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Sample records for carbon ion induced

  1. Damage to plasmid DNA induced by low energy carbon ions

    International Nuclear Information System (INIS)

    The damage induced in supercoiled plasmid DNA molecules by 1-6 keV carbon ions has been investigated as a function of ion exposure, energy and charge state. The production of short linear fragments through multiple double strand breaks has been demonstrated and exponential exposure responses for each of the topoisomers have been found. The cross section for the loss of supercoiling was calculated to be (2.2 ± 0.5) x 10-14 cm2 for 2 keV C+ ions. For singly charged carbon ions, increased damage was observed with increasing ion energy. In the case of 2 keV doubly charged ions, the damage was greater than for singly charged ions of the same energy. These observations demonstrate that ion induced damage is a function of both the kinetic and potential energies of the ion

  2. Erythrocyte stiffness during morphological remodeling induced by carbon ion radiation.

    Directory of Open Access Journals (Sweden)

    Baoping Zhang

    Full Text Available The adverse effect induced by carbon ion radiation (CIR is still an unavoidable hazard to the treatment object. Thus, evaluation of its adverse effects on the body is a critical problem with respect to radiation therapy. We aimed to investigate the change between the configuration and mechanical properties of erythrocytes induced by radiation and found differences in both the configuration and the mechanical properties with involving in morphological remodeling process. Syrian hamsters were subjected to whole-body irradiation with carbon ion beams (1, 2, 4, and 6 Gy or X-rays (2, 4, 6, and 12 Gy for 3, 14 and 28 days. Erythrocytes in peripheral blood and bone marrow were collected for cytomorphological analysis. The mechanical properties of the erythrocytes were determined using atomic force microscopy, and the expression of the cytoskeletal protein spectrin-α1 was analyzed via western blotting. The results showed that dynamic changes were evident in erythrocytes exposed to different doses of carbon ion beams compared with X-rays and the control (0 Gy. The magnitude of impairment of the cell number and cellular morphology manifested the subtle variation according to the irradiation dose. In particular, the differences in the size, shape and mechanical properties of the erythrocytes were well exhibited. Furthermore, immunoblot data showed that the expression of the cytoskeletal protein spectrin-α1 was changed after irradiation, and there was a common pattern among its substantive characteristics in the irradiated group. Based on these findings, the present study concluded that CIR could induce a change in mechanical properties during morphological remodeling of erythrocytes. According to the unique characteristics of the biomechanical categories, we deduce that changes in cytomorphology and mechanical properties can be measured to evaluate the adverse effects generated by tumor radiotherapy. Additionally, for the first time, the current study

  3. Ion-irradiation-induced defects in bundles of carbon nanotubes

    CERN Document Server

    Salonen, E; 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.

  4. Characterization of carbon ion implantation induced graded microstructure and phase transformation in stainless steel

    International Nuclear Information System (INIS)

    Austenitic stainless steel 316L is ion implanted by carbon with implantation fluences of 1.2 × 1017 ions-cm− 2, 2.4 × 1017 ions-cm− 2, and 4.8 × 1017 ions-cm− 2. The ion implantation induced graded microstructure and phase transformation in stainless steel is investigated by X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. The corrosion resistance is evaluated by potentiodynamic test. It is found that the initial phase is austenite with a small amount of ferrite. After low fluence carbon ion implantation, an amorphous layer and ferrite phase enriched region underneath are formed. Nanophase particles precipitate from the amorphous layer due to energy minimization and irradiation at larger ion implantation fluence. The morphology of the precipitated nanophase particles changes from circular to dumbbell-like with increasing implantation fluence. The corrosion resistance of stainless steel is enhanced by the formation of amorphous layer and graphitic solid state carbon after carbon ion implantation. - Highlights: • Carbon implantation leads to phase transformation from austenite to ferrite. • The passive film on SS316L becomes thinner after carbon ion implantation. • An amorphous layer is formed by carbon ion implantation. • Nanophase precipitate from amorphous layer at higher ion implantation fluence. • Corrosion resistance of SS316L is improved by carbon implantation

  5. Raman Spectroscopy of Irradiation Effect in Three Carbon Allotropes Induced by Low Energy B Ions

    Institute of Scientific and Technical Information of China (English)

    FU Yun-Chong; JIN Yun-Fan; YAO Cun-Feng; ZHANG Chong-Hong

    2009-01-01

    Irradiation effect in three carbon allotropes C6o, diamond and highly oriented pyrolytic graphite (HOPG) induced by 170 keV B ions, mainly including the process of the damage creation, is investigated by means of Rarnan spectroscopy technique. The differences on irradiation sensitivity and structural stability for C6o, HOPG and diamond are compared. The analysis results indicate that C6o is the most sensitive for B ions irradiation, diamond is the second one and the structure of HOPG is the most stable under B ion irradiation. The damage cross sections σ of C6o, diamond and HOPG deduced from the Raman spectra are 7.78 × 10-15, 6.38 × 10-15 and 1.31 × 10-15 cm-2, respectively.

  6. Characterization of ion-irradiation-induced defects in multi-walled carbon nanotubes

    Science.gov (United States)

    Lehtinen, Ossi; Nikitin, Timur; Krasheninnikov, Arkady V.; Sun, Litao; Banhart, Florian; Khriachtchev, Leonid; Keinonen, Juhani

    2011-07-01

    We study the effects of Ar+, He+ and C+ ion irradiation on multi-walled carbon nanotubes at room and elevated temperatures with transmission electron microscopy (TEM) and Raman spectroscopy. Based on the TEM data, we introduce a universal damage scale for the visual analysis and characterization of irradiated nanotubes. We show for the first time that the amount of irradiation-induced damage in nanotubes is larger than the value predicted for bulk materials using the simple binary collision approximation, which may be associated with higher defect production due to electronic stopping in these nanoscale systems. The Raman spectra of the irradiated samples are in qualitative agreement with the TEM data and indicate the presence of irradiation-induced defects. However, it is difficult to obtain quantitative information on defect concentration due to non-uniform distribution of defects in the nanotube films and in part due to the presence of other carbon nanosystems in the samples, such as graphitic crystallites and carbon onions.

  7. Study on the adaptive response of mammalian cells induced by low dose radiation of carbon ions

    International Nuclear Information System (INIS)

    The effect of high LET carbon ions irradiation with low dose on V79 Chinese hamster cells and B16 melanoma cells were investigated. The cells were treated with inducing doses of 0.02 Gy and 0.05 Gy first, and then with challenge dose of 1 Gy after-additional culture of 4h. The adaptive responses including survival fraction and micronucleus frequency were studied. Authors' results showed that when the inducing dose was chosen as 0.02 Gy, there were marked increase of surviving fraction and decrease of micronucleus frequency in both cell lines. On the contrary, when the inducing dose was chosen as 0.05 Gy, there was no statistical change of surviving fraction, furthermore, the micronucleus frequency increased a little. This meant that high LET radiation of 0.02 Gy could induce the adaptive response of cultured cells while 0.05 Gy can not. Meanwhile, there was a good linear relationship between micronucleus frequency and surviving fraction, cells pre-exposed to low dose such as 0.02 Gy had low micronucleus frequency and high surviving fraction

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

    Science.gov (United States)

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

    2016-07-01

    Large number of researches on rice after spaceflights indicated that rice was a favorable model organism to study biological effects induced by space radiation. The stimulative effect could often be found on rice seedlings after irradiation by low-dose energetic heavy-ion radiation. Spaceflight also could induce stimulative effect on kinds of seeds. To further understand the mechanism of low-dose radiation biological effects and the dose range, the germinated rice seeds which were irradiated by different doses of carbon heavy-ion (0, 0.02, 0.1, 0.2, 1, 2, 5, 10, 15 and 20Gy, LET=27.3keV/µm) were used as materials to study. By investigating the variation of rice phenotype under different doses, we found that 2Gy radiation dose was a dividing point of the phenotypic variation. Transmission electron microscopy was used to observe the variation of mitochondria, chloroplast, endoplasmic reticulum, ribosome and nucleus in mesophyll cell of rice apical meristem at 24 hours after radiation with different doses. The cells were not apparently physiologically damaged when the dose of radiation was less than 2Gy. The number of chloroplast did not change significantly, but the number of mitochondria was significantly increased, and gathered around in the chloroplast and endoplasmic reticulum; the obvious lesion of chloroplast and mitochondria were found at the mesophyll cells when radiation dose was higher than 2Gy. The mitochondria were swelling and appearing blurred crest. The chloroplast and mitochondrial mutation rate increased significantly (pplant. Keywords: Heavy-ion radiation; Low dose; Stimulation effect; Inhibition effect; Rice.

  9. Effects of beer administration in mice on acute toxicities induced by X rays and carbon ions

    International Nuclear Information System (INIS)

    We have investigated the tissue specificity of radioprotection by beer, which was previously found for human lymphocytes. C3H/He female mice, aged 14 weeks, received an oral administration of beer, ethanol or saline at a dose of 1 ml/mouse 30 min before whole-body irradiation with 137Cs γ rays or 50 keV/μm carbon ions. The dicentrics of chromosome aberrations in spleen cells were significantly (p0 (slope of a dose-survival curve) for γ rays and carbon ions as well. Beer administration significantly (p50/30 (radiation dose required to kill 50% of mice within 30 days) for γ rays and carbon ions. Ethanol-administration also significantly (p50/30 value for γ rays, but not for carbon ions. It is concluded that beer administration reduces the radiation injury caused by photons and carbon ions, depending on the tissue type. Radioprotection by beer administration is not solely due to OH radical-scavenging action by the ethanol contained in beer. (author)

  10. Carbon-ion beam irradiation kills X-ray-resistant p53-null cancer cells by inducing mitotic catastrophe.

    Directory of Open Access Journals (Sweden)

    Napapat Amornwichet

    Full Text Available BACKGROUND AND PURPOSE: To understand the mechanisms involved in the strong killing effect of carbon-ion beam irradiation on cancer cells with TP53 tumor suppressor gene deficiencies. MATERIALS AND METHODS: DNA damage responses after carbon-ion beam or X-ray irradiation in isogenic HCT116 colorectal cancer cell lines with and without TP53 (p53+/+ and p53-/-, respectively were analyzed as follows: cell survival by clonogenic assay, cell death modes by morphologic observation of DAPI-stained nuclei, DNA double-strand breaks (DSBs by immunostaining of phosphorylated H2AX (γH2AX, and cell cycle by flow cytometry and immunostaining of Ser10-phosphorylated histone H3. RESULTS: The p53-/- cells were more resistant than the p53+/+ cells to X-ray irradiation, while the sensitivities of the p53+/+ and p53-/- cells to carbon-ion beam irradiation were comparable. X-ray and carbon-ion beam irradiations predominantly induced apoptosis of the p53+/+ cells but not the p53-/- cells. In the p53-/- cells, carbon-ion beam irradiation, but not X-ray irradiation, markedly induced mitotic catastrophe that was associated with premature mitotic entry with harboring long-retained DSBs at 24 h post-irradiation. CONCLUSIONS: Efficient induction of mitotic catastrophe in apoptosis-resistant p53-deficient cells implies a strong cancer cell-killing effect of carbon-ion beam irradiation that is independent of the p53 status, suggesting its biological advantage over X-ray treatment.

  11. Effect of ion irradiation induced structure changes in glass-carbon materials on the temperature dependence of ion-electron emission

    International Nuclear Information System (INIS)

    An experimental study is made into the effect of high-dose irradiation with normal incident with 30 keV molecular nitrogen ions on temperature dependences of an ion-electron emission yield γ(T) and the structure of a modified surface layer in glassy carbons. It is revealed that for glassy carbon specimens prepared within a temperature range of 1300-2500 Deg C the temperature curves γ(T) demonstrate step-by-step changes of γ at temperatures ranging from 20 to 300 Deg C that permits monitoring ion-induced structural transformations in a surface layer of the material. For the glassy carbon material with a lower temperature of preparation analogous step-by-step changes are not observed

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

    CERN Document Server

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

    2011-01-01

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

  13. A comparative study on micronuclei production induced by carbon ion versus 60Co γ-rays in human peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Objective: To compare the effectiveness of carbon ion versus 60Co γ-rays in producing micronuclei in human peripheral blood lymphocytes. Method: Heparinized whole blood samples were exposed to carbon ion and 60Co γ-rays, respectively. Micronuclei in binuclear lymphocytes (CB method) were scored. Relative biological effectiveness (RBE) values were calculated. Results: RBE values of carbon ion decreased with increasing dose (ranged from 1.78 to 4.19 ). The average RBE value is 2.56. Conclusion: Carbon ion has higher biological effectiveness in inducing micronuclei than 60Co γ-rays do

  14. Bystander effects induced by the low-fluence irradiation of carbon and iron ions (6 MeV/n)

    International Nuclear Information System (INIS)

    Many reports are available regarding bystander effects after exposure to low fluences of alpha particles and helium ions. However, few studies have examined bystander cellular effects after exposure to low fluences of ion species heavier than helium. We has been investigating bystander effects using both human normal fibroblasts and tumor cell lines irradiated with low energy (6 MeV/n) carbon or iron ions generated with the Medium Energy Beam Course. This year we focused on the bystander cellular effects as follows; Bystander cell-killing effect in human tumor cell lines irradiated with carbon ions. Relationship of bystander lethal effect between p53-wild and p53-mutated cells. Bystander cell-killing effect was observed in human normal and tumor cells harboring wild-type p53, but not in p53-mutated tumor cells. Moreover, observed bystander effect was suppressed by treating with a specific inhibitor of gap-junction mediated cell-cell communication. There is evidence that p53- and gap-junction-related bystander effect is an important role of carbon-ion induced lethal effect. (author)

  15. Formation and growth mechanisms of ion-induced iron-carbon nanocomposites at room temperature

    International Nuclear Information System (INIS)

    The irradiation of graphite surfaces with a simultaneous Fe supply have resulted into the development of various types of carbon nanocomposites. Their morphologies - diameter, density, length and apex angle strongly depend on the ratios of Fe deposition rate (DFe) to ion sputtering rate (Sion). By optimizing the ratio of DFe/Sion (2.40%), the denser and well-aligned Fe-carbon nanocomposite fibers (Fe-CNFs) could be obtained, whose average length and diameter were 0.95 μm and 17 nm, respectively. As confirmed by energy-dispersive X-ray analysis, the Fe-CNFs with amorphous-like or fine-polycrystalline phase were surely composed of carbon and Fe. Two types of growth models have been employed to explain the formation of metal-carbon nanocomposites.

  16. Swift heavy ion induced modifications of single walled carbon nanotube thin films

    Science.gov (United States)

    Vishalli; Raina, K. K.; Avasthi, D. K.; Srivastava, Alok; Dharamvir, Keya

    2016-04-01

    Thin films of single walled carbon nanotubes (SWCNTs) were prepared by Langmuir-Blodgett method and irradiated with swift heavy ions, carbon and nickel each of energy 60 MeV. The ion beams have different electronic energy loss (Se) values and the samples were exposed to various irradiation doses. The irradiated films were characterized using Raman and optical absorption spectroscopy. Raman spectroscopy results indicate the competing processes of defect creation and healing (annealing) of SWCNTs at lower fluences, while at higher fluences defect creation or damage dominates. In UV-Vis-NIR spectroscopy we find that there is decrease in the intensity of characteristic peaks with every increasing fluence, indicating decrease in the optically active states with irradiation.

  17. Carbon ion induced DNA double-strand breaks in melanophore B16

    International Nuclear Information System (INIS)

    DNA double-strand breaks (DSBs) in melanophore B16 induced by plateau and extended Bragg peak of 75 MeV/u 12C6+ ions were studied by using a technique of inverse pulsed-field gel electrophoresis (PIGE). DNA fragment lengths were distributed in two ranges: the larger in 1.4 Mbp-3.2 Mbp and the smaller in less than 1.2 Mbp. It indicates that distribution of DNA fragments induced by heavy ion irradiation is not stochastic and there probably are sensitive sites to heavy ions in DNA molecules of B16. Percentage of DNA released from plug (PR) increased and trended towards a quasi-plateau ∝85% as dose increased. Content of the larger fragments decreased and flattened with increasing dose while content of the smaller ones increased and trended towards saturation. (orig.)

  18. Carbon ion induced DNA double-strand breaks in melanophore B{sub 16}

    Energy Technology Data Exchange (ETDEWEB)

    Wei Zengquan; Zhou Guangming; Wang Jufang; He Jing; Li Qiang; Li Wenjian; Xie Hongmei; Cai Xichen; Tao Huang; Dang Bingrong; Han Guangwu [Chinese Academy of Sciences, Lanzhou (China). Inst. of Modern Physics; Gao Qingxiang [Lanzhou Univ. (China)

    1997-09-01

    DNA double-strand breaks (DSBs) in melanophore B{sub 16} induced by plateau and extended Bragg peak of 75 MeV/u {sup 12}C{sup 6+} ions were studied by using a technique of inverse pulsed-field gel electrophoresis (PIGE). DNA fragment lengths were distributed in two ranges: the larger in 1.4 Mbp-3.2 Mbp and the smaller in less than 1.2 Mbp. It indicates that distribution of DNA fragments induced by heavy ion irradiation is not stochastic and there probably are sensitive sites to heavy ions in DNA molecules of B{sub 16}. Percentage of DNA released from plug (PR) increased and trended towards a quasi-plateau {proportional_to}85% as dose increased. Content of the larger fragments decreased and flattened with increasing dose while content of the smaller ones increased and trended towards saturation. (orig.)

  19. Controlling the apex angle of carbon cone induced by 1.2 keV argon ions at room temperature

    International Nuclear Information System (INIS)

    Carbon nanofiber-tipped-cones with controllable apex angle were fabricated by sputtering graphite with 1.2keV Ar+ ions in different incident angles at room temperature. The density of carbon cones was estimated at 1 x 109- 1 x 1010/cm2. The cones with carbon nanofiber were oriented to the ion-beam direction. By increasing the incidence from 30 degree to 60 degree, the apex angle of cones decreased from 33 degree to 20 degree, and the aspect ratio increased from 250nm/150nm to 1200nm/400nm. The decreased apex angle, and the increased aspect ratio and density of the cones, were attributed to decreasing effective diffuse coefficient induced by the ion beam and increasing sputtering yield. By increasing the current density from 200 μA/cm2 to 800 μA/cm2, the apex angle of cones decreased from 90 degree to 20 degree and the height of cones increased from 100nm to 1200nm. The increased dose rate caused by larger current densities of the ion beam should result in the different number of the sputtered atom or cluster, which was considered as reason of the decrement of the apex angle and the increment of the height of cones. (authors)

  20. Risk of simulated microgravity on testicular injury induced by high-LET carbon-ion beams in mice

    International Nuclear Information System (INIS)

    This study investigated the impact of simulated microgravity on acute injury induced by low doses of carbon ions in male reproductive organs of mice, and determined alterations in spermatogenic function and expression levels of apoptotic factors in mice following exposure to acute irradiation after 7 days of simulated microgravity. The results demonstrated that significant reductions in spermatozoa, primary spermatocytes and spermatogonia, and increased globular cells in seminiferous tubule and pro-apoptotic proteins were observed in the group exposed to over 0.4 Gy irradiation. Collectively, the data suggest that lesions inflicted by simulated microgravity are not markedly modified by lower doses of irradiation (0.2 Gy) in mouse testis compared to the control group. However, testicular impairments were markedly evident in the group exposed to higher doses of carbon ions plus simulated microgravity, which may be due at least in part to elevated apoptosis initiated by the mitochondrial apoptosis pathway in germ cells. (authors)

  1. Bystander effects induced by the low-fluence irradiation of carbon and iron ions (6 MeV/n)

    International Nuclear Information System (INIS)

    We reported here until now that bystander cellular effects, such as cell death and gene mutation induction, were strictly dependent on radiation quality. Bystander cellular effects were observed in carbon-ion irradiations, not iron-ion irradiations using low energy (6 MeV/n) carbon or iron ions generated with the Medium Energy Beam Course. Also, we reported in the last year that the bystander cell-killing effect was observed in human normal and tumor cells harboring wild-type p53-, but not in p53-mutated tumor cells. This year, we examine the bystander cell-killing effect using a human lung cancer cell line with same origin but different p53 status irradiated with carbon ions. The human lung cancer cell line (H1299) harboring either wild-type (H1299/wtp53) or mutated-type p53 (H1299/mp53), which cells were distributed by Dr. Takeo Ohnishi and Dr. Hediki Matsumoto, were used. The cell survivals between ''all cell irradiation group'' and ''half-cell irradiation group'' were almost the same level (55-60%) for H1299/wtp53 cells, but the cell survival of ''half cell irradiation group'' (around 55%) was higher than ''all cell irradiation group'' (around 80%) for H1299/mp53 cells. The results clearly showed that the bystander cell-killing effect occurred in H1299/wtp53 cells, not in H1299/mp53 cells. Together with the last year's report, there is evidence that p53 gene is an important role of carbon-ion induced bystander cell-killing effect. (author)

  2. Carbon Ion Therapy

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, David Christoffer; Herrmann, Rochus;

    On the importance of choice of target size for selective boosting of hypoxic tumor subvolumina in carbon ion therapy Purpose: Functional imaging methods in radiotherapy are maturing and can to some extent uncover radio resistant structures found within a tumour entity. Selective boost of identified...... to the surface where the beam enters) are examined. For each plan the minimum,  maximum and the dose averaged LET of the PTV is calculated. The numbers are translated to OER using several sets of data found in literature for various cell lines. Results: We find a strong dependence of the dose average LET and OER...... effect. All cell lines investigated here did not reach an OER of 1, even for the smaller structures, which may indicate that the achievable dose average LET of carbon ions is too low, and heavier ions than carbon may be considered for functional LET-painting....

  3. Targeting of Carbon Ion-Induced G2 Checkpoint Activation in Lung Cancer Cells Using Wee-1 Inhibitor MK-1775.

    Science.gov (United States)

    Ma, Hongyu; Takahashi, Akihisa; Sejimo, Yukihiko; Adachi, Akiko; Kubo, Nobuteru; Isono, Mayu; Yoshida, Yukari; Kanai, Tatsuaki; Ohno, Tatsuya; Nakano, Takashi

    2015-12-01

    The potent inhibitor of the cell cycle checkpoint regulatory factor Wee-1, MK-1775, has been reported to enhance non-small cell lung cancer (NSCLC) cell sensitivity to photon radiation by abrogating radiation-induced G2 arrest. However, little is known about the effects of this sensitizer after exposure to carbon (C)-ion radiation. The purpose of this study was therefore to investigate the effects of C ions in combination with MK-1775 on the killing of NSCLC cells. Human NSCLC H1299 cells were exposed to X rays or C ions (290 MeV/n, 50 keV/μm at the center of a 6 cm spread-out Bragg peak) in the presence of MK-1775. The cell cycle was analyzed using flow cytometry and Western blotting. Radiosensitivity was determined using clonogenic survival assays. The mechanisms underlying MK-1775 radiosensitization were studied by observing H2AX phosphorylation and mitotic catastrophe. G2 checkpoint arrest was enhanced 2.3-fold by C-ion exposure compared with X-ray exposure. Radiation-induced G2 checkpoint arrest was abrogated by MK-1775. Exposure to radiation resulted in a significant reduction in the mitotic ratio and increased phosphorylation of cyclin-dependent kinase 1 (Cdk1), the primary downstream mediator of Wee-1-induced G2 arrest. The Wee-1 inhibitor, MK-1775 restored the mitotic ratio and suppressed Cdk1 phosphorylation. In addition, MK-1775 increased H1299 cell sensitivity to C ions and X rays independent of TP53 status. MK-1775 also significantly increased H2AX phosphorylation and mitotic catastrophe in irradiated cells. These results suggest that the G2 checkpoint inhibitor MK-1775 can enhance the sensitivity of human NSCLC cells to C ions as well as X rays. PMID:26645158

  4. Ion induced transformation of polymer films into diamond-like carbon incorporating silver nano particles

    International Nuclear Information System (INIS)

    Silver containing diamond-like carbon (DLC) is an interesting material for medical engineering from several points of view. On the one hand DLC provides high mechanical robustness. It can be used as biocompatible and wear resistant coating for joint replacing implants. On the other hand silver has antimicrobial properties, which could reduce post-operative inflammations. However conventional production of Ag-DLC by co-deposition of silver and carbon in a plasma process is problematic since it does not allow for a separate control of nano particle morphology and matrix properties. In this work an alternative production method has been developed to circumvent this problem. In metall-DLC-production by ion implantation into a nano composite, silver nano particles are initially formed in solution and then incorporated within a polymer matrix. Finally the polymer is transformed into DLC by ion implantation. The aspects and single steps of this method were investigated with regard to the resulting material's properties. The goal was to design an economically relevant deposition method. Based on experimental results a model of the transformation process has been established, which has also been implemented in a computer simulation. Finally the antibacterial properties of the material have been checked in a biomedical test. Here a bacterial killing rate of 90% could be achieved. (orig.)

  5. Application of ion diagnostics to control the laser-induced removal of a surface layer of the carbon substrate

    International Nuclear Information System (INIS)

    Among other methods of the e-tritiation of in-vessel tokamak components the application of lasers for removal of fuel trapped in co-deposited layers is under investigation. The factors influencing the nature of the pulsed laser-mater interaction are the laser parameters (wavelength, repetition rate, pulse energy and duration) as well as the properties of the irradiated target. Changing these factors one can change the effects of laser-target interaction according to requirements of particular technology. The effect of laser-induced surface interaction (ablation) can be characterized using different measuring methods. The paper presents preparation and tests of ion diagnostic methods for on-line measurement of the amount and characteristics of ablated carbon, hydrogen/deuterium and contaminant species from the graphite target (plate) of the main toroidal limiter of the TEXTOR tokamak. For removal of the surface layer from the graphite target (plate) we have used a new repetitive Nd:YAG laser of the following parameters: EL ≤ 0.8 J at λL = 1.06 μm, EL ≤ 0.4 J at 0.53 μm and a pulse repetition rate ≤ 10 Hz. Determination of the characteristics of ions emitted from the laser-illuminated targets has been performed with the use of ion collectors and an electrostatic ion-energy analyzer. The main ion stream parameters were measured in dependences on number of laser shots and the laser power density on the target surface. The properties of modified carbon sample surface were determined with the use of optical methods and compared with the results of the ion measurements. Support by the Association EURATOM/IPPLM within the project P2 for conducting the research is gratefully acknowledged. (author)

  6. Isolated and clustered DNA lesions induced by high-energy iron and carbon ions

    Science.gov (United States)

    Ide, H.; Tanaka, R.; Nakaarai, Y.; Terato, H.; Furusawa, Y.

    During space flight astronauts are exposed to various types of radiation from sun and galactic cosmic rays, the latter of which contain high-energy charged particles such as Fe and C ions. The radiation risk to astronauts toward such high-energy charged particles has been assessed by ground-based experiments. When irradiated by ionizing radiation, DNA molecules suffer from oxidation of bases and strand breaks. The distribution of these lesions along the DNA strand may differ significantly between densely ionizing high-energy Fe and C ions and sparsely ionizing radiation like 60Co gamma-rays. Among various types of DNA damage, bistranded clustered lesions comprised of multiple oxidized bases or strand breaks on opposite strands within a few helical turns are of particular interest since they are assumed to be resistant to repair or induce faulty repair, hence resulting in cell killing and mutations. In the present study, we have analyzed isolated and clustered DNA lesions generated by high-energy Fe and C ions to elucidate the nature of DNA lesions. Plasmid DNA (pDEL19) was irradiated in 10 mM Tris buffer (pH 7.5) by Fe (500 MeV/amu) and C (290 MeV/amu) ions and 60Co gamma-rays. Single-strand breaks (SSB) and double-strand breaks (DSB) were quantified by analysis of conformational changes using agarose gel electrophoresis. For quantification of isolated and bistranded clustered base lesions, irradiated plasmid was exhaustively digested prior to agarose gel analysis by Endo III and Fpg that preferentially incise DNA at oxidative pyrimidine and purine lesions, respectively. The yield (site/Gy/nucleotide) of isolated damages (SSB and bases lesions) tended to decrease with increasing LET [gamma (0.2 keV/μ m) 0.77 (C) > 0.69 (Fe)]. This result is in contrast to the higher biological effectiveness (e.g. cell killing) of high-energy Fe and C ions than gamma-rays, suggesting a role of more complex damage clusters that cannot be distinguished by simple analysis of direct

  7. D-methionine as a protector for heavy ion radiation-induced oral mucositis. Evaluation of RBE of carbon-ion beams for epithelial thickness on mouse tongues

    International Nuclear Information System (INIS)

    To evaluate if D-methionine, the dextro-isomer of the common amino acid L-methionine, can prevent oral mucositis resulting from heavy ion irradiation during treatment for head and neck cancers. For the first study, relative biological effectiveness (RBE) of carbon-ion beams for epithelial thickness on mouse tongues was evaluated. The head of female C3H mice, 8 weeks old, were irradiated by five fractionated doses of carbon ion beams (290 MeV/u) or 150 kV X-rays to induce oral mucositis (ulcers on tongue). Six days after the last irradiation, mice were sacrificed. Excised tongues were evaluated macroscopically and microscopically. The thickness of the lingual epithelium was measured. The RBE of 6-cm spread-out Bragg peak (SOBP) (290 MeV/u) for epithelium on mouse tongues after fractionated doses is 1.82. It was almost the equivalent value as that for gut crypt survivals reported by enormous studies. (author)

  8. Light-particle emission in reactions induced with carbon and oxygen ions

    International Nuclear Information System (INIS)

    Preliminary results are presented from three different experiments in which light particles emitted during the course of heavy-ion-induced reactions have been studied. The common primary motivation for undertaking these studies was to determine the nature and extent of nonequilibrium particle emission. The three experiments involved measurements of energies, angular correlations, and multiplicities of neutrons or alpha particles emitted in coincidence with deeply inelastic products or with evaporation residues produced as follows: neutrons from reactions of 16O with 93Nb at 12.9 MeV/u; alphas produced in the same system; and neutrons produced in 12C reactions with 158Gd and in 13C reactions with 157Gd at about 12.4 MeV/u. 3 figures

  9. Biological features of an early-maturity mutant of sweet sorghum induced by carbon ions irradiation and its genetic polymorphism

    Science.gov (United States)

    Dong, Xicun; Li, Wenjian

    2012-08-01

    It is well known that heavy ions irradiation is characterized by a high linear energy transfer (LET) and relative biological effectiveness (RBE). These characters are believed to increase mutation frequency and mutation spectrum of plants or mammalian cells irradiated by heavy ions. Here we describe an early-maturity mutant of sweet sorghum induced by carbon ion irradiation. The growth period of this mutant was shortened by about 20 days compared to the wild type. The proline content of the mutant was increased by 11.05% while the malondialdehyde content was significantly lower than that of wild type. In addition, the RAPD analysis indicated that the percentage of polymorphism between the mutant KFJT-1 and the control KFJT-CK reached 5.26%. The gain of early-maturity might solve the problem in the northwest region of China where seeds of sweet sorghum cannot be mature because of early frost. The early-maturity mutant may be important for future space cultivation.

  10. Mobile ions on carbonate surfaces

    Science.gov (United States)

    Kendall, Treavor A.; Martin, Scot T.

    2005-07-01

    Surface ions move during the dissolution and growth of minerals. The present study investigates the density and the mobility of surface ions and the structure of the adsorbed water layer with changes in relative humidity (RH). The time evolution of the polarization force, which is induced by an electrically biased tip of an atomic force microscope, shows that the density and the mobility of surface ions increase with rising humidity, a finding which is consistent with increasing surface hydration. A marked change in the observations above 55% RH indicates a transition from a water layer formed by heteroepitaxial two-dimensional growth at low RH to one formed by multilayer three-dimensional growth at high RH. A comparison of the results of several rhombohedral carbonates ( viz. CaCO 3, FeCO 3, ZnCO 3, MgCO 3, and MnCO 3) shows that a long relaxation time of the polarization force at high RH is predictive of a rapid dissolution rate. This finding is rationalized by long lifetimes in terrace positions and hence greater opportunities for detachment of the ion to aqueous solution (i.e., dissolution). Our findings on the density and the mobility of surface ions therefore help to better constrain mechanistic models of hydration, ion exchange, and dissolution/growth.

  11. Proton and carbon ion therapy

    CERN Document Server

    Lomax, Tony

    2013-01-01

    Proton and Carbon Ion Therapy is an up-to-date guide to using proton and carbon ion therapy in modern cancer treatment. The book covers the physics and radiobiology basics of proton and ion beams, dosimetry methods and radiation measurements, and treatment delivery systems. It gives practical guidance on patient setup, target localization, and treatment planning for clinical proton and carbon ion therapy. The text also offers detailed reports on the treatment of pediatric cancers, lymphomas, and various other cancers. After an overview, the book focuses on the fundamental aspects of proton and carbon ion therapy equipment, including accelerators, gantries, and delivery systems. It then discusses dosimetry, biology, imaging, and treatment planning basics and provides clinical guidelines on the use of proton and carbon ion therapy for the treatment of specific cancers. Suitable for anyone involved with medical physics and radiation therapy, this book offers a balanced and critical assessment of state-of-the-art...

  12. Low-energy (30 keV) carbon ion induced mutation spectrum in the LacZα gene of M13mp18 double-stranded DNA

    International Nuclear Information System (INIS)

    Double-stranded M13mp18 DNA was irradiated with 30 keV carbon ions in dry state under vacuum to investigate the low-energy heavy ion induced mutation spectra. When the irradiated DNA was used to transfect Escherichia coli JM105, 3.6-5.7-fold increases in mutation frequency were observed, in contrast to the spontaneous group. Sequences of the 92 induced mutants showed that the carbon ions in this study could induce an interesting mutation spectrum in the lacZα gene. One-base mutations (96.8%) and base pair substitutions (56.4%) were predominant, most of which involved G:C base pairs (90.6%), especially G:C → T:A transversions (49.6%) and G:C → A:T transitions (39.6%). This is similar to the spectra induced by γ-rays in the same ds M13, wild type E. coli system. We also found a considerable amount of carbon ion induced one-base deletion (38.5%) and the mutation sites distribution on the target lacZα gene was obviously non-random. We compared this study with previous data employing γ-rays to discuss the possible causes of the mutation spectrum

  13. Polarization-induced distortion of ions in the pores of carbon electrodes for electrochemical capacitors

    OpenAIRE

    Ovín Ania, María Concepción; Pernak, J.; Stefaniak, F.; Raymundo-Piñero, Encarnación; Béguin, F.

    2009-01-01

    This paper reports the effect of confining ionic species of the electrolyte inside the porosity of carbon electrodes during the performance of electrochemical capacitors. Solvent-free ionic liquids and a conventional organic medium were used as electrolytes, while two series of carbons with controlled pore sizes – one of them obtained from nanocasting procedure – were used as electrode materials. Our results demonstrate that under the effect of the electric field applied during the polarizati...

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

    International Nuclear Information System (INIS)

    At the future FAIR facility, reliably working solid carbon stripper foils are desired for providing intermediate charge states to SIS18. With the expected high beam intensities, the foils experience enhanced degradation and limited lifetime due to severe radiation damage, stress waves, and thermal effects. This work presents systematic measurements of the temperature of different carbon-based stripper foils (amorphous, diamond-like, and carbon-nanotube based) exposed to 4.8 MeV/u U, Bi, and Au beams of different pulse intensities. Thermal and spectroscopic analyses were performed by means of infrared thermography and Fourier transform infrared spectroscopy. The resulting temperature depends on the foil thickness and strongly increases with increasing pulse intensity and repetition rate. (author)

  15. Carbon-ion beams induce production of an immune mediator protein, high mobility group box 1, at levels comparable with X-ray irradiation

    International Nuclear Information System (INIS)

    X-ray radiotherapy activates tumor antigen-specific T-cell responses, and increases in the serum levels of high mobility group box 1 (HMGB1) induced by X-ray irradiation play a pivotal role in activating anti-tumor immunity. Here, we examined whether carbon-ion beams, as well as X-rays, can induce HMGB1 release from human cancer cell lines. The study examined five human cancer cell lines: TE2, KYSE70, A549, NCI-H460 and WiDr. The proportion of cells surviving X- or carbon-ion beam irradiation was assessed in a clonogenic assay. The D10, the dose at which 10% of cells survive, was calculated using a linear–quadratic model. HMGB1 levels in the culture supernatants were assessed by an ELISA. The D10 dose for X-rays in TE2, KYSE70, A549, NCI-H460 and WiDr cells was 2.1, 6.7, 8.0, 4.8 and 7.1 Gy, respectively, whereas that for carbon-ion beams was 0.9, 2.5, 2.7, 1.8 and 3.5 Gy, respectively. X-rays and carbon-ion beams significantly increased HMGB1 levels in the culture supernatants of A549, NCI-H460 and WiDr cells at 72 h post-irradiation with a D10 dose. Furthermore, irradiation with X-rays or carbon-ion beams significantly increased HMGB1 levels in the culture supernatants of all five cell lines at 96 h post-irradiation. There was no significant difference in the amount of HMGB1 induced by X-rays and carbon-ion beams at any time-point (except at 96 h for NCI-H460 cells); thus we conclude that comparable levels of HMGB1 were detected after irradiation with iso-survival doses of X-rays and carbon-ion beams. (author)

  16. Carbon-ion beams effectively induce growth inhibition and apoptosis in human neural stem cells compared with glioblastoma A172 cells

    International Nuclear Information System (INIS)

    Carbon-ion radiotherapy (CIRT) holds promise in the treatment of glioblastoma, an aggressive X-ray–resistant brain tumor. However, since glioblastoma cells show a highly invasive nature, carbon-ion (C-ion) irradiation of normal tissues surrounding the tumor is inevitable. Recent studies have revealed the existence of neural stem cells in the adult brain. Therefore, the damaging effect of C-ion beams on the neural stem cells has to be carefully considered in the treatment planning of CIRT. Here, we investigated the growth and death mode of human neural stem cells (hNSCs) and glioblastoma A172 cells after X-ray or C-ion beam irradiation. The X-ray dose resulting in a 50% growth rate (D50) was 0.8 Gy in hNSCs and 3.0 Gy in A172 cells, while the D50 for C-ion beams was 0.4 Gy in hNSCs and 1.6 Gy in A172 cells; the relative biological effectiveness value of C-ion beams was 2.0 in hNSCs and 1.9 in A172 cells. Importantly, both X-rays and C-ion beams preferentially induced apoptosis, not necrosis, in hNSCs; however, radiation-induced apoptosis was less evident in A172 cells. The apoptosis-susceptible nature of the irradiated hNSCs was associated with prolonged upregulation of phosphorylated p53, whereas the apoptosis-resistant nature of A172 cells was associated with a high basal level of nuclear factor kappa B expression. Taken together, these data indicate that apoptosis is the major cell death pathway in hNSCs after irradiation. The high sensitivity of hNSCs to C-ion beams underscores the importance of careful target volume delineation in the treatment planning of CIRT for glioblastoma. (author)

  17. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  18. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  19. Measurement of large angle fragments induced by 400 MeV n-1 carbon ion beams

    Science.gov (United States)

    Aleksandrov, Andrey; Consiglio, Lucia; De Lellis, Giovanni; Di Crescenzo, Antonia; Lauria, Adele; Montesi, Maria Cristina; Patera, Vincenzo; Sirignano, Chiara; Tioukov, Valeri

    2015-09-01

    The use of carbon ion beams in radiotherapy presents significant advantages when compared to traditional x-ray. In fact, carbon ions deposit their energy inside the human body at the end of their range, the Bragg peak. Unlike x-ray beams, where the energy deposition decreases exponentially inside the irradiated volume, the shape of carbon beams is sharp and focused. Advantages are an increased energy released in the cancer volume while minimizing the irradiation to healthy tissues. Currently, the use of carbon beams is limited by the poor knowledge we have about the effects of the secondary fragments on the irradiated tissues. The secondary particles produced and their angular distribution is crucial to determine the global dose deposition. The knowledge of the flux of secondary particles plays a key role in the real time monitoring of the dose profile in hadron therapy. We present a detector based on nuclear emulsions for fragmentation measurements that performs a sub-micrometric tridimensional spatial resolution, excellent multi-particle separation and large angle track recognition. Nuclear emulsions are assembled in order to realize a hybrid detector (emulsion cloud chamber (ECC)) made of 300 μm nuclear emulsion films alternated with lead as passive material. Data reported here have been obtained by exposing two ECC detectors to the fragments produced by a 400 MeV n-1 12C beam on a composite target at the GSI laboratory in Germany. The ECC was exposed inside a more complex detector, named FIRST, in order to collect fragments with a continuous angular distribution in the range 47°-81° with respect to the beam axis. Results on the angular distribution of fragments as well as their momentum estimations are reported here.

  20. Measurement of large angle fragments induced by 400 MeV n−1 carbon ion beams

    International Nuclear Information System (INIS)

    The use of carbon ion beams in radiotherapy presents significant advantages when compared to traditional x-ray. In fact, carbon ions deposit their energy inside the human body at the end of their range, the Bragg peak. Unlike x-ray beams, where the energy deposition decreases exponentially inside the irradiated volume, the shape of carbon beams is sharp and focused. Advantages are an increased energy released in the cancer volume while minimizing the irradiation to healthy tissues. Currently, the use of carbon beams is limited by the poor knowledge we have about the effects of the secondary fragments on the irradiated tissues. The secondary particles produced and their angular distribution is crucial to determine the global dose deposition. The knowledge of the flux of secondary particles plays a key role in the real time monitoring of the dose profile in hadron therapy.We present a detector based on nuclear emulsions for fragmentation measurements that performs a sub-micrometric tridimensional spatial resolution, excellent multi-particle separation and large angle track recognition. Nuclear emulsions are assembled in order to realize a hybrid detector (emulsion cloud chamber (ECC)) made of 300 μm nuclear emulsion films alternated with lead as passive material.Data reported here have been obtained by exposing two ECC detectors to the fragments produced by a 400 MeV n−1 12C beam on a composite target at the GSI laboratory in Germany. The ECC was exposed inside a more complex detector, named FIRST, in order to collect fragments with a continuous angular distribution in the range 47°–81° with respect to the beam axis. Results on the angular distribution of fragments as well as their momentum estimations are reported here. (paper)

  1. Evaluation of neutron radiation field in carbon ion therapy

    Science.gov (United States)

    Xu, Jun-Kui; Su, You-Wu; Li, Wu-Yuan; Yan, Wei-Wei; Chen, Xi-Meng; Mao, Wang; Pang, Cheng-Guo

    2016-01-01

    Carbon ions have significant advantages in tumor therapy because of their physical and biological properties. In view of the radiation protection, the safety of patients is the most important issue in therapy processes. Therefore, the effects of the secondary particles produced by the carbon ions in the tumor therapy should be carefully considered, especially for the neutrons. In the present work, the neutron radiation field induced by carbon ions was evaluated by using the FLUKA code. The simulated results of neutron energy spectra and neutron dose was found to be in good agreement with the experiment data. In addition, energy deposition of carbon ions and neutrons in tissue-like media was studied, it is found that the secondary neutron energy deposition is not expected to exceed 1% of the carbon ion energy deposition in a typical treatment.

  2. Iodide-induced adsorption of lead(II) ion on a glassy carbon electrode modified with ferroferric oxide nanoparticles

    International Nuclear Information System (INIS)

    Spherical Fe3O4 nanoparticles (NPs) were prepared by hydrothermal synthesis and characterized by scanning electron microscopy and X-ray diffraction. A glassy carbon electrode was modified with such NPs to result in a sensor for Pb(II) that is based on the strong inducing adsorption ability of iodide. The electrode gives a pair of well-defined redox peaks for Pb(II) in pH 5. 0 buffer containing 10 mM concentrations of potassium iodide, with anodic and cathodic peak potentials at -487 mV and -622 mV (vs. Ag/AgCl), respectively. The amperometric response to Pb(II) is linear in the range from 0. 10 to 44 nM, and the detection limit is 40 pM at an SNR of 3. The sensor exhibits high selectivity and reproducibility. (author)

  3. Carbon ion radiotherapy for pancreatic cancer

    International Nuclear Information System (INIS)

    The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world's first heavy ion accelerator complex dedicated to medical use in a hospital environment. Carbon ion therapy offers the potential advantages of improved dose localization and enhanced biological effects. It has been suggested that carbon ion therapy is effective against radioresistant pancreatic cancer. In April 2000, clinical studies examining the treatment of pancreatic cancer with carbon ions were begun at the HIMAC. As of February 2010, 48 patients treated with preoperative carbon ion radiotherapy and 89 patients treated for locally advanced pancreatic cancer were enrolled into the clinical trials. Both protocols are still ongoing. The interim results of these clinical trials suggest that carbon ion radiotherapy provides good local control and offers a survival advantage for patients with otherwise hard to cure pancreatic cancer, without unacceptable morbidity. (author)

  4. Carbon ion radiotherapy for sarcomas

    International Nuclear Information System (INIS)

    Principles of heavy ion therapy, its application to bone and soft tissue sarcomas and outline of its general state are described. The heavy ion therapy has advantages of its high dose distribution to the target and strong biological effect due to the Bragg peak formation and high linear energy transfer, respectively. The authors use carbon ion generated by Heavy Ion Medical Accelerator in Chiba (HIMAC) for the therapy of performance state 0-2 patients with the sarcomas unresectable, diagnosed pathologically, and of 60 y, 45% and teens, 8%) have been treated, whose tumor site has been the pelvis in 73%, volume >600 mL in 63%, tissue type of bone tumor in 70% (where cordoma has amounted to>200 cases). Five-year local control rate is found 71% and survival, 59%. In 175 therapeutically fresh cases with sacral cordoma of median age 67 y, with median clinical target volume 9 cm, treated with median dose 70.4 GyE/16 irradiations, the 8-y local control rate is found to be 69% and survival, 74%, within the median follow-up 54 months; with severe skin ulcer in 2 cases and deterioration of nervous dysfunction in 15 cases; suggesting the therapy is as effective and useful as surgical resection. At present, the therapy is not applicable to Japan health insurance. In the author's hospital, the heavy ion therapy has been conducted to total of >6,000 patients, which amounting to the largest number in the world. Now, 3 Japanese facilities can do the therapy as well and 3 countries in the world.(T.T.)

  5. SPS Ion Induced Desorption Experiment

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    This experiment will give a study about the induced desorption from heavy ion (Indium ion run from week 45 in SPS T4-H8 area) impacting LHC type graphite collimator. 4 different samples are located in the 4 chambers 90° one to each other: pure graphite, graphite with copper coating, graphite with NEG coating, 316LN stainless steal (reference).

  6. Graphene crystal growth by thermal precipitation of focused ion beam induced deposition of carbon precursor via patterned-iron thin layers

    Directory of Open Access Journals (Sweden)

    Rius Gemma

    2014-01-01

    Full Text Available Recently, relevant advances on graphene as a building block of integrated circuits (ICs have been demonstrated. Graphene growth and device fabrication related processing has been steadily and intensively powered due to commercial interest; however, there are many challenges associated with the incorporation of graphene into commercial applications which includes challenges associated with the synthesis of this material. Specifically, the controlled deposition of single layer large single crystal graphene on arbitrary supports, is particularly challenging. Previously, we have reported the first demonstration of the transformation of focused ion beam induced deposition of carbon (FIBID-C into patterned graphitic layers by metal-assisted thermal treatment (Ni foils. In this present work, we continue exploiting the FIBID-C approach as a route for graphene deposition. Here, thin patterned Fe layers are used for the catalysis of graphenization and graphitization. We demonstrate the formation of high quality single and few layer graphene, which evidences, the possibility of using Fe as a catalyst for graphene deposition. The mechanism is understood as the minute precipitation of atomic carbon after supersaturation of some iron carbides formed under a high temperature treatment. As a consequence of the complete wetting of FIBID-C and patterned Fe layers, which enable graphene growth, the as-deposited patterns do not preserve their original shape after the thermal treatment

  7. Carbon nanostructures produced through ion irradiation

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Several nanostructures we produced by ion irradiation have been reviewed in this paper. By using ions to irradiate two ultrahigh molecular weight polyethylene targets respectively, it was found that small fullerenes C20 and C26 were grown, adding two members to the fullerene family. Meanwhile, crystalline diamonds also have been produced by Ar+ ions irradiation of graphite. In the experiment of double ions Ni+ and Ar+ irradiation, nanoscale argon bubbles formed. On the other side, when multi-wall carbon nanotubes were irradiated by C+, many MWCNTs evolved to amorphous carbon nanowires and amorphous carbon nanotubes. And there are possible welding in the crossed nanotubes.

  8. Carbon ion radiotherapy of skull base chondrosarcomas

    International Nuclear Information System (INIS)

    Purpose: To evaluate the effectiveness and toxicity of carbon ion radiotherapy in chondrosarcomas of the skull base. Patients and Methods: Between November 1998 and September 2005, 54 patients with low-grade and intermediate-grade chondrosarcomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft fuer Schwerionenforschung in Darmstadt, Germany. All patients had gross residual tumors after surgery. Median total dose was 60 CGE (weekly fractionation 7 x 3.0 CGE). All patients were followed prospectively in regular intervals after treatment. Local control and overall survival rates were calculated using the Kaplan-Meier method. Toxicity was assessed according to the Common Terminology Criteria (CTCAE v.3.0) and Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) score. Results: Median follow-up was 33 months (range, 3-84 months). Only 2 patients developed local recurrences. The actuarial local control rates were 96.2% and 89.8% at 3 and 4 years; overall survival was 98.2%at 5 years. Only 1 patient developed a mucositis CTCAE Grade 3; the remaining patients did not develop any acute toxicities >CTCAE Grade 2. Five patients developed minor late toxicities (RTOG/EORTC Grades 1-2), including bilateral cataract (n = 1), sensory hearing loss (n = 1), a reduction of growth hormone (n = 1), and asymptomatic radiation-induced white matter changes of the adjacent temporal lobe (n = 2). Grade 3 late toxicity occurred in 1 patient (1.9%) only. Conclusions: Carbon ion RT is an effective treatment for low- and intermediate-grade chondrosarcomas of the skull base offering high local control rates with low toxicity

  9. Ion-Induced Surface Diffusion in Ion Sputtering

    OpenAIRE

    Makeev, Maxim A.; Barabasi, Albert-Laszlo

    1997-01-01

    Ion bombardment is known to enhance surface diffusion and affect the surface morphology. To quantify this phenomenon we calculate the ion-induced diffusion constant and its dependence on the ion energy, flux and angle of incidence. We find that ion bombardment can both enhance and suppress diffusion and that the sign of the diffusion constant depends on the experimental parameters. The effect of ion-induced diffusion on ripple formation and roughening of ion-sputtered surfaces is discussed an...

  10. Enhanced lithium ion storage in TiO2 nanoparticles, induced by sulphur and carbon co-doping

    Science.gov (United States)

    Ivanov, Svetlozar; Barylyak, Adriana; Besaha, Khrystyna; Dimitrova, Anna; Krischok, Stefan; Bund, Andreas; Bobitski, Jaroslav

    2016-09-01

    Sulphur and carbon codoped anatase nanoparticles are synthesized by one-step approach based on interaction between thiourea and metatitanic acid. Electron microscopy shows micrometer-sized randomly distributed crystal aggregates, consisting of many 25-40 nm TiO2 nanoparticles. The obtained phase composition and chemical states of the elements in the structure are analyzed by means of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD shows that after doping the tetragonal anatase structure is preserved. Further data assessment by Rietveld refinement allows detection of a slight increase of the c lattice parameter and volume related to incorporation of the doping elements. XPS confirms the coexistence of both elemental and oxide carbon forms, which are predominantly located on the TiO2 particle surface. According to XPS analysis sulphur occupies titanium sites and the element is present in S6+ sulfate environment. Analysis based on cyclic voltammetry and galvanostatic intermittent titration (GITT) suggests an accelerated Li+ transport in the doped TiO2 structure. The synthesized S and C co-doped anatase has an excellent electrochemical performance in terms of capacity and very fast lithiation kinetics, superior to the non-doped TiO2. The material displays 83% capacity retention for 500 galvanostatic cycles and nearly 100% current efficiency.

  11. Molecular characterization of microbial mutations induced by ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ichida, Hiroyuki [Graduate School of Science and Technology, Chiba University, Matsudo, Chiba 271-8510 (Japan); Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)], E-mail: ichida@riken.jp; Matsuyama, Tomoki [Cellular Biochemistry Laboratory, Discovery Research Institute, RIKEN, Wako, Saitama 351-0198 (Japan); Ryuto, Hiromichi [Accelerator Operation Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Hayashi, Yoriko [Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Fukunishi, Nobuhisa [Accelerator Operation Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Abe, Tomoko [Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Koba, Takato [Graduate School of Science and Technology, Chiba University, Matsudo, Chiba 271-8510 (Japan)

    2008-03-01

    A positive selection system for gene disruption using a sucrose-sensitive transgenic rhizobium was established and used for the molecular characterization of mutations induced by ion beam irradiations. Single nucleotide substitutions, insertions, and deletions were found to occur in the sucrose sensitivity gene, sacB, when the reporter line was irradiated with highly accelerated carbon and iron ion beams. In all of the insertion lines, fragments of essentially the same sequence and of approximately 1188 bp in size were identified in the sacB regions. In the deletion lines, iron ions showed a tendency to induce larger deletions than carbon ions, suggesting that higher LET beams cause larger deletions. We found also that ion beams, particularly 'heavier' ion beams, can produce single gene disruptions and may present an effective alternative to transgenic approaches.

  12. Enhanced lithium ion storage in nanoimprinted carbon

    International Nuclear Information System (INIS)

    Disordered carbons processed from polymers have much higher theoretical capacity as lithium ion battery anode than graphite, but they suffer from large irreversible capacity loss and have poor cyclic performance. Here, a simple process to obtain patterned carbon structure from polyvinylpyrrolidone was demonstrated, combining nanoimprint lithography for patterning and three-step heat treatment process for carbonization. The patterned carbon, without any additional binders or conductive fillers, shows remarkably improved cycling performance as Li-ion battery anode, twice as high as the theoretical value of graphite at 98 cycles. Localized electrochemical strain microscopy reveals the enhanced lithium ion activity at the nanoscale, and the control experiments suggest that the enhancement largely originates from the patterned structure, which improves surface reaction while it helps relieving the internal stress during lithium insertion and extraction. This study provides insight on fabricating patterned carbon architecture by rational design for enhanced electrochemical performance

  13. Enhanced lithium ion storage in nanoimprinted carbon

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peiqi; Chen, Qian Nataly; Li, Jiangyu, E-mail: jjli@uw.edu [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195-2600 (United States); Xie, Shuhong [Faculty of Materials, Optoelectronics and Physics, and Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan University, Xiangtan 411105, Hunan (China); Liu, Xiaoyan [College of Metallurgy and Materials Engineering, and Advanced Materials for Energy Institute, Chongqing University of Science and Technology, Chongqing 401331 (China)

    2015-07-27

    Disordered carbons processed from polymers have much higher theoretical capacity as lithium ion battery anode than graphite, but they suffer from large irreversible capacity loss and have poor cyclic performance. Here, a simple process to obtain patterned carbon structure from polyvinylpyrrolidone was demonstrated, combining nanoimprint lithography for patterning and three-step heat treatment process for carbonization. The patterned carbon, without any additional binders or conductive fillers, shows remarkably improved cycling performance as Li-ion battery anode, twice as high as the theoretical value of graphite at 98 cycles. Localized electrochemical strain microscopy reveals the enhanced lithium ion activity at the nanoscale, and the control experiments suggest that the enhancement largely originates from the patterned structure, which improves surface reaction while it helps relieving the internal stress during lithium insertion and extraction. This study provides insight on fabricating patterned carbon architecture by rational design for enhanced electrochemical performance.

  14. Mutagenic effects of nitrogen and carbon ions on stevia

    International Nuclear Information System (INIS)

    Dry seeds of stevia were implanted by 60∼100 keV nitrogen ion and 75 keV carbon ion with various doses. The biological effects in M1 and mutation in M2 were studied. The results showed that ion beam was able to induce variation on chromosome structure and inhibited mitosis action in root tip cells. The rate of cells with chromosome aberration was increased with the increase of ion beam energy and dose. Energy effects of mitosis were presented between 75 keV and 60, 100 keV. As compared with γ-rays, the effects of ion beam were lower on chromosomal aberration but were higher on frequency of the mutation. The rate of cell with chromosome aberration and M2 useful mutation induced by implantation of carbon ion was higher than those induced by implantation of nitrogen ion. Mutagenic effects of Feng1 x Ri Yuan and of Ri Yuan x Feng2 are higher than that of Ji Ning and Feng2

  15. Mechanical Design of Carbon Ion Optics

    Science.gov (United States)

    Haag, Thomas

    2005-01-01

    Carbon Ion Optics are expected to provide much longer thruster life due to their resistance to sputter erosion. There are a number of different forms of carbon that have been used for fabricating ion thruster optics. The mechanical behavior of carbon is much different than that of most metals, and poses unique design challenges. In order to minimize mission risk, the behavior of carbon must be well understood, and components designed within material limitations. Thermal expansion of the thruster structure must be compatible with thermal expansion of the carbon ion optics. Specially designed interfaces may be needed so that grid gap and aperture alignment are not adversely affected by dissimilar material properties within the thruster. The assembled thruster must be robust and tolerant of launch vibration. The following paper lists some of the characteristics of various carbon materials. Several past ion optics designs are discussed, identifying strengths and weaknesses. Electrostatics and material science are not emphasized so much as the mechanical behavior and integration of grid electrodes into an ion thruster.

  16. Structural disorder in ion irradiated carbon materials

    International Nuclear Information System (INIS)

    The effects of ion irradiation on carbon based materials are reviewed laying emphasis on the well known ability of carbon to have different kinds of bonding configuration with the surrounding atoms. It was found that two kinds of bonding configuration of the carbon atoms are allowed in solid amorphous carbon phases. These rearrange the four valence electrons of carbon into sp2 (trigonal bond) and sp3 (tetrahedral bond) hybridizations. Driving the trigonal carbon fraction (x), the physical and chemical nature of solid carbon materials can change in a dramatic way ranging from metallic (x∼100%) to insulating (x∼0%) through semiconductor properties. The amount of the tetrahedral (or trigonal) carbon atoms can be controlled by ion beam irradiation, using suitable conditions and/or introducing foreign species such as hydrogen or silicon by the implantation technique. In hydrogenated amorphous carbon (a-C:H) and hydrogenated amorphous silicon-carbon alloys (a-Si1-xCx:H), the ion beam effects are able to produce stable and reproducible compounds, achieved by tuning the hydrogen (silicon) concentration with well defined equilibrium curves between the trigonal carbon fraction and hydrogen (silicon) content. Raman spectroscopy and temperature dependent conductivity experiments performed on these alloys suggest clustering effects in samples with high carbon content (x∼0.5) due to the strong binding energy of the C-C double bond with respect to C-Si and Si-Si. Several models and theoretical studies such as the 'random covalent network' (RCN) and molecular dynamics calculations have been used to fit the experimental results. It is shown that, while RCN models are highly inaccurate because of the clustering effects, molecular dynamics calculation data are very close to the experimental measured physical properties and confirm the ability of the trigonal carbon to cluster in graphite-like aggregate

  17. Laser induced fluorescence of trapped molecular ions

    International Nuclear Information System (INIS)

    An experimental apparatus for obtaining the optical spectra of molecular ions is described. The experimental technique includes the use of three dimensional ion trapping, laser induced fluorescence, and gated photon counting methods. The ions, which are produced by electron impact, are confined in a radio-frequency quadrupole ion trap of cylindrical design. Because the quadrupole ion trap allows mass selection of the molecular ion desired for study, the analysis of the spectra obtained is greatly simplified. The ion trap also confines the ions to a region easily probed by a laser beam. 18 references

  18. Silicon/Carbon Nanotube/BaTiO3 Nanocomposite Anode: Evidence for Enhanced Lithium-Ion Mobility Induced by the Local Piezoelectric Potential.

    Science.gov (United States)

    Lee, Byoung-Sun; Yoon, Jihyun; Jung, Changhoon; Kim, Dong Young; Jeon, Seung-Yeol; Kim, Ki-Hong; Park, Jun-Ho; Park, Hosang; Lee, Kang Hee; Kang, Yoon-Sok; Park, Jin-Hwan; Jung, Heechul; Yu, Woong-Ryeol; Doo, Seok-Gwang

    2016-02-23

    We report on the synergetic effects of silicon (Si) and BaTiO3 (BTO) for applications as the anode of Li-ion batteries. The large expansion of Si during lithiation was exploited as an energy source via piezoelectric BTO nanoparticles. Si and BTO nanoparticles were dispersed in a matrix consisting of multiwalled carbon nanotubes (CNTs) using a high-energy ball-milling process. The mechanical stress resulting from the expansion of Si was transferred via the CNT matrix to the BTO, which can be poled, so that a piezoelectric potential is generated. We found that this local piezoelectric potential can improve the electrochemical performance of the Si/CNT/BTO nanocomposite anodes. Experimental measurements and simulation results support the increased mobility of Li-ions due to the local piezoelectric potential. PMID:26815662

  19. Characterization of ion-beam-induced carbon deposition on WC-Co hard metal by microhardness, scratch and abrasive wear tests

    International Nuclear Information System (INIS)

    Diamond-like ion-beam-deposited carbon (i-C) layers were obtained on WC-Co cemented carbide using a mass-separated 12C beam at an energy of 500 eV and a deposition rate of 3 A s-1. The mechanical properties of these layers were probed using microhardness and scratch tests and abrasive wear measurements. All these tests revealed that the depositions possess an extremely high hardness and good adhesion to the substrate. In particular, a hardness of 75 GPa was obtained, which is considerably higher than that found on i-C films involving hydrogen. (orig.)

