WorldWideScience

Sample records for beam induced effects

  1. Simulation of beam-induced plasma for the mitigation of beam-beam effects

    Energy Technology Data Exchange (ETDEWEB)

    Ma, J.; Wang, G.; Samulyak, R.; Yu, K.; Litvinenko, V.

    2015-05-03

    One of the main challenges in the increase of luminosity of circular colliders is the control of the beam-beam effect. In the process of exploring beam-beam mitigation methods using plasma, we evaluated the possibility of plasma generation via ionization of neutral gas by proton beams, and performed highly resolved simulations of the beam-plasma interaction using SPACE, a 3D electromagnetic particle-in-cell code. The process of plasma generation is modelled using experimentally measured cross-section coefficients and a plasma recombination model that takes into account the presence of neutral gas and beam-induced electromagnetic fields. Numerically simulated plasma oscillations are consistent with theoretical analysis. In the beam-plasma interaction process, high-density neutral gas reduces the mean free path of plasma electrons and their acceleration. A numerical model for the drift speed as a limit of plasma electron velocity was developed. Simulations demonstrate a significant reduction of the beam electric field in the presence of plasma. Preliminary simulations using fully-ionized plasma have also been performed and compared with the case of beam-induced plasma.

  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. Fundamental edge broadening effects during focused electron beam induced nanosynthesis

    OpenAIRE

    Roland Schmied; Fowlkes, Jason D.; Robert Winkler; Rack, Phillip D; Harald Plank

    2015-01-01

    The present study explores lateral broadening effects of 3D structures fabricated through focused electron beam induced deposition using MeCpPt(IV)Me3 precursor. In particular, the scaling behavior of proximity effects as a function of the primary electron energy and the deposit height is investigated through experiments and validated through simulations. Correlated Kelvin force microscopy and conductive atomic force microscopy measurements identified conductive and non-conductive proximity r...

  4. Focused Ion Beam Induced Effects on MOS Transistor Parameters

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-07-28

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

  5. Beam-Beam Effects

    OpenAIRE

    Herr, W; Pieloni, T.

    2016-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  6. Beam-Beam Effects

    CERN Document Server

    Herr, W

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  7. Beam-beam effects

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A.

    1994-12-01

    The term beam-beam effects is usually used to designate different phenomena associated with interactions of counter-rotating beams in storage rings. Typically, the authors speak about beam-beam effects when such interactions lead to an increase of the beam core size or to a reduction of the beam lifetime or to a growth of particle`s population in the beam halo and a correspondent increase of the background. Although observations of beam-beam effects are very similar in most storage rings, it is very likely that every particular case is largely unique and machine-dependent. This constitutes one of the problems in studying the beam-beam effects, because the experimental results are often obtained without characterizing a machine at the time of the experiment. Such machine parameters as a dynamic aperture, tune dependencies on amplitude of particle oscillations and energy, betatron phase advance between the interaction points and some others are not well known, thus making later analysis uncertain. The authors begin their discussion with demonstrations that beam-beam effects are closely related to non linear resonances. Then, they will show that a non linearity of the space charge field is responsible for the excitation of these resonances. After that, they will consider how beam-beam effects could be intensified by machine imperfections. Then, they will discuss a leading mechanism for the formation of the beam halo and will describe a new technique for beam tails and lifetime simulations. They will finish with a brief discussion of the coherent beam-beam effects.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-01

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

  9. Effect of induced spatial incoherence on flow induced laser beam deflection: Analytic theory

    International Nuclear Information System (INIS)

    Analytic results are presented for the laser beam deflection rate in the case of spatial and temporal smoothing by induced spatial incoherence (ISI). It is shown that for flow perpendicular to the beam propagation direction with Mach number M, temporal smoothing decreases the beam deflection rate for M>1, but may increase it for M<1 and weak acoustic wave damping. copyright 1997 American Institute of Physics

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

    International Nuclear Information System (INIS)

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

  11. Low level RF systems for synchrotrons part II: High Intensity. Compensation of the beam induced effects

    CERN Document Server

    Baudrenghien, P

    2005-01-01

    The high intensity regime is reached when the voltage induced by the beam in the RF cavities is of an amplitude comparable to the desired accelerating voltage. In steady state this beam loading can be compensated by providing extra RF power. Transient beam loading occurs at injection or in the presence of a beam intensity that is not uniform around the ring. The transients are periodic at the revolution frequency. Without correction transient beam loading can be very harmful: The stable phase and bucket area will not be equal for all bunches. Strong beam loading often goes in pair with longitudinal instabilities because the RF cavities are a large contributor to the total ring impedance. The low level systems that reduce the effect of the transient beam loading will also increase the threshold intensity of the longitudinal instability caused by the cavity impedance at the fundamental RF frequency. Four classic methods are presented here: Feedforward, RF feedback, long delay feedback and bunch by bunch feedbac...

  12. Irradiation effect on zooplankton eggs applied by bremsstrahlung induced from pulsed intense electron beam

    International Nuclear Information System (INIS)

    We have considered an irradiation effect on zooplankton eggs applied by bremsstrahlung induced from pulsed intense electron beam. Zooplankton eggs about 200 have been successfully inactivated using a bremsstrahlung at 3 kGy. We found that 63.9% of zooplankton eggs are inactivated by bremsstrahlung irradiation. It was the increase of 30 points in comparisons with 33.3% of zooplankton eggs inactivated for non-irradiation case. (author)

  13. Effect of smoothing by spectral dispersion on flow induced laser beam deflection: The random phase modulation scheme

    International Nuclear Information System (INIS)

    Analytical results are presented for the effect of random phase modulated smoothing by spectral dispersion on flow induced laser beam deflection. It is shown that in the limit of a large number of color cycles, Ncc, the effect is identical to that of the induced spatial incoherence method of temporal smoothing. For small Ncc, the beam deflection rate may be significantly larger in the direction perpendicular to the dispersion, than in the parallel direction. copyright 1998 American Institute of Physics

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

    International Nuclear Information System (INIS)

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

  15. Beam-induced Electron Loading Effects in High Pressure Cavities for a Muon Collider

    Energy Technology Data Exchange (ETDEWEB)

    Chung, M.; Tollestrup, A.; Jansson, A.; Yonehara, K.; /Fermilab; Insepov, Z.; /Argonne

    2010-05-01

    Ionization cooling is a critical building block for the realization of a muon collider. To suppress breakdown in the presence of the external magnetic field, an idea of using an RF cavity filled with high pressure hydrogen gas is being considered for the cooling channel design. One possible problem expected in the high pressure RF cavity is, however, the dissipation of significant RF power through the beam-induced electrons accumulated inside the cavity. To characterize this detrimental loading effect, we develop a simplified model that relates the electron density evolution and the observed pickup voltage signal in the cavity, with consideration of several key molecular processes such as the formation of the polyatomic molecules, recombination and attachment. This model is expected to be compared with the actual beam test of the cavity in the MuCool Test Area (MTA) of Fermilab.

  16. Electron beam induced synthesis of uranium dioxide nanoparticles: Effect of solvent composition

    Science.gov (United States)

    Rath, M. C.; Keny, S. J.; Naik, D. B.

    2016-09-01

    The effect of various compositions of solvents was investigated on the electron beam induced synthesis of uranium dioxide, UO2 nanoparticles. The synthesis was carried out at different pHs from 2 to 7 in the aqueous solutions containing 10 mM uranyl nitrate and 10% 2-propanol. The formation of UO2 nanoparticles was found to occur only in the pH range from 2.5 to 3.7. Experiments were also carried out in the aqueous solutions containing various other alcohols (10% v/v) such as methanol, ethanol, 1-propanol, 1-butanol or tert-butanol as well as in solutions containing 10 mM sodium formate at pH 3.4. The formation of UO2 nanoparticles in the aqueous solutions was found to occur only in the presence of ethanol, 1-propanol, 2-propanol or 1-butanol. It is therefore confirmed that the electron beam induced synthesis of UO2 nanoparticles strongly depends on the solvent compositions as well as the pH of the medium.

  17. 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.

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

    International Nuclear Information System (INIS)

    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 TiO2 in the well-known Rutile phase. The laser irradiated areas on the film acquired selective (upon recording polarization) holographic reflectance

  19. Ion beam induced effects at 15 K in z-cutLiNbO3

    International Nuclear Information System (INIS)

    The primary effects of the damage formation in z-cut LiNbO3 due to ion irradiation was investigated. Therefor the samples were irradiated stepwise and subsequently measured by means of Rutherford backscattering spectrometry (RBS) at 15 K without changing the temperature of the sample. The irradiation was done with 30 keV H-, 50 keV Li-, 160 keV O- and 350 keV Ar-ions at ion fluences between 5 x 1011 cm-2 and 2 x 1017 cm-2. The RBS measurements were performed with 1.4 MeV He-ions in steps of equal charges providing a series of subspectra. It was observed that the backscattering yield of the damaged region decreases with increasing number of subspectra indicating an annealing of defects as a consequence of the RBS measurement. The energy deposited into electronic processes by the analyzing He beam is mostly responsible for the observed defect annealing. The amount of annealing depends on the defect concentration and the ion species. The undisturbed defect accumulation which will be observed without any effect of measurement was calculated for the different ion species by an analytical formula taking into account the He-beam induced annealing

  20. Chemical effects induced by low-energy particle beams in fluorozirconate glasses

    International Nuclear Information System (INIS)

    The modification of the chemical structure of fluorozirconate glasses (ZBLAN) with Ar ion and atom beams of low energy (2-10keV) has been studied in comparison with the damage produced in the starting polycrystalline ZrF4 and BaF2. A variety of reduced chemical states of Zr is produced in ZrF4 as well as in ZBLAN glasses, including metallic Zr0State. A strong enhancement of the amount of the metallic Zr formed under irradiation is observed in ZBLAN, while it is present only as trace in the irradiated pure ZrF4 samples. The reported effect is tentatively attributed to the presence of Ba ions in the glass network which could prompt the self-trapping of radiation-induced defects at the Zr sites, involving their progressive reduction

  1. Electromagnetically Induced Transparency versus Nonlinear Faraday Effect. Coherent Control of the Light Beam Polarization

    CERN Document Server

    Drampyan, R; Gawlik, W

    2009-01-01

    We report on experimental and theoretical study of the nonlinear Faraday effect under conditions of electromagnetically induced transparency at the 5$S_{1/2} \\to 5P_{3/2} \\to 5D_{5/2}$ two-photon transition in rubidium vapors. These transitions realize the inverted Y model which combines the $\\Lambda$ and ladder systems. Strong nonlinearity allowing for large rotation angles of a probe beam tuned to the $S\\to P$ transition was obtained by creation of quantum superpositions of magnetic sublevels (Zeeman coherences) in the rubidium ground state ($\\Lambda$ scheme). Additionally, electromagnetically induced transparency was accomplished in a ladder scheme by acting with an additional strong coupling laser on the $P\\to D$ transition. Under conditions of a two-photon resonance the rotation was significantly reduced, which is interpreted as a competition between the two processes. The effect was observed in sub-Gauss magnetic fields and could be used for efficient coherent control of generation of the ground-state c...

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

    DEFF Research Database (Denmark)

    van Dorp, W. F.; Beyer, A.; Mainka, M.; Gölzhäuser, A.; Hansen, Thomas Willum; Wagner, Jakob Birkedal; Hagen, C. W.; De Hosson, J. Th. M.

    2013-01-01

    The current understanding in the study of focused electron beam induced processing (FEBIP) is that the growth of a deposit is mainly the result of secondary electrons (SEs). This suggests that the growth rate for FEBIP is affected by the SE emission from the support. Our experiments, with membranes...

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

    Indian Academy of Sciences (India)

    Manoj Mishra; Swapan Konar

    2005-09-01

    We have presented an investigation of the induced focusing in Kerr media of two laser beams, the pump beam and the probe beam, which could be either Gaussian or elliptic Gaussian or a combination of the two. We have used variational formalism to derive relevant beam-width equations. 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. In case both beams are elliptic Gaussian, we have shown that when power of both beams is above a certain threshold value then the effective radius of both beams collapses and collapse distance depends on power. Moreover, it has been found that induced focusing can be employed to convert a circular Gaussian beam into an elliptic Gaussian beam.

  4. Laser induced bubbles inside liquids: Transient optical properties and effects on a beam propagation

    International Nuclear Information System (INIS)

    Light transmission through a laser formed bubble (LFB) following ablation of a metallic target inside water was studied. During the early expansion and late collapsing phases, the refraction index nb of the hot high-pressure vapor bubble is higher than 1.23 and close to that of the surrounding liquid. The cavity growth lowers nb down to 1.00 and causes strong defocusing of the incident laser beam with consequent enlargement of the ablation crater diameter, here overcoming factor two. Inhomogeneous water vapor clustering inside the cool expanded bubble further perturbs the light transmission and induces irregular ablation by the successive laser pulse.

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

    International Nuclear Information System (INIS)

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

  6. 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...... Monte Carlo simulations show that the SE yield changes strongly with substrate thickness for thicknesses below the SE escape depth. However, our experimental results show that the growth rate is independent of the substrate thickness. Deposits with an average size of about 3 nm were written on 1 and 9...... nm thick carbon substrates. The apparent contradiction between simulation and experiment is explained by simulating the SE emission from a carbon substrate with platinum deposits on the surface. It appears that the SE emission is dominated by the deposits rather than the carbon substrate, even for...

  7. Study on the bias-dependent effects of proton-induced damage in CdZnTe radiation detectors using ion beam induced charge microscopy.

    Science.gov (United States)

    Gu, Yaxu; Jie, Wanqi; Rong, Caicai; Xu, Lingyan; Xu, Yadong; Lv, Haoyan; Shen, Hao; Du, Guanghua; Guo, Na; Guo, Rongrong; Zha, Gangqiang; Wang, Tao; Xi, Shouzhi

    2016-09-01

    The influence of damage induced by 2MeV protons on CdZnTe radiation detectors is investigated using ion beam induced charge (IBIC) microscopy. Charge collection efficiency (CCE) in irradiated region is found to be degraded above a fluence of 3.3×10(11)p/cm(2) and the energy spectrum is severely deteriorated with increasing fluence. Moreover, CCE maps obtained under the applied biases from 50V to 400V suggests that local radiation damage results in significant degradation of CCE uniformity, especially under low bias, i. e., 50V and 100V. The CCE nonuniformity induced by local radiation damage, however, can be greatly improved by increasing the detector applied bias. This bias-dependent effect of 2MeV proton-induced radiation damage in CdZnTe detectors is attributed to the interaction of electron cloud and radiation-induced displacement defects. PMID:27399802

  8. Modelling of electron beam induced nanowire attraction

    Science.gov (United States)

    Bitzer, Lucas A.; Speich, Claudia; Schäfer, David; Erni, Daniel; Prost, Werner; Tegude, Franz J.; Benson, Niels; Schmechel, Roland

    2016-04-01

    Scanning electron microscope (SEM) induced nanowire (NW) attraction or bundling is a well known effect, which is mainly ascribed to structural or material dependent properties. However, there have also been recent reports of electron beam induced nanowire bending by SEM imaging, which is not fully explained by the current models, especially when considering the electro-dynamic interaction between NWs. In this article, we contribute to the understanding of this phenomenon, by introducing an electro-dynamic model based on capacitor and Lorentz force interaction, where the active NW bending is stimulated by an electromagnetic force between individual wires. The model includes geometrical, electrical, and mechanical NW parameters, as well as the influence of the electron beam source parameters and is validated using in-situ observations of electron beam induced GaAs nanowire (NW) bending by SEM imaging.

  9. Analyses on Radiation Effects in Solid Amino Acids Induced by Low Energy Fe~+ Ion Beams

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Radiation effects in Solid samples of L(+)-cysteine and L(+)-cysteine hydroehloride monohydrate induced by 110 keV Fe~+ion implantation were characterized with FTIR, ESR,HPLC and ESI-FTMS.It was validated that solid samples of the irradiated amino acids were damaged to a certain extent,and some new groups or molecular products formed.

  10. Substrate effects on the electron-beam-induced deposition of platinum from a liquid precursor

    Science.gov (United States)

    Donev, Eugenii U.; Schardein, Gregory; Wright, John C.; Hastings, J. Todd

    2011-07-01

    Focused electron-beam-induced deposition using bulk liquid precursors (LP-EBID) is a new nanofabrication technique developed in the last two years as an alternative to conventional EBID, which utilizes cumbersome gaseous precursors. Furthermore, LP-EBID using dilute aqueous precursors has been demonstrated to yield platinum (Pt) nanostructures with as-deposited metal content that is substantially higher than the purity achieved by EBID with currently available gaseous precursors. This advantage of LP-EBID--along with the ease of use, low cost, and relative innocuousness of the liquid precursors--holds promise for its practical applicability in areas such as rapid device prototyping and lithographic mask repair. One of the feasibility benchmarks for the LP-EBID method is the ability to deposit high-fidelity nanostructures on various substrate materials. In this study, we report the first observations of performing LP-EBID on bare and metal-coated silicon-nitride membranes, and compare the resulting Pt deposits to those obtained by LP-EBID on polyimide membranes in terms of nucleation, morphology, size dependence on electron dose, and purity.

  11. Effect of solubility parameter of monomers on electron beam induced graft-polymerization onto polyethylene films

    International Nuclear Information System (INIS)

    Electron beam induced graft-polymerization by the mutual irradiation technique of monomers with different solubility parameters δ onto low density polyethylene films (LDPE) and high density polyethylene films (HDPE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic ratios of surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of monomers, and grafting rates onto LDPE were larger than those onto HDPE. Graft chain contents on surface, which were evaluated in terms of surface tensions and atomic ratios of the surface, increased with increasing δ of monomers, and graft chain contents on surface of HDPE were higher than those of LDPE. It is assumed that mutual solubility of PE and monomers, i.e., infiltration of monomers into PE during graft-polymerization influence grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

  12. Effect of solubility parameter of solvents on electron beam induced graft-polymerization onto polyethylene films

    International Nuclear Information System (INIS)

    Electron beam induced graft-polymerization by the mutual irradiation technique of methyl methacrylate (MMA) and methacrylic acid (MAAc) blended with solvents, which have different solubility parameters δ, onto high density polyethylene films (PE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic rations on the surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of solvents, and grafting rates for MMA were larger than those for MAAc. Graft chain contents on the surface, which were evaluated in terms of surface tensions and atomic ratios on the surface, increased with increasing δ of solvents, and graft chain contents on the surface of MAAc grafted PE were higher than those of MMA grafted PE. It is assumed that mutual solubility of PE and solvents (monomer solutions), i.e., infiltration of monomer solutions into PE during graft-polymerization, influenced grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

  13. 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.

  14. Electron beam induced growth of tin whiskers

    International Nuclear Information System (INIS)

    We have investigated the influence of electron irradiation on tin whisker growth. Sputtered tin samples exposed to electron beam of 6 MeV energy exhibited fast whisker growth, while control samples did not grow any whiskers. The statistics of e-beam induced whiskers was found to follow the log-normal distribution. The observed accelerated whisker growth is attributed to electrostatic effects due to charges trapped in an insulating substrate. These results offer promise for establishing whisker-related accelerated life testing protocols

  15. Electron beam induced growth of tin whiskers

    Science.gov (United States)

    Vasko, A. C.; Warrell, G. R.; Parsai, E. I.; Karpov, V. G.; Shvydka, Diana

    2015-09-01

    We have investigated the influence of electron irradiation on tin whisker growth. Sputtered tin samples exposed to electron beam of 6 MeV energy exhibited fast whisker growth, while control samples did not grow any whiskers. The statistics of e-beam induced whiskers was found to follow the log-normal distribution. The observed accelerated whisker growth is attributed to electrostatic effects due to charges trapped in an insulating substrate. These results offer promise for establishing whisker-related accelerated life testing protocols.

  16. Persistent ion beam induced conductivity in zinc oxide nanowires

    OpenAIRE

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

    2015-01-01

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

  17. Heavy Ion Beams Induce Survivin Expression in Human Hepatoma SMMC-7721 Cells More Effectively than X-rays

    Institute of Scientific and Technical Information of China (English)

    Li GONG; Xiaodong JIN; Qiang LI; Jiangtao LIU; Lizhe AN

    2007-01-01

    High linear energy transfer (LET) heavy ion radiation is more effective in inducing biological damage than low-LET X-rays or γ-rays. Heavy ion beam provides good dose localization (Bragg peak) in critical cancer tissue and gives higher relative biological effectiveness in cell killing across the dose peak, so high-LET heavy ion beam is superior to low-LET radiation in cancer treatment. Survivin, as a member of the inhibitor of apoptosis protein family, might help cancerous cells to overcome the G2/M apoptotic checkpoint and favor the aberrant progression of transformed cells through mitosis. Survivin expression in the human hepatoma SMMC-7721 cell line after exposure to low-LET X-ray and high-LET carbon ion irradiation was investigated in this study. Compared with X-ray irradiation, the carbon ion beam clearly caused G2/M arrest and promoted the expression of the survivin gene in a dose-dependent manner. Clonogenic survival assay showed that SMMC-7721 cells were more radiosensitive to the high-LET carbon ions than to the X-rays, and the radiosensitivity was promoted after treatment with specific survivin short interfering RNA. Differential survivin expression at both transcriptional and translational levels was found for SMMC-7721 cells following low- and high-LET irradiation. The overexpression of survivin in SMMC-7721 cells is probably an important reason why the cancerous cells have radioresistance to strong stimulus such as dense ionizing high-LET radiation. However, the direct killing effect on cancerous cells by high-LET radiation might be more significant than the apoptosis inhibition through the overexpression of survivin following heavy ion irradiation.

  18. Radiation-induced effects in the electron-beam irradiation of dietary flavonoids

    Science.gov (United States)

    Tamba, M.; Torreggiani, A.

    2004-09-01

    The harmful effects of oxidative processes in living organisms can be reduced by the dietary intake of flavonoids, a class of phenolic compounds ubiquitous in plants and widely found in a number of fruits, vegetables and beverages. Many fruits and vegetables are treated by irradiation to solve preservation problems and a radical-induced degradation of nutrients, including polyphenols, may occur. The free radical chemistry of two abundant flavonoids in food, catechin and quercetin, have been investigated by using pulse radiolysis technique. The central role of the phenoxyl-type radical and the strong influence of the state of protonation of the compounds on the pathway of formation and decay of the corresponding oxidized radicals has been evidenced from the spectral properties and chemical reactivity of the radicals derived from the attack of several oxidizing species ( ṡOH, N 3ṡ SO 4-ṡ).

  19. Beam-Induced Effects and Radiological Issues in High-Intensity High-Energy Fixed Target Experiments

    CERN Document Server

    Mokhov, N V; Drozhdin, A I; Pronskikh, V S; Reitzner, D; Tropin, I S; Vaziri, K

    2014-01-01

    The next generation of accelerators for Megawatt proton and heavy-ion beams moves us into a completely new domain of extreme specific energies of up to 0.1 MJ/g (Megajoule/gram) and specific power up to 1 TW/g (Terawatt/gram) in beam interactions with matter. This paper is focused on deleterious effects of controlled and uncontrolled impacts of high-intensity beams on components of beam-lines, target stations, beam absorbers, shielding and environment. Two new experiments at Fermilab are taken as an example. The Long-Baseline Neutrino Experiment (LBNE) will explore the interactions and transformations of the world's highest-intensity neutrino beam by sending it from Fermilab more than 1,000 kilometers through the Earth's mantle to a large liquid argon detector. The Mu2e experiment is devoted to studies of the conversion of a negative muon to electron in the field of a nucleus without emission of neutrinos.

  20. Orbital angular momentum induced beam shifts

    OpenAIRE

    Hermosa N.; Merano M.; Aiello A.; Woerdman J.P.

    2011-01-01

    We present experiments on Orbital Angular Momentum (OAM) induced beam shifts in optical reflection. Specifically, we observe the spatial Goos-H\\"anchen shift in which the beam is displaced parallel to the plane of incidence and the angular Imbert-Fedorov shift which is a transverse angular deviation from the geometric optics prediction. Experimental results agree well with our theoretical predictions. Both beam shifts increase with the OAM of the beam; we have measured these for OAM indices u...

  1. Effect of focused ion beam deposition induced contamination on the transport properties of nano devices

    International Nuclear Information System (INIS)

    Focused ion beam (FIB) deposition produces unwanted particle contamination beyond the deposition point. This is due to the FIB having a Gaussian distribution. This work investigates the spatial extent of this contamination and its influence on the electrical properties of nano-electronic devices. A correlation study is performed on carbon-nanotube (CNT) devices manufactured using FIB deposition. The devices are observed using transmission electron microscopy (TEM) and these images are correlated with device electrical characteristics. To discover how far Pt-nanoparticle contamination occurs along a CNT after FIB electrical contact deposition careful TEM inspections are performed. The results show FIB deposition efficiently improves electrical contact; however, the practice is accompanied by serious particle contamination near deposition points. These contaminants include metal particles and amorphous elements originating from precursor gases and residual water molecules in the vacuum chamber. Pt-contamination extends for approximately 2 μm from the point of FIB contact deposition. These contaminants cause current fluctuations and alter the transport characteristics of devices. It is recommended that nano-device fabrication occurs at a distance greater than 2 μm from the FIB deposition of an electrical contact. (paper)

  2. Effect of chromatic-dispersion-induced chirp on the temporal coherence properties of individual beams from spontaneous four-wave mixing

    International Nuclear Information System (INIS)

    Temporal coherence of individual signal or idler beam, determined by the spectral correlation property of photon pairs, is important for realizing quantum interference among independent sources. Based on spontaneous four-wave mixing in optical fibers, we study the effect of chirp on the temporal coherence property by introducing a different amount of chirp into either the pulsed pump or individual signal (idler) beam. The investigation shows that the pump chirp induces additional frequency correlation into photon pairs; the mutual spectral correlation of photon pairs and the coherence of individual beam can be characterized by measuring the intensity correlation function g(2) of the individual beam. To improve the coherence degree, the pump chirp should be minimized. Moreover, a Hong-Ou-Mandel-type two-photon interference experiment with the signal beams generated in two different fibers illustrates that the chirp of the individual signal (idler) beam does not change the temporal coherence degree, but affects the temporal mode matching. To achieve high visibility among multiple sources, apart from improving the coherence degree, mode matching should be optimized by managing the chirps of individual beams.

  3. Structural effects induced by 2.5 MeV proton beam on zeolite 4A: Positron annihilation and X-ray diffraction study

    International Nuclear Information System (INIS)

    Structural changes induced by 2.5 MeV proton beam in zeolite 4A were studied at fluences of 1.1016, 8.1016 and 2.1017 ion/cm2. Positron lifetime (LT) measurements were performed in vacuum after a heat treatment to remove the water from samples. X-ray diffraction method (XRD) was also applied to determine the changes in the crystallinity of zeolite. Gradual transformation of the crystalline structure to amorphous one can be observed in dependence of the implanted doses. Combination of LT and XRD provides a consistent view on structural effects induced by H+ beam in zeolite 4A. - Highlights: • Structural effects of zeolite 4A induced by the proton beam depend on the implanted doses. • The amorphization dose for zeolite 4A is approximately 1010 Gy. • The effects of radiation on zeolite could be different for cage structures. • Positron annihilation can become a effective method for studying irradiated zeolites

  4. Compensating tune spread induced by space charge in bunched beams

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, V.; Wang, G.

    2015-05-03

    The effects of space charge play a significant role in modern-day accelerators, frequently constraining the beam parameters attainable in an accelerator or in an accelerator chain. They also can limit the luminosity of hadron colliders operating either at low energies or with 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. Using an appropriate electron beam would compensate both the tune shift and the tune spread in the hadron beam in a coasting beam. But these methods cannot compensate space charge tune spread in a bunched hadron beam. In this paper we propose and evaluate a novel idea of using a co-propagating electron bunch with mismatched longitudinal velocity to compensate the space charge induced tune-shift and tune spread.

  5. Effects of oxygen on electron beam induced deposition of SiO2 using physisorbed and chemisorbed tetraethoxysilane

    Science.gov (United States)

    Bishop, James; Toth, Milos; Phillips, Matthew; Lobo, Charlene

    2012-11-01

    Electron beam induced deposition (EBID) is limited by low throughput and purity of as-grown material. Co-injection of O2 with the growth precursor is known to increase both the purity and deposition rate of materials such as SiO2 at room temperature. Here, we show that O2 inhibits rather than enhances EBID from tetraethoxysilane (TEOS) precursor at elevated temperatures. This behavior is attributed to surface site competition between chemisorbates at elevated temperature, and TEOS decomposition by atomic oxygen produced through electron dissociation of physisorbed O2 at room temperature.

  6. Effects of oxygen on electron beam induced deposition of SiO{sub 2} using physisorbed and chemisorbed tetraethoxysilane

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, James; Toth, Milos; Phillips, Matthew; Lobo, Charlene [School of Physics and Advanced Materials, University of Technology, Sydney, P.O. Box 123, Broadway, New South Wales 2007 (Australia)

    2012-11-19

    Electron beam induced deposition (EBID) is limited by low throughput and purity of as-grown material. Co-injection of O{sub 2} with the growth precursor is known to increase both the purity and deposition rate of materials such as SiO{sub 2} at room temperature. Here, we show that O{sub 2} inhibits rather than enhances EBID from tetraethoxysilane (TEOS) precursor at elevated temperatures. This behavior is attributed to surface site competition between chemisorbates at elevated temperature, and TEOS decomposition by atomic oxygen produced through electron dissociation of physisorbed O{sub 2} at room temperature.

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

    International Nuclear Information System (INIS)

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

  8. 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...

  9. 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.

  10. Beam-beam effect seen through forced vibration

    International Nuclear Information System (INIS)

    In electron accelerator, tune is measured by giving beam transverse forced vibration caused by RF frequency. It is well known that beam-beam parameter can be measured if beam-beam interaction exists. Generally, small value is chosen as the amplitude of forced vibration, and many researches were done in this case. In this report, we discuss effect of resonance caused by beam-beam interaction in case of amplitude of forced vibration being big. (author)

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

    International Nuclear Information System (INIS)

    Plasmid pGEM 3zf(+) was irradiated by nitrogen ion beam with energies between 20 and 100 keV and the fluence kept as 1 x 1012 ions/cm2. 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.)

  12. Beam induced RF cavity transient voltage

    International Nuclear Information System (INIS)

    We calculate the transient voltage induced in a radio frequency (RF) cavity by the injection of a relativistic bunched beam into a circular accelerator. A simplified model of the beam induced voltage, using a single tone current signal, is generated and compared with the voltage induced by a more realistic model of a point-like bunched beam. The high Q limit of the bunched beam model is shown to be related simply to the simplified model. Both models are shown to induce voltages at the resonant frequency ωr of the cavity and at an integer multiple of the bunch revolution frequency (i.e. the accelerating frequency for powered cavity operation) hω0. The presence of two nearby frequencies in the cavity leads to a modulation of the carrier wave exp(jhω0t). A special emphasis is placed in this paper on studying the modulation function. These models prove useful for computing the transient voltage induced in superconducting RF cavities, which was the motivation behind this research. The modulation of the transient cavity voltage discussed in this paper is the physical basis of the recently observed and explained new kind of longitudinal rigid dipole mode which differs from the conventional Robinson mode

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

    Science.gov (United States)

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

    2016-07-01

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

  14. Effects of porous carbon additives and induced fluorine on low dielectric constant polyimide synthesized with an e-beam

    International Nuclear Information System (INIS)

    We report the synthesis of a polyimide matrix with a low dielectric constant for application as an intercalation material between metal interconnections in electronic devices. Porous activated carbon was embedded in the polyimide to reduce the dielectric constant, and a thin film of the complex was obtained using the spin-coating and e-beam irradiation methods. The surface of the thin film was modified with fluorine functional groups to impart water resistance and reduce the dielectric constant further. The water resistance was significantly improved by the modification with hydrophobic fluorine groups. The dielectric constant was effectively decreased by porous activated carbon. The fluorine modification also resulted in a low dielectric constant on the polyimide surface by reducing the polar surface free energy. The dielectric constant of polyimide film decreased from 2.98 to 1.9 by effects of porous activated carbon additive and fluorine surface modification.

  15. Induced radioactivity of the IHEP proton synchrotron beam extraction equipment

    International Nuclear Information System (INIS)

    The measurement results of induced radioactivity of the beam extraction equipment during 1972-1978 are presented. All the values are given to the moment of the accelerator stop. The experimental data permits to predict further possible variations of the induced radioactivity levels of the equipment. Given are the measures required for reduction of the accelerator equipment irradiation, which are the following: 1) compensation of residual distortion of a closed beam orbit in the course of the induction system operation; 2) limitation of the intensity of drop on the internal targets up to the 11 protons per target level over a cycle; 3) putting into operation the program control system for the duration of a current pulse of a linear accelerator to minimize the beam residues at the 70 GeV energy during physical experiments; 4) construction of the system of beam interception and cutting-off to ensure effective energy suppression of uncontrolled beam residues and localization of their radiation effect; 5) extraction of a high-energy beam out of the accelerator during the experiments (e.g., into the neutrino channel for apparatus adjusting) instead of its dropping on the interceptor-target; 6) beam orbit controlling in the case of multiturn injection into the accelerator

  16. Effect of the Bethe surface description on the electronic excitations induced by energetic proton beams in liquid water and DNA

    Science.gov (United States)

    Abril, Isabel; Denton, Cristian D.; de Vera, Pablo; Kyriakou, Ioanna; Emfietzoglou, Dimitris; Garcia-Molina, Rafael

    2010-06-01

    The irradiation of biological systems by energetic ion beams has multiple applications in medical physics and space radiation health, such as hadrontherapy for cancer treatment or protection of astronauts against space radiation. Therefore, for a better control and understanding of the effects of radiation damage in living tissues, it is necessary to advance an accurate description of the energy loss from the ion beam to the target. In the present work we use the dielectric formalism to calculate the probability for an energetic proton to produce electronic excitations in two targets of high biological interest, namely, liquid water and DNA. Also, the mean energy of the electronic excitations in these targets is found as a function of the incident proton energy. The electronic response of the target, characterized by its energy-loss function (ELF), is described by several models that fit the available experimental optical data (at zero momentum transfer), but use different approaches to obtain the Bethe surface, that is, to extend the ELF to any energy and momentum transferred.

  17. 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...

  18. 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

    We have studied sulfuric acid aerosol nucleation in an atmospheric pressure reaction chamber using a 580 MeV electron beam to ionize the volume of the reaction chamber. We find a clear contribution from ion-induced nucleation and consider this to be the first unambiguous observation of the ion-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...

  19. Effect of solubility parameter of monomers on electron beam induced graft-polymerization onto plasticized poly(vinyl chloride) films

    International Nuclear Information System (INIS)

    Electron beam induced graft-polymerization by the mutual irradiation technique of monomers with different solubility parameters δ onto plasticized poly(vinyl chloride) (plas. PVC) films was investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of apparent graft and thickness of graft layers, and structure of the grafted films was elucidated from the degree of dyeing and electrostatic charged voltage for the grafted films. As δ of monomers increased, apparent graft decreased and thickness of the graft layer decreased. This suggests that mutual solubility of monomers and plas. PVC depended upon mutual solubility of monomers and the plasticizer. As δ of monomers increased, mutual solubility of monomers and the plasticizer decreased, amount of impregnation of monomers into plas. PVC films and thickness of the layer impregnated with monomers decreased. The degree of dyeing of the grafted films decreased with increasing δ of monomer, and the electrostatic charged voltage of the grafted films with larger δ monomers were higher than that of the control film. It is assumed that graft chains, which were consisted of monomers with large δ, showed low mutual solubility to the plasticizer and thus restricted the motion of the plasicizer to prevent migration into the graft layer. (author)

  20. Beam-induced tensor pressure tokamak equilibria

    International Nuclear Information System (INIS)

    D-shaped tensor pressure tokamak equilibria induced by neutral-beam injection are computed. The beam pressure components are evaluated from the moments of a distribution function that is a solution of the Fokker-Planck equation in which the pitch-angle scattering operator is ignored. The level-psub(perpendicular) contours undergo a significant shift away from the outer edge of the device with respect to the flux surfaces for perpendicular beam injection into broad-pressure-profile equilibria. The psub(parallel) contours undergo a somewhat smaller inward shift with respect to the flux surfaces for both parallel and perpendicular injection into broad-pressure-profile equilibria. For peaked-pressure-profile equilibria, the level pressure contours nearly co-incide with the flux surfaces. (author)

  1. Beam-beam effects under the influence of external noise

    OpenAIRE

    Ohmi, K.

    2014-01-01

    Fast external noise, which gives fluctuation into the beam orbit, is discussed in connection with beam-beam effects. Phase noise from crab cavities and detection devices (position monitor) and kicker noise from the bunch by bunch feedback system are the sources. Beam-beam collisions with fast orbit fluctuations with turn by turn or multi-turn correlations, cause emittance growth and luminosity degradation. We discuss the tolerance of the noise amplitude for LHC and HL-LHC.

  2. Relaxation of Blazar-induced Pair Beams in Cosmic Voids

    Science.gov (United States)

    Miniati, Francesco; Elyiv, Andrii

    2013-06-01

    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.

  3. 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.

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

    International Nuclear Information System (INIS)

    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.

  5. Protective effects of melatonin against 12C6+ beam irradiation-induced oxidative stress and DNA injury in the mouse brain

    Science.gov (United States)

    Wu, Z. H.; Zhang, H.; Wang, X. Y.; Yang, R.; Liu, B.; Liu, Y.; Zhao, W. P.; Feng, H. Y.; Xue, L. G.; Hao, J. F.; Niu, B. T.; Wang, Z. H.

    2012-01-01

    The purpose of this experiment was to estimate the protective effects of melatonin against radiation-induced brain damages in mice induced by heavy ion beams. Kun-Ming mice were randomly divided into five groups: normal control group, irradiation control group, and three different doses of melatonin (5, 10, and 20 mg/kg, i.p.) treated groups. Apart from the normal control group, the other four groups were exposed to whole-body 4.0 Gy carbon ion beam irradiation (approximately 0.5 Gy/min) after i.p. administration of normal saline or melatonin 1 h before irradiation. The oxidative redox status of brain tissue was assessed by measurement of malondiadehyde (MDA) levels, total superoxide dismutase (T-SOD), cytosolic superoxide dismutase (Cu/ZnSOD, SOD1) and mitochondrial superoxide dismutase (MnSOD, SOD2) activities at 8 h after irradiation. DNA damages were determined using the Comet assay and apoptosis and cell cycle distribution were detected by flow cytometric analyses. A dramatic dose-dependent decrease in MDA levels, tail moment, rates of tailing cells, and apoptosis, and a dose-dependent increase in T-SOD and SOD2 activities, in brain tissues in the melatonin-treated groups were detected compared with the irradiation only group. Furthermore, flow cytometric analysis demonstrated that the percentage of brain cells in the G0/G1 phase decreased significantly, while those in the S and G2/M stage increased dramatically, with mice pretreated with melatonin compared to the irradiation control group. These data indicate that melatonin has protective effects against irradiation-induced brain injury, and that its underlying protective mechanisms may relate to modulation of oxidative stress induced by heavy ionirradiation.

  6. Effects of implantation temperature and thermal annealing on the Ga{sup +} ion beam induced optical contrast formation in a-SiC:H

    Energy Technology Data Exchange (ETDEWEB)

    Tsvetkova, T., E-mail: tania_tsvetkova@yahoo.co.uk [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); University of Exeter, College of Engineering, Mathematics and Physical Sciences, Harrison Building, North Park Rd, Exeter EX4 4QF (United Kingdom); Wright, C.D. [University of Exeter, College of Engineering, Mathematics and Physical Sciences, Harrison Building, North Park Rd, Exeter EX4 4QF (United Kingdom); Kitova, S. [Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, 109 Acad. G. Bontchev St., 1113 Sofia (Bulgaria); Bischoff, L. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 51 01 19, 01314 Dresden (Germany); Zuk, J. [Institute of Physics, Maria Curie-Sklodovska University, Pl. M.Curie-Sklodovskiej 1, 20-031 Lublin (Poland)

    2013-07-15

    The effects of implantation temperature and post-implantation thermal annealing on the Ga{sup +} ion beam induced optical contrast formation in hydrogenated silicon–carbon alloy films have been studied. As a result of the implantation a well-expressed “darkening” effect (i.e. absorption edge shift to the longer-wavelength/lower-photon-energy region) has been registered. It is accompanied by a remarkable increase of the absorption coefficient up to 2 orders of magnitude in the measured photon energy range (1.5–3.1 eV). The optical contrast thus obtained (between implanted and unimplanted regions of the film material) has been made use of in the form of optical pattern formation by computer-operated Ga{sup +}-focused ion beam. Possible applications of this effect in the area of submicron lithography and high-density optical data storage have been suggested with regard to the most widely spread focused micro-beam systems based on Ga{sup +} liquid metal ion sources. The fact that Ga has a very low melting point (T{sub m} = 29.8 °C) and an unusual feature of volume contraction on melting are factors which favour Ga incorporation upon ion-implantation as dispersed clusters, or small nanoparticles. It has been previously noted that Ga precipitation into nanoparticles can vary dramatically (in terms of particle size) with Ga concentration and small changes in surface implant temperature, thus affecting the optical properties of the target. The precise role of implantation temperature effects, i.e. the target temperature during Ga{sup +} ion irradiation, on the optical contrast obtainable, has been therefore a key part of this study. Appropriate post-implantation annealing treatments were also studied, since these are expected to offer further benefits in reducing the required ion dose and enhancing contrast, thus increasing the cost-effectiveness of the bit-writing method.

