the R. Hagedorn model, applied to heavy ions collisions: the nuclear matter is divided in volume elements δV assumed to be in thermal and chemical equilibrium and emitting particles and fragments isotropically, inside their own system. The applied nuclear-matter velocity distribution depended only on the impact parameter and on the relationship between the chemical potential and the temperature. The predictions of this thermodynamic model were compared to the Saturne experimental results, using Diogene detector. The obtained temperature values are similar to those given by D. Hahn and H. Stoker. The proton production cross sections were measured for backward emitting angles. A relationship between the cross sections and the burst pulse distribution in the nuclei was settled [fr

  14. Study of the modifications induced in AlxGa1-xN semiconductors under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Moisy, Florent

    2016-01-01

    Nitride semiconductors are attractive materials for optoelectronic applications. They can be subjected to heavy ions in a wide range of energy during their elaboration (improvement of their properties by ionic implantation) or during their potential use in extreme environments (outer space). This thesis focuses on the study of AlxGa1-xN alloys under heavy ion irradiation from GANIL. In GaN, the formation of Ga vacancies has been highlighted, these latter coming from elastic collisions between atoms in the material and the projectiles. On the other hand, it is possible to observe the formation of disordered ion tracks for projectiles with high electronic stopping power (Se). These tracks induce strong surface modifications, a closing of the optical bandgap, but also an extension strain along the direction parallel to the ion direction and biaxial stresses of some GPa. Concerning AlxGa1-xN alloys with x from 0.3 to 1, the points defects are more complex, and a synergy between electronic excitations and nuclear collisions is responsible of their formation. Nevertheless, the increase of the Al molar fraction (x), tends to improve the resistance to ion tracks formation in these materials. (author) [fr

  15. Measurements of activation reaction rates in transverse shielding concrete exposed to the secondary particle field produced by intermediate energy heavy ions on an iron target

    International Nuclear Information System (INIS)

    Ogawa, T.; Morev, M.N.; Iimoto, T.; Kosako, T.

    2012-01-01

    Reaction rate distributions were measured inside a 60-cm thick concrete pile placed at the lateral position of a thick (stopping length) iron target that was bombarded with heavy ions, 400 MeV/u C and 800 MeV/u Si. Foils of aluminum and gold, as well as gold, tungsten and manganese covered with cadmium were inserted at various locations in the concrete pile to serve as activation detectors. Features of reaction rate distribution, such as the shape of the reaction rate profile, contribution of the neutrons from intra-nuclear cascade and that from evaporation to the activation reactions are determined by the analysis of measured reaction rates. The measured reaction rates were compared with those calculated with radiation transport simulation codes, FLUKA and PHITS, to verify their capability to predict induced activity. The simulated reaction rates agree with the experimental results within a factor of three in general. However, systematic discrepancies between simulated reaction rates and measured reaction rates attributed to the neutron source terms are observed.

  16. Investigations in atomic physics by heavy ion projectiles

    International Nuclear Information System (INIS)

    Berenyi, D.

    1983-01-01

    The utilization of heavy ion reactions in atomic physics is surveyed. The basic collision mechanisms and their consequences in atomic physics are summarized. The atomic and electronic processes during and after heavy ion collisions are reviewed as functions of the projectile energy. The main detection and measuring methods are described. Reviews of new information about the structure of electronic cloud and about fundamental processes based on the analysis of heavy ion reaction data are given. (D.Gy.)

  17. Study of heavy ion collisions at Fermi energy: is the methodology orientating our understanding of physics?

    International Nuclear Information System (INIS)

    Bacri, Ch.O.

    2001-07-01

    The analysis of the reaction products in the case of a multi-fragmentation reaction requires an efficient sorting of the experimental data. A collision, detected in a 4π detector generates about 100 parameters that are measured. Experimental data have to be reduced to the part most meaningful of the studied event. A model of the reaction is necessary to discard or value variables on which the sorting could be based. The selection of experimental data implies almost always the introduction of a bias that is necessary to know in order to continue a thorough analysis of the experimental results. A theoretical work is then necessary not only in the view of the comparison between results and predictions but also to validate the assumptions that have been made to sort out the experimental data. This method is applied to the study of the nuclear reaction: Gd + U at 36 MeV/U. (A.C.)

  18. Ultrarelativistic heavy ions

    International Nuclear Information System (INIS)

    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

  19. Heavy Ion Fusion Accelerator Research (HIFAR)

    International Nuclear Information System (INIS)

    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 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

  20. Heavy ions: Report from Relativistic Heavy Ion Collider

    Indian Academy of Sciences (India)

    2012-10-12

    Oct 12, 2012 ... Experiments using ultrarelativistic heavy-ion collisions study nuclear matter under ... sN N = 10 GeV for Pb+Pb collisions, corresponding to an initial .... quenching through systematic comparisons of data to models, and .... the RdAu and RCP = (0−20%)/(60−80%) factors for the J/ψ production in d+Au col-.

