WorldWideScience

Sample records for swift ion irradiated

  1. Folding two dimensional crystals by swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Folding two dimensional crystals by swift heavy ion irradiation

    International Nuclear Information System (INIS)

    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

  3. Development of Nanoporous Polymer Membranes by Swift Heavy Ion Irradiation

    Science.gov (United States)

    Dinesh, Divya; Predeep, P.

    2011-10-01

    This study reveals the preparation of conical pores in polyethylene terephthalate (PET) by track etching. The polymer membrane is etched from one side by keeping between the clamps of conductivity cell followed by irradiation with swift heavy ion of 197Au. Electrical stopping supports chemical stopping. During etching process current is measured as a function of time till a sharp increase -breakthrough-observed. After etching membranes are thoroughly washed with stopping solution and water. Resultant films are characterized using Optical microscope and field emission scanning electron microscopy. Polymer films with uniform pores can be a cheaper templating material in the fields of photonic crystals and micro- electronics.

  4. Degradation of polyimide under irradiation with swift heavy ions

    International Nuclear Information System (INIS)

    Severin, D.; Ensinger, W.; Neumann, R.; Trautmann, C.; Walter, G.; Alig, I.; Dudkin, S.

    2005-01-01

    Stacks of polyimide foils were irradiated with different swift heavy ions (Ti, Mo, Au) of 11.1 MeV/nucleon energy and fluences between 1 x 10 10 and 2 x 10 12 ions/cm 2 . Beam-induced degradation of the imide group was analyzed by Fourier-transform infrared spectroscopy studying the absorption band at 725 cm -1 as a function of dose. In the UV-Vis spectral range, the absorption edge is shifted to larger wavelengths indicating carbonization. Such modifications are linked to the deposition of a critical dose of 2.7 MGy (Ti) and 1 MGy (Mo, Au). In addition, irradiation-induced changes of the electrical conductivity were studied by means of dielectric spectroscopy

  5. Damage induced in semiconductors by swift heavy ion irradiation

    International Nuclear Information System (INIS)

    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

  6. Structural characterization of swift heavy ion irradiated polycarbonate

    International Nuclear Information System (INIS)

    Singh, Lakhwant; Samra, Kawaljeet Singh

    2007-01-01

    Makrofol-N polycarbonate thin films were irradiated with copper (50 MeV) and nickel (86 MeV) ions. The modified films were analyzed by UV-VIS, FTIR and XRD techniques. The experimental data was used to evaluate the formation of chromophore groups (conjugated system of bonds), degradation cross-section of the special functional groups, the alkyne formation and the amorphization cross-section. The investigation of UV-VIS spectra shows that the formation of chromophore groups is reduced at larger wavelength, however its value increases with the increase of ion fluence. Degradation cross-section for the different chemical groups present in the polycarbonate chains was evaluated from the FTIR data. It was found that there was an increase of degradation cross-section of chemical groups with the increase of electronic energy loss in polycarbonate. The alkyne and alkene groups were found to be induced due to swift heavy ion irradiation in polycarbonate. The radii of the alkyne production of about 2.74 and 2.90 nm were deduced for nickel (86 MeV) and copper (50 MeV) ions respectively. XRD analysis shows the decrease of the main XRD peak intensity. Progressive amorphization process of Makrofol-N with increasing fluence was traced by XRD measurements

  7. Structural response of titanate pyrochlores to swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Shamblin, Jacob; Tracy, Cameron L.; Ewing, Rodney C.; Zhang, Fuxiang; Li, Weixing; Trautmann, Christina; Lang, Maik

    2016-01-01

    The structure, size, and morphology of ion tracks resulting from irradiation of five different pyrochlore compositions (A 2 Ti 2 O 7 , A = Yb, Er, Y, Gd, Sm) with 2.2 GeV 197 Au ions were investigated by means of synchrotron X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Radiation-induced amorphization occurred in all five materials analyzed following an exponential rate as a function of ion fluence. XRD patterns showed a general trend of increasing susceptibility of amorphization with increasing ratio of A- to B-site cation ionic radii (r A /r B ) with the exception of Y 2 Ti 2 O 7 and Sm 2 Ti 2 O 7 . This indicates that the track size does not necessarily increase with r A /r B , in contrast with results from previous swift heavy ion studies on Gd 2 Zr 2-x Ti x O 7 pyrochlore materials. For Y 2 Ti 2 O 7 , this effect is attributed to the significantly lower electron density of this material relative to the lanthanide-bearing pyrochlores, thus lowering the electronic energy loss (dE/dx) of the high-energy ions in this composition. An energy loss normalization procedure was performed which reveals an initial increase of amorphous track size with r A /r B that saturates above a cation radius ratio larger than Gd 2 Ti 2 O 7 . This is in agreement with previous low-energy ion irradiation experiments and first principles calculations of the disordering energy of titanate pyrochlores indicating that the same trends in disordering energy apply to radiation damage induced in both the nuclear and electronic energy loss regimes. HRTEM images indicate that single ion tracks in Yb 2 Ti 2 O 7 and Er 2 Ti 2 O 7 , which have small A-site cations and low r A /r B , exhibit a core-shell structure with a small amorphous core surrounded by a larger disordered shell. In contrast, single tracks in Gd 2 Ti 2 O 7 and Sm 2 Ti 2 O 7 , have a larger amorphous core with minimal disordered shells.

  8. Irradiation effects of swift heavy ions in matter

    Energy Technology Data Exchange (ETDEWEB)

    Osmani, Orkhan

    2011-12-22

    In the this thesis irradiation effects of swift heavy ions in matter are studied. The focus lies on the projectiles charge exchange and energy loss processes. A commonly used computer code which employs rate equations is the so called ETACHA code. This computer code is capable to also calculate the required input cross-sections. Within this thesis a new model to compute the charge state of swift heavy ions is explored. This model, the so called matrix method, takes the form of a simple algebraic expression, which also requires cross-sections as input. In the present implementation of the matrix method, cross-sections are taken from the ETACHA code, while excitation and deexcitation processes are neglected. Charge fractions for selected ion/target combinations, computed by the ETACHA code and the matrix method are compared. It is shown, that for sufficient large ion energies, both methods agree very well with each other. However, for lower energies pronounced differences are observed. These differences are believed to stem from the fact, that no excited states as well as the decay of theses excited states are included in the present implementation of the matrix method. Both methods are then compared with experimental measurements, where significant deviations are observed for both methods. While the predicted equilibrium charge state by both methods is in good agreement with the experiments, the matrix method predicts a much too large equilibrium thickness compared to both the ETACHA calculation as well as the experiment. Again, these deviations are believed to stem from the fact, that excitation and the decay of excited states are not included in the matrix method. A possible way to include decay processes into the matrix method is presented, while the accuracy of the applied capture cross-sections is tested by comparison with scaling rules. Swift heavy ions penetrating a dielectric are known to induced structural modifications both on the surface and in the bulk

  9. Irradiation effects of swift heavy ions in matter

    International Nuclear Information System (INIS)

    Osmani, Orkhan

    2011-01-01

    In the this thesis irradiation effects of swift heavy ions in matter are studied. The focus lies on the projectiles charge exchange and energy loss processes. A commonly used computer code which employs rate equations is the so called ETACHA code. This computer code is capable to also calculate the required input cross-sections. Within this thesis a new model to compute the charge state of swift heavy ions is explored. This model, the so called matrix method, takes the form of a simple algebraic expression, which also requires cross-sections as input. In the present implementation of the matrix method, cross-sections are taken from the ETACHA code, while excitation and deexcitation processes are neglected. Charge fractions for selected ion/target combinations, computed by the ETACHA code and the matrix method are compared. It is shown, that for sufficient large ion energies, both methods agree very well with each other. However, for lower energies pronounced differences are observed. These differences are believed to stem from the fact, that no excited states as well as the decay of theses excited states are included in the present implementation of the matrix method. Both methods are then compared with experimental measurements, where significant deviations are observed for both methods. While the predicted equilibrium charge state by both methods is in good agreement with the experiments, the matrix method predicts a much too large equilibrium thickness compared to both the ETACHA calculation as well as the experiment. Again, these deviations are believed to stem from the fact, that excitation and the decay of excited states are not included in the matrix method. A possible way to include decay processes into the matrix method is presented, while the accuracy of the applied capture cross-sections is tested by comparison with scaling rules. Swift heavy ions penetrating a dielectric are known to induced structural modifications both on the surface and in the bulk

  10. Opto-chemical response of Makrofol-KG to swift heavy ion irradiation

    Indian Academy of Sciences (India)

    In the present study, the effects of swift heavy ion beam irradiation on the structural, chemical and optical properties of Makrofol solid-state nuclear track detector (SSNTD) were investigated. Makrofol-KG films of 40 m thickness were irradiated with oxygen beam (8+) with fluences ranging between 1010 ion/cm2 and 1012 ...

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

  13. Effect of swift heavy ion irradiation on ethylene–chlorotrifluoroethylene copolymer

    International Nuclear Information System (INIS)

    Singh, Lakhwant; Devgan, Kusum; Samra, Kawaljeet Singh

    2012-01-01

    The swift heavy irradiation induced changes taking place in ethylene–chlorotrifluoroethylene (E–CTFE) copolymer films were investigated in correlation with the applied doses. Samples were irradiated in vacuum at room temperature by lithium (50 MeV), carbon (85 MeV), nickel (120 MeV) and silver (120 MeV) ions with the fluence in the range of 1×10 11 –3×10 12 ions cm −2 . Structural and thermal properties of the irradiated as well as pristine E–CTFE films were studied using FTIR, UV–visible, TGA, DSC and XRD techniques. Swift heavy ion irradiation was found to induce changes in E–CTFE depending upon the applied doses. - Highlights: ► Effect of swift heavy ion irradiation on E–CTFE films has been studied. ► Different structural changes in the original structure of E–CTFE are observed after irradiation with different ions. ► Swift heavy ion irradiation has made E–CTFE more prone to thermal degradation.

  14. Positron lifetime and Doppler broadening study of defects created by swift ion irradiation in sapphire

    International Nuclear Information System (INIS)

    Liszkay, L.; Gordo, P.M.; Lima, A. de; Havancsak, K.; Skuratov, V.A.; Kajcsos, Z.

    2004-01-01

    Swift ions create a defect profile penetrating deep into a solid compared to the sampling range of typical slow positron beams, which may consequently study a homogeneous zone of defected materials. To investigate the defect population created by energetic ions, we studied α-Al 2 O 3 single crystals irradiated with swift Kr ions by using conventional and pulsed positron beams. Samples irradiated with krypton at 245 MeV energy in a wide fluence range show nearly saturated positron trapping above 5 x 10 10 ions cm -2 fluence, indicating the creation of monovacancies in high concentration. At 1 x 10 14 ions cm -2 irradiation a 500 ps long lifetime component appears, showing the creation of larger voids. This threshold corresponds well to the onset of the overlap of the damage zones after Bi ion irradiation along the ion trajectories observed with microscopic methods. (orig.)

  15. Swift heavy ion irradiation induced modification of structure and ...

    Indian Academy of Sciences (India)

    1Department of Physics, Salipur College, Salipur 754 103, India. 2Department of ... Ion irradiation; nanoparticles; atomic force microscopy; BiFeO3. 1. Introduction .... and to understand their possible origin, a study on power spectral density ...

  16. Oxide glass structure evolution under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Mendoza, C.; Peuget, S.; Charpentier, T.; Moskura, M.; Caraballo, R.; Bouty, O.; Mir, A.H.; Monnet, I.; Grygiel, C.; Jegou, C.

    2014-01-01

    Highlights: • Structure of SHI irradiated glass is similar to the one of a hyper quenched glass. • D2 Raman band associated to 3 members ring is only observed in irradiated glass. • Irradiated state seems slightly different to an equilibrated liquid quenched rapidly. - Abstract: The effects of ion tracks on the structure of oxide glasses were examined by irradiating a silica glass and two borosilicate glass specimens containing 3 and 6 oxides with krypton ions (74 MeV) and xenon ions (92 MeV). Structural changes in the glass were observed by Raman and nuclear magnetic resonance spectroscopy using a multinuclear approach ( 11 B, 23 Na, 27 Al and 29 Si). The structure of irradiated silica glass resembles a structure quenched at very high temperature. Both borosilicate glass specimens exhibited depolymerization of the borosilicate network, a lower boron coordination number, and a change in the role of a fraction of the sodium atoms after irradiation, suggesting that the final borosilicate glass structures were quenched from a high temperature state. In addition, a sharp increase in the concentration of three membered silica rings and the presence of large amounts of penta- and hexacoordinate aluminum in the irradiated 6-oxide glass suggest that the irradiated glass is different from a liquid quenched at equilibrium, but it is rather obtained from a nonequilibrium liquid that is partially relaxed by very rapid quenching within the ion tracks

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

    International Nuclear Information System (INIS)

    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

  18. Structural modifications of swift heavy ion irradiated PEN probed by optical and thermal measurements

    International Nuclear Information System (INIS)

    Devgan, Kusum; Singh, Lakhwant; Samra, Kawaljeet Singh

    2013-01-01

    Highlights: • The present paper reports the effect of swift heavy ion irradiation on Polyethylene Naphthalate (PEN). • Swift heavy ion irradiation introduces structural modification and degradation of PEN at different doses. • Lower irradiation doses in PEN result in modification of structural properties and higher doses lead to complete degradation. • Strong correlation between structural, optical, and thermal properties. - Abstract: The effects of swift heavy ion irradiation on the structural characteristics of Polyethylene naphthalate (PEN) were studied. Samples were irradiated in vacuum at room temperature by lithium (50 MeV), carbon (85 MeV), nickel (120 MeV) and silver (120 MeV) ions with the fluence in the range of 1×10 11 –3×10 12 ions cm −2 . Ion induced changes were analyzed using X-ray diffraction (XRD), Fourier transform infra red (FT-IR), UV–visible spectroscopy, thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Cross-linking was observed at lower doses resulting in modification of structural properties, however higher doses lead to the degradation of the investigated polymeric samples

  19. Saturation of plastic deformation by swift heavy ion irradiation: Ion hammering vs. surface effects

    Energy Technology Data Exchange (ETDEWEB)

    Ferhati, Redi; Dautel, Knut; Bolse, Wolfgang [Institut fuer Halbleiteroptik und Funktionelle Grenzflaechen, Universitaet Stuttgart (Germany); Fritzsche, Monika [Helmholtz-Zentrum Dresden-Rossendorf (Germany)

    2012-07-01

    Swift heavy ion (SHI) induced plastic deformation is a subject of current research and scientific discussion. This *Ion Hammering* phenomenon was first observed 30 years ago in amorphous materials like metallic glasses. About 10 years ago, Feyh et al. have shown that stress generation and *Ion Hammering* result in self-organization of thin NiO-films on Si-wafers into a sub-micron lamellae-like structure under grazing angle irradiation. The growth of the lamellae was found to saturate as soon as they have reached a thickness of a few hundreds of nm. Here we show our latest results on the restructuring of pre-patterned thin oxide films by SHI under various irradiation conditions. The experiments were performed by employing (in-situ) scanning electron microscopy, and were complemented by (in-situ) energy dispersive x-ray analysis and atomic force microscopy. As we will show, the saturation behavior can be understood as a competition of *Ion Hammering* and surface energy effects, while the unexpected fact, that the initially crystalline films undergo *Ion Hammering* can possibly be attributed to oxygen loss and thus amorphization during irradiation.

  20. Tuning the conductivity of vanadium dioxide films on silicon by swift heavy ion irradiation

    Directory of Open Access Journals (Sweden)

    H. Hofsäss

    2011-09-01

    Full Text Available We demonstrate the generation of a persistent conductivity increase in vanadium dioxide thin films grown on single crystal silicon by irradiation with 1 GeV 238U swift heavy ions at room temperature. VO2 undergoes a temperature driven metal-insulator-transition (MIT at 67 °C. After room temperature ion irradiation with high electronic energy loss of 50 keV/nm the conductivity of the films below the transition temperature is strongly increased proportional to the ion fluence of 5·109 U/cm2 and 1·1010 U/cm2. At high temperatures the conductivity decreases slightly. The ion irradiation slightly reduces the MIT temperature. This observed conductivity change is persistent and remains after heating the samples above the transition temperature and subsequent cooling. Low temperature measurements down to 15 K show no further MIT below room temperature. Although the conductivity increase after irradiation at such low fluences is due to single ion track effects, atomic force microscopy (AFM measurements do not show surface hillocks, which are characteristic for ion tracks in other materials. Conductive AFM gives no evidence for conducting ion tracks but rather suggests the existence of conducting regions around poorly conducting ion tracks, possible due to stress generation. Another explanation of the persistent conductivity change could be the ion-induced modification of a high resistivity interface layer formed during film growth between the vanadium dioxide film and the n-Silicon substrate. The swift heavy ions may generate conducting filaments through this layer, thus increasing the effective contact area. Swift heavy ion irradiation can thus be used to tune the conductivity of VO2 films on silicon substrates.

  1. Graphite irradiated by swift heavy ions under grazing incidence

    CERN Document Server

    Liu, J; Müller, C; Neumann, R

    2002-01-01

    Highly oriented pyrolytic graphite is irradiated with various heavy projectiles (Ne, Ni, Zn, Xe and U) in the MeV to GeV energy range under different oblique angles of incidence. Using scanning tunneling microscopy, the impact zones are imaged as hillocks protruding from the surface. The diameter of surface-grazing tracks varies between 3 nm (Ne) and 6 nm (U), which is about twice as large as under normal beam incidence. Exclusively for U and Xe projectiles, grazing tracks exhibit long comet-like tails consisting of successive little bumps indicating that the damage along the ion path is discontinuous even for highest electronic stopping powers.

  2. Role of the irradiation temperature on the modifications of swift-heavy-ion irradiated polyethylene

    International Nuclear Information System (INIS)

    Melot, M.; Ngono-Ravache, Y.; Balanzat, E.

    2003-01-01

    The damage processes triggered by swift heavy ions, SHI, can be very different to those induced by classical low ionising particles. This is due to the very high electronic stopping power, (dE/dx) e , of SHI. This paper concerns the effects of SHI on polyethylene, PE. In PE, low (dE/dx) e irradiations induce crosslinking and in-chain double bond formation. At high (dE/dx) e , the creation yield of vinyl groups becomes significant. Above a (dE/dx) e threshold, alkyne and allene groups appear. We present results on low temperature irradiations that bring new enlightenment on the damage process by preventing the migration of radiation-induced radicals and molecules. Two SHI specific modifications are studied: vinyl groups and alkyne end groups. We have irradiated PE films with oxygen and sulphur beams at 13.6 and 11.2 MeV/amu, respectively. The modifications were followed by in situ infrared spectroscopy (FTIR). We have performed irradiations at 8 and 290 K. The samples irradiated at 8 K have been annealed up to 290 K for investigating the effect of radical migration. Lowering the irradiation temperature to 8 K increases the creation yield of vinyl groups and alkyne end groups. The enhancement factor between 290 and 8 K is around three. Consequently the formation of defects specific to SHI irradiations is sensitive to radical migration and hence requires some time. During annealing, the alkyne concentration remains stable indicating that the creation of this group cannot be induced by radical recombination. The annealing spectra of vinyl groups are more complex

  3. Irradiation effects of swift heavy ions on gallium arsenide, silicon and silicon diodes

    International Nuclear Information System (INIS)

    Bhoraskar, V.N.

    2001-01-01

    The irradiation effects of high energy lithium, boron, oxygen and silicon ions on crystalline silicon, gallium arsenide, porous silicon and silicon diodes were investigated. The ion energy and fluence were varied over the ranges 30 to 100 MeV and 10 11 to 10 14 ions/cm 2 respectively. Semiconductor samples were characterized with the x-ray fluorescence, photoluminescence, thermally stimulated exo-electron emission and optical reflectivity techniques. The life-time of minority carriers in crystalline silicon was measured with a pulsed electron beam and the lithium depth distribution in GaAs was measured with the neutron depth profiling technique. The diodes were characterized through electrical measurements. The results of optical reflectivity, life-time of minority carriers and photoluminescence show that swift heavy ions induce defects in the surface region of crystalline silicon. In the ion-irradiated GaAs, migration of silicon, oxygen and lithium atoms from the buried region towards the surface was observed, with orders of magnitude enhancement in the diffusion coefficients. Enhancement in the photoluminescence intensity was observed in the GaAs and porous silicon samples that, were irradiated with silicon ions. The trade-off between the turn-off time and the voltage, drop in diodes irradiated with different swift heavy ions was also studied. (author)

  4. Hydration effect on ion exchange resin irradiated by swift heavy ions and gamma rays

    Science.gov (United States)

    Boughattas, I.; Labed, V.; Gerenton, A.; Ngono-Ravache, Y.; Dannoux-Papin, A.

    2018-06-01

    Gamma radiolysis of ion exchange resins (IER) is widely studied since the sixties, as a function of different parameters (resin type, dose, atmosphere, water content …). However, to our knowledge, there are very few data concerning hydrogen emission from anionic and cationic resins irradiated at high Linear Energy Transfers (LET). In the present work, we focus on the influence of hydration on hydrogen emission, in anionic and cationic resins irradiated under inert atmosphere using Swift Heavy Ions (SHI) and gamma irradiations. The radiation chemical yield of molecular hydrogen is nonlinear with water content for both resins. The molecular hydrogen production depends first on the water form in IER (free or linked) and second on the solubility of degradation products. Three steps have been observed: at lower water content where G(H2) is stable, at 50%, G(H2) increases due to reactions between water radiolytic species and the resin functional groups and at high water content, G(H2) decreases probably due to its accumulation in water and its consumption by hydroxyl radicals in the supernatant.

  5. Effect of swift heavy ion irradiation on surface resistance of DyBa 2

    Indian Academy of Sciences (India)

    We report the observation of a pronounced peak in surface resistance at microwave frequencies of 4.88 GHz and 9.55 GHz and its disappearance after irradiation with swift ions in laser ablated DyBa2Cu3O7- (DBCO) thin films. The measurements were carried out in zero field as well as in the presence of magnetic fields ...

  6. Engineering of electronic properties of single layer graphene by swift heavy ion irradiation

    Science.gov (United States)

    Kumar, Sunil; Kumar, Ashish; Tripathi, Ambuj; Tyagi, Chetna; Avasthi, D. K.

    2018-04-01

    In this work, swift heavy ion irradiation induced effects on the electrical properties of single layer graphene are reported. The modulation in minimum conductivity point in graphene with in-situ electrical measurement during ion irradiation was studied. It is found that the resistance of graphene layer decreases at lower fluences up to 3 × 1011 ions/cm2, which is accompanied by the five-fold increase in electron and hole mobilities. The ion irradiation induced increase in electron and hole mobilities at lower fluence up to 1 × 1011 ions/cm2 is verified by separate Hall measurements on another irradiated graphene sample at the selected fluence. In contrast to the adverse effects of irradiation on the electrical properties of materials, we have found improvement in electrical mobility after irradiation. The increment in mobility is explained by considering the defect annealing in graphene after irradiation at a lower fluence regime. The modification in carrier density after irradiation is also observed. Based on findings of the present work, we suggest ion beam irradiation as a useful tool for tuning of the electrical properties of graphene.

  7. Effect of swift heavy ion irradiation on bare and coated ZnS quantum dots

    International Nuclear Information System (INIS)

    Chowdhury, S.; Hussain, A.M.P.; Ahmed, G.A.; Singh, F.; Avasthi, D.K.; Choudhury, A.

    2008-01-01

    The present study compares structural and optical modifications of bare and silica (SiO 2 ) coated ZnS quantum dots under swift heavy ion (SHI) irradiation. Bare and silica coated ZnS quantum dots were prepared following an inexpensive chemical route using polyvinyl alcohol (PVA) as the dielectric host matrix. X-ray diffraction (XRD) and transmission electron microscopy (TEM) study of the samples show the formation of almost spherical ZnS quantum dots. The UV-Vis absorption spectra reveal blue shift relative to bulk material in absorption energy while photoluminescence (PL) spectra suggests that surface state and near band edge emissions are dominating in case of bare and coated samples, respectively. Swift heavy ion irradiation of the samples was carried out with 160 MeV Ni 12+ ion beam with fluences 10 12 to 10 13 ions/cm 2 . Size enhancement of bare quantum dots after irradiation has been indicated in XRD and TEM analysis of the samples which has also been supported by optical absorption spectra. However similar investigations on irradiated coated quantum dots revealed little change in quantum dot size and emission. The present study thus shows that the coated ZnS quantum dots are stable upon SHI irradiation compared to the bare one

  8. Swift heavy ion irradiation effects in Pt/C and Ni/C multilayers

    Science.gov (United States)

    Gupta, Ajay; Pandita, Suneel; Avasthi, D. K.; Lodha, G. S.; Nandedkar, R. V.

    1998-12-01

    Irradiation effects of 100 MeV Ag ion irradiation on Ni/C and Pt/C multilayers have been studied using X-ray reflectivity measurements. Modifications are observed in both the multilayers at (dE/dx)e values much below the threshold values for Ni and Pt. This effect is attributed to the discontinuous nature of the metal layers. In both the multilayers interfacial roughness increases with irradiation dose. While Ni/C multilayers exhibit large ion-beam induced intermixing, no observable intermixing is observed in the case of Pt/C multilayer. This difference in the behavior of the two systems suggests a significant role for chemically guided defect motion in the mixing process associated with swift heavy ion irradiation.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Refractive index dispersion of swift heavy ion irradiated BFO thin films using Surface Plasmon Resonance technique

    International Nuclear Information System (INIS)

    Paliwal, Ayushi; Sharma, Savita; Tomar, Monika; Singh, Fouran; Gupta, Vinay

    2016-01-01

    Highlights: • Investigated the optical properties of BiFeO_3 (BFO) thin films after irradiation using SPR. • Otto configuration has been used to excite the surface plasmons using gold metal thin film. • BFO thin films were prepared by sol–gel spin coating technique. • Examined the refractive index dispersion of pristine and irradiated BFO thin film. - Abstract: Swift heavy ion irradiation (SHI) is an effective technique to induce defects for possible modifications in the material properties. There is growing interest in studying the optical properties of multiferroic BiFeO_3 (BFO) thin films for optoelectronic applications. In the present work, BFO thin films were prepared by sol–gel spin coating technique and were irradiated using the 15 UD Pelletron accelerator with 100 MeV Au"9"+ ions at a fluence of 1 × 10"1"2 ions cm"−"2. The as-grown films became rough and porous on ion irradiation. Surface Plasmon Resonance (SPR) technique has been identified as a highly sensitive and powerful technique for studying the optical properties of a dielectric material. Optical properties of BFO thin films, before and after irradiation were studied using SPR technique in Otto configuration. Refractive index is found to be decreasing from 2.27 to 2.14 on ion irradiation at a wavelength of 633 nm. Refractive index dispersion of BFO thin film (from 405 nm to 633 nm) before and after ion radiation was examined.

  11. Refractive index dispersion of swift heavy ion irradiated BFO thin films using Surface Plasmon Resonance technique

    Energy Technology Data Exchange (ETDEWEB)

    Paliwal, Ayushi [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Sharma, Savita [Department of Applied Physics, Delhi Technological University, Delhi (India); Tomar, Monika [Physics Department, Miranda House, University of Delhi, Delhi 110007 (India); Singh, Fouran [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110075 (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2016-07-15

    Highlights: • Investigated the optical properties of BiFeO{sub 3} (BFO) thin films after irradiation using SPR. • Otto configuration has been used to excite the surface plasmons using gold metal thin film. • BFO thin films were prepared by sol–gel spin coating technique. • Examined the refractive index dispersion of pristine and irradiated BFO thin film. - Abstract: Swift heavy ion irradiation (SHI) is an effective technique to induce defects for possible modifications in the material properties. There is growing interest in studying the optical properties of multiferroic BiFeO{sub 3} (BFO) thin films for optoelectronic applications. In the present work, BFO thin films were prepared by sol–gel spin coating technique and were irradiated using the 15 UD Pelletron accelerator with 100 MeV Au{sup 9+} ions at a fluence of 1 × 10{sup 12} ions cm{sup −2}. The as-grown films became rough and porous on ion irradiation. Surface Plasmon Resonance (SPR) technique has been identified as a highly sensitive and powerful technique for studying the optical properties of a dielectric material. Optical properties of BFO thin films, before and after irradiation were studied using SPR technique in Otto configuration. Refractive index is found to be decreasing from 2.27 to 2.14 on ion irradiation at a wavelength of 633 nm. Refractive index dispersion of BFO thin film (from 405 nm to 633 nm) before and after ion radiation was examined.

  12. Structural stability of C60 films under irradiation with swift heavy ions

    International Nuclear Information System (INIS)

    Jin Yunfan; Yao Cunfeng; Wang Zhiguang; Xie Erqing; Song Yin; Sun Youmei; Zhang Chonghong; Liu Jie; Duan Jinglai

    2005-01-01

    In order to investigate the structural stability of fullerene (C 60 ) under swift heavy ion irradiation, the irradiation experiments of thin C 60 films were performed with 22 MeV/amu Fe 56 ions delivered by HIRFL at Lanzhou in China. The irradiated C 60 films were analyzed by means of Raman scattering and Fourier transform infrared (FTIR) spectroscopes. The analysis results indicated that the damage cross-sections σ of the C 60 molecule deduced from the data of the Raman spectra are between 1.1 and 4.5 x 10 -14 cm 2 for the electronic energy loss from 3.5 to 8.7 keV/nm and electronic energy transfer dominates the damage process of C 60 films. The partial recovery of the damage in irradiated C 60 films at certain electronic energy loss is attributed to an annealing effect of strong electronic excitation

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

    Institute of Scientific and Technical Information of China (English)

    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.

  14. Characterization of biodegradable polymers irradiated with swift heavy ions

    International Nuclear Information System (INIS)

    Salguero, N.G.; Grosso, M.F. del; Durán, H.; Peruzzo, P.J.; Amalvy, J.I.

    2012-01-01

    In view of their application as biomaterials, there is an increasing interest in developing new methods to induce controlled cell adhesion onto polymeric materials. The critical step in all these methods involves the modification of polymer surfaces, to induce cell adhesion, without changing theirs degradation and biocompatibility properties. In this work two biodegradable polymers, polyhydroxybutyrate (PHB) and poly-L-lactide acid (PLLA) were irradiated using carbon and sulfur beams with different energies and fluences. Pristine and irradiated samples were degradated by immersion in a phosphate buffer at pH 7.0 and then characterized. The analysis after irradiation and degradation showed a decrease in the contact angle values and changes in their crystallinity properties.

  15. Characterization of biodegradable polymers irradiated with swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Salguero, N.G. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Grosso, M.F. del, E-mail: delgrosso@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917 C1033AAJ CABA (Argentina); Duran, H. [CONICET, Av. Rivadavia 1917 C1033AAJ CABA (Argentina); Gerencia de Desarrollo Tecnologico y Proyectos Especiales, CNEA, Av. Gral. Paz 1499 (B1650KNA) San Mart Latin-Small-Letter-Dotless-I Acute-Accent n, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, H. Yrigoyen 3100, CP 1650, San Martin, UNSAM (Argentina); Peruzzo, P.J. [CICPBA - Grupo de Materiales y Nanomateriales Polimericos, Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), CCT La Plata CONICET - Universidad Nacional de La Plata, La Plata (Argentina); Amalvy, J.I. [CICPBA - Grupo de Materiales y Nanomateriales Polimericos, Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), CCT La Plata CONICET - Universidad Nacional de La Plata, La Plata (Argentina); Facultad de Ingenieria, Universidad Nacional de La Plata, Calle 116 y 48 (B1900TAG), La Plata (Argentina); Departamento de Ingenieria Quimica, Facultad Regional La Plata, Universidad Tecnologica Nacional, 60 y 124 (1900), La Plata (Argentina); and others

    2012-02-15

    In view of their application as biomaterials, there is an increasing interest in developing new methods to induce controlled cell adhesion onto polymeric materials. The critical step in all these methods involves the modification of polymer surfaces, to induce cell adhesion, without changing theirs degradation and biocompatibility properties. In this work two biodegradable polymers, polyhydroxybutyrate (PHB) and poly-L-lactide acid (PLLA) were irradiated using carbon and sulfur beams with different energies and fluences. Pristine and irradiated samples were degradated by immersion in a phosphate buffer at pH 7.0 and then characterized. The analysis after irradiation and degradation showed a decrease in the contact angle values and changes in their crystallinity properties.

  16. Swift heavy ion irradiation induced modification of structure

    Indian Academy of Sciences (India)

    AFM analysis indicated that the pristine film consists of agglomerated grains with diffuse grain boundary. Irradiation led to reduced agglomeration of the grains with the formation of sharper grain boundaries. The rms roughness (rms) estimated from AFM analysis increased from 6.2 in pristine film to 12.7 nm when the film ...

  17. Refractive index dispersion of swift heavy ion irradiated BFO thin films using Surface Plasmon Resonance technique

    Science.gov (United States)

    Paliwal, Ayushi; Sharma, Savita; Tomar, Monika; Singh, Fouran; Gupta, Vinay

    2016-07-01

    Swift heavy ion irradiation (SHI) is an effective technique to induce defects for possible modifications in the material properties. There is growing interest in studying the optical properties of multiferroic BiFeO3 (BFO) thin films for optoelectronic applications. In the present work, BFO thin films were prepared by sol-gel spin coating technique and were irradiated using the 15 UD Pelletron accelerator with 100 MeV Au9+ ions at a fluence of 1 × 1012 ions cm-2. The as-grown films became rough and porous on ion irradiation. Surface Plasmon Resonance (SPR) technique has been identified as a highly sensitive and powerful technique for studying the optical properties of a dielectric material. Optical properties of BFO thin films, before and after irradiation were studied using SPR technique in Otto configuration. Refractive index is found to be decreasing from 2.27 to 2.14 on ion irradiation at a wavelength of 633 nm. Refractive index dispersion of BFO thin film (from 405 nm to 633 nm) before and after ion radiation was examined.

  18. In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Kulriya, P.K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A.K.; Avasthi, D.K.

    2015-01-01

    An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd 2 Ti 2 O 7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd 2 Ti 2 O 7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd 2 Ti 2 O 7 is readily amorphized at an ion fluence 6 × 10 12 ions/cm 2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 10 13 ions/cm 2 . The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures

  19. Capillaric penetration of etchant solution into swift heavy ion-irradiated silicone rubber

    International Nuclear Information System (INIS)

    Fink, D.; Mueller, M.

    2000-01-01

    There is growing evidence that etchants penetrate into latent ion tracks in polymers from the very beginning, i.e., even during the so-called 'incubation time' when no visible etchant attack is observed. The model of capillaric penetration of viscous liquids into sponge-like matter agrees with experimental values both in their parametric dependence as in the absolute values. Our experiments are based on LiOH etching of both pristine and swift heavy ion-irradiated silicone rubber foils. About five times more etchant penetrates into irradiated than into pristine silicone rubber. The overall etchant penetration is highest in tracks parallel to the surface normal, and decreases with increasing ion track tilt angle towards the surface normal. The etchant penetration into the tracks proceeds relatively slowly with an effective viscosity comparable to that of heavy machine oil. When swelling starts to predominate, the maximum etchant penetration depth comes to saturation, with the total etchant uptake even decreasing

  20. Quartz modification by Zn ion implantation and swift Xe ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Privezentsev, Vladimir [Institute of Physics and Technology, Russian Academy of Sciences, Moscow (Russian Federation); Kulikauskas, Vaclav [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University (Russian Federation); Didyk, Alexander; Skuratov, Vladimir [Joint Institute of Nuclear Research, Dubna (Russian Federation); Steinman, Edward; Tereshchenko, Alexey; Kolesnikov, Nikolay [Institute of Solid-State Physics, Russian Academy of Sciences, Chernogolovka (Russian Federation); Trifonov, Alexey; Sakharov, Oleg [National Research University ' ' MIET' ' , Zelenograd, Moscow (Russian Federation); Ksenich, Sergey [National University of Science and Technology ' ' MISiS' ' , Moscow (Russian Federation)

    2017-07-15

    The quartz slides were implanted by {sup 64}Zn{sup +} ions with dose of 5 x 10{sup 16}/cm{sup 2} and energy of 100 keV. After implantation, the amorphous metallic Zn nanoparticles with an average radius of 3.5 nm were created. The sample surface becomes nonuniform, its roughness is increased and its values rise up to 6 nm compared to virgin state, and the roughness maximum is at a value of about 0.8 nm. The surface is made up of valleys and hillocks which have a round shape with an average diameter about 200 nm. At the center of these hillocks are pores with a depth up to 6 nm and a diameter of about 20 nm. After implantation in UV-vis diapason, the optical transmission decreases while PL peak (apparently due to oxygen deficient centers) at wavelength of 400 nm increases. Then the samples were subjected to swift Xe ion irradiation with the fluences of 1 x 10{sup 12}-7.5 x 10{sup 14}/cm{sup 2} and energy of 167 MeV. After Xe irradiation, the sample surface roughness shat down to values of 0.5 nm and the roughness maximum is at a value of about 0.1 nm. Optical transmission in UV-vis diapason increases. The PL peak at wavelength of 400 nm is decreased while a PL peak at wavelength of 660 nm is raised. This peak is presumably due to non-bridging oxygen hole centers or/and NPs with structure Si(core)/SiO{sub 2}(shell). HRTEM image of Zn-implanted quartz subsurface layer. One can see the Zn amorphous nanoparticles, which confirms the electron diffraction pattern (insert). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Study on interaction of swift cluster ion beam with matter and irradiation effect (Joint research)

    International Nuclear Information System (INIS)

    Saito, Yuichi; Shibata, Hiromi

    2010-07-01

    This review covers results of the 'Study of interaction on swift cluster ion beam with matter and irradiation effect' supported by the Interorganization Atomic Energy Research Program from 2006FY to 2008FY. It is composed of a research abstract for each sub-group with viewgraphs which were presented at the group meeting held on March 2009 or 'Meeting of High LET radiation -From fundamental study among physics, chemistry and biology to medical applications-' sponsored by Japan Society of Radiation Chemistry, cosponsored by this research group. (author)

  2. Swift heavy ion irradiation of Cu-Zn-Al and Cu-Al-Ni alloys.

    Science.gov (United States)

    Zelaya, E; Tolley, A; Condo, A M; Schumacher, G

    2009-05-06

    The effects produced by swift heavy ions in the martensitic (18R) and austenitic phase (β) of Cu based shape memory alloys were characterized. Single crystal samples with a surface normal close to [210](18R) and [001](β) were irradiated with 200 MeV of Kr(15+), 230 MeV of Xe(15+), 350 and 600 MeV of Au(26+) and Au(29+). Changes in the microstructure were studied with transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). It was found that swift heavy ion irradiation induced nanometer sized defects in the 18R martensitic phase. In contrast, a hexagonal close-packed phase formed on the irradiated surface of β phase samples. HRTEM images of the nanometer sized defects observed in the 18R martensitic phase were compared with computer simulated images in order to interpret the origin of the observed contrast. The best agreement was obtained when the defects were assumed to consist of local composition modulations.

  3. Raman spectroscopic investigations of swift heavy ion irradiation effects in single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Olejniczak, A.; Skuratov, V.A.; Lukaszewicz, J.P.

    2013-01-01

    In this study, we report the results on swift heavy ion irradiation effects in single-walled carbon nanotubes (SWNTs). Buckypapers, prepared of CVD grown, SWNTs were irradiated at room temperature with 167 MeV Xe ions to fluences in the range of 6×10 11 - 6.5×10 13 cm -2 and investigated using Raman spectroscopy. We observed a rich set of features in the intermediate frequency mode region. Some of them, being defect-induced, resembled fairly well the phonon density of states (DOS) of nanocrystalline glassy carbon. Analysis of the RBM modes has shown that the broader metallic tubes are characterized by higher radiation stability than thinner semiconducting ones. (authors)

  4. Optical waveguides in LiTaO3 crystals fabricated by swift C5+ ion irradiation

    International Nuclear Information System (INIS)

    Liu, Guiyuan; He, Ruiyun; Akhmadaliev, Shavkat; Vázquez de Aldana, Javier R.; Zhou, Shengqiang; Chen, Feng

    2014-01-01

    We report on the optical waveguides, in both planar and ridge configurations, fabricated in LiTaO 3 crystal by using carbon (C 5+ ) ions irradiation at energy of 15 MeV. The planar waveguide was produced by direct irradiation of swift C 5+ ions, whilst the ridge waveguides were manufactured by using femtosecond laser ablation of the planar layer. The reconstructed refractive index profile of the planar waveguide has showed a barrier-shaped distribution, and the near-field waveguide mode intensity distribution was in good agreement with the calculated modal profile. After thermal annealing at 260 °C in air, the propagation losses of both the planar and ridge waveguides were reduced to 10 dB/cm

  5. Surface modifications caused by a swift heavy ion irradiation on crystalline p-type gallium antimonide

    Science.gov (United States)

    Jadhav, Vidya

    2015-09-01

    Surface modifications caused by a swift heavy ion irradiation on crystalline p-type gallium antimonide crystal have been reported. Single crystal, 1 0 0> orientations and ∼500 μm thick p-type GaSb samples with carrier concentration of 3.30 × 1017 cm-3 were irradiated at 100 MeV Fe7+ ions. We have used 15UD Pelletron facilities at IUAC with varying fluences of 5 × 1010-1 × 1014 ions cm-2. The effects of irradiation on these samples have been investigated using, spectroscopic ellipsometry, atomic force microscopy and ultraviolet-visible-NIR spectroscopy techniques. Ellipsometry parameters, psi (Ψ) and delta (Δ) for the unirradiated sample and samples irradiated with different fluences were recorded. The data were fit to a three phase model to determine the refractive index and extinction coefficient. The refractive index and extinction coefficient for various fluences in ultraviolet, visible, and infrared, regimes were evaluated. Atomic force microscopy has been used to study these surface modifications. In order to have more statistical information about the surface, we have plotted the height structure histogram for all the samples. For unirradiated sample, we observed the Gaussian fitting. This result indicates the more ordered height structure symmetry. Whereas for the sample irradiated with the fluence of 1 × 1013, 5 × 1013 and 1 × 1014 ions cm-2, we observed the scattered data. The width of the histogram for samples irradiated up to the fluence of 1 × 1013 ion cm-2 was found to be almost same however it decreased at higher fluence. UV reflectance spectra of the sample irradiated with increasing fluences exhibit three peaks at 292, 500 and 617 nm represent the high energy GaSb; E1, E1 + Δ and E2 band gaps in all irradiated samples.

  6. Surface modifications caused by a swift heavy ion irradiation on crystalline p-type gallium antimonide

    International Nuclear Information System (INIS)

    Jadhav, Vidya

    2015-01-01

    Surface modifications caused by a swift heavy ion irradiation on crystalline p-type gallium antimonide crystal have been reported. Single crystal, 1 0 0〉 orientations and ∼500 μm thick p-type GaSb samples with carrier concentration of 3.30 × 10 17 cm −3 were irradiated at 100 MeV Fe 7+ ions. We have used 15UD Pelletron facilities at IUAC with varying fluences of 5 × 10 10 –1 × 10 14 ions cm −2 . The effects of irradiation on these samples have been investigated using, spectroscopic ellipsometry, atomic force microscopy and ultraviolet–visible–NIR spectroscopy techniques. Ellipsometry parameters, psi (Ψ) and delta (Δ) for the unirradiated sample and samples irradiated with different fluences were recorded. The data were fit to a three phase model to determine the refractive index and extinction coefficient. The refractive index and extinction coefficient for various fluences in ultraviolet, visible, and infrared, regimes were evaluated. Atomic force microscopy has been used to study these surface modifications. In order to have more statistical information about the surface, we have plotted the height structure histogram for all the samples. For unirradiated sample, we observed the Gaussian fitting. This result indicates the more ordered height structure symmetry. Whereas for the sample irradiated with the fluence of 1 × 10 13 , 5 × 10 13 and 1 × 10 14 ions cm −2 , we observed the scattered data. The width of the histogram for samples irradiated up to the fluence of 1 × 10 13 ion cm −2 was found to be almost same however it decreased at higher fluence. UV reflectance spectra of the sample irradiated with increasing fluences exhibit three peaks at 292, 500 and 617 nm represent the high energy GaSb; E 1 , E 1 + Δ and E 2 band gaps in all irradiated samples

  7. Swift heavy ion irradiation of CaF2 - from grooves to hillocks in a single ion track

    Science.gov (United States)

    Gruber, Elisabeth; Salou, Pierre; Bergen, Lorenz; El Kharrazi, Mourad; Lattouf, Elie; Grygiel, Clara; Wang, Yuyu; Benyagoub, Abdenacer; Levavasseur, Delphine; Rangama, Jimmy; Lebius, Henning; Ban-d'Etat, Brigitte; Schleberger, Marika; Aumayr, Friedrich

    2016-10-01

    A novel form of ion-tracks, namely nanogrooves and hillocks, are observed on CaF2 after irradiation with xenon and lead ions of about 100 MeV kinetic energy. The irradiation is performed under grazing incidence (0.3°-3°) which forces the track to a region in close vicinity to the surface. Atomic force microscopy imaging of the impact sites with high spatial resolution reveals that the surface track consists in fact of three distinct parts: each swift heavy ion impacting on the CaF2 surface first opens a several 100 nm long groove bordered by a series of nanohillocks on both sides. The end of the groove is marked by a huge single hillock and the further penetration of the swift projectile into deeper layers of the target is accompanied by a single protrusion of several 100 nm in length slowly fading until the track vanishes. By comparing experimental data for various impact angles with results of a simulation, based on a three-dimensional version of the two-temperature-model (TTM), we are able to link the crater and hillock formation to sublimation and melting processes of CaF2 due to the local energy deposition by swift heavy ions.

  8. Optical waveguides in Nd:GdVO4 crystals fabricated by swift N3+ ion irradiation

    Science.gov (United States)

    Dong, Ningning; Yao, Yicun; Chen, Feng

    2012-12-01

    Optical planar waveguides have been manufactured in Nd:GdVO4 crystal by swift N3+ ions irradiation at fluence of 1.5 × 1014 ions/cm2. A typical "barrier"-style refractive index profile was formed and the light can be well confined in the waveguide region. The modal distribution of the guided modes obtained from numerical calculation has a good agreement with the experimental modal distribution. The measured photoluminescence spectra revealed that the fluorescence properties of the Nd3+ ions have been modified to some extent in the waveguide's volume. The propagation loss of the planar waveguide can decrease to lower than 1 dB/cm after adequate annealing.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

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

    2007-11-01

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

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

    Science.gov (United States)

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

    2007-11-01

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

  12. Swift heavy ion irradiation effects on carbonyl and trans-vinylene groups in high and low density polyethylene

    International Nuclear Information System (INIS)

    Grosso, M.F. del; Chappa, V.C.; Arbeitman, C.R.; Garcia Bermudez, G.; Behar, M.

    2009-01-01

    In this work, we have studied the effects of swift heavy ion irradiation on the creation of new functional groups in high and low density polyethylene (HDPE and LDPE). Polymers were irradiated with different ions (6.77 MeV He and 47 MeV Li) and fluences. The induced changes were analyzed by Fourier transform infrared (FTIR) spectroscopy. Creation and damage cross sections for some groups were compared for two different types of PE.

  13. Swift heavy ion irradiation effects on carbonyl and trans-vinylene groups in high and low density polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Grosso, M.F. del, E-mail: delgrosso@tandar.cnea.gov.a [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Chappa, V.C. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); CONICET (Argentina); Arbeitman, C.R. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Garcia Bermudez, G. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); CONICET (Argentina); Escuela de Ciencia y Tecnologia, UNSAM (Argentina); Behar, M. [Instituto de Fisica, UFRGS, Porto Alegre (Brazil)

    2009-10-01

    In this work, we have studied the effects of swift heavy ion irradiation on the creation of new functional groups in high and low density polyethylene (HDPE and LDPE). Polymers were irradiated with different ions (6.77 MeV He and 47 MeV Li) and fluences. The induced changes were analyzed by Fourier transform infrared (FTIR) spectroscopy. Creation and damage cross sections for some groups were compared for two different types of PE.

  14. Swift heavy ion irradiation effects in SiC measured by positrons

    Energy Technology Data Exchange (ETDEWEB)

    Liszkay, L.; Kajcsos, Zs.; Szilagyi, E. [KFKI Research Inst. for Nuclear and Particle Physics, Budapest (Hungary); Havancsak, K. [Dept. for Solid State Physics, Eoetvoes Univ., Budapest (Hungary); Barthe, M.F.; Desgardin, P.; Henry, L. [CNRS Centre d' Etudes et de Recherches par Irradiation, Orleans (France); Battistig, G. [Research Inst. for Technical Physics and Materials Science, Budapest (Hungary); Skuratov, V.A. [Joint Inst. of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics

    2001-07-01

    N-type 6H SiC single crystals irradiated with swift (246 MeV) Kr ions at room temperature (the implantation depth being 21 {mu}m) were investigated by conventional positron lifetime and Doppler-broadening measurements as well as with the application of a slow positron beam. The fluence dependence of the irradiation-induced defects was studied in the 1 x 10{sup 10} - 1 x 10{sup 14} ion cm{sup -2} range. In the fluence and depth range studied, no sign of amorphization (or creation of large voids) was seen in the Kr irradiated crystals. The positron annihilation results were compared with atomic displacement calculations by TRIM. A simple model was used to describe the trapping effect and determine the relationship between the atomic displacement densities and the positron trapping. The 225 ps lifetime of the open-volume defects created suggests that the V{sub Si}-V{sub C} divacancy is the dominant trapping site in the implanted zone. (orig.)

  15. Surface modifications caused by a swift heavy ion irradiation on crystalline p-type gallium antimonide

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, Vidya, E-mail: vj1510@yahoo.com

    2015-09-01

    Surface modifications caused by a swift heavy ion irradiation on crystalline p-type gallium antimonide crystal have been reported. Single crystal, 1 0 0〉 orientations and ∼500 μm thick p-type GaSb samples with carrier concentration of 3.30 × 10{sup 17} cm{sup −3} were irradiated at 100 MeV Fe{sup 7+} ions. We have used 15UD Pelletron facilities at IUAC with varying fluences of 5 × 10{sup 10}–1 × 10{sup 14} ions cm{sup −2}. The effects of irradiation on these samples have been investigated using, spectroscopic ellipsometry, atomic force microscopy and ultraviolet–visible–NIR spectroscopy techniques. Ellipsometry parameters, psi (Ψ) and delta (Δ) for the unirradiated sample and samples irradiated with different fluences were recorded. The data were fit to a three phase model to determine the refractive index and extinction coefficient. The refractive index and extinction coefficient for various fluences in ultraviolet, visible, and infrared, regimes were evaluated. Atomic force microscopy has been used to study these surface modifications. In order to have more statistical information about the surface, we have plotted the height structure histogram for all the samples. For unirradiated sample, we observed the Gaussian fitting. This result indicates the more ordered height structure symmetry. Whereas for the sample irradiated with the fluence of 1 × 10{sup 13}, 5 × 10{sup 13} and 1 × 10{sup 14} ions cm{sup −2}, we observed the scattered data. The width of the histogram for samples irradiated up to the fluence of 1 × 10{sup 13} ion cm{sup −2} was found to be almost same however it decreased at higher fluence. UV reflectance spectra of the sample irradiated with increasing fluences exhibit three peaks at 292, 500 and 617 nm represent the high energy GaSb; E{sub 1}, E{sub 1} + Δ and E{sub 2} band gaps in all irradiated samples.

  16. The effects of swift heavy ion irradiation on the structural properties of poly(lactide-co-glycolide)/clay nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet, E-mail: manpreet.kaur@abesit.in [ABES Institute of Technology,Ghaziabad, Uttar Pradesh (India); Singh, Surinder [Department of Physics, Guru Nanak Dev University, Amritsar (India); Mehta, Rajeev [Department of Chemical Engineering, Thapar University, Patiala (India)

    2016-05-23

    Radiation has been used as a processing technique to modify structural, chemical, physical and morphological properties of polymers and its nanocomposite and can thus be used as a method to control the rate of degradation. The swift heavy ions (SHI) irradiation effects on the structural properties of poly(lactide-co-glycolide) nanocomposites containing 5 wt% organo-montmorillonite (OMMT) clay by irradiating with 50 MeV Li{sup 3+} and 180 MeV Ag{sup 8+} ions has been studied at different fluences. The structural responses of PLGA nanocomposite under the influence of SHI were studied using Fourier transform infrared (FTIR) spectroscopy. The presence of clay and irradiation by swift heavy ions (SHI) brings out interesting changes in structural properties of nanocomposite.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    Protin, L.

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  1. Modification of phase transitions in swift heavy ion irradiated and MMA-grafted ferroelectric fluoro-polymers

    International Nuclear Information System (INIS)

    Petersohn, E.; Betz, N.; Le Moel, A.

    1994-01-01

    Ferroelectric polyvinylidene fluoride (β) and copolymers of vinylidene fluoride trifluoroethylene (P(VDF/TrFE)) films were irradiated with swift heavy ions and post irradiation grafted with methyl methacrylate (MMA). We have studied the influence of irradiation parameters such as the ion fluence, the type of ion and the electronic stopping power, on the melting and crystallization temperatures and the ferroelectric-paraelectric phase transitions, by differential scanning calorimetry (DSC) and dielectric measurements. The relation between the shift in the transition temperatures and the ion fluence is described by a single term equation. Ion track grafting with MMA affects the ferroelectric-paraelectric phase transitions in P(VDF/TrFE) and leads to a strong amorphization of the polymer films. The grafting in β PVDF occurs mainly on the surface of the samples and no change in the transition temperatures is observed. (authors). 12 refs., 6 figs., 2 tabs

  2. Enhanced AC conductivity and dielectric relaxation properties of polypyrrole nanoparticles irradiated with Ni12+ swift heavy ions

    International Nuclear Information System (INIS)

    Hazarika, J.; Kumar, A.

    2014-01-01

    In this paper, we report the 160 MeV Ni 12+ swift heavy ions (SHIs) irradiation effects on AC conductivity and dielectric relaxation properties of polypyrrole (PPy) nanoparticles in the frequency range of 42 Hz–5 MHz. Four ion fluences of 5 × 10 10 , 1 × 10 11 , 5 × 10 11 and 1 × 10 12 ions/cm 2 have been used for the irradiation purpose. Transport properties in the pristine and irradiated PPy nanoparticles have been investigated with permittivity and modulus formalisms to study the polarization effects and conductivity relaxation. With increasing ion fluence, the relaxation peak in imaginary modulus (M ″ ) plots shifts toward high frequency suggesting long range motion of the charge carriers. The AC conductivity studies suggest correlated barrier hopping as the dominant transport mechanism. The hopping distance (R ω ) of the charge carriers decreases with increasing the ion fluence. Binding energy (W m ) calculations depict that polarons are the dominant charge carriers

  3. The gaseous emission of polymers under swift heavy ion irradiation: effect of the electronic stopping power

    International Nuclear Information System (INIS)

    Picq, V.

    2000-07-01

    This thesis contributes to a better understanding of the damaging processes, which occur in polymers under swift heavy ion irradiation. The present study is exclusively devoted to the influence of the electronic stopping power, (dE/dx)e, on the molecular emission under irradiation. The irradiated polymers are polyethylene, polypropylene and poly-butene. The (dE/dx)e of the projectiles used varies from 3.5*10 -3 MeV.mg -1 .cm 2 (electron) to 39 MeV.mg -1 .cm 2 ( 58 Ni). We used two different experimental approaches in order to identify the nature of the emitted gases: mass spectrometry and infrared spectroscopy. The first technique is non selective, therefore, we could detect the emission of H 2 and heavy molecules; it also gives information on the diffusion kinetics of the molecules formed. The use of infrared spectroscopy for this kind of analysis is new and the technique was developed at the laboratory. It enables us to identify, without any ambiguity, molecules with up to three carbon atoms. The experimental spectra are analysed by using reference spectra of pure gases, measured in our laboratory. We have quantified precisely each identified gas, and we have followed the evolution of the radiochemical yields with increasing (dE/dx)e. The results, obtained at different (dE/dx)e, inform us on the different mechanisms of gas molecules formation, for example the side group departure and, at high (dE/dx)e, the fragmentation of the main chain which is due to multiple ionisation of the macromolecule. (author)

  4. Dewetting of nickel oxide-films on silicon under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Bolse, Thunu; Elsanousi, Ammar; Paulus, Hartmut; Bolse, Wolfgang

    2006-01-01

    Dewetting, occurring when a thin film on a non-wettable substrate turns into its liquid state, has gained strong interest during the last decade, since it results in nano-scale, large-area covering pattern formation. Recently we found that swift heavy ion (SHI) irradiation of thin NiO films on Si substrates at 80 K results in similar dewetting pattern, although in this case the coating has never reached its melting point. Careful inspection of the SEM images clearly revealed that the same nucleation mechanisms as observed for molten polymer films on Si (heterogeneous and homogeneous nucleation) were active. AFM shows that the circular holes formed in the early stages of the dewetting process exhibit a high and asymmetric rim-structure. RBS analysis was used to measure the coverage of the surface by the oxide films and revealed that the holes grow at constant velocity. This, and the shape of the rims, indicate that the material removed from the substrate surface piles up by plastic deformation, which points at a balance of the capillary driving forces and the hindered material dissipation

  5. Effects of swift heavy ion irradiation on the electrical characteristics of Au/n-GaAs Schottky diodes

    International Nuclear Information System (INIS)

    Sharma, A. Tarun; Shahnawaz; Kumar, Sandeep; Katharria, Yashpal S.; Kanjilal, Dinakar

    2007-01-01

    Metal-semiconductor diode of Au/n-GaAs is studied under the irradiation of swift heavy ion (SHI) beam (80 MeV 16 O 6+ ), using in situ current-voltage characterization technique. The diode parameters like ideality factor, barrier height, and leakage current are observed to vary with irradiation fluence. Significantly, the diode performance improves at a high fluence of 2 x 10 13 ions cm -2 with a large decrease of reverse leakage current in comparison to the original as deposited sample. The Schottky barrier height (SBH) also increases with fluence. At a high irradiation fluence of 5 x 10 13 ions cm -2 the SBH (0.62 ± 0.01 eV) is much larger than that of the as deposited sample (0.55 ± 0.01 eV). The diode parameters remain stable over a large range of irradiation up to fluence of 8 x 10 13 ions cm -2 . A prominent annealing effect of the swift ion beam owing to moderate electronic excitation and high ratio of electronic energy loss to the nuclear loss is found to be responsible for the improvement in diode characteristics

  6. Stability of Y-Ti-O nanoparticles in ODS alloys during heat treatment and high temperature swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Skuratov, V.A. [FLNR, JINR, Dubna (Russian Federation); National Research Nuclear University MEPhI, Moscow (Russian Federation); Dubna State University, Dubna (Russian Federation); Sohatsky, A.S.; Kornieieva, K. [FLNR, JINR, Dubna (Russian Federation); O' Connell, J.H.; Neethling, J.H. [CHRTEM, NMMU, Port Elizabeth (South Africa); Nikitina, A.A.; Ageev, V.S. [JSC VNIINM, Moscow (Russian Federation); Zdorovets, M. [Institute of Nuclear Physics, Astana (Kazakhstan); Ural Federal University, Yekaterinburg (Russian Federation); Volkov, A.D. [Nazarbayev University, Astana (Kazakhstan)

    2016-12-15

    Aim of this report is to compare the morphology of swift (167 and 220 MeV) Xe ion induced latent tracks in Y{sub 2}Ti{sub 2}O{sub 7} nanoparticles during post-irradiation heat treatment and after irradiation at different temperatures in pre-thinned TEM foils and TEM targets prepared from hundreds microns thick irradiated oxide dispersion strengthened (ODS) steel. No difference in track parameters was found in room temperature irradiated nanoparticles in pre-thinned and conventional samples. Microstructural data gathered from pre-thinned foils irradiated in the temperature range 350-650 C or annealed at similar temperatures demonstrate that amorphous latent tracks interact with the surrounding matrix, changing the track and nanoparticle morphology, while such effect is not observed in conventional ODS material treated at the same conditions. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Effect of swift heavy ion-irradiation on Cr/Fe/Ni multilayers

    International Nuclear Information System (INIS)

    Gupta, Ratnesh; Gupta, Ajay; Avasthi, D.K.; Principi, G.; Tosello, C.

