WorldWideScience

Sample records for kev ion irradiation

  1. Irradiation effects on secondary structure of protein induced by keV ions

    International Nuclear Information System (INIS)

    Cui, F.Z.; Lin, Y.B.; Zhang, D.M.; Tian, M.B.

    2001-01-01

    Protein secondary structure changes by low-energy ion irradiation are reported for the first time. The selected system is 30 keV N + irradiation on bovine serum albumin (BSA). After irradiation at increasing fluences from 1.0x10 15 to 2.5x10 16 ion/cm 2 , Fourier transform infrared spectra analysis was conducted. It was found that the secondary structures of BSA molecules were very sensitive to ion irradiation. Secondary conformations showed different trends of change during irradiation. With the increase of ion fluence from 0 to 2.5x10 16 ion/cm 2 , the fraction of α-helix and β-turns decreased from 17 to 12%, and from 40 to 31%, respectively, while that of random coil and β-sheet structure increased from 18 to 27%, and from 25 to 30%, respectively. Possible explanations for the secondary conformational changes of protein are proposed. (author)

  2. Irradiation damage in aluminium single crystals produced by 50-keV aluminium and copper ions

    DEFF Research Database (Denmark)

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

    1968-01-01

    Aluminium single crystals, thin enough to be examined by electron microscopy, have been irradiated with 50-keV aluminium and copper ions. The irradiation fluxes were in the range 1011–1014 cm−2 s−1 and the doses were from 6 × 1012 to 6 × 1014 cm−2. Irradiation along either a or a direction produces...... rows of dislocation loops all lying parallel to one particular direction. If the aluminium target is quenched from 600 °C and annealed at room temperature prior to irradiation with aluminium ions, the rows of loops are suppressed. The amount of damage observed is considerably less than would...

  3. Radiation blistering in Inconel-625 due to 100 KeV helium ion irradiation

    International Nuclear Information System (INIS)

    Whitton, J.L.; Rao, A.S.; Kaminsky, M.

    1988-01-01

    The objective of this study was to determine whether the change of angle of incidence of an ion beam impinging on surface blisters during their growth phase (before exfoliation) could influence the blister skin thickness and the blister crater depth. Polished, polycrystalline Inconel-625 samples were irradiated at room temperature and at normal incidence to the major sample surface with 100 keV helium ions to a total dose of 6.24x10 18 ions/cm 2 . The results revealed that many exfoliated blisters leave craters which have two or three concentric pits. The blister skin thickness near the center of the blister was found to agree well with the calculated projected range of 100 keV He ions in nickel. However, the blister skin thickness of some exfoliated blisters along the edge of the fracture surface showed different thicknesses. A model is proposed to explain the observed blister crater/blister fracture features in terms of a change of angle of incidence of the incident ions to the surface during the growth phase of surface blisters. (orig.)

  4. Depth distribution of 2-keV helium-ion irradiation-induced cavities in nickel

    International Nuclear Information System (INIS)

    Fenske, G.; Das, S.K.; Kaminsky, M.

    1981-01-01

    Transmission electron microscopy has been used to study the effect of total dose on the depth distribution of cavities (voids or bubbles) in nickel irradiated at 500 0 C with 20-keV 4 He + ions. A transverse sectioning technique allowed us to obtain the entire depth distribution of cavities from a single specimen. The diameter, number density and volume fraction of cavities were measured as a function of depth from micrographs taken from samples sectioned parallel to the direction of the incident beam. Results for the doses at 2.9 x 10 15 and 2.9 x 10 16 ions/cm 2 show an increase in the average cavity diameter, number density and volume fraction with increasing dose. A further increase in dose from 2.9 x 10 16 to 2.9 x 10 17 ions/cm 2 also shows an increase in the average cavity diameter but a decrease in the number density. This observation is interpreted as evidence for the coalescence of cavities. 3 figures, 1 table

  5. Structural and optical modification in 4H-SiC following 30 keV silver ion irradiation

    Science.gov (United States)

    Kaushik, Priya Darshni; Aziz, Anver; Siddiqui, Azher M.; Lakshmi, G. B. V. S.; Syväjärvi, Mikael; Yakimova, Rositsa; Yazdi, G. Reza

    2018-05-01

    The market of high power, high frequency and high temperature based electronic devices is captured by SiC due to its superior properties like high thermal conductivity and high sublimation temperature and also due to the limitation of silicon based electronics in this area. There is a need to investigate effect of ion irradiation on SiC due to its application in outer space as outer space is surrounded both by low and high energy ion irradiations. In this work, effect of low energy ion irradiation on structural and optical property of 4H-SiC is investigated. ATR-FTIR is used to study structural modification and UV-Visible spectroscopy is used to study optical modifications in 4H-SiC following 30 keV Ag ion irradiation. FTIR showed decrease in bond density of SiC along the ion path (track) due to the creation of point defects. UV-Visible absorption spectra showed decrease in optical band gap from 3.26 eV to 2.9 eV. The study showed degradation of SiC crystallity and change in optical band gap following low energy ion irradiation and should be addressed while fabricationg devices based on SiC for outer space application. Additionally, this study provides a platform for introducing structural and optical modification in 4H-SiC using ion beam technology in a controlled manner.

  6. The study of the ion beam induced swelling in crystalline germanium irradiated by a 30 keV Ga+ focused ion beam

    International Nuclear Information System (INIS)

    Rubanov, S.; Munroe, P.R.; Stevens-Kalceff, M.

    2005-01-01

    The effect of swelling of crystalline Ge irradiated at room temperature with 30 keV Ga + focused ion beam (FIB) was studied by means of in situ FIB imaging, atomic force microscopy (AFM) and transmission electron microscopy (TEM). The swelling occurred in the surface region of amorphous damage layer which was formed during ion irradiation. The degree of swelling reaches values up to 10 times for an implantation dose of ∼10 17 ions/cm 2 . Cross-secitonal TEM examination showed that the swelling is due to formation of a porous layer with a honeycomb structure. (author). 8 refs., 4 figs

  7. Effects of electronic excitation in 150 keV Ni ion irradiation of metallic systems

    Science.gov (United States)

    Zarkadoula, Eva; Samolyuk, German; Weber, William J.

    2018-01-01

    We use the two-temperature model in molecular dynamic simulations of 150 keV Ni ion cascades in nickel and nickel-based alloys to investigate the effect of the energy exchange between the atomic and the electronic systems during the primary stages of radiation damage. We find that the electron-phonon interactions result in a smaller amount of defects and affect the cluster formation, resulting in smaller clusters. These results indicate that ignoring the local heating due to the electrons results in the overestimation of the amount of damage and the size of the defect clusters. A comparison of the average defect production to the Norgett-Robinson-Torrens (NRT) prediction over a range of energies is provided.

  8. In situ MeV ion beam analysis of ceramic surfaces modified by 100-400 keV ion irradiation

    International Nuclear Information System (INIS)

    Weber, W.J.; Yu, N.; Sickafus, K.E.

    1995-05-01

    This paper describes use of the in situ ion beam analysis facility developed at Los Alamos National Laboratory for the study of irradiation effects in ceramic materials. In this facility, an analytical beamline of 3 MV tandem accelerator and an irradiation bean-dine of 200 kV ion implanter are connected at 60 degrees to a common target chamber. This facility provides a fast, efficient, and quantitative measurement tool to monitor changes of composition and crystallinity of materials irradiated by 100-400 keV ions, through sequential measurement of backscattering events of MeV ions combined with ion channeling techniques. We will describe the details of the in situ ion beam analysis and ion irradiation and discuss some of the important issues and their solutions associated with the in situ experiment. These issues include (1) the selection of axial ion channeling direction for the measurement of radiation damage; (2) surface charging and charge collection for data acquisition; (3) surface sputtering during ion irradiation; (4) the effects of MeV analytical beam on the materials; and (5) the sample heating effect on ion beam analysis

  9. Effect of dose on the evolution of cavities in 500-KeV 4He+-ion irradiated nickel

    International Nuclear Information System (INIS)

    Fenske, G.; Das, S.K.; Kaminsky, M.; Miley, G.H.

    1979-01-01

    Transmission electron microscopy has been used to investigate the effect of total dose on the depth distribution of cavities (voids or bubbles) in nickel irradiated at 500 0 C with 500-keV 4 He + ions. A transverse sectioning technique, which allows one to obtain the entire depth distribution of cavities and of damage from a single specimen, was utilized. The size, number density and volume fraction of bubbles or voids were measured from the micrographs taken from samples sectioned parallel to the direction of the incident beam. The results for the dose range studied (2 x 10 19 to 1 x 10 21 ions/m 2 ) show that the average cavity diameter, number density, and the volume fraction (i.e., swelling) increases with increasing dose. The peak in the swelling distribution occurs at depths 8 to 15% deeper than the peak in the calculated projected range profile

  10. Synthesis of Au nanoparticles at the surface and embedded in carbonaceous matrix by 150 keV Ar ion irradiation

    International Nuclear Information System (INIS)

    Prakash, Jai; Tripathi, Jalaj; Tripathi, A; Kumar, P; Asokan, K; Avasthi, D K; Rigato, V; Pivin, J C; Chae, Keun Hwa; Gautam, Sanjeev

    2011-01-01

    We report on synthesis of spherical Au nanoparticles at the surface and embedded in carbonaceous matrix by 150 keV Ar ion irradiation of thin Au film on polyethyleneterepthlate (PET). The pristine and irradiated samples are characterized by Rutherford backscattering spectrometry (RBS), atomic force microscopy, scanning electron microscopy and transmission electron microscopy (TEM) techniques. RBS spectra reveal the sputtering of Au film and interface mixing, increasing with increasing fluence. Surface morphology shows that at the fluence of 5 x 10 15 ions cm -2 , dewetting of thin Au film begins and partially connected nanostructures are formed whereas, at the higher fluence of 5 x 10 16 ions cm -2 , isolated spherical Au nanoparticles (45 ± 20 nm) are formed at the surface. Cross-sectional TEM observations also evidence the Au nanoparticles at the surface and mixed metal-polymer region indicating the formation of nanocomposites with small Au nanoparticles. The results are explained by the crater formation, sputtering followed by dewetting of the thin Au film and interdiffusion at the interface, through molten zones due to thermal spike induced by Ar ions.

  11. Evolution of porous network in GaSb under normally incident 60 keV Ar{sup +}-ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Datta, D.P. [SUNAG Laboratory, Institute of Physics, Bhubaneswar 751 005, Odisha (India); Kanjilal, A. [Department of Physics, Shiv Nadar University, Gautam Budh Nagar 203 207, Uttar Pradesh (India); Garg, S.K. [SUNAG Laboratory, Institute of Physics, Bhubaneswar 751 005, Odisha (India); Sahoo, P.K. [School of Physical Sciences, National Institute of Science Education and Research, Bhubaneswar 751 005, Odisha (India); Satpati, B. [Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Kanjilal, D. [Inter-University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Som, T., E-mail: tsom@iopb.res.in [SUNAG Laboratory, Institute of Physics, Bhubaneswar 751 005, Odisha (India)

    2014-08-15

    Highlights: • We show the evolution of a nanoporous layer in GaSb under Ar{sup +}-ion bombardment at normal incidence in the hitherto unexplored high fluence regime, namely 7 × 10{sup 16}–3 × 10{sup 18} ions cm{sup −2}. • Fluence dependent formation and growth of patches on top of the nanoporous layer is demonstrated by scanning electron microscopy. • We also show high amount of oxidation of such ion-beam-generated nanoporous structures, with formation of Ga{sub 2}O{sub 3} and Sb{sub 2}O{sub 3}. • Our study reveals the presence of nanocrystallites within the porous layer even at the highest fluence used in the experiment. • We interpret the experimental observations through a qualitative model where we take into account the effect of re-deposition of atoms sputtered from the nanoporous layer during Ar{sup +}-ion irradiation of GaSb. - Abstract: GaSb(1 0 0) samples were irradiated with 60 keV Ar{sup +}-ions at normal incidence for fluences in the range of 7 × 10{sup 16} to 3 × 10{sup 18} ions cm{sup −2} at room temperature, showing gradual evolution of a porous surface layer containing interconnected nanofibers. In particular, fluence dependent formation of patches on the nanoporous layer is observed by scanning electron microscopy. Combined results of grazing incidence x-ray diffraction and transmission electron microscopy reveal the presence of nanocrystallites in the porous structures. Compositional analysis by x-ray photoelectron spectroscopy indicates the development of oxide phases, mainly Ga{sub 2}O{sub 3} and Sb{sub 2}O{sub 3} where the former increases with fluence. We have proposed a model addressing a competition between ion-induced-defect driven growth of the nanoporous layer and redeposition of sputtered target atoms on the growing layer.

  12. In-situ XMCD evaluation of ferromagnetic state at FeRh thin film surface induced by 1 keV Ar ion beam irradiation and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, T. [Research Organization for the 21st Century, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Aikoh, K. [Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Sakamaki, M.; Amemiya, K. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Iwase, A. [Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan)

    2015-12-15

    Surface ferromagnetic state of FeRh thin films irradiated with 1 keV Ar ion-beam has been investigated by using soft X-ray Magnetic Circular Dichroism (XMCD). It was revealed that the Fe atoms of the samples were strongly spin-polarized after Ar ion-beam irradiation. Due to its small penetration depth, 1 keV Ar ion-beam irradiation can modify the magnetic state at subsurface of the samples. In accordance with the XMCD sum rule analysis, the main component of the irradiation induced ferromagnetism at the FeRh film surface was to be effective spin magnetic moment, and not to be orbital moment. We also confirmed that the surface ferromagnetic state could be produced by thermal annealing of the excessively ion irradiated paramagnetic subsurface of the FeRh thin films. This novel magnetic modification technique by using ion irradiation and subsequent annealing can be a potential tool to control the surface magnetic state of FeRh thin films.

  13. Optical transmittance investigation of 1-keV ion-irradiated sapphire crystals as potential VUV to NIR window materials of fusion reactors

    Directory of Open Access Journals (Sweden)

    Keisuke Iwano

    2016-10-01

    Full Text Available We investigate the optical transmittances of ion-irradiated sapphire crystals as potential vacuum ultraviolet (VUV to near-infrared (NIR window materials of fusion reactors. Under potential conditions in fusion reactors, sapphire crystals are irradiated with hydrogen (H, deuterium (D, and helium (He ions with 1-keV energy and ∼ 1020-m-2 s-1 flux. Ion irradiation decreases the transmittances from 140 to 260 nm but hardly affects the transmittances from 300 to 1500 nm. H-ion and D-ion irradiation causes optical absorptions near 210 and 260 nm associated with an F-center and an F+-center, respectively. These F-type centers are classified as Schottky defects that can be removed through annealing above 1000 K. In contrast, He-ion irradiation does not cause optical absorptions above 200 nm because He-ions cannot be incorporated in the crystal lattice due to the large ionic radius of He-ions. Moreover, the significant decrease in transmittance of the ion-irradiated sapphire crystals from 140 to 180 nm is related to the light scattering on the crystal surface. Similar to diamond polishing, ion irradiation modifies the crystal surface thereby affecting the optical properties especially at shorter wavelengths. Although the transmittances in the VUV wavelengths decrease after ion irradiation, the transmittances can be improved through annealing above 1000 K. With an optical transmittance in the VUV region that can recover through simple annealing and with a high transparency from the ultraviolet (UV to the NIR region, sapphire crystals can therefore be used as good optical windows inside modern fusion power reactors in terms of light particle loadings of hydrogen isotopes and helium.

  14. Change of Cr atoms distribution in Fe85Cr15 alloy caused by 250 keV He+ ion irradiation to different doses

    International Nuclear Information System (INIS)

    Dubiel, S.M.; Żukrowski, J.

    2015-01-01

    Highlights: • Effect of He-ion irradiation dose on Fe 85 Cr 15 alloy. • Irradiation-induced clustering of Cr atoms. • Irradiation-caused reorientation of the surface magnetization vector. • Irradiation-caused increase of Fe-site spin-density. - Abstract: Redistribution of Cr atoms in a Fe 85 Cr 15 alloy caused by its irradiation with 250 keV He + ions to different doses, D = 8 ⋅ 10 16 , 16 ⋅ 10 16 and 48 ⋅ 10 16 ions/cm 2 was investigated by means of conversion electrons Mössbauer spectroscopy. The redistribution was expressed in terms of the Warren–Cowley short-range order parameters α 1 , α 2 and α 12 pertaining to the first (1NN), second (2NN) and both i.e. 1NN + 2NN shells, respectively. Clear evidence was found, both for non-irradiated and irradiated samples that the actual distribution of Cr atoms is characteristic of the shell, and for a given shell it depends on the irradiation dose. In particular, α 1 is positive, hence indicates an under population of Cr atoms in 1NN with respect to the random case, α 2 is negative, giving evidence thereby that 2NN is overpopulated by Cr atoms, and α 12 is weakly positive. Under the applied irradiation the number of Cr atoms in both neighbor shells decreased signifying thereby a clustering of Cr atoms. The underlying decrease of Cr concentration within the 1NN–2NN volume around the probe Fe atoms was estimated at 1.5 at.% ranging between 2.1 for the lowest and 0.8 at.% for the highest dose

  15. 500 keV Ar2+ ion irradiation induced anatase to brookite phase transformation and ferromagnetism at room temperature in TiO2 thin films

    Science.gov (United States)

    Bharati, B.; Mishra, N. C.; Kanjilal, D.; Rath, Chandana

    2018-01-01

    In our earlier report, where we have demonstrated ferromagnetic behavior at room temperature (RT) in TiO2 thin films deposited through electron beam evaporation technique followed by annealing either in Ar or O2 atmosphere [Mohanty et al., Journal of Magnetism and Magnetic Materials 355 (2014) 240-245], here we have studied the evolution of structure and magnetic properties after irradiating the TiO2 thin films with 500 keV Ar2+ ions. The pristine film while exhibits anatase phase, the films become amorphous after irradiating at fluence in the range 1 × 1014 to 1 × 1016 ions/cm2. Increasing the fluence up to 5 × 1016 ions/cm2, amorphous to crystalline phase transformation occurs and the structure becomes brookite. Although anatase to rutile phase transformation is usually reported in literatures, anatase to brookite phase transformation is an unusual feature which we have reported here for the first time. Such anatase to brookite phase transformation is accompanied with grain growth without showing any change in film thickness evidenced from Rutherford's Back Scattering (RBS) measurement. From scanning probe micrographs (SPM), roughness is found to be more in amorphous films than in the crystalline ones. Anatase to brookite phase transformation could be realized by considering the importance of intermediate amorphous phase. Because due to amorphous phase, heat deposited by energetic ions are localized as dissipation of heat is less and as a result, the localized region crystallizes in brookite phase followed by grain growth as observed in highest fluence. Further, we have demonstrated ferromagnetic behavior at RT in irradiated films similar to pristine one, irrespective of their phase and crystallinity. Origin for room temperature ferromagnetism (RTFM) is attributed to the presence of oxygen vacancies which is confirmed by carrying out XPS measurement.

  16. Sputtering characteristics of B4C-overlaid graphite for keV energy deuterium ion irradiation

    International Nuclear Information System (INIS)

    Gotoh, Y.; Yamaki, T.; Ando, T.; Jimbou, R.; Ogiwara, N.; Saidoh, M.; Teruyama, K.

    1992-01-01

    Two types of B 4 C-overlaid graphite (CFC), conversion and CVD B 4 C, together with bare CFC (PCC-2S) and/or HP B 4 C, were investigated with respect to erosion yields for 1 keV D + , D 2 /CD 4 TDS after 1 keV D + implantation, and thermal diffusivity/conductivity, in a temperature range from 300 to 1400 K. The erosion yields of both conversion and CVD B 4 C were found to be much lower than that of the bare CFC (PCC-2S), in both chemical sputtering (600-1100 K) and RES (1200-1400 K) temperature regions. The D 2 TDS peak of the conversion B 4 C was found to be located at nearly 200 K lower temperature than that of the bare CFC (PCC-2S), indicating much lower activation energy for detrapping/recombination of trapped D in the conversion B 4 C and in the CFC. The CD 4 TDS peak of the conversion B 4 C was found to be much weaker in intensity than that of the bare CFC (PCC-2S), in agreement with the present erosion yield results. Thermal diffusivities and conductivities of both the conversion B 4 C/PCC-2S and the CVD B 4 C, were measured to be nearly 1/10 of that of the bare CFC (PCC-2S), and to decrease with increasing temperatures. (orig.)

  17. 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 ...

  18. Radiation blistering of Nb implanted sequentially with helium ions of different energies (3-500 keV)

    International Nuclear Information System (INIS)

    Guseva, M.I.; Gusev, V.; Krasulin, U.L.; Martinenko, U.V.; Das, S.K.; Kaminsky, M.S.

    1976-01-01

    Cold rolled, polycrystalline niobium samples were irradiated at room temperature with 4 He + ions sequentially at 14 different energies over an energy range from 3 keV--500 keV in steps of 50 keV. The dose for each energy was chosen to give an approximately uniform concentration of helium between the implant depths corresponding to 3 keV and 500 keV. In one set of experiments the irradiations were started at the Kurchatov Institute with 3 keV 4 He + ions and extended up to 80 keV in several steps. Subsequently, the same target area was irradiated with 4 He + ions at Argonne National Laboratory (ANL) starting at 100 keV and increased to 500 keV in steps of 50 keV. Another set of irradiations were started at ANL with 500 keV 4 He + ions and continued with decreasing ion energies to 100 keV. Subsequently, the same area was irradiated at the Kurchatov Institute starting at 80 keV and continued with decreasing ion energies to 3 keV. Both sets of irradiations were completed for two different total doses, 0.5 C cm -2 and 1.0 C cm -2

  19. Degradation of PET, PEEK and PI induced by irradiation with 150 keV Ar+ and 1.76 MeV He+ ions

    Czech Academy of Sciences Publication Activity Database

    Macková, Anna; Havránek, Vladimír; Švorčík, V.; Suzuki, T.; Djourelov, N.

    2005-01-01

    Roč. 240, 1/2 (2005), s. 245-249 ISSN 0168-583X R&D Projects: GA MŠk(CZ) OC 527.100 Institutional research plan: CEZ:AV0Z10480505 Keywords : irradiated polymers * ion beam modification * ERDA Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.181, year: 2005

  20. Topography evolution of 500 keV Ar(4+) ion beam irradiated InP(100) surfaces - formation of self-organized In-rich nano-dots and scaling laws.

    Science.gov (United States)

    Sulania, Indra; Agarwal, Dinesh C; Kumar, Manish; Kumar, Sunil; Kumar, Pravin

    2016-07-27

    We report the formation of self-organized nano-dots on the surface of InP(100) upon irradiating it with a 500 keV Ar(4+) ion beam. The irradiation was carried out at an angle of 25° with respect to the normal at the surface with 5 different fluences ranging from 1.0 × 10(15) to 1.0 × 10(17) ions per cm(2). The morphology of the ion-irradiated surfaces was examined by atomic force microscopy (AFM) and the formation of the nano-dots on the irradiated surfaces was confirmed. The average size of the nano-dots varied from 44 ± 14 nm to 94 ± 26 nm with increasing ion fluence. As a function of the ion fluence, the variation in the average size of the nano-dots has a great correlation with the surface roughness, which changes drastically up to the ion fluence of 1.0 × 10(16) ions per cm(2) and attains almost a saturation level for further irradiation. The roughness and the growth exponent values deduced from the scaling laws suggest that the kinetic sputtering and the large surface diffusion steps of the atoms are the primary reasons for the formation of the self-organized nanodots on the surface. X-ray photo-electron spectroscopy (XPS) studies show that the surface stoichiometry changes with the ion fluence. With irradiation, the surface becomes more indium (In)-rich owing to the preferential sputtering of the phosphorus atoms (P) and the pure metallic In nano-dots evolve at the highest ion fluence. The cross-sectional scanning electron microscopy (SEM) analysis of the sample irradiated with the highest fluence showed the absence of the nanostructuring beneath the surface. The surface morphological changes at this medium energy ion irradiation are discussed in correlation with the low and high energy experiments to shed more light on the mechanism of the well separated nano-dot formation.

  1. 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...

  2. Tuning of wettability of PANI-GNP composites using keV energy ions

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmi, G.B.V.S., E-mail: lakshmigbvs@gmail.com [Inter University Accelerator Centre, New Delhi 67 (India); Avasthi, D.K. [Amity University, Noida 201313, Uttar Pradesh (India)

    2016-07-15

    Polyaniline nanofiber composites with various nanomaterials have several applications in electrochemical biosensors. The surface properties of these composites coated electrodes play crucial role in enzyme absorption and analyte detection process. In the present study, Polyaniline-Graphene nanopowder (PANI-GNP) composites were prepared by rapid-mixing polymerization method. The films were prepared on ITO coated glass substrates and irradiated with 42 keV He{sup +} ions produced by indigenously fabricated accelerator at IUAC, New Delhi. The films were characterized before and after irradiation by SEM, Raman spectroscopy and contact angle measurements. The as-prepared films show superhydrophilic nature and after irradiation the films show highly hydrophobic nature with water contact angle (135°). The surface morphology was studied by SEM and structural changes were studied by Raman spectra. The surface morphological modifications induced by keV energy ions helps in tuning the wettability at different ion fluences.

  3. Characteristics of > 290 keV magnetosheath ions

    Directory of Open Access Journals (Sweden)

    A. Rigas

    Full Text Available We performed a statistical analysis of 290-500 keV ion data obtained by IMP-8 during the years 1982-1988 within the earth's magnetosheath and analysed in detail some time periods withdistinct ion bursts. These studies reveal the following characteristics for magnetosheath 290-500 keV energetic ions: (a the occurrence frequency and the flux of ions increase with increasing geomagnetic activity as indicated by the Kp index; the occurrence frequency was found to be as high as P > 42% for Kp > 2, (b the occurrence frequency in the dusk magnetosheath was found to be slightly dependent on the local time and ranged between ~30% and ~46% for all Kp values; the highest occurrence frequency was detected near the dusk magnetopause (21 LT, (c the high energy ion bursts display a dawn-dusk asymmetry in their maximum fluxes, with higher fluxes appearing in the dusk magnetosheath, and (d the observations in the dusk magnetosheath suggest that there exist intensity gradients of energetic ions from the bow shock toward the magnetopause. The statistical results are consistent with the concept that leakage of magnetospheric ions from the dusk magnetopause is a semi-permanent physical process often providing the magnetosheath with high energy (290-500 keV ions.Key words. Magnetospheric physics (magnetosheath; planetary magnetospheres. Space plasma physics (shock waves.

  4. Sputtering of solid nitrogen by keV helium ions

    DEFF Research Database (Denmark)

    Ellegaard, O.; Schou, Jørgen; Sørensen, H.

    1993-01-01

    Solid nitrogen has become a standard material among the frozen molecular gases for electronic sputtering. We have combined measurements of sputtering yields and energy spectra from nitrogen bombarded by 4-10 keV helium ions. The data show that the erosion is electronic rather than knockon...

  5. Energy reflection coefficient for H+ ions at energies between 10 and 80 keV

    International Nuclear Information System (INIS)

    Chen, C.K.; Bohdansky, J.; Eckstein, W.; Robinson, M.T.

    1984-04-01

    The energy reflection coefficient for H + ions at energies between 10 keV and 80 keV was determined by experiments and by computer calculations. Measurements were made with graphite, Al, Cu, Mo and W. targets. The angle of ion incidence was restricted to 85 0 , 78 0 and 70 0 measured from the surface normal. Calculated data were obtained by two different Monte Carlo computer programs (MARLOWE, TRIM). It was found that both the calculated and the measured data scale with the parameter epsilon cos 2 α, where epsilon is Lindhard's reduced energy and α the angle of incidence for the ions. The measured values are smaller than those calculated. This can be explained by surface roughness which developed during the ion irradiation

  6. Experiments on secondary ion emission with multicharged keV ion bombardement

    International Nuclear Information System (INIS)

    Della Negra, S.; Depauw, J.; Joret, H.; Le Beyec, Y.; Schweikert, E.A.

    1987-01-01

    An electron cyclotron resonance ion source was used to study the influence of the incident charge state of keV ions on secondary ion emission. The experiments were run with 18 keV Arn+ (1 < n < 11) beams produced by a minimafios source. Various types of targets were bombarded by the ion beam and the sputtered ionized species were identified by time of flight mass spectrometry. The experimental arrangement is detailed and preliminary results are indicated

  7. Depth control of a silicon structure fabricated by 100q keV Ar ion beam lithography

    Energy Technology Data Exchange (ETDEWEB)

    Kawasegi, Noritaka [Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)]. E-mail: kawasegi@eng.u-toyama.ac.jp; Morita, Noboru [Department of Mechanical and Intellectual Systems Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)]. E-mail: nmorita@eng.u-toyama.ac.jp; Yamada, Shigeru [Department of Mechanical and Intellectual Systems Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)]. E-mail: syamada@eng.u-toyama.ac.jp; Takano, Noboru [Department of Mechanical and Intellectual Systems Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)]. E-mail: takano@eng.u-toyama.ac.jp; Oyama, Tatsuo [Department of Mechanical and Intellectual Systems Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)]. E-mail: ohyama@eng.u-toyama.ac.jp; Momota, Sadao [Department of Intelligent Mechanical Systems Engineering, Kochi University of Technology, 185 Tosayamada, Kami, Kochi 782-8502 (Japan)]. E-mail: momota.sadao@kochi-tech.ac.jp; Taniguchi, Jun [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)]. E-mail: junt@te.noda.tus.ac.jp; Miyamoto, Iwao [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)]. E-mail: iwao@te.noda.tus.ac.jp

    2007-01-15

    Ion beam lithography of a silicon surface using an Ar ion beam with an ion energy in the order of hundreds of keV is demonstrated in this study. A specially designed ion irradiation facility was employed that enabled generation and irradiation with a highly accelerated and highly charged Ar ion beam. An ion-beam-induced amorphous layer on a silicon substrate can be selectively etched in hydrofluoric acid, whereas, a non-irradiated area is scarcely etched and, consequently, a concave structure can be fabricated on the irradiated area. To control the depth of the structure, parameters for dependence of the depth on ion irradiation were investigated. As a result, the depth of irradiated area can be controlled by the ion energy that is adjusted by the acceleration voltage and the ion charge. In addition, the etch resistance of the irradiated area increases with an increase in ion energy due to the crystalline layer formed on the surface. Simulation results reveal that the depth is strongly related to the defect distribution induced by ion irradiation. These results indicate the potential use of this method for novel three-dimensional lithography.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. Deactivation of group III acceptors in silicon during keV electron irradiation

    International Nuclear Information System (INIS)

    Sah, C.; Sun, J.Y.; Tzou, J.J.; Pan, S.C.

    1983-01-01

    Experimental results on p-Si metal-oxide-semiconductor capacitors (MOSC's) are presented which demonstrate the electrical deactivation of the acceptor dopant impurity during 8-keV electron irradiation not only in boron but also aluminum and indium-doped silicon. The deactivation rates of the acceptors during the 8-keV electron irradiation are nearly independent of the acceptor impurity type. The final density of the remaining active acceptor approaches nonzero values N/sub infinity/, with N/sub infinity/(B) Al--H>In-H. These deactivation results are consistent with our hydrogen bond model. The thermal annealing or regeneration rate of the deactivated acceptors in the MOSC's irradiated by 8-keV electron is much smaller than that in the MOSC's that have undergone avalanche electron injection, indicating that the keV electron irradiation gives rise to stronger hydrogen-acceptor bond

  14. Surface damage in cystine, an amino acid dimer, induced by keV ions.

    Science.gov (United States)

    Salles, R C M; Coutinho, L H; da Veiga, A G; Sant'Anna, M M; de Souza, G G B

    2018-01-28

    We have studied the interaction of an ion beam (17.6 keV F - ) with cystine, a dimer formed by the binding of two cysteine residues. Cystine can be considered as an ideal prototype for the study of the relevance of the disulfide (-S-S-) chemical bond in biomolecules. For the sake of comparison, the amino acid cysteine has also been subjected to the same experimental conditions. Characterization of the samples by XPS and NEXAFS shows that both pristine cystine and pristine cysteine are found as a dipolar ion (zwitterion). Following irradiation, the dimer and the amino acid show a tendency to change from the dipole ion form to the normal uncharged form. The largest spectral modification was observed in the high resolution XPS spectra obtained at around the N 1s core level for the two biomolecules. The 2p sulfur edge spectra of cysteine and cystine were much less sensitive to radiation effects. We suggest that the disulfide bond (-S-S-) remains stable before and after irradiation, contributing to the larger radiation stability of cystine as compared to the amino acid cysteine.

  15. Design and fabrication of a Transverse Field Focussing (TFF) 180 keV negative ion accelerator

    International Nuclear Information System (INIS)

    Matuk, C.A.; Anderson, O.A.; Owren, H.M.; Paterson, J.A.; Purgalis, P.

    1985-11-01

    The 180 keV Transverse Field Focussing (TFF) negative ion accelerator described is the final component of a negative ion based neutral beam acceleration system which is being developed as proof-of-principle demonstration of a radiation hardened neutral beamline. The 180 keV beamline consists of: a surface conversion negative ion source, a 80 keV pre-accelerator, a TFF pumping, matching, and transport section, and the 180 keV TFF accelerator presented. This beamline is expected to provide 1 A of H - at 180 keV. In the design of the accelerator, particular importance was given to the rigidity of the accelerator electrode mounting structures and to the electrical isolation of the electrodes along with their related cooling lines. An optical alignment scheme was developed to assemble and to insure precision alignment of the electrodes

  16. 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

  17. Effect of solute atoms on collision cascades in copper and molybdenum irradiated with self-ions

    International Nuclear Information System (INIS)

    English, C.A.; Eyre, B.L.; Wadley, H.; Stathopoulos, A.Y.

    1975-01-01

    An examination of the effect material purity has on the numbers and sizes of the vacancy loops formed in collision cascades produced by self-ion irradiation of copper and molybdenum is reported. It is shown that substitutional and interstitial impurities both markedly reduce the damage generated in molybdenum by 60 keV Mo + ions but little effect is seen in copper irradiated by 30 keV Cu + ions. These results are compared with recent observations of vacancy defects in type 316 stainless steel following irradiation with 40-200 keV Cr + . The comparison highlights the much lower vacancy concentration retained in visible clusters in the complex alloy

  18. 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.

  19. Depth distribution of bubbles in He-ion irradiated nickel and the mechanism of blister formation

    International Nuclear Information System (INIS)

    Fenske, G.; Das, S.K.; Kaminsky, M.; Miley, G.H.

    1978-01-01

    Studies carried out to understand the experimental observation that the blister skin thickness for many metals irradiated with He + ions of energies lower than 20 keV is a factor of two or more larger than the calculated projected range are reported. Nickel foils were used with 20 and 500 keV helium ions

  20. 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.

  1. 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.)

  2. 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)

  3. Spatial distribution of upstream magnetospheric ≥50 keV ions

    Directory of Open Access Journals (Sweden)

    G. C. Anagnostopoulos

    2000-01-01

    Full Text Available We present for the first time a statistical study of \\geq50 keV ion events of a magnetospheric origin upstream from Earth's bow shock. The statistical analysis of the 50-220 keV ion events observed by the IMP-8 spacecraft shows: (1 a dawn-dusk asymmetry in ion distributions, with most events and lower intensities upstream from the quasi-parallel pre-dawn side (4 LT-6 LT of the bow shock, (2 highest ion fluxes upstream from the nose/dusk side of the bow shock under an almost radial interplanetary magnetic field (IMF configuration, and (3 a positive correlation of the ion intensities with the solar wind speed and the index of geomagnetic index Kp, with an average solar wind speed as high as 620 km s-1 and values of the index Kp > 2. The statistical results are consistent with (1 preferential leakage of ~50 keV magnetospheric ions from the dusk magnetopause, (2 nearly scatter free motion of ~50 keV ions within the magnetosheath, and (3 final escape of magnetospheric ions from the quasi-parallel dawn side of the bow shock. An additional statistical analysis of higher energy (290-500 keV upstream ion events also shows a dawn-dusk asymmetry in the occurrence frequency of these events, with the occurrence frequency ranging between ~16%-~34% in the upstream region.Key words. Interplanetary physics (energetic particles; planetary bow shocks

  4. Spatial distribution of upstream magnetospheric ≥50 keV ions

    Directory of Open Access Journals (Sweden)

    G. Kaliabetsos

    Full Text Available We present for the first time a statistical study of geq50 keV ion events of a magnetospheric origin upstream from Earth's bow shock. The statistical analysis of the 50-220 keV ion events observed by the IMP-8 spacecraft shows: (1 a dawn-dusk asymmetry in ion distributions, with most events and lower intensities upstream from the quasi-parallel pre-dawn side (4 LT-6 LT of the bow shock, (2 highest ion fluxes upstream from the nose/dusk side of the bow shock under an almost radial interplanetary magnetic field (IMF configuration, and (3 a positive correlation of the ion intensities with the solar wind speed and the index of geomagnetic index Kp, with an average solar wind speed as high as 620 km s-1 and values of the index Kp > 2. The statistical results are consistent with (1 preferential leakage of ~50 keV magnetospheric ions from the dusk magnetopause, (2 nearly scatter free motion of ~50 keV ions within the magnetosheath, and (3 final escape of magnetospheric ions from the quasi-parallel dawn side of the bow shock. An additional statistical analysis of higher energy (290-500 keV upstream ion events also shows a dawn-dusk asymmetry in the occurrence frequency of these events, with the occurrence frequency ranging between ~16%-~34% in the upstream region.Key words. Interplanetary physics (energetic particles; planetary bow shocks

  5. Calibration of dosimeters at 80-120 keV electron irradiation

    DEFF Research Database (Denmark)

    Miller, A.; Helt-Hansen, J.

    to calibrate thin-film dosimeters (Risø B3 and alanine films) by irradiation at the 80–120 keV electron accelerators. This calibration was compared to a 10MeV calibration, and we show that the radiation response of the dosimeter materials (the radiation chemical yield) is constant at these irradiation energies....... However, dose gradients within the dosimeters, when it is irradiated at low electron energies,mean that calibration function here will depend on both irradiation energy and the required effective point of measurement of the dosimeter. These are general effects that apply to any dosimeter that has a non...

  6. Surface damage in TEM thick α-Fe samples by implantation with 150 keV Fe ions

    International Nuclear Information System (INIS)

    Aliaga, M.J.; Caturla, M.J.; Schäublin, R.

    2015-01-01

    We have performed molecular dynamics simulations of implantation of 150 keV Fe ions in pure bcc Fe. The thickness of the simulation box is of the same order of those used in in situ TEM analysis of irradiated materials. We assess the effect of the implantation angle and the presence of front and back surfaces. The number and type of defects, ion range, cluster distribution and primary damage morphology are studied. Results indicate that, for the very thin samples used in in situ TEM irradiation experiments the presence of surfaces affect dramatically the damage produced. At this particular energy, the ion has sufficient energy to damage both the top and the back surfaces and still leave the sample through the bottom. This provides new insights on the study of radiation damage using TEM in situ

  7. Ionoluminescence properties of polystyrene-hosted fluorophore films induced by helium ions of energy 50-350 keV

    Science.gov (United States)

    Chakraborty, Subha; Huang, Mengbing

    2017-10-01

    We report on measurements and analysis of ionoluminescence properties of pure polystyrene films and polystyrene films doped with four types of fluorophores in low kinetic energies (50-350 keV) of ion irradiation. We have developed a theoretical model to understand the experimentally observed ionoluminescence behaviors in terms of scintillation yield from individual ion tracks, photophysical energy transfer mechanisms, and irradiation-induced defects. A comparison of the model and experimental results suggests that singlet up-conversion resulting from triplet-triplet annihilation processes may be responsible for enhanced singlet emission of the fluorophores at high ion beam flux densities. Energy transfer from the polystyrene matrix to the fluorophore molecules has been identified as an effective pathway to increasing the fluorescence efficiency in the doped scintillator films.

  8. Calibration of thin-film dosimeters irradiated with 80-120 kev electrons

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.; McEwen, M.

    2004-01-01

    A method for calibration of thin-film dosimeters irradiated with 80-120keV electrons has been developed. The method is based on measurement of dose with a totally absorbing graphite calorimeter, and conversion of dose in the graphite calorimeter to dose in the film dosimeter by Monte Carlo calcul......V electron irradiation. The two calibrations were found to be equal within the estimated uncertainties of +/-10% at 1 s.d. (C) 2004 Elsevier Ltd. All rights reserved....

  9. Dose response of thin-film dosimeters irradiated with 80-120 keV electrons

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.; Sharpe, P.

    2005-01-01

    Thin-film dosimeters (Riso B3 and alanine films) were irradiated at 10 MeV and 80-120 keV electron accelerators, and it has been shown that the radiation response of the dosimeter materials (the radiation chemical yields) are constant at these irradiation energies. However, dose gradients within ...... are present within the dosimeter. (C) 2005 Elsevier Ltd. All rights reserved....

  10. A study on the microstructural parameters of 550 keV electron irradiated Lexan polymer films

    International Nuclear Information System (INIS)

    Hareesh, K.; Pramod, R.; Petwal, V. C.; Dwivedi, Jishnu; Sangappa; Sanjeev, Ganesh

    2012-01-01

    Lexan polymer films irradiated with 550 keV Electron Beam (EB) were characterized using Wide Angle Xray Scattering (WAXS) data to study the microstructural parameters. The crystal imperfection parameters like crystal size , lattice strain (g in %) and enthalpy (α) have been determined by Line Profile Analysis (LPA) using Fourier method of Warren.

  11. Dislocation loops in spinel crystals irradiated successively with deep and shallow ion implants

    International Nuclear Information System (INIS)

    Ai, R.X.; Cooper, E.A.; Sickafus, K.E.; Nastasi, M.; Bordes, N.; Ewing, R.C.

    1993-01-01

    This study examines the influence of microstructural defects on irradiation damage accumulation in the oxide spinel. Single crystals of the compound MgAl 2 O 4 with surface normal [111] were irradiated under cryogenic temperature (100K) either with 50 keV Ne ions (fluence 5.0 x 10 12 /cm 2 ), 400 keV Ne ions (fluence 6.7 x 10 13 /cm 2 ) or successively with 400 keV Ne ions followed by 50 keV Ne ions. The projected range of 50 keV Ne ions in spinel is ∼50 mn (''shallow'') while the projected range of 400 keV Ne ions is ∼500 mn (''deep''). Transmission electron microscopy (TEM) was used to examine dislocation loops/defect clusters formed by the implantation process. Measurements of the dislocation loop size were made using weak-beam imaging technique on cross-sectional TEM ion-implanted specimens. Defect clusters were observed in both deep and shallow implanted specimens, while dislocation loops were observed in the shallow implanted sample that was previously irradiated by 400 keV Ne ions. Cluster size was seen to increase for shallow implants in crystals irradiated with a deep implant (size ∼8.5 nm) as compared to crystals treated only to a shallow implant (size ∼3.1 nm)

  12. Effect of 200 keV proton irradiation on the properties of methyl silicone rubber

    International Nuclear Information System (INIS)

    Zhang Lixin; Xu Zhou; Wei Qiang; He Shiyu

    2006-01-01

    The effects of 200 keV proton irradiation on methyl silicone rubber were studied. The changes in surface morphology, mechanical properties, cross-linking density, glass transition temperature, infrared attenuated total reflection spectrum and mass spectrum indicated that, at lower fluence, the proton irradiation induced cross-linking, resulting in an increase in tensile strength and hardness of the methyl silicone rubber. However, at higher proton fluence, radiation-induced degradation, which decreased the tensile strength and hardness, became dominant. A macromolecular-network destruction model for silicone rubber irradiated with protons was proposed

  13. 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.

  14. 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)

  15. 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

  16. A 20 keV electron gun system for the electron irradiation experiments

    International Nuclear Information System (INIS)

    Mahapatra, S.K.; Dhole, S.D.; Bhoraskar, V.N.

    2005-01-01

    An electron gun consisting of cathode, focusing electrode, control electrode and anode has been designed and fabricated for the electron irradiation experiments. This electron gun can provide electrons of any energy over the range 1-20 keV, with current upto 50 μA. This electron gun and a Faraday cup are mounted in the cylindrical chamber. The samples are fixed on the Faraday cup and irradiated with electrons at a pressure ∼10 -7 mbar. The special features of this electron gun system are that, at any electron energy above 1 keV, the electron beam diameter can be varied from 5 to 120 mm on the Faraday cup mounted at a distance of 200 mm from the anode in the chamber. The variation in the electron current over the beam spot of 120 mm diameter is less than 15% and the beam current stability is better than 5%. This system is being used for studying the irradiation effects of 1-20 keV energy electrons on the space quality materials in which the irradiation time may vary from a few tens of seconds to hours

  17. A 20 keV electron gun system for the electron irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, S.K. [Department of Physics, University of Pune, Pune 411007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411007 (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411007 (India)]. E-mail: vnb@physics.unipune.ernet.in

    2005-01-01

    An electron gun consisting of cathode, focusing electrode, control electrode and anode has been designed and fabricated for the electron irradiation experiments. This electron gun can provide electrons of any energy over the range 1-20 keV, with current upto 50 {mu}A. This electron gun and a Faraday cup are mounted in the cylindrical chamber. The samples are fixed on the Faraday cup and irradiated with electrons at a pressure {approx}10{sup -7} mbar. The special features of this electron gun system are that, at any electron energy above 1 keV, the electron beam diameter can be varied from 5 to 120 mm on the Faraday cup mounted at a distance of 200 mm from the anode in the chamber. The variation in the electron current over the beam spot of 120 mm diameter is less than 15% and the beam current stability is better than 5%. This system is being used for studying the irradiation effects of 1-20 keV energy electrons on the space quality materials in which the irradiation time may vary from a few tens of seconds to hours.

