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Sample records for heavy-ion induced fission

  1. Nuclear fission induced by heavy ions

    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

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

    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

  3. Recent advances in heavy-ion-induced fission

    Plasil, F.

    1984-01-01

    Three topics are discussed. The first deals with results that have been published recently on angular-momentum-dependent fission barriers. They are discussed because of the significance that we attach to them. We feel that, after a decade of study and controversy, we have arrived at a quantitative understanding of the competition between heavy-ion-induced fission and particle emission from compound nuclei at relatively low bombarding energies. The second topic concerns the extension of our heavy-ion-induced fission studies to higher energies. It is clear that in this regime the effects, both of fission following incomplete fusion and of extra-push requirements, need to be considered. Finally, discussed are our recent conclusions concerning the fissionlike decay of products from reactions between two 58 Ni nuclei at an incident energy, E/A, of 15.3 MeV, as well as the impact of our findings on the conclusions drawn from previous, similar measurements. 39 references

  4. Recent results in heavy-ion-induced fission

    Plasil, F.; Awes, T.C.; Cheynis, B.

    1984-01-01

    A systematic investigation of angular-momentum-dependent fission barriers has been completed. Fission excitation functions were measured for the compound nuclei 153 Tb, 158 Er, 181 Re, 186 Os, and 204 206 208 210 Po. In the case of 153 Tb and 181 Re, evaporation residue cross sections were also measured. With the exception of some of the Po systems, two to five different reactions were used to produce the same compound nucleus with projectiles ranging from 9 Be to 64 Ni. 12 C reactions with 174 Yb, 198 Pt, and 238 U at energies from 95 to 291 MeV; 16 O reactions with 142 Nd, 170 Er, 192 Os, and 238 U at energies from 140 to 315 Mev; 32 S reactions with 126 Te, 144 Nd, and 238 U at energies from 350 to 700 MeV; and 58 Ni reactions with 96 Zr, 116 Cd, and 238 U at 352 and 875 MeV have also been studied. Also, fission fragment angular distributions were measured for the above 12 C- and 16 O-induced reactions. The results were analyzed in terms of saddle-point moments of inertia obtained from the RFRM

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

    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

  6. A new prompt heavy-ion-induced fission mode

    finement of nuclear systems, methods which are still sometimes used in ... Another type of essentially binary nuclear disintegration of projectile-like fragment ... While the field of nuclear fission research still has a range of questions to investigate, it .... momentum, qualitative to semiquantitative expectations can be formulated ...

  7. The Effect of Stiffness Parameter on Mass Distribution in Heavy-Ion Induced Fission

    Soheyli, Saeed; Khalil Khalili, Morteza; Ashrafi, Ghazaaleh

    2018-06-01

    The stiffness parameter of the composite system has been studied for several heavy-ion induced fission reactions without the contribution of non-compound nucleus fission events. In this research, determination of the stiffness parameter is based on the comparison between the experimental data on the mass widths of fission fragments and those predicted by the statistical model treatments at the saddle and scission points. Analysis of the results shows that for the induced fission reactions of different targets by the same projectile, the stiffness parameter of the composite system decreases with increasing the fissility parameter, as well as with increasing the mass number of the compound nucleus. This parameter also exhibits a similar behavior for the reactions of a given target induced by different projectiles. As expected, nearly same stiffness values are obtained for different reactions leading to the same compound nucleus.

  8. Heavy ion induced fission between 10 and 100 MeV/u

    Steckmeyer, J.C.; Tamain, B.

    1986-05-01

    Heavy ion induced fission between 10 and 100 MeV/u is discussed. It is shown that one can obtain information on fusion limits and on typical times characterizing nuclear matter. Intermediate energy heavy ions can be used to build very excited fusion nuclei. Section I shows that fission can then be used as a tool to test the fusion mechanism and to discover what are the extreme limits concerning fusion and hot nuclei formation. In section II, it is shown that when very hot nuclei are built, fission evaporation competition cannot any longer be fully described in the usual way by the statistical model. New features as dynamical aspects or cluster evaporation modify dramatically the landscape. Concerning the detailed fission properties of very hot nuclei (for instance fragments properties), no strong deviations from the already know systematics has been obtained. However, very few detailed studies are yet available and a clear experimental program has to be developed in order to progress. From a theoretical point of view, it is rather necessary to described fission and evaporation is an unified way

  9. Manifestation of transient effects in fission induced by relativistic heavy-ion collisions

    Jurado, B.; Schmitt, C.; Schmidt, K.H.; Benlliure, J. [Universidad de Santiago de Compostela (Spain); Junghans, A.R. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany)

    2004-03-01

    We examine the manifestation of transient effects in fission by analysing experimental data where fission is induced by peripheral heavy-ion collisions at relativistic energies. Available total nuclear fission cross sections of {sup 238}U at1.A GeV on gold and uranium targets are compared with a nuclear-reaction code, where transient effects in fission are modelled using different approximations to the numerical time-dependent fission-decay width: a new analytical description based on the solution of the Fokker-Planck equation and two widely used but less realistic descriptions, a step function and an exponential-like function. The experimental data are only reproduced when transient effects are considered. The deduced value of the dissipation strength {beta} depends strongly on the approximation applied for the time-dependent fission-decay width and is estimated to be of the order of 2 x 10{sup 21} s{sup -1}. A careful analysis sheds severe doubts on the use of the exponential-like in-growth function largely used in the past. Finally, we discuss which should be the characteristics of experimental observables to be most sensitive to transient effects in fission. (orig.)

  10. New signatures on dissipation from fission induced by relativistic heavy-ion collisions

    Jurado, B.; Schmitt, C.; Schmidt, K.H.; Enqvist, T.; Kelic, A.; Rejmund, F.; Benlliure, J.; Junghans, A.R.

    2004-03-01

    Fissile nuclei with small shape distortion relative to the ground-state deformation and with low angular momentum were produced in peripheral heavy-ion collisions. Under the conditions of small shape distortions and low angular momentum, the theoretical description of the fission process can be considerably simplified, and the relevant information on dissipation can be better extracted than in conventional experiments based on fusion-fission reactions. In addition, this experimental approach induces very high excitation energies, a condition necessary to observe transient effects. The experimental data were taken at GSI using a set-up especially conceived for fission studies in inverse kinematics. This set-up allowed determining three observables whose sensitivity to dissipation was investigated for the first time: the total fission cross sections of 238 U at 1 A GeV as a function of the target mass, and, for the reaction of 238 U at 1 A GeV on a (CH 2 ) n target, the partial fission cross sections and the partial charge distributions of the fission fragments. The comparison of the new experimental data with a reaction code adapted to the conditions of the reactions investigated leads to clear conclusions on the strength of dissipation at small deformation where the existing results are rather contradictory. (orig.)

  11. New signatures on dissipation from fission induced by relativistic heavy-ion collisions

    Jurado, B.; Schmitt, C.; Schmidt, K.H.; Enqvist, T.; Kelic, A.; Rejmund, F.; Benlliure, J. [Universidad de Santiago de Compostela (Spain); Junghans, A.R. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany)

    2004-03-01

    Fissile nuclei with small shape distortion relative to the ground-state deformation and with low angular momentum were produced in peripheral heavy-ion collisions. Under the conditions of small shape distortions and low angular momentum, the theoretical description of the fission process can be considerably simplified, and the relevant information on dissipation can be better extracted than in conventional experiments based on fusion-fission reactions. In addition, this experimental approach induces very high excitation energies, a condition necessary to observe transient effects. The experimental data were taken at GSI using a set-up especially conceived for fission studies in inverse kinematics. This set-up allowed determining three observables whose sensitivity to dissipation was investigated for the first time: the total fission cross sections of {sup 238}U at 1 A GeV as a function of the target mass, and, for the reaction of {sup 238}U at 1 A GeV on a (CH{sub 2}){sub n} target, the partial fission cross sections and the partial charge distributions of the fission fragments. The comparison of the new experimental data with a reaction code adapted to the conditions of the reactions investigated leads to clear conclusions on the strength of dissipation at small deformation where the existing results are rather contradictory. (orig.)

  12. Coulomb fission and transfer fission at heavy ion collisions

    Himmele, G.

    1981-01-01

    In the present thesis the first direct evidence of nuclear fission after inelastic scattering of heavy ions (sup(183,184)W, 152 Sm → 238 U; 184 W → 232 Th; 184 W, 232 Th → 248 Cm) is reported. Experiments which were performed at the UNILAC of the Gesellschaft fuer Schwerionenforschung in Darmstadt show the observed heavy ion induced fission possesses significant properties of the Coulomb fission. The observed dependence of the fission probability for inelastic scattering on the projectile charge proves that the nuclear fission is mediated by the electromagnetic interaction between heavy ions. This result suggests moreover a multiple Coulomb-excitation preceding the fission. Model calculations give a first indication, that the Coulomb fission proceeds mainly from the higher β phonons. In the irradiation with 184 W the fission probability of 232 Th is for all incident energies about 40% smaller that at 238 U. The target dependence of the Coulomb fission however doesn't allow, to give quantitative statements about the position and B(E2)-values of higher lying β phonons. (orig./HSI) [de

  13. Different fission behavior induced by heavy ion central and peripheral collisions

    Wu Enjiu; Zheng Jiwen; Xiao Zhigang; Zhang Chun; Tan Jilian; Yin Shuzhi; Wang Sufang; Jin Genming; Yin Xu; Song Mingtao; Jin Weiyang; Peng Xingping; Li Zuyu; Wu Heyu; He Zhiyong; Jiang Dongxing; Qian Xing

    2000-01-01

    Correlated fission fragments from the 40 Ar + 209 Bi reaction and their further correlation with α particles have been studied for peripheral and central collisions simultaneously. The existence of different fission behavior of hot nuclei formed in central and peripheral collisions was found from the systematic analysis of the mass and energy distributions of fission fragments as a function of the initial temperature of hot fissioning nuclei

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

    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

  15. Dynamics in heavy ion fusion and fission

    Bjoernholm, S.

    1972-01-01

    Dynamical aspects of heavy ion fussion and fission, mainly the aspect of damping which is meant as the dissipation of kinetic energy and the aspect of the effective mass of the fission motion, are discussed. Two categories of evidence of damping effects are given. One relates to the damping of the fission motion for the ground state shape and for the isomeric more elongated shape. The other relates to the damping of the fission motion from the last barrier to the scission point. The dependence of the effective mass associated with the fission motion on the deormation of nucleus is shown. As the elongation of the nucleus increases the effective mass of the fission motion varies strongly from being about forty times greater than the reduced mass in the beta-vibrational state of the ground state shape to being equal to the reduced mass in the moment of scission. Damping effects are expected to be propartional to the difference between the effective mass and the reduced mass. It is concluded that the damping in fussion reactions is relatively weak for lighter products and quite strong for superheavy products like 236 U or 252 Cf. (S.B.)

  16. Pre-scission particle and gamma-ray emission in heavy-ion induced fission

    Newton, J.O.

    1989-02-01

    An introduction is given to the physics of the equilibrium transition model and of dissipative nuclear dynamics. Experimental data on pre-scission particle and gamma-ray emission and their interpretation are reviewed. They appear to indicate overdamped motion of the nuclear fluid. A time scale for compound-nucleus fission of about 30x10 -21 sec or greater is indicated, whilst that for quasi- or fast-fission is somewhat shorter. 99 refs., 28 figs

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

    A Kramers-modified statistical model is used to calculate the cross-section of the evap- oration residue, fission ... where ρCN and ρsad are the level density of the compound nucleus at the ground and saddle points ... where P(K) is the probability that the system is in a given K. P(K) = T ..... time to be emitted before fission.

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

    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.

  19. Dissipation of the tilting degree of freedom in heavy-ion-induced fission from four-dimensional Langevin dynamics

    Nadtochy, P.N. [Omsk State Technical University, Omsk (Russian Federation); Ryabov, E.G.; Cheredov, A.V.; Adeev, G.D. [Omsk State University, Omsk (Russian Federation)

    2016-10-15

    A stochastic approach based on four-dimensional Langevin fission dynamics is applied to the calculation of a wide set of experimental observables of excited compound nuclei from {sup 199}Pb to {sup 248}Cf formed in reactions induced by heavy ions. In the model under investigation, the tilting degree of freedom (K coordinate) representing the projection of the total angular momentum onto the symmetry axis of the nucleus is taken into account in addition to three collective shape coordinates introduced on the basis of {c,h,α} parametrization. The evolution of the K coordinate is described by means of the Langevin equation in the overdamped regime. The friction tensor for the shape collective coordinates is calculated under the assumption of the modified version of the one-body dissipation mechanism, where the reduction coefficient k{sub s} of the contribution from the ''wall'' formula is introduced. The calculations are performed both for the constant values of the coefficient k{sub s} and for the coordinate-dependent reduction coefficient k{sub s}(q) which is found on the basis of the ''chaos-weighted wall formula''. Different possibilities of the deformation-dependent dissipation coefficient (γ{sub K}) for the K coordinate are investigated. The presented results demonstrate that an impact of the k{sub s} and γ{sub K} parameters on the calculated observable fission characteristics can be selectively probed. It was found that it is possible to describe the experimental data consistently with the deformation-dependent γ{sub K}(q) coefficient for shapes featuring a neck, which predicts quite small values of γ{sub K} = 0.0077 (MeV zs){sup -1/2} and constant γ{sub K} = 0.1 -0.4 (MeV zs){sup -1/2} for compact shapes featuring no neck. (orig.)

  20. Fission in intermediate energy heavy ion reactions

    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.)

  1. Fission in intermediate energy heavy ion reactions

    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

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

    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.

  3. Mass and kinetic-energy distributions of fragments formed in the heavy-ion-induced fission of 208Po

    Cuninghame, J.G.; Goodall, J.A.B.

    1980-01-01

    Fission fragments following the decay of a 208 Po compound nucleus have been observed by using radiochemical and particle-counting techniques. The (α+ 204 Pb), ( 12 C+ 196 Pt) and ( 16 O+ 192 Os) reactions were studied at two or three bombarding energies, covering overlapping ranges of excitation energies. - Radiochemical separations of As, Br, Y, Nb, Tc, Ag, Sb and I isotopes were made from catcher foils sandwiching isotopic targets, and their isotopic yield distributions determined. The distributions are used to estimate the average number of neutrons associated with each fission event, including neutrons emitted before and after fission. - Prompt coincidence measurements of fragments are used to derive the overall mass and kinetic-energy distributions of primary fragments, taking into account the effects of pre- and post-fission neutron emission. The mass distributions are well fitted by the statistical theory, at a temperature corresponding to an excitation about 10 MeV above that at the saddle point. No evidence is found for an increase of kinetic-energy with increasing angular momentum of the compound nucleus. (author)

  4. Specific gene mutations induced by heavy ions

    Freeling, M.; Karoly, C.W.; Cheng, D.S.K.

    1980-01-01

    This report summarizes our heavy-ion research rationale, progress, and plans for the near future. The major project involves selecting a group of maize Adh1 mutants induced by heavy ions and correlating their altered behavior with altered DNA nucleotide sequences and sequence arrangements. This research requires merging the techniques of classical genetics and recombinant DNA technology. Our secondary projects involve (1) the use of the Adh gene in the fruit fly, Drosophila melanogaster, as a second system with which to quantify the sort of specific gene mutants induced by heavy ions as compared to x rays, and (2) the development of a maize Adh1 pollen in situ monitor for environmental mutagens

  5. Heavy ion induced mutation in arabidopsis

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

    1997-03-01

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

  6. Proceedings of the 12. International Symposium on Nuclear Physics - Heavy-Ion Collisions and Nuclear Fission - organized by the Technical University of Dresden, November 22-26, 1982 in Gaussig (GDR)

    Reif, R.; Teichert, J.

    1982-12-01

    The following problems in experimental and theoretical investigations of heavy-ion reactions and the dynamics of nuclear fission processes are discussed: (1) emission of fast light particles in heavy-ion collisions, preequilibrium effects; (2) dynamics of deep inelastic heavy-ion reactions; (3) selected topics in quasi-elastic heavy-ion collisions; and (4) collective transport theory for fission, cross sections and neutron spectra of fission. Problems of neutron induced reactions and nuclear data evaluation are also covered. (author)

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

    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

  8. Dynamics of nuclear fission and heavy-ion reactions

    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

  9. Semiclassical approach to sequential fission in peripheral heavy-ion collisions

    Strazzeri Andrea

    2016-01-01

    Full Text Available A closed-form theoretical approach describing in a single picture both the evaporation component and the fast nonequilibrium component of the sequential fission of projectilelike fragments in a semiperipheral heavy-ion collision is derived and then applied to the dynamical fission observed in the 124Sn+64Ni semiperipheral collision at 35A MeV. Information on opposite polarization effects of the fissioning projectilelike fragments and on their “formation-to-fast fission lifetimes” are obtained.

  10. Exclusion of nuclear forces in heavy-ion Coulomb excitation and Coulomb fission experiments

    Neese, R.E.; Guidry, M.W.

    1982-01-01

    A simple prescription for estimating the energy at which nuclear forces begin to play a role in heavy-ion Coulomb excitation and Coulomb fission experiments is presented. The method differs from most commonly used recipes in accounting for projectile and target nucleus deformation effects. Using a single adjustable parameter the formula reproduces the energy for the onset of Coulomb-nuclear interference effects for a broad range of heavy-ion systems. It is suggested that most Coulomb fission experiments which have been done involve both Coulomb and nuclear excitation processes and should more properly be termed Coulomb-nuclear fission experiments

  11. Stochastic approaches to dynamics of heavy ion collisions, the case of thermal fission

    Boilley, D.; Abe, Y.

    1994-01-01

    In order to study the influence of fluctuations on various phenomena linked to heavy ion collisions, a Langevin equation has been derived from a microscopic model. Parameters entering this equation are completely determined from microscopic quantities characterizing nuclear matter. This equation has been applied to various phenomena at intermediate energies. This paper focuses on large amplitude motions and especially thermal fission. Fission rate is calculated and compared to experimental results

  12. Fission before mass equilibration in heavy ion reactions

    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

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

    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

  14. Heavy-Ion-Induced Electronic Desorption of Gas from Metals

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

    2007-01-01

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

  15. Heavy-ion-induced, gate-rupture in power MOSFETs

    Fischer, T.A.

    1987-01-01

    A new, heavy-ion-induced, burnout mechanism has been experimentally observed in power metal-oxide-semiconductor field-effect transistors (MOSFETs). This mechanism occurs when a heavy, charged particle passes through the gate oxide region of n- or p-channel devices having sufficient gate-to-source or gate-to-drain bias. The gate-rupture leads to significant permanent degradation of the device. A proposed failure mechanism is discussed and experimentally verified. In addition, the absolute immunity of p-channel devices to heavy-ion-induced, semiconductor burnout is demonstrated and discussed along with new, non-destructive, burnout testing methods

  16. Tunneling process in heavy-ion fusion and fission

    Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kondratyev, V.; Bonasera, A.

    1998-10-01

    We present a model towards the many-body description of sub-barrier fusion and spontaneous fission based on the semiclassical Vlasov equation and the Feynman path integral method. We define suitable collective variables from the Vlasov solution and use the imaginary time technique for the dynamics below the Coulomb barrier. (author)

  17. Electron emission from solids induced by swift heavy ions

    Xiao Guoqing

    2000-01-01

    The recent progresses in experimental and theoretical studies of the collision between swift heavy ion and solids as well as electron emission induced by swift heavy ion in solids were briefly reviewed. Three models, Coulomb explosion, thermal spike and repulsive long-lived states, for interpreting the atomic displacements stimulated by the electronic energy loss were discussed. The experimental setup and methods for measuring the electron emission from solids were described. The signification deviation from a proportionality between total electron emission yields and electronic stopping power was found. Auger-electron and convoy-electron spectra are thought to be a probe for investigating the microscopic production mechanisms of the electronic irradiation-damage. Electron temperature and track potential at the center of nuclear tracks in C and polypropylene foils induced by 5 MeV/u heavy ions, which are related to the electronic excitation density in metals and insulators respectively, were extracted by measuring the high resolution electron spectra

  18. Heavy ion and proton-induced single event multiple upset

    Reed, R.A.; Carts, M.A.; Marshall, P.W.

    1997-01-01

    Individual ionizing heavy ion events are shown to cause two or more adjacent memory cells to change logic states in a high density CMOS SRAM. A majority of the upsets produced by normally incident heavy ions are due to single-particle events that causes a single cell to upset. However, for grazing angles a majority of the upsets produced by heavy-ion irradiation are due to single-particle events that cause two or more cells to change logic states. Experimental evidence of a single proton-induced spallation reaction that causes two adjacent memory cells to change logic states is presented. Results from a dual volume Monte-Carlo simulation code for proton-induced single-event multiple upsets are within a factor of three of experimental data for protons at normal incidence and 70 degrees

  19. Systematics of quasi-elastic processes induced by heavy ions

    Baltz, A.J.

    1976-01-01

    An attempt is made to delineate the areas in the systematics of quasi-elastic processes induced by heavy ions that are well described theoretically from the specific features that seem not to be understood. One- and two-particle transfer reactions are considered. A general systematic seen in transfer angular distribution data and theory, some successes and failures of the DWBA and coupled-channels theories in describing heavy-ion-reaction data, and the specific example 232 Th( 40 Ar,K) and implications for deep inelastic reactions with even heavier projectiles such as Kr and Xe are considered

  20. Heavy-ion radiation induced bystander effect in mice

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

    2012-07-01

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

  1. Heavy-ion induced current through an oxide layer

    Takahashi, Yoshihiro; Ohki, Takahiro; Nagasawa, Takaharu; Nakajima, Yasuhito; Kawanabe, Ryu; Ohnishi, Kazunori; Hirao, Toshio; Onoda, Shinobu; Mishima, Kenta; Kawano, Katsuyasu; Itoh, Hisayoshi

    2007-01-01

    In this paper, the heavy-ion induced current in MOS structure is investigated. We have measured the transient gate current in a MOS capacitor and a MOSFET induced by single heavy-ions, and found that a transient current can be observed when the semiconductor surface is under depletion condition. In the case of MOSFET, a transient gate current with both positive and negative peaks is observed if the ion hits the gate area, and that the total integrated charge is almost zero within 100-200 ns after irradiation. From these results, we conclude that the radiation-induced gate current is dominated by a displacement current. We also discuss the generation mechanism of the radiation-induced current through the oxide layer by device simulation

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

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

    1998-07-21

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

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

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

    1999-02-16

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

  4. Swift Heavy Ion Induced Modification of Aliphatic Polymers

    Hossain, Umme Habiba

    2015-01-01

    In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy I...

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

    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

  6. Damage induced in semiconductors by swift heavy ion irradiation

    Levalois, M.; Marie, P.

    1999-01-01

    The behaviour of semiconductors under swift heavy ion irradiation is different from that of metals or insulators: no spectacular effect induced by the inelastic energy loss has been reported in these materials. We present here a review of irradiation effects in the usual semiconductors (silicon, germanium and gallium arsenide). The damage is investigated by means of electrical measurements. The usual mechanisms of point defect creation can account for the experimental results. Besides, some results obtained on the wide gap semiconductor silicon carbide are reported. Concerning the irradiation effects induced by heavy ions in particle detectors, based on silicon substrate, we show that the deterioration of the detector performances can be explained from the knowledge of the substrate properties which are strongly perturbed after high doses of irradiation. Finally, some future ways of investigation are proposed. The silicon substrate is a good example to compare the irradiation effects with different particles such as electrons, neutrons and heavy ions. It is then necessary to use parameters which account for the local energy deposition, in order to describe the damage in the material

  7. L X-ray emission induced by heavy ions

    Pajek, M. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Banaś, D., E-mail: d.banas@ujk.edu.pl [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Braziewicz, J.; Majewska, U.; Semaniak, J. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Fijał-Kirejczyk, I. [The Institute of Atomic Energy, 05-400 Otwock-Świerk (Poland); Jaskóła, M.; Czarnacki, W.; Korman, A. [The National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Kretschmer, W. [Physikalisches Institut, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Mukoyama, T. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), H-4026 Debrecen (Hungary); Trautmann, D. [Institut für Physik, Universität Basel, Basel (Switzerland)

    2015-11-15

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster–Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L{sub 2}-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

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

    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

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

    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

  10. Radiation defects in lithium fluoride induced by heavy ions

    Trautmann, C.; Schwartz, K.; Steckenreiter, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Costantini, J.M. [CEA Centre d`Etudes de Bruyeres-le-Chatel, 91 (France). DPTA/SPMC; Toulemonde, M. [Centre Interdisciplinaire de Recherches avec les Ions Lourds (CIRIL), 14 - Caen (France)

    1998-07-01

    Single crystals of lithium fluoride were irradiated with various species of heavy ions in the energy regime between 1 and 30 MeV/u. The induced radiation damage was studied with techniques such as optical absorption spectroscopy, small-angle x-ray scattering, chemical etching and profilometry, complemented by annealing experiments. Clear evidence is given for a complex track structure and defect morphology. Single defects such as F-centers are produced in a large halo of several tens of nanometers around the ion trajectory. The defect creation in this zone is similar to that under conventional radiation. For heavy ions above a critical energy loss of 10 keV/nm, new effects occur within a very small core region of 2-4 nm in diameter. The damage in this zone is responsible for chemical etching and for a characteristic anisotropic x-ray scattering. It is assumed that in this core, complex defect aggregates (e.g., cluster of color centers, molecular anions and vacancies) are created. Their formation is only slightly influenced by the irradiation temperature and takes place even at 15 K where diffusion processes of primary defects are frozen. Furthermore, irradiation with heavy ions leads to pronounced swelling effects which can be related to an intermediate zone of around 10 nm around the ion path. (orig.) 40 refs.

  11. Swift heavy ion induced modification of aliphatic polymers

    Hossain, Umme Habiba

    2015-01-01

    In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy Ion Research (GSI) in Darmstadt. In order to study ion-beam induced degradation, all polymer foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (U, Au, Sm, Xe) and experimentation sites (beam lines X0 and M3) over a large fluence regime (1 x 10 10 - 5 x 10 12 ions/cm 2 ). Five independent techniques, namely infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy, residual gas analysis (RGA), thermal gravimetric analysis (TGA), and mass loss analysis (ML), were used to analyze the irradiated samples. FT-IR spectroscopy revealed that ion irradiation led to the decrease of characteristic band intensities showing the general degradation of the polymers, with scission of side groups and the main backbone. As a consequence of the structural modification, new bands appeared. UV-Vis transmission analysis showed an absorption edge shift from the ultraviolet region towards the visible region indicating double bond and conjugated double bond formation. On-line massspectrometric residual gas analysis showed the release of small gaseous fragment molecules. TGA analysis gave evidence of a changed thermal stability. With ML analysis, the considerable mass loss was quantified. The results of the five complementary analytical methods show how heavy ion irradiation changes the molecular structure of the polymers. Molecular degradation mechanisms are postulated. The amount of radiation damage is found to be sensitive to the used type of ionic species. While

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

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

    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

  14. Heavy-ion irradiation induced diamond formation in carbonaceous materials

    Daulton, T. L.

    1999-01-01

    The basic mechanisms of metastable phase formation produced under highly non-equilibrium thermodynamic conditions within high-energy particle tracks are investigated. In particular, the possible formation of diamond by heavy-ion irradiation of graphite at ambient temperature is examined. This work was motivated, in part, by earlier studies which discovered nanometer-grain polycrystalline diamond aggregates of submicron-size in uranium-rich carbonaceous mineral assemblages of Precambrian age. It was proposed that the radioactive decay of uranium formed diamond in the fission particle tracks produced in the carbonaceous minerals. To test the hypothesis that nanodiamonds can form by ion irradiation, fine-grain polycrystalline graphite sheets were irradiated with 400 MeV Kr ions. The ion irradiated graphite (and unirradiated graphite control) were then subjected to acid dissolution treatments to remove the graphite and isolate any diamonds that were produced. The acid residues were then characterized by analytical and high-resolution transmission electron microscopy. The acid residues of the ion-irradiated graphite were found to contain ppm concentrations of nanodiamonds, suggesting that ion irradiation of bulk graphite at ambient temperature can produce diamond

  15. Study of transient current induced by heavy-ion microbeams in Si and GaAs

    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)

  16. Clustered DNA damage induced by proton and heavy ion irradiation

    Davidkova, M.; Pachnerova Brabcova, K; Stepan, V.; Vysin, L.; Sihver, L.; Incerti, S.

    2014-01-01

    Ionizing radiation induces in DNA strand breaks, damaged bases and modified sugars, which accumulate with increasing density of ionizations in charged particle tracks. Compared to isolated DNA damage sites, the biological toxicity of damage clusters can be for living cells more severe. We investigated the clustered DNA damage induced by protons (30 MeV) and high LET radiation (C 290 MeV/u and Fe 500 MeV/u) in pBR322 plasmid DNA. To distinguish between direct and indirect pathways of radiation damage, the plasmid was irradiated in pure water or in aqueous solution of one of the three scavengers (coumarin-3-carboxylic acid, dimethylsulfoxide, and glycylglycine). The goal of the contribution is the analysis of determined types of DNA damage in dependence on radiation quality and related contribution of direct and indirect radiation effects. The yield of double strand breaks (DSB) induced in the DNA plasmid-scavenger system by heavy ion radiation was found to decrease with increasing scavenging capacity due to reaction with hydroxyl radical, linearly with high correlation coefficients. The yield of non-DSB clusters was found to occur twice as much as the DSB. Their decrease with increasing scavenging capacity had lower linear correlation coefficients. This indicates that the yield of non-DSB clusters depends on more factors, which are likely connected to the chemical properties of individual scavengers. (authors)

  17. Visualization of DNA clustered damage induced by heavy ion exposure

    Tomita, M.; Yatagai, F.

    2003-01-01

    Full text: DNA double-strand breaks (DSBs) are the most lethal damage induced by ionizing radiations. Accelerated heavy-ions have been shown to induce DNA clustered damage, which is two or more DNA lesions induced within a few helical turns. Higher biological effectiveness of heavy-ions could be provided predominantly by induction of complex DNA clustered damage, which leads to non-repairable DSBs. DNA-dependent protein kinase (DNA-PK) is composed of catalytic subunit (DNA-PKcs) and DNA-binding heterodimer (Ku70 and Ku86). DNA-PK acts as a sensor of DSB during non-homologous end-joining (NHEJ), since DNA-PK is activated to bind to the ends of double-stranded DNA. On the other hand, NBS1 and histone H2AX are essential for DSB repair by homologous recombination (HR) in higher vertebrate cells. Here we report that phosphorylated H2AX at Ser139 (named γ-H2AX) and NBS1 form large undissolvable foci after exposure to accelerated Fe ions, while DNA-PKcs does not recognize DNA clustered damage. NBS1 and γ-H2AX colocalized with forming discrete foci after exposure to X-rays. At 0.5 h after Fe ion irradiation, NBS1 and γ-H2AX also formed discrete foci. However, at 3-8 h after Fe ion irradiation, highly localized large foci turned up, while small discrete foci disappeared. Large NBS1 and γ-H2AX foci were remained even 16 h after irradiation. DNA-PKcs recognized Ku-binding DSB and formed foci shortly after exposure to X-rays. DNA-PKcs foci were observed 0.5 h after 5 Gy of Fe ion irradiation and were almost completely disappeared up to 8 h. These results suggest that NBS1 and γ-H2AX can be utilized as molecular marker of DNA clustered damage, while DNA-PK selectively recognizes repairable DSBs by NHEJ

  18. Swift heavy ion induced modification of aliphatic polymers

    Hossain, Umme Habiba

    2015-01-15

    In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy Ion Research (GSI) in Darmstadt. In order to study ion-beam induced degradation, all polymer foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (U, Au, Sm, Xe) and experimentation sites (beam lines X0 and M3) over a large fluence regime (1 x 10{sup 10} - 5 x 10{sup 12} ions/cm{sup 2}). Five independent techniques, namely infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy, residual gas analysis (RGA), thermal gravimetric analysis (TGA), and mass loss analysis (ML), were used to analyze the irradiated samples. FT-IR spectroscopy revealed that ion irradiation led to the decrease of characteristic band intensities showing the general degradation of the polymers, with scission of side groups and the main backbone. As a consequence of the structural modification, new bands appeared. UV-Vis transmission analysis showed an absorption edge shift from the ultraviolet region towards the visible region indicating double bond and conjugated double bond formation. On-line massspectrometric residual gas analysis showed the release of small gaseous fragment molecules. TGA analysis gave evidence of a changed thermal stability. With ML analysis, the considerable mass loss was quantified. The results of the five complementary analytical methods show how heavy ion irradiation changes the molecular structure of the polymers. Molecular degradation mechanisms are postulated. The amount of radiation damage is found to be sensitive to the used type of ionic

  19. What can we learn about heavy ion fusion by studying fission angular distributions

    Back, B.B.

    1984-01-01

    Determinations of complete fusion reactions leading to fissionable systems are associated with problems of separating fragments from quasi-fission reactions from those arising from fission of the completely fused system. Inferring complete fusion cross sections from the minute cross sections for the evaporation residue channel is hampered by the insufficient knowledge of the branching ratio for neutron emission and fission in the decay sequence of the completely fused system. From a quantitative analysis of the fragment angular distributions it is, however, possible under certain assumptions to deduce the relative contribution of complete fusion and quasi-fission. It is found that the complete fusion process is hindered for heavy projectiles. The excess radial energy over the interaction barrier needed to induce fusion with heavy projectiles is determined in several cases and systematic trends are presented

  20. Heavy ion induced genetic effects in mammalian cells. Final report

    Kiefer, J.; Brend'amour, M.; Casares, A.; Egenolf, R.; Gutermuth, F.; Ikpeme, S.E.; Koch, S.; Kost, M.; Loebrich, M.; Pross, H.D.; Russmann, C.; Schmidt, P.; Schneider, E.; Stoll, U.; Weber, K.J.

    2001-01-01

    DNA double-strand breaks (DSBs) are generally assumed to be the most relevant initial event producing radiation-induced cellular lethality, as well as mutations and transformations. The dependence of their formation on radiation quality has been recently reviewed. Contrary to earlier observations there seems to be now agreement that the RBE does not increase above unity with increasing LET in mammalian cells when conventional techniques are applied which are not able to resolve smaller fragments. If they are, however, included in the analysis maximum RBE values around 2 are obtained. The situation is different with yeast: An increased effectiveness for DSB induction has been reported with alpha particles, as well as for heavy ions. This may be due to differences in methods or to chromosomal structure, as discussed in more detail in this paper. DSB induction was measured for a LET range of 100 to 11500 keV/? m in yeast cells using pulsed field gel electrophoresis. Under the conditions applied the chromosomes of the yeast cells could be separated according to size allowing the direct quantification of the DSB yield by measuring the intensity of the largest chromosomes. The results demonstrate clearly that DSB induction in yeast depends on radiation quality. The derived cross-sections for DSB induction were also compared to those for cell inactivation determined in parallel experiments under identical irradiation conditions. (orig.)

  1. Accelerator aspects of heavy ion induced inertial fusion

    Boehme, D

    1983-01-01

    Besides the possibilities of the magnetic fusion those of inertial fusion have increasingly found interest. Bundled photon and corpuscular beams shall be symetrically focussed from the outside on a pellet with the fusion fuel being compressed far beyond the density of the ordinary solids. Laser, light ion and heavy ion beams can be used as driver beams. The GSI took over the project leadership for a five years' research programme with formulated questions on heavy ion fusion. The project is promoted by the BMFT. During the international symposium the opportunity of intensive discussions on research work in this field in different countries was made use of.

  2. Stress-tolerant mutants induced by heavy-ion beams

    Abe, Tomoko; Yoshida, Shigeo [Institute of Physical and Chemical Research, Wako, Saitama (Japan); Bae, Chang-Hyu [Sunchon National University, Sunchon (Korea); Ozaki, Takuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Wang, Jing Ming [Akita Prefectural Univ. (Japan)

    2000-07-01

    Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M{sub 1} seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M{sub 3} progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to {sup 14}N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M{sub 1} progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M{sub 1} seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

  3. Stress-tolerant mutants induced by heavy-ion beams

    Abe, Tomoko; Yoshida, Shigeo; Bae, Chang-Hyu; Ozaki, Takuo

    2000-01-01

    Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M 1 seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M 3 progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to 14 N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M 1 progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M 1 seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

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

    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.)

  5. Repair pathways for heavy ion-induced complex DNA double strand breaks

    Yajima, Hirohiko; Nakajima, Nakako; Hirakawa, Hirokazu; Murakami, Takeshi; Okayasu, Ryuichi; Fujimori, Akira

    2012-01-01

    DNA double strand break (DSB) induced by ionizing radiation (IR) is a deleterious damage leading to cell death and genome instability if not properly repaired. It is well known that DSB is repaired by two major pathways, non-homologous end-joining (NHEJ) and homologous recombination (HR). It is also known that NHEJ is dominant throughout the cell cycle after X- or gamma-ray irradiation in mammalian cells, Meanwhile, it is thought that heavy-ion radiation (e.g., carbon-ions, iron-ions) gives rise to clustered DNA damages consisting of not only strand breaks but also aberrant bases in the vicinity of DSBs (complex DSBs). Our previous work suggested that the efficiency of NHEJ is diminished for repair of complex DSBs induced by heavy-ion radiation. We thought that this difficulty in NHEJ process associated with heavy ion induced complex DNA damage might be extended to HR process in cells exposed to heavy ions. In order to find out if this notion is true or not, exposed human cells to X-rays and heavy-ions, and studied HR associated processes at the molecular level. Our result indicates that complex DSBs induced by heavy ions effectively evoke DNA end resection activity during the HR process. Together with our results, a relevant recent progress in the field of DNA DSB repair will be discussed. (author)

  6. Defect production and subsequent effects induced by electronic energy loss of swift heavy ion

    Hou Mingdong; Liu Jie; Sun Youmei; Yin Jingmin; Yao Huijun; Duan Jinglai; Mo Dan; Zhang Ling; Chen Yanfeng; Chinese Academy of Sciences, Beijing

    2008-01-01

    Swift heavy ion in matter is one of forfront fields of nuclear physics in the world. A series of new phenomena were discovered in recent years. The history and sta- tus on the development of this field were reviewed. Electronic energy loss effects induced by swift heavy ion irradiation, such as defect production and evolution, ion latent track formation, phase transformation and anisotropy plastic deformation were introduced emphatically. A trend of future investigation was explored. (authors)

  7. Sample and plume luminescence in fast heavy ion induced desorption

    Tuszynski, W.; Koch, K.; Hilf, E.R.

    1996-01-01

    The luminescence arising in 252 Cf-fission fragment induced desorption events has been measured using the time-correlated single photon counting technique. Photons emitted from the sample have been guided from a plasma desorption ion source to a photodetector by an optical fibre. Spectra and decay functions have been obtained using thin layers of Coronene or POPOP as samples. The results are strongly dependent on the acceleration field applied for ion extraction. Approximately 10 photons per fission fragment have been produced when applying no accelerating voltage. The results clearly show that these photons come from radiative electronic relaxations of molecules in the solid sample. Considerably more photons per fission fragment have been produced when applying a positive acceleration voltage. The intensity increases almost linearly for acceleration fields below 10 kV/cm and saturates at a nearly 10-fold higher value when compared to no acceleration. The intensity is also affected by the homogeneity of the accelerating field. These additional photons are attributed to radiative electronic relaxations of desorbed neutral molecules in the plume excited by inelastic collisions with accelerated positive ions. No additional photons have been observed when extracting negative ions. The negative ions produced do obviously not hit and/or excite desorbed neutral molecules, presumably due to their specific desorption characteristics. The experimental data have been analyzed by comparing with the cw and time-resolved sample luminescence obtained by optical excitation. The findings demonstrate that valuable information on ion-solid interactions, on specific desorption quantities and on processes in the plume can be obtained by measuring and analyzing the luminescence induced by the impact of high energy primary ions. (orig.)