    1999-01-01

    A multilayer film having overall composition Fe 50 Cr 25 Ni 25 , was irradiated successively by 80 MeV Si ions and Ag ions of 150 and 200 MeV energy. The energy deposited in the multilayer in the form of electronic excitations results in significant modification at the interfaces. The interfacial roughness increases in the system after the irradiations as revealed by X-ray reflectivity measurement. Moessbauer measurements provide evidence of intermixing after the irradiation by 200 MeV Ag ions. Comparison of heavy ion irradiated multilayer has been done with annealed and low energy ion irradiated samples. Results suggest that the phases formed at the interfaces of iron as a result of electronic energy loss are similar to those in the cases of thermal diffusion and keV energy ion beam irradiation

  8. Effect of swift heavy ion (SHI) irradiation on transparent conducting oxide electrodes for dye-sensitized solar cell applications

    International Nuclear Information System (INIS)

    Singh, Hemant Kr.; Avasthi, D.K.; Aggarwal, Shruti

    2015-01-01

    Highlights: •The objective is to study the effect of swift heavy ion (SHI) irradiation on photoanode of DSSC for better efficiency. •This work presents the effect of SHI irradiation on various Transparent conducting oxides (TCOs). •Effects are studied in terms of conductivity and transmittance of TCOs. •ITO-PET gives best results in comparison to ITO and FTO for DSSC application under SHI irradiation. -- Abstract: Transparent conducting oxides (TCOs) are used as electrodes in dye-sensitized solar cells (DSSCs) because of their properties such as high transmittance and low resistivity. In the present work, the effects of swift heavy ion (SHI) irradiation on various types of TCOs are presented. The objective of this study is to investigate the effect of SHI on TCOs. For the present study, three different types of TCOs are considered, namely, (a) FTO (fluorine-doped tin oxide, SnO 2 :F) on a Nippon glass substrate, (b) ITO (indium tin oxide, In 2 O 3 :Sn) coated on polyethylene terephthalate (PET) on a Corning glass substrate, and (c) ITO on a Corning glass substrate. These films are irradiated with 120 MeV Ag +9 ions at fluences ranging from 3.0 × 10 11 ions/cm 2 to 3.0 × 10 13 ions/cm 2 . The structural, morphological, optical and electrical properties are studied via X-ray diffraction (XRD), atomic force microscopy (AFM), UV–Vis absorption spectroscopy and four-probe resistivity measurements, respectively. The ITO-PET electrode is found to exhibit superior conductivity and transmittance properties in comparison with the others after irradiation and, therefore, to be the most suitable for solar cell applications

  9. Effect of swift heavy ion (SHI) irradiation on transparent conducting oxide electrodes for dye-sensitized solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Hemant Kr. [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi (India); Avasthi, D.K. [Inter University Accelerator Center, Post Box 10502, New Delhi (India); Aggarwal, Shruti, E-mail: shruti.al@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi (India)

    2015-06-15

    Highlights: •The objective is to study the effect of swift heavy ion (SHI) irradiation on photoanode of DSSC for better efficiency. •This work presents the effect of SHI irradiation on various Transparent conducting oxides (TCOs). •Effects are studied in terms of conductivity and transmittance of TCOs. •ITO-PET gives best results in comparison to ITO and FTO for DSSC application under SHI irradiation. -- Abstract: Transparent conducting oxides (TCOs) are used as electrodes in dye-sensitized solar cells (DSSCs) because of their properties such as high transmittance and low resistivity. In the present work, the effects of swift heavy ion (SHI) irradiation on various types of TCOs are presented. The objective of this study is to investigate the effect of SHI on TCOs. For the present study, three different types of TCOs are considered, namely, (a) FTO (fluorine-doped tin oxide, SnO{sub 2}:F) on a Nippon glass substrate, (b) ITO (indium tin oxide, In{sub 2}O{sub 3}:Sn) coated on polyethylene terephthalate (PET) on a Corning glass substrate, and (c) ITO on a Corning glass substrate. These films are irradiated with 120 MeV Ag{sup +9} ions at fluences ranging from 3.0 × 10{sup 11} ions/cm{sup 2} to 3.0 × 10{sup 13} ions/cm{sup 2}. The structural, morphological, optical and electrical properties are studied via X-ray diffraction (XRD), atomic force microscopy (AFM), UV–Vis absorption spectroscopy and four-probe resistivity measurements, respectively. The ITO-PET electrode is found to exhibit superior conductivity and transmittance properties in comparison with the others after irradiation and, therefore, to be the most suitable for solar cell applications.

  10. ion irradiation

    Indian Academy of Sciences (India)

    Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 m, spin coated on GaAs substrate were irradiated with 50 MeV Li ion (+3 charge state). Build-in ...

  11. Photorefractive response and optical damage of LiNbO3 optical waveguides produced by swift heavy ion irradiation

    Science.gov (United States)

    Villarroel, J.; Carrascosa, M.; García-Cabañes, A.; Caballero-Calero, O.; Crespillo, M.; Olivares, J.

    2009-06-01

    The photorefractive behaviour of a novel type of optical waveguides fabricated in LiNbO3 by swift heavy ion irradiation is investigated. First, the electro-optic coefficient r 33 of these guides that is crucial in the photorefractive effect is measured. Second, two complementary aspects of the photorefractive response are studied: (i) recording and light-induced and dark erasure of holographic gratings; (ii) optical beam degradation in single-beam configuration. The main photorefractive parameters, recording and erasing time constants, maximum refractive-index change and optical damage thresholds are determined.

  12. Lattice damage assessment and optical waveguide properties in LaAlO3 single crystal irradiated with swift Si ions

    Science.gov (United States)

    Liu, Y.; Crespillo, M. L.; Huang, Q.; Wang, T. J.; Liu, P.; Wang, X. L.

    2017-02-01

    As one of the representative ABO3 perovskite-structured oxides, lanthanum aluminate (LaAlO3) crystal has emerged as one of the most valuable functional-materials, and has attracted plenty of fundamental research and promising applications in recent years. Electronic, magnetic, optical and other properties of LaAlO3 strongly depend on its crystal structure, which could be strongly modified owing to the nuclear or electronic energy loss deposited in an ion irradiation environment and, therefore, significantly affecting the performance of LaAlO3-based devices. In this work, utilizing swift (tens of MeV) Si-ion irradiation, the damage behavior of LaAlO3 crystal induced by nuclear or electronic energy loss has been studied in detail utilizing complementary characterization techniques. Differing from other perovskite-structured crystals in which the electronic energy loss could lead to the formation of an amorphous region based on the thermal spike mechanism, in this case, intense electronic energy loss in LaAlO3 will not induce any obvious structural damage. The effects of ion irradiation on the mechanical properties, including hardness increase and elastic modulus decrease, have been confirmed. On the other hand, considering the potential applications of LaAlO3 in the field of integrated optoelectronics, the optical-waveguide properties of the irradiation region have been studied. The significant correspondence (symmetrical inversion) between the iWKB-reconstructed refractive-index profile and SRIM-simulated dpa profile further proves the effects (irradiation-damage production and refractive-index decrease) of nuclear energy loss during the swift-ion penetration process in LaAlO3 crystal. In the case of the rather-thick damage layer produced by swift-ion irradiation, obtaining a damage profile will be constrained owing to the analysis-depth limitation of the characterization techniques (RBS/channeling), and our analysis process (optical guided-mode measurement and

  13. Lattice damage assessment and optical waveguide properties in LaAlO3 single crystal irradiated with swift Si ions

    International Nuclear Information System (INIS)

    Liu, Y; Wang, T J; Liu, P; Wang, X L; Crespillo, M L; Huang, Q

    2017-01-01

    As one of the representative ABO 3 perovskite-structured oxides, lanthanum aluminate (LaAlO 3 ) crystal has emerged as one of the most valuable functional-materials, and has attracted plenty of fundamental research and promising applications in recent years. Electronic, magnetic, optical and other properties of LaAlO 3 strongly depend on its crystal structure, which could be strongly modified owing to the nuclear or electronic energy loss deposited in an ion irradiation environment and, therefore, significantly affecting the performance of LaAlO 3 -based devices. In this work, utilizing swift (tens of MeV) Si-ion irradiation, the damage behavior of LaAlO 3 crystal induced by nuclear or electronic energy loss has been studied in detail utilizing complementary characterization techniques. Differing from other perovskite-structured crystals in which the electronic energy loss could lead to the formation of an amorphous region based on the thermal spike mechanism, in this case, intense electronic energy loss in LaAlO 3 will not induce any obvious structural damage. The effects of ion irradiation on the mechanical properties, including hardness increase and elastic modulus decrease, have been confirmed. On the other hand, considering the potential applications of LaAlO 3 in the field of integrated optoelectronics, the optical-waveguide properties of the irradiation region have been studied. The significant correspondence (symmetrical inversion) between the iWKB-reconstructed refractive-index profile and SRIM-simulated dpa profile further proves the effects (irradiation-damage production and refractive-index decrease) of nuclear energy loss during the swift-ion penetration process in LaAlO 3 crystal. In the case of the rather-thick damage layer produced by swift-ion irradiation, obtaining a damage profile will be constrained owing to the analysis-depth limitation of the characterization techniques (RBS/channeling), and our analysis process (optical guided

  14. Optical waveguides in LiTaO{sub 3} crystals fabricated by swift C{sup 5+} ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guiyuan [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (Ministry of Education), Shandong University, Jinan 250100 (China); School of Science, Shandong Jianzhu University, Jinan 250101 (China); He, Ruiyun [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (Ministry of Education), Shandong University, Jinan 250100 (China); Akhmadaliev, Shavkat [Institute of Ion Beam and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01314 (Germany); Vázquez de Aldana, Javier R. [Laser Microprocessing Group, Universidad de Salamanca, Salamanca 37008 (Spain); Zhou, Shengqiang [Institute of Ion Beam and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01314 (Germany); Chen, Feng [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (Ministry of Education), Shandong University, Jinan 250100 (China)

    2014-04-01

    We report on the optical waveguides, in both planar and ridge configurations, fabricated in LiTaO{sub 3} crystal by using carbon (C{sup 5+}) ions irradiation at energy of 15 MeV. The planar waveguide was produced by direct irradiation of swift C{sup 5+} ions, whilst the ridge waveguides were manufactured by using femtosecond laser ablation of the planar layer. The reconstructed refractive index profile of the planar waveguide has showed a barrier-shaped distribution, and the near-field waveguide mode intensity distribution was in good agreement with the calculated modal profile. After thermal annealing at 260 °C in air, the propagation losses of both the planar and ridge waveguides were reduced to 10 dB/cm.

  15. Investigation of Au9+ swift heavy ion irradiation on CdS/CuInSe2 thin films

    International Nuclear Information System (INIS)

    Joshi, Rajesh A.; Taur, Vidya S.; Singh, Fouran; Sharma, Ramphal

    2013-01-01

    In the present manuscript we report about the preparation of CdS/CuInSe 2 heterojunction thin films by chemical ion exchange method and investigation of 120 MeV Au 9+ swift heavy ions (SHI) irradiation effect on its physicochemical as well as optoelectronic properties. These pristine (as grown) samples are irradiated with 120 MeV Au 9+ SHI of 5×10 11 and 5×10 12 ions/cm 2 fluencies and later on characterized for structural, compositional, morphological, optical and I–V characteristics. X-ray diffraction (XRD) pattern obtained from pristine and irradiated films shows considerable modifications in peak intensity as well as rising of some new peaks, corresponding to In 2 Se 3 , Cu 3 Se 2 and CuIn 2 Se 3 materials. Transmission electron microscope (TEM) images show decrease in grain size upon increase in irradiation ion fluencies, which is also supported from the observation of random and uneven distribution of nano-grains as confirmed through scanning electron microscope (SEM) images. Presence of Cd, Cu, In, S and Se in energy dispersive X-ray spectrum analysis (EDAX) confirms the expected and observed elemental composition in thin films, the absorbance peaks are related to band to band transitions and spin orbit splitting while energy band gap is observed to increase from 1.36 for pristine to 1.53 eV for SHI irradiated thin films and I–V characteristics under illumination to 100 mW/cm 2 light source shows enhancement in conversion efficiency from 0.26 to 1.59% upon irradiation. - Highlights: • Nanostructured CdS/CuInSe 2 can be grown by chemical ion exchange method. • Physicochemical and optoelectronic properties can be modified by 120 MeV Au 9+ SHI Irradiation. • Solar energy conversion efficiency improved from 0.26 to 1.59% in CdS/CuInSe 2 upon irradiation

  16. Recrystallization effects of swift heavy {sup 209}Bi ions irradiation on electrical degradation in 4H-SiC Schottky barrier diode

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhimei; Ma, Yao; Gong, Min [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Li, Yun [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Huang, Mingmin [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Gao, Bo [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Zhao, Xin, E-mail: zhaoxin1234@scu.edu.cn [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)

    2017-06-15

    In this paper, the phenomenon that the recrystallization effects of swift heavy {sup 209}Bi ions irradiation can partially recovery damage with more than 1 × 10{sup 10} ions/cm{sup 2} is investigated by the degradation of the electrical characteristics of 4H-SiC Schottky barrier diode (SBD) with swift heavy ion irradiation. Deep level transient spectroscopy (DLTS) and Current-Voltage (I-V) measurements clearly indicated that E{sub 0.62} defect induced by swift heavy ion irradiation, which was a recombination center, could result in the increase of reverse leakage current (I{sub R}) at fluence less than 1 × 10{sup 9} ions/cm{sup 2} and the recovery of I{sub R} at fluence more than 1 × 10{sup 10} ions/cm{sup 2} in 4H-SiC SBD. The variation tendency of I{sub R} is consisted with the change of E{sub 0.62} defect. Furthermore, it is reasonable explanation that the damage or defect formed at low fluence in SiC may be recovered by further swift heavy ion irradiation with high fluence, which is due to the melting with the ion tracks of the amorphous zones through a thermal spike and subsequent epitaxial recrystallization initiated from the neighboring crystalline regions.

  17. Enhanced AC conductivity and dielectric relaxation properties of polypyrrole nanoparticles irradiated with Ni{sup 12+} swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, J.; Kumar, A., E-mail: ask@tezu.ernet.in

    2014-08-15

    In this paper, we report the 160 MeV Ni{sup 12+} swift heavy ions (SHIs) irradiation effects on AC conductivity and dielectric relaxation properties of polypyrrole (PPy) nanoparticles in the frequency range of 42 Hz–5 MHz. Four ion fluences of 5 × 10{sup 10}, 1 × 10{sup 11}, 5 × 10{sup 11} and 1 × 10{sup 12} ions/cm{sup 2} have been used for the irradiation purpose. Transport properties in the pristine and irradiated PPy nanoparticles have been investigated with permittivity and modulus formalisms to study the polarization effects and conductivity relaxation. With increasing ion fluence, the relaxation peak in imaginary modulus (M{sup ″}) plots shifts toward high frequency suggesting long range motion of the charge carriers. The AC conductivity studies suggest correlated barrier hopping as the dominant transport mechanism. The hopping distance (R{sub ω}) of the charge carriers decreases with increasing the ion fluence. Binding energy (W{sub m}) calculations depict that polarons are the dominant charge carriers.

  18. Evaluation of cell behavior on modified polypropylene with swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Arbeitman, Claudia R.; Ibañez, Irene L.; García Bermúdez, Gerardo; Durán, Hebe; Grosso, Mariela F. del; Salguero, Noelia; Mazzei, Rubén

    2012-01-01

    Ion beam irradiation is a well known means to change the physico-chemical properties of polymers, and induced bio and citocompatibility in controlled conditions and in selected areas of surface. However, the enhancement of cell adhesion on a modified substrate does not mean that the surface is adequate for functional cells. The purpose of the present work is to study proliferation, changes in cytoskeleton and cell morphology on substrates as a function of irradiation parameters. We irradiated polypropylene with sulfur (S) ion-beam at energies of 110 MeV with fluences between 1 × 10 6 and 2 × 10 10 ions cm −2 . NIH 3T3 cells were cultured on each sample. Cell morphology was observed using phase contrast microscopy and cytoskeleton proteins with fluorescence microscopy. The analysis show different cellular responses as a functions of irradiation parameter, strongly suggests that different underlying substratum can result in distinct types of cytoskeleton reorganization.

  19. Microstructure and phase transformations in the ODS alloys irradiated by swift heavy ions

    International Nuclear Information System (INIS)

    Zlotski, S.V.; Anishchik, V.M; Skuratov, V.A.; O’Connell, J.; Neethling, J.H.

    2015-01-01

    Microstructure of KP4 ODS alloy irradiated with 700 MeV bismuth ions at 300 K has been studied using high resolution transmission electron microscopy. No latent tracks have been observed in Y 4 Al 2 O 9 particles in KP4 irradiated with Bi ions. Small oxides (~ 5 nm) in KP4 alloy remain crystalline at Bi ion fluence 1.5*10 13 cm -2 , while subsurface regions in large (~ 20 nm) particles faced to the beam entrance became amorphous. (authors)

  20. Effect of swift heavy ion (SHI) irradiation on transparent conducting oxide electrodes for dye-sensitized solar cell applications

    Science.gov (United States)

    Singh, Hemant Kr.; Avasthi, D. K.; Aggarwal, Shruti

    2015-06-01

    Transparent conducting oxides (TCOs) are used as electrodes in dye-sensitized solar cells (DSSCs) because of their properties such as high transmittance and low resistivity. In the present work, the effects of swift heavy ion (SHI) irradiation on various types of TCOs are presented. The objective of this study is to investigate the effect of SHI on TCOs. For the present study, three different types of TCOs are considered, namely, (a) FTO (fluorine-doped tin oxide, SnO2:F) on a Nippon glass substrate, (b) ITO (indium tin oxide, In2O3:Sn) coated on polyethylene terephthalate (PET) on a Corning glass substrate, and (c) ITO on a Corning glass substrate. These films are irradiated with 120 MeV Ag+9 ions at fluences ranging from 3.0 × 1011 ions/cm2 to 3.0 × 1013 ions/cm2. The structural, morphological, optical and electrical properties are studied via X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Vis absorption spectroscopy and four-probe resistivity measurements, respectively. The ITO-PET electrode is found to exhibit superior conductivity and transmittance properties in comparison with the others after irradiation and, therefore, to be the most suitable for solar cell applications.

  1. The sputtering of the deformed gold under irradiation with krypton swift heavy ions

    International Nuclear Information System (INIS)

    Didyk, A.Yu.; Semina, V.K.; Hofman, A.

    2002-01-01

    The results about sputtering yield of gold irradiated by 86 Kr ions with high inelastic energy losses up to a fluence of 10 14 ion/cm 2 are presented. It was shown that the sputtering (evaporation) yield strongly depends on the initial defect concentration in gold. The sputtering yield begins to grow very strongly with the increasing of damage created by heavy ion elastic and inelastic energy losses. The temperature on the surface in the area around krypton ion trajectory is much higher than the melting and evaporation temperatures for gold as follows from calculations with the various expressions and models

  2. FTIR studies of swift silicon and oxygen ion irradiated porous silicon

    International Nuclear Information System (INIS)

    Bhave, Tejashree M.; Hullavarad, S.S.; Bhoraskar, S.V.; Hegde, S.G.; Kanjilal, D.

    1999-01-01

    Fourier Transform Infrared Spectroscopy has been used to study the bond restructuring in silicon and oxygen irradiated porous silicon. Boron doped p-type (1 1 1) porous silicon was irradiated with 10 MeV silicon and a 14 MeV oxygen ions at different doses ranging between 10 12 and 10 14 ions cm -2 . The yield of PL in porous silicon irradiated samples was observed to increase considerably while in oxygen irradiated samples it was seen to improve only by a small extent for lower doses whereas it decreased for higher doses. The results were interpreted in view of the relative intensities of the absorption peaks associated with O-Si-H and Si-H stretch bonds

  3. Dewetting at the edge of a thin NiO-film on Si by swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Dautel, Knut; Ferhati, Redi; Bolse, Wolfgang

    2014-01-01

    We have investigated dewetting along a straight edge of a thin NiO-film on a Si-wafer induced by irradiation with 4.8 MeV/u Au-ions at room temperature. Both, the retreat of the edge as well as the opening and growth of circular holes in the film were monitored using our in-situ high resolution scanning electron microscope at the UNILAC accelerator at the Helmholtz Centre for Heavy Ion Research in Darmstadt. The “dewetting kinetics” (dependence of the retreated length and the hole radius on the ion fluence) are compared to previously published results on dewetting of poly-crystalline (Au) and glassy (polymer) films. In the present case the dewetting kinetics compare well with those observed for isothermal dewetting of the highly viscous polymer films, presumed that the role of time in thermally induced dewetting is taken over by the ion fluence in ion induced dewetting. Both, from the dewetting kinetics and the shape of the remaining NiO-traces in the dewetted area in front of the retreating edge, we conclude that the presently observed swift heavy ion induced dewetting occurs by interfacial slipping. It occurs in spatially and timely separated steps in the transiently molten single ion tracks, where the required reduction of the viscosity of NiO is achieved

  4. Dewetting at the edge of a thin NiO-film on Si by swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dautel, Knut; Ferhati, Redi; Bolse, Wolfgang, E-mail: w.bolse@ihfg.uni-stuttgart.de

    2014-01-01

    We have investigated dewetting along a straight edge of a thin NiO-film on a Si-wafer induced by irradiation with 4.8 MeV/u Au-ions at room temperature. Both, the retreat of the edge as well as the opening and growth of circular holes in the film were monitored using our in-situ high resolution scanning electron microscope at the UNILAC accelerator at the Helmholtz Centre for Heavy Ion Research in Darmstadt. The “dewetting kinetics” (dependence of the retreated length and the hole radius on the ion fluence) are compared to previously published results on dewetting of poly-crystalline (Au) and glassy (polymer) films. In the present case the dewetting kinetics compare well with those observed for isothermal dewetting of the highly viscous polymer films, presumed that the role of time in thermally induced dewetting is taken over by the ion fluence in ion induced dewetting. Both, from the dewetting kinetics and the shape of the remaining NiO-traces in the dewetted area in front of the retreating edge, we conclude that the presently observed swift heavy ion induced dewetting occurs by interfacial slipping. It occurs in spatially and timely separated steps in the transiently molten single ion tracks, where the required reduction of the viscosity of NiO is achieved.

  5. TEM study of damage recovery in SiC by swift Xe ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Skuratov, V.A., E-mail: skuratov@jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); O’Connell, J. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Sohatsky, A.S. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Neethling, J. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2014-05-01

    The microstructure of 4H–SiC samples subsequently irradiated with low energy He (10 keV), Ti (220 keV) and high energy (167 MeV) Xe ions has been studied using cross-sectional transmission electron microscopy. It was found that xenon ions with fluences above 10{sup 13} cm{sup −2} restore crystallinity in a heavily damaged partially amorphous zone. No, or negligible damage recovery is observed in fully amorphized layers of silicon carbide.

  6. TEM study of damage recovery in SiC by swift Xe ion irradiation

    International Nuclear Information System (INIS)

    Skuratov, V.A.; O’Connell, J.; Sohatsky, A.S.; Neethling, J.

    2014-01-01

    The microstructure of 4H–SiC samples subsequently irradiated with low energy He (10 keV), Ti (220 keV) and high energy (167 MeV) Xe ions has been studied using cross-sectional transmission electron microscopy. It was found that xenon ions with fluences above 10 13 cm −2 restore crystallinity in a heavily damaged partially amorphous zone. No, or negligible damage recovery is observed in fully amorphized layers of silicon carbide

  7. Shaping of Au nanoparticles embedded in various layered structures by swift heavy ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dawi, E.A., E-mail: elmuez.dawi@gmail.com [Ajman University of Science and Technology, Basic Science and Education, Physics Department, P.O. Box 346 (United Arab Emirates); Debye Institute for Nanomaterials, Nanophotonics Section, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands); ArnoldBik, W.M. [Eindhoven University of Technology, Irradiation Technology, 5600 GM Eindhoven (Netherlands); Ackermann, R.; Habraken, F.H.P.M. [Debye Institute for Nanomaterials, Nanophotonics Section, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands)

    2016-10-01

    We present a novel method to extend the ion-beam induced shaping of metallic nanoparticles in various layered structures. Monodisperse Au nanoparticles having mean diameter of 30 nm and their ion-shaping process is investigated for a limited number of experimental conditions. Au nanoparticles were embedded within a single plane in various layered structures of silicon nitride films (Si{sub 3}N{sub 4}), combinations of oxide-nitride films (SiO{sub 2}-Si{sub 3}N{sub 4}) and amorphous silicon films (a-Si) and have been sequentially irradiated at 300 K at normal incidence with 50 and 25 MeV Ag ions, respectively. Under irradiation with heavy Ag ions and with sequential increase of the irradiation fluence, the evolution of the Au peak derived from the Rutherford Backscattering Spectrometry show broadening in Au peak, which indicates that the Au becomes distributed over a larger depth region, indicative of the elongation of the nanoparticles. The latter is observed almost for every layer structure investigated except for Au nanoparticles embedded in pure a-Si matrix. The largest elongation rate at all fluences is found for the Au nanoparticles encapsulated in pure Si{sub 3}N{sub 4} films. For all irradiation energy applied, we again demonstrate the existence of both threshold and saturation fluences for the elongation effects mentioned.

  8. Microstructural response of InGaN to swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.M., E-mail: zhanglm@lzu.edu.cn [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Jiang, W. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Fadanelli, R.C. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre 91500 (Brazil); Ai, W.S.; Peng, J.X.; Wang, T.S. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Zhang, C.H. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-12-01

    A monocrystalline In{sub 0.18}Ga{sub 0.82}N film of ∼275 nm in thickness grown on a GaN/Al{sub 2}O{sub 3} substrate was irradiated with 290 MeV {sup 238}U{sup 32+} ions to a fluence of 1.2 × 10{sup 12} cm{sup −2} at room temperature. The irradiated sample was characterized using helium ion microscopy (HIM), Rutherford backscattering spectrometry under ion-channeling conditions (RBS/C), and high-resolution X-ray diffraction (HRXRD). The irradiation leads to formation of ion tracks throughout the thin In{sub 0.18}Ga{sub 0.82}N film and the 3.0 μm thick GaN buffer layer. The mean diameter of the tracks in In{sub 0.18}Ga{sub 0.82}N is ∼9 nm, as determined by HIM examination. Combination of the HIM and RBS/C data suggests that the In{sub 0.18}Ga{sub 0.82}N material in the track is likely to be highly disordered or fully amorphized. The irradiation induced lattice relaxation in In{sub 0.18}Ga{sub 0.82}N and a distribution of d-spacing of the (0 0 0 2) planes in GaN with lattice expansion are observed by HRXRD.

  9. On-line Raman spectroscopy of calcite and malachite during irradiation with swift heavy ions

    International Nuclear Information System (INIS)

    Dedera, Sebastian; Burchard, Michael; Glasmacher, Ulrich A.; Schöppner, Nicole; Trautmann, Christina; Severin, Daniel; Romanenko, Anton; Hubert, Christian

    2015-01-01

    A new on-line Raman System, which was installed at the M3-beamline at the UNILAC, GSI Helmholtzzentrum für Schwerionenforschung Darmstadt was used for first “in situ” spectroscopic measurements. Calcite and malachite samples were irradiated in steps between 1 × 10"9 and 1 × 10"1"2 ions/cm"2 with Au ions (calcite) and Xe ions (malachite) at an energy of 4.8 MeV/u. After irradiation, calcite revealed a new Raman band at 437 cm"−"1 and change of the full width at half maximum for the 1087 cm"−"1 Raman band. The Raman bands of malachite change significantly with increasing fluence. Up to a fluence of 7 × 10"1"0 ions/cm"2, all existing bands decrease in intensity. Between 8 × 10"1"0 and 1 × 10"1"1 ions/cm"2 a broad Cu_2O band between 110 and 220 cm"−"1 occurs, which superimposes the pre-existing Raman bands. Additionally, a new broad band between 1000 and 1750 cm"−"1 is formed, which is interpreted as a carbon coating. In contrast to the Cu_2O band, the carbon band vanished when further irradiating the sample. The installations as well as first in situ measurements at room temperature are presented.

  10. Radiation tolerance of nanostructured ZrN coatings against swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Janse van Vuuren, A.; Skuratov, V.A.; Uglov, V.V.; Neethling, J.H.; Zlotski, S.V.

    2013-01-01

    Nano-structured zirconium nitride layers – on Si substrates – of various thicknesses (0.1, 3, 10 and 20 μm) were irradiated with 167 MeV Xe, 250 MeV Kr and 695 MeV Bi ions to fluences in the range from 3 × 10 12 to 2.6 × 10 15 cm −2 for Xe, 1 × 10 13 to 7.06 × 10 13 cm −2 for Kr and 10 12 to 10 13 cm −2 for Bi. The purpose of these irradiation experiments is to simulate the effects of fission fragment bombardment on nanocrystalline ZrN. The irradiated layers where subsequently analysed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and nano-indentation hardness testing (NIH) techniques. XRD, TEM and NIH results indicate that ZrN has a very high tolerance to the effects of high energy irradiation

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Evaluation of cell behavior on modified polypropylene with swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Arbeitman, Claudia R., E-mail: arbeitman@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Ibanez, Irene L. [CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Garcia Bermudez, Gerardo [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Duran, Hebe [CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Gerencia de Desarrollo Tecnologico y Proyectos Especiales, TANDAR-CNEA (Argentina); Grosso, Mariela F. del [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Salguero, Noelia [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); Mazzei, Ruben [U.A. Tecnologicas y Agropecuarias, CNEA (Argentina)

    2012-02-15

    Ion beam irradiation is a well known means to change the physico-chemical properties of polymers, and induced bio and citocompatibility in controlled conditions and in selected areas of surface. However, the enhancement of cell adhesion on a modified substrate does not mean that the surface is adequate for functional cells. The purpose of the present work is to study proliferation, changes in cytoskeleton and cell morphology on substrates as a function of irradiation parameters. We irradiated polypropylene with sulfur (S) ion-beam at energies of 110 MeV with fluences between 1 Multiplication-Sign 10{sup 6} and 2 Multiplication-Sign 10{sup 10} ions cm{sup -2}. NIH 3T3 cells were cultured on each sample. Cell morphology was observed using phase contrast microscopy and cytoskeleton proteins with fluorescence microscopy. The analysis show different cellular responses as a functions of irradiation parameter, strongly suggests that different underlying substratum can result in distinct types of cytoskeleton reorganization.

  13. Swift heavy ion irradiation effects in {alpha} poly(vinylidene fluoride); Etude des effets induits par les ions lourds energetiques dans le poly(fluorure de vinylidene)

    Energy Technology Data Exchange (ETDEWEB)

    Le Bouedec, A

    1999-11-29

    The goal of this study is to characteristic and to localised defects created in {alpha} Poly (vinylidene fluoride) after swift heavy ion irradiations. PVDF films are irradiated with several Swift Heavy Ions (SHI), in the electronic stopping power (dE/dx){sub e}, in order to study the influence of irradiation parameters (absorbed dose, ion). These irradiated films are studied by different analysis techniques such as FTIR, ESR (X and Q band) spectroscopies and DSC. The crystalline level of PVDF is about 50% and we follow it destruction and amorphization as the absorbed dose increase by DSC and FTIR studies. The variation of the various FTIR bands allow us to observe the unsaturations induced by SHI radiations. Two sets of defects are observed: those which yield is sensitive to an increase of (dE/dx){sub e} and those that are not. A spatial distribution of the various defects within the talent track is provided and defects that are difficult to create are the closest of the ion path. The different kind of radicals created after irradiations are studied by ESR spectroscopy. Alkyl, peroxy and polyenyl radicals are detected after SHI radiations like after electron or {gamma} irradiations. Their yield of creation is independent of (dE/dx){sub e} and their localised in the crystalline zone or/and at the interfacial zone between crystalline and amorphous one. An other kind of radicals is created only after SHI radiations that are specific of the SHI-polymer interaction. We observe that these radicals are localised on a carbon cluster, in the core of the latent track for low doses and highly sensitive at the (dE/dx){sub e} of the ion. (author)

  14. Study on structural recovery of graphite irradiated with swift heavy ions at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pellemoine, F., E-mail: pellemoi@frib.msu.edu [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Avilov, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Bender, M. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Ewing, R.C. [Dept. of Geological Sciences, Stanford University, Stanford, CA 94305-2115 (United States); Fernandes, S. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Lang, M. [Dept. of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996-2300 (United States); Li, W.X. [Dept. of Geological Sciences, Stanford University, Stanford, CA 94305-2115 (United States); Mittig, W. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Schein, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Severin, D. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Tomut, M. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Laboratory of Magnetism and Superconductivity, National Institute for Materials Physics NIMP, Bucharest (Romania); Trautmann, C. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Dept. of Materials Science, Technische Universität Darmstadt, Darmstadt (Germany); and others

    2015-12-15

    Thin graphite foils bombarded with an intense high-energy (8.6 MeV/u) gold beam reaching fluences up to 1 × 10{sup 15} ions/cm{sup 2} lead to swelling and electrical resistivity changes. As shown earlier, these effects are diminished with increasing irradiation temperature. The work reported here extends the investigation of beam induced changes of these samples by structural analysis using synchrotron X-ray diffraction and transmission electron microscope. A nearly complete recovery from swelling at irradiation temperatures above about 1500 °C is identified.

  15. The near-infrared waveguide properties of an LGS crystal formed by swift Kr{sup 8+} ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yu-Fan; Liu, Peng; Liu, Tao; Zhang, Lian [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China); Sun, Jian-Rong; Wang, Zhi-Guang [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Xue-Lin, E-mail: xuelinwang@sdu.edu.cn [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China)

    2013-11-15

    In this work, we report on the optical properties in the near-infrared region of a LGS crystal planar waveguide formed by swift heavy ion irradiation. The planar optical waveguide in a LGS crystal was fabricated by 330 MeV Kr{sup 8+}-ion implantation at a fluence of 1 × 10{sup 12} cm{sup −2}. The initial beam had an energy of 2.1 GeV and was slowed down by passing it through a 259 μm thick Al foil. The guided mode was measured using a prism coupler at a wavelength of 1539 nm. The near-field intensity distribution of the mode was recorded by a CCD camera using the end-face coupling method. The FD-BPM was used to simulate the guided mode profile. The lattice damage induced by SHI irradiation in the LGS crystal was studied using micro-Raman spectroscopy. The Raman spectra are consistent with the stopping power distributions of the Kr{sup 8+} ions simulated by SRIM and with the micro-photograph of the waveguide taken by a microscope using polarized light.

  16. The near-infrared waveguide properties of an LGS crystal formed by swift Kr8+ ion irradiation

    Science.gov (United States)

    Zhou, Yu-Fan; Liu, Peng; Liu, Tao; Zhang, Lian; Sun, Jian-Rong; Wang, Zhi-Guang; Wang, Xue-Lin

    2013-11-01

    In this work, we report on the optical properties in the near-infrared region of a LGS crystal planar waveguide formed by swift heavy ion irradiation. The planar optical waveguide in a LGS crystal was fabricated by 330 MeV Kr8+-ion implantation at a fluence of 1 × 1012 cm-2. The initial beam had an energy of 2.1 GeV and was slowed down by passing it through a 259 μm thick Al foil. The guided mode was measured using a prism coupler at a wavelength of 1539 nm. The near-field intensity distribution of the mode was recorded by a CCD camera using the end-face coupling method. The FD-BPM was used to simulate the guided mode profile. The lattice damage induced by SHI irradiation in the LGS crystal was studied using micro-Raman spectroscopy. The Raman spectra are consistent with the stopping power distributions of the Kr8+ ions simulated by SRIM and with the micro-photograph of the waveguide taken by a microscope using polarized light.

  17. The near-infrared waveguide properties of an LGS crystal formed by swift Kr8+ ion irradiation

    International Nuclear Information System (INIS)

    Zhou, Yu-Fan; Liu, Peng; Liu, Tao; Zhang, Lian; Sun, Jian-Rong; Wang, Zhi-Guang; Wang, Xue-Lin

    2013-01-01

    In this work, we report on the optical properties in the near-infrared region of a LGS crystal planar waveguide formed by swift heavy ion irradiation. The planar optical waveguide in a LGS crystal was fabricated by 330 MeV Kr 8+ -ion implantation at a fluence of 1 × 10 12 cm −2 . The initial beam had an energy of 2.1 GeV and was slowed down by passing it through a 259 μm thick Al foil. The guided mode was measured using a prism coupler at a wavelength of 1539 nm. The near-field intensity distribution of the mode was recorded by a CCD camera using the end-face coupling method. The FD-BPM was used to simulate the guided mode profile. The lattice damage induced by SHI irradiation in the LGS crystal was studied using micro-Raman spectroscopy. The Raman spectra are consistent with the stopping power distributions of the Kr 8+ ions simulated by SRIM and with the micro-photograph of the waveguide taken by a microscope using polarized light

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  19. Thermal defect annealing of swift heavy ion irradiated ThO2

    Science.gov (United States)

    Palomares, Raul I.; Tracy, Cameron L.; Neuefeind, Joerg; Ewing, Rodney C.; Trautmann, Christina; Lang, Maik

    2017-08-01

    Isochronal annealing, neutron total scattering, and Raman spectroscopy were used to characterize the structural recovery of polycrystalline ThO2 irradiated with 2-GeV Au ions to a fluence of 1 × 1013 ions/cm2. Neutron diffraction patterns show that the Bragg signal-to-noise ratio increases and the unit cell parameter decreases as a function of isochronal annealing temperature, with the latter reaching its pre-irradiation value by 750 °C. Diffuse neutron scattering and Raman spectroscopy measurements indicate that an isochronal annealing event occurs between 275-425 °C. This feature is attributed to the annihilation of oxygen point defects and small oxygen defect clusters.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Radiation tolerance of nanostructured ZrN coatings against swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Vuuren, A., E-mail: arnojvv@gmail.com [Centre for HRTEM, Physics Department, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Skuratov, V.A. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna (Russian Federation); Uglov, V.V. [Department of Solid State Physics, Physics Faculty Belarusian State University, Minsk (Belarus); Neethling, J.H. [Centre for HRTEM, Physics Department, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Zlotski, S.V. [Department of Solid State Physics, Physics Faculty Belarusian State University, Minsk (Belarus)

    2013-11-15

    Nano-structured zirconium nitride layers – on Si substrates – of various thicknesses (0.1, 3, 10 and 20 μm) were irradiated with 167 MeV Xe, 250 MeV Kr and 695 MeV Bi ions to fluences in the range from 3 × 10{sup 12} to 2.6 × 10{sup 15} cm{sup −2} for Xe, 1 × 10{sup 13} to 7.06 × 10{sup 13} cm{sup −2} for Kr and 10{sup 12} to 10{sup 13} cm{sup −2} for Bi. The purpose of these irradiation experiments is to simulate the effects of fission fragment bombardment on nanocrystalline ZrN. The irradiated layers where subsequently analysed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and nano-indentation hardness testing (NIH) techniques. XRD, TEM and NIH results indicate that ZrN has a very high tolerance to the effects of high energy irradiation.

  2. Setup for in situ deep level transient spectroscopy of semiconductors during swift heavy ion irradiation.

    Science.gov (United States)

    Kumar, Sandeep; Kumar, Sugam; Katharria, Y S; Safvan, C P; Kanjilal, D

    2008-05-01

    A computerized system for in situ deep level characterization during irradiation in semiconductors has been set up and tested in the beam line for materials science studies of the 15 MV Pelletron accelerator at the Inter-University Accelerator Centre, New Delhi. This is a new facility for in situ irradiation-induced deep level studies, available in the beam line of an accelerator laboratory. It is based on the well-known deep level transient spectroscopy (DLTS) technique. High versatility for data manipulation is achieved through multifunction data acquisition card and LABVIEW. In situ DLTS studies of deep levels produced by impact of 100 MeV Si ions on Aun-Si(100) Schottky barrier diode are presented to illustrate performance of the automated DLTS facility in the beam line.

  3. Fabrication of planar waveguide in KNSBN crystal by swift heavy ion beam irradiation

    International Nuclear Information System (INIS)

    Guan, Jing; Wang, Lei; Qin, Xifeng

    2013-01-01

    We report on the fabrication of the planar waveguides in the KNSBN crystal by using 17 MeV C 5+ ions at a fluence of 2 × 10 14 ions/cm 2 . After implantation, near surface regions of the crystal, there has a positive extraordinary refractive index (n e ) change and the light inside the waveguides can propagate in a non-leaky manner. The two-dimensional modal profiles of the planar waveguides, measured by using the end-coupling arrangement, are in good agreement with the reconstructed modal distributions. The propagation loss for C 5+ irradiated waveguide is ∼0.8 dB/cm at 633 nm and ∼0.72 dB/cm at 1064 nm. The waveguide gives good confinement of waveguide modes, which exhibits acceptable guiding qualities for potential applications in integrated optics

  4. Fabrication of planar waveguide in KNSBN crystal by swift heavy ion beam irradiation

    Science.gov (United States)

    Guan, Jing; Wang, Lei; Qin, Xifeng

    2013-11-01

    We report on the fabrication of the planar waveguides in the KNSBN crystal by using 17 MeV C5+ ions at a fluence of 2 × 1014 ions/cm2. After implantation, near surface regions of the crystal, there has a positive extraordinary refractive index (ne) change and the light inside the waveguides can propagate in a non-leaky manner. The two-dimensional modal profiles of the planar waveguides, measured by using the end-coupling arrangement, are in good agreement with the reconstructed modal distributions. The propagation loss for C5+ irradiated waveguide is ∼0.8 dB/cm at 633 nm and ∼0.72 dB/cm at 1064 nm. The waveguide gives good confinement of waveguide modes, which exhibits acceptable guiding qualities for potential applications in integrated optics.

  5. Cumulative approaches to track formation under swift heavy ion (SHI) irradiation: Phenomenological correlation with formation energies of Frenkel pairs

    Energy Technology Data Exchange (ETDEWEB)

    Crespillo, M.L., E-mail: mcrespil@utk.edu [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Department of Materials Science & Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Agulló-López, F., E-mail: fal@uam.es [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Zucchiatti, A. [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain)

    2017-03-01

    Highlights: • Extensive survey formation energies Frenkel pairs and electronic stopping thresholds. • Correlation: track formation thresholds and the energies for Frenkel pair formation. • Formation energies Frenkel pairs discussed in relation to the cumulative mechanisms. • Amorphous track formation mechanisms: defect accumulation models versus melting. • Advantages cumulative models to deal with new hot topics: nuclear-electronic synergy. - Abstract: An extensive survey for the formation energies of Frenkel pairs, as representative candidates for radiation-induced point defects, is presented and discussed in relation to the cumulative mechanisms (CM) of track formation in dielectric materials under swift heavy ion (SHI) irradiation. These mechanisms rely on the generation and accumulation of point defects during irradiation followed by collapse of the lattice once a threshold defect concentration is reached. The physical basis of those approaches has been discussed by Fecht as a defect-assisted transition to an amorphous phase. Although a first quantitative analysis of the CM model was previously performed for LiNbO{sub 3} crystals, we have, here, adopted a broader phenomenological approach. It explores the correlation between track formation thresholds and the energies for Frenkel pair formation for a broad range of materials. It is concluded that the threshold stopping powers can be roughly scaled with the energies required to generate a critical Frenkel pair concentration in the order of a few percent of the total atomic content. Finally, a comparison with the predictions of the thermal spike model is discussed within the analytical Szenes approximation.

  6. Development of dual-beam system using an electrostatic accelerator for in-situ observation of swift heavy ion irradiation effects on materials

    Science.gov (United States)

    Matsuda, M.; Asozu, T.; Sataka, M.; Iwase, A.

    2013-11-01

    We have developed the dual beam system which accelerates two kinds of ion beams simultaneously especially for real-time ion beam analysis. We have also developed the alternating beam system which can efficiently change beam species in a short time in order to realize efficient ion beam analysis in a limited beam time. The acceleration of the dual beam is performed by the 20 UR Pelletron™ tandem accelerator in which an ECR ion source is mounted at the high voltage terminal [1,2]. The multi-charged ions of two or more elements can be simultaneously generated from the ECR ion source, so dual-beam irradiation is achieved by accelerating ions with the same charge to mass ratio (for example, 132Xe11+ and 12C+). It enables us to make a real-time beam analysis such as Rutherford Back Scattering (RBS) method, while a target is irradiated with swift heavy ions. For the quick change of the accelerating ion beam, the program of automatic setting of the optical parameter of the accelerator has been developed. The switchover time for changing the ion beam is about 5 min. These developments have been applied to the study on the ion beam mixing caused by high-density electronic excitation induced by swift heavy ions.

  7. Development of dual-beam system using an electrostatic accelerator for in-situ observation of swift heavy ion irradiation effects on materials

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, M., E-mail: matsuda.makoto@jaea.go.jp [Japan Atomic Energy Agency (JAEA-Tokai), Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Asozu, T.; Sataka, M. [Japan Atomic Energy Agency (JAEA-Tokai), Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Iwase, A. [Department of Materials Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan)

    2013-11-01

    We have developed the dual beam system which accelerates two kinds of ion beams simultaneously especially for real-time ion beam analysis. We have also developed the alternating beam system which can efficiently change beam species in a short time in order to realize efficient ion beam analysis in a limited beam time. The acceleration of the dual beam is performed by the 20 UR Pelletron™ tandem accelerator in which an ECR ion source is mounted at the high voltage terminal [1,2]. The multi-charged ions of two or more elements can be simultaneously generated from the ECR ion source, so dual-beam irradiation is achieved by accelerating ions with the same charge to mass ratio (for example, {sup 132}Xe{sup 11+} and {sup 12}C{sup +}). It enables us to make a real-time beam analysis such as Rutherford Back Scattering (RBS) method, while a target is irradiated with swift heavy ions. For the quick change of the accelerating ion beam, the program of automatic setting of the optical parameter of the accelerator has been developed. The switchover time for changing the ion beam is about 5 min. These developments have been applied to the study on the ion beam mixing caused by high-density electronic excitation induced by swift heavy ions.

  8. Effect of swift heavy ion irradiation on deep levels in Au /n-Si (100) Schottky diode studied by deep level transient spectroscopy

    Science.gov (United States)

    Kumar, Sandeep; Katharria, Y. S.; Kumar, Sugam; Kanjilal, D.

    2007-12-01

    In situ deep level transient spectroscopy has been applied to investigate the influence of 100MeV Si7+ ion irradiation on the deep levels present in Au/n-Si (100) Schottky structure in a wide fluence range from 5×109to1×1012ions cm-2. The swift heavy ion irradiation introduces a deep level at Ec-0.32eV. It is found that initially, trap level concentration of the energy level at Ec-0.40eV increases with irradiation up to a fluence value of 1×1010cm-2 while the deep level concentration decreases as irradiation fluence increases beyond the fluence value of 5×1010cm-2. These results are discussed, taking into account the role of energy transfer mechanism of high energy ions in material.

  9. Electron excitation relaxation in wide-gap single crystal insulators under swift heavy-ion irradiation

    International Nuclear Information System (INIS)

    Yavlinskii, Yu.N.

    2000-01-01

    A heavy, multicharged ion moving in a solid interacts with nuclei and electrons of the matter atoms. If the projectile velocity exceeds the typical orbital velocity of the target electrons, the main process is excitation of the electronic subsystem, i.e., excitation and ionization of bound electrons. Initially, relaxation of the electron excitations results from electronic processes alone, and energy transfer from electrons to lattice happens later. Since free charge carriers are absent in insulators before irradiation, the motion of the excited electrons is possible only together with holes. Due to inner pressure of the electron-hole plasma the expansion takes place. The velocity of the expansion is determined by the heat velocity of electron-hole pairs. As the excitation region expands, the density of the electron-hole pairs decreases, the average distance between pairs increases, and excitons are produced. The expansion can be terminated in the time t≅10 -13 s, when, due to the electron-phonon interaction, self-trapped holes (and excitons) are formed. The annihilation of the trapped excitons gives rise to Frenkel defects. The set of equations comprising the continuity equation, the Euler equation and energy conservation is considered. The analytic dependence on time of the electron temperature and the radius of the excitation region is derived. The observation of projectile traces in a target is discussed in the single projectile regime

  10. Elaboration by ion implantation of cobalt nano-particles in silica layers and modifications of their properties by electron and swift heavy ion irradiations

    International Nuclear Information System (INIS)

    D'Orleans, C.

    2003-07-01

    This work aims to investigate the capability of ion irradiations to elaborate magnetic nano-particles in silica layers, and to modify their properties. Co + ions have been implanted at 160 keV at fluences of 2.10 16 , 5.10 16 and 10 17 at/cm 2 , and at temperatures of 77, 295 and 873 K. The dependence of the particle size on the implantation fluence, and more significantly on the implantation temperature has been shown. TEM (transmission electronic microscopy) observations have shown a mean diameter varying from 1 nm for implantations at 2.10 16 Co + /cm 2 at 77 K, to 9.7 nm at 10 17 Co + /cm 2 at 873 K. For high temperature implantations, two regions of particles appear. Simulations based on a kinetic 3-dimensional lattice Monte Carlo method reproduce quantitatively the features observed for implantations. Thermal treatments induce the ripening of the particles. Electron irradiations at 873 K induce an important increase in mean particle sizes. Swift heavy ion irradiations also induce the ripening of the particles for low fluences, and an elongation of the particles in the incident beam direction for high fluences, resulting in a magnetic anisotropy. Mechanisms invoked in thermal spike model could also explain this anisotropic growth. (author)

  11. Opto-chemical response of Makrofol-KG to swift heavy ion irradiation

    Indian Academy of Sciences (India)

    transform infrared spectroscopy; atomic force spectroscopy. PACS Nos ... [8–10], electron beam [11], neutrons [12] and heavy ions [13]. The present .... Makrofol detector with proton and Xe ions, respectively and reported that at higher doses.

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

    Indian Academy of Sciences (India)

    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 ...

  13. Effect of swift heavy ion irradiation on structural, optical and electrical properties of Cd2SnO4 thin films

    International Nuclear Information System (INIS)

    Kumaravel, R.; Gokulakrishnan, V.; Ramamurthi, K.; Sulania, Indra; Kanjilal, D.; Asokan, K.; Avasthi, D.K.

    2010-01-01

    Transparent conducting cadmium stannate thin films were prepared by spray pyrolysis method on Corning substrate at a temperature of 525 o C. The prepared films are irradiated using 120 MeV swift Ag 9+ ions for the fluence in the range 1 x 10 12 to 1 x 10 13 ions cm -2 and the structural, optical and electrical properties were studied. The intensity of the film decreases with increasing ion fluence and amorphization takes place at higher fluence (1 x 10 13 ions cm -2 ). The transmittance of the films decreases with increasing ion fluence and also the band gap value decreases with increasing ion fluence. The resistivity of the film increased from 2.66 x 10 -3 Ω cm (pristine) to 5.57 x 10 -3 Ω cm for the film irradiated with 1 x 10 13 ions cm -2 . The mobility of the film decreased from 31 to 12 cm 2 /V s for the film irradiated with the fluence of 1 x 10 13 ions cm -2 .

  14. Swift Heavy Ions in Matter

    Science.gov (United States)

    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.

  15. Modification of photosensing property of CdS–Bi{sub 2}S{sub 3} bi-layer by thermal annealing and swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, Shaheed U.; Siddiqui, Farha Y. [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India); Singh, Fouran; Kulriya, Pawan K. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Phase, D.M. [UGC DAE Consortium for Scientific Research, Khandwa Road, Indore 452017 (India); Sharma, Ramphal, E-mail: ramphalsharma@yahoo.com [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India)

    2016-02-01

    The CdS–Bi{sub 2}S{sub 3} bi-layer thin films have been deposited on Indium Tin Oxide (ITO) glass substrates at room temperature by Chemical Bath Deposition Technique (CBD) and bi-layer thin films were annealed in air atmosphere for 1 h at 250 {sup °}C. The air annealed sample was irradiated using Au{sup 9+} ions at the fluence 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. Effects of Swift Heavy Ion (SHI) irradiation on CdS–Bi{sub 2}S{sub 3} bi-layer thin films were studied. The results are explained on the basis annealing and high electronic excitation, using X-ray diffraction (XRD), Selective Electron Area Diffraction (SEAD), Atomic Force Microscopy (AFM), Raman Spectroscopy, UV spectroscopy and I–V characteristics. The photosensing property after illumination of visible light over the samples is studied. These as-deposited, annealed and irradiated bi-layer thin films are used to sense visible light at room temperature. - Graphical abstract: Schematic illustration of CdS–Bi{sub 2}S{sub 3} bi-layer thin film (a) As-deposited (b) Annealed (c) irradiated sample respectively (d) Model of bi-layer photosensor device (e) Graph of illumination intensity verses photosensitivity. - Highlights: • CdS–Bi{sub 2}S{sub 3} bi-layer thin film prepared at room temperature. • Irradiated using Au{sup 9+} ions at the fluence of 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. • Study of modification induced by irradiations. • Study of Photosensitivity after annealing and irradiation.

  16. Swift heavy ion irradiated SnO_2 thin film sensor for efficient detection of SO_2 gas

    International Nuclear Information System (INIS)

    Tyagi, Punit; Sharma, Savita; Tomar, Monika; Singh, Fouran; Gupta, Vinay

    2016-01-01

    Highlights: • Response of Ni"7"+ ion irradiated (100 MeV) SnO_2 film have been performed. • Effect of irradiation on the structural and optical properties of SnO_2 film is studied. • A decrease in operating temperature and increased response is seen after irradiation. - Abstract: Gas sensing response studies of the Ni"7"+ ion irradiated (100 MeV) and non-irradiated SnO_2 thin film sensor prepared under same conditions have been performed towards SO_2 gas (500 ppm). The effect of irradiation on the structural, surface morphological, optical and gas sensing properties of SnO_2 thin film based sensor have been studied. A significant decrease in operating temperature (from 220 °C to 60 °C) and increased sensing response (from 1.3 to 5.0) is observed for the sample after irradiation. The enhanced sensing response obtained for the irradiated SnO_2 thin film based sensor is attributed to the desired modification in the surface morphology and material properties of SnO_2 thin film by Ni"7"+ ions.

  17. Investigations on the structural and optical properties of the swift heavy ion irradiated 6H-SiC

    International Nuclear Information System (INIS)

    Viswanathan, E.; Katharria, Y.S.; Selvakumar, S.; Arulchakkaravarthi, A.; Kanjilal, D.; Sivaji, K.

    2011-01-01

    Research highlights: → We have reported the structural and optical properties of SHI irradiated 6H-SiC. → The change in Raman modes evidences the disorder accumulation with respect to ion fluence. → The disorder also causes the modification in the optical properties. → The time resolved photoluminescence reflects multiple lifetimes due to the degenerate defects states. → The study also reveals the presence of partial amorphous region due to SHI irradiation. -- Abstract: Single crystal 6H-SiC wafers have been irradiated with 150 MeV Ag 12+ ions with fluences ranging from 1 x 10 11 to 1 x 10 13 ions/cm 2 at 300 K. The defect accumulation as a function of fluence was studied to determine changes in structural and optical properties. The variation in the fundamental Raman modes of the crystalline 6H-SiC due to irradiation has been correlated with the disorder accumulation. The creation of defect states due to irradiation in the bandgap affects the blue-green photoluminescence emission in the irradiated samples. The UV-Visible absorption studies support the existence of defect states in the bandgap which is observed by the shift in the absorption edge towards the lower energy side with increasing fluence. Time Correlated Single Photon Counting photoluminescence decay results suggest that the existing defect states are radiative, exhibiting three lifetimes when irradiated with a fluence 5 x 10 11 ions/cm 2 . The total number of lifetime components was reduced for a fluence 1 x 10 13 ions/cm 2 as the defect states produced increase the non-radiative defect centres. These results suggest that the accumulation of defects due to irradiation at fluences 5 x 10 11 and 1 x 10 13 ions/cm 2 are degenerate configurations which exhibit multiple lifetimes in photoluminescence studies. It is inferred that the optically active defect states influence the transition rate of charge carriers in this device material.

  18. Tailoring of refractive index profiles in LiNbO3 optical waveguides by low-fluence swift-ion irradiation

    International Nuclear Information System (INIS)

    Ruiz, T; Mendez, A; Carrascosa, M; Carnicero, J; GarcIa-Cabanes, A; Olivares, J; Agullo-Lopez, F; GarcIa-Navarro, A; GarcIa, G

    2007-01-01

    Proton-exchange LiNbO 3 planar optical waveguides have been irradiated with swift ions (Cl 30 MeV) at very low fluences in the range 5 x 10 10 -5 x 10 12 cm -2 . Large modifications in the refractive index profiles, and therefore in the optical performance, have been obtained due to the generation of amorphous nano-tracks by the individual ion impacts. Moreover, a fine tuning of the refractive index can be achieved by a suitable control of the fluence (δn/δφ ∼ 10 -14 cm 2 or δn ∼ 10 -5 for δφ = 10 9 cm -2 ). An effective medium approach has been used to account for those changes and determine the amorphous fraction of material. The results have been compared with information extracted from complementary RBS channelling experiments. From the calculated amorphous fractions a radius of ∼2 nm for the amorphous tracks have been estimated

  19. Micro-Raman studies of swift heavy ion irradiation induced structural and conformational changes in polyaniline nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Somik [Materials Research Laboratory, Department of Physics, Tezpur University, Tezpur 784028, Assam (India); Kumar, A., E-mail: ask@tezu.ernet.i [Materials Research Laboratory, Department of Physics, Tezpur University, Tezpur 784028, Assam (India)

    2010-09-15

    Polyaniline (PAni) nanofibers doped with camphor sulfonic acid have been irradiated with 90 MeV O{sup 7+} ions at different fluences (3 x 10{sup 10}-1 x 10{sup 12} ions/cm{sup 2}) using a 15UD Pelletron accelerator under ultra-high vacuum. XRD studies reveal a decrease in the domain length and an increase in the strain upon SHI irradiation. The increase in d-spacing corresponding to the (1 0 0) reflection of PAni nanofibers with increasing irradiation fluence has been attributed to the increase in the tilt angle of the chains with respect to the (a, b) basal plane of PAni. Decrease in the integral intensity upon SHI irradiation indicates amorphization of the material. Micro-Raman ({mu}R) studies confirm amorphization of the PAni nanofibers and also show that the PAni nanofibers get de-doped upon SHI irradiation. {mu}R spectroscopy also reveals a benzenoid to quinoid transition in the PAni chain upon SHI irradiation. TEM results show that the size of PAni nanofibers decreases with the increase in irradiation fluence, which has been attributed to the fragmentation of PAni nanofibers in the core of amorphized tracks caused by SHI irradiation.

  20. Ultrafast laser and swift heavy ion irradiation: Response of Gd 2 O 3 and ZrO 2 to intense electronic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Rittman, Dylan R.; Tracy, Cameron L.; Cusick, Alex B.; Abere, Michael J.; Torralva, Ben; Ewing, Rodney C.; Yalisove, Steven M.