  7. Electron-beam induced disorder effects in optimally doped Bi2Sr2CaCu2O8+x single crystal samples

    Science.gov (United States)

    Vobornik, I.; Berger, H.; Pavuna, D.; Margaritondo, G.; Forro, L.; Grioni, M.; Rullier-Albenque, F.; Onellion, M.; EPFL Collaboration; Laboratoire Des Solides Irradiés Collaboration

    2000-03-01

    We report on the effects of electron-beam induced disorder in optimally doped Bi2Sr2CaCu2O8+x single crystal samples, measured with angle-resolved photoemission. In the superconducting state, the disorder fills in the gap, without changing the binding energy or the width of the narrow coherent feature.[1] In the normal state, disorder leads to an anisotropic pseudogap in angle-resolved photoemission, with the largest pseudogap near the (0,p) point and no pseudogap in the direction.[2,3] We discuss implications of these data. 1. I. Vobornik et.al., Phys. Rev. Lett. 82 , 3128 (1999). 2. I. Vobornik, Ph.D. thesis, EPFL, Lausanne, Switzerland, October, 1999. 3. I. Vobornik et.al., unpublished.

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

    Institute of Scientific and Technical Information of China (English)

    Huan FANG; Zhen JIAO

    2012-01-01

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

  9. Self-organization of coupling optical waveguides by the "pulling water" effect of write beam reflections in photo-induced refractive-index increase media

    Science.gov (United States)

    Yoshimura, Tetsuzo; Kaburagi, Hiroshi

    2009-02-01

    To reduce efforts for optical assembly, we developed the reflective self-organized lightwave network (R-SOLNET). In R-SOLNET, optical devices with wavelength filters on their core facets are distributed in photo-induced refractive-index increase (PRI) media such as photo-polymers. Write beams from some devices and reflected write beams from the wavelength filters of the other devices overlap. In the overlap regions, the refractive index increases, pulling the write beams to the wavelength filter locations (the "pulling water" effect). By self-focusing, self-aligned optical waveguide networks are formed between the optical devices. Simulations based on the finite difference time domain method revealed that self-aligned optical waveguides of R-SOLNET are formed between cores with 2-μm and 0.5-μm widths including Y-branching waveguides. Experiments demonstrated that R-SOLNET is formed between an optical fiber and a micro-mirror placed with ~800-μm gap. For angular misalignment of 3o between the optical fiber and the micro-mirror, a bow-shaped R-SOLNET was observed. For lateral misalignment of 30 μm, an S-shaped R-SOLNET was observed. These results suggest that by placing reflective elements in PRI media, optical waveguides can be lead to the elements to form R-SOLNET. This enables self-aligned optical couplings for optoelectronic boards, intra-chip optical circuits, VCSELs/PDs, optical switches, and so on.

  10. 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.

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

    International Nuclear Information System (INIS)

    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

  12. Beaming Effect in Fermi Blazars

    OpenAIRE

    Fan, J.H.; Yang, J. H.; Zhang, J Y; Hua, T. X.; Liu, Y.; Qin, Y. P.; Huang, Y.

    2012-01-01

    The \\gamma-ray loud blazars (flat spectrum radio quasars--FSRQs and BL Lacertae objects-BLs) are very bright in the \\gamma-ray bands, which is perhaps associated with a beaming effect. Therefore, one can expect that the \\gamma-ray luminosity is correlated with the beaming factor. In this paper, we investigated the relation between the radio Doppler factors and the gamma-ray luminosities. Our analysis suggests that the \\gamma-ray luminosity be strongly correlated with the factor of \\delta_R fo...

  13. Electromagnetic forces on plasmonic nanoparticles induced by fast electron beams

    International Nuclear Information System (INIS)

    The total momentum transfer from fast electron beams, like those employed in scanning transmission electron microscopy (STEM), to plasmonic nanoparticles is calculated. The momentum transfer is obtained by integrating the electromagnetic forces acting on the particles over time. Numerical results for single and dimer metallic nanoparticles are presented, for sizes ranging between 2 and 80 nm. We analyze the momentum transfer in the case of metallic dimers where the different relevant parameters such as particle size, interparticle distance, and electron beam impact parameter are modified. It is shown that depending on the specific values of the parameters, the total momentum transfer yields a force that can be either attractive or repulsive. The time-average forces calculated for electron beams commonly employed in STEM are on the order of piconewtons, comparable in magnitude to optical forces and are thus capable of producing movement in the nanoparticles. This effect can be exploited in mechanical control of nanoparticle induced motion.

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

    Science.gov (United States)

    An, W.; Zhou, M.; Vafaei-Najafabadi, N.; Marsh, K. A.; Clayton, C. E.; Joshi, C.; Mori, W. B.; Lu, W.; Adli, E.; Corde, S.; Litos, M.; Li, S.; Gessner, S.; Frederico, J.; Hogan, M. J.; Walz, D.; England, J.; Delahaye, J. P.; Muggli, P.

    2013-10-01

    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.

  15. Light emission from particle beam induced plasma - An overview

    CERN Document Server

    Ulrich, A

    2015-01-01

    Experiments to study the light emission from plasma produced by particle beams are presented. Fundamental aspects in comparison with discharge plasma formation are discussed. It is shown that the formation of excimer molecules is an important process. This paper summarizes various studies of particle beam induced light emission and presents first results of a direct comparison of light emission induced by electron- and ion beam excitation. Both high energy heavy ion beam and low energy electron beam experiments are described and an overview over applications in the form of light sources, lasers, and ionization devices is given.

  16. Beam induced damage - what is a safe beam?

    CERN Document Server

    Kain, V; Brugger, M; Sapinski, M

    2009-01-01

    The knowledge of damage levels is vital to define protection schemes, beam loss monitor thresholds, safe beam limits for setting up the machines, etc. This talk will try to revisit our present knowledge and assumptions on damage levels in the LHC in terms of lost beam intensity, beam momentum and emittance. It is clear that with the LHC’s unprecedented energy reach, benchmark tests to cross-check energy deposition simulations for all possible energies before LHC start-up have not been possible. Also, the definition of when equipment is damaged is not always straight forward. In view of the obvious limitations to our knowledge of damage levels, operational commissioning and LHC running strategies will be re-discussed, open questions will be highlighted and proposals will be presented where possible.

  17. Electron-beam-induced conduction in polyethylene

    International Nuclear Information System (INIS)

    The electrical conduction in polyethylene induced by the irradiation of the short-pulsed-electron-beam (100 nsec time width) consists of the fast and the slow components. The former is attributed to the carrier transport in the crystalline part and the latter to that in the amorphous part. Logarithmic plot (Scher-Montroll plot) of the slow part of the induced current vs. time gives a knee at time T sub(r), which is thought to be the transit time of the carrier front between electrodes. Simple calculation by the formula μ = L/T sub(r) E gives the apparent slow carrier mobility μ of 5.6 x 10-7 cm2/V.sec and 3.2 x 10-7 cm2/V.sec for the electron and the hole respectively at 343 K under the field E of 1.2 MV/cm for the sample thickness L of 12 μm. These apparent slow carrier mobilities are dependent on both the thickness and the field strength. These behavior are discussed in terms of Scher-Montroll theory on the transport in amorphous substances. The activation energy of the mobility is in good agreement with the apparent trap depth obtained from the TSC measurement. (author)

  18. 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)

  19. Aerosol nucleation induced by a high energy particle beam

    DEFF Research Database (Denmark)

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

    The effect of ions in aerosol nucleation is a subject where much remains to be discovered. That ions can enhance nucleation has been shown by theory, observations, and experiments. However, the exact mechanism still remains to be determined. One question is if the nature of the ionization affects...... the nucleation. This is an essential question since many experiments have been performed using radioactive sources that ionize differently than the cosmic rays which are responsible for the majority of atmospheric ionization. Here we report on an experimental study of sulphuric acid aerosol nucleation under near...... atmospheric conditions using a 580 MeV electron beam to ionize the volume of the reaction chamber. We find a clear and significant contribution from ion induced nucleation and consider this to be an unambiguous observation of the ion-effect on aerosol nucleation using a particle beam under conditions not far...

  20. A critical literature review of focused electron beam induced deposition

    Science.gov (United States)

    van Dorp, W. F.; Hagen, C. W.

    2008-10-01

    An extensive review is given of the results from literature on electron beam induced deposition. Electron beam induced deposition is a complex process, where many and often mutually dependent factors are involved. The process has been studied by many over many years in many different experimental setups, so it is not surprising that there is a great variety of experimental results. To come to a better understanding of the process, it is important to see to which extent the experimental results are consistent with each other and with the existing model. All results from literature were categorized by sorting the data according to the specific parameter that was varied (current density, acceleration voltage, scan patterns, etc.). Each of these parameters can have an effect on the final deposit properties, such as the physical dimensions, the composition, the morphology, or the conductivity. For each parameter-property combination, the available data are discussed and (as far as possible) interpreted. By combining models for electron scattering in a solid, two different growth regimes, and electron beam induced heating, the majority of the experimental results were explained qualitatively. This indicates that the physical processes are well understood, although quantitatively speaking the models can still be improved. The review makes clear that several major issues remain. One issue encountered when interpreting results from literature is the lack of data. Often, important parameters (such as the local precursor pressure) are not reported, which can complicate interpretation of the results. Another issue is the fact that the cross section for electron induced dissociation is unknown. In a number of cases, a correlation between the vertical growth rate and the secondary electron yield was found, which suggests that the secondary electrons dominate the dissociation rather than the primary electrons. Conclusive evidence for this hypothesis has not been found. Finally

  1. Electron beam induced modification of grafted polyamides

    International Nuclear Information System (INIS)

    It is well known that irradiation, when applied on its own or in combination with other physical and chemical treatments, can manifest in radiation damage to materials. Radiation processing technology focuses upon producing favourable modification of materials through use of relatively high dose and dose rates. Current interest is in modifying the thermal and electrical properties of textured polymers in an effort to improve safety and wear comfort of clothing. No less important is the production of textiles which are safe to use, both in homes and offices. Present investigations provide additional data in support of findings which show that polyamides, a particular class of textured polymer, are amenable to radiation processing. Accelerated electron beam irradiation of sheets of polyamide fibre results in induced grafting of acrylic and methacrylic acids. The degree of grafting is critically dependent upon irradiation dose and the extent of monomers dilution. Of particular importance is the high correlation which is found between degree of grafting and a decrease in the softening rate of the modified polyamide. A systematic modification of electrical conductivity is also observed. (author)

  2. Electron-beam-induced conduction in Si02 thin films

    International Nuclear Information System (INIS)

    Results are presented of an investigation into electron-beam-induced conduction (EBIC) in films of Si02 thermally grown on a silicon substrate. A strong dependence on the polarity of the voltage applied during irradiation is observed. For negative applied voltages which correspond to an electron flow to the silicon substrate, the EBIC gain curves follow the the predictions of a recent theory. For positive voltages an electron emission analogous to internal photoemission occurs from the silicon substrate as soon as the beam begins to penetrate into the silicon. In some samples this emission current was sufficiently low that an EBIC gain curve due to hole flow to the substrate was observed. However, only by taking into account the dispersive nature of hole transport could agreement between experiment and the theory be obtained. Finally, effects due to previous irradiation are observed and interpreted as the generation of traps and/or a space charge build-up during the initial irradiation. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-15

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

  4. Sharpness changes of gaussian beams induced by spherically aberrated lenses

    Science.gov (United States)

    Piquero, G.; Mejías, P. M.; Martínez-Herrero, R.

    1994-04-01

    Sharpness changes of the spatial profile of a gaussian beam induced by spherically aberrated lenses are investigated in terms of the so-called kurtosis parameter. It is shown both theoretically and experimentally that, after a single aberrated lens, it is possible to get flatter and sharper beam intensity distributions than the input gaussian beam depending on the plane where the field is observed. Agreement between analytical and experimental results is discussed.

  5. Pile-up reduction by detector-induced beam suppression

    International Nuclear Information System (INIS)

    The technique of detector-induced beam suppression using a beam deflector and a high power pulse generator has been explored. The γ spectra of the 98Mo(α,xn) reactions are presented with and without beam suppression and it is seen that with the pile-up reduction system working, there is a considerable increase in the count rate in the 98Rn 653 keV peak, with almost the same background. (C.F.)

  6. Mechanistic studies of electron beam induced organic reactions for electron beam resist materials

    International Nuclear Information System (INIS)

    Triphenylsulfonium methanesulfonate in the solid state was irradiated with an electron beam and the radiolytic products were characterized spectroscopically and chromatographically. The electron beam irradiation of the salt offered a new benzene-substituted sulfonium salt, together with methanesulfonic acids, diphenyl sulfides, and 2-, 3- and 4-phenylthiobyphenyls known as photoproducts of triphenylsulfonium salts. The formation of the salt appears to be due to the nature of electron beam induced reactions. (author)

  7. In vitro studies to evaluate the protective effects of Cassia fistula on electron beam radiation induced damages in human dermal fibroblasts

    International Nuclear Information System (INIS)

    Radiation is increasingly used for medical and occupational purposes and is an established weapon in the diagnosis and the therapy of cancer. Cassia fistula, a member of the Leguminosae family, it is used as a traditional medicine specially to treat the skin diseases. The main objective of the study was to evaluate the changes induced by different doses of Electron Beam radiation on Human Dermal Fibroblasts (HDF) and protective effects of Cassia fistula on the same. Aqueous, methanolic and ethonolic extracts of Cassia fistula were prepared. In vitro 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 study the antioxidant properties. HDF cells were standardized and treated with the Cassia fistula MTT assay was performed. Cells were irradiated and MTT, Micronucleus (MN) assays were performed then compared with control and non-irradiated cells. Cells were treated with Cassia fistula and irradiated; MTT and MN were performed. On comparison with the standard Ascorbic acid, ethanolic extract of Cassia fistula was showing 90% activity. The ethanolic extract of Cassia fistula is having high EC50 value. On comparison to the standard the alcoholic extracts of Cassia fistula has shown a higher FRAP value. Aqueous extract of Cassia fistula has minimum Nitric oxide scavenging property compared to alcoholic extracts. Methanolic and ethanolic extracts of Cassia fistula has shown 38-40% of Superoxide Radical Scavenging property in 500 μg/mL concentration. Also ethanolic and methanolic extracts of Cassia fistula has remarkable antioxidant property. Hence these concentrations were selected for further studies. Human Dermal Fibroblast cells were treated with the 500 μg/ mL of alcoholic Cassia fistula extracts which showed a protection against irradiated groups. (author)

  8. 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...

  9. Helium ion beam induced growth of hammerhead AFM probes

    NARCIS (Netherlands)

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

    2015-01-01

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

  10. Helium ion beam induced growth of hammerhead AFM probes

    NARCIS (Netherlands)

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

    2015-01-01

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

  11. Vacuum ultraviolet laser induced fluorescence on a Si atomic beam

    Science.gov (United States)

    O'Brian, T. R.; Lawler, J. E.

    1991-01-01

    A broadly applicable vacuum ultraviolet experiment is described for measuring radiative lifetimes of neutral and singly-ionized atoms in a beam environment to 5-percent accuracy using laser induced fluorescence. First results for neutral Si are reported.

  12. Ion beam induced luminescence characterisation of CVD diamond films

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  13. 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.

  14. Ion beam induced alignment of semiconductor nanowires

    International Nuclear Information System (INIS)

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

  15. Beam induced vacuum measurement error in BEPC II

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    When the beam in BEPCII storage ring aborts suddenly, the measured pressure of cold cathode gauges and ion pumps will drop suddenly and decrease to the base pressure gradually. This shows that there is a beam induced positive error in the pressure measurement during beam operation. The error is the difference between measured and real pressures. Right after the beam aborts, the error will disappear immediately and the measured pressure will then be equal to real pressure. For one gauge, we can fit a non-linear pressure-time curve with its measured pressure data 20 seconds after a sudden beam abortion. From this negative exponential decay pumping-down curve, real pressure at the time when the beam starts aborting is extrapolated. With the data of several sudden beam abortions we have got the errors of that gauge in different beam currents and found that the error is directly proportional to the beam current, as expected. And a linear data-fitting gives the proportion coefficient of the equation, which we derived to evaluate the real pressure all the time when the beam with varied currents is on.

  16. Relativistic-electron-beam-induced fusion

    International Nuclear Information System (INIS)

    The interaction of a focussed relativistic electron beam (REB) with a solid target has been investigated. The beam performance of the REB generator ''REIDEN III'' is 500 kV, 80 kA at a focal spot of 1.5 mm diameter, which gives 2X1012Wcm-2. High-temperature dense plasmas are produced at the focal point on the solid target. It expands radially along the target surface. The measured electron temperature (1-2 keV) and the ion energy (approximately 2 keV) endorse the existence of enhanced REB absorption in a dense plasma. The neutrons observed (approximately 109/shot, 2.45 MeV) in the case of a CD2 target are of thermonuclear origin and compatible with the plasma temperature. On the assumption that the electron beam of radius r is stopped at a length Λ and deposits its energy, the energy balance equation is approximately given by πr2Λn1kT=IVtau. On inserting beam current I, voltage V, pulse time tau and density n1, the energy deposition distance Λ can be estimated. For a fusion temperature of 1 keV, the distance Λ must be two orders of magnitude shorter than the simple classical stopping length, which seems to be due to non-linear coupling. A pellet implosion experiment of a multi-structure target has been performed. (author)

  17. Long range beam-beam interaction and the effect on the beam and luminosity lifetimes

    CERN Document Server

    Crouch, Matthew; Barranco Garcia, Javier; Banfi, Danilo; Buffat, Xavier; Tambasco, Claudia; Alexahin, Yuri; Bruce, Roderik; Giachino, Rossano; Pojer, Mirko; Salvachua Ferrando, Belen Maria; Solfaroli Camillocci, Matteo; Trad, Georges; CERN. Geneva. ATS Department

    2016-01-01

    Identifying the minimum crossing angle achievable in the LHC is a key parameter to identify the collider luminosity reach. In this note, we summarise the observations collected during a dedicated experiment performed in 2015, where the strength of the long range beam-beam interaction is varied by reducing the crossing angle at IP1 and IP5. The crossing angle and the impact of the long range beam-beam interaction is analysed with respect to the beam and luminosity lifetimes. The effect of reducing Landau octupoles initially operating at 476 [A] and high chromaticity values (15 units) are also shown. The minimum crossing angle achievable with collisions is identified, together with the impact on beam and luminosity lifetimes

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

    International Nuclear Information System (INIS)

    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.

  19. Two-dimensional streaming flows induced by resonating, thin beams.

    Science.gov (United States)

    Açikalin, Tolga; Raman, Arvind; Garimella, Suresh V

    2003-10-01

    Miniaturized resonating slender beams are finding increased applications as fluidic actuators for portable electronics cooling. Piezoelectric and ultrasonic "fans" drive a flexural mode of the beam into resonance thus inducing a streaming flow, which can be used to cool microelectronic components. This paper presents analytical, computational, and experimental investigations of the incompressible two-dimensional streaming flows induced by resonating thin beams. Closed-form analytical streaming solutions are presented first for an infinite beam. These are used to motivate a computational scheme to predict the streaming flows from a baffled piezoelectric fan. Experiments are conducted to visualize the asymmetric streaming flows from a baffled piezoelectric fan and the experimental results are found to be in close agreement with the predicted results. The findings are expected to be of relevance in the optimal design and positioning of these solid-state devices in cooling applications. PMID:14587580

  20. 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.

  1. Superconducting nanowires by electron-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Shamashis, E-mail: shamashis.sengupta@u-psud.fr [CSNSM, Univ. Paris-Sud, IN2P3, UMR 8609, F-91405 Orsay Cedex (France); LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Li, Chuan; Guéron, S.; Bouchiat, H. [LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Baumier, Cedric; Fortuna, F. [CSNSM, Univ. Paris-Sud, IN2P3, UMR 8609, F-91405 Orsay Cedex (France); Kasumov, Alik [LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Institute of Microelectronics Technology and High Purity Materials, RAS, ac. Ossipyan, 6, Chernogolovka, Moscow Region 142432 (Russian Federation)

    2015-01-26

    Superconducting nanowires can be fabricated by decomposition of an organometallic gas using a focused beam of Ga ions. However, physical damage and unintentional doping often result from the exposure to the ion beam, motivating the search for a means to achieve similar structures with a beam of electrons instead of ions. This has so far remained an experimental challenge. We report the fabrication of superconducting tungsten nanowires by electron-beam-induced-deposition, with critical temperature of 2.0 K and critical magnetic field of 3.7 T, and compare them with superconducting wires made with ions. This work is an important development for the template-free realization of nanoscale superconducting devices, without the requirement of an ion beam column.

  2. Superconducting nanowires by electron-beam-induced deposition

    International Nuclear Information System (INIS)

    Superconducting nanowires can be fabricated by decomposition of an organometallic gas using a focused beam of Ga ions. However, physical damage and unintentional doping often result from the exposure to the ion beam, motivating the search for a means to achieve similar structures with a beam of electrons instead of ions. This has so far remained an experimental challenge. We report the fabrication of superconducting tungsten nanowires by electron-beam-induced-deposition, with critical temperature of 2.0 K and critical magnetic field of 3.7 T, and compare them with superconducting wires made with ions. This work is an important development for the template-free realization of nanoscale superconducting devices, without the requirement of an ion beam column

  3. Relaxation of Blazar Induced Pair Beams in Cosmic Voids

    OpenAIRE

    Miniati, Francesco; Elyiv, Andrii

    2012-01-01

    The stability properties of a low density ultra relativistic pair beam produced in the intergalactic medium 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 affect considerably the thermal history of the intergalactic medium and structure formation. We use a Monte Carlo method to quantify the properties of the blazar induced electromagnetic...

  4. Optical beam steering based on electromagnetically induced transparency

    International Nuclear Information System (INIS)

    We propose a scheme that provides all-optically-controlled steering of light beam. The system is based on steep dispersion of a coherently driven medium. Using the eikonal equation, we study the steering angle, the spread of the optical beam, and the limits set by residual absorption of the medium under conditions of electromagnetically induced transparency. Implementation of another scheme for ultrashort pulses is also discussed

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

    OpenAIRE

    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 structures after 2013, as described by the International Technology Roadmap for Semiconductors (ITRS), or can be used for rapid prototyping in research applications. The key point is to combine the throughp...

  6. Effects, causing intensification of synchrotron radiaiton beams

    International Nuclear Information System (INIS)

    Possibility of intensification of synchrotron radiation beams in optical and ultraviolet spectrum range by shift of generation range of the output synchrotron radiation beams from circle sections of electron orbit to the magnetic field of gaps, separating sections of the accelerator electromagnets is discussed. The degree of manifestation of the considered effects in synchrotrons for 0.6 and 7.5 GeV energy is evaluated. The results of their experimental investigati.on in the optical beam of the 0.6 GeV synchrotron radiation are given. The results obtained show that beam intensity in the gap centre between the magnet sections increases 3.2 times. The structure of beam intensity distribution improves simultaneously and vertical direction of radiation increases approximately 2 times. A conclusion is made on applicability of the described method for beam intensification of synchrotron radiation

  7. 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.)

  8. Beam-induced backgrounds in detectors at the ILC

    International Nuclear Information System (INIS)

    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 1034 cm-2s-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.)

  9. Are laser-induced beams spin polarized?

    Energy Technology Data Exchange (ETDEWEB)

    Buescher, Markus; Lehrach, Andreas; Raab, Natascha [Institut fuer Kernphysik (IKP), Juelich Center for Hadron Physics (JCHP), Forschungszentrum Juelich (Germany); Engin, Ilhan; Hessan, Mohammad Aziz [RWTH Aachen (Germany); Institut fuer Kernphysik (IKP), Juelich Center for Hadron Physics (JCHP), Forschungszentrum Juelich (Germany); Gibbon, Paul; Karmakar, Anupam [Juelich Supercomputing Center (JSC), Forschungszentrum Juelich (Germany); Toncian, Monika; Toncian, Toma; Willi, Oswald [Institut fuer Laser-Plasma Physik (ILPP), Heinrich Heine Universitaet, Duesseldorf (Germany)

    2011-07-01

    The physics of laser-plasma interactions has undergone dramatic developments in recent years, both experimentally and in the theoretical understanding of high-brightness light and particle sources. However, it is a yet untouched issue whether the laser-generated particle beams are or can be spin-polarized and, thus, whether laser-based polarized sources are conceivable. A first measurement of the degree of polarization of laser-accelerated protons have recently been carried out at the Duesseldorf Arcturus Laser Facility where proton beams of typically 3 MeV were produced in foil targets. The results have been analysed with the help of particle-in-cell simulations to follow the generation of static magnetic field gradients ({proportional_to}100s of Megagauss per micron) in thin foil targets. As a next step, measurements with unpolarized H{sub 2} (for proton acceleration) and {sup 3}He gas (for {sup 3}He ions) are planned and, finally, pre-polarized {sup 3}He will be used.

  10. High-power, electron beam-induced switching in diamond

    International Nuclear Information System (INIS)

    The authors are developing a high-voltage, high-average-power, electron beam-controlled diamond switch that could significantly impact high power solid-state electronics in industrial and defense applications. An electron beam-controlled, thin film diamond could switch, with high efficiency, well over 100 kW average power at MHz frequencies greater than 5kV. This performance is due to the excellent thermal and electronic properties of diamond, the high efficiency achieved with electron beam control, and the demonstrated effectiveness of microchannel cooling. The authors' electron beam penetration-depth measurements agree with their Monte Carlo calculations. They have not observed electron beam damage in diamond for beam energies up to 150 keV. This report describes their experimental and calculational results and research objectives

  11. MLC mediated beam hardening effects in IMRT

    International Nuclear Information System (INIS)

    Purpose: Beam hardening effects due to photons passing through the multi-leaf collimator (MLC) frequently exist in Intensity Modulated Radiotherapy (IMRT) fields. A fast online dose transmission verification system, MBMC (Measurement Based Monte Carlo), can verify IMRT delivery by using a fluence efficiency map to replace MLC geometry and movement simulation. This system, however, ignores beam hardening effects, and assumes that dose disturbances through the MLC are not significant for IMRT fields. This assumption has to be justified before it can be applied in the clinic. Methods: In this study, we simulated several field sizes (0.5 × 0.5, 1 × 1, 3 × 3, 5 × 5, and 10 × 10 cm2) to evaluate the dose influence of beam hardening effects under clinical conditions. In addition, a LATCH technique was used during simulation processes, which can record each particle interaction with specific gantry components, to distinguish between dose contribution from the total beam and MLC mediated beam. Results: The MLC indeed caused significant beam hardening effects, but the dose contribution fraction from the MLC was noticeable only for field sizes less than 1 × 1 cm2. Furthermore, in mixed fields containing both the total beam and MLC mediated beam, the maximum dose deviation due to the presence of the MLC is small even for the 0.5 × 0.5 cm2 field size (∼2%). Conclusions: The MLC causes noticeable beam hardening effects, but this effect results in only slight dose differences that are only noticeable for small field sizes in IMRT delivery. The use of a fluence efficiency map was feasible in our MBMC system.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-12

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

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

    International Nuclear Information System (INIS)

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

  14. Induced base transistor fabricated by molecular beam epitaxy

    Science.gov (United States)

    Chang, C.-Y.; Liu, W. C.; Jame, M. S.; Wang, Y. H.; Luryi, S.

    1986-09-01

    A novel three-terminal hot-electron device, the induced base transistor (IBT), has been fabricated by molecular beam epitaxy. Two-dimensional electron gas induced by the applied collector field in an undoped GaAs quantum well is used as the base of the IBT. The common-base current gain alpha has been achieved as high as 0.96 under a collector bias of 2.5 V and an emitter current of 3 mA.

  15. Ion beam induced fluorescence imaging in biological systems

    Science.gov (United States)

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

    2015-04-01

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

  16. Biological Effects on Fruit Fly by N+ ion Beam Implantation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mutation induced by low energy ion beam implantation has beenapplied widely both in plants and microbes. However, due to the vacuum limitation, such ion implantation into animals was never studied except for silkworm. In this study, Pupae of fruit fly were irradiated with different dosage N+ ions at energy 20 KeV to study the biological effect of ion beam on animal. The results showed a saddle-like curve exists between incubate rate and dosage. Damage of pupae by ion beam implantation was observed using scanning electron microscope. Some individuals with incomplete wing were obtained after implantation but no similar character was observed in their offspring. Furthermore, about 5.47% mutants with wide variation appeared in M1 generation. Therefore, ion beam implantation could be widely used for mutation breeding.

  17. Nonlinear propagation of a spatially incoherent laser beam: self-induced smoothing and reduction of scattering instabilities

    International Nuclear Information System (INIS)

    It is shown that plasma-induced angular spreading and spectral broadening of a spatially incoherent laser beam correspond to increased spatial and temporal incoherence of the laser light. The spatial incoherence is characterized by an effective beam f-number, decreasing in space along the direction of light propagation. Plasma-induced beam smoothing can influence laser-plasma interaction physics. In particular, decreasing the correlation time of the propagating laser light may dramatically reduce the levels of backward stimulated Brillouin and Raman scattering inside the plasma. Also, the decrease of the laser beam effective f-number reduces the reflectivity of backward stimulated Brillouin scattering. (authors)

  18. Simulating transient effects of pulsed beams on beam intercepting devices

    International Nuclear Information System (INIS)

    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 order to achieve their best potential. As a consequence of their separate development histories, their combination requires a large amount of work - at the physics limits of their application as well as at the frontier of computing technology. The current work did not touch all different points needed for a full integration, but it is a first step towards their coupling within a feasible time frame. For the simulation of metallic targets irradiated with highly energetic uranium ions different material models have been combined and one parameter describing the damage of the material was varied. In the case of two copper targets, this procedure led to a qualitative agreement between simulations and experimental results. (author)

  19. 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.

  20. Electron-beam induced synthesis of nanostructures: a review

    Science.gov (United States)

    Gonzalez-Martinez, I. G.; Bachmatiuk, A.; Bezugly, V.; Kunstmann, J.; Gemming, T.; Liu, Z.; Cuniberti, G.; Rümmeli, M. H.

    2016-06-01

    As the success of nanostructures grows in modern society so does the importance of our ability to control their synthesis in precise manners, often with atomic precision as this can directly affect the final properties of the nanostructures. Hence it is crucial to have both deep insight, ideally with real-time temporal resolution, and precise control during the fabrication of nanomaterials. Transmission electron microscopy offers these attributes potentially providing atomic resolution with near real time temporal resolution. In addition, one can fabricate nanostructures in situ in a TEM. This can be achieved with the use of environmental electron microscopes and/or specialized specimen holders. A rather simpler and rapidly growing approach is to take advantage of the imaging electron beam as a tool for in situ reactions. This is possible because there is a wealth of electron specimen interactions, which, when implemented under controlled conditions, enable different approaches to fabricate nanostructures. Moreover, when using the electron beam to drive reactions no specialized specimen holders or peripheral equipment is required. This review is dedicated to explore the body of work available on electron-beam induced synthesis techniques with in situ capabilities. Particular emphasis is placed on the electron beam-induced synthesis of nanostructures conducted inside a TEM, viz. the e-beam is the sole (or primary) agent triggering and driving the synthesis process.

  1. A comparative study on low-energy ion beam and neutralized beam modifications of naked DNA and biological effect on mutation

    Energy Technology Data Exchange (ETDEWEB)

    Sarapirom, S.; Thongkumkoon, P.; Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Anuntalabhochai, S. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2012-02-01

    DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ion beam biotechnology and ion beam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ion beam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ion beam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli (E. coli) for mutation analysis indicated that the charged ion beam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ion beam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

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

    Indian Academy of Sciences (India)

    N N Ghosh; G R Palmese

    2005-10-01

    Electron-beam (e-beam) induced polymerization of epoxy resins proceeds via cationic mechanism in presence of suitable photoinitiator. Despite good thermal properties and significant processing advantages, epoxy-based composites manufactured using e-beam curing suffer from low compressive strength, poor interlaminar shear strength, and low fracture toughness. A detailed understanding of the reaction mechanism involving e-beam induced polymerization is required to properly address the shortcomings associated with ebeam curable resin systems. This work investigated the effect of hydroxyl containing materials on the reaction mechanism of e-beam induced cationic polymerization of phenyl glycidyl ether (PGE). The alcohols were found to play important roles in polymerization. Compared to hydroxyl group of aliphatic alcohol, phenolic hydroxyl group is significantly less reactive with the oxonium active centre, generated during e-beam induced polymerization of epoxy resin system.

  3. 高能重离子在聚合物中的辐照效应研究%Radiation effects in polymers induced by high energy heavy ion beams

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhiyong; LIU Qi; SUN Youmei; JIN Yunfan

    2005-01-01

    Ion irradiation of polymers can induce irreversible changes in their macroscopic properties such as electrical and optical properties and the surface-related mechanical properties. Electronic excitation, ionization, chains scission, cross-links and mass losses are accepted as the fundamental events that give rise to the observed macroscopic changes. Detailed and systematic study of radiation induced effects in polymers enriches not only the knowledge of ion-material interactions but also supplies new bases for polymeric materials synthesis through ion-beam technologies. Previous work has concentrated mainly on effects induced by low-ionization particles such as γ-rays and electrons. Since 1980,s the application of high energy heavy ion accelerators enables the use of high energy heavy ion as an irradiation source, and many new and exciting effects and phenomena have been revealed.Energetic heavy ions in matter lose energy mainly through electronic excitation and ionization. Compared to low-ionization particles, high energy heavy ion possesses higher LET(linear energy transfer) values which can reach several to several tens keV/nm. As most of the primary ionizations and excitations occur close to the ion trajectory in a core of a few nanometers in diameter, a continuous damaged zone along the ion path can be induced,in which all bonds inside the zone can be destroyed due to the high rate energy deposition. Studies on this particularity of high energy heavy ion irradiation and its effects in materials will cause great influence on industry as well as on our daily life.The previous work has revealed the great difference in the effects induced by high energy heavy ions compared to the other particles. It has been shown that under irradiation with lower LET particles gas release depends on molecular structure and material composition, whereas under irradiation with high LET particles, such as high energy heavy ions, it is not the case. Some materials that undergo

  4. Beam loss and radiation effects in the SSC lattice elements

    International Nuclear Information System (INIS)

    The Superconducting Super Collider (SSC) is designed to be an advanced machine with relatively low beam loss-induced radiation levels. However, a fraction of the beam lost in the lattice due to pp-collisions at the interaction points, beam-gas scattering, bearn-halo scraping, various instabilities and errors will result in the irradiation of conventional and superconducting components of the accelerator and experimental apparatus. The level of the beam loss and its distribution along the machine structure has impact on all of the three crucial radiation effects at the SSC: quenching of the superconducting magnets, survivability of the accelerator and detectors components in the near-beam regions, and influence to the environment. This paper, based on the full-scale Monte Carlo simulation, will explore all major sources of beam loss in the Collider and measures to reduce the irradiation of the accelerator components. Basic parameters of the Super Collider accepted throughout this report are as follows: Proton energy E0 = 20 TeV, injection energy is 2 TeV, number of protons circulating in each of the collider rings is N = 1.3 x 1014, circumference is 87.12 km, the transverse normalized emittance var-epsilon N(σ) = 1 π mm-mrad, for the regular lattice (β = 305 m) the beam R.M.S. sizes are σ = 0.12 mm at 20 TEV and σ = 0.38 mm at the injection energy. The dipole length is 15.815 m with the effective field length of 15.165 m. The magnetic field map for B0 = 6.5999 T has been calculated with the POISSON program by Greg Snitchler. The turn angle of each dipole is α = 1.50027 mrad. The dipole aperture is 50 mm. The two beam pipe diameters are studied 33 and 40 mm. The operating temperature is T0 = 4.35 K

  5. 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...

  6. 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.

  7. Electron beam induced current in photovoltaics with high recombination

    OpenAIRE

    Haney, Paul M.; Yoon, Heayoung P.; Koirala, Prakash; Collins, Robert W.; Zhitenev, Nikolai B.

    2014-01-01

    Electron beam induced current (EBIC) is a powerful characterization technique which offers the high spatial resolution needed to study polycrystalline solar cells. Ideally, an EBIC measurement reflects the spatially resolved quantum efficiency of the device. In this work, a model for EBIC measurements is presented which applies when recombination within the depletion region is substantial. This model is motivated by cross-sectional EBIC experiments on CdS-CdTe photovoltaic cells which show th...

  8. 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 accelera- tor are identified and evaluated, and their impact on the beam dynamics, which in some cases could l...

  9. 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...

  10. Effective beam method for element concentrations

    International Nuclear Information System (INIS)

    A method to evaluate chemical element concentrations in samples by generating an effective polychromatic beam using as initial input real monochromatic beam data is presented. There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s)

  11. Effective beam method for element concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Tolhurst, Thomas; Barbi, Mauricio, E-mail: barbi@uregina.ca [University of Regina (Canada); Tokaryk, Tim [Royal Saskatchewan Museum (Canada)

    2015-01-29

    A method to evaluate chemical element concentrations in samples by generating an effective polychromatic beam using as initial input real monochromatic beam data is presented. There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s)

  12. Electron beam effects on gelatin polymer

    International Nuclear Information System (INIS)

    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)

  13. Experimental Studies of Compensation of Beam-Beam Effects with Tevatron Electron Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; /Fermilab; Alexahin, Yu.; Bishofberger, Kip; Kamerdzhiev, V.; Parkhomchuk, V.; Reva, V.; Solyak, N.; Wildman, D.; Zhang, X.-L.; Zimmermann, F.; /Fermilab /Los Alamos /Novosibirsk, IYF /CERN

    2008-02-01

    Applying the space-charge forces of a low-energy electron beam can lead to a significant improvement of the beam-particle lifetime limit arising from the beam-beam interaction in a high-energy collider [1]. In this article we present the results of various beam experiments with 'electron lenses', novel instruments developed for the beam-beam compensation at the Tevatron, which collides 980-GeV proton and antiproton beams. We study the dependencies of the particle betatron tunes on the electron beam current, energy and position; we explore the effects of electron-beam imperfections and noises; and we quantify the improvements of the high-energy beam intensity and the collider luminosity lifetime obtained by the action of the Tevatron Electron Lenses.

  14. Development of CNS Active Target for Deuteron Induced Reactions with High Intensity Exotic Beam

    Science.gov (United States)

    Ota, Shinsuke; Tokieda, H.; Lee, C. S.; Kojima, R.; Watanabe, Y. N.; Corsi, A.; Dozono, M.; Gibelin, J.; Hashimoto, T.; Kawabata, T.; Kawase, S.; Kubono, S.; Kubota, Y.; Maeda, Y.; Matsubara, H.; Matsuda, Y.; Michimasa, S.; Nakao, T.; Nishi, T.; Obertelli, A.; Otsu, H.; Santamaria, C.; Sasano, M.; Takaki, M.; Tanaka, Y.; Leung, T.; Uesaka, T.; Yako, K.; Yamaguchi, H.; Zenihiro, J.; Takada, E.

    An active target system called CAT, has been developed aiming at the measurement of deuteron induced reactions with high intensity beams in inverse kinematics. The CAT consists of a time projection chamber using THGEM and an array of Si detectors or NaI scintilators. The effective gain for the recoil particle is deisgned to be 5 - 10 × 103, while one for the beam is reduced by 102 using mesh grid to match the amplified signal to the dynamic range same as the one for recoil particle. The structure of CAT and the effect of the mesh grid are reported.

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

    International Nuclear Information System (INIS)

    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 1H-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.

  16. 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. PMID:26125388

  17. Turbulence-induced persistence in laser beam wandering

    CERN Document Server

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

    2015-01-01

    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.

  18. Ion beam induced fluorescence imaging in biological systems

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

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

  20. Biostimulative Effect Of Laser Beams

    Science.gov (United States)

    Mester, E.

    1981-05-01

    We report on experiences gained in healing clinical cases treated with He-Ne and Argon-laser grouped according to etiology. In order to elucidate the action mechanism of the bioregulatory process, the following experiments were carried out: 1. Serial electron-microscopic and radioactivity studies of samples obtained from human ulcers; 2. Chemical transfer of stimulating substrate on human leukocyte population; 3. Enzyme histochemical studies in experiments on rats; 4. Study of vascularization with the "ear chamber" technique carried out on rabbit's ear; 5. The increase of tensile strength in rats; 6. Biochemical demonstration of the RNA, DNA, albumin synthesis on human fibrocyte-cultures; 7.a, 7.b, Immunological studies; 8. Prostaglandin producing effect. The discovery of laser opened up new prospects in the field of the biological research and medical use.

  1. Transparency induced by two photon interference in a beam splitter

    Institute of Scientific and Technical Information of China (English)

    Wang Kai-Ge; Yang Guo-Jian

    2004-01-01

    We propose a special two-photon state which is completely transparent in a 50/50 beam splitter. This effect is caused by the destructive two-photon interference and shows the signature of photon entanglement. We find that the symmetry of the two-photon spectrum plays the key role for the properties of two-photon interference.

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

    CERN Document Server

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Ion beam induced luminescence (IBIL) has been used for studying the emission features and the radiation hardness of white pigments. In particular, ZnO, gypsum and basic lead sulphate pigments have been analyzed with a 3.0 MeV H+ beam at the AGLAE Louvre laboratory. The same pigments mixed with different binders have been also analyzed on a canvas, in order to evaluate the contribution of the binders both to the IBIL spectra and to the radiation hardness. It turns out that the binder affects both the IBIL spectra and the radiation hardness of pigments when the emission bands are related to point defects, as occurs for ZnO

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

    Science.gov (United States)

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

    2008-05-01

    Ion beam induced luminescence (IBIL) has been used for studying the emission features and the radiation hardness of white pigments. In particular, ZnO, gypsum and basic lead sulphate pigments have been analyzed with a 3.0 MeV H+ beam at the AGLAE Louvre laboratory. The same pigments mixed with different binders have been also analyzed on a canvas, in order to evaluate the contribution of the binders both to the IBIL spectra and to the radiation hardness. It turns out that the binder affects both the IBIL spectra and the radiation hardness of pigments when the emission bands are related to point defects, as occurs for ZnO.