  20. Carbon Mineralization Using Phosphate and Silicate Ions

    Science.gov (United States)

    Gokturk, H.

    2013-12-01

    Carbon dioxide (CO2) reduction from combustion of fossil fuels has become an urgent concern for the society due to marked increase in weather related natural disasters and other negative consequences of global warming. CO2 is a highly stable molecule which does not readily interact with other neutral molecules. However it is more responsive to ions due to charge versus quadrupole interaction [1-2]. Ions can be created by dissolving a salt in water and then aerosolizing the solution. This approach gives CO2 molecules a chance to interact with the hydrated salt ions over the large surface area of the aerosol. Ion containing aerosols exist in nature, an example being sea spray particles generated by breaking waves. Such particles contain singly and doubly charged salt ions including Na+, Cl-, Mg++ and SO4--. Depending on the proximity of CO2 to the ion, interaction energy can be significantly higher than the thermal energy of the aerosol. For example, an interaction energy of 0.6 eV is obtained with the sulfate (SO4--) ion when CO2 is the nearest neighbor [2]. In this research interaction between CO2 and ions which carry higher charges are investigated. The molecules selected for the study are triply charged phosphate (PO4---) ions and quadruply charged silicate (SiO4----) ions. Examples of salts which contain such molecules are potassium phosphate (K3PO4) and sodium orthosilicate (Na4SiO4). The research has been carried out with first principle quantum mechanical calculations using the Density Functional Theory method with B3LYP functional and Pople type basis sets augmented with polarization and diffuse functions. Atomic models consist of the selected ions surrounded by water and CO2 molecules. Similar to the results obtained with singly and doubly charged ions [1-2], phosphate and silicate ions attract CO2 molecules. Energy of interaction between the ion and CO2 is 1.6 eV for the phosphate ion and 3.3 eV for the silicate ion. Hence one can expect that the selected

  1. He+ ion induced hydrogen loss from materials

    International Nuclear Information System (INIS)

    Ion-beam analysis technique like elastic recoil detection analysis is a powerful tool for simultaneous and absolute quantification of H and its isotopes in a non-destructive fashion. We report on room temperature hydrogen loss from three different class of materials, viz. dc glow discharge deposited diamond like carbon (DLC) films on Si, KH2PO4 (KDP) and organic lipid films deposited on Si. Hydrogen loss is observed during elastic recoil detection analysis measurements using 1.2 to 1.5 MeV He+ ions. This is an important issue as it may lead to erroneous estimates of the actual H content of materials. The H loss data have been fitted using a phenomenological model which considers ion induced bond-breaking along its trajectory, followed by formation and release of molecular hydrogen from materials. Based on the fitted results, we have tried to address the universality of the H loss phenomenon. For the DLC samples, a strong dependence of H loss on the film microstructure and the H contents has been observed. It is also observed that in general, H loss is a material dependent property and is difficult to predict any universal behaviour for different materials. (author)

  2. Ion induced transformation of polymer films into diamond-like carbon incorporating silver nano particles; Ioneninduzierte Umwandlung von Polymerschichten zu diamantaehnlichem Kohlenstoff mit darin enthaltenen Silber-Nanopartikeln

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Florian P.

    2010-03-26

    Silver containing diamond-like carbon (DLC) is an interesting material for medical engineering from several points of view. On the one hand DLC provides high mechanical robustness. It can be used as biocompatible and wear resistant coating for joint replacing implants. On the other hand silver has antimicrobial properties, which could reduce post-operative inflammations. However conventional production of Ag-DLC by co-deposition of silver and carbon in a plasma process is problematic since it does not allow for a separate control of nano particle morphology and matrix properties. In this work an alternative production method has been developed to circumvent this problem. In metall-DLC-production by ion implantation into a nano composite, silver nano particles are initially formed in solution and then incorporated within a polymer matrix. Finally the polymer is transformed into DLC by ion implantation. The aspects and single steps of this method were investigated with regard to the resulting material's properties. The goal was to design an economically relevant deposition method. Based on experimental results a model of the transformation process has been established, which has also been implemented in a computer simulation. Finally the antibacterial properties of the material have been checked in a biomedical test. Here a bacterial killing rate of 90% could be achieved. (orig.)

  3. F values for isoelectronic ions of carbon

    Science.gov (United States)

    Ganas, P. S.

    1981-10-01

    An analytic atomic independent particle model is used to generate wave functions for the valence and excited states of isoelectronic ions of carbon up to Z = 20. Using these wave functions in conjunction with the Born approximation and the Russell-Saunders LS-coupling scheme, f values are calculated for various transitions from the 2p2(3P0) ground state. The results are compared with those from other works.

  4. Precise measurement of prompt photon emission for carbon ion therapy

    CERN Document Server

    Agodi, C; Cirrone, G A P; Collamati, F; Cuttone, G; De Lucia, E; De Napoli, M; Di Domenico, A; Faccini, R; Ferroni, F; Fiore, S; Gauzzi, P; Iarocci, E; Marafini, M; Mattei, I; Paoloni, A; Patera, V; Piersanti, L; Romano, F; Sarti, A; Sciubba, A; Voena, C

    2011-01-01

    Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments is still a matter of research. A possible technique exploits the information provided by single photon emission from nuclear decays induced by the irradiation. This paper reports the measurements of the spectrum and rate of such photons produced from the interaction of a 80 MeV/u fully stripped carbon ion beam at the Laboratori Nazionali del Sud of INFN, Catania, with a Poly-methyl methacrylate target. The differential production rate for photons with energy E > 2 MeV and emitted at 90 degree is found to be $dN_{\\gamma}/(dN_C d\\Omega)=(2.92\\pm 0.19)\\times 10^{-2}$sr$^{-1}$.

  5. Recent innovations in carbon-ion radiotherapy

    International Nuclear Information System (INIS)

    In the last few years, hospital-based facilities for carbon-ion radiotherapy are being constructed and proposed in Europe and Asia. During the next few years, several new facilities will be opened for carbon-ion radiotherapy in the world. These facilities in operation or under construction are categorized in two types by the beam shaping method used. One is the passive beam shaping method that is mainly improved and systematized for routine clinical use at Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. The other method is active beam shaping which is also known as beam scanning adopted at Gesellschaft fur Schwerionenforschung (GSI)/Heidelberg Ion Therapy Center (HIT), Germany. In this paper an overview of some technical aspects for beam shaping is reported. The technique of passive beam shaping is established for stable clinical application and has clinical result of over 4000 patients in HIMAC. In contrast, clinical experience of active beam shaping is about 400 patients, and there is no clinical experience to respiratory moving target. A great advantage of the active beam shaping method is patient-specific collimator-less and compensator-less treatment. This may be an interesting potential for adaptive radiotherapy. (author)

  6. Treatment planning system for carbon ion radiotherapy

    International Nuclear Information System (INIS)

    This paper describes the treatment planning (TP) and its peripheral system for carbon ion therapy that has been developed and in clinical use in recent two years at our institution. A new treatment planning system which is FOCUS customized to our irradiation system will be launched in clinical use soon. A new DICOM based PACS has been developed and in use. Now MRI, PET images are ready to be utilized for patient definition with image fusion functionality of radiotherapy TP. We implemented the exchange functionality of TP data specified by RTOG 3D QA Center in FOCUS, Pinnacle3 and heavy ion TP. Target volume and normal structure contours and dose distributions are exchangeable. A database system of carbon ion therapy dedicated to analysis of therapy data has been designed and implemented. All accessible planning data and treatment records of more than 1000 patients treated for seven and half years have been archived. The system has a DICOM RT sever and a database for miscellaneous text data. Limited numbers of private attributes were introduced for ion therapy specific objects. On-line as well as manual registration along with edit functionalities is prepared. Standard web browser is used to search and retrieve information. A DICOM RT viewer has been developed to view and retrieve RT images, dose distributions and structure set. These system described above are all designed to conform to the up-to-date standards of radiation therapy so as to be bases of the future development of the therapy at our institution. (author)

  7. Reactions of carbon cluster ions stored in an RF trap

    International Nuclear Information System (INIS)

    Reactions of carbon cluster ions with O2 were studied by using an RF ion trap in which cluster ions of specific size produced by laser ablation could be stored selectively. Reaction rate constants for positive and negative carbon cluster ions were estimated. In the case of the positive cluster ions, these were consistent with the previous experimental results using FTMS. Negative carbon cluster ions C-n (n=4-8) were much less reactive than positive cluster ions. The CnO- products were seen only in n=4 and 6. (orig.)

  8. Molecular analysis of heavy ion induced mutations in the budding yeast

    International Nuclear Information System (INIS)

    This study is intended to elucidate the molecular mechanism of the mutagenesis caused by High-linear energy transfer (LET) ion beam. The frequency of DNA double stranded breaks (DSBs) was estimated by agarose gel electrophoresis. Moreover, the mutation sites of ura3 mutants were determined by DNA sequencing. The yeast cells were irradiated with carbon ions (12C5+; 290 MeV) with the dose 50 to 200 Gy. Carbon ion beam was generated from synchrotron in HIMAC. The carbon ion beams at 100 Gy generate mutations 10.3 - fold more than spontaneous mutation. The mutation frequency increased consistently with LET. This result indicates the high LET ion beam is more mutagenic than low LET ion beam. The remarkable feature of yeast mutations induced by carbon ions was that the mutation sites were localized near the linker regions of nucleosomes, whereas mutations induced by gamma-ray irradiation were located uniformly throughout the gene. (author)

  9. Kinetics of ion beam deposition of carbon at room temperature

    International Nuclear Information System (INIS)

    Growth rates of carbon films grown by ion beam deposition using methane gas were measured in situ as a function of deposition conditions. The methane pressure dependence of the growth rate was used to measure the cross-section for charge exchange. Variations in deposition rate per incident energetic particle found for each ion energy were related to ion current density. It was found that rates of growth per incident energetic specie were (i) largest for the smallest current densities, (ii) decreased monotonically with increasing current density, and (iii) were consistently larger than can be explained by deposition directly from the energetic flux alone. These observations were interpreted in terms of irradiation-induced surface interactions which promote chemisorption of methane physisorbed from the ambient atmosphere. (orig.)

  10. Carbonate ions and arsenic dissolution by groundwater

    Science.gov (United States)

    Kim, M.-J.; Nriagu, J.; Haack, S.

    2000-01-01

    Samples of Marshall Sandstone, a major source of groundwater with elevated arsenic levels in southeast Michigan, were exposed to bicarbonate ion under controlled chemical conditions. In particular, effects of pH and redox conditions on arsenic release were evaluated. The release of arsenic from the aquifer rock was strongly related to the bicarbonate concentration in the leaching solution. The results obtained suggest that the carbonation of arsenic sulfide minerals, including orpiment (As2S3) and realgar (As2S2), is an important process in leaching arsenic into groundwater under anaerobic conditions. The arseno-carbonate complexes formed, believed to be As(CO3)2-, As(CO3)(OH)2-, and AsCO3+, are stable in groundwater. The reaction of ferrous ion with the thioarsenite from carbonation process can result in the formation of arsenopyrite which is a common mineral in arsenic-rich aquifers.Samples of Marshall Sandstone, a major source of groundwater with elevated arsenic levels in southeast Michigan, were exposed to bicarbonate ion under controlled chemical conditions. In particular, effects of pH and redox conditions on arsenic release were evaluated. The release of arsenic from the aquifer rock was strongly related to the bicarbonate concentration in the leaching solution. The results obtained suggest that the carbonation of arsenic sulfide minerals, including orpiment (As2S3) and realgar (As2S2), is an important process in leaching arsenic into groundwater under anaerobic conditions. The arseno-carbonate complexes formed, believed to be As(CO3)2-, As(CO3)(OH)2-, and AsCO3+, are stable in groundwater. The reaction of ferrous ion with the thioarsenite from carbonation process can result in the formation of arsenopyrite which is a common mineral in arsenic-rich aquifers.The role of bicarbonate in leaching arsenic into groundwater was investigated by conducting batch experiments using core samples of Marshall Sandstone from southeast Michigan and different bicarbonate

  11. Carbonate Ion Effects on Coccolith Carbon and Oxygen Isotopes

    Science.gov (United States)

    Ziveri, P.; Probert, I.; Stoll, H. M.

    2006-12-01

    conclusively distinguished whether C is taken up only as CO2 by passive diffusion or also by active transport of CO2 or HCO^{3-} . In reality, the patterns of stable isotopic variations in coccoliths may provide more constraints for unraveling the cellular C transport and the calcification mechanisms. We will present latest findings on these issues, both from culture experiments and sediment traps located in the Bay of Bengal. Coccolith species separated from these sediment traps also show evidence of carbonate ion effects.

  12. Investigation of physiologically active products obtained from carbon-ion irradiated actinomycetes

    International Nuclear Information System (INIS)

    Charged particles such as carbon-ions are superior to X-rays or gamma-rays in the physical and biological characteristics. The propose research project is aimed to provide new insights on antibiotic development. Product(s) from carbon-ion irradiated microorganera suppressed growth of human leukemia cells and mammary tumor cells. This product(s) induced apoptosis in human leukemia cells. We suggested that carbon-ion irradiated actinomycetes produce antitumor active product(s) for leukemia cells and mammary tumor cells. (author)

  13. Molecular analysis of heavy ion induced mutations in the budding yeast

    International Nuclear Information System (INIS)

    The aim of this study is to elucidate the relation between linear energy transfer (LET) and mutagenesis. Carbon ion beams with varied LET generated by Heavy Ion Medical Accelerator in Chiba (HIMAC) synchrotron were irradiated to several types of yeast cells, and we examined the survival rate and mutation frequencies. The results showed that the survival rates were reduced along with the LET, while the mutation frequencies were enhanced along with the LET, and the mutation frequencies increased consistently with LET. The sequencing analysis of mutations showed that the low LET carbon ion beams induced more deletion and insertion mutations than high LET carbon ion beams did. Furthermore, we also examined the gene expression analysis of RAD50, RAD52 and OGG1 after ion beam radiation to cells. The result indicated that the high-LET carbon-ion beams induced the expression of RAD50 gene. (author)

  14. Carbon ion radiotherapy for uveal melanoma

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the applicability of carbon ion beams in the treatment of choroidal melanoma, with regard to normal tissue morbidity and local tumor control. Between January 2001 and August 2006, 67 patients with locally advanced or unfavorable-site choroidal melanoma were enrolled in a phase I/II clinical trial of carbon-ion radiotherapy (C-ion RT) at the National Institute of Radiological Sciences (NIRS). Primary endpoint of this study was normal tissue morbidity and secondary endpoints were local tumor control and patient survival. Fifty-nine of the patients were followed up for more than 6 months and analyzed. Twenty-three patients (39%) developed neovascular glaucoma (NVG) and 3 of them underwent enucleation because of the eye pain due to elevated intraocular pressure. The incidence of neovascular glaucoma was dependent on tumor size and site. Five patients had died by the date of analysis, 3 of distant metastasis and 2 of intercurrent diseases. All patients but one, who developed marginal recurrence, were controlled locally. Eight patients developed distant metastasis, 5 in the liver and 3 in the lung. Three-year overall survival, disease-free survival, and local control rates were 87.1%, 81.6%, and 98.0%, respectively. No apparent dose-response relationship was observed either in tumor control or in normal tissue morbidity with the dose range applied. C-ion RT can be applied to choroidal melanoma with an acceptable morbidity and sufficient anti-tumor effect, even in tumors of unfavorable size or site. (author)

  15. Carbon Ion Radiotherapy for Skull Base Chordoma

    OpenAIRE

    Mizoe, Jun–etsu; Hasegawa, Azusa; Takagi, Ryo; Bessho, Hiroki; Onda, Takeshi; Tsujii, Hirohiko

    2009-01-01

    Objective: To present the results of the clinical study of carbon ion radiotherapy (CIRT) for skull base and paracervical spine tumors at the National Institute of Radiological Sciences in Chiba, Japan. Methods: The study is comprised of three protocols: a pilot study, a phase I/II dose escalation study, and a phase II study. All the patients were treated by 16 fractions for 4 weeks with total doses of 48.0, 52.8, 57.6, and 60.8 Gy equivalents (GyE). Results: As a result of the dose escalatio...

  16. Intensive irradiation of carbon nanotubes by Si ion beam

    Institute of Scientific and Technical Information of China (English)

    NI Zhichun; LI Qintao; YAN Long; GONG Jinlong; ZHU Dezhang; ZHU Zhiyuan

    2007-01-01

    Multi-walled carbon nanotubes were irradiated with 40 keV Si ion beam to a dose of 1×1017 cm-2. The multiple-way carbon nanowire junctions and the Si doping in carbon nanowires were realized. Moreover, the formation processes of carbon nanowire junctions and the corresponding mechanism were studied.

  17. Shunting arc plasma source for pure carbon ion beama)

    Science.gov (United States)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm2 at the peak of the pulse.

  18. Shunting arc plasma source for pure carbon ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y. [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2012-02-15

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

  19. Shunting arc plasma source for pure carbon ion beam.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse. PMID:22380206

  20. The morphology and structure of one-dimensional carbon-carbon composite under high-fluence ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Andrianova, N.N.; Borisov, A.M. [Institute of Nuclear Physics, Moscow State University, Leninsky Gori, 119991 Moscow (Russian Federation); Mashkova, E.S. [Institute of Nuclear Physics, Moscow State University, Leninsky Gori, 119991 Moscow (Russian Federation)], E-mail: es_mashkova@mail.ru; Virgiliev, Yu.S. [NIIgraphite, Electrodnaya 2, 111141 Moscow (Russian Federation)

    2009-08-15

    The temperature dependences of the ion-induced electron emission yield {gamma}(T), the crystal structure, and the morphology of a surface layer of the one-dimensional carbon fiber composite KUP-VM (1D) under high-fluence (10{sup 18}-10{sup 19} ion/cm{sup 2}) irradiation with 30 keV N{sub 2}{sup +} ions at normal incidence both perpendicular and parallel to the fiber directions have been studied. The target temperature has been varied during continuous irradiation from T = -180 to 400 deg. C. The surface analysis has been performed by the RHEED, SEM and RBS techniques. The surface microgeometry was studied using laser goniophotometry (LGP). It has been found that ion irradiation results in a loss of anisotropy of the surface layer structure because of amorphization at room temperature or recrystallization at a temperature higher than the ion-induced annealing temperature. The fiber morphology anisotropy remains under ion irradiation.

  1. The morphology and structure of one-dimensional carbon-carbon composite under high-fluence ion irradiation

    International Nuclear Information System (INIS)

    The temperature dependences of the ion-induced electron emission yield γ(T), the crystal structure, and the morphology of a surface layer of the one-dimensional carbon fiber composite KUP-VM (1D) under high-fluence (1018-1019 ion/cm2) irradiation with 30 keV N2+ ions at normal incidence both perpendicular and parallel to the fiber directions have been studied. The target temperature has been varied during continuous irradiation from T = -180 to 400 deg. C. The surface analysis has been performed by the RHEED, SEM and RBS techniques. The surface microgeometry was studied using laser goniophotometry (LGP). It has been found that ion irradiation results in a loss of anisotropy of the surface layer structure because of amorphization at room temperature or recrystallization at a temperature higher than the ion-induced annealing temperature. The fiber morphology anisotropy remains under ion irradiation.

  2. Production of defects in supported carbon nanotubes under ion irradiation

    International Nuclear Information System (INIS)

    Ion irradiation of individual carbon nanotubes deposited on substrates may be used for making metallic nanowires and studying effects of disorder on the electronic transport in low-dimensional systems. In order to understand the basic physical mechanisms of radiation damage production in supported nanotubes, we employ molecular dynamics and simulate ion impacts on nanotubes lying on different substrates, such as platinum and graphite. We show that defect production depends on the type of the substrate and that the damage is higher for metallic heavy-atom substrates than for light-atom substrates, since in the former case sputtered metal atoms and backscattered recoils produce extra damage in the nanotube. We further study the behavior of defects upon high-temperature annealing and demonstrate that although ions may severely damage nanotubes in a local region, the nanotube carbon network can heal such a strong localized damage due to defect migration and dangling-bond saturation. We also show that after annealing the residual damage in nanotubes is independent of the substrate type. We predict the pinning of nanotubes to substrates through nanotube-substrate bonds that appear near irradiation-induced defects

  3. Ion irradiation induced direct damage to DNA

    CERN Document Server

    Wang, Wei; Su, Wenhui

    2008-01-01

    Ion beams have been widely applied in a few biological research fields such as radioactive breeding, health protection, and tumor therapy. Up to now many interesting and impressive achievements in biology and agriculture have been made. Over the past several decades, scientists in biology, physics, and chemistry have pursued investigations focused on understanding the mechanisms of these radiobiological effects of ion beams. From the chemical point of view, these effects are due to the ion irradiation induced biomolecular damage, direct or indirect. In this review, we will present a chemical overview of the direct effects of ion irradiation upon DNA and its components, based on a review of literature combined with recent experimental results. It is suggested that, under ion bombardment, a DNA molecule undergoes a variety of processes, including radical formation, atomic displacement, intramolecular bond-scissions, emission of fragments, fragment recombination and molecular crosslink, which may lead to genetic...

  4. Heavy ion induced mutation in arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  5. Monte Carlo simulation of carbon ion radiotherapy for Human Eye

    CERN Document Server

    Pang, Chengguo; Yao, Zeen; Xu, Junkui; Li, Wuyuan; Yuan, Jiao

    2014-01-01

    Carbon ion is the mostly common used particle in heavy ion radiotherapy. In this paper, carbon ion dose in tumor treatment for human eye was simulated with FLUKA code, 80 MeV/u carbon beam was irradiated into the human eye from two directions, The first is from the lateral-forward direction which was a typical therapeutic condition, maximum dose was deposited in the tumor volume. The second one was that beam irradiated into eyes from the forward direction which may cause certain medical accident. The calculated results are compared with other reports. The agreement indicates that this method can be used for treatment plan in heavy ion radiotherapy.

  6. Electron spin resonance investigations on ion beam irradiated single-wall carbon nanotubes

    International Nuclear Information System (INIS)

    ESR investigations on single-wall carbon nanotubes irradiated with accelerated protons, helium ions, and neon ions are reported. All spectra were accurately simulated assuming that the resonance line is a convolution of up to 4 lines originating from catalyst residues, amorphous carbon, and electrons delocalized over the conducting domains of nanotubes. The faint line observed in irradiated nanotubes at g > 2.25 was assigned to magnetic impurities. However, there are no sufficient data to confirm that this line is connected to radiation-induced magnetism in carbon nanotubes. The generation of paramagnetic defects due to the bombardment of single-wall carbon nanotubes by accelerated ions is reported. These data correlate with previous Raman and thermal investigations on the same single-wall carbon nanotubes and reveals their sensitivity to ionizing radiation. The temperature dependence of ESR spectra in the range 25-250 K was used to identify the components of the ESR spectra

  7. Nuclear fission induced by heavy ions

    International Nuclear Information System (INIS)

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  9. Specific gene mutations induced by heavy ions

    International Nuclear Information System (INIS)

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

  10. Ion-Induced Nucleation of Cesium Vapor

    Czech Academy of Sciences Publication Activity Database

    Uchtmann, H.; Katz, J. L.; Ždímal, Vladimír

    Vol. 2. Budapest, 2004, S103-S104. [European Aerosol Conference EAC 2004. Budapest (HU), 06.09.2004-10.09.2004] Grant ostatní: NATO(XX) SA979351/6993/FP Institutional research plan: CEZ:AV0Z4072921 Keywords : fundamental aerosol physics * ion-induced nucleation Subject RIV: CF - Physical ; Theoretical Chemistry

  11. Electrochemical properties of carbon materials implanted with high energy heavy ions

    International Nuclear Information System (INIS)

    Carbon materials have some allotropes such as diamond, graphite and amorphous carbon. These allotropes show significantly different natures depending on their structures. Ion implantation has two different effects on the modification of material surface layers, that is, the structural modification induced by the energy radiation accompanying ion beam bombardment, and the composition change introduced by doping surface layers with different elements. Carbon materials have been used as fuel, tools, electrical conductors, chemical instruments, electrochemical electrodes and composite materials because of their natures, such as the brightness and hardness of diamond and the chemical stability and electro-conductivity of black carbon. For all these uses, the surface properties are important, accordingly, ion implantation is an important technique for modifying the surface layers. In this paper, the main features of the ion implantation on the surface modification of diamond and glassy carbon substrates, and the chemical and electrochemical properties of glassy carbon implanted with various elements are reported. The electrode characteristics of ion-implanted glassy carbon are affected by the composition change and the change to amorphous form. (K.I.)

  12. Modified carbon black materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Kostecki, Robert; Richardson, Thomas; Boesenberg, Ulrike; Pollak, Elad; Lux, Simon

    2016-06-14

    A lithium (Li) ion battery comprising a cathode, a separator, an organic electrolyte, an anode, and a carbon black conductive additive, wherein the carbon black has been heated treated in a CO.sub.2 gas environment at a temperature range of between 875-925 degrees Celsius for a time range of between 50 to 70 minutes to oxidize the carbon black and reduce an electrochemical reactivity of the carbon black towards the organic electrolyte.

  13. Relative biological effectiveness of carbon ions for tumor control, acute skin damage and late radiation-induced fibrosis in a mouse model

    DEFF Research Database (Denmark)

    Sørensen, Brita Singers; Horsman, Michael Robert; Alsner, Jan;

    2015-01-01

    right hind limb were irradiated with single fractions of either photons, or 12 C ions using a 30-mm spread-out Bragg peak. The endpoint of the study was local control (no tumor recurrence within 90 days). For the acute skin reaction, non-tumor bearing CDF1 mice were irradiated with a comparable...

  14. Role of Hypoxia-inducible factor-1 and its target genes in human lung adenocarcinoma cells after photon- versus carbon ion irradiation

    International Nuclear Information System (INIS)

    Exposed to hypoxia tumor cells are notably resistant to photon irradiation. The hypoxiainducible transcription factor 1α (HIF-1α) seems to play a fundamental role in this resistance, while its role after heavy-ion beam remains unknown. The intention of this study was to determine how A549-cells (non-small-cell lung carcinoma) react in different oxygenation states after irradiation with photons or heavy ions, particularly in regards to their expression of HIF-1 target genes. Resistance of hypoxic A549 cells after photon irradiation was documented by cellular and clonogenic survival. In contrast, cellular survival after heavy-ion irradiation in hypoxic cells was not elevated to normoxic cells. Among the oxygen dependent regulation of HIF-1 target genes, gene expression analyses showed an increased expression of GLUT-1, LDH-A, PDK-1 and VEGF after photon irradiation but not after heavy-ion irradiation after 48 hours in normoxic cells. As expected, CDKN1A as inhibitor of cell cycle progression showed higher expression after both radiation forms; interestingly CDKN1A was also in an oxygen dependent manner lightly upregulated. In western blot analyses we demonstrated a significant increase of HIF-1 and GLUT-1 caused by hypoxia, but only a tendency of increased protein level in hypoxia after photon irradiation and no changes after heavy-ion irradiation. Significantly higher protein level of secreted VEGF-A could be measured 72 hours after photon irradiation in normoxic cells by ELISA analyses. Controversially discussed, I could not detect an association between HIF-1 and SCF or Trx-1 in A549-cells in this study. Whereas Trx-1-expression was neither influenced by changed oxygen partial pressure nor irradiation, I could show increased SCF mRNA by quantitative Real Time-PCR and secreted protein level by ELISA after photon irradiation independent of oxygen state. In summary, this study showed that HIF-1 and its target genes (GLUT-1, LDHA; PDK, VEGF) and also SCF was

  15. Ion irradiation induced surface modification studies of polymers using Spmb

    International Nuclear Information System (INIS)

    Various types of scanning probe microscopy (SPM) techniques: atomic force microscopy (AFM) (contact and tapping in height and amplitude mode), scanning tunnelling microscopy (STM) and conducting atomic force microscopy (C-AFM) are used for studying ion beam induced surface modifications, nanostructure/cluster formation and disintegration in polymers and similar soft carbon based materials. In the present study, the results of studies on four materials, namely (A) methyltriethoxysilane/phenyltriethoxysilane (MTES/PTES) based gel, (B) triethoxisilane (TH) based gel, (C) highly oriented pyrolytic graphite (HOPG) bulk and (D) fullerene (C60) thin films are discussed. In the case of Si based gels prepared from pre-cursors containing organic groups (MTES/PTES), hillocks are observed at the surface and their size decreases from 70 to 25 nm with increasing fluence, whereas, in the case of a gel with a stoichiometry SiO1.25H1, prepared from TH, an increases in the size of hillocks is observed. Hillocks are also formed at the surface of HOPG irradiated with 120 MeV Au beam at a low fluence, whereas, formation of craters and a re-organisation of surface features is observed at a higher fluence. In the case of C60 films, 120 MeV Au ion irradiation induces the formation of conducting ion tracks, which is attributed to the transformation from insulating C60 to conducting graphite like carbon

  16. Ion implantation inhibits cell attachment to glassy polymeric carbon

    International Nuclear Information System (INIS)

    Implantation of MeV gold, oxygen, carbon ions into GPC alters the surface topography of GPC and enhances the already strong tendency for cells to attach to GPC. We have shown that implantation of silver ions near the surface strongly inhibits cell growth on GPC. Both enhanced adhesion of and inhibition of cell growth are desirable improvements on cardiac implants that have long been successfully fabricated from biocompatible glassy polymeric carbon (GPC). In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that ion beam assisted deposition (IBAD) of silver, as well as silver ion bombardment, can favorably influence the surface of GPC for biomedical applications

  17. Electron string ion sources for carbon ion cancer therapy accelerators

    Science.gov (United States)

    Boytsov, A. Yu.; Donets, D. E.; Donets, E. D.; Donets, E. E.; Katagiri, K.; Noda, K.; Ponkin, D. O.; Ramzdorf, A. Yu.; Salnikov, V. V.; Shutov, V. B.

    2015-08-01

    The type of the Electron String Ion Sources (ESIS) is considered to be the appropriate one to produce pulsed C4+ and C6+ ion beams for cancer therapy accelerators. In fact, the new test ESIS Krion-6T already now provides more than 1010 C4+ ions per pulse and about 5 × 109 C6+ ions per pulse. Such ion sources could be suitable to apply at synchrotrons. It has also been found that Krion-6T can provide more than 1011 C6+ ions per second at the 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. ESIS can be also a suitable type of ion source to produce the 11C radioactive ion beams. A specialized cryogenic cell was experimentally tested at the Krion-2M ESIS for pulse injection of gaseous species into the electron string. It has been shown in experiments with stable methane that the total conversion efficiency of methane molecules to C4+ ions reached 5%÷10%. For cancer therapy with simultaneous irradiation and precise dose control (positron emission tomography) by means of 11C, transporting to the tumor with the primary accelerated 11C4+ beam, this efficiency is preliminarily considered to be large enough to produce the 11C4+ beam from radioactive methane and to inject this beam into synchrotrons.

  18. Electron string ion sources for carbon ion cancer therapy accelerators

    CERN Document Server

    Boytsov, A Yu; Donets, E D; Donets, E E; Katagiri, K; Noda, K; Ponkin, D O; Ramzdorf, A Yu; Salnikov, V V; Shutov, V B

    2015-01-01

    The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ions per pulse and about 5*10^9 C6+ ions per pulse. Such ion sources could be suitable for application at synchrotrons. It was also found, that Krion-6T can provide more than 10^11 C6+ ions per second at 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. As for production of 11C radioactive ion beams ESIS can be the most economic kind of ion source. To proof that the special cryogenic cell for pulse injection of gaseous species into electron string was successfully tested using the ESIS Krion-2M.

  19. Innershell ionization by fast protons, alpha particles and carbon ions

    International Nuclear Information System (INIS)

    The subject of this thesis is the study of inner-shell excitations of atoms induced by fast charged particle collisions. A new method is described for measuring the spectrum of delta-electrons emitted by 208Pb after excitation by 15 MeV protons or 50 MeV alpha particles. Experimental equipment is described. Results of both experiments are presented and compared with PWBA models and with calculations based on a semi-classical approximation. The small-impact-parameter ionization probabilities obtained are then compared with literature. Also small-impact-parameter measurements done with 100 MeV carbon ions are described. Besides K-shell measurements, the author also presents L-subshell ionization probability results for Pb. An appendix is added in which energy straggling problems in solid targets are treated. (Auth./G.J.P.)

  20. Study on neutron radiation field of carbon ions therapy

    CERN Document Server

    Xu, Jun-Kui; Li, Wu-Yuan; Yan, Wei-Wei; Chen, Xi-Meng; Mao, Wang; Pang, Cheng-Guo

    2015-01-01

    Carbon ions offer significant advantages for deep-seated local tumors therapy due to their physical and biological properties. Secondary particles, especially neutrons caused by heavy ion reactions should be carefully considered in treatment process and radiation protection. For radiation protection purposes, the FLUKA Code was used in order to evaluate the radiation field at deep tumor therapy room of HIRFL in this paper. The neutron energy spectra, neutron dose and energy deposition of carbon ion and neutron in tissue-like media was studied for bombardment of solid water target by 430MeV/u C ions. It is found that the calculated neutron dose have a good agreement with the experimental date, and the secondary neutron dose may not exceed one in a thousand of the carbon ions dose at Bragg peak area in tissue-like media.

  1. WIMP detection and slow ion dynamics in carbon nanotube arrays

    OpenAIRE

    Cavoto, G.; Cirillo, E. N. M.; Cocina, F.; Ferretti, J.; Polosa, A.D.

    2016-01-01

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy lo...

  2. Heavy-ion irradiation induced alteration in histopathology and cancer stem cell markers

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate whether carbon ion irradiation had beneficial effects by targeting cancer stem cells, human colon cancer cells were treated in vitro and in vivo by carbon ion or X-rays irradiation. The relative biological effectiveness (RBE) value of carbon ion relative to X-rays was calculated to be 1.6 in vitro (D10 survival fraction) and 3.82 in vivo (tumor regrowth delay). FACS data provide evidence that cancer stem-like CD133+, CD44+ and EpCAM+ cells were highly enriched after low linear energy transfer (LET) X-rays compared to high LET carbon ion irradiation in a dose-dependent manner. At an isodose of 30 Gy, carbon ion irradiation predominantly induced xenograft tumor cell cavitation and fibrosis, whereas X-rays irradiation only partially destroyed the tumor cell mass. The expression of cancer stem-like cell markers, CD133, EpCAM, and CD44 were significantly suppressed following carbon ion irradiation. In contrast, X-rays actually increased the expression of these proteins. Heavy ion irradiation has a great potential to effectively target radioresistant cancer stem cells. This is considered to be one of the major contributing factors for the high radiocurability of heavy ion cancer treatment. (author)

  3. Enhancement of SPHK1 in vitro by carbon ion irradiation in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Purpose The purpose of this study was to assess the gene expression changes in oral squamous cell carcinoma (OSCC) cells after carbon ion irradiation. Methods and Materials Three OSCC cell lines (HSC2, Ca9-22, and HSC3) were irradiated with accelerated carbon ion beams or X-rays using three different doses. The cellular sensitivities were determined by clonogenic survival assay. To identify genes the expression of which is influenced by carbon ion irradiation in a dose-dependent manner, we performed Affymetrix GeneChip analysis with HG-U133 plus 2.0 arrays containing 54,675 probe sets. The identified genes were analyzed using the Ingenuity Pathway Analysis Tool to investigate the functional network and gene ontology. Changes in mRNA expression in the genes were assessed by real-time reverse transcriptase-polymerase chain reaction. Results We identified 98 genes with expression levels that were altered significantly at least twofold in each of the three carbon-irradiated OSCC cell lines at all dose points compared with nonirradiated control cells. Among these, SPHK1, the expression of which was significantly upregulated by carbon ion irradiation, was modulated little by X-rays. The function of SPHK1 related to cellular growth and proliferation had the highest p value (p = 9.25e-7 to 2.19e-2). Real-time reverse transcriptase-polymerase chain reaction analysis showed significantly elevated SPHK1 expression levels after carbon ion irradiation (p < 0.05), consistent with microarray data. Clonogenic survival assay indicated that carbon ion irradiation could induce cell death in Ca9-22 cells more effectively than X-rays. Conclusions Our findings suggest that SPHK1 helps to elucidate the molecular mechanisms and processes underlying the biologic response to carbon ion beams in OSCC

  4. The fragment ion distribution of C60 in close collision with fast carbon ions

    International Nuclear Information System (INIS)

    We have measured the mass distribution of fragment ions of C60 produced by collisions with 15.6 MeV carbon ions in different charge states. Close collisions were selectively measured using the coincidence method with the change of the projectile charge state. For the electron capture and loss by C5+.6+ projectile ions, which are the K-electron processes, the multifragmentation was observed evidently. In L-electron loss channels of the C2+ projectile, the peaks of the multiply ionized C60 ions and the multiply ionized fullerene-like fragment ions are more intense or as intense as the small fragment ions. (author)

  5. Molecular dynamics study of radiation damage and microstructure evolution of zigzag single-walled carbon nanotubes under carbon ion incidence

    Science.gov (United States)

    Li, Huan; Tang, Xiaobin; Chen, Feida; Huang, Hai; Liu, Jian; Chen, Da

    2016-07-01

    The radiation damage and microstructure evolution of different zigzag single-walled carbon nanotubes (SWCNTs) were investigated under incident carbon ion by molecular dynamics (MD) simulations. The radiation damage of SWCNTs under incident carbon ion with energy ranging from 25 eV to 1 keV at 300 K showed many differences at different incident sites, and the defect production increased to the maximum value with the increase in incident ion energy, and slightly decreased but stayed fairly stable within the majority of the energy range. The maximum damage of SWCNTs appeared when the incident ion energy reached 200 eV and the level of damage was directly proportional to incident ion fluence. The radiation damage was also studied at 100 K and 700 K and the defect production decreased distinctly with rising temperature because radiation-induced defects would anneal and recombine by saturating dangling bonds and reconstructing carbon network at the higher temperature. Furthermore, the stability of a large-diameter tube surpassed that of a thin one under the same radiation environments.

  6. Ion-implanted Mechanism of the Deposition Process for Diamond-Like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-Min; WU Wei-Dong; WANG Yu-Ying; WANG Hai-Ping; GE Fang-Fang; TANG Yong-Jian; JU Xin

    2011-01-01

    Due to the local densification, high-energy C and doped ions can greatly affect the bonding configurations of diamond-like carbon films. We investigate the corresponding affection of different incident ions with energy from WeV to 600eV by Monte Carlo methods. The ion-implanted mechanism called the subplantation (for C, N, O, W, Y, etc.) is confirmed. Obvious thermal effect could be induced by the subplantation of the incident ions. Further, the subplantation of C ions is proved by in situ reflection high energy electron diffraction (RHEED). The observation from an atomic force microscope (AFM) indicates that the initial implantation of C ions might result in the final primitive-cell-like morphology of the smooth film (in an area of 1.2 mm × 0.9 mm, rms roughness smaller than 20 nm by Wyko).

  7. Imaging of carbon nanomembranes with helium ion microscopy

    Directory of Open Access Journals (Sweden)

    André Beyer

    2015-08-01

    Full Text Available Carbon nanomembranes (CNMs prepared from aromatic self-assembled monolayers constitute a recently developed class of 2D materials. They are made by a combination of self-assembly, radiation-induced cross-linking and the detachment of the cross-linked SAM from its substrate. CNMs can be deposited on arbitrary substrates, including holey and perforated ones, as well as on metallic (transmission electron microscopy grids. Therewith, freestanding membranes with a thickness of 1 nm and macroscopic lateral dimensions can be prepared. Although free-standing CNMs cannot be imaged by light microscopy, charged particle techniques can visualize them. However, CNMs are electrically insulating, which makes them sensitive to charging. We demonstrate that the helium ion microscope (HIM is a good candidate for imaging freestanding CNMs due to its efficient charge compensation tool. Scanning with a beam of helium ions while recording the emitted secondary electrons generates the HIM images. The advantages of HIM are high resolution, high surface sensitivity and large depth of field. The effects of sample charging, imaging of multilayer CNMs as well as imaging artefacts are discussed.

  8. Study on organosilicon plasma polymers implanted by carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Radeva, E; Yourukova, L; Kolentsov, K; Balabanov, S; Zhechev, D; Steflekova, V [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Amov, B [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria)], E-mail: eradeva@issp.bas.bg

    2008-05-01

    In the present work plasma polymer films obtained from hexamethyldisiloxane have been implanted by carbon ions at three different doses. The photoluminescent properties of the implanted polymers were investigated. The optical transmission of these polymer layers was investigated in the visible spectral region. Their electrical parameters were also measured. It was found that the resulting changes do not worsen the protective properties of the implanted polymer layer. The variations in the properties studied might be ascribed to the nanostructured carbon clusters formed on the polymer surface. The results obtained could form the basis for further optimization of the polymer structure by carbon ion implantation in view of applications in electroluminescent display structures.

  9. Rechargeable Batteries with High Energy Storage Activated by In-situ Induced Fluorination of Carbon Nanotube Cathode

    OpenAIRE

    Xinwei Cui; Jian Chen; Tianfei Wang; Weixing Chen

    2014-01-01

    High performance rechargeable batteries are urgently demanded for future energy storage systems. Here, we adopted a lithium-carbon battery configuration. Instead of using carbon materials as the surface provider for lithium-ion adsorption and desorption, we realized induced fluorination of carbon nanotube array (CNTA) paper cathodes, with the source of fluoride ions from electrolytes, by an in-situ electrochemical induction process. The induced fluorination of CNTA papers activated the revers...

  10. Ion-induced surface modification of alloys

    International Nuclear Information System (INIS)

    In addition to the accumulation of the implanted species, a considerable number of processes can affect the composition of an alloy in the surface region during ion bombardment. Collisions of energetic ions with atoms of the alloy induce local rearrangement of atoms by displacements, replacement sequences and by spontaneous migration and recombination of defects within cascades. Point defects form clusters, voids, dislocation loops and networks. Preferential sputtering of elements changes the composition of the surface. At temperatures sufficient for thermal migration of point defects, radiation-enhanced diffusion promotes alloy component redistribution within and beyond the damage layer. Fluxes of interstitials and vacancies toward the surface and into the interior of the target induce fluxes of alloying elements leading to depth-dependent compositional changes. Moreover, Gibbsian surface segregation may affect the preferential loss of alloy components by sputtering when the kinetics of equilibration of the surface composition becomes competitive with the sputtering rate. Temperature, time, current density and ion energy can be used to influence the individual processes contributing to compositional changes and, thus, produce a rich variety of composition profiles near surfaces. 42 references

  11. Swift heavy ion irradiation of metal containing tetrahedral amorphous carbon films

    Science.gov (United States)

    Karaseov, P. A.; Protopopova, V. S.; Karabeshkin, K. V.; Shubina, E. N.; Mishin, M. V.; Koskinen, J.; Mohapatra, S.; Tripathi, A.; Avasthi, D. K.; Titov, A. I.

    2016-07-01

    Thin carbon films were grown at room temperature on (0 0 1) n-Si substrate using dual cathode filtered vacuum arc deposition system. Graphite was used as a source of carbon atoms and separate metallic electrode was simultaneously utilized to introduce Ni or Cu atoms. Films were irradiated by 100 MeV Ag7+ ions to fluences in the range 1 × 1010-3 × 1011 cm-2. Rutherford backscattering spectroscopy, Raman scattering, scanning electron microscopy and atomic force microscopy in conductive mode were used to investigate film properties and structure change under irradiation. Some conductive channels having metallic conductivity type were found in the films. Number of such channels is less than number of impinged ions. Presence of Ni and Cu atoms increases conductivity of those conductive channels. Fluence dependence of all properties studied suggests different mechanisms of swift heavy ion irradiation-induced transformation of carbon matrix due to different chemical effect of nickel and copper atoms.

  12. Formation of carbon nanostructures containing single-crystalline cobalt carbides by ion irradiation method

    Science.gov (United States)

    Wang, Zhipeng; Yusop, Zamri; Ghosh, Pradip; Hayashi, Yasuhiko; Tanemura, Masaki

    2011-02-01

    Carbon nanofibers (CNFs) with a diameter of 17 nm, and carbon nanoneedles (CNNs) with sharp tips have been synthesized on graphite substrates by ion irradiation of argon ions with the Co supplies rate of 1 and 3.4 nm/min, respectively. Energy dispersive X-ray spectrometry, combined with selected area electron diffraction patterns has been used to identify the chemical composition and crystallinity of these carbon nanostructures. The CNFs were found to be amorphous in nature, while the structures of the CNNs consisted of cubic CoCx, orthorhombic Co2C and Co3C depending on the cobalt content in the CNNs. The diameter of the carbide crystals was almost as large as the diameter of the CNN. Compared to the ion-induced nickel carbides and iron carbides, the formation of single-crystalline cobalt carbides might be due to the high temperature produced by the irradiation.

  13. Formation of carbon nanostructures containing single-crystalline cobalt carbides by ion irradiation method

    International Nuclear Information System (INIS)

    Carbon nanofibers (CNFs) with a diameter of 17 nm, and carbon nanoneedles (CNNs) with sharp tips have been synthesized on graphite substrates by ion irradiation of argon ions with the Co supplies rate of 1 and 3.4 nm/min, respectively. Energy dispersive X-ray spectrometry, combined with selected area electron diffraction patterns has been used to identify the chemical composition and crystallinity of these carbon nanostructures. The CNFs were found to be amorphous in nature, while the structures of the CNNs consisted of cubic CoCx, orthorhombic Co2C and Co3C depending on the cobalt content in the CNNs. The diameter of the carbide crystals was almost as large as the diameter of the CNN. Compared to the ion-induced nickel carbides and iron carbides, the formation of single-crystalline cobalt carbides might be due to the high temperature produced by the irradiation.

  14. Induced radioactivity of a GSO scintillator by secondary fragments in carbon ion therapy and its effects on in-beam OpenPET imaging

    Science.gov (United States)

    Hirano, Yoshiyuki; Nitta, Munetaka; Nishikido, Fumihiko; Yoshida, Eiji; Inadama, Naoko; Yamaya, Taiga

    2016-07-01

    The accumulation of induced radioactivity within in-beam PET scanner scintillators is of concern for its long-term clinical usage in particle therapy. To estimate the effects on OpenPET which we are developing for in-beam PET based on GSOZ (Zi doped Gd2SiO5), we measured the induced radioactivity of GSO activated by secondary fragments in a water phantom irradiation by a 12C beam with an energy of 290 MeV u‑1. Radioisotopes of Na, Ce, Eu, Gd, Nd, Pm and Tb including positron emitters were observed in the gamma ray spectra of the activated GSO with a high purity Ge detector and their absolute radioactivities were calculated. We used the Monte Carlo simulation platform, Geant4 in which the observed radioactivity was assigned to the scintillators of a precisely reproduced OpenPET and the single and coincidence rates immediately after one treatment and after one-year usage were estimated for the most severe conditions. Comparing the highest coincidence rate originating from the activated scintillators (background) and the expected coincidence rate from an imaging object (signal), we determined the expected signal-to-noise ratio to be more than 7 within 3 min and more than 10 within 1 min from the scan start time. We concluded the effects of scintillator activation and their accumulation on the OpenPET imaging were small and clinical long-term usage of the OpenPET was feasible.

  15. Ion-exchange behavior of alkali metals on treated carbons

    International Nuclear Information System (INIS)

    The ion-exchange behavior of trace quantities of the alkali-metal ions sodium and cesium, on activated carbon impregnated with zirconium phosphate (referred to here as ZrP), was studied. Impregnated carbon had twice as much ion-exchange activity as unimpregnated, oxidized carbon, and 10 times as much as commercial activated carbons. The distribution coefficient of sodium increased with increasing pH; the distribution coefficient of cesium decreased with increasing pH. Sodium and cesium were separated with an electrolytic solution of 0.1 M HCl. Preliminary studies indicated that 0.2 M potassium and cesium can also be separated. Distribution coefficients of the supported ZrP were determined by the elution technique and agreed within 20% of the values for pure ZrP calculated from the literature

  16. Ion-induced effects on metallic nanoparticles

    International Nuclear Information System (INIS)

    This work deals with the ion-irradiation of metallic nanoparticles in combination with various substrates. Particle diameters were systematically varied within the range of 2.5-14 nm, inter-particle distances range from 30-120 nm. Irradiations were performed with various inert gas ions with energies of 200 keV, resulting in an average ion range larger than the particle dimensions and therefore the effects of irradiation are mainly due to creation of structural defects within the particles and the underlying substrate as well. The main part of this work deals with ion-induced burrowing of metallic nanoparticles into the underlying substrate. The use of micellar nanoparticles with sharp size distribution combined with AFM and TEM analysis allows a much more detailed look at this effect than other works on that topic so far. With respect to the particle properties also a detailed look on the effect of irradiation on the particle structure would be interesting, which might lead to a deliberate influence on magnetic properties, for example. Within the context of this work, first successful experiments were performed on FePt particles, showing a significant reduction of the ordering temperature leading to the magnetically interesting, ordered L10 phase. (orig.)

  17. Investigation of different-ligand complexes of holmium and erbium with NTA and carbonate ion

    International Nuclear Information System (INIS)

    Found out have been the optimum conditions for the formation of the lantanides (Ln) multiligand complexes with the nitriletriacetic acid (NTA) and the carbonate-ion. It has been established that the components correlation in complex compounds is equal to 1:1:1. Computed have been the values of the oscillator forces of the absorption bands, that conform to the ''supersensitive'' migration of the multiligand complexes, It is shown that the increment in the oscillator forces, the induced entering of one carbonate-ion into the Ln-NTA complex molecule conforms to about 1/4 of the oscillator forces increment during the migration from the aquo ion to the [Ln(CO3)4]5- complex carbonaceous ion

  18. Magnetoresistance and ion bombardment induced magnetic patterning

    International Nuclear Information System (INIS)

    In this thesis the combination of the magnetic patterning of the unidirectional anisotropy and the tunnel magnetoresistance effect is investigated. In my diploma thesis, it has been shown that it is in principle possible to use the magnetic patterning by ion bombardment to magnetically structure the pinned layer in magnetic tunnel junctions (MTJs) with alumina barrier. Furthermore, it has been shown that the side effects which have been observed after this treatment can be at least reduced by an additional heating step. Starting from this point, the applicability of ion bombardment induced magnetic patterning (IBMP) in general and the combination of IBMP and MTJs in particular is investigated and new applications are developed. (orig.)

  19. Induction of apoptosis in murione spleen lymphocytes using carbon ion beam

    International Nuclear Information System (INIS)

    To assess the capacity of heavy ions to induce apoptosis in lymphocytes, mice have been irradiated with accelerated carbon ions (95 MeV/nucleon) at doses ranging from 0.1 to 4 Gy. Their spleens were removed 24 h later and gently dissociated to prepare a single cell suspension. Mononuclear cells were then maintained in culture at 37oC, and the occurrence of apoptosis in these cells was analysed 24 h later. Lymphocytes were also irradiated in vitro, in the presence of Ac-DEVD-CHO, a potent caspase-3 and -7 inhibitor. Results from three experiments performed at the Grand Accelerateur National d'Ions Lourds (GANIL, Caen, France) are reported here. They indicate that carbon ions induce a marked, dose-dependent, reduction of the spleen weight and cellularity. However, in sharp contrast with spleen cells prepared from X-ray irradiated mice, only a slight increase of apoptosis is evidenced in cultured lymphocytes from mice irradiated with heavy ions. The significance of such results is discussed. So far, few data exist concerning the biological effects of heavy ions, in particular their capacity to induce apoptosis in lymphocytes; the present study provides useful clues for further investigations. (author)

  20. Heavy-ion induced electronic desorption of gas from metals

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-19

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

  1. Numerical and experimental studies of the carbon etching in EUV-induced plasma

    CERN Document Server

    Astakhov, D I; Lee, C J; Ivanov, V V; Krivtsun, V M; Yakushev, O; Koshelev, K N; Lopaev, D V; Bijkerk, F

    2015-01-01

    We have used a combination of numerical modeling and experiments to study carbon etching in the presence of a hydrogen plasma. We model the evolution of a low density EUV-induced plasma during and after the EUV pulse to obtain the energy resolved ion fluxes from the plasma to the surface. By relating the computed ion fluxes to the experimentally observed etching rate at various pressures and ion energies, we show that at low pressure and energy, carbon etching is due to chemical sputtering, while at high pressure and energy a reactive ion etching process is likely to dominate.

  2. Multifragmentation in light-ion-induced reactions

    Energy Technology Data Exchange (ETDEWEB)

    Morley, K.B.; Kwiatkowski, K.; Bracken, D.S. [and others

    1995-04-01

    Multifragmentation of {sup nat}Ag and {sup 197}Au nuclei induced by 4.8 GeV {sup 3}He ions has been studied with the ISiS 4{pi} detector array. Rapidity and moving source analyses are consistent with thermal emission from a source in approximate kinetic equilibrium. For the most dissipative collisions, the spectral Coulomb peaks are broadened to very low energies, indicative of emission from an expanded nuclear system. Predictions of an intranuclear cascade/expanding, emitting source model compare well with experimental multiplicity distributions and the evolution of fragment spectral shapes.

  3. Multifragmentation in light-ion-induced reactions

    International Nuclear Information System (INIS)

    Multifragmentation of natAg and 197Au nuclei induced by 4.8 GeV 3He ions has been studied with the ISiS 4π detector array. Rapidity and moving source analyses are consistent with thermal emission from a source in approximate kinetic equilibrium. For the most dissipative collisions, the spectral Coulomb peaks are broadened to very low energies, indicative of emission from an expanded nuclear system. Predictions of an intranuclear cascade/expanding, emitting source model compare well with experimental multiplicity distributions and the evolution of fragment spectral shapes

  4. MOLECULAR ION DETECTION BY A LASER INDUCED CHANGE IN MOBILITY

    OpenAIRE

    Walkup, R.; Dreyfus, R.; Avouris, Ph.

    1983-01-01

    We report the optogalvanic detection of molecular ions (N+2, CO+) via a laser induced change in ion mobility. The technique relies on a difference in collision limited transport of excited vs. ground state ions, and provides a uniquely sensitive probe of ions in the cathode sheath region of glow discharges.

  5. Separation of Carbon Dioxide from Flue Gas Using Ion Pumping

    Energy Technology Data Exchange (ETDEWEB)

    Aines, R; Bourcier, W L; Johnson, M R

    2006-04-21

    We are developing a new way of separating carbon dioxide from flue gas based on ionic pumping of carbonate ions dissolved in water. Instead of relying on large temperature or pressure changes to remove carbon dioxide from solvent used to absorb it from flue gas, the ion pump increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, which can be removed from the downstream side of the ion pump as a nearly pure gas. This novel approach to increasing the concentration of the extracted gas permits new approaches to treating flue gas. The slightly basic water used as the extraction medium is impervious to trace acid gases that destroy existing solvents, and no pre-separation is necessary. The simple, robust nature of the process lends itself to small separation plants. Although the energy cost of the ion pump is significant, we anticipate that it will be compete favorably with the current 35% energy penalty of chemical stripping systems in use at power plants. There is the distinct possibility that this simple method could be significantly more efficient than existing processes.

  6. Time-resolved ion beam induced charge collection (TRIBICC) in micro-electronics

    International Nuclear Information System (INIS)

    The entire current transient induced by single 12 MeV Carbon ions was measured at a 5GHz analog bandwidth. A focused ion micro-beam was used to acquire multiple single ion transients at multiple locations of a single CMOS transistor. The current transients reveal clear and discernible contributions of drift and diffusive charge collection. Transients measured for drain and off-drain ion strikes compare well to 3D DAVINCI calculations. Estimates are presented for the drift assisted funneling charge collection depth

  7. Time-resolved ion beam induced charge collection (TRIBICC) in micro-electronics

    Energy Technology Data Exchange (ETDEWEB)

    Schoene, H. [Air Force Research Lab., Albuquerque, NM (United States); Walsh, D.S.; Sexton, F.W.; Doyle, B.L.; Aurand, J.F.; Dodd, P.E.; Flores, R.S.; Wing, N. [Sandia National Labs., Albuquerque, NM (United States)

    1998-08-01

    The entire current transient induced by single 12 MeV Carbon ions was measured at a 5GHz analog bandwidth. A focused ion micro-beam was used to acquire multiple single ion transients at multiple locations of a single CMOS transistor. The current transients reveal clear and discernible contributions of drift and diffusive charge collection. Transients measured for drain and off-drain ion strikes compare well to 3D DAVINCI calculations. Estimates are presented for the drift assisted funneling charge collection depth.

  8. Hyperkalaemia induced by carbonic anhydrase inhibitor.

    OpenAIRE

    Wakabayashi, Y.

    1991-01-01

    An 81-year-old man developed hyperkalaemic and hyperchloraemic metabolic acidosis following treatment with a carbonic anhydrase inhibitor for his glaucoma. He had mild renal failure and selective aldosterone deficiency was confirmed. In this case the treatment did not lead to hypokalaemia because of the limited potassium secretory capacity in the renal tubules from selective aldosterone deficiency; rather, it may have led to hyperkalaemia because metabolic acidosis induced by the carbonic anh...

  9. Modeling of Sheath Ion-Molecule Reactions in Plasma Enhanced Chemical Vapor Deposition of Carbon Nanotubes

    Science.gov (United States)

    Hash, David B.; Govindan, T. R.; Meyyappan, M.

    2004-01-01

    In many plasma simulations, ion-molecule reactions are modeled using ion energy independent reaction rate coefficients that are taken from low temperature selected-ion flow tube experiments. Only exothermic or nearly thermoneutral reactions are considered. This is appropriate for plasma applications such as high-density plasma sources in which sheaths are collisionless and ion temperatures 111 the bulk p!asma do not deviate significantly from the gas temperature. However, for applications at high pressure and large sheath voltages, this assumption does not hold as the sheaths are collisional and ions gain significant energy in the sheaths from Joule heating. Ion temperatures and thus reaction rates vary significantly across the discharge, and endothermic reactions become important in the sheaths. One such application is plasma enhanced chemical vapor deposition of carbon nanotubes in which dc discharges are struck at pressures between 1-20 Torr with applied voltages in the range of 500-700 V. The present work investigates The importance of the inclusion of ion energy dependent ion-molecule reaction rates and the role of collision induced dissociation in generating radicals from the feedstock used in carbon nanotube growth.

  10. Response of SOI image sensor to therapeutic carbon ion beam

    CERN Document Server

    Matsumura, Akihiko

    2015-01-01

    Carbon ion radiotherapy is known as a less invasive cancer treatment. The radiation quality is an important parameter to evaluate the biological effect and the clinical dose from the measured physical dose. The performance of SOPHIAS detector, which is the SOI image sensor having a wide dynamic range and large active area, was tested by using therapeutic carbon ion beam at Gunma University Heavy Ion Medical Center (GHMC). It was shown that the primary carbon and secondary particles can be distinguishable by SOPHIAS detector. On the other hand, a LET dependence was observed especially at the high LET region. This phenomenon will be studied by using the device simulator together with Monte Carlo simulation.

  11. Fabrication of carbon nanostructures (nanodots, nanowires) by energetic ion irradiation

    International Nuclear Information System (INIS)

    Carbon nanostructures were synthesized by energetic ion irradiation of Si-based gel films. These polymer-like films with different side groups and C concentrations were prepared by sol-gel chemistry and irradiated with Si or Au ions of different energies in the range 3 MeV-2 GeV. The shape and size of the formed carbon nanostructures was studied by energy filtered transmission electron microscopy. They exhibited a visible photoluminescence emission, due to their semiconducting nature and the confinement of excitons. The changes in the optical properties were correlated with the structural transformation of films, investigated by means of Fourier transformed infrared (FTIR) and Raman spectroscopies. The role of carbon concentration, structure and energy transferred by ions on the luminescence properties are discussed

  12. Carbon stripper foils for high current heavy ion operation

    International Nuclear Information System (INIS)

    For the proposed new heavy ion linac'at'GSI the installation of a carbon foil stripper section is under discussion. High duty factor as well as high current (but low duty factor) heavy ion beams were used for machine experiments. Long term tests were performed to check the carbon foil durability. Relevant beam parameters have been measured in three measurement campaigns. After beam testing stripper foils were analyzed with different offline methods. Additionally promising results of high current beam irradiation of rotating target wheels will be presented. In the transfer line to the SIS 18 the heavy ion beam is stripped to higher charge states in a thick carbon foil. The stripper foil is loaded with 3 % of the beam power. To avoid evaporation in a single beam pulse, the beam is rapidly swept over its width. Experiences collected during the last decade of foil stripper operation at GSI will be presented. (author)

  13. Persistent ion beam induced conductivity in zinc oxide nanowires

    OpenAIRE

    Johannes, Andreas; Niepelt, Raphael; Gnauck, Martin; Ronning, Carsten

    2015-01-01

    We report persistently increased conduction in ZnO nanowires irradiated by ion beam with various ion energies and species. This effect is shown to be related to the already known persistent photo conduction in ZnO and dubbed persistent ion beam induced conduction. Both effects show similar excitation efficiency, decay rates, and chemical sensitivity. Persistent ion beam induced conduction will potentially allow countable (i.e., single dopant) implantation in ZnO nanostructures and other mater...

  14. Activated carbon is an electron-conducting amphoteric ion adsorbent

    OpenAIRE

    Biesheuvel, P. M.

    2015-01-01

    Electrodes composed of activated carbon (AC) particles can desalinate water by ion electrosorption. To describe ion electrosorption mathematically, accurate models are required for the structure of the electrical double layers (EDLs) that form within electrically charged AC micropores. To account for salt adsorption also in uncharged ACs, an "attraction term" was introduced in modified Donnan models for the EDL structure in ACs. Here it will be shown how instead of using an attraction term, c...