  18. 380 keV proton irradiation effects on photoluminescence of Eu-doped GaN

    International Nuclear Information System (INIS)

    Okada, Hiroshi; Nakanishi, Yasuo; Wakahara, Akihiro; Yoshida, Akira; Ohshima, Takeshi

    2008-01-01

    The effect of 380 keV proton irradiation on the photoluminescence (PL) properties has been investigated for undoped and Eu-doped GaN. As the proton irradiation exceeds 1x10 13 cm -2 , a drastic decrease of PL intensity of the near band-edge emission of undoped GaN was observed. On the other hand, for Eu-doped GaN, the PL emission corresponding to the 5 D 0 → 7 F 2 transition in Eu 3+ kept the initial PL intensity after the proton irradiation up to 1x10 14 cm -2 . Present results, together with our previous report on electron irradiation results, suggest that Eu-doped GaN is a strong candidate for light emitting devices in high irradiation environment

  19. Study of SiO2 surface sputtering by a 250-550 keV He+ ion beam during high-resolution Rutherford backscattering measurements

    International Nuclear Information System (INIS)

    Kusanagi, Susumu; Kobayashi, Hajime

    2006-01-01

    Decreases in oxygen signal intensities in spectra of high-resolution Rutherford backscattering spectrometry (HRBS) were observed during measurements on a 5-nm thick SiO 2 layer on a Si substrate when irradiated by 250-550 keV He + ions. Shifts in an implanted arsenic profile in a 5-nm thick SiO 2 /Si substrate were also observed as a result of He + ion irradiation. These results lead to the conclusion that the SiO 2 surface was sputtered by He + ions in this energy range

  20. Electron beam dosimetry for a thin-layer absorber irradiated by 300-keV electrons

    International Nuclear Information System (INIS)

    Kijima, Toshiyuki; Nakase, Yoshiaki

    1993-01-01

    Depth-dose distributions in thin-layer absorbers were measured for 300-keV electrons from a scanning-type irradiation system, the electrons having penetrated through a Ti-window and an air gap. Irradiations of stacks of cellulose triacetate(CTA) film were carried out using either a conveyor (i.e. dynamic irradiation) or fixed (i.e. static) irradiation. The sample was irradiated using various angles of incidence of electrons, in order to examine the effect of obliqueness of electron incidence at low-energy representative of routine radiation curing of thin polymeric or resin layers. Dynamic irradiation gives broader and shallower depth-dose distributions than static irradiation. Greater obliqueness of incident electrons gives results that can be explained in terms of broader and shallower depth-dose distributions. The back-scattering of incident electrons by a metal(Sn) backing material enhances the absorbed dose in a polymeric layer and changes the overall distribution. It is suggested that any theoretical estimations of the absorbed dose in thin layers irradiated in electron beam curing must be accomplished and supported by experimental data such as that provided by this investigation. (Author)

  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. Erosion of volatile elemental condensed gases by keV electron and light-ion bombardment

    International Nuclear Information System (INIS)

    Schou, J.

    1991-11-01

    Erosion of the most volatile elemental gases by keV electron and light-ion bombardment has been studied at the experimental setup at Risoe. The present work includes frozen neon, argon, krypton, nitrogen, oxygen and three hydrogen isotopes, deuterium, hydrogen deuteride and hydrogen. The yield of these condensed gases has been measured as a function of film thickness and primary energy for almost all combinations of primary particles (1-3 keV electrons, 5-10 keV hydrogen- and helium ions) and ices. These and other existing results show that there are substantial common features for the sputtering of frozen elemental gases. Within the two groups, the solid rare gases and the solid molecular gases, the similarity is striking. The hydrogenic solids deviate in some respects from the other elements. The processes that liberate kinetic energy for the particle ejection in sputtering are characteristic of the specific gas. (au) 3 tabs., 12 ills., 159 refs

  3. Sputtering of solid nitrogen and oxygen by keV hydrogen ions

    DEFF Research Database (Denmark)

    Ellegaard, O.; Schou, Jørgen; Stenum, B.

    1994-01-01

    Electronic sputtering of solid nitrogen and oxygen by keV hydrogen ions has been studied at two low-temperature setups. The yield of the sputtered particles has been determined in the energy regime 4-10 keV for H+, H-2+ and H-3+ ions. The yield for oxygen is more than a factor of two larger than...... that for nitrogen. The energy distributions of the sputtered N2 and O2 molecules were measured for hydrogen ions in this energy regime as well. The yields from both solids turn out to depend on the sum of the stopping power of all atoms in the ion. The yield increases as a quadratic function of the stopping power...

  4. Design of a continuously operated 1-keV deuterium-ion extractor

    International Nuclear Information System (INIS)

    Fink, J.H.

    1978-01-01

    A novel grid structure that is cooled only by radiation and conduction is shown to be capable of continuously extracting 2.5 kA.m -2 of 1-keV positive deuterium ions while dissipating a power loading of 0.4 MW.m -2

  5. Effects of uranium bombardment by 20-40 KeV argon ions, Annex 2

    International Nuclear Information System (INIS)

    Nenadovic, T.; Jurela, Z.

    1966-01-01

    This paper shows the results of argon ions interaction with the polycrystal natural uranium. Thin foil of uranium about 200 μ was bombarded by 20-40 KeV argon ions. Coefficients of cathode scattering δ and secondary electrons emission γ were measured, during the process A + →U. The foil was then studied by transmission method and method of single step replica using an electron microscope [sr

  6. Influence of 400 keV carbon ion implantation on structural, optical and electrical properties of PMMA

    Energy Technology Data Exchange (ETDEWEB)

    Arif, Shafaq, E-mail: sarif2005@gmail.com [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Rafique, M. Shahid [Department of Physics, University of Engineering & Technology, Lahore 54000 (Pakistan); Saleemi, Farhat; Sagheer, Riffat [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Naab, Fabian; Toader, Ovidiu [Department of Nuclear Engineering and Radiological Sciences, Michigan Ion Beam Laboratory, University of Michigan, MI 48109-2104 (United States); Mahmood, Arshad; Rashid, Rashad [National Institute of Lasers and Optronics (NILOP), P.O. Nilore, Islamabad (Pakistan); Mahmood, Mazhar [Department of Metallurgy & Materials Engineering, Pakistan Institute of Engineering & Applied Sciences (PIEAS), Islamabad (Pakistan)

    2015-09-01

    Ion implantation is a useful technique to modify surface properties of polymers without altering their bulk properties. The objective of this work is to explore the 400 keV C{sup +} ion implantation effects on PMMA at different fluences ranging from 5 × 10{sup 13} to 5 × 10{sup 15} ions/cm{sup 2}. The surface topographical examination of irradiated samples has been performed using Atomic Force Microscope (AFM). The structural and chemical modifications in implanted PMMA are examined by Raman and Fourier Infrared Spectroscopy (FTIR) respectively. The effects of carbon ion implantation on optical properties of PMMA are investigated by UV–Visible spectroscopy. The modifications in electrical conductivity have been measured using a four point probe technique. AFM images reveal a decrease in surface roughness of PMMA with an increase in ion fluence from 5 × 10{sup 14} to 5 × 10{sup 15} ions/cm{sup 2}. The existence of amorphization and sp{sup 2}-carbon clusterization has been confirmed by Raman and FTIR spectroscopic analysis. The UV–Visible data shows a prominent red shift in absorption edge as a function of ion fluence. This shift displays a continuous reduction in optical band gap (from 3.13 to 0.66 eV) due to formation of carbon clusters. Moreover, size of carbon clusters and photoconductivity are found to increase with increasing ion fluence. The ion-induced carbonaceous clusters are believed to be responsible for an increase in electrical conductivity of PMMA from (2.14 ± 0.06) × 10{sup −10} (Ω-cm){sup −1} (pristine) to (0.32 ± 0.01) × 10{sup −5} (Ω-cm){sup −1} (irradiated sample)

  7. Magnetic field design for a Penning ion source for a 200 keV electrostatic accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Fathi, A., E-mail: Atefeh.Fathi115@gmail.com [Radiation Applications Department, Shahid Beheshti University, G. C., Tehran (Iran, Islamic Republic of); Feghhi, S.A.H.; Sadati, S.M. [Radiation Applications Department, Shahid Beheshti University, G. C., Tehran (Iran, Islamic Republic of); Ebrahimibasabi, E. [Department of Physics, Shahrood University of Technology, 3619995161, Shahrood (Iran, Islamic Republic of)

    2017-04-01

    In this study, the structure of magnetic field for a Penning ion source has been designed and constructed with the use of permanent magnets. The ion source has been designed and constructed for a 200 keV electrostatic accelerator. With using CST Studio Suite, the magnetic field profile inside the ion source was simulated and an appropriate magnetic system was designed to improve particle confinement. Designed system consists of two ring magnets with 9 mm distance from each other around the anode. The ion source was constructed and the cylindrical magnet and designed magnetic system were tested on the ion source. The results showed that the ignition voltage for ion source with the designed magnetic system is almost 300 V lower than the ion source with the cylindrical magnet. Better particle confinement causes lower voltage discharge to occur.

  8. Fragmentation of anthracene induced by collisions with 40 keV Ar8+ ions

    International Nuclear Information System (INIS)

    Brédy, R; Ortéga, C; Ji, M; Bernard, J; Chen, L; Montagne, G; Martin, S

    2013-01-01

    We report on the fragmentation of anthracene molecular ions C 14 H 10 r+ as a function of the parent ion initial charge r (= 1–4). Neutral anthracene molecules in the gas phase were ionized and excited in collisions with Ar 8+ ions at 40 keV and the mass-to-charge spectra of the parent ions C 14 H 10 r+ (1 ⩽ r ⩽ 4) were obtained. Stable molecular ions C 14 H 10 r+ (1 ⩽ r ⩽ 3) are observed. Branching ratios for the competitive evaporation (loss of neutral fragments) and fragmentation (charge separation) processes were measured for C 14 H 10 2+ parent ions. For C 14 H 10 3+ parent ions, the results indicate that fragmentation is the only dominant process and quasi-symmetric fission is observed. (paper)

  9. First experiments with the 200 keV electron beam ion trap at LLNL

    International Nuclear Information System (INIS)

    Marrs, R.E.; Knapp, D.A.; Elliott, S.

    1993-01-01

    A high-energy electron beam ion trap (Super EBIT) is operating at electron energies up to 200 keV and currents up to 200 mA. Highly charged ions up to Li-like U 89+ and H-like Pb 81+ have been produced and studied. Ionization cross sections for H-like Dy 66+ at E e = 170 keV have been measured with respect to radiative recombination from the observed Dy 66+ /Dy 67+ equilibrium ionization balance. A Bragg crystal spectrometer has been used to measure 2s 1/2 -2p 3/2 transition energies in Li-like U 82+ with respect to the Lymann-series transitions in lower-Z hydrogenic ions

  10. Steady State Sputtering Yields and Surface Compositions of Depleted Uranium and Uranium Carbide bombarded by 30 keV Gallium or 16 keV Cesium Ions.

    Energy Technology Data Exchange (ETDEWEB)

    Siekhaus, W. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Teslich, N. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Weber, P. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-10-23

    Depleted uranium that included carbide inclusions was sputtered with 30-keV gallium ions or 16-kev cesium ions to depths much greater than the ions’ range, i.e. using steady-state sputtering. The recession of both the uranium’s and uranium carbide’s surfaces and the ion corresponding fluences were used to determine the steady-state target sputtering yields of both uranium and uranium carbide, i.e. 6.3 atoms of uranium and 2.4 units of uranium carbide eroded per gallium ion, and 9.9 uranium atoms and 3.65 units of uranium carbide eroded by cesium ions. The steady state surface composition resulting from the simultaneous gallium or cesium implantation and sputter-erosion of uranium and uranium carbide were calculated to be U₈₆Ga₁₄, (UC)₇₀Ga₃₀ and U₈₁Cs₉, (UC)₇₉Cs₂₁, respectively.

  11. Effect of irradiation with <200 keV electrons on AG-80 resin

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yu [School of Materials Science and Engineering, Harbin Institute of Technology, 432 Heilongjiang province, Harbin 150001 (China)]. E-mail: czq04@yahoo.com.cn; Jiang Shengling [College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Sun Mingren [School of Materials Science and Engineering, Harbin Institute of Technology, 432 Heilongjiang province, Harbin 150001 (China); Yang Dezhuang [School of Materials Science and Engineering, Harbin Institute of Technology, 432 Heilongjiang province, Harbin 150001 (China); He Shiyu[School of Materials Science and Engineering, Harbin Institute of Technology, 432 Heilongjiang province, Harbin 150001 (China); Li Zhijun [39th Institute, China Electronic Science and Technology Groups Inc., Xi-an 710065 (China)

    2005-08-01

    AG-80 resin, namely tetraglycidyl diaminodiphenyl methane (TGDDM), is a new type of thermosetting matrix for advanced carbon/epoxy composites, which was irradiated with electrons of 160 keV. The results show that by increasing the fluence to 6.3x10{sup 15} cm{sup -2}, the mass loss ratio ascends dramatically and then tends to level off. The mass loss behavior can be attributed to the combined effects of the formation of gaseous radiolytic products and a degraded layer, the surface ablation due to discharging and the skin carbon enrichment.

  12. 60 keV Ar⁺-ion induced modification of microstructural, compositional, and vibrational properties of InSb

    Energy Technology Data Exchange (ETDEWEB)

    Datta, D. P.; Garg, S. K.; Som, T., E-mail: tsom@iopb.res.in [SUNAG Laboratory, Institute of Physics, Bhubaneswar, Odisha 751005 (India); Satpati, B. [Surface Physics and Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Sahoo, P. K. [School of Physical Sciences, National Institute of Science Education and Research, Bhubaneswar 751005, Odisha (India); Kanjilal, A. [Department of Physics, Shiv Nadar University, Uttar Pradesh 203207 (India); Dhara, S. [Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2014-10-14

    Room temperature irradiation of InSb(111) by 60 keV Ar⁺-ions at normal (0°) and oblique (60°) angles of incidence led to the formation of nanoporous structure in the high fluence regime of 1×10¹⁷ to 3×10¹⁸ ions cm⁻². While a porous layer comprising of a network of interconnected nanofibers was generated by normal ion incidence, evolution of plate-like structures was observed for obliquely incident ions. Systematic studies of composition and structure using energy dispersive x-ray spectroscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, Raman mapping, grazing incidence x-ray diffraction, and cross-sectional transmission electron microscopy revealed a high degree of oxidation of the ion-induced microstructures with the presence of In₂O₃ and Sb₂O₃ phases and presence of nanocrystallites within the nanoporous structures. The observed structural evolution was understood in terms of processes driven by ion-induced defect accumulation within InSb.

  13. Development of a keV single-ion-implanter for nanofabrication

    International Nuclear Information System (INIS)

    Yang, C.; Jamieson, D.N.; Hopf, T.; Tamanyan, G.; Spizziri, P.; Pakes, C.; Andresen, S.E.; Hudson, F.; Gauja, E.; Dzurak, A.; Clark, R.G.

    2005-01-01

    Traditional methods of doping semiconductors have a difficulty meeting the demand for high precision doping due to large statistical fluctuations in the numbers of dopant atoms introduced in the ever shrinking volume in micro- and nano-electronics devices, especially when the fabrication process approaches the nanometre scale. The statistical fluctuations in doping semiconductors for the fabrication of devices with a very small feature size may lead to inconsistent and unreliable performance. This paper describes the adaptation of a commercial ion implanter into a single-ion-implantation system for the accurate delivery of dopants into a nanometre or micrometre area in a silicon substrate. All the implanted ions can be accurately counted with near 100% certainty through online detection using the silicon substrate itself as an ion detector. A variety of ion species including B + , N + , P + at the energy range of 10-15 keV can be delivered in the single ion implantation system. (author). 6 refs., 6 figs

  14. Ion trajectories of the MFTF unshielded 80-keV neutral-beam sources

    International Nuclear Information System (INIS)

    Ling, R.C.; Bulmer, R.H.; Cutler, T.A.; Foote, J.H.; Horvath, J.A.

    1978-01-01

    The trajectories of ions from the Magnetic Fusion Test Facility (MFTF) 80-keV neutral-beam sources are calculated to obtain a preliminary understanding of the ion-beam paths and the magnitude of the power densities. This information will be needed for locating and designing thermal (kinetic-energy) absorbers for the ions. The calculations are made by employing a number of previously written computer codes. The TIBRO code is used to calculate the trajectories of the ions in the fringe magnetic field of the MFTF machine, which can operate with a center-field intensity of up to 2 T. The SAMPP code gives three-dimensional views of the ion beams for better visualization of the ion-beam paths. Also used are the codes MIG, XPICK, and MERGE, which were all previously written for manipulating data

  15. 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.

  16. 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

  17. 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)

  18. Radiation effects in zinc oxide: zinc under bombardment with KeV ions

    International Nuclear Information System (INIS)

    Hastings, J.W.L.

    1967-01-01

    The energy loss, light output, depth of deterioration and the deterioration constant have been determined as a function of energy for various atomic projectiles impinging upon samples of a powdered Zn:Zn phosphor at energies below 105 KeV. The energy loss was observed as a reduction in the light output when projectiles traversed thin regions of previously damaged phosphor. The energy losses for heavier projectiles ( 14 N, 40 Ar, 84 Kr), relative to hydrogen, were found to be lower than those predicted for an amorphous stopping medium. The light output for a given projectile was found to be approximately proportional to the amount of energy lost in electronic collisions. When a phosphor is subjected to prolonged bombardment by heavy ions the deterioration depth is fairly well defined and its value was determined by a measurement of the energy loss of a hydrogen beam in traversing the damaged region. The depths are very large, are proportional to the projectile velocity and seem to be determined to a significant degree by electronic stopping. The deterioration constant, C, is a measure of the ability of a projectile to deteriorate a phosphor and its value is proportional to the number of defects introduced in unit distance along the trajectory of the projectile. The constant was determined from measurements of the efficiencies η, and η o , of partly damaged and undamaged phosphor, respectively, using the observed relationship, C (η/η o - 1) n -1 where n is the irradiation dose. The relative magnitudes of the C values for 14 N, 40 Ar were found to be in agreement with measured nuclear energy loss cross sections for these projectiles. (author)

  19. Cryogenic trapping of keV ion beams at the CSR prototype

    Energy Technology Data Exchange (ETDEWEB)

    Menk, Sebastian; Blaum, Klaus; Froese, Michael; Grieser, Manfred; Lange, Michael; Orlov, Dimitry; Sieber, Thomas; Hahn, Robert von; Varju, Jozef; Wolf, Andreas [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Heber, Oded; Rappaport, Michael; Zajfman, Daniel [Weizmann Institut of Science, Rehovot (Israel)

    2009-07-01

    A Cryogenic Trap for Fast ion beams (CTF) was built to explore cooling techniques and test thermal decoupling of ion optics for the development of the electrostatic Cryogenic Storage Ring (CSR). These challenging projects will lead to a new experimental field of atomic and molecular physics with keV ion beams. The cold conditions of 2-10 K minimize the blackbody radiation field and are expected to lead to extremely low restgas densities (equivalent pressure at room temperature {approx}10{sup -13} mbar) which result in long storage lifetimes and for molecular ions to radiative cooling to their ro-vibrational ground states. The CTF consists of two stacks of electrostatic mirror electrodes allowing the storage of up to 20 keV ion beams. Cryogenic ion beam storage has been realized with this device using a liquid helium refrigeration system to cool down the experimental trapping area to few-Kelvin cryogenic temperatures and experiments with cryogenically trapped molecular nitrogen ions have been performed to verify the low vacuum conditions by measuring their storage lifetimes.

  20. Interface-mediated amorphization of coesite by 200 keV electron irradiation

    International Nuclear Information System (INIS)

    Gong, W.L.; Wang, L.M.; Ewing, R.C.; Xie, H.S.

    1997-01-01

    Electron-induced amorphization of coesite was studied as a function of irradiation temperature by in situ transmission electron microscopy at an incident energy of 200 keV. Electron-induced amorphization of coesite is induced by an ionization mechanism and is mainly dominated by an interface-mediated, heterogeneous nucleation-and-growth controlled process. Amorphous domains nucleate at surfaces, crystalline-amorphous (c-a) interfaces, and grain boundaries. This is the same process as the interface-mediated vitrification of coesite by isothermal annealing above the thermodynamic melting temperature (875 K), but below the glass transition temperature (1480 K). The interface-mediated amorphization of coesite by electron irradiation is morphologically similar to interface-mediated thermodynamic melting. copyright 1997 American Institute of Physics

  1. Studies on the bombardment of condensed molecular gases at liquid-He temperatures by keV electrons and light ions

    International Nuclear Information System (INIS)

    Boergesen, P.

    1982-09-01

    Films of solid H 2 , D 2 and N 2 were irradiated with keV electrons and ions. Stopping cross sections and ranges of 0.3-10 keV/amu light ions in solid H 2 and D 2 are in good agreement with experimental and theoretical data on gaseous targets. In contrast, both stopping cross section and range measurements in solid N 2 suggest that the stopping here is only about half of that in N 2 -gas. This ''phase-effect'' is further supported by secondary emission measurements. Secondary electron emission coefficients for 2-10 keV H 1 + , H 2 + , H 3 + , D 3 + , D 2 H + , 4 He + , 14 N + and 20 Ne + incident on solids H 2 , D 2 and N 2 are in reasonable agreement with previous results for electron-incidence. The rather large erosion yields for 1-3 keV electrons incident on solid D 2 depend strongly on target thickness (for thin films), but weakly on energy. Bulk yields for 2 keV electrons were approximately 8 H 2 /electron, approximately 4 D 2 /electron and approximately 0.5 N 2 /electron. Secondary ion emission during ion bombardment seems to be predominantly reflected projectiles in the case of N 2 -targets, while it may be explained as sputtered particles from H 2 - and D 2 -targets. Preliminary results on the erosion of solid H 2 and D 2 by keV light ions indicate very large erosion yields (approx. 400 H 2 /atom for 2 keV protons) increasing strongly with energy. (Auth.)

  2. 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

  3. CSR: a new tool for storage and cooling of keV ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Froese, Michael; Blaum, Klaus; Crespo Lopez-Urrutia, Jose; Fellenberger, Florian; Grieser, Manfred; Kaiser, Dirk; Lange, Michael; Laux, Felix; Menk, Sebastian; Orlov, Dmitry A.; Repnow, Roland; Schroeter, Claus D.; Schwalm, Dirk; Sieber, Thomas; Ullrich, Joachim; Varju, Jozef; Hahn, Robert von; Wolf, Andreas [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Heber, Oded; Rappaport, Michael; Toker, Jonathan; Zajfman, Daniel [Weizman Institute of Science, Rehovot (Israel)

    2009-07-01

    An electrostatic Cryogenic Storage Ring (CSR) is currently being built in Heidelberg, Germany. The current status and final design of this ring, with a focus on the optimized 2 K chamber cooling, precision chamber suspension, and pumping down to extremely low pressures via cryogenic vacuum chambers will be presented. This ring will allow long storage times of highly charged ion and polyatomic molecular beams with energies in the range of keV per charge-state. Combining the long storage times with vacuum chamber temperatures approaching 2 K, infrared-active molecular ions will be radiatively cooled to their rotational ground states. Many aspects of this concept were experimentally tested with a cryogenic trap for fast ion beams (CTF), which has already demonstrated the storage of fast ion beams in a large cryogenic device. An upcoming test will investigate the effect of pre-baking the cryogenic vacuum chambers to 600 K on the cryogenic vacuum and the ion beam storage.

  4. TEM study of the ion beam induced damage during 14 kev P+ implantation in silicon

    International Nuclear Information System (INIS)

    Rubanov, S.; Tamanyan, G.; Hudson, F.; Jamieson, D.N.; McCallum, J.C.; Prawer, S.

    2005-01-01

    The proposed silicon-based quantum computer architecture comprises an array of phosphorus donor atoms (qubits) positioned with nanometre accuracy beneath the surface of a semiconductor host, using a single ion implantation technique. The average depth of the implanted ions (the projected range R p ), lateral range R p 1, and the distribution of ions about that depth can be approximated as two-dimensional Gaussian with standard deviation ΔR p and ΔR p 1 (lateral straggle). Using transmission electron microscopy (TEM) we studied ion beam induced damage after 14 keV P + implantation in Si. The TEM images allowed us to compare the depth of the amorphous cluster formation to R p , R p 1, ΔR p 1 calculated from SRIM and hence determine evidence for the limitation on the accuracy of the position of the implanted ions imposed by straggling. (author). 4 refs., 3 figs

  5. Experimental Set-up for Irradiation of Solid H2 and D2 with Charged Particles of keV Energies

    DEFF Research Database (Denmark)

    Sørensen, H.

    1976-01-01

    crystal film thickness monitor. The target plate, which can be heated so that films are removable by evaporation, may be used both as a calorimeter and as a beam current collector. Methods for measurement of secondary electron emission coefficients were developed, and preliminary measurements were made...... with electrons and hydrogen ions. For electron bombardment, the secondary electron emission coefficient of solid deuterium was much smaller than one. It was shown possible to use the set-up to study beam desorption of very thin films. Furthermore the set-up could be used for measuring the energy......An experimental facility was built where films of solid deuterium (and hydrogen) may be made with known thickness and irradiated with pulsed beams of electrons (up to 3 keV) and light ions (up to 10 keV). Films are made on a target plate held at 2.5–3 K. Film growth rate is calibrated with a quartz...

  6. Shape manipulation of ion irradiated Ag nanoparticles embedded in lithium niobate

    NARCIS (Netherlands)

    Wolf, S.; Rensberg, J.; Johannes, A.; Thomae, R.; Smit, F.; Neveling, R.; Moodley, M.; Bierschenk, T.; Rodriquez, M.; Afra, B.; Hasan, Shakeeb Bin; Rockstuhl, C.; Ridgway, M.; Bharuth-Ram, K.; Ronning, C.

    2016-01-01

    Spherical silver nanoparticles were prepared by means of ion beam synthesis in lithium niobate. The embedded nanoparticles were then irradiated with energetic 84Kr and 197Au ions, resulting in different electronic energy losses between 8.1 and 27.5 keV nm−1 in the top layer of the samples. Due to

  7. A cryogenic electrostatic trap for long-time storage of keV ion beams

    Science.gov (United States)

    Lange, M.; Froese, M.; Menk, S.; Varju, J.; Bastert, R.; Blaum, K.; López-Urrutia, J. R. Crespo; Fellenberger, F.; Grieser, M.; von Hahn, R.; Heber, O.; Kühnel, K.-U.; Laux, F.; Orlov, D. A.; Rappaport, M. L.; Repnow, R.; Schröter, C. D.; Schwalm, D.; Shornikov, A.; Sieber, T.; Toker, Y.; Ullrich, J.; Wolf, A.; Zajfman, D.

    2010-05-01

    We report on the realization and operation of a fast ion beam trap of the linear electrostatic type employing liquid helium cooling to reach extremely low blackbody radiation temperature and residual gas density and, hence, long storage times of more than 5 min which are unprecedented for keV ion beams. Inside a beam pipe that can be cooled to temperatures <15 K, with 1.8 K reached in some locations, an ion beam pulse can be stored at kinetic energies of 2-20 keV between two electrostatic mirrors. Along with an overview of the cryogenic trap design, we present a measurement of the residual gas density inside the trap resulting in only 2×103 cm-3, which for a room temperature environment corresponds to a pressure in the 10-14 mbar range. The device, called the cryogenic trap for fast ion beams, is now being used to investigate molecules and clusters at low temperatures, but has also served as a design prototype for the cryogenic heavy-ion storage ring currently under construction at the Max-Planck Institute for Nuclear Physics.

  8. A cryogenic electrostatic trap for long-time storage of keV ion beams.

    Science.gov (United States)

    Lange, M; Froese, M; Menk, S; Varju, J; Bastert, R; Blaum, K; López-Urrutia, J R Crespo; Fellenberger, F; Grieser, M; von Hahn, R; Heber, O; Kühnel, K-U; Laux, F; Orlov, D A; Rappaport, M L; Repnow, R; Schröter, C D; Schwalm, D; Shornikov, A; Sieber, T; Toker, Y; Ullrich, J; Wolf, A; Zajfman, D

    2010-05-01

    We report on the realization and operation of a fast ion beam trap of the linear electrostatic type employing liquid helium cooling to reach extremely low blackbody radiation temperature and residual gas density and, hence, long storage times of more than 5 min which are unprecedented for keV ion beams. Inside a beam pipe that can be cooled to temperatures <15 K, with 1.8 K reached in some locations, an ion beam pulse can be stored at kinetic energies of 2-20 keV between two electrostatic mirrors. Along with an overview of the cryogenic trap design, we present a measurement of the residual gas density inside the trap resulting in only 2 x 10(3) cm(-3), which for a room temperature environment corresponds to a pressure in the 10(-14) mbar range. The device, called the cryogenic trap for fast ion beams, is now being used to investigate molecules and clusters at low temperatures, but has also served as a design prototype for the cryogenic heavy-ion storage ring currently under construction at the Max-Planck Institute for Nuclear Physics.

  9. 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

  10. Surface nanostructuring of TiO2 thin films by ion beam irradiation

    International Nuclear Information System (INIS)

    Romero-Gomez, P.; Palmero, A.; Yubero, F.; Vinnichenko, M.; Kolitsch, A.; Gonzalez-Elipe, A.R.

    2009-01-01

    This work reports a procedure to modify the surface nanostructure of TiO 2 anatase thin films through ion beam irradiation with energies in the keV range. Irradiation with N + ions leads to the formation of a layer with voids at a depth similar to the ion-projected range. By setting the ion-projected range a few tens of nanometers below the surface of the film, well-ordered nanorods appear aligned with the angle of incidence of the ion beam. Slightly different results were obtained by using heavier (S + ) and lighter (B + ) ions under similar conditions

  11. Neutral beam injector for 475 keV MARS sloshing ions

    International Nuclear Information System (INIS)

    Goebel, D.M.; Hamilton, G.W.

    1983-01-01

    A neutral beam injector system which produces 5 MW of 475 keV D 0 neutrals continuously on target has been designed. The beamline is intended to produce the sloshing ion distribution required in the end plug region of the conceptual MARS tandem mirror commercial reactor. The injector design utilizes the LBL self-extraction negative ion source and Transverse Field Focusing (TFF) accelerator to generate a long, ribbon ion beam. A laser photodetachment neutralizer strips over 90% of the negative ions. Magnetic and neutron shield designs are included to exclude the fringe fields of the end plug and provide low activation by the neutron flux from the target plasma. The use of a TFF accelerator and photodetachment neutralizer produces a total system electrical efficiency of about 63% for this design

  12. 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.

  13. Simulating the ballistic effects of ion irradiation in the binary collision approximation: A first step toward the ion mixing framework

    International Nuclear Information System (INIS)

    Demange, G.; Antoshchenkova, E.; Hayoun, M.; Lunéville, L.; Simeone, D.

    2017-01-01

    Understanding ballistic effects induced by ion beam irradiation can be a key point for controlling and predicting the microstructure of irradiated materials. Meanwhile, the ion mixing framework suggests an average description of displacement cascades may be sufficient to estimate the influence of ballistic relocations on the microstructure. In this work, the BCA code MARLOWE was chosen for its ability to account for the crystal structure of irradiated materials. A first set of simulations was performed on pure copper for energies ranging from 0.5 keV to 20 keV. These simulations were validated using molecular dynamics (MD). A second set of simulations on AgCu irradiated by 1 MeV krypton ions was then carried out using MARLOWE only, as such energy is beyond reach for molecular dynamics. MARLOWE simulations are found to be in good agreement with experimental results, which suggests the predictive potential of the method.

  14. Simulating the ballistic effects of ion irradiation in the binary collision approximation: A first step toward the ion mixing framework

    Energy Technology Data Exchange (ETDEWEB)

    Demange, G., E-mail: gilles.demange@univ-rouen.fr [DEN/MDN/SRMA/LA2M, CEA Saclay, F-91191 Gif-sur-Yvette (France); Antoshchenkova, E. [DEN/MDN/SRMA/LA2M, CEA Saclay, F-91191 Gif-sur-Yvette (France); Hayoun, M. [LSI, École Polytechnique, CNRS, CEA Saclay, Université Paris-Saclay, F-91128 Palaiseau (France); Lunéville, L. [DEN/SERMA/LLPR, CEA Saclay, F-91191 Gif sur Yvette (France); Simeone, D. [DEN/MDN/SRMA/LA2M, CEA Saclay, F-91191 Gif-sur-Yvette (France)

    2017-04-01

    Understanding ballistic effects induced by ion beam irradiation can be a key point for controlling and predicting the microstructure of irradiated materials. Meanwhile, the ion mixing framework suggests an average description of displacement cascades may be sufficient to estimate the influence of ballistic relocations on the microstructure. In this work, the BCA code MARLOWE was chosen for its ability to account for the crystal structure of irradiated materials. A first set of simulations was performed on pure copper for energies ranging from 0.5 keV to 20 keV. These simulations were validated using molecular dynamics (MD). A second set of simulations on AgCu irradiated by 1 MeV krypton ions was then carried out using MARLOWE only, as such energy is beyond reach for molecular dynamics. MARLOWE simulations are found to be in good agreement with experimental results, which suggests the predictive potential of the method.

  15. Radiation defect distribution in silicon irradiated with 600 keV electrons

    International Nuclear Information System (INIS)

    Hazdra, P.; Dorschner, H.

    2003-01-01

    Low-doped n-type float zone silicon was irradiated with 600 keV electrons to fluences from 2x10 13 to 1x10 15 cm -2 . Radiation defects, their introduction rates and full-depth profiles were measured by two complementary methods - the capacitance deep level spectroscopy and the high-voltage current transient spectroscopy. Results show that, in the vicinity of the anode junction, the profile of vacancy-related defect centers is strongly influenced by electric field and an excessive generation of vacancies. In the bulk, the slope of the profile can be derived from the distribution of absorbed dose taking into the account the threshold energy necessary for Frenkel pair formation and the dependency of the defect introduction rate on electron energy

  16. Inactivation of catalase monolayers by irradiation with 100 keV electrons

    International Nuclear Information System (INIS)

    Hahn, M.; Seredynski, J.; Baumeister, W.

    1976-01-01

    A catalase monolayer adsorbed on a layer of arachidic acid deposited on a solid support was irradiated with 100 keV electrons simulating the conditions of electron microscopic imaging. Effective doses were calculated taking into account the angular and energy distribution of backscattered electrons. Enzymatic inactivation was chosen as the criterion for damage and was monitored by a rapid and quantifiable but nevertheless sensitive assay. Dose-response curves revealed that inactivation is a one-hit--multiple-target phenomenon, which is consistent with biochemical evidence for a cooperative function of subunits. The experimentally determined target size coincides fairly well with both calculated cross sections for inelastic interactions based on the atomic composition of catalase and with calculated cross sections for ionizing events based on the chemical bonds involved. This legitimates both types of calculations even for complex biomolecules

  17. 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

  18. Radiation blistering of niobium in sequence irradiated by helium ions with different energy

    International Nuclear Information System (INIS)

    Das, S.K.; Kaminskij, M.S.; Guseva, M.I.; Gusev, V.M.; Krasulin, Yu.L.; Martynenko, Yu.V.; Rozina, I.A.

    1977-01-01

    The results of the investigation of the blistering of the surface of polycrystalline niobium foils subjected to successive irradiation by helium ions of energies of 3 to 50 keV are reported. The critical doses of irradiation, the types of blisters and the rate of erosion were determined. A comparative analysis of the formation of blisters on cold-rolled and annealed niobium has been made. On cold-rolled niobium the blistering is mainly due to ions with energies of 3 to 80 keV, on annealed niobium of 100 to 500 keV. The erosion of cold-rolled niobium takes place through blisters formed by the action of helium ions with energies of the order of 45 keV, and that of annealed niobium, through helium ions with energies of 100 to 500 keV. The observed differences in the formation of blisters on niobium irradiated with helium ions of a wide range of energies are explained by the change in the diffusion kinetics of implanted ions having a uniform distribution across the thickness of the target

  19. Effects of keV electron irradiation on the avalanche-electron generation rates of three donors on oxidized silicon

    International Nuclear Information System (INIS)

    Sah, C.; Sun, J.Y.; Tzou, J.J.

    1983-01-01

    After keV electron beam irradiation of oxidized silicon, the avalanche-electron-injection generation rates and densities of the bulk compensating donor, the interface states, and the turnaround trap all increase. Heating at 200 0 C can anneal out these three donor-like traps, however, it cannot restore the generation rates back to their original and lower pre-keV electron irradiation values. The experimental results also indicate that all three traps may be related to the same mobile impurity species whose bonds are loosened by the keV electrons and then broken or released by the avalanche injected electrons

  20. Irradiation of tungsten with metallic diatomic molecular ions: atomic-resolution observations of depleted zones

    International Nuclear Information System (INIS)

    Pramanik, D.; Seidman, D.N.

    1982-08-01

    Direct evidence, on an atomic scale, is presented for the enhancement of damage production per projectile ion in diatomic metallic molecular ion (dimer) irradiations of tungsten as compared to monatomic metallic ion (monomer) irradiations. Irradiations were performed in situ at less than or equal to 10 K, in a field-ion microscope, employing 20 keV Ag + or W + monomer ions and the results are compared with 40 keV W 2 + or Ag 2 + dimer ion bombardments; the average energy per ion was 20 keV. First, in the near-surface region the depleted zones produced by the W 2 + dimer ions give rise to void-like contrast effects. The W + monomer ions do not produce this void-like damage. The existence of voids was explained employing a nucleation and diffusion-limited growth model which suggests that the growth can occur on a time scale -9 s, if the effective diffusivity of an atom in the fully-developed collision cascade is > 3 x 10 -4 cm 2 s -1 . Second, by counting the number of vacancies in individual depleted zones, produced by the different ions, it was demonstrated that the number of vacancies produced per incoming ion of the dimer is 1.55 times greater than the number of vacancies produced per monomer ion

  1. 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.

  2. Effect of ion irradiation on the structure and the surface topography of carbon fiber

    International Nuclear Information System (INIS)

    Ligacheva, E.A.; Galyaeva, L.V.; Gavrilov, N.V.; Belykh, T.A.; Ligachev, A.E.; Sokhoreva, V.V.

    2006-01-01

    The effect of C + ion irradiation (40 keV, 10 15 - 10 19 cm -2 ) on the structure and surface topography of high-module carbon fibers is investigated. Interplanar distance and internal stress values are found to be minimal at a radiation dose of 10 17 cm -2 , the height of a layer pack being practically unchanged. The relief of ion irradiated carbon fiber surface constitutes regularly repetitive valleys and ridges spaced parallel with the fiber axis [ru

  3. Making channeling visible: keV noble gas ion trails on Pt(111)

    Energy Technology Data Exchange (ETDEWEB)

    Redinger, A; Standop, S; Michely, T [II Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln (Germany); Rosandi, Y; Urbassek, H M, E-mail: urbassek@rhrk.uni-kl.de [Fachbereich Physik und Forschungszentrum OPTIMAS, Universitaet Kaiserslautern, Erwin-Schroedinger-Strasse, D-67663 Kaiserslautern (Germany)

    2011-01-15

    The impact of argon and xenon noble gas ions on Pt(111) in grazing incidence geometry are studied through direct comparison of scanning tunneling microscopy images and molecular dynamics simulations. The energy range investigated is 1-15 keV and the angles of incidence with respect to the surface normal are between 78.5{sup 0} and 88{sup 0}. The focus of the paper is on events where ions gently enter the crystal at steps and are guided in channels between the top most layers of the crystal. The trajectories of the subsurface channeled ions are visible as trails of surface damage. The mechanism of trail formation is analyzed using simulations and analytical theory. Significant differences between Xe{sup +} and Ar{sup +} projectiles in damage, in the onset energy of subsurface channeling as well as in ion energy dependence of trail length and appearance are traced back to the projectile and ion energy dependence of the stopping force. The asymmetry of damage production with respect to the ion trajectory direction is explained through the details of the channel shape and subchannel structure as calculated from the continuum approximation of the channel potential. Measured and simulated channel switching in directions normal and parallel to the surface as well as an increase of ions entering into channels from the perfect surface with increasing angles of incidence are discussed.

  4. Hardness enhancement and crosslinking mechanisms in polystyrene irradiated with high energy ion-beams

    International Nuclear Information System (INIS)

    Lee, E.H.; Rao, G.R.; Mansur, L.K.

    1996-01-01

    Surface hardness values several times larger than steel were produced using high energy ion beams at several hundred keV to MeV. High LET is important for crosslinking. Crosslinking is studied by analyzing hardness variations in response to irradiation parameter such as ion species, energy, and fluence. Effective crosslinking radii at hardness saturation are derived base on experimental data for 350 keV H + and 1 MeV Ar + irradiation of polystyrene. Saturation value for surface hardness is about 20 GPa

  5. Biological effect of 20 keV N+ ion implantation on Stevia rebaudianum

    International Nuclear Information System (INIS)

    Su Tingting; Yang Tingting; Ji Guohong; Xiang Xingjia; Chen Xuetao; Wang Yu; Wu Yaojin

    2010-01-01

    The germinability and gemination rate of Stevia rebaudianum seeds implanted with 20 keV N + ions in doses of 0 (CK), 100 x 2500, 400 x 2500 and 1000 x 2500 N + /cm 2 were studied by analyzing the differences in seed germinability and gemination rate between the groups. By statistical analysis, the germinability and gemination rate were affected at the level of α=0.05 by the implantation dose. The results showed that the germinability and gemination rate increased with the dose first and then decreased. At 400 x 2500 N + /cm 2 , the seeds had the largest germinability and the gemination rate. (authors)

  6. Electrical conduction in 100 keV Kr+ ion implanted poly (ethylene terephthalate)

    Science.gov (United States)

    Goyal, P. K.; Kumar, V.; Gupta, Renu; Mahendia, S.; Anita, Kumar, S.

    2012-06-01

    Polyethylene terephthalate (PET) samples have been implanted to 100 keV Kr+ ions at the fluences 1×1015-- 1×1016 cm-2. From I-V characteristics, the conduction mechanism was found to be shifted from ohmic to space charge limited conduction (SCLC) after implantation. The surface conductivity of these implanted samples was found to increase with increasing implantation dose. The structural alterations in the Raman spectra of implanted PET samples indicate that such an increase in the conductivity may be attributed to the formation of conjugated double bonded carbonaceous structure in the implanted layer of PET.

  7. Influence of ionic parameters on Auger emission by aluminium, induced by medium energy ions (2 to 5 keV)

    International Nuclear Information System (INIS)

    Celier, Dominique

    1987-01-01

    This research thesis reports the study of excitation collision mechanisms of metal atoms under irradiation by electrons with energy lower than or equal to 5 keV. After having outlined why this energy range is interesting, and indicated the different aluminium single crystals used in this study, the author describes the main involved emission phenomena related to the series of collisions due to emissions of different particles (electrons, photons, neutral or ionized atoms, backscattered primary ions). In the second part, the author recalls the characteristics of an Auger emission induced by ionic bombardment. Then, he presents the experimental installation which has been calibrated in order to allow the comparison of spectra induced under irradiations with different characteristics. Experimental results are reported and discussed. The cascade of binary shocks has also been examined. The scattering integral has been computed for several simple cases of collision, and allowed the definition of different conditions of excitation and ejection of excited atoms, depending on the fact that the ionizing shock is asymmetric or symmetric [fr

  8. Reflectance spectroscopy of PMMA implanted with 50 keV silicon ions

    Energy Technology Data Exchange (ETDEWEB)

    Florian, Bojana [Bulgarian Institute of Metrology, 2 Prof. P. Mutafchiev Str., 1797 Sofia (Bulgaria); Stefanov, Ivan [Department of Quantum Electronics, Faculty of Physics, Sofia University, 5 James Bourchier Blvd., 1164 Sofia (Bulgaria); Hadjichristov, Georgi [Institute of Solid State Physics, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria)

    2009-07-01

    Recently, the modification of the specular reflectivity of PMMA implanted with low-energy (50 keV) silicon ions was studied and nano-clusters formed in PMMA by Si{sup +} implantation were evidenced by Raman spectroscopy and electrical measurements. Further, the optical loss due to off-specular (diffuse) reflectivity of this ion-implanted polymer is also of practical interest for applications such as micro-optical lenses, diffraction gratings, Fresnel lenses, waveguides, etc. We examined both specular and diffuse reflectivity of Si{sup +} implanted PMMA in the UV-Vis-NIR. The effect from Si{sup +} implantation in the dose range 10{sup 14}-10{sup 17} ions/cm{sup 2} is linked to the structure formed in PMMA where the buried ion-implanted layer has a thickness up to 100 nm. As compared to the pristine PMMA, an enhancement of the reflectivity of Si{sup +} implanted PMMA is observed, that is attributed to the modification of the subsurface region of PMMA upon the ion implantation.

  9. Direct observation of the vacancy structure of depleted zones in tungsten ion irradiated at 100K

    International Nuclear Information System (INIS)

    Wei, C.Y.; Seidman, D.N.

    1978-12-01

    The structure of depleted zones (DZs) created by the in-situ irradiation of tungsten specimens, at 10 0 K, with 30 keV W + , Mo + or Cr + ions has been studied by field-ion microscopy. As the mass of the 30 keV ion was decreased the following observations were made: (1) the spatial extent of the DZs increased; (2) the vacancy concentration within the DZs decreased; (3) the fraction of isolated monovacancies increased; and (4) subcascades formed within the DZs

  10. Comparison of secondary ion emission induced in silicon oxide by MeV and KeV ion bombardment

    International Nuclear Information System (INIS)

    Allali, H.; Nsouli, B.; Thomas, J.P.; Szymczak, W.; Wittmaack, K.

    1993-09-01

    The surface and near-surface composition of SiO 2 layers, has been investigated by negative secondary ion emission mass spectrometry (SIMS) using MeV and KeV ion bombardment in combination with time-of-flight (TOF) mass analysis. The spectra recorded in the mass range 0-100 u are dominated by surface impurities, notably hydrocarbons and silicon polyanions incorporating H and OH entities. The characteristic (fragmentation) patterns are quite different for light and high-velocity ion impact. In high-velocity TOF-SIMS analysis of P-doped layers, prepared by chemical vapour deposition (CVD), the mass lines at 63 and 79 u are very prominent and appear to correlate with the phosphorus concentration (PO 2 and PO 3 , respectively). It is shown, however, that for unambiguous P analysis one has to use dynamic SIMS or high mass resolution. (author) 11 refs., 5 figs

  11. 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)

  12. Moessbauer study of defects in molybdenum and chromium irradiated with ions

    International Nuclear Information System (INIS)

    Troyan, V.A.; Bogdanov, V.V.; Ivanyushkin, E.M.; Pen'kov, Yu.P.

    1980-01-01

    Effects of ion irradiation of monocrystalline molybdenum and polycrystalline chromium with Co-57 impurity were studied by Moessbauer effect. Molybdenum specimens were irradiated by He + ions at accelerators with 40 keV energy. Chromium specimens were irradiated by hydrogen ions with 1.2 MeV energy up to integral 2x10 17 -2x10 19 ion/cm 2 doses. It is shown, that defect introduction into the source matrix by irradiation results in change of gamma-resonance line form and effect value. The observed effects of defect influence on spectrum parameters are discussed. It is concluded, that study of Moessbauer spectra parameters of diluted Co-57 solutions in matrices of different metals permits to determine dynamics of movement of impurity atoms and defects in metals irradiated with ions [ru

  13. Thermal desorption spectroscopy of boron/carbon films after keV deuterium irradiation

    International Nuclear Information System (INIS)

    Yamaki, T.; Gotoh, Y.; Ando, T.; Jimbou, R.; Ogiwara, N.; Saidoh, M.