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

    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.)

  9. An effective method for detection and analysis of DNA damage induced by heavy-ion beams

    Kazama, Y.; Saito, H.; Fujiwara, M.; Matsuyama, T.; Hayashi, Y.; Ryuto, H.; Fukunishi, N.; Abe, T.

    2007-01-01

    We have developed an efficient system to detect and analyze DNA mutations induced by heavy-ion beams in Arabidopsis thaliana. In this system, a stable transgenic Arabidopsis line that constitutively expresses a yellow fluorescent protein (YFP) by a single-copy gene at a genomic locus was constructed and irradiated with heavy-ion beams. The YFP gene is a target of mutagenesis, and its loss of function or expression can easily be detected by the disappearance of YFP signals in planta under microscopy. With this system, a sup(12)Csup(6+)- induced mutant with single deletion and multiple base changes was isolated

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

    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

  11. Multifragmentation induced by light relativistic projectiles and heavy ions: similarities and differences

    Karnaukhov, V.A.; Avdeev, S.P.; Kuznetsov, V.D.

    1998-01-01

    The experimental data on fragment multiplicities, their energy and charge distributions, the emission times are considered for the nuclear multifragmentation process induced by relativistic light projectiles (protons, helium) and heavy ions. With light projectiles, the multifragmentation is a pure 'thermal' process, well described by the statistical models. Heavy-ion-induced multifragmentation is influenced by dynamic effects related first of all to the compression of the system in the collision. But statistical models can also be applied to rendering the partition of the system if the excitation energy is less than 10 MeV/nucleon and compression is modest. For the central collision of heavy ions the statistical approach fails to describe the data

  12. Surface Modifications of Polymers Induced by Heavy Ions Grafting

    Mazzei, R O; Lombardo, J; Camporotondi, D; Tadey, D; Bermudez, G G [National Atomic Energy Commission, Ezeiza Atomic Centre, Ezeiza (Argentina)

    2012-09-15

    Polymer surfaces are modified by the application of swift heavy ions etching and grafting procedures. The residual active sites produced by heavy ion beams, remaining after the etching process, were used to start the grafting process. In order to produce tracks on foils of poly(vinylidene fluoride) (PVDF) they were irradiated with {sup 208}Pb of 25.62 MeV/n or with 115 MeV Cl ions. Moreover, foils of polypropylene (PP) were irradiated with {sup 208}Pb of 25.62 MeV/n. Then, they were etched and grafted with N-isopropylacrylamide (NIPAAm) monomers or with acrylic acid (AAc) monomers, respectively. The replica method allowed the observation of the shape of the grafted tracks using transmission electron microscopy (TEM). In addition NIPAAm grafted foils were analyzed using Fourier transform infrared spectroscopy (FTIR). The sulfonation procedure (methodology previously described for perfluorated polymers) was applied on grafted PVDF. A new method is described to produce a thin layer of poly-acrylic-acid (membranes) that grows on the surface of PVDF foils implanted by an Ar{sup +} beam with energies between 30-150 keV. Different combinations of monomers in water solutions were used such as: acrylic acid (AAc); acrylic acid-glycidyl methacrylate (AAc-GMA); acrylic acid-styrene (AAc-S); acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid-N-isopropyl acrylamide - glycidyl methacrylate (AAc-NIPAAm-GMA). The experimental results show that for particular values of: ion fluence and energy, AAc concentration, sulphuric acid and PVDF polymorphous (alpha or beta) a huge percentage of grafting was obtained. At certain point of the grafting process the development of the PolyAAc-Xmonomer produce a detachment from the irradiated substrate and continue its grafting outside it. This method produces a membrane that is an increased replica of the original implanted surface. Finally, PVDF films implanted by an Ar{sup +} beam with energies about 100 keV and a fluence of 10

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

    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

  14. Heavy ion irradiation induces autophagy in irradiated C2C12 myoblasts and their bystander cells

    Hino, Mizuki; Tajika, Yuki; Hamada, Nobuyuki

    2010-01-01

    Autophagy is one of the major processes involved in the degradation of intracellular materials. Here, we examined the potential impact of heavy ion irradiation on the induction of autophagy in irradiated C2C12 mouse myoblasts and their non-targeted bystander cells. In irradiated cells, ultrastructural analysis revealed the accumulation of autophagic structures at various stages of autophagy (id est (i.e.) phagophores, autophagosomes and autolysosomes) within 20 min after irradiation. Multivesicular bodies (MVBs) and autolysosomes containing MVBs (amphisomes) were also observed. Heavy ion irradiation increased the staining of microtubule-associated protein 1 light chain 3 and LysoTracker Red (LTR). Such enhanced staining was suppressed by an autophagy inhibitor 3-methyladenine. In addition to irradiated cells, bystander cells were also positive with LTR staining. Altogether, these results suggest that heavy ion irradiation induces autophagy not only in irradiated myoblasts but also in their bystander cells. (author)

  15. DNA damage and chromosome aberration induced by heavy-ion beams

    Takakura, Kahoru; Funada, Aya; Aoki, Mizuho; Furusawa, Yoshiya

    2003-01-01

    The aim of this study is to clarify the relation between cell death and chromosomal aberration in cultured human cells (human salivary gland (HSG) tumor cells and GM05389 human normal fibroblasts) irradiated with heavy ion beams on the basis of linear energy transfer (LET) values. The LET dependences of cell death were observed for the both cells by the method of colony assay. The LET dependences of the chromosomal aberrations, breaks and gaps, isochromatid breaks and exchanges were also observed for the both cells using the premature chromosome condensation (PCC) method. From these results it is suggested that exchange formation is essential for the cell death caused by heavy ion beam irradiation. It is suspected that the densely ionizing track structure of hight LET heavy ions inhibits the effective repair in the chromatid breaks and isochromatid breaks and finally induce much exchange in the cells, which should be essential cause of cell death. (author)

  16. Description of current pulses induced by heavy ions in silicon detectors (II)

    Hamrita, H. [Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay Cedex (France); CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette Cedex (France); Parlog, M. [LPC, CNRS/IN2P3, ENSICAEN, Universite de Caen, F-14050 Caen Cedex (France); National Institute for Physics and Nuclear Engineering, RO-76900 Bucharest-Magurele (Romania); Borderie, B., E-mail: borderie@ipno.in2p3.fr [Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay Cedex (France); Lavergne, L. [Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay Cedex (France); Le Neindre, N. [Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay Cedex (France); LPC, CNRS/IN2P3, ENSICAEN, Universite de Caen, F-14050 Caen Cedex (France); Rivet, M.F.; Barbey, S. [Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay Cedex (France); Bougault, R. [LPC, CNRS/IN2P3, ENSICAEN, Universite de Caen, F-14050 Caen Cedex (France); Chabot, M. [Inst. de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay Cedex (France); Chbihi, A. [GANIL (DSM-CEA/CNRS/IN2P3), F-14076 Caen Cedex (France); Cussol, D. [LPC, CNRS/IN2P3, ENSICAEN, Univ. de Caen, F-14050 Caen Cedex (France); Oliveira Santos, F. de [GANIL (DSM-CEA/CNRS/IN2P3), F-14076 Caen Cedex (France); Edelbruck, P. [Inst. de Physique Nucleaire, CNRS/IN2P3, Univ. Paris-Sud 11, F-91406 Orsay Cedex (France); Frankland, J.D. [GANIL (DSM-CEA/CNRS/IN2P3), F-14076 Caen Cedex (France); Galichet, E. [Inst. de Physique Nucleaire, CNRS/IN2P3, Univ. Paris-Sud 11, F-91406 Orsay Cedex (France); Conservatoire National des Arts et Metier, F-75141 Paris Cedex 03 (France); Guinet, D.; Lautesse, Ph. [Inst. de Physique Nucleaire, CNRS/IN2P3, Univ.e Claude Bernard Lyon I, F-69622 Villeurbanne Cedex (France); Lopez, O. [LPC, CNRS/IN2P3, ENSICAEN, Univ. de Caen, F-14050 Caen Cedex (France)

    2011-06-21

    Current pulses induced in a silicon detector by 10 different heavy ion species at known energies around 10 A MeV have been sampled in time at high frequency. Their individual average shapes are quite well reproduced by a fit procedure based on our recent charge carrier collection treatment which considers the progressive extraction of the electrons and holes from the high carrier density zone along the ionizing particle track. This region is assumed to present a supplementary dielectric polarization and consequently a disturbed electric field. The influence of the nature of the heavy ion on the values of the three fit parameters is analyzed.

  17. Epigenetic Analysis of Heavy-ion Radiation Induced Bystander Effects in Mice

    Zhang, Meng; Sun, Yeqing; Cui, Changna; Xue, Bei

    Abstract: Radiation-induced bystander effect was defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic and proteomics plays significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were exposed head-only to 40, 200, 2000mGy dose of (12) C heavy-ion radiation, while the rest of the animal body was shielded. Directly radiation organ ear and the distant organ liver were detected on 1h, 6h, 12h and 24h after radiation, respectively. Methylation-sensitive amplification polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that heavy-ion irradiated mouse head could induce genomic DNA methylation changes significantly in both the directly radiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate was highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation. The global DNA methylation changes tended to occur in the CG sites. The results illustrated that genomic methylation changes of heavy ion radiation-induced bystander effect in liver could be obvious 1 h after radiation and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in both directly radiation organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of

  18. Surface amorphization in Al2O3 induced by swift heavy ion irradiation

    Okubo, N.; Ishikawa, N.; Sataka, M.; Jitsukawa, S.

    2013-01-01

    Microstructure in single crystalline Al 2 O 3 developed during irradiation by swift heavy ions has been investigated. The specimens were irradiated by Xe ions with energies from 70 to 160 MeV at ambient temperature. The fluences were in the range from 1.0 × 10 13 to 1.0 × 10 15 ions/cm 2 . After irradiations, X-ray diffractometry (XRD) measurements and cross sectional transmission electron microscope (TEM) observations were conducted. The XRD results indicate that in the initial stage of amorphization in single crystalline Al 2 O 3 , high-density S e causes the formation of new planes and disordering. The new distorted lattice planes formed in the early stage of irradiation around the fluence of 5.0 × 10 13 ions/cm 2 for single crystalline Al 2 O 3 irradiated with 160 MeV-Xe ions. Energy dependence on structural modification was also examined in single crystalline Al 2 O 3 irradiated by swift heavy ions. The XRD results indicate that the swift heavy ion irradiation causes the lattice expansion and the structural modification leading to amorphization progresses above the energy around 100 MeV in this XRD study. The TEM observations demonstrated that amorphization was induced in surface region in single crystalline Al 2 O 3 irradiated by swift heavy ions above the fluence expected from the results of XRD. Obvious boundary was observed in the cross sectional TEM images. The crystal structure of surface region above the boundary was identified to be amorphous and deeper region to be single crystal. The threshold fluence of amorphization was found to be around 1.0 × 10 14 ions/cm 2 in the case over 80 MeV swift heavy ion irradiation and the fluence did not depend on the crystal structures

  19. Surface amorphization in Al2O3 induced by swift heavy ion irradiation

    Okubo, N.; Ishikawa, N.; Sataka, M.; Jitsukawa, S.

    2013-11-01

    Microstructure in single crystalline Al2O3 developed during irradiation by swift heavy ions has been investigated. The specimens were irradiated by Xe ions with energies from 70 to 160 MeV at ambient temperature. The fluences were in the range from 1.0 × 1013 to 1.0 × 1015 ions/cm2. After irradiations, X-ray diffractometry (XRD) measurements and cross sectional transmission electron microscope (TEM) observations were conducted. The XRD results indicate that in the initial stage of amorphization in single crystalline Al2O3, high-density Se causes the formation of new planes and disordering. The new distorted lattice planes formed in the early stage of irradiation around the fluence of 5.0 × 1013 ions/cm2 for single crystalline Al2O3 irradiated with 160 MeV-Xe ions. Energy dependence on structural modification was also examined in single crystalline Al2O3 irradiated by swift heavy ions. The XRD results indicate that the swift heavy ion irradiation causes the lattice expansion and the structural modification leading to amorphization progresses above the energy around 100 MeV in this XRD study. The TEM observations demonstrated that amorphization was induced in surface region in single crystalline Al2O3 irradiated by swift heavy ions above the fluence expected from the results of XRD. Obvious boundary was observed in the cross sectional TEM images. The crystal structure of surface region above the boundary was identified to be amorphous and deeper region to be single crystal. The threshold fluence of amorphization was found to be around 1.0 × 1014 ions/cm2 in the case over 80 MeV swift heavy ion irradiation and the fluence did not depend on the crystal structures.

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

    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

  1. Jet-induced medium excitation in heavy-ion collisions

    Chen, Wei [Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Pang, Long-Gang [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, 60438 Frankfurt am Main (Germany); Stoecker, Horst [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, 60438 Frankfurt am Main (Germany); Gesellschaft für Schwehrionenforschung, Planckstr. 1, Darmstadt (Germany); Luo, Tan; Wang, Enke [Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Wang, Xin-Nian [Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Nuclear Science Division Mailstop 70R0319, Lawrence Berkeley National Laboratory, Berkeley, CA 94740 (United States)

    2016-12-15

    We use a Linear Boltzmann Transport (LBT) model coupled to the (3+1)D ideal hydrodynamic evolution in real time with fluctuating initial conditions to simulate both the transport of jet shower partons and jet-induced medium excitation. In this coupled approach, propagation of energetic shower partons are treated in the LBT model with the 3+1D hydrodynamic model providing the evolving bulk medium. Soft partons from both elastic and inelastic processes in the LBT are fed back into the medium as a source term in the 3+1D hydrodynamics leading to induced medium excitation. We study the effect of jet-induced medium excitation via γ-hadron correlation within this coupled LBT-hydro (CoLBT-hydro) approach.

  2. Heavy Ion Microbeam- and Broadbeam-Induced Transients in SiGe HBTs

    Pellish, Jonathan A.; Reed, Robert A.; McMorrow, Dale; Vizkelethy, Gyorgy; Ferlet-Cavrois, Veronique; Baggio, Jacques; Duhamel, Olivier; Moen, Kurt A.; Phillips, Stanley D.; Diestelhorst, Ryan M.; hide

    2009-01-01

    SiGe HBT heavy ion-induced current transients are measured using Sandia National Laboratories microbeam and high- and low-energy broadbeam sources at the Grand Accelerateur National d'Ions Lourds and the University of Jyvaskyla. The data were captured using a custom broadband IC package and real-time digital phosphor oscilloscopes with at least 16 GHz of analog bandwidth. These data provide detailed insight into the effects of ion strike location, range, and LET.

  3. Heavy ion induced DNA transfer in biological cells

    Vilaithong, T.; Yu, L.D.; Apavatjrut, P.; Phanchaisri, B.; Sangyuenyongpipat, S.; Anuntalabhochai, S.; Brown, I.G.

    2004-01-01

    Low-energy ion beam bombardment of biological materials for genetic modification purposes has experienced rapid growth in the last decade, particularly for the direct DNA transfer into living organisms including both plants and bacteria. Attempts have been made to understand the mechanisms involved in ion-bombardment-induced direct gene transfer into biological cells. Here we summarize the present status of the application of low-energy ions for genetic modification of living sample materials

  4. Monte Carlo simulation of heavy ion induced kinetic electron emission from an Al surface

    Ohya, K

    2002-01-01

    A Monte Carlo simulation is performed in order to study heavy ion induced kinetic electron emission from an Al surface. In the simulation, excitation of conduction band electrons by the projectile ion and recoiling target atoms is treated on the basis of the partial wave expansion method, and the cascade multiplication process of the excited electrons is simulated as well as collision cascade of the recoiling target atoms. Experimental electron yields near conventional threshold energies of heavy ions are simulated by an assumption of a lowering in the apparent surface barrier for the electrons. The present calculation derives components for electron excitations by the projectile ion, the recoiling target atoms and the electron cascades, from the calculated total electron yield. The component from the recoiling target atoms increases with increasing projectile mass, whereas the component from the electron cascade decreases. Although the components from the projectile ion and the electron cascade increase with...

  5. Implications of heavy-ion induced satellite x-ray emission. I. Introduction

    Raman, S.; Vane, C.R.

    1983-01-01

    Regardless of how they are induced, x-ray spectra are sensitive to the chemical environment of the emitting atom and can yield information on the atomic and electronic structure of host materials. Those spectra resulting from light ion and heavy ion excitations are the main topics covered in this series of papers. Highly energetic heavy ions are capable of producing multiple innershell ionization. The resulting spectrum of x-rays from a particular target atom is composed of a complex series of satellite lines. Environmental effects give rise to the redistribution of intensity from one satellite group to another. These changes can be correlated with one satellite group to another. These changes can be correlated with bulk chemical properties (valence electron densities, effective charges, covalencies, etc.). The possibility of obtaining new chemical information (for example, in implanted materials and in metal alloys) exists but requires greater experimental and theoretical understanding of both parametric variations and the fine structure of satellite lines

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

    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

  7. Trace analysis in cadmium telluride by heavy ion induced X-ray emission and by SIMS

    Scharager, C.; Stuck, R.; Siffert, P.; Cailleret, J.; Heitz, Ch.; Lagarde, G.; Tenorio, D.

    1979-01-01

    The possibilities of using both selective heavy ion induced X-ray emission and secondary ion mass spectroscopy (SIMS), for the identification of impurities present at low concentrations in cadmium telluride are examined. The relative concentrations of the impurities along CdTe crystals have been determined by exciting the X-ray emission of the elements in several slices with Ar and Kr ions and by comparing the relative characteristic X-ray emission yields. As a consequence of the quasimolecular inner shell ionization mechanism in heavy ion-atom collisions, Ar and Kr ions allow a strong excitation of the main impurities seen by SIMS namely Si, Cl and Ge, As, with only a minor contribution of Cd and Te. From the changes of the concentrations of the various impurities along the crystal, informations about segregation coefficients and compensation can be obtained

  8. Tracks induced by swift heavy ions in semiconductors

    Szenes, G.; Horvath, Z.E.; Pecz, B.; Toth, L.; Paszti, F.

    2002-01-01

    InSb, GaSb, InP, InAs, and GaAs single crystals were irradiated with Pb ions in the range of 385-2170 MeV. The samples were studied by transmission and high-resolution electron microscopy and Rutherford backscattering in channeling geometry. The energetic ions induced isolated tracks in all crystals but GaAs. The thermal spike analysis revealed that the variation of the damage cross section with the ion energy is considerably weaker than in insulators. The widths of the thermal spike a(0) was estimated. The analysis was extended to recent C 60 experiments on Ge and Si. A quantitative relation was found between a(0) and the gap energy E g : a(0) is reduced with increasing E g , and its lowest value is close to that found in insulators

  9. Investigations of Atomic Transport Induced by Heavy Ion Irradiation

    Banwell, Thomas Clyde

    The mechanisms of atomic transport induced by ion irradiation generally fall into the categories of anisotropic or isotropic processes. Typical examples of these are recoil implantation and cascade mixing, respectively. We have measured the interaction of these processes in the mixing of Ti/SiO(,2)/Si, Cr/SiO(,2)/Si and Ni/SiO(,2)/Si multi-layers irradiated with Xe at fluences of 0.01 - 10 x 10('15)cm('-2). The fluence dependence of net metal transport into the underlying layers was measured with different thicknesses of SiO(,2) and different sample temperatures during irradiation (-196 to 500C). There is a linear dependence at low fluences. At high fluences, a square-root behavior predominates. For thin SiO(,2) layers (primary recoils is quite pronounced since the gross mixing is small. A significant correlation exists between the mixing and the energy deposited through elastic collisions F(,D ). Several models are examined in an attempt to describe the transport process in Ni/SiO(,2). It is likely that injection of Ni by secondary recoil implantation is primarily responsible for getting Ni into the SiO(,2). Secondary recoil injection is thought to scale with F(,D). Trends in the mixing rates indicate that the dominant mechanism for Ti and Cr could be the same as for Ni. The processes of atomic transport and phase formation clearly fail to be separable at higher temperatures. A positive correlation with chemical reactivity emerges at higher irradiation temperatures. The temperature at which rapid mixing occurs is not much below that for spontaneous thermal reaction. Less Ni is retained in the SiO(,2) at high irradiation temperatures. Ni incorporated in the SiO(,2) by low temperature irradiation is not expelled during a consecutive high temperature irradiation. The Ni remains trapped within larger clusters during a sequential 500C irradiation. (Abstract shortened with permission of author.).

  10. Cell killing and chromosomal aberration induced by heavy-ion beams in cultured human tumor cells

    Takakura, K.; Funada, A.; Mohri, M.; Lee, R.; Aoki, M.; Furusawa, Y.; Gotoh, E.

    2003-01-01

    Full text: To clarify the relation between cell death and chromosomal aberration in cultured human tumor cells irradaited with heavy-ion beams. The analyses were carried out on the basis of the linear energy transfer (LET) values of heavy ion beams as radiation source. Exponentially growing human tumor cells, Human Salivary Gland Tumor cells (HSG cells), were irradiated with various high energy heavy ions, such as 13 keV/micrometer carbon (C) ions as low LET charged particle radiation source, 120 keV/ micrometer carbon (C) ions and 440 keV/micrometer iron (Fe) ions as high LET charged particle radiation sources.The cell death was analysed by the colony formation method, and the chromosomal aberration and its repairing kinetics was analysed by prematurely chromosome condensation method (PCC method) using calyculin A. Chromatid-type breaks, isochromatid breaks and exchanges were scored for the samples from the cells keeping with various incubation time after irradiation. The LET dependence of the cell death was similar to that of the chromosome exchange formation after 12 hours incubation. A maximum peak was around 120 keV/micrometer. However it was not similar to the LET dependence of isochromatid breaks or chromatid breaks after 12 hours incubation. These results suggest that the exchanges formed in chromosome after irradiation should be one of essential causes to lead the cell death. The different quality of induced chromosome damage between high-LET and low-LET radiation was also shown. About 89 % and 88 % chromatid breaks induced by X rays and 13 keV/micrometer C ions were rejoined within 12 hours of post-irradiation, though only 71% and 58 % of chromatid breaks induced by 120 keV/micrometer C ions and 440 keV/micrometer Fe ions were rejoined within 12 hours of post-irradiation

  11. Alkyne End Group Production in Polymeric Materials Induced by Swift Heavy Ion Irradiations

    2001-01-01

    Swift heavy ions in matter lose energy mainly through electronic processes.Since the energy deposition is centered in a very small region with a very high energy density,new effects such as production of alkyne end group can be induced.In this work,PET,PS,PC and PI films are irradiated with Ar,Kr,Xe and U ions and the relationship of the alkyne end group production with electronic energy loss is studied by Fourier transformed infrared infrared(FTLR)spectra measurements.

  12. Laser radiation effect on radiation-induced defects in heavy ion tracks in dielectrics

    Egorov, A.N.; Zhiryakov, B.M.; Kushin, V.V.; Lyapidevskij, V.K.; Khokhlov, N.B.

    1988-01-01

    Possibility of laser radiation resonance effect on radiation-induced defects in heavy ion tracks in dielectric materials is investigated. Absorption spectra in infrared, visible and ultraviolet ranges for cellulose nitrate samples irradiated by 6 MeV/nucleon 58 Ni ions and reactor gamma radiation are measured. Absorption spectra for irradiated and reference samples are presented. Two absorption bands λ 1 =0.33 μm (E 1 =3.9 eV) and λ 2 =0.72 μm (E 2 =1.7 eV) are detected. Etching rate decrease in a track under laser radiation effect is noticed. 3 refs.; 1 fig

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

    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. Intense heavy ion beam-induced effects in carbon-based stripper foils

    Kupka, Katharina

    2016-08-15

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  15. Intense heavy ion beam-induced effects in carbon-based stripper foils

    Kupka, Katharina

    2016-08-01

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  16. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  17. Charged particle-induced nuclear fission reactions

    The nuclear fission phenomenon continues to be an enigma, even after nearly 75 years of its discovery. Considerable progress has been made towards understanding the fission process. Both light projectiles and heavy ions have been employed to investigate nuclear fission. An extensive database of the properties of ...

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

    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)

  19. Development of an animal model for heavy ion radiation-induced nausea and vomiting

    Yamatodani, Atsushi; Yamamoto, Kouichi; Nohara, Kyoko

    2003-01-01

    Emesis is one of the most characteristic side effects of radiation therapy. Clinical and pharmacological findings indicate that the peripheral serotonergic pathway is predominantly involved in the development of radiation-induced emesis, but the precise etiology is still unknown. We previously demonstrated that the activation of the histaminergic neuron system in the brain is essential for the development of motion-induced emesis (motion sickness). In this study, we studied the effects of heavy-ion irradiation on the hypothalamic histamine release measured in vivo with a microdialysis method in mice. Total body irradiation at dose of 8 Gy (carbon ion: 290 MeV/u, 6 cm spread-out Bragg peak (SOBP)) did not cause any significant changes in the histamine release in mice. These findings indicate that the central histaminergic activation is not involved in the development of radiation-induced emesis in mice. (author)

  20. Single ion induced surface nanostructures: a comparison between slow highly charged and swift heavy ions.

    Aumayr, Friedrich; Facsko, Stefan; El-Said, Ayman S; Trautmann, Christina; Schleberger, Marika

    2011-10-05

    This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms. © 2011 IOP Publishing Ltd

  1. A simple model of heavy ion-induced linear momentum transfer

    Skulski, W.; Blocki, J.

    1990-01-01

    This paper reports on linear momentum transfer (LMT) from the projectile to the heavy reaction residue which is among the observables, fair account of which is expected from any model of nuclear collisions. Almost thirty years ago it was shown that heavy ions bombarding highly fissionable targets like uranium give rise to double-peaked LMT distributions. (For such targets almost every projectile-target interaction leads to fission, enabling one to use the binary fission fragment correlation technique to obtain LMT distribution for the whole reaction cross section). Since the pioneering work comprehensive systematics of the LMT spectra were published for many HI projectiles, A p = 12-86, almost invariably double-peaked in the bombarding energy range E/A p = 10-40 MeV/nucleon. It was shown in the 16 O+ 238 U experiment at E/A p =20 MeV/nucleon, that the lower LMT peak is in the prompt coincidence with the projectile-like fragment detected at 15 degrees (LAB), an evidence of the peripheral collisions. LMT - neutron multiplicity coincidence study has shown, that the lower LMT peak has also low associated neutron multiplicity n > (and hence low excitation energy E * ), whereas the higher LMT peak has high coincident n > - an evidence of high E * . Low and high E * are plausible signatures of the peripheral and central collisions, respectively. The original interpretation of the double-peaked LMT distributions associates the low LMT peak with the incomplete fusion reaction, in which part of the projectile is emitted forward with the beam velocity. The double-peaked structure would thus reflect the probability of the different projectile divisions into the emitted and captured parts

  2. Groomed jets in heavy-ion collisions: sensitivity to medium-induced bremsstrahlung

    Mehtar-Tani, Yacine [Institute of Nuclear Theory, University of Washington,Seattle, WA 98195-1550 (United States); Tywoniuk, Konrad [Theoretical Physics Department, CERN,1211 Geneva 23 (Switzerland)

    2017-04-21

    We argue that contemporary jet substructure techniques might facilitate a more direct measurement of hard medium-induced gluon bremsstrahlung in heavy-ion collisions, and focus specifically on the “soft drop declustering” procedure that singles out the two leading jet substructures. Assuming coherent jet energy loss, we find an enhancement of the distribution of the energy fractions shared by the two substructures at small subjet energy caused by hard medium-induced gluon radiation. Departures from this approximation are discussed, in particular, the effects of colour decoherence and the contamination of the grooming procedure by soft background. Finally, we propose a complementary observable, that is the ratio of the two-pronged probability in Pb-Pb to proton-proton collisions and discuss its sensitivity to various energy loss mechanisms.

  3. EM-induced processes in heavy ion collisions with the ATLAS detector at the LHC

    Steinberg, Peter; The ATLAS collaboration

    2018-01-01

    Electromagnetic processes provide new tools for studying the partonic structure of nuclei, and possibly for directly probing the quark gluon plasma. Ultra-peripheral heavy ion collisions occur when the nuclei have large impact parameter and interact through photon-induced reactions. These include processes in which an energetic photon emitted by one nucleus resolves the partonic structure of the other and stimulates jet production. Much like deep inelastic scattering, such processes provide a clean probe of the nuclear parton distributions. Jet photo-production represents the most direct opportunity to study nuclear parton distributions until a future electron-ion collider is constructed. This talk presents measurements of ultra-peripheral jet photo-production in Pb+Pb collisions with the ATLAS detector at the LHC. It also presents another application of EM-induced processes, where dimuons produced by gamma-gamma processes are observed to show a centrality-dependent broadening in their opening angle, which ca...

  4. Reorientation of the crystalline planes in confined single crystal nickel nanorods induced by heavy ion irradiation

    Misra, Abha; Tyagi, Pawan K.; Rai, Padmnabh; Misra, D. S.; Ghatak, Jay; Satyam, P. V.; Avasthi, D. K.

    2006-01-01

    In a recent letter Tyagi et al. [Appl. Phys. Lett. 86, 253110 (2005)] have reported the special orientation of nickel planes inside multiwalled carbon nanotubes (MWCNTs) with respect to the tube axis. Heavy ion irradiation has been performed with 1.5 MeV Au 2+ and 100 MeV Au 7+ ions on these nickel filled MWCNTs at fluences ranging from 10 12 to 10 15 ions/cm 2 at room temperature. Ion-induced modifications have been studied using high-resolution transmission electron microscopy. The diffraction pattern and the lattice imaging showed the presence of ion-induced planar defects on the tube walls and completely amorphized encapsulated nickel nanorods. The results are discussed in terms of thermal spike model

  5. Groomed jets in heavy-ion collisions: sensitivity to medium-induced bremsstrahlung

    Mehtar-Tani, Yacine

    2017-04-21

    We argue that contemporary jet substructure techniques might facilitate a more direct measurement of hard medium-induced gluon bremsstrahlung in heavy-ion collisions, and focus specifically on the "soft drop declustering" procedure that singles out the two leading jet substructures. Assuming coherent jet energy loss, we find an enhancement of the distribution of the energy fractions shared by the two substructures at small subjet energy caused by hard medium-induced gluon radiation. Departures from this approximation are discussed, in particular, the effects of colour decoherence and the contamination of the grooming procedure by soft background. Finally, we propose a complementary observable, that is the ratio of the two-pronged probability in Pb-Pb to proton-proton collisions and discuss its sensitivity to various energy loss mechanisms.

  6. Groomed jets in heavy-ion collisions: sensitivity to medium-induced bremsstrahlung

    Mehtar-Tani, Yacine; Tywoniuk, Konrad

    2017-04-01

    We argue that contemporary jet substructure techniques might facilitate a more direct measurement of hard medium-induced gluon bremsstrahlung in heavy-ion collisions, and focus specifically on the "soft drop declustering" procedure that singles out the two leading jet substructures. Assuming coherent jet energy loss, we find an enhancement of the distribution of the energy fractions shared by the two substructures at small subjet energy caused by hard medium-induced gluon radiation. Departures from this approximation are discussed, in particular, the effects of colour decoherence and the contamination of the grooming procedure by soft background. Finally, we propose a complementary observable, that is the ratio of the two-pronged probability in Pb-Pb to proton-proton collisions and discuss its sensitivity to various energy loss mechanisms.

  7. Groomed jets in heavy-ion collisions: sensitivity to medium-induced bremsstrahlung

    Mehtar-Tani, Yacine; Tywoniuk, Konrad

    2017-01-01

    We argue that contemporary jet substructure techniques might facilitate a more direct measurement of hard medium-induced gluon bremsstrahlung in heavy-ion collisions, and focus specifically on the “soft drop declustering” procedure that singles out the two leading jet substructures. Assuming coherent jet energy loss, we find an enhancement of the distribution of the energy fractions shared by the two substructures at small subjet energy caused by hard medium-induced gluon radiation. Departures from this approximation are discussed, in particular, the effects of colour decoherence and the contamination of the grooming procedure by soft background. Finally, we propose a complementary observable, that is the ratio of the two-pronged probability in Pb-Pb to proton-proton collisions and discuss its sensitivity to various energy loss mechanisms.

  8. Techniques for the research on mass deposition effects in the bio-materials induced by heavy ion implantation

    Yuan Shibin; Wei Zengquan; Li Qiang

    2002-01-01

    Researchers have used heavy ion beams to implant small biomolecules, followed by advanced instrumental analysis to make preliminary studies on mass deposition induced by ion implantation. But research reports on the biological effects, i.e. mass deposition effects induced by mass deposition in living tissues, cells and macro-biomolecules have not been delivered hitherto. In the near future radioactive heavy ion beams will be possible to implant living cells and biomolecules, and auto-radiography, radioactive measurements and molecular biological techniques will be employed to further studies on the effects

  9. Study of the mechanisms of heavy-ion induced desorption on accelerator-relevant materials

    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.)

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

    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)

  11. Damage cross sections for fast heavy ion induced desorption of biomolecules

    Salehpour, M; Hakansson, P; Sundqvist, B [Uppsala Univ. (Sweden). Tandem Accelerator Lab.

    1984-03-01

    The Uppsala EN-tandem accelerator combined with a time-of-flight mass spectrometer has been used to measure the damage cross sections for Fast Heavy Ion Induced Desorption (FHIID) of the amino acid valine (MW=117) and the protein bovine insulin (MW=5733). Time-of-flight spectra have been obtained after exposing the sample to a known radiation dose of 90 MeV /sup 127/I/sup 14 +/ ions and the yield of the quasi-molecular ions has been measured as a function of the radiation dose. The results are: 6.8(+-1.8)x10/sup -13/ cm/sup 2/ and 50(+-17)x10/sup -13/ cm/sup 2/ for positive ions of valine and insulin respectively. The cross section for valine is roughly one order of magnitude larger than previously published low energy (keV) damage cross sections for the amino acid leucine.

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

    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

    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. Swift heavy ion induced surface and microstructural evolution in metallic glass thin films

    Thomas, Hysen; Thomas, Senoy; Ramanujan, Raju V.; Avasthi, D.K.; Al- Omari, I.A.; Al-Harthi, Salim; Anantharaman, M.R.

    2012-01-01

    Swift heavy ion induced changes in microstructure and surface morphology of vapor deposited Fe–Ni based metallic glass thin films have been investigated by using atomic force microscopy, X-ray diffraction and transmission electron microscopy. Ion beam irradiation was carried out at room temperature with 103 MeV Au 9+ beam with fluences ranging from 3 × 10 11 to 3 × 10 13 ions/cm 2 . The atomic force microscopy images were subjected to power spectral density analysis and roughness analysis using an image analysis software. Clusters were found in the image of as-deposited samples, which indicates that the film growth is dominated by the island growth mode. As-deposited films were amorphous as evidenced from X-ray diffraction; however, high resolution transmission electron microscopy measurements revealed a short range atomic order in the samples with crystallites of size around 3 nm embedded in an amorphous matrix. X-ray diffraction pattern of the as-deposited films after irradiation does not show any appreciable changes, indicating that the passage of swift heavy ions stabilizes the short range atomic ordering, or even creates further amorphization. The crystallinity of the as-deposited Fe–Ni based films was improved by thermal annealing, and diffraction results indicated that ion beam irradiation on annealed samples results in grain fragmentation. On bombarding annealed films, the surface roughness of the films decreased initially, then, at higher fluences it increased. The observed change in surface morphology of the irradiated films is attributed to the interplay between ion induced sputtering, volume diffusion and surface diffusion.

  15. Defects induced by swift heavy ions in the 18R martensite of Cu-Zn-Al alloy

    Zelaya, Eugenia; Tolley, Alfredo; Condo, Adriana; Lovey, Francisco; Schumacher, G

    2003-01-01

    The swift heavy ion incidence over the surface of a given material produces a strong energy deposition in a nanometric scale.Swift heavy ions, of the order of one thousand of MeV, deposit their energy as electronic excitations.This highly localized deposition can induce metastable transformations within the material. For example, in martensitic NiTi alloys irradiated with swift heavy ions, it has been observed changes on the martensitic transformation temperature and amorphous areas induced by the irradiation.In this work, the effects produced by swift heavy ions on the martensitic 18R structure of Cu-Zn-Al alloy (Cu - 12.17 Zn - 17.92 Al, in %at) were analyzed.Crystalline samples were irradiated in a direction close to the [2 1 0] of 18R with Xe + 230 MeV, Au + of 350 MeV and Kr + of 200 MeV ion beams.Defects of the order of nanometers induced by the irradiation were observed by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM).It was also observed, that the average size of the irradiation defects induced by Au + ion is larger than those induced by Xe + and Kr + ions.In this case, no relationship between the observed defects and the energy deposition was found in the 23 keV/nn to 48 keV/nn range

  16. Muon-induced fission

    Polikanov, S.

    1980-01-01

    A review of recent experimental results on negative-muon-induced fission, both of 238 U and 232 Th, is given. Some conclusions drawn by the author are concerned with muonic atoms of fission fragments and muonic atoms of the shape isomer of 238 U. (author)

  17. Dynamical limitations to heavy-ion fusion

    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. 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

    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

  19. Heavy ion induced DNA strand breaks and their repair in diploid cells of the epithelium of the lens

    Heilman, J.

    1987-11-01

    This diploma thesis investigates by means of alkaline unwinding and neutral elution the induction of DNA strand breaks and of rejoining processes as an effect of irradiation with very heavy, accelerated ions. It is found that: The effectiveness of very heavy ions (Z > 18) increases per particle with higher ordinal number, and with increasing velocities. The relative biological effectiveness increases with higher particle masses and lower velocities. The effects of very heavy ions are determined both by the LET and by the particle track extension (specific energy) of the various particles. Heavy ions are much more effective than X-rays with regard to inducing double strand breaks, as compared to DNA single strand breaks induced. Rejoining processes induced by heavy ions have been found to be delayed and incomplete, as compared to the X-ray effects. The number of rejoining processes decreases with rising ordinal number. The experiments indicate that the irradiation with lead or uranium ions most probably makes rejoining impossible. (orig./MG) [de

  20. Heavy ions

    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...

  1. Heavy ions

    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...