  15. Heavy-ion induced current in MOS structure

    International Nuclear Information System (INIS)

    The heavy-ion induced current in MOS structure has been investigated. We measured transient currents in MOS capacitors induced by 18 MeV Oxygen and 150 MeV Argon ions. The irradiation tests were carried out using the Single Ion Hit system and the current was measured using a Transient Ion Beam Induced Current measurement system. The current was calculated using device simulator and compared with measured data. It was confirmed that the transient current in MOS structure is dominated by a displacement current; that is caused by changing of surface potential under gate electrode due to the charges moved from ion-track region. (author)

  16. On influence of irradiation by carbon ions on tantalum structure

    International Nuclear Information System (INIS)

    Data of experimental studies on tantalum surface structure change and it microhardness in the result of carbon ion implantation are presented. The tantalum samples with purity 99.96 % having cylindrical shape (height 55 mm and diameter 4.5-5 mm) after polish were irradiated by carbon ions with energy 60 keV in the range 5·1016-5·1018 cm-2 at the DIANA facility. The microhardness measurement has been conducted on the PMT-3 device on the irradiated surface and along samples cross section. The microstructure has been examined on the NEOFOT-21 optical microscope, and phase-structural transformations were studied on the 3.0 DRON X-ray diffractometer with application of CuKα radiation. It is determined, that under carbon ion implantation into tantalum surface layers the texture tantalum carbide phases and tantalum monocarbide arise. Post-radiation thermal annealing leads to tantalum monocarbide decay and tantalum carbide particle sizes increase. It is determined, that phases got under C+ implantation have introduction phase structure with dense atom packing. Ion doping leads to tantalum surface hardening. Hardening rate depends on the irradiation fluence. Maximal hardening has been observed on the surface, the maximal microhardness increase extension along whole samples thickness. Due to carbon ions implantation the microhardness is increasing in 3 times near surface, and up to 1.5-3 times over samples thickness

  17. Conducting carbon nanopatterns (nanowire) by energetic ion irradiation

    International Nuclear Information System (INIS)

    This work reports the formation of conducting carbon nanopatterns (nano-wires) in a semi-inorganic polymer by irradiation with energetic ions. The conducting nano-patterns/wires are evidenced by conducting atomic force microscopy. The typical diameter of the conducting wires is observed to be about ∼50-200 nm. The density (spacing), growth direction and length of these carbon nanowires can be changed simply by ion fluence, angle of irradiation and the film thickness, respectively. The formation of conducting nanopatterns in an insulating matrix (polymers/gels) is correlated with the structural transformation of films, investigated by means of Raman spectroscopy

  18. Stoichiometric carbon nitride synthesized by ion beam sputtering and post nitrogen ion implantation

    International Nuclear Information System (INIS)

    Full text: Carbon nitride films have been deposited on Si (100) by ion beam sputtering a vitreous graphite target with nitrogen and argon ions with and without concurrent N2 ion bombardment at room temperature. The sputtering beam energy was 1000 eV and the assisted beam energy was 300 eV with ion / atom arrival ratio ranging from 0.5 to 5. The carbon nitride films were deposited both as single layer directly on silicon substrate and as multilayer between two layers of stoichiometric amorphous silicon nitride and polycrystalline titanium nitride. The deposited films were implanted ex-situ with 30 keV nitrogen ions with various doses ranging from 1E17 to 4E17 ions.cm-2 and 2 GeV xenon ion with a dose of 1E12 ions.cm-2 . The nitrogen concentration of the films was measured with Rutherford Backscattering (RBS), Secondary Neutral Mass Spectrometry (SNMS) and Parallel Electron Energy Loss Spectroscopy (PEELS). The nitrogen concentration for as deposited sample was 34 at% and stoichiometric carbon nitride C3N4 was achieved by post nitrogen implantation of the multi-layered films. Post bombardment of single layer carbon nitride films lead to reduction in the total nitrogen concentration. Carbon K edge structure obtained from PEELS analysis suggested that the amorphous C3N4 matrix was predominantly sp2 bonded. This was confirmed by Fourier Transforrn Infra-Red Spectroscopy (FTIR) analysis of the single CN layer which showed the nitrogen was mostly bonded with carbon in nitrile (C≡N) and imine (C=N) groups. The microstructure of the film was determined by Transmission Electron Microscopy (TEM) which indicated that the films were amorphous

  19. Atomic-layer-deposition alumina induced carbon on porous NixCo1 − xO nanonets for enhanced pseudocapacitive and Li-ion storage performance

    International Nuclear Information System (INIS)

    A unique composite nanonet of metal oxide@carbon interconnected sheets is obtained by atomic layer deposition (ALD)-assisted fabrication. In this nanonet structure, mesoporous metal oxide nanosheets are covered by a layer of amorphous carbon nanoflakes. Specifically, quasi-vertical aligned and mesoporous NixCo1 − xO nanosheets are first fabricated directly on nickel foam substrates by a hydrothermal method. Then, an ALD-enabled carbon coating method is applied for the growth of carbon nanoflakes on the surface of the nanosheets. The thus formed 3D hierarchical structure of NixCo1 − xO@carbon composite flakes have a higher surface area, better electrical conductivity and structure stability than the bare NixCo1 − xO. The application of such composite nanomaterials is demonstrated as electrodes for a supercapacitor and a lithium-ion battery. In both tests, the composite electrode shows enhancement in capacity and cycling stability. This effective composite nanostructure design of metal oxides@carbon flakes could provide a promising method to construct high-performance materials for energy and environment applications. (paper)

  20. Photoluminescence and reflectivity of polymethylmethacrylate implanted by low-energy carbon ions at high fluences

    International Nuclear Information System (INIS)

    Highlights: ► Photoluminescence was studied in carbon implanted polymethylmethacrylate (PMMA). ► A significant photoluminescence enhancement occurred at ion fluence of 5 × 1016 cm−2. ► Photoluminescence and Raman responses revealed carbon nanoclustered structures. ► Reflectivity of carbon implanted PMMA depended on both ion fluence and wavelength. ► A noticeable reflectivity modification appeared at ion fluence of 1 × 1016 cm−2. - Abstract: Polymethylmethacrylate (PMMA) specimens were implanted with 30 keV carbon ions in a fluence range of 1 × 1016 to 2 × 1017 cm−2, and photoluminescence (PL) and reflectivity of the implanted samples were examined. A luminescent band with one peak was found in PL spectra excited by 480 nm line, but its intensity did not vary in parallel with ion fluence. The strongest PL occurred at the fluence of 5 × 1016 cm−2. Results from visible-light-excited micro-Raman spectra indicated that the formation of hydrogenated amorphous carbon structures in subsurface layer and their evolutions with ion fluence could be responsible for the observed PL responses. Measurements of the small-angle reflectance spectra from both the implanted and rear surfaces of samples in the ultraviolet–visible (UV–vis) range demonstrated a kind of both fluence-dependent and wavelength-related reflectivity variations, which were attributed to the structural changes induced by ion implantation. A noticeable reflectivity modification, which may be practically used, could be found at the fluence of 1 × 1016 cm−2.

  1. Photoluminescence and reflectivity of polymethylmethacrylate implanted by low-energy carbon ions at high fluences

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jun; Zhu Fei; Zhang Bei; Liu Huixian; Jia Guangyi [School of Science, Tianjin University, Tianjin 300072 (China); Liu Changlong, E-mail: liuchanglong@tju.edu.cn [School of Science, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Institute of Advanced Materials Physics Faculty of Science, Tianjin 300072 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Photoluminescence was studied in carbon implanted polymethylmethacrylate (PMMA). Black-Right-Pointing-Pointer A significant photoluminescence enhancement occurred at ion fluence of 5 Multiplication-Sign 10{sup 16} cm{sup -2}. Black-Right-Pointing-Pointer Photoluminescence and Raman responses revealed carbon nanoclustered structures. Black-Right-Pointing-Pointer Reflectivity of carbon implanted PMMA depended on both ion fluence and wavelength. Black-Right-Pointing-Pointer A noticeable reflectivity modification appeared at ion fluence of 1 Multiplication-Sign 10{sup 16} cm{sup -2}. - Abstract: Polymethylmethacrylate (PMMA) specimens were implanted with 30 keV carbon ions in a fluence range of 1 Multiplication-Sign 10{sup 16} to 2 Multiplication-Sign 10{sup 17} cm{sup -2}, and photoluminescence (PL) and reflectivity of the implanted samples were examined. A luminescent band with one peak was found in PL spectra excited by 480 nm line, but its intensity did not vary in parallel with ion fluence. The strongest PL occurred at the fluence of 5 Multiplication-Sign 10{sup 16} cm{sup -2}. Results from visible-light-excited micro-Raman spectra indicated that the formation of hydrogenated amorphous carbon structures in subsurface layer and their evolutions with ion fluence could be responsible for the observed PL responses. Measurements of the small-angle reflectance spectra from both the implanted and rear surfaces of samples in the ultraviolet-visible (UV-vis) range demonstrated a kind of both fluence-dependent and wavelength-related reflectivity variations, which were attributed to the structural changes induced by ion implantation. A noticeable reflectivity modification, which may be practically used, could be found at the fluence of 1 Multiplication-Sign 10{sup 16} cm{sup -2}.

  2. Laser-induced nuclear motions in the Coulomb explosion of C2H2+ ions

    International Nuclear Information System (INIS)

    The laser-induced multifragmentation of C2H2 into protons and multicharged carbon ions is shown to be a direct instantaneous explosion of the molecule. The evolution of the overall nuclear structure is studied through ion-ion correlation peak shapes. The ratios of the maxima of the kinetic-energy release distributions to the Coulomb repulsion energies calculated at the equilibrium internuclear distances are measured to be 45% for the protons and 53% for the CZ+ ions for all the detected H++CZ'++CZ+ +H+ fragmentation channels. The time scale for electronic polarization and stripping compared with the intramolecular electronic and nuclear time evolutions does not allow using a frozen molecular ion structure for the description of the explosion, thus explaining in part the observed fragmentation pattern. During the laser-induced alignment and subsequent stabilization of the molecular frame around the laser polarization direction, the carbon-carbon axis undergoes small damped oscillations that remain larger than the corresponding oscillations of the hydrogen-hydrogen axis. This difference comes from the lower moment of inertia of the hydrogen atoms compared with that of the carbon atoms in the molecule. However, the subsequent deviation from the initial linear structure remains small and is observed when the molecular ion is not completely aligned along the laser electric field

  3. Drought-induced carbon loss in peatlands

    Science.gov (United States)

    Fenner, Nathalie; Freeman, Chris

    2011-12-01

    Peatlands store vast amounts of organic carbon, amounting to approximately 455 Pg. Carbon builds up in these water-saturated environments owing to the presence of phenolic compounds--which inhibit microbial activity and therefore prevent the breakdown of organic matter. Anoxic conditions limit the activity of phenol oxidase, the enzyme responsible for the breakdown of phenolic compounds. Droughts introduce oxygen into these systems, and the frequency of these events is rising. Here, we combine in vitro manipulations, mesocosm experiments and field observations to examine the impact of drought on peatland carbon loss. We show that drought stimulates bacterial growth and phenol oxidase activity, resulting in a reduction in the concentration of phenolic compounds in peat. This further stimulates microbial growth, causing the breakdown of organic matter and the release of carbon dioxide in a biogeochemical cascade. We further show that re-wetting the peat accelerates carbon losses to the atmosphere and receiving waters, owing to drought-induced increases in nutrient and labile carbon levels, which raise pH and stimulate anaerobic decomposition. We suggest that severe drought, and subsequent re-wetting, could destabilize peatland carbon stocks; understanding this process could aid understanding of interactions between peatlands and other environmental trends, and lead to the development of strategies for increasing carbon stocks.

  4. Fluorescence emission from CsI(Tl) crystals induced by high-energy heavy ions

    International Nuclear Information System (INIS)

    The fluorescence radiation from a CsI(Tl) scintillator induced by high-energy carbon ions was investigated. The structures of the emission spectra in the ultraviolet and visible bands as well as their intensity dependence on the projectile energy are reported

  5. Ion beam induced defects in solids studied by optical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Comins, J.D. [Materials Physics Research Institute, School of Physics, University of the Witwatersrand, Johannesburg (South Africa); Raman and Luminescence Laboratory, University of the Witwatersrand, Johannesburg (South Africa); DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Johannesburg (South Africa)], E-mail: darrell.comins@wits.ac.za; Amolo, G.O. [Materials Physics Research Institute, School of Physics, University of the Witwatersrand, Johannesburg (South Africa); Derry, T.E.; Connell, S.H. [DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Johannesburg (South Africa); Erasmus, R.M. [Raman and Luminescence Laboratory, University of the Witwatersrand, Johannesburg (South Africa); DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Johannesburg (South Africa); Witcomb, M.J. [DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Johannesburg (South Africa); Electron Microscope Unit, University of the Witwatersrand, Johannesburg (South Africa)

    2009-08-15

    Optical methods can provide important insights into the mechanisms and consequences of ion beam interactions with solids. This is illustrated by four distinctly different systems. X- and Y-cut LiNbO{sub 3} crystals implanted with 8 MeV Au{sup 3+} ions with a fluence of 1 x 10{sup 17} ions/cm{sup 2} result in gold nanoparticle formation during high temperature annealing. Optical extinction curves simulated by the Mie theory provide the average nanoparticle sizes. TEM studies are in reasonable agreement and confirm a near-spherical nanoparticle shape but with surface facets. Large temperature differences in the nanoparticle creation in the X- and Y-cut crystals are explained by recrystallisation of the initially amorphised regions so as to recreate the prior crystal structure and to result in anisotropic diffusion of the implanted gold. Defect formation in alkali halides using ion beam irradiation has provided new information. Radiation-hard CsI crystals bombarded with 1 MeV protons at 300 K successfully produce F-type centres and V-centres having the I{sub 3}{sup -} structure as identified by optical absorption and Raman studies. The results are discussed in relation to the formation of interstitial iodine aggregates of various types in alkali iodides. Depth profiling of I{sub 3}{sup -} and I{sub 5}{sup -} aggregates created in RbI bombarded with 13.6 MeV/A argon ions at 300 K is discussed. The recrystallisation of an amorphous silicon layer created in crystalline silicon bombarded with 100 keV carbon ions with a fluence of 5 x 10{sup 17} ions/cm{sup 2} during subsequent high temperature annealing is studied by Raman and Brillouin light scattering. Irradiation of tin-doped indium oxide (ITO) films with 1 MeV protons with fluences from 1 x 10{sup 15} to 250 x 10{sup 15} ions/cm{sup -2} induces visible darkening over a broad spectral region that shows three stages of development. This is attributed to the formation of defect clusters by a model of defect growth and

  6. Irradiation effect of carbon negative-ion implantation on polytetrafluoroethylene for controlling cell-adhesion property

    Science.gov (United States)

    Sommani, Piyanuch; Tsuji, Hiroshi; Kojima, Hiroyuki; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo; Takaoka, Gikan H.

    2010-10-01

    We have investigated the irradiation effect of negative-ion implantation on the changes of physical surface property of polytetrafluoroethylene (PTFE) for controlling the adhesion property of stem cells. Carbon negative ions were implanted into PTFE sheets at fluences of 1 × 10 14-1 × 10 16 ions/cm 2 and energies of 5-20 keV. Wettability and atomic bonding state including the ion-induced functional groups on the modified surfaces were investigated by water contact angle measurement and XPS analysis, respectively. An initial value of water contact angles on PTFE decreased from 104° to 88° with an increase in ion influence to 1 × 10 16 ions/cm 2, corresponding to the peak shifting of XPS C1s spectra from 292.5 eV to 285 eV with long tail on the left peak-side. The change of peak position was due to decrease of C-F 2 bonds and increase of C-C bonds with the formation of hydrophilic oxygen functional groups of OH and C dbnd O bonds after the ion implantation. After culturing rat mesenchymal stem cells (MSC) for 4 days, the cell-adhesion properties on the C --patterned PTFE were observed by fluorescent microscopy with staining the cell nuclei and their actin filament (F-actin). The clear adhesion patterning of MSCs on the PTFE was obtained at energies of 5-10 keV and a fluence of 1 × 10 15 ions/cm 2. While the sparse patterns and the uncontrollable patterns were found at a low fluence of 3 × 10 14 ions/cm 2 and a high fluence of 3 × 10 15 ions/cm 2, respectively. As a result, we could improve the surface wettability of PTFE to control the cell-adhesion property by carbon negative-ion implantation.

  7. Gunma University Heavy Ion Medical Center. Evolution of carbon therapy

    International Nuclear Information System (INIS)

    Cancer treatments with high energy carbon beams have been initiated at Gunma University Heavy Ion Medical Center, GHMC, in March of this year. Aiming the wide spread of the carbon therapy, the grand design of the facility and a variety of R and D studies were conducted by HIMAC group of National Institute of Radiological Sciences, NIRS, in collaboration with Gunma University. The design concepts of the facility include the high reliability, high efficiency, and low construction and operation cost. The success of the facility will open up new era of the carbon therapy. (author)

  8. Thermal ion effects on kinetic beta-induced Alfven eigenmodes excited by energetic ions

    Energy Technology Data Exchange (ETDEWEB)

    Qi Longyu; Sheng, Z. M. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Dong, J. Q. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Bierwage, A. [Aomori Research and Development Center, Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Lu Gaimin [Southwestern Institute of Physics, Chengdu 610041 (China)

    2013-03-15

    Kinetic beta-induced Alfven eigenmodes (KBAEs) driven by energetic ions are numerically investigated using revised AWECS code. The thermal ion density and temperature gradients are taken into account. It is found that the growth rate of the KBAEs increases with the thermal ion pressure gradient, and the contributions from the density gradient and temperature gradient of the thermal ions to the enhancement of the instability are comparable. The damping effect of thermal ion dynamics on the modes is also observed.

  9. Local brain heavy ion irradiation induced Immunosuppression

    Science.gov (United States)

    Lei, Runhong; Deng, Yulin; Huiyang Zhu, Bitlife.; Zhao, Tuo; Wang, Hailong; Yu, Yingqi; Ma, Hong; Wang, Xiao; Zhuang, Fengyuan; Qing, Hong

    Purpose: To investigate the long term effect of acute local brain heavy ion irradiation on the peripheral immune system in rat model. Methodology: Only the brain of adult male Wistar rats were radiated by heavy ions at the dose of 15 Gy. One, two and three months after irradiation, thymus and spleen were analyzed by four ways. Tunel assay was performed to evaluate the percentage of apoptotic cells in thymus and spleen, level of Inflammatory cytokines (IL-2, IL-6, SSAO, and TNF-α) was detected by ELISA assay, the differentiation of thymus T lymphocyte subsets were measured by flow cytometry and the relative expression levels of genes related to thymus immune cell development were measured by using quantitative real-time PCR. Results: Thymus and spleen showed significant atrophy from one month to three months after irradiation. A high level of apoptosis in thymus and spleen were obtained and the latter was more vulnerable, also, high level of inflammatory cytokines were found. Genes (c-kit, Rag1, Rag2 and Sca1) related to thymus lymphocytes’ development were down-regulated. Conclusion: Local area radiation in the rat brain would cause the immunosuppression, especially, the losing of cell-mediated immune functions. In this model, radiation caused inflammation and then induced apoptosis of cells in the immune organs, which contributed to immunosuppression.

  10. Heavy ions irradiation-induced mutagenesis on edible seaweeds

    International Nuclear Information System (INIS)

    The effects of heavy ions irradiation on both diploid and haploid phases of edible seaweeds were analyzed. Exposure of diploid conchocelis of a layer Asakusanori Porphyra tenera mutant to 2.5 Gy of carbon ion beam elicited an intense inhibition of its growth, whereas an administration dose-dependent growth inhibition was observed by 3 other particles such as helium, argon and neon ions between 2.5 and 100 Gy. Irradiation of P. tenera haploid gametophytic blades with 2.5∼100 Gy of 4 different heavy ion particles showed no significant difference in their production of carpospore and further development to conchocelis. Results indicate that the sensitivity of layer to heavy ions irradiation varies in diploid and haploid phases, and layer diploid suffers different effects from carbon ion and other ions tested. (author)

  11. Comparison of the effects of photon versus carbon ion irradiation when combined with chemotherapy in vitro

    International Nuclear Information System (INIS)

    Characterization of combination effects of chemotherapy drugs with carbon ions in comparison to photons in vitro. The human colon adenocarcinoma cell line WiDr was tested for combinations with camptothecin, cisplatin, gemcitabine and paclitaxel. In addition three other human tumour cell lines (A549: lung, LN-229: glioblastoma, PANC-1: pancreas) were tested for the combination with camptothecin. Cells were irradiated with photon doses of 2, 4, 6 and 8 Gy or carbon ion doses of 0.5, 1, 2 and 3 Gy. Cell survival was assessed using the clonogenic growth assay. Treatment dependent changes in cell cycle distribution (up to 12 hours post-treatment) were measured by FACS analysis after propidium-iodide staining. Apoptosis was monitored for up to 36 hours post-treatment by Nicoletti-assay (with qualitative verification using DAPI staining). All cell lines exhibited the well-known increase of killing efficacy per unit dose of carbon ion exposure, with relative biological efficiencies at 10% survival (RBE10) ranging from 2.3 to 3.7 for the different cell lines. In combination with chemotherapy additive toxicity was the prevailing effect. Only in combination with gemcitabine or cisplatin (WiDr) or camptothecin (all cell lines) the photon sensitivity was slightly enhanced, whereas purely independent toxicities were found with the carbon ion irradiation, in all cases. Radiation-induced cell cycle changes displayed the generally observed dose-dependent G2-arrest with little effect on S-phase fraction for all cell lines for photons and for carbon ions. Only paclitaxel showed a significant induction of apoptosis in WiDr cell line but independent of the used radiation quality. Combined effects of different chemotherapeutics with photons or with carbon ions do neither display qualitative nor substantial quantitative differences. Small radiosensitizing effects, when observed with photons are decreased with carbon ions. The data support the idea that a radiochemotherapy with common

  12. Processing of diamondlike carbon using plasma immersion ion deposition

    International Nuclear Information System (INIS)

    Plasma immersion ion deposition (PIID) has been used to synthesize hard amorphous hydrogenated carbon or diamondlike carbon (DLC) thin films on Si substrates with rf inductive plasmas of various Ar and C2H2 gas mixtures. The surface hardness and stress of the films were highly dependent on the magnitude of the total rf power and the pulse-bias duty factor. The ratios of the ion flux and the film deposition flux, Ji/Jd, were estimated and correlated with DLC film stress, hardness, and the amount of argon and hydrogen content retained. The DLC properties (hardness and film stress) were maximal when the Ji/Jd value ranged between 0.6 and 0.8. The balance between ion-energy transfer and relaxation in the surface and subsurface carbon atoms may explain the DLC growth in this work. The role of ion-current flux in the PIID process was found to be as important as it is in conventional ion beam assisted deposition processing. copyright 1999 American Vacuum Society

  13. Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

    Science.gov (United States)

    Woodworth James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  14. Modeling Electrochemical Decomposition of Fluoroethylene Carbonate on Silicon Anode Surfaces in Lithium Ion Batteries

    OpenAIRE

    Leung, Kevin; Rempe, Susan B.; Foster, Michael E.; Ma, Yuguang; del la Hoz, Julibeth M. Martinez; Sai, Na; Balbuena, Perla B.

    2014-01-01

    Fluoroethylene carbonate (FEC) shows promise as an electrolyte additive for improving passivating solid-electrolyte interphase (SEI) films on silicon anodes used in lithium ion batteries (LIB). We apply density functional theory (DFT), ab initio molecular dynamics (AIMD), and quantum chemistry techniques to examine excess-electron-induced FEC molecular decomposition mechanisms that lead to FEC-modified SEI. We consider one- and two-electron reactions using cluster models and explicit interfac...

  15. 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....... Methods: Alanine detectors have been irradiated with carbon ions with an energy range of 89-400 MeV/u. The relative effectiveness of alanine has been measured in this regime. Pristine and spread out Bragg peak depth-dose curves have been measured with alanine dosimeters. The track-structure based alanine...... response model developed by J. Hansen and K. Olsen has been implemented in the Monte Carlo code FLUKA, and calculations were compared with experimental results. Results: Calculations of the relative effectiveness deviate less than 5% from the measured values for mono energetic beams. Measured depth...

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

    International Nuclear Information System (INIS)

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

  17. Ion Exclusion by Sub 2-nm Carbon Nanotube Pores

    Energy Technology Data Exchange (ETDEWEB)

    Fornasiero, F; Park, H G; Holt, J K; Stadermann, M; Grigoropoulos, C P; Noy, A; Bakajin, O

    2008-04-09

    Carbon nanotubes offer an outstanding platform for studying molecular transport at nanoscale, and have become promising materials for nanofluidics and membrane technology due to their unique combination of physical, chemical, mechanical, and electronic properties. In particular, both simulations and experiments have proved that fluid flow through carbon nanotubes of nanometer size diameter is exceptionally fast compared to what continuum hydrodynamic theories would predict when applied on this length scale, and also, compared to conventional membranes with pores of similar size, such as zeolites. For a variety of applications such as separation technology, molecular sensing, drug delivery, and biomimetics, selectivity is required together with fast flow. In particular, for water desalination, coupling the enhancement of the water flux with selective ion transport could drastically reduce the cost of brackish and seawater desalting. In this work, we study the ion selectivity of membranes made of aligned double-walled carbon nanotubes with sub-2 nm diameter. Negatively charged groups are introduced at the opening of the carbon nanotubes by oxygen plasma treatment. Reverse osmosis experiments coupled with capillary electrophoresis analysis of permeate and feed show significant anion and cation rejection. Ion exclusion declines by increasing ionic strength (concentration) of the feed and by lowering solution pH; also, the highest rejection is observed for the A{sub m}{sup Z{sub A}} C{sub n}{sup Z{sub C}} salts (A=anion, C=cation, z= valence) with the greatest Z{sub A}/Z{sub C} ratio. Our results strongly support a Donnan-type rejection mechanism, dominated by electrostatic interactions between fixed membrane charges and mobile ions, while steric and hydrodynamic effects appear to be less important. Comparison with commercial nanofiltration membranes for water softening reveals that our carbon nanotube membranes provides far superior water fluxes for similar ion

  18. Physical and chemical response of 70 MeV carbon ion irradiated Kapton-H polymer

    Indian Academy of Sciences (India)

    H S Virk; P S Chandi; A K Srivastava

    2001-10-01

    Physical and chemical responses of 70 MeV carbon ion irradiated Kapton-H polymer were studied by using UV-visible, FTIR and XRD techniques. The ion fluences ranging from 9.3 × 1011–9 × 1013 ions cm–2 were used. Recorded UV-visible spectra clearly showed a decrease in absorption initially with fluence, but for the higher fluences it showed a recovery characteristic. A decrease in band-gap energy of 0.07 eV was observed. The FTIR analysis indicated the high resistance to radiation induced degradation of polymer. The diffraction pattern of Kapton-H indicates that this polymer is semi-crystalline in its nature. In case of irradiated one, there was an average increase of crystallite size by 20%, but diffuse pattern indicates that there was a decrease in crystallinity, which may be attributed to the formation of complex structure induced by the cross-linking of the polymeric chains.

  19. Ion irradiation of electronic-type-separated single wall carbon nanotubes: A model for radiation effects in nanostructured carbon

    International Nuclear Information System (INIS)

    The structural and electrical properties of electronic-type-separated (metallic and semiconducting) single wall carbon nanotube (SWCNT) thin-films have been investigated after irradiation with 150 keV 11B+ and 150 keV 31P+ with fluences ranging from 1012 to 1015 ions/cm2. Raman spectroscopy results indicate that the ratio of the Raman D to G′ band peak intensities (D/G′) is a more sensitive indicator of SWCNT structural modification induced by ion irradiation by one order of magnitude compared to the ratio of the Raman D to G band peak intensities (D/G). The increase in sheet resistance (Rs) of the thin-films follows a similar trend as the D/G′ ratio, suggesting that the radiation induced variation in bulk electrical transport for both electronic-types is equal and related to localized defect generation. The characterization results for the various samples are compared based on the displacement damage dose (DDD) imparted to the sample, which is material and damage source independent. Therefore, it is possible to extend the analysis to include data from irradiation of transferred CVD-graphene films on SiO2/Si substrates using 35 keV C+ ions, and compare the observed changes at equivalent levels of ion irradiation-induced damage to that observed in the SWCNT thin-film samples. Ultimately, a model is developed for the prediction of the radiation response of nanostructured carbon materials based on the DDD for any incident ion with low-energy recoil spectra. The model is also related to the defect concentration, and subsequently the effective defect-to-defect length, and yields a maximum defect concentration (minimum defect-to-defect length) above which the bulk electrical transport properties in SWCNT thin-films and large graphene-based electronic devices rapidly degrade when exposed to harsh environments.

  20. Investigation of physiologically active products obtained from carbon-ion irradiated actinomycetes

    International Nuclear Information System (INIS)

    Charged particles such as carbon-ions are superior to X-rays or gamma-rays in the physical and biological characteristics. The propose research project is aimed to provide new insights on antibiotic development. Carbon-ion exposure reduced cell growth. Product(s) from carbon-ion irradiated microorganera suppressed growth of human leukemia cells. We suggested that carbon-ion irradiated actinomycetes produce antitumor active product(s) for leukemia cells. (author)

  1. Modification of diamond-like carbon by ion irradiation

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) films were irradiated with swift heavy ion beams of varying energy and angles of incidence. The irradiation created electrically conducting tracks in the DLC-films by transforming sp3 into sp2 bonds. The DLC-films were analyzed by conductive atomic force microscopy. The images were used to identify ion impact sites, and I-V-Spectroscopy was applied to determine the conductivity of the tracks. High energy ions (2.2 GeV, Au25+) created tracks with ohmic conductivity in the case of perpendicular bombardment, whereas grazing irradiation results in tracks that show mainly tunneling behavior. Low energy ions (100 MeV, Xe23+) created tracks which exhibit tunneling behaviour after perpendicular incidence irradiation, but irradiation under 1 did not result in conductive tracks.

  2. Heavy ions irradiation-induced mutagenesis on edible seaweeds

    International Nuclear Information System (INIS)

    The effects of heavy ions irradiation on the growth and maturation of edible seaweed mutant, Asakusanori Porphyra tenera, were analyzed. Irradiation of gametophytic blades, haploid phase of P. tenera, to 50 Gy of helium ion beam suppressed their aging, in spite of no effect by that to 10, 25, 100 and 200 Gy of helium ion beam. Irradiation of P. tenera blades to 10∼200 Gy of helium ion beam showed no significant difference in their production of carpospore and further development to conchocelis. Irradiation of P. tenera blades to 50 Gy of carbon ion beam accelerated their development to conchocelis, whereas the blades suffering that to 100 and 200 Gy of carbon ion beam were suspended their maturation. (author)

  3. WIMP detection and slow ion dynamics in carbon nanotube arrays

    CERN Document Server

    Cavoto, G; Cocina, F; Ferretti, J; Polosa, A D

    2016-01-01

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (~ 10 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with ...

  4. WIMP detection and slow ion dynamics in carbon nanotube arrays

    Science.gov (United States)

    Cavoto, G.; Cirillo, E. N. M.; Cocina, F.; Ferretti, J.; Polosa, A. D.

    2016-06-01

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (≈ 11 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the target channeling efficiency.

  5. Ions ejected from the surface: sputtering induced by swift heavy ion irradiation

    OpenAIRE

    Alzaher, Ibrahim

    2011-01-01

    Ion irradiation of solids leads to a deposition of its energy along the ion path. The energy deposited creates damage in the target as well as leads to the sputtering of neutral and charged particles. In this work we studied the damage induced by slow and swift ions in matter. We studied also the sputtering of secondary ions induced by swift heavy ion irradiation. We have measured the damage cross section of the surface of the Titanium (Insulator surface) and of the graphite (Conductor surfac...

  6. Defect structure induced by ion injection in WC-Co

    Energy Technology Data Exchange (ETDEWEB)

    Baik, S.-I. [Department of Materials Science and Engineering, Seoul National University, San 56-1 Silim-dong Gwanak-gu, Seoul 151-744 (Korea, Republic of); Choi, E.-G.; Jun, J.-H. [Research Institute of Industrial Science and Technology, Nam-gu Pohang (Korea, Republic of); Kim, Y.-W. [Department of Materials Science and Engineering, Seoul National University, San 56-1 Silim-dong Gwanak-gu, Seoul 151-744 (Korea, Republic of)], E-mail: youngwk@snu.ac.kr

    2008-04-15

    Microstructural changes were investigated when nitrogen ions were injected into a WC-Co surface. The crystallographic orientation of WC, relative to the incoming ions, affects the number density and the types of dislocations, but the penetration depth from the accelerated ions was constant regardless of grain orientation. It is believed that the injected nitrogen atoms replaced existing carbon atoms in the highly defective region.

  7. Development of C{sup 6+} laser ion source and RFQ linac for carbon ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sako, T., E-mail: takayuki1.sako@toshiba.co.jp; Yamaguchi, A.; Sato, K. [Toshiba Corporation, Yokohama 235-8522 (Japan); Goto, A.; Iwai, T.; Nayuki, T.; Nemoto, K.; Kayama, T. [Cancer Research Center, Yamagata University Faculty of Medicine, Yamagata 990-9585 (Japan); Takeuchi, T. [Accelerator Engineering Corporation, Chiba 263-0043 (Japan)

    2016-02-15

    A prototype C{sup 6+} injector using a laser ion source has been developed for a compact synchrotron dedicated to carbon ion radiotherapy. The injector consists of a laser ion source and a 4-vane radio-frequency quadrupole (RFQ) linac. Ion beams are extracted from plasma and directly injected into the RFQ. A solenoid guides the low-energy beams into the RFQ. The RFQ is designed to accelerate high-intensity pulsed beams. A structure of monolithic vanes and cavities is adopted to reduce its power consumption. In beam acceleration tests, a solenoidal magnetic field set between the laser ion source and the RFQ helped increase both the peak currents before and after the RFQ by a factor of 4.

  8. Development of C6+ laser ion source and RFQ linac for carbon ion radiotherapy

    Science.gov (United States)

    Sako, T.; Yamaguchi, A.; Sato, K.; Goto, A.; Iwai, T.; Nayuki, T.; Nemoto, K.; Kayama, T.; Takeuchi, T.

    2016-02-01

    A prototype C6+ injector using a laser ion source has been developed for a compact synchrotron dedicated to carbon ion radiotherapy. The injector consists of a laser ion source and a 4-vane radio-frequency quadrupole (RFQ) linac. Ion beams are extracted from plasma and directly injected into the RFQ. A solenoid guides the low-energy beams into the RFQ. The RFQ is designed to accelerate high-intensity pulsed beams. A structure of monolithic vanes and cavities is adopted to reduce its power consumption. In beam acceleration tests, a solenoidal magnetic field set between the laser ion source and the RFQ helped increase both the peak currents before and after the RFQ by a factor of 4.

  9. Development of C⁶⁺ laser ion source and RFQ linac for carbon ion radiotherapy.

    Science.gov (United States)

    Sako, T; Yamaguchi, A; Sato, K; Goto, A; Iwai, T; Nayuki, T; Nemoto, K; Kayama, T; Takeuchi, T

    2016-02-01

    A prototype C(6+) injector using a laser ion source has been developed for a compact synchrotron dedicated to carbon ion radiotherapy. The injector consists of a laser ion source and a 4-vane radio-frequency quadrupole (RFQ) linac. Ion beams are extracted from plasma and directly injected into the RFQ. A solenoid guides the low-energy beams into the RFQ. The RFQ is designed to accelerate high-intensity pulsed beams. A structure of monolithic vanes and cavities is adopted to reduce its power consumption. In beam acceleration tests, a solenoidal magnetic field set between the laser ion source and the RFQ helped increase both the peak currents before and after the RFQ by a factor of 4. PMID:26932119

  10. Gated ion transport through dense carbon nanotube membranes.

    Science.gov (United States)

    Yu, Miao; Funke, Hans H; Falconer, John L; Noble, Richard D

    2010-06-23

    Gated ion diffusion is found widely in hydrophobic biological nanopores, upon changes in ligand binding, temperature, transmembrane voltage, and mechanical stress. Because water is the main media for ion diffusion in these hydrophobic biological pores, ion diffusion behavior through these nanochannels is expected to be influenced significantly when water wettability in hydrophobic biological nanopores is sensitive and changes upon small external changes. Here, we report for the first time that ion diffusion through highly hydrophobic nanopores (approximately 3 nm) showed a gated behavior due to change of water wettability on hydrophobic surface upon small temperature change or ultrasound. Dense carbon nanotube (CNT) membranes with both 3-nm CNTs and 3-nm interstitial pores were prepared by a solvent evaporation process and used as a model system to investigate ion diffusion behavior. Ion diffusion through these membranes exhibited a gated behavior. The ion flux was turned on and off, apparently because the water wettability of CNTs changed. At 298 K, ion diffusion through dense CNT membranes stopped after a few hours, but it dramatically increased when the temperature was increased 20 K or the membrane was subjected to ultrasound. Likewise, water adsorption on dense CNT membranes increased dramatically at a water activity of 0.53 when the temperature increased from 293 to 306 K, indicating capillary condensation. Water adsorption isotherms of dense CNT membranes suggest that the adsorbed water forms a discontinuous phase at 293 K, but it probably forms a continuous layer, probably in the interstitial CNT regions, at higher temperatures. When the ion diffusion channel was opened by a temperature increase or ultrasound, ions diffused through the CNT membranes at a rate similar to bulk diffusion in water. This finding may have implications for using CNT membrane for desalination and water treatment. PMID:20504021

  11. Coprecipitation of alkali metal ions with calcium carbonate

    International Nuclear Information System (INIS)

    The coprecipitation of alkali metal ions Li+, Na+, K+ and Rb+ with calcium carbonate has been studied experimentally and the following results have been obtained: (1) Alkali metal ions are more easily coprecipitated with aragonite than with calcite. (2) The relationship between the amounts of alkali metal ions coprecipitated with aragonite and their ionic radii shows a parabolic curve with a peak located at Na+ which has approximately the same ionic radius as Ca2+. (3) However, the amounts of alkali metal ions coprecipitated with calcite decrease with increasing ionic radius of alkali metals. (4) Our results support the hypothesis that (a) alkali metals are in interstitial positions in the crystal structure of calcite and do not substitute for Ca2+ in the lattice, but (b) in aragonite, alkali metals substitute for Ca2+ in the crystal structure. (5) Magnesium ions in the parent solution increase the amounts of alkali metal ions (Li+, Na+, K+ and Rb+) coprecipitated with calcite but decrease those with aragonite. (6) Sodium-bearing aragonite decreases the incorporation of other alkali metal ions (Li+, K+ and Rb+) into the aragonite. (author)

  12. Increased effectiveness of carbon ions in the production of reactive oxygen species in normal human fibroblasts

    International Nuclear Information System (INIS)

    The production of reactive oxygen species (ROS), especially superoxide anions (O2·-), is enhanced in many normal and tumor cell types in response to ionizing radiation. The influence of ionizing radiation on the regulation of ROS production is considered as an important factor in the long-term effects of irradiation (such as genomic instability) that might contribute to the development of secondary cancers. In view of the increasing application of carbon ions in radiation therapy, we aimed to study the potential impact of ionizing density on the intracellular production of ROS, comparing photons (X-rays) with carbon ions. For this purpose, we used normal human cells as a model for irradiated tissue surrounding a tumor. By quantifying the oxidization of Dihydroethidium (DHE), a fluorescent probe sensitive to superoxide anions, we assessed the intracellular ROS status after radiation exposure in normal human fibroblasts, which do not show radiation-induced chromosomal instability. After 3–5 days post exposure to X-rays and carbon ions, the level of ROS increased to a maximum that was dose dependent. The maximum ROS level reached after irradiation was specific for the fibroblast type. However, carbon ions induced this maximum level at a lower dose compared with X-rays. Within ∼1 week, ROS decreased to control levels. The time-course of decreasing ROS coincides with an increase in cell number and decreasing p21 protein levels, indicating a release from radiation-induced growth arrest. Interestingly, radiation did not act as a trigger for chronically enhanced levels of ROS months after radiation exposure. (author)

  13. Self-organized formation of metal-carbon nanostructures by hyperthermal ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hannstein, I.K.

    2006-04-26

    The quasi-simultaneous deposition of mass-selected hyperthermal carbon and metal ions results in a variety of interesting film morphologies, depending on the metal used and the deposition conditions. The observed features are of the order of a few nanometres and are therefore interesting for future potential applications in the various fields of nanotechnology. The present study focuses on the structural analysis of amorphous carbon films containing either copper, silver, gold, or iron using amongst others Rutherford Backscattering Spectroscopy, High Resolution Transmission Electron Microscopy, and Energy Dispersive X-Ray Spectroscopy. The film morphologies found are as follows: copper-containing films consist of copper nanoclusters with sizes ranging from about 3 to 9 nm uniformly distributed throughout the amorphous carbon matrix. The cluster size hereby rises with the copper content of the films. The silver containing films decompose into a pure amorphous carbon film with silver agglomerates at the surface. Both, the gold- and the iron-containing films show a multilayer structure of metal-rich layers with higher cluster density separated by metal-depleted amorphous carbon layers. The layer distances are of the order of up to 15 nm in the case of gold-carbon films and 7 nm in the case of iron-carbon films. The formation of theses different structures cannot be treated in the context of conventional self-organization mechanisms basing upon thermal diffusion and equilibrium thermodynamics. Instead, an ion-induced atomic transport, sputtering effects, and the stability of small metal clusters were taken into account in order to model the structure formation processes. A similar multilayer morphology was recently also reported in the literature for metal-carbon films grown by magnetron sputtering techniques. In order to investigate, whether the mechanisms are the same as in the case of the ion beam deposited films described above, first experiments were conducted

  14. Pore-size ion-size correlations for carbon supercapacitors

    Science.gov (United States)

    Chmiola, John

    2009-08-01

    Carbon supercapacitors, which are energy storage devices that use ion adsorption on the surface of highly porous materials to store charge, have numerous advantages over other power-source technologies, but could realize further gains if their electrodes were properly optimized. This could lead to fleet-wide improvements in economy, performance, lifetime and environmental impact of Hybrid Electric Vehicles (HEVs), as well as enable or advance many other applications. To determine correlations between ion-size and pore-size in carbon supercapacitors, we generated a well-characterized set of porous carbide-derived carbons (CDC) with average pore sizes from 0.6 to 2.25 nm and used them to probe the limits of understanding. Performing the first systematic study of the effect of pore size on capacitance showed that, in general, decreasing the pore size below the size of the solvated ion, or to precisely the size of the ionic liquid ion, allowed higher accumulation of charge. Using CDC with properly tuned porosity showed excellent performance in H2SO 4, ˜200 F/g, and performance superior to all prior reported results in organic (CH3CH2)4NBF4 (TEABF 4) electrolytes as well as l-ethyl-3-methyl immidazolium bis-(trifluoromethanesulfonyl)imide (EMI-TFSI) ionic liquid, ˜150 F/g. This work conclusively showed that precisely matching the pore size with the ion size is the key factor for maximizing capacitance. Understanding that pores significantly larger than the effective ion size do not have large contributions to energy storage, work on dense porous CDC films on conductive substrates showed ˜100% larger volumetric capacitance than any previously reported. Depositing patterned films of carbide and electrical contacts could lead to microfabricated energy storage devices directly on a chip, or built up in layers for performances yet unrealized.

  15. Dual ion beam deposition of carbon films with diamondlike properties

    Science.gov (United States)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1984-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamondlike films generated by sputtering a graphite target.

  16. Long-term Autophagy and Nrf2 Signaling in the Hippocampi of Developing Mice after Carbon Ion Exposure

    Science.gov (United States)

    Ye, Fei; Zhao, Ting; Liu, Xiongxiong; Jin, Xiaodong; Liu, Xinguo; Wang, Tieshan; Li, Qiang

    2015-12-01

    To explore charged particle radiation-induced long-term hippocampus damage, we investigated the expression of autophagy and antioxidant Nrf2 signaling-related proteins in the mouse hippocampus after carbon ion radiation. Heads of immature female Balb/c mice were irradiated with carbon ions of different LETs at various doses. Behavioral tests were performed on the mice after maturation. Acute and chronic expression of LC3-II, p62/SQSTM1, nuclear Nrf2, activated caspase-3 and the Bax/Bcl-2 ratio were measured in the hippocampi. Secondary X-ray insult was adopted to amplify potential damages. Long-term behavioral changes were observed in high-LET carbon ion-irradiated mice. There were no differences in the rates of LC3-II induction and p62/SQSTM1 degradation compared to the control group regardless of whether the mice received the secondary X-ray insult. A high nuclear Nrf2 content and low apoptosis level in hippocampal cells subjected to secondary X-rays were observed for the mice exposed to relatively low-LET carbon ions. Therefore, carbon ion exposure in the immature mouse led to an LET-dependent behavioral change after maturation. Although autophagy was intact, the persistently high nuclear Nrf2 content in the hippocampus might account for the unchanged behavioral pattern in mice exposed to the relatively low-LET carbon ions and the subsequent increased radioresistance of the hippocampus.

  17. Effect of magnetic field on light-induced ion drift

    International Nuclear Information System (INIS)

    Paper is devoted to theoretical study of the force aspect of magnetic field effect on the light-induced ion drift. One studied three-component (electrons, single-charge positive ions and neutral atoms) slightly ionized gas in the constant homogeneous magnetic field. One derived formulae describing ion drift under the effect of mobile monochromatic light wave. It was determined that in slightly ionized gas at superposition of the external magnetic field a component of light-induced ion drift speed that was transverse to the radiation propagation direction might occur. One estimates the magnetic field value when the projection of ion drift speed on radiation direction should change its sign. In this case, one may observe anomalous light-induced ion drift

  18. Heavy-ion-induced fission reactions

    International Nuclear Information System (INIS)

    Fission-cross-section excitation functions were measured from near threshold to approx. 10 MeV/nucleon using heavy-ion beams from the Brookhaven National Laboratory three-stage Tandem Accelerator Facility. The systems studied included 210Po formed in 12C and 18O induced reactions, 186Os formed in 9Be, 12C, 16O, and 26Mg reactions, 158Er formed in 16O, 24Mg, 32S, and 64Ni reactions. In addition the composite systems 204206, 208Po formed with 16O and 18O projectiles were studied. The measured fission excitation functions along with previous data from 4He and 11B bombardments for the 186Os and 210Po systems and recent data on the 200Pb system are compared to predictions from a statistical model using recent fission-barrier calculations from A. Sierk. Comparisons of calculated and measured fission excitation functions show good overall agreement between data and calculations and between calculations with two different level-density functions. It is concluded that the barriers from Sierk give a good description of both the mass and angular momentum dependence of fission barriers in this region

  19. Laser Induced Fluorescence of the Iodine Ion

    Science.gov (United States)

    Hargus, William

    2014-10-01

    Iodine (I2) has been considered as a potential electrostatic spacecraft thruster propellant for approximately 2 decades, but has only recently been demonstrated. Energy conversion efficiency appears to be on par with xenon without thruster modification. Intriguingly, performance appears to exceed xenon at high acceleration potentials. As part of a continuing program for the development of non-intrusive plasma diagnostics for advanced plasma spacecraft propulsion, we have identified the I II 5d5D4 o state as metastable, and therefore containing a reservoir of excited state ions suitable for laser probing. The 5d5D4 o - 6p5P3 transition at 695.878 nm is convenient for diode laser excitation with the 5s5S2 o - 6p5P3 transition at 516.12 nm as an ideal candidate for non-resonant fluorescence collection. We have constructed a Penning type iodine microwave discharge lamp optimized for I II production for table-top measurements. This work demonstrates I II laser-induced fluorescence in a representative iodine discharge and will validate our previous theoretical work based on the limited available historical I II spectral data.

  20. Isotopic anomaly for carbon ions in an electron cyclotron resonance ion source.

    Science.gov (United States)

    Drentje, A G; Kitagawa, A; Muramatsu, M

    2010-02-01

    In many experiments methods were applied to increase the highly charged ion output from an electron cyclotron resonance ion source; the gas-mixing method is still generally being applied. The dominant role of the masses of the ions in the gas-mixture was apparent. Two basically differing mechanisms could to first order explain most of the observations. A significant mass effect showed up in a mixture of oxygen isotopes, the so-called oxygen anomaly; so far that effect could be explained in zeroth order only. The anomaly was observed later for nitrogen isotopes as well. In the present experiment it is shown that the anomaly also exists for carbon isotopes, where the necessity of feeding the source with carbon-hydrogen compounds brings about an essential different experimental fact. PMID:20192439

  1. The temperature and carbonate ion influence on Pleistocene high latitude planktonic foraminiferal carbon isotopic records

    Science.gov (United States)

    Charles, C.; Foreman, A. D.; Munson, J.; Slowey, N. C.; Hodell, D. A.

    2014-12-01

    Establishing a credible record of the carbon isotopic composition of high latitude surface ocean DIC over ice ages has been an enormous challenge, because the possible archives of this important variable in deep sea sediments all incorporate complex effects of the biomineralization process. For example, culture experiments (by Spero and colleagues) demonstrate a strong temperature and carbonate ion effect on the carbon isotopic composition of G. bulloides--the taxon of planktonic foraminifera that is most abundant in the majority of subpolar sediment sequences. Here we capitalize on the fortuitous observation of exceptionally strong covariation between the oxygen and carbon isotopic composition of G. bulloides in multiple sediment sequences from the Benguela upwelling region. The covariation is most clear during Marine Isotopic Stage 3 (an interval when the isotopic composition of the seawater was least variable) and undoubtedly results from the precipitation of tests under variable conditions of temperature and carbonate ion. The unusually clear isotopic relationship in planktonic foraminifera observed off Namibia constitutes a field calibration of the biomineralization effects observed in culture, and we apply it to previously published high latitude carbon isotopic records throughout the Southern Ocean. We find that many of the excursions toward lower planktonic foraminiferal δ13C that have been interpreted previously as the upwelling of nutrient rich water during deglaciations are better explained as increases in upper ocean temperature and carbonate ion. Conversely, the excursions toward high δ13C during ice age intervals that have been interpreted previously as increased export production (purportedly stimulated by dust) are also better explained by temperature and carbonate ion variability. After removal of the inferred temperature and carbonate ion signal from the planktonic foraminiferal time series, the residual is essentially (but not exactly) the same

  2. Carbon ion radiotherapy. Clinical study and future prospect

    International Nuclear Information System (INIS)

    At present, most of the patients receiving carbon ion radiotherapy at National Institute of Radiological Sciences (NIRS) visit the clinic seeking this specific modality, and it is difficult to obtain consent for a randomized controlled study from these patients and it may be unnecessary to conduct a phase III trial. However, in selected tumors where the high-linear energy transfer (LET) benefit could be appreciated, we can participate in randomized studies. Finally, studies aimed at clarifying the usefulness of carbon ion radiotherapy and elucidating any advantages from hypo-fractionation should be considered. A multi-institutional prospective non-randomized concurrent phase II clinical trial is one such new approach, and it will be proposed not only to the Japanese, but also to the international community of particle therapy and radiation oncology. (author)

  3. Analysis of mutagenic effects induced by carbon beams at different LET in a red yeast strain

    International Nuclear Information System (INIS)

    To evaluate inactive and mutagenic effects of carbon beam at different LET, the inactivation cross section and mutation cross section induced by carbon beams of different LET values were investigated in a red yeast strain Rhodotorula glutinis AY 91015. It was found that the maximum inactivation cross section of 4.37μm2, which was very close to the average nucleus cross section, was at LET of 120.0 keV/μm. The maximum mutation cross section was at LET of 96.0 keV/μm. Meanwhile, the highest mutagenicity of carbon ion was found around 58.2 keV/μm. It implied that the most efficient LET to induce mutation in survival yeasts was 58.2 keV/μm, which corresponded to energy of 35 MeV/u carbon beam. The most effective carbon beam to induce inactivation and mutation located at different energy region. (authors)

  4. Activated carbon is an electron-conducting amphoteric ion adsorbent

    CERN Document Server

    Biesheuvel, P M

    2015-01-01

    Electrodes composed of activated carbon (AC) particles can desalinate water by ion electrosorption. To describe ion electrosorption mathematically, accurate models are required for the structure of the electrical double layers (EDLs) that form within electrically charged AC micropores. To account for salt adsorption also in uncharged ACs, an "attraction term" was introduced in modified Donnan models for the EDL structure in ACs. Here it will be shown how instead of using an attraction term, chemical information of the surface structure of the carbon-water interface in ACs can be used to construct an alternative EDL model for ACs. This EDL model assumes that ACs contain both acidic groups, for instance due to carboxylic functionalities, and basic groups, due to the adsorption of protons to the carbon basal planes. As will be shown, this "amphoteric Donnan" model accurately describes various data sets for ion electrosorption in ACs, for solutions of NaCl, of CaCl2, and mixtures thereof, as function of the exter...

  5. Biological systems: from water radiolysis to carbon ion radiotherapy

    Science.gov (United States)

    Beuve, Michael; Moreau, Jean-Michel; Rodriguez, Claire; Testa, Etienne

    2015-07-01

    Hadron therapy is an innovative cancer treatment method based on the acceleration of light ions at high energy. In addition to their interesting profile of dose deposition, which ensures accurate targeting of localized tumors, carbon ions offer biological properties that lead to an efficient treatment for radio- and chemo-resistant tumors and to provide a boost for tumors in hypoxia. This paper is a short review of the progress in theoretical, experimental, fundamental and applied research, aiming at understanding the origin of the biological benefits of light ions better. As a limit of such a vast and multidisciplinary domain, this review adopts the point of view of the physicists, leaning on results obtained in connection with CIMAP's IRRABAT platform.

  6. Ion beam induced alignment of semiconductor nanowires

    International Nuclear Information System (INIS)

    Epitaxially grown GaAs nanowires were irradiated with different kinds of energetic ions. The growth substrates were GaAs, and the nanowires grow under an angle of 35 circle. A bending of the nanowires was observed under ion beam irradiation, where the direction and magnitude of the bending depends on the energy, the species, and fluence of the incident ions. By choosing suitable ion beam parameters the nanowires could be realigned towards the ion beam direction. In order to understand the underlying mechanisms, computer simulations of the ion irradiation were done using a special version of TRIM which accounts for the geometry of the nanowires. The simulated distributions indicate vacancy and interstitial formation within the implantation cascade as the key mechanism for bending.

  7. Neutron imaging of ion transport in mesoporous carbon materials.

    Science.gov (United States)

    Sharma, Ketki; Bilheux, Hassina Z; Walker, Lakeisha M H; Voisin, Sophie; Mayes, Richard T; Kiggans, Jim O; Yiacoumi, Sotira; DePaoli, David W; Dai, Sheng; Tsouris, Costas

    2013-07-28

    Neutron imaging is presented as a tool for quantifying the diffusion of ions inside porous materials, such as carbon electrodes used in the desalination process via capacitive deionization and in electrochemical energy-storage devices. Monolithic mesoporous carbon electrodes of ∼10 nm pore size were synthesized based on a soft-template method. The electrodes were used with an aqueous solution of gadolinium nitrate in an electrochemical flow-through cell designed for neutron imaging studies. Sequences of neutron images were obtained under various conditions of applied potential between the electrodes. The images revealed information on the direction and magnitude of ion transport within the electrodes. From the time-dependent concentration profiles inside the electrodes, the average value of the effective diffusion coefficient for gadolinium ions was estimated to be 2.09 ± 0.17 × 10(-11) m(2) s(-1) at 0 V and 1.42 ± 0.06 × 10(-10) m(2) s(-1) at 1.2 V. The values of the effective diffusion coefficient obtained from neutron imaging experiments can be used to evaluate model predictions of the ion transport rate in capacitive deionization and electrochemical energy-storage devices. PMID:23756558

  8. Targeting head and neck cancer stem cells to overcome resistance to photon and carbon ion radiation.

    Science.gov (United States)

    Bertrand, Gérald; Maalouf, Mira; Boivin, Antony; Battiston-Montagne, Priscillia; Beuve, Michael; Levy, Antonin; Jalade, Patrice; Fournier, Claudia; Ardail, Dominique; Magné, Nicolas; Alphonse, Gersende; Rodriguez-Lafrasse, Claire

    2014-02-01

    Although promising new radiation therapy techniques such as hadrontherapy are currently being evaluated in the treatment of head and neck malignancies, local control of head and neck squamous cell carcinoma (HNSCC) remains low. Here, we investigated the involvement of cancer stem-like cells (CSCs) in a radioresistant HNSCC cell line (SQ20B). Stem-like cells SQ20B/SidePopulation(SP)/CD44(+)/ALDH(high) were more resistant to both photon and carbon ion irradiation compared with non-CSCs. This was confirmed by a BrdU labeling experiment, which suggests that CSCs were able to proliferate and to induce tumorigenicity after irradiation. SQ20B/SP/CD44(+)/ALDH(high) were capable of an extended G2/M arrest phase in response to photon or carbon ion irradiation compared with non-CSCs. Moreover, our data strongly suggest that resistance of CSCs may result from an imbalance between exacerbated self-renewal and proliferative capacities and the decrease in apoptotic cell death triggering. In order to modulate these processes, two targeted pharmacological strategies were tested. Firstly, UCN-01, a checkpoint kinase (Chk1) inhibitor, induced the relapse of G2/M arrest and radiosensitization of SQ20B-CSCs. Secondly, all-trans retinoic acid (ATRA) resulted in an inhibition of ALDH activity, and induction of the differentiation and radiosensitization of SQ20B/SP/CD44(+)/ALDH(high) cells. The combination of ATRA and UCN-01 treatments with irradiation drastically decreased the surviving fraction at 2Gy of SQ20B-CSCs from 0.85 to 0.38 after photon irradiation, and from 0.45 to 0.21 in response to carbon ions. Taken together, our results suggest that the combination of UCN-01 and ATRA represent a promising pharmacological-targeted strategy that significantly sensitizes CSCs to photon or carbon ion radiation. PMID:23955575

  9. Hard Carbon Wrapped in Graphene Networks as Lithium Ion Battery Anode

    International Nuclear Information System (INIS)

    Hard carbon enveloped with graphene networks was fabricated by a facile and scalable method. In the constructed architecture, hard carbon offers large lithium storage and flexible graphene layers can provide a highly conductive matrix for enabling good contact between particles and facilitate the diffusion and transport of electrons and ions. As a consequence, the hybrid anode exhibits enhanced reversible capacity (500 mAh g−1 at current density of 20 mA g−1), rate capability (400 mAh g−1 at 0.2 C, 290 mAh g−1 at 1 C, 250 mAh g−1 at 2 C, and 200 mAh g−1 at 5 C, 1C = 400 mA g−1) and cycle performance. We believe that the outstanding synergetic effect between the graphene networks and the hard carbon structures induces the superior lithium storage performance of the overall electrode by maximally utilizing the electrochemically active graphene and hard carbon particles. As far as we know, the hard carbon/graphene hybrids were firstly fabricated as anode in lithium-ion batteries

  10. Substrate-induced strain in carbon nanodisks

    International Nuclear Information System (INIS)

    Graphitic nanodisks of typically 20–50 nm in thickness, produced by the so-called Kvaerner Carbon Black and Hydrogen Process were dispersed on gold substrate and investigated by atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and confocal Raman spectroscopy. The roughness of the gold surface was drastically changed by annealing at 400 °C. AFM measurements show that this change in the surface roughness induces changes also in the topography of the nanodisks, as they closely follow the corrugation of the gold substrate. This leads to strained nanodisks, which is confirmed also by confocal Raman microscopy. We found that the FE-SEM contrast obtained from the disks depends on the working distance used during the image acquisition by In-lens detection, a phenomenon which we explain by the decrease in the amount of electrons reaching the detector due to diffraction. This process may affect the image contrast in the case of other layered materials, like hexagonal boron nitride, and other planar hybrid nanostructures, too. - Highlights: • Bending of carbon nanodisks is induced by the roughness of the gold substrate. • Confocal Raman microscopy shows a compressive strain induced in the nanodisks. • The electron microscopy contrast of nanodisks depends on the working distance

  11. Carbon/SnO2/carbon core/shell/shell hybrid nanofibers: tailored nanostructure for the anode of lithium ion batteries with high reversibility and rate capacity

    Science.gov (United States)

    Kong, Junhua; Liu, Zhaolin; Yang, Zhengchun; Tan, Hui Ru; Xiong, Shanxin; Wong, Siew Yee; Li, Xu; Lu, Xuehong

    2012-01-01

    A carbon/SnO2/carbon core/shell/shell hybrid nanofibrous mat was successfully prepared via single-spinneret electrospinning followed by carbonization and hydrothermal treatment. The morphology and structure of carbon/SnO2/carbon hybrid nanofibers were characterized by field-emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, wide-angle X-ray diffraction and X-ray photoelectron spectroscopy, and their electrochemical properties were studied as an anode in lithium ion batteries (LIBs). It is shown that the designed hybrid nanofibrous mat exhibits excellent electrochemical properties, including high reversible capacity with high columbic efficiency and impressive rate capacity. The greatly enhanced electrochemical performance is mainly due to the morphological stability and reduced diffusion resistance, which are induced by both the carbon core and deposited carbon skin. Furthermore, the embedded and de-aggregated SnO2 nanoparticles in the carbon phase, which are less than 10 nm in size, provide large numbers of reaction sites for lithium ions and ensure complete alloying with them.A carbon/SnO2/carbon core/shell/shell hybrid nanofibrous mat was successfully prepared via single-spinneret electrospinning followed by carbonization and hydrothermal treatment. The morphology and structure of carbon/SnO2/carbon hybrid nanofibers were characterized by field-emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, wide-angle X-ray diffraction and X-ray photoelectron spectroscopy, and their electrochemical properties were studied as an anode in lithium ion batteries (LIBs). It is shown that the designed hybrid nanofibrous mat exhibits excellent electrochemical properties, including high reversible capacity with high columbic efficiency and impressive rate capacity. The greatly enhanced electrochemical performance is mainly due to the morphological stability and reduced diffusion

  12. Carbon Ionic Conductors for use in Novel Carbon-Ion Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Franklin H. Cocks; W. Neal Simmons; Paul A. Klenk

    2005-11-01

    Carbon-consuming fuel cells have many potential advantages, including increased efficiency and reduced pollution in power generation from coal. A large amount of work has already been done on coal fuel cells that utilize yttria-stabilized zirconium carbide as an oxygen-ion superionic membrane material. But high-temperature fuel cells utilizing yttria-stabilized zirconium require partial combustion of coal to carbon monoxide before final oxidation to carbon dioxide occurs via utilization of the oxygen- ion zirconia membrane. A carbon-ion superionic membrane material would enable an entirely new class of carbon fuel cell to be developed, one that would use coal directly as the fuel source, without any intervening combustion process. However, a superionic membrane material for carbon ions has not yet been found. Because no partial combustion of coal would be required, a carbon-ion superionic conductor would allow the direct conversion of coal to electricity and pure CO{sub 2} without the formation of gaseous pollutants. The objective of this research was to investigate ionic lanthanide carbides, which have an unusually high carbon-bond ionicity as potential superionic carbide-ion conductors. A first step in this process is the stabilization of these carbides in the cubic structure, and this stabilization has been achieved via the preparation of pseudobinary lanthanide carbides. The diffusion rates of carbon have been measured in these carbides as stabilized to preserve the high temperature cubic structure down to room temperature. To prepare these new compounds and measure these diffusion rates, a novel, oxide-based preparation method and a new C{sup 13}/C{sup 12} diffusion technique have been developed. The carbon diffusion rates in La{sup 0.5}Er{sup 0.5}C{sub 2}, Ce{sup 0.5}Er{sup 0.5}C{sub 2}, and La{sup 0.5}Y{sup 0.5}C{sub 2}, and Ce{sup 0.5}Tm0.5C{sub 2} modified by the addition of 5 wt %Be{sub 2}C, have been determined at temperatures from 850 C to 1150 C. The

  13. Fragment kinetic energy distributions in ion induced CO2 fragmentation

    International Nuclear Information System (INIS)

    The dissociation of CO3+2 formed in heavy ion induced ionization of CO2 has been studied using the technique of time of flight mass spectroscopy with position sensitive ion detector, with 5 MeV/u Si12+ ions as projectiles. The kinetic energy released in the CO3+2→ C+ + O+ + O+ is measured and compared to theoretical ab initio calculations as well as photoionization results.

