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Sample records for beam induced effects

  1. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    Science.gov (United States)

    Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  2. Scrape-off layer-induced beam density fluctuations and their effect on beam emission spectroscopy

    Science.gov (United States)

    Moulton, D.; Marandet, Y.; Tamain, P.; Dif-Pradalier, G.

    2015-07-01

    A statistical model is presented to calculate the magnitude of beam density fluctuations generated by a turbulent scrape-off layer (SOL). It is shown that the SOL can induce neutral beam density fluctuations of a similar magnitude to the plasma density fluctuations in the core, potentially corrupting beam emission spectroscopy measurements. The degree of corruption is quantified by combining simulations of beam and plasma density fluctuations inside a simulated measurement window. A change in pitch angle from the separatrix to the measurement window is found to reduce the effect of beam fluctuations, whose largest effect is to significantly reduce the measured correlation time.

  3. Memory effect on ion beam-induced depolymerization of PMMA

    Energy Technology Data Exchange (ETDEWEB)

    Compagnini, G.; Angilella, G.G.N. E-mail: giuseppe.angilella@ct.infn.it; Raudino, A.; Puglisi, O. E-mail: opuglisi@dipchi.unict.it

    2001-04-01

    Recently a new ion beam-induced phenomenology - depolymerization of macromolecular target - has been found and studied in our laboratory. This has been observed in poly(methylmethacrylate) (PMMA) using He{sup +} 300 keV ion beam, in a temperature range much lower than that required for thermal depolymerization. Here we report an in situ monitoring of PMMA depolymerization performed by mass spectrometry. We have found that at a given temperature the monomer flux due to depolymerization of the bombarded polymer is much more intense when the temperature is quenched, with respect to the same temperature during heating. The results have been rationalized by using an accurate model that involves initiation and propagation kinetics followed by the diffusion process. The use of the model allowed us to exclude any influence of transport properties of PMMA on this effect but indicates that the hysteresis phenomenon detected at macroscopic level has a microscopic counterpart linked to the chemical yields of the depolymerization kinetics.

  4. Ion beam induced effects on the ferromagnetism in Pd nanoparticles

    International Nuclear Information System (INIS)

    Kulriya, P. K.; Mehta, B. R.; Agarwal, D. C.; Agarwal, Kanika; Kumar, Praveen; Shivaprasad, S. M.; Avasthi, D. K.

    2012-01-01

    Present study demonstrates the role of metal-insulator interface and ion irradiation induced defects on the ferromagnetic properties of the non-magnetic materials. Magnetic properties of the Pd nanoparticles(NPs) embedded in the a-silica matrix synthesized using atom beam sputtering technique, were determined using SQUID magnetometry measurements which showed that ferromagnetic response of Pd increased by 3.5 times on swift heavy ion(SHI) irradiation. The ferromagnetic behavior of the as-deposited Pd NPs is due to strain induced by the surrounding matrix and modification in the electronic structure at the Pd-silica interface as revealed by insitu XRD and XPS investigations, respectively. The defects created by the SHI bombardment are responsible for enhancement of the magnetization in the Pd NPs.

  5. Laser Induced Breakdown Spectroscopy Based on Single Beam Splitting and Geometric Configuration for Effective Signal Enhancement

    OpenAIRE

    Yang, Guang; Lin, Qingyu; Ding, Yu; Tian, Di; Duan, Yixiang

    2015-01-01

    A new laser induced breakdown spectroscopy (LIBS) based on single-beam-splitting (SBS) and proper optical geometric configuration has been initially explored in this work for effective signal enhancement. In order to improve the interaction efficiency of laser energy with the ablated material, a laser beam operated in pulse mode was divided into two streams to ablate/excite the target sample in different directions instead of the conventional one beam excitation in single pulse LIBS (SP-LIBS)...

  6. Beam induced RF heating

    CERN Document Server

    Salvant, B; Arduini, G; Assmann, R; Baglin, V; Barnes, M J; Bartmann, W; Baudrenghien, P; Berrig, O; Bracco, C; Bravin, E; Bregliozzi, G; Bruce, R; Bertarelli, A; Carra, F; Cattenoz, G; Caspers, F; Claudet, S; Day, H; Garlasche, M; Gentini, L; Goddard, B; Grudiev, A; Henrist, B; Jones, R; Kononenko, O; Lanza, G; Lari, L; Mastoridis, T; Mertens, V; Métral, E; Mounet, N; Muller, J E; Nosych, A A; Nougaret, J L; Persichelli, S; Piguiet, A M; Redaelli, S; Roncarolo, F; Rumolo, G; Salvachua, B; Sapinski, M; Schmidt, R; Shaposhnikova, E; Tavian, L; Timmins, M; Uythoven, J; Vidal, A; Wenninger, J; Wollmann, D; Zerlauth, M

    2012-01-01

    After the 2011 run, actions were put in place during the 2011/2012 winter stop to limit beam induced radio frequency (RF) heating of LHC components. However, some components could not be changed during this short stop and continued to represent a limitation throughout 2012. In addition, the stored beam intensity increased in 2012 and the temperature of certain components became critical. In this contribution, the beam induced heating limitations for 2012 and the expected beam induced heating limitations for the restart after the Long Shutdown 1 (LS1) will be compiled. The expected consequences of running with 25 ns or 50 ns bunch spacing will be detailed, as well as the consequences of running with shorter bunch length. Finally, actions on hardware or beam parameters to monitor and mitigate the impact of beam induced heating to LHC operation after LS1 will be discussed.

  7. Cooperative effect of ultraviolet and near-infrared beams in laser-induced condensation

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, M.; Henin, S.; Pomel, F.; Kasparian, J.; Wolf, J.-P. [Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, 1211 Geneva 4 (Switzerland); Théberge, F.; Daigle, J.-F. [Defence R and D Canada Valcartier, 2459 de la Bravoure Blvd., Quebec (Qc) G3J 1X5 (Canada); Lassonde, P.; Kieffer, J.-C. [INRS-EMT, 1650 Lionel Boulet Blvd., Varennes, Quebec (Qc) J3X1S2 (Canada)

    2013-12-23

    We demonstrate the cooperative effect of near infrared (NIR) and ultraviolet (UV) beams on laser-induced condensation. Launching a UV laser after a NIR pulse yields up to a 5-fold increase in the production of nanoparticles (25–300 nm) as compared to a single NIR beam. This cooperative effect exceeds the sum of those from the individual beams and occurs for delays up to 1 μs. We attribute it to the UV photolysis of ozone created by the NIR pulses. The resulting OH radicals oxidize NO{sub 2} and volatile organic compounds, producing condensable species.

  8. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  9. Beam-Induced Multipactoring and Electron-Cloud Effects in Particle Accelerators

    CERN Document Server

    Caspers, Friedhelm; Scandale, Walter; Zimmermann, F

    2009-01-01

    In the beam pipe of high-energy proton or positron accelerators an “electron cloud” can be generated by a variety of processes, e.g. by residual-gas ionization, by photoemission from synchrotron radiation, and, most importantly, by secondary emission via a beam-induced multipactoring process. The electron cloud commonly leads to a degradation of the beam vacuum by several orders of magnitude, to fast beam instabilities, to beam-size increases, and to fast or slow beam losses. At the Large Hadron Collider (LHC), the cloud electrons could also give rise to an additional heat load inside cold superconducting magnets. In addition to the direct heat deposition from incoherently moving electrons, a potential “magnetron effect” has been conjectured, where electrons would radiate coherently when moving in a strong magnetic field under the simultaneous influence of a beam-induced electric “wake” field that may become resonant with the cyclotron frequency. Electron-cloud effects are already being observed w...

  10. Effects induced by LHC high energy beam in copper structures

    CERN Document Server

    Peroni, L; Dallocchio, A

    2011-01-01

    This study is performed in order to estimate the damage on copper components due to the impact of a 7 TeV proton beam in the Large Hadron Collider. The case study represents an accidental case consequent to an abnormal release of the beam, in which eight bunches impact directly the copper. The energy delivered on the components is calculated by the FLUKA Team at CERN using their Monte-Carlo code for calculation of particle transport and interactions with matter. The energy maps are used by the authors as input for the structural simulations carried out via the FEM code LS-DYNA. The evolution of the phenomenon is quite similar to what might happen during an explosion. The impacted part of the component reaches extremely high values of pressure and temperature and undergoes changes of state. The sudden increase in pressure originates outgoing shockwaves that, travelling through the component, lead to a substantial density reduction in the impacted part. The energy delivered on the component is sufficient to sev...

  11. Laser induced breakdown spectroscopy based on single beam splitting and geometric configuration for effective signal enhancement.

    Science.gov (United States)

    Yang, Guang; Lin, Qingyu; Ding, Yu; Tian, Di; Duan, Yixiang

    2015-01-05

    A new laser induced breakdown spectroscopy (LIBS) based on single-beam-splitting (SBS) and proper optical geometric configuration has been initially explored in this work for effective signal enhancement. In order to improve the interaction efficiency of laser energy with the ablated material, a laser beam operated in pulse mode was divided into two streams to ablate/excite the target sample in different directions instead of the conventional one beam excitation in single pulse LIBS (SP-LIBS). In spatial configuration, the laser beam geometry plays an important role in the emission signal enhancement. Thus, an adjustable geometric configuration with variable incident angle between the two splitted laser beams was constructed for achieving maximum signal enhancement. With the optimized angles of 60° and 70° for Al and Cu atomic emission lines at 396.15 nm and 324.75 nm respectively, about 5.6- and 4.8-folds signal enhancements were achieved for aluminum alloy and copper alloy samples compared to SP-LIBS. Furthermore, the temporal analysis, in which the intensity of atomic lines in SP-LIBS decayed at least ten times faster than the SBS-LIBS, proved that the energy coupling efficiency of SBS-LIBS was significantly higher than that of SP-LIBS.

  12. Laser Induced Breakdown Spectroscopy Based on Single Beam Splitting and Geometric Configuration for Effective Signal Enhancement

    Science.gov (United States)

    Yang, Guang; Lin, Qingyu; Ding, Yu; Tian, Di; Duan, Yixiang

    2015-01-01

    A new laser induced breakdown spectroscopy (LIBS) based on single-beam-splitting (SBS) and proper optical geometric configuration has been initially explored in this work for effective signal enhancement. In order to improve the interaction efficiency of laser energy with the ablated material, a laser beam operated in pulse mode was divided into two streams to ablate/excite the target sample in different directions instead of the conventional one beam excitation in single pulse LIBS (SP-LIBS). In spatial configuration, the laser beam geometry plays an important role in the emission signal enhancement. Thus, an adjustable geometric configuration with variable incident angle between the two splitted laser beams was constructed for achieving maximum signal enhancement. With the optimized angles of 60° and 70° for Al and Cu atomic emission lines at 396.15 nm and 324.75 nm respectively, about 5.6- and 4.8-folds signal enhancements were achieved for aluminum alloy and copper alloy samples compared to SP-LIBS. Furthermore, the temporal analysis, in which the intensity of atomic lines in SP-LIBS decayed at least ten times faster than the SBS-LIBS, proved that the energy coupling efficiency of SBS-LIBS was significantly higher than that of SP-LIBS. PMID:25557721

  13. Effect of storage conditions on graft of polypropylene non-woven fabric induced by electron beam

    International Nuclear Information System (INIS)

    Lee, Jin Young; Jeun, Joon Pyo; Kang, Phil Hyun

    2015-01-01

    In this study, we fabricated effect of storage conditions on graft of polypropylene (PP) non-woven fabric induced by electron beam. The electron beam irradiations on PP non-woven fabric were carried out over a range of irradiation doses from 25 to 100 kGy to make free radicals on fabric surface. The radical measurement was established by electron spin resonance (ESR) for confirming the changes of the alkyl radical and peroxy radical according to effect of storage time, storage temperature and atmosphere. It was observed that the free radicals were increased with irradiation dose and decreased with storage time due to the continuous oxidation. However, the radical extinction was significantly delayed due to reduced mobility of radicals at extremely low temperature. The degree of graft based on the analysis of ESR was investigated. The conditions of graft reaction were set at a temperature: 60 degrees Celcius, reaction time: 6 hours and styrene monomer concentration: 20 wt%

  14. Effect of storage conditions on graft of polypropylene non-woven fabric induced by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Young; Jeun, Joon Pyo; Kang, Phil Hyun [Radiation Research Dvision for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

    2015-05-15

    In this study, we fabricated effect of storage conditions on graft of polypropylene (PP) non-woven fabric induced by electron beam. The electron beam irradiations on PP non-woven fabric were carried out over a range of irradiation doses from 25 to 100 kGy to make free radicals on fabric surface. The radical measurement was established by electron spin resonance (ESR) for confirming the changes of the alkyl radical and peroxy radical according to effect of storage time, storage temperature and atmosphere. It was observed that the free radicals were increased with irradiation dose and decreased with storage time due to the continuous oxidation. However, the radical extinction was significantly delayed due to reduced mobility of radicals at extremely low temperature. The degree of graft based on the analysis of ESR was investigated. The conditions of graft reaction were set at a temperature: 60 degrees Celcius, reaction time: 6 hours and styrene monomer concentration: 20 wt%.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kupka, Katharina

    2016-08-15

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

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

    International Nuclear Information System (INIS)

    Kupka, Katharina

    2016-08-01

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

  17. Study of the thermal effect on silicon surface induced by ion beam from plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Z., E-mail: pscientific5@aec.org.sy [Scientific Service Department, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic); Ahmad, M. [IBA Laboratory, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic); Chemistry Department, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic); Al-Hawat, Sh.; Akel, M. [Physics Department, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic)

    2017-04-01

    Structural modifications in form of ripples and cracks are induced by nitrogen ions from plasma focus on silicon surface. The investigation of such structures reveals correlation between ripples and cracks formation in peripheral region of the melt spot. The reason of such correlation and structure formation is explained as result of thermal effect. Melting and resolidification of the center of irradiated area occur within one micro second of time. This is supported by a numerical simulation used to investigate the thermal effect induced by the plasma focus ion beams on the silicon surface. This simulation provides information about the temperature profile as well as the dynamic of the thermal propagation in depth and lateral directions. In accordance with the experimental observations, that ripples are formed in latter stage after the arrival of last ion, the simulation shows that the thermal relaxation takes place in few microseconds after the end of the ion beam arrival. Additionally, the dependency of thermal propagation and relaxation on the distance of the silicon surface from the anode is presented.

  18. Effects on cuytoskeleton system in pollen tube of pinus thunbergii induced by ion beam implantation

    International Nuclear Information System (INIS)

    Huang Qunce; Liang Qiuxia; Li Guopin

    2008-01-01

    The damage of the cytoskeleton system in the pollen and the pollen tube of Pinus thunbergii induced by ion beam implantation were researched. The results showed that the disorganization of the micro-tubules in the pollen tube was produced by N + implantation. The abnormal states of the pollen tube in morphology were very correlative with the abnormality of the cytoskeleton system. N + implantation was responsible for morphological abnormalities in the pollen tubes. There was a distinct correlation between the damage effects and the ion implantation dose. The add of dose caused more obvious damage effects. Furthermore, the state of the cytoskeleton system in the pollen tube was influenced by the ion implantation. The impact grade depended also on the ion implantation dose. (authors)

  19. Polarization-dependent single-beam laser-induced grating-like effects on titanium films

    International Nuclear Information System (INIS)

    Camacho-Lopez, Santiago; Evans, Rodger; Escobar-Alarcon, Luis; Camacho-Lopez, Miguel A.; Camacho-Lopez, Marco A.

    2008-01-01

    In this paper we present results on polarization-dependent laser-induced effects on titanium (Ti) thin films. We irradiated the titanium films, in ambient air, using a nanosecond Nd:YAG laser (532 nm, 9 ns pulse duration, 10 Hz). Using a series of pulses of fluence well below the ablation threshold, it was possible to form grating-like structures, whose grooves run parallel to the linear polarization of the incident beam. No grating-like structures were obtained when circularly polarized light was used. Our results revealed the remarkable formation of tiny (100 nm and even smaller diameter) craters, which self-arrange quasi-periodically along the ridges (never on the valleys) of the grating-like structure. Optical and scanning electron microscopy were used to study the laser-induced changes on the surface of the titanium films. Micro-Raman spectroscopy was used to analyze the irradiated areas on the titanium films. The Raman analysis demonstrated that the grooves in the grating-like structure, build up from the laser-induced oxidation of titanium. This is the first time, to the best of our knowledge, that periodic surface structures are reported to be induced below the ablation threshold regime, with the grooves made of crystalline metal oxide, in this case TiO 2 in the well-known Rutile phase. The laser irradiated areas on the film acquired selective (upon recording polarization) holographic reflectance

  20. Polarization-dependent single-beam laser-induced grating-like effects on titanium films

    Energy Technology Data Exchange (ETDEWEB)

    Camacho-Lopez, Santiago [Departamento de Optica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California 22860 (Mexico)], E-mail: camachol@cicese.mx; Evans, Rodger [Departamento de Optica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California 22860 (Mexico); Escobar-Alarcon, Luis [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Mexico DF 11801 (Mexico); Camacho-Lopez, Miguel A. [Facultad de Medicina, Universidad Autonoma del Estado de Mexico, Paseo Tollocan s/n, esq. Jesus Carranza, Toluca, Estado de Mexico 50120 (Mexico); Camacho-Lopez, Marco A. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Tollocan s/n, esq. Paseo Colon, Toluca, Estado de Mexico, 50110 (Mexico)

    2008-12-30

    In this paper we present results on polarization-dependent laser-induced effects on titanium (Ti) thin films. We irradiated the titanium films, in ambient air, using a nanosecond Nd:YAG laser (532 nm, 9 ns pulse duration, 10 Hz). Using a series of pulses of fluence well below the ablation threshold, it was possible to form grating-like structures, whose grooves run parallel to the linear polarization of the incident beam. No grating-like structures were obtained when circularly polarized light was used. Our results revealed the remarkable formation of tiny (100 nm and even smaller diameter) craters, which self-arrange quasi-periodically along the ridges (never on the valleys) of the grating-like structure. Optical and scanning electron microscopy were used to study the laser-induced changes on the surface of the titanium films. Micro-Raman spectroscopy was used to analyze the irradiated areas on the titanium films. The Raman analysis demonstrated that the grooves in the grating-like structure, build up from the laser-induced oxidation of titanium. This is the first time, to the best of our knowledge, that periodic surface structures are reported to be induced below the ablation threshold regime, with the grooves made of crystalline metal oxide, in this case TiO{sub 2} in the well-known Rutile phase. The laser irradiated areas on the film acquired selective (upon recording polarization) holographic reflectance.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  2. Charging effects during focused electron beam induced deposition of silicon oxide

    NARCIS (Netherlands)

    de Boer, Sanne K.; van Dorp, Willem F.; De Hosson, Jeff Th. M.

    2011-01-01

    This paper concentrates on focused electron beam induced deposition of silicon oxide. Silicon oxide pillars are written using 2, 4, 6, 8, 10-pentamethyl-cyclopenta-siloxane (PMCPS) as precursor. It is observed that branching of the pillar occurs above a minimum pillar height. The branching is

  3. Ultrahigh resolution focused electron beam induced processing: the effect of substrate thickness

    DEFF Research Database (Denmark)

    van Dorp, Willem F; Lazic, Ivan; Beyer, André

    2011-01-01

    It is often suggested that the growth in focused electron beam induced processing (FEBIP) is caused not only by primary electrons, but also (and even predominantly) by secondary electrons (SEs). If that is true, the growth rate for FEBIP can be changed by modifying the SE yield. Results from our ...

  4. Ion-beam-induced migration and its effect on concentration profiles

    International Nuclear Information System (INIS)

    Myers, S.M.

    1979-01-01

    The mechanisms by which ion irradiation influences atomic transport are reviewed, including cascade mixing, enhanced diffusion via mobile point defects, rapid diffusion along extended defects, and solute trapping at irradiation damage. The effects of these processes on measured concentration profiles are considered for high-energy ion beam analysis

  5. Study of Thermo-Mechanical Effects Induced in Solids by High Energy Particle Beams: Analytical and Numerical Methods

    CERN Document Server

    Dallocchio, Alessandro; Kurtyka, T; Bertarelli, A

    2008-01-01

    Requirements of modern nuclear physics entail big efforts in the field of particle accelerator technology in order to build powerful machines providing particle beams at higher and higher energies; in this context, the Large Hadron Collider represents the future for particle physics. The LHC stores 360 MJ for each circulating beam; this large amount of energy is potentially destructive for accelerator equipments having direct interaction with particles; the need to handle high thermal loads bestows strategic importance to the study of thermo-mechanical problems in accelerator devices. The aim of this work is the study of thermo-mechanical effects induced in solids by high energy particle beams. Development of facilities devoted to the experimental test of accelerator equipments in real working conditions presents several technical difficulties and high cost; the importance of developing reliable methods and accurate models that could be efficiently applied during the design phase of the most critical particle...

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

    International Nuclear Information System (INIS)

    Kupka, K.; Tomut, M.; Simon, P.; Hubert, C.; Romanenko, A.; Lommel, B.; Trautmann, C.

    2015-01-01

    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)

  7. Beam Induced Pressure Rise at RHIC

    CERN Document Server

    Zhang, S Y; Bai, Mei; Blaskiewicz, Michael; Cameron, Peter; Drees, Angelika; Fischer, Wolfram; Gullotta, Justin; He, Ping; Hseuh Hsiao Chaun; Huang, Haixin; Iriso, Ubaldo; Lee, Roger C; Litvinenko, Vladimir N; MacKay, William W; Nicoletti, Tony; Oerter, Brian; Peggs, Steve; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smart, Loralie; Snydstrup, Louis; Thieberger, Peter; Trbojevic, Dejan; Wang, Lanfa; Wei, Jie; Zeno, Keith

    2005-01-01

    Beam induced pressure rise in RHIC warm sections is currently one of the machine intensity and luminosity limits. This pressure rise is mainly due to electron cloud effects. The RHIC warm section electron cloud is associated with longer bunch spacings compared with other machines, and is distributed non-uniformly around the ring. In addition to the countermeasures for normal electron cloud, such as the NEG coated pipe, solenoids, beam scrubbing, bunch gaps, and larger bunch spacing, other studies and beam tests toward the understanding and counteracting RHIC warm electron cloud are of interest. These include the ion desorption studies and the test of anti-grazing ridges. For high bunch intensities and the shortest bunch spacings, pressure rises at certain locations in the cryogenic region have been observed during the past two runs. Beam studies are planned for the current 2005 run and the results will be reported.

  8. Characterization of ion beam induced nanostructures

    International Nuclear Information System (INIS)

    Ghatak, J.; Satpati, B.; Umananda, M.; Kabiraj, D.; Som, T.; Dev, B.N.; Akimoto, K.; Ito, K.; Emoto, T.; Satyam, P.V.

    2006-01-01

    Tailoring of nanostructures with energetic ion beams has become an active area of research leading to the fundamental understanding of ion-solid interactions at nanoscale regime and with possible applications in the near future. Rutherford backscattering spectrometry (RBS), high resolution transmission electron microscopy (HRTEM) and asymmetric X-ray Bragg-rocking curve experimental methods have been used to characterize ion-induced effects in nanostructures. The possibility of surface and sub-surface/interface alloying at nano-scale regime, ion-beam induced embedding, crater formation, sputtering yield variations for systems with isolated nanoislands, semi-continuous and continuous films of noble metals (Au, Ag) deposited on single crystalline silicon will be reviewed. MeV-ion induced changes in specified Au-nanoislands on silicon substrate are tracked as a function of ion fluence using ex situ TEM. Strain induced in the bulk silicon substrate surface due to 1.5 MeV Au 2+ and C 2+ ion beam irradiation is determined by using HRTEM and asymmetric Bragg X-ray rocking curve methods. Preliminary results on 1.5 MeV Au 2+ ion-induced effects in nanoislands of Co deposited on silicon substrate will be discussed

  9. Characterization of ion beam induced nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Ghatak, J. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Satpati, B. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Umananda, M. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Kabiraj, D. [Nuclear Science Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Som, T. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Dev, B.N. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Akimoto, K. [Department of Quantum Engineering, Nagoya University, Nagoya 464-8603 (Japan); Ito, K. [Department of Quantum Engineering, Nagoya University, Nagoya 464-8603 (Japan); Emoto, T. [Toyota National College of Technology, 2-1, Toyota, Aichi 471-8525 (Japan); Satyam, P.V. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India)]. E-mail: satyam@iopb.res.in

    2006-03-15

    Tailoring of nanostructures with energetic ion beams has become an active area of research leading to the fundamental understanding of ion-solid interactions at nanoscale regime and with possible applications in the near future. Rutherford backscattering spectrometry (RBS), high resolution transmission electron microscopy (HRTEM) and asymmetric X-ray Bragg-rocking curve experimental methods have been used to characterize ion-induced effects in nanostructures. The possibility of surface and sub-surface/interface alloying at nano-scale regime, ion-beam induced embedding, crater formation, sputtering yield variations for systems with isolated nanoislands, semi-continuous and continuous films of noble metals (Au, Ag) deposited on single crystalline silicon will be reviewed. MeV-ion induced changes in specified Au-nanoislands on silicon substrate are tracked as a function of ion fluence using ex situ TEM. Strain induced in the bulk silicon substrate surface due to 1.5 MeV Au{sup 2+} and C{sup 2+} ion beam irradiation is determined by using HRTEM and asymmetric Bragg X-ray rocking curve methods. Preliminary results on 1.5 MeV Au{sup 2+} ion-induced effects in nanoislands of Co deposited on silicon substrate will be discussed.

  10. Effect of an ultrafast laser induced plasma on a relativistic electron beam to determine temporal overlap in pump–probe experiments

    Energy Technology Data Exchange (ETDEWEB)

    Scoby, Cheyne M., E-mail: scoby@physics.ucla.edu [UCLA Department of Physics, 475 Portola Plaza, Los Angeles, CA 90095-1547 (United States); Li, R.K.; Musumeci, P. [UCLA Department of Physics, 475 Portola Plaza, Los Angeles, CA 90095-1547 (United States)

    2013-04-15

    In this paper we report on a simple and robust method to measure the absolute temporal overlap of the laser and the electron beam at the sample based on the effect of a laser induced plasma on the electron beam transverse distribution, successfully extending a similar method from keV to MeV electron beams. By pumping a standard copper TEM grid to form the plasma, we gain timing information independent of the sample under study. In experiments discussed here the optical delay to achieve temporal overlap between the pump electron beam and probe laser can be determined with ∼1ps precision.

  11. Thermal effect induced wafer deformation in high-energy e-beam lithography

    Science.gov (United States)

    Chen, P. S.; Wang, W. C.; Lin, S. J.

    2015-03-01

    The incident surface power density in Massive Electron-beam Direct Write (MEBDW) during exposure is ~105 W/cm2, much higher than ~8 W/cm2 ArF scanners and 2.4 W/cm2 EUV. In addition, the wafer's exposure in vacuum environment makes energy dissipation even harder. This thermal effect can cause mechanical distortion of the wafer during exposure and have has a direct influence on pattern placement error and image blur. In this paper, the thermo mechanical distortions caused by wafer heating for MEB system of different electron acceleration voltages have been simulated with finite element method (FEM). The global thermal effect affected by the friction force between the wafer and the wafer chuck as well as different thermal conductivities of the chuck material are simulated. Furthermore, the thermal effects of different lithography systems such as EUV scanners and conventional optical scanners are compared. The thermal effects of MEBDW systems are shown to be acceptable.

  12. Study on the effect of beam propagation through atmospheric turbulence on standoff nanosecond laser induced breakdown spectroscopy measurements.

    Science.gov (United States)

    Laserna, J J; Reyes, R Fernández; González, R; Tobaria, L; Lucena, P

    2009-06-08

    We report on an experimental study of the effect of atmospheric turbulence on laser induced breakdown spectroscopy (LIBS) measurements. The characteristics of the atmosphere dictate specific performance constraints to this technology. Unlike classical laboratory LIBS systems where the distance to the sample is well known and characterized, LIBS systems working at several tens of meters to the target have specific atmospheric propagation conditions that cause the quality of the LIBS signals to be affected to a significant extent. Using a new LIBS based sensor system fitted with a nanosecond laser emitting at 1064 nm, propagation effects at distances of up to 120 m were investigated. The effects observed include wander and scintillation in the outgoing laser beam and in the return atomic emission signal. Plasmas were formed on aluminium targets. Average signal levels and signal fluctuations are measured so the effect of atmospheric turbulence on LIBS measurements is quantified.

  13. Protective effect of Asparagus racemosus root extract against lethal total - body electron beam radiation induced damage in Swiss albino mice

    International Nuclear Information System (INIS)

    Sharmila, K.P.; Bhandary, B. Satheesh Kumar; Suchetha Kumari, N.; Bhat, Vadish S.; Shetty, Jayaram; Peter, Alex John; Jose, Jerish M.; Fernandes, Ronald

    2016-01-01

    To investigate the protective effect of Asparagus Racemosus Root ethanolic extract (ARE) in Swiss albino mice against acute lethal total - body Electron beam irradiation. Swiss Albino mice were used for the assessment of radiation induced sickness and 30 day survival analysis. Survival studies were determined using the Kaplan-Meier survival curves. The maximum survival was observed in the experimental mice pretreated with 200 mg/kg.b.wt. of ARE which also reduced the radiation sickness characteristics. This dose was considered as an optimal dose for radioprotection. Treatment of mice with ARE before irradiation delayed the onset of mortality as compared with the untreated irradiated controls. Present findings demonstrate the potential of ARE in mitigating radiation-induced mortality, which may be attributed to its free radical scavenging and increased antioxidant potential

  14. OBSERVATION OF STRONG - STRONG AND OTHER BEAM - BEAM EFFECTS IN RHIC

    International Nuclear Information System (INIS)

    FISCHER, W.; BLASKIEWICZ, M.; BRENNAN, J.M.; CAMERON, P.; CONNOLLY, R.; MONTAG, C.; PEGGS, S.; PILAT, F.; PTITSYN, V.; TEPIKIAN, S.; TRBOJEVIC, D.; VAN ZEIJTS, J.

    2003-01-01

    RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. For the first time, coherent beam-beam modes were observed in a bunched beam hadron collider. Other beam-beam effects in RHIC were observed in operation and in dedicated experiments with gold ions, deuterons and protons. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. During ramps unequal radio frequencies in the two rings cause the crossing points to move longitudinally. Thus bunches experience beam-beam interactions only in intervals and the tunes are modulated. In this article we summarize the most important beam-beam observations made so far

  15. Shock loads induced on metal structures by LHC proton beams: modelling of thermo-mechanical effects

    CERN Document Server

    Peroni, L; Dallocchio, A; Bertarelli, A

    2011-01-01

    In this work, the numerical simulations of the LHC high energy particle beam impact against a metal structure are performed using the commercial FEM code LS-DYNA. The evaluation of thermal loads on the hit material is performed using a statistical code, called FLUKA, based on the Monte-Carlo method, which returns an energy map on a particular geometry (taking into account all the particles in the cascade generated by the interaction between the proton beam and the target). The FLUKA results are then used as input for thermo-structural studies. The first step of this work is the validation of the numerical procedure on a simple geometry for two different materials (copper and tungsten) and constitutive material models. In particular, the high energy particle impact is examined on a facially irradiated cylindrical bar: the beam hits the component directly on the centre of the basis. Then the final step is the study of the impact on a real structure with an energy beam of 5 TeV (the next target in the energy val...

  16. Destructive effects induced by the electron beam in scanning electron microscopy

    Science.gov (United States)

    Popescu, M. C.; Bita, B. I.; Banu, M. A.; Tomescu, R. M.

    2016-12-01

    The Scanning Electron Microscopy has been validated by its impressive imaging and reliable measuring as an essential characterization tool for a variety of applications and research fields. This paper is a comprehensive study dedicated to the undesirable influence of the accelerated electron beam associated with the dielectric materials, sensitive structures or inappropriate sample manipulation. Depending on the scanning conditions, the electron beam may deteriorate the investigated sample due to the extended focusing or excessive high voltage and probe current applied on vulnerable configurations. Our aim is to elaborate an instructive material for improved SEM visualization capabilities by overcoming the specific limitations of the technique. Particular examination and measuring methods are depicted along with essential preparation and manipulation procedures in order to protect the integrity of the sample. Various examples are mentioned and practical solutions are described in respect to the general use of the electron microscope.

  17. Electron beam-induced mass transport in As–Se thin films: compositional dependence and glass network topological effects

    International Nuclear Information System (INIS)

    Trunov, M L; Cserháti, C; Lytvyn, P M; Kaganovskii, Yu; Kökényesi, S

    2013-01-01

    Electron beam (e-beam)-induced changes of surface profile morphology in As c Se 1−c (0.2 0.2 Se 0.8 are connected with lateral mass transport, which increases drastically near rigidity transition, i.e. at a coordination number r ∼ 2.2 of the glass structures when the rigidity starts to percolate through the structure. The model of the process, which reflects the compositional dependence of the stimulated mass transport, is presented. (paper)

  18. THE EFFECTS OF ELECTRON-BEAM-INDUCED ELECTRIC FIELD ON THE GENERATION OF LANGMUIR TURBULENCE IN FLARING ATMOSPHERES

    International Nuclear Information System (INIS)

    Zharkova, Valentina V.; Siversky, Taras V.

    2011-01-01

    The precipitation of an electron beam injected into the solar atmosphere is studied for the generation of Langmuir wave turbulence in the presence of collisional and Ohmic losses. The system of quasi-linear time-dependent kinetic equations describing the evolution of beams and Langmuir waves is solved by using the summary approximation method. It is found that at upper atmospheric levels the self-induced electric field suppresses the generation of Langmuir turbulence to very small regions below injection. With further precipitation into deeper atmosphere the initial single power-law distributions of beam electrons are transformed into energy distributions with maxima at lower energies formed by collisional and Ohmic energy depletion. The electrons with lower energies (<20 keV) generate on large spatial scales intense low-hybrid and high-hybrid Langmuir waves with well-defined patterns in the corona while higher energy electrons generate moderate low-hybrid waves in the chromosphere. The maximum wave density appears at the maximum of the ambient density. The self-induced electric field reduces the level and makes the regions with low-hybrid Langmuir turbulence narrower in the corona and upper chromosphere. The higher the beam energy flux or its self-induced electric field, the narrower the regions with Langmuir turbulence. High-hybrid Langmuir waves in the form of multiple patterns in space (in the corona) and energy (below 20 keV) are found to be generated only by a very intense electron beam. The number of patterns in both dimensions is also shown to be significantly reduced by the self-induced electric field.

  19. Effect of chemical structure on electron beam-induced decomposition of onium salts

    International Nuclear Information System (INIS)

    Hult, A.; Sundell, P.E.

    1990-01-01

    This work has been focused on the reduction of iodonium and sulfonium salts by organic free radicals or solvated electrons resulting in a Broensted (protonic) acid or a carbenium ion capable of initiating the cationic polymerization of vinyl ethers. An increased knowledge of the interplay between modes of activation, onium salt structure and the vinyl ether structure have been obtained. Gamma ray induced reduction of the onium salts by free radicals or solvated electrons revealed the importance of the onium salt structure for the redox reaction. Since the most important feature of high energy-induced cationic polymerization is the reduction of onium salt, the reactivity of a formulation (efficiency of the redox process) can be altered by: the onium salt (reduction potential), the monomer structure (radiation chemistry, yields of radicals and solvated electrons) and by the dose rate (yields of radicals and solvated electrons)

  20. Aerosol nucleation induced by a high energy particle beam

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Pedersen, Jens Olaf Pepke; Uggerhøj, Ulrik I.

    2011-01-01

    -effect on aerosol nucleation using a particle beam under conditions that resemble the Earth's atmosphere. By comparison with ionization using a gamma source we further show that the nature of the ionizing particles is not important for the ion-induced component of the nucleation. This implies that inexpensive...... ionization sources - as opposed to expensive accelerator beams - can be used for investigations of ion-induced nucleation....

  1. Focused electron beam induced processing and the effect of substrate thickness revisited

    DEFF Research Database (Denmark)

    van Dorp, W. F.; Beyer, A.; Mainka, M.

    2013-01-01

    at a precursor pressure 20 times lower than previously. Then, despite using membranes thinner than the SE escape depth, we did not see an effect on the experimental growth rate. We explain our current results by the fact that very early in the process, the growth becomes dominated by the growing deposit itself....

  2. 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.

  3. Geometric continuum mechanics and induced beam theories

    CERN Document Server

    R Eugster, Simon

    2015-01-01

    This research monograph discusses novel approaches to geometric continuum mechanics and introduces beams as constraint continuous bodies. In the coordinate free and metric independent geometric formulation of continuum mechanics as well as for beam theories, the principle of virtual work serves as the fundamental principle of mechanics. Based on the perception of analytical mechanics that forces of a mechanical system are defined as dual quantities to the kinematical description, the virtual work approach is a systematic way to treat arbitrary mechanical systems. Whereas this methodology is very convenient to formulate induced beam theories, it is essential in geometric continuum mechanics when the assumptions on the physical space are relaxed and the space is modeled as a smooth manifold. The book addresses researcher and graduate students in engineering and mathematics interested in recent developments of a geometric formulation of continuum mechanics and a hierarchical development of induced beam theories.

  4. Time resolved ion beam induced charge collection

    International Nuclear Information System (INIS)

    Sexton W, Frederick; Walsh S, David; Doyle L, Barney; Dodd E, Paul

    2000-01-01

    Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved Ion Beam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a -.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ion beam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients

  5. Beam-beam effects in the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; Alexahin, Y.; Lebedev, V.; Lebrun, P.; Moore, R.S.; Sen, T.; Tollestrup, A.; Valishev, A.; Zhang, X.L.; /Fermilab

    2005-01-01

    The Tevatron in Collider Run II (2001-present) is operating with 6 times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams have been significant sources of beam loss and lifetime limitations. We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in operations, predict the performance for planned luminosity upgrades, and discuss ways to improve it.

  6. Mechanical polishing to improve uniformity of beam sampling grating and its effects on laser-induced damage

    Science.gov (United States)

    Rao, Huanle; Liu, Zhengkun; Liu, Ying; Fu, Shaojun

    2012-01-01

    As an important optical element, beam sampling grating (BSG) is used in the terminal of inertial confinement fusion (ICF) drivers. It can provide a very slight sampling beam for the precision diagnosing of laser energy and wavefront distortion. However, in practice, its non-uniform diffraction efficiency seriously influences the accurate signal of sampling beam, and finally affects diagnostic ability. BSG is usually fabricated by holographic ion beam etched (HIBE) process. In this paper, a mechanical polishing processing technology was used to improve uniformity of the diffraction efficiency of BSG after HIBE. In the processing, cerium oxide (CeO2) was used to polish the local areas of grating where exhibit higher diffraction efficiency with the purpose of changing the depth of grating profile, and then they have similar efficiency with the surrounding areas. By iteration of the above process, BSG finally achieve the improved uniformity of diffraction efficiency over the area of a 430 x 430 mm2. The RMS of diffraction efficiency of BSG after mechanical polishing shows great reduction down to 4.8% as compared with that of the as-polished RMS of 21%. The effects of this processing on laser damage was characterized by the measuring the LIDT for the laser radiations of 355nm.

  7. Ion beam induces nitridation of silicon

    International Nuclear Information System (INIS)

    Petravic, M.; Williams, J.S.; Conway, M.

    1998-01-01

    High dose ion bombardment of silicon with reactive species, such as oxygen and nitrogen, has attracted considerable interest due to possible applications of beam-induced chemical compounds with silicon. For example, high energy oxygen bombardment of Si is now routinely used to form buried oxide layers for device purposes, the so called SIMOX structures. On the other hand, Si nitrides, formed by low energy ( 100 keV) nitrogen beam bombardment of Si, are attractive as oxidation barriers or gate insulators, primarily due to the low diffusivity of many species in Si nitrides. However, little data exists on silicon nitride formation during bombardment and its angle dependence, in particular for N 2 + bombardment in the 10 keV range, which is of interest for analytical techniques such as SIMS. In SIMS, low energy oxygen ions are more commonly used as bombarding species, as oxygen provides stable ion yields and enhances the positive secondary ion yield. Therefore, a large body of data can be found in the literature on oxide formation during low energy oxygen bombardment. Nitrogen bombardment of Si may cause similar effects to oxygen bombardment, as nitrogen and oxygen have similar masses and ranges in Si, show similar sputtering effects and both have the ability to form chemical compounds with Si. In this work we explore this possibility in some detail. We compare oxide and nitride formation during oxygen and nitrogen ion bombardment of Si under similar conditions. Despite the expected similar behaviour, some large differences in compound formation were found. These differences are explained in terms of different atomic diffusivities in oxides and nitrides, film structural differences and thermodynamic properties. (author)

  8. Formation of plasmid DNA strand breaks induced by low-energy ion beam: indication of nuclear stopping effects

    International Nuclear Information System (INIS)

    Chen Yu; Jiang Bingyao; Chen Youshan; Ding Xingzhao; Liu Xianghuai; Chen Ceshi; Guo Xinyou; Yin Guanglin

    1998-01-01

    Plasmid pGEM 3zf(+) was irradiated by nitrogen ion beam with energies between 20 and 100 keV and the fluence kept as 1 x 10 12 ions/cm 2 . The irradiated plasmid was assayed by neutral electrophoresis and quantified by densitometry. The yields of DNA with single-strand and double-strand breaks first increased then decreased with increasing ion energy. There was a maximal yield value in the range of 20-100 keV. The relationship between DNA double-strand breaks (DSB) cross-section and linear energy transfer (LET) also showed a peak-shaped distribution. To understand the physical process during DNA strand breaks, a Monte Carlo calculation code known as TRIM (Transport of Ions in Matter) was used to simulate energy losses due to nuclear stopping and to electronic stopping. It can be assumed that nuclear stopping plays a more important role in DNA strand breaks than electronic stopping in this energy range. The physical mechanisms of DNA strand breaks induced by a low-energy ion beam are also discussed. (orig.)

  9. Induced Kerr effects and self-guided beams in quasi-phase-matched quadratic media [CBC4

    DEFF Research Database (Denmark)

    Clausen, Carl A. Balslev; Bang, Ole; Kivshar, Yuri S.

    1997-01-01

    We show that quasi-phase-matching of quadratic media induces Kerr effects, such as self- and cross-phase modulation, and leads to the existence of a novel class of solitary waves, QPM-solitons......We show that quasi-phase-matching of quadratic media induces Kerr effects, such as self- and cross-phase modulation, and leads to the existence of a novel class of solitary waves, QPM-solitons...

  10. Beam-Induced Damage Mechanisms and their Calculation

    CERN Document Server

    Bertarelli, A

    2016-01-01

    The rapid interaction of highly energetic particle beams with matter induces dynamic responses in the impacted component. If the beam pulse is sufficiently intense, extreme conditions can be reached, such as very high pressures, changes of material density, phase transitions, intense stress waves, material fragmentation and explosions. Even at lower intensities and longer time-scales, significant effects may be induced, such as vibrations, large oscillations, and permanent deformation of the impacted components. These lectures provide an introduction to the mechanisms that govern the thermomechanical phenomena induced by the interaction between particle beams and solids and to the analytical and numerical methods that are available for assessing the response of impacted components. An overview of the design principles of such devices is also provided, along with descriptions of material selection guidelines and the experimental tests that are required to validate materials and components exposed to interactio...

  11. 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

    2016-07-07

    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 (12)C 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.

  12. RELAXATION OF BLAZAR-INDUCED PAIR BEAMS IN COSMIC VOIDS

    Energy Technology Data Exchange (ETDEWEB)

    Miniati, Francesco [Physics Department, Wolfgang-Pauli-Strasse 27, ETH-Zuerich, CH-8093 Zuerich (Switzerland); Elyiv, Andrii, E-mail: fm@phys.ethz.ch [Institut d' Astrophysique et de Geophysique, Universite de Liege, B-4000 Liege (Belgium)

    2013-06-10

    The stability properties of a low-density ultrarelativistic pair beam produced in the intergalactic medium (IGM) by multi-TeV gamma-ray photons from blazars are analyzed. The problem is relevant for probes of magnetic field in cosmic voids through gamma-ray observations. In addition, dissipation of such beams could considerably affect the thermal history of the IGM and structure formation. We use a Monte Carlo method to quantify the properties of the blazar-induced electromagnetic shower, in particular the bulk Lorentz factor and the angular spread of the pair beam generated by the shower, as a function of distance from the blazar itself. We then use linear and nonlinear kinetic theory to study the stability of the pair beam against the growth of electrostatic plasma waves, employing the Monte Carlo results for our quantitative estimates. We find that the fastest growing mode, like any perturbation mode with even a very modest component perpendicular to the beam direction, cannot be described in the reactive regime. Due to the effect of nonlinear Landau damping, which suppresses the growth of plasma oscillations, the beam relaxation timescale is found to be significantly longer than the inverse Compton loss time. Finally, density inhomogeneities associated with cosmic structure induce loss of resonance between the beam particles and plasma oscillations, strongly inhibiting their growth. We conclude that relativistic pair beams produced by blazars in the IGM are stable on timescales that are long compared with the electromagnetic cascades. There appears to be little or no effect of pair beams on the IGM.

  13. Mutation induced with ion beam irradiation in rose

    Science.gov (United States)

    Yamaguchi, H.; Nagatomi, S.; Morishita, T.; Degi, K.; Tanaka, A.; Shikazono, N.; Hase, Y.

    2003-05-01

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

  14. Strengthening effect of nano-scaled precipitates in Ta alloying layer induced by high current pulsed electron beam

    International Nuclear Information System (INIS)

    Tang, Guangze; Luo, Dian; Fan, Guohua; Ma, Xinxin; Wang, Liqin

    2017-01-01

    Highlights: • Ta alloying layer are fabricated by magnetron sputtering and high current pulsed electron beam. • Nano-scaled TaC precipitates forms within the δ-Fe grain after tempering treatment. • The mean diameter of TaC particles is about 5–8 nm. • The hardness of alloying layer increased by over 50% after formation of nano-scaled TaC particle. - Abstract: In this study, the combination of magnetron sputtering and high current pulsed electron beam are used for surface alloying treatment of Ta film on high speed steel. And the Ta alloying layer is about 6 μm. After tempering treatment, TaC phase forms in Ta alloying layer when the treated temperature is over 823 K. Through the TEM and HRTEM observation, a large amount of nano-scaled precipitates (mean diameter 5–8 nm) form within the δ-Fe grain in Ta alloying layer after tempering treatment and these nano-scaled precipitates are confirmed as TaC particles, which contribute to the strengthening effect of the surface alloying layer. The hardness of tempered alloying layer can reach to 18.1 GPa when the treated temperature is 823 K which increase by 50% comparing with the untreated steel sample before surface alloying treatment.

  15. Strengthening effect of nano-scaled precipitates in Ta alloying layer induced by high current pulsed electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Guangze; Luo, Dian; Fan, Guohua [School of Material Science & Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Xinxin, E-mail: maxin@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Wang, Liqin [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2017-05-01

    Highlights: • Ta alloying layer are fabricated by magnetron sputtering and high current pulsed electron beam. • Nano-scaled TaC precipitates forms within the δ-Fe grain after tempering treatment. • The mean diameter of TaC particles is about 5–8 nm. • The hardness of alloying layer increased by over 50% after formation of nano-scaled TaC particle. - Abstract: In this study, the combination of magnetron sputtering and high current pulsed electron beam are used for surface alloying treatment of Ta film on high speed steel. And the Ta alloying layer is about 6 μm. After tempering treatment, TaC phase forms in Ta alloying layer when the treated temperature is over 823 K. Through the TEM and HRTEM observation, a large amount of nano-scaled precipitates (mean diameter 5–8 nm) form within the δ-Fe grain in Ta alloying layer after tempering treatment and these nano-scaled precipitates are confirmed as TaC particles, which contribute to the strengthening effect of the surface alloying layer. The hardness of tempered alloying layer can reach to 18.1 GPa when the treated temperature is 823 K which increase by 50% comparing with the untreated steel sample before surface alloying treatment.

  16. Study of ion beam induced depolymerization using positron annihilation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Puglisi, O. E-mail: opuglisi@dipchi.unict.it; Fragala, M.E.; Lynn, K.G.; Petkov, M.; Weber, M.; Somoza, A.; Dupasquier, A.; Quasso, F

    2001-04-01

    Ion beam induced depolymerization of polymers is a special class of ion beam induced chemical reaction which gives rise to catastrophic 'unzipping' of macromolecules with production of large amounts of the monomer, of the order of many hundreds monomer molecules per each macromolecule. The possible modification of the density at microscopic level prompted us to undertake a study of this effect utilizing positron annihilation techniques in Poly(methylmethacrylate) (PMMA) before and after bombardment with He{sup +} 300 keV ions at 200 deg. C. Preliminary results shown here indicate that before bombardment there is a reproducible dependence of nano-hole distribution on the sample history. Moreover at 200 deg. C we do not detect formation of new cavities as a consequence of the strong depolymerization that occurs under the ion beam. The possible correlation of these findings with transport properties of PMMA at temperature higher than the glass transition temperature will be discussed.

  17. Spacecraft ion beam noise effects

    Science.gov (United States)

    Anenberg, G. L.

    1972-01-01

    An estimate of the antenna noise temperature and the uplink signal-to-noise ratio has been made for Bremsstrahlung radiation emitted by a spacecraft ion beam; a worst-case situation in which the spacecraft antenna is located in the exit plane of the ion beam and directed at varying angles into the ion beam is assumed. Numerical results of the antenna noise temperature versus antenna pointing angle are given for a typical set of ion beam and antenna pattern parameters. The uplink signal-to-noise ratio due to the ion beam noise alone is given in terms of a critical range in AU at which a typical ranging transmission is received with S/N = 0 db. The effects of the ion beam divergence angle and antenna distance on the ion beam are also presented. Results of the study show typical increases in the antenna noise temperature of about 0.2 K and critical ranges of the order of 3-5 AU. An ion engine thus generally introduces an undetectable level of noise into a spacecraft receiver.

  18. Proton beam induced dynamics of tungsten granules

    Science.gov (United States)

    Caretta, O.; Loveridge, P.; O'Dell, J.; Davenne, T.; Fitton, M.; Atherton, A.; Densham, C.; Charitonidis, N.; Efthymiopoulos, I.; Fabich, A.; Guinchard, M.; Lacny, L. J.; Lindstrom, B.

    2018-03-01

    This paper reports the results from single-pulse experiments of a 440 GeV /c proton beam interacting with granular tungsten samples in both vacuum and helium environments. Remote high-speed photography and laser Doppler vibrometry were used to observe the effect of the beam on the sample grains. The majority of the results were derived from a trough containing ˜45 μ m diameter spheres (not compacted) reset between experiments to maintain the same initial conditions. Experiments were also carried out on other open and contained samples for the purposes of comparison both with the 45 μ m grain results and with a previous experiment carried out with sub-250 μ m mixed crystalline tungsten powder in helium [Phys. Rev. ST Accel. Beams 17, 101005 (2014), 10.1103/PhysRevSTAB.17.101005]. The experiments demonstrate that a greater dynamic response is produced in a vacuum than in a helium environment and in smaller grains compared with larger grains. The examination of the dynamics of the grains after a beam impact leads to the hypothesis that the grain response is primarily the result of a charge interaction of the proton beam with the granular medium.

  19. Beam-beam simulations: dynamical effects and beam-beam limit for LEP3

    CERN Document Server

    Ohmi, K

    2012-01-01

    Beam-beam simulations are reported for LEP3 and TLEP-H, including a rough tune scan. The results suggest that to achieve the design luminosity in LEP3, 10% higher bunch population may be necessary, while TLEP-H can achieve the design performance without any changes. The simulations indicate that the large synchrotron tune, in conjunction with a large hourglass effect, degrades the luminosity performance. This talk was given at CERN on 4 December 2012.

  20. Coherent Beam-Beam Effects in the LHC

    CERN Document Server

    Alexahin, Yu I; Herr, Werner; Zorzano-Mier, M P

    2001-01-01

    In the Large Hadron Collider (LHC) two proton beams of similar intensities collide in several interaction points. It is well known that the head-on collision of two beams of equal strength can excite coherent modes whose frequencies are separated from the incoherent spectrum of oscillations of individual particles. This can lead to the loss of Landau damping and possibly to unstable motion. The beam-beam effect in the LHC is further complicated by a large number of bunches (2808 per beam), a finite crossing angle and gaps in the bunch train. The coherent beam-beam effects under various conditions and operational scenarios are studied analytically and with multiparticle simulations. We give an overview of the main results and present proposals to overcome these difficulties together with possible side effects.

  1. The effect of electron range on electron beam induced current collection and a simple method to extract an electron range for any generation function

    International Nuclear Information System (INIS)

    Lahreche, A.; Beggah, Y.; Corkish, R.

    2011-01-01

    The effect of electron range on electron beam induced current (EBIC) is demonstrated and the problem of the choice of the optimal electron ranges to use with simple uniform and point generation function models is resolved by proposing a method to extract an electron range-energy relationship (ERER). The results show that the use of these extracted electron ranges remove the previous disagreement between the EBIC curves computed with simple forms of generation model and those based on a more realistic generation model. The impact of these extracted electron ranges on the extraction of diffusion length, surface recombination velocity and EBIC contrast of defects is discussed. It is also demonstrated that, for the case of uniform generation, the computed EBIC current is independent of the assumed shape of the generation volume. -- Highlights: → Effect of electron ranges on modeling electron beam induced current is shown. → A method to extract an electron range for simple form of generation is proposed. → For uniform generation the EBIC current is independent of the choice of it shape. → Uses of the extracted electron ranges remove some existing literature ambiguity.

  2. Spectrometer for cluster ion beam induced luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Ryuto, H., E-mail: ryuto@kuee.kyoto-u.ac.jp; Sakata, A.; Takeuchi, M.; Takaoka, G. H. [Photonics and Electronics Science and Engineering Center, Kyoto University, Kyoto 615-8510 (Japan); Musumeci, F. [Department of Physics and Astronomy, Catania University, Catania 95123 (Italy); INFN Laboratori Nazionali del Sud, Catania 95123 (Italy)

    2015-02-15

    A spectrometer to detect the ultra-weak luminescence originated by the collision of cluster ions on the surfaces of solid materials was constructed. This spectrometer consists of 11 photomultipliers with band-pass interference filters that can detect the luminescence within the wavelength ranging from 300 to 700 nm and of a photomultiplier without filter. The calibration of the detection system was performed using the photons emitted from a strontium aluminate fluorescent tape and from a high temperature tungsten filament. Preliminary measurements show the ability of this spectrometer to detect the cluster ion beam induced luminescence.

  3. Strategies for mitigating the ionization-induced beam head erosion problem in an electron-beam-driven plasma wakefield accelerator

    Directory of Open Access Journals (Sweden)

    W. An

    2013-10-01

    Full Text Available Strategies for mitigating ionization-induced beam head erosion in an electron-beam-driven plasma wakefield accelerator (PWFA are explored when the plasma and the wake are both formed by the transverse electric field of the beam itself. Beam head erosion can occur in a preformed plasma because of a lack of focusing force from the wake at the rising edge (head of the beam due to the finite inertia of the electrons. When the plasma is produced by field ionization from the space charge field of the beam, the head erosion is significantly exacerbated due to the gradual recession (in the beam frame of the 100% ionization contour. Beam particles in front of the ionization front cannot be focused (guided causing them to expand as in vacuum. When they expand, the location of the ionization front recedes such that even more beam particles are completely unguided. Eventually this process terminates the wake formation prematurely, i.e., well before the beam is depleted of its energy. Ionization-induced head erosion can be mitigated by controlling the beam parameters (emittance, charge, and energy and/or the plasma conditions. In this paper we explore how the latter can be optimized so as to extend the beam propagation distance and thereby increase the energy gain. In particular we show that, by using a combination of the alkali atoms of the lowest practical ionization potential (Cs for plasma formation and a precursor laser pulse to generate a narrow plasma filament in front of the beam, the head erosion rate can be dramatically reduced. Simulation results show that in the upcoming “two-bunch PWFA experiments” on the FACET facility at SLAC national accelerator laboratory the energy gain of the trailing beam can be up to 10 times larger for the given parameters when employing these techniques. Comparison of the effect of beam head erosion in preformed and ionization produced plasmas is also presented.

  4. Analysis of beam loss induced abort kicker instability

    Energy Technology Data Exchange (ETDEWEB)

    Zhang W.; Sandberg, J.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Pai, C.; Tan, Y.

    2012-05-20

    Through more than a decade of operation, we have noticed the phenomena of beam loss induced kicker instability in the RHIC beam abort systems. In this study, we analyze the short term beam loss before abort kicker pre-fire events and operation conditions before capacitor failures. Beam loss has caused capacitor failures and elevated radiation level concentrated at failed end of capacitor has been observed. We are interested in beam loss induced radiation and heat dissipation in large oil filled capacitors and beam triggered thyratron conduction. We hope the analysis result would lead to better protection of the abort systems and improved stability of the RHIC operation.

  5. Measurement and simulation of the effects of ion-induced defects on ion beam-induced charge (IBIC) measurements in Si schottky diodes

    International Nuclear Information System (INIS)

    Hearne, S.M.; Lay, M.D.H.; Jamieson, D.N.

    2004-01-01

    Full text: The Ion Beam Induced Charge (IBIC) technique is a very sensitive tool for investigating the electronic properties of semiconductor materials and devices. However, obtaining quantitative information from IBIC experiments requires an accurate model of the materials properties. The interaction of high energy ions with crystalline materials is known to create point defects within the crystal. A significant proportion of defects introduced by the interaction of the ion with the crystal are electrically active and are therefore an important consideration when undertaking an IBIC experiment. The goal of this work is to investigate the possibility of including the relevant defect parameters in computer simulations of the IBIC experiment implemented using Technology Computer Aided Design (TCAD) software. We will present the results from an IBIC study on Si Schottky diodes using 1 MeV alphas. A reduction of greater than 50% in the detected IBIC signal was observed for fluences greater than 5x10 10 He + /cm 2 . The trap parameters following ion irradiation were determined experimentally using DLTS. Comparisons between the experimental IBIC results and TCAD simulations will be discussed

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

    Directory of Open Access Journals (Sweden)

    W. Fischer

    2017-09-01

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

  7. Development of chloride-induced corrosion in pre-cracked RC beams under sustained loading: Effect of load-induced cracks, concrete cover, and exposure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Linwen [Université de Toulouse, UPS, INSA, LMDC, Toulouse (France); Université de Sherbrooke, Quebec (Canada); François, Raoul, E-mail: raoul.francois@insa-toulouse.fr [Université de Toulouse, UPS, INSA, LMDC, Toulouse (France); Dang, Vu Hiep [Hanoi Architectural University, Faculty of Civil Engineering, Hanoi (Viet Nam); L' Hostis, Valérie [CEA Saclay, CEA, DEN, DPC, SECR, Laboratoire d' Etude du Comportement des Bétons et des Argiles, Gif-sur-Yvette (France); Gagné, Richard [Université de Sherbrooke, Quebec (Canada)

    2015-01-15

    This paper deals with corrosion initiation and propagation in pre-cracked reinforced concrete beams under sustained loading during exposure to a chloride environment. Specimen beams that were cast in 2010 were compared to specimens cast in 1984. The only differences between the two sets of beams were the casting direction in relation to tensile reinforcement and the exposure conditions in the salt-fog chamber. The cracking maps, corrosion maps, chloride profiles, and cross-sectional loss of one group of two beams cast in 2010 were studied and their calculated corrosion rates were compared to that of beams cast in 1984 in order to investigate the factors influencing the natural corrosion process. Experimental results show that, after rapid initiation of corrosion at the crack tip, the corrosion process practically halted and the time elapsing before corrosion resumed depended on the exposure conditions and cover depth.

  8. Beam-beam instability driven by wakefield effects in linear colliders

    CERN Document Server

    Brinkmann, R; Schulte, Daniel

    2002-01-01

    The vertical beam profile distortions induced by wakefield effects in linear colliders (the so-called ``banana effect'') generate a beam-beam instability at the collision point when the vertical disruption parameter is large. We illustrate this effect in the case of the TESLA linear collider project. We specify the tolerance on the associated emittance growth, which translates into tolerances on injection jitter and, for a given tuning procedure, on structure misalignments. We look for possible cures based on fast orbit correction at the interaction point and using a fast luminosity monitor.

  9. Electron beam induced conductivity in 'PET' and 'FEP'

    International Nuclear Information System (INIS)

    Walzade, S.J.; Jog, J.P.; Dake, S.B.; Bhoraskar, S.V.

    1983-01-01

    Electron Beam Induced Conductivity (EBIC), classified into EBIC (bulk) and EBIC (surface) have been measured in PET and FEP respectively. The peculiar oscillatory nature of the induced gain versus beam energy variations is explained in terms of the spatial distributions of the trapping centres near the surface of the polymers. (author)

  10. Transverse Periodic Beam Loading Effects in a Storage Ring

    International Nuclear Information System (INIS)

    Thompson, J.R.; Byrd, J.M.