  2. Carbon Heavy-ion Radiation Induced Biological effects on Oryza sativa L.

    Zhang, Meng; Sun, Yeqing; Li, Xishan; Gong, Ning; Meng, Qingmei; Liu, Jiawei; Wang, Ting

    2016-07-01

    Large number of researches on rice after spaceflights indicated that rice was a favorable model organism to study biological effects induced by space radiation. The stimulative effect could often be found on rice seedlings after irradiation by low-dose energetic heavy-ion radiation. Spaceflight also could induce stimulative effect on kinds of seeds. To further understand the mechanism of low-dose radiation biological effects and the dose range, the germinated rice seeds which were irradiated by different doses of carbon heavy-ion (0, 0.02, 0.1, 0.2, 1, 2, 5, 10, 15 and 20Gy, LET=27.3keV/µm) were used as materials to study. By investigating the variation of rice phenotype under different doses, we found that 2Gy radiation dose was a dividing point of the phenotypic variation. Transmission electron microscopy was used to observe the variation of mitochondria, chloroplast, endoplasmic reticulum, ribosome and nucleus in mesophyll cell of rice apical meristem at 24 hours after radiation with different doses. The cells were not apparently physiologically damaged when the dose of radiation was less than 2Gy. The number of chloroplast did not change significantly, but the number of mitochondria was significantly increased, and gathered around in the chloroplast and endoplasmic reticulum; the obvious lesion of chloroplast and mitochondria were found at the mesophyll cells when radiation dose was higher than 2Gy. The mitochondria were swelling and appearing blurred crest. The chloroplast and mitochondrial mutation rate increased significantly (pmitochondrial was an important organelle involved in the antioxidative systems, its dysfunction could result in the increase of reactive oxygen species and lipid peroxidation. We found that the growth stimulation induced by low-dose radiation mainly occurred at three-leaf stage along with the increasing activity of antioxidase system and damages of lipid peroxidation. We also found that the relative expression of genes sdhb and aox1a

  3. Characterization of radiation damage induced by swift heavy ions in graphite

    Hubert, Christian

    2016-05-15

    Graphite is a classical material in neutron radiation environments, being widely used in nuclear reactors and power plants as a moderator. For high energy particle accelerators, graphite provides ideal material properties because of the low Z of carbon and its corresponding low stopping power, thus when ion projectiles interact with graphite is the energy deposition rather low. This work aims to improve the understanding of how the irradiation with swift heavy ions (SHI) of kinetic energies in the range of MeV to GeV affects the structure of graphite and other carbon-based materials. Special focus of this project is given to beam induced changes of thermo-mechanical properties. For this purpose the Highly oriented pyrolytic graphite (HOPG) and glassy carbon (GC) (both serving as model materials), isotropic high density polycrystalline graphite (PG) and other carbon based materials like carbon fiber carbon composites (CFC), chemically expanded graphite (FG) and molybdenum carbide enhanced graphite composites (MoC) were exposed to different ions ranging from {sup 131}Xe to {sup 238}U provided by the UNILAC accelerator at GSI in Darmstadt, Germany. To investigate structural changes, various in-situ and off-line measurements were performed including Raman spectroscopy, x-ray diffraction and x-ray photo-electron spectroscopy. Thermo-mechanical properties were investigated using the laser-flash-analysis method, differential scanning calorimetry, micro/nano-indentation and 4-point electrical resistivity measurements. Beam induced stresses were investigated using profilometry. Obtained results provided clear evidence that ion beam-induced radiation damage leads to structural changes and degradation of thermal, mechanical and electrical properties of graphite. PG transforms towards a disordered sp2 structure, comparable to GC at high fluences. Irradiation-induced embrittlement is strongly reducing the lifetime of most high-dose exposed accelerator components. For

  4. Visualization of heavy ion-induced charge production in a CMOS image sensor

    Végh, J; Klamra, W; Molnár, J; Norlin, LO; Novák, D; Sánchez-Crespo, A; Van der Marel, J; Fenyvesi, A; Valastyan, I; Sipos, A

    2004-01-01

    A commercial CMOS image sensor was irradiated with heavy ion beams in the several MeV energy range. The image sensor is equipped with a standard video output. The data were collected on-line through frame grabbing and analysed off-line after digitisation. It was shown that the response of the image sensor to the heavy ion bombardment varied with the type and energy of the projectiles. The sensor will be used for the CMS Barrel Muon Alignment system.

  5. Accelerated heavy ions induced DNA double-strand breaks in yeast cells

    Akpa, T.C.

    1993-01-01

    Yeast cells of strain cerevisiae, were irradiated with monoenergetic heavy ions, X-rays and α particles and assayed for DNA double-strand breaks and cell survival. The method of neutral sucrose gradient velocity sedimentation was used for all heavy-ion experiments because it is a well established technique.The method of pulsed-field gel electrophoresis was used for X-rays, α particles and argon ions. Results show that within the range of LET of the particles used (300 - 10 5 KeV/μm) the induction cross-section for DNA double-strand break is constant between 300 and around 7000 KeV/μm and increases at higher LET values. The inactivation cross-section follow the same trend. The DSB-induction and inactivation cross-section was shown to be linearly related with a slope of (1.01±0.15)/109 gmol-i. The RBE for DSB -induced decreases with LET and tails off at high LET values also. These results when compared with results from literature shows that the trend of induction is first monotonic rise of rate of DSB-induction up to 100keV/μm, followed by a plateau and a further rise which is due to increased effect of energetic γ-rays formed as shown for survival studies and predicted is possible to separate the cell DNA contents into 13 to 15 chromosome bands. The relative decrease in DNA content of the first band as determined by ethidium bromide-UV fluorescence decreases exponentially. The cross-section for DSB-induction determined by this method are (9.8±0.01)dsb/10 12 gmol - 1 Gy - 1, for 80 kV X-rays in haploid 211 yeast strain; (0.04+0.003)dsb/109gmol - 1μm 2 for Am-radioisotope α particles in haploid cells, (0.184±0.034) dsb/10 9 gmol - 1μm 2 in diploid 211*B cells and (0.55±0.04) dsb/10 9 gmol - 1μm 2 for 7MeV Argon ion in the diploid cells. The values are comparable to those obtained with velocity sedimentation technique. However, the reason for the low value obtained for a particle induced DSB in haploid cells is not clear

  6. Quantitative analysis of the epitaxial recrystallization effect induced by swift heavy ions in silicon carbide

    Benyagoub, A.

    2015-01-01

    This paper discusses recent results on the recrystallization effect induced by swift heavy ions (SHI) in pre-damaged silicon carbide. The recrystallization kinetics was followed by using increasing SHI fluences and by starting from different levels of initial damage within the SiC samples. The quantitative analysis of the data shows that the recrystallization rate depends drastically on the local amount of crystalline material: it is nil in fully amorphous regions and becomes more significant with increasing amount of crystalline material. For instance, in samples initially nearly half-disordered, the recrystallization rate per incident ion is found to be 3 orders of magnitude higher than what it is observed with the well-known IBIEC process using low energy ions. This high rate can therefore not be accounted for by the existing IBIEC models. Moreover, decreasing the electronic energy loss leads to a drastic reduction of the recrystallization rate. A comprehensive quantitative analysis of all the experimental results shows that the SHI induced high recrystallization rate can only be explained by a mechanism based on the melting of the amorphous zones through a thermal spike process followed by an epitaxial recrystallization initiated from the neighboring crystalline regions if the size of the latter exceeds a certain critical value. This quantitative analysis also reveals that recent molecular dynamics calculations supposed to reproduce this phenomenon are wrong since they overestimated the recrystallization rate by a factor ∼40.

  7. Heavy ion inertial fusion

    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

  8. Dynamical limitations to heavy ion fusion

    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

  9. Sequential and double sequential fission observed in heavy ion interaction of (11.67 MeV/u){sup 197}Au projectile with {sup 197}Au target

    Nasir, Tabassum [Gomal University, Dera Ismail Khan (Pakistan). Dept. of Physics; Khan, Ehsan Ullah [COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan). Dept. of Physics; Baluch, Javaid Jahan [COMSATS Institute of Information Technology (CIIT), Abbottabad, (Pakistan). Dept. of Environmental Sciences; Shafi-Ur-Rehman, [PAEC, Dera Ghazi Khan (Pakistan). ISL Project; Matiullah, [PINSTECH, Nilore, Islamabad (Pakistan). Physics Div.; Rafique, Muhammad [University of Azad Jammu and Kashmir, Muzaffarabad (Pakistan). Dept. of Physics

    2009-09-15

    The heavy ion interaction of 11.67 MeV/u {sup 197}Au+ {sup 197}Au has been investigated using mica as a passive detector. By employing Solid State Nuclear Track Detection Technique the data of elastic scattering as well as inelastic reaction channel was collected. The off-line data analysis of multi-pronged events was performed by measuring the three-dimensional geometrical coordinates of correlated tracks on event-by-event basis. Multi pronged events observed in this reaction were due to sequential and double sequential fission. Using a computer code PRONGY based on the procedure of internal calibration, it was possible to derive quantities like mass transfer, total kinetic energy loss and scattering angles. (author)

  10. Sequential and double sequential fission observed in heavy ion interaction of (11.67 MeV/u)197Au projectile with 197Au target

    Nasir, Tabassum; Khan, Ehsan Ullah; Baluch, Javaid Jahan; Shafi-Ur-Rehman; Matiullah; Rafique, Muhammad

    2009-01-01

    The heavy ion interaction of 11.67 MeV/u 197 Au+ 197 Au has been investigated using mica as a passive detector. By employing Solid State Nuclear Track Detection Technique the data of elastic scattering as well as inelastic reaction channel was collected. The off-line data analysis of multi-pronged events was performed by measuring the three-dimensional geometrical coordinates of correlated tracks on event-by-event basis. Multi pronged events observed in this reaction were due to sequential and double sequential fission. Using a computer code PRONGY based on the procedure of internal calibration, it was possible to derive quantities like mass transfer, total kinetic energy loss and scattering angles. (author)

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

    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

  12. Phase transformation induced by swift heavy ion irradiation of pure metals

    Dammak, H.; Dunlop, A.; Lesueur, D.

    1996-01-01

    It is now unambiguously established that high electronic energy deposition (HEED), obtained by swift heavy ion irradiation, plays an important role in the damage processes of pure metallic targets: (i) annealing of the defects created by elastic collisions in Fe, Nb, Ni and Pt, and (ii) creation of additional defects in Co, Fe, Ti and Zr. For Ti, we have recently evidenced by transmission electron microscopy observations that the damage creation by HEED is very important and leads to a phase transformation. Titanium evolves from the equilibrium hcp alpha-phase to the high pressure omega-phase. We studied the influence of three parameters on this phase transformation: ion fluence, electronic stopping power and irradiation temperature. The study of Ti and the results concerning other metals (Fe, Zr, etc.) and the semi-metal Bi allow us to propose criteria to predict in which metals HEED could induce damage: those which undergo a phase transformation under high pressure. As a matter of fact, beryllium is strongly damaged when submitted to HEED and seems to behave very similarly to titanium. The fact that such phase changes from a crystalline form to another form were only observed in those metals in which high pressure phases exist in the pressure-temperature diagram, strongly supports the Coulomb explosion model in which the generation of (i) a shock wave and (ii) collective atomic movements are invoked to account for the observed damage creation. (orig.)

  13. Heavy-Ions induced SEE effects measurements for the STRURED ASIC

    De Robertis, G.; Ranieri, A. [INFN Bari, Via Orabona 4, 70126 Bari (Italy); Gabrielli, A. [Universita degli Studi di Bologna and INFN-Bologna, Viale B. Pichat, 6/2, 40127 Bologna (Italy); Candelori, A.; Mattiazzo, S.; Pantano, D.; Tessaro, M. [INFN-Padova, Via Marzolo 8, 35131 Padova (Italy)

    2011-06-15

    With the aim of developing a radiation-tolerant circuit, a digital test microelectronic device has been designed and fabricated by using a standard-cell library of a 130-nm CMOS technology, including three different architectures to correct circuit malfunctions induced by the occurrence of Single-Event Effects (SEE's). SEE's are one of the main reasons of failures affecting electronic circuits operating in harsh radiation environments, such as in experiments performed at High Energy Physics (HEP) colliders or in apparatus to be operated in Space. On the same digital circuit specifically designed, three redundant architectures added to a basic scheme have been implemented in order to evaluate their effectiveness to prevent SEE. This may give an indication on their usage in future digital circuits specifically designed for the above mentioned applications. We present the results of SEE cross section measurements performed on a test digital device exposed to a high energy heavy ion beam at the SIRAD irradiation facility of the INFN National Laboratories of Legnaro (Padova Italy).

  14. Heavy-Ions induced SEE effects measurements for the STRURED ASIC

    De Robertis, G.; Ranieri, A.; Gabrielli, A.; Candelori, A.; Mattiazzo, S.; Pantano, D.; Tessaro, M.

    2011-01-01

    With the aim of developing a radiation-tolerant circuit, a digital test microelectronic device has been designed and fabricated by using a standard-cell library of a 130-nm CMOS technology, including three different architectures to correct circuit malfunctions induced by the occurrence of Single-Event Effects (SEE's). SEE's are one of the main reasons of failures affecting electronic circuits operating in harsh radiation environments, such as in experiments performed at High Energy Physics (HEP) colliders or in apparatus to be operated in Space. On the same digital circuit specifically designed, three redundant architectures added to a basic scheme have been implemented in order to evaluate their effectiveness to prevent SEE. This may give an indication on their usage in future digital circuits specifically designed for the above mentioned applications. We present the results of SEE cross section measurements performed on a test digital device exposed to a high energy heavy ion beam at the SIRAD irradiation facility of the INFN National Laboratories of Legnaro (Padova Italy).

  15. Swift heavy ion induced modifications in optical and electrical properties of cadmium selenide thin films

    Choudhary, Ritika; Chauhan, Rishi Pal

    2017-07-01

    The modification in various properties of thin films using high energetic ion beam is an exciting area of basic and applied research in semiconductors. In the present investigations, cadmium selenide (CdSe) thin films were deposited on ITO substrate using electrodeposition technique. To study the swift heavy ion (SHI) induced effects, the deposited thin films were irradiated with 120 MeV heavy Ag9+ ions using pelletron accelerator facility at IUAC, New Delhi, India. Structural phase transformation in CdSe thin film from metastable cubic phase to stable hexagonal phase was observed after irradiation leading to decrease in the band gap from 2.47 eV to 2.12 eV. The phase transformation was analyzed through X-ray diffraction patterns. During SHI irradiation, Generation of high temperature and pressure by thermal spike along the trajectory of incident ions in the thin films might be responsible for modification in the properties of thin films.[Figure not available: see fulltext.

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

    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...

  17. Swift heavy ions induced material reorganization on surface of barium fluoride thin films

    Pandey, Ratnesh K.; Kumar, Manvendra; Pandey, Avinash C.; Khan, Saif A.; Singh, Udai B.; Tripathi, Ambuj; Avasthi, D.K.

    2014-01-01

    Swift heavy ions induced thermal spike is found to result in a highly excited nanometric cylindrical zone in insulating materials. The resulting transient local melting (taking place on ps timescale) results in formation of a defect-rich or amorphous latent track. In the present work we are reporting evolution of lamellae structure on surface of BaF_2 thin films due to irradiation with 100 MeV Au"+"8 ions. These thin films of BaF_2 have been deposited on glass substrate using electron beam evaporation method and have a thickness of 200 nm. Irradiation was performed at liquid nitrogen temperature and at an angle of incidence of 15° shows the scanning electron microscopic (SEM) images of evolution of lamellae pattern. A cracking perpendicular to the beam direction at low fluences of 5x10"1"2 ions/cm"2 is observed, while at higher fluences of 2x10"1"3 ions/cm"2, the material started to shrink. After application of further high fluences up to 2x10"1"4 ions/cm"2, the BaF_2 layer was reorganized in form of lamellae having orientation as found for the cracks and normal to the beam direction. A self-organized phenomenon in SHI irradiated NiO layers, resulting in formation of 100-nm-thick and 1-µm-high NiO lamellae has also been observed. (author)

  18. Neutron spectra, recoil momenta and PI0 production cross sections for reactions induced by 10-100 MeV/nucleon heavy ions

    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

  19. Polarization phenomena in heavy-ion reactions

    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

  20. Heavy-ion induced desorption yields of cryogenic surfaces bombarded with 4.2 MeV/u lead ions

    Mahner, E; Evans, L; Kollmus, H; Küchler, D; Scrivens, R; Severin, D; Wengenroth, M; CERN. Geneva. ATS Department

    2011-01-01

    The ion-induced desorption experiment, installed in the CERN Heavy-Ion Accelerator LINAC 3, has been used to study the dynamic outgassing of cryogenic surfaces. Two different targets, bare and goldcoated copper, were bombarded under perpendicular impact with 4.2 MeV/u Pb54+ ions. Partial pressure rises of H2, CH4, CO, and CO2 and effective desorption yields were measured at 300, 77, and 6.3 K using single shot and continuous ion bombardment techniques. We find that the heavy-ion-induced desorption yield is temperature dependent and investigate the influence of CO gas cryosorbed at 6.3 K. The gain in desorption yield reduction at cryogenic temperature vanishes after several monolayers of CO are cryosorbed on both targets. In this paper we describe the new cryogenic target assembly, the temperature-dependent pressure rise, desorption yield, and gas adsorption measurements.

  1. Mechanism of the monoclinic-to-tetragonal phase transition induced in zirconia and hafnia by swift heavy ions

    Benyagoub, Abdenacer

    2005-01-01

    Recent results demonstrated that defect formation or amorphization are not the only structural changes induced by swift heavy ions in crystalline materials and that under certain circumstances crystalline-to-crystalline phase transitions can also occur. For instance, it was found that both zirconia and hafnia transform from the monoclinic to the tetragonal phase with a kinetics involving a double ion impact process. In order to understand the origin of this ion-beam induced phase transition, the behavior of these twin oxides was analyzed and compared. In fact, the likeness of these materials offered the unique opportunity to impose drastic constraints on the possible models proposed to explain the creation of atomic displacements in the wake of swift heavy ions. This comparison clearly suggests that the thermal spike is the most appropriate process which governs the transition from the monoclinic to the tetragonal phase in zirconia and hafnia

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

    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

  3. Swift heavy ion irradiation induced electrical degradation in deca-nanometer MOSFETs

    Ma, Yao; Yang, Zhimei; Gong, Min [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Gao, Bo; Li, Yun; Lin, Wei; Li, Jinbo; Xia, Zhuohui [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)

    2016-09-15

    In this work, degradation of the electrical characteristics of 65 nm nMOSFETs under swift heavy ion irradiation is investigated. It was found that a heavy ion can generate a localized region of physical damage (ion latent track) in the gate oxide. This is the likely cause for the increased gate leakage current and soft breakdown (SBD) then hard breakdown (HBD) of the gate oxide. Except in the case of HBD, the devices retain their functionality but with degraded transconductance. The degraded gate oxide exhibits early breakdown behavior compatible with the model of defect generation and percolation path formation in the percolation model.

  4. Heavy Ion Microbeam- and Broadbeam-Induced Current Transients in SiGe HBTs

    Pellish, Jonathan A.; Reed, R. A.; McMorrow, D.; Vizkelethy, G.; Ferlet-Cavrois, V.; Baggio, J.; Duhamel, O.; Moen, K. A.; Phillips, S. D.; Diestelhorst, R. M.; hide

    2009-01-01

    IBM 5AM SiGe HBT is device-under-test. High-speed measurement setup. Low-impedance current transient measurements. SNL, JYFL, GANIL. Microbeam to broadbeam position inference. Improvement to state-of-the-art. Microbeam (SNL) transients reveal position dependent heavy ion response, Unique response for different device regions Unique response for different bias schemes. Similarities to TPA pulsed-laser data. Broadbeam transients (JYFL and GANIL) provide realistic heavy ion response. Feedback using microbeam data. Overcome issues of LET and ion range with microbeam. **Angled Ar-40 data in full paper. Data sets yield first-order results, suitable for TCAD calibration feedback.

  5. Considerations about projectile and target X-rays induced during heavy ion bombardment

    Fernandes, F.; Bauer, D. V.; Duarte, A.; Ferrari, T. M.; Niekraszewicz, L. A. B.; Amaral, L.; Dias, J. F.

    2018-02-01

    In this work we present some results concerning the X-rays emitted by heavy ions during target bombardment. In this case, Cl4+ and Cl5+ ions with energies from 4 MeV to 10 MeV were employed to irradiate vitreous carbon planchets. Moreover, total X-ray production cross sections of titanium X-rays induced by chlorine ions were obtained as well for the same energy range. Only inner shell transitions were considered in the present work. The titanium target consisted of a thin film deposited over vitreous carbon planchets. The results indicate that the projectile X-ray yields increase as a function of the bombarding energy for the present energy range. Effects due to projectile charge state appears to be of minor importance at these low ion velocities. It is shown that a simple exponential function can represent the continuum background of such complex spectra. The chlorine transition rates Kβ/Kα obtained from chlorine acting as a projectile interacting with a carbon target are about half the value when compared to the chlorine Kβ/Kα ratios obtained when a LiCl target is bombarded with C+ and C3+ ions with energies from 2 MeV to 6 MeV. As far as the total X-ray production cross sections of Ti induced by chlorine ions are concerned, the ECPSSR theory underestimates the Ti total X-rays production cross sections by several orders of magnitude. The role of electron capture and possible mechanisms responsible for these effects are discussed.

  6. Heavy-ion-induced bystander killing of human lung cancer cells. Role of gap junctional intercellular communication

    Harada, Kosaku; Nonaka, Tetsuo; Hamada, Nobuyuki; Sakurai, Hideyuki; Hasegawa, Masatoshi; Kobayashi, Yasuhiko; Nakano, Takashi; Funayama, Tomoo; Kakizaki, Takehiko

    2009-01-01

    The aim of the present study was to clarify the mechanisms of cell death induced by heavy-ion irradiation focusing on the bystander effect in human lung cancer A549 cells. In microbeam irradiation, each of 1, 5, and 25 cells under confluent cell conditions was irradiated with 1, 5, or 10 particles of carbon ions (220 MeV), and then the surviving fraction of the population was measured by a clonogenic assay in order to investigate the bystander effect of heavy-ions. In this experiment, the limited number of cells (0.0001-0.002%, 5-25 cells) under confluent cell conditions irradiated with 5 or 10 carbon ions resulted in an exaggerated 8-14% increase in cell death by clonogenic assay. However, these overshooting responses were not observed under exponentially growing cell conditions. Furthermore, these responses were inhibited in cells treated with an inhibitor of gap junctional intercellular communication (GJIC), whereas they were markedly enhanced by the addition of a stimulator of GJIC. The present results suggest that bystander cell killing by heavy-ions was induced mainly by direct cell-to-cell communication, such as GJIC, which might play important roles in bystander responses. (author)

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

    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.

  8. Cell cycle delays induced by heavy ion irradiation of synchronous mammalian cells

    Scholz, M.; Kraft-Weyrather, W.; Ritter, S.; Kraft, G.

    1994-01-01

    Cell cycle delays in V79 Chinese hamster cells induced by heavy ion exposure have been investigated using flow cytometry. Synchronous cell populations in G 1 -, S- and late-S/G 2 M-phase were used. Cells were irradiated with particles from Z = 10 (neon) up to Z = 96 (uranium) in the energy range from 2.4 to 17.4 MeV/u and the LET range from 415 to 16225 keV/μm at the UNILAC at GSI, Darmstadt. For comparison, experiments with 250 kV X-rays were performed. For light particles like neon, cell cycle perturbations comparable to those after X-ray irradiation were found, and with increasing LET an increasing delay per particle traversal was observed. For the highest LET-values, extended delays in G 1 -, S- and G 2 M-phase were detected immediately after irradiation. A large fraction of the cells remained in S-phase or G 2 M-phase up to 48 h or longer after irradiation. No significant cell age dependence of cycle delays was detected for the very high LET values. In addition to cell cycle delays, two effects related to the DNA-content as determined by flow cytometry were found after irradiation with very high LET particles, which were attributed to cell fusion and to drastic morphological changes of the cells. Estimations based on the dose deposited by a single particle hit in the cell nucleus and the actual number of hits show, that the basic trend of the experimental results can be explained by the stochastic properties of particle radiation. (orig.)

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

    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

  10. Protons and heavy ions induced stuck bits on large capacity RAMs

    Duzellier, S; Falguere, D; Ecoffet, R [Centre National d` Etudes Spatiales (CNES), 31 - Toulouse (France)

    1994-12-31

    A semi-permanent imprint effect has been observed, on large capacity memories (static and dynamic), during heavy ion and proton irradiations. The experimental circumstances of stuck bits occurrence are described and the influence of irradiation conditions discussed. A total dose testing complete the investigation. (author). 10 refs., 5 figs., 3 tabs.

  11. Heavy-ion-induced sucrose radicals investigated using EPR and UV spectroscopy

    Nakagawa, Kouichi; Karakirova, Yordanka; Yordanov, Nicola D.

    2015-01-01

    The potential use of a sucrose dosimeter for estimating both linear energy transfer (LET) and the absorbed dose of heavy ion and X-ray radiation was investigated. The stable free radicals were produced when sucrose was irradiated with heavy ions, such as helium, carbon, silicon and neon ions, and when the X-ray radiation was similar to the obtained electron paramagnetic resonance (EPR) spectra, which were ∼7 mT wide and composed of several hyperfine structures. In addition, the total spin concentration resulting from heavy-ion irradiation increased linearly as the absorbed dose increased, and decreased logarithmically as the LET increased. These empirical relations imply that the LET at a certain dose can be determined from the spin concentration. For sucrose and alanine, both cross-sections following C-ion irradiation with a 50 Gy dose were ∼1.3 × 10−12 [μm2], taking into account the molecular size of the samples. The values of these cross-sections imply that multiple ionizing particles were involved in the production of stable radicals. Furthermore, UV absorbance at 267 nm of an aqueous solution of irradiated sucrose was found to linearly increase with increasing absorbed dose. Therefore, the EPR and UV results suggest that sucrose can be a useful dosimeter for heavy-ion irradiation. PMID:25480828

  12. Defects induced magnetic transition in Co doped ZnS thin films: Effects of swift heavy ion irradiations

    Patel, Shiv P., E-mail: shivpoojanbhola@gmail.com [Physics Department, University of Allahabad, Allahabad 211002 (India); Pivin, J.C. [CSNSM, IN2P3-CNRS, Batiment 108, F-91405 Orsay Campus (France); Patel, M.K; Won, Jonghan [Materials Science and Technology Division, MST-8, P.O.Box 1663, Mail Stop G755, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Chandra, Ramesh [Nanoscience Laboratory, IIC, Indian Institute of Technology, Roorkee 247667 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Kumar, Lokendra [Physics Department, University of Allahabad, Allahabad 211002 (India)

    2012-07-15

    The effect of swift heavy ions (SHI) on magnetic ordering in ZnS thin films with Co ions substituted on Zn sites is investigated. The materials have been synthesized by pulsed laser deposition on substrates held at 600 Degree-Sign C for obtaining films with wurtzite crystal structure and it showed ferromagnetic ordering up to room temperature with a paramagnetic component. 120 MeV Ag ions have been used at different fluences of 1 Multiplication-Sign 10{sup 11} ions/cm{sup 2} and 1 Multiplication-Sign 10{sup 12} ions/cm{sup 2} for SHI induced modifications. The long range correlation between paramagnetic spins on Co ions was destroyed by irradiation and the material became purely paramagnetic. The effect is ascribed to the formation of cylindrical ion tracks due to the thermal spikes resulting from electron-phonon coupling. - Highlights: Black-Right-Pointing-Pointer Effect of swift heavy ions on magnetic ordering in Co doped ZnS thin films are presented. Black-Right-Pointing-Pointer Magnetization in the pristine films is composed of ferromagnetic and paramagnetic components. Black-Right-Pointing-Pointer The films become purely paramagnetic after swift heavy ions irradiation. Black-Right-Pointing-Pointer The magnetic transition is ascribed to the formation of ion track (or cylindrical defects) due to the thermal spikes.

  13. Phenomenology of the plastic flow of amorphous solids induced by heavy-ion bombardment

    Klaumuenzer, S.; Benyagoub, A.

    1991-01-01

    Amorphous solids exhibit at temperatures far below the glass transition plastic flow when bombarded with fast heavy ions (kinetic energy ∼1 MeV/u). The dimensions perpendicular to the ion beam grow whereas the sample dimension parallel to the ion beam shrinks. The strain tensor describing phenomenologically these dimensional changes is derived from symmetry considerations and compared with experiment. Particular attention is devoted to angular changes, which have not been discussed in this context so far

  14. Heavy ion induced X-ray emission work at the TANDAR laboratory in Buenos Aires

    Ozafran, M.J.; Hojman, D.; Menendez, J.J.; Davidson, M.

    1995-01-01

    The PIXE technique, using heavy ions beams, has been implemented at the TANDAR tandem facility in Buenos Aires. Mainly 16 O beams in the bombarding energy range E=30-50 MeV have been used and a systematic measurement of X-ray production cross sections has been performed. The technique has been applied to a variety of subjects, including environmental, biomedical and industrial problems. (orig.)

  15. Swift heavy ions induced irradiation effects in monolayer graphene and highly oriented pyrolytic graphite

    Zeng, J.; Yao, H.J.; Zhang, S.X.; Zhai, P.F.; Duan, J.L.; Sun, Y.M.; Li, G.P.; Liu, J.

    2014-01-01

    Monolayer graphene and highly oriented pyrolytic graphite (HOPG) were irradiated by swift heavy ions ( 209 Bi and 112 Sn) with the fluence between 10 11 and 10 14 ions/cm 2 . Both pristine and irradiated samples were investigated by Raman spectroscopy. It was found that D and D′ peaks appear after irradiation, which indicated the ion irradiation introduced damage both in the graphene and graphite lattice. Due to the special single atomic layer structure of graphene, the irradiation fluence threshold Φ th of the D band of graphene is significantly lower ( 11 ions/cm 2 ) than that (2.5 × 10 12 ions/cm 2 ) of HOPG. The larger defect density in graphene than in HOPG indicates that the monolayer graphene is much easier to be damaged than bulk graphite by swift heavy ions. Moreover, different defect types in graphene and HOPG were detected by the different values of I D /I D′ . For the irradiation with the same electronic energy loss, the velocity effect was found in HOPG. However, in this experiment, the velocity effect was not observed in graphene samples irradiated by swift heavy ions

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

    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

  17. Heavy ion transfer reactions

    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.)

  18. Flux pinning by heavy-ion-irradiation induced linear defects in YBa2Cu3O7 epitaxial films

    Budhani, R.C.; Zhu, Y.; Suenaga, M.

    1992-01-01

    We report some transport measurements carried out to study flux pinning by heavy-ion-irradiation induced linear defects in Y 1 Ba 2 Cu 3 O 7 films. Our results show that in these in situ deposited films containing a large concentration of defects frozen-in at the time of film growth, a marginal enhancement in critical current density occurs when the density of linear defects 10 /cm 2 , and their diameter of the order of coherence length. This criterion is satisfied by Ag +21 ions. The damage due to Au +24 ions is much too severe to improve the J c

  19. Simulation of thermal-neutron-induced single-event upset using particle and heavy-ion transport code system

    Arita, Yutaka; Kihara, Yuji; Mitsuhasi, Junichi; Niita, Koji; Takai, Mikio; Ogawa, Izumi; Kishimoto, Tadafumi; Yoshihara, Tsutomu

    2007-01-01

    The simulation of a thermal-neutron-induced single-event upset (SEU) was performed on a 0.4-μm-design-rule 4 Mbit static random access memory (SRAM) using particle and heavy-ion transport code system (PHITS): The SEU rates obtained by the simulation were in very good agreement with the result of experiments. PHITS is a useful tool for simulating SEUs in semiconductor devices. To further improve the accuracy of the simulation, additional methods for tallying the energy deposition are required for PHITS. (author)

  20. Heavy ion-induced chromosomal aberrations analyzed by fluorescence in situ hybridization

    Durante, M.; Gialanella, G.; Grossi, G.; Pugliese, M.; Cella, L.; Greco, O.; George, K.; Yang, T.C.

    1997-01-01

    We have investigated the effectiveness of heavy ions in the induction of chromosomal aberrations in mammalian cells by the recent technique of fluorescence in situ hybridization (FISH) with whole-chromosome probes. FISH-painting was used both in metaphase and interphase (prematurely condensed) chromosomes. The purpose of our experiments was to address the following problems: (a) the ratio of different types of aberrations as a function of radiation quality (search for biomarkers); (b) the ratio between aberrations scored in interphase and metaphase as a function of radiation quality (role of apoptosis); (c) differences between cytogenetic effects produced by different ions at the same LET (role of track structure). (orig./MG)

  1. Dynamically induced spin-dependent interaction in the elastic scattering of heavy-ions

    Imanishi, B.; Oertzen, W. von.

    1982-02-01

    Dynamical polarization effect in heavy-ion elastic scattering is investigated in the framework of the coupled-reaction-channel theory. By using the adiabatic approximation at low incident energies, this effect is expressed as a spin-orbit (L vector.S vector) interaction with a L vector and S vector independent radial function. The strength of the (L vector.S vector) interaction calculated for the 12 C + 13 C system is in the same order of magnitude as deduced from experiments and is about two orders of magnitude larger than that obtained from the folding model calculation. (author)

  2. Heavy ion-induced chromosomal aberrations analyzed by fluorescence in situ hybridization

    Durante, M; Gialanella, G; Grossi, G; Pugliese, M [Univ. ` ` Federico II` ` , Naples (Italy). Dept. of Physics; [INFN, Naples (Italy); Cella, L; Greco, O [Univ. ` ` Federico II` ` , Naples (Italy). Dept. of Physics; Furusawa, Y [NIRS, Chiba (Japan); George, K; Yang, T C [NASA Lyndon B. Johnson Space Center, Houston, TX (United States)

    1997-09-01

    We have investigated the effectiveness of heavy ions in the induction of chromosomal aberrations in mammalian cells by the recent technique of fluorescence in situ hybridization (FISH) with whole-chromosome probes. FISH-painting was used both in metaphase and interphase (prematurely condensed) chromosomes. The purpose of our experiments was to address the following problems: (a) the ratio of different types of aberrations as a function of radiation quality (search for biomarkers); (b) the ratio between aberrations scored in interphase and metaphase as a function of radiation quality (role of apoptosis); (c) differences between cytogenetic effects produced by different ions at the same LET (role of track structure). (orig./MG)

  3. Spin-isospin excitations induced by heavy ions at Saturne energies

    Hennino, T.

    1989-01-01

    Our program on the Spin-Isospin excitations started with the ( 3 He, 3 H) and ( 2 H, 2 He) reactions was extended with the heavy ion beams available at Saturne ( 12 C, 16 0, 20 Ne and 40 Ar) to study systematically the Δ excitation energy region. Projectile-ejectile dependences were measured. The Δ peak shift appears as a common feature in all charge exchange reactions. The first cross section calculations for the ( 12 C, 12 N) reaction are in good quantitative agreement with the data [fr

  4. Relativistic Coulomb Fission

    Norbury, John W.

    1992-01-01

    Nuclear fission reactions induced by the electromagnetic field of relativistic nuclei are studied for energies relevant to present and future relativistic heavy ion accelerators. Cross sections are calculated for U-238 and Pu-239 fission induced by C-12, Si-28, Au-197, and U-238 projectiles. It is found that some of the cross sections can exceed 10 b.

  5. Rapid thermal and swift heavy ion induced annealing of Co ion implanted GaN films

    Baranwal, V.; Pandey, A. C.; Gerlach, J. W.; Rauschenbach, B.; Karl, H.; Kanjilal, D.; Avasthi, D. K.

    2008-01-01

    Thin epitaxial GaN films grown on 6H-SiC(0001) substrates were implanted with 180 keV Co ions at three different fluences. As-implanted samples were characterized with secondary ion mass spectrometry and Rutherford backscattering spectrometry to obtain the Co depth profiles and the maximum Co concentrations. As-implanted samples were annealed applying two different techniques: rapid thermal annealing and annealing by swift heavy ion irradiation. Rapid thermal annealing was done at two temperatures: 1150 deg. C for 20 s and 700 deg. C for 5 min. 200 MeV Ag ions at two fluences were used for annealing by irradiation. Crystalline structure of the pristine, as-implanted, and annealed samples was investigated using x-ray diffraction, and the results were compared. Improvement of the crystalline quality was observed for rapid thermal annealed samples at the higher annealing temperature as confirmed with rocking curve measurements. The results indicate the presence of Co clusters in these annealed samples. Swift heavy ion irradiation with the parameters chosen for this study did not lead to a significant annealing

  6. Study on the desorption yield for natural botanic sample induced by energetic heavy ions

    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...

  7. Study on the desorption yield for natural botanic sample induced by energetic heavy ions

    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

  8. Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs

    Kotani, Eiji; Furusawa, Toshiharu [Kyoto Inst. of Tech. (Japan). Faculty of Textile Science; Nagaoka, Shunji [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Sciences] [and others

    2002-12-01

    In order to investigate whether eggs of the black-striped strain (P{sup S}) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs. Incidence of the mutation as induced by carbon ion beams for 15-day old eggs was higher for eggs that had been kept at 15 deg C than those kept at 25 deg C. Neon beam irradiation of diapause eggs displayed dose- and linear energy transfer (LET)-dependent effects, causing a maximal rate of the mutation at 150 keV/{mu}m. These results confirm that B. mori eggs represent valid models for estimating the biological effects of cosmic radiation. (author)

  9. Study of the modifications induced in AlxGa1-xN semiconductors under swift heavy ion irradiation

    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

  10. Grafting of acrylic acid on etched latent tracks induced by swift heavy ions on polypropylene films

    Mazzei, R.; Fernandez, A.; Garcia Bermudez, G.; Torres, A.; Gutierrez, M.C.; Magni, M.; Celma, G.; Tadey, D.

    2008-01-01

    In order to continue with a systematic study that include different polymers and monomers, the residual active sites produced by heavy ion beams, that remain after the etching process, were used to start the grafting process. To produce tracks, foils of polypropylene (PP) were irradiated with 208 Pb of 25.62 MeV/n. Then, these were etched and grafted with acrylic acid (AA) monomers. Experimental curves of grafting yield as a function of grafting time with the etching time as a parameter were measured. Also, the grating yield as a function of the fluence and etching time was obtained. In addition, the permeation of solutions, with different pH, through PP grafted foils was measured

  11. Differential effects of p53 on bystander phenotypes induced by gamma ray and high LET heavy ion radiation

    He, Mingyuan; Dong, Chen; Konishi, Teruaki; Tu, Wenzhi; Liu, Weili; Shiomi, Naoko; Kobayashi, Alisa; Uchihori, Yukio; Furusawa, Yoshiya; Hei, Tom K.; Dang, Bingrong; Shao, Chunlin

    2014-04-01

    High LET particle irradiation has several potential advantages over γ-rays such as p53-independent response. The purpose of this work is to disclose the effect of p53 on the bystander effect induced by different LET irradiations and underlying mechanism. Lymphocyte cells of TK6 (wild type p53) and HMy2.CIR (mutated p53) were exposed to either low or high LET irradiation, then their mitochondrial dysfunction and ROS generation were detected. The micronuclei (MN) induction in HL-7702 hepatocytes co-cultured with irradiated lymphocytes was also measured. It was found that the mitochondrial dysfunction, p66Shc activation, and intracellular ROS were enhanced in TK6 but not in HMy2.CIR cells after γ-ray irradiation, but all of them were increased in both cell lines after carbon and iron irradiation. Consistently, the bystander effect of MN formation in HL-7702 cells was only triggered by γ-irradiated TK6 cells but not by γ-irradiated HMy2.CIR cells. But this bystander effect was induced by both lymphocyte cell lines after heavy ion irradiation. PFT-μ, an inhibitor of p53, only partly inhibited ROS generation and bystander effect induced by 30 keV/μm carbon-irradiated TK6 cells but failed to suppress the bystander effect induced by the TK6 cells irradiated with either 70 keV/μm carbon or 180 keV/μm iron. The mitochondrial inhibitors of rotenone and oligomycin eliminated heavy ion induced ROS generation in TK6 and HMy2.CIR cells and hence diminished the bystander effect on HL-7702 cells. These results clearly demonstrate that the bystander effect is p53-dependent for low LET irradiation, but it is p53-independent for high LET irradiation which may be because of p53-independent ROS generation due to mitochondrial dysfunction.

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

    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-.