  14. Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  15. Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  16. Transformation from hollow carbon octahedra to compressed octahedra and their use in lithium-ion batteries

    International Nuclear Information System (INIS)

    Graphical abstract: Schematic illustration of the transformation process from hollow carbon octahedra into deflated balloon-like compressed hollow carbon octahedra ▪. Highlights: ► We demonstrate the in situ template synthesis of hollow carbon octahedra. ► The shell thickness of hollow carbon octahedra is only 2.5 nm. ► Morphology transformation could be realized by extending of reaction time. ► The hollow structures show reversible capacity as 353 mAh g−1 after 100 cycles. -- Abstract: Hollow carbon octahedra with an average size of 300 nm and a shell thickness of 2.5 nm were prepared by a reaction starting from ferrocene and Mg(CH3COO)2·4H2O at 700 °C for 10 h. They became compressed and turned into deflated balloon-like octahedra when the reaction time was increased to 16 h. It was proposed that the gas pressure generated during the reaction process induced the transformation from broken carbon hollow octahedra into deflated balloon-like compressed octahedra. X-ray powder diffraction and Raman spectroscopy indicate that the as-obtained carbon products possess a graphitic structure and high-resolution transmission electron microscopy images indicate that they have low crystallinity. Their application as an electrode shows reversible capacity of 353 mAh g−1 after 100 cycles in the charge/discharge experiments of secondary lithium ion batteries.

  17. Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes

    Science.gov (United States)

    2016-01-01

    The cost and practicality of greenhouse gas removal processes, which are critical for environmental sustainability, pivot on high-value secondary applications derived from carbon capture and conversion techniques. Using the solar thermal electrochemical process (STEP), ambient CO2 captured in molten lithiated carbonates leads to the production of carbon nanofibers (CNFs) and carbon nanotubes (CNTs) at high yield through electrolysis using inexpensive steel electrodes. These low-cost CO2-derived CNTs and CNFs are demonstrated as high performance energy storage materials in both lithium-ion and sodium-ion batteries. Owing to synthetic control of sp3 content in the synthesized nanostructures, optimized storage capacities are measured over 370 mAh g–1 (lithium) and 130 mAh g–1 (sodium) with no capacity fade under durability tests up to 200 and 600 cycles, respectively. This work demonstrates that ambient CO2, considered as an environmental pollutant, can be attributed economic value in grid-scale and portable energy storage systems with STEP scale-up practicality in the context of combined cycle natural gas electric power generation.

  18. Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes.

    Science.gov (United States)

    Licht, Stuart; Douglas, Anna; Ren, Jiawen; Carter, Rachel; Lefler, Matthew; Pint, Cary L

    2016-03-23

    The cost and practicality of greenhouse gas removal processes, which are critical for environmental sustainability, pivot on high-value secondary applications derived from carbon capture and conversion techniques. Using the solar thermal electrochemical process (STEP), ambient CO2 captured in molten lithiated carbonates leads to the production of carbon nanofibers (CNFs) and carbon nanotubes (CNTs) at high yield through electrolysis using inexpensive steel electrodes. These low-cost CO2-derived CNTs and CNFs are demonstrated as high performance energy storage materials in both lithium-ion and sodium-ion batteries. Owing to synthetic control of sp(3) content in the synthesized nanostructures, optimized storage capacities are measured over 370 mAh g(-1) (lithium) and 130 mAh g(-1) (sodium) with no capacity fade under durability tests up to 200 and 600 cycles, respectively. This work demonstrates that ambient CO2, considered as an environmental pollutant, can be attributed economic value in grid-scale and portable energy storage systems with STEP scale-up practicality in the context of combined cycle natural gas electric power generation. PMID:27163042

  19. Ion solvation in propylene carbonate and its mixtures with water and methanol

    International Nuclear Information System (INIS)

    Solvodynamic radii and solvation numbers of some ions (including I-) in propylene carbonate as well as their solvodynamic radii in mixtures of propylene carbonate-water and propylene carbonate-methanol were determined. Effect of medium components and solvated ion characteristics on the process of ion solvation was considered. It is shown that small size anions in propylene carbonate are weakly solvated, whereas bulky lightly polarized anions interact strongly with the solvent. Addition of water or methanol to propylene carbonate leads to intensification of ion solvation

  20. Carbon-cluster formation from polymers caused by MeV-ion impacts and keV-cluster-ion impacts

    Science.gov (United States)

    Diehnelt, C. W.; van Stipdonk, M. J.; Schweikert, E. A.

    1999-06-01

    It has been observed that under MeV-ion bombardment of a polymer, such as polycarbonate (PC) or polyvinylidene fluoride (PVDF), large quantities of carbon clusters (C-n and CnH-) are generated. However, when PC or PVDF is bombarded with keV atomic ions, very few carbon-cluster ions are produced. This different behavior was attributed to the different sputtering/desorption mechanisms for keV- and MeV-ion impacts. Low-energy keV ions deposit their energy into a solid through nuclear stopping, while MeV ions deposit their energy mainly through electronic stopping. The formation of carbon clusters is thought to be facilitated by the high-temperatures and high-energy densities produced in the region nearest the point of MeV-ion impact, the infratrack region. We have observed extensive carbon-cluster formation from PC and PVDF under keV-cluster-ion bombardment. Despite the vastly different velocities of the high- and low-energy projectiles, identical carbon-cluster trends are produced from MeV 252Cf fission fragments and 20-keV C+60 projectile impacts on the same target. This leads us to the conclusion that a polyatomic ion impact, which deposits its kinetic energy near the surface, may create a region of high-temperature and high-energy density that is similar to the infratrack of a MeV-ion impact.

  1. Ion induced dissociation of tetraphenyl iron(III) porphyrin chloride and electron-capture induced dissociation of protoporphyrin IX ions

    International Nuclear Information System (INIS)

    We performed experiments concerning the fragmentation of different porphyrin molecules. Multi-ionisation and ion-induced fragmentation of FeTPPCl''q''+ (q = 1 to 4) have been studied in slow collisions with multiply charged ions. We have shown also electron-capture induced dissociation of protoporphyrin cations, where two electrons in two successive have been captured in order to convert it to the corresponding even-electron anions. All fragmentation processes are discussed in terms of charge mobility.

  2. Carbonate ion-enriched hot spring water promotes skin wound healing in nude rats.

    Directory of Open Access Journals (Sweden)

    Jingyan Liang

    Full Text Available Hot spring or hot spa bathing (Onsen is a traditional therapy for the treatment of certain ailments. There is a common belief that hot spring bathing has therapeutic effects for wound healing, yet the underlying molecular mechanisms remain unclear. To examine this hypothesis, we investigated the effects of Nagano hot spring water (rich in carbonate ion, 42°C on the healing process of the skin using a nude rat skin wound model. We found that hot spring bathing led to an enhanced healing speed compared to both the unbathed and hot-water (42°C control groups. Histologically, the hot spring water group showed increased vessel density and reduced inflammatory cells in the granulation tissue of the wound area. Real-time RT-PCR analysis along with zymography revealed that the wound area of the hot spring water group exhibited a higher expression of matrix metalloproteinases-2 and -9 compared to the two other control groups. Furthermore, we found that the enhanced wound healing process induced by the carbonate ion-enriched hot spring water was mediated by thermal insulation and moisture maintenance. Our results provide the evidence that carbonate ion-enriched hot spring water is beneficial for the treatment of skin wounds.

  3. Carbonate ion-enriched hot spring water promotes skin wound healing in nude rats.

    Science.gov (United States)

    Liang, Jingyan; Kang, Dedong; Wang, Yingge; Yu, Ying; Fan, Jianglin; Takashi, En

    2015-01-01

    Hot spring or hot spa bathing (Onsen) is a traditional therapy for the treatment of certain ailments. There is a common belief that hot spring bathing has therapeutic effects for wound healing, yet the underlying molecular mechanisms remain unclear. To examine this hypothesis, we investigated the effects of Nagano hot spring water (rich in carbonate ion, 42°C) on the healing process of the skin using a nude rat skin wound model. We found that hot spring bathing led to an enhanced healing speed compared to both the unbathed and hot-water (42°C) control groups. Histologically, the hot spring water group showed increased vessel density and reduced inflammatory cells in the granulation tissue of the wound area. Real-time RT-PCR analysis along with zymography revealed that the wound area of the hot spring water group exhibited a higher expression of matrix metalloproteinases-2 and -9 compared to the two other control groups. Furthermore, we found that the enhanced wound healing process induced by the carbonate ion-enriched hot spring water was mediated by thermal insulation and moisture maintenance. Our results provide the evidence that carbonate ion-enriched hot spring water is beneficial for the treatment of skin wounds. PMID:25671581

  4. Biological effects induced by low-density heavy ions in normal human fibroblasts

    International Nuclear Information System (INIS)

    This year we focused on X-ray-induced chromatin breaks in cells pre-treated with low-fluence (1 mGy/7-8 h) helium, carbon and iron ions before applying irradiation with an X-ray challenge dose (1.5 Gy). Chromatin breaks in G1/G0 phase immediately after irradiation were detected using the technique of premature chromosome condensation (PCC) produced by the cell fusion method with mitotic cells. The yield of induced chromatin breaks per cell was estimated to be the number of chromatin fragments in excess of the number of chromatin fragments found in the non-irradiated cells. The results showed that X-ray induced chromatin breaks in cells pretreated with low fluence ion beams was the same level as those in X-ray challenging dose alone. There is evidence that chromatin breaks induced immediately after irradiation have no relation to observed enhancement of X-ray induced mutation in cells pretreated with low fluences of helium and carbon ions. (author)

  5. Modeling ion-induced electrons in the High Current Experiment

    International Nuclear Information System (INIS)

    A primary concern for high current ion accelerators is contaminant electrons. These electrons can interfere with the beam ions, causing emittance growth and beam loss. Numerical simulation is a main tool for understanding the interaction of the ion beam with the contaminant electrons, but these simulations then require accurate models of electron generation. These models include ion-induced electron emission from ions hitting the beam pipe walls or diagnostics. However, major codes for modeling ion beam transport are written in different programming languages and used on different computing platforms. For electron generation models to be maximally useful, researchers should be able to use them easily from many languages and platforms. A model of ion-induced electrons including the electron energy distribution is presented here, including a discussion of how to use the Babel software tool to make these models available in multiple languages and how to use the GNU Autotools to make them available on multiple platforms. An application to simulation of the end region of the High Current Experiment is shown. These simulations show formation of a virtual cathode with a potential energy well of amplitude 12.0 eV, approximately six times the most probable energy of the ion-induced electrons. Oscillations of the virtual cathode could lead to possible longitudinal and transverse modulation of the density of the electrons moving out of the virtual cathode

  6. Experimental Investigation of DNA Damage Induced by Heavy Ions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    DNA is considered the critical target for radiobiological effects. It is highly important to study DNAdamage induced by ionizing radiation. Especially DNA double strand breaks have been identified as themost initial damage. In this experiment, DNA double strand breaks induced by heavy ions wereinvestigated with atomic force microscopy (AFM).

  7. Liquid flow-induced energy harvesting in carbon nanotubes: a molecular dynamics study.

    Science.gov (United States)

    Xu, Baoxing; Chen, Xi

    2013-01-28

    Energy harvesting by the flow of a hydrochloric acid-water solution through a carbon nanotube (CNT) is explored using atomistic simulations. Through ion configurations near the CNT wall, the ion drifting velocity is obtained, and the induced voltage along the axial direction is obtained as a function of key material and system parameters, including the applied flow rate, ambient temperature, solution concentration and nanotube diameter. The molecular mechanism of ion hopping and motion is elucidated and related to the variation of material and system parameters. PMID:23223386

  8. Protontherapy versus carbon ion therapy advantages, disadvantages and similarities

    CERN Document Server

    d’Ávila Nunes, Marcos

    2015-01-01

    This book presents a comparison analysis of two cancer treatment therapies: carbon ion therapy and protontherapy. It is divided in 5 sections. The first ones gives the reader a brief history of Radiotherapy and types of radiation. In the second section, the techniques and equipments, including new ones in development such as Cyclinac , Laser and DWA, are described. The third section describes biophysical (such as stopping power and LET) and biological (such as RBE and OER) properties, the fundamental experiments and clinical area. The fourth section presents models and the fifth section compares both techniques, showing advantages and disadvantages of each, and their similarities.

  9. Radiative transitions in highly-stripped carbon-like ions

    International Nuclear Information System (INIS)

    Transition energies and weighted absorption oscillator strength (gf) values are evaluated for a number of dipole-allowed transitions in highly-charged ions Ne4+, Si8+, Ar12+ and Ti16+ belong to the astrophysically important carbon series employing the time-dependent coupled Hartree-Fock (TDCHF) theory. Estimated values compare favourably with other existing results and the new ones repoted here may constitute a useful set for reference. The large-Z behaviour of the gf values is also examined. (orig.)

  10. Relationship between telomere length and radiosensitivity of human cancer cell lines induced by heavy ion irradiation

    International Nuclear Information System (INIS)

    Telomere length is associated with both cancer incidence and cancer mortality. Low linear energy transfer (LET) induced telomere shortening and change in telomerase activity have been studied. However, no information about high LET induced telomere length and telomerase activity alteration was available currently. Here we investigated carbon ions irradiation induced telomerase activity and its expression in mRNA and protein levels. Results indicated that one of the components for telomerase, human telomerase reverse transcriptase (hTERT), was significantly affected by carbon ions irradiation, thus regulated telomerase activity after ionizing irradiation. For further investigate factors involved in telomerase activity, four different cell lines were used. BRCA1 and DNA-PK have been identified to be associated with telomerase activity regulation. In summary, the radiosensitivity of human cancer cell lines after carbon ions irradiation is related to telomerase activity, which is directly regulated by hTERT expression, BRCA1 and DNA-PK statues may play important parts in this regulation. (author)

  11. Regeneration of spent powdered activated carbon saturated with inorganic ions by cavitation united with ion exchange method.

    Science.gov (United States)

    Li, Gang; Gao, Hong; Li, Yansheng; Yang, Huixin

    2011-06-01

    Using ion exchange resin as transfer media, regenerate powdered activated carbon (PAC) adsorbed inorganic ions by cavitation to enhance the transfer; we studied how the regeneration time and the mass ratio of resin and PAC influence the regeneration rate respectively through re-adsorption. The result showed that the effective regeneration of PAC saturated with inorganic ions was above 90% using ion exchange resin as media and transfer carrier, the quantity of PAC did not reduced but activated in the process. PMID:25084579

  12. Ion induced x-ray emission

    International Nuclear Information System (INIS)

    Three types of perturbation theory have been used to describe inner shell vacancy production by light to medium ion bombardment. Inclusion of Coulomb deflection and binding effects in the plane wave Born approximation is discussed. More recently this relativistic Coulomb deflection corrected perturbed stationary state theory has been extended to include energy loss effects. This ECPSSR theory is one of the most successful in predicting inner shell ionisation cross sections for both K and L shells, provided the projectile to target atomic number ratio is less than about 0.3 and, for the heavier ions, electron capture processes by the projectile are included

  13. Ion irradiation of electronic-type-separated single wall carbon nanotubes: A model for radiation effects in nanostructured carbon

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Jamie E. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Cress, Cory D.; Messenger, Scott R.; Weaver, Brad D. [Electronics Science and Technology Division, United States Naval Research Laboratory, Washington, D.C. 20375 (United States); Helenic, Alysha R.; Landi, Brian J. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Chemical and Biomedical Engineering, Rochester Institute of Technology, Rochester, New York 14623 (United States); Schauerman, Chris M. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Golisano Institute of Sustainability, Rochester Institute of Technology, Rochester, New York 14623 (United States); DiLeo, Roberta A.; Cox, Nathanael D. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Microsystems Engineering, Rochester Institute of Technology, Rochester, New York 14623 (United States); Hubbard, Seth M. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Microsystems Engineering, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Physics, Rochester Institute of Technology, Rochester, New York 14623 (United States)

    2012-08-01

    The structural and electrical properties of electronic-type-separated (metallic and semiconducting) single wall carbon nanotube (SWCNT) thin-films have been investigated after irradiation with 150 keV {sup 11}B{sup +} and 150 keV {sup 31}P{sup +} with fluences ranging from 10{sup 12} to 10{sup 15} ions/cm{sup 2}. Raman spectroscopy results indicate that the ratio of the Raman D to G Prime band peak intensities (D/G Prime ) is a more sensitive indicator of SWCNT structural modification induced by ion irradiation by one order of magnitude compared to the ratio of the Raman D to G band peak intensities (D/G). The increase in sheet resistance (R{sub s}) of the thin-films follows a similar trend as the D/G Prime ratio, suggesting that the radiation induced variation in bulk electrical transport for both electronic-types is equal and related to localized defect generation. The characterization results for the various samples are compared based on the displacement damage dose (DDD) imparted to the sample, which is material and damage source independent. Therefore, it is possible to extend the analysis to include data from irradiation of transferred CVD-graphene films on SiO{sub 2}/Si substrates using 35 keV C{sup +} ions, and compare the observed changes at equivalent levels of ion irradiation-induced damage to that observed in the SWCNT thin-film samples. Ultimately, a model is developed for the prediction of the radiation response of nanostructured carbon materials based on the DDD for any incident ion with low-energy recoil spectra. The model is also related to the defect concentration, and subsequently the effective defect-to-defect length, and yields a maximum defect concentration (minimum defect-to-defect length) above which the bulk electrical transport properties in SWCNT thin-films and large graphene-based electronic devices rapidly degrade when exposed to harsh environments.

  14. EUD-based biological optimization for carbon ion therapy

    International Nuclear Information System (INIS)

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  15. EUD-based biological optimization for carbon ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brüningk, Sarah C., E-mail: sarah.brueningk@icr.ac.uk; Kamp, Florian; Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, Ismaninger Str. 22, München 81675, Germany and Physik-Department, Technische Universität München, James-Franck-Str. 1, Garching 85748 (Germany)

    2015-11-15

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  16. Polarization phenomena in heavy ion induced reactions

    International Nuclear Information System (INIS)

    Mechanisms of heavy ion reactions are discussed from the experimental results on polarization of products 12B in 14N + 100Mo and 14N + 232Th reactions. Polarization determines the signs of deflection functions corresponding to large energy losses. (author)

  17. Ion irradiation-induced structure damage to botanic samples using the ion transmission energy spectrum

    International Nuclear Information System (INIS)

    In order to study the mechanism of irradiation-induced damage of botanic samples caused by low energy heavy ions, transmission energy spectrum measurement was performed. Kidney bean slice samples 100 μm in thickness were irradiated by 50 keV N+ ions. The irradiation beam current density was about 30 μA/cm2, and the irradiation ion doses were 1 x 1015, 1 x 1016, 3 x 1016 and 1 x 1017 ions·cm-2, respectively. A target set up that could greatly reduce the incident ion current density was designed to achieve the damage-free measurement. The 3.2 MeV H+ transmitted ion energy spectrum measurement was carried out before and after the irradiation. From the transmission ion energy spectrum, it was found that the kidney bean slice itself was structurally inhomogeneous compared with the PET films (C10H8O4). The results indicated that the average mass thickness changed little when the N+ ion dose was below 3 x 1016 ions·cm-2, but changed obviously when ion dose was beyond 3 x 1016 ions·cm-2

  18. Mapping ion beam induced current changes in a commercial MOSFET

    Energy Technology Data Exchange (ETDEWEB)

    Alves, A.D.C.; Thompson, S.; Yang, C. [School of Physics, University of Melbourne, Victoria 3010 (Australia); Jamieson, D.N., E-mail: d.jamieson@unimelb.edu.au [School of Physics, University of Melbourne, Victoria 3010 (Australia)

    2011-10-15

    We demonstrate a novel nuclear microprobe imaging and analysis modality for micrometre-scale field effect transistor devices probed with focused beams of MeV ions. By recording the drain current as a function of time during ion irradiation it is possible to identify current transients induced by the passage of single ions through the sensitive structures of the device. This modality takes advantage of the fact that the ionization produced by the passage of a single ion acts in an equivalent way to a transient change in the gate bias which therefore modulates the drain current as a function of time. This differs from the traditional ion beam induced charge technique where the ionization drifts in an internal electric field and induces a single charge pulse in an electrode applied to the device. Instead a richer variety of phenomena are observed, with different time constants which depend on the proximity of the ion strike to the channel of the device. The signals may be used to examine device function, radiation sensitivity or to count ion impacts within the channel.

  19. Fabrication and Optimization of Carbon Nanomaterial-Based Lithium-Ion Battery Anodes

    OpenAIRE

    Somnhot, Parina

    2012-01-01

    Lithium-ion batteries possess high energy and power densities, making them ideal candidates for energy storage requirements in various military applications. Commercially produced lithium-ion battery anodes are commonly graphitic carbon-based. However, graphitic carbons are limited in surface area and possess slow intercalation kinetics. The energy and power density demands of future technologies require improved lithium-ion battery performance. Carbon nanomaterials, such as carbide-derived c...

  20. Metal carbonates as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Lianyi; Ma, Rui; Wu, Kaiqiang; Shui, Miao; Lao, Mengmeng; Wang, Dongjie; Long, Nengbing; Ren, Yuanlong; Shu, Jie, E-mail: sergio_shu@hotmail.com

    2013-12-25

    Highlights: •Metal carbonates are probable anode materials for lithium ion batteries. •CoCO{sub 3}/C composite can deliver an initial discharge capacity of 2096.6 mAh g{sup −1} . •Co, Li{sub 2}CO{sub 3}, Li{sub 2}O, and low-valence carbon are final lithiated products for CoCO{sub 3}. -- Abstract: Six metal carbonates (Li{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, SrCO{sub 3}, BaCO{sub 3}, K{sub 2}CO{sub 3}, CoCO{sub 3}) are tested and compared as anode materials for lithium ion batteries. The electrochemical results show that only CoCO{sub 3} is electrochemically active material and can deliver a high initial capacity of 1425.9 mAh g{sup −1}. The lithium storage mechanism in CoCO{sub 3} is studied by ex situ X-ray diffraction technique, ex situ infrared method, ex situ X-ray photoelectron spectroscopy and in situ X-ray diffraction technique. It is found that the electrochemical reactions between CoCO{sub 3} and Li firstly result in the formation of metal Co and Li{sub 2}CO{sub 3}, and then partial Li{sub 2}CO{sub 3} is further reduced into carbon (C{sup 0}), low-valence carbon (C{sup 2+}), and Li{sub 2}O. It also demonstrates that the electrochemical reaction between CoCO{sub 3} and Li is a partially reversible process. Based on these electrochemical results, it is obvious that narrow potential range can acquire a better reversibility for CoCO{sub 3}/Li batteries by suppressing particle pulverization. Besides, the comparison of CoCO{sub 3}, ball-milled CoCO{sub 3} and ball-milled CoCO{sub 3}/C composite also indicates that smaller active particle and carbon buffer are beneficial to obtain better cycling performance and higher reversible capacity.

  1. Contribution of nitric oxide radicals in bystander and adaptive responses induced by heavy ion-beams

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate whether radioadaptive responses were induced after irradiation with accelerated ion beams through nitric oxide-mediated bystander response in cultured cells in vitro and in some organs of mice in vivo. Human non-small cell lung carcinoma cells transfected with wild-type p53 (H1299/wtp53 cells) were used. The cells were irradiated with accelerated carbon ion beams (290 MeV/u, 31 keV/μm or 135 MeV/u, 31 keV/μm). Then, the cells were allowed forming colonies. ICR male mice (Jcl: ICR) were used. The mice were irradiated on 2 days with accelerated carbon ion beams (290 MeV/u, 13 keV/μm or 135 MeV/u, 25 keV/μm) or argon ion beams (500 MeV/u, 90 keV/μm). The small intestine and testis were excised 2 days after the last irradiation. These excised tissues were fixed, embedded in paraffin and made of thin-sections on slide glasses. Then the TUNEL- and activated caspase-3-positive cells in the thin-sections of tissues were detected by the immunohistochemical method. A significant elevated surviving fractions of cells was observed when the cells were challengingly irradiated after the priming irradiation with accelerate carbon ion beams. This enhancement was partially suppressed by Nitric oxide (NO) radical scavenger, carboxy-PTIO (c-PTIO). The bystander-induced apoptotic and activated caspase-3-positive cells were obviously observed in the unirradiated small intestine and testis when mice were irradiated with carbon or argon ion beams across the upper body. In addition, a significant reduction of apoptotic cells in the intestine and testis, when mice were challengingly irradiated after the priming irradiation with accelerate carbon or argon ion beams. These observations were partially suppressed by c-PTIO into the peritoneal cavity. Furthermore, it is suggested that the apoptosis may be induced in the tissue stem cells of small intestine and testis. (author)

  2. Complexation of europium(III) with carbonate ions in groundwater

    International Nuclear Information System (INIS)

    The equilibrium extraction behavior of Eu(III) studied in chloroform solutions containing 1-nitroso-2-naphthol (HA), either alone or combined with 2,2'-dipyridyl, 1,10-phenanthroline (phen), or trioctylphosphine oxide (TOPO) shows that the metal ion is extracted as either EuA3, EuA3.2,2'-dipyridyl, EuA3.phen, or EuA32TOPO, respectively. The synergic effect of phen or TOPO on the extraction of EU(III) with 1-nitrose-2-naphthol is more pronounced over that of 2,2'-dipyridyl. The carbonate complexation of EU(III) has been studied in 1.0 M ionic strength solutions at pH 8.0-9.0 and 250C using the synergic extraction system of 1-nitroso-2-naphthol and phen. The following complexes have been identified: EuCo+3, Eu(CO3)-2, Eu(CO3)3-3, and Eu(CO3)5-4; the results suggest that the first two species predominate at carbonate concentrations and pH similar to those found in most groundwaters. The formation constants of these species have been calculated at zero ionic strength using both SIT and ion pairing models

  3. Irradiation with carbon ions for locally recurrent rectal cancer

    International Nuclear Information System (INIS)

    A female patient in her 70s underwent an abdominoperineal resection and bilateral lymph node dissection for advanced lower rectal cancer. The patient did not receive neoadjuvant therapy. In the Japanese classification of colorectal carcinoma (8th Edition), the tumor was a moderately differentiated type 2 adenocarcinoma, and was 4.5 cm in size. Histologically, the tumor was considered to be Stage 3b (T3N0M0). She received no adjuvant chemotherapy. After 39 months, pelvic computed tomography (CT) revealed a 29 mm tumor in the right pelvic wall. The patient declined surgery for recurrence so radiotherapy was planned. First, chemotherapy with mFOLFOX6 was administered for 4 courses to reduce tumor size. Consequently, irradiation with carbon ions was given to the site of recurrence at a total dose of 74 GyE in 37 fractions. There were no severe complications. Carcinoembryonic antigen (CEA) level decreased to the lower limit of the normal range from a maximum of 4.9, and no progression of the recurrent tumor was detected on CT for approximately 4 years. Systemic chemotherapy followed by irradiation with carbon ions may be effective for recurrent rectal cancer. (author)

  4. Electron emission and molecular fragmentation during hydrogen and deuterium ion impact on carbon surfaces

    Science.gov (United States)

    Qayyum, A.; Schustereder, W.; Mair, C.; Scheier, P.; Märk, T. D.; Cernusca, S.; Winter, HP.; Aumayr, F.

    2003-03-01

    Molecular fragmentation and electron emission during hydrogen ion impact on graphite surfaces has been investigated in the eV to keV impact energy region typical for fusion edge plasma conditions. As a target surface graphite tiles for the Tokamak experiment Tore Supra in CEA-Cadarache/France and highly oriented pyrolytic graphite (HOPG) have been used. For both surfaces studied, the experimentally observed threshold for electron emission is at about 50 eV/amu impact energy. Electron emission from the high conductivity side of the carbon tile is 15-20% less as compared to its low conductivity side, whereas results for HOPG are generally between these two cases. Deuterium and hydrogen ions are almost equally effective in liberating electrons from graphite when comparing results for the same impact velocity. Surface-induced dissociation of deuterium ions D 3+ upon impact on Tore Supra graphite tiles, in the collision energy range of 20-100 eV, produced only atomic fragment ions D +. The other possible fragment ion D 2+ could not be observed.

  5. Electron emission and molecular fragmentation during hydrogen and deuterium ion impact on carbon surfaces

    International Nuclear Information System (INIS)

    Molecular fragmentation and electron emission during hydrogen ion impact on graphite surfaces has been investigated in the eV to keV impact energy region typical for fusion edge plasma conditions. As a target surface graphite tiles for the Tokamak experiment Tore Supra in CEA-Cadarache/France and highly oriented pyrolytic graphite (HOPG) have been used. For both surfaces studied, the experimentally observed threshold for electron emission is at about 50 eV/amu impact energy. Electron emission from the high conductivity side of the carbon tile is 15-20% less as compared to its low conductivity side, whereas results for HOPG are generally between these two cases. Deuterium and hydrogen ions are almost equally effective in liberating electrons from graphite when comparing results for the same impact velocity. Surface-induced dissociation of deuterium ions D3+ upon impact on Tore Supra graphite tiles, in the collision energy range of 20-100 eV, produced only atomic fragment ions D+. The other possible fragment ion D2+ could not be observed

  6. Immobilization of extracellular matrix on polymeric materials by carbon-negative-ion implantation

    Science.gov (United States)

    Tsuji, Hiroshi; Sommani, Piyanuch; Muto, Takashi; Utagawa, Yoshiyuki; Sakai, Shun; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

    2005-08-01

    Effects of ion implantation into polystyrene (PS), silicone rubber (SR) and poly-L-lactic acid (PLA) have been investigated for immobilization of extracellular matrix. Carbon negative ions were implanted into PS and SR sheets at various energies between 5-30 keV and various doses between 1.0 × 1014-1.0 × 1016 ions/cm2. Contact angles of pure water on C-implanted surfaces of PS and SR were decreased as increase in ion energy and in dose due to formation of functional groups such as OH and C-O. Selective attachment of nerve cells was observed on C-implanted them at 10 keV and 3 × 1015 ions/cm2 after in vitro cell culture of nerve cells of PC-12 h. Neurite outgrowth also extended over the implanted area. After dipping in a serum medium and in a fibronectin solution for 2 h, the detection of N 1s electrons by X-ray induced photoelectron spectroscopic (XPS) revealed a significant distinction of protein adhesion on the implanted area. Thus, immobilization of proteins on surface is used for considering the selective cell-attachment. For PLA, the selective attachment of cells and protein depended on the implantation conditions.

  7. Mass spectrometry of refractory black carbon particles from six sources: carbon-cluster and oxygenated ions

    Directory of Open Access Journals (Sweden)

    J. C. Corbin

    2013-10-01

    Full Text Available We discuss the major mass spectral features of different types of refractory carbonaceous particles, ionized after laser vapourization with an Aerodyne High-Resolution Soot-Particle Aerosol Mass Spectrometer (SP-AMS. The SP-AMS was operated with a switchable 1064 nm laser and a 600 °C thermal vapourizer, yielding respective measurements of the refractory and non-refractory particle components. Six samples were investigated, all of which were composed primarily of refractory material: fuel-rich and fuel-lean propane/air diffusion-flame combustion particles; graphite-spark-generated particles; a commercial Fullerene-enriched Soot; Regal Black, a commercial carbon black; and nascent aircraft-turbine combustion particles. All samples exhibited a spectrum of carbon-cluster ions Cxn+ in their refractory mass spectrum. Smaller clusters (xxn+ distribution. For Fullerene Soot, fuel-rich-flame particles and spark-generated particles, significant Cxn+ clusters at x≫6 were present, with significant contributions from multiply-charged ions (n>1. In all six cases, the ions C1+ and C3+ contributed over 60% to the total C1x+ intensity. Furthermore, the ratio of these major ions C1+/C3+ could be used to predict whether significant Cxn+ signals with x>5 were present. When such signals were present, C1+/C3+ was close to 1. When absent, C1+/C3+ was Significant refractory oxygenated ions such as CO+ and CO2+ were also observed for all samples. We discuss these signals in detail for Regal Black, and describe their formation via decomposition of oxygenated moieties incorporated into the refractory carbon structure. These species may be of importance in atmospheric processes such as water uptake, aging and heterogeneous chemistry.

  8. 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)

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

    International Nuclear Information System (INIS)

    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+ ion implantation effects on PMMA at different fluences ranging from 5 × 1013 to 5 × 1015 ions/cm2. 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 × 1014 to 5 × 1015 ions/cm2. The existence of amorphization and sp2-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) × 10−10 (Ω-cm)−1 (pristine) to (0.32 ± 0.01) × 10−5 (Ω-cm)−1 (irradiated sample)

  10. DBD as a post-discharge bipolar ions source and selective ion-induced nucleation versus ions polarity

    Science.gov (United States)

    Bourgeois, E.; Jidenko, N.; Alonso, M.; Borra, J. P.

    2009-10-01

    Ions densities and mobilities in post-dielectric barrier discharge (post-DBD) are presented here. To extract ions from DBD and perform post-discharge measurements the best functioning conditions are low overpressure, high frequency (>=25 kHz, to avoid electrocollection) and low flow rate (1 lpm, to reduce dilution). Besides, ions densities in post-discharge increase with electrode temperature and, at low flow rates, with the number of discharge filaments by time and surface unit (controlled by voltage at fixed frequency). In both cases, the reinforcement of dielectric material surface polarization reduces the local electrocollection of ions inside DBD or increases the production of ions by subcritical avalanches outside filaments. Concerning mobility measurements, it is shown that for low saturation, vapours emitted from post-DBD polymer tubes only affect positive ions mobility due to selective ion-induced nucleation on positive ions. When metal post-DBD tubes are used, positive ions keep the same range of electric mobility at any temperature while there is a drop in negative ions mobility around 100 °C, probably related to a chemical transition between O3 and NOx.

  11. DBD as a post-discharge bipolar ions source and selective ion-induced nucleation versus ions polarity

    International Nuclear Information System (INIS)

    Ions densities and mobilities in post-dielectric barrier discharge (post-DBD) are presented here. To extract ions from DBD and perform post-discharge measurements the best functioning conditions are low overpressure, high frequency (≥25 kHz, to avoid electrocollection) and low flow rate (1 lpm, to reduce dilution). Besides, ions densities in post-discharge increase with electrode temperature and, at low flow rates, with the number of discharge filaments by time and surface unit (controlled by voltage at fixed frequency). In both cases, the reinforcement of dielectric material surface polarization reduces the local electrocollection of ions inside DBD or increases the production of ions by subcritical avalanches outside filaments. Concerning mobility measurements, it is shown that for low saturation, vapours emitted from post-DBD polymer tubes only affect positive ions mobility due to selective ion-induced nucleation on positive ions. When metal post-DBD tubes are used, positive ions keep the same range of electric mobility at any temperature while there is a drop in negative ions mobility around 100 0C, probably related to a chemical transition between O3 and NOx.

  12. Nanodosimetric descriptors of the radiation quality of carbon ions

    International Nuclear Information System (INIS)

    In view of the emerging interest of carbon ions in radiotherapy and of the strong correlation between the track structure and the radiobiological effectiveness of ionising radiations, the track-structure properties of 12C-ions were studied at particle energies close to the Bragg peak. To perform the investigations, ionisation-cluster-size distributions for nanometre-sized target volumes were measured with the track-nano-dosimeter installed at the TANDEM-ALPI accelerator complex at LNL, and calculated using a dedicated Monte Carlo simulation code. The resulting cluster-size distributions are used to derive particular descriptors of particle track structure. Here, the main emphasis is laid on the mean ionisation-cluster size M1 and the cumulative probability Fk of measuring cluster sizes ν≥k. From the radiobiological point of view, Fk is of particular interest because an increasing k corresponds to an increase of damages of higher complexity. In addition, Fk saturates with increasing radiation quality like radiobiological cross sections as a function of linear energy transfer. Results will be presented and discussed for 12C-ions at 96 and 240 MeV. (authors)

  13. Exploration of using CT values for treatment planning system to calculate the carbon ion incident energy

    International Nuclear Information System (INIS)

    Objective: To explore the methods of using CT value for Carbon ion treatment planning system to calculate the Carbon ion incident energy. Methods: Bethe-Block formula and the formula for calculating the Car- bon ion range were analyzed to study the relationship of the range of Carbon ion beam (Single nuclear energy 80 MeV -50 MeV) in a variety of radiation equivalent material and the range of this energy Carbon ion beam in water. Procedure of Monte Carlo SRIM 2008 was used to verify the possibility of a constant range of proportional coefficient (Ci). The range of proportional coefficient (Ci) of radiation equivalent material and the CT value were fitted through Origin 8.0 software to study the of CT value and the range of proportional coefficient (Ci). The actual range of Carbon ion is equivalent to a range of water to incident Carbon ion energy. Results: There is a constant range of proportional coefficient (Ci) of the range of Carbon ion beam (Single nuclear energy 80 MeV ∼50 MeV) in a variety of radiation equivalent material and the range of this energy Carbon ion beam in water. There is a of CT value and the range of proportional coefficient (Ci) (r=0.999). The actual range of Carbon ion in radiation equivalent material can be equivalent to a range of the water. Conclusion: In this study, using CT values and a range of proportional coefficient (Ci), the actual required range of the tumor can accurately calculate the water equivalent range, and incident Carbon ion energy to the of Bragg peak. By the study, a new exploration for using CT technology, for Carbon ion treatment planning system was obtained. (authors)

  14. Ion implantation induced blistering of rutile single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Bing-Xi [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Jiao, Yang [College of Physics and Electronics, Shandong Normal University, Jinan, Shandong 250100 (China); Guan, Jing [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Wang, Lei [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China)

    2015-07-01

    The rutile single crystals were implanted by 200 keV He{sup +} ions with a series fluence and annealed at different temperatures to investigate the blistering behavior. The Rutherford backscattering spectrometry, optical microscope and X-ray diffraction were employed to characterize the implantation induced lattice damage and blistering. It was found that the blistering on rutile surface region can be realized by He{sup +} ion implantation with appropriate fluence and the following thermal annealing.

  15. Ion implantation induced blistering of rutile single crystals

    Science.gov (United States)

    Xiang, Bing-Xi; Jiao, Yang; Guan, Jing; Wang, Lei

    2015-07-01

    The rutile single crystals were implanted by 200 keV He+ ions with a series fluence and annealed at different temperatures to investigate the blistering behavior. The Rutherford backscattering spectrometry, optical microscope and X-ray diffraction were employed to characterize the implantation induced lattice damage and blistering. It was found that the blistering on rutile surface region can be realized by He+ ion implantation with appropriate fluence and the following thermal annealing.

  16. Light-induced charging effects in microscopic ion traps

    International Nuclear Information System (INIS)

    Full text: Microfabricated ion traps are discussed as one of the most promising candidates for a quantum mechanical computer. By bringing the electrodes close to the ions a rich selection of trapping potentials can be created and many traps can, in principle, be operated in parallel. However, the proximity of the electrodes and other surfaces poses strong constraints on the materials used. In particular, near-by glass surfaces that may be used for high-finesse cavities around the ions or for light collection represent a challenge, since the dielectric surfaces may charge up and perturb the trapping potential. By bringing a glass substrate close to a surface ion trap, the charging can be studied in a controlled manner. Two distinct mechanisms of charging have been observed, both being light-induced with different wavelength dependence. The results allow an estimate of the rate of charge production and may be prove useful for the design of new integrated microscopic ion traps. (author)

  17. Carbon matrix/SiNWs heterogeneous block as improved reversible anodes material for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    Yao; Wang; Long; Ren; Yundan; Liu; Xuejun; Liu; Kai; Huang; Xiaolin; Wei; Jun; Li; Xiang; Qi; Jianxin; Zhong

    2014-01-01

    A novel carbon matrix/silicon nanowires(SiNWs) heterogeneous block was successfully produced by dispersing SiNWs into templated carbon matrix via a modified evaporation induced self-assembly method. The heterogeneous block was determined by X-ray diffraction, Raman spectra and scanning electron microscopy. As an anode material for lithium batteries, the block was investigated by cyclic voltammograms(CV), charge/discharge tests, galvanostatic cycling performance and A. C. impedance spectroscopy. We show that the SiNWs disperse into the framework, and are nicely wrapped by the carbon matrix. The heterogeneous block exhibits superior electrochemical reversibility with a high specific capacity of 529.3 mAh/g in comparison with bare SiNWs anode with merely about 52.6 mAh/g capacity retention. The block presents excellent cycle stability and capacity retention which can be attributed to the improvement of conductivity by the existence of carbon matrix and the enhancement of ability to relieve the large volume expansion of SiNWs during the lithium insertion/extraction cycle. The results indicate that the as-prepared carbon matrix/SiNWs heterogeneous block can be an attractive and potential anode material for lithium-ion battery applications.

  18. Ion induced high energy electron emission from copper

    Energy Technology Data Exchange (ETDEWEB)

    Ruano, G. [Instituto de Desarrollo Tecnologico para la Industria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina)], E-mail: gdruano@ceride.gov.ar; Ferron, J. [Instituto de Desarrollo Tecnologico para la Industria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina); Departamento de Ingenieria de Materiales, Facultad de Ingenieria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina)

    2008-11-15

    We present measurements of secondary electron emission from Cu induced by low energy bombardment (1-5 keV) of noble gas (He{sup +}, Ne{sup +} and Ar{sup +}) and Li{sup +} ions. We identify different potential and kinetic mechanisms and find the presence of high energetic secondary electrons for a couple of ion-target combinations. In order to understand the presence of these fast electrons we need to consider the Fermi shuttle mechanism and the different ion neutralization efficiencies.

  19. Clinical trial of carbon ion radiotherapy for gynecological melanoma

    International Nuclear Information System (INIS)

    Carbon ion radiotherapy (C-ion RT) is an advanced modality for treating malignant melanoma. After we treated our first case of gynecological melanoma using C-ion RT in November 2004, we decided to conduct a clinical trial to evaluate its usefulness for the treatment of gynecological melanoma. The eligibility criteria for enrollment in this study were histologically proven malignant melanoma of the gynecological regions with lymph node metastasis remaining in the inguinal and pelvic regions. The small pelvic space, including the GTV and the metastatic lymph node, was irradiated with up to a total dose of 36 GyE followed by a GTV boost of up to a total dose of 57.6 GyE or 64 GyE in 16 fractions. A series of 23 patients were treated between November 2004 and October 2012. Patient age ranged from 51-80 with a median of 71. Of the tumor sites, 14 were located in the vagina, 6 in the vulva, and 3 in the cervix uteri. Of the 23 patients, 22 were irradiated with up to a total dose of 57.6 GyE, and 1 patient was irradiated with up to a total dose of 64 GyE. Chemotherapy and interferon-β were also used to treat 11 of the patients. Acute and late toxicities of Grade 3 or higher were observed in 1 patient treated with concurrent interferon-β. The median follow-up time was 17 months (range, 6-53 months). There was recurrence in 14 patients, and the 3-year local control and overall survival rates were 49.9% and 53.0%, respectively. C-ion RT may become a non-invasive treatment option for gynecological melanoma. (author)

  20. L X-ray emission induced by heavy ions

    Science.gov (United States)

    Pajek, M.; Banaś, D.; Braziewicz, J.; Majewska, U.; Semaniak, J.; Fijał-Kirejczyk, I.; Jaskóła, M.; Czarnacki, W.; Korman, A.; Kretschmer, W.; Mukoyama, T.; Trautmann, D.

    2015-11-01

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster-Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L2-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  1. Ion Transport Characteristics of Individual Single-walled Carbon Nanotubes Mimic Those of Biological Ion Channels

    Science.gov (United States)

    Amiri, Hasti; Shepard, Kenneth; Nuckolls, Colin

    2014-03-01

    Transmembrane ionic channels play a crucial role in vital cellular activities by regulating the transport of ions and fluid across the cell membrane. Their structural complexity and flexibility as well as their many unique operational features, however, make their investigation extremely difficult. The simple, atomically smooth and well-defined structure of carbon nanotubes (CNTs) provides an excellent template for studying molecular transport at nanoscale. Additionally, CNTs have been suggested as analogues to biological pores since they share several common features such as nanometer size diameter, hydrophobic core and ultrafast water flow. Functionalizing the nanotube entrance can also mimic the selectivity filter of ion channels. In this work, we experimentally study ionic transport through individual single-walled CNTs connecting two fluid reservoirs as a function of pore properties and electrolyte type and concentration. We provide strong evidence that the electrostatic potentials arising from the ionized carboxyl groups at the pore entrance significantly influence the ion permeation in a manner consistent with a simple electrostatic mechanism. Lastly, the similarities of ionic transport mechanisms between individual single-walled CNTs and protein ion channels are discussed.

  2. Optical properties of ion-beam-deposited ion-modified diamondlike (a-C:H) carbon

    International Nuclear Information System (INIS)

    Diamondlike carbon (DLC) is a hard, semitransparent material usually containing varying amounts of hydrogen. These materials have numerous potential applications, including use as coatings for infrared optics, and as such, the effects of damaging irradiation is of practical interest. In this paper we present results of variable angle spectroscopic ellipsometric (VASE) studies of ion-beam-deposited DLC films. These films have been further modified by directing 1-MeV gold ions, as well as 6.4-MeV fluorine ions, through the DLC and into the underlying silicon substrates, and the percentage of hydrogen in the film was measured versus fluence using proton recoil analysis. Optical analysis was performed assuming the Lorentz oscillator model. Three versions were used: one oscillator, two oscillator (with one fixed in energy), and two oscillator with all parameter variable. The latter model fits the VASE data extremely well, and the two oscillators can be interpreted as involving π to π* and σ to σ* band transitions. With ion modification the oscillators shift to lower photon energy, consistent with reduction in hydrogen concentration and possible increased graphitization

  3. Microbially induced corrosion of carbon steel in deep groundwater environment

    OpenAIRE

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing abil...

  4. Clinical Outcome of Sacral Chordoma With Carbon Ion Radiotherapy Compared With Surgery

    International Nuclear Information System (INIS)

    Purpose: To evaluate the efficacy, post-treatment function, toxicity, and complications of carbon ion radiotherapy (RT) for sacral chordoma compared with surgery. Methods and Materials: The records of 17 primary sacral chordoma patients treated since 1990 with surgery (n = 10) or carbon ion RT (n = 7) were retrospectively analyzed for disease-specific survival, local recurrence-free survival, complications, and functional outcome. The applied carbon ion dose ranged from 54.0 Gray equivalent (GyE) to 73.6 GyE (median 70.4). Results: The mean age at treatment was 55 years for the surgery group and 65 years for the carbon ion RT group. The median duration of follow-up was 76 months for the surgery group and 49 months for the carbon ion RT group. The local recurrence-free survival rate at 5 years was 62.5% for the surgery and 100% for the carbon ion RT group, and the disease-specific survival rate at 5 years was 85.7% and 53.3%, respectively. Urinary-anorectal function worsened in 6 patients (60%) in the surgery group, but it was unchanged in all the patients who had undergone carbon ion RT. Postoperative wound complications requiring reoperation occurred in 3 patients (30%) after surgery and in 1 patient (14%) after carbon ion RT. The functional outcome evaluated using the Musculoskeletal Tumor Society scoring system revealed 55% in the surgery group and 75% in the carbon ion RT group. Of the six factors in this scoring system, the carbon ion RT group had significantly greater scores in emotional acceptance than did the surgery group. Conclusion: Carbon ion RT results in a high local control rate and preservation of urinary-anorectal function compared with surgery.

  5. Effects of carbon ion beam irradiation on the shoot regeneration from in vitro axillary bud explants of the Impatiens hawkeri

    Science.gov (United States)

    Zhou, Libin; Zhou, Libin; Li, Wenjian; Li, Ping; Dong, Xicun; Qu, Ying; Ma, Shuang; Li, Qiang

    Accelerated ion beams is an excellent mutagen in plant breeding which can induce higher mutation frequencies and wider mutation spectrum than those of low linear energy transfer (LET) irradiations, such as X-rays (Okamura et al. 2003, Yamaguchi et al. 2003). Mutation breeding operation of two Saintpaulia ionahta cultivars using the method combining plant tissue culture technique and carbon ion beam irradiations were set out at Institute of Modern Physics from 2005 (Zhou et al. 2006). The effects of 960 MeV carbon ion beam and 8 MeV X-ray irradiations on regenerated shoots of Impatiens hawkeri from another kind of explants named in vitro axillary buds explants were studied recently. The biology endpoints in this study included relative number of roots (RNR), relative length of roots (RLR), relative height of shoots (RHS), relative number of nodes (RNN), survival fraction (SF) and morphology changes in the regenerated shoots. The experimental results showed that carbon ion beams inhibited the root and stem developments of axillary bud explants more severely than X-rays did. And the 50% lethal dose (LD50 ) is about 23.3 Gy for the carbon ion beam and 49.1 Gy for the X-rays, respectively. Relative biological effectiveness (RBE) of Impatiens hawkeri with respect to X-rays according to 50% SF was about two. Secondly, the percentage of shoots regenerated with malformed shoots including curliness, carnification, nicks in all Impatiens hawkeri axillary bud explants irradiated with carbon ion beam at 20 Gy accounted for 55.6%, while the highest number for the 40 Gy X-ray irradiation was 40%. Last, many regenerated shoots whose vascular bundle fused together were obtained only from explants irradiated with carbon ion beams. Based on the results above, it can be concluded that the effect of mutation induction by carbon ion beam irradiation on the axillary explants of Impatiens hawkeri is better than that by X-ray irradiation; and the optimal mutagenic dose varies from 20 Gy

  6. Peapod-like composite with nickel phosphide nanoparticles encapsulated in carbon fibers as enhanced anode for li-ion batteries.

    Science.gov (United States)

    Zhang, Huijuan; Feng, Yangyang; Zhang, Yan; Fang, Ling; Li, Wenxiang; Liu, Qing; Wu, Kai; Wang, Yu

    2014-07-01

    Herein, we introduce a peapod-like composite with Ni12 P5 nanoparticles encapsulated in carbon fibers as the enhanced anode in Li-ion batteries for the first time. In the synthesis, NiNH4 PO4 ⋅H2 O nanorods act as precursors and sacrificial templates, and glucose molecules serve as the green carbon source. With the aid of hydrogen bonding between the precursor and carbon source, a polymer layer is hydrothermally formed and then rationally converted into carbon fibers upon inert calcination at elevated temperatures. Meanwhile, NiNH4 PO4 ⋅H2 O nanorods simultaneously turn into Ni12 P5 nanoparticles encapsulated in carbon fibers by undergoing a decomposition and reduction process induced by high temperature and the carbon fibers. The obtained composite performs excellently as a Li-ion batteries anode relative to pure-phase materials. Specific capacity can reach 600 m Ah g(-1) over 200 cycles, which is much higher than that of isolated graphitized carbon or phosphides, and reasonably believed to originate from the synergistic effect based on the combination of Ni12 P5 nanoparticles and carbon fibers. Due to the benignity, sustainability, low cost, and abundance of raw materials of the peapod-like composite, numerous potential applications, in fields such as optoelectronics, electronics, specific catalysis, gas sensing, and biotechnology can be envisaged. PMID:24648293

  7. The co-effect of collagen and magnesium ions on calcium carbonate biomineralization

    International Nuclear Information System (INIS)

    The process of calcium carbonate biomineralization in the solution containing collagen and magnesium ions was studied in this paper. The results were characterized by using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect rules were obtained by the cooperation of collagen and magnesium ions in different concentration. The experiment results showed that in the presence of both collagen and magnesium ions, aragonite and vaterite were precipitated at low Mg/Ca ion concentration ratio, while only aragonite with regular spherical morphology was precipitated at high Mg/Ca ion concentration ratio. It indicated that collagen has a promotional effect on magnesium ions in controlling the polymorph of calcium carbonate crystal. A much wider range of calcium carbonate morphologies was observed in the presence of both collagen and magnesium ions. The experiments suggested that collagen acts in combination with magnesium ions to inhibit calcite crystal growth, while favoring the formation of aragonite crystals

  8. Characteristics of Ion Activation and Collision Induced Dissociation Using Digital Ion Trap Technology

    Science.gov (United States)

    Xu, Fuxing; Dang, Qiankun; Dai, Xinhua; Fang, Xiang; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2016-05-01

    Collision induced dissociation (CID) is one of the most established techniques for tandem mass spectrometry analysis. The CID of mass selected ion could be realized by ion resonance excitation with a digital rectangular waveform. The method is simple, and highly efficient CID result could be obtained by optimizing the experimental parameters, such as digital waveform voltage, frequency, and q value. In this work, the relationship between ion trapping waveform voltage and frequency at preselected q value, the relationship between waveform frequency and the q value at certain ion trapping voltage for optimum CID efficiency were investigated. Experiment results showed that the max CID efficiency of precursor reserpine ions can be obtained at different trapping waveform voltage and frequency when q and β are different. Based on systematic experimental analysis, the optimum experimental conditions for high CID efficiency can be calculated at any selected β or q. By using digital ion trap technology, the CID process and efficient fragmentation of parent ions can be realized by simply changing the trapping waveform amplitude, frequency, and the β values in the digital ion trap mass spectrometry. The technology and method are simple. It has potential use in ion trap mass spectrometry.

  9. Ion irradiation-induced structure damage to botanic samples using the ion transmission energy spectrum

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness were irradi-ated by 50 kev N+ ions. The irradiation beam current density was about 30μA/cm2,and the irradiation ion doses were 1×1015, 1×1016, 3×1016 and 1×1017 ions@cm-2,respectively. A target set up that could greatly reduce the incident ion current densitywas designed to achieve the damage-free measurement. The 3.2 MeV H+ transmittedion energy spectrum measurement was carried out before and after the irradiation.From the transmission ion energy spectrum, it was found that the kidney bean sliceitself was structurally inhomogeneous compared with the PET films (C10HsO4). Ourresults indicated that the average mass thickness changed little when the N+ iondose was below 3×1016 ions.cm-2, but changed obviously whcn ion dose was beyond3×1016 ions.cm-2.

  10. Advanced ion beam analysis of materials using ion-induced fast electron

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Hiroshi; Tanabe, Atsushi; Ishihara, Toyoyuki [Tsukuba Univ., Ibaraki (Japan)] [and others

    1997-03-01

    Recent progress in the study of high-energy shadowing effect using ion-induced electron spectroscopy is reported with emphasis on a possibility of determination of local electronic structure in solids, which has been a difficult problem to approach with other experimental techniques. We demonstrate real-space determination of covalent-bond electron distribution in Si crystal. The analysis technique may provide a new field of ion beam analysis of solids. (author)

  11. Neutralized ion beam modification of cellulose membranes for study of ion charge effect on ion-beam-induced DNA transfer

    Energy Technology Data Exchange (ETDEWEB)

    Prakrajang, K., E-mail: k.prakrajang@gmail.com [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sangwijit, K.; Anuntalabhochai, S. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wanichapichart, P. [Membrane Science and Technology Research Center, Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkla 90110 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (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)

    2012-02-01

    Low-energy ion beam biotechnology (IBBT) has recently been rapidly developed worldwide. Ion-beam-induced DNA transfer is one of the important applications of IBBT. However, mechanisms involved in this application are not yet well understood. In this study plasma-neutralized ion beam was applied to investigate ion charge effect on induction of DNA transfer. Argon ion beam at 7.5 keV was neutralized by RF-driven plasma in the beam path and then bombarded cellulose membranes which were used as the mimetic plant cell envelope. Electrical properties such as impedance and capacitance of the membranes were measured after the bombardment. An in vitro experiment on plasmid DNA transfer through the cellulose membrane was followed up. The results showed that the ion charge input played an important role in the impedance and capacitance changes which would affect DNA transfer. Generally speaking, neutral particle beam bombardment of biologic cells was more effective in inducing DNA transfer than charged ion beam bombardment.

  12. Stationary plume induced by carbon dioxide dissolution

    International Nuclear Information System (INIS)

    In this paper, laminar convection flows induced by carbon dioxide absorption are addressed from experimental, numerical and theoretical points of view. A vertical glass tube (of centimetre scale) filled with distilled water is subjected to a sudden increase in the partial pressure of carbon dioxide. As a result of the diffusion of the gas into the unsaturated solution, a thin layer of fluid located underneath the surface becomes heavier. This initial density gradient first destabilizes to form a plume, which goes downwards through the entire cell. After a first transient pulsating regime (periodic succession of such Rayleigh-Benard plumes), a stationary flow settles in the tube, which is maintained by the constant supply of gas at the surface. At late stages, this stationary regime is followed by an aperiodic regime, which lasts until the complete saturation of the solution (thermodynamic equilibrium). The present study only focuses on the stationary regime, whose characteristics appear to be almost independent of the Bond number and the aspect ratio but strongly dependent on the chemical Rayleigh number. Three decades of Rayleigh numbers are explored using particle image velocimetry measurements, which allows for a precise determination of the scaling exponents for the vertical velocity amplitude and the plume width. The assumption that gravity and a constant pressure gradient balance the viscous effects enables us to derive an analytic expression for the stationary vertical velocity on the axis, which scales as Ra2/3 (ln Ra)1/3. As a consequence, the width of the plume scales as Ra-1/6 (ln Ra)-1/3 and the mass Nusselt number as (Ra= ln Ra)1/3. These scalings are in excellent agreement with the experimental and numerical results. The multiplicative constants of these scalings can also be calculated and show a fairly good agreement if a rigid boundary condition (no-slip) is assumed at the free surface. (authors)

  13. Data compilation for depth distribution of ion-induced damage and ion-implanted atoms

    International Nuclear Information System (INIS)

    In the recent progress of utilizing ion bombardment technique to ion implantation and neutron irradiation simulation, the experimental data have accumulated concerning the depth distribution of deposited atoms and induced damage along ion incident direction. In the ion-induced damage experiments, the density of point defects or void swelling has been investigated as a function of depth. In this study, the data available until the present time are compiled and compared with theoretical prediction represented by E-DEP-1 computer code. It is recognized in general that the experimentally observed damage peak is deeper than that E-DEP-1 calculated using the LSS electronic stopping parameter, k sub(LSS). Agreement between the observation and calculation can be obtained using a modified electronic stopping parameter k = 0.8 - 0.9 k sub(LSS). With regard to the deposited atoms by ion bombardment, the peak of the observed distribution is deeper in some cases and shallower in other cases than that calculated by E-DEP-1, indicating that the modified electronic stopping parameter k is oscillating relative to k sub(LSS). This oscillatory behavior is not recognized in the damage distribution. It is suggested that future work should be made to determine the distribution of ion-induced damage in relation to that of the deposited atoms, since the defect evolution may directly be related to the implanted atoms. (author)

  14. Assessment of DNA damage of Lewis lung carcinoma cells irradiated by carbon ions and X-rays using alkaline comet assay

    International Nuclear Information System (INIS)

    DNA damage and cell reproductive death determined by alkaline comet and clonogenic survival assays were examined in Lewis lung carcinoma cells after exposure to 89.63 MeV/u carbon ion and 6 MV X-ray irradiations, respectively. Based on the survival data, Lewis lung carcinoma cells were verified to be more radiosensitive to the carbon ion beam than to the X-ray irradiation. The relative biological effectiveness (RBE) value, which was up to 1.77 at 10% survival level, showed that the DNA damage induced by the high-LET carbon ion beam was more remarkable than that induced by the low-LET X-ray irradiation. The dose response curves of 'Tail DNA (%)' (TD) and 'Olive tail moment' (OTM) for the carbon ion irradiation showed saturation beyond about 8 Gy. This behavior was not found in the X-ray curves. Additionally, the carbon ion beam produced a lower survival fraction at 2 Gy (SF2) value and a higher initial Olive tail moment 2 Gy (OTM2) than those for the X-ray irradiation. These results suggest that carbon ion beams having high-LET values produced more severe cell reproductive death and DNA damage in Lewis lung carcinoma cells in comparison with X-rays and comet assay might be an effective predictive test even combining with clonogenic assay to assess cellular radiosensitivity

  15. Assessment of DNA damage of Lewis lung carcinoma cells irradiated by carbon ions and X-rays using alkaline comet assay

    Science.gov (United States)

    Li, Ping; Zhou, Li-Bin; Jin, Xiao-Dong; He, Jing; Dai, Zhong-Ying; Zhou, Guang-Ming; Gao, Qing-Xiang; Li, Sha; Li, Qiang

    2008-01-01

    DNA damage and cell reproductive death determined by alkaline comet and clonogenic survival assays were examined in Lewis lung carcinoma cells after exposure to 89.63 MeV/u carbon ion and 6 MV X-ray irradiations, respectively. Based on the survival data, Lewis lung carcinoma cells were verified to be more radiosensitive to the carbon ion beam than to the X-ray irradiation. The relative biological effectiveness (RBE) value, which was up to 1.77 at 10% survival level, showed that the DNA damage induced by the high-LET carbon ion beam was more remarkable than that induced by the low-LET X-ray irradiation. The dose response curves of “Tail DNA (%)” (TD) and “Olive tail moment” (OTM) for the carbon ion irradiation showed saturation beyond about 8 Gy. This behavior was not found in the X-ray curves. Additionally, the carbon ion beam produced a lower survival fraction at 2 Gy (SF2) value and a higher initial Olive tail moment 2 Gy (OTM2) than those for the X-ray irradiation. These results suggest that carbon ion beams having high-LET values produced more severe cell reproductive death and DNA damage in Lewis lung carcinoma cells in comparison with X-rays and comet assay might be an effective predictive test even combining with clonogenic assay to assess cellular radiosensitivity.