    2015-04-27

    In order to investigate the response of materials to extreme conditions, there are several approaches to depositing extremely high concentrations of energy into very small volumes of material, including ultrafast laser and swift heavy ion (SHI) irradiation. In this study, crystalline-to-crystalline phase transformations in cubic Gd2O3 and monoclinic ZrO2 have been investigated using ultrafast laser irradiation. The phases produced by the extreme conditions of irradiation were characterized by grazing incidence x-ray diffraction (GIXRD) and Raman spectroscopy. Gd2O3 exhibited a cubic-to-monoclinic phase transformation, as evidenced by the appearance of the monoclinic (40$\\bar{2}$), (003), (310), and (112$\\bar{2}$) peaks in the GIXRD pattern and of four Ag and three Bg Raman modes. ZrO2 underwent a monoclinic-to-tetragonal phase transformation, as evidenced by the emergence of the tetragonal (101) peak in the GIXRD pattern and of Eg and A1g Raman modes. The new phases formed by ultrafast laser irradiation are high temperature polymorphs of the two materials. No evidence of amorphization was seen in the GIXRD data, though Raman spectroscopy indicated point defect accumulation. These results are identical to those produced by irradiation with SHIs, which also deposit energy in materials primarily through electronic excitation. The similarity in damage process and material response between ultrafast laser and SHI irradiation suggests a fundamental relationship between these two techniques.

  1. Investigations on the structural and optical properties of the swift heavy ion irradiated 6H-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, E. [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India); Katharria, Y.S. [Laboratoire de Physique des Interactions Ioniques et Moleculaires, Equipe Plasma-Surface, case 241, 13397 Marseille Cedex 20 (France); Selvakumar, S. [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India); Arulchakkaravarthi, A. [Sinmat Inc., 2153 SE Hawthorne Rd., Gainesville Fl-32641 (United States); Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, P.O. Box 10502, New Delhi 110067 (India); Sivaji, K., E-mail: sivaji.krishnan@yahoo.co [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India)

    2011-05-15

    Research highlights: {yields} We have reported the structural and optical properties of SHI irradiated 6H-SiC. {yields} The change in Raman modes evidences the disorder accumulation with respect to ion fluence. {yields} The disorder also causes the modification in the optical properties. {yields} The time resolved photoluminescence reflects multiple lifetimes due to the degenerate defects states. {yields} The study also reveals the presence of partial amorphous region due to SHI irradiation. -- Abstract: Single crystal 6H-SiC wafers have been irradiated with 150 MeV Ag{sup 12+} ions with fluences ranging from 1 x 10{sup 11} to 1 x 10{sup 13} ions/cm{sup 2} at 300 K. The defect accumulation as a function of fluence was studied to determine changes in structural and optical properties. The variation in the fundamental Raman modes of the crystalline 6H-SiC due to irradiation has been correlated with the disorder accumulation. The creation of defect states due to irradiation in the bandgap affects the blue-green photoluminescence emission in the irradiated samples. The UV-Visible absorption studies support the existence of defect states in the bandgap which is observed by the shift in the absorption edge towards the lower energy side with increasing fluence. Time Correlated Single Photon Counting photoluminescence decay results suggest that the existing defect states are radiative, exhibiting three lifetimes when irradiated with a fluence 5 x 10{sup 11} ions/cm{sup 2}. The total number of lifetime components was reduced for a fluence 1 x 10{sup 13} ions/cm{sup 2} as the defect states produced increase the non-radiative defect centres. These results suggest that the accumulation of defects due to irradiation at fluences 5 x 10{sup 11} and 1 x 10{sup 13} ions/cm{sup 2} are degenerate configurations which exhibit multiple lifetimes in photoluminescence studies. It is inferred that the optically active defect states influence the transition rate of charge carriers in this

  2. Enhancement of photo sensor properties of nanocrystalline ZnO thin film by swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, S. V.; Upadhye, D. S.; Bagul, S. B. [Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (India); Shaikh, S. U.; Birajadar, R. B.; Siddiqui, F. Y.; Huse, N. P. [Thin film and Nanotechnology Laboratory, Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (India); Sharma, R. B., E-mail: ramphalsharma@yahoo.com, E-mail: rps.phy@gmail.com [Thin film and Nanotechnology Laboratory, Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad-431004 (India)

    2015-06-24

    Nanocrystalline Zinc Oxide (ZnO) thin film prepared by Low cost Successive Ionic Layer Adsorption and Reaction (SILAR) method. This film was irradiated by 120 MeV Ni{sup 7+} ions with the fluence of 5x10{sup 12}ions/cm{sup 2}. The X-ray diffraction study was shows polycrystalline nature with wurtzite structure. The optical properties as absorbance were determined using UV-Spectrophotometer and band gap was also calculated. The Photo Sensor nature was calculated by I-V characteristics with different sources of light 40W, 60W and 100W.

  3. Monte Carlo simulation of damage and amorphization induced by swift-ion irradiation in LiNbO3

    International Nuclear Information System (INIS)

    Garcia, G.; Agullo-Lopez, F.; Olivares-Villegas, J.; Garcia-Navarro, A.

    2006-01-01

    This paper presents a Monte Carlo (MC) simulation tool which is applied to describe the ion beam induced damage generated by electronic excitation in LiNbO 3 . Based on a previously published thermal spike based analytical model, the MC technique allows for a more flexible and accurate treatment of the problem. A main advantage of this approach with respect to the analytical one is the possibility of studying the role of statistical fluctuations, relevant at low fluences. The paper recalls the main features of the physical model, describes the MC algorithm, and compares simulation results to experimental data (irradiations of LiNbO 3 using silicon ions at 5 and 7.5 MeV and oxygen ions at 5 MeV)

  4. Ultrafast laser and swift heavy ion irradiation: Response of Gd{sub 2}O{sub 3} and ZrO{sub 2} to intense electronic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Rittman, Dylan R. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Geological Sciences, Stanford University, Stanford, California 94305 (United States); Tracy, Cameron L.; Cusick, Alex B.; Abere, Michael J.; Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Ewing, Rodney C. [Department of Geological Sciences, Stanford University, Stanford, California 94305 (United States)

    2015-04-27

    In order to investigate the response of materials to extreme conditions, there are several approaches to depositing extremely high concentrations of energy into very small volumes of material, including ultrafast laser and swift heavy ion (SHI) irradiation. In this study, crystalline-to-crystalline phase transformations in cubic Gd{sub 2}O{sub 3} and monoclinic ZrO{sub 2} have been investigated using ultrafast laser irradiation. The phases produced by the extreme conditions of irradiation were characterized by grazing incidence x-ray diffraction (GIXRD) and Raman spectroscopy. Gd{sub 2}O{sub 3} exhibited a cubic-to-monoclinic phase transformation, as evidenced by the appearance of the monoclinic (402{sup ¯}), (003), (310), and (112{sup ¯}) peaks in the GIXRD pattern and of four A{sub g} and three B{sub g} Raman modes. ZrO{sub 2} underwent a monoclinic-to-tetragonal phase transformation, as evidenced by the emergence of the tetragonal (101) peak in the GIXRD pattern and of E{sub g} and A{sub 1g} Raman modes. The new phases formed by ultrafast laser irradiation are high temperature polymorphs of the two materials. No evidence of amorphization was seen in the GIXRD data, though Raman spectroscopy indicated point defect accumulation. These results are identical to those produced by irradiation with SHIs, which also deposit energy in materials primarily through electronic excitation. The similarity in damage process and material response between ultrafast laser and SHI irradiation suggests a fundamental relationship between these two techniques.

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

    International Nuclear Information System (INIS)

    Moisy, Florent

    2016-01-01

    Nitride semiconductors are attractive materials for optoelectronic applications. They can be subjected to heavy ions in a wide range of energy during their elaboration (improvement of their properties by ionic implantation) or during their potential use in extreme environments (outer space). This thesis focuses on the study of AlxGa1-xN alloys under heavy ion irradiation from GANIL. In GaN, the formation of Ga vacancies has been highlighted, these latter coming from elastic collisions between atoms in the material and the projectiles. On the other hand, it is possible to observe the formation of disordered ion tracks for projectiles with high electronic stopping power (Se). These tracks induce strong surface modifications, a closing of the optical bandgap, but also an extension strain along the direction parallel to the ion direction and biaxial stresses of some GPa. Concerning AlxGa1-xN alloys with x from 0.3 to 1, the points defects are more complex, and a synergy between electronic excitations and nuclear collisions is responsible of their formation. Nevertheless, the increase of the Al molar fraction (x), tends to improve the resistance to ion tracks formation in these materials. (author) [fr

  6. Formation of light-emitting nanostructures in layers of stoichiometric SiO{sub 2} irradiated with swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kachurin, G. A., E-mail: kachurin@isp.nsc.ru; Cherkova, S. G. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics (Russian Federation); Skuratov, V. A. [Joint Institute for Nuclear Research (Russian Federation); Marin, D. V.; Kesler, V. G.; Volodin, V. A. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics (Russian Federation)

    2011-10-15

    Thermally grown SiO{sub 2} layers have been irradiated with 700-MeV Bi ions with doses of (3-10) Multiplication-Sign 10{sup 12} cm{sup -2}. It is found that, even after a dose of 3 Multiplication-Sign 10{sup 12} cm{sup -2}, a photoluminescence band in the region of 600 nm appears. Its intensity levels off at a dose of {approx}5 Multiplication-Sign 10{sup 12} cm{sup -2}. The nature of the emission centers is studied by the methods of infrared transmission, Raman scattering, X-ray photoelectron spectroscopy, ellipsometry, and the reaction to passivating low-temperature anneals. It is established that irradiation brings about a decrease in the number of Si-O bonds with a relevant increase in the Si-Si bonds. It is assumed that the photoluminescence is caused by nanostructures containing an excess Si and/or having a deficit of O. The reaction of reduction of SiO{sub 2} proceeds in ion tracks due to high levels of ionization and heating within these tracks. The dose dependence is used to estimate the diameter of a track at 8-9 nm.

  7. Formation of light-emitting nanostructures in layers of stoichiometric SiO2 irradiated with swift heavy ions

    International Nuclear Information System (INIS)

    Kachurin, G. A.; Cherkova, S. G.; Skuratov, V. A.; Marin, D. V.; Kesler, V. G.; Volodin, V. A.

    2011-01-01

    Thermally grown SiO 2 layers have been irradiated with 700-MeV Bi ions with doses of (3–10) × 10 12 cm −2 . It is found that, even after a dose of 3 × 10 12 cm −2 , a photoluminescence band in the region of 600 nm appears. Its intensity levels off at a dose of ∼5 × 10 12 cm −2 . The nature of the emission centers is studied by the methods of infrared transmission, Raman scattering, X-ray photoelectron spectroscopy, ellipsometry, and the reaction to passivating low-temperature anneals. It is established that irradiation brings about a decrease in the number of Si-O bonds with a relevant increase in the Si-Si bonds. It is assumed that the photoluminescence is caused by nanostructures containing an excess Si and/or having a deficit of O. The reaction of reduction of SiO 2 proceeds in ion tracks due to high levels of ionization and heating within these tracks. The dose dependence is used to estimate the diameter of a track at 8–9 nm.

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

    International Nuclear Information System (INIS)

    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.

  9. Electron emission from solids induced by swift heavy ions

    International Nuclear Information System (INIS)

    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

  10. Response of Gd 2 Ti 2 O 7 and La 2 Ti 2 O 7 to swift-heavy ion irradiation and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sulgiye; Lang, Maik; Tracy, Cameron L.; Zhang, Jiaming; Zhang, Fuxiang; Trautmann, Christina; Rodriguez, Matias D.; Kluth, Patrick; Ewing, Rodney C.

    2015-07-01

    Swift heavy ion (2 GeV 181Ta) irradiation-induced amorphization and temperature-induced recrystallization of cubic pyrochlore Gd2Ti2O7 (Fd3¯m) are compared with the response of a compositionally-similar material with a monoclinic-layered perovskite-type structure, La2Ti2O7 (P21). The averaged electronic energy loss, dE/dx, was 37 keV/nm and 35 keV/nm in Gd2Ti2O7 and La2Ti2O7, respectively. Systematic analysis of the structural modifications was completed using transmission electron microscopy, synchrotron X-ray diffraction, Raman spectroscopy, and small-angle X-ray scattering. Increasing ion-induced amorphization with increasing ion fluence was evident in the X-ray diffraction patterns of both compositions by a reduction in the intensity of the diffraction maxima concurrent with the growth in intensity of a broad diffuse scattering halo. Transmission electron microscopy analysis showed complete amorphization within ion tracks (diameter: ~10 nm) for the perovskite-type material; whereas a concentric, core–shell morphology was evident in the ion tracks of the pyrochlore, with an outer shell of disordered yet still crystalline material with the fluorite structure surrounding an amorphous track core (diameter: ~9 nm). The radiation response of both titanate oxides with the same stoichiometry can be understood in terms of differences in their structures and compositions. While the radiation damage susceptibility of pyrochlore A2B2O7 materials decreases as a function of the cation radius ratio rA/rB, the current study correlates this behavior with the stability field of monoclinic structures, where rLa/rTi > rGd/rTi. Isochronal annealing experiments of the irradiated materials showed complete recrystallization of La2Ti2O7 at 775 °C and of Gd2Ti2O7 at 850 °C. The annealing behavior is discussed in terms of enhanced damage recovery in La2Ti2O7, compared to the pyrochlore compounds Gd2Ti2O7. The difference in the recrystallization behavior may be related to structural

  11. Study of the point defect creation and of the excitonic luminescence in alkali halides irradiated by swift heavy ions; Etude de la creation de defauts ponctuels et de la luminescence excitonique d`halogenures d`alcalins irradies par les ions lourds de grande vitesse

    Energy Technology Data Exchange (ETDEWEB)

    Protin, L

    1994-10-05

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

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

    International Nuclear Information System (INIS)

    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)

  13. Effects of swift heavy ion irradiation on La0.5Pr0.2Sr0.3MnO3 epitaxial thin films grown by pulsed laser deposition

    International Nuclear Information System (INIS)

    Markna, J.H.; Parmar, R.N.; Rana, D.S.; Ravi Kumar; Misra, P.; Kukreja, L.M.; Kuberkar, D.G.; Malik, S.K.

    2007-01-01

    We report the observation of room temperature insulator to metal transition and magnetoresistance characteristics of Swift Heavy Ions (SHIs) irradiated La 0.5 Pr 0.2 Sr 0.3 MnO 3 (LPSMO) epitaxial thin films grown on single crystal (1 0 0) SrTiO 3 substrates using Pulsed Laser Deposition. The epitaxial nature and crystallanity of the films was confirmed from the structural and magnetoresistance characteristics. Irradiation with the 200 MeV Ag 15+ ions at a fluence of about 5 x 10 11 ions/cm 2 showed suppression in the resistivity by ∼68% and 31% for the films with 50 nm and 100 nm thickness respectively. The possible reasons for this suppression could be either release of strain in the films in the dead layer at the interface of film-substrate or Swift Heavy Ions induced annealing which in turn affects the Mn-O-Mn bond angle thereby favoring the Zener double exchange. Field Coefficient of Resistance (FCR) values for both films, determined from R-H data and magnetoresistance data, showed a marginal enhancement after irradiation

  14. Modification of thin-layer systems by swift heavy ions

    International Nuclear Information System (INIS)

    Bolse, W.; Schattat, B.; Feyh, A.

    2003-01-01

    The electronic energy loss of swift heavy ions (MeV/amu) within a solid results in a highly excited cylindrical zone of some nm in diameter, within which all atoms may be in motion for some tens of ps (transient local melting). After cooling down, a defect-rich or even amorphous latent track is left in many cases, especially in insulating materials. The resulting property alterations (density, micro-structure, morphology, phase composition, etc.) have been investigated for many bulk materials, while only very few experiments have been carried out with thin-film systems. In the present paper, a summary will be given of our studies on the transport of matter in thin-film packages induced by irradiation with high-energy ions. These is, on the one hand, atomic mixing at the interfaces, which is especially pronounced in ceramic systems and which seems to occur by interdiffusion in the molten ion track. On the other hand, we have discovered a self-organisation phenomenon in swift-heavy-ion-irradiated NiO layers, which at low fluences first showed periodic cracking perpendicular to the projected beam direction. After application of high fluences, the NiO layer was reorganised in 100-nm-thick and 1-μm-high NiO lamellae of the same separation distance (1-3 μm) and orientation as found for the cracks. Both effects can be attributed to transient melting of the material surrounding the ion trajectory. (orig.)

  15. Low frequency alternating current conduction and dielectric relaxation in polypyrrole irradiated with 100 MeV swift heavy ions of silver (Ag{sup 8+})

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Amarjeet, E-mail: amarkaur@physics.du.ac.in [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Dhillon, Anju [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Avasthi, D.K. [Inter University Accelerator Center (IUAC), Aruna Asaf Ali Road, New Delhi 110067 (India)

    2013-07-15

    Polypyrrole (PPY) films were prepared by electrochemical polymerization technique. The fully undoped samples were irradiated with different radiation fluences ranging from 10{sup 10} to 10{sup 12} ions cm{sup −2} of 100 MeV silver (Ag{sup 8+}) ions. The temperature dependence of ac conductivity [σ{sub m}(ω)], dielectric constant (ε′) and dielectric loss (ε′′) of both irradiated as well as unirradiated samples have been investigated in 77–300 K. There exists typical Debye type dispersion. Giant increase in dielectric constant has been observed for irradiated samples which is attributed to polaronic defects produced during irradiation. - Graphical abstract: Display Omitted - Highlights: • Polypyrrole samples were prepared by electrochemical technique. • The fully undoped samples were irradiated with 100 MeV silver (Ag{sup 8+}) ions. • Giant increase in dielectric constant in irradiated samples is observed. • Dielectric behaviour is attributed to polaronic defects produced during irradiation.

  16. Low frequency alternating current conduction and dielectric relaxation in polypyrrole irradiated with 100 MeV swift heavy ions of silver (Ag8+)

    International Nuclear Information System (INIS)

    Kaur, Amarjeet; Dhillon, Anju; Avasthi, D.K.

    2013-01-01

    Polypyrrole (PPY) films were prepared by electrochemical polymerization technique. The fully undoped samples were irradiated with different radiation fluences ranging from 10 10 to 10 12 ions cm −2 of 100 MeV silver (Ag 8+ ) ions. The temperature dependence of ac conductivity [σ m (ω)], dielectric constant (ε′) and dielectric loss (ε′′) of both irradiated as well as unirradiated samples have been investigated in 77–300 K. There exists typical Debye type dispersion. Giant increase in dielectric constant has been observed for irradiated samples which is attributed to polaronic defects produced during irradiation. - Graphical abstract: Display Omitted - Highlights: • Polypyrrole samples were prepared by electrochemical technique. • The fully undoped samples were irradiated with 100 MeV silver (Ag 8+ ) ions. • Giant increase in dielectric constant in irradiated samples is observed. • Dielectric behaviour is attributed to polaronic defects produced during irradiation

  17. In situ defect annealing of swift heavy ion irradiated CeO2 and ThO2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

    Energy Technology Data Exchange (ETDEWEB)

    Palomares, Raul I.; Tracy, Cameron L.; Zhang, Fuxiang; Park, Changyong; Popov, Dmitry; Trautmann, Christina; Ewing, Rodney C.; Lang, Maik

    2015-04-16

    Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron X-ray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performingin situdefect annealing and thermal expansion studies of swift heavy ion irradiated CeO2and ThO2using synchrotron X-ray diffraction. The advantages of thein situHDAC technique over conventional annealing methods include rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature and apparatus stability at high temperatures. Isochronal annealing between 300 and 1100 K revealed two-stage and one-stage defect recovery processes for irradiated CeO2and ThO2, respectively, indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high-temperature defect recovery mechanisms of CeO2and ThO2.

  18. In-situ transport and microstructural evolution in GaN Schottky diodes and epilayers exposed to swift heavy ion irradiation

    Science.gov (United States)

    Kumar, Ashish; Singh, R.; Kumar, Parmod; Singh, Udai B.; Asokan, K.; Karaseov, Platon A.; Titov, Andrei I.; Kanjilal, D.

    2018-04-01

    A systematic investigation of radiation hardness of Schottky barrier diodes and GaN epitaxial layers is carried out by employing in-situ electrical resistivity and cross sectional transmission electron microscopy (XTEM) microstructure measurements. The change in the current transport mechanism of Au/n-GaN Schottky barrier diodes due to irradiation is reported. The role of irradiation temperature and ion type was also investigated. Creation of damage is studied in low and medium electron energy loss regimes by selecting different ions, Ag (200 MeV) and O (100 MeV) at various fluences at two irradiation temperatures (80 K and 300 K). GaN resistivity increases up to 6 orders of magnitude under heavy Ag ions. Light O ion irradiation has a much lower influence on sheet resistance. The presence of isolated defect clusters in irradiated GaN epilayers is evident in XTEM investigation which is explained on the basis of the thermal spike model.

  19. The gaseous emission of polymers under swift heavy ion irradiation: effect of the electronic stopping power; L'emission gazeuse des polymeres aliphatiques sous irradiation: effet du pouvoir d'arret electronique

    Energy Technology Data Exchange (ETDEWEB)

    Picq, V

    2000-07-01

    This thesis contributes to a better understanding of the damaging processes, which occur in polymers under swift heavy ion irradiation. The present study is exclusively devoted to the influence of the electronic stopping power, (dE/dx)e, on the molecular emission under irradiation. The irradiated polymers are polyethylene, polypropylene and poly-butene. The (dE/dx)e of the projectiles used varies from 3.5*10{sup -3} MeV.mg{sup -1}.cm{sup 2} (electron) to 39 MeV.mg{sup -1}.cm{sup 2} ({sup 58}Ni). We used two different experimental approaches in order to identify the nature of the emitted gases: mass spectrometry and infrared spectroscopy. The first technique is non selective, therefore, we could detect the emission of H{sub 2} and heavy molecules; it also gives information on the diffusion kinetics of the molecules formed. The use of infrared spectroscopy for this kind of analysis is new and the technique was developed at the laboratory. It enables us to identify, without any ambiguity, molecules with up to three carbon atoms. The experimental spectra are analysed by using reference spectra of pure gases, measured in our laboratory. We have quantified precisely each identified gas, and we have followed the evolution of the radiochemical yields with increasing (dE/dx)e. The results, obtained at different (dE/dx)e, inform us on the different mechanisms of gas molecules formation, for example the side group departure and, at high (dE/dx)e, the fragmentation of the main chain which is due to multiple ionisation of the macromolecule. (author)

  20. Swift heavy ion irradiated SnO{sub 2} thin film sensor for efficient detection of SO{sub 2} gas

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Punit; Sharma, Savita [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Tomar, Monika [Department of Physics, Miranda House, University of Delhi, Delhi 110007 (India); Singh, Fouran [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110067 (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2016-07-15

    Highlights: • Response of Ni{sup 7+} ion irradiated (100 MeV) SnO{sub 2} film have been performed. • Effect of irradiation on the structural and optical properties of SnO{sub 2} film is studied. • A decrease in operating temperature and increased response is seen after irradiation. - Abstract: Gas sensing response studies of the Ni{sup 7+} ion irradiated (100 MeV) and non-irradiated SnO{sub 2} thin film sensor prepared under same conditions have been performed towards SO{sub 2} gas (500 ppm). The effect of irradiation on the structural, surface morphological, optical and gas sensing properties of SnO{sub 2} thin film based sensor have been studied. A significant decrease in operating temperature (from 220 °C to 60 °C) and increased sensing response (from 1.3 to 5.0) is observed for the sample after irradiation. The enhanced sensing response obtained for the irradiated SnO{sub 2} thin film based sensor is attributed to the desired modification in the surface morphology and material properties of SnO{sub 2} thin film by Ni{sup 7+} ions.

  1. Creation of nanoscale objects by swift heavy ion track manipulations

    International Nuclear Information System (INIS)

    Fink, D.; Petrov, A.; Stolterfoht, N.

    2003-01-01

    In this work we give an overview of the possibilities to create new objects with nanoscale dimensions with ion tracks, for future applications. This can be realized in two ways: by manipulation of latent swift heavy ion (SHI) tracks, or by embedding specific structures within etched SHI tracks. In the first case one can make use of irradiation effects such as phase transitions and chemical or structural changes along the tracks. In the latter case, one can fill etched SHI tracks with metals, semiconductors, insulating and conducting polymers, fullerite, or colloides. Wires and tubules with outer diameters, between about 50 nm and 5 μm and lengths of up to about 100 μm can be obtained. The most important production techniques are galvanic and chemical depositions. Ion Transmission Spectrometry has turned out to be an especially useful tool for the characterisation of the produced objects. Present studies aim at the construction of condensers, magnets, diodes, and sensors in etched tracks. An obstacle for the practical realization of smallest-size polymeric ion track devices is the statistical distribution of the ion tracks on the target areas, which yields some pixels without any track, and other pixels even with overlapping tracks on a given sample. In a first test experiment we demonstrate that one can, in principle, overcome that problem by taking self-ordered porous foils as masks for subsequent high-fluence SHI irradiation. (author)

  2. Swift-heavy ion track electronics (SITE)

    International Nuclear Information System (INIS)

    Fink, D.; Chadderton, L.T.; Hoppe, K.; Fahrner, W.R.; Chandra, A.; Kiv, A.

    2007-01-01

    An overview about the state-of-art of the development of a new type of nanoelectronics based on swift-heavy ions is given. Polymeric as well as silicon-based substrates have been used, and both latent and etched ion tracks play a role. Nowadays the interest has shifted from simple scaling-down of capacitors, magnets, transformers, diodes, transistors, etc. towards new types of ion track-based structures hitherto unknown in electronics. These novel structures, denoted by the acronyms 'TEAMS' (tunable electrically anisotropic material on semiconductor) and 'TEMPOS' (tunable electronic material with pores in oxide on semiconductor), may exhibit properties of tunable resistors, capacitors, diodes, sensors and transistors. Their general current/voltage characteristics are outlined. As these structures are often influenced by ambient physical or chemical parameters they also act as sensors. A peculiarity of these structures is the occurrence of negative differential resistances (NDRs) which makes them feasible for applications in tunable flip-flops, amplifiers and oscillators

  3. Swift-heavy ion track electronics (SITE)

    Energy Technology Data Exchange (ETDEWEB)

    Fink, D. [Hahn-Meitner-Institute Berlin, Glienicker Str. 100, D-14109 Berlin (Germany)]. E-mail: fink@hmi.de; Chadderton, L.T. [Institute of Advanced Studies, ANU Canberra, G.P.O. Box 4, ACT (Australia); Hoppe, K. [South Westfalia University of Applied Sciences, Hagen (Germany); Fahrner, W.R. [Chair of Electronic Devices, Inst. of Electrotechnique, Fernuniversitaet, Hagen (Germany); Chandra, A. [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Kiv, A. [Ben Gurion University of the Negev, Israel, P.O. Box 653, Beer-Sheva, 84105 (Israel)

    2007-08-15

    An overview about the state-of-art of the development of a new type of nanoelectronics based on swift-heavy ions is given. Polymeric as well as silicon-based substrates have been used, and both latent and etched ion tracks play a role. Nowadays the interest has shifted from simple scaling-down of capacitors, magnets, transformers, diodes, transistors, etc. towards new types of ion track-based structures hitherto unknown in electronics. These novel structures, denoted by the acronyms 'TEAMS' (tunable electrically anisotropic material on semiconductor) and 'TEMPOS' (tunable electronic material with pores in oxide on semiconductor), may exhibit properties of tunable resistors, capacitors, diodes, sensors and transistors. Their general current/voltage characteristics are outlined. As these structures are often influenced by ambient physical or chemical parameters they also act as sensors. A peculiarity of these structures is the occurrence of negative differential resistances (NDRs) which makes them feasible for applications in tunable flip-flops, amplifiers and oscillators.

  4. Modifications of gallium phosphide single crystals using slow highly charged ions and swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    El-Said, A.S., E-mail: elsaid@kfupm.edu.sa [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Wilhelm, R.A.; Heller, R.; Akhmadaliev, Sh.; Schumann, E. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Sorokin, M. [National Research Centre ’Kurchatov Institute’, Kurchatov Square 1, 123182 Moscow (Russian Federation); Facsko, S. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2016-09-01

    GaP single crystals were irradiated with slow highly charged ions (HCI) using 114 keV {sup 129}Xe{sup (33–40)+} and with various swift heavy ions (SHI) of 30 MeV I{sup 9+} and 374 MeV–2.2 GeV {sup 197}Au{sup 25+}. The irradiated surfaces were investigated by scanning force microscopy (SFM). The irradiations with SHI lead to nanohillocks protruding from the GaP surfaces, whereas no changes of the surface topography were observed after the irradiation with HCI. This result indicates that a potential energy above 38.5 keV is required for surface nanostructuring of GaP. In addition, strong coloration of the GaP crystals was observed after irradiation with SHI. The effect was stronger for higher energies. This was confirmed by measuring an increased extinction coefficient in the visible light region.

  5. Elaboration by ion implantation of cobalt nano-particles in silica layers and modifications of their properties by electron and swift heavy ion irradiations; Elaboration par implantation ionique de nanoparticules de cobalt dans la silice et modifications de leurs proprietes sous irradiation d'electrons et d'ions de haute energie

    Energy Technology Data Exchange (ETDEWEB)

    D' Orleans, C

    2003-07-15

    This work aims to investigate the capability of ion irradiations to elaborate magnetic nano-particles in silica layers, and to modify their properties. Co{sup +} ions have been implanted at 160 keV at fluences of 2.10{sup 16}, 5.10{sup 16} and 10{sup 17} at/cm{sup 2}, and at temperatures of 77, 295 and 873 K. The dependence of the particle size on the implantation fluence, and more significantly on the implantation temperature has been shown. TEM (transmission electronic microscopy) observations have shown a mean diameter varying from 1 nm for implantations at 2.10{sup 16} Co{sup +}/cm{sup 2} at 77 K, to 9.7 nm at 10{sup 17} Co{sup +}/cm{sup 2} at 873 K. For high temperature implantations, two regions of particles appear. Simulations based on a kinetic 3-dimensional lattice Monte Carlo method reproduce quantitatively the features observed for implantations. Thermal treatments induce the ripening of the particles. Electron irradiations at 873 K induce an important increase in mean particle sizes. Swift heavy ion irradiations also induce the ripening of the particles for low fluences, and an elongation of the particles in the incident beam direction for high fluences, resulting in a magnetic anisotropy. Mechanisms invoked in thermal spike model could also explain this anisotropic growth. (author)

  6. Elaboration by ion implantation of cobalt nano-particles in silica layers and modifications of their properties by electron and swift heavy ion irradiations; Elaboration par implantation ionique de nanoparticules de cobalt dans la silice et modifications de leurs proprietes sous irradiation d'electrons et d'ions de haute energie

    Energy Technology Data Exchange (ETDEWEB)

    D' Orleans, C

    2003-07-15

    This work aims to investigate the capability of ion irradiations to elaborate magnetic nano-particles in silica layers, and to modify their properties. Co{sup +} ions have been implanted at 160 keV at fluences of 2.10{sup 16}, 5.10{sup 16} and 10{sup 17} at/cm{sup 2}, and at temperatures of 77, 295 and 873 K. The dependence of the particle size on the implantation fluence, and more significantly on the implantation temperature has been shown. TEM (transmission electronic microscopy) observations have shown a mean diameter varying from 1 nm for implantations at 2.10{sup 16} Co{sup +}/cm{sup 2} at 77 K, to 9.7 nm at 10{sup 17} Co{sup +}/cm{sup 2} at 873 K. For high temperature implantations, two regions of particles appear. Simulations based on a kinetic 3-dimensional lattice Monte Carlo method reproduce quantitatively the features observed for implantations. Thermal treatments induce the ripening of the particles. Electron irradiations at 873 K induce an important increase in mean particle sizes. Swift heavy ion irradiations also induce the ripening of the particles for low fluences, and an elongation of the particles in the incident beam direction for high fluences, resulting in a magnetic anisotropy. Mechanisms invoked in thermal spike model could also explain this anisotropic growth. (author)

  7. Structural, surface potential and optical studies of AlGaN based double heterostructures irradiated by 120 MeV Si{sup 9+} swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Arivazhagan, P., E-mail: arivazhaganau2008@gmail.com [Crystal Growth Centre, Anna University, Chennai, 600 025 (India); Ramesh, R.; Balaji, M. [Crystal Growth Centre, Anna University, Chennai, 600 025 (India); Asokan, K. [Inter-University Accelerator Centre (IUAC), New Delhi (India); Baskar, K. [Crystal Growth Centre, Anna University, Chennai, 600 025 (India)

    2016-09-15

    The Al{sub 0.33}Ga{sub 0.77}N/Al{sub 0.14}Ga{sub 0.86}N based double heterostructure was irradiated using Si{sup 9+} ion at room temperature (RT) and liquid nitrogen temperature (LNT) with four dissimilar ion fluence. The effect of Si{sup 9+} ion irradiation in dislocation densities and in-plane strain of GaN layer were discussed. The in-plane strain values of Al{sub x}Ga{sub 1-x}N layers were calculated from asymmetric reciprocal space mapping (RSM). The surface modification and the variation in phase shift on Al{sub 0.33}Ga{sub 0.77}N surfaces due to the irradiation were measured by Electrostatic Force Microscopy (EFM). The capacitance of the tip-sample system was determined from EFM. The band edge emissions of heterostructures were measured by the room temperature phototluminescence (PL) and the shift in the Al{sub 0.14}Ga{sub 0.86}N active layer emission peaks towards the low energy side at low fluence ion irradiation has been noted. - Highlights: • Effects of Si{sup 9+} ion irradiation on AlGaN double heterostructures were investigated. • Dislocation densities of GaN reduced at liquid nitrogen temperature irradiation. • Variation in phase shift on Al{sub 0.33}Ga{sub 0.77}N surfaces was measured by EFM. • Capacitance per unit area values of AFM tip-sample surface system were calculated. • Si{sup 9+} irradiations play an important role to tune the energy gap in Al{sub 0.14}Ga{sub 0.86}N.

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

    International Nuclear Information System (INIS)

    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

  9. In situ and postradiation analysis of mechanical stress in Al2O3:Cr induced by swift heavy-ion irradiation

    International Nuclear Information System (INIS)

    Skuratov, V.A.; Bujnarowski, G.; Kovalev, Yu.S.; O'Connell, J.; Havanscak, K.

    2010-01-01

    Optical spectroscopy and TEM techniques have been applied to study the radiation damage and correlated mechanical stresses in Al 2 O 3 and Al 2 O 3 :Cr single crystals induced by (1-3) MeV/amu Kr, Xe and Bi ion irradiation. Mechanical stresses were evaluated in situ using a piezospectroscopic effect through the shift of the respective lines in ionoluminescence spectra. It was found that dose dependence of the stress level for Xe and Bi ions, when ionization energy loss exceeds the threshold of damage formation via electronic excitations, exhibits several alternate stages showing the build-up and relaxation of stresses. The beginning of relaxation stages is observed at fluences associated with beginning of individual ion track regions overlapping. The residual stress profiles through the ion irradiated layers were deduced from depth-resolved photostimulated spectra using laser confocal scanning microscopy set-up. It was determined that stresses are compressive in basal plane and tensile in perpendicular direction in all samples irradiated with high energy ions.

  10. In situ and postradiation analysis of mechanical stress in Al{sub 2}O{sub 3}:Cr induced by swift heavy-ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Skuratov, V.A., E-mail: skuratov@jinr.r [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Bujnarowski, G. [Institute of Physics, Opole University, 45-052 Opole (Poland); Kovalev, Yu.S. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); O' Connell, J. [Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Havanscak, K. [Eoetvoes University, Pazmany P. setany 1/A, H-1117 Budapest (Hungary)

    2010-10-01

    Optical spectroscopy and TEM techniques have been applied to study the radiation damage and correlated mechanical stresses in Al{sub 2}O{sub 3} and Al{sub 2}O{sub 3}:Cr single crystals induced by (1-3) MeV/amu Kr, Xe and Bi ion irradiation. Mechanical stresses were evaluated in situ using a piezospectroscopic effect through the shift of the respective lines in ionoluminescence spectra. It was found that dose dependence of the stress level for Xe and Bi ions, when ionization energy loss exceeds the threshold of damage formation via electronic excitations, exhibits several alternate stages showing the build-up and relaxation of stresses. The beginning of relaxation stages is observed at fluences associated with beginning of individual ion track regions overlapping. The residual stress profiles through the ion irradiated layers were deduced from depth-resolved photostimulated spectra using laser confocal scanning microscopy set-up. It was determined that stresses are compressive in basal plane and tensile in perpendicular direction in all samples irradiated with high energy ions.

  11. Role of temperature in the radiation stability of yttria stabilized zirconia under swift heavy ion irradiation: A study from the perspective of nuclear reactor applications

    Science.gov (United States)

    Kalita, Parswajit; Ghosh, Santanu; Sattonnay, Gaël; Singh, Udai B.; Grover, Vinita; Shukla, Rakesh; Amirthapandian, S.; Meena, Ramcharan; Tyagi, A. K.; Avasthi, Devesh K.

    2017-07-01

    The search for materials that can withstand the harsh radiation environments of the nuclear industry has become an urgent challenge in the face of ever-increasing demands for nuclear energy. To this end, polycrystalline yttria stabilized zirconia (YSZ) pellets were irradiated with 80 MeV Ag6+ ions to investigate their radiation tolerance against fission fragments. To better simulate a nuclear reactor environment, the irradiations were carried out at the typical nuclear reactor temperature (850 °C). For comparison, irradiations were also performed at room temperature. Grazing incidence X-ray diffraction and Raman spectroscopy measurements reveal degradation in crystallinity for the room temperature irradiated samples. No bulk structural amorphization was however observed, whereas defect clusters were formed as indicated by transmission electron microscopy and supported by thermal spike simulation results. A significant reduction of the irradiation induced defects/damage, i.e., improvement in the radiation tolerance, was seen under irradiation at 850 °C. This is attributed to the fact that the rapid thermal quenching of the localized hot molten zones (arising from spike in the lattice temperature upon irradiation) is confined to 850 °C (i.e., attributed to the resistance inflicted on the rapid thermal quenching of the localized hot molten zones by the high temperature of the environment) thereby resulting in the reduction of the defects/damage produced. Our results present strong evidence for the applicability of YSZ as an inert matrix fuel in nuclear reactors, where competitive effects of radiation damage and dynamic thermal healing mechanisms may lead to a strong reduction in the damage production and thus sustain its physical integrity.

  12. The effects of hot carrier and swift heavy ion irradiation on electrical characteristics of advanced 200 GHz SiGe HBTs

    Energy Technology Data Exchange (ETDEWEB)

    Vinayakprasanna, N. H.; Praveen, K. C.; Prakash, A. P. Gnana, E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore-570006 (India); Cressler, J. D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta-30332, GA (United States)

    2016-05-23

    The 200 GHz SiGe HBTs were irradiated with 80 MeV Carbon ions up to a total dose of 100 Mrad to understand the degradation in electrical characteristics. The degradation in the electrical characteristics of SiGe HBTs was also studied by mixed mode electrical stress up to 10,000 s. The electrical characteristics were measured before and after every total dose and after fixed stress time. The normalized peak h{sub FE} of the stressed and irradiated SiGe HBTs are compared to estimate the equivalent stress time for a particular total dose. These correlations are drawn for the first time and the results will establish a systematic relation between stress time and total dose.

  13. The effects of hot carrier and swift heavy ion irradiation on electrical characteristics of advanced 200 GHz SiGe HBTs

    International Nuclear Information System (INIS)

    Vinayakprasanna, N. H.; Praveen, K. C.; Prakash, A. P. Gnana; Cressler, J. D.

    2016-01-01

    The 200 GHz SiGe HBTs were irradiated with 80 MeV Carbon ions up to a total dose of 100 Mrad to understand the degradation in electrical characteristics. The degradation in the electrical characteristics of SiGe HBTs was also studied by mixed mode electrical stress up to 10,000 s. The electrical characteristics were measured before and after every total dose and after fixed stress time. The normalized peak h_F_E of the stressed and irradiated SiGe HBTs are compared to estimate the equivalent stress time for a particular total dose. These correlations are drawn for the first time and the results will establish a systematic relation between stress time and total dose.

  14. Guided-wave phase-matched second-harmonic generation in KTiOPO4 waveguide produced by swift heavy-ion irradiation

    Science.gov (United States)

    Cheng, Yazhou; Jia, Yuechen; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng

    2014-11-01

    We report on the guided-wave second-harmonic generation in a KTiOPO4 nonlinear optical waveguide fabricated by a 17 MeV O5+ ion irradiation at a fluence of 1.5×1015 ions/cm2. The waveguide guides light along both TE and TM polarizations, which is suitable for phase-matching frequency doubling. Second harmonics of green light at a wavelength of 532 nm have been generated through the KTiOPO4 waveguide platform under an optical pump of fundamental wave at 1064 nm in both continuous-wave and pulsed regimes, reaching optical conversion efficiencies of 5.36%/W and 11.5%, respectively. The propagation losses have been determined to be ˜3.1 and ˜5.7 dB/cm for the TE and TM polarizations at a wavelength of 632.8 nm, respectively.

  15. The effect of composition on the formation of light-emitting Si nanostructures in SiO{sub x} layers on irradiation with swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kachurin, G. A., E-mail: kachurin@isp.nsc.ru; Cherkova, S. G.; Marin, D. V.; Kesler, V. G. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation); Skuratov, V. A. [Joint Institute for Nuclear Research (Russian Federation); Cherkov, A. G. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

    2011-03-15

    The SiO{sub x} layers different in composition (0 < x < 2) are irradiated with Xe ions with the energy 167 MeV and the dose 10{sup 14} cm{sup -2} to stimulate the formation of light-emitting Si nanostructures. The irradiation gives rise to a photoluminescence band with the parameters dependent on x. As the Si content is increased, the photoluminescence is first enhanced, with the peak remaining arranged near the wavelength {lambda} Almost-Equal-To 600 nm, and then the peak shifts to {lambda} Almost-Equal-To 800 nm. It is concluded that the emission sources are quantum-confined nanoprecipitates formed by disproportionation of SiO{sub x} in ion tracks due to profound ionization losses. Changes in the photoluminescence spectrum with increasing x are attributed firstly to the increase in the probability of formation of nanoprecipitates and then to the increase in their dimensions; the latter effect is accompanied with a shift of the emission band to longer wavelengths. The subsequent quenching of photoluminescence is interpreted as a result of the removal of quantum confinement in nanoprecipitates and their coagulation.

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

    International Nuclear Information System (INIS)

    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

  17. Impact-parameter-dependent electronic stopping of swift ions

    NARCIS (Netherlands)

    Schinner, A.; Sigmund, P.

    2010-01-01

    A computational scheme has been developed to estimate the mean electronic energy loss of an incident swift ion on an atomic target as a function of the impact parameter between the moving nuclei. The theoretical basis is binary stopping theory. In order to extract impact-parameter dependencies it

  18. The effect of composition on the formation of light-emitting Si nanostructures in SiOx layers on irradiation with swift heavy ions

    International Nuclear Information System (INIS)

    Kachurin, G. A.; Cherkova, S. G.; Marin, D. V.; Kesler, V. G.; Skuratov, V. A.; Cherkov, A. G.

    2011-01-01

    The SiO x layers different in composition (0 14 cm −2 to stimulate the formation of light-emitting Si nanostructures. The irradiation gives rise to a photoluminescence band with the parameters dependent on x. As the Si content is increased, the photoluminescence is first enhanced, with the peak remaining arranged near the wavelength λ ≈ 600 nm, and then the peak shifts to λ ≈ 800 nm. It is concluded that the emission sources are quantum-confined nanoprecipitates formed by disproportionation of SiO x in ion tracks due to profound ionization losses. Changes in the photoluminescence spectrum with increasing x are attributed firstly to the increase in the probability of formation of nanoprecipitates and then to the increase in their dimensions; the latter effect is accompanied with a shift of the emission band to longer wavelengths. The subsequent quenching of photoluminescence is interpreted as a result of the removal of quantum confinement in nanoprecipitates and their coagulation.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

    Energy Technology Data Exchange (ETDEWEB)

    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. Nonlinear effects in interactions of swift ions with solids

    International Nuclear Information System (INIS)

    Crawford, O.H.; Dorado, J.J.; Flores, F.

    1994-01-01

    The passage of a swift charged particle through a solid gives rise to a wake of induced electron density behind the particle. It is calculated for a proton penetrating an electron gas having the density of the valence electrons in gold, assuming linear response of the medium. The induced potential associated with the wake is responsible for the energy loss of the particle, and for many effects that have captured recent interest. These include, among others, vicinage effects on swift ion clusters, emission of electrons from bombarded solids, forces on swift ions near a surface, and energy shifts in electronic states of channeled ions. Furthermore, the wake has a determining influence on the spatial distribution, and character, of energy deposition in the medium. Previous theoretical studies of these phenomena have employed a linear wake, i.e., one that is proportional to the charge of the projectile, eZ. However, in most experiments that measure these effects, the conditions are such that the wake must include higher-order terms in Z. The purpose of this study is to analyze the nonlinear wake, to understand how the linear results must be revised

  3. Conducting swift heavy ion track networks

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Kiv, A.; Fuks, D.; Vacík, Jiří; Hnatowicz, Vladimír; Chandra, A.; Saad, A.

    2010-01-01

    Roč. 165, č. 3 (2010), s. 227-244 ISSN 1042-0150 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : ion tracks * negative differential resistance * neural networks Subject RIV: JJ - Other Materials Impact factor: 0.660, year: 2010

  4. In-situ investigations of surface modifications by swift heavy ions

    International Nuclear Information System (INIS)

    Bolse, W.; Sankarakumar, A.; Ferhati, R.; Garmatter, D.; Haag, M.; Dautel, K.; Asdi, M.; Srivastava, N.; Widmann, B.; Bauer, M.

    2014-01-01

    We are running a High Resolution Scanning Electron Microscope in the beam line of the UNILAC ion accelerator at the GSI Helmholtz Centre for Heavy Ion Research in Danustadt, Germany, which has recently been extended also with an EDX-system and two micro-manipulators. This instrument allows us to in-situ investigate the structural and compositional development of individual objects and structures in the μm- and nm-range under swift heavy ion bombardment, from the very first ion impact up to high fluences of the order of several 10 15 /cm 2 . The sample under investigation is irradiated in small fluence steps and in between SEM-images (and EDX-scans) of one and the same surface area are taken. The irradiation can be carried out at any incidence angle between 0° and 90° and also under stepwise or continuous azimuthal rotation of the sample. The micro-manipulator system allows us to perform additional analysis like electrical and mechanical characterization as well as substrate-free EDX at sub-μm objects. We are now also able to irradiate almost free standing sub-μm structures (pasted on a nanoscale tip or held in micro-tweezers). In this report an overview over this unique instrument and its capabilities and advantages will be given, illustrated by the results of our recent in-situ studies on ion induced modification of thin films (dewetting and self-organisation) and on shaping of sub-μm objects with swift heavy ions (by taking advantage of ion sputtering, ion hammering and ion induced visco-elastic flow). (author)

  5. Enhanced formation of Ge nanocrystals in Ge : SiO2 layers by swift heavy ions

    International Nuclear Information System (INIS)

    Antonova, I V; Volodin, V A; Marin, D M; Skuratov, V A; Smagulova, S A; Janse van Vuuren, A; Neethling, J; Jedrzejewski, J; Balberg, I

    2012-01-01

    In this paper we report the ability of swift heavy Xe ions with an energy of 480 MeV and a fluence of 10 12 cm -2 to enhance the formation of Ge nanocrystals within SiO 2 layers with variable Ge contents. These Ge-SiO 2 films were fabricated by the co-sputtering of Ge and quartz sources which followed various annealing procedures. In particular, we found that the irradiation of the Ge : SiO 2 films with subsequent annealing at 500 °C leads to the formation of a high concentration of nanocrystals (NCs) with a size of 2-5 nm, whereas without irradiation only amorphous inclusions were observed. This effect, as evidenced by Raman spectra, is enhanced by pre-irradiation at 550 °C and post-irradiation annealing at 600 °C, which also leads to the observation of room temperature visible photoluminescence. (paper)

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

    International Nuclear Information System (INIS)

    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.

  7. Science and technology on the nanoscale with swift heavy ions in matter

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Reinhard, E-mail: r.neumann@gsi.de

    2013-11-01

    Swift heavy ions have stimulated developments of science and technology on the nanoscale due to the specific manner of transferring their kinetic energy in a solid successively in small portions along their trajectories. They thus create absolutely straight, almost cylindrical, and very narrow damage trails of diameter 5–10 nm. In various materials, such as polymers, a suitable etchant can transform these tracks into narrow channels of cylindrical, conical, or other desired shapes. These channels represent a starting point particularly for two major fields: they can be chemically modified to control small species and act, e.g., as sensors and transmitters of specific biomolecules. Irradiation of a sample with only one heavy ion allows the fabrication of single-nanochannel devices enabling measurements of enormous sensitivity. Filling nanochannels with a material provides nanowires. These objects of restricted dimensions exhibit finite-size and quantum behavior and give rise to a broad range of fundamental and applied research. This contribution briefly recollects microtechnological achievements with swift heavy ions that began already in the 1970s, preparing the ground for gradual size decrease down to the nanoscopic objects now under study. Various examples of material modifications on the nanoscale are presented, including recent results obtained with nanochannels and nanowires. Emerging developments are addressed, encompassing in situ recording of processes in biological cells stimulated by well-aimed ion irradiation, the fabrication of three-dimensional nanowire architectures, and plasmonic effects in nanowires.

  8. Structure and mechanical properties of swift heavy ion irradiated tungsten-bearing delta-phase oxides Y{sub 6}W{sub 1}O{sub 12} and Yb{sub 6}W{sub 1}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Tang, M., E-mail: mtang@lanl.gov [Materials Science and Technology Division, Mail-Stop G755, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Wynn, T.A. [Materials Physics and Application Division, Mail-Stop K771, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Patel, M.K.; Won, J. [Materials Science and Technology Division, Mail-Stop G755, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Monnet, I. [CIMAP, CEA-CNRS-ENSICAEN-Universite de Caen Normandie, Bd Henri Becquerel, BP 5133, F-14070, Caen Cedex 5 (France); Pivin, J.C. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CNRS-IN2P3-Universite Paris Sud, UMR 8609, Bat. 108, 91405 Orsay (France); Mara, N.A. [Materials Physics and Application Division, Mail-Stop K771, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Sickafus, K.E. [Materials Science and Technology Division, Mail-Stop G755, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-06-15

    We report on the relationship between structure and mechanical properties of complex oxides whose structures are derivatives of fluorite, following irradiation with swift heavy ion (92 MeV Xe) which approximately simulates fission product irradiation, where the electronic energy loss dominates. The two compounds of interest in this paper are Y{sub 6}W{sub 1}O{sub 12} and Yb{sub 6}W{sub 1}O{sub 12}. These compounds possess an ordered, fluorite derivative crystal structure known as the delta ({delta}) phase, a rhombohedral structure belonging to space group R3{sup Macron}. Structural changes induced by irradiation were examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD investigations indicated an irradiation-induced amorphization in these compounds. This result is consistent with our previous study on Y{sub 6}W{sub 1}O{sub 12} under displacive radiation environment in which the nuclear energy loss is dominant. High resolution TEM also revealed that individual ion tracks was amorphized. The mechanical properties of both irradiated compounds, were determined by cross-sectional nano-indentation measurements as a function of ion penetration depth. The decreases in Young's modulus, E, and hardness, H (both by about 40% at the irradiated surface) suggest amorphization beyond simple defect accumulation occurs under this irradiation condition.

  9. Structural modification by swift heavy ion at metal/Si interface

    Energy Technology Data Exchange (ETDEWEB)

    Sisodia, Veenu; Jain, R.K.; Bhattacharaya, D.; Kabiraj, D.; Jain, I.P. E-mail: ipjain46@sify.com

    2003-06-01

    Transition metal silicides produced by swift heavy ion (SHI) irradiation have found applications in ultra-large-scale integrated circuits due to their small contact resistivities and higher thermal and chemical stabilities. In the present work, the mixing in Ni/Si and Ti/Si systems was studied under irradiation with Au ions. A layer of Ni (15 nm) and Ti (18 nm) was deposited by e-gun evaporation on Si (1 0 0) substrate at 10{sup -8} Torr vacuum. The samples were irradiated with 95 Mev Au ions at room temperature to a fluence of 10{sup 13} ions/cm{sup 2} and 1 pna beam current. Rutherford backscattering spectroscopy and X-Ray reflectivity have been employed to characterize the samples. The large electronic excitation due to SHI irradiation produces defects in the system. It is expected that SHI irradiation followed by thermal annealing in Ni/Si system will provide the required energy to the atoms to diffuse across the interface resulting in mixing.

  10. Damage formation and annealing in InP due to swift heavy ions

    International Nuclear Information System (INIS)

    Kamarou, A.; Wesch, W.; Wendler, E.; Klaumuenzer, S.

    2004-01-01

    Virgin and pre-damaged InP samples were irradiated at room temperature (RT) and at liquid nitrogen temperature (LNT) with different fluences of 140 MeV Kr, 390 MeV Xe and 600 MeV Au ions. The pre-damaging was performed with 600 keV Ge ions at LNT to obtain different damage levels. The samples were analysed by means of Rutherford backscattering spectrometry (RBS) in random and channelling geometry. A relatively weak damage accumulation in virgin InP and a very significant defect annealing in pre-damaged InP occurs due to 140 MeV Kr irradiation. The damaging of virgin InP with 390 MeV Xe and 600 MeV Au is much more efficient in comparison with that of 140 MeV Kr. Further, annealing of the pre-damaged InP due to 390 MeV Xe irradiation is hardly visible. At LNT InP appears to be much more radiation-resistant to swift heavy ion (SHI) irradiation than at RT. Our results show that during SHI irradiation of InP both damage formation and damage annealing occur simultaneously. Whether the first or the second one plays a more important role depends on the SHI mass and energy

  11. Synthesis and characterization of graphene quantum dots and their size reduction using swift heavy ion beam

    Science.gov (United States)

    Mishra, Praveen; Bhat, Badekai Ramchandra

    2018-04-01

    Graphene quantum dots (GQDs) are nanosized fragments of graphene displaying quantum confinement effect. They have shown to be prepared from various methods which include ion beam etching of graphene. However, recently the modification of the GQDs has garnered tremendous attention owing to its suitability for various applications. Here, we have studied the effect of swift ion beam irradiation on the properties of GQDs. The ion beam treatment on the GQDs exhibited the change in observed photoluminescence of GQDs as they exhibited a blue luminescence on excitation with longwave UV (≈365 nm) due to the reduction in size and removal of the ethoxy (-C-O-C-) groups present on the quantum dots. This was confirmed by transmission electron microscopy, particle size analysis, and Fourier transform infrared spectroscopy.

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

    International Nuclear Information System (INIS)

    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)

  13. Effect of swift heavy ion irradiation on structural and magnetic properties of GdFe{sub 1−x}Ni{sub x}O{sub 3} (x≤0.2) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Pawanpreet [Department of Physics, National Institute of Technology, Hamirpur, H.P. 177005 (India); Sharma, K.K., E-mail: kknitham@gmail.com [Department of Physics, National Institute of Technology, Hamirpur, H.P. 177005 (India); Pandit, Rabia [Department of Physics, National Institute of Technology, Hamirpur, H.P. 177005 (India); Choudhary, R.J. [UGC-DAE Consortium for Scientific Research at Indore, M.P. 452 001 (India); Kumar, Ravi [Centre for Material Science and Engineering, National Institute of Technology, Hamirpur, H.P 177005 (India)

    2016-01-15

    The present work reports the effect of Ni doping and 200 MeV Ag{sup 15+} ion irradiation on the structural and magnetic properties of GdFe{sub 1−x}Ni{sub x}O{sub 3} (x≤0.2) thin films grown on SrTiO{sub 3} (001) substrate by pulse laser deposition (PLD). From the XRD patterns ‘c-axis’ oriented growth in the pristine films is noticed, whereas after irradiation amorphization in the films is noticed. The atomic force microscopic (AFM) images reveal the increase in surface roughness with doping and irradiation as well. The irreversibility in the zero field cooled and field cooled magnetic curves indicates to the possibility of magnetic disorder in all the pristine as well as irradiated samples. Magnetization has been found to decrease with increasing Ni{sup 3+} ion substitution at room temperature whereas an enhancement in magnetization is noticed after ion irradiation for all the films. The disparity in the magnetic properties of pristine GdFe{sub 1−x}Ni{sub x}O{sub 3} (0.0≤x≤0.2) orthoferrites thin films can be correlated to the difference in hybridization in transition metal ion and O{sup 2−} ion orbitals. However, presence of strains caused by the columnar defects is responsible for the change in structural, morphological and magnetic properties in the irradiated samples. - Highlights: • ‘c-axis’ oriented GdFe{sub 1−x}Ni{sub x}O{sub 3} (x≤0.2) thin films grown on SrTiO{sub 3} substrate. • Thin films have been irradiated by 200 MeV Ag{sup 15+} ions. • Presence of columnar defects have been estimated using SRIM. • Magnetic disorder in all the film samples have been seen at lower temperatures. • Structural and magnetic characteristics altered with doping and ion irradiation.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Effect of swift heavy O7+ ion radiations on conductivity of lithium based polymer blend electrolyte

    Science.gov (United States)

    Joge, Prajakta; Kanchan, D. K.; Sharma, Poonam; Jayswal, Manish; Avasthi, D. K.

    2014-07-01

    In the present work, effect of swift heavy O7+ ion of 80 MeV of different fluences, on conductivity of [PVA(47.5)-PEO(47.5)-LiCF3SO3(5)]-EC(8) polymeric films has been investigated using ac impedance spectroscopy. The power law exponent n, hopping frequency ωh and activation energies for conduction Eac and relaxation Ear, have been investigated for different fluences. The DSC measurements are carried out in order to investigate the variations in the degree of crystallinity and thermal parameters (Tm) of the blend specimen prior and after irradiation. The Fourier Transform Infrared (FT-IR) measurements are carried out in order to investigate the changes in the vibrational modes of molecules upon irradiation. The FT-IR measurements corroborate the formation of amorphous phase in the blend matrix after irradiation. The conductivity is found to be optimum at the fluence of 1×1012 ions/cm2. The enhancement and the improvement in the electrolytic properties of PVA-PEO blend upon O7+ ion irradiation have been observed.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  18. Effect of heavy ion irradiation on C 60

    Science.gov (United States)

    Lotha, S.; Ingale, A.; Avasthi, D. K.; Mittal, V. K.; Mishra, S.; Rustagi, K. C.; Gupta, A.; Kulkarni, V. N.; Khathing, D. T.

    1999-06-01

    Thin films of C 60 were subjected to swift heavy ion irradiation spanning the region from 2 to 11 keV/nm of electronic excitation. Studies of the irradiated films by Raman spectroscopy indicated polymerization and damage of the film with an ion fluence. The ion track radii are estimated for various ions using the Raman data. Photoluminescence spectroscopy of the irradiated film indicated a decrease in the C 60 phase with a dose, and an increase in the intensity at the 590 nm wavelength, which is attributed to an increase in the oxygen content.

  19. Advanced characterization of materials using swift ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tabacniks, Manfredo H. [Universidade de Sao Paulo (USP), SP (Brazil)

    2011-07-01

    Swift ion beams are powerful non destructive tools for material analysis especially thin films. In spite of their high energy, usually several MeV/u, little energy is deposited by the ion on the sample. Energetic ions also use to stop far away (or outside) the inspected volume, hence producing negligible damage to the sample. Ion beam methods provide quantitative trace element analysis of any atomic element (and some isotopes) in a sample and are able to yield elemental depth profiles with spatial resolution of the order of 10mm. Relying on nuclear properties of the atoms, these methods are insensitive to the chemical environment of the element, consequently not limited by matrix effects. Ion beam methods are multielemental, can handle insulating materials, are quick (an analysis usually takes less than 15 minutes), and need little (if any) sample preparation. Ion beams are also sensitive to surface roughness and sample porosity and can be used to quickly inspect these properties in a sample. The Laboratory for Ion Beam Analysis of the University of Sao Paulo, LAMFI, is a multi-user facility dedicated to provide Ion Beam Methods like PIXE, RBS, FRS and NRA techniques for the analysis of materials and thin films. Operating since 1994, LAMFI is being used mostly by many researchers from within and outside USP, most of them non specialists in ion beam methods, but in need of ion beam analysis to carry out their research. At LAMFI, during the last 9 years, more than 50% of the accelerator time was dedicated to analysis, usually PIXE or RBS. 21% was down time and about 14% of the time was used for the development of ion beam methods which includes the use of RBS for roughness characterization exploring the shading of the beam by structures on the surface and by modeling the RBS spectrum as the product of a normalized RBS spectrum and a height density distribution function of the surface. Single element thick target PIXE analysis is being developed to obtain the thin

  20. Advanced characterization of materials using swift ion beams

    International Nuclear Information System (INIS)

    Tabacniks, Manfredo H.