  13. Vitamin D-metabolites from human plasma and mass spectrometric analysis by fast heavy ion induced desorption

    Fohlman, J; Peterson, P A [Uppsala Univ. (Sweden). Dept. of Cell Research; Kamensky, I; Hakansson, P; Sundqvist, B [Tandemacceleratorlaboratoriet, Uppsala (Sweden)

    1982-07-01

    D-vitamin metabolites have been isolated from human serum employing chromatographic techniques. The serum carrier protein for vitamin D (DBP) was first isolated by immunosorbent chromatography. Lipid ligands associated with DBP were then extracted with hexane and separated by high pressure liquid chromatography (HPLC). Detection of vitamin D metabolites by their absorbance of ultraviolet light is not sufficiently sensitive to monitor all vitamin D derivatives from a few millilitres of serum. Therefore, further analyses are necessary to quantitative these compounds. We have begun to develop a mass spectrometric method to achieve a reliable, quantitative procedure. As a first step towards this goal a number of pure samples of vitamin D compounds have been studied in a time-of-flight mass spectrometer based on fast heavy ion induced desorption. All vitamin D compounds examined could be detected and identified by their molecular ion and fragment spectra.

  14. Effects of momentum-dependent symmetry potential on heavy-ion collisions induced by neutron-rich nuclei

    Li Baoan; Das, Champak B.; Das Gupta, Subal; Gale, Charles

    2004-01-01

    Using an isospin- and momentum-dependent transport model we study effects of the momentum-dependent symmetry potential on heavy-ion collisions induced by neutron-rich nuclei. It is found that symmetry potentials with and without the momentum-dependence but corresponding to the same density-dependent symmetry energy E sym (ρ) lead to significantly different predictions on several E sym (ρ)-sensitive experimental observables especially for energetic nucleons. The momentum- and density-dependence of the symmetry potential have to be determined simultaneously in order to extract the E sym (ρ) accurately. The isospin asymmetry of midrapidity nucleons at high transverse momenta is particularly sensitive to the momentum-dependence of the symmetry potential. It is thus very useful for investigating accurately the equation of state of dense neutron-rich matter

  15. Vitamin D-metabolites from human plasma and mass spectrometric analysis by fast heavy ion induced desorption

    Fohlman, J.; Peterson, P.A.

    1982-01-01

    D-vitamin metabolites have been isolated from human serum employing chromatographic techniques. The serum carrier protein for vitamin D (DBP) was first isolated by immunosorbent chromatography. Lipid ligands associated with DBP were then extracted with hexane and separated by high pressure liquid chromatography (HPLC). Detection of vitamin D metabolites by their absorbance of ultraviolet light is not sufficiently sensitive to monitor all vitamin D derivatives from a few millilitres of serum. Therefore, further analyses are necessary to quantitative these compounds. We have begun to develop a mass spectrometric method to achieve a reliable, quantitative procedure. As a first step towards this goal a number of pure samples of vitamin D compounds have been studied in a time-of-flight mass spectrometer based on fast heavy ion induced desorption. All vitamin D compounds examined could be detected and identified by their molecular ion and fragment spectra. (orig.)

  16. Swift heavy ion induced de wetting of metal oxide thin films on silicon

    Bolse, T.; Paulus, H.; Bolse, W.

    2006-01-01

    We have observed that thin oxide coatings (NiO, Fe 2 O 3 ) tend to dewet their Si substrate when being bombarded with swift heavy ions (350-600 MeV Au ions) even though the irradiation was carried out about 80 K and hence, the films never reached their melting point. Scanning electron and atomic force microscopy reveal a surprising similarity of the dewetting morphologies with those observed for molten polymer films on Si, which have recently been reported by others [S. Herminghaus, K. Jakobs, K. Mecke, J. Bischof, A. Fery, M. Ibn-Elhaj, S. Schlagowsky, Science 282 (1998) 916; R. Seemann, S. Herminghaus, K. Jacobs, J. Phys.: Condens. Matter 13 (2001) 4925]. Like in that cases also here heterogeneous and homogeneous hole nucleation could be identified. Heterogeneous nucleation is less pronounced in Fe 2 O 3 /Si than in NiO/Si. The occurrence of spinodal-like dewetting cannot be detected unambiguously. The dewetting kinetics were determined by means of Rutherford backscattering spectroscopy and found to slightly differ for the two compounds. The dewetting kinetics as well as the final dewetting pattern strongly depend on the initial film thicknesses. No dewetting occurs for film thicknesses above about 150 nm, while for very small thicknesses below about 40 nm the film decays into nm-sized spherical droplets. At intermediate film thicknesses percolated networks of small oxide bridges are formed

  17. LET dependency of heavy-ion induced apoptosis in V79 cells

    Aoki, Mizuho; Furusawa, Yoshiya; Yamada, Takeshi

    2000-01-01

    We investigated the relationship between the LET values and cell death, defined as either apoptosis or loss of reproductive integrity (reproductive death), using Chinese hamster V79 cells. The cells were irradiated with X-rays or carbon-ion beams from the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). Apoptosis was defined based on the morphological change upon treating of cells with caffeine. The apoptotic index, the ratio of apoptotic cells to the total, after exposure to 2 Gy of X-rays was 0.043. Upon irradiation with carbon-ion beams, the index was gradually increased with increasing LET values, reaching a maximum of 0.076 at 110 keV/μm, and then decreased to 0.054 at 237 keV/μm. An analogous pattern of the LET dependence was observed between reproductive death and apoptotic death. The cell-survival values obtained after 2 Gy exposure (SF 2 ) were 0.64, 0.13, and 0.24, respectively. A similar trend was found for the RBE values calculated from the initial slope for both apoptosis and reproductive death. These results strongly suggest that the target for both types of cell death is the same. (author)

  18. Transient current induced in thin film diamonds by swift heavy ions

    Sato, Shin-ichiro; Makino, Takahiro; Ohshima, Takeshi; Kamiya, Tomihiro; Kada, Wataru

    2017-01-01

    Single crystal diamond is a suitable material for the next generation particle detectors because of the superior electrical properties and the high radiation tolerance. In order to investigate charge transport properties of diamond particle detectors, transient currents generated in diamonds by single swift heavy ions (26 MeV O 5+ and 45 MeV Si 7+ ) are investigated. We also measured two dimensional maps of transient currents by single ion hits. In the case of 50 μm-thick diamond, both the signal height and the collected charge are reduced by the subsequent ion hits and the charge collection time is extended. Our results are thought to be attributable to the polarization effect in diamond and it appears only when the transient current is dominated by hole current. In the case of 6 μm-thick diamond membrane, an “island” structure is found in the 2D map of transient currents. Signals in the islands shows different applied bias dependence from signals in other regions, indicating different crystal and/or metal contact quality. Simulation study of transient currents based on the Shockley-Ramo theorem clarifies that accumulation of space charges changes distribution of electric field in diamond and causes the polarization effect.

  19. Probing medium-induced jet splitting and energy loss in heavy-ion collisions

    Chang, Ning-Bo; Cao, Shanshan; Qin, Guang-You

    2018-06-01

    The nuclear modification of jet splitting in relativistic heavy-ion collisions at RHIC and the LHC energies is studied based on the higher twist formalism. Assuming coherent energy loss for the two splitted subjets, a non-monotonic jet energy dependence is found for the nuclear modification of jet splitting function: strongest modification at intermediate jet energies whereas weaker modification for larger or smaller jet energies. Combined with the smaller size and lower density of the QGP medium at RHIC than at the LHC, this helps to understand the groomed jet measurements from CMS and STAR Collaborations: strong modification of the momentum sharing zg distribution at the LHC and no obvious modification of zg distribution at RHIC. In addition, the observed nuclear modification pattern of the groomed jet zg distribution cannot be explained solely by independent energy loss of the two subjets. Our result may be tested in future measurements of groomed jets with lower jet energies at the LHC and larger jet energies at RHIC, for different angular separations between the two subjets.

  20. Irradiation effects induced by multiply charged heavy ions on astrophysical materials such as crystals and ices

    Langlinay, Thomas

    2014-01-01

    The solar system and the interstellar medium are permanently exposed to radiations such as solar wind and cosmic rays. The interaction between energetic particles and astrophysical materials (ices, silicates and carbon-based materials) plays an important role in several astrophysical phenomena. Laboratory experiments correlated to observational data may allow a better understanding of these phenomena. The aim of this thesis was to study the effect of slow and fast heavy ions on lithium fluoride and on astrophysical materials such as ices and silicates. We focused on the sputtering phenomenon. The present study was performed with a time of flight imaging technique (XY-TOF-SIMS) at the CIMAP-GANIL laboratory. The major fraction of secondary ions is found to be emitted in the form of clusters. Several parameters affect sputtering: the stopping power regime, the thickness of the target, the incident angle and, for low highly charged ions, the projectile charge. Our laboratory simulations exhibit the possibility that sputtered particles contribute to the formation of Mercury's and Jupiter's moons exosphere. (author)

  1. Heavy-ion targets

    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

  2. Heavy-ion radiography

    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

  3. Phenomenological approaches of dissipative heavy ion collisions

    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

  4. Nuclear fission and reactions

    Anon.

    1975-01-01

    The nuclear fission research programs are designed to elucidate basic features of the fission process. Specifically, (1) factors determining how nucleons of a fissioning nucleus are distributed between two fission fragments, (2) factors determining kinetic energy and excitation energies of fragments, and (3) factors controlling fission lifetimes. To these ends, fission studies are reported for several heavy elements and include investigations of spontaneous and neutron-induced fission, heavy ion reactions, and high energy proton reactions. The status of theoretical research is also discussed. (U.S.)

  5. Kinetics of amorphization induced by swift heavy ions in {alpha}-quartz

    Pena-Rodriguez, O., E-mail: ovidio.pena@uam.es [Centro de Micro-Analisis de Materiales, Universidad Autonoma de Madrid (CMAM-UAM), Cantoblanco, E-28049 Madrid (Spain); Instituto de Optica, Consejo Superior de Investigaciones Cientificas (IO-CSIC), C/Serrano 121, E-28006 Madrid (Spain); Manzano-Santamaria, J. [Centro de Micro-Analisis de Materiales, Universidad Autonoma de Madrid (CMAM-UAM), Cantoblanco, E-28049 Madrid (Spain); Euratom/CIEMAT Fusion Association, Madrid (Spain); Rivera, A. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, C/ Jose Gutierrez Abascal 2, E-28006 Madrid (Spain); Garcia, G. [Laboratory of Synchrotron Light (CELLS-ALBA), 08290 Cerdanyola del Valles, Barcelona (Spain); Olivares, J. [Centro de Micro-Analisis de Materiales, Universidad Autonoma de Madrid (CMAM-UAM), Cantoblanco, E-28049 Madrid (Spain); Instituto de Optica, Consejo Superior de Investigaciones Cientificas (IO-CSIC), C/Serrano 121, E-28006 Madrid (Spain); Agullo-Lopez, F. [Centro de Micro-Analisis de Materiales, Universidad Autonoma de Madrid (CMAM-UAM), Cantoblanco, E-28049 Madrid (Spain); Departamento de Fisica de Materiales, Universidad Autonoma de Madrid (UAM), Cantoblanco, E-28049 Madrid (Spain)

    2012-11-15

    The kinetics of amorphization in crystalline SiO{sub 2} ({alpha}-quartz) under irradiation with swift heavy ions (O{sup +1} at 4 MeV, O{sup +4} at 13 MeV, F{sup +2} at 5 MeV, F{sup +4} at 15 MeV, Cl{sup +3} at 10 MeV, Cl{sup +4} at 20 MeV, Br{sup +5} at 15 and 25 MeV and Br{sup +8} at 40 MeV) has been analyzed in this work with an Avrami-type law and also with a recently developed cumulative approach (track-overlap model). This latter model assumes a track morphology consisting of an amorphous core (area {sigma}) and a surrounding defective halo (area h), both being axially symmetric. The parameters of the two approaches which provide the best fit to the experimental data have been obtained as a function of the electronic stopping power S{sub e}. The extrapolation of the {sigma}(S{sub e}) dependence yields a threshold value for amorphization, S{sub th} Almost-Equal-To 2.1 keV/nm; a second threshold is also observed around 4.1 keV/nm. We believe that this double-threshold effect could be related to the appearance of discontinuous tracks in the region between 2.1 and 4.1 keV/nm. For stopping power values around or below the lower threshold, where the ratio h/{sigma} is large, the track-overlap model provides a much better fit than the Avrami function. Therefore, the data show that a right modeling of the amorphization kinetics needs to take into account the contribution of the defective track halo. Finally, a short comparative discussion with the kinetic laws obtained for elastic collision damage is given.

  6. Swift heavy ion induced modification in morphological and physico-chemical properties of tin oxide nanocomposites

    Jaiswal, Manoj Kumar [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India)

    2013-11-15

    Nanocomposite thin films of tin oxide (SnO{sub 2})/titanium oxide (TiO{sub 2}) were grown on silicon (1 0 0) substrates by electron beam evaporation deposition technique using sintered nanocomposite pellet of SnO{sub 2}/TiO{sub 2} in the percentage ratio of 95:5. Sintering of the nanocomposite pellet was done at 1300 °C for 24 h. The thicknesses of these films were measured to be 100 nm during deposition using piezo-sensor attached to the deposition chamber. TiO{sub 2} doped SnO{sub 2} nanocomposite films were irradiated by 100 MeV Au{sup 8+} ion beam at fluence range varying from 1 × 10{sup 11} ions/cm{sup 2} to 5 × 10{sup 13} ions/cm{sup 2} at Inter University Accelerator Center (IUAC), New Delhi, India. Chemical properties of pristine and ion irradiation modified thin films were characterized by Fourier Transform Infrared (FTIR) spectroscopy. FTIR peak at 610 cm{sup −1} confirms the presence of O–Sn–O bridge of tin (IV) oxide signifying the composite nature of pristine and irradiated thin films. Atomic Force Microscope (AFM) in tapping mode was used to study the surface morphology and grain growth due to swift heavy ion irradiation at different fluencies. Grain size calculations obtained from sectional analysis of AFM images were compared with results obtained from Glancing Angle X-ray Diffraction (GAXRD) measurements using Scherrer’s formulae. Phase transformation due to irradiation was observed from Glancing Angle X-ray Diffraction (GAXRD) results. The prominent 2θ peaks observed in GAXRD spectrum are at 30.67°, 32.08°, 43.91°, 44.91° and 52.35° in the irradiated films.

  7. Heavy ion fusion

    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. Discrimination and competition between complete fusion and deep inelastic reactions induced by heavy ions

    Hanappe, F.; Tamain, B.

    1977-01-01

    One tries to find a way to discriminate between fission following fusion and deep inelastic processes with large mass transfer. Fragment analysis (kinetic energy, mass, charge distributions) gives generally no answer. The deexcitation properties of the fragments (gamma ray, charged particles and neutron emission) are difficult to interpret, and only recent results concerning neutron emission show different patterns for both processes. The reasons for which a system evolves towards deep inelastic processes rather than fusion are discussed

  9. Heavy-ion induced desorption yields of amorphous carbon films bombarded with 4.2 MeV/u lead ions

    Mahner, E; Küchler, D; Scrivens, R; Costa Pinto, P; Yin Vallgren, C; Bender, M

    2011-01-01

    During the past decade, intense experimental studies on the heavy-ion induced molecular desorption were performed in several particle accelerator laboratories worldwide in order to understand and overcome large dynamic pressure rises caused by lost beam ions. Different target materials and various coatings were studied for desorption and mitigation techniques were applied to heavy-ion accelerators. For the upgrade of the CERN injector complex, a coating of the Super Proton Synchrotron (SPS) vacuum system with a thin film of amorphous carbon is under study to mitigate the electron cloud effect observed during SPS operation with the nominal proton beam for the Large Hadron Collider (LHC). Since the SPS is also part of the heavy-ion injector chain for LHC, dynamic vacuum studies of amorphous carbon films are important to determine their ion induced desorption yields. At the CERN Heavy Ion Accelerator (LINAC 3), carbon-coated accelerator-type stainless steel vacuum chambers were tested for desorption using 4.2 Me...

  10. Macroscopic model description of heavy-ion induced complex-fragment emission

    Carjan, N.

    1988-01-01

    The Yukawa-plus-exponential finite-range model and the standard liquid-drop model are shortly reviewed and compared. The dependence of the barrier heights and of the saddle-point shapes on mass-asymmetry and on angular momentum is studied for the compound nuclei 110 Sn, 149 Tb and 194 Hg. The predicted asymmetric-fission barriers, charge yields and total kinetic energies are compared with experimental data obtained from the deexcitation of compound nuclei by complex-fragment emission

  11. Structure of heavy-ion tracks in zircon

    Braunshausen, G.; Bursill, L.A.; Vetter, J.; Spohr, R.

    1990-01-01

    Gem quality zirconas (ZrSiO 4 ) were irradiated with 14MeV/u Pb ions. Observations of heavy-ion tracks confirmed that fission or heavy-ion irradiation damage is confined to a 50-100 Aangstroem core region, which has undergone a crystalline-glass phase transition. 3 refs., 3 figs

  12. Research in heavy-ion nuclear physics

    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

  13. Heavy-ion dosimetry

    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

  14. Heavy ion physics

    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

  15. Effects of electronic and nuclear stopping power on disorder induced in GaN under swift heavy ion irradiation

    Moisy, F., E-mail: moisy@ganil.fr [CIMAP, Normandie Universite ENSICAEN/CEA/CNRS, 6 Bd Maréchal Juin, 14050 Caen (France); Sall, M.; Grygiel, C.; Balanzat, E.; Boisserie, M.; Lacroix, B. [CIMAP, Normandie Universite ENSICAEN/CEA/CNRS, 6 Bd Maréchal Juin, 14050 Caen (France); Simon, P. [CNRS, UPR 3079 CEMHTI, CS 90055, 45071 Orléans Cedex 2 (France); Monnet, I. [CIMAP, Normandie Universite ENSICAEN/CEA/CNRS, 6 Bd Maréchal Juin, 14050 Caen (France)

    2016-08-15

    Wurtzite GaN epilayers, grown on the c-plane of sapphire substrate, have been irradiated with swift heavy ions at different energies and fluences, and thereafter studied by Raman scattering spectroscopy, UV–visible spectroscopy and transmission electron microscopy. Raman spectra show strong structural modifications in the GaN layer. Indeed, in addition to the broadening of the allowed modes, a large continuum and three new modes at approximately 200 cm{sup −1}, 300 cm{sup −1} and 670 cm{sup −1} appear after irradiation attributed to disorder-activated Raman scattering. In this case, spectra are driven by the phonon density of states of the material due to the loss of translation symmetry of the lattice induced by defects. It was shown qualitatively that both electronic excitations and elastic collisions play an important role in the disorder induced by irradiation. UV–visible spectra reveal an absorption band at 2.8 eV which is linked to the new mode at 300 cm{sup −1} observed in irradiated Raman spectra and comes from Ga-vacancies. These color centers are produced by elastic collisions (without any visible effect of electronic excitations).

  16. Nuclear fission and neutron-induced fission cross-sections

    James, G.D.; Lynn, J.E.; Michaudon, A.; Rowlands, J.; de Saussure, G.

    1981-01-01

    A general presentation of current knowledge of the fission process is given with emphasis on the low energy fission of actinide nuclei and neutron induced fission. The need for and the required accuracy of fission cross section data in nuclear energy programs are discussed. A summary is given of the steps involved in fission cross section measurement and the range of available techniques. Methods of fission detection are described with emphasis on energy dependent changed and detector efficiency. Examples of cross section measurements are given and data reduction is discussed. The calculation of fission cross sections is discussed and relevant nuclear theory including the formation and decay of compound nuclei and energy level density is introduced. A description of a practical computation of fission cross sections is given.

  17. Heavy ion accelerators

    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.)

  18. Damage induced by swift heavy ions in a pure metallic target: iron. Experimental results and numerical simulation

    Legrand, P.

    1993-01-01

    The damage induced when a high energy deposition occurs in the electronic system of a pure metal (Ag, Co, Fe, Ni, Pd, Pt, Ti, W, Zr) has been investigated using two methods: low temperature swift heavy ion (O, Ar, Kr, Xe, Pb, u) irradiations and computer simulations by molecular dynamics. Irradiations reveal that up to now, it is only in iron, titanium, cobalt and zirconium targets that high levels of energy deposition in electronic excitations lead to a new mechanism of defect creation in addition to the effects of elastic collisions. This mechanism might be the Coulomb explosion: the incident ion creates in its wake a cylinder of highly ionized matter; Coulomb repulsions of short duration in metallic targets could then set a great number of neighbouring atoms into motion and lead to permanent atomic displacements. Using molecular dynamics, we confirm that atomic displacements can indeed occur when neighbouring perturbated atoms receive even a very small amount of kinetic energy (≤ 1 eV). This happens only if the repulsive movements are collective and coherent. Defect creation and annealing of preexisting defects which occur in iron at different energy deposition levels are successfully simulated. An original empirical N-body potential, allowing a realistic description of the bulk properties of the body centered cubic iron, is used. (author). refs., figs., tabs

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

    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)

  20. Adaptive response of low linear energy transfer X-rays for protection against high linear energy transfer accelerated heavy ion-induced teratogenesis.

    Wang, Bing; Ninomiya, Yasuharu; Tanaka, Kaoru; Maruyama, Kouichi; Varès, Guillaume; Eguchi-Kasai, Kiyomi; Nenoi, Mitsuru

    2012-12-01

    Adaptive response (AR) of low linear energy transfer (LET) irradiations for protection against teratogenesis induced by high LET irradiations is not well documented. In this study, induction of AR by X-rays against teratogenesis induced by accelerated heavy ions was examined in fetal mice. Irradiations of pregnant C57BL/6J mice were performed by delivering a priming low dose from X-rays at 0.05 or 0.30 Gy on gestation day 11 followed one day later by a challenge high dose from either X-rays or accelerated heavy ions. Monoenergetic beams of carbon, neon, silicon, and iron with the LET values of about 15, 30, 55, and 200 keV/μm, respectively, were examined. Significant suppression of teratogenic effects (fetal death, malformation of live fetuses, or low body weight) was used as the endpoint for judgment of a successful AR induction. Existence of AR induced by low-LET X-rays against teratogenic effect induced by high-LET accelerated heavy ions was demonstrated. The priming low dose of X-rays significantly reduced the occurrence of prenatal fetal death, malformation, and/or low body weight induced by the challenge high dose from either X-rays or accelerated heavy ions of carbon, neon or silicon but not iron particles. Successful AR induction appears to be a radiation quality event, depending on the LET value and/or the particle species of the challenge irradiations. These findings would provide a new insight into the study on radiation-induced AR in utero. © 2012 Wiley Periodicals, Inc.

  1. Structural changes of DNA in heavy ion-induced mutants on Arabidopsis

    Tano, S.; Shikazono, N.; Tanaka, A.; Yokota, Y.; Watanabe, H.

    1997-01-01

    In order to investigate the frequency of structural changes induced by high LET radiation in plants, a comparison was made between DNA fragments amplified by the polymerase chain reaction (PCR) from C ion- and electron-induced Arabidopsis mutants at GL and TT loci. (orig./MG)

  2. Structural changes of DNA in heavy ion-induced mutants on Arabidopsis

    Tano, S; Shikazono, N; Tanaka, A; Yokota, Y; Watanabe, H [Japan Atomic Research Research Inst., Watanuki, Takasaki (Japan). Advanced Science Research Center

    1997-09-01

    In order to investigate the frequency of structural changes induced by high LET radiation in plants, a comparison was made between DNA fragments amplified by the polymerase chain reaction (PCR) from C ion- and electron-induced Arabidopsis mutants at GL and TT loci. (orig./MG)

  3. Mixing induced by swift heavy ion irradiation at Fe/Si interface

    Unknown

    Experimental results show that high electronic excitation can also induce structural modifications in metallic sys- tems similar to those in non-metallic systems. This means that all Se-dependent effects induced in different materials are probably related to some basic energy transfer mecha- nism between the incident ion and ...

  4. Respectives of heavy ion physics in JINR

    Flerov, G.N.

    1983-01-01

    Perspectives of heavy ion physics in JINR are discussed. The main attention is paid to directions that are connected with the application of intensive beams of U-400 cyclotron. Experiments into studying stability limits of heavy atomic nuclei are considered. The possibility of using beams of heavy ions in applied fields, particularly for the production of very thin nuclear filters is noted. Prospects of synthesis of superheavy elements (SHE) and SHE search in nature are also considered. The data on the events of spontaneous fission found in meteorite and hydrotherms and the data on lengths of tracks in olivines from meteorite prove the possibility of obtaining evidences of SHE existence in nature

  5. Swift heavy ion irradiation induced phase transformation in undoped and niobium doped titanium dioxide composite thin films

    Gautam, Subodh K., E-mail: subodhkgtm@gmail.com [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Chettah, Abdelhak [LGMM Laboratory, Université 20 Août 1955-Skikda, BP 26, 21000 Skikda (Algeria); Singh, R.G. [Department of Physics, Bhagini Nivedita College, Delhi University, Delhi 110043 (India); Ojha, Sunil; Singh, Fouran [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

    2016-07-15

    Study reports the effect of swift heavy ion (SHI) irradiation induced phase transformation in undoped and Niobium doped anatase TiO{sub 2} composite thin films. Investigations were carried out at different densities of electronic excitations (EEs) using 120 MeV Ag and 130 MeV Ni ions irradiations. Films were initially annealed at 900 °C and results revealed that undoped films were highly stable in anatase phase, while the Nb doped films showed the composite nature with the weak presence of Niobium penta-oxide (Nb{sub 2}O{sub 5}) phase. The effect at low density of EEs in undoped film show partial anatase to rutile phase transformation; however doped film shows only further growth of Nb{sub 2}O{sub 5} phase beside the anatase to rutile phase transformation. At higher density of EEs induced by Ag ions, registered continuous ion track of ∼3 nm in lattice which leads to nano-crystallization followed by decomposition/amorphization of rutile TiO{sub 2} and Nb{sub 2}O{sub 5} phases in undoped and doped films, respectively. However, Ni ions are only induced discontinuous sequence of ion tracks with creation of damage and disorder and do not show amorphization in the lattice. The in-elastic thermal spike calculations were carried out for anatase TiO{sub 2} phase to understand the effect of EEs on anatase to rutile phase transformation followed by amorphization in NTO films in terms of continuous and discontinuous track formation by SHI irradiation.

  6. Heavy ion induced damage in MgAl sub 2 O sub 4 , an inert matrix candidate for the transmutation of minor actinides

    Wiss, T

    1999-01-01

    Magnesium aluminum spinel (MgAl sub 2 O sub 4) is a material selected as a possible matrix for transmutation of minor actinides by neutron capture or fission in nuclear reactors. To study the radiation stability of this inert matrix, especially against fission product impact, irradiations with heavy energetic ions or clusters have been performed. The high electronic energy losses of the heavy ions in this material led to the formation of visible tracks as evidenced by transmission electron microscopy for 30 MeV C sub 6 sub 0 -Buckminster fullerenes and for ions of energy close to or higher than fission energy ( sup 2 sup 0 sup 9 Bi with 120 MeV and 2.38 GeV energy). The irradiations at high energies showed a pronounced degradation of the spinel. Additionally, MgAl sub 2 O sub 4 exhibited a large swelling for irradiation at high fluences with fission products of fission energy (here I-ions of 72 MeV) and at temperatures <= 500 deg. C. These observations are discussed from the technological point of view in ...

  7. Heavy ion induced damage to plasmid DNA : plateau region vs. spread out Bragg-peak

    Dang, H.M.; van Goethem, M.J.; van der Graaf, E.R.; Brandenburg, S.; Hoekstra, R.A.; Schlathölter, T.A.

    We have investigated the damage of synthetic plasmid pBR322 DNA in dilute aqueous solutions induced by fast carbon ions. The relative contribution of indirect damage and direct damage to the DNA itself is expected to vary with linear energy transfer along the ion track, with the direct damage

  8. Screening and identification of respiration deficiency mutants of yeasts (Saccharomyces Cerevisiae) induced by heavy ion irradiation

    Mao Shuhong; Chinese Academy of Sciences, Beijing; Jin Genming; Wei Zengquan; Xie Hongmei; Zhang Hong

    2006-01-01

    A screen of respiration deficiency mutants of Saccharomyces Cerevisiae induced by 5.19 MeV/u 22 Ne 5- ion irradiation is studied. Some respiration deficiency mutants, which are white colony phenotype in the selective culture of TTC medium, are obtained. The mutants are effectively identified by means of a new and simplified restriction analysis method. (authors)

  9. Mutation induction by heavy ions

    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.

  10. Equivalence of displacement radiation damage in superluminescent diodes induced by protons and heavy ions

    Li, Xingji, E-mail: lxj0218@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Liu, Chaoming [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Lan, Mujie; Xiao, Liyi [Center of Micro-electronics, Harbin Institute of Technology, Harbin 150001 (China); Liu, Jianchun; Ding, Dongfa [Beijing Aerospace Times Optical-electronic Technology Co.Ltd, Beijing 100854 (China); Yang, Dezhuang; He, Shiyu [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2013-07-11

    The degradation of optical power for superluminescent diodes is in situ measured under exposures of protons with various energies (170 keV, 3 MeV and 5 MeV), and 25 MeV carbon ions for several irradiation fluences. Experimental results show that the optical power of the SLDs decreases with increasing fluence. The protons with lower energies cause more degradation in the optical power of SLDs than those with higher energies at a given fluence. Compared to the proton irradiation with various energies, the 25 MeV carbon ions induce more severe degradation to the optical power. To characterize the radiation damage of the SLDs, the displacement doses as a function of chip depth in the SLDs are calculated by SRIM code for the protons and carbon ions. Based on the irradiation testing and calculation results, an approach is given to normalize the equivalence of displacement damage induced by various charged particles in SLDs.

  11. Chemical modifications of polymer films induced by high energy heavy ions

    Zhu Zhiyong; Sun Youmei; Liu Changlong; Liu Jie; Jin Yunfan

    2002-01-01

    Polymer films including polyethylene terephthalate (PET), polystyrene (PS) and polycarbonate (PC) were irradiated at room temperature with ions of 35 MeV/u 40 Ar, 25 MeV/u 84 Kr, 15.1 MeV/u 136 Xe and 11.4 MeV/u 238 U to fluences ranging from 9x10 9 to 5.5x10 12 ions/cm 2 . The radiation-induced chemical changes of the materials were investigated by Fourier-transform infrared (FTIR) and ultraviolet/visible spectroscopies. It is found that the absorbance in the ultraviolet and visible range induced by all irradiations follows a linear relationship with fluence. The radiation-induced absorbance normalized to one particle increases slowly with increasing of electronic energy loss below about 8 keV/nm followed by a sharp increase up to about 15 keV/nm above which saturation is reached. FTIR measurements reveal that the materials suffer serious degradation through bond breaking. The absorbance of the typical infrared bands decays exponentially with increase of ion fluence and the bond-disruption cross-section shows a sigmoid variation with electronic energy loss. In PET loss of crystallinity is attributed to the configuration transformation of the ethylene glycol residue from trans into the gauche. Alkyne end groups are induced in all the materials above certain electronic energy loss threshold, which is found to be about 0.8 keV/nm for PS and 0.4 keV/nm for PC. The production cross-section of alkyne end group increases with increasing of electronic energy loss and shows saturation at high electronic energy loss values. It is concluded that not only the physical processes but also the chemical processes of the energy deposition determine the modification of polymer

  12. Heavy Ion Induced Degradation in SiC Schottky Diodes: Bias and Energy Deposition Dependence

    Javanainen, Arto; Galloway, Kenneth F.; Nicklaw, Christopher; Bosser, Alexandre L.; Ferlet-Cavrois, Veronique; Lauenstein, Jean-Marie; Pintacuda, Francesco; Reed, Robert A.; Schrimpf, Ronald D.; Weller, Robert A.; hide

    2016-01-01

    Experimental results on ion-induced leakage current increase in 4H-SiC Schottky power diodes are presented. Monte Carlo and TCAD simulations show that degradation is due to the synergy between applied bias and ion energy deposition. This degradation is possibly related to thermal spot annealing at the metal semiconductor interface. This thermal annealing leads to an inhomogeneity of the Schottky barrier that could be responsible for the increase leakage current as a function of fluence.

  13. Mass spectrometric comparison of swift heavy ion-induced and anaerobic thermal degradation of polymers

    Lima, V.; Hossain, U. H.; Walbert, T.; Seidl, T.; Ensinger, W.

    2018-03-01

    The study of polymers irradiated by highly energetic ions and the resulting radiation-induced degradation is of major importance for space and particle accelerator applications. The mechanism of ion-induced molecular fragmentation of polyethylene, polyethyleneimine and polyamide was investigated by means of mass spectrometry and infrared spectroscopy. The results show that the introduction of nitrogen and oxygen into the polymer influences the stability rendering aliphatic polymers with heteroatoms less stable. A comparison to thermal decomposition data from literature reveals that ion-induced degradation is different in its bond fracture mechanism. While thermal degradation starts at the weakest bond, which is usually the carbon-heteroatom bond, energetic ion irradiation leads in the first step to scission of all types of bonds creating smaller molecular fragments. This is due to the localized extreme energy input under non-equilibrium conditions when the ions transfer kinetic energy onto electrons. These findings are of relevance for the choice of polymers for long-term application in both space and accelerator facilities.

  14. Viscous surface flow induced on Ti-based bulk metallic glass by heavy ion irradiation

    Zhang, Kun [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Hu, Zheng [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Science and Technology on Vehicle Transmission Laboratory, China North Vehicle Research Institute, Beijing 100072 (China); Li, Fengjiang [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Wei, Bingchen, E-mail: weibc@imech.ac.cn [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

    2016-12-30

    Highlights: • Obvious smoothing and roughening phases on the Ti-based MG surface resulted, which correspond respectively to the normal and off-normal incidence angles. • Atomic force microscopy confirms two types of periodic ripples distributed evenly over the rough surface. • The irradiation-induced viscosity of MG is about 4×10{sup 12} Pa·s, which accords with the theoretical prediction for metallic glasses close to glass transition temperature. • Surface-confined viscous flow plays a dominant quantitative role, which is due to radiation-induced softening of the low-viscosity surface layer. - Abstract: Ti-based bulk metallic glass was irradiated by a 20 MeV Cl{sup 4+} ion beam under liquid-nitrogen cooling, which produced remarkable surface smoothing and roughening that respectively correspond to normal and off-normal incidence angles of irradiation. Atomic force microscopy confirms two types of periodic ripples distributed evenly over the rough glass surface. In terms of mechanism, irradiation-induced viscosity agrees with the theoretical prediction for metallic glasses near glass transition temperature. Here, a model is introduced, based on relaxation of confined viscous flow with a thin liquid-like layer, that explains both surface smoothing and ripple formation. This study demonstrates that bulk metallic glass has high morphological instability and low viscosity under ion irradiation, which assets can pave new paths for metallic glass applications.

  15. Radiation induced muscositis as space flight risk. Model studies on X-ray and heavy ion irradiated typical oral mucosa models

    Tschachojan, Viktoria

    2014-01-01

    Humans in exomagnetospheric space are exposed to highly energetic heavy ion radiation which can be hardly shielded. Since radiation-induced mucositis constitutes a severe complication of heavy ion radiotherapy, it would also implicate a serious medical safety risk for the crew members during prolonged space flights such as missions to Moon or Mars. For assessment of risk developing radiation-induced mucositis, three-dimensional organotypic cultures of immortalized human keratinocytes and fibroblasts were irradiated with a 12 C particle beam at high energies or X-Rays. Immunofluorescence stainings were done from cryosections and radiation induced release of cytokines and chemokines was quantified by ELISA from culture supernatants. The major focuses of this study were on 4, 8, 24 and 48 hours after irradiation. The conducted analyses of our mucosa model showed many structural similarities with the native oral mucosa and authentic immunological responses to radiation exposure. Quantification of the DNA damage in irradiated mucosa models revealed about twice as many DSB after heavy-ion irradiation compared to X-rays at definite doses and time points, suggesting a higher gene toxicity of heavy ions. Nuclear factor κB activation was observed after treatment with X-rays or 12 C particles. An activation of NF κB p65 in irradiated samples could not be detected. ELISA analyses showed significantly higher interleukin 6 and interleukin 8 levels after irradiation with X-rays and 12 C particles compared to non-irradiated controls. However, only X-rays induced significantly higher levels of interleukin 1β. Analyses of TNF-α and IFN-γ showed no radiation-induced effects. Further analyses revealed a radiation-induced reduction in proliferation and loss of compactness in irradiated oral mucosa model, which would lead to local lesions in vivo. In this study we revealed that several pro-inflammatory markers and structural changes are induced by X-rays and heavy-ion irradiation

  16. Cellular radiobiology of heavy-ion beams

    Tobias, C.A.; Blakely, E.A.; Ngo, F.Q.H.; Roots, R.J.; Yang, T.C.

    1981-01-01

    Progress is reported in the following areas of this research program: relative biological effectiveness and oxygen enhancement ratio of silicon ion beams; heavy ion effects on the cell cycle; the potentiation effect (2 doses of high LET heavy-ion radiations separated by 2 to 3 hours); potentially lethal damage in actively growing cells and plateau growth cells; radiation induced macromolecular lesions and cellular radiation chemistry; lethal effects of dual radiation; and the development of a biophysical repair/misrepair model

  17. Analysis of mutations in the human HPRT gene induced by accelerated heavy-ion irradiation

    Kagawa, Yasuhiro; Yatagai, Fumio; Hanaoka, Fumio; Suzuki, Masao; Kase, Youko; Kobayashi, Akiko; Hirano, Masahiko; Kato, Takesi; Watanabe, Masami.

    1995-01-01

    Multiplex PCR analysis of HPRT(-) mutations in human embryo (HE) cells induced by 230 keV/μm carbon-ion irradiation showed no large deletion around the exon regions of the locus gene in contrast to the irradiations at different LETs. To identify these mutations, the sequence alterations in a cDNA of hprt gene were determined for 18 mutant clones in this study. Missing of exon 6 was the most frequent mutational event (10 clones), and missing of both exons 6 and 8 was next most frequent event (6 clones), then base substitutions (2 clones). These characteristics were not seen in a similar analysis of spontaneous mutations, which showed base substitution (5 clones), frameshift (2 clones), missing of both exons 2 and 3 (2 clones), and a single unidentified clone. Direct sequencing and restriction enzyme digestion of the genomic DNA of the mutants which showed missing of exons 6 and 8 in the cDNA, supports the possibility that they were induced by aberrant mRNA splicing. (author)

  18. Detection of heavy ion induced DNA double-strand breaks using static-field gel electrophoresis

    Taucher-Scholz, G.; Heilmann, J.; Schneider, G.; Kraft, G.

    1994-11-01

    Radiation induced DNA double-strand breaks (DSBs) were measured in Chinese hamster ovary cells (CHO-K1) using an experimental protocol involving static-field gel electrophoresis following exposure to various accelerated ions. Dose-effect curves were set up and relative biological efficiencies (RBEs) for DSB induction were determined for different radiation qualities. RBEs around 1 were obtained for low energy deuterons (6-7 keV/μm), while for high energy oxygen ions (20 keV/μm) an RBE value slightly greater than 1 was determined. Low energetic oxygen ions (LET ∼ 250 keV/μm) were found to show RBEs substantially below unity, and for higher LET particles (≥ 250 keV/μm) RBEs for DSB induction were generally found to be smaller than 1. The data presented here are in line with the generally accepted view that not induced DSBs, but misrepaired or unrepaired DNA-lesions are related to cellular inactivation. (orig.)