  5. Effects of laser beam propagation in a multilevel photoionization system

    International Nuclear Information System (INIS)

    When the intense laser pulse propagates in the atomic vapor over a long distance, the laser pulse shape, the carrier frequency and the propagating velocity are greatly modified during the propagation by the resonant and/or the near-resonant interactions with atoms. We have been investigating these effects on the laser beam propagation experimentally and analytically. The simulation code named CEALIS-P has been developed, which employs the coupled three- level Bloch-Maxwell equations to study the atomic excitation and laser beam propagation simultaneously. Several features of the resonant and near-resonant effects based on the the self-induced transparency, the self-phase modulation and the nonlinear group velocity dispersion are described and the influences of such effects on the photoionization efficiency are analyzed.

  6. Effect of Proton Beam on Cancer Progressive and Metastatic Enzymes

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the effect of proton beam on enzymes for promotion/progression of carcinogenesis and metastasis of malignant tumor cells to clarify proton beam-specific biological effects. The changes of cancer chemopreventive enzymes in human colorectal adenocarcinoma HT-29 cells irradiated with proton beams were tested by measuring the activities of quinine reductase (QR), glutathione S-transferase (GST), and ornithine decarboxylase (ODC), glutathione (GSH) levels, and expression of cyclooxygenase-2 (COX-2). We also examined the effect of proton beam on the ODC activity and expression of COX-2 in human breast cancer cell. We then assessed the metastatic capabilities of HT-29 and MDA-MB-231 cells irradiated with proton beam by measuring the invasiveness of cells through Matrigel-coated membrane and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMP activity in MDA-MB-231 and HT-29 cells. QR activity of irradiated HT-29 cells was slightly increased. Proton irradiation at dose of 32 Gy in HT-29 cells increased GST activity by 1.23-fold. In addition GSH levels in HT-29 cells was significantly increased 1.23- (p<0.05), 1.32- (p<0.01) and 1.34-fold (p<0.01) with the proton irradiation at doses of 8, 16 and 32 Gy, respectively. These results suggest that colon cancer chemopreventive activity was increased with the proton irradiation by increasing QR and GST activities and GSH levels and inhibiting ODC activity. Proton ion irradiation decreased the invasiveness of TPA-treated HT-29 cells and MDA-MB-231 cells through Matrigel-coated membrane. Proton ion irradiation pretreatment decreased TPA-induced MMP activity in MDA-MB-231 and HT-29 cells. Further studies are necessary to investigate if these findings could be translated to in vivo situations

  7. Graphitic cage transformation by electron-beam-induced catalysis with alkali-halide nanocrystals

    Science.gov (United States)

    Fujita, Jun-ichi; Tachi, Masashi; Ito, Naoto; Murakami, Katsuhisa; Takeguchi, Masaki

    2016-05-01

    We found that alkali-halide nanocrystals, such as KCl and NaCl, have strong catalytic capability to form graphitic carbon cages from amorphous carbon shells under electron beam irradiation. In addition to the electron beam irradiation strongly inducing the decomposition of alkali-halide nanocrystals, graphene fragments were formed and linked together to form the final product of thin graphitic carbon cages after the evaporation of alkali-halide nanocrystals. The required electron dose was approximately 1 to 20 C/cm2 at 120 keV at room temperature, which was about two orders of magnitude smaller than that required for conventional beam-induced graphitization. The “knock-on” effect of primary electrons strongly induced the decomposition of the alkali-halide crystal inside the amorphous carbon shell. However, the strong ionic cohesion quickly reformed the crystal into thin layers inside the amorphous shell. The bond excitation induced by the electron beam irradiation seemed to enhance strongly the graphitization at the interface between the outer amorphous carbon shell and the inner alkali-halide crystal.

  8. Beam induced electron cloud resonances in dipole magnetic fields

    Science.gov (United States)

    Calvey, J. R.; Hartung, W.; Makita, J.; Venturini, M.

    2016-07-01

    The buildup of low energy electrons in an accelerator, known as electron cloud, can be severely detrimental to machine performance. Under certain beam conditions, the beam can become resonant with the cloud dynamics, accelerating the buildup of electrons. This paper will examine two such effects: multipacting resonances, in which the cloud development time is resonant with the bunch spacing, and cyclotron resonances, in which the cyclotron period of electrons in a magnetic field is a multiple of bunch spacing. Both resonances have been studied directly in dipole fields using retarding field analyzers installed in the Cornell Electron Storage Ring. These measurements are supported by both analytical models and computer simulations.

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

    International Nuclear Information System (INIS)

    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

  10. Industrial perspective on focused electron beam-induced processes

    Energy Technology Data Exchange (ETDEWEB)

    Bret, Tristan; Hofmann, Thorsten; Edinger, Klaus [Betriebsstaette Rossdorf, Carl Zeiss SMS GmbH, Rossdorf (Germany)

    2014-12-15

    After a short overview of the historical developments of the technique of gas-assisted focused electron beam-induced processing (mostly deposition and etching), this paper deals with the applications of this technology to photolithographic mask repair. A commented list of results is shown on different mask types, for different types of defects, and at different node generations. The scope of this article is double: summarize the state of the art in a fast-paced highly specific industrial environment driven by ''Moore's law'' and feedback to academic researchers some technologically relevant directions for further investigations. (orig.)

  11. Volume changes in glass induced by an electron beam

    International Nuclear Information System (INIS)

    Three glasses (float, borosilicate float and Schott D263 glasses) were irradiated by 50 keV electron beams with doses within the range of 0.21–318.5 kC/m2. Volume changes induced by electron bombarding were monitored by means of Atomic Force Microscopy. Incubation doses, related to mobility of alkali ions, were measured. Low doses showed compaction of all glasses while higher doses revealed volume inflation, except for borosilicate float glass. Both surfaces of float glass were irradiated and significant differences between them were found

  12. Sequence variations of in vitro pUC18 plasmid DNA induced by high energy 7Li ion beams implantation

    International Nuclear Information System (INIS)

    High energy heavy ion beams is a new mutagen for crop mutation breeding, but limited data are available on the molecular level induced by this mutagen. The in vitro pUC18 plasmid DNA was implanted by 7Li ion beams by doses of 0, 20, 40, 60, 80 and 100Gy, respectively, with the energy of 42.3Mev. The results showed that the damage effects induced by 7Li ion beams implantation was different from low LET rays, even low doses of 7Li ion beam could induce high damage on hydrogen bonds. Percentage of damages on hydrogen bonds of in vitro DNA induced by 7Li ion beams implantation increased with dosage increase up to 40Gy, then reduced with dosage increase, and higher than those of gamma rays in the same dosage. The relationship of dosage and damage percentage was different from that of gamma rays which was positive-linear correlation. Mutation frequency of 7Li ion beam implantation was 1.6 to 4.3 times to that of spontaneous mutation. The relationship of mutation frequency and dosage was similar with that of damage effects on hydrogen bonds, and showed a peak at 40Gy. The above results were identical with biological effects of wheat implanted by 7Li ion beams. Ten mutants were used for sequence analysis, which indicated that the types of base changes included base transversion, transition and deletion. Among all base changes detected, the frequency of bases transition (60%) was higher than that of bases transversion (30%) and bases deletion (10%). It seemed that thymine was more sensitive to the implantation than any other bases and base changes were mainly T→C and C→T. Bases between T and C were seemed to be easily induced by 7Li ion beams. The high percentage of DNA sequence variations could explain primarily the biological effects caused by 7Li ion beams in the M1 generation of crops. (author)

  13. Ion beam induced luminescence of germano-silicate optical fiber preform

    International Nuclear Information System (INIS)

    When an optical fiber is exposed to radiation, the attenuation (RIA, Radiation Induced Attenuation) in the optical fiber (OF) is increased because of the color centers which deteriorate the transmission property and generate the absorption loss. In order to understand the radiation induced defect, Ion Beam induced luminescence (IBIL) was introduced to investigate it. IBIL technique is to analyze IR/VIS/UV luminescence related to ion beam interaction with outer shell electrons involved in chemical bonds and structure defects of target atoms. So IBIL is sensitive to its chemical composition and has been used in analysis of material characterization, geological samples and cultural heritage objects. In silica material, four O atoms are surrounding one Si atom in tetrahedral coordination. In this study, the influence of Copper (Cu) and Cerium (Ce) dopants to germano silica core optical fibers were investigated under proton irradiation at RBI using Ion Beam induced luminescence (IBIL) method. To understand the radiation induced defect of optical fibers, IBIL were tested to a germano-silica core fiber under 2 MeV proton irradiation. Although a Cu or Ce dopant was not detected by IBIL technique, the relation between the amount of radiation and luminescence can be established. This experiment showed a potential technique of studying the effects and behavior of additive elements for silica core fiber. To increase the radiation resistance of optical fibers, further investigations are needed, i. e. the proper additives and its contents and an interaction mechanism between Ge-related defects and additives

  14. Focused ion beam induced deflections of freestanding thin films

    International Nuclear Information System (INIS)

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

  15. Ion beam induced luminescence analysis of painting pigments

    Energy Technology Data Exchange (ETDEWEB)

    Quaranta, A. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy); E-mail: quaranta@ing.unitn.it; Salomon, J. [Centre de Recherche et de Restauration des Musees de France, CNRS UMR 171, rue des Pyramides, 75041 Paris Cedex 01 (France); Dran, J.C. [Centre de Recherche et de Restauration des Musees de France, CNRS UMR 171, rue des Pyramides, 75041 Paris Cedex 01 (France); Tonezzer, M. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy); Della Mea, G. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy)

    2007-01-15

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields.

  16. Ion beam induced luminescence analysis of painting pigments

    International Nuclear Information System (INIS)

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields

  17. Ion beam induced luminescence analysis of painting pigments

    Science.gov (United States)

    Quaranta, A.; Salomon, J.; Dran, J. C.; Tonezzer, M.; Della Mea, G.

    2007-01-01

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields.

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

    International Nuclear Information System (INIS)

    The interaction of a relativistic beam with the modes of the TM010 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

  19. Gaussian Beam Effect on Equivalence Principle Test Using Free-Fall Interferometry

    Institute of Scientific and Technical Information of China (English)

    严琴; 周泽兵; 龙长才; 罗俊; 张元仲; 聂玉昕

    2002-01-01

    We discuss the Gaussian beam effect on the test of the equivalence principle using a free-fall interferometer.A two-lens assembly is used to improve the propagating character of the laser beam, and the beam radius is collimated to about 3.0 mm. The analysis shows that the gravity acceleration difference induced by the Gaussian beam effect could be less than 10-15 g for our double free-fall experimental design, but it would be 10-9 g for the absolute measurement of the gravity acceleration with the usual single free-fall method.

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

    International Nuclear Information System (INIS)

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

  1. Electron-Beam Induced Transformations of Layered Tin Dichalcogenides.

    Science.gov (United States)

    Sutter, E; Huang, Y; Komsa, H-P; Ghorbani-Asl, M; Krasheninnikov, A V; Sutter, P

    2016-07-13

    By combining high-resolution transmission electron microscopy and associated analytical methods with first-principles calculations, we study the behavior of layered tin dichalcogenides under electron beam irradiation. We demonstrate that the controllable removal of chalcogen atoms due to electron irradiation, at both room and elevated temperatures, gives rise to transformations in the atomic structure of Sn-S and Sn-Se systems so that new phases with different properties can be induced. In particular, rhombohedral layered SnS2 and SnSe2 can be transformed via electron beam induced loss of chalcogen atoms into highly anisotropic orthorhombic layered SnS and SnSe. A striking dependence of the layer orientation of the resulting SnS-parallel to the layers of ultrathin SnS2 starting material, but slanted for transformations of thicker few-layer SnS2-is rationalized by a transformation pathway in which vacancies group into ordered S-vacancy lines, which convert via a Sn2S3 intermediate to SnS. Absence of a stable Sn2Se3 intermediate precludes this pathway for the selenides, hence SnSe2 always transforms into basal plane oriented SnSe. Our results provide microscopic insights into the transformation mechanism and show how irradiation can be used to tune the properties of layered tin chalcogenides for applications in electronics, catalysis, or energy storage. PMID:27336595

  2. Proton beam characterization by proton-induced acoustic emission: simulation studies

    International Nuclear Information System (INIS)

    Due to their Bragg peak, proton beams are capable of delivering a targeted dose of radiation to a narrow volume, but range uncertainties currently limit their accuracy. One promising beam characterization technique, protoacoustic range verification, measures the acoustic emission generated by the proton beam. We simulated the pressure waves generated by proton radiation passing through water. We observed that the proton-induced acoustic signal consists of two peaks, labeled α and γ, with two originating sources. The α acoustic peak is generated by the pre-Bragg peak heated region whereas the source of the γ acoustic peak is the proton Bragg peak. The arrival time of the α and γ peaks at a transducer reveals the distance from the beam propagation axis and Bragg peak center, respectively. The maximum pressure is not observed directly above the Bragg peak due to interference of the acoustic signals. Range verification based on the arrival times is shown to be more effective than determining the Bragg peak position based on pressure amplitudes. The temporal width of the α and γ peaks are linearly proportional to the beam diameter and Bragg peak width, respectively. The temporal separation between compression and rarefaction peaks is proportional to the spill time width. The pressure wave expected from a spread out Bragg peak dose is characterized. The simulations also show that acoustic monitoring can verify the proton beam dose distribution and range by characterizing the Bragg peak position to within ∼1 mm. (paper)

  3. Dissipative effects in the beam-beam interaction of intersecting storage rings

    International Nuclear Information System (INIS)

    This proposal seeks continuing support for an ongoing research investigation of various dynamical instabilities which arise in high energy intersecting storage rings due to the beam-beam interaction. Although the dissipative effect of radiation in beam-beam machines is anticipated to be a dominant feature affecting stability in the dynamics of colliding beams of heavy particles, almost nothing is known regarding the stability problem in many-dimensional dissipative systems. The work proposed here will extend the earlier computations on weak instabilities in many-dimensional beam-beam models to include the effect of dissipation. The object of this research is to obtain conditions for global beam stability over long time scales as a function of the machine parameters

  4. 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)

  5. Relativistic Beaming Effect in Fermi Blazars

    Indian Academy of Sciences (India)

    J. H. Fan; D. Bastieri; J. H. Yang; Y. Liu; D. X. Wu; S. H. Li

    2014-09-01

    The most identified sources observed by Fermi/LAT are blazars, based on which we can investigate the emission mechanisms and beaming effect in the -ray bands for blazars. Here, we used the compiled around 450 Fermi blazars with the available X-ray observations to estimate their Doppler factors and compared them with the integral -ray luminosity in the range of 1–100 GeV. It is interesting that the integral -ray luminosity is closely correlated with the estimated Doppler factor, log = (2.95 ± 0.09) log + 43.59 ± 0.08 for the whole sample. When the dependence of the correlation between them and the X-ray luminosity is removed, the correlation is still strong, which suggests that the -ray emissions are strongly beamed.

  6. SOME PROPERTIES OF ATOMIC BEAM PRODUCED BY LASER INDUCED ABLATION OF Li TARGET

    OpenAIRE

    Harnafi, M.; Dubreuil, B.

    1987-01-01

    In this experiment, pulsed atomic beams produced in vacuum by laser induced ablation from lithium target are analyzed by laser-induced fluorescsence (LIF). As an application of this atomic beam production technique, the l-mixing processes induced in the n = 9, 10 Li Rydberg states by collisions with CO2 molecules have been investigated.

  7. Effects of Induced Astigmatism.

    Science.gov (United States)

    Schubert, Delwyn G.; Walton, Howard N.

    1968-01-01

    The relationship of astigmatism to reading and the possible detrimental effects it might have on reading were investigated. The greatest incidence of astigmatism was for the with-the-rule type ranging from .50 to 1.00 diopter. This type of astigmatism was induced in 35 seniors from the Los Angeles College of Optometry by placing cylindrical lenses…

  8. Effective beam method for element concentrations.

    Science.gov (United States)

    Tolhurst, Thomas; Barbi, Mauricio; Tokaryk, Tim

    2015-03-01

    There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s). PMID:25723941

  9. The effect of beam intensity on the estimation bias of beam position

    International Nuclear Information System (INIS)

    For the signals of the beam position monitor (BPM), the signal-to-noise ratio (SNR) is directly related to the beam intensity. Low beam intensity results in poor SNR. The random noise has a modulation effect on both the amplitude and phase of the BPM signals. Therefore, the beam position measurement has a certain random error. In the currently used BPM, time-averaging and waveform clipping are used to improve the measurement. The nonlinear signal processing results in a biased estimate of beam position. A statistical analysis was made to examine the effect of the SNR, which is determined by the beam intensity, on the estimation bias. The results of the analysis suggest that the estimation bias has a dependence not only on the beam position but also on beam intensity. Specifically, the dependence gets strong as the beam intensity decreases. This property has set a lower limit of the beam intensity range which the BPM's can handle. When the beam intensity is below that limit the estimation bias starts to vary dramatically, resulting in the BPMs failure. According to the analysis, the lowest beam intensity is that at which the SNR of the generated BPM signal is about 15 dB. The limit for NSEP BPM, for instance, is about 6Ell. The analysis may provide the BPM designers with some idea about the potential of the current BPM'S

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

    Indian Academy of Sciences (India)

    Zheng Jiao; Xiaojuan Wan; Bing Zhao; Huijiao Guo; Tiebing Liu; Minghong Wu

    2008-02-01

    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 dioxide thin films were simulated and the mechanism was discussed.

  11. Ion-beam-induced amorphous structures in silicon carbide

    International Nuclear Information System (INIS)

    Atomistic structure of ion-beam-induced amorphous silicon carbide (a-SiC) has been investigated by cross-sectional transmission electron microscopy. The electron intensities of halo patterns recorded on imaging plates were digitized quantitatively to extract reduced interference functions. We demonstrated the relationship between maximum scattering vector (Qmax) measured in scattering experiments and the resolution of the corresponding pair-distribution function by changing Qmax values from 160 to 230 nm-1. The results revealed that the C-C peak becomes broadened and eventually a shoulder as the Qmax value becomes shorter, indicating that Qmax values of -1 measured in previous studies are not enough to detect C-C homonuclear bonds in a-SiC. We are the first to reveal the existence of C-C and Si-Si homonuclear bonds in a-SiC using a diffraction technique

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

    International Nuclear Information System (INIS)

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

  13. Report on single beam stability - coherent effects

    International Nuclear Information System (INIS)

    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 1011 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.)

  14. The fine structure of the vortex-beams in the biaxial and biaxially-induced birefringent media caused by the conical diffraction

    CERN Document Server

    Fadeyeva, Tatyana; Anischenko, Pavel; Volyar, Alexander

    2011-01-01

    We consider the paraxial propagation of nondiffracting singular beams inside natural biaxial and biaxially-induced birefringent media in vicinity of one of the optical axes in terms of eigenmode vortex-beams, whose angular momentum does not change upon propagation. We have predicted a series of new optical effects in the natural biaxial crystals such as the stable propagation of vector singular beams bearing the coupled optical vortices with fractional topological charges, the conversion of the zero-order Bessel beam with a uniformly distributed linear polarization into the radially-, azimuthally- and spirally-polarized beams and the conversion of the space-variant linear polarization in the combined beam with coupled vortices. We have revealed that the field structure of the vortex-beams in the biaxially-induced crystals resembles that in the natural biaxial crystals and form the vector structure inherent in the conical diffraction. However, the mode beams in this case do not change the propagation direction...

  15. Direct and compound reactions induced by unstable helium beams near the Coulomb barrier

    Science.gov (United States)

    Navin, A.; Tripathi, V.; Blumenfeld, Y.; Nanal, V.; Simenel, C.; Casandjian, J. M.; de France, G.; Raabe, R.; Bazin, D.; Chatterjee, A.; Dasgupta, M.; Kailas, S.; Lemmon, R. C.; Mahata, K.; Pillay, R. G.; Pollacco, E. C.; Ramachandran, K.; Rejmund, M.; Shrivastava, A.; Sida, J. L.; Tryggestad, E.

    2004-10-01

    Reactions induced by radioactive 6,8 He beams from the SPIRAL facility were studied on 63,65 Cu and 188,190,192 Os targets and compared to reactions with the stable 4He projectiles from the Mumbai Pelletron. Partial residue cross sections for fusion and neutron transfer obtained from the measured intensities of characteristic in-beam γ rays for the 6He + 63,65 Cu systems are presented. Coincidence measurements of heavy reaction products, identified by their characteristic γ rays, with projectilelike charged particles, provide direct evidence for a large transfer cross section with Borromean nuclei 6He at 19.5 and 30 MeV and 8He at 27 MeV. Reaction cross sections were also obtained from measured elastic angular distributions for 6,8 He +Cu systems. Cross sections for fusion and direct reactions with 4,6 He beams on heavier targets of 188,192 Os at 30 MeV are also presented. The present work underlines the need to distinguish between various reaction mechanisms leading to the same products before drawing conclusions about the effect of weak binding on the fusion process. The feasibility of extracting small cross sections from inclusive in-beam γ -ray measurements for reaction studies near the Coulomb barrier with low intensity isotope separation on-line beams is highlighted.

  16. Effect of heavy ion beams on intratumoral radioresistant tumor cells

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate the radiobiological effect of heavy ion beams on radioresistant and radiosensitive human tumor cells. Tumors of human origin, an ependymoblastoma (EB) with wild-type (wt) p53, a primitive neuroectodermal tumor (PNET) with wt p53, and a glioblastoma (GB) with mutant-type (mt) p53, were transplanted to nude mice, and the mice were irradiated with carbon ion beams (290 MeV/u) or 200 kV X-rays. Tumors were excised 4, 6, or 24 hours after 2 Gy irradiation. A part of each tumor was fixed in formalin and embedded in paraffin. Thin sections were stained with H.E., GFAP or TUNEL for microscopic study. Total RNA was extracted for cDNA microarray analysis. In wt-p53 tumors, apoptosis increased 4 or 6 hours after irradiation. The tumors with wt-p53 showed significant changes in gene expression following 2 Gy irradiation. Pathway analysis of up- and down-regulated genes demonstrated that apoptosis, p53 signaling pathway, and cell cycle are involved significantly. There was little difference between the gene expression profiles induced by carbon ion beams and those by X-rays. In contrast, the tumor with mt-p53 showed much less change in gene expression after 2 Gy irradiation. But, the tumor showed significant changes 4, 6, or 24 hours after 8 Gy or 16 Gy irradiation, and the gene expression profiles induced by carbon ion beams were different from those by X-rays. p53, caspases, Fas, and TRAIL were not involved in the pathways, but NF-kB and IAP were suggested to be involved. (author)

  17. Photopolymerization-Induced Two-Beam Coupling and Light-Induced Scattering in Polymethyl Methacrylate

    International Nuclear Information System (INIS)

    Light amplification due to two-beam coupling is realized in doped polymethyl methacrylate (PMMA) glasses. A coupling gain as large as 14 cm-1 is obtained. The dynamic behaviour of absorption and light-induced scattering due to the process of photopolymerization are also studied. The results show that the amplification and its dynamic process enable possible applications of PMMA in optical devices. (fundamental areas of phenomenology (including applications))

  18. Effect of beam emittance on self-modulation of long beams in plasma wakefield accelerators

    CERN Document Server

    Lotov, K V

    2015-01-01

    The initial beam emittance determines the maximum wakefield amplitude that can be reached as a result of beam self-modulation in the plasma. The wakefield excited by the fully self-modulated beam decreases linearly with the increase of the beam emittance. There is a value of initial emittance beyond which the self-modulation does not develop even if the instability is initiated by a strong seed perturbation. The emittance scale at which the wakefield is twice suppressed with respect to the zero-emittance case (the so called critical emittance) is determined by inability of the excited wave to confine beam particles radially and is related to beam and plasma parameters by a simple formula. The effect of beam emittance can be observed in several discussed self-modulation experiments.

  19. 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.

  20. Ultra-low-energy (<10 eV/u) ion beam bombardment effect on naked DNA

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2014-05-01

    Highlights: • Decelerated ultra-low energy ion beam bombarded naked DNA. • DNA form change induced by ion bombardment was investigated. • N-ion bombardment at 32 eV induced DNA single and double strand breaks. • Ar-ion bombardment at a-few-hundreds eV induced DNA single strand break. - Abstract: Since ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range, it is very interesting to know effects from ultra-low-energy ion interaction with DNA for understanding ion-beam-induced genetic mutation. Tens-keV Ar- and N-ion beams were decelerated to ultra-low energy ranging from 20 to 100 eV, or only a few to 10 eV/u, to bombard naked plasmid DNA. The bombarded DNA was analyzed using gel electrophoresis for DNA form changes. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks after bombarded by tens-eV ion beam. N-ion beam was found more effective in inducing DNA change and mutation than Ar-ion beam. The study demonstrated that the ion bombardment with energy as low as several-tens eV was able to break DNA strands and thus potentially to cause genetic modification of biological cells. The experimental results were discussed in terms of direct atomic collision between the ions and DNA atoms.

  1. A Simplified Analysis of the Brazier Effect in Composite Beams

    DEFF Research Database (Denmark)

    Damkilde, Lars; Lund, B.

    2009-01-01

    In the design of windturbine blades composite beams are often used as the load bearing element. The beam is primarily subjected to bending moments, and the deformations are relatively large. The large displacements result in a kind of ovalization of the beam section, the so-called Brazier effect...

  2. Disruption effects from the collision of quasi-flat beams

    International Nuclear Information System (INIS)

    The disruption effects from the collision of round beams and flat beams in linear colliders have been studied in the past, and has by now been well understood. In practice, however, in the current SLC running condition and in several designs of the next generation linear colliders, the quasi-flat beam geometries are expected. Namely, the beam aspect ratio R ≡ σx/σy > 1, but not infinitely large. In this regime the disruption effects in both x and y dimensions should be carefully included in order to properly describe the beam-beam interaction phenomena. In this paper the author investigates two major disruption effects for the the quasi-flat beam regime: The luminosity enhancement factor and the effective beamstrahlung. Computer simulations are employed and simple scaling laws are deduced

  3. 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.

  4. Exact analytical solution of shear-induced flexural vibration of functionally graded piezoelectric beam

    Science.gov (United States)

    Sharma, Pankaj; Parashar, Sandeep Kumar

    2016-05-01

    The priority of this paper is to obtain the exact analytical solution for free flexural vibration of FGPM beam actuated using the d15 effect. In piezoelectric actuators, the potential use of d15 effect has been of particular interest for engineering applications since shear piezoelectric coefficient d15 is much higher than the other piezoelectric coupling constants d31 and d33. The applications of shear actuators are to induce and control the flexural vibrations of beams and plates. In this study, a modified Timoshenko beam theory is used where electric potential is assumed to vary sinusoidaly along the thickness direction. The material properties are assumed to be graded across the thickness in accordance with power law distribution. Hamilton`s principle is employed to obtain the equations of motion along with the associated boundary conditions for FGPM beams. Exact analytical solution is derived thus obtained equations of motion. Results for clamped-clamped and clamped-free boundary conditions are presented. The presented result and method shell serve as benchmark for comparing the results obtained from the other approximate methods.

  5. 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)

    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)

  6. Beam-shape effects in nonlinear Compton and Thomson scattering

    International Nuclear Information System (INIS)

    We discuss intensity effects in collisions between beams of optical photons from a high-power laser and relativistic electrons. Our main focus is on the modifications of the emission spectra due to realistic finite-beam geometries. By carefully analyzing the classical limit we precisely quantify the distinction between strong-field QED Compton scattering and classical Thomson scattering. A purely classical, but fully covariant, calculation of the bremsstrahlung emitted by an electron in a plane-wave laser field yields radiation into harmonics, as expected. This result is generalized to pulses of finite duration and explains the appearance of line broadening and harmonic substructure as an interference phenomenon. The ensuing numerical treatment confirms that strong focusing of the laser leads to a broad continuum while higher harmonics become visible only at moderate focusing, and hence lower intensity. We present a scaling law for the backscattered photon spectral density which facilitates averaging over electron beam phase space. Finally, we propose a set of realistic parameters such that the observation of intensity-induced spectral red shift, higher harmonics, and their substructure becomes feasible.

  7. A Note on the Sagnac Effect for Matter Beams

    CERN Document Server

    Ruggiero, Matteo Luca

    2014-01-01

    We study the Sagnac effect for matter beams, in order to estimate the kinematic corrections to the basic formula, deriving from the position and the extension of the interferometer, and discuss the analogy with the Aharonov-Bohm effect. We show that the formula for the Sagnac time delay is the same for matter and light beams in arbitrary stationary space-times, provided that a suitable condition on the speed of the beams is fulfilled. Hence, the same results obtained for light beams apply to matter beams.

  8. Effect of Electron beam on Prepared HAP-Gel Composition

    Directory of Open Access Journals (Sweden)

    Naima A. El Gendy*,Tawfik M. S.**, and Asma M. Nour

    2014-04-01

    Full Text Available Background: Polyvinyl alcohol liquid PVAl was used as the organic carrier for Hydroxylapatite-gel (Hap-gel composite. PVAl has the ability to form a nano- hydroxylapatite polyvinyl alcohol composite gel which has a wide range of uses in different environmental and medical applications. Prepared Hap-gel is known to have a very similar composition to human bone and is used as a substitute for bones in compound fractures and artificial dentures. Matreia and Methods: In this work prepared HAP- gel was exposed to a high ionizing radiation electron beam (5 kilo Gray and an aqueous solution containing aluminum ions (Al+. Some investigations were done to illustrate the effect of radiation exposure and aluminum contamination on prepared Hap-gel. Results: Energy dispersive X-ray analysis (EDx showed that the electron beam used caused an obvious increase in the calcium ions (Ca++ content of the prepared Hap-gel from 60% to 65.69 % with a prominent decrease in phosphorus ions (P + content from 40 % to 34.31 % in addition to an increase in the Ca/P ratio from 1.5 to 1.91. Exposure of the pre-irradiated Hap-gel samples to aluminium ions (Al+ resulted in a noticeable decrease in Ca++ content from 65.69 atomic % to 32.14 % atomic % and a further noticeable decrease in P+ content from 34.31 % atomic % to 13 atomic % as well as an increase in the Ca/P ratio from 1.91 to 2.47. The levels for the original prepared Hap-gel were Ca++; 60 atomic % and P+; 40 atomic %. It was deduced that exposure of the Hap-gel to Al+ had a further damaging effect on the pre-irradiated Hap-gel composition in addition to the damaging effect that the electron beam used induced on the samples. Conclusions: it could be concluded that electron beams and Al+ have an injurious effect on human bone tissue taking into consideration the similarity in composition between Hap-gel and bones. Therefore, this study could be beneficial in the field of osteoporosis research and assist the

  9. Stern-Gerlach Effect for Electron Beams

    International Nuclear Information System (INIS)

    The conflict between Bohr close-quote s assertion that the magnetic moment of the electron cannot be measured with experiments based on the concept of classical trajectories, and the measurement of the magnetic moment of electrons in a modified Penning trap by Dehmelt et al.has led us to reevaluate other implications of Bohr close-quote s assertion. We show that, contrary to the analysis of Bohr and Pauli, the assumption of classical trajectories in a Stern-Gerlach endash like device can result in a high degree of spin separation for an electron beam. This effect may persist within a fully quantum-mechanical analysis. The magnetic fields considered are such that a tabletop Stern-Gerlach electron spin filter is feasible. copyright 1997 The American Physical Society

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

    International Nuclear Information System (INIS)

    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 1014 W/cm2) 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 energy

  11. Radiation induced currents in parallel plate ionization chambers: Measurement and Monte Carlo simulation for megavoltage photon and electron beams

    International Nuclear Information System (INIS)

    Polarity effects in ionization chambers are caused by a radiation induced current, also known as Compton current, which arises as a charge imbalance due to charge deposition in electrodes of ionization chambers. We used a phantom-embedded extrapolation chamber (PEEC) for measurements of Compton current in megavoltage photon and electron beams. Electron contamination of photon beams and photon contamination of electron beams have a negligible effect on the measured Compton current. To allow for a theoretical understanding of the Compton current produced in the PEEC effect we carried out Monte Carlo calculations with a modified user code, the COMPTON/EGSnrc. The Monte Carlo calculated COMPTON currents agree well with measured data for both photon and electron beams; the calculated polarity correction factors, on the other hand, do not agree with measurement results. The conclusions reached for the PEEC can be extended to parallel-plate ionization chambers in general

  12. Research on biological effects of radioactive ion beam

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the potential importance of radioactive ion beams such as 9C, 8B and 8Li, representing double radiation sources coming from the external beams themselves and the delayed particles emitted internally, in medical use, cell radiobiological experiments using radioactive 8B beam and corresponding comparable 10B-ion beam were carried out in the secondary beam line (SBL) at Heavy Ion Medical Accelerator in Chiba (HIMAC). In these radiobiological experiments, biological endpoints such as survival fraction, micronucleus frequency and γ-H2AX focus induction at different penetration depths around the Bragg peaks along these beams were measured. Because human salivary gland (HSG) cancer cells were used in the experiments, it is hard to evaluate the biological effectiveness of the radioactive 8B beam exactly based on the results obtained in the radiobiological experiments. Therefore, normal cell line is expected to be employed in future experiments. In addition, a primary 10B beam of 100 MeV/u was used to produce radioactive 8Li beam under the conditions of 6 mm thick Beryllium target and 3.5 mm thick Aluminum degrader in the SBL at HIMAC. The lateral fluence distributions of the produced beam were measured at different penetration depths along the beam direction. To keep the uniformity of the irradiation field suitable for radiobiological experiments using the produced 8Li beam, a narrow momentum width has to be applied so that the beam intensity decreases. (author)

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

    Science.gov (United States)

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

    2013-06-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wongkham, W. [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sangwijit, K.; Inthanon, K. [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wanichapichart, P. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Membrane Science and Technology Research Center, Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkla 90112 (Thailand); Anuntalabhochai, S. [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-06-15

    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.

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

    International Nuclear Information System (INIS)

    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.

  16. Beam induced annealing of damage in carbon implanted silicon, ch. 4

    International Nuclear Information System (INIS)

    The annealing of damage introduced by 70 keV C implantation of Si is studied for impact of H+ and He+ beams in the energy interval 30 - 200 keV. For a good description of the annealing behaviour it is necessary to account for the damage introduction which occurs simultaneously. It turns out that the initial damage annealing rate is proportional to the amount of damage. The proportionality constant is related to the quantity fsub(a)sigmasub(a) introduced in an earlier paper in order to describe saturation effects in the damage production after H+ or He+ impact in unimplanted Si. This indicates that the same mechanism governs both processes: beam induced damage annealing and saturation of the damage introduction. (Auth.)

  17. Ion-beam-induced epitaxial crystallization of implanted and chemical vapor deposited amorphous silicon

    Science.gov (United States)

    La Ferla, A.; Priolo, F.; Spinella, C.; Rimini, E.; Baroetto, F.; Ferla, G.

    1989-03-01

    The dependence of ion-beam enhanced epitaxial growth of amorphous Si layers on impurities either dissolved in the film or present at the film-substrate interface is considered. In the case of ion implanted layers, electrically active dopants, like B, P, As at concentrations above 1 × 10 20/cm 3, enhance the rate by a factor of 2 with respect to the undoped layer. The enhancement shows also a weak dependence on the dopant concentration. Inert impurities, like Ar, which prevent pure thermal regrowth, do not show any appreciable influence on the ion-beam-induced growth rate. Chemical vapor deposited Si layers with a thin native interfacial oxide layer can also be epitaxially regrown under ion irradiation. A critical fluence is needed before the interfacial oxide breaks down and broadens, allowing the epitaxial crystallization to take place. This process is characterized by an activation energy of 0.44 eV. The complex phenomenon of ion-beam-induced crystallization involves a dynamical interaction between production and annealing of point defects. The presence of electrically active dopants probably influences the lifetime of point defects. Impurities which prevent thermal regrowth are instead dissolved by ballistic effects and/or radiation-enhanced mixing.

  18. Wakefield effects in the SLC beam delivery system

    International Nuclear Information System (INIS)

    Wakefield effects occurring in the SLC after the LI28 emittance measurement station could be responsible for part of all of the observed discrepancy between the expected vertical spot sizes at the IP and the measured ones. The strongest wakefields are generated by the parts of the beam chamber which are the closest to the beam, like collimators. In this note we review the effect of the following wakefield sources: geometric wakefields from final focus fixed and movable collimators, geometric and resistive wakefields from linac collimators jaws, resistive wakefields from the beam pipe at the sextupole and final transformer locations. We mostly concentrate on the transverse dipole and quadrupole wakefield effects, although the longitudinal wakefields are briefly studied at the end. We limit ourselves to the vertical beam dynamics and to the lowest (mainly linear) order of the wakefield expansion with respect to the beam offset, which excludes the near wall effect on the beam. (author)

  19. Impact of Long Range Beam-Beam Effects on Intensity and Luminosity Lifetimes from the 2015 LHC Run

    CERN Document Server

    Crouch, Matthew; Banfi, Danilo; Barranco, Javier; Bruce, Roderik; Buffat, Xavier; Muratori, Bruno; Pieloni, Tatiana; Pojer, Mirko; Salvachua, Belen; Tambasco, Claudia; Trad, Georges

    2016-01-01

    Luminosity is one of the key parameters that determines the performance of colliding beams in the Large Hadron Collider (LHC). Luminosity can therefore be used to quantify the impact of beam-beam interactions on the beam lifetimes and emittances. The High Luminosity Large Hadron Collider (HL-LHC) project aims to reach higher luminosities, approximately a factor of 7 larger than the nominal LHC at peak luminosity without crab cavities. Higher luminosities are achieved by increasing the bunch populations and reducing the transverse beam sizes. This results in stronger beam-beam effects. Here the LHC luminosity and beam intensity decay rates are analysed as a function of reducing beam separation with the aim of characterising the impact of beam-beam effects on the luminosity and beam lifetime. The analysis and results are discussed with possible application to the HL-LHC upgrade.

  20. Electron beam irradiation induces abnormal development and the stabilization of p53 protein of American serpentine leafminer, Liriomyza trifolii (Burgess)

    International Nuclear Information System (INIS)

    The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests worldwide. In this study, we determined electron beam doses for inhibition of normal development of the leaf miner and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs (0-24 h old), larvae (2nd instar), puparia (0-24 h old after pupariation) and adults (24 h after emergence) were irradiated with increasing doses of electron beam irradiation (six levels between 30 and 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and puparia was lower than in the untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein within 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for female sterilization of L. trifolii. - Highlights: → Electron beam irradiation inhibited normal development of the leaf miner. → Electron beam irradiation inhibited normal reproduction of the leaf miner. → Electron beam irradiation increased levels of DNA damage. → Electron beam irradiation induced p53 stability.

  1. Electron beam irradiation induces abnormal development and the stabilization of p53 protein of American serpentine leafminer, Liriomyza trifolii (Burgess)

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Hyun-Na; Yun, Seung-Hwan; Yoon, Changmann [Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Kim, Gil-Hah, E-mail: khkim@chungbuk.ac.kr [Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)

    2012-01-15

    The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests worldwide. In this study, we determined electron beam doses for inhibition of normal development of the leaf miner and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs (0-24 h old), larvae (2nd instar), puparia (0-24 h old after pupariation) and adults (24 h after emergence) were irradiated with increasing doses of electron beam irradiation (six levels between 30 and 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and puparia was lower than in the untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein within 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for female sterilization of L. trifolii. - Highlights: > Electron beam irradiation inhibited normal development of the leaf miner. > Electron beam irradiation inhibited normal reproduction of the leaf miner. > Electron beam irradiation increased levels of DNA damage. > Electron beam irradiation induced p53 stability.

  2. Space-charged-induced emittance growth in the transport of high-brightness electron beams

    International Nuclear Information System (INIS)

    The emittance induced by space charge in a drifting beam of finite length has been investigated, and a scaling law has been obtained from simple considerations of the different rates of expansion of different portions of the beam. The scaling law predicts the initial rate of emittance growth, before the beam shape has distorted significantly, and thus represents an upper bound on the rate of emittance increase. This scaling law has been substantiated by particle-in-cell simulation and the dependence on geometric factors evaluated for specific choices of the beam profile. For long, axially nonuniform beams, the geometric factors have been evaluated explicitly for Gaussian profiles, and other shapes

  3. Deflection, spraying and induced scattering of intense laser beams in plasmas

    International Nuclear Information System (INIS)

    Investigations into laser beam spraying, deflection and induced scattering in plasmas are presented. Recent calculations and experiments on beam spraying due to filamentation are discussed. A simple model is presented for an enhanced beam deflection associated with nearly sonic plasma flow transverse to the beam. This model provides useful insights on the laser beam deflection, its scaling and the importance of self-consistent profile modifications. Finally, some discussion is given of recent experiments demonstrating the interplay between stimulated Raman and Brillouin scattering. (Author)

  4. Deflection, spraying, and induced scattering of intense laser beams in plasmas

    International Nuclear Information System (INIS)

    Investigations into laser beam spraying, deflection, and induced scattering in plasmas are presented. Recent calculations and experiments on beam spraying due to filamentation are discussed. A simple model is presented for an enhanced beam deflection associated with nearly sonic plasma flow transverse to the beam. This model provides useful insights on the laser beam deflection, its scaling and the importance of self-consistent profile modifications. Finally, some discussion is given of recent experiments demonstrating the interplay between stimulated.Raman and Brillouin scattering

  5. Numerical Simulation on Expansion Process of Ablation Plasma Induced by Intense Pulsed Ion Beam

    Institute of Scientific and Technical Information of China (English)

    TAN Chang; LIU Yue; WANG Xiao-Gang; MA Teng-Cai

    2006-01-01

    We present a one-dimensional time-dependent numerical model for the expansion process of ablation plasmainduced by intense pulsed ion beam(IPIB).The evolutions of density,velocity,temperature,and pressure of theablation plasma of the aluminium target are obtained.The numerical results are well in agreement with therelative experimental data.It is shown that the expansion process of ablation plasma induced by IPIB includesstrongly nonlinear effects and that shock waves appear during the propagation of the ablation plasma.

