WorldWideScience

Sample records for beam bending magnets

  1. Superconducting beam bending magnets at CERN

    CERN Multimedia

    1977-01-01

    The photo shows Gerhard Kesseler with the cyogenic vessels for one of the 10.8 Tesla-metre beam bending magnets. The magnet itself (not visible) is sitting inside the superinsukated helium vessel (white). The next larger shell and the biggest tubular structure (with the largest part behind the person) is the insulation vacuum tank. See CERN Courier 1970 pp. 228-229 CERN Courier 1973 pp. 144-145 Yellow Report CERN 78-03, 1978

  2. Semiconductor laser beam bending

    OpenAIRE

    YILDIRIM, REMZİ; ÇELEBİ, FATİH VEHBİ

    2015-01-01

    This study is about a single-component cylindrical structured lens with a gradient curve that was used for bending laser beams. It operates under atmospheric conditions and bends the laser beam independently of temperature, pressure, polarity, polarization, magnetic field, electric field, radioactivity, and gravity. A single-piece cylindrical lens that can bend laser beams was developed. Lenses are made of transparent, tinted, or colored glass and are used to undermine or absorb the energy of...

  3. Beam deflection into a quadrant by a positionally stationary magnetic bending system

    International Nuclear Information System (INIS)

    A system of postionally stationary magnets is analyzed for the continuously variable deflection of a 50 MeV electron beam. The system is composed of a collection of horizontal and vertical bending magnets, quadrupoles, and a final deflection magnet that is conical in shape and capable of deflections of plus or minus 50 degrees simultaneously in both horizonal and vertical planes. Throughout the system the beam is assumed to be focused by its own magnetic self-field, the electric self-field being neutralized by background ions. The motion of the beam in the externally applied magnetic fields may then be considered as single particle motion. The system of bending magnets and quadrupoles pre-conditions the beam by introducing the proper displacements and angles at the entrance to the final deflection magnet for momentum deviations up to plus or minus one percent. The displacements and angles are determined by the chromaticity of the final deflection and are a function of the bending angles in the two planes. The total system is then doubly achromatic in both planes. The preconditioning magnets are of standard accelerator beam transport design while the conical deflection magnet is of a design fashioned from a television deflection coil scaled up by about a factor of 10 in size

  4. Design of two magnet beam bending system for medical linear electron accelerator

    International Nuclear Information System (INIS)

    The electron accelerators of energies 6 to 20 MeV are extensively used for treating cancer and various skin diseases because of its physical dose distribution. Generally, high energy medical electron linacs are usually mounted horizontally. The emergent electron beam from the accelerating tube is deflected magnetically through 270 deg into vertical plane to hit the X-ray target or electron scatterer. The 270 deg doubly achromatic beam bending magnet system can be made using one, two and three magnets. However, two magnet system configurations reduce the magnet height as compared to others. Therefore, two magnet system has been designed using computer program Lorentz-3EM software for 6 to 20 MeV electrons. On the basis of the requirement of beam parameters such as energy, spot and area of exposure etc, the magnet system has been optimized. This system consists of two sector magnets of which sector-1 deflects electron beam by an angle ∼195 deg and sector-2 by ∼ 75 deg. It is observed that at the 2500, 4000 and 6000 A-turn, the optimized design produces 3400, 6600 and 9500 guass of magnetic field at median plane which require to bend the electron beam of energy 6, 12, and 18 MeV respectively in 270 deg. It is also observed that the convergence angle produced by the first sector has been compensated by the divergence angle produced by the second sector magnet. The optimized two magnet system gives uniform distribution of magnetic field and extracts 6 to 18 MeV electron beam having minimum energy spread, angular divergence and radial displacement. (author)

  5. Pseudo Slice Energy Spread in Dynamics of Electron Beams Moving through Magnetic Bends

    CERN Document Server

    Li, Rui

    2014-01-01

    In the previous canonical formulation of beam dynamics for an electron bunch moving ultrarelativistically through magnetic bending systems, we have shown that the transverse dynamics equation for a particle in the bunch has a driving term which behaves as the centrifugal force caused by the particle's initial potential energy due to collective particle interactions within the bunch. As a result, the initial potential energy at the entrance of a bending system, which we call pseudo (kinetic) energy, is indistinguishable from the usual kinetic energy offset from the design energy in its perturbation to particle optics through dispersion and momentum compaction. In this paper, in identifying this centrifugal force on particles as the remnant of the CSR cancellation effect in transverse particle dynamics, we show how the dynamics equation in terms of the canonical momentum for beam motion on a curved orbit is related to the Panofsky-Wenzel theorem for wakefields for beam motion on a straight path. It is shown tha...