    2009-01-01

    Uneven beam fill patterns in storage rings, such as gaps in the fill patterns, leads to periodic, or transient loading of the modes of the RF cavities. We show that an analogous effect can occur in the loading of a dipole cavity mode when the beam passes off the electrical center of the cavity mode. Although this effect is small, it results in a variation of the transverse offset of the beam along the bunch train. For ultralow emittance beams, such as optimized third generation light sources and damping rings, this effect results in a larger projected emittance of the beam compared with the single bunch emittance. The effect is particularly strong for the case when a strong dipole mode has been purposely added to the ring, such as a deflecting, or 'crab' cavity. We derive an approximate analytic solution for the variation of the beam-induced deflecting voltage along the bunch train.

  11. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  12. Overview of Beam-Beam Effects in the Tevatron

    CERN Document Server

    Shiltsev, V.

    2014-01-01

    For almost a quarter of a century the Tevatron proton-antiproton collider was the centrepiece of the world's high-energy physics program, from the start of operation in December 1985 until it was overtaken by the LHC in 2011. The initial design luminosity of the Tevatron was 1030 cm-2 s-1; however, as a result of two decades of upgrades, the accelerator has been able to deliver 430-times higher luminosities to each of two high-luminosity experiments, Collider Detector at Fermilab (CDF) and D0. On the way to record high luminosities, many issues related to the electromagnetic beam-beam interaction of colliding beams have been addressed. Below we present a short overview of the beam-beam effects in the Tevatron.

  13. Carbon ion beam is more effective to induce cell death in sphere-type A172 human glioblastoma cells compared with X-rays.

    Science.gov (United States)

    Takahashi, Momoko; Hirakawa, Hirokazu; Yajima, Hirohiko; Izumi-Nakajima, Nakako; Okayasu, Ryuichi; Fujimori, Akira

    2014-12-01

    To obtain human glioblastoma cells A172 expressing stem cell-related protein and comparison of radiosensitivity in these cells with X-rays and carbon beam. Human monolayer-type A172 glioblastoma cells were maintained in normal medium with 10% bovine serum. In order to obtain sphere-type A172 cells the medium was replaced with serum-free medium supplemented with growth factors. Both types of A172 cells were irradiated with either X-rays or carbon ion beams and their radiosensitivity was evaluated. Serum-free medium induced expression of stem cell-related proteins in A172 cells along with the neurosphere-like appearance. These sphere-type cells were found resistant to both X-rays and carbon ion beams. Phosphorylation of histone H2A family member X persisted for a longer period in the cells exposed to carbon ion beams than in those exposed to X-rays and it disappeared quicker in the sphere type than in the monolayer type. Relative radioresistance of the sphere type cells was smaller for carbon ion beams than for X-rays. We demonstrated that glioblastoma A172 cells with induced stem cell-related proteins turned resistant to irradiation. Accelerated heavy ion particles may have advantage over X-rays in overcoming the tumor resistance due to cell stemness.

  14. Tunable twin Airy beams induced by binary phase patterns.

    Science.gov (United States)

    Fan, Yongtao; Wei, Jingsong; Ma, Jianyong; Wang, Yang; Wu, Yiqun

    2013-04-15

    In this work, we theoretically and experimentally study the physical process of Airy beams induced by binary phase patterns combined with a slope factor. Theoretical simulations show that the binary phase patterns generate a pair of symmetrically inverted twin Airy beams. The slope factor can regulate the spacing between the two Airy beam peaks, decrease the error induced by the binarization process, and adjust the position of the focus formed by the twin Airy beams. The experimental results are consistent with the theoretical ones.

  15. Beam-beam effects and generalized luminosity

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J.E.

    1996-01-01

    The assumption is made that before an NLC is approved, a prototype will be necessary that demonstrates the feasibility of a general purpose linear collider capable of {rvec e}{sup {+-}}{rvec e}{sup {+-}}, {rvec {gamma}}{rvec e} and {rvec {gamma}}{rvec {gamma}} incident channels. At an upgraded SLC, such channels could provide new physics over a range of energies upwards of a few GeV. Effects that limit the luminosity of a GLC are discussed together with their possible mitigations. The expected luminosities in the different channels are then predicted in a consistent way for {radical}s{sub ee} = 0.5 TeV.

  16. Influence of plasma-induced energy deposition effects, the equation of state, thermal ionization, pulse shaping, and radiation on ion-beam-driven expansions of plane metal targets

    International Nuclear Information System (INIS)

    Long, K.A.; Tahir, N.A.

    1986-01-01

    In a previous paper by Long and Tahir [Phys. Fluids 29, 275 (1986)], the motion of plane targets irradiated by ion beams whose energy deposition was assumed to be independent of the ion energy, and the temperature and density of the plasma, was analyzed. In this paper, the analytic solution is extended in order to include the effects of a temperature-and density-dependent energy deposition as a result of electron excitation, an improved equation of state, thermal ionization, a pulse shape, and radiation losses. The change in the energy deposition with temperature and density leads to range shortening and an increased power deposition in the target. It is shown how the analytic theory can be used to analyze experiments to measure the enhanced energy deposition. In order to further analyze experiments, numerical simulations are presented which include the plasma-induced effects on the energy deposition. It is shown that since the change in the range is due to both decrease in density and the increase in temperature, it is not possible to separate these two effects in present experiments. Therefore, the experiments which measure the time-dependent energy of the ions emerging from the back side of a plane target do not as yet measure the energy loss as a function of the density and temperature of the plasma or of the energy of the ion, but only an averaged loss over certain ranges of these physical quantities

  17. Ion and laser beam induced metastable alloy formation

    International Nuclear Information System (INIS)

    Westendorp, J.F.M.

    1986-01-01

    This thesis deals with ion and laser beam induced thin film mixing. It describes the development of an Ultra High Vacuum apparatus for deposition, ion irradiation and in situ analysis of thin film sandwiches. This chamber has been developed in close collaboration with High Voltage Engineering Europa. Thin films can be deposited by an e-gun evaporator. The atom flux is monitored by a quadrupole mass spectrometer. A comparison is made between ion beam and laser mixing of Cu with Au and Cu with W. The comparison provides a better understanding of the relative importance of purely collisional mixing, the role of thermodynamic effects and the contribution of diffusion due to defect generation and migration. (Auth.)

  18. Beam loading effects for two-beam ring

    International Nuclear Information System (INIS)

    Wang Lanfa; Lin Yuzheng; Tong Dechun

    1999-01-01

    An analytic treatment of multi-bunch potential well distortion for a two-beam storage ring is presented. The longitudinal wake effects are separated into: the mode loss, the synchrotron tune shift (both due to potential well distortion) and the coherent multi-bunch coupling. Here, only the first two effects are studied. Resulting simple analytic formulas describe the mode loss and the synchrotron tune shift experienced by a given bunch within the two-beam, as a function of the high order mode's parameters. One can get immediately a simple quantitative answer in term of the mode loss and the synchrotron tune shift experienced by each bunch from these formulas, so the authors can know how to modify the existing configuration of parasitic cavity resonance (via frequency tuning) so that the resulting potential well distortion effects are minimized. When the RF cavities are symmetrically distributed about the interaction points, the two beams will have same beam loading effects, so the authors can compensate the phase shift of the two beam using the same method as in one beam case

  19. Multi-electron beam system for high resolution electron beam induced deposition

    NARCIS (Netherlands)

    Van Bruggen, M.J.

    2008-01-01

    The development of a multi-electron beam system is described which is dedicated for electron beam induced deposition (EBID) with sub-10 nm resolution. EBID is a promising mask-less nanolithography technique which has the potential to become a viable technique for the fabrication of 20-2 nm

  20. Simulating Transient Effects of Pulsed Beams on Beam Intercepting Devices

    CERN Document Server

    Richter, Herta; Noah Messomo, Etam

    2011-01-01

    The development in the physics community towards higher beam power through the possibilities of particle accelerators lead to challenges for the developers of elements which are exposed to effect of particle beams (beam intercepting devices = BIDs). For the design of BIDs, the increasing heat load onto these devices due to energetic and focused beams and - in most cases - their highly pulsed nature has to be taken into account. The physics requirements are sometimes opposed to the current state of the art. As one possibility of many in combining the different aspects for these ambitious demands, two highly developed computer programs, namely FLUKA and ANSYS AUTODYN, were joined for this dissertation. The former is a widely enhanced Monte-Carlo-code which specializes on the interaction of particles with static matter, while the latter is a versatile explicit code for the simulation of highly dynamic processes. Both computer programs were developed intensively over years and are still continuously enhanced in o...

  1. Disruption effects on the beam size measurement

    International Nuclear Information System (INIS)

    Raimondi, P.; Decker, F.J.; Chen, P.

    1995-01-01

    At the SLC Final Focus with higher currents and smaller beam sizes, the disruption parameter D y is close to one and so the pinch effect should produce a luminosity enhancement. Since a flat beam-beam function is fit to deflection scan data to measure the beam size, disruption can affect the measurement. Here the authors discuss the quantitative effects of disruption for typical SLC beam parameters. With 3.5 10 10 particles per pulse, bunch length of 0.8 mm and beam sizes of 2.1 μm horizontally and 0.55 μm vertically, the measured vertical size can be as much as 25% bigger than the real one. Furthermore during the collision the spot size actually decrease, producing an enhancement factor H D of about 1.25. This would yield to a true luminosity which is 1.6 times that which is estimated from the beam-beam deflection fit

  2. Investigations on ion-beam induced desorption from cryogenic surfaces

    International Nuclear Information System (INIS)

    Maurer, Christoph

    2017-01-01

    pumps can be taken into account. This method can be extended to any desorption experiment employing the single shot method for measurement. Of special interest for the operation of the SIS100 at high intensities is the minimization of desorption from cryogenic surfaces. A previous examination of this topic found a breakdown of the familiar scaling of the desorption yield with the beam's energy loss for cryogenic targets. Further examination of this effect with the techniques described above is another goal of this thesis. Simultaneously, desorption measurements at room temperature for several other targets have been conducted. An unexpected result of these experiments is the influence of target surface properties, which was found to be very weak in comparison to previous results. The methods developed during this thesis, along with the results gained by their application, represent another step towards the comprehension of (heavy) ion beam induced desorption.

  3. 3D assembly of carbon nanotubes for fabrication of field-effect transistors through nanomanipulation and electron-beam-induced deposition

    Science.gov (United States)

    Yu, Ning; Shi, Qing; Nakajima, Masahiro; Wang, Huaping; Yang, Zhan; Sun, Lining; Huang, Qiang; Fukuda, Toshio

    2017-10-01

    Three-dimensional carbon nanotube field-effect transistors (3D CNTFETs) possess predictable characteristics that rival those of planar CNTFETs and Si-based MOSFETs. However, due to the lack of a reliable assembly technology, they are rarely reported on, despite the amount of attention they receive. To address this problem, we propose the novel concept of a 3D CNTFET and develop its assembly strategy based on nanomanipulation and the electron-beam-induced deposition (EBID) technique inside a scanning electron microscope (SEM). In particular, the electrodes in our transistor design are three metallic cuboids of the same size, and their front, top and back surfaces are all wrapped up in CNTs. The assembly strategy is employed to build the structure through a repeated basic process of pick-up, placement, fixing and cutting of CNTs. The pick-up and placement is performed through one nanomanipulator with four degrees of freedom. Fixing is carried out through the EBID technique so as to improve the mechanical and electrical characteristics of the CNT/electrodes connection. CNT cutting is undertaken using the typical method of electrical breakdown. Experimental results showed that two CNTs were successfully assembled on the front sides of the cubic electrodes. This validates our assembly method for the 3D CNTFET. Also, when contact resistance was measured, tens of kilohms of resistance was observed at the CNT-EBID deposition-FET electrodes junction.. This manifests the electrical reliability of our assembly strategy.

  4. First LHC beam induced tracks reconstructed in the LHCb VELO

    CERN Document Server

    Parkes, C; Bates, A; Eklund, L; Gersabeck, M; Marinho, F; Rakotomiaramanana, B; Rodrigues, E; Szumlak, T; Affolder, A; Bowcock, T; Casse, G; Donleavy, S; Hennessy, K; Huse, T; Hutchcroft, D; Mylroie-Smith, J; Noor, A; Patel, G; Rinnert, K; Smith, N A; Shears, T; Tobin, M; John, M; Bay, A; Frei, R; Haefeli, G; Keune, A; Anderson, J; McNulty, R; Traynor, S; Basiladze, S; Leflat, A; Artuso, M; Borgia, A; Lefeuvre, G; Mountain, R; Wang, J; Akiba, K; van Beuzekom, M; Jans, E; Ketel, T; Mous, I; Papadelis, A; Van Lysebetten, A; Verlaat, B; de Vries, H; Behrendt, O; Buytaert, J; de Capua, S; Collins, P; Ferro-Luzzi, M

    2009-01-01

    The Vertex Locator of the LHCb experiment has been used to fully reconstruct beam induced tracks at the LHC. A beam of protons was collided with a beam absorber during the LHC synchronisation test of the anti-clockwise beam on the weekend 22nd–24th August 2008. The resulting particles have been observed by the Vertex Locator. The LHCb Vertex Locator is a silicon micro-strip detector containing 21 planes of modules. Tracks were observed passing through up to 19 modules (38 silicon sensors). A total of over 700 tracks were reconstructed, and are being used to study the calibration and alignment of the detector.

  5. Electron beam induced heat flow transient in aluminium

    International Nuclear Information System (INIS)

    Dalle Rose, L.F.D.; Brotto, R.

    1983-01-01

    On the basis of a numerically solved heat diffusion equation, the structure of the thermal transient induced in an aluminium sample by an electron beam pulse is described in terms of slush zone formation, molten depth, liquid phase duration, and melt front history. The heat flow dynamics, as determined by monochromatic (electron energy ranging between 5 and 25 keV) and ultrashort (15 ns fwhm) pulses, is contrasted with the ruby laser induced one. Accessible absorbed energy intervals for sample surface melting are given as a function of electron energy; heating of the sample interior at values higher than those attained at the surface is shown to occur only at higher electron energies, for a given pulse duration. The general dependence of the present results on the pulse duration and the effects produced by polychromatic pulses are also discussed. (author)

  6. 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.

  7. Beam-induced quench test of LHC main quadrupole

    CERN Document Server

    Priebe, A; Dehning, B; Effinger, E; Emery, J; Holzer, E B; Kurfuerst, C; Nebot Del Busto, E; Nordt, A; Sapinski, M; Steckert, J; Verweij, A; Zamantzas, C

    2011-01-01

    Unexpected beam loss might lead to a transition of the accelerator superconducting magnet to a normal conducting state. The LHC beam loss monitoring (BLM) system is designed to abort the beam before the energy deposited in the magnet coils reach a quench-provoking level. In order to verify the threshold settings generated by simulation, a series of beam-induced quench tests at various beam energies has been performed. The beam losses are generated by means of an orbital bump peaked in one of main quadrupole magnets (MQ). The analysis includes not only BLM data but also the quench protection system (QPS) and cryogenics data. The measurements are compared to Geant4 simulations of energy deposition inside the coils and corresponding BLM signal outside the cryostat.

  8. Multi-scale approach to radiation damage induced by ion beams: complex DNA damage and effects of thermal spikes

    International Nuclear Information System (INIS)

    Surdutovich, E.; Yakubovich, A.V.; Solov'yov, A.V.; Surdutovich, E.; Yakubovich, A.V.; Solov'yov, A.V.

    2010-01-01

    We present the latest advances of the multi-scale approach to radiation damage caused by irradiation of a tissue with energetic ions and report the calculations of complex DNA damage and the effects of thermal spikes on biomolecules. The multi-scale approach aims to quantify the most important physical, chemical, and biological phenomena taking place during and following irradiation with ions and provide a better means for clinically-necessary calculations with adequate accuracy. We suggest a way of quantifying the complex clustered damage, one of the most important features of the radiation damage caused by ions. This quantification allows the studying of how the clusterization of DNA lesions affects the lethality of damage. We discuss the first results of molecular dynamics simulations of ubiquitin in the environment of thermal spikes, predicted to occur in tissue for a short time after an ion's passage in the vicinity of the ions' tracks. (authors)

  9. Generalized melting criterion for beam-induced amorphization

    International Nuclear Information System (INIS)

    Lam, N. Q.; Okamoto, Paul R.

    1993-09-01

    Recent studies have shown that the mean-square static atomic displacements provide a generic measure of the enthalpy stored in the lattice in the form of chemical and topological disorder, and that the effect of the displacements on the softening of shear elastic constants is identical to that of heating. This finding lends support to a generalized form of the Lindemann phenomenological melting criterion and leads to a natural interpretion of crystalline-to-amorphous transformations as defect-induced melting of metastable crystals driven beyond a critical state of disorder where the melting temperature falls below the glass-transition temperature. Application of the generalized Lindemann criterion to both the crystalline and amorphous phases indicates that the enthalpies of the two phases become identical when their shear moduli become equal. This thermo-elastic rule provides a basis for predicting the relative susceptibility of compounds to amorphization in terms of their elastic properties as measured by Debye temperatures. The present approach can explain many of the basic findings on beam-induced amorphization of intermetallic compounds as well as amorphous phase formation associated with ion implantation, ion-beam mixing and other solid-state processes

  10. Impact of large beam-induced heat loads on the transient operation of the beam screens and the cryogenic plants of the Future Circular Collider (FCC)

    Science.gov (United States)

    Correia Rodrigues, H.; Tavian, L.

    2017-12-01

    The Future Circular Collider (FCC) under study at CERN will produce 50-TeV high-energy proton beams. The high-energy particle beams are bent by 16-T superconducting dipole magnets operating at 1.9 K and distributed over a circumference of 80 km. The circulating beams induce 5 MW of dynamic heat loads by several processes such as synchrotron radiation, resistive dissipation of beam image currents and electron clouds. These beam-induced heat loads will be intercepted by beam screens operating between 40 and 60 K and induce transients during beam injection. Energy ramp-up and beam dumping on the distributed beam-screen cooling loops, the sector cryogenic plants and the dedicated circulators. Based on the current baseline parameters, numerical simulations of the fluid flow in the cryogenic distribution system during a beam operation cycle were performed. The effects of the thermal inertia of the headers on the helium flow temperature at the cryogenic plant inlet as well as the temperature gradient experienced by the beam screen has been assessed. Additionally, this work enabled a thorough exergetic analysis of different cryogenic plant configurations and laid the building-block for establishing design specification of cold and warm circulators.

  11. Ion beam irradiation effects on aromatic polymers

    International Nuclear Information System (INIS)

    Shukushima, Satoshi; Ueno, Keiji

    1995-01-01

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

  12. Radiation effects of ion beams on polymers

    International Nuclear Information System (INIS)

    Tagawa, Seiichi

    1993-01-01

    Recent progress in the radiation effects of ion beams on polymers are reviewed briefly. Our recent work on the radiation effects of ion beams on polystyrene thin films on silicon wafers and time resolved emission studies on polymers are described. (orig.)

  13. Surface Resistance Measurements and Estimate of the Beam-Induced Resistive Wall Heating of the LHC Dipole Beam Screen

    CERN Document Server

    Caspers, Friedhelm; Ruggiero, F; Tan, J

    1999-01-01

    An estimate of the resistive losses in the LHC beam screen is given from cold surface resistance measurements using the shielded pair technique, with particular emphasis on the effect of a high magnetic field. Two different copper coating methods, namely electro-deposition and co-lamination, have been evaluated. Experimental data are compared with theories including the anomalous skin effect and the magneto-resistance effect. It is shown whether the theory underestimates or not the losses depends strongly on the RRR value, on the magnetic field and on the surface characteristics. In the pessimistic case and for nominal machine parameters, the estimated beam-induced resistive wall heating can be as large as 260 mW/m for two circulating beams.

  14. Numerical simulation of inducing characteristics of high energy electron beam plasma for aerodynamics applications

    Science.gov (United States)

    Deng, Yongfeng; Jiang, Jian; Han, Xianwei; Tan, Chang; Wei, Jianguo

    2017-04-01

    The problem of flow active control by low temperature plasma is considered to be one of the most flourishing fields of aerodynamics due to its practical advantages. Compared with other means, the electron beam plasma is a potential flow control method for large scale flow. In this paper, a computational fluid dynamics model coupled with a multi-fluid plasma model is established to investigate the aerodynamic characteristics induced by electron beam plasma. The results demonstrate that the electron beam strongly influences the flow properties, not only in the boundary layers, but also in the main flow. A weak shockwave is induced at the electron beam injection position and develops to the other side of the wind tunnel behind the beam. It brings additional energy into air, and the inducing characteristics are closely related to the beam power and increase nonlinearly with it. The injection angles also influence the flow properties to some extent. Based on this research, we demonstrate that the high energy electron beam air plasma has three attractive advantages in aerodynamic applications, i.e. the high energy density, wide action range and excellent action effect. Due to the rapid development of near space hypersonic vehicles and atmospheric fighters, by optimizing the parameters, the electron beam can be used as an alternative means in aerodynamic steering in these applications.

  15. Stability of beam-induced tensor pressure tokamaks

    International Nuclear Information System (INIS)

    Cooper, W.A.; Nelson, D.B.; Bateman, G.; Kammash, T.

    1979-10-01

    Necessary and sufficient criteria are obtained for the high toroidal mode number stability of a guiding center plasma in low aspect ratio, D-shaped, beam-induced tensor pressure tokamaks. The difference between the two criteria is significant for interchange stability, while the difference is small for ballooning stability. The critical β value imposed by stability to ballooning modes is higher for perpendicular than for parallel beam injection

  16. An optimized nanoparticle separator enabled by electron beam induced deposition

    International Nuclear Information System (INIS)

    Fowlkes, J D; Rack, P D; Doktycz, M J

    2010-01-01

    Size-based separations technologies will inevitably benefit from advances in nanotechnology. Direct-write nanofabrication provides a useful mechanism for depositing/etching nanoscale elements in environments otherwise inaccessible to conventional nanofabrication techniques. Here, electron beam induced deposition was used to deposit an array of nanoscale features in a 3D environment with minimal material proximity effects outside the beam-interaction region. Specifically, the membrane component of a nanoparticle separator was fabricated by depositing a linear array of sharply tipped nanopillars, with a singular pitch, designed for sub-50 nm nanoparticle permeability. The nanopillar membrane was used in a dual capacity to control the flow of nanoparticles in the transaxial direction of the array while facilitating the sealing of the cellular-sized compartment in the paraxial direction. An optimized growth recipe resulted which (1) maximized the growth efficiency of the membrane (which minimizes proximity effects) and (2) preserved the fidelity of the spacing between nanopillars (which maximizes the size-based gating quality of the membrane) while (3) maintaining sharp nanopillar apexes for impaling an optically transparent polymeric lid critical for device sealing.

  17. Beam-induced heat loads on the beam screens of the inner triplets for the HL-LHC

    CERN Document Server

    Skripka, Galina; CERN. Geneva. ATS Department

    2018-01-01

    The expected heat load induced on the beam screens has been evaluated for the triplet assemblies in the four experimental Insertion Regions (IRs) of the HL-LHC. The contribution from electron cloud effects has been estimated using PyECLOUD macroparticle simulations. The presence of a surface treatment for the reduction of the Secondary Electron Yield has been taken into account. The contribution from the impedance of the beam screen has been evaluated taking into account the impact of the temperature and of the magnetic field on the resistivity of the surface.

  18. Beam-induced backgrounds in detectors at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Adrian

    2008-11-15

    There is general consensus in the high-energy physics community that the next particle collider to be built should be a linear electron-positron accelerator. Such a machine, colliding point-like particles with a well-defined initial state, would be an ideal complement to the Large Hadron Collider (LHC) and would allow high-precision measurements of the new physics phenomena that are likely to be discovered at the TeV energy scale. The most advanced project in that context is the International Linear Collider (ILC), aiming for a centre-of-mass energy of 500 GeV and a luminosity of 2 x 10{sup 34} cm{sup -2}s{sup -1} in its first stage. One of the detector concepts that are currently being developed and studied is the so-called International Large Detector (ILD). A prime feature of the ILD concept is the usage of a Time Projection Chamber (TPC) as the main tracker, which allows to reach the required momentum resolution, but which also has excellent particle identification capabilities and a highly robust and efficient tracking. The beam-beam interaction of the strongly focused particle bunches at the ILC will produce beamstrahlung photons, which can in turn scatter to electron-positron pairs. These pairs are a major source of detector backgrounds. This thesis explains the methods to study the effects of beam-induced electron-positron pair backgrounds with Mokka, a full detector simulation for the ILC that is based on Geant4, and it presents the simulation results for different detector configurations and various small modifications. The main focus of the simulations and their analysis is on the vertex detector and the TPC, but results for the inner silicon trackers and the hadronic calorimeters are shown as well. (orig.)

  19. Beam-induced backgrounds in detectors at the ILC

    International Nuclear Information System (INIS)

    Vogel, Adrian

    2008-11-01

    There is general consensus in the high-energy physics community that the next particle collider to be built should be a linear electron-positron accelerator. Such a machine, colliding point-like particles with a well-defined initial state, would be an ideal complement to the Large Hadron Collider (LHC) and would allow high-precision measurements of the new physics phenomena that are likely to be discovered at the TeV energy scale. The most advanced project in that context is the International Linear Collider (ILC), aiming for a centre-of-mass energy of 500 GeV and a luminosity of 2 x 10 34 cm -2 s -1 in its first stage. One of the detector concepts that are currently being developed and studied is the so-called International Large Detector (ILD). A prime feature of the ILD concept is the usage of a Time Projection Chamber (TPC) as the main tracker, which allows to reach the required momentum resolution, but which also has excellent particle identification capabilities and a highly robust and efficient tracking. The beam-beam interaction of the strongly focused particle bunches at the ILC will produce beamstrahlung photons, which can in turn scatter to electron-positron pairs. These pairs are a major source of detector backgrounds. This thesis explains the methods to study the effects of beam-induced electron-positron pair backgrounds with Mokka, a full detector simulation for the ILC that is based on Geant4, and it presents the simulation results for different detector configurations and various small modifications. The main focus of the simulations and their analysis is on the vertex detector and the TPC, but results for the inner silicon trackers and the hadronic calorimeters are shown as well. (orig.)

  20. Electron-beam induced conduction in some polymers

    International Nuclear Information System (INIS)

    Suzuoki, Yasuo; Mizutani, Teruyoshi; Ieda, Masayuki

    1976-01-01

    The charge signal induced by pulsed electron beam consists of two components, i.e. the fast and the slow components. The slow component which corresponds to carrier transport via shallow traps exhibited an asymmetry with respect to the bias field polarity. The asymmetry revealed that the main carriers which drifted via shallow traps were electrons in PET, both electrons and holes in PEN, and holes in PS. TSC spectra of electron-beam induced electrets proved directly the existence of electron shallow traps in PET and both electron and hole traps in PEN. Their trap energies were 0.1 to 0.2 eV. (auth.)

  1. Analysis of the beam induced heat loads on the LHC arc beam screens during Run 2

    CERN Document Server

    Iadarola, Giovanni; Dijkstal, Philipp; Mether, Lotta; CERN. Geneva. ATS Department

    2017-01-01

    During Run 2 the Large Hadron Collider (LHC) has been routinely operated with 25 ns bunch spacing. In these conditions large heat loads have been measured on the beam screens of the superconducting magnets, together with other observations indicating that an electron cloud develops in the beam chambers. The analysis of these heat loads has revealed several interesting features allowing to pinpoint peculiar characteristics of the observed beam-induced heating. This document describes the main findings of this analysis including the evolution taking place during the run, the observed dependence on the beam conditions and the results from special tests and dedicated instrumentation. The differences observed in the behavior of the eight LHC arcs are also discussed.

  2. Disruption effects on the beam size measurement

    Energy Technology Data Exchange (ETDEWEB)

    Raimondi, P.; Decker, F.J.; Chen, P.

    1995-06-01

    At the SLC Final Focus with higher currents and smaller beam sizes, the disruption parameter D{sub y} is close to one and so the pinch effect should produce a luminosity enhancement. Since a flat beam-beam function is fit to deflection scan data to measure the beam size, disruption can affect the measurement. Here the authors discuss the quantitative effects of disruption for typical SLC beam parameters. With 3.5 10{sup 10} particles per pulse, bunch length of 0.8 mm and beam sizes of 2.1 {mu}m horizontally and 0.55 {mu}m vertically, the measured vertical size can be as much as 25% bigger than the real one. Furthermore during the collision the spot size actually decrease, producing an enhancement factor H{sub D} of about 1.25. This would yield to a true luminosity which is 1.6 times that which is estimated from the beam-beam deflection fit.

  3. Parallel electron-beam-induced deposition using a multi-beam scanning electron microscope

    NARCIS (Netherlands)

    Post, P.C.; Mohammadi-Gheidari, A.; Hagen, C.W.; Kruit, P.

    2011-01-01

    Lithography techniques based on electron-beam-induced processes are inherently slow compared to light lithography techniques. The authors demonstrate here that the throughput can be enhanced by a factor of 196 by using a scanning electron microscope equipped with a multibeam electron source. Using

  4. On compensating tune spread induced by space charge in bunched beams

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko V. N.; Wang, G.

    2014-05-09

    Space charge effects play significant role in modern-day accelerators. These effects frequently constrain attainable beam parameters in an accelerator, or, in an accelerator chain. They also could limit the luminosity of hadron colliders operating either at low energies or with a sub-TeV high brightness hadron beams. The latter is applied for strongly cooled proton and ion beams in eRHIC – the proposed future electron-ion collider at Brookhaven National Laboratory. A number of schemes for compensating space charge effects in a coasting (e.g. continuous) hadron beam were proposed and some of them had been tested. Using a proper transverse profile of the electron beam (or plasma column) for a coasting beam would compensate both the tune shift and the tune spread in the hadron beam. But all of these methods do not address the issue of tune spread compensation of a bunched hadron beam, e.g. the tune shift dependence on the longitudinal position inside the bunch. In this paper we propose and evaluate a novel idea of using a co-propagating electron bunch with miss-matched longitudinal velocity to compensate the space charge induced tune-shift and tune spread. We present a number of practical examples of such system.

  5. Beam energy spread in FERMI(at)elettra gun and linac induced by intrabeam scattering

    International Nuclear Information System (INIS)

    Zholents, Alexander A; Zholents, Alexander A; Zolotorev, Max S.; Penco, Giuseppe

    2008-01-01

    Intrabeam scattering (IBS) of electrons in the pre-cathode area in the electron guns know in the literature as Boersh effect is responsible for a growth of the electron beam energy spread there. Albeit most visible within the electron gun where the electron beam density is large and the energy spread is small, the IBS acts all along the entire electron beam pass through the Linac. In this report we calculate the energy spread induced by IBS in the FERMI(at)elettra electron gun

  6. Electron Beam Induced Functionalization of Fluoropolymers

    International Nuclear Information System (INIS)

    Lappan, U.

    2006-01-01

    Ionizing radiation affects the properties of polymers by chain scission and cross-linking reactions. One process will usually predominate, depending on the chemical structure of the polymer and the irradiation conditions such as temperature and atmosphere. Poly(tetrafluoroethylene) (PTFE) and the perfluorinated copolymers poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) and poly(tetrafluoroethylene-co-perfluoropropylvinyl ether) (PFA) undergo predominantly chain scission, if the irradiation is performed at room temperature. This shortcoming is exploited by converting PTFE into low molecular weight micropowders. The irradiation of PTFE in the presence of air results in micropowders functionalized with oxygen-containing groups. The concentration of end groups was investigated by FTIR and 19F solid-state NMR. The data were used to calculate number-average molecular weights. It was demonstrated that PTFE can be cross-linked by irradiation above its crystalline melting temperature in an oxygen-free atmosphere. Evidence for cross-links in PTFE was derived directly from structural information using 19 F solid-state NMR. FEP is understood to undergo cross-linking by irradiation above the glass transition temperature. It was found that also PFA can be branched and cross-linked by irradiation under special conditions. Radiation-induced grafting of styrene into fluoropolymer films and subsequent sulfonation offers an attractive way to prepare proton exchange membranes. Recently, radiation-induced grafting into cross-linked PTFE was reported. Modified FEP, PFA and ETFE films have been used as base material in this study. The modified films have been prepared by irradiation in nitrogen atmosphere at different temperatures up to temperatures above the melting temperature of the fluoropolymer

  7. Predictive Model of Electron Beam Induced Flashblindness.

    Science.gov (United States)

    1985-03-01

    65-71 (19514). 19. Chism , G. T., and J. H. Hill. Flashblindness: The effects of preflash adaptation and pupil size. Aerospace Med 38:395-399 (1967). 20... Chism , G. T. Intraocular effects on flashblindness: II. Parafoveal Re- covery. Aerospace Med 42:31-35 (1971). * 21. Wulfeck, J. W., A. Weisz, and M

  8. Impact of beam-beam effects on precision luminosity measurements at the ILC

    CERN Document Server

    Rimbault, C; Mönig, K; Schulte, D

    2007-01-01

    In this paper, the impact of beam-beam effects on the precision luminosity measurement at the International Linear Collider is investigated quantitatively for the first time. GUINEA-PIG, a beam-beam interaction simulation tool, is adapted to treat the space charge effects affecting the Bhabha events used in this measurement. The biases due to the resulting changes in kinematics are evaluated for different center-of-mass energies and beam parameters.

  9. Limits for Beam Induced Damage: Reckless or too Cautious?

    CERN Document Server

    Bertarelli, A; Carra, F; Cerutti, F; Dallocchio, A; Mariani, N; Peroni, L; Scapin, M

    2011-01-01

    Accidental events implying direct beam impacts on collimators are of the utmost importance as they may lead to serious limitations of the overall LHC Performance. In order to assess damage threshold of components impacted by high energy density beams, entailing changes of phase and extreme pressures, state-of-the-art numerical simulation methods are required. In this paper, a review of the different dynamic response regimes induced by particle beams is given along with an indication of the most suited tools to treat each regime. Particular attention is paid to the most critical case, that of shock waves, for which standard Finite Element codes are totally unfit. A novel category of numerical tools, named Hydrocodes, has been adapted and used to analyse the consequences of an asynchronous beam abort on Phase 1 Tertiary Collimators (TCT). A number of simulations has been carried out with varying beam energy, number of bunches and bunch sizes allowing to identify different damage levels for the TCT up to catastr...

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

    CERN Document Server

    Veselsky, Martin

    2012-01-01

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

  11. Atomistic modeling of ion beam induced amorphization in silicon

    International Nuclear Information System (INIS)

    Pelaz, Lourdes; Marques, Luis A.; Lopez, Pedro; Santos, Ivan; Aboy, Maria; Barbolla, Juan

    2005-01-01

    Ion beam induced amorphization in Si has attracted significant interest since the beginning of the use of ion implantation for the fabrication of Si devices. Nowadays, a renewed interest in the modeling of amorphization mechanisms at atomic level has arisen due to the use of preamorphizing implants and high dopant implantation doses for the fabrication of nanometric-scale Si devices. In this work, we briefly describe the existing phenomenological and defect-based amorphization models. We focus on the atomistic model we have developed to describe ion beam induced amorphization in Si. In our model, the building block for the amorphous phase is the bond defect or IV pair, whose stability increases with the number of surrounding IV pairs. This feature explains the regrowth behavior of different damage topologies and the kinetics of the crystalline to amorphous transition. The model provides excellent quantitative agreement with experimental results

  12. Radioprotective efficacy of bisarylidene cyclopentanone on electron beam radiation induced oxidative stress in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Darshan Raj, C.G.; Sarojini, B.K.; Musthafa Khaleel, V.; Ramesh, S.R.; Ramakrishna, M.K.; Narayana, B.; Sanjeev, Ganesh

    2010-01-01

    Present study was carried out for evaluating the radioprotective effect of bischalcone (2E, 5E) - 2,5-bis (3-methoxy-4-hydroxy-benzylidene) cyclopentanone (curcumin analog (CA)), on electron beam radiation induced oxidative stress in Drosophila melanogaster adults. The oxidative stress markers and antioxidants included superoxide dismutase (SOD) and catalase (CAT). The oxidative stress was induced at 1.5 Gy. (author)

  13. Single beam collective effects in FCC-ee due to beam coupling impedance

    CERN Document Server

    Belli, Eleonora; Persichelli, Serena; Zobov, Mikhail

    2016-01-01

    The Future Circular Collider study, hosted by CERN to design post-LHC particle accelerator options in a worldwide context, is focused on proton-proton high-energy and electron-positron high-luminosity frontier machines. This new accelerator complex represents a great challenge under several aspects, which involve R&D on beam dynamics and new technologies. One very critical point in this context is represented by collective effects, generated by the interaction of the beam with self-induced electromagnetic fields, called wake fields, which could produce beam instabilities, thus reducing the machines performance and limiting the maximum stored current. It is therefore very important to be able to predict these effects and to study in detail potential solutions to counteract them. In this paper the resistive wall and some other important geometrical sources of impedance for the FCC electron-positron accelerator are identified and evaluated, and their impact on the beam dynamics, which in some cases could lea...

  14. Single beam collective effects in FCC-ee due to beam coupling impedance

    CERN Document Server

    Belli, Eleonora

    2016-01-01

    The Future Circular Collider study, hosted by CERN to design post-LHC particle accelerator options in a worldwide context, is focused on proton-proton high-energy and electron-positron high-luminosity frontier machines. This new accelerator complex represents a great challenge under several aspects, which involve R&D on beam dynamics and new technologies. One very critical point in this context is represented by collective effects, generated by the interaction of the beam with self-induced electromagnetic fields, called wake fields, which could produce beam instabilities, thus reducing the machines performance and limiting the maximum stored current. It is therefore very important to be able to predict these effects and to study in detail potential solutions to counteract them. In this paper the resistive wall and some other important geometrical sources of impedance for the FCC electron-positron accelera- tor are identified and evaluated, and their impact on the beam dynamics, which in some cases could l...

  15. Analysis of radiation pressure force exerted on a biological cell induced by high-order Bessel beams using Debye series

    International Nuclear Information System (INIS)

    Li, Renxian; Ren, Kuan Fang; Han, Xiang'e; Wu, Zhensen; Guo, Lixin; Gong, Shuxi

    2013-01-01

    Debye series expansion (DSE) is employed to the analysis of radiation pressure force (RPF) exerted on biological cells induced by high-order Bessel beams (BB). The beam shape coefficients (BSCs) for high-order Bessel beams are calculated using analytical expressions obtained by the integral localized approximation (ILA). Different types of cells, including a real Chinese Hamster Ovary (CHO) cell and a lymphocyte which are respectively modeled by a coated and five-layered sphere, are considered. The RPF induced by high-order Bessel beams is compared with that by Gaussian beams and zeroth-order Bessel beams, and the effect of different scattering processes on RPF is studied. Numerical calculations show that high-order Bessel beams with zero central intensity can also transversely trap particle in the beam center, and some scattering processes can provide longitudinal pulling force. -- Highlights: ► BSCs for high-order Bessel beam (HOBB) is derived using ILA. ► DSE is employed to study the RPF induced by HOBB exerted on multilayered cells. ► RPF is decided by radius relative to the interval of peaks in intensity profile. ► HOBB can also transversely trap high-index particle in the vicinity of beam axis. ► RPF for some scattering processes can longitudinally pull particles back

  16. Electron beam effects on gelatin polymer

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Shimazaki, Kleber; Souza, Clecia de M.; Moura, Esperidiana A.B.; Mastro, Nelida L. del; Colombo, Maria A.

    2009-01-01

    The main field of electron-beam radiation processing applications is the modification of polymeric material. Polymer development includes new pathways to produce natural polymers with better mechanical and barrier properties and thermal stability. The aim of this paper was to investigate the behavior of a gelatin/acrylamide polymer treated by electron-beam radiation. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen, a fibrous insoluble protein, which is widely found in nature as the major constituent of skin, bones and connective tissue. Hydrolyzed collagen is composed of a unique sequence of amino acids, characterized particularly by the high content of glycine, proline and hydroxyproline. Among biomaterials, gelatin is an interesting material because is a partially crystalline polymer and has a relatively low melting point. Samples of gelatin together with glycerin as plasticizer and acrylamide as copolymer were irradiated with doses of 10 kGy and 40 kGy, using an electron beam accelerator, dose rate 22.41kGy/s, at room temperature in presence of air. After irradiation, some preliminary analyses were done like viscometry, texture analyses and colorimetry. The results of the diverse tests showed changes that can be ascribed to radiation-induced crosslinking. The electron-beam processed acrylamide-gelatin polymer using glycerin as plasticizer must be first extensively characterized before to be used for general applications. (author)

  17. Electron beam effects on gelatin polymer

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Shimazaki, Kleber; Souza, Clecia de M.; Moura, Esperidiana A.B.; Mastro, Nelida L. del, E-mail: patyoko@yahoo.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Colombo, Maria A., E-mail: mascolombo@yahoo.com.b [Faculdade de Tecnologia da Zona Leste, Sao Paulo, SP (Brazil)

    2009-07-01

    The main field of electron-beam radiation processing applications is the modification of polymeric material. Polymer development includes new pathways to produce natural polymers with better mechanical and barrier properties and thermal stability. The aim of this paper was to investigate the behavior of a gelatin/acrylamide polymer treated by electron-beam radiation. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen, a fibrous insoluble protein, which is widely found in nature as the major constituent of skin, bones and connective tissue. Hydrolyzed collagen is composed of a unique sequence of amino acids, characterized particularly by the high content of glycine, proline and hydroxyproline. Among biomaterials, gelatin is an interesting material because is a partially crystalline polymer and has a relatively low melting point. Samples of gelatin together with glycerin as plasticizer and acrylamide as copolymer were irradiated with doses of 10 kGy and 40 kGy, using an electron beam accelerator, dose rate 22.41kGy/s, at room temperature in presence of air. After irradiation, some preliminary analyses were done like viscometry, texture analyses and colorimetry. The results of the diverse tests showed changes that can be ascribed to radiation-induced crosslinking. The electron-beam processed acrylamide-gelatin polymer using glycerin as plasticizer must be first extensively characterized before to be used for general applications. (author)

  18. Turbulence-induced persistence in laser beam wandering.

    Science.gov (United States)

    Zunino, Luciano; Gulich, Damián; Funes, Gustavo; Pérez, Darío G

    2015-07-01

    We have experimentally confirmed the presence of long-memory correlations in the wandering of a thin Gaussian laser beam over a screen after propagating through a turbulent medium. A laboratory-controlled experiment was conducted in which coordinate fluctuations of the laser beam were recorded at a sufficiently high sampling rate for a wide range of turbulent conditions. Horizontal and vertical displacements of the laser beam centroid were subsequently analyzed by implementing detrended fluctuation analysis. This is a very well-known and widely used methodology to unveil memory effects from time series. Results obtained from this experimental analysis allow us to confirm that both coordinates behave as highly persistent signals for strong turbulent intensities. This finding is relevant for a better comprehension and modeling of the turbulence effects in free-space optical communication systems and other applications related to propagation of optical signals in the atmosphere.

  19. Compositional changes in industrial hemp biomass (Cannabis sativa L.) induced by electron beam irradiation Pretreatment

    International Nuclear Information System (INIS)

    Sung, Yong Joo; Shin, Soo-Jeong

    2011-01-01

    The effects of electron beam irradiation on chemical decomposition of industrial hemp biomass were evaluated at doses of 150, 300, and 450 kGy. The quantity of decomposed components was indirectly estimated by measuring changes in alkaline extraction. The more severe degradation of structural components induced by higher irradiation doses resulted in larger amounts of alkaline extract. Carbohydrate compositional analysis using 1 H-NMR spectroscopy was applied to quantitatively investigate changes in the polysaccharides of the industrial hemp. The xylose peak intensity in the NMR spectra decreased with increasing electron irradiation dose, indicating that xylan was more sensitive to electron beam irradiation than cellulose. -- Highlights: → The more severe degradation of structural components induced by higher irradiation. → Carbohydrate analysis was applied to quantitatively investigate changes in the industrial hemp. → Xylan was more sensitive to electron beam irradiation than cellulose.

  20. Induced focusing and conversion of a Gaussian beam into an elliptic ...

    Indian Academy of Sciences (India)

    Among several important findings, the finding that a very week probe beam can be guided and focused when power of both beams are well below their individual threshold for self-focusing, is a noteworthy one. It has been found that induced focusing is not possible for laser beams of any wavelength and beam radius.

  1. Beam induced heat loads on the beam-screens of the twin-bore magnets in the IRs of the HL-LHC

    CERN Document Server

    Iadarola, Giovanni; Rumolo, Giovanni

    2016-01-01

    The expected heat load induced on the beam screens has been evaluated for all the twin-bore magnets in the Insertion Regions (IRs) of the HL-LHC. The contribution from the impedance of the beam screen has been evaluated taking into account the presence of a longitudinal weld in the beam screen and the impact of the temperature and of the magnetic field on the resistivity of the surface. The contribution coming from electron cloud effects has been evaluated for different values of the Secondary Electron Yield of the surface based PyECLOUD build-up simulations.

  2. Electron-beam induced current characterization of back-surface field solar cells using a chopped scanning electron microscope beam

    Science.gov (United States)

    Luke, K. L.; Cheng, L.-J.

    1984-01-01

    A chopped electron beam induced current (EBIC) technique for the chacterization of back-surface field (BSF) solar cells is presented. It is shown that the effective recombination velocity of the low-high junction forming the back-surface field of BSF cells, in addition to the diffusion length and the surface recombination velocity of the surface perpendicular to both the p-n and low-high junctions, can be determined from the data provided by a single EBIC scan. The method for doing so is described and illustrated. Certain experimental considerations taken to enhance the quality of the EBIC data are also discussed.

  3. Ion beam induced luminescence on white inorganic pigments for paintings

    International Nuclear Information System (INIS)

    Quaranta, A.; Dran, J.C.; Salomon, J.; Tonezzer, M.; Scian, C.; Beck, L.; Carturan, S.; Maggioni, G.; Della Mea, G.

    2008-01-01

    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. Beam profile effects on NPB [neutral particle beam] performance

    International Nuclear Information System (INIS)

    LeClaire, R.J. Jr.

    1988-03-01

    A comparison of neutral particle beam brightness for various neutral beam profiles indicates that the widely used assumption of a Gaussian profile may be misleading for collisional neutralizers. An analysis of available experimental evidence shows that lower peaks and higher tails, compared to a Gaussian beam profile, are observed out of collisional neutralizers, which implies that peak brightness is over estimated, and for a given NPB platform-to-target range, the beam current (power), dwell time or some combination of such engagement parameters would have to be altered to maintain a fixed dose on target. Based on the present analysis, this factor is nominally about 2.4 but may actually be as low as 1.8 or as high as 8. This is an important consideration in estimating NPB constellation performance in SDI engagement contexts. 2 refs., 6 figs

  5. Ion-beam-induced amorphization and order-disorder transition in the murataite structure

    International Nuclear Information System (INIS)

    Lian Jie; Wang, L.M.; Ewing, Rodney C.; Yudintsev, Sergey V.; Stefanovsky, Sergey V.

    2005-01-01

    Murataite (A 3 B 6 C 2 O 22-x/2 ,F43m), a derivative of an anion-deficient fluorite structure, has been synthesized as different polytypes as a result of cation ordering. Ion-beam-induced amorphization has been investigated by 1-MeV Kr 2+ ion irradiation with in situ transmission electron microscopy. The critical amorphization dose was determined as a function of temperature and the degree of structural disordering. A lower critical amorphization temperature (∼860 K) was obtained for the disordered murataite as compared with that of the murataite superstructure (930 to 1060 K). An ion-beam-induced ordered murataite to a disordered fluorite transition occurred in the murataite superstructure, similar to that observed in the closely related pyrochlore structure-type, A 2 B 2 O 7 . The ion-beam-induced defect fluorite structure is more energetically stable in the murataite structure with a higher degree of structural disordering, as compared with the murataite superstructure. This suggests that the degree of intrinsic structural disorder has a significant effect on the energetics of structural disordering process; this affects the tendency toward the order-disorder structural transition for fluorite-related compounds and their response to ion-beam-induced amorphization

  6. Optical beam induced current microscopy at DC and radio frequency

    Science.gov (United States)

    Kao, Fu-Jen

    2004-06-01

    In this paper we introduce the concept and technique of optical beam induced current (OBIC) generation at radio frequencies. The method is combined with lateral raster scanning of a tightly focused spot so as to generate a mapping of high spatial resolution. We demonstrate experimentally that if a mode-locked laser is used to excite the sample then the frequency transfer function of the optically active device is readily obtained with at least 1 µm spatial resolution, in real time. In addition, with the help of an appropriate electronic arrangement, we demonstrate how to obtain pseudocolored OBIC images of the sample.

  7. Soft X-ray beam induced current technique

    Energy Technology Data Exchange (ETDEWEB)

    Watts, B; Ade, H [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Queen, D; Hellman, F [Department of Physics, University of California, Berkeley, CA 94720 (United States); Kilcoyne, A L D; Tyliszczak, T, E-mail: benjamin.watts@gmail.co [Advanced Light Source, Lawrence Berkeley Nat. Lab., Berkeley, CA 94720 (United States)

    2009-09-01

    Direct mapping of the charge transport efficiency of polymer solar cell devices using a soft X-ray beam induced current (SoXBIC) method is described. By fabricating a polymer solar cell on an x-ray transparent substrate, we demonstrate the ability to map polymer composition and nanoscale structure within an operating solar cell device and to simultaneously measure the local charge transport efficiency via the short-circuit current. A simple model is calculated and compared to experimental SoXBIC data of a PFB:F8BT bulk-heterojunction device in order to gain greater insight into the device operation and physics.

  8. Simulation of electron cloud effects to heavy ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Yaman, Fatih; Gjonaj, Erion; Weiland, Thomas [Technische Universitaet Darmstadt (Germany). Institut fuer Theorie Elektromagnetischer Felder

    2011-07-01

    Electron cloud (EC) driven instability can cause beam loss, emittance growth, trajectory change and wake fields. Mentioned crucial effects of EC motivated researchers to understand the EC build up mechanism and the effects of EC to the beam. This motivation also induced the progress of developing new simulation codes. EC simulations can roughly be divided into two classes such as, softwares whose goals are to simulate the build up of the EC during the passage of a bunch train and the codes which model the interaction of a bunch with an EC. The aim of this study is to simulate the effects of electron cloud (EC) on the dynamics of heavy ion beams which are used in heavy ion synchrotron (SIS-18) at GSI. To do this, a 3-D and self-consistent simulation program based on particle in cell (PIC) method is used. In the PIC cycle, accurate solution of the Maxwell equations is obtained by employing discontinuous Galerkin finite element method. As a model, we assumed a perfectly conducting beam pipe which was uniformly (or randomly) loaded with the electrons. Then as parallel with the realistic cases in SIS-18, a single bunch consisting of U{sup +73} ions was extracted which could propagate in this pipe. Due to EC-ion bunch interaction, electrons gained energy and their displacements were observed. Electric and magnetic field components and EC charge density were calculated, numerically.

  9. Multi-bunch energy spread induced by beam loading in standing wave structure

    International Nuclear Information System (INIS)

    Ferrario, M.; Tazzioli, F.

    1995-04-01

    The interaction of a relativistic beam with the modes of the TM 010 pass-band of a multicell cavity does not cause any problem: although all the modes are excited by the RF (radiofrequency) generator, resulting in different cell excitations during the cavity filling and the beam pulse, the net accelerating field exhibits negligible fluctuations from bunch to bunch. However, when the beam is not fully relativistic, this is no more true. The phase slippage occurring in the first cells, between the non relativistic beam and the lower pass-band modes, produces an effective enhancement of the shunt impedances, which is usually negligible for a relativistic beam in a well tuned cavity. Moreover, the voltage jumps (amplitude and phase) occurring at each bunch passage, as well as the beam detuning caused by the off-crest bunches, vary from cell to cell. These effects enhance dramatically the fluctuation of the accelerating voltage, with a dominant beating provided by the pass-band mode nearest to the pi-mode. The induced beam energy spread has been estimated by the help of two distinct codes, developed at Frascati (Italy) and (Saclay), with results in good agreement. While an interaction integral is computed at each bunch passage, the cavity refilling is calculated by solving coupled differential equations of the modes of the pass-band, driven by a generator linked to one end-cell. It is shown also that the intermode coupling arises from the external Q of the drive end-cell, and not from the wall losses. For illustration, the authors applied the method to the beam-loading problem in the SC capture cavity of the low charge injector of the TESLA test facility installed at DESY

  10. Analysis of charged particle induced reactions for beam monitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Surendra Babu, K. [IOP, Academia Sinica, Taipe, Taiwan (China); Lee, Young-Ouk [Nuclear Data Evaluation Laboratory, Korea Atomic Energy Research Institute (Korea, Republic of); Mukherjee, S., E-mail: smukherjee_msuphy@yahoo.co.in [Department of Physics, Faculty of Science, M.S. University of Baroda, Vadodara 390 002 (India)

    2012-07-15

    The reaction cross sections for different residual nuclides produced in the charged particle (p, d, {sup 3}He and {alpha}) induced reactions were calculated and compared with the existing experimental data which are important for beam monitoring and medical diagnostic applications. A detailed literature compilation and comparison were made on the available data sets for the above reactions. These calculations were carried out using the statistical model code TALYS up to 100 MeV, which contains Kalbach's latest systematic for the emission of complex particles and complex particle-induced reactions. All optical model calculations were performed by ECIS-03, which is built into TALYS. The level density, optical model potential parameters were adjusted to get the better description of experimental data. Various pre-equilibrium models were used in the present calculations with default parameters.

  11. Hollow Electron Beam Collimation for HL-LHC - Effects on the Beam Core

    Energy Technology Data Exchange (ETDEWEB)

    Fitterer, M. [Fermilab; Stancari, G. [Fermilab; Valishev, A. [Fermilab; Bruce, R. [CERN; Papotti, G [CERN; Redaelli, S. [CERN; Valentino, G. [Malta U.; Valentino, G. [CERN; Valuch, D. [CERN; Xu, C. [CERN

    2017-06-13

    Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the High Luminosity Large Hadron Collider (HL-LHC). To ensure the successful operation of the hollow beam collimator the unwanted effects on the beam core, which might arise from the operation with a pulsed electron beam, must be minimized. This paper gives a summary of the effect of hollow electron lenses on the beam core in terms of sources, provides estimates for HL-LHC and discusses the possible mitigation methods.

  12. Hollow Electron Beam Collimation for HL-LHC - Effects on the Beam Core

    CERN Document Server

    Fitterer, M; Valishev, A; Bruce, R; Papotti, G; Redaelli, S; Valentino, G; Valentino, G; Valuch, D; Xu, C

    2017-01-01

    Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the High Luminosity Large Hadron Collider (HL-LHC). To ensure the successful operation of the hollow beam collimator the unwanted effects on the beam core, which might arise from the operation with a pulsed electron beam, must be minimized. This paper gives a summary of the effect of hollow electron lenses on the beam core in terms of sources, provides estimates for HL-LHC and discusses the possible mitigation methods.

  13. Electron-beam-induced segregation in InGaN/GaN multiple-quantum wells

    International Nuclear Information System (INIS)

    O'Neill, J.P.; Ross, I.M.; Cullis, A.G.; Wang, T.; Parbrook, P.J.

    2003-01-01

    We report a study of the morphology and composition of In x Ga 1-x N/GaN multiple-quantum-well structures and their sensitivity to electron-beam damage. We have employed high-resolution transmission electron microscopy, energy dispersive x-ray analysis, and scanning transmission electron microscopy. Microstructural analysis was performed to investigate the dynamical effects of electron-beam irradiation on the relative indium distribution within the quantum wells. Exposure to relatively low incident beam illumination, corresponding to current densities at the specimen of ∼100 pA/cm 2 , was found to induce significant nanoclustering of indium within the multiple-quantum wells. These findings highlight the need for caution when reporting the presence of indium-rich clusters within InGaN/GaN multiple-quantum wells studied in the transmission electron microscope

  14. 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)

  15. Ion beam induced surface graphitization of CVD diamond for x-ray beam position monitor applications

    International Nuclear Information System (INIS)

    Liu, Chian; Shu, D.; Kuzay, T.M.; Wen, L.; Melendres, C.A.; Argonne National Lab., IL

    1996-01-01

    The Advanced Photon Source at ANL is a third-generation synchrotron facility that generates powerful x-ray beams on its undulator beamlines. It is important to know the position and angle of the x- ray beam during experiments. Due to very high heat flux levels, several patented x-ray beam position monitors (XBPM) exploiting chemical vapor deposition (CVD) diamond have been developed. These XBPMs have a thin layer of low-atomic-mass metallic coating so that photoemission from the x rays generate a minute but measurable current for position determination. Graphitization of the CVD diamond surface creates a very thin, intrinsic and conducting layer that can stand much higher temperatures and minimal x-ray transmission losses compared to the coated metallic layers. In this paper, a laboratory sputter ion source was used to transform selected surfaces of a CVD diamond substrate into graphite. The effect of 1-5 keV argon ion bombardment on CVD diamond surfaces at various target temperatures from 200 to 500 C was studied using Auger electron spectroscopy and in-situ electrical resistivity measurements. Graphitization after the ion bombardment has been confirmed and optimum conditions for graphitization studied. Raman spectroscopy was used to identify the overall diamond structure in the bulk of CVD diamond substrate after the ion bombardments. It was found that target temperature plays an important role in stability and electrical conductivity of the irradiated CVD diamonds

  16. Induced focusing and conversion of a Gaussian beam into an elliptic ...

    Indian Academy of Sciences (India)

    We have presented an investigation of the induced focusing in Kerr media of two laser beams, the pump beam and ... in nonlinear media has been confined to cylindrical Gaussian beams. In a few re- cent publications .... Inserting suitable chosen trial functions in the variational principle, we can obtain a reduced variational ...

  17. Effects of electron beam irradiation on tin dioxide gas sensors

    Indian Academy of Sciences (India)

    In this paper, the effects of electron beam irradiation on the gas sensing performance of tin dioxide thin films toward H2 are studied. The tin dioxide thin films were prepared by ultrasonic spray pyrolysis. The results show that the sensitivity increased after electron beam irradiation. The electron beam irradiation effects on tin ...

  18. Study on DNA Damage Induced by Neon Beam Irradiation in Saccharomyces Cerevisiae

    International Nuclear Information System (INIS)

    Lu Dong; Li Wenjian; Wu Xin; Wang Jufang; Ma Shuang; Liu Qingfang; He Jinyu; Jing Xigang; Ding Nan; Dai Zhongying; Zhou Jianping

    2010-01-01

    Yeast strain Saccharomyces cerevisiae was irradiated with different doses of 85 MeV/u 20 Ne 10+ to investigate DNA damage induced by heavy ion beam in eukaryotic microorganism. The survival rate, DNA double strand breaks (DSBs) and DNA polymorphic were tested after irradiation. The results showed that there were substantial differences in DNA between the control and irradiated samples. At the dose of 40 Gy, the yeast cell survival rate approached 50%, DNA double-strand breaks were barely detectable, and significant DNA polymorphism was observed. The alcohol dehydrogenase II gene was amplified and sequenced. It was observed that base changes in the mutant were mainly transversions of T→G and T→C. It can be concluded that heavy ion beam irradiation can lead to change in single gene and may be an effective way to induce mutation.

  19. Ion beam induced charge microscopy studies of power diodes

    International Nuclear Information System (INIS)

    Zmeck, M; Balk, L J; Osipowicz, T; Watt, F; Phang, J C H; Khambadkone, A M; Niedernostheide, F-J; Schulze, H-J

    2004-01-01

    Ion beam induced charge microscopy (IBIC microscopy) has been established recently as an analytical tool for the characterization of various types of semiconductor devices. In this paper the potential of IBIC microscopy for the analysis of deeply buried structures of high power devices under biases of more than 2 kV is discussed. Such data are useful in the design process of high power devices because excessive fields at device edge regions or within protection elements (e.g. field ring structures) can be avoided. Since charge collection efficiency within depleted pn junctions is typically 100% for IBIC analysis, the contrast due to E-field variations within the large depletion regions of high power devices is limited. Here we will introduce a new approach for enhancing this contrast by using the temporal information from the IBIC signals gained with a transient IBIC set-up. Simulations and experimental data will be compared to evaluate the suitability of the new approach. The device used here is a high voltage diode with a field ring structure which was analysed using a 2 MeV proton beam

  20. Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter

    Science.gov (United States)

    Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

    2017-03-01

    Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.