  16. Radiation induced effects in carbon materials

    International Nuclear Information System (INIS)

    Full text: The level of safe exploiting nuclear reactor depends on radiation-induced changes of the neutron-absorbing material shape. The dimensional effects in carbon materials including those containing boron carbides B4C, irradiated in the water-water cooled reactor of the INP AS RUz operating at the power of 10 MW were studied in the temperature interval of 300-1500 K up to the integral fluence of 4·1021 neutrons per cm2. Two methods of dimensional control were used: dilatometry (change of linear dimensions and calculation of the volume change) and X-ray diffraction analysis (determination of the lattice parameters and the elementary unit volume). In all samples of low-ash and pyrolytic graphite (oriented parallel and normal to the pressing axis), irradiated up to the fluences above 1021 n/cm2 in the temperature range of 700-1100 K the shrinkage of linear dimensions was found from 6 to 8 %. While there occurred the primary swelling of graphite in the temperature interval of 300-700 K. The secondary swelling began at the fluence of 4·1021 cm-2 and 1100 K. Basing on these data, the neutron-absorbing graphite rods, containing B4C particles, were tested under the analogous irradiation conditions. The comparison of the rates of B4C swelling and graphite matrix shrinkage showed, that unfortunately, there was not gained the complete compensation of the swelling at the expense of shrinkage. The samples of fiber graphite, which were studied under the same conditions as the above mentioned, turned out stable in dimensions - changes in linear dimensions did not exceed 2 %. The X-diffraction study of ultra disperse amorphous carbon film irradiated in the water reactor discovered the formation of a denser carbon phase. The position of the observed structure reflection with d/n = 7.5 A did not correspond to the peaks of stable single phases of fullerenes C60 and C70. Perhaps, the irradiation creates a mixture of these phases in the amorphous matrix

  17. Electron impact excitation of carbon and oxygen ions

    International Nuclear Information System (INIS)

    This report is an attempt at a comprehensive compilation of currently available theoretical data on electron impact excitation of carbon and oxygen ions. It is designed to be of use primarily to theoretical atomic physicists, allowing them a broader than usual view of how various approximations compare. We do not attempt to place an estimate on the accuracy to which any of the collision strengths are known. The reader may obtain some idea of the accuracy from the spread in the calculations. Further, we do not evaluate rate coefficients or make any comparison with observed results. We do provide simple analytic fits to the data, where possible, thus allowing the reader to make comparison with observation or evaluate rate coefficients if he desires. The present data contains little about resonance effects, due to the difficulty of their presentation. It is possible that resonances could make a considerable change in the average collision strength near threshold, and this topic requires further study

  18. The Level and Distribution of Chromosomal Aberration of Tomato Seeds at Different Penetration Depths of Carbon Ions

    Institute of Scientific and Technical Information of China (English)

    WANG Jufang; LI Wenjian; ZHANG Ying

    2008-01-01

    The relationship between the penetration depth and the level and distribution of chromosomal aberration of the root tip cells were investigated by exposure of the superposed tomato seeds to 80 MeV/u carbon ions. The results showed that on the entrance of the beam the chromosomal aberration level was low. Damage such as breaks and gaps were dominant. At the Bragg peak, the chromosomal aberration level was high. The yields of dicentrics, rings and disintegrated small chromosomes increased but the yields of breaks and gaps decreased. These results are consistent with the distribution of the physical depth dose profile of carbon ions. It is effective to deposit the Bragg peak on the seeds to induce hereditary aberration in the mutation breeding with heavy ions.

  19. Study of secondary electron emission from thin carbon targets with swift charged particles: heavy ions, hydrogen ions

    International Nuclear Information System (INIS)

    The main subject of this work is the study of electron emission from the two surfaces of thin solid targets bombarded with swift charged particles. The slowing down of swift ions in matter is mainly due to inelastic interaction with target electrons (ionization, excitation): the energy transfer to target electrons is responsible for the secondary electron emission process. The phenomenological and theoretical descriptions of this phenomena are the subject of the first chapter. We focused on secondary electron emission induced by different kind of projectiles on thin carbon foils. In chapter two we describe hydrogen cluster induced electron emission measurement between 40 and 120 keV/proton. These projectiles, composed of several atoms, allowed us to study and highlight collective effects of the electron emission process. We extended our study of electron emission to molecular (H2+, H3+) and composite (H-, H0) projectiles at higher energies (<= 2 MeV): we have designed an experimental set-up devoted to electron emission statistics measurements which allowed us to study, among others things, the role of projectile electrons in secondary electron emission. This experiment is described in the third chapter. Finally, the fourth chapter describes new measurements of electron emission induced by energetic (13 MeV/u) and highly charged argon ion provided by the medium energy beam line (SME) of GANIL (Caen), which have been analyzed in the framework of a semi-empirical model of secondary electron emission. This set of experiments brings new results on composite projectile interaction with matter, and on the consequences of high energy deposition in solids. (author)

  20. Carbon Ion Therapy for Early-Stage Non-Small-Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Yusuke Demizu

    2014-01-01

    Full Text Available Carbon ion therapy is a type of radiotherapies that can deliver high-dose radiation to a tumor while minimizing the dose delivered to the organs at risk; this profile differs from that of photon radiotherapy. Moreover, carbon ions are classified as high-linear energy transfer radiation and are expected to be effective for even photon-resistant tumors. Recently, high-precision radiotherapy modalities such as stereotactic body radiotherapy (SBRT, proton therapy, and carbon ion therapy have been used for patients with early-stage non-small-cell lung cancer, and the results are promising, as, for carbon ion therapy, local control and overall survival rates at 5 years are 80–90% and 40–50%, respectively. Carbon ion therapy may be theoretically superior to SBRT and proton therapy, but the literature that is currently available does not show a statistically significant difference among these treatments. Carbon ion therapy demonstrates a better dose distribution than both SBRT and proton therapy in most cases of early-stage lung cancer. Therefore, carbon ion therapy may be safer for treating patients with adverse conditions such as large tumors, central tumors, and poor pulmonary function. Furthermore, carbon ion therapy may also be suitable for dose escalation and hypofractionation.

  1. Relative biological effectiveness of carbon ions for causing fatal liver failure after partial hepatectomy in mice

    Energy Technology Data Exchange (ETDEWEB)

    Tomizawa, Minoru; Miyamoto, Tadaaki; Kato, Hirotoshi; Otsu, Hiroshi [National Inst. of Radiological Sciences, Chiba (Japan)

    2000-06-01

    To evaluate the acute phase damage to liver by carbon ions, BALB/c mice were irradiated with carbon ions or X-rays after two-thirds partial hepatectomy, and their survival was followed. The 50% lethal dose within 60 days (LD{sub 50/60}) was 42.2{+-}0.25 Gy (standard error) for X-rays, and 22.7{+-}0.25 Gy for carbon ions. The relative biological effectiveness (RBE) of carbon ions was 1.86 (95% confident limits: 1.69-2.04) as calculated from the LD{sub 50/60}. Mice irradiated at much higher doses, 60 Gy of X-rays or 24 Gy of carbon ions, showed significantly higher serum ammonia levels and lower serum albumin levels than normal, suggesting hepatic failure as a cause of death. Hepatocytes showed karyorrhexis and karyolysis in carbon ion irradiated and spotty necrosis in X-ray irradiated mice, suggesting nuclear damage. Mice irradiated with LD{sub 50} of X-rays or carbon ions had a remarkably lower bromodeoxyuridine (BrdU) labeling index and mitotic index than control. Treatments with both BrdU and vincristine showed that none of the hepatocytes that synthesized DNA after irradiation completed mitosis, indicating G2 arrest. The liver weight of irradiated mice significantly decreased depending on the dose. Carbon ions as well as X-rays damaged hepatocytes directly and suppressed liver regeneration leading to fatal liver failure. (author)

  2. Clinical oxygen enhancement ratio of tumors in carbon ion radiotherapy: the influence of local oxygenation changes

    DEFF Research Database (Denmark)

    Antonovic, Laura; Lindblom, Emely; Dasu, Alexandru;

    2014-01-01

    The effect of carbon ion radiotherapy on hypoxic tumors has recently been questioned because of low linear energy transfer (LET) values in the spread-out Bragg peak (SOBP). The aim of this study was to investigate the role of hypoxia and local oxygenation changes (LOCs) in fractionated carbon ion...

  3. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane

    Directory of Open Access Journals (Sweden)

    A. G. Gaikwad

    2012-06-01

    Full Text Available Transport of carbonate ions was explored through fiber supported solid membrane. A novel fiber supported solid membrane was prepared by chemical modification of cellulose fiber with citric acid, 2′2-bipyridine and magnesium carbonate. The factors affecting the permeability of carbonate ions such as immobilization of citric acid-magnesium metal ion -2′2-bipyridine complex (0 to 2.5 mmol/g range over cellulose fiber, carbon-ate ion concentration in source phase and NaOH concentration in receiving phase were investigated. Ki-netic of carbonate, sulfate, and nitrate ions was investigated through fiber supported solid membrane. Transport of carbonate ions with/without bubbling of CO2 (0 to 10 ml/min in source phase was explored from source to receiving phase. The novel idea is to explore the adsorptive transport of CO2 from source to receiving phase through cellulose fiber containing magnesium metal ion organic framework. Copyright © 2012 BCREC UNDIP. All rights reserved.Received: 25th November 2011; Revised: 17th December 2011; Accepted: 19th December 2011[How to Cite: A.G. Gaikwad. (2012. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1: 49– 57.  doi:10.9767/bcrec.7.1.1225.49-57][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.1225.49-57 ] | View in 

  4. Relative biological effectiveness of carbon ions for causing fatal liver failure after partial hepatectomy in mice

    International Nuclear Information System (INIS)

    To evaluate the acute phase damage to liver by carbon ions, BALB/c mice were irradiated with carbon ions or X-rays after two-thirds partial hepatectomy, and their survival was followed. The 50% lethal dose within 60 days (LD50/60) was 42.2±0.25 Gy (standard error) for X-rays, and 22.7±0.25 Gy for carbon ions. The relative biological effectiveness (RBE) of carbon ions was 1.86 (95% confident limits: 1.69-2.04) as calculated from the LD50/60. Mice irradiated at much higher doses, 60 Gy of X-rays or 24 Gy of carbon ions, showed significantly higher serum ammonia levels and lower serum albumin levels than normal, suggesting hepatic failure as a cause of death. Hepatocytes showed karyorrhexis and karyolysis in carbon ion irradiated and spotty necrosis in X-ray irradiated mice, suggesting nuclear damage. Mice irradiated with LD50 of X-rays or carbon ions had a remarkably lower bromodeoxyuridine (BrdU) labeling index and mitotic index than control. Treatments with both BrdU and vincristine showed that none of the hepatocytes that synthesized DNA after irradiation completed mitosis, indicating G2 arrest. The liver weight of irradiated mice significantly decreased depending on the dose. Carbon ions as well as X-rays damaged hepatocytes directly and suppressed liver regeneration leading to fatal liver failure. (author)

  5. Mass analysis of cesium ion induced fragmentation of C/sub 60/

    International Nuclear Information System (INIS)

    Results of Cs ion induced C/sub 60/ fragmentation in source of negative ions by cesium sputtering (SNICS) from 5 MeV Tandem accelerator are presented. The mass analysis was performed from bending magnet. Mass spectra of C/sub 60/ fragments are compared with that of graphite under similar conditions. Yield of carbon clusters for both cases is plotted for Cs ion energy range of 2-5 keV. It is observed that heavier clusters appear in the case of C/sub 60/. Intensity of C/sub 2/ is much higher in comparison with other clusters for both C/sub 60/ and graphite due to difference in their bond energies. Prominence of C/sub 2/ yield confirms formation mechanism of C/sub 60/ by addition of C/sub 2/ route. (author)

  6. Ion bombardment-induced surface roughness of solids

    International Nuclear Information System (INIS)

    Surface roughness is considered here as a set of protuberances and depressions existing on a target surface. An important parameter which gives quantitative information about this geometrical property of the surface is the mean arithmetical deviation of the surface profile from a so-called mean line, i.e. a line that divides a surface contour in such a conventionally determined segment l, the sum of the second power deviations yi (i=1,2,...,n) of the contour from this line is a minimum. The parameter in question (often called the mean roughness, R, or simply the roughness, R) is defined as the mean value of the distances (y1, y2,...,yn) of points of a surface profile from the mean line measured over a range of the above-mentioned elementary segment l. In calculating r for surfaces that are modified by ion-beam irradiation, it must be taken into account that changes in the distances yi induced by ion-beam bombardment depend on many factors (related to the bombardment conditions and target material properties) and that almost all special features of ion-beam sputtering (the most popular ion-beam technique for surface roughness modification) depend directly or indirectly on the ion-beam incidence angle θ, where θ is measured form the surface normal. It can be shown that the changes in the heights (δy) of certain surface profiles induced by ion sputtering also depend on θ. (Author)

  7. Investigation of physiologically active products obtained from carbon-ion irradiated actinomycetes

    International Nuclear Information System (INIS)

    Charged particles such as carbon-ions are superior to X-rays or gamma-rays in the physical and biological characteristics. The propose research project is aimed to provide new insights on antibiotic development. Mutants were prepared by heavy ion irradiation, examined the effect of physiologically active substances produced. Product(s) from carbon-ion irradiated microorganera suppressed growth of human cololectal cancer cells and breast cancer cells. We suggested that carbon-ion irradiated actinomycetes produce antitumor active product(s) for cololectal and breast cancer cells. (author)

  8. SAGA-HIMAT project for carbon ion radiotherapy

    International Nuclear Information System (INIS)

    Project of SAGA Heavy Ion Medical Accelerator in Tosu (SAGA HIMAT) is promoted by Saga prefecture with private financial supports, investments, and also personal donations. With this funding, facility construction is conducted by a collaboration of SAGA-HIMAT foundation and SAGA HIMAT company. The facility is constructing in Tosu-shi near Shinn-Tosu shinkansen station, which has easy access from Kyushu island area and also south west Japan. In the facility, there are three treatment rooms, where first one has been equipped with horizontal and 45 degree oblique beam lines, second one has horizontal and vertical beam lines, and third one is for future preparation of spot scanning irradiation system. Design of an accelerator itself is same as a therapy facility at Gunma University, i.e., acceleration ion is carbon, maximum beam energy is 400MeV/u, and maximum beam intensity is 1.3x109pps. An injection line to a synchrotron and transport lines to three treatment rooms had been rearranged. Designs of the accelerator and an irradiation system have started at beginning of 2010, and the construction of a facility building has started at beginning of this year (2011). Installations of accelerator devices are expected to start at beginning of 2012, and the facility is planned to complete in 2013. In this paper, we present our project and current status of the facility construction. (author)

  9. Glass carbon surface modified by the fluorine ion irradiation

    Science.gov (United States)

    Teranishi, Yoshikazu; Ishizuka, Masanori; Kobayashi, Tomohiro; Nakamura, Isao; Uematu, Takahiko; Yasuda, Takeshi; Mitsuo, Atsushi; Morikawa, Kazuo

    2012-02-01

    Application of nano and micro fabrication techniques in industry requires solution to some crucial problems. One of the significant problems is the sticking interface between mold surface and imprinted polymer. In this study, we report a solution to the sticking interface problem by modification of nano imprinting mold using fluorine ion implantation. After the fluorine implantation, anti sticking layer appeared on the nano imprinting mold surface. After the implantation, a mold made from glass like carbon was patterned by focused ion beam lithography. The pattern was made up of word "TIRI". The line width was varied with 300 nm, 500 nm, and 1 μm. The line depth was about 200 ˜ 300 nm. The average depth of implanted fluorine was approximately 90 nm. After imprinting, the resin was removed from the mold by mechanical lift-off process. Transferred pattern was observed and confirmed by a scanning electron microscope (SEM) and an atomic force microscope (AFM). The pattern transferred from mold to resin was found to be successful.

  10. Glass carbon surface modified by the fluorine ion irradiation

    International Nuclear Information System (INIS)

    Application of nano and micro fabrication techniques in industry requires solution to some crucial problems. One of the significant problems is the sticking interface between mold surface and imprinted polymer. In this study, we report a solution to the sticking interface problem by modification of nano imprinting mold using fluorine ion implantation. After the fluorine implantation, anti sticking layer appeared on the nano imprinting mold surface. After the implantation, a mold made from glass like carbon was patterned by focused ion beam lithography. The pattern was made up of word “TIRI”. The line width was varied with 300 nm, 500 nm, and 1 μm. The line depth was about 200 ∼ 300 nm. The average depth of implanted fluorine was approximately 90 nm. After imprinting, the resin was removed from the mold by mechanical lift-off process. Transferred pattern was observed and confirmed by a scanning electron microscope (SEM) and an atomic force microscope (AFM). The pattern transferred from mold to resin was found to be successful.

  11. Glass carbon surface modified by the fluorine ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Teranishi, Yoshikazu, E-mail: teranishi.yoshikazu@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute (TIRI), Nishigaoka 3-13-10, Kitaku, Tokyo 115-8586 (Japan); Ishizuka, Masanori [Tokyo University, Inst. of Phys. and Chem. Res., RIKEN (Japan); Kobayashi, Tomohiro [Chuo University, Inst. of Phys. and Chem. Res., RIKEN (Japan); Nakamura, Isao; Uematu, Takahiko; Yasuda, Takeshi; Mitsuo, Atsushi; Morikawa, Kazuo [Tokyo Metropolitan Industrial Technology Research Institute (TIRI), Nishigaoka 3-13-10, Kitaku, Tokyo 115-8586 (Japan)

    2012-02-01

    Application of nano and micro fabrication techniques in industry requires solution to some crucial problems. One of the significant problems is the sticking interface between mold surface and imprinted polymer. In this study, we report a solution to the sticking interface problem by modification of nano imprinting mold using fluorine ion implantation. After the fluorine implantation, anti sticking layer appeared on the nano imprinting mold surface. After the implantation, a mold made from glass like carbon was patterned by focused ion beam lithography. The pattern was made up of word 'TIRI'. The line width was varied with 300 nm, 500 nm, and 1 {mu}m. The line depth was about 200 {approx} 300 nm. The average depth of implanted fluorine was approximately 90 nm. After imprinting, the resin was removed from the mold by mechanical lift-off process. Transferred pattern was observed and confirmed by a scanning electron microscope (SEM) and an atomic force microscope (AFM). The pattern transferred from mold to resin was found to be successful.

  12. Ion beam induced luminescence characterisation of CVD diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A.; Gonon, P.; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    The characterisation of the band structure properties of materials and devices by ion microprobe techniques has been made possible at the Melbourne MeV ion microprobe facility with the development of Ion Beam Induced Luminescence (IBIL). A number of diamond films grown by Microwave Plasma Chemical Vapour Deposition (MPCVD) on silicon substrates are analysed. A preliminary study of the luminescence properties of these samples has revealed information not previously obtainable via traditional microprobe techniques. The optical effects of incorporating dopants during the deposition process is determined using IBIL. The presence of trace element impurities introduced during growth is examined by Particle Induced X-ray Emission (PIXE), and a measurement of the film thickness is made using Rutherford Backscattering Spectrometry (RBS). 7 refs., 2 figs.

  13. Light-ion-induced multifragmentation. A fast, evolutionary process

    International Nuclear Information System (INIS)

    GeV light-ion-induced reactions offer a unique tool for preparing hot, dilute nuclear matter. Time evolution of nuclear multifragmentation in 3He + natAg and 3He + 197Au reactions are investigated. Fragment-fragment correlations are studied in order to gain information on multifragmentation mechanism. (K.A.)

  14. Light-ion-induced multifragmentation. A fast, evolutionary process

    Energy Technology Data Exchange (ETDEWEB)

    Viola, V.E.; Bracken, D.S.; Foxford, E.R.; Ginger, D.; Kwiatkowski, K.; Morley, K.B.; Hsi, W.C.; Wang, G. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry; Korteling, R.G. [Simon Fraser Univ., Burnaby, BC (Canada). Dept. of Chemistry; Legrain, R. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee] [and others

    1996-09-01

    GeV light-ion-induced reactions offer a unique tool for preparing hot, dilute nuclear matter. Time evolution of nuclear multifragmentation in {sup 3}He + {sup nat}Ag and {sup 3}He + {sup 197}Au reactions are investigated. Fragment-fragment correlations are studied in order to gain information on multifragmentation mechanism. (K.A.). 15 refs.

  15. Effects of Carbon Ions on Primary Cultures of Mouse Brain Cells

    Science.gov (United States)

    Nojima, K.; Ando, K.; Fujiwara, H.; Ando, S.

    Primary mixed cultures of astrocytes and microglia were obtained from neonatal mice, and were irradiated with high-LET carbon ions. Immunohistochemical staining showed astrocytes survived more prominently than microglia. Tagged with specific antibodies, astrocytes and microglia surviving after irradiation were counted by flow cytometry. Decreases in the number of microglia and astrocytes were detected at a dose as small as 2 Gy when Day 5 cultures were irradiated with 13 keV/μm carbon ions. When the cultures were irradiated on Day 10, the dose-dependent decrease of microglia was more prominent for 13 keV/μun carbon ions than 70 keV/μm carbon ions. Astrocytes showed a marginal decrease at Day 10 and Day 14. We concluded that microglia are more sensitive than astrocytes to carbon ions and X-rays, and that the radiosensitivity of microglia depends on both differentiation/proliferation status and radiation quality

  16. Comparison of the Effects of Carbon Ion and Photon Irradiation on the Angiogenic Response in Human Lung Adenocarcinoma Cells

    International Nuclear Information System (INIS)

    Purpose: Radiotherapy resistance is a commonly encountered problem in cancer treatment. In this regard, stabilization of endothelial cells and release of angiogenic factors by cancer cells contribute to this problem. In this study, we used human lung adenocarcinoma (A549) cells to compare the effects of carbon ion and X-ray irradiation on the cells' angiogenic response. Methods and Materials: A549 cells were irradiated with biologically equivalent doses for cell survival of either carbon ions (linear energy transfer, 170 keV/μm; energy of 9.8 MeV/u on target) or X-rays and injected with basement membrane matrix into BALB/c nu/nu mice to generate a plug, allowing quantification of angiogenesis by blood vessel enumeration. The expression of angiogenic factors (VEGF, PlGF, SDF-1, and SCF) was assessed at the mRNA and secreted protein levels by using real-time reverse transcription-PCR and enzyme-linked immunosorbent assay. Signal transduction mediated by stem cell factor (SCF) was assessed by phosphorylation of its receptor c-Kit. For inhibition of SCF/c-Kit signaling, a specific SCF/c-Kit inhibitor (ISCK03) was used. Results: Irradiation of A549 cells with X-rays (6 Gy) but not carbon ions (2 Gy) resulted in a significant increase in blood vessel density (control, 20.71 ± 1.55; X-ray, 36.44 ± 3.44; carbon ion, 16.33 ± 1.03; number per microscopic field). Concordantly, irradiation with X-rays but not with carbon ions increased the expression of SCF and subsequently caused phosphorylation of c-Kit in endothelial cells. ISCK03 treatment of A549 cells irradiated with X-rays (6 Gy) resulted in a significant decrease in blood vessel density (X-ray, 36.44 ± 3.44; X-ray and ISCK03, 4.33 ± 0.71; number of microscopic field). These data indicate that irradiation of A549 cells with X-rays but not with carbon ions promotes angiogenesis. Conclusions: The present study provides evidence that SCF is an X-ray-induced mediator of angiogenesis in A549 cells, a phenomenon that

  17. Carbon nanotube film anodes for flexible lithium ion batteries

    Science.gov (United States)

    Yoon, Sora; Lee, Sehyun; Kim, Soyoung; Park, Kyung-Won; Cho, Daehwan; Jeong, Youngjin

    2015-04-01

    In this study, carbon nanotube (CNT) film anodes are prepared for use in flexible lithium ion batteries, and the electrochemical performance of the CNT film anodes is evaluated. The CNT films are synthesized via chemical vapor deposition and direct spinning. The films are heat-treated under a nitrogen atmosphere at a high temperature to study the effects of heat treatment on the battery performance. The electrodes made with the CNT films are characterized via charge-discharge test, cyclic voltammetry, and impedance measurement. The results indicate that batteries with films heat-treated under a nitrogen atmosphere show a higher capacity, which can be a result of their high crystalline perfection. The impedance analysis shows that a lower resistance at the interface can be obtained by using heat-treated films. The charge-discharge tests are carried out by adjusting the rate from C/2 to 10C, and when the rate slows from 10C to 1C, the capacity of the samples largely recovers. The nitrogen/heat-treated CNT film electrodes present a capacity that is twice as high, such as 2C, 5C, and 10C, than untreated CNT film electrodes. These results indicate that the carbon nanotube film anodes have high potential for use in portable and wearable computers due to their flexibility.

  18. Microbeam Studies of Diffusion Time Resolved Ion Beam Induced Charge Collection from Stripe-Like Junctions

    International Nuclear Information System (INIS)

    To design more radiation tolerant Integrated Circuits (ICs), it is essential to create and test accurate models of ionizing radiation induced charge collection dynamics within microcircuits. A new technique, Diffusion Time Resolved Ion Beam Induced Charge Collection (DTRIBICC), is proposed to measure the average arrival time of the diffused charge at the junction. Specially designed stripe-like junctions were experimentally studied using a 12 MeV carbon microbeam with a spot size of 1 microm. The relative arrival time of ion-generated charge is measured along with the charge collection using a multiple parameter data acquisition system. The results show the importance of the diffused charge collection by junctions, which is especially significant in accounting for Multiple Bit Upset (MBUs) in digital devices

  19. Contribution of nitric oxide radicals in bystander and adaptive responses induced by heavy ion-beams

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate whether radioadaptive responses were induced after irradiation with accelerated ion beams through nitric oxide-mediated bystander response in cultured cells in vitro and in some organs of mice in vivo. Human non-small cell lung carcinoma cells transfected with wild-type p53 (H1299/wtp53 cells) were used. The cells were irradiated with accelerated neon (400 MeV/u, 31 keV/μm) or iron (500 MeV/u, 200 keV/μm) ion beams. Then, the cells were allowed forming colonies, were cultured for 48 h to obtained samples for Western blot analysis, or were cultured for several weeks to fix mutations in the locus of hprt gene. ICR male mice (Jcl:ICR) were used. The mice were irradiated on 2 days with accelerated carbon ion beams (290 MeV/u, 13 keV/μm) or argon ion beams (500 MeV/u, 90 keV/μm). The intestine and testis were excised 2 days after the last irradiation. These excised tissues were fixed, embedded in paraffin and made of thin-sections on slide glasses. Then the TdT-mediated dUTP-biotin nick end-labeling (TUNEL)- and activated caspase-3-positive cells in the thin-sections of tissues were detected by the immunohistochemical method. A significant reduction of mutation rate of the hprt gene was observed when the cells were challengingly irradiated after the priming irradiation with accelerate neon or iron ion beams. This reduction was partially suppressed by NO radical scavenger, carboxy-PTIO. The bystander-induced apoptotic and activated caspase-3-positive cells were obviously observed in unirradiated intestine and testis when mice were irradiated with carbon or argon ion beams across the upper body. These observations were partially suppressed by carboxy-PTIO into the peritoneal cavity. (author)

  20. Ion beam induced fluorescence imaging in biological systems

    Science.gov (United States)

    Bettiol, Andrew A.; Mi, Zhaohong; Vanga, Sudheer Kumar; Chen, Ce-belle; Tao, Ye; Watt, Frank

    2015-04-01

    Imaging fluorescence generated by MeV ions in biological systems such as cells and tissue sections requires a high resolution beam (system and a fluorescent probe that has a high quantum efficiency and low bleaching rate. For cutting edge applications in bioimaging, the fluorescence imaging technique needs to break the optical diffraction limit allowing for sub-cellular structure to be visualized, leading to a better understanding of cellular function. In a nuclear microprobe this resolution requirement can be readily achieved utilizing low beam current techniques such as Scanning Transmission Ion Microscopy (STIM). In recent times, we have been able to extend this capability to fluorescence imaging through the development of a new high efficiency fluorescence detection system, and through the use of new novel fluorescent probes that are resistant to ion beam damage (bleaching). In this paper we demonstrate ion beam induced fluorescence imaging in several biological samples, highlighting the advantages and challenges associated with using this technique.

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

    Science.gov (United States)

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

    2011-10-01

    This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms. PMID:21900733

  2. Ion-Induced Reactivity in Pyrene Clusters

    International Nuclear Information System (INIS)

    We report experimental indications of chemical reactions inside clusters of pyrene (C16H10) molecules following collisions with 11.25 keV He+ - and 12.0 keV Ar2+ ions. It appears that bond-forming reactions are more likely with the heavier projectile. We have also performed classical molecular dynamics simulations of these processes where we treat the interaction between the projectiles and all atoms in the cluster as well as non-dispersive and dispersive forces between all atoms in the cluster before, during and after the collision. The time step is typically 10−17 s and the total simulation time 1 picosecond. The simulations were performed for a fixed cluster size with 36 pyrene molecules, although there is a broad range of cluster sizes in the experiment. Still, there is good qualitative agreement between the experimental and the simulated mass spectra exhibiting reaction products with masses between those of the C16H10- monomer and dimer in both cases. Additional studies of the influence of the projectile charge and mass is planned as well as simulations on longer time scales and as functions of cluster size

  3. Mouse skin damages caused by fractionated irradiation with carbon ions

    International Nuclear Information System (INIS)

    We have investigated carbon-dose responses of early and late skin damages after daily fractionations to the mouse leg. Depilated legs were irradiated with 7 different positions within 290 MeV/u carbon beams. Fractionation schedules were 1, 2, 4 and 8 daily fractions. Skin reaction was scored every other day for 32 days. Five highest scores in individual mice were averaged, and used as averaged peak reaction. The isoeffect doses to produce an averaged peak skin reaction of 3.0 (moist desquamation) on dose-response curves were calculated with 95% confidence limit. The isoeffect dose for control gamma rays constantly increased with an increase in the number of fraction. The isoeffect doses in low LET carbon ions of 14- and 20 keV/μm also increased up to 4 fractions, but did not increase when 4 fractions increased to 8 fractions. The saturation of isoeffect dose was more prominently observed for 40 keV/μm in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/μm were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/μ steadily increased with an increase in the number of fraction and did not show any saturation up to 8 fractions. Relation between LET and RBE was linear for all fractionation schedules. The slope of regression line in 4 fractions was steepest, and significantly (P<0.05) different from that in 1 fraction. (orig.)

  4. Mouse skin damages caused by fractionated irradiation with carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Ando, K.; Chen, Y.J.; Ohira, C.; Nojima, K.; Ando, S.; Kobayashi, N.; Ohbuchi, T.; Shimizu, W. [Space and Particle Radiation Science Research Group, Chiba (Japan); Koike, S.; Kanai, T. [National Inst. of Radiological Sciences, Chiba (Japan). Div. of Accelerator Physics

    1997-09-01

    We have investigated carbon-dose responses of early and late skin damages after daily fractionations to the mouse leg. Depilated legs were irradiated with 7 different positions within 290 MeV/u carbon beams. Fractionation schedules were 1, 2, 4 and 8 daily fractions. Skin reaction was scored every other day for 32 days. Five highest scores in individual mice were averaged, and used as averaged peak reaction. The isoeffect doses to produce an averaged peak skin reaction of 3.0 (moist desquamation) on dose-response curves were calculated with 95% confidence limit. The isoeffect dose for control gamma rays constantly increased with an increase in the number of fraction. The isoeffect doses in low LET carbon ions of 14- and 20 keV/{mu}m also increased up to 4 fractions, but did not increase when 4 fractions increased to 8 fractions. The saturation of isoeffect dose was more prominently observed for 40 keV/{mu}m in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/{mu}m were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/{mu} steadily increased with an increase in the number of fraction and did not show any saturation up to 8 fractions. Relation between LET and RBE was linear for all fractionation schedules. The slope of regression line in 4 fractions was steepest, and significantly (P<0.05) different from that in 1 fraction. (orig.)

  5. Characteristics of Ions Emitted from Laser-Induced Silver Plasma

    Institute of Scientific and Technical Information of China (English)

    M. S. RAFIQUE; M. KHALEEQ-UR-RAHMAN; Shakoor MUNAZZA; K. A. BHATTI

    2008-01-01

    In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd:YAG laser, with a wavelength of 1064 nm, a pulsed width of 9~14 ns, a power of 1.1 MW and energy of 10 mJ, on silver target in vacuum (10'-3> Torr = 1.3332 Pa). The charac-teristics of ion streams were investigated by CR-39 detectors located at angles of 0°, 30°, 60° and 90° with respect to normal of the target. The distance between the silver target and each detector was 11 cm. The energy of silver ions was found ranging from 1.5 eV to 1.06E4 eV. There was a high concentration of ions with low energy as compared to those with high energy, showing the energy distribution amongst the ions. The flux of ions was maximum in the axial direction which was decreasing with the angle increase with respect to normal of the target, and finally became minimum in the radial direction. Hence the silver ions have shown anisotropic behaviour.

  6. Effect of intense laser and energetic ion irradiation on Raman modes of Multiwalled Carbon Nanotubes

    International Nuclear Information System (INIS)

    The effects of intense laser and energetic ion irradiation on Raman vibrational modes of Multiwalled Carbon Nanotubes have been investigated. The intensity ratio of D and G modes decreases with increase in laser power density and remains almost constant with decrease of laser power density. The intensity ratio of D mode to G mode for ion irradiated Multiwalled Carbon Nanotubes decreases at low fluence (4 x 1011 ions/cm2) and increases further with increase in ion fluence. The results show that ion irradiation at low fluence and laser irradiation lead to purification/ordering of the nanotubes.

  7. Mechanism of heavy ion radiation-induced cancer cell death

    International Nuclear Information System (INIS)

    We previously reported that the carbon beam triggers apoptosis in radio-resistant cancer cell lines via extracellular signal-regulated kinase (ERK)- and mitochondrial Bcl-2 family protein-dependant mechanism. Here, we further examined the further apoptosis-inducing mechanism of carbon beam in two glioma cell lines (T98G, U251). ERK1/2 knockdown experiments revealed that ERK regulates this apoptosis-inducing machinery upstream of mitochondria. Furthermore, we also found that both T98G cell and U251 cell stably expressing dominant-negative ERK2 suppress cell death induced by carbon beam irradiation. We also found proapoptotic PUMA and antiapoptotic Bcl-2 dynamically chang their expression levels corresponding to ERK activation after CB irradiation in U251 cell, and knockdown of PUMA decreased CB-induced U251 cell death. These data suggest that kinase action of ERK is essential for CB-induced glioma cell death, and proapoptotic PUMA and antiapoptotic Bcl-2 might be downstream targets of ERK in CB-induced glioma cell death mechanism. (author)

  8. Generation of intense pulsed ion beam by a Br type magnetically insulated ion diode with carbon plasma gun

    International Nuclear Information System (INIS)

    To apply the pulsed heavy ion beam (PHIB) to an implantation process of semiconductor, purity of the ion beam is very important. To obtain a pure PHIB we have proposed a new type of accelerator using bipolar pulse. To develop the accelerator we are developing a new type of Br ion diode using a carbon plasma gun. By using the plasma gun, ion source plasma of ion current density approx. = 30 A/cm2 was obtained. The Br ion diode was successfully operated with plasma gun at diode voltage approx. = 100 kV, diode current approx. = 1 kA, pulse duration approx. = 200 ns and 3 A/cm2 of ion current density was obtained. (author)

  9. Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries

    OpenAIRE

    Badi, Nacer; Erra, Abhinay Reddy; Hernandez, Francisco C. Robles; Okonkwo, Anderson O; Hobosyan, Mkhitar; Martirosyan, Karen S

    2014-01-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low wo...

  10. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

    International Nuclear Information System (INIS)

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H0, H2+ and H3+ projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H2+ and H3+ polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  11. Late quaternary fluctuations in carbonate and carbonate ion content in the northern Indian ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.S.

    =] of the water bathing the core tops, were computed from different GEOSECS staions for the Westrn and Eastern Indian Ocean separately (Table 2,3 & 4, Fig. 9 &14). GEOSECS taion Nos. 417,420 and 425 whic lie along a transect in the westrn Indian Ocean...-normalized carbonate ion (CO3=*) range from 90 to 125µmol kg-1 in the tropical region of the world oceans with a weight los of 0.3 ± 0.05µg mol -1kg-1 (Broecker and Clark, 201d). Botm water CO3=* concentration bathing the core tops are in the range of 88 to 13 μmolkg-1...

  12. Ion implanted pyrolitic carbon for the hip prosthesis

    International Nuclear Information System (INIS)

    Full text: Hip joint arthroplasty is a successful surgical procedure, but loosening induced by polyethylene wear debris continues to be a problem. Fine grained isotropic graphite (POCO ZXF-5Q) coated with Pyrolite (trademark of Carbomedics Inc.) combines biocompatibility, strength and tribological properties which could be utilised in a hip prosthesis. Some preliminary work has been conducted on this material, and the effect nitrogen ion implantation has on its wear resistance. Finite element analysis was conducted on a femoral head of a canine hip prosthesis with diameter 19mm made from POCO ZXF-5Q . An optimum design was obtained after design variables such as taper angle and width, internal recess radius, crown thickness were varied so that internal stresses were minimised. This was then translated into an human sized femoral head with diameter 28mm, which was subjected to mechanical testing. Loading was at 20 deg C to the taper, with loading rate 10kN/s used in static loading, whilst fatigue testing was carried out between 300 - 3000N at 30Hz for 107 cycles. Pin-on-disc wear testing was carried out using a CSEM Tribometer. A 1N load was applied to 6mm diameter pins. Wear track radii were 11 and 13mm, with linear velocity 5cm/s and sliding distance 2.5km. Test temperature was 37±1degC with Ringer solution and bovine serum being used as lubricant. Nitrogen implanted samples were irradiated to a dose of 5x1016 ions.cm-2 at 50keV. Static testing was carried out to loads of 8000N and all five POCO ZXF-5Q femoral heads tested survived. Then three of these pre-tested femoral heads were subjected to fatigue testing and no failures occured before 107 cycles. Wear was reduced by nitrogen ion implantation only when an irradiated pin was tested against as polished Pyrolite. Nitrogen ion implanted Pyrolite on a POCO ZXF-5Q substrate may have clinical potential. The substrate has appropriate mechanical properties, and nitrogen ion implantation can improve the already

  13. Reduction of ion beam induced and atmospheric ageing of porous silicon using Al and SiO2 caps

    International Nuclear Information System (INIS)

    Ion beam analysis data are presented on both freshly prepared and 'aged' porous silicon layers of widely varying (10-85%) porosity. Both evaporated Al and PECVD SiO2 surface capping layers are shown to suppress some of the rapid ion beam induced changes in chemical composition that have been reported during analysis of uncapped layers. Specifically, these capping layers were successful in eliminating carbon and oxygen accumulation within the material but they only slightly reduced hydrogen loss under ion bombardment. Evaporated aluminium surface capping layers were partially successful in suppressing long term ambient oxygen pick-up. (author)

  14. Development of Compact Electron Cyclotron Resonance Ion Source with Permanent Magnets for High-Energy Carbon-Ion Therapy

    Science.gov (United States)

    Muramatsu, M.; Kitagawa, A.; Iwata, Y.; Hojo, S.; Sakamoto, Y.; Sato, S.; Ogawa, Hirotsugu; Yamada, S.; Ogawa, Hiroyuki; Yoshida, Y.; Ueda, T.; Miyazaki, H.; Drentje, A. G.

    2008-11-01

    Heavy-ion cancer treatment is being carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) with 140 to 400 MeV/n carbon ions at National Institute of Radiological Sciences (NIRS) since 1994. At NIRS, more than 4,000 patients have been treated, and the clinical efficiency of carbon ion radiotherapy has been demonstrated for many diseases. A more compact accelerator facility for cancer therapy is now being constricted at the Gunma University. In order to reduce the size of the injector (consists of ion source, low-energy beam transport and post-accelerator Linac include these power supply and cooling system), an ion source requires production of highly charged carbon ions, lower electric power for easy installation of the source on a high-voltage platform, long lifetime and easy operation. A compact Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets is one of the best types for this purpose. An ECRIS has advantage for production of highly charged ions. A permanent magnet is suitable for reduce the electric power and cooling system. For this, a 10 GHz compact ECRIS with all permanent magnets (Kei2-source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas-injection side, while the minimum B strength is 0.25 T. These parameters have been optimized for the production of C4+ based on experience at the 10 GHz NIRS-ECR ion source. The Kei2-source has a diameter of 320 mm and a length of 295 mm. The beam intensity of C4+ was obtained to be 618 eμA under an extraction voltage of 30 kV. Outline of the heavy ion therapy and development of the compact ion source for new facility are described in this paper.

  15. Development of Compact Electron Cyclotron Resonance Ion Source with Permanent Magnets for High-Energy Carbon-Ion Therapy

    International Nuclear Information System (INIS)

    Heavy-ion cancer treatment is being carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) with 140 to 400 MeV/n carbon ions at National Institute of Radiological Sciences (NIRS) since 1994. At NIRS, more than 4,000 patients have been treated, and the clinical efficiency of carbon ion radiotherapy has been demonstrated for many diseases. A more compact accelerator facility for cancer therapy is now being constricted at the Gunma University. In order to reduce the size of the injector (consists of ion source, low-energy beam transport and post-accelerator Linac include these power supply and cooling system), an ion source requires production of highly charged carbon ions, lower electric power for easy installation of the source on a high-voltage platform, long lifetime and easy operation. A compact Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets is one of the best types for this purpose. An ECRIS has advantage for production of highly charged ions. A permanent magnet is suitable for reduce the electric power and cooling system. For this, a 10 GHz compact ECRIS with all permanent magnets (Kei2-source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas-injection side, while the minimum B strength is 0.25 T. These parameters have been optimized for the production of C4+ based on experience at the 10 GHz NIRS-ECR ion source. The Kei2-source has a diameter of 320 mm and a length of 295 mm. The beam intensity of C4+ was obtained to be 618 eμA under an extraction voltage of 30 kV. Outline of the heavy ion therapy and development of the compact ion source for new facility are described in this paper.

  16. Adsorption efficiencies of calcium (II ion and iron (II ion on activated carbon obtained from pericarp of rubber fruit

    Directory of Open Access Journals (Sweden)

    Orawan Sirichote

    2008-03-01

    Full Text Available Determination of adsorption efficiencies of activated carbon from pericarp of rubber fruit for calcium (II ion and iron (II ion has been performed by flowing the solutions of these ions through a column of activated carbon. The weights of activated carbon in 500 mL buret column (diameter 3.2 cm for flowing calcium (II ion and iron (II ion solutions were 15 g and 10 g, respectively. The initial concentration of calcium ion was prepared to be about eight times more diluted than the true concentration found in the groundwater from the lower part of southern Thailand. Calcium (II ion concentrations were analysed by EDTA titration and its initial concentration was found to be 23.55 ppm. With a flow rate of 26 mL/min, the adsorption efficiency was 11.4 % with passed through volume 4.75 L. Iron (II ion concentrations were analysed by spectrophotometric method; its initial concentration was found to be 1.5565 ppm. At a flow rate of 22 mL/min, the adsorption efficiency was 0.42 % with passed through volume of 34.0 L.

  17. Helium ion beam induced growth of hammerhead AFM probes

    NARCIS (Netherlands)

    Nanda, G.; Van Veldhoven, E.; Maas, D.; Sadeghian, H.; Alkemade, P.F.A.

    2015-01-01

    The authors report the direct-write growth of hammerhead atomic force microscope(AFM) probes by He+beam induced deposition of platinum-carbon. In order to grow a thin nanoneedle on top of a conventional AFM probe, the authors move a focused He+beam during exposure to a PtC precursor gas. In the fina

  18. Helium ion beam induced growth of hammerhead AFM probes

    NARCIS (Netherlands)

    Nanda, G.; Veldhoven, E. van; Maas, D.J.; Sadeghian Marnani, H.; Alkemade, P.F.A.

    2015-01-01

    The authors report the direct-write growth of hammerhead atomic force microscope (AFM) probes by He+ beam induced deposition of platinum-carbon. In order to grow a thin nanoneedle on top of a conventional AFM probe, the authors move a focused He+ beam during exposure to a PtC precursor gas. In the f

  19. Pigment analysis of a color-leaf mutant in Wandering Jew (Tradescantia fluminensis) irradiated by carbon ions

    International Nuclear Information System (INIS)

    Many mutants of plant induced by heavy ion beam irradiation have been reported in recent years, but leaf anthocyan mutants induced by ion irradiation in evergreen were rarely found. In this study, a color-leaf mutant with purple leaves, stems and petals was isolated from clones of Wandering Jew irradiated by 95.8 MeV/u carbon ion beam. The concentration and histological distribution of leaf pigment were surveyed in wild type and mutant. In mutant, contents of total chlorophylls (Chl), chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Car) decreased significantly, while concentration of the anthocyanins was 6.2-fold higher than that of wild type. Further composition analysis of anthocyanins by electrospray ionization mass spectrometry (ESI-MS) indicated that the purple pigmentation of leaves in mutant was caused by accumulation of petunidin anthocyanin. Microscopic examination showed that most petunidin anthocyanin accumulated in the lower epidermis, and little in vascular parenchyma of mutant, while there was no pigment in wild type. Meanwhile, in spongy parenchyma of mutant we observed little Chl, which the wild type abounds in. In conclusion, the color-leaf mutant of Wandering Jew induced by irradiation of carbon ions was improved in ornamental value, and it could be contribute to variation in level, component and distribution of foliar pigment. The possible mutation mechanisms were discussed. (authors)

  20. Molecular analysis of heavy ion induced mutations in the budding yeast

    International Nuclear Information System (INIS)

    The aim of this study is to elucidate the molecular mechanism of mutagenesis caused with heavy ion irradiation. Yeast cells were irradiated with accelerated carbon ion (290 MeV/u, 13-75 keV/mm) and helium ion (150 MeV/u, 2.2 keV/mm). The survival rate of carbon ion beam irradiated cells was reduced with linear energy transfer (LET), and the mutation frequency increased consistently with LET. The survival rate of helium ion beam (0.45 keV/mm) was slightly higher than that of carbon ion beam (LET: 25 keV/ mm) irradiated cells. (author)

  1. Microbially induced corrosion of carbon steel in deep groundwater environment

    Science.gov (United States)

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland) for periods of 3 and 8 months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel. PMID:26257707

  2. Microbially induced corrosion of carbon steel in deep groundwater environment

    Directory of Open Access Journals (Sweden)

    Pauliina eRajala

    2015-07-01

    Full Text Available The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland for periods of three and eight months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel.

  3. Microbially induced corrosion of carbon steel in deep groundwater environment.

    Science.gov (United States)

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland) for periods of 3 and 8 months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel. PMID:26257707

  4. Rapid ion-beam-induced Ostwald ripening in two dimensions

    International Nuclear Information System (INIS)

    Ion-beam-induced grain coarsening in initially amorphous (Zr,Y)Ox layers is observed by atomic force microscopy. The films were bombarded at room temperature. Grain-boundary grooves indicate that the larger grains have a diameter of about 83 nm at 2 min, and 131 nm at 5 min. Up to 5 min, the grain size evolves with time as tβ, with β=0.5±0.2. Based on a new parametrization of ion-induced grain-boundary translation, we derive a theoretical estimate of β=3/7, consistent with our measurement. By 7.5 min, many of the grain-boundary grooves are shallow and indistinct, suggesting that the surviving grains are mutually well aligned. Such rapid grain growth at room temperature is unusual and is enabled by the ion bombardment. Similar grain growth processes are expected during ion-beam-assisted deposition film growth. The status of ion-textured yttria stabilized zirconia films as buffer layers for high-current high-temperature superconducting films is briefly summarized

  5. Nanopillar growth by focused helium ion-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ping; Salemink, Huub W M; Alkemade, Paul F A [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Veldhoven, Emile van; Maas, Diederik J [TNO Science and Industry, Stieltjesweg 1, 2628 CK Delft (Netherlands); Sanford, Colin A [Carl Zeiss SMT, Inc., One Corporation Way, Peabody, MA 01960 (United States); Smith, Daryl A; Rack, Philip D, E-mail: p.f.a.alkemade@tudelft.nl [Department of Material Science and Engineering, University of Tennessee, Knoxville, TN 37996-2200 (United States)

    2010-11-12

    A 25 keV focused helium ion beam has been used to grow PtC nanopillars on a silicon substrate by beam-induced decomposition of a (CH{sub 3}){sub 3}Pt(C{sub P}CH{sub 3}) precursor gas. The ion beam diameter was about 1 nm. The observed relatively high growth rates suggest that electronic excitation is the dominant mechanism in helium ion-beam-induced deposition. Pillars grown at low beam currents are narrow and have sharp tips. For a constant dose, the pillar height decreases with increasing current, pointing to depletion of precursor molecules at the beam impact site. Furthermore, the diameter increases rapidly and the total pillar volume decreases slowly with increasing current. Monte Carlo simulations have been performed with realistic values for the fundamental deposition processes. The simulation results are in good agreement with experimental observations. In particular, they reproduce the current dependences of the vertical and lateral growth rates and of the volumetric deposition efficiency. Furthermore, the simulations reveal that the vertical pillar growth is due to type-1 secondary electrons and primary ions, while the lateral outgrowth is due to type-2 secondary electrons and scattered ions.

  6. Nanopillar growth by focused helium ion-beam-induced deposition

    International Nuclear Information System (INIS)

    A 25 keV focused helium ion beam has been used to grow PtC nanopillars on a silicon substrate by beam-induced decomposition of a (CH3)3Pt(CPCH3) precursor gas. The ion beam diameter was about 1 nm. The observed relatively high growth rates suggest that electronic excitation is the dominant mechanism in helium ion-beam-induced deposition. Pillars grown at low beam currents are narrow and have sharp tips. For a constant dose, the pillar height decreases with increasing current, pointing to depletion of precursor molecules at the beam impact site. Furthermore, the diameter increases rapidly and the total pillar volume decreases slowly with increasing current. Monte Carlo simulations have been performed with realistic values for the fundamental deposition processes. The simulation results are in good agreement with experimental observations. In particular, they reproduce the current dependences of the vertical and lateral growth rates and of the volumetric deposition efficiency. Furthermore, the simulations reveal that the vertical pillar growth is due to type-1 secondary electrons and primary ions, while the lateral outgrowth is due to type-2 secondary electrons and scattered ions.

  7. TL response of Eu activated LiF nanocubes irradiated by 85 MeV carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Salah, Numan, E-mail: nsalah@kau.edu.sa [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alharbi, Najlaa D. [Sciences Faculty for Girls, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Habib, Sami S. [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Lochab, S.P. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-09-01

    Carbon ions were found to be effective for cancer treatment. These heavy ions have a high relative biological effectiveness compared to those of photons. They have higher linear energy transfer and sharper Bragg peak with a very excellent local tumor control. However, the dose of these swift heavy ions needs to be measured with great accuracy. Lithium fluoride (LiF) is a highly sensitive phosphor widely used for radiation dosimetry. In this work Eu activated LiF nanocubes were exposed to 85 MeV C{sup 6+} ion beam and evaluated for their thermoluminescence (TL) response. Pellet forms of this nanomaterial were exposed to these ions in the fluence range 10{sup 9}–10{sup 13} ions/cm{sup 2}. The obtained result shows a prominent TL glow peak at around 320 °C, which is different than that induced by gamma rays. This glow peak exhibits a linear response in the range 10{sup 9}–10{sup 12} ions/cm{sup 2}, corresponding to the equivalent absorbed doses 0.273–273 kGy. The absorbed doses, penetration depths and main energy loss were calculated using TRIM code based on the Monte Carlo simulation. The supralinearity function and stopping power in this nanomaterial were also studied. The modification induced in the glow curve structure as a result of changing irradiation type might be utilized to use LiF:Eu nanocubes as a dosimeter for mixed filed radiations. Moreover, the wide linear response of LiF:Eu nanocubes along with the low fading are another imperative results suggesting that this nanomaterial might be a good candidate for carbon ions dosimetry.

  8. Biological effects induced by low-density heavy ions of space radiation in medaka

    International Nuclear Information System (INIS)

    Starting Japanese astronauts staying in the International Space Station (ISS), influences of the radiation on human is becoming one of the important risks during space flight. Although the biological effect with high-dose acute irradiation has been examined by epidemiological studies for many years, the risks either acute or chronic with low-dose or low-fluence irradiation equivalent of space environment can only be estimated based on the data with high-dose or high-fluence at present. Our aim is to understand biological influences on living organisms induced by low-dose and low-fluence chronic irradiation (1 mGy/7-8 h) that assumes the space radiation in ISS. So that we focused on the gene and protein expression, and the possibility on carcinogenesis induced by low-dose and -fluence radiation, and planed the experiments to irradiate medaka carbon ions using Heavy Ion Medical Accelerator in Chiba (HIMAC) in National Institute of Radiological Sciences (NIRS). This year, we established the irradiation method to treat medaka with low-dose and -fluence (1 mGy/7-8 h) carbon ions. Also we extracted total RNA from medaka scales and skins to evaluate the effect of irradiation. (author)

  9. Investigation of ion induced bending mechanism for nanostructures

    International Nuclear Information System (INIS)

    Ion induced bending is a promising controlled technique for manipulating nanoscale structures. However, the underlying mechanism of the process is not well understood. In this letter, we report a detailed study of the bending mechanism of Si nanowires (NWs) under Ga+ irradiation. The microstructural changes in the NW due to ion beam irradiation are studied and molecular dynamics simulations are used to explore the ion–NW interaction processes. The simulation results are compared with the microstructural studies of the NW. The investigations inform a generic understanding of the bending process in crystalline materials, which we suggest to be feasible as a versatile manipulation and integration technique in nanotechnology. (paper)

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2011-08-01

    We have investigated the damage of synthetic plasmid pBR322 DNA in dilute aqueous solutions induced by fast carbon ions. The relative contribution of indirect damage and direct damage to the DNA itself is expected to vary with linear energy transfer along the ion track, with the direct damage contribution increasing towards the Bragg peak. Therefore, 12C ions at the spread-out Bragg peak (dose averaged LET∞ = 189 ± 15 keV/ μm) and in the plateau region of the Bragg curve (LET = 40 keV/ μm) were employed and the radical scavenger concentration in the plasmid solution was varied to quantify the indirect effect. In order to minimize the influence of 12C break-up fragments, a relatively low initial energy of 90 MeV/nucleon was employed for the carbon ions. DNA damage has been quantified by subsequent electrophoresis on agarose gels. We find that strand breaks due to both indirect and direct effects are systematically higher in the plateau region as compared to the Bragg peak region with the difference being smallest at high scavenging capacities. In view of the fact that the relative biological effectiveness for many biological endpoints is maximum at the Bragg peak our findings imply that DNA damage at the Bragg peak is qualitatively most severe.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dang, H.M.; Van Goethem, M.J.; Van der Graaf, E.R.; Brandenburg, S.; Hoekstra, R.; Schlatholtera, T. [KVI University of Groningen, Zernikelaan 25, 9747AA Groningen (Netherlands)

    2011-08-15

    We have investigated the damage of synthetic plasmid pBR322 DNA in dilute aqueous solutions induced by fast carbon ions. The relative contribution of indirect damage and direct damage to the DNA itself is expected to vary with linear energy transfer along the ion track, with the direct damage contribution increasing towards the Bragg peak. Therefore, {sup 12}C ions at the spread-out Bragg peak (dose averaged LET{sub {infinity} }= (189 {+-} 15) keV/{mu}m) and in the plateau region of the Bragg curve (LET = 40 keV/{mu}m) were employed and the radical scavenger concentration in the plasmid solution was varied to quantify the indirect effect. In order to minimize the influence of {sup 12}C break-up fragments, a relatively low initial energy of 90 MeV/nucleon was employed for the carbon ions. DNA damage has been quantified by subsequent electrophoresis on agarose gels. We find that strand breaks due to both indirect and direct effects are systematically higher in the plateau region as compared to the Bragg peak region with the difference being smallest at high scavenging capacities. In view of the fact that the relative biological effectiveness for many biological endpoints is maximum at the Bragg peak our findings imply that DNA damage at the Bragg peak is qualitatively most severe. (authors)

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

    International Nuclear Information System (INIS)

    We have investigated the damage of synthetic plasmid pBR322 DNA in dilute aqueous solutions induced by fast carbon ions. The relative contribution of indirect damage and direct damage to the DNA itself is expected to vary with linear energy transfer along the ion track, with the direct damage contribution increasing towards the Bragg peak. Therefore, 12C ions at the spread-out Bragg peak (dose averaged LET∞ = (189 ± 15) keV/μm) and in the plateau region of the Bragg curve (LET = 40 keV/μm) were employed and the radical scavenger concentration in the plasmid solution was varied to quantify the indirect effect. In order to minimize the influence of 12C break-up fragments, a relatively low initial energy of 90 MeV/nucleon was employed for the carbon ions. DNA damage has been quantified by subsequent electrophoresis on agarose gels. We find that strand breaks due to both indirect and direct effects are systematically higher in the plateau region as compared to the Bragg peak region with the difference being smallest at high scavenging capacities. In view of the fact that the relative biological effectiveness for many biological endpoints is maximum at the Bragg peak our findings imply that DNA damage at the Bragg peak is qualitatively most severe. (authors)

  14. Ion implantation induced nanotopography on titanium and bone cell adhesion

    Science.gov (United States)

    Braceras, Iñigo; Vera, Carolina; Ayerdi-Izquierdo, Ana; Muñoz, Roberto; Lorenzo, Jaione; Alvarez, Noelia; de Maeztu, Miguel Ángel

    2014-08-01

    Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40-80 keV), fluence (1-2 e17 ion/cm2) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted surfaces, without surface chemistry modification, are in the same range and that such modifications, in certain conditions, do have a statistically significant effect on bone tissue forming cell adhesion.

  15. Application of Carbon Nanomaterials in Lithium-Ion Battery Electrodes

    Science.gov (United States)

    Jaber-Ansari, Laila

    Carbon nanomaterials such as single-walled carbon nanotubes (SWCNTs) and graphene have emerged as leading additives for high capacity nanocomposite lithium ion battery electrodes due to their ability to improve electrode conductivity, current collection efficiency, and charge/discharge rate for high power applications. In this work, the these nanomaterials have been developed and their properties have been fine-tuned to help solve fundamental issues in conventional lithium ion battery electrodes. Towards this end, the application of SWCNTs in lithium-ion anodes has been studied. As-grown SWCNTs possess a distribution of physical and electronic structures, and it is of high interest to determine which subpopulations of SWCNTs possess the highest lithiation capacity and to develop processing methods that can enhance the lithiation capacity of underperforming SWCNT species. Towards this end, SWCNT electronic type purity is controlled via density gradient ultracentrifugation, enabling a systematic study of the lithiation of SWCNTs as a function of metal versus semiconducting content. Experimentally, vacuum filtered freestanding films of metallic SWCNTs are found to accommodate lithium with an order of magnitude higher capacity than their semiconducting counterparts. In contrast, SWCNT film densification leads to the enhancement of the lithiation capacity of semiconducting SWCNTs to levels comparable to metallic SWCNTs, which is corroborated by theoretical calculations. To understand the interaction of the graphene with lithium ions and electrolyte species during electrochemical we use Raman spectroscopy in a model system of monolayer graphene transferred on a Si(111) substrate and density functional theory (DFT) to investigate defect formation as a function of lithiation. This model system enables the early stages of defect formation to be probed in a manner previously not possible with commonly-used reduced graphene oxide or multilayer graphene substrates. Using ex

  16. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    International Nuclear Information System (INIS)

    Application of pulsed high negative voltage (∼10 μs pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron microscopy, and its structure characteristics are examined by XPS and laser Raman spectroscopy. Subsequent processing using acetylene or acetylene and Ar (20%) produced thin carbon layers that are confirmed to be graphite-dominated DLC. Also, this PSII method is employed in order to deposit the DLC layer on the inside surface of the PET bottle and to reduce oxygen permeation rate by 40%

  17. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    Science.gov (United States)

    Tanaka, T.; Yoshida, M.; Shinohara, M.; Takagi, T.