  6. Beam Induced Background Simulation Studies at IR1 with New High Luminosity LHC Layout

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00218654; Gibson, Stephen; Bruce, Roderik; Cerutti, Francesco; Esposito, Luigi Salvatore; Lechner, Anton

    2015-01-01

    In the High Luminosity LHC (HL-LHC), the collimation system will be upgraded in the high-luminosity experimental regions. Additional protection is planned for the Q4 and Q5 magnets that are located further upstream of the tertiary collimators that protect the inner triplet magnets. We evaluate the effect of this proposed collimation layout for the incoming beam 1 on machine-induced background in the experimental area of IR1 (ATLAS). The main scenario is the round optics with β$^∗$ of 15 cm, but a flat scenario is also briefly discussed

  7. Controllable Airy-like beams induced by tunable phase patterns

    Science.gov (United States)

    Li, D.; Qian, Y.

    2016-01-01

    We propose and experimentally observe a novel family of Airy-like beams. First, we theoretically investigate the physical generation of our proposed controllable Airy-like beams by introducing a rotation angle factor into the phase function, which can regulate and flexibly control the beam wavefront. Meanwhile we can also readily control the main lobes of these beams to follow appointed parabolic trajectories using the rotation angle factor. We also demonstrate that the controllable Airy-like beams lack the properties of being diffraction-free and self-healing. The experiments are performed and the results are in accord with the theoretical simulations. We believe that the intriguing characteristics of our proposed Airy-like beams could provide more degrees of freedom, and are likely to give rise to new applications and lend versatility to the emerging field.

  8. A study of beam-beam effects in hadron colliders with a large number of bunches

    CERN Document Server

    Pieloni, Tatiana; Bay, Aurelio; Rivkin, Leonid

    2008-01-01

    A particle beam is a collection of a large number of charges and represents an electromagnetic potential for other charges, therefore exerting forces on itself and other beams. The control of this so called Beam-Beam Interactions (BBIs) in particle colliders is fundamental to preserve beam stability and achieve the collider maximal luminosity. In the case of the Large Hadron Collider (LHC) at CERN, these forces are experienced as localized periodic distortions when the two beams cross each other in the four experimental areas. The forces are most important for high density beams, i.e. high intensity and small beam sizes. Each LHC beam is composed of 2808 bunches, each containing $10^{11}$ protons and with a transverse size of 16~$\\mu $m at the interaction points. These extreme parameters are the key to obtain high ``luminosity'', i. e. the number of collisions per second needed to study rare physics phenomena. The BBI is therefore often the limiting factor for the luminosity of colliders. Within all BB effect...

  9. Helicopter engine exhaust rotor downwash effects on laser beams

    Science.gov (United States)

    Henriksson, Markus; Sjöqvist, Lars; Seiffer, Dirk

    2015-10-01

    The hot exhaust gases from engines on helicopters are pushed down by the rotor in a turbulent flow. When the optical path of a laser beam or optical sensor passes through this region severe aberrations of the optical field may result. These perturbations will lead to beam wander and beam distortions that can limit the performance of optical countermeasure systems. To quantify these effects the Italian Air Force Flight Test Centre hosted a trial for the "Airborne platform effects on lasers and warning sensors" (ALWS) EDA-project. Laser beams were propagated from the airport control tower to a target screen in a slant path with the helicopter hovering over this path. Collimated laser beams at 1.55-, 2- and 4.6-μm wavelength were imaged with high speed cameras. Large increases in beam wander and beam divergence were found, with beam wander up to 200 μrad root-mean-square and increases in beam divergence up to 1 mrad. To allow scaling to other laser beam parameters and geometries formulas for propagation in atmospheric turbulence were used even though the turbulence may not follow Kolmogorov statistics. By assuming that the plume is short compared to the total propagation distance the integrated structure parameter through the plume could be calculated. Values in the range 10-10 to 10-8 m1/3 were found when the laser beams passed through the exhaust gases below the helicopter tail. The integrated structure parameter values calculated from beam wander were consistently lower than those calculated from long term spot size, indicating that the method is not perfect but provides information about order of magnitudes. The measured results show that the engine exhaust for worst case beam directions will dominate over atmospheric turbulence even for kilometer path lengths from a helicopter at low altitude. How severe the effect is on system performance will depend on beam and target parameters.

  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. Lethal and mutagenic effects of ion beams and γ-rays in Aspergillus oryzae

    International Nuclear Information System (INIS)

    Highlights: ► We investigated the effects of different LET radiation in A. oryzae. ► Both γ-rays and ion beams induced base substitutions, frameshifts, deletions. ► Both γ-rays and ion beams induced genome-wide large-scale mutations in A. oryzae. ► Some differences in the types and frequencies of mutations were found. ► Our results provide new basic insights into the mutation breeding of A. oryzae. - Abstract: Aspergillus oryzae is a fungus that is used widely in traditional Japanese fermentation industries. In this study, the lethal and mutagenic effects of different linear energy transfer (LET) radiation in freeze-dried conidia of A. oryzae were investigated. The lethal effect, which was evaluated by a 90% lethal dose, was dependent on the LET value of the ionizing radiation. The most lethal ionizing radiation among that tested was 12C5+ ion beams with an LET of 121 keV/μm. The 12C5+ ion beams had a 3.6-times higher lethal effect than low-LET (0.2 keV/μm) γ-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. 12C6+ ion beams with an LET of 86 keV/μm were the most effective in inducing selenate resistance. The mutant frequency following exposure to 12C6+ ion beams increased with an increase in dose and reached 3.47 × 10−3 at 700 Gy. In the dose range from 0 to 700 Gy, 12C5+ ion beams were the second most effective in inducing selenate resistance, the mutant frequency of which reached a maximum peak (1.67 × 10−3) at 400 Gy. To elucidate the characteristics of mutation induced by ionizing radiation, mutations in the sulphate permease gene (sB) and ATP sulfurylase gene (sC) loci, the loss of function of which results in a selenate resistant phenotype, were compared between 12C5+ ion beams and γ-rays. We detected all types of transversions and transitions. For frameshifts, the frequency of a +1 frameshift was the highest in all cases. Although the incidence of deletions >2 bp was generally low, deletions >20

  12. Beam-Induced Deposition of Thin Metallic Films.

    Science.gov (United States)

    Funsten, Herbert Oliver, III

    1990-01-01

    Ion and electron beam induced deposition (BID) of thin (1 μm), conductive films is accomplished by dissociating and removing the nonmetallic components of an adsorbed, metal-based, molecular gas. Current research has focused primarily on room temperature (monolayer adsorption) BID using electrons and slow, heavy ions. This study investigates low temperature (50 to 200 K) BID in which the condensation of the precursor gases (SnCl _4 and (CH_3) _4Sn) maximizes the efficiency of the incident radiation which can create and remove nonmetallic fragments located several monolayers below the film surface. The desired properties of the residual metallic films are produced by using as incident radiation either nuclear (35 keV Ar ^+) or electronic (2 keV electrons, 25 keV H^+, or 50 keV H ^+) energy loss mechanisms. Residual films are analyzed ex situ by Scanning Electron Microscopy (SEM), thickness measurements, resistivity measurements, Rutherford Backscattering Spectroscopy (RBS), and infrared spectroscopy. Low temperature BID film growth models, which are derived from both a computer simulation and a mathematical analysis, closely agree. Both the fragmentation and sputtering cross sections for a particular ion and energy are derived for films created from (CH_3) _4Sn. The fragmentation cross section, which corresponds to film growth, is roughly related to the electronic stopping power by the 1.9 power. The loss of carbon in films which were created from (CH_3) _4Sn is strongly dependent on the nuclear stopping power. Film growth rates for low temperature BID have been found to be 10 times those of room temperature BID.

  13. Electron beam induced degradation of clopyralid in aqueous solutions

    International Nuclear Information System (INIS)

    The degradation characteristics of clopyralid irradiated by electron beam (EB) was studied in aqueous solutions. The effects of factors, such as initial clopyralid concentrations, addition of radicals scavenger, initial solution pH and addition of H2O2, were investigated on clopyralid degradation efficiency and mechanism. It was found that the EB-radiolysis was an effective way to degrade clopyralid and its degradation rate decreased with the increasing of substrate concentration. In the investigated initial concentrations range of 100-400 mg L-1, the radiolytic degradation of clopyralid followed a pseudo-first kinetic order. The results from addition of radicals scavenger indicated that both ·OH and eaq- played significant roles in the degradation of clopyralid. Furthermore, the alkaline condition and addition of H2O2 (<10 mM) in the solution also slightly enhanced the efficiency of clopyralid degradation. The ion chromatography analysis showed that some organic acids (formic acid, acetic acid and oxalic acid) were formed, while the completely dechlorination of the substrate was achieved and organic nitrogen was recovered in the form of ammonium and nitrate ions during the irradiation process. (author)

  14. Focused electron beam induced deposition as a tool to create electron vortices.

    Science.gov (United States)

    Béché, A; Winkler, R; Plank, H; Hofer, F; Verbeeck, J

    2016-01-01

    Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be ∼0.8ℏ per electron with almost 60% of the beam ending up in the ℓ=1 state. PMID:26432987

  15. Beam orbit storage effect in the isochronous cyclotrons

    International Nuclear Information System (INIS)

    The BOS-effect is useful to apply in many isochronous cyclotron operated for today. Some general advantages are pointed out below: 1) the storage orbits effect may be utilized in order to increasing the internal space charge in a given extraction zone (for instance medical isotope production and other applications on internal beam); 2) returning of the unextracted beam to the space of quasi stable acceleration region (n ≥ 0), will caused decreasing activity of construction elements of cyclotron. This is very important problem by exploitation on high intensity internal beams; 3) because of avoiding the internal beam losses on constructions elements, as well longitudinal extension of the beam and also change of the angle in radial emittance during the second accelerations process it is to expect a magnifying of the extracted beam. (author). 7 refs, 21 figs

  16. Beam-induced energy deposition issues in the Very Large Hadron Collider

    CERN Document Server

    Mokhov, N V; Foster, G W

    2001-01-01

    Energy deposition issues are extremely important in the Very Large Hadron Collider (VLHC) with huge energy stored in its 20 TeV (Stage-1) and 87.5 TeV (Stage-2) beams. The status of the VLHC design on these topics, and possible solutions of the problems are discussed. Protective measures are determined based on the operational and accidental beam loss limits for the prompt radiation dose at the surface, residual radiation dose, ground water activation, accelerator components radiation damage and quench stability. The beam abort and beam collimation systems are designed to protect accelerator from accidental and operational beam losses, IP region quadrupoles from irradiation by the products of beam-beam collisions, and to reduce the accelerator-induced backgrounds in the detectors. (7 refs).

  17. Analytical treatment of the nonlinear electron cloud effect and the combined effects with beam-beam and space charge nonlinear forces in storage rings

    Institute of Scientific and Technical Information of China (English)

    GAO Jie

    2009-01-01

    In this paper we treat first some nonlinear beam dynamics problems in storage rings, such as beam dynamic apertures due to magnetic multipoles, wiggles, beam-beam effects, nonlinear space charge effect, and then nonlinear electron cloud effect combined with beam-beam and space charge effects, analytically. This analytical treatment is applied to BEPC Ⅱ. The corresponding analytical expressions developed in this paper are useful both in understanding the physics behind these problems and also in making practical quick hand estimations.

  18. Stress-induced waveguides in Nd:YAG by simultaneous double-beam irradiation with femtosecond pulses

    Science.gov (United States)

    Castillo, Gabriel R.; Romero, Carolina; Lifante, Ginés; Jaque, Daniel; Chen, Feng; Varela, Óscar; García-García, Enrique; Méndez, Cruz; Camacho-López, Santiago; Vázquez de Aldana, Javier R.

    2016-01-01

    We report on the fabrication of stress-induced waveguides in Nd:YAG (neodymium doped yttrium aluminum garnet, Nd:Y3Al5O12) by simultaneous double-beam irradiation with femtosecond laser pulses. An interferometer was used to generate two femtosecond laser beams that, focused with certain lateral separation inside the crystal, produced two parallel damage tracks with a single scan. The propagation of the mechanical waves simultaneously created in both focal spots produced a highly symmetrical stress field that is clearly revealed in micro-luminescence maps. The optical properties of the double-beam waveguides are studied and compared to those of single-beam irradiation, showing relevant differences. The creation of more symmetric stress patterns and a slight reduction of propagation losses are explained in terms of the fact that simultaneous inscription allows for a drastic reduction in the magnitude of "incubation" effects related to the existence of pre-damaged states.

  19. Reaction mechanisms in collisions induced by 8B beam close to the barrier

    CERN Multimedia

    The aim of the proposed experiment is to investigate on 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 $^{8}$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.

  20. Radiation effects on thin-oxide MOS capacitors caused by electron beam evaporation of aluminium

    International Nuclear Information System (INIS)

    The effects of electron-beam evaporation of Al on fast surface states, oxide charges and generation lifetime in MOS capacitors were studied. Fast surface states were increased when the thickness of the oxide was reduced to less than 400 A. Negative charges were induced near the Al/SiO2 interface. Both negative charges and fast surface states were reduced by using higher deposition temperatures, even though deposition temperatures were lower than post-metallization-annealing temperatures. Generation centers were also induced by electron beam evaporation. However, such generation centers were removed completely by the cleaning of furnace tubes with HCl. (author)

  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. Refractive index changes induced by sheet beams with various intensity distributions in LiNbO3:Fe crystal

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Peng; ZHAO; Jianlin; XU; Honglai; SUN; Yidong; YANG

    2005-01-01

    According to the Kukhtarev equations and a simplified model based on the photovoltaic charge carriers transport mechanism, the distributions of the index changes (DICs) in LiNbO3:Fe crystals induced by sheet beams with various intensity profiles are theoretically analyzed. The numerically simulated results coincide with the analytic expressions deduced from the simplified model. The DICs in a LiNbO3:Fe crystal induced by sheet beams with rectangular, Gaussian and square law profiles are measured by using the interferometric method. By employing the analytic expressions, the experimental data points are well fitted. By utilizing the angular spectrum theory and the ray equation, the uniformities of the intensity profiles of the writing beams along the propagation directions and the influences of the self-defocusing effect of the crystal are numerically simulated, respectively. The results show that the experimental results are reliable. The numerically simulated method and the analytic expressions can be both employed to predict the DICs induced by sheet beams with various light intensity profiles. Furthermore, utilizing writing beams with proper intensity profiles, any desired index distributions could be obtained.

  3. Physico-chemical study of the focused electron beam induced deposition process

    OpenAIRE

    Bret, Tristan; Hoffmann, Patrik

    2007-01-01

    The focused electron beam induced deposition process is a promising technique for nano and micro patterning. Electrons can be focused in sub-angström dimensions, which allows atomic-scale resolution imaging, analysis, and processing techniques. Before the process can be used in controlled applications, the precise nature of the deposition mechanism must be described and modelled. The aim of this research work is to present a physical and chemical description of the focused electron beam induc...

  4. Preparation of a beam quality indicator for effective energy determinations of continuum beams: establishment of traceability

    CERN Document Server

    Matsubayashi, M; Kobayashi, H

    1999-01-01

    A new beam quality indicator (BQI) was designed and fabricated to determine effective energies of beams extracted from neutron radiography facilities. Performances of the five new BQIs were compared with the original BQI which was recently proposed and tested by various beams. Non-filtered thermal neutrons, filtered thermal neutrons, and cold neutrons from a guide tube were used in the performance test program. The new BQIs were also examined by four different detection systems using a combination of a Gd converter and a X-ray film, a neutron imaging plate, a cooled charge coupled device camera, and a silicon intensified target tube camera.

  5. 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.

  6. 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.

  7. Effect of rf structure on cumulative beam breakup

    International Nuclear Information System (INIS)

    We treat the effect of rf structure of a linac beam on cumulative beam breakup in the presence of external focusing. Starting with the difference equations of Helm and Loew, we derive two forms of an exact analytic solution for coasting beams: as a sum of products of Gegenbauer polynomials involving external focusing and rf structure, and as an integral involving these same parameters. The continuous-beam limit of Neil, Hall, and Cooper is obtained as the bunch separation goes to zero. An explicit solution is presented for the steady state, including modulation of the incoming displacement, showing both stable and unstable behavior with distance. Asymptotic amplitude expressions are derived for the transient solution, which can lead to even larger beam displacements. Approximate solutions also are obtained for accelerated and decelerated beams. Comparison with numerical simulations are presented

  8. Focused ion beam irradiation effects on nanoscale freestanding thin films

    International Nuclear Information System (INIS)

    The focused ion beam (FIB) technique is a versatile tool for nanoscale manipulation, deposition and etching. However, degradation mechanisms which lead to residual stresses in materials exposed to high-energy ion beams are not well understood. In this study, we examine the evolution of residual stresses in 100 nm thick freestanding aluminum films subjected to typical ion beam exposures within a commercial FIB tool. Experimental results show that the magnitude of the residual stresses increase with cumulative ion beam exposure and that upper limits are attainable. Further investigation demonstrates that a decrease in ion beam current at constant acceleration-voltage augments the upper limits, which manifests itself in greater residual stresses. The stress gradients in thin films develop from surface modifications in the form of amorphous top layers, which are modeled as bilayer approximations. Experimental observations and analysis indicate that ion beam exposure effects on the mechanical properties of nanoscale thin films and nanostructures cannot be ignored

  9. Two Effective Heuristics for Beam Angle Optimization in Radiation Therapy

    CERN Document Server

    Yarmand, Hamed

    2013-01-01

    In radiation therapy, mathematical methods have been used for optimizing treatment planning for delivery of sufficient dose to the cancerous cells while keeping the dose to critical surrounding structures minimal. This optimization problem can be modeled using mixed integer programming (MIP) whose solution gives the optimal beam orientation as well as optimal beam intensity. The challenge, however, is the computation time for this large scale MIP. We propose and investigate two novel heuristic approaches to reduce the computation time considerably while attaining high-quality solutions. We introduce a family of heuristic cuts based on the concept of 'adjacent beams' and a beam elimination scheme based on the contribution of each beam to deliver the dose to the tumor in the ideal plan in which all potential beams can be used simultaneously. We show the effectiveness of these heuristics for intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) on a clinical liver case.

  10. Effects of heavy-ion beams on chromosomes of common wheat, Triticum aestivum

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Shinji; Saito, Yoshinaka [Laboratory of Plant Genetics and Breeding Science, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553 (Japan); Ryuto, Hiromichi; Fukunishi, Nobuhisa; Abe, Tomoko [RIKEN Nishina Center, RIKEN, Hirosawa, Wako 351-0198 (Japan); Tanaka, Hiroyuki [Laboratory of Plant Genetics and Breeding Science, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553 (Japan); Tsujimoto, Hisashi, E-mail: tsujim@muses.tottori-u.ac.jp [Laboratory of Plant Genetics and Breeding Science, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553 (Japan)

    2009-10-02

    To investigate the nature of plant chromosomes irradiated by heavy-ion beams, the effects of nitrogen (N) and neon (Ne) ion beams on hexaploid wheat chromosomes were compared with those of X-ray. Chromosome aberrations, such as short, ring and dicentric chromosomes appeared in high frequency. The average numbers of chromosome breaks at LD-50 by irradiation with X-ray, N and Ne ion beams were 32, 20 and 20, respectively. These values may be underestimated because chromosome rearrangement without change in chromosome morphology was not counted. Thus, we subsequently used a wheat line with a pair of extra chromosomes from an alien species (Leymus racemosus) and observed the fate of the irradiated marker chromosomes by genomic in situ hybridization. This analysis revealed that 50 Gy of neon beam induced about eight times more breaks than those induced by X-ray. This result suggests that heavy-ion beams induce chromosome rearrangement in high frequency rather than loss of gene function. This suggests further that most of the novel mutations produced by ion beam irradiation, which have been used in plant breeding, may not be caused by ordinary gene disruption but by chromosome rearrangements.

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

    International Nuclear Information System (INIS)

    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 ∼ 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

  12. Beam-beam effects in different luminosity levelling scenarios for the LHC

    CERN Document Server

    Buffat, X; Coombs, G R; Herr, W; Pieloni, T

    2014-01-01

    Adjusting luminosity and optimizing the luminous region in each interaction point of the LHC according to the experiments needs has become a requirement to maximize the efficiency of the different detectors. Several techniques are envisaged, most importantly by varying β∗ or a transverse offset at the interaction point. Coherent and incoherent stability in the presence of beam-beam effects will be discussed in realistic luminosity levelling scenarios for the LHC.

  13. Laser-induced retinal damage thresholds for annular retinal beam profiles

    Science.gov (United States)

    Kennedy, Paul K.; Zuclich, Joseph A.; Lund, David J.; Edsall, Peter R.; Till, Stephen; Stuck, Bruce E.; Hollins, Richard C.

    2004-07-01

    The dependence of retinal damage thresholds on laser spot size, for annular retinal beam profiles, was measured in vivo for 3 μs, 590 nm pulses from a flashlamp-pumped dye laser. Minimum Visible Lesion (MVL)ED50 thresholds in rhesus were measured for annular retinal beam profiles covering 5, 10, and 20 mrad of visual field; which correspond to outer beam diameters of roughly 70, 160, and 300 μm, respectively, on the primate retina. Annular beam profiles at the retinal plane were achieved using a telescopic imaging system, with the focal properties of the eye represented as an equivalent thin lens, and all annular beam profiles had a 37% central obscuration. As a check on experimental data, theoretical MVL-ED50 thresholds for annular beam exposures were calculated using the Thompson-Gerstman granular model of laser-induced thermal damage to the retina. Threshold calculations were performed for the three experimental beam diameters and for an intermediate case with an outer beam diameter of 230 μm. Results indicate that the threshold vs. spot size trends, for annular beams, are similar to the trends for top hat beams determined in a previous study; i.e., the threshold dose varies with the retinal image area for larger image sizes. The model correctly predicts the threshold vs. spot size trends seen in the biological data, for both annular and top hat retinal beam profiles.

  14. On Beaming Effects in Afterglow Light Curves

    OpenAIRE

    Moderski, R.; Sikora, M.; Bulik, T.

    1999-01-01

    The most luminous GRBs can be explained in terms of models involving stellar mass central engines only if the ejecta are beamed. As was pointed out by Rhoads, the dynamics of the blast wave, formed by the beamed ejecta sweeping the external gas, can be significantly modified by the sideways expansion. This is because in this case the surface of the blast wave increases faster than just due to the radial divergence and so the blast wave deceleration rate increases faster. According to analytic...

  15. Lateral resolution in focused electron beam-induced deposition: scaling laws for pulsed and static exposure

    International Nuclear Information System (INIS)

    In this work, we review the single-adsorbate time-dependent continuum model for focused electron beam-induced deposition (FEBID). The differential equation for the adsorption rate will be expressed by dimensionless parameters describing the contributions of adsorption, desorption, dissociation, and the surface diffusion of the precursor adsorbates. The contributions are individually presented in order to elucidate their influence during variations in the electron beam exposure time. The findings are condensed into three new scaling laws for pulsed exposure FEBID (or FEB-induced etching) relating the lateral resolution of deposits or etch pits to surface diffusion and electron beam exposure dwell time for a given adsorbate depletion state. (orig.)

  16. Observation Of Electron-beam-induced Phase Evolution Mimicking The Effect Of Charge-discharge Cycle In Li-rich Layered Cathode Materials Used For Li-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Ping; Yan, Pengfei; Romero, Eric; Spoerke, Erik D.; Zhang, Jiguang; Wang, Chong M.

    2015-02-24

    Capacity loss, and voltage fade upon electrochemical charge-discharge cycling observed in lithium-rich layered cathode oxides (Li[LixMnyTM1-x-y]O2 , TM = Ni, Co or Fe) have recently been identified to be correlated to the gradual phase transformation, featuring the formation of a surface reconstructed layer (SRL) that evolves from a thin (<2 nm), defect spinel layer upon the first charge, to a relatively thick (~5 nm), spinel or rock-salt layer upon continuous charge-discharge cycling. Here we report observations of a SRL and structural evolution of the SRL on the Li[Li0.2Ni0.2Mn0.6]O2 (LMR) particles, which are identical to those reported due to the charge-discharge cycle but are a result of electron-beam irradiation during scanning transmission electron microscopy (STEM) imaging. Sensitivity of the lithium-rich layered oxides to high-energy electrons leads to the formation of thin, defect spinel layer on surfaces of the particles when exposed to a 200 kV electron beam for as little as 30 seconds under normal high-resolution STEM imaging conditions. Further electron irradiation produces a thicker layer of the spinel phase, ultimately producing a rock-salt layer at a higher electron exposure. Atomic-scale chemical mapping by energy dispersive X-ray spectroscopy in STEM indicates the electron-beam-induced SRL formation on LMR is accomplished by migration of the transition metal ions to the Li sites without breaking down the lattice. This study provides an insight for understanding the mechanism of forming the SRL and also possibly a mean to study structural evolution in the Li-rich layered oxides without involving the electrochemistry.

  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. Azimuthal multiple-beam interference effects with combinations of vortex beams.

    Science.gov (United States)

    Moreno, Ignacio; Davis, Jeffrey A; Womble-Dahl, Taylor; Cottrell, Don M

    2015-05-15

    We create a series of vortex beams consisting of positive and negative topological charges and develop a geometry where they interfere creating azimuthal multiple-beam interference effects. Usually the combination of two beams with opposite charges creates an azimuthal two-beam interference effect where the intensity varies sinusoidally with azimuthal angle. We combine several of these beams to create patterns where the interference becomes more sharply defined in the azimuthal direction and where destructive interference eliminates some of the intensity peaks. The process is complicated by the fact that the radii of the different vortex beams depend on the topological charge and the focal length of the Fourier lens. We generate a series of patterns where the different charges are focused with different focal lengths such that their radii agree. However to encode these, we encode patterns from the lower charges that have been Fresnel diffracted to the plane of the highest charge. These complicated patterns are encoded onto a liquid crystal display (LCD). Experimental results agree well with theory. PMID:26393734

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

    Science.gov (United States)

    Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.

    2016-08-01

    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 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.

  20. On the Beam Induced Quasi-instability Transformation of the Damped Aperiodic Mode in the Intergalactic Medium

    Science.gov (United States)

    Kolberg, U.; Schlickeiser, R.; Yoon, P. H.

    2016-02-01

    Highly relativistic electron-positron pair beams considerably affect the spontaneously emitted field fluctuations in the unmagnetized intergalactic medium (IGM). In view of the considered small density ratio of beam and background plasma, a perturbative treatment is employed in order to derive the spectral balance equations for the fluctuating fields from first principles of plasma kinetic theory that are covariantly correct within the limits of special relativity. They self-consistently account for the competing effects of spontaneous and induced emission and absorption in the perturbed thermal plasma. It is found that the presence of the beam transforms the growth rate of the dominating transverse damped aperiodic mode into an effective growth rate that displays positive values in certain spectral regions if beam velocity and wave vector are perpendicular or almost perpendicular to each other. This corresponds to a quasi-instability that induces an amplification of the fluctuations for these wavenumbers. Such an effect can greatly influence the cosmic magnetogenesis as it affects the strengths of the spontaneously emitted magnetic seed fields in the IGM, thereby possibly lowering the required growth time and effectivity of any further amplification mechanism such as an astrophysical dynamo.

  1. Induced Optical Losses in Optoelectronic Devices due to Focused Ion Beam Damages

    CERN Document Server

    Vallini, Felipe; Reis, Elohim Fonseca dos; von Zuben, Antônio Augusto; Frateschi, Newton Cesário

    2012-01-01

    A study of damages caused by gallium focused ion beam (FIB) into III-V compounds is presented. Potential damages caused by local heating, ion implantation, and selective sputtering are presented. Preliminary analysis shows that local heating is negligible. Gallium implantation is shown to occur over areas tens of nanometers thick. Gallium accumulation as well as selective sputtering during III-V compounds milling is expected. Particularly, for GaAs, this effect leads to gallium segregation and formation of metallic clusters. Microdisk resonators were fabricated using FIB milling with different emission currents to analyze these effects on a device. It is shown that for higher emission current, thus higher implantation doses, the cavity quality factor rapidly decreases due to optical scattering losses induced by implanted gallium atoms.

  2. Acetone and the precursor ligand acetylacetone : distinctly different electron beam induced decomposition?

    NARCIS (Netherlands)

    Warneke, Jonas; Van Dorp, Willem F.; Rudolf, Petra; Stano, Michal; Papp, Peter; Matejcik, Stefan; Borrmann, Tobias; Swiderek, Petra

    2015-01-01

    In focused electron beam induced deposition (FEBID) acetylacetone plays a role as a ligand in metal acetylacetonate complexes. As part of a larger effort to understand the chemical processes in FEBID, the electron-induced reactions of acetylacetone were studied both in condensed layers and in the ga

  3. Studies on biological effects of ion beams on lethality, molecular nature of mutation, mutation rate, and spectrum of mutation phenotype for mutation breeding in higher plants

    International Nuclear Information System (INIS)

    Recently, heavy ions or ion beams have been used to generate new mutants or varieties, especially in higher plants. It has been found that ion beams show high relative biological effectiveness (RBE) of growth inhibition, lethality, and so on, but the characteristics of ion beams on mutation have not been clearly elucidated. To understand the effect of ion beams on mutation induction, mutation rates were investigated using visible known Arabidopsis mutant phenotypes, indicating that mutation frequencies induced by carbon ions were 20-fold higher than by electrons. In chrysanthemum and carnation, flower-color and flower-form mutants, which are hardly produced by gamma rays or X rays, were induced by ion beams. Novel mutants and their responsible genes, such as UV-B resistant, serrated petals and sepals, anthocyaninless, etc. were induced by ion beams. These results indicated that the characteristics of ion beams for mutation induction are high mutation frequency and broad mutation spectrum and therefore, efficient induction of novel mutants. On the other hand, PCR and sequencing analyses showed that half of all mutants induced by ion beams possessed large DNA alterations, while the rest had point-like mutations. Both mutations induced by ion beams had a common feature that deletion of several bases were predominantly induced. It is plausible that ion beams induce a limited amount of large and irreparable DNA damage, resulting in production of a null mutation that shows a new mutant phenotype. (author)

  4. Effects of beam-driven poloidal rotation on the neoclassical bootstrap current

    International Nuclear Information System (INIS)

    Unbalanced neutral beam injection drives toroidal and poloidal rotations in a tokamak plasma. The beam toroidal momentum input drives the toroidal rotation, and the parallel friction between the thermal ions and fast ions induces the poloidal rotation. A theory of the beam-driven poloidal rotation and its effects on energy transport was given recently by Hinton and Kim. In this work, we extend their considerations to the effects on the neoclassical bootstrap current. For parameters of interest in present neutral beam heated tokamaks, the magnitude of the beam-driven poloidal rotation can be significantly larger than that of the standard neoclassical value due to the ion temperature gradient. The presence of this driven poloidal rotation will manifest itself in modification of the neoclassical bootstrap current. In the case of coinjection, the driven poloidal rotation is in the opposite direction to the rotation driven by the temperature gradient, therefore it enhances the bootstrap current. In comparison with the standard theoretical predictions of the neutral beam-driven current, that enhancement in the bootstrap current varies with the beam and plasma parameters. A calculation of the parallel transport coefficients associated with the driven poloidal flow in finite-aspect ratio tokamaks will be presented. Experimental conditions for observing the enhancement in bootstrap current will be discussed

  5. Metal surface temperature induced by moving laser beams

    NARCIS (Netherlands)

    Römer, G.R.B.E.; Meijer, J.

    1995-01-01

    Whenever a metal is irradiated with a laser beam, electromagnetic energy is transformed into heat in a thin surface layer. The maximum surface temperature is the most important quantity which determines the processing result. Expressions for this maximum temperature are provided by the literature fo

  6. Beam induced deposition of platinum using a helium ion microscope

    NARCIS (Netherlands)

    Sanford, C.A.; Stern, L.; Barriss, L.; Farkas, L.; DiManna, M.; Mello, R.; Maas, D.J.; Alkemade, P.F.A.

    2009-01-01

    Helium ion microscopy is now a demonstrated practical technology that possesses the resolution and beam currents necessary to perform nanofabrication tasks, such as circuit edit applications. Due to helium’s electrical properties and sample interaction characteristics relative to gallium, it is like

  7. Beam induced deposition of platinum using a helium ion microscope

    NARCIS (Netherlands)

    Sanford, C.A.; Stern, L.; Barriss, L.; Farkas, L.; DiManna, M.; Mello, R.; Maas, D.J.; Alkemade, P.F.A.

    2009-01-01

    Helium ion microscopy is now a demonstrated practical technology that possesses the resolution and beam currents necessary to perform nanofabrication tasks, such as circuit edit applications. Due to helium's electrical properties and sample interaction characteristics relative to gallium, it is like

  8. Incoherent beam-beam effect---The relationship between tune-shift, bunch length and dynamic aperture

    International Nuclear Information System (INIS)

    Simulation studies of the influence of long bunches on the beam-beam effect in particle colliders suggest that, despite the risk from synchro-betatron resonances, the attainable luminosity may be greater than that obtained for short bunches

  9. Locally Resonant Gaps of Phononic Beams Induced by Periodic Arrays of Resonant Shunts

    Institute of Scientific and Technical Information of China (English)

    CHEN Sheng-Bing; WEN Ji-Hong; WANG Gang; HAN Xiao-Yun; WEN Xi-Sen

    2011-01-01

    @@ Periodic arrays of shunted piezoelectric patches are employed to control the propagation of elastic waves in phononic beams.Each piezo-patch is connected to a single resistance-inductance-capacitance shunting circuit.Therefore,the resonances of the shunting circuits will produce locally resonant gaps in the phononic beam.However,the existence of locally resonant gaps induced by resonant shunts has not been clearly proved by experiment so far.In this work,the locally resonant gap in a piezo-shunted phononic beam is investigated theoretically and verified by experiment.The results prove that resonances of shunting circuits can produce locally resonant gaps in phononic beams.%Periodic arrays of shunted piezoelectric patches are employed to control the propagation of elastic waves in phononic beams. Each piezo-patch is connected to a single resistance-inductance-capacitance shunting circuit. Therefore, the resonances of the shunting circuits will produce locally resonant gaps in the phononic beam. However, the existence of locally resonant gaps induced by resonant shunts has not been clearly proved by experiment so far. In this work, the locally resonant gap in a piezo-shunted phononic beam is investigated theoretically and verified by experiment. The results prove that resonances of shunting circuits can produce locally resonant gaps in phononic beams.

  10. Studies of the effects of electron cloud formation on beam dynamics at CesrTA

    International Nuclear Information System (INIS)

    The Cornell Electron Storage Ring Test Accelerator (CesrTA) has commenced operation as a linear collider damping ring test bed following its conversion from an e+e--collider in 2008. A core component of the research program is the measurement of effects of synchrotron-radiation-induced electron cloud formation on beam dynamics. We have studied the interaction of the beam with the cloud with measurements of coherent tune shifts and emittance growth in various bunch train configurations, bunch currents, beam energies, and bunch lengths, for both e+ and e- beams. This paper compares a subset of these measurements to modeling results from the two-dimensional cloud simulation packages ECLOUD and POSINST. These codes each model most of the tune shift measurements with remarkable accuracy, while some comparisons merit further investigation.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bouchard, Hugo, E-mail: hugo.bouchard@npl.co.uk; Duane, Simon [Acoustics and Ionising Radiation Team, National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Kamio, Yuji [Centre hospitalier de l’Université de Montréal (CHUM), 1560 Sherbrooke Est, Montréal, Québec H2L 4M1 (Canada); Palmans, Hugo [Acoustics and Ionising Radiation Team, National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Medical Physics, EBG MedAustron GmbH, Wiener Neustadt A-2700 (Austria); Seuntjens, Jan [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4 (Canada)

    2015-10-15

    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.

  13. Electron beam irradiation induces abnormal development and the stabilization of p53 protein of American serpentine leafminer, Liriomyza trifolii (Burgess)

    Science.gov (United States)

    Koo, Hyun-Na; Yun, Seung-Hwan; Yoon, Changmann; Kim, Gil-Hah

    2012-01-01

    The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests worldwide. In this study, we determined electron beam doses for inhibition of normal development of the leaf miner and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs (0-24 h old), larvae (2nd instar), puparia (0-24 h old after pupariation) and adults (24 h after emergence) were irradiated with increasing doses of electron beam irradiation (six levels between 30 and 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and puparia was lower than in the untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein within 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for female sterilization of L. trifolii.

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

    International Nuclear Information System (INIS)

    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

  15. Functional nickel-based deposits synthesized by focused beam induced processing

    Science.gov (United States)

    Córdoba, R.; Barcones, B.; Roelfsema, E.; Verheijen, M. A.; Mulders, J. J. L.; Trompenaars, P. H. F.; Koopmans, B.

    2016-02-01

    Functional nanostructures fabricated by focused electron/ion beam induced processing (FEBIP/FIBIP) open a promising route for applications in nanoelectronics. Such developments rely on the exploration of new advanced materials. We report here the successful fabrication of nickel-based deposits by FEBIP/FIBIP using bis(methyl cyclopentadienyl)nickel as a precursor. In particular, binary compounds such as nickel oxide (NiO) are synthesized by using an in situ two-step process at room temperature. By this method, as-grown Ni deposits transform into homogeneous NiO deposits using focused electron beam irradiation under O2 flux. This procedure is effective in producing highly pure NiO deposits with resistivity of 2000 Ωcm and a polycrystalline structure with face-centred cubic lattice and grains of 5 nm. We demonstrate that systems based on NiO deposits displaying resistance switching and an exchange-bias effect could be grown by FEBIP using optimized parameters. Our results provide a breakthrough towards using these techniques for the fabrication of functional nanodevices.

  16. Vibration Analysis of Nano-Beam with Consideration of Surface Effects and Damage Effects

    Science.gov (United States)

    Yin, Fan; Chen, Chang Ping; Chen, De Liang

    2015-03-01

    On the basis of Euler-Bernoulli beam theory, surface elastic theory, the strain equivalent assumption and modiffed couple stress theory, the nonlinear governing equations of the nano-beam are derived. In addition, the Galerkin method and the Harmonic Balance Method are adopted so as to give a solution to the equations. In the example, the effects of nano-beam length, nano-beam thickness, damage factor and surface efect to curves of amplitude-frequency response of the nano-beam are discussed. The results show that damage effects should be taken into consideration and the frequency can be controlled by load and structure size of nano-beam.

  17. Simulating Electron Cloud Effects in Heavy-Ion Beams

    International Nuclear Information System (INIS)

    Stray electrons can be introduced in heavy ion fusion accelerators as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. We summarize here results from several studies of electron-cloud accumulation and effects: (1) Calculation of the electron cloud produced by electron desorption from computed beam ion loss; the importance of ion scattering is shown; (2) Simulation of the effect of specified electron cloud distributions on ion beam dynamics. We find electron cloud variations that are resonant with the breathing mode of the beam have the biggest impact on the beam (larger than other resonant and random variations), and that the ion beam is surprisingly robust, with an electron density several percent of the beam density required to produce significant beam degradation in a 200-quadrupole system. We identify a possible instability associated with desorption and resonance with the breathing mode. (3) Preliminary investigations of a long-timestep algorithm for electron dynamics in arbitrary magnetic fields

  18. The effect of laser beam size in a zig-zag collimator on transverse cooling of a krypton atomic beam

    Indian Academy of Sciences (India)

    Vivek Singh; V B Tiwari; S Singh; S R Mishra; H S Rawat

    2014-07-01

    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 beam, significantly reduces the value of transverse velocity capture range of the collimator. The experimental observations show the trend similar to that obtained from simulations. Our study can be particularly useful where a small zig-zag collimator is required.

  19. Electron-beam-induced dislocations in GaAs and InP single crystals

    International Nuclear Information System (INIS)

    Dislocations have been induced in GaAs and InP single crystals by the electron beam exposure in a scanning electron microscope, with neither a mechanical bending nor a special pretreatment of the specimens. The generation and movement of the dislocations were not dependent upon the electron beam energy, crystal orientation, dopant nature, or doping level, but only on the electron beam current; a beam current of (1--2)x10-6 A was found to be the threshold for the dislocation release. By increasing the beam current up to 5x10-6 A, As or P losses from the specimen surface have been evidenced. In GaAs (001)-oriented crystals, the dislocations were found to be of pure edge type with the Burgers vector normal to the sample surface. A climb process, involving As or P vacancy migration, has been assumed to be the physical mechanism responsible for the dislocation origin

  20. Study of micro-dosimeter P-N junctions using ion beam induced charge

    International Nuclear Information System (INIS)

    Reversed bias p-n junction offered an excellent opportunity to understand the radiobiological effects of Boron Neutron Capture Therapy (BNCT) in tissues and carcinoma cells. Ionizing radiation creates electron hole pairs in semiconducting materials. Under an electric field the charge carriers can be tapped externally to produce charge pulses. Therefore the junction can serve as a micro-dosimeter for the detection of charged particles such as lithium and helium ions produced as a by-product of neutron capture by the boron and nitrogen nuclei respectively. By arranging the reverse biased p-n junctions into a two dimensional array, it offers the possibility of measuring the energy deposition pattern. In this paper, we have used the Ion Beam Induced Charge (IBIC) with a scanned MeV ion microbeam to image and characterise the array of p-n junctions (authors)

  1. Time Resolved Ion Beam Induced Current measurements on MOS capacitors using a cyclotron microbeam

    International Nuclear Information System (INIS)

    As overlayers on electronic devices become progressively thicker, radiation effects microscopy using traditional microbeams (with ion energies up to a few tens of MeVs) is becoming less and less viable. To penetrate to the sensitive regions of these devices, much higher energies, several hundreds of MeVs are necessary. These high energies are available only from cyclotrons. A nuclear microprobe has been developed on the AVF cyclotron of the Takasaki Ion Accelerators for Advanced Radiation Applications (TIARA) facility. In this paper we will present the first results using 260 MeV Ne and 520 MeV Ar microbeams to perform Time Resolved Ion Beam Induced Current (TRIBIC) measurements on Metal-Oxide-Semiconductor (MOS) capacitors. The results will be compared to data taken with a traditional 15 MeV O microbeam.