  1. [Relativistic heavy ion research

    International Nuclear Information System (INIS)

    1990-01-01

    At Brookhaven National Laboratory, participation in the E802 Experiment, which is the first major heavy-ion experiment at the BNL-AGS, was the main focus of the group during the past four years. The emphases of the E802 experiment were on (a) accurate particle identification and measurements of spectra over a wide kinematical domain (5 degree LAB < 55 degree, p < 20 GeV/c); and (b) measurements of small-angle two-particle correlations, with event characterization tools: multiplicity array, forward and large-angle calorimeters. This experiment and other heavy ion collision experiments are discussed in this report

  2. Heavy ion collisions

    International Nuclear Information System (INIS)

    Jacak, B.V.

    1994-01-01

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

  3. Breeding study of hyper citric acid strain by progressive heavy ion irradiation

    International Nuclear Information System (INIS)

    Chen Jihong; Hu Wei; Li Wenjian; Liu Jing; Wang Shuyang; Wei Zihao

    2013-01-01

    Heavy "1"2C"6"+ ion beams in various high doses were employed to irradiate H3001 strain for screening Aspergillus niger strain for hyper citric acid production. Three high-yield strains were obtained after shaker fermentation test. Among the three strains, the strain hw317 was implemented shaker fermentation for stability test and 10∼100 L pilot fermentation tank for citric acid productive maximization. Acid-base neutralization method was applied to determinate the content of citric acid in fermented liquid. The results showed that: when the secondary heavy ion "1"2C"6"+ dose was 857.8 Gy, both of the fatality rate (94.5%) and the positive mutation rate (8%) were highest. Through the shaker fermentation tests and 10∼100 L pilot fermentation test, one strain hw317 was screened and obtained for hyper citric acid production. Consequently, the final citric acid acidity can reach up to 19.2±0.2% with controlling fermentation cycle for 60 h. (authors)

  4. Study on laser plasma as an ion source for the controlled fasion with heavy ions

    International Nuclear Information System (INIS)

    Barabash, L.Z.; Bykovskij, Yu.A.; Golubev, A.A.; Kozyrev, Yu.P.; Krechet, K.I.; Lapitskij, Yu.Ya.; Sharkov, B.Yu.

    1981-01-01

    The results of experimental investigations of Pb 208 multiply- charged lead ions, obtained in the course of CO 2 laser radiation effect on a solid target are presented. The experimental installation, the basic units of which are CO 2 - laser with transverse discharge, ion source chamber, time- of-flight space, 9-channel electrostatic mirror type mass-analyser with a detection unit, is described. Physical characteristics of a freely spreading laser plasma, ion distribution over energies, velocities and Z charges from Z=+1 to Z=+10 are investigated. Absolute values of ion number of each charge property as well as absolute values of currents are obtained, the laser plasma temperature is estimated. The analysis of time distribution of ion quantity permits to point out the following regularities: with Z increase the ion current duration decreases according to the Δt approximately Z -1 law, with Z increase, the moment of the ion pulse beginning approaches to the moment of target irradiation which testifies that multiply-charged ions have high velocities and energies. The velocity distribution analysis permits to obtain ion velocity dependence in the field of maximum distribution on charge properties. The results presented are obtained at the temperature of hot unspreaded plasma about 60 eV. The data obtained are a basis for development of a real laser forinjector for the problems of the controlled fusion with heavy ions [ru

  5. Studies of the mirrortron ion accelerator concept and its application to heavy-ion drivers

    International Nuclear Information System (INIS)

    Post, R.F.; Schwager, L.A.; Dougless, S.R.; Jones, B.R.; Lambert, M.A.; Larson, D.L.

    1991-01-01

    The Mirrortron accelerator is a plasma-based ion accelerator concept that, when implemented, should permit both higher acceleration gradients and higher peak-current capabilities than is possible with conventional induction-type accelerators. Control over the acceleration and focussing of an accelerated beam should approach that achieved in vacuum-field-based ion accelerators. In the Mirrortron a low density (10 10 to 10 11 cm -3 ) ''hot electron'' plasma is confined by a long solenoidal magnetic field capped by ''mirrors''. Acceleration of prebunched ions is accomplished by activating a series of fast-pulsed mirror coils spaced along the acceleration tube. The hot electrons, being repelled by mirror action, leave the plasma ions behind to create a localized region of high electrical gradient (up to of order 100 MV/m). At the Laboratory an experiment and analyses to elucidate the concept and its scaling laws as applied to heavy-ion drivers are underway and will be described. 4 refs., 5 figs

  6. Moessbauer effect studies of the recovery of iron after heavy-ion implantation at 7 K

    International Nuclear Information System (INIS)