    1994-01-01

    Thermal desorption spectroscopy (TDS) of D 2 and CD 4 was done on boron/carbon films (B/(B+C)=0-74%), after 3 keV D 3 + irradiation to 4.5x10 17 D/cm 2 at 473 K. The D 2 desorption peaks were observed at 1050, 850 and 650 K. For a sputter B/C film (0%), only the 1050 K peak was observed. With increasing boron concentration to 3%, a sharp peak appeared at 850 K, the intensity of which was found to increase with increasing boron concentration to 23%, and then to decrease at 74%. The 650 K shoulder, which was observed for high boron concentration specimens, was speculated to be deuterium trapped by boron atoms in the boron clusters. The relative amount of CD 4 desorption was found to decrease with increasing boron concentration, which was attributed to the decrease in the trapped deuterium concentration in the implantation layer at temperatures at which CD 4 desorption proceeds. ((orig.))

  14. Dual ion beam irradiation system for in situ observation with electron microscope

    International Nuclear Information System (INIS)

    Tsukamoto, Tetuo; Hojou, Kiiti; Furuno, Sigemi; Otsu, Hitosi; Izui, Kazuhiko.

    1993-01-01

    We have developed a new in situ observation system for dynamic processes under dual ion beam irradiation. The system consists of a modified 400 keV analytical electron microscope (JEOL, JEM-4000FX) and two 40 kV ion beam accelerators. This system allows evaluation of microscopic changes of structure and chemical bonding state of materials in the dynamic processes under two kinds of ion beam irradiations, that is required for the simulation test of the first wall of nuclear fusion reactors onto which He + , H + , and H 2 + ions are irradiated simultaneously. These two ion accelerators were equipped symmetrically both sides of the electron microscope and individually controlled. Each ion beam extracted from a duo-plasmatron ion gun is bent downward by an angle of 30deg with a mass-separating magnet, and introduced into specimen chamber of the electron microscope. Inside the specimen chamber the beam is deflected again by an angle of 30deg with an electrostatic prism so as to be incident on the specimen surface. Finally, two ion beams from both side are incident on the specimen surface at an angle of 60deg. The maximum ion current density of helium is more than 250μA/cm 2 at the specimen at an ion energy of 17 keV. Images of the electron microscope during dual ion beam irradiation are observed through a TV camera and recorded with a VTR. (author)

  15. A 2-100 keV, UHV ion impact spectrometer for ion-solid interaction studies

    International Nuclear Information System (INIS)

    Berg, J.A. Van den; Armour, D.G.; Verheij, L.K.

    1978-01-01

    A 2 to 100 keV ion accelerator has been constructed as part of an ion impact spectrometer in which a number of analytical techniques have been combined to allow a comprehensive study of the interaction of low- and medium-energy ions with solids to be carried out under carefully controlled conditions. The overall requirements of the ion beam system in terms of ion species, beam purity, uniformity, energy spread and intensity were dictated by the interest in carrying out low-energy ion scattering, Rutherford back-scattering and thermal desorption experiments. The accelerator design utilises the principle of low-energy extraction and mass analysis, and post-acceleration up to the required high energy. The ions are produced in a duoplasmatron ion source and a parallel beam is obtained after mass selection, utilising a quadrupole triplet lens in conjunction with a 60 0 stigmatic focusing magnetic analyser. Proton and rare gas ion beams of 1 to 100 nA are routinely obtained on target. The 54 cm diameter, UHV target chamber is pumped by a 270 1 s -1 turbo-molecular pump in conjunction with an in-line titanium sublimator, and typical base pressures of 1 to 4 x 10 -11 Torr are achieved. The target is supported in a precision, three-axis goniometer and the detection system, at present comprising a 90 mm mean diameter hemispherical energy analyser and channel electron multiplier, is mounted on a two-axis manipulator. Preliminary measurements using the system have employed the low-energy ion scattering technique to study the oxidation of a Ni(110) surface. (author)

  16. 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)

  17. 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.

  18. 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.

  19. Study of SiO{sub 2} surface sputtering by a 250-550 keV He{sup +} ion beam during high-resolution Rutherford backscattering measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kusanagi, Susumu [Materials Analysis Laboratory, Advanced Design Technology Center, Sony Corporation, 4-16-1 Okata Atsugi-shi, Kanagawa 243-0021 (Japan)]. E-mail: susumu.kusanagi@jp.sony.com; Kobayashi, Hajime [Materials Analysis Laboratory, Advanced Design Technology Center, Sony Corporation, 4-16-1 Okata Atsugi-shi, Kanagawa 243-0021 (Japan)

    2006-08-15

    Decreases in oxygen signal intensities in spectra of high-resolution Rutherford backscattering spectrometry (HRBS) were observed during measurements on a 5-nm thick SiO{sub 2} layer on a Si substrate when irradiated by 250-550 keV He{sup +} ions. Shifts in an implanted arsenic profile in a 5-nm thick SiO{sub 2}/Si substrate were also observed as a result of He{sup +} ion irradiation. These results lead to the conclusion that the SiO{sub 2} surface was sputtered by He{sup +} ions in this energy range.

  20. Isothermal annealing of silicon implanted with 50 keV 10B ions

    International Nuclear Information System (INIS)

    Weidner, B.; Zaschke, G.

    1974-01-01

    Isothermal annealing characteristics of silicon implanted with boron were measured and compared with calculated results. Implantation was performed with 50 keV 10 B ions in the dose range of 7.5 x 10 12 cm -2 to 2.0 x 10 15 cm -2 . Annealing temperatures ranged from 700 to 900 0 C. Maximum annealing time was 10 4 minutes. Annealing time strongly increases with increasing dose and decreasing temperature. Assuming that there is only one activation energy the isothermal annealing curves of constant dose and different temperatures were combined to a reduced annealing curve and the reduced isothermal annealing curve calculated. Starting from first order kinetics, considering the doping profile of boron in silicon and assuming a depth-dependent decay constant the experimentally determined annealing curves could be easily described over the total dose and time range

  1. Scattering of light keV ions from amorphous and crystalline solid surfaces

    International Nuclear Information System (INIS)

    Robinson, J.E.; Kwok, K.K.; Thompson, D.A.

    1976-01-01

    Total reflection coefficients (R), backscattered energy fractions (γ), and backscattered energy spectra are evaluated using a binary collision Monte Carlo technique for a variety of light ions (H, D, T, He) in the energy range 0.25-8 keV, incident on amorphous targets (C, Fe, Nb). The scattering is also evaluated for H on Nb for a range of incident angles and two electronic stopping values. The average scattered energy per reflected particle and the backscattered energy spectra are found to vary in a universal manner as a function of the reflection coefficient between the Rutherford high energy limit and a low energy multiple collision limit. Single crystal effects are also briefly discussed using a diffusional dechanneling model. (Auth.)

  2. 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

  3. Morphology variation, composition alteration and microstructure changes in ion-irradiated 1060 aluminum alloy

    Science.gov (United States)

    Wan, Hao; Si, Naichao; Wang, Quan; Zhao, Zhenjiang

    2018-02-01

    Morphology variation, composition alteration and microstructure changes in 1060 aluminum irradiated with 50 keV helium ions were characterized by field emission scanning electron microscopy (FESEM) equipped with x-ray elemental scanning, 3D measuring laser microscope and transmission electron microscope (TEM). The results show that, helium ions irradiation induced surface damage and Si-rich aggregates in the surfaces of irradiated samples. Increasing the dose of irradiation, more damages and Si-rich aggregates would be produced. Besides, defects such as dislocations, dislocation loops and dislocation walls were the primary defects in the ion implanted layer. The forming of surface damages were related with preferentially sputtering of Al component. While irradiation-enhanced diffusion and irradiation-induced segregation resulted in the aggregation of impurity atoms. And the aggregation ability of impurity atoms were discussed based on the atomic radius, displacement energy, lattice binding energy and surface binding energy.

  4. 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)

  5. Influence of ion irradiation induced defects on mechanical properties of copper nanowires

    International Nuclear Information System (INIS)

    Li, Weina; Sun, Lixin; Xue, Jianming; Wang, Jianxiang; Duan, Huiling

    2013-01-01

    The mechanical properties of copper nanowires irradiated with energetic ions have been investigated by using molecular dynamics simulations. The Cu ions with energies ranging from 0.2 to 8.0 keV are used in our simulation, and both the elastic properties and yields under tension and compression are analyzed. The results show that two kinds of defects, namely point defects and stacking faults, appear in the irradiated nanowires depending on the incident ion energy. The Young modulus is significantly reduced by the ion irradiation, and the reduction magnitude depends on the vacancy number, which is determined by the ion energy. Moreover, the irradiated nanowires yield at a smaller strain, compared with the unirradiated nanowire. The mechanism for these changes are also discussed

  6. Surface damage and gas trapping profile measurements in copper during 20 kev He+ irradiation

    International Nuclear Information System (INIS)

    Terreault, B.; Veilleux, G.

    1980-01-01

    Surface damage due to 20 keV he + irradiation of OFHC Cu was studied by optical and scanning electron microscopy, and by gas trapping profile measurements with proton backscattering and elastic recoil detection. Both annealed (1 h at 773 K) and unannealed Cu were implanted, at 300 K (0.22Tsub(m)) and 500 K(0.37 Tsub(m)), up to fluences of 3 x 10 18 cm -2 . Additional results with thin (1 μm) evaporated films and stressed cold-rolled foils (3 μm) were obtained. At 500 K in bulk OFHC Cu pores and/or large (approx. 1μm) but scattered blisters appear; at 300 K in bulk or thin film Cu blisters are large and abundant. In all these cases a very large (>=1.5 x 10 1 7 cm -2 ) and sudden release of deeply implanted helium takes place, leading to a depleted profile at a depth of about 90 nm (approx. Rsub(p)). In contrast in cold-rolled foils the blisters are small (approx. 0.4 μm) and the profiles are undepleted. These results are explained by fissuration of helium-pressurized cavities. At high fluence blisters disappear, leaving a porous structure at 500 K and a rough micro-relief at 300 K; the helim profiles are flat and very wide (2-3 Rsub(p)). Blister disappearance, absence of flaking, and porous structure are discussed in terms of the width of the profiles and the formation of a helium-saturated, highly damaged (recrystallized), and permeable layer. (orig.)

  7. Thermal release behavior of helium from copper irradiated by He+ ions

    International Nuclear Information System (INIS)

    Yamauchi, T.; Tokura, S.; Yamanaka, S.; Miyake, M.

    1988-01-01

    Thermal release behavior of helium from copper irradiated by 20 keV He + ions with a dose of 2x10 15 to 3x10 17 ions/cm 2 has been studied. The shape of the thermal release curves and thew number of helium release peaks strongly depend on the irradiation dose. Results from SEM surface observastion after post-irradiation heating suggested that helium release caused various surface damages such as blistering, flaking, and hole formation. Helium release resulting in small holes was analyzed and helium bubble growth mechanisms are discussed. (orig.)

  8. Enhancement of CNT-based filters efficiency by ion beam irradiation

    Science.gov (United States)

    Elsehly, Emad M.; Chechenin, N. G.; Makunin, A. V.; Shemukhin, A. A.; Motaweh, H. A.

    2018-05-01

    It is shown in the report that disorder produced by ion beam irradiation can enhance the functionality of the carbon nanotubes. The filters of pressed multiwalled carbon nanotubes (MWNTs) were irradiated by He+ ions of the energy E = 80 keV with the fluence 2 × 1016 ion/cm2. The removal of manganese from aqueous solutions by using pristine and ion beam irradiated MWNTs filters was studied as a function of pH, initial concentration of manganese in aqueous solution, MWNT mass and contact time. The filters before and after filtration were characterized by Raman (RS) and energy dispersive X-ray spectroscopy (EDS) techniques to investigate the deposition content in the filter and defect formation in the MWNTs. The irradiated samples showed an enhancement of removal efficiency of manganese up to 97.5% for 10 ppm Mn concentration, suggesting that irradiated MWNT filter is a better Mn adsorbent from aqueous solutions than the pristine one. Radiation-induced chemical functionalization of MWNTs due to ion beam irradiation, suggesting that complexation between the irradiated MWNTs and manganese ions is another mechanism. This conclusion is supported by EDS and RS and is correlated with a larger disorder in the irradiated samples as follows from RS. The study demonstrates that ion beam irradiation is a promising tool to enhance the filtration efficiency of MWNT filters.

  9. Experimental modeling of high burn-up structure in SIMFUEL with ion irradiation

    International Nuclear Information System (INIS)

    Baranov, V.; Isaenkova, M.; Lunev, A.; Tenishev, A.; Khlunov, A.

    2013-01-01

    Experiments are conducted to simulate high burn-up structure in accelerator conditions. Three ion irradiation schemes are used: 1. Xe 27+ 160 MeV up to 5x10 15 cm -2 (thermal spikes). 2. Xe 16+ 320 keV up to 1x10 17 cm -2 (collision cascades). 3. He + 20 keV up to 5,5x10 17 cm -2 (implantation stage). Structural characterization performed by scanning electron microscopy, X-ray analysis and atomic force microscopy revealed prominent grain refinement in case of Xe 27+ irradiation. Artificial energy variation for incident ions showed varying size of subgrains. At maximum energy of incident ions, subgrain size amounts ∼ 320 nm. Moving to the edge of irradiated region changes the size to ∼ 170 nm. Typical size of coherent scattering regions matches subgrain size for high-energy irradiation. Low-energy irradiation results in less significant structural changes: flaky structure at random sites for samples irradiated with low-energy xenon ions and bubble nucleation for helium irradiation. Dislocation density increases significantly, and it is shown that a single fluence dependence exists for low- and high-energy irradiation. (authors)

  10. Magnetic properties changes of MnAs thin films irradiated with highly charged ions

    OpenAIRE

    Trassinelli , Martino; Gafton , V.; Eddrief , Mahmoud; Etgens , Victor H.; Hidki , S.; Lacaze , Emmanuelle; Lamour , Emily; Luo , X.; Marangolo , Massimiliano; Merot , Jacques; Prigent , Christophe; Reuschl , Regina; Rozet , Jean-Pierre; Steydli , S.; Vernhet , Dominique

    2013-01-01

    International audience; We present the first investigation on the effect of highly charged ion bombardment on a manganese arsenide thin film. The MnAs films, 150~nm thick, are irradiated with 90 keV Ne$^{9+}$ ions with a dose varying from $1.6\\times10^{12}$ to $1.6\\times10^{15}$~ions/cm$^2$. The structural and magnetic properties of the film after irradiation are investigated using different techniques, namely, X-ray diffraction, magneto-optic Kerr effect and magnetic force microscope. Prelim...

  11. Charge yield for cobalt-60 and 10-keV x-ray irradiations of MOS devices

    International Nuclear Information System (INIS)

    Shaneyfelt, M.R.; Fleetwood, D.M.; Schwank, J.R.; Hughes, K.L.

    1991-01-01

    In this paper the radiation response of MOS devices exposed to 60 Co and low-energy (∼10 keV) x-ray irradiation is evaluated as a function of electric field during exposure. Improved charge yield estimates are obtained for 60 Co irradiations at fields below 1 MV/cm by matching voltage shifts due to oxide-trap and interface-trap charge to an E -0.55 electric field dependence. Combining these improved charge yield estimates and calculated dose enhancement factors, the relative response of x-ray to 60 Co irradiations is accurately predicted for oxide electric fields from 0.03 MV/cm to 5.0 MV/cm. The ability to predict the relative response of x-ray to 60 Co irradiations should speed acceptance of x-ray testers as a hardness assurance tool

  12. Beam position monitor R&D for keV ion beams

    CERN Document Server

    Naveed, S; Nosych, A; Søby,L

    2013-01-01

    Beams of cooled antiprotons at keV energies shall be provided by the Ultra-low energy Storage Ring (USR) at the Facility for Low energy Antiproton and Ion Research (FLAIR) and the Extra Low ENergy Antiproton ring (ELENA) at CERN's Antiproton Decelerator (AD) facility. Both storage rings put challenging demands on the beam position monitoring (BPM) system as their capacitive pick-ups should be capable of determining the beam position of beams at low intensities and low velocities, close to the noise level of state-of-the-art electronics. In this contribution we describe the design and anticipated performance of BPMs for low-energy ion beams with a focus on the ELENA orbit measurement systems. We also present the particular challenges encountered in the numerical simulation of pickup response at very low beta values. Finally, we provide an outlook on how the implementation of faster algorithms for the simulation of BPM characteristics could potentially help speed up such studies considerably.

  13. 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.

  14. "Trampoline" ejection of organic molecules from graphene and graphite via keV cluster ions impacts

    Science.gov (United States)

    Verkhoturov, Stanislav V.; Gołuński, Mikołaj; Verkhoturov, Dmitriy S.; Geng, Sheng; Postawa, Zbigniew; Schweikert, Emile A.

    2018-04-01

    We present the data on ejection of molecules and emission of molecular ions caused by single impacts of 50 keV C602+ on a molecular layer of deuterated phenylalanine (D8Phe) deposited on free standing, 2-layer graphene. The projectile impacts on the graphene side stimulate the abundant ejection of intact molecules and the emission of molecular ions in the transmission direction. To gain insight into the mechanism of ejection, Molecular Dynamic simulations were performed. It was found that the projectile penetrates the thin layer of graphene, partially depositing the projectile's kinetic energy, and molecules are ejected from the hot area around the hole that is made by the projectile. The yield, Y, of negative ions of deprotonated phenylalanine, (D8Phe-H)-, emitted in the transmission direction is 0.1 ions per projectile impact. To characterize the ejection and ionization of molecules, we have performed the experiments on emission of (D8Phe-H)- from the surface of bulk D8Phe (Y = 0.13) and from the single molecular layer of D8Phe deposited on bulk pyrolytic graphite (Y = 0.15). We show that, despite the similar yields of molecular ions, the scenario of the energy deposition and ejection of molecules is different for the case of graphene due to the confined volume of projectile-analyte interaction. The projectile impact on the graphene-D8Phe sample stimulates the collective radial movement of analyte atoms, which compresses the D8Phe layer radially from the hole. At the same time, this compression bends and stretches the graphene membrane around the hole thus accumulating potential energy. The accumulated potential energy is transformed into the kinetic energy of correlated movement upward for membrane atoms, thus the membrane acts as a trampoline for the molecules. The ejected molecules are effectively ionized; the ionization probability is ˜30× higher compared to that obtained for the bulk D8Phe target. The proposed mechanism of ionization involves tunneling of

  15. "Trampoline" ejection of organic molecules from graphene and graphite via keV cluster ions impacts.

    Science.gov (United States)

    Verkhoturov, Stanislav V; Gołuński, Mikołaj; Verkhoturov, Dmitriy S; Geng, Sheng; Postawa, Zbigniew; Schweikert, Emile A

    2018-04-14

    We present the data on ejection of molecules and emission of molecular ions caused by single impacts of 50 keV C 60 2+ on a molecular layer of deuterated phenylalanine (D8Phe) deposited on free standing, 2-layer graphene. The projectile impacts on the graphene side stimulate the abundant ejection of intact molecules and the emission of molecular ions in the transmission direction. To gain insight into the mechanism of ejection, Molecular Dynamic simulations were performed. It was found that the projectile penetrates the thin layer of graphene, partially depositing the projectile's kinetic energy, and molecules are ejected from the hot area around the hole that is made by the projectile. The yield, Y, of negative ions of deprotonated phenylalanine, (D8Phe-H) - , emitted in the transmission direction is 0.1 ions per projectile impact. To characterize the ejection and ionization of molecules, we have performed the experiments on emission of (D8Phe-H) - from the surface of bulk D8Phe (Y = 0.13) and from the single molecular layer of D8Phe deposited on bulk pyrolytic graphite (Y = 0.15). We show that, despite the similar yields of molecular ions, the scenario of the energy deposition and ejection of molecules is different for the case of graphene due to the confined volume of projectile-analyte interaction. The projectile impact on the graphene-D8Phe sample stimulates the collective radial movement of analyte atoms, which compresses the D8Phe layer radially from the hole. At the same time, this compression bends and stretches the graphene membrane around the hole thus accumulating potential energy. The accumulated potential energy is transformed into the kinetic energy of correlated movement upward for membrane atoms, thus the membrane acts as a trampoline for the molecules. The ejected molecules are effectively ionized; the ionization probability is ∼30× higher compared to that obtained for the bulk D8Phe target. The proposed mechanism of ionization involves

  16. Structural and electrical evolution of He ion irradiated hydrocarbon films observed by conductive atomic force microscopy

    International Nuclear Information System (INIS)

    Fan, Hongyu; Yang, Deming; Sun, Li; Yang, Qi; Niu, Jinhai; Bi, Zhenhua; Liu, Dongping

    2013-01-01

    Polymer-like hydrocarbon films are irradiated with 100 keV He ion at the fluences of 1.0 × 10 15 –1.0 × 10 17 ions/cm 2 or at the irradiation temperature ranging from 25 to 600 °C. Conductive atomic force microscopy (CAFM) has been used to evaluate the nanoscale electron conducting properties of these irradiated hydrocarbon films. Nanoscale and conducting defects have been formed in the hydrocarbon films irradiated at a relatively high ion fluence (1.0 × 10 17 ions/cm 2 ) or an elevated sample temperature. Analysis indicates that He ion irradiation results in the evolution of polymer-like hydrocarbon into a dense structure containing a large fraction of sp 2 carbon clusters. The sp 2 carbon clusters formed in irradiated hydrocarbon films can contribute to the formation of filament-like conducting channels with a relatively high local field-enhancing factor. Measurements indicate that the growth of nanoscale defects due to He ion irradiation can result in the surface swelling of irradiated hydrocarbon films at a relatively high ion fluences or elevated temperature

  17. Structural and electrical evolution of He ion irradiated hydrocarbon films observed by conductive atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Hongyu [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Yang, Deming [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022 (China); Sun, Li [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Physics, Liaoning Normal University, Dalian 116023 (China); Yang, Qi; Niu, Jinhai; Bi, Zhenhua [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Liu, Dongping, E-mail: dongping.liu@dlnu.edu.cn [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Fujian Key Laboratory for Plasma and Magnetic Resonance, Department of Electronic Science, Aeronautics, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China)

    2013-10-01

    Polymer-like hydrocarbon films are irradiated with 100 keV He ion at the fluences of 1.0 × 10{sup 15}–1.0 × 10{sup 17} ions/cm{sup 2} or at the irradiation temperature ranging from 25 to 600 °C. Conductive atomic force microscopy (CAFM) has been used to evaluate the nanoscale electron conducting properties of these irradiated hydrocarbon films. Nanoscale and conducting defects have been formed in the hydrocarbon films irradiated at a relatively high ion fluence (1.0 × 10{sup 17} ions/cm{sup 2}) or an elevated sample temperature. Analysis indicates that He ion irradiation results in the evolution of polymer-like hydrocarbon into a dense structure containing a large fraction of sp{sup 2} carbon clusters. The sp{sup 2} carbon clusters formed in irradiated hydrocarbon films can contribute to the formation of filament-like conducting channels with a relatively high local field-enhancing factor. Measurements indicate that the growth of nanoscale defects due to He ion irradiation can result in the surface swelling of irradiated hydrocarbon films at a relatively high ion fluences or elevated temperature.

  18. 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

  19. Guided transmission of 3 keV Ne sup 7 sup + ions through nanocapillaries etched in a PET polymer

    CERN Document Server

    Stolterfoht, N; Hellhammer, R; Pesic, Z D; Fink, D; Petrov, A; Sulik, B

    2003-01-01

    We measured the transmission of 3 keV Ne sup 7 sup + ions through capillaries of 100 nm diameter and 10 mu m length produced by etching ion tracks in a polyethylene terephthalate polymer foil. The foils were tilted up to +-25 deg. for which the incident ions are forced to interact with the capillary surface. The majority of Ne sup 7 sup + ions were found to survive the transmission in their initial charge state. For tilted foils the angular distributions of the transmitted particles indicate propagation of the Ne sup 7 sup + ions parallel to the capillary axis. This capillary guiding of the Ne sup 7 sup + ion provides evidence that part of the ions deposit charges within the capillaries in a self-organizing process so that a considerable fraction of the ions is transmitted through the capillaries. A non-linear model is introduced to describe the essential features of the capillary guiding.

  20. Energy Reflection Coefficients for 5-10 keV He Ions Incident on Au, Ag, and Cu

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Littmark, U.

    1978-01-01

    The calorimetric deuterium-film method was used for measurements of the energy reflection coefficient γ for normal incidence of 5-10 keV He ions on Cu, Ag and Au. A theoretical calculation of γ by means of transport theory gives fair agreement with the experimental results. The experimental data...... the experimental and theoretical results for the He ions are in acceptable agreement with other experimental and theoretical results. For He ions, the experimental γ-values are 20-30% above the values for hydrogen ions for the same value of ε...

  1. 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

  2. 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.

  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. Synthesis of gold and silver nanoparticles by electron irradiation at 5-15 keV energy

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, S K; Bogle, K A; Dhole, S D; Bhoraskar, V N [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune-411007 (India)

    2007-04-04

    Thin coatings ({approx}10 {mu}m) made from a mixture of polyvinyl alcohol (PVA) and HAuCl{sub 4} or PVA and AgNO{sub 3} on quartz plates were irradiated with 5-15 keV electrons, at room temperature. The electron energy was varied from coating to coating in the range of 5-15 keV, but electron fluence was kept constant at {approx}10{sup 15} e cm{sup -2}. Samples were characterized by the UV-vis, XRD, SEM and TEM techniques. The plasmon absorption peaks at {approx}511 and {approx}442 nm confirmed the formation of gold and silver nanoparticles in the respective electron-irradiated coatings. The XRD, SEM and TEM measurements reveal that the average size of the particles could be tailored in the range of 130-50 nm for gold and from 150-40 nm for silver by varying the electron energy in the range of 5-15 keV. These particles of gold and silver embedded in the polymer could also be separated by dissolving the coatings in distilled water.

  5. Ion irradiation and thermal cycling tests of TiC coatings

    International Nuclear Information System (INIS)

    Yamanaka, S.; Ohara, H.; Son, P.; Miyake, M.

    1984-01-01

    Ion irradiation of TiC coatings prepared by diffusion annealing was performed with 20-40 keV He + ions for different doses at room temperature. The polished TiCsub(0.99) coatings irradiated with 40 keV He + ions showed the surface damage and erosion due to blistering and exfoliation above a dose of 1.8x10 17 ions/cm 2 , whereas no change in the surface morphology could be detected for the as-prepared coatings up to a dose of 1.4x10 18 ions/cm 2 . The results suggested that surface erosion due to blistering can be effectively reduced on the rough surface of the as-prepared TiC coating. The average blister diameter in the polished TiCsub(0.99) coating increased with increasing projectile energy. For the 40 keV He + ion irradiation of the polished TiCsub(0.5) coatings, general features in blisters were similar to those observed for the TiCsub(0.99) coatings, but the critical dose for blistering shifted to a higher value in comparison with the polished TiCsub(0.99) coating. Thermal cycling between 500 and 1200 0 C caused serious surface damage for the TiCsub(0.99) coating irradiated with 40 keV He + ions below the critical dose for blistering, while the coating with surface damage due to blistering showed no significant change in the surface topography after thermal cycling. (orig.)

  6. 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)

  7. A study of defect cluster formation in vanadium by heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sekimura, Naoto; Shirao, Yasuyuki; Morishita, Kazunori [Tokyo Univ. (Japan)

    1996-10-01

    Formation of defect clusters in thin foils of vanadium was investigated by heavy ion irradiation. In the very thin region of the specimens less than 20 nm, vacancy clusters were formed under gold ion irradiation, while very few clusters were detected in the specimens irradiated with 200 and 400 keV self-ions up to 1 x 10{sup 16} ions/m{sup 2}. The density of vacancy clusters were found to be strongly dependent on ion energy. Only above the critical value of kinetic energy transfer density in vanadium, vacancy clusters are considered to be formed in the cascade damage from which interstitials can escape to the specimen surface in the very thin region. (author)

  8. Effects of ion irradiation on the residual stresses in Cr thin films

    International Nuclear Information System (INIS)

    Misra, A.; Fayeulle, S.; Kung, H.; Mitchell, T.E.; Nastasi, M.

    1998-01-01

    Cr films sputtered onto {100}thinspSi substrates at room temperature were found to be under residual tension, as revealed by wafer curvature measurements. A 150 nm thick Cr film was bombarded with 300 keV Ar ions after deposition. The intrinsic residual tensile stress increased slightly and then decreased with further increase in the ion dose. For ion doses >1x10 15 thinspions/cm 2 , the stress in the film became compressive and increased with increasing dose. Transmission electron microscopy revealed that the grain boundaries in as-deposited Cr have columnar porosity. A Cr film, ion irradiated to a dose of 5x10 15 thinspions/cm 2 , showed no grain boundary porosity. The changes in the residual stress during ion irradiation are explained by considering Ar incorporation in the film and the manner in which irradiation may change the interatomic distances and forces. copyright 1998 American Institute of Physics

  9. 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.

  10. 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

  11. 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)

  12. Thermal desorption spectroscopy of pyrolytic graphite cleavage faces after keV deuterium irradiation at 330-1000 K

    International Nuclear Information System (INIS)

    Gotoh, Y.; Yamaki, T.; Tokiguchi, K.

    1992-01-01

    Thermal desorption spectroscopy (TDS) measurements were made on D 2 and CD 4 from surface layers of pyrolytic graphite cleavage faces after 3 keV D + 3 irradiation to 1.5 x 10 18 D/cm 2 at irradiation temperatures from 330 to 1000 K. Thermal desorption of both D 2 and CD 4 was observed to rise simultaneously at around 700 K. The D 2 peak was found at T m = 900-1000 K, while the CD 4 peak appeared at a lower temperature, 800-840 K. The T m for the D 2 TDS increased, while that for the CD 4 decreased with increasing irradiation temperature. These results obviously indicate that the D 2 desorption is detrapping/recombination limited, while the CD 4 desorption is most likely to be diffusion limited. The amount of thermally desorbed D 2 after the D + irradiation was observed to monotonously decrease as the irradiation temperature was increased from 330 to 1000 K. These tendencies agreed with previous results for the irradiation temperature dependencies of both C1s chemical shift (XPS) and the interlayer spacing, d 002 (HRTEM), on the graphite basal face. (orig.)

  13. Development and characterization of semiconductor ion detectors for plasma diagnostics in the range over 0.3 keV

    Science.gov (United States)

    Cho, T.; Sakamoto, Y.; Hirata, M.; Kohagura, J.; Makino, K.; Kanke, S.; Takahashi, K.; Okamura, T.; Nakashima, Y.; Yatsu, K.; Tamano, T.; Miyoshi, S.

    1997-01-01

    For the purpose of plasma-ion-energy analyses in a wide-energy range from a few hundred eV to hundreds of keV, upgraded semiconductor detectors are newly fabricated and characterized using a test-ion-beam line from 0.3 to 12 keV. In particular, the detectable lowest-ion energy is drastically improved at least down to 0.3 keV; this energy is one to two orders-of-magnitude better than those for commercially available Si-surface-barrier diodes employed for previous plasma-ion diagnostics. A signal-to-noise ratio of two to three orders-of-magnitude better than that for usual metal-collector detectors is demonstrated for the compact-sized semiconductor along with the availability of the use under conditions of a good vacuum and a strong-magnetic field. Such characteristics are achieved due to the improving methods of the optimization of the thicknesses of a Si dead layer and a SiO2 layer, as well as the nitrogen-doping technique near the depletion layer along with minimizing impurity concentrations in Si. Such an upgraded capability of an extremely low-energy-ion detection with the low-noise characteristics enlarges research regimes of plasma-ion behavior using semiconductor detectors not only in the divertor regions of tokamaks but in wider spectra of open-field plasma devices including tandem mirrors. An application of the semiconductor ion detector for plasma-ion diagnostics is demonstrated in a specially designed ion-spectrometer structure.

  14. Order-disorder phase transformation in ion-irradiated rare earth sesquioxides

    International Nuclear Information System (INIS)

    Tang, M.; Valdez, J. A.; Sickafus, K. E.; Lu, P.

    2007-01-01

    An order-to-disorder (OD) transformation induced by ion irradiation in rare earth (RE) sesquioxides, Dy 2 O 3 , Er 2 O 3 , and Lu 2 O 3 , was studied using grazing incidence x-ray diffraction and transmission electron microscopy. These sesquioxides are characterized by a cubic C-type RE structure known as bixbyite. They were irradiated with heavy Kr ++ ions (300 keV) and light Ne + ions (150 keV) at cryogenic temperature (∼120 K). In each oxide, following a relatively low ion irradiation dose of ∼2.5 displacements per atom, the ordered bixbyite structure was transformed to a disordered, anion-deficient fluorite structure. This OD transformation was found in all three RE sesquioxides (RE=Dy, Er, and Lu) regardless of the ion type used in the irradiation. The authors discuss the irradiation-induced OD transformation process in terms of anion disordering, i.e., destruction of the oxygen order associated with the bixbyite structure

  15. 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

  16. 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)

  17. In situ studies of the kinetics of surface topography development during ion irradiation

    International Nuclear Information System (INIS)

    Levinskas, R.; Pranevicius, L.

    1996-01-01

    Studies of the mechanical properties of the materials affected by 25-200 keV H + , He + , Ne + and Ar + ion irradiation in the range of fluences up to 2 · 10 17 cm -2 based on the analysis of acoustic emission signals, kinetics of the surface deformations measured by laser interferometric technique and the variations of the surface acoustic waves propagation velocity are conducted. The acoustic emissions source mechanisms under various ion irradiation conditions are discussed and relative contribution various possible mechanism are indicated. The correlation of experimental results obtained by different methods of analysis is done. (author). 11 refs, 5 figs

  18. Radiation damage and deuterium trapping in deuterium-ion-irradiated Fe–9Cr alloy

    Energy Technology Data Exchange (ETDEWEB)

    Iwakir, Hirotomo, E-mail: iwakiri@edu.u-ryukyu.ac.jp [Faculty and Graduate School of Education, University of the Ryukyus, Nishihara, Okinawa 903-0213 (Japan); Tani, Munechika [Interdisciplinary Graduate School of Engineering Sciences, Kyusyu University, Kasuga, Fukuoka 816-8580 (Japan); Watanabe, Yoshiyuki [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Yoshida, Naoaki [Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    2014-01-15

    Thermal desorption of deuterium (D{sub 2}) from deuterium-ion (D{sub 2}{sup +})-irradiated Fe–9Cr was correlated with the microstructural evolution of the alloy during irradiation with 8-keV D{sub 2}{sup +} ions following annealing to determine the retention and desorption behavior of the implanted deuterium and to identify effective traps for them, particularly at high temperature. After irradiation at 573 K, a new desorption stage formed between 650 and 1100 K at higher fluences, and cavities were observed using transmission electron microscopy. The total amount of trapped deuterium following irradiation with a fluence of 3.0 × 10{sup 22} ions/m{sup 2} was 6.8 × 10{sup 17} D{sub 2}/m{sup 2}, or approximately 0.007%. These results indicate that the deuterium atoms recombined to form D{sub 2} molecules at the surfaces of the cavities.

  19. Damage growth in Si during self-ion irradiation: A study of ion effects over an extended energy range

    International Nuclear Information System (INIS)

    Holland, O.W.; El-Ghor, M.K.; White, C.W.

    1989-01-01

    Damage nucleation/growth in single-crystal Si during ion irradiation is discussed. For MeV ions, the rate of growth as well as the damage morphology are shown to vary widely along the track of the ion. This is attributed to a change in the dominant, defect-related reactions as the ion penetrates the crystal. The nature of these reactions were elucidated by studying the interaction of MeV ions with different types of defects. The defects were introduced into the Si crystal prior to high-energy irradiation by self-ion implantation at a medium energy (100 keV). Varied damage morphologies were produced by implanting different ion fluences. Electron microscopy and ion-channeling measurements, in conjunction with annealing studies, were used to characterize the damage. Subtle changes in the predamage morphology are shown to result in markedly different responses to the high-energy irradiation, ranging from complete annealing of the damage to rapid growth. These divergent responses occur over a narrow range of dose (2--3 times 10 14 cm -2 ) of the medium-energy ions; this range also marks a transition in the growth behavior of the damage during the predamage implantation. A model is proposed which accounts for these observations and provides insight into ion-induced growth of amorphous layers in Si and the role of the amorphous/crystalline interface in this process. 15 refs, 9 figs

  20. Single impacts of keV fullerene ions on free standing graphene: Emission of ions and electrons from confined volume

    Energy Technology Data Exchange (ETDEWEB)

    Verkhoturov, Stanislav V.; Geng, Sheng; Schweikert, Emile A., E-mail: schweikert@chem.tamu.edu [Department of Chemistry, Texas A& M University, College Station, Texas 77843-3144 (United States); Czerwinski, Bartlomiej [Institute of Condensed Matter and Nanosciences–Bio and Soft Matter (IMCN/BSMA), Université Catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium); Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-971 87 Luleå (Sweden); Young, Amanda E. [Materials Characterization Facility, Texas A& M University, College Station, Texas 77843-3122 (United States); Delcorte, Arnaud [Institute of Condensed Matter and Nanosciences–Bio and Soft Matter (IMCN/BSMA), Université Catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium)

    2015-10-28

    We present the first data from individual C{sub 60} impacting one to four layer graphene at 25 and 50 keV. Negative secondary ions and electrons emitted in transmission were recorded separately from each impact. The yields for C{sub n}{sup −} clusters are above 10% for n ≤ 4, they oscillate with electron affinities and decrease exponentially with n. The result can be explained with the aid of MD simulation as a post-collision process where sufficient vibrational energy is accumulated around the rim of the impact hole for sputtering of carbon clusters. The ionization probability can be estimated by comparing experimental yields of C{sub n}{sup −} with those of C{sub n}{sup 0} from MD simulation, where it increases exponentially with n. The ionization probability can be approximated with ejecta from a thermally excited (3700 K) rim damped by cluster fragmentation and electron detachment. The experimental electron probability distributions are Poisson-like. On average, three electrons of thermal energies are emitted per impact. The thermal excitation model invoked for C{sub n}{sup −} emission can also explain the emission of electrons. The interaction of C{sub 60} with graphene is fundamentally different from impacts on 3D targets. A key characteristic is the high degree of ionization of the ejecta.

  1. Surface damage studies of ETFE polymer bombarded with low energy Si ions (≤100 keV)

    International Nuclear Information System (INIS)

    Minamisawa, Renato Amaral; Almeida, Adelaide De; Budak, Satilmis; Abidzina, Volha; Ila, Daryush

    2007-01-01

    Surface studies of ethylenetetrafluoroethylene (ETFE), bombarded with Si in a high-energy tandem Pelletron accelerator, have recently been reported. Si ion bombardment with a few MeV to a few hundred keV energies was shown to be sufficient to produce damage on ETFE film. We report here the use of a low energy implanter with Si ion energies lower than 100 keV, to induce changes on ETFE films. In order to determine the radiation damage, ETFE bombarded films were simulated with SRIM software and analyzed with optical absorption photometry (OAP), Raman and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy to show quantitatively the physical and chemical property changes. Carbonization occurs following higher dose implantation, and hydroperoxides were formed following dehydroflorination of the polymer

  2. Morphological evolution of InP nano-dots and surface modifications after keV irradiation

    International Nuclear Information System (INIS)

    Paramanik, Dipak; Sahu, S N; Varma, Shikha

    2008-01-01

    Evolution and coarsening behaviour of self-assembled nano-dots fabricated on an InP surface by 3 keV Ar ion sputtering have been studied in conjunction with the structural modifications at the surface. The dots have been produced in off-normal geometry but in the absence of rotation. For small sputtering durations, the dots coarsen and agglomerate, up to a critical time t c , while the surface roughens and experiences a tensile stress. A relaxation in this stress is observed after the surface becomes amorphized at t c , beyond which an inverse coarsening, fragmentation of dots and a smoothened surface are observed

  3. 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)

  4. Changes of structural and hydrogen desorption properties of MgH2 indused by ion irradiation

    Directory of Open Access Journals (Sweden)

    Kurko Sandra V.

    2010-01-01

    Full Text Available Changes in structural and hydrogen desorption properties of MgH2 induced by ion irradiation have been investigated. MgH2 powder samples have been irradiated with 45 keV B3+ and 120 keV Ar8+ions, with ion fluence of 1015 ions/cm2. The effects of ion irradiation are estimated by numerical calculations using SRIM package. The induced material modifications and their consequences on hydrogen dynamics in the system are investigated by XRD, particle size distribution and TPD techniques. Changes of TPD spectra with irradiation conditions suggest that there are several mechanisms involved in desorption process which depend on defect concentration and their interaction and ordering. The results confirmed that the near-surface area of MgH2 and formation of a substoichiometric MgHx (x<2 play a crucial role in hydrogen kinetics and that various concentrations of induced defects substantially influence H diffusion and desorption kinetics in MgH2. The results also confirm that there is possibility to control the thermodynamic parameters by controlling vacancies concentration in the system.

  5. INTERBALL-Auroral observations of 0.1-12 keV ion gaps in the diffuse auroral zone

    Directory of Open Access Journals (Sweden)

    R. A. Kovrazhkin

    1999-06-01

    Full Text Available We examine ion flux dropouts detected by INTERBALL-Auroral upon traversal of the auroral zone at altitudes of \\sim13 000 up to 20 000 km. These dropouts which we refer to as "gaps", are frequently observed irrespectively of longitudinal sector and appear characteristic of INTERBALL-Auroral ion spectrograms. Whereas some of these gaps display a nearly monoenergetic character (~12 keV, others occur at energies of a few hundreds of eV up to several keV. INTERBALL-Auroral data exhibit the former monoenergetic gap variety essentially in the evening sector. As examined in previous studies, these gaps appear related to transition from particle orbits that are connected with the magnetotail plasma source to closed orbits encircling the Earth. The latter gap variety, which spreads over several hundreds of eV to a few keV is often observed in the dayside magnetosphere. It is argued that such gaps are due to magnetospheric residence times well above the ion lifetime. This interpretation is supported by numerical orbit calculations which reveal extremely large (up to several tens of hours times of flight in a limited energy range as a result of conflicting E × B and gradient-curvature drifts. The characteristic energies obtained numerically depend upon both longitude and latitude and are quite consistent with those measured in-situ.Key words. Magnetospheric physics (auroral phenomena; plasma convection

  6. 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.))

  7. 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)

  8. 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

  9. Morphological change of self-organized protrusions of fluoropolymer surface by ion beam irradiation

    International Nuclear Information System (INIS)

    Kitamura, Akane; Kobayashi, Tomohiro; Satoh, Takahiro; Koka, Masashi; Kamiya, Tomihiro; Suzuki, Akihiro; Terai, Takayuki

    2013-01-01

    Polytetrafluoroethylene (PTFE) and fluorinated ethylene propylene (FEP) are typical fluoropolymers displaying several desirable technological properties such as electrical insulation and high chemical resistance. When their surfaces are irradiated with ion beams, dense micro-protrusions formed after the emergence and spread of micropores across the entire irradiated area, allowing culture cells to spread on the top of the protrusions. In this study, we investigate the morphological changes introduced in the fluoropolymer surfaces by ion beams as the energy of the beams is increased. When an FEP sample was irradiated with a nitrogen ion beam with an energy of less than 350 keV at 1.0 μA/cm 2 , protrusions were formed with a density between 2 × 10 7 /cm 2 and 2 × 10 8 /cm 2 . However, at energies higher than 350 keV, the protrusions became sparse, and the density dropped to 5 × 10 2 /cm 2 . Protrusions appeared sporadically during irradiation at high energies, and the top of the protrusions appeared as spots inside the sample, which were difficult to etch and became elongated as the erosion of the surface progressed. Erosion was caused by sputtering of FEP molecules and evaporation at notably elevated temperatures on the surface. Analysis based on attenuated total reflectance/Fourier transform infrared spectroscopy showed the presence of C=C bonds as well as –COOH, –C=O, and –OH bonds on all irradiated samples. Their concentration on the surface densely covered with micro-protrusions was higher than that on the surface with sparse protrusions after irradiation at energies exceeding 350 keV. Thus, we determined a suitable range for the ion energy for creating FEP surfaces densely covered with protrusions

  10. Synthesizing single-phase β-FeSi2 via ion beam irradiations of Fe/Si bilayers

    International Nuclear Information System (INIS)

    Milosavljevic, M.; Dhar, S.; Schaaf, P.; Bibic, N.; Lieb, K.P.

    2001-01-01

    This paper presents results on the direct synthesis of the β-FeSi 2 phase by ion beam mixing of Fe/Si bilayers with Xe ions. The influence of the substrate temperature, ion fluence and energy on the growth of this phase was investigated using Rutherford backscattering (RBS), X-ray diffraction (XRD) and conversion electron Moessbauer spectroscopy (CEMS). Complete growth of single-phase β-FeSi 2 was achieved by 205 keV Xe ion irradiation to a fluence of 2x10 16 ions/cm 2 at 600 deg. C. We propose a two-step reaction mechanism involving thermal and ion beam energy deposition

  11. Crystal orientation and sample preparation effects on sputtering and lattice damage in 100 keV self-irradiated copper

    International Nuclear Information System (INIS)

    Sprague, J.A.; Malmberg, P.R.; Reynolds, G.W.; Lambert, J.M.; Treado, P.A.; Vincenz, A.M.

    1987-01-01

    Sputtering yields and angular distributions have been measured as functions of sample preparation techniques and incident ion-beam orientation with respect to the crystal axes for 100 keV Cu-ion beams on Cu crystals and polycrystalline samples. The angular distributions have structure requiring an nth order cosine with two Gaussians superimposed to fit the data; strong peaking is observed near the backscatter direction. The yield is dependent on the beam to crystal and beam to polycrystalline-rod axis orientation, on the grain size of the polycrystals and on sample-preparation techniques. Yield measurements vary by as much as a factor of 4. Lattice-damage differences, measured with alpha particle channeling, are much smaller and seem to be saturated by fluences of the order of 1x10 16 /cm 2 . (orig.)