    2002-05-01

    Application of pulsed high negative voltage (~10 μs pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron microscopy, and its structure characteristics are examined by XPS and laser Raman spectroscopy. Subsequent processing using acetylene or acetylene and Ar (20%) produced thin carbon layers that are confirmed to be graphite-dominated DLC. Also, this PSII method is employed in order to deposit the DLC layer on the inside surface of the PET bottle and to reduce oxygen permeation rate by 40%.

  18. Swift heavy ion induced modification of aliphatic polymers

    International Nuclear Information System (INIS)

    In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy Ion Research (GSI) in Darmstadt. In order to study ion-beam induced degradation, all polymer foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (U, Au, Sm, Xe) and experimentation sites (beam lines X0 and M3) over a large fluence regime (1 x 1010 - 5 x 1012 ions/cm2). Five independent techniques, namely infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy, residual gas analysis (RGA), thermal gravimetric analysis (TGA), and mass loss analysis (ML), were used to analyze the irradiated samples. FT-IR spectroscopy revealed that ion irradiation led to the decrease of characteristic band intensities showing the general degradation of the polymers, with scission of side groups and the main backbone. As a consequence of the structural modification, new bands appeared. UV-Vis transmission analysis showed an absorption edge shift from the ultraviolet region towards the visible region indicating double bond and conjugated double bond formation. On-line massspectrometric residual gas analysis showed the release of small gaseous fragment molecules. TGA analysis gave evidence of a changed thermal stability. With ML analysis, the considerable mass loss was quantified. The results of the five complementary analytical methods show how heavy ion irradiation changes the molecular structure of the polymers. Molecular degradation mechanisms are postulated. The amount of radiation damage is found to be sensitive to the used type of ionic species. While the

  19. Ion implantation induced nanotopography on titanium and bone cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Braceras, Iñigo, E-mail: inigo.braceras@tecnalia.com [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Vera, Carolina; Ayerdi-Izquierdo, Ana [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Muñoz, Roberto [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); Lorenzo, Jaione; Alvarez, Noelia [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Maeztu, Miguel Ángel de [Private Practice, P° San Francisco, 43 A-1°, 20400 Tolosa (Spain)

    2014-08-15

    Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm{sup 2}) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

  20. Ion implantation induced nanotopography on titanium and bone cell adhesion

    International Nuclear Information System (INIS)

    Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm2) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

  1. Study of the degradation process of polyimide induced by high energetic ion irradiation

    International Nuclear Information System (INIS)

    The dissertation focuses on the radiation hardness of Kapton under extreme radiation environment conditions. To study ion-beam induced modifications, Kapton foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (e.g. Ti, Mo, Au, and U) within a large fluence regime (1 x 1010-5 x 1012 ions/cm2). The irradiated Kapton foils were analysed by means of infrared and UV/Vis spectroscopy, tensile strength measurement, mass loss analysis, and dielectric relaxation spectroscopy. For testing the radiation stability of Kapton at the cryogenic operation temperature (5-10 K) of the superconducting magnets, additional irradiation experiments were performed at the Grand Accelerateur National d' Ions Lourds (GANIL, France) focusing on the online analysis of the outgassing process of small volatile degradation fragments. The investigations of the electrical properties analysed by dielectric relaxation spectroscopy exhibit a different trend: high fluence irradiations with light ions (e.g. Ti) lead to a slight increase of the conductivity, whereas heavy ions (e.g. Sm, Au) cause a drastic change already in the fluence regime of nonoverlapping tracks (5 x 1010 ions/cm2). Online analysis of the outgassing process during irradiation at cryogenic temperatures shows the release of a variety of small gaseous molecules (e.g. CO, CO2, and short hydro carbons). Also a small amount of large polymer fragments is identified. The results allow the following conclusions which are of special interest for the application of Kapton as insulating material in a high-energetic particle radiation environment. a) The material degradation measured with the optical spectroscopy and tensile strength tests are scalable with the dose deposited by the ions. The high correlation of the results allows the prediction of the mechanical degradation with the simple and non-destructive infrared spectroscopy. The degradation curve points to a critical material degradation which has to be

  2. Study of the degradation process of polyimide induced by high energetic ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Severin, Daniel

    2008-09-19

    The dissertation focuses on the radiation hardness of Kapton under extreme radiation environment conditions. To study ion-beam induced modifications, Kapton foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (e.g. Ti, Mo, Au, and U) within a large fluence regime (1 x 10{sup 10}-5 x 10{sup 12} ions/cm{sup 2}). The irradiated Kapton foils were analysed by means of infrared and UV/Vis spectroscopy, tensile strength measurement, mass loss analysis, and dielectric relaxation spectroscopy. For testing the radiation stability of Kapton at the cryogenic operation temperature (5-10 K) of the superconducting magnets, additional irradiation experiments were performed at the Grand Accelerateur National d' Ions Lourds (GANIL, France) focusing on the online analysis of the outgassing process of small volatile degradation fragments. The investigations of the electrical properties analysed by dielectric relaxation spectroscopy exhibit a different trend: high fluence irradiations with light ions (e.g. Ti) lead to a slight increase of the conductivity, whereas heavy ions (e.g. Sm, Au) cause a drastic change already in the fluence regime of nonoverlapping tracks (5 x 10{sup 10} ions/cm{sup 2}). Online analysis of the outgassing process during irradiation at cryogenic temperatures shows the release of a variety of small gaseous molecules (e.g. CO, CO{sub 2}, and short hydro carbons). Also a small amount of large polymer fragments is identified. The results allow the following conclusions which are of special interest for the application of Kapton as insulating material in a high-energetic particle radiation environment. a) The material degradation measured with the optical spectroscopy and tensile strength tests are scalable with the dose deposited by the ions. The high correlation of the results allows the prediction of the mechanical degradation with the simple and non-destructive infrared spectroscopy. The degradation curve points to a

  3. Microarray Analysis of Human Liver Cells irradiated by 80MeV/u Carbon Ions

    Science.gov (United States)

    Wang, Xiao; Tian, Xiaoling; Kong, Fuquan; Li, Qiang; Jin, Xiaodong; Dai, Zhongying; Zhang, Hong; Yang, Mingjian; Zhao, Kui

    Objective Biological effect of heavy ion beam has the important significance for cancer therapy and space exploring owing its high LET and RBE, low OER, especially forming Bragg spike at the end of the tracks of charged particles. More serious damage for cells are induced by heavy ions and difficult repair than other irradiation such as X-ray and ν-ray . To explore the molecular mechanism of biological effect caused by heavy ionizing radiation (HIR) and to construct the gene expression profile database of HIR-induced human liver cells L02 by microarray analysis. Methods In this study, L02 cells were irradiated by 80MeV/u carbon ions at 5 Gy delivered by HIRFL (Heavy Ion Research Facility in Lanzhou) at room temperature. Total RNAs of cells incubated 6 hours and 24hours after irradiation were extracted with Trizol. Unirradiated cells were used as a control. RNAs were transcripted into cDNA by reverse transcription and labelled with cy5-dCTP and cy3-dCTP respectively. A human genome oligonucleotide set consisting of 5 amino acid-modified 70-mer probes and representing 21,329 well-characterized Homo sapiens genes was selected for microarray analysis and printed on amino-silaned glass slides. Arrays were fabricated using an OmniGrid microarrayer. Only genes whose alteration tendency was consistent in both microarrays were selected as differentially expressed genes. The Affymetrix's short oligonucleotide (25-mer) HG U133A 2.0 array analyses were performed per the manufacturer's instructions. Results Of the 21,329 genes tested, 37 genes showed changes in expression level with ratio higher than 2.0 and lower than 0.5 at 6hrs after irradiation. There were 19 genes showing up-regulation in radiated L02 cells, whereas 18 genes showing down-regulation; At 24hrs after irradiation, 269 genes showed changes in expression level with ratio higher than 2.0 and lower than 0.5. There were 67 genes showing up-regulation in radiated L02 cells, whereas 202 genes showing down

  4. Calculation of stopping power ratios for carbon ion dosimetry

    Science.gov (United States)

    Geithner, Oksana; Andreo, P.; Sobolevsky, N.; Hartmann, G.; Jäkel, O.

    2006-05-01

    Water-to-air stopping power ratio calculations for the ionization chamber dosimetry of clinical carbon ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used, which is a newly developed version where substantial modifications were implemented on its predecessor SHIELD-HIT v1 (Gudowska et al 2004 Phys. Med. Biol. 49 1933-58). The code was completely rewritten replacing formerly used single precision variables with double precision variables. The lowest particle transport specific energy was decreased from 1 MeV/u down to 10 keV/u by modifying the Bethe-Bloch formula, thus widening its range for medical dosimetry applications. In addition, the code includes optionally MSTAR and ICRU-73 stopping power data. The fragmentation model was verified and its parameters were also adjusted. The present code version shows excellent agreement with experimental data. It has been used to compute the physical quantities needed for the calculation of stopping power ratios, swater,air, of carbon beams. Compared with the recommended constant value given in the IAEA Code of Practice, the differences found in the present investigations varied between 0.5% and 1% at the plateau region, respectively for 400 MeV/u and 50 MeV/u beams, and up to 2.3% in the vicinity of the Bragg peak for 50 MeV/u.

  5. Primary result of application of carbon ion beam and gamma ray for rice breeding improvement

    International Nuclear Information System (INIS)

    Recently, Carbon ion beam have been recently attracted as mutagens. A characteristic feature of ion beams is their ability to deposit high energy on a target, densely and locally, as opposed to low linear energy transfer radiation such as gamma rays and X rays. In Vietnam, application of carbon ion beam just starting through cooperation FNCA between Japan and ASEAN countries from 2009. In this report, we want to report primary result of application carbon ion beam and gamma ray for rice breeding improvement of Khang dan 18. Through primary experimental for optimum dose for carbon ion beam we found that the dose of 40 and 60 Gy was suitable for Khang dan variety treatment. Based on optimum dose 40 and 60 Gy of carbon ion beam and 150 and 200 Gy of gamma ray we irradiated for Khang dan variety. The higher dose, the lower seed set ratio were determined both ion beam and gamma ray. Especial in carbon ion beam experiment at the dose of 60 Gy was 39.18% in small experiment and more than 20% seed set ratio at the real experiment. At M4 generation, in the experiment with carbon ion beam at the dose of 60 Gy we received mutant which increase the weight of 1000 seeds (23.0 g) compare to the control 19.7 g meanwhile experiment with gamma ray at the dose of 200 Gy we received some mutant not much change in the seed weight. This may show that carbon ion beam more effective than gamma ray in term of change some characteristics of rice. (author)

  6. Evaluation of beam delivery and ripple filter design for non-isocentric proton and carbon ion therapy

    Science.gov (United States)

    Grevillot, L.; Stock, M.; Vatnitsky, S.

    2015-10-01

    This study aims at selecting and evaluating a ripple filter design compatible with non-isocentric proton and carbon ion scanning beam treatment delivery for a compact nozzle. The use of non-isocentric treatments when the patient is shifted as close as possible towards the nozzle exit allows for a reduction in the air gap and thus an improvement in the quality of scanning proton beam treatment delivery. Reducing the air gap is less important for scanning carbon ions, but ripple filters are still necessary for scanning carbon ion beams to reduce the number of energy steps required to deliver homogeneous SOBP. The proper selection of ripple filters also allows a reduction in the possible transverse and depth-dose inhomogeneities that could appear in non-isocentric conditions in particular. A thorough review of existing ripple filter designs over the past 16 years is performed and a design for non-isocentric treatment delivery is presented. A unique ripple filter quality index (QIRiFi) independent of the particle type and energy and representative of the ratio between energy modulation and induced scattering is proposed. The Bragg peak width evaluated at the 80% dose level (BPW80) is proposed to relate the energy modulation of the delivered Bragg peaks and the energy layer step size allowing the production of homogeneous SOBP. Gate/Geant4 Monte Carlo simulations have been validated for carbon ion and ripple filter simulations based on measurements performed at CNAO and subsequently used for a detailed analysis of the proposed ripple filter design. A combination of two ripple filters in a series has been validated for non-isocentric delivery and did not show significant transverse and depth-dose inhomogeneities. Non-isocentric conditions allow a significant reduction in the spot size at the patient entrance (up to 350% and 200% for protons and carbon ions with range shifter, respectively), and therefore in the lateral penumbra in the patients.

  7. Evaluation of beam delivery and ripple filter design for non-isocentric proton and carbon ion therapy

    International Nuclear Information System (INIS)

    This study aims at selecting and evaluating a ripple filter design compatible with non-isocentric proton and carbon ion scanning beam treatment delivery for a compact nozzle. The use of non-isocentric treatments when the patient is shifted as close as possible towards the nozzle exit allows for a reduction in the air gap and thus an improvement in the quality of scanning proton beam treatment delivery. Reducing the air gap is less important for scanning carbon ions, but ripple filters are still necessary for scanning carbon ion beams to reduce the number of energy steps required to deliver homogeneous SOBP. The proper selection of ripple filters also allows a reduction in the possible transverse and depth-dose inhomogeneities that could appear in non-isocentric conditions in particular.A thorough review of existing ripple filter designs over the past 16 years is performed and a design for non-isocentric treatment delivery is presented. A unique ripple filter quality index (QIRiFi) independent of the particle type and energy and representative of the ratio between energy modulation and induced scattering is proposed. The Bragg peak width evaluated at the 80% dose level (BPW80) is proposed to relate the energy modulation of the delivered Bragg peaks and the energy layer step size allowing the production of homogeneous SOBP. Gate/Geant4 Monte Carlo simulations have been validated for carbon ion and ripple filter simulations based on measurements performed at CNAO and subsequently used for a detailed analysis of the proposed ripple filter design.A combination of two ripple filters in a series has been validated for non-isocentric delivery and did not show significant transverse and depth-dose inhomogeneities. Non-isocentric conditions allow a significant reduction in the spot size at the patient entrance (up to 350% and 200% for protons and carbon ions with range shifter, respectively), and therefore in the lateral penumbra in the patients. (paper)

  8. Ion-induced molecular fragmentation: beyond the Coulomb explosion picture

    International Nuclear Information System (INIS)

    The fragmentation of the CO molecule by O7+ ion impact is investigated in two different energy regimes by fragment ion momentum spectroscopy. The improved resolution of the present kinetic energy release measurement together with application of a time-dependent wave packet dynamics method used in conjunction with new high-level computations of a large number of dication potential energy curves enables one to unambiguously assign each line to an excited state of the transient molecular dication produced during the collision. This is the first direct experimental evidence of the limitations of the Coulomb explosion model to reproduce the molecular fragmentation dynamics induced by ion impact. Electron removal due to a capture process is shown to transfer less excitation to the target than direct ionization. At low collision velocity, the three-body interaction between the projectile and the two fragments is also clearly highlighted. (author). Letter-to-the-editor

  9. Wavelength Tunability of Ion-Bombardment-Induced Ripples on Sapphire

    International Nuclear Information System (INIS)

    A study of ripple formation on sapphire surfaces by 300-2000 eV Ar+ ion bombardment is presented. Surface characterization by in-situ synchrotron grazing incidence small angle x-ray scattering and ex-situ atomic force microscopy is performed in order to study the wavelength of ripples formed on sapphire (0001) surfaces. We find that the wavelength can be varied over a remarkably wide range -- nearly two orders of magnitude -- by changing the ion incidence angle. Within the linear theory regime, the ion induced viscous flow smoothing mechanism explains the general trends of the ripple wavelength at low temperature and incidence angles larger than 30o. In this model, relaxation is confined to a few nm thick damaged surface layer. The behavior at high temperature suggests relaxation by surface diffusion. However, strong smoothing is inferred from the observed ripple wavelength near normal incidence, which is not consistent with either surface diffusion or viscous flow relaxation

  10. Wavelength tunability of ion-bombardment-induced ripples on sapphire

    International Nuclear Information System (INIS)

    A study of ripple formation on sapphire surfaces by 300-2000 eV Ar+ ion bombardment is presented. Surface characterization by in-situ synchrotron grazing incidence small angle x-ray scattering and ex-situ atomic force microscopy is performed in order to study the wavelength of ripples formed on sapphire (0001) surfaces. We find that the wavelength can be varied over a remarkably wide range--nearly two orders of magnitude--by changing the ion incidence angle. Within the linear theory regime, the ion induced viscous flow smoothing mechanism explains the general trends of the ripple wavelength at low temperature and incidence angles larger than 30 deg. . In this model, relaxation is confined to a few nm thick damaged surface layer. The behavior at high temperature suggests relaxation by surface diffusion. However, strong smoothing is inferred from the observed ripple wavelength near normal incidence, which is not consistent with either surface diffusion or viscous flow relaxation

  11. Focused Ion Beam Induced Effects on MOS Transistor Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Abramo, Marsha T.; Antoniou, Nicholas; Campbell, Ann N.; Fleetwood, Daniel M.; Hembree, Charles E.; Jessing, Jeffrey R.; Soden, Jerry M.; Swanson, Scot E.; Tangyunyong, Paiboon; Vanderlinde, William E.

    1999-07-28

    We report on recent studies of the effects of 50 keV focused ion beam (FIB) exposure on MOS transistors. We demonstrate that the changes in value of transistor parameters (such as threshold voltage, V{sub t}) are essentially the same for exposure to a Ga+ ion beam at 30 and 50 keV under the same exposure conditions. We characterize the effects of FIB exposure on test transistors fabricated in both 0.5 {micro}m and 0.225 {micro}m technologies from two different vendors. We report on the effectiveness of overlying metal layers in screening MOS transistors from FIB-induced damage and examine the importance of ion dose rate and the physical dimensions of the exposed area.

  12. Carbon ion radiotherapy with epidermal growth factor receptor (EGFR) inhibitor for refractory gastrointestinal carcinomas in mice

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate the combined effect of carbon ion radiotherapy with epidermal growth factor receptor (EGFR) inhibitor on refractory gastrointestinal carcinomas in mice. As a preliminary experiment, we assessed the sensitization effect of gemcitabine (GEM) on carbon ion radiotherapy for tumor cells and the normal tissues by using SCCVII of C3H mice. Tumor cells treated with low linear energy transfer (LET) carbon ion irradiation showed the sensitizing effect of GEM. However, no sensitizating effect was shown for the normal tissue irradiated with either low LET or with high LET. (author)

  13. Low temperature ripple formation: Ion-induced effective surface diffusion in ion sputtering

    International Nuclear Information System (INIS)

    Surfaces bombarded with energetic ions may develop a rough or a ripple surface morphology. The ripple formation has been successfully described by the instability caused by preferential erosion, the ripple wavelength being determined by the competition between surface erosion and thermally activated diffusion. However, as recent experiments and computer simulations have shown, ripple formation takes place even at the low temperatures, when thermally activated processes are suppressed. In this paper the authors propose a theory to explain low-temperature ripple formation based on the ion-induced effective surface diffusion

  14. Ion beam deposition of amorphous carbon films with diamond like properties

    Science.gov (United States)

    Angus, John C.; Mirtich, Michael J.; Wintucky, Edwin G.

    1982-01-01

    Carbon films were deposited on silicon, quartz, and potassium bromide substrates from an ion beam. Growth rates were approximately 0.3 micron/hour. The films were featureless and amorphous and contained only carbon and hydrogen in significant amounts. The density and carbon/hydrogen ratio indicate the film is a hydrogen deficient polymer. One possible structure, consistent with the data, is a random network of methylene linkages and tetrahedrally coordinated carbon atoms.

  15. The role of ammonia in sulfuric acid ion induced nucleation

    Directory of Open Access Journals (Sweden)

    I. K. Ortega

    2008-06-01

    Full Text Available We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good accuracy-to-computational effort ratio. We have applied this strategy to evaluate the relevance of ternary ion induced nucleation; we have also performed calculations for neutral ternary nucleation for comparison. The results for neutral ternary nucleation agree with previous results, and confirm the important role of ammonia in enhancing the growth of sulfuric acid clusters. On the other hand, we have found that ammonia does not enhance the growth of ionic sulfuric acid clusters. The results also confirm that ion-induced nucleation is a barrierless process at high altitudes, but at ground level there exists a barrier due to the presence of a local minimum on the free energy surface.

  16. Ion beam induced charge and numerical modeling study of novel detector devices for single ion implantation

    International Nuclear Information System (INIS)

    In the near future devices which are fabricated from shallow arrays of few and single atoms will exploit quantum mechanical rules to perform useful functions including quantum computation. Fabrication of these devices presents formidable technological challenges. We have developed a single ion implantation system that is capable of verifiable fabrication of single donor devices using 14 keV 31P ions implanted into ultra-pure, high resistivity silicon substrates based on the technique of Ion Beam Induced Charge (IBIC). A detection system with integrated detector electrodes registers the charge transient from a single ion impact which is used to signal the implantation of an ion into the substrate. We describe here the use of IBIC with MeV ions to study the charge collection efficiency of the detector electrodes. By using three dimensional numerical technology computer-aided design (TCAD) models for the decrease in the IBIC signal as a function of distance from the detector electrode, we can obtain an accurate measurement of the resistivity of the silicon substrate, allowing confirmation of the values specified by the supplier, and providing us with confidence in the numerical models used by TCAD for simulation. This technique has advantages over resistivity measurements by four-point probes because it is spatially resolved, probes through the intact oxide, and can be done without making contact to the device in the area of the probe

  17. Residual activity induced by ion bombardment on insulating samples

    International Nuclear Information System (INIS)

    In this work we investigate some properties of the residual activity induced by protons impinging on quartz, mylar and other insulating materials. In particular, we discuss the time constant related to the decay of the emitted radiation after the primary ion beam is turned off. This radiation includes a continuum of bremsstrahlung and, in some cases, characteristic X-rays induced in the process as well. In general, the results indicate the presence of two time constants in the decaying process. Moreover, it appears that the residual activity has a strong dependence on the material specifications and on the conditions of the surface under bombardment. A simple mechanism for this process is suggested

  18. Behavior of the extraction of metallic ions in carbonate medium, using N-benzoylphenylhydroxylamine (BPHA) - benzene

    International Nuclear Information System (INIS)

    The possibility of separating quantitatively trace impurities like Cu, Fe, In and Pb, present in uranium base materials of nuclear grade, is demonstrated. A solvent extraction is employed which makes use of -benzoylphenylhydroxylamine(BPHA)-benzene solution and separation is effected in a medium containing 252 moles per liter of sodium-uranyl tricarbonate at pH of 9,0. Carbonate ions under such conditions inhibit uranium extraction by masking uranyl ion-BPHA reaction. The uranyl ions show a demasking action, releasing, thereby, Pb(II) ions which are being extracted from carbonate medium. The Atomic Absorption Spectrophometry technique is used to obtain the experimental data

  19. Ion-Induced Surface Modification of Magnetically Operated Contacts

    Directory of Open Access Journals (Sweden)

    Karen Arushanov

    2012-02-01

    Full Text Available A study has been made of permalloy (iron-nickel contacts of reed switches before and after ion-induced surface modification using atomic force and optical microscopy, Auger electron and X-ray photoelectron spectroscopy. It has been found that the formation of surface nitride layers enhances corrosion and erosion resistance of contacts. We proposed to produce such layers directly into sealed reed switches by means of pulsing glow-discharge nitrogen plasma.

  20. Ion-Induced Surface Modification of Magnetically Operated Contacts

    OpenAIRE

    Karen Arushanov; Igor Zeltser; Sergey Karabanov; Rafail Maizels; Evgeny Moos; Alexander Tolstoguzov

    2012-01-01

    A study has been made of permalloy (iron-nickel) contacts of reed switches before and after ion-induced surface modification using atomic force and optical microscopy, Auger electron and X-ray photoelectron spectroscopy. It has been found that the formation of surface nitride layers enhances corrosion and erosion resistance of contacts. We proposed to produce such layers directly into sealed reed switches by means of pulsing glow-discharge nitrogen plasma.

  1. Heavy ion induced failures in a power IGBT

    International Nuclear Information System (INIS)

    Power semiconductor devices are going through a rapid evolution. Modern components, such as Insulated Gate Bipolar Transistors (IGBT), have become widely accepted as well-suited devices for many power electronic applications. Here, heavy-ion induced destructive failures are reported in N-channel power IGBTs. For the first time, an experimental and 2D simulation investigation shows that latchup is involved in the triggering of the device

  2. Modification of tribomechanical properties of commercial TiN coatings by carbon ion implantation

    International Nuclear Information System (INIS)

    Physical vapour deposited commercial TiN coatings of about 2μm thickness on high speed steel substrates were implanted at room temperature with 95keV carbon ions at nominal doses between 1x1017 and 8x1017ionscm-2. An ultra-microhardness apparatus (UMIS-2000) was used to measure hardness, and a pin-on-disc machine (CSEM tribometer) with a sapphire ball was used to measure wear, friction and adhesion. Carbon implantation induced a significant improvement in ultra-microhardness, friction coefficient and wear properties. The surface microhardness increases monotonically by up to 115% until a critical dose φcrit is reached. Beyond this dose the hardness decreases, but remains higher than that of unimplanted sample. A lower friction coefficient and a longer transition period towards a steady state condition were obtained by implantation. Proton elastic scattering (PES) measurements show loss of nitrogen after implantation by up to 27%. Rutherford backscattering (RBS) analysis indicated that some implanted carbon has diffused out from the implanted region towards the TiN surface. The changes in tribomechanical properties are discussed in terms of radiation damage and possible second phase formation. ((orig.))

  3. Modeling Diffusion Induced Stresses for Lithium-Ion Battery Materials

    Science.gov (United States)

    Chiu Huang, Cheng-Kai

    Advancing lithium-ion battery technology is of paramount importance for satisfying the energy storage needs in the U.S., especially for the application in the electric vehicle industry. To provide a better acceleration for electric vehicles, a fast and repeatable discharging rate is required. However, particle fractures and capacity loss have been reported under high current rate (C-rate) during charging/discharging and after a period of cycling. During charging and discharging, lithium ions extract from and intercalate into electrode materials accompanied with the volume change and phase transition between Li-rich phase and Li-poor phase. It is suggested that the diffusion-induced-stress is one of the main reasons causing capacity loss due to the mechanical degradation of electrode particles. Therefore, there is a fundamental need to provide a mechanistic understanding by considering the structure-mechanics-property interactions in lithium-ion battery materials. Among many cathode materials, the olivine-based lithium-iron-phosphate (LiFePO4) with an orthorhombic crystal structure is one of the promising cathode materials for the application in electric vehicles. In this research we first use a multiphysic approach to investigate the stress evolution, especially on the phase boundary during lithiation in single LiFePO4 particles. A diffusion-controlled finite element model accompanied with the experimentally observed phase boundary propagation is developed via a finite element package, ANSYS, in which lithium ion concentration-dependent anisotropic material properties and volume misfits are incorporated. The stress components on the phase boundary are used to explain the Mode I, Mode II, and Mode III fracture propensities in LiFePO4 particles. The elastic strain energy evolution is also discussed to explain why a layer-by-layer lithium insertion mechanism (i.e. first-order phase transformation) is energetically preferred. Another importation issue is how current

  4. Thermal effects on the Ga+ ion beam induced structural modification of a-SiC:H

    International Nuclear Information System (INIS)

    The effects of implantation temperature and post-implantation thermal annealing on the Ga+ ion beam induced optical contrast formation in hydrogenated silicon-carbon alloy (a-SiC:H) films and underlying structural modifications have been studied. The optical contrast formed (between implanted and unimplanted regions of the film material) has been made use of in the form of optical pattern formation by computer-operated Ga+-focused ion beam. Possible applications of this effect in the area of submicron lithography and high-density optical data storage have been suggested with regard to the most widely spread focused micro-beam systems based on Ga+ liquid metal ion sources. The implanted samples were structurally analysed using vibrational spectroscopies, like Raman and infra-red (IR) spectroscopy, to define optimum implantation conditions. The precise role of implantation temperature effects, i.e. the target temperature during Ga+ ion irradiation, on the structural modification obtainable has been therefore a key part of this study. Appropriate post-implantation annealing treatments were also studied, since these are expected to offer further benefits in reducing the required ion dose and enhancing the optical contrast, thus increasing the cost-effectiveness of the method.

  5. Confinement-induced resonances in ultracold atom-ion systems

    Science.gov (United States)

    Melezhik, V. S.; Negretti, A.

    2016-08-01

    We investigate confinement-induced resonances in a system composed of a tightly trapped ion and a moving atom in a waveguide. We determine the conditions for the appearance of such resonances in a broad region—from the "long-wavelength" limit to the opposite case when the typical length scale of the atom-ion polarization potential essentially exceeds the transverse waveguide width. We find considerable dependence of the resonance position on the atomic mass which, however, disappears in the "long-wavelength and zero-energy" limit, where the known result for the confined atom-atom scattering is reproduced. We also derive an analytic and a semianalytic formula for the resonance position in the long-wavelength and zero-energy limit and we investigate numerically the dependence of the resonance condition on the finite atomic colliding energy. Our results, which can be investigated experimentally in the near future, could be used to determine the atom-ion scattering length, to determine the temperature of the atomic ensemble in the presence of an ion impurity, and to control the atom-phonon coupling in a linear ion crystal in interaction with a quasi-one-dimensional atomic quantum gas.

  6. Defect effects on THz wave emission induced by ion irradiation

    International Nuclear Information System (INIS)

    Background: As the core component of terahertz system, terahertz source determines the performance of the whole system. The THz wave emission efficiency depends decisively on the THz emitting materials which are usually made of low-temperature-grown gallium arsenide. It is found that through ion irradiation better THz wave emission material can be prepared, which overcomes the poor reproducibility of high quality material prepared by the traditional method. Purpose: In order to find out the best irradiation condition for producing the required photoconductive material, we try to clarify the mechanism of the THz wave emission induced by ion implantation. Methods: Applying Monte Carlo method, we simulated the terahertz emission under different defect conditions, and tested the emission efficiency of GaAs and InP(Fe) irradiated by N ions with the energy of 500 keV and 1.5 MeV, respectively. Results: MC simulation study shows that both capture cross-section and trap density can cause changes in terahertz pulse width and peak intensity. From the experiments conducted on ion irradiated semiconductors we found only the peak intensity changes with the irradiation fluence. Conclusion: It is proposed that intrinsic defects introduced during growth of crystals are the key defects that contribute mainly to the terahertz wave emission behavior, and defects introduced by ion irradiation may only modify the transport property of carriers through scattering in semiconductor, by which it changes the terahertz wave emission performance. (authors)

  7. Focused ion beam induced deflections of freestanding thin films

    International Nuclear Information System (INIS)

    Prominent deflections are shown to occur in freestanding silicon nitride thin membranes when exposed to a 50 keV gallium focused ion beam for ion doses between 1014 and 1017 ions/cm2. Atomic force microscope topographs were used to quantify elevations on the irradiated side and corresponding depressions of comparable magnitude on the back side, thus indicating that what at first appeared to be protrusions are actually the result of membrane deflections. The shape in high-stress silicon nitride is remarkably flat-topped and differs from that in low-stress silicon nitride. Ion beam induced biaxial compressive stress generation, which is a known deformation mechanism for other amorphous materials at higher ion energies, is hypothesized to be the origin of the deflection. A continuum mechanical model based on this assumption convincingly reproduces the profiles for both low-stress and high-stress membranes and provides a family of unusual shapes that can be created by deflection of freestanding thin films under beam irradiation

  8. Confinement-Induced Resonances in Ultracold Atom-Ion Systems

    CERN Document Server

    Melezhik, Vladimir S

    2016-01-01

    We investigate confinement-induced resonances in a system composed by a tightly trapped ion and a moving atom in a waveguide. We determine the conditions for the appearance of such resonances in a broad region -- from the "long-wavelength" limit to the opposite case when the typical length scale of the atom-ion interaction essentially exceeds the transverse waveguide width. We find considerable dependence of the resonance position on the atomic mass which, however, disappears in the "long-wavelength" limit, where the result for the confined atom-atom scattering is reproduced. We also derive an analytic formula for the resonance position in the "long-wavelength zero-energy" limit. Our results, which can be investigated in current experiments, indicate a strategy to determine the atom-ion scattering length, the temperature of the atomic ensemble in the presence of an ion impurity, and a pathway to control the atom-phonon coupling in a one dimensional ion crystal in interaction with an atomic quantum gas.

  9. Quantitative Traits of Ion Beam Induced Mutagenesis in Triticum aestivum

    Institute of Scientific and Technical Information of China (English)

    Huan FANG; Zhen JIAO

    2012-01-01

    [Objective] The aim of this study was to elucidate the quantitative traits of plants mutagenized by ion beam. [Method] The particular variation phenotypes, a- gronomic traits, and protein and wet gluten contents of progenies derived from the same ion beam induced mutant were investigated. [Result] Morphological polymor- phism existed in some individuals. Plant height, spike length and protein content were significantly influenced by ion beam, and effective tiller number and wet gluten content were moderately influenced. Multiple comparisons of all the indices within groups indicated genomic instability among these groups. Coefficient of variation im- plied the differences within group were very low. [Conclusion] Ion beam irradiation displayed characteristics of multi-directivity and non-directiveness. It aroused multiple variations in the same mutant. Instability among progeny indicates cells had different fate even in the same irradiated tissue. It may take several generations for mutants to stabilize particular phenotypes. The effects of ion beam irradiation may be the in- terrelated direct irradiation damage, indirect irradiation damage and late effect, such as bystander effect and adaptive response.

  10. A Binary Cyclic Carbonates-Based Electrolyte Containing Propylene Carbonate and Trifluoropropylene Carbonate for 5 V Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Graphical abstract: A binary cyclic carbonates-based electrolyte containing propylene carbonate and trifluoropropylene carbonate with an optimized volume ratio is successfully applied for 5 V lithium-ion batteries. Display Omitted -- Highlights: •A binary solvent electrolyte containing TFPC and PC is used for high-voltage LIBs. •Volume ratio of TFPC/PC is a crucial factor affecting the physical and electrochemical properties. •The binary solvent can maintain a stable liquid phase in a broad temperature range. •Graphite anode works well in the electrolyte of 1 mol dm−3 LiPF6-TFPC/PC (1:2). •The optimized electrolyte has good compatibility with 5 V LiNi0.5Mn1.5O4 cathode. -- Abstract: To widen the operating potential window of electrolyte used for lithium-ion batteries, a binary cyclic carbonates-based electrolyte containing propylene carbonate (PC) and trifluoropropylene carbonate (TFPC) with an optimized volume ratio has been successfully proposed. The main function of additive TFPC is to establish a stable SEI layer on graphite electrode and suppress the intercalation reaction of PC molecules. Unlike the previous works, where the TFPC/PC involved electrolyte was simply estimated at a certain volume ration and recognized as an unfavorable system, in this work, the physical properties of the electrolyte solutions with a series of volume ratios of TFPC/PC and their electrochemical performances in a graphite/Li cell and 5 V LiNi0.5Mn1.5O4/Li cell have been systematically studied. The electrolyte of 1 mol dm−3 LiPF6-TFPC/PC (1:2) is adopted as the optimized system due to its high ionic conductivity, low viscosity, broad operating potential window, wide liquid temperature range (−50 ∼ 240 °C) and suitable film-forming property. Both the graphite and LiNi0.5Mn1.5O4 electrodes were found to exhibit high reversible capacity and superb rate performance in the optimized electrolyte, making us have a new recognition of this important binary solvent

  11. Precise measurement of single carbon nanocoils using focused ion beam technique

    Science.gov (United States)

    Nakamura, Yasushi; Suda, Yoshiyuki; Kunimoto, Ryuji; Iida, Tamio; Takikawa, Hirofumi; Ue, Hitoshi; Shima, Hiroyuki

    2016-04-01

    We have developed a precise resistivity measurement system for quasi-one-dimensional nanomaterials using a focused ion beam. The system enables the resistivity of carbon nanocoils (CNCs) to be measured and its dependence on coil geometry to be elucidated. At room temperature, the resistivity of CNCs tended to increase with coil diameter, while that of artificially graphitized CNCs remained constant. These contrasting behaviors indicate coil-diameter-induced enhancement in structural disorder internal to CNCs. Low-temperature resistivity measurements performed on the CNCs revealed that electron transport through the helical axis is governed by the variable range hopping mechanism. The characteristic temperature in variable range hopping theory was found to systematically increase with coil diameter, which supports our theory that the population of sp2-domains in CNCs decreases considerably with coil diameter.

  12. Characterization of surface enhancement of carbon ion-implanted TiN coatings by metal vapor vacuum arc ion implantation

    CERN Document Server

    Chang, C L

    2002-01-01

    The modification of the surfaces of energetic carbon-implanted TiN films using metal vapor vacuum arc (MEVVA) ion implantation was investigated, by varying ion energy and dose. The microhardness, microstructure and chemical states of carbon, implanted on the surface layer of TiN films, were examined, as functions of ion energy and dose, by nanoindenter, transmission electron microscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. Results revealed that the microhardness increased from 16.8 up to 25.3 GPa and the friction coefficient decreased to approximately 0.2, depending on the implanted ion energy and dose. The result is attributed to the new microcrystalline phases of TiCN and TiC formed, and carbon concentration saturation of the implanted matrix can enhance the partial mechanical property of TiN films after MEVVA treatment. The concentration distribution, implantation depth and chemical states of carbon-implanted TiN coatings depended strongly on the ion dose and...

  13. Carbonized-leaf Membrane with Anisotropic Surfaces for Sodium-ion Battery.

    Science.gov (United States)

    Li, Hongbian; Shen, Fei; Luo, Wei; Dai, Jiaqi; Han, Xiaogang; Chen, Yanan; Yao, Yonggang; Zhu, Hongli; Fu, Kun; Hitz, Emily; Hu, Liangbing

    2016-01-27

    A simple one-step thermal pyrolysis route has been developed to prepare carbon membrane from a natural leaf. The carbonized leaf membrane possesses anisotropic surfaces and internal hierarchical porosity, exhibiting a high specific capacity of 360 mAh/g and a high initial Coulombic efficiency of 74.8% as a binder-free, current-collector-free anode for rechargeable sodium ion batteries. Moreover, large-area carbon membranes with low contact resistance are fabricated by simply stacking and carbonizing leaves, a promising strategy toward large-scale sodium-ion battery developments. PMID:26727650

  14. Induced nucleation of carbon dust in red giant stars

    Science.gov (United States)

    Cadwell, Brian J.; Wang, Hai; Feigelson, Eric D.; Frenklach, Michael

    1994-01-01

    This study quantitatively tests the proposed model of induced nucleation of carbonaceous grains in carbon-rich red giant stars. Induced nucleation is the process of grain growth initiated by the presence of reactive surfaces provided by seed particles. The numerical study was performed using a deailed chemical kinetic model of carbon deposition, grain coagulation, and homogeneous nucleation of polycyclic aromatic hydrocarbons (PAHs). The model uses a method of moments to keep track of developing grain population in the forming dust shell. We test the efficiency of grain formation for large ranges of dust shell parameters typical for carbon stars. Our model is capable of producing a range of optically thick and thin dust shells in carbon stars. Results are in accord with (IRAS) spectral classes of carbon stars. The resulting composite grains produced are consistent with those recently found in ancient meteorites. This model also provides a realistic explanation for high abundances of (PAHs) in the interstellar medium and some planetary nebulae.

  15. Protons from carbon ion fragmentation at 0.3–2.0 GeV/nucleon: Comparison with models of ion-ion interactions

    International Nuclear Information System (INIS)

    Yields of protons at 3.5° from carbon ion fragmentation at energies of T0 = 0.3, 0.6, 0.95, and 2.0 GeV/nucleon on a Be target were measured in the FRAGM experiment at TWA-ITEP heavy-ion facility. Proton momentum spectra cover both the region of the fragmentation maximum and the cumulative region. The differential cross sections span six orders of its magnitude. The spectra are compared with the predictions of four models of ion-ion interactions: LAQGSM03.03, SHIELD-HIT, QMD, and BC

  16. Cellular and molecular analyses of hprt mutation in human hepatocyte L02 cells after exposure to carbon ions

    Science.gov (United States)

    Li, Qiang; He, Jing; Jin, Xiao-Dong; Gong, Li; Li, Sha

    Mutations play an important role in carcinogenesis. The quantitative evaluation of mutation induction by heavy charged particles helps us to delineate the risks of space radiation on astronauts, as well as the risks of heavy ions on patients during tumor therapy. Hprt mutation assay, which has been used as a biological dosimeter, is an ideal gene mutation test in mammalian cells in vitro. In order to provide basic data and evidence for the risk assessment of heavy ions, the relationships between hprt mutation induction and radiation dose in human hepatocyte L02 cells were investigated for highand low-LET carbon ions and X-rays. Moreover, the carbon ion induced hprt mutation spectrum was analyzed. In our study, human hepatocyte L02 cells were irradiated with carbon ions with LET of 30keV/µm and X-rays (0.2keV/µm), respectively. The survival fraction of L02 cells was measured by means of colony-forming assay. The mutation frequency was detected by measuring 6-thioguanine-resistant clones after 10 days of incubation at the presence of 15mg/L 6-TG. To obtain the mutation spectrum, 9 10 mutant cell clones at each dose were randomly selected from the 6-TG containing medium, and were further cultured and analyzed. The deletion patterns of the 9 exons of hprt gene were analyzed with multiplex polymerase chain reactions (multiplex PCR). Our results show that the number of mutants per 106 surviving cells increased with increasing the radiation dose for both the irradiations, and the mutation frequency increased up to 1Gy while reduced with increasing dose further. Partial deletion was the most dominant deletion pattern in the hprt mutant cells, and with the increase of dose, hprt genes tended to have more total deletions and less point deletions. It can be inferred that human hepatocyte L02 cells are more radiosensitive to high-LET carbon ions than to low-LET X-rays, and carbon ions are more effective in inducing hprt mutation in L02 cells. It has been also found that the

  17. Irradiation-induced structure and property changes in tokamak plasma-facing, carbon-carbon composites

    International Nuclear Information System (INIS)

    Carbon-carbon composites are an attractive choice for fusion reactor plasma-facing components because of their low atomic number, superior thermal shock resistance, and low neutron activation. Next generation plasma fusion reactors, such as the International Thermonuclear Experimental Reactor (ITER), will require advanced carbon-carbon composite materials possessing high thermal conductivity to manage the anticipated severe heat loads. Moreover, ignition machines such as ITER will produce large neutron fluxes. Consequently, the influence of neutron damage on the structure and properties of carbon-carbon composite materials must be evaluated. Data from two irradiation experiments are reported and discussed here. Carbon-carbon composite materials were irradiated in target capsules in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). A peak damage dose of 4.7 displacements per atom (dpa) at 600 degree C was attained. The carbon materials irradiated included uni-directional, two-directional, and three-directional carbon-carbon composites. Dimensional changes are reported for the composite materials and are related to single crystal dimensional changes through fiber and composite structural models. Moreover, the irradiation-induced dimensional changes are reported and discussed in terms of their architecture, fiber type, and graphitization temperature. The effect of neutron irradiation on thermal conductivity of two three-directional, carbon-carbon composites is reported and the recovery of thermal conductivity due to thermal annealing is discussed

  18. The mechanism of DNA double strand break repair induced by heavy ion radiation

    International Nuclear Information System (INIS)

    In order to understand the unique molecular characteristics associated with DNA double strand break (DSB) repair in cells irradiated with high linear energy transfer (LET) heavy ion radiation, we have studied phosphorylation status of DNA-PKcs at Thr 2609 in human cells with various ATM status. After high LET carbon ion irradiation, this threonine site was not well phosphorylated in cells with ATM inhibitor, while the phosphorylation was always observed in cells exposed to X-rays irrespective of ATM status; this was demonstrated both by immune-staining and Western blotting. Another important finding is that ATM seems to play a precious role in complex DNA damage such as one induced by high LET irradiation; this kind of ATM property has only been shown with low LET radiation. (author)

  19. Molecular dynamics study of accelerated ion-induced shock waves in biological media

    CERN Document Server

    de Vera, Pablo; Currell, Fred J; Solov'yov, Andrey V

    2016-01-01

    We present a molecular dynamics study of the effects of carbon- and iron-ion induced shock waves in DNA duplexes in liquid water. We use the CHARMM force field implemented within the MBN Explorer simulation package to optimize and equilibrate DNA duplexes in liquid water boxes of different sizes and shapes. The translational and vibrational degrees of freedom of water molecules are excited according to the energy deposited by the ions and the subsequent shock waves in liquid water are simulated. The pressure waves generated are studied and compared with an analytical hydrodynamics model which serves as a benchmark for evaluating the suitability of the simulation boxes. The energy deposition in the DNA backbone bonds is also monitored as an estimation of biological damage, something which lies beyond the possibilities of the analytical model.

  20. Role of Hypoxia-inducible factor-1 and its target genes in human lung adenocarcinoma cells after photon- versus carbon ion irradiation; Expression HIF-1-abhaengiger Gene in humanen Lungenadenokarzinom (A549)-Zellen und deren Regulation nach Photonen- und Schwerionenbestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Bill, Verena Maria

    2013-11-26

    Exposed to hypoxia tumor cells are notably resistant to photon irradiation. The hypoxiainducible transcription factor 1α (HIF-1α) seems to play a fundamental role in this resistance, while its role after heavy-ion beam remains unknown. The intention of this study was to determine how A549-cells (non-small-cell lung carcinoma) react in different oxygenation states after irradiation with photons or heavy ions, particularly in regards to their expression of HIF-1 target genes. Resistance of hypoxic A549 cells after photon irradiation was documented by cellular and clonogenic survival. In contrast, cellular survival after heavy-ion irradiation in hypoxic cells was not elevated to normoxic cells. Among the oxygen dependent regulation of HIF-1 target genes, gene expression analyses showed an increased expression of GLUT-1, LDH-A, PDK-1 and VEGF after photon irradiation but not after heavy-ion irradiation after 48 hours in normoxic cells. As expected, CDKN1A as inhibitor of cell cycle progression showed higher expression after both radiation forms; interestingly CDKN1A was also in an oxygen dependent manner lightly upregulated. In western blot analyses we demonstrated a significant increase of HIF-1 and GLUT-1 caused by hypoxia, but only a tendency of increased protein level in hypoxia after photon irradiation and no changes after heavy-ion irradiation. Significantly higher protein level of secreted VEGF-A could be measured 72 hours after photon irradiation in normoxic cells by ELISA analyses. Controversially discussed, I could not detect an association between HIF-1 and SCF or Trx-1 in A549-cells in this study. Whereas Trx-1-expression was neither influenced by changed oxygen partial pressure nor irradiation, I could show increased SCF mRNA by quantitative Real Time-PCR and secreted protein level by ELISA after photon irradiation independent of oxygen state. In summary, this study showed that HIF-1 and its target genes (GLUT-1, LDHA; PDK, VEGF) and also SCF was

  1. Erosion-induced massive organic carbon burial and carbon emission in the Yellow River basin, China

    OpenAIRE

    Ran, L.; X. X. Lu; Z. Xin

    2013-01-01

    Soil erosion and terrestrial deposition of soil organic carbon (SOC) can potentially play a significant role in global carbon cycling. Assessing the fate of SOC during erosion and subsequent transport and sedimentation is of critical importance. Using hydrological records of soil erosion and sediment load, and compiled organic carbon (OC) data, budgets of the eroded soils and OC induced by water in the Yellow River basin during 1950–2010 were analyzed. The Yellow River basin has experi...

  2. Carbon Ion Irradiation Inhibits Glioma Cell Migration Through Downregulation of Integrin Expression

    International Nuclear Information System (INIS)

    Purpose: To investigate the effect of carbon ion irradiation on glioma cell migration. Methods and Materials: U87 and Ln229 glioma cells were irradiated with photons and carbon ions. Migration was analyzed 24 h after irradiation. Fluorescence-activated cell sorting analysis was performed in order to quantify surface expression of integrins. Results: Single photon doses of 2 Gy and 10 Gy enhanced ανβ3 and ανβ5 integrin expression and caused tumor cell hypermigration on both vitronectin (Vn) and fibronectin (Fn). Compared to integrin expression in unirradiated cells, carbon ion irradiation caused decreased integrin expression and inhibited cell migration on both Vn and Fn. Conclusion: Photon radiotherapy (RT) enhances the risk of tumor cell migration and subsequently promotes locoregional spread via photon induction of integrin expression. In contrast to photon RT, carbon ion RT causes decreased integrin expression and suppresses glioma cell migration on both Vn and Fn, thus promising improved local control.

  3. Clinical results of carbon ion radiotherapy for bone and soft tissue tumors

    International Nuclear Information System (INIS)

    First choice of treatment for bone and soft tissue tumors is surgical tumor resection, but some cases have difficulties to resect radically because of tumor size, location, or their reduction in QOL after surgery. Carbon ion radiotherapy has been reported that have both good local tumor control and high QOL for patients with bone and soft tissue tumors, especially sacral chordoma and unresectable osteosarcoma of the tract. Some articles of the results with carbon ion radiotherapy for sacral chordoma show better local control and QOL than that of surgery. Moreover, several reports show good local control and preservation of QOL for patients with unresectable osteosarcoma of the tract, retroperitoneal sarcoma, and other situations of sarcomas. Now carbon ion radiotherapy can offer a promising alternative to surgery for patients with unresectable sarcomas. We will discuss about the results of carbon ion radiotherapy for bone and soft tissue tumors in this issue. (author)

  4. Thermal property tuning in aligned carbon nanotube films and random entangled carbon nanotube films by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Chen, Di; Wang, Xuemei [Department of Nuclear Engineering, Texas A& M University, College Station, Texas 77843 (United States); Bykova, Julia S.; Zakhidov, Anvar A. [The Alan G. MacDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75080 (United States); Shao, Lin, E-mail: lshao@tamu.edu [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Department of Nuclear Engineering, Texas A& M University, College Station, Texas 77843 (United States)

    2015-10-12

    Ion irradiation effects on thermal property changes are compared between aligned carbon nanotube (A-CNT) films and randomly entangled carbon nanotube (R-CNT) films. After H, C, and Fe ion irradiation, a focusing ion beam with sub-mm diameter is used as a heating source, and an infrared signal is recorded to extract thermal conductivity. Ion irradiation decreases thermal conductivity of A-CNT films, but increases that of R-CNT films. We explain the opposite trends by the fact that neighboring CNT bundles are loosely bonded in A-CNT films, which makes it difficult to create inter-tube linkage/bonding upon ion irradiation. In a comparison, in R-CNT films, which have dense tube networking, carbon displacements are easily trapped between touching tubes and act as inter-tube linkage to promote off-axial phonon transport. The enhancement overcomes the phonon transport loss due to phonon-defect scattering along the axial direction. A model is established to explain the dependence of thermal conductivity changes on ion irradiation parameters including ion species, energies, and current.

  5. Thermal property tuning in aligned carbon nanotube films and random entangled carbon nanotube films by ion irradiation

    International Nuclear Information System (INIS)

    Ion irradiation effects on thermal property changes are compared between aligned carbon nanotube (A-CNT) films and randomly entangled carbon nanotube (R-CNT) films. After H, C, and Fe ion irradiation, a focusing ion beam with sub-mm diameter is used as a heating source, and an infrared signal is recorded to extract thermal conductivity. Ion irradiation decreases thermal conductivity of A-CNT films, but increases that of R-CNT films. We explain the opposite trends by the fact that neighboring CNT bundles are loosely bonded in A-CNT films, which makes it difficult to create inter-tube linkage/bonding upon ion irradiation. In a comparison, in R-CNT films, which have dense tube networking, carbon displacements are easily trapped between touching tubes and act as inter-tube linkage to promote off-axial phonon transport. The enhancement overcomes the phonon transport loss due to phonon-defect scattering along the axial direction. A model is established to explain the dependence of thermal conductivity changes on ion irradiation parameters including ion species, energies, and current

  6. Electrical resistance of diamond implanted at liquid nitrogen temperature with carbon ions

    International Nuclear Information System (INIS)

    Carbon ion implantation of diamond to high fluence, below the temperature at which diamond growth can occur, usually leads to black layers of high conductivity. This study shows that for a low enough temperature of the diamond during implantation, a black layer with high electrical resistance can develop. In particular, carbon ion implantation at liquid nitrogen temperature, leads to an implanted layer with electrical resistance about one million times higher than the resistance obtained for implantation at temperatures above room temperature. (author)

  7. Feasibility of carbon ion radiotherapy for locally advanced sinonasal adenocarcinoma

    International Nuclear Information System (INIS)

    Background and purpose: To evaluate the safety and efficacy of carbon ion radiotherapy (CIRT) for locally advanced sinonasal adenocarcinoma. Material and methods: Twenty-two patients with sinonasal adenocarcinoma were treated with CIRT. CIRT was the primary treatment for 16 patients. Four patients received CIRT for local recurrence after surgery and two for residual tumour after surgery or chemotherapy. At the start of CIRT, 1 patient had T-classification (T) 2 disease, 2 had T3 disease, 5 had T4a disease, and 14 had T4b disease. Fourteen patients were treated with 57.6 Gy equivalent (GyE)/16 fractions, and 8, with 64.0 GyE/16 fractions. Results: The median follow-up period was 43 months for all patients. The 3-year local control and loco-regional control rates for all patients were 76.9% (95% confidence interval [CI] = 56.7–97.1%) and 61.3% (95% CI = 38.5–84.1%), respectively. The 3-year overall survival and disease-specific survival rates were 59.1% (95% CI = 38.6–79.6%) and 65.6% (95% CI = 44.9–86.3%), respectively. Acute reactions of grade 3 of the skin and mucosa were observed in 2 and 4 patients, respectively. Late reactions included lateral visual loss (5 patients), mucosal ulceration (1 patient), and brain necrosis with clinical symptoms (1 patient). In the 5 patients who developed visual loss, the optic nerve was close to the tumour. Conclusions: CIRT was effective and generally safe for locally advanced sinonasal adenocarcinoma

  8. Induction and repair of DNA-DSB induced by heavy ions under hypoxic conditions

    International Nuclear Information System (INIS)

    We have studied three different end points such as induction of double strand breaks (DSB), unrejoined DSB and cell killing after irradiation with heavy ions (approximately 13-440 keV/μm) in cultured mammalian cells under oxic and hypoxic conditions. DSB were detected by the static field gel electrophoresis assay. The RBE for induction of DSB under oxic condition decreased with increasing linear energy transfer (LET), but that under hypoxic increased. On the other hand, the relative biological effectiveness (RBEs) for unrejoined DSB under both conditions increased with increasing LET, reaching a maximum RBE at around 200 keV/μm; this coincide with the LET-RBE spectra for cell killing. SCCVII cells were transplanted into the hind legs of C3H mice. The tumors were irradiated with carbon ions at the distal position of spread-out Bragg peak (SOBP) (∼80 keV/μm), either hypoxic or oxic. In addition, single-cell suspensions prepared by enzymatically digesting tumors were irradiated under oxic in vitro. The oxygen enhancement ratio (OER) using non-clamped tumors was 1.56, while that using single-cell suspensions was 1.94. We find that an acute hypoxic inducible radioresistance exists in tumor irradiated with high LET carbon ions. (author)

  9. Peripheral nerve regeneration through a silicone chamber implanted with negative carbon ions: Possibility to clinical application

    Science.gov (United States)

    Ikeguchi, Ryosuke; Kakinoki, Ryosuke; Tsuji, Hiroshi; Yasuda, Tadashi; Matsuda, Shuichi

    2014-08-01

    We investigated whether a tube with its inner surface implanted with negative-charged carbon ions (C- ions) would enable axons to extend over a distance greater than 10 mm. The tube was found to support nerves regenerating across a 15-mm-long inter-stump gap. We also investigated whether a C- ion-implanted tube pretreated with basic fibroblast growth factor (bFGF) promotes peripheral nerve regeneration. The C- ion implanted tube accelerated nerve regeneration, and this effect was enhanced by bFGF. Silicone treated with C- ions showed increased hydrophilic properties and cellular affinity, and axon regeneration was promoted with this increased biocompatibility.

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

    International Nuclear Information System (INIS)

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

  11. Clinical output factors for carbon-ion beams passing through polyethylene

    CERN Document Server

    Kanematsu, Nobuyuki; Ogata, Risa; Himukai, Takeshi

    2013-01-01

    Purpose: A recent study suggested that polyethylene (PE) range compensators would cause extra carbon-ion attenuation by 0.45%/cm due to limitations in water equivalence. The present study aims to assess its influence on tumor dose in carbon-ion radiotherapy. Methods: Carbon-ion radiation was modeled to be composed of primary carbon ions and secondary particles. For these components, tumor dose fraction and relative biological effectiveness (RBE) were estimated at a reference depth in the middle of spread-out Bragg peak. The PE effect was estimated for clinical carbon-ion beams and was partially tested by experiment. The two-component model was integrated into a treatment-planning system, with which the PE effect on tumor dose was investigated in two clinical cases. Results: The fluence and clinical attenuation coefficients for dose decrease per polyethylene thickness were estimated to be 0.1%-0.3%/cm and 0.2%-0.4%/cm, depending on energy and modulation of clinical carbon-ion beams. In the treatment-planning s...

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

    International Nuclear Information System (INIS)

    Ionization and dissociation of water molecules and water clusters induced by 11.7 MeV/A Ni25+ ions were carried out by imaging techniques. Branching ratios, ionisation cross sections and Kinetic Energy Released distributions have been measured together with fragmentation dynamics studies. Multiple ionization represents approximately 30% of the ionizing events. Double ionization produces in significant way atomic oxygen, considered as a possible precursor of the large production of HO2 radical in liquid water radiolysis by ions of high Linear Energy Transfer. We evidence a strong selectivity of bond breakage in the case of ion-induced HOD fragmentation. Once the molecule doubly ionized, the breakage of the O-H bond is found 6.5 times more probable than that of the O-D bond. A semi-classical calculation simulating the fragmentation dynamics on the potential energy surface of the ground-state of di-cation H2O2+ makes possible to as well reproduce the preferential nature of the breakage of the O-H bond as the position and the shift of the kinetic energy distributions. First results concerning interaction with water clusters are also reported. Measurements in coincidence are carried out giving access to correlation, with the distributions in energy and angle of the emitted fragments. Mass spectrum points fast intra-cluster proton transfer, leading to the emission of protonated clusters. (author)

  13. On novel mechanisms of slow ion induced electron emission

    CERN Document Server

    Eder, H

    2000-01-01

    impact of singly and doubly charged ions on poly- and monocrystalline aluminum surfaces were performed. From the results we conclude that direct plasmon excitation by slow ions occurs due to the potential energy of the projectile in a quasi-resonant fashion. The highest relative plasmon intensities were found for impact of 5 keV Ne+ on Al(111) with 5 % of the total yield. For impact of H + and H sub 2 + characteristical differences were observed for Al(111) and polycrystalline aluminum. We show that structures in the spectrum for monocrystalline aluminum arise from diffraction of ejected electrons instead of plasmon excitation as previously assumed. The present work has contributed in new ways to the field of slow ion induced electron emission. First, measurements of the total electron yield gamma for impact of slow singly and multiply charged ions on atomically clean polycrystalline gold and graphite have been made. The respective yields were determined by current measurements and measurements of the electro...

  14. Ion beam induced fluorescence imaging in biological systems

    International Nuclear Information System (INIS)

    Imaging fluorescence generated by MeV ions in biological systems such as cells and tissue sections requires a high resolution beam (<100 nm), a sensitive detection system and a fluorescent probe that has a high quantum efficiency and low bleaching rate. For cutting edge applications in bioimaging, the fluorescence imaging technique needs to break the optical diffraction limit allowing for sub-cellular structure to be visualized, leading to a better understanding of cellular function. In a nuclear microprobe this resolution requirement can be readily achieved utilizing low beam current techniques such as Scanning Transmission Ion Microscopy (STIM). In recent times, we have been able to extend this capability to fluorescence imaging through the development of a new high efficiency fluorescence detection system, and through the use of new novel fluorescent probes that are resistant to ion beam damage (bleaching). In this paper we demonstrate ion beam induced fluorescence imaging in several biological samples, highlighting the advantages and challenges associated with using this technique

  15. The LILIA (laser induced light ions acceleration) experiment at LNF

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Anania, M.P. [INFN LNF Frascati, Frascati (Italy); Caresana, M. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Cirrone, G.A.P. [INFN LNS Catania, Catania (Italy); De Martinis, C. [Physics Department, University of Milan and INFN, Milan (Italy); Delle Side, D. [LEAS, University of Salento and INFN, Lecce (Italy); Fazzi, A. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Gatti, G. [INFN LNF Frascati, Frascati (Italy); Giove, D. [Physics Department, University of Milan and INFN, Milan (Italy); Giulietti, D. [Physics Department, University of Pisa and INFN, Pisa (Italy); Gizzi, L.A.; Labate, L. [INO-CNR and INFN, Pisa (Italy); Londrillo, P. [Physics Department, University of Bologna and INFN, Bologna (Italy); Maggiore, M. [INFN LNL, Legnaro (Italy); Nassisi, V., E-mail: vincenzo.nassisi@le.infn.it [LEAS, University of Salento and INFN, Lecce (Italy); Sinigardi, S. [Physics Department, University of Bologna and INFN, Bologna (Italy); Tramontana, A.; Schillaci, F. [INFN LNS Catania, Catania (Italy); Scuderi, V. [INFN LNS Catania, Catania (Italy); Institute of Physics of the ASCR, Prague (Czech Republic); Turchetti, G. [Physics Department, University of Bologna and INFN, Bologna (Italy); and others

    2014-07-15

    Laser-matter interaction at relativistic intensities opens up new research fields in the particle acceleration and related secondary sources, with immediate applications in medical diagnostics, biophysics, material science, inertial confinement fusion, up to laboratory astrophysics. In particular laser-driven ion acceleration is very promising for hadron therapy once the ion energy will attain a few hundred MeV. The limited value of the energy up to now obtained for the accelerated ions is the drawback of such innovative technique to the real applications. LILIA (laser induced light ions acceleration) is an experiment now running at LNF (Frascati) with the goal of producing a real proton beam able to be driven for significant distances (50–75 cm) away from the interaction point and which will act as a source for further accelerating structure. In this paper the description of the experimental setup, the preliminary results of solid target irradiation and start to end simulation for a post-accelerated beam up to 60 MeV are given.