    Reintsema, S.R.; Drentje, S.A.; Waard, H. de

    1978-01-01

    Moessbauer effect measurements were performed with sources of 133 Xe implanted at 7 K in polycrystalline iron foils by means of an isotope separator. Information about the direct environment of an implanted radioactive probe atom is obtained through the hyperfine interaction of the daughter nucleus ( 133 Cs) with its surroundings. The Moessbauer spectra were analyzed on the basis of an earlier model, assuming three visible spectral components with high, intermediate and low hyperfine fields and recoilless fractions, respectively, and a fourth, invisible component with a recoilless fraction very close to zero. Annealing experiments showed no evidence for post-implantation recovery stage I in the iron foils, while recovery stage II only gave rise to small changes in the site occupations. These results can be explained in terms of the high energy density locally deposited in the lattice by each implanted atom, leading to stage I recovery during the very short time that is necessary for the thermal dissipation of this energy. Quantitatively, these results are confirmed by calculations of Sigmund on heavy-ion induced elastic-collision spikes in solids. After annealing at room temperature the site occupations agree with those obtained directly with room temperature implanted sources. In previous experiments it has been shown that different results are obtained for annealing and for implantation at 200 0 C. From these results the authors estimate the migration energy of vacancies in iron at 1.27 +- 0.09 eV. (Auth.)

  7. Study of Radiation Hardness of Gd2SiO5 scintillator for Heavy Ion Beam

    CERN Document Server

    Kawade, K; Itow, Y; Masuda, K; Murakami, T; Sako,T; Suzuki, K; Suzuki, T; Taki, K

    2011-01-01

    Gd2SiO5 (GSO) scintillator has very excellent radiation resistance, a fast decay time and a large light yield. Because of these features, GSO scintillator is a suitable material for high radiation environment experiments such as those encountered at high energy accelerators. The radiation hardness of GSO has been measured with Carbon ion beams at the Heavy Ion Medical Accelerator in Chiba (HIMAC). During two nights of irradiation the GSO received a total radiation dose of 7 × 10$^5$ Gy and no decrease of light yield was observed. On the other hand an increase of light yield by 25% was observed. The increase is proportional to the total dose, increasing at a rate of 0.025%/Gy and saturating at around 1 kGy. Recovery to the initial light yield was also observed during the day between two nights of radiation exposure. The recovery was observed to have a slow exponential time constant of approximately 1.5 × 10$^4$ seconds together with a faster component. In case of the LHCf experiment, a very forward region ex...

  8. Beam loss studies in high-intensity heavy-ion linacs

    International Nuclear Information System (INIS)

    Ostroumov, P.N.; Aseev, V.N.; Lessner, E.S.; Mustapha, B.

    2004-01-01

    A low beam-loss budget is an essential requirement for high-intensity machines and represents one of their major design challenges. In a high-intensity heavy-ion machine, losses are required to be below 1 W/m for hands-on-maintenance. The driver linac of the Rare Isotope Accelerator (RIA) is designed to accelerate beams of any ion to energies from 400 MeV per nucleon for uranium up to 950 MeV for protons with a beam power of up to 400 kW. The high intensity of the heaviest ions is achieved by acceleration of multiple-charge-state beams, which requires a careful beam dynamics optimization to minimize effective emittance growth and beam halo formation. For beam loss simulation purposes, large number of particles must be tracked through the linac. Therefore the computer code TRACK has been parallelized and calculations are being performed on the JAZZ cluster recently inaugurated at ANL. This paper discusses how this powerful tool is being used for simulations for the RIA project to help decide on the high-performance and cost-effective design of the driver linac

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

    Science.gov (United States)

    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.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, 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.; Michałowski, 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.; Veres, G. I.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2006-08-01

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

  10. Photon-photon and photon-hadron processes in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Baron, N.C.

    1993-11-01

    Photon-photon and photon-hadron interactions in relativistic heavy ion collisions are studied in the framework of the impact parameter dependent equivalent photon approximation. Improvements of this method, like formfactor inclusion and geometrical modifications are developed. In disruptive relativistic heavy ion collisions where the heavy ions overlapp during the collision, electromagnetic processes are an important background to other mechanisms. In peripheral (non-disruptive) relativistic heavy ion collisions where the ions pass each other without strong interactions, the electromagnetic processes can be studied in their pure form. The lepton pair production is an important diagnostic tool in relativistic heavy ion collisions. The coherent γγ lepton pair production is therefore extensively studied in disruptive but also in non-disruptive collisions. The effects of strong interactions on the coherent γγ lepton pair production in disruptive collisions are discussed in terms of a simple stopping model. Coherent γγ dielectron production contributes to the dilepton production in high energy hadron-hadron collisions. As an example, the coherent dielectron production in π - p collisions is studied in terms of the equivalent photon approximation. Peripheral ultrarelativistic heavy ion collisions open up new possibilities for γγ physics. Taking into account γA background reactions, typical γγ processes in the relevant invariant mass ranges are discussed. The extreme high energy part of the equivalent photon spectrum leads to hard photon-parton reactions. As a potential tool to investigate the gluon distribution function of nucleons, thee q anti q production via the γg fusion in ultrarelativistic heavy ion collisions is studied. It is the purpose of this work to investigate how photon-photon and photon-hadron reactions in relativistic heavy ion collisions may contribute to the understanding of QCD and the standard model. (orig.) [de

  11. Neutron spectra, recoil momenta and PI0 production cross sections for reactions induced by 10-100 MeV/nucleon heavy ions

    International Nuclear Information System (INIS)

    Blann, M.