  12. Ion irradiation-induced diffusion in bixbyite-fluorite related oxides: Dislocations and phase transformation

    Energy Technology Data Exchange (ETDEWEB)

    Rolly, Gaboriaud, E-mail: Rolly.gaboriaud@univ-poitiers.fr [Institut Pprime, CNRS-University of Poitiers, SP2MI-BP 30179, 86962 Chasseneuil-Futuroscope (France); Fabien, Paumier [Institut Pprime, CNRS-University of Poitiers, SP2MI-BP 30179, 86962 Chasseneuil-Futuroscope (France); Bertrand, Lacroix [CSIC – University of Sevilla, Avenida Américo Vespucio, 49, 41092 Sevilla (Spain)

    2014-05-01

    Ion-irradiation induced diffusion and the phase transformation of a bixbyite-fluorite related rare earth oxide thin films are studied. This work is focused on yttrium sesquioxide, Y{sub 2}O{sub 3}, thin films deposited on Si (1 0 0) substrates using the ion beam sputtering technique (IBS). As-deposited samples were annealed ant then irradiated at cryogenic temperature (80 K) with 260 keV Xe{sup 2+} at different fluences. The irradiated thin oxide films are characterized by X-ray diffraction. A cubic to monoclinic phase transformation was observed. Analysis of this phenomenon is done in terms of residual stresses. Stress measurements as a function of irradiation fluences were realised using the XRD-sin{sup 2}ψ method. Stress evolution and kinetic of the phase transformation are compared and leads to the role-played by the nucleation of point and extended defects.

  13. Molecular nature of mutations induced by high-LET irradiation with argon and carbon ions in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Hirano, Tomonari; Kazama, Yusuke; Ohbu, Sumie; Shirakawa, Yuki; Liu Yang; Kambara, Tadashi; Fukunishi, Nobuhisa; Abe, Tomoko

    2012-01-01

    Linear energy transfer (LET) is an important parameter to be considered in heavy-ion mutagenesis. However, in plants, no quantitative data are available on the molecular nature of the mutations induced with high-LET radiation above 101–124 keV μm −1 . In this study, we irradiated dry seeds of Arabidopsis thaliana with Ar and C ions with an LET of 290 keV μm −1 . We analyzed the DNA alterations caused by the higher-LET radiation. Mutants were identified from the M 2 pools. In total, 14 and 13 mutated genes, including bin2, egy1, gl1, gl2, hy1, hy3–5, ttg1, and var2, were identified in the plants derived from Ar- and C-ions irradiation, respectively. In the mutants from both irradiations, deletion was the most frequent type of mutation; 13 of the 14 mutated genes from the Ar ion-irradiated plants and 11 of the 13 mutated genes from the C ion-irradiated plants harbored deletions. Analysis of junction regions generated by the 2 types of irradiation suggested that alternative non-homologous end-joining was the predominant pathway of repair of break points. Among the deletions, the proportion of large deletions (>100 bp) was about 54% for Ar-ion irradiation and about 64% for C-ion irradiation. Both current results and previously reported data revealed that the proportions of the large deletions induced by 290-keV μm −1 radiations were higher than those of the large deletions induced by lower-LET radiations (6% for 22.5–30.0 keV μm −1 and 27% for 101–124 keV μm −1 ). Therefore, the 290 keV μm −1 heavy-ion beams can effectively induce large deletions and will prove useful as novel mutagens for plant breeding and analysis of gene functions, particularly tandemly arrayed genes.

  14. Molecular nature of mutations induced by high-LET irradiation with argon and carbon ions in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Tomonari; Kazama, Yusuke [Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Innovation Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Ohbu, Sumie; Shirakawa, Yuki; Liu Yang; Kambara, Tadashi; Fukunishi, Nobuhisa [Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Abe, Tomoko, E-mail: tomoabe@riken.jp [Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Innovation Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2012-07-01

    Linear energy transfer (LET) is an important parameter to be considered in heavy-ion mutagenesis. However, in plants, no quantitative data are available on the molecular nature of the mutations induced with high-LET radiation above 101-124 keV {mu}m{sup -1}. In this study, we irradiated dry seeds of Arabidopsis thaliana with Ar and C ions with an LET of 290 keV {mu}m{sup -1}. We analyzed the DNA alterations caused by the higher-LET radiation. Mutants were identified from the M{sub 2} pools. In total, 14 and 13 mutated genes, including bin2, egy1, gl1, gl2, hy1, hy3-5, ttg1, and var2, were identified in the plants derived from Ar- and C-ions irradiation, respectively. In the mutants from both irradiations, deletion was the most frequent type of mutation; 13 of the 14 mutated genes from the Ar ion-irradiated plants and 11 of the 13 mutated genes from the C ion-irradiated plants harbored deletions. Analysis of junction regions generated by the 2 types of irradiation suggested that alternative non-homologous end-joining was the predominant pathway of repair of break points. Among the deletions, the proportion of large deletions (>100 bp) was about 54% for Ar-ion irradiation and about 64% for C-ion irradiation. Both current results and previously reported data revealed that the proportions of the large deletions induced by 290-keV {mu}m{sup -1} radiations were higher than those of the large deletions induced by lower-LET radiations (6% for 22.5-30.0 keV {mu}m{sup -1} and 27% for 101-124 keV {mu}m{sup -1}). Therefore, the 290 keV {mu}m{sup -1} heavy-ion beams can effectively induce large deletions and will prove useful as novel mutagens for plant breeding and analysis of gene functions, particularly tandemly arrayed genes.

  15. A New Understanding of Near-Threshold Damage for 200 keV Irradiation In Silicon

    International Nuclear Information System (INIS)

    Stoddard, Nathan; Duscher, Gerd J.M.; Windl, Wolfgang; Rozgonyi, G.A.

    2005-01-01

    Recently we reported room temperature point defect creation and subsequent extended defect nucleation in nitrogen-doped silicon during 200 kV electron irradiation, while identical irradiation of nitrogen-free silicon produced no effect. In this paper, first principles calculations are combined with new transmission electron microscope (TEM) observations to support a new model for elastic electron-silicon interactions in the TEM, which encompasses both nitrogen doped and nitrogen free silicon. Specifically, the nudged elastic band method was used to study the energetics along the diffusion path during an electron collision event in the vicinity of a nitrogen pair. It was found that the 0 K estimate for the energy barrier of a knock-on event is lowered from ∼12 to 6.2 eV. However, this is still inadequate to explain the observations. We therefore propose an increase in the energy barrier for Frenkel pair recombination associated with N 2 -V bonding. Concerning pure silicon, stacking fault formation near irradiation-induced holes demonstrates the participation of bulk processes. In low oxygen float zone material, 2--5 nm voids were formed, while oxygen precipitation in Czochralski Si has been verified by electron energy-loss spectroscopy. Models of irradiation-induced point defect aggregation are presented and it is concluded that these must be bulk and not surface mediated phenomena.

  16. Synthesis of sponge-like hydrophobic NiBi_3 surface by 200 keV Ar ion implantation

    International Nuclear Information System (INIS)

    Siva, Vantari; Datta, D.P.; Chatterjee, S.; Varma, S.; Kanjilal, D.; Sahoo, Pratap K.

    2017-01-01

    Highlights: • A sponge-like hydrophobic NiBi_3 surface has been synthesized using 200 keV Ar ion implantation. • A competition between amorphization and re-crystallization was observed in the existing phases owing to comparable magnitudes of nuclear and electronic energy depositions. • The relation between hydrophobic nature and sponge-like NiBi_3 phase seems interesting, which is attributed to ion beam induced sputtering and mixing of the layers. - Abstract: Sponge-like nanostructures develop under Ar-ion implantation of a Ni–Bi bilayer with increasing ion fluence at room temperature. The surface morphology features different stages of evolution as a function of ion fluence, finally resulting in a planar surface at the highest fluence. Our investigations on the chemical composition reveal a spontaneous formation of NiBi_3 phase on the surface of the as deposited bilayer film. Interestingly, we observe a competition between crystallization and amorphization of the existing poly-crystalline phases as a function of the implanted fluence. Measurements of contact angle by sessile drop method clearly show the ion-fluence dependent hydrophobic nature of the nano-structured surfaces. The wettability has been correlated with the variation in roughness and composition of the implanted surface. In fact, our experimental results confirm dominant effect of ion-sputtering as well as ion-induced mixing at the bilayer interface in the evolution of the sponge-like surface.

  17. Synthesis of sponge-like hydrophobic NiBi{sub 3} surface by 200 keV Ar ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Siva, Vantari; Datta, D.P. [School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni 752050 (India); Chatterjee, S. [Colloids and Materials Chemistry Department, CSIR-Institute of Minerals and Materials Technology, Acharya Vihar, Bhubaneswar 751 013 (India); Varma, S. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Sahoo, Pratap K., E-mail: pratap.sahoo@niser.ac.in [School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni 752050 (India)

    2017-07-15

    Highlights: • A sponge-like hydrophobic NiBi{sub 3} surface has been synthesized using 200 keV Ar ion implantation. • A competition between amorphization and re-crystallization was observed in the existing phases owing to comparable magnitudes of nuclear and electronic energy depositions. • The relation between hydrophobic nature and sponge-like NiBi{sub 3} phase seems interesting, which is attributed to ion beam induced sputtering and mixing of the layers. - Abstract: Sponge-like nanostructures develop under Ar-ion implantation of a Ni–Bi bilayer with increasing ion fluence at room temperature. The surface morphology features different stages of evolution as a function of ion fluence, finally resulting in a planar surface at the highest fluence. Our investigations on the chemical composition reveal a spontaneous formation of NiBi{sub 3} phase on the surface of the as deposited bilayer film. Interestingly, we observe a competition between crystallization and amorphization of the existing poly-crystalline phases as a function of the implanted fluence. Measurements of contact angle by sessile drop method clearly show the ion-fluence dependent hydrophobic nature of the nano-structured surfaces. The wettability has been correlated with the variation in roughness and composition of the implanted surface. In fact, our experimental results confirm dominant effect of ion-sputtering as well as ion-induced mixing at the bilayer interface in the evolution of the sponge-like surface.

  18. Energetic Ion and Electron Irradiation of the Icy Galilean Satellites

    Science.gov (United States)

    Cooper, John F.; Johnson, Robert E.; Mauk, Barry H.; Garrett, Henry B.; Gehrels, Neil

    2001-01-01

    Galileo Orbiter measurements of energetic ions (20 keV to 100 MeV) and electrons (20-700 keV) in Jupiter's magnetosphere are used, in conjunction with the JPL electron model (less than 40 MeV), to compute irradiation effects in the surface layers of Europa, Ganymede, and Callisto. Significant elemental modifications are produced on unshielded surfaces to approximately centimeter depths in times of less than or equal to 10(exp 6) years, whereas micrometer depths on Europa are fully processed in approximately 10 years. Most observations of surface composition are limited to optical depths of approximately 1 mm, which are indirect contact with the space environment. Incident flux modeling includes Stormer deflection by the Ganymede dipole magnetic field, likely variable over that satellite's irradiation history. Delivered energy flux of approximately 8 x 10(exp 10) keV/square cm-s at Europa is comparable to total internal heat flux in the same units from tidal and radiogenic sources, while exceeding that for solar UV energies (greater than 6 eV) relevant to ice chemistry. Particle energy fluxes to Ganymede's equator and Callisto are similar at approximately 2-3 x 10(exp 8) keV/square cm-s with 5 x 10(exp 9) at Ganymede's polar cap, the latter being comparable to radiogenic energy input. Rates of change in optical reflectance and molecular composition on Europa, and on Ganymede's polar cap, are strongly driven by energy from irradiation, even in relatively young regions. Irradiation of nonice materials can produce SO2 and CO2, detected on Callisto and Europa, and simple to complex hydrocarbons. Iogenic neutral atoms and meteoroids deliver negligible energy approximately 10(exp 4-5) keV/square cm-s but impacts of the latter are important for burial or removal of irradiation products. Downward transport of radiation produced oxidants and hydrocarbons could deliver significant chemical energy into the satellite interiors for astrobiological evolution in putative sub

  19. Electrophoresis examination of strand breaks in plasmid DNA induced by low-energy nitrogen ion irradiation

    International Nuclear Information System (INIS)

    Zhao Yong; Tan Zheng; Du Yanhua; Qiu Guanying

    2003-01-01

    To study the effect on plasmid DNA of heavy ion in the energy range of keV where nuclear stopping interaction becomes more important or even predominant, thin film of plasmid pGEM-3Zf(-) DNA was prepared on aluminum surface and irradiated in vacuum ( -3 Pa) by low-energy nitrogen ions with energy of 30 keV (LET=285 keV/μm) at various fluence ranging from 2 x 10 10 to 8.2 x 10 13 ions/cm 2 . DNA strand breaks were analyzed by neutral electrophoresis followed by quantification with image analysis software. Low-energy nitrogen ion irradiation induced single-, double- and multiple double-strand breaks (DSB) and multiple DSB as the dominating form of DNA damages. Moreover, the linear fluence-response relationship at a low fluence range suggests that DSBs are induced predominantly by single ion track. However, strand break production is limited to a short range in the irradiated samples

  20. 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

  1. Shape manipulation of ion irradiated Ag nanoparticles embedded in lithium niobate

    International Nuclear Information System (INIS)

    Wolf, Steffen; Rensberg, Jura; Johannes, Andreas; Ronning, Carsten; Thomae, Rainer; Smit, Frederick; Neveling, Retief; Bharuth-Ram, Krish; Moodley, Mathew; Bierschenk, Thomas; Rodriguez, Matias; Afra, Boshra; Ridgway, Mark; Hasan, Shakeeb Bin; Rockstuhl, Carsten

    2016-01-01

    Spherical silver nanoparticles were prepared by means of ion beam synthesis in lithium niobate. The embedded nanoparticles were then irradiated with energetic "8"4Kr and "1"9"7Au ions, resulting in different electronic energy losses between 8.1 and 27.5 keV nm"−"1 in the top layer of the samples. Due to the high electronic energy losses of the irradiating ions, molten ion tracks are formed inside the lithium niobate in which the elongated Ag nanoparticles are formed. This process is strongly dependent on the initial particle size and leads to a broad aspect ratio distribution. Extinction spectra of the samples feature the extinction maximum with shoulders on either side. While the maximum is caused by numerous remaining spherical nanoparticles, the shoulders can be attributed to elongated particles. The latter could be verified by COMSOL simulations. The extinction spectra are thus a superposition of the spectra of all individual particles. (paper)

  2. 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.

  3. Improvement of voltage holding capability in the 500 keV negative ion source for JT-60SA.

    Science.gov (United States)

    Tanaka, Y; Hanada, M; Kojima, A; Akino, N; Shimizu, T; Ohshima, K; Inoue, T; Watanabe, K; Taniguchi, M; Kashiwagi, M; Umeda, N; Tobari, H; Grisham, L R

    2010-02-01

    Voltage holding capability of JT-60 negative ion source that has a large electrostatic negative ion accelerator with 45 cm x 1.1 m acceleration grids was experimentally examined and improved to realize 500 keV, 22 A, and 100 s D- ion beams for JT-60 Super Advanced. The gap lengths in the acceleration stages were extended to reduce electric fields in a gap between the large grids and at the corner of the support flanges from the original 4-5 to 3-4 kV/mm. As a result, the voltage holding capability without beam acceleration has been successfully improved from 400 to 500 kV. The pulse duration to hold 500 kV reached 40 s of the power supply limitation.

  4. Surface wet-ability modification of thin PECVD silicon nitride layers by 40 keV argon ion treatments

    Science.gov (United States)

    Caridi, F.; Picciotto, A.; Vanzetti, L.; Iacob, E.; Scolaro, C.

    2015-10-01

    Measurements of wet-ability of liquid drops have been performed on a 30 nm silicon nitride (Si3N4) film deposited by a PECVD reactor on a silicon wafer and implanted by 40 keV argon ions at different doses. Surface treatments by using Ar ion beams have been employed to modify the wet-ability. The chemical composition of the first Si3N4 monolayer was investigated by means of X-ray Photoelectron Spectroscopy (XPS). The surface morphology was tested by Atomic Force Microscopy (AFM). Results put in evidence the best implantation conditions for silicon nitride to increase or to reduce the wet-ability of the biological liquid. This permits to improve the biocompatibility and functionality of Si3N4. In particular experimental results show that argon ion bombardment increases the contact angle, enhances the oxygen content and increases the surface roughness.

  5. 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.

  6. 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.

  7. Irradiation characteristics of metal-cluster-complex ions containing diverse multi-elements with large mass differences

    International Nuclear Information System (INIS)

    Fujiwara, Yukio; Kondou, Kouji; Teranishi, Yoshikazu; Nonaka, Hidehiko; Saito, Naoaki; Fujimoto, Toshiyuki; Kurokawa, Akira; Ichimura, Shingo; Tomita, Mitsuhiro

    2007-01-01

    Tetrairidium dodecacarbonyl, Ir 4 (CO) 12 , is a metal cluster complex which has a molecular weight of 1104.9. Using a metal-cluster-complex ion source, the interaction between Ir 4 (CO) n + ions (n=0-12) and silicon substrates was studied at a beam energy ranging from 2keV to 10keV at normal incidence. By adjusting Wien-filter voltage, the influence of CO ligands was investigated. Experimental results showed that sputtering yield of silicon bombarded with Ir 4 (CO) n + ions at 10keV decreased with the number of CO ligands. In the case of 2keV, deposition tended to be suppressed by removing CO ligands from the impinging cluster ions. The influence of CO ligands was explained by considering changes in surface properties caused by the irradiation of Ir 4 (CO) n + ions. It was also found that the bombardment with Ir 4 (CO) 7 + ions at 2.5keV caused deposition on silicon target

  8. Charge changing and excitation cross sections for 1-25 KeV hydrogen ions and atoms incident on sodium

    International Nuclear Information System (INIS)

    Howald, A.M.

    1983-01-01

    Measurements of charge changing and excitation cross sections for 1-25 keV beams of hydrogen atoms and ions incident on a sodium vapor target are reported. The charge changing cross sections are for reactions in which the incident H ion or atom gains or loses an electron during a collision with a Na atoms to form a hydrogen ion or atom in a different charge state. The six cross sections measured are sigma/sub +0/ and sigma/sub +-/ for incident protons, sigma/sub -0/ and sigma/sub -+/ for incident H - ions, and sigma/sub g-/ and sigma/sub g+/ for incident H(1s) atoms. Measurements are also reported for the negative, neutral, and positve equilibrium fractions for H beams in thick Na targets. The excitation cross sections are for reactions in which the Na target atom is excited to the 3p level by a collision with a H atom or ion. The five cross sections measured are for incident H + , H 2 + , H 3 + , and H - ions, and for H(1s) atoms. These cross sections are measured using a new technique that compares them directly to the known cross section for excitation by electron impact

  9. Effects of 500 keV electron irradiation and subsequent annealing on 1/f noise in copper films

    International Nuclear Information System (INIS)

    Pelz, J.; Clarke, J.

    1985-10-01

    Polycrystalline copper films were maintained at 90K on the cold stage of an electron microscope and irradiated with 500keV electrons to induce defect. With an electron dose of about 5 x 10 20 cm -2 , the spectral density of the noise voltage across the films increased by an order of magnitude while the electrical resistivity increased by at most 10%. The films were annealed at progressively higher temperatures; after each annealing process the 1/f noise and resistivity were remeasured at 90K. Both the 1/f noise and resistivity were reduced, but at the lower annealing temperatures the fractional reduction in the added noise was substantially more than in the added resistivity. These result suggest that a large fraction of the added noise may be generated by a small mobile fraction of the added defects that are more readily annealed than the majority of the defects. After a room temperature annealing process, both the noise and resistivity returned nearly to their initial values. The temperature dependence of the noise after irradiation and partial annealing was consistant with the Dutta-Dimon-Horn thermal activation model

  10. The effects of 500 keV electron irradiation and subsequent annealing on 1/f noise in copper films

    International Nuclear Information System (INIS)

    Pelz, J.; Clarke, J.

    1986-01-01

    Polycrystalline copper films were maintained at 90K on the cold stage of an electron microscope and irradiated with 500keV electrons to induce defects. With an electron dose of about 5 x 10 20 cm -2 , the spectral density of the noise voltage across the films increased by an order of magnitude while the electrical resistivity increased by at most 10%. The films were annealed at progressively higher temperatures; after each annealing process the 1/f noise and resistivity were remeasured at 90K. Both the 1/f noise and resistivity were reduced, but at the lower annealing temperatures the fractional reduction in the added noise was substantially more than in the added resistivity. These results suggest that a large fraction of the added noise may be generated by a small mobile fraction of the added defects that are more readily annealed than the majority of the defects. After a room temperature annealing process, both the noise and resistivity returned nearly to their initial values. The temperature dependence of the noise after irradiation and partial annealing was consistent with the Dutta-Dimon-Horn thermal activation model. (Auth.)

  11. Surface structure of Cr0.5 Ti0.5N coatings after heavy ions irradiation and annealing

    International Nuclear Information System (INIS)

    Kislitsin, Sergey; Gorlachev, Igor; Uglov, Vladimir

    2015-01-01

    Results of surface structure investigations of TiCrN coating on carbon steel after irradiation by helium, krypton and xenon heavy ions are reported in the present publication. The series of Cr50Ti50N coatings on carbon steel with thickness of 50,..., 300 nm were formed by vacuum arc deposition techniques. Specimens with TiCrN coating on carbon steel were irradiated by low energy 4 He +1 (22 keV) and 4 He +2 (40 keV) ions and high energy Xe +18 and Kr +14 ions with energy of 1.5 MeV/nucleon. Fluence of He ions was 1.0x10 17 ion.cm -2 , fluence of Xe and Kr ions was 5x10 14 -1.0x10 15 ion.cm -2 , irradiation temperature did not exceed 150 deg. C. Study of surface structure was performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Methods of Roentgen diffractometry and Rutherford backscattering was applied for determination of structure and thickness of coating. In case of irradiation with Xe +18 and Kr +14 ions an investigation of surface morphology and structure was done after successive two hours vacuum annealing of irradiated samples at temperatures 400 deg. C, 500 deg. C and 600 deg. C. It was shown that after irradiation by Xe and Kr ions on the surface of coating convexities appear, surface density of which correlates with ion flux. In the case of Xe, ions irradiation generated convexities of spherical and elongated shape with dimensions ranging from ten to hundreds nm. In the case of Kr ions, only spherical globules were generated, dimensions of which are 10-30 nm. The most likely explanation of observed surface damage is that: convexities on the surface are generated at ion bombardment of specimens with coating. Convexities are the traces of ions passing through coating and they are due to structural reconstruction at energy release along a trajectory of ions braking. Convexities of elongated shape represent overlapping traces from two passing ions. When the projective range of Xe and Kr ions exceeds coating thickness, damage

  12. 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

  13. 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)

  14. 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

  15. Study on mutation breeding and fermentation of antimicrobial lipopeptides yielding bacterium with 20 keV N+ ion beam implantation

    International Nuclear Information System (INIS)

    Fang Chuanji; Lu Zhaoxin; Sun Lijun; Lv Fengxia; Bie Xiaomei

    2006-01-01

    Bacillus amyloliquefaciens ES-2 was implanted with 20 keV N + ion beam to breed mutants of high yield of antimicrobial lipopeptides. The dose effects of the nitrogen ion implantation on the survival and positive mutations rate was studied. The mutant strain designated as B. amyloliquefaciens ES-2-4 showing higher yield of antimicrobial lipopeptides was obtained. The concentration of the lipopeptides in fermentation liquid increased by 15.2% compared with the original strain. The authors also studied the fermentation process between the mutant and the original strain. It indicated that the mutant with shorter lag phase, longer stable phase and higher yield of the lipopeptides, which was suitable for large-scale production. (authors)

  16. Long-term stable transmission of 3-keV Ne7+ ions guided through nanocapillaries in polymers

    International Nuclear Information System (INIS)

    Stolterfoht, N.; Herczku, P.; Juhász, Z.; Kovács, S.T.S.; Rácz, R.; Biri, S.; Sulik, B.

    2016-01-01

    We studied blocking effects on 3-keV Ne 7+ ion guiding through nanocapillaries in highly insulating polyethylene terephthalate (PET) manufactured at different laboratories. The experiments were motivated in view of previous measurement with PET capillaries prepared at the GSI Helmholtz-Zentrum for which significant blocking effects were observed, whereas in various previous studies with PET capillaries these effects could not be detected. As the blocking effect on the GSI capillaries strongly depends on their areal density, similar dependencies were studied with the FLNR capillaries. Long-term stable transmission was observed for all densities of the FLNR capillaries in contrast to the previous results. These observations are interpreted by differences in the capillary surface conductivities in accordance with charge patch formations within the capillaries. It is pointed out that the observed stable transmission is favorable for applications of ion guiding in capillaries.

  17. Long-term stable transmission of 3-keV Ne{sup 7+} ions guided through nanocapillaries in polymers

    Energy Technology Data Exchange (ETDEWEB)

    Stolterfoht, N., E-mail: nico@stolterfoht.com [Helmholtz-Zentrum Berlin fnr Materialien und Energie, 14109 Berlin (Germany); Herczku, P.; Juhász, Z.; Kovács, S.T.S.; Rácz, R.; Biri, S.; Sulik, B. [Institute of Nuclear Research (ATOMKI), 4001 Debrecen (Hungary)

    2016-11-15

    We studied blocking effects on 3-keV Ne{sup 7+} ion guiding through nanocapillaries in highly insulating polyethylene terephthalate (PET) manufactured at different laboratories. The experiments were motivated in view of previous measurement with PET capillaries prepared at the GSI Helmholtz-Zentrum for which significant blocking effects were observed, whereas in various previous studies with PET capillaries these effects could not be detected. As the blocking effect on the GSI capillaries strongly depends on their areal density, similar dependencies were studied with the FLNR capillaries. Long-term stable transmission was observed for all densities of the FLNR capillaries in contrast to the previous results. These observations are interpreted by differences in the capillary surface conductivities in accordance with charge patch formations within the capillaries. It is pointed out that the observed stable transmission is favorable for applications of ion guiding in capillaries.

  18. à la capture de radicaux sous irradiation X à 1,5 keV

    Directory of Open Access Journals (Sweden)

    Khalil Talat Tariq

    2016-01-01

    Full Text Available L’environnement chimique de l’ADN en situation biologique est complexe notam-ment en raison de la présence d’histones, protéines nucléaires, associées en quantité approximativement égales à l’ADN pour former la chromatine. Les histones possèdent de nombreux radicaux basiques arginine et lysine chargés positivement et dont la majorité se trouve sur les chaînes émergentes, l’ADN présente quant à lui des charges négatives sur ses groupements phosphates localisés tout au long de la double hélice. Dans cette étude, la complexité de la structure de la chromatine nucléaire est dans un premier temps mimée en solution aqueuse par la formation de complexes entre un ADN plasmidique sonde et les trois acides aminés basiques, Arg, His, Lys, qui, mis à part His, sont protonés au pH physiologique. Ces acides aminés libres en solution sont réputés être des capteurs efficaces de radicaux libres, notamment pour le radical hydroxyle, conférant ainsi un pouvoir protecteur vis-à-vis des effets indirects sur l’ADN en situation d’exposition aux rayonnements ionisants. A concentration fixée, les capacités de capture des acides aminés libres, σ, pour le radical hydroxyle sont typiquement les suivantes σHis ≈σArg > σLys (σLys ≈ 0,1 × σArg. Nous avons mesuré les taux de cassures simple brin par plasmide et par Gray (χ lors d’expositions de solutions aqueuses de complexes [acide aminé – ADN plasmidique] aux rayons X ultra-mous (1,5 keV. A concentrations égales, les trois acides aminés complexés et présents en large excès ne manifestent pas une capacité de protection de l’ADN proportionnelle à leur capacité de capture libre et en solution ; on trouve en effet des taux de cassures dans l’ordre suivant χHis > χArg > χLys (χLys ≈ 0,01 χArg. Après avoir détaillé le mode opératoire de ces mesures, nous analyserons sur des bases bibliographiques, les modes spécifiques d’interaction des

  19. Anomalously high yield of doubly charged Si ions sputtered from cleaned Si surface by keV neutral Ar impact

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.; Morita, K. E-mail: k-morita@mail.nucl.nagoya-u.ac.jp; Dhole, S.D.; Ishikawa, D

    2001-08-01

    The energy spectra of positively charged and neutral species ejected from the Si(1 1 1) surfaces by keV Ar impact have been measured by means of a combined technique of the time-of-flight (TOF) analysis with the multi-photon resonance ionization spectroscopy (MPRIS). It is shown that positively charged species of Si{sup +}, Si{sup 2+} and SiO{sup +} are ejected from the as-cleaned 7x7 surface by 11 keV Ar impact. It is also shown that Ar sputter cleaning of the as-cleaned 7x7 surface for 14 min at the flux of 2x10{sup 13}/cm{sup 2}s removes completely the oxygen impurity and the yields of Si{sup 2+} is comparable to that of Si{sup +}. Moreover, the ionization probability of Si atoms sputtered is shown to be expressed as an exponential function of the inverse of their velocity. The production mechanism for the doubly charged Si ion is discussed based on the L-shell ionization of Si atoms due to quasi-molecule formation in the collisions of the surface atoms with energetic recoils and subsequent Auger decay of the L-shell vacancy to doubly ionized Si ions.

  20. Reduction of transient diffusion from 1 endash 5 keV Si+ ion implantation due to surface annihilation of interstitials

    International Nuclear Information System (INIS)

    Agarwal, A.; Gossmann, H.-.; Eaglesham, D.J.; Pelaz, L.; Jacobson, D.C.; Haynes, T.E.; Erokhin, Y.E.

    1997-01-01

    The reduction of transient enhanced diffusion (TED) with reduced implantation energy has been investigated and quantified. A fixed dose of 1x10 14 cm -2 Si + was implanted at energies ranging from 0.5 to 20 keV into boron doping superlattices and enhanced diffusion of the buried boron marker layers was measured for anneals at 810, 950, and 1050 degree C. A linearly decreasing dependence of diffusivity enhancement on decreasing Si + ion range is observed at all temperatures, extrapolating to ∼1 for 0 keV. This is consistent with our expectation that at zero implantation energy there would be no excess interstitials from the implantation and hence no TED. Monte Carlo modeling and continuum simulations are used to fit the experimental data. The results are consistent with a surface recombination length for interstitials of <10 nm. The data presented here demonstrate that in the range of annealing temperatures of interest for p-n junction formation, TED is reduced at smaller ion implantation energies and that this is due to increased interstitial annihilation at the surface. copyright 1997 American Institute of Physics

  1. Ripple structures on surfaces and underlying crystalline layers in ion beam irradiated Si wafers

    Energy Technology Data Exchange (ETDEWEB)

    Grenzer, J.; Muecklich, A. [Forschungszentrum Rossendorf, Institut fuer Ionenstrahlphysik und Materialforschung, Dresden (Germany); Biermanns, A.; Grigorian, S.A.; Pietsch, U. [Institute of Physics, University of Siegen (Germany)

    2009-08-15

    We report on the formation of ion beam induced ripples in Si(001) wafers when bombarded with Ar+ ions at an energy of 60 keV. A set of samples varying incidence and azimuthal angles of the ion beam with respect to the crystalline surface orientation was studied by two complementary near surface sensitive techniques, namely atomic force microscopy and depth-resolved X-ray grazing incidence diffraction (GID). Additionally, cross-section TEM investigations were carried out. The ripple-like structures are formed at the sample surface as well as at the buried amorphous-crystalline interface. Best quality of the ripple pattern was found when the irradiating ion beam was aligned parallel to the (111) planes. The quality decreases rapidly if the direction of the ion beam deviates from (111). (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  2. 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

  3. Storing keV negative ions for hours: Lifetime measurements in new time domains

    International Nuclear Information System (INIS)

    Kaminska, M; Bäckström, E; Hole, O M; Nascimento, R F; Blom, M; Björkhage, M; Källberg, A; Löfgren, P; Reinhed, P; Rosèn, S; Thomas, R D; Mannervik, S; Schmidt, H T; Cederquist, H; Hanstorpt, D

    2015-01-01

    We have used one of the cryogenic ion storage rings of DESIREE to measure the lifetime of the 2 P° 1/2 level in the sulfur anion to be 503 ± 43 seconds. This is orders of magnitude longer than any previously measured lifetime in a negatively charged ion. (paper)

  4. 3–10 keV Xe+ ion beam machining of ultra low thermal expansion glasses for EUVL projection optics: Evaluation of surface roughness

    International Nuclear Information System (INIS)

    Morikawa, K.; Kamijo, K.; Morijiri, K.; Pahlovy, S.A.; Aikawa, N.; Miyamoto, I.

    2012-01-01

    In order to obtain surface figure error of 0.15 nm rms and surface roughness (R rms ) of 0.12 nm rms for aspherical substrates in EUVL tools, ion beam figuring may be adopted to final surface figure error correction of aspherical substrates. During figure error correction, machined surface of the substrate becomes rougher than the pre-finished one. Therefore, we investigated the machined depth and ion energy dependences of R rms (measured by an AFM) of substrates machined by 3–10 keV Xe + ion beam, and compared them with the results obtained for Ar + ion beam. Result shows that the R rms s of CLEARCERAM®-Z, Zerodur® and ULE® substrates machined to the depth of 50 nm by 3–10 keV Xe + ion beam at the normal ion incidence angle become approximately 0.25, 0.28 and 0.15 nm rms, respectively. Those values are larger than the pre-finished substrates (0.07–0.09 nm rms), but smaller than that (0.60 nm rms for CLEARCERAM®-Z, 0.61 nm rms for Zerodur® and 0.18 nm rms for ULE®) of the substrates machined by Ar + ion beam. Moreover, the R rms s merely increase with increasing ion energy. The R rms s of the ULE® substrate machined by 3–10 keV Xe + ion beam rapidly increase with increasing machined depth, then saturate at machined depth of 10–50 nm. The saturated values of the R rms s are 0.12 and 0.15 nm rms for 3 and 10 keV Xe + ion beam respectively. We suggest that the 3 keV Xe + ion beam machining can be applicable for final shape correction of ULE® substrates for EUVL projection optics in association with considering further ultra smoothing process such as Si deposition or low energy ion beam smoothing.

  5. Changes in mass loss and chemistry of AG-80 epoxy resin after 160 keV proton irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yu [Space Materials and Environment Engineering Lab, Harbin Institute of Technology, Harbin, 150001 (China)]. E-mail: czq04@yahoo.com.cn; Sun Mingren [College of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001 (China); Yang Dezhuang [Space Materials and Environment Engineering Lab, Harbin Institute of Technology, Harbin, 150001 (China); He Shiyu [Space Materials and Environment Engineering Lab, Harbin Institute of Technology, Harbin, 150001 (China); Wang Jinhe [Precision Engineering Research Institute, Harbin Institute of Technology, Harbin, 150001 (China); Xiao Jingdong [Space Materials and Environment Engineering Lab, Harbin Institute of Technology, Harbin, 150001 (China); Li Zhijun [39th Institute, China Electronic Science and Technology Groups Inc., Xi-an 710065 (China)

    2005-06-01

    The AG-80 resin is a new type of thermosetting matrix for advanced carbon/epoxy composites. Mass loss effect and the related outgassing are major concerns for its application in space. The changes in mass loss, outgassing and chemical structure under 160 keV proton exposure were investigated for the AG-80 epoxy resin. The variation in chemistry was characterized by X-ray photoelectron spectroscopy. Experimental results show that with increasing the proton fluence, the surface colour of specimens is getting darker. Mass loss ratios ascend remarkably until the fluence of approximately 5.5 x 10{sup 15} cm{sup -2}, and then tend to leveling off. The surface roughness of specimens exhibits an increasing trend followed by decreasing as a function of proton fluence. Under the exposure, the C-C, C-H, C-N and C-O bonds are broken, a variety of molecule ions with smaller molecule weight are formed, and carbon is enriched in the surface layer of specimens. The changes in mass loss and surface roughness of the AG-80 epoxy resin could be attributed to the formation of the molecule ions and the enrichment of carbon content in the surface layer due to proton radiation.

  6. Preparation of highly oriented poly-diacetylene LB-films with ion beam irradiation

    International Nuclear Information System (INIS)

    Hosoi, F.; Aoki, Y.; Hagiwara, M.; Omichi, H.

    1992-01-01

    Langmuir-Blodgett (LB) films such as 10,12-heptacosa-diynoic acid, 10,12-pentacosa-diynoic acid, 10,12-tricosa-diynoic acid were irradiated with ion beam, electron beam and UV-light, and the effect of irradiation on morphology of the polymerized film was studied. A sharp and intense X-ray diffraction pattern with higher order peaks which was not observed in the original films was obtained by Fe + beam irradiation. The interlayer spacing of diacetylene molecules calculated from the X-ray diffraction experiment was much longer than that theoretically anticipated. Similar results were observed when LB-films were treated with Ar + beam of 1keV for a short time although there was little observation of polymerization. In contrast, the diffraction pattern of the films polymerized with UV-light was broad and weak, and higher order peaks disappeared with the increase in irradiation dose. (author)

  7. In-situ field-ion microscope study of the recovery behavior of heavy metal ion-irradiated tungsten, tungsten (rhenium) alloys and molybdenum

    International Nuclear Information System (INIS)

    Nielsen, C.H.

    1977-06-01

    Three field ion microscope (FIM) experiments were carried out to study the annealing behavior of heavy ion irradiated tungsten, tungsten (rhenium) alloys and molybdenum. The first experiment dealt with the stage I long-range migration of tungsten self interstitial atoms (SIAs) in high purity tungsten of resistivity ratio, R = 24,000 (R = rho 300 /rho 4 . 2 , where rho 300 and rho 4 . 2 are the room temperature and 0 0 C resistivities). The FIM specimens were irradiated in situ at 18 K with 30 keV W + ions to an average dose of 5 x 10 12 ions cm -2 and subsequently examined by the pulsed-field evaporation technique. The second experiment dealt with the phenomenon of impurity atom trapping of SIAs during long-range migration. It was shown that rhenium atoms in a tungsten matrix tend to capture tungsten SIAs and remain bound up to temperatures as high as 390 K. The final experiment was concerned with the low temperature annealing kinetics of irradiated molybdenum. High purity molybdenum of resistivity ratio R = 5700 was irradiated at 10 K with 30 keV Mo + ions to a dose of approximately 5 x 10 12 ions cm -2 . The results indicated that the electric field has only a minimal effect on the SIA annealing kinetics. This tends to strengthen the contention that the molybdenum SIA becomes mobile at 32 K

  8. 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.

  9. Production of Mg and Al Auger electrons by noble gas ion bombardment of Mg and Al surfaces. [3 KeV, electron promotion

    Energy Technology Data Exchange (ETDEWEB)

    Ferrante, J; Pepper, S V [National Aeronautics and Space Administration, Cleveland, Ohio (USA). Lewis Research Center

    1976-08-01

    In this letter the relative production efficiency of Mg and Al Auger electrons by He, Ne, Ar, Kr and Xe ion bombardment as a function of ion energy (<=3 keV) is reported. Some comments on the interpretation of the results in terms of electron promotion are also given.

  10. Irradiation effects in Fe-30%Ni alloy during Ar ion implantation

    International Nuclear Information System (INIS)

    Soukieh, Mohamad; Al-Mohamad, Ali

    1993-12-01

    The use of metallic thin films for studying the processes which take place during ion irradiation has recently increased. For example, ion implantation is widely used to study the structural defects in transition metallic thin films such as (Fe, Ni, Co), because it can simulate the effects occurring in nuclear reactors during neutron irradiation especially the swelling of reactor materials. The swelling of metals and alloys is strongly related to the material structure and to the irradiation conditions. The general feature of formation of structural defects as a function of irradiation dosage and annealing temperature is well known. However, the detailed mechanisms are still not well understood. For example, the swelling of iron alloy with 30-35% nickel is very small in comparison with other Ni concentrations, and there is no clear information on the possibility of phase transitions in fe-Ni alloys during irradiation. The aim of this work is to study the phase-structural changes in Fe-30% Ni implanted by high dose of argon ions. The effect of irradiation with low energy argon ions (40 KeV, and fluences of 10.E15 to 10.E17 ions/cm) on the deposited thin films of Fe-30% Ni alloy was investigated using RBS and TEM techniques. The thicknesses of these films were about 65+-10 nm deposited on ceramic, KBr, and Be fiols substrates. Gas bubble formation and profile distribution of the implanted argon ions were investigated. Formation of an ordered phase Fe 3 Ni during irradiation appears to inhibit gas bubble formations in the film structure. (author). 17 refs., 15 figs., 7 tabs

  11. Study of surface activation of PET by low energy (keV) Ni+ and N+ ion implantation

    International Nuclear Information System (INIS)

    Nathawat, Rashi; Kumar, Anil; Kulshrestha, V.; Vijay, Y.K.; Kobayashi, T.; Kanjilal, D.

    2008-01-01

    Polyethyleneterephthalate (PET) has been modified by 100 keV Ni + and N + ions using metal ion from volatile compound (MIVOC) ion source to fluence ranging from 1 x 10 14 to 1 x 10 16 ions/cm 2 . The increasing application of polymeric material in technological and scientific field has motivated the use of surface treatment to modify the physical and chemical properties of polymer surfaces. When a material is exposed to ionization radiation, it suffers damage leading to surface activation depending on the type. The surface morphology was observed by atomic force microscopy (AFM). That show the roughness increases with fluence in both the cases. The Ni particles as precipitation in PET were observed by cross-section transmission electron microscopy (XTEM). The optical band gap (E g ) deduced from absorption spectra; was calculated by Tau'c relation. Raman spectroscopy shows quantitatively the chemical nature at the damage caused by the Ni + and N + bombardment. The ration of I D /I G shows graphite-like structure is formed on the surface. A layer of hydrogenated amorphous carbon is formed on the surface, which has confirmed by XPS results also.

  12. Mechanical design and construction of a 200 mA, 100 keV, DC, negative ion accelerator

    International Nuclear Information System (INIS)

    Purgalis, P.; Anderson, O.A.; Cooper, W.S.; Cummings, C.; Koehler, G.W.; Matuk, C.A.; Wells, R.P.

    1987-01-01

    A volume production source and a 100 keV, dc, accelerator together with an additional, modular, 100 keV, electro static focused accelerator provide a starting point for a high energy H - /D - beamline (200 keV to 800 keV), intended for fusion energy applications. The 100 keV accelerator tests started in June 1987. The mechanical design and construction of the accelerator is described

  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. Dewetting and nanopattern formation of thin Pt films on SiO2 induced by ion beam irradiation

    International Nuclear Information System (INIS)

    Hu, Xiaoyuan; Cahill, David G.; Averback, Robert S.

    2001-01-01

    Dewetting and nanopattern formation of 3 - 10 nm Pt thin films upon ion irradiation is studied using scanning electron microscopy (SEM). Lateral feature size and the fraction of exposed surface area are extracted from SEM images and analyzed as functions of ion dose. The dewetting phenomenon has little temperature dependence for 3 nm Pt films irradiated by 800 keV Kr + at temperatures ranging from 80 to 823 K. At 893 K, the films dewet without irradiation, and no pattern formation is observed even after irradiation. The thickness of the Pt films, in the range 3 - 10 nm, influences the pattern formation, with the lateral feature size increasing approximately linearly with film thickness. The effect of different ion species and energies on the dewetting process is also investigated using 800 keV Kr + and Ar + irradiation and 19.5keVHe + , Ar + , Kr + , and Xe + irradiation. The lateral feature size and exposed surface fraction scale with energy deposition density (J/cm2) for all conditions except 19.5keVXe + irradiation. [copyright] 2001 American Institute of Physics

  16. 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%

  17. Boron ion irradiation induced structural and surface modification of glassy carbon

    International Nuclear Information System (INIS)

    Kalijadis, Ana; Jovanović, Zoran; Cvijović-Alagić, Ivana; Laušević, Zoran

    2013-01-01

    The incorporation of boron into glassy carbon was achieved by irradiating two different types of targets: glassy carbon polymer precursor and carbonized glassy carbon. Targets were irradiated with a 45 keV B 3+ ion beam in the fluence range of 5 × 10 15 –5 × 10 16 ions cm −2 . For both types of targets, the implanted boron was located in a narrow region under the surface. Following irradiation, the polymer was carbonized under the same condition as the glassy carbon samples (at 1273 K) and examined by Raman spectroscopy, temperature programmed desorption, hardness and cyclic voltammetry measurements. Structural analysis showed that during the carbonization process of the irradiated polymers, boron is substitutionally incorporated into the glassy carbon structure, while for irradiated carbonized glassy carbon samples, boron irradiation caused an increase of the sp 3 carbon fraction, which is most pronounced for the highest fluence irradiation. Further analyses showed that different nature of boron incorporation, and thus changed structural parameters, are crucial for obtaining glassy carbon samples with modified mechanical, chemical and electrochemical properties over a wide range

  18. 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

  19. Calculated and measured W values in N2, Ar, CH4 and CO2 gases for ions H+, He+, C+, N+, O+ and Ar+ in the energy range 25 KeV to 375 KeV

    International Nuclear Information System (INIS)

    Nguyen Van Dat; Chemtob, Maurice.

    1979-01-01

    The present paper describes the experimental method used for measurement of W values in argon gas and in the three components of T.E. gas: nitrogen, methane and carbon dioxide, for ions with masses in the range 1 to 40 a.m.u. and with energies in the range 25 KeV to 375 KeV. For these ions, the incident velocities are comparable to the electron orbital velocities. At these velocities energy losses due to elastic scattering and electron capture processes are expected to become significant as compared to ionization and excitation which predominate at higher velocities. These measured W values are then compared to calculated values. These calculations are obtained by introducing the inelastic and elastic stopping power cross sections in a transport equation, the resolution of which gives ionization range and the amount of energy released to produce ionization

  20. 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

  1. Secondary ion emission from metal surfaces bombarded by 0.5-10 keV protons and hydrogens

    International Nuclear Information System (INIS)

    Kitamura, Akira; Yano, Syukuro

    1978-01-01

    Secondary ion emission coefficients by bombardment of 0.5 - 10 keV protons K 11 and atomic hydrogens K 01 on copper, stainless steel, molybdenum and evaporated gold surfaces have been measured in a moderate vacuum. Results are summarized as follows; 1) There is no significant difference between K 11 and K 01 . 2) Differences in K 11 and K 11 between different samples of the same material and between the sample before baking-out and the same sample after baking-out are of the order of several tens of percent. 3) The incident particle energy E sub(max) at which K 11 and K 01 have the maximum value lies in the keV region, and increases with the target mass. According to the fact that E sub(max) differs substantially from the energy at which the elastic stopping power has the maximum value, a characteristic length l is introduced and calculated to be of the order of hundreds of A; the factor exp (-x/l) represents the degree of contribution of collision at depth x to K 11 or K 01 . (author)

  2. Dense ion clouds of 0.1 − 2 keV ions inside the CPS-region observed by Astrid-2

    Directory of Open Access Journals (Sweden)

    O. Norberg

    Full Text Available Data from the Astrid-2 satellite taken between April and July 1999 show several examples of dense ion clouds in the 0.1–2 keV energy range inside the inner mag-netosphere, both in the northern and southern hemispheres. These inner magnetospheric ion clouds are found predomi-nantly in the early morning sector, suggesting that they could have originated from substorm-related ion injections on the night side. However, their location and density show no cor-relation with Kp, and their energy-latitude dispersion is not easily reproduced by a simple particle drift model. There-fore, these ion clouds are not necessarily caused by substorm-related ion injections. Alternative explanations for the ion clouds are the direct solar wind injections and up-welling ions from the other hemisphere. These explanations do not, however, account for all of the observations.Key words. Magnetospheric physics (energetic particles, trapped; magnetospheric configuration and dynamics; storm and substorms

  3. 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)

  4. Impact-parameter dependence of energy loss for 625-keV H+ ions in Si single crystals

    International Nuclear Information System (INIS)

    Dygo, A.; Boshart, M.A.; Seiberling, L.E.; Kabachnik, N.M.