  2. 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...

  3. 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.

  4. Shaped E-beam nanopatterning with proximity effect correction

    Czech Academy of Sciences Publication Activity Database

    Urbánek, Michal; Kolařík, Vladimír; Matějka, Milan; Matějka, František; Bok, Jan; Mikšík, P.; Vašina, J.

    Ostrava: TANGER Ltd, 2012, s. 717-722. ISBN 978-80-87294-32-1. [NANOCON 2012. International Conference /4./. Brno (CZ), 23.10.2012-25.10.2012] R&D Projects: GA MPO FR-TI1/576; GA MŠk ED0017/01/01; GA TA ČR TE01020233 Institutional support: RVO:68081731 Keywords : e-beam writer * shaped beam * proximity effect correction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  5. Feshbach-resonance-induced atomic filamentation and quantum pair correlation in atom-laser-beam propagation

    OpenAIRE

    Zhang, Weiping; Search, Chris P.; Pu, Han; Meystre, Pierre; Wright, Ewan M.

    2002-01-01

    We study the propagation of an atom laser beam through a spatial region with a magnetic field tuned to a Feshbach resonance. Tuning the magnetic field below the resonance produces an effective focusing Kerr medium that causes a modulational instability of the atomic beam. Under appropriate circumstances, this results in beam breakup and filamentation seeded by quasi-particle fluctuations, and in the generation of correlated atomic pairs.

  6. Effect of diaphragms on electron beam stability in a linear induction accelerator

    International Nuclear Information System (INIS)

    In diaphragms used for protection of accelerating tube of a linear induction accelerator from electron impinge, the electron beam being translated as to the axis induces currents, partially compensating the effect of the induced charges. Therefore, one can expect that when selecting certain geometry of the diaphraqms the limitations for the accelerator parameters will be considerably reduced. The sequence of diaphragms however is the beam energy degrader, the interaction with it being able to cause the instability of the beam high-frequency oscillations. In the present work the effect of the beam electromagnetic field screening by means of the sequence of diaphragms on the stability of the beam transverse motion has been studied. It is shown, that the rise of transverse oscillations amplitude can be reduced at the expense of the increase of the channel radius and focusing field intensity, as well as the decrease of screening factor, which can be achieved by the increase of the structure period. It is also shown, that arrangement of the accelerator sections, when voltage, created by all inductors of sections, is applied to one accelerating gap, is more preferable

  7. Beam-beam effects in the high-pile-up tests of the LHC

    CERN Document Server

    Trad, G

    2014-01-01

    Investigating the beam-beam limit in the LHC is of great importance, since identifying its source is crucial for the luminosity optimization scenario. Several experiments were carried out to search for this limit and check whether it is dominated by the head-on (HO) or the long-range (LR) interactions. In this paper only the HO collision effects will be considered, tracking the evolution of the maximum tune shift achieved during the dedicated machine developments and the special high pile-up fills.

  8. Beam-beam effects in the high-pile-up tests of the LHC

    OpenAIRE

    Trad, G.

    2014-01-01

    Investigating the beam-beam limit in the LHC is of great importance, since identifying its source is crucial for the luminosity optimization scenario. Several experiments were carried out to search for this limit and check whether it is dominated by the head-on (HO) or the long-range (LR) interactions. In this paper only the HO collision effects will be considered, tracking the evolution of the maximum tune shift achieved during the dedicated machine developments and the special high pile-up ...

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

    International Nuclear Information System (INIS)

    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)

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

    Directory of Open Access Journals (Sweden)

    Napapat Amornwichet

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

  11. 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....

  12. Beam divergence effects on high power optical parametric oscillation

    Institute of Scientific and Technical Information of China (English)

    Li Hui-Qing; Geng Ai-Cong; Bo Yong; Wu Ling-An; Cui Da-Fu; Xu Zu-Yan

    2005-01-01

    The beam divergence effects of the input pump laser on a high power nanosecond optical parametric oscillator (OPO) have been numerically simulated. The OPO conversion efficiency is affected due to the angular deviation of real laser beams from ideal phase matching conditions. Our theoretical model is based on the decomposition of the Gaussian beam and assumes each component has a single deviation angle and thus a Particular wave vector mismatch. We take into account the variable intensity profile in the spatial and temporal domains of the Gaussian beam, the pump depletion effects for large-signal processes as well as the oscillatory effects of the three waves. Two nonlinear crystals β-BaB2O4 (BBO) and LiB3O5 (LBO) have been investigated in detail. The results indicate that the degree of beam divergence strongly influences the maximum pump intensity, optimum crystal length and OPO conversion efficiency.The impact of beam divergence is much more severe in the case of critical phase-matching for BBO than in the case of non-critical phase-matching for LBO. The results provide a way to choose the optimum parameters for a high power ns OPO such as the nonlinear material, the crystal length and the pump intensity, etc. Good agreement is obtained with our experimental results.

  13. Effects of beam velocity and density on an ion-beam pulse moving in magnetized plasmas

    CERN Document Server

    Zhao, Xiao-ying; Zhao, Yong-tao; Qi, Xin; Yang, Lei

    2016-01-01

    The wakefield and stopping power of an ion-beam pulse moving in magnetized plasmas are investigated by particle-in-cell (PIC) simulations. The effects of beam velocity and density on the wake and stopping power are discussed. In the presence of magnetic field, it is found that beside the longitudinal conversed V-shaped wakes, the strong whistler wave are observed when low-density and low-velocity pulses moving in plasmas. The corresponding stopping powers are enhanced due to the drag of these whistler waves. As beam velocities increase, the whistler waves disappear, and only are conversed V-shape wakes observed. The corresponding stopping powers are reduced compared with these in isotropic plasmas. When high-density pulses transport in the magnetized plasmas, the whistler waves are greatly inhibited for low-velocity pulses and disappear for high-velocity pulses. Additionally, the magnetic field reduces the stopping powers for all high-density cases.

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

    International Nuclear Information System (INIS)

    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.

  15. 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.

  16. Electron-cloud instabilities and beam-induced multipacting in the LHC and in the VLHC

    International Nuclear Information System (INIS)

    In the beam pipe of the Large Hadron Collider (LHC), photoemission and secondary emission give rise to a quasi-stationary electron cloud, which is established after a few buncn passages. The response of this electron cloud to a transversely displaced bunch resembles a short-range wakefield and can cause a fast instability. In additoin, beam-induced multipacting of the electrons may lead to an enhanced gas desorption and an associated pressure increase. In this paper the authors report preliminary simulation results of the electron-cloud build-up both in a dipole magnet and in a straight section of the LHC at top energy. The effective wakefield created by the electron cloud translates into an instability rise time of about 40 ms horizontally and 500 ms vertically. This rise time is not much larger than that of the resistive-wall instability at injection energy. Similar simulation studies show that the instability rise time for the proposed Very Large Hadron Collider (VLHC) is about 3--4 s in both trasnverse planes. The smaller growth rate in the VLHC, as compared with the LHC, is primarily due to the much lower bunch population

  17. Two-line-coupling beam-quality effects in stimulated Raman scattering

    International Nuclear Information System (INIS)

    The authors present the results of calculations of the beam quality obtainable in a collimated, single-beam Raman beam cleanup system, in which the pump laser contains two lines whose frequency separation is enough to cause significant dispersive ''slip'' between them in the Raman amplifier. A specific example is the 351-353 nm line pair of an XeF laser. They start from equations coupling the various modes of the lines and their corresponding Stokes modes. Refractivity effects caused by nonuniform Raman-induced population transfer are specifically accounted for. The impact on beam quality is assessed as a function of the pressure in a H/sub 2/ Raman amplifier, and it is shown that the minimum effect occurs at a pressure of 2.4 Atm, for which the motionally narrowed Raman linewidth takes its minimum value. The two-line coupling causes the population transfer due to the stronger of the two lines to adversely affect the beam quality of the weaker line. For an rms percent fluence modulation of 15 percent, the two-line coupling lowers the Strehl ratio (a measure of beam quality) by --15 percent for a 1-μs XeF laser pulse length

  18. Effect of energetic electron beam treatment on transparent conductive ZnO thin films

    International Nuclear Information System (INIS)

    Undoped and Al-doped ZnO thin films were prepared by a sol–gel spin coating method. The films were exposed to the electron beam at different energies to improve their electrical properties by modifying their film crystallinity. For both the undoped and Al-doped ZnO thin films, the carrier concentration significantly increased and the resistivity decreased after the introduction of the energetic electron beam. Since band gap widening of the undoped and Al-doped ZnO thin films was also observed with exposure to the electron beam, the behaviors and tendencies can be explained by the Burstein–Moss effect. The effects of the electron beam on ZnO thin film properties, including band gap widening, increasing carrier concentration, and significantly decreased resistivity, were similar to the effects of Al doping in ZnO. Finally, by combining electron beam treatment and Al doping of ZnO thin films prepared by a sol–gel method, the resistivity of the sol–gel synthesized ZnO thin film decreased from 5.8 × 102 Ω cm to 8.2 × 10−2 Ω cm. According to the Monte Carlo simulation of electron penetration in the ZnO thin film, the penetration depth increased with electron beam energy, which induced lattice heating and atomic rearrangement by electronic excitation in a collision cascade. - Highlights: • Electron beam treatment on ZnO thin films by sol–gel spin coating synthesis • Improvement of crystallinity and increase in the optical band gap energy • Decrease in the resistivity with the increase in the carrier concentration • Increase in the electron penetration depth with beam energy

  19. 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

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

    International Nuclear Information System (INIS)

    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 1015 ions/cm2. Electrical activation of implanted dopant B was also measured in the recrystallized Si layer. (author)

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

    Science.gov (United States)

    Basa, Adina; Thaulow, Christian; Barnoush, Afrooz

    2013-11-01

    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.

  2. Application of lateral photovoltage towards contactless light beam induced current measurements and its dependence on the finite beam size

    International Nuclear Information System (INIS)

    The nature of the signal due to light beam induced current (LBIC) at the remote contacts is verified as a lateral photovoltage for non-uniformly illuminated planar p-n junction devices; simulation and experimental results are presented. The limitations imposed by the ohmic contacts are successfully overcome by the introduction of capacitively coupled remote contacts, which yield similar results without any significant loss in the estimated material and device parameters. It is observed that the LBIC measurements introduce artefacts such as shift in peak position with increasing laser power. Simulation of LBIC signal as a function of characteristic length Lc of photo-generated carriers and for different beam diameters has resulted in the observed peak shifts, thus attributed to the finite size of the beam. Further, the idea of capacitively coupled contacts has been extended to contactless measurements using pressure contacts with an oxidized aluminium electrodes. This technique avoids the contagious sample processing steps, which may introduce unintentional defects and contaminants into the material and devices under observation. Thus, we present here, the remote contact LBIC as a practically non-destructive tool in the evaluation of device parameters and welcome its use during fabrication steps

  3. The transverse shift of a high order paraxial vortex-beam induced by a homogeneous anisotropic medium

    CERN Document Server

    Fadeyeva, T A; Volyar, A V

    2008-01-01

    We consider the propagation of a tilted high order paraxial vortex-beam through a homogeneous anisotropic medium of a uniaxial crystal. We found that the initially circularly polarized beam bearing the l-order optical vortex splits into ordinary and extraordinary beams with a complex vortex structure. After a series of dislocation reactions the vortices gather together at the axis of the partial beam with the initial circular polarization shaping the l-order optical vortex. However, only l-1 vortices gather together on the axis of the partial beam with the orthogonal circular polarization. One optical vortex is shifted along the direction perpendicular to the inclination plane of the beam. Such a vortex displacement induces the transverse shift of the partial beam. In fact, we deal with the beam quadrefringence in a uniaxial, homogeneous anisotropic medium. The first two beams is a result of the splitting of the initial tilted beam into the ordinary and extraordinary once.

  4. Gravitationally induced CP effects

    International Nuclear Information System (INIS)

    We study the gravitational analogues of CP violating effects in quantum chromodynamics. These arise through the addition to the action of terms THETA ∫Rsup(ab*)sub(μν)Rsup(μν)sub(ab) and THETA' ∫fsub(μν) *fsup(μν) where Rsup(ab)sub(μν) and fsub(μν) are respectively the curvature tensor and Maxwell field tensor. Both terms can be non-trivial in spacetimes with sufficiently complicated topology. The QCD plus QED plus QGD (quantum gravidynamics) contributions may be combined in a manner which leaves the QCD quark sector as before but the presence of massless neutrinos (or spin 3/2 gravitinos) removes the pure QGD CP violation. The dominant new effect thus arises in the charged leptonic sector from THETA' ∫fsub(μν)*fsup(μν) and is formally independent of the gravitational constant. (orig.)

  5. Ionization chamber gradient effects in nonstandard beam configurations

    International Nuclear Information System (INIS)

    Purpose: For the purpose of nonstandard beam reference dosimetry, the current concept of reporting absorbed dose at a point in water located at a representative position in the chamber volume is investigated in detail. As new nonstandard beam reference dosimetry protocols are under development, an evaluation of the role played by the definition of point of measurement could lead to conceptual improvements prior to establishing measurement procedures. Methods: The present study uses the current definition of reporting absorbed dose to calculate ionization chamber perturbation factors for two cylindrical chamber models (Exradin A12 and A14) using the Monte Carlo method. The EGSnrc based user-code EGS lowbar chamber is used to calculate chamber dose responses of 14 IMRT beams chosen to cause considerable dose gradients over the chamber volume as previously used by Bouchard and Seuntjens [''Ionization chamber-based reference dosimetry of intensity modulated radiation beams,'' Med. Phys. 31(9), 2454-5465 (2004)]. Results: The study shows conclusively the relative importance of each physical effect involved in the nonstandard beam correction factors of 14 IMRT beams. Of all correction factors involved in the dosimetry of the beams studied, the gradient perturbation correction factor has the highest magnitude, on average, 11% higher compared to reference conditions for the Exradin A12 chamber and about 5% higher for the Extradin A14 chamber. Other perturbation correction factors (i.e., Pwall, Pstem, and Pcel) are, on average, less than 0.8% different from reference conditions for the chambers and beams studied. The current approach of reporting measured absorbed dose at a point in water coinciding with the location of the centroid of the chamber is the main factor responsible for large correction factors in nonstandard beam deliveries (e.g., intensity modulated radiation therapy) reported in literature. Conclusions: To reduce or eliminate the magnitude of perturbation

  6. On Compensating Tune Spread Induced by Space Charge in Bunched Beams

    OpenAIRE

    Litvinenko, Vladimir N.; Wang, Gang

    2014-01-01

    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. 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. But all of these methods d...

  7. 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.

  8. The induced turbulence effect on propagation of radio emission in pulsar magnetospheres

    OpenAIRE

    Luo, Qinghuan; Melrose, D. B.

    2006-01-01

    The effect of photon-beam-induced turbulence on propagation of radio emission in a pulsar magnetosphere is discussed. Beamed radio emission with a high brightness temperature can generate low-frequency plasma waves in the pulsar magnetosphere and these waves scatter the radio beam. We consider this effect on propagation of radio emission both in the open field line region and in the closed field line region. The former is applicable to most cases of pulsar radio emission where the propagation...

  9. Beam Anisotropy Effect on Alfven Eigenmode Stability in ITER-like Plasma

    Energy Technology Data Exchange (ETDEWEB)

    N.N. Gorelenkov; H.L. Berk; R.V. Budny

    2004-08-18

    This work studies the stability of the toroidicity-induced Alfven Eigenmodes (TAE) in the proposed ITER burning plasma experiment, which can be driven unstable by two groups of energetic particles, the 3.5-MeV {alpha}-particle fusion products and the tangentially injected 1-MeV beam ions. Both species are super-Alfvenic but they have different pitch-angle distributions and the drive for the same pressure gradients is typically stronger from co-injected beam ions as compared with the isotropically distributed {alpha}-particles. This study includes the effect of anisotropy of the beam-ion distribution function on TAE growth rate directly via the additional velocity space drive and indirectly in terms of the enhanced effect of the resonant particle phase space density. For near parallel injection, TAEs are marginally unstable if the injection aims at the plasma center where the ion Landau damping is strong, whereas with the off-axis neutral-beam injection the instability is stronger with the growth rate near 0.5% of TAE mode frequency. In contrast, for perpendicular beam injection TAEs are predicted to be stabilized in nominal ITER discharges. In addition, the effect of TAEs on the fast-ion beta profiles is evaluated on the bases of a quasi-linear diffusion model which makes use of analytic expressions for the local growth and damping rates. These results illustrate the parameter window that is available for plasma burn when TAE modes are excited.

  10. Ion beam induced charge and cathodoluminescence imaging of response uniformity of CVD diamond radiation detectors

    CERN Document Server

    Sellin, P J; Galbiati, A; Maghrabi, M; Townsend, P D

    2002-01-01

    The uniformity of response of CVD diamond radiation detectors produced from high quality diamond film, with crystallite dimensions of >100 mu m, has been studied using ion beam induced charge imaging. A micron-resolution scanning alpha particle beam was used to produce maps of pulse height response across the device. The detectors were fabricated with a single-sided coplanar electrode geometry to maximise their sensitivity to the surface region of the diamond film where the diamond crystallites are highly ordered. High resolution ion beam induced charge images of single crystallites were acquired that demonstrate variations in intra-crystallite charge transport and the termination of charge transport at the crystallite boundaries. Cathodoluminescence imaging of the same crystallites shows an inverse correlation between the density of radiative centres and regions of good charge transport.

  11. Proton beam induced luminescence of silicon dioxide implanted with silicon

    International Nuclear Information System (INIS)

    Light emission from a silicon dioxide layer enriched with silicon has been studied. Samples used had structures made on thermally oxidized silicon substrate wafers. Excess silicon atoms were introduced into a 250-nm-thick silicon dioxide layer via implantation of 60 keV Si+ ions up to a fluence of 2 x 1017 cm-2. A 15-nm-thick Au layer was used as a top semitransparent electrode. Continuous blue light emission was observed under DC polarization of the structure at 8-12 MV/cm. The blue light emission from the structures was also observed in an ionoluminescence experiment, in which the light emission was caused by irradiation with a H2+ ion beam of energy between 22 and 100 keV. In the case of H2+, on entering the material the ions dissociated into two protons, each carrying on average half of the incident ion energy. The spectra of the emitted light and the dependence of ionoluminescence on proton energy were analyzed and the results were correlated with the concentration profile of implanted silicon atoms.

  12. Proton beam induced luminescence of silicon dioxide implanted with silicon

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, Grzegorz [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warszawa (Poland)], E-mail: grzegorz.gawlik@itme.edu.pl; Jagielski, Jacek [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warszawa (Poland); Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock/Swierk (Poland); Stonert, Anna; Ratajczak, Renata [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock/Swierk (Poland)

    2009-08-15

    Light emission from a silicon dioxide layer enriched with silicon has been studied. Samples used had structures made on thermally oxidized silicon substrate wafers. Excess silicon atoms were introduced into a 250-nm-thick silicon dioxide layer via implantation of 60 keV Si{sup +} ions up to a fluence of 2 x 10{sup 17} cm{sup -2}. A 15-nm-thick Au layer was used as a top semitransparent electrode. Continuous blue light emission was observed under DC polarization of the structure at 8-12 MV/cm. The blue light emission from the structures was also observed in an ionoluminescence experiment, in which the light emission was caused by irradiation with a H{sub 2}{sup +} ion beam of energy between 22 and 100 keV. In the case of H{sub 2}{sup +}, on entering the material the ions dissociated into two protons, each carrying on average half of the incident ion energy. The spectra of the emitted light and the dependence of ionoluminescence on proton energy were analyzed and the results were correlated with the concentration profile of implanted silicon atoms.

  13. Study on isoenzymes and SDS-PAGE of the electron beam induced mutant of gladiolus 'Beauty Queen'

    International Nuclear Information System (INIS)

    In order to test the feasibility of electron beam induced mutation on Gladiolus and the effects of various doses of electron beam on flower traits, the corms of gladiolus 'Beauty Queen' were irradiated by electron beam with different doses. Flower-colour and inflorescence mutants (M1' and M2')were obtained, respectively at the doses of 40 Gy and l60 Gy. The two mutants and the parent (CK) and those irradiated with same doses (40 Gy and 160 Gy) were studied. The isozymes of POD, CAT, AMY and EST were tested, it shows that isozymes patterns of gladiolus irradiated at the doses of 40 Gy and 160 Gy a similar to CK, but the mutants' bands were added or absent compared to CK. Based on band types of isozymes, the cluster analysis was carried out and dendrogram generated using SPSS software version 11.5, it indicates that they may be divided into three groups: CK group (CK, gladiolus irradiated at the doses of 40 Gy and 160 Gy), M1' group and M2' group. The bands of protein subunit were analyzed by SDS- PAGE, it shows protein expression is obviously inhibited by electron beam irradiation. But three different protein bands were found in the two mutants, and their molecular weights were 96 kDa, 115.4 kDa, 137.2 kDa, respectively. These special proteins may have relation with regulation and control flower-color and inflorescence. The results indicate that electron beam irradiation is an effective way for inducing flower-color and flower-shape mutants. (authors)

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

    International Nuclear Information System (INIS)

    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 (Ta, associated with the glass transition temperature Tg) over a broad range of conversion (p) and reveal a peculiar behavior at high conversion. In this domain (p > 0.90), the material's Tg 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 Tg, 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

  15. Moessbauer Effect applications using intense radioactive ion beams

    International Nuclear Information System (INIS)

    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

  16. 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)

  17. Experimental study of electron beam induced removal of H/sub 2/S from geothermal fluids

    Energy Technology Data Exchange (ETDEWEB)

    Helfritch, D.J.; Singhvi, R.; Evans, R.D.; Reynolds, W.E.

    1983-09-01

    The treatment of geothermal steam by electron beam irradiation is a potential alternative method of H/sub 2/S removal which can be applied upstream or downstream and has no chemical requirements. The experimental work reported here examines the effectiveness of electron beam treatment of geothermal fluids. These fluids are produced by combining the constituents in a heated cell, which contains an electron beam transparent window. Irradiation of the contents and subsequent chemical analysis allows an evaluation of effectiveness. These results are used for a commercial feasibility assessment.

  18. 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

    Industrial x-ray computed tomography (CT) systems are being increasingly used as dimensional measuring machines. However, micron level accuracy is not always achievable, as of yet. The measurement accuracy is influenced by many factors, such as the workpiece properties, x-ray voltage, filter, beam...... the surrounding stepped cylinder. Accuracy as well as the effect on the uncertainty determination is discussed. The results are compared with simulations using monochromatic beams in order to have a benchmark which excludes beam hardening effects and x-ray scattering. Furthermore, based on the above...

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

    International Nuclear Information System (INIS)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Gostishchev, Vitaly

    2008-06-15

    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.)

  1. Lethal and mutagenic effects of ion beams and γ-rays in Aspergillus oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Toyoshima, Yoshiyuki, E-mail: toyoshima@yamasa.com [Soy Sauce Laboratory, Yamasa Corporation, 2-10-1 Araoicho, Choshi, Chiba 288-0056 (Japan); Takahashi, Akemi; Tanaka, Hisaki; Watanabe, Jun; Mogi, Yoshinobu; Yamazaki, Tatsuo [Soy Sauce Laboratory, Yamasa Corporation, 2-10-1 Araoicho, Choshi, Chiba 288-0056 (Japan); Hamada, Ryoko; Iwashita, Kazuhiro [Fundamental Research Division, National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashihiroshima, Hiroshima 739-0046 (Japan); Satoh, Katsuya; Narumi, Issay [Ion Beam Mutagenesis Research Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2012-12-15

    Highlights: ► We investigated the effects of different LET radiation in A. oryzae. ► Both γ-rays and ion beams induced base substitutions, frameshifts, deletions. ► Both γ-rays and ion beams induced genome-wide large-scale mutations in A. oryzae. ► Some differences in the types and frequencies of mutations were found. ► Our results provide new basic insights into the mutation breeding of A. oryzae. - Abstract: Aspergillus oryzae is a fungus that is used widely in traditional Japanese fermentation industries. In this study, the lethal and mutagenic effects of different linear energy transfer (LET) radiation in freeze-dried conidia of A. oryzae were investigated. The lethal effect, which was evaluated by a 90% lethal dose, was dependent on the LET value of the ionizing radiation. The most lethal ionizing radiation among that tested was {sup 12}C{sup 5+} ion beams with an LET of 121 keV/μm. The {sup 12}C{sup 5+} ion beams had a 3.6-times higher lethal effect than low-LET (0.2 keV/μm) γ-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. {sup 12}C{sup 6+} ion beams with an LET of 86 keV/μm were the most effective in inducing selenate resistance. The mutant frequency following exposure to {sup 12}C{sup 6+} ion beams increased with an increase in dose and reached 3.47 × 10{sup −3} at 700 Gy. In the dose range from 0 to 700 Gy, {sup 12}C{sup 5+} ion beams were the second most effective in inducing selenate resistance, the mutant frequency of which reached a maximum peak (1.67 × 10{sup −3}) at 400 Gy. To elucidate the characteristics of mutation induced by ionizing radiation, mutations in the sulphate permease gene (sB) and ATP sulfurylase gene (sC) loci, the loss of function of which results in a selenate resistant phenotype, were compared between {sup 12}C{sup 5+} ion beams and γ-rays. We detected all types of transversions and transitions. For frameshifts, the frequency of a +1 frameshift was the highest in all

  2. Effect of electron beam radiations on anxiety in experimental animal models

    International Nuclear Information System (INIS)

    Exposures to ionizing radiation have been an inevitable part of the environment. This type of radiation can disrupt atoms, creating positive and negative charged particles, and cause biological harm. Ionizing radiation includes X-rays, gamma rays, alpha particles, beta particles and neutrons. They have the potential to cause both beneficial and harmful effects. There are concerns about these radiations as they are widely used in hospitals for treatment and diagnosis of various diseases. The present work was designed to test the effect of whole body electron beam radiation on anxiety in mice using the Elevated plus maze and Light dark arena, the commonly used models for assessing anxiety in rodents. Mice were irradiated with three different doses (2 Gy, 4 Gy and 6 Gy) of electron beam radiations. Statistical analysis revealed that whole body irradiation of the moderate dose range (2-6 Gy) of electron beam leads to a significant (p<0.001) anxiogenic activity in irradiated mice. Electron beam induced anxiety can be due to radiation induced reactive oxygen species in brain. (author)

  3. Micro-vibrating spatial filters-induced beam positioning stability in large laser system

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Jianqiang Zhu; Jia Xu; Quanyuan Shan; Kun Xiao; Xuejie Zhang

    2012-01-01

    A dynamic beam propagation model of micro-vibrating spatial filters in inertial confinement fusion (ICF) facilities is built based on the additional beam in SG-Ⅱ facility.The transfer matrix is then deduced,and the sensitivities of the beam positioning to the pellet in the target area to the vibrations of every spatial filter are analyzed,which indicates that the vibrations of spatial filters in the pre-amplify zone has less effects on beam positioning stability at the target.In addition,the vibrations of spatial filters in the main amplify zone dominates the beam positioning stability of the target,especially the vibration of the spatial filter SF7.

  4. Relaxation of Blazar Induced Pair Beams in Cosmic Voids: Measurement of Magnetic Field in Voids and Thermal History of the IGM

    CERN Document Server

    Miniati, Francesco

    2012-01-01

    The stability properties of a low density ultra relativistic pair beam produced in the intergalactic medium 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 affect considerably the thermal history of the intergalactic medium and structure formation. We use a Monte Carlo method to quantify the shower properties, in particular the bulk Lorentz factor and the angular spread of the beam, as a function of distance from the blazar. We find that the fastest growing modes, like any perturbation mode with even a very modest component perpendicular to the beam direction, requires a kinetic treatment. Combined with the effect of non-linear Landau damping, which suppresses the growth of plasma oscillations, the beam relaxation timescale is found typically longer than a Hubble time. Finally, density inhomogeneities associated with cosmic structure induce severe loss of ...

  5. Direct observation of electron-beam-induced densification and hardening of silica nanoballs by in situ transmission electron microscopy and finite element method simulations

    International Nuclear Information System (INIS)

    We report on the use of in situ transmission electron microscopy techniques and finite element method simulations to study the influence of electron beam irradiation on the deformation behavior and mechanical properties of nanoscale amorphous silica balls. We show that, on the nanometer scale, electron beam irradiation of silica results in athermal densification and simultaneous material hardening. It is demonstrated how the amount of densification can be controlled via the irradiation dose, using specific beam current densities inside a transmission electron microscope. The electron-beam-induced densification is interpreted as the direct reason for the observed hardening effect. Finite element method simulations are used to model the mechanical response of the silica balls, confirming that the intrinsic properties (such as the Young’s modulus) of amorphous silica can be tailored with the electron beam on the nanoscale

  6. Crack-induced debonding failure in fiber reinforced plastics (FRP) strengthened concrete beams: Experimental and theoretical analysis

    Science.gov (United States)

    Pan, Jinlong

    External bonding of FRP plates to the tension substrate of RC beams has been accepted as an efficient and effective technique for flexural strengthening. In this thesis, different problems related to crack-induced debonding of the FRP plate in the flexural strengthened concrete beams have been investigated. FRP strengthened RC beam may fail by FRP debonding from the bottom of a major flexural crack in the span. This kind of failure is studied with the direct shear test in the present research work. Our experimental investigation focuses on the effect of concrete composition on the bond behavior between FRP and concrete. Based on the test results, the bond capacity of the specimen is found to be governed by the concrete surface tensile strength, aggregate size and aggregate content. Then, the neural network is employed to derive an empirical expression for the interfacial fracture energy in terms of concrete surface tensile strength and aggregate content. Using the empirical equation, simulated bond capacity is in good agreement with experimental results. In the FRP strengthened RC beams, debonding of the FRP plate often occurs under the presence of multiple cracks along the span. In the present thesis, experimental and theoretical investigations are performed to study the effect of multiple secondary cracks on the debonding behavior and ultimate load capacity. A new analytical model for FRP debonding under multiple cracks has been developed. The effect of the multiple secondary cracks on the shear softening in the debonded zone is explicitly considered in the model. Using the new model, the simulated values of ultimate load when debonding occurs are in good agreement with measured values. In the FRP strengthened RC beams, concrete cover separation or plate end debonding can be avoided by applying tapers at the FRP plate end. In this situation, it is easier for FRP debonding to be induced by a major flexural crack close to the support. To study the effect of the

  7. E-Beam Effects on CMOS Active Pixel Sensors

    International Nuclear Information System (INIS)

    Three different CMOS active pixel structures manufactured in a deep submicron process have been evaluated with electron beam. The devices were exposed to 1 MeV electron beam up to 5kGy. Dark current increased after E-beam irradiation differently at each pixel structure. Dark current change is dependent on CMOS pixel structures. CMOS image sensors are now good candidates in demanding applications such as medical image sensor, particle detection and space remote sensing. In these situations, CISs are exposed to high doses of radiation. In fact radiation is known to generate trapped charge in CMOS oxides. It can lead to threshold voltage shifts and current leakages in MOSFETs and dark current increase in photodiodes. We studied ionizing effects in three types of CMOS APSs fabricated by 0.25 CMOS process. The devices were irradiated by a Co60 source up to 50kGy. All irradiation took place at room temperature. The dark current in the three different pixels exhibits increase with electron beam exposure. From the above figure, the change of dark current is dependent on the pixel structure. Double junction structure has shown relatively small increase of dark current after electron beam irradiation. The dark current in the three different pixels exhibits increase with electron beam exposure. The contribution of the total ionizing dose to the dark current increase is small here, since the devices were left unbiased during the electron beam irradiation. Radiation hardness in dependent on the pixel structures. Pixel2 is relatively vulnerable to radiation exposure. Pixel3 has radiation hardened structure

  8. 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)

  9. LTRACK: Beam-transport calculation including wakefield effects

    International Nuclear Information System (INIS)

    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

  10. Designing a program to assess potential induced radioactivity in electron beam sterilization of medical devices

    International Nuclear Information System (INIS)

    ISO 11137-1:2006 requires that the potential for induced radioactivity be evaluated for medical devices irradiated with electrons with energy more than 10 MeV. For a manufacturing operation where new devices are being developed, a practical program for making such an evaluation needs to be engrained in the process. A program was developed such that the induced radioactivity evaluation is imbedded in the development of the irradiation process. - Highlights: • A program is described to evaluate induced radioactivity in electron beam. • The program entails evaluation of design prior to manufacturing. • Radiation measurement is done immediately following irradiation. • The instrument has adequate sensitivity for this purpose

  11. Some properties of atomic beam produced by laser induced ablation of Li target

    International Nuclear Information System (INIS)

    Pulsed atomic beams produced in vacuum by laser induced ablation from a lithium target are analyzed by laser induced fluorescence (LIF). The 1-mixing processes induced in the n = 9, 10 Li Rydberg states by collisions with CO2 molecules illustrate the application of the method. Resolution is limited by the 1 mm diameter of the probe laser beam. Combining LIF and absorption measurements gives nLi as a function of time at various distances from the target surface. The investigation of the Li-C02 1-mixing process in a heat pipe oven proved impossible due to the high reactivity of Li with C02. This problem was solved by renewing the Li atoms at each laser shot. Values obtained for n = 9, n = 10 are k = 17 x 10-8 and 15 x 10-8 cc/sec, respectively

  12. Light-induced spiral mass transport in azo-polymer films under vortex-beam illumination

    CERN Document Server

    Ambrosio, Antonio; Borbone, Fabio; Roviello, Antonio; Maddalena, Pasqualino

    2012-01-01

    When an azobenzene-containing polymer film is exposed to a non-uniform illumination, a light-induced mass migration process may be induced, leading to the formation of relief patterns on the polymer free surface. Despite a research effort of many years and several proposed models many aspects of this phenomenon remain not well understood. Here we report the appearance of spiral-shaped relief patterns on the polymer under the illumination of focused Laguerre-Gauss beams, having helical wavefront and an optical vortex at their axis. The induced spiral reliefs are sensitive to the vortex topological charge and to the wavefront handedness. These findings are unexpected, because the "doughnut"-shaped intensity profile of Laguerre- Gauss beams contains no information about the wavefront handedness. We propose a model that explains the main features of this phenomenon from the surface-mediated interference of the longitudinal and the transverse components of the optical field. These results may find applications in ...

  13. Effect of beam-pointing errors on bistatic SAR imaging

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The purpose is to conduct a research in the energy variation of echo wave and the imaging effect caused by the aero bistatic SAR pointing errors.Based on the moving geometry configuration of aero bistatic SAR,a model of beam pointing errors is built.Based on this,the azimuth Doppler frequency center estimation caused by these errors and the limitation to the beam pointing synchronization error are studied,and then the imaging result of different errors are analyzed.The computer's simulations are provided to prove the validity of the above analysis.

  14. 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.

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

    International Nuclear Information System (INIS)

    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

  16. Theoretical evaluation of induced radioactivity in food products by electron or X-ray beam sterilization

    International Nuclear Information System (INIS)

    We evaluate first the energy density for electrons or X-ray beams necessary to produce a reference level of 1 kilogray at the maximum of dose, as a function of energy, for electrons and bremsstrahlung photons, based on experimental data obtained on radio-therapy beams, from 4 to 32 MeV, and irradiation beams from production plant CARIC. Then from the production of neutrons on the tungsten target and from (γn) reactions on the deuterium content of the irradiated food, the slowing down and capture of these neutrons is estimated. Radioisotopes can be produced by (γn) reactions on iodine, and to a lesser extent on tin, lead, barium, etc., but the major contribution is neutron activation, where the more critical elements are sodium, chlorine, potassium, magnesium, phosphorus, calcium. Induced activity is compared to natural activity coming from potassium 40, carbon 14 and radium, contained in all foods. For electrons up to 1 Mrad the induced activity remains of the order of a few percent of natural activity, for energies below 10 to 11 MeV. Bremsstrahlung X-ray irradiations can give comparable levels as soon as the energy of the generating electron beam is above 3 MeV. The induced activity decays within a few days. (author)

  17. Effect of electron beam irradiation on seed germination

    International Nuclear Information System (INIS)

    Effect of electron beam irradiation on seed germination was investigated in this research. Electron beam of 0.5, 1.0, 1.5 and 2.0 kGy was irradiated to the seeds of lettuce, green onion and cucumber, and the irradiated seeds were incubated at 25 .deg. Cn Nitsch medium solidified with 0.2% Phytagel. Germination percentage and the length of the sprouts were determined after 72 hours. Germination percentage of lettuce seeds was greatly reduced by the irradiation, and that of the green onion and cucumber were moderately reduced or unchanged by the irradiation. Although average length of the lettuce sprouts was reduced severely, that of the green onion and cucumber was unchanged or moderately reduced. Conclusively, electron beam irradiation might be a useful way of disinfecting some plant seeds including green onion and cucumber

  18. Effect of electron beam irradiation on seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seunghee; Bae, Youngmin [Changwon Univ., Changwon (Korea, Republic of)

    2013-07-01

    Effect of electron beam irradiation on seed germination was investigated in this research. Electron beam of 0.5, 1.0, 1.5 and 2.0 kGy was irradiated to the seeds of lettuce, green onion and cucumber, and the irradiated seeds were incubated at 25 .deg. Cn Nitsch medium solidified with 0.2% Phytagel. Germination percentage and the length of the sprouts were determined after 72 hours. Germination percentage of lettuce seeds was greatly reduced by the irradiation, and that of the green onion and cucumber were moderately reduced or unchanged by the irradiation. Although average length of the lettuce sprouts was reduced severely, that of the green onion and cucumber was unchanged or moderately reduced. Conclusively, electron beam irradiation might be a useful way of disinfecting some plant seeds including green onion and cucumber.

  19. Review of Surface Roughness Effect on Beam Quality

    Science.gov (United States)

    Mostacci, A.; Palumbo, L.; Alesini, D.

    2003-12-01

    In recent years a strong attention arose around the problem of the e.m. interaction of an ultra-relativistic beam with the residual roughness inside a beam tube, in particular in the framework of future 4th generation coherent light sources. The main concern was the effect of the wake-fields on the relative energy spread of the beam which has to be of the order of 10-4, as for example in the LCLS and TESLA case. Although the real roughness has a stochastic feature, most studies dealt with periodic structure, or dielectric-equivalent layer which are considered to be conservative with respect the stochastic case. In this paper we will review the main theoretical models, and the most significant measurements trying to provide to the reader a complete picture of the present status of understanding.

  20. Effect of electron-beam irradiation on graphene field effect devices

    OpenAIRE

    Childres, I.; Jauregui, L A; Foxe, M.; Tian, J. F.; R. Jalilian; Jovanovic, I; Chen, Y P

    2010-01-01

    Electron beam exposure is a commonly used tool for fabricating and imaging graphene-based devices. Here, we present a study of the effects of electron-beam irradiation on the electronic transport properties of graphene and the operation of graphene field-effect transistors (GFETs). Exposure to a 30 keV electron-beam caused negative shifts in the charge-neutral point (CNP) of the GFET, interpreted as due to n-dopin...

  1. Electron beam irradiation effects on aromatic polymers

    International Nuclear Information System (INIS)

    Electron irradiation effects on aromatic polymers having various molecular structures were studied to elucidate the following subjects; (1) relation between radiation stability and molecular structure of repeating units, (2) mechanism of deterioration and (3) adaptability to matrix resin for radiation resistant FRP. Results are summarized as follows: (1) An order of radiation stability of units is; imide ring > diphenyl ether, diphenyl ketone > aromatic amide >> bis-phenol A > diphenyl sulphone. (2) Poly (ether-ether-ketone) and most polyimide are crosslinkable but polysulphones and polyarylate are chain degradation type polymers. (3) Newly developed thermoplastic polyimides have possibilities for use as matrix materials in radiation resistant FRP. (author)

  2. Evidence of liquid phase during laser-induced periodic surface structures formation induced by accumulative ultraviolet picosecond laser beam

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, T. T. D.; Petit, A.; Semmar, N., E-mail: nadjib.semmar@univ-orleans.fr [GREMI, UMR7344, CNRS/University of Orleans, 14 rue d' Issoudun, BP6744, 45067 Orleans Cedex 2 (France); Vayer, M. [ICMN, UMR 7374, CNRS/University of Orleans, 1b rue de la Ferollerie, CS 40059, 45071 Orleans Cedex (France); Sauldubois, A. [CME, UFR Sciences, University of Orleans, 1 Rue de Chartres, BP 6759, 45067 Orleans Cedex 2 (France)

    2015-11-09

    Laser-induced periodic surface structures (LIPSS) were formed on Cu/Si or Cu/glass thin films using Nd:YAG laser beam (40 ps, 10 Hz, and 30 mJ/cm{sup 2}). The study of ablation threshold is always achieved over melting when the variation of the number of pulses increases from 1 to 1000. But the incubation effect is leading to reduce the threshold of melting as increasing the number of laser pulse. Also, real time reflectivity signals exhibit typical behavior to stress the formation of a liquid phase during the laser-processing regime and helps to determine the threshold of soft ablation. Atomic Force Microscopy (AFM) analyses have shown the topology of the micro-crater containing regular spikes with different height. Transmission Electron Microscopy (TEM) allows finally to show three distinguished zones in the close region of isolated protrusions. The central zone is a typical crystallized area of few nanometers surrounded by a mixed poly-crystalline and amorphous area. Finally, in the region far from the protrusion zone, Cu film shows an amorphous structure. The real time reflectivity, AFM, and HR-TEM analyses evidence the formation of a liquid phase during the LIPSS formation in the picosecond regime.

  3. Evidence of liquid phase during laser-induced periodic surface structures formation induced by accumulative ultraviolet picosecond laser beam

    Science.gov (United States)

    Huynh, T. T. D.; Vayer, M.; Sauldubois, A.; Petit, A.; Semmar, N.