    1985-08-01

    The Boltzmann master equation model has been applied to the question of precompound nucleon de-excitation of reactions induced by 10 to 100 MeV/nucleon (c.m.) heavy ions. Test systems of 16 O + 60 Ni and 27 Al + 86 Kr were selected. Experimental neutron spectra in coincidence with evaporation residue and fission fragments from the 20 Ne + 165 Ho system (due to Holub, et al.) were reproduced quite well by the master equation with exciton numbers between 20 and 23. Results show major fractions of the excitation and up to 35 nucleons removed during the coalescence-equilibration period. The linear momentum transfer predicted by the master equation is shown to be in good agreement with a broad range of data. Extension of the master equation to predict sub-threshold PI 0 production cross sections is shown to give satisfactory agreement with a large number of experimental results. 48 refs., 8 figs., 7 tabs

  12. Relativistic heavy ion research

    International Nuclear Information System (INIS)

    1992-01-01

    Experimental work is reported on the following topics: transverse energy production in 10.7-GeV/c/u Au on Au collisions; first results on delta ray production and charged particle multiplicities with the Au beam at 10.7 GeV/c/A; preliminary studies on the feasibility of flow measurement with the E814 participant calorimeter; preliminary results from the E877 telescope; and low-p t baryon distribution in Si+Al, Pb collisions at the AGS. Then the status of the Hadronic Calorimeter project of AGS Experiment E864 (ECOS--Exotic Composite Object Spectrometer) is reviewed. Next, the same is done for work of the STAR RHIC collaboration (Silicon Vertex Tracker (SVT) project evolution and development in FY92, SVT software results from 1992, SVT instrumentation, FY93 SVT pion test beam). The instrumentation section deals with the design and installation of a target rapidity telescope for BNL experiment 814/877 and a repair scheme for the E814/E877 participant calorimeter. Finally, the theory part addresses bosonic kinetics: thermalization of mesons and the pion p perpendicular spectrum in ultrarelativistic heavy-ion collisions and non-equilibrium properties of hadronic mixtures

  13. Physics of Ultrarelativistic Heavy Ions

    International Nuclear Information System (INIS)

    Giubellino, P.

    1996-01-01

    This paper is devoted to a general presentation of the physics of Ultrarelativistic Heavy Ions, as seen from the experimentalist close-quote s point of view. The aim of this research is the study of nuclear matter under extreme conditions of temperature and pressure, extending in this way our understanding of the strong interactions in general, and of colour confinement in particular. This young field of Physics has been growing rapidly in the past years, and any attempt to cover it in few pages will be rather sketchy and many important aspects will have to be left out. I will mainly try to cover the general motivations to undertake this study, and just mention the experimental challenges to be faced, the results from the experiments at CERN and BNL, and finally the fascinating program ahead of us, with a glimpse at the CERN LHC used as a heavy-ion collider. copyright 1996 American Institute of Physics

  14. Radiation from heavy ion collisions

    International Nuclear Information System (INIS)

    Kast, J.R.; Lee, Y.K.

    1975-01-01

    A study of x rays produced in heavy ion collisions has led to a search for molecular orbital x rays, concentrating on 35 Cl ions on Al, NaCl, and C targets. Preliminary analysis of the angular dependence of continuum x rays has tentatively identified quasi-molecular K x rays. Other work completed and in progress is discussed. (3 figures) (U.S.)

  15. Heavy-ion microscopy

    International Nuclear Information System (INIS)

    Kraft, G.; Yang, T.C.H.; Richards, T.; Tobias, C.A.

    1980-01-01

    This chapter briefly describes the techniques of optical microscopy, scanning and transmission electron microscopy, soft x-ray microscopy and compares these latter techniques with heavy-ion microscopy. The resolution obtained with these various types of microscopy are compared and the influence of the etching procedure on total resolution is discussed. Several micrographs of mammalian cells are included

  16. Relativisitic heavy ion collisions

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1987-01-01

    Some of the objectives and observables of Relativistic Heavy Ion Physics are presented. The first experimental results from oxygen interactions at CERN, 200 GeV/c per nucleon, and BNL, 14.5 GeV/c per nucleon are shown. The data indicate more energy emission than was originally predicted. 25 refs., 19 figs

  17. Heavy-ion radiography and heavy-ion computed tomography

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Holley, W.R.; McFarland, E.W.; Tobias, C.a.