  1. Analysis of beam envelope by transverse space charge effect

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Shin`ichi [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-09-01

    It is important for high current accelerators to estimate the contribution of the space charge effect to keep the beam off its beak up. The application of an envelope equation is examined in previous report in which the beam is just coasting beam (non accelerating). The analysis of space charge effect is necessary for the comparison in coming accelerator test in PNC. In order to evaluate the beam behavior in high current, the beam dynamics and beam parameters which are input to the equation for the evaluation are developed and make it ready to estimate the beam transverse dynamics by the space charge. The estimate needs to have enough accuracy for advanced code calculation. After the preparation of the analytic expression of transverse motion, the non-linear differential equation of beam dynamics is solved by a numerical method on a personal computer. The beam envelope from the equation is estimated by means of the beam emittance, current and energy. The result from the analysis shows that the transverse beam broadening is scarecely small around the beam current value of PNC design. The contribution to the beam broadening of PNC linac comes from its beam emittance. The beam broadening in 100 MeV case is almost negligible in the view of transverse space charge effect. Therefore, the electron beam is stable up to 10 A order in PNC linac design. Of course, the problem for RF supply is out of consideration here. It is important to estimate other longitudinal effect such as beam bunch effect which is lasting unevaluated. (author)

  2. A laser beam quality definition based on induced temperature rise.

    Science.gov (United States)

    Miller, Harold C

    2012-12-17

    Laser beam quality metrics like M(2) can be used to describe the spot sizes and propagation behavior of a wide variety of non-ideal laser beams. However, for beams that have been diffracted by limiting apertures in the near-field, or those with unusual near-field profiles, the conventional metrics can lead to an inconsistent or incomplete description of far-field performance. This paper motivates an alternative laser beam quality definition that can be used with any beam. The approach uses a consideration of the intrinsic ability of a laser beam profile to heat a material. Comparisons are made with conventional beam quality metrics. An analysis on an asymmetric Gaussian beam is used to establish a connection with the invariant beam propagation ratio.

  3. Error-Induced Beam Degradation in Fermilab's Accelerators

    International Nuclear Information System (INIS)

    Yoon, Phil S.

    2007-01-01

    In Part I, three independent models of Fermilab's Booster synchrotron are presented. All three models are constructed to investigate and explore the effects of unavoidable machine errors on a proton beam under the influence of space-charge effects. The first is a stochastic noise model. Electric current fluctuations arising from power supplies are ubiquitous and unavoidable and are a source of instabilities in accelerators of all types. A new noise module for generating the Ornstein-Uhlenbeck (O-U) stochastic noise is first created and incorporated into the existing Object-oriented Ring Beam Injection and Tracking (ORBIT-FNAL) package. After being convinced with a preliminary model that the noise, particularly non-white noise, does matter to beam quality, we proceeded to measure directly current ripples and common-mode voltages from all four Gradient Magnet Power Supplies (GMPS). Then, the current signals are Fourier-analyzed. Based upon the power spectra of current signals, we tune up the Ornstein-Uhlnbeck noise model. As a result, we are able to closely match the frequency spectra between current measurements and the modeled O-U stochastic noise. The stochastic noise modeled upon measurements is applied to the Booster beam in the presence of the full space-charge effects. This noise model, accompanied by a suite of beam diagnostic calculations, manifests that the stochastic noise, impinging upon the beam and coupled to the space-charge effects, can substantially enhance the beam degradation process throughout the injection period. The second model is a magnet misalignment model. It is the first time to utilize the latest beamline survey data for building a magnet-by-magnet misalignment model. Given as-found survey fiducial coordinates, we calculate all types of magnet alignment errors (station error, pitch, yaw, roll, twists, etc.) are implemented in the model. We then follow up with statistical analysis to understand how each type of alignment errors are

  4. Effect of a spectrometer magnet on the beam-beam interaction

    International Nuclear Information System (INIS)

    Cornacchia, M.; Parzen, G.

    1981-01-01

    The presence of experimental apparatus in the interaction regions of an intersecting beam accelerator changes the configuration of the crossing beams. This changes the space-charge forces with respect to the standard, magnet-free crossing. The question is: what is the maximum allowable perturbation caused by the spectrometer magnet that can be tolerated from the point of view of the beam dynamics. This paper is limited to the perturbations that the curved trajectories cause the beam-beam space charge nonlinearities. The question has arisen of how one defines the strength of the perturbation. The only solution is to compute the strength of the most important nonlinear resources. In what follows, the computational method used in calculating these resonances is described, and compared with those induced by random orbit errors

  5. Effect of a spectrometer magnet on the beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Cornacchia, M; Parzen, G

    1981-01-01

    The presence of experimental apparatus in the interaction regions of an intersecting beam accelerator changes the configuration of the crossing beams. This changes the space-charge forces with respect to the standard, magnet-free crossing. The question is: what is the maximum allowable perturbation caused by the spectrometer magnet that can be tolerated from the point of view of the beam dynamics. This paper is limited to the perturbations that the curved trajectories cause the beam-beam space charge nonlinearities. The question has arisen of how one defines the strength of the perturbation. The only solution is to compute the strength of the most important nonlinear resources. In what follows, the computational method used in calculating these resonances is described, and compared with those induced by random orbit errors.

  6. Report on single beam stability - coherent effects

    International Nuclear Information System (INIS)

    Brouzet, E.; Gareyte, J.; Hofmann, A.; Laclare, J.C.; Leleux, G.; Miles, J.; Schindl, K.H.

    1980-01-01

    Group 1A was concerned with single beam stability, coherent effects. Theory is available. Most of the material for this work was drawn from F.J. Sacherer theory which has been left in reasonably good shape in the sense that given any coupling impedance, its effect on the beam can be estimated. The EBI computer program was extensively used in this respect. We still lack thorough knowledge of the SPS coupling impedance. Accordingly our results rest on a model. This model should be too unrealistic since it originates from various data of the SPS and other machines. Nevertheless any complementary information about the SPS impedance would be welcome. Broad-band impedance and parasitic effects on transverse and longitudinal motions will be reviewed. We shall mainly focus on the 270 GeV case with six equidistant bunches and 10 11 particles per bunch. For other schemes results can be obtained in a similar fashion. Some relevant figures will be given for the situation at injection. (orig.)

  7. Numerical Simulation of Beam-Beam Effects in the Proposed Electron-Ion Colider at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Balsa Terzic, Yuhong Zhang

    2010-05-01

    One key limiting factor to a collider luminosity is beam-beam interactions which usually can cause serious emittance growth of colliding beams and fast reduction of luminosity. Such nonlinear collective beam effect can be a very serious design challenge when the machine parameters are pushed into a new regime. In this paper, we present simulation studies of the beam-beam effect for a medium energy ring-ring electron-ion collider based on CEBAF.

  8. Thermomechanical assessment of the effects of a jaw-beam angle during beam impact on Large Hadron Collider collimators

    Science.gov (United States)

    Cauchi, Marija; Assmann, R. W.; Bertarelli, A.; Carra, F.; Lari, L.; Rossi, A.; Mollicone, P.; Sammut, N.

    2015-02-01

    The correct functioning of a collimation system is crucial to safely and successfully operate high-energy particle accelerators, such as the Large Hadron Collider (LHC). However, the requirements to handle high-intensity beams can be demanding, and accident scenarios must be well studied in order to assess if the collimator design is robust against possible error scenarios. One of the catastrophic, though not very probable, accident scenarios identified within the LHC is an asynchronous beam dump. In this case, one (or more) of the 15 precharged kicker circuits fires out of time with the abort gap, spraying beam pulses onto LHC machine elements before the machine protection system can fire the remaining kicker circuits and bring the beam to the dump. If a proton bunch directly hits a collimator during such an event, severe beam-induced damage such as magnet quenches and other equipment damage might result, with consequent downtime for the machine. This study investigates a number of newly defined jaw error cases, which include angular misalignment errors of the collimator jaw. A numerical finite element method approach is presented in order to precisely evaluate the thermomechanical response of tertiary collimators to beam impact. We identify the most critical and interesting cases, and show that a tilt of the jaw can actually mitigate the effect of an asynchronous dump on the collimators. Relevant collimator damage limits are taken into account, with the aim to identify optimal operational conditions for the LHC.

  9. Thermomechanical assessment of the effects of a jaw-beam angle during beam impact on Large Hadron Collider collimators

    Directory of Open Access Journals (Sweden)

    Marija Cauchi

    2015-02-01

    Full Text Available The correct functioning of a collimation system is crucial to safely and successfully operate high-energy particle accelerators, such as the Large Hadron Collider (LHC. However, the requirements to handle high-intensity beams can be demanding, and accident scenarios must be well studied in order to assess if the collimator design is robust against possible error scenarios. One of the catastrophic, though not very probable, accident scenarios identified within the LHC is an asynchronous beam dump. In this case, one (or more of the 15 precharged kicker circuits fires out of time with the abort gap, spraying beam pulses onto LHC machine elements before the machine protection system can fire the remaining kicker circuits and bring the beam to the dump. If a proton bunch directly hits a collimator during such an event, severe beam-induced damage such as magnet quenches and other equipment damage might result, with consequent downtime for the machine. This study investigates a number of newly defined jaw error cases, which include angular misalignment errors of the collimator jaw. A numerical finite element method approach is presented in order to precisely evaluate the thermomechanical response of tertiary collimators to beam impact. We identify the most critical and interesting cases, and show that a tilt of the jaw can actually mitigate the effect of an asynchronous dump on the collimators. Relevant collimator damage limits are taken into account, with the aim to identify optimal operational conditions for the LHC.

  10. Improved single particle potential for transport model simulations of nuclear reactions induced by rare isotope beams

    International Nuclear Information System (INIS)

    Xu Chang; Li Baoan

    2010-01-01

    Taking into account more accurately the isospin dependence of nucleon-nucleon interactions in the in-medium many-body force term of the Gogny effective interaction, new expressions for the single-nucleon potential and the symmetry energy are derived. Effects of both the spin (isospin) and the density dependence of nuclear effective interactions on the symmetry potential and the symmetry energy are examined. It is shown that they both play a crucial role in determining the symmetry potential and the symmetry energy at suprasaturation densities. The improved single-nucleon potential will be useful for more accurate simulation of nuclear reactions induced by rare-isotope beams within transport models.

  11. Reactions induced by 11Be beam at Rex-Isolde

    Directory of Open Access Journals (Sweden)

    Jeppesen H.

    2011-10-01

    Full Text Available The collision induced by the three Beryllium isotopes, 9,10,11Be, on a 64Zn target were investigated at Ec.m. ≈ 1.4 the Coulomb barrier. The experiments with the radioactive 10,11Be beams were performed at the Rex-Isolde facility at CERN. In the case of 9,10Be, elastic scattering angular distributions were measured whereas, in the 11Be case, the quasielastic scattering angular distribution was obtained. A strong damping of the quasielastic cross-section was observed in the 11Be case, in the angular range around the Coulomb-nuclear interference peak. In this latter case a large total-reaction cross-section is found. Such a cross-section is more than a factor of two larger than the ones extracted in the reactions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the 11Be case could be attributed to transfer and/or break-up events.

  12. Beam-induced temperature changes in HVEM irradiations

    International Nuclear Information System (INIS)

    Garner, F.A.; Thomas, L.E.; Gelles, D.S.

    1975-01-01

    The peak value of the temperature distribution induced by energy loss of 1.0 MeV electrons in traversing a typical HVEM irradiation specimen can be very substantial. The origin and various features of this distribution were analyzed for a variety of specimen geometries. The major parametric dependencies are shown to be relatively independent of specimen geometry, however, and allow the definition of a scaling relationship that can be employed to predict temperature rises in materials that cannot be measured directly. The use of this scaling relationship requires that the experimenter minimize perturbations of the heat flow due to proximity of the central hole in the specimen. An experimental method of determining directly the magnitude and distribution of beam-induced temperature profiles was developed which utilizes the order-disorder transformation in Fe 3 Al and Cu 3 Au. Scaling of experimentally determined temperature changes leads to more realistic estimates of the total temperature rise than are currently available in various literature tabulations. The factors which determine the optimum selection of irradiation parameters for a given experiment are also discussed

  13. Electron cloud effects in hadron beams

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Fedor; Boine-Frankenheim, Oliver; Weiland, Thomas [TU-Darmstadt, Institut fuer Theorie Elektromagnetischer Felder,Schlossgartenstr. 8 64289 Darmstadt (Germany)

    2013-07-01

    Accelerators operating with intense positively charged beams can suffer from the electron cloud phenomenon. For example, it is the intensity limiting factor in CERN LHC and SPS. In past decades a lot of progress in understanding the electron cloud effects was made worldwide. Methods to suppress or weaken the electron cloud phenomenon were proposed. Theories governing the bunch stability in presence of the electron cloud were developed. Recently the theory was introduced to describe the bunch energy loss due to the electron cloud. However, most of the publications concern the single bunch electron cloud effects. In reality bunches are packed into trains. A disturbance of the cloud caused by the bunch in the beginning of the train affects the subsequent bunches. We present a further investigation of single-bunch electron cloud effects and planned activities to study the phenomenon in case of multiple bunches.

  14. Progress on Beam-Plasma Effect Simulations in Muon Ionization Cooling Lattices

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James [IIT, Chicago; Snopok, Pavel [Fermilab

    2017-05-01

    New computational tools are essential for accurate modeling and simulation of the next generation of muon-based accelerators. One of the crucial physics processes specific to muon accelerators that has not yet been simulated in detail is beam-induced plasma effect in liquid, solid, and gaseous absorbers. We report here on the progress of developing the required simulation tools and applying them to study the properties of plasma and its effects on the beam in muon ionization cooling channels.

  15. Electron and ion beam degradation effects in AES analysis of silicon nitride thin films

    International Nuclear Information System (INIS)

    Fransen, F.; Vanden Berghe, R.; Vlaeminck, R.; Hinoul, M.; Remmerie, J.; Maes, H.E.

    1985-01-01

    Silicon nitride films are currently investigated by AES combined with ion profiling techniques for their stoichiometry and oxygen content. During this analysis, ion beam and primary electron effects were observed. The effect of argon ion bombardment is the preferential sputtering of nitrogen, forming 'covalent' silicon at the surface layer (AES peak at 91 eV). The electron beam irradiation results in a decrease of the covalent silicon peak, either by an electron beam annealing effect in the bulk of the silicon nitride film, or by an ionization enhanced surface diffusion process of the silicon (electromigration). By the electron beam annealing, nitrogen species are liberated in the bulk of the silicon nitride film and migrate towards the surface where they react with the covalent silicon. The ionization enhanced diffusion originates from local charging of the surface, induced by the electron beam. (author)

  16. Trapping induced nonlinear behavior of backward stimulated Raman scattering in multi-speckled laser beams

    International Nuclear Information System (INIS)

    Yin, L.; Albright, B. J.; Rose, H. A.; Bowers, K. J.; Bergen, B.; Montgomery, D. S.; Kline, J. L.; Kirkwood, R. K.; Hinkel, D. E.; Langdon, A. B.; Michel, P.

    2012-01-01

    In inertial confinement fusion experiments, stimulated Raman scattering (SRS) occurs when electron density fluctuations are amplified resonantly by the incident laser beams and scattered light. These beams comprise several thousands of individual laser speckles. We have found in single-speckle studies that electron trapping lowers the threshold intensity for SRS onset to a value below that from linear theory and enhances scattering. The trapping-induced plasma-wave frequency shift leads to wave-front bowing and filamentation processes that saturate SRS and limit scattering within a speckle. With large-scale simulations, we have now examined how laser speckles interact with one another through three-dimensional (3D) particle-in-cell (PIC) simulations of two interacting speckles and 2D PIC simulations of ensembles of laser speckles (hundreds of speckles). Our work shows that kinetic trapping physics also governs the onset and saturation of SRS in ensembles of speckles. Speckles interact in a manner that is nonlinear and nonlocal: An intense speckle can destabilize its neighbors through transport of hot electrons and SRS waves, resulting in enhanced emission of particles and waves that, in turn, act upon the original speckle. In this manner, speckles below threshold when in isolation can be above the threshold in multi-speckled beams under conditions for laser-driven fusion experiments at the National Ignition Facility (NIF) and ensembles of speckles are thus found to collectively lower the SRS onset threshold. Simulations of the hohlraum interior where laser beams overlap show that multi-speckled laser beams at low average intensity (a few times 10 14 W/cm 2 ) have correspondingly lower thresholds for enhanced SRS and that the sub-ps bursts of SRS saturate through trapping induced nonlinearities. Because of electron trapping effects, SRS reflectivity grows slowly with average laser intensity. While SRS reflectivity saturates under NIF conditions, SRS hot electron

  17. TRANSIENT BEAM LOADING EFFECTS IN RF SYSTEMS IN JLEIC

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haipeng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Guo, Jiquan [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Rimmer, Robert A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wang, Shaoheng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    The pulsed electron bunch trains generated from the Continuous Electron Beam Accelerator Facility (CEBAF) linac to inject into the proposed Jefferson Lab Electron Ion Collider (JLEIC) e-ring will produce transient beam loading effects in the Superconducting Radio Frequency (SRF) systems that, if not mitigated, could cause unacceptably large beam energy deviation in the injection capture, or exceed the energy acceptance of CEBAF’s recirculating arcs. In the electron storage ring, the beam abort or ion clearing gaps or uneven bucket filling can cause large beam phase transients in the (S)RF cavity control systems and even beam loss due to Robinson instability. We have first analysed the beam stability criteria in steady state and estimated the transient effect in Feedforward and Feedback RF controls. Initial analytical models for these effects are shown for the design of the JLEIC e-ring from 3GeV to 12GeV.

  18. Structural Effects of Reinforced Concrete Beam Due to Corrosion

    Science.gov (United States)

    Noh, Hamidun Mohd; Idris, Nur'ain; Noor, Nurazuwa Md; Sarpin, Norliana; Zainal, Rozlin; Kasim, Narimah

    2018-03-01

    Corrosion of steel in reinforced concrete is one of the main issues among construction stakeholders. The main consequences of steel corrosion include loss of cross section of steel area, generation of expansive pressure which caused cracking of concrete, spalling and delaminating of the concrete cover. Thus, it reduces the bond strength between the steel reinforcing bar and concrete, and deteriorating the strength of the structure. The objective of this study is to investigate the structural effects of corrosion damage on the performance of reinforced concrete beam. A series of corroded reinforced concrete beam with a corrosion rate of 0%, 20% and 40% of rebar corrosion is used in parametric study to assess the influence of different level of corrosion rate to the structural performance. As a result, the used of interface element in the finite element modelling predicted the worst case of corrosion analysis since cracks is induced and generate at this surface. On the other hand, a positive linear relationship was sketched between the increase of expansive pressure and the corrosion rate. Meanwhile, the gradient of the graph is decreased with the increase of steel bar diameter. Furthermore, the analysis shows that there is a significant effect on the load bearing capacity of the structure where the higher corrosion rate generates a higher stress concentration at the mid span of the beam. This study could predict the residual strength of reinforced concrete beam under the corrosion using the finite element analysis. The experimental validation is needed on the next stage to investigate the quantitative relation between the corrosion rate and its influence on the mechanical properties.

  19. Structural Effects of Reinforced Concrete Beam Due to Corrosion

    Directory of Open Access Journals (Sweden)

    Mohd Noh Hamidun

    2018-01-01

    Full Text Available Corrosion of steel in reinforced concrete is one of the main issues among construction stakeholders. The main consequences of steel corrosion include loss of cross section of steel area, generation of expansive pressure which caused cracking of concrete, spalling and delaminating of the concrete cover. Thus, it reduces the bond strength between the steel reinforcing bar and concrete, and deteriorating the strength of the structure. The objective of this study is to investigate the structural effects of corrosion damage on the performance of reinforced concrete beam. A series of corroded reinforced concrete beam with a corrosion rate of 0%, 20% and 40% of rebar corrosion is used in parametric study to assess the influence of different level of corrosion rate to the structural performance. As a result, the used of interface element in the finite element modelling predicted the worst case of corrosion analysis since cracks is induced and generate at this surface. On the other hand, a positive linear relationship was sketched between the increase of expansive pressure and the corrosion rate. Meanwhile, the gradient of the graph is decreased with the increase of steel bar diameter. Furthermore, the analysis shows that there is a significant effect on the load bearing capacity of the structure where the higher corrosion rate generates a higher stress concentration at the mid span of the beam. This study could predict the residual strength of reinforced concrete beam under the corrosion using the finite element analysis. The experimental validation is needed on the next stage to investigate the quantitative relation between the corrosion rate and its influence on the mechanical properties.

  20. Effect of beam arrangement on oral cavity dose in external beam radiotherapy of nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Vincent W.C. [Department of Health Technology and Informatics, Hong Kong Polytechnic University, Kowloon, Hong Kong (Hong Kong); Yang Zhining; Zhang Wuzhe; Wu Lili [Cancer Hospital, Shantou University Medical College, Shantou (China); Lin Zhixiong, E-mail: zxlin5@yahoo.com [Cancer Hospital, Shantou University Medical College, Shantou (China)

    2012-07-01

    This study compared the oral cavity dose between the routine 7-beam intensity-modulated radiotherapy (IMRT) beam arrangement and 2 other 7-beam IMRT with the conventional radiotherapy beam arrangements in the treatment of nasopharyngeal carcinoma (NPC). Ten NPC patients treated by the 7-beam routine IMRT technique (IMRT-7R) between April 2009 and June 2009 were recruited. Using the same computed tomography data, target information, and dose constraints for all the contoured structures, 2 IMRT plans with alternative beam arrangements (IMRT-7M and IMRT-7P) by avoiding the anterior facial beam and 1 conventional radiotherapy plan (CONRT) were computed using the Pinnacle treatment planning system. Dose-volume histograms were generated for the planning target volumes (PTVs) and oral cavity from which the dose parameters and the conformity index of the PTV were recorded for dosimetric comparisons among the plans with different beam arrangements. The dose distributions to the PTVs were similar among the 3 IMRT beam arrangements, whereas the differences were significant between IMRT-7R and CONRT plans. For the oral cavity dose, the 3 IMRT beam arrangements did not show significant difference. Compared with IMRT-7R, CONRT plan showed a significantly lower mean dose, V30 and V-40, whereas the V-60 was significantly higher. The 2 suggested alternative beam arrangements did not significantly reduce the oral cavity dose. The impact of varying the beam angles in IMRT of NPC did not give noticeable effect on the target and oral cavity. Compared with IMRT, the 2-D conventional radiotherapy irradiated a greater high-dose volume in the oral cavity.

  1. Nano-ranged low-energy ion-beam-induced DNA transfer in biological cells

    International Nuclear Information System (INIS)

    Yu, L.D.; Wongkham, W.; Prakrajang, K.; Sangwijit, K.; Inthanon, K.; Thongkumkoon, P.; Wanichapichart, P.; Anuntalabhochai, S.

    2013-01-01

    Low-energy ion beams at a few tens of keV were demonstrated to be able to induce exogenous macromolecules to transfer into plant and bacterial cells. In the process, the ion beam with well controlled energy and fluence bombarded living cells to cause certain degree damage in the cell envelope in nanoscales to facilitate the macromolecules such as DNA to pass through the cell envelope and enter the cell. Consequently, the technique was applied for manipulating positive improvements in the biological species. This physical DNA transfer method was highly efficient and had less risk of side-effects compared with chemical and biological methods. For better understanding of mechanisms involved in the process, a systematic study on the mechanisms was carried out. Applications of the technique were also expanded from DNA transfer in plant and bacterial cells to DNA transfection in human cancer cells potentially for the stem cell therapy purpose. Low-energy nitrogen and argon ion beams that were applied in our experiments had ranges of 100 nm or less in the cell envelope membrane which was majorly composed of polymeric cellulose. The ion beam bombardment caused chain-scission dominant damage in the polymer and electrical property changes such as increase in the impedance in the envelope membrane. These nano-modifications of the cell envelope eventually enhanced the permeability of the envelope membrane to favor the DNA transfer. The paper reports details of our research in this direction.

  2. Vortex phase-induced changes of the statistical properties of a partially coherent radially polarized beam.

    Science.gov (United States)

    Guo, Lina; Chen, Yahong; Liu, Xianlong; Liu, Lin; Cai, Yangjian

    2016-06-27

    Partially coherent radially polarized (PCRP) beam was introduced and generated in recent years. In this paper, we investigate the statistical properties of a PCRP beam embedded with a vortex phase (i.e., PCRP vortex beam). We derive the analytical formula for the cross-spectral density matrix of a PCRP vortex beam propagating through a paraxial ABCD optical system and analyze the statistical properties of a PCRP vortex beam focused by a thin lens. It is found that the statistical properties of a PCRP vortex beam on propagation are much different from those of a PCRP beam. The vortex phase induces not only the rotation of the beam spot, but also the changes of the beam shape, the degree of polarization and the state of polarization. We also find that the vortex phase plays a role of resisting the coherence-induced degradation of the intensity distribution and the coherence-induced depolarization. Furthermore, we report experimental generation of a PCRP vortex beam for the first time. Our results will be useful for trapping and rotating particles, free-space optical communications and detection of phase object.

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  4. Effects of high repetition rate and beam size on hard tissue damage due to subpicosecond laser pulses

    International Nuclear Information System (INIS)

    Kim, Beop-Min; Feit, Michael D.; Rubenchik, Alexander M.; Joslin, Elizabeth J.; Eichler, Juergen; Stoller, Patrick C.; Da Silva, Luiz B.

    2000-01-01

    We report the effects of the repetition rate and the beam size on the threshold for ultrashort laser pulse induced damage in dentin. The observed results are explained as cumulative thermal effects. Our model is consistent with the experimental results and explains the dependence of the threshold on repetition rate, beam size, and exposure time. (c) 2000 American Institute of Physics

  5. Cylindrical shock waves and dynamic phenomena induced in solids by intense proton beams

    Science.gov (United States)

    Bertarelli, Alessandro; Carra, Federico; Dallocchio, Alessandro; Guinchard, Michael; Mariani, Nicola; Peroni, Lorenzo; Redaelli, Stefano; Scapin, Martina

    2013-06-01

    The accidental impact of hadron beams on matter can induce intense shockwaves along with complex dynamic phenomena (phase transitions, extended density changes, explosions and fragment projections). These events have been successfully modeled resorting to wave propagation codes; to produce accurate results, however, these programs require reliable material constitutive models that are often scarce and inaccurate. A complex and innovative experiment was carried out at CERN to benchmark existing material constitutive models and possibly derive new ones. The test setup, aimed at the characterization of six different materials impacted by 440 GeV intense proton pulses, allowed to generate cylindrical shockwaves on material specimens and to observe the effects induced by their propagation. This method, a combination between numerical simulations and an experimental technique, permitting to tune the intensity, location and timing of the beam-deposited energy, may allow to study the effects induced by internal, quasi-instantaneous loadings in domains well beyond particle physics (accidents in nuclear facilities, internal explosions, high pressure blasts etc.), particularly when relatively little explored cylindrical shockwaves are generated. The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579.

  6. A Study of the Effect of Beam-Beam Interactions on CESR Optics

    CERN Document Server

    Crittenden, James Arthur; Rubin, David

    2005-01-01

    The CESR storage ring facility has begun operation in an energy region which allows high-statistics investigation of charm-quark bound states. Experience during the first year has shown that the effects of parasitic crossings in the pretzel orbits present an important factor in injection efficiency, in the beam lifetime and stored current limits. We compare the results of beam dynamics and tracking calculations which quantify the effects of these parasitic crossings on optics and dynamic aperture for the injected and stored trajectories to observations of beam behavior.

  7. Studies of space charge effects on operating electron beam ion trap at low electron beam energy

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xuelong; Fei, Zejie; Xiao, Jun; Lu, Di; Hutton, Roger [The Key Lab of Applied Ion Beam Physics, Ministry of Education (China); Shanghai EBIT Laboratory, Modern Physics Institute, Fudan University, Shanghai (China); Zou, Yaming, E-mail: zouym@fudan.edu.cn [The Key Lab of Applied Ion Beam Physics, Ministry of Education (China); Shanghai EBIT Laboratory, Modern Physics Institute, Fudan University, Shanghai (China)

    2013-08-21

    An electron beam ion trap (EBIT) is a powerful machine for disentangling studies of atomic processes in plasmas. To assist studies on edge plasma spectroscopic diagnostics, a very low energy EBIT, SH-PermEBIT, has been set up at the Shanghai EBIT lab. Large amounts of simulation works were done to study the factors which hinder the EBIT from operation at very low electron beam energies. Under the guide line of the simulation results, we finally managed to successfully reach 60 eV for the lower end of the electron beam energy with a beam transmission above 57%. In this presentation, simulation studies of the space charge effect, which is one of the most important causes of beam loss, was made based on Tricomp (Field precision)

  8. Electron postgrowth irradiation of platinum-containing nanostructures grown by electron-beam-induced deposition from Pt(PF3)4

    NARCIS (Netherlands)

    Botman, A.; Hagen, C.W.; Li, J.; Thiel, B.L.; Dunn, K.A.; Mulders, J.J.L.; Randolph, S.; Toth, M.

    2009-01-01

    The material grown in a scanning electron microscope by electron beam-induced deposition (EBID) using Pt(PF3)4 precursor is shown to be electron beam sensitive. The effects of deposition time and postgrowth electron irradiation on the microstructure and resistivity of the deposits were assessed by

  9. Beam-Beam effects at the CMS BRIL van-der-Meer scans

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is devoted to the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS Experiment at CERN. The project is engaged in operating and developing new detectors, compatible with the high luminosity experimental environments at the LHC. BRIL operates several detectors based on different physical principles and technologies. The detectors are calibrated using van-der-Meer scans to measure the luminosity that is a fundamental quantity of the LHC beam. In van-der-Meer scans the count rate in a detector is measured as a function of the distance between beams in the plane perpendicular to beam direction, to extract the underlying beam overlap area. The goal of the van-der-Meer scans is to obtain the calibration constant for each luminometer to be used at calibration then in physics data taking runs. The note presents the overview of beam-beam effects at the van-der-Meer scan and the corresponding corrections that sh...

  10. Ion-beam induced structure modifications in amorphous germanium; Ionenstrahlinduzierte Strukturmodifikationen in amorphem Germanium

    Energy Technology Data Exchange (ETDEWEB)

    Steinbach, Tobias

    2012-05-03

    Object of the present thesis was the systematic study of ion-beam induced structure modifications in amorphous germanium (a-Ge) layers due to low- (LEI) and high-energetic (SHI) ion irradiation. The LEI irradiation of crystalline Ge (c-Ge) effects because the dominating nuclear scattering of the ions on the solid-state atoms the formation of a homogeneous a-Ge Layer. Directly on the surface for fluences of two orders of magnitude above the amorphization fluence the formation of stable cavities independently on the irradiation conditions was observed. For the first time for the ion-beam induced cavity formation respectively for the steady expansion of the porous layer forming with growing fluence a linear dependence on the energy {epsilon}{sub n} deposed in nuclear processes was detected. Furthermore the formation of buried cavities was observed, which shows a dependence on the type of ions. While in the c-Ge samples in the range of the high electronic energy deposition no radiation defects, cavities, or plastic deformations were observed, the high electronic energy transfer in the 3.1 {mu}m thick pre-amorphized a-Ge surface layers leads to the formation of randomly distributed cavities. Basing on the linear connection between cavity-induced vertical volume expansion and the fluence determined for different energy transfers for the first time a material-specific threshold value of {epsilon}{sub e}{sup HRF}=(10.5{+-}1.0) kev nm{sup -1} was determined, above which the ion-beam induced cavity formation in a-Ge sets on. The anisotropic plastic deformation of th a-Ge layer superposed at inclined SHI irradiation on the cavity formation was very well described by an equation derived from the viscoelastic Maxwell model, but modified under regardment of the experimental results. The positive deformation yields determined thereby exhibit above a threshold value for the ion-beam induced plastic deformation {epsilon}{sub e}{sup S{sub a}}=(12{+-}2) keV nm{sup -1} for the first

  11. Simulation Studies of Beam-Beam Effects of a Ring-Ring Electron-Ion Collider Based on CEBAF

    Energy Technology Data Exchange (ETDEWEB)

    Yuhong Zhang,Ji Qiang

    2009-05-01

    The collective beam-beam effect can potentially cause a rapid growth of beam sizes and reduce the luminosity of a collider to an unacceptably low level. The ELIC, a proposed ultra high luminosity electron-ion collider based on CEBAF, employs high repetition rate crab crossing colliding beams with very small bunch transverse sizes and very short bunch lengths, and collides them at up to 4 interaction points with strong final focusing. All of these features can make the beam-beam effect challenging. In this paper, we present simulation studies of the beam-beam effect in ELIC using a self-consistent strong-strong beam-beam simulation code developed at Lawrence Berkeley National Laboratory. This simulation study is used for validating the ELIC design and for searching for an optimal parameter set.

  12. Limitations Imposed by Beam-Beam Effects and Their Remedies

    International Nuclear Information System (INIS)

    Spencer, James E.

    2000-01-01

    Effects that limit the luminosities of a general purpose linear collider or GLC capable of spin polarized e ± e ± , gamma-e ± and spin polarized gamma-gamma incident channels are discussed together with potential mitigations. The relative characteristics of such channels and their luminosities are predicted based on differing assumptions - including those for the current configurations for the NLC at square root s ee = 0.5 and 1.0 TeV. Disadvantages related to the increased complexity of linear colliders can be offset by broader design constraints that seek to optimize the generalized luminosity. Decreased disruptions and bunch charges are effective and can be used in combination with feasible charge compensation schemes to predict higher luminosities and power conversion efficiencies. The incremental costs of additional channels is modest compared to the cost of any one by itself or potential gains in the integrated luminosity

  13. Effects of prestressing on impact resistance of concrete beams

    International Nuclear Information System (INIS)

    Mikami, H.; Kishi, N.; Matsuoka, K.G.; Mikami, T.; Nomachi, S.G.

    1995-01-01

    In this paper, the effects of prestressing on impact resistance of concrete beams using two types of prestressed concrete (PC) tendons are discussed based on experimental results. Aramids Fiber Reinforced Plastic rods and PC steel strand were used as PC tendons. To clarify the effects of prestressing on concrete beam impact resistance, dynamic behavior of prestressed and/or non-prestressed concrete beams with different PC tendon arrangements were considered. Impact test were performed using a 200 kg f free falling steel weight on to the center of beam. (author). 10 refs., 5 figs., 2 tabs

  14. The status and new trends of ion beam induced charge technique

    International Nuclear Information System (INIS)

    Lu Rongrong; Qiu Huiyuan; Zhu Dezhang

    2002-01-01

    Ion beam induced charge technique (IBIC) with low beam current (fA level) and high efficiency is a new development of nuclear microscopy. It has been widely applied to the fields of semiconductor and microelectronic materials. The principle and the experimental method of the IBIC technique were described and reviewed its status and new trends were reviewed

  15. Edge effect correction using ion beam figuring.

    Science.gov (United States)

    Yang, Bing; Xie, Xuhui; Li, Furen; Zhou, Lin

    2017-11-10

    The edge effect is regarded as one of the most difficult technical issues for fabricating large primary mirrors, as it can greatly reduce the key performance of the optical system. Ion beam figuring (IBF) has the advantage of no edge effect, so we can use it to remove high points on the edge and improve surface accuracy. The edge local correction method (ELCM) of IBF processes only the surface edge zone, and is very different from the current full caliber figuring method (FCFM). Therefore, it is necessary to study the ELCM of IBF. In this paper, the key factors of ELCM are analyzed, such as dwell time algorithm, edge data extension methods, and the outward dimension of the starting figuring point. At the same time, the distinctions between ELCM and FCFM are compared. Finally, a 142 mm diameter fused silica mirror is fabricated to verify the validity of the theoretical of ELCM. The experimental results indicate that the figuring precision and efficiency can be obviously improved by ELCM.

  16. In vitro studies to evaluate the antioxidant property of salidroside and rosavin and protective effects of electron beam radiation induced damages in human dermal fibroblasts

    International Nuclear Information System (INIS)

    Tejashvi, Kedilaya R.; Padma, Shetty K.; Suchetha Kumari, N.

    2014-01-01

    Rosavin and Salidroside are active component of Rhodiola rosea, it is a phenylpropanoid derivative of plant. Rhodiola rosea, also known as 'golden root' or 'roseroot' belongs to the plant family Crassulaceae. Rhodiola grows primarily in dry sandy ground at high altitudes in the arctic areas of Europe and Asia. Plant is rich with phenolic compounds, known to have a strong antioxidant property. Studies have shown that Rhodiola rosea has a capacity to decrease toxicity of Adriamycin (anti-cancer drugs), while it enhances their anti-carcinogenic effects. Enhanced antioxidant activity of Rhodiola rosea play role in the prevention of both chronic disease and aging. Present study is aimed to determine the antioxidant property of Rosavin and Salidroside and dose determination on human dermal fibroblast against dermal fibroblast. Rosavin and Salidroside were dissolved in 10% DMSO. Invitro biochemical assays like DPPH radical scavenging assay, Ferric Anion Reducing Potential using TPTZ, Nitric Oxide scavenging assay, Total antioxidant determination assay, Super Anion Radical Scavenging assays were carried out to know property of the extract. Extracts were then treated on monolayer dermal fibroblast cells survival assay was performed. Salidroside has shown 80% total antioxidant property compare to Rosavin with respect Ascorbic acid as a standard. 100'R concentration of Salidroside and Rosavin has quite equal potential to scavenging DPPH similar like Ascorbic acid. Ferric Anion Reducing Potential using TPTZ, Nitric Oxide scavenging assays have also shown both Salidroside and Rosavin has a good antioxidant property. Invitro studies on dermal fibroblast have shown remarkable protective effect on normal and irradiated groups. (author)

  17. Microscopic kinetic analysis of space-charge induced optical microbunching in a relativistic electron beam

    Directory of Open Access Journals (Sweden)

    Agostino Marinelli

    2010-11-01

    Full Text Available Longitudinal space-charge forces from density fluctuations generated by shot noise can be a major source of microbunching instability in relativistic high brightness electron beams. The gain in microbunching due to this effect is broadband, extending at least up to optical frequencies, where the induced structure on the beam distribution gives rise to effects such as coherent optical transition radiation. In the high-frequency regime, theoretical and computational analyses of microbunching formation require a full three-dimensional treatment. In this paper we address the problem of space-charge induced optical microbunching formation in the high-frequency limit when transverse thermal motion due to finite emittance is included for the first time. We derive an analytical description of this process based on the beam’s plasma dielectric function. We discuss the effect of transverse temperature on the angular distribution of microbunching gain and its connection to the physics of Landau damping in longitudinal plasma oscillations. Application of the theory to a relevant experimental scenario is discussed. The analytical results obtained are then compared to the predictions arising from high resolution three-dimensional molecular dynamics simulations.

  18. Underling modification in ion beam induced Si wafers

    International Nuclear Information System (INIS)

    Hazra, S.; Chini, T.K.; Sanyal, M.K.; Grenzer, J.; Pietsch, U.

    2005-01-01

    Subsurface (amorphous-crystalline interface) structure of keV ion beam modified Si(001) wafers was studied for the first time using non-destructive technique and compared with that of the top one. Ion-beam modifications of the Si samples were done using state-of-art high-current ion implanter facility at Saha Institute of Nuclear Physics by changing energy, dose and angle of incidence of the Ar + ion beam. To bring out the underlying modification depth-resolved x-ray grazing incidence diffraction has been carried out using synchrotron radiation facility, while the structure of the top surface was studied through atomic force microscopy

  19. Proton induced radioactivity estimation and radiological safety aspects of materials science beam line at medical cyclotron

    International Nuclear Information System (INIS)

    Srivastava, S.K.; Nair, K.G.M.; Sarangapani, R.

    2012-01-01

    A medical cyclotron facility is under development in Kolkata. This medical cyclotron would deliver 15 - 30 MeV H + ions with beam current up to 500 μA. Though this facility will be mainly used for production of medically useful isotopes, a beam line has been also provided for materials science research. The materials science beam line will be used to study radiation damage in nuclear materials. Apart from radiation damage studies, material science beam line will be used for thin layer activation analysis, charged particle activation analysis and production of special isotopes. High intensity proton beam in this energy regime can induce high level of radioactivity in the target material and other beam line components. Hence it is necessary to calculate the induced radioactivity for a variety of materials, so as to find a suitable candidate for use in beam line components, to design radiation shielding and to design proper target handling devices and shielding arrangements. There are two ways by which radioactivity in beam line components can be induced, either by direct interaction of proton beam or by neutrons emitted from target during irradiation. The cross-section of production of various radionuclides and neutrons at different energies produced as a result of nuclear reaction between proton and target atoms has been generated using ALICE code. These cross-sections are used to calculate concentration of radionuclides and emitted neutron spectrum. The decay scheme of radionuclides is taken from Universal Nuclide Chart. Neutron induced activity in target chamber is estimated using MCNP code. These calculations have found to be very useful in the material selection for beam line components and designing radiation shielding. Various aspects of radioactivity calculations and radiological safety on material science beam line will be discussed. (author)

  20. Salvage proton beam therapy for recurrent iris melanoma: outcome and side effects.

    Science.gov (United States)

    Riechardt, Aline I; Klein, Julian P; Cordini, Dino; Heufelder, Jens; Rehak, Matus; Seibel, Ira; Joussen, Antonia M

    2018-02-20

    This study aims to analyze the effect of salvage proton beam therapy for the treatment of recurrent iris melanoma. In this clinical case series, we retrospectively analyzed the data of eight patients who underwent proton beam therapy of the whole anterior segment as salvage therapy between 2000 and 2016 for recurrent iris melanoma after resection, ruthenium brachytherapy, or sector proton beam therapy. Two patients received salvage proton beam therapy for repeated tumor relapse. All patients were observed and prepared for proton beam therapy at the Charité and irradiated at the Helmholtz-Zentrum Berlin where they received 50 cobalt Gray equivalents (CGE) in four daily fractions. We investigated survival rates and ocular outcome. Median follow-up after salvage proton beam therapy was 39 months. No local recurrence was detected during follow-up. One patient died from hepatic metastases 5.5 years after salvage therapy. Secondary glaucoma occurred in seven out of eight patients during follow-up. Two patients had chronic corneal erosion and two other patients presented with corneal decompensation, necessitating Descemet membrane endothelial keratoplasty (DMEK), and perforating keratoplasty. Median visual acuity was 0.2 logMAR before salvage proton beam therapy and 0.7 logMAR at the end of follow-up. Whole anterior segment salvage proton beam therapy has effectively controlled recurrent iris melanoma in our patients, but has been associated with a high incidence of radiation-induced corneal impairment and secondary glaucoma requiring extensive secondary treatment.

  1. The effect of material heterogeneity in curved composite beams for use in aircraft structures

    Science.gov (United States)

    Otoole, Brendan J.; Santare, Michael H.

    1992-01-01

    A design tool is presented for predicting the effect of material heterogeneity on the performance of curved composite beams for use in aircraft fuselage structures. Material heterogeneity can be induced during processes such as sheet forming and stretch forming of thermoplastic composites. This heterogeneity can be introduced in the form of fiber realignment and spreading during the manufacturing process causing a gradient in material properties in both the radial and tangential directions. The analysis procedure uses a separate two-dimensional elasticity solution for the stresses in the flanges and web sections of the beam. The separate solutions are coupled by requiring the forces and displacements match at the section boundaries. Analysis is performed for curved beams loaded in pure bending and uniform pressure. The beams can be of any general cross-section such as a hat, T-, I-, or J-beam. Preliminary results show that geometry of the beam dictates the effect of heterogeneity on performance. Heterogeneity plays a much larger role in beams with a small average radius to depth ratio, R/t, where R is the average radius of the beam and t is the difference between the inside and outside radius. Results of the analysis are in the form of stresses and displacements, and they are compared to both mechanics of materials and numerical solutions obtained using finite element analysis.

  2. Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

    Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: -> Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. -> Deconvolution of the luminosity spectrum distortion due to the ISR emission. -> Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

  3. Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

    Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: - Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. - Deconvolution of the luminosity spectrum distortion due to the ISR emission. - Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

  4. Size effects on free vibration of heterogeneous beams

    Directory of Open Access Journals (Sweden)

    Hassanati Bahman

    2018-01-01

    Full Text Available In this paper the influence of microstructure on the free vibration of geometrically similar heterogeneous beams with free-free boundary conditions was numerically investigated by detailed finite element analysis (FEA to identify and quantify any effect of beam size on transverse modal frequencies when the microstructural scale is comparable to the overall size. ANSYS Mechanical APDL was used to generate specific unit cells at the microstructural scale comprised of two isotropic materials with different material properties. Unit cell variants containing voids and inclusions were considered. At the macroscopic scale, four beam sizes consisting of one, two, three or four layers of defined unit cells were represented by repeatedly regenerating the unit cell as necessary. In all four beam sizes the aspect ratio was kept constant. Changes to the volume fractions of each material were introduced while keeping the homogenized properties of the beam fixed. The influence of the beam surface morphology on the results was also investigated. The ANSYS results were compared with the analytical results from solution to Timoshenko beam and nonlocal Timoshenko beam as well as numerical results for a Micropolar beam. In nonlocal Timoshenko beams the Eringen’s small length scale coefficients were estimated for some of the studied models. Numerical analyses based on Micropolar theory were carried out to study the modal frequencies and a method was suggested to estimate characteristic length in bending and coupling number via transverse vibration which verifies the use of Micropolar elasticity theory in dynamic analysis.

  5. Initiating the explosive decomposition of heavy metal azides by electron-beam-induced electric discharge

    Science.gov (United States)

    Oleshko, V. I.; Damamme, G.; Malys, D.; Lisitsyn, V. M.

    2009-10-01

    The explosive decomposition of heavy metal azides (HMAs) initiated by the electric (streamer) discharge induced by a nanosecond electron beam has been experimentally studied. A physical model is proposed that describes the initiation of an electron-beam-induced HMA explosion, which involves the formation of a strong electric field in a sample and its neutralization by a supersonic anode discharge. The propagating streamer front generates hot spots in a condensed reactive substance, from which the foci of explosive decomposition are formed.

  6. The polarization and beaming effect for GRBs

    OpenAIRE

    Cheng, K. S.; Fan, J. H.; Dai, Z. G.

    1999-01-01

    Both observations and theoretical models suggest that the emissions in gamma-ray bursts (GRBs) and the afterglows are beamed. We argue that the recent polarization measured in the afterglows gives further evidence of beaming in GRBs. In this approach, we adopted the polarization-magnitude relation of BL Lacertae objects to 4 GRBs with available polarization measurements and found that the data of the 4 GRBs are consistent with the relation of BL Lacertae objects. This result suggests that the...

  7. Laser beam shaping for studying thermally induced damage

    CSIR Research Space (South Africa)

    Masina, BN

    2011-08-01

    Full Text Available This paper presents an implementation of a laser beam shaping system for both heating a diamond tool and measuring the resulting temperature optically. The influence the initial laser parameters have on the resultant temperature profiles is shown...

  8. Effect of layer length on deflection in sandwich beams

    Science.gov (United States)

    Abbu, Muthanna A.; AL-Ameri, Riyadh

    2017-09-01

    A theoretical study has been carried out on sandwich beams strengthened mechanically by two external steel plates attached to their tension and compression sides with so-called "shear connectors ". This study is based on the individual behaviour of each component of the composite sandwich section (i.e. reinforced concrete beam and upper steel plate and lower steel plate). The approach has been developed to simulate the behaviour of such beams, and is based on neglecting the separation between the three layers; i.e., the deflections are equal in each element through the same section. The differential equations reached were solved analytically. Deflection was calculated by using the approach for several beams, tested in two series, and close agreements were obtained with the experimental values. Furthermore, the interaction efficiency between the three elements in a composite sandwich beam has been considered thoroughly, from which the effect of some parameters, such as plate length upon the behaviour of such beams, were studied.

  9. In situ growth optimization in focused electron-beam induced deposition

    Directory of Open Access Journals (Sweden)

    Paul M. Weirich

    2013-12-01

    Full Text Available We present the application of an evolutionary genetic algorithm for the in situ optimization of nanostructures that are prepared by focused electron-beam-induced deposition (FEBID. It allows us to tune the properties of the deposits towards the highest conductivity by using the time gradient of the measured in situ rate of change of conductance as the fitness parameter for the algorithm. The effectiveness of the procedure is presented for the precursor W(CO6 as well as for post-treatment of Pt–C deposits, which were obtained by the dissociation of MeCpPt(Me3. For W(CO6-based structures an increase of conductivity by one order of magnitude can be achieved, whereas the effect for MeCpPt(Me3 is largely suppressed. The presented technique can be applied to all beam-induced deposition processes and has great potential for a further optimization or tuning of parameters for nanostructures that are prepared by FEBID or related techniques.

  10. Effect of electron beam on in vitro cultured orchid organs

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jaihyunk; Bae, Seho; Bae, Changhyu [Sunchon National Univ., Suncheon (Korea, Republic of); Kang, Hyun Suk; Lee, Byung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-07-01

    Ionizing radiations have been effective mutagen sources to overcome the limitation of the useful genetic resources in natural environment. The study was conducted to investigate an effect of electron beam on organogenesis, growth patterns and genetic variation in the irradiated orchid organs. The in utero cultured rhizomes of orchids were irradiated with the electron beam in the dose range of 15Gy to 2240Gy under the condition of various beam energy and beam current. Significant decreases in survival, growth and organogenesis were observed by increase of intensity of electron beam irradiation. The irradiation intensity of lethal dose 50 of the in utero cultured orchid was estimated as approximately 500Gy to 1000Gy under 10MeV/n, and 1000Gy was optimal for growth and organogenesis of the cultures under 10MeV/n with 0.05mA treatment, and 15Gy {approx} 48Gy under 2MeV/n and 0.5mA electron beam condition. RAPD and ISSR analyses for the electron beam irradiated organs were performed to analyze genetic variation under the electron beam condition. Both of RAPD and ISSR analyses showed higher polymorphic rate in the electron-beam irradiated C. gangrene and C. Kaner.

  11. Gamma and electron beam radiation induced physico-chemical modifications of poly(propylene)

    Science.gov (United States)

    Yagoubi, N.; Peron, R.; Legendre, B.; Grossiord, J. L.; Ferrier, D.

    1999-05-01

    The homopolymer PP, a plastic material used as packaging and for medical products, must be subjected to a form of sterilization. Nowadays, one kind of this technology uses ionising radiation, which can be γ-rays or electron beams. In order to study the structural modifications of polymer syringes which could occur following these treatments at different doses (25-150 kGy), several analytical techniques have been used. DSC provided information on changes in the cristallinity of the polymer. The thermal evaluation was supplemented by testing the rheological properties of polypropylene. In addition, Reversed Phase Liquid Chromatography (HPLC) with a quaternary elution gradient was carried out for the evaluation of the degradation of the additives. Thermogravimetric analysis (TGA) coupled with Fourier transform infrared (TGA/FTIR) was used to measure the desorption of food simulating liquid (CH 2Cl 2). First, the results obtained proved that the γ-rays as well as the electron beam induced degradation of the polymer and its additives. Next, we compared the effects of gamma and electron beam irradiation to determine which of these two processes better maintained the integrity of the irradiated product.

  12. Reaction mechanisms in collisions induced by $^{8}$B beam close to the barrier

    CERN Multimedia

    The aim of the proposed experiment is to investigate the reaction dynamics of proton-halo induced collisions at energies around the Coulomb barrier where coupling to continuum effects are expected to be important. We propose to measure the $^{8}$B + $^{64}$Zn elastic scattering angular distribution together with the measurement, for the first time, of p - $^{7}$Be coincidences coming from transfer and/or break-up of $^{8}$B. The latter will allow a better understanding of the relative contribution of elastic $\\textit{vs}$ non-elastic break-up in reactions induced by extremely weakly-bound nuclei. We believe that with the availability of the post accelerated $^{8}$B beam at REX-ISOLDE we will be able to collect for the first time high quality data for the study of such an important topic.

  13. Ion beam induced luminescence from diamond using an MeV ion microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A.; Jamieson, D. N.; Prawer, S.; Allen, M.G. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1993-12-31

    Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.

  14. Electron-beam curing of epoxy resins: effect of alcohols on cationic ...

    Indian Academy of Sciences (India)

    Unknown

    ing and fabrication costs of military systems, including fixed-winged and rotor aircraft, ground vehicles, ... hydroxyl groups, i.e. water, alcohol, polymer chain ends, and comonomer, can favour the AM mechanism. ... In this work, we investigate the effect of presence of water and alcohols on the e-beam induced polymerization.

  15. Beam induced hydrodynamic tunneling in the future circular collider components

    Directory of Open Access Journals (Sweden)

    N. A. Tahir

    2016-08-01

    Full Text Available A future circular collider (FCC has been proposed as a post-Large Hadron Collider accelerator, to explore particle physics in unprecedented energy ranges. The FCC is a circular collider in a tunnel with a circumference of 80–100 km. The FCC study puts an emphasis on proton-proton high-energy and electron-positron high-intensity frontier machines. A proton-electron interaction scenario is also examined. According to the nominal FCC parameters, each of the 50 TeV proton beams will carry an amount of 8.5 GJ energy that is equivalent to the kinetic energy of an Airbus A380 (560 t at a typical speed of 850  km/h. Safety of operation with such extremely energetic beams is an important issue, as off-nominal beam loss can cause serious damage to the accelerator and detector components with a severe impact on the accelerator environment. In order to estimate the consequences of an accident with the full beam accidently deflected into equipment, we have carried out numerical simulations of interaction of a FCC beam with a solid copper target using an energy-deposition code (fluka and a 2D hydrodynamic code (big2 iteratively. These simulations show that, although the penetration length of a single FCC proton and its shower in solid copper is about 1.5 m, the full FCC beam will penetrate up to about 350 m into the target because of the “hydrodynamic tunneling.” These simulations also show that a significant part of the target is converted into high-energy-density matter. We also discuss this interesting aspect of this study.

  16. Beam-beam effects in high energy e+e- storage rings: resonant amplification of vertical dimensions for flat beams

    International Nuclear Information System (INIS)

    Bambade, P.

    1984-06-01

    In this thesis, we present a phenomenological study of the beam-beam effect in e + e - storage rings. We are in particular interested in the blow-up of the vertical dimension observed in this kind of accelerator. A detailed analysis of the electromagnetic field generated by the very flat bunches stored, and seen by the counter-rotating particles shows that two-dimensional non-linear resonances, which couple vertical and horizontal betatron oscillations, play a very important role. Moreover, the ''weak beam-strong beam'' approximation holds rather well in the case of very flat bunches. Perturbative analysis enables us to predict the effects from the strongest coupling resonance: 20sub(x)-20sub(y) = integer. We find that mainly the tails of the vertical distribution are affected, and we give a criterion concerning the optimal distance to this resonance in the case of a storage ring such as LEP. Finally, the results and in particular the validity of the single resonance approximation are checked through a numerical simulation [fr

  17. LET effects of high energy ion beam irradiation on polysilanes

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Shu; Kanzaki, Kenichi; Tagawa, Seiichi; Yoshida, Yoichi [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research; Kudoh, Hisaaki; Sugimoto, Masaki; Sasuga, Tsuneo; Seguchi, Tadao; Shibata, Hiromi

    1997-03-01

    Thin films of poly(di-n-hexylsilane) were irradiated with 2-20 MeV H{sup +} and He{sup +} ion beams. The beams caused heterogeneous reactions of crosslinking and main chain scission in the films. The relative efficiency of the crosslinking was drastically changed in comparison with that of main chain scission. The anomalous change in the molecular weight distribution was analyzed with increasing irradiation fluence, and the ion beam induced reaction radius; track radius was determined for the radiation sources by the function of molecular weight dispersion. Obtained values were 59{+-}15 A and 14{+-}6 A for 2 MeV He{sup +} and 20 MeV H{sup +} ion beams respectively. (author)

  18. Beam-beam interaction and Pacman effects in the SSC with random nonlinear multipoles

    International Nuclear Information System (INIS)

    Goderre, G.P.; Ohnuma, S.

    1988-01-01

    In order to find the combined effects of beam-beam interaction (head-on and long-range) and random nonlinear multipoles in dipole magnets, transverse tunes and smears have been calculated as a function of oscillation amplitudes. Two types of particles, ''regular'' and ''Pacman,'' have been investigated using a modified version of tracking code TEAPOT. Regular particles experience beam-beam interactions in all four interaction regions (IR's), both head-on and long range, while pacman particles interact with bunches of the other beam in one medium-beta and one low-beta IR's only. The model for the beam-beam interaction is of weak-strong type and the strong beam is assumed to have a round Gaussian charge distribution. Furthermore, it is assumed that the vertical closed orbit deviation arising from the finite crossing angle of 70 μrad is perfectly compensated for regular particles. The same compensation applied to pacman particles creates a closed orbit distortion. Linear tunes are adjusted for regular particles to the design values but there are no nonlinear corrections except for chromaticity correcting sextupoles in two families. Results obtained in this study do not show any reduction of dynamic or linear aperture for pacman particles but some doubts exist regarding the validity of defining the linear aperture from the smear alone. Preliminary results are given for regular particles when (Δp/p) is modulated by the synchrotron oscillation. For these, fifty oscillations corresponding to 26,350 revolutions have been tracked. A very slow increase in the horizontal amplitude, /approximately/4 /times/ 10/sup /minus/4//oscillation (relative), is a possibility but this should be confirmed by trackings of larger number of revolutions. 11 refs., 18 figs., 2 tabs

  19. Beam Induced Hydrodynamic Tunneling in the Future Circular Collider Components

    CERN Document Server

    AUTHOR|(CDS)2083092; Burkart, Florian; Schmidt, Rudiger; Shutov, A; Wollmann, Daniel; Piriz, A

    2016-01-01

    A future circular collider (FCC) has been proposed as a post-Large Hadron Collider accelerator, to explore particle physics in unprecedented energy ranges. The FCC is a circular collider in a tunnel with a circumference of 80–100 km. The FCC study puts an emphasis on proton-proton high-energy and electron-positron high-intensity frontier machines. A proton-electron interaction scenario is also examined. According to the nominal FCC parameters, each of the 50 TeV proton beams will carry an amount of 8.5 GJ energy that is equivalent to the kinetic energy of an Airbus A380 (560 t) at a typical speed of 850  km/h . Safety of operation with such extremely energetic beams is an important issue, as off-nominal beam loss can cause serious damage to the accelerator and detector components with a severe impact on the accelerator environment. In order to estimate the consequences of an accident with the full beam accidently deflected into equipment, we have carried out numerical simulations of interaction of a FCC...

  20. Observation of helium flow induced beam orbit oscillations at RHIC

    International Nuclear Information System (INIS)

    Montag, C.; Bonati, R.; Brennan, J.M.; Butler, J.; Cameron, P.; Ganetis, G.; He, P.; Hirzel, W.; Jia, L.X.; Koello, P.; Louie, W.; McIntyre, G.; Nicoletti, A.; Rank, J.; Roser, T.; Satogata, T.; Schmalzle, J.; Sidi-Yekhlef, A.; Sondericker, J.; Tallerico, T.

    2006-01-01

    Horizontal beam orbit jitter at frequencies around 10 Hz has been observed at RHIC for several years. The distinct frequencies of this jitter have been found at superconducting low-beta quadrupole triplet magnets around the ring, where they coincide with mechanical vibration modes of the cold masses. Recently, we have identified liquid helium flow as the driving force of these oscillations

  1. Fast crystallization of amorphous Gd2Zr2O7 induced by thermally activated electron-beam irradiation

    Science.gov (United States)

    Huang, Zhangyi; Qi, Jianqi; Zhou, Li; Feng, Zhao; Yu, Xiaohe; Gong, Yichao; Yang, Mao; Shi, Qiwu; Wei, Nian; Lu, Tiecheng

    2015-12-01

    We investigate the ionization and displacement effects of an electron-beam (e-beam) on amorphous Gd2Zr2O7 synthesized by the co-precipitation and calcination methods. The as-received amorphous specimens were irradiated under electron beams at different energies (80 keV, 120 keV, and 2 MeV) and then characterized by X-ray diffraction and transmission electron microscopy. A metastable fluorite phase was observed in nanocrystalline Gd2Zr2O7 and is proposed to arise from the relatively lower surface and interface energy compared with the pyrochlore phase. Fast crystallization could be induced by 120 keV e-beam irradiation (beam current = 0.47 mA/cm2). The crystallization occurred on the nanoscale upon ionization irradiation at 400 °C after a dose of less than 1017 electrons/cm2. Under e-beam irradiation, the activation energy for the grain growth process was approximately 10 kJ/mol, but the activation energy was 135 kJ/mol by calcination in a furnace. The thermally activated ionization process was considered the fast crystallization mechanism.