  16. The LILIA (laser induced light ions acceleration) experiment at LNF

    International Nuclear Information System (INIS)

    Laser-matter interaction at relativistic intensities opens up new research fields in the particle acceleration and related secondary sources, with immediate applications in medical diagnostics, biophysics, material science, inertial confinement fusion, up to laboratory astrophysics. In particular laser-driven ion acceleration is very promising for hadron therapy once the ion energy will attain a few hundred MeV. The limited value of the energy up to now obtained for the accelerated ions is the drawback of such innovative technique to the real applications. LILIA (laser induced light ions acceleration) is an experiment now running at LNF (Frascati) with the goal of producing a real proton beam able to be driven for significant distances (50–75 cm) away from the interaction point and which will act as a source for further accelerating structure. In this paper the description of the experimental setup, the preliminary results of solid target irradiation and start to end simulation for a post-accelerated beam up to 60 MeV are given

  17. Interaction of small hydrocarbon ions and Ar(+) with carbon-fibre-composite surfaces at room temperature

    Czech Academy of Sciences Publication Activity Database

    Keim, A.; Rasul, B.; Endstrasser, N.; Scheier, P.; Märk, T. D.; Herman, Zdeněk

    2011-01-01

    Roč. 306, 2-3 (2011), s. 204-209. ISSN 1387-3806 Institutional research plan: CEZ:AV0Z40400503 Keywords : ion-surface collisions * Ar+ and hydrocarbon ions * carbon-fibre-composite surface Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.549, year: 2011

  18. Collisions of fast, highly stripped carbon, niobium, and lead ions with molecular hydrogen

    International Nuclear Information System (INIS)

    The range of experimental confirmation of our scaling rule for electron loss from a hydrogen atom in collision with a heavy, highly stripped ion has been considerably broadened by new measurements on carbon-, niobium-, and lead-ion projectiles in molecular hydrogen

  19. Semiconductor characterization by scanning ion beam induced charge (IBIC) microscopy

    CERN Document Server

    Vittone, E; Olivero, P; Manfredotti, C; Jaksic, M; Giudice, A Lo; Fizzotti, F; Colombo, E

    2016-01-01

    The acronym IBIC (Ion Beam Induced Charge) was coined in early 1990's to indicate a scanning microscopy technique which uses MeV ion beams as probes to image the basic electronic properties of semiconductor materials and devices. Since then, IBIC has become a widespread analytical technique to characterize materials for electronics or for radiation detection, as testified by more than 200 papers published so far in peer-reviewed journals. Its success stems from the valuable information IBIC can provide on charge transport phenomena occurring in finished devices, not easily obtainable by other analytical techniques. However, IBIC analysis requires a robust theoretical background to correctly interpret experimental data. In order to illustrate the importance of using a rigorous mathematical formalism, we present in this paper a benchmark IBIC experiment aimed to test the validity of the interpretative model based on the Gunn's theorem and to provide an example of the analytical capability of IBIC to characteriz...

  20. Swift heavy ion induced structural modifications in GaAs

    International Nuclear Information System (INIS)

    Semi-insulating GaAs (111) were irradiated with 100 MeV Au and 200 MeV Ag ions. The energies of the ion beams were chosen to keep nearly same electronic energy loss, but different nuclear energy loss. The samples were characterized by x-ray diffraction (XRD) to observe structural changes. The full width at half maximum (FWHM) increased with fluence showing amorphization behavior. The peak intensities also showed decreasing behaviour with fluence. But the changes in peak intensities as well as FWHM of XRD peaks after irradiation are almost same for both Au and Ag beams. The structural modification of GaAs is found to be mainly due to inelastic collision induced electronic energy loss rather than nuclear energy loss. (author)

  1. Nanoclustering in Silicon Induced by Oxygen Ions Implanted

    Directory of Open Access Journals (Sweden)

    D. Manno

    2011-11-01

    Full Text Available We report about the nanoclustering induced by oxygen‐implantation in silicon. A tandem‐type accelerator, with a maximum acceleration voltage of 3 MV, equipped with a sputtering ion source suitable for the production of high current ion beams by sputtering of solid cathodes has been used. The surface modifications and the structure of nanoclusters are investigated. The topographic images, obtained by scanning tunnelling microscope showed that the surface is covered with a dense array of tetragonal nanostructures oriented with respect to the substrate. Raman spectroscopy data allowed us to estimate an average cluster size of about 50 nm. Resistivity and Hall effect measurements evidenced that the electron transport in the implanted silicon samples is affected by the nanoclusters array and it could be explained by thermally activated hopping between localized states.

  2. Ion beam induced conductivity in chemically vapor deposited diamond films

    International Nuclear Information System (INIS)

    Polycrystalline diamond films deposited by the microwave plasma chemical vapor deposition (CVD) technique onto quartz substrates have been irradiated with 100 keV C and 320 keV Xe ions at room temperature and at 200 degree C. The dose dependence of the electrical conductivity measured in situ exhibited complicated, nonmonotonic behavior. High doses were found to induce an increase of up to ten orders of magnitude in the electrical conductivity of the film. The dose dependence of the conductivity for the CVD films was found to be very similar to that measured for natural, type IIa, single-crystal diamonds irradiated under identical conditions. This result suggests that the conduction mechanism in ion beam irradiated polycrystalline CVD diamond films is not dominated by grain boundaries and graphitic impurities as one might have expected, but rather is determined by the intrinsic properties of diamond itself

  3. Metal Ions Extraction with Glucose Derivatives as Chelating Reagents in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    Guo Chen YANG; Hai Jian YANG

    2006-01-01

    A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-1-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr2+ and Pb2+ extraction in supercritical carbon dioxide.

  4. Modifying the electronic structure of semiconducting single-walled carbon nanotubes by Ar+ ion irradiation

    NARCIS (Netherlands)

    Tolvanen, A.; Buchs, G.; Ruffieux, P.; Gröning, P.; Gröning, O.; Krasheninnikov, A.V.

    2009-01-01

    Local controllable modification of the electronic structure of carbon nanomaterials is important for the development of carbon-based nanoelectronics. By combining density-functional theory simulations with Ar-ion-irradiation experiments and low-temperature scanning tunneling microscopy and spectrosc

  5. Beam Energy Scaling of Ion-Induced Electron Yield from K+ Ions Impact on Stainless Steel Surfaces

    CERN Document Server

    Kireeff-Covo, Michel; Barnard, John J; Bieniosek, Frank; Celata, C M; Cohen, Ronald; Friedman, Alex; Grote, D P; Kwan, Joe W; Lund, Steven M; Molvik, Arthur; Seidl, Peter; Vay, Jean-Luc; Vujic, Jasmina L; Westenskow, Glen

    2005-01-01

    The cost of accelerators for heavy-ion inertial fusion energy (HIF) can be reduced by using the smallest possible clearance between the beam and the wall from the beamline. This increases beam loss to the walls, generating ion-induced electrons that could be trapped by beam space charge potential into an "electron cloud," which can cause degradation or loss of the ion beam. In order to understand the physical mechanism of production of ion-induced electrons we have measured impact of K+ ions with energies up to 400 KeV on stainless steel surfaces near grazing incidence, using the ion source test stand (STS-500) at LLNL. The electron yield will be discussed and compared with experimental measurements from 1 MeV K+ ions in the High-Current Experiment at LBNL.*

  6. Hydroxyl radical induced decarboxylation and deamination of 2-methylalanine catalyzed by copper ions

    International Nuclear Information System (INIS)

    Using the pulse radiolysis technique, the rate constants of the reactions of ·CH2C(CH3)(NH3+)COO- (the radical derived via H-abstraction from 2-methylalanine) with Cu2+aq and Cu+aq to form unstable intermediates with a copper-carbon σ-bond have been determined to be (1.3 ± 0.3) x 107 and (1.3 ± 0.2) x 109 M-1s-1, respectively. In the case of cupric ions, the transient decomposes via a β-carboxyl elimination reaction yielding Cu+aq, CH3COCH3, and CO2, whereas in the case of cuprous ions it decomposes via a β-amine elimination reaction yielding Cu2+aq, CH2 double-bond C(CH3)COO-, and NH3. A reaction mechanism for aliphatic radical induced amino acid damage catalyzed by copper ions in different oxidation states is suggested. This mechanism describes a plausible new pathway for biological damage induced by free radicals

  7. Hypofractionated carbon ion therapy delivered with scanned ion beams for patients with hepatocellular carcinoma – feasibility and clinical response

    International Nuclear Information System (INIS)

    Photon-based radiation therapy does currently not play a major role as local ablative treatment for hepatocellular carcinoma (HCC). Carbon ions offer distinct physical and biological advantages. Due to their inverted dose profile and the high local dose deposition within the Bragg peak, precise dose application and sparing of normal tissue is possible. Furthermore, carbon ions have an increased relative biological effectiveness (RBE) compared to photons. A total of six patients with one or more HCC-lesions were treated with carbon ions delivered by the raster-scanning technique according to our clinical trial protocol. Diagnosis of HCC was confirmed by histology or two different imaging modalities (CT and MRI) according to the AASLD-guidelines. Applied fractionation scheme was 4 × 10 Gy(RBE). Correct dose application was controlled by in-vivo PET measurement of β + −activity in the irradiated tissue shortly after treatment. Patients were observed for a median time period of 11.0 months (range, 3.4 – 12.7 months). Imaging studies showed a partial response in 4/7 lesions and a stable disease in 3/7 lesions in follow-up CT- and MRI scans. Local control was 100%. One patient with multifocal intrahepatic disease underwent liver transplantation 3 months after carbon ion therapy. During radiotherapy and the follow-up period no severe adverse events have occurred. We report the first clinical results of patients with HCC undergoing carbon ion therapy using the rasterscanning technique at our institution. All patients are locally controlled and experienced no higher toxicities in a short follow-up period. Further patients will be included in our prospective Phase-I clinical trial PROMETHEUS-01 (NCT01167374)

  8. Swift heavy ion induced modification of aliphatic polymers

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Umme Habiba

    2015-01-15

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

  9. Analysis of heavy-ion irradiation induced adverse effect on normal tissue in murine model

    International Nuclear Information System (INIS)

    The purpose of this study was to clarify the molecular mechanism of C-ion radiation induced late injury of lung and urinary bladder in normal tissue, using murine model. Exposures were conducted using horizontal carbon-12 beams with 290 MeV/u at a dose rate of approximately 3 Gy/min within the 6-cm spread-out Bragg peak (SOBP). To evaluate the effects of C-ion irradiation on lungs, pathological changes after thoracic irradiation were analyzed. To evaluate the adverse effects on the bladder, pathological evaluation were performed. The gene expression analysis were performed using total RNA derived from irradiated tissues on 6 hour after irradiation to elucidate the molecular response to irradiation. Survival assay revealed the subacute phase death by hemorrhagic pneumonitis in C3H/He and the late phase death by pulmonary fibrosis in C57BL/6J after C-ion irradiation. Microarray analysis presented the genes with strain variance after C-ion irradiation. Immunohistochemical staining of LAMP family proteins, which relates bladder contraction, in the irradiated urinary bladder were different between strains. (author)

  10. A moderator ion exchange model to predict carbon-14 behaviour during operations

    International Nuclear Information System (INIS)

    Carbon-14 emissions from CANDU 6 stations are reduced through the removal of inorganic carbon ions by the ion exchange (IX) columns in the moderator purification system. A model has been developed to simulate the ion exchange behaviour of anions and cations present in the moderator. The model can be used to generate breakthrough curves for IX columns. Results from the program were compared to breakthrough curves generated by a small-scale experimental facility as well as data collected from Wolsong-3 where the IX column remained in service well past the recommended time. In both cases, the breakthrough curves were similar to the collected data. (author)

  11. Charge equilibrium of a laser-generated carbon-ion beam in warm dense matter

    International Nuclear Information System (INIS)

    Using ion carbon beams generated by high intensity short pulse lasers we perform measurements of single shot mean charge equilibration in cold or isochorically heated solid density aluminum matter. We demonstrate that plasma effects in such matter heated up to 1 eV do not significantly impact the equilibration of carbon ions with energies 0.045-0.5 MeV/nucleon. Furthermore, these measurements allow for a first evaluation of semiempirical formulas or ab initio models that are being used to predict the mean of the equilibrium charge state distribution for light ions passing through warm dense matter. (authors)

  12. Computational Evaluation of Amorphous Carbon Coating for Durable Silicon Anodes for Lithium-Ion Batteries

    OpenAIRE

    Jeongwoon Hwang; Jisoon Ihm; Kwang-Ryeol Lee; Seungchul Kim

    2015-01-01

    We investigate the structural, mechanical, and electronic properties of graphite-like amorphous carbon coating on bulky silicon to examine whether it can improve the durability of the silicon anodes of lithium-ion batteries using molecular dynamics simulations and ab-initio electronic structure calculations. Structural models of carbon coating are constructed using molecular dynamics simulations of atomic carbon deposition with low incident energies (1–16 eV). As the incident energy decrease...

  13. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    CERN Document Server

    Tanaka, T; Shinohara, M; Takagi, T

    2002-01-01

    Application of pulsed high negative voltage (approx 10 mu s pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N sub 2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N sub 2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron mic...

  14. Tilting of carbon encapsulated metallic nanocolumns in carbon-nickel nanocomposite films by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Matthias [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Technische Universitaet Dresden, D-01062 Dresden (Germany); Muecklich, Arndt; Zschornak, Matthias; Wintz, Sebastian; Gemming, Sibylle; Abrasonis, Gintautas [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Oates, Thomas W. H. [Leibniz-Institut fuer Analytische Wissenschaft, ISAS e.V., Albert-Einstein-Str. 9, 12489 Berlin (Germany); Luis Endrino, Jose [Surfaces and Coatings Department, Instituto de Ciencia de Materiales de Madrid, c/Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Baehtz, Carsten; Shalimov, Artem [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Rossendorf Beamline, European Synchrotron Radiation Facility, F-38043 Grenoble (France)

    2012-07-30

    The influence of assisting low-energy ({approx}50-100 eV) ion irradiation effects on the morphology of C:Ni ({approx}15 at. %) nanocomposite films during ion beam assisted deposition (IBAD) is investigated. It is shown that IBAD promotes the columnar growth of carbon encapsulated metallic nanoparticles. The momentum transfer from assisting ions results in tilting of the columns in relation to the growing film surface. Complex secondary structures are obtained, in which a significant part of the columns grows under local epitaxy via the junction of sequentially deposited thin film fractions. The influence of such anisotropic film morphology on the optical properties is highlighted.

  15. Comparison of H2 and He carbon cleaning mechanisms in extreme ultraviolet induced and surface wave discharge plasmas

    CERN Document Server

    Dolgov, A; Rachimova, T; Kovalev, A; Vasilyeva, A; Lee, C J; Krivtsun, V M; Yakushev, O; Bijkerk, F

    2013-01-01

    Cleaning of contamination of optical surfaces by amorphous carbon (a-C) is highly relevant for extreme ultraviolet (EUV) lithography. We have studied the mechanisms for a-C removal from a Si surface. By comparing a-C removal in a surface wave discharge (SWD) plasma and an EUV-induced plasma, the cleaning mechanisms for hydrogen and helium gas environments were determined. The C-atom removal per incident ion was estimated for different sample bias voltages and ion fluxes. It was found that H2 plasmas generally had higher cleaning rates than He plasmas: up to seven times higher for more negatively biased samples in EUV induced plasma. Moreover, for H2, EUV induced plasma was found to be 2-3 times more efficient at removing carbon than the SWD plasma. It was observed carbon removal during exposure to He is due to physical sputtering by He+ ions. In H2, on the other hand, the increase in carbon removal rates is due to chemical sputtering. This is a new C cleaning mechanism for EUV-induced plasma, which we call "E...

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

    Indian Academy of Sciences (India)

    W Udo Schröder

    2015-08-01

    Fission instabilities induced by mechanical and thermal stresses on intermediate nuclear systems in heavy-ion reactions are poorly understood but should reveal independent evidence for the nuclear equation of state (EoS), notably the tensile strength of finite nuclei. Experimental evidence is presented in support of a new mode of prompt fission of the composite nucleus formed in central 78Kr+40Ca collisions at only a few MeV per nucleon above the interaction barrier. The new process recalls the ‘L-window for fusion’ phenomenon, which was predicted by the early reaction theory and reappears in modern DFT model calculations.

  17. Production of secondary neutrons from patients during therapy with carbon ions, their dose contributions and potential risks

    International Nuclear Information System (INIS)

    By making use of the experimental neutron production data from different elements, under bombardment with carbon ions of 100 to 400 MeV/u energies, we have estimated the flux and energy distribution of secondary neutron produced in patients during therapy with C-ions. Our results indicate that at least 4 neutrons, with energies greater than 5 MeV, are produced for every C-ion of 400 MeV/u energy incident on tissue; which reduces to 3, 1.4 and 0.3 respectively at incident C-ion energies of 300, 200 and 100 MeV/u. For a typical therapy C-ion dose of 20 Gy (physical), the effective whole body dose due to the secondary neutrons is estimated to be about 1 Sv, that is about 5% of the incident C-ion dose for 400 MeV/u energy. The doses to 22 organs from these neutrons have also been estimated and ranges up to 230 mGy cm and 2 at an incident C-ion energy of 400 MeV/n. These figures could be higher if neutrons with energies less than 5 MeV, about which we do not have any experimental data, were also included. In our opinion these neutron doses are large enough to potentially cause secondary cancers and induce other harmful effects into patients. Therefore, this matter of secondary neutrinos from patients during therapy with C-ions must be even more thoroughly investigated before continuing therapy with C-ions. (author)

  18. Exposure to Carbon Ions Triggers Proinflammatory Signals and Changes in Homeostasis and Epidermal Tissue Organization to a Similar Extent as Photons

    Science.gov (United States)

    Simoniello, Palma; Wiedemann, Julia; Zink, Joana; Thoennes, Eva; Stange, Maike; Layer, Paul G.; Kovacs, Maximilian; Podda, Maurizio; Durante, Marco; Fournier, Claudia

    2016-01-01

    The increasing application of charged particles in radiotherapy requires a deeper understanding of early and late side effects occurring in skin, which is exposed in all radiation treatments. We measured cellular and molecular changes related to the early inflammatory response of human skin irradiated with carbon ions, in particular cell death induction and changes in differentiation and proliferation of epidermal cells during the first days after exposure. Model systems for human skin from healthy donors of different complexity, i.e., keratinocytes, coculture of skin cells, 3D skin equivalents, and skin explants, were used to investigate the alterations induced by carbon ions (spread-out Bragg peak, dose-averaged LET 100 keV/μm) in comparison to X-ray and UV-B exposure. After exposure to ionizing radiation, in none of the model systems, apoptosis/necrosis was observed. Carbon ions triggered inflammatory signaling and accelerated differentiation of keratinocytes to a similar extent as X-rays at the same doses. High doses of carbon ions were more effective than X-rays in reducing proliferation and inducing abnormal differentiation. In contrast, changes identified following low-dose exposure (≤0.5 Gy) were induced more effectively after X-ray exposure, i.e., enhanced proliferation and change in the polarity of basal cells. PMID:26779439

  19. Exposure to carbon ions triggers pro-inflammatory signals, changes in homeostasis and epidermal tissue organization to a similar extent as photons

    Directory of Open Access Journals (Sweden)

    Palma eSimoniello

    2016-01-01

    Full Text Available The increasing application of charged particles in radiotherapy requires a deeper understanding of early and late side effects occurring in skin, which is exposed in all radiation treatments. We measured cellular and molecular changes related to the early inflammatory response of human skin irradiated with carbon ions, in particular cell death induction and changes in differentiation and proliferation of epidermal cells during the first days after exposure.Model systems for human skin from healthy donors of different complexity, i.e. keratinocytes, co-culture of skin cells, 3D skin equivalent and skin explants, were used to investigate the alterations induced by carbon ions (spread-out Bragg-peak, dose averaged LET 100 keV/µm in comparison to X-ray and UV-B exposure. After exposure to ionizing radiation, in none of the model systems apoptosis/necrosis was observed. Carbon ions triggered inflammatory signalling and accelerated differentiation of keratinocytes to a similar extent as X-rays at the same doses. High doses of carbon ions were more effective than X-rays in reducing proliferation and inducing abnormal differentiation. In contrast, changes identified following low dose exposure (≤ 0.5 Gy were induced more effectively after X-ray exposure, i.e. enhanced proliferation and change in the polarity of basal cells.

  20. Ion induced scintillation in organic solids: development of an average track model,degradation of the scintillation intensity and dosimetric applications

    International Nuclear Information System (INIS)

    This work deals with a specific aspect of the ion-matter interaction: the scintillation induced by ions in organic materials. In the first chapter we tackle the issue in a theoretical way by proposing a method to compute the radial doses within the framework of the mean track model. We have developed a model based on the Lewis transport equation and on the Spencer distribution of the loss energy in order to take into account the transport of secondary electrons in a more realistic way. In the second chapter we study the physical mechanisms that trigger ion-induced scintillation. Ion-induced scintillation is featured by the dependence in charge number of the intensity of scintillation for ions with same energy loss and by the saturation of the scintillation efficiency for ions with high stopping-power. We have applied our model of radial doses to ion-induced scintillation. In the third chapter we study the gradual degradation of the scintillation intensity and ion-induced chemical damages. In the last chapter we propose a prototype of dosimeters based on the combination of scintillators and optical fibers that allows the real-time measurement of the dose delivered by a carbon ion beam in therapeutical use conditions. This dosimeter gives the relationship between the dose and the scintillation intensity but its accuracy is not yet sufficient for uses in radiotherapy. (A.C.)

  1. Measurement of contact resistance of multiwall carbon nanotubes by electrical contact using a focused ion beam

    International Nuclear Information System (INIS)

    Carbon nanotubes (CNTs) have found many potential applications but using CNTs as building blocks for nanoelectronics is still challenging. Various micro- and nanofabrication techniques including focused ion beam (FIB) are therefore being developed for combining CNTs into a nanodevice or to help assess the electrical properties of integrated CNTs. In this paper, multiwall carbon nanotubes (MWNTs) are assembled between a pair of gold (Au) electrodes by dielectrophoresis (DEP). Contact resistances of MWNT-Au and, in particular, MWNT-MWNT are measured with the help of making electrical connections between a MWNT and electrodes by FIB induced tungsten deposition. A method for resistance calculation is presented which considers the contact length of MWNTs. Under the conditions of this research, measured conducting resistances of MWNTs were from 1–10 kΩ/μm and the contact resistance of MWNTs with Au was around 100 kΩ μm. The contact resistance between MWNTs varied depending on contact configurations and could be as low as 50 KΩ. The effect of FIB parameters on the measurement results is discussed.

  2. Measurement of contact resistance of multiwall carbon nanotubes by electrical contact using a focused ion beam

    Energy Technology Data Exchange (ETDEWEB)

    An Libao, E-mail: lan@heut.edu.cn [College of Mechanical Engineering, Hebei United University, Tangshan, Hebei, 063009 (China); Friedrich, Craig R. [Department of Mechanical Engineering - Engineering Mechanics, Michigan Technological University, Houghton, MI 49931 (United States)

    2012-02-01

    Carbon nanotubes (CNTs) have found many potential applications but using CNTs as building blocks for nanoelectronics is still challenging. Various micro- and nanofabrication techniques including focused ion beam (FIB) are therefore being developed for combining CNTs into a nanodevice or to help assess the electrical properties of integrated CNTs. In this paper, multiwall carbon nanotubes (MWNTs) are assembled between a pair of gold (Au) electrodes by dielectrophoresis (DEP). Contact resistances of MWNT-Au and, in particular, MWNT-MWNT are measured with the help of making electrical connections between a MWNT and electrodes by FIB induced tungsten deposition. A method for resistance calculation is presented which considers the contact length of MWNTs. Under the conditions of this research, measured conducting resistances of MWNTs were from 1-10 k{Omega}/{mu}m and the contact resistance of MWNTs with Au was around 100 k{Omega} {mu}m. The contact resistance between MWNTs varied depending on contact configurations and could be as low as 50 K{Omega}. The effect of FIB parameters on the measurement results is discussed.

  3. The early effects in the brain after irradiation with carbon ions using mice

    International Nuclear Information System (INIS)

    This study investigated both early and late effects in the brain after irradiation with carbon ions using mice. The irradiation dose was set at level known to produce vascular change followed by necrosis, which appeared the late period after irradiation with 30 Gy. The whole of brain was irradiated, excluding eyes and brain stem. The mice irradiated with single dose of 30 Gy showed deficit in short-term working memory assessed at 36 hr after irradiation, whereas mice receiving carbon irradiation showed no deficit in long-term reference memory. At 16 weeks after irradiation, the irradiated mice showed marked learning impairment compared with age-matched controls and the irradiated mice showed substantial impairment of working memory. Histopathological observation revealed no abnormal finding in the irradiated brain at 36 hr after irradiation, although irradiated mice showed marked neuronal degeneration at the hippocampus within CA1 to CA3 layers at 16 weeks after irradiation. In the irradiated group, neuronal cells in the hippocampal CA1-3 areas were reduced by 30-49%. These results suggest that although irradiation-induced hippocampal degeneration is associated with learning disability, cognitive deficits may also be detected on the early stage, not associated with hippocampal degeneration. (author)

  4. In vitro evaluation of photon and carbon ion radiotherapy in combination with chemotherapy in glioblastoma cells

    International Nuclear Information System (INIS)

    To evaluate the cytotoxic effect of carbon ion radiotherapy and chemotherapy in glioblastoma cells in vitro. The human glioblastoma (GBM) cell line U87 was irradiated with photon radiotherapy (RT) doses of 2 Gy, 4 Gy and 6 Gy. Likewise, irradiation with carbon ions was performed with single carbon doses of 0.125, 0.5, 2 and 3 Gy. Four chemotherapeutic substances, camptothecin, gemcitabine, paclitaxel and cisplatinum, were used for single and combination experiments. The assessment of the effect of single and double treatment on cell viability was performed using the clonogenic growth assay representing the radiobiological gold standard. The RBE of carbon ions ranges between 3.3 and 3.9 depending on survival level and dose. All chemotherapeutic substances showed a clear does-response relationhips. in their characteristic concentrations. For subsequent combination experiments, two dose levels leading to low and medium reduction of cell survival were chosen. Combination experiments showed additive effects independently of the drugs' mechanisms of action. Paclitaxel and campthothecin demonstrated the most prominent cytotoxic effect in combination with carbon ion radiotherapy. In conclusion, combination of carbon ion radiotherapy with chemotherapies of different mechanisms of action demonstrates additive effects. The most dominant effect was produced by paclitaxel, followed by camptothecin, as espected from previously published work. The present data serve as an important radiobiological basis for further combination experiments, as well as clinical studies on combination treatments

  5. Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

    International Nuclear Information System (INIS)

    Highlights: ► Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. ► MPCS was covalently modified by cysteine (MPCS–CO–Cys). ► MPCS–CO–Cys was first time used in electrochemical detection of heavy metal ions. ► Heavy metal ions such as Pb2+ and Cd2+ can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

  6. The Anion Effect on Li+ Ion Coordination Structure in Ethylene Carbonate Solutions

    CERN Document Server

    Jiang, Bo; Shen, Yuneng; Yang, Xueming; Yuan, Kaijun; Vetere, Valentina; Mossa, Stefano; Skarmoutsos, Ioannis; Zhang, Yufan; Zheng, Junrong

    2016-01-01

    Rechargeable lithium ion batteries are an attractive alternative power source for a wide variety of applications. To optimize their performances, a complete description of the solvation properties of the ion in the electrolyte is crucial. A comprehensive understanding at the nanoscale of the solvation structure of lithium ions in nonaqueous carbonate electrolytes is, however, still unclear. We have measured by femtosecond vibrational spectroscopy the orientational correlation time of the CO stretching mode of Li+-bound and Li+-unbound ethylene carbonate molecules, in LiBF4, LiPF6, and LiClO4 ethylene carbonate solutions with different concentrations. Surprisingly, we have found that the coordination number of ethylene carbonate in the first solvation shell of Li+ is only two, in all solutions with concentrations higher than 0.5 M. Density functional theory calculations indicate that the presence of anions in the first coordination shell modifies the generally accepted tetrahedral structure of the complex, all...

  7. Ion beam induced luminescence analysis of painting pigments

    Energy Technology Data Exchange (ETDEWEB)

    Quaranta, A. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy); E-mail: quaranta@ing.unitn.it; Salomon, J. [Centre de Recherche et de Restauration des Musees de France, CNRS UMR 171, rue des Pyramides, 75041 Paris Cedex 01 (France); Dran, J.C. [Centre de Recherche et de Restauration des Musees de France, CNRS UMR 171, rue des Pyramides, 75041 Paris Cedex 01 (France); Tonezzer, M. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy); Della Mea, G. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy)

    2007-01-15

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields.

  8. Ion beam induced luminescence analysis of painting pigments

    International Nuclear Information System (INIS)

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields

  9. Ion beam induced luminescence analysis of painting pigments

    Science.gov (United States)

    Quaranta, A.; Salomon, J.; Dran, J. C.; Tonezzer, M.; Della Mea, G.

    2007-01-01

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields.

  10. Copper ions removal from water using functionalized carbon nanotubes–mullite composite as adsorbent

    International Nuclear Information System (INIS)

    Highlights: • CNTs–mullite composite was prepared via chemical vapor deposition (CVD) method. • The prepared composite was modified with concentrated nitric acid and chitosan. • The modified CNTs–mullite composites were used as novel adsorbents. • Copper ion removal from water by the prepared adsorbents was performed. • Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. - Abstract: Carbon nanotubes–mullite composite was synthesized by direct growth of carbon nanotubes on mullite particles via chemical vapor deposition method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. The carbon nanotubes–mullite composite was oxidized with concentrated nitric acid and functionalized with chitosan and then used as a novel adsorbent for copper ions removal from water. The results demonstrated that modification with concentrated nitric acid and chitosan improves copper ions adsorption capacity of the prepared composite, significantly. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. The carbon nanotubes growth on mullite particles to form the carbon nanotubes–mullite composite with further modification is an inherently safe approach for many promising environmental applications to avoid some concerns regarding environment, health and safety. It was found that the modified carbon nanotubes–mullite composite can be considered as an excellent adsorbent for copper ions removal from water

  11. Copper ions removal from water using functionalized carbon nanotubes–mullite composite as adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Tofighy, Maryam Ahmadzadeh; Mohammadi, Toraj, E-mail: torajmohammadi@iust.ac.ir

    2015-08-15

    Highlights: • CNTs–mullite composite was prepared via chemical vapor deposition (CVD) method. • The prepared composite was modified with concentrated nitric acid and chitosan. • The modified CNTs–mullite composites were used as novel adsorbents. • Copper ion removal from water by the prepared adsorbents was performed. • Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. - Abstract: Carbon nanotubes–mullite composite was synthesized by direct growth of carbon nanotubes on mullite particles via chemical vapor deposition method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. The carbon nanotubes–mullite composite was oxidized with concentrated nitric acid and functionalized with chitosan and then used as a novel adsorbent for copper ions removal from water. The results demonstrated that modification with concentrated nitric acid and chitosan improves copper ions adsorption capacity of the prepared composite, significantly. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. The carbon nanotubes growth on mullite particles to form the carbon nanotubes–mullite composite with further modification is an inherently safe approach for many promising environmental applications to avoid some concerns regarding environment, health and safety. It was found that the modified carbon nanotubes–mullite composite can be considered as an excellent adsorbent for copper ions removal from water.

  12. Successive ionization of positive ions of carbon and nitrogen by electron bombardment

    International Nuclear Information System (INIS)

    Experimental studies of deep ionization of heavy ions are described. The applications of such studies in atomic physics, plasma physics and space physics are discussed. Investigations using intersecting ion-electron beams, shifted beams and ion trap sources are described, and data are presented for multi-charged ions of carbon, oxygen and nitrogen. A detailed description of the development of the IEL (electron beam ionizer) source, and the KRION (cryogenic version) source is given, and further data for the multiple ionization of carbon and nitrogen are given for charge states up to C6+ and N7+. The advantages and disadvantages of the KRION source are discussed, and preliminary studies of a new torroidal ion trap source (HIRAC) are presented. (11 figs, 57 refs) (U.S.)

  13. Improvement of polydimethylsiloxane guide tube for nerve regeneration treatment by carbon negative-ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, H. E-mail: tsuji@kuee.kyoto-u.ac.jp; Izukawa, M.; Ikeguchi, R.; Kakinoki, R.; Sato, H.; Gotoh, Y.; Ishikawa, J

    2003-05-01

    Modification of polydimethylsiloxane (PDMS) rubber by negative ion-implantation was investigated for improvement of nerve regeneration property. The PDMS rubber surface was found to have more hydrophilic property after carbon negative-ion implantation than before. At the conditions of 10 keV and 3.0 x 10{sup 15} ions/cm{sup 2}, the contact angle decreased to 83 deg. from 100 deg. . The reason of the hydrophilic modification is due to hydrophilic functional groups such as hydroxyl formed at the surface by radiation effect of ion implantation. The in vivo regeneration test of rat sciatic nerve was performed by using 18-mm-long PDMS rubber tubes with inner diameter of 2 mm, the inner surface of which was implanted with carbon negative ions at the above conditions. At 24 weeks after the clinical surgery, the sciatic nerve was regenerated through the tube between the proximal and distal nerve stumps.

  14. Field-effect ion-transport devices with carbon nanotube channels: schematics and simulations

    International Nuclear Information System (INIS)

    We investigated field-effect ion-transport devices based on carbon nanotubes by using classical molecular dynamics simulations under applied external force fields, and we present model schematics that can be applied to the nanoscale data storage devices and unipolar ionic field-effect transistors. As the applied external force field is increased, potassium ions rapidly flow through the nanochannel. Under low external force fields, thermal fluctuations of the nanochannels affect tunneling of the potassium ions whereas the effects of thermal fluctuations are negligible under high external force fields. Since the electric current conductivity increases when potassium ions are inserted into fullerenes or carbon nanotubes, the field effect due to the gate, which can modify the position of the potassium ions, changes the tunneling current between the drain and the source.

  15. Field-effect ion-transport devices with carbon nanotube channels: schematics and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju Yul; Kang, Jeong Won; Byun, Ki Ryang; Kang, Eu Seok; Hwang, Ho Jung [Chung-Ang University, Seoul (Korea, Republic of); Lee, Jun Ha; Lee, Hoong Joo [Sangmyung University, Chonan (Korea, Republic of); Kwon, Oh Keun [Semyung University, Jecheon (Korea, Republic of); Kim, Young Min [Chung-Cheong University, Cheongwon (Korea, Republic of)

    2004-08-15

    We investigated field-effect ion-transport devices based on carbon nanotubes by using classical molecular dynamics simulations under applied external force fields, and we present model schematics that can be applied to the nanoscale data storage devices and unipolar ionic field-effect transistors. As the applied external force field is increased, potassium ions rapidly flow through the nanochannel. Under low external force fields, thermal fluctuations of the nanochannels affect tunneling of the potassium ions whereas the effects of thermal fluctuations are negligible under high external force fields. Since the electric current conductivity increases when potassium ions are inserted into fullerenes or carbon nanotubes, the field effect due to the gate, which can modify the position of the potassium ions, changes the tunneling current between the drain and the source.

  16. Laser induced deformation in polydimethylsiloxane membranes with embedded carbon nanopowder

    International Nuclear Information System (INIS)

    We demonstrate optically induced micron-range deformation of polydimethylsiloxane (PDMS) membranes with embedded carbon nanopowder. The mechanical deformation can be controlled by low power laser irradiation of the samples and the resulting surface modifications are analyzed via dynamic speckle measurements. Photothermal effects due to optical absorption by the nanopowder are shown to deform the polymer samples leading to localized mechanical stresses induced via thermal expansion of the PDMS. (technical note)

  17. Ion-induced nucleation of pure biogenic particles

    Science.gov (United States)

    Kirkby, Jasper; Duplissy, Jonathan; Sengupta, Kamalika; Frege, Carla; Gordon, Hamish; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K.; Wagner, Robert; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill; Dias, Antonio; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R.; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P.; Pringle, Kirsty; Rap, Alexandru; Richards, Nigel A. D.; Riipinen, Ilona; Rissanen, Matti P.; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E.; Seinfeld, John H.; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander L.; Wagner, Andrea C.; Wagner, Paul E.; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M.; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M.; Worsnop, Douglas R.; Baltensperger, Urs; Kulmala, Markku; Carslaw, Kenneth S.; Curtius, Joachim

    2016-05-01

    Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere, and that ions have a relatively minor role. Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded. Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of α-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported by quantum chemical calculations of the cluster binding energies of representative HOMs. Ion-induced nucleation of pure organic particles constitutes a potentially widespread source of aerosol particles in terrestrial environments with low sulfuric acid pollution.

  18. Ion-induced nucleation of pure biogenic particles.

    Science.gov (United States)

    Kirkby, Jasper; Duplissy, Jonathan; Sengupta, Kamalika; Frege, Carla; Gordon, Hamish; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K; Wagner, Robert; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill; Dias, Antonio; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P; Pringle, Kirsty; Rap, Alexandru; Richards, Nigel A D; Riipinen, Ilona; Rissanen, Matti P; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E; Seinfeld, John H; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander L; Wagner, Andrea C; Wagner, Paul E; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M; Worsnop, Douglas R; Baltensperger, Urs; Kulmala, Markku; Carslaw, Kenneth S; Curtius, Joachim

    2016-05-26

    Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere, and that ions have a relatively minor role. Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded. Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of α-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported by quantum chemical calculations of the cluster binding energies of representative HOMs. Ion-induced nucleation of pure organic particles constitutes a potentially widespread source of aerosol particles in terrestrial environments with low sulfuric acid pollution. PMID:27225125

  19. Influence of Zn ion implantation on structures and field emission properties of multi-walled carbon nanotube arrays

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The structures and field emission properties of multi-walled carbon nanotube arrays implanted with Zn+ by MEVVA ion implanter have been investigated.The results revealed that Zn+implantation induced structural damage and that the top of carbon nanotubes with multi-layered graphite structure were transformed into carbon nanowires with amorphous structure.Meanwhile,C:Zn solid solution was synthesized after Zn+ implantation.The turn-on field and threshold field were 0.80 and 1.31 V/μm,respectively for original multi-walled carbon nanotube arrays and were reduced to 0.66 and 1.04 V/μm due to the synthesis of C and Zn composite,in which the work function was reduced after low doses of Zn+implantation.It is indicated that low doses of Zn+implantation can improve field emission performance of multi-walled carbon nanotube arrays.Otherwise,high doses of Zn+implantation can reduce field emission properties of multi-walled carbon nanotube arrays,because radiation damage reduces the electric field enhancement factor.

  20. Nonelastic nuclear reactions induced by light ions with the BRIEFF code

    CERN Document Server

    Duarte, H

    2010-01-01

    The intranuclear cascade (INC) code BRIC has been extended to compute nonelastic reactions induced by light ions on target nuclei. In our approach the nucleons of the incident light ion move freely inside the mean potential of the ion in its center-of-mass frame while the center-of-mass of the ion obeys to equations of motion dependant on the mean nuclear+Coulomb potential of the target nucleus. After transformation of the positions and momenta of the nucleons of the ion into the target nucleus frame, the collision term between the nucleons of the target and of the ion is computed taking into account the partial or total breakup of the ion. For reactions induced by low binding energy systems like deuteron, the Coulomb breakup of the ion at the surface of the target nucleus is an important feature. Preliminary results of nucleon production in light ion induced reactions are presented and discussed.

  1. Heavy-ion induced genetic changes and evolution processes

    Science.gov (United States)

    Yang, C. H.; Craise, L. M.; Durante, M.; Mei, M.

    1994-01-01

    On Moon and Mars, there will be more galactic cosmic rays and higher radiation doses than on Earth. Our experimental studies showed that heavy ion radiation can effectively cause mutation and chromosome aberrations and that high Linear Energy Transfer (LET) heavy-ion induced mutants can be irreversible. Chromosome translocations and deletions are common in cells irradiated by heavy particles, and ionizing radiations are effective in causing hyperploidy. The importance of the genetic changes in the evolution of life is an interesting question. Through evolution, there is an increase of DNA content in cells from lower forms of life to higher organisms. The DNA content, however, reached a plateau in vertebrates. By increasing DNA content, there can be an increase of information in the cell. For a given DNA content, the quality of information can be changed by rearranging the DNA. Because radiation can cause hyperploidy, an increase of DNA content in cells, and can induce DNA rearrangement, it is likely that the evolution of life on Mars will be effected by its radiation environment. A simple analysis shows that the radiation level on Mars may cause a mutation frequency comparable to that of the spontaneous mutation rate on Earth. To the extent that mutation plays a role in adaptation, radiation alone on Mars may thus provide sufficient mutation for the evolution of life.

  2. Advanced Electron Beam Ion Sources (EBIS) for 2-nd generation carbon radiotherapy facilities

    International Nuclear Information System (INIS)

    In this work we analyze how advanced Electron Beam Ion Sources (EBIS) can facilitate the progress of carbon therapy facilities. We will demonstrate that advanced ion sources enable operation of 2-nd generation ion beam therapy (IBT) accelerators. These new accelerator concepts with designs dedicated to IBT provide beams better suited for therapy and, are more cost efficient than contemporary IBT facilities. We will give a sort overview of the existing new IBT concepts and focus on those where ion source technology is the limiting factor. We will analyse whether this limitation can be overcome in the near future thanks to ongoing EBIS development

  3. Advanced Electron Beam Ion Sources (EBIS) for 2-nd generation carbon radiotherapy facilities

    Science.gov (United States)

    Shornikov, A.; Wenander, F.

    2016-04-01

    In this work we analyze how advanced Electron Beam Ion Sources (EBIS) can facilitate the progress of carbon therapy facilities. We will demonstrate that advanced ion sources enable operation of 2-nd generation ion beam therapy (IBT) accelerators. These new accelerator concepts with designs dedicated to IBT provide beams better suited for therapy and, are more cost efficient than contemporary IBT facilities. We will give a sort overview of the existing new IBT concepts and focus on those where ion source technology is the limiting factor. We will analyse whether this limitation can be overcome in the near future thanks to ongoing EBIS development.

  4. Carbon induced reactions at low incident energies

    International Nuclear Information System (INIS)

    Accurate knowledge of the reactions which occur when two heavy ions interact is of importance in many trans-disciplinary fields, particularly in cancer therapy and space radiation protection. In these cases one needs to know what happens in a natural process to which all possible reaction mechanisms contribute and thus a theoretical calculation, to be really usable, must indeed be able to reproduce large sets of data in wide energy and mass ranges. We show here the results of an analysis of the spectra of intermediate mass fragments produced in the C + Al interaction at 13 MeV/n, both in direct and inverse kinematics, which supplies a very reasonable reproduction of a great number of data providing useful information on the leading reaction mechanisms

  5. Mechanism of lithium carbonate induced hyperdipsia

    OpenAIRE

    Brime Casanueva, Juan Ignacio; López-Sela Melendez de Arvás, Purificacion; Argüelles Luis, Juan; Costales Pérez, Marina; Vijande Vázquez, Manuel

    1999-01-01

    Los pacientes psiquiátricos y los animales de laboratorio tratados con carbonato de litio desarrollan una importante poliuria y polidipsia. La polidipsia puede ser un fenómeno primario que induce una poliuria secundaria o alternativamente, una poliuria primaria podría ser la causa de la polidipsia observada. Nuestros experimentos utilizando ratas macho nefrectomizadas tratadas con litio, sugieren que la poliuria sea primaria y la polidipsia secundaria. Estos resultados se confirman cuando se ...

  6. Li-ion capacitors with carbon cathode and hard carbon/stabilized lithium metal powder anode electrodes

    Science.gov (United States)

    Cao, W. J.; Zheng, J. P.

    2012-09-01

    A lithium-ion capacitor was developed using a mixture of stabilized lithium metal powder and hard carbon as the anode electrode, while activated carbon was used as the cathode. A specific energy of approximately 82 Wh kg-1 was obtained based on the weight of electrode materials; however, when the electrolyte, separator, and current collectors were included, the specific energy of an assembled Li-ion capacitor was about 25 Wh kg-1. The capacitor was able to deliver over 60% of the maximum energy at a discharge C-rate of 44C. Through continuous galvanostatic charge/discharge cycling, the capacitance of the Li-ion capacitor degraded less than 3% over 600 cycles.

  7. Ion-radical intermediates of the radiation-chemical transformations of organic carbonates

    Science.gov (United States)

    Shiryaeva, Ekaterina S.; Sosulin, Ilya S.; Saenko, Elizaveta V.; Feldman, Vladimir I.

    2016-07-01

    The spectral features and reactions of ion-radical intermediates produced from organic carbonates in low-temperature matrices were investigated by EPR spectroscopy and quantum-chemical calculations. It was shown that radical cations of diethyl carbonate and dimethyl carbonate underwent intramolecular hydrogen transfer to yield alkyl-type species, as was suggested previously. Meanwhile, radical cation of EC demonstrates a ring cleavage even at 77 K, while radical cation of PC is probably intrinsically stable and undergo an ion-molecule reaction with a neighboring neutral molecule in dimers or associates. Radical anions were obtained in glassy matrices of diethyl ether or perdeuteroethanol. The radical anions of linear carbonates show photoinduced fragmentation to yield the corresponding alkyl radicals; such process may also occur directly under radiolysis. Radical anions of cyclic carbonates are relatively stable and yield only trace amounts of fragmentation products under similar conditions.

  8. Nucleation and growth of carbon onions by means of simultaneous electron microscopic observation under ion implantation

    International Nuclear Information System (INIS)

    In-situ and ex-situ TEM observation was performed in copper implanted with carbon ions at temperature from 570 K to 973 K. Carbon clusters, such as carbon onions (concentric graphic spheres) and nanocapsules (concentric graphitic spheres with cavities), were observed with amorphous carbon layers. Statistics of cluster size as a function of implantation temperature, ion fluence and substrate crystallinity revealed the nucleation processes of the clusters. One is the formation of graphitic layers on grain boundaries. The other is the nucleation of graphitic cages, probably fullerenes, due to both high concentration of carbon atoms and high amount of radiation damage. Simultaneous observation of microstructural evolution under implantation revealed that onions were formed inside the substrate not surface and that they segregate at surface due to radiation-enhanced evaporation. (author)

  9. Influence of bicarbonate and carbonate ions on sonochemical degradation of Rhodamine B in aqueous phase.

    Science.gov (United States)

    Merouani, Slimane; Hamdaoui, Oualid; Saoudi, Fethi; Chiha, Mahdi; Pétrier, Christian

    2010-03-15

    The influence of bicarbonate and carbonate ions on sonolytic degradation of cationic dye, Rhodamine B (RhB), in water was investigated. As a consequence of ultrasonic cavitation that generates .OH radicals, carbonate radicals were secondary products of water sonochemistry when it contains dissolved bicarbonate or carbonate ions. The results clearly demonstrated the significant intensification of sonolytic destruction of RhB in the presence of bicarbonate and carbonate, especially at lower dye concentrations. Degradation intensification occurs because carbonate radicals sonochemically formed undergo radical-radical recombination at a lesser extent than hydroxyl radicals. The generated carbonate radicals are likely able to migrate far from the cavitation bubbles towards the solution bulk and are suitable for degradation of an organic dye such as RhB. Therefore, at low dye concentrations, carbonate radical presents a more selective reactivity towards RhB molecules than hydroxyl radical. In the presence of bicarbonate, degradation rate reached a maximum at 3 g L(-1) bicarbonate, but subsequent addition retards the destruction process. In RhB solutions containing carbonate, the oxidation rate gradually increased with increasing carbonate concentration up to 10 g L(-1) and slightly decreased afterward. Carbonate radicals sonochemically generated are suitable for total removal of COD of sonicated RhB solutions. PMID:19910116

  10. Advanced carbon materials/olivine LiFePO4 composites cathode for lithium ion batteries

    Science.gov (United States)

    Gong, Chunli; Xue, Zhigang; Wen, Sheng; Ye, Yunsheng; Xie, Xiaolin

    2016-06-01

    In the past two decades, LiFePO4 has undoubtly become a competitive candidate for the cathode material of the next-generation LIBs due to its abundant resources, low toxicity and excellent thermal stability, etc. However, the poor electronic conductivity as well as low lithium ion diffusion rate are the two major drawbacks for the commercial applications of LiFePO4 especially in the power energy field. The introduction of highly graphitized advanced carbon materials, which also possess high electronic conductivity, superior specific surface area and excellent structural stability, into LiFePO4 offers a better way to resolve the issue of limited rate performance caused by the two obstacles when compared with traditional carbon materials. In this review, we focus on advanced carbon materials such as one-dimensional (1D) carbon (carbon nanotubes and carbon fibers), two-dimensional (2D) carbon (graphene, graphene oxide and reduced graphene oxide) and three-dimensional (3D) carbon (carbon nanotubes array and 3D graphene skeleton), modified LiFePO4 for high power lithium ion batteries. The preparation strategies, structure, and electrochemical performance of advanced carbon/LiFePO4 composite are summarized and discussed in detail. The problems encountered in its application and the future development of this composite are also discussed.

  11. UV-induced carbon monoxide emission from living vegetation

    DEFF Research Database (Denmark)

    Bruhn, Dan; Albert, Kristian Rost; Mikkelsen, Teis Nørgaard;

    2013-01-01

    The global burden of carbon monoxide (CO) is rather uncertain. In this paper we address the potential for UV-induced CO emission by living terrestrial vegetation surfaces. Real-time measurements of CO concentrations were made with a cavity enhanced laser spectrometer connected in closed loop to...

  12. Identification of promoters and enhancers induced by carbon nanotube exposure

    DEFF Research Database (Denmark)

    Bornholdt, Jette; Lilje, Berit; Saber, Anne Thoustrup;

    Usage of carbon nanotubes (CNTs) is increasing in industry due to their mechanical and electrical properties. However, pulmonary exposure to CNTs induces, an asbestos-like toxicological response characterized by persistent inflammation, granuloma formation and fibrosis with low no-effect levels...

  13. Secondary Ion Mass Spectrometry of Small-Molecule Solids at Cryogenic Temperatures. 1. Nitrogen and Carbon Monoxide

    OpenAIRE

    Jonkman, Harry T.; Michl, Josef

    1981-01-01

    Secondary ion mass spectra of solid nitrogen and carbon monoxide were observed at 15 K. The effects of the nature and energy of the primary probe ion were investigated. Direct charge transfer, inelastic momentum transfer, association reactions, and ion-molecule reactions all seem to contribute to the formation of the secondary charged particles. With the heavier probe ions extensive cluster formation was observed.

  14. The Experimental Measurement of the Relative Biological Effectiveness of Carbon Ions with Different Qualities

    Institute of Scientific and Technical Information of China (English)

    WANG Jufang; LI Wenjian

    2008-01-01

    The relative biological effectiveness (RBE) of carbon ions with linear energy transfer (LET) of 172 keV/μm and 13.7 keV/μm were determined in this study. The clonogenic survival and premature terminal differentiation were measured on normal human fibroblasts AG01522C and NHDF after exposure of the cells to 250 kV X-rays and carbon ions with different qualities. RBE was determined for these two biological end points. The results showed that the measured RBE10 with a survival fraction of 10% was 3.2 for LET 172 keV/μm, and 1.33 for LET 13.7 keV/μm carbon ions. RBE for a doubling of post-mitotic fibroblasts (PMF) in the population was 2.8 for LET 172 keV/μm, and 1 for LET 13.7 keV/μm carbon ions. For the carbon ion therapy, a high RBE value on the Bragg peak results in a high biological dose on the tumour. The tumour cells can be killed effectively. At the same time, the dose on healthy tissue would be reduced accordingly. This will lighten the late effect such as fibrosis on normal tissue.

  15. Calculation of Lifetime of Charge-Exchanging Carbon Targets in Intense Heavy Ion Beams

    CERN Document Server

    Gikal, B N; Kazacha, V I; Kamanin, D V

    2005-01-01

    Influence of the radiation damage and sublimation effects on the lifetime of carbon targets used for the accelerated ion beam extraction from cyclotrons by the charge-exchanging method is considered. The theoretical models permitting evaluation of the carbon target lifetime depending on their and ion beam parameters are presented both for the radiation damage and sublimation effects. It is shown that for the U-400 cyclotron carbon targets 50 $\\mu$g/cm$^{2}$ thick and for the ion beam flux density up to 100 p$\\mu$A/cm$^{2}$ the main effect defining the carbon target lifetime is the radiation damage. If the carbon target thickness and the ion beam flux density are greater, the target lifetime is defined already by the sublimation effect. In this connection "casting pipes" can be formed in the target, affecting on the mean energy and the energy distribution dispersion of the ion beam flied through the target. Comparison of measured and calculated target lifetimes is carried out

  16. Experience With Carbon Ion Radiotherapy for WHO Grade 2 Diffuse Astrocytomas

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Azusa [Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba (Japan); Mizoe, Jun-Etsu, E-mail: junetsumizoe@gmail.com [Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba (Japan); Tsujii, Hirohiko; Kamada, Tadashi; Jingu, Keiichi [Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba (Japan); Iwadate, Yasuo [Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba (Japan); Nakazato, Youichi [Department of Human Pathology, Gunma University Graduate School of Medicine, Gunma (Japan); Matsutani, Masao [Department of Neurological Surgery, Saitama Medical University, Saitama (Japan); Takakura, Kintomo [Department of Neurological Surgery, Tokyo Women' s Medical University, Tokyo (Japan)

    2012-05-01

    Purpose: To assess outcomes of carbon ion radiotherapy for diffuse astrocytomas in adults. Methods and Materials: Between October 1994 and February 2002, 14 patients with diffuse astrocytoma, identified as eligible for carbon ion radiotherapy, were enrolled in a phase I/II clinical trial. Carbon ion radiotherapy was administered in 24 fractions over 6 weeks. The normal tissue morbidity was monitored carefully, and the carbon ion dose was escalated from 50.4 Gy equivalent (GyE) to 55.2 GyE. Patients were divided into two groups according to their carbon ion doses: a low-dose group in which 2 patients were irradiated with 46.2 GyE and 7 patients were irradiated with 50.4 GyE, and a high-dose group in which 5 patients were irradiated with 55.2 GyE. Results: Toxicities were within acceptable limits, and none of the patients developed Grade 3 or higher acute or late reactions. The median progression-free survival (PFS) time was 18 months for the low-dose group and 91 months for the high-dose group (p = 0.0030). The median overall survival (OS) time was 28 months for the low-dose group and not reached for the high-dose group (p = 0.0208). Conclusion: High-dose group patients showed significant improvement in PFS and OS rates compared to those in the low-dose group, and both dose groups showed acceptable toxicity.

  17. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    LIQiang; ZHOUGuang-Ming; 等

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accelerated carbon ions with linear energy transfers of 125.5,200 and 700keV/um were measured,respectively,Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves.They are 7.86±0.17,10.44±1.11 and 32.32±3.59um2 in turn.With the surviving response of V79 cells to 60Co γ-rays as a reference value,relative biological effectiveness at 10%,20%,50%and 80% survival levels were given for the accelerated carbon ions,The results showed that carbon ions with LET of 125.5keV/um had a higher value of RBE at all the four survival levels than the carbon ions with other LETs.It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200keV/um for carbon ions.

  18. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accclerated carbon ions with linear energy transfers of 125.5, 200 and 700 keV/μm were measured, respectively. Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves. They are 7.86±0.17, 10.44±1.11 and 32.32±3.58 μm2 in turn. With the surviving response of V79 cells to 60Co γ-rays as a reference value, relative biological effectiveness at 10%, 20%, 50% and 80% survival levels were given for the accelerated carbon ions. The results showed that carbon ions with LET of 125.5 keV/μm had a higher value of RBE at all the four survival levels than the carbon ions with other LETs. It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200 keV/μm for carbon ions.

  19. Experience With Carbon Ion Radiotherapy for WHO Grade 2 Diffuse Astrocytomas

    International Nuclear Information System (INIS)

    Purpose: To assess outcomes of carbon ion radiotherapy for diffuse astrocytomas in adults. Methods and Materials: Between October 1994 and February 2002, 14 patients with diffuse astrocytoma, identified as eligible for carbon ion radiotherapy, were enrolled in a phase I/II clinical trial. Carbon ion radiotherapy was administered in 24 fractions over 6 weeks. The normal tissue morbidity was monitored carefully, and the carbon ion dose was escalated from 50.4 Gy equivalent (GyE) to 55.2 GyE. Patients were divided into two groups according to their carbon ion doses: a low-dose group in which 2 patients were irradiated with 46.2 GyE and 7 patients were irradiated with 50.4 GyE, and a high-dose group in which 5 patients were irradiated with 55.2 GyE. Results: Toxicities were within acceptable limits, and none of the patients developed Grade 3 or higher acute or late reactions. The median progression-free survival (PFS) time was 18 months for the low-dose group and 91 months for the high-dose group (p = 0.0030). The median overall survival (OS) time was 28 months for the low-dose group and not reached for the high-dose group (p = 0.0208). Conclusion: High-dose group patients showed significant improvement in PFS and OS rates compared to those in the low-dose group, and both dose groups showed acceptable toxicity.

  20. Determination of carbon distributions in quenched and partitioned microstructures using nanoscale secondary ion mass spectroscopy

    International Nuclear Information System (INIS)

    A multi-modal characterization technique, which combines nanoscale secondary ion mass spectroscopy (Nano-SIMS) with a spatial resolution of ∼100 nm and electron back scatter diffraction (EBSD) to determine carbon distributions in austenite and martensite in a quenched and partitioned (Q&P) Fe–0.29C–2.95Mn–1.59Si steel is presented. Significant carbon enrichment of austenite was measured with decreased levels of carbon in martensite, supporting the carbon partitioning mechanism. Fresh untempered martensite could be identified, and different degrees of enrichment were observed for blocky and lath austenite

  1. Carbon analysis for inspecting carbonation of concrete using a TEA CO2 laser-induced plasma.

    Science.gov (United States)

    Kagawa, Kiichiro; Idris, Nasrullah; Wada, Munehide; Kurniawan, Hendrik; Tsuyuki, Kenichiro; Miura, Satoru

    2004-08-01

    It has been demonstrated that a spectrochemical analysis of carbon using the laser plasma method can be successfully applied to inspect the carbonation of concrete by detecting carbon produced in aged concrete by a chemical reaction of Ca(OH)2 with CO2 gas in environmental air, turning into CaCO3, which induces degradation of the quality of building concrete. A comparative study has been made using a TEA CO2 laser (500-1000 mJ) and a Q-switched Nd-YAG laser (50-200 mJ) to search for the optimum conditions for carbon analysis, proving the advantage of the TEA CO2 laser for this purpose. Also, it was clarified that laser irradiation with suitable defocusing conditions is a crucial point for obtaining high sensitivity in the detection of carbon. Practical experiments on the inspection of carbonation were carried out using both a concrete sample that had been intentionally carbonated by exposure to high concentrations of CO2 gas and a naturally carbonated concrete sample. As a result, good coincidence was observed between the laser method and the ordinary method, which uses the chemical indicator phenolphthalein, implying that this laser technique is applicable as an in situ quantitative method of inspection for carbonation of concrete. PMID:18070383

  2. Exact Dirac equation calculation of ionization induced by ultrarelativistic heavy ions

    OpenAIRE

    Baltz, Anthony J.

    1999-01-01

    The time-dependent Dirac equation can be solved exactly for ionization induced by ultrarelativistic heavy ion collisions. Ionization calculations are carried out in such a framework for a number of representative ion-ion pairs. For each ion-ion pair, the computed cross section consists of two terms, a constant energy independent term and a term whose coefficient is ln(gamma). Scaled values of both terms are found to decrease with increasing Z of the nucleus that is ionized.

  3. Characterization of silicon- and carbon-based composite anodes for lithium-ion batteries

    International Nuclear Information System (INIS)

    In recent years development of active materials for negative electrodes has been of great interest. Special attention has been focused on the active materials possessing higher reversible capacity than that of conventional graphite. In the present work the electrochemical performance of some carbon/silicon-based materials has been analyzed. For this purpose various silicon-based composites were prepared using such carbon materials as graphite, hard carbon and graphitized carbon black. An analysis of charging-discharging processes at electrodes based on different carbon materials has shown that graphite modified with silicon is the most promising anode material. It has also been revealed that the irreversible capacity mainly depends on the content of Si. An optimum content of Si has been determined with taking into account that high irreversible capacity is not suitable for practical application in lithium-ion batteries. This content falls within the range of 8-10 wt%. The reversible capacity of graphite modified with 8 wt% carbon-coated Si was as high as 604 mAh g-1. The irreversible capacity loss with this material was as low as 8.1%. The small irreversible capacity of the material allowed developing full lithium-ion rechargeable cells in the 2016 coin cell configuration. Lithium-ion batteries based on graphite modified with silicon show gravimetric and volumetric specific energy densities which are higher by approximately 20% than those for a lithium-ion battery based on natural graphite

  4. Plasma-ion-induced Sputtering And Heating Of Titan'S Atmosphere

    Science.gov (United States)

    Tucker, Orenthal J.