    2011-01-01

    Swift ion beams are powerful non destructive tools for material analysis especially thin films. In spite of their high energy, usually several MeV/u, little energy is deposited by the ion on the sample. Energetic ions also use to stop far away (or outside) the inspected volume, hence producing negligible damage to the sample. Ion beam methods provide quantitative trace element analysis of any atomic element (and some isotopes) in a sample and are able to yield elemental depth profiles with spatial resolution of the order of 10mm. Relying on nuclear properties of the atoms, these methods are insensitive to the chemical environment of the element, consequently not limited by matrix effects. Ion beam methods are multielemental, can handle insulating materials, are quick (an analysis usually takes less than 15 minutes), and need little (if any) sample preparation. Ion beams are also sensitive to surface roughness and sample porosity and can be used to quickly inspect these properties in a sample. The Laboratory for Ion Beam Analysis of the University of Sao Paulo, LAMFI, is a multi-user facility dedicated to provide Ion Beam Methods like PIXE, RBS, FRS and NRA techniques for the analysis of materials and thin films. Operating since 1994, LAMFI is being used mostly by many researchers from within and outside USP, most of them non specialists in ion beam methods, but in need of ion beam analysis to carry out their research. At LAMFI, during the last 9 years, more than 50% of the accelerator time was dedicated to analysis, usually PIXE or RBS. 21% was down time and about 14% of the time was used for the development of ion beam methods which includes the use of RBS for roughness characterization exploring the shading of the beam by structures on the surface and by modeling the RBS spectrum as the product of a normalized RBS spectrum and a height density distribution function of the surface. Single element thick target PIXE analysis is being developed to obtain the thin

  1. Spatial and energy distributions of the fragments resulting from the dissociation of swift molecular ions in solids

    International Nuclear Information System (INIS)

    Heredia-Avalos, Santiago; Garcia-Molina, Rafael; Abril, Isabel

    2002-01-01

    We have simulated the spatial evolution and energy loss of the fragments that result when swift molecular ions dissociate inside solid targets. In our calculations we have considered that these fragments undergo the following interactions: Coulomb repulsion (among like charged particles), stopping and wake forces (due to electronic excitations induced in the target), and nuclear scattering (with the target nuclei). We study the case of silicon targets irradiated with boron molecular or atomic ions; our results show that the main differences in the energy and spatial distributions of molecular fragments or atomic ions appear at shallow regions, and these tend to disappear at deeper depths

  2. Tailoring optical properties of TiO2-Cr co-sputtered films using swift heavy ions

    Science.gov (United States)

    Gupta, Ratnesh; Sen, Sagar; Phase, D. M.; Avasthi, D. K.; Gupta, Ajay

    2018-05-01

    Effect of 100 MeV Au7+ ion irradiation on structure and optical properties of Cr-doped TiO2 films has been studied using X-ray photoelectron spectroscopy, soft X-ray absorption spectroscopy, UV-Visible spectroscopy, X-ray reflectivity, and atomic force microscopy. X-ray reflectivity measurement implied that film thickness reduces as a function of ion fluence while surface roughness increases. The variation in surface roughness is well correlated with AFM results. Ion irradiation decreases the band gap energy of the film. Swift heavy ion irradiation enhances the oxygen vacancies in the film, and the extra electrons in the vacancies act as donor-like states. In valence band spectrum, there is a shift in the Ti3d peak towards lower energies and the shift is equivalent to the band gap energy obtained from UV spectrum. Evidence for band bending is also provided by the corresponding Ti XPS peak which exhibits a shift towards lower energy due to the downward band bending. X-ray absorption studies on O Kand Cr L3,2 edges clearly indicate that swift heavy ion irradiation induces formation of Cr-clusters in TiO2 matrix.

  3. Swift heavy ion induced modification of aliphatic polymers

    International Nuclear Information System (INIS)

    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

  4. The effect of He and swift heavy ions on nanocrystalline zirconium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Vuuren, A., E-mail: arnojvv@gmail.com [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Neethling, J.H. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Skuratov, V.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Uglov, V.V. [Belarusian State University, Minsk (Belarus); Petrovich, S. [VINCA Institute of Nuclear Sciences, Belgrade University, Belgrade (Serbia)

    2014-05-01

    Recent studies have shown that swift heavy ion irradiation may significantly modulate hydrogen and helium behaviour in some materials. This phenomenon is of considerable practical interest for ceramics in general and also for candidate materials for use as inert matrix fuel hosts. These materials will accumulate helium via (n, α) reactions and will also be subjected to irradiation by fission fragments. Cross-sectional transmission electron microscopy and scanning electron microscopy was used to study nanocrystalline ZrN irradiated with 30 keV He to fluences between 10{sup 16} and 5 × 10{sup 16} cm{sup −2}, 167 MeV Xe to fluences between 5 × 10{sup 13} and 10{sup 14} cm{sup −2} and also 695 MeV Bi to a fluence of 1.5 × 10{sup 13} cm{sup −2}. He/Bi and He/Xe irradiated samples were annealed at temperatures between 600 and 1000 °C and were analysed using SEM, XTEM and selected area diffraction. The results indicated that post irradiation heat treatment induces exfoliation at a depth that corresponds to the end-of-range of 30 keV He ions. SEM and XTEM analysis of He/Xe irradiated samples revealed that electronic excitation effects, due to Xe ions, suppress helium blister formation and consequently the exfoliation processes. He/Bi samples however do not show the same effects. This suggests that nanocrystalline ZrN is prone to the formation of He blisters which may ultimately lead material failure. These effects may however be mitigated by electronic excitation effects from certain SHIs.

  5. The effect of He and swift heavy ions on nanocrystalline zirconium nitride

    International Nuclear Information System (INIS)

    Janse van Vuuren, A.; Neethling, J.H.; Skuratov, V.A.; Uglov, V.V.; Petrovich, S.

    2014-01-01

    Recent studies have shown that swift heavy ion irradiation may significantly modulate hydrogen and helium behaviour in some materials. This phenomenon is of considerable practical interest for ceramics in general and also for candidate materials for use as inert matrix fuel hosts. These materials will accumulate helium via (n, α) reactions and will also be subjected to irradiation by fission fragments. Cross-sectional transmission electron microscopy and scanning electron microscopy was used to study nanocrystalline ZrN irradiated with 30 keV He to fluences between 10 16 and 5 × 10 16 cm −2 , 167 MeV Xe to fluences between 5 × 10 13 and 10 14 cm −2 and also 695 MeV Bi to a fluence of 1.5 × 10 13 cm −2 . He/Bi and He/Xe irradiated samples were annealed at temperatures between 600 and 1000 °C and were analysed using SEM, XTEM and selected area diffraction. The results indicated that post irradiation heat treatment induces exfoliation at a depth that corresponds to the end-of-range of 30 keV He ions. SEM and XTEM analysis of He/Xe irradiated samples revealed that electronic excitation effects, due to Xe ions, suppress helium blister formation and consequently the exfoliation processes. He/Bi samples however do not show the same effects. This suggests that nanocrystalline ZrN is prone to the formation of He blisters which may ultimately lead material failure. These effects may however be mitigated by electronic excitation effects from certain SHIs

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

    Science.gov (United States)

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

    2017-10-01

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

  7. Self-organised nano-structuring of thin oxide-films under swift heavy ion bombardment

    International Nuclear Information System (INIS)

    Bolse, Wolfgang

    2006-01-01

    Surface instabilities and the resulting self-organisation processes play an important role in nano-technology since they allow for large-array nano-structuring. We have recently found that the occurrence of such instabilities in thin film systems can be triggered by energetic ion bombardment and the subsequent self-assembly of the surface can be nicely controlled by fine-tuning of the irradiation conditions. The role of the ion in such processes is of double nature: If the instability is latently present already in the virgin sample, but self-assembly cannot take place because of kinetic barriers, the ion impact may just supply the necessary atomic mobility. On the other hand, the surface may become instable due to the ion beam induced material modifications and further irradiation then results in its reorganisation. In the present paper, we will review recently observed nano-scale self-organisation processes in thin oxide-films induced by the irradiation with swift heavy ions (SHI) at some MeV/amu energies. The first example is about SHI induced dewetting, which is driven by capillary forces already present in the as-deposited samples. The achieved dewetting pattern show an amazing similarity to those observed for liquid polymer films on Si, although in the present case the samples were kept at 80 K and hence have never reached their melting point. The second example is about self-organised lamellae formation driven by planar stresses, which are induced by SHI bombardment under grazing incidence and result in a surface instability and anisotropic plastic deformation (hammering effect). Taking advantage of these effects and modifying the irradiation procedure, we were able to generate more complex structures like NiO-'nano-towers' of 2 μm height and 200 nm in diameter

  8. The Erosion of Frozen Argon by Swift Helium Ions

    DEFF Research Database (Denmark)

    Besenbacher, F.; Bøttiger, Jørgen; Graversen, O.

    1981-01-01

    The temperature, energy, and thickness dependence of the erosion rates of frozen argon films when irradiated with 0.1–3 MeV helium ions have been measured. The erosion yields Y are much too high to be explained by the concentional collisional cascade-sputtering theory and are furthermore unequivo......The temperature, energy, and thickness dependence of the erosion rates of frozen argon films when irradiated with 0.1–3 MeV helium ions have been measured. The erosion yields Y are much too high to be explained by the concentional collisional cascade-sputtering theory and are furthermore...... unequivocally associated with electronic processes generated by the bombarding particle. In the present energy region, it is found that Y scales approximately as the electronic stopping power squared, depends on the charge state of the incoming helium ions, and perhaps more important, is independent...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  10. Electronic sputtering by swift highly charged ions of nitrogen on amorphous carbon

    International Nuclear Information System (INIS)

    Caron, M.; Haranger, F.; Rothard, H.; Ban d'Etat, B.; Boduch, P.; Clouvas, A.; Potiriadis, C.; Neugebauer, R.; Jalowy, T.

    2001-01-01

    Electronic sputtering with heavy ions as a function of both electronic energy loss dE/dx and projectile charge state q was studied at the French heavy ion accelerator GANIL. Amorphous carbon (untreated, and sputter-cleaned and subsequently exposed to nitrogen) was irradiated with swift highly charged ions (Z=6-73, q=6-54, energy 6-13 MeV/u) in an ultrahigh vacuum scattering chamber. The fluence dependence of ion-induced electron yields allows to deduce a desorption cross-section σ which varies approximately as σ∼(dE/dx) 1.65 or σ∼q 3.3 for sputter-cleaned amorphous carbon exposed to nitrogen. This q dependence is close to the cubic charge dependence observed for the emission of H + secondary ions which are believed to be emitted from the very surface. However, the power law σ∼(dE/dx) 1.65 , related to the electronic energy loss gives the best empirical description. The dependence on dE/dx is close to a quadratic one thus rather pointing towards a thermal evaporation-like effect

  11. Defect creation by swift heavy ions: materials modifications in the electronic stopping power regime

    International Nuclear Information System (INIS)

    Toulemonde, M.

    1994-01-01

    The material modifications by swift heavy ions in the electronic stopping power regime are puzzling question: How the energy deposited on the electrons can induced material modifications? In order to answer to this question, the modifications induced in non-radiolytic materials are described and compared to the predictions. In first part the main experimental observations is presented taking into account the irradiation parameters. Then it is shown that the initial phases of the material are very important. Amorphous materials, whatever it is a metal, a semiconductor or an insulator, are till now all sensitive to the high electronic excitation induced by the slowing down of a swift heavy ion. All oxide materials, insulators or conductors, are also sensitive even the MgO, one of most famous exceptions. Crystalline metals or semiconductors are intermediate cases: some are insensitive like Cu and Si respectively while Fe and GeS are sensitive. The main feature is the different values of the electronic stopping power threshold of material modifications. The evolution of the damage creation is described showing that the damage morphology seems to be the same whatever the material is amorphous or crystalline. In second part a try of interpretation of the experimental results will be done on the behalf of the two following models: The Coulomb spike and the thermal spike models. It will be shown that there is some agreement with limited predictions made in the framework of the Coulomb spike model. But it appears that the thermal spike model can account for most of the experimental data using only one free parameter: The electron-phonon strength which is a physical characteristic of the irradiated material. (author). 4 figs., 1 tab., 64 refs

  12. Effect of swift heavy ion irradiation on structural and opto-electrical properties of bi-layer CdS-Bi2S3 thin films prepared by solution growth technique at room temperature

    Science.gov (United States)

    Shaikh, Shaheed U.; Siddiqui, Farha Y.; Desale, Deepali J.; Ghule, Anil V.; Singh, Fouran; Kulriya, Pawan K.; Sharma, Ramphal

    2015-01-01

    CdS-Bi2S3 bi-layer thin films have been deposited by chemical bath deposition method on Indium Tin Oxide glass substrate at room temperature. The as-deposited thin films were annealed at 250 °C in an air atmosphere for 1 h. An air annealed thin film was irradiated using Au9+ ions with the energy of 120 MeV at fluence 5×1012 ions/cm2 using tandem pelletron accelerator. The irradiation induced modifications were studied using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Raman spectroscopy, UV spectroscopy and I-V characteristics. XRD study reveals that the as-deposited thin films were nanocrystalline in nature. The decrease in crystallite size, increase in energy band gap and resistivity were observed after irradiation. Results are explained on the basis of energy deposited by the electronic loss after irradiation. The comparative results of as-deposited, air annealed and irradiated CdS-Bi2S3 bi-layer thin films are presented.

  13. Determination of Hydrogen Density by Swift Heavy Ions.

    Science.gov (United States)

    Xu, Ge; Barriga-Carrasco, M D; Blazevic, A; Borovkov, B; Casas, D; Cistakov, K; Gavrilin, R; Iberler, M; Jacoby, J; Loisch, G; Morales, R; Mäder, R; Qin, S-X; Rienecker, T; Rosmej, O; Savin, S; Schönlein, A; Weyrich, K; Wiechula, J; Wieser, J; Xiao, G Q; Zhao, Y T

    2017-11-17

    A novel method to determine the total hydrogen density and, accordingly, a precise plasma temperature in a lowly ionized hydrogen plasma is described. The key to the method is to analyze the energy loss of swift heavy ions interacting with the respective bound and free electrons of the plasma. A slowly developing and lowly ionized hydrogen theta-pinch plasma is prepared. A Boltzmann plot of the hydrogen Balmer series and the Stark broadening of the H_{β} line preliminarily defines the plasma with a free electron density of (1.9±0.1)×10^{16}  cm^{-3} and a free electron temperature of 0.8-1.3 eV. The temperature uncertainty results in a wide hydrogen density, ranging from 2.3×10^{16} to 7.8×10^{18}  cm^{-3}. A 108 MHz pulsed beam of ^{48}Ca^{10+} with a velocity of 3.652  MeV/u is used as a probe to measure the total energy loss of the beam ions. Subtracting the calculated energy loss due to free electrons, the energy loss due to bound electrons is obtained, which linearly depends on the bound electron density. The total hydrogen density is thus determined as (1.9±0.7)×10^{17}  cm^{-3}, and the free electron temperature can be precisely derived as 1.01±0.04  eV. This method should prove useful in many studies, e.g., inertial confinement fusion or warm dense matter.

  14. Simulation study of radial dose due to the irradiation of a swift heavy ion aiming to advance the treatment planning system for heavy particle cancer therapy: The effect of emission angles of secondary electrons

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo, E-mail: moribayashi.kengo@jaea.go.jp

    2015-12-15

    A radial dose simulation model has been proposed in order to advance the treatment planning system for heavy particle cancer therapy. Here, the radial dose is the dose due to the irradiation of a heavy ion as a function of distances from this ion path. The model proposed here may overcome weak points of paradigms that are employed to produce the conventional radial dose distributions. To provide the radial dose with higher accuracy, this paper has discussed the relationship between the emission angles of secondary electrons and the radial dose. It is found that the effect of emission angles becomes stronger on the radial dose with increasing energies of the secondary electrons.

  15. Tracks induced by swift heavy ions in semiconductors

    International Nuclear Information System (INIS)

    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

  16. Positive ion irradiation facility

    International Nuclear Information System (INIS)

    Braby, L.A.

    1985-01-01

    Many questions about the mechanisms of the response of cells to ionizing radiation can best be investigated using monoenergetic heavy charged particle beams. Questions of the role of different types of damage in the LET effect, for example, are being answered by comparing repair kinetics for damage induced by electrons with that produced by helium ions. However, as the models become more sophicated, the differences between models can be detected only with more precise measurements, or by combining high- and low-LET irradiations in split-dose experiments. The design of the authors present cell irradiation beam line has limited the authors to irradiating cells in a partial vacuum. A new way to mount the dishes and bring the beam to the cells was required. Several means of irradiating cells in mylar-bottom dishes have been used at other laboratories. For example at the RARAF Facility, the dual ion experiments are done with the dish bottom serving as the beam exit window but the cells are in a partial vacuum to prevent breaking the window. These researchers have chosen instead to use the dish bottom as the beam window and to irradiate the entire dish in a single exposure. A special, very fast pumping system will be installed at the end of the beam line. This system will make it possible to irradiate cells within two minutes of installing them in the irradiation chamber. In this way, the interaction of electron and ion-induced damage in Chlamydomonas can be studied with time between doses as short as 5 minutes

  17. Effect of 100 MeV swift heavy ions [silver (Ag8+)] on morphological and electrical properties of polypyrrole

    Science.gov (United States)

    Kaur, Amarjeet; Dhillon, Anju; Avasthi, D. K.

    2009-10-01

    Polypyrrole (PPY) films were prepared by the electrochemical polymerization technique. The fully undoped samples were irradiated with different fluences ranging from 1010 to 1012 ions/cm2 of 100 MeV silver (Ag8+) ions. In order to explain the effect of these radiations, a comparative study of samples before and after irradiation was performed by using various techniques such as surface electron microscopy, atomic force microscopy, and X-ray diffraction. With an increase in fluence, the surface structure of PPY films becomes smoother, and the conductivity increases by two orders, which has been explained in light of reordering of polymer chains. The temperature dependence of the dc conductivity of irradiated as well as unirradiated samples has been investigated at 77-300 K. The charge transport properties before and after irradiation are retained although conductivity increases. It has been proposed that swift heavy ion irradiation affects the interchain conductivity. The conductivity of irradiated samples is stable under atmospheric conditions for more than 9 months. The present investigations open up the scope for the applicability of irradiated conducting polymers as microstructures with defined conductivity for sensor applications.

  18. Effect of 100 MeV swift heavy ions [silver (Ag8+)] on morphological and electrical properties of polypyrrole

    International Nuclear Information System (INIS)

    Kaur, Amarjeet; Dhillon, Anju; Avasthi, D. K.

    2009-01-01

    Polypyrrole (PPY) films were prepared by the electrochemical polymerization technique. The fully undoped samples were irradiated with different fluences ranging from 10 10 to 10 12 ions/cm 2 of 100 MeV silver (Ag 8+ ) ions. In order to explain the effect of these radiations, a comparative study of samples before and after irradiation was performed by using various techniques such as surface electron microscopy, atomic force microscopy, and X-ray diffraction. With an increase in fluence, the surface structure of PPY films becomes smoother, and the conductivity increases by two orders, which has been explained in light of reordering of polymer chains. The temperature dependence of the dc conductivity of irradiated as well as unirradiated samples has been investigated at 77-300 K. The charge transport properties before and after irradiation are retained although conductivity increases. It has been proposed that swift heavy ion irradiation affects the interchain conductivity. The conductivity of irradiated samples is stable under atmospheric conditions for more than 9 months. The present investigations open up the scope for the applicability of irradiated conducting polymers as microstructures with defined conductivity for sensor applications.

  19. Swift heavy ion induced modification of aliphatic polymers

    Energy Technology Data Exchange (ETDEWEB)

    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

  20. Modification of graphene by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bukowska, Hanna; Akcoeltekin, Sevilay; El Kharrazi, Mourad; Schleberger, Marika [Universitaet Duisburg-Essen, Fakultaet fuer Physik, Duisburg (Germany); Osmani, Orkhan [Universitaet Duisburg-Essen, Fakultaet fuer Physik, Duisburg (Germany); Technische Universitaet Kaiserslautern, Fachbereich Physik, Gottlieb-Daimler-Strasse, Gebaeude 47, 67663 Kaiserslautern (Germany)

    2010-07-01

    Ion irradiation can be used to modify surfaces on the nanometer scale. We investigate graphene on different insulator (SrTiO{sub 3}, TiO{sub 2}, and Al{sub 2}O{sub 3}) and semiconductor (SiO{sub 2}) substrates. The bombardment of those target surfaces with swift heavy ions under grazing angle of incidence creates chains of nanodots on the substrate and folds graphene to typical origami-like structures. The shape of the folded graphene seems to depend on the length of the tracks. The length can be controlled by the angle of incidence. From the analysis of atomic force microscopy measurements, we classify the different types of modifications, with the aim to determine the relationship between chain length and origami shape. Further more we want to develop a theoretical understanding of the physical processes leading to the folding.

  1. Silver ion beam irradiation effects on poly(lactide-co-glycolide) (PLGA)/clay nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet; Singh, Surinder [Guru Nanak Dev University, Department of Physics, Amritsar (India); Mehta, Rajeev [Thapar University, Department of Chemical Engineering, Patiala (India)

    2014-12-15

    Swift heavy ions induced modification of thin films of blends of poly(lactide-co-glycolide) (PLGA) (50:50) with organically modified nanoclay (Cloisite {sup registered} 30B) has been studied, using optical, structural and surface morphological analysis. Presence of nanoclay is found to enhance the properties of this degradable copolymer by reducing the rate of degradation even at high irradiation fluence. Optical and structural analysis of the polymer nanocomposites suggests that both the cross-linking and chain scission phenomenon are caused by swift heavy ion irradiation. XRD measurements show intercalation of PLGA in the clay galleries. Surface morphology of a nanocomposite indicates significant changes after irradiation at various fluences. (orig.)

  2. Light-emitting Si nanostructures formed by swift heavy ions in stoichiometric SiO2 layers

    Science.gov (United States)

    Kachurin, G. A.; Cherkova, S. G.; Marin, D. V.; Kesler, V. G.; Volodin, V. A.; Skuratov, V. A.

    2012-07-01

    Three hundred and twenty nanometer-thick SiO2 layers were thermally grown on the Si substrates. The layers were irradiated with 167 MeV Xe ions to the fluences ranging between 1012 cm-2 and 1014 cm-2, or with 700 MeV Bi ions in the fluence range of 3 × 1012-1 × 1013 cm-2. After irradiation the yellow-orange photoluminescence (PL) band appeared and grew with the ion fluences. In parallel optical absorption in the region of 950-1150 cm-1, Raman scattering and X-ray photoelectron spectroscopy evidenced a decrease in the number of Si-O bonds and an increase in the number of Si-coordinated atoms. The results obtained are interpreted as the formation of the light-emitting Si-enriched nanostructures inside the tracks of swift heavy ions through the disproportionation of SiO2. Ionization losses of the ions are regarded as responsible for the processes observed. Difference between the dependences of the PL intensity on the fluences of Xe and Bi ions are ascribed to their different stopping energy, therewith the diameters of the tracks of Xe and Bi ions were assessed as <3 nm and ˜10 nm, respectively. The observed shift of the PL bands, induced by Xe and Bi ions, agrees with the predictions of the quantum confinement theory.

  3. Light-emitting Si nanostructures formed by swift heavy ions in stoichiometric SiO{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Kachurin, G.A., E-mail: kachurin@isp.nsc.ru [A.V. Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk (Russian Federation); Cherkova, S.G. [A.V. Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk (Russian Federation); Marin, D.V. [A.V. Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Kesler, V.G. [A.V. Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk (Russian Federation); Volodin, V.A. [A.V. Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Skuratov, V.A. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

    2012-07-01

    Three hundred and twenty nanometer-thick SiO{sub 2} layers were thermally grown on the Si substrates. The layers were irradiated with 167 MeV Xe ions to the fluences ranging between 10{sup 12} cm{sup -2} and 10{sup 14} cm{sup -2}, or with 700 MeV Bi ions in the fluence range of 3 Multiplication-Sign 10{sup 12}-1 Multiplication-Sign 10{sup 13} cm{sup -2}. After irradiation the yellow-orange photoluminescence (PL) band appeared and grew with the ion fluences. In parallel optical absorption in the region of 950-1150 cm{sup -1}, Raman scattering and X-ray photoelectron spectroscopy evidenced a decrease in the number of Si-O bonds and an increase in the number of Si-coordinated atoms. The results obtained are interpreted as the formation of the light-emitting Si-enriched nanostructures inside the tracks of swift heavy ions through the disproportionation of SiO{sub 2}. Ionization losses of the ions are regarded as responsible for the processes observed. Difference between the dependences of the PL intensity on the fluences of Xe and Bi ions are ascribed to their different stopping energy, therewith the diameters of the tracks of Xe and Bi ions were assessed as <3 nm and {approx}10 nm, respectively. The observed shift of the PL bands, induced by Xe and Bi ions, agrees with the predictions of the quantum confinement theory.

  4. Light-emitting Si nanostructures formed by swift heavy ions in stoichiometric SiO2 layers

    International Nuclear Information System (INIS)

    Kachurin, G.A.; Cherkova, S.G.; Marin, D.V.; Kesler, V.G.; Volodin, V.A.; Skuratov, V.A.

    2012-01-01

    Three hundred and twenty nanometer-thick SiO 2 layers were thermally grown on the Si substrates. The layers were irradiated with 167 MeV Xe ions to the fluences ranging between 10 12 cm −2 and 10 14 cm −2 , or with 700 MeV Bi ions in the fluence range of 3 × 10 12 –1 × 10 13 cm −2 . After irradiation the yellow–orange photoluminescence (PL) band appeared and grew with the ion fluences. In parallel optical absorption in the region of 950–1150 cm −1 , Raman scattering and X-ray photoelectron spectroscopy evidenced a decrease in the number of Si–O bonds and an increase in the number of Si-coordinated atoms. The results obtained are interpreted as the formation of the light-emitting Si-enriched nanostructures inside the tracks of swift heavy ions through the disproportionation of SiO 2 . Ionization losses of the ions are regarded as responsible for the processes observed. Difference between the dependences of the PL intensity on the fluences of Xe and Bi ions are ascribed to their different stopping energy, therewith the diameters of the tracks of Xe and Bi ions were assessed as <3 nm and ∼10 nm, respectively. The observed shift of the PL bands, induced by Xe and Bi ions, agrees with the predictions of the quantum confinement theory.

  5. Universal scaling for biomolecule desorption induced by swift heavy ions

    International Nuclear Information System (INIS)

    Szenes, G.

    2005-01-01

    A thermal activation mechanism is proposed for the desorption of biomolecules. Good agreement is found with the experiments in a broad range of the electronic stopping power. The activation energies of desorption U are 0.33, 1.57 and 5.35 eV for positive, negative and neutral leucine molecules, respectively, and 2.05 eV for positive ergosterol molecules. The desorption of valine clusters is analyzed. The magnitude of the specific heat shows that the internal degrees of freedom are not excited up to the moment of desorption. The effect of irradiation temperature and of ion velocity on the desorption yield is discussed on the basis of the author's model. The scaling function derived in the model for the desorption of biomolecules is applied also to the sputtering of SiO 2 and U = 0.42 eV is obtained

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

    International Nuclear Information System (INIS)

    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

  7. Nucleation of 2D nanoislands in surface thermal spikes from swift heavy ions

    International Nuclear Information System (INIS)

    Volkov, Alexander E.; Sorokin, Michael V.

    2003-01-01

    Possibility of nucleation of nanoislands in the surface thermal spikes caused by swift heavy ions or intense femptosecond laser pulses is investigated. Nanoislands may occur when the characteristic nucleation time becomes shorter than that cooling down of the thermal spot. The values of system parameters favorable for the nucleation are estimated

  8. Investigation of the effects of swift heavy ion on the properties of yttrium calcium oxyborate (YCOB) NLO crystal

    International Nuclear Information System (INIS)

    Kalidasan, M.; Dhanasekaran, R.; Asokan, K.

    2012-01-01

    Heavy ion irradiation is a successful tool to create an effective refractive index change in a nonlinear optical (NLO) crystal surface in several micron thickness. It leads to the fabrication of non-leaky optical guiding structures. As irradiation can create the property changes with low ion fluence, it will be an alternative for the ion implantation. The present work is related to the creation of micrometer level surface modification in the YCa_4O(BO_3)_3 NLO crystal by the irradiation of 120 MeV Au"9"+ swift heavy ion and studying the changes in property of the material. The irradiation was carried out in the Materials Science beam line of the pelletron accelerator at Inter University Accelerator Centre, New Delhi. YCOB crystals were grown by high temperature flux technique in our laboratory. YCOB belongs to borate family of crystals which are superior to other NLO crystals due to their structural and optical features. Borate crystal can produce UV and deep UV laser through harmonic generation with good optical conversion efficiency. YCOB crystal attracted because of its high laser damage threshold, long nonlinear conversion length and large aperture scaling capability to be employed in high power laser applications. The Stopping and Range of Ions in Matter (SRIM) simulation has been carried out to study the variation of electronic (S_e) and nuclear (S_n) energy losses with penetration depth and energy of gold ions in YCOB crystal. Refractive index change was observed in the YCOB crystal due to the irradiation of 120 MeV Au"9"+ ion. The UV-Visible studies show optical band gap shift and confirms the refractive index change created in the YCOB crystal. The morphology of the irradiated crystal was analysed with scanning electron microscopy. The inhomogeneous broadening of emission curve of the YCOB crystal takes place due to ion irradiation which is analyzed in detail. From the fluorescence decay curves of pristine and irradiated crystals the excited state

  9. Experimental aspects of S.H.I.C. (Swift Heavy Ion Channeling)

    International Nuclear Information System (INIS)

    Quere, Y.; Mory, J.; Castro Faria, N.V. de; Chevallier, M.; Gaillard, M.J.; Genre, R.; Farizon-Mazuy, B.; Poizat, J.C.; Remillieux, J.; Dural, J.; Toulemonde, M.; Hage-Ali, M.

    1989-01-01

    We have studied the behaviour of swift heavy ions, of initial charge Z 0 , transmitted in a crystal. More precisely we have measured, for various values of Z 0 , the mean stopping power experienced by the ions of exit charge Z, together with the charge distribution n(Z). In this short note, we describe briefly the instrumental set-up, and give two specific results which make it possible to appreciate the accuracy and sensitivity of the experiment

  10. Radiation damage produced by swift heavy ions in rare earth phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Romanenko, Anton

    2017-02-13

    This work is devoted to the study of radiation damage produced by swift heavy ions in rare earth phosphates, materials that are considered as perspective for radioactive waste storage. Single crystals of rare earth phosphates were exposed to 2.1 GeV gold (Au) and 1.5 GeV xenon (Xe) ions of and analyzed mainly by Raman spectroscopy. All phosphates were found almost completely amorphous after the irradiation by 2.1 GeV Au ions at a fluence of 1 x 10{sup 13} ions/cm{sup 2}. Radiation-induced changes in the Raman spectra include the intensity decrease of all Raman bands accompanied by the appearance of broad humps and a reduction of the pronounced luminescence present in virgin samples. Analyzing the Raman peak intensities as a function of irradiation fluence allowed the calculation of the track radii for 2.1 GeV Au ions in several rare earth phosphates, which appear to be about 5.0 nm for all studied samples. Series of samples were studied to search for a trend of the track radius depending on the rare earth element (REE) cation. Among the monoclinic phosphates both Raman and small-angle X-ray scattering (SAXS) suggest no significant change of the track radius with increasing REE mass. In contrast, within the tetragonal phosphates Raman spectroscopy data suggests a possible slight decreasing trend of the track radius with the increase of REE atomic number. That finding, however, requires further investigation due to the low reliability of the qualitative Raman analysis. Detailed analysis of Raman spectra in HoPO{sub 4} showed the increase of peak width at the initial stage of the irradiation and subsequent decrease to a steady value at higher fluences. This observation suggested the existence of a defect halo around the amorphous tracks in HoPO{sub 4}. Raman peaks were found to initially shift to lower wavenumbers with reversing this trend at the fluence of 5 x 10{sup 11} for NdPO{sub 4} and 1 x 10{sup 12} ions/cm{sup 2} for HoPO{sub 4}. At the next fluence steps

  11. Radiation damage produced by swift heavy ions in rare earth phosphates

    International Nuclear Information System (INIS)

    Romanenko, Anton

    2017-01-01

    This work is devoted to the study of radiation damage produced by swift heavy ions in rare earth phosphates, materials that are considered as perspective for radioactive waste storage. Single crystals of rare earth phosphates were exposed to 2.1 GeV gold (Au) and 1.5 GeV xenon (Xe) ions of and analyzed mainly by Raman spectroscopy. All phosphates were found almost completely amorphous after the irradiation by 2.1 GeV Au ions at a fluence of 1 x 10 13 ions/cm 2 . Radiation-induced changes in the Raman spectra include the intensity decrease of all Raman bands accompanied by the appearance of broad humps and a reduction of the pronounced luminescence present in virgin samples. Analyzing the Raman peak intensities as a function of irradiation fluence allowed the calculation of the track radii for 2.1 GeV Au ions in several rare earth phosphates, which appear to be about 5.0 nm for all studied samples. Series of samples were studied to search for a trend of the track radius depending on the rare earth element (REE) cation. Among the monoclinic phosphates both Raman and small-angle X-ray scattering (SAXS) suggest no significant change of the track radius with increasing REE mass. In contrast, within the tetragonal phosphates Raman spectroscopy data suggests a possible slight decreasing trend of the track radius with the increase of REE atomic number. That finding, however, requires further investigation due to the low reliability of the qualitative Raman analysis. Detailed analysis of Raman spectra in HoPO 4 showed the increase of peak width at the initial stage of the irradiation and subsequent decrease to a steady value at higher fluences. This observation suggested the existence of a defect halo around the amorphous tracks in HoPO 4 . Raman peaks were found to initially shift to lower wavenumbers with reversing this trend at the fluence of 5 x 10 11 for NdPO 4 and 1 x 10 12 ions/cm 2 for HoPO 4 . At the next fluence steps peaks moved in the other direction, passed

  12. Swift Heavy Ion Induced Modification of Aliphatic Polymers

    OpenAIRE

    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...

  13. Low energy ion implantation and high energy heavy ion irradiation in C60 films

    International Nuclear Information System (INIS)

    Narayanan, K.L.; Yamaguchi, M.; Dharmarasu, N.; Kojima, N.; Kanjilal, D.

    2001-01-01

    C 60 films have been bombarded with low energy boron ions and high energy swift heavy ions (SHI) of silver and oxygen at different doses. Raman scattering and Fourier transform infrared (FTIR) studies were carried out on the virgin and irradiated films and the results are in good agreement with each other. The films subject to low energy boron ion implantation showed destruction of the bukky balls whereas the films subject to high energy ion irradiation did not show appreciable effects on their structure. These results indicate that C 60 films are more prone to defects by elastic collision and subsequent implantation at lower energy. Irradiation at higher energy was less effective in creating appreciable defects through electronic excitation by inelastic collisions at similar energy density

  14. Femto-clock for the electron kinetics in swift heavy ion tracks

    Czech Academy of Sciences Publication Activity Database

    Medvedev, Nikita; Volkov, A.E.

    2017-01-01

    Roč. 50, č. 44 (2017), s. 1-11, č. článku 445302. ISSN 0022-3727 R&D Projects: GA MŠk LG15013; GA MŠk(CZ) LM2015083 Institutional support: RVO:68378271 Keywords : swift heavy ions * electron kinetics * femto-clock * femtosecond resolution * spectroscopy * radiative decay Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.588, year: 2016

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Excitation of swift heavy ions in foil targets IV

    International Nuclear Information System (INIS)

    Bridwell, L.B.; Pender, L.F.; Sofield, C.J.; Hay, H.J.; Treacy, P.B.

    1988-05-01

    Studies have been made of the approach to energy-loss and charge-state equilibrium of initially pure charge states of ions, transmitted through thin carbon targets. Ions of Li, F and Cl at 3 MeV per AMU were used. Detailed observations were made of outgoing energy losses and charge-state distributions, for outgoing charges equal to those ingoing. A Monte Carlo analysis is made of the charge-changing processes, which allows calculation of energy losses due to projectile charge exchange. The residual electronic target-ionisation loss is analysed to predict in-target charge states of the projectile ions. Using these, a comparison is made between the in-target effective charge for target ionisation, and the averaged ionic charge which fits charge-exchange data

  17. A comparative investigation on ion impact parameters and TL response of Y{sub 2}O{sub 3}:Tb{sup 3+} nanophosphor exposed to swift heavy ions for space dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Som, S., E-mail: sudipta.som@gmail.com [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India); Dutta, S.; Chowdhury, M. [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India); Kumar, Vijay; Kumar, Vinod; Swart, H.C. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Sharma, S.K., E-mail: sksharma.ism@gmail.com [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India)

    2014-03-15

    Highlights: • This paper discusses the SHI induced effect on thermoluminescence properties. • Ni{sup 7+}, Ag{sup 9+} and Au{sup 8+} ions are chosen for irradiation purpose. • Comparison between these ions effect is carried out. • Au{sup 8+} ion is more pronounced and suitable for space dosimetry in Y{sub 2}O{sub 3}:Tb{sup 3+}. -- Abstract: This paper reports on a comparative study on the structural and thermoluminescence (TL) modifications of Y{sub 2}O{sub 3}:Tb{sup 3+} phosphor induced by 150 MeV Ni{sup 7+}, 120 MeV Ag{sup 9+} and 110 MeV Au{sup 8+} swift heavy ions in the fluence range 1 × 10{sup 11}–1 × 10{sup 13} ions/cm{sup 2}. SRIM calculations were performed in order to correlate the change in TL properties of various ions irradiated phosphors. It shows that the 110 MeV Au{sup 8+} ions created a high concentration of defects. X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopic studies confirm the loss of crystallinity of the phosphors after ions irradiation, which is high in the case of the Au{sup 8+} ion irradiation. Structural refinement by Rietveld method yields the various structural parameters of the ion irradiated phosphors. TL glow curves of the ion irradiated phosphors show a small shift in the position of the peaks along with an increase in intensity with the increase in ions fluence. Trapping parameters of the ions irradiated phosphors were calculated from the TL data using various glow curve analysis methods. The results can be correlated on the basis of the linear energy transfer of the irradiated ions. These obtained results can be used successfully in heavy ions dosimetry for space craft and air crew.

  18. Charge-state related effects in sputtering of LiF by swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W. [Ludwig-Maximilians-Universität München, 85748 Garching (Germany); Ban-d' Etat, B. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Bender, M. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Boduch, P. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Grande, P.L. [Univ. Fed. Rio Grande do Sul, BR-91501970 Porto Alegre, RS (Brazil); Lebius, H.; Lelièvre, D. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Marmitt, G.G. [Univ. Fed. Rio Grande do Sul, BR-91501970 Porto Alegre, RS (Brazil); Rothard, H. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Seidl, T.; Severin, D.; Voss, K.-O. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Toulemonde, M., E-mail: toulemonde@ganil.fr [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Trautmann, C. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2017-02-01

    Sputtering experiments with swift heavy ions in the electronic energy loss regime were performed by using the catcher technique in combination with elastic recoil detection analysis. The angular distribution of particles sputtered from the surface of LiF single crystals is composed of a jet-like peak superimposed on a broad isotropic distribution. By using incident ions of fixed energy but different charges states, the influence of the electronic energy loss on both components is probed. We find indications that isotropic sputtering originates from near-surface layers, whereas the jet component may be affected by contributions from depth up to about 150 nm.

  19. Ionisation and dissociation of water induced by swift multicharged ions

    International Nuclear Information System (INIS)

    Legendre, S.

    2006-02-01

    Ionization and dissociation of water molecules and water clusters induced by 11.7 MeV/A Ni 25+ ions were carried out by imaging techniques. Branching ratios, ionisation cross sections and Kinetic Energy Released distributions have been measured together with fragmentation dynamics studies. Multiple ionization represents approximately 30% of the ionizing events. Double ionization produces in significant way atomic oxygen, considered as a possible precursor of the large production of HO 2 radical in liquid water radiolysis by ions of high Linear Energy Transfer. We evidence a strong selectivity of bond breakage in the case of ion-induced HOD fragmentation. Once the molecule doubly ionized, the breakage of the O-H bond is found 6.5 times more probable than that of the O-D bond. A semi-classical calculation simulating the fragmentation dynamics on the potential energy surface of the ground-state of di-cation H 2 O 2+ makes possible to as well reproduce the preferential nature of the breakage of the O-H bond as the position and the shift of the kinetic energy distributions. First results concerning interaction with water clusters are also reported. Measurements in coincidence are carried out giving access to correlation, with the distributions in energy and angle of the emitted fragments. Mass spectrum points fast intra-cluster proton transfer, leading to the emission of protonated clusters. (author)

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

    International Nuclear Information System (INIS)

    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

  1. Phase transformations in Ln2O3 materials irradiated with swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Tracy, Cameron L.; Lang, Maik; Zhang, Fuxiang; Trautmann, Christina; Ewing, Rodney C.

    2015-11-01

    Phase transformations induced in the cubic C-type lanthanide sesquioxides, Ln 2 O 3 (Ln = Sm, Gd, Ho, Tm, and Lu), by dense electronic excitation are investigated. The structural modifications resulting from exposure to beams of 185 MeV Xe and 2246 MeV Au ions are characterized using synchrotron x-ray diffraction and Raman spectroscopy. The formation of a B-type polymorph, an X-type nonequilibrium phase, and an amorphous phase are observed. The specific phase formed and the transformation rate show dependence on the material composition, as well as the ion beam mass and energy. Atomistic mechanisms for these transformations are determined, indicating that formation of the B-type phase results from the production of anti-Frenkel defects and the aggregation of anion vacancies into planar clusters, whereas formation of the X-type and amorphous phases requires extensive displacement of both anions and cations. The observed variations in phase behavior with changing lanthanide ionic radius and deposited electronic energy density are related to the energetics of these transformation mechanisms.

  2. Calculation of electronic stopping power along glancing swift heavy ion tracks in perovskites using ab initio electron density data

    Energy Technology Data Exchange (ETDEWEB)

    Osmani, O; Duvenbeck, A; Akcoeltekin, E; Meyer, R; Schleberger, M [Department of Physics, University of Duisburg-Essen, D-47048 Duisburg (Germany); Lebius, H [CIMAP, blvd Henri Becquerel, 14070 Caen (France)], E-mail: marika.schleberger@uni-due.de

    2008-08-06

    In recent experiments the irradiation of insulators of perovskite type with swift (E{approx}100 MeV) heavy ions under glancing incidence has been shown to provide a unique means to generate periodically arranged nanodots at the surface. The physical origin of these patterns has been suggested as stemming from a highly anisotropic electron density distribution within the bulk. In order to show the relevance of the electron density distribution of the target we present a model calculation for the system Xe{sup 23+} {yields} SrTiO{sub 3} that is known to produce the aforementioned surface modifications. On the basis of the Lindhard model of electronic stopping, we employ highly-resolved ab initio electron density data to describe the conversion of kinetic energy into excitation energy along the ion track. The primary particle dynamics are obtained via integration of the Newtonian equations of motion that are governed by a space- and time-dependent frictional force originating from Lindhard stopping. The analysis of the local electronic stopping power along the ion track reveals a pronounced periodic structure. The periodicity length varies strongly with the particular choice of the polar angle of incidence and is directly correlated to the experimentally observed formation of periodic nanodots at insulator surfaces.

  3. Effect of 120 MeV Ag{sup 9+} ion irradiation of YCOB single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Arun Kumar, R., E-mail: rarunpsgtech@yahoo.com [Crystal Growth Centre, Anna University, Chennai 600 025 (India); Department of Basic Sciences - Physics Division, PSG College of Technology, Coimbatore 641 004 (India); Dhanasekaran, R. [Crystal Growth Centre, Anna University, Chennai 600 025 (India)

    2012-09-15

    Single crystals of yttrium calcium oxy borate (YCOB) grown from boron-tri-oxide flux were subjected to swift heavy ion irradiation using silver Ag{sup 9+} ions from the 15 UD Pelletron facility at Inter University Accelerator Center, New Delhi. The crystals were irradiated at 1 Multiplication-Sign 10{sup 13}, 5 Multiplication-Sign 10{sup 13} and 1 Multiplication-Sign 10{sup 14} ions/cm{sup 2} fluences at room temperature and with 5 Multiplication-Sign 10{sup 13} ions/cm{sup 2} fluence at liquid nitrogen temperature. The pristine and the irradiated samples were characterized by glancing angle X-ray diffraction, UV-Vis-NIR and photoluminescence studies. From the characterization studies performed on the samples, it is inferred that the crystals irradiated at liquid nitrogen temperature had fewer defects compared to the crystals irradiated at room temperature and the defects increased when the ion fluence was increased at room temperature.

  4. Differential multi-electron emission induced by swift highly charged gold ions penetrating carbon foils

    Science.gov (United States)

    Rothard, H.; Moshammer, R.; Ullrich, J.; Kollmus, H.; Mann, R.; Hagmann, S.; Zouros, T. J. M.

    2007-05-01

    First results on swift heavy ion induced electron emission from solids obtained with a reaction microscope are presented. This advanced technique, which is successfully used since quite some time to study electron ejection in ion-atom collisions, combines the measurement of the time-of-flight of electrons with imaging techniques. A combination of electric and magnetic fields guides the ejected electrons onto a position sensitive detector, which is capable to accept multiple hits. From position and time-of-flight measurement the full differential emission characteristics of up to 10 electrons per single incoming ion can be extracted. As a first example, we show energy spectra, angular distributions and the multiplicity distribution of electrons from impact of Au24+ (11 MeV/u) on a thin carbon foil (28 μg/cm2).

  5. Differential multi-electron emission induced by swift highly charged gold ions penetrating carbon foils

    International Nuclear Information System (INIS)

    Rothard, H.; Moshammer, R.; Ullrich, J.; Kollmus, H.; Mann, R.; Hagmann, S.; Zouros, T.J.M.

    2007-01-01

    First results on swift heavy ion induced electron emission from solids obtained with a reaction microscope are presented. This advanced technique, which is successfully used since quite some time to study electron ejection in ion-atom collisions, combines the measurement of the time-of-flight of electrons with imaging techniques. A combination of electric and magnetic fields guides the ejected electrons onto a position sensitive detector, which is capable to accept multiple hits. From position and time-of-flight measurement the full differential emission characteristics of up to 10 electrons per single incoming ion can be extracted. As a first example, we show energy spectra, angular distributions and the multiplicity distribution of electrons from impact of Au 24+ (11 MeV/u) on a thin carbon foil (28 μg/cm 2 )

  6. Simulation of the molecular recombination yield for swift H2+ ions through thin carbon foils

    International Nuclear Information System (INIS)

    Garcia-Molina, Rafael; Barriga-Carrasco, Manuel D.

    2003-01-01

    We have calculated the recombination yield for swift H 2 + molecular ions at the exit of thin amorphous carbon foils, as a function of the dwell time and incident energy. Our results are based on a detailed simulation of the motion through the target of the H 2 + molecular ion (before dissociation takes place) and its constituent fragments (after dissociation), including the following effects: Coulomb repulsion, nuclear scattering, electron capture and loss, as well as self-retarding and wake forces, which provide the relative distance and velocity of the dissociated fragments at the foil exit. The recombination of an H 2 + ion at the exit of the foil depends on the interproton separation and internal energy of the dissociated fragments, and on their probability to capture an electron. Comparison of our results with the available experimental data shows a good agreement

  7. Precise measurements of energy loss straggling for swift heavy ions in polymers

    Science.gov (United States)

    Rani, Bindu; Neetu; Sharma, Kalpana; Diwan, P. K.; Kumar, Shyam

    2016-11-01

    The energy loss straggling measurements for heavy ions with Z = 3-22 (∼0.2-2.5 MeV/u) in PEN (C7H5O2) and PET (C10H8O4) polymers have been carried out utilizing the swift heavy ion beam facility from 15UD Pelletron accelerator at Inter University Accelerator Centre (IUAC), New Delhi, India. The recorded spectra are analyzed in such a way that the Straggling associated with energy loss process could be measured in a systematic manner at any selected value of energy, in terms of per unit thickness of the absorber, at any desired energy intervals. The measured values have been compared with the calculated values obtained from the most commonly used Bethe-Livingston formulations applicable for collisional straggling. The results are tried to be understood in terms of the effective charge on the impinging ion within the absorber. Some interesting trends are observed.

  8. Sputtering from swift-ion trails in LiF: A hybrid PIC/MD simulation

    Energy Technology Data Exchange (ETDEWEB)

    Cherednikov, Yaroslav; Sun, Si Neng; Urbassek, Herbert M., E-mail: urbassek@rhrk.uni-kl.de

    2013-11-15

    We model the sputtering of a LiF crystal induced by swift-ion impact. The impinging ion creates a trail of doubly ionized F{sup +} ions, while simultaneously the corresponding electrons are set free. Ions move according to molecular dynamics, while excited electrons are treated by a particle-in-cell scheme. We treat the recombination time of electrons as a free parameter in our model. We find that the energy distribution of sputtered ions consists of 2 groups: a low-energy group centered at <1 eV, and a high-energy group at 7–8 eV. Fast ions (mainly Li{sup +}) are emitted early; these charge the surface negatively. Later, larger cluster ions and also neutral LiF molecules are emitted. Emission occurs at low angles to the surface normal. A jet along the normal direction can be observed, which is due to the electric field building up at the track surface. With increasing recombination time, processes are colder; sputtering decreases and the non-thermal jet structure becomes stronger.

  9. Allotropic effects on the energy loss of swift H+ and He+ ion beams through thin foils

    International Nuclear Information System (INIS)

    Garcia-Molina, Rafael; Abril, Isabel; Denton, Cristian D.; Heredia-Avalos, Santiago

    2006-01-01

    We have developed a theoretical treatment and a simulation code to study the energy loss of swift H + and He + ion beams interacting with thin foils of different carbon allotropes. The former is based on the dielectric formalism, and the latter combines Monte Carlo with the numerical solution of the motion equation for each projectile to describe its trajectory and interactions through the target. The capabilities of both methods are assessed by the reasonably good agreement between their predictions and the experimental results, for a wide range of projectile energies and target characteristics. Firstly, we apply the theoretical procedure to calculate the stopping cross sections for H + and He + beams in foils of different allotropic forms of carbon (such as diamond, graphite, amorphous carbon, glassy carbon and C 60 -fullerite), as a function of the projectile energy. We take into account the electronic structure of the projectile, as well as the different charge states it can acquire, the energy loss associated to the electronic capture and loss processes, the polarization of the projectile, and a realistic description of the target. On the other hand, the simulation code is used to evaluate the energy distributions of swift H + and He + ion beams when traversing several foils of the above mentioned allotropic forms of carbon, in order to analyze the influence of the chemical and physical state of the target in the projectile energy loss. These allotropic effects are found to become more important around the maximum of the stopping cross-section

  10. Melting of Au and Al in nanometer Fe/Au and Fe/Al multilayers under swift heavy ions: A thermal spike study

    International Nuclear Information System (INIS)

    Chettah, A.; Wang, Z.G.; Kac, M.; Kucal, H.; Meftah, A.; Toulemonde, M.

    2006-01-01

    Knowing that Fe is sensitive to swift heavy ion irradiations whereas Au and Al are not, the behavior of nanometric metallic multilayer systems, like [Fe(3 nm)/Au(x)] y and [Fe(3 nm)/Al(x)] y with x ranging between 1 and 10 nm, were studied within the inelastic thermal spike model. In addition to the usual cylindrical geometry of energy dissipation perpendicular to the ion projectile direction, the heat transport along the ion path was implemented in the electronic and atomic sub-systems. The simulations were performed using three different values of linear energy transfer corresponding to 3 MeV/u of 208 Pb, 132 Xe and 84 Kr ions. For the Fe/Au system, evidence of appearance of a molten phase was found in the entire Au layer, provided the Au thickness is less than 7 nm and 3 nm for Pb and Xe ions, respectively. For the Fe/Al(x) system irradiated with Pb ions, the Al layers with a thickness less than 4 nm melt along the entire ion track. Surprisingly, the Fe layer does not melt if the Al thickness is larger than 2 nm, although the deposited energy surpasses the electronic stopping power threshold of track formation in Fe. For Kr ions melting does not occur in any of the multilayer systems

  11. Velocity dependence of enhanced dynamic hyperfine field for Pd ions swiftly recoiling in magnetized Fe

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Ryan, G.C.; Bolotin, H.H.; Sie, S.H.

    1980-01-01

    The velocity-dependence of the magnitude of the enchanced dynamic hyperfine magnetic field (EDF) manifest at nuclei of 108 Pd ions swiftly recoiling through thin magnetized Fe has been investigated at ion velocities higher than have heretofore been examined for the heavier nuclides (i.e., at initial recoil velocities (v/Zv 0 )=0.090 and 0.160, v 0 =c/137). These results for 108 Pd, when taken in conjunction with those of prior similar measurements for 106 Pd at lower velocities, and fitted to a velocity dependence for the EDF, give for the Pd isotopes over the extended velocity range 1.74 0 )<=7.02, p=0.41+-0.15; a result incompatible with previous attributions of a linear velocity dependence for the field

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

    Indian Academy of Sciences (India)

    Administrator

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

  13. Effect of swift heavy ion irradiation on surface resistance of ...

    Indian Academy of Sciences (India)

    ... Larkin–Ovchinnikov scenario [5] where the effective pinning force on the FLL is given by BJc(H)=(np〈 f 2〉/Vc)1/2 where np is the density of pinning centers, f the ele- mentary pinning force parameter and Vc the Larkin volume over which the FLL maintains its spatial order. We have shown in an earlier communication [6] ...

  14. Dynamics of solid inner-shell electrons in collisions with bare and dressed swift ions

    International Nuclear Information System (INIS)

    Montanari, C.C.; Miraglia, J. E.; Arista, N.R.

    2002-01-01

    We analyze the dynamical interactions of swift heavy projectiles and solid inner-shell electrons. The dielectric formalism employed to deal with the free-electron gas is extended to account for the core electrons, by using the local plasma approximation. Results for stopping power, energy straggling, and inner-shell ionization in collisions of bare ions with metals are displayed, showing very good accord with the experimental data. Simultaneous excitations of projectile and target electrons are also analyzed. In the high-energy range we find a similar contribution of target core and valence electrons to the probability of projectile-electron loss. The problem of no excitation threshold within the local plasma approximation and the possibility of collective excitations of the shells are discussed

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

    International Nuclear Information System (INIS)

    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

  16. Precise measurements of energy loss straggling for swift heavy ions in polymers

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Bindu [Department of Physics, Kurukshetra University, Kurukshetra 136 119 (India); Neetu [Department of Physics, S.D College, Panipat 132103 (India); Sharma, Kalpana [Department of Physics, CMR Institute of Technology, Bangalore 560037 (India); Diwan, P.K. [Department of Applied Sciences, UIET, Kurukshetra University, Kurukshetra 136 119 (India); Kumar, Shyam, E-mail: profshyam@gmail.com [Department of Physics, Kurukshetra University, Kurukshetra 136 119 (India)

    2016-11-15

    The energy loss straggling measurements for heavy ions with Z = 3–22 (∼0.2–2.5 MeV/u) in PEN (C{sub 7}H{sub 5}O{sub 2}) and PET (C{sub 10}H{sub 8}O{sub 4}) polymers have been carried out utilizing the swift heavy ion beam facility from 15UD Pelletron accelerator at Inter University Accelerator Centre (IUAC), New Delhi, India. The recorded spectra are analyzed in such a way that the Straggling associated with energy loss process could be measured in a systematic manner at any selected value of energy, in terms of per unit thickness of the absorber, at any desired energy intervals. The measured values have been compared with the calculated values obtained from the most commonly used Bethe-Livingston formulations applicable for collisional straggling. The results are tried to be understood in terms of the effective charge on the impinging ion within the absorber. Some interesting trends are observed.

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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.

  19. In-situ electric resistance measurements and annealing effects of graphite exposed to swift heavy ions

    International Nuclear Information System (INIS)

    Fernandes, Sandrina; Pellemoine, Frederique; Tomut, Marilena; Avilov, Mikhail; Bender, Markus; Boulesteix, Marine; Krause, Markus; Mittig, Wolfgang; Schein, Mike; Severin, Daniel; Trautmann, Christina

    2013-01-01

    To study the suitability of using graphite as material for high-power targets for rare isotope production at the future Facility for Rare Isotope Beams (FRIB) in the USA and at the Facility for Antiproton and Ion Research (FAIR) in Germany, thin foils of polycrystalline graphite were exposed to 8.6-MeV/u Au ions reaching a maximum fluence of 1 × 10 15 ions/cm 2 . Foil irradiation temperatures of up to 1800 °C were obtained by ohmic heating. In-situ monitoring of the electrical resistance of the graphite foils during and after irradiation provided information on beam-induced radiation damage. The rate of electrical resistance increase as a function of fluence was found to decrease with increasing irradiation temperature, indicating a more efficient annealing of the irradiation-produced defects. This is corroborated by the observation that graphite foils irradiated at temperatures below about 800 °C showed cracks and pronounced deformations, which did not appear on the samples irradiated at higher temperatures

  20. Effect of swift heavy Kr ions on complex permittivity of silicon PIN diode

    International Nuclear Information System (INIS)

    Li, Yun; Su, Ping; Yang, Zhimei; Ma, Yao; Gong, Min

    2016-01-01

    Highlights: • The complex permittivity has been studied on Si PIN irradiated by heavy Kr ions. • DLTS was used to investigate damages formed in PIN diode during irradiation. • The recombination of carriers has important influence on the complex permittivity. - Abstract: The complex permittivity has been researched on silicon PIN diodes irradiated by 2150 MeV heavy Kr ions in this article. The difference of complex permittivity spectra from 1 to 10^7 Hz between irradiated and unirradiated were observed and discussed. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics were measured at room temperature (300 K) to study the change of electrical properties in diode after irradiation. Deep level transient spectroscopy (DLTS) was used to investigate damages caused by 2150 MeV heavy Kr ions in diode. Two extra electron traps were observed, which were located at E C -0.31 eV and E C -0.17 eV. It indicated that new defects have been formed in PIN diode during irradiation. A comparison of the results illustrated that not only the carrier density but also the recombination of electron-hole pair have important influences on the properties of complex permittivity. These results offer a further indication of the mechanism about the complex permittivity property of semiconductor device, which could help to make the applications for the semiconductor device controlled by electric signals come true in the fields of optoelectronic integrated circuits, plasma antenna and so on.

  1. In-situ electric resistance measurements and annealing effects of graphite exposed to swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Sandrina [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI (United States); Pellemoine, Frederique, E-mail: pellemoi@frib.msu.edu [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI (United States); Tomut, Marilena [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); National Institute for Materials Physics (NIMP), Bucharest (Romania); Avilov, Mikhail [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI (United States); Bender, Markus [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Boulesteix, Marine [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI (United States); Krause, Markus [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Technische Universität, Darmstadt (Germany); Mittig, Wolfgang [National Superconducting Cyclotron Lab (NSCL), Michigan State University, East Lansing, MI (United States); Schein, Mike [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI (United States); Severin, Daniel [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Trautmann, Christina [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Technische Universität, Darmstadt (Germany)

    2013-11-01

    To study the suitability of using graphite as material for high-power targets for rare isotope production at the future Facility for Rare Isotope Beams (FRIB) in the USA and at the Facility for Antiproton and Ion Research (FAIR) in Germany, thin foils of polycrystalline graphite were exposed to 8.6-MeV/u Au ions reaching a maximum fluence of 1 × 10{sup 15} ions/cm{sup 2}. Foil irradiation temperatures of up to 1800 °C were obtained by ohmic heating. In-situ monitoring of the electrical resistance of the graphite foils during and after irradiation provided information on beam-induced radiation damage. The rate of electrical resistance increase as a function of fluence was found to decrease with increasing irradiation temperature, indicating a more efficient annealing of the irradiation-produced defects. This is corroborated by the observation that graphite foils irradiated at temperatures below about 800 °C showed cracks and pronounced deformations, which did not appear on the samples irradiated at higher temperatures.