  2. Detector dose response in megavoltage small photon beams. II. Pencil beam perturbation effects

    International Nuclear Information System (INIS)

    Bouchard, Hugo; Duane, Simon; Kamio, Yuji; Palmans, Hugo; Seuntjens, Jan

    2015-01-01

    Purpose: To quantify detector perturbation effects in megavoltage small photon fields and support the theoretical explanation on the nature of quality correction factors in these conditions. Methods: In this second paper, a modern approach to radiation dosimetry is defined for any detector and applied to small photon fields. Fano’s theorem is adapted in the form of a cavity theory and applied in the context of nonstandard beams to express four main effects in the form of perturbation factors. The pencil-beam decomposition method is detailed and adapted to the calculation of perturbation factors and quality correction factors. The approach defines a perturbation function which, for a given field size or beam modulation, entirely determines these dosimetric factors. Monte Carlo calculations are performed in different cavity sizes for different detection materials, electron densities, and extracameral components. Results: Perturbation effects are detailed with calculated perturbation functions, showing the relative magnitude of the effects as well as the geometrical extent to which collimating or modulating the beam impacts the dosimetric factors. The existence of a perturbation zone around the detector cavity is demonstrated and the approach is discussed and linked to previous approaches in the literature to determine critical field sizes. Conclusions: Monte Carlo simulations are valuable to describe pencil beam perturbation effects and detail the nature of dosimetric factors in megavoltage small photon fields. In practice, it is shown that dosimetric factors could be avoided if the field size remains larger than the detector perturbation zone. However, given a detector and beam quality, a full account for the detector geometry is necessary to determine critical field sizes

  3. Nonlinear space charge effect of bunched beam in linac

    International Nuclear Information System (INIS)

    Chen Yinbao

    1992-02-01

    The nonlinear space charge effect due to the nonuniform particle density distribution in bunched beam of a linac is discussed. The formulae of nonlinear space charge effect and nonlinear focusing forces were derived for the bunched beam with Kapchinskij-Vladimirskij (K-V) distribution, waterbag (WB) distribution, parabolic (PA) distribution, and Gauss (GA) distribution in both of the space charge disk model and space charge cylinder model in the waveguide of a linac

  4. Electron beam induced modification of poly(ethylene terephthalate) films

    International Nuclear Information System (INIS)

    Vasiljeva, I.V.; Mjakin, S.V.; Makarov, A.V.; Krasovsky, A.N.; Varlamov, A.V.

    2006-01-01

    Electron beam processing of poly(ethylene terephthalate) (PET) films is found to promote significant changes in the melting heat, intrinsic viscosity and polymer film-liquid (water, isooctane and toluene) boundary surface tension. These properties are featured with several maximums depending on the absorbed dose and correlating with the modification of PET surface functionality. Studies using adsorption of acid-base indicators and IR-spectroscopy revealed that the increase of PET surface hydrophilicity is determined by the oxidation of methylene and methyne groups. Electron beam treatment of PET films on the surface of N-vinylpyrrolidone aqueous solution provided graft copolymerization with this comonomer at optimum process parameters (energy 700 keV, current 1 mA, absorbed dose 50 kGy)

  5. Neutral beam and ICP etching of HKMG MOS capacitors: Observations and a plasma-induced damage model

    Science.gov (United States)

    Kuo, Tai-Chen; Shih, Tzu-Lang; Su, Yin-Hsien; Lee, Wen-Hsi; Current, Michael Ira; Samukawa, Seiji

    2018-04-01

    In this study, TiN/HfO2/Si metal-oxide-semiconductor (MOS) capacitors were etched by a neutral beam etching technique under two contrasting conditions. The configurations of neutral beam etching technique were specially designed to demonstrate a "damage-free" condition or to approximate "reactive-ion-etching-like" conditions to verify the effect of plasma-induced damage on electrical characteristics of MOS capacitors. The results show that by neutral beam etching (NBE), the interface state density (Dit) and the oxide trapped charge (Qot) were lower than routine plasma etching. Furthermore, the decrease in capacitor size does not lead to an increase in leakage current density, indicating less plasma induced side-wall damage. We present a plasma-induced gate stack damage model which we demonstrate by using these two different etching configurations. These results show that NBE is effective in preventing plasma-induced damage at the high-k/Si interface and on the high-k oxide sidewall and thus improve the electrical performance of the gate structure.

  6. Transverse wakefield effects in the two-beam accelerator

    International Nuclear Information System (INIS)

    Selph, F.; Sessler, A.

    1986-01-01

    Transverse wakefield effects in the high-gradient accelerating structure of the two-beam accelerator (TBA) are analyzed theoretically using three different models. The first is a very simple two-particle model, the second is for a beam with uniform charge distribution, constant betatron wavelength, and a linear wake approximation. Both of these models give analytic scaling laws. The third model has a Gaussian beam (represented by 11 superparticles), energy variation across the bunch, acceleration, variation of betatron focusing with energy, and variation of the wakefield from linearity. The three models are compared, and the third model is used to explore the wakefield effects when accelerator parameters such as energy, energy spread, injection energy, accelerating gradient, and betatron wavelength are varied. Also explored are the sensitivity of the beam to the wakefield profile to the longitudinal charge distribution. Finally, in consideration of wakefield effects, possible parameters of a TBA are presented. (orig./HSI)

  7. Proton-induced knockout reactions with polarized and unpolarized beams

    Science.gov (United States)

    Wakasa, T.; Ogata, K.; Noro, T.

    2017-09-01

    Proton-induced knockout reactions provide a direct means of studying the single particle or cluster structures of target nuclei. In addition, these knockout reactions are expected to play a unique role in investigations of the effects of the nuclear medium on nucleon-nucleon interactions as well as the properties of nucleons and mesons. However, due to the nature of hadron probes, these reactions can suffer significant disturbances from the nuclear surroundings and the quantitative theoretical treatment of such processes can also be challenging. In this article, we review the experimental and theoretical progress in this field, particularly focusing on the use of these reactions as a spectroscopic tool and as a way to examine the medium modification of nucleon-nucleon interactions. With regard to the former aspect, the review presents a semi-quantitative evaluation of these reactions based on existing experimental data. In terms of the latter point, we introduce a significant body of evidence that suggests, although does not conclusively prove, the existence of medium effects. In addition, this paper also provides information and comments on other related subjects.

  8. Beam diagnostics for Laser-induced proton generation at KAERI

    International Nuclear Information System (INIS)

    Kim, Dong Heun; Park, Seong Hee; Jeong, Young Uk; Lee, Ki Tae; Chan, Young Ho; Lee, Byung Cheol; Yoo, Byeong Duk

    2005-01-01

    With an advent of femto-second lasers, a laseraccelerated ion generation has been world-widely studied for medical and nuclear applications. It is known that protons with the energy from several tens MeV to a few hundreds MeV require for a cancer therapy and nuclear reaction. Even though, up to present, the maximum energy of laser-accelerated proton is about 60 MeV, it is expected that the energy of protons generated can be obtained at least up to 150 MeV. According to theoretical and experimental works, it turns out the energy distribution and the flux of ions strongly depends on the intensity of a fs laser at a target. However, physics on laser-plasma interaction is still not clear. The precise measurements of parameters of a fs laser and ions are important to figure out the physics and develop the theoretical interpretation. Typically, beam diagnostic system includes measurements and/or monitoring of the temporal and spatial profiles of lasers at the target as well as the energy spectrum and density profile of protons, which are critical for the analysis of mechanism and the characterization of protons generated. We fabricated and installed the target chamber for laser-accelerated proton generation and are now integrating beam diagnostic system. For laser diagnostics, beam monitoring and alignment system has been installed. For a charged particle, CR-39 detectors, Thomson parabola spectrometer, and Si charged particle detectors are installed for density profile and energy spectrum. In this paper, we discuss the laser beam monitoring and alignment system. We also estimates expected spectrum of protons from Thomson parabola spectrometer, depending on the parameters of protons

  9. Electrical Characterisation of electron beam exposure induced Defects in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Danga, Helga T., E-mail: helga.danga@up.ac.za; Auret, Francois D.; Coelho, Sergio M.M.; Diale, Mmantsae

    2016-01-01

    The defects introduced in epitaxially grown p-type silicon (Si) during electron beam exposure were electrically characterised using deep level transient spectroscopy (DLTS) and high resolution Laplace-DLTS. In this process, Si samples were first exposed to the conditions of electron beam deposition (EBD) without metal deposition. This is called electron beam exposure (EBE) herein. After 50 minutes of EBE, nickel (Ni) Schottky contacts were fabricated using the resistive deposition method. The defect level observed using the Ni contacts had an activation energy of H(0.55). This defect has an activation energy similar to that of the I-defect. The defect level is similar to that of the HB4, a boron related defect. DLTS depth profiling revealed that H(0.55) could be detected up to a depth of 0.8 μm below the junction. We found that exposing the samples to EBD conditions without metal deposition introduced a defect which was not introduced by the EBD method. We also observed that the damage caused by EBE extended deeper into the material compared to that caused by EBD.

  10. HOLLOW ELECTRON BEAM COLLIMATION FOR HL-LHC - EFFECT ON THE BEAM CORE

    Energy Technology Data Exchange (ETDEWEB)

    Fitterer, M. [Fermilab; Stancari, G. [Fermilab; Valishev, A. [Fermilab; Bruce, R. [CERN; Papadopoulou, S. [CERN; Papotti, G. [CERN; Pellegrini, D. [CERN; Pellegrini, S. [CERN; Valuch, D. [CERN; Wagner, J. F. [CERN

    2016-10-05

    Collimation with hollow electron beams or lenses (HEL) is currently one of the most promising concepts for active halo control in HL-LHC. In previous studies it has been shown that the halo can be efficiently removed with a hollow electron lens. Equally important as an efficient removal of the halo, is also to demonstrate that the core stays unperturbed. In this paper, we present a summary of the experiment at the LHC and simulations in view of the effect of the HEL on the beam core in case of a pulsed operation.

  11. Hollow Electron Beam Collimation For HL-LHC - Effect On The Beam Core

    CERN Document Server

    Fitterer, M; Valishev, A; Bruce, R; Papadopoulou, S; Papotti, G; Pellegrini, D; Redaelli, S; Valuch, D; Wagner, J F

    2017-01-01

    Collimation with hollow electron beams or lenses (HEL) is currently one of the most promising concepts for active halo control in HL-LHC. In previous studies it has been shown that the halo can be efficiently removed with a hollow electron lens. Equally important as an efficient removal of the halo, is also to demonstrate that the core stays unperturbed. In this paper, we present a summary of the experiment at the LHC and simulations in view of the effect of the HEL on the beam core in case of a pulsed operation.

  12. Emittance Growth of the LHC Beam due to the Effect of Head-on Beam-Beam Interaction and Ground Motion

    CERN Document Server

    Sen, T

    2000-01-01

    The influence of ground motion on the LHC beam is estimated by applying the existing theories of particle diffusion due to a weak-strong beam-beam collision with random offset at the interaction point. Noise at odd harmonics of the betatron frequency contributes significantly to particle diffusion. Extrapolating the characteristics of the random offset from the ground motion spectrum at the LHC site shows a fast fall-off with frequency and the amplitude is very small even at the first harmonic. We find that the head-on beam-beam force in the weak-strong approximation and ground motion by themselves do not induce significant diffusion over the lifetime of the beam.

  13. Extrinsic Influence of Environment-Induced Degradation on Load Carrying Capacity of Steel Beams

    Science.gov (United States)

    Gowda, Sunil; Patnaik, A.; Payer, J.; Srivatsan, T. S.

    2015-11-01

    In this paper, the results of a study aimed at evaluating the strength of wide-flanged beams subjected to corrosion-induced damage, modeled using a standard finite element program (ABAQUS) is presented and discussed. Typical beams in consideration were subjected to different cases of corrosion-induced damage, such as non-uniform and varying degree of material loss that simulates pitting corrosion. Many variables, such as (a) shape of pitting damage, (b) location of pits along the length of the beam, (c) number of pits, and (d) depth of pits, were considered to facilitate a better understanding of the load carrying capacity of steel I-beams having damage quite similar to pitting damage to the web. The results are compared with an "as-new" beam for purpose of evaluation of the reduction in strength due to environment-induced deterioration. A "corrosion strength reduction factor (CSRF)" is introduced to help identify the reduction in load carrying capacity as a consequence of both height and depth of the damage due to corrosion. The results are presented in charts for purpose of practical beam design.

  14. 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.

  15. Investigation of chemical vapour deposition diamond detectors by X- ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    CERN Document Server

    Olivero, P; Vittone, E; Fizzotti, F; Paolini, C; Lo Giudice, A; Barrett, R; Tucoulou, R

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the Large Hadron Collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of "detector grade" artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro- beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitati...

  16. Effect of electron beam irradiation on nutritional ingredient of Tegillarca granosa meat

    International Nuclear Information System (INIS)

    Li Chao; Yang Wenge; Xu Dalun; Ou Changrong; Shi Huidong

    2011-01-01

    The influences of 0, 1, 3, 5, 7 and 9 kGy electron beam irradiation on the contents of protein and amino acid and the composition of amino acids and fatty acids in Tegillarca granosa meat were investigated. The results showed that the electron beam had no significant effect on contents of moisture, ash and protein. Fat was sensitive to electron beam irradiation, which decreased with the increasing of irradiation dose. The composition of amino acids remained stable with different doses. The values of EAA/TAA and EAA/NEAA were kept in accordance with FAO/WHO protein model. Besides, electron beam irradiation made no effect on the limiting amino acid (the first and second limiting amino acids were Met + Cys and Val, respectively). The relative content of PUFA increased significantly 1 ∼ 7 kGy irradiation. Electron beam irradiation produced a notable impact on the essential fatty acid, induced the increase of linoleic acid, linolenic acid and arachidonic acid at the doses of 5 ∼ 9 kGy. After the irradiation of 9 kGy, the increments of relative contents of the three essential fatty acids reached 94.61%, 41.37% and 89.91%, respectively. Electron beam irradiation had positive effect on EPA with the doses of 3, 5 and 9 kGy. However, DHA was sensitive to electron beam irradiation, whose relative content decreased with the increasing of irradiation dose and undetected at the dose of 9 kGy. According to the research of decontamination effect, the recommended dose of electron beam irradiation on Tegillarca granosa ws fixed at 3 ∼ 5 kGy. (authors)

  17. Modal Analysis and Measurement of Water Cooling Induced Vibrations on a CLIC Main Beam Quadrupole Prototype

    CERN Document Server

    Artoos, K; Esposito, M; Fernandez Carmona, P; Guinchard, M; Janssens, S; Leuxe, R; Modena, M; Moron Ballester, R; Struik, M; Deleglise, C; Jeremie, A

    2011-01-01

    To reach the Compact Linear Collider (CLIC) design luminosity, the mechanical jitter of the CLIC main beam quadrupoles should be smaller than 1.5 nm integrated root mean square (r.m.s.) displacement above 1 Hz. A stiff stabilization and nano-positioning system is being developed but the design and effectiveness of such a system will greatly depend on the stiffness of the quadrupole magnet which should be as high as possible. Modal vibration measurements were therefore performed on a first assembled prototype magnet to evaluate the different mechanical modes and their frequencies. The results were then compared with a Finite Element (FE) model. The vibrations induced by water-cooling without stabilization were measured with different flow rates. This paper describes and analyzes the measurement results.

  18. Electron beam induced etching of carbon nanotubes enhanced by secondary electrons in oxygen

    Science.gov (United States)

    Yoshida, Hideto; Tomita, Yuto; Soma, Kentaro; Takeda, Seiji

    2017-05-01

    Multi-walled carbon nanotubes (CNTs) are subjected to electron-beam-induced etching (EBIE) in oxygen. The EBIE process is observed in situ by environmental transmission electron microscopy. The partial pressure of oxygen (10 and 100 Pa), energy of the primary electrons (80 and 200 keV), and environment of the CNTs (suspended or supported on a silicon nitride membrane) are investigated as factors affecting the etching rate. The EBIE rate of CNTs was markedly promoted by the effects of secondary electrons that were emitted from a silicon nitride membrane under irradiation by primary electrons. Membrane supported CNTs can be cut by EBIE with a spatial accuracy better than 3 nm, and a nanogap of 2 nm can be successfully achieved between the ends of two suspended CNTs.

  19. Residual activity induced by heavy ions and beam-loss criteria for heavy-ion accelerators

    Directory of Open Access Journals (Sweden)

    I. Strašík

    2010-07-01

    Full Text Available The paper presents results of FLUKA simulations of the residual activity induced by heavy ions in two target configurations representing: (1 a beam pipe of an accelerator and (2 a bulky accelerator structure like a magnet yoke or a coil. The target materials were stainless steel and copper representing the most common construction materials used for basic accelerator components. For these two materials, the inventory of the induced isotopes depends mainly on the target material and much less on the projectile species. Time evolution of the induced activity can be described by means of a generic curve that is independent from the projectile mass. Dependence of the induced residual activity on selected ion beam parameters was studied. The main goal of the study was establishing a scaling law expanding the existing proton beam-loss tolerance to heavy-ion beams. This scaling law enables specifying beam-loss criteria for projectile species from proton up to uranium at energies from 200  MeV/u up to 1  GeV/u.

  20. Head-On Beam-Beam Interactions in High-Energy Hadron Colliders. GPU-Powered Modelling of Nonlinear Effects

    CERN Document Server

    AUTHOR|(CDS)2160109; Støvneng, Jon Andreas

    2017-08-15

    The performance of high-energy circular hadron colliders, as the Large Hadron Collider, is limited by beam-beam interactions. The strength of the beam-beam interactions will be higher after the upgrade to the High-Luminosity Large Hadron Collider, and also in the next generation of machines, as the Future Circular Hadron Collider. The strongly nonlinear force between the two opposing beams causes diverging Hamiltonians and drives resonances, which can lead to a reduction of the lifetime of the beams. The nonlinearity makes the effect of the force difficult to study analytically, even at first order. Numerical models are therefore needed to evaluate the overall effect of different configurations of the machines. For this thesis, a new code named CABIN (Cuda-Accelerated Beam-beam Interaction) has been developed to study the limitations caused by the impact of strong beam-beam interactions. In particular, the evolution of the beam emittance and beam intensity has been monitored to study the impact quantitatively...

  1. Electron Beam-Induced Deposition for Atom Probe Tomography Specimen Capping Layers.

    Science.gov (United States)

    Diercks, David R; Gorman, Brian P; Mulders, Johannes J L

    2017-04-01

    Six precursors were evaluated for use as in situ electron beam-induced deposition capping layers in the preparation of atom probe tomography specimens with a focus on near-surface features where some of the deposition is retained at the specimen apex. Specimens were prepared by deposition of each precursor onto silicon posts and shaped into sub-70-nm radii needles using a focused ion beam. The utility of the depositions was assessed using several criteria including composition and uniformity, evaporation behavior and evaporation fields, and depth of Ga+ ion penetration. Atom probe analyses through depositions of methyl cyclopentadienyl platinum trimethyl, palladium hexafluoroacetylacetonate, and dimethyl-gold-acetylacetonate [Me2Au(acac)] were all found to result in tip fracture at voltages exceeding 3 kV. Examination of the deposition using Me2Au(acac) plus flowing O2 was inconclusive due to evaporation of surface silicon from below the deposition under all analysis conditions. Dicobalt octacarbonyl [Co2(CO)8] and diiron nonacarbonyl [Fe2(CO)9] depositions were found to be effective as in situ capping materials for the silicon specimens. Their very different evaporation fields [36 V/nm for Co2(CO)8 and 21 V/nm for Fe2(CO)9] provide options for achieving reasonably close matching of the evaporation field between the capping material and many materials of interest.

  2. Monte Carlo study of molecular weight distribution changes induced by degradation of ion beam irradiated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Chappa, V.C., E-mail: chappa@tandar.cnea.gov.a [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, B1650KNA San Martin, Buenos Aires (Argentina); CONICET (Argentina); Pastorino, C.; Grosso, M.F. dwel; Arbeitman, C.R. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, B1650KNA San Martin, Buenos Aires (Argentina); CONICET (Argentina); Mueller, M. [Institut fuer Theoretische Physik, Georg-August-Universitaet, Goettingen (Germany); Garci' a Bermudez, G. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, B1650KNA San Martin, Buenos Aires (Argentina); CONICET (Argentina); Escuela de Ciencia y Tecnologi' a, UNSAM (Argentina)

    2010-10-01

    In this work we study a polymeric material that degrades upon irradiation due to the energy inhomogeneously deposited by heavy ion beams. Ion beam irradiation of polymers generates rather different effects than those induced by 'classical' low ionizing particles such as electrons or gamma rays. This is due to the high electronic stopping power and the inhomogeneous distribution of deposited energy. This energy is transferred to the material within a small volume along the ion path forming the so called 'nuclear track' or 'latent track'. The track size primarily depends on the ion velocity, and it is determined by the secondary electrons (delta rays) generated along the ion trajectory. By means of Monte Carlo simulations we first obtained equilibrated polymer configurations using a coarse-grained model, and then investigated the spatially inhomogeneous chain scission process due to the passage of the ions. The number average molecular weight, weight average molecular weight and the polydispersity were calculated as a function of track radius, scission probability within the ion track and irradiation fluence. Finally we compared our results with a numerical implementation of a model for random homogeneous degradation.

  3. Quantum Interference of Multiple Beams Induced by Multiple Scattering

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Mortensen, N. Asger; Lodahl, Peter

    2011-01-01

    We report on quantum interference induced by the transmission of quantized light through a multiple-scattering medium. We show that entangled states can be created by multiple-scattering and that quantum interference survives disorder averaging.......We report on quantum interference induced by the transmission of quantized light through a multiple-scattering medium. We show that entangled states can be created by multiple-scattering and that quantum interference survives disorder averaging....

  4. Transmutation prospect of long-lived nuclear waste induced by high-charge electron beam from laser plasma accelerator

    Science.gov (United States)

    Wang, X. L.; Xu, Z. Y.; Luo, W.; Lu, H. Y.; Zhu, Z. C.; Yan, X. Q.

    2017-09-01

    Photo-transmutation of long-lived nuclear waste induced by a high-charge relativistic electron beam (e-beam) from a laser plasma accelerator is demonstrated. A collimated relativistic e-beam with a high charge of approximately 100 nC is produced from high-intensity laser interaction with near-critical-density (NCD) plasma. Such e-beam impinges on a high-Z convertor and then radiates energetic bremsstrahlung photons with flux approaching 1011 per laser shot. Taking a long-lived radionuclide 126Sn as an example, the resulting transmutation reaction yield is the order of 109 per laser shot, which is two orders of magnitude higher than obtained from previous studies. It is found that at lower densities, a tightly focused laser irradiating relatively longer NCD plasmas can effectively enhance the transmutation efficiency. Furthermore, the photo-transmutation is generalized by considering mixed-nuclide waste samples, which suggests that the laser-accelerated high-charge e-beam could be an efficient tool to transmute long-lived nuclear waste.

  5. Single Bunch Electron Cloud Effects in the NLC Beam Delivery System(LCC-0126)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D

    2003-12-08

    A positron beam passing through a linear collider beam delivery beam line is finely focused to desired specifications during collimation and especially in Final Focusing (FFS). Undesired additional focusing is generated by beam-electron cloud interactions, which typically leads to beam size increases at high cloud densities. This paper examines the severity of the electron cloud effects and assesses the critical cloud density.

  6. The effect of laser beam size in a zig-zag collimator on transverse ...

    Indian Academy of Sciences (India)

    The effect of size of a cooling laser beam in a zig-zag atomic beam collimator on transverse cooling of a krypton atomic beam is investigated. The simulation results show that discreteness in the interaction between the cooling laser beam and atomic beam, arising due to finite size and incidence angle of the cooling laser ...

  7. Decursin reduce radio-resistance of hypoxic regions under the proton beam therapy by induced HIF-1α degradation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Myung Hwan; Kim, Kye Ryung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Protons induce cancer-cell apoptosis in vitro and block blood vessel formation in vivo through the generation of reactive oxygen species (ROS). The fact that proton severely inhibits blood vessel development in zebrafish embryos suggests a higher sensitivity of vascular endothelial cells to proton beam. Decursin, a coumarin compound, was originally isolated from Angelica gigas Nakai (Dang Gui). A. gigas root has been traditionally used in Korean folk medicine for the treatment of anemia and other common diseases. In previous reports, decursin was reported to exhibit anti-tumor activity against various cancer cells and to inhibit the activities of the androgen and androgen-receptor (AR) signaling pathway in prostate cancer, induction of cell cycle arrest and apoptosis in various cancer cells, such as prostate, breast, bladder, and colon cancer cells. Decursin also inhibits VEGF-induced angiogenesis through the suppression of the VEGFR-2-signaling pathway. However, the mechanism of decursin mediates change of HIF-1α activities is not clear. In this research, we identified regulations of the HIF-1α and the anti-angiogenesis effects of decursin in proton-beam-irradiated human lung cancer, prostate cancer and Hepatic cancer cells. We investigated the underlying mechanisms of positive effects of protonbeam-induced anti-angiogenesis. Our data indicate that the groups co-treated with decursin and a proton-beam had significant reduced HIF-1α activity compared with the groups treated with only a proton beam under the hypoxic condition caused by DFX(desferrioxamine). Decursin was found to induced HIF-1α degradation. Therefore, we suggest that decursin may be a potential candidate for use as a sensitizer for proton-beaminduced cell apoptosis. Here we have shown that decursin successfully reduced HIF-1α stability under hypoxic condition by induced desferrioxamine. We showed novel candidates for anti-angiogenic compound, decursin, leading to complete inhibition of radio

  8. Ion beam induced epitaxy in Ge- and B- coimplanted silicon

    International Nuclear Information System (INIS)

    Hayashi, N.; Hasegawa, M.; Tanoue, H.; Takahashi, H.; Shimoyama, K.; Kuriyama, K.

    1992-01-01

    The epitaxial regrowth of amorphous surface layers in and Si substrate has been studied under irradiation with 400 keV Ar + ions at the temperature range from 300 to 435degC. The amorphous layers were obtained by Ge + implantation, followed by B + implantation. The ion beam assisted epitaxy was found to be sensitive to both the substrate orientation and the implanted Ge concentration, and the layer-by-layer epitaxial regrowth seemed to be precluded in Si layers with high doses of Ge implants, e.g., 2.5 x 10 15 ions/cm 2 . Electrical activation of implanted dopant B was also measured in the recrystallized Si layer. (author)

  9. Chemically Induced Phase Transformation in Austenite by Focused Ion Beam

    Science.gov (United States)

    Basa, Adina; Thaulow, Christian; Barnoush, Afrooz

    2014-03-01

    A highly stable austenite phase in a super duplex stainless steel was subjected to a combination of different gallium ion doses at different acceleration voltages. It was shown that contrary to what is expected, an austenite to ferrite phase transformation occurred within the focused ion beam (FIB) milled regions. Chemical analysis of the FIB milled region proved that the gallium implantation preceded the FIB milling. High resolution electron backscatter diffraction analysis also showed that the phase transformation was not followed by the typical shear and plastic deformation expected from the martensitic transformation. On the basis of these observations, it was concluded that the change in the chemical composition of the austenite and the local increase in gallium, which is a ferrite stabilizer, results in the local selective transformation of austenite to ferrite.

  10. Experiments on the margin of beam induced quenches a superconducting quadrupole magnet in the LHC

    CERN Document Server

    Bracco, C; Bednarek, M J; Nebot Del Busto, E; Goddard, B; Holzer, E B; Nordt, A; Sapinski, M; Schmidt, R; Solfaroli Camillocci, M; Zerlauth, M

    2012-01-01

    Protection of LHC equipment relies on a complex system of collimators to capture injected and circulating beam in case of LHC kicker magnet failures. However, for specific failures of the injection kickers, the beam can graze the injection protection collimators and induce quenches of downstream superconducting magnets. This occurred twice during 2011 operation and cannot be excluded during future operation. Tests were performed during Machine Development periods of the LHC to assess the quench margin of the quadrupole located just downstream of the last injection protection collimator in point 8. In addition to the existing Quench Protection System, a special monitoring instrumentation was installed at this magnet to detect any resistance increase below the quench limit. The correlation between the magnet and Beam Loss Monitor signals was analysed for different beam intensities and magnet currents. The results of the experiments are presented.

  11. RF Wire Compensator of Long-Range Beam-Beam Effects

    CERN Document Server

    Dorda, U; Kroyer, T; Zimmermann, F

    2008-01-01

    The dynamic aperture of the proton beam circulating in the Large Hadron Collider (LHC) is expected to be limited by up to 120 long-range beam-beam encounters. In order to perfectly compensate the LHC long-range beambeam effect for nominal as well as for so-called "PACMAN" bunches, i.e. bunches at the start or end of a bunch train, the strength of a wire compensator should be adjusted for each bunch individually. Here an RF-based compensator is proposed as a practical solution for the PACMAN compensation. We show that this approach also allows relaxing the power and precision requirements compared with those of a pulsed DC device, to a level within the state-of-the-art of RF technology. Furthermore it permits the use of a passive circulator in the tunnel close to the beam and thus a significant reduction of the transmission line length and of the associated multiple reflections. Simulations of dynamic aperture and emittance growth, issues related to RF phase noise, and first experimental results from laborator...

  12. Simulating the Wire Compensation of LHC Long-Range Beam-beam Effects.

    CERN Document Server

    Rijoff, T

    2012-01-01

    The performance of the Large Hadron Collider (LHC) and its minimum crossing angle are limited by long-range beam-beam collisions. Wire compensators can mitigate part of the long-range effects. We perform simulations to explore the efficiency of the compensation at possible wire locations by examining the tune footprint and the dynamic aperture. Starting from the weak-strong simulation code BBTrack we developed a new Lyapunov calculation tool, which seems to better diagnose regular or chaotic particle behavior. We also developed faster ways to execute the simulation and the post-processing. These modifications have allowed us to study different wire positions (longitudinal and transverse), varying wire currents, several wire shapes, and a range of beam-beam crossing angles, in view of a prototype wire installation in the LHC foreseen for 2014/15. Our simulations demonstrate that the wire can provide a good compensation, including for reduced crossing angle. Among the benefits of an LHC wire compensator are a b...

  13. The effect of aberrated recording beams on reflecting Bragg gratings

    Science.gov (United States)

    SeGall, Marc; Ott, Daniel; Divliansky, Ivan; Glebov, Leonid B.

    2013-03-01

    The effect of aberrations present in the recording beams of a holographic setup is discussed regarding the period and spectral response of a reflecting volume Bragg grating. Imperfect recording beams result in spatially varying resonant wavelengths and the side lobes of the spectrum are washed out. Asymmetrical spectra, spectral broadening, and a reduction in peak diffraction efficiency may also be present, though these effects are less significant for gratings with wider spectral widths. Reflecting Bragg gratings (RBGs) are used as elements in a variety of applications including spectral beam combining1,2, mode locking3,4, longitudinal and transverse mode selection in lasers5,6, and sensing7,8. For applications requiring narrow spectral selectivity9, or large apertures10, these gratings must have a uniform period throughout the length of the recording medium, which may be on the order of millimeters. However, when using typical recording techniques such as two-beam interference for large aperture gratings and phase-mask recording of fiber gratings, aberrations from the optical elements in the system result in an imperfect grating structure11-13. In this paper we consider the effects of aberrations on large aperture gratings recorded in thick media using the two-beam interference technique. Previous works in analyzing the effects of aberrations have considered the effects of aberrations in a single recording plane where the beams perfectly overlap. Such an approach is valid for thin media (on the order of tens of microns), but for thick recording media (on the order of several millimeters) there will be a significant shift in the positions of the beams relative to each other as they traverse the recording medium. Therefore, the fringe pattern produced will not be constant throughout the grating if one or both beams have a non-uniform wavefront. Such non-uniform gratings may have a wider spectral width, a shifted resonant wavelength, or other problems. It is

  14. Modeling of Low Frequency MHD Induced Beam Ion Transport In NSTX

    International Nuclear Information System (INIS)

    Gorelenkov, N.N.; Medley, S.S.

    2004-01-01

    Beam ion transport in the presence of low frequency MHD activity in National Spherical Tokamak Experiment (NSTX) plasma is modeled numerically and analyzed theoretically in order to understand basic underlying physical mechanisms responsible for the observed fast ion redistribution and losses. Numerical modeling of the beam ions flux into the NPA in NSTX shows that after the onset of low frequency MHD activity high energy part of beam ion distribution, E b > 40keV, is redistributed radially due to stochastic diffusion. Such diffusion is caused by high order harmonics of the transit frequency resonance overlap in the phase space. Large drift orbit radial width induces such high order resonances. Characteristic confinement time is deduced from the measured NPA energy spectrum and is typically ∼ 4msec. Considered MHD activity may induce losses on the order of 10% at the internal magnetic field perturbation (delta)B/B = Ο (10 -3 ), which is comparable to the prompt orbit losses

  15. Effects of electron beam irradiation on fluoroelastomer properties

    International Nuclear Information System (INIS)

    Giovedi, Claudia; Leitao Junior, Claudio B.; Carvalho, Alvaro A.S.; Pino, Eddy S.; Machado, Luci D.B.

    2005-01-01

    Fluoroelastomer is a polymer usually used as a sealing material due to some excellent properties comparing to other elastomers, such as good resistance to high temperatures and to the attack of chemical substances. The fluoroelastomer used in this work was a commercial product obtained from two monomers, vinylidene and hexafluoropropylene, containing also carbon black and inorganic fillers. The aim of this work was to study the effect of the ionizing radiation of electron beam (EB) on the tensile, hardness and thermal properties of this sealing material obtained by a conventional curing process. The overall doses applied were 10, 25, 50, 75, 100, 125, 150, 175, 200 and 250 kGy. Tension tests showed that the tensile stress at break increases 34 % in the range of radiation dose applied. On the other hand, the total strain decreases considerably, from 347 % to 109 %, with the increase of the radiation dose. Hardness Shore A values increase 15 % in the range of radiation dose studied. Thermogravimetric curves showed that there are no considerable variations on the onset temperatures for all samples in the range of radiation doses applied. These results indicate that EB radiation produces modifications on the fluoroelastomer mechanical properties, but without promoting considerable chain scission. The modifications on the mechanical properties can be related to a better adhesion, induced by radiation, between the fluoroelastomer and the fillers. (author)

  16. Vibration induced sliding: theory and experiment for a beam with a spring-loaded mass

    DEFF Research Database (Denmark)

    Miranda, Erik; Thomsen, Jon Juel

    1998-01-01

    , and contributes to a further understanding of this nonlinear phenomenon. A mathematical model is set up to describe vibration induced sliding for a base-excited cantilever beam with a spring-loaded pointmass. Approximations simplify the model into two nonlinear ordinary differential equations, describing motions...

  17. Crosslinking of oriented polyethylene by electron beam radiation. Influence of morphology induced by drawing

    International Nuclear Information System (INIS)

    Aerle, N.A.J.M. van; Crevecoeur, G.; Lemstra, P.J.

    1988-01-01

    The influence of drawing on the crosslinking efficiency for electron beam radiation is reported for solution-crystallized ultra-high molecular weight polyethylene. A maximum in crosslinking efficiency is found at a draw ratio of approximately five, indicating an optimum morphology for inducing crosslinks during the hot-drawing process. (author)

  18. Beam-induced radiation in the compact muon solenoid tracker at the ...

    Indian Academy of Sciences (India)

    The intense radiation environment at the Large Hadron Collider, CERN at a design energy of. √ s = 14 TeV ... situated only a few centimeters from the interaction point, are most vulnerable to beam-induced radiation. .... fluences beyond 1 × 1015 cm−2 for minimum ionizing protons [6]. So we expect the pixel detectors to ...

  19. Diffraction-free, self-reconstructing Bessel beam generation using thermal nonlinear optical effect

    Science.gov (United States)

    Zhang, Q.; Cheng, X. M.; Chen, H. W.; He, B.; Ren, Z. Y.; Zhang, Y.; Bai, J. T.

    2017-10-01

    We propose a method to generate a Bessel beam using cross-phase modulation based on the thermal nonlinear optical effect. The thermal nonlinear medium is shown to have the ability to vary a Gaussian beam (probe beam) into a hollow beam when the medium is illuminated with a counter-propagating Gaussian beam (pump beam). It is demonstrated that this method has no restriction to the probe beam wavelength. Moreover, the generated Bessel beam exhibits superior non-diffraction properties during propagation and self-healing after encountering an obstruction on the beam path. The parameters of the beam can be easily adjusted by both the pump beam power and the sample concentration. The merits of variable parameters, no requirement for input beam wavelengths, simple setup, and low-cost would make this method significant in a variety of applications, especially in those areas where the parameters of the Bessel beam need to be easily adjusted without changing the setup.

  20. Effects of Ion Beam Irradiation on Nanoscale InOx Cooper-Pair Insulators

    Directory of Open Access Journals (Sweden)

    Srdjan Milosavljević

    2013-01-01

    Full Text Available This paper examines the effects of irradiating indium oxide films of nanoscale thickness by ion beams, when these films are in the Cooper-pair insulator state. Radiation effects are predicted on the basis of Monte Carlo simulations of ion transport. Results of numerical experiments are interpreted within the theoretical model of a Cooper-pair insulator. The study suggests that radiation-induced changes in InOx films exposed to ion beams could significantly alter their current-voltage characteristics and that a transition to a metallic state is possible, due to radiation-induced perturbation of the fine-tuned granular structure. Furthermore, incident and displaced ions can break up enough Cooper pairs in InOx films to cause dissolution of this specific insulating state.

  1. Moessbauer Effect applications using intense radioactive ion beams

    International Nuclear Information System (INIS)

    Taylor, R.D.

    1990-01-01

    The Moessbauer Effect is reviewed as a promising tool for a number of new solid state studies when used in combination with radioactive beam/implantation facilities. The usual Moessbauer Effect involves long-lived radioactive parents (days to years) that populate low-lying nuclear excited states that subsequently decay to the ground state. Resonant emission/absorption of recoil-free gamma rays from these states provide information on a number of properties of the host materials. Radioactive ion beams (RIB) produced on-line allow new Moessbauer nuclei to be studied where there is no suitable parent. The technique allows useful sources to be made having extremely low local concentrations. The ability to separate the beams in both Z and A should provide high specific activity ''conventional'' sources, a feature important in some applications such as Moessbauer studies in diamond anvil high pressure cells. Exotic chemistry is proposed using RIB and certain Krypton and Xenon Moessbauer isotopes

  2. Thermal field induced by intense pulsed ion beam and its possible application in thermal diffusivity measurement

    Science.gov (United States)

    Yu, Xiao; Huang, Wanying; Shen, Jie; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Liang, Guoying; Zhang, Xiaofu; Zhang, Gaolong; Yan, Sha; Remnev, Gennady Efimovich; Le, Xiaoyun

    2017-10-01

    As a type of flash heating source, intense pulsed ion beam (IPIB) can induce strong thermal effect in the near-surface region of the target. Compared with laser, the energy deposition efficiency of IPIB is significantly higher and is less dependent on the optical properties of the target. The range of ions in matter can be changed more flexibly by adjusting the accelerating voltage. This makes IPIB an ideal candidate for pulsed heating source of the flash method for the measurement of thermal diffusivity of materials. In present work, numerical verification of flash method with IPIB generated by magnetically insulated diode (MID) was carried out. By exploring the features of the induced thermal field, it is demonstrated that IPIB composed of protons and carbon ions with energy of several hundred keV and cross-sectional energy density of several J/cm2 can be used for the measurement of thermal diffusivity with flash method, and the principles of optimization in experimental parameters are discussed.

  3. Electron beam induced cationic polymerization of epoxy resins. Dependence of Tg on conversion

    International Nuclear Information System (INIS)

    Degrand, H.; Cazaux, F.; Coqueret, X.

    2002-01-01

    Complete text of publication follows. The high-energy radiation curing of monomer blends polymerizing by a free radical or by a cationic mechanism receives increasing attention in the perspective of high performance composite materials. In the present work, we have focused our attention on epoxy formulations as models of the matrices polymerizing by a cationic mechanism that could be used in fiber-reinforced composites for aerospace applications. We have examined the progress of the electron beam (EB) induced polymerization of diglycidylether of bisphenol A (DGEBA) in the presence of a diaryliodonium salt (DAIS) by FTIR spectroscopy and by dynamic mechanical thermal analysis (DMA). The obtained results allow to draw the gradual increase of the temperature for the network thermomechanical transition (T a , associated with the glass transition temperature T g ) over a broad range of conversion (p) and reveal a peculiar behavior at high conversion. In this domain (p > 0.90), the material's T g is shown to decrease when conversion approaches unity. Moreover, the post-irradiation thermal treatment of the materials, that generally yields effective 'dark curing', appears to induce a decrease of T g , with an amplitude correlated with the amount of DAIS in the formulation. Owing to the particular nature of the propagating centers in cationic polymerisation, the thermal relaxation of ionic clusters trapped in the glassy matrix can be reasonably invoked as a possible cause for this behavior

  4. Room Temperature Ion-Beam-Induced Recrystallization and Large Scale Nanopatterning.

    Science.gov (United States)

    Satpati, Biswarup; Ghosh, Tanmay

    2015-02-01

    We have studied ion-induced effects in the near-surface region of two eutectic systems. Gold and Silver nanodots on Silicon (100) substrate were prepared by thermal evaporation under high vacuum condition at room temperature (RT) and irradiated with 1.5 MeV Au2+ ions at flux ~1.25 x 10(11) ions cm-2 s-1 also at RT. These samples were characterized using cross-sectional transmission electron microscopy (XTEM) and associated techniques. We have observed that gold act as catalysis in the recrystallization process of ion-beam-induced amorphous Si at room temperature and also large mass transport up to a distance of about 60 nm into the substrate. Mass transport is much beyond the size (~ 6-20 nm) of these Au nanodots. Ag nanoparticles with diameter 15-45 nm are half-way embedded into the Si substrate and does not stimulate in recrystallization. In case of Au nanoparticles upon ion irradiation, mixed phase formed only when the local composition and transient temperature during irradiation is sufficient to cause mixing in accordance with the Au-Si stable phase diagram. Spectroscopic imaging in the scanning TEM using spatially resolved electron energy loss spectroscopy provides one of the few ways to measure the real-space nanoscale mixing.

  5. Internal target effects in ion storage rings with beam cooling

    International Nuclear Information System (INIS)

    Gostishchev, Vitaly

    2008-06-01

    The accurate description of internal target effects is important for the prediction of operation conditions which are required for experiments in the planned storage rings of the FAIR facility. The BETACOOL code developed by the Dubna group has been used to evaluate beam dynamics in ion storage rings, where electron cooling in combination with an internal target is applied. Systematic benchmarking experiments of this code were carried out at the ESR storage ring at GSI. A mode with vanishing dispersion in the target position was applied to evaluate the influence of the dispersion function on the parameters when the target is heating the beam. The influence of the internal target on the beam parameters is demonstrated in the present work. A comparison of experimental results with simple models describing the energy loss of the beam particles in the target as well as with more sophisticated simulations with the BETACOOL code is given. In order to study the conditions which can be achieved in the proposed experiments the simulation results were quantitatively compared with experimental results and simulations for the ESR. The results of this comparison are discussed in the present thesis. BETACOOL simulations of target effects were performed for the NESR and the HESR of the future FAIR facility in order to predict the beam parameters for the planned experiments. (orig.)

  6. Beam-beam interaction and pacman effects in the SSC with momentum oscillation

    International Nuclear Information System (INIS)

    Mahale, N.K.; Ohnuma, S.

    1989-01-01

    In order to find the combined effects of beam-beam interaction (head-on and long-range) and random nonlinear multipoles in dipole magnets, the transverse oscillations of ''regular'' as well as ''pacman'' particles are traced for 256 synchrotron oscillation periods (corresponding to 135K revolutions) in the proposed SSC. Results obtained in this study do not show any obvious reduction of dynamic or linear apertures for pacman particles when compared with regular particles for (Δp/p) = 0. There are some indications of possible sudden or gradual increases in the oscillation amplitude, for pacman as well as regular particles, when the amplitude of momentum oscillation is as large as 3σ. 4 refs., 7 figs

  7. Electron beam exposure mechanisms in hydrogen silsesquioxane investigated by vibrational spectroscopy and in-situ electron beam induced desorption

    Energy Technology Data Exchange (ETDEWEB)

    Olynick, D.L.; Cord, B.; Schipotinin, A.; Ogletree, D.F.; Schuck, P.J.

    2009-11-13

    Hydrogen Silsesquioxane (HSQ) is used as a high-resolution resist with resolution down below 10nm half-pitch. This material or materials with related functionalities could have widespread impact in nanolithography and nanoscience applications if the exposure mechanism was understood and instabilities controlled. Here we have directly investigated the exposure mechanism using vibrational spectroscopy (both Raman and Fourier transform Infrared) and electron beam desorption spectrocscopy (EBDS). In the non-networked HSQ system, silicon atoms sit at the corners of a cubic structure. Each silicon is bonded to a hydrogen atom and bridges 3 oxygen atoms (formula: HSiO3/2). For the first time, we have shown, via changes in the Si-H2 peak at ~;;2200 cm -1 in the Raman spectra and the release of SiHx products in EBID, that electron-bam exposed materials crosslinks via a redistribution reaction. In addition, we observe the release of significantly more H2 than SiH2 during EBID, which is indicative of additional reaction mechanisms. Additionally, we compare the behavior of HSQ in response to both thermal and electron-beam induced reactions.

  8. Ion beam-induced topographical and chemical modification on the poly(styrene-co-allyl alcohol) and its effect on the molecular interaction between the modified surface and liquid crystals

    International Nuclear Information System (INIS)

    Jeong, Hae-Chang; Park, Hong-Gyu; Lee, Ju Hwan; Jang, Sang Bok; Oh, Byeong-Yun; Seo, Dae-Shik

    2016-01-01

    We demonstrated uniform liquid crystal (LC) alignment on ion beam (IB)-irradiated poly(styrene-co-allyl alcohol) by modifying the chemical bonding on the surface. An IB-irradiated copolymer was used for the alignment layer. We used physico-chemical analysis to determine the IB-irradiated surface modification and LC alignment mechanism on the surface. During IB treatment on poly(styrene-co-allyl alcohol), IB irradiation induces breaking of chemical bonds on the surface to give rise to new bonds with oxygen atoms. This causes a strong Van der Waals interaction between LCs and the modified surface, thereby resulting in uniform LC alignment. The results of contact angle (CA) studies of the copolymer support the chemical bonding changes that were investigated by XPS. We achieved uniform homogeneous LC alignment and obtained stable electro-optical performance by controlling the IB energy. Therefore, the LC cells with IB-irradiated poly(styrene-co-allyl alcohol) exhibited a good potential for alternative alignment of layers in LC applications.

  9. Ion beam-induced topographical and chemical modification on the poly(styrene-co-allyl alcohol) and its effect on the molecular interaction between the modified surface and liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae-Chang [Information Display Device Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Park, Hong-Gyu [School of Electrical, Electronic & Control Engineering, Changwon National University, 20 Changwondaehak-ro, Uichang-gu, Changwon-si, Gyeongsangnam-do, 51140 (Korea, Republic of); Lee, Ju Hwan; Jang, Sang Bok [Information Display Device Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Oh, Byeong-Yun [ZeSHTech Co., Ltd., Business Incubator, Gwangju Institute of Science and Technology, 123, Cheomdangwagi-ro, Buk-gu, Gwangju, 500-712 (Korea, Republic of); Seo, Dae-Shik, E-mail: dsseo@yonsei.ac.kr [Information Display Device Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of)

    2016-10-01

    We demonstrated uniform liquid crystal (LC) alignment on ion beam (IB)-irradiated poly(styrene-co-allyl alcohol) by modifying the chemical bonding on the surface. An IB-irradiated copolymer was used for the alignment layer. We used physico-chemical analysis to determine the IB-irradiated surface modification and LC alignment mechanism on the surface. During IB treatment on poly(styrene-co-allyl alcohol), IB irradiation induces breaking of chemical bonds on the surface to give rise to new bonds with oxygen atoms. This causes a strong Van der Waals interaction between LCs and the modified surface, thereby resulting in uniform LC alignment. The results of contact angle (CA) studies of the copolymer support the chemical bonding changes that were investigated by XPS. We achieved uniform homogeneous LC alignment and obtained stable electro-optical performance by controlling the IB energy. Therefore, the LC cells with IB-irradiated poly(styrene-co-allyl alcohol) exhibited a good potential for alternative alignment of layers in LC applications.

  10. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    Energy Technology Data Exchange (ETDEWEB)

    Kurebayashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Sakurai, H., E-mail: sakurail@sci.kj.yamagata-u.ac.jp [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Takahashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Doshita, N. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kikuchi, S. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Tokanai, F. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Horiuchi, K. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Tajima, Y. [Institute of Arts and Sciences, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Oe, T. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sato, T. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Gunji, S. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Inui, E. [Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kondo, K. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Iwata, N. [Dept. of Earth and Environmental Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sasaki, N. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Matsuzaki, H. [Micro Analysis Laboratory, Tandem accelerator (MALT), The University Museum, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Kunieda, S. [Nuclear Data Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun 319-1195, Ibaraki (Japan)

    2015-11-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10{sup –9} PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×10{sup 13} was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al.

  11. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    International Nuclear Information System (INIS)

    Kurebayashi, Y.; Sakurai, H.; Takahashi, Y.; Doshita, N.; Kikuchi, S.; Tokanai, F.; Horiuchi, K.; Tajima, Y.; Oe, T.; Sato, T.; Gunji, S.; Inui, E.; Kondo, K.; Iwata, N.; Sasaki, N.; Matsuzaki, H.; Kunieda, S.

    2015-01-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10 –9 PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×10 13 was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al

  12. Measurements of effective total macroscopic cross sections and effective energy of continuum beam

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hisao [Rikkyo Univ., Yokosuka, Kanagawa (Japan). Inst. for Atomic Energy

    1998-03-01

    Two practically useful quantities are introduced in this study to characterize a continuum neutron beam and to describe transmission phenomena of the beam in field of quantitative neutron radiography: an effective energy instead of a peak energy or a mean energy of the spectrum and an effective total macroscopic (ETM) cross section instead of a total macroscopic (TM) cross section defined at the monochromatic energy. The effective energy was evaluated by means of energy dependence of ETM cross section. To realize the method a beam quality indicator (BQI) has been proposed recently. Several effective energies were measured for non-filtered, filtered neutron beams, and outputs of neutron guide tubes in world by the BQI. A thermal neutron beam and three beams modulated by Pb filters with different thicknesses are studied to measure ETM cross sections for various materials and summarized in a table. Validity of the effective energy determined by the BQI is discussed relating with ETM cross sections of materials. (author)

  13. Investigation of effect of electron beam on various polyethylene blends

    CERN Document Server

    Morshedian, J

    2003-01-01

    With regards to the expanding usage of electron beams irradiation in polymer industries such as sterilization of polymeric disposable medical products; cable manufacturing; pipes, heat shrinkable materials, etc. In this project the effect of electron beam on polyethylene used in manufacturing of pipe and heat shrinkable products was studied. Results showed that by increasing the applied dose on samples; the crosslink density would increase and polymers with tertiary carbon atoms in their backbone structure tend to crosslink more readily. The melting temperature and crystallinity percent decreased and degradation temperature increased. Density in low doses decreased and in high doses increased.

  14. Stochastic effects in real and simulated charged particle beams

    Directory of Open Access Journals (Sweden)

    Jürgen Struckmeier

    2000-03-01

    Full Text Available The Vlasov equation embodies the smooth field approximation of the self-consistent equation of motion for charged particle beams. This framework is fundamentally altered if we include the fluctuating forces that originate from the actual charge granularity. We thereby perform the transition from a reversible description to a statistical mechanics description covering also the irreversible aspects of beam dynamics. Taking into account contributions from fluctuating forces is mandatory if we want to describe effects such as intrabeam scattering or temperature balancing within beams. Furthermore, the appearance of “discreteness errors” in computer simulations of beams can be modeled as “exact” beam dynamics that are being modified by fluctuating “error forces.” It will be shown that the related emittance increase depends on two distinct quantities: the magnitude of the fluctuating forces embodied in a friction coefficient, γ, and the correlation time dependent average temperature anisotropy. These analytical results are verified by various computer simulations.

  15. Effects of ion beam irradiation on semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  16. Size effect in self consolidating concrete beams with and without ...

    Indian Academy of Sciences (India)

    Abstract. The aim of this study is to obtain the fracture characteristics of low and medium compressive strength self consolidating concrete (SCC) for notched and un-notched plain concrete beams by using work of fracture GF and size effect model Gf methods and comparing them with those of normal concrete and high.

  17. LTRACK: Beam-transport calculation including wakefield effects

    International Nuclear Information System (INIS)

    Chan, K.C.D.; Cooper, R.K.

    1988-01-01

    LTRACK is a first-order beam-transport code that includes wakefield effects up to quadrupole modes. This paper will introduce the readers to this computer code by describing the history, the method of calculations, and a brief summary of the input/output information. Future plans for the code will also be described

  18. Effect of acid corrosion on crack propagation of concrete beams

    Indian Academy of Sciences (India)

    HU SHAOWEI

    e-mail: chenqiyong@outlook.com. MS received 30 November 2016; revised 22 May 2017; accepted 16 June 2017; published online 10 March 2018. Abstract. The effect of acid corrosion on crack propagation of concrete beams was theoretically studied by the method of crack extension resistance curve. Based on this ...

  19. Correction of beam-beam effects in luminosity measurement at ILC

    CERN Document Server

    Lukic, S

    2015-01-01

    Three methods for handling beam-beam effects in luminosity measurement at ILC are tested and evaluated in this work. The first method represents an optimization of the LEPtype asymmetric selection cuts that reduce the counting biases. The second method uses the experimentally reconstructed shape of the √ s ′ spectrum to determine the Beamstrahlung component of the bias. The last, recently proposed, collision-frame method relies on the reconstruction of the collision-frame velocity to define the selection function in the collision frame both in experiment and in theory. Thus the luminosity expression is insensitive to the difference between the CM frame of the collision and the lab frame. The collision-frame method is independent of the knowledge of the beam parameters, and it allows an accurate reconstruction of the luminosity spectrum above 80% of the nominal CM energy. However, it gives no precise infromation about luminosity below 80% of the nominal CM energy. The compatibility of diverse selection cut...

  20. The powerful pulsed electron beam effect on the metallic surfaces

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Yuferov, V.B.; Kosik, N.A.; Druj, O.S.; Skibenko, E.I.

    2001-01-01

    Experimental results of the influence of powerful pulsed electron beams on the surface structure,hardness and corrosion resistance of the Cr18ni10ti steel are presented. The experiments were carried out in the powerful electron accelerators of directional effect VGIK-1 and DIN-2K with an energy up to approx 300 KeV and a power density of 10 9 - 10 11 W/cm 2 for micro- and nanosecond range. The essential influence of the irradiation power density on the material structure was established. Pulsed powerful beam action on metallic surface leads to surface melting,modification of the structure and structure-dependent material properties. The gas emission and mass-spectrometer analysis of the beam-surface interaction were defined

  1. Selected immobilization of individual nanoparticles by spot-exposure electron-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Burbridge, Daniel J; Crampin, Simon; Gordeev, Sergey N [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Viau, Guillaume [Departement de Genie Physique, INSA de Toulouse, 135 avenue de Rangueil, 31077 Toulouse Cedex 4 (France)

    2010-01-29

    The use of spot-exposure electron-beam-induced deposition (EBID) to immobilize targeted nanoparticles on a substrate is demonstrated, and investigated using experiment and simulation. Nanoparticles are secured in place through the build-up of carbonaceous material that forms in the region between a particle and substrate when an energetic electron beam is focused onto the particle and projected through to the substrate. Material build-up directly affects the strength of adhesion to the surface, and can be controlled through electron dosage and beam energy. By selectively immobilizing specific particles within surface agglomerations and removing the excess, we illustrate the potential for spot-exposure EBID as a new technique for nanofabrication.

  2. Inverse Faraday effect with plasmon beams

    International Nuclear Information System (INIS)

    Ali, S; Mendonca, J T

    2011-01-01

    The angular momentum conservation equation is considered for an electron gas, in the presence of Laguerre-Gaussian (LG) plasmons propagating along the z-axis. The LG plasmons carry a finite orbital angular momentum despite longitudinal nature, which can be partly transfered to the electrons. For short timescales, such that ion motion can be neglected, plasmons primarily interact with the electrons, creating an azimuthal electric field and generating an axial magnetic field. This effect can be called an inverse Faraday effect due to plasmons. Numerically, it is found that the magnitude of the magnetic field enhances with the plasmon density or with the energy of the electron plasma waves. A comparison of the magnitudes of the axial magnetic field is made for the inverse Faraday effect excited by both plasmons and transverse photons.

  3. Effects of beam-beam collisions on storage-ring performance - a pedagogical review

    International Nuclear Information System (INIS)

    Schonfeld, J.F.

    1983-01-01

    This paper presents a survey of the experimental and theoretical literature on colliding-beam effects in both leptonic and hadronic storage rings. For the most part, this literature is rather technical and, to the novice, both obscurely written and hard to locate. Although there have already been several symposia on the subject, as well as a number of reviews for specialists there has up till now been no unified and pedagogical exposition. The present work represents an attempt to fill this gap. The material is grouped into four major areas: observational phenomenology, computer simulation, mathematical background, and theoretical models. 113 references, 36 figures

  4. Decomposition of organic pollutants in industrial Effluent induced by advanced oxidation process with Electron beam irradiation

    International Nuclear Information System (INIS)

    Duarte, C.L.; Sampa, M.H.O.; Rela, P.R.; Oikawa, H.; Silveira, C.G.

    2001-01-01

    Advanced Oxidation Process (AOP) by electron beam irradiation induce the decomposition of pollutants in industrial effluent. Experiments were conducted using a Radiation Dynamics Electron Beam Accelerator with 1.5 MeV energy and 37 Kew power. Experiments were conducted using samples from a Governmental Wastewater Treatment Plant (WTP) that receives about 20% of industrial wastewater, with the objective of use the electrons beam technology to destroy the refractory organic pollutants. Samples from WTP main Industrial Receiver Unit influent (IRU), Coarse Bar Screens effluent (CBS), Medium Bar Screens effluent (MBS), Primary Sedimentation effluent (PS) and Final Effluent (FE), were collected and irradiated in the electron beam accelerator in a batch system. The delivered doses were 5.0kGy, 10.0kGy and 20.0kGy. The electron beam irradiation showed be efficient on destroying the organic compounds delivered in these effluents mainly chloroform, dichloroethane, methyl isobutyl ketone, benzene, toluene, xylene, phenol. The necessary dose to remove 90% of the most organic compounds from industry effluent was 20 kGy. The removal of organic compounds from this complex mixture were described by the destruction G value (Gd) that were obtained for those compounds in different initial concentration and compared with literature

  5. Detection of Ground Motion effects on the beam trajectory at ATF2

    CERN Document Server

    Renier, Y; Tomas, R; Schulte, D

    2012-01-01

    The ATF2 experiment is currently demonstrating the feasibility of the beam delivery system for the future linear collider. The orbit feedback is very critical to obtain the nanometer vertical beam size at the interaction point and in the case of CLIC, ground motion effects on the beam must be corrected. In this respect, as a proof of principle of a ground motion feed forward, the ground motion effects on the beam trajectory are extracted from the beam position monitor readings.

  6. Toward sensitive graphene nanoribbon-nanopore devices by preventing electron beam-induced damage.

    Science.gov (United States)

    Puster, Matthew; Rodríguez-Manzo, Julio A; Balan, Adrian; Drndić, Marija

    2013-12-23

    Graphene-based nanopore devices are promising candidates for next-generation DNA sequencing. Here we fabricated graphene nanoribbon-nanopore (GNR-NP) sensors for DNA detection. Nanopores with diameters in the range 2-10 nm were formed at the edge or in the center of graphene nanoribbons (GNRs), with widths between 20 and 250 nm and lengths of 600 nm, on 40 nm thick silicon nitride (SiN(x)) membranes. GNR conductance was monitored in situ during electron irradiation-induced nanopore formation inside a transmission electron microscope (TEM) operating at 200 kV. We show that GNR resistance increases linearly with electron dose and that GNR conductance and mobility decrease by a factor of 10 or more when GNRs are imaged at relatively high magnification with a broad beam prior to making a nanopore. By operating the TEM in scanning TEM (STEM) mode, in which the position of the converged electron beam can be controlled with high spatial precision via automated feedback, we were able to prevent electron beam-induced damage and make nanopores in highly conducting GNR sensors. This method minimizes the exposure of the GNRs to the beam before and during nanopore formation. The resulting GNRs with unchanged resistances after nanopore formation can sustain microampere currents at low voltages (∼50 mV) in buffered electrolyte solution and exhibit high sensitivity, with a large relative change of resistance upon changes of gate voltage, similar to pristine GNRs without nanopores.

  7. Electron beam irradiation effects on xanthan gum, rheological aspects

    International Nuclear Information System (INIS)

    Mastro, N.L. del; Vieira, F.F.

    2003-01-01

    Food ingredients to be used for food processing should be decontaminated in order to prevent food spoilage and food-borne diseases. Xanthan gum is a well-known microbial polysaccharide produced by Xanthomonas campestris used in the hydrocolloid market. This paper describes the application of electron beam (EB) irradiation to xanthan gum as used as ingredient by the food or cosmetics industry in order to establish their radiosensitivity. Viscosity of 1% xanthan gum solutions prepared with the irradiated powder decreased with the increase of the EB irradiation dose. The radiation-induced viscosity detriment of this additive must be considered for practical applications. (author)

  8. Protective role of Carica papaya (Linn.) in electron beam radiation induced hematological and cytogenetic damages in Swiss albino mice

    International Nuclear Information System (INIS)

    Yogish Somayaji, T.; Suchetha Kumari, N.