  19. Taking into account the Coulomb effects in the four-body model in reactions of simultaneous two-neutron transfer induced by heavy ions

    Kayumov, S.S.; Mukhamedzhanov, A.M.; Yarmukhamedov, R.

    1988-01-01

    In the four-body model for partial amplitudes of two-neutron transfer induced by heavy ions we derive in the approximation of the mechanism of simultaneous transfer the expression for the senior term for l→∞ taking into account the Coulomb effects. The senior singular term of the amplitude at z = zeta is singled out explicitly (z = cos θ, θ is the scattering angle in the c.m.s. and zeta is the singularity closest to the physical region which corresponds to the mechanism of simultaneous transfer). We calculate differential cross sections for the transfer of two neutrons between heavy ions and estimate the accuracy of taking into account the Coulomb effects in the traditional method of distorted waves

  20. Influence of solutes on heavy ion induced void-swelling in binary copper alloys

    Leister, K.H.

    1983-05-01

    As radiation induced swelling of metals depends on their constitution, swelling of copper and copper alloys with low solute concentration is studied. Diffusion coefficients and solubility of solute in copper were used as criteria of selection of the alloys. The samples were irradiated by 200keV copper ions. Swelling and void densities were measured by transmission electron microscopy. The measurements show low dependence of swelling upon the diffusibility of the solute in the solvent and a strong dependence on their concentration. Alloys of 0.1at% solute show more swelling than pure copper, and alloys of 1at% show less swelling under the irradiation conditions. The different swelling behavior in Cu-Ni alloys is due to the different void densities. (orig.) [de

  1. Heavy ion irradiation induced effects in Ni3N/Al bilayers

    Dhar, S.; Rissanen, L.; Engel, K.; Wenderoth, M.; Lieb, K.P.

    2001-01-01

    The article reports on the Xe ion beam irradiation studies of Ni 3 N/Al bilayers at 80 K. The ion-induced modifications were monitored by Rutherford backscattering (RBS), resonant nuclear reaction analysis (RNRA), X-ray diffraction (XRD) and atomic force microscopy (AFM). We found preferential loss of nitrogen from the surface region of the Ni 3 N top layers. The surface roughness Δσ S and the interface broadening variance Δσ int 2 increase linearly with the Xe ion fluence PHI. The experimental mixing rate of Δσ 2 /PHI=1.8 nm 4 is explained by considering an enhancement of ballistic mixing due to chemical reactions at the interface

  2. Swift heavy ion-beam induced amorphization and recrystallization of yttrium iron garnet

    Costantini, Jean-Marc; Miro, Sandrine; Beuneu, François; Toulemonde, Marcel

    2015-01-01

    Pure and (Ca and Si)-substituted yttrium iron garnet (Y 3 Fe 5 O 12 or YIG) epitaxial layers and amorphous films on gadolinium gallium garnet (Gd 3 Ga 5 O 12 , or GGG) single crystal substrates were irradiated by 50 MeV 32 Si and 50 MeV (or 60 MeV) 63 Cu ions for electronic stopping powers larger than the threshold value (∼4 MeV μm −1 ) for amorphous track formation in YIG crystals. Conductivity data of crystalline samples in a broad ion fluence range (10 11 –10 16 cm −2 ) are modeled with a set of rate equations corresponding to the amorphization and recrystallization induced in ion tracks by electronic excitations. The data for amorphous layers confirm that a recrystallization process takes place above ∼10 14 cm −2 . Cross sections for both processes deduced from this analysis are discussed in comparison to previous determinations with reference to the inelastic thermal-spike model of track formation. Micro-Raman spectroscopy was also used to follow the related structural modifications. Raman spectra show the progressive vanishing and randomization of crystal phonon modes in relation to the ion-induced damage. For crystalline samples irradiated at high fluences (⩾10 14 cm −2 ), only two prominent broad bands remain like for amorphous films, thereby reflecting the phonon density of states of the disordered solid, regardless of samples and irradiation conditions. The main band peaked at ∼660 cm −1 is assigned to vibration modes of randomized bonds in tetrahedral (FeO 4 ) units. (paper)

  3. A new setup for the investigation of swift heavy ion induced particle emission and surface modifications

    Meinerzhagen, F.; Breuer, L.; Bukowska, H.; Herder, M.; Schleberger, M.; Wucher, A. [Fakultät für Physik, Universität Duisburg-Essen and Cenide, 47057 Duisburg (Germany); Bender, M.; Severin, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Lebius, H. [CIMAP (CEA-CNRS-ENSICAEN-UCN), 14070 Caen Cedex 5 (France)

    2016-01-15

    The irradiation with fast ions with kinetic energies of >10 MeV leads to the deposition of a high amount of energy along their trajectory (up to several ten keV/nm). The energy is mainly transferred to the electronic subsystem and induces different secondary processes of excitations, which result in significant material modifications. A new setup to study these ion induced effects on surfaces will be described in this paper. The setup combines a variable irradiation chamber with different techniques of surface characterizations like scanning probe microscopy, time-of-flight secondary ion, and neutral mass spectrometry, as well as low energy electron diffraction under ultra high vacuum conditions, and is mounted at a beamline of the universal linear accelerator (UNILAC) of the GSI facility in Darmstadt, Germany. Here, samples can be irradiated with high-energy ions with a total kinetic energy up to several GeVs under different angles of incidence. Our setup enables the preparation and in situ analysis of different types of sample systems ranging from metals to insulators. Time-of-flight secondary ion mass spectrometry enables us to study the chemical composition of the surface, while scanning probe microscopy allows a detailed view into the local electrical and morphological conditions of the sample surface down to atomic scales. With the new setup, particle emission during irradiation as well as persistent modifications of the surface after irradiation can thus be studied. We present first data obtained with the new setup, including a novel measuring protocol for time-of-flight mass spectrometry with the GSI UNILAC accelerator.

  4. Dosimetry measurements using Timepix in mixed radiation fields induced by heavy ions; comparison with standard dosimetry methods

    Ploc, Ondřej; Kubančák, Ján; Sihver, L.; Uchihori, Y.; Jakoubek, J.; Ambrožová, Iva; Molokanov, A. G.; Pinsky, L.

    2014-01-01

    Roč. 55, S1 (2014), i141-i142 ISSN 0449-3060 R&D Projects: GA MŠk(CZ) LG13031; GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : LET spectrometry * heavy ions * mixed radiation field * pixel detector Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.797, year: 2014

  5. Heavy-ion-induced luminescence of amorphous SiO2 during nanoparticle formation

    Bandourko, Vassili; Umeda, Naoki; Plaksin, Oleg; Kishimoto, Naoki

    2005-01-01

    Silica glass was implanted with negative 60 keV Cu ions at an ion flux from 5 to 75 μA/cm 2 up to a fluence of 1 x 10 17 ions/cm 2 at initial sample temperatures of 300, 573 and 773 K. Spectra of ion-induced photon emission (IIPE) were collected in situ in the range from 250 to 850 nm. Optical absorption spectra of implanted specimens were ex situ measured in the range from 190 to 2500 nm. IIPE spectra showed a broad band centered around 560 nm (2.2 eV) that was assigned to Cu + solutes. The band appeared at the onset of irradiation, increased in intensity up to a fluence of about 5 x 10 15 ions/cm 2 and then gradually decreased indicating three stage of the ion beam synthesis of nanoclusters: accumulation of implants, nucleation and growth nanoclusters. The IIPE intensity normalized on the ion flux is independent on the ion flux below 20 μA/cm 2 at higher fluences. The intensity of the band increased with increasing samples temperature, when optical absorption spectra reveal the increase of Cu nanoparticles size

  6. Swift heavy ion induced phase transformation and thermoluminescence properties of zirconium oxide

    Lokesha, H.S. [Physics R & D Centre, PES Institute of Technology, BSK 3rd Stage, Bangalore 560085 (India); Nagabhushana, K.R., E-mail: bhushankr@gmail.com [Physics R & D Centre, PES Institute of Technology, BSK 3rd Stage, Bangalore 560085 (India); Department of Physics, PES University, BSK 3rd Stage, Bangalore 560085 (India); Singh, Fouran [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

    2016-07-15

    Zirconium oxide (ZrO{sub 2}) powder is synthesized by combustion technique. XRD pattern of ZrO{sub 2} shows monoclinic phase with average crystallite size 35 nm. Pellets of ZrO{sub 2} are irradiated with 100 MeV swift Si{sup 7+}, Ni{sup 7+} and 120 MeV swift Ag{sup 9+} ions in the fluence range 3 × 10{sup 10}–3 × 10{sup 13} ions cm{sup −2}. XRD pattern show the main diffraction peak correspond to monoclinic and tetragonal phase of ZrO{sub 2} in 2θ range 27–33°. Structural phase transformation is observed for Ni{sup 7+} and Ag{sup 9+} ion irradiated samples at a fluence 1 × 10{sup 13} ions cm{sup −2} and 3 × 10{sup 12} ions cm{sup −2} respectively, since the deposited electronic energy loss exceeds an effective threshold (>12 keV nm{sup −1}). Phase transition induced by Ag{sup 9+} ion is nearly 2.9 times faster than Ni{sup 7+} ion at 1 × 10{sup 13} ions cm{sup −2}. Ag{sup 9+} ion irradiation leads two ion impact processes. Thermoluminescence (TL) glow curves exhibit two glows, a well resolved peak at ∼424 K and unresolved peak at 550 K for all SHI irradiated samples. TL response is decreased with increase of ion fluence. Beyond 3 × 10{sup 12} ions cm{sup −2}, samples don’t exhibit TL due to annihilation of defects.

  7. Swift heavy ion induced single event upsets in high density UV-EPROM's

    Dahiwale, S.S. [Department of Physics, University of Pune, Pune 7 (India); Shinde, N.S. [Department of Chemical Engineering, Mie University (Japan); Kanjilal, D. [Inter University Accelerator Center, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 7 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 7 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-04-15

    A few high density UV-EPROM's (32Kb x 8) were irradiated with 5.41 MeV energy {alpha}-particles with fluences from 10{sup 4} to 10{sup 8} alphas/cm{sup 2} and 100 MeV nickel, iodine and silver ions for low fluences between 5 x 10{sup 7} and 10{sup 8} ions/cm{sup 2}. The energy and ion species was selected on the basis of predicted threshold values of linear energy transfer (LET) in silicon. The program which was stored in the memory found to be changed from 0 to 1 and 1 to 0 state, respectively. On the basis of changed states, the cross-sections ({sigma}) were calculated to investigate the single event effects/upsets. No upset was observed in case of {alpha}-particle since it has very low LET, but the SEU cross-section found to be more in case of Iodine i.e. 2.29 x 10{sup -3} cm{sup 2} than that of nickel, 2.12 x 10{sup -3} cm{sup 2} and silver, 2.26 x 10{sup -3}. This mainly attributes that LET for iodine is more as compared to silver and nickel ions, which deposits large amount of energy near the sensitive node of memory cell in the form of electron-hole pairs required to change the state. These measured SEU cross-section were also compared with theoretically predicted values along with the Weibull distribution fit to the ion induced experimental SEU data. The theoretical predicted SEU cross-section 3.27 x 10{sup -3} cm{sup 2} found to be in good agreement with the measured SEU cross-section.

  8. [Relativistic heavy ion research

    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

  9. Heavy ion collisions

    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

  10. Nuclear research with heavy ions

    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

  11. Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice

    Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun; Fornace, Albert J.; Datta, Kamal

    2017-05-01

    Ionizing radiation (IR) is a recognized risk factor for colorectal cancer (CRC) and astronauts undertaking long duration space missions are expected to receive IR doses in excess of permissible limits with implications for colorectal carcinogenesis. Exposure to IR in outer space occurs at low doses and dose rates, and energetic heavy ions due to their high linear energy transfer (high-LET) characteristics remain a major concern for CRC risk in astronauts. Previously, we have demonstrated that intestinal tumorigenesis in a mouse model (APC1638N/+) of human colorectal cancer was significantly higher after exposure to high dose rate energetic heavy ions relative to low-LET γ radiation. The purpose of the current study was to compare intestinal tumorigenesis in APC1638N/+ mice after exposure to energetic heavy ions at high (50 cGy/min) and relatively low (0.33 cGy/min) dose rate. Male and female mice (6-8 weeks old) were exposed to either 10 or 50 cGy of 28Si (energy: 300 MeV/n; LET: 70 keV/μm) or 56Fe (energy: 1000 MeV/n; LET: 148 keV/μm) ions at NASA Space Radiation Laboratory in Brookhaven National Laboratory. Mice (n = 20 mice/group) were euthanized and intestinal and colon tumor frequency and size were counted 150 days after radiation exposure. Intestinal tumorigenesis in male mice exposed to 56Fe was similar for high and low dose rate exposures. Although male mice showed a decreasing trend at low dose rate relative to high dose rate exposures, the differences in tumor frequency between the two types of exposures were not statistically significant after 28Si radiation. In female mice, intestinal tumor frequency was similar for both radiation type and dose rates tested. In both male and female mice intestinal tumor size was not different after high and low dose rate radiation exposures. Colon tumor frequency in male and female mice after high and low dose rate energetic heavy ions was also not significantly different. In conclusion, intestinal and colonic tumor

  12. Heavy ion accelerator GANIL

    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

  13. Heavy-ion microscopy

    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

  14. Relativisitic heavy ion collisions

    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

  15. Heavy-ion radiography and heavy-ion computed tomography

    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

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

    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.

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

    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

  18. Investigation of structural materials of reactors using high-energy heavy-ion irradiations

    Wang Zhiguang

    2007-01-01

    Radiation damage in structural materials of fission/fusion reactors is mainly attributed to the evolution of intensive atom displacement damage induced by energetic particles (n, α and/or fission fragments) and high-rate helium doping by direct α particle bombardments and/or (n, α) reactions. It can cause severe degradation of reactor structural materials such as surface blistering, bulk void swelling, deformation, fatigue, embrittlement, stress erosion corrosion and so on that will significantly affect the operation safety of reactors. However, up to now, behavior of structural materials at the end of their service can hardly be fully tested in a real reactor. In the present work, damage process in reactor structural materials is briefly introduced, then the advantages of energetic ion implantation/irradiation especially high-energy heavy ion irradiation are discussed, and several typical examples on simulation of radiation effects in reactor candidate structural materials using high-energy heavy ion irradiations are pronounced. Experimental results and theoretical analysis suggested that irradiation with energetic particles especially high-energy heavy ions is very useful technique for simulating the evolution of microstructures and macro-properties of reactor structural materials. Furthermore, an on-going plan of material irradiation experiments using high energy H- and He-ions based on the Heavy Ion Research Facilities in Lanzhou (HIRFL) is also briefly interpreted. (authors)

  19. Investigations on heavy ion induced Single-Event Transients (SETs) in highly-scaled FinFETs

    Gaillardin, M., E-mail: marc.gaillardin@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Raine, M.; Paillet, P. [CEA, DAM, DIF, F-91297 Arpajon (France); Adell, P.C. [Jet Propulsion Laboratory, Pasadena, CA 91101 (United States); Girard, S. [Université de Saint-Etienne, Laboratoire H. Curien, UMR-5516, 42000 Saint-Etienne (France); Duhamel, O. [CEA, DAM, DIF, F-91297 Arpajon (France); Andrieu, F.; Barraud, S.; Faynot, O. [CEA, LETI-Minatec, 17 avenue des Martyrs, 38000 Grenoble (France)

    2015-12-15

    We investigate Single-Event Transients (SET) in different designs of multiple-gate devices made of FinFETs with various geometries. Heavy ion experimental results are explained by using a thorough charge collection analysis of fast transients measured on dedicated test structures. Multi-level simulations are performed to get new insights into the charge collection mechanisms in multiple-gate devices. Implications for multiple-gate device design hardening are finally discussed.

  20. Swift heavy ions induced surface modifications in Ag-polypyrrole composite films synthesized by an electrochemical route

    Kumar, Vijay; Ali, Yasir; Sharma, Kashma; Kumar, Vinod; Sonkawade, R.G.; Dhaliwal, A.S.; Swart, H.C.

    2014-01-01

    Highlights: • Two steps electrochemical synthesis for the fabrication of Ag-polypyrrole composite films. • Surface modifications by swift heavy ion beam. • SEM image shows the formation of craters and humps after irradiation. • Detailed structural analysis by Raman spectroscopy. - Abstract: The general aim of this work was to study the effects of swift heavy ions on the properties of electrochemically synthesized Ag-polypyrrole composite thin films. Initially, polypyrrole (PPy) films were electrochemically synthesized on indium tin oxide coated glass surfaces using a chronopotentiometery technique, at optimized process conditions. The prepared PPy films have functioned as working electrodes for the decoration of submicron Ag particles on the surface of the PPy films through a cyclicvoltammetry technique. Towards probing the effect of swift heavy ion irradiation on the structural and morphological properties, the composite films were subjected to a 40 MeV Li 3+ ion beam irradiation for various fluences (1 × 10 11 , 1 × 10 12 and 1 × 10 13 ions/cm 2 ). Comparative microstructural investigations were carried out after the different ion fluences using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy and micro-Raman spectroscopy techniques. Raman and SEM studies revealed that the structure of the films became disordered after irradiation. The SEM studies of irradiated composite films show significant changes in their surface morphologies. The surface was smoother at lower fluence but craters were observed at higher fluence

  1. Swift heavy ions induced surface modifications in Ag-polypyrrole composite films synthesized by an electrochemical route

    Kumar, Vijay, E-mail: vijays_phy@rediffmail.com [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Ali, Yasir [Department of Physics, Sant Longowal Institute of Engineering and Technology, Longowal, District Sangrur 148106, Punjab (India); Sharma, Kashma [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Department of Chemistry, Shoolini University of Biotechnology and Management Sciences, Solan 173212 (India); Kumar, Vinod [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Sonkawade, R.G. [Inter University Accelerator Center, Aruna Asif Ali Marg, New Delhi 110067 (India); Dhaliwal, A.S. [Department of Physics, Sant Longowal Institute of Engineering and Technology, Longowal, District Sangrur 148106, Punjab (India); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa)

    2014-03-15

    Highlights: • Two steps electrochemical synthesis for the fabrication of Ag-polypyrrole composite films. • Surface modifications by swift heavy ion beam. • SEM image shows the formation of craters and humps after irradiation. • Detailed structural analysis by Raman spectroscopy. - Abstract: The general aim of this work was to study the effects of swift heavy ions on the properties of electrochemically synthesized Ag-polypyrrole composite thin films. Initially, polypyrrole (PPy) films were electrochemically synthesized on indium tin oxide coated glass surfaces using a chronopotentiometery technique, at optimized process conditions. The prepared PPy films have functioned as working electrodes for the decoration of submicron Ag particles on the surface of the PPy films through a cyclicvoltammetry technique. Towards probing the effect of swift heavy ion irradiation on the structural and morphological properties, the composite films were subjected to a 40 MeV Li{sup 3+} ion beam irradiation for various fluences (1 × 10{sup 11}, 1 × 10{sup 12} and 1 × 10{sup 13} ions/cm{sup 2}). Comparative microstructural investigations were carried out after the different ion fluences using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy and micro-Raman spectroscopy techniques. Raman and SEM studies revealed that the structure of the films became disordered after irradiation. The SEM studies of irradiated composite films show significant changes in their surface morphologies. The surface was smoother at lower fluence but craters were observed at higher fluence.

  2. Raman investigation of lattice defects and stress induced in InP and GaN films by swift heavy ion irradiation

    Hu, P.P. [Institute of Modern Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000 (China); University of Chinese Academy of Sciences (UCAS), Beijing 100049 (China); Liu, J., E-mail: J.Liu@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000 (China); Zhang, S.X. [Institute of Modern Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000 (China); University of Chinese Academy of Sciences (UCAS), Beijing 100049 (China); Maaz, K. [Institute of Modern Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000 (China); Nanomaterials Research Group, Physics Division, PINSTECH, Nilore, 45650 Islamabad (Pakistan); Zeng, J. [Institute of Modern Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000 (China); Guo, H. [Institute of Modern Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000 (China); University of Chinese Academy of Sciences (UCAS), Beijing 100049 (China); Zhai, P.F.; Duan, J.L.; Sun, Y.M.; Hou, M.D. [Institute of Modern Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000 (China)

    2016-04-01

    InP crystals and GaN films were irradiated by swift heavy ions {sup 86}Kr and {sup 209}Bi with kinetic energies of 25 and 9.5 MeV per nucleon and ion fluence in the range 5 × 10{sup 10} to 3.6 × 10{sup 12} ions/cm{sup 2}. The characteristic optical bands were studied by Raman spectroscopy to reveal the disorder and defects induced in the samples during the irradiation process. The crystallinity of InP and GaN was found to be deteriorated after irradiation by the swift heavy ions and resulted in the amorphous nature of the samples along the ion tracks. The amorphous tracks observed by transmission electron microscopy (TEM) images confirmed the formation of lattice defects. In typical F{sub 2}(LO) mode, in case of InP, the spectra shifted towards the lower wavenumbers with a maximum shift of 7.6 cm{sup −1} induced by 1030 MeV Bi ion irradiation. While in case of GaN, the typical E{sub 2}(high) mode shifted towards the higher wavenumbers, with maximum shift of 5.4 cm{sup −1} induced by 760 MeV Bi ion irradiation at ion fluence of 1 × 10{sup 12} ions/cm{sup 2}. The observed Raman shifts reveal the presence of lattice defects and disorder induced in the samples after irradiation by the swift heavy ions. This irradiation also generated lattice stress in the samples, which has been investigated and discussed in detail in this work.

  3. Heavy-ion radiography

    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

  4. Compensation of head-on beam-beam induced resonance driving terms and tune spread in the Relativistic Heavy Ion Collider

    W. Fischer

    2017-09-01

    Full Text Available A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC at Brookhaven National Laboratory [Phys. Rev. Lett. 115, 264801 (2015PRLTAO0031-900710.1103/PhysRevLett.115.264801]. The compensation consists of electron lenses for the reduction of the beam-beam induced tune spread, and a lattice for the minimization of beam-beam generated resonance driving terms. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

  5. Fusion-fission dynamics

    Blocki, J.; Planeta, R.; Brzychczyk, J.; Grotowski, K.

    1992-01-01

    Classical dynamical calculations of the heavy ion induced fission processes have been performed for the reactions 40 Ar+ 141 Pr, 20 Ne+ 165 Ho and 12 C+ 175 Lu leading to the iridium like nucleus. As a result prescission lifetimes were obtained and compared with the experimental values. The comparison between the calculated and experimental lifetimes indicates that the one-body dissipation picture is much more relevant in describing the fusion-fission dynamics than the two-body one. (orig.)

  6. Heavy ion fusion III

    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

  7. Relativistic heavy ion reactions

    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.

  8. Relativistic heavy ion physics

    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.)

  9. Relativistic heavy ion reactions

    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

  10. Current experimental situation in heavy-ion reactions

    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

  11. Heavy ion fusion

    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

  12. Failla Memorial lecture. The future of heavy-ion science in biology and medicine.

    Tobias, C A

    1985-07-01

    Interplanetary space contains fluxes of fast moving atomic nuclei. The distribution of these reflects the atomic composition of the universe, and such particles may pose limitations for space flight and for life in space. Over the past 50 years, since the invention of Ernest Lawrence's cyclotron, advances in accelerator technology have permitted the acceleration of charged nuclei to very high velocities. Currently, beams of any stable isotope species up to uranium are available at kinetic energies of several hundred MeV/nucleon at the Berkeley Bevalac. Recently, new areas of particle physics research relating to the mechanisms of spallation and fission have opened up for investigation, and it is now realistic to search for nuclear super-dense states that might be produced in heavy nuclear collisions. The heavy ions hold interest for a broad spectrum of research because of their effectiveness in producing a series of major lesions in DNA along single particle tracks and because of the Bragg depth ionization properties that allow the precise deposition of highly localized doses deep in the human body. Individual heavy ions can also interrupt the continuity of membraneous regions in cells. Heavy ions, when compared to low-LET radiation, have increased effectiveness for mammalian cell lethality, chromosome mutations, and cell transformation. The molecular mechanisms are not completely understood but appear to involve fragmentation and reintegration of DNA. Cells attempt to repair these lesions, and many of the deleterious effects are due to misrepair or misrejoining of DNA. Heavy ions do not require the presence of oxygen for producing their effects, and hypoxic cells in necrotic regions have nearly the same sensitivity as cells in well-oxygenated tissues. Heavy ions are effective in delaying or blocking the cell division process. Heavy ions are also strong enhancers of viral-induced cell transformation, a process that requires integration of foreign DNA. Some cell

  13. Modifications induced by swift heavy ions on poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) and poly(ε-caprolactone) (PCL). Part 2. Radicals characterization

    Rouxhet, L.; Mestdagh, M.; Legras, R.

    2000-01-01

    Modifications induced by different energetic heavy ions ( 40 Ar 9+ , 80 Kr 15+ , 129 Xe 24+ , 208 Pb 53+ and 208 Pb 56+ ) on poly(ε-caprolactone) (PCL) and poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) have been investigated by electron spin resonance (ESR). Indeed, film irradiation by heavy ions leads to, among other phenomena, the formation of radicals in the ion tracks. Thanks to ESR, it is possible to detect these radicals and to identify them or at least to characterize them by following the evolution of the radical signal as a function of parameters, like temperature, or the kinetic of disappearance of the radical species at ambient temperature in vacuum or ambient atmosphere. This study confirmed the generation of radicals by the irradiation of PHB/HV samples with energetic heavy ions reported in the literature. The study on PCL was not pursued after a few preliminary studies, revealing the presence of an ESR signal in the non-irradiated sample. Electronic stopping power has a major influence on radical decrease at ambient temperature. The ion used for the irradiation did not modify very much the radical signal and the evolution of the radicalar signal intensity with temperature. Different reasoning and experiments revealed that the glass transition temperature is a key temperature above which irreversible recombinations of the most stable radicals take place. A simulation study indicated that the most stable radical produced was probably a tertiary radical formed by the stabilization of the secondary radical resulting from the abstraction of a highly mobile hydrogen adjacent to the carbonyl

  14. Defect induced modification of structural, topographical and magnetic properties of zinc ferrite thin films by swift heavy ion irradiation

    Raghavan, Lisha [Department of Physics, Cochin University of Science and Technology, Cochin 682022 (India); Inter University Accelerator Center, New Delhi 110067 (India); Joy, P.A. [National Chemical Laboratory, Pune (India); Vijaykumar, B. Varma; Ramanujan, R.V. [School of Materials Science and Engineering, Nanyang Technological University (Singapore); Anantharaman, M.R., E-mail: mraiyer@gmail.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022 (India)

    2017-04-01

    Highlights: • Zinc ferrite films exhibited room temperature ferrimagnetic property. • On ion irradiation amorphisation of films were observed. • The surface morphology undergoes changes with ion irradiation. • The saturation magnetisation decreases on ion irradiation. - Abstract: Swift heavy ion irradiation provides unique ways to modify physical and chemical properties of materials. In ferrites, the magnetic properties can change significantly as a result of swift heavy ion irradiation. Zinc ferrite is an antiferromagnet with a Neel temperature of 10 K and exhibits anomalous magnetic properties in the nano regime. Ion irradiation can cause amorphisation of zinc ferrite thin films; thus the role of crystallinity on magnetic properties can be examined. The influence of surface topography in these thin films can also be studied. Zinc ferrite thin films, of thickness 320 nm, prepared by RF sputtering were irradiated with 100 MeV Ag ions. Structural characterization showed amorphisation and subsequent reduction in particle size. The change in magnetic properties due to irradiation was correlated with structural and topographical effects of ion irradiation. A rough estimation of ion track radius is done from the magnetic studies.

  15. Relativistic heavy ion collisions

    Barz, H.W.; Kaempfer, B.; Schulz, H.

    1984-12-01

    An elementary introduction is given into the scenario of relativistic heavy ion collisions. It deals with relativistic kinematics and estimates of energy densities, extrapolations of the present knowledge of hadron-hadron and hadron-nuleus to nucleus-nucleus collisions, the properties of the quark-gluon plasma and the formation of the plasma and possible experimental signatures. Comments are made on a cosmic ray experiment which could be interpreted as a first indication of the quark-gluon phase of the matter. (author)

  16. Heavy ion storage rings

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  17. [Relativistic heavy ion research

    1991-01-01

    The present document describes our second-year application for a continuation grant on relativistic heavy-ion research at Nevis Laboratories, Columbia University, over the two-year period starting from November 15, 1990. The progress during the current budget year is presented. This year, construction of RHIC officially began. As a result, the entire Nevis nuclear physics group has made a coherent effort to create new proposal for an Open Axially Symmetric Ion Spectrometer (OASIS) proposal. Future perspectives and our plans for this proposal are described

  18. European heavy ion ICF driver development

    Plass, Günther

    1996-01-01

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

  19. Neutron-induced fission cross sections

    Weigmann, H.

    1991-01-01

    In the history of fission research, neutron-induced fission has always played the most important role. The practical importance of neutron-induced fission rests upon the fact that additional neutrons are produced in the fission process, and thus a chain reaction becomes possible. The practical applications of neutron-induced fission will not be discussed in this chapter, but only the physical properties of one of its characteristics, namely (n,f) cross sections. The most important early summaries on the subject are the monograph edited by Michaudon which also deals with the practical applications, the earlier review article on fission by Michaudon, and the review by Bjornholm and Lynn, in which neutron-induced fission receives major attention. This chapter will attempt to go an intermediate way between the very detailed theoretical treatment in the latter review and the cited monograph which emphasizes the applied aspects and the techniques of fission cross-section measurements. The more recent investigations in the field will be included. Section II will survey the properties of cross sections for neutron-induced fission and also address some special aspects of the experimental methods applied in their measurement. Section Ill will deal with the formal theory of neutron-induced nuclear reactions for the resolved resonance region and the region of statistical nuclear reactions. In Section IV, the fission width, or fission transmission coefficient, will be discussed in detail. Section V will deal with the broader structures due to incompletely damped vibrational resonances, and in particular will address the special case of thorium and neighboring isotopes. Finally, Section VI will briefly discuss parity violation effects in neutron-induced fission. 74 refs., 14 figs., 3 tabs

  20. Some aspects of heavy ion macrophysics

    Ngo, C.

    1984-07-01

    In these notes we review, in a schematic way, some aspect of the physics with heavy ions. In the first lecture we review how is possible to describe the dissipative phenomena observed above the Coulomb barrier, up to 10-15 MeV/u, using transport theories. The second lecture is devoted to the question of fusion and the appearance of a new mechanism: fast fission. It is shown that one can now have a global understanding of these phenomena within single picture. The third lecture presents, in a simplified way, some results obtained recently with heavy ions in the range of 30-50 MeV/u at GANIL and SARA

  1. Relativistic heavy-ion physics

    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.

  2. Relativistic heavy ion physics

    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

  3. Heavy ion fusion

    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

  4. Heavy ion accelerating structure

    Pottier, Jacques.

    1977-01-01

    The heavy ion accelerating structure concerned in this invention is of the kind that have a resonance cavity inside which are located at least two longitudinal conducting supports electrically connected to the cavity by one of their ends in such a way that they are in quarter-wavelength resonance and in phase opposition. Slide tubes are electrically connected alternatively to one or the other of the two supports, they being electrically connected respectively to one or the other end of the side wall of the cavity. The feature of the structure is that it includes two pairs of supports symmetrically placed with respect to the centre line of the cavity, the supports of one pair fitted overhanging being placed symmetrically with respect to the centre line of the cavity, each slide tube being connected to the two supports of one pair. These support are connected to the slide wall of the cavity by an insulator located at their electrically free end. The accelerator structure composed of several structures placed end to end, the last one of which is fed by a high frequency field of adjustable amplitude and phase, enables a heavy ion linear accelerator to be built [fr

  5. Compact time-zero detector for heavy ions

    Weissenberger, E.; Kast, W.; Goennenwein, F.

    1979-01-01

    A time-zero detector for flight-time measurements with heavy ions is described. The ions traverse a thin foil and the secondary electrons splashed from the foil are detected in a channel plate multiplier. A timing signal is derived from the multiplier pulse. The novel features of the detector are its simplicity and compactness of design. The time resolution achieved for the full energy and mass span of fission fragments from the spontaneous fission of 252 Cf used as a heavy ion source is 115 ps (fwhm). (Auth.)

  6. Dynamical features of nuclear fission

    Wheeler underestimates several observables in heavy-ion-induced ... excitation energies, there may not be sufficient nuclei near the fission barrier after the .... Dissipation in nuclear dynamics in the mean-field regime accounts for the coupling of the .... barrier for different isotopes of Fr. The lines are drawn to guide the eye.

  7. Study of the mechanisms of heavy-ion induced desorption on accelerator-relevant materials; Untersuchung der Mechanismen schwerioneninduzierter Desorption an beschleunigerrelevanten Materialien

    Bender, Markus

    2008-02-22

    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.)

  8. Muon induced fission and fission track dating of minerals

    Marques, A.

    1988-01-01

    The effects of muon induced fission on geological dating of samples by the fission track method are evaluated for the case of muscovite minerals. It is found a small but significant effect, greater for the longer ages. Since calculations are developped under the hypothesis of constant atmosphere and primary cosmic ray flux it is suggested that any discrepancy found in ages of very old material that cannot be accounted for by well known environmental influences, be taken as an indication of variation on either the atmospheric stopping power or the intensity of cosmic radiation along the ages. (author) [pt

  9. Nuclear fission and neutron-induced fission cross-sections

    James, G D; Michaudon, A; Michaudon, A; Cierjacks, S W; Chrien, R E

    2013-01-01

    Nuclear Fission and Neutron-Induced Fission Cross-Sections is the first volume in a series on Neutron Physics and Nuclear Data in Science and Technology. This volume serves the purpose of providing a thorough description of the many facets of neutron physics in different fields of nuclear applications. This book also attempts to bridge the communication gap between experts involved in the experimental and theoretical studies of nuclear properties and those involved in the technological applications of nuclear data. This publication will be invaluable to those interested in studying nuclear fis

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

    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)

  11. Induced-Fission Imaging of Nuclear Material

    Hausladen, Paul; Blackston, Matthew A.; Mullens, James Allen; McConchie, Seth M.; Mihalczo, John T.; Bingham, Philip R.; Ericson, Milton Nance; Fabris, Lorenzo

    2010-01-01

    This paper presents initial results from development of the induced-fission imaging technique, which can be used for the purpose of measuring or verifying the distribution of fissionable material in an unopened container. The technique is based on stimulating fissions in nuclear material with 14 MeV neutrons from an associated-particle deuterium-tritium (D-T) generator and counting the subsequent induced fast fission neutrons with an array of fast organic scintillation detectors. For each source neutron incident on the container, the neutron creation time and initial trajectory are known from detection of the associated alpha particle of the d + t → α + n reaction. Many induced fissions will lie along (or near) the interrogating neutron path, allowing an image of the spatial distribution of prompt induced fissions, and thereby fissionable material, to be constructed. A variety of induced-fission imaging measurements have been performed at Oak Ridge National Laboratory with a portable, low-dose D-T generator, including single-view radiographic measurements and three-dimensional tomographic measurements. Results from these measurements will be presented along with the neutron transmission images that have been performed simultaneously. This new capability may have applications to a number of areas in which there may be a need to confirm the presence or configuration of nuclear materials, such as nuclear material control and accountability, quality assurance, treaty confirmation, or homeland security applications.

  12. Heavy ion inertial fusion

    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.)

  13. Relativistic heavy ion physics

    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

  14. Heavy ion beam probing

    Hickok, R.L.

    1980-07-01

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

  15. Heavy ion inertial fusion

    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

  16. HEAVY ION LINEAR ACCELERATOR

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

    1959-01-01

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

  17. Heavy-ion superconducting linacs

    Delayen, J.R.

    1989-01-01

    This paper reviews the status of the superconducting heavy-ion accelerators. Most of them are linacs used as boosters for tandem electrostatic accelerators, although the technology is being extended to very low velocity to eliminate the need for an injector. The characteristics and features of the various superconducting heavy-ion accelerators are discussed. 45 refs

  18. Heavy-ion superconducting linacs

    Delayen, J.R.

    1989-01-01

    This paper reviews the status of the superconducting heavy-ion accelerators. Most of them are linacs used as boosters for tandem electrostatic accelerators, although the technology is being extended to very low velocity to eliminate the need for an injector. The characteristics and features of the various superconducting heavy-ion accelerators are discussed. 45 refs.

  19. Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

    Yu, H.; Yao, Z.; Kirk, M.A.; Daymond, M.R.

    2015-01-01

    In situ heavy ion irradiation with 1 MeV Kr"2"+ was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 "oC or 450 "oC. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 "oC irradiation but not at 450 "oC. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2 and both present in β-Zr under room temperature irradiation. (author)

  20. Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

    Yu, H.; Yao, Z., E-mail: 12hy1@queensu.ca [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada); Kirk, M.A. [Argonne National Laboratory, Materials Science Division, Argonne, IL (United States); Daymond, M.R. [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada)

    2015-07-01

    In situ heavy ion irradiation with 1 MeV Kr{sup 2+} was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 {sup o}C or 450 {sup o}C. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 {sup o}C irradiation but not at 450 {sup o}C. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2<111> and <001> both present in β-Zr under room temperature irradiation. (author)

  1. Detection of DNA lesion induced by heavy ion irradiation using DNA repair related proteins in cultured cells

    Eguchi-Kasai, Kiyomi; Tsujita, Sena

    2006-01-01

    We studied the localization of phosphorylated H2AX (γ-H2AX) in cultured human fibroblasts after irradiation with heavy ion beams. Asynchronous human normal fibroblasts (NB1RGB) were irradiated with X-rays, C (LET≅85 keV/μm), Si (240 keV/μm), Ar (85 keV/μm), and Fe (440 keV/μm) ion beams. Gamma-H2AX was measured in irradiated cells from 0 to 24 h after irradiation using flow cytometry. The fluorescent signal of γ-H2AX increased just after irradiation of each radiation and reached maximum around 30 nun and then, decreased. At 30 min after irradiation, γ-H2AX signal increased with increasing the radiation dose for both X-rays and Fe ion. The slope of fitting line for the Fe ion was bigger than that of X-rays. Foci of γ-H2AX on cell nuclei were counted under the laser scanning confocal microscopy at 30 min after. Number of foci per nucleus was increased with increasing dose of each radiation. (author)

  2. Transmission electron microscopy study of the heavy-ion-irradiation-induced changes in the nanostructure of oxide dispersion strengthened steels

    Rogozhkin, S. V.; Bogachev, A. A.; Orlov, N. N.; Korchuganova, O. A.; Nikitin, A. A.; Zaluzhnyi, A. G.; Kozodaev, M. A.; Kulevoy, T. V.; Kuibeda, R. P.; Fedin, P. A.; Chalykh, B. B.; Lindau, R.; Hoffman, Ya.; Möslang, A.; Vladimirov, P.; Klimenkov, M.

    2017-07-01

    Transmission electron microscopy was used to study the effect of heavy-ion irradiation on the structure and the phase state of three oxide dispersion strengthened (ODS) steels: ODS Eurofer, ODS 13.5Cr, and ODS 13.5Cr-0.3Ti (wt %). Samples were irradiated with iron and titanium ions to fluences of 1015 and 3 × 1015 cm-2 at 300, 573, and 773 K. The study of the region of maximum radiation damage shows that irradiation increases the number density of oxide particles in all samples. The fraction of fine inclusions increases in the particle size distribution. This effect is most pronounced in the ODS 13.5Cr steel irradiated with titanium ions at 300 K to a fluence of 3 × 1015 cm-2. It is demonstrated that oxide inclusions in ODS 13.5Cr-0.3Ti and ODS 13.5Cr steels are more stable upon irradiation at 573 and 773 K than upon irradiation at 300 K.