  2. High fluence swift heavy ion structure modification of the SiO{sub 2}/Si interface and gate insulator in 65 nm MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yao [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Gao, Bo, E-mail: gaobo@scu.edu.cn [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Gong, Min [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Willis, Maureen [College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Yang, Zhimei [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); Guan, Mingyue [College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Li, Yun [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China)

    2017-04-01

    In this work, a study of the structure modification, induced by high fluence swift heavy ion radiation, of the SiO{sub 2}/Si structures and gate oxide interface in commercial 65 nm MOSFETs is performed. A key and novel point in this study is the specific use of the transmission electron microscopy (TEM) technique instead of the conventional atomic force microscope (AFM) or scanning electron microscope (SEM) techniques which are typically performed following the chemical etching of the sample to observe the changes in the structure. Using this method we show that after radiation, the appearance of a clearly visible thin layer between the SiO{sub 2} and Si is observed presenting as a variation in the TEM intensity at the interface of the two materials. Through measuring the EDX line scans we reveal that the Si:O ratio changed and that this change can be attributed to the migration of the Si towards interface after the Si-O bond is destroyed by the swift heavy ions. For the 65 nm MOSFET sample, the silicon substrate, the SiON insulator and the poly-silicon gate interfaces become blurred under the same irradiation conditions.

  3. Influence of high energy ion irradiation on fullerene derivative (PCBM) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Trupti, E-mail: tsphy91@gmail.com [Department of Physics, Malaviya National Institute of Technology, Jaipur 302017 (India); Singhal, Rahul; Vishnoi, Ritu [Department of Physics, Malaviya National Institute of Technology, Jaipur 302017 (India); Lakshmi, G.B.V.S. [Inter University Accelerator Centre, Post Box No. 10502, New Delhi 110067 (India); Biswas, S.K. [Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur 302017 (India)

    2017-04-01

    Highlights: • Spin casted PCBM thin films (∼100 nm) are irradiated with 55 MeV Si{sup 4+} ion beam. • The decrease in band gap is observed after irradiation. • The surface properties is also dependent on incident ion fluences. • Polymerization reactions induced by energetic ions leads to modifications. - Abstract: The modifications produced by 55 MeV Si{sup 4+} swift heavy ion irradiation on the phenyl C{sub 61} butyric acid methyl ester (PCBM) thin films (thickness ∼ 100 nm) has been enlightened. The PCBM thin films were irradiated at 1 × 10{sup 10}, 1 × 10{sup 11} and 1 × 10{sup 12} ions/cm{sup 2} fluences. After ion irradiation, the decreased optical band gap and FTIR band intensities were observed. The Raman spectroscopy reveals the damage produced by energetic ions. The morphological variation were investigated by atomic force microscopy and contact angle measurements and observed to be influenced by incident ion fluences. After 10{sup 11} ions/cm{sup 2} fluence, the overlapping of ion tracks starts and produced overlapping effects.

  4. Submicroscopic pores grafted using the residual sites produced by swift heavy ions

    International Nuclear Information System (INIS)

    Mazzei, R.; Betz, N.; Bermudez, G. Garcia; Massa, G.; Smolko, E.

    2005-01-01

    To produce nuclear track membranes (NTM) with submicroscopic pores poly(vinylidene difluoride) (PVDF) foils were irradiated with Cl, Ag and Pb ions. Then they were chemically etched for different times and grafted with acrylic acid. The grafting yields were determined by weight measurements as a function of ion fluence, etching time and also analysed using Fourier transform infrared spectroscopy. Both measurements suggest that the acrylic acid was grafted on the pore wall of the NTM using the active sites left by the ion beam

  5. Radiation stability of nanocrystalline ZrN coatings irradiated with high energy Xe and Bi ions

    International Nuclear Information System (INIS)

    Skuratov, V.A.; Sokhatsky, A.S.; Uglov, V.V.; Zlotski, S.V.; Van Vuuren, A.J.; Neethling, Jan; O'Connell, J.

    2011-01-01

    Swift Xe and Bi ion irradiation effects in nanocrystalline ZrN coatings as a function of ion fluence are reported. Zirconium nitride films of different thickness (0.1, 3, 10 and 20 micrometers) synthesized by vacuum arc-vapour deposition in nanocrystalline state (average size of crystallites is ∼4 nm) were irradiated with 167 MeV Xe and 695 MeV Bi ions to fluences in the range 3x10 12 ÷2.6x10 15 cm -2 (Xe) and 10 12 x10 13 cm -2 (Bi) and studied using XRD and TEM techniques. No evidence of amorphization due to high level ionizing energy losses has been found. The measurements of lattice parameter have revealed nonmonotonic dependence of the stress level in irradiated samples on ion fluence. (authors)

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Ion beam irradiation effects on aromatic polymers

    International Nuclear Information System (INIS)

    Shukushima, Satoshi; Ueno, Keiji

    1995-01-01

    We studied the optical and thermal properties of aromatic polymer films which had been irradiated with 1 MeV H + , H 2 + and He + ions. The examined aromatic polymers were polyetherether ketone(PEEK), polyetherimide(PEI), polyether sulfon(PES), polysulfon(PSF), and polyphenylene sulfide(PPS). The optical densities at 300nm of PES and PSF greatly increased after the irradiation. The optical densities at 400nm of all the examined polymer lineally increased with the irradiation dose. The PEEK film which had been irradiated with 1 MeV H + was not deformed above melting point. This demonstrates that cross-linking occurs in PEEK films by ion beam irradiation. As for the effects, depending on the mass of the irradiated ions, it was found that the ions with a high mass induced larger effects on the aromatic polymers for the same absorption energy. (author)

  9. Effect of ion irradiation on nanoscale TiS2 systems with suppressed Titania phase

    International Nuclear Information System (INIS)

    Hazarika, Saurabh J; Mohanta, Dambarudhar; Tripathi, A; Kanjilal, D.

    2016-01-01

    Titanium disulfide (TiS 2 ), being an important of the transition metal dichalcogenide, (TMDC) family, has drawn numerous interest owing to exhibition of tunable band gap as well as high carrier mobility. In this work, we highlight preparation of TiS 2 nanopowder with minimal TiO 2 content and also demonstrate modified properties upon swift heavy ion irradiation on TiS 2 nanoparticles dispersed PVA films. Different properties of the irradiated samples have been characterized through diffraction, microscopic and spectroscopic techniques. As a result of irradiation, due to agglomeration of particles, the grain size is found to increase. We could also observe a red shift after irradiation with increasing fluence, leading to easy flow of electron from valence to conduction band, which shows that conduction of electrons is more in case of irradiated films compared to the pristine one and thus there may be a possibility of using the irradiated samples in various optoelectronic devices. (paper)

  10. Coupled chemical reactions in dynamic nanometric confinement: VII. Biosensors based on swift heavy ion tracks with membranes

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Munoz, G. H.; García Arellano, H.; Alfonta, L.; Vacík, Jiří; Kiv, A.; Hnatowicz, Vladimír

    2017-01-01

    Roč. 172, 1-2 (2017), s. 159-173 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : biotechnology * tracks * swift heavy ions * polymers * etching Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nano-materials (production and properties) Impact factor: 0.443, year: 2016

  11. Effect of swift heavy Kr ions on complex permittivity of silicon PIN diode

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yun [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Su, Ping, E-mail: pingsu@scu.edu.cn [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Yang, Zhimei; Ma, Yao [Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Gong, Min, E-mail: mgong@scu.edu.cn [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Lab of Microelectronics Sichuan Province, Sichuan University, Chengdu, Sichuan 610064 (China); College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China)

    2016-12-01

    Highlights: • The complex permittivity has been studied on Si PIN irradiated by heavy Kr ions. • DLTS was used to investigate damages formed in PIN diode during irradiation. • The recombination of carriers has important influence on the complex permittivity. - Abstract: The complex permittivity has been researched on silicon PIN diodes irradiated by 2150 MeV heavy Kr ions in this article. The difference of complex permittivity spectra from 1 to 10^7 Hz between irradiated and unirradiated were observed and discussed. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics were measured at room temperature (300 K) to study the change of electrical properties in diode after irradiation. Deep level transient spectroscopy (DLTS) was used to investigate damages caused by 2150 MeV heavy Kr ions in diode. Two extra electron traps were observed, which were located at E{sub C}-0.31 eV and E{sub C}-0.17 eV. It indicated that new defects have been formed in PIN diode during irradiation. A comparison of the results illustrated that not only the carrier density but also the recombination of electron-hole pair have important influences on the properties of complex permittivity. These results offer a further indication of the mechanism about the complex permittivity property of semiconductor device, which could help to make the applications for the semiconductor device controlled by electric signals come true in the fields of optoelectronic integrated circuits, plasma antenna and so on.

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

    Science.gov (United States)

    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.

  13. Swift heavy ion induced modification in polycarbonate membrane for gas separation

    International Nuclear Information System (INIS)

    Rajesh Kumar; Prasad, Rajendra; Vijay, Y.K.; Das, D.

    2003-01-01

    Polymeric membranes are extensively used for commercial gas separation applications. Makrofol-KG (polycarbonate) is a glassy polymer. 40 μm thick sheet of Makrofol-KG was irradiated with 40 Ar (14.9 MeV/n) of fluence 10 3 ions/cm 2 and 20 μm thick sheet with 5.3 MeV α-particles of fluence 10 7 ions/cm 2 . The permeability of these polycarbonate membranes for H 2 and CO 2 was measured and also after etching in 6 N NaOH at 60 degC for different periods. Permeability is found to be increased with etching time. At a definite time, critical etching time, the permeability rapidly increases in PC. Positron annihilation lifetimes for unirradiated and irradiated membranes were measured with fast fast coincidence system to study the correlation of free volume hole concentration with gas separation properties. (author)

  14. Effects of model approximations for electron, hole, and photon transport in swift heavy ion tracks

    Energy Technology Data Exchange (ETDEWEB)

    Rymzhanov, R.A. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Medvedev, N.A., E-mail: nikita.medvedev@fzu.cz [Department of Radiation and Chemical Physics, Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Laser Plasma Department, Institute of Plasma Physics, Czech Academy of Sciences, Za Slovankou 3, 182 00 Prague 8 (Czech Republic); Volkov, A.E. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); National Research Centre ‘Kurchatov Institute’, Kurchatov Sq. 1, 123182 Moscow (Russian Federation); Lebedev Physical Institute of the Russian Academy of Sciences, Leninskij pr., 53,119991 Moscow (Russian Federation); National University of Science and Technology MISiS, Leninskij pr., 4, 119049 Moscow (Russian Federation); National Research Nuclear University MEPhI, Kashirskoye sh., 31, 115409 Moscow (Russian Federation)

    2016-12-01

    The event-by-event Monte Carlo code, TREKIS, was recently developed to describe excitation of the electron subsystems of solids in the nanometric vicinity of a trajectory of a nonrelativistic swift heavy ion (SHI) decelerated in the electronic stopping regime. The complex dielectric function (CDF) formalism was applied in the used cross sections to account for collective response of a matter to excitation. Using this model we investigate effects of the basic assumptions on the modeled kinetics of the electronic subsystem which ultimately determine parameters of an excited material in an SHI track. In particular, (a) effects of different momentum dependencies of the CDF on scattering of projectiles on the electron subsystem are investigated. The ‘effective one-band’ approximation for target electrons produces good coincidence of the calculated electron mean free paths with those obtained in experiments in metals. (b) Effects of collective response of a lattice appeared to dominate in randomization of electron motion. We study how sensitive these effects are to the target temperature. We also compare results of applications of different model forms of (quasi-) elastic cross sections in simulations of the ion track kinetics, e.g. those calculated taking into account optical phonons in the CDF form vs. Mott’s atomic cross sections. (c) It is demonstrated that the kinetics of valence holes significantly affects redistribution of the excess electronic energy in the vicinity of an SHI trajectory as well as its conversion into lattice excitation in dielectrics and semiconductors. (d) It is also shown that induced transport of photons originated from radiative decay of core holes brings the excess energy faster and farther away from the track core, however, the amount of this energy is relatively small.

  15. Damage nucleation in Si during ion irradiation

    International Nuclear Information System (INIS)

    Holland, O.W.; Fathy, D.; Narayan, J.

    1984-01-01

    Damage nucleation in single crystals of silicon during ion irradiation is investigated. Experimental results and mechanisms for damage nucleation during both room and liquid nitrogen temperature irradiation with different mass ions are discussed. It is shown that the accumulation of damage during room temperature irradiation depends on the rate of implantation. These dose rate effects are found to decrease in magnitude as the mass of the ions is increased. The significance of dose rate effects and their mass dependence on nucleation mechanisms is discussed

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-01

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

  17. Tailoring magnetism by light-ion irradiation

    International Nuclear Information System (INIS)

    Fassbender, J; Ravelosona, D; Samson, Y

    2004-01-01

    Owing to their reduced dimensions, the magnetic properties of ultrathin magnetic films and multilayers, e.g. magnetic anisotropies and exchange coupling, often depend strongly on the surface and interface structure. In addition, chemical composition, crystallinity, grain sizes and their distribution govern the magnetic behaviour. All these structural properties can be modified by light-ion irradiation in an energy range of 5-150 keV due to the energy loss of the ions in the solid along their trajectory. Consequently the magnetic properties can be tailored by ion irradiation. Similar effects can also be observed using Ga + ion irradiation, which is the common ion source in focused ion beam lithography. Examples of ion-induced modifications of magnetic anisotropies and exchange coupling are presented. This review is limited to radiation-induced structural changes giving rise to a modification of magnetic parameters. Ion implantation is discussed only in special cases. Due to the local nature of the interaction, magnetic patterning without affecting the surface topography becomes feasible, which may be of interest in applications. The main patterning technique is homogeneous ion irradiation through masks. Focused ion beam and ion projection lithography are usually only relevant for larger ion masses. The creation of magnetic feature sizes below 50 nm is shown. In contrast to topographic nanostructures the surrounding area of these nanostructures can be left ferromagnetic, leading to new phenomena at their mutual interface. Most of the material systems discussed here are important for technological applications. The main areas are magnetic data storage applications, such as hard magnetic media with a large perpendicular magnetic anisotropy or patterned media with an improved signal to noise ratio and magnetic sensor elements. It will be shown that light-ion irradiation has many advantages in the design of new material properties and in the fabrication technology of

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

    International Nuclear Information System (INIS)

    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)

  19. Effect of Xe ion (167 MeV) irradiation on polycrystalline SiC implanted with Kr and Xe at room temperature

    International Nuclear Information System (INIS)

    Hlatshwayo, T T; Kuhudzai, R J; Njoroge, E G; Malherbe, J B; O’Connell, J H; Skuratov, V A; Msimanga, M

    2015-01-01

    The effect of swift heavy ion (Xe 167 MeV) irradiation on polycrystalline SiC individually implanted with 360 keV Kr and Xe ions at room temperature to fluences of 2  ×  10 16 cm −2 and 1  ×  10 16 cm −2 respectively, was investigated using transmission electron microscopy (TEM), Raman spectroscopy and Rutherford backscattering spectrometry (RBS). Implanted specimens were each irradiated with 167 MeV Xe +26 ions to a fluence of 8.3  ×  10 14 cm −2 at room temperature. It was observed that implantation of 360 keV Kr and Xe ions individually at room temperature amorphized the SiC from the surface up to a depth of 186 and 219 nm respectively. Swift heavy ion (SHI) irradiation reduced the amorphous layer by about 27 nm and 30 nm for the Kr and Xe samples respectively. Interestingly, the reduction in the amorphous layer was accompanied by the appearance of randomly oriented nanocrystals in the former amorphous layers after SHI irradiation in both samples. Previously, no similar nanocrystals were observed after SHI irradiations at electron stopping powers of 33 keV nm −1 and 20 keV nm −1 to fluences below 10 14 cm −2 . Therefore, our results suggest a fluence threshold for the formation of nanocrystals in the initial amorphous SiC after SHI irradiation. Raman results also indicated some annealing of radiation damage after swift heavy ion irradiation and the subsequent formation of small SiC crystals in the amorphous layers. No diffusion of implanted Kr and Xe was observed after swift heavy ion irradiation. (paper)

  20. Optical transmission of silica glass during swift-heavy-ion implantation

    International Nuclear Information System (INIS)

    Plaksin, Oleg; Okubo, Nariaki; Takeda, Yoshihiko; Amekura, Hiroshi; Kono, Kenichiro; Kishimoto, Naoki

    2004-01-01

    Metal nanoparticles fabricated by heavy-ion implantation of insulators are promising for non-linear optical applications. Spectra of optical transmission of silica glass in the visible region were measured during and after implantation of 3 MeV Cu 2+ ions. Three absorption bands contribute to the spectra: transient absorption (TA) at 2.34 eV, a surface plasmon resonance (SPR) peak at 2.21 eV and a tail of residual absorption (RA), which increases when the photon energy is increased from 2.2 to 2.6 eV. The TA and a change of the SPR peak strongly contribute to the total transient absorption obtained as the difference in absorption during and after irradiation. The effect of RA shows up as a decrease of absorption after switching on the ion beam. The TA provides a means for selective electronic excitation by a laser during implantation of silica glass. The precipitation of Cu atoms and the growth of Cu nanoparticles are well distinguishable stages of nanoparticle formation. The SPR peak appears at a fluence of 3.3 x 10 16 ions/cm 2 , corresponding to the onset of precipitation. At fluences higher than 3.4 x 10 16 ions/cm 2 , when the growth of nanoparticles predominates, the fluence dependence of the SPR peak is linear

  1. Effect of 100 MeV swift Si8+ ions on structural and thermoluminescence properties of Y2O3:Dy3+nanophosphor

    Science.gov (United States)

    Shivaramu, N. J.; Lakshminarasappa, B. N.; Nagabhushana, K. R.; Singh, Fouran

    2016-05-01

    Nanoparticles of Y2O3:Dy3+ were prepared by the solution combustion method. The X-ray diffraction pattern of the 900°C annealed sample shows a cubic structure and the average crystallite size was found to be 31.49 nm. The field emission scanning electron microscopy image of the 900°C annealed sample shows well-separated spherical shape particles and the average particle size is found to be in a range 40 nm. Pellets of Y2O3:Dy3+ were irradiated with 100 MeV swift Si8+ ions for the fluence range of 3 × 1011_3 × 1013 ions cm-2. Pristine Y2O3:Dy3+ shows seven Raman modes with peaks at 129, 160, 330, 376, 434, 467 and 590 cm-1. The intensity of these modes decreases with an increase in ion fluence. A well-resolved thermoluminescence glow with peaks at ∼414 K (Tm1) and ∼614 K (Tm2) were observed in Si8+ ion-irradiated samples. It is found that glow peak intensity at 414 K increases with an increase in the dopant concentration up to 0.6 mol% and then decreases with an increase in dopant concentration. The high-temperature glow peak (614 K) intensity linearly increases with an increase in ion fluence. The broad TL glow curves were deconvoluted using the glow curve deconvoluted method and kinetic parameters were calculated using the general order kinetic equation.

  2. Colloidal assemblies modified by ion irradiation

    NARCIS (Netherlands)

    Snoeks, E.; Blaaderen, A. van; Dillen, T. van; Kats, C.M. van; Velikov, K.P.; Brongersma, M.L.; Polman, A.

    2001-01-01

    Spherical SiO2 and ZnS colloidal particles show a dramatic anisotropic plastic deformation under 4 MeV Xe ion irradiation, that changes their shape into oblate into oblate ellipsional, with an aspect ratio that can be precisely controlled by the ion fluence. The 290 nm and 1.1 um diameter colloids

  3. Colloidal assemblies modified by ion irradiation

    OpenAIRE

    Snoeks, E.; Blaaderen, A. van; Dillen, T. van; Kats, C.M. van; Velikov, K.P.; Brongersma, M.L.; Polman, A.

    2001-01-01

    Spherical SiO2 and ZnS colloidal particles show a dramatic anisotropic plastic deformation under 4 MeV Xe ion irradiation, that changes their shape into oblate into oblate ellipsional, with an aspect ratio that can be precisely controlled by the ion fluence. The 290 nm and 1.1 um diameter colloids were deposited on a Si substrate and irradiated at 90 K, using fluences in the range 3*10^(13)-8*10^(14) cm^(-2). The transverse particle diameter shows a linear increase with ion fluence, while the...

  4. Softening of metals under hydrogen ion irradiation

    International Nuclear Information System (INIS)

    Guseva, M.I.; Korshunov, S.N.; Martynenko, Yu.V.; Skorlupkin, I.D.

    2005-01-01

    Experimental study results are presented on steel type 18-10 creep under hydrogen ion irradiation. The Irradiation of annealed specimens is accomplished by 15 keV H 2 + ions with a dose up to 10 22 m -2 at current density of 0.6 A/m 2 at temperatures of 570-770 K. Creep tests show that the irradiation at T = 770 K results in a sharp increase of creep rate. At t 570 K the effect of ion-induced creep in steel 18-10 is not observed. The model is proposed which explains the ion-induced creep by accumulation of hydrogen along grain boundaries, their weakening and removal of obstacles to sliding [ru

  5. Heavy Ion Irradiation Effects in Zirconium Nitride

    International Nuclear Information System (INIS)

    Egeland, G.W.; Bond, G.M.; Valdez, J.A.; Swadener, J.G.; McClellan, K.J.; Maloy, S.A.; Sickafus, K.E.; Oliver, B.

    2004-01-01

    Polycrystalline zirconium nitride (ZrN) samples were irradiated with He + , Kr ++ , and Xe ++ ions to high (>1.10 16 ions/cm 2 ) fluences at ∼100 K. Following ion irradiation, transmission electron microscopy (TEM) and grazing incidence X-ray diffraction (GIXRD) were used to analyze the microstructure and crystal structure of the post-irradiated material. For ion doses equivalent to approximately 200 displacements per atom (dpa), ZrN was found to resist any amorphization transformation, based on TEM observations. At very high displacement damage doses, GIXRD measurements revealed tetragonal splitting of some of the diffraction maxima (maxima which are associated with cubic ZrN prior to irradiation). In addition to TEM and GIXRD, mechanical property changes were characterized using nano-indentation. Nano-indentation revealed no change in elastic modulus of ZrN with increasing ion dose, while the hardness of the irradiated ZrN was found to increase significantly with ion dose. Finally, He + ion implanted ZrN samples were annealed to examine He gas retention properties of ZrN as a function of annealing temperature. He gas release was measured using a residual gas analysis (RGA) spectrometer. RGA measurements were performed on He-implanted ZrN samples and on ZrN samples that had also been irradiated with Xe ++ ions, in order to introduce high levels of displacive radiation damage into the matrix. He evolution studies revealed that ZrN samples with high levels of displacement damage due to Xe implantation, show a lower temperature threshold for He release than do pristine ZrN samples. (authors)

  6. Physico-chemical transformations in swift heavy ion modified poly(ethyleneterephthalate)

    Science.gov (United States)

    Aggarwal, Prerna; Singh, Virendra; Singh, Arjun; Scherer, U. W.; Singh, Tejvir; Singla, Madan L.; Srivastava, Alok

    2012-03-01

    Thin films of poly(ethyleneterephthalate) (PET) were exposed to different radiation dose brought about by 80 MeV carbon and 98 MeV silicon ion beam. The UV-vis absorption studies reveal that there is decrease in optical band gap energy to the extent of ˜29.3 and 42.1%. The X-ray diffraction analyses have shown that crystallite size decreased by ˜18.6 and 52.6%, indicating amorphization of PET. The colour of PET films change from colourless to light yellowish followed by light brown as radiation dose is increased. The colour formation has been ascribed to an increase in conjugation in the carbon chain. In the case of PET irradiated with carbon ion, the electrical conductivity increased with frequency beyond a threshold value of 1 kHz. The increase in conductivity of PET films on irradiation is due to formation of defects and carbon clusters as a result of polymer chain scission. The thermal study further confirmed the increase in amorphous nature with increase in radiation dose. The results indicate that radiation dose brings about significant physicochemical transformations in PET.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Physico-chemical transformations in swift heavy ion modified poly(ethyleneterephthalate)

    International Nuclear Information System (INIS)

    Aggarwal, Prerna; Singh, Virendra; Singh, Arjun; Scherer, U.W.; Singh, Tejvir; Singla, Madan L.; Srivastava, Alok

    2012-01-01

    Thin films of poly(ethyleneterephthalate) (PET) were exposed to different radiation dose brought about by 80 MeV carbon and 98 MeV silicon ion beam. The UV–vis absorption studies reveal that there is decrease in optical band gap energy to the extent of ∼29.3 and 42.1%. The X-ray diffraction analyses have shown that crystallite size decreased by ∼18.6 and 52.6%, indicating amorphization of PET. The colour of PET films change from colourless to light yellowish followed by light brown as radiation dose is increased. The colour formation has been ascribed to an increase in conjugation in the carbon chain. In the case of PET irradiated with carbon ion, the electrical conductivity increased with frequency beyond a threshold value of 1 kHz. The increase in conductivity of PET films on irradiation is due to formation of defects and carbon clusters as a result of polymer chain scission. The thermal study further confirmed the increase in amorphous nature with increase in radiation dose. The results indicate that radiation dose brings about significant physicochemical transformations in PET. - Highlights: ► Thin films of poly(ethyleneterephthalate) exposed to 80 MeV carbon and 98 MeV Silicon ion. ► UV–vis absorption studies reveal decrease of optical energy gap up to ∼29.3 and 42.1%. ► XRD shows 18.6 and 52.6% decrease in crystallite size indicating amorphization of PET film. ► Conductivity measurement with frequency shows a parabolic increase beyond 1 kHz. ► Thermal study confirmed increased amorphous nature of material with radiation dose.

  9. Heavy ion irradiation of astrophysical ice analogs

    International Nuclear Information System (INIS)

    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)

  10. Radiolysis and sputtering of carbon dioxide ice induced by swift Ti, Ni, and Xe ions

    Energy Technology Data Exchange (ETDEWEB)

    Mejía, C. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, 22453-900 Rio de Janeiro, RJ (Brazil); Bender, M.; Severin, D. [Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Trautmann, C. [Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technische Universität, 64287 Darmstadt (Germany); Boduch, Ph. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Bordalo, V. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Observatório Nacional-MCTI, Rua General José Cristino 77, 20921-400 Rio de Janeiro, RJ (Brazil); Domaracka, A.; Lv, X.Y. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); and others

    2015-12-15

    Solid carbon dioxide (CO{sub 2}) is found in several bodies of the solar system, the interstellar medium (ISM) and young stellar objects, where it is exposed to cosmic and stellar wind radiation. Here, the chemical and physical modifications induced by heavy ion irradiation of pure solid CO{sub 2} at low temperature (T = 15–30 K) are analyzed. The experiments were performed with Ti (550 MeV) and Xe (630 MeV) ions at the UNILAC of GSI/Darmstadt and with Ni ions (46 and 52 MeV) at IRRSUD of GANIL/Caen. The evolution of the thin CO{sub 2} ice films (deposited on a CsI window) was monitored by mid-infrared absorption spectroscopy (FTIR). The dissociation rate of CO{sub 2}, determined from the fluence dependence of the IR absorption peak intensity, is found to be proportional to the electronic stopping power S{sub e}. We also confirm that the sputtering yield shows a quadric increase with electronic stopping power. Furthermore, the production rates of daughter molecules such as CO, CO{sub 3} and O{sub 3} were found to be linear in S{sub e}.

  11. Novel optical waveguides by in-depth controlled electronic damage with swift ions

    Science.gov (United States)

    Olivares, J.; García-Navarro, A.; Méndez, A.; Agulló-López, F.; García, G.; García-Cabañes, A.; Carrascosa, M.

    2007-04-01

    We review recent results on a novel method to modify crystalline dielectric materials and fabricate optical waveguides and integrated optics devices. It relies on irradiation with medium-mass high-energy ions (2-50 MeV) where the electronic stopping power is dominant over that one associated to nuclear collisions. By exploiting the processing capabilities of the method, novel optical structures can be achieved at moderate (1014 cm-2) and even low and ultralow (1012 cm-2) fluences. In particular, step-like waveguides with a high index jump Δn ∼ 0.1-0.2, guiding both ordinary and extraordinary modes, have been prepared with F and O ions (20 MeV) at moderate fluences. They present good non-linear and electrooptic perfomance and low losses. (1 dB/cm). Moreover, useful optical waveguiding has been also achieved at ultralow frequencies (isolated track regime), using Cl and Si ions (40-45 MeV). In this latter case, the individual amorphous nanotracks, whose radius increases with depth, create an effective optical medium causing optical trapping.

  12. Novel optical waveguides by in-depth controlled electronic damage with swift ions

    International Nuclear Information System (INIS)

    Olivares, J.; Garcia-Navarro, A.; Mendez, A.; Agullo-Lopez, F.; Garcia, G.; Garcia-Cabanes, A.; Carrascosa, M.

    2007-01-01

    We review recent results on a novel method to modify crystalline dielectric materials and fabricate optical waveguides and integrated optics devices. It relies on irradiation with medium-mass high-energy ions (2-50 MeV) where the electronic stopping power is dominant over that one associated to nuclear collisions. By exploiting the processing capabilities of the method, novel optical structures can be achieved at moderate (10 14 cm -2 ) and even low and ultralow (10 12 cm -2 ) fluences. In particular, step-like waveguides with a high index jump Δn ∼ 0.1-0.2, guiding both ordinary and extraordinary modes, have been prepared with F and O ions (20 MeV) at moderate fluences. They present good non-linear and electrooptic perfomance and low losses. (1 dB/cm). Moreover, useful optical waveguiding has been also achieved at ultralow frequencies (isolated track regime), using Cl and Si ions (40-45 MeV). In this latter case, the individual amorphous nanotracks, whose radius increases with depth, create an effective optical medium causing optical trapping

  13. Thermo-luminescence and photoluminescence studies of Al2O3 irradiated with heavy ions

    International Nuclear Information System (INIS)

    Jheeta, K.S.

    2008-06-01

    Thermo-luminescence (TL) spectra of single crystals of Al 2 O 3 (sapphire) irradiated with 200 MeV swift Ag ions at different fluence in the range 1x10 11 to 1x10 13 ions/cm 2 has been recorded at room temperature by keeping the warming rate 2K/min. The TL glow curve of the irradiated samples has a simple structure with a prominent peak at ∼ 500 K with one small peak at 650 K. The intensity of main peak increases with the ion fluence. This has been attributed to the creation of new traps on irradiation. Also, a shift of 8 K in the peak position towards low temperature side has been observed at higher fluence 1x10 13 ions/cm 2 . In addition, photoluminescence (PL) spectra of irradiated samples have been recorded at room temperature upon 2.8 eV excitation. A broad band consisting of mainly two emission bands, respectively at 2.5 and 2.3 eV corresponding to F 2 and F 2 2+ defect centers is observed. The intensity of these bands shows an increasing trend up to fluence 5x10 12 ions/cm 2 and then decreases at higher fluence 1x10 13 ions/cm 2 . The results are interpreted in terms of creation of newly defect centers, clustering/aggregation and radiation-induced annihilation of defects. (author)

  14. Ion irradiation studies of oxide ceramics

    International Nuclear Information System (INIS)

    Zinkle, S.J.

    1988-01-01

    This paper presents the initial results of an investigation of the depth-dependent microstructures of three oxide ceramics following ion implantation to moderate doses. The implantations were performed using ion species that occur as cations in the target material; for example, Mg + ions were used for MgO and MgAl 2 O 4 (spinel) irradiations. This minimized chemical effects associated with the implantation and allowed a more direct evaluation to be made of the effects of implanted ions on the microstructure. 11 refs., 14 figs

  15. Effects of ion beam irradiation on semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Nashiyama, Isamu; Hirao, Toshio; Itoh, Hisayoshi; Ohshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Energetic heavy-ion irradiation apparatus has been developed for single-event effects (SEE) testing. We have applied three irradiation methods such as a scattered-ion irradiation method, a recoiled-atom irradiation method, and a direct-beam irradiation method to perform SEE testing efficiently. (author)

  16. Swift cookbook

    CERN Document Server

    Costa, Cecil

    2015-01-01

    If you are an experienced Objective-C programmer and are looking for quick solutions to many different coding tasks in Swift, then this book is for you. You are expected to have development experience, though not necessarily with Swift.

  17. Compositional, structural and optical changes of polyimide irradiated by heavy ions

    Czech Academy of Sciences Publication Activity Database

    Mikšová, Romana; Macková, Anna; Cutroneo, Mariapompea; Slepička, P.; Matoušek, J.

    2016-01-01

    Roč. 48, č. 7 (2016), s. 566-569 ISSN 0142-2421. [16th European Conference on Applications of Surface and Interface Analysis (ECASIA). Granada, 28.09.2015-01.10.2015] R&D Projects: GA MŠk(CZ) LM2011019; GA ČR GA15-01602S Institutional support: RVO:61389005 Keywords : polyimide * polymer degradation * swift heavy-ion irradiation * surface morphology Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.132, year: 2016

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

    International Nuclear Information System (INIS)

    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

  19. Color center annealing and ageing in electron and ion-irradiated yttria-stabilized zirconia

    International Nuclear Information System (INIS)

    Costantini, Jean-Marc; Beuneu, Francois

    2005-01-01

    We have used X-band electron paramagnetic resonance (EPR) measurements at room-temperature (RT) to study the thermal annealing and RT ageing of color centers induced in yttria-stabilized zirconia (YSZ), i.e. ZrO 2 :Y with 9.5 mol% Y 2 O 3 , by swift electron and ion-irradiations. YSZ single crystals with the orientation were irradiated with 2.5 MeV electrons, and implanted with 100 MeV 13 C ions. Electron and ion beams produce the same two color centers, namely an F + -type center (singly ionized oxygen vacancy) and the so-called T-center (Zr 3+ in a trigonal oxygen local environment) which is also produced by X-ray irradiations. Isochronal annealing was performed in air up to 973 K. For both electron and ion irradiations, the defect densities are plotted versus temperature or time at various fluences. The influence of a thermal treatment at 1373 K of the YSZ single crystals under vacuum prior to the irradiations was also investigated. In these reduced samples, color centers are found to be more stable than in as-received samples. Two kinds of recovery processes are observed depending on fluence and heat treatment

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

    Science.gov (United States)

    Fink, Dietmar; Vacik, Jiri; Hnatowicz, V.; Muñoz Hernandez, G.; Garcia Arrelano, H.; Alfonta, Lital; Kiv, Arik

    2017-05-01

    For understanding of the diffusion kinetics and their optimization in swift heavy ion track-based biosensors, recently a diffusion simulation was performed. This simulation aimed at yielding the degree of enrichment of the enzymatic reaction products in the highly confined space of the etched ion tracks. A bunch of curves was obtained for the description of such sensors that depend only on the ratio of the diffusion coefficient of the products to that of the analyte within the tracks. As hitherto none of these two diffusion coefficients is accurately known, the present work was undertaken. The results of this paper allow one to quantify the previous simulation and hence yield realistic predictions of glucose-based biosensors. At this occasion, also the influence of the etched track radius on the diffusion coefficients was measured and compared with earlier prediction.

  1. GXRD study of 100 MeV Fe9+ ion irradiated indium phosphide

    International Nuclear Information System (INIS)

    Dubey, R.L.; Dubey, S.K.; Kachhap, N.K.; Kanjilal, D.

    2014-01-01

    Swift heavy ions with MeV to GeV kinetic energy offer unique possibilities of modifying material properties. Each projectile passing through the target material causes loss of its energy by ion-electrons and ion-atoms interaction with the target material. The consequence of formal one is to change in surface properties and latter to produces damage deep in the target material near the projected range of projectile. In the present work, indium phosphide samples were irradiated at 100 MeV 56 Fe 9+ ions with different fluences varying from 1x10 12 to 1x10 14 ions cm -2 using the 15UD Pelletron facilities at Inter University Accelerator Centre (IUAC), New Delhi. Grazing angle X-ray diffraction technique was used to investigate the structural properties of irradiated indium phosphide at different depths. The GXRD spectra of non-irradiated and irradiated samples were recorded at different grazing angle i.e 1°, 2°, 3°, 4° and 5° to get the structural information over the projected range. The detailed result will be presented and discussed in the conference. (author)

  2. Effect of triple ion beam irradiation on mechanical properties of high chromium austenitic stainless steel

    International Nuclear Information System (INIS)

    Ioka, Ikuo; Futakawa, Masatoshi; Nanjyo, Yoshiyasu; Kiuchi, Kiyoshi; Anegawa, Takefumi

    2003-01-01

    A high-chromium austenitic stainless steel has been developed for an advanced fuel cladding tube considering waterside corrosion and irradiation embrittlement. The candidate material was irradiated in triple ion (Ni, He, H) beam modes at 573 K up to 50 dpa to simulate irradiation damage by neutron and transmutation product. The change in hardness of the very shallow surface layer of the irradiated specimen was estimated from the slope of load/depth-depth curve which is in direct proportion to the apparent hardness of the specimen. Besides, the Swift's power low constitutive equation (σ=A(ε 0 + ε) n , A: strength coefficient, ε 0 : equivalent strain by cold rolling, n: strain hardening exponent) of the damaged parts was derived from the indentation test combined with an inverse analysis using a finite element method (FEM). For comparison, Type304 stainless steel was investigated as well. Though both Type304SS and candidate material were also hardened by ion irradiation, the increase in apparent hardness of the candidate material was smaller than that of Type304SS. The yield stress and uniform elongation were estimated from the calculated constitutive equation by FEM inverse analysis. The irradiation hardening of the candidate material by irradiation can be expected to be lower than that of Type304SS. (author)

  3. A model of chemical etching of olivine in the vicinity of the trajectory of a swift heavy ion

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunov, S.A., E-mail: s.a.gorbunov@mail.ru [Lebedev Physical Institute of the Russian Academy of Sciences, Leninskij pr. 53, 119991 Moscow (Russian Federation); Rymzhanov, R.A. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Starkov, N.I. [Lebedev Physical Institute of the Russian Academy of Sciences, Leninskij pr. 53, 119991 Moscow (Russian Federation); Volkov, A.E. [Lebedev Physical Institute of the Russian Academy of Sciences, Leninskij pr. 53, 119991 Moscow (Russian Federation); Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); National Research Centre ‘Kurchatov Institute’, Kurchatov Sq. 1, 123182 Moscow (Russian Federation); Malakhov, A.I. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation)

    2015-12-15

    Searching of superheavy elements, the charge spectra of heavy nuclei in Galactic Cosmic Rays was investigated within the OLYMPIA experiment using the database of etched ion tracks in meteorite olivine. Etching results in the formation of hollow syringe-like channels with diameters of 1–10 μm along the trajectories of these swift heavy ions (SHI). According to the activated complex theory, the local chemical activity is determined by an increase of the specific Gibbs energy of the lattice stimulated by structure transformations, long-range elastic fields, and interatomic bonds breaking generated in the vicinity of the ion trajectory. To determine the dependencies of the Gibbs free energy increase in SHI tracks in olivine on the mass, energy and charge of a projectile, we apply a multiscale model of excitation and relaxation of materials in the vicinity of the SHI trajectory (SHI tracks). Effect of spreading of fast electrons from the ion trajectory causing neutralization of metallic atoms resulting in an increase of the chemical activity of olivine at long distances from the ion trajectory (up to 5 μm) is estimated and discussed.

  4. Nitridation of vanadium by ion beam irradiation

    International Nuclear Information System (INIS)

    Kiuchi, Masato; Chayahara, Akiyoshi; Kinomura, Atsushi; Ensinger, Wolfgang

    1994-01-01

    The nitridation of vanadium by ion beam irradiation is studied by the ion implantation method and the dynamic mixing method. The nitrogen ion implantation was carried out into deposited V(110) films. Using both methods, three phases are formed, i.e. α-V, β-V 2 N, and δ-VN. Which phases are formed is related to the implantation dose or the arrival ratio. The orientation of the VN films produced by the dynamic ion beam mixing method is (100) and that of the VN films produced by the ion implantation method is (111). The nitridation of vanadium is also discussed in comparison with that of titanium and chromium. ((orig.))

  5. Genetic effects of heavy ion irradiation in maize and soybean

    International Nuclear Information System (INIS)

    Yatou, Osamu; Amano, Etsuo; Takahashi, Tan.

    1992-01-01

    Somatic mutation on leaves of maize and soybean were observed to investigate genetic effects of heavy ion irradiation. Maize seeds were irradiated with N, Fe and U ions and soybean seeds were irradiated with N ions. This is a preliminary report of the experiment, 1) to examine the mutagenic effects of the heavy ion irradiation, and 2) to evaluate the genetic effects of cosmic ray exposure in a space ship outside the earth. (author)

  6. Ions irradiation on bi-layer coatings

    Science.gov (United States)

    Tessarolo, Enrico; Corso, Alain Jody; Böttger, Roman; Martucci, Alessandro; Pelizzo, Maria G.

    2017-09-01

    Future space missions will operate in very harsh and extreme environments. Optical and electronics components need to be optimized and qualified in view of such operational challenges. This work focuses on the effect of low alpha particles irradiation on coatings. Low energy He+ (4 keV and 16 keV) ions have been considered in order to simulate in laboratory the irradiation of solar wind (slow and fast components) alpha particles. Mono- and proper bi-layers coatings have been investigated. The experimental tests have been carried out changing doses as well as fluxes during the irradiation sessions. Optical characterization in the UV-VIS spectral range and superficial morphological analysis have performed prior and after irradiation.

  7. Heavy ions amorphous semiconductors irradiation study

    International Nuclear Information System (INIS)

    Benmalek, M.

    1978-01-01

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

  8. Ion beam techniques for analyzing polymers irradiated by ions

    International Nuclear Information System (INIS)

    Rickards, J.; Zironi, E.P.; Andrade, E.; Dominguez, B.

    1992-01-01

    In the study of the effects of ion beam irradiation of polymers very large doses can be administered in short times. Thousands of MGy can be produced in a small volume of a sample in a few minutes by bombarding with typical ion beam currents. For instance, in an experiment done to observe the effects of 750 keV proton irradiation PVC, using a collimator of 1 mm diameter, 1 μC of charge integration deposits a dose of 50 MGy. The use of ion beams also opens up the possibility of using the same beam for irradiation and for analysis of the effects, using the well known ion beam analysis techniques. PIXE allows the measurement of chlorine in PVC. Polymers containing fluorine can be measured with the resonant nuclear reaction (RNR) technique, which is specific only to certain elements. The amount of hydrogen in the sample and its profile can be obtained using energy recoil detection analysis (ERDA); carbon, oxygen, and nitrogen can be measured and profiled using Rutherford backscattering (RBS) and also using the (d,p) and (d, α) nuclear reactions (NR). Loss of mass is one effect that can be studied using these techniques. It was studied in two different polymers, PVC and CR-39, in order to determine carbon buildup during ion irradiation. It was concluded that carbon builds up following different mechanisms in these two materials, due to the different possibilities of forming volatile compounds. It is also suggested that CR-39 should be a good material for ion beam lithography. (author)

  9. Forging Fast Ion Conducting Nanochannels with Swift Heavy Ions: The Correlated Role of Local Electronic and Atomic Structure

    Energy Technology Data Exchange (ETDEWEB)

    Sachan, Ritesh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Cooper, Valentino R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Liu, Bin [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Aidhy, Dilpuneet S. [Univ. of Wyoming, Laramie, WY (United States). Dept. of Mechanical Engineering; Voas, Brian K. [Iowa State Univ., Ames, IA (United States). Dept. of Materials Science and Engineering; Lang, Maik [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Nuclear Engineering; Ou, Xin [Chinese Academy of Sciences (CAS), Shanghai (China). State Key Lab. of Functional Material for Informatics; Trautmann, Christina [GSI Helmholtz Centre for Heavy Ion Research, Darmstadt (Germany); Technical Univ. of Darmstadt (Germany). Dept. of Materials Science; Zhang, Yanwen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Chisholm, Matthew F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Weber, William J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division

    2016-12-19

    Atomically disordered oxides have attracted significant attention in recent years due to the possibility of enhanced ionic conductivity. However, the correlation between atomic disorder, corresponding electronic structure, and the resulting oxygen diffusivity is not well understood. The disordered variants of the ordered pyrochlore structure in gadolinium titanate (Gd2Ti2O7) are seen as a particularly interesting prospect due to intrinsic presence of a vacant oxygen site in the unit atomic structure, which could provide a channel for fast oxygen conduction. In this paper, we provide insights into the subangstrom scale on the disordering-induced variations in the local atomic environment and its effect on the electronic structure in high-energy ion irradiation-induced disordered nanochannels, which can be utilized as pathways for fast oxygen ion transport. With the help of an atomic plane-by-plane-resolved analyses, the work shows how the presence of various types of TiOx polyhedral that exist in the amorphous and disordered crystalline phase modify the electronic structures relative to the ordered pyrochlore phase in Gd2Ti2O7. Finally, the correlated molecular dynamics simulations on the disordered structures show a remarkable enhancement in oxygen diffusivity as compared with ordered pyrochlore lattice and make that a suitable candidate for applications requiring fast oxygen conduction.

  10. Selective binding of oligonucleotide on TiO2 surfaces modified by swift heavy ion beam lithography

    International Nuclear Information System (INIS)

    Vicente Pérez-Girón, J.; Hirtz, M.; McAtamney, C.; Bell, A.P.; Antonio Mas, J.; Jaafar, M.; Luis, O. de; Fuchs, H.

    2014-01-01

    We have used swift heavy-ion beam based lithography to create patterned bio-functional surfaces on rutile TiO 2 single crystals. The applied lithography method generates a permanent and well defined periodic structure of micrometre sized square holes having nanostructured TiO 2 surfaces, presenting different physical and chemical properties compared to the surrounding rutile single crystal surface. On the patterned substrates selective binding of oligonucleotides molecules is possible at the surfaces of the holes. This immobilisation process is only being controlled by UV light exposure. The patterned transparent substrates are compatible with fluorescence detection techniques, are mechanically robust, have a high tolerance to extreme chemical and temperature environments, and apparently do not degrade after ten cycles of use. These qualities make the patterned TiO 2 substrates useful for potential biosensor applications

  11. Selective binding of oligonucleotide on TiO{sub 2} surfaces modified by swift heavy ion beam lithography

    Energy Technology Data Exchange (ETDEWEB)

    Vicente Pérez-Girón, J. [Nanoate, S.L. C/Poeta Rafael Morales 2, San Sebastian de los Reyes, 28702 Madrid (Spain); Emerging Viruses Department Heinrich Pette Institute, Hamburg 20251 (Germany); Hirtz, M. [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); McAtamney, C.; Bell, A.P. [Advanced Microscopy Laboratory, CRANN, Trinity College Dublin, Dublin 2 (Ireland); Antonio Mas, J. [Laboratorio de Genómica del Centro de Apoyo Tecnológico, Universidad Rey Juan Carlos, Campus de Alcorcón 28922, Madrid (Spain); Jaafar, M. [Nanoate, S.L. C/Poeta Rafael Morales 2, San Sebastian de los Reyes, 28702 Madrid (Spain); Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Luis, O. de [Nanoate, S.L. C/Poeta Rafael Morales 2, San Sebastian de los Reyes, 28702 Madrid (Spain); Departamento de Bioquímica, Fisiología y Genética Molecular, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Campus de Alcorcón, 28922 Madrid (Spain); Fuchs, H. [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Physical Institute and Center for Nanotechnology (CeNTech), Wilhelm-Klemm-Straße 10, University of Münster (Germany); and others

    2014-11-15

    We have used swift heavy-ion beam based lithography to create patterned bio-functional surfaces on rutile TiO{sub 2} single crystals. The applied lithography method generates a permanent and well defined periodic structure of micrometre sized square holes having nanostructured TiO{sub 2} surfaces, presenting different physical and chemical properties compared to the surrounding rutile single crystal surface. On the patterned substrates selective binding of oligonucleotides molecules is possible at the surfaces of the holes. This immobilisation process is only being controlled by UV light exposure. The patterned transparent substrates are compatible with fluorescence detection techniques, are mechanically robust, have a high tolerance to extreme chemical and temperature environments, and apparently do not degrade after ten cycles of use. These qualities make the patterned TiO{sub 2} substrates useful for potential biosensor applications.

  12. The thermal-spike model description of the ion-irradiated polyimide

    International Nuclear Information System (INIS)

    Sun Youmei; Zhang Chonghong; Zhu Zhiyong; Wang Zhiguang; Jin Yunfan; Liu Jie; Wang Ying

    2004-01-01

    To describe the role of electronic energy loss (dE/dX) e for chemical modification of polyimide (PI), multi-layer stacks (corresponding to different dE/dX) were irradiated by different swift heavy ions (1.158 GeV Fe 56 and 1.755 GeV Xe 136 ) under vacuum and at room temperature. Chemical changes of modified PI films were studied by Fourier transform infrared (FTIR) spectroscopy. The chain disruption rate of PI was investigated in the fluence range from 1 x 10 11 to 6 x 10 12 ions/cm 2 and a wider energy stopping power range (2.2-5.1 keV/nm for Fe 56 ions and 8.6-11.5 keV/nm for Xe 136 ions). Alkyne formation was observed over the electronic energy loss range of interest. By applying the saturated track model assumption (the damage process only occur in a cylinder of area σ), the mean degradation and alkyne formation radii in tracks were induced for Fe and Xe ion irradiation, respectively. The results were validated by the thermal-spike model. The analysis of the irradiated PI films shows that the predictions of the thermal-spike model of Szenes are in qualitative agreement with the curve shape of experimental results

  13. A thermal spike model of the amorphization of insulators by high-energy heavy-ion irradiation

    International Nuclear Information System (INIS)

    Szenes, G.

    1995-01-01

    Recently, experimental data on magnetic insulators irradiated with swift heavy ions were analyzed by a new thermal spike model and good quantitative agreement was achieved. Analytical expressions were given for the evolution of latent tracks with the electronic stopping power S e of bombarding ions and a relation between the thermal properties of the target and the threshold value of S e was proposed and proved experimentally. In the present paper, after a brief review of the model, the temperature dependence of latent track formation is discussed and the predictions of the model are compared with the available experimental results

  14. Anisotropic dewetting of ion irradiated solid films

    Energy Technology Data Exchange (ETDEWEB)

    Repetto, L., E-mail: luca.repetto@unige.it [Dipartimento di fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Šetina Batič, B. [Inštitut Za Kovinske Materiale in Tehnologije, Lepi pot 11, 1000 Ljubljana (Slovenia); Firpo, G.; Piano, E.; Valbusa, U. [Dipartimento di fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova (Italy)

    2013-11-15

    Experiments of irradiation with 30 keV Ga ions were conducted on ultrathin chromium films on rippled silicon substrates. The evolution of their surface morphology, as detected by real time scanning electron microscopy, shows an apparent differential sputtering yield for regions of positive and negative curvature which is in contrast with the standard theory for curvature depending sputtering yield. In particular, at the end of the irradiation process, chromium wires are left in the valleys of the substrate. This result was explained in terms of local melting caused by the ion impact and of a process of dewetting under the concurring actions of surface tension and Van der Waals forces while ion sputtering is active. The interpretation of the reported experimental results are fully supported by numeric simulations implementing the same continuum model used to explain ion induced spinodal dewetting. This hierarchical self-organization process breaks the symmetry of previously demonstrated ion induced dewetting, making possible to create new structures by using the same fundamental effects.

  15. Effect of irradiation spectrum on the microstructure of ion-irradiated Al2O3

    International Nuclear Information System (INIS)

    Zinkle, S.J.

    1994-01-01

    Polycrystalline samples of alpha-alumina have been irradiated with various ions ranging from 3.6 MeV Fe + to 1 MeV H + ions at 650 C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructure of the irradiated specimens. The microstructure following irradiation was observed to be dependent on the irradiation spectrum. In particular, defect cluster nucleation was effectively suppressed in specimens irradiated with light ions such as 1 MeV H + ions. On the other hand, light ion irradiation tended to accelerate the growth rate of dislocation loops. The microstructural observations are discussed in terms of ionization enhanced diffusion processes

  16. Physico-chemical characterization of polyethylene of ultra high molecular weight modified with gamma irradiation and heavy ions

    International Nuclear Information System (INIS)

    Lagarde, M; Del Grosso, M; Fasce, D; Dommarco, R; Laino, S; Fasce, L.A

    2012-01-01

    The ultra high molecular weight polyethylene (UHMWPE) is a biomaterial widely used in total joint replacement. In this work, the effect of two different irradiation techniques on UHMWPE is analyzed. One technique involves gamma irradiation (γ) followed by a thermal treatment, thus modifying the material bulk. The other implies swift heavy ion irradiation (SHI), which have an effect only on the near surface layers. The surface nanomechanical properties are evaluated from depth sensing indentation experiments, while changes in crystallinity and chemical structure are determined by DSC and Raman spectroscopy. The results show that even when both techniques are able to improve the UHMWPE wear behavior, the effect on other mechanical properties and molecular structure modification is different. The γ irradiated sample exhibits lower crystallinity, hardness and modulus than the pristine UHMWPE, while the SHI irradiated sample exhibits higher crystallinity and enhanced mechanical properties than the later

  17. Mutation induced with ion beam irradiation in rose

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H. E-mail: yhiroya@nias.affrc.go.jp; Nagatomi, S.; Morishita, T.; Degi, K.; Tanaka, A.; Shikazono, N.; Hase, Y

    2003-05-01

    The effects of mutation induction by ion beam irradiation on axillary buds in rose were investigated. Axillary buds were irradiated with carbon and helium ion beams, and the solid mutants emerged after irradiation by repeated cutting back. In helium ion irradiation, mutations were observed in plants derived from 9 buds among 56 irradiated buds in 'Orange Rosamini' and in plants derived from 10 buds among 61 irradiated buds in 'Red Minimo'. In carbon ion, mutations were observed in plants derived from 12 buds among 88 irradiated buds in 'Orange Rosamini'. Mutations were induced not only in higher doses but also in lower doses, with which physiological effect by irradiation was hardly observed. Irradiation with both ion beams induced mutants in the number of petals, in flower size, in flower shape and in flower color in each cultivar.

  18. Scanning ion irradiation of polyimide films

    Energy Technology Data Exchange (ETDEWEB)

    Luecken, Stefan; Koval, Yuri; Mueller, Paul [Department of Physics and Interdisciplinary Center for Molecular Materials (ICMM), Universitaet Erlangen-Nuernberg (Germany)

    2012-07-01

    Recently we found, that the surface of nearly any polymer can be converted into conductive material by low energy ion irradiation. The graphitized layer consists of nanometer sized graphene and graphite flakes. In order to enhance the conductivity and to increase the size of the flakes we applied a novel method of scanning irradiation. We investigated the influence of various irradiation parameters on the conductivity of the graphitized layer. We show, that the conductance vs. temperature can be described in terms of weak Anderson localization. At approximately 70 K, a crossover occurs from 2-dimensional to 3-dimensional behavior. This can be explained by a decrease of the Thouless length with increasing temperature. The crossover temperature can be used to estimate the thickness of the graphitized layer.

  19. Nanoscale Morphology Evolution Under Ion Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Michael J. [President & Fellows of Harvard College, Cambridge, MA (United States)

    2014-11-10

    We showed that the half-century-old paradigm of morphological instability under irradiation due to the curvature-dependence of the sputter yield, can account neither for the phase diagram nor the amplification or decay rates that we measure in the simplest possible experimental system -- an elemental semiconductor with an amorphous surface under noble-gas ion irradiation; We showed that a model of pattern formation based on the impact-induced redistribution of atoms that do not get sputtered away explains our experimental observations; We developed a first-principles, parameter-free approach for predicting morphology evolution, starting with molecular dynamics simulations of single ion impacts, lasting picoseconds, and upscaling through a rigorous crater-function formalism to develop a partial differential equation that predicts morphology evolution on time scales more than twelve orders of magnitude longer than can be covered by the molecular dynamics; We performed the first quantitative comparison of the contributions to morphological instability from sputter removal and from impact-induced redistribution of atoms that are removed, and showed that the former is negligible compared to the latter; We established a new paradigm for impact-induced morphology evolution based on crater functions that incorporate both redistribution and sputter effects; and We developed a model of nanopore closure by irradiation-induced stress and irradiationenhanced fluidity, for the near-surface irradiation regime in which nuclear stopping predominates, and showed that it explains many aspects of pore closure kinetics that we measure experimentally.