    2014-01-01

    Carica papaya (Linn.) is known to possess various biomedical applications. It has remarkable antioxidant properties. The main objective of the study was to evaluate the leaf extracts of Carica papaya (Linn.) on hematologic and cytogenetic changes occurring due to irradiation of mice to sub-lethal doses of Electron Beam Radiation (EBR). Analysis of hematological changes occurring due to irradiation of mice to sub-lethal doses of EBR, and the effects of Carica papaya (Linn.) extract on the same. The Assessment of hematopoietic stress by spleen colony forming unit and spleen body weight index. The analysis of cell proliferation and immunomodulation with response to the effects of Carica papaya (Linn.) extract by estimation of IL-6. The estimation of serum total antioxidants, lipid peroxidation and analyzing the activities of enzymes like SOD, ALP, and AST. Male Swiss albino mice were fed orally with papaya aqueous leaf extract for 15 days. They were irradiated with a whole body dose of 6 Gy Electron Beam radiation. The mice were dissected for liver, kidney, bone marrow, spleen and brain. The hematological studies were done using blood cell count in an automated cell counter. The biochemical estimations like urea, creatinine, SGOT, SGPT, Total Protein, Albumin, Bilirubin were done using the serum and homogenates. The total antioxidant capacity, the antioxidant enzymes were estimated. The Interleukin-6 levels were estimated in serum to assess immune modulation. The results show a decrease in the hematological parameters in radiated animals. The papaya treated groups have shown modulation in the hematological parameters. The extract has also reduced the suppression of the bone marrow induced by radiation. The radiation induced liver damage is also reduced in papaya treated groups. The aqueous extract of Carica papaya (Linn.) has shown protective effects in electron beam radiation induced tissue damages in Swiss Albino mice (author)

  9. A three-dimensional relaxation model for calculation of atomic mixing and topography changes induces by ion beams

    International Nuclear Information System (INIS)

    Collins, R.; Perez-Martin, A.M.C.; Dominguez-Vazquez, J.; Jimenez-Rodriguez, J.J.

    1994-01-01

    A simple model for three-dimensional material relaxation associated with atomic mixing is presented. The relaxation of the solid to accommodate the extra effective displacement volume Ω of an implanted or relocated atom is modelled by treating the surrounding solid as an incompressible medium. This leads to a tractable general formalism which can be used to predict implant distribution and changes in surface topography induced by ion beams, both in monatomic and multicomponent targets. The two-component case is discussed in detail. (orig.)

  10. Prestressing effect of cold-drawn short NiTi SMA fibres in steel reinforced mortar beams

    Science.gov (United States)

    Choi, Eunsoo; Kim, Dong Joo; Hwang, Jin-Ha; Kim, Woo Jin

    2016-08-01

    This study investigated the prestressing effect of cold-drawn short NiTi shape memory alloy (SMA) fibres in steel reinforced mortar beams. The SMA fibres were mixed with 1.5% volume content in a mortar matrix with the compressive strength of 50 MPa. The SMA fibres had an average length of 34 mm, and they were manufactured with a dog-bone shape: the diameters of the end- and middle-parts were 1.024 and 1.0 mm, respectively. Twenty mortar beams with the dimensions of 40 mm × 40 mm × 160 mm (B × H × L) were prepared. Two types of tests were conducted. One was to investigate the prestressing effect of the SMA fibres, and the beams with the SMA fibres were heated at the bottom. The other was to assess the bending behaviour of the beams prestressed by the SMA fibres. The SMA fibres induced upward deflection and cracking at the top surface by heating at the bottom; thus, they achieved an obvious prestressing effect. The beams that were prestressed by the SMA fibres did not show a significant difference in bending behaviour from that of the SMA fibre reinforced beams that were not subjected to heating. Stress analysis of the beams indicated that the prestressing effect decreased in relation to the cooling temperature.

  11. Radiomodifying effect of caffeine on mammalian cellular system using gamma radiation and proton beam radiation

    International Nuclear Information System (INIS)

    Samanth, Sneha P.; Yadav, Usha; Shirsath, K.B.; Desai, Utkarsha N.; Chaurasia, Rajesh K.; Bhat, Nagesh N.; Anjaria, K.B.; Sapra, B.K.

    2016-01-01

    Caffeine is a commonly consumed neurostimulant in the world. Reports suggest the radiomodifying effects of caffeine against low Linear Energy Transfer (LET) radiation when administered pre and post irradiation by releasing checkpoint arrest. In the present report, the radioprotective and radiosensitizing ability of caffeine (10μM - 2mM) were studied on Chinese Hamster Ovary (CRO) cell line against low as well as high LET radiation when administered pre, post and continuously during radiation. Effect of caffeine treatment on the genotoxicity induced by gamma and proton beam radiation was assessed by micronucleus assay. Effect of caffeine treatment on clonogenic survival of irradiated cells was also assessed

  12. Electron beam induced modifications in flexible biaxially oriented polyethylene terephthalate sheets: Improved mechanical and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, N. [Accelerator & Pulse Power Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Koiry, S.P. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Singh, A., E-mail: asb_barc@yahoo.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Tillu, A.R. [Accelerator & Pulse Power Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Jha, P.; Samanta, S.; Debnath, A.K. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Aswal, D.K., E-mail: dkaswal@yahoo.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Mondal, R.K. [Radiation Technology Development Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Acharya, S.; Mittal, K.C. [Accelerator & Pulse Power Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India)

    2017-03-01

    In the present work, we have studied the effects of electron beam irradiation (with dose ranging from 2 to 32 kGy) on mechanical and electrical properties of biaxially oriented polyethylene terephthalate (BOPET) sheets. The sol-gel analysis, Fourier transformation infra-red (FTIR), X-ray photoelectron spectroscopy (XPS) characterizations of the irradiated BOPET sheets suggest partial cross-linking of PET chains through the diethylene glycol (DEG). The mechanical properties of BOPET, such as, tensile strength, Young's modulus and electrical resistivity shows improvement with increasing dose and saturate for doses >10 kGy. The improved mechanical properties and high electrical resistivity of electron beam modified BOPET sheets may have additional advantages in applications, such as, packaging materials for food irradiation, medical product sterilization and electronic industries. - Graphical abstract: Irradiation of BOPET by electron beam leads to the formation of diethylene glycol that crosslink's the PET chains, resulting in improved mechanical properties and enhanced electrical resistivity. - Highlights: • BOPET exhibit improved tensile strength/Young's modulus after e-beam exposure. • Electrical resistivity of BOPET increases after e-beam exposure. • Cross-linking of PET chains through diethylene glycol was observed after e-beam exposure.

  13. Effects of ion beam irradiation on size of mutant sector and genetic damage in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Hase, Yoshihiro, E-mail: hase.yoshihiro@qst.go.jp [Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Nozawa, Shigeki [Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Narumi, Issay [Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Gunma 374-0193 (Japan); Oono, Yutaka [Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2017-01-15

    Size of mutant sector and genetic damage were evaluated in Arabidopsis to further our understanding of effective ion beam use in plant mutation breeding. Arabidopsis seeds, heterozygous for the GLABRA1 (GL1) gene (GL1/gl1-1), were irradiated with 15.8 MeV/u neon ions (mean linear energy transfer (LET): 352 keV/μm), 17.3 MeV/u carbon ions (113 keV/μm), or {sup 60}Co gamma rays. The frequency and size of glabrous sectors generated because of inactivation of the GL1 allele were examined. The frequency and overall size of large deletions were evaluated based on the loss of heterozygosity of DNA markers using DNA isolated from glabrous tissue. Irrespective of the radiation properties, plants with mutant sectors were obtained at similar frequencies at the same effective dosage necessary for survival reduction. Ion beams tended to induce larger mutant sectors than gamma rays. The frequency of large deletions (>several kbp) increased as the LET value increased, with chromosome regions larger than 100 kbp lost in most large deletions. The distorted segregation ratio of glabrous plants in the progenies of irradiated GL1/gl1-1 plants suggested frequent occurrence of chromosome rearrangement, especially those subjected to neon ions. Exposure to ion beams with moderate LET values (30–110 keV/μm) is thought effective for inducing mutant sectors without causing extensive genetic damage.

  14. Investigations on ion-beam induced desorption from cryogenic surfaces; Untersuchungen zu ionenstrahlinduzierter Desorption von kryogenen Oberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Christoph

    2017-07-03

    pumps can be taken into account. This method can be extended to any desorption experiment employing the single shot method for measurement. Of special interest for the operation of the SIS100 at high intensities is the minimization of desorption from cryogenic surfaces. A previous examination of this topic found a breakdown of the familiar scaling of the desorption yield with the beam's energy loss for cryogenic targets. Further examination of this effect with the techniques described above is another goal of this thesis. Simultaneously, desorption measurements at room temperature for several other targets have been conducted. An unexpected result of these experiments is the influence of target surface properties, which was found to be very weak in comparison to previous results. The methods developed during this thesis, along with the results gained by their application, represent another step towards the comprehension of (heavy) ion beam induced desorption.

  15. VARIATIONALLY-BASED EFFECTIVE DYNAMIC THICKNESS FOR LAMINATED GLASS BEAMS

    Directory of Open Access Journals (Sweden)

    Jaroslav Schmidt

    2017-11-01

    Full Text Available Laminated glass, consisting of glass layers connected with transparent foils, has found its applications in civil, automotive, or marine engineering. Due to a high contrast in layer properties, mechanical response of laminated glass structures cannot be predicted using classical laminate theories. On the other hand, engineering applications demand easy-to-use formulas of acceptable accuracy. This contribution addresses such simplified models for free vibrations of laminated glass beams, with the goal to determine their natural frequencies and modal damping properties. Our strategy is to approximate the complex behavior of a laminated structure with that of an equivalent monolithic beam. Its effective thickness is determined by the variational method proposed by Galuppi and Royer-Carfagni for static problems, which we extended for modal analysis. We show that this new approach overcomes inaccuracies of the currently used dynamic effective thickness model by López-Aenlle and Pelayo.

  16. Effects of dipole magnet inhomogeneities on the beam ellipsoid

    International Nuclear Information System (INIS)

    Tsoupas, N.; Colman, J.; Levine, M.; McKenzie-Wilson, R.; Ward, T.; Grand, P.

    1986-01-01

    The RAYTRACE computer code has been modified to accept magnetic fields measured in the median plane of a dipole magnet. This modification allows one to study the effects of a non-ideal dipole magnet on the beam ellipsoid (as defined by the TRANSPORT code manual). The effects on the beam ellipsoid are due to: field inhomogeneities in the interior region of the dipole, and discrepancies from design conditions of the magnetic field values in the fringe field region. The results of the RAYTRACE code calculations based on experimentally measured fields will be compared with the results derived using both an ideal (no inhomogeneities) dipole with SCOFF boundaries and an ideal dipole with perfect (according to design) fringe fields

  17. Fluka Studies of the Asynchronous Beam Dump Effects on LHC Point 6 for a 7 TeV beam

    CERN Document Server

    VERSACI, R; GODDARD, B; MEREGHETTI, A; SCHMIDT, R; VLACHOUDIS, V

    2012-01-01

    The LHC is a record-breaking machine for beam energy and intensity. An intense effort has therefore been deployed in simulating critical operational scenarios of energy deposition. Using FLUKA Monte Carlo simulations, we have investigated the effects of an asynchronous beam dump at the LHC Point 6 where beams, with a stored energy of 360 MJ, can instantaneously release up to a few J cm^{-3} in the cryogenic magnets which have a quench limit of the order of the mJ cm^{-3}. In the present paper we will describe the simulation approach, and discuss the evaluated maximum energy release onto the superconducting magnets during an asynchronous beam dump of a 7 TeV beam. We will then analyze the shielding provided by collimators installed in the area and discuss safety limits for the operation of the LHC.

  18. EFFECT OF SPACE CHARGE ON STABILITY OF BEAM DISTRIBUTION IN THE SNS RING

    International Nuclear Information System (INIS)

    FEDOTOV, A.V.; WEI, J.; GLUCKSTERN, R.L.

    2001-01-01

    In the Spallation Neutron Source (SNS) ring, multi-turn injection is employed to obtain a large transverse beam size which significantly reduces the space-charge tune shift of the accumulated beam. Careful choice of the painting scheme and bump function is required to obtain the desired beam profile together with low beam loss. In this paper we examine, both analytically and numerically, the effect of the space charge on the beam profile during multi-turn injection painting

  19. Explicit expression for effective moment of inertia of RC beams

    OpenAIRE

    Patel, K.A.; Bhardwaj, A.; Chaudhary, S.; Nagpal, A.K.

    2015-01-01

    AbstractDeflection is an important design parameter for structures subjected to service load. This paper provides an explicit expression for effective moment of inertia considering cracking, for uniformly distributed loaded reinforced concrete (RC) beams. The proposed explicit expression can be used for rapid prediction of short-term deflection at service load. The explicit expression has been obtained from the trained neural network considering concrete cracking, tension stiffening and entir...

  20. Effects of electron beam irradiation on tin dioxide gas sensors

    Indian Academy of Sciences (India)

    WINTEC

    Effects of electron beam irradiation on tin dioxide gas sensors. 85 tron irradiation dose. Under low irradiation dose, <300 kGy, the sensitivity of SnO2 thin film shifts slightly, from 300–. 850 kGy, the sensitivity increases greatly, at 850 kGy and it reaches 24⋅8. Then the sensitivity reaches maximum and remains stable while ...

  1. Experimental verification of secondary effects of prestressed beam at ULS

    Directory of Open Access Journals (Sweden)

    Peter Pažma

    2016-03-01

    Full Text Available The paper deals with secondary effects of prestressing at ultimate limit state when statically indeterminate structure has changed its structural form due to development of plastic hinges in critical cross-sections. The article presents results of an experimental program which was carried out at Slovak University of Technology in Bratislava on two span continuous beams post-tensioned by two single-strand tendons subjected to experimental load which has changed structural system into kinematic mechanism.

  2. In-beam PET measurement of $^{7}Li^{3+}$ irradiation induced $\\beta^+}$-activity

    CERN Document Server

    Priegnitz, M; Parodi, K; Sommerer, F; Fiedler, F; Enghardt, W

    2008-01-01

    At present positron emission tomography (PET) is the only feasible method of an in situ and non-invasive monitoring of patient irradiation with ions. At the experimental carbon ion treatment facility of the Gesellschaft für Schwerionenforschung (GSI) Darmstadt an in-beam PET scanner has been integrated into the treatment site and lead to a considerable quality improvement of the therapy. Since ions other than carbon are expected to come into operation in future patient treatment facilities, it is highly desirable to extend in-beam PET also to other therapeutic relevant ions, e.g. 7Li. Therefore, by means of the in-beam PET scanner at GSI the β+-activity induced by 7Li3+ ions has been investigated for the first time. Targets of PMMA, water, graphite and polyethylene were irradiated with monoenergetic, pencil-like beams of 7Li3+ with energies between 129.1 A MeV and 205.3 A MeV and intensities ranging from 3.0 × 107 to 1.9 × 108 ions s−1. This paper presents the measured β+-activity profiles as well as d...

  3. Time-of-flight MeV-SIMS with beam induced secondary electron trigger

    Energy Technology Data Exchange (ETDEWEB)

    Schulte-Borchers, Martina, E-mail: marschul@phys.ethz.ch; Döbeli, Max; Müller, Arnold Milenko; George, Matthias; Synal, Hans-Arno

    2016-08-01

    A new Time-of-flight MeV Secondary Ion Mass Spectrometry (MeV-SIMS) setup was developed to be used with a capillary microprobe for molecular imaging with heavy primary ions at MeV energies. Due to the low output current of the ion collimating capillary a Time-of-flight (ToF) measurement method with high duty cycle is necessary. Secondary electrons from the sample surface and transmitted ions were studied as start signals. They enable measurements with a continuous primary beam and unpulsed ToF spectrometer. Tests with various primary ion beams and sample types have shown that a secondary electron signal is obtained from 30% to 40% of incident MeV particles. This provides a ToF start signal with considerably better time resolution than the one obtained from transmitted primary ions detected in a radiation hard gas ionization detector. Beam induced secondary electrons therefore allow for MeV-SIMS measurements with reasonable mass resolution at primary ion beam currents in the low fA range.

  4. Proteome Changes in Maize Embryo (Zea mays L) Induced by Ion Beam Implantation Treatment

    Science.gov (United States)

    Li, Yongliang; Tang, Jihua; Qin, Guangyong; Huo, Yuping; Tian, Shuangqi

    2009-08-01

    Low energy ion beam implantation was applied to the maize (Zea mays L) embryo proteome using two-dimensional gel electrophoresis. Protein profile analysis detected more than 1100 protein spots, 72 of which were determined to be expressed differently in the treated and control (not exposed to ion beam implantation) embryos. Of the 72 protein spots, 53 were up-regulated in the control and 19 were more abundantly expressed in the ion beam-treated embryos. The spots of up- or down-regulated proteins were identified by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). Among the identified proteins, 11 were up-regulated in the treated embryos. Four of these up-regulated proteins were antioxidant molecules, three were related to stress response, two to sugar metabolism and two were associated with heat shock response. Of the five proteins up-regulated in the control embryos, three were functionally related to carbohydrate metabolism; the functions of the remaining two proteins were unknown. The data collected during this study indicate that treatment of maize embryos with low energy ion beam implantation induces changes in stress tolerance enzymes/proteins, possibly as a result of alterations in metabolism.

  5. Effect of N+ beam exposure on superoxide dismutase and catalase activities and induction of Mn-SOD in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Song Daojun; Chen Ruolei; Shao Chunlin; Wu Lijun; Yu Zengliang

    2000-01-01

    Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. The superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N + beam exposure was examined. Their activities were increased by N + beam exposure from 8 x 10 14 ions/cm 2 to 6 x 10 15 ions/cm 2 . The treatment of H 2 O 2 and [CHCl 3 + CH 3 CH 2 OH] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of Mn-SOD in D. radiodurans AS1.633 by N + beam exposure. These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidisation

  6. Effect of flexural crack on plain concrete beam failure mechanism A numerical simulation

    Directory of Open Access Journals (Sweden)

    Abdoullah Namdar

    2016-03-01

    Full Text Available The flexural failure of plain concrete beam occurs along with development of flexural crack on beam. In this paper by using ABAQUS, mechanism failure of plain concrete beam under three steps have been simulated. The cracking moment has been analytically calculated and applied on the both sides of the fixed beam, and flexural crack has been simulated on beam. Displacement, von Mises, load reaction, displacementcrack length, von Mises-crack length and von Mises-displacement of beams have been graphical depicted. Results indicated that, the flexural crack governs beam mechanism failure and its effects on beam resistance failure. It has been found that the flexural crack in initial stage it developed slowly and changes to be fast at the final stage of collapsing beam due to reduction of the flexural resistance of beam. Increasing mechanical properties of concrete, collapse displacement is reduced.

  7. Precessed electron beam electron energy loss spectroscopy of graphene: Beyond channelling effects

    International Nuclear Information System (INIS)

    Yedra, Ll.; Estradé, S.; Torruella, P.; Eljarrat, A.; Peiró, F.; Darbal, A. D.; Weiss, J. K.

    2014-01-01

    The effects of beam precession on the Electron Energy Loss Spectroscopy (EELS) signal of the carbon K edge in a 2 monolayer graphene sheet are studied. In a previous work, we demonstrated the use of precession to compensate for the channeling-induced reduction of EELS signal when in zone axis. In the case of graphene, no enhancement of EELS signal is found in the usual experimental conditions, as graphene is not thick enough to present channeling effects. Interestingly, though it is found that precession makes it possible to increase the collection angle, and, thus, the overall signal, without a loss of signal-to-background ratio

  8. Beam-induced wakefield observation in X-band choke-mode cavities

    Directory of Open Access Journals (Sweden)

    Hao Zha

    2016-08-01

    Full Text Available The X-band choke-mode structure is currently being studied as an alternative design for the accelerating structure of the compact linear collider (CLIC main linac. The geometry of the choke-mode structure is designed to ensure the strong suppression of the beam-induced long-range transverse wakefield and therefore maintain the stability and quality of the beam in the CLIC main linac. Experiments conducted at the Argonne Wakefield Accelerator Facility are presented in this study to verify the design of the wakefield suppressor. The beam-induced radio frequency (rf signals in a three-cell choke-mode structure were measured, and measured results show good agreement with the simulation results. The measured results also show strong damping in high-order dipolar modes with a quality factor Q of 10 to 20. The difference between the frequencies of the first and second dipole modes is about 3 GHz, which validates the special design of the cancelling dipole modes at the time of the succeeding bunch (0.5 ns.

  9. Beam-induced wakefield observation in X -band choke-mode cavities

    Science.gov (United States)

    Zha, Hao; Jing, Chunguang; Qiu, Jiaqi; Wisniewski, Eric E.; Conde, Manoel; Power, John G.; Doran, Darrell S.; Liu, Wanming; Shi, Jiaru; Li, Chen; Gai, Wei; Chen, Huaibi

    2016-08-01

    The X -band choke-mode structure is currently being studied as an alternative design for the accelerating structure of the compact linear collider (CLIC) main linac. The geometry of the choke-mode structure is designed to ensure the strong suppression of the beam-induced long-range transverse wakefield and therefore maintain the stability and quality of the beam in the CLIC main linac. Experiments conducted at the Argonne Wakefield Accelerator Facility are presented in this study to verify the design of the wakefield suppressor. The beam-induced radio frequency (rf) signals in a three-cell choke-mode structure were measured, and measured results show good agreement with the simulation results. The measured results also show strong damping in high-order dipolar modes with a quality factor Q of 10 to 20. The difference between the frequencies of the first and second dipole modes is about 3 GHz, which validates the special design of the cancelling dipole modes at the time of the succeeding bunch (0.5 ns).

  10. Confinement Effect on Material Properties of RC Beams Under Flexure

    Science.gov (United States)

    Kulkarni, Sumant; Shiyekar, Mukund Ramchandra; Shiyekar, Sandip Mukund

    2017-12-01

    In structural analysis, especially in indeterminate structures, it becomes essential to know the material and geometrical properties of members. The codal provisions recommend elastic properties of concrete and steel and these are fairly accurate enough. The stress-strain curve for concrete cylinder or a cube specimen is plotted. The slope of this curve is modulus of elasticity of plain concrete. Another method of determining modulus of elasticity of concrete is by flexural test of a beam specimen. The modulus of elasticity most commonly used for concrete is secant modulus. The modulus of elasticity of steel is obtained by performing a tension test of steel bar. While performing analysis by any software for high rise building, cross area of plain concrete is taken into consideration whereas effects of reinforcement bars and concrete confined by stirrups are neglected. Present aim of study is to determine elastic properties of reinforced cement concrete beam. Two important stiffness properties such as AE and EI play important role in analysis of high rise RCC building idealized as plane frame. The experimental program consists of testing of beams (model size 150 × 150 × 700 mm) with percentage of reinforcement varying from 0.54 to 1.63% which commensurate with existing Codal provisions of IS:456-2000 for flexural member. The effect of confinement is considered in this study. The experimental results are verified by using 3D finite element techniques.

  11. Effects of electron beam irradiation on cut flowers and mites

    Energy Technology Data Exchange (ETDEWEB)

    Dohino, Toshiyuki; Tanabe, Kazuo [Yokohama Plant Protection Station (Japan)

    1994-08-01

    Two spotted spider mite, Tetranychus urticae KOCH were irradiated with electron beams (2.5MeV) to develop an alternative quarantine treatment for imported cut flowers. The tolerance of eggs increased with age (1-5-day-old). Immature stages (larva-teleiochrysalis) irradiated at 0.4-0.8kGy increased tolerance with their development. Mated mature females irradiated at 0.4kGy or higher did not produce viable eggs, although temporary recovery was observed at 0.2kGy. Adult males were sterilized at 0.4kGy because non-irradiated virgin females mated with yielded female progeny malformed and sterilized. Various effects of electron beam irradiation were observed when nine species of cut flowers were irradiated in 5MeV Dynamitron accelerator. Chrysanthemum and rose were most sensitive among cut flowers. (author).

  12. Effects of gamma and electron beam irradiation on the properties of calendered cord fabrics

    International Nuclear Information System (INIS)

    Aytac, Ayse; Deniz, Veli; Sen, Murat; Hegazy, El-Sayed; Gueven, Olgun

    2010-01-01

    The effects of gamma and e-beam irradiation on mechanical and structural properties of nylon 66 (Ny 66), nylon 6 (Ny 6) and poly(ethylene terephthalate) (PET) fabrics used in tyres were investigated. The untreated (greige), treated cords and calendered fabrics were irradiated at different doses. It is found that the effects of high energy irradiation on greige, treated cords and calendered fabrics are similar. No protective effect of compounds used in calendering was observed against radiation-induced oxidative degradation. The deterioration effect of gamma irradiation on mechanical properties is much higher than that of e-beam irradiation for all types of samples. Limiting viscosity numbers of both gamma and e-beam irradiated nylon 6 and nylon 66 cords were found to decrease with increasing dose. It is concluded that PET calendered fabric has higher resistance to ionizing radiation. Ny 6 and Ny 66 calendered fabrics are more sensitive even at low doses. Therefore, the effects of high energy irradiation on tyre cords have to be taken into consideration during tyre design reinforced with particularly Ny fabrics if pre-vulcanization with high energy radiation is to be applied.

  13. Multi-channel Andreev reflection in Co-W nanocontacts fabricated using focused electron/ion beam induced deposition.

    Science.gov (United States)

    Sharma, N; Vugts, P; Daniels, C; Keuning, W; Kohlhepp, J T; Kurnosikov, O; Koopmans, B

    2014-12-12

    We report multi-channel electron transport in nano-contacts fabricated using focused electron beam induced deposited (FEBID) cobalt and focused ion beam induced deposited (FIBID) tungsten. Anomalous Andreev reflection (AR) effect is observed to which the conventional Blonder-Tinkham-Klapwijk (BTK) fit cannot be applied. In specific, we have observed multiple number of shoulders near the AR peak, whose origin is unknown in literature. We explain this effect based on a simple model that takes into account the material properties of the FIBID grown W superconductor, as well as the specific interface properties that are an outcome of using FEBID/FIBID as a fabrication technique. We show that numerical calculations using the BTK approximation based on the consideration of multiple channels generate similar shoulders as we observed in the AR experiments. Electrical measurements and x-ray photoemission spectroscopy carried out on FIBID W deposits puts additional evidence towards multi-channel current transport occuring at the interface of the nanocontacts.

  14. Assessment of electron beam-induced abnormal development and DNA damage in Spodoptera litura (F.) (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Yun, Seung-Hwan; Lee, Seon-Woo; Koo, Hyun-Na; Kim, Gil-Hah

    2014-03-01

    The armyworm, Spodoptera litura (F.) is a polyphagous and important agricultural pest worldwide. In this study, we examined the effect of electron beam irradiation on developmental stages, reproduction, and DNA damage of S. litura. Eggs (0-24 h old), larvae (3rd instar), pupae (3 days old after pupation), and adults (24 h after emergence) were irradiated with electron beam irradiation of six levels between 30 and 250 Gy. When eggs were irradiated with 100 Gy, egg hatching was completely inhibited. When the larvae were irradiated, the larval period was significantly delayed, depending on the doses applied. At 150 Gy, the fecundity of adults that developed from irradiated pupae was entirely inhibited. However, electron beam irradiation did not induce the instantaneous death of S. litura adults. Reciprocal crosses between irradiated and unirradiated moths demonstrated that females were more radiosensitive than males. We also conducted the comet assay immediately after irradiation and over the following 5 days period. Severe DNA fragmentation in S. litura cells was observed just after irradiation and the damage was repaired during the post-irradiation period in a time-dependent manner. However, at more than 100 Gy, DNA damage was not fully recovered.

  15. Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run

    CERN Document Server

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Balek, Petr; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boek, Thorsten Tobias; Boelaert, Nele; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Branchini, Paolo; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Bremer, Johan; Brendlinger, Kurt; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Broggi, Francesco; Bromberg, Carl; Bronner, Johanna; 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Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Colas, Jacques; Cole, Stephen; Colijn, Auke-Pieter; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colombo, Tommaso; Colon, German; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Crépé-Renaudin, Sabine; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Curtis, Chris; Cuthbert, Cameron; Cwetanski, Peter; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Dassoulas, James; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lorenzi, Francesco; de Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; De Zorzi, Guido; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Degenhardt, James; Del Peso, Jose; Del Prete, Tarcisio; Delemontex, Thomas; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; 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Fowler, Andrew; Fox, Harald; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Gan, KK; Gao, Yongsheng; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilchriese, Murdock; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Goldfarb, Steven; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Gramstad, Eirik; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guest, Daniel; Guicheney, Christophe; Guido, Elisa; Guindon, Stefan; Gul, Umar; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Hajduk, Zbigniew; Hakobyan, Hrachya; Hall, David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Henß, Tobias; Medina Hernandez, Carlos; Hernández Jiménez, Yesenia; Herrberg, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Hong, Tae Min; Hooft van Huysduynen, Loek; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huettmann, Antje; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Jantsch, Andreas; Janus, Michel; Jared, Richard; Jarlskog, Göran; Jeanty, Laura; Jen-La Plante, Imai; Jennens, David; Jenni, Peter; Loevschall-Jensen, Ask Emil; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Joram, Christian; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagounis, Michael; Karakostas, Konstantinos; Karnevskiy, Mikhail; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Keener, Paul; Kehoe, Robert; Keil, Markus; Kekelidze, George; Keller, John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kitamura, Takumi; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kreiss, Sven; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Mark; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lambourne, Luke; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larner, Aimee; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Laycock, Paul; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Lepold, Florian; Leroy, Claude; Lessard, Jean-Raphael; Lester, Christopher; Lester, Christopher Michael; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Lulu; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lo Sterzo, Francesco; Losty, Michael; Lou, XinChou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lukas, Wolfgang; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundberg, Olof; Lundquist, Johan; Lungwitz, Matthias; Lynn, David; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Macina, Daniela; Mackeprang, Rasmus; Madaras, Ronald; Maddocks, Harvey Jonathan; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magnoni, Luca; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marroquim, Fernando; Marshall, Zach; Martens, Kalen; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian Thomas; Martin, Jean-Pierre; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martin-Haugh, Stewart; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Matricon, Pierre; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzaferro, Luca; Mazzanti, Marcello; Mc Donald, Jeffrey; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meehan, Samuel; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohapatra, Soumya; Mohr, Wolfgang; Moles-Valls, Regina; Molfetas, Angelos; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Narayan, Rohin; Nash, Michael; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newcomer, Mitchel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Brien, Brendan Joseph; O'Neil, Dugan; O'Shea, Val; Oakes, Louise Beth; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Paredes Hernandez, Daniela; Park, Woochun; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pashapour, Shabnaz; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Lopez, Sebastian; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Peshekhonov, Vladimir; Peters, Krisztian; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Peter William; Piacquadio, Giacinto; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; 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Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zibell, Andre; Zieminska, Daria; Zimin, Nikolai; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Živković, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

    2013-07-17

    This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstra...

  16. Electron-beam-induced post-grafting polymerization of acrylic acid onto the surface of Kevlar fibers

    Science.gov (United States)

    Xu, Lu; Hu, Jiangtao; Ma, Hongjuan; Wu, Guozhong

    2018-04-01

    The surface of Kevlar fibers was successfully modified by electron beam (EB)-induced post-grafting of acrylic acid (AA). The generation of radicals in the fibers was confirmed by electron spin resonance (ESR) measurements, and the concentration of radicals was shown to increase as the absorbed dose increased, but decrease with increasing temperature. The influence of the synthesis conditions on the degree of grafting was also investigated. The surface microstructure and chemical composition of the modified Kevlar fibers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed that the surface of the grafted fibers was rougher than those of the pristine and irradiated fibers. XPS analysis confirmed an increase in C(O)OH groups on the surface of the Kevlar fibers, suggesting successful grafting of AA. These results indicate that EB-induced post-grafting polymerization is effective for modifying the surface properties of Kevlar fibers.

  17. Effect of e-beam irradiation on graphene layer grown by chemical vapor deposition

    International Nuclear Information System (INIS)

    Iqbal, M. Z.; Kumar Singh, Arun; Iqbal, M. W.; Seo, Sunae; Eom, Jonghwa

    2012-01-01

    We have grown graphene by chemical vapor deposition (CVD) and transferred it onto Si/SiO 2 substrates to make tens of micron scale devices for Raman spectroscopy study. The effect of electron beam (e-beam) irradiation of various doses (600 to 12 000 μC/cm 2 ) on CVD grown graphene has been examined by using Raman spectroscopy. It is found that the radiation exposures result in the appearance of the strong disorder D band attributed the damage to the lattice. The evolution of peak frequencies, intensities, and widths of the main Raman bands of CVD graphene is analyzed as a function of defect created by e-beam irradiation. Especially, the D and G peak evolution with increasing radiation dose follows the amorphization trajectory, which suggests transformation of graphene to the nanocrystalline and then to amorphous form. We have also estimated the strain induced by e-beam irradiation in CVD graphene. These results obtained for CVD graphene are in line with previous findings reported for the mechanically exfoliated graphene [D. Teweldebrhan and A. A. Balandin, Appl. Phys. Lett. 94, 013101 (2009)]. The results have important implications for CVD graphene characterization and device fabrication, which rely on the electron microscopy.

  18. Modeling of beam-induced damage of the LHC tertiary collimators

    Directory of Open Access Journals (Sweden)

    E. Quaranta

    2017-09-01

    Full Text Available Modern hadron machines with high beam intensity may suffer from material damage in the case of large beam losses and even beam-intercepting devices, such as collimators, can be harmed. A systematic method to evaluate thresholds of damage owing to the impact of high energy particles is therefore crucial for safe operation and for predicting possible limitations in the overall machine performance. For this, a three-step simulation approach is presented, based on tracking simulations followed by calculations of energy deposited in the impacted material and hydrodynamic simulations to predict the thermomechanical effect of the impact. This approach is applied to metallic collimators at the CERN Large Hadron Collider (LHC, which in standard operation intercept halo protons, but risk to be damaged in the case of extraction kicker malfunction. In particular, tertiary collimators protect the aperture bottlenecks, their settings constrain the reach in β^{*} and hence the achievable luminosity at the LHC experiments. Our calculated damage levels provide a very important input on how close to the beam these collimators can be operated without risk of damage. The results of this approach have been used already to push further the performance of the present machine. The risk of damage is even higher in the upgraded high-luminosity LHC with higher beam intensity, for which we quantify existing margins before equipment damage for the proposed baseline settings.

  19. In situ transmission electron microscopy analysis of electron beam induced crystallization of amorphous marks in phase-change materials

    International Nuclear Information System (INIS)

    Kaiser, M.; Pieterson, L. van; Verheijen, M.A.

    2004-01-01

    Crystallization of amorphous data marks in crystalline Ga 15 Sb 85 and Ge,In doped SbTe phase-change material was studied in situ in a Transmission Electron Microscope (TEM). Electron irradiation induced crystallization was obtained at room temperature using a 120 kV beam. In general, electron beam (e - beam) induced crystallization started from the amorphous-crystalline interface and was growth dominated for both materials. A dependence of growth velocity on electron beam intensity and crystal direction was observed. A comparison with laser-crystallized amorphous marks was made. For laser-induced crystallization also crystal growth from the amorphous-crystalline interface was seen. However, differences in morphology between the e - -beam and laser-recrystallized data marks of the GaSb phase-change material were observed. The electron beam erased data marks contained crystals with (extremely) large periodicities found in three dimensions. For the Ge,In doped SbTe phase-change material identical morphologies were observed for the e - -beam and laser-recrystallized data marks. Both methods that induce crystallization displayed a rhombohedral Sb structure, the same structure as the laser-crystallized surroundings

  20. Changes to the chemical structure of isotactic-polypropylene induced by ion-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Oka, T., E-mail: oka.toshitaka@jaea.go.j [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Naka, Ibaraki 319-1195 (Japan); Oshima, A. [The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Motohashi, R.; Seto, N.; Watanabe, Y.; Kobayashi, R.; Saito, K. [Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Kudo, H. [School of Engineering, The University of Tokyo, Naka, Ibaraki 319-1188 (Japan); Murakami, T. [Department of Accelerator Physics and Engineering, National Institute of Radiological Sciences, Inage, Chiba 263-8555 (Japan); Washio, M.; Hama, Y. [Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

    2011-02-15

    The chemical structures of various ion-beam irradiated isotactic-polypropylene samples were studied. Results of micro-Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy suggest not only the linear energy transfer, but also the fluence is effective in local transformation of the isotactic-polypropylene.

  1. The effect of CFRP on retrofitting of damaged HSRC beams using AE technique

    Science.gov (United States)

    Soffian Noor, M. S.; Noorsuhada, M. N.

    2017-12-01

    This paper presents the effect of carbon fibre reinforced polymer (CFRP) on retrofitted high strength reinforced concrete (HSRC) beams using acoustic emission (AE) technique. Two RC beam parameters were prepared. The first was the control beam which was undamaged HSRC beam. The second was the damaged HSRC beam retrofitted with CFRP on the soffit. The main objective of this study is to assess the crack modes of HSRC beams using AE signal strength. The relationship between signal strength, load and time were analysed and discussed. The crack pattern observed from the visual observation was also investigated. HSRC beam retrofitted with CFRP produced high signal strength compared to control beam. It demonstrates the effect of the AE signal strength for interpretation and prediction of failure modes that might occur in the beam specimens.

  2. Modification of some properties of polyamide-6 by electron beam induced grafting

    International Nuclear Information System (INIS)

    Timus, D.M.; Cincu, C.; Bradley, D.A.; Craciun, G.; Mateescu, E.

    2000-01-01

    Electron irradiation, applied on its own or in combination with other physical and chemical treatments, can result in radiation damage to materials. One category of such pursuits is electron beam radiation processing technologies, the intent being to produce favourable modification of materials. Study has been made herein of the use of accelerator-generated electron beams for the induced grafting of acrylic and methacrylic acids and acrylamide onto polyamide-6, the latter being popularly used in the textiles industry. Samples of polyamide-6, in the form of rectangular sheets of dimension, 10 cm x 10 cm or granules, have been irradiated using a 3 GHz travelling wave electron accelerator of energy 6.5 MeV. Results show that the degree of grafting is dependent upon radiation dose and extent of monomers dilution. Modifications have been observed in the melting temperature of the crystalline phase, glass transition temperature, mechanical parameters and the reticulation of polyamide

  3. High resolution laser beam induced current focusing for photoactive surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Lorenzo, C. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain)]. E-mail: concha.fernandez@uca.es; Poce-Fatou, J.A. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain); Alcantara, R. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain); Navas, J. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain); Martin, J. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain)

    2006-12-15

    The micro-characterization of several surface properties of the solar cells can be accomplished using high-resolution laser beam induced current images. For obtaining these images, a very precise laser beam focusing on the photoactive surface is required. For this purpose, a methodology for obtaining the best focalization associated to the maximum of a peak curve has been developed. In this paper, a data set, obtained from the inner photoconversion properties of the system, has been evaluated with three different numerical analysis techniques: (a) derivative (b) length and (c) Fourier Transform, in order to get the finest possible peak distribution. Then, an amount of 13 analytical peak curves using the Levenberg Marquardt algorithm to find the best curve that adjusts the data distribution have been analyzed.

  4. Electron-stimulated purification of platinum nanostructures grown via focused electron beam induced deposition

    Directory of Open Access Journals (Sweden)

    Brett B. Lewis

    2015-04-01

    Full Text Available Platinum–carbon nanostructures deposited via electron beam induced deposition from MeCpPt(IVMe3 are purified during a post-deposition electron exposure treatment in a localized oxygen ambient at room temperature. Time-dependent studies demonstrate that the process occurs from the top–down. Electron beam energy and current studies demonstrate that the process is controlled by a confluence of the electron energy loss and oxygen concentration. Furthermore, the experimental results are modeled as a 2nd order reaction which is dependent on both the electron energy loss density and the oxygen concentration. In addition to purification, the post-deposition electron stimulated oxygen purification process enhances the resolution of the EBID process due to the isotropic carbon removal from the as-deposited materials which produces high-fidelity shape retention.

  5. Analysis of art objects by means of ion beam induced luminescence

    International Nuclear Information System (INIS)

    Quaranta, A; Dran, J C; Salomon, J; Pivin, J C; Vomiero, A; Tonezzer, M; Maggioni, G; Carturan, S; Mea, G Della

    2006-01-01

    The impact of energetic ions on solid samples gives rise to the emission of visible light owing to the electronic excitation of intrinsic defects or extrinsic impurities. The intensity and position of the emission features provide information on the nature of the luminescence centers and on their chemical environments. This makes ion beam induced luminescence (IBIL) a useful complement to other ion beam analyses, like PIXE, in the cultural heritage field in characterizing the composition and the provenience of art objects. In the present paper, IBIL measurements have been performed on inorganic pigments for underlying the complementary role played by IBIL in the analysis of artistic works. Some blue and red pigment has been presented as case study

  6. Electron-beam-irradiation-induced crystallization of amorphous solid phase change materials

    Science.gov (United States)

    Zhou, Dong; Wu, Liangcai; Wen, Lin; Ma, Liya; Zhang, Xingyao; Li, Yudong; Guo, Qi; Song, Zhitang

    2018-04-01

    The electron-beam-irradiation-induced crystallization of phase change materials in a nano sized area was studied by in situ transmission electron microscopy and selected area electron diffraction. Amorphous phase change materials changed to a polycrystalline state after being irradiated with a 200 kV electron beam for a long time. The results indicate that the crystallization temperature strongly depends on the difference in the heteronuclear bond enthalpy of the phase change materials. The selected area electron diffraction patterns reveal that Ge2Sb2Te5 is a nucleation-dominated material, when Si2Sb2Te3 and Ti0.5Sb2Te3 are growth-dominated materials.

  7. Optical beam induced current measurements: principles and applications to SiC device characterization

    Energy Technology Data Exchange (ETDEWEB)

    Raynaud, Christophe; Nguyen, Duy-Minh; Dheilly, Nicolas; Tournier, Dominique; Brosselard, Pierre; Lazar, Mihai; Planson, Dominique [Ampere Laboratory UMR CNRS, INSA de Lyon, Villeurbanne (France)

    2009-10-15

    This paper deals with the characterization of SiC devices by optical beam induced currents (OBIC). OBIC is a technique that measures a photocurrent in response to a fine UV laser beam that is scanned laterally over the surface of the device. In this way a number of important material and device parameters can be derived. We concentrate here on three aspects, the field profile in reverse biased diodes with particular emphasis on field terminating issues at the device edges under high reverse voltages; the minority carrier lifetimes in 6H-SiC; and the determination of ionization coefficients for electrons and holes in 6H-SiC. The latter are important material parameters for the modelling of high power devices and determine their break-through voltage. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Phase-transition oscillations induced by a strongly focused laser beam.

    Science.gov (United States)

    Devailly, Clémence; Crauste-Thibierge, Caroline; Petrosyan, Artyom; Ciliberto, Sergio

    2015-11-01

    We report the observation of a surprising phenomenon consisting in a oscillating phase transition which appears in a binary mixture when this is enlightened by a strongly focused infrared laser beam. The mixture is poly-methyl-meth-acrylate (PMMA)-3-octanone, which has an upper critical solution temperature at T(c)=306.6K and volume fraction ϕ(c)=12.8% [Crauste et al., arXiv:1310.6720, 2013]. We describe the dynamical properties of the oscillations, which are produced by a competition between various effects: the local accumulation of PMMA produced by the laser beam, thermophoresis, and nonlinear diffusion. We show that the main properties of this kind of oscillations can be reproduced in the Landau theory for a binary mixture in which a local driving mechanism, simulating the laser beam, is introduced.

  9. Simulation-aided investigation of beam hardening induced errors in CT dimensional metrology

    DEFF Research Database (Denmark)

    Tan, Ye; Kiekens, Kim; Welkenhuyzen, Frank

    2014-01-01

    are mutually correlated, it remains challenging to interpret measurement results and to identify the distinct error sources. Since simulations allow isolating the different affecting factors, they form a useful complement to experimental investigations. Dewulf et al (2012 CIRP Ann. Manuf. Technol. 61 495......–8) investigated the influence of beam hardening correction parameters on the diameter of a calibrated steel pin in different experimental set-ups. It was clearly shown that an inappropriate beam hardening correction can result in significant dimensional errors. This paper confirms these results using simulations...... of a pin surrounded by a stepped cylinder: a clear discontinuity in the measured diameter of the inner pin is observed where it enters the surrounding material. The results are expanded with an investigation of the beam hardening effect on the measurement results for both inner and outer diameters...

  10. Simulation-aided investigation of beam hardening induced errors in CT dimensional metrology

    DEFF Research Database (Denmark)

    Tan, Ye; Kiekens, Kim; Welkenhuyzen, Frank

    2013-01-01

    most of these factors are mutually correlated, it remains challenging to interpret measurement results and to identify the distinct error sources. Since simulations allow isolating the different affecting factors, they form a useful complement to experimental investigations. Dewulf et.al [5......] investigated the influence of beam hardening correction parameters on the diameter of a calibrated steel pin in different experimental set-ups. It was clearly shown that inappropriate beam hardening correction can result in significant dimensional errors. This paper confirms these results using simulations...... of a pin surrounded by a stepped cylinder: a clear discontinuity in the measured diameter of the inner pin is observed where it enters the surrounding material. The results are expanded with an investigation of the beam hardening effect on the measurement results for both inner and outer diameters...

  11. Effects of Electron Beam Loading on an Operating Piezoelectric Transformer

    Science.gov (United States)

    2013-06-01

    Abstract Piezoelectric transformers (PTs) are currently being used to accelerate charged-particle beams for various applications [1, 2]. Beam...to maximize the transformer ratio of length-extensional piezoelectric transformers , these studies have typically been performed for discrete...Piezoelectric transformers (PTs) are currently being used to accelerate charged-particle beams for various applications [1, 2]. Beam interactions at the output

  12. Effects of ambient gas in beam drift space on performance of high brightness and low energy ion beam

    International Nuclear Information System (INIS)

    Yoshikawa, T.; Nakamura, S.; Ueda, Y.; Nishikawa, M.; Goto, S.

    1995-01-01

    Effects of the ambient gas in the ion drift space on the transport property of the low energy (155 eV) and high brightness beam are studied experimentally. A bucket ion source with single-aperture triode extraction is used. Beam characteristics such as the divergence angle and the current density are improved by the increase in the ambient gas pressure in the high brightness beam (high deceleration voltage, -2000 V), but not in the low brightness beam (low deceleration voltage, -600 V). The beam spreading due to the space charge of the ion beam is seen at the low ambient gas pressure when the central current density, which is measured at 35 cm downstream side from the electrode system, exceeds 5 μA/cm 2 . The electron density in the ion-beam plasma increases with the ambient gas pressure, but the space charge is not sufficiently neutralized by the electrons produced by the ambient gas atom ionization. copyright 1995 American Institute of Physics

  13. Effective dose range for dental cone beam computed tomography scanners

    International Nuclear Information System (INIS)

    Pauwels, Ruben; Beinsberger, Jilke; Collaert, Bruno; Theodorakou, Chrysoula; Rogers, Jessica; Walker, Anne; Cockmartin, Lesley; Bosmans, Hilde; Jacobs, Reinhilde; Bogaerts, Ria; Horner, Keith

    2012-01-01

    Objective: To estimate the absorbed organ dose and effective dose for a wide range of cone beam computed tomography scanners, using different exposure protocols and geometries. Materials and methods: Two Alderson Radiation Therapy anthropomorphic phantoms were loaded with LiF detectors (TLD-100 and TLD-100H) which were evenly distributed throughout the head and neck, covering all radiosensitive organs. Measurements were performed on 14 CBCT devices: 3D Accuitomo 170, Galileos Comfort, i-CAT Next Generation, Iluma Elite, Kodak 9000 3D, Kodak 9500, NewTom VG, NewTom VGi, Pax-Uni3D, Picasso Trio, ProMax 3D, Scanora 3D, SkyView, Veraviewepocs 3D. Effective dose was calculated using the ICRP 103 (2007) tissue weighting factors. Results: Effective dose ranged between 19 and 368 μSv. The largest contributions to the effective dose were from the remainder tissues (37%), salivary glands (24%), and thyroid gland (21%). For all organs, there was a wide range of measured values apparent, due to differences in exposure factors, diameter and height of the primary beam, and positioning of the beam relative to the radiosensitive organs. Conclusions: The effective dose for different CBCT devices showed a 20-fold range. The results show that a distinction is needed between small-, medium-, and large-field CBCT scanners and protocols, as they are applied to different indication groups, the dose received being strongly related to field size. Furthermore, the dose should always be considered relative to technical and diagnostic image quality, seeing that image quality requirements also differ for patient groups. The results from the current study indicate that the optimisation of dose should be performed by an appropriate selection of exposure parameters and field size, depending on the diagnostic requirements.

  14. Electron beam radiation effects on recycled polyamide-6

    International Nuclear Information System (INIS)

    Evora, Maria Cecilia; Silva, Leonardo G. de Andrade e

    2001-01-01

    Applications of electron beam processing in the treatment of polymers are commonly used. The interaction of high energy radiation with polymers may cause permanent modifications in the polymer's physicochemical structure. The induced modifications may result in degradation of the polymer or in improvement of its properties (crosslinking), which are simultaneous and competing processes, depending on the radiation dose utilized. Crosslinking occurs more readily in the polymer's amorphous content and this process makes the glass transition temperature (Tg) of the polymers to increase. Successive recycling cycles promote changes in polymers properties, such as breaking of structure, molecular weight reduction, melt index increase and mechanical resistance reduction. The polyamide-6 resin was recycled for three successive recycling cycles and thi polyamide-6 specimens were molded by the process of injection molding. These specimens were irradiated at the Nuclear Energetic Research Institute (IPEN) radiation facility, on a JOB 188 model accelerator, with a 1.5 MeV electron beam, doses of 200, 300, 400, 500 and 600 kGy, and dose rate of 22.61 kGy/s. The DMA tests were performed using DMA-983 equipment from TA Instruments and two heatings were adopted in order to eliminate the moisture absorption. The X-ray diffraction analysis wa carried out at the Philips PW 1830 model equipment

  15. Relativistic beaming and orientation effects in core-dominated quasars

    International Nuclear Information System (INIS)

    Ubachukwu, A.A.; Chukwude, A.E.

    2002-07-01

    In this paper, we investigate the relativistic beaming effects in a well-defined sample of core- dominated quasars using the correlation between the relative prominence of the core with respect to the extended emission (defined as the ratio of the core- to the lobe- flux density measured in the rest frame of the source) and the projected linear size as an indicator of relativistic beaming and source orientation. Based on the orientation-dependent relativistic beaming and unification paradigm for high luminosity sources in which the Fanaroff-Riley class-ll radio galaxies form the unbeamed parent population of both the lobe- and core-dominated quasars which are expected to lie at successively smaller angles to the line of sight, we find that the flows in the cores of these core-dominated quasars are highly relativistic, with optimum bulk Lorentz factor, γ opt ∼6-16, and also highly anisotropic, with an average viewing angle, ∼ 9 deg. - 16 deg. Furthermore, the largest boosting occurs within a critical cone angle of ∼ 4 deg. - 10 deg. The results suggest that relativistic bulk flow appears to extend to kilo-parsec scales in these sources. (author)

  16. Relativistic beaming and orientation effects in core-dominated quasars

    CERN Document Server

    Ubachukwu, A A

    2002-01-01

    In this paper, we investigate the relativistic beaming effects in a well-defined sample of core-dominated quasars using the correlation between the relative prominence of the core with respect to the extended emission (defined as the ratio of the core- to the lobe- flux density measured in the rest frame of the source) and the projected linear size as an indicator of relativistic beaming and source orientation. Based on the orientation-dependent relativistic beaming and unification paradigm for high luminosity sources in which the Fanaroff-Riley class-II radio galaxies form the unbeamed parent population of both the lobe- and coredominated quasars which are expected to lie at successively smaller angles to the line of sight, we find that the flows in the cores of these coredominated quasars are highly relativistic, with optimum bulk Lorentz factor, $\\gamma_{opt}\\sim6-16$, and also highly anisotropic, with an average viewing angle, $\\sim9^0-16^0$. Furthermore, the largest boosting occurs within a critical cone...

  17. Reduction of metal artifacts: beam hardening and photon starvation effects

    Science.gov (United States)

    Yadava, Girijesh K.; Pal, Debashish; Hsieh, Jiang

    2014-03-01

    The presence of metal-artifacts in CT imaging can obscure relevant anatomy and interfere with disease diagnosis. The cause and occurrence of metal-artifacts are primarily due to beam hardening, scatter, partial volume and photon starvation; however, the contribution to the artifacts from each of them depends on the type of hardware. A comparison of CT images obtained with different metallic hardware in various applications, along with acquisition and reconstruction parameters, helps understand methods for reducing or overcoming such artifacts. In this work, a metal beam hardening correction (BHC) and a projection-completion based metal artifact reduction (MAR) algorithms were developed, and applied on phantom and clinical CT scans with various metallic implants. Stainless-steel and Titanium were used to model and correct for metal beam hardening effect. In the MAR algorithm, the corrupted projection samples are replaced by the combination of original projections and in-painted data obtained by forward projecting a prior image. The data included spine fixation screws, hip-implants, dental-filling, and body extremity fixations, covering range of clinically used metal implants. Comparison of BHC and MAR on different metallic implants was used to characterize dominant source of the artifacts, and conceivable methods to overcome those. Results of the study indicate that beam hardening could be a dominant source of artifact in many spine and extremity fixations, whereas dental and hip implants could be dominant source of photon starvation. The BHC algorithm could significantly improve image quality in CT scans with metallic screws, whereas MAR algorithm could alleviate artifacts in hip-implants and dentalfillings.

  18. Study of an instability of the PEP-II positron beam (Ohmi effect and multipactoring)

    International Nuclear Information System (INIS)

    Heifets, S.A.

    1995-11-01

    The paper is organized in the following way. First, Ohmi effect induced by direct flow of primary photoelectrons is studied for the PEP-II parameters. The production rate and kinematics take into account the antechamber of the LER. We discuss the effect of the secondary emission of electrons in the AL chamber, where the yield is larger than one. Resonance multipactoring is considered, and then the average density of the secondary electrons is estimated taking into account the space-charge effect and the interaction with the beam. We show that in the extreme case there is a self-consistent regime similar to the regime of the space-charge dominated cathode. Finally, the rate of ion production by accumulated electrons and the possibility of the ion induced pressure instability is discussed

  19. SU-F-J-205: Effect of Cone Beam Factor On Cone Beam CT Number Accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Yao, W; Hua, C; Farr, J; Brady, S; Merchant, T [St. Jude Children’s Research Hospital, Memphis, TN (United States)

    2016-06-15

    Purpose: To examine the suitability of a Catphan™ 700 phantom for image quality QA of a cone beam computed tomography (CBCT) system deployed for proton therapy. Methods: Catphan phantoms, particularly Catphan™ 504, are commonly used in image quality QA for CBCT. As a newer product, Catphan™ 700 offers more tissue equivalent inserts which may be useful for generating the electron density – CT number curve for CBCT based treatment planning. The sensitometry-and-geometry module used in Catphan™ 700 is located at the end of the phantom and after the resolution line pair module. In Catphan™ 504 the line pair module is located at the end of the phantom and after the sensitometry-and-geometry module. To investigate the effect of difference in location on CT number accuracy due to the cone beam factor, we scanned the Catphan™ 700 with the central plane of CBCT at the center of the phantom, line pair and sensitometry-andgeometry modules of the phantom, respectively. The protocol head and thorax scan modes were used. For each position, scans were repeated 4 times. Results: For the head scan mode, the standard deviation (SD) of the CT numbers of each insert under 4 repeated scans was up to 20 HU, 11 HU, and 11 HU, respectively, for the central plane of CBCT located at the center of the phantom, line pair, and sensitometry-and-geometry modules of the phantom. The mean of the SD was 9.9 HU, 5.7 HU, and 5.9 HU, respectively. For the thorax mode, the mean of the SD was 4.5 HU, 4.4 HU, and 4.4 HU, respectively. The assessment of image quality based on resolution and spatial linearity was not affected by imaging location changes. Conclusion: When the Catphan™ 700 was aligned to the center of imaging region, the CT number accuracy test may not meet expectations. We recommend reconfiguration of the modules.

  20. 3D magnetic nanostructures grown by focused electron and ion beam induced deposition

    Science.gov (United States)

    Fernandez-Pacheco, Amalio

    Three-dimensional nanomagnetism is an emerging research area, where magnetic nanostructures extend along the whole space, presenting novel functionalities not limited to the substrate plane. The development of this field could have a revolutionary impact in fields such as electronics, the Internet of Things or bio-applications. In this contribution, I will show our recent work on 3D magnetic nanostructures grown by focused electron and ion beam induced deposition. This 3D nano-printing techniques, based on the local chemical vapor deposition of a gas via the interaction with electrons and ions, makes the fabrication of complex 3D magnetic nanostructures possible. First, I will show how by exploiting different growth regimes, suspended Cobalt nanowires with modulated diameter can be patterned, with potential as domain wall devices. Afterwards, I will show recent results where the synthesis of Iron-Gallium alloys can be exploited in the field of artificial multiferroics. Moreover, we are developing novel methodologies combining physical vapor deposition and 3D nano-printing, creating Permalloy 3D nanostrips with controllable widths and lengths up to a few microns. This approach has been extended to more complex geometries by exploiting advanced simulation growth techniques combining Monte Carlo and continuum model methods. Throughout the talk, I will show the methodology we are following to characterize 3D magnetic nanostructures, by combining magneto-optical Kerr effect, scanning probe microscopy and electron and X-R magnetic imaging, and I will highlight some of the challenges and opportunities when studying these structures. I acknowledge funding from EPSRC and the Winton Foundation.

  1. Radiation induced synthesis of gold/iron-oxide composite nanoparticles using high-energy electron beam

    International Nuclear Information System (INIS)

    Seino, Satoshi; Kinoshita, Takuya; Nakagawa, Takashi; Kojima, Takao; Taniguci, Ryoichi; Okuda, Shuichi; Yamamoto, Takao A.

    2008-01-01

    Composite nanoparticles consisting of gold and iron oxide were synthesized in aqueous solution systems by using a high-energy electron beam. The electron irradiation induces radiation-chemical reaction to form metallic gold nanoparticles. These gold nanoparticles were firmly immobilized on the surface of the support iron oxide nanoparticles. Surface of the support iron oxide nanoparticles are almost fully coated with fine gold nanoparticles. The size of these gold nanoparticles depended on the concentrations of gold ions, polymers and iron oxide nanoparticles in the solutions before the irradiation.

  2. Spectroscopic Evidence for Exceptional Thermal Contribution to Electron-Beam Induced Fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, Marissa A.; Haynor, Ben; Aloni, Shaul; Ogletree, D. Frank; Wong, H.-S. Philip; Urban, Jeffrey J.; Milliron, Delia J.

    2010-11-16

    While electron beam induced fragmentation (EBIF) has been reported to result in the formation of nanocrystals of various compositions, the physical forces driving this phenomenon are still poorly understood. We report EBIF to be a much more general phenomenon than previously appreciated, operative across a wide variety of metals, semiconductors and insulators. In addition, we leverage the temperature dependent bandgap of several semiconductors to quantify -- using in situ cathodoluminescence spectroscopy -- the thermal contribution to EBIF, and find extreme temperature rises upwards of 1000K.

  3. Ion desorption induced by charged particle beams: mechanisms and mass spectroscopy

    International Nuclear Information System (INIS)

    Silveira, E.F. da; Schweikert, E.A.