    1982-02-01

    Heavy-ion projection and CT radiography is being developed into a safe, low-dose, noninvasive radiological procedure that can quantitate and image small density differences in human tissues. The applications to heavy-ion mammography and heavy-ion CT imaging of the brain in clinical patients suggest their potential value in cancer diagnosis

  18. Sulfur hexafluoride purification from mixtures with air: a process feasibility study for the Holifield Heavy Ion Research Facility

    International Nuclear Information System (INIS)

    Perona, J.J.

    1979-01-01

    A preliminary feasibility study was made for the purification of SF 6 vapor contaminated with air for application at the Holifield Heavy Ion Research Facility. Liquefaction appears to be a good way to recover about 90% of the SF 6 if it is badly contaminated (15% air), and even greater recovery will be possible for mixtures containing less air. Where liquefaction is insufficient alone, adsorption of SF 6 on activated carbon at -50 0 F looks promising. Two carbon beds each containing about 500 lb of carbon should be sufficient. The refrigeration system for liquefaction and adsorption would have a capacity of about 2 tons. As alternatives, the use of molecular sieves to trap out the air was investigated, but such a bed would require at least 15,000 lb of molecular sieves and very long cycle times. A large-scale desublimer was investigated and appears workable but would require some development work to permit design work to proceed with confidence

  19. Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Kitagawa, A.; Drentje, A. G.; Fujita, T.; Muramatsu, M. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Fukushima, K.; Shiraishi, N.; Suzuki, T.; Takahashi, K.; Takasugi, W. [Accelerator Engineering Corporation, Chiba (Japan); Biri, S.; Rácz, R. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Kato, Y. [Graduate School of Engineering, Osaka University, Osaka (Japan); Uchida, T.; Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe (Japan)

    2016-02-15

    With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex.

  20. Heavy-ion mammography and breast cancer

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Tobias, C.A.; Capp, M.P.; Holley, W.R.; Woodruff, K.H.; Sickles, E.A.

    1980-01-01

    Heavy-ion radiography is a new diagnostic imaging technique developed in our laboratory that produces superior density resolution at low radiation doses. Heavy-ion mammography has now emerged as a low-dose, safe, reliable, noninvasive diagnostic radiological procedure that can quantitate and image very small differences in soft tissue densities in the breast tissues of patients with clinical breast disease. The improved density resolution of heavy-ion mammography over conventional X-ray mammography and breast xerography provides the potential of detecting small breast cancers of less than 1 cm diameter. The radiation dose to the breast from carbon-ion mammorgraphy is about 50 mrad or less, and can potentially be only a fraction of this level. The results of the present clinical trial in progress of heavy-ion mammography in 37 patients, thus far studied, are extremely encouraging, and warrant continued study for application to the early diagnosis of breast cancer in women

  1. Study of relativistic heavy-ion interactions and antiproton annihilation data

    International Nuclear Information System (INIS)

    Ghosh, D.; Roy, J.; Sengupta, R.

    1986-01-01

    The characteristics of 12 C-AgBr interaction at 4.5-GeV · c -1 · nucleon -1 incident momentum are studied by means of the photoemulsion technique, to search for shock-wave phenomena. The angular distributions indicate an anisotropic process in the nuclear matter. The results are compared with the antiproton -AgBr reaction observations of Breivik et al. (1983) at 1.4 GeV · c -1

  2. Heavy ion collisions with the ATLAS detector

    International Nuclear Information System (INIS)

    Nevski, Pavel

    2004-01-01

    The ATLAS detector is designed to study high-p T physics in proton-proton collisions at the LHC design luminosity. The detector capabilities for heavy-ion physics are now being evaluated. This paper reports on a preliminary assessment of the baseline ATLAS detector potential for heavy-ion physics. The ATLAS sensitivity to some of the expected signatures from the quark-gluon plasma (e.g. jet quenching, Υ suppression) is discussed. (orig.)

  3. Research in heavy-ion nuclear physics

    International Nuclear Information System (INIS)

    Sanders, S.J.; Prosser, F.W.

    1992-01-01

    This report discusses the following topics: Fusion-fission in light nuclear systems; High-resolution Q-value measurement for the 24 Mg+ 24 Mg reaction; Heavy-ion reactions and limits to fusion; and Hybrid MWPC-Bragg curve detector development

  4. Hadron chemistry in heavy ion collisions

    International Nuclear Information System (INIS)

    Montvay, I.; Zimanyi, J.

    1978-06-01

    In the models for energetic heavy ion reactions it is assumed that during the reaction a hot and dense nuclear matter, a fireball is formed from all or a part of nucleons of the target and projectile nuclei. The process is similar to the chemical processes leading to dynamical equilibrium. The relaxation times necessary to establish ''chemical'' equilibrium among different hadrons in hot, dense hadronic matter is deducted in a statistical model. Consequences for heavy ion collisions are discussed. The possibility of Bose-Einstein pion condensation around the break-up time of the nuclear fireball is pointed out. (D.P.)