  3. Application of pulse shape discrimination in Si detector for fission ...

    Pulse shape discrimination (PSD) with totally depleted transmission type Si surface barrier detector in reverse mount has been investigated to identify fission fragments in the presence of elastic background in heavy ion-induced fission reactions by both numerical simulation and experimental studies. The PSD method is ...

  4. Nuclear research with heavy ions. Annual progress report, January 1, 1977--December 31, 1977

    Kaplan, M.

    1977-10-01

    The experimental research program consists of several interrelated parts: (1) Reactions of Very Heavy Ions with Complex Nuclei; (2) Studies of Compound Nucleus Reactions Induced by Heavy Ions; and (3) Recoil Studies of Heavy Ion Reactions. Using solid-state detector telescopes and gas-ionization detector telescopes we have studied the emission of 1 H, 2 H, 3 H, 4 He and heavy fragments from the reactions of 720 MeV 86 Kr with 197 Au. Coincidence measurements between light charged particles and a heavy fragment indicate that most of the observed 4 He particles are evaporated by equilibrated Kr*-like and Au*-like excited products from deep inelastic reactions, but a significant number of preequilibrium 4 He particles seem to be emitted in directions normal to the separating fragments. Studies of angular correlations between two heavy fragments provide strong evidence for sequential fission of the Au*-like reaction fragments, and the probability of this process has been estimated as a function of Q, the energy damping in the primary collision. Parallel studies of charged particle emission, fission, and evaporation residues in compound nucleus reactions map out the de-excitation characteristics of highly excited heavy nuclei as functions of E* and J. Results are presented for the compound nucleus 194 Hg formed at matched excitation energies via different entrance channels

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

    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

  6. Dynamical chaos and induced nuclear fission

    Bolotin, Yu L; Krivoshej, I V

    1985-01-01

    It is shown that the exponential instability of trajectories, which arises at negative curvature of the potential energy surface, leads to diffusion of the image point through the barrier and determines real time delays in induced nuclear fission.

  7. Heavy ion elastic scatterings

    Mermaz, M.C.

    1984-01-01

    Diffraction and refraction play an important role in particle elastic scattering. The optical model treats correctly and simultaneously both phenomena but without disentangling them. Semi-classical discussions in terms of trajectories emphasize the refractive aspect due to the real part of the optical potential. The separation due to to R.C. Fuller of the quantal cross section into two components coming from opposite side of the target nucleus allows to understand better the refractive phenomenon and the origin of the observed oscillations in the elastic scattering angular distributions. We shall see that the real part of the potential is responsible of a Coulomb and a nuclear rainbow which allows to determine better the nuclear potential in the interior region near the nuclear surface since the volume absorption eliminates any effect of the real part of the potential for the internal partial scattering waves. Resonance phenomena seen in heavy ion scattering will be discussed in terms of optical model potential and Regge pole analysis. Compound nucleus resonances or quasi-molecular states can be indeed the more correct and fundamental alternative

  8. Relativistic heavy ion research

    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

  9. Ultrarelativistic heavy ions

    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

  10. Nuclear research with heavy ions. Annual progress report, January 1, 1981-December 31, 1981

    Kaplan, M.

    1981-11-01

    The experimental research program is primarily concerned with the nuclear reactions induced by collisions between heavy-ion projectiles and complex target nuclei, the dynamics and thermodynamics associated with such collisions, and the relationships of the observables to the equilibrium and non-equilibrium properties of nuclear matter. As a sensitive probe of the nuclear interactions, detailed measurements of light-charged-particle emission were performed using counter telescopes for atomic number and mass number identification. Preliminary results from a new experiment on direct and evaporation-like emission of 4 He from reactions of 340-MeV 40 Ar with 238 U are reported. Using a large two-dimensional position-sensitive avalanche detector, and measuring three-fold coincidence events between two fission fragments and an emitted 4 He particle, we were able to distinguish emission processes in fusion-like fission from those associated with inelastic reactions. Analysis of the data shows isotropic and strongly forward-peaked 4 He components for both fusion and sequential fission, and kinematic evidence indicates substantial evaporation-like emission from the composite system rather than from fission fragments. The effects of light element impurities on charged particle spectra from heavy ion collisions are discussed, and a technique for directly evaluating the impurity contribution is briefly described

  11. Prospects for high energy heavy ion accelerators

    Leemann, C.

    1979-03-01

    The acceleration of heavy ions to relativistic energies (T greater than or equal to 1 GeV/amu) at the beam intensities required for fundamental research falls clearly in the domain of synchrotons. Up to date, such beams have been obtained from machines originally designed as proton acccelerators by means of modified RF-programs, improved vacuum and, most importantly, altered or entirely new injector systems. Similarly, for the future, substantial changes in synchrotron design itself are not foreseen, but rather the judicious application and development of presently known principles and technologies and a choice of parameters optimized with respect to the peculiarities of heavy ions. The low charge to mass ratio, q/A, of very heavy ions demands that superconducting magnets be considered in the interest of the highest energies for a given machine size. Injector brightness will continue to be of highest importance, and although space charge effects such as tune shifts will be increased by a factor q 2 /A compared with protons, advances in linac current and brightness, rather than substantially higher energies are required to best utilize a given synchrotron acceptance. However, high yeilds of fully stripped, very heavy ions demand energies of a few hundred MeV/amu, thus indicating the need for a booster synchrotron, although for entirely different reasons than in proton facilities. Finally, should we consider colliding beams, the high charge of heavy ions will impose severe current limitations and put high demands on system design with regard to such quantities as e.g., wall impedances or the ion induced gas desorption rate, and advanced concepts such as low β insertions with suppressed dispersion and very small crossing angles will be essential to the achievement of useful luminosities

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

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

    2015-01-01

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

  13. Heavy Ion Physics at LHC

    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 .

  14. BNL heavy ion fusion program

    Maschke, A.W.

    1978-01-01

    A principal attraction of heavy ion fusion is that existing accelerator technology and theory are sufficiently advanced to allow one to commence the design of a machine capable of igniting thermonuclear explosions. There are, however, a number of features which are not found in existing accelerators built for other purposes. The main thrust of the BNL Heavy Ion Fusion program has been to explore these features. Longitudinal beam bunching, very low velocity acceleration, and space charge neutralization are briefly discussed

  15. Statistical and dynamical aspects in fission process: The rotational ...

    the fission process, during the evolution from compound nucleus to the ..... For fission induced by light particles like n, p, and α, the total angular momenta ... 96 MeV. 16O+232Th. SaddleTSM. 72 MeV. 10B+232Th. 1.2. 1.4. 1.6. 1.8. 80 ... Systematic investigations in both light- and heavy-ion-induced fissions have shown that.

  16. Heavy ion reactions in the transition region

    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

  17. Heavy ion medical accelerator, HIMAC

    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)

  18. Study of transfer induced fission and fusion-fission reactions for 28 Si + 232 Th system at 340 MeV

    Prete, G.; Rizzi, V.; Fioretto, E.; Cinausero, M.; Shetty, D.V.; Pesente, S.; Brondi, A.; La Rana, G.; Moro, R.; Vardaci, E.; Boiano, A.; Ordine, A.; Gelli, N.; Lucarelli, F.; Bortignon, P.F.; Saxena, A.; Nayak, B.K.; Biswas, D.C.; Choudhury, R.K.; Kapoor, R.S.

    2001-01-01

    Full text: Fission induced by nucleons transfer has been investigated in the reaction 28 Si + 232 Th at 340 MeV. Looking at the projectile-like-fragments (PLF), the fission yield increases as the transfer increases, but a decreases is observed for transfers with DZ . Light charged particles in coincidence with PLF and Fission have been detected with large solid angle and show an increasing multiplicity as the Z of PLF is reduced and a constant value when fission is requested. The present results indicate inhibition of transfer induced fission reaction for higher Z transfer and increasing probability for decay through charged particle evaporation. Fission is the dominant decay process in heavy reactions involving fissile systems but the dynamical evolution of the composite system is largely governed by the formation and decay mechanisms. Important insight into the formation and the survival probability of the heavy composite nuclei formed in heavy ion collisions can be gained by simultaneously investigate the fission process and light particle emission over a continuous range of excitation energy, angular momentum and fissility. This can be achieved by studying fission induced by transfer of nucleons between the interacting projectile and the target nucleus. In the present work, we have carried out measurements on multinucleon transfer induced fission reactions in 28 Si + 232 Th system at Elab = 340 MeV. The experiment has been performed at the Laboratori Nazionale di Legnaro (LNL) using the 8pLP detector in its final configuration with 257 DE-E telescopes. The backward detectors were used to measure both light charged particles and fission fragments. The projectile-like fragments were detected using separate DE-E telescopes around the grazing angle. Two neutron detectors were placed at a distance of 115.5 cm from the target to measure neutrons emitted in coincidence with fission fragments. Here we present the results of the data analysis of transfer induced fission

  19. Multiparticle production in heavy-ion reactions

    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.)

  20. Heavy ion inertial fusion - an overview

    Lawson, J.D.

    1983-09-01

    Energetic heavy ions represent an alternative to laser light and light ions as ''drivers'' for supplying energy for inertial confinement fusion. To induce ignition of targets containing thermonuclear fuel, an energy of several megajoules has to be focused on to a target with radius a few millimetres in a time of some tens of nanoseconds. Serious study of the use of heavy ion drivers for producing useful power in this way has been underway for seven years, though funding has been at a low level. In this paper the requirements for targets, accelerator, and reactor vessel for containing the thermonuclear explosion are surveyed, and some of the problems to be solved before the construction of a power station can realistically be contemplated are discussed. (author)

  1. Heavy-ion research at the tandem and superconducting linac accelerators

    Anon.

    1980-01-01

    The heavy-ion research program at the Argonne Physics Division is principally aimed at the study of nuclear structure and its manifestation in heavy-ion induced nuclear reactions. In order to extract information on nuclear structure, measurements with high precision often need to be performed. Such measurements are now carried out at the tandem-linac accelerator over a wide energy range. The investigation of high-spin states near the yrast line has provided much new information on the behavior of nuclei at high angular momentum. Argonne work has concentrated on nuclei where high-spin isomers, the so-called yrast traps, are prevalent. The resonance effects observed previously in the 24 Mg( 16 O, 12 C) 28 Si reactions have been further explored through both additional measurements and a new quantitative method of analysis. The measurements were extended in energy and angular range and to various exit channels as well as similar systems. Several measurements were performed to investigate the reaction mechanisms in heavy-ion induced reactions and to map out the distribution of reaction strength as a function of energy and target-projectile masses energy regions previously not accessible. The behavior of the quasi- and deep-inelastic reaction cross sections was studied as a function of energy for medium-heavy systems, the production of inclusive alpha-particle yields for 16 O beams at energies E/A greater than or equal to 5 MeV/nucleon, and excitation functions, mass and kinetic energy distributions for heavy-ion induced fusion-fission reactions

  2. Ternary fission induced by polarized neutrons

    Gönnenwein Friedrich

    2013-12-01

    Full Text Available Ternary fission of (e,e U- and Pu- isotopes induced by cold polarized neutrons discloses some new facets of the process. In the so-called ROT effect shifts in the angular distributions of ternary particles relative to the fission fragments show up. In the so-called TRI effect an asymmetry in the emission of ternary particles relative to a plane formed by the fragment momentum and the spin of the neutron appear. The two effects are shown to be linked to the components of angular momentum perpendicular and parallel to the fission axis at the saddle point of fission. Based on theoretical models the spectroscopic properties of the collective transitional states at the saddle point are inferred from experiment.

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

    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

  4. Results of heavy ion radiotherapy

    Castro, J.R.

    1994-04-01

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

  5. Heavy ion collisions and cosmology

    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.

  6. Swift Heavy Ions in Matter

    Rothard, Hermann; Severin, Daniel; Trautmann, Christina

    2015-12-01

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

  7. Accelerators for heavy ion fusion

    Bangerter, R.O.

    1985-10-01

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

  8. Relativistic heavy ion facilities: worldwide

    Schroeder, L.S.

    1986-05-01

    A review of relativistic heavy ion facilities which exist, are in a construction phase, or are on the drawing boards as proposals is presented. These facilities span the energy range from fixed target machines in the 1 to 2 GeV/nucleon regime, up to heavy ion colliders of 100 GeV/nucleon on 100 GeV/nucleon. In addition to specifying the general features of such machines, an outline of the central physics themes to be carried out at these facilities is given, along with a sampling of the detectors which will be used to extract the physics. 22 refs., 17 figs., 3 tabs

  9. Central collisions of heavy ions

    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

  10. GROGi-F. Modified version of GROGi 2 nuclear evaporation computer code including fission decay channel

    Delagrange, H.

    1977-01-01

    This report is the user manual of the GR0GI-F code, modified version of the GR0GI-2 code. It calculates the cross sections for heavy ion induced fission. Fission probabilities are calculated via the Bohr-Wheeler formalism

  11. Peripheral heavy-ion induced reactions at intermediate energies 20MeV

    Barrette, J.; Berthier, B.; Chavez, E.

    1984-03-01

    Inclusive energy spectra and angular distributions of projectile like fragments in reactions induced by a 44 MeV/nucleon 40 Ar beam bombarding 27 Al and sup(nat)Ti targets show many of the features of high energy fragmentation. However, several aspects such as energy dissipation and production of fragments heavier than the projectile are reminiscent of a low energy behaviour

  12. Neutron induced current pulses in fission chambers

    Taboas, A.L.; Buck, W.L.

    1978-01-01

    The mechanism of neutron induced current pulse generation in fission chambers is discussed. By application of the calculated detector transfer function to proposed detector current pulse shapes, and by comparison with actually observed detector output voltage pulses, a credible, semi-empirical, trapezoidal pulse shape of chamber current is obtained

  13. In-situ kinetics of modifications induced by swift heavy ions in Al2O3: Colour centre formation, structural modification and amorphization

    Grygiel, C.; Moisy, F.; Sall, M.; Lebius, H.; Balanzat, E.; Madi, T.; Been, T.; Marie, D.; Monnet, I.

    2017-01-01

    This paper details in-situ studies of modifications induced by swift heavy ion irradiation in α-Al2O3. This complex behaviour is intermediary between the behaviour of amorphizable and non-amorphizable materials, respectively. A unique combination of irradiation experiments was performed at the IRRSUD beam line of the GANIL facility, with three different characterisation techniques: in-situ UV–Vis absorption, in-situ grazing incidence X-Ray diffraction and ex-situ transmission electron microscopy. This allows a complete study of point defects, and by depth profile of structural and microstructural modifications created on the trajectory of the incident ion. The α-Al2O3 crystals have been irradiated by 92 MeV Xenon and 74 MeV Krypton ions, the irradiation conditions have been chosen rather similar with an energy range where the ratio between electronic and nuclear stopping power changes dramatically as function of depth penetration. The main contribution of electronic excitation, above the threshold for track formation, is present beneath the surface to finally get almost only elastic collisions at the end of the projected range. Amorphization kinetics by the overlapping of multiple ion tracks is observed. In the crystalline matrix, long range strains, unit-cell swelling, local microstrain, domain size decrease, disordering of oxygen sublattice as well as colour centre formation are found. This study highlights the relationship between ion energy losses into a material and its response. While amorphization requires electronic stopping values above a certain threshold, point defects are predominantly induced by elastic collisions, while some structural modifications of the crystalline matrix, such as unit-cell swelling, are due to contribution of both electronic and nuclear processes.

  14. Systematics of neutron-induced fission yields

    Blachot, J.; Brissot, R.

    1983-10-01

    The main characteristics of the mass and charge distributions for thermal neutron induced fission of actinides are reviewed. We show that these distributions can be reasonably reproduced with only 24 data as input. We use a representation where the element yields together with the most probable mass Ap(Z) play the dominant role. The ability of this model to calculate mass yields for the fission of not yet measured actinides is also shown. The influence of the excitation energy of the fissile system on charge and mass distribution is also discussed

  15. Radiation induced muscositis as space flight risk. Model studies on X-ray and heavy ion irradiated typical oral mucosa models; Strahlungsinduzierte Mukositis als Risiko der Raumfahrt. Modelluntersuchungen an Roentgen- und Schwerionen-bestrahlten organotypischen Mundschleimhaut-Modellen

    Tschachojan, Viktoria

    2014-07-29

    Humans in exomagnetospheric space are exposed to highly energetic heavy ion radiation which can be hardly shielded. Since radiation-induced mucositis constitutes a severe complication of heavy ion radiotherapy, it would also implicate a serious medical safety risk for the crew members during prolonged space flights such as missions to Moon or Mars. For assessment of risk developing radiation-induced mucositis, three-dimensional organotypic cultures of immortalized human keratinocytes and fibroblasts were irradiated with a {sup 12}C particle beam at high energies or X-Rays. Immunofluorescence stainings were done from cryosections and radiation induced release of cytokines and chemokines was quantified by ELISA from culture supernatants. The major focuses of this study were on 4, 8, 24 and 48 hours after irradiation. The conducted analyses of our mucosa model showed many structural similarities with the native oral mucosa and authentic immunological responses to radiation exposure. Quantification of the DNA damage in irradiated mucosa models revealed about twice as many DSB after heavy-ion irradiation compared to X-rays at definite doses and time points, suggesting a higher gene toxicity of heavy ions. Nuclear factor κB activation was observed after treatment with X-rays or {sup 12}C particles. An activation of NF κB p65 in irradiated samples could not be detected. ELISA analyses showed significantly higher interleukin 6 and interleukin 8 levels after irradiation with X-rays and {sup 12}C particles compared to non-irradiated controls. However, only X-rays induced significantly higher levels of interleukin 1β. Analyses of TNF-α and IFN-γ showed no radiation-induced effects. Further analyses revealed a radiation-induced reduction in proliferation and loss of compactness in irradiated oral mucosa model, which would lead to local lesions in vivo. In this study we revealed that several pro-inflammatory markers and structural changes are induced by X-rays and heavy-ion

  16. Future relativistic heavy ion experiments

    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

  17. Summary of heavy ion theory

    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

  18. Deeply inelastic transfer reactions induced by heavy ions in rare earth targets. II. Interpretation of experimental data

    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. Antiproton Induced Fission and Fragmentation of Nuclei

    2002-01-01

    The annihilation of slow antiprotons with nuclei results in a large highly localized energy deposition primarily on the nuclear surface. \\\\ \\\\ The study of antiproton induced fission and fragmentation processes is expected to yield new information on special nuclear matter states, unexplored fission modes, multifragmentation of nuclei, and intranuclear cascades.\\\\ \\\\ In order to investigate the antiproton-nucleus interaction and the processes following the antiproton annihilation at the nucleus, we propose the following experiments: \\item A)~Measurement of several fragments from fission and from multifragmentation in coincidence with particle spectra, especially neutrons and kaons. \\item B)~Precise spectra of $\\pi$, K, n, p, d and t with time-of-flight techniques. \\item C)~Installation of the Berlin 4$\\pi$ neutron detector with a 4$\\pi$ Si detector placed inside for fragments and charged particles. This yields neutron multiplicity distributions and consequently distributions of thermal excitation energies and...

  20. Swift heavy ion irradiation induced modifications in the optical band gap and Urbach's tail in polyaniline nanofibers

    Banerjee, Somik; Kumar, A.

    2011-01-01

    Optical band gap and Urbach tail width of HCl and CSA doped polyaniline (PAni) nanofibers and the ion beam induced modifications in the band gap and Urbach's tail of the samples have been studied employing UV-Vis absorption spectroscopy. All the major bands appearing in the FTIR spectra exhibit a decrease in intensity and broadening in their band widths upon interaction with the highly energetic ion beams. This suggests that SHI irradiation induces chain-scissioning events in the PAni nanofibers. An interesting result that comes out from the FTIR analysis is a transition from the benzenoid to quinoid states in the PAni chains, which reveals that there is a decrease in the degree of conjugation in the polymer upon irradiation. Optical absorption studies indicate three direct allowed transitions at ∼2.64, 3.61 and 4.08 eV for HCl doped PAni nanofibers and at ∼2.62, 3.49 and 4.02 eV for the CSA doped PAni nanofibers. The optical band gap is found to increase with increasing ion fluence which may be attributed to the reduction in the fiber diameters upon irradiation, which is corroborated by TEM analysis. Increase in the optical band gap also points out to a decrease in the conjugation length due to the larger torsion angles between the adjacent phenyl rings of the polymer with respect to the plane of the nitrogen atoms, which is also supported by FTIR results. The Urbach tail width decreases with increasing ion fluence indicating that structural disorders are annealed out of the PAni nanofibers which is also observed from the plots of (αhν) 2 against photon energy (hν) for HCl doped PAni nanofibers. The quantum confinement effect is confirmed by fact that a band gap exhibits a linear dependence on the inverse of the square of the radius of the PAni nanofibers. Infact, the increase in the optical band gap may be a combined effect of the decrease in the Urbach band width and the quantum confinement effect.

  1. (d,p)-transfer induced fission of heavy radioactive beams

    Veselsky, Martin

    2012-01-01

    (d,p)-transfer induced fission is proposed as a tool to study low energy fission of exotic heavy nuclei. Primary goal is to directly determine the fission barrier height of proton-rich fissile nuclei, preferably using the radio-active beams of isotopes of odd elements, and thus confirm or exclude the low values of fission barrier heights, typically extracted using statistical calculations in the compound nucleus reactions at higher excitation energies. Calculated fission cross sections in transfer reactions of the radioactive beams show sufficient sensitivity to fission barrier height. In the probable case that fission rates will be high enough, mass asymmetry of fission fragments can be determined. Results will be relevant for nuclear astrophysics and for production of super-heavy nuclei. Transfer induced fission offers a possibility for systematic study the low energy fission of heavy exotic nuclei at the ISOLDE.

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

    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...

  3. Peripheral collisions of heavy ions induced by 40Ar at intermediate energies: giant resonance high energy structures and projectile fragmentation

    Blumenfeld, Y.

    1987-09-01

    The results obtained in similar studies at low incident energies are first of all reviewed. The time of flight spectrometer built for the experiments is then described. A study of the properties of the projectile-like fragments shows numerous deviations from the relativistic energy fragmentation model. Evidence for a strong surface transfer reaction component is given and the persistence of mean field effects at intermediate energies is stressed. A calculation of the contribution of the transfer evaporation mechanism to the inelastic spectra shows that this mechanism is responible for the major part of the background measured at high excitation energy and can in some cases induce narrow structures in the spectra. The inelastic spectra shows a strong excitation of the giant quadrupole resonance. In the region between 20 and 80 MeV excitation energy narrow structures are present for all the studied systems. Statistical and Fourier analysises allow to quantify the probabilities of existence, the widths and the excitation energies of these structures. A transfer evaporation hypothesis cannot consistently reproduce all the observed structures. The excitation energies of the structures can be well described by phenomenological laws where the energies are proportional to the -1/3 power of the target mass. Complete calculations of the excitation probabilities of giant resonances and multiphonon states are performed within a model where the nuclear excitation are calculated microscopically in the Random Phase Approximation. It is shown that a possible interpretation of the structures is the excitation of multiphonon states built with 2 + giant resonances [fr

  4. Study of uranium dioxyde sputtering induced by multicharged heavy ions at low and very low kinetic energy: projectile charge effect

    Haranger, F.

    2003-12-01

    Ion beam irradiation of a solid can lead to the emission of neutral or ionized atoms, molecules or clusters from the surface. This comes as a result of the atomic motion in the vicinity of the surface, induced by the transfer of the projectile energy. Then, the study of the sputtering process appears as a means to get a better understanding of the excited matter state around the projectile trajectory. In the case of slow multicharged ions, a strong electronic excitation can be achieved by the projectile neutralization above the solid surface and / or its deexcitation below the surface. Parallel to this, the slowing down of such ions is essentially related to elastic collision with the target atoms. The study of the effect of the initial charge state of slow multicharged ions, in the sputtering process, has been carried out by measuring the absolute angular distributions of emission of uranium atoms from a uranium dioxide surface. The experiments have been performed in two steps. First, the emitted particles are collected onto a substrate during irradiation. Secondly, the surface of the collectors is analyzed by Rutherford Backscattering Spectrometry (RBS). This method allows the characterization of the emission of neutrals, which are the vast majority of the sputtered particles. The results obtained provide an access to the evolution of the sputtering process as a function of xenon projectile ions charge state. The measurements have been performed over a wide kinetic energy range, from 81 down to 1.5 keV. This allowed a clear separation of the contribution of the kinetic energy and initial projectile charge state to the sputtering phenomenon. (author)

  5. Nuclear physics with heavy ions. 1

    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)

  6. A position sensitive parallel plate avalanche fission detector for use in particle induced fission coincidence measurements

    Plicht, J. van der

    1980-01-01

    A parallel plate avalanche detector developed for the detection of fission fragments in particle induced fission reactions is described. The active area is 6 × 10 cm2; it is position sensitive in one dimension with a resolution of 2.5 mm. The detector can withstand a count rate of 25000 fission

  7. BROOKHAVEN: Looking towards heavy ion physics

    Anon.

    1988-01-01

    July 11-22 were busy days at Brookhaven with a two-week Summer Institute on Relativistic Heavy Ion Physics. After an intensive first week designed to introduce young physicists to high energy heavy ion research, the second week was a workshop on detector technology for Brookhaven's proposed Relativistic Heavy Ion Collider (RHIC), attended by some 150 physicists

  8. Therapy tumor with the heavy ions beam

    Dang Bingrong; Wei Zengquan; Li Wenjian

    2002-01-01

    As physical characteristic of heavy ions Bragg peak, therapy tumor with heavy ions is becoming advanced technology. So, many countries have developed the technology and used to treat tumor, the societal and economic effects are beneficial to people. The authors show the development, present situation and information of research in world of advanced radiotherapy with heavy ions

  9. Heavy ions: Report from Relativistic Heavy Ion Collider

    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-.

  10. Ternary fission

    Wagemans, C.

    1991-01-01

    Since its discovery in 1946, light (charged) particle accompanied fission (ternary fission) has been extensively studied, for spontaneous as well as for induced fission reactions. The reason for this interest was twofold: the ternary particles being emitted in space and time close to the scission point were expected to supply information on the scission point configuration and the ternary fission process was an important source of helium, tritium, and hydrogen production in nuclear reactors, for which data were requested by the nuclear industry. Significant experimental progress has been realized with the advent of high-resolution detectors, powerful multiparameter data acquisition systems, and intense neutron and photon beams. As far as theory is concerned, the trajectory calculations (in which scission point parameters are deduced from the experimental observations) have been very much improved. An attempt was made to explain ternary particle emission in terms of a Plateau-Rayleigh hydrodynamical instability of a relatively long cylindrical neck or cylindrical nucleus. New results have also been obtained on the so-called open-quotes trueclose quotes ternary fission (fission in three about-equal fragments). The spontaneous emission of charged particles has also clearly been demonstrated in recent years. This chapter discusses the main characteristics of ternary fission, theoretical models, light particle emission probabilities, the dependence of the emission probabilities on experimental variables, light particle energy distributions, light particle angular distributions, correlations between light particle accompanied fission observables, open-quotes trueclose quotes ternary fission, and spontaneous emission of heavy ions. 143 refs., 18 figs., 8 tabs

  11. Calorimetric cryodetectors for heavy ions

    Egelhof, P; Henning, W; Kienlin, A v; Meier, J; Truebenbacher, V [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany, F.R.) Mainz Univ. (Germany, F.R.). Inst. fuer Physik; Azgui, F [CDTN, Algiers (Algeria); Shepard, K [Argonne National Lab., IL (USA)

    1990-01-01

    Status and first test results are reported for a project to develop calorimetric cryodetectors for heavy ions. The special conditions for the detection of energetic heavy ions are discussed. Presently the investigations are focussed on semiconductor bolometers and aluminium-strip superconducting phase-transition thermometers that are cooled with liquid {sup 4}He and operate in the temperature range 1.3-4.2 K. For a germanium bolometer the temperature dependence of the resistance, voltage-current curves, the time response to heating by voltage pulses and the response to ionizing {alpha}-radiation are reported. First tests on phase transition thermometers using thin aluminum strips yield a transition width of {Delta}T=8.6 mK at T{sub c}=1.467 K. (orig.).

  12. Physics of Ultrarelativistic Heavy Ions

    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

  13. RHIC heavy ion operations performance

    Satogata, T; Ferrone, R; Pilat, F

    2006-01-01

    The Relativistic Heavy Ion Collider (RHIC) completed its fifth year of operation in 2005, colliding copper ion beams with ps=200 GeV/u and 62.4 GeV/u[1]. Previous heavy ion runs have collided gold ions at ps=130 GeV/u, 200 GeV/u, and 62.4 GeV/u[2], and deuterons and gold ions at ps=200 GeV/u[3]. This paper discusses operational performance statistics of this facility, including Cu- Cu delivered luminosity, availability, calendar time spent in physics stores, and time between physics stores. We summarize the major factors affecting operations efficiency, and characterize machine activities between physics stores.

  14. Heavy ion accelerators at GSI

    Angert, N.

    1984-01-01

    The status of the Unilac heavy ion linear accelerator at GSI, Darmstadt is given. A schematic overall plan view of the Unilac is shown and its systems are described. List of isotopes and intensities accelerated at the Unilac is presented. The experimental possibilities at GSI should be considerably extended by a heavy ion synchrotron (SIS 18) in combination with an experimental storage ring (ESR). A prototype of the rf-accelerating system of the synchrotron has been built and tested. Prototypes for the quadrupole and dipole magnets for the ring are being constructed. The SIS 18 is desigmed for a maximum magnetic rigidity of 18Tm so that neon can be accelerated to 2 GeV/W and uranium to 1 GeV/u. The design allows also the acceleration of protons up to 4.5 GeV. The ESR permits to storage fully stripped uranium ions up to an energy of approximately R50 MeV/u

  15. Semiholography for heavy ion collisions

    Mukhopadhyay, Ayan

    2017-01-01

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

  16. Heavy-ion-spectrometer system

    1982-05-01

    LBL safety policy (Pub 300 Appendix E) states that every research operation with a Class A risk potential (DOE 5484.1) should identify potentially hazardous procedures associated with the operation and develop methods for accomplishing the operation safely without personnel injury or property damage. The rules and practices that management deems to be minimally necessary for the safe operations of the Heavy Ion Spectrometer System (HISS) in the Bevatron Experimental Hall (51B) are set forth in this Operation Safety Procedures

  17. Heavy ion therapy: Bevalac epoch

    Castro, J.R.

    1993-10-01

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

  18. Experiments with stored heavy ions

    Fick, D.; Habs, D.; Jaeschke, E.

    1985-02-01

    The success of newly-developed methods of phase space cooling in proton and antiproton storage rings was sufficient for an examination of whether these methods could also be applied in storage rings for heavy ions. An expansion of these methods to heavy ion beams seems attractive for all sorts of reasons. Recently, this area was extensively discussed in a series of working meetings with the result that heavy ion storage rings are to be built for use in atomic and nuclear physics, with integrated radiation cooling and stochastic cooling, but primarily electron cooling. The current state of research and planning for the storage experiment is described. It is not intended to be a structural specification worked out in detail. The general design of the ring, however, has been established, and experimental details have deliberately been kept flexible, to thereby allow very different sorts of experiments to be conducted. The ring described with a maximum magnetic rigidity of Bp = 1.5 Tm, is designed in quadripartite symmetry. The total circumference is approximately 35 m, and there are four straight sections each 3.5 m long for the electron cooling sections, the experimental equipment, as well as HF system and injection. One of the most desirable properties of the reservoir is the multi-charge mode, which will significantly improve the operation which heavy ion beams, which reverse charge in electron cooling sections, target and residual vacuum. Initial considerations are presented with regard to stochastic and electron cooling. A review of possible classes of experiments is given and the schedule and financing of the project is outlined. 46 refs

  19. Heavy-ion-spectrometer system

    1982-05-01

    LBL safety policy (Pub 300 Appendix E) states that every research operation with a Class A risk potential (DOE 5484.1) should identify potentially hazardous procedures associated with the operation and develop methods for accomplishing the operation safely without personnel injury or property damage. The rules and practices that management deems to be minimally necessary for the safe operations of the Heavy Ion Spectrometer System (HISS) in the Bevatron Experimental Hall (51B) are set forth in this Operation Safety Procedures (OSP).

  20. Radiation from heavy ion collisions

    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.)

  1. Heavy-ion radiation chemistry

    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.)

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

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

    1997-11-21

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

  3. 14. International workshop on nuclear fission physics. Proceedings

    2000-01-01

    The meetings on nuclear fission took place 12-15 October 1998 and was organized by Institute of Physics and Power Engineering. The aim of the workshop was to present and discuss main new both theoretical and experimental results obtained in the area of nuclear fission, dynamical feature, properties of fission fragments and complementary radiation. As usual the program of the workshop was designed to cover a wide range of physical phenomena - from low energy and spontaneous fission to fission of hot rotating nuclei and multifragmentation at intermediate and high energies. Reaction induced by slow and fast neutron, light and heavy ions were discussed [ru

  4. Understanding of the mechanical and structural changes induced by alpha particles and heavy ions in the French simulated nuclear waste glass

    Karakurt, G., E-mail: karakurt_gokhan@yahoo.fr [SUBATECH, UMR 6457CNRS-IN2P3, Ecole des Mines de Nantes, 4 rue Alfred Kastler, 44307 Nantes (France); Abdelouas, A. [SUBATECH, UMR 6457CNRS-IN2P3, Ecole des Mines de Nantes, 4 rue Alfred Kastler, 44307 Nantes (France); Guin, J.-P.; Nivard, M. [Institut de Physique de Rennes, Université de Rennes 1 – UMR 62051 IPR, 263 avenue du Général Leclerc, 35042 Rennes (France); Sauvage, T. [Laboratoire CEMHTI (Conditions Extrêmes et Matériaux: Haute Température et Irradiation), CNRS UPR, 3079 Orléans (France); Paris, M. [Institut des Matériaux Jean ROUXEL, Université de Nantes, UMR 6502 CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 03 (France); Bardeau, J.-F. [Institut des Molécules et Matériaux du Mans, UMR CNRS 6283, avenue Olivier Messiaen, 72085 Le Mans (France)

    2016-07-15

    Borosilicate glasses are considered for the long-term confinement of high-level nuclear wastes. External irradiations with 1 MeV He{sup +} ions and 7 MeV Au{sup 5+} ions were performed to simulate effects produced by alpha particles and by recoil nuclei in the simulated SON68 nuclear waste glass. To better understand the structural modifications, irradiations were also carried out on a 6-oxides borosilicate glass, a simplified version of the SON68 glass (ISG glass). The mechanical and macroscopic properties of the glasses were studied as function of the deposited electronic and nuclear energies. Alpha particles and gold ions induced a volume change up to −0.7% and −2.7%, respectively, depending on the glass composition. Nano-indentations tests were used to determine the mechanical properties of the irradiated glasses. A decrease of about −22% to −38% of the hardness and a decrease of the reduced Young's modulus by −8% were measured after irradiations. The evolution of the glass structure was studied by Raman spectroscopy, and also {sup 11}B and {sup 27}Al Nuclear Magnetic Resonance (MAS-NMR) on a 20 MeV Kr irradiated ISG glass powder. A decrease of the silica network connectivity after irradiation with alpha particles and gold ions is deduced from the structural changes observations. NMR spectra revealed a partial conversion of BO{sub 4} to BO{sub 3} units but also a formation of AlO{sub 5} and AlO{sub 6} species after irradiation with Kr ions. The relationships between the mechanical and structural changes are also discussed. - Highlights: • Mechanical and structural properties of two borosilicate glass compositions irradiated with alpha particles and heavy ions were investigated. • Both kinds of particles induced a decrease of the hardness, reduced Young's modulus and density. • Electronic and nuclear interactions are responsible for the changes observed. • The evolution of the mechanical properties under irradiation is linked

  5. Understanding of the mechanical and structural changes induced by alpha particles and heavy ions in the French simulated nuclear waste glass

    Karakurt, G.; Abdelouas, A.; Guin, J.-P.; Nivard, M.; Sauvage, T.; Paris, M.; Bardeau, J.-F.

    2016-01-01

    Borosilicate glasses are considered for the long-term confinement of high-level nuclear wastes. External irradiations with 1 MeV He + ions and 7 MeV Au 5+ ions were performed to simulate effects produced by alpha particles and by recoil nuclei in the simulated SON68 nuclear waste glass. To better understand the structural modifications, irradiations were also carried out on a 6-oxides borosilicate glass, a simplified version of the SON68 glass (ISG glass). The mechanical and macroscopic properties of the glasses were studied as function of the deposited electronic and nuclear energies. Alpha particles and gold ions induced a volume change up to −0.7% and −2.7%, respectively, depending on the glass composition. Nano-indentations tests were used to determine the mechanical properties of the irradiated glasses. A decrease of about −22% to −38% of the hardness and a decrease of the reduced Young's modulus by −8% were measured after irradiations. The evolution of the glass structure was studied by Raman spectroscopy, and also 11 B and 27 Al Nuclear Magnetic Resonance (MAS-NMR) on a 20 MeV Kr irradiated ISG glass powder. A decrease of the silica network connectivity after irradiation with alpha particles and gold ions is deduced from the structural changes observations. NMR spectra revealed a partial conversion of BO 4 to BO 3 units but also a formation of AlO 5 and AlO 6 species after irradiation with Kr ions. The relationships between the mechanical and structural changes are also discussed. - Highlights: • Mechanical and structural properties of two borosilicate glass compositions irradiated with alpha particles and heavy ions were investigated. • Both kinds of particles induced a decrease of the hardness, reduced Young's modulus and density. • Electronic and nuclear interactions are responsible for the changes observed. • The evolution of the mechanical properties under irradiation is linked to the changes occured in the

  6. Recent applications of the Boltzmann master equation to heavy ion precompound decay phenomena

    Blann, M.; Remington, B.A.

    1988-06-01

    The Boltzmann master equation (BME) is described and used as a tool to interpret preequilibrium neutron emission from heavy ion collisions gated on evaporation residue or fission fragments. The same approach is used to interpret neutron spectra gated on deep inelastic and quasi-elastic heavy ion collisions. Less successful applications of BME to proton inclusive data with 40 MeV/u incident 12 C ions are presented, and improvements required in the exciton injection term are discussed

  7. Progress Toward Heavy Ion IFE

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

    2002-01-01

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

  8. Beam modulation for heavy ion radiotherapy

    Kanai, T.; Minohara, S.; Sudou, M.

    1993-01-01

    The first clinical trial of heavy ion radiation therapy is scheduled in 1994 by using the heavy ion medical accelerator in Chiba (HIMAC). In order to start the clinical trial, first, it is necessary to know the physical characteristics of high energy heavy ions in human bodies, for example, dose and linear energy transfer (LET) distribution. Also the knowledge on the biological effectiveness of heavy ions is required. Based on these biophysical properties of heavy ions, monoenergetic heavy ion beam should be modulated so as to make the spread Bragg peak suitable to heavy ion radiation therapy. In order to establish a methodology to obtain the most effective spread Bragg peak for heavy ion radiation therapy, a heavy ion irradiation port at the RIKEN ring cyclotron facility was constructed. By using a 135 MeV/u carbon beam, the biophysical properties of the heavy ions were investigated, and a range modulator was designed to have uniform biological response in the spread Bragg peak. The physical and biological rationality of the spread Bragg peak were investigated. The dose, LET and biological effect of a monoenergetic heavy ion beam, the design of the range modulator, and the distributions of LET and biological dose for the spread Bragg peak are reported. (K.I.)