    1988-01-01

    Surface analysis, through desorption, induced by fast particles, is presented and discussed. The stopping of projectils is essentially made by collisions with the target electrons. The desorbed particles are generally emmited with kinetic energy from 0.1 to 20 eV. Mass, charge, velocity and emission angle give information about the surface components, its structure as well as beam-solid interaction processes. Time-of-flight mass spectroscopy of desorbed ions, determine the mass of organic macromolecules and biomolecules. (A.C.A.S.) [pt

  4. A new route to nanoscale tomographic chemical analysis: Focused ion beam-induced auger electron spectrosocpy

    Science.gov (United States)

    Parvaneh, Hamed

    This research project is aimed to study the application of ion-induced Auger electron spectroscopy (IAES) in combination with the characteristics of focused ion beam (FIB) microscopy for performing chemical spectroscopy and further evaluate its potential for 3-dimensional chemical tomography applications. The mechanism for generation of Auger electrons by bombarding ions is very different from its electron induced counterpart. In the conventional electron-induced Auger electron spectroscopy (EAES), an electron beam with energy typically in the range 1-10kV is used to excite inner-shell (core) electrons of the solid. An electron from a higher electron energy state then de-excites to fill the hole and the extra energy is then transferred to either another electron, i.e. the Auger electron, or generation of an X-ray (photon). In both cases the emitting particles have charac-teristic energies and could be used to identify the excited target atoms. In IAES, however, large excitation cross sections can occur by promotion of in-ner shell electrons through crossing of molecular orbitals. Originally such phenomenological excitation processes were first proposed [3] for bi-particle gas phase collision systems to explain the generation of inner shell vacancies in violent collisions. In addition to excitation of incident or target atoms, due to a much heavier mass of ions compared to electrons, there would also be a substantial momentum transfer from the incident to the target atoms. This may cause the excited target atom to recoil from the lattice site or alternatively sputter off the surface with the possibility of de-excitation while the atom is either in motion in the matrix or traveling in vacuum. As a result, one could expect differences between the spectra induced by incident electrons and ions and interpretation of the IAE spectra requires separate consideration of both excitation and decay processes. In the first stage of the project, a state-of-the-art mass

  5. Asymmetric Light Curves of Black Hole Binaries and the Doppler Beaming Effect

    Directory of Open Access Journals (Sweden)

    Hee-Won Lee

    2002-03-01

    Full Text Available Black hole binary candidates are known to be composed of a black hole with 10Msolar and a K or M type companion. Because the companion is believed to fill the Roche lobe that is very aspherical, the light curves of black hole binaries are characterized by an ellipsoidal variation. It has been known that the ellipsoidal light curves exhibit asymmetric maximum brightness at the orbital phases 0.25 and 0.75, which has been attributed to star spots or the hot impact points of the accretion flow on to the accretion disk around the black hole. In this paper, it is pointed out that the special relativistic beaming effect contributes to the asymmetry of several percent often observed in the light curves. The typical orbital velocity 400 km s-1 observed in black hole binaries may induce the temperature difference Δ T/T~1/400 of the late type companion star in the observer's rest frame, because of the special relativistic Doppler beaming effect. This difference in temperature can result in several per cent of brightness sensitively dependent on the wavelength band, which is comparable to what has been observed in most black hole binary candidates. Considering the significant contribution of the special relativistic Doppler beaming effect, we conclude that the estimation of the sizes and temperatures of the star spots or the hot impact point needs serious revision.

  6. Effect of pulse electron beam characteristics on internal friction and structural alterations in epoxy

    Energy Technology Data Exchange (ETDEWEB)

    Zaikin, Yu.A. [Al Farabi Kazakh National University, Almaty (Kazakhstan)]. E-mail: drzaykin@mail.ru; Ismailova, G.A. [Al Farabi Kazakh National University, Almaty (Kazakhstan); Al-Sheikhly, M. [University of Maryland, College Park (United States)

    2007-08-15

    Temperature dependence of internal friction is experimentally studied in epoxy irradiated by 2.5 MeV pulse electron beam to different doses. Time dependence of internal friction characteristics associated with radiation-induced processes of polymer scission and cross-linking is analyzed and discussed. Experimental data on kinetics of structural transformations in epoxy are interpreted on the base of analytical solutions of differential equations for free radical accumulation during and after irradiation subject to the pulse irradiation mode and an arbitrary effective order of radical recombination.

  7. Effect of pulse electron beam characteristics on internal friction and structural alterations in epoxy

    International Nuclear Information System (INIS)

    Zaikin, Yu.A.; Ismailova, G.A.; Al-Sheikhly, M.

    2007-01-01

    Temperature dependence of internal friction is experimentally studied in epoxy irradiated by 2.5 MeV pulse electron beam to different doses. Time dependence of internal friction characteristics associated with radiation-induced processes of polymer scission and cross-linking is analyzed and discussed. Experimental data on kinetics of structural transformations in epoxy are interpreted on the base of analytical solutions of differential equations for free radical accumulation during and after irradiation subject to the pulse irradiation mode and an arbitrary effective order of radical recombination

  8. Radiation effect of low energy electron beam on plant growth

    International Nuclear Information System (INIS)

    Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    Radiation effect of low energy electron beam (EB) on the growth of maize, barley and soybean was investigated. Seeds of maize, barley and soybean were irradiated in the dose range of 2 to 20 kGy using EB with different energy from 150 to 250 keV. Growth promotion was observed for irradiated seeds of maize and soybean at the dose up to 10 kGy. Especially, significant promotion of root growth was observed for irradiated barley and soybean. It was also found for soybean that phytoalexin induction activity was clearly enhanced by low energy EB irradiation. (author)

  9. A Simplified Analysis Of the Brazier Effect In Composite Beams

    DEFF Research Database (Denmark)

    Damkilde, Lars; Lund, Brian

    2007-01-01

    Windturbine blades are often designed as a composite structure. The load bearing element is a composite beam, that carries the load from the tip to the root, which is connected to the rotor. The dimensions of the beam will normally vary along the beam. The primary loads on the beam is the wind load...... which is perpendicular to the axis giving bending and shear with centrifugal loadings giving axial tension. The wind pressure acts on the wing shell and is transferred to the composite beam acting as a load perpendicular to the the beam axis....

  10. Radioactive Ion Beam Production by Fast-Neutron-Induced Fission in Actinide Targets at EURISOL

    CERN Document Server

    Herrera-Martínez, Adonai

    The European Isotope Separation On-Line Radioactive Ion Beam Facility (EURISOL) is set to be the 'next-generation' European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, the production of high-intensity RIBs of specific neutron-rich isotopes is obtained by inducing fission in large-mass actinide targets. In our contribution, the use of uranium targets is shown to be advantageous to other materials, such as thorium. Therefore, in order to produce fissions in U-238 and reduce the plutonium inventory, a fast neutron energy spectrum is necessary. The large beam power required to achieve these RIB levels requires the use of a liquid proton-to-neutron converter. This article details the design parameters of the converter, with special attention to the coupled neutronics of the liquid converter and fission target. Calculations performed with the ...

  11. Beam instability induced by rf deflectors in the combiner ring of the CLIC test facility and mitigation by damped deflecting structures

    Directory of Open Access Journals (Sweden)

    David Alesini

    2011-02-01

    Full Text Available In the CTF3 (CLIC test facility 3 run of November 2007, a vertical beam instability has been found in the combiner ring during operation. After a careful analysis, the source of the instability has been identified in the vertical deflecting modes trapped in the rf deflectors and excited by the beam passage. A dedicated tracking code that includes the induced transverse wakefield and the multibunch multipassage effects has been written and the results of the beam dynamics analysis are presented in the paper. The mechanism of the instability was similar to the beam breakup in a linear accelerator or in an energy recovery linac. The results of the code allowed identifying the main key parameters driving such instability and allowed finding the main knobs to mitigate it. To completely suppress such beam instability, two new rf deflectors have been designed, constructed, and installed in the ring. In the new structures the frequency separation between the vertical and horizontal deflecting modes has been increased, changing the position of the rods inside the cells, and special antennas have been inserted to absorb the power released by the beam to the modes. The deflectors have been made in aluminum to reduce the costs and delivery time and have been successfully tested and installed in the ring. The design, the realization procedures, and the rf test results are illustrated.

  12. Effects on doppler profiles in beam-heated plasmas

    International Nuclear Information System (INIS)

    Fussmann, G.

    1988-01-01

    We analyze various effects that can influence ion temperature measurements based on Doppler broadening of impurity lines. Macroscopic effects such as inhomogeneities, plasma rotation and temporal modulations are distinguished from microscopic ones leading to species-dependent temperatures and anisotropy in the impurity distribution functions. There are turbulent effects related to the latter that can also cause deviations from thermodynamic equilibrium among light and heavy impurities. It is found that under neutral-beam-heated JET conditions, all effects should be small and influence the measured ion temperature by less than ∼ 10%. Larger influences could be expected from strongly peaked rotation profiles - for which, however, no indications are found - and high-level turbulence, which appears rather unrealistic, too. (author)

  13. Effect of Beam Oscillation on Microstructure and Mechanical Properties of AISI 316L Electron Beam Welds

    Science.gov (United States)

    Kar, Jyotirmaya; Roy, Sanat Kumar; Roy, Gour Gopal

    2017-04-01

    The properties of electron beam-welded AISI 316L stainless steel butt joints prepared with and without beam oscillation were evaluated by microstructural analysis, mechanical testing like microhardness measurements, tensile tests at room and elevated temperature 973 K (700 °C), three-point bend, and Charpy impact tests. All joints, irrespective of being prepared with or without beam oscillation, were found to be defect free. Welds produced by beam oscillation exhibited narrower fusion zone (FZ) with lathy ferrite morphology, while the weld without beam oscillation was characterized by wider FZ and skeletal ferrite morphology. During tensile tests at room and elevated temperature 973 K (700 °C), all samples fractured in the base metal (BM) and showed almost the same tensile properties as that of the BM. However, the notch tensile tests at room temperature demonstrated higher strength for joints prepared with the oscillating beam. Besides, face and root bend tests, as well as Charpy impact tests, showed higher bending strength and notch toughness, respectively, for joints prepared with beam oscillation.

  14. Principal Component Analysis in the Nonlinear Dynamics of Beams: Purification of the Signal from Noise Induced by the Nonlinearity of Beam Vibrations

    Directory of Open Access Journals (Sweden)

    A. V. Krysko

    2017-01-01

    Full Text Available The paper discusses the impact of the von Kármán type geometric nonlinearity introduced to a mathematical model of beam vibrations on the amplitude-frequency characteristics of the signal for the proposed mathematical models of beam vibrations. An attempt is made to separate vibrations of continuous mechanical systems subjected to a harmonic load from noise induced by the nonlinearity of the system by employing the principal component analysis (PCA. Straight beams lying on Winkler foundations are analysed. Differential equations are obtained based on the Bernoulli-Euler, Timoshenko, and Sheremetev-Pelekh-Levinson-Reddy hypotheses. Solutions to linear and nonlinear differential equations are found using the principal component analysis (PCA.

  15. Explicit expression for effective moment of inertia of RC beams

    Directory of Open Access Journals (Sweden)

    K.A. Patel

    Full Text Available AbstractDeflection is an important design parameter for structures subjected to service load. This paper provides an explicit expression for effective moment of inertia considering cracking, for uniformly distributed loaded reinforced concrete (RC beams. The proposed explicit expression can be used for rapid prediction of short-term deflection at service load. The explicit expression has been obtained from the trained neural network considering concrete cracking, tension stiffening and entire practical range of reinforcement. Three significant structural parameters have been identified that govern the change in effective moment of inertia and therefore deflection. These three parameters are chosen as inputs to train neural network. The training data sets for neural network are generated using finite element software ABAQUS. The explicit expression has been validated for a number of simply supported and continuous beams and it is shown that the predicted deflections have reasonable accuracy for practical purpose. A sensitivity analysis has been performed, which indicates substantial dependence of effective moment of inertia on the selected input parameters.

  16. Pigment colors printing on cotton fabrics by surface coating induced by electron beam and thermal curing

    International Nuclear Information System (INIS)

    El-Naggar, Abdel Wahab M.; Zohdy, Maged H.; Said, Hossam M.; El-Din, Mahmoud S.; Noval, Dalia M.

    2005-01-01

    Cotton fabrics were coated from one surface with different pigment colors incorporated in formulations containing ethylene glycol (EG), methyl methacrylate (MMA) and poly(methyl methacrylate) (PMMA) oligomer as a base material. The coated fabrics were exposed to various doses of accelerated electrons generated from the 1.5 MeV (25 kW) electron beam accelerator machine. In order to find the suitable conditions that afford the highest performance of pigment printing, the effect of irradiation dose and formulation composition on the color strength of the printed fabrics was investigated. The durability of the printed fabrics in terms of color fastness, tensile mechanical, crease resistance and water absorption was also studied. The results of pigment printing by electron beam irradiation was compared with the conventional thermal printing method with the same pigment colors involving the use of pastes containing binder and thickener systems. It was found that cotton fabrics printed with the pigment colors under the effect of electron beam irradiation displayed higher color strength than those fabrics printed by the conventional thermal fixation at equal pigment color ratios. In this regard, the color strength on cotton fabrics printed with the Imperon violet, blue and yellow pigment colors was 85.2, 75.4 and 91.3 in the case of printing with electron beam and 63.5, 46.0 and 50.2 in the case of thermal curing, respectively. The results showed that the pigment printing by electron beam or thermal curing improves the crease recovery and mechanical properties of cotton fabrics and exhibited comparable durability properties in terms of washing, rubbing and handling

  17. Finite geometry effect on the interaction of a hot beam with a plasma

    International Nuclear Information System (INIS)

    Shoucri, M.M.; Gagne, R.R.J.

    1977-01-01

    The effect of finite geometry on the interaction of a hot low-density beam with a uniform plasma filling a circular waveguide is studied. An expression is derived for the growth rate of the instabilities developing at the harmonic of the beam gyrofrequency, taking the finite beam gyroradius into account. The calculations are done in the quasistatic approximation. (author)

  18. Effect of Temperature Variation on Modal Frequency of Reinforced Concrete Slab and Beam in Cold Regions

    Directory of Open Access Journals (Sweden)

    Hanbing Liu

    2016-01-01

    Full Text Available Changes of modal frequencies induced by temperature variation can be more obvious than those caused by structural damage, which will lead to the false damage identification results. Therefore, quantifying the temperature effect on modal frequencies is a critical step to eliminate its interference in damage detection. Due to the nonuniform and time-dependent characteristics of temperature distribution, it is insufficient to obtain the reliable relationships between temperatures and modal frequencies using temperatures in air or at surface. In this paper, correlations between measured temperatures (air temperature, surface temperature, mean temperature, etc. and modal frequencies for the slab and beam are comparatively analyzed. And the quantitative models are constructed considering nonuniform temperature distribution. Firstly, the reinforced concrete slab and beam were constructed and placed outside the laboratory to be monitored. Secondly, the correlation coefficients between modal frequencies and three kinds of temperatures are calculated, respectively. Thirdly, simple linear regression models between mean temperature and modal frequencies are established for the slab and beam. Finally, five temperature variables are selected to construct the multiple linear regression models. Prediction results reveal that the proposed multiple linear regression models possess favorable accuracy to quantify the temperature effect on modal frequencies considering nonuniform temperature distribution.

  19. Laser marking on soda-lime glass by laser-induced backside wet etching with two-beam interference

    International Nuclear Information System (INIS)

    Nakazumi, Tomoka; Sato, Tadatake; Narazaki, Aiko; Niino, Hiroyuki

    2016-01-01

    For crack-free marking of glass materials, a beam-scanning laser-induced backside wet etching (LIBWE) process by a beam spot with a fine periodic structure was examined. The fine periodic structure was produced within a beam spot by means of a Mach–Zehnder interferometer incorporated to the optical setup for the beam-scanning LIBWE. A fine structure with a period of 9 µ m was observed within the microstructures with a diameter of ca. 40 µ m fabricated by a laser shot under double-beam irradiation, and they could be homogeneously fabricated within an area of 800  ×  800 µ m. The area filled with the microstructures, including fine periodic structures, could be observed in high contrast under a diffuse, on-axis illumination that was used in commercial QR code readers. (paper)

  20. Effect of beam oscillation on borated stainless steel electron beam welds

    Energy Technology Data Exchange (ETDEWEB)

    RajaKumar, Guttikonda [Tagore Engineering College, Chennai (India). Dept. of Mechanical Engineering; Ram, G.D. Janaki [Indian Institute of Technology (IIT), Chennai (India). Dept. of Metallurgical and Materials Engineering; Rao, S.R. Koteswara [SSN College of Engineering, Chennai (India). Mechanical Engineering

    2015-07-01

    Borated stainless steels are used in nuclear power plants to control neutron criticality in reactors as control rods, shielding material, spent fuel storage racks and transportation casks. In this study, bead on plate welds were made using gas tungsten arc welding (GTAW) and electron beam welding (EBW) processes. Electron beam welds made using beam oscillation technique exhibited higher tensile strength values compared to that of GTA welds. Electron beam welds were found to show fine dendritic microstructure while GTA welds exhibited larger dendrites. While both processes produced defect free welds, GTA welds are marked by partially melted zone (PMZ) where the hardness is low. EBW obviate the PMZ failure due to low heat input and in case of high heat input GTA welding process failure occurs in the PMZ.

  1. European developments in radiotherapy with beams of large radiobiological effectiveness.

    Science.gov (United States)

    Amaldi, Ugo; Kraft, Gerhard

    2007-01-01

    This paper reviews the European activities in the field of tumour therapy with beams which have a Radio Biological Effectiveness (RBE) larger than 1. Initially neutron beams have been used. Then charged pions promised better cure rates so that their use was pursued in the framework of the ;Piotron' project at the Paul Scherrer Institute (Switzerland). However both approaches did not meet the expectations and in the 80s the EULIMA project became the flagship of these attempts to improve the effects of the delivery of radiation doses of large RBE with respect to photons, electrons and even protons. The EULIMA ion accelerator was never built and it took more than ten years to see the approval, in Heidelberg and Pavia, of the construction of the HIT and CNAO ;dual' centres for carbon ions and protons. In 2008 they will start treating patients. The developments that brought to these construction projects are described together with the special features of these two facilities. The third European dual centre is being built by Siemens Medical Systems in Marburg, Germany, while other facilities have been approved but not yet fully financed in Wiener Neustadt (Austria), Lyon (France) and Uppsala (Sweden). Finally the collaboration activities of the European Network ENLIGHT are presented together with the recent involvements of European industries in the construction of turn-key dual centres and the development of a new accelerator concept for hadrontherapy, the ;cyclinac'.

  2. Chemical effects of heavy ion beams on organic materials

    International Nuclear Information System (INIS)

    Koizumi, Hitoshi; Ichikawa, Tsuneki; Taguchi, Mitsumasa; Kobayashi, Yasuhiko; Namba, Hideki

    2003-01-01

    Effects of ion beam irradiation on α-alanine, adipic acid and polydimethylsiloxane were examined. Stable radicals were generated in the radiolysis of solids of α-alanine and adipic acid by γ-ray, 220 MeV C ions, 350 MeV Ne ions and 175 MeV Ar ions. The G-value decreases in this order. The G-value for adipic acid decreases more than that for α-alanine. The decreases in the G-value are ascribed to high local dose in the ion tracks. Effective G-value of the radicals for γ-irradiations decreases at high doses. The local dose in the ion tracks exceeds those doses, and the G-values for the ion irradiation are hence smaller than the G-value for γ-irradiations. The difference in the dependence of the G-values for α-alanine and adipic acid on the ion beams is due to difference in the dose-yield relationship for radical formation. The high local dose in the ion tracks exceeds the gelation dose of some of polymers. Formation of gel strings of polydimethylsiloxanes generated in heavy ion tracks was observed by atomic force microscopy

  3. 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.*

  4. Relative biological effectiveness (RBE) of proton beams in radiotherapy

    International Nuclear Information System (INIS)

    Calugaru, V.

    2011-01-01

    Treatment planning in proton therapy uses a generic value for the Relative Biological Efficiency (RBE) of 1.1 relative to 60 Co gamma-rays throughout the Spread Out Bragg Peak (SOBP). We have studied the variation of the RBE at three positions in the SOBP of the 76 and 201 MeV proton beams used for cancer treatment at the Institut Curie Proton Therapy in Orsay (ICPO) in two human tumor cell lines using clonogenic cell death and the incidence of DNA double-strand breaks (DSB) as measured by pulse-field gel electrophoresis without and with endonuclease treatment to reveal clustered lesions as endpoints.The RBE for induced cell killing by the 76 MeV beam increased with depth in the SOBP. However for the 201 MeV protons it was close to that for 137 Cs gamma-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for 137 Cs g-rays, but did not depend on the proton energy or the position in the SOBP. In the second part of our work, we have shown using cell clones made deficient for known repair genes by stable or transient shRNA transfection, that the D-NHEJ pathway determine the response to protons. The response of DNA damages created in the distal part of the 76 MeV SOBP suggests that those damages belong to the class of DNA 'complex lesions' (LMDS). It also appears that the particle fluence is a major determinant of the outcome of treatment in the distal part of the SOBP. (author)

  5. Effective mutagenesis of Arabidopsis by heavy ion beam-irradiation

    International Nuclear Information System (INIS)

    Yamamoto, Y.Y.; Saito, H.; Ryuto, H.; Fukunishi, N.; Yoshida, S.; Abe, T.

    2005-01-01

    Full text: Arabidopsis researches frequently include the genetic approach, so efficient, convenient, and safe methods for mutagenesis are required. Currently, the most popular method for in house mutagenesis is application of EMS. Although this method is very effective, its base substitution-type mutations often gives leaky mutants with residual gene functions, leading some difficulty in understanding the corresponding gene functions. Heavy ion beam generated by accelerators gives highest energy transfer rates among known radiation-based mutagenesis methods including X ray, gamma ray, fast neutron, electron and proton irradiation. This feature is thought to give high frequency of the double strand break of genomic DNA and resultant short deletions, resulting frame shift-type mutations. At RIKEN Accelerator Research Facility (RARF, http://www.rarf.riken.go.jp/index-e.html), we have optimized conditions for effective mutagenesis of Arabidopsis regarding to ion species and irradiation dose, and achieved comparable mutation rates to the method with EMS. (author)

  6. A study of molecular effects in beam-foil spectroscopy

    International Nuclear Information System (INIS)

    Andresen, B.; Veje, E.

    1979-01-01

    Relative populations of ns + nd levels in hydrogen as functions of the principal quantum number n have been measured with beams of H + , H 2 + , and H 3 + impinging on thin carbon foils at 25 keV/amu and 100 keV/amu. Enhancements of 20% and 45% for dimer and trimer clusters are observed uniformly for all levels. A possible explanation in terms of screening of the Coulomb repulsion between the protons inside the foil, thus reducing the effective thickness of the foil, is given. All relative populations closely follow an nsup(P) power law with p = -4.0 and -3.7 at 25 keV/amu and 100 keV/amu, respectively, in perfect analogy with atomic collision experiments. O + /O 2 + -foil excitations at 100 keV and 155 keV show a simular molecular effect, but in reverse with a larger mean charge produced by the dimer. (Auth.)

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  8. Effect of analytical proton beam irradiation on lead-white pigments, characterized by EPR spectroscopy

    Science.gov (United States)

    Gourier, Didier; Binet, Laurent; Gonzalez, Victor; Vezin, Hervé; Touati, Nadia; Calligaro, Thomas

    2018-01-01

    Analytical techniques using proton beams with energy in the MeV range are commonly used to study archeological artefact and artistic objects. However ion beams can induce alteration of fragile materials, which is notably the case of easel paintings, limiting the use of these techniques. We used continuous wave EPR and pulse EPR spectroscopy to reveal the effect of 3 MeV proton irradiation on lead carbonates, which were extensively employed as white pigments from the antiquity to the 20th century. Two kinds of paramagnetic centers were identified in cerussite (PbCO3): the first one is CO3- radicals formed by hole trapping by CO32- ions, and the second one is NO32- radical resulting from electron trapping by NO3- impurities. Hydrocerussite (2PbCO3·Pb(OH)2) is the most darkened material under proton beam, however it exhibits no NO32- radicals and 20 times less CO3- radicals than cerussite. Consequently these paramagnetic centers are not directly responsible for the darkening of lead-white pigments. We proposed that their higher instability in hydrocerussite might be at the origin of the formation of color centers in this material.

  9. Effect of helium ion beam treatment on wet etching of silicon dioxide

    Science.gov (United States)

    Petrov, Yu. V.; Grigoryev, E. A.; Sharov, T. V.; Baraban, A. P.

    2018-03-01

    We investigated the effect of helium ion beam treatment on the etching rate of silicon dioxide in a water based solution of hydrofluoric acid. A 460-nm-thick silicon dioxide film on silicon was irradiated with helium ions having energies of 20 keV and 30 keV with ion fluences ranging from 1014 cm-2 to 1017 cm-2. The dependence of the etching rate on depth was obtained and compared with the depth distribution of ion-induced defects, which was obtained from numerical simulation. Irradiation with helium ions results in an increase of the etching rate of silicon dioxide. The dependence of the etching rate on the calculated concentration of ion-induced defects is described.

  10. The tensile effect on crack formation in single crystal silicon irradiated by intense pulsed ion beam

    Science.gov (United States)

    Liang, Guoying; Shen, Jie; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Yan, Sha; Zhang, Xiaofu; Yu, Xiao; Le, Xiaoyun

    2017-10-01

    Improving antifatigue performance of silicon substrate is very important for the development of semiconductor industry. The cracking behavior of silicon under intense pulsed ion beam irradiation was studied by numerical simulation in order to understand the mechanism of induced surface peeling observed by experimental means. Using molecular dynamics simulation based on Stillinger Weber potential, tensile effect on crack growth and propagation in single crystal silicon was investigated. Simulation results reveal that stress-strain curves of single crystal silicon at a constant strain rate can be divided into three stages, which are not similar to metal stress-strain curves; different tensile load velocities induce difference of single silicon crack formation speed; the layered stress results in crack formation in single crystal silicon. It is concluded that the crack growth and propagation is more sensitive to strain rate, tensile load velocity, stress distribution in single crystal silicon.

  11. The quantum measurement effect of interaction without interaction for an atomic beam

    Science.gov (United States)

    Huang, Yong-Yi

    When an atomic beam collectively and harmonically vibrates perpendicular to the wave vector of the beam, the number of atoms reaching the atomic detector will have a vibrant factor Δt / T if the measurement time interval Δt is shorter than the period T. This new quantum mechanical measurement effect for an atomic beam is called interaction without interaction: though the translational motion of the atomic beam does not interact with its collective and transverse harmonic vibration, the latter will have an effect on the measured number of atoms associated with the former. From the new measurement effect the classical harmonic vibration's period is evaluated. We give a clear physical picture and a satisfactory physical interpretation for the measurement effect based on the Copenhagen interpretation of quantum mechanics. We present an experimental proposal to verify this measurement effect for an ion beam instead of an atomic beam.

  12. 3D Simulations of Space Charge Effects in Particle Beams

    International Nuclear Information System (INIS)

    Adelmann, A.

    2002-10-01

    For the first time, it is possible to calculate the complicated three-dimensional proton accelerator structures at the Paul Scherrer Institut (PSI). Under consideration are external and self effects, arising from guiding and space-charge forces. This thesis has as its theme the design, implementation and validation of a tracking program for charged particles in accelerator structures. This work form part of the discipline of Computational Science and Engineering (CSE), more specifically in computational accelerator modelling. The physical model is based on the collisionless Vlasov-Maxwell theory, justified by the low density (∼ 10 9 protons/cm 3 ) of the beam and of the residual gas. The probability of large angle scattering between the protons and the residual gas is then sufficiently low, as can be estimated by considering the mean free path and the total distance a particle travels in the accelerator structure. (author)

  13. 3D Simulations of Space Charge Effects in Particle Beams

    Energy Technology Data Exchange (ETDEWEB)

    Adelmann, A

    2002-10-01

    For the first time, it is possible to calculate the complicated three-dimensional proton accelerator structures at the Paul Scherrer Institut (PSI). Under consideration are external and self effects, arising from guiding and space-charge forces. This thesis has as its theme the design, implementation and validation of a tracking program for charged particles in accelerator structures. This work form part of the discipline of Computational Science and Engineering (CSE), more specifically in computational accelerator modelling. The physical model is based on the collisionless Vlasov-Maxwell theory, justified by the low density ({approx} 10{sup 9} protons/cm{sup 3}) of the beam and of the residual gas. The probability of large angle scattering between the protons and the residual gas is then sufficiently low, as can be estimated by considering the mean free path and the total distance a particle travels in the accelerator structure. (author)

  14. Grafting and polymerisation processes induced by electron beams for antistatic treatment and hydrophilation of polyester textiles with polyethylene glycol dimethacrylates

    International Nuclear Information System (INIS)

    Clauss, B.

    1986-01-01

    According to dosimetric measurements on various textiles, the penetration behaviour of accelerated electrons in textile substrates corresponds to that found for homogeneous foils. A clear relationship is given between depth of penetration and degree of ionisation. Infrared spectroscopic investigation of the homopolymerisation of polyethylene glycol dimethacrylates induced by radiation makes it clear that cross-linked polymers are formed if the dose is increased. This effect can be supported by the addition of multi-functional acrylates. The measurement of bending stiffness proved to be a useful method for distinguishing between homopolymers and grafted polymers. It was found during comparative measurements on glass fibre and polyester weaves that methacrylates can only be changed to polyesters at a high dose (100 kGy). In the treatment of polyester textiles induced by electron beams, the length of the ethylene glycol chain in the monomer proved to be an important factor. With increasing length of chain, better degrees of fixing, better antistatic effects and better cross-linking properties are found. The limit is reached at a chain length of 12. The appropriate monomer (polyethylene glycol-600-dimethacrylate) gives surfaces resistances of 10 11 ohms. The spread of a drop of water on the textile surface occurs in less than 2 seconds. The antistatic effect of the polymer is based on water adsorption at the textile surface. (orig.) [de

  15. European developments in radiotherapy with beams of large radiobiological effectiveness

    International Nuclear Information System (INIS)

    Amaldi, U.; Kraft, G.

    2007-01-01

    This paper reviews the European activities in the field of tumour therapy with beams which have a Radio Biological Effectiveness (RBE) larger than 1. Initially neutron beams have been used. Then charged pions promised better cure rates so that their use was pursued in the framework of the 'Piotron' project at the Paul Scherrer Institute (Switzerland). However both approaches did not meet the expectations and in the 80s the European Light Ion Medical Accelerator (EULIMA) project became the flagship of these attempts to improve the effects of the delivery of radiation doses of large RBE with respect to photons, electrons and even protons. The EULIMA ion accelerator was never built and it took more than ten years to see the approval, in Heidelberg and Pavia, of the construction of the Heidelberg Ion Therapy Centre (HIT) and National Centre for Oncological Hadrontherapy (CNAO) 'dual' centres for carbon ions and protons. In 2008 they will start treating patients. The developments that brought to these construction projects are described together with the special features of these two facilities. The third European dual centre is being built by Siemens Medical Systems in Marburg, Germany, while other facilities have been approved but not yet fully financed in Wiener Neustadt (Austria), Lyon (France) and Uppsala (Sweden). Finally the collaboration activities of the European Network the European Network for Light Ion Therapy (ENLIGHT) are presented together with the recent involvements of European industries in the construction of turn-key dual centres and the development of a new accelerator concept for hadrontherapy, the 'cyclinac'. (author)

  16. THE EFFECT OF FLY ASH ON FLEXURAL CAPACITY CONCRETE BEAMS

    OpenAIRE

    Amir Mohammad Amiri; Amin Olfati; Shima Najjar; Peyman Beiranvand; M.H. Naseri Fard

    2016-01-01

    This paper presents the flexural response of Reinforced Geopolymer Concrete (RGPC) beam. A commercial finite element (FE) software ABAQUS has been used to perform a structural behavior of RGPC beam. Using parameters such: stress, strain, Young’s modulus, and Poisson’s ratio obtained from experimental results, a beam model has been simulated in ABAQUS. The results from experimental test and ABAQUS simulation were compared. Due to friction forces at the supports and loading rollers; slip occurr...

  17. Various categories of defects after surface alloying induced by high current pulsed electron beam irradiation

    International Nuclear Information System (INIS)

    Luo, Dian; Tang, Guangze; Ma, Xinxin; Gu, Le; Sun, Mingren; Wang, Liqin

    2015-01-01

    Highlights: • Four kinds of defects are found during surface alloying by high current electron beam. • Exploring the mechanism how these defects appear after irradiation. • Increasing pulsing cycles will help to get good surface quality. • Choosing proper energy density will increase surface quality. - Abstract: High current pulsed electron beam (HCPEB) is an attractive advanced materials processing method which could highly increase the mechanical properties and corrosion resistance. However, how to eliminate different kinds of defects during irradiation by HCPEB especially in condition of adding new elements is a challenging task. In the present research, the titanium and TaNb-TiW composite films was deposited on the carburizing steel (SAE9310 steel) by DC magnetron sputtering before irradiation. The process of surface alloying was induced by HCPEB with pulse duration of 2.5 μs and energy density ranging from 3 to 9 J/cm 2 . Investigation of the microstructure indicated that there were several forms of defects after irradiation, such as surface unwetting, surface eruption, micro-cracks and layering. How the defects formed was explained by the results of electron microscopy and energy dispersive spectroscopy. The results also revealed that proper energy density (∼6 J/cm 2 ) and multi-number of irradiation (≥50 times) contributed to high quality of alloyed layers after irradiation

  18. Resonant antineutrino induced electron capture with low energy bound-beta beams

    Energy Technology Data Exchange (ETDEWEB)

    Oldeman, R.G.C.; Meloni, M.; Saitta, B. [Universita degli Studi di Cagliari (Italy); INFN, Sezione di Cagliari, Dipartimento di Fisica, Cagliari (Italy)

    2010-01-15

    Antineutrino induced electron capture is a resonant process that can have a large cross-section for beams of monochromatic antineutrinos. We calculate the cross-section of this process and investigate an experimental setup where monochromatic antineutrinos are produced from the bound-beta decay of fully ionized radioactive atoms in a storage ring. If the energy between the source and the target is well matched, the cross-sections can be significantly larger than the cross-sections of commonly used non-resonant processes. The rate that can be achieved at a small distance between the source and two targets of 10{sup 3} kg is up to one interaction per 8.3.10{sup 18} decaying atoms. For a source-target distance corresponding to the first atmospheric neutrino oscillation maximum, the largest rate is one interaction per 3.2.10{sup 21} decaying atoms, provided that extremely stringent monochromaticity conditions (10{sup -7} or better) are achieved in future ion beams. (orig.)

  19. Electron beam induced water-soluble silk fibroin nanoparticles as a natural antioxidant and reducing agent for a green synthesis of gold nanocolloid

    Science.gov (United States)

    Wongkrongsak, Soraya; Tangthong, Theeranan; Pasanphan, Wanvimol

    2016-01-01

    The research proposes a novel water-soluble silk fibroin nanoparticles (WSSF-NPs) created by electron beam irradiation. In this report, we demonstrate the effects of electron beam irradiation doses ranging from 1 to 30 kGy on the molecular weight (MW), nanostructure formation, antioxidant activity and reducing power of the WSSF-NPs. Electron beam-induced degradation of SF causing MW reduction from 250 to 37 kDa. Chemical characteristic functions of SF still remained after exposing to electron beam. The WSSF-NPs with the MW of 37 kDa exhibited spherical morphology with a nanoscaled size of 40 nm. Antioxidant activities and reducing powers were investigated using 2,2-diphenyl-1-picrylhryl free radical (DPPH•) scavenging activity and ferric reducing antioxidant power (FRAP) assays, respectively. The WSSF-NPs showed greater antioxidant activity and reducing power than non-irradiated SF. By increasing their antioxidant and reducing power efficiencies, WSSF-NPs potentially created gold nanocolloid. WSSF-NPs produced by electron beam irradiation would be a great merit for the uses as a natural antioxidant additive and a green reducing agent in biomedical, cosmetic and food applications.

  20. Focused-ion-beam induced interfacial intermixing of magnetic bilayers for nanoscale control of magnetic properties

    International Nuclear Information System (INIS)

    Burn, D M; Atkinson, D; Hase, T P A

    2014-01-01

    Modification of the magnetic properties in a thin-film ferromagnetic/non-magnetic bilayer system by low-dose focused ion-beam (FIB) induced intermixing is demonstrated. The highly localized capability of FIB may be used to locally control magnetic behaviour at the nanoscale. The magnetic, electronic and structural properties of NiFe/Au bilayers were investigated as a function of the interfacial structure that was actively modified using focused Ga + ion irradiation. Experimental work used MOKE, SQUID, XMCD as well as magnetoresistance measurements to determine the magnetic behavior and grazing incidence x-ray reflectivity to elucidate the interfacial structure. Interfacial intermixing, induced by low-dose irradiation, is shown to lead to complex changes in the magnetic behavior that are associated with monotonic structural evolution of the interface. This behavior may be explained by changes in the local atomic environment within the interface region resulting in a combination of processes including the loss of moment on Ni and Fe, an induced moment on Au and modifications to the spin-orbit coupling between Au and NiFe. (paper)

  1. Electron beam-induced Fries rearrangement of arylsulfonamides and arylsulfonates in the crystalline state

    International Nuclear Information System (INIS)

    Kato, Jun; Yuasa, Kanako; Yamashita, Takashi; Maekawa, Yasunari; Yoshida, Masaru

    2003-01-01

    Electron beam (EB)-induced reactions of organic crystals containing a carbonyl or a sulfonyl group have been investigated. The EB irradiation of benzenesulfonanilide (BSA) in the crystalline state induced the Fries rearrangement to yield o- and p-aminodiphenylsulfones as the major and minor products, respectively. Several BSA derivatives also had the same reactivity, while benzanilide as the corresponding carbonyl compound did not rearrange under the same conditions. These results showed that the S-N bond could be cleaved selectively by EB irradiation but the C-N bond couldn't, which could take place only by the use of EB. The EB irradiation of phenyl p-toluenesulfonate (PTS) crystals gave not only Fries-type products but also the oxidation product. By comparing with the reactivity of liquid phenyl benzenesulfonate, the EB-induced Fries rearrangement was suggested to proceed under crystalline lattice restrictions. The G-values of arylsulfonamides and arylsulfonates were in the range of ca. 1-2 molecules per 100 eV of absorbed energy. This is the first Fries rearrangement via direct excitation by EB irradiation. (author)

  2. Investigation of the combined effect of neutron irradiation and electron beam exposure on pure tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Van Renterghem, W., E-mail: wvrenter@sckcen.be; Uytdenhouwen, I., E-mail: iuytdenh@sckcen.be

    2016-08-15

    Pure tungsten samples were neutron irradiated in the BR2 reactor of SCK·CEN to fluences of 1.47 × 10{sup 20} n/cm{sup 2} and 4.74 × 10{sup 20} n/cm{sup 2} at 300 °C under Helium atmosphere and exposed to the electron beam of the Judith 1 installation The effect of these treatments on the defect structure was studied with transmission electron microscopy. In the irradiated samples the defect structure in the bulk is compared to the structure at the surface. The neutron irradiation created a large amount of a/2‹111› type dislocation loops forming dislocation rafts. The loop density increased from 8.5 × 10{sup 21}/m³ to 9 × 10{sup 22}/m³ with increasing dose, while the loop size decreased from 5.2 nm to 3.5 nm. The electron beam exposure induced significant annealing of the defects and almost all of the dislocation loops were removed. The number of line dislocations in that area increased as a result of the thermal stresses from the thermal shock. - Highlights: • Neutron irradiated and electron beam exposed tungsten samples were studied with transmission electron microscopy. • Neutron irradiation creates dislocation loops and rafts, while voids are created at higher irradiation dose. • No precipitates of transmutation products were found under these low dose irradiation conditions. • Electron beam exposure annihilates the dislocation loops and rafts.

  3. Calculating variations in biological effectiveness for a 62 MeV proton beam

    Directory of Open Access Journals (Sweden)

    Mario Pietro Carante

    2016-04-01

    Full Text Available A biophysical model of radiation-induced cell death and chromosome aberrations (called BIANCA, BIophysical ANalysis of Cell death and chromosome Aberrations was further developed and applied to therapeutic protons. The model assumes a pivotal role of DNA cluster damage, which can lead to clonogenic cell death following three main steps: i a DNA Cluster Lesion (CL produces two independent chromosome fragments; ii fragment mis-rejoining within a threshold distance d gives rise to chromosome aberrations; iii certain aberration types (dicentrics, rings and large deletions lead to clonogenic inactivation. The yield of CLs and the probability, f, that a chromosome fragment remains un-rejoined even if other fragment(s are present within d, were adjustable parameters. The model, implemented as a MC code providing simulated dose-responses directly comparable with experimental data, was applied to pristine and modulated Bragg peaks of the proton beam used to treat eye melanoma at INFN-LNS in Catania, Italy. Experimental survival curves for AG01522 cells exposed to the Catania beam were reproduced, supporting the model assumptions. Furthermore, cell death and chromosome aberrations at different depths along a SOBP (Spread-Out Bragg Peak dose profile were predicted. Both endpoints showed an increase along the plateau, and high levels of damage were found also beyond the distal dose fall-off, due to low-energy protons. Cell death and chromosome aberrations were also predicted for V79 cells, in the same irradiation scenario as that used for AG01522 cells. In line with other studies, this work indicated that assuming a constant RBE along a proton SOBP may be sub-optimal. Furthermore, it provided qualitative and quantitative evaluations of the dependence of the beam effectiveness on the considered endpoint and dose. More generally, this work represents an example of therapeutic beam characterization avoiding the use of experimental RBE values, which can be

  4. The role of electron-stimulated desorption in focused electron beam induced deposition

    DEFF Research Database (Denmark)

    van Dorp, Willem F.; Hansen, Thomas Willum; Wagner, Jakob Birkedal

    2013-01-01

    We present the results of our study about the deposition rate of focused electron beam induced processing (FEBIP) as a function of the substrate temperature with the substrate being an electron-transparent amorphous carbon membrane. When W(CO)6 is used as a precursor it is observed that the growth...... experiments compared to literature values is consistent with earlier findings by other authors. The discrepancy is attributed to electron-stimulated desorption, which is known to occur during electron irradiation. The data suggest that, of the W(CO)6 molecules that are affected by the electron irradiation......, the majority desorbs from the surface rather than dissociates to contribute to the deposit. It is important to take this into account during FEBIP experiments, for instance when determining fundamental process parameters such as the activation energy for desorption....

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  6. Temperature dependence of the amorphization process induced by ion beam mixing in a metallic bilayer

    International Nuclear Information System (INIS)

    Thome, L.; Benkoulal, T.; Jagielski, J.

    1994-01-01

    Amorphization induced by ion beam mixing has been investigated via Rutherford backscattering spectrometry and channelling experiments on a Zr/Ni bilayer as a function of the bombardment temperature. Irradiation was performed with various noble gas ions (Ne, Ar, Kr and Xe) in a temperature range between 100K and 500K. The results show that both the mixing and the amorphization processes are influenced by the temperature at which ion bombardment is performed. The mixing rate is much higher at 500K than at low temperature; conversely, the amorphization rate decreases as the temperature increases. The composition of the amorphous phase formed during mixing was also demonstrated to depend on the irradiation temperature. ((orig.))

  7. Observation of whispering gallery modes through electron beam-induced deposition.

    Science.gov (United States)

    Timmermans, F J; Chang, L; van Wolferen, H A G M; Lenferink, A T M; Otto, C

    2017-04-01

    Surprisingly intense spectra of whispering gallery modes were observed in polymer microbeads after illumination with electrons in a scanning electron microscope and subsequent laser illumination and spectral analysis. It will be proposed that whispering gallery mode resonances became visible after local deposition of hydrocarbon material through electron beam-induced deposition. The illumination of deposited material with a near infrared laser generates a broad light spectrum, acting as a local "white light" source that couples, for favorable wavelengths, with the WGM sustained by the sphere. This facilitates a spectroscopic analysis of the WGM and provides the Q-factor and free spectral range for all investigated particles. The analysis by an integrated SEM and Raman micro-spectrometer offers a direct approach to the analysis of WGM resonators as they are, for instance, used in sensing.

  8. Experimental setup and first measurement of DNA damage induced along and around an antiproton beam

    DEFF Research Database (Denmark)

    Kavanagh, J. N.; Currell, F. J.; Timson, D. J.

    2010-01-01

    a further enhancement due to their annihilation at the end of the path. The work presented here aimed to establish and validate an experimental procedure for the quantification of plasmid and genomic DNA damage resulting from antiproton exposure. Immunocytochemistry was used to assess DNA damage in directly......Radiotherapy employs ionizing radiation to induce lethal DNA lesions in cancer cells while minimizing damage to healthy tissues. Due to their pattern of energy deposition, better therapeutic outcomes can, in theory, be achieved with ions compared to photons. Antiprotons have been proposed to offer...... and indirectly exposed human fibroblasts irradiated in both plateau and Bragg peak regions of a 126 MeV antiproton beam at CERN. Cells were stained post irradiation with an anti-γ-H2AX antibody. Quantification of the γ-H2AX foci-dose relationship is consistent with a linear increase in the Bragg peak region...

  9. Dose Rate Effects on The Radiation Oxidation of Polyethylene: Electron Beam vs Gamma Irradiation

    International Nuclear Information System (INIS)

    Faucitano, A.

    2006-01-01

    The yields and spatial distribution of the oxidation products stemming from the oxidation of LLPE films induced by 60-Co gamma and by irradiation with 300 kev, 0.3 mA electrons in the dose range 0.04 kGy/h - 0.6 kGy/h (gamma) and at 1.5 kGy/hr ( e-beam) have been determined by applying a methodology involving FTIR microscopy (carbonyl products, resolution 10 μ), iodometric analysis (peroxides). The FTIR and EPR spectroscopies coupled with the multilayer technique (resolution 25 μ) were also employed for carrying on measurements of the film depth profiles of peroxyl radicals and their alky radicals precursors, radical decay kinetics, 'free' and ' bound' hydroperoxides and alcools. With gamma radiations the products yields are enhanced following the decrease of the dose rate from 0.7 to 0.04 kGy/h without substantial effect on the film depth distributions which appear rather uniform. Using e-beam (dose rate 1.5 kGy/h) a low level concentration limit is attained confined within the first 50 μ which is about 1 order of magnitude smaller as compared to gamma. The mechanistic implications inherent to the experimental results as well as the practical consequences related to the use of radiooxidation as a tool for inducing graft copolymerization reactions are discussed

  10. Shallow-trap-induced positive absorptive two-beam coupling 'gain' and light-induced transparency in nominally undoped barium titanate

    Science.gov (United States)

    Garrett, M. H.; Tayebati, P.; Chang, J. Y.; Jenssen, H. P.; Warde, C.

    1992-01-01

    The asymmetry of beam coupling with respect to the orientation of the polar axis in a nominally undoped barium titanate crystal is used to determine the electro-optic and absorptive 'gain' in the usual beam-coupling geometry. For small grating wave vectors, the electrooptic coupling vanishes but the absorptive coupling remains finite and positive. Positive absorptive coupling at small grating wave vectors is correlated with the light-induced transparency of the crystal described herein. The intensity and grating wave vector dependence of the electrooptic and absorptive coupling, and the light-induced transparency are consistent with a model incorporating deep and shallow levels.

  11. Ion-beam induced transformations in nanoscale multilayers: Evolution of clusters with preferred length scales

    Science.gov (United States)

    Bera, S.; Satpati, B.; Goswami, D. K.; Bhattacharjee, K.; Satyam, P. V.; Dev, B. N.

    2006-04-01

    Ion-irradiation-induced modifications of a periodic Pt/C multilayer system containing a small amount of Fe have been analyzed by transmission electron microscopy and grazing incidence x-ray diffraction (GIXRD) studies. The multilayer stack with 16 Pt/C layer pairs (period of 4.23 nm) was fabricated on a glass substrate. A 2 MeV Au2+ ion beam was rastered on the sample to obtain uniformly irradiated strips with fluences from 1×1014 to 1×1015 ions/cm2. Ion irradiation has been found to cause preferential migration of Fe towards Pt layers [Bera et al., Nucl. Instrum. Methods Phys. Res. B 212, 530 (2003)]. Cross-sectional transmission electron microscopy (XTEM) shows considerable atomic redistribution for irradiation at the highest ion fluence (1×1015 ions/cm2). This structure is composed of small clusters. Phase separation and cluster formation processes are discussed. Periodic multilayers have periodicity only in the direction normal to the multilayer surface. However, Fourier transform (FT) of the XTEM images of the sample irradiated at the highest fluence shows extra off-normal Fourier components of superlattice periodicities arising due to ion irradiation. These extra spots in the FT are due to preferential length scales in intercluster separation in three dimensions. With a proper understanding of this phenomenon it may be possible to fabricate useful three-dimensional self-assembled structures of nanoclusters. Our high resolution transmission electron microscopy and GIXRD results reveal the formation of an FePt alloy. As FePt is a magnetic alloy, our observation raises the possibility of fabrication of ion-beam induced magnetic nanocluster lattices.

  12. Ion-beam induced transformations in nanoscale multilayers: Evolution of clusters with preferred length scales

    International Nuclear Information System (INIS)

    Bera, S.; Satpati, B.; Goswami, D. K.; Bhattacharjee, K.; Satyam, P. V.; Dev, B. N.

    2006-01-01

    Ion-irradiation-induced modifications of a periodic Pt/C multilayer system containing a small amount of Fe have been analyzed by transmission electron microscopy and grazing incidence x-ray diffraction (GIXRD) studies. The multilayer stack with 16 Pt/C layer pairs (period of 4.23 nm) was fabricated on a glass substrate. A 2 MeV Au 2+ ion beam was rastered on the sample to obtain uniformly irradiated strips with fluences from 1x10 14 to 1x10 15 ions/cm 2 . Ion irradiation has been found to cause preferential migration of Fe towards Pt layers [Bera et al., Nucl. Instrum. Methods Phys. Res. B 212, 530 (2003)]. Cross-sectional transmission electron microscopy (XTEM) shows considerable atomic redistribution for irradiation at the highest ion fluence (1x10 15 ions/cm 2 ). This structure is composed of small clusters. Phase separation and cluster formation processes are discussed. Periodic multilayers have periodicity only in the direction normal to the multilayer surface. However, Fourier transform (FT) of the XTEM images of the sample irradiated at the highest fluence shows extra off-normal Fourier components of superlattice periodicities arising due to ion irradiation. These extra spots in the FT are due to preferential length scales in intercluster separation in three dimensions. With a proper understanding of this phenomenon it may be possible to fabricate useful three-dimensional self-assembled structures of nanoclusters. Our high resolution transmission electron microscopy and GIXRD results reveal the formation of an FePt alloy. As FePt is a magnetic alloy, our observation raises the possibility of fabrication of ion-beam induced magnetic nanocluster lattices

  13. Radiation-Induced Graft Polymerization: Gamma Radiation and Electron Beam Technology for Materials Development

    International Nuclear Information System (INIS)

    Madrid, Jordan F.; Cabalar, Patrick Jay; Lopez, Girlie Eunice; Abad, Lucille V.

    2015-01-01

    The formation of functional hybrid materials by attaching polymer chains with advantageous tailored properties to the surface of a base polymer with desirable bulk character is an attractive application of graft copolymerization. Radiation-induced graft polymerization (RIGP) has been a popular approach for surface modification of polymers because of its merits over conventional chemical processes. RIGP, which proceeds primarily via free radical polymerization process, has the advantages such as simplicity, low cost, control over process and adjustment of the materials composition and structure. RIGP can be performed using either electron beam or gamma radiation and it can be applied to both synthetic and natural polymers. These merits make RIGP a popular research topic worldwide. Moreover, the materials synthesized and produced via RIGP has found applications, and were proposed to produce continuous impact, in the fields of medicine, agriculture, pollution remediation, rare earth and valuable metals recovery, fuel cell membrane synthesis and catalysis to name a few. From 2012 our group has performed electron beam and gamma radiation-induced graft polymerization of various monomers onto polymers of natural and synthetic origins (e.g. monomers - glycidyl methacrylate, styrene, acrylonitrile, N,N-dimethylaminoethyl methacrylate; base polymers – polyethylene/polypropylene nonwoven fabric, polypropylene nonwoven fabric pineapple fibers, cellulose nonwoven fabric microcrystalline cellulose). We tested these grafted materials for heavy metals (Pb, Ni, Cu) and organic molecule removal from aqueous solutions and E. coli activity (using reversible addition fragmentation chain transfer RAFT mediated grafting). The results clearly showed the success of materials modified via FIGP in these applications. Currently, we are studying the applications of grafted materials on treatment of waste waters from tanning industry, value addition to abaca nonwoven fabrics cell sheet

  14. Preliminary study about frequencies of unstable chromosome alterations induced by gamma beam and neutron-gamma mixed field

    International Nuclear Information System (INIS)

    Mendes, Mariana E.; Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

    2011-01-01

    The estimate on approximate dose in exposed individual can be made through conventional cytogenetic analysis of dicentric, this technique has been used to support physical dosimetry. It is important to estimate the absorbed dose in case of accidents with the aim of developing an appropriate treatment and biological dosimetry can be very useful in case where the dosimetry is unavailable. Exposure to gamma and neutron radiation leads to the same biological effects such as chromosomal alterations and cancer. However, neutrons cause more genetic damage, such as mutation or more structural damage, such as chromosome alterations. The aim of research is to compare frequencies of unstable chromosome alterations induced by a gamma beam with those from neutron-gamma mixed field. Two blood samples were obtained from one healthy donor and irradiated at different sources. The first sample was exposed to mixed field neutron-gamma sources 241 AmBe at the Neutron Calibration Laboratory (NCL - CRCN/NE - PE - Brazil) and the second one was exposed to 137 Cs gamma rays at 137 Cs Laboratory (CRCN/NE - PE - Brazil), both exposures resulting in an absorbed dose of 0.66Gy. Mitotic metaphase cells were obtained by lymphocyte culture for chromosomal analysis and slides were stained with Giemsa 5%. These preliminary results showed a similarity in associated dicentrics frequency per cell (0.041 and 0.048) after 137 Cs and 241 AmBe sources irradiations, respectively. However, it was not observed centric rings frequency per cell (0.0 and 0.027). This study will be continue to verify the frequencies of unstable chromosome alterations induced by only gamma beam and neutron-gamma mixed field. (author)

  15. Preliminary study about frequencies of unstable chromosome alterations induced by gamma beam and neutron-gamma mixed field

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Mariana E.; Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Calixto, Merilane S.; Santos, Neide [Universidade Federal de Pernanmbuco (CCB/UFPE), Recife, PE (Brazil). Centro de Ciencias Biologicas. Dept. de Genetica

    2011-07-01

    The estimate on approximate dose in exposed individual can be made through conventional cytogenetic analysis of dicentric, this technique has been used to support physical dosimetry. It is important to estimate the absorbed dose in case of accidents with the aim of developing an appropriate treatment and biological dosimetry can be very useful in case where the dosimetry is unavailable. Exposure to gamma and neutron radiation leads to the same biological effects such as chromosomal alterations and cancer. However, neutrons cause more genetic damage, such as mutation or more structural damage, such as chromosome alterations. The aim of research is to compare frequencies of unstable chromosome alterations induced by a gamma beam with those from neutron-gamma mixed field. Two blood samples were obtained from one healthy donor and irradiated at different sources. The first sample was exposed to mixed field neutron-gamma sources {sup 241}AmBe at the Neutron Calibration Laboratory (NCL - CRCN/NE - PE - Brazil) and the second one was exposed to {sup 137}Cs gamma rays at {sup 137}Cs Laboratory (CRCN/NE - PE - Brazil), both exposures resulting in an absorbed dose of 0.66Gy. Mitotic metaphase cells were obtained by lymphocyte culture for chromosomal analysis and slides were stained with Giemsa 5%. These preliminary results showed a similarity in associated dicentrics frequency per cell (0.041 and 0.048) after {sup 137}Cs and {sup 241}AmBe sources irradiations, respectively. However, it was not observed centric rings frequency per cell (0.0 and 0.027). This study will be continue to verify the frequencies of unstable chromosome alterations induced by only gamma beam and neutron-gamma mixed field. (author)

  16. Resonant Effects in Neutral beam Moderation at TJ-II

    International Nuclear Information System (INIS)

    Guasp, J.; Liniers, M.; Fuentes, C.

    1999-01-01

    The structure of fast ion losses in neutral beam moderation at TJ-II is analysed theoretically, in particular the influence of resonant effects and the radial electric field dependence. The direct losses show strong resonant effects when the ratio of the poloidal and toroidal rotation velocities pass near the values -4/3, -2 or 0. These effects are visible as strong maxima on the loss fractions and also as characteristic trajectory behaviours. The delayed losses present resonant effects also, generally at intermediate energies (5 to 20 KeV for 40 keV injection). Near the resonances the population of passing particles in these losses is very high and the loss fraction can equal or even surpass the direct losses. In these delayed losses the particles concentrate along vertical strips on the loss cone diagrams of roughly constant parallel velocity. This parallel velocity increases with the electric field, the loss maxima are reached usually when the pitch and energy of these strips are near the initial injection values. The trapped particle population in these delayed losses is maximal at null electric and decreases with the field intensity for both potential signs. The corresponding final energies are usually low (1 to 5 keV). Except at extreme potentials, where the -4 resonance can appear, no resonant effects are observed for this population. The resonance ordering is similar for all configurations and follows reasonably the predictions of a simple model. The extreme configurations are dominated by the effects of the 0 and -2 resonances, giving very high loss fractions even for null electric field. In contrast the intermediate configurations, near the Reference one, do not present resonant effects and the losses are moderate at low potentials. Only above 2000 v the resonant effects start to appear. (Author) 11 refs

  17. Quantification of the Relative Biological Effectiveness for Ion Beam Radiotherapy: Direct Experimental Comparison of Proton and Carbon Ion Beams and a Novel Approach for Treatment Planning

    International Nuclear Information System (INIS)

    Elsaesser, Thilo; Weyrather, Wilma K.; Friedrich, Thomas; Durante, Marco; Iancu, Gheorghe; Kraemer, Michael; Kragl, Gabriele; Brons, Stephan; Winter, Marcus; Weber, Klaus-Josef; Scholz, Michael

    2010-01-01

    Purpose: To present the first direct experimental in vitro comparison of the biological effectiveness of range-equivalent protons and carbon ion beams for Chinese hamster ovary cells exposed in a three-dimensional phantom using a pencil beam scanning technique and to compare the experimental data with a novel biophysical model. Methods and Materials: Cell survival was measured in the phantom after irradiation with two opposing fields, thus mimicking the typical patient treatment scenario. The novel biophysical model represents a substantial extension of the local effect model, previously used for treatment planning in carbon ion therapy for more than 400 patients, and potentially can be used to predict effectiveness of all ion species relevant for radiotherapy. A key feature of the new approach is the more sophisticated consideration of spatially correlated damage induced by ion irradiation. Results: The experimental data obtained for Chinese hamster ovary cells clearly demonstrate that higher cell killing is achieved in the target region with carbon ions as compared with protons when the effects in the entrance channel are comparable. The model predictions demonstrate agreement with these experimental data and with data obtained with helium ions under similar conditions. Good agreement is also achieved with relative biological effectiveness values reported in the literature for other cell lines for monoenergetic proton, helium, and carbon ions. Conclusion: Both the experimental data and the new modeling approach are supportive of the advantages of carbon ions as compared with protons for treatment-like field configurations. Because the model predicts the effectiveness for several ion species with similar accuracy, it represents a powerful tool for further optimization and utilization of the potential of ion beams in tumor therapy.

  18. Linear acoustic waves induced in a cylindrical solid target by particle beam in e--e+ colliders

    International Nuclear Information System (INIS)

    Adeyemi, Olufemi Segun

    2015-06-01

    A future high energy lepton collider will demand high luminosities to achieve its physics goals. For the electron-positron linear collider, the generation of the desired amount of positrons is a non-trivial problem: the positron production target has to survive huge amounts of energy deposited by the bombardment of intense beams of electrons or photons. This causes a rapid increase of the temperature in the target within a very short time period. The resulting deformation due to the induced pressure waves can substantially shorten the operating life-span of the target material. In this work, we study linear effects of induced stress in a solid target through pressure acoustic waves using continuum mechanics. We derived analytical solutions for different cases and imposed different boundary conditions. The application of the model to the SLC positron target gave us the results which are in agreement with the existing literature. In a similar manner, we investigated the effect of single and multiple photon bunches on the conversion target for ILC.

  19. Effective and efficient method of calculating Bessel beam fields

    CSIR Research Space (South Africa)

    Litvin, IA

    2005-01-01

    Full Text Available beams for SRS applications. However, to model the self reconstruction property of Bessel beams, it is necessary to calculate the field at all points in space before and after the obstacle – a computationally intensive task give the large spatial...

  20. Effect of ion beam irradiation on metal particle doped polymer ...

    Indian Academy of Sciences (India)

    that the surface roughness increases after ion beam irradiation. Keywords. Composite materials; ion beam irradiation; dielectric properties; X-ray diffraction. 1. Introduction. Various metal fillers were incorporated in polymers to pro- duce novel functionalized composites, which have found extensive applications, such as ...

  1. Duration of Load Effects on Different Sized Timber Beams

    DEFF Research Database (Denmark)

    Andreasen, Lotte; Hoffmeyer, Preben

    1997-01-01

    This is the final report submitted to EC in connection with a project on duration of load. The report contains the results of the experimental work on duration of load for beams and notched beams of LVL and of glulam. The report also contains experimental results from duration of load experiments...... including finger jointed boards....