    1994-01-01

    The energy distributions for 625-keV H + ions transmitted through thin Si single crystals are studied for detailed angular scans through the left-angle 110 right-angle and left-angle 100 right-angle axial as well as the {111} and {110} planar channels. Well-resolved structures in the distributions taken near the left-angle 110 right-angle axial direction are observed. The experimental energy-loss distributions are very well reproduced by a Monte Carlo simulation using the semiclassical approximation model for core electrons and the two-component free-electron-gas model for valence electrons. The best fit to the data is obtained if the model energy losses are scaled up for core electrons and down for valence electrons by several percent. The experimental distributions can also be reproduced by assuming the mean excitation energy for distant collisions of the ion with core electrons equal to 1.4 times the binding energy for a given shell. No significant differences between the distributions obtained using the solid-state and free-atom valence electron densities have been found. The evolution of the distributions for the left-angle 110 right-angle axial scan is discussed in terms of ion trajectories and the flux distribution. Also, the azimuthally averaged mean energy loss is studied as a function of tilt angle with respect to the left-angle 110 right-angle axis

  5. Formation of nanodots and enhancement of thermoelectric power induced by ion irradiation in PbTe:Ag composite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bala, Manju, E-mail: manjubala474@gmail.com [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Meena, Ramcharan; Gupta, Srashti; Pannu, Compesh [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Tripathi, Tripurari S. [Aalto University, Värmemansgränden 2, 02150 Espoo (Finland); Varma, Shikha [Institute of Physics, Bhubaneshwar, Odisha 751005 (India); Tripathi, Surya K. [Department of Physics, Panjab University, Chandigarh 160 014 (India); Asokan, K., E-mail: asokaniuac@gmail.com [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Avasthi, Devesh K. [Amity University, Noida 201313, Uttar Pradesh (India)

    2016-07-15

    Present study demonstrates an enhancement in thermoelectric power of 10% Ag doped PbTe (PbTe:Ag) thin films when irradiated with 200 keV Ar ion. X-ray diffraction showed an increase in crystallinity for both PbTe and PbTe:10Ag nano-composite films after Ar ion irradiation due to annealing of defects in the grain boundaries. The preferential sputtering of Pb and Te ions in comparison to Ag ions resulted in the formation of nano-dots. This was further confirmed by X-ray photoelectron spectroscopy (XPS). Such an enhancement in thermoelectric power of irradiated PbTe:10Ag films in comparison to pristine PbTe:10Ag film is attributed to the decrease in charge carrier concentration that takes part in the transport process via restricting the tunneling of carriers through the wider potential barrier formed at the interface of nano-dots.

  6. In situ thin film measurement by X-rays induced by 10 KeV-100 KeV ion beams

    International Nuclear Information System (INIS)

    Torrisi, L.; Calcagno, L.; Trovato, A.; Foti, G.

    1982-01-01

    The in situ measurement of thin film thickness between 50 and 100 KeV is described. The method used seems to be flexible enough and can be applied to any type of material. The only parameter intervening in the thickness measurement is the specific energy loss of the proton beams. Film of Al, Cu and Ag have been considered. When the primary beam energy increases the perception in depth of the method grows, reaching 10 μm with 1 MeV beam. In this case the autoabsorption takes place

  7. Modification of μm thick surface layers using keV ion energies

    International Nuclear Information System (INIS)

    Rehn, L.E.; Lam, N.Q.; Wiedersich, H.

    1983-11-01

    Root-mean-square diffusion distances for both vacancy and interstitial defects in metals can be very large at elevated temperatures, e.g. several μm's in one second at 500 0 C. Consequently, defects that escape the implanted region at elevated temperature can produce conpositional and microstructural changes to depths which are much larger than the ion range. Because of the high defect mobilities, and of the fact that diffusion processes must compete with the rate of surface recession, the effects of defect production (ballistic mixing), radiation-enhanced diffusion and radiation-induced segregation become spatially separated during ion bombardment at elevated temperature. Results of such experimental studies in a Cu-Ni alloy are presented, discussed and compared with predictions of a phenomenological model. Contributions to the subsurface compositional changes from radiation-enhanced diffusion and radiation-induced segregation are clearly identified

  8. Stopping powers of gases for ions of energy below 200 keV

    International Nuclear Information System (INIS)

    Fukuda, Akira

    1978-01-01

    There has been renewed interest in the stopping power of matters for ions in low energy region. But there is not an established theory in this energy region, and experimental data did not coincide with the curves in some data books. Therefore, precise experimental measurement is still necessary. In present neutron dosimetry, tissues are the object of measurement of absorbed dose. In this experiment, it was intended to use tissue equivalent gas as a target gas. In the experimental apparatus, ions come from the Cockcroft-Walton accelerator are applied to the cell, in which the target gas is admitted from gas source. Gas in the cell is observed with the electrostatic energy analyzer. Stopping power is calculated from the results of energy loss measurement. In this report, only the preliminary results are shown. The tissue equivalent gas is composed of CH 4 , CO 2 and N 2 , each percentage is 64.95, 32.2 and 2.85, respectively. It seems that the stopping powers of noble gases will be useful for the developments of the theory, and the stopping power for He + ions was measured. The results are shown in a figure, and the errors were estimated to be less than 1.5%. At the end of the report, some discussions among a few persons are added. (Wakatsuki, Y.)

  9. Ion-irradiation induced chemical ordering of FePt and FePtAu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Seetala, Naidu V. [Department of Physics, Grambling State University, RWE Jones Drive, Carver Hall 81, Grambling, LA 71245 (United States)]. E-mail: naidusv@gram.edu; Harrell, J.W. [MINT Center, University of Alabama, Tuscaloosa, AL 35487 (United States); Lawson, Jeremy [MINT Center, University of Alabama, Tuscaloosa, AL 35487 (United States); Nikles, David E. [MINT Center, University of Alabama, Tuscaloosa, AL 35487 (United States); Williams, John R. [Department of Physics, Auburn University, Auburn, AL 36849 (United States); Isaacs-Smith, Tamara [Department of Physics, Auburn University, Auburn, AL 36849 (United States)

    2005-12-15

    We have studied the effect of ion-beam irradiation on reducing the ordering temperature of FePt and FePtAu nanoparticles. FePt and FePt(Au14%) 4 nm particles dispersed on a Si-substrate were irradiated by 300 keV Al-ions with a dose of 1 x 10{sup 16} ions/cm{sup 2} at 43 {sup o}C using a water-cooled flange in order to minimize the vacancy migration and voids formation within the collision cascades. Partial chemical ordering has been observed in as-irradiated particles with coercivity of 60-130 Oe. Post-irradiation annealing at 220 {sup o}C enhanced chemical ordering in FePt nanoparticles with coercivity of 3500 Oe, magnetic anisotropy of 1.5 x 10{sup 7} erg/cc, and thermal stability factor of 130. A much higher 375 {sup o}C post-irradiation annealing was required in FePtAu, presumably because Au atoms were trapped at Fe/Pt lattice sites at lower temperatures. As the annealing temperature increased, anomalous features in the magnetization reversal curves were observed that disappeared at higher annealing temperatures.

  10. Recoil-ion fractions in collisions of keV Ar sup + and Kr sup + ions with clean and adsorbate covered GaAs(1 1 0) surfaces

    CERN Document Server

    Gayone, J E; Grizzi, O; Vergara, L I; Passeggi, M C G; Vidal, R; Ferron, J

    2002-01-01

    Ion scattering and recoiling spectroscopy with time of flight analysis is used to study the ion fractions of Ga and As atoms recoiled in collisions of 5 keV Ar sup + and Kr sup + with clean GaAs(1 1 0) and with GaAs(1 1 0) covered with H, alkali metals (K and Cs) and fluorides (AlF sub 3). For the case of the clean surface, the Ga ion fraction is positive, large (approx 50%) and independent of the projectile type. The As ion fraction is also positive, low for Ar sup + (<10%) and relatively large (25%) for Kr sup + projectiles. The adsorption of H produces slight changes in both the As and Ga ion fractions, which is in agreement with the adsorption model where H reacts with both As and Ga atoms. The adsorption of alkalis produces strong changes in the ion fractions. At the beginning of the alkali adsorption the neutralization of Ga recoils increases fast with the coverage and follows approximately the variation of the work function. At coverages above half of the saturation value, where the work function ha...

  11. Phase formation in Zr/Fe multilayers during Kr ion irradiation

    International Nuclear Information System (INIS)

    Motta, A. T.

    1998-01-01

    A detailed study has been conducted of the effect of Kr ion irradiation on phase formation in Zr-Fe metallic multilayers, using the Intermediate Voltage Electron Microscopy (IVEM) at Argonne National Laboratory. Metallic multilayers were prepared with different overall compositions (near 50-50 and Fe-rich), and with different wavelengths (repetition thicknesses). These samples were irradiated with 300 keV Kr ions at various temperatures to investigate the final products, as well as the kinetics of phase formation. For the shorter wavelength samples, the final product was in all cases an amorphous Zr-Fe phase, in combination with Fe, while specially for the larger wavelength samples, in the Fe-rich samples the intermetallic compounds ZrFe 2 and Zr 3 Fe were formed in addition to the amorphous phase. The dose to full reaction decreases with temperature, and with wavelength in a manner consistent with a diffusion-controlled reaction

  12. Annealing of ion irradiated high TC Josephson junctions studied by numerical simulations

    International Nuclear Information System (INIS)

    Sirena, M.; Matzen, S.; Bergeal, N.; Lesueur, J.; Faini, G.; Bernard, R.; Briatico, J.; Crete, D. G.

    2009-01-01

    Recently, annealing of ion irradiated high T c Josephson iunctions (JJs) has been studied experimentally in the perspective of improving their reproducibility. Here we present numerical simulations based on random walk and Monte Carlo calculations of the evolution of JJ characteristics such as the transition temperature T c ' and its spread ΔT c ' , and compare them with experimental results on junctions irradiated with 100 and 150 keV oxygen ions, and annealed at low temperatures (below 80 deg. C). We have successfully used a vacancy-interstitial annihilation mechanism to describe the evolution of the T c ' and the homogeneity of a JJ array, analyzing the evolution of the defects density mean value and its distribution width. The annealing first increases the spread in T c ' for short annealing times due to the stochastic nature of the process, but then tends to reduce it for longer times, which is interesting for technological applications

  13. Study of point defect clustering in electron and ion irradiated zirconium alloys

    International Nuclear Information System (INIS)

    Hellio, C.; Boulanger, L.

    1986-09-01

    Dislocation loops created by 500 keV Zr + ions and 1 MeV electrons in zirconium have a/3 type Burgers vectors, and in ion irradiated samples, loops lie preferentially on planes close to (1010). From in-situ observations of loop growth under 1 MeV electron irradiation in zirconium and dilute Zr (Nb,O) alloys, a strong increase of the vacancy migration energy with oxygen concentration was observed, from 0.72 eV for pure zirconium to 1.7 eV for Zr and Zr-1% Nb doped with 1800 ppm weight oxygen, indicating large trapping of vacancies by O single interstitials or clusters

  14. A NEXAFS and mass spectrometry study of cysteine, cystine and insulin irradiated with intermediate energy (0.8 keV) electrons

    Energy Technology Data Exchange (ETDEWEB)

    Simões, G., E-mail: simoes.grazieli@gmail.com [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil); Rodrigues, F.N. [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil); Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Maracanã, 20270-021 Rio de Janeiro (Brazil); Bernini, R.B. [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil); Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Duque de Caxias, 25050-100 Rio de Janeiro (Brazil); Castro, C.S.C. [Instituto Nacional de Metrologia, Qualidade e Tecnologia – Inmetro, 25250-020 Rio de Janeiro (Brazil); Souza, G.G.B. de, E-mail: gerson@iq.ufrj.br [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil)

    2014-03-01

    Highlights: • Structural modifications in sulfur containing biomolecules were investigated. • Significant modifications were observed in insulin irradiated NEXAFS spectra. • Degradation of insulin can be observed even at low temperature. • Alterations in insulin spectrum were characterized according to the state of sulfur. - Abstract: We have performed a NEXAFS (S 1s) and mass spectrometry study of solid samples of cysteine, cystine and insulin irradiated with 0.8 keV electrons. The measured mass spectra point out to processes of desulfurization, deamination, decarbonylation and decarboxylation in the irradiated biomolecules. Electron beam irradiation was also conducted at low temperatures in order to evaluate the possible contribution from thermal degradation processes. The NEXAFS spectra of irradiated cysteine and cystine did not show substantial changes when compared to the same spectra obtained using non-irradiated samples. The sulfur K-edge photoabsorption spectrum of irradiated insulin, however, showed clear modifications when compared to the spectrum of the non-irradiated protein, even when the irradiation was conducted at low temperature. Using an empirical combination of the photoabsorption spectra of cysteine and cystine (which are associated respectively with reduced and oxidized forms of sulfur) we have been able to reproduce the absorption spectrum of irradiated insulin.

  15. Photocarrier radiometry for predicting the degradation of electrical parameters of monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Song, P. [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Liu, J.Y., E-mail: ljywlj@hit.edu.cn [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); State Key Laboratory of Robotics and System (HIT), Harbin 150001 (China); Yuan, H.M.; Oliullah, Md.; Wang, F. [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Y., E-mail: songpengkevin@126.com [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); State Key Laboratory of Robotics and System (HIT), Harbin 150001 (China)

    2016-09-15

    In this study, the monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams at various fluences is investigated. A one-dimensional two-layer carrier density wave model has been developed to estimate the minority carrier lifetime of n-region and p-region of the non-irradiated c-Si solar cell by best fitting with the experimental photocarrier radiometry (PCR) signal (the amplitude and the phase). Furthermore, the lifetime is used to determine the initial defect density of the quasi-neutral region (QNR) of the solar cell to predict its I–V characteristics. The theoretically predicted short-circuit current density (J{sub sc}), and open-circuit voltage (V{sub oc}) of the non-irradiated samples are in good agreement with experiment. Then a three-region defect distribution model for the c-Si solar cell irradiated by proton beams is carried out to describe the defect density distribution according to Monte Carlo simulation results and the initial defect density of the non-irradiated sample. Finally, we find that the electrical measurements of J{sub sc} and V{sub oc} of the solar cells irradiated at different fluences using 100 KeV proton beams are consistent with the PCR predicting results.

  16. Photocarrier radiometry for predicting the degradation of electrical parameters of monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams

    International Nuclear Information System (INIS)

    Song, P.; Liu, J.Y.; Yuan, H.M.; Oliullah, Md.; Wang, F.; Wang, Y.

    2016-01-01

    In this study, the monocrystalline silicon (c-Si) solar cell irradiated by 100 KeV proton beams at various fluences is investigated. A one-dimensional two-layer carrier density wave model has been developed to estimate the minority carrier lifetime of n-region and p-region of the non-irradiated c-Si solar cell by best fitting with the experimental photocarrier radiometry (PCR) signal (the amplitude and the phase). Furthermore, the lifetime is used to determine the initial defect density of the quasi-neutral region (QNR) of the solar cell to predict its I–V characteristics. The theoretically predicted short-circuit current density (J_s_c), and open-circuit voltage (V_o_c) of the non-irradiated samples are in good agreement with experiment. Then a three-region defect distribution model for the c-Si solar cell irradiated by proton beams is carried out to describe the defect density distribution according to Monte Carlo simulation results and the initial defect density of the non-irradiated sample. Finally, we find that the electrical measurements of J_s_c and V_o_c of the solar cells irradiated at different fluences using 100 KeV proton beams are consistent with the PCR predicting results.

  17. 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

  18. Experimental study of interactions of highly charged ions with atoms at keV energies. Progress report, February 16, 1993--April 15, 1994

    International Nuclear Information System (INIS)

    Kostroun, V.O.

    1994-01-01

    Experimental study of low energy, highly charged ions with other atomic species requires an advanced ion source such as an electron beam ion source, EBIS or an electron cyclotron ion source, ECRIS. Five years ago we finished the design and construction of the Cornell superconducting solenoid, cryogenic EBIS (CEBIS). Since then, this source has been in continuous operation in a program whose main purpose is the experimental study of interactions of highly charged ions with atoms at keV energies. This progress report for the period February 16, 1993 to April 15, 1994 describes the work accomplished during this time in the form of short abstracts

  19. 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.

  20. 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)

  1. 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.

  2. Momenta of particles emitted by target at intensive irradiation by low-energy ions

    CERN Document Server

    Beshenkov, V G; Marchenko, V A

    2002-01-01

    One measured the aggregate momenta of the target emitted particles at the intensive sputtering by E sub 0 approx = 0.5 keV energy heavy inert gases. For liquid and being under premelting temperature Ga target the measured values are close to the expected momenta of sputtered metallic atoms and reflection ions, for Cu and Zr targets they are essentially higher. One assumes that sputtering of atoms of gas-diffuser implanted into the target causes the surplus momentum. The estimated average energy of these atoms approx = 20 eV. Under Ga irradiation the implanted atoms diffuse mainly towards the surface and are desorbed

  3. Damage evolution in Xe-ion irradiated rutile (TiO2) single crystals

    International Nuclear Information System (INIS)

    Li, F.; Sickafus, K.E.; Evans, C.R.; Nastasi, M.

    1999-01-01

    Rutile (TiO 2 ) single crystals with (110) orientation were irradiated with 360 keV Xe 2+ ions at 300 K to fluences ranging from 2 x 10 19 to 1 x 10 20 Xe/m 2 . Irradiated samples were analyzed using: (1) Rutherford backscattering spectroscopy combined with ion channeling analysis (RBS/C); and (2) cross-sectional transmission electron microscopy (XTEM). Upon irradiation to a fluence of 2 x 10 19 Xe/m 2 , the sample thickness penetrated by the implanted ions was observed to consist of three distinct layers: (1) a defect-free layer at the surface (thickness about 12 nm) exhibiting good crystallinity; (2) a second layer with a low density of relatively large-sized defects; and (3) a third layer consisting of a high concentration of small defects. After the fluence was increased to 7 x 10 19 Xe/m 2 , a buried amorphous layer was visible by XTEM. The thickness of the amorphous layer was found to increase with increasing Xe ion fluence. The location of this buried amorphous layer was found to coincide with the measured peak in the Xe concentration (measured by RBS/C), rather than with the theoretical maximum in the displacement damage profile. This observation suggests the implanted Xe ions may serve as nucleation sites for the amorphization transformation. The total thickness of the damaged microstructure due to ion irradiation was always found to be much greater than the projected range of the Xe ions. This is likely due to point defect migration under the high stresses induced by ion implantation

  4. Radiation-induced effects in MgO single crystal by 200 keV and 1 MeV Ni ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryohei; Nakai, Yoshihiro; Hamaguchi, Dai [Kyoto Inst. of Tech. (Japan); and others

    1997-03-01

    MgO(100) single crystals were implanted with 1.0 MeV and 200 keV Ni ions between 10{sup 15} and 10{sup 17} ions/cm{sup 2} at room temperature. Before and after thermal annealing the radiation damage and the lattice location of implanted Ni ions were analyzed by using Rutherford backscattering spectrometry with channeling and optical absorption measurements. For 1.0 MeV Ni ions, the disorder of Mg atoms increased slowly with ion dose near surface region, while it increased sharply and saturated with ion dose from 2x10{sup 16} ions/cm{sup 2} near ion range. The radiation damage was recovered and implanted Ni ions diffused to the whole of crystal and occupied substitutional positions after 1400degC annealing. For 200 keV Ni ions, the disorder of Mg atoms increased with dose near ion range and had a maximum at about 5x10{sup 16} ions/cm{sup 2}. This tendency agrees with the behavior of color centers obtained from optical measurements. For thermal annealing the radiation damage did not change during 500degC annealing, but the aggregate centers appeared after 300degC annealing. (author)

  5. Enhanced electrical conductivity in Xe ion irradiated CNT based transparent conducting electrode on PET substrate

    Science.gov (United States)

    Surbhi; Sharma, Vikas; Singh, Satyavir; Garg, Priyanka; Asokan, K.; Sachdev, Kanupriya

    2018-02-01

    An investigation of MWCNT-based hybrid electrode films with improved electrical conductivity after Xe ion irradiation is reported. A multilayer hybrid structure of Ag-MWCNT layer embedded in between two ZnO layers was fabricated and evaluated, pre and post 100 keV Xe ion irradiation, for their performance as Transparent Conducting Electrode in terms of their optical and electrical properties. X-ray diffraction pattern exhibits highly c-axis oriented ZnO films with a small variation in lattice parameters with an increase in ion fluence. There is no significant change in the surface roughness of these films. Raman spectra were used to confirm the presence of CNT. The pristine multilayer films exhibit an average transmittance of ˜70% in the entire visible region and the transmittance increases with Xe ion fluence. A significant enhancement in electrical conductivity post-Xe ion irradiation viz from 1.14 × 10-7 Ω-1 cm-1 (pristine) to 7.04 × 103 Ω-1 cm-1 is seen which is due to the high connectivity in the top layer with Ag-CNT hybrid layer facilitating the smooth transfer of electrons.

  6. A low background-rate detector for ions in the 5 to 50 keV energy range to be used for radioisotope dating with a small cyclotron

    International Nuclear Information System (INIS)

    Friedman, P.G.

    1986-01-01

    Accelerator mass spectrometry in tandem Van de Graaff accelerators has proven successful for radioisotope dating small samples. We are developing a 20 cm diameter 30 to 40 keV cyclotron dedicated to high-sensitivity radioisotope dating, initially for 14 C. At this energy, range and dE/dx methods of particle identification are impossible. Thus arises the difficult problem of reliably detecting 30 to 40 keV 14 C at 10 -2 counts/sec in the high background environment of the cyclotron, where lower energy ions, electrons, and photons bombard the detector at much higher rates. We have developed and tested an inexpensive, generally useful ion detector that allows dark-count rates below 10 -4 counts/sec and excellent background suppression. With the cyclotron tuned near the 13 CH background peak, to the frequency for 14 C, the detector suppresses the background to 6 x 10 -4 counts/sec. For each 14 C ion the detectors grazing-incidence Al 2 O 3 conversion dynode emits about 20 secondary electrons, which are independently multiplied in separate pores of a microchannel plate. The output signal is proportional to the number of secondary electrons, allowing pulse-height discrimination of background. We have successfully tested the detector with positive 12 C, 23 Na, 39 K, 41 K, 85 Rb, 87 Rb, and 133 Cs at 5 to 40 keV, and with 36 keV negative 12 C and 13 CH. It should detect ions and neutrals of all species, at energies above 5 keV, with good efficiency and excellent background discrimination. Counting efficiency and background discrimination improve with higher ion energy. The detector can be operated at least up to 2 x 10 -7 Torr and be repeatedly exposed to air. The maximum rate is 10/sup 6.4/ ions/sec in pulse counting mode and 10/sup 9.7/ ions/sec in current integrating mode

  7. Range measurements of keV hydrogen ions in solid oxygen and carbon monoxide

    International Nuclear Information System (INIS)

    Schou, J.; Soerensen, H.; Andersen, H.H.; Nielsen, M.; Rune, J.

    1984-01-01

    Ranges of 1.3-3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen. The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result agrees with that previously found for solid nitrogen. (orig.)

  8. Direct observation of the point-defect structure of depleted-zones in ion-irradiated metals

    International Nuclear Information System (INIS)

    Wei, C.

    1978-01-01

    The point-defect structure of individual depleted zones has been studied systematically. Four-pass zone-refined tungsten field-ion microscope (FIM) specimens were irradiated in-situ at 10 K with 30 keV Cr + , Mo + , or W + ions to a total dose of (2 to 10) x 10 12 ion cm -2 and examined by the pulse field-evaporation technique at 10 K. The experimental conditions were such that each depleted zone was created by a single incident-ion. The number of vacant lattice sites within a depleted zone was compared with a modified Kinchin--Pease model. The radial distribution function was determined for each depleted zone; it was found that the vacant lattice sites within the volume of each depleted zone tended to exist in a highly clustered state. It was found that the diameter D of each depleted zone was described by the equation D approximately equal to [y 2 ]/sup 1 / 2 / where [y 2 ]/sup 1 / 2 / is the second moment of the theoretical distribution curve, of the fraction of incident ion energy deposited in atom motion, transverse to the direction of the incident ion-beam. The spatial distribution of self-interstitial atoms (SIAs) in a specimen irradiated with 30 keV Cr + ions and in a specimen irradiated with 18 keV Au + ions, at 10 K, was determined. A low bound to the average range of replacement collision sequences (RCSs) was found to be 175 +- 85 A. A detailed FIM study was also made of the vacancy structure of a (220) platelet created by a single 30 keV W + ion in a platinum-4.0 at. % gold alloy; the specimen was irradiated at 40 K and then isochronally warmed to 100 K. The (220) platelet was found to consist of 31 vacant lattice sites, lying in four (220) planes, and clustered in a disc-shaped region which is approximately 20 A in diameter. It was suggested that prismatic dislocation loops lying on (220) type planes in ion or fast neutron irradiated platinum can form as a result of the direct collapse of (220) type vacancy platelets

  9. 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)

  10. 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)

  11. Reduction and structural modification of zirconolite on He{sup +} ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Merry, E-mail: g41merry@gmail.com [Sant Longowal Institute of Engineering and Technology, Longowal, Sangrur, Punjab 148106 (India); Kulriya, P.K. [Inter-University Accelerator Centre, Aruna Asaf Ali Road, New Delhi 110067 (India); Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Shukla, Rishabh; Dhaka, R.S. [Novel Materials and Interface Physics Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Kumar, Raj [Inter-University Accelerator Centre, Aruna Asaf Ali Road, New Delhi 110067 (India); Ghumman, S.S. [Sant Longowal Institute of Engineering and Technology, Longowal, Sangrur, Punjab 148106 (India)

    2016-07-15

    The immobilization of minor actinides and alkaline-earth metal is a major concern in nuclear industry due to their long-term radioactive contribution to the high level waste (HLW). Materials having zirconolite, pyrochlore, and perovskite structure are promising candidates for immobilization of HLW. The zirconolite which exhibits high radiation stability and corrosion resistance behavior is investigated for its radiation stability against alpha particles in the present study. CaZrTi{sub 2}O{sub 7} pellets prepared using solid state reaction techniques, were irradiated with 30 keV He{sup +} ions for the ion fluence varying from 1 × 10{sup 17} to 1 × 10{sup 21} ions/m{sup 2}. Scanning electron microscopy (SEM) images of the un-irradiated sample exhibited well separated grains with average size of about 6.8 μm. On the ion irradiation, value of the average grains size was about 7.1 μm, and change in the microstructure was insignificant. The X-ray photoelectron spectroscopy (XPS) studies showed a shift in the core level peak position (of Ca 2p, Ti 2p and Zr 3d) towards lower binding energy with respect to pristine sample as well as loss of oxygen was also observed for sample irradiated with the ion fluence of 1 × 10{sup 20} ions/m{sup 2}. These indicate a decrease in co-ordination number and the ionic character of M−O bond. Moreover, core level XPS signal was not detected for sample irradiated with ion fluence of 1 × 10{sup 21} ions/m{sup 2}, suggesting surface damage of the sample at this ion fluence. However, X-ray diffraction (XRD) studies showed that zirconolite was not amorphized even on irradiation up to a fluence order of 1 × 10{sup 21} ion/m{sup 2}. But, significant decrease in peak intensity due to creation of defects and a marginal positive peak shift due to tensile strain induced by irradiation, were observed. Thus, XRD along with XPS investigation suggests that reduction, decrease in co-ordination number, and increase in covalency are responsible for

  12. Ion irradiation of the Murchison meteorite: Visible to mid-infrared spectroscopic results

    Science.gov (United States)

    Lantz, C.; Brunetto, R.; Barucci, M. A.; Dartois, E.; Duprat, J.; Engrand, C.; Godard, M.; Ledu, D.; Quirico, E.

    2015-05-01

    Aims: The goal of this study is to simulate space weathering processes on primitive bodies. We use ion implantation as a simulation of solar wind irradiation, which has been suggested by several authors to be the major component of space weathering on main belt asteroids. The laboratory analogs we irradiate and analyze are carbonaceous chondrites; we started the study with the Allende CV meteorite and in this companion paper we present results on the Murchison CM meteorite. Methods: We performed irradiations on pressed pellets of Murchison with 40 keV He+ and Ar+ ions using fluences up to 3 × 1016 ions/cm2. Reflectance spectra were acquired ex situ before and after irradiation in the visible to mid-infrared range (0.4-16 μm). A Raman analysis was also performed to investigate the modifications of the aromatic carbonaceous component. Results: Our results indicate that spectral variations after irradiation within the visible range are smaller than spectral variations due to sample grain size or viewing geometry of the Murchison meteorite. The aqueous alteration band profile near 3 μm changes after irradiation, as adsorbed water is removed, and phyllosilicates are affected. Raman spectroscopy highlights the insoluble organic matter (IOM) modification under irradiation. We observe a shift of the silicates band at 9.9 μm, probably due to a preferential loss of Mg (compared to Fe, the lighter Mg is more easily sputtered backward) and/or amorphization of Mg-rich materials. We compare our results to previous experiments on organic-rich materials (like asphaltite or carbonaceous chondrites), and on ordinary chondrites and olivine grains. We find that the reddening/darkening trend observed on silicate-rich surfaces is not valid for all carbonaceous chondrites, and that the spectral modifications after irradiation are a function of the initial albedo.

  13. Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

    International Nuclear Information System (INIS)

    Poudel, P.R.; Poudel, P.P.; Paramo, J.A.; Strzhemechny, Y.M.; Rout, B.; McDaniel, F.D.

    2015-01-01

    The structural and optical properties of carbon nanoclusters formed in thermally grown silicon dioxide film via the ion beam synthesis process have been investigated. A low-energy (70 keV) carbon ion beam (C - ) at a fluence of 3 x 10 17 atoms/cm 2 was used for implantation into a thermally grown silicon dioxide layer (500 nm thick) on a Si (100) wafer. Several parts of the implanted samples were subsequently annealed in a gas mixture (4 % H 2 + 96 % Ar) at 900 C for different time periods. The as-implanted and annealed samples were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL). The carbon ion implantation depth profile was simulated using a widely used Monte Carlo-based simulation code SRIM-2012. Additionally, the elemental depth profile of the implanted carbon along with host elements of silicon and oxygen were simulated using a dynamic ion-solid interaction code T-DYN, which incorporates the effects of the surface sputtering and gradual change in the elemental composition in the implanted layers due to high-fluence ion implantation. The elemental depth profile obtained from the XPS measurements matches closely to the T-DYN predictions. Raman measurements indicate the formation of graphitic phases in the annealed samples. The graphitic peak (G-peak) was found to be increased with the annealing time duration. In the sample annealed for 10 min, the sizes of the carbon nanoclusters were found to be 1-4 nm in diameter using TEM. The PL measurements at room temperature using a 325-nm laser show broad-band emissions in the ultraviolet to visible range in the as-implanted sample. Intense narrow bands along with the broad bands were observed in the annealed samples. The defects present in the as-grown samples along with carbon ion-induced defect centers in the as-implanted samples are the main contributors to the observed

  14. Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Poudel, P.R. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States); Intel Corporation, Rio Rancho, NM (United States); Poudel, P.P. [University of Kentucky, Department of Chemistry, Lexington, KY (United States); Paramo, J.A.; Strzhemechny, Y.M. [Texas Christian University, Department of Physics and Astronomy, Fort Worth, TX (United States); Rout, B. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States); University of North Texas, Center for Advanced Research and Technology, Denton, TX (United States); McDaniel, F.D. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States)

    2014-09-18

    The structural and optical properties of carbon nanoclusters formed in thermally grown silicon dioxide film via the ion beam synthesis process have been investigated. A low-energy (70 keV) carbon ion beam (C{sup -}) at a fluence of 3 x 10{sup 17} atoms/cm{sup 2} was used for implantation into a thermally grown silicon dioxide layer (500 nm thick) on a Si (100) wafer. Several parts of the implanted samples were subsequently annealed in a gas mixture (4 % H{sub 2} + 96 % Ar) at 900 C for different time periods. The as-implanted and annealed samples were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL). The carbon ion implantation depth profile was simulated using a widely used Monte Carlo-based simulation code SRIM-2012. Additionally, the elemental depth profile of the implanted carbon along with host elements of silicon and oxygen were simulated using a dynamic ion-solid interaction code T-DYN, which incorporates the effects of the surface sputtering and gradual change in the elemental composition in the implanted layers due to high-fluence ion implantation. The elemental depth profile obtained from the XPS measurements matches closely to the T-DYN predictions. Raman measurements indicate the formation of graphitic phases in the annealed samples. The graphitic peak (G-peak) was found to be increased with the annealing time duration. In the sample annealed for 10 min, the sizes of the carbon nanoclusters were found to be 1-4 nm in diameter using TEM. The PL measurements at room temperature using a 325-nm laser show broad-band emissions in the ultraviolet to visible range in the as-implanted sample. Intense narrow bands along with the broad bands were observed in the annealed samples. The defects present in the as-grown samples along with carbon ion-induced defect centers in the as-implanted samples are the main

  15. Fractal characterization of the silicon surfaces produced by ion beam irradiation of varying fluences

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, R.P. [Department of Physics, University of Allahabad, Allahabad, UP 211002 (India); Kumar, T. [Department of Physics, Central University of Haryana, Jant-Pali, Mahendergarh, Haryana 123029 (India); Mittal, A.K. [Department of Physics, University of Allahabad, Allahabad, UP 211002 (India); K Banerjee Centre of Atmospheric and Ocean Studies, University of Allahabad, Allahabad, UP 211002 (India); Dwivedi, S., E-mail: suneetdwivedi@gmail.com [K Banerjee Centre of Atmospheric and Ocean Studies, University of Allahabad, Allahabad, UP 211002 (India); Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, PO Box 10502, New Delhi 110 067 (India)

    2015-08-30

    Highlights: • Fractal analysis of Si(1 0 0) surface morphology at varying ion fluences. • Autocorrelation function and height–height correlation function as fractal measures. • Surface roughness and lateral correlation length increases with ion fluence. • Ripple pattern of the surfaces is found at higher ion fluences. • Wavelength of the ripple surfaces is computed for each fluence. - Abstract: Si (1 0 0) is bombarded with 200 keV Ar{sup +} ion beam at oblique incidence with fluences ranging from 3 × 10{sup 17} ions/cm{sup 2} to 3 × 10{sup 18} ions/cm{sup 2}. The surface morphology of the irradiated surfaces is captured by the atomic force microscopy (AFM) for each ion fluence. The fractal analysis is performed on the AFM images. The autocorrelation function and height–height correlation function are used as fractal measures. It is found that the average roughness, interface width, lateral correlation length as well as roughness exponent increase with ions fluence. The analysis reveals the ripple pattern of the surfaces at higher fluences. The wavelength of the ripple surfaces is computed for each ion fluence.

  16. 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

  17. Time-domain vibrational study on defects in ion-irradiated crystal

    International Nuclear Information System (INIS)

    Kitajima, M.

    2003-01-01

    We have studied the effects of point defects on coherent phonons in ion-implanted bismuth and graphite. Ultrafast dynamics of coherent phonons and photo-generated carriers in the femtosecond time-domain have been investigated by means of pump-probe reflectivity measurements. Point defects are introduced by irradiating graphite with 5 keV He + ions. For Bi the dephasing rate of the A 1g phonon increases linearly with increasing ion dose, which is explained by the additional dephasing process of the coherent phonon originated from scattering of phonons by the defects. For graphite, introduction of the defects enhances the carrier relaxation by opening a decay channel via vacancy-states, which competes efficiently with carrier-phonon scattering. The coherent acoustic phonon relaxation is also accelerated due to an additional scattering by defects. The linear fluence-dependence of the decay rate is understood as scattering of propagating acoustic phonon by single vacancies. (author)

  18. Experimental study of interactions of highly charged ions with atoms at keV energies: Progress report for period May 15, 1985-February 15, 1987

    International Nuclear Information System (INIS)

    Kostroun, V.O.

    1987-01-01

    Interest in interactions of low energy highly charged ions with electrons, atoms or ions is due to their importance to controlled thermonuclear fusion research and the interesting nature of the fundamental processes involved. Studies of such interactions have long been hampered by a lack of suitable ions sources. A superconducting solenoid, cryogenic Electron Beam Ion Source, CEBIS, has been constructed at Cornell University to produce low energy very highly charged ions. At present, using a pulsed 0.5A,8.5 keV electron beam, the source is capable of producing highly charged ions of C,N,O, including bare nuclei, and ions of Ar up to charge state 11 + in 1 millisecond of confinement time. The source is being used in experiments to investigate charge transfer and accompanying processes in low energy, highly charged ion-atom collisions

  19. Cross sections for one-electron capture by highly stripped ions of Be, B and C from H2 and Ar below 10 keV

    International Nuclear Information System (INIS)

    Takagi, S.; Ohtani, S.; Kadota, K.; Fujita, J.

    1982-03-01

    Cross sections for one-electron capture by highly stripped ions of Be, B and C from H 2 and Ar are measured at low energies below 10 keV. The cross sections are nearly independent of the collision energy investigated. The distinct oscillation with incident ionic charge g in the cross sections are observed. (author)

  20. Influence of alloying elements on the dislocation loops created by Zr+ ion irradiation in alpha-zirconium

    International Nuclear Information System (INIS)

    Hellio, C.; Novion, C.H. de; Boulanger, L.

    1987-01-01

    Pure zirconium and four (annealed) α - zirconium based alloys (Zr-1760 ppm weight 0, Zr - 1% Nb - 430 ppm 0, Zr-1% Nb-1800 ppm 0, zircaloy 4) have been studied by transmission electron microscopy after 500 keV Zr + ion or 1 MeV electron irradiation performed at high temperature. Type of burgers vectors of the dislocation loops are given; in the case of electron irradiated Zr-1760 ppm 0, the larger loops were found of interstitial type. Alloying elements increase the loop density. The kinetic of loop growth was observed in-situ during 1 MeV electron irradiation between 400 and 700 0 C: oxygen was found to reduce considerably the growth speed of loops. In-situ annealing at 450 or 500 0 C after ion irradiation led to a large coalescence of loops in the case of pure zirconium, but modified only slightly the defect structure of the alloys

  1. Mechanical characterization of magnesium aluminate MgO·nAl2O3 spinel single crystals irradiated with Cu- ions

    International Nuclear Information System (INIS)

    Ohmura, Takahito; Lee, Chi-Gyu; Kishimoto, Naoki

    2003-01-01

    Ion-irradiation response of spinel single crystals was investigated using a nanoindentation technique. Specimens of stoichiometric (n=1) and non-stoichiometric (n=2.4) single crystals of MgO n(Al 2 O 3 ) spinel were irradiated with 60 keV Cu - ion at room temperature. Dose rate ranged from 1 to 100 μA/cm 2 , and a total dose was kept constant at 3x10 16 ions/cm 2 . Both plastic hardness and elastic modulus of all the irradiated specimens were softened. Radiation-induced swelling simultaneously occurred. Rutherford back scattering spectroscopy detected disordering of spinel crystalline structure. Accordingly, the radiation-induced softening and swelling are ascribed to accumulation of point defects associated with the disordering. In comparison between the stoichiometric and the non-stoichiometric specimens, the radiation-induced softening is suppressed in the non-stoichiometric composition. (author)

  2. Effects of Prenatal Irradiation with an Accelerated Heavy-Ion Beam on Postnatal Development in Rats

    Science.gov (United States)

    Wang, B.; Murakami, M.; Eguchi-Kasai, K.; Nojima, K.; Shang, Y.; Tanaka, K.; Fujita, K.; Coffigny, H.; Hayata, I.

    Effects on postnatal neurophysiological development in offspring were studied following exposure of pregnant Wistar rats to accelerated neon-ion beams with a LET value of about 30 keV mu m at a dose range from 0 1 Gy to 2 0Gy on the 15th day of gestation The age at which four physiologic markers appeared and five reflexes were acquired was examined prior to weaning Gain in body weight was monitored until the offspring were 3 months old Male offspring were evaluated as young adults using two behavioral tests The effects of X-rays at 200 kVp measured for the same biological end points were studied for comparison Our previous study on carbon-ion beams with a LET value of about 13 keV mu m was also cited to elucidate a possible LET-related effect For most of the endpoints at early age significant alteration was even observed in offspring prenatally received 0 1 Gy of accelerated neon ions while neither X rays nor carbon-ions under the same dose resulted in such a significant alteration compared to that from the sham-irradiated dams All offspring whose mothers received 2 0 Gy died prior to weaning Offspring from dams irradiated with accelerated neon ions generally showed higher incidences of prenatal death and preweaning mortality markedly delayed accomplishment in their physiological markers and reflexes and gain in body weight compared to those exposed to X-rays or carbon ions at doses of 0 1 to 1 5 Gy Significantly reduced ratios of main organ weight to body weight at postnatal ages of 30 60 and 90 days were also observed

  3. Irradiation influence on Mylar and Makrofol induced by argon ions in a plasma immersion ion implantation system

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, A. [Accelerators & Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.O. 13759, Cairo (Egypt); El-Saftawy, A.A., E-mail: aama1978@yahoo.com [Accelerators & Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.O. 13759, Cairo (Egypt); Aal, S.A. Abd El [Central Lab. for Elemental & Isotopic Analysis, Nuclear Research Center, Atomic Energy Authority, P.O. 13759, Cairo (Egypt); Ghazaly, M. El [Physiology Department, College of Medicine, Taif University, P.O. 888, Taif (Saudi Arabia); Physics Department, Faculty of Science, Zagazig University, P.O. 44519, Zagazig (Egypt)

    2015-08-30

    Highlights: • A home-built plasma immersion ion implantation system was tested in modifying surfaces. • Wettability modifications within the energy range 10 keV implantation are not investigated elsewhere, up to our knowledge. • The wettability of Mylar and Makrofol surface was enhanced by the dual effect of ion implantation and plasma treatment. • The improved wettability was found to depend on both surface roughness and chemistry. • The adhesive bonding and surface energy of the polymers are improved. - Abstract: Mylar and Makrofol polycarbonate polymers were irradiated by Ar ions in a plasma immersion ion implantation (PIII) system. The surface wettability of both polymers was investigated by employing the contact angle method. The measured contact angles were found to depend on the surface layer properties. Good wetting surfaces were found to depend not only on surface roughness but also on its chemistry that analyzed by Fourier transform infrared (FTIR) spectroscopy. Surfaces topography and roughness was investigated and correlated to their surface energy which studied with the aid of acid-base model for evaluating the improvement of surface wettability after irradiation. PIII improves polymers surface properties efficiently in a controllable way.

  4. Fe+ ion irradiation induced changes in structural and magnetic properties of iron films

    Directory of Open Access Journals (Sweden)

    K. Papamihail

    2016-12-01

    Full Text Available 490keV Fe+ ion irradiation of 200nm thick Fe films was found to induce both structural and magnetic changes. Both, the lattice constant and the grain size increase as a function of dose and both properties follow the same power law. Irradiation induces a depth dependent magnetic profile consisting of two sublayers. The top Fe sublayer has a magnetic moment higher than that of the Fe before the irradiation whereas the bottom sublayer lower. The two sublayers are connected with the effects of Fe+ irradiation, i.e. the top sublayer with the depth in which mainly radiation damage occurs whereas the bottom one with the implantation of impinging Fe+ ions. The magnetic moments of the two sublayers have a non-monotonous variation with irradiation dose depicting a maximum for the top sublayer and a minimum for the bottom one at 96.2 dpa (‘displacements per atom’. The magnetic moment enhancement/reduction is discussed in relation with the atomic volume variation in the case of atom displacements and/or implantation effects.

  5. Effect of He+ fluence on surface morphology and ion-irradiation induced defect evolution in 7075 aluminum alloys

    Science.gov (United States)

    Ni, Kai; Ma, Qian; Wan, Hao; Yang, Bin; Ge, Junjie; Zhang, Lingyu; Si, Naichao

    2018-02-01

    The evolution of microstructure for 7075 aluminum alloys with 50 Kev helium ions irradiation were studied by using optical microscopy (OM), scanning electron microscopy (SEM), x-ray diffraction (XRD) and transmission electron microscopy (TEM). The fluences of 1 × 1015, 1 × 1016 and 1 × 1017 ions cm-2 were selected, and irradiation experiments were conducted at room temperatures. The transmission process of He+ ions was simulated by using SRIM software, including distribution of ion ranges, energy losses and atomic displacements. Experimental results show that irradiated pits and micro-cracks were observed on irradiation sample surface, and the size of constituent particles (not including Mg2Si) decreased with the increasing dose. The x-ray diffraction results of the pair of peaks is better resolved in irradiated samples might indicate that the stressed structure consequence due to crystal defects (vacancies and interstitials) after He+ implantation. TEM observation indicated that the density of MgZn2 phase was significantly reduced after helium ion irradiation which is harmful to strength. Besides, the development of compressive stress produced a large amount of dislocation defects in the 1015 ions cm-2 sample. Moreover, higher fluence irradiation produced more dislocations in sample. At fluence of 1016 ions cm-2, dislocation wall formed by dislocation slip and aggregation in the interior of grains, leading to the refinement of these grains. As fluence increased to 1017 ions cm-2, dislocation loops were observed in pinned dislocation. Moreover, dislocation as effective defect sink, irradiation-induced vacancy defects aggregated to these sinks, and resulted in the formation of helium bubbles in dislocation.

  6. Effects of ion irradiation on the mechanical properties of SiNa wO xC yH z sol-gel derived thin films

    Science.gov (United States)

    Lucca, D. A.; Qi, Y.; Harriman, T. A.; Prenzel, T.; Wang, Y. Q.; Nastasi, M.; Dong, J.; Mehner, A.