  6. Longitudinal beam profiles affected by the current ripples of bending magnets in HIMAC synchrotron

    International Nuclear Information System (INIS)

    The relation between the longitudinal-emittance growth and the noise profiles of the power supply for the bending-magnets was studied to avoid the particle losses from the bucket during the several-minutes circulation. In order to investigate the effect of the actual noise ripples of the power supply, as well as monochromatic noise near to the synchrotron-oscillation frequency, on the temporal evolution of the longitudinal emittance, the beam distribution on the longitudinal phase space was simulated using the tracking method. We found that the longitudinal emittance was increasing with time owing to the series of the noise spectrum, not to the monochromatic noise. (author)

  7. Design of electron beam bending magnet system using three sector magnets for electron and photon therapy: a simulation approach

    International Nuclear Information System (INIS)

    The 270 degree doubly achromatic beam bending magnet system using three sector magnets has been designed mainly for treating cancer and skin diseases. The main requirements of the design of three magnet system is to focus an electron beam having a spot size less than 3mm x 3mm, energy spread within 3% and divergence angle ≤ 3 mrad at the target. To achieve these parameters the simulation was carried out using Lorentz-3EM software. The beam spot, divergence angle and energy spread were observed with respect to the variation in angles of sector magnets and drift distances. From the simulated results, it has been optimized that all the three sector magnets has an angle of 62 degree and the drift distance 68 mm. It is also observed that at the 1637, 2425, 3278, 4165 and 5690 Amp-turn, the optimized design produces 3851, 5754, 7434, 9356 and 11425 Gauss of magnetic field at median plane require to bend 6, 9, 12, 15 and 18 MeV energy of electron respectively for electron therapy. The output parameters of the optimized design are energy spread 3%, divergence angle ∼ 3 mrad and spot size 2.8 mm. Moreover, for 6 MV and 15 MV photon therapy application, an electron beam of energy 6.5 MeV and 15.5 MeV extracted from magnet system and focussed on the Bremsstrahlung target. For the photon therapy the 1780, and 4456 amp-turn, an optimized design produces 4148 and 9682 Gauss of magnetic field at median plane require to bend 6.5 and 15.5 MeV energy of electron respectively, which further produces Bremsstrahlung in Tungsten target. (author)

  8. Goos-Hänchen effect and bending of spin wave beams in thin magnetic films

    Energy Technology Data Exchange (ETDEWEB)

    Gruszecki, P., E-mail: pawel.gruszecki@amu.edu.pl; Krawczyk, M., E-mail: krawczyk@amu.edu.pl [Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, Poznań 61-614 (Poland); Romero-Vivas, J. [Department of Electronic and Computer Engineering, University of Limerick, Limerick (Ireland); Dadoenkova, Yu. S.; Dadoenkova, N. N. [Donetsk Physical and Technical Institute of the National Academy of Sciences of Ukraine, 83114 Donetsk (Ukraine); Ulyanovsk State University, 42 Leo Tolstoy str., 432000 Ulyanovsk (Russian Federation); Lyubchanskii, I. L. [Donetsk Physical and Technical Institute of the National Academy of Sciences of Ukraine, 83114 Donetsk (Ukraine)

    2014-12-15

    For magnon spintronic applications, the detailed knowledge of spin wave (SW) beam dispersion, transmission (reflection) of SWs passing through (reflected from) interfaces, or borders or the scattering of SWs by inhomogeneities is crucial. These wave properties are decisive factors on the usefulness of a particular device. Here, we demonstrate, using micromagnetic simulations supported by an analytical model, that the Goos-Hänchen (GH) shift exists for SW reflecting from thin film edge and that with the effect becomes observable. We show that this effect will exist for a broad range of frequencies in the dipole-exchange range, with the magnetization degree of pinning at the film edge as the crucial parameter, whatever its nature. Moreover, we have also found that the GH effect can be accompanied or even dominating by a bending of the SW beam due to the inhomogeneity of the internal magnetic field. This inhomogeneity, created by demagnetizing field taking place at the film edge, causes gradual change of SWs refractive index. The refraction of the SW beams by the non-uniformity of the magnetic field enables the exploration of graded index magnonics and metamaterial properties for the transmission and processing of information at nanoscale.