  2. Antigenotoxic potential of Asparagus racemosus root extract against electron beam radiation induced micronuclei formation in Swiss albino mice

    International Nuclear Information System (INIS)

    Bhandary, B. Satheesh Kumar; Sharmila, K.P.; Suchetha Kumari, N.; Bhat, Vadish S.; Shetty, Jayaram; Peter, Alex John; Jose, Jerish M.; Fernandes, Ronald

    2016-01-01

    To evaluate the antigenotoxic potential of Asparagus Racemosus Root ethanolic extract (ARE) against electron beam radiation induced micronuclei formation in Swiss albino mice. Micronucleus assay was performed in the bone marrow of Swiss albino mice according to the method of Hosseinimehr et al., 2003. The experimental animals were orally administered 200 mg/kg body weight of ARE once daily for 15 consecutive days. At the end of experimental period, the animals were euthanized and the bone marrow was collected from the femur. Control (C), Radiation control (RC) and drug control (DC) group was also maintained. The number of radiation induced Micronucleated Polychromatic Erythrocytes (MnPCE) and Micronucleated Normochromatic Erythrocytes were decreased in the ARE treated mice which was statistically significant (p<0.05) compared to radiation control group. Present findings demonstrate the antigenotoxic potential of ARE against electron beam radiation induced micronuclei formation which may be attributed to scavenging of radiation-induced free radicals

  3. Preservation effect of high energy electron beam on kyoho grape

    International Nuclear Information System (INIS)

    Wang Qiufeng; Chen Zhaoliang; Qiao Yongjin; Wang Haihong; Qiao Xuguang

    2010-01-01

    The Kyoho grapes were kept in cold storage of-0.5 degree C ∼ 0.5 degree C, RH 85% ∼ 95% after irradiation of 400, 700, 1000, 1500, 2500 Gy and SO 2 treatment, and the antiseptic effect and storage quality were studied. The result showed that high energy electron beam could control the growth of bacteria, mould, yeast, coliform, alleviate the deterioration of grapes during storage. Irradiation below the dose 1000 Gy can decrease the respiration intensity, prevent the decreasing of titratable acid, ascorbic acid content, and keep higher activity of SOD enzyme. The Vc content was 3.79 mg /100 g after 700 Gy irradiation 90 days, the titratable acid and total soluble sugar content were 0.348%, 11.44%, and the activity of SOD was 14.89 U /g, which was higher than the control significantly (P 2 bleaching spot. Integrate the effects on microorganism control and grape quality, treatment of 700 Gy had the best preservation effect in this study. After preserved for 98 d, the good fruit rate of 700 Gy treatment was 93.33% , significantly higher than other treatments (P < 0.05). (authors)

  4. Assessment of protocols in cone beam CT with symmetric and asymmetric beam using effective dose and P{sub ka}

    Energy Technology Data Exchange (ETDEWEB)

    Batista, W. O.; Linhares de O, M. V. [Instituto Federal da Bahia, Rua Emidio dos Santos s/n, Barbalho, Salvador, 40301015 Bahia (Brazil); Soares, M. R.; Maia, A. F. [Universidade Federal de Sergipe, Departamento de Fisica, Cidade Universitaria Prof. Jose Aloisio de Campos, Marechal Rondon s/n, Jardim Rosa Elze, 49-100000 Sao Cristovao, Sergipe (Brazil); Caldas, L. V. E., E-mail: wilsonottobatista@gmail.com [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    The cone beam CT is an emerging technology in dental radiology with significant differences the point of view of design technology between the various manufacturers on the world market. This study aims to evaluate and compare protocols with similar purposes in a cone beam CT scanner using TLDs and air kerma - area product (P{sub ka}) as kerma index. Measurements were performed on two protocols used to obtain the image the maxilla-mandible in equipment Gendex GXCB 500: Protocol [GX1] extended diameter and asymmetric beam (14 cm x 8.5 cm - maxilla / mandible) and protocol [GX2] symmetrical beam (8.5 cm x 8.5 cm - maxillary / mandible). Was used LiF dosimeters (TLD 100) inserted into a female anthropomorphic phantom manufactured by Radiology Support Devices. For all protocols evaluated the value of P{sub ka} using a meter Diamentor E2 and PTW system Radcal Rapidose. The results obtained for Effective Dose / P{sub ka} these measurements were separated by protocol image. Protocol [GX1]: 44.5 μSv/478 mGy cm{sup 2}; protocol [GX2]: 54.8 μSv/507 mGy cm{sup 2}. These values indicate that the relationship between the diameter of the image acquired in the protocol [GX1] and the diameter of the image in the protocol [GX2] is equal to 1.65, the Effective Dose for the first protocol has lower value at 18%. P{sub ka} values reveal very similar results between the two protocols, although, common sense leads to the interpretation that imaging protocols with field of view (Fov) of large diameters imply high values of effective dose when compared to small diameters. However, in this particular case, this is not true due to the asymmetrical beam technology. Conclude that for the cases where the scanner uses asymmetric beam to obtain images with large diameters that cover the entire face there are advantages from the point of view of reducing the exposure of patients with respect to the use of symmetrical beam and / or to Fov images with a smaller diameter. (Author)

  5. Assessment of protocols in cone beam CT with symmetric and asymmetric beam using effective dose and Pka

    International Nuclear Information System (INIS)

    Batista, W. O.; Linhares de O, M. V.; Soares, M. R.; Maia, A. F.; Caldas, L. V. E.

    2014-08-01

    The cone beam CT is an emerging technology in dental radiology with significant differences the point of view of design technology between the various manufacturers on the world market. This study aims to evaluate and compare protocols with similar purposes in a cone beam CT scanner using TLDs and air kerma - area product (P ka ) as kerma index. Measurements were performed on two protocols used to obtain the image the maxilla-mandible in equipment Gendex GXCB 500: Protocol [GX1] extended diameter and asymmetric beam (14 cm x 8.5 cm - maxilla / mandible) and protocol [GX2] symmetrical beam (8.5 cm x 8.5 cm - maxillary / mandible). Was used LiF dosimeters (TLD 100) inserted into a female anthropomorphic phantom manufactured by Radiology Support Devices. For all protocols evaluated the value of P ka using a meter Diamentor E2 and PTW system Radcal Rapidose. The results obtained for Effective Dose / P ka these measurements were separated by protocol image. Protocol [GX1]: 44.5 μSv/478 mGy cm 2 ; protocol [GX2]: 54.8 μSv/507 mGy cm 2 . These values indicate that the relationship between the diameter of the image acquired in the protocol [GX1] and the diameter of the image in the protocol [GX2] is equal to 1.65, the Effective Dose for the first protocol has lower value at 18%. P ka values reveal very similar results between the two protocols, although, common sense leads to the interpretation that imaging protocols with field of view (Fov) of large diameters imply high values of effective dose when compared to small diameters. However, in this particular case, this is not true due to the asymmetrical beam technology. Conclude that for the cases where the scanner uses asymmetric beam to obtain images with large diameters that cover the entire face there are advantages from the point of view of reducing the exposure of patients with respect to the use of symmetrical beam and / or to Fov images with a smaller diameter. (Author)

  6. Intensity-gradient induced Sisyphus cooling of a single atom in a localized hollow-beam trap

    International Nuclear Information System (INIS)

    Yin, Yaling; Xia, Yong; Ren, Ruimin; Du, Xiangli; Yin, Jianping

    2015-01-01

    In order to realize a convenient and efficient laser cooling of a single atom, we propose a simple and promising scheme to cool a single neutral atom in a blue-detuned localized hollow-beam trap by intensity-gradient induced Sisyphus cooling, and study the dynamic process of the intensity-gradient cooling of a single 87 Rb atom in the localized hollow-beam trap by using Monte-Carlo simulations. Our study shows that a single 87 Rb atom with a temperature of 120 μK from a magneto-optical trap (MOT) can be directly cooled to a final temperature of 4.64 μK in our proposed scheme. We also investigate the dependences of the cooling results on the laser detuning δ of the localized hollow-beam, the power RP 0 of the re-pumping laser beam, the sizes of both the localized hollow-beam and the re-pumping beam, and find that there is a pair of optimal cooling parameters (δ and RP 0 ) for an expected lowest temperature, and the cooling results strongly depend on the size of the re-pumping beam, but weakly depend on the size of the localized hollow-beam. Finally, we further study the cooling potential of our localized hollow-beam trap for the initial temperature of a single atom, and find that a single 87 Rb atom with an initial temperature of higher than 1 mK can also be cooled directly to about 6.6 μK. (paper)

  7. Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run

    Czech Academy of Sciences Publication Activity Database

    Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Gallus, Petr; Gunther, Jaroslav; Jakoubek, Tomáš; Juránek, Vojtěch; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Valenta, J.; Vrba, Václav

    2013-01-01

    Roč. 8, Jul (2013), s. 1-58 ISSN 1748-0221 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : background * induced * semiconductor detector * pixel * muon * spectrometer * jet * single production * ATLAS * calorimeter * new physics * beam Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.526, year: 2013

  8. Study on Nanostructures Induced by High-Current Pulsed Electron Beam

    Directory of Open Access Journals (Sweden)

    Bo Gao

    2012-01-01

    Full Text Available Four techniques using high-current pulsed electron beam (HCPEB were proposed to obtain surface nanostructure of metal and alloys. The first method involves the distribution of several fine Mg nanoparticles on the top surface of treated samples by evaporation of pure Mg with low boiling point. The second technique uses superfast heating, melting, and cooling induced by HCPEB irradiation to refine the primary phase or the second phase in alloys to nanosized uniform distributed phases in the matrix, such as the quasicrystal phase Mg30Zn60Y10 in the quasicrystal alloy Mg67Zn30Y3. The third technique involves the refinement of eutectic silicon phase in hypereutectic Al-15Si alloys to fine particles with the size of several nanometers through solid solution and precipitation refinement. Finally, in the deformation zone induced by HCPEB irradiation, the grain size can be refined to several hundred nanometers, such as the grain size of the hypereutectic Al-15Si alloys in the deformation zone, which can reach ~400 nm after HCPEB treatment for 25 pulses. Therefore, HCPEB technology is an efficient way to obtain surface nanostructure.

  9. Effective dose from cone beam CT examinations in dentistry.

    Science.gov (United States)

    Roberts, J A; Drage, N A; Davies, J; Thomas, D W

    2009-01-01

    Cone beam CT (CBCT) is becoming an increasingly utilized imaging modality for dental examinations in the UK. Previous studies have presented little information on patient dose for the range of fields of view (FOVs) that can be utilized. The purpose of the study was therefore to calculate the effective dose delivered to the patient during a selection of CBCT examinations performed in dentistry. In particular, the i-CAT CBCT scanner was investigated for several imaging protocols commonly used in clinical practice. A Rando phantom containing thermoluminescent dosemeters was scanned. Using both the 1990 and recently approved 2007 International Commission on Radiological Protection recommended tissue weighting factors, effective doses were calculated. The doses (E(1990), E(2007)) were: full FOV head (92.8 microSv, 206.2 microSv); 13 cm scan of the jaws (39.5 microSv, 133.9 microSv); 6 cm high-resolution mandible (47.2 microSv, 188.5 microSv); 6 cm high-resolution maxilla (18.5 microSv, 93.3 microSv); 6 cm standard mandible (23.9 microSv, 96.2 microSv); and 6 cm standard maxilla (9.7 microSv, 58.9 microSv). The doses from CBCT are low compared with conventional CT but significantly higher than conventional dental radiography techniques.

  10. Effect of the loading rate on fibre reinforced concrete beams

    Science.gov (United States)

    Juhász, K. P.; Schaul, P.; Nagy, L.

    2017-09-01

    Fibre reinforced concrete has become a widely used material since the end of the 20th century. The uniformly distributed steel or macro synthetic fibres in the concrete structures can give the concrete a residual flexural strength after the first cracks. The different behaviour of materials subjected to different loading rates is a well-known phenomenon, both with steel, synthetic and concrete materials. Standards usually present a recommendation for the loading speed in for different tests. Concrete elements show higher performance due to the high speed of loading or impact loads, their fracture energy and therefore their overall capacity appears greater than the specimens loaded at standard speeds. Fibre reinforced concrete structures are widely used in tramlines and railways, where the speed of the loading is high and therefore of impact by nature. It is important to know what the effect of this high speed loading is for fibre reinforced concrete structures: do these structures have additional capacity, or has the designer overestimated their performance? This article will present an investigation into the effect of the loading rate on case of using fibres with different materials in concrete beams.

  11. Molecular dynamics studies of the ion beam induced crystallization in silicon

    International Nuclear Information System (INIS)

    Marques, L.A.; Caturla, M.J.; Huang, H.

    1995-01-01

    We have studied the ion bombardment induced amorphous-to-crystal transition in silicon using molecular dynamics techniques. The growth of small crystal seeds embedded in the amorphous phase has been monitored for several temperatures in order to get information on the effect of the thermal temperature increase introduced by the incoming ion. The role of ion-induced defects on the growth has been also studied

  12. Lattices with minimal space charge effects for crystalline beams

    Energy Technology Data Exchange (ETDEWEB)

    Channell, P.J.; Neri, F.R.

    1995-12-31

    There are numerous techniques for cooling beams of charged particles including stochastic cooling, electron beam cooling, ionization (foil) cooling (for lepton beams only), and laser cooling which works only with ions with some electrons still attached. The successful implementation of laser cooling at Aarhus, has led to interest in crystalline beams, and it certainly seems that crystallization of small numbers of stored particles should be possible. There are limits, however, that may restrict the total number of charged particles stored; these include the limit on the space-charge tune shift, {vert_bar}{triangle}{nu}{vert_bar} < 0.25 (though the precise number is subject to debate) and intrabeam scattering. In this paper we will be concerned with the possibility of intense crystalline beams; for simplicity we treat only the nonrelativistic case, though the relativistic case is a simple extension of this work. In the next section we review the limits on the number of particles stored and observe that the beam size scaling with beam temperature is the important dependence that determines the limits on the stored current as a function of beam temperature. In section 3 we use a general formalism to determine the beam size scaling and apply it to various kinds of focusing lattices and determine the relevant limits. In section 4 we use simulations that include lattice elements, a cooling model, and an N-body space-charge model to confirm the predictions of section 3 and to explore the details of various schemes. In the final section we summarize and discuss our results.

  13. Electron temperature effects for an ion beam source

    International Nuclear Information System (INIS)

    Uramoto, Joshin.

    1979-05-01

    A hydrogen high temperature plasma up to 200 eV is produced by acceleration of electrons in a hot hollow cathode discharge and is used as an ion beam source. Then, two characteristics are observed: A rate of the atomic ion (H + ) number increases above 70%. A perveance of the ion beam increases above 30 times compared with that of a cold plasma, while a floating potential of an ion acceleration electrode approaches an ion acceleration potential (- 500 V) according as an increment of the electron temperature. Moreover, a neutralized ion beam can be produced by only the negative floating electrode without an external power supply. (author)

  14. Effect of web openings on the structural behavior of RC beams subjected to pure torsion

    Directory of Open Access Journals (Sweden)

    Abdo Taha

    2017-01-01

    Full Text Available In the construction of modern buildings, the presence of openings became a necessity nowadays in order to accommodate the many pipes and ducts required for the different services. On the other hand, the presence of these openings in RC beams affects their structural behavior. One important behavior that needs further study would be torsion. Currently, there are no guide lines available to analyze or design RC beams with web openings under pure torsion. Thus, the main objective of this research is to investigate the behavior of simply supported RC beams with openings subjected to pure torsion. In the first part of this paper, an experimental study is conducted on seven beams subjected to pure torsion loading in order to investigate the effect of the number of openings, the spacing between stirrups, and beam depth. All beams have a constant clear span length of 1800 mm and a constant beam width of 150 mm. The beams have varying opening number and stirrups arrangement as well as varying beam depth in order to investigate the effect of these parameters on the behavior of the beams. Systematic measurements such as the cracking torque, the ultimate torque, the angle of rotation of the beam at cracking, and the angle of rotation of the beam at the ultimate load are conducted for further understanding of the beam behavior under torsion. In the second part of the paper, the experimental results are compared with the numerical results obtained using the non-linear finite element analysis program, ANSYS. Good agreement between the experimental and numerical results is found.

  15. Stabilizing effect of gas conductivity evolution on the resistive sausage mode of a propagating beam

    International Nuclear Information System (INIS)

    Lampe, M.; Joyce, G.

    1983-01-01

    Previous theoretical work has shown that a highly current-neutralized charged particle beam propagating in a preionized plasma channel of fixed conductivity is subject to a resistive sausage instability. It is shown that the instability is stabilized, for the case of beam propagation into an initially un-ionized gas, when the effect of beam-collisional ionization on the gas conductivity is modeled fully self-consistently

  16. The effect of electron beam radiations on testicular damage in mice, Mus musculus

    International Nuclear Information System (INIS)

    Vikram, S.; Nair, Vijay Mala Grover

    2013-01-01

    Adult male Swiss albino mice, Mus musculus (8-10 weeks old) weighing 28±2.5 gm were exposed to varying doses (2-12 Gy) of electron beam radiations and maintained in animal house at 26-28 C. The animals were sacrificed following 35 and 60 days following exposure to electron beam radiations. The LD-50 value, change in the weight and histological details of the testis, sperm count, sperm shape abnormalities and sperm motility were recorded. The data suggests that electron beam radiations is a potential inducer to cause reproductive system dysfunctions which probably may be responsible leading to infertility. (author)

  17. High resolution laser beam induced current images under trichromatic laser radiation: approximation to the solar irradiation.

    Science.gov (United States)

    Navas, F J; Alcántara, R; Fernández-Lorenzo, C; Martín-Calleja, J

    2010-03-01

    A laser beam induced current (LBIC) map of a photoactive surface is a very useful tool when it is necessary to study the spatial variability of properties such as photoconverter efficiency or factors connected with the recombination of carriers. Obtaining high spatial resolution LBIC maps involves irradiating the photoactive surface with a photonic beam with Gaussian power distribution and with a low dispersion coefficient. Laser emission fulfils these characteristics, but against it is the fact that it is highly monochromatic and therefore has a spectral distribution different to solar emissions. This work presents an instrumental system and procedure to obtain high spatial resolution LBIC maps in conditions approximating solar irradiation. The methodology developed consists of a trichromatic irradiation system based on three sources of laser excitation with emission in the red, green, and blue zones of the electromagnetic spectrum. The relative irradiation powers are determined by either solar spectrum distribution or Planck's emission formula which provides information approximate to the behavior of the system if it were under solar irradiation. In turn, an algorithm and a procedure have been developed to be able to form images based on the scans performed by the three lasers, providing information about the photoconverter efficiency of photovoltaic devices under the irradiation conditions used. This system has been checked with three photosensitive devices based on three different technologies: a commercial silicon photodiode, a commercial photoresistor, and a dye-sensitized solar cell. These devices make it possible to check how the superficial quantum efficiency has areas dependent upon the excitation wavelength while it has been possible to measure global incident photon-to-current efficiency values approximating those that would be obtained under irradiation conditions with sunlight.

  18. Images of paraffin monolayer crystals with perfect contrast: minimization of beam-induced specimen motion

    Science.gov (United States)

    Glaeser, R.M.; McMullan, G.; Faruqi, A.R.; Henderson, R.

    2013-01-01

    Quantitative analysis of electron microscope images of organic and biological two-dimensional crystals has previously shown that the absolute contrast reached only a fraction of that expected theoretically from the electron diffraction amplitudes. The accepted explanation for this is that irradiation of the specimen causes beam-induced charging or movement, which in turn causes blurring of the image due to image or specimen movement. In this paper, we used three different approaches to try to overcome this image-blurring problem for monolayer crystals of paraffin. Our first approach was to use an extreme form of spotscan imaging, in which a single image was assembled on film by the successive illumination of up to 50,000 spots each of diameter around 7nm. The second approach was to use the Medipix II detector with its zero-noise readout to assemble a time-sliced series of images of the same area in which each frame from a movie with up to 400 frames had an exposure of only 500 electrons. In the third approach, we simply used a much thicker carbon support film to increase the physical strength and conductivity of the support. Surprisingly, the first two methods involving dose fractionation respectively in space or time produced only partial improvements in contrast whereas the third approach produced many virtually perfect images, in which the absolute contrast predicted from the electron diffraction amplitudes was observed in the images. We conclude that it is possible to obtain consistently almost perfect images of beam-sensitive specimens if they are attached to an appropriately strong and conductive support, but great care is needed in practice and the problem of how best to image ice-embedded biological structures in the absence of a strong, conductive support film requires more work. PMID:21185452

  19. Electron-beam induced RAFT-graft polymerization of poly(acrylic acid) onto PVDF

    International Nuclear Information System (INIS)

    Grasselli, M.; Betz, N.

    2005-01-01

    This paper explores for the first time the post-radiation-induced-graft polymerization on solid substrate using reversible addition-fragmentation transfer (RAFT) mechanism. Radiation-induced graft polymerization onto polymers is a potentially interesting technique to create easily new materials from highly resistant polymers, e.g. surface graft polymerization of acrylic acid (AA) onto poly(vinylidene difluoride) (PVDF) improves its surface properties without losing its excellent mechanical properties. As a consequence of the radical nature of the polymerization processes it is difficult to control molecular weight of grafted chains, and therefore design and standardize the properties of the final product. RAFT polymerization is a suitable method to obtain monodisperse polymers. The ability of the RAFT agents to control the polymer chain length could be an interesting approach to improve the grafted polymers obtained by post-radiation-induced-graft polymerization technique. In this way, graft polymerization of AA onto electron-beam irradiated α-PVDF was performed using trithiocarbonic acid bis(1-phenylethyl) ester as a RAFT agent to control the radical polymerization. We studied several grafting parameters such as solvent, monomer concentration and grafting time in order to achieve a poly(acrylic acid) (PAA) layer onto PVDF surface. Acetic acid was found to be the best solvent for many reasons, as to drive graft polymerization mainly to the polymer surface, complete solubility and stability of all reactants. Hydrolysis of PAA chains was also studied in order to remove the trithiocarbonate functionality from the grafted polymer. A mild chemical condition was achieved in order to have thiol groups that were detected onto the modified PVDF by specific enzymatic reaction

  20. Beam steering effects in turbulent high pressure flames

    Energy Technology Data Exchange (ETDEWEB)

    Hemmerling, B.; Kaeppeli, B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The propagation of a laser beam through a flame is influenced by variations of the optical density. Especially in turbulent high pressure flames this may seriously limit the use of laser diagnostic methods. (author) 1 fig., 2 refs.

  1. THE EFFECT OF FLY ASH ON FLEXURAL CAPACITY CONCRETE BEAMS

    Directory of Open Access Journals (Sweden)

    Amir Mohammad Amiri

    2016-06-01

    Full Text Available This paper presents the flexural response of Reinforced Geopolymer Concrete (RGPC beam. A commercial finite element (FE software ABAQUS has been used to perform a structural behavior of RGPC beam. Using parameters such: stress, strain, Young’s modulus, and Poisson’s ratio obtained from experimental results, a beam model has been simulated in ABAQUS. The results from experimental test and ABAQUS simulation were compared. Due to friction forces at the supports and loading rollers; slip occurring, the actual deflection of RGPC beam from experimental test results were slightly different from the results of ABAQUS. And there is good agreement between the crack patterns of fly-ash based geopolymer concrete generated by FE analysis using ABAQUS, and those in experimental data.

  2. Beam generations of three kinds of charged particles

    International Nuclear Information System (INIS)

    Niu, K.; Mulser, P.; Drska, L.

    1991-01-01

    Analyses are given for beam generations of three kinds of charged particles: electrons, light ions, and heavy ions. The electron beam oscillates in a dense plasma irradiated by a strong laser light. When the frequency of laser light is high and its intensity ia large, the acceleration of oscillating electrons becomes large and the electrons radiate electromagnetic waves. As the reaction, the electrons feel a damping force, whose effect on oscillating electron motion is investigated first. Second, the electron beam induces the strong electromagnetic field by its self-induced electric current density when the electron number density is high. The induced electric field reduces the oscillation motion and deforms the beam. In the case of a light ion beam, the electrostatic field, induced by the beam charge, as well as the electromagnetic field, induced by the beam current, affects the beam motion. The total energy of the magnetic field surrounding the beam is rather small in comparison with its kinetic energy. In the case of heavy ion beams the beam charge at the leading edge is much smaller in comparison with the case of light ion beams when the heavy ion beam propagates in the background plasma. Thus, the induced electrostatic and electromagnetic fields do not much affect the beam propagation. (author)

  3. Effect of electron beam irradiation on fisheries water

    International Nuclear Information System (INIS)

    Sarala Selambakkannu; Khomsaton Abu Bakar; Jamaliah Shariff; Suhairi Alimon

    2012-01-01

    This paper studies about water obtained from fish pond of fisheries research centre. Usual water quality parameters such as pH, COD, Turbidity and Ammonia content were analyzed before and after irradiation. Electron beam irradiation was used to irradiate the water with the dose 100 kGy, 200 kGy and 300 kGy. Only high dose was applied on this water as only a limited amount of samples was supplied. All the parameters indicated a slight increase after irradiation except for the ammonia content, which showed a gradual decrease as irradiation dose increases. Sample condition was changed before irradiation in order to obtain more effective results in the following batch. The water sample from fisheries was diluted with distilled water to the ratio of 1:1.This was followed with irradiation at 100 kGy, 200 kGy and 300 kGy. The results still showed an increase in all parameters after irradiation except for ammonia content. For the following irradiation batch, the pH of the sample was adjusted to pH 4 and pH 8 before irradiation. For this sample the irradiation dose selected was only 100 kGy. A higher value of ammonia was observed for the sample with pH 4 after irradiation. Other parameters were almost the same as the first two batches. (author)

  4. Transgenerational effects of proton beam irradiation on Caenorhabditis elegans germline apoptosis.

    Science.gov (United States)

    Min, Hyemin; Sung, Minhee; Son, Miseol; Kawasaki, Ichiro; Shim, Yhong-Hee

    2017-08-26

    When treating cancer using radiation therapy, it is critical to increase patient survival rates and to reduce side effects. In this respect, proton beam radiation treatment performs better than other radiation treatments because of its high target specificity. However, complications still remain after proton beam radiation treatment. Among them, the risk to progeny after irradiation of their parents is a major concern. In this study, we analyzed the transgenerational effects of proton beam irradiation using the model organism Caenorhabditis. elegans. We found that germline apoptosis increased after proton beam irradiation and its effects were sustained transgenerationally. Moreover, we identified that a germline-specific histone methyltransferase component, SET-2, has a critical role in transmitting the transgenerational effect on germline apoptosis to the next generation after proton beam irradiation. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Beam-dynamic effects at the CMS BRIL van der Meer scans

    CERN Document Server

    Babaev, Anton

    2017-01-01

    The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is responsible for the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS experiment. The project is engaged in operating and developing new detectors (luminometers), adequate for the experimental conditions associated with high values of instantaneous luminosity delivered by the CERN LHC. BRIL operates several detectors based on different physical principles and technologies. Precise and accurate measurements of the delivered luminosity is of paramount importance for the CMS physics program. The absolute calibration of luminosity is achieved by the van der Meer method, which is carried out under specially tailored conditions. This paper presents models used to simulate of beam-dynamic effects arising due to the electromagnetic interaction of colliding bunches. These effects include beam-beam deflection and dynamic-beta effect. Both effects are important to luminosity measurements and influence calibrat...

  6. 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

  7. UV laser induced proton-transfer of protein molecule in the gas phase produced by droplet-beam laser ablation

    Science.gov (United States)

    Kohno, Jun-ya; Kondow, Tamotsu

    2008-09-01

    Droplet-beam laser-ablation mass-spectrometry was applied for a study of the UV-laser induced proton-transfer reaction of protonated lysozyme hydrated clusters in the gas phase. Protonated lysozyme hydrated clusters were produced by irradiation of an IR laser onto a droplet-beam of an aqueous solution of lysozyme and were subsequently irradiated by a UV laser. It is found that H + and H 3O + are produced through photodissociation of protonated lysozyme hydrated clusters. The mechanism of the proton-transfer reaction is discussed.

  8. Radiation reaction induced spiral attractors in ultra-intense colliding laser beams

    Directory of Open Access Journals (Sweden)

    Zheng Gong

    2016-11-01

    Full Text Available The radiation reaction effects on electron dynamics in counter-propagating circularly polarized laser beams are investigated through the linearization theorem and the results are in great agreement with numeric solutions. For the first time, the properties of fixed points in electron phase-space were analyzed with linear stability theory, showing that center nodes will become attractors if the classical radiation reaction is considered. Electron dynamics are significantly affected by the properties of the fixed points and the electron phase-space densities are found to be increasing exponentially near the attractors. The density growth rates are derived theoretically and further verified by particle-in-cell simulations, which can be detected in experiments to explore the effects of radiation reaction qualitatively. The attractor can also facilitate realizing a series of nanometer-scaled flying electron slices via adjusting the colliding laser frequencies.

  9. MOLECULAR BEAM STUDIES OF IR LASER INDUCED MULTIPHOTON DISSOCIATION AND VIBRATIONAL PREDISSOCIATION

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yuan T.; Shen, Y. Ron

    1980-06-01

    The advancement of crossed molecular beam methods, modern spectroscopy and laser technology allows us to observe chemical reactions on atomic and molecular levels in great detail. After a brief history of crossed molecular beams studies, the author describes and discusses the universal molecular beam apparatus and gives examples of crossed molecular beam studies. The crossed beam technique is compared to other techniques used to provide microscopic information on reaction dynamics. Application of crossed laser and molecular beam studies to the problem of IR multiphoton dissociation of polyatomic molecules is discussed. Study of vibrational predissociation of hydrogen-bonded and van der Waals molecular clusters are discussed. Future cases that the author considers worth pursuing that could benefit from the collisionless environment of molecular beams are enumerated.

  10. Effects of tissue inhomogeneities on dose patterns in cylinders irradiated by negative pion beams

    International Nuclear Information System (INIS)

    Hamm, R.N.; Wright, H.A.; Turner, J.E.

    1975-10-01

    Effects of the presence of inhomogeneities in tissue irradiated by negative pion beams are investigated. Soft-tissue targets are considered with embedded regions of bone and cavities of air. The absorbed dose is calculated as a function of position in the targets for parallel and converging beams and for two parallel beams that enter the target from opposite sides. Isodose contours are calculated and displayed in each case. While these studies show expected trends, they indicate that specific calculations are needed for other beam parameters and target geometries. The contributions of neutrons to the dose contours can be seen from several calculations made both with and without neutrons

  11. Beam diagnostics

    International Nuclear Information System (INIS)

    Bogaty, J.; Clifft, B.E.; Zinkann, G.P.; Pardo, R.C.

    1995-01-01

    The ECR-PII injector beam line is operated at a fixed ion velocity. The platform high voltage is chosen so that all ions have a velocity of 0.0085c at the PII entrance. If a previous tune configuration for the linac is to be used, the beam arrival time must be matched to the previous tune as well. A nondestructive beam-phase pickup detector was developed and installed at the entrance to the PII linac. This device provides continuous phase and beam current information and allows quick optimization of the beam injected into PII. Bunches traverse a short tubular electrode thereby inducing displacement currents. These currents are brought outside the vacuum interface where a lumped inductance resonates electrode capacitance at one of the bunching harmonic frequencies. This configuration yields a basic sensitivity of a few hundred millivolts signal per microampere of beam current. Beam-induced radiofrequency signals are summed against an offset frequency generated by our master oscillator. The resulting kilohertz difference frequency conveys beam intensity and bunch phase information which is sent to separate processing channels. One channel utilizes a phase locked loop which stabilizes phase readings if beam is unstable. The other channel uses a linear full wave active rectifier circuit which converts kilohertz sine wave signal amplitude to a D.C. voltage representing beam current. A prototype set of electronics is now in use with the detector and we began to use the system in operation to set the arrival beam phase. A permanent version of the electronics system for the phase detector is now under construction. Additional nondestructive beam intensity and phase monitors at the open-quotes Boosterclose quotes and open-quotes ATLASclose quotes linac sections are planned as well as on some of the high-energy beam lines. Such a monitor will be particularly useful for FMA experiments where the primary beam hits one of the electric deflector plates

  12. Beam emittance and the effects of the rf, space charge and wake fields: Application to the ATF photoelectron beam

    International Nuclear Information System (INIS)

    Parsa, Z.

    1991-01-01

    Laser driven photoelectron guns are of interest for use in new methods of accelerations, future development of Linear Colliders and new experiments such as Free Electron laser (IFEL). Such guns are potential source of low emittance-high current and short bunch length electron beams, where the emitted electrons are accelerated quickly to a relativistic energy by a strong rf, electric field in the cavity. We present a brief overview of the beam dynamic studies, e.g. emittance for the Brookhaven National Laboratory (BNL) ATF high brightness photocathode radio frequency gun (now in operation), and show the effects of the rf, Space Charge, and Wake fields on the photoelectrons. 4 refs., 7 figs

  13. Rejoining kinetics of G1-PCC breaks induced by different heavy-ion beams with a similar LET value.

    Science.gov (United States)

    Tsuruoka, Chizuru; Furusawa, Yoshiya; Anzai, Kazunori; Okayasu, Ryuichi; Suzuki, Masao

    2010-08-14

    In previous studies we have shown that the linear energy transfer (LET)-relative biological effectiveness (RBE) curves were affected by LET and ion species [1,2]. In this paper we have examined the difference in the repair kinetics of G1-prematurely condensed chromosome breaks in normal human fibroblasts following irradiation with different heavy-ion beams of similar LET values. Normal human fibroblasts were irradiated with about 110 keV/microm of carbon (135 MeV/n), neon (400 MeV/n) and silicon ions (490 MeV/n), and the doses of carbon (3.25 Gy), neon (2.94+/-0.01 Gy) and silicon (2.31 Gy) were chosen to produce approximately the same number of initially measured G1-premature chromosome condensation (PCC) breaks (about 37 excess fragments per cell). The number of G1-PCC breaks was counted as excess fragments of prematurely condensed chromosomes using the PCC technique in the G1/G0 phase. The fractions of residual G1-PCC breaks after 24 h post-irradiation and half time, which is the time point where 50% of initially measured G1-PCC breaks are rejoined (t1/2), of the slow components of rejoining in carbon- and neon-ion irradiated cells were different from those of silicon-ion irradiated cells. However, no difference was observed in the half time of the fast components of rejoining in each ion beam. The results suggest that the difference in the fractions of residual G1-PCC breaks after 24 h post-irradiation reflect the result of the slow repair process for induced G1-PCC breaks, and that the repair process is dependent on the ion species, not the LET values. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  14. Microstructure evolution of nanostructured and submicrometric porous refractory ceramics induced by a continuous high-energy proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Sandrina [CERN, 1211 Geneva 23 (Switzerland); Bruetsch, Roland [Paul Scherrer Institut, 5232 Villigen (Switzerland); Catherall, Richard [CERN, 1211 Geneva 23 (Switzerland); Groeschel, Friedrich; Guenther-Leopold, Ines [Paul Scherrer Institut, 5232 Villigen (Switzerland); Lettry, Jacques [CERN, 1211 Geneva 23 (Switzerland); Manfrin, Enzo [Paul Scherrer Institut, 5232 Villigen (Switzerland); Marzari, Stefano; Noah, Etam; Sgobba, Stefano [CERN, 1211 Geneva 23 (Switzerland); Stora, Thierry, E-mail: thierry.stora@cern.ch [CERN, 1211 Geneva 23 (Switzerland); Zanini, Luca [Paul Scherrer Institut, 5232 Villigen (Switzerland)

    2011-09-01

    The production of radioactive ion beams by the isotope mass separation online (ISOL) method requires a fast diffusion and effusion of nuclear products from thick refractory target materials under high-energy particle beam irradiation. A new generation of ISOL nanostructured and submicrometric porous materials have been developed, exhibiting enhanced release of exotic isotopes, compared to previously used conventional micrometric materials. A programme was developed at PSI within the framework sof the Design Study of EURISOL, the next generation European ISOL-type facility to study aging under irradiation on porous ceramic pellets and dense thin metal foils at high temperatures. Ceramic oxides and carbide samples underwent proton damage with fluence up to 3.0 x 10{sup 20} and 1.3 x 10{sup 21} cm{sup -2} respectively. The post-irradiation examination on Al{sub 2}O{sub 3}, Y{sub 2}O{sub 3} and SiC - C nanotube composite matrices show a proton-induced densification region in which a moderate grain growth occurred. The microstructural evolution effects were associated to the combination of radiation-enhanced diffusion and thermal diffusion. The irradiated Al{sub 2}O{sub 3} shows higher sintering rates than in similar non-irradiation isothermal conditions, in particular at the lowest irradiation temperature, subjected to a proton fluence inferior to 1.1 x 10{sup 15} cm{sup -2}. The apparent activation energy for its sintering controlling mechanism was found to be between 44 and 88 kJ mol{sup -1}. However, despite the enhanced sintering, shrinkage and increased grain growth, the selected nanostructured and submicrometric TARPIPE materials did not display an average grain diameter above 2 {mu}m, which confirms that these materials are suited as production targets for present and next generation ISOL facilities.

  15. The Effects of Breathing Behaviour on Crack Growth of a Vibrating Beam

    Directory of Open Access Journals (Sweden)

    Wenguang Liu

    2018-01-01

    Full Text Available The effects of breathing behaviour on the dynamic response and crack growth are studied through a cracked cantilever beam. The main goal is to reveal the coupling mechanism of dynamic response and crack growth by employing a plain single-degree-of-freedom (SDOF lumped system with the breathing crack stiffness and friction damping. The friction damping loss factor is derived by using Coulomb friction model and energy principle. Natural frequency, dynamic stress, dynamic stress intensity factor (DSIF, and crack growth are analyzed by case studies in the end. Results indicate that not only does the stiffness oscillates during crack growth corresponding to the physically open and closed states of the crack, but also stiffness and friction damping oscillate nonlinearly with crack growth. This behaviour induces not only nonlinear dynamic response but also nonlinear crack growth. It provides an approximate description of the nonlinearities introduced by the presence of a breathing crack. Therefore, it can be employed to improve the prediction precision of the crack identification and crack growth life of a cracked cantilever beam.

  16. Interaction of heavy ion beams with a hydrogen plasma: plasma lens effect and stopping power enhancement

    International Nuclear Information System (INIS)

    Gardes, D.; Bimbot, R.; Della-Negra, S.; Dumail, M.; Kubica, B.; Richard, A.; Rivet, M.F.; Servajean, A.; Deutsch, C.; Maynard, G.

    1988-01-01

    By coupling a hydrogen plasma to a Tandem accelerator, transmission and energy losses of 2 MeV/u carbon and sulfur beams passing through a plasma target have been investigated. Fluctuations in beam transmission have been observed and attributed to a plasma lens effect. Moreover, energy loss measurements indicate an enhanced stopping power of the plasma relative to its cold matter equivalent

  17. Spinning Earth and its Coriolis effect on the circuital light beams ...

    Indian Academy of Sciences (India)

    2016-10-06

    Oct 6, 2016 ... on the north pole of Earth where there is no Coriolis effect on light beams propagating vertically. Now let a pencil laser beam at right angle to the mir- ror plane be passed through the minute central hole of the photographic plate to touch the point O1 of the topside mirror and be reflected from that point. The.

  18. Electron-beam curing of epoxy resins: effect of alcohols on cationic ...

    Indian Academy of Sciences (India)

    Unknown

    hydroxyl group reactivity. Current work is directed to- wards the investigation of network formation by e-beam curing of diepoxy based systems (e.g. diglycidyl ether of bisphenol A) and the effect of presence of different OH containing species on the structural as well as mechanical properties of the e-beam cured materials.

  19. Experimental investigation of the ripple induced losses of perpendicularly injected beam ions in the low aspect ratio helical system CHS

    International Nuclear Information System (INIS)

    Isobe, M.; Sasao, M.; Okamura, S.; Murakami, S.; Minami, T.; Kado, S.; Ida, K.; Osakabe, M.; Yoshimura, Y.; Tanaka, K.; Takahashi, C.; Nishimura, S.; Matsuoka, K.; Kondo, T.; Shimizu, A.; Yavorskij, V.A.

    2001-01-01

    Confinement of perpendicularly injected beam ions has been investigated experimentally both in the standard configuration and in the drift optimized configuration of the CHS heliotron/torsatron by means of the neutron technique. The experimental results indicate that the confinement of trapped beam ions is poor in both configurations. The observed loss rate of trapped beam ions was very high and this high rate is not explained by losses due to charge exchange or collisional scattering from the timescale perspective. Full gyro-motion following orbit calculations showed that in the peripheral region of CHS plasmas, trapped beam ions are promptly lost because they immediately intersect the vacuum chamber wall due to their large Larmor radii. It also suggested that in the core domain the collisionless transition behaviour is the key to understanding the rapid loss of beam ions. It was shown that the magnetic moment of perpendicularly injected beam ions is not well conserved in CHS. The rapid losses of perpendicularly injected beam ions are probably due to non-adiabatic effects resulting in the transition behaviour of energetic ions. (author)

  20. Experimental investigation of the ripple induced losses of perpendicularly injected beam ions in the low aspect ratio helical system CHS

    Science.gov (United States)

    Isobe, M.; Sasao, M.; Okamura, S.; Kondo, T.; Murakami, S.; Minami, T.; Kado, S.; Ida, K.; Shimizu, A.; Osakabe, M.; Yoshimura, Y.; Tanaka, K.; Takahashi, C.; Nishimura, S.; Matsuoka, K.; CHS Group; Yavorskij, V. A.

    2001-09-01

    Confinement of perpendicularly injected beam ions has been investigated experimentally both in the standard configuration and in the drift optimized configuration of the CHS heliotron/torsatron by means of the neutron technique. The experimental results indicate that the confinement of trapped beam ions is poor in both configurations. The observed loss rate of trapped beam ions was very high and this high rate is not explained by losses due to charge exchange or collisional scattering from the timescale perspective. Full gyro-motion following orbit calculations showed that in the peripheral region of CHS plasmas, trapped beam ions are promptly lost because they immediately intersect the vacuum chamber wall due to their large Larmor radii. It also suggested that in the core domain the collisionless transition behaviour is the key to understanding the rapid loss of beam ions. It was shown that the magnetic moment of perpendicularly injected beam ions is not well conserved in CHS. The rapid losses of perpendicularly injected beam ions are probably due to non-adiabatic effects resulting in the transition behaviour of energetic ions.

  1. Ion beam-induced shaping of Ni nanoparticles embedded in a silica matrix: from spherical to prolate shape

    Directory of Open Access Journals (Sweden)

    Avasthi Devesh

    2011-01-01

    Full Text Available Abstract Present work reports the elongation of spherical Ni nanoparticles (NPs parallel to each other, due to bombardment with 120 MeV Au+9 ions at a fluence of 5 × 1013 ions/cm2. The Ni NPs embedded in silica matrix have been prepared by atom beam sputtering technique and subsequent annealing. The elongation of Ni NPs due to interaction with Au+9 ions as investigated by cross-sectional transmission electron microscopy (TEM shows a strong dependence on initial Ni particle size and is explained on the basis of thermal spike model. Irradiation induces a change from single crystalline nature of spherical particles to polycrystalline nature of elongated particles. Magnetization measurements indicate that changes in coercivity (Hc and remanence ratio (Mr/Ms are stronger in the ion beam direction due to the preferential easy axis of elongated particles in the beam direction.

  2. Electron-beam-induced welding of 3D nano-objects from beneath

    Energy Technology Data Exchange (ETDEWEB)

    Moskalenko, A V [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Burbridge, D J [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Viau, G [ITODYS, UMR CNRS 7086, Universite Paris 7-Denis Diderot, case 7090, 2 place Jussieu, F-75251 Paris Cedex 05 (France); Gordeev, S N [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2007-01-17

    Exposure of a sample to the electron beam in a scanning electron microscope (SEM) results in the growth of a film of amorphous carbon due to decomposition of hydrocarbon molecules, which are always present in small quantities in the SEM chamber. This growth is induced mainly by secondary electrons backscattered by atoms of both the sample and substrate. We show that, because the secondary electrons are spread beyond the exposed area, this deposit can be grown in areas of geometric shadow and therefore can be used for bonding of different complex 3D nano-objects to a substrate. This is demonstrated by welding 100 nm Fe-Co-Ni nanoparticles to the surface of 2D graphite. The tip of an atomic force microscope was used to probe the mechanical properties of the formed nanostructures. We observed that, for layers thicker than 25 nm, the nanoparticle is bonded so strongly that it is easier to break the particle than to separate it from the substrate.

  3. Chemical tuning of PtC nanostructures fabricated via focused electron beam induced deposition

    International Nuclear Information System (INIS)

    Plank, Harald; Gspan, Christian; Kothleitner, Gerald; Hofer, Ferdinand; Haber, Thomas

    2013-01-01

    The fundamental dependence between process parameters during focused electron beam induced deposition and the chemistry of functional PtC nanostructures have been studied via a multi-technique approach using SEM, (S)TEM, EELS, AFM, and EFM. The study reveals that the highest Pt contents can only be achieved by an ideal balance between potentially dissociating electrons and available precursor molecules on the surface. For precursor regimes apart from this situation, an unwanted increase of carbon is observed which originates from completely different mechanisms: (1) an excess of electrons leads to polymerization of precursor fragments whereas (2) a lack of electrons leads to incompletely dissociated precursor molecules incorporated into the nanostructures. While the former represents an unwanted class of carbon, the latter condition maximizes the volume growth rates and allows for post-growth curing strategies which can strongly increase the functionality. Furthermore, the study gives an explanation of why growing deposits can dynamically change their chemistry and provides a straightforward guide towards more controlled fabrication conditions. (paper)

  4. Raman study of localized recrystallization of amorphous silicon induced by laser beam

    KAUST Repository

    Tabet, Nouar A.

    2012-06-01

    The adoption of amorphous silicon based solar cells has been drastically hindered by the low efficiency of these devices, which is mainly due to a low hole mobility. It has been shown that using both crystallized and amorphous silicon layers in solar cells leads to an enhancement of the device performance. In this study the crystallization of a-Si prepared by PECVD under various growth conditions has been investigated. The growth stresses in the films are determined by measuring the curvature change of the silicon substrate before and after film deposition. Localized crystallization is induced by exposing a-Si films to focused 532 nm laser beam of power ranging from 0.08 to 8 mW. The crystallization process is monitored by recording the Raman spectra after various exposures. The results suggest that growth stresses in the films affect the minimum laser power (threshold power). In addition, a detailed analysis of the width and position of the Raman signal indicates that the silicon grains in the crystallized regions are of few nm diameter. © 2012 IEEE.

  5. Experimental setup and first measurement of DNA damage induced along and around an antiproton beam

    International Nuclear Information System (INIS)

    Kavanagh, J.N.; Currell, F.J.; Prise, K.M.; Schettino, G.; Currell, F.J.; Timson, D.J.; Holzscheiter, M.H.; Bassler, N.; Herrmann, R.

    2010-01-01

    Radiotherapy employs ionizing radiation to induce lethal DNA lesions in cancer cells while minimizing damage to healthy tissues. Due to their pattern of energy deposition, better therapeutic outcomes can, in theory, be achieved with ions compared to photons. Antiprotons have been proposed to offer a further enhancement due to their annihilation at the end of the path. The work presented here aimed to establish and validate an experimental procedure for the quantification of plasmid and genomic DNA damage resulting from antiproton exposure. Immunocytochemistry was used to assess DNA damage in directly and indirectly exposed human fibroblasts irradiated in both plateau and Bragg peak regions of a 126 MeV antiproton beam at CERN. Cells were stained post irradiation with an anti-γ-H2AX antibody. Quantification of the γ-H2AX foci-dose relationship is consistent with a linear increase in the Bragg peak region. A qualitative analysis of the foci detected in the Bragg peak and plateau region indicates significant differences highlighting the different severity of DNA lesions produced along the particle path. Irradiation of desalted plasmid DNA with 5 Gy antiprotons at the Bragg peak resulted in a significant portion of linear plasmid in the resultant solution. (authors)

  6. Suspended tungsten-based nanowires with enhanced mechanical properties grown by focused ion beam induced deposition

    Science.gov (United States)

    Córdoba, Rosa; Lorenzoni, Matteo; Pablo-Navarro, Javier; Magén, César; Pérez-Murano, Francesc; María De Teresa, José

    2017-11-01

    The implementation of three-dimensional (3D) nano-objects as building blocks for the next generation of electro-mechanical, memory and sensing nano-devices is at the forefront of technology. The direct writing of functional 3D nanostructures is made feasible by using a method based on focused ion beam induced deposition (FIBID). We use this technique to grow horizontally suspended tungsten nanowires and then study their nano-mechanical properties by three-point bending method with atomic force microscopy. These measurements reveal that these nanowires exhibit a yield strength up to 12 times higher than that of the bulk tungsten, and near the theoretical value of 0.1 times the Young’s modulus (E). We find a size dependence of E that is adequately described by a core-shell model, which has been confirmed by transmission electron microscopy and compositional analysis at the nanoscale. Additionally, we show that experimental resonance frequencies of suspended nanowires (in the MHz range) are in good agreement with theoretical values. These extraordinary mechanical properties are key to designing electro-mechanically robust nanodevices based on FIBID tungsten nanowires.

  7. Controllable parametric excitation effect on linear and nonlinear vibrational resonances in the dynamics of a buckled beam

    Science.gov (United States)

    Djomo Mbong, T. L. M.; Siewe Siewe, M.; Tchawoua, C.

    2018-01-01

    In this study, the effect of a controllable parametric excitation on both linear and nonlinear vibrational resonances on the dynamic of a buckled beam excited by a combination of uncontrollable low- and high-frequency periodic forces are investigated. First of all, the beam dynamic is assumed to be constrained by two periodic and independent ambient solicitations, such as wind and earthquake. An axial load of the beam represented by a periodic and parametric excitation is used to control the vibrational resonance phenomenon, induced by the presence of the two external excitations. Approximate analytical expressions for the linear response and the high-frequency force amplitude at which linear vibrational resonance occurs are obtained. An analytical expression of the amplitude of the nonlinear response at the superharmonic equal to the double of the low-frequency, is obtained. For all these expressions, we show the effect of the parametric excitation. We compare all the obtained results with the ones of the case where, the parametric force is absent. It is shown that, the presence of the parametric excitation permit the suppression of both linear and nonlinear vibrational resonances. Moreover, the vibration amplitudes of the buckled beam are significantly reduced, around certain threshold values for the amplitude and the frequency of the parametric excitation.

  8. Distribution of products in polymer materials induced by ion-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Masaki; Kudoh, Hisaaki; Sasuga, Tsuneo; Seguchi, Tadao [Japan Atomic Energy Research Inst., Tokyo (Japan); Hama, Yoshimasa; Hamanaka, Ken-ichi; Matsumoto, Hideya

    1997-03-01

    The depth profile of double bond formed in low density polyethylene (LDPE) sheet by ion beams irradiation was observed by a micro FT-IR spectrometer in order to investigate the linear energy transfer (LET) dependency on radiation effects to polymer materials. The distribution of double bond formation in LDPE by irradiation of light ions as H+ was found to be same with the dose distribution calculated from TRIM code, and the yield was also same with that by gamma-rays irradiation, which means that the LET dependency is very small. However, the distribution of double bond to depth was much different from the calculated depth-dose in heavy ions irradiation as Ar and Kr. Then, the dose evaluation was difficult from the TRIM code calculation for heavy ions. (author)

  9. Differential gene expression in primary fibroblasts induced by proton and cobalt-60 beam irradiation

    DEFF Research Database (Denmark)

    Nielsen, Steffen; Bassler, Niels; Grzanka, Leszek

    2017-01-01

    profile: entrance, mid-SOBP and at the SOBP distal edge. Dose was delivered in three fractions × 3.5 Gy(RBE) (RBE 1.1). Cobalt-60 (Co-60) irradiation was used as reference. Real-time qPCR was performed to determine gene expression levels for 17 genes associated with inflammation response, fibrosis...... and angiogenesis. RESULTS: Differences in median gene expression levels were observed for multiple genes such as IL6, IL8 and CXCL12. Median IL6 expression was 30%, 24% and 47% lower in entrance, mid-SOBP and SOBP distal edge groups than in Co-60 irradiated cells. No genes were found to be oppositely regulated...... fibroblast cultures. Inflammatory factors were generally less extensively upregulated by proton irradiation compared with Co-60 photon irradiation. These effects may possibly influence the development of normal tissue damage in patients treated with proton beam therapy....

  10. Analysis of beam plasma instability effects on incoherent scatter spectra

    Directory of Open Access Journals (Sweden)

    M. A. Diaz

    2010-12-01

    Full Text Available Naturally Enhanced Ion Acoustic Lines (NEIALs detected with Incoherent Scatter Radars (ISRs can be produced by a Langmuir decay mechanism, triggered by a bump on tail instability. A recent model of the beam-plasma instability suggests that weak-warm beams, such those associated with NEIAL events, might produce Langmuir harmonics which could be detected by a properly configured ISR. The analysis performed in this work shows that such a beam-driven wave may be simultaneously detected with NEIALs within the baseband signal of a single ISR. The analysis shows that simultaneous detection of NEIALs and the first Langmuir harmonic is more likely than simultaneous detection of NEIALs and enhanced plasma line. This detection not only would help to discriminate between current NEIAL models, but could also aid in the parameter estimation of soft precipitating electrons.

  11. System effects influencing the bending strength of timber beams

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Källsner, B.

    1998-01-01

    measurements of the strengths of a large number of shorttest pieces cut from the beams such that judgementally each test piece contains only a single defect cluster. The testpiece is spliced to stronger wood beam shafts in both ends. Due to the occurrence of a substantial number of splicefailures in the total...... test series of 197 tests a special maximum likelihood estimation procedure is applied to estimate theparameters. Assuming that the estimated parameters are applicable in the series system model for the full uncutbeams a theoretical bending strength distribution function is obtained in dependence......A stochastic model of hierarchical series system type for the bending strength of spruce beams isdefined from the anticipation that the bending failure takes place at a cross-section with a defect cluster formed by knots or grain irregularities. The parameters of the model are estimated from...

  12. Radiation-induced cardiovascular effects

    Science.gov (United States)

    Tapio, Soile

    Recent epidemiological studies indicate that exposure to ionising radiation enhances the risk of cardiovascular mortality and morbidity in a moderate but significant manner. Our goal is to identify molecular mechanisms involved in the pathogenesis of radiation-induced cardiovascular disease using cellular and mouse models. Two radiation targets are studied in detail: the vascular endothelium that plays a pivotal role in the regulation of cardiac function, and the myocardium, in particular damage to the cardiac mitochondria. Ionising radiation causes immediate and persistent alterations in several biological pathways in the endothelium in a dose- and dose-rate dependent manner. High acute and cumulative doses result in rapid, non-transient remodelling of the endothelial cytoskeleton, as well as increased lipid peroxidation and protein oxidation of the heart tissue, independent of whether exposure is local or total body. Proteomic and functional changes are observed in lipid metabolism, glycolysis, mitochondrial function (respiration, ROS production etc.), oxidative stress, cellular adhesion, and cellular structure. The transcriptional regulators Akt and PPAR alpha seem to play a central role in the radiation-response of the endothelium and myocardium, respectively. We have recently started co-operation with GSI in Darmstadt to study the effect of heavy ions on the endothelium. Our research will facilitate the identification of biomarkers associated with adverse cardiac effects of ionising radiation and may lead to the development of countermeasures against radiation-induced cardiac damage.

  13. Electron beam irradiation effects on carbon fiber reinforced PEEK composite

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo; Hagiwara, Miyuki; Odajima, Tosikazu; Sakai, Hideo; Nakakura, Toshiyuki; Masutani, Masahiro.

    1987-03-01

    Carbon fiber(CF) reinforced composites, using polyarylether-sulfone (PES) or polyarylether-ether-ketone (PEEK) as matrix material, were prepared and their electron beam irradiation effects were studied on the basis of changes in mechanical and dynamic viscoelastic properties and observation of fracture surfaces. The flexural strength of PES-CF composite decreased to 70 % of the initial strength after the irradiation of 3 MGy and 40 % after 15 MGy. The change in the profile of stress-strain (S-S) curves and fractographic observation by electron microscopy indicated that this composite irradiated with over 3 MGy was fractured by delamination caused by to the degradation of matrix polymer. The mechanical properties of PEEK-CF composite were scarcely decreased even after irradiated up to 180 MGy and this composite showed very high radiation resistance. The change in the profile of S-S curves and fractographic observation showed that this composite fractured due to destruction of fiber in the dose range less than 180 MGy, indicating that PEEK was excellent matrix material used in high radiation field. PEEK-PES-CF composite which was composed of the carbon fibers coated with PES solution showed less radiation resistance compared with PEEK-CF composite; the flexural strength decreased to 85 % of the initial value after the irradiation with 90 MGy. It was revealed from the changes in the profile of S-S curve that the specimen irradiated over 120 MGy was fractured due to not only fiber destruction but delamination. Deterioration mechanism of PEEK-PES-CF composite was studied by dynamic viscoelastic measurements in connection with the damage on matrix-fiber interface. It was suggested that the deterioration in mechanical properties of this composite was caused by the degradation of PES that coated on the surface of the carbon fibers. (author)

  14. Recent advances in biological effect and molecular mechanism of arabidopsis thaliana irradiated by ion beams

    International Nuclear Information System (INIS)

    Wu Dali; Hou Suiwen; Li Wenjian

    2008-01-01

    Newly research progresses were summarized in effect of ion beams on seed surface, biological effect, growth, development, gravitropism and so on. Furthermore, mutation molecular mechanism of Arabidopsis thaliana was discussed, for example, alteration of DNA bases, DNA damage, chromosomal recombination, characteristics of mutant transmissibility, etc. Meanwhile, the achievements of transfer- ring extraneous gene to Arabidopsis thaliana by ion beams were reviewed in the paper. At last, the future prospective are also discussed here in mutation molecular mechanism and the potential application of biological effect of heavy ion beams. (authors)

  15. Mitigating effect on turbulent scintillation using non-coherent multi-beam overlapped illumination

    Science.gov (United States)

    Zhou, Lu; Tian, Yuzhen; Wang, Rui; Wang, Tingfeng; Sun, Tao; Wang, Canjin; Yang, Xiaotian

    2017-12-01

    In order to find an effective method to mitigate the turbulent scintillation for applications involved laser propagation through atmosphere, we demonstrated one model using non-coherent multi-beam overlapped illumination. Based on lognormal distribution and the statistical moments of overlapped field, the reduction effect on turbulent scintillation of this method was discussed and tested against numerical wave optics simulation and laboratory experiments with phase plates. Our analysis showed that the best mitigating effect, the scintillation index of overlapped field reduced to 1/N of that when using single beam illuminating, could be obtained using this method when the intensity of N emitting beams equaled to each other.

  16. Effect of pulsed hollow electron-lens operation on the proton beam core in LHC

    Energy Technology Data Exchange (ETDEWEB)

    Fitterer, Miriam [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Valishev, Alexander [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-11-08

    Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the HL-LHC. In order to further increase the diffusion rates for a fast halo removal as e.g. desired before the squeeze, the electron lens (e-lens) can be operated in pulsed mode. In case of profile imperfections in the electron beam the pulsing of the e-lens induces noise on the proton beam which can, depending on the frequency content and strength, lead to emittance growth. In order to study the sensitivity to the pulsing pattern and the amplitude, a beam study (machine development MD) at the LHC has been proposed for August 2016 and we present in this note the preparatory simulations and estimates.

  17. The effects of electron beam irradiation on sterilization and preservation of chilled pork

    International Nuclear Information System (INIS)

    Bai Yanhong; Mao Duobin; Zhao Dianbo; Zhang Xiaoyan; Li Quanshun; Yang Gongming

    2009-01-01

    S The effects of electron beam irradiation on the sterilization and preservation of chilled pork were studied. The aim of this investigation was to provide academic and technical basis for application of electron beam irradiation on meat industry. The response surface analysis was used with electron beam energy(X 1 ) and dose(X 2 ) as factors and colony form unit(Y) as responses. The results have been shown that the model of sterilization of chilled pork by electron beam irradiation can be expressed Y=3.78-0.24X 1 -0.13X 2 -0.16X 1 X 2 -0.18X 1 2 +0.15X 1 2 (R 2 =0.9755). It has been found there is a interaction between electron beam energy and absorbed doses, and the significance sequence of factors is absorbed dose>interaction> electron beam energy. When absorbed doses are in range from 3.23 kGy to 4.0 kGy and electron beam energy is in range from 2.3 MeV to 3.8 MeV, the colony form unit would drop 2 logarithm units. The shelf life of samples treated with electron beam irradiation is longer by about 12 d than that of control samples when the samples are stored at 4 degree C. When the samples are stored at 7∼10 degree C, shelf life of samples treated with electron beam irradiation is longer by about 9 d than that of control samples. The results showed that electron beam irradiation has the effects of sterilization and preservation on chilled pork. This study has been confirmed that the application of electron beam irradiation is very useful for meat industry. (authors)

  18. Observation of electromagnetically induced Talbot effect in an atomic system

    Science.gov (United States)

    Zhang, Zhaoyang; Liu, Xing; Zhang, Dan; Sheng, Jiteng; Zhang, Yiqi; Zhang, Yanpeng; Xiao, Min

    2018-01-01

    The electromagnetically induced Talbot effect (EITE) resulting from the repeated self-reconstruction of a spatially intensity-modulated probe field is experimentally demonstrated in a three-level atomic configuration. The probe beam is launched into an optically induced lattice (established by the interference of two coupling fields) inside a rubidium vapor cell and is diffracted by the electromagnetically induced grating that was formed. The diffraction pattern repeats itself at the planes of integer multiple Talbot lengths. In addition, a fractional EITE is also investigated. The experimental observations agree well with the theoretical predictions. This investigation may potentially pave the way for studying the nonlinear and quantum dynamical features that have been predicted for established periodic optical systems.