  9. Targeted heavy-ion microbeam irradiation of the embryo but not yolk in the diapause-terminated egg of the silkworm, bombyx mori, induces the somatic mutation

    Furusawa, Toshiharu; Fukamoto, Kana; Sakashita, Tetsuya; Funayama, Tomoo; Kobayashi, Yasuhiko; Kakizaki, Takehiko; Wada, Seiichi; Hamada, Nobuyuki; Suzuki, Hiromi; Ishioka, Noriaki; Nagaoka, Shunji

    2009-01-01

    Using heavy-ion microbeam, we report target irradiation of selected compartments within the diapause-terminated egg and its mutational consequences in the silkworm, Bombyx mori. On one hand, carbon-ion exposure of embryo to 0.5-6 Gy increased the somatic mutation frequency, suggesting targeted radiation effects. On the other, such increases were not observed when yolk was targeted, suggesting a lack of nontargeted bystander effect. (author)

  10. Heavy-ion induced desorption of a TiZrV coated vacuum chamber bombarded with 5 MeV/u Ar8+ beam at grazing incidence

    Hedlund, E.; Malyshev, O. B.; Westerberg, L.; Krasnov, A.; Semenov, A. S.; Leandersson, M.; Zajec, B.; Kollmus, H.; Bellachioma, M. C.; Bender, M.; Kraemer, A.; Reich-Sprenger, H.

    2009-01-01

    TiZrV nonevaporable getter (NEG) coated vacuum chambers is a new vacuum technology which is already used in many particle accelerators worldwide. This coating is also of interest for heavy-ion accelerator vacuum chambers. Heavy-ion desorption yields from an activated as well as a CO saturated NEG coated tube have been measured with 5 MeV/u Ar 8+ beam. The sticking probability of the NEG film was obtained by using the partial pressure ratios on two sides of the NEG coated tube. These ratios were compared to results of modeling of the experimental setup with test particle Monte Carlo and angular coefficient methods. The partial pressures inside the saturated NEG coated tube bombarded with heavy ions were up to 20 times larger than those inside the activated one. However, the partial pressure of methane remained the same. The value of the total desorption yield from the activated NEG coated tube is 2600 molecules/ion. The desorption yields after saturation for CH 4 , H 2 , and CO 2 were found to be very close to the yields measured after the activation, while CO increased by up to a factor of 5. The total desorption yield for the saturated tube is up to 7000 molecules/ion. The large value of the desorption yield of the activated NEG coated tube, an order of magnitude higher than the desorption yield from a stainless steel tube at normal incident angle, could be explained by the grazing incident angle

  11. Study of a High-Yield Cellulase System Created by Heavy-Ion Irradiation-Induced Mutagenesis of Aspergillus niger and Mixed Fermentation with Trichoderma reesei

    Chen, Ji-Hong; Li, Wen-Jian; Liu, Jing; Hu, Wei; Xiao, Guo-Qing; Dong, Miao-Yin; Wang, Yu-Chen

    2015-01-01

    The aim of this study was to evaluate and validate the efficiency of 12C6+ irradiation of Aspergillus niger (A. niger) or mutagenesis via mixed Trichoderma viride (T. viride) culturing as well as a liquid cultivation method for cellulase production via mixed Trichoderma reesei (T. reesei) and A. niger culture fermentation. The first mutagenesis approach was employed to optimize yield from a cellulase-producing strain via heavy-ion mutagenesis and high-throughput screening, and the second was to effectively achieve enzymatic hydrolysis of cellulase from a mixed culture of mutant T. viride and A. niger. We found that 12C6+-ion irradiation induced changes in cellulase biosynthesis in A. niger but had no effect on the time course of the synthesis. It is notable that the exoglucanases (CBH) activities of A. niger strains H11-1 and H differed (6.71 U/mL vs. 6.01 U/mL) and were significantly higher than that of A. niger mutant H3-1. Compared with strain H, the filter paper assay (FPA), endoglucanase (EG) and β-glucosidase (BGL) activities of mutant strain H11-1 were increased by 250.26%, 30.26% and 34.91%, respectively. A mixed culture system was successfully optimized, and the best ratio of T. reesei to A. niger was 5:1 for 96 h with simultaneous inoculation. The BGL activity of the mixed culture increased after 72 h. At 96 h, the FPA and BGL activities of the mixed culture were 689.00 and 797.15 U/mL, respectively, significantly higher than those of monocultures, which were 408.70 and 646.98 U/mL for T. reesei and 447.29 and 658.89 U/mL for A. niger, respectively. The EG activity of the mixed culture was 2342.81 U/mL, a value that was significantly higher than that of monocultures at 2206.57 U/mL for T. reesei and 1727.62 U/mL for A. niger. In summary, cellulose production and hydrolysis yields were significantly enhanced by the proposed combination scheme. PMID:26656155

  12. Study of a High-Yield Cellulase System Created by Heavy-Ion Irradiation-Induced Mutagenesis of Aspergillus niger and Mixed Fermentation with Trichoderma reesei.

    Shu-Yang Wang

    Full Text Available The aim of this study was to evaluate and validate the efficiency of 12C6+ irradiation of Aspergillus niger (A. niger or mutagenesis via mixed Trichoderma viride (T. viride culturing as well as a liquid cultivation method for cellulase production via mixed Trichoderma reesei (T. reesei and A. niger culture fermentation. The first mutagenesis approach was employed to optimize yield from a cellulase-producing strain via heavy-ion mutagenesis and high-throughput screening, and the second was to effectively achieve enzymatic hydrolysis of cellulase from a mixed culture of mutant T. viride and A. niger. We found that 12C6+-ion irradiation induced changes in cellulase biosynthesis in A. niger but had no effect on the time course of the synthesis. It is notable that the exoglucanases (CBH activities of A. niger strains H11-1 and H differed (6.71 U/mL vs. 6.01 U/mL and were significantly higher than that of A. niger mutant H3-1. Compared with strain H, the filter paper assay (FPA, endoglucanase (EG and β-glucosidase (BGL activities of mutant strain H11-1 were increased by 250.26%, 30.26% and 34.91%, respectively. A mixed culture system was successfully optimized, and the best ratio of T. reesei to A. niger was 5:1 for 96 h with simultaneous inoculation. The BGL activity of the mixed culture increased after 72 h. At 96 h, the FPA and BGL activities of the mixed culture were 689.00 and 797.15 U/mL, respectively, significantly higher than those of monocultures, which were 408.70 and 646.98 U/mL for T. reesei and 447.29 and 658.89 U/mL for A. niger, respectively. The EG activity of the mixed culture was 2342.81 U/mL, a value that was significantly higher than that of monocultures at 2206.57 U/mL for T. reesei and 1727.62 U/mL for A. niger. In summary, cellulose production and hydrolysis yields were significantly enhanced by the proposed combination scheme.

  13. Direct-driven target implosion in heavy ion fusion

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

    2016-01-01

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

  14. Proteomics analysis of ram sperm by heavy ion radiation

    He Yuxuan; Li Hongyan; Zhang Hong

    2013-01-01

    The objective of this study was to investigate the proteome changes induced by heavy ion radiation using irradiated ram sperm by a two-dimensional electrophoresis (2-DE) analysis. The 2D gels were stained with Coomassie Brilliant Blue. Differentially expressed proteins were detected by PDQuest 8.0 software and subjected to ion trap mass spectrometer equipped with a surveyor HPLC system, and differential protein spots were identified. Results showed there are five differential protein spots in irradiated sperm gels, four up-regulated protein spots and one spot missed. The differentially expressed protein spots were identified to be two up-regulated proteins including enolase, and enolase 1. It was concluded there was proteome changes induced by heavy ion radiation in ram sperm, which may be useful to clarify the physiology state of ram sperm in heavy ion radiation and provide a theoretical basis for radiation ram breeding. (authors)

  15. Heavy ion irradiation of astrophysical ice analogs

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

    2009-01-01

    Icy grain mantles consist of small molecules containing hydrogen, carbon, oxygen and nitrogen atoms (e.g. H 2 O, GO, CO 2 , NH 3 ). Such ices, present in different astrophysical environments (giant planets satellites, comets, dense clouds, and protoplanetary disks), are subjected to irradiation of different energetic particles: UV radiation, ion bombardment (solar and stellar wind as well as galactic cosmic rays), and secondary electrons due to cosmic ray ionization of H 2 . The interaction of these particles with astrophysical ice analogs has been the object of research over the last decades. However, there is a lack of information on the effects induced by the heavy ion component of cosmic rays in the electronic energy loss regime. The aim of the present work is to simulate of the astrophysical environment where ice mantles are exposed to the heavy ion cosmic ray irradiation. Sample ice films at 13 K were irradiated by nickel ions with energies in the 1-10 MeV/u range and analyzed by means of FTIR spectrometry. Nickel ions were used because their energy deposition is similar to that deposited by iron ions, which are particularly abundant cosmic rays amongst the heaviest ones. In this work the effects caused by nickel ions on condensed gases are studied (destruction and production of molecules as well as associated cross sections, sputtering yields) and compared with respective values for light ions and UV photons. (authors)

  16. Differences in heavy-ion-induced DNA double-strand breaks in a mouse DNA repair-deficient mutant cell line (SL3-147) before and after chromatin proteolysis

    Murakami, Masahiro; Eguchi-Kasai, Kiyomi; Sato, Koki; Minohara, Shinichi; Kanai, Tatsuaki; Yatagai, Fumio.

    1995-01-01

    DNA double-strand breaks induced by X- or neon beam-irradiation in a DNA double-strand break-repair-deficient mutant cell line (SL3-147) were examined. The increase in the number of DNA double-strand breaks was dose-depend after irradiation with X-rays and neon beams and was enhanced by chromatin-proteolysis treatment before irradiation. These results suggest that the induction of DNA double-strand breaks by ionizing radiation, including heavy-ions, is influenced by the chromatin structure. (author)

  17. Superconducting heavy-ion linacs

    Bollinger, L.M.

    1977-01-01

    A summary is given of plans developed by four different groups for the construction of small superconducting linacs to boost the energy of heavy ions from existing tandem electrostatic accelerators. The projects considered are the linac under construction at Argonne and the design efforts at Karlsruhe, at Stanford, and by a Cal Tech-Stony Brook collaboration. The intended uses of the accelerator systems are stated. Beam dynamics of linacs formed of short independently-phased resonators are reviewed, and the implications for performance are discussed. The main parameters of the four linacs are compared, and a brief analysis of accelerating structures is given

  18. arXiv Heavy ions at the Future Circular Collider

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

    2017-06-22

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

  19. Hydrodynamic motion of a heavy-ion-beam-heated plasma

    Jacoby, J.; Hoffmann, D.H.H.; Mueller, R.W.; Mahrt-Olt, K.; Arnold, R.C.; Schneider, V.; Maruhn, J.

    1990-01-01

    The first experimental study is reported of a plasma produced by a heavy-ion beam. Relevant parameters for heating with heavy ions are described, temperature and density of the plasma are determined, and the hydrodynamic motion in the target induced by the beam is studied. The measured temperature and the free-electron density are compared with a two-dimensional hydrodynamic-model calculation. In accordance with the model, a radial rarefaction wave reaching the center of the target was observed and the penetration velocity of the ion beam into the xenon-gas target was measured

  20. Delta-electron emission in fast heavy ion atom collisions

    Schmidt-Boecking, H.; Ramm, U.; Berg, H.; Kelbch, C.; Feng Jiazhen; Hagmann, S.; Kraft, G.; Ullrich, J.

    1991-01-01

    The δ-electron emission processes occuring in fast heavy ion atom collisons are explained qualitatively. The different spectral structures of electron emission arising from either the target or the projectile are explained in terms of simple models of the kinetics of momentum transfer induced by the COULOMB forces. In collisions of very heavy ions with matter, high nuclear COULOMB forces are created. These forces lead to a strong polarization of the electronic states of the participated electrons. The effects of this polarization are discussed. (orig.)

  1. Heavy Ion Current Transients in SiGe HBTs

    Pellish, Jonathan A.; Reed, Robert A.; Vizkelethy, Gyorgy; McMorrow, Dale; Ferlet-Cavrois, Veronique; Baggio, Jacques; Paillet, Philipe; Duhanel, Olivier; Phillips, Stanley D.; Sutton, Akil K.; hide

    2009-01-01

    Time-resolved ion beam induced charge reveals heavy ion response of IBM 5AM SiGe HBT: a) Position correlation[ b) Unique response for different bias schemes; c) Similarities to TPA pulsed-laser data. Heavy ion broad-beam transients provide more realistic device response: a) Feedback using microbeam data; b) Overcome issues of LET and ion range with microbeam. Both micro- and broad-beam data sets yield valuable input for TCAD simulations. Uncover detailed mechanisms for SiGe HBTs and other devices fabricated on lightly-doped substrates.

  2. Combination of chemotherapy and heavy-ion particle therapy for pancreas cancer

    Yamada, Shigeru; Ando, Koichi

    2003-01-01

    The purpose of this study is to investigate the combination of chemotherapy and heavy-ion particle therapy for pancreas cancer. We measured surviving fractions in four culture pancreas cancer cells. The cell killing of heavy-ion irradiation is more effective compared to that of X ray irradiation. Gemcitabine induced radiosensitization for pancreas cancer cells. (author)

  3. Combination of chemotherapy and heavy-ion particle therapy for pancreas cancer

    Yamada, Shigeru; Ando, Koichi

    2004-01-01

    The purpose of this study is to investigate the combination of chemotherapy and heavy-ion particle therapy for pancreas cancer. We measured surviving fractions in four culture pancreas cancer cells. The cell killing of heavy-ion irradiation is more effective compared to that of X ray irradiation. Gemcitabine induced radiosensitization for pancreas cancer cells. (author)

  4. Summary of the relativistic heavy ion sessions

    Harris, J.W.

    1988-01-01

    The topics covered in the Relativistic Heavy Ion Sessions span four orders of magnitude in energy in the laboratory and a few more in theory. In the two years since the last Intersections conference, experiments in the field of very high energy heavy ion research have begun at CERN and Brookhaven. The prime motivation for these experiments is the possibility of forming quark matter. This paper is a review of the topics covered in the Relativistic Heavy Ion Sessions

  5. International cooperation in heavy-ion research

    Tobias, C.A.

    1980-01-01

    The rapidly growing research applications of heavy ions in basic biology and medicine have stimulated interest in this field in many countries. LBL, with its unique facilities and its scientific programs, is the focal point of interest. Plans are underway in several countries, including France, Japan, West Germany, and Canada, to build heavy-ion facilities, and to collaborate with our staff at LBL in heavy-ion research in physics, biology, and medicine

  6. Analyzing the Influence of the Angles of Incidence and Rotation on MBU Events Induced by Low LET Heavy Ions in a 28-nm SRAM-Based FPGA

    Tonfat, Jorge; Kastensmidt, Fernanda Lima; Artola, Laurent; Hubert, Guillaume; Medina, Nilberto H.; Added, Nemitala; Aguiar, Vitor A. P.; Aguirre, Fernando; Macchione, Eduardo L. A.; Silveira, Marcilei A. G.

    2017-08-01

    This paper shows the impact of low linear energy transfer heavy ions on the reliability of 28-nm Bulk static random access memory (RAM) cells from Artix-7 field-programmable gate array. Irradiation tests on the ground showed significant differences in the multiple bit upset cross section of configuration RAM and block RAM memory cells under various angles of incidence and rotation of the device. Experimental data are analyzed at transistor level by using the single-event effect prediction tool called multiscale single-event phenomenon prediction platform coupled with SPICE simulations.

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

    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.

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

    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.

  9. Heavy Ion Physics at CMS

    Veres, Gabor

    2017-01-01

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

  10. Probing the nuclear structure with heavy-ion reactions

    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

  11. Fission dynamics in the proton induced fission of heavy nuclei

    Rubchenya, V.A. E-mail: rubchen@phys.jyu.fi; Trzaska, W.H.; Itkis, I.M.; Itkis, M.G.; Kliman, J.; Kniajeva, G.N.; Kondratiev, N.A.; Kozulin, E.M.; Krupa, L.; Pokrovski, I.V.; Voskressenski, V.M.; Hanappe, F.; Materna, T.; Dorvaux, O.; Stuttge, L.; Chubarian, G.; Khlebnikov, S.V.; Vakhtin, D.N.; Lyapin, V.G

    2004-04-05

    Multi-parameter correlation study of the reaction {sup 242}Pu(p, f) at E{sub p} 13, 20 and 55 MeV has been carried out. Fission fragment mass and kinetic energy distributions and the double differential neutron spectra have been measured. It was observed that the two-humped shape of mass distributions prevailed up to highest proton energy. Manifestation of the nuclear shell Z 28 near fragment mass A{sub fr} = 70 has been detected. The experimental results were analyzed in the framework of a time-dependent statistical model with inclusion of nuclear friction effects in the fission process. The multi-parameter correlation study of the reaction.

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

    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...

  13. SPORT: A new sub-nanosecond time-resolved instrument to study swift heavy ion-beam induced luminescence - Application to luminescence degradation of a fast plastic scintillator

    Gardés, E.; Balanzat, E.; Ban-d'Etat, B.; Cassimi, A.; Durantel, F.; Grygiel, C.; Madi, T.; Monnet, I.; Ramillon, J.-M.; Ropars, F.; Lebius, H.

    2013-02-01

    We developed a new sub-nanosecond time-resolved instrument to study the dynamics of UV-visible luminescence under high stopping power heavy ion irradiation. We applied our instrument, called SPORT, on a fast plastic scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean electronic stopping power of 2.6 MeV/μm. As a consequence of increasing permanent radiation damages with increasing ion fluence, our investigations reveal a degradation of scintillation intensity together with, thanks to the time-resolved measurement, a decrease in the decay constant of the scintillator. This combination indicates that luminescence degradation processes by both dynamic and static quenching, the latter mechanism being predominant. Under such high density excitation, the scintillation deterioration of BC-400 is significantly enhanced compared to that observed in previous investigations, mainly performed using light ions. The observed non-linear behaviour implies that the dose at which luminescence starts deteriorating is not independent on particles' stopping power, thus illustrating that the radiation hardness of plastic scintillators can be strongly weakened under high excitation density in heavy ion environments.

  14. Independent fission yields of Rb and Cs from thermal-neutron-induced fission of 239Pu

    Balestrini, S.J.; Forman, L.

    1975-01-01

    The relative independent fission yields of Rb and Cs from thermal-neutron-induced fission of 239 Pu have been measured on line using a mass spectrograph and thermalized neutrons from a burst reactor. Independent yields were derived by normalizing the measurements to products of chain yields and fractional independent yields, estimating the latter from measured cumulative yields of Kr and Xe. Comparing the independent yields with those from 238 U fission, the 239 Pu results show shifts in isotopic yield distribution toward lower mass for both Rb and Cs and also toward the production of more Cs and less Rb when 239 Pu is fissioned

  15. Prospective utilization of accelerated heavy ions in basic and applied research

    Flerov, G.; Oganesyan, Yu.

    1982-01-01

    Some important and interesting trends of heavy ion physics are briefly presented, such as giant processes which are characterized by fundamental restructuring of nuclear systems containing hundreds of nucleons, the mechanism of heavy nuclei interaction, the study of nuclear matter compression, the study of the specificity of heating and thermal conductivity of nuclear matter, the study of heavy ion/nucleus interactions at energies of 200 to 300 MeV/nucleon when the meson degree of freedom becomes manifest, the possibility of the production of ions with a large excess or deficiency of neutrons, new possibilities for determining the fission barrier, the critical verification of fundamental physical concepts of quantum electrodynamics and other possibilities of using accelerated heavy ions. The significance of heavy ion physics for the development of acceleration technologies is also described. (B.S.)

  16. Asymmetry in ternary fission induced by polarized neutrons and fission mechanism

    Bunakov, V.E.; Gennenvajn, F.; Dzhessinger, P.; Mutterer, M.; Petrov, G.A.

    2003-01-01

    The results of measuring the P-odd, P-even (right-left) and T-odd asymmetries of the charged particles emission in the double and ternary fission, induced by the polarized neutrons, are considered. It is shown, what kind of information on the mechanism of the ternary nuclear fission may be obtained from the theoretical analysis of these data [ru

  17. Determination of the fission barrier height in fission of heavy radioactive beams induced by the (d,p)-transfer

    A theoretical framework is described, allowing to determine the fission barrier height using the observed cross sections of fission induced by the (d,p)-transfer with accuracy, which is not achievable in another type of low-energy fission of neutron-deficient nuclei, the $\\beta$-delayed fission. The primary goal is to directly determine the fission barrier height of proton-rich fissile nuclei, preferably using the radio-active beams of isotopes of odd elements, and thus confirm or exclude the low values of fission barrier heights, typically extracted using statistical calculations in the compound nucleus reactions at higher excitation energies. Calculated fission cross sections in transfer reactions of the radioactive beams show sufficient sensitivity to fission barrier height. In the probable case that fission rates will be high enough, mass asymmetry of fission fragments can be determined. Results will be relevant for nuclear astrophysics and for production of super-heavy nuclei. Transfer induced fission of...

  18. QCD in heavy ion collisions

    Iancu, Edmond [IPhT, Saclay (France)

    2014-07-01

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

  19. QCD in heavy ion collisions

    Iancu, Edmond

    2014-01-01

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

  20. Heavy ion physics at CERN

    Vesztergombi, G.

    1991-01-01

    A summary of the present status and future plans for heavy ion experiments at CERN-SPS and CERN-LHC accelerators is given. The planned three phases give possibilities to study the properties of the quark-gluon-plasma (QGP). At the present stage the feasibility of high energy ion-ion experiments with their very abundant secondary hadron production, shows that there is a chance to obtain high densities, and to look for the onset of new, collective phenomena. In a second phase, there should be a chance to obtain more conclusive evidence for the onset of quark deconfinement. In the third stage, the average energy densities rise above the deconfinement threshold, so that a study of the properties of QGP should become possible. (G.P.)

  1. Progress in Heavy Ion Fusion

    Herrmannsfeldt, W.B.

    1988-09-01

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

  2. RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT

    Friedlander, Erwin M.; Heckman, Harry H.

    1982-04-01

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

  3. Medical heavy ion accelerator proposals

    Gough, R.A.

    1985-05-01

    For several decades, accelerators designed primarily for research in nuclear and high energy physics have been adapted for biomedical research including radiotherapeutic treatment of human diseases such as pituitary disorders, cancer, and more recently, arteriovascular malformations. The particles used in these treatments include pions, protons and heavier ions such as carbon, neon, silicon and argon. Maximum beam energies must be available to penetrate into an equivalent of about 30 cm of water, requiring treatment beams of 250 to 1000 MeV/nucleon. Certain special treatments of superficial melanoma, however, require that beam energies as low as 70 MeV/nucleon also be available. Intensities must be adequate to complete a 100 rad treatment fraction in about 1 minute. For most heavy ion treatments, this corresponds to 10 7 -10 9 ions/second at the patient. Because this research is best conducted in a dedicated, hospital-based facility, and because of the clinical need for ultra-high reliability, the construction of new and dedicated facilities has been proposed. Heavy ion accelerators can provide a variety of ions and energies, permitting treatment plans that exploit the properties of the ion best suited to each individual treatment, and that employ radioactive beams (such as 11 C and 19 Ne) to precisely confirm the dose localization. The favored technical approach in these proposals utilizes a conventional, strong-focusing synchrotron capable of fast switching between ions and energies, and servicing multiple treatment rooms. Specialized techniques for shaping the dose to conform to irregularly-shaped target volumes, while simultaneously sparing surrounding, healthy tissue and critical structures, are employed in each treatment room, together with the sophisticated dosimetry necessary for verification, monitoring, and patient safety. 3 refs., 8 figs

  4. Relativistic heavy ion research at Berkeley

    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).

  5. Highlights of the heavy ion fusion symposium

    Keefe, D.

    1986-01-01

    The current status and prospects for inertial confinement fusion based on the use of intense beams of heavy ions will be described in the light of results presented at the International Symposium on Heavy Ion Fusion, (Washington, DC, May 27-29, 1986)

  6. Highlights of the heavy ion fusion symposium

    Keefe, D.

    1986-07-01

    The current status and prospects for inertial confinement fusion based on the use of intense beams of heavy ions will be described in the light of results presented at the International Symposium on Heavy Ion Fusion, (Washington, DC, May 27-29, 1986)

  7. Detector issues for relativistic heavy ion experimentation

    Gordon, H.

    1986-04-01

    Several aspects of experiments using relativistic heavy ion beams are discussed. The problems that the current generation of light ion experiments would face in using gold beams are noted. A brief review of colliding beam experiments for heavy ion beams is contrasted with requirements for SSC detectors. 11 refs., 13 figs

  8. Heavy ion reactions at high energies

    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

  9. 7th high energy heavy ion study

    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)

  10. Searching for Jets in Heavy Ion Collisions

    Salur, Sevil

    2008-01-01

    Jet quenching measurements using leading particles and their correlations suffer from known biases, which can be removed via direct reconstruction of jets in central heavy ion collisions. In this talk, we discuss several modern jet reconstruction algorithms and background subtraction techniques that are appropriate to heavy ion collisions

  11. Beam losses in heavy ion drivers

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

    2002-01-01

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

  12. Measurement of prompt fission gamma-ray spectra in fast neutron-induced fission

    Laborie, J.M.; Belier, G.; Taieb, J.

    2012-01-01

    Knowledge of prompt fission gamma-ray emission has been of major interest in reactor physics for a few years. Since very few experimental spectra were ever published until now, new measurements would be also valuable to improve our understanding of the fission process. An experimental method is currently being developed to measure the prompt fission gamma-ray spectrum from some tens keV up to 10 MeV at least. The mean multiplicity and total energy could be deduced. In this method, the gamma-rays are measured with a bismuth germanate (BGO) detector which has the advantage to present a high P/T ratio and a high efficiency compared to other gamma-ray detectors. The prompt fission neutrons are rejected by the time of flight technique between the BGO detector and a fission trigger given by a fission chamber or a scintillating active target. Energy and efficiency calibration of the BGO detector were carried out up to 10.76 MeV by means of the Al-27(p, gamma) reaction. First prompt fission gamma-ray spectrum measurements performed for the spontaneous fission of Cf-252 and for 1.7 and 15.6 MeV neutron-induced fission of U-238 at the CEA, DAM, DIF Van de Graaff accelerator, will be presented. (authors)

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

    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

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

    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.

  15. Heavy ion-induced lesions in DNA: A theoretical model for the initial induction of DNA strand breaks and chromatin breaks

    Schmidt, J.B.

    1993-01-01

    A theoretical model has been developed and used to calculate yields and spatial distributions of DNA strand breaks resulting from the interactions of heavy ions with chromatin in aqueous systems. The three dimensional spatial distribution of ionizing events has been modeled for charged particles as a function of charge and velocity. Chromatin has been modeled as a 30 nm diameter solenoid of nucleosomal DNA. The Monte Carlo methods used by Chatterjee et al. have been applied to DNA in a chromatin conformation. Refinements to their methods include: a combined treatment of primary and low energy (<2 keV) secondary electron interactions, an improved low energy delta ray model, and the combined simulation of direct energy deposition on the DNA and attack by diffusing hydroxyl radicals. Individual particle tracks are treated independently, which is assumed to be applicable to low fluence irradiations in which multiple particle effects are negligible. Single strand break cross section open-quotes hooksclose quotes seen in experiments at very high LET appear to be due to the collapsing radial extent of the track, as predicted in the open-quotes deep sieveclose quotes hypothesis proposed by Tobias et al. Spatial distributions of lesions produced by particles have been found to depend on chromatin structure. In the future, heavy ions may be used as a tool to probe the organization of DNA in chromatin. A Neyman A-binomial variation of the open-quotes cluster modelclose quotes for the distribution of chromatin breaks per irradiated cell has been theoretically tested. The model includes a treatment of the chromatin fragment detection technique's resolution, which places a limitation on the minimum size of fragments which can be detected. The model appears to fit some of the experimental data reasonably well. However, further experimental and theoretical refinements are desirable

  16. Heavy ion program at BNL: AGS, RHIC [Relativistic Heavy Ion Collider

    Barton, D.S.

    1987-01-01

    With the recent commissioning of fixed target, heavy ion physics at the AGS, Brookhaven National Laboratory (BNL) has embarked on a long range program in support of relativistic heavy ion research. Acceleration of low mass heavy ions (up to sulfur) to an energy of about 14.5 GeV/nucleon is possible with the direct connection of the BNL Tandem Van de Graaff and AGS accelerators. When completed, the new booster accelerator will provide heavy ions over the full mass range for injection and subsequent acceleration in the AGS. BNL is now engaged in an active R and D program directed toward the proposed Relativistic Heavy Ion Collider (RHIC). The results of the first operation of the low mass heavy ion program will be reviewed, and future expectations discussed. The expected performance for the heavy ion operation of the booster will be described and finally, the current status and outlook for the RHIC facility will be presented

  17. Evidence for heavy ion emission of 230U

    Pan Qiangyan; Yang Weifan; Yuan Shuanggui; Li Zongwei; Ma Taotao; Guo Junsheng; Liu Mingyi; Liu Hongye; Xu Shuwei; Gan Zaiguo; Kong Dengming; Qiao Jimin; Luo Zihua; Zhang Mutian; Wang Shuhong

    1999-01-01

    Radioisotope of 230 Pa was synthesized by proton irradiation of ThO 2 powder targets with thickness of about 2g/cm 2 . Pure 230 Pa was extracted and deep purified from thorium and fission products by the radiochemical method. Thin 230 Pa→ 230 U sources were prepared for measuring the cluster decay of 230 U. Two cases of decay via heavy ion emission, which were most probably for the neon decays of 230 U, were detected by using solid-state track registration detectors. The preliminary branching ratio relative to α-decay comes out to be (1.3 +- 0.8) x 10 -14

  18. Equilibrium fission model calculations

    Beckerman, M.; Blann, M.

    1976-01-01

    In order to aid in understanding the systematics of heavy ion fission and fission-like reactions in terms of the target-projectile system, bombarding energy and angular momentum, fission widths are calculated using an angular momentum dependent extension of the Bohr-Wheeler theory and particle emission widths using angular momentum coupling

  19. Experimental approaches to heavy ion fusion

    Obayashi, H.; Fujii-e, Y.; Yamaki, T.

    1986-01-01

    As a feasibility study on heavy-ion-beam induced inertial fusion (HIF) approach, a conceptual plant design called HIBLIC-I has been worked out since 1982. The characteristic features of this design are summarized. To experimentally confirm them and prove them at least in principle, considerations are made on possible experimental programs to give substantial information on these critical phenomena. In HIBLIC-I, an accelerator complex is adopted as driver system to provide 6 beams of 208 Pb +1 ions at 15 GeV, which will be simultaneously focussed on a single shell, three layered target. The target is designed to give an energy gain of 100, so that the total beam energy of 4 MJ with 160 TW power may release 400 MJ fusion energy. A reactor chamber is cylindrical with double-walled structure made of HT-9. There are three layers of liquid Li flow inside the reactor. The innermost layer forms a Li curtain which is effective to recover the residual cavity pressure. A thick upward flow serves as coolant and tritium breeder. Tritium will be recovered by yttrium gettering system. A driver system is operated at the repetition rate of 10 Hz and supplies beams for 10 reactor chambers. Then the plant yield of fusion power becomes 4000 MWt, corresponding a net electric output of 1.5 GW. Experimental programs related to HIBLIC-I is described and discussed, including those for heavy-ion-beam experiments and proposals for lithium curtain by electron beam to clarify the key phenomena in HIBLIC-I cavity. (Nogami, K.)

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

    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

  1. [Heavy ion nuclear physics research

    Liu, X.T.; Petitt, G.A.; Zhang, Ziyang.

    1992-01-01

    We have continued working on essentially the same projects during the period 1991--92 as reported on in our previous progress report. That is, R ampersand D work on a dimuon detector for RHIC and work with the group at LANL on neutron induced fission measurements using the white neutron source at LAMPF. Our work has included participation in the RD-10 experiment at the AGS to study calorimeter/absorber optimization for a RHIC experiment. We have actively participated in the setup of the apparatus, the data-taking and the subsequent data analysis. We have used the Vax computer system in our department and the eight-processor Silicon Graphics system in the GSU computer center for most of the data analysis work. We have also continued our work on Monte Carlo simulations of various configurations of absorber/calorimeters for detection of electrons and muons in RHIC experiments. We have made increasing use of the Silicon Graphics computer for our work. Each processor has approximately the same power as a Decstation 5000 and we usually have essentially exclusive simultaneous use of three of the processors. We have installed GEANT 315 and PAW on this system. Since our Vaxstation was purchased before DECWINDOWS was a standard part of the Vax software we have been unable to use the Silicon Graphics computer for doing graphics with PAW and GEANT. We are attempting to solve this problem by installing X-Windows software on our 386SX system which is connected to the campus network. Our work at Los Alamos has consisted of participation in the LAMPF run during the summer of 1991 including constructing and setting up two new neutron detectors for the experiment. These projects are discussed in further detail in this paper

  2. Heavy ion interactions of deformed nuclei. Progress report, May 1, 1984-December 31, 1984

    Oberacker, V.E.

    1984-11-01

    This progress report describes the main topics that were investigated during the reporting period: (a) a new microscopic approach to the calculation of heavy ion interaction potentials; (b) the dynamical orientation of deformed heavy nuclei near the distance of closest approach; and (c) the theory of Coulomb fission (project finished in Sept.)

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

    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

  4. Modified-surface-energy methods for deriving heavy-ion potentials

    Sierk, A.J.

    1977-01-01

    The use of a modified-surface-energy approach for the calculation of heavy-ion interaction potentials is discussed. It is not possible to simultaneously fit elastic scattering, ion interaction barriers, and fission barriers with the same set of constants in this model. Possible explanations of this deficiency are discussed

  5. Heavy Ion Fusion Accelerator Research (HIFAR)

    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

  6. 238U subthreshold neutron induced fission cross section

    Difilippo, F.C.; Perez, R.B.; De Saussure, G.; Olsen, D.K.; Ingle, R.W.

    1976-01-01

    High resolution measurements of the 238 U neutron induced fission cross section are reported for neutron energies between 600 eV and 2 MeV. The average subthreshold fission cross section between 10 and 100 keV was found to be 44 +- 6 μb

  7. Mass distributions in nucleon-induced fission at intermediate energies

    Duijvestijn, M C; Hambsch, F J

    2001-01-01

    Temperature-dependent fission barriers and fission-fragment mass distributions are calculated in the framework of the multimodal random neck-rupture model (MM-RNRM). It is shown how the distinction between the different fission modes disappears at higher excitation energies, due to the melting of shell effects. The fission-fragment mass yield calculations are coupled to the nuclear reaction code ALICE-91, which takes into account the competition between the other reaction channels and fission. With the combination of the temperature-dependent MM-RNRM and ALICE-91 nucleon-induced fission is investigated at energies between 10 and 200 MeV for nuclei varying from Au to Am. (72 refs).

  8. Sterile mutant of Verbena hybrida induced by heavy ion beam irradiation and wild species V. peruviana exhibit self-incompatible phenotype

    Saito, H; Hayashi, Y; Abe, T [RIKEN, Wako (Japan); Kanaya, T; Suzuki, K [Suntory Flowers Ltd., Higashiomi (Japan)

    2005-07-01

    Full text: Garden verbenas (Verbena hybrida) belonging to the Verbenaceae family are originated from interspecific hybridization among several species, many cultivars frequently produce seeds. Recently, a sterile mutant has been isolated in the verbena cultivar 'Coral Pink' of Temari series (Suntory Flowers Ltd., Tokyo, Japan) by mutation induction using heavy-ion beams at RIKEN Accelarator Research Facility (RARF, Saitama, Japan). We investigated pollen and ovule fertility assessed by acetocarmin staining, seed-set following controlled-pollination tests and behavior of pollen tubes in pistils with the sterile mutant of 'Coral Pink' (SC) and its original fertile one (FC). As the results, although SC has functional male and female gametes, few self-pollinated flowers carry out seed-set, leading to sterile phenotype. Additionally, the sterile mechanism of SC was compared with the wild species V. peruviana (VP) which is one of origin of Temari series and exhibits sterility. Interestingly, similar phenotype was observed in PV. We further investigated, therefore, whether there are differences on self-incompatible reaction between SC and VP. (author)

  9. Sterile mutant of Verbena hybrida induced by heavy ion beam irradiation and wild species V. peruviana exhibit self-incompatible phenotype

    Saito, H.; Hayashi, Y.; Abe, T.; Kanaya, T.; Suzuki, K.

    2005-01-01

    Full text: Garden verbenas (Verbena hybrida) belonging to the Verbenaceae family are originated from interspecific hybridization among several species, many cultivars frequently produce seeds. Recently, a sterile mutant has been isolated in the verbena cultivar 'Coral Pink' of Temari series (Suntory Flowers Ltd., Tokyo, Japan) by mutation induction using heavy-ion beams at RIKEN Accelarator Research Facility (RARF, Saitama, Japan). We investigated pollen and ovule fertility assessed by acetocarmin staining, seed-set following controlled-pollination tests and behavior of pollen tubes in pistils with the sterile mutant of 'Coral Pink' (SC) and its original fertile one (FC). As the results, although SC has functional male and female gametes, few self-pollinated flowers carry out seed-set, leading to sterile phenotype. Additionally, the sterile mechanism of SC was compared with the wild species V. peruviana (VP) which is one of origin of Temari series and exhibits sterility. Interestingly, similar phenotype was observed in PV. We further investigated, therefore, whether there are differences on self-incompatible reaction between SC and VP. (author)

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

    2014-04-04

    Apr 4, 2014 ... Heavy-ion induced reactions; complete and incomplete fusion; ... CF reaction the projectile completely fuses with the target nucleus and the highly excited .... input parameters have been used as default except the charge and ...

  11. Heavy ion facility for radiation therapy

    Leemann, C.; Alonso, J.; Clark, D.; Grunder, H.; Hoyer, E.; Lou, K.; Staples, J.; Voelker, F.

    1977-03-01

    The accelerator requirements of particle radiation therapy are reviewed and a preliminary design of a heavy ion synchrotron for hospital installation is presented. Beam delivery systems and multi-treatment room arrangements are outlined

  12. Heavy-ion mammography and breast cancer

    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

  13. Historical aspects of heavy ion radiotherapy

    Raju, M.R.

    1995-01-01

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

  14. Lawrence Livermore Laboratory heavy ion fusion program

    Bangerter, R.O.; Lee, E.P.; Monsler, M.J.; Yu, S.S.

    1978-01-01

    Target design at LLL for heavy ion fusion power production is discussed, including target development and beam-target interaction. The energy conversion chamber design, which utilizes a liquid lithium blanket, is described. Ion beam transport theory is discussed

  15. Scattering and transfer reactions with heavy ions

    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

  16. Proceedings of the heavy ion fusion workshop

    Arnold, R C [ed.

    1978-01-01

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

  17. Elastic and inelastic heavy ion scattering

    Toepffer, C.; University of the Witwatersrand, Johannesburg; Richter, A.

    1977-02-01

    In the field of elastic and inelastic heavy ion scattering, the following issues are dealt with: semiclassical descriptive approximations, optical potentials, barriers, critical radii and angular momenta, excitation functions and the application to superheavy ions and high energies. (WL) [de

  18. Heavy-Ion Fusion Accelerator Research, 1991

    1992-03-01

    This report discusses the following topics: research with multiple- beam experiment MBE-4; induction linac systems experiments; and long- range research and development of heavy-ion fusion accelerators

  19. Radiobiological comparison of pions and heavy ions

    Raju, M.R.