    2010-10-01

    A study of the effects of ion irradiation of hybrid organic/inorganic modified silicate thin films on their mechanical properties is presented. NaOH catalyzed SiNa wO xC yH z thin films were synthesized by sol-gel processing from tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) precursors and spin-coated onto Si substrates. After drying at 300 °C, the films were irradiated with 125 keV H + or 250 keV N 2+ at fluences ranging from 1 × 10 14 to 2.5 × 10 16 ions/cm 2. Nanoindentation was used to characterize the films. Changes in hardness and reduced elastic modulus were examined as a function of ion fluence and irradiating species. The resulting increases in hardness and reduced elastic modulus are compared to similarly processed acid catalyzed silicate thin films.

  7. Effects of ion irradiation on the mechanical properties of SiNawOxCyHz sol-gel derived thin films

    International Nuclear Information System (INIS)

    Lucca, D.A.; Qi, Y.; Harriman, T.A.; Prenzel, T.; Wang, Y.Q.; Nastasi, M.; Dong, J.; Mehner, A.

    2010-01-01

    A study of the effects of ion irradiation of hybrid organic/inorganic modified silicate thin films on their mechanical properties is presented. NaOH catalyzed SiNa w O x C y H z thin films were synthesized by sol-gel processing from tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) precursors and spin-coated onto Si substrates. After drying at 300 o C, the films were irradiated with 125 keV H + or 250 keV N 2+ at fluences ranging from 1 x 10 14 to 2.5 x 10 16 ions/cm 2 . Nanoindentation was used to characterize the films. Changes in hardness and reduced elastic modulus were examined as a function of ion fluence and irradiating species. The resulting increases in hardness and reduced elastic modulus are compared to similarly processed acid catalyzed silicate thin films.

  8. Sex- and dose-dependent effects of calcium ion irradiation on behavioral performance of B6D2F1 mice during contextual fear conditioning training

    Science.gov (United States)

    Raber, Jacob; Weber, Sydney J.; Kronenberg, Amy; Turker, Mitchell S.

    2016-06-01

    The space radiation environment includes energetic charged particles that may impact behavioral and cognitive performance. The relationship between the dose and the ionization density of the various types of charged particles (expressed as linear energy transfer or LET), and cognitive performance is complex. In our earlier work, whole body exposure to 28Si ions (263 MeV/n, LET = 78keV / μ m ; 1.6 Gy) affected contextual fear memory in C57BL/6J × DBA2/J F1 (B6D2F1) mice three months following irradiation but this was not the case following exposure to 48Ti ions (1 GeV/n, LET = 107keV / μ m ; 0.2 or 0.4 Gy). As an increased understanding of the impact of charged particle exposures is critical for assessment of risk to the CNS of astronauts during and following missions, in this study we used 40Ca ion beams (942 MeV/n, LET = 90keV / μm) to determine the behavioral and cognitive effects for the LET region between that of Si ions and Ti ions. 40Ca ion exposure reduced baseline activity in a novel environment in a dose-dependent manner, which suggests reduced motivation to explore and/or a diminished level of curiosity in a novel environment. In addition, exposure to 40Ca ions had sex-dependent effects on response to shock. 40Ca ion irradiation reduced the response to shock in female, but not male, mice. In contrast, 40Ca ion irradiation did not affect fear learning, memory, or extinction of fear memory for either gender at the doses employed in this study. Thus 40Ca ion irradiation affected behavioral, but not cognitive, performance. The effects of 40Ca ion irradiation on behavioral performance are relevant, as a combination of novelty and aversive environmental stimuli is pertinent to conditions experienced by astronauts during and following space missions.

  9. 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.

  10. 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)

  11. 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.

  12. Angular scattering of 1–50 keV ions through graphene and thin carbon foils: Potential applications for space plasma instrumentation

    International Nuclear Information System (INIS)

    Ebert, Robert W.; Allegrini, Frédéric; Fuselier, Stephen A.; Nicolaou, Georgios; Bedworth, Peter; Sinton, Steve; Trattner, Karlheinz J.

    2014-01-01

    We present experimental results for the angular scattering of ∼1–50 keV H, He, C, O, N, Ne, and Ar ions transiting through graphene foils and compare them with scattering through nominal ∼0.5 μg cm −2 carbon foils. Thin carbon foils play a critical role in time-of-flight ion mass spectrometers and energetic neutral atom sensors in space. These instruments take advantage of the charge exchange and secondary electron emission produced as ions or neutral atoms transit these foils. This interaction also produces angular scattering and energy straggling for the incident ion or neutral atom that acts to decrease the performance of a given instrument. Our results show that the angular scattering of ions through graphene is less pronounced than through the state-of-the-art 0.5 μg cm −2 carbon foils used in space-based particle detectors. At energies less than 50 keV, the scattering angle half width at half maximum, ψ 1/2 , for ∼3–5 atoms thick graphene is up to a factor of 3.5 smaller than for 0.5 μg cm −2 (∼20 atoms thick) carbon foils. Thus, graphene foils have the potential to improve the performance of space-based plasma instruments for energies below ∼50 keV

  13. The effect of ion irradiation and elevated temperature on the microstructure and the properties of C/W/C/B multilayer coating

    Energy Technology Data Exchange (ETDEWEB)

    Vlcak, Petr, E-mail: petr.vlcak@fs.cvut.cz

    2016-03-01

    Graphical abstract: - Highlights: • C/W/C/B multilayer PVD coating was treated by 45 keV nitrogen ion irradiation. • The effect of ion irradiation and elevated temperature on microstructure was analyzed. • Formation of new compounds and degradation of carbon fraction were observed. • The causes of the observed changes in surface properties were discussed. - Abstract: C/W/C/B multi-layer PVD coating with a layer period of 10 nm and 500 nm in thickness was irradiated with 45 keV N ions at fluence of 1 × 10{sup 17} cm{sup −2}. Ion irradiation was performed at room temperature or at an elevated temperature of 500 °C. The microstructure was investigated by X-ray diffraction, by X-ray photoelectron spectroscopy, and by Raman spectroscopy. The results showed that implanted N ions bond both with W atoms and with C atoms. N ion irradiation induced the formation of WC and WC{sub 1−x} phases. The energetic ions transformed the C bonds in defect sp{sup 2} and defect sp{sup 3} hybridizations, resulting in graphitization of the carbon fraction in the multilayer coating. Ion irradiation reduced the cohesive strength of the monolayers, reduced hardness of the C/W/C/B coating, increased its surface roughness and increased its friction coefficient. An elevated temperature during ion irradiation caused a better arrangement of the WC phase and further graphitization of the carbon fraction, in comparison with a coating treated by ion irradiation at room temperature. There is discussion of the causes of the observed changes in surface properties.

  14. Effect of solute elements in Ni alloys on blistering under He + and D + ion irradiation

    Science.gov (United States)

    Wakai, E.; Ezawa, T.; Takenaka, T.; Imamura, J.; Tanabe, T.; Oshima, R.

    2007-08-01

    Effects of solute atoms on microstructural evolution and blister formation have been investigated using Ni alloys under 25 keV He + and 20 keV D + irradiation at 500 °C to a dose of about 4 × 10 21 ions/m 2. The specimens used were pure Ni, Ni-Si, Ni-Co, Ni-Cu, Ni-Mn and Ni-Pd alloys. The volume size factors of solute elements for the Ni alloys range from -5.8% to +63.6%. The formations of blisters were observed in the helium-irradiated specimens, but not in the deuteron-irradiated specimens. The areal number densities of blisters increased with volume size difference of solute atoms. The dependence of volume size on the areal number densities of blisters was very similar to that of the number densities of bubbles on solute atoms. The size of the blisters inversely decreased with increasing size of solute atoms. The formation of blisters was intimately related to the bubble growth, and the gas pressure model for the formation of blisters was supported by this study.

  15. Evidence of blocking effects on 3-keV Ne7+ ions guided through nanocapillaries in polycarbonate

    International Nuclear Information System (INIS)

    Stolterfoht, N.; Hellhammer, R.; Sulik, B.; Juhasz, Z.; Bayer, V.; Trautmann, C.; Bodewits, E.; Hoekstra, R.

    2011-01-01

    We studied the dynamic properties of ion guiding through nanocapillaries etched in insulating polycarbonate (PC). Capillaries with diameters of 95 and 165 nm and a length of 10 μm were used. In a further sample, the capillaries had a diameter of 175 nm and a length of 30 μm. A few additional measurements were made using capillaries in polyethylene terephthalate (PET). The temporal evolution of the intensity and the angular distribution of the transmitted ions were studied by measuring transmission profiles as a function of the charge deposited on the sample surface. The tilt angle of the capillary axis was varied from 0 deg. to 5 deg. The mean emission angle of the transmission profiles exhibit pronounced oscillations, similarly as in previous measurements using PET. However, for PC, nearly an order of magnitude more charge needs to be inserted into the capillaries to accomplish the oscillations. In contrast to PET, with PC, we observed a strong decrease of the profile intensities with irradiation time. This observation provides evidence of blocking effects on the ions, which are likely to be due to a repulsive field produced by significant charge deposition inside the PC capillaries.

  16. 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.

  17. 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.

  18. 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 ...

  19. Irradiation Effect of Argon Ion on Interfacial Structure Fe(2nm/Si(tsi=0.5-2 nm Multilayer thin Film

    Directory of Open Access Journals (Sweden)

    S. Purwanto

    2010-04-01

    Full Text Available Investigation includes formation of interfacial structure of Fe(2nm/Si(tSi= 0.5-2 nm multilayer thin film and the behavior of antiferromagnetic coupling between Fe layers due to Argon ion irradiation was investigated. [Fe(2nm/Si]30 multilayers (MLs with a thickness of Si spacer 0.5 - 2 nanometer were prepared on n-type (100 Si substrate by the helicon plasma sputtering method. Irradiation were performed using 400keV Ar ion to investigate the behavior of magnetic properties of the Fe/Si MLs. The magnetization measurements of Fe/Si MLs after 400keV Ar ion irradiation show the degradation of antiferromagnetic behavior of Fe layers depend on the ion doses. The Magnetoresistance (MR measurements using by Four Point Probe (FPP method also confirm that MR ratio decrease after ion irradiation. X-ray diffraction (XRD patterns indicate that the intensity of a satellite peak induced by a superlattice structure does not change within the range of ion dose. These results imply that the surface of interface structures after ion irradiation become rough although the layer structures are maintained. Therefore, it is considered that the MR properties of Fe/Si MLs also are due to the metallic superlattice structures such as Fe/Cr and Co/Cu MLs.

  20. 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

  1. 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

  2. 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.

  3. A Monte Carlo computer code for evaluating energy loss of 10 keV to 10 MeV ions in amorphous silicon materials

    International Nuclear Information System (INIS)

    Erramli, H.; Elbounagui, O.; Misdaq, M.A.; Merzouki, A.

    2007-01-01

    The basic concepts of a computer simulation code for determining the energy loss of ions in the 10 keV to 10 MeV energy range in amorphous silicon materials were presented and discussed. Data obtained were found in good agreement with those obtained by using a SRIM programme. Electronic and nuclear energy losses were evaluated. Variation of the energy loss as a function of the incident ion energy were studied. This new computer code is a good tool for evaluating stopping powers of various materials for light and heavy ions

  4. Origin of Si(LMM) Auger Electron Emission from Silicon and Si-Alloys by keV Ar+ Ion Bombardment

    Science.gov (United States)

    Iwami, Motohiro; Kim, Su Chol; Kataoka, Yoshihide; Imura, Takeshi; Hiraki, Akio; Fujimoto, Fuminori

    1980-09-01

    Si(LMM) Auger electrons emitted from specimens of pure silicon and several Si-alloys (Ni-Si, Pd-Si and Cu-Si) under keV Ar+ ion bombardment, were examined. In the Auger spectra from all specimens studied there were four peaks at energies of 92, 86, 76 and 66 eV. The Auger signal intensity varied considerably with both the incident angle and the energy of the primary ion beam. It is proposed that the Auger electrons are emitted from silicon atoms (or ions) just beneath the specimen surface but free from the bulk network.

  5. Origin of Si(LMM) Auger electron emission from silicon and Si-alloys by keV Ar/sup +/ ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Iwami, M; Kim, S; Kataoka, Y; Imura, T; Hiraki, A [Osaka Univ., Suita (Japan). Faculty of Engineering

    1980-09-01

    Si(LMM) Auger electrons emitted from specimens of pure silicon and several Si-alloys (Ni-Si, Pd-Si and Cu-Si) under keV Ar/sup +/ ion bombardment, were examined. In the Auger spectra from all specimens studied there were four peaks at energies of 92, 86, 76 and 66 eV. The Auger signal intensity varied considerably with both the incident angle and the energy of the primary ion beam. It is proposed that the Auger electrons are emitted from silicon atoms (or ions) just beneath the specimen surface but free from the bulk network.

  6. 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

  7. 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

  8. 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

  9. Effects of low temperature periodic annealing on the deep-level defects in 200 keV proton irradiated AlGaAs-GaAs solar cells

    Science.gov (United States)

    Li, S. S.; Chiu, T. T.; Loo, R. Y.

    1981-01-01

    The GaAs solar cell has shown good potential for space applications. However, degradation in performance occurred when the cells were irradiated by high energy electrons and protons in the space environment. The considered investigation is concerned with the effect of periodic thermal annealing on the deep-level defects induced by the 200 keV protons in the AlGaAs-GaAs solar cells. Protons at a fluence of 10 to the 11th P/sq cm were used in the irradiation cycle, while annealing temperatures of 200 C (for 24 hours), 300 C (six hours), and 400 C (six hours) were employed. The most likely candidate for the E(c) -0.71 eV electron trap observed in the 200 keV proton irradiated samples may be due to GaAs antisite, while the observed E(v) +0.18 eV hole trap has been attributed to the gallium vacancy related defect. The obtained results show that periodic annealing in the considered case does not offer any advantages over the one time annealing process.

  10. Direct observation of cascade defect formation at low temperatures in ion-irradiated metals

    International Nuclear Information System (INIS)

    Muroga, T.; Hirooka, K.; Ishino, S.

    1984-01-01

    Direct transmission electron microscopy observations of cascade defect formation have been carried out in gold, Type 316 stainless steel, and aluminum irradiated by Al + , Ar - , and Xe + ions with energies between 80 and 400 keV. By utilizing a link of an ion accelerator to an electron microscope, in situ observations at low temperature (-150 0 C) have become possible. In gold, subcascade structures are clearly observed in all cases. Obvious dependence on projectile mass and energy is observed for cascade structure and vacancy clustering efficiency in gold and for defect visibility in aluminum and Type 316 stainless steel. A computer simulation calculation using MARLOWE shows subcascade distributions a little smaller in size and larger in number than the present observation

  11. The accumulation of disorder, subject to saturation and sputter limitation, in ion irradiated solids

    International Nuclear Information System (INIS)

    Carter, G.; Webb, R.; Collins, R.

    1978-01-01

    The depth distribution of disorder and the depth integrated disorder produced by ion irradiation of solids is analysed theoretically as a function of increasing ion fluence when disorder saturation processes operate at all depths and the solid surface is continuously uniformly eroded by sputtering. The resulting defining equations are evaluated numerically for a Gaussian approximation to the disorder depth function with parameters appropriate to low, equal and high projectile:substrate mass ratio conditions, for several values of sputtering coefficient and effective atom displacement energy. It is shown that the form, if not the magnitude, of the integrated disorder/projectile fluence function is only weakly dependent upon these parameters. More meaningful comparison with depth resolved disorder functions is, however, possible and such a comparison is made for 100 keV Sb projectiles on a Si substrate. (author)

  12. Grafting of acrylic acid onto polypropylene films irradiated with argon ions

    International Nuclear Information System (INIS)

    Massa, G.; Mazzei, R.; Garcia Bermudez, G.; Filevich, A.; Smolko, E.

    2005-01-01

    Polypropylene (PP) foils were irradiated with 100 keV energy Argon ions at different fluences ranging from 10 12 up to 2 x 10 15 cm -2 and then grafted with acrylic acid (AA). The grafting yield was measured by weight difference and the structural changes on the films were analysed using Fourier transform infrared spectroscopy (FTIR). Different parameters that determined the grafting process such us fluence, grafting time and monomer concentration were analysed. The grafting reached an optimum value at 79% in aqueous solution at 30 min grafting time. The grafting yield as a function of the ion fluence plot, presented a maximum value, as previously found in a study of heavy beam on polymers

  13. Energy loss and straggling of 1–50 keV H, He, C, N, and O ions passing through few layer graphene

    International Nuclear Information System (INIS)

    Allegrini, Frédéric; Bedworth, Peter; Ebert, Robert W.; Fuselier, Stephen A.; Nicolaou, Georgios; Sinton, Steve

    2015-01-01

    Highlights: • Evaluation of graphene foils for space plasma instruments. • Energy loss and straggling of keV ions passing through graphene foils. • Lower energy loss than for ultra-thin carbon foils. • Thickness non-uniformity leads to higher straggling. - Abstract: Graphene could be an alternative to amorphous carbon foils, in particular in space plasma instrumentation. The interaction of ions or neutral atoms with these foils results in different effects: electron emission, charge exchange, angular scattering, and energy straggling. We showed in previous studies that (1) the charge exchange properties are similar for graphene and regular carbon foils, and (2) the scattering at low energies (few keVs) is less for graphene than for one of our thinnest practical carbon foils. In this study, we report measurements of the energy loss and straggling of ∼1–50 keV H, He, C, N, and O ions in graphene. We compare graphene and a carbon foil for hydrogen. We provide simple power law fits to the average energy loss, energy straggling, and skewness of the energy distributions. We find the energy loss for ions transiting through graphene to be reduced compared to thin carbon foils but the energy straggling to be larger, which we attribute to the non-uniformity of the graphene foils used in this study

  14. Comparison of the Raman spectra of ion irradiated soot and collected extraterrestrial carbon

    Science.gov (United States)

    Brunetto, R.; Pino, T.; Dartois, E.; Cao, A.-T.; d'Hendecourt, L.; Strazzulla, G.; Bréchignac, Ph.

    2009-03-01

    We use a low pressure flame to produce soot by-products as possible analogues of the carbonaceous dust present in diverse astrophysical environments, such as circumstellar shells, diffuse interstellar medium, planetary disks, as well as in our own Solar System. Several soot samples, displaying an initial chemical diversity from aromatic to aliphatic dominated material, are irradiated with 200-400 keV H +, He +, and Ar ++ ions, with fluences comprised between 10 14 and 10 16 ions/cm 2, to simulate expected radiation induced modification on extraterrestrial carbon. The evolution of the samples is monitored using Raman spectroscopy, before, during, and after irradiation. A detailed analysis of the first- and second-order Raman spectra is performed, using a fitting combination of Lorentzian and/or Gaussian-shaped bands. Upon irradiation, the samples evolve toward an amorphous carbon phase. The results suggest that the observed variations are more related to vacancy formation than ionization processes. A comparison with Raman spectra of extraterrestrial organic matter and other irradiation experiments of astrophysically relevant carbonaceous materials is presented. The results are consistent with previous experiments showing mostly amorphization of various carbonaceous materials. Irradiated soots have Raman spectra similar to those of some meteorites, IDPs, and Comet Wild 2 grains collected by the Stardust mission. Since the early-Sun expected irradiation fluxes sufficient for amorphization are compatible with accretion timescales, our results support the idea that insoluble organic matter (IOM) observed in primitive meteorites has experienced irradiation-induced amorphization prior to the accretion of the parent bodies, emphasizing the important role played by early solar nebula processing.

  15. Post-annealing effects on shallow-junction characteristics caused by 20 keV BGe molecular ion implantation

    International Nuclear Information System (INIS)

    Liang, J.H.; Sang, Y.J.; Wang, C.-H.; Wang, T.W.; Hsu, J.Y.; Niu, H.; Tseng, M.S.

    2005-01-01

    This study examines the post-annealing-dependent behaviors of the shallow junction produced by implanting 10 15 cm -2 20 keV BGe ions into n-type silicon specimens. Post-annealing treatments consisted of one- and two-step annealing including both furnace annealing (FA) and rapid thermal annealing (RTA). Comparison of the one-step FA at 550 deg. C and the one-step RTA at 1050 deg. C revealed that boron depth profiles were slightly diffused in the former but exhibited considerable transient-enhanced diffusion (TED) in the latter. However, both the one-step FA- and RTA-annealed germanium depth profiles barely diffused, while the latter diffusing slightly deeper than the former. The optimum value of junction depth (x j ) times sheet resistance (R s ) was obtained with one-step FA at 550 deg. C for 1 h. The two-step annealing (FA at 550 deg. C and RTA at 1050 deg. C) results showed that the RTA-induced TED in the boron depth profiles could be effectively retarded only when FA took place for more than 3 h. Again, germanium depth profiles are also barely diffused while the corresponding TEDs were larger than those in one-step FA but smaller than those in one-step RTA. Furthermore, the two-step annealing of FA at 550 deg. C for 3 h followed by RTA at 1050 deg. C for 30 s is suggested when attempting to obtain an optimum value of x j R s

  16. 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.

  17. 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

  18. Effects of tube diameter and chirality on the stability of single-walled carbon nanotubes under ion irradiation

    International Nuclear Information System (INIS)

    Xu Zijian; Zhang Wei; Zhu Zhiyuan; Ren Cuilan; Li Yong; Huai Ping

    2009-01-01

    Using molecular dynamics method, we investigated the influence of tube diameter and chirality on the stability of single-walled carbon nanotubes (CNTs) under ion irradiation. We found that in the energy range below 1 keV, the dependence of CNT stability on the tube diameter is no longer monotonic under C ion irradiation, and the thinner (5, 5) CNT may be more stable than the thicker (7, 7) CNT, while under Ar irradiation, the CNT stability increases still monotonically with the CNT diameter. This stability behavior was further verified by the calculations of the threshold ion energies to produce displacement damage in CNTs. The abnormal stability of thin CNTs is related to their resistance to the instantaneous deformation in the wall induced by ion pushing, the high self-healing capacity, as well as the different interaction properties of C and Ar ions with CNT atoms. We also found that under ion irradiation the stability of a zigzag CNT is better than that of an armchair CNT with the same diameter. This is because of the bonding structure difference between the armchair and the zigzag CNTs with respect to the orientations of graphitic networks as well as the self-healing capacity difference.

  19. Tunable electronic, electrical and optical properties of graphene oxide sheets by ion irradiation

    Science.gov (United States)

    Jayalakshmi, G.; Saravanan, K.; Panigrahi, B. K.; Sundaravel, B.; Gupta, Mukul

    2018-05-01

    The tunable electronic, electrical and optical properties of graphene oxide (GO) sheets were investigated using a controlled reduction by 500 keV Ar+-ion irradiation. The carbon to oxygen ratio of the GO sheets upon the ion beam reduction has been estimated using resonant Rutherford backscattering spectrometry analyses and its effect on the electrical and optical properties of GO sheets has been studied using sheet resistance measurements and photoluminescence (PL) measurements. The restoration of sp 2-hybridized carbon atoms within the sp 3 matrix is found to be increases with increasing the Ar+-ion fluences as evident from Fourier transform infrared, and x-ray absorption near-edge structure measurements. The decrease in the number of disorder-induced local density of states (LDOSs) within the π-π* gap upon the reduction causes the shifting of PL emission from near infra-red to blue region and decreases the sheet resistance. The improved electrical and optical properties of GO sheets were correlated to the decrease in the number of LDOSs within the π-π* gap. Our experimental investigations suggest ion beam irradiation is one of an effective approaches to reduce GO to RGO and to tailor its electronic, electrical and optical properties.

  20. Optical properties of Ar ions irradiated nanocrystalline ZrC and ZrN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Martin, C. [Ramapo College of New Jersey, Mahwah, NJ 07430 (United States); Miller, K.H. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Makino, H. [Research Institute, Kochi University of Technology, Kami, Kochi, 782-8502 (Japan); Craciun, D. [National Institute for Laser, Plasma, and Radiation Physics, Bucharest-Magurele (Romania); Simeone, D. [CEA/DEN/DANS/DM2S/SERMA/LEPP-LRC CARMEN CEN Saclay France & CNRS/ SPMS UMR8785 LRC CARMEN, Ecole Centrale de Paris, F92292, Chatenay Malabry (United States); Craciun, V., E-mail: valentin.craciun@inflpr.ro [National Institute for Laser, Plasma, and Radiation Physics, Bucharest-Magurele (Romania)

    2017-05-15

    Employing wide spectral range (0.06–6 eV) optical reflectance measurements and high energy X-ray photoemission spectroscopy (HE-XPS), we studied the effect of 800 keV Ar ion irradiation on optical and electronic properties of nanocrystalline ZrC and ZrN thin films, which were obtain by the pulsed laser deposition technique. Both in ZrC and ZrN, we observed that irradiation affects the optical properties of the films mostly at low frequencies, which is dominated by the free carriers response. In both materials, we found a significant reduction in the free carriers scattering rate and an increase of the zero frequency conductivity, i.e. possible increase in mobility, at higher irradiation fluence. This is consistent with our previous findings that irradiation affects the crystallite size and the micro-strain, but it does not induce major changes in the chemical bonding. HE-XPS investigations further confirms the stability of the Zr-C and Zr-N bonds, despite a small increase in the surface region of the Zr-O bonds fraction with increasing irradiation fluence.

  1. 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

  2. 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)

  3. Sputtering of copper atoms by keV atomic and molecular ions A comparison of experiment with analytical and computer based models

    CERN Document Server

    Gillen, D R; Goelich,

    2002-01-01

    Non-resonant multiphoton ionisation combined with quadrupole and time-of-flight analysis has been used to measure energy distributions of sputtered copper atoms. The sputtering of a polycrystalline copper target by 3.6 keV Ar sup + , N sup + and CF sub 2 sup + and 1.8 keV N sup + and CF sub 2 sup + ion bombardment at 45 deg. has been investigated. The linear collision model in the isotropic limit fails to describe the high energy tail of the energy distributions. However the TRIM.SP computer simulation has been shown to provide a good description. The results indicate that an accurate description of sputtering by low energy, molecular ions requires the use of computer simulation rather than analytical approaches. This is particularly important when considering plasma-surface interactions in plasma etching and deposition systems.

  4. A study of the effect of helium concentration and displacement damage on the microstructure of helium ion irradiated tungsten

    Science.gov (United States)

    Harrison, R. W.; Greaves, G.; Hinks, J. A.; Donnelly, S. E.

    2017-11-01

    Transmission electron microscopy (TEM) with in-situ He ion irradiation has been used to examine the damage microstructure of W when varying the helium concentration to displacement damage ratio, irradiation temperature and total dose. Irradiations employed 15, 60 or 85 keV He ions, at temperatures between 500 and 1000 °C up to doses of ∼3.0 DPA. Once nucleated and grown to an observable size in the TEM, bubble diameter as a function of irradiation dose did not measurably increase at irradiation temperatures of 500 °C between 1.0 and 3.0 DPA; this is attributed to the low mobility of vacancies and He/vacancy complexes at these temperatures. Bubble diameter increased slightly for irradiation temperatures of 750 °C and rapidly increased when irradiated at 1000 °C. Dislocation loops were observed at irradiation temperatures of 500 and 750 °C and no loops were observed at 1000 °C. Burgers vectors of the dislocations were determined to be b = ±½ type only and both vacancy and interstitial loops were observed. The proportion of interstitial loops increased with He-appm/DPA ratio and this is attributed to the concomitant increase in bubble areal density, which reduces the vacancy flux for both the growth of vacancy-type loops and the annihilation of interstitial clusters.

  5. Experimental study of interactions of highly charged ions with atoms at keV energies: Progress report, February 16, 1987-January 15, 1988

    International Nuclear Information System (INIS)

    Kostroun, V.O.

    1988-01-01

    This report describes the progress made during the past year towards the understanding of the behavior of electron beam ion sources and using the sources constructed in this laboratory to investigate interactions of highly charged ions with atoms at keV energies. The operational status of the two sources in use, CEBIS I and CEBIS II is described. At present, the sources are producing beams of bare, hydrogen and helium like ions of C, N, and O, and argon ions up to Ar 13+ with peak current pulses in the electric nanoampere range. Some of the problems encountered in the development of the sources and their resolution are discussed, and a brief description of experimental apparatus and ion beam transport line is presented. Experiments in progress are described

  6. Heavy and light ion irradiation damage effects in δ-phase Sc{sub 4}Hf{sub 3}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Wen, J. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu 730000 (China); Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Li, Y.H., E-mail: liyuhong@lzu.edu.cn [School of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu 730000 (China); Tang, M.; Valdez, J.A.; Wang, Y.Q. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Patel, M.K.; Sickafus, K.E. [Department of Materials Science & Engineering, The University of Tennessee, Knoxville, TN 37996 (United States)

    2015-12-15

    Polycrystalline δ-phase Sc{sub 4}Hf{sub 3}O{sub 12} was irradiated with light and heavy ions to study the radiation stability of this compound. In order to explore the ion species spectrum effect, the irradiations were performed with 400 keV Ne{sup 2+} ions to fluences ranging from 1 × 10{sup 14} to 1 × 10{sup 15} ions/cm{sup 2}, 600 keV Kr{sup 3+} ions to fluences ranging from 5 × 10{sup 14} to 5 × 10{sup 15} ions/cm{sup 2}, and 6 MeV Xe{sup 26+} ions to fluences ranging from 2 × 10{sup 13} to 1 × 10{sup 15} ions/cm{sup 2}. Irradiated samples were characterized by various techniques including grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM). A complete phase transformation from ordered rhombohedral to disordered fluorite was observed by a fluence of 1 × 10{sup 15} ions/cm{sup 2} with 400 keV Ne{sup 2+} ions, equivalent to a peak ballistic damage dose of ∼0.33 displacements per atom (dpa). Meanwhile, the same transformation was also observed by 600 keV Kr{sup 3+} ions at the same fluence of 1 × 10{sup 15} ions/cm{sup 2}, which however corresponds to a peak ballistic damage dose of ∼2.2 dpa. Only a partial O-D transformation was observed for 6 MeV Xe{sup 26+} ions in the fluence range used. Experimental results indicated that the O-D transformation is observed under both electronic and nuclear stopping dominant irradiation regimes. It was also observed that light ions are more efficient than heavy ions in producing the retained defects that are presumably responsible for the O-D phase transformation. The O-D transformation mechanism is discussed in the context of anion oxygen Frenkel defects and cation antisite defects. We concluded that the irradiation induced O-D transformation is easier to occur in δ-phase compounds with partial order of cations than in that with fully disordered cation structures.

  7. 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

  8. Effect of 14N ion irradiation on Bi2Sr2CaCu2Oy superconductors

    International Nuclear Information System (INIS)

    Sharma, M.L.; Ashwini Kumar, P.K.; Sarkar, S.K.; Virdi, G.S.; Rup, R.

    1993-01-01

    The effect of 14 N ion irradiation on a bulk Bi 2 Sr 2 CaCu 2 O y high-T c superconducting system has been studied. The incident energy was kept at 150 keV and the irradiation dose varied between 1 x 10 11 cm -2 and 1 x 10 16 cm -2 . It has been observed that the resistive transition occurs at lower temperatures for the irradiated specimens and the width (10-90% transition) of the superconducting transition decreases. Scanning transmission electron microscopy and x-ray diffraction (XRD) studies were carried out to evaluate the change in surface microstructure and XRD peak intensities due to irradiation. The results are discussed in the light of the similarity of atomic sizes of N and O atoms. (author)

  9. Response times of Cassini/INCA > 5.2 keV ENAs and Voyager ions in the heliosheath over the solar cycle

    Science.gov (United States)

    Dialynas, K.; Krimigis, S. M.; Mitchell, D. G.; Decker, R. B.; Roelof, E. C.

    2017-09-01

    Both a magnetosphere-like tail and a bubble model of the heliosphere were posited by E. N. Parker in 1961. Recently, we showed that heliosheath ions are the source of > 5.2 keV Energetic Neutral Atoms (ENA), whose images of the heliosphere exhibit a rough nose to anti-nose (tail) global symmetry that resembles a diamagnetic bubble. The comparison between energetic neutral atom (ENA) global images of the helioshphere obtained with the Ion and Neutral Camera (INCA) on board Cassini and ions measured in-situ by the Low Energy Charged Particle experiment (LECP) on board Voyager 1 and 2 (V1/V2) in overlapping energy bands over an 11-year period shows that the heliosphere responds promptly, within ∼2-3 years, to outward propagating solar wind changes in both the nose and tail directions. Here we focus on the recovery of solar cycle 24 and the response times of > 5.2 keV ENAs to show that this ∼2-3-year time delay is consistent with a “tail” of ∼80-120 AU. This preliminary rough calculation is generally consistent with lower energy ENA data (E < 6 keV, from the IBEX-Lo and IBEX-Hi) and is supported by recent modelling of the heliosphere.

  10. 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.

  11. Ion induced modification of polymers at energies between 100 keV and 1 GeV applied for optical waveguides and improved metal adhesion

    International Nuclear Information System (INIS)

    Rueck, D.M.

    2000-01-01

    Polymers are a class of materials widely used for a broad field of applications. Ion irradiation ranging from several eV to GeV is a quite efficient tool to modify the properties of polymers like wettability, optical properties, adhesion between metal and polymer surfaces. In this paper ion induced chemical changes of polymers will be discussed in relation to the modified macroscopic properties. In the field of optical telecommunication, polymers are discussed as a new class of materials for the fabrication of passive optical devices. Ion irradiation is a promising method to generate structures with a modified index of refraction, which is necessary for the guidance of light with different wavelengths in optical devices. Modified optical properties of different polymers under ion irradiation will be discussed. Analytical investigations like infrared measurements and measurement of the outgassing reaction products during irradiation will be discussed to interpret the chemical changes of the polymers. Metallization of polymers is of interest in several fields of application like for multilayer systems in microtechnology or casings for radiation shielding for example. Ion beam mixing at low energies is a promising method to improve the metal/polymer adhesion. Also ion irradiation at high energies applied to a metal/polymer multilayer can improve the adhesion of a metal layer to a polymer surface, if not sufficient. Different metal/polymer systems will be presented as well as specific applications

  12. Preparation and Characterization of Ion-Irradiated Nanodiamonds as Photoacoustic Contrast Agents.

    Science.gov (United States)

    Fang, Chia-Yi; Chang, Cheng-Chun; Mou, Chung-Yuan; Chang, Huan-Cheng

    2015-02-01

    Highly radiation-damaged or irradiated nanodiamonds (INDs) are a new type of nanomaterial developed recently as a potential photoacoustic (PA) contrast agent for deep-tissue imaging. This work characterized in detail the photophysical properties of these materials prepared by ion irradiation of natural diamond powders using various spectroscopic methods. For 40-nm NDs irradiated with 40-keV He+ at a dose of 3 x 10(15) ions/cm2, an average molar extinction coefficient of 4.2 M-1 cm-1 per carbon atom was measured at 1064 nm. Compared with gold nanorods of similar dimensions (10 nm x 67 nm), the INDs have a substantially smaller (by > 4 orders of magnitude) molar extinction coefficient per particle. However, the deficit is readily compensated by the much higher thermal stability, stronger hydrophilic interaction with water, and a lower nanobubble formation threshold (~30 mJ/cm2) of the sp3-carbon-based nanomaterial. No sign of photodamage was detected after high-energy (>100 mJ/cm2) illumination of the INDs for hours. Cell viability assays at the IND concentration of up to 100 µg/mL showed that the nanomaterial is non-cytotoxic and potentially useful for long-term PA bioimaging applications.

  13. Correlation of blister diameter and blister skin thickness in helium-ion-irradiated Nb

    International Nuclear Information System (INIS)

    Das, S.K.; Kaminsky, M.; Fenske, G.

    1979-01-01

    A systematic study of the correlation between blister diameter and blister skin thickness has been performed for helium-ion irradiation of monocrystalline and polycrystalline Nb for ion energies ranging from 20 to 500 keV. The results indicate that a relationship Datsub mpatproportionaltatsup 1.50at between the most probable blister diameter, Datsub mpat, and blister skin thickness, t, which has been suggested by other authors, does not exist for the various types of Nb targets studied. For example, for room-temperature irradiation of annealed polycrystalline Nb the experimentally determined relationship is Datsub mpat<10.3tatsup 1.22at. Furthermore, the D-t relationship was found to depend on the irradiation temperature in contrast to theoretical predictions by the lateral stress model of blister formation. These results do not appear to support the lateral stress model which predicts the relationship Dproportionaltatsup 1.5at. However, the experimentally determined relationships can be explained in part by the gas pressure model of blister formation

  14. Properties of the Plasma Surrounding the Global Heliosphere Determined with Voyager 1&2 ions and ENA/INCA Observations at E > 5 keV

    Science.gov (United States)

    Krimigis, S. M.; Dialynas, K.; Mitchell, D. G.; Decker, R. B.; Roelof, E. C.

    2016-12-01

    The basic goal of the proposed Interstellar Mapping and Acceleration Probe (IMAP) is detailed scientific understanding of the Heliosheath (HS) and beyond, a region of space explored in situ by Voyager 1 (V1) since 2004, Voyager 2 (V2) since 2007, and remotely via energetic neutral atoms (ENA) by the Cassini/INCA (5.2-55 keV) since 2003 and IBEX (0.3-6 keV) since 2009. The partial overlap in energies (28 5 keV, the rest residing below that range, resulting in a beta (particle/magnetic pressure) always > 1, typically >10. (2) Based on the ENA-derived hot ion pressures, the interstellar magnetic field (ISMF) was predicted to be more than twice that expected in the literature i.e. similar to what was measured by V1 after crossing the heliopause (B 0.5 nT). (3) The width of the HS in the direction of V1 is 30 AU (predicted by INCA before the V1 HP crossing), but is thought to be larger (40-70 AU) in the southern ecliptic where V2, now 30 AU into the HS, currently travels. We address here the key question of the source of 5-55 keV ENAs that INCA measures. The analysis of INCA all-sky maps from 2003 to 2014 show that the decrease and recovery of ENA in the global heliosphere during this period (declining phase of SC23 and rise of SC24) is similar to that of the ions at V1/V2, consistent with the HS ions being the source of ENA. The close correspondence between ENA and ion spectra (despite the 140 AU distance between V1 and V2) as well as the similarity of ENA spectra over the nose and anti-nose directions, together with the recent V1 measurement of a BISMF 0.5nT, suggest that the global distributions of >5 keV ions in the heliosheath resembles a diamagnetic bubble with no significant tail-like feature (the alternative Parker 1961 model), also consistent with some recent MHD simulations and models.

  15. Microstructure of RERTR DU-alloys irradiated with krypton ions up to 100 dpa

    Energy Technology Data Exchange (ETDEWEB)

    Gan, J. [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Keiser, D.D., E-mail: Dennis.Keiser@inl.gov [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Miller, B.D.; Wachs, D.M. [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Allen, T.R. [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Drive, Madison, WI 53706 (United States); Kirk, M.; Rest, J. [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave, Argonne, IL 60439 (United States)

    2011-04-15

    The radiation stability of the interaction product formed at the fuel-matrix interface of research reactor dispersion fuels, under fission-product bombardment, has a strong impact on fuel performance. Three depleted uranium alloys were cast that consisted of the following five phases to be investigated: U(Si, Al){sub 3}, (U, Mo)(Si, Al){sub 3}, UMo{sub 2}Al{sub 20}, U{sub 6}Mo{sub 4}Al{sub 43}, and UAl{sub 4}. Irradiation of transmission electron microscopy (TEM) disc samples with 500-keV Kr ions at 200 deg. C to doses up to {approx}100 displacements per atom (dpa) were conducted using a 300-keV electron microscope equipped with an ion accelerator. TEM results show that the U(Si, Al){sub 3} and UAl{sub 4} phases remain crystalline at 100 dpa without forming voids. The (U, Mo)(Si, Al){sub 3} and UMo{sub 2}Al{sub 20} phases become amorphous at 1 and {approx}2 dpa, respectively, and show no evidence of voids at 100 dpa. The U{sub 6}Mo{sub 4}Al{sub 43} phase goes to amorphous at less than 1 dpa and reveals high density voids at 100 dpa.

  16. Microstructure of RERTR DU-alloys irradiated with krypton ions up to 100 dpa

    Science.gov (United States)

    Gan, J.; Keiser, D. D., Jr.; Miller, B. D.; Wachs, D. M.; Allen, T. R.; Kirk, M.; Rest, J.

    2011-04-01

    The radiation stability of the interaction product formed at the fuel-matrix interface of research reactor dispersion fuels, under fission-product bombardment, has a strong impact on fuel performance. Three depleted uranium alloys were cast that consisted of the following five phases to be investigated: U(Si, Al) 3, (U, Mo)(Si, Al) 3, UMo 2Al 20, U 6Mo 4Al 43, and UAl 4. Irradiation of transmission electron microscopy (TEM) disc samples with 500-keV Kr ions at 200 °C to doses up to ˜100 displacements per atom (dpa) were conducted using a 300-keV electron microscope equipped with an ion accelerator. TEM results show that the U(Si, Al) 3 and UAl 4 phases remain crystalline at 100 dpa without forming voids. The (U, Mo)(Si, Al) 3 and UMo 2Al 20 phases become amorphous at 1 and ˜2 dpa, respectively, and show no evidence of voids at 100 dpa. The U 6Mo 4Al 43 phase goes to amorphous at less than 1 dpa and reveals high density voids at 100 dpa.

  17. Computer simulation of range and damage distributions of 0.5 to 8 keV helium ions in crystalline and amorphous niobium

    International Nuclear Information System (INIS)

    Maderlechner, G.

    1976-03-01

    The binary collision cascade simulation program MARLOWE is used to study the influence of the crystal lattice, electronic energy loss and crystal temperature on the range and damage distributions of 0.5 to 8 keV He ions penetrating into a Nb target. If the ions enter the crystal parallel to the close-packed direction, the penetration depth profiles show temperature dependent channeling and dechanneling effects. The range distributions in amorphous Nb agree generally with Lindhard's transport theory if surface effects are taken into account. The damage distributions are nearly independent of the electronic energy loss models. The number of vacancies per incident ion increases linearly with the mean nuclear energy loss of the ion in amorphous as well as in crystalline Nb. (orig./GSCH) [de

  18. 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

  19. Ion beam irradiation as a tool to improve the ionic conductivity in solid polymer electrolyte systems

    Energy Technology Data Exchange (ETDEWEB)

    Manjunatha, H., E-mail: h-manjunath@blr.amrita.edu; Kumaraswamy, G. N. [Department of Physics, Amrita Vishwa Vidyapeetham, Bengaluru-560 035 (India); Damle, R. [Department of Physics, Bangalore University, Bengaluru-560 056 (India)

    2016-05-06

    Solid polymer electrolytes (SPEs) have potential applications in solid state electronic and energy devices. The optimum conductivity of SPEs required for such applications is about 10{sup −1} – 10{sup −3} Scm{sup −1}, which is hard to achieve in these systems. It is observed that ionic conductivity of SPEs continuously increase with increasing concentration of inorganic salt in the host polymer. However, there is a critical concentration of the salt beyond which the conductivity of SPEs decreases due to the formation of ion pairs. In the present study, solid polymer thin films based on poly (ethylene oxide) (PEO) complexed with NaBr salt with different concentrations have been prepared and the concentration at which ion pair formation occurs in PEO{sub x}NaBr is identified. The microstructure of the SPE with highest ionic conductivity is modified by irradiating it with low energy O{sup +1} ion (100 keV) of different fluencies. It is observed that the ionic conductivity of irradiated SPEs increases by one order in magnitude. The increase in ionic conductivity may be attributed to the enhanced segmental motion of the polymer chains due to radiation induced micro structural modification.

  20. 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.

  1. 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

  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. 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)

  7. 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

  8. 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

  9. Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling

    International Nuclear Information System (INIS)

    Mayer, Marcel; Keskinbora, Kahraman; Grévent, Corinne; Szeghalmi, Adriana; Knez, Mato; Weigand, Markus; Snigirev, Anatoly; Snigireva, Irina; Schütz, Gisela

    2013-01-01

    The fabrication and performance of multilayer Al 2 O 3 /Ta 2 O 5 Fresnel zone plates in the hard X-ray range and a discussion of possible future developments considering available materials are reported. Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ∼10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling, FZPs with very high aspect ratios were prepared. Such multilayer FZPs with outermost zone widths of 10 and 35 nm and aspect ratios of up to 243 were tested for their focusing properties at 8 keV and shown to focus hard X-rays efficiently. This success was enabled by the outstanding layer quality thanks to ALD. Via the use of FIB for slicing the multilayer structures, desired aspect ratios could be obtained by precisely controlling the thickness. Experimental diffraction efficiencies of multilayer FZPs fabricated via this combination reached up to 15.58% at 8 keV. In addition, scanning transmission X-ray microscopy experiments at 1.5 keV were carried out using one of the multilayer FZPs and resolved a 60 nm feature size. Finally, the prospective of different material combinations with various outermost zone widths at 8 and 17 keV is discussed in the light of the coupled wave theory and the thin-grating approximation. Al 2 O 3 /Ir is outlined as a promising future material candidate for extremely high resolution with a theoretical efficiency of more than 20% for as small an outermost zone width as 10 nm at 17 keV

  10. Comparative study of 150 keV Ar+ and O+ ion implantation induced structural modification on electrical conductivity in Bakelite polymer

    Science.gov (United States)

    Aneesh Kumar, K. V.; Krishnaveni, S.; Asokan, K.; Ranganathaiah, C.; Ravikumar, H. B.

    2018-02-01

    A comparative study of 150 keV argon (Ar+) and oxygen (O+) ion implantation induced microstructural modifications in Bakelite Resistive Plate Chamber (RPC) detector material at different implantation fluences have been studied using Positron Annihilation Lifetime Spectroscopy (PALS). Positron lifetime parameters viz., o-Ps lifetime (τ3) and its intensity (I3) upon lower implantation fluences can be interpreted as the cross-linking and the increased local temperature induced diffusion followed by trapping of ions in the interior polymer voids. The increased o-Ps lifetime (τ3) at higher O+ ion implantation fluences indicates chain scission owing to the oxidation and track formation. This is also justified by the X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) results. The modification in the microstructure and electrical conductivity of Bakelite materials are more upon implantation of O+ ions than Ar+ ions of same energy and fluences. The reduced electrical conductivity of Bakelite polymer material upon ion implantation of both the ions is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate energy and fluence of implanting ions might reduce the leakage current and hence improve the performance of Bakelite RPC detectors.