  5. Contribution of DIAMANT and EUROGAM detectors association to the study of heavy ion-induced fusion-evaporation reactions. Application to the de-excitation study of 90Ru compound nucleus formed in the 32S + 58Ni reaction at 120 MeV

    International Nuclear Information System (INIS)

    Bourgine, Frederic

    1996-01-01

    For the first time, the sensitivity of statistical evaporation model has been established in detail from 1 H and 4 He energy distributions analysis for different exit channels. The association of the light charged particle multidetector DIAMANT and the γ-spectrometer EUROGAM II shows that precise study of the compound nucleus high spin states deexcitation can be done for small particle channels. These channels are fed by the biggest angular momentum values of the compound nucleus. The analysis of pα channel in 32 S + 58 Ni at 120 MeV reaction exhibits that a particles have an energy distribution which leads to an entry region of the residual nucleus 85 Nb parallel to the yrast line. (author) [fr

  6. Proximity approach to study fusion probabilities in heavy-ion collisions

    International Nuclear Information System (INIS)

    Raj Kumari

    2013-01-01

    The fusion cross-sections at the sub-barrier energies are found to be enhanced compared to the predictions of the barrier penetration model. The aim is to test Bass 80, Aage Winther (AW) 95, Denisov DP, Proximity 2010 and Skyrme Energy Density Formalism (SEDF) at energies above as well as below barrier height. For the present systematic study, the fusion probabilities for the reactions of 28 Si+ 24,26 Mg 30 Si+ 24 Mg and 28,30 Si+ 58,62 Ni have been calculated

  7. Heavy-ion radiography

    International Nuclear Information System (INIS)

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

    1981-01-01

    Heavy-particle radiography has clinical potential as a newly developed noninvasive low-dose imaging procedure that provides 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 for medicine utilizes heavy-ion radiography for low-dose mammography, for treatment planning for cancer patients, and for imaging and accurate densitometry of skeletal structures, brain and spinal neoplasms, and the heart. The potential of heavy-ion imaging, and particularly reconstruction tomography, is now proving to be an adjunct to existing diagnostic imaging procedures in medicine, both for applications to the diagnosis, management and treatment of clinical cancer in man, and for the early detection of small soft-tissue tumors at low radiation dose

  8. Heavy ion fusion III

    International Nuclear Information System (INIS)

    Hammer, D.; Max, C.; Perkins, F.; Rosenbluth, M.

    1987-03-01

    This report updates Heavy Ion Fusion, JSR-82-302, dated January, 1983. During the last four years, program management and direction has been changed and the overall Inertial Confinement Program has been reviewed. This report therefore concentrates on accelerator physics issues, how the program has addressed those issues during the last four years, and how it will be addressing them in the future. 8 refs., 3 figs

  9. Relativistic heavy ion physics

    International Nuclear Information System (INIS)

    Hansen, O.

    1985-01-01

    In the fall of 1986 beams of heavy ions up to A ∼ 40 at total energies up to E ∼ 225 GeV/-nucleon will become available for experiments at CERN (60 and 225 GeV/nucleon) and at Brookhaven (15.5 GeV/nucleon). Are these energies interesting in relation to the ideas of creating quark deconfinement? An energy consideration of the planned experiments is presented, as well as a description of the experimental arrangement. (Auth.)

  10. Heavy ion fusion

    International Nuclear Information System (INIS)

    Hofmann, Ingo

    1993-01-01

    With controlled thermonuclear fusion holding out the possibility of a prolific and clean new source of energy, the goal remains elusive after many years of continual effort. While the conventional Tokamak route with magnetic confinement continues to hit the headlines, other alternatives are now becoming competitive. One possible solution is to confine the thermonuclear fuel pellet by high power beams. Current research and perspectives for future work in such inertial confinement was the subject of the 'Prospects for Heavy Ion Fusion' European Research Conference held in Aghia Pelaghia, Crete, last year. Its main focus was on the potential of heavy ion accelerators as well as recent advances in target physics with high power lasers and light ion beams. Carlo Rubbia declared that high energy accelerators, with their high efficiency, are the most promising approach to economical fusion energy production. However the need for cost saving in the driver accelerator requires new ideas in target design tailored to the particularities of heavy ion beams, which need to be pushed to the limits of high current and phase space density at the same time

  11. Quantum mechanical studies of heavy ion scattering processes. Progress report, July 15, 1983-March, 1984

    International Nuclear Information System (INIS)

    Heil, T.G.