    1981-01-01

    The physical and radiobiological differences between some aspects of pions and heavy ions are discussed, followed by a discussion of acute and late effects of high LET radiations compared to low LET radiations

  20. Working group report: Heavy ion physics

    The 8th workshop on high energy physics phenomenology (WHEPP-8) was ... by two plenary talks on experimental overview of heavy ion collisions and ... charge. At low temperature and density the quarks and gluons are confined within.

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

    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...

  2. Heavy-ion-linac post-accelerators

    Bollinger, L.M.

    1979-01-01

    The main features of the tandem-linac system for heavy-ion acceleration are reviewed and illustrated in terms of the technology and performance of the superconducting heavy-ion energy booster at Argonne. This technology is compared briefly with the corresponding technologies of the superconducting linac at Stony Brook and the room-temperature linac at Heidelberg. The performance possibilities for the near-term future are illustrated in terms of the proposed extension of the Argonne booster to form ATLAS

  3. Heavy ion collisions with the ATLAS detector

    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.)

  4. Jets in relativistic heavy ion collisions

    Wang, Xin-Nian; Gyulassy, M.

    1990-09-01

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

  5. Heavy ion drivers for inertial confinement fusion

    Keefe, D.

    1983-01-01

    The advantages of heavy ion beams as a way of delivering the needed energy and power to an inertial fusion target are surveyed. The existing broad technology base of particle accelerators provides an important foundation for designing, costing, and evaluating proposed systems. The sequence of steps needed for the verification of the heavy ion approach is described; recent research results are even more encouraging than had been assumed hitherto

  6. Heavy ion drivers for inertial confinement fusion

    Keefe, D.

    1983-12-01

    The advantages of heavy ion beams as a way of delivering the needed energy and power to an inertial fusion target are surveyed. The existing broad technology base of particle accelerators provides an important foundation for designing, costing, and evaluating proposed systems. The sequence of steps needed for the verification of the heavy ion approach is described; recent research results are even more encouraging than had been assumed hitherto

  7. Validating PHITS for heavy ion fragmentation reactions

    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)

  8. From heavy ions to exotic atoms

    Indelicato, Paul; Trassinelli, Martino

    2005-01-01

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

  9. Giant resonances in heavy-ion reactions

    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

  10. Beam dynamics in heavy ion induction LINACS

    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

  11. Localization effects in heavy ion collisions

    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

  12. Now day methods for heavy ion monitoring

    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

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

    Betak, E

    2015-01-01

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

  14. Influence of the nuclear autocorrelation function on the positron production in heavy-ion collisions

    Tomoda, T.; Weidenmueller, H.A.

    1983-01-01

    The influence of a nuclear reaction on atomic positron production in heavy-ion collisions is investigated. Using statistical concepts, we describe the nuclear S matrix for a heavy-ion induced reaction as a statistically fluctuating function of energy. The positron production rate is then dependent on the autocorrelation function of this S matrix, and on the ratio of the ''direct'' versus the ''fluctuating'' part of the nuclear cross section. Numerical calculations show that in this way, current experimental results on positron production in heavy-ion collisions can be reproduced in a semiquantitative fashion

  15. Applications of heavy ion microprobe for single event effects analysis

    Reed, Robert A.; Vizkelethy, Gyorgy; Pellish, Jonathan A.; Sierawski, Brian; Warren, Kevin M.; Porter, Mark; Wilkinson, Jeff; Marshall, Paul W.; Niu, Guofu; Cressler, John D.; Schrimpf, Ronald D.; Tipton, Alan; Weller, Robert A.

    2007-01-01

    The motion of ionizing-radiation-induced rogue charge carriers in a semiconductor can create unwanted voltage and current conditions within a microelectronic circuit. If sufficient unwanted charge or current occurs on a sensitive node, a variety of single event effects (SEEs) can occur with consequences ranging from trivial to catastrophic. This paper describes the application of heavy ion microprobes to assist with calibration and validation of SEE modeling approaches

  16. SOFIA: An innovative setup to measure complete isotopic yield of fission fragments

    Pellereau E.

    2013-12-01

    Full Text Available We performed an experiment dedicated to the accurate isotopic yield measurement of fission fragments over the whole range. SOFIA exploits the inverse kinematics technique: using heavy ion beams at relativistic energies, fission is induced by Coulomb excitation in a high-Z target. The fragments are emitted forward and both of them are identified in charge and mass. The setup will be presented, as well as preliminary spectra.

  17. Folding two dimensional crystals by swift heavy ion irradiation

    Ochedowski, Oliver; Bukowska, Hanna [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany); Freire Soler, Victor M. [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany); Departament de Fisica Aplicada i Optica, Universitat de Barcelona, E08028 Barcelona (Spain); Brökers, Lara [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany); Ban-d' Etat, Brigitte; Lebius, Henning [CIMAP (CEA-CNRS-ENSICAEN-UCBN), 14070 Caen Cedex 5 (France); Schleberger, Marika, E-mail: marika.schleberger@uni-due.de [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany)

    2014-12-01

    Ion irradiation of graphene, the showcase model of two dimensional crystals, has been successfully applied to induce various modifications in the graphene crystal. One of these modifications is the formation of origami like foldings in graphene which are created by swift heavy ion irradiation under glancing incidence angle. These foldings can be applied to locally alter the physical properties of graphene like mechanical strength or chemical reactivity. In this work we show that the formation of foldings in two dimensional crystals is not restricted to graphene but can be applied for other materials like MoS{sub 2} and hexagonal BN as well. Further we show that chemical vapour deposited graphene forms foldings after swift heavy ion irradiation while chemical vapour deposited MoS{sub 2} does not.

  18. Folding two dimensional crystals by swift heavy ion irradiation

    Ochedowski, Oliver; Bukowska, Hanna; Freire Soler, Victor M.; Brökers, Lara; Ban-d'Etat, Brigitte; Lebius, Henning; Schleberger, Marika

    2014-01-01

    Ion irradiation of graphene, the showcase model of two dimensional crystals, has been successfully applied to induce various modifications in the graphene crystal. One of these modifications is the formation of origami like foldings in graphene which are created by swift heavy ion irradiation under glancing incidence angle. These foldings can be applied to locally alter the physical properties of graphene like mechanical strength or chemical reactivity. In this work we show that the formation of foldings in two dimensional crystals is not restricted to graphene but can be applied for other materials like MoS 2 and hexagonal BN as well. Further we show that chemical vapour deposited graphene forms foldings after swift heavy ion irradiation while chemical vapour deposited MoS 2 does not

  19. Electron-positron pair creation in heavy ion collisions

    Kienle, P.

    1987-08-01

    We review here the status of experiments to study the electron positron pair creation in heavy ion atom collisions at bombarding energies close to the Coulomb barrier. The disentanglement and characterisation of various sources of positrons observed in such collisions are described with a focus on the monoenergetic electron positron pairs observed. They seem to originate from the two-body decay of a family of neutral particles with masses of about 3 m e and life times in the range of 6x10 -14 s -10 s, produced by high Coulomb fields. First attempts were made to create these particles by resonant Bhabha scattering. First we present some experimental methods for high efficiency positron spectroscopy in heavy ion collisions. Then we describe the discovery of positron creation induced by strong time changing Coulomb fields. (orig./HSI)

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

    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.

  1. Fusion-fission dynamics

    Blocki, J.; Planeta, R.; Brzychczyk, J.; Grotowski, K.

    1991-04-01

    Classical dynamical calculations of the heavy ion induced fission process for the reactions 40 Ar+ 141 Pr, 20 Ne+ 165 Ho and 12 C+ 175 Lu leading to the iridium like nucleus have been performed. As a result prescission lifetimes were obtained and compared with the experimental values. The agreement between the calculated and experimental lifetimes indicates that the one-body dissipation picture is much more relevant in describing the fusion-fission dynamics than the two-body one. Somewhat bigger calculated times than the experimental ones in case of the C+Lu reaction at 16 MeV/nucleon may be a signal on the energy range applicability of the one-body dissipation model. (author)

  2. Combination of chemotherapy and heavy-ion particle therapy for gastrointestinal cancer

    Yamada, Shigeru; Kitabayashi, Hiroyuki; Furusawa, Yoshiya; Ando, Koichi

    2005-01-01

    The purpose of this study is to investigate the combination of chemotherapy and heavy-ion particle therapy for pancreas and esophageal cancer. We measured surviving fractions in four culture pancreas and esophageal cancer cells. The cell killing of heavy-ion irradiation is more effective compared to that of X ray irradiation. Gemcitabine induced radiosensitization for pancreas cancer cells and also taxotel for esophageal cancer. (author)

  3. Nuclear research with heavy ions

    Kaplan, M.

    1992-08-01

    This report discusses the following topics; studies of light-charged-particle emission from fission and er reactions in the system 344-MeV 28 Si+ 121 Sb → 149 Tb; the role of reversed kinematics and double kinematic solutions in nuclear reactions studies; improvements in interactive data analysis and graphical representations; studies of the reaction 856-MeV 98 Mo + 51 V→ 149 Tb(E*=224-MeV): emission of intermediate-mass fragments; particle-particle correlations in compound nucleus reactions: preliminary consideration of lifetime estimates from small angle data; light particle emission studies using a new scintillator array; statistical evaporation calculations: developments with the computer codes LILITA-N90 and CASCADE; star collaboration studies: simulations for the conceptual design of the STAR detector system at RHIC; asymmetric fission of 149Tb* from the finite-range, rotating-liquid-drop model: mean total kinetic energies for binary fragmentation; and charged-particle evaporation from hot composite nuclei: evidence over a broad z range for distortions from cold nuclear profiles

  4. Actinide neutron-induced fission cross section measurements at LANSCE

    Tovesson, Fredrik K [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

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

    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

  6. Electromagnetic dissociation of 238U in heavy-ion collisions at 120 MeV/A

    Justice, M.L.

    1991-04-01

    This thesis describes a measurement of the heavy-ion induced electromagnetic dissociation of a 120 MeV/A 238 U beam incident on five targets: 9 Be, 27 Al, nat Cu, nat Ag, and nat U. Electromagnetic dissociation at this beam energy is essentially a two step process involving the excitation of a giant resonance followed by particle decay. At 120 MeV/A there is predicted to be a significant contribution of the giant quadrupole resonance to the EMD cross sections. The specific exit channel which was looked at was projectile fission. The two fission fragments were detected in coincidence by an array of solid-state ΔE-E detectors, allowing the changes of the fragments to be determined to within ± .5 units. The events were sorted on the basis of the sums of the fragments' charges, acceptance corrections were applied, and total cross sections for the most peripheral events were determined. Electromagnetic fission at the beam energy of this experiment always leads to a true charge sum of 92. Due to the imperfect resolution of the detectors, charge sums of 91 and 93 were included in order to account for all of the electromagnetic fission events. The experimentally observed cross sections are due to nuclear interaction processes as well as electromagnetic processes. Under the conditions of this experiment, the cross sections for the beryllium target are almost entirely due to nuclear processes. The nuclear cross sections for the other four targets were determined by extrapolation from the beryllium data using a geometrical scaling model. After subtraction of the nuclear cross sections, the resulting electromagnetic cross sections are compared to theoretical calculations based on the equivalent photon approximation. Systematic uncertainties are discussed and suggestions for improving the experiment are given

  7. Hot nuclei production and deexcitation in heavy ions induced reactions on medium mass targets in the 10-84 MeV/nucleon energy domain

    Lleres, A.

    1988-01-01

    Velocity, angular distributions and total cross sections for heavy residues produced in the reactions 12 C, 14 N, 20 Ne, 40 Ar + 124 Sn have been measured in the 10-84 MeV/nucleon incident energy range using catchers technique in association with off-line gamma-activity spectroscopy. The observed reaction products are interpreted as evaporation residues from equilibrated systems formed by complete or incomplete fusion of the projectile and target nuclei. From the velocities and residual masses measured at forward angles, the linear momentum transfers and excitation energies associated with the intermediate systems are estimated using simple fusion-evaporation models and are next compared to the predictions of the preequilibrium and Fermi jets models. Energy, angular, charge and charge correlation distributions for intermediate mass fragments emitted in the reaction 32 S + nat Ag at 30 MeV/nucleon were also measured using gaseous and silicon detectors. The energy and angular distributions indicate that both equilibrated and non-equilibrated emitting sources are present. The equilibrium emission is attributed to the deexcitation of systems produced by incomplete fusion of the projectile and target nuclei. The charge correlation distributions are consistent with an asymmetric fission decay process. The linear momentum transfer and excitation energy associated with the equilibrated source are estimated using a simple fusion-fission model [fr

  8. Study on broad beam heavy ion CT

    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)

  9. Heavy ion induction linacs for fusion

    Bangerter, R.O.; Ho, D.D.M.

    1991-01-01

    In 1976 Denis Keefe proposed the heavy ion induction linac as a driver for inertial confinement fusion (ICF) power plants. Subsequent research has established that heavy ion fusion (HIF) is potentially an attractive energy source and has identified the issues that must be resolved to make HIF a reality. The principal accelerator issues are achieving adequately low transverse and longitudinal emittance and acceptable cost. Results from the single and multiple beam experiments at LBL on transverse emittance are encouraging. A predicted high current longitudinal instability that can affect longitudinal emittance is currently being studied. This paper presents an overview of economics and ICF target requirements and their relationship to accelerator design. It also presents a summary of the status of heavy ion induction linac research. It concludes with a discussion of research plans, including plans for the proposed Induction Linac Systems Experiments (ILSE)

  10. Synchrotrons for heavy ions: Bevalac experience

    Grunder, H.A.; Gough, R.A.; Alonso, J.R.

    1980-10-01

    The Bevalac should be viewed not as a model of accelerator hardware - a modern heavy ion complex will look quite different, but as a model for an operating versatile multifaceted, multiuser heavy ion facility. Of value to the planning of a new accelerator such as MARIA is the knowledge of operating modes peculiar to heavy ions and specific hardware requirements to carry out its mission with the mandated flexibility and reliability. This paper starts with a discussion of parameters and machine characteristics most suitable for medical and nuclear science applications. It then covers experience in interleaving these two research programs, and finally, concentrates on accelerator configuratin questions; injectors, repetition rate, vacuum systems and cost criteria which will be relevant to the design of MARIA

  11. Cyclotron method for heavy ion acceleration

    Gikal, B.N.; Gul'bekyan, G.G.; Kutner, V.B.; Oganesyan, R.Ts.

    1984-01-01

    Studies on heavy ion beams in a wide range of masses (up to uranium) and energies disclose essential potential opportunities for solution of both fundamental scientific and significant economical problems. A cyclotron method for heavy ion acceleration is considered. Development of low and medium energy heavy ion accelerators is revealed. The design of a complex comprising two isochronous cyclotrons which is planned to be constrdcted 1n the JINR is described. The cyclotron complex includes the U-400 and the U-400 M cyclotrons and it is intended for acceleration of both 35-20 MeV/nucleon superheavy ions such as Xe-U and 120 MeV/nucleon light ions. Certain systems of the accelerators are described. Prospects of the U-400 and the U-400 M development are displayed

  12. The Growth of Sea cucumber Stichopus herrmanni After Transverse Induced Fission in Two and Three Fission Plane

    Retno Hartati

    2016-06-01

    Full Text Available Transverse induced fission proven could be done in Teripang Tril, Stichopus herrmanni. This present works aimed to analyze wound recovery, regeneration period and growth of Teripang Trill  after asexual reproduction by fission using two and three fission plane. Observations were made every day until the sea cucumber body separated into two or more (depending on treatment and reared for 16 weeks.  The results showed that there are differences in wound recovery, regeneration period and growth of S. herrmanni depend on their different fission plane. The wound recovery and regeneration period (days of anterior, middle and posterior individu S. herrmanni resulted from two and three fission plane were varied but the two fission plane the anterior individu recover for longer period than posterior part and  the wound recover process in both end for thee fission plane was same. Average growth of anterior and posterior fragment were longer for two fission plane than three fission plane.  The middle fragment (M1 and M2 both fission plane was able to grow but very low.  It showed that three fission plane gave very slow growth in every fragment of the body. Keywords: growth, post-fission, fission plane, Stichopus herrmanni

  13. Hard photons a probe of the heavy ion collision dynamics

    Schutz, Y.

    1994-01-01

    Heavy-ion collisions have proven to be a unique tool to study the nucleus in extreme states, with values of energy, spin and isospin far away from those encountered in the nucleus in its ground state. Heavy-ion collisions provide also the only mean to form and study in the laboratory nuclear matter under conditions of density and temperature which could otherwise only be found in stellar objects like neutron stars and super-novae. the goal of such studies is to establish the equation of state of nuclear matter and the method consist in searching the collective behaviour in which heavy-ion collisions differ from a superposition of many nucleon-nucleon collisions. Among the various probes of collective effects, like flow, multifragmentation, or subthreshold particles, we have selected hard photons because they provide, together with dileptons, the only unperturbed probe of a phase of the collision well localized in space and time. The origin of hard photons, defined as the photons building up the spectrum beyond the energy of the giant dipole resonance (E γ > 30∼MeV), is attributed predominantly to the bremsstrahlung radiation emitted incoherently in individual neutron-proton collisions. Their energy reflects the combination of the beam momentum and the momenta induced by the Fermi motion of the nucleons within the collision zone. Therefore, at intermediate energies, hard photons probe the dynamical phase space distribution of participant nucleons and they convey information on the densities reached in heavy-ion collisions, the size and life time of the dense photon source and the compressibility of nuclear matter. The techniques we have developed include intensity interferometry and exclusive measurements scanning with high resolution the whole range of impact parameters. The interpretation of our data is guided by dynamical phase space calculations of the BUU type

  14. Nuclear fission: a review of experimental advances and phenomenology

    Andreyev, A. N.; Nishio, K.; Schmidt, K.-H.

    2018-01-01

    In the last two decades, through technological, experimental and theoretical advances, the situation in experimental fission studies has changed dramatically. With the use of advanced production and detection techniques both much more detailed and precise information can now be obtained for the traditional regions of fission research and, crucially, new regions of nuclei have become routinely accessible for fission studies. This work first of all reviews the recent developments in experimental fission techniques, in particular the resurgence of transfer-induced fission reactions with light and heavy ions, the emerging use of inverse-kinematic approaches, both at Coulomb and relativistic energies, and of fission studies with radioactive beams. The emphasis on the fission-fragment mass and charge distributions will be made in this work, though some of the other fission observables, such as prompt neutron and γ-ray emission will also be reviewed. A particular attention will be given to the low-energy fission in the so far scarcely explored nuclei in the very neutron-deficient lead region. They recently became the focus for several complementary experimental studies, such as β-delayed fission with radioactive beams at ISOLDE(CERN), Coulex-induced fission of relativistic secondary beams at FRS(GSI), and several prompt fusion–fission studies. The synergy of these approaches allows a unique insight in the new region of asymmetric fission around {\\hspace{0pt}}180 Hg, recently discovered at ISOLDE. Recent extensive theoretical efforts in this region will also be outlined. The unprecedented high-quality data for fission fragments, completely identified in Z and A, by means of reactions in inverse kinematics at FRS(GSI) and VAMOS(GANIL) will be also reviewed. These experiments explored an extended range of mercury-to-californium elements, spanning from the neutron-deficient to neutron-rich nuclides, and covering both asymmetric, symmetric and transitional fission regions

  15. Heavy-ion interactions of deformed nuclei. Progress report and final report, January 1, 1985-December 31, 1985

    Oberacker, V.E.

    1985-09-01

    This Progress Report describes the main topics that were investigated during the reporting period: (1) a new microscopic approach (many-body theory with two-center shell model basis) to the calculation of heavy-ion interaction potentials, primarily for heavy systems; (2) dynamic alignment of deformed nuclei during heavy-ion collisions; (3) the role of shell effects, static deformation and dynamic alignment in heavy-ion fusion reactions; (4) giant nuclear quasimolecules and the positron problem. The proposed research has direct relevance to experimental programs supported by DOE, e.g. the Holifield Heavy-Ion Research Facility (HHIRF) at Oak Ridge, the ATLAS accelerator at Argonne National Laboratory, the Double MP Tandem at Brookhaven and some of the smaller University-based accelerators. A discussion of a review article on Coulomb fission is presented. 36 refs., 7 figs

  16. Induction linacs for heavy ion fusion

    Keefe, D.

    1986-11-01

    Experimental progress to date has strengthened our belief in the soundness and attractiveness of the heavy ion method for fusion. What surprises that have shown up in the laboratory (e.g., in SBTE) have all been of the pleasant kind so far. The systems assessment has supported the view that the heavy ion approach can lead to economically attractive electric power and that a wide variety of options exists in all parameters. The systems work has also been of great help in pointing the way for the research and development activities

  17. Penetration of relativistic heavy ions through matter

    Scheidenberger, C.; Geissel, H.

    1997-07-01

    New heavy-ion accelerators covering the relativistic and ultra-relativistic energy regime allow to study atomic collisions with bare and few-electron projectiles. High-resolution magnetic spectrometers are used for precise stopping-power and energy-loss straggling measurements. Refined theories beyond the Born approximation have been developed and are confirmed by experiments. This paper summarizes the large progress in the understanding of relativistic heavy-ion penetration through matter, which has been achieved in the last few years. (orig.)

  18. Next generation of relativistic heavy ion accelerators

    Grunder, H.; Leemann, C.; Selph, F.

    1978-06-01

    Results are presented of exploratory and preliminary studies of a next generation of heavy ion accelerators. The conclusion is reached that useful luminosities are feasible in a colliding beam facility for relativistic heavy ions. Such an accelerator complex may be laid out in such a way as to provide extractebeams for fixed target operation, therefore allowing experimentation in an energy region overlapping with that presently available. These dual goals seem achievable without undue complications, or penalties with respect to cost and/or performance

  19. Improvement of herbage by heavy ion beams

    Xie Hongmei; Hao Jifang; Wei Zengquan; Xie Zhongkui; Li Fengqin; Wang Yajun

    2004-01-01

    Herbage seeds of legume and grass were irradiated in penetration by 80 MeV/u 20 Ne 10+ ions. The results of field tests and observations of the root-tip cells showed that growth of the seedling was obviously weakened with increasing doses. Frequencies of chromosomal aberration and micronucleus increased significantly with increasing doses. According to the field growth tests, radiation sensitivity of grass herbage to the heavy ion beams was much higher than leguminous herbage, and suitable dose of the heavy ion irradiation for the grass and leguminous herbage is 20-30 Gy and 150 Gy, respectively

  20. Heavy ion and hadron reactions in emulsion

    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)

  1. Review of BNL heavy ion physics

    Miake, Yasuo.

    1990-01-01

    With an intent to search for a new state of matter, a relativistic heavy ion program was started in 1986 at BNL. Several interesting features have been reported from BNL-AGS heavy ion experiments, among which are: the enhanced K + /π + ratio and the larger left-angle m t right-angle for K + and proton. Comparisons between ∼pp, pA and SiA collisions are discussed for m t and dn/dy distributions. 33 refs., 9 figs., 1 tab

  2. Bremsstrahlung from relativistic heavy ions in matter

    Sørensen, Allan Hvidkjær

    2010-01-01

    The emission of electromagnetic radiation by relativistic bare heavy ions penetrating ordinary matter is investigated. Our main aim is to determine the bremsstrahlung which we define as the radiation emitted when the projectile does not break up. It pertains to collisions without nuclear contact....... As a result of its relative softness, bremsstrahlung never dominates the energy-loss process for heavy ions. As to the emission of electromagnetic radiation in collisions with nuclear break-up, it appears modest when pertaining to incoherent action of the projectile nucleons in noncontact collisions...

  3. Hadron chemistry in heavy ion collisions

    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.)

  4. Jets in heavy ion collisions with CMS

    Salur, Sevil

    2016-01-01

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

  5. Heavy ion medical accelerator in chiba

    Hirao, Y.; Ogawa, H.; Yamada, S.

    1992-12-01

    The HIMAC (Heavy Ion Medical Accelerator in Chiba) construction project has been promoted by NIRS (National Institute of Radiological Sciences) as one of the projects of 'Comprehensive 10 year Strategy for Cancer Control' HIMAC is the first heavy-ion accelerator dedicated to medicine in the world, and its design parameters are based on the radiological requirements. It consists of two types of ion sources, an RFQ and an Alvarez linacs, dual synchrotron rings, high energy beam transport lines, and irradiation facilities for treatment and experiments. This report mainly describes the outline of the structure and performance of each HIMAC subsystem. (J.P.N.)

  6. Energy straggling of heavy ions in solids

    Cowern, N.E.B.

    1979-08-01

    The energy-loss straggling of heavy ions has been studied, principally in the Born Approximation region v > zv 0 . Measurements were made with 5.486 MeV α particles, 5 - 48 MeV 16 0 ions, and 3 - 36 MeV 12 C ions, incident on thin uniform Al foils. The thickness uniformity of the foils was studied with a proton microbeam and a surface profiler, and their homogeneity, purity and isotropy were investigated by electron microscope, proton backscattering, and X-ray diffraction studies. Using the Bethe theory of energy loss the charge-exchange model of energy straggling for heavy ions is confirmed. (author)

  7. Heavy-ion driver design and scaling

    Bieri, R.; Monsler, M.; Meier, W.; Stewart, L.

    1992-01-01

    Parametric models for scaling heavy-ion driver designs are described. Scaling of target performance and driver cost is done for driver parameters including driver energy, number of beams, type of superconductor used in focusing magnets, maximum magnetic field allowed at the superconducting windings, linear quadrupole array packing fraction mass, and ion charge state. The cumulative accelerator voltage and beam currents are determined from the Maschke limits on beam current for each choice of driver energy and post-acceleration pulse duration. The heavy-ion driver is optimized over the large available driver parameter space. Parametric studies and the choice of a base driver model are described in a companion paper

  8. Development of heavy ion linear accelerators

    Bomko, V.A.; Khizhnyak, N.A.

    1981-01-01

    A review of the known heavy ion accelerators is given. It is stated that cyclic and linear accelerators are the most perspective ones in the energy range up to 10 MeV/nucleon according to universality in respect with the possibility of ion acceleration of the wide mass range. However, according to the accelerated beam intensity of the heavier ions the linear accelerators have considerable advantages over any other types of accelerators. The review of the known heavy ion linac structures permits to make the conclusion that a new modification of an accelerating structure of opposite pins excited on a H-wave is the most perspective one [ru

  9. New developments in heavy ion fusion

    Herrmannsfeldt, W.B.

    1984-01-01

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

  10. Fusion--fission hybrid concepts for laser-induced fusion

    Maniscalco, J.

    1976-01-01

    Fusion-fission hybrid concepts are viewed as subcritical fission reactors driven and controlled by high-energy neutrons from a laser-induced fusion reactor. Blanket designs encompassing a substantial portion of the spectrum of different fission reactor technologies are analyzed and compared by calculating their fissile-breeding and fusion-energy-multiplying characteristics. With a large number of different fission technologies to choose from, it is essential to identify more promising hybrid concepts that can then be subjected to in-depth studies that treat the engineering safety, and economic requirements as well as the neutronic aspects. In the course of neutronically analyzing and comparing several fission blanket concepts, this work has demonstrated that fusion-fission hybrids can be designed to meet a broad spectrum of fissile-breeding and fusion-energy-multiplying requirements. The neutronic results should prove to be extremely useful in formulating the technical scope of future studies concerned with evaluating the technical and economic feasibility of hybrid concepts for laser-induced fusion

  11. Fission induced swelling of U–Mo/Al dispersion fuel

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Jeong, G.Y. [Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Uljoo-gun, Ulsan 689-798 (Korea, Republic of); Park, J.M. [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Robinson, A.B. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2015-10-15

    Fission-induced swelling of U–Mo/Al dispersion fuel meat was measured using microscopy images obtained from post-irradiation examination. The data of reduced-size plate-type test samples and rod-type test samples were employed for this work. A model to predict the meat swelling of U–Mo/Al dispersion fuel was developed. This model is composed of several submodels including a model for interaction layer (IL) growth between U–Mo and Al matrix, a model for IL thickness to IL volume conversion, a correlation for the fission-induced swelling of U–Mo alloy particles, a correlation for the fission-induced swelling of IL, and models of U–Mo and Al consumption by IL growth. The model was validated using full-size plate data that were not included in the model development.

  12. Radial and tangential friction in heavy ion strongly damped collisions

    Jain, A.K.; Sarma, N.

    1979-01-01

    Deeply inelastic heavy ion collisions have been successfully described in terms of a nucleon exchange mechanism between two nucleon clouds. This model has also predicted the large angular momentum that is induced in the colliding nuclei. However computations were simplified in the earlier work by assuming that the friction was perturbation on the elastic scattering trajectory. Results of a more rigorous calculation are reported and the effect of modification of the trajectory on the energy transfer, the angular momentum induced and on the ratio of the radial to the tangential friction coefficients is reported. (auth.)

  13. rf linac approach to heavy ion fusion

    Swenson, D.A.

    1979-01-01

    The necessary properties of funneling particle beams from multiple accelerators into combined beams having higher current are outlined, and methods are proposed which maximize the efficiency of this process. A heavy ion fusion driver system example is presented which shows the large advantages in system efficiency to be gained by proper funneling

  14. Review of heavy ion reaction mechanisms

    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

  15. New generation of heavy ion facilities

    Ball, J.B.

    1977-01-01

    A report is given on the status of major heavy ion accelerator projects that are funded and under construction and a few still in the proposal state. New facilities that are expected to become operational between now and the mid-1980's are reviewed. The major directions being pursued by this next generation of machines and new features being introduced are discussed

  16. Prospects for Heavy Ion Physics with LHCb

    Manca, Giulia

    2016-12-15

    We will discuss the potential of the LHCb experiment in the field of Heavy Ion physics. We will analyse three different scenarios which can be explored by the experiment, namely collisions of protons with lead, lead with lead and proton or lead beams with a gas injected in the interaction region. We will also show results in some of these configurations.

  17. Detectors for relativistic heavy-ion experiments

    Braun-Munzinger, P.; Cleland, W.; Young, G.R.

    1989-04-01

    We present in some detail an overview of the detectors currently used in relativistic heavy-ion research at the BNL AGS and the CERN SPS. Following that, a detailed list of RandD projects is given, including specific areas of work which need to be addressed in preparation for further experiments at the AGS and SPS for the upcoming experiments at RHIC

  18. Physics with heavy ions at LHC

    Safarik, K.

    2004-01-01

    We discuss the motivation to study heavy ion collisions at LHC, and the experimental conditions under which detectors will have to operate. A short description of the detectors under construction is given. Physics performance is illustrated in two examples, which will become accessible at LHC energies, jet quenching and heavy-flavor production. (author)

  19. Heavy ion measurements at ATLAS and CMS

    Chapon, Emilien

    2018-01-01

    We present an overview of recent results from the ATLAS and CMS collaborations on heavy ion physics. Using data from proton-proton, proton-lead and lead-lead collisions at the LHC, these results help to shed light on the properties of nuclear matter.

  20. Jet Tomography in Heavy Ion Collisions

    Wiedemann, Urs Achim

    2003-01-01

    We review recent calculations of the probability that a hard parton radiates an additional energy fraction due to scattering in spatially extended matter, and we discuss their application to the suppression of leading hadron spectra in heavy ion collisions at collider energies.

  1. Recirculating induction accelerators for heavy ion fusion

    Barnard, J.J.; Deadrick, F.; Bangerter, R.O.

    1993-01-01

    We have recently completed a two-year study of recirculating induction heavy-ion accelerators (recirculators) as low-cost drivers for inertial-fusion-energy power plants. We present here a summary of that study and other recent work on recirculators

  2. Accelerator development for heavy ion fusion

    Talbert, W.L. Jr.; Sawyer, G.A.

    1980-01-01

    Accelerator technology development is presented for heavy ion drivers used in inertial confinement fusion. The program includes construction of low-velocity ''test bed'' accelerator facilities, development of analytical and experimental techniques to characterize ion beam behavior, and the study of ion beam energy deposition

  3. HIGH DENSITY QCD WITH HEAVY-IONS

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

  4. Heavy ion elastic scattering of code : OPTHI

    Ismail, M.; Divatia, A.S.

    1982-01-01

    A computer code, OPTHI has been designed to calculate nuclear optical model elastic cross sections for the scattering of heavy ions. The program has been designed to be utilitarian rather than capable of giving an exact description of elastic scattering. Input format is described and the program listing is given. (M.G.B.)

  5. RELATIVISTIC HEAVY ION PHYSICS: A THEORETICAL OVERVIEW.

    KHARZEEV,D.

    2004-03-28

    This is a mini-review of recent theoretical work in the field of relativistic heavy ion physics. The following topics are discussed initial conditions and the Color Glass Condensate; approach to thermalization and the hydrodynamic evolution; hard probes and the properties of the Quark-Gluon Plasma. Some of the unsolved problems and potentially promising directions for future research are listed as well.

  6. Heavy-ion fusion accelerator research, 1989

    1990-06-01

    This report discusses the following topics on heavy-ion fusion accelerator research: MBE-4: the induction-linac approach; transverse beam dynamics and current amplification; scaling up the results; through ILSE to a driver; ion-source and injector development; and accelerator component research and development

  7. Beginnings and advances in heavy ion research

    Brix, P.

    1979-01-01

    The very important field of heavy ion research is briefly reviewed from the beginnings up to the present time. The article was intended to be a scientific lecture for the general public read on the occasion of the 70th birthday of Prof. Schmelzer. (KBE)

  8. The technology of heavy-ion fusion

    Lawson, J.D.

    1980-09-01

    The concept of inertial confinement fusion using heavy ion beams as a driver is surveyed, with reference to parameters which might ultimately be suitable for a commercial power station. Particular attention is drawn to the parameters associated with the final focusing of the beam on the target. (author)

  9. Experiments on very high energy heavy ions

    Willis, W.J.

    1981-01-01

    In this paper I describe experimental techniques which could be used to investigate central collision of very high energy heavy ions. For my purposes, the energy range is defined by the number of pions produced, Nsub(π) >> 100, and consequently Nsub(π) >> Nsub(nucleon). In this regime we may expect that new phenomena will appear. (orig.)

  10. Summary of the Relativistic Heavy Ion Sessions

    Harris, J.W.

    1988-07-01

    This paper briefly discusses the topics covered in the relativistic heavy ion in sessions. The prime motivation for these investigations is the possibility of forming quark matter, therefore the formation of a quark-gluon plasma. Topics on suppression of J//psi/ production, th equation of state of nuclear matter, transverse energy distributions and two pion interferometry techniques are discussed. 38 refs

  11. Heavy ion fragmentation in high energy

    Nemes, M.C.

    1985-01-01

    A review is made on the theoretical aspects of heavy ion collisions at high energies. A comparison with several experimental data obtained in a large variety of experiments is present. An emphasis is given on the basis of Glauber's theory of scattering. (L.C.) [pt

  12. A heavy load for heavy ions

    2003-01-01

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

  13. Heavy ion acceleration at the AGS

    Lee, Y.Y.

    1989-01-01

    The Brookhaven AGS is alternating gradient synchrotron, 807 meters in circumference, which was originally designed for only protons. Using the 15 MV Brookhaven Tandem Van de Graaff as an injector, the AGS started to accelerate heavy ions of mass lighter than sulfur. Because of the relatively poor vacuum (∼10 -8 Torr), the AGS is not able to accelerate heavier ions which could not be fully stripped of electrons at the Tandem energy. When the AGS Booster, which is under construction, is completed the operation will be extended to all species of heavy ions including gold and uranium. Because ultra-high vacuum (∼10 -11 Torr) is planned, the Booster can accelerate partially stripped elements. The operational experience, the parameters, and scheme of heavy ion acceleration will be presented in detail from injection to extraction, as well as future injection into the new Relativistic Heavy Ion Collider (RHIC). A future plan to improve intensity of the accelerator will also be presented. 5 figs., 4 tabs

  14. Sigma meson in heavy ion collision

    Cristian, Ivan; Fuchs, Christian

    2004-01-01

    We want to present a short theoretical prediction of the behaviour of the sigma meson in heavy ion collisions. It is considered that the sigma meson is a pion-pion correlation, resulting from the decay of the N*(1440) resonance. There will be presented some QMD simulations. (authors)

  15. Heavy ion reactions at low energies

    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

  16. Review of heavy ion collider proposals

    Ruggiero, A.G.

    1985-01-01

    In this paper we review proposals for heavy-ion colliders generated during the last few years for several national laboratories. The proposals span over a large range of energy and luminosity to accommodate the experimental needs of both the nuclear and the high-energy physicists. We report also briefly efforts in the same field happening in Europe

  17. Ultrarelativistic heavy ion collisions Theoretical overview

    Blaizot, Jean-Paul

    2006-01-01

    This is a short review of some theoretical aspects of the physics of ultra-relativistic heavy ion collisions. I review the main properties of the QCD phase diagram and recent developments in the physics of high gluon densities in the hadronic wavefunctions at high energy. Then I comment salient results obtained at RHIC

  18. Study of heavy ion collisions with TAPS

    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

  19. Modifications induced by swift heavy ions in poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) and poly(ε-caprolactone) (PCL) films. Part 1. Thermal behaviour and molecular mass modifications

    Rouxhet, L.; Legras, R.

    2000-01-01

    Modifications induced by different energetic heavy ions in poly(ε-caprolactone) (PCL) and poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) have been investigated by the differential scanning calorimetry (DSC) and steric exclusion chromatography (SEC). A certain dose of damages, depending mainly on the charge and mass of the ion and on the intensity of irradiation, has to be overcome in order to detect any effect on PHB/HV. Actually, at a given intensity of irradiation, superior to 10 10 ions/cm 2 , the level of damage intensity increased with the increase in charge and mass of the ion. Moreover, according to the SEC results, there seems to be a critical mass and/or charge threshold above which the dominant type of damages changes. As a matter of fact, high-density irradiation with Ar 9+ and Kr 15+ resulted mainly in chain scission whereas cross-linking was dominant when irradiating the polymer with Xe 24+ and Pb 56+ . The irradiation of PCL in the conditions studied did not modify significantly the values of the melting point, the crystallisation temperature and the molecular masses of the system studied. The main effect of the irradiation detected by the DSC is the cross-linking of the polymer chains

  20. Heavy ion driven LMF design concept

    Lee, E.P.

    1991-08-01

    The USA Department of Energy has conducted a multi-year study of the requirements, designs and costs for a Laboratory Microfusion Facility (LMF). The primary purpose of the LMF would be testing of weapons physics and effects simulation using the output from microexplosions of inertial fusion pellets. It does not need a high repetition rate, efficient driver system as required by an electrical generating plant. However there would be so many features in common that the design, construction and operation of an LMF would considerably advance the application of inertial confinement fusion to energy production. The DOE study has concentrated particularly on the LMF driver, with design and component development undertaken at several national laboratories. Principally, these are LLNL (Solid State Laser), LANL (Gas Laser), and SNLA (Light Ions). Heavy Ions, although considered a possible LMF driver did not receive attention until the final stages of this study since its program management was through the Office of Energy Research rather than Defense Programs. During preparation of a summary report for the study it was decided that some account of heavy ions was needed for a complete survey of the driver candidates. A conceptual heavy ion LMF driver design was created for the DOE report which is titled LMC Phase II Design Concepts. The heavy ion driver did not receive the level of scrutiny of the other concepts and, unlike the others, no costs analysis by an independent contractor was performed. Since much of heavy ion driver design lore was brought together in this exercise it is worthwhile to make it available as an independent report. This is reproduced here as it appears in the DOE report