  11. Ion Beam Materials Analysis and Modifications at keV to MeV Energies at the University of North Texas

    Science.gov (United States)

    Rout, Bibhudutta; Dhoubhadel, Mangal S.; Poudel, Prakash R.; Kummari, Venkata C.; Lakshantha, Wickramaarachchige J.; Manuel, Jack E.; Bohara, Gyanendra; Szilasi, Szabolcs Z.; Glass, Gary A.; McDaniel, Floyd D.

    2014-02-01

    The University of North Texas (UNT) Ion Beam Modification and Analysis Laboratory (IBMAL) has four particle accelerators including a National Electrostatics Corporation (NEC) 9SDH-2 3 MV tandem Pelletron, a NEC 9SH 3 MV single-ended Pelletron, and a 200 kV Cockcroft-Walton. A fourth HVEC AK 2.5 MV Van de Graaff accelerator is presently being refurbished as an educational training facility. These accelerators can produce and accelerate almost any ion in the periodic table at energies from a few keV to tens of MeV. They are used to modify materials by ion implantation and to analyze materials by numerous atomic and nuclear physics techniques. The NEC 9SH accelerator was recently installed in the IBMAL and subsequently upgraded with the addition of a capacitive-liner and terminal potential stabilization system to reduce ion energy spread and therefore improve spatial resolution of the probing ion beam to hundreds of nanometers. Research involves materials modification and synthesis by ion implantation for photonic, electronic, and magnetic applications, micro-fabrication by high energy (MeV) ion beam lithography, microanalysis of biomedical and semiconductor materials, development of highenergy ion nanoprobe focusing systems, and educational and outreach activities. An overview of the IBMAL facilities and some of the current research projects are discussed.

  12. 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.

  13. 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)

  14. 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

  15. 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.

  16. 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

  17. 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)

  18. Effect of field size on determination of mean free path of a magnetized mortar irradiated with energy photons between 65 and 1250 keV

    International Nuclear Information System (INIS)

    Andrade, M. Paes de; Vieira, J.W.; Filho, Joao Antonio

    2011-01-01

    The size effect of the radiation field in determining the half value layer (HVL) and the relaxation length of a magnetized mortar was evaluated for photon beams of energy between 65 and 1250 keV. The mortar consists of water, cement, limonite and magnetite has been shaped and constructed a computer simulation of photon beam attenuation for different radiation fields with diameters between 3 and 20 cm using the Monte Carlo code Penelope. For the same energy and different sizes of the radiation field, the ratio of HVL and μx showed a deviation of up to 21% when the radiation beam was attenuated 99%. It was concluded that the experimental determination of the magnitudes of the HVL and μx for the mortar and the irradiation conditions used in this study were made with narrow radiation fields. (author)

  19. 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

  20. Correlation between blister skin thickness, the maximum in the damage-energy distribution, and projected ranges of helium ions in Nb for the energy range 10 to 1500 keV

    International Nuclear Information System (INIS)

    St-Jacques, R.G.; Martel, J.G.; Terreault, B.; Veilleux, G.; Das, S.K.; Kaminsky, M.; Fenske, G.

    1976-01-01

    The skin thickness of blisters formed on polycrystalline niobium by 4 He + irradiation at room temperature for energies from 15 to 80 keV have been measured. Similar measurements were conducted for 10 keV 4 He + irradiation at 500 0 C to increase blister exfoliation, and thereby allow examination of a larger number of blister skins. For energies smaller than 100 keV the skin thicknesses are compared with the projected range and the damage-energy distributions constructed from moments interpolated from Winterbon's tabulated values. For energies of 10 and 15 keV the projected ranges and damage-energy distributions have also been computed with a Monte Carlo program. For energies larger than 100 keV the projected ranges of 4 He + in Nb were calculated using either Brice's formalism or the one given by Schiott. The thicknesses for 60 and 80 keV, and those reported earlier for 100 to 1500 keV correlate well with calculated projected ranges. For energies lower than 60 keV the measured thicknesses are larger than the calculated ranges

  1. 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

  2. Depth distribution of bubbles in 4He+-ion irradiated nickel and the mechanism of blister formation

    International Nuclear Information System (INIS)

    Fenske, G.; Das, S.K.; Kaminsky, M.; Miley, G.H.

    1978-01-01

    While the radiation blistering phenomenon has been widely studied, the mechanism of blister formation is still not well understood. The present studies on depth distribution of helium bubbles in nickel were carried out in order to obtain a better understanding of the radiation blistering process. Particularly, the aim was to understand the experimental observation that the blister skin thickness for many metals irradiated with He + ions of energies lower than 20-keV is a factor of two or more larger than the calculated projected range. (Auth.)

  3. 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)

  4. 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)

  5. 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.

  6. 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

  7. 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

  8. Tuning the antiferromagnetic to ferromagnetic phase transition in FeRh thin films by means of low-energy/low fluence ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Heidarian, A.; Bali, R.; Grenzer, J.; Wilhelm, R.A.; Heller, R.; Yildirim, O.; Lindner, J.; Potzger, K.

    2015-09-01

    Ion irradiation induced modifications of the thermomagnetic properties of equiatomic FeRh thin films have been investigated. The application of 20 keV Ne{sup +} ions at different fluencies leads to broadening of the antiferromagnetic to ferromagnetic phase transition as well as a shift of the transition temperature towards lower temperatures with increasing ion fluence. Moreover, the ferromagnetic background at low temperatures generated by the ion irradiation leads to pronounced saturation magnetisation at 5 K. Complete erasure of the transition, i.e. ferromagnetic ordering through the whole temperature regime was achieved at a Ne{sup +} fluence of 3 × 10{sup 14} ions/cm{sup 2}. It does not coincide with the complete randomization of the chemical ordering of the crystal lattice.

  9. L-shell X-ray production of molybdenum and niobium induced by 1500–3500 keV Xe26+ ions

    International Nuclear Information System (INIS)

    Guo, Yipan; Yang, Zhihu; Song, Zhangyong; Xu, Qiumei; Chen, Jing; Yang, Bian

    2013-01-01

    L-shell X-ray production cross sections are measured for molybdenum and niobium target induced by Xe 26+ ions. The incident energy range varies from 1500 to 3500 keV. The experimental results are well reproduced by the binding-energy-modified binary encounter approximation model in the united-atom limit. In addition to target L-shell X-ray spectra, we also observe a weak spectrum which corresponds to the forbidden transition 3d → 2s from the projectiles

  10. Charge-transfer cross sections of H+ ions in collisions with noble gas atoms in the energy range below 4.0 keV

    International Nuclear Information System (INIS)

    Kusakabe, Toshio; Sakaue, Hiroyuki A.; Tawara, Hiroyuki

    2011-01-01

    Charge-transfer cross sections in collisions of H + ions with the ground state He, Ar, Kr, and Xe atoms have been measured in the energy range below 4.0 keV with the initial growth rate method. These observed cross sections are also compared with previously published experimental data and theoretical predictions. In the He and Ar targets, it is found that some previous experimental data deviate significantly from the present observed cross sections as the collision energy decreases. It has been found that in the Kr and Xe targets, the energy dependence of the present observed cross sections behaves as “near-resonant” charge transfer. (author)

  11. 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.

  12. Effect of solute atoms on swelling in Ni alloys and pure Ni under He + ion irradiation

    Science.gov (United States)

    Wakai, E.; Ezawa, T.; Imamura, J.; Takenaka, T.; Tanabe, T.; Oshima, R.

    2002-12-01

    The effects of solute atoms on microstructural evolutions have been investigated using Ni alloys under 25 keV He + irradiation at 500 °C. The specimens used were pure Ni, Ni-Si, Ni-Co, Ni-Cu, Ni-Mn and Ni-Pd alloys with different volume size factors. The high number densities of dislocation loops about 1.5×10 22 m -3 were formed in the specimens irradiated to 1×10 19 ions/m 2, and they were approximately equivalent, except for Ni-Si. The mean size of loops tended to increase with the volume size factor of solute atoms. In a dose of 4×10 20 ions/m 2, the swelling was changed from 0.2% to 4.5%, depending on the volume size factors. The number densities of bubbles tended to increase with the absolute values of the volume size factor, and the swelling increased with the volume size factors. This suggests that the mobility of helium and vacancy atoms may be influenced by the interaction of solute atoms with them.

  13. 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)

  14. Radiation-induced segregation and void formation in C+ ion-irradiated vanadium-carbon alloys

    International Nuclear Information System (INIS)

    Takeyama, T.; Ohnuki, S.; Takahashi, H.; Sato, Y.; Mochizuki, S.

    1982-01-01

    To clarify the effect of interstitial elements on radiation-induced segregation and void formation in V and V-C alloys irradiated by 200 keV C + ions to a dose of 48 dpa at 973 K, the microstructural observation and the measurement of C segregation to the surfaces were carried out by TEM and XPS. Voids, dislocations and precipitates were produced in all of the specimens during irradiation. The addition of C in V led to a reduction of void size and to increase in void number density, consequently the void swelling was suppressed strongly. Radiation-induced segregation of C was observed clearly on and near the irradiated surfaces of V-C alloys and as a result of the enrichment of C atoms, carbides precipitated on the surfaces. It is the first evidence of the radiation-induced segregation of interstitial elements on the surfaces. Also, quasi-carbides were observed on the (210) habit plaints near large voids and dislocations in V. The phenomena show that C atoms, which was insolved and/or implanted, interact strongly with vacancies rather than self-interstitial atoms and migrate with vacancies toward defect sinks, such as surfaces, voids, and dislocations. The segregated zones of C reduced the sink efficiency of the defects, and showed the effect of the suppression on void in V-C alloys. (author)

  15. 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

  16. Role of isolated and clustered DNA damage and the post-irradiating repair process in the effects of heavy ion beam irradiation

    International Nuclear Information System (INIS)

    Tokuyama, Yuka; Terato, Hiroaki; Furusawa, Yoshiya; Ide, Hiroshi; Yasui, Akira

    2015-01-01

    Clustered DNA damage is a specific type of DNA damage induced by ionizing radiation. Any type of ionizing radiation traverses the target DNA molecule as a beam, inducing damage along its track. Our previous study showed that clustered DNA damage yields decreased with increased linear energy transfer (LET), leading us to investigate the importance of clustered DNA damage in the biological effects of heavy ion beam radiation. In this study, we analyzed the yield of clustered base damage (comprising multiple base lesions) in cultured cells irradiated with various heavy ion beams, and investigated isolated base damage and the repair process in post-irradiation cultured cells. Chinese hamster ovary (CHO) cells were irradiated by carbon, silicon, argon and iron ion beams with LETs of 13, 55, 90 and 200 keV µm -1 , respectively. Agarose gel electrophoresis of the cells with enzymatic treatments indicated that clustered base damage yields decreased as the LET increased. The aldehyde reactive probe procedure showed that isolated base damage yields in the irradiated cells followed the same pattern. To analyze the cellular base damage process, clustered DNA damage repair was investigated using DNA repair mutant cells. DNA double-strand breaks accumulated in CHO mutant cells lacking Xrcc1 after irradiation, and the cell viability decreased. On the other hand, mouse embryonic fibroblast (Mef) cells lacking both Nth1 and Ogg1 became more resistant than the wild type Mef. Thus, clustered base damage seems to be involved in the expression of heavy ion beam biological effects via the repair process. (author)

  17. Formation of hexagonal silicon carbide by high energy ion beam irradiation on Si (1 0 0) substrate

    International Nuclear Information System (INIS)

    Bhuyan, H; Favre, M; Valderrama, E; Avaria, G; Chuaqui, H; Mitchell, I; Wyndham, E; Saavedra, R; Paulraj, M

    2007-01-01

    We report the investigation of high energy ion beam irradiation on Si (1 0 0) substrates at room temperature using a low energy plasma focus (PF) device operating in methane gas. The unexposed and ion exposed substrates were characterized by x-ray diffraction, scanning electron microscopy (SEM), photothermal beam deflection, energy-dispersive x-ray analysis and atomic force microscopy (AFM) and the results are reported. The interaction of the pulsed PF ion beams, with characteristic energy in the 60-450 keV range, with the Si surface, results in the formation of a surface layer of hexagonal silicon carbide. The SEM and AFM analyses indicate clear step bunching on the silicon carbide surface with an average step height of 50 nm and a terrace width of 800 nm

  18. 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

  19. 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.

  20. International Fusion Materials Irradiation Facility injector acceptance tests at CEA/Saclay: 140 mA/100 keV deuteron beam characterization

    International Nuclear Information System (INIS)

    Gobin, R.; Bogard, D.; Chauvin, N.; Chel, S.; Delferrière, O.; Harrault, F.; Mattei, P.; Senée, F.; Cara, P.; Mosnier, A.; Shidara, H.; Okumura, Y.

    2014-01-01

    In the framework of the ITER broader approach, the International Fusion Materials Irradiation Facility (IFMIF) deuteron accelerator (2 × 125 mA at 40 MeV) is an irradiation tool dedicated to high neutron flux production for future nuclear plant material studies. During the validation phase, the Linear IFMIF Prototype Accelerator (LIPAc) machine will be tested on the Rokkasho site in Japan. This demonstrator aims to produce 125 mA/9 MeV deuteron beam. Involved in the LIPAc project for several years, specialists from CEA/Saclay designed the injector based on a SILHI type ECR source operating at 2.45 GHz and a 2 solenoid low energy beam line to produce such high intensity beam. The whole injector, equipped with its dedicated diagnostics, has been then installed and tested on the Saclay site. Before shipment from Europe to Japan, acceptance tests have been performed in November 2012 with 100 keV deuteron beam and intensity as high as 140 mA in continuous and pulsed mode. In this paper, the emittance measurements done for different duty cycles and different beam intensities will be presented as well as beam species fraction analysis. Then the reinstallation in Japan and commissioning plan on site will be reported

  1. 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.

  2. TEM Characterization of Helium Bubbles in T91 and MNHS Steels Implanted with 200 keV He Ions at Different Temperatures

    International Nuclear Information System (INIS)

    Wang Ji; Gao Xing; Wang Zhi-Guang; Wei Kong-Fang; Yao Cun-Feng; Cui Ming-Huan; Sun Jian-Rong; Li Bing-Sheng; Pang Li-Long; Zhu Ya-Bin; Luo Peng; Chang Hai-Long; Zhang Hong-Peng; Zhu Hui-Ping; Wang Dong; Du Yang-Yang; Xie Er-Qing

    2015-01-01

    Modified novel high silicon steel (MNHS, a newly developed reduced-activation martensitic alloy) and commercial alloy T91 are implanted with 200 keV He"2"+ ions to a dose of 5 × 10"2"0 ions/m"2 at 300, 450 and 550°C. Transmission electron microscopy (TEM) is used to characterize the size and morphology of He bubbles. With the increase of the implantation temperature, TEM observations indicate that bubbles increase in size and the proportion of ‘brick shaped’ cuboid bubbles increases while the proportion of polyhedral bubbles decreases in both the steel samples. For the samples implanted at the same temperature, the average size of He bubbles in MNHS is smaller than that in T91. This might be due to the abundance of boundaries and precipitates in MNHS, which provide additional sites for the trapping of He atoms, thus reduce the susceptibility of MNHS to He embrittlement. (paper)

  3. Implantation of Fe ions into aluminium fast cooled tapes; Vliyanie bombardirovki c uskorennymi do 70 keV jonami na structuru i svoistva alyuminievogo splava

    Energy Technology Data Exchange (ETDEWEB)

    Dimova, V; Danailov, D; Markov, T; Zlateva, G [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. po Metaloznanie i Tekhnologiya na Metalite; Angelov, Kh [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. za Yadrena Izsledvaniya i Yadrena Energetika

    1996-12-31

    Aluminium alloy containing 1% Zn is investigated as a material for fusion reactor first wall. The effect of 60 keV Fe ion implantation at a dose 10{sup 16}-10{sup 17} cm{sup -2} on the microstructure and properties of 50 {mu}m thick tapes has been investigated. It is found that implantation affects mainly the surface at the crystallite boundaries. An over-equilibrium solubility of Fe in the alloy Al-1% Zn has been established. Fe ions move by diffusion along the grain boundaries and contribute to increased magnetic properties after annealing at 250{sup o} C for at least 2 hours. Quasi-amorphous implanted alloy containing ferromagnetic atoms has been detected. The estimated Curie temperature has been estimated to 540 {sup o} C, which is typical for strongly diluted solid solutions. 3 refs., 6 figs.

  4. Characteristics of ZnO Wafers Implanted with 60 keV Sn+ Ions at Room Temperature and at 110 K

    International Nuclear Information System (INIS)

    Dang, Giang T.; Taniwaki, Masafumi; Kawaharamura, Toshiyuki; Hirao, Takashi; Nitta, Noriko

    2011-01-01

    ZnO wafers implanted with 60 keV Sn + ions at room temperature (RT) and at 110 K are investigated by means of X-ray diffraction (XRD) and photoluminescence (PL) techniques. The effect of implantation temperature is evident in the XRD and PL data. A yellow-orange (YO) band near 600 nm appears in the PL spectra of the ZnO wafers implanted to the doses of 4x10 14 and 8x10 14 ions/cm 2 at RT. The intensity of this band increases and the peak position blue-shifts after illumination of the samples with the 325 nm line of a He-Cd laser. The PL data suggests that the CB (conduction band)→V O + and Zn i + →V Zn - transitions contribute to the photoemission of the YO band.

  5. Degradation mechanisms of optoelectric properties of GaN via highly-charged 209Bi33+ ions irradiation

    Science.gov (United States)

    Zhang, L. Q.; Zhang, C. H.; Xian, Y. Q.; Liu, J.; Ding, Z. N.; Yan, T. X.; Chen, Y. G.; Su, C. H.; Li, J. Y.; Liu, H. P.

    2018-05-01

    N-type gallium nitride (GaN) epitaxial layers were subjected to 990-keV Bi33+ ions irradiation to various fluences. Optoelectric properties of the irradiated-GaN specimens were studied by means of Raman scattering and variable temperature photoluminescence (PL) spectroscopy. Raman spectra reveal that both the free-carrier concentration and its mobility generally decrease with a successive increase in ion fluence. Electro-optic mechanisms dominated the electrical transport to a fluence of 1.061 × 1012 Bi33+/cm2. Above this fluence, electrical properties were governed by the deformation potential. The appearance of vacancy-type defects results in an abrupt degradation in electrical transports. Varying temperature photoluminescence (PL) spectra display that all emission lines of 1.061 × 1012 Bi33+/cm2-irradiated specimen present a general remarkable thermal redshift, quenching, and broadening, including donor-bound-exciton peak, yellow luminescence band, and LO-phonon replicas. Moreover, as the temperature rises, a transformation from excitons (donor-acceptor pairs' luminescence) to band-to-band transitions (donor-acceptor combinations) was found, and the shrinkage effect of the band gap dominated the shift of the peak position gradually, especially the temperature increases above 150 K. In contrast to the un-irradiated specimen, a sensitive temperature dependence of all photoluminescence (PL) lines' intensity obtained from 1.061 × 1012 Bi33+/cm2-irradiated specimen was found. Mechanisms underlying were discussed.

  6. 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

  7. 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)

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

    International Nuclear Information System (INIS)

    Kuzmann, E.; Spirov, I.N.

    1984-01-01

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

  9. 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

  10. Molecular dynamics simulations of the role of electronic losses in damage creation of ion irradiated Tungsten

    International Nuclear Information System (INIS)

    Maya, P.N.; Deshpande, S.P

    2014-01-01

    Damage creation due to the irradiation of 14 MeV fusion neutrons and the subsequent mechanical failure and alteration of the fuel retention properties of tungsten plasma-facing materials is one of the major concerns of the fusion reactors. In addition to nuclear reactions and the subsequent transmutations, the energetic neutron impars its kinetic energy either partly or completely to a lattice tungsten atom thereby creating a primary knock-on atom (PKA) which, is considered as the onset of damage creation in the lattice. The PKA continues to undergo collisions with the lattice atoms which eventually leads to a collision cascade. In order to understand the collision process, one often simulates such systems using surrogate ions, such as energetic W ions itself, in particle accelerators and due to the experimental constraints (such as the stability of the beam) one often has to opt for high energetic ion beams (∼ 30 MeV) which surpasses the PKA energies created by neutron (∼100s of KeV) in W. Hence it is important to distinguish how the very high energetic tungsten atoms interact with the lattice atoms in comparison with the low energy PKA created by the neutron. One of the key difference is that at higher energies the electronic losses become important which decides the collision dynamics. In this presentation the effect of electronic losses in the damage creation using molecular dynamics simulations have been discussed

  11. Formation, properties, and ion irradiation effects of hexagonal structure MoN thin films

    International Nuclear Information System (INIS)

    Christen, D.K.; Sekula, S.T.; Ellis, J.T.; Lewis, J.D.; Williams, J.M.

    1986-09-01

    Thin films (100-120 nm) of hexagonal structures MoN have been fabricated by reaction of Mo films in an NH 3 atmosphere. The as-formed films possessed superconducting transition temperatures T/sub c/ ≅ 13 0 K, with resistance ratios r = R(296K)/R(T/sub c/) in the range 5 to 10, low-temperature normal state resistivities rho 0 = 4 to 10 μΩ-cm, and extrapolated upper critical fields H/sub c2/(0) = 4.0 to 5.0 T. Thin film x-ray diffraction patterns revealed no visible second phase, with measured lattice parameters close to literature values. The effects of lattice disorder on the superconducting and electronic properties were investigated by irradiation with nitrogen ions of energy 45 and 340 keV, resulting in a nearly uniform damage profile without the introduction of any new chemical species. The results indicate that ordered hexagonal MoN shows some of the unusual properties characteristic of moderate-to-high T/sub c/ transition metal compounds, but is relatively insensitive to degradation of the superconducting properties by lattice disorder. For ion fluences PHI up to 2 x 10 16 N-ions/cm 2 , T/sub c/ is found to decrease monotonically and saturate at 9.5 0 K, almost 3/4 the initial value, while H/sub c2/(0) undergoes a gradual increase to 11T

  12. 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)

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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...

  18. 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)

  19. 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)

  20. 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

  1. 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)

  2. MeV ion irradiation effects on the luminescence properties of Si-implanted SiO{sub 2}-thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chulapakorn, T.; Primetzhofer, D. [Uppsala University, Department of Physics and Astronomy, P.O. Box 516, 751 20 Uppsala (Sweden); Sychugov, I.; Suvanam, S.S.; Linnros, J.; Hallen, A. [Royal Institute of Technology (KTH), School of Information and Communication Technology, P.O. Box Electrum 229, 164 40 Kista (Sweden)

    2016-12-15

    The effects of MeV heavy ion irradiation at varying fluence and flux on excess Si, introduced in SiO{sub 2} by keV ion implantation, are investigated by photoluminescence (PL). From the PL peak wavelength (λ) and decay lifetime (τ), two PL sources are distinguished: (i) quasi-direct recombination of excitons of Si-nanoparticles (SiNPs), appearing after thermal annealing (λ > 720 nm, τ ∝ μs), and (ii) fast-decay PL, possibly due to oxide-related defects (λ ∝ 575-690 nm, τ ∝ ns). The fast-decay PL (ii) observed before and after ion irradiation is induced by ion implantation. It is found that this fast-decay luminescence decreases for higher irradiation fluence of MeV heavy ions. After thermal annealing (forming SiNPs), the SiNP PL is reduced for samples irradiated by MeV heavy ions but found to stabilize at higher level for higher irradiation flux; the (ii) band vanishes as a result of annealing. The results are discussed in terms of the influence of electronic and nuclear stopping powers. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. 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

  4. 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

  5. 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)

  6. 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.)

  7. [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

  8. 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

  9. 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.).

  10. Secondary Electron Emission from Solid Hydrogen and Deuterium Resulting from Incidence of keV Electrons and Hydrogen Ions

    DEFF Research Database (Denmark)

    Sørensen, H.

    1977-01-01

    are small, in contrast to what is expected for insulating materials. One explanation is that the secondary electrons lose energy inside the target material by exciting vibrational and rotational states of the molecules, so that the number of electrons that may escape as secondary electrons is rather small....... The losses to molecular states will be largest for hydrogen, so that the SEE coefficients are smallest for solid hydrogen, as was observed. For the incidence of ions, the values of δ for the different molecular ions agree when the number of secondary electrons per incident atom is plotted versus the velocity...... or the stopping power of the incident particles. Measurements were also made for oblique incidence of H+ ions on solid deuterium for angles of incidence up to 75°. A correction could be made for the emission of secondary ions by also measuring the current calorimetrically. At largest energies, the angular...

  11. 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

  12. 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

  13. 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...

  14. Experimental study of the dissociation of 100-600 KeV hydrogen cluster ions in an argon gas target

    International Nuclear Information System (INIS)

    Chevallier, M.; Clouvas, A.; Frischkorn, H.J.; Gaillard, M.J.; Poizat, J.C.; Remillieux, J.

    1985-09-01

    We have studied the break-up of accelerated hydrogen cluster ions passing through an argon gas target. The absolute dissociation cross section has been measured for a wide variety of H n + (odd masses only) cluster ions, with n between 5 and 23 and with projectile velocities ranging from 1.5 to 5 x 10 8 cm/s. We discuss the dissociation processes and the dependence of their cross-sections upon the cluster mass and velocity

  15. Formation of low friction and wear-resistant carbon coatings on tool steel by 75keV, high-dose carbon ion implantation

    International Nuclear Information System (INIS)

    Mikkelsen, N.J.; Eskildsen, S.S.; Straede, C.A.; Chechenin, N.G.

    1994-01-01

    Hardened AISI D2 steel samples were subjected to mass-separated C + ion bombardment at 75keV with ion doses in the range 0.5-15x10 18 C + cm -2 . It was observed that sputtering was still limited, and the system exhibited internal growth, because most of the ions penetrated more than 0.1μm into the growing carbon film. At the lowest ion doses applied, carbon was implanted into the steel, while higher doses resulted in the implanted carbon concentration near the surface being almost 100%. For the highest doses applied, Rutherford backscattering spectrometry and surface profilometry analyses showed that layers about 0.5-1μm thick of almost pure carbon grew outward from the steel substrate. Transmission electron microscopy showed that the carbon layers were amorphous and exhibited an intermixed layer-substrate interface. The layers were hard and exhibited pronounced elastic recovery when subjected to ultralow load indentation. Low friction and excellent wear properties were measured when tested under dry conditions with a ball-on-disc tribometer. ((orig.))

  16. 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

  17. 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

  18. 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)

  19. 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

  20. Developments at an electrostatic cryogenic storage ring for electron-cooled keV energy ion beams

    International Nuclear Information System (INIS)

    Vogel, Stephen

    2016-01-01

    This work is devoted to final setup activities and the commissioning of an electrostatic cryogenic storage ring (CSR) at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg. The first cryogenic operation of CSR in 2015 has been documented and characterized using a set of non-destructive beam diagnostic tools developed within this work. These are (1) the current pick-up system for the determination of the current of the stored ion beam and its velocity, (2) a position pick-up system for measuring the transverse position of the ion beam center at six symmetric locations of the storage ring circumference, and (3) a Schottky pick-up system for the monitoring of coasting ion beams. Despite the requirements imposed by the cryogenic operation, the developed diagnostic system demonstrated its full functionality. First characterizations of the storage ring properties and the performance of the diagnostic system are presented. Based on previous work, an electron cooling system for CSR has been developed and largely realized. With the implementation into CSR in 2016, the electron cooler will enhance the storage ring into a unique experimental facility for electron-ion collision studies. With this CSR is on the track to become the first cryogenic storage ring featuring actively cooled ion beams.

  1. 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

  2. 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

  3. Guided transmission of 3 keV Ar{sup 7+} ions through dense polycarbonate nanocapillary arrays: Blocking effect and time dependence of the transmitted neutrals

    Energy Technology Data Exchange (ETDEWEB)

    Juhasz, Z. [Institute of Nuclear Research (ATOMKI), Bem ter 18/c, H-4026 Debrecen (Hungary); Kovacs, S.T.S., E-mail: kovacss@atomki.hu [Institute of Nuclear Research (ATOMKI), Bem ter 18/c, H-4026 Debrecen (Hungary); Herczku, P.; Racz, R.; Biri, S.; Rajta, I.; Gal, G.A.B.; Szilasi, S.Z. [Institute of Nuclear Research (ATOMKI), Bem ter 18/c, H-4026 Debrecen (Hungary); Palinkas, J. [Department of Experimental Physics, University of Debrecen, Egyetem ter 1, H-4032 Debrecen (Hungary); Sulik, B. [Institute of Nuclear Research (ATOMKI), Bem ter 18/c, H-4026 Debrecen (Hungary)

    2012-05-15

    In the present work dynamic properties of 3 keV Ar{sup 7+} ions guided through polycarbonate (PC) nanocapillaries at different tilt angles ranging from 1 Degree-Sign to 7 Degree-Sign are studied together with the transmitted neutrals. Two-dimensional transmission profiles were measured with a position sensitive detector. The guided ions and the transmitted neutrals were separated by an electrostatic deflector. The measured quantities are plotted as function of deposited charge in the surface of the sample, which is regarded as a measure of time. We found weak oscillations in the position of transmission profiles. Depending on the tilt angle the intensity of ions started from zero or from a small value and increased fast at the beginning. After reaching a maximum, it strongly decreased in time, similarly as in previous measurements with PC capillaries. This phenomenon is called as blocking effect. The time dependence of the intensity of neutrals was similar except that it started from a non-negligible value and final values are relatively larger than in the case of ions. This indicates that neutrals come from multiple sources. It seems there is a nearly steady contribution from the entrance region, where ions are impinging and neutralized on the surface of capillary wall, in accordance with the picture that was used earlier to explain the non-zero starting value for the intensity of neutrals for polyethylene terephthalate capillaries. Neutrals can also be created from the guided ions later at the exit region, which explains the similarities in the time dependences. The decreasing part of the curves was fitted by exponential functions giving a characteristic deposited charge value for blocking effects. It was higher for larger tilt angles showing the blocking effect is faster for smaller angles. Our results support the scenario presented in a previous work that the blocking is caused by the repulsive field of charges accumulated inside the capillaries.

  4. 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

  5. Ranges, Reflection and Secondary Electron Emission for keV Hydrogen Ions Incident on Solid N2

    DEFF Research Database (Denmark)

    Børgesen, P.; Sørensen, H.; Hao-Ming, Chen

    1983-01-01

    Ranges were measured for 0.67–3.3 keV/amu hydrogen and deuterium ions in solid N2. Comparisons with similar results for N2-gas confirm the previously observed large phase effect in the stopping cross section. Measurements of the secondary electron emission coefficient for bulk solid N2 bombarded...... by 0.67–9 keV/amu ions also seem to support such a phase effect. It is argued that we may also extract information about the charge state of reflected projectiles....

  6. A study on irradiation damage of solid 5'-dTMP implanted by low energy N+ ion beam

    International Nuclear Information System (INIS)

    Shao Chunlin; Yu Zengliang

    1995-01-01

    The yields of inorganic phosphate and base released from 5'-dTMP irradiated by 30 keV N + ion beam were investigated. The fluence effects of these yields and the influence with 0.1 mol/L NaOH treatment on them were presented. It was shown that the alkali treatment would not only increase the yield of inorganic phosphate, but also damage and then split base released from the irradiated 5'-dTMP. When the irradiated samples were treated with 0.1 mol/L NaOH immediately, the yield of inorganic phosphate was increased by a factor of 1.7 and the concentration of base decreased to half of that in the sample's water solution. Furthermore, the yield of inorganic phosphate would increase by a factor of 2.8 after 40 min of alkali treatment. Irradiation effects of ion beam were mainly direct ones and had a higher value of G(P i ), greater than 0.44 molecule/100 eV

  7. Research into releasing inorganic phosphate and base from 5'-dTMP irradiated by a low energy ion beam

    International Nuclear Information System (INIS)

    Shao Chunlin; Yu Zengliang

    1994-01-01

    Research into radiation damage of nucleotide is an important area in radiation biology. In this paper, the yield of inorganic phosphate and base released from 5'-dTMP irradiated by a 30 keV N + ion beam was investigated in several aspects. The effect of particle fluence on yield and the influence of treatment with 0.1 N NaOH was deduced. By analysis, it is known that the alkali treatment not only increases the yield of inorganic phosphate, but also damages and splits the base released from irradiated 5'-dTMP. When the irradiated samples are treated by 0.1 N NaOH immediately, the yield of inorganic phosphate is increased by a factor of 1.7 and the concentration of base decreased to half of the original value. But the yield of inorganic phosphate could be increased by a factor of 2.8 after 40 min of alkali treatment. On the other hand, when 5'dTMP was irradiated by the ion beam, the G(Pi) obtained was above 0.44, higher than with γ-radiation. (Author)

  8. Guided transmission of 3 keV Ne sup 7 sup + ions through nanocapillaries in PET polymers. Dependence on the capillary diameter

    CERN Document Server

    Stolterfoht, N; Pesic, Z D; Hoffmann, V; Petrov, S; Fink, D; Sulik, B

    2003-01-01

    The outstanding progress in nanotechnology is accompanied by a continuous miniaturization of interfaces used in microelectronics and related fields. Particular attention has been paid to linear structures of mesoscopic dimensions, such as pores or capillaries. Experiments were started in which PET (Mylar) polymer foils of 10 lm thickness were irradiated by 400 MeV xenon. Capillaries with a diameter of a few hundreds nm in foil were obtained etching ion tracks using NaOH. (R.P.)

  9. Unusual surface and edge morphologies, sp2 to sp3 hybridized transformation and electronic damage after Ar+ ion irradiation of few-layer graphene surfaces.

    Science.gov (United States)

    Al-Harthi, Salim Hamood; Elzain, Mohammed; Al-Barwani, Muataz; Kora'a, Amal; Hysen, Thomas; Myint, Myo Tay Zar; Anantharaman, Maliemadom Ramaswamy

    2012-08-19

    Roughness and defects induced on few-layer graphene (FLG) irradiated by Ar+ ions at different energies were investigated using X-ray photoemission spectroscopy (XPS) and atomic force microscopy techniques. The results provide direct experimental evidence of ripple formation, sp2 to sp3 hybridized carbon transformation, electronic damage, Ar+ implantation, unusual defects and edge reconstructions in FLG, which depend on the irradiation energy. In addition, shadowing effects similar to those found in oblique-angle growth of thin films were seen. Reliable quantification of the transition from the sp2-bonding to sp3-hybridized state as a result of Ar+ ion irradiation is achieved from the deconvolution of the XPS C (1s) peak. Although the ion irradiation effect is demonstrated through the shape of the derivative of the Auger transition C KVV spectra, we show that the D parameter values obtained from these spectra which are normally used in the literature fail to account for the sp2 to sp3 hybridization transition. In contrast to what is known, it is revealed that using ion irradiation at large FLG sample tilt angles can lead to edge reconstructions. Furthermore, FLG irradiation by low energy of 0.25 keV can be a plausible way of peeling graphene layers without the need of Joule heating reported previously.

  10. 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

  11. Direct determination of a radiation-damage profile with atomic resolution in ion-irradiated platinum. MSC report No. 5030

    International Nuclear Information System (INIS)

    Pramanik, D.; Seidman, D.N.

    1983-05-01

    The field-ion microscope (FIM) technique has been employed to determine directly a radiation damage profile, with atomic resolution, in a platinum specimen which had been irradiated at 80 0 K with 20-keV Kr + ions to a fluence of 5 x 10 12 cm - 2 . It is shown that the microscopic spatial-vacancy distribution (radiation-damage profile) is directly related to the elastically-deposited-energy profile. The experimentally constructed radiation-damage profile is compared with a theoretical damage profile - calculated employing the TRIM Monte Carlo code - and excellent agreement is obtained between the two, thus demonstrating that it is possible to go directly from a microscopic spatial distribution of vacancies to a continuous radiation-damage profile

  12. Si(LMM) Auger electron emission from Si alloys by keV Ar/sup +/ ion bombardment, new effect and application

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, A; Kim, S; Imura, T; Iwami, M [Osaka Univ., Suita (Japan). Faculty of Engineering

    1979-09-01

    Si(LMM) Auger spectra excited by keV ion bombardment were studied in Si alloyed with several elements (Au, Cu, Pd, Ni, C, and H). The spectra differed completely from those of pure Si. The main characteristics are (1) the spectra are composed of two well-separated peaks (88 and 92 eV) called the atomic-like peak (88 eV) and the bulk-like peak (92 eV); and (2) the atomic-like peak is enhanced with respect to the bulk-like peak, and this enhancement becomes more obvious as the concentration of partner elements of the alloys are increased. The possible application of the present phenomena is proposed as a technique for detecting the homogeneity of Si alloy films in the three-dimensional sense - as an example, the three-dimensional distribution of hydrogen in hydrogenated amorphous silicon (a-Si-H).

  13. Electron capture by He2+ ions in collisions with H and H2 at impact energies below 10 keV

    International Nuclear Information System (INIS)

    Nutt, W.L.; McCullough, R.W.; Brady, K.; Shah, M.B.; Gilbody, H.B.

    1978-01-01

    Total cross sections for the process He 2+ + H(1s) → He + (Σn, 1) + H + involving capture into all final bound states of He + have been determined for 3 He 2+ ions in the range 1.5-9.0 keV using a furnace-target technique previously employed for similar measurements at higher impact energies. Measured cross sections are considerably smaller than those measured previously by Fite et al (Proc. R.Soc.; A268:527 (1962)) and are in better accord with recent theoretical estimates. A likely explanation for the discrepancy is given in terms of the corresponding cross sections for electron capture in He 2+ -H 2 collisions which have also been determined. (author)

  14. 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.

  15. Atom and carrier depth distributions for 300 keV arsenic channeled in the of silicon as a function of alignment angle and ion fluence

    International Nuclear Information System (INIS)

    Wilson, R.G.

    1980-01-01

    Depth distributions of As atoms measured by SIMS, and of associated carriers measured by differential C-V, both give a measured most probable channeling range Rsub(c) of 3.35 to 3.40 μm for 300 keV As ions implanted in the of Si, aligned within approximately 0.05 deg (proper or axial channeling). The As ion fluences used were 3.0 x 10 13 and 1.0 x 10 14 , and 1.5 x 10 12 cm -2 , for the SIMS and C-V, respectively, and the lowest atom and carrier densities measured in the profiles were 1 x 10 15 and 1 x 10 14 cm -3 , respectively. The maximum or saturated As density measured at Rsub(c) was approximately 1.5 x 10 16 cm -3 . The depth distribution for 0.50 deg misalignment from the differed only slightly, probably within the experimental measurement reproducibility, and the Rsub(c) was still approximately 3.4 μm. Atom and carrier depth distributions are also shown for misalignment angles of 1.0 and 2.0 deg from the of Si and are significantly degraded. Comparison of the SIMS profiles shows that channeling has saturated by the time an ion fluence of 3 x 10 13 cm -2 is reached. No significant redistribution of channeled As atoms occurs upon annealing at 800 0 C for 30 min. (author)

  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. Growth stress buildup in ion beam sputtered Mo thin films and comparative study of stress relaxation upon thermal annealing or ion irradiation

    International Nuclear Information System (INIS)

    Debelle, A.; Abadias, G.; Michel, A.; Jaouen, C.; Pelosin, V.

    2007-01-01

    In an effort to address the understanding of the origin of growth stress in thin films deposited under very energetic conditions, the authors investigated the stress state and microstructure of Mo thin films grown by ion beam sputtering (IBS) as well as the stress relaxation processes taking place during subsequent thermal annealing or ion irradiation. Different sets of samples were grown by varying the IBS deposition parameters, namely, the energy E 0 and the flux j of the primary ion beam, the target-to-sputtering gas mass ratio M 1 /M 2 as well as film thickness. The strain-stress state was determined by x-ray diffraction using the sin 2 ψ method and data analyzed using an original stress model which enabled them to correlate information at macroscopic (in terms of stress) and microscopic (in terms of defect concentration) levels. Results indicate that these refractory metallic thin films are characterized by a high compressive growth stress (-2.6 to -3.8 GPa), resulting from the creation of a large concentration (up to ∼1.4%) of point or cluster defects, due to the atomic peening mechanism. The M 1 /M 2 mass ratio enables tuning efficiently the mean deposited energy of the condensing atoms; thus, it appears to be the more relevant deposition parameter that allows modifying both the microstructure and the stress level in a significant way. The growth stress comes out to be highly unstable. It can be easily relaxed either by postgrowth thermal annealing or ion irradiation in the hundred keV range at very low dose [<0.1 dpa (displacement per atom)]. It is shown that thermal annealing induces deleterious effects such as oxidation of the film surface, decrease of the film density, and in some cases adhesion loss at the film/substrate interface, while ion irradiation allows controlling the stress level without generating any macroscopic damage

  19. Calculated energy distributions for light 0.25--18-keV ions scattered from solid surfaces

    International Nuclear Information System (INIS)

    Robinson, J.E.; Harms, A.A.; Karapetsas, S.K.

    1975-01-01

    Scattered energy distributions are calculated for light ions incident on Nb and Mo surfaces of interest for controlled nulcear fusion reactors. The scattered energy is found to vary as a function of the reflection coefficient between a multiple-collision limit at low energies and a single-collision Rutherford scattering limit at high energies. High-energy peaking of the scattered particle distributions is also found for low incident energies

  20. Characterisation of PEEK, PET and PI implanted with 80 keV Fe+ ions to high fluencies

    Czech Academy of Sciences Publication Activity Database

    Macková, Anna; Malinský, Petr; Mikšová, Romana; Hnatowicz, Vladimír; Khaibullin, R. I.; Slepička, P.; Švorčík, V.

    2014-01-01

    Roč. 331, JUL (2014), s. 176-181 ISSN 0168-583X R&D Projects: GA ČR GA106/09/0125; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : Fe ion implantation * polymers * depth profiles * RBS * TEM * UV Vis Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.124, year: 2014

  1. 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.

  2. Radiation-induced segregation at grain boundaries in AL-6XN stainless steels irradiated by hydrogen ions

    Science.gov (United States)

    Long, Yunxiang; Zheng, Zhongcheng; Guo, Liping; Zhang, Weiping; Shen, Zhenyu; Tang, Rui

    2018-04-01

    The effect of high concentration of hydrogen on the segregation of radiation-induced segregation (RIS) in AL-6XN stainless steels has been investigated by transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy. Specimens were irradiated with 100 keV H2+ ions from 1 dpa to 5 dpa at 380 °C to investigated the dose dependence of grain boundary RIS. A specimen was irradiated to 5 dpa at 290 °C to study the effect of irradiation temperature. The trends of Cr depletion and Ni enrichment with irradiation dose is similar to that of other austenitic steels reported in the literatures, but the higher concentration of hydrogen made the RIS profile wider. An abnormal phenomenon that the degree of RIS increased with decreasing irradiation temperature was found, indicating that with the retention of hydrogen in the steels, temperature dependence of RIS is dominated by the quantity of retained hydrogen, rather than by thermal segregation processes.

  3. 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

  4. 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.

  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. 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.

  7. 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.

  8. Ion desorption from solid surfaces under slow (KeV) and fast (MeV) ion sputtering. Influence of the charge state and of the incidence angle on the input channel

    International Nuclear Information System (INIS)

    Joret, H.

    1990-06-01

    Solid surfaces of organic and inorganic materials have been bombarded by fast heavy ions (several MeV). It is shown that the charge state of the projectile has a strong influence on the atomic and molecular ion desorption yield. Experimental studies proved that molecular ions can be emitted intact from deep layers underneath the surface (volume emission) with the existence of a crater emission. On the other hand light ions like H(+), H(+)-2, H(+)-3 are emitted from the surface of the solid in a time around 10 -16 second. The H(+) depends on the incident charge state g-i. When using slow ions (keV) the same dependence was observed for the first time and compared to the fast ion results. The equilibrum charge state of fast ions passing through solids was measured. The influence of the angle of incidence was investigated. Langmuir-Blodgett films of fatty acid were used. A geometrical model is developed for the 50 angstroms layer [fr

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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)

  15. 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

  16. Studies on watermelon somatic cell mutant of resistance to fusaric acid (FA) by low energy Ar+ ion beam irradiation

    International Nuclear Information System (INIS)

    Wang Haobo; Gu Yunhong; Cheng Guowang; Yu Zengliang

    2003-01-01

    Three kinds of watermelon seeds irradiated by Ar + ion beam (25 keV, 6.24 x 10 16 ions/cm 2 ) were inoculated in MS medium with 15 mg/L FA. Cotyledons from the sterile seedling as explants were inoculated in MS +BA 2.0 mg/L + FA 15 mg/L. And the adventitious shoots of resistance to FA were cultured in MS + NAA 0.2 mg/L + FA 15 mg/L. The results showed that both the irradiation of Ar + and FA affected the germination rate and seedling of watermelon line 3-27 and YH-5, and the joint effect of Ar + and FA showed an enhanced restraint. The adventitious shoot and rootage induction rate from the seeds irradiated by Ar + were respectively bigger than the unirradiated seeds in 3-27 and YH-5. The increasing ranges were different between two watermelon lines and between the shoot and rootage induction rates

  17. A Preliminary Study of the Application of a Model Animal-Caenorhabidity elegans' Exposure to a Low-Energy Ion Irradiation System

    International Nuclear Information System (INIS)

    Liu Xuelan; Cai Kezhou; Feng Huiyun; Xu An; Yuan Hang; Yu Zengliang

    2007-01-01

    Because of the lack of suitable animal models adapted to high vacuum stress in the low-energy ion implantation system, the bio-effects ion irradiation with an energy less than 50 keV on multi-cellular animal individuals have never been investigated so far. The nematode Caenorhabditis elegans has proved to be an excellent animal model used for the study of a broad spectrum of biological issues. The purpose of this work was to investigate the viability of this animal under ion irradiation. We studied the protection effects of glycerol and trehalose on the enhancement of nematodes' ability to bear the vacuum stress. The results showed that the survival of the nematodes was enhanced remarkably under long and slow desiccation, even without glycerol and trehalose. 15% glycerol showed a better anti-vacuum stress effect on the nematodes than trehalose did under short-time desiccation. Low-temperature pre-treatment or post-treatment of the samples had no obvious effect on the survival scored after argon ion irradiation. Moreover, little effect was induced by 15% glycerol- and vacuum-exposure on germ cell apoptosis, compared to the untreated control sample. It issuggested that such treatment would provide relatively low background for genotoxic evaluations with ion irradiation

  18. 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.

  19. 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.