    2015-11-01

    Laser-induced periodic surface structures (LIPSS) were formed on Cu/Si or Cu/glass thin films using Nd:YAG laser beam (40 ps, 10 Hz, and 30 mJ/cm2). The study of ablation threshold is always achieved over melting when the variation of the number of pulses increases from 1 to 1000. But the incubation effect is leading to reduce the threshold of melting as increasing the number of laser pulse. Also, real time reflectivity signals exhibit typical behavior to stress the formation of a liquid phase during the laser-processing regime and helps to determine the threshold of soft ablation. Atomic Force Microscopy (AFM) analyses have shown the topology of the micro-crater containing regular spikes with different height. Transmission Electron Microscopy (TEM) allows finally to show three distinguished zones in the close region of isolated protrusions. The central zone is a typical crystallized area of few nanometers surrounded by a mixed poly-crystalline and amorphous area. Finally, in the region far from the protrusion zone, Cu film shows an amorphous structure. The real time reflectivity, AFM, and HR-TEM analyses evidence the formation of a liquid phase during the LIPSS formation in the picosecond regime.

  4. Evidence of liquid phase during laser-induced periodic surface structures formation induced by accumulative ultraviolet picosecond laser beam

    International Nuclear Information System (INIS)

    Laser-induced periodic surface structures (LIPSS) were formed on Cu/Si or Cu/glass thin films using Nd:YAG laser beam (40 ps, 10 Hz, and 30 mJ/cm2). The study of ablation threshold is always achieved over melting when the variation of the number of pulses increases from 1 to 1000. But the incubation effect is leading to reduce the threshold of melting as increasing the number of laser pulse. Also, real time reflectivity signals exhibit typical behavior to stress the formation of a liquid phase during the laser-processing regime and helps to determine the threshold of soft ablation. Atomic Force Microscopy (AFM) analyses have shown the topology of the micro-crater containing regular spikes with different height. Transmission Electron Microscopy (TEM) allows finally to show three distinguished zones in the close region of isolated protrusions. The central zone is a typical crystallized area of few nanometers surrounded by a mixed poly-crystalline and amorphous area. Finally, in the region far from the protrusion zone, Cu film shows an amorphous structure. The real time reflectivity, AFM, and HR-TEM analyses evidence the formation of a liquid phase during the LIPSS formation in the picosecond regime

  5. Ion-beam-induced nanodots formation from Au/Si thin films on quartz surface

    Science.gov (United States)

    Datta, D. P.; Siva, V.; Singh, A.; Joshi, S. R.; Kanjilal, D.; Sahoo, P. K.

    2016-07-01

    We report the synthesis of Si nanodots on quartz surface using ion irradiation. When a bi-layer of ultrathin Au and Si on quartz surface is irradiated by 500 keV Xe-ion beam, the bi-layer spontaneously transforms into nanodots at a fluence of 5 × 1014 ions cm-2. The spatial density and diameter of the nanodots are reduced with increase in applied ion fluence. The nanostructures exhibit photoluminescence in the visible range at room temperature where the intensity and wavelength depends upon ion fluence. The observed evolution seems to be correlated to ion beam mixing induced silicide formation at Au-Si interface.

  6. Experimental and numerical analysis of corrosion induced cover cracking in reinforced concrete beam

    OpenAIRE

    Richard, Benjamin; Quiertant, Marc; Bouteiller, Véronique; Adelaide, Lucas; PERRAIS, Maxime; Tailhan, Jean-Louis; CREMONA, Christian

    2010-01-01

    This paper aims to present both experimental and numerical studies of the corrosion induced cracking pattern evolution of a reinforced concrete sample subjected to accelerated corrosion. The sample was a concrete beam (1000x250x100 mm3) reinforced with two rebars (20 mm diameter; 25 mm cover). The beam was not mechanically loaded. The corrosion process was applied on 500 mm rebar length on the central part. Rebars were intentiostatically corroded using a current density of 100µA/cm² of steel,...

  7. Site control technique for quantum dots using electron beam induced deposition

    Science.gov (United States)

    Iizuka, Kanji; Jung, JaeHun; Yokota, Hiroshi

    2014-05-01

    To develop simple and high throughput sit definition technique for quantum dots (QDs), the electron beam induced deposition (EBID) method was used as desorption guide of phosphorus atoms form InP substrate. As the results one or a few indium (In) droplets (DLs) were created in the carbon grid pattern by thermal annealing at a temperature of 450°C for 10 min in the ultra high vacuum condition. The size of In DLs was larger than QDs, but arsenide DLs by molecular beam in growth chamber emitted wavelength of 1.028μm at 50K by photoluminescence measurement.

  8. Flow-Induced Beam Steering in a Single Laser Hot Spot

    International Nuclear Information System (INIS)

    The transmitted angular distribution of a 527 nm nearly diffraction-limited laser is measured after it propagates through a plasma with supersonic transverse flow. The laser beam is deflected by as much as 10 degree sign and exhibits bowlike features in the flow direction, which is attributed to flow-induced beam steering. The finite interaction volume allows for direct comparison with a 3D hydrodynamic simulation, which is in good agreement with details of the experiment. (c) 2000 The American Physical Society

  9. Novel signal inversion of laser beam induced current for femtosecond-laser-drilling-induced junction on vacancy-doped p-type HgCdTe

    International Nuclear Information System (INIS)

    In this paper, experimental results of temperature-dependent signal inversion of laser beam induced current (LBIC) for femtosecond-laser-drilling-induced junction on vacancy-doped p-type HgCdTe are reported. LBIC characterization shows that the traps induced by femtosecond laser drilling are sensitive to temperature. Theoretical models for trap-related p-n junction transformation are proposed and demonstrated using numerical simulations. The simulations are in good agreement with the experimental results. The effects of traps and mixed conduction are possibly the main reasons that result in the novel signal inversion of LBIC microscope at room temperature. The research results provide a theoretical guide for practical applications of large-scale array HgCdTe infrared photovoltaic detectors formed by femtosecond laser drilling, which may act as a potential new method for fabricating HgCdTe photodiodes.

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

    Science.gov (United States)

    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.

    2015-11-01

    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)×10-9 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)×1013 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

    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.

  12. Experimental analysis of energy harvesting from self-induced flutter of a composite beam

    International Nuclear Information System (INIS)

    Previous attempts to harvest energy from aeroelastic vibrations have been based on attaching a beam to a moving wing or structure. Here, we exploit self-excited oscillations of a fluttering composite beam to harvest energy using piezoelectric transduction. Details of the beam properties and experimental setup are presented. The effects of preset angle of attack, wind speed, and load resistance on the levels of harvested power are determined. The results point to a complex relation between the aerodynamic loading and its impact on the static deflection and amplitudes of the limit cycle oscillations on one hand and the load resistance and level of power harvested on the other hand

  13. Experimental analysis of energy harvesting from self-induced flutter of a composite beam

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, Mohamed Y., E-mail: zakaria@vt.edu; Al-Haik, Mohammad Y.; Hajj, Muhammad R. [Virginia Tech, Norris Hall, Blacksburg, Virginia 24061 (United States)

    2015-07-13

    Previous attempts to harvest energy from aeroelastic vibrations have been based on attaching a beam to a moving wing or structure. Here, we exploit self-excited oscillations of a fluttering composite beam to harvest energy using piezoelectric transduction. Details of the beam properties and experimental setup are presented. The effects of preset angle of attack, wind speed, and load resistance on the levels of harvested power are determined. The results point to a complex relation between the aerodynamic loading and its impact on the static deflection and amplitudes of the limit cycle oscillations on one hand and the load resistance and level of power harvested on the other hand.

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

    International Nuclear Information System (INIS)

    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)

  15. 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...

  16. The effects of carbon foil on beams in stripping-accumulation of a heavy-ion synchrotron

    International Nuclear Information System (INIS)

    Stripping-injection scheme is adopted in the synchrotron of an accelerator complex named as HITFiL. HITFIL is dedicated to cancer therapy. High intensity can be reached by using the stripping-injection as the limit of Liouville's theorem is broken due to charge-exchange. But unavoidable traversals of the circulating beams through the foil may cause beam-losses and deteriorations of beam quality, including: 1) beam-losses caused by an alteration of the particles' charge state; 2) emittance growth caused by Multiple Coulomb Scattering; and 3) decrease of mean-momentum and growth of momentum spread induced by energy loss and energy loss straggling. In this paper, the model of particle-foil interaction is established by Monte Carlo processes. The effects of the stripping foil on beams are studied based on an improvement of the ACCSIM code. (authors)

  17. X-ray-induced beam damage observed during x-ray photoelectron spectroscopy (XPS) studies of palladium electrode ink materials

    International Nuclear Information System (INIS)

    The surface compositional characteristics of two palladium metal electrode inks, air-dried on barium titanate (BaTiO3) dielectric ceramic substrates, have been studied using x-ray photoelectron spectroscopy (XPS). It is found that exposure of the inks to the x-ray beam during the time of analysis required for data acquisition causes surface damage. Changes in the C 1s and O 1s regions in particular, which reflect modifications to the organic, polymeric binder materials present in the inks, have been integrated as a function of x-ray exposure time, incident photon energy and beam power levels. Additional complexity in the C 1s spectral envelope that cannot be explained in terms of the expected contributing organic functionalities is observed. This is explained in terms of a difference in charging effects experienced by adventitious carbon species and those intimately associated with palladium metal centres. The degree of damage induced by the x-ray beam under specific operating conditions has been compared also with that caused by exposure of the surfaces to an electron beam. Indications of the time scales and operating parameters for conducting XPS experiments on the unmodified surface, prior to surface degradation, are given. (author)

  18. Note: Ion-induced secondary electron emission from oxidized metal surfaces measured in a particle beam reactor

    Energy Technology Data Exchange (ETDEWEB)

    Marcak, Adrian; Corbella, Carles, E-mail: carles.corbella@rub.de; Keudell, Achim von [Research Group Reactive Plasmas, Ruhr-University Bochum, 44801 Bochum (Germany); Arcos, Teresa de los [Technical and Macromolecular Chemistry, Paderborn University, 33098 Paderborn (Germany)

    2015-10-15

    The secondary electron emission of metals induced by slow ions is characterized in a beam chamber by means of two coaxial semi-cylindrical electrodes with different apertures. The voltages of the outer electrode (screening), inner electrode (collector), and sample holder (target) were set independently in order to measure the effective yield of potential and kinetic electron emissions during ion bombardment. Aluminum samples were exposed to quantified beams of argon ions up to 2000 eV and to oxygen atoms and molecules in order to mimic the plasma-surface interactions on metallic targets during reactive sputtering. The variation of electron emission yield was correlated to the ion energy and to the oxidation state of Al surfaces. This system provides reliable measurements of the electron yields in real time and is of great utility to explore the fundamental surface processes during target poisoning occurring in reactive magnetron sputtering applications.

  19. Note: Ion-induced secondary electron emission from oxidized metal surfaces measured in a particle beam reactor

    International Nuclear Information System (INIS)

    The secondary electron emission of metals induced by slow ions is characterized in a beam chamber by means of two coaxial semi-cylindrical electrodes with different apertures. The voltages of the outer electrode (screening), inner electrode (collector), and sample holder (target) were set independently in order to measure the effective yield of potential and kinetic electron emissions during ion bombardment. Aluminum samples were exposed to quantified beams of argon ions up to 2000 eV and to oxygen atoms and molecules in order to mimic the plasma-surface interactions on metallic targets during reactive sputtering. The variation of electron emission yield was correlated to the ion energy and to the oxidation state of Al surfaces. This system provides reliable measurements of the electron yields in real time and is of great utility to explore the fundamental surface processes during target poisoning occurring in reactive magnetron sputtering applications

  20. Note: Ion-induced secondary electron emission from oxidized metal surfaces measured in a particle beam reactor

    Science.gov (United States)

    Marcak, Adrian; Corbella, Carles; de los Arcos, Teresa; von Keudell, Achim

    2015-10-01

    The secondary electron emission of metals induced by slow ions is characterized in a beam chamber by means of two coaxial semi-cylindrical electrodes with different apertures. The voltages of the outer electrode (screening), inner electrode (collector), and sample holder (target) were set independently in order to measure the effective yield of potential and kinetic electron emissions during ion bombardment. Aluminum samples were exposed to quantified beams of argon ions up to 2000 eV and to oxygen atoms and molecules in order to mimic the plasma-surface interactions on metallic targets during reactive sputtering. The variation of electron emission yield was correlated to the ion energy and to the oxidation state of Al surfaces. This system provides reliable measurements of the electron yields in real time and is of great utility to explore the fundamental surface processes during target poisoning occurring in reactive magnetron sputtering applications.

  1. Modeling of astigmatic-elliptical beam shaping during fs-laser waveguide writing including beam truncation and diffraction effects

    Science.gov (United States)

    Ruiz De la Cruz, A.; Ferrer, A.; del Hoyo, J.; Siegel, J.; Solis, J.

    2011-08-01

    In this work, we report a model for accurately calculating the focal volumes corresponding to astigmatic elliptical beams used in fs-laser waveguide writing. The model is based on the use of the ABCD matrix formalism for the propagation of a Gaussian beam. The code includes the effects of propagation on the astigmatic elliptical beam, and the effects of beam truncation and diffraction at the entrance pupil of the focusing objective due to beam clipping when overfilling the pupil. The results predict that for a given astigmatism value and propagation distance it is possible to efficiently suppress the astigmatic focus closer to the surface. This explains previous experimental results where single structure waveguides with controllable aspect-ratio were fabricated using astigmatic-elliptical beams. Furthermore, we investigate the respective roles of astigmatism and beam propagation, as well as the strong impact of truncation and diffraction effects caused by clipping the beam at the pupil of the focusing optics. Finally, based on the results from our model, we present some practical considerations in terms of beam propagation and phase wrapping constraints.

  2. Studies of Beam Induced Electron Cloud Resonances in Dipole Magnetic Fields

    OpenAIRE

    Calvey, J. R.; Hartung, W.; Makita, J.; Venturini, M.

    2016-01-01

    The buildup of low energy electrons in an accelerator, known as electron cloud, can be severely detrimental to machine performance. Under certain beam conditions, the beam can become resonant with the cloud dynamics, accelerating the buildup of electrons. This paper will examine two such effects: multipacting resonances, in which the cloud development time is resonant with the bunch spacing, and cyclotron resonances, in which the cyclotron period of electrons in a magnetic field is a multiple...

  3. Evaluation of radioprotective efficacy of pyrimidine-5- carboxylate derivative on electron beam induced oxidative stress using Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Protection of biological systems against radiation damage is of paramount importance during accidental and unavoidable exposure to radiation. Several physico-chemical and biological factors collectively contribute to the damage caused by radiation and are, therefore, targets for developing radioprotectors. Chemicals capable of scavenging free radicals, inducing oxygen depletion, ant ioxidants and modulators of immune response have been some of the radioprotectors extensively investigated with limited success. In the present study the radioprotective efficacy of Ethyl 4-(4-(benzyloxy)phenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydro pyrimidine-5-carboxylate on electron beam induced oxidative stress was evaluated using Drosophila melanogaster (Oregon K). Initially the molecule was tested for in vitro antioxidant activity and it showed moderate DPPH radical scavenging activity and good hydroxyl radical scavenging activity compared to standard glutathione. Hence, this compound was screened for its radioprotective activity. The compound was supplied to flies in the form of diet. The electron beam irradiated flies were assayed for oxidative stress markers name Thiobarbituric acid reactive substances (TBARS), enzymatic and Non-enzymatic antioxidants. The pyrimidinone showed modulator effect on the oxidative stress markers caused by e-beam radiation. (author)

  4. Biological effect of carbon beams on cultured human cells

    International Nuclear Information System (INIS)

    This study was performed to determine the biological effect of carbon beams on 13 human tumor cells, in comparison with 200 KVp X-rays. Carbon beams were generated by the Riken Ring Cyclotron. The RBE (relative biological effectiveness) values were distributed from 1.46 to 2.20 for LET of 20 keV/μm, and 2.29-3.54 for 80 keV/μm. The RBEs were increased in all cell lines as the LET of carbon beams was increased from 20 to 80 keV/μm. There was no significant difference in radiosensitivity between cells from adenocarcinoma and those from squamous cell carcinoma. The relationship between the radiosensitivity of cells to X-rays and RBE was analyzed, but no significant correlation was suggested. Several survival curves of 20-40 keV/μm carbon beam irradiation showed the initial shoulders and the recovery ratios between two split doses were determined. Recovery was observed for LET of 2O keV/μm but not for that of 40 keV/μm. Furthermore, recovery ratios were 1.0-1.8, smaller than those for X-rays (1.5-2.4). (author)

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

    International Nuclear Information System (INIS)

    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)

  6. Fibre-Coupling Zig-Zag Beam Deflection Technology for Investigation of Attenuation Process of Laser-Induced Shock Waves

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping; BIAN Bao-Min; LI Zhen-Hua

    2005-01-01

    @@ A novel fibre-coupling zig-zag beam deflection technology is developed to investigate the attenuation process of laser-induced shock waves in air. Utilizing ordinal reflections of probe beams by a pair of parallel mirrors,a zig-zag beam field is formed, which has eleven probe beams in the horizontal plane. When a laser-induced shock wave propagates through the testing field, it causes eleven deflection signals one after another. The whole attenuation process of the shock wave in air can be detected and illuminated clearly on one experimental curve.

  7. Ion beam induced luminescence analysis of defect evolution in lithium fluoride under proton irradiation

    Science.gov (United States)

    Quaranta, A.; Valotto, G.; Piccinini, M.; Montereali, R. M.

    2015-11-01

    Ion beam induced luminescence (IBIL) spectra of pure LiF under irradiation by a 2 MeV proton beam were analyzed as a function of the dose in order to deepen the kinetic mechanisms underlying the formation of luminescent point defects. The intensity evolution with dose at several emission wavelengths has been studied within a wide spectral interval, from ultraviolet (UV) to near infrared (NIR), and their different change rates have been correlated to the electronic defect formation processes. The intensity at few selected wavelengths was analyzed with a multiple linear regression (MLR) method in order to demonstrate that a linear calibration curve can be obtained and that an on-line optical dose monitor for ion beams can be realized.

  8. Biological effects of clustered DNA damage produced by heavy ion beams with its complexity

    International Nuclear Information System (INIS)

    Heavy ion beams produce denser ionized region around their track, and generate cluster of damage accumulated in certain region of target DNA molecule. The damage aggregate is termed as clustered DNA damage (CDD), that is thought to be one of major drivers causes specific radiation effect for any organisms. Among any ionizing radiations generating CDD with respective degree, heavy ion beams more effectively produce CDD than low-linear energy transfer (LET) radiations such as gamma-rays and X-rays. In the present study, we evaluated how CDD is involved in the degree of radiobiological effect. Our present study had two parts; one was to analyze the structure of CDD induced by heavy ion beams used with oligodeoxyribonucleotide targets. In this part, we studied analysis procedure of number and species of respective damage in the cluster. Another part was for estimating total DNA damage in the cells irradiated with heavy ion beams, because we had no investigation for whole damage in our previous report. (author)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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.)

  11. Thermal effects in high power cavities for photoneutralization of D- beams in future neutral beam injectors

    Science.gov (United States)

    Fiorucci, Donatella; Feng, Jiatai; Pichot, Mikhaël; Chaibi, Walid

    2015-04-01

    Photoneutralization may represent a key issue in the neutral beam injectors for future fusion reactors. In fact, photodetachment based neutralization combined with an energy recovery system increase the injector overall efficiency up to 60%. This is the SIPHORE injector concept in which photoneutralization is realized in a refolded cavity [1]. However, about 1 W of the several megaWatts intracavity power is absorbed by the mirrors coatings and gives rise to important thermoelastic distortions. This is expected to change the optical behavior of the mirrors and reduce the enhancement factor of the cavity. In this paper, we estimate these effects and we propose a thermal system to compensate it.

  12. Focused ion beam (FIB)-induced changes in the electrochemical behavior of boron-doped diamond (BDD) electrodes

    International Nuclear Information System (INIS)

    Micro- and nanostructured electrodes play a significant role in modern electroanalytical chemistry. Here, we report on the effect of focused ion beam-induced changes in the surface layers of nanocrystalline highly boron-doped diamond (BDD). The impact of gallium ions induces an amorphization of the surface layers of the BDD lattice, and hence, changes the electron transfer behavior of redox species, which electron transfer is sensitive to surface properties. These changes in heterogeneous electron transfer behavior are investigated in dependence of FIB patterning parameters. The effects of electrochemical post-milling treatments were studied for restoring the electrochemical properties. In addition, Raman spectroscopic and electron backscatter diffraction (EBSD) measurements revealed that amorphous carbon is largely removed during the post-milling electrochemical treatment at very negative potentials. Hence, FIB-based nanostructuring of BDD-electrodes with an optimized post fabrication treatment enables the fabrication of miniaturized devices based on boron-doped diamond for a wide variety of electroanalytical applications

  13. Electron-beam induced deposition and autocatalytic decomposition of Co(CO3NO

    Directory of Open Access Journals (Sweden)

    Florian Vollnhals

    2014-07-01

    Full Text Available The autocatalytic growth of arbitrarily shaped nanostructures fabricated by electron beam-induced deposition (EBID and electron beam-induced surface activation (EBISA is studied for two precursors: iron pentacarbonyl, Fe(CO5, and cobalt tricarbonyl nitrosyl, Co(CO3NO. Different deposits are prepared on silicon nitride membranes and silicon wafers under ultrahigh vacuum conditions, and are studied by scanning electron microscopy (SEM and scanning transmission X-ray microscopy (STXM, including near edge X-ray absorption fine structure (NEXAFS spectroscopy. It has previously been shown that Fe(CO5 decomposes autocatalytically on Fe seed layers (EBID and on certain electron beam-activated surfaces, yielding high purity, polycrystalline Fe nanostructures. In this contribution, we investigate the growth of structures from Co(CO3NO and compare it to results obtained from Fe(CO5. Co(CO3NO exhibits autocatalytic growth on Co-containing seed layers prepared by EBID using the same precursor. The growth yields granular, oxygen-, carbon- and nitrogen-containing deposits. In contrast to Fe(CO5 no decomposition on electron beam-activated surfaces is observed. In addition, we show that the autocatalytic growth of nanostructures from Co(CO3NO can also be initiated by an Fe seed layer, which presents a novel approach to the fabrication of layered nanostructures.

  14. Beam Energy Scaling on Ion-Induced Electron Yield from K+ Impacton Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Kireeff Covo, Michel; Molvik, Arthur; Friedman, Alex; Westenskow,Glen; Barnard, John J.; Cohen, Ronald; Grote, David; Lund, Steven M.; Seidl, Peter; Kwan, Joe W.; Logan, Grant; Baca, David; Bieniosek, Frank; Celata, Christine M.; Vay Jean-Luc; Vujic, Jasmina L.

    2006-01-01

    Electron clouds limit the performance of many major accelerators. Significant quantities of electrons result when halo ions are lost to beam tubes, generating gas which can be ionized and ion-induced electrons that can multiply and accumulate, causing degradation or loss of the ion beam. In order to understand the physical mechanisms of ion-induced electron production, experiments studied the impact of 50 to 400 keV K{sup +} ions on stainless steel surfaces near grazing incidence, using the 500 kilovolts Ion Source Test Stand (STS-500) at LLNL. The experimental electron yield scales with the electronic component (dE{sub e}/dx) of the stopping power. A theoretical model is developed, using TRIM code to evaluate dE{sub e}/dx at several depths in the target, to estimate the electron yield, which is compared with the experimental results.

  15. 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.

  16. Suspended nanostructures grown by electron beam-induced deposition of Pt and TEOS precursors

    International Nuclear Information System (INIS)

    Suspended nanostructures (SNSs) are grown by electron beam-induced deposition (EBID) of Pt and tetra-ethyl-ortho-silicate (TEOS) gas precursors on nanopillar tips, by lateral shifting of a scanning electron microscope beam. Shape evolution of SNSs is characterized as a function of electron energy (5, 10, 15 keV) and electron charge deposited per unit length (CDL, 1-9 pC nm-1 range) along the beam track. Pt SNSs grow as single nanowires, evolving from thin (15-20 nm) and horizontal to thick (up to 70 nm) and inclined (up to 600) geometry as CDL increases. TEOS SNSs consist of multiple nanowires arranged in a stack: horizontal and parallel along the beam shift direction and aligned on top of each other along the beam incidence axis. As the CDL increases, the number of nanowires increases and the top edge of the stack progressively inclines, taking the form of a hand-fan. Deposition yield and overall size of SNSs are found to be proportional to CDL and inversely proportional to electron energy for both Pt and TEOS precursors. As an example of 3D nanoarchitectures achievable by this lateral EBID approach, a 'nano-windmill' TEOS structure is presented

  17. Gas-assisted electron-beam-induced nanopatterning of high-quality titanium oxide

    Science.gov (United States)

    Riazanova, A. V.; Costanzi, B. N.; Aristov, A. I.; Rikers, Y. G. M.; Mulders, J. J. L.; Kabashin, A. V.; Dahlberg, E. Dan; Belova, L. M.

    2016-03-01

    Electron-beam-induced deposition of titanium oxide nanopatterns is described. The precursor is titanium tetra-isopropoxide, delivered to the deposition point through a needle and mixed with oxygen at the same point via a flow through a separate needle. The depositions are free of residual carbon and have an EDX determined stoichiometry of TiO2.2. High resolution transmission electron microscopy and Raman spectroscopy studies reveal an amorphous structure of the fabricated titanium oxide. Ellipsometric characterization of the deposited material reveals a refractive index of 2.2-2.4 RIU in the spectral range of 500-1700 nm and a very low extinction coefficient (lower than 10-6 in the range of 400-1700 nm), which is consistent with high quality titanium oxide. The electrical resistivity of the titanium oxide patterned with this new process is in the range of 10-40 GΩ cm and the measured breakdown field is in the range of 10-70 V μm-1. The fabricated nanopatterns are important for a variety of applications, including field-effect transistors, memory devices, MEMS, waveguide structures, bio- and chemical sensors.

  18. Post-growth purification of Co nanostructures prepared by focused electron beam induced deposition

    Science.gov (United States)

    Begun, E.; Dobrovolskiy, O. V.; Kompaniiets, M.; Sachser, R.; Gspan, Ch; Plank, H.; Huth, M.

    2015-02-01

    In the majority of cases nanostructures prepared by focused electron beam induced deposition (FEBID) employing an organometallic precursor contain predominantly carbon-based ligand dissociation products. This is unfortunate with regard to using this high-resolution direct-write approach for the preparation of nanostructures for various fields, such as mesoscopic physics, micromagnetism, electronic correlations, spin-dependent transport and numerous applications. Here we present an in situ cleaning approach to obtain pure Co-FEBID nanostructures. The purification procedure lies in the exposure of heated samples to a H2 atmosphere in conjunction with the irradiation by low-energy electrons. The key finding is that the combination of annealing at 300 °C, H2 exposure and electron irradiation leads to compact, carbon- and oxygen free Co layers down to a thickness of about 20 nm starting from as-deposited Co-FEBID structures. In addition to this, in temperature-dependent electrical resistance measurements on post-processed samples we find a typical metallic behavior. In low-temperature magnetoresistance and Hall effect measurements we observe ferromagnetic behavior.

  19. Intriguing surface-extruded plastic flow of SiOx amorphous nanowire as athermally induced by electron beam irradiation.

    Science.gov (United States)

    Zhu, Xianfang; Su, Jiangbin; Wu, Yan; Wang, Lianzhou; Wang, Zhanguo

    2014-01-01

    Nanoinstability and nanoprocessing of a SiOx amorphous nanowire at room temperature as induced by in situ electron beam irradiation in transmission electron microscopy are systematically investigated. It is demonstrated that in contrast to the crystalline nanowires where only the beam-induced ablation of atoms was observed, the amorphous nanowire herein can give rise to an arresting beam-induced surface-extruded plastic flow of massive atoms and surface migration of atoms in addition to the beam-induced ablation of atoms. Via the plastic flow and ablation, a new S-type deformed wire and the thinnest amorphous nanowire are elaborately created locally at nanoscale precision with a highly controllable manner depending on the beam current density, beam spot size, and beam position. The existing knock-on mechanism and simulation seem inadequate to explain these processes. However, it is indicated that a much higher nanocurved surface energy of nanowires and an enhanced beam-induced soft mode and instability of atomic vibration control the processes. PMID:24317010

  20. 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.

  1. Electron-beam induced optical superresolution in integrated light-electron microscopy

    OpenAIRE

    Väkeväinen, Aaro

    2014-01-01

    We have developed an optical superresolution method based on electronbleaching of fluorophores in integrated light-electron microscopy. The main advantage of this novel superresolution method is that the non-fluorescent ultrastructure of the sample can be revealed by the simultaneously acquired SEM image. Furthermore, as the fluorescence superresolution image is based on an electron-beam-induced modification of the specimen, by "switching off" fluorescent probes, both the fluorescence and SEM...

  2. Focused electron beam induced etching of copper in sulfuric acid solutions

    Science.gov (United States)

    Boehme, Lindsay; Bresin, Matthew; Botman, Aurélien; Ranney, James; Hastings, J. Todd

    2015-12-01

    We show here that copper can be locally etched by an electron-beam induced reaction in a liquid. Aqueous sulfuric acid (H2SO4) is utilized as the etchant and all experiments are conducted in an environmental scanning electron microscope. The extent of etch increases with liquid thickness and dose, and etch resolution improves with H2SO4 concentration. This approach shows the feasibility of liquid phase etching for material selectivity and has the potential for circuit editing.

  3. ION-BEAM INDUCED GENERATION OF CU ADATOMS ON CU(100)

    NARCIS (Netherlands)

    BREEMAN, M; BOERMA, DO

    1992-01-01

    Low-energy ion scattering was used to study on-beam induced adatom generation during irradiation of a Cu(100) surface with 6 keV Ne ions at a sample temperature of 60 K. It was found that the number of adatoms produced per incoming ion decreases from an average of 3.5 to a saturation level of 1.8 af

  4. Direct simulation of ion beam induced stressing and amorphization of silicon

    OpenAIRE

    Beardmore, Keith M.; Gronbech-Jensen, Niels

    1999-01-01

    Using molecular dynamics (MD) simulation, we investigate the mechanical response of silicon to high dose ion-irradiation. We employ a realistic and efficient model to directly simulate ion beam induced amorphization. Structural properties of the amorphized sample are compared with experimental data and results of other simulation studies. We find the behavior of the irradiated material is related to the rate at which it can relax. Depending upon the ability to deform, we observe either the ge...

  5. Bulk micromachining of silicon using electron-beam-induced carbonaceous nanomasking

    International Nuclear Information System (INIS)

    This paper reports on an alternative nanolithographic technique for bulk micromachining of silicon. We show how to selectively etch Si(110) in aqueous KOH solutions using electron-beam-induced nanomasking. Already nanometre thin carbonaceous films can completely suppress the wet anisotropic chemical etching of Si performed in alkaline solution (10 wt% KOH+5 wt% isopropanol). It is shown that under optimized conditions, this approach can be exploited for the fabrication of three-dimensional micro- and nanostructures

  6. Bulk micromachining of silicon using electron-beam-induced carbonaceous nanomasking

    Energy Technology Data Exchange (ETDEWEB)

    Djenizian, T [Laboratoire MADIREL (UMR 6121), Electrochemistry of Materials Group, Universite de Provence-CNRS Centre Saint Jerome, F-13397 Marseille Cedex 20 (France); Salhi, B [Institut de Recherche Interdisciplinaire (IRI), Avenue Poincare BP 60069, 59652 Villeneuve d' Ascq (France); Boukherroub, R [Institut de Recherche Interdisciplinaire (IRI), Avenue Poincare BP 60069, 59652 Villeneuve d' Ascq (France); Schmuki, P [Department of Materials Science, University of Erlangen-Nuremberg, WW4-LKO, Martensstrasse 7, D-91058 Erlangen (Germany)

    2006-11-14

    This paper reports on an alternative nanolithographic technique for bulk micromachining of silicon. We show how to selectively etch Si(110) in aqueous KOH solutions using electron-beam-induced nanomasking. Already nanometre thin carbonaceous films can completely suppress the wet anisotropic chemical etching of Si performed in alkaline solution (10 wt% KOH+5 wt% isopropanol). It is shown that under optimized conditions, this approach can be exploited for the fabrication of three-dimensional micro- and nanostructures.

  7. Electron beam induced electronic transport in alkyl amine-intercalated VOx nanotubes

    OpenAIRE

    O'Dwyer, Colm; Lavayen, Vladimir; Clavijo-Cedeno, C.; Sotomayor Torres, Clivia M.

    2008-01-01

    The electron beam induced electronic transport in primary alkyl amine-intercalated V2O5 nanotubes is investigated where the organic amine molecules are employed as molecular conductive wires to an aminosilanized substrate surface and contacted to Au interdigitated electrode contacts. The results demonstrate that the high conductivity of the nanotubes is related to the non-resonant tunnelling through the amine molecules and a reduced polaron hopping conduction through the vanadium oxide itself...

  8. Study on Nanostructures Induced by High-Current Pulsed Electron Beam

    OpenAIRE

    Bo Gao; Yi Hao; Ganfeng Tu; Wenyuan Wu

    2012-01-01

    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 ma...

  9. Beam loading effect on rf system in proton synchrotrons

    International Nuclear Information System (INIS)

    This report describes the stability of an rf system in the presence of beam loading. The analysis is based on the transfer function method given in F. Pedersen (IEEE Trans. Nucl. Sci. NS-22, 1906 (1975)). First, the Routh-Hurwitz criterion is applied to the analysis of the stability of the rf system with a wideband cavity. Then the simplified model in which the loading effect is treated as a reduction in gain of the phase loop is developed. Secondly, the critical damping criteria of the phase loop in the rf system are derived. These criteria give a stability limit appreciably smaller than that given by the Routh-Hurwitz criterion. Finally, we discussed the technique by which the beam loading effect will be compensated. (author)

  10. Kinetic modelling of quantum effects in laser-beam interaction

    CERN Document Server

    Nerush, Evgeny

    2011-01-01

    We present the results of kinetic modelling of quantum effects in laser-beam interaction. In the developed numerical model, electron-positron pair production by hard photons, hard photon emission and the electromagnetic fields generated by the created charged particles are taken into account. Interaction of a relativistic electron beam with a strong laser pulse is analyzed. It is shown that the quantum effects can be important even for moderately intense laser pulses when the number of emitted photons by single electron is not large. Electron-positron pair plasma production in extremely-intense laser field via development of electromagnetic cascades is also studied. The simulation results confirm the prediction of strong laser field absorption in the self-generated electron-positron plasma. It is shown that the self-generated electron-positron plasma can be an efficient source of energetic gamma-quanta.

  11. Study of the transient effects of the space charge compensation on the dynamics of an intense beam

    International Nuclear Information System (INIS)

    A main interest in the design of ion accelerators is the control of the dynamics of intense beams at low energy. This dynamics is dominated by nonlinear effects of the Space Charge (SC) field. This SC field induces a halo formation which can induce losses along the transport. Once ionized by the beam, the residual gas, diffused by the source and produced by the desorption of the vacuum chamber of the accelerator, contributes to the production of electrons and ions. According to their sign of charge compared to the beam, these particles will be repelled or confined. The accumulation of particles in the beam contributes to the compensation of the SC field. However, this neutralization induces other non linearity which are dependent on time. This thesis presents an experimental and theoretical work of the SC compensation for ion beams (H+ and H-). The dynamics of these beams is modelled by a new PIC code, CARTAGO, ensuring the coupling between the created plasma and the studied beams. A single-particle study introduces the dynamics of the plasma in presence of the SC field and of an external magnetic field. The modeling of the compensation with the 1D version of CARTAGO code gave the establishment times and the compensation degrees for several cases of beams and various gas pressures. The compensation of a protons beam was studied more particularly in the low-energy line of the Injector of Protons of High Intensity (IPHI) at Saclay. Simulations show an over-compensation of the space charge inside the focusing solenoid and outside the compensation is only partial. Experimental confrontations of the 2D(r,z) modeling results in a part of this line are also detailed. (author)

  12. Two-photon excitation in living cells induced by low-power cw laser beams

    Science.gov (United States)

    Koenig, Karsten; Krasieva, Tatiana B.; Liu, Yagang; Berns, Michael W.; Tromberg, Bruce J.

    1996-05-01

    We demonstrate multi-photon excitation in optically-trapped living cells. Intracellular non- resonant two-photon excitation of endogenous and exogenous chromophores was induced by CW near infrared (NIR) trapping beams of 105 mW power. In the case of fluorescent chromophores, detection of NIR-excited visible fluorescence was achieved by imaging and spectroscopy methods. Trap-induced, two-photon excited fluorescence was employed as a novel diagnostic method to monitor intracellular redox state and cell vitality of single motile spermatozoa and Chinese hamster ovary cells. We found, that nonlinear absorption of NIR photons NIR, single-frequency traps (`optical tweezers') for micromanipulation of vital cells.

  13. QuickPol: Fast effective beam matrices calculation for CMB polarization

    CERN Document Server

    Hivon, Eric; Ponthieu, Nicolas

    2016-01-01

    Current and planned observations of the Cosmic Microwave Background (CMB) polarization anisotropies, with their ever increasing number of detectors, have reached a potential accuracy that requires a very demanding control of systematic effects. While some of these systematics can be reduced in the design of the instruments, others will be have to be modeled and hopefully accounted for or corrected a posteriori. We propose QuickPol, a quick and accurate calculation of the full effective beam transfer function and of temperature to polarization leakage at the power spectra level, as induced by beam imperfections and mismatches between detector optical and electronic responses. All the observation details such as exact scanning strategy, imperfect polarization measurements and flagged samples are accounted for. Our results are validated on Planck-HFI simulations. We show how the pipeline can be used to propagate instrumental uncertainties up to the final science products, and could be applied to experiments with...

  14. Effect of electron beam irradiation on surgical rubber gloves

    International Nuclear Information System (INIS)

    This paper outlines the effects of electron beam irradiation on surgical rubber gloves. The tensile strength, elongation at break and modulus were evaluated as function of dose range 20-100 kGy minimum dose, dose uniformity ratio, 3.1, and both, accelerated and normal aging, were used to study the stability of the irradiated gloves after irradiation. The surgical gloves were found to be useful up to the highest dose tested. (orig.)

  15. Effect of electron beam irradiation on surgical rubber gloves

    Science.gov (United States)

    Thevy Ratnam, Chantara; Zaman, Khairul

    1998-04-01

    This paper outlines the effects of electron beam irradiation on surgical rubber gloves. The tensile strength, elongation at break and modulus were evaluated as function of dose range 20-100 kGy minimum dose, dose uniformity ratio, 3.1, and both, accelerated and normal aging, were used to study the stability of the irradiated gloves after irradiation. The surgical gloves were found to be useful up to the highest dose tested.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

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

  18. Radiation effects of electron-beam metal depositions on IGFET's

    International Nuclear Information System (INIS)

    Electron-beam radiation effects on n-channel IGFET parameters were studied. This paper summarizes the resulting surface- and dielectric-radiation effects obtained with a series of experiments incorporating e-gun metal deposition on MOS, MNOS, and SNOS structures. The results are compared with those using resistance-heated metal deposition for various thin-film compositions between the metal and silicon surfaces. A comparison is also made with the effects of controlled direct e-beam irradiation of the structures. The efficiency of quartz and aluminum thin films over MNOS structures, in reducing e-gun radiation effects, is evaluated for double-level metallurgy structures. The effect of different thermal-annealing conditions for offsetting the radiation effects is determined. It is concluded that e-gun metallization causes large negative voltage shifts in MOS, MNOS, and SNOS devices. While MOS threshold shifts are fully ''annealable'', residual MNOS and SNOS V/sub T/ shifts are observed after an anneal of 3500/4500C. Thin films of quartz and aluminum over MOS and MNOS structures effectively reduce radiation effects. Other IGFET parameters are not substantially affected by e-gun radiation

  19. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100)

    Science.gov (United States)

    Schirmer, M.; Walz, M.-M.; Vollnhals, F.; Lukasczyk, T.; Sandmann, A.; Chen, C.; Steinrück, H.-P.; Marbach, H.

    2011-02-01

    We have investigated the lithographic generation of TiOx nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.

  20. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100)

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, M; Walz, M-M; Vollnhals, F; Lukasczyk, T; Sandmann, A; Steinrueck, H-P; Marbach, H [Lehrstuhl fuer Physikalische Chemie II and Interdisciplinary Center for Molecular Materials (ICMM), Universitaet Erlangen-Nuernberg, Egerlandstrasse 3, D-91058 Erlangen (Germany); Chen, C, E-mail: marbach@chemie.uni-erlangen.de [Department of Chemistry, Stanford University, Stanford, CA 94305 (United States)

    2011-02-25

    We have investigated the lithographic generation of TiO{sub x} nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.

  1. Ion beam induced crystallization of amorphous Si from NiSi2 precipitates: An in situ study

    International Nuclear Information System (INIS)

    By first growing NiSi2 precipitates in a-Si and then irradiating with a 150 keV Si beam, the authors have studied ion beam induced epitaxial crystallization (IBIEC) of Si initiated at a-Si/NiSi2 precipitate interfaces. The growth shape and its temperature dependence are studied in-beam via in situ transmission electron microscopy. Interface roughening is evidenced. Preliminary results for the Co-Si system are also reported

  2. The dose delivery effect of the different Beam ON interval in FFF SBRT: TrueBEAM

    Science.gov (United States)

    Tawonwong, T.; Suriyapee, S.; Oonsiri, S.; Sanghangthum, T.; Oonsiri, P.