  20. Surface functionalization of epitaxial graphene on SiC by ion irradiation for gas sensing application

    International Nuclear Information System (INIS)

    Kaushik, Priya Darshni; Ivanov, Ivan G.; Lin, Pin-Cheng; Kaur, Gurpreet; Eriksson, Jens; Lakshmi, G.B.V.S.; Avasthi, D.K.; Gupta, Vinay; Aziz, Anver; Siddiqui, Azher M.; Syväjärvi, Mikael; Yazdi, G. Reza

    2017-01-01

    Highlights: • For the first time the gas sensing application of SHI irradiated epitaxial graphene on SiC is explored. • Surface morphology of irradiated graphene layers showed graphene folding, hillocks, and formation of wrinkles. • Existence of an optimal fluence which maximize the gas sensing response towards NO_2 and NH_3 gases. - Abstract: In this work, surface functionalization of epitaxial graphene grown on silicon carbide was performed by ion irradiation to investigate their gas sensing capabilities. Swift heavy ion irradiation using 100 MeV silver ions at four varying fluences was implemented on epitaxial graphene to investigate morphological and structural changes and their effects on the gas sensing capabilities of graphene. Sensing devices are expected as one of the first electronic applications using graphene and most of them use functionalized surfaces to tailor a certain function. In our case, we have studied irradiation as a tool to achieve functionalization. Morphological and structural changes on epitaxial graphene layers were investigated by atomic force microscopy, Raman spectroscopy, Raman mapping and reflectance mapping. The surface morphology of irradiated graphene layers showed graphene folding, hillocks, and formation of wrinkles at highest fluence (2 × 10"1"3 ions/cm"2). Raman spectra analysis shows that the graphene defect density is increased with increasing fluence, while Raman mapping and reflectance mapping show that there is also a reduction of monolayer graphene coverage. The samples were investigated for ammonia and nitrogen dioxide gas sensing applications. Sensors fabricated on pristine and irradiated samples showed highest gas sensing response at an optimal fluence. Our work provides new pathways for introducing defects in controlled manner in epitaxial graphene, which can be used not only for gas sensing application but also for other applications, such as electrochemical, biosensing, magnetosensing and spintronic

  1. Surface functionalization of epitaxial graphene on SiC by ion irradiation for gas sensing application

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, Priya Darshni, E-mail: kaushik.priyadarshni@gmail.com [Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden); Department of Physics, Jamia Millia Islamia, New Delhi, 110025 (India); Ivanov, Ivan G.; Lin, Pin-Cheng [Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden); Kaur, Gurpreet [Department of Physics and Astrophysics, University of Delhi, Delhi, 110007 (India); Eriksson, Jens [Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden); Lakshmi, G.B.V.S. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi, 110067 (India); Avasthi, D.K. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi, 110067 (India); Amity Institute of Nanotechnology, Noida 201313 (India); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi, 110007 (India); Aziz, Anver; Siddiqui, Azher M. [Department of Physics, Jamia Millia Islamia, New Delhi, 110025 (India); Syväjärvi, Mikael [Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden); Yazdi, G. Reza, E-mail: yazdi@ifm.liu.se [Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden)

    2017-05-01

    Highlights: • For the first time the gas sensing application of SHI irradiated epitaxial graphene on SiC is explored. • Surface morphology of irradiated graphene layers showed graphene folding, hillocks, and formation of wrinkles. • Existence of an optimal fluence which maximize the gas sensing response towards NO{sub 2} and NH{sub 3} gases. - Abstract: In this work, surface functionalization of epitaxial graphene grown on silicon carbide was performed by ion irradiation to investigate their gas sensing capabilities. Swift heavy ion irradiation using 100 MeV silver ions at four varying fluences was implemented on epitaxial graphene to investigate morphological and structural changes and their effects on the gas sensing capabilities of graphene. Sensing devices are expected as one of the first electronic applications using graphene and most of them use functionalized surfaces to tailor a certain function. In our case, we have studied irradiation as a tool to achieve functionalization. Morphological and structural changes on epitaxial graphene layers were investigated by atomic force microscopy, Raman spectroscopy, Raman mapping and reflectance mapping. The surface morphology of irradiated graphene layers showed graphene folding, hillocks, and formation of wrinkles at highest fluence (2 × 10{sup 13} ions/cm{sup 2}). Raman spectra analysis shows that the graphene defect density is increased with increasing fluence, while Raman mapping and reflectance mapping show that there is also a reduction of monolayer graphene coverage. The samples were investigated for ammonia and nitrogen dioxide gas sensing applications. Sensors fabricated on pristine and irradiated samples showed highest gas sensing response at an optimal fluence. Our work provides new pathways for introducing defects in controlled manner in epitaxial graphene, which can be used not only for gas sensing application but also for other applications, such as electrochemical, biosensing, magnetosensing and

  2. High Fidelity Ion Beam Simulation of High Dose Neutron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Wirth, Brian; Motta, Athur; Morgan, Dane; Kaoumi, Djamel; Hosemann, Peter; Odette, Robert

    2018-04-30

    Project Objective: The objective of this proposal is to demonstrate the capability to predict the evolution of microstructure and properties of structural materials in-reactor and at high doses, using ion irradiation as a surrogate for reactor irradiations. “Properties” includes both physical properties (irradiated microstructure) and the mechanical properties of the material. Demonstration of the capability to predict properties has two components. One is ion irradiation of a set of alloys to yield an irradiated microstructure and corresponding mechanical behavior that are substantially the same as results from neutron exposure in the appropriate reactor environment. Second is the capability to predict the irradiated microstructure and corresponding mechanical behavior on the basis of improved models, validated against both ion and reactor irradiations and verified against ion irradiations. Taken together, achievement of these objectives will yield an enhanced capability for simulating the behavior of materials in reactor irradiations

  3. In-situ observation system for dual ion irradiation damage

    International Nuclear Information System (INIS)

    Furuno, Shigemi; Hojou, Kiichi; Otsu, Hitoshi; Sasaki, T.A.; Izui, Kazuhiko; Tukamoto, Tetsuo; Hata, Takao.

    1992-01-01

    We have developed an in-situ observation and analysis system during dual ion beam irradiation in an electron microscope. This system consists of an analytical electron microscope of JEM-4000FX type equipped with a parallel EELS and an EDS attachments and linked with two sets of ion accelerators of 40 kV. Hydrogen and helium dual-ion beam irradiation experiments were performed for SiC crystals. The result of dual-ion beam irradiation was compared with those of helium and hydrogen single ion irradiations. It is clearly seen that the dual-ion irradiation has the effect of suppressing bubble formation and growth in comparison with the case of single helium ion irradiation. (author)

  4. Ion irradiated graphite exposed to fusion-relevant deuterium plasma

    International Nuclear Information System (INIS)

    Deslandes, Alec; Guenette, Mathew C.; Corr, Cormac S.; Karatchevtseva, Inna; Thomsen, Lars; Ionescu, Mihail; Lumpkin, Gregory R.; Riley, Daniel P.

    2014-01-01

    Graphite samples were irradiated with 5 MeV carbon ions to simulate the damage caused by collision cascades from neutron irradiation in a fusion environment. The ion irradiated graphite samples were then exposed to a deuterium plasma in the linear plasma device, MAGPIE, for a total ion fluence of ∼1 × 10 24 ions m −2 . Raman and near edge X-ray absorption fine structure (NEXAFS) spectroscopy were used to characterize modifications to the graphitic structure. Ion irradiation was observed to decrease the graphitic content and induce disorder in the graphite. Subsequent plasma exposure decreased the graphitic content further. Structural and surface chemistry changes were observed to be greatest for the sample irradiated with the greatest fluence of MeV ions. D retention was measured using elastic recoil detection analysis and showed that ion irradiation increased the amount of retained deuterium in graphite by a factor of four

  5. Experimental aspects of S.H.I.C. (Swift Heavy Ion Channeling)

    International Nuclear Information System (INIS)

    Andriamonje, S.; Castro Faria, N.V. de; Chevallier, M.; Gaillard, M.J.; Genre, R.; Farizon-Mazuy, B.; Poizat, J.C.; Remillieux, J.; Hage-Ali, M.; Cohen, C.; L'Hoir, A.; Moulin, J.; Schmaus, D.

    1989-01-01

    The mean stopping power experienced by the ions of exit charge Z and the charge distribution are measured. The experimental set up description is summarized. The experiments were performed at GANIL, using hydrogenoid Xenon ions, with 25 MeV/u on a silicon crystal target. The ion channeling and energy losses are measured. The results concerning the Lyman alpha lines intensity and Xe36 + transmission as a function of the crystal orientation are presented. The suitability of LISE device, for investigating crystalline effects in heavy ion charge exchange phenomena, is confirmed

  6. Electronic energy loss of the latent track in heavy ion-irradiated polyimide

    International Nuclear Information System (INIS)

    Sun Youmei; Liu Jie; Zhang Chonghong; Wang Zhiguang; Jin Yunfan; Duan Jinglai; Song Yin

    2005-01-01

    In the interaction process of a swift heavy ion (SHI) and polymer, a latent track with radius of several nanometers appears near the ion trajectory due to the dense ionization and excitation. To describe the role of electronic energy loss (dE/dX) e , multi-layer stacks (with different dE/dX) of polyimide (PI) films were irradiated by different SHIs (1.158 GeV Fe 56 and 1.755 GeV Xe 136 ) under vacuum at room temperature. Chemical changes of modified PI films were studied by Fourier Transform Infrared (FTIR) spectroscopy. The main feature of SHI irradiation is the degradation of the functional group and creation of alkyne. The chain disruption rate of PI was investigated in the fluence range from 1 x 10 11 to 6 x 10 12 ions/cm 2 and a wider energy stopping power range (2.2 to 5.2 keV/nm for Fe 56 ions and 8.6 to 11.3 keV/nm for Xe 136 ions). Alkyne formation was observed over the electronic energy loss range of interest. Assuming the saturated track model (the damage process only occur in a cylinder of area σ), the mean degradation and alkyne formation radii in tracks were deduced for Fe and Xe ion irradiation, respectively. The results were validated by the thermal spike model and the threshold electronic energy loss of track formation S et in PI was deduced. The analysis of the irradiated PI films shows that the predictions of the thermal spike model are in qualitative agreement with the curve shape of experimental results. (authors)

  7. Materials Modification Under Ion Irradiation: JANNUS Project

    International Nuclear Information System (INIS)

    Serruys, Y.; Trocellier, P.; Ruault, M.-O.; Henry, S.; Kaietasov, O.; Trouslard, Ph.

    2004-01-01

    JANNUS (Joint Accelerators for Nano-Science and Nuclear Simulation) is a project designed to study the modification of materials using multiple ion beams and in-situ TEM observation. It will be a unique facility in Europe for the study of irradiation effects, the simulation of material damage due to irradiation and in particular of combined effects. The project is also intended to bring together experimental and modelling teams for a mutual fertilisation of their activities. It will also contribute to the teaching of particle-matter interactions and their applications. JANNUS will be composed of three accelerators with a common experimental chamber and of two accelerators coupled to a 200 kV TEM

  8. Magnetic and topographical modifications of amorphous Co–Fe thin films induced by high energy Ag{sup 7+} ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pookat, G.; Hysen, T. [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Al-Harthi, S.H.; Al-Omari, I.A. [Department of Physics, Sultan Qaboos University, Muscat, P.O. Box 36, Code 123 (Oman); Lisha, R. [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Avasthi, D.K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Anantharaman, M.R., E-mail: mra@gmail.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India)

    2013-09-01

    We have investigated the effects of swift heavy ion irradiation on thermally evaporated 44 nm thick, amorphous Co{sub 77}Fe{sub 23} thin films on silicon substrates using 100 MeV Ag{sup 7+} ions fluences of 1 × 10{sup 11} ions/cm{sup 2}, 1 × 10{sup 12} ions/cm{sup 2}, 1 × 10{sup 13} ions/cm{sup 2}, and 3 × 10{sup 13} ions/cm{sup 2}. The structural modifications upon swift heavy irradiation were investigated using glancing angle X-ray diffraction. The surface morphological evolution of thin film with irradiation was studied using Atomic Force Microscopy. Power spectral density analysis was used to correlate the roughness variation with structural modifications investigated using X-ray diffraction. Magnetic measurements were carried out using vibrating sample magnetometry and the observed variation in coercivity of the irradiated films is explained on the basis of stress relaxation. Magnetic force microscopy images are subjected to analysis using the scanning probe image processor software. These results are in agreement with the results obtained using vibrating sample magnetometry. The magnetic and structural properties are correlated.

  9. 50 MeV, Li"3"+ - ion irradiation effect on magnetic ordering of Y"3"+ - substituted yttrium iron garnet

    International Nuclear Information System (INIS)

    Sharma, P. U.; Zankat, K. B.; Dolia, S. N.; Modi, K. B.

    2016-01-01

    This communication presents the effect of non-magnetic Y"3"+ ions substitution for magnetic Fe"3"+ ions and 50 MeV, Li"3"+ ion irradiation (fluence: 5 × 10"1"3 ions/cm"2) on magnetic ordering and Neel temperature of Y_3_+_xFe_5_-_xO_1_2 (x = 0.0, 0.2, 0.4 and 0.6) garnet system, studied by means of X-ray powder diffractometry and thermal variation of low field (0.5 Oe) ac susceptibility measurements. The un-irradiated compositions exhibit normal ferrimagnetic behavior with decrease in transition temperature (T_N) on increasing Y"3"+-concentration (x). The irradiated counterparts are characterized by tailing effect indicative of non-uniform effect of irradiation and lower value of T_N. The results have been discussed based on the weakening of magnetic exchange interactions and cumulative effect of redistribution of cations and fractional creation of localized paramagnetic centers resulting from swift heavy ion irradiation. The Neel temperatures and exchange integrals have been calculated theoretically.

  10. Low-energy irradiation effects of gas cluster ion beams

    International Nuclear Information System (INIS)

    Houzumi, Shingo; Takeshima, Keigo; Mochiji, Kozo; Toyoda, Noriaki; Yamada, Isao

    2007-01-01

    A cluster-ion irradiation system with cluster-size selection has been developed to study the effects of the cluster size for surface processes using cluster ions. A permanent magnet with a magnetic field of 1.2 T is installed for size separation of large cluster ions. Trace formations at HOPG surface by the irradiation with size-selected Ar-cluster ions under acceleration energy of 30 keV were investigated by a scanning tunneling microscopy. Generation behavior of the crater-like traces is strongly affected by the number of constituent atoms (cluster size) of the irradiating cluster ion. When the incident cluster ion is composed of 100-3000 atoms, crater-like traces are observed on the irradiated surfaces. In contrast, such traces are not observed at all with the irradiation of the cluster-ions composed of over 5000 atoms. Such the behavior is discussed on the basis of the kinetic energy per constituent atom of the cluster ion. To study GCIB irradiation effects against macromolecule, GCIB was irradiated on DNA molecules absorbed on graphite surface. By the GCIB irradiation, much more DNA molecules was sputtered away as compared with the monomer-ion irradiation. (author)

  11. 160 MeV Ni12+ ion irradiation effects on the structural, optical and electrical properties of spherical polypyrrole nanoparticles

    International Nuclear Information System (INIS)

    Hazarika, J.; Kumar, A.

    2014-01-01

    Highlights: • Upon SHI irradiation the average diameters of PPy nanoparticles increases. • Crystallinity of PPy nanoparticles increases with increasing ion fluence. • IR active vibrational bands have different cross sections for SHI irradiation. • Upon SHI irradiation optical band gap energy of PPy nanoparticles decreases. • Upon SHI irradiation thermal stability of PPy nanoparticles increases. -- Abstract: In this study we report 160 MeV Ni 12+ swift heavy ion irradiation induced enhancement in the structural, optical and electrical properties of spherical polypyrrole (PPy) nanoparticles. High resolution transmission electron microscope results show that the pristine PPy nanoparticles have an average diameter of 11 nm while upon irradiation the average diameter increases to 18 nm at the highest ion fluence of 1 × 10 12 ions/cm 2 . X-ray diffraction studies show an enhancement of crystallinity and average crystallite size of PPy nanoparticles with increasing fluence. Studies of Fourier transform infrared spectra suggest the structural modifications of different functional groups upon irradiation. It also reveals that different functional groups have different sensitivity to irradiation. The infrared active N–H vibrational band at 3695 cm −1 is more sensitive to irradiation with a formation cross-section of 5.77 × 10 −13 cm 2 and effective radius of 4.28 nm. The UV–visible absorption spectra of PPy nanoparticles show that the absorption band undergoes a red shift with increasing fluence. Moreover upon irradiation the optical band gap energy decreases and Urbach’s energy increases with fluence. Thermo-gravimetric analysis studies suggest that upon irradiation the thermal stability of PPy nanoparticles increases which may be attributed to their enhanced crystallinity. Current–voltage characteristics of PPy nanoparticles exhibit non-Ohmic, symmetric behavior which increases with fluence

  12. Ionic conduction in 70-MeV C5+-ion-irradiated poly(vinylidenefluoride- co-hexafluoropropylene)-based gel polymer electrolytes

    International Nuclear Information System (INIS)

    Saikia, D.; Kumar, A.; Singh, F.; Avasthi, D.K.; Mishra, N.C.

    2005-01-01

    In an attempt to increase the Li + -ion diffusivity, poly(vinylidenefluoride-co-hexafluoropropylene)-(propylene carbonate+diethyl carbonate)-lithium perchlorate gel polymer electrolyte system has been irradiated with 70-MeV C 5+ -ion beam of nine different fluences. Swift heavy-ion irradiation shows enhancement in ionic conductivity at lower fluences and decrease in ionic conductivity at higher fluences with respect to unirradiated gel polymer electrolyte films. Maximum room-temperature (303 K) ionic conductivity is found to be 2x10 -2 S/cm after irradiation with a fluence of 10 11 ions/cm 2 . This interesting result could be attributed to the fact that for a particular ion beam with a given energy, a higher fluence provides critical activation energy for cross linking and crystallization to occur, which results in the decrease in ionic conductivity. X-ray-diffraction results show decrease in the degree of crystallinity upon ion irradiation at low fluences (≤10 11 ions/cm 2 ) and increase in crystallinity at higher fluences (>10 11 ions/cm 2 ). Analysis of Fourier-transform infrared spectroscopy results suggests the bond breaking at a fluence of 5x10 9 ions/cm 2 and cross linking at a fluence of 10 12 ions/cm 2 and corroborate conductivity and x-ray-diffraction results. Scanning electron micrographs exhibit increased porosity of the polymer electrolyte after ion irradiation

  13. Studies of defects on ion irradiated diamond

    Energy Technology Data Exchange (ETDEWEB)

    Lai, P F; Prawer, S; Spargo, A E.C.; Bursill, L A [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    It is known that diamond is amorphized or graphitized when irradiated above a critical dose. Above this critical dose, D{sub c}, the resistance R is found to drop very rapidly due to the formation of graphite regions which overlap at D{sub c} to form a semi-continuous electrically conducting pathway through the sample. One particularly interesting method of studying this transformation is electron energy-loss spectroscopy (EELS). Using EELS, the different phases of carbon can be identified and distinguished from each other using the extended energy-loss fine structure (EXELFS) of the core-loss part of the spectrum. EELS is a sensitive method for determining the electronic structure of small areas of a sample. In this paper, transmission electron microscopy (TEM) and EELS measurements of the ion irradiated diamond were combined in an attempt to correlate the microstructural nature of the ion-beam induced damage to the changes in the electrical and other properties. 7 refs., 1 tab., 2 figs.

  14. Studies of defects on ion irradiated diamond

    Energy Technology Data Exchange (ETDEWEB)

    Lai, P.F.; Prawer, S.; Spargo, A.E.C.; Bursill, L.A. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    It is known that diamond is amorphized or graphitized when irradiated above a critical dose. Above this critical dose, D{sub c}, the resistance R is found to drop very rapidly due to the formation of graphite regions which overlap at D{sub c} to form a semi-continuous electrically conducting pathway through the sample. One particularly interesting method of studying this transformation is electron energy-loss spectroscopy (EELS). Using EELS, the different phases of carbon can be identified and distinguished from each other using the extended energy-loss fine structure (EXELFS) of the core-loss part of the spectrum. EELS is a sensitive method for determining the electronic structure of small areas of a sample. In this paper, transmission electron microscopy (TEM) and EELS measurements of the ion irradiated diamond were combined in an attempt to correlate the microstructural nature of the ion-beam induced damage to the changes in the electrical and other properties. 7 refs., 1 tab., 2 figs.

  15. An attempt to apply the inelastic thermal spike model to surface modifications of CaF2 induced by highly charged ions: comparison to swift heavy ions effects and extension to some others material.

    Science.gov (United States)

    Dufour, C; Khomrenkov, V; Wang, Y Y; Wang, Z G; Aumayr, F; Toulemonde, M

    2017-03-08

    Surface damage appears on materials irradiated by highly charged ions (HCI). Since a direct link has been found between surface damage created by HCI with the one created by swift heavy ions (SHI), the inelastic thermal spike model (i-TS model) developed to explain track creation resulting from the electron excitation induced by SHI can also be applied to describe the response of materials under HCI which transfers its potential energy to electrons of the target. An experimental description of the appearance of the hillock-like nanoscale protrusions induced by SHI at the surface of CaF 2 is presented in comparison with track formation in bulk which shows that the only parameter on which we can be confident is the electronic energy loss threshold. Track size and electronic energy loss threshold resulting from SHI irradiation of CaF 2 is described by the i-TS model in a 2D geometry. Based on this description the i-TS model is extended to three dimensions to describe the potential threshold of appearance of protrusions by HCI in CaF 2 and to other crystalline materials (LiF, crystalline SiO 2 , mica, LiNbO 3 , SrTiO 3 , ZnO, TiO 2 , HOPG). The strength of the electron-phonon coupling and the depth in which the potential energy is deposited near the surface combined with the energy necessary to melt the material defines the classification of the material sensitivity. As done for SHI, the band gap of the material may play an important role in the determination of the depth in which the potential energy is deposited. Moreover larger is the initial potential energy and larger is the depth in which it is deposited.

  16. Structural modifications induced by ion irradiation and temperature in boron carbide B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Victor, G., E-mail: g.victor@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pipon, Y.; Bérerd, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); CEA-DEN, Saclay, 91191 Gif-sur-Yvette (France); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Djourelov, N. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee blvd, BG-1784 Sofia (Bulgaria); ELI-NP, IFIN-HH, 30 Reactorului Str, MG-6 Bucharest-Magurele (Romania); Miro, S. [CEA-DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Baillet, J. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pradeilles, N.; Rapaud, O.; Maître, A. [SPCTS, UMR CNRS 7315, Centre Européen de la céramique, University of Limoges (France); Gosset, D. [CEA, Saclay, DMN-SRMA-LA2M, 91191 Gif-sur-Yvette (France)

    2015-12-15

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B{sub 4}C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B{sub 4}C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (S{sub e} ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B{sub 4}C structure under irradiation.

  17. Structural modifications induced by ion irradiation and temperature in boron carbide B4C

    Science.gov (United States)

    Victor, G.; Pipon, Y.; Bérerd, N.; Toulhoat, N.; Moncoffre, N.; Djourelov, N.; Miro, S.; Baillet, J.; Pradeilles, N.; Rapaud, O.; Maître, A.; Gosset, D.

    2015-12-01

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B4C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B4C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (Se ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B4C structure under irradiation.

  18. Hydrogen retention in ion irradiated steels

    International Nuclear Information System (INIS)

    Hunn, J.D.; Lewis, M.B.; Lee, E.H.

    1998-01-01

    In the future 1--5 MW Spallation Neutron Source, target radiation damage will be accompanied by high levels of hydrogen and helium transmutation products. The authors have recently carried out investigations using simultaneous Fe/He,H multiple-ion implantations into 316 LN stainless steel between 50 and 350 C to simulate the type of radiation damage expected in spallation neutron sources. Hydrogen and helium were injected at appropriate energy and rate, while displacement damage was introduced by nuclear stopping of 3.5 MeV Fe + , 1 microm below the surface. Nanoindentation measurements showed a cumulative increase in hardness as a result of hydrogen and helium injection over and above the hardness increase due to the displacement damage alone. TEM investigation indicated the presence of small bubbles of the injected gases in the irradiated area. In the current experiment, the retention of hydrogen in irradiated steel was studied in order to better understand its contribution to the observed hardening. To achieve this, the deuterium isotope ( 2 H) was injected in place of natural hydrogen ( 1 H) during the implantation. Trapped deuterium was then profiled, at room temperature, using the high cross-section nuclear resonance reaction with 3 He. Results showed a surprisingly high concentration of deuterium to be retained in the irradiated steel at low temperature, especially in the presence of helium. There is indication that hydrogen retention at spallation neutron source relevant target temperatures may reach as high as 10%

  19. Study of elementary transfer mechanisms during a collision between a swift multi-charged heavy ion and a neutral atom

    International Nuclear Information System (INIS)

    Jardin, P.

    1995-01-01

    This work is dedicated to the study of the energy transfer mechanisms which occur during a collision between a swift multicharged heavy ion and a neutral atom. The elementary energy energy transfer mechanisms (scattering, excitation, ionization, capture) and their consequences on the target velocity after the collision (recoil velocity) are recalled in the first chapter. In the case of small projectile diffusion angles, we show that the recoil velocity component, transverse to the incident projectile direction, results principally from the diffusion mechanism, while the longitudinal component is due essentially to the mass transfer and the inelastic energy transfer mechanisms. Since the target recoil velocities are very small, we have built an experimental set-up which reduces the impreciseness on their measurement due to the target thermal spread using, as targets, cooled atoms of a supersonic jet (temperature 44+ (6.7 MeV/A) + Ar => Xe 44 + Ar q+ +qe - (q ranging from 1 to 7); Xe 44+ (6.7 MeV/A) + He => Xe 44+ He 1+,2+ +1e - ,2e - . We show that it is possible to interpret the recoil velocity in terms of kinetic energy transferred to the target and to the electrons ejected from the target. (author)

  20. RBE of cells irradiated by carbon ions

    International Nuclear Information System (INIS)

    Li Wenjian; Zhou Guangming; Wei Zengquan; Wang Jufang; Dang Bingrong; Li Qiang; Xie Hongmei

    2002-01-01

    The mouse melanoma cells (B16), human cervical squamous carcinoma cells (HeLa), Chinese hamster pulmonary cells V79, and human hepatoma cells (SMMC-7721) were collected for studying. The cells of 5 x 10 5 /ml were seeded in 35 mm diameter petri dish and allowed to grow one day, and then the medium in petri dishes was removed away, the cells were washed once with phosphate-buffered saline (PBS), petri dishes was covered with 4μm thickness Mylar film. The cells were irradiated by 12 C ion beam with LETs of 125.5, 200, 700 keV/μm in water generated from HIRFL (Heavy Ion Research Facility in Lanzhou). For 60 Co γ-ray experiment, the cells of 5 x 10 4 /ml were grown in 20 ml culture flasks including 1.5 ml cell suspension and directly used for irradiation. Following irradiation, the cells were trypsinized, counted, plated at appropriate densities in growth medium and then seeded in 60 mm diameter culture dishes. Each dish was filled 4 ml standard medium, and incubated for 8-12 days at 37 degree C incubator containing 5% CO 2 . The cultures were then rinsed with PBS buffer at pH 6.8, fixed with Carnoy's fluid, stained for 8 min with Giemsa (1:20, pH 6.8), and colonies containing more than 50 cells were scored. Their relative biological effectivenesses (RBE) were investigated. The results show that RBE depends on cellular types and increases with increasing of cellular survival level when LET is at 125.5 keV/μm, and decreases with increasing LET when LET ≥ 125.5 keV/μm

  1. Irradiation swelling in self-ion irradiated niobium

    International Nuclear Information System (INIS)

    Bajaj, R.; Shiels, S.A.; Hall, B.O.; Fenske, G.R.

    1987-01-01

    This paper presents initial results of an investigation of swelling mechanisms in a model body centered cubic (bcc) metal, niobium, irradiated at elevated temperatures (0.3 T/sub m/ to 0.6 T/sub m/) where T/sub m/ = melting point in K. The objective of this work is to achieve an understanding of the elevated temperature swelling in bcc metals, which are the prime candidate alloys and composite matrix materials for space reactor applications. Niobium was irradiated with 5.3 MeV Nb ++ ions, at temperatures ranging from 700 0 C to 1300 0 C, to a nominal dose of 50 dpa at a dose rate of 6 x 10 -3 dpas. Swelling was observed over a temperature range of 700 0 C to 1200 0 C, with a peak swelling of 7% at 900 0 C. The microstructural data, obtained from transmission electron microscopy, were compared to the predictions of the theoretical model developed during this program. A reasonable agreement was obtained between the experimental measurements of swelling and theoretical predictions by adjusting both the niobium-oxygen binding energy and the incubation dose for swelling to realistic values

  2. Heavy ion irradiation of crystalline water ice. Cosmic ray amorphisation cross-section and sputtering yield

    Science.gov (United States)

    Dartois, E.; Augé, B.; Boduch, P.; Brunetto, R.; Chabot, M.; Domaracka, A.; Ding, J. J.; Kamalou, O.; Lv, X. Y.; Rothard, H.; da Silveira, E. F.; Thomas, J. C.

    2015-04-01

    Context. Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. Aims: We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. Methods: We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). Results: The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic stopping power. Conclusions: The final state of cosmic ray irradiation for porous amorphous and crystalline ice, as monitored by infrared spectroscopy, is the same, but with a large difference in cross-section, hence in time scale in an astrophysical context. The cosmic ray water-ice sputtering rates compete with the UV photodesorption yields reported in the literature. The prevalence of direct cosmic ray sputtering over cosmic-ray induced photons photodesorption may be particularly true for ices strongly bonded to the ice mantles surfaces, such as hydrogen-bonded ice structures or more generally the so-called polar ices. Experiments performed at the Grand Accélérateur National d'Ions Lourds (GANIL) Caen, France. Part of this work has been financed by the French INSU-CNRS programme "Physique et Chimie du Milieu Interstellaire" (PCMI) and the ANR IGLIAS.

  3. Rows of Dislocation Loops in Aluminium Irradiated by Aluminium Ions

    DEFF Research Database (Denmark)

    Henriksen, L.; Johansen, A.; Koch, J.

    1967-01-01

    Single-crystal aluminium specimens, irradiated with 50-keV aluminium ions, contain dislocation loops that are arranged in regular rows along <110 > directions. ©1967 The American Institute of Physics......Single-crystal aluminium specimens, irradiated with 50-keV aluminium ions, contain dislocation loops that are arranged in regular rows along directions. ©1967 The American Institute of Physics...

  4. Ionic conduction studies in Li3+ ion irradiated P(VDF-HFP)-(PC + DEC)-LiCF3SO3 gel polymer electrolyte

    International Nuclear Information System (INIS)

    Saikia, D.; Hussain, A.M.P.; Kumar, A.; Singh, F.; Avasthi, D.K.

    2006-01-01

    In an attempt to increase the Li ion diffusivity in gel polymer electrolytes, the effects of Li 3+ ion irradiation in P(VDF-HFP)-(PC + DEC)-LiCF 3 SO 3 electrolyte system, with five different fluences, is studied. Irradiation with swift heavy ions shows enhancement in conductivity at low fluences and decreased in conductivity at higher fluences with respect to pristine polymer electrolyte films. Maximum room temperature ionic conductivity after irradiation is found to be 2.6 x 10 -3 S/cm. This interesting result could be attributed to the fact that, higher fluence provides critical activation energy for cross-linking and crystallization to occur, which results in decrease in ionic conductivity. XRD results show decrease in the degree of crystallinity upon ion irradiation at low fluences (≤10 11 ions/cm 2 ) and increase in crystallinity at high fluences (>10 11 ions/cm 2 ). In FTIR spectra the absorption band intensities around 3025 cm -1 and 2985 cm -1 decrease upon irradiation with a fluence of 5 x 10 1 ions/cm 2 suggesting chain scission and increase upon irradiation with a fluence of 5 x 10 12 ions/cm 2 indicating cross-linking. FTIR analyses corroborate the conductivity and XRD results

  5. Amorphous molecular junctions produced by ion irradiation on carbon nanotubes

    International Nuclear Information System (INIS)

    Wang Zhenxia; Yu Liping; Zhang Wei; Ding Yinfeng; Li Yulan; Han Jiaguang; Zhu Zhiyuan; Xu Hongjie; He Guowei; Chen Yi; Hu Gang

    2004-01-01

    Experiments and molecular dynamics have demonstrated that electron irradiation could create molecular junctions between crossed single-wall carbon nanotubes. Recently molecular dynamics computation predicted that ion irradiation could also join single-walled carbon nanotubes. Employing carbon ion irradiation on multi-walled carbon nanotubes, we find that these nanotubes evolve into amorphous carbon nanowires, more importantly, during the process of which various molecular junctions of amorphous nanowires are formed by welding from crossed carbon nanotubes. It demonstrates that ion-beam irradiation could be an effective way not only for the welding of nanotubes but also for the formation of nanowire junctions

  6. Spectroscopic characterization of ion-irradiated multi-layer graphenes

    Energy Technology Data Exchange (ETDEWEB)

    Tsukagoshi, Akira [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Honda, Shin-ichi, E-mail: s-honda@eng.u-hyogo.ac.jp [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Osugi, Ryo [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Okada, Hiraku [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); Niibe, Masahito [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Kamigori, Hyogo 678-1205 (Japan); Terasawa, Mititaka [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Kamigori, Hyogo 678-1205 (Japan); RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Hirase, Ryuji; Izumi, Hirokazu; Yoshioka, Hideki [Hyogo Prefectural Institute of Technology, Kobe 654-0037 (Japan); Niwase, Keisuke [Hyogo University of Teacher Education, Kato, Hyogo 673-1494 (Japan); Taguchi, Eiji [Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Lee, Kuei-Yi [Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Oura, Masaki [RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan)

    2013-11-15

    Low-energy Ar ions (0.5–2 keV) were irradiated to multi-layer graphenes and the damage process, the local electronic states, and the degree of alignment of the basal plane, and the oxidation process upon ion irradiation were investigated by Raman spectroscopy, soft X-ray absorption spectroscopy (XAS) and in situ X-ray photoelectron spectroscopy (XPS). By Raman spectroscopy, we observed two stages similar to the case of irradiated graphite, which should relate to the accumulations of vacancies and turbulence of the basal plane, respectively. XAS analysis indicated that the number of sp{sup 2}-hybridized carbon (sp{sup 2}-C) atoms decreased after ion irradiation. Angle-resolved XAS revealed that the orientation parameter (OP) decreased with increasing ion energy and fluence, reflecting the turbulence of the basal plane under irradiation. In situ XPS shows the oxidation of the irradiated multi-layer graphenes after air exposure.

  7. Fragmentation of water on swift {sup 3}He{sup 2+} ion impact

    Energy Technology Data Exchange (ETDEWEB)

    Sabin, John R. [Quantum Theory Project, Departments of Chemistry and Physics, P.O. Box 118435, University of Florida, Gainesville, FL 32611-8435 (United States); Institut for Fysik og Kemi, Suddansk Universitet, 5230 Odense M (Denmark)], E-mail: sabin@qtp.ufl.edu; Cabrerra-Trujillo, Remigio [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, Cuernavaca, Morelos 62251 (Mexico); Stolterfoht, Nikolaus [Hahn-Meitner Institut, Glienickerstrasse 100, D-14109 Berlin (Germany); Deumens, Erik; Ohrn, Yngve [Quantum Theory Project, Departments of Chemistry and Physics, P.O. Box 118435, University of Florida, Gainesville, FL 32611-8435 (United States)

    2009-01-15

    Charge exchange and fragmentation are the usual results in ion-molecule collision systems, and the specifics of the fragmentation process determine the chemical destiny of the target system. In this paper, we report recent progress on calculations of the fragmentation patterns for the model system He{sup 2+} + H{sub 2}O for projectile energies of a few keV. The calculations are obtained using the electron-nuclear dynamics (END) method for solution of the time-dependent Schroedinger equation.

  8. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi; Shimizu, Takashi; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yamashita, Takao

    1997-03-01

    To investigate the effect of local irradiation with ion beams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ion beams suggests that the efficient pollen envelope damages would be induced at the range-end of ion beams. (author)

  9. Mono and sequential ion irradiation induced damage formation and damage recovery in oxide glasses: Stopping power dependence of the mechanical properties

    International Nuclear Information System (INIS)

    Mir, A.H.; Monnet, I.; Toulemonde, M.; Bouffard, S.; Jegou, C.; Peuget, S.

    2016-01-01

    Simple and complex borosilicate glasses were irradiated with single and double ion beams of light and heavy ions over a broad fluence and stopping power range. As a result of the heavy ion irradiation (U, Kr, Au), the hardness was observed to diminish and saturate after a decrease by 35 ± 1%. Unlike slow and swift heavy ion irradiation, irradiation with light ions (He,O) induced a saturation hardness decrease of 18 ± 1% only. During double ion beam irradiation; where glasses were first irradiated with a heavy ion (gold) and then by a light ion (helium), the light ion irradiation induced partial damage recovery. As a consequence of the recovery effect, the hardness of the pre-irradiated glasses increased by 10–15% depending on the chemical composition. These results highlight that the nuclear energy loss and high electronic energy loss (≥4 keV/nm) result in significant and similar modifications whereas light ions with low electronic energy loss (≤1 keV/nm) result in only mild damage formation in virgin glasses and recovery in highly pre-damaged glasses. These results are important to understand the damage formation and recovery in actinide bearing minerals and in glasses subjected to self-irradiation by alpha decays. - Highlights: • Behavior of glasses strongly depends on the electronic energy loss (Se) of the ions. • High Se (≥4 keV/nm) induces large changes in comparison to lower Se values. • Apart from mild damage formation, low Se causes recovery of pre-existing damage. • Alpha induced partial recovery of the damage would occur in nuclear waste glasses.

  10. Ion irradiation of CH4-containing icy mixtures

    International Nuclear Information System (INIS)

    Baratta, G.A.; Domingo, M.; Ferini, G.; Leto, G.; Palumbo, M.E.; Satorre, M.A.; Strazzulla, G.

    2003-01-01

    We have studied by infrared absorption spectroscopy the effects of ion irradiation with 60 keV Ar 2+ ions on pure methane (CH 4 ) ice at 12 K and mixtures with water (H 2 O) and nitrogen (N 2 ). Ion irradiation, among other effects, causes the rupture of original molecular bonds and the formation of molecular species not present in the initial ice. Here we present the experimental results and discuss their astrophysical relevance

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

    International Nuclear Information System (INIS)

    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)

  12. On the invalidity of Bragg's rule in stopping cross sections of molecules for swift Li ions

    International Nuclear Information System (INIS)

    Neuwirth, W.; Pietsch, W.; Richter, K.; Hauser, U.

    1975-01-01

    We discuss the invalidity of Bragg's rule for stopping cross sections of molecules for Li ions in the velocity range 1.5 x 10 8 cm/sec to 4.8 x 10 8 cm/sec. Here the influence of the chemical bonding in a molecule normally leads to strong deviations from Bragg's additivity rule. In our boron compounds the measured cross section of the molecule is smaller than the sum of the stopping cross sections of the single constituents. This can be explained in a first order description by the transfer of electrons in the bonding. With this description it is possible to determine from the measured molecular stopping cross sections the charge transfer in certain compounds. (orig.) [de

  13. Temperature annealing of tracks induced by ion irradiation of graphite

    International Nuclear Information System (INIS)

    Liu, J.; Yao, H.J.; Sun, Y.M.; Duan, J.L.; Hou, M.D.; Mo, D.; Wang, Z.G.; Jin, Y.F.; Abe, H.; Li, Z.C.; Sekimura, N.

    2006-01-01

    Highly oriented pyrolytic graphite (HOPG) samples were irradiated by Xe ions of initial kinetic energy of 3 MeV/u. The irradiations were performed at temperatures of 500 and 800 K. Scanning tunneling microscopy (STM) images show that the tracks occasionally have elongated structures under high-temperature irradiation. The track creation yield at 800 K is by three orders of magnitude smaller compared to that obtained during room-temperature irradiation. STM and Raman spectra show that amorphization occurs in graphite samples irradiated at 500 K to higher fluences, but not at 800 K. The obtained experimental results clearly reveal that the irradiation under high temperature causes track annealing

  14. 125 MeV Si 9+ ion irradiation of calcium phosphate thin film coated by rf-magnetron sputtering technique

    Science.gov (United States)

    Elayaraja, K.; Joshy, M. I. Ahymah; Suganthi, R. V.; Kalkura, S. Narayana; Palanichamy, M.; Ashok, M.; Sivakumar, V. V.; Kulriya, P. K.; Sulania, I.; Kanjilal, D.; Asokan, K.

    2011-01-01

    Titanium substrate was coated with hydroxyapatite by radiofrequency magnetron sputtering (rf-magnetron sputtering) technique and subjected to swift heavy ion (SHI) irradiation of 125 MeV with Si 9+ at fluences of 1 × 10 10, 1 × 10 11 and 1 × 10 12 ions/cm 2. The glancing incidence X-ray diffraction (GIXRD) analysis confirmed the HAp phase of the irradiated film. There was a considerable decrease in crystallinity and particle size after irradiation. In addition, DRS-UV reflectance spectra revealed a decrease in optical band gap ( Eg) from 5.2 to 4.6 eV. Wettability of biocompatible materials plays an important role in biological cells proliferation for tissue engineering, drug delivery, gene transfer and bone growth. HAp thin films irradiated with 1 × 10 11 ions/cm 2 fluence showed significant increase in wettability. While the SHI irradiated samples exhibited enhanced bioactivity, there was no significant variation in cell viability. Surface roughness, pores and average particle size were analyzed by atomic force microscopy (AFM).

  15. Swift essentials

    CERN Document Server

    Blewitt, Alex

    2014-01-01

    Whether you are a seasoned Objective-C developer or new to the Xcode platform, Swift Essentials will provide you with all you need to know to get started with the language. Prior experience with iOS development is not necessary, but will be helpful to get the most out of the book.

  16. Augmentation of thermoelectric performance of VO2 thin films irradiated by 200 MeV Ag9+-ions

    International Nuclear Information System (INIS)

    Khan, G.R.; Kandasami, A.; Bhat, B.A.

    2016-01-01

    Swift Heavy Ion (SHI) irradiation with 200 MeV Ag 9+ -ion beam at ion fluences of 1E11, 5E11, 1E12, and 5E12 for tuning of electrical transport properties of VO 2 thin films fabricated by so–gel technique on alumina substrates has been demonstrated in the present paper. The point defects created by SHI irradiation modulate metal to insulator phase transition temperature, carrier concentration, carrier mobility, electrical conductivity, and Seebeck coefficient of VO 2 thin films. The structural properties of the films were characterized by XRD and Raman spectroscopy and crystallite size was found to decrease upon irradiation. The atomic force microscopy revealed that the surface roughness of specimens first decreased and then increased with increasing fluence. Both resistance as well as Seebeck coefficient measurements demonstrated that all the samples exhibit metal–insulator phase transition and the transition temperatures decreases with increasing fluence. Hall effect measurements exhibited that carrier concentration increased continuously with increasing fluence which resulted in an increase of electrical conductivity by several orders of magnitude in the insulating phase. Seebeck coefficient in insulating phase remained almost constant in spite of an increase in the electrical conductivity by several orders of magnitude making SHI irradiation an alternative stratagem for augmentation of thermoelectric performance of the materials. The carrier mobility at room temperature decreased up to the beam fluence of 5E11 and then started increasing whereas Seebeck coefficient in metallic state first increased with increasing ion beam fluence up to 5E11 and thereafter decreased. Variation of these electrical transport parameters has been explained in detail. - Highlights: • Thermoelectric properties of VO 2 thin films enhance upon SHI irradiation. • Structural properties show that crystallite size decrease upon SHI irradiation. • Metal–insulator phase

  17. Stereophotogrammetric study of surface topography in ion irradiated silver

    International Nuclear Information System (INIS)

    Sokolov, V.N.; Fayazov, I.M.

    1993-01-01

    The irradiated surface topography of polycrystalline silver was studied using the stereophotogrammetric method. The surface of silver was irradiated with 30 keV argon ions at variation for the ion incidence angle in interval of 0-80 deg relative to a surface normal. The influence of the inclination angle of the sample in the SEM on the cone shape of a SEM-picture of the irradiated surface is discussed. The parameters of cones on the irradiated surface of silver were measured by the SEM-stereomethod. The measurements of the sample section perpendicular to the incidence plane are also carried out

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

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, R.P. [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Hareesh, K., E-mail: appi.2907@gmail.com [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Bankar, A. [Department of Microbiology, Waghire College, Pune 412301 (India); Sanjeev, Ganesh [Microtron Centre, Department of Studies in Physics, Mangalore University, Mangalore 574166 (India); Asokan, K.; Kanjilal, D. [Inter University Accelerator Centre, Arun Asaf Ali Marg, New Delhi 110067 (India); Dahiwale, S.S.; Bhoraskar, V.N. [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India)

    2016-10-01

    Highlights: • PC films were irradiated by 60 and 120 MeV Fe ions. • Irradiated PC films showed changes in its physical and chemical properties. • Irradiated PC also showed more anti-biofilm activity compared to pristine PC. - Abstract: Polycarbonate (PC) polymers were investigated before and after high energy heavy ion irradiation for anti-bacterial properties. These PC films were irradiated by Fe heavy ions with two energies, viz, 60 and 120 MeV, at different fluences in the range from 1 × 10{sup 11} ions/cm{sup 2} to 1 × 10{sup 13} ions/cm{sup 2}. UV-Visible spectroscopic results showed optical band gap decreased with increase in ion fluences due to chain scission mainly at carbonyl group of PC which is also corroborated by Fourier transform infrared spectroscopic results. X-ray diffractogram results showed decrease in crystallinity of PC after irradiation which leads to decrease in molecular weight. This is confirmed by rheological studies and also by differential scanning calorimetric results. The irradiated PC samples showed modification in their surfaces prevents biofilm formation of human pathogen, Salmonella typhi.

  19. Progress and tendency in heavy ion irradiation mutation breeding

    International Nuclear Information System (INIS)

    Zhou Libin; Li Wenjian; Qu Ying; Li Ping

    2008-01-01

    In recent years, the intermediate energy heavy ion biology has been concerned rarely comparing to that of the low-energy ions. In this paper, we summarized the advantage of a new mutation breeding method mediated by intermediate energy heavy ion irradiations. Meanwhile, the present state of this mutation technique in applications of the breeding in grain crops, cash crops and model plants were introduced. And the preview of the heavy ion irradiations in gene-transfer, molecular marker assisted selection and spaceflight mutation breeding operations were also presented. (authors)

  20. Enhanced electrochemical etching of ion irradiated silicon by localized amorphization

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Z. Y.; Breese, M. B. H. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore Singapore 117542 (Singapore); Lin, Y.; Tok, E. S. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Vittone, E. [Physics Department, NIS Excellence Centre and CNISM, University of Torino, via Pietro Giuria 1, 10125 Torino (Italy)

    2014-05-12

    A tailored distribution of ion induced defects in p-type silicon allows subsequent electrochemical anodization to be modified in various ways. Here we describe how a low level of lattice amorphization induced by ion irradiation influences anodization. First, it superposes a chemical etching effect, which is observable at high fluences as a reduced height of a micromachined component. Second, at lower fluences, it greatly enhances electrochemical anodization by allowing a hole diffusion current to flow to the exposed surface. We present an anodization model, which explains all observed effects produced by light ions such as helium and heavy ions such as cesium over a wide range of fluences and irradiation geometries.

  1. Effect of ion beam irradiation on metal particle doped polymer ...

    Indian Academy of Sciences (India)

    and converts polymeric structure into hydrogen depleted carbon network. ... Composite materials; ion beam irradiation; dielectric properties; X-ray diffraction. ..... Coat. Technol. 201 8225. Raja V, Sharma A K and Narasimha V V R 2004 Mater.

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

    Science.gov (United States)

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

    2017-01-01

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

  3. Radiation hardening of metals irradiated by heavy ions

    International Nuclear Information System (INIS)

    Didyk, A.Yu.; Skuratov, V.A.; Mikhajlova, N.Yu.; Regel', V.R.

    1988-01-01

    The damage dose dependence in the 10 -4 -10 -2 dpa region of radiation hardening of Al, V, Ni, Cu irradiated by xenon ions with 124 MeV energy is investigated using the microhardness technique and transmission electron microscope. It is shown that the pure metals radiation hardening is stimulated for defects clusters with the typical size less than 5 nm, as in the case of neutron and the light charge ion irradiation

  4. Stability of uranium silicides during high energy ion irradiation

    International Nuclear Information System (INIS)

    Birtcher, R.C; Wang, L.M.

    1991-11-01

    Changes induced by 1.5 MeV Kr ion irradiation of both U 3 Si and U 3 Si 2 have been followed by in situ transmission electron microscopy. When irradiated at sufficiently low temperatures, both alloys transform from the crystalline to the amorphous state. When irradiated at temperatures above the temperature limit for ion beam amorphization, both compounds disorder with the Martensite twin structure in U 3 Si disappearing from view in TEM. Prolonged irradiation of the disordered crystalline phases results in nucleation of small crystallites within the initially large crystal grains. The new crystallites increase in number during continued irradiation until a fine grain structure is formed. Electron diffraction yields a powder-like diffraction pattern that indicates a random alignment of the small crystallites. During a second irradiation at lower temperatures, the small crystallizes retard amorphization. After 2 dpa at high temperatures, the amorphization dose is increased by over twenty times compared to that of initially unirradiated material

  5. Effect of irradiation temperature on microstructural changes in self-ion irradiated austenitic stainless steel

    Science.gov (United States)

    Jin, Hyung-Ha; Ko, Eunsol; Lim, Sangyeob; Kwon, Junhyun; Shin, Chansun

    2017-09-01

    We investigated the microstructural and hardness changes in austenitic stainless steel after Fe ion irradiation at 400, 300, and 200 °C using transmission electron microscopy (TEM) and nanoindentation. The size of the Frank loops increased and the density decreased with increasing irradiation temperature. Radiation-induced segregation (RIS) was detected across high-angle grain boundaries, and the degree of RIS increases with increasing irradiation temperature. Ni-Si clusters were observed using high-resolution TEM in the sample irradiated at 400 °C. The results of this work are compared with the literature data of self-ion and proton irradiation at comparable temperatures and damage levels on stainless steels with a similar material composition with this study. Despite the differences in dose rate, alloy composition and incident ion energy, the irradiation temperature dependence of RIS and the size and density of radiation defects followed the same trends, and were very comparable in magnitude.

  6. Magnetic patterning by means of ion irradiation and implantation

    International Nuclear Information System (INIS)

    Fassbender, J.; McCord, J.

    2008-01-01

    A pure magnetic patterning by means of ion irradiation which relies on a local modification of the magnetic anisotropy of a magnetic multilayer structure has been first demonstrated in 1998. Since then also other magnetic properties like the interlayer exchange coupling, the exchange bias effect, the magnetic damping behavior and the saturation magnetization to name a few have also been demonstrated to be affected by ion irradiation or ion implantation. Consequently, all these effects can be used if combined with a masking technique or employing direct focused ion beam writing for a magnetic patterning and thus an imprinting of an artificial magnetic domain structure, which subsequently modifies the integral magnetization reversal behavior or the magnetization dynamics of the film investigated. The present review will summarize how ion irradiation and implantation can affect the magnetic properties by means of structural modifications. The main part will cover the present status with respect to the pure magnetic patterning of micro- and nano structures

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

    International Nuclear Information System (INIS)

    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

  8. Recovery effects due to the interaction between nuclear and electronic energy losses in SiC irradiated with a dual-ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Thomé, Lionel, E-mail: thome@csnsm.in2p3.fr; Debelle, Aurélien; Garrido, Frédérico; Sattonnay, Gaël; Mylonas, Stamatis [Centre de Sciences Nucléaires et de Sciences de la Matière, CNRS-IN2P3-Université Paris-Sud, Bât. 108, F-91405 Orsay (France); Velisa, Gihan [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O.B. MG-6, 077125 Magurele (Romania); Miro, Sandrine; Trocellier, Patrick; Serruys, Yves [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France)

    2015-03-14

    Single and dual-beam ion irradiations of silicon carbide (SiC) were performed to study possible Synergetic effects between Nuclear (S{sub n}) and Electronic (S{sub e}) Energy Losses. Results obtained combining Rutherford backscattering in channeling conditions, Raman spectroscopy, and transmission electron microscopy techniques show that dual-beam irradiation of SiC induces a dramatic change in the final sample microstructure with a substantial decrease of radiation damage as compared to single-beam irradiation. Actually, a defective layer containing dislocations is formed upon dual-beam irradiation (S{sub n} and S{sub e}), whereas single low-energy irradiation (S{sub n} alone) or even sequential (S{sub n} + S{sub e}) irradiations lead to full amorphization. The healing process is ascribed to the electronic excitation arising from the electronic energy loss of swift ions. These results shed new light on the long-standing puzzling problem of the existence of a possible synergy between S{sub n} and S{sub e} in ion-irradiation experiments. This work is interesting for both fundamental understanding of the ion-solid interactions and technological applications in the nuclear industry where recovery S{sub n}/S{sub e} effects may preserve the integrity of nuclear devices.

  9. Electron spin resonance investigations on polycarbonate irradiated with U ions

    Energy Technology Data Exchange (ETDEWEB)

    Chipara, M.I.; Reyes-Romero, J

    2001-12-01

    Electron spin resonance investigations on polycarbonate irradiated with uranium ions are reported. The dependence of the resonance line parameters (line intensity, line width, double integral) on penetration depth and dose is studied. The nature of free radicals induced in polycarbonate by the incident ions is discussed in relation with the track structure. The presence of severe exchange interactions among free radicals is noticed.

  10. Ductility loss of ion-irradiated zircaloy-2 in iodine

    International Nuclear Information System (INIS)

    Shimada, M.; Terasawa, M.; Yamamoto, S.; Kamei, H.; Koizumi, K.

    1981-01-01

    An ion bombardment simulation technique for neutron irradiation was applied to 'thick' materials to study the effect of radiation damage on the ductility change in Zircaloy-2 in an iodine environment. Specimens were prepared from actual cladding tubes and, prior to the irradiation, they were heat-treated in vacuo at 450, 580, and 700/degree/C for 2 h. Irradiation was performed by 52-MeV alpha particles up to the 0.32 displacements per atom (dpa) at 340/degree/C. Ductility loss begins to appear after 0.03 dpa irradiation, both in iodine and argon gas environments. The iodine presence resulted in ductility reduction, compared with the argon result in all irradiation dose ranges examined. The stress applied during irradiation caused ductility loss to commence at lower dosage than in the case of stress-free irradiation. These results are discussed in relation to the existing stress corrosion cracking models

  11. Ion irradiation effect on metallic condensate adhesion to glass

    International Nuclear Information System (INIS)

    Kovalenko, V.V.; Upit, G.P.

    1984-01-01

    The ion irradiation effect on metallic condensate adhesion to glass is investigated. It has been found that in case of indium ion deposition the condensate adhesion to glass cleavages being in contact with atmosphere grows up to the level corresponding to a juvenile surface while in case of argon ion irradiation - exceeds it. It is shown that the observed adhesion growth is determined mainly by the surfwce modification comparising charge accumulation on surface, destruction of a subsurface layer and an interlayer formation in the condensate-substrate interface. The role of these factors in the course of various metals deposition is considered

  12. Disintegration of C60 by Xe ion irradiation

    International Nuclear Information System (INIS)

    Kalish, R.; Samoiloff, A.; Hoffman, A.; Uzan-Saguy, C.

    1993-01-01

    The Changes in resistivity of fullerene (C 60 ) films subject to 320 keV Xe ion irradiation are investigated as a function of ion dose. From a comparison of this dependence with similar data on other Xe irradiated C containing insulating materials and with data on C implanted fused quartz, it is concluded that upon ion impact C 60 clusters completely disintegrate. This disintegration releases about 60 C atoms which disperse amongst the remaining intact C 60 spheres giving rise to hopping conductivity between isolated C atoms. 16 refs., 3 figs

  13. Precipitation in Ni-Si during electron and ion irradiation

    Science.gov (United States)

    Lucas, G. E.; Zama, T.; Ishino, S.

    1986-11-01

    This study was undertaken to further investigate how the nature of the irradiation condition affects precipitation in a dilute Ni-Si system. Transmission electron microscopy (TEM) discs of a solution annealed Ni alloy containing 5 at% Si were irradiated with 400 keV Ar + ions, 200 keV He + ions and 1 MeV electrons at average displacement rates in the range 2 × 10 -5dpa/s to 2 × 10 -3dpa/s at temperatures in the range 25°C to 450°C. Samples irradiated with electrons were observed in situ in an HVEM, while ion irradiated specimens were examined in a TEM after irradiation. Precipitation of Ni 3Si was detected by the appearance of superlattice spots in the electron diffraction patterns. It was found that as the mass of the irradiating species increased, the lower bound temperature at which Ni 3Si precipitation was first observed increased. For electron irradiation, the lower bound temperature at 2 × 10 -3dpa/s was ˜125°C, whereas for 400 keV Ar + irradiation at a similar average displacement rate the lower boundary was approximately 325°C. This suggests that cascade disordering competes with radiation induced solute segregation.

  14. Precipitation in Ni-Si during electron and ion irradiation

    International Nuclear Information System (INIS)

    Lucas, G.E.; Zama, T.; Ishino, S.

    1986-01-01

    This study was undertaken to further investigate how the nature of the irradiation condition affects precipitation in a dilute Ni-Si system. Transmission electron microscopy (TEM) discs of a solution annealed Ni alloy containing 5 at% Si were irradiated with 400 keV Ar + ions, 200 keV He + ions and 1 MeV electrons at average displacement rates in the range 2x10 -5 dpa/s to 2x10 -3 dpa/s at temperatures in the range 25 0 C to 450 0 C. Samples irradiated with electrons were observed in situ in an HVEM, while ion irradiated specimens were examined in a TEM after irradiation. Precipitation of Ni 3 Si was detected by the appearance of superlattice spots in the electron diffraction patterns. It was found that as the mass of the irradiating species increased, the lower bound temperature at which Ni 3 Si precipitation was first observed increased. For electron irradiation, the lower bound temperature at 2x10 -3 dpa/s was ∝125 0 C, whereas for 400 keV Ar + irradiation at a similar average displacement rate the lower boundary was approximately 325 0 C. This suggests that cascade disordering competes with radiation induced solute segregation. (orig.)

  15. Corrosion characteristics of Hastelloy N alloy after He+ ion irradiation

    International Nuclear Information System (INIS)

    Lin Jianbo; Yu Xiaohan; Li Aiguo; He Shangming; Cao Xingzhong; Wang Baoyi; Li Zhuoxin

    2014-01-01

    With the goal of understanding the invalidation problem of irradiated Hastelloy N alloy under the condition of intense irradiation and severe corrosion, the corrosion behavior of the alloy after He + ion irradiation was investigated in molten fluoride salt at 700 °C for 500 h. The virgin samples were irradiated by 4.5 MeV He + ions at room temperature. First, the virgin and irradiated samples were studied using positron annihilation lifetime spectroscopy (PALS) to analyze the influence of irradiation dose on the vacancies. The PALS results showed that He + ion irradiation changed the size and concentration of the vacancies which seriously affected the corrosion resistance of the alloy. Second, the corroded samples were analyzed using synchrotron radiation micro-focused X-ray fluorescence, which indicated that the corrosion was mainly due to the dealloying of alloying element Cr in the matrix. Results from weight-loss measurement showed that the corrosion generally correlated with the irradiation dose of the alloy. (author)

  16. Characteristic effects of heavy ion irradiation on the rat brain

    International Nuclear Information System (INIS)

    Sun, X.Z.; Takahashi, S.; Kubota, Y.; Yoshida, S.; Takeda, H.; Zhang, R.; Fukui, Y.

    2005-01-01

    Heavy ion irradiation has the feature to administer a large radiation dose in the vicinity of the endpoint in the beam range, and its irradiation system and biophysical characteristics are different from ordinary irradiation instruments like X- or gamma-rays. Using this special feature, heavy ion irradiation has been applied for cancer treatment. The safety and efficacy of heavy ion irradiator have been demonstrated to a great extent. For instance, brain tumors treated by heavy-ion beams became smaller or disappearance. However, fundamental research related to such clinical phenotypes and their underlying mechanisms are little known. In order to clarify characteristic effects of heavy ion irradiation on the brain, we developed an experimental system for irradiating a restricted region of the rat brain using heavy ion beams. The characteristics of the heavy ion beams, histological, behavioral and elemental changes were studied in the rat following heavy ion irradiation. Adult male Sprague-Dawley rats, aged 12 weeks and weighing 260-340 g (Shizuoka Laboratory Animal Center, Hamamatsu, Japan) were used. Rats were deeply anesthetized 10-15 minutes before irradiation with ketamine (40 mg/kg) and xylazine (10 mg/kg), immobilized in a specifically designed jig, and irradiated with 290 MeV/nucleon charged carbon beams in a dorsal-to ventral direction, The left cerebral hemispheres of the brain were irradiated at doses of 100 Gy charged carbon particles. The depth-dose distribution of the heavy ion beams was modified to make a spread-out bragg peak of 5 mm wide with a range modulator. The characteristics of the heavy-ion beams (field and depth of the heavy-ion beams) were examined by a measuring paraffin section of rat brain at different thickness. That extensive necrosis was observed between 2.5 mm and 7.5 mm depth from the surface of the rat head, suggesting a relatively high dose and uniform dose was delivered among designed depths and the spread-out bragg peak used here

  17. Alternative approaches to electronic damage by ion-beam irradiation: Exciton models

    Energy Technology Data Exchange (ETDEWEB)

    Agullo-Lopez, F.; Munoz-Martin, A.; Zucchiatti, A. [Centro de Micro-Analisis de Materiales, Universidad Autonoma de Madrid, 28049, Madrid (Spain); Climent-Font, A. [Centro de Micro-Analisis de Materiales, Universidad Autonoma de Madrid, 28049, Madrid (Spain); Departamento de Fisica Aplicada, Universidad Autonoma de Madrid, 28049, Madrid (Spain)

    2016-11-15

    The paper briefly describes the main features of the damage produced by swift heavy ion (SHI) irradiation. After a short revision of the widely used thermal spike concept, it focuses on cumulative mechanisms of track formation which are alternative to those based on lattice melting (thermal spike models). These cumulative mechanisms rely on the production of point defects around the ion trajectory, and their accumulation up to a final lattice collapse or amorphization. As to the formation of point defects, the paper considers those mechanisms relying on direct local conversion of the excitation energy into atomic displacements (exciton models). A particular attention is given to processes based on the non-radiative recombination of excitons that have become self-trapped as a consequence of a strong electron-phonon interaction (STEs). These mechanisms, although operative under purely ionizing radiation in some dielectric materials, have been rarely invoked, so far, to discuss SHI damage. They are discussed in this paper together with relevant examples to materials such as Cu{sub 3}N, alkali halides, SiO{sub 2}, and LiNbO{sub 3}. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Irradiation of graphene field effect transistors with highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, P.; Kozubek, R.; Madauß, L.; Sonntag, J.; Lorke, A.; Schleberger, M., E-mail: marika.schleberger@uni-due.de

    2016-09-01

    In this work, graphene field-effect transistors are used to detect defects due to irradiation with slow, highly charged ions. In order to avoid contamination effects, a dedicated ultra-high vacuum set up has been designed and installed for the in situ cleaning and electrical characterization of graphene field-effect transistors during irradiation. To investigate the electrical and structural modifications of irradiated graphene field-effect transistors, their transfer characteristics as well as the corresponding Raman spectra are analyzed as a function of ion fluence for two different charge states. The irradiation experiments show a decreasing mobility with increasing fluences. The mobility reduction scales with the potential energy of the ions. In comparison to Raman spectroscopy, the transport properties of graphene show an extremely high sensitivity with respect to ion irradiation: a significant drop of the mobility is observed already at fluences below 15 ions/μm{sup 2}, which is more than one order of magnitude lower than what is required for Raman spectroscopy.