    2006-09-01

    Plasma-ion-induced sputtering and heating of Titan's atmosphere O.J. Tucker (1), R.E. Johnson (1), M. Michael (1), V.I. Shematovich (1,2) J.H. Luhmann (3), S.A. Ledvina (3) (1) University of Virginia, Charlottesville, VA 22904, USA (2) Institute of Astronomy RAS, Moscow 109017, Russia, (3) University of California, Berkeley, CA 94720, USA Titan is unique among the outer solar system icy satellites in having an atmosphere with a column density about ten times that of the Earth's atmosphere. Atmospheres equivalent in size similar to that at Titan would have been removed from the icy Galilean satellites by the plasma trapped in the Jovian magnetosphere (Johnson 2004). In this paper we describe the deposition of energy, the erosion and the expansion of the upper atmosphere of Titan using Direct Simulation Monte Carlo models (Shematovich et al. 2003; Michael et al. 2005). These calculations are used to calibrate semi-empirical models of atmospheric sputtering (Johnson 1994) that can be employed in interpreting Cassini data at Titan. It is shown that the globally averaged flux of magnetospheric and pickup ions deposit more energy in Titan's upper atmosphere than solar radiation. Using a number of plasma conditions, the temperature and density vs. altitude above the exobase and the rate of escape are calculated and compared to available Cassini data. References: Johnson, R.E. "Plasma-induced Sputtering of an Atmosphere" in Space Science Reviews 69 215-253 (1994). Johnson. R.E., “ The magnetospheric plasma-driven evolution of satellite atmospheres” Astrophys. J. 609, L99-L102 (2004). Michael M., R.E. Johnson, F. Leblanc, M. Liu, J.G. Luhmann, and V.I. Shematovich, "Ejection of nitrogen from Titan's atmosphere by magnetospheric ions and pick-up ions", Icarus 175, 263-267 (2005). Shematovich, V.I., R.E. Johnson, M. Michael, and J.G. Luhmann,"Nitrogen loss from Titan", JGR 108, No. E8, 5087, doi:10.1029/2003JE002094 (2003). 1

  5. Characterization of silicon and carbon dual ion-implanted metals with a nano-indentation

    International Nuclear Information System (INIS)

    The dual ion implantation of silicon and carbon into copper (99.9%), iron (99.9%), SKD11 steel and SUS304 austenitic stainless steels was carried out with a MeV energy ion accelerator. The cross-section of the implanted layer were observed with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The surface layers of the implanted substrates were investigated with X-ray photoelectron spectroscopy (XPS) and a transmission electron microscope (TEM). The hardness of the samples was tested with a nano-indentation. It was found with XPS Si (2p) spectra and TEM that a part of the Si ions and C ions formed an amorphous layer of SiC, carbide and metals by dual ion-implantation. The hardness of the dual ion-implanted steels were improved. The mechanism of hardness was suggested by cross-sectional TEM images. (author)

  6. Heavy Ion Beams Induce Survivin Expression in Human Hepatoma SMMC-7721 Cells More Effectively than X-rays

    Institute of Scientific and Technical Information of China (English)

    Li GONG; Xiaodong JIN; Qiang LI; Jiangtao LIU; Lizhe AN

    2007-01-01

    High linear energy transfer (LET) heavy ion radiation is more effective in inducing biological damage than low-LET X-rays or γ-rays. Heavy ion beam provides good dose localization (Bragg peak) in critical cancer tissue and gives higher relative biological effectiveness in cell killing across the dose peak, so high-LET heavy ion beam is superior to low-LET radiation in cancer treatment. Survivin, as a member of the inhibitor of apoptosis protein family, might help cancerous cells to overcome the G2/M apoptotic checkpoint and favor the aberrant progression of transformed cells through mitosis. Survivin expression in the human hepatoma SMMC-7721 cell line after exposure to low-LET X-ray and high-LET carbon ion irradiation was investigated in this study. Compared with X-ray irradiation, the carbon ion beam clearly caused G2/M arrest and promoted the expression of the survivin gene in a dose-dependent manner. Clonogenic survival assay showed that SMMC-7721 cells were more radiosensitive to the high-LET carbon ions than to the X-rays, and the radiosensitivity was promoted after treatment with specific survivin short interfering RNA. Differential survivin expression at both transcriptional and translational levels was found for SMMC-7721 cells following low- and high-LET irradiation. The overexpression of survivin in SMMC-7721 cells is probably an important reason why the cancerous cells have radioresistance to strong stimulus such as dense ionizing high-LET radiation. However, the direct killing effect on cancerous cells by high-LET radiation might be more significant than the apoptosis inhibition through the overexpression of survivin following heavy ion irradiation.

  7. Detection of DNA damage induced by heavy ion irradiation in the individual cells with comet assay

    Science.gov (United States)

    Wada, S.; Natsuhori, M.; Ito, N.; Funayama, T.; Kobayashi, Y.

    2003-05-01

    Investigating the biological effects of high-LET heavy ion irradiation at low fluence is important to evaluate the risk of charged particles. Especially it is important to detect radiation damage induced by the precise number of heavy ions in the individual cells. Thus we studied the relationship between the number of ions traversing the cell and DNA damage produced by the ion irradiation. We applied comet assay to measure the DNA damage in the individual cells. Cells attached on the ion track detector CR-39 were irradiated with ion beams at TIARA, JAERI-Takasaki. After irradiation, the cells were stained with ethidium bromide and the opposite side of the CR-39 was etched. We observed that the heavy ions with higher LET values induced the heavier DNA damage. The result indicated that the amount of DNA damage induced by one particle increased with the LET values of the heavy ions.

  8. Effects of Carbon Structure and Surface Oxygen on the Carbon's Performance as the Anode in Lithium-Ion Battery Determined

    Science.gov (United States)

    Hung, Ching-Cheh

    2000-01-01

    Four carbon materials (C1, C2, C3, and C4) were tested electrochemically at the NASA Glenn Research Center at Lewis Field to determine their performance in lithium-ion batteries. They were formed as shown in the figure. This process caused very little carbon loss. Products C1 and C3 contained very little oxygen because of the final overnight heating at 540 C. Products C2 and C4, on the other hand, contained small amounts of basic oxide. The electrochemical test involved cycles of lithium intercalation and deintercalation using C/saturated LiI-50/50 (vol %) ethylene carbonate (EC) and dimethyl carbonate (DMC)/Li half cell. The cycling test, which is summarized in the table, resulted in three major conclusions. The capacity of the carbon with a basic oxide surface converges to a constant 1. value quickly (within 4 cycles), possibly because the oxide prevents solvent from entering the carbon structure and, therefore, prolongs the carbon s cycle life. Under certain conditions, the disordered carbon can store more lithium than its 2. precursor. These samples and their precursor can intercalate at 200 mA/g and deintercalate at 3. a rate of 2000 mA/g without significant capacity loss.

  9. Carbon plasma immersion ion implantation of nickel-titanium shape memory alloys.

    Science.gov (United States)

    Poon, R W Y; Yeung, K W K; Liu, X Y; Chu, P K; Chung, C Y; Lu, W W; Cheung, K M C; Chan, D

    2005-05-01

    Nickel-titanium (NiTi) shape memory alloys possess super-elasticity in addition to the well-known shape memory effect and are potentially suitable for orthopedic implants. However, a critical concern is the release of harmful Ni ions from the implants into the living tissues. We propose to enhance the corrosion resistance and other surface and biological properties of NiTi using carbon plasma immersion ion implantation and deposition (PIII&D). Our corrosion and simulated body fluid tests indicate that either an ion-mixed amorphous carbon coating fabricated by PIII&D or direct carbon PIII can drastically improve the corrosion resistance and block the out-diffusion of Ni from the materials. Our tribological tests show that the treated surfaces are mechanically more superior and cytotoxicity tests reveal that both sets of plasma-treated samples favor adhesion and proliferation of osteoblasts. PMID:15585228

  10. Benchmarking nuclear models of FLUKA and GEANT4 for carbon ion therapy

    CERN Document Server

    Bohlen, TT; Quesada, J M; Bohlen, T T; Cerutti, F; Gudowska, I; Ferrari, A; Mairani, A

    2010-01-01

    As carbon ions, at therapeutic energies, penetrate tissue, they undergo inelastic nuclear reactions and give rise to significant yields of secondary fragment fluences. Therefore, an accurate prediction of these fluences resulting from the primary carbon interactions is necessary in the patient's body in order to precisely simulate the spatial dose distribution and the resulting biological effect. In this paper, the performance of nuclear fragmentation models of the Monte Carlo transport codes, FLUKA and GEANT4, in tissue-like media and for an energy regime relevant for therapeutic carbon ions is investigated. The ability of these Monte Carlo codes to reproduce experimental data of charge-changing cross sections and integral and differential yields of secondary charged fragments is evaluated. For the fragment yields, the main focus is on the consideration of experimental approximations and uncertainties such as the energy measurement by time-of-flight. For GEANT4, the hadronic models G4BinaryLightIonReaction a...

  11. Removal of Lead (II Ions from Aqueous Solutions onto Activated Carbon Derived from Waste Biomass

    Directory of Open Access Journals (Sweden)

    Murat Erdem

    2013-01-01

    Full Text Available The removal of lead (II ions from aqueous solutions was carried out using an activated carbon prepared from a waste biomass. The effects of various parameters such as pH, contact time, initial concentration of lead (II ions, and temperature on the adsorption process were investigated. Energy Dispersive X-Ray Spectroscopy (EDS analysis after adsorption reveals the accumulation of lead (II ions onto activated carbon. The Langmuir and Freundlich isotherm models were applied to analyze equilibrium data. The maximum monolayer adsorption capacity of activated carbon was found to be 476.2 mg g−1. The kinetic data were evaluated and the pseudo-second-order equation provided the best correlation. Thermodynamic parameters suggest that the adsorption process is endothermic and spontaneous.

  12. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo;

        Radiotherapy with particles is getting more attention in Europe. New facilities for protons and heavier ions are finished, or near to the final status, some more are planed. Particle therapy with heavy ions is a challenge to dosimetry, since mixed particle fields occur in the peak region...... of the depth dose curves. Solid state detectors, such as diamond detectors, radiochromic films, TLDs and the amino acid alanine are used due to there good spatial resolution. If used in particle beams their response often exhibits a dependence on particle energy and type, so the acquired signal is not always...... proportional to absorbed dose. A model by Hansen and Olsen, based on the Track Structure Theory is available, which can predict the relative efficiency of some detectors, when the particle spectrum is known. For alanine detectors the model was successfully validated by Hansen and Olsen for several ion species...

  13. Recent studies in heavy ion induced fission reactions

    Indian Academy of Sciences (India)

    R K Choudhury

    2001-08-01

    Nuclear fission process involves large scale shape changes of the nucleus, while it evolves from a nearly spherical configuration to two separated fission fragments. The dynamics of these shape changes in the nuclear many body system is governed by a strong interplay of the collective and single particle degrees of freedom. With the availability of heavy ion accelerators, there has been an impetus to study the nuclear dynamics through the investigations of nucleus–nucleus collisions involving fusion and fission process. From the various investigations carried out in the past years, it is now well recognized that there is large scale damping of collective modes in heavy ion induced fission reactions, which in other words implies that nuclear motion is highly viscous. In recent years, there have been many experimental observations in heavy ion induced fission reactions at medium bombarding energies, which suggest possible occurrence of various non-equilibrium modes of fission such as quasi-fission, fast fission and pre-equilibrium fission, where some of the internal degrees of freedom of the nucleus is not fully equilibrated. We have carried out extensive investigations on the fission fragment angular distributions at near barrier bombarding energies using heavy fissile targets. The measured fragment anisotropies when compared with the standard saddle point model (SSPM) calculations show that for projectile-target systems having zero or low ground state spins, the angular anisotropy exhibits a peak-like behaviour at the sub barrier energies, which cannot be explained by the SSPM calculations. For projectiles or targets with large ground state spins, the anomalous peaking gets washed out due to smearing of the -distribution by the intrinsic entrance channel spins. Recently studies have been carried out on the spin distributions of fission fragments through the gamma ray multiplicity measurements. The fission fragments acquire spin mainly from two

  14. Preparation of graphene on Cu foils by ion implantation with negative carbon clusters

    International Nuclear Information System (INIS)

    We report on few-layer graphene synthesized on Cu foils by ion implantation using negative carbon cluster ions, followed by annealing at 950 °C in vacuum. Raman spectroscopy reveals IG/I2D values varying from 1.55 to 2.38 depending on energy and dose of the cluster ions, indicating formation of multilayer graphene. The measurements show that the samples with more graphene layers have fewer defects. This is interpreted by graphene growth seeded by the first layers formed via outward diffusion of C from the Cu foil, though nonlinear damage and smoothing effects also play a role. Cluster ion implantation overcomes the solubility limit of carbon in Cu, providing a technique for multilayer graphene synthesis. (paper)

  15. Influence of nuclear interactions in polyethylene range compensators for carbon-ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Nobuyuki, E-mail: nkanemat@nirs.go.jp; Koba, Yusuke; Ogata, Risa [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Himukai, Takeshi [Ion Beam Therapy Center, SAGA HIMAT Foundation, 415 Harakoga-machi, Tosu, Saga 841-0071 (Japan)

    2014-07-15

    Purpose: A recent study revealed that polyethylene (PE) would cause extra carbon-ion attenuation per range shift by 0.45%/cm due to compositional differences in nuclear interactions. The present study aims to assess the influence of PE range compensators on tumor dose in carbon-ion radiotherapy. Methods: Carbon-ion radiation was modeled to be composed of primary carbon ions and secondary particles, for each of which the dose and the relative biological effectiveness (RBE) were estimated at a tumor depth in the middle of spread-out Bragg peak. Assuming exponential behavior for attenuation and yield of these components with depth, the PE effect on dose was calculated for clinical carbon-ion beams and was partly tested by experiment. The two-component model was integrated into a treatment-planning system and the PE effect was estimated in two clinical cases. Results: The attenuation per range shift by PE was 0.1%–0.3%/cm in dose and 0.2%–0.4%/cm in RBE-weighted dose, depending on energy and range-modulation width. This translates into reduction of RBE-weighted dose by up to 3% in extreme cases. In the treatment-planning study, however, the effect on RBE-weighted dose to tumor was typically within 1% reduction. Conclusions: The extra attenuation of primary carbon ions in PE was partly compensated by increased secondary particles for tumor dose. In practical situations, the PE range compensators would normally cause only marginal errors as compared to intrinsic uncertainties in treatment planning, patient setup, beam delivery, and clinical response.

  16. Unity yield conditions for sputtering of graphite by carbon ions

    International Nuclear Information System (INIS)

    Selfsputtering yields for graphite have been investigated as function of ion energy, target temperature and angle of incidence. While the yield for normal incidence at room temperature never exceeds unity, both enhanced temperature and grazing angle of incidence can lead to a selfsputtering larger than one. Theoretical predictions of 100% ion reflection at angles of incidence above 850 could not be observed for energies smaller than 300 eV. The data are interpolated to construct regions of selfsputtering larger than unity in the energy versus angle-of-incidence space for temperatures up to 1900 K. (orig.)

  17. Highly stable linear carbonate-containing electrolytes with fluoroethylene carbonate for high-performance cathodes in sodium-ion batteries

    Science.gov (United States)

    Lee, Yongwon; Lee, Jaegi; Kim, Hyungsub; Kang, Kisuk; Choi, Nam-Soon

    2016-07-01

    Employing linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) as electrolyte solvents provides an opportunity to design appropriate electrolyte systems for high-performance sodium-ion batteries (SIBs). However, in practice, the use of linear carbonate-containing electrolytes is quite challenging because linear carbonates readily decompose at Na metal electrodes or sodiated anodes. One of the promising approaches is using an electrolyte additive to resolve the critical problems related to linear carbonates. Our investigation reveals that remarkable enhancement in electrochemical performance of Na4Fe3(PO4)2(P2O7) cathodes with linear carbonate-containing electrolytes is achieved by using a fluoroethylene carbonate (FEC) additive. Importantly, the initial Coulombic efficiency of the Na deposition/stripping on a stainless steel (SS) electrode is drastically improved from 16% to 90% by introducing the FEC additive into ethylene carbonate (EC)/propylene carbonate (PC)/DEC (5/3/2, v/v/v)/0.5 M NaClO4. The underlying mechanism of FEC at the electrode-electrolyte interface is clearly demonstrated by 13C nuclear magnetic resonance (NMR). In addition, the Na4Fe3(PO4)2(P2O7) cathode in EC/PC/DEC (5/3/2, v/v/v)/0.5 M sodium perchlorate (NaClO4) with FEC delivers a discharge capacity of 90.5 mAh g-1 at a current rate of C/2 and exhibits excellent capacity retention of 97.5% with high Coulombic efficiency of 99.6% after 300 cycles at 30 °C.

  18. Plasma-ion Induced Sputtering and Heating of Titan's Atmosphere

    Science.gov (United States)

    Johnson, R. E.; Tucker, O. J.

    2007-05-01

    Titan is unique among the outer solar system icy satellites in having an atmosphere with a column density about ten times that of the Earth's atmosphere and an atmospheric mass to solid mass ratio comparable to that of Venus. Atmospheres equivalent in size to that at Titan would have been removed from the icy Galilean satellites by the plasma trapped in the Jovian magnetosphere (Johnson 2004). Therefore, the use of Cassini data to determine the present erosion rate of Titan's atmosphere provides an important end point for studying the erosion and heating of planetary and satellite atmospheres by an ambient plasma. In this paper we describe the deposition of energy, the erosion and the expansion of the upper atmosphere of Titan using Direct Simulation Monte Carlo models (Shematovich et al. 2003; Michael et al. 2005; Michael and Johnson 2005). These calculations are used to calibrate semi-empirical models of atmospheric sputtering (Johnson 1994) that are used to interpret Cassini data at Titan. Using a number of plasma conditions, the temperature and density vs. altitude above the exobase and the rate of escape are calculated. References: Johnson, R.E. "Plasma-induced Sputtering of an Atmosphere" in Space Science Reviews 69 215-253 (1994). Johnson. R.E., " The magnetospheric plasmadriven evolution of satellite atmospheres" Astrophys. J. 609, L99-L102 (2004). Michael, M. and R.E. Johnson, "Energy deposition of pickup ions and heating of Titan's atmosphere", Planetary & Space Sci.53, 1510-1514 (2005). Michael M., R.E. Johnson, F. Leblanc, M. Liu, J.G. Luhmann, and V.I. Shematovich, "Ejection of nitrogen from Titan's atmosphere by magnetospheric ions and pick-up ions", Icarus 175, 263-267 (2005). Shematovich, V.I., R.E. Johnson, M. Michael, and J.G. Luhmann, "Nitrogen loss from Titan", JGR 108, No. E8, 5087, doi:10.1029/2003JE002094 (2003).

  19. Swift heavy ion induced modifications of optical and microstructural properties of silver-fullerene C60 nanocomposite

    International Nuclear Information System (INIS)

    In this paper, we study the optical and microstructural properties of silver-fullerene C60 nanocomposite and their modifications induced by swift heavy ion irradiation. Silver nanoparticles embedded in fullerene C60 matrix were synthesized by co-deposition of silver and fullerene C60 by thermal evaporation. The nanocomposite thin films were irradiated by 120 MeV Ag ions at different fluences ranging from 1 x 1012 to 3 x 1013 ions/cm2. Optical absorption studies revealed that the surface plasmon resonance of Ag nanoparticles showed a blue shift of ∼49 nm with increasing ion fluence up to 3 x 1013 ions/cm2. Transmission electron microscopy and Rutherford backscattering spectroscopy were used to quantify particle size and metal atomic fraction in the nanocomposite film. Growth of Ag nanoparticles was observed with increasing ion fluence. Raman spectroscopy was used to understand the effect of heavy ion irradiation on fullerene matrix. The blue shift in plasmonic wavelength is explained by the transformation of fullerene C60 matrix into amorphous carbon.

  20. Robotic-based carbon ion therapy and patient positioning in 6 degrees of freedom: setup accuracy of two standard immobilization devices used in carbon ion therapy and IMRT

    International Nuclear Information System (INIS)

    To investigate repositioning accuracy in particle radiotherapy in 6 degrees of freedom (DOF) and intensity-modulated radiotherapy (IMRT, 3 DOF) for two immobilization devices (Scotchcast masks vs thermoplastic head masks) currently in use at our institution for fractionated radiation therapy in head and neck cancer patients. Position verifications in patients treated with carbon ion therapy and IMRT for head and neck malignancies were evaluated. Most patients received combined treatment regimen (IMRT plus carbon ion boost), immobilization was achieved with either Scotchcast or thermoplastic head masks. Position corrections in robotic-based carbon ion therapy allowing 6 DOF were compared to IMRT allowing corrections in 3 DOF for two standard immobilization devices. In total, 838 set-up controls of 38 patients were analyzed. Robotic-based position correction including correction of rotations was well tolerated and without discomfort. Standard deviations of translational components were between 0.5 and 0.8 mm for Scotchcast and 0.7 and 1.3 mm for thermoplastic masks in 6 DOF and 1.2 - 1.4 mm and 1.0 - 1.1 mm in 3 DOF respectively. Mean overall displacement vectors were between 2.1 mm (Scotchcast) and 2.9 mm (thermoplastic masks) in 6 DOF and 3.9 - 3.0 mm in 3 DOF respectively. Displacement vectors were lower when correction in 6 DOF was allowed as opposed to 3 DOF only, which was maintained at the traditional action level of > 3 mm for position correction in the pre-on-board imaging era. Setup accuracy for both systems was within the expected range. Smaller shifts were required when 6 DOF were available for correction as opposed to 3 DOF. Where highest possible positioning accuracy is required, frequent image guidance is mandatory to achieve best possible plan delivery and maintenance of sharp gradients and optimal normal tissue sparing inherent in carbon ion therapy

  1. Electron and ion induced electron emission from metals and insulators

    CERN Document Server

    Steinbatz, M

    2001-01-01

    gradually exposed to oxygen as an experimental probe. The experimental data are fitted with an analytical model, that is able to describe the observed kinetics. The fit parameters give absolute values of sticking probabilities and of surface reaction rates. During oxidation of aluminum and magnesium also spontaneous emission of electrons (exoelectrons) is observed. This effect is quantitatively studied for different oxygen partial pressures. The experimental data also indicate a significant influence of the surface morphology on the exoemission process. An important consequence of atomic collisions in solids is ionization leading to electron ejection from the target atoms with subsequent migration through the solid. A certain fraction of these electrons finally reaches the surface and is ejected into vacuum. A standard measurement of this phenomenon is the observation of the particle (electron, ion) induced electron emission yield g, defined as the average number of ejected electrons per incoming projectile. ...

  2. Ion beam induced luminescence on white inorganic pigments for paintings

    International Nuclear Information System (INIS)

    Ion beam induced luminescence (IBIL) has been used for studying the emission features and the radiation hardness of white pigments. In particular, ZnO, gypsum and basic lead sulphate pigments have been analyzed with a 3.0 MeV H+ beam at the AGLAE Louvre laboratory. The same pigments mixed with different binders have been also analyzed on a canvas, in order to evaluate the contribution of the binders both to the IBIL spectra and to the radiation hardness. It turns out that the binder affects both the IBIL spectra and the radiation hardness of pigments when the emission bands are related to point defects, as occurs for ZnO

  3. Ion beam induced luminescence on white inorganic pigments for paintings

    Science.gov (United States)

    Quaranta, A.; Dran, J. C.; Salomon, J.; Tonezzer, M.; Scian, C.; Beck, L.; Carturan, S.; Maggioni, G.; Della Mea, G.

    2008-05-01

    Ion beam induced luminescence (IBIL) has been used for studying the emission features and the radiation hardness of white pigments. In particular, ZnO, gypsum and basic lead sulphate pigments have been analyzed with a 3.0 MeV H+ beam at the AGLAE Louvre laboratory. The same pigments mixed with different binders have been also analyzed on a canvas, in order to evaluate the contribution of the binders both to the IBIL spectra and to the radiation hardness. It turns out that the binder affects both the IBIL spectra and the radiation hardness of pigments when the emission bands are related to point defects, as occurs for ZnO.

  4. Inclusive spectra of stripping reactions induced by heavy ions

    International Nuclear Information System (INIS)

    The spectra of inclusive transfer reactions induced by heavy ions and leading to continuum final states show high-lying broad resonancelike structures superimposed on a large continuum. Recent experimental spectra for neutron stripping on targets in the lead region are analyzed by the Bonaccorso and Brink single-particle transfer model. The results of the calculation suggest that the structures are due to the population of high-spin single-particle states which are unbound and mix with the underlying states giving rise to a broadening of the peak. The main characteristics of the spectra are reproduced. Moreover, an estimate of the elastic and inelastic breakup contributions to the inclusive spectra is given

  5. Ion-beam-induced amorphous structures in silicon carbide

    International Nuclear Information System (INIS)

    Atomistic structure of ion-beam-induced amorphous silicon carbide (a-SiC) has been investigated by cross-sectional transmission electron microscopy. The electron intensities of halo patterns recorded on imaging plates were digitized quantitatively to extract reduced interference functions. We demonstrated the relationship between maximum scattering vector (Qmax) measured in scattering experiments and the resolution of the corresponding pair-distribution function by changing Qmax values from 160 to 230 nm-1. The results revealed that the C-C peak becomes broadened and eventually a shoulder as the Qmax value becomes shorter, indicating that Qmax values of -1 measured in previous studies are not enough to detect C-C homonuclear bonds in a-SiC. We are the first to reveal the existence of C-C and Si-Si homonuclear bonds in a-SiC using a diffraction technique

  6. Multicharged Ion-induced simple molecule fragmentation dynamics

    International Nuclear Information System (INIS)

    The aim of this work is to study the dynamics of swift multicharged ion-induced fragmentation of diatomic (CO) and triatomic (CO2) molecules. Performed at the GANIL facility, this study used the Recoil Ion Momentum Spectroscopy technique (RIMS), which consists of a time-of-flight mass spectrometer, coupled with a multi-hit capability position sensitive detector (delay line anode). The high-resolution measurement of the kinetic energy distribution released (KER) during the CO fragmentation points out the limitation of the Coulomb Explosion Model, revealing, for example, the di-cation CO2+ electronic state contribution in the case of C+/O+ fragmentation pathway. Furthermore, the multi-ionization cross section dependence with the orientation of the internuclear axis of CO is compared with a geometrical model calculation. Finally, different behaviours are observed for the dissociation dynamics of a triatomic molecule (CO2). While triple ionization leads mainly to a synchronous concerted fragmentation dynamics, a weak fraction of dissociating molecule follows a sequential dynamics involving CO2+ metastable states. In the case of double ionization, (CO2)2+ di-cation dissociation dynamics is asynchronously concerted and has been interpreted using a simple model involving an asymmetrical vibration of the molecule. (author)

  7. Ion Induced Changes in Phosphoinositide Monolayers at Phisiological Concentrations

    Science.gov (United States)

    Kazadi Badiambile, Adolphe; Forstner, Martin

    2013-03-01

    Phosphoinositides (PIPs) play a crucial role in many cellular process that occur at the plasma membrane such as calcium release, exocytosis or endocytosis. In order to specifically regulate these functions PIPs must segregate in pools at the plasma membrane. A possible mechanism that could induce and regulate such organization of phosphoinositides is their interaction with bivalent cations. Understanding the physicochemical mechanism that can regulate membrane structure is a crucial step in the development of adaptive biomimetic membrane systems. Using Langmuir monolayers, we investigated the effect of calcium and magnesium on the surface pressure-area/lipid isotherm of monolayer of phosphatidylinositol (PI), phosphatidylinositol bisphosphate (PIP2), dioleoylphosphatidylglycerol (DOPG) and palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). It is found that the decrease of area per lipid, i.e. the increase in aggregation, is mostly dependent on the lipid's head group charge but ion specific. In addition, we discuss changes in free energy and compressibility of these monolayer-ion systems. NSF

  8. Carbon nanotubes as masks against ion irradiation: An insight from atomistic simulations

    International Nuclear Information System (INIS)

    Recent experiments show that carbon nanotubes can be used as masks against ion irradiation to make metallic nanowires of a few nanometers in width. In order to ascertain the limitations of this technique, we use molecular dynamics and simulate ion irradiation of multiwalled nanotubes. We derive an equation which for a given nanowire material allows one to estimate the theoretical limit on the minimum width of the wire which can be made using this technique

  9. Regularities of ion-electron emission of one-dimensional carbon-based composite materials

    International Nuclear Information System (INIS)

    The temperature dependence of ion-electron emission yield, γ(T), developed topography and surface crystalline structure of carbon-based composite material KUP- VM under high-fluence 30 keV N2+ ion irradiation has been studied. Complex two-stage nature of γ(T) dependence is formed due to the process of dynamic annealing of the radiation damage in structural components of composite material

  10. Electron impact excitation of carbon-like ions: An assessment of the available theoretical data

    International Nuclear Information System (INIS)

    Electron impact excitation of ions of the carbon-like isoelectronic sequence from O III to Fe XXI is reviewed starting from previous critical compilations. Comparisons between results obtained from the distorted-wave and the R-matrix methods have been made. The effective collision strengths have been compared along the sequence. The isoelectronic trends should be useful in interpolating data for ions where no specific calculations are available. 24 refs., 23 figs., 6 tabs

  11. Ion beam induced adhesion improvement of metal layers - a comparative study on composite layers

    International Nuclear Information System (INIS)

    The adhesion of thin layers of metals like Al, Cu, Cr, Ti etc. on polymer, ceramic or composite substrates is of great importance for microelectronics (printed circuits, packaging), and materials science. Therefore investigations on the adhesion improvement of copper on high temperature thermoplasts, carbon fibre reinforced polymers (CFK) and pure carbon by ion bombardment were undertaken. Ion beam mixing as well as ion beam assisted deposition (IBAD) was applied. It was shown that the electronic stopping power is the most important parameter for adhesion in the case of ion beam mixing by non-reactive ions. Reactive ions, especially metals, add an important chemical effect when stopped near the interface. IBAD Cu-layers have only good adhesion properties when prepared by low energy ion bombardment or with reactive intermediate layers. ((orig.))

  12. Encapsulation of α-Particle–Emitting 225Ac3+ Ions Within Carbon Nanotubes

    Science.gov (United States)

    Matson, Michael L.; Villa, Carlos H.; Ananta, Jeyarama S.; Law, Justin J.; Scheinberg, David A.; Wilson, Lon J.

    2016-01-01

    225Ac3+ is a generator of α-particle–emitting radionuclides with 4 net α-particle decays that can be used therapeutically. Targeting 225Ac3+ by use of ligands conjugated to traditional bifunctional chelates limits the amount of 225Ac3+ that can be delivered. Ultrashort, single-walled carbon nanotubes (US-tubes), previously demonstrated as sequestering agents of trivalent lanthanide ions and small molecules, also successfully incorporate 225Ac3+. Methods Aqueous loading of both 225Ac3+ ions and Gd3+ ions via bath sonication was used to construct 225Ac@gadonanotubes (225Ac@GNTs). The 225Ac@GNTs were subsequently challenged with heat, time, and human serum. Results US-tubes internally loaded with both 225Ac3+ ions and Gd3+ ions show 2 distinct populations of 225Ac3+ ions: one rapidly lost in human serum and one that remains bound to the US-tubes despite additional challenge with heat, time, and serum. The presence of the latter population depended on cosequestration of Gd3+ and 225Ac3+ ions. Conclusion US-tubes successfully sequester 225Ac3+ ions in the presence of Gd3+ ions and retain them after a human serum challenge, rendering 225Ac@GNTs candidates for radioimmunotherapy for delivery of 225Ac3+ ions at higher concentrations than is currently possible for traditional ligand carriers. PMID:25931476

  13. The first French randomized prospective study of the economic and medical benefit of carbon ion radiotherapy

    International Nuclear Information System (INIS)

    Carbon ion therapy is an innovative radiotherapy modality for non-operable radio-resistant or resected cancers. Its efficiency is due to improved ballistic accuracy and biological efficiency. The authors present the first phase III study of carbon ion therapy in France. This technique concerns some sarcomas and adenoid cystic carcinomas of head and neck. The authors indicate the possible treatment procedures (doses, sessions) for the different types of cancers, and how the study is to be performed (number of patients, randomization, and multicentre approach). Short communication

  14. Oxidation processes on conducting carbon additives for lithium-ion batteries

    KAUST Repository

    La Mantia, Fabio

    2012-11-21

    The oxidation processes at the interface between different types of typical carbon additives for lithium-ion batteries and carbonates electrolyte above 5 V versus Li/Li+ were investigated. Depending on the nature and surface area of the carbon additive, the irreversible capacity during galvanostatic cycling between 2.75 and 5.25 V versus Li/Li+ could be as high as 700 mAh g-1 (of carbon). In the potential region below 5 V versus Li/Li+, high surface carbon additives also showed irreversible plateaus at about 4.1-4.2 and 4.6 V versus Li/Li+. These plateaus disappeared after thermal treatments at or above 150 °C in inert gas. The influence of the irreversible capacity of carbon additives on the overall performances of positive electrodes was discussed. © 2012 Springer Science+Business Media Dordrecht.

  15. Effects of low-dose carbon ion irradiation on the proliferation of splenocytes and the concentration of interferon in mice

    Science.gov (United States)

    Li, Ning

    AIM: To investigate the changes in the proliferation response of splenic lymphocytes and the concentration of serum interferon (IFN-γ) in mice induced by low doses carbon ion irradiation. METHODS: The experiment was carried out in the laboratory of physical medicine, Institute of Modern Physics, Chinese Academy of Sciences in November 2006. 1. Thirty Kunming mice were randomly divided into five groups with six animals in each group and irradiated with 0, 0.01, 0.03, 0.05 and 0.10 Gy carbon ion at Heavy Ion Research Facility Laboratory of Lanzhou. Twenty-four hours after irradiation, the eyeballs of mice were taken out under anesthesia and blood was harvested. 2. The concentration of IFN-γ in serum was detected by ELISA kit. After the mice were executed, the spleen was harvested under sterile condition to prepare spleen mononuclear cell suspension. The effects of concanavalin A(ConA) and lipopolysaccharide(LPS) on the proliferations of mononuclear cells was tested by MTT assay. RESULTS: All thirty mice were involved in the result analysis. 1. The concentration of IFN-γ in serum remarkably increased after irradiation with 0.01 Gy and 0.03 Gy compared with that in controls (p<0.05). However, the concentration of IFN-γ decreased after irradiation with 0.05 Gy and 0.1 Gy. 2. Compared with control group, the proliferation of T lymphocytes induced by ConA and B lymphocytes induced by LPS remarkably increased after irradiation with 0.01 Gy (p<0.001) and the effect was of significant difference compared with that of 0.03 Gy (p<0.01). The irradiation with 0.05 Gy presented an inhibition to the proliferation of splenic lymphocytes. This inhibition was also obvious when irradiated with 0.10 Gy. CONCLUSION: 0.01 Gy and 0.03 Gy carbon ion irradiation can stimulate the proliferation of splenocytes, induce the secretion of IFN-γ and, in consequence, enhance the immune function.

  16. MnO-carbon hybrid nanofiber composites as superior anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    MnO-carbon hybrid nanofiber composites are fabricated by electrospinning polyimide/manganese acetylacetonate precursor and a subsequent carbonization process. The composition, phase structure and morphology of the composites are characterized by scanning and transmission electron microscopy, X-ray diffraction and thermogravimetric analysis. The results indicate that the composites exhibit good nanofibrous morphology with MnO nanoparticles uniformly encapsulated by carbon nanofibers. The hybrid nanofiber composites are used directly as freestanding anodes for lithium-ion batteries to evaluate their electrochemical properties. It is found that the optimized MnO-carbon nanofiber composite can deliver a high reversible capacity of 663 mAh g−1, along with excellent cycling stability and good rate capability. The superior performance enables the composites to be promising candidates as an anode alternative for high-performance lithium-ion batteries

  17. Two-Dimensional Porous Carbon: Synthesis and Ion-Transport Properties.

    Science.gov (United States)

    Zheng, Xiaoyu; Luo, Jiayan; Lv, Wei; Wang, Da-Wei; Yang, Quan-Hong

    2015-09-23

    Their chemical stability, high specific surface area, and electric conductivity enable porous carbon materials to be the most commonly used electrode materials for electrochemical capacitors (also known as supercapacitors). To further increase the energy and power density, engineering of the pore structures with a higher electrochemical accessible surface area, faster ion-transport path and a more-robust interface with the electrolyte is widely investigated. Compared with traditional porous carbons, two-dimensional (2D) porous carbon sheets with an interlinked hierarchical porous structure are a good candidate for supercapacitors due to their advantages in high aspect ratio for electrode packing and electron transport, hierarchical pore structures for ion transport, and short ion-transport length. Recent progress on the synthesis of 2D porous carbons is reported here, along with the improved electrochemical behavior due to enhanced ion transport. Challenges for the controlled preparation of 2D porous carbons with desired properties are also discussed; these require precise tuning of the hierarchical structure and a clarification of the formation mechanisms. PMID:26207982

  18. The Radiation Enhancement of 15 nm Citrate-Capped Gold Nanoparticles Exposed to 70 keV/μm Carbon Ions.

    Science.gov (United States)

    Liu, Yan; Liu, Xi; Jin, Xiaodong; He, Pengbo; Zheng, Xiaogang; Ye, Fei; Chen, Weiqiang; Li, Qiang

    2016-03-01

    Radiotherapy is an important modality for tumor treatment. The central goal of radiotherapy is to deliver a therapeutic dose to the tumor as much as possible whilst sparing the surrounding normal tissues. On one hand, heavy ion radiation induces maximum damage at the end of the track (called the Bragg Peak). Hadron therapy based on heavy ions is considered superior to conventional X-rays and γ-rays radiations for tumors sited in sensitive tissues, childhood cases and radioresistant cancers. On the other hand, radiation sensitizers enhanced the radiation effects in tumors by increasing the dose specifically to the tumor cells. Recently, the use of gold nanoparticles as potential tumor selective radio-sensitizers has been proposed as a breakthrough in radiotherapy with conventional radiations. The enhanced radiation effect of heavy ions in tumor by using gold nanoparticles as radio-sensitizer may provide alternative in hadron therapy. In this study, we investigated the radiosensitizing effects of carbon ions with a linear energy transfer of 70 keV/μm in the presence of 15 nm citrate-capped AuNPs. The existing of AuNPs resulted in 5.5-fold enhancement in hydroxyl radical production and 24.5% increment in relative biological effectiveness (RBE) values for carbon-ion-irradiated HeLa cells. The study indicated gold nanoparticles can be used as potential radio-sensitizer in carbon ions therapy. PMID:27455642

  19. Operation of KeiGM for the carbon ion therapy facility at Gunma University

    International Nuclear Information System (INIS)

    Carbon-ion radiotherapy is being carried out at Gunma University Heavy Ion Medical Centre (GHMC) since March 2010. A compact electron cyclotron resonance ion source (ECRIS) for GHMC, so-called KeiGM, supplies carbon 4+ ions for treatment. The general structure of KeiGM was copied from a prototype compact source, so-called Kei2. Based on experimental studies for production of carbon 4+ ions with a 10 GHz ECR source at the Heavy Ion Medical Accelerator in Chiba (HIMAC), so-called NIRS-ECR, the field distribution of the mirror magnet for Kei2 and KeiGM was designed. A microwave source with the traveling-wave-tube (TWT) was adopted for KeiGM, with a frequency range and maximum power of 9.75 - 10.25 GHz and 750 W, respectively. The KeiGM was installed in the GHMC facility in December 2008. The paper is followed by the associated poster. (authors)

  20. Magnetic-field-induced diameter-selective synthesis of single-walled carbon nanotubes.

    Science.gov (United States)

    Su, Yanjie; Zhang, Yaozhong; Wei, Hao; Zhang, Liling; Zhao, Jiang; Yang, Zhi; Zhang, Yafei

    2012-03-01

    We report a facile and scalable approach to synthesize single-walled carbon nanotubes (SWNTs) with selected diameter distribution by applying a magnetic field perpendicular to the electric field in the arc plasma region. It is found that this magnetic field-induced diameter-selectivity strategy enables the control of the SWNTs with different diameter distributions in different regions, and the diameter-selective efficiency could be enhanced by modifying the direction of magnetic field. Our results indicate that the motions of the catalysts with different particle sizes, positive carbon ions and electrons are significantly influenced by the magnetic field and electromagnetic force, resulting in the different nucleation and growth processes of SWNTs due to the collective interactions between the magnetic field and arc plasma. This approach would enable a viable route towards the synthesis of SWNTs with desired diameter through the tuning of arc parameters in the arc discharge process. PMID:22301844

  1. Determination of total dissolved inorganic carbon in freshwaters by reagent-free ion chromatography.

    Science.gov (United States)

    Polesello, Stefano; Tartari, Gabriele; Giacomotti, Paola; Mosello, Rosario; Cavalli, Silvano

    2006-06-16

    Studies of inorganic carbon cycle in natural waters provide important information on the biological productivity and buffer capacity. Determination of total inorganic carbon, alkalinity and dissolved carbon dioxide gives an indication of the balance between photosynthesis and respiration by biota, both within the water column and sediments, and carbon dioxide transfers from the water column to the atmosphere. There are few methods to measure and distinguish the different forms of inorganic carbon, but all require a measure or an indirect quantification of total inorganic carbon. A direct measurement of TIC in water is made possible by the introduction of electrolytic generated hydroxide eluent in ion chromatography which allows to detect a chromatographic peak for carbonate. The advantage of this method is that all the inorganic forms of carbon are converted in carbonate at eluent pH and can be detected as a single peak by conductivity detection. Repeatability of carbonate peak was evaluated at different levels from 0.02 to 6 mequiv.l(-1) both in high purity water and in real samples and ranged from 1 to 9%. The calibration curve was not linear and has to be fitted by a quadratic curve. Limit of detection was estimated to be 0.02 mequiv.l(-1). Accuracy has been estimated by comparing ion chromatography method with total inorganic carbon calculated from alkalinity and pH. The correlation between the two methods was good (R(2)=0.978, n=141). The IC method has been applied to different typologies of surface waters (alpine and subalpine lakes and rivers) characterised by different chemical characteristics (alkalinity from 0.05 to 2 mequiv.l(-1) and pH from 6.7 to 8.5) and low total organic carbon concentrations. This analytical method allowed to describe the distribution of TIC along the water column of two Italian deep lakes. PMID:16620857

  2. Coaxial carbon/metal oxide/aligned carbon nanotube arrays as high-performance anodes for lithium ion batteries.

    Science.gov (United States)

    Lou, Fengliu; Zhou, Haitao; Tran, Trung Dung; Melandsø Buan, Marthe Emelie; Vullum-Bruer, Fride; Rønning, Magnus; Walmsley, John Charles; Chen, De

    2014-05-01

    Coaxial carbon/metal oxide/aligned carbon nanotube (ACNT) arrays over stainless-steel foil are reported as high-performance binder-free anodes for lithium ion batteries. The coaxial arrays were prepared by growth of ACNTs over stainless-steel foil followed by coating with metal oxide and carbon. The carbon/manganese oxide/ACNT arrays can deliver an initial capacity of 738 mAh g(-1) with 99.9 % capacity retention up to 100 cycles and a capacity of 374 mAh g(-1) at a high current density of 6000 mA g(-1). The external carbon layer was recognized as a key component for high performance, and the mechanism of performance enhancement was investigated by electrochemical impedance spectroscopy, electron microscopy, and X-ray diffraction analysis. The layer increases rate capability by enhancing electrical conductivity and maintaining a low mass-transfer resistance and also improves cyclic stability by avoiding aggregation of metal-oxide particles and stabilizing the solid electrolyte interface. The resultant principle of rational electrode design was applied to an iron oxide-based system, and similar improvements were found. These coaxial nanotube arrays present a promising strategy for the rational design of high-performance binder-free anodes for lithium ion batteries. PMID:24578068

  3. Stability and kinetics of uranyl ion complexation by macrocycles in propylene carbonate

    International Nuclear Information System (INIS)

    A thermodynamic study of uranyl ion complexes formation with different macrocyclic ligands was realized in propylene carbonate as solvent using spectrophotometric and potentiometric techniques. Formation kinetics of two UO2 complexes: a crown ether (18C6) and a coronand (22) was studied by spectrophotometry in propylene carbonate with addition of tetraethylammonium chlorate 0.1M at 250C. Possible structures of complexes in solution are discussed

  4. Adsorption of rare earth ions using carbonized polydopamine nano carbon shells

    Institute of Scientific and Technical Information of China (English)

    孙晓琦; LUO Huimin; Shannon M. Mahurin; LIU Rui; HOU Xisen; DAI Sheng

    2016-01-01

    Herein we reported the structure effects of carbon nano-shells prepared by the carbonization of polydopamine for the ad-sorption of rare earth elements (REEs) for the first time. Solid carbon spheres, 60 nm carbon shells and 500 nm carbon shells were prepared and evaluated for adsorption and desorption of REEs. The adsorption performance of carbon nano-shells for REEs was far superior to the solid carbon spheres. In addition, the effect of acidity on the adsorption and desorption properties was discussed. The good adsorption performance of the carbon nano-shells could be attributed to their pore structure, specific surface area, and the pres-ence of both amine and carbonyl groups from the grafted dopamine.

  5. Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries.

    Science.gov (United States)

    Badi, Nacer; Erra, Abhinay Reddy; Hernandez, Francisco C Robles; Okonkwo, Anderson O; Hobosyan, Mkhitar; Martirosyan, Karen S

    2014-01-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for

  6. Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries

    Science.gov (United States)

    Badi, Nacer; Erra, Abhinay Reddy; Hernandez, Francisco C. Robles; Okonkwo, Anderson O.; Hobosyan, Mkhitar; Martirosyan, Karen S.

    2014-07-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for

  7. Decomposition of cyclohexane ion induced by intense femtosecond laser fields by ion-trap time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Decomposition of cyclohexane cations induced by intense femtosecond laser fields at the wavelength of 800 nm is investigated by ion-trap time-of-flight mass spectrometry in which cyclohexane cations C6H12+ stored in an ion trap are irradiated with intense femtosecond laser pulses and the generated fragment ions are recorded by time-of-flight mass spectrometry. The various fragment ion species, C5Hn+ (n = 7, 9), C4Hn+ (n = 5–8), C3Hn+ (n = 3–7), C2Hn+ (n = 2–6), and CH3+, identified in the mass spectra show that decomposition of C6H12+ proceeds efficiently by the photo-irradiation. From the laser intensity dependences of the yields of the fragment ion species, the numbers of photons required for producing the respective fragment ions are estimated

  8. Thermal management of a Li-ion battery using carbon fiber-PCM composites

    International Nuclear Information System (INIS)

    A combination of latent and sensible heat capabilities has made phase change materials (PCMs) very useful in a variety of heat transfer applications. The main purpose of using the phase change material in lithium-ion (Li-ion) battery thermal management systems (BTMs) is to mitigate the excessive temperature rise in the cells and to create uniform temperature distribution within the battery pack. In this work, carbon fibers were added to a PCM to enhance its heat transfer potentials. Various strategies were adopted to manage temperature distribution around a single AA-battery-like simulator. The effects of carbon fiber size and weight percent within the PCM on thermal performance were studied. Experimental results have indicated that a mixture of PCM with 2-mm-long carbon fibers and mass percentage of 0.46% showed the best thermal performance for which the maximum temperature rise in the battery simulator can be reduced by up to 45%. - Graphical abstract: The schematic of the experimental setup and data acquisition system (1-power source 2-container 3-battery module 4-thermocouples 5-temperature indicator 6-data acquisition system). - Highlights: • Thermal performance of a Li-ion battery simulator is studied in the presence of PCM. • The effect of carbon fiber on heat transfer enhancement is examined. • Better thermal management can be achieved by the presence of carbon fiber in PCM. • Both carbon fiber mass fraction and length play crucial role in thermal management

  9. Blister formation in tungsten by hydrogen and carbon mixed ion beam irradiation

    International Nuclear Information System (INIS)

    Blister formation in tungsten has been studied by mixed carbon and hydrogen ion beam irradiation. The beam ion energies were 1.0 keV and 300 eV, and the fluence was in the range of 1024-1025 ions m-2. It was found that a little amount of carbon impurity in the beam affected blister formation. A large number of blisters with various sizes were observed on the surface of tungsten at 653 K when the carbon concentration was more than 0.35%. When the carbon concentration was 0.11%, no blisters larger than 1.0 μm were observed. When the carbon concentration was 2.35%, a carbon layer developed on the tungsten surface, and again, no blisters were observed. The effect of target temperature on blister formation was also investigated: the sizes and numbers of the blisters were the largest when the tungsten was irradiated at 653 K; when the sample was irradiated at 388 or 873 K, no blisters larger than 1.0 μm were observed

  10. Computational Evaluation of Amorphous Carbon Coating for Durable Silicon Anodes for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jeongwoon Hwang

    2015-10-01

    Full Text Available We investigate the structural, mechanical, and electronic properties of graphite-like amorphous carbon coating on bulky silicon to examine whether it can improve the durability of the silicon anodes of lithium-ion batteries using molecular dynamics simulations and ab-initio electronic structure calculations. Structural models of carbon coating are constructed using molecular dynamics simulations of atomic carbon deposition with low incident energies (1–16 eV. As the incident energy decreases, the ratio of sp2 carbons increases, that of sp3 decreases, and the carbon films become more porous. The films prepared with very low incident energy contain lithium-ion conducting channels. Also, those films are electrically conductive to supplement the poor conductivity of silicon and can restore their structure after large deformation to accommodate the volume change during the operations. As a result of this study, we suggest that graphite-like porous carbon coating on silicon will extend the lifetime of the silicon anodes of lithium-ion batteries.

  11. Charge state effect on Si K X-ray emission induced by Iq+ ions impacting

    Science.gov (United States)

    Lei, Yu; Zhao, Yongtao; Cheng, Rui; Zhou, Xianming; Sun, Yuanbo; Wang, Xing; Wang, Yuyu; Ren, Jieru; Li, Yongfeng; Yu, Yang; Liu, Shidong; Xu, Ge

    2014-04-01

    K X-ray emission of Si induced by Iq+ (q=20, 22, 25) ion impact has been investigated. The results show a much higher intensity of X-ray emission for I25+ ions bombardment compared to I20+ and I22+ ions. The experimental data are explained within the framework of 3dπ, δ-3dσ rotational coupling.

  12. Study of ion-induced optical emission spectra in sputtering of scandium target

    International Nuclear Information System (INIS)

    Ion-induced optical emission spectra excited by bombardment of scandium target with 40 keV Xe+ ions are studied in spectral region of 380-600nm. Excitation efficiencies of atomic energy levels in sputtering processes and in plasma discharge are compared. Possible new mechanisms of electron excitation in ion sputtering of metals are discussed. (author)

  13. Thin film Li-Ion batteries with carbon anode

    Czech Academy of Sciences Publication Activity Database

    Merta, J.; Bludská, Jana; Jakubec, Ivo

    Brno: University of Technology Brno, 2003, s. 37-40. ISBN 80-214-2298-X. [Advanced Batteries and Accumulators /4./. Brno (CZ), 15.06.2003-19.06.2003] Institutional research plan: CEZ:AV0Z4032918 Keywords : carbon anode Subject RIV: CA - Inorganic Chemistry

  14. Generation of MeV carbon and fluorine ions by subnanosecond laser pulses

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Velyhan, Andriy; Jungwirth, Karel; Krouský, Eduard; Láska, Leoš; Rohlena, Karel; Pfeifer, Miroslav; Ullschmied, Jiří

    Paris : European Physical Society, 2008 - (Lalousis, P.; Moustaizis, S.), P4.133/1-P4.133/4 ISBN 2-914771-52-5. - (ECA. 32D). [EPS Plasma Physics Conference /35./. Hersonissos (GR), 09.06.2008-13.06.2008] R&D Projects: GA MŠk(CZ) LC528; GA AV ČR IAA100100715 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser ion sources * carbon ions * fluorine ions * effective accelerating voltage Subject RIV: BH - Optics, Masers, Lasers

  15. Optical and Scratch Resistant Properties of Diamondlike Carbon Films Deposited with Single and Dual Ion Beams

    Science.gov (United States)

    Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

    1993-01-01

    Amorphous diamond-like carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance, frictional, and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

  16. The analysis of gene expression induced by heavy-ions

    International Nuclear Information System (INIS)

    Although mutations and deletions of the p53 tumor suppressor gene can lead to resistance to low-linear energy transfer (LET) radiation, high-LET radiation induces efficiently cell lethality and apoptosis regardless of p53 gene status in cancer cells. In other words, it might be not necessary to check the p53 gene status of tumors as a predictive indicator for this high-LET radiation therapy. The aim of this study is to clarify the specific p53-independent apoptosis-related genes and proteins induced by high-LET radiation. Recently, it has been suggested that the induction of p53-independent apoptosis takes place through the activation of Caspase-9 which results in the cleavage of Caspase-3 and PARP. In this report, we examined whether high-LET radiation depresses the survival signals such as Akt which is well known to inhibit Caspase-9. Human gingival cancer cells (Ca9-22 cells) harboring mutated p53 gene were irradiated with X-rays or Fe-ion beams (200 KeV/μm) with 2 Gy. Protein was extracted 6 h after irradiation. The cellular amount of Akt was analyzed by Western blotting. When the cells were irradiated with high-LET radiation, Akt-related proteins were decreased. These results suggest that high-LET radiation enhances apoptosis by activation of Caspase-9 through depression of Akt even in the presence of mp53. (author)

  17. Mitochondrial dysfunction induced by different concentrations of gadolinium ion.

    Science.gov (United States)

    Zhao, Jie; Zhou, Zhi-Qiang; Jin, Jian-Cheng; Yuan, Lian; He, Huan; Jiang, Feng-Lei; Yang, Xiao-Gang; Dai, Jie; Liu, Yi

    2014-04-01

    Gadolinium-based compounds are the most widely used paramagnetic contrast agents in magnetic resonance imaging on the world. But the tricationic gadolinium ion (Gd(3+)) could induce cell apoptosis probably because of its effects on mitochondria. Until now, the mechanism about how Gd(3+) interacts with mitochondria is not well elucidated. In this work, mitochondrial swelling, collapsed transmembrane potential and decreased membrane fluidity were observed to be important factors for mitochondrial permeability transition pore (mtPTP) opening induced by Gd(3+). The protection effect of CsA (Cyclosporin A) could confirm high concentration of Gd(3+) (500 μM) would trigger mtPTP opening. Moreover, mitochondrial outer membrane breakdown and volume expansion observed clearly by transmission electron microscopy and the release of Cyt c (Cytochrome c) could explain the mtPTP opening from another aspect. In addition, MBM(+) (monobromobimane(+)) and DTT (dithiothreitol) could protect thiol (-SH) groups from oxidation so that the toxicity of Gd(3+) might be resulted from the chelation of -SH of membrane proteins by free Gd(3+). Gd(3+) could inhibit the initiation of mitochondrial membrane lipid peroxidation, so it might interact with anionic lipids too. These findings will highly contribute to the safe applications of Gd-based agents. PMID:24321333

  18. A Facile Potential-Induced In-Situ Ion Removal Trick: Fabrication of High-Selective Ion-Imprinted Film for Trivalent Yttrium Ion Separation

    International Nuclear Information System (INIS)

    Highlights: • Y3+ ion imprinted FCN/PPy film was fabricated successfully by using UPEP method. • The resulting Y3+-FCN/PPy film shows excellent ESIX performance for Y3+ ion. • A complicated Y3+ ion exchange process in different E-IIPs is studied by EQCM. • Two distinct stages during the adsorption process of Y3+ into the E-IIPs are characterized. - ABSTRACT: A novel electroactive trivalent yttrium ions imprinted polymer film composed of ferricyanide embedded conductive polypyrrole (FCN/PPy) is fabricated by using a facile unipolar pulse electropolymerization (UPEP) method. The imprinted Y3+ ions can be removed in situ from the growing film by tactfully inducing potential oscillation on the film electrode based on the electric repulsion. Cyclic Voltammetry (CV) measurements combined with Electrochemical Quartz Crystal Microbalance (EQCM) are applied to characterize quantitatively the electrochemical uptake/release process of Y3+ ions in various electroactive ions imprinted polymer films (E-IIPs), including non-ion, divalent nickel ion and trivalent yttrium ion imprinted FCN/PPy composite films. It is found that the reversible uptake/release of Y3+ ions can be realized by simply regulating the operating potential applied to the Y3+ ions imprinted composite film electrode in aqueous solution of 0.1 mol L−1 Y(NO3)3 due to the unique Y3+ ion identification capability of ion imprinted cavity and the dual driving forces resulting from both PPy and FCN. From the electrode mass change of different E-IIPs, one can speculate that parts of bound water molecules around the hydrated Y3+ ions could move into the E-IIPs with the ions adsorption process. Two distinct stages, the adsorption of Y3+ ions at the surface layer of E-IIPs and the transport of adsorbed ions to inner layer of E-IIPs, should be involved in the adsorption process of Y3+ ions into the E-IIPs. For hydrated Y3+ ions adsorbed electrochemically into the surface layer of Ni2+-imprinted and Y3+-imprinted

  19. Current-induced dynamics in carbon atomic contacts

    Directory of Open Access Journals (Sweden)

    Jing-Tao Lü

    2011-12-01

    Full Text Available Background: The effect of electric current on the motion of atoms still poses many questions, and several mechanisms are at play. Recently there has been focus on the importance of the current-induced nonconservative forces (NC and Berry-phase derived forces (BP with respect to the stability of molecular-scale contacts. Systems based on molecules bridging electrically gated graphene electrodes may offer an interesting test-bed for these effects.Results: We employ a semi-classical Langevin approach in combination with DFT calculations to study the current-induced vibrational dynamics of an atomic carbon chain connecting electrically gated graphene electrodes. This illustrates how the device stability can be predicted solely from the modes obtained from the Langevin equation, including the current-induced forces. We point out that the gate offers control of the current, independent of the bias voltage, which can be used to explore current-induced vibrational instabilities due the NC/BP forces. Furthermore, using tight-binding and the Brenner potential we illustrate how Langevin-type molecular-dynamics calculations including the Joule heating effect for the carbon-chain systems can be performed. Molecular dynamics including current-induced forces enables an energy redistribution mechanism among the modes, mediated by anharmonic interactions, which is found to be vital in the description of the electrical heating.Conclusion: We have developed a semiclassical Langevin equation approach that can be used to explore current-induced dynamics and instabilities. We find instabilities at experimentally relevant bias and gate voltages for the carbon-chain system.

  20. Dosimetric characterization of a microDiamond detector in clinical scanned carbon ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, Marco; Prestopino, G., E-mail: giuseppe.prestopino@uniroma2.it; Verona, C.; Verona-Rinati, G. [INFN—Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata,” Via del Politecnico 1, Roma 00133 (Italy); Ciocca, M.; Mirandola, A.; Mairani, A. [Fondazione CNAO, Strada Campeggi 53, Pavia 27100 (Italy); Raffaele, L. [INFN—Laboratori Nazionali del Sud, Via S. Sofia 62, Catania 95123, Italy and Fondazione CNAO, Strada Campeggi 53, Pavia 27100 (Italy); Magro, G. [INFN—Dipartimento di Fisica, Università degli Studi di Pavia, Via U. Bassi 6, Pavia 27100, Italy and Fondazione CNAO, Strada Campeggi 53, Pavia 27100 (Italy)

    2015-04-15

    Purpose: To investigate for the first time the dosimetric properties of a new commercial synthetic diamond detector (PTW microDiamond) in high-energy scanned clinical carbon ion beams generated by a synchrotron at the CNAO facility. Methods: The detector response was evaluated in a water phantom with actively scanned carbon ion beams ranging from 115 to 380 MeV/u (30–250 mm Bragg peak depth in water). Homogeneous square fields of 3 × 3 and 6 × 6 cm{sup 2} were used. Short- and medium-term (2 months) detector response stability, dependence on beam energy as well as ion type (carbon ions and protons), linearity with dose, and directional and dose-rate dependence were investigated. The depth dose curve of a 280 MeV/u carbon ion beam, scanned over a 3 × 3 cm{sup 2} area, was measured with the microDiamond detector and compared to that measured using a PTW Advanced Markus ionization chamber, and also simulated using FLUKA Monte Carlo code. The detector response in two spread-out-Bragg-peaks (SOBPs), respectively, centered at 9 and 21 cm depths in water and calculated using the treatment planning system (TPS) used at CNAO, was measured. Results: A negligible drift of detector sensitivity within the experimental session was seen, indicating that no detector preirradiation was needed. Short-term response reproducibility around 1% (1 standard deviation) was found. Only 2% maximum variation of microDiamond sensitivity was observed among all the evaluated proton and carbon ion beam energies. The detector response showed a good linear behavior. Detector sensitivity was found to be dose-rate independent, with a variation below 1.3% in the evaluated dose-rate range. A very good agreement between measured and simulated Bragg curves with both microDiamond and Advanced Markus chamber was found, showing a negligible LET dependence of the tested detector. A depth dose curve was also measured by positioning the microDiamond with its main axis oriented orthogonally to the beam