  20. 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)

  1. 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

  2. Kinetic energies of charged fragments resulting from multifragmentation and asymmetric fission of the C60 molecule in collisions with monocharged ions (2-130 keV)

    International Nuclear Information System (INIS)

    Rentenier, A; Bordenave-Montesquieu, D; Moretto-Capelle, P; Bordenave-Montesquieu, A

    2003-01-01

    Multifragmentation and asymmetric fission (AF) of the C 60 molecule induced by H + , H 2 + , H 3 + and He + ions at medium collision energies (2-130 keV) are considered. Momenta and kinetic energies of C n + fragment ions (n = 1- 12) are deduced from an analysis of time-of-flight spectra. In multifragmentation processes, momenta are found to be approximately constant when n > 2, a behaviour which explains that the most probable kinetic energy, as well as the width of the kinetic energy distributions, is found to be inversely proportional to the fragment size n; both momenta and kinetic energies are independent of the velocity and nature of the projectile, and hence of the energy deposit. A specific study of the AF shows that the kinetic energies of C 2 + , C 4 + and C 6 + fragments are also independent of the collision velocity and projectile species; a quantitative agreement is found with values deduced from kinetic energy release measurements by another group in electron impact experiments, and the observed decrease when the mass of the light fragment increases is also reproduced. A quantitative comparison of AF and multifragmentation for the n = 2, 4 and 6 fragment ions shows that kinetic energies in AF exceed that in multifragmentation, a result which explains the oscillations observed when momenta or kinetic energies of fragments are plotted against the n-value. The AF yield is also found to scale with the energy deposit in the collision velocity range extending below the velocity at the maximum of the electronic stopping power; except for protons, it remains negligible with respect to multifragmentation as soon as the total energy deposit exceeds about 100 eV

  3. 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

  4. Solar Cycle dependence of 5-55 keV Cassini/INCA energetic neutral atom (ENA) images of the Heliosheath and in situ Voyager/LECP ion measurements

    Science.gov (United States)

    Krimigis, S. M.; Dialynas, K.; Mitchell, D. G.; Decker, R. B.; Roelof, E. C.

    2015-12-01

    The heliosheath has been identified as the most probable source of ENAs that INCA detects but its variability due to solar activity throughout the solar cycle (SC) has not been resolved to date. We show all-sky, 5-55 keV ENA H maps from the year 2003 to 2014 and compare the solar cycle variation of the ENAs in both the heliospheric nose (upstream) and anti-nose (downstream) directions with the > 30 keV ions measured within the heliosheath by the Low Energy Charged Particle (LECP) detector on Voyagers 1, 2 (V1, V2) where we measure protons in overlapping energy bands ~30-55 keV. We find that a) Toward the anti-nose direction the ENA-H intensities decline during SC23, i.e. after 2003 ENA intensities decreased by ~ x2 at all energies by the end of year 2011, ~1 year after the observed minimum in solar activity; b) This ENA decrease (5.2-55 keV) during 2009-2011 is consistent with the concurrent intensity decrease of the > 30 keV ions (by a factor of 2-3) observed in situ by V1 and V2 in the heliosheath; c) Toward the nose direction, minimum intensities in both INCA ENAs and the V2 ions at E > 28 keV occur during the year 2013, with a subsequent recovery from 2014 to date (by a factor of ~2 in the > 35 keV ENA data). These quantitative correlations between the decreases of INCA ENAs (in both the heliospheric nose and anti-nose directions) and the in situ V1 and V2 ion measurements (separated by > 130 AU) during the declining phase of SC23, along with their concurrent jointly shared recoveries at the onset of SC24, imply that: 1) the 5-55 keV ENAs are produced in the heliosheath (because their transit times over 100 AU are less than a few months at energies > 40 keV), thus proving that our ENA observations can provide the ground truth for constructing comprehensive global heliosphere models; 2) the global heliosheath responds promptly (within ~1-1.5 yrs) to outward-propagating solar wind changes throughout the solar cycle.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Enhancement of optical absorption of Si (100) surfaces by low energy N+ ion beam irradiation

    Science.gov (United States)

    Bhowmik, Dipak; Karmakar, Prasanta

    2018-05-01

    The increase of optical absorption efficiency of Si (100) surface by 7 keV and 8 keV N+ ions bombardment has been reported here. A periodic ripple pattern on surface has been observed as well as silicon nitride is formed at the ion impact zones by these low energy N+ ion bombardment [P. Karmakar et al., J. Appl. Phys. 120, 025301 (2016)]. The light absorption efficiency increases due to the presence of silicon nitride compound as well as surface nanopatterns. The Atomic Force Microscopy (AFM) study shows the formation of periodic ripple pattern and increase of surface roughness with N+ ion energy. The enhancement of optical absorption by the ion bombarded Si, compared to the bare Si have been measured by UV - visible spectrophotometer.

  10. 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.

  11. Effects of H-implantation energy on the optical stability of implanted usher films under photo-irradiation

    International Nuclear Information System (INIS)

    Awazu, K.; Yasui, H.; Kasamori, M.; Ichikawa, T.; Funada, Y.; Iwaki, M.

    1999-01-01

    A study has been made on the improvement of the optical stability of urushi films under optical irradiation using ion implantation. Ion implantation of hydrogen ions in urushi films was performed with a dose of 10 15 ions/cm 2 at ion energies ranging from 0.2 to 150 keV at room temperature. The photo-irradiation onto the urushi films was carried out at irradiation energies ranging from 40 to 400 MJ/m 2 . H-implantation onto urushi films is useful for improving the optical stability under photo-irradiation when the implantation energy is larger than 60 keV

  12. 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 ion chambers as a function of the applied voltage and the air kerma rate have been analysed to determine the contribution of the initial and general ion recombination. The k sat values for large-volume ionization chambers obtained by considering the general ion recombination as predominant (Almond's approach) are in disagreement with the results obtained using methods that consider both initial and general ion-recombination contributions (Niatel's approach). Such disagreement can reach 0.7% when high currents are measured for a high-activity source calibration in terms of reference air kerma rate. In this study a new 'two-voltage' method, independent of the voltage ratio given by a dosimetry system, is proposed for practical dosimetry of continuous x-and gamma-radiation beams. In the case where the Almond approach is utilized, the voltage ratio V 1 /V 2 should be less than 2 instead of Almond's limit of V 1 /V 2 <5. (Author)

  13. 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.)

  14. Similarity between the effects of carbon-ion irradiation and X-irradiation on the development of rat brain

    International Nuclear Information System (INIS)

    Inouye, Minoru; Hayasaka, Shizu; Murata, Yoshiharu; Takahashi, Sentaro; Kubota, Yoshihisa

    2000-01-01

    The effects of carbon-ion irradiation and X-irradiation on the development of rat brain were compared. Twenty pregnant rats were injected with bromodeoxyuridine (BrdU) at 9 pm on day 18 pregnancy and divided into five groups. Three hours after injection (day 19.0) one group was exposed to 290 MeV/u carbon-ion radiation by a single dose of 1.5 Gy. Other groups were exposed to X-radiation by 1.5, 2.0 or 2.5 Gy, or sham-treated, respectively. Fetuses were removed from one dam in each group 8 h after exposure and examined histologically. Extensive cell death was observed in the brain mantle from the irradiated groups. The cell death after 1.5 Gy carbon-ion irradiation was remarkably more extensive than that after 1.5 Gy X-irradiation, but comparable to that after 2.0 Gy or 2.5 Gy X-irradiation. The remaining rats were allowed to give birth and the offspring were sacrificed at 6 weeks of age. All of the irradiated offspring manifested microcephaly. The size of the brain mantle exposed to 1.5 Gy carbon-ion radiation was significantly smaller than that exposed to 1.5 Gy X-radiation and larger than that exposed to 2.5 Gy X-radiation. A histological examination of the cerebral cortex revealed that cortical layers II-IV were malformed. The defect by 1.5 Gy carbon-ion irradiation was more severe than that by the same dose of X-irradiation. Although the BrdU-incorporated neurons were greatly reduced in number in all irradiated groups, these cells reached the superficial area of the cortex. These findings indicated that the effects of both carbon-ion irradiation and X-irradiation on the development of rat brain are similar in character, and the effect of 1.5 Gy carbon-ion irradiation compares to that of 2.0-2.5 Gy X-irradiation. (author)

  15. Characterization of ion-irradiation-induced nanodot structures on InP surfaces by atom probe tomography.

    Science.gov (United States)

    Gnaser, Hubert; Radny, Tobias

    2015-12-01

    Surfaces of InP were bombarded by 1.9 keV Ar(+) ions under normal incidence. The total accumulated ion fluence the samples were exposed to was varied from 1 × 10(17) cm(-2) to 3 × 10(18)cm(-2) and ion flux densities f of (0.4-2) × 10(14) cm(-2) s(-1) were used. Nanodot structures were found to evolve on the surface from these ion irradiations, their dimensions however, depend on the specific bombardment conditions. The resulting surface morphology was examined by atomic force microscopy (AFM). As a function of ion fluence, the mean radius, height, and spacing of the dots can be fitted by power-law dependences. In order to determine possible local compositional changes in these nanostructures induced by ion impact, selected samples were prepared for atom probe tomography (APT). The results indicate that by APT the composition of individual InP nanodots evolving under ion bombardment could be examined with atomic spatial resolution. At the InP surface, the values of the In/P concentration ratio are distinctly higher over a distance of ~1 nm and amount to 1.3-1.8. However, several aspects critical for the analyses were identified: (i) because of the small dimensions of these nanostructures a successful tip preparation proved very challenging. (ii) The elemental compositions obtained from APT were found to be influenced pronouncedly by the laser pulse energy; typically, low energies result in the correct stoichiometry whereas high ones lead to an inhomogeneous evaporation from the tips and deviations from the nominal composition. (iii) Depending again on the laser energy, a prolific emission of Pn cluster ions was observed, with n ≤ 11. Copyright © 2015. Published by Elsevier B.V.

  16. Heavy ion irradiation effects of polymer film on absorption of light

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Noboru; Seguchi, Tadao [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Arakawa, Tetsuhito

    1997-03-01

    Ion irradiation effects on the absorption of light for three types of polymer films; polyethylene-terephthalate (PET), polyethylene-naphthalate (PEN), and polyether-ether-ketone (PEEK) were investigated by irradiation of heavy ions with Ni{sup 4+}(15MeV), O{sup 6+}(160MeV), and Ar{sup 8+}(175MeV), and compared with electron beams(EB) irradiation. The change of absorption at 400nm by a photometer was almost proportional to total dose for ions and EB. The absorption per absorbed dose was much high in Ni{sup 4+}, but rather small in O{sup 6+} and Ar{sup 8+} irradiation, and the absorption by EB irradiation was accelerated by the temperature of polymer film during irradiation. The beam heating of materials during ion irradiation was assumed, especially for Ni ion irradiation. The heavy ion irradiation effect of polymers was thought to be much affected by the ion beam heating than the linear energy transfer(LET) of radiation source. (author)

  17. In-situ transmission electron microscopy study of ion-irradiated copper : comparison of the temperature dependence of cascade collapse in FCC- and BCC- metals.

    Energy Technology Data Exchange (ETDEWEB)

    Daulton, T. L.

    1998-10-23

    The kinetics which drive cascade formation and subsequent collapse into point-defect clusters is investigated by analyzing the microstructure produced in situ by low fluence 100 keV Kr ion irradiations of fcc-Cu over a wide temperature range (18-873 K). The yield of collapsed point-defect clusters is demonstrated unequivocally to be temperature dependent, remaining approximately constant up to lattice temperatures of 573 K and then abruptly decreasing with increasing temperature. This drop in yield is not caused by defect loss during or following ion irradiation. This temperature dependence can be explained by a thermal spike effect. These in-situ yield measurements are compared to previous ex-situ yield measurements in fcc-Ni and bcc-Mo.

  18. In situ transmission electron microscopy study of ion-irradiated copper: comparison of the temperature dependence of cascade collapse in fcc- and bcc-metals

    International Nuclear Information System (INIS)

    Daulton, T.L.; Kirk, M.A.; Rehn, L.E.

    2000-01-01

    The kinetics which drive cascade formation and subsequent collapse into point-defect clusters are investigated by analyzing the microstructure produced in situ by low fluence 100 keV Kr ion irradiations of fcc-Cu over a wide temperature range (18-873 K). The yield of collapsed point-defect clusters is demonstrated unequivocally to be temperature dependent, remaining approximately constant up to lattice temperatures of 573 K and then abruptly decreasing with increasing temperature. This drop in yield is not caused by defect loss during or following ion irradiation. In addition, this temperature dependence can be explained by a thermal spike effect. These in situ yield measurements are compared to previous ex situ yield measurements in fcc-Ni and bcc-Mo

  19. 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 ...

  20. Improvement of the mechanical and frictional properties of steels by continuous and pulsed ion irradiation

    International Nuclear Information System (INIS)

    Romanov, I.G.

    1992-01-01

    Effect of continuous and powerful pulsed ion beams (PIB) on structural, mechanical, tribological properties and surface morphology of steels were investigated. The results obtained demonstrate the significant influence of ion irradiation type on microhardness, friction coefficient, wear resistance and surface roughness characteristics. Friction coefficient variation in irradiated steels is interpreted within the framework of an adhesion-deformation model

  1. Valency stabilization of polyvalent ions during gamma irradiation of their aqueous solutions by sacrificial protection. I- Valency stabilization of Fe (II) ions by sulphate ions

    Energy Technology Data Exchange (ETDEWEB)

    Barakat, M F [Nuclear chemistry department, hot lab. center, Atomic Energy Authority, Cairo, (Egypt); Abdel-Hamid, M M [Arab Atomic Energy Agency, P.O. Box 402 El-Manzah-1004 Tunis, (Tunisia)

    1995-10-01

    Polyvalent ions are very sensitive to gamma irradiation in aqueous solutions. The present work is a part of a more comprehensive study dealing with the stabilization or protection of certain oxidation states of some polyvalent ions during their gamma irradiation in aqueous systems. The behaviour of aqueous acidic Fe (II) solutions during gamma irradiation, in presence the prevailing protection mechanism. The conditions and stabilization limits in the studied case has been found out. 9 figs.

  2. Valency stabilization of polyvalent ions during gamma irradiation of their aqueous solutions by sacrificial protection. I- Valency stabilization of Fe (II) ions by sulphate ions

    International Nuclear Information System (INIS)

    Barakat, M.F.; Abdel-Hamid, M.M.

    1995-01-01

    Polyvalent ions are very sensitive to gamma irradiation in aqueous solutions. The present work is a part of a more comprehensive study dealing with the stabilization or protection of certain oxidation states of some polyvalent ions during their gamma irradiation in aqueous systems. The behaviour of aqueous acidic Fe (II) solutions during gamma irradiation, in presence the prevailing protection mechanism. The conditions and stabilization limits in the studied case has been found out. 9 figs

  3. Microstructural and microchemical evolution in vanadium alloys by heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sekimura, Naoto; Kakiuchi, Hironori; Shirao, Yasuyuki; Iwai, Takeo [Tokyo Univ. (Japan)

    1996-10-01

    Microstructural and microchemical evolution in vanadium alloys were investigated using heavy ion irradiation. No cavities were observed in V-5Cr-5Ti alloys irradiated to 30 dpa at 520 and 600degC. Energy dispersive X-ray spectroscopy analyses showed that Ti peaks around grain boundaries. Segregation of Cr atoms was not clearly detected. Co-implanted helium was also found to enhance dislocation evolution in V-5Cr-5Ti. High density of matrix cavities were observed in V-5Fe alloys irradiated with dual ions, whereas cavities were formed only around grain boundaries in single ion irradiated V-5Fe. (author)

  4. Helium ion irradiated polyamidoimide films: a FT-IR and Raman follow-up

    International Nuclear Information System (INIS)

    Merhari, L.; Belorgeot, C.; Quintard, P.

    1994-01-01

    The evolution of polyamidoimide (PAI) at a molecular level has been studied by infrared and Raman spectroscopy after several He + ion irradiations. The infrared investigation made it possible to study the appearance of CO 2 and HCN molecules and, for example, to correlate CO 2 with C-O vanishing bands during He + ion irradiation. Preliminary Raman spectroscopy results confirmed a graphite-like structure for strongly irradiated PAI. In situ spectroscopic measurements versus fluence during irradiation with other ions are expected to give further information about the polymer structure evolution. (6 figures, 10 references) (UK)

  5. Freely migrating defects in ion-irradiated Cu3Au

    International Nuclear Information System (INIS)

    Wei, L.C.; Lang, E.; Flynn, C.P.; Averback, R.S.

    1999-01-01

    The efficiency of producing freely migrating vacancy defects in irradiated Cu 3 Au was examined using electrical resistivity measurements of radiation-induced ordering on highly perfect single-crystal films. Relative efficiencies for He, Ne, and Ar bombardments at different ion energy and specimen temperature were obtained. The ratio of the efficiencies of 0.6 MeV Ne to He increased with temperature from ∼0.25 at 340 K to a saturation value of ∼0.40 at 520 K. For Ar and He, the ratio increased from ∼0.11 at 360 K to ∼0.18 at 540 K. Estimates indicate that about half of all defects created in cascades are freely migrating. copyright 1999 American Institute of Physics

  6. Ion-irradiation studies of cascade damage in metals

    International Nuclear Information System (INIS)

    Averback, R.S.

    1982-03-01

    Ion-irradiation studies of the fundamental aspects of cascade damage in metals are reviewed. The emphasis of these studies has been the determination of the primary state of damage (i.e. the arrangement of atoms in the cascade region prior to thermal migration of defects). Progress has been made towards understanding the damage function (i.e. the number of Frenkel pairs produced as a function of primary recoil atom energy), the spatial configuration of vacancies and interstitials in the cascade and the cascade-induced mixing of atoms. It is concluded for these studies that the agitation of the lattice in the vicinity of energetic displacement cascades stimulates the defect motion and that such thermal spike motion induces recombination and clustering of Frenkel defects. 9 figures

  7. Highly sensitive urea sensing with ion-irradiated polymer foils

    International Nuclear Information System (INIS)

    Fink, Dietmar; Muñoz Hernandez, Gerardo; Alfonta, Lital

    2012-01-01

    Recently we prepared urea-sensors by attaching urease to the inner walls of etched ion tracks within thin polymer foil. Here, alternative track-based sensor configurations are examined where the enzyme remained in solution. The conductivities of systems consisting of two parallel irradiated polymer foils and confining different urea/urease mixtures in between were examined. The correlations between conductivity and urea concentration differed strongly for foils with unetched and etched tracks, which points at different sensing mechanisms – tentatively attributed to the adsorption of enzymatic reaction products on the latent track entrances and to the enhanced conductivity of reaction product-filled etched tracks, respectively. All examined systems enable in principle, urea sensing. They point at the possibility of sensor cascade construction for more sensitive or selective sensor systems.

  8. Effects of pulsed dual-ion irradiation of microstructural development

    International Nuclear Information System (INIS)

    Packan, N.H.

    1981-01-01

    The effect of pulsed irradiation on the development of microstructure during Ni ion bombardment has been investigated in a simple austenitic alloy similar to type 316 stainless steel. Bombardment conditions were 10 dpa, 940 K, pulsing with equal on/off times of either 0.5 or 60 s, and the addition of 20 appM He/dpa to some specimens either by room temperature preimplantation or by dual-beam coimplantation. Particular care was taken to minimize thermal pulses from beam heating (to 0 C). The results show that pulsing has a subtle influence, and the effects on specific cavity parameters are complex. Pulsing produced a small increase in swelling in the helium-free case, but a slight decrease for helium-implanted specimens, and it seems to have counteracted the usual stimulative effects of helium on cavity nucleation

  9. Surface damage on 6H–SiC by highly-charged Xeq+ ions irradiation

    International Nuclear Information System (INIS)

    Zhang, L.Q.; Zhang, C.H.; Han, L.H.; Xu, C.L.; Li, J.J.; Yang, Y.T.; Song, Y.; Gou, J.; Li, J.Y.; Ma, Y.Z.

    2014-01-01

    Surface damage on 6H–SiC irradiated by highly-charged Xe q+ (q = 18, 26) ions to different fluences in two geometries was studied by means of AFM, Raman scattering spectroscopy and FTIR spectrometry. The FTIR spectra analysis shows that for Xe 26+ ions irradiation at normal incidence, a deep reflection dip appears at about 930 cm −1 . Moreover, the reflectance on top of reststrahlen band decreases as the ion fluence increases, and the reflectance at tilted incidence is larger than that at normal incidence. The Raman scattering spectra reveal that for Xe 26+ ions at normal incidence, surface reconstruction occurs and amorphous stoichiometric SiC and Si–Si and C–C bonds are generated and original Si–C vibrational mode disappears. And the intensity of scattering peaks decreases with increasing dose. The AFM measurement shows that the surface swells after irradiation. With increasing ion fluence, the step height between the irradiated and the unirradiated region increases for Xe 18+ ions irradiation; while for Xe 26+ ions irradiation, the step height first increases and then decreases with increasing ion fluence. Moreover, the step height at normal incidence is higher than that at tilted incidence by the irradiation with Xe 18+ to the same ion fluence. A good agreement between the results from the three methods is found

  10. 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.

  11. Recombination and photosensitivity centres in boron nitride irradiated with ions

    International Nuclear Information System (INIS)

    Kabyshev, A.; Konusov, F.; Lopatin, V.

    2001-01-01

    The physical-chemical processes, taking place during the irradiation of dielectrics with ions distort the electron structure of the compounds and generate additional localise state in the forbidden zone (FZ). Consequently, the semiconductor layer with the specific surface density of σ ≥ 10 -10 S/ forms on the surface of the dielectric. In addition to his, the high concentration of the radiation-induced defects changes the optical and photoelectric properties of the materials and also the energy characteristics. Analysis of the photoelectric properties indicates that the recombination processes take part in electric transport. These processes restricted the increase of the photosensitivity and changing the kinetics of relaxation of photo conductivity (σ hv ). The practical application of the boron nitride (BN) the in the thermonuclear systems (for example, Ref. 7), stimulates research into the reasons for the deceleration of its properties under the effect of radiation of various types. The conductivity of non-irradiated boron nitride is of the electron-hole nature with a large fraction of the activation component in exchange of the charge carriers between the levels of the defects and the forbidden zones. On the basis of the correlation of the energy and kinetic parameters of luminescence and , the authors of Ref. 8 constructed a model of electron transfers accompanying the electric transport of the boron nitride. In addition to ion-thermal modification, the conductivity of boron nitride is also of the electron-hole nature and is accompanied by luminescence. Examination of the characteristics of luminescence may be useful for obtaining more information on the transport mechanism. In this work, in order to clarify the main parameters of the forbidden band, detailed investigations were carried out into the spectrum of the electronic states of radiation defects which determine the photoelectric and luminescence properties of the modified boron nitride. The

  12. Accumulation and recovery of defects in ion-irradiated nanocrystalline gold

    Energy Technology Data Exchange (ETDEWEB)

    Chimi, Y. E-mail: chimi@popsvr.tokai.jaeri.go.jp; Iwase, A.; Ishikawa, N.; Kobiyama, M.; Inami, T.; Okuda, S

    2001-09-01

    Effects of 60 MeV {sup 12}C ion irradiation on nanocrystalline gold (nano-Au) are studied. The experimental results show that the irradiation-produced defects in nano-Au are thermally unstable because of the existence of a large volume fraction of grain boundaries. This suggests a possibility of the use of nanocrystalline materials as irradiation-resistant materials.

  13. 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.

  14. Transmission sputtering of gold thin-films by low-energy (< 1 keV) xenon ions: I. The system and the measurement

    International Nuclear Information System (INIS)

    Ayrault, G.; Seidman, D.N.

    1978-01-01

    A novel system for direct measurement of the transmission sputtering yields of ion-irradiated thin films is described. The system was specifically designed for the study of the transmission sputtering caused by low energy ( 0 A thick) which was mounted in a JEM 200 transmission electron-microscope holder. The temperature of the specimen could be varied between approx. 25 and 300 K employing a continuous-transfer liquid-helium cryostat. The particles (atoms or ions) ejected from the unirradiated surface of the gold thin-film were detected by two channetron electron-multiplier arrays in the Chevron configuration; the Chevron detector was able to detect individual transmission sputtered particles when operated in the saturated mode. To further enhance resolution the electron cascades, produced by the CEMA, were amplified and shaped electronically into uniform square pulses. The shaped signals were detected with an Ithaco 391A lock-in amplifier (LIA). With the aid of a ratiometer feature in the LIA we were able to measure directly the ratio of the transmission sputtered-current (I/sub t/) to the incident ion-current (I/sub b/); for I/sub b/ = μA cm -2 a ratio of I/sub t//I/sub b/ as small as 1 x 10 -9 was measured. A detailed discussion of the calibration procedure and the experimental errors, involved in this technique, are also presented. 45 references

  15. Comparison of swelling for structural materials on neutron and ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, B.A.

    1986-03-01

    The swelling of V-base alloys, Type 316 stainless steel, Fe-25Ni-15Cr alloys, ferritic steels, Cu, Ni, Nb-1% Zr, and Mo on neutron irradiation is compared with the swelling for these materials on ion irradiation. The results of this comparison show that utilization of the ion-irradiation technique provides for a discriminative assessment of the potential for swelling of candidate materials for fusion reactors.

  16. Secondary particle tracks generated by ion beam irradiation

    Science.gov (United States)

    García, Gustavo

    2015-05-01

    The Low Energy Particle Track Simulation (LEPTS) procedure is a powerful complementary tool to include the effect of low energy electrons and positrons in medical applications of radiation. In particular, for ion-beam cancer treatments provides a detailed description of the role of the secondary electrons abundantly generated around the Bragg peak as well as the possibility of using transmuted positron emitters (C11, O15) as a complement for ion-beam dosimetry. In this study we present interaction probability data derived from IAM-SCAR corrective factors for liquid environments. Using these data, single electron and positron tracks in liquid water and pyrimidine have been simulated providing information about energy deposition as well as the number and type of interactions taking place in any selected ``nanovolume'' of the irradiated area. In collaboration with Francisco Blanco, Universidad Complutense de Madrid; Antonio Mu noz, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas and Diogo Almeida, Filipe Ferreira da Silva, Paulo Lim ao-Vieira, Universidade Nova de Lisboa. Supported by the Spanish and Portuguese governments.

  17. 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.

  18. The irradiation hardening of Ni-Mo-Cr and Ni-W-Cr alloy under Xe26+ ion irradiation

    Science.gov (United States)

    Chen, Huaican; Hai, Yang; Liu, Renduo; Jiang, Li; Ye, Xiang-xi; Li, Jianjian; Xue, Wandong; Wang, Wanxia; Tang, Ming; Yan, Long; Yin, Wen; Zhou, Xingtai

    2018-04-01

    The irradiation hardening of Ni-Mo-Cr and Ni-W-Cr alloy was investigated. 7 MeV Xe26+ ion irradiation was performed at room temperature and 650 °C with peak damage dose from 0.05 to 10 dpa. With the increase of damage dose, the hardness of Ni-Mo-Cr and Ni-W-Cr alloy increases, and reaches saturation at damage dose ≥1 dpa. Moreover, the damage dose dependence of hardness in both alloys can be described by the Makin and Minter's equation, where the effective critical volume of obstacles can be used to represent irradiation hardening resistance of the alloys. Our results also show that Ni-W-Cr alloy has better irradiation hardening resistance than Ni-Mo-Cr alloy. This is ascribed to the fact that the W, instead of Mo in the alloy, can suppress the formation of defects under ion irradiation.

  19. Ion Irradiation Damage in Zirconate and Titanate Ceramics for Pu Disposition

    International Nuclear Information System (INIS)

    Stewart, Martin W.; Begg, Bruce D.; Finnie, K.; Colella, Michael; Li, H.; McLeod, Terry; Smith, Katherine L.; Zhang, Zhaoming; Weber, William J.; Thevuthasan, Suntharampillai

    2004-01-01

    In this paper, we discuss the effect of ion irradiation on pyrochlore-rich titanate and defect-fluorite zirconate ceramics designed for plutonium immobilization. Samples, with Ce as an analogue for Pu, were made via oxide routes and consolidated by cold-pressing and sintering. Ion irradiation damage was carried out with 2 MeV Au2+ ions to a fluence of 5 ions nm-2 in the accelerator facilities within the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory. Irradiated and non-irradiated samples were examined by x-ray diffraction, scanning and transmission electron microscopy, x-ray photoelectron and infrared spectroscopy, and spectroscopic ellipsometry. Samples underwent accelerated leach testing at pH 1.75 (nitric acid) at 90 C for 28 days. The zirconate samples were more ion-irradiation damage resistant than the titanate samples, showing little change after ion-irradiation whereas the titanate samples formed an amorphous surface layer ∼ 500 nm thick. While all samples had high aqueous durability, the titanate leach rate was ∼ 5 times that of the zirconate. The ion-irradiation increased the leach rate of the titanate without impurities by ∼ 5 times. The difference in the leach rates between irradiated and unirradiated zirconate samples is small. However, the zirconates were less able to incorporate impurities than the titanate ceramics and required higher sintering temperatures, ∼ 1500 C compared to 1350 C for the titanates.

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

    Science.gov (United States)

    Popov, Dmitri; Maliev, Slava; Jones, Jeffrey

    irradiation was generated in heavy ion (Fe56) accelerator - UTI. Heavy Ion linear transfer energy - 2000- 2600 KeV -mkm, 600 MeV -92U. Absorbed Dose - 3820 Rad. Experimental Design: Rabbits from all groups were irradiated by heavy ion accelerator. Group A: control-10 rabbits; Group B: placebo-5 rabbits; Group C: Radioprotectant Cystamine (50 mg-kg)-5 rabbits, 15 minutes before irradiation - 5 rabbits; Group D: Radioprotectant Gammafos (Amifostine 400mg -kg ) - 5 rabbits; Group E: Antiradiation Vaccine: subcutaneus administration or IM - 2 ml of active substance, 14 days before irradiation Results: Group A 100% mortality within two hours after heavy ion irradiation with clinical symptoms of Acute Cerebro- and Cardio-Vascular Radiation syndromes. Group B 100% mortality within 15 hours following irradiation. Group C 100% mortality within 14-15 hours after irradiation. Group D 100% mortality within 15-16 hours after irradiation. In groups A- D registered the development of acute radiation cerebrovascular and cardiovascular syndromes and also extensive burns. of skin produced rapid death. Group E -100% mortality in 280-290 hours (12 days) following heavy ion irradiation with animals exhibiting a combination or individual forms of Acute Cerebrovascular, Cardiovascular, and Gastrointestinal forms and focal skin burns. Discussion Antiradiation vaccine and immune-prophylaxis is an effective method of neutralization of Radiation Toxins. Vaccination before irradiation extended survival time after irradiation with heavy ions from two hours up to 300 hours. Clinical signs, clinical features, symptoms were somewhat attenuated. Degree of clinical forms of Acute Radiation Syndromes were diminished in their clinical manifestation and severity. Groups A-D demonstrated extremely severe level of Cerebrovascular and Cardiovascular forms of Acute Radiation Syndromes and lethality 100% was registered in short time after irradiation. Radiation induced burns in this groups (with Cutaneous sub

  1. Early Stage of Deformation under Nanoindenter Tip of Ion-irradiated Single Crystals

    International Nuclear Information System (INIS)

    Shin, Chan Sun; Jin, Hyung Ha; Kwon, Jun Hyun

    2010-01-01

    Ion irradiation has been used for almost 40 years to emulate the effect of neutrons. Ion irradiation has a number of advantages in terms of time and expenses compared to neutron irradiation. Ion irradiation is expected to greatly contribute to the development of Fusion and Gen IV materials. Ions have short penetration depth, and they induce continuously varying dose rate over the penetration depth. Although it depends on the energy and species of incident ions, the depth of ion-irradiated region is in general on the order of a few micron meters. Depth controlled probing technique is required to measure the mechanical properties of ion-irradiated layer, and nanoindentation is widely used. During nanoindentation, a hard tip with known properties is pressed into a material which has unknown properties. The depth of penetration and load on the indenter are recorded during loading and unloading. The initial Loading depth curve follows the Hertzian elastic solution, and at a certain load, a sudden displacement excursion occurs in indenter depth and then hardening follows. This is called 'Pop-in' event, and since residual impression can be found only after pop-ins, the pop-in is regarded as the onset of plasticity. The objectives of this research are to investigate the effects of ion irradiation on popins, and to examine dislocation nucleation and propagation at the onset of plasticity by using MD simulations

  2. Early Stage of Deformation under Nanoindenter Tip of Ion-irradiated Single Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chan Sun; Jin, Hyung Ha; Kwon, Jun Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    Ion irradiation has been used for almost 40 years to emulate the effect of neutrons. Ion irradiation has a number of advantages in terms of time and expenses compared to neutron irradiation. Ion irradiation is expected to greatly contribute to the development of Fusion and Gen IV materials. Ions have short penetration depth, and they induce continuously varying dose rate over the penetration depth. Although it depends on the energy and species of incident ions, the depth of ion-irradiated region is in general on the order of a few micron meters. Depth controlled probing technique is required to measure the mechanical properties of ion-irradiated layer, and nanoindentation is widely used. During nanoindentation, a hard tip with known properties is pressed into a material which has unknown properties. The depth of penetration and load on the indenter are recorded during loading and unloading. The initial Loading depth curve follows the Hertzian elastic solution, and at a certain load, a sudden displacement excursion occurs in indenter depth and then hardening follows. This is called 'Pop-in' event, and since residual impression can be found only after pop-ins, the pop-in is regarded as the onset of plasticity. The objectives of this research are to investigate the effects of ion irradiation on popins, and to examine dislocation nucleation and propagation at the onset of plasticity by using MD simulations

  3. Development of heavy-ion irradiation technique for single-event in semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Norio; Akutsu, Takao; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Naitoh, Ichiro; Itoh, Hisayoshi; Agematsu, Takashi; Kamiya, Tomihiro; Nashiyama, Isamu

    1997-03-01

    Heavy-ion irradiation technique has been developed for the evaluation of single-event effects on semiconductor devices. For the uniform irradiation of high energy heavy ions to device samples, we have designed and installed a magnetic beam-scanning system in a JAERI cyclotron beam course. It was found that scanned area was approximately 4 x 2 centimeters and that the deviation of ion fluence from the average value was less than 7%. (author)

  4. Low energy helium ion irradiation induced nanostructure formation on tungsten surface

    International Nuclear Information System (INIS)

    Al-Ajlony, A.; Tripathi, J.K.; Hassanein, A.

    2017-01-01

    We report on the low energy helium ion irradiation induced surface morphology changes on tungsten (W) surfaces under extreme conditions. Surface morphology changes on W surfaces were monitored as a function of helium ion energy (140–300 eV), fluence (2.3 × 10 24 –1.6 × 10 25 ions m −2 ), and flux (2.0 × 10 20 –5.5 × 10 20 ion m −2 s −1 ). All the experiments were performed at 900° C. Our study shows significant effect of all the three ion irradiation parameters (ion flux, fluence, and energy) on the surface morphology. However, the effect of ion flux is more pronounced. Variation of helium ion fluence allows to capture the very early stages of fuzz growth. The observed fuzz growth and morphology changes were understood in the realm of various possible phenomena. The study has relevance and important impact in the current and future nuclear fusion applications. - Highlights: •Reporting formation of W nanostructure (fuzz) due to low energy He ion beam irradiation. •Observing the very early stages for the W-Fuzz formation. •Tracking the surface morphological evolution during the He irradiation. •Discussing in depth our observation and drawing a possible scenario that explain this phenomenon. •Studying various ions irradiation parameters such as flux, fluence, and ions energy.

  5. Low energy helium ion irradiation induced nanostructure formation on tungsten surface

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ajlony, A., E-mail: montaserajlony@yahoo.com; Tripathi, J.K.; Hassanein, A.

    2017-05-15

    We report on the low energy helium ion irradiation induced surface morphology changes on tungsten (W) surfaces under extreme conditions. Surface morphology changes on W surfaces were monitored as a function of helium ion energy (140–300 eV), fluence (2.3 × 10{sup 24}–1.6 × 10{sup 25} ions m{sup −2}), and flux (2.0 × 10{sup 20}–5.5 × 10{sup 20} ion m{sup −2} s{sup −1}). All the experiments were performed at 900° C. Our study shows significant effect of all the three ion irradiation parameters (ion flux, fluence, and energy) on the surface morphology. However, the effect of ion flux is more pronounced. Variation of helium ion fluence allows to capture the very early stages of fuzz growth. The observed fuzz growth and morphology changes were understood in the realm of various possible phenomena. The study has relevance and important impact in the current and future nuclear fusion applications. - Highlights: •Reporting formation of W nanostructure (fuzz) due to low energy He ion beam irradiation. •Observing the very early stages for the W-Fuzz formation. •Tracking the surface morphological evolution during the He irradiation. •Discussing in depth our observation and drawing a possible scenario that explain this phenomenon. •Studying various ions irradiation parameters such as flux, fluence, and ions energy.

  6. Quantitative analysis of genes regulating sensitivity to heavy ion irradiation in cultured cell lines of malignant choroid melanoma

    International Nuclear Information System (INIS)

    Kumagai, Ken; Adachi, Nanao; Nimura, Yoshinori

    2004-01-01

    As a treatment strategy for malignant melanoma, heavy ion irradiation has been planned in National Institute of Radiological Sciences (NIRS). However, the molecular biology of the malignant melanoma cell after irradiation of heavy ion is still unknown. In this study, we used resistant and sensitive cell lines of malignant melanoma to study the effects of heavy ion irradiation. Furthermore, gene expression profiling of early response genes for heavy ion irradiation was carried out on these cell lines using microarray technology. (author)

  7. Quantitative analysis of genes regulating sensitivity to heavy ion irradiation in cultured cell lines of malignant choroid melanoma

    International Nuclear Information System (INIS)

    Kumagai, Ken; Nimura, Yoshinori; Kato, Masaki; Seki, Naohiko; Miyahara, Nobuyuki; Aoki, Mizuho; Shino, Yayoi; Furusawa, Yoshiya; Mizota, Atsushi

    2005-01-01

    As a treatment strategy for malignant melanoma, heavy ion irradiation has been planned in National Institute of Radiological Sciences (NIRS). However, the molecular biology of the malignant melanoma cell after irradiation of heavy ion is still unknown. In this study, we used resistant and sensitive cell lines of malignant melanoma to study the effects of heavy ion irradiation. Furthermore, gene expression profiling of early response genes for heavy ion irradiation was carried out on these cell lines using microarray technology. (author)

  8. The effects of xenon ion irradiation on the photoluminesce behavior of poly(p-cresolformaldeyde)/diazonaphtoquinone thin films

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Irene T.S. [Depto. de Quimica Analitica e Inorganica, Instituto de Quimica e Geociencias, UFPel, Capao do Leao s/n, 96010-900, Pelotas, RS (Brazil)], E-mail: irene@ufpel.edu.br; Zawislak, F.C.; Balzaretti, Naira [Instituto de Fisica, UFRGS, Caixa Postal 15051, 91501-970 Porto Alegre (Brazil); Samios, D. [Instituto de Quimica, UFRGS, 91501-970 Porto Alegre (Brazil); Sias, U. [Centro Federal de Educacao Tecnologica de Pelotas, 96015-360 Pelotas (Brazil)

    2007-10-15

    In the present paper, we investigate the origin of photoluminescence (PL) and the changes in the optical properties: refractive index and absorption coefficient, in poly(p-cresolformaldeyde) and diazonaphtoquinone thin films irradiated with Xe ions. Films 400 nm thick have been irradiated with 800 keV Xe{sup 2+} ions in a fluence range from 10{sup 13} to 6 x 10{sup 15} Xe cm{sup -2}. The structural modifications were followed by the techniques of nuclear reaction analysis, elastic recoil detection analysis, Rutherford backscattering, Fourier transform infrared and Raman spectroscopies. The PL behavior was characterised with 488 nm excitation wavelength. The pristine films show emission with maxima of the main bands located at 635, 720 and 830 nm. For fluences up to 10{sup 14} Xe cm{sup -2}, the photoluminescence intensity increases with the irradiation fluence. The chain mobility lowering, characterized by the crosslinked structure, explains this behavior in organic systems. Other possible contribution for increasing of PL intensity, at these fluences, is the presence of oxygen trapped in the polymer chains by the dangling bonds. At intermediate and higher fluences, the photoluminescence starts to decrease. At fluences higher than 10{sup 14} Xe cm{sup -2}, irreversible changes of the organic structure occur and they are characterized by large losses of oxygen and hydrogen, transforming the material into amorphous carbon films. The loss of photoluminescent behavior is associated with the light absorption characteristics of the amorphous carbon structure. This conclusion is supported by the observed increase of the refractive indexes and absorption coefficients, obtained in the infrared region, as well as by the Raman results. Also, the effect of irradiation modifying the refractive index in the infrared region suggests the application of these films as waveguide in this region of wavelength.

  9. Ion irradiation-induced precipitation of Cr23C6 at dislocation loops in austenitic steel

    International Nuclear Information System (INIS)

    Jin, Shuoxue; Guo, Liping; Luo, Fengfeng; Yao, Zhongwen; Ma, Shuli; Tang, Rui

    2013-01-01

    The irradiation-induced precipitates in argon ion-irradiated austenitic stainless steel at 550 °C were examined via transmission electron microscopy. The selected-area electron diffraction patterns of precipitates indicated unambiguously that the precipitates were Cr 23 C 6 carbides. It was observed directly for the first time that irradiation-induced Cr 23 C 6 precipitates formed at dislocation loops in austenitic stainless steel, and coarsened with increasing irradiation dose.

  10. 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

  11. 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.

  12. Basic Design Study on 1-MV Electrostatic Accelerator for ion irradiation

    International Nuclear Information System (INIS)

    Cho, Yongsub; Kim, Kyeryung; Lee, Chanyoung

    2014-01-01

    The KOMAC (KOrea Multi-purpose Accelerator Complex) has electrostatic ion accelerators whose terminal voltages are less than 100kV. To extend ion beam irradiations with higher energy ions for industrial purposes, an electrostatic accelerator of 1-MV terminal voltage should have been studied. For industrial applications, the most important features of the accelerator are high current and high reliability for high irradiation dose and high through-put with high current and long irradiation time. The basic study on 1-MV electrostatic ion accelerator for industrial applications has been done. The key components are a high voltage power supply, an ion source, and an accelerating column. The feasibility study for fabrication is being performed. Especially the R and D for ion source is required. The 1-MV ion accelerator will be constructed with domestic companies and installed in the beam application research building, which is under construction in the site of KOMAC at Gyeongju

  13. Microanalysis on the Hydrogen Ion Irradiated 50 wt pct TiC-C Films

    Institute of Scientific and Technical Information of China (English)

    Hui JIANG; Yaoguang LIU; Ningkang HUANG

    2007-01-01

    The 50 wt pct TiC-C films were prepared on stainless steel substrates by using a technique of ion beam mixing.These films were irradiated by hydrogen ion beam with a dose of 1×1018 ions/cm2 and an energy of 5 keV.Microanalysis of X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) were used to analyze the films before and after hydrogen ion irradiation and to study the mechanism of hydrogen resistance.

  14. Compton polarimetry of 6-35 keV X-rays. Influence of Breit interaction on the linear polarisation of KLL dielectronic recombination transitions in highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Joerg, Holger Eric

    2016-12-21

    The polarisation of X-rays emitted during K shell dielectronic recombination (DR) into highly charged ions was studied using electron beam ion traps. In the first experiment, the degree of linear polarisation of X-rays due to K shell DR transitions of highly charged krypton ions was measured with a newly developed Compton polarimeter based on SiPIN diodes. Such polarisation measurements allow a study of the population mechanism of magnetic sublevels in collisions between electrons and ions. In a second experiment, the influence of Breit interaction between electrons on the polarisation of X-rays emitted during K shell DR into highly charged xenon ions was studied. Here, polarisation measurements provide an access to the finer details of the electron-electron interaction in electron-ion collisions. Furthermore, a second Compton polarimeter based on silicon drift detectors has been developed for polarisation measurements at synchrotrons. It has been developed for X-ray polarimetry with a high energy resolution for energies between 6 keV and 35 keV. It was tested in the course of polarisation measurements at an electron beam ion trap and at a synchrotron radiation source.

  15. MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Jeynes, J.C.G.; Merchant, M.J.; Kirkby, K.; Kirkby, N. [Surrey Ion Beam Center, Faculty of Engineering and Physical Science, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

  16. Density changes in amorphous Pd80Si20 during low temperature ion irradiation

    International Nuclear Information System (INIS)

    Schumacher, G.; Birtcher, R.C.; Rehn, L.E.

    1994-11-01

    Density changes in amorphous Pd 80 Si 20 during ion irradiation below 100K were detected by in situ HVEM measurements of the changes in specimen length as a function of ion fluence. A decrease in mass density as a function of the ion fluence was observed. The saturation value of the change in mass density was determined to be approximately -1.2%

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  18. Microstructural evolution of nanochannel CrN films under ion irradiation at elevated temperature and post-irradiation annealing

    Science.gov (United States)

    Tang, Jun; Hong, Mengqing; Wang, Yongqiang; Qin, Wenjing; Ren, Feng; Dong, Lan; Wang, Hui; Hu, Lulu; Cai, Guangxu; Jiang, Changzhong

    2018-03-01

    High-performance radiation tolerance materials are crucial for the success of future advanced nuclear reactors. In this paper, we present a further investigation that the "vein-like" nanochannel films can enhance radiation tolerance under ion irradiation at high temperature and post-irradiation annealing. The chromium nitride (CrN) nanochannel films with different nanochannel densities and the compact CrN film are chosen as a model system for these studies. Microstructural evolution of these films were investigated using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Elastic Recoil Detection (ERD) and Grazing Incidence X-ray Diffraction (GIXRD). Under the high fluence He+ ion irradiation at 500 °C, small He bubbles with low bubble densities are observed in the irradiated nanochannel CrN films, while the aligned large He bubbles, blistering and texture reconstruction are found in the irradiated compact CrN film. For the heavy Ar2+ ion irradiation at 500 °C, the microstructure of the nanochannel CrN RT film is more stable than that of the compact CrN film due to the effective releasing of defects via the nanochannel structure. Under the He+ ion irradiation and subsequent annealing, compared with the compact film, the nanochannel films have excellent performance for the suppression of He bubble growth and possess the strong microstructural stability. Basing on the analysis on the sizes and number densities of bubbles as well as the concentrations of He retained in the nanochannel CrN films and the compact CrN film under different experimental conditions, potential mechanism for the enhanced radiation tolerance are discussed. Nanochannels play a crucial role on the release of He/defects under ion irradiation. We conclude that the tailored "vein-like" nanochannel structure may be used as advanced radiation tolerance materials for future nuclear reactors.

  19. 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