    1984-01-01

    The research done under this contract should provide valuable contributions to our understanding of atomic collision processes. The essence of this project is the description of low energy atomic collision process using molecular states formed by the collision partners in the interaction region. Over the eight months that this contract has been in effect, significant progress has been made on both fundamental and applied levels. On the most basic level, we have recently developed a new diabatic representation of the scattering which has none of the defects associated with the most commonly used formulation of Smith. This may prove to be of great importance since a proper diabatic description is thought to be a more reasonable representation of the actual physical scattering process than the adiabatic description. It should be noted that there is a great deal of controversy surrounding the word proper but our new formulation satisfies most, if not all, criteria for diabatic states. In addition, we have carried out or initiated theoretical studies on a number of atomic scattering processes involving charge transfer reactions and proton-induced fine-structure transitions. Our calculations of differential scattering cross sections for low energy charge transfer reaction should be of particular importance. A number of experimental groups are now proposing to measure these cross sections which our calculations predict should have large, striking features. Such comparisons would provide valuable tests of the theory of low energy atomic collision processes on a more fundamental level than previous comparisons of the total cross sections

  12. Nuclear clusters as a probe for expansion flow in heavy ion reactions at (10 endash 15)A GeV

    International Nuclear Information System (INIS)

    Mattiello, R.; Mattiello, R.; Sorge, H.; Stoecker, H.; Greiner, W.

    1997-01-01

    A phase space coalescence description based on the Wigner-function method for cluster formation in relativistic nucleus-nucleus collisions is presented. The momentum distributions of nuclear clusters d, t, and He are predicted for central Au(11.6A GeV)Au and Si(14.6A GeV)Si reactions in the framework of the relativistic quantum molecular dynamics transport approach. Transverse expansion leads to a strong shoulder-arm shape and different inverse slope parameters in the transverse spectra of nuclear clusters deviating markedly from thermal distributions. A clear open-quotes bounce-off close-quote close-quote event shape is seen: The averaged transverse flow velocities in the reaction plane are for clusters larger than for protons. The cluster yields, particularly at low p t at midrapidities, and the in-plane (anti)flow of clusters and pions change if suitably strong baryon potential interactions are included. This allows one to study the transient pressure at high density via the event shape analysis of nucleons, nucleon clusters, and other hadrons. copyright 1997 The American Physical Society

  13. Measurement of the total reaction cross section for interactions between heavy ions (application to the system 12C+12C at 112MeV)

    International Nuclear Information System (INIS)

    Cherkaoui-Tadili, R.

    1982-01-01

    The total reaction cross-section σsub(R) for interactions between heavy ions is predicted to decrease rapidly with the energy of the incident projectile over the energy range 10 MeV/A - 100 MeV/A. We present here an experimental met σsub(R) to test the model based predictions. The method consists in counting the number of all incoming projectiles and the number of out going projectiles that did not interact with the target. The difference between these two numbers corresponds to the number of particles that reacted with the target nuclei and is therefore proportional to σsub(R). Values of σsub(R) have been measured for the system 12 C + 12 C at two incident energies of 112 MeV and 996 MeV. The results of 1444 +- 70 (112 MeV) and 994 +- 50 (996 MeV) show a total reaction cross-section decreasing with energy as predicted from the Glauber model and optical model fits to elastic scattering [fr

  14. Summary of the heavy ion physics sessions at Lake Louise

    International Nuclear Information System (INIS)

    Harris, J.W.

    1986-01-01

    This talk is a summary of the reports on heavy ion reactions which were given in this conference, Intersections Between Particle and Nuclear Physics . In particular, quark degrees of freedom in nuclear matter are a focus in these discussions of heavy ion physics

  15. Proceedings of the international conference on dynamical properties of heavy-ion reactions held at the University of the Witwatersrand, Johannesburg, South Africa, August 1-3, 1978. v. 4

    International Nuclear Information System (INIS)

    Sellschop, J.P.F.; Toepffer, C.; Lemmer, R.H.; Engelbrecht, C.A.

    1978-01-01

    At this post-conference school invited lectures on 'Topical themes in heavy-ion scattering' were delivered. The following topics were discussed; 1) the measurement of magnetic moments of nuclear states of high angular momentum; 2) nuclei at very high angular momentum; 3) multi-step direct reaction analysis of deep inelastic spectra in nuclear reactions: 4) experiments relating to quantum electrodynamics of strong field and 5) the role of deep inelastic processes in nuclear physics

  16. Comparative study of the excitation functions of nuclear reactions induced by light ions (protons and α) and heavy ions (Ne, Ca, Ar) and, after neutron evaporation, leading to platinum and polonium isotopes. Analysis by de-excitation programme allowing for the angular momentum and fission

    International Nuclear Information System (INIS)

    Lagarde, Brigitte.