  19. Effect of transients on the beam in the Superconducting Supercollider Coupled-Cavity Linac

    International Nuclear Information System (INIS)

    Young, L.M.; Nath, S.

    1992-01-01

    Each module of the Superconducting Super Collider (SSC) Coupled-Cavity Linac (CCL) consists of eight tanks (10 accelerating cells each) coupled with bridge couplers. The radio frequency (rf) power drive is in the center of the module at the bridge coupler between the fourth and fifth tanks. In this simulation of the beam dynamics, the rf power is turned on 10 μs before the beam is turned on. This time lapse allows the fields to build up and stabilize before they are required by the beam. When the beam is turned on, the beam loading causes the fields to change. This transient state of the fields together with their effect on the beam is presented. A model has been developed to calculate field distribution throughout the module as a function of time. Beam dynamics simulations were run with the results of this model at several times during the beam pulse. An estimate of the effect of the transients is given by the results of these simulations

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

    CERN Multimedia

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

  1. Beam diagnostics

    CERN Document Server

    Raich, U

    2008-01-01

    Most beam measurements are based on the electro-magnetic interaction of fields induced by the beam with their environment. Beam current transformers as well as beam position monitors are based on this principle. The signals induced in the sensors must be amplified and shaped before they are converted into numerical values. These values are further treated numerically in order to extract meaningful machine parameter measurements. The lecture introduces the architecture of an instrument and shows where in the treatment chain digital signal analysis can be introduced. Then the use of digital signal processing is presented using tune measurements, orbit and trajectory measurements as well as beam loss detection and longitudinal phase space tomography as examples. The hardware as well as the treatment algorithms and their implementation on Digital Signal Processors (DSPs) or in Field Programmable Gate Arrays (FPGAs) are presented.

  2. Effect of Physical Nonlinearity on Local Buckling in Sandwich Beams

    NARCIS (Netherlands)

    Koysin, V.; Shipsha, Andrey; Skvortsov, Vitaly

    2010-01-01

    This article deals with experimental, theoretical, and FE characterization of the local buckling in foam-core sandwich beams. In the theoretical approach, this phenomena is considered in a periodic formulation (unbounded wrinkle wave); a nonlinear stress—strain response of the face material is

  3. On the Relativistic Beaming and Orientation Effects in Core ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    γ, from the regression analyses ofR onD for any assumed model onceRT is known for a given source sample. This of course presupposes that the observed R−D correlation is entirely due to relativistic beaming. However, linear sizes of extragalactic radio sources have been known to undergo cosmological evolution (e.g., ...

  4. Effect of electron beam irradiation on the structure and optical ...

    Indian Academy of Sciences (India)

    developed as a suitable phosphor material for the application in near ultraviolet excited colour LEDs. Keywords. Nickel oxide; chemical precipitation; electron beam irradiation; band ... cations such as gas sensors,3 catalysts4–6 anode material in. Li ion batteries,7,8 nanoscale optoelectronic devices such as electrochromic ...

  5. Relativistic Beaming and Orientation Effects in BL Lacertae Objects

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We use the correlation between the core-to-lobe radio luminosity ratio () and the linear size () of a sample of BL Lacertae objects to investigate the relativistic beaming and radio source orientation paradigm for high peaked and low-peaked BL Lacs (X-ray and radio selected BL Lacs respectively) and to ...

  6. Effects of electron beam irradiation on tin dioxide gas sensors

    Indian Academy of Sciences (India)

    WINTEC

    Electron beam; irradiation; gas sensor; tin dioxide. 1. Introduction. The theory, fabrication and application of semiconducting gas sensors, has been well developed in the last thirty years. However, their limited selectivity and sensitivity are still problematic. The usual methods to improve gas sensing properties of SnO2 gas ...

  7. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    Science.gov (United States)

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-01-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry. PMID:27440516

  8. A novel electron beam-induced reaction of sulfonium salt in the crystalline state

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S.; Maekawa, Yasunari; Yoshida, Masaru [Department of Material Development, Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Takasaki, Gunma (Japan)

    2001-05-01

    The electron beam irradiation of triphenylsulfonium methanesulfonate in the crystalline state provides a new benzene-substitute sulfonium salt. This product has not been observed either by photolysis in the crystalline state nor by electron beam irradiation in a solution. The formation of the substitution product was confirmed by GC-MS analysis. (author)

  9. Organ/patient geometric variation in external beam radiotherapy and its effects

    International Nuclear Information System (INIS)

    Yan Di; Lockman, David

    2001-01-01

    Treatment variation in positioning of the organ/patient with respect to the radiation beams causes a temporal dose variation in critical normal tissues adjacent to the treatment target. This temporal variation induces uncertainties in understanding the normal tissue dose response, thereby limiting reliable treatment evaluation and optimization. The aim of this study is to model and analyze the temporal variation of organ dose distribution, and its effect on the biological effective dose. The study mainly focuses on the temporal dose variation caused by intertreatment organ motion/deformation and daily setup error. Sensitivity of the biological effective dose to organ/patient geometric variation, dose distribution, and treatment fractionation will be investigated. Significant deviation of the biological effective dose could be expected in a critical normal structure, even if the cumulative dose deviation in this structure is negligible. Patients with similar geometric variation characteristics can experience significantly different biological effective dose, and the differences are sensitive to the dose distribution and the total number of treatment fractions

  10. Reducing beam hardening effects and metal artefacts using Medipix3RX: With applications from biomaterial science

    CERN Document Server

    Rajendran, K; de Ruiter, N J A; Chernoglazov, A I; Panta, R K; Butler, A P H; Butler, P H; Bell, S T; Anderson, N G; Woodfield, T B F; Tredinnick, S J; Healy, J L; Bateman, C J; Aamir, R; Doesburg, R M N; Renaud, P F; Gieseg, S P; Smithies, D J; Mohr, J L; Mandalika, V B H; Opie, A M T; Cook, N J; Ronaldson, J P; Nik, S J; Atharifard, A; Clyne, M; Bones, P J; Bartneck, C; Grasset, R; Schleich, N; Billinghurst, M

    2014-01-01

    This paper discusses methods for reducing beam hardening effects using spectral data for biomaterial applications. A small-animal spectral scanner operating in the diagnostic energy range was used. We investigate the use of photon-processing features of the Medipix3RX ASIC in reducing beam hardening and associated artefacts. A fully operational charge summing mode was used during the imaging routine. We present spectral data collected for metal alloy samples, its analysis using algebraic 3D reconstruction software and volume visualisation using a custom volume rendering software. Narrow high energy acquisition using the photon-processing detector revealed substantial reduction in beam hardening effects and metal artefacts.

  11. Effect of releasing pretension for Rc Beams Bonded with Prestressed Fr Strip

    International Nuclear Information System (INIS)

    Chao-yang, Z.; Xue-jun, H.; Xing-guo, W.; Fei-fei, X

    2007-01-01

    In this paper, the effect of releasing pretension is theoretically and experimentally investigated for flexural members externally bonded with prestressed FRP laminate or near-surface-mounted with prestressed FRP plate or rod. The stresses of FRP on the interface and at cross sections of a beam are analyzed on the basis of linear elastic theory. The expressions are derived for effective prestress, prestress loss and camber at the midspan of the beam. Tests are performed on two reinforced concrete beams bonded with prestressed GFRP plate. The comparison between the analytical and the measured results shows the analyses in this paper are rational and correct. (author)

  12. Effect of electron beam on quality and physiological metabolism of blueberry

    International Nuclear Information System (INIS)

    Zhou Huijuan; Ye Zhengwen; Zhang Xueying; Su Mingshen; Du Jihong; Zhang Minqian

    2013-01-01

    In order to explore safe, simple and effective storage technology, experiment was conducted with 'ai li ao te' blueberry for studying the effect of electron beam on quality and physiological metabolism. Fruit was stored at temperature of (1 ± 0.5)℃, with RH of 80% ∼ 85%, and treated with electron beam of 0.5, 1, 1.5, 2, 3 kGy. The results showed that the proper dose of electron beam could decline the bad fruit rate and weightlessness, restrain respiration intensity, alleviate the decline of soluble solids, acid and Vc content. Meanwhile it did not have significant negative effects on pulp colour. All these showed that electron beam of 1 kGy treatment could keep the best storage quality of blueberry, keep the sound berry and weightlessness rate at > 90% and < 10% respectively, prolong the effective storage time from 30d to 60d. (authors)

  13. Beam Dynamics and Pulse Duration Control During Final Beam Bunching in Driver System for Heavy Ion Inertial Fusion

    CERN Document Server

    Kikuchi, Takashi; Katayama, Takeshi; Kawata, Shigeo; Nakajima, Mitsuo; Someya, Tetsuo

    2005-01-01

    Beam dynamics is investigated by multi-particle simulations during a final beam bunching in a driver system for heavy ion inertial fusion (HIF). The longitudinal bunch compression causes the beam instability induced by the strong space charge effect. The multi-particle simulation can indicate the emittance growth due to the longitudinal bunch compression. Dependence in the beam pulse duration is also investigated for effective pellet implosion in HIF. Not only the spatial nonuniformity of the beam illumination, but also the errors of the beam pulse duration cause changes of implosion dynamics. The allowable regime of the beam pulse duration for the effective fusion output becomes narrow with decreasing the input beam energy. The voltage accuracy requirement at the beam velocity modulator is also estimated for the final beam bunching. It is estimated that the integrated voltage error is allowable as a few percent.

  14. GPU-Powered Modelling of Nonlinear Effects due to Head-On Beam-Beam Interactions in High-Energy Hadron Colliders.

    CERN Document Server

    Furuseth, Sondre

    2017-01-01

    The performance of high-energy circular hadron colliders, as the Large Hadron Collider, is limited by beam-beam interactions. The strongly nonlinear force between the two opposing beams causes diverging Hamiltonians and resonances, which can lead to a reduction of the lifetime of the beams. The nonlinearity makes the effect of the force difficult to study analytically, even at first order. Numerical models are therefore needed to evaluate the overall effect of different configurations of the machines. This report discusses results from an implementation of the weak-strong model, studying the effects of head-on beam-beam interactions. The assumptions has been shown to be valid for configurations where the growth and losses of the beam are small. The tracking has been done using an original code which applies graphic cards to reduce the computation time. The bunches in the beams have been modelled cylindrically symmetrical, based on a Gaussian distribution in three dimensions. This choice fits well with bunches...

  15. Mask writing time explosion and its effect on CD control in e-beam lithography

    Science.gov (United States)

    Lee, Sang Hee; Choi, Jin; Min, Seong Jun; Kim, Hee Bom; Kim, Byung Gook; Woo, Sang-Gyun; Cho, Han-Ku

    2010-05-01

    As semiconductor features shrink in size and pitch, the extreme control of CD uniformity and MTT is needed for mask fabrication with e-beam lithography. And because of huge shot density of data, the writing time of e-beam lithography for mask fabrication will be increased rapidly in future design node. The beam drift caused by charging of optic system and current density drift can affect the beam size, position and exposure dose stability. From the empirical data, those are the function of writing time. Although e-beam lithography tool has the correction function which can be applied during writing, there are remained errors after correction which result in CD uniformity error. According to the writing time increasing, the residual error of correction will be more important and give the limit of CD uniformity and MTT. In this study, we study the beam size and exposure dose error as a function of time. Those are mainly caused by charging and current density drift. And we present the predicted writing time of e-beam lithography below 32nm node and estimate its effect on CD control error. From the relation between writing time and CD control error, we achieve the limit of CD uniformity with e-beam mask writer. And we suggest the method to achieve required CD uniformity at 22nm node and beyond.

  16. Development of phosphonic acid chelating fibers by means of electron beam irradiation induced graft polymerization technique

    International Nuclear Information System (INIS)

    Jyo, Akinori; Aoki, Shoji; Yamabe, Kazunori; Shuto, Taketomi

    2001-01-01

    Chloromethylstyrene was graft-polymerized onto polyethylene coated polypropylene fibers (0.9 denier) and its nonwoven cloth (1.5 denier) by means of electron beam irradiation induced graft polymerization technique. The grafted fiber and cloth were reacted with phosphorus trichloride in the presence of anhydrous aluminum trichloride under reflux of phosphorus trichloride, and the followed hydrolysis gave the objective phosphonic acid fibrous chelating exchangers FCSP-c (cloth type) and FCSP-f (fiber type) with phosphorus contents of 3.3 ± 0.2 mmol/g and acid capacities of 5.5 ± 0.2 meq/g. Adsorption rates of Pb(II), Cu(II) and Cd(II) by FCSP-c and FCSP-f were evaluated by batchwise and columnar methods, and compared with those by a chelating resin RCSP having the same functional groups. In batchwise and columnar adsorption of these metal ions, both FCSP-c and FCSP-f exhibited extremely higher adsorption rates than did the resin RCSP. For instance, FCSP-f packed columns exhibited flow rate independent breakthrough capacities of ca. 0.7-0.8 mmol/g for Cu(II) and Cd(II) within the tested range of flow rates from 50 to 1000 h -1 in space velocity, whereas breakthrough capacities of a RCSP resin packed one for Cu(II) decreased markedly with an increase in flow rate. For example, the breakthrough capacity of RCSP column at the flow rate of 500 h -1 was only ca. 0.2 mmol/g. (author)

  17. Flux threshold measurements of He-ion beam induced nanofuzz formation on hot tungsten surfaces

    International Nuclear Information System (INIS)

    Meyer, F W; Hijazi, H; Bannister, M E; Unocic, K A; Garrison, L M; Parish, C M

    2016-01-01

    We report measurements of the energy dependence of flux thresholds and incubation fluences for He-ion induced nano-fuzz formation on hot tungsten surfaces at UHV conditions over a wide energy range using real-time sample imaging of tungsten target emissivity change to monitor the spatial extent of nano-fuzz growth, corroborated by ex situ SEM and FIB/SEM analysis, in conjunction with accurate ion-flux profile measurements. The measurements were carried out at the multicharged ion research facility (MIRF) at energies from 218 eV to 8.5 keV, using a high-flux deceleration module and beam flux monitor for optimizing the decel optics on the low energy MIRF beamline. The measurements suggest that nano-fuzz formation proceeds only if a critical rate of change of trapped He density in the W target is exceeded. To understand the energy dependence of the observed flux thresholds, the energy dependence of three contributing factors: ion reflection, ion range and target damage creation, were determined using the SRIM simulation code. The observed energy dependence can be well reproduced by the combined energy dependences of these three factors. The incubation fluences deduced from first visual appearance of surface emissivity change were (2–4) × 10 23 m −2 at 218 eV, and roughly a factor of 10 less at the higher energies, which were all at or above the displacement energy threshold. The role of trapping at C impurity sites is discussed. (paper)

  18. Study of Genetics and Embryology of Polyembryonic Mutant of Autotetraploid Rice Induced by N+ Beam Implantation

    Science.gov (United States)

    Dai, Ximei; Huang, Qunce; Li, Guoping; Hu, Xiuming; Qin, Guangyong; Yu, Zengliang

    2006-11-01

    In the present study autotetraploid rice IR36-4X was treated by an ion implantation technique with nitrogen ion beams. A polyembryonic mutant (named IR36-Shuang) was identified in the M2 generation. The mutant line and its offspring were systematically investigated in regard to their major agronomic properties and the rate of polyembryonic seedling in the M3-M6 generation. The abnormal phenomena in the embryo sac development and the cytological mechanism of the initiation of additional embryo in IR36-Shuang were observed by Laser Scanning Confocal Microscopy. The results were as follows. 1) The plant height, the panicle length and 1000 grain weight of IR36-Shuang were lower than that of its control by 35.41%, 5.08% and 15.72% respectively, Moreover, the setting percentage decreased 12.39% compared with that in normal IR36-4X plants. 2) The polyembryonic trait of IR36-Shuang was genetically stable and the frequency of the polyembryonic seedlings in the IR36-Shuang line was also relatively stable. 3) The rate of abnormal embryo sacs in IR36-Shuang was significantly higher than that in the control IR36-4X. 4) The additional embryo in IR36-Shuang might arise from the double set of embryo sacs in a single ovary, antipodal cells or endosperm cells. These results suggest that IR36-Shuang is a polyembryonic mutant and a new apomixis rice line induced by low energy ion implantation. The prospects for the application in production of the IR36-Shuang line are also discussed. The present study may provide a basis for future investigations of apomixis rice breeding via the ion implantation biotechnology.

  19. Low-Temperature Electron Beam-Induced Transformations of Cesium Lead Halide Perovskite Nanocrystals

    Science.gov (United States)

    2017-01-01

    Cesium lead halide perovskite (CsPbX3, with X = Br, Cl, I) nanocrystals have been found to undergo severe modifications under the high-energy electron beam irradiation of a transmission electron microscope (80/200 keV). In particular, in our previous work, together with halogen desorption, Pb2+ ions were found to be reduced to Pb0 and then diffused to form lead nanoparticles at temperatures above −40 °C. Here, we present a detailed irradiation study of CsPbBr3 nanocrystals at temperatures below −40 °C, a range in which the diffusion of Pb0 atoms/clusters is drastically suppressed. Under these conditions, the irradiation instead induces the nucleation of randomly oriented CsBr, CsPb, and PbBr2 crystalline domains. In addition to the Br desorption, which accompanies Pb2+ reduction at all the temperatures, Br is also desorbed from the CsBr and PbBr2 domains at low temperatures, leading to a more pronounced Br loss, thus the final products are mainly composed of Cs and Pb. The overall transformation involves the creation of voids, which coalesce upon further exposure, as demonstrated in both nanosheets and nanocuboids. Our results show that although low temperatures hinder the formation of Pb nanoparticles in CsPbBr3 nanocrystals when irradiated, the nanocrystals are nevertheless unstable. Consequently, we suggest that an optimum combination of temperature range, electron energy, and dose rate needs to be carefully chosen for the characterization of halide perovskite nanocrystals to minimize both the Pb nanoparticle formation and the structural decomposition. PMID:28983524

  20. BEAM-BEAM SIMULATIONS FOR DOUBLE-GAUSSIAN BEAMS.

    Energy Technology Data Exchange (ETDEWEB)

    MONTAG, C.; MALITSKY, N.; BEN-ZVI, I.; LITVINENKO, V.

    2005-05-16

    Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-gaussian beams. Here we report the effect of low-frequency random tune modulations on diffusion in double-gaussian beams and compare the effects to those in beam-beam interactions with regular gaussian beams and identical tune shift parameters.

  1. BEAM-BEAM SIMULATIONS FOR DOUBLE-GAUSSIAN BEAMS

    International Nuclear Information System (INIS)

    MONTAG, C.; MALITSKY, N.; BEN-ZVI, I.; LITVINENKO, V.

    2005-01-01

    Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-gaussian beams. Here we report the effect of loW--frequency random tune modulations on diffusion in double-gaussian beams and compare the effects to those in beam-beam interactions with regular gaussian beams and identical tune shift parameters

  2. Beam-Beam Simulations for Double-Gaussian Beams

    CERN Document Server

    Montag, Christoph; Litvinenko, Vladimir N; Malitsky, Nikolay

    2005-01-01

    Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two Gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-Gaussian beams. Here we report the effect of low-frequency random tune modulations on diffusion in double-Gaussian beams and compare the effects to those in beam-beam interactions with regular Gaussian beams and identical tuneshift parameters.

  3. Electron-beam-assisted oxygen purification at low temperatures for electron-beam-induced pt deposits: towards pure and high-fidelity nanostructures.

    Science.gov (United States)

    Plank, Harald; Noh, Joo Hyon; Fowlkes, Jason D; Lester, Kevin; Lewis, Brett B; Rack, Philip D

    2014-01-22

    Nanoscale metal deposits written directly by electron-beam-induced deposition, or EBID, are typically contaminated because of the incomplete removal of the original organometallic precursor. This has greatly limited the applicability of EBID materials synthesis, constraining the otherwise powerful direct-write synthesis paradigm. We demonstrate a low-temperature purification method in which platinum-carbon nanostructures deposited from MeCpPtIVMe3 are purified by the presence of oxygen gas during a post-electron exposure treatment. Deposit thickness, oxygen pressure, and oxygen temperature studies suggest that the dominant mechanism is the electron-stimulated reaction of oxygen molecules adsorbed at the defective deposit surface. Notably, pure platinum deposits with low resistivity and retain the original deposit fidelity were accomplished at an oxygen temperature of only 50 °C.

  4. On beam quality and flatness of radiotherapy megavoltage photon beams

    International Nuclear Information System (INIS)

    Hossain, Murshed; Rhoades, Jeffrey

    2016-01-01

    Ratio of percentage depth dose (PDD) at two depths, PDD at a depth of 10 cm (PDD 10 ), and beam flatness are monitored regularly for radiotherapy beams for quality assurance. The purpose of this study is to understand the effects of changes in one of these parameters on the other. Is it possible to monitor only the beam flatness and not PDD? The investigation has two components. Naturally occurring i.e., unintended changes in PDD ratio and in-plane flatness for 6 and 10 MV photon beams for one particular Siemens Artiste Linac are monitored for a period of about 4 years. Secondly, deliberate changes in the beam parameters are induced by changing the bending magnet current (BMI). Relationships between various beam parameters for unintended changes as well as deliberate changes are characterized. Long term unintentional changes of PDD ratio are found to have no systematic trend. The flatness in the in plane direction for 6 and 10 MV beams show slow increase of 0.43 and 0.75 % respectively in about 4 years while the changes in the PDD ratio show no such trend. Over 10 % changes in BMI are required to induce changes in the beam quality indices at 2 % level. PDD ratio for the 10 MV beam is found to be less sensitive, while the depth of maximum dose, d max , is more sensitive to the changes in BMI compared to the 6 MV beam. Tolerances are more stringent for PDD 10 than PDD ratio for the 10 MV beam. PDD ratio, PDD 10 , and flatness must be monitored independently. Furthermore, off axis ratio alone cannot be used to monitor flatness. The effect of beam quality change in the absolute dose is clinically insignificant.

  5. Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Changyi [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Wu, Yiyong; Lv, Gang [National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin (China); Rubanov, Sergey [Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010 (Australia); Jamieson, David N., E-mail: d.jamieson@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2015-04-01

    Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

  6. The quantum measurement effect of interaction without interaction for an atomic beam

    Directory of Open Access Journals (Sweden)

    Yong-Yi Huang

    Full Text Available When an atomic beam collectively and harmonically vibrates perpendicular to the wave vector of the beam, the number of atoms reaching the atomic detector will have a vibrant factor Δt/T if the measurement time interval Δt is shorter than the period T. This new quantum mechanical measurement effect for an atomic beam is called interaction without interaction: though the translational motion of the atomic beam does not interact with its collective and transverse harmonic vibration, the latter will have an effect on the measured number of atoms associated with the former. From the new measurement effect the classical harmonic vibration’s period is evaluated. We give a clear physical picture and a satisfactory physical interpretation for the measurement effect based on the Copenhagen interpretation of quantum mechanics. We present an experimental proposal to verify this measurement effect for an ion beam instead of an atomic beam. Keywords: The quantum measurement effect of interaction without interaction, The Copenhagen interpretation of quantum mechanics

  7. Thermal and dynamic effects in electron beam welding cavities

    Energy Technology Data Exchange (ETDEWEB)

    Schauer, D.A.

    1977-08-01

    An experimental and analytical study of the temperature distributions along the molten metal surface in an electron beam welding cavity is described. Surface temperature distributions in cavities were measured with a narrow band infrared radiation pyrometer. The availability of the cavity temperature measurements allowed estimates to be made for the vapor pressure and surface energy forces as a function of cavity position. The results indicated a force imbalance occurred in the cavity. It is postulated that at the location of the force imbalance a liquid material projection forms periodically and moves into the path of the electron beam. The liquid in this projection is driven towards the bottom, partially filling the cavity. This action is followed by the electron beam pushing the liquid aside to form a maximum depth cavity. This process is then repeated. An analysis for predicting cavity oscillation frequency shows reasonable agreement with frequencies measured at the weld root determined from weld sections. A study of the measured temperature distributions in cavities of varying depth combined with the force imbalance observations led to an interpretation of when spiking might occur. A procedure is proposed for determining the spiking tendency for a given set of weld parameters. The results of this study permit a designer to select apriori the best set of weld parameters to achieve a weld of predictable quality.

  8. Thermal and dynamic effects in electron beam welding cavities

    International Nuclear Information System (INIS)

    Schauer, D.A.

    1977-08-01

    An experimental and analytical study of the temperature distributions along the molten metal surface in an electron beam welding cavity is described. Surface temperature distributions in cavities were measured with a narrow band infrared radiation pyrometer. The availability of the cavity temperature measurements allowed estimates to be made for the vapor pressure and surface energy forces as a function of cavity position. The results indicated a force imbalance occurred in the cavity. It is postulated that at the location of the force imbalance a liquid material projection forms periodically and moves into the path of the electron beam. The liquid in this projection is driven towards the bottom, partially filling the cavity. This action is followed by the electron beam pushing the liquid aside to form a maximum depth cavity. This process is then repeated. An analysis for predicting cavity oscillation frequency shows reasonable agreement with frequencies measured at the weld root determined from weld sections. A study of the measured temperature distributions in cavities of varying depth combined with the force imbalance observations led to an interpretation of when spiking might occur. A procedure is proposed for determining the spiking tendency for a given set of weld parameters. The results of this study permit a designer to select apriori the best set of weld parameters to achieve a weld of predictable quality

  9. Effects of electron beam irradiation on tribological and physico-chemical properties of Polyoxymethylene copolymer (POM-C)

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Md. Shahinur; Shaislamov, Ulugbek; Yang, Jong-Keun [Nuclear Fusion and Plasma Applications Laboratory, Department of Nuclear and Energy Engineering, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju 63243 (Korea, Republic of); Kim, Jong-Kuk [Plasma Processing Laboratory, Division of Surface Technology, Korea Institute of Materials Science, 797 Changwondaero, Sungsan-Gu, Changwon, Kyungnam 641-010 (Korea, Republic of); Yu, Young Hun [Department of Physics, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju 63243 (Korea, Republic of); Choi, Sooseok [Nuclear Fusion and Plasma Applications Laboratory, Department of Nuclear and Energy Engineering, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju 63243 (Korea, Republic of); Lee, Heon-Ju, E-mail: hjlee@jejunu.ac.kr [Nuclear Fusion and Plasma Applications Laboratory, Department of Nuclear and Energy Engineering, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju 63243 (Korea, Republic of)

    2016-11-15

    Highlights: • Electron beam dose irradiation effect on tribology of POM-C was investigated. • Raman and FTIR-ATR spectra confirm the chemical structural modification. • 1 MeV, 100 kGy dose irradiation induced well suited carbonization and hydrophobicity. • Well suited carbonization and hydrophobicity reduced friction coefficient. - Abstract: Polyoxymethylene copolymer (POM-C) is an attractive and widely used engineering thermoplastic across many industrial sectors owing to outstanding physical, mechanical, self-lubricating and chemical properties. In this research work, the POM-C blocks were irradiated with 1 MeV electron beam energy in five doses (100, 200, 300, 500 and 700 kGy) in vacuum condition at room temperature. The tribological and physico-chemical properties of electron beam irradiated POM-C blocks have been analyzed using pin on disk tribometer, Raman spectroscopy, FTIR-ATR, gel content analysis, SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy), surface profiler and contact angle analyzer. Electron beam irradiation at a dose of 100 kGy resulted in decrease of the friction coefficient of POM-C block due to well suited carbonization, cross-linking, free radicals formation and partial physical modification. It also showed the lowest surface roughness and highest water contact angle among all unirradiated and irradiated POM-C blocks. The irradiation dose at 200 kGy resulted in increase of friction coefficient due to less effective cross-linking, but the irradiation doses at 300, 500 and 700 kGy resulted in increase of the friction coefficient as compared to unirradiated POM-C block due to severe chain scission, chemical and physical structural degradation. The degree of improvement for tribological attribute relies on the electron beam surface dose delivered (energy and dose rate).

  10. Analysis of Beam-Beam Kink Instability in a Linac-Ring Electron-Ion Collider

    International Nuclear Information System (INIS)

    V. Lebedev; J. Bisognano; R. Li; B. Yunn

    2001-01-01

    A linac-ring collision scheme was considered in recent proposals of electron-gold colliders (eRHIC) and polarized-electron light-ion colliders (EPIC). The advantages of using an energy-recovered linac for the electron beam is that it avoids the limitation of beam-beam tune shift inherent in a storage ring, pertains good beam quality and easy manipulation of polarization. However, the interaction of the ion beam in the storage ring with the electron beam from the linac acts analogously to a transverse impedance, and can induce unstable behavior of the ion beam similar to the strong head-tail instability. In this paper, this beam-beam kink instability with head-tail effect is analyzed using the linearized Vlasov equation, and the threshold of transverse mode coupling instability is obtained

  11. External beam irradiation inhibits neointimal hyperplasia after injury-induced arterial smooth muscle cell proliferation

    International Nuclear Information System (INIS)

    Schaefer, U.; Micke, O.; Dorszewski, A.; Breithardt, G.; Willich, N.

    1996-01-01

    Purpose/Objective: Restenosis after catheter-based revascularization has been demonstrated to be primarily caused by smooth muscle cell proliferation. This study examines the effects of external beam irradiation on neointimal proliferation after external injury to the central artery of the rabbit ear. Materials and Methods: 30 male New Zealand White rabbits were used in this study. Crush lesions were performed on each ear under general anesthesia and bilateral auricular nerve blockade. A single dose of 12 Gy (n=10), 16 Gy (n=10), or 20 Gy (n=10) gamma radiation was delivered to the left or right central artery of the ear 24 hours after injury; the contralateral central artery served as control. All rabbits were sacrificed after twenty-one days and the central arteries of the ear were fixed for morphometric measurements. Results: Mean (± SD) neointimal area was 0.062 ± 0.005 mm 2 (12 Gy), 0.022 ± 0.005 mm 2 (16 Gy) and 0.028 ± 0.006 mm 2 in irradiated arteries compared with 0.081 ± 0.009 mm 2 in the control group. Mean (± SD) luminal area was 0.049 ± 0.004 mm 2 (12 Gy), 0.059 ± 0.002 mm 2 (16 Gy) and 0.072 ± 0.006 mm 2 (24 Gy) in irradiated arteries compared with 0.043 ± 0.008 mm 2 in the control group. The difference in neointimal and luminal area between control and irradiated arteries was significant (p<0.05) only for the 16 and 20 Gy group compared to control. Conclusion: We conclude that in this model, external beam X-ray irradiation was successful in reducing neointimal proliferation after injury of the central artery of the rabbit ear. Marked reductions in neointimal proliferation were demonstrated in vessels subjected to 16 and 20 Gy radiation, a less prominent effect was noted for 12 Gy. Whether this approach can be used successfully to inhibit restenosis in the clinical setting requires further investigation

  12. Modeling the biophysical effects in a carbon beam delivery line by using Monte Carlo simulations

    Science.gov (United States)

    Cho, Ilsung; Yoo, SeungHoon; Cho, Sungho; Kim, Eun Ho; Song, Yongkeun; Shin, Jae-ik; Jung, Won-Gyun

    2016-09-01

    The Relative biological effectiveness (RBE) plays an important role in designing a uniform dose response for ion-beam therapy. In this study, the biological effectiveness of a carbon-ion beam delivery system was investigated using Monte Carlo simulations. A carbon-ion beam delivery line was designed for the Korea Heavy Ion Medical Accelerator (KHIMA) project. The GEANT4 simulation tool kit was used to simulate carbon-ion beam transport into media. An incident energy carbon-ion beam with energy in the range between 220 MeV/u and 290 MeV/u was chosen to generate secondary particles. The microdosimetric-kinetic (MK) model was applied to describe the RBE of 10% survival in human salivary-gland (HSG) cells. The RBE weighted dose was estimated as a function of the penetration depth in the water phantom along the incident beam's direction. A biologically photon-equivalent Spread Out Bragg Peak (SOBP) was designed using the RBE-weighted absorbed dose. Finally, the RBE of mixed beams was predicted as a function of the depth in the water phantom.

  13. The effect of a single blade limiter on energetic neutral beam particles in Doublet III

    International Nuclear Information System (INIS)

    Petrie, T.W.; Armentrout, C.; Burrell, K.H.; Hino, T.; Kahn, C.; Kim, J.; Lohr, J.; Rottler, L.; Schissel, D.; St John, H.

    1984-01-01

    Energetic beam ion collisions with the main limiter can be a significant power loss process under certain operating conditions in Doublet III. Futhermore, these collisions may cause measurable damage to the limiter itself. Under low current and low toroidal field conditions (e.g., Isub(p) = 290 kA and Bsub(T) = 6.3 kG), 20-38% of the inferred absorbed beam power may be deposited directly on the ion drift side of the limiter by the beam ions. However, for higher plasma current and toroidal fields (e.g., Isub(p) = 480 kA and Bsub(t) = 15 kG), the fraction of inferred absorbed beam power deposited on the limiter is reduced to < 10%. Monte Carlo code simulations show that this loss of beam power is primarily a result of the large poloidal and toroidal gyro-orbits of the energetic beam ions. Other factors which may enhance beam ion losses to the limiter are (1) large separation distances between the primary limiter and the (outboard) vacuum vessel wall, and (2) plasma density buildup near the plasma edge during high gas puff operation. In addition, our data suggests enhanced plasma density and recycling near the limiter. This localized density can cause appreciable premature ionizations of the incoming beam neutrals and thus reduce the effective plasma heating of the beamline which is immediately upcurrent of the limiter. The prematurely-ionized beam particles from this adjacent beamline are responsible for much of the damage to the ion drift side of the limiter. We have found that under certain operating conditions (1) the direct beam heating of the limiter is 50% greater and (2) the stored plasma energy is 10% less when the beamline immediately upcurrent of the limiter heats the plasma. Thus, the relative positions of the limiters to the beamlines are important in designing future tokamaks. (orig.)

  14. Preliminary results on time-resolved ion beam induced luminescence applied to the provenance study of lapis lazuli

    International Nuclear Information System (INIS)

    Czelusniak, C.; Palla, L.; Massi, M.; Carraresi, L.; Giuntini, L.; Re, A.; Lo Giudice, A.; Pratesi, G.; Mazzinghi, A.; Ruberto, C.; Castelli, L.

    2016-01-01

    This work will present preliminary results concerning the use of time-resolved ion beam induced luminescence applied to provenance studies of lapis lazuli. Measurements were performed at the pulsed beam facility at LABEC laboratory in Florence. Lapis lazuli is a semi-precious gemstone, used as ornament since the early civilizations that can be found in few places on Earth. The importance of this work lies in understanding the origin of various samples of lapis lazuli, from which it may be possible to gain insight into trade routes from ancient times. The samples studied in this work originated from Chile, Afghanistan, Tajikistan, Myanmar, and Siberia. The stones were irradiated with 3 MeV protons and the resulting luminescence was detected by a photomultiplier tube, whose output was acquired using a sampling digitizer VME module (CAEN/V1720). Wavelength discrimination was performed at 430 nm utilizing a range of beam currents. The results showed that, by changing the beam current intensity, one can study different features of lapis lazuli, and this may aid in distinguishing lapis lazuli from different provenances.

  15. Stroboscopic image capture: Reducing the dose per frame by a factor of 30 does not prevent beam-induced specimen movement in paraffin

    Energy Technology Data Exchange (ETDEWEB)

    Typke, Dieter [Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gilpin, Christopher J. [Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390 (United States); Downing, Kenneth H. [Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Glaeser, Robert M. [Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States) and Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 (United States)]. E-mail: rmglaeser@lbl.gov

    2007-02-15

    Beam-induced specimen movement may be the major factor that limits the quality of high-resolution images of organic specimens. One of the possible measures to improve the situation that was proposed by Henderson and Glaeser [Ultramicroscopy 16 (1985) 139-150], which we refer to here as 'stroboscopic image capture', is to divide the normal exposure into many successive frames, thus reducing the amount of electron exposure-and possibly the amount of beam-induced movement-per frame. The frames would then be aligned and summed. We have performed preliminary experiments on stroboscopic imaging using a 200-kV electron microscope that was equipped with a high dynamic range Charge-coupled device (CCD) camera for image recording and a liquid N{sub 2}-cooled cryoholder. Single-layer paraffin crystals on carbon film were used as a test specimen. The ratio F(g)/F(0) of paraffin reflections, calculated from the images, serves as our criterion for the image quality. In the series that were evaluated, no significant improvement of the F {sub image}(g)/F {sub image}(0) ratio was found, even though the electron exposure per frame was reduced by a factor of 30. A frame-to-frame analysis of image distortions showed that considerable beam-induced movement had still occurred during each frame. In addition, the paraffin crystal lattice was observed to move relative to the supporting carbon film, a fact that cannot be explained as being an electron-optical effect caused by specimen charging. We conclude that a significant further reduction of the dose per frame (than was possible with this CCD detector) will be needed in order to test whether the frame-to-frame changes ultimately become small enough for stroboscopic image capture to show its potential.

  16. Stroboscopic image capture: Reducing the dose per frame by a factor of 30 does not prevent beam-induced specimen movement in paraffin

    International Nuclear Information System (INIS)

    Typke, Dieter; Gilpin, Christopher J.; Downing, Kenneth H.; Glaeser, Robert M.

    2007-01-01

    Beam-induced specimen movement may be the major factor that limits the quality of high-resolution images of organic specimens. One of the possible measures to improve the situation that was proposed by Henderson and Glaeser [Ultramicroscopy 16 (1985) 139-150], which we refer to here as 'stroboscopic image capture', is to divide the normal exposure into many successive frames, thus reducing the amount of electron exposure-and possibly the amount of beam-induced movement-per frame. The frames would then be aligned and summed. We have performed preliminary experiments on stroboscopic imaging using a 200-kV electron microscope that was equipped with a high dynamic range Charge-coupled device (CCD) camera for image recording and a liquid N 2 -cooled cryoholder. Single-layer paraffin crystals on carbon film were used as a test specimen. The ratio F(g)/F(0) of paraffin reflections, calculated from the images, serves as our criterion for the image quality. In the series that were evaluated, no significant improvement of the F image (g)/F image (0) ratio was found, even though the electron exposure per frame was reduced by a factor of 30. A frame-to-frame analysis of image distortions showed that considerable beam-induced movement had still occurred during each frame. In addition, the paraffin crystal lattice was observed to move relative to the supporting carbon film, a fact that cannot be explained as being an electron-optical effect caused by specimen charging. We conclude that a significant further reduction of the dose per frame (than was possible with this CCD detector) will be needed in order to test whether the frame-to-frame changes ultimately become small enough for stroboscopic image capture to show its potential

  17. An evaluation testing technique of single event effect using Beam Blanking SEM

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, J.; Hada, T.; Pesce, A.; Akutsu, T.; Matsuda, S. [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Igarashi, T.; Baba, S.

    1997-03-01

    Beam Blanking SEM (Scanning Electron Microscope) testing technique has been applied to CMOS SRAM devices to evaluate the occurence of soft errors on memory cells. Cross-section versus beam current and LET curves derived from BBSEM and heavy ion testing technique, respectively, have been compared. A linear relation between BBSEM current and heavy ion LET has been found. The purpose of this study was to demonstrate that the application of focused pulsed electron beam could be a reliable, convenient and inexpensive tool to investigate the effects of heavy ions and high energy particles on memory devices for space application. (author)

  18. Aberration of a negative ion beam caused by space charge effect.

    Science.gov (United States)

    Miyamoto, K; Wada, S; Hatayama, A

    2010-02-01

    Aberrations are inevitable when the charged particle beams are extracted, accelerated, transmitted, and focused with electrostatic and magnetic fields. In this study, we investigate the aberration of a negative ion accelerator for a neutral beam injector theoretically, especially the spherical aberration caused by the negative ion beam expansion due to the space charge effect. The negative ion current density profiles with the spherical aberration are compared with those without the spherical aberration. It is found that the negative ion current density profiles in a log scale are tailed due to the spherical aberration.

  19. The effect of atoms excited by electron beam on metal evaporation

    CERN Document Server

    Xie Guo Feng; Ying Chun Tong

    2002-01-01

    In atomic vapor laser isotope separation (AVLIS), the metal is heated to melt by electron beams. The vapor atoms may be excited by electrons when flying through the electron beam. The excited atoms may be deexcited by inelastic collision during expansion. The electronic energy transfers translational energy. In order to analyse the effect of reaction between atoms and electron beams on vapor physical parameters, such as density, velocity and temperature, direct-simulation Monte Carlo method (DSMC) is used to simulate the 2-D gadolinium evaporation from long and narrow crucible. The simulation results show that the velocity and temperature of vapor increase, and the density decreases

  20. In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

    CERN Document Server

    Yamamoto, T; Horiguchi, Y; Kishi, T; Kumada, H; Matsumura, A; Nose, T; Torii, Y; Yamamoto, K

    2002-01-01

    The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without sup 1 sup 0 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of sup 1 sup 0 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99+-0.24, 3.04+-0.19 and 1.43+-0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50+-0.32, 2.34+-0.30 and 2.17+-0.28 for EN...

  1. Correlation between beam on Winkler-Pasternak foundation and beam on elastic substrate medium with inclusion of microstructure and surface effects

    International Nuclear Information System (INIS)

    Limkatanyu, Suchart; Ponbunyanon, Paitoon; Prachasaree, Woraphot; Kuntiyawichai, Kittisak; Kwon, Min Ho

    2014-01-01

    A novel beam-elastic substrate element with inclusion of microstructure and surface energy effects is proposed in this paper. The modified couple stress theory is employed to account for the microstructure-dependent effect of the beam bulk material while GurtinMurdoch surface theory is used to capture the surface energy-dependent size effect. Interaction mechanism between the beam and the surrounding substrate medium is represented by the Winkler foundation model. The governing differential equilibrium and compatibility equations of the beam-elastic substrate system are consistently derived based on virtual displacement and virtual force principles, respectively. Both essential and natural boundary conditions of the system are also obtained. Two modified Tonti's diagrams are presented to provide the big picture of both displacement-based and force-based formulations of the system. Due to similarity between the current problem and the one related to the beam on Winkler-Pasternak foundation, the so-called 'natural' beam-Winkler-Pasternak foundation element coined by the authors is employed to perform two numerical simulations to study the characteristics and behaviors of a beam substrate system with inclusion of microstructure and surface effects.

  2. SU-E-T-211: Induced Release of Nanocarrier Encapsulated Chemotherapeutic Drugs Using Proton Radiotherapy Beams

    Energy Technology Data Exchange (ETDEWEB)

    Polf, J; Jackson, I [University of Maryland School of Medicine, Baltimore, MD (United States); Ranjan, A; Fernando, R [Oklahoma State University, Stillwater, OK (United States); Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States)

    2014-06-01

    Purpose: The purpose of this work was to develop and validate an open source independent MU dose calculation software for S and S IMRT based in the algorithm proposed by Kung et.al. Methods: Treatment plans were done using Iplan v4.5 BrainLAB TPS and S and S IMRT modality. A 6MV photon beam produced by a Primus linear accelerator equipped with an Optifocus MLC was used. TPS dose calculation algorithms were pencil beam and Monte Carlo. 230 IMRT treatments plans were selected for the study. The software was written under MALTLAB environment. Treatment plans were imported by the software using RTP format. Field fluences were reconstructed adding all segments.The algorithm implemented in the software calculates the dose at a reference point as the sum of primary and scatter dose. The primary dose is obtained by masking the fluence map with a circle of radius 1cm. The scatter dose is obtained through a shaped ring mask around the previous circle with a thickness of 0.5cm; the rings are increased one after another with constant thickness until cover the entire map of influence. The dosimetric parameters Sc, Sp and TPR vary depending on radio, the transmission effect of the MLC, inverse square law and dose profile are used for the calculation. Results: The average difference between measured and independent calculated dose was 0.4% ± 2.2% [−6.8%, 6.4%]. For 91% of the studied plans the difference was less than 3%. The difference between the measured and TPS dose with pencilbeam algorithm was 2.6% ± 1.41% [−2.0%, 5.6%] and Monte Carlo algorithm was 0.4% ± 1.5% [−4.9%, 3.7%]. The differences obtained are comparable to that obtained with the ionization chamber and TPS. Conclusion: The developed software is suitable for use in S and S IMRT dose calculation. This application is open and can be downloading under request.

  3. Study of the production of neutron-rich isotope beams issuing from fissions induced by fast neutrons

    International Nuclear Information System (INIS)

    Lau, Ch.

    2000-01-01

    This work is a contribution to the PARRNe project (production of radioactive neutron-rich isotopes). This project is based on the fission fragments coming from the fission of 238-uranium induced by fast neutrons. The fast neutron flux is produced by the collisions of deutons in a converter. Thick targets of uranium carbide and liquid uranium targets have been designed in order to allow a quick release of fission fragments. A device, able to trap on a cryogenic thimble rare gas released by the target, has allowed the production of radioactive nuclei whose half-life is about 1 second. This installation has been settled to different deuton accelerators in the framework of the European collaboration SPIRAL-2. A calibration experiment has proved the feasibility of fixing an ISOL-type isotope separator to a 15 MV tandem accelerator, this installation can provide 500 nA deutons beams whose energy is 26 MeV and be a valuable tool for studying fast-neutron induced fission. Zinc, krypton, rubidium, cadmium, iodine, xenon and cesium beams have been produced in this installation. The most intense beams reach 10000 nuclei by micro-coulomb for 26 MeV deutons. An extra gain of 2 magnitude orders can be obtained by using a more specific ion source and by increasing the thickness of the target. Another extra gain of 2 magnitude orders involves 100 MeV deutons

  4. Effect of ion beam energy on density, roughness & uniformity of Co film deposited using ion beam sputtering system

    Science.gov (United States)

    Dhawan, Rajnish; Rai, Sanjay; Lodha, G. S.

    2012-06-01

    Cobalt (Co) films were prepared, using ion beam sputtering technique. Films were prepared by varying beam voltage from 700 to 1100 V at room temperature. The influence of ion beam energy on the density, surface roughness and thickness uniformity of Co film was investigated. X-ray reflectivity study shows that surface roughness of film decreases with increasing beam energy and lowest surface roughness of 1.3 Å was achieved for 1000 V beam voltage at 4 cm3/min Ar gas flow. The density of the film was 93% of bulk density of Co. These ultra low roughness films are very promising for studying the magnetic properties of Co films.

  5. Effect of Electron Beam Irradiation on the Tensile Properties of Carbon Nanotubes Sheets and Yarns

    Science.gov (United States)

    Williams, Tiffany S.; Miller, Sandi G.; Baker, James S.; McCorkle, Linda S.; Meador, Michael A.

    2013-01-01

    Carbon nanotube sheets and yarns were irradiated using electron beam (e-beam) energy to determine the effect of irradiation dose on the tensile properties. Results showed that a slight change in tensile strength occurred after irradiating as-received CNT sheets for 20 minutes, and a slight decrease in tensile strength as the irradiation time approached 90 minutes. On the other hand, the addition of small molecules to the CNT sheet surface had a greater effect on the tensile properties of e-beam irradiated CNT sheets. Some functionalized CNT sheets displayed up to a 57% increase in tensile strength following 90 minutes of e-beam exposure. In addition, as-received CNT yarns showed a significant increase in tensile strength as the irradiation time increased.

  6. Automatic beam position control at Los Alamos Spallation Radiation Effects Facility (LASREF)

    International Nuclear Information System (INIS)

    Oothoudt, M.; Pillai, C.; Zumbro, M.

    1997-01-01

    Historically the Los Alamos Spallation Radiation Effects Facility (LASREF) has used manual methods to control the position of the 800 kW, 800 MeV proton beam on targets. New experiments, however, require more stringent position control more frequently than can be done manually for long periods of time. Data from an existing harp is used to automatically adjust steering magnets to maintain beam position to required tolerances

  7. Dynamic Effects on Chromaticity for the LHC beam cycle in the SPS

    CERN Document Server

    Wenninger, J

    2002-01-01

    During the energy ramp of the SPS the chromaticity is subject to significant dynamic effects. Sextupolar field errors due to eddy currents and remanent fields lead to beam momentum and ramp rate dependent corrections. Detailled measurements on the LHC beam cycle have been used to verify the modelling and reproducibility the chromaticity corrections. Large deviations were found between the presently used model and the measured chromaticity trims. An improved empirical model is suggested.

  8. The Effect of Spandrel Beam's Specification on Response Modification Factor of Concrete Coupled Shear Walls

    OpenAIRE

    Mussa Mahmoudi; seyed Mohammad Reza Mortazavi; Saeid Ajdari

    2016-01-01

    Response modification factor (R factor) is one of the seismic design parameters to be considered in evaluating the performance of buildings during strong motions. This paper has tried to evaluate the response modification factor of concrete coupled shear wall structures with various length/depth ratios of spandrel beams. The effect of diagonal reinforcement of spandrel beam was also evaluated on the R factor. The R factor directly depends on overstrength factor and ductility reduction factor....

  9. Effect of Steel Fiber and Different Environments on Flexural Behavior of Reinforced Concrete Beams

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Barkhordari Bafghi

    2017-09-01

    Full Text Available The main kind of deterioration in marine Reinforced Concrete (RC structures and other infrastructures is steel bar corrosion due to cracks in concrete surfaces, which leads to the reduction of the load carrying capacity, ductility, and structural safety. It seems that steel fibers can reduce and delay the cracking, and increase the flexural strength and ductility of marine RC structures. To do so, in marine atmosphere and the tidal zone of the Oman Sea and fresh water, the flexural behavior of beams containing Plain Concrete (PC, Concrete with Steel fiber Reinforcement (SFRC, RC, Concrete with Steel fiber, and bar Reinforcement ((R+SC at 28, 90 and 180 days were determined. Beams were 99 un-cracked and pre-cracked beams, with dimensions of 200 × 200 × 750 mm. Based on results and at 180 days, the flexural strength and toughness of pre-cracked (R+SC beams were 22%–43% higher than the pre-cracked RC beams. The effect of steel fiber on the increment of load capacity and the toughness of pre-cracked RC beams were approximately the same. By addition of steel fiber to un-cracked RC beams, load capacity and toughness were increased up to 20%. The load capacity and toughness in marine atmosphere and tidal zone were approximately 15% lower than the fresh water condition.

  10. Focused-ion-beam induced damage in thin films of complex oxide BiFeO3

    Directory of Open Access Journals (Sweden)

    W. Siemons

    2014-02-01

    Full Text Available An unexpected, strong deterioration of crystal quality is observed in epitaxial perovskite BiFeO3 films in which microscale features have been patterned by focused-ion-beam (FIB milling. Specifically, synchrotron x-ray microdiffraction shows that the damaged region extends to tens of μm, but does not result in measureable changes to morphology or stoichiometry. Therefore, this change would go undetected with standard laboratory equipment, but can significantly influence local material properties and must be taken into account when using a FIB to manufacture nanostructures. The damage is significantly reduced when a thin metallic layer is present on top of the film during the milling process, clearly indicating that the reduced crystallinity is caused by ion beam induced charging.

  11. Development of a PIXE (Particle Induced X-ray Emission) analysis device using an extracted proton beam

    International Nuclear Information System (INIS)

    Saidi, A.

    1989-01-01

    The experimental device described allows the extention of the PIXE (Particle Induced X-ray Emission) method to the analysis, by means of proton beams, of solid or liquid samples, which can not be analyzed under vacuum conditions. The homogeneity of the surfaces to be analysed and elements (in the atmosphere) which absorb X-rays must be taken into account. Liquid samples do not need special care. The results show that: at high energies, the extracted beam sensibility is of the same order of magnitude as those obtained under vacuum; at low energies, the performance under vacuum conditions is better. The particles energy losses, at the exit membrane and in the outer atmosphere, decrease the X-rays production efficiency [fr

  12. Improvement of AdCMV-GFP gene transfection efficiency induced by heavy-ion beam irradiation on murine melanoma cells

    International Nuclear Information System (INIS)

    Duan Xin; Min Fengling; Liu Bing; Zhou Qingming; Li Xiaoda; Wang Yanling; Chinese Academy of Sciences, Beijing; Zhang Hong; Qiu Rong; Hao Jifang; Zhou Guangming; Gao Qingxiang

    2007-01-01

    The effect of 12 C 6+ beam irradiation on AdCMV-GFP (a replication deficient recombinant adenoviral vector containing CMV promoter and green fluorescent protein) gene transfection efficiency for murine melanoma cell B16 has been investigated. B16 cells infected with AdCMV-GFP were irradiated by different doses of 12 C 6+ beam. The transfection efficiency was assessed by flow cytometry (FCM). Results show that 12 C 6+ beam irradiation can improve transfection efficiency of AdCMV-GFP on murine melanoma cell B16 in a dose-dependent manner. In addition, the transfection efficiency in pre-tranfection plus irradiation group is higher than that in pre-irradiation plus transfection group at the same dose irradiation dose. (authors)

  13. The Beam Spin Asymmetry and T-odd Effects

    Science.gov (United States)

    Banks, Daniel; Gamberg, Leonard

    2013-10-01

    The focus of this research is to model the internal structure of the nucleon based on its momentum and spin-polarization properties. We focus on the beam-spin asymmetry (BSA) in semi-inclusive deep inelastic scattering. When the produced pion's transverse momentum is on the order of quark intrinsic transverse momentum, TMD factorization suggest that the structure function for the BSA is a momentum convolution integral of transverse momentum dependent (TMD) parton distribution and fragmentation functions. Theoretically there are four possible structure functions. We focus on the naive time reversal odd (T-odd) contribution. Namely, the g⊥ TMD PDF which relates the transverse spin polarization and transverse momentum of quarks for the case of an unpolarized nucleon and longitudinally polarized electron beam. We model the BSA in the spectator model framework (L. Gamberg et al., Phys. Rev. D 77, 094016 (2008)) and calculate g⊥ and extend our earlier numerical work on the BSA for π+ to results for π-, π0, production. We present these new results for the BSA and compare them with the recent results from CLAS, Hall B collaboration at JLAB (M. Aghasyan, H. Avakian et al., Phys. Lett. B 704, 397 (2011)).

  14. Effect of Electron Beam Irradiation on the Structure and Optical Properties of Poly (vinyl alcohol)

    International Nuclear Information System (INIS)

    Abutalib, M.M.

    2011-01-01

    Samples from of the polymeric material poly (vinyl alcohol) PVA have been exposed to electron beam in the dose range 5-100 kGy. The modifications induced in PVA samples due to electron beam irradiation have been studied through different characterization techniques such as X-ray diffraction XRD, Fourier Transform Infrared spectroscopy FTIR and color difference studies. The FTIR spectroscopy indicated that the degradation is the dominant mechanism at the dose range 5-60 kGy. Above 60 and up to 100 kGy, crosslinking is achieved. The crosslinking reported by FTIR spectroscopy destroyed the degree of ordering in the PVA samples as revealed by XRD. Additionally, the non irradiated PVA samples showed significant color sensitivity towards electron beam irradiation that appeared in the increase of the green and blue color components. This was accompanied by a net increase in the darkness of the samples

  15. Effect of discrete glass fibers on the behavior of R.C. Beams exposed to fire

    Directory of Open Access Journals (Sweden)

    Magdy Riad

    2017-08-01

    Full Text Available The main objective of this paper is to investigate the effect of adding discrete glass fibers on the behavior of reinforced concrete (RC beams under different fire and cooling conditions. Eighteen beams with different concrete compressive strengths were tested to study the behavior of reinforced concrete (RC beams containing discrete glass fibers when exposed to different fire and cooling conditions. Nine beams were prepared from normal strength concrete (NSC with compressive strength equal to 35 MPa while the other beams were prepared from high strength concrete (HSC with compressive strength equal to 60 MPa. The beams contained different contents of discrete glass fibers. The modes of failure of tested specimens show that the crack patterns change according to fire condition and fiber content. Analysis of test results show that adding discrete glass fibers to NSC increased the residual stiffness of the tested specimens after firing and decreased the rate of the deflection gain during firing. Also adding fibers to concrete has a limited positive effect on the ultimate strength of the specimens compared to the control specimens. Its effect on deflection due to fire is more pronounced. Finally, the recommended optimum ratio of discrete glass fibers is not more than 0.5% of the total concrete weight.

  16. Numerical simulations on conformable laser-induced interstitial thermotherapy through combined use of multi-beam heating and biodegradable nanoparticles.

    Science.gov (United States)

    Zhang, Jie; Jin, Chao; He, Zhi-Zhu; Liu, Jing

    2014-07-01

    Clinically, precisely heating and thus completely ablating diseased tumor tissue through laser beam is still facing many technical challenges. In this study, numerical simulation of a conformal heating modality based on multi-beam laser along with biodegradable magnesium nanoparticles (Mg-NPs) was put forward to treat liver tumor with large size or irregular shape. Further, a Gaussian-like distribution was proposed to investigate the influence of Mg-NP deposition on the nanoenhanced laser-induced interstitial thermotherapy (LITT). A temperature feedback system was adopted to control the temperature range to avoid overheating. To preliminarily validate the heating enhancement induced by the applied multi-beam laser and Mg-NPs, a conceptual experiment was performed. Both theoretical simulation and experimental measurements demonstrated that multi-beam laser with Mg-NPs could improve efficiency in the conformal heating of tumors with irregular shape or large size. In addition, the distribution and content of Mg-NPs produced significant impact on thermotherapy: (1) The adjustable parameter σ in the Gaussian-like distribution could reflect various practical situations and diffusivities of Mg-NPs; (2) under the premise of the same concentration of Mg-NPs and short time to heat a small-sized target, the whole liver tumor containing Mg-NPs could not improve the efficiency as the nanoparticles limited the photons to be absorbed only around the fibers, while liver tumor partially containing Mg-NPs could improve the thermotherapy efficiency up to 20 %; and (3) the addition of Mg-NPs was rather beneficial for realizing a conformal heating as the residual thermal energy was much less than that without Mg-NPs. This study suggests a feasible and promising modality for planning a high-performance LITT in future clinics.

  17. Effects of Cross-Linking on the Hydrostatic Pressure Testing for HDPE Pipe Material using Electron Beam Machine

    International Nuclear Information System (INIS)

    Mohd Jamil Bin Hashim

    2011-01-01

    One of the most inventive, sustainable strategies used in engineering field is to improve the quality of material and minimize production cost of material for example in this paper is HDPE material. This is because HDPE is an oil base material. This paper proposes to improve its hydrostatic pressure performance for HDPE pipe. The burst test is the most direct measurement of a pipe materials resistance to hydrostatic pressure. Test will be conducted in accordance with ASTM standard for HDPE pipe that undergo electron beam irradiation cross-linking. Studies show the effect of electron beam irradiation will improve the mechanical properties of HDPE pipe. When cross-linking is induced, the mechanical properties such as tensile strength and young modulus is increase correspond to the radiation dose. This happen because the structure of HDPE, which is thermoplastic change to thermosetting. This will indicate the variability of irradiation dose which regard to the pipe pressure rating. Hence, the thickness ratio of pipe will be re-examining in order to make the production of HDPE pipe become more economical. This research review the effects of electron beam on HDPE pipe, as well as to reduce the cost of its production to improve key properties of selected plastic pipe products. (author)

  18. Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

    International Nuclear Information System (INIS)

    Thongkumkoon, P.; Prakrajang, K.; Thopan, P.; Yaopromsiri, C.; Suwannakachorn, D.; Yu, L.D.

    2013-01-01

    Highlights: ► Detected X-ray emission from metal, plastic and biological samples. ► Characteristic X-ray emission was detected from metal but not from non-metals. ► Low-energy ion bombarded bacteria held in different sample holders. ► Bacteria held in metal holder had higher mutation rate than in plastic holder. ► Ion-beam-induced X-ray from biological sample is not a basic mutation source. -- Abstract: Low-energy ion beam biotechnology has achieved tremendous successes in inducing crop mutation and gene transfer. However, mechanisms involved in the related processes are not yet well understood. In ion-beam-induced mutation, ion-bombardment-produced X-ray has been proposed to be one of the secondary mutation sources, but the speculation has not yet been experimentally tested. We carried out this investigation to test whether the low-energy ion-beam-produced X-ray was a source of ion-beam-induced mutation. In the investigation, X-ray emission from 29-keV nitrogen- or argon- ion beam bombarded bacterial Escherichia coli (E. coli) cells held in a metal or plastic sample holder was in situ detected using a highly sensitive X-ray detector. The ion beam bombarded bacterial cells held in different material holders were observed for mutation induction. The results led to a conclusion that secondary X-ray emitted from ion-beam-bombarded biological living materials themselves was not a, or at least a negligible, mutational source, but the ion-beam-induced X-ray emission from the metal that made the sample holder could be a source of mutation