  19. 160 MeV Ni{sup 12+} ion irradiation effects on the structural, optical and electrical properties of spherical polypyrrole nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, J.; Kumar, A., E-mail: ask@tezu.ernet.in

    2014-01-01

    Highlights: • Upon SHI irradiation the average diameters of PPy nanoparticles increases. • Crystallinity of PPy nanoparticles increases with increasing ion fluence. • IR active vibrational bands have different cross sections for SHI irradiation. • Upon SHI irradiation optical band gap energy of PPy nanoparticles decreases. • Upon SHI irradiation thermal stability of PPy nanoparticles increases. -- Abstract: In this study we report 160 MeV Ni{sup 12+} swift heavy ion irradiation induced enhancement in the structural, optical and electrical properties of spherical polypyrrole (PPy) nanoparticles. High resolution transmission electron microscope results show that the pristine PPy nanoparticles have an average diameter of 11 nm while upon irradiation the average diameter increases to 18 nm at the highest ion fluence of 1 × 10{sup 12} ions/cm{sup 2}. X-ray diffraction studies show an enhancement of crystallinity and average crystallite size of PPy nanoparticles with increasing fluence. Studies of Fourier transform infrared spectra suggest the structural modifications of different functional groups upon irradiation. It also reveals that different functional groups have different sensitivity to irradiation. The infrared active N–H vibrational band at 3695 cm{sup −1} is more sensitive to irradiation with a formation cross-section of 5.77 × 10{sup −13} cm{sup 2} and effective radius of 4.28 nm. The UV–visible absorption spectra of PPy nanoparticles show that the absorption band undergoes a red shift with increasing fluence. Moreover upon irradiation the optical band gap energy decreases and Urbach’s energy increases with fluence. Thermo-gravimetric analysis studies suggest that upon irradiation the thermal stability of PPy nanoparticles increases which may be attributed to their enhanced crystallinity. Current–voltage characteristics of PPy nanoparticles exhibit non-Ohmic, symmetric behavior which increases with fluence.

  20. High energy argon ion irradiations of polycrystalline iron

    International Nuclear Information System (INIS)

    Dunlop, A.; Lesueur, D.; Lorenzelli, N.; Boulanger, L.

    1986-09-01

    We present here the results of our recent irradiations of polycrystalline iron targets with very energetic (1.76 GeV) Ar ions. The targets consist of piles of thin iron samples, the total thickness of each target being somewhat greater than the theoretical range (450 μm) of the ions. We can thus separate the phenomena which occur at different average energies of the ions and study during the slowing-down process: the different types of induced nuclear reactions. They allow us to determine the experimental range of the ions, the defect profiles in the targets, the structure of the displacement cascades (electron microscopy) and their stability

  1. Irradiation effects of Ar cluster ion beams on Si substrates

    International Nuclear Information System (INIS)

    Ishii, Masahiro; Sugahara, Gaku; Takaoka, G.H.; Yamada, Isao

    1993-01-01

    Gas-cluster ion beams can be applied to new surface modification techniques such as surface cleaning, low damage sputtering and shallow junction formation. The effects of energetic Ar cluster impacts on solid surface were studied for cluster energies of 10-30keV. Irradiation effects were studied by RBS. For Si(111) substrates, irradiated with Ar ≥500 clusters to a dose of 1x10 15 ion/cm 2 at acceleration voltage 15kV, 2x10 14 atoms/cm 2 implanted Ar atoms were detected. In this case, the energy per cluster atom was smaller than 30eV; at this energy, no significant implantation occurs in the case of monomer ions. Ar cluster implantation into Si substrates occurred due to the high energy density irradiation. (author)

  2. Construction plan of ion irradiation facility in JAERI

    International Nuclear Information System (INIS)

    Tanaka, Ryuichi

    1987-01-01

    The Takasaki Radiation Chemistry Research Establishment of Japan Atomic Energy Research Institute (JAERI) started the construction of an ion irradiation facility to apply ion beam to the research and development of radiation resistant materials for severe environment, the research on biotechnology and new functional materials. This project was planned as ion beam irradiation becomes an effective means for the research on fundamental physics and advanced technology, and the national guideline recently emphasizes the basic and pioneering field in research and development. This facility comprises an AVF cyclotron with an ECR ion source (maximum proton energy: 90 MeV), a 3 MV tandem accelerator, a 3 MV single end type Van de Graaf accelerator and a 400 kV ion implanter. In this report, the present status of planning the accelerators and the facility to be constructed, the outline of research plan, the features of the accelerators, and the beam characteristics are described. In this project, the research items are divided into the materials for space environment, the materials for nuclear fusion reactors, biotechnology, new functional materials, and ion beam technology. The ion beams required for the facility are microbeam, pulsed beam, multiple beam, neutron beam and an expanded irradiation field. (Kako, I.)

  3. Constructing carbon nanotube junctions by Ar ion beam irradiation

    International Nuclear Information System (INIS)

    Ishaq, Ahmad; Ni Zhichun; Yan Long; Gong Jinlong; Zhu Dezhang

    2010-01-01

    Carbon nanotubes (CNTs) irradiated by Ar ion beams at elevated temperature were studied. The irradiation-induced defects in CNTs are greatly reduced by elevated temperature. Moreover, the two types of CNT junctions, the crossing junction and the parallel junction, were formed. And the CNT networks may be fabricated by the two types of CNT junctions. The formation process and the corresponding mechanism of CNT networks are discussed.

  4. New cultivar produced by heavy-ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kanaya, Takeshi; Miyazaki, Kiyoshi; Suzuki, Kenichi; Iwaki, Kazunari [Suntory Flowers Ltd., Higashiomi, Shiga (Japan); Ichida, Hiroyuki; Hayashi, Yoriko; Saito, Hiroyuki; Ryuto, Hiromichi; Fukunishi, Nobuhisa; Abe, Tomoko [RIKEN, Nishina Center, Wako, Saitama (Japan)

    2007-03-15

    The RIKEN accelerator research facility (RARF) is the one of the biggest facilities to accelerate heavy ions in all over the world since 1986. We started our trials in plant breeding since 1993. Soon we found that the ion beam is highly effective in the cause of mutagenesis of tobacco embryos during the fertilization without damage to other plant tissue. RIKEN and Suntory Flowers Ltd. have jointly developed some new ornamental varieties of Verbena and Petunia using ion-beam irradiation. We already put 5 new flower cultivars on the market in Japan, USA, Canada and EU since 2002. We report here a new variety of Torenia obtained by ion-beam irradiation. (author)

  5. Modification of bamboo surface by irradiation of ion beams

    International Nuclear Information System (INIS)

    Wada, M.; Nishigaito, S.; Flauta, R.; Kasuya, T.

    2003-01-01

    When beams of hydrogen ions, He + and Ar + were irradiated onto bamboo surface, gas release of hydrogen, water, carbon monoxide and carbon dioxide were enhanced. Time evolution of the gas emission showed two peaks corresponding to release of adsorbed gas from the surface by sputtering, and thermal desorption caused by the beam heating. The difference in etched depths between parenchyma lignin and vascular bundles was measured by bombarding bamboo surface with the ion beams in the direction parallel to the vascular bundles. For He + and Ar + , parenchyma lignin was etched more rapidly than vascular bundles, but the difference in etched depth decreased at a larger dose. In the case of hydrogen ion bombardment, vascular bundles were etched faster than parenchyma lignin and the difference in etched depth increased almost in proportion to the dose. The wettability of outer surface of bamboo was improved most effectively by irradiation of a hydrogen ion beam

  6. Ion irradiation damage in ilmenite under cryogenic conditions

    International Nuclear Information System (INIS)

    Mitchell, J.N.; Yu, N.; Devanathan, R.; Sickafus, K.E.; Nastasi, M.A.

    1996-01-01

    A natural single crystal of ilmenite was irradiated at 100 K with 200 keV Ar 2+ . Rutherford backscattering spectroscopy and ion channeling with 2 MeV He + ions were used to monitor damage accumulation in the surface region of the implanted crystal. At an irradiation fluence of 1 x 10 15 Ar 2+ cm -2 , considerable near-surface He + ion dechanneling was observed, to the extent that ion yield from a portion of the aligned crystal spectrum reached the yield level of a random spectrum. This observation suggests that the near-surface region of the crystal was amorphized by the implantation. Cross-sectional transmission electron microscopy and electron diffraction on this sample confirmed the presence of a 150 mm thick amorphous layer. These results are compared to similar investigations on geikielite (MgTiO 3 ) and spinel (MgAl 2 O 4 ) to explore factors that may influence radiation damage response in oxides

  7. New cultivar produced by heavy-ion beam irradiation

    International Nuclear Information System (INIS)

    Kanaya, Takeshi; Miyazaki, Kiyoshi; Suzuki, Kenichi; Iwaki, Kazunari; Ichida, Hiroyuki; Hayashi, Yoriko; Saito, Hiroyuki; Ryuto, Hiromichi; Fukunishi, Nobuhisa; Abe, Tomoko

    2007-01-01

    The RIKEN accelerator research facility (RARF) is the one of the biggest facilities to accelerate heavy ions in all over the world since 1986. We started our trials in plant breeding since 1993. Soon we found that the ion beam is highly effective in the cause of mutagenesis of tobacco embryos during the fertilization without damage to other plant tissue. RIKEN and Suntory Flowers Ltd. have jointly developed some new ornamental varieties of Verbena and Petunia using ion-beam irradiation. We already put 5 new flower cultivars on the market in Japan, USA, Canada and EU since 2002. We report here a new variety of Torenia obtained by ion-beam irradiation. (author)

  8. Ion-irradiation-induced defects in bundles of carbon nanotubes

    International Nuclear Information System (INIS)

    Salonen, E.; Krasheninnikov, A.V.; Nordlund, K.

    2002-01-01

    We study the structure and formation yields of atomic-scale defects produced by low-dose Ar ion irradiation in bundles of single-wall carbon nanotubes. For this, we employ empirical potential molecular dynamics and simulate ion impact events over an energy range of 100-1000 eV. We show that the most common defects produced at all energies are vacancies on nanotube walls, which at low temperatures are metastable but long-lived defects. We further calculate the spatial distribution of the defects, which proved to be highly non-uniform. We also show that ion irradiation gives rise to the formations of inter-tube covalent bonds mediated by carbon recoils and nanotube lattice distortions due to dangling bond saturation. The number of inter-tube links, as well as the overall damage, linearly grows with the energy of incident ions

  9. The effect of ion irradiation on inert gas bubble mobility

    International Nuclear Information System (INIS)

    Alexander, D.E.; Birtcher, R.C.

    1991-09-01

    The effect of Al ion irradiation on the mobility of Xe gas bubbles in Al thin films was investigated. Transmission electron microscopy was used to determine bubble diffusivities in films irradiated and/or annealed at 673K, 723K and 773K. Irradiation increased bubble diffusivity by a factor of 2--9 over that due to thermal annealing alone. The Arrhenius behavior and dose rate dependence of bubble diffusivity are consistent with a radiation enhanced diffusion phenomenon affecting a volume diffusion mechanism of bubble transport. 9 refs., 3 figs., 2 tabs

  10. Surface modification of multilayer graphene using Ga ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Quan, E-mail: wangq@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Shao, Ying; Ge, Daohan; Ren, Naifei [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Yang, Qizhi [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State key laboratory of Robotics, Chinese Academy of Sciences, Shengyang 110000 (China)

    2015-04-28

    The effect of Ga ion irradiation intensity on the surface of multilayer graphene was examined. Using Raman spectroscopy, we determined that the irradiation caused defects in the crystal structure of graphene. The density of defects increased with the increase in dwell times. Furthermore, the strain induced by the irradiation changed the crystallite size and the distance between defects. These defects had the effect of doping the multilayer graphene and increasing its work function. The increase in work function was determined using contact potential difference measurements. The surface morphology of the multilayer graphene changed following irradiation as determined by atomic force microscopy. Additionally, the adhesion between the atomic force microscopy tip and sample increased further indicating that the irradiation had caused surface modification, important for devices that incorporate graphene.

  11. Comparison of deuterium retention for ion-irradiated and neutron-irradiated tungsten

    International Nuclear Information System (INIS)

    Oya, Yasuhisa; Kobayashi, Makoto; Okuno, Kenji; Shimada, Masashi; Calderoni, Pattrick; Oda, Takuji; Hara, Masanori; Hatano, Yuji; Watanabe, Hideo

    2014-01-01

    The behavior of D retentions for Fe 2+ irradiated tungsten with the damage of 0.025-3 dpa was compared with that for neutron irradiated tungsten with 0.025 dpa. The D 2 TDS spectra for Fe 2+ irradiated tungsten consisted of two desorption stages at 450 K and 550 K although that for neutron irradiated tungsten was composed of three stages and addition desorption stage was found around 750 K. The desorption rate of major desorption stage at 550 K increased as the number of dpa by Fe 2+ irradiation increased. In addition, the first desorption stage at 450 K was only found for the damaged samples, indicating that the second stage would be based on intrinsic defects or vacancy produced by Fe 2+ irradiation and the first stage should be the accumulation of D in mono vacancy leading to the lower activation energy, where the dislocation loop and vacancy was produced. The third one was only found for the neutron irradiation, showing the D trapping by void or vacancy cluster and the diffusion effect is also contributed due to high FWHM of TDS spectrum. It can be said that the D 2 TDS spectra for Fe 2+ -irradiated tungsten could not represent that for neutron-irradiated one, showing that the deuterium trapping and desorption mechanism for neutron-irradiated tungsten has a difference from that for ion-irradiated one. (author)

  12. Carbon ion irradiation induced surface modification of polypropylene

    International Nuclear Information System (INIS)

    Saha, A.; Chakraborty, V.; Dutta, R.K.; Chintalapudi, S.N.

    2001-01-01

    Polypropylene was irradiated with 12 C ions of 3.6 and 5.4 MeV energies in the fluence range of 5x10 13 -5x10 14 ions/cm 2 using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1-6 μm) were observed, but at higher fluence (1x10 14 ions/cm 2 ) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed

  13. Carbon ion irradiation induced surface modification of polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Saha, A. E-mail: abhijit@alpha.iuc.res.in; Chakraborty, V.; Dutta, R.K.; Chintalapudi, S.N

    2001-12-01

    Polypropylene was irradiated with {sup 12}C ions of 3.6 and 5.4 MeV energies in the fluence range of 5x10{sup 13}-5x10{sup 14} ions/cm{sup 2} using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1-6 {mu}m) were observed, but at higher fluence (1x10{sup 14} ions/cm{sup 2}) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed.

  14. Cell survival in spheroids irradiated with heavy-ion beams

    International Nuclear Information System (INIS)

    Rodriguez, A.; Alpen, E.L.

    1981-01-01

    Biological investigations with accelerated heavy ions have been carried out regularly at the Lawrence Berkeley Laboratory Bevalac for the past four years. Most of the cellular investigations have been conducted on cell monolayer and suspension culture systems. The studies to date suggest that heavy charged particle beams may offer some radiotherapeutic advantages over conventional radiotherapy sources. The advantages are thought to lie primarily in an increased relative biological effectiveness (RBE), a decrease in the oxygen enhancement ratio (OER), and better tissue distribution dose. Experiments reported here were conducted with 400 MeV/amu carbon ions and 425 MeV/amu neon ions, using a rat brain gliosarcoma cell line grown as multicellular spheroids. Studies have been carried out with x-rays and high-energy carbon and neon ion beams. These studies evaluate high-LET (linear energy transfer) cell survival in terms of RBE and the possible contributions of intercellular communication. Comparisons were made of the post-irradiation survival characteristics for cells irradiated as multicellular spheroids (approximately 100 μm and 300 μm diameters) and for cells irradiated in suspension. These comparisons were made between 225-kVp x-rays, 400 MeV/amu carbon ions, and 425 MeV/amu neon ions

  15. Effect of heavy ion irradiation on sucrose radical production

    International Nuclear Information System (INIS)

    Nakagawa, Kouichi; Sato, Yukio

    2004-01-01

    We investigated sucrose radicals produced by heavy-ion irradiation with various LETs (linear energy transfer) and the possibility for a sucrose ESR (electron spin resonance) dosimeter. The obtained spectral pattern was the same as that for helium (He) ions, carbon (C) ions, neon (Ne) ions, argon (Ar) ions, and iron (Fe) ions. Identical spectra were measured after one year, but the initial intensities decreased by a few percent when the samples were kept in ESR tubes with the caps at ambient temperature. The total spin concentration obtained by heavy-ion irradiation had a linear relation with the absorbed dose, and correlated logarithmically with the LET. Qualitative ESR analyses showed that the production of sucrose radicals depended on both the particle identity and the LET at the same dose. The production of spin concentration by He ions was the most sensitive to LET. Empirical relations between the LET and the spin yield for various particles imply that the LET at a certain dose can be estimated by the spin concentration. (authors)

  16. Quantitative approach to relate dielectric constant studies with TSDC studies of 50 MeV Si ion irradiated kapton-H polymide

    International Nuclear Information System (INIS)

    Quamara, J.K.; Garg, Maneesha; Sridharbabu, Y.; Prabhavathi, T.

    2003-01-01

    Temperature and frequency dependent dielectric behaviour has been investigated for pristine and swift heavy ion irradiated (Si ion, 50 MeV energy) kapton-H polyimide in the temperature range of 30 to 250 deg C at frequencies 120 Hz, 1 kHz, 10 kHz and 100 kHz respectively. The dielectric relaxation behaviour of the same samples was also studied using thermally stimulated discharge current (TSDC) technique. A quantitative approach is developed using a well-known Clausius Mossotti equation to relate the TSDC findings to the dielectric constant studies. An overall increase in the dielectric constant of the irradiated samples are also in conformity to the TSDC findings. (author)

  17. Correlation between surface phonon mode and luminescence in nanocrystalline CdS thin films: An effect of ion beam irradiation

    International Nuclear Information System (INIS)

    Kumar, Pragati; Agarwal, Avinash; Saxena, Nupur; Singh, Fouran; Gupta, Vinay

    2014-01-01

    The influence of swift heavy ion irradiation (SHII) on surface phonon mode (SPM) and green emission in nanocrystalline CdS thin films grown by chemical bath deposition is studied. The SHII of nanocrystalline CdS thin films is carried out using 70 MeV Ni ions. The micro Raman analysis shows that asymmetry and broadening in fundamental longitudinal optical (LO) phonon mode increases systematically with increasing ion fluence. To analyze the role of phonon confinement, spatial correlation model (SCM) is fitted to the experimental data. The observed deviation of SCM to the experimental data is further investigated by fitting the micro Raman spectra using two Lorentzian line shapes. It is found that two Lorentzian functions (LFs) provide better fitting than SCM fitting and facilitate to identify the contribution of SPM in the observed distortion of LO mode. The behavior of SPM as a function of ion fluence is studied to correlate the observed asymmetry (Γ a /Γ b ) and full width at half maximum of LO phonon mode and to understand the SHII induced enhancement of SPM. The ion beam induced interstitial and surface state defects in thin films, as observed by photoluminescence (PL) spectroscopy studies, may be the underlying reason for enhancement in SPM. PL studies also show enhancement in green luminescence with increase in ion fluence. PL analysis reveals that the variation in population density of surface state defects after SHII is similar to that of SPM. The correlation between SPM and luminescence and their dependence on ion irradiation fluence is explained with the help of thermal spike model.

  18. Correlation between surface phonon mode and luminescence in nanocrystalline CdS thin films: An effect of ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pragati, E-mail: pkumar.phy@gmail.com; Agarwal, Avinash [Department of Physics, Bareilly College, Bareilly 243 005, Uttar Pradesh (India); Saxena, Nupur; Singh, Fouran [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India)

    2014-07-28

    The influence of swift heavy ion irradiation (SHII) on surface phonon mode (SPM) and green emission in nanocrystalline CdS thin films grown by chemical bath deposition is studied. The SHII of nanocrystalline CdS thin films is carried out using 70 MeV Ni ions. The micro Raman analysis shows that asymmetry and broadening in fundamental longitudinal optical (LO) phonon mode increases systematically with increasing ion fluence. To analyze the role of phonon confinement, spatial correlation model (SCM) is fitted to the experimental data. The observed deviation of SCM to the experimental data is further investigated by fitting the micro Raman spectra using two Lorentzian line shapes. It is found that two Lorentzian functions (LFs) provide better fitting than SCM fitting and facilitate to identify the contribution of SPM in the observed distortion of LO mode. The behavior of SPM as a function of ion fluence is studied to correlate the observed asymmetry (Γ{sub a}/Γ{sub b}) and full width at half maximum of LO phonon mode and to understand the SHII induced enhancement of SPM. The ion beam induced interstitial and surface state defects in thin films, as observed by photoluminescence (PL) spectroscopy studies, may be the underlying reason for enhancement in SPM. PL studies also show enhancement in green luminescence with increase in ion fluence. PL analysis reveals that the variation in population density of surface state defects after SHII is similar to that of SPM. The correlation between SPM and luminescence and their dependence on ion irradiation fluence is explained with the help of thermal spike model.

  19. Effects of ion beam irradiation on Oncidium lanceanum

    International Nuclear Information System (INIS)

    Zaiton Ahmad; Affrida Abu Hassan; Nurul Aliaa Idris; Mohd Nazir Basiran

    2006-01-01

    Protocorm-like bodies (PLBs) of an orchid (Oncidium lanceanum) were irradiated using 220 MeV 12 C 5+ ion, accelerated by AVF cyclotron at JAEA, Japan in 2005. Five different doses were applied to the PLBs; 0, 1.0, 2.0, 6.0 and 12.0 Gy. Following irradiation, these PLBs were maintained in cultures for germination and multiplication. Irradiation effects on growth and seedling regeneration patterns as well as morphological characteristics of the in vitro cultures were monitored and recorded. In general, average fresh weights of the irradiated PLBs increased progressively by irradiating the explants at 1.0, 2.0 and reached the maximum at 6.0 Gy. The figure however dropped when the explants were irradiated at 12 Gy. Surprisingly, although the highest average fresh weight was recorded on PLBs irradiated at 6.0 Gy, most of these PLBs were not able to regenerate into complete shoots. On average, only 21 seedlings were successfully regenerated from each gram of these PLBs. The highest shoot regeneration was recorded on cultures irradiated at 2.0 Gy in which 102 seedlings were obtained from one gram of the PLBs. Most of the regenerated seedlings have been transferred to glass house for morphological screening. Molecular analysis showed the presence of DNA polymorphisms among the seedlings from different doses

  20. Hydrogen formation under gamma and heavy ions irradiation of geopolymers

    International Nuclear Information System (INIS)

    Chupin, F.; Dannoux-Papin, A.; D'Espinose de Lacaillerie, J.B.; Ngono Ravache, Y.

    2015-01-01

    This study examines the behavior under irradiation of geo-polymer which is not yet well known and attempts to highlight the importance of water radiolysis. For their use as embedding matrices, stability under ionizing radiation as well as low hydrogen gas released must be demonstrated. Different formulations of geo-polymers have been irradiated either with γ-rays ( 60 Co sources) or 75 MeV 36 Ar ions beams and the production of hydrogen released has been quantified. This paper presents the results of gas analysis in order to identify important structural parameters that influence confined water radiolysis. Indeed, a correlation between pore size, water content on one side, and the hydrogen production radiolytic yield (G(H 2 )) on the other side, has been demonstrated. For the 75 MeV 36 Ar ions irradiation, the effect of porosity has not been well emphasized. For both, the results have revealed the water content influence. (authors)

  1. Effects of ion beam irradiation on Oncidium lanceanum orchids

    International Nuclear Information System (INIS)

    Zaiton Ahmad; Affrida Abu Hassan

    2006-01-01

    Protocorm-like bodies (PLBs) of an orchid (Oncidium lanceanum) were irradiated using 220 MeV 12 C 5+ ions, accelerated by AVF cyclotron at JAEA, Japan in 2005. Five different doses were applied to the PLBs; 0, 1.0, 2.0, 6.0 and 12.0 Gy. Following irradiation, these PLBs were maintained in cultures for germination and multiplication. Irradiation effects on growth and seedling regeneration patterns as well as molecular characteristics of the in vitro cultures were monitored and recorded. In general, average fresh weights of the irradiated PLBs increased progressively by irradiating the explants at 1.0, 2.0 and reached the maximum at 6.0 Gy. The figure however dropped when the explants were irradiated at 12 Gy. Surprisingly, although the highest average fresh weight was recorded on PLBs irradiated at 6.0 Gy, most of these PLBs were not able to regenerate into complete shoots. On average, after 4 months of irradiation, only 21 seedlings were successfully regenerated from each gram of these PLBs. The highest shoot regeneration was recorded on cultures irradiated at 2.0 Gy in which 102 seedlings were obtained from one gram of the PLBs. Some morphological changes were seen on in vitro plantlets derived from PLBs irradiated at doses of 1.0 and 2.0 Gy. Most of the regenerated seedlings have been transferred to glasshouse for further morphological selection. Molecular analysis showed the presence of DNA polymorphisms among the seedlings from different doses of irradiation. (Author)

  2. Evaluation of Ion Irradiation Behavior of ODS Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Sung; Kim, Min Chul; Hong, Jun Hwa; Han, Chang Hee; Chang, Young Mun; Bae, Chang Soo; Bae, Yoon Young; Chang, Moon Hee

    2006-08-15

    FM steel (Grade 92) and ODS alloy(MA956) specimens were ion irradiated with 122 MeV Ne ions. Irradiation temperatures were about 450 and 550 .deg. C and the peak dose was 1, 5, and 10 dpa. Cross-sectional TEM samples were prepared by the electrolytic Ni-plating after pre-treatment of the irradiated specimens. Irradiation cavities in FM steel and ODS alloy specimens were not much different in size; about 20 nm in diameter in both specimens irradiated at around 450 .deg. C. However, the size distribution of cavities in FM steel specimens was broader than that in ODS alloy specimen, indicating that the cavity growth probably via coalescence). It was noticeable that the location and the preferential growth of the cavities in FM steel specimens: cavities on the PAGB (prior austenite grain boundary) was significantly larger than those within the grains. This could be an important issue for the mechanical properties, especially high temperature creep, fracture toughness, and so on. The dependency of the dose threshold and swelling on the ratio of the inert gas concentration/dpa was analysed for the various irradiation source, including He, Ne, Fe/He, and fast neutron, and the empirical correlation was established.

  3. Evaluation of Ion Irradiation Behavior of ODS Alloys

    International Nuclear Information System (INIS)

    Jang, Jin Sung; Kim, Min Chul; Hong, Jun Hwa; Han, Chang Hee; Chang, Young Mun; Bae, Chang Soo; Bae, Yoon Young; Chang, Moon Hee

    2006-08-01

    FM steel (Grade 92) and ODS alloy(MA956) specimens were ion irradiated with 122 MeV Ne ions. Irradiation temperatures were about 450 and 550 .deg. C and the peak dose was 1, 5, and 10 dpa. Cross-sectional TEM samples were prepared by the electrolytic Ni-plating after pre-treatment of the irradiated specimens. Irradiation cavities in FM steel and ODS alloy specimens were not much different in size; about 20 nm in diameter in both specimens irradiated at around 450 .deg. C. However, the size distribution of cavities in FM steel specimens was broader than that in ODS alloy specimen, indicating that the cavity growth probably via coalescence). It was noticeable that the location and the preferential growth of the cavities in FM steel specimens: cavities on the PAGB (prior austenite grain boundary) was significantly larger than those within the grains. This could be an important issue for the mechanical properties, especially high temperature creep, fracture toughness, and so on. The dependency of the dose threshold and swelling on the ratio of the inert gas concentration/dpa was analysed for the various irradiation source, including He, Ne, Fe/He, and fast neutron, and the empirical correlation was established

  4. Effect of 100 MeV Ag{sup +7} ion irradiation on the bulk and surface magnetic properties of Co–Fe–Si thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hysen, T., E-mail: hysenthomas@gmail.com [Department of Physics, Cochin University of Science and Technology, Cochin 682 022, Kerala (India); Department of Physics, Christian College, Chengannur, Kerala 689 122 (India); Geetha, P. [Department of Physics, Cochin University of Science and Technology, Cochin 682 022, Kerala (India); Al-Harthi, Salim; Al-Omari, I.A. [Department of Physics, College of Science, Sultan Qaboos University, Al Khod 123 (Oman); Lisha, R. [Department of Physics, Cochin University of Science and Technology, Cochin 682 022, Kerala (India); Ramanujan, R.V. [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639 798 (Singapore); Sakthikumar, D. [Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe (Japan); Avasthi, D.K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Anantharaman, M.R., E-mail: mra@cusat.ac.in [Department of Physics, Cochin University of Science and Technology, Cochin 682 022, Kerala (India)

    2014-12-15

    Thin films of Co–Fe–Si were vacuum evaporated on pre-cleaned float glass substrates employing thermal evaporation. The films were subsequently irradiated with 100 MeV Ag{sup +7} ions at fluences of 1×10{sup 11}, 1×10{sup 12} and 1×10{sup 13} ions/cm{sup 2}. The pristine and irradiated samples were subjected to surface analysis using Atomic Force Microscopy (AFM), Vibrating Sample Magnetometry (VSM) and Magneto Optic Kerr Effect (MOKE) measurements. The as deposited film has a root mean square roughness (Rq) of 8.9 nm and an average roughness of (Ra) 5.6 nm. Irradiation of the as deposited films with 100 MeV Ag{sup 7+} ions modifies the surface morphology. Irradiating with ions at fluences of 1×10{sup 11} ions/cm{sup 2} smoothens the mesoscopic hill-like structures, and then, at 1×10{sup 12} ions/cm{sup 2} new surface structures are created. When the fluence is further increased to 1×10{sup 13} ions/cm{sup 2} an increase in the surface roughness is observed. The MOKE loop of as prepared film indicated a squareness ratio of 0.62. As the film is irradiated with fluences of 1×10{sup 11} ions/cm{sup 2}, 1×10{sup 12} ions/cm{sup 2} and 1×10{sup 13} ions/cm{sup 2} the squareness ratio changes to 0.76, 0.8 and 0.86 respectively. This enhancement in squareness ratio towards 1 is a typical feature when the exchange interaction starts to dominates the inherent anisotropies in the system. The variation in surface magnetisation is explained based on the variations in surface roughness with swift heavy ion (SHI) irradiation. - Highlights: • We have irradiated thermally evaporated Co–Fe–Si thin films on glass substrate with 100 MeV Ag{sup +7} ions using the 15 UD Pelletron Accelerator at IUAC, New Delhi, India. • Surface morphology and magnetic characteristics of the films can be altered with ion irradiation. • It was observed that the variation in surface magnetic properties correlates well with the changes in surface morphology, further reiterating the

  5. Deuterium ion irradiation induced blister formation and destruction

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jaemin; Kim, Nam-Kyun; Kim, Hyun-Su; Jin, Younggil; Roh, Ki-Baek; Kim, Gon-Ho, E-mail: ghkim@snu.ac.kr

    2016-11-01

    Highlights: • The areal number density of blisters on the grain with (1 1 1) plane orientation increased with increasing ion fluence. • No more blisters were created above the temperature about 900 K due to high thermal mobility of ions and inactivity of traps. • The destruction of blister at the boundary induced by sputtering is proposed. • The blisters were destructed at the position about the boundary by high sputtering yield of oblique incident ions and thin thickness due to plastic deformation at the boundary. - Abstract: The blisters formation and destruction induced by the deuterium ions on a polycrystalline tungsten were investigated with varying irradiation deuterium ion fluence from 3.04 × 10{sup 23} to 1.84 × 10{sup 25} D m{sup −2} s{sup −1} and an fixed irradiated ion energy of 100 eV in an electron cyclotron resonance plasma source, which was similar to the far-scrape off layer region in the nuclear fusion reactors. Target temperature was monitored during the irradiation. Most of blisters formed easily on the grain with (1 1 1) plane orientation which had about 250 nm in diameter. In addition, the areal number density of blisters increased with increasing the ion fluence under the surface temperature reaching to about 900 K. When the fluence exceeded 4.6 × 10{sup 24} D m{sup −2}, the areal number density of the blister decreased. It could be explained that the destruction of the blister was initiated by erosion at the boundary region where the thickness of blister lid was thin and the sputtering yield was high by oblique incident ions, resulting in remaining the lid open, e.g., un-eroded center dome. It is possible to work as a tungsten dust formation from the plasma facing divertor material at far-SOL region of fusion reactor.

  6. LET effects of high energy ion beam irradiation on polysilanes

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Shu; Kanzaki, Kenichi; Tagawa, Seiichi; Yoshida, Yoichi [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research; Kudoh, Hisaaki; Sugimoto, Masaki; Sasuga, Tsuneo; Seguchi, Tadao; Shibata, Hiromi

    1997-03-01

    Thin films of poly(di-n-hexylsilane) were irradiated with 2-20 MeV H{sup +} and He{sup +} ion beams. The beams caused heterogeneous reactions of crosslinking and main chain scission in the films. The relative efficiency of the crosslinking was drastically changed in comparison with that of main chain scission. The anomalous change in the molecular weight distribution was analyzed with increasing irradiation fluence, and the ion beam induced reaction radius; track radius was determined for the radiation sources by the function of molecular weight dispersion. Obtained values were 59{+-}15 A and 14{+-}6 A for 2 MeV He{sup +} and 20 MeV H{sup +} ion beams respectively. (author)

  7. Effects on focused ion beam irradiation on MOS transistors

    International Nuclear Information System (INIS)

    Campbell, A.N.; Peterson, K.A.; Fleetwood, D.M.; Soden, J.M.

    1997-01-01

    The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 μm minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga + focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated

  8. Ion irradiation effects on tensile properties of carbon fibres

    International Nuclear Information System (INIS)

    Kurumada, A.; Ishihara, M.; Baba, S.; Aihara, J.

    2004-01-01

    Carbon/carbon composite materials have high thermal conductivity and excellent mechanical properties at high temperatures. They have been used as structural materials at high temperatures in fission and experimental fusion reactors. The changes in the microstructures and the mechanical properties due to irradiation damage must be measured for the safety design and the life assessment of the materials. The purpose of this study is to obtain a basic knowledge of the development of new carbon composite materials having high thermal conductivity and excellent resistance to irradiation damage. Five kinds of carbon fibres were selected, including a vapour growth carbon fibre (VGCF; K1100X), a polyacrylonitrile-based fibre (PAN; M55JB by Toray Corp.), two meso-phase pitch-based fibres (YS-15-60S and YS-70-60S by Nippon Graphite Fiber Corp.) and a pitch-based fibre (K13C2U by Mitsubishi Chemical Co.). They were irradiated by high-energy carbon, nickel and argon ions. Irradiation damages in the carbon fibres are expected to be uniform across the cross-section, as the diameters of the carbon fibres are about 20 μm and are sufficiently smaller than the ranges of ions. The cross-sectional areas increased due to ion irradiation, with the exception of the K1100X of VGCF. One of the reasons for the increases is the swelling of carbon basal planes due to lattice defects in the graphite interlayer. The tensile strengths and the Young's moduli decreased due to ion irradiation except for the K1100X of VGCF and the YS-15-60S of meso-phase pitch-based fibres. One of the reasons for the decreases is thought to be that the microstructures of carbon fibres are damaged in the axial direction, as ions were irradiated vertically with respect to the longitudinal direction of carbon fibres. The results of this study indicate that the VGCF and the meso-phase pitch-based carbon fibres could be useful as reinforcement fibres of new carbon composite materials having high thermal conductivity and

  9. Kr ion irradiation study of the depleted-uranium alloys

    Science.gov (United States)

    Gan, J.; Keiser, D. D.; Miller, B. D.; Kirk, M. A.; Rest, J.; Allen, T. R.; Wachs, D. M.

    2010-12-01

    Fuel development for the reduced enrichment research and test reactor (RERTR) program is tasked with the development of new low enrichment uranium nuclear fuels that can be employed to replace existing high enrichment uranium fuels currently used in some research reactors throughout the world. For dispersion type fuels, radiation stability of the fuel-cladding interaction product has a strong impact on fuel performance. Three depleted-uranium alloys are cast for the radiation stability studies of the fuel-cladding interaction product using Kr ion irradiation to investigate radiation damage from fission products. SEM analysis indicates the presence of the phases of interest: U(Al, Si) 3, (U, Mo)(Al, Si) 3, UMo 2Al 20, U 6Mo 4Al 43 and UAl 4. Irradiations of TEM disc samples were conducted with 500 keV Kr ions at 200 °C to ion doses up to 2.5 × 10 19 ions/m 2 (˜10 dpa) with an Kr ion flux of 10 16 ions/m 2/s (˜4.0 × 10 -3 dpa/s). Microstructural evolution of the phases relevant to fuel-cladding interaction products was investigated using transmission electron microscopy.

  10. Kr ion irradiation study of the depleted-uranium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gan, J., E-mail: Jian.Gan@inl.go [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Keiser, D.D. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Miller, B.D. [University of Wisconsin, 1500 Engineering Drive, Madison, WI 53706 (United States); Kirk, M.A.; Rest, J. [Argonne National Laboratory, 9700 South Cass Ave., Argonne, IL 60439 (United States); Allen, T.R. [University of Wisconsin, 1500 Engineering Drive, Madison, WI 53706 (United States); Wachs, D.M. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2010-12-01

    Fuel development for the reduced enrichment research and test reactor (RERTR) program is tasked with the development of new low enrichment uranium nuclear fuels that can be employed to replace existing high enrichment uranium fuels currently used in some research reactors throughout the world. For dispersion type fuels, radiation stability of the fuel-cladding interaction product has a strong impact on fuel performance. Three depleted-uranium alloys are cast for the radiation stability studies of the fuel-cladding interaction product using Kr ion irradiation to investigate radiation damage from fission products. SEM analysis indicates the presence of the phases of interest: U(Al, Si){sub 3}, (U, Mo)(Al, Si){sub 3}, UMo{sub 2}Al{sub 20}, U{sub 6}Mo{sub 4}Al{sub 43} and UAl{sub 4}. Irradiations of TEM disc samples were conducted with 500 keV Kr ions at 200 {sup o}C to ion doses up to 2.5 x 10{sup 19} ions/m{sup 2} ({approx}10 dpa) with an Kr ion flux of 10{sup 16} ions/m{sup 2}/s ({approx}4.0 x 10{sup -3} dpa/s). Microstructural evolution of the phases relevant to fuel-cladding interaction products was investigated using transmission electron microscopy.

  11. Damage studies on tungsten due to helium ion irradiation

    International Nuclear Information System (INIS)

    Dutta, N.J.; Buzarbaruah, N.; Mohanty, S.R.

    2014-01-01

    Highlights: • Used plasma focus helium ion source to study radiation induced damage on tungsten. • Surface analyses confirm formation of micro-crack, bubbles, blisters, pinholes, etc. • XRD patterns confirm development of compressive stress due to thermal load. • Reduction in hardness value is observed in the case of exposed sample. - Abstract: Energetic and high fluence helium ions emitted in a plasma focus device have been used successfully to study the radiation induced damage on tungsten. The reference and irradiated samples were characterized by optical microscopy, field emission scanning electron microscopy, X-ray diffraction and by hardness testers. The micrographs of the irradiated samples at lower magnification show uniform mesh of cracks of micrometer width. However at higher magnification, various types of crystalline defects such as voids, pinholes, bubbles, blisters and microcracks are distinctly noticed. The prominent peaks in X-ray diffraction spectrum of irradiated samples are seen shifted toward higher Bragg angles, thus indicating accumulation of compressive stress due to the heat load delivered by helium ions. A marginal reduction in hardness of the irradiated sample is also noticed

  12. Nanostructure evolution in ODS steels under ion irradiation

    Directory of Open Access Journals (Sweden)

    S. Rogozhkin

    2016-12-01

    In this work, we carried out atom probe tomography (APT and transmission electron microscopy (TEM studies of three different ODS steels produced by mechanical alloying: ODS Eurofer, 13.5Cr ODS and 13.5Cr-0.3Ti ODS. These materials were investigated after irradiation with Fe (5.6MeV or Ti (4.8MeV ions up to 1015ion/cm2 and part of them up to 3×1015ion/cm2. In all cases, areas for TEM investigation were cut at a depth of ∼ 1.3µm from the irradiated surface corresponding to the peak of the radiation damage dose. It was shown that after irradiation at RT and at 300°С the number density of oxide particles in all the samples grew up. Meanwhile, the fraction of small particles in the size distribution has increased. APT revealed an essential increase in nanoclusters number and a change of their chemical composition at the same depth. The nanostructure was the most stable in 13.5Cr-0.3Ti ODS irradiated at 300°С: the increase of the fraction of small oxides was minimal and no change of nanocluster chemical composition was detected.

  13. Thermal stability of low dose Ga+ ion irradiated spin valves

    International Nuclear Information System (INIS)

    Qi Xianjin; Wang Yingang; Zhou Guanghong; Li Ziquan

    2009-01-01

    The thermal stability of low dose Ga + ion irradiated spin valves has been investigated and compared with that of the as-prepared ones. The dependences of exchange field, measured using vibrating sample magnetometer at room temperature, on magnetic field sweep rate and time spent at negative saturation of the pinned ferromagnetic layer, and training effect were explored. The training effect is observed on both the irradiated spin valves and the as-prepared ones. The magnetic field sweep rate dependence of the exchange bias field of the irradiated spin valves is nearly the same as that of the as-prepared ones. For the as-prepared structure thermal activation has been observed, which showed that holding the irradiated structure at negative saturation of the pinned ferromagnetic layer for up to 28 hours results in no change in the exchange field. The results indicate that the thermal stability of the ion irradiated spin valves is the same as or even better than the as-prepared ones.

  14. Ion irradiation enhanced crystal nucleation in amorphous Si thin films

    International Nuclear Information System (INIS)

    Im, J.S.; Atwater, H.A.

    1990-01-01

    The nucleation kinetics of the amorphous-to-crystal transition of Si films under 1.5 MeV Xe + irradiation have been investigated by means of in situ transmission electron microscopy in the temperature range T=500--580 degree C. After an incubation period during which negligible nucleation occurs, a constant nucleation rate was observed in steady state, suggesting that homogeneous nucleation occurred. Compared to thermal crystallization, a significant enhancement in the nucleation rate during high-energy ion irradiation (five to seven orders of magnitude) was observed with an apparent activation energy of 3.9±0.75 eV

  15. Ion-irradiated polymer studied by a slow positron beam

    International Nuclear Information System (INIS)

    Kobayashi, Yoshinori; Kojima, Isao; Hishita, Shunichi; Suzuki, Takenori.

    1995-01-01

    Poly (aryl-ether-ether ketone) (PEEK) films were irradiated with 1MeV and 2MeV 0 + ions and the positron annihilation Doppler broadening was measured as a function of the positron energy. The annihilation lines recorded at relatively low positron energies were found to become broader with increasing the irradiation dose, suggesting that positronium (Ps) formation may be inhibited in the damaged regions. A correlation was observed between the Doppler broadening and spin densities determined by electron spin resonance (ESR). (author)

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

    International Nuclear Information System (INIS)

    Kuzmann, E.; Spirov, I.N.

    1984-01-01

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

  17. TL response of Eu activated LiF nanocubes irradiated by 85 MeV carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Salah, Numan, E-mail: nsalah@kau.edu.sa [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alharbi, Najlaa D. [Sciences Faculty for Girls, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Habib, Sami S. [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Lochab, S.P. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-09-01

    Carbon ions were found to be effective for cancer treatment. These heavy ions have a high relative biological effectiveness compared to those of photons. They have higher linear energy transfer and sharper Bragg peak with a very excellent local tumor control. However, the dose of these swift heavy ions needs to be measured with great accuracy. Lithium fluoride (LiF) is a highly sensitive phosphor widely used for radiation dosimetry. In this work Eu activated LiF nanocubes were exposed to 85 MeV C{sup 6+} ion beam and evaluated for their thermoluminescence (TL) response. Pellet forms of this nanomaterial were exposed to these ions in the fluence range 10{sup 9}–10{sup 13} ions/cm{sup 2}. The obtained result shows a prominent TL glow peak at around 320 °C, which is different than that induced by gamma rays. This glow peak exhibits a linear response in the range 10{sup 9}–10{sup 12} ions/cm{sup 2}, corresponding to the equivalent absorbed doses 0.273–273 kGy. The absorbed doses, penetration depths and main energy loss were calculated using TRIM code based on the Monte Carlo simulation. The supralinearity function and stopping power in this nanomaterial were also studied. The modification induced in the glow curve structure as a result of changing irradiation type might be utilized to use LiF:Eu nanocubes as a dosimeter for mixed filed radiations. Moreover, the wide linear response of LiF:Eu nanocubes along with the low fading are another imperative results suggesting that this nanomaterial might be a good candidate for carbon ions dosimetry.

  18. TL response of Eu activated LiF nanocubes irradiated by 85 MeV carbon ions

    International Nuclear Information System (INIS)

    Salah, Numan; Alharbi, Najlaa D.; Habib, Sami S.; Lochab, S.P.

    2015-01-01

    Carbon ions were found to be effective for cancer treatment. These heavy ions have a high relative biological effectiveness compared to those of photons. They have higher linear energy transfer and sharper Bragg peak with a very excellent local tumor control. However, the dose of these swift heavy ions needs to be measured with great accuracy. Lithium fluoride (LiF) is a highly sensitive phosphor widely used for radiation dosimetry. In this work Eu activated LiF nanocubes were exposed to 85 MeV C 6+ ion beam and evaluated for their thermoluminescence (TL) response. Pellet forms of this nanomaterial were exposed to these ions in the fluence range 10 9 –10 13 ions/cm 2 . The obtained result shows a prominent TL glow peak at around 320 °C, which is different than that induced by gamma rays. This glow peak exhibits a linear response in the range 10 9 –10 12 ions/cm 2 , corresponding to the equivalent absorbed doses 0.273–273 kGy. The absorbed doses, penetration depths and main energy loss were calculated using TRIM code based on the Monte Carlo simulation. The supralinearity function and stopping power in this nanomaterial were also studied. The modification induced in the glow curve structure as a result of changing irradiation type might be utilized to use LiF:Eu nanocubes as a dosimeter for mixed filed radiations. Moreover, the wide linear response of LiF:Eu nanocubes along with the low fading are another imperative results suggesting that this nanomaterial might be a good candidate for carbon ions dosimetry

  19. AFM studies on heavy ion irradiated YBCO single crystals

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  20. Mutagenic effects of heavy ion irradiation on rice seeds

    International Nuclear Information System (INIS)

    Xu Xue; Liu Binmei; Zhang Lili; Wu Yuejin

    2012-01-01

    Three varieties of rice seeds were subjected to irradiation using low-energy and medium-energy ions. The damage and mutations induced by the ions were examined. In addition, genetic analysis and gene mapping of spotted leaf (spl) mutants were performed. Low-energy ions had no significant influence on germination, survival or seedling height, except for the survival of Nipponbare. Medium-energy ions had a significant influence on germination and survival but had no significant effect on seedling height. In the low-energy group, among 60,000 M 2 plants, 2823 putative morphological mutants were found, and the mutation frequency was approximately 4.71%. In the medium-energy group, 3132 putative morphological mutants were found, and the mutation frequency was approximately 5.22%. Five spl mutants (spl29–spl33) were obtained by ion irradiation, and the heredity of the spl mutants was stable. The characteristics of the spl mutants were found, by genetic analysis and preliminary mapping, to be controlled by a single recessive gene, and spl30 and spl33 were found to be new lesion-mimic mutants.

  1. Mutagenic effects of heavy ion irradiation on rice seeds

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xue [School of Agronomy, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036 (China); Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering, 350 Shushanhu Road, Hefei 230031 (China); Liu Binmei; Zhang Lili [Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering, 350 Shushanhu Road, Hefei 230031 (China); Wu Yuejin, E-mail: yjwu@ipp.ac.cn [Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering, 350 Shushanhu Road, Hefei 230031 (China)

    2012-11-01

    Three varieties of rice seeds were subjected to irradiation using low-energy and medium-energy ions. The damage and mutations induced by the ions were examined. In addition, genetic analysis and gene mapping of spotted leaf (spl) mutants were performed. Low-energy ions had no significant influence on germination, survival or seedling height, except for the survival of Nipponbare. Medium-energy ions had a significant influence on germination and survival but had no significant effect on seedling height. In the low-energy group, among 60,000 M{sub 2} plants, 2823 putative morphological mutants were found, and the mutation frequency was approximately 4.71%. In the medium-energy group, 3132 putative morphological mutants were found, and the mutation frequency was approximately 5.22%. Five spl mutants (spl29-spl33) were obtained by ion irradiation, and the heredity of the spl mutants was stable. The characteristics of the spl mutants were found, by genetic analysis and preliminary mapping, to be controlled by a single recessive gene, and spl30 and spl33 were found to be new lesion-mimic mutants.

  2. Ion beam irradiation of ceramics at fusion relevant conditions

    International Nuclear Information System (INIS)

    Zinkle, S.J.

    1991-01-01

    Ceramic materials are required at a variety of locations in proposed fusion reactors where significant ionizing and displacive fields may be present. Energetic ion beams are a useful tool for probing the effects of irradiation on the structure and electrical properties of ceramics over a wide range of experimental conditions. The advantages and disadvantages of using ion beams to provide information on anticipated ceramic radiation effects in a fusion reactor environment are discussed. In this paper particular emphasis is placed on microstructural changes and how the high helium generation rates associated with DT fusion neutrons affect cavity swelling

  3. Switching the uniaxial magnetic anisotropy by ion irradiation induced compensation

    Science.gov (United States)

    Yuan, Ye; Amarouche, Teyri; Xu, Chi; Rushforth, Andrew; Böttger, Roman; Edmonds, Kevin; Campion, Richard; Gallagher, Bryan; Helm, Manfred; Jürgen von Bardeleben, Hans; Zhou, Shengqiang

    2018-04-01

    In the present work, the uniaxial magnetic anisotropy of GaMnAsP is modified by helium ion irradiation. According to the micro-magnetic parameters, e.g. resonance fields and anisotropy constants deduced from ferromagnetic resonance measurements, a rotation of the magnetic easy axis from out-of-plane [0 0 1] to in-plane [1 0 0] direction is achieved. From the application point of view, our work presents a novel avenue in modifying the uniaxial magnetic anisotropy in GaMnAsP with the possibility of lateral patterning by using lithography or focused ion beam.

  4. Dose Response of Alanine Detectors Irradiated with Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

    2011-01-01

    Purpose: The dose response of the alanine detector shows a dependence on particle energy and type, when irradiated with ion beams. The purpose of this study is to investigate the response behaviour of the alanine detector in clinical carbon ion beams and compare the results with model predictions......-dose curves deviate from predictions in the peak region, most pronounced at the distal edge of the peak. Conclusions: The used model and its implementation show a good overall agreement for quasi mono energetic measurements. Deviations in depth-dose measurements are mainly attributed to uncertainties...

  5. High ion temperatures from buried layers irradiated with Vulcan Petawatt

    International Nuclear Information System (INIS)

    Karsch, S.; Schreiber, J.; Willingale, L.; Lancaster, K.; Habara, H.; Nilson, P.; Gopal, A.; Wei, M. S.; Stoeckl, C.; Evans, R.; Clarke, R.; Heathcote, R.; Najmudin, Z.; Krushelnick, K.; Neely, D.; Norreys, P. A.

    2005-01-01

    Deuteron acceleration from CH/CD/CH layer targets irradiated with PW laser pulses has been studied using. Thomson parabola spectrometers and neutron TOF spectroscopy. The measured ion and neutron spectra reveal significant MeV deuteron acceleration from the deeply buried CD layer, which scales with the thickness of the overlying CH layer. While the neutron spectra reveal the scaling of the thermal heating with target thickness, the ion spectra indicate the presence of an efficient nonthermal acceleration mechanism inside. the bulk. Possible explanations will be discussed. (Author)

  6. Effective mutagenesis of Arabidopsis by heavy ion beam-irradiation

    International Nuclear Information System (INIS)

    Yamamoto, Y.Y.; Saito, H.; Ryuto, H.; Fukunishi, N.; Yoshida, S.; Abe, T.

    2005-01-01

    Full text: Arabidopsis researches frequently include the genetic approach, so efficient, convenient, and safe methods for mutagenesis are required. Currently, the most popular method for in house mutagenesis is application of EMS. Although this method is very effective, its base substitution-type mutations often gives leaky mutants with residual gene functions, leading some difficulty in understanding the corresponding gene functions. Heavy ion beam generated by accelerators gives highest energy transfer rates among known radiation-based mutagenesis methods including X ray, gamma ray, fast neutron, electron and proton irradiation. This feature is thought to give high frequency of the double strand break of genomic DNA and resultant short deletions, resulting frame shift-type mutations. At RIKEN Accelerator Research Facility (RARF, http://www.rarf.riken.go.jp/index-e.html), we have optimized conditions for effective mutagenesis of Arabidopsis regarding to ion species and irradiation dose, and achieved comparable mutation rates to the method with EMS. (author)

  7. Swift for dummies

    CERN Document Server

    Feiler, Jesse

    2015-01-01

    Get up and running with Swift-swiftly Brimming with expert advice and easy-to-follow instructions,Swift For Dummies shows new and existing programmers how toquickly port existing Objective-C applications into Swift and getinto the swing of the new language like a pro. Designed from theground up to be a simpler programming language, it's never beeneasier to get started creating apps for the iPhone or iPad, orapplications for Mac OS X. Inside the book, you'll find out how to set up Xcode for a newSwift application, use operators, objects, and data types, andcontrol program flow with conditiona

  8. Ion irradiation of AZO thin films for flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Alberti, Alessandra [CNR-IMM, via Strada VIII 5, 95121 Catania (Italy); Mirabella, Salvatore; Ruffino, Francesco [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Terrasi, Antonio, E-mail: antonio.terrasi@ct.infn.it [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy)

    2017-02-01

    Highlights: • Evidence of electrical good quality AZO ultra thin films without thermal annealing. • Evidence of the main role of Oxygen vs. structural parameters in controlling the electrical performances of AZO. • Evidence of the role of the ion irradiation in improving the electrical properties of AZO ultra thin films. • Synthesis of AZO thin films on flexible/plastic substrates with good electrical properties without thermal processes. - Abstract: Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O{sup +} or Ar{sup +} ion beams (30–350 keV, 3 × 10{sup 15}–3 × 10{sup 16} ions/cm{sup 2}) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

  9. Investigation of radiative charging of dielectrics irradiated by ions

    International Nuclear Information System (INIS)

    Dergobuzov, K.A.; Yalovets, A.P.

    1994-01-01

    Within the framework of the Gusel'nikov mathematical model are fulflled numerical investigations of charging dielectrics irradiated with ions and atoms. The model accounts for dynamics of quasi-free charge carriers of each sign with account of processes of dielectrics ionization with a beam, charge recombination and charge drift in an electric fields. The effective mobility of charge carriers is determined with account for its dependence on the dose rate

  10. Using ion irradiation to make high-Tc Josephson junctions

    International Nuclear Information System (INIS)

    Bergeal, N.; Lesueur, J.; Sirena, M.; Faini, G.; Aprili, M.; Contour, J. P.; Leridon, B.

    2007-01-01

    In this article we describe the effect of ion irradiation on high-T c superconductor thin film and its interest for the fabrication of Josephson junctions. In particular, we show that these alternative techniques allow to go beyond most of the limitations encountered in standard junction fabrication methods, both in the case of fundamental and technological purposes. Two different geometries are presented: a planar one using a single high-T c film and a mesa one defined in a trilayer structure

  11. Investigations on carbon cluster formation in heavy ion irradiated polymers

    International Nuclear Information System (INIS)

    Tripathy, S.P.; Mishra, R.; Mawar, A.K.; Dwivedi, K.K.; Khathing, D.T.; Srivastava, A.; Avasthi, D.K.; Ghosh, S.; Fink, D.

    2000-01-01

    In polymers, the carbonaceous clusters are supposed to be responsible for the electrical conductivity. So, the irradiation of organic polymers namely polypropylene (8μ) and polyimide (50μ) by energetic heavy ions 28 Si and 58 Ni produce significant changes in the size of these clusters leading to the corresponding change in the band gap and other electrical properties as revealed by the UV-VIS spectroscopic examinations. (author)

  12. Effect of microstructure on light ion irradiation creep in nickel

    International Nuclear Information System (INIS)

    Henager, C.H. Jr.; Simonen, E.P.; Bradley, E.R.; Stang, R.G.

    1983-01-01

    The concept of inhomogeneous slip or localized deformation is introduced to account for a weak dependence of irradiation creep on initial microstructure. Specimens of pure nickel (Ni) with three different microstructures were irradiated at 473 K with 15-17 MeV deuterons in the Pacific Northwest Laboratory (PNL) light ion irradiation creep apparatus. A dispersed barrier model for Climb-Glide (CG) creep was unable to account for the observed creep rates and creep strains. The weak dependence on microstructure was consistent with the Stress Induced Preferential Absorption (SIPA) creep mechanism but a high stress enhanced bias had to be assumed to account for the creep rates. Also, SIPA was unable to account for the observed creep strains. The CG and SIPA modeling utilized rate theory calculations of point defect fluxes and transmission electron microscopy for sink sizes and densities. (orig.)

  13. [Grain boundary and interface kinetics during ion irradiation

    International Nuclear Information System (INIS)

    Atwater, H.A.

    1991-01-01

    Proposed here is renewed support of a research program focused on interface motion and phase transformation during ion irradiation, with emphasis on elemental semiconductors. Broadly speaking, the aims of this program are to explore defect kinetics in amorphous and crystalline semiconductors, and to relate defect dynamics to interface motion and phase transformations. Over the last three years, we initiated a program under DOE support to explore crystallization and amorphization of elemental semiconductors under irradiation. This research has enabled new insights about the nature of defects in amorphous semiconductors and about microstructural evolution in the early stages of crystallization. In addition, we have demonstrated almost arbitrary control over the relative rates of crystal nucleation and crystal growth in silicon. As a result, the impinged grain microstructure of thin (100 nm) polycrystalline films crystallized under irradiation can be controlled with grain sizes ranging from a few nanometers to several micrometers, which may have interesting technological implications

  14. Effects of microstructure on light ion irradiation creep in nickel

    International Nuclear Information System (INIS)

    Henager, C.H. Jr.; Simonen, E.P.; Bradley, E.R.; Stang, R.G.