    1979-01-01

    This work is a study on the de-excitation of heavy nuclei from the Pt - Po area obtained by the complete fusion of various projectiles (p, 3 He, 4 He, 20 Ne, 40 Ar and 40 Ca) and of various targets. The aim was to create from different couples the same compound nucleus of a mass equal to the sum of the masses of the component parts. The excitation energy of the system thus created can vary between 60 and 120 MeV. The experimental study of one or more particular de-excitation channels performed by measuring the cross sections of residual nuclei production for various bombardment energies is a very conventional approach. An in depth examination was made of the effect of the angular momentum given to the compound nucleus by the input channel to the de-excitation processes. Now the population of orbital angular momenta depends essentially on the mass of the projectile at equal velocities. Consequently, the utilization of projectiles extending from the proton to mass 40 covers a wide range. Decay by neutrons is not the only de-excitation method. Fission has a significant role particularly for the Po's and consequently this strongly diminishes the probability (P,xn). The decay of (α,xn) when going from the compound nucleus of 204 Po to 182 Pt makes it possble to evaluate the importance of the phenomenon and to have an item of experimental information that can be compared to a theoretical calculation. Theoretical calculations using the 'ALICE' code which expresses schematically the reduction in level densities by subtracting from the excitation energy a rotation energy and the 'JULIAN' code which uses a more accurate level density calculation and takes into account the gamma emission competing with the emission of neutrons show that the last programme reports the experimental results whereas the 'ALICE' code does not enable a consistent presentation to be made of all the results by light and heavy ions. Finally, it had to be agreed that the fission does not intervene as

  17. Particle and heavy ion transport code system; PHITS

    International Nuclear Information System (INIS)

    Niita, Koji

    2004-01-01

    Intermediate and high energy nuclear data are strongly required in design study of many facilities such as accelerator-driven systems, intense pulse spallation neutron sources, and also in medical and space technology. There is, however, few evaluated nuclear data of intermediate and high energy nuclear reactions. Therefore, we have to use some models or systematics for the cross sections, which are essential ingredients of high energy particle and heavy ion transport code to estimate neutron yield, heat deposition and many other quantities of the transport phenomena in materials. We have developed general purpose particle and heavy ion transport Monte Carlo code system, PHITS (Particle and Heavy Ion Transport code System), based on the NMTC/JAM code by the collaboration of Tohoku University, JAERI and RIST. The PHITS has three important ingredients which enable us to calculate (1) high energy nuclear reactions up to 200 GeV, (2) heavy ion collision and its transport in material, (3) low energy neutron transport based on the evaluated nuclear data. In the PHITS, the cross sections of high energy nuclear reactions are obtained by JAM model. JAM (Jet AA Microscopic Transport Model) is a hadronic cascade model, which explicitly treats all established hadronic states including resonances and all hadron-hadron cross sections parametrized based on the resonance model and string model by fitting the available experimental data. The PHITS can describe the transport of heavy ions and their collisions by making use of JQMD and SPAR code. The JQMD (JAERI Quantum Molecular Dynamics) is a simulation code for nucleus nucleus collisions based on the molecular dynamics. The SPAR code is widely used to calculate the stopping powers and ranges for charged particles and heavy ions. The PHITS has included some part of MCNP4C code, by which the transport of low energy neutron, photon and electron based on the evaluated nuclear data can be described. Furthermore, the high energy nuclear

  18. Deeply inelastic transfer reactions induced by heavy ions in rare earth targets. II. Interpretation of experimental data

    International Nuclear Information System (INIS)

    Rivet, M.F.; Bimbot, R.; Ngo, C.

    1979-01-01

    The experimental angular distributions and cross sections for a series of deeply inelastic transfer reactions induced by various projectiles in rare earth targets have been interpreted using a model which includes a dynamical coupling between relative motion and mass asymmetry and treats statistical fluctuations. As the transfer reactions considered correspond to an increase of the potential energy of the composite system their observation is mainly due to fluctuations. The calculation reproduces correctly the angular distributions, but the cross sections are underestimated. Several effects are discussed which may increase these cross sections and are neglected in the calculation

  19. Study of mass asymmetry effect in the entrance channel for deep inelastic collisions between heavy ions

    International Nuclear Information System (INIS)

    Agarwal, S.K.

    1980-01-01

    The reactions ( 52 Cr+ 56 Fe) and ( 16 O+ 92 Mo) were studied extensively to learn about the influence of the mass asymmetry of the entrance channel on Deep Inelastic Collisions (DIC). These two systems have very different entrance channel asymmetry but both of them lead to the same ensemble of nucleons. The incident energies were choosen to be 265 MeV for Cr and 187 MeV for O so that the maximum angular momentum is the same in both the cases. The experimental results of the quasi-symmetric system (Cr+Fe) show that a large number of fragments have the characteristic properties of fission fragments. However, comparison of these results with those of an asymmetric system (O+Mo), forming the same compound nucleus with higher excitation energy, leads to think that these events can not be accounted for fission. It has been shown that these events could be considered as DIC products. The distributions of different multidifferential observables were reproduced with the help of a diffusion model, and with the condition of introducing a notion of half life time of the composite system. The half-life, thus calculated, seems to vary as a function of mass asymmetry of the entrance channel: 20.10 -22 S for the system Cr+Fe, 2.10 -22 S for the system O+Mo and 10.10 -22 S for a third system 20 Ca+ 64 Ni which has an intermediate mass asymmetry. Further it seems that the evaporation residue cross section in symmetric systems is far less than what we can expect from classical calculations [fr

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

    International Nuclear Information System (INIS)

    Nyiri, Agnes

    2005-01-01

    -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