    2016-03-01

    The purpose of this study is to determine the dose delivery effect of the different Beam ON interval in Flattening Filter Free Stereotactic Body Radiation Therapy (FFF-SBRT). The three 10MV-FFF SBRT plans (2 half rotating Rapid Arc, 9 to10 Gray/Fraction) were selected and irradiated in three different intervals (100%, 50% and 25%) using the RPM gating system. The plan verification was performed by the ArcCHECK for gamma analysis and the ionization chamber for point dose measurement. The dose delivery time of each interval were observed. For gamma analysis (2%&2mm criteria), the average percent pass of all plans for 100%, 50% and 25% intervals were 86.1±3.3%, 86.0±3.0% and 86.1±3.3%, respectively. For point dose measurement, the average ratios of each interval to the treatment planning were 1.012±0.015, 1.011±0.014 and 1.011±0.013 for 100%, 50% and 25% interval, respectively. The average dose delivery time was increasing from 74.3±5.0 second for 100% interval to 154.3±12.6 and 347.9±20.3 second for 50% and 25% interval, respectively. The same quality of the dose delivery from different Beam ON intervals in FFF-SBRT by TrueBEAM was illustrated. While the 100% interval represents the breath-hold treatment technique, the differences for the free-breathing using RPM gating system can be treated confidently.

  3. Evaluation of the specific damage induced by heavy-ion beams on human hematopoiesis

    International Nuclear Information System (INIS)

    To clarify the effects of X-ray or heavy-ion beams on the myeloid differentiation pathways from hematopoietic stem/progenitor cells (HSPCs), the CD34''+ cells derived from human placental/umbilical cord blood were exposed to X-irradiation (0.5 Gy and 1.5 Gy) or monoenergetic carbon-ion beams (linear energy transfer (LET)=50 keV/μm, 0.5 Gy and 1.5 Gy), and then were assayed for their surviving fraction stimulated with five cytokine combination (G-CSF + GM-CSF + IL-3 + SCF + EPO). In addition, the exposed cells were cultured in serum-free medium supplemented with same cytokine for 14 days. The total progenitor cells, colony-forming cells (CFC) including granulocyte-macrophage progenitors, erythroid progenitors and granulocyte-erythroid-macrophage-megakaryocyte progenitors were assessed. All progenitors were far more sensitive to carbon-ion beams than to X-rays. In addition, the number of total mononuclear cells that could be expanded by liquid culture was significantly decreased in carbon-ion beam-irradiated cells compared to X-irradiated cells. However, no significant difference was observed in the cell surface antigens expressed on the generated cells derived from X-irradiated cells and carbon-ion beam-irradiated cells. These results showed that carbon-ion beams inflicted severe damage on their clonogenic potential of myeloid HSPCs; however, no significant influence was observed on the differentiation pathway. (author)

  4. Electron-beam induced structural and function change of microbial peroxiredoxin

    International Nuclear Information System (INIS)

    Pseudomonas aerogenes peroxiredoxin (PaPrx) has dual functions acting as thioredoxin (Trx)-dependent peroxidase and molecular chaperone. The function of PaPrx is controlled by its structural status. In this study, we examined the effect of electron beam on structural modification related to chaperone activity. When irradiated electron beam at 1 kGy, the structural and functional changes of PaPrx were initiated. The enhanced chaperone activity was increased about 3- 40 4-fold at 2 kGy compared with non-irradiated, while the peroxidase activity was decreased. We also investigated the influence of the electron beam on protein physical property factors such as hydrophobicity and secondary structure. The exposure of hydrophobic domains reached a peak at 2 kGy of electron beam and then dose-dependently decreased with increasing electron beam irradiation. In addition, the electron beam irradiated PaPrx significantly increased exposure of β-sheet and random coil elements on the protein surface whereas exposure of α-helix and turn elements was decreased. Our results suggest that highly enhanced chaperone activity could be applied to use in bio-engineering system and various industrial applications

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

    International Nuclear Information System (INIS)

    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.

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

    Science.gov (United States)

    Aytaç, Ayşe; Deniz, Veli; Şen, Murat; Hegazy, El-Sayed; Güven, Olgun

    2010-03-01

    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.

  7. Infrared Polarization and Beaming Effect for BL Lac Objects

    Institute of Scientific and Technical Information of China (English)

    MEI Dong-Cheng; XIE Guang-Zhong

    2001-01-01

    With the idea of the beaming models, we derive a relation between the observed polarization and Dopplercorrected magnitude; that is, the observed polarization is in anti-correlation with the Doppler-corrected magnitude. Making use of the infrared data observed simultaneously by Impey et al. [Mon. Not. R. Astron. Soc.200 (1982) 19; 209 (1984) 245] and Holmes et al. [ibid. 210 (1984) 961] we found that: (1) there is a significant correlation between the observed maximum polarization and Doppler-corrected magnitude but the polarization is not in anti-correlation with the Doppler-corrected magnitude; (2) the maximum infrared polarization is strongly correlated with the maximum optical polarization. Our conclusion is that the infrared polarization depends only on the degree of ordering of the magnetic field in the synchrotron emission regions and not on the beaming effect.Both infrared and optical emissions originate from the synchrotron radiation.

  8. Beam-Shape Effects in Nonlinear Compton and Thomson Scattering

    CERN Document Server

    Heinzl, T; Kämpfer, B

    2009-01-01

    We discuss intensity effects in collisions between beams of optical photons from a high-power laser and relativistic electrons. Our main focus are the modifications of the emission spectra due to realistic finite-beam geometries. By carefully analyzing the classical limit we precisely quantify the distinction between strong-field QED Compton scattering and classical Thomson scattering. A purely classical, but fully covariant, calculation of the bremsstrahlung emitted by an electron in a plane wave laser field yields radiation into harmonics, as expected. This result is generalized to pulses of finite duration and explains the appearance of line broadening and harmonic substructure as an interference phenomenon. The ensuing numerical treatment confirms that strong focussing of the laser leads to a broad continuum while higher harmonics become visible only at moderate focussing, hence lower intensity. We present a scaling law for the backscattered photon spectral density which facilitates averaging over electro...

  9. Effects on focused ion beam irradiation on MOS transistors

    International Nuclear Information System (INIS)

    The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 μm minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga+ focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated

  10. Effects of modulated electron beams and cavities on reditrons

    Science.gov (United States)

    Kwan, T. J. T.; Davis, H. A.; Fulton, R. D.; Sherwood, E. G.

    The virtual cathode, when formed in a cavity, can generate microwaves at different cavity modes depending on the geometry of the cavity. We found that the formation and the oscillation frequency of the virtual cathode in a reditron can be significantly influenced by cavity designs. The length of a cavity can play a role in frequency and mode selection. Our simulations showed that TM sub 012 and TM sub 033 were excited for cavity lengths of 15.0 cm and 22.5 cm, respectively. In addition to the cavity effects on reditrons, we discovered that highly modulated electron beams can be produced in reditrons. Full modulation (100 percent) of the transmitted electron beam current has been confirmed in our simulations. We further showed that incorporation of an inverse diode configuration can achieve microwave production efficiency of 26 percent.

  11. Effects of modulated electron beams and cavities on reditrons

    Energy Technology Data Exchange (ETDEWEB)

    Kwan, T.J.T.; Davis, H.A.; Fulton, R.D.; Sherwood, E.G.

    1988-01-01

    The virtual cathode, when formed in a cavity, can generate microwaves at different cavity modes depending on the geometry of the cavity. We found that the formation and the oscillation frequency of the virtual cathode in a reditron can be significantly influenced by cavity designs. The length of a cavity can play a role in frequency and mode selection. Our simulations showed that TM/sub 012/ and TM/sub 033/ were excited for cavity lengths of 15.0 cm and 22.5 cm, respectively. In addition to the cavity effects on reditrons, we discovered that highly modulated electron beams can be produced in reditrons. Full modulation (100/percent/) of the transmitted electron beam current has been confirmed in our simulations. We further showed that incorporation of an inverse diode configuration can achieve microwave production efficiency of 26/percent/. 11 refs., 8 figs.

  12. Effects on focused ion beam irradiation on MOS transistors

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, A.N.; Peterson, K.A.; Fleetwood, D.M.; Soden, J.M.

    1997-04-01

    The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 {mu}m minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga{sup +} focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated.

  13. Multiharmonic rf feedforward system for compensation of beam loading and periodic transient effects in magnetic-alloy cavities of a proton synchrotron

    Science.gov (United States)

    Tamura, Fumihiko; Ohmori, Chihiro; Yamamoto, Masanobu; Yoshii, Masahito; Schnase, Alexander; Nomura, Masahiro; Toda, Makoto; Shimada, Taihei; Hasegawa, Katsushi; Hara, Keigo

    2013-05-01

    Beam loading compensation is a key for acceleration of a high intensity proton beam in the main ring (MR) of the Japan Proton Accelerator Research Complex (J-PARC). Magnetic alloy loaded rf cavities with a Q value of 22 are used to achieve high accelerating voltages without a tuning bias loop. The cavity is driven by a single harmonic (h=9) rf signal while the cavity frequency response also covers the neighbor harmonics (h=8,10). Therefore the wake voltage induced by the high intensity beam consists of the three harmonics, h=8,9,10. The beam loading of neighbor harmonics is the source of periodic transient effects and a possible source of coupled bunch instabilities. In the article, we analyze the wake voltage induced by the high intensity beam. We employ the rf feedforward method to compensate the beam loading of these three harmonics (h=8,9,10). The full-digital multiharmonic feedforward system was developed for the MR. We describe the system architecture and the commissioning methodology of the feedforward patterns. The commissioning of the feedforward system has been performed by using high intensity beams with 1.0×1014 proteins per pulse. The impedance seen by the beam is successfully reduced and the longitudinal oscillations due to the beam loading are reduced. By the beam loading compensation, stable high power beam operation is achieved. We also report the reduction of the momentum loss during the debunching process for the slow extraction by the feedforward.

  14. Stiction of a Nano-Beam with Surface Effect

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Lin; XIA Re; ZHOU Yue-Ting

    2011-01-01

    Nanowire stiction is a cruciai bottleneck for the development of M/NEMS devices. We present a model of a nano-beam stuck to te substrate in consideration of both surface elasticity and residual surface stress. The critical detachment length can be derived from the transversality condition using the variational method. The effects of the surface parameters on the adhesion of the nano-beam are discussed in detail. These analyses provide some suggestions for engineers in the design and fabrication of more accurate M/NEMS instruments.%Nanowire stiction is a crucial bottleneck for the development of M/NEMS devices.We present a model of a nano-beam stuck to the substrate in consideration of both surface elasticity and residual surface stress.The critical detachment length can be derived from the transversality condition using the variational method.The effects of the surface parameters on the adhesion of the nano-beam are discussed in detail.These analyses provide some suggestions for engineers in the design and fabrication of more accurate M/NEMS instruments.In the bottom-up approach,nanowires and nanobelts are widely used as the building blocks of micro/nano devices,such as micro-sensors,resonators,probes,transistors and actuators in micro/nanoelectro-mechanical systems (M/NMES).[1-3] Unfortunately,the stiction failure caused by spontaneous adhesion between M/NEMS structures has become a major limitation to push better application of these novel devices and this problem has been highlighted as a hot topic in the past decades.[4,5] The main reason of stiction is that in the small spacings,slender structures with high compliance are easily brought into contact with a substrate with strong surface energy.

  15. Effect of Construction Joints on Performance of Reinforced Concrete Beams

    Directory of Open Access Journals (Sweden)

    Zena Waleed Abass

    2012-01-01

    Full Text Available Construction joints are stopping places in the process of placing concrete, and they are required because in many structures it is impractical to place concrete in one continuous operation. The amount of concrete that can be placed at one time is governed by the batching and mixing capacity and by the strength of the formwork. A good construction joint should provide adequate flexural and shear continuity through the interface.In this study, the effect of location of construction joints on the performance of reinforced concrete structural elements is experimentally investigated. Nineteen beam specimens with dimensions of 200×200×950 mm were tested. The variables investigated are the location of the construction joints (at midspan or at third point of the specimens, type of construction joints (vertical, inclined, and key construction joints, and presence of stirrups at these joints. The specimens were tested using 1000 kN computer controlled versatile electronic testing machine. The specimens were positioned in the machine so that the deflection at center andor at the location of construction joint was measured at each load step.The results of the experimental program indicated that the best location of the construction joint is at the point of minimum shear. It was found that the use of vertical construction joint has little effect on the overall behavior of beam specimens (the percentage of reduction in ultimate load capacity is in the range of 0% - 5%. While inclined construction joints results in a noticeable reduction in strength of beams relative to the strength of beam without construction joint the percentage of reduction in ultimate load capacity is in range of 8% - 20%.The presence of stirrups at the construction joints is an important variable, which affect the type of failure and load carrying capacity. It is found that adding of stirrups across the joint results in an increase in capacity in the range of (7%- 15% and a decrease in

  16. Effects of tidal forces on the beam energy in LEP

    International Nuclear Information System (INIS)

    The e+e- collider LEP is used to investigate the Z particle and to measure its energy and width. This requires energy calibrations with ∼20 ppm precision achieved by measuring the frequency of a resonance which destroys the transverse beam polarization established by synchrotron radiation. To make this calibration valid over a longer period all effects causing an energy change have to be corrected for. Among those are the terrestrial tides due to the Moon and Sun. They move the Earth surface up and down by as much as ∼0.25 m which represents a relative local change of the Earth radius of 0.04 ppm. This motion has also lateral components resulting in a change of the LEP circumference (Cc=26.7 km) by a similar relative amount. Since the length of the beam orbit is fixed by the constant RF-frequency the change of the machine circumference will force the beam to go off-center through the quadrupoles and receive an extra deflection leading to an energy change given by ΔCc/Cc ∼ -αc ΔE/E. With the momentum compaction αc = 1.85 · 10-4 for the present LEP optics this gives tide-driven p.t.p. energy excursion up to about 220 ppm, corresponding to ∼18.5 MeV for the Z energy. A beam energy measurement carried out over a 24 hour period perfectly confirmed the effects expected from a more detailed calculation of the tides. A corresponding correction can be applied to energy calibrations

  17. Assessment of the effect of beam modifiers on skin dose for external beam radiotherapy using Gafchromic EBT2 film

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the effect of different beam modifiers on the skin dose for 60Co and 15 MV photon beams. Skin doses were measured for solid water (PMMA) phantoms with Gafchromic films. It was observed that, skin dose for all the beam modifiers as well as that for the open beams increases as field size increases. At SSD of 80 cm, skin doses for 10 x 10 cm2 and 25 x 25 cm2 were, 36.9%, and 61.8% respectively for the 60Co unit. It was observed that, for a particular field size, skin dose for the 15 MV photon beam was much lower than that for 60Co beam, which gives an advantage of using the 15 MV photon beam over 60Co beam. As SSD increases skin dose reduces for both 60Co and 15 MV photon beams. For wedged fields (with 600 motorized wedge, it was found that there were very little effects on skin dose for smaller fields but significant effects for the larger fields (≥15 x 15 cm2) as compared with open beams for the 15 MV photon beam. Skin dose for bolus was higher compared with that of open beam and were 57.4% and 73.8% for 10 x 10 cm2 and 20 x 20 cm2 at 100 cm SSD respectively. For 60Co beam, the physical wedges and the 1.5 cm thickness compensator greatly reduced skin doses as compared to all the other beam modifiers. The skin doses for 10 × 10 cm2 field were 21.3%, 19.4%, 18.7%, 19.1% and 23.6% for 150, 300, 450, 600 and the 1.5 cm thickness compensators respectively, at SSD of 80 cm). These compared with 35.4% and 33.7% for the tray and open fields at the same SSD and field size as those for the wedges and compensator above. Skin doses reduced as the compensator thickness was increased. (au)

  18. Effects of beam and pulse trawling on the benthic ecosystem

    OpenAIRE

    Teal, L.R.; Depestele, J.; O'Neill, B; Craeymeersch, J.A.M.; Denderen, van, A.C.; Parker, R.; Perdon, K.J.; H. POLET; Rasenberg, M.M.M.; Vanelslander, B.; Rijnsdorp, A.D.

    2014-01-01

    Here we study the effects of fishing trawl gear on the seabed and benthic organisms. A BACI-design experiment was used to examine the effects of a traditional beam trawl gear and the pulse trawl gear. The pulse trawl gear is gaining popularity amongst Dutch fishers in recent years due to reduced fuel costs and good sole catches.The research was carried out in the northern part of the Dutch Voordelta (southern North Sea coastal zone area, 15 – 22m deep, sandy habitat) in June 2013. In this exp...

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

    International Nuclear Information System (INIS)

    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.

  20. 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...

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

    Science.gov (United States)

    Schulte-Borchers, Martina; 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.

  2. Search for multibody nuclear reactions in metal deuteride induced with ion beam and electrolysis methods

    International Nuclear Information System (INIS)

    We report here the experimental results suggesting the occurrence of multibody nuclear reactions in metal deuterides under ion-beam irradiation and electrolysis. A meaningful increase of helium-4 was observed during electrolysis with the Pd-D2O system, while neutron emission was not observed. The D + D + D fusion, 3D → t + 3He + 9.5 MeV, has been observed repeatedly in deuteron-beam irradiation experiments with a TiDχ target. On the other hand, in proton-beam experiments with TiDχ, H + D + D-fusion: H + D + D → p + 4He + 23.8 MeV was observed. Considering this result, it seems that the 3D reaction occurred between two deuterons trapped closely in TiDχ and an incident particle of deuteron. The multibody nuclear reaction model can interpret both the results obtained in electrolysis and ion-beam experiments. It is considered that the lattice dynamics of metal deuteride is of key importance for inducing short-transient and closely packed d-d pairs and, thus, such fusions. (author)

  3. Vacuum and beam pipe considerations. Pt.1, 2

    International Nuclear Information System (INIS)

    A high vacuum will be required in a KAON factory to reduce scattering, beam-induced multipactoring, beam neutralization, and beam-induced desorption. The TRIUMF KAON group has let contracts for the development of ceramic pipes with rf shields. Analysis of the effect of beam spill on the temperature of the ceramic pipe has been started

  4. 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.

  5. Correction of beam-steering effects in low-velocity superconducting quarter-wave cavities

    International Nuclear Information System (INIS)

    Superconducting cavities presently used for acceleration of ions in velocity range ∼0.01c to 0.3c (where c is the speed of light) are based on quarter-wave resonators. Currently there are several design proposals in nuclear physics laboratories for application of this type of cavity for acceleration of light and heavy ions. The operating frequencies of the cavities range from ∼50 to 360 MHz to satisfy various specifications. Electrodynamics studies of the field distributions in the beam-cavity interaction area indicate appreciable dipole components of both electric and magnetic fields, especially for higher-frequency cavities. The dipole fields induce beam steering, which is a strong function of rf phase and which couples the longitudinal and transverse motion. This can result in growth in the transverse emittance of the beam. In this paper, we propose two possible methods for the correction of such dynamic beam-steering effects in quarter-wave resonators. We analyze and discuss the correction methods for the particular examples of two quarter-wave resonators operating at 57.5 and 115 MHz designed for the driver linac of the Rare Isotope Accelerator facility.

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

    International Nuclear Information System (INIS)

    We have grown graphene by chemical vapor deposition (CVD) and transferred it onto Si/SiO2 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/cm2) 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.

  7. Biological effects of clustered DNA damage produced by heavy ion beams with its complexity

    International Nuclear Information System (INIS)

    Heavy ion beams produce denser ionized region around their track, and cause accumulated damage cluster in the target DNA molecule, termed ''clustered DNA damage.'' Although any ionizing radiations can generate clustered DNA damage with respective degree, heavy ion beam might very effectively produce clustered DNA damage for a reason as mentioned thereinbefore. However, we have less knowledge about molecular mechanism how clustered DNA damage is involved in the degree of biological consequence, and relationship between the species of ionizing radiation and the result. Our previous in vitro study showed that the yields of clustered DNA damage in the target DNA was in inverse proportion to the linear energy transfer (LET) of irradiated radiation (J. Radiat. Res., 49; 133-146, 2008). This result suggests that the yield is not simply responsible to the biological consequence. Therefore, we focused on the structure of clustered DNA damage induced by heavy ion beams in this study. We evaluated the number of damaged site in the designed target oligonucleotides irradiated by gamma-rays, carbon ions and iron ions beams. Also, we estimated the intracellular yields of clustered DNA damage consisted of oxidative base lesions (clustered base damage), because we investigated only DSB not clustered base damage in the previous study. (author)

  8. Investigation of focused ion beam induced damage in single crystal diamond tools

    International Nuclear Information System (INIS)

    Highlights: • The FIB-induced damage layer should be paid enough attention when shaping the cutting edges of nanoscale diamond tools. • During FIB processing cutting tools made of natural single crystal diamond, the Ga+ collision will create a damage layer around tool tips. • The thicknesses of damaged layer and the level for amorphization of diamond significantly increase with beam energy. • The FIB-induced doping and defects during tool fabrication are responsible for the early detection of tool wear of nanoscale diamond tools. - Abstract: In this work, transmission electron microscope (TEM) measurements and molecular dynamics (MD) simulations were carried out to characterise the focused ion beam (FIB) induced damage layer in a single crystal diamond tool under different FIB processing voltages. The results obtained from the experiments and the simulations are in good agreement. The results indicate that during FIB processing cutting tools made of natural single crystal diamond, the energetic Ga+ collision will create an impulse-dependent damage layer at the irradiated surface. For the tested beam voltages in a typical FIB system (from 8 kV to 30 kV), the thicknesses of the damaged layers formed on a diamond tool surface increased from 11.5 nm to 27.6 nm. The dynamic damage process of FIB irradiation and ion–solid interactions physics leading to processing defects in FIB milling were emulated by MD simulations. The research findings from this study provide the in-depth understanding of the wear of nanoscale multi-tip diamond tools considering the FIB irradiation induced doping and defects during the tool fabrication process

  9. Electron beam radiation effects on recycled polyamide-6

    International Nuclear Information System (INIS)

    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

  10. Study of muon-induced neutron production using accelerator muon beam at CERN

    International Nuclear Information System (INIS)

    Cosmogenic muon-induced neutrons are one of the most problematic backgrounds for various underground experiments for rare event searches. In order to accurately understand such backgrounds, experimental data with high-statistics and well-controlled systematics is essential. We performed a test experiment to measure muon-induced neutron production yield and energy spectrum using a high-energy accelerator muon beam at CERN. We successfully observed neutrons from 160 GeV/c muon interaction on lead, and measured kinetic energy distributions for various production angles. Works towards evaluation of absolute neutron production yield is underway. This work also demonstrates that the setup is feasible for a future large-scale experiment for more comprehensive study of muon-induced neutron production

  11. 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.

  12. Study on energetic ion beam irradiation induced magnetism and lattice structure by using synchrotron X-ray

    International Nuclear Information System (INIS)

    FeRh alloy has peculiar magnetic properties such that at temperatures slightly above room temperature, it performs first-order transition to the ferromagnetic property of high-temperature phase from the antiferromagnetic property of constant-temperature phase without changing its crystal structure. The measurements based on extended X-ray absorption fine structure (EXAFS), X-ray magnetic circular dichroism (XMCD), in particular photoelectron emission microscope (PEEM), which use synchrotron radiation, clarified that the two-dimensional micro-magnetic pattern of micrometer scale with various induced shapes and magnetization sizes were formed on the FeRh surface with good control. This study is one of the quantum beam fusion researches to modify and control the properties of substances with ion beams, and evaluate the properties with synchrotron radiation. In the future, the authors will clarify the ion beam irradiation effects of metallic materials other than FeRh alloys and ceramic materials based on synchrotron radiation measurement, and thus elucidate the basic processes that will lead to the development of material processing technology. (A.O.)

  13. Modelling beam transport and biological effectiveness to develop treatment planning for ion beam radiotherapy

    CERN Document Server

    Grzanka, Leszek

    2014-01-01

    Radiation therapy with carbon ions is a novel technique of cancer radiotherapy, applicable in particular to treating radioresistant tumours at difficult localisations. Therapy planning, where the medical physicist, following the medical prescription, finds the optimum distribution of cancer cells to be inactivated by their irradiation over the tumour volume, is a basic procedure of cancer radiotherapy. The main difficulty encountered in therapy planning for ion radiotherapy is to correctly account for the enhanced radiobiological effectiveness of ions in the Spread Out Bragg Peak (SOBP) region over the tumour volume. In this case, unlike in conventional radiotherapy with photon beams, achieving a uniform dose distribution over the tumour volume does not imply achieving uniform cancer cell inactivation. In this thesis, an algorithm of the basic element (kernel) of a treatment planning system (TPS) for carbon ion therapy is developed. The algorithm consists of a radiobiological part which suitably corrects for ...

  14. Lens effect of unipolar electrostatic steerers on low-energy ion beams and its effective reduction

    International Nuclear Information System (INIS)

    The JAEA-Tokai tandem accelerator has two ion injectors, one is the negative ion injector placed on the ground and the other is the positive ion injector in the high voltage terminal. The electrostatic steerers in the high voltage terminal are used for ion beams from the both injectors. Because the beams from the negative ion injector gain high energy at the 20MV terminal, the electrodes of the electrostatic steerers are designed to be supplied several ten kV. The high voltages are supplied by two unipolar DC power supplies and they are controlled as the sum of the voltages keeps constant. The high electric potential between the electrodes affects the beam trajectory as an electrostatic lens. The potential must be too high for the low energy ion beams from the positive ion injector on the 100kV deck. We simulated the beam trajectory by calculation and evaluated the strength of the lens effects. The results showed that the focal distances were too short to control the beam form positive ion injector using optical devices in the downstream. If we reduce the voltages to one tenth in simulation, then the focusing effects were much less significant. We installed a multiplying factor circuit to make the voltages variable and much lower. The results of beam-handling tests using the circuit actually showed significant increase of the ion beam current. (author)

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

    International Nuclear Information System (INIS)

    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, γopt ∼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. 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.

  17. Electron beam irradiation effects on some packaged dried food items

    International Nuclear Information System (INIS)

    For radical sports practitioners, small nutritious snack foods are needed. At the same time, food preparation must guarantee long shelf life and be compact or lightweight for easiness of carrying. Commercial individually packaged foods can be used either for sports practitioners like adventure racing or eventually as military rations. Irradiation processing of foods is an important preservation technology. High-voltage electron beams generated from linear accelerators are an alternative to radioisotope generators as they require much shorter exposure times (seconds vs. hours for γ irradiation) to be effective and are currently used to pasteurize meat products among others food items. This work describes the application of electron beam irradiation on some food items used in sport training diets: fiber rich cookies, fruit cereal bars, instant dehydrated asparagus soup and instant Brazilian corn pudding. Each kind of sample contained 3 groups of 15 units each. Irradiation was performed with an electron beam accelerator Dynamitron (Radiation Dynamics Inc.) model JOB 188, with doses of 5 and 10 kGy. For the evaluation of irradiated samples a methodology based on the Analytical Norms of the Instituto Adolfo Lutz, one of the South America Reference Laboratories was employed. The microbiological and sensory analyses of the diverse irradiated samples are presented. Electron beam irradiation resulted in significant reduction of the fungus and yeast load but caused dose dependent differences of some sensory characteristics. A careful dose choice and special irradiation conditions must be used in order to achieve sensory requirements needed for the commercialization of these irradiated food items. (author)

  18. 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.

  19. 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.

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

    Science.gov (United States)

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

    2006-05-01

    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.

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

    International Nuclear Information System (INIS)

    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

  2. Studies of Beam Induced Electron Cloud Resonances in Dipole Magnetic Fields

    CERN Document Server

    Calvey, J R; Makita, J; Venturini, M

    2016-01-01

    The buildup of low energy electrons in an accelerator, known as electron cloud, can be severely detrimental to machine performance. Under certain beam conditions, the beam can become resonant with the cloud dynamics, accelerating the buildup of electrons. This paper will examine two such effects: multipacting resonances, in which the cloud development time is resonant with the bunch spacing, and cyclotron resonances, in which the cyclotron period of electrons in a magnetic field is a multiple of bunch spacing. Both resonances have been studied directly in dipole fields using retarding field analyzers installed in the Cornell Electron Storage Ring (CESR). These measurements are supported by both analytical models and computer simulations.

  3. 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; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brown, Gareth; Brown, Heather; Bruce, Roderik; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchanan, James; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Büscher, Volker; Bugge, Lars; Bulekov, Oleg; Bundock, Aaron Colin; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarri, Paolo; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Cantrill, Robert; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavaliere, Viviana; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerqueira, Augusto Santiago; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chan, Kevin; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Xin; Chen, Yujiao; Cheng, Yangyang; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Ilektra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Cirkovic, Predrag; 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; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dinut, Florin; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; do Vale, Maria Aline Barros; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobos, Daniel; Dobson, Ellie; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dotti, Andrea; Dova, Maria-Teresa; Doxiadis, Alexander; Doyle, Tony; Dressnandt, Nandor; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Dührssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Duguid, Liam; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edson, William; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Fonseca Martin, Teresa; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; 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; Hernandez, Carlos Medina; 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; 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; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pinto, Belmiro; Pizio, Caterina; Plamondon, Mathieu; Pleier, Marc-Andre; Plotnikova, Elena; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przybycien, Mariusz; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radeka, Veljko; Radescu, Voica; Radloff, Peter; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Rauscher, Felix; Rave, Tobias Christian; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reinsch, Andreas; Reisinger, Ingo; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Roe, Adam; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romeo, Gaston; Romero Adam, Elena; Rompotis, Nikolaos; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Anthony; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rosselet, Laurent; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Christian; Rudolph, Gerald; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rumyantsev, Leonid; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruzicka, Pavel; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sanchez, Arturo; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarrazin, Bjorn; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schäfer, Uli; Schaelicke, Andreas; Schaepe, Steffen; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R~Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schneider, Basil; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schultens, Martin Johannes; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Sciolla, Gabriella; Scott, Bill; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Seuster, Rolf; Severini, Horst; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snyder, Scott; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Solovyev, Victor; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soualah, Rachik; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Staude, Arnold; Stavina, Pavel; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Styles, Nicholas Adam; Soh, Dart-yin; Su, Dong; Subramania, Halasya Siva; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Suzuki, Yuta; Svatos, Michal; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Sánchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teinturier, Marthe; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tic, Tomáš; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valentinetti, Sara; Valero, Alberto; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Berg, Richard; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; van Vulpen, Ivo; Vanadia, Marco; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vazquez Schroeder, Tamara; Vegni, Guido; Veillet, Jean-Jacques; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Virzi, Joseph; Vitells, Ofer; Viti, Michele; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wahrmund, Sebastian; Wakabayashi, Jun; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Rui; Wang, Song-Ming; Wang, Tan; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watanabe, Ippei; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Michele; Weber, Pavel; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Wetter, Jeffrey; Weydert, Carole; Whalen, Kathleen; White, Andrew; White, Martin; White, Sebastian; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Wei-Cheng; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wraight, Kenneth; Wright, Michael; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xie, Song; Xu, Chao; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Liwen; Yao, Yushu; Yasu, Yoshiji; Ybeles Smit, Gabriel Valentijn; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zanello, Lucia; Zanzi, Daniele; Zaytsev, Alexander; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Ženiš, Tibor; Zinonos, Zinonas; Zenz, Seth; 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

    2013-01-01

    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...

  4. Transverse shift of a high-order paraxial vortex-beam induced by a homogeneous anisotropic medium

    International Nuclear Information System (INIS)

    We have found the asymmetric splitting of a high-order circularly polarized vortex-beam in a uniaxial crystal. The l-order vortex-beam splits into the same one and the beam with the l-1 vortices at the beam axis while one optical vortex is shifted along the direction perpendicular to the inclination plane of the beam. Such a vortex displacement causes the transverse shift of the partial beam. We consider this effect both in terms of the conservation law of the angular-momentum flux and on the base of the solutions to the paraxial wave equation. We revealed that the transverse shift of the crystal-traveling beam depends on neither a magnitude nor a sign of the vortex topological charge being defined only by a handedness of the initial circular polarization and a sign of the inclination angle of the beam.

  5. 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. PMID:26651700

  6. Ion beam induced adhesion improvement of metal layers - a comparative study on composite layers

    International Nuclear Information System (INIS)

    The adhesion of thin layers of metals like Al, Cu, Cr, Ti etc. on polymer, ceramic or composite substrates is of great importance for microelectronics (printed circuits, packaging), and materials science. Therefore investigations on the adhesion improvement of copper on high temperature thermoplasts, carbon fibre reinforced polymers (CFK) and pure carbon by ion bombardment were undertaken. Ion beam mixing as well as ion beam assisted deposition (IBAD) was applied. It was shown that the electronic stopping power is the most important parameter for adhesion in the case of ion beam mixing by non-reactive ions. Reactive ions, especially metals, add an important chemical effect when stopped near the interface. IBAD Cu-layers have only good adhesion properties when prepared by low energy ion bombardment or with reactive intermediate layers. ((orig.))

  7. 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 Tc=306.6 K and volume fraction ϕc=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.

  8. Development and application of creation technology of new crops by radiation. Induction effect of mutation of flower color of chrysanthemum by 12C5+ ion beam irradiation

    International Nuclear Information System (INIS)

    Dose-effect of cultured explant of chrysanthemum by 12C5+ ion beam irradiation and mutation of flower color induced by redifferentiation individuals were studied. The inductive effect of mutation by ion beam was compared with that of γ-ray. Damage of cultured explant by ion beam irradiation was observed at first at 5 Gy. LD50, LD75 and LD100 were shown by 10 Gy, 20 Gy and 30 Gy dose, respectively. Callus formation and individuals redifferentiation were obtained in explant by dose to 20 Gy. 5-15 Gy seemed to be suitable dose of 12C5+ ion beam to explant of chrysanthemum. On damage by γ-ray, LD50 and LD100 were observed by 45 Gy and 80 Gy, respectively. On the basis of LD50, the biological effect of ion beam was about 4.5 times as large as that of γ-ray. In the case of ''Taihei'', the stock seed, more large amount of multi color variant was induced by ion-beam, especially, it was remarkable such a case as flower used as explant. Ion beam 12C5+ irradiation induced mutation to multicolors. Both irradiations induced mutation more to flower than to leaf. (S.Y.)

  9. Effects on doppler profiles in beam-heated plasmas

    International Nuclear Information System (INIS)

    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)

  10. The effect of heavy-ion beams for tumor metastases

    International Nuclear Information System (INIS)

    The aim of this study is to clarify the effect of carbon-ion beams (C-ions) for metastatic potential of malignant melanomas. B16/BL6 cells, a mouse malignant melanoma cell line having highly metastatic potential, were exposed to heavy-ion beams (C-ions) or photon beams (X-rays or γ-rays) in vitro or in vivo conditions. Survival curves showed higher cytotoxic effects of C-ions than X-rays. The abilities of migration, invasion and adhesion were significantly suppressed by C-ions with increment of dose and linear energy transfer (LET) values, however a part of those abilities enhanced by X-rays at low dose range (0.5-1.0 Gy) compared with controls. Interestingly, the enhancement ratios for the metastatic potentials, migration, invasion and adhesion were higher than those for cell killing. Local tumors implanted into right leg of mice (7.5±0.5 mm) were irradiated with C-ions (290 MeV/u, 6 cm spread-out Bragg peak (SOBP)) or γ-rays (137Cs). Lung metastatic nodules arise from local tumors was counted as metastasis after irradiation. The metastasis was suppressed by radiations depending on the physical dose, and the effect of C-ions was significant. Additionally, the surviving fraction of each cell in a tumor was obtained by in vivo-in vitro assay, and biological equivalent dose were estimated. C-ions also significantly suppressed metastatic fraction compared with γ-rays when the metastasis was re-analyzed using the equivalent dose. It might suggest that C-ion inhibit metastasis at radiotherapy compared with low-LET photons. (author)

  11. The effects of magnetic fringe fields on beam dynamics in a beam transport line of a terahertz FEL source

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Han [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Xiong, Yongqian, E-mail: yqxiong@mail.hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Pei, Yuanji [National Synchrotron Radiation laboratory, University of Science and Technology of China, Hefei 230029, Anhui (China)

    2014-11-11

    The transport line used in a terahertz FEL device has to transport electron beam through the entire system efficiently and meet the requirements of the beam parameters at the undulator entrance. Due to space limitations, the size of the magnets (five quadrupoles and two bending magnets) employed in the transport line was limited, and some devices were densely packed. In this paper, analyses of the effect of fringe fields and magnetic interference of magnets are presented. 3D models of these magnets are built and their linear optical properties are compared with those obtained by hard edge models. The results indicated that the effects of these factors are significant and they would cause a mismatch of the beam at the exit of the transport line under the preliminary lattice design. To solve this problem, the beam was re-matched using the particle swarm optimization algorithm.

  12. Electron beam radiation effects on recycled polyamide-6

    International Nuclear Information System (INIS)

    The aim of this work was to study the ionizing radiation effects on recycled polyamide-6. This polymer was irradiated with a 1.5 MeV electron beam at different doses. The glass transition of the samples was determined by dynamic mechanical analyses (DMA) measurements and the crystallinity was observed through the X-ray diffraction diagrams. It was observed that crosslinking may have occurred in the irradiated samples of virgin and recycled polyamide-6 and the crystallinity has not changed. (author)

  13. Proximity effect simulation for variable shape e-beam writer

    Czech Academy of Sciences Publication Activity Database

    Kolařík, Vladimír; Matějka, Milan; Urbánek, Michal; Král, Stanislav; Krátký, Stanislav; Mikšík, P.; Vašina, J.

    Brno: Institute of Scientific Instruments AS CR, v.v.i, 2012 - (Mika, F.), s. 75-76 ISBN 978-80-87441-07-7. [International Seminar on Recent Trends in Charged Particle Optics and Surface Physics Instrumentation /13./. Skalský dvůr (CZ), 25.06.2012-29.06.2012] R&D Projects: GA MŠk ED0017/01/01; GA MPO FR-TI1/576 Institutional support: RVO:68081731 Keywords : electron scattering effects * e-beam writer * computer simulation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  14. Coherent beam-beam effects observation and mitigation at the RHIC collider

    Energy Technology Data Exchange (ETDEWEB)

    White S.; Fischer, W.; Luo, Y.

    2012-05-20

    In polarized proton operation in RHIC coherent beam-beam modes are routinely observed with beam transfer function measurements in the vertical plane. With the existence of coherent modes a larger space is required in the tune diagram than without them and stable conditions can be compromised for operation with high intensity beams as foreseen for future luminosity upgrades. We report on experiments and simulations carried out to understand the existence of coherent modes in the vertical plane and their absence in the horizontal plane, and investigate possible mitigation strategies.

  15. Effects of Ga ion-beam irradiation on monolayer graphene

    International Nuclear Information System (INIS)

    The effects of Ga ion on the single layer graphene (SLG) have been studied by Raman spectroscopy (RS), SEM, and field-effect characterization. Under vacuum conditions, Ga ion-irradiation can induce disorders and cause red shift of 2D band of RS, rather than lattice damage in high quality SLG. The compressive strain induced by Ga ion decreases the crystalline size in SLG, which is responsible for the variation of Raman scattering and electrical properties. Nonlinear out-put characteristic and resistance increased are also found in the I-V measurement. The results have important implications during CVD graphene characterization and related device fabrication

  16. Digital IBIC - new spectroscopic modalities for ion-beam-induced charge imaging

    International Nuclear Information System (INIS)

    The first implementation of digital ion-beam-induced charge (IBIC) imaging is presented, which permits spectroscopic time-resolved IBIC imaging of charge transport in semiconductors. A digital IBIC system has been developed which uses a high-speed waveform digitiser to capture the pulse shapes produced by interactions of a 1 μm resolution scanning microbeam in semiconductor samples. Using a variety of digital pulse shape analysis algorithms, quantitative images of charge signal amplitude, charge carrier lifetime, mobility and trapping phenomena can be acquired in real-time, with a time resolution of 3 cm2/Vs

  17. Electron beam induced current measurement on a specimen biased in a cathode lens

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav; Zobač, Martin; Vlček, Ivan

    Graz : Verlag der Technischen Universität, 2009, Vol. 1: 211-212. ISBN 978-3-85125-062-6. [MC 2009 - Joint Meeting of Dreiländertagung and Multinational Congress on Microscopy /9./. Graz (AT), 30.08.2009-04.09.2009] R&D Projects: GA AV ČR IAA100650803 Institutional research plan: CEZ:AV0Z20650511 Keywords : elektron beam induced current * SEM * very low energy electrons * cathode lens * specimen bias Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering http://www.univie.ac.at/asem/Graz_MC_09/papers/77645.pdf

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

    International Nuclear Information System (INIS)

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

  19. Low temperature electron-beam induced voltage contrast in YBCO thin film structures

    International Nuclear Information System (INIS)

    The realisation of high temperature superconducting thin film devices will require superconducting and insulating layered structures which maintain high quality properties. It is desirable to characterise such devices locally to determine limitations in the design or growth processes. The technique of beam-induced voltage contrast, using low temperature scanning electron microscopy, has been utilised to observe spatial variations in superconducting properties of single layer YBa2Cu3O7, Josephson junctions, and a flux transformer spiral. This paper reports on the limiting elements of insulated cross-over arrays and window contacts between superconducting layers. (orig.)