    1982-10-01

    The concept of inhomogeneous slip or localized deformation is introduced to account for a weak dependence of irradiation creep on initial microstructure. Specimens of pure Ni with three different microstructures were irradiated at 473 0 K with 15 to 17 MeV deuterons in the PNL light ion irradiation creep apparatus. A dispersed barrier model for climb-glide creep was unable to account for the observed creep rates and creep strains. The weak dependence on microstructure was consistent with the SIPA creep mechanism but a high stress enhanced bias had to be assumed to account for the creep rates. Also, SIPA was unable to account for the observed creep strains. The modeling utilized rate theory calculations of point defect fluxes and transmission electron microscopy for sink sizes and densities

  15. Evidence for an ultrafast breakdown of the BeO band structure due to swift argon and xenon ions.

    Science.gov (United States)

    Schiwietz, G; Czerski, K; Roth, M; Grande, P L; Koteski, V; Staufenbiel, F

    2010-10-29

    Auger-electron spectra associated with Be atoms in the pure metal lattice and in the stoichiometric oxide have been investigated for different incident charged particles. For fast incident electrons, for Ar7+ and Ar15+ ions as well as Xe15+ and Xe31+ ions at velocities of 6% to 10% the speed of light, there are strong differences in the corresponding spectral distributions of Be-K Auger lines. These differences are related to changes in the local electronic band structure of BeO on a femtosecond time scale after the passage of highly charged heavy ions.

  16. Investigations of Atomic Transport Induced by Heavy Ion Irradiation

    Science.gov (United States)

    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.).

  17. Positron Annihilation Study of Ion-irradiated Si

    International Nuclear Information System (INIS)

    Shin, Jung Ki; Kwon, Jun Hyun; Lee, Jong Yong

    2009-01-01

    Structural parts like a spaceship, satellite and solar cell are composed of metal alloy or semiconductor materials. Especially, Si is used as a primary candidate alloy. But, manned and robotic missions to the Earth's moon and Mars are exposed to a continuous flux of Galactic Cosmic Rays (GCR) and occasional, but intense, fluxes of Solar Energetic Particles. These natural radiations impose hazards to manned exploration. Irradiation of cosmic particle induces various changes in the mechanical and physical properties of device steels. It is, therefore, important to investigate radiation damage to the component materials in semiconductor. The evolution of radiation-induced defects leads to degradation of the mechanical properties. One of them includes irradiation embrittlement, which can cause a loss of ductility and further increase the probability of a brittle fracture. It can be more dangerous in the space. Positron annihilation lifetime spectroscopy(PALS) have been applied to investigate the production of vacancy-type defects for Ion-irradiated Si wafer penetrated by H, He, O and Fe ions. Then, we carried out a comparison with an un-irradiated Si wafer

  18. Effect of Ion Irradiation in Cadmium Niobate Pyrochlores

    International Nuclear Information System (INIS)

    Jiang, Weilin; Weber, William J.; Thevuthasan, Suntharampillai; Boatner, Lynn A.

    2003-01-01

    Irradiation experiments have been performed for cadmium niobate pyrochlore (CdNb2O) single crystals at both 150 and 300 K using 1.0 MeV Au ions over fluences ranging from 0.01 to 0.10 ions/nm. In-situ 3.0 MeV He Rutherford backscattering spectrometry along the -axial channeling direction (RBS/C) has been applied to study the damage states ranging from small defect concentrations to a fully amorphous state. Results show that the crystal can be readily amorphized under the irradiation conditions. Room-temperature recovery of the defects produced at 150 K has been observed, while the defects produced at 300 K are thermally stable at room temperature. Results also indicate that the RBS/C analysis used in this study induced negligible damage in the near-surface regime. In addition, irradiation at and below room temperature using He and C3 ions leads to surface exfoliation at the corresponding damage peaks

  19. Elastic wave from fast heavy ion irradiation on solids

    CERN Document Server

    Kambara, T; Kanai, Y; Kojima, T M; Nanai, Y; Yoneda, A; Yamazaki, Y

    2002-01-01

    To study the time-dependent mechanical effects of fast heavy ion irradiations, we have irradiated various solids by a short-bunch beam of 95 MeV/u Ar ions and observed elastic waves generated in the bulk. The irradiated targets were square-shaped plates of poly-crystals of metals (Al and Cu), invar alloy, ceramic (Al sub 2 O sub 3), fused silica (SiO sub 2) and single crystals of KC1 and LiF with a thickness of 10 mm. The beam was incident perpendicular to the surface and all ions were stopped in the target. Two piezo-electric ultrasonic sensors were attached to the surface of the target and detected the elastic waves. The elastic waveforms as well as the time structure and intensity of the beam bunch were recorded for each shot of a beam bunch. The sensor placed opposite to the beam spot recorded a clear waveform of the longitudinal wave across the material, except for the invar and fused silica targets. From its propagation time along with the sound velocity and the thickness of the target, the depth of the...

  20. Ion irradiation of AZO thin films for flexible electronics

    Science.gov (United States)

    Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana; Alberti, Alessandra; Mirabella, Salvatore; Ruffino, Francesco; Terrasi, Antonio

    2017-02-01

    Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O+ or Ar+ ion beams (30-350 keV, 3 × 1015-3 × 1016 ions/cm2) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

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

    International Nuclear Information System (INIS)

    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

  2. Synchrotron Topographic and Diffractometer Studies of Buried Layered Structures Obtained by Implantation with Swift Heavy Ions in Silicon Single Crystals

    International Nuclear Information System (INIS)

    Wierzchowski, W.; Wieteska, K.; Zymierska, D.; Graeff, W.; Czosnyka, T.; Choinski, J.

    2006-01-01

    A distribution of crystallographic defects and deformation in silicon crystals subjected to deep implantation (20-50 μm) with ions of the energy of a few MeV/amu is studied. Three different buried layered structures (single layer, binary buried structure and triple buried structure) were obtained by implantation of silicon single crystals with 184 MeV argon ions, 29.7 MeV boron ions, and 140 MeV argon ions, each implantation at a fluency of 1x10 14 ions cm -2 . The implanted samples were examined by means of white beam X-ray section and projection topography, monochromatic beam topography and by recording local rocking curves with the beam restricted to 50 x 50 μm 2 . The experiment pointed to a very low level of implantation-induced strain (below 10 -5 ). The white beam Bragg case section experiment revealed a layer producing district black contrast located at a depth of the expected mean ion range. The presence of these buried layered structures in studied silicon crystals strongly affected the fringe pattern caused by curvature of the samples. In case of white beam projection and monochromatic beam topographs the implanted areas were revealed as darker regions with a very tiny grain like structure. One may interpret these results as the effect of considerable heating causing annihilation of point defects and formation of dislocation loops connected with point defect clusters. (author)

  3. Surface modification and adhesion improvement of PTFE film by ion beam irradiation

    International Nuclear Information System (INIS)

    Lee, S.W.; Hong, J.W.; Wye, M.Y.; Kim, J.H.; Kang, H.J.; Lee, Y.S.

    2004-01-01

    The polytetrafluoroethylene (PTFE) surfaces, modified by 1 kV Ar + or O 2 + ion beam irradiation, was investigated with in-situ X-ray photoelectron spectroscopy (XPS), scanning electron micrographs (SEM), atomic force microscopy (AFM) measurements. The surface of PTFE films modified by Ar + ion irradiation was carbonized and the surface roughness increased with increasing ion doses. The surface of PTFE films modified by both Ar + ion in O 2 atmosphere and O 2 + ion irradiation formed the oxygen function group on PTFE surface, and the surface roughness change was relatively small. The adhesion improvement in Ar + ion irradiated PTFE surface is attributed to mechanical interlocking due to the surface roughness and -CF-radical, but that in Ar + ion irradiation in an O 2 atmosphere was contributed by the C-O complex and -CF-radical with mechanical interlocking. The C-O complex and -CF-radical in O 2 + ion irradiated surface contributed to the adhesion

  4. Ion irradiation to simulate neutron irradiation in model graphites: Consequences for nuclear graphite

    Science.gov (United States)

    Galy, N.; Toulhoat, N.; Moncoffre, N.; Pipon, Y.; Bérerd, N.; Ammar, M. R.; Simon, P.; Deldicque, D.; Sainsot, P.

    2017-10-01

    Due to its excellent moderator and reflector qualities, graphite was used in CO2-cooled nuclear reactors such as UNGG (Uranium Naturel-Graphite-Gaz). Neutron irradiation of graphite resulted in the production of 14C which is a key issue radionuclide for the management of the irradiated graphite waste. In order to elucidate the impact of neutron irradiation on 14C behavior, we carried out a systematic investigation of irradiation and its synergistic effects with temperature in Highly Oriented Pyrolitic Graphite (HOPG) model graphite used to simulate the coke grains of nuclear graphite. We used 13C implantation in order to simulate 14C displaced from its original structural site through recoil. The collision of the impinging neutrons with the graphite matrix carbon atoms induces mainly ballistic damage. However, a part of the recoil carbon atom energy is also transferred to the graphite lattice through electronic excitation. The effects of the different irradiation regimes in synergy with temperature were simulated using ion irradiation by varying Sn(nuclear)/Se(electronic) stopping power. Thus, the samples were irradiated with different ions of different energies. The structure modifications were followed by High Resolution Transmission Electron Microscopy (HRTEM) and Raman microspectrometry. The results show that temperature generally counteracts the disordering effects of irradiation but the achieved reordering level strongly depends on the initial structural state of the graphite matrix. Thus, extrapolating to reactor conditions, for an initially highly disordered structure, irradiation at reactor temperatures (200 - 500 °C) should induce almost no change of the initial structure. On the contrary, when the structure is initially less disordered, there should be a "zoning" of the reordering: In "cold" high flux irradiated zones where the ballistic damage is important, the structure should be poorly reordered; In "hot" low flux irradiated zones where the ballistic

  5. Si-nanoparticle synthesis using ion implantation and MeV ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chulapakorn, T.; Wolff, M.; Primetzhofer, D.; Possnert, G. [Uppsala University, Department of Physics and Astronomy, P.O. Box 516, 751 20 Uppsala (Sweden); Sychugov, I.; Suvanam, S.S.; Linnros, J. [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box Electrum 229, 164 40 Kista (Sweden); Hallen, A. [Uppsala University, Department of Physics and Astronomy, P.O. Box 516, 751 20 Uppsala (Sweden); Royal Institute of Technology, School of Information and Communication Technology, P.O. Box Electrum 229, 164 40 Kista (Sweden)

    2015-12-15

    A dielectric matrix with embedded Si-nanoparticles may show strong luminescence depending on nanoparticles size, surface properties, Si-excess concentration and matrix type. Ion implantation of Si ions with energies of a few tens to hundreds of keV in a SiO{sub 2} matrix followed by thermal annealing was identified as a powerful method to form such nanoparticles. The aim of the present work is to optimize the synthesis of Si-nanoparticles produced by ion implantation in SiO{sub 2} by employing MeV ion irradiation as an additional annealing process. The luminescence properties are measured by spectrally resolved photoluminescence including PL lifetime measurement, while X-ray reflectometry, atomic force microscopy and ion beam analysis are used to characterize the nanoparticle formation process. The results show that the samples implanted at 20%-Si excess atomic concentration display the highest luminescence and that irradiation of 36 MeV {sup 127}I ions affects the luminosity in terms of wavelength and intensity. It is also demonstrated that the nanoparticle luminescence lifetime decreases as a function of irradiation fluence. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Etching behavior of poly (vinylidene fluoride) thin films irradiated with ion beams. Effect of irradiated ions and pretreatment

    International Nuclear Information System (INIS)

    Yamaki, Tetsuya; Rohani, Rosiah; Koshikawa, Hiroshi; Takahashi, Shuichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Voss, Kay-Obbe; Neumann, Reinhard

    2008-01-01

    Poly (vinylidene fluoride) thin films irradiated with four kinds of ion beams were exposed to a 9M KOH aqueous solution after their storage in air for 30 or 90 days at different temperatures. According to the conductometry, the heating at 120degC was found to enhance the etch rate in the latent track without changing that in the bulk, thereby enabling us to obtain very high etching sensitivity for the preparation of nano-sized through-pores. The formation of hydroperoxides during this pretreatment should facilitate the introduction of the etching agent to improve etchability. Additionally, the irradiation of higher-LET ions, causing each track to contain more activated sites (like radicals), was preferable to achieve high sensitivity of the etching. (author)

  7. Ion irradiation damage in ilmenite at 100 K

    International Nuclear Information System (INIS)

    Mitchell, J.N.; Yu, N.; Devanathan, R.; Sickafus, K.E.; Nastasi, M.A.

    1997-01-01

    A natural single crystal of ilmenite (FeTiO 3 ) was irradiated at 100 K with 200 keV Ar 2+ . Rutherford backscattering spectroscopy and ion channeling with MeV He + ions were used to monitor damage accumulation in the surface region of the implanted crystal. At an irradiation fluence of 1 x 10 15 Ar 2+ cm -2 , considerable near-surface He + ion dechanneling was observed, to the extent that ion yield from a portion of the aligned crystal spectrum reached the yield level of a random spectrum. This observation suggests that the near-surface region of the crystal was amorphized by the implantation. Cross-sectional transmission electron microscopy and electron diffraction on this sample confirmed the presence of a 150 nm thick amorphous layer. These results are compared to similar investigations on geikielite (MgTiO 3 ) and spinel (MgAl 2 O 4 ) to explore factors that may influence radiation damage response in oxides

  8. Ion irradiation damage in ilmenite at 100 K

    Science.gov (United States)

    Mitchell, J.N.; Yu, N.; Devanathan, R.; Sickafus, K.E.; Nastasi, M.A.; Nord, G.L.

    1997-01-01

    A natural single crystal of ilmenite (FeTiO3) was irradiated at 100 K with 200 keV Ar2+. Rutherford backscattering spectroscopy and ion channeling with 2 MeV He+ ions were used to monitor damage accumulation in the surface region of the implanted crystal. At an irradiation fluence of 1 ?? 1015 Ar2+/cm2, considerable near-surface He+ ion dechanneling was observed, to the extent that ion yield from a portion of the aligned crystal spectrum reached the yield level of a random spectrum. This observation suggests that the near-surface region of the crystal was amorphized by the implantation. Cross-sectional transmission electron microscopy and electron diffraction on this sample confirmed the presence of a 150 nm thick amorphous layer. These results are compared to similar investigations on geikielite (MgTiO3) and spinel (MgAl2O4) to explore factors that may influence radiation damage response in oxides.

  9. Nanostructured surface processing by an intense pulsed ion beam irradiation

    International Nuclear Information System (INIS)

    Yatsuzuka, M.; Masuda, T.; Yamasaki, T.; Uchida, H.; Nobuhara, S.; Hashimoto, Y.; Yoshihara, Y.

    1997-01-01

    Metal surface modification by irradiating an intense pulsed ion beam (IPIB) with short pulse width has been studied experimentally. An IPIB irradiation to a target leads to rapid heating above its melting point. After the beam is turned off, the heated region is immediately cooled by thermal conduction at a cooling rate of typically 10 10 K/s. This rapid cooling and resolidification results in generation of nanostructured phase in the top of surface. The typical hydrogen IPIB parameters are 200 kV of energy, 500 A/cm 2 of current density and 70 ns of pulsewidth. The IPIB was irradiated on a pure titanium to generate nanocrystalline phase. The IPIB-irradiated surface was examined with X-ray diffraction, SEM, and HR-TEM. The randomly oriented lattice fringes as well as a halo diffraction pattern are observed in the HR-TEM micrograph of IPIB-irradiated titanium. The average grain size is found to be 32 nanometers

  10. Light ion irradiation for unfavorable soft tissue sarcoma

    International Nuclear Information System (INIS)

    Linstadt, D.; Castro, J.R.; Phillips, T.L.; Petti, P.L.; Collier, J.M.; Daftari, I.; Schoethaler, R.; Rayner, A.

    1990-09-01

    Between 1978 and 1989, 32 patients with unfavorable soft tissue sarcoma underwent light ion (helium, neon) irradiation with curative intent at Lawrence Berkeley Laboratory. The tumors were located in the trunk in 22 patients and head and neck in 10. Macroscopic tumor was present in 22 at the time of irradiation. Two patients had tumors apparently induced by previous therapeutic irradiation. Follow-up times for surviving patients ranged from 4 to 121 months (median 27 months). The overall 3-year actuarial local control rate was 62%; the corresponding survival rate was 50%. The 3-year actuarial control rate for patients irradiated with macroscopic tumors was 48%, while none of the patients with microscopic disease developed local recurrence (100%). The corresponding 3-year actuarial survival rates were 40% (macroscopic) and 78% (microscopic). Patients with retroperitoneal sarcoma did notably well; the local control rate and survival rate were 64% and 62%, respectively. Complications were acceptable; there were no radiation related deaths, while two patients (6%) required operations to correct significant radiation-related injuries. These results appear promising compared to those achieved by low -LET irradiation, and suggest that this technique merits further investigation

  11. Modification of embedded Cu nanoparticles: Ion irradiation at room temperature

    International Nuclear Information System (INIS)

    Johannessen, B.; Kluth, P.; Giulian, R.; Araujo, L.L.; Llewellyn, D.J.; Foran, G.J.; Cookson, D.J.; Ridgway, M.C.

    2007-01-01

    Cu nanoparticles (NPs) with an average diameter of ∼25 A were synthesized in SiO 2 by ion implantation and thermal annealing. Subsequently, the NPs were exposed to ion irradiation at room temperature simultaneously with a bulk Cu reference film. The ion species/energy was varied to achieve different values for the nuclear energy loss. The short-range atomic structure and average NP diameter were measured by means of extended X-ray absorption fine structure spectroscopy and small angle X-ray scattering, respectively. Transmission electron microscopy yielded complementary results. The short-range order of the Cu films remained unchanged consistent with the high regeneration rate of bulk elemental metals. For the NP samples it was found that increasing nuclear energy loss yielded gradual dissolution of NPs. Furthermore, an increased structural disorder was observed for the residual NPs

  12. Reflection properties of hydrogen ions at helium irradiated tungsten surfaces

    International Nuclear Information System (INIS)

    Doi, K; Tawada, Y; Kato, S; Sasao, M; Kenmotsu, T; Wada, M; Lee, H T; Ueda, Y; Tanaka, N; Kisaki, M; Nishiura, M; Matsumoto, Y; Yamaoka, H

    2016-01-01

    Nanostructured W surfaces prepared by He bombardment exhibit characteristic angular distributions of hydrogen ion reflection upon injection of 1 keV H + beam. A magnetic momentum analyzer that can move in the vacuum chamber has measured the angular dependence of the intensity and the energy of reflected ions. Broader angular distributions were observed for He-irradiated tungsten samples compared with that of the intrinsic polycrystalline W. Both intensity and energy of reflected ions decreased in the following order: the polycrystalline W, the He-bubble containing W, and the fuzz W. Classical trajectory Monte Carlo simulations based on Atomic Collision in Amorphous Target code suggests that lower atom density near the surface can make the reflection coefficients lower due to increasing number of collisions. (paper)

  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

    Science.gov (United States)

    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. Origins of ion irradiation-induced Ga nanoparticle motion on GaAs surfaces

    International Nuclear Information System (INIS)

    Kang, M.; Wu, J. H.; Chen, H. Y.; Thornton, K.; Goldman, R. S.; Sofferman, D. L.; Beskin, I.

    2013-01-01

    We have examined the origins of ion irradiation-induced nanoparticle (NP) motion. Focused-ion-beam irradiation of GaAs surfaces induces random walks of Ga NPs, which are biased in the direction opposite to that of ion beam scanning. Although the instantaneous NP velocities are constant, the NP drift velocities are dependent on the off-normal irradiation angle, likely due to a difference in surface non-stoichiometry induced by the irradiation angle dependence of the sputtering yield. It is hypothesized that the random walks are initiated by ion irradiation-induced thermal fluctuations, with biasing driven by anisotropic mass transport

  15. Fractal and multifractal characteristics of swift heavy ion induced self-affine nanostructured BaF{sub 2} thin film surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, R. P.; Mittal, A. K. [Department of Physics, University of Allahabad, Allahabad 211002 (India); Kumar, Manvendra, E-mail: kmanav@gmail.com; Pandey, A. C. [Nanotechnology Application Centre, University of Allahabad, Allahabad 211002 (India)

    2015-08-15

    Fractal and multifractal characteristics of self-affine surfaces of BaF{sub 2} thin films, deposited on crystalline Si 〈1 1 1〉 substrate at room temperature, were studied. Self-affine surfaces were prepared by irradiation of 120 MeV Ag{sup 9+} ions which modified the surface morphology at nanometer scale. The surface morphology of virgin thin film and those irradiated with different ion fluences are characterized by atomic force microscopy technique. The surface roughness (interface width) shows monotonic decrease with ion fluences, while the other parameters, such as lateral correlation length, roughness exponent, and fractal dimension, did not show either monotonic decrease or increase in nature. The self-affine nature of the films is further confirmed by autocorrelation function. The power spectral density of thin films surfaces exhibits inverse power law variation with spatial frequency, suggesting the existence of fractal component in surface morphology. The multifractal detrended fluctuation analysis based on the partition function approach is also performed on virgin and irradiated thin films. It is found that the partition function exhibits the power law behavior with the segment size. Moreover, it is also seen that the scaling exponents vary nonlinearly with the moment, thereby exhibiting the multifractal nature.

  16. Characterization of polymeric films subjected to lithium ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Groenewold, Gary S., E-mail: gary.groenewold@inl.gov [Idaho National Laboratory, 2351 North Boulevard, Idaho Falls, ID 83415-2208 (United States); Cannon, W. Roger; Lessing, Paul A. [Idaho National Laboratory, 2351 North Boulevard, Idaho Falls, ID 83415-2208 (United States); Avci, Recep; Deliorman, Muhammedin; Wolfenden, Mark [Image and Chemical Analysis Laboratory, Montana State University, Bozeman, MT 59717 (United States); Akers, Doug W.; Jewell, J. Keith; Zuck, Larry D. [Idaho National Laboratory, 2351 North Boulevard, Idaho Falls, ID 83415-2208 (United States)

    2013-02-01

    Highlights: ► Polyethylene glycol (PEG) and paraffinic polymers were subjected to Li ion irradiation. ► Small oligomers detected in irradiated PEG by electrospray ionization (ESI) mass spectrometry. ► Radiolytic scission observed in X-ray photoelectron and electrospray ionization mass spectra. ► Radiation modified paraffinics characterized by changes in non-ionic surfactant additives. ► Results suggest that extent of radiolysis, and radiolytic pathways can be inferred. -- Abstract: Two different polymeric materials that are candidate materials for use as binders for mixed uranium–plutonium oxide nuclear fuel pellets were subjected to Li ion beam irradiation, in order to simulate intense alpha irradiation. The materials (a polyethylene glycol 8000 and a microcrystalline wax) were then analyzed using a combination of mass spectrometry (MS) approaches and X-ray photoelectron spectroscopy (XPS). Samples of the irradiated PEG materials were dissolved in H{sub 2}O and then analyzed using electrospray ionization-MS, which showed the formation of a series of small oligomers in addition to intact large PEG oligomers. The small oligomers were likely formed by radiation-induced homolytic scissions of the C–O and C–C bonds, which furnish radical intermediates that react by radical recombination with H{sup ·} and OH{sup ·}. Surface analysis using SIMS revealed a heterogeneous surface that contained not only PEG-derived polymers, but also hydrocarbon-based entities that are likely surface contaminants. XPS of the irradiated PEG samples indicated the emergence of different carbon species, with peak shifts suggesting the presence of sp{sup 2} carbon atoms. Analysis of the paraffinic film using XPS showed the emergence of oxygen on the surface of the sample, and also a broadening and shifting of the C1s peak, demonstrating a change in the chemistry on the surface. The paraffinic film did not dissolve in either H{sub 2}O or a H{sub 2}O–methanol solution, and

  17. Heavy ion irradiation effects of brannerite-type ceramics

    International Nuclear Information System (INIS)

    Lian, J.; Wang, L.M.; Lumpkin, G.R.; Ewing, R.C.

    2002-01-01

    Brannerite, UTi 2 O 6 , occurs in polyphase Ti-based, crystalline ceramics that are under development for plutonium immobilization. In order to investigate radiation effects caused by α-decay events of Pu, a 1 MeV Kr + irradiation on UTi 2 O 6 , ThTi 2 O 6 , CeTi 2 O 6 and a more complex material, composed of Ca-containing brannerite and pyrochlore, was performed over a temperature range of 25-1020 K. The ion irradiation-induced crystalline-to-amorphous transformation was observed in all brannerite samples. The critical amorphization temperatures of the different brannerite compositions are: 970 K, UTi 2 O 6 ; 990 K, ThTi 2 O 6 ; 1020 K, CeTi 2 O 6 . The systematic increase in radiation resistance from Ce-, Th- to U-brannerite is related to the difference of mean atomic mass of A-site cation in the structure. As compared with the pyrochlore structure-type, brannerite phases are more susceptible to ion irradiation-induced amorphization. The effects of structure and chemical compositions on radiation resistance of brannerite-type and pyrochlore-type ceramics are discussed

  18. Microstructural and plasmonic modifications in Ag–TiO2 and Au–TiO2 nanocomposites through ion beam irradiation

    Directory of Open Access Journals (Sweden)

    Venkata Sai Kiran Chakravadhanula

    2014-09-01

    Full Text Available The development of new fabrication techniques of plasmonic nanocomposites with specific properties is an ongoing issue in the plasmonic and nanophotonics community. In this paper we report detailed investigations on the modifications of the microstructural and plasmonic properties of metal–titania nanocomposite films induced by swift heavy ions. Au–TiO2 and Ag–TiO2 nanocomposite thin films with varying metal volume fractions were deposited by co-sputtering and were subsequently irradiated by 100 MeV Ag8+ ions at various ion fluences. The morphology of these nanocomposite thin films before and after ion beam irradiation has been investigated in detail by transmission electron microscopy studies, which showed interesting changes in the titania matrix. Additionally, interesting modifications in the plasmonic absorption behavior for both Au–TiO2 and Ag–TiO2 nanocomposites were observed, which have been discussed in terms of ion beam induced growth of nanoparticles and structural modifications in the titania matrix.

  19. Ion irradiation effect of alumina and its luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Yasushi; Yamamoto, Shunya; Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; My, N T

    1997-03-01

    The luminescence spectra of single crystalline alpha-alumina and ruby which has 0.02% of Cr{sub 2}O{sub 3} as a impurity, induced by 200 keV He{sup +} and Ar{sup +} irradiation were measured at room temperature as a function of irradiation dose. The analysis of the measured spectra showed the existence of three main luminescence features in the wavelength region of 250 to 350 nm, namely anionic color centers, F-center at 411 nm and F{sup +}-center at 330 nm and a band observed around 315 nm. As alpha-alumina was irradiated with He{sup +}, F-center and F{sup +}-center luminescence grew and decayed, but the behaviors of those were different from each other. It seems that a concentration quenching occurred on the F-center luminescence in the dose range above 1x10{sup 14} He/cm{sup 2}. Furthermore, F-center luminescence was strongly suppressed in ruby, compared with that in alumina. On the other hand, the luminescence band around 315 nm appeared only in the early stage of irradiation and did not show its growth part. The dose dependent behavior was similar to that of Cr{sup 3+} emission at 695 nm (R-line) in ruby in both cases of He{sup +} and Ar{sup +} irradiation. Based on the experimental results mentioned above, the processes of defect formation and excitation in alumina in the early stage of ion irradiation will be discussed. (author)

  20. Ion irradiation-induced swelling and hardening effect of Hastelloy N alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, D.H.; Chen, H.C.; Lei, G.H.; Huang, H.F.; Zhang, W.; Wang, C.B. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Yan, L., E-mail: yanlong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Fu, D.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Tang, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2017-06-15

    The volumetric swelling and hardening effect of irradiated Hastelloy N alloy were investigated in this paper. 7 MeV and 1 MeV Xe ions irradiations were performed at room temperature (RT) with irradiation dose ranging from 0.5 to 27 dpa. The volumetric swelling increases with increasing irradiation dose, and reaches up to 3.2% at 27 dpa. And the irradiation induced lattice expansion is also observed. The irradiation induced hardening initiates at low ion dose (≤1dpa) then saturates with higher ion dose. The irradiation induced volumetric swelling may be ascribed to excess atomic volume of defects. The irradiation induced hardening may be explained by the pinning effect where the defects can act as obstacles for the free movement of dislocation lines. And the evolution of the defects' size and number density could be responsible for the saturation of hardness. - Highlights: •Irradiation Swelling: The irradiation induced volumetric swelling increases with ion dose. •Irradiation Hardening: The irradiation hardening initiates below 1 dpa, then saturates with higher ion dose (1–10 dpa). •Irradiation Mechanism: The irradiation phenomena are ascribed to the microstructural evolution of the irradiation defects.

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

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Vacík, Jiří; Hnatowicz, Vladimír; Hernandez, G. M.; Arrelano, H. G.; Alfonta, L.; Kiv, A.

    2017-01-01

    Roč. 398, MAY (2017), s. 21-26 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : etched ion tracks * track radius * polymer * enzyme * diffusion * biosensors Subject RIV: EI - Biotechnology ; Bionics OBOR OECD: Bioremediation, diagnostic biotechnologies (DNA chips and biosensing devices) in environmental management Impact factor: 1.109, year: 2016

  2. Chlorine diffusion in uranium dioxide under heavy ion irradiation

    International Nuclear Information System (INIS)

    Pipon, Y.; Bererd, N.; Moncoffre, N.; Peaucelle, C.; Toulhoat, N.; Jaffrezic, H.; Raimbault, L.; Sainsot, P.; Carlot, G.

    2007-01-01

    The radiation enhanced diffusion of chlorine in UO 2 during heavy ion irradiation is studied. In order to simulate the behaviour of 36 Cl, present as an impurity in UO 2 , 37 Cl has been implanted into the samples (projected range 200 nm). The samples were then irradiated with 63.5 MeV 127 I at two fluxes and two temperatures and the chlorine distribution was analyzed by SIMS. The results show that, during irradiation, the diffusion of the implanted chlorine is enhanced and slightly athermal with respect to pure thermal diffusion. A chlorine gain of 10% accumulating near the surface has been observed at 510 K. This corresponds to the displacement of pristine chlorine from a region of maximum defect concentration. This behaviour and the mean value of the apparent diffusion coefficient found for the implanted chlorine, around 2.5 x 10 -14 cm 2 s -1 , reflect the high mobility of chlorine in UO 2 during irradiation with fission products

  3. Chlorine diffusion in uranium dioxide under heavy ion irradiation

    Science.gov (United States)

    Pipon, Y.; Bérerd, N.; Moncoffre, N.; Peaucelle, C.; Toulhoat, N.; Jaffrézic, H.; Raimbault, L.; Sainsot, P.; Carlot, G.

    2007-04-01

    The radiation enhanced diffusion of chlorine in UO2 during heavy ion irradiation is studied. In order to simulate the behaviour of 36Cl, present as an impurity in UO2, 37Cl has been implanted into the samples (projected range 200 nm). The samples were then irradiated with 63.5 MeV 127I at two fluxes and two temperatures and the chlorine distribution was analyzed by SIMS. The results show that, during irradiation, the diffusion of the implanted chlorine is enhanced and slightly athermal with respect to pure thermal diffusion. A chlorine gain of 10% accumulating near the surface has been observed at 510 K. This corresponds to the displacement of pristine chlorine from a region of maximum defect concentration. This behaviour and the mean value of the apparent diffusion coefficient found for the implanted chlorine, around 2.5 × 10-14 cm2 s-1, reflect the high mobility of chlorine in UO2 during irradiation with fission products.

  4. Deuterium ion irradiation induced precipitation in Fe–Cr alloy: Characterization and effects on irradiation behavior

    International Nuclear Information System (INIS)

    Liu, P.P.; Yu, R.; Zhu, Y.M.; Zhao, M.Z.; Bai, J.W.; Wan, F.R.; Zhan, Q.

    2015-01-01

    Highlights: • A new phase precipitated in Fe–Cr alloy after deuterium ion irradiation at 773 K. • B2 structure was proposed for the Cr-rich new phase. • Strain fields around the precipitate have been measured by GPA. • The precipitate decrease growth rate of dislocation loop under electron irradiation. - Abstract: A new phase was found to precipitate in a Fe–Cr model alloy after 58 keV deuterium ion irradiation at 773 K. The nanoscale radiation-induced precipitate was studied systematically using high resolution transmission electron microscopy (HRTEM), image simulation and in-situ ultrahigh voltage transmission electron microscopy (HVEM). B2 structure is proposed for the new Cr-rich phase, which adopts a cube-on-cube orientation relationship with regard to the Fe matrix. Geometric phase analysis (GPA) was employed to measure the strain fields around the precipitate and this was used to explain its characteristic 1-dimensional elongation along the 〈1 0 0〉 Fe direction. The precipitate was stable under subsequent electron irradiation at different temperatures. We suggest that the precipitate with a high interface-to-volume ratio enhances the radiation resistance of the material. The reason for this is the presence of a large number of interfaces between the precipitate and the matrix, which may greatly reduce the concentration of point defects around the dislocation loops. This leads to a significant decrease in the growth rate

  5. Modification of WS2 nanosheets with controllable layers via oxygen ion irradiation

    Science.gov (United States)

    Song, Honglian; Yu, Xiaofei; Chen, Ming; Qiao, Mei; Wang, Tiejun; Zhang, Jing; Liu, Yong; Liu, Peng; Wang, Xuelin

    2018-05-01

    As one kind of two-dimensional materials, WS2 nanosheets have drawn much attention with different kinds of research methods. Yet ion irradiation method was barely used for WS2 nanosheets. In this paper, the structure, composition and optical band gap (Eg) of the multilayer WS2 films deposited by chemical vapor deposition (CVD) method on sapphire substrates before and after oxygen ion irradiation with different energy and fluences were studied. Precise tailored layer-structures and a controllable optical band gap of WS2 nanosheets were achieved after oxygen ion irradiation. The results shows higher energy oxygen irradiation changed the shape from triangular shaped grains to irregular rectangle shape but did not change 2H-WS2 phase structure. The intensity of E2g1 (Г) and A1g (Г) modes decreased and have small shifts after oxygen ion irradiation. The peak frequency difference between the E2g1 (Г) and A1g (Г) modes (Δω) decreased after oxygen ion irradiation, and this result indicates the number of layers decreased after oxygen ion irradiation. The Eg decreased with the increase of the energy and the fluence of oxygen ions. The number of layers, thickness and optical band gap changed after ion irradiation with different ion fluences and energies. The results proposed a new strategy for precise control of multilayer nanosheets and demonstrated the high applicability of ion irradiation in super-capacitors, field effect transistors and other applications.

  6. Radiolysis of N2-rich astrophysical ice by swift oxygen ions: implication for space weathering of outer solar system bodies.

    Science.gov (United States)

    Vasconcelos, F A; Pilling, S; Rocha, W R M; Rothard, H; Boduch, P

    2017-09-13

    In order to investigate the role of medium mass cosmic rays and energetic solar particles in the processing of N 2 -rich ice on frozen moons and cold objects in the outer solar system, the bombardment of an N 2  : H 2 O : NH 3  : CO 2 (98.2 : 1.5 : 0.2 : 0.1) ice mixture at 16 K employing 15.7 MeV 16 O 5+ was performed. The changes in the ice chemistry were monitored and quantified by Fourier transformed infrared spectroscopy (FTIR). The results indicate the formation of azide radicals (N 3 ), and nitrogen oxides, such as NO, NO 2 , and N 2 O, as well as the production of CO, HNCO, and OCN - . The effective formation and destruction cross-sections are roughly on the order of 10 -12 cm 2 and 10 -13 cm 2 , respectively. From laboratory molecular analyses, we estimated the destruction yields for the parent species and the formation yields for the daughter species. For N 2 , this value was 9.8 × 10 5 molecules per impact of ions, and for the most abundant new species (N 3 ), it was 1.1 × 10 5 molecules per impact of ions. From these yields, an estimation of how many species are destroyed or formed in a given timescale (10 8 years) in icy bodies in the outer solar system was calculated. This work reinforces the idea that such physicochemical processes triggered by cosmic rays, solar wind, and magnetospheric particles (medium-mass ions) in nitrogen-rich ices may play an important role in the formation of molecules (including pre-biotic species precursors such as amino acids and other "CHON" molecules) in very cold astrophysical environments, such as those in the outer region of the solar system (e.g. Titan, Triton, Pluto, and other KBOs).

  7. The Influence of Deformation on the Surface Structure of Silicon Under Irradiation by $^{86}$Kr Ions with Energy 253 MeV

    CERN Document Server

    Vlasukova, L A; Hofmann, A; Komarov, F F; Semina, V K; Yuvchenko, V N

    2006-01-01

    The influence of the previously produced deformation in silicon structure by means of macro-scratch surface covering on the sputtering processes under following irradiation by swift $^{86}$Kr ions is studied. The significant leveling of surface relief of irradiated silicon was observed using atomic force microscopy method (AFM), in particular it takes place for smoothing of micro-scratches produced by mechanical polishing of silicon initial plates. The experimental studies of irradiated surface allowed one to conclude that it is impossible to explain the surface changes only by elastic cascade mechanism as it was calculated using the computer code TRIM-98, because the calculated sputtered layers of silicon at ion fluence $\\Phi_{\\rm Kr} = 1{.}3\\cdot10^{14}$ ion/cm$^{2}$ should be $\\Delta H_{\\rm Sputtering}^{\\rm Kr} = 5{.}5\\cdot10^{-3 }${\\AA}. Correspondingly, the surface changes should be explained by one of mechanisms of inelastic sputtering. The macro-cracks on the surface were observed near the scratches. I...

  8. Activity computer program for calculating ion irradiation activation

    Science.gov (United States)

    Palmer, Ben; Connolly, Brian; Read, Mark

    2017-07-01

    A computer program, Activity, was developed to predict the activity and gamma lines of materials irradiated with an ion beam. It uses the TENDL (Koning and Rochman, 2012) [1] proton reaction cross section database, the Stopping and Range of Ions in Matter (SRIM) (Biersack et al., 2010) code, a Nuclear Data Services (NDS) radioactive decay database (Sonzogni, 2006) [2] and an ENDF gamma decay database (Herman and Chadwick, 2006) [3]. An extended version of Bateman's equation is used to calculate the activity at time t, and this equation is solved analytically, with the option to also solve by numeric inverse Laplace Transform as a failsafe. The program outputs the expected activity and gamma lines of the activated material.

  9. Neovascular glaucoma after helium ion irradiation for uveal melanoma

    International Nuclear Information System (INIS)

    Kim, M.K.; Char, D.H.; Castro, J.L.; Saunders, W.M.; Chen, G.T.; Stone, R.D.

    1986-01-01

    Neovascular glaucoma developed in 22 of 169 uveal melanoma patients treated with helium ion irradiation. Most patients had large melanomas; no eyes containing small melanomas developed anterior segment neovascularization. The mean onset of glaucoma was 14.1 months (range, 7-31 months). The incidence of anterior segment neovascularization increased with radiation dosage; there was an approximately three-fold increase at 80 GyE versus 60 GyE of helium ion radiation (23% vs. 8.5%) (P less than 0.05). Neovascular glaucoma occurred more commonly in larger tumors; the incidence was not affected by tumor location, presence of subretinal fluid, nor rate of tumor regression. Fifty-three percent of patients had some response with intraocular pressures of 21 mmHg or less to a combination of antiglaucoma treatments

  10. Metal ion protection of DNA to fast neutron irradiation

    International Nuclear Information System (INIS)

    Constantinescu, B.; Bugoi, R.; Radulescu, I.; Radu, L.

    1998-01-01

    The most important effects of the ionising radiation are the single and double strand breaks (SSB and DBS), modifications of the DNA bases and deoxyribose, as well as the occurrence of alkali and heat labile sites (revealed as strand breaks after alkaline or thermic treatment of irradiated DNA). The ionising particles can have either direct effects on the DNA constituents or indirect effects, mediated by the OH - radicals, produced by water radiolysis. The occurrence of SSB and DSB in the chromatin DNA strands is supposed to hinder the DNA-dye complex formation. Usually, the dyes present different fluorescence parameters in the two possible states, so one can correlate the lifetime or the quantum yield with the extent of the damage. We took into account the protective effect offered both by histones, which behave as 'scavenger molecules' for OH - radicals and by the high compactness of DNA chromatin. Similar protective effects might be the results of the metallic ion addition which triggers some conformational transitions of the chromatin DNA towards a highly compacted structure. In this paper we present a study of the complexes of fast neutron irradiated chromatin with proflavine. Fluorimetric and time resolved spectroscopic determinations (single photon counting method) of chromatin-Pr complexes were realised. Information regarding the chromatin protein damage were obtained by monitoring the fluorescence of Trp. The chromatin was irradiated (20-100 Gy) with fast neutrons, obtained by the reaction of 13.5 MeV deuterons on a thick beryllium target at the IFIN-HH U-120 Cyclotron. The dose mean lineal energy in water at the point of interest was 50 keV/m and the mean dose rate was 1.5 Gy/min. By fluorescence determinations, changes of the Pr intercalation parameters in fast neutron irradiated chromatin DNA have been observed. Fluorescence techniques provide valuable information on the binding equilibrium by considering the radiation deexcitation of the complex. The

  11. Ion irradiation effects in structural and magnetic properties of Co/Cu multilayers

    International Nuclear Information System (INIS)

    Sakamoto, Isao; Okazaki, Satoshi; Koike, Masaki; Honda, Shigeo

    2012-01-01

    400 keV Ar ion (the Ar ion) and 50 keV He ion (the He ion) irradiations were performed in order to elucidate roles of Co/Cu interfacial structures in physical origins of giant magnetoresistance (GMR) in the [Co (2 nm)/Cu (2 nm)] 30 multilayers (MLs). The magnetoresistance (MR) ratio after the Ar ion irradiation decreases abruptly with increasing Ar ion fluence. On the other hand, the MR ratio after the He ion irradiation decreases slowly with increasing He ion fluence. The Ar ion irradiation induces the decrease in the difference (R max − R sat ) between the maximum resistance (R max ) and the saturated resistance (R sat ) under in-plane magnetic field and the increase in the R sat , although the effect of the He ion irradiation is not remarkable. The decrease in the (R max − R sat ) rather than the increase in the R sat seems to be effective for the decrease in the MR ratios after the Ar ion and the He ion irradiation. The increase in the R sat implies the mixing of Co atoms in Cu layers. The antiferromagnetic coupling fraction (AFF) estimated from the magnetization curves after the Ar ion and the He ion irradiation shows the similar behavior with the MR ratio as a function of ion fluence. Therefore, although the degrees of the irradiation effects by the Ar ion and the He ions are different, we suggest the relation between the GMR and the AFF affected by the ion-induced interfacial structures accompanied with the atomic mixing in the interfacial region.

  12. Single-ion irradiation: physics, technology and applications

    International Nuclear Information System (INIS)

    Ohdomari, Iwao

    2008-01-01

    Among the various radiation effects which involve the study of radiation environments, responses of materials and devices to radiation, radiation testing and radiation hardening of devices and equipment, this review mainly considers the radiation effects induced by alpha particles and other ions used in semiconductor technology on Si crystals and Si devices. We first describe the single-ion microprobe that enables the study of the site dependence of radiation hardness in a semiconductor device. Next, we describe single-ion implantation as a tool for suppressing fluctuation in device function induced by the discrete number and random position of dopant atoms. Finally, we describe the common features associated with both 'probing' and 'modification' in terms of the nature and behaviour of defect clusters induced by single-ion irradiation. A special feature of the review is that the radiation effects discussed here are induced by 'single' particles, and not by particle beams. Although there is a great amount of accumulated data on radiation effects, they are discussed in the conventional terms of 'dose' or 'fluence,' whose unit is cm -2 . Therefore, this review provides complementary information on radiation effects. (topical review)

  13. Physico-chemical changes in heavy ions irradiated polymer foils by differential scanning calorimetry

    International Nuclear Information System (INIS)

    Ciesla, K.; Trautmann, Ch.; Vansant, E.F.

    1994-01-01

    The sample of commercial PETP (Hostaphan) and very heavy ions irradiated products were investigated by differential scanning calorimetry in nitrogen flow. Irradiation were performed with Dy ions of 13 MeV/u with fluences 5 x 10 10 ions/cm 2 . Differences were observed in melting behaviour of unirradiated and irradiated foils. The influence of irradiation conditions on the results was noticed. Moreover the samples of polyimide (Kapton) and polycarbonate (Macrofol) irradiated in similar conditions were examined by DSC. The DSC traces have been compared with those of unirradiated reference samples. (author). 8 refs, 5 figs

  14. Enhanced defects recombination in ion irradiated SiC

    International Nuclear Information System (INIS)

    Izzo, G.; Litrico, G.; Grassia, F.; Calcagno, L.; Foti, G.

    2010-01-01

    Point defects induced in SiC by ion irradiation show a recombination at temperatures as low as 320 K and this process is enhanced after running current density ranging from 80 to 120 A/cm 2 . Ion irradiation induces in SiC the formation of different defect levels and low-temperature annealing changes their concentration. Some levels (S 0 , S x and S 2 ) show a recombination and simultaneously a new level (S 1 ) is formed. An enhanced recombination of defects is besides observed after running current in the diode at room temperature. The carriers introduction reduces the S 2 trap concentration, while the remaining levels are not modified. The recombination is negligible up to a current density of 50 A/cm 2 and increases at higher current density. The enhanced recombination of the S 2 trap occurs at 300 K, which otherwise requires a 400 K annealing temperature. The process can be related to the electron-hole recombination at the associated defect.

  15. Amorphisation of boron carbide under slow heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gosset, D., E-mail: Dominique.gosset@cea.fr [CEA Saclay, DEN, DANS, DMN, SRMA, LA2M, Université Paris-Saclay, 91191, Gif/Yvette (France); Miro, S. [CEA Saclay, DEN, DANS, DMN, SRMP, Laboratoire JANNUS, Université Paris-Saclay, 91191, Gif/Yvette (France); Doriot, S. [CEA Saclay, DEN, DANS, DMN, SRMA, LA2M, Université Paris-Saclay, 91191, Gif/Yvette (France); Moncoffre, N. [CNRS/IN2P3/IPNL, 69622, Villeurbanne (France)

    2016-08-01

    Boron carbide B{sub 4}C is widely used as a neutron absorber in nuclear plants. Most of the post-irradiation examinations have shown that the structure of the material remains crystalline, in spite of very high atomic displacement rates. Here, we have irradiated B{sub 4}C samples with 4 MeV Au ions with different fluences at room temperature. Transmission electron microscopy (TEM) and Raman spectroscopy have been performed. The Raman analyses show a high structural disorder at low fluence, around 10{sup −2} displacements per atoms (dpa). However, the TEM observations show that the material remains crystalline up to a few dpa. At high fluence, small amorphous areas a few nanometers large appear in the damaged zone but the long range order is preserved. Moreover, the size and density of the amorphous zones do not significantly grow when the damage increases. On the other hand, full amorphisation is observed in the implanted zone at a Au concentration of about 0.0005. It can be inferred from those results that short range and long range damages arise at highly different fluences, that heavy ions implantation has drastic effects on the structure stability and that in this material self-healing mechanisms are active in the damaged zone.

  16. Amorphization, morphological instability and crystallization of krypton ion irradiated germanium

    International Nuclear Information System (INIS)

    Wang, L.M.; Birtcher, R.C.

    1991-01-01

    Krypton ion irradiation of crystalline Ge and subsequent thermal annealing were both carried out with in situ transmission electron microscopy observations. The temperature dependence of the amorphization dose, effect of foil thickness, morphological changes during continuous irradiation of the amorphous state as well as the effect of implanted gas have been determined. The dose of 1.5 MeV Kr required for amorphization increases with increasing temperature. At a fixed temperature, the amorphization dose is higher for thicker regions of the specimen. Continuous irradiation of amorphous Ge at room temperature results in a high density of small cavities which grow with increasing dose. Cavities do not coalesce during growth but develop into irregular-shaped holes that eventually transform the amorphous Ge into a sponge-like material. Formation of the spongy structure is independent of Kr implantation. The crystallization temperature and the morphology of recrystallized Ge depend on the Kr + dose. Voids are expelled from recrystallized Ge, while the sponge-like structure is retained after crystallization. (author)

  17. Data acquisition system for light-ion irradiation creep experiment

    International Nuclear Information System (INIS)

    Hendrick, P.L.; Whitaker, T.J.

    1979-07-01

    Software was developed for a PDP11V/03-based data acquisition system to support the Light-Ion Irradiation Creep Experiment installed at the University of Washington Tandem Van de Graaff Accelerator. The software consists of a real-time data acquisition and storage program, DAC04, written in assembly language. This program provides for the acquisition of up to 30 chennels at 100 Hz, data averaging before storage on disk, alarming, data table display, and automatic disk switching. All analog data are acquired via an analog-to-digital converter subsystem having a resolution of 14 bits, a maximum throughput of 20 kHz, and an overall system accuracy of +-0.01%. These specifications are considered essential for the long-term measurement of irradiation creep strains and temperatures during the light-ion bombardment of irradiation creep specimens. The software package developed also contains a collection of FORTRAN programs designed to monitor a test while in progress. These programs use the foreground/background feature of the RT-11 operating system. The background programs provide a variety of services. The program, GRAFTR, allows transient data (i.e., prior to averaging) to be graphed at the graphics terminal. The program, GRAFAV, allows averaged data to be read from disk and displayed graphically at the terminal. The program, TYPAV, reads averaged data from disk and displays it at the terminal in tabular form. Other programs allow text messages to be written to disk, read from disk, and allow access to DAC04 initialization data. 5 figures, 18 tables

  18. Simulation of alpha decay of actinides in iron phosphate glasses by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dube, Charu L., E-mail: dubecharu@gmail.com; Stennett, Martin C.; Gandy, Amy S.; Hyatt, Neil C.

    2016-03-15

    Highlights: • Alpha decay of actinides in iron phosphate glasses is simulated by employing ion irradiation technique. • FTIR and Raman spectroscopic measurements confirm modification of glass network. • The depolymerisation of glass network after irradiation is attributed to synergetic effect of nuclear and electronic losses. - Abstract: A surrogate approach of ion beam irradiation is employed to simulate alpha decay of actinides in iron phosphate nuclear waste glasses. Bismuth and helium ions of different energies have been selected for simulating glass matrix modification owing to radiolysis and ballistic damage due to recoil atoms. Structural modification and change in coordination number of network former were probed by employing Reflectance Fourier-Transform Infrared (FT-IR), and Raman spectroscopies as a consequence of ion irradiation. Depolymerisation is observed in glass sample irradiated at intermediate energy of 2 MeV. Helium blisters of micron size are seen in glass sample irradiated at low helium ion energy of 30 keV.

  19. Irradiation effect of different heavy ions and track section on the silkworm Bombyx mori

    International Nuclear Information System (INIS)

    Tu Zhenli; Kobayashi, Yasuhiko; Kiguchi, Kenji; Watanabe, Hiroshi

    2003-01-01

    In order to compare the irradiation effects of different ions, wandering larvae were whole-body exposed or locally irradiated with 50-MeV 4 He 2+ , 220-MeV 12 C 5+ , and 350-MeV 20 Ne 8+ ions, respectively. For the whole-body-exposed individuals, the survival rates at the cocooning, pupation, and emergence stages all decreased as dose increased, and a range-dependent difference was clearly observed. For local irradiation of ovaries, irradiation effects depend very strongly on the projectile range. In the case of local irradiation of dermal cells by different track sections of heavy ions, the closer the target was to the high-LET section of the track, the more pronounced were the radiation effects. These results indicated that by selectively using ion species and adjusting the irradiation depth to the target, heavy-ion radiosurgery on particular tissues or organs of small experimental animals can be performed more accurately

  20. Effect of phase instabilities on the correlation of nickel ion and neutron irradiation swelling in solution annealed 316 stainless steel

    International Nuclear Information System (INIS)

    Rowcliffe, A.F.; Lee, E.H.; Sklad, P.S.

    1979-01-01

    Annealed 316 stainless steel specimens were neutron irradiated to establish steady-state microstructures and then subjected to further high temperature irradiations with 4 MeV Ni ions. It is shown that void growth under neutron irradiation is simulated in ion irradiations carried out at approx. 180 0 C above reactor temperature. However, the precipitate microstructure developed during neutron irradiation is unstable during subsequent ion irradiation. As a result, the relative swelling rates at various reactor temperatures are not simulated correctly

  1. In-situ observation of damage evolution in TiC crystals during helium ion irradiation

    International Nuclear Information System (INIS)

    Hojou, K.; Otsu, H.; Furuno, S.; Izui, K.; Tsukamoto, T.

    1994-01-01

    In-situ observations were performed on bubble formation and growth in TiC during 20 keV helium ion irradiation over the wide range of irradiation temperatures from 12 to 1523 K. No amorphization occurred over this temperature range. The bubble densities and sizes were almost independent of irradiation temperatures from 12 to 1273 K. Remarkable growth and coalescence occurred during irradiation at high temperature above 1423 K and during annealing above 1373 K after irradiation. ((orig.))

  2. Surface ripple evolution by argon ion irradiation in polymers

    International Nuclear Information System (INIS)

    Goyal, Meetika; Aggarwal, Sanjeev; Sharma, Annu

    2016-01-01

    In this report, an attempt has been made to investigate the morphological evolution of nanoscale surface ripples on aliphatic (polypropylene, PP) and aromatic (polyethylene terephthalate, PET) polymeric substrates irradiated with 50 keV Ar"+ ions. The specimens were sputtered at off normal incidence of 30° with 5 × 10"1"6 Ar"+ cm"−"2. The topographical features and structural behavior of the specimens were studied using Atomic Force Microscopy (AFM) and UV-Visible spectroscopy techniques, respectively. The Stopping and Range of Ions in Matter simulations were performed to calculate sputtering yield of irradiated PP and PET polymers. Sputtering yield of carbon atoms has been found to be smaller for PP (0.40) as compared to PET (0.73), which is attributed to the different structures of two polymers. AFM analysis demonstrates the evolution of ripple like features with amplitude (2.50 nm) and wavelength (690 nm) on PET while that of lower amplitude (1.50 nm) and higher wavelength (980 nm) on PP specimen. The disorder parameter (Urbach energy) has been found to increase significantly from 0.30 eV to 1.67 eV in case of PP as compared to a lesser increase from 0.35 eV to 0.72 eV in case of PET as revealed by UV-Visible characterization. A mutual correlation between ion beam sputtering induced topographical variations with that of enhancement in the disorder parameter of the specimens has been discussed.

  3. Helium retention in krypton ion pre-irradiated nanochannel W film

    Science.gov (United States)

    Qin, Wenjing; Ren, Feng; Zhang, Jian; Dong, Xiaonan; Feng, Yongjin; Wang, Hui; Tang, Jun; Cai, Guangxu; Wang, Yongqiang; Jiang, Changzhong

    2018-02-01

    Nanochannel tungsten (W) film is a promising candidate as an alternative to bulk W for use in fusion applications. In previous work it has been shown to have good radiation resistance under helium (He) irradiation. To further understand the influence of the irradiation-induced displacement cascade damage on helium retention behaviour in a fusion environment, in this work, nanochannel W film and bulk W were pre-irradiated by 800 keV Kr2+ ions to the fluence of 2.6  ×  1015 ions cm-2 and subsequently irradiated by 40 keV He+ ions to the fluence of 5  ×  1017 ions cm-2. The Kr2+ ion pre-irradiation greatly increases helium retention in the form of small clusters and retards the formation of large clusters. It can effectively inhibit surface helium blistering under high temperature annealing. Compared with bulk W, no cracks were found in the nanochannel W film post-irradiated by He+ ions at high fluence. The release of helium from the nanochannel W film is more than one order of magnitude higher than that of bulk W whether they are irradiated by single He+ ions or sequentially irradiated by Kr2+ and He+ ions. Moreover, swelling of the bulk W is more serious than that of the nanochannel film. Therefore, nanochannel W film has a higher radiation tolerance performance in the synergistic irradiation.

  4. Application of heavy-ion microbeam system at Kyoto University: Energy response for imaging plate by single ion irradiation

    International Nuclear Information System (INIS)

    Tosaki, M.; Nakamura, M.; Hirose, M.; Matsumoto, H.

    2011-01-01

    A heavy-ion microbeam system for cell irradiation has been developed using an accelerator at Kyoto University. We have successfully developed proton-, carbon-, fluorine- and silicon-beams in order to irradiate a micro-meter sized area with ion counting, especially single ion irradiation. In the heavy-ion microbeam system, an imaging plate (IP) was utilized for beam diagnostics on the irradiation. The IP is widely used for radiography studies in biology. However, there are a few studies on the low linear energy transfer (LET) by single ions, i.e., low-intensity exposure. Thus we have investigated the energy response for the IP, which can be utilized for microbeam diagnostics.

  5. Development of porous structures in GaSb by ion irradiation

    International Nuclear Information System (INIS)

    Jacobi, C.C.; Steinbach, T.; Wesch, W.

    2012-01-01

    Ion irradiation of GaSb causes not only defect formation but also leads to the formation of a porous structure. To study the behaviour of this structural modification, GaSb was irradiated with 6 MeV Iodine ions and ion fluences from 5 × 10 12 to 6 × 10 15 ions/cm 2 . The samples were investigated by step height measurements and scanning electron microscopy (SEM). Experiments were performed with two different procedures: (CI) Continuous Irradiation of samples followed by measurements of the step height in air and (SI) Stepwise Irradiation of samples with measurements of the step height in air between subsequent irradiations. Samples irradiated continuously, show a linear increase of the step height with increasing ion fluence up to 1.5 × 10 14 ions/cm 2 followed by a steeper, linear increase for higher ion fluences up to a step height of 32 μm. This swelling is induced by a formation of voids, and the two different slopes can be explained by a transformation from isolated voids to a rod like structure. For samples irradiated accordingly to procedure (SI), the step height shows the same behaviour up to an ion fluence of 1.5 × 10 14 ions/cm 2 resulting in a step height of ≈3 μm but then decreases with further irradiation. The latter effect is caused by a compaction of the porous structure.

  6. Evolution of structural and magnetic properties of Co-doped TiO2 thin films irradiated with 100 MeV Ag7+ ions

    International Nuclear Information System (INIS)

    Mohanty, P; Singh, V P; Rath, Chandana; Mishra, N C; Ojha, S; Kanjilal, D

    2014-01-01

    In continuation to our earlier studies where we have shown room temperature ferromagnetism observed in TiO 2 and Co-doped TiO 2 (CTO) thin films independent of their phase (Mohanty et al 2012 J. Phys. D: Appl. Phys. 45 325301), here the modifications in structure and magnetic properties in CTO thin films using 100 MeV Ag 7+ ion irradiation are reported. Owing to the important role of defects in tailoring the magnetic properties of the material, we vary the ion fluence from 5 × 10 11 to 1 × 10 12  ions cm −2 to create post-deposition defects. While the film deposited under 0.1 mTorr oxygen partial pressure retains its crystallinity showing radiation-resistant behaviour even at a fluence of 1 × 10 12  ions cm −2 , films deposited under 1 to 300 mTorr oxygen partial pressure becomes almost amorphous at the same fluence. Using Poisson's law, the diameter of the amorphized region surrounding the ion path is calculated to be ∼4.2 nm from the x-ray diffraction peak intensity ((1 1 0) for rutile phase) as a function of ion fluence. The saturation magnetization (M s ) decreases exponentially similar to the decrease in x-ray peak intensity with fluence, indicating magnetic disordered region surrounding the ion path. The diameter of the magnetic disordered region is found to be ∼6.6 nm which is larger than the diameter of the amorphized latent track. Therefore, it is confirmed that swift heavy ion irradiation induces a more significant magnetic disorder than the structural disorder. (paper)

  7. Ion-recombination correction factor κsat for spherical ion chambers irradiated by continuous photom beams

    International Nuclear Information System (INIS)

    Piermattei, A.; Azario, L.; Arcovito, G.

    1996-01-01

    The large range of reference air kerma rates of brachytherapy sources involves the use of large-volume ionization chambers. When such ionization chambers are used the ion-recombination correction factor k sat has to be determined. In this paper three spherical ion chambers with volume ranging from 30 to 10 4 cm 3 have been irradiated by photons of a 192 Ir source to determine the k sat factors. The ionization currents of the