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-08-01

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

  2. Dispersive ground plane core-shell type optical monopole antennas fabricated with electron beam induced deposition.

    Science.gov (United States)

    Acar, Hakkı; Coenen, Toon; Polman, Albert; Kuipers, Laurens Kobus

    2012-09-25

    We present the bottom-up fabrication of dispersive silica core, gold cladding ground plane optical nanoantennas. The structures are made by a combination of electron-beam induced deposition of silica and sputtering of gold. The antenna lengths range from 300 to 2100 nm with size aspect ratios as large as 20. The angular emission patterns of the nanoantennas are measured with angle-resolved cathodoluminescence spectroscopy and compared with finite-element methods. Good overall correspondence between the the measured and calculated trends is observed. The dispersive nature of these plasmonic monopole antennas makes their radiation profile highly tunable. PMID:22889269

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

    International Nuclear Information System (INIS)

    Industrial x-ray computed tomography (CT) systems are being increasingly used as dimensional measuring machines. However, micron level accuracy is not always achievable, as of yet. The measurement accuracy is influenced by many factors, such as the workpiece properties, x-ray voltage, filter, beam hardening, scattering and calibration methods (Kruth et al 2011 CIRP Ann. Manuf. Technol. 60 821–42, Bartscher et al 2007 CIRP Ann. Manuf. Technol. 56 495–8, De Chiffre et al 2005 CIRP Ann. Manuf. Technol. 54 479–82, Schmitt and Niggemann 2010 Meas. Sci. Technol. 21 054008). Since 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 (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 of the surrounding stepped cylinder. Accuracy as well as the effect on the uncertainty determination is discussed. The results are compared with simulations using monochromatic beams in order to have a benchmark which excludes beam hardening effects and x-ray scattering. Furthermore, based on the above results, the authors propose a case-dependent calibration artefact for beam hardening correction and edge offset determination. In the final part of the paper

  4. Non-Fourier Heat Conduction Effects During High-Energy Beam Metalworking

    Institute of Scientific and Technical Information of China (English)

    张海泉; 张彦华; 赵海燕

    2004-01-01

    Non-Fourier heat conduction induced by ultrafast heating of metals with a high-energy density beam was analyzed. The non-Fourier effects during high heat flux heating were illustrated by comparing the transient temperature response to different heat flux and material relaxation times. Based on the hyperbolic heat conduction equation for the non-Fourier heat conduction law, the equation was solved using a hybrid method combining an analytical solution and numerical inversion of the Laplace transforms for a semi-infinite body with the heat flux boundary. Analysis of the temperature response and distribution led to a criterion for the applicability of the non-Fourier heat conduction law. The results show that at a relatively large heat flux, such as greater than 108 W/cm2, the heat-affected zone in the metal material experiences a strong thermal shock as the non-Fourier effects cause a large step increase in the surface temperature. The results provide a method for analyzing transient heat conduction problems using a high-energy density beam, such as electron beam deep penetration welding.

  5. Chemical effects of heavy ion beams on organic materials

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Hitoshi E-mail: koizumih@eng.hokudai.ac.jp; Ichikawa, Tsuneki; Taguchi, Mitsumasa; Kobayashi, Yasuhiko; Namba, Hideki

    2003-05-01

    Effects of ion beam irradiation on {alpha}-alanine, adipic acid and polydimethylsiloxane were examined. Stable radicals were generated in the radiolysis of solids of {alpha}-alanine and adipic acid by {gamma}-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 {alpha}-alanine. The decreases in the G-value are ascribed to high local dose in the ion tracks. Effective G-value of the radicals for {gamma}-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 {gamma}-irradiations. The difference in the dependence of the G-values for {alpha}-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.

  6. A comparative study on the effects of electron beam irradiation on imidacloprid-resistant and -susceptible Aphis gossypii (Hemiptera: Aphididae)

    International Nuclear Information System (INIS)

    The melon and cotton aphid, Aphis gossypii, is a polyphagous insect pest. This study compared the development, reproduction, DNA damage, recovery, and gene expression in imidacloprid-resistant (IMI-R) and -susceptible (S) strains of A. gossypii by electron beam irradiation. When 1st instar nymphs were irradiated with 100 Gy, the fecundity (nymphs of F1 generation) of the resultant adults were completely inhibited. When adults were irradiated with 200 Gy, the number of total 1st instar nymphs produced per adult was 3.0±1.7 and 1.9±1.4 in the S and IMI-R strains, respectively, but adult development was completely suppressed. However, electron beam irradiation did not affect adult longevity in either the S or IMI-R strain. There was no statistically significant difference between the effect of irradiation on the S and IMI-R strains. Therefore, electron beam irradiation at 200 Gy could be used as a phytosanitary irradiation treatment for both S and IMI-R strains of A. gossypii. The DNA damage caused by electron beam irradiation was evaluated by an alkaline comet assay. Exposure to an electron beam (50 Gy) induced DNA damage that was repaired to a similar level as the untreated control group (0 Gy) over time. However, at more than 100 Gy, the DNA damage was not completely repaired. The expression of P450, HSP70, cuticle protein, and elongation factor genes were higher in the IMI-R strain than in the S strain. - Highlights: • Electron beam irradiation induces abnormal development in both the IMI-R and -S strain. • Electron beam irradiation induces DNA damage in both the S and IMI-R strain. • The expression of several specific genes were higher in the IMI-R strain. • 200 Gy could be used as a phytosanitary treatment for both strains of this species

  7. A system for measuring defect induced beam modulation on inertial confinement fusion-class laser optics

    Science.gov (United States)

    Runkel, Mike; Hawley-Fedder, Ruth; Widmayer, Clay; Williams, Wade; Weinzapfel, Carolyn; Roberts, Dave

    2005-12-01

    A multi-wavelength laser based system has been constructed to measure defect induced beam modulation (diffraction) from ICF class laser optics. The Nd:YLF-based modulation measurement system (MMS) uses simple beam collimation and imaging to capture diffraction patterns from optical defects onto an 8-bit digital camera at 1053, 527 and 351 nm. The imaging system has a field of view of 4.5 x 2.8 mm2 and is capable of imaging any plane from 0 to 30 cm downstream from the defect. The system is calibrated using a 477 micron chromium dot on glass for which the downstream diffraction patterns were calculated numerically. Under nominal conditions the system can measure maximum peak modulations of approximately 7:1. An image division algorithm is used to calculate the peak modulation from the diffracted and empty field images after the baseline residual light background is subtracted from both. The peak modulation can then be plotted versus downstream position. The system includes a stage capable of holding optics up to 50 pounds with x and y translation of 40 cm and has been used to measure beam modulation due to solgel coating defects, surface digs on KDP crystals, lenslets in bulk fused silica and laser damage sites mitigated with CO2 lasers.

  8. Coded-aperture imaging using photo-induced reconfigurable aperture arrays for mapping terahertz beams

    CERN Document Server

    Kannegulla, Akash; Rahman, Syed; Fay, Patrick; Xing, Huili Grace; Cheng, Li-Jing; Liu, Lei

    2013-01-01

    We report terahertz coded-aperture imaging using photo-induced reconfigurable aperture arrays on a silicon wafer. The coded aperture was implemented using programmable illumination from a commercially available digital light processing projector. At 590 GHz, each of the array element apertures can be optically turned on and off with a modulation depth of 20 dB and a modulation rate of ~1.3 KHz. Prototype demonstrations of 4 by 4 coded-aperture imaging using Hadamard coding have been performed and this technique has been successfully applied to mapping THz beams by using a 6 by 6 aperture array at 590 GHz. The imaging results agree closely with theoretical calculations based on Gaussian beam transformation, demonstrating that this technique is promising for realizing real-time and low-cost terahertz cameras for many applications. The reported approach provides a simple but powerful means to visualize THz beams, which is highly desired in quasi-optical system alignment, quantum-cascade laser design and characte...

  9. 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 ...

  10. Proton implanted silicon wafers investigated by electron beam induced current measurements

    International Nuclear Information System (INIS)

    Full text: Electron Beam Induced Current (EBIC) is an analysis method used in a Scanning Electron Microscope (SEM) to investigate buried junctions or defects in semiconductors. During an EBIC measurement, the electron beam enters a semiconductor and generates electron-hole pairs. If the charge carriers diffuse into a region where there is a built-in electric eld, such as a pn junction or a Schottky contact, charge separation will occur and a current will flow. This is similar to what happens in a solar cell except in an EBIC measurement the electron-hole pairs are generated by the electron beam instead of by light. We have used EBIC to investigate proton implanted silicon wafers with implantation doses from 1 x 1013 p+/cm2 to 1 x 1015 p+/cm2 and with implantation energies from 500 keV to 5 MeV. The implantation introduces vacancies, silicon interstitials, and hydrogen into the crystal. The sample is then annealed in the temperature range from room temperature to 10000C and defect complexes form. The microscopic structure of these defect complexes is not completely understood. There is a class of oxygen-vacancy defect complexes called thermal donors that are known to act as donors in silicon. Since electron-hole pairs recombine at defects, the EBIC signal is decreased if the charge carriers have to diffuse past defects on their way to the measurement contacts. (author)

  11. Study of Effect of Ion Source Energy Spread on RFQ Beam Dynamics at REX-ISOLDE

    CERN Document Server

    Fraser, M A

    2013-01-01

    With an upgrade to the Electron Beam Ion Source (EBIS) at REX under consideration a study was launched in order to understand the effect of an increased energy spread from the ion source on the beam dynamics of the RFQ. Due to the increased electron beam potential needed to achieve the upgrade’s charge breeding specification it is expected that the energy spread of the beam will increase from today’s estimated value of approximately +-0.1%. It is shown through beam dynamics simulations that the energy spread can be increased to +-1% without significant degradation of the beam quality output by the RFQ.

  12. Nonlinear Interaction of Elliptical Laser Beam with Collisional Plasma: Effect of Linear Absorption

    Science.gov (United States)

    Keshav, Walia; Sarabjit, Kaur

    2016-01-01

    In the present work, nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation. Nonlinear differential equations for the beam width parameters of semi-major axis and semi-minor axis of elliptical laser beam have been set up and solved numerically to study the variation of beam width parameters with normalized distance of propagation. Effects of variation in absorption coefficient and plasma density on the beam width parameters are also analyzed. It is observed from the analysis that extent of self-focusing of beam increases with increase/decrease in plasma density/absorption coefficient.

  13. Focused-electron-beam-induced-deposited cobalt nanopillars for nanomagnetic logic

    Science.gov (United States)

    Sharma, N.; van Mourik, R. A.; Yin, Y.; Koopmans, B.; Parkin, S. S. P.

    2016-04-01

    Nanomagnetic logic (NML) intends to alleviate problems of continued miniaturization of CMOS-based electronics, such as energy dissipation through heat, through advantages such as low power operation and non-volatile magnetic elements. In line with recent breakthroughs in NML with perpendicularly magnetized elements formed from thin films, we have fabricated NML inverter chains from Co nanopillars by focused electron beam induced deposition (FEBID) that exhibit shape-induced perpendicular magnetization. The flexibility of FEBID allows optimization of NML structures. Simulations reveal that the choice of nanopillar dimensions is critical to obtain the correct antiferromagnetically coupled configuration. Experiments carrying the array through a clocking cycle using the Oersted field from an integrated Cu wire show that the array responds to the clocking cycle.

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

    International Nuclear Information System (INIS)

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

  15. Focused-electron-beam-induced-deposited cobalt nanopillars for nanomagnetic logic.

    Science.gov (United States)

    Sharma, N; van Mourik, R A; Yin, Y; Koopmans, B; Parkin, S S P

    2016-04-22

    Nanomagnetic logic (NML) intends to alleviate problems of continued miniaturization of CMOS-based electronics, such as energy dissipation through heat, through advantages such as low power operation and non-volatile magnetic elements. In line with recent breakthroughs in NML with perpendicularly magnetized elements formed from thin films, we have fabricated NML inverter chains from Co nanopillars by focused electron beam induced deposition (FEBID) that exhibit shape-induced perpendicular magnetization. The flexibility of FEBID allows optimization of NML structures. Simulations reveal that the choice of nanopillar dimensions is critical to obtain the correct antiferromagnetically coupled configuration. Experiments carrying the array through a clocking cycle using the Oersted field from an integrated Cu wire show that the array responds to the clocking cycle. PMID:26941232

  16. Relative biological effectiveness (RBE) of proton beams in radiotherapy

    International Nuclear Information System (INIS)

    Treatment planning in proton therapy uses a generic value for the Relative Biological Efficiency (RBE) of 1.1 relative to 60Co 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 137Cs gamma-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for 137Cs 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)

  17. Tractor beams for optical micromanipulation

    Science.gov (United States)

    Yevick, Aaron; Grier, David G.

    2016-03-01

    Tractor beams are traveling waves that transport illuminated objects in the retrograde direction relative to the direction of propagation. The theory of photokinetic effects identifies design criteria for long-range general- purpose tractor beams. These criteria distinguish first-order tractor beams that couple to induced dipole moments from higher-order tractor beams that rely on coupling to higher-order multipole moments to achieve pulling. First-order tractor beams are inherently longer-ranged and operate on a wider variety of materials. We explore the physics of first-order tractor beams in the context of a family of generalized solenoidal waves.

  18. Effects of electron beam irradiation on the structural properties of polylactic acid/polyethylene blends

    International Nuclear Information System (INIS)

    Highlights: •Electron beam irradiation on polyethylene (LDPE) and polylactic acid (PLA) blends. •Irradiated PLA/LDPE blends exhibit structural rearrangement to highly ordered structure. •Irradiated PLA/LDPE matrix extends continuity of polymer matrix with larger fibrils diameter. -- Abstract: The purpose of this research was to investigate the effects of electron beam irradiation on the properties of polylactic acid (PLA) and low density polyethylene (LDPE) blends. The PLA were compounded with 20–80% LDPE and were exposed to electron beam irradiation dosages of 20–120 kGy. The results from gel content and X-ray diffraction analyses showed that the addition of LDPE to PLA effectively increased the gel content and crystallinity. However, an increasing percentage of LDPE reduced the tensile strength and Young’s modulus of the PLA/LDPE samples due to the lower intermolecular bonding of LDPE than of PLA. Moreover, an increase in irradiation dosages gradually decreased the mechanical properties of low-LDPE PLA/LDPE. In contrast, the increasing irradiation dosage enhanced the mechanical properties of higher-LDPE PLA/LDPE. These results indicate that higher amounts of LDPE effectively react with the release of free radicals within the amorphous phase if the blends are subjected to irradiation. The higher amounts of free radicals induce the formation of three-dimensional cross-linked networks in the polymer matrix and thus increase the gel content. The irradiation-induced cross-linking in PLA/LDPE samples improves the mechanical properties and crystallinity by promoting a structural rearrangement of the polymer matrix into a highly ordered structure

  19. Effects of electron beam irradiation on the structural properties of polylactic acid/polyethylene blends

    Energy Technology Data Exchange (ETDEWEB)

    Bee, Soo-Tueen, E-mail: direct.beest@gmail.com [Department of Chemical Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur (Malaysia); Ratnam, C.T. [Radiation Processing Technology Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Sin, Lee Tin, E-mail: direct.tinsin@gmail.com [Department of Chemical Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur (Malaysia); Tee, Tiam-Ting; Wong, Wai-Kien; Lee, Jiuun-Xiang [Department of Chemical Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur (Malaysia); Rahmat, A.R. [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2014-09-01

    Highlights: •Electron beam irradiation on polyethylene (LDPE) and polylactic acid (PLA) blends. •Irradiated PLA/LDPE blends exhibit structural rearrangement to highly ordered structure. •Irradiated PLA/LDPE matrix extends continuity of polymer matrix with larger fibrils diameter. -- Abstract: The purpose of this research was to investigate the effects of electron beam irradiation on the properties of polylactic acid (PLA) and low density polyethylene (LDPE) blends. The PLA were compounded with 20–80% LDPE and were exposed to electron beam irradiation dosages of 20–120 kGy. The results from gel content and X-ray diffraction analyses showed that the addition of LDPE to PLA effectively increased the gel content and crystallinity. However, an increasing percentage of LDPE reduced the tensile strength and Young’s modulus of the PLA/LDPE samples due to the lower intermolecular bonding of LDPE than of PLA. Moreover, an increase in irradiation dosages gradually decreased the mechanical properties of low-LDPE PLA/LDPE. In contrast, the increasing irradiation dosage enhanced the mechanical properties of higher-LDPE PLA/LDPE. These results indicate that higher amounts of LDPE effectively react with the release of free radicals within the amorphous phase if the blends are subjected to irradiation. The higher amounts of free radicals induce the formation of three-dimensional cross-linked networks in the polymer matrix and thus increase the gel content. The irradiation-induced cross-linking in PLA/LDPE samples improves the mechanical properties and crystallinity by promoting a structural rearrangement of the polymer matrix into a highly ordered structure.

  20. Effect of blocking mass on characteristics of beam lateral vibration

    International Nuclear Information System (INIS)

    The lateral vibration equation is established by setting up two separate co-coordinate systems of the mass-beam system, and the non-dimensional coefficients implying the position and mass radio of the mass in the system are presented in the paper. The effect on the vibration frequencies of changing the position and the mass radio in the system is numerically discussed, and the modes of the system with different mass radio and position are considered. The result shows that the frequencies decrease as increasing the mass radio, but the frequencies fluctuate with position changing, and there exists some positions that the frequencies do not vary after the mass radio increases except the first frequency, also that the effects on the vibration characteristic as increasing the mass radio can be decreased by modulating the position of the mass. (authors)

  1. Effective mutagenesis of Arabidopsis by heavy ion beam-irradiation

    International Nuclear Information System (INIS)

    Full text: Arabidopsis researches frequently include the genetic approach, so efficient, convenient, and safe methods for mutagenesis are required. Currently, the most popular method for in house mutagenesis is application of EMS. Although this method is very effective, its base substitution-type mutations often gives leaky mutants with residual gene functions, leading some difficulty in understanding the corresponding gene functions. Heavy ion beam generated by accelerators gives highest energy transfer rates among known radiation-based mutagenesis methods including X ray, gamma ray, fast neutron, electron and proton irradiation. This feature is thought to give high frequency of the double strand break of genomic DNA and resultant short deletions, resulting frame shift-type mutations. At RIKEN Accelerator Research Facility (RARF, http://www.rarf.riken.go.jp/index-e.html), we have optimized conditions for effective mutagenesis of Arabidopsis regarding to ion species and irradiation dose, and achieved comparable mutation rates to the method with EMS. (author)

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

    International Nuclear Information System (INIS)

    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

  3. Direct-Write Fabrication of Cellulose Nano-Structures via Focused Electron Beam Induced Nanosynthesis.

    Science.gov (United States)

    Ganner, Thomas; Sattelkow, Jürgen; Rumpf, Bernhard; Eibinger, Manuel; Reishofer, David; Winkler, Robert; Nidetzky, Bernd; Spirk, Stefan; Plank, Harald

    2016-01-01

    In many areas of science and technology, patterned films and surfaces play a key role in engineering and development of advanced materials. Here, we introduce a new generic technique for the fabrication of polysaccharide nano-structures via focused electron beam induced conversion (FEBIC). For the proof of principle, organosoluble trimethylsilyl-cellulose (TMSC) thin films have been deposited by spin coating on SiO2 / Si and exposed to a nano-sized electron beam. It turns out that in the exposed areas an electron induced desilylation reaction takes place converting soluble TMSC to rather insoluble cellulose. After removal of the unexposed TMSC areas, structured cellulose patterns remain on the surface with FWHM line widths down to 70 nm. Systematic FEBIC parameter sweeps reveal a generally electron dose dependent behavior with three working regimes: incomplete conversion, ideal doses and over exposure. Direct (FT-IR) and indirect chemical analyses (enzymatic degradation) confirmed the cellulosic character of ideally converted areas. These investigations are complemented by a theoretical model which suggests a two-step reaction process by means of TMSC → cellulose and cellulose → non-cellulose material conversion in excellent agreement with experimental data. The extracted, individual reaction rates allowed the derivation of design rules for FEBIC parameters towards highest conversion efficiencies and highest lateral resolution. PMID:27585861

  4. Beam-induced radiation in the compact muon solenoid tracker at the Large Hadron Collider

    Indian Academy of Sciences (India)

    A P Singh; P C Bhat; N V Mokhov; S Beri

    2010-05-01

    The intense radiation environment at the Large Hadron Collider, CERN at a design energy of $\\sqrt{s} = 14$ TeV and a luminosity of 1034 cm−2S−1 poses unprecedented challenges for safe operation and performance quality of the silicon tracker detectors in the CMS and ATLAS experiments. The silicon trackers are crucial for the physics at the LHC experiments, and the inner layers, being situated only a few centimeters from the interaction point, are most vulnerable to beam-induced radiation. We have recently carried out extensive Monte Carlo simulation studies using MARS program to estimate particle fluxes and radiation dose in the CMS silicon pixel and strip trackers from proton–proton collisions at $\\sqrt{s} = 14$ TeV and from machine-induced background such as beam–gas interactions and beam halo. We will present results on radiation dose, particle fluxes and spectra from these studies and discuss implications for radiation damage and performance of the CMS silicon tracker detectors.

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

    Energy Technology Data Exchange (ETDEWEB)

    Covo, M K; Molvik, A; Friedman, A; Westenskow, G; Barnard, J J; Cohen, R; Seidl, P; Kwan, J W; Logan, G; Baca, D; Bieniosek, F; Celata, C M; Vay, J; Vujic, J L

    2006-03-06

    Electron clouds limit the performance of many major accelerators and storage rings. Significant quantities of electrons result when halo ions are lost to beam tubes, generating gas which can be ionized and ion-induced electrons that can multiply and accumulate, causing degradation or loss of the ion beam. In order to understand the physical mechanisms of ion-induced electron production, experiments studied the impact of 50 to 400 keV K{sup +} ions on stainless steel surfaces near grazing incidence, using the 500 kV Ion Source Test Stand (STS-500) at LLNL. The experimental electron yield scales with the electronic component (dE{sub e}/dx) of the stopping power and its angular dependence does not follow l/cos({theta}). A theoretical model is developed, using TRIM code to evaluate dE{sub e}/dx at several depths in the target, to estimate the electron yield, which is compared with the experimental results. The experiment extends the range of energy from previous works and the model reproduces the angular dependence and magnitude of the electron yield.

  6. Fast crystallization of amorphous Gd{sub 2}Zr{sub 2}O{sub 7} induced by thermally activated electron-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhangyi; Qi, Jianqi, E-mail: qijianqi@scu.edu.cn; Zhou, Li; Feng, Zhao; Yu, Xiaohe [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Gong, Yichao [College of Materials Science and Engineering, Sichuan University, Chengdu 610064 (China); Yang, Mao; Wei, Nian [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics of Ministry of Education, Sichuan University, Chengdu 610064 (China); Shi, Qiwu [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); College of Materials Science and Engineering, Sichuan University, Chengdu 610064 (China); Lu, Tiecheng, E-mail: lutiecheng@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics of Ministry of Education, Sichuan University, Chengdu 610064 (China)

    2015-12-07

    We investigate the ionization and displacement effects of an electron-beam (e-beam) on amorphous Gd{sub 2}Zr{sub 2}O{sub 7} 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 Gd{sub 2}Zr{sub 2}O{sub 7} 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/cm{sup 2}). The crystallization occurred on the nanoscale upon ionization irradiation at 400 °C after a dose of less than 10{sup 17} electrons/cm{sup 2}. 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.

  7. Effect of electron beam irradiation on fully aromatic polyimide

    International Nuclear Information System (INIS)

    It was clarified that the carbon fiber-reinforced plastics using polyether-ether-ketone as the matrix resin showed high radiation resistance, and the high temperature characteristics were improved by irradiation. The glass transition temperature of PEEK is about 150degC, and for the use in space and aviation fields, the matrix resin with higher heat resistance and thermoplastic property has been demanded. The thermoplastic polyimide, the development of which is advanced by Mitsui Toatsu at present, shows high glass transition temperature, and seems suitable to the use like this. In this study, the effect that electron beam irradiation exerted on the high temperature characteristics of the new thermoplastic polyimide and the change of the molecular mobility by irradiation were measured, and the applicability as a heat resistant and radiation resistant matrix was evaluated. The tensile test and the measurement of dynamic viscoelasticity were carried out. This polyimide maintained the value of 50% - 70% of the value measured at 23 degC even in the temperature zone of 150 - 200 degC, and has the excellent high temperature characteristics. Its strength and Young's modulus hardly changed by electron beam irradiation up to 120 MGy. (K.I.)

  8. The local transformation of the chemical structures induced in polymer by heavy ion-beam irradiation: the characterization of ion in the interaction with material-

    International Nuclear Information System (INIS)

    The local transformations of the chemical structure induced in low density polyethylene (LDPE) by ion-beams with different characteristics are investigated by using micro-FT-IR system. On irradiation by heavier ions than H+, the remarkable LET effect is found in the transformation of the trans-vinylene and the end-vinyl groups. This can not be found on irradiation by H+. Moreover, an importance of the charge number in calculation of the stopping power is pointed out. (author)

  9. DYNAMICS OF IONIZATION-ENHANCED SPECTRAL EXPANSION IN WATER INDUCED BY AN INTENSE FEMTOSECOND LASER BEAM

    Institute of Scientific and Technical Information of China (English)

    WANG SHU-FENG; QIN YUAN-DONG; YANG HONG; WANG DAN-LING; ZHU CHANG-JUN; GONG QI-HUANG

    2001-01-01

    The dynamic process of white-continuum generation in water was investigated by the pump-probe technique with a femtosecond intense laser at 805nm. The spectrum width of the probe beam was broadened at the blue side and varied with different delay times. This blueshift was attributed to the ionization-enhanced optical nonlinearity, in which both the multi-photon ionization and avalanche ionization had an effect.

  10. Third-order moment effect of beam position measurements

    International Nuclear Information System (INIS)

    Third-order moments of beam charge distribution cause unwanted errors in beam positions measured by a beam position monitor with two or four electrodes. These errors can be reduced or corrected by adding or subtracting third-order moment terms in difference equations of signal voltages output from electrodes. In the case of a six-electrode beam position monitor with circular cross-section which is used in SPring-8 linear accelerator errors calculated with and without correction are 24 μm and 360 μm at a simulated beam position of x = 3 mm, y = 3 mm apart form a duct center. (author)

  11. 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.*

  12. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. Y.

    2014-04-07

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  13. Effect of beam oscillation on borated stainless steel electron beam welds

    International Nuclear Information System (INIS)

    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.

  14. Calculating Variations in Biological Effectiveness for a 62 MeV Proton Beam.

    Science.gov (United States)

    Carante, Mario Pietro; Ballarini, Francesca

    2016-01-01

    A biophysical model of radiation-induced cell death and chromosome aberrations [called BIophysical ANalysis of Cell death and chromosome Aberrations (BIANCA)] 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 spread-out Bragg peak (SOBP) 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 relative biological effectiveness (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

  15. Calculating Variations in Biological Effectiveness for a 62 MeV Proton Beam

    Science.gov (United States)

    Carante, Mario Pietro; Ballarini, Francesca

    2016-01-01

    A biophysical model of radiation-induced cell death and chromosome aberrations [called BIophysical ANalysis of Cell death and chromosome Aberrations (BIANCA)] 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 spread-out Bragg peak (SOBP) 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 relative biological effectiveness (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

  16. Modeling of space charge effects in intense electron beams using two and three dimensional Green's function

    International Nuclear Information System (INIS)

    Green's functions for Maxwell equations can provide a powerful technique for the modeling of high-intensity particle accelerators. The authors present both, two-and three-dimensional models of space charge in intense charged particle beams. Specifically, they compute the Green's function for a point charge located inside of a perfectly conducting drift tube with periodic boundary conditions. As an application of the two-dimensional Greens's function, they study the effect of current oscillations and associated envelope oscillations on inducing beam halos in intense relativistic electron beams in periodic permanent magnet focusing and uniform solenoidal focusing klystrons. For system parameters corresponding to the SLAC PPM Klystron experiment, the authors find that a sizeable initial envelope mismatch produces halo particles with a maximum radius extending to several core radii at the output section. An eigenfunction expansion technique is utilized for the computation of the three-dimensional Green's function. The authors show the agreement of the function with electrostatic potential that can be computed exactly, i.e. potential due to an on axis distribution with infinite conductor radius. Results from multi-particle simulations obtained from this function are presented

  17. High aspect ratio AFM Probe processing by helium-ion-beam induced deposition.

    Science.gov (United States)

    Onishi, Keiko; Guo, Hongxuan; Nagano, Syoko; Fujita, Daisuke

    2014-11-01

    A Scanning Helium Ion Microscope (SHIM) is a high resolution surface observation instrument similar to a Scanning Electron Microscope (SEM) since both instruments employ finely focused particle beams of ions or electrons [1]. The apparent difference is that SHIMs can be used not only for a sub-nanometer scale resolution microscopic research, but also for the applications of very fine fabrication and direct lithography of surfaces at the nanoscale dimensions. On the other hand, atomic force microscope (AFM) is another type of high resolution microscopy which can measure a three-dimensional surface morphology by tracing a fine probe with a sharp tip apex on a specimen's surface.In order to measure highly uneven and concavo-convex surfaces by AFM, the probe of a high aspect ratio with a sharp tip is much more necessary than the probe of a general quadrangular pyramid shape. In this paper we report the manufacture of the probe tip of the high aspect ratio by ion-beam induced gas deposition using a nanoscale helium ion beam of SHIM.Gas of platinum organic compound was injected into the sample surface neighborhood in the vacuum chamber of SHIM. The decomposition of the gas and the precipitation of the involved metal brought up a platinum nano-object in a pillar shape on the normal commercial AFM probe tip. A SHIM system (Carl Zeiss, Orion Plus) equipped with the gas injection system (OmniProbe, OmniGIS) was used for the research. While the vacuum being kept to work, we injected platinum organic compound ((CH3)3(CH3C5H4)Pt) into the sample neighborhood and irradiated the helium ion beam with the shape of a point on the apex of the AFM probe tip. It is found that we can control the length of the Pt nano-pillar by irradiation time of the helium ion beam. The AFM probe which brought up a Pt nano-pillar is shown in Figure 1. It is revealed that a high-aspect-ratio Pt nano-pillar of ∼40nm diameter and up to ∼2000 nm length can be grown. In addition, for possible heating

  18. Effects of nonlinear left-hand circularly polarized waves supported by a proton beam on linear beam-plasma instabilities

    International Nuclear Information System (INIS)

    This paper studies the effect of nonlinear left-hand polarized waves supported by a proton beam on the linear circularly polarized instabilities driven by the same beam. It shows that the nonlinear wave can either stabilize or destabilize the linear instabilities. The effects depend on the amplitude of the nonlinear wave and on the temperature of the system. It also shows that purely electrostatic ion-acoustic-like waves, can be destabilized by the large amplitude wave. The latter instabilities do not occur in the absence of the nonlinear waves

  19. Laser-beam-induced current mapping evaluation of porous silicon-based passivation in polycrystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rabha, M. Ben; Bessais, B. [Laboratoire de Nanomateriaux et des Systemes pour l' Energie, Centre de Recherches et des Technologies de l' Energie - Technopole de Borj-Cedria BP 95, 2050 Hammam-Lif (Tunisia); Dimassi, W.; Bouaicha, M.; Ezzaouia, H. [Laboratoire de photovoltaique, des semiconducteurs et des nanostructures, Centre de Recherches et des Technologies de l' Energie - Technopole de Borj-Cedria BP 95, 2050 Hammam-Lif (Tunisia)

    2009-05-15

    In the present work, we report on the effect of introducing a superficial porous silicon (PS) layer on the performance of polycrystalline silicon (pc-Si) solar cells. Laser-beam-induced current (LBIC) mapping shows that the PS treatment on the emitter of pc-Si solar cells improves their quantum response and reduce the grain boundaries (GBs) activity. After the porous silicon treatment, mapping investigation shows an enhancement of the LBIC and the internal quantum efficiency (IQE), due to an improvement of the minority carrier diffusion length and the passivation of recombination centers at the GBs as compared to the reference substrate. It was quantitatively shown that porous silicon treatment can passivate both the grains and GBs. (author)

  20. Lensing effect of electromagnetically induced transparency involving a Rydberg state

    Science.gov (United States)

    Han, Jingshan; Vogt, Thibault; Manjappa, Manukumara; Guo, Ruixiang; Kiffner, Martin; Li, Wenhui

    2015-12-01

    We study the lensing effect experienced by a weak probe field under conditions of electromagnetically induced transparency (EIT) involving a Rydberg state. A Gaussian coupling beam tightly focused on a laser-cooled atomic cloud produces an inhomogeneity in the coupling Rabi frequency along the transverse direction and makes the EIT area acting like a gradient-index medium. We image the probe beam at the position where it exits the atomic cloud and observe that a red-detuned probe light is strongly focused with a greatly enhanced intensity whereas a blue-detuned one is defocused with a reduced intensity. Our experimental results agree very well with the numerical solutions of Maxwell-Bloch equations.

  1. Lensing effect of electromagnetically induced transparency involving a Rydberg state

    CERN Document Server

    Han, Jingshan; Manjappa, Manukumara; Guo, Ruixiang; Kiffner, Martin; Li, Wenhui

    2015-01-01

    We study the lensing effect experienced by a weak probe field under conditions of electromagnetically induced transparency (EIT) involving a Rydberg state. A Gaussian coupling beam tightly focused on a laser-cooled atomic cloud produces an inhomogeneity in the coupling Rabi frequency along the transverse direction and makes the EIT area acting like a gradient-index medium. We image the probe beam at the position where it exits the atomic cloud, and observe that a red-detuned probe light is strongly focused with a greatly enhanced intensity whereas a blue-detuned one is de-focused with a reduced intensity. Our experimental results agree very well with the numerical solutions of Maxwell-Bloch equations.

  2. Remote steering of laser beams by radar- and laser-induced refractive-index gradients in the atmosphere

    International Nuclear Information System (INIS)

    Refractive-index gradients induced in the atmospheric air by properly tailored laser and microwave fields are shown to enable a remote steering of laser beams. Heating-assisted modulation of the refractive index of the air by microwave radiation is shown to support small-angle laser-beam bending with bending angles on the order of 10-2. Ionization of the atmospheric air by dyads of femto- and nanosecond laser pulses, on the other hand, can provide beam deflection angles in excess of π/5, offering an attractive strategy for radiation transfer, free-space communications, and laser-based standoff detection

  3. 3D Simulations of Space Charge Effects in Particle Beams

    International Nuclear Information System (INIS)

    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 (∼ 109 protons/cm3) 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)

  4. Electron beam irradiation effect on GaN HEMT

    International Nuclear Information System (INIS)

    In this work, GaN HEMTs (High Electron Mobility Transistor) were irradiated by 0.8 and 1.2 MeV electron beams, and the irradiation effects were investigated. The results show that the device damage caused by 0.8 MeV electrons is more serious than that by 1.2 MeV electrons. Saturation drain current increase and threshold voltage negative shift are due to trapped positive charge from ionization in the AlGaN layer and N, Ga vacancy from non-ionizing energy loss in the GaN layer. Electron traps and trapped positive charges from non-ionizing in the AlGaN layer act as trap-assisted-tunneling centers that increase the gate leakage current.(authors)

  5. 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)

  6. Proton Induced Effects on Tungsten Powder

    CERN Multimedia

    2012-01-01

    In the HRMT-10 experiment, that took place in HiRadMat facility of CERN/SPS, the effects of a high-power incident proton beam on a tungsten powder target were investigated. In this video, 1.3E11 protons @ 440 GeV are impinging on the target.

  7. Proton Induced Effects on Tungsten Powder

    CERN Multimedia

    2012-01-01

    In the HRMT-10 experiment, that took place in HiRadMat facility of CERN/SPS, the effects of a high-power incident proton beam on a tungsten powder target were investigated. In this video, 1.85E11 protons @ 440 GeV are impinging on the target.

  8. Proton Induced Effects on Tungsten Powder

    CERN Multimedia

    2012-01-01

    In the HRMT-10 experiment, that took place in HiRadMat facility of CERN/SPS, the effects of a high-power incident proton beam on a tungsten powder target were investigated. In this video, 2E11 protons @ 440 GeV are impinging on the target.

  9. Proton Induced Effects on Tungsten Powder

    CERN Multimedia

    HiRadMat facility of CERN/SPS

    2012-01-01

    In the HRMT-10 experiment, that took place in HiRadMat facility of CERN/SPS, the effects of a high-power incident proton beam on a tungsten powder target were investigated. In this video, 1.7E11 protons @ 440 GeV are impinging on the target.

  10. Proton Induced Effects on Tungsten Powder

    CERN Multimedia

    2012-01-01

    In the HRMT-10 experiment, that took place in HiRadMat facility of CERN/SPS, the effects of a high-power incident proton beam on a tungsten powder target were investigated. In this video, 2.64E11 protons @ 440 GeV are impinging on the target.

  11. Particle Beam may have Higher Effectiveness in Treating Chemoresistant Cancers than Low-LET Photon Beam Therapy

    Directory of Open Access Journals (Sweden)

    Rupak Pathak

    2015-06-01

    Full Text Available It is now well-established that outcomes of radiotherapy depend on quality of radiation. A large body of experimental evidences suggests that high-LET (linear energy transfer radiation or particle radiation has the ability to kill tumor cells more efficiently than low-LET photon beams such as X-rays and γ-rays [1,2]. The unique characteristics of particle beam, which includes precise dose distribution, formation of complex and “clustered” DNA damage in target cells, capacity to kill cells with equal effectiveness irrespective of their cell cycle stage and oxygen content, ability to cause biological damage by direct action, and inverse dosedepth relation are considered to be responsible for higher relative biological effectiveness (RBE than low-LET photon beams. However, the efficacy of particle radiation in killing chemo-resistant cells compared to low-LET radiation is not well-documented

  12. The effect of the laser wavelength on collinear double pulse laser induced breakdown spectroscopy (DP-LIBS)

    Science.gov (United States)

    Wang, Qi; Lin, Yanqing; Liu, Jing; Fan, Shuang; Xu, Zhuopin; Huang, Qing; Wu, Yuejin

    2016-05-01

    The pulsed lasers at wavelengths of 532 nm and 1064 nm were used as two beams of light for collinear double pulse laser induced breakdown spectroscopy (DP-LIBS). By changing the time sequence of two beams of different lasers, we studied the effect of the interval of two pulses of DP-LIBS on spectral signals compared with single pulsed (SP) LIBS.

  13. Study of plasma natural convection induced by electron beam in atmosphere [

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yongfeng, E-mail: yfdeng@mail.dlut.edu.cn; Han, Xianwei [Shaanxi Power Machine Design and Research Institute, Xi' an 710100 (China); Tan, Yonghua [Academy of Aerospace Propulsion Technology, Xi' an 710100 (China)

    2014-06-15

    Using high-energy electron beams to ionize air is an effective way to produce a large-size plasma in the atmosphere. In particular, with a steady-state high power generator, some unique phenomena can be achieved, including natural convection of the plasma. The characteristics of this convection are studied both experimentally and numerically. The results show that an asymmetrical temperature field develops with magnitudes that vary from 295 K to 389 K at a pressure of 100 Torr. Natural convection is greatly enhanced under 760 Torr. Nevertheless, plasma transport is negligible in this convection flow field and only the plasma core tends to move upward. Parameter analysis is performed to discern influencing factors on this phenomenon. The beam current, reflecting the Rayleigh number Ra effect, correlates with convection intensity, which indicates that energy deposition is the underlying key factor in determining such convections. Finally, natural convection is concluded to be an intrinsic property of the electron beam when focused into dense air, and can be achieved by carefully adjusting equipment operations parameters.

  14. On using the beaming effect to measure spin-orbit alignment in stellar binaries with Sun-like components

    CERN Document Server

    Shporer, Avi; Mazeh, Tsevi; Zucker, Shay

    2011-01-01

    The beaming effect (aka Doppler boosting) induces a variation in the observed flux of a luminous object, following its observed radial velocity variation. We describe a photometric signal induced by the beaming effect during eclipse of binary systems, where the stellar components are late type Sun-like stars. The shape of this signal is sensitive to the angle between the eclipsed star's spin axis and the orbital angular momentum axis, thereby allowing its measurement. We show that during eclipse there are in fact two effects, superimposed on the known eclipse light curve. One effect is produced by the rotation of the eclipsed star, and is the photometric analog of the spectroscopic Rossiter-McLaughlin effect, thereby it contains information about the sky-projected spin-orbit angle. The other effect is produced by the varying weighted difference, during eclipse, between the beaming signals of the two stars. We give approximated analytic expressions for the amplitudes of the two effects, and present a numerical...

  15. Some radiation-induced effects in typical calorimetric materials and sensors

    International Nuclear Information System (INIS)

    The radiation-induced effects of the electron beams (EB) generated by accelerators in typical calorimetric materials and sensors have been surveyed and investigated. These effects influence the useful lifetime of the materials and sensors at high doses of about 4,000 to 5,000 kGy. (author)

  16. Dose Rate Effects on The Radiation Oxidation of Polyethylene: Electron Beam vs Gamma Irradiation

    International Nuclear Information System (INIS)

    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

  17. Intense laser beam guiding in self-induced electron cavitation channel in underdense plasmas

    Institute of Scientific and Technical Information of China (English)

    Cang Yu; Yu Wei; Wu Hui-Chun; Xu Han; Tian You-Wei

    2007-01-01

    In underdense plasmas, the transverse ponderomotive force of an intense laser beam with Gaussian transverse profile expels electrons radially, and it can lead to an electron cavitation. An improved cavitation model with charge conservation constraint is applied to the determination of the width of the electron cavity. The envelope equation for laser spot size derived by using source-dependent expansion method is extended to including the electron cavity. The condition for self-guiding is given and illuminated by an effective potential for the laser spot size. The effects of the laser power, plasma density and energy dissipation on the self-guiding condition are discussed.

  18. Focused-ion-beam induced interfacial intermixing of magnetic bilayers for nanoscale control of magnetic properties

    International Nuclear Information System (INIS)

    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)

  19. Diagnostic of a laser induced plasma by means of a CO2 laser beam-deflection technique

    International Nuclear Information System (INIS)

    In order to diagnose a laser-induced plasma of very small size with the aid of a beam-deflection technique, a cw probing CO2 laser beam which undergoes refraction and absorption by the electrons of this plasma has been employed. The resulting deflection is determined by means of a partially absorbing CaF2 wedge in conjunction with a fast HgCdTe infrared detector. By this diagnostic technique the spatial and temporal distribution of the electron density in a laser-induced plasma absorption and the actual laser power gives the possibility to estimate the electron temperature, the pressure and the velocity of the expanding plasma. (orig.)

  20. 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