  9. Goos-Hänchen effect and bending of spin wave beams in thin magnetic films

    International Nuclear Information System (INIS)

    For magnon spintronic applications, the detailed knowledge of spin wave (SW) beam dispersion, transmission (reflection) of SWs passing through (reflected from) interfaces, or borders or the scattering of SWs by inhomogeneities is crucial. These wave properties are decisive factors on the usefulness of a particular device. Here, we demonstrate, using micromagnetic simulations supported by an analytical model, that the Goos-Hänchen (GH) shift exists for SW reflecting from thin film edge and that with the effect becomes observable. We show that this effect will exist for a broad range of frequencies in the dipole-exchange range, with the magnetization degree of pinning at the film edge as the crucial parameter, whatever its nature. Moreover, we have also found that the GH effect can be accompanied or even dominating by a bending of the SW beam due to the inhomogeneity of the internal magnetic field. This inhomogeneity, created by demagnetizing field taking place at the film edge, causes gradual change of SWs refractive index. The refraction of the SW beams by the non-uniformity of the magnetic field enables the exploration of graded index magnonics and metamaterial properties for the transmission and processing of information at nanoscale

  10. A new bend magnet beam line for scanning transmission x-ray microscopy at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, Tony; Ade, Harald; Kilcoyne, A.L. David; Kritscher, Michael; Tylisczcak, Tolek; Fakra, Sirine; Hitchcock, Adam P.; Hitchcock, Peter; Padmore, Howard A.

    2001-12-12

    The high brightness of the bend magnets at the Advanced Light Source has been exploited to illuminate a Scanning Transmission X-ray Microscope (STXM). This is the first diffraction-limited scanning x-ray microscope to operate with useful count rate on a synchrotron bend magnet source. A simple, dedicated beam line has been built covering the range of photon energy from 250 eV to 600 eV. Ease of use and operational availability are radically improved compared to previous installations using undulator beams. This facility provides radiation for C 1s, N 1s and O 1s near edge x-ray absorption spectro-microscopy with a spectral resolution up to about 1:5000 and with STXM count rates in excess of 1 MHz.

  11. AA, bending magnet, BLG

    CERN Multimedia

    1980-01-01

    The very particular lattice of the AA required 2 types of dipole (bending magnets; BLG, long and narrow; BST, short and wide). The BLG had a steel length of 4.70 m, a good field width of 0.24 m, and a weight of about 70 t. Jean-Claude Brunet inspects the lower half of a BLG. For the BST magnets see 7811105 and 8006036.

  12. Experimental Test of Data Analysis Methods from Staggered Pair X-ray Beam Position Monitors at Bending Magnet Beamlines

    International Nuclear Information System (INIS)

    Different methods have been proposed to calculate the vertical position of the photon beam centroid from the four blade currents of staggered pair X-ray beam position monitors (XBPMs) at bending magnet beamlines since they emerged about 15 years ago. The original difference-over-sum method introduced by Peatman and Holldack is still widely used, even though it has been proven to be rather inaccurate at large beam displacements. By systematically generating bumps in the electron orbit of the ANKA storage ring and comparing synchronized data from electron BPMs and XBPM blade currents, we have been able to show that the log-ratio method by S. F. Lin, B.G. Sun et al. is superior (meaning the characteristic being closer to linear) to the ratio method, which in turn is superior to the difference over sum method. These findings are supported by simulations of the XBPM response to changes of the beam centroid. The heuristic basis for each of the methods is investigated. The implications on using XBPM readings for orbit correction are discussed

  13. Confirmation and Readjustment of Bending Magnet Beam-Line Optics Using SHADOW

    Science.gov (United States)

    Matsubara, Takahiro; Kanda, Kazuhiro; Kato, Yuri; Hisao, Shintarou; Shoji, Yoshihiko

    2007-01-01

    Optical alignment of the NewSUBARU beam-line 6 (BL6) is discussed by comparing the observed SR profiles with the calculated results of ray-tracing using SHADOW. A new screen monitor was mounted downstream of the first mirror to observe the synchrotron radiation profile. The distorted profile downstream of the second mirror was attributed to the rotation of the first mirror along the vertical axis. The distortion was successfully improved by a re-adjustment according to the calculations.

  14. Confirmation and Readjustment of Bending Magnet Beam-Line Optics Using SHADOW

    International Nuclear Information System (INIS)

    Optical alignment of the NewSUBARU beam-line 6 (BL6) is discussed by comparing the observed SR profiles with the calculated results of ray-tracing using SHADOW. A new screen monitor was mounted downstream of the first mirror to observe the synchrotron radiation profile. The distorted profile downstream of the second mirror was attributed to the rotation of the first mirror along the vertical axis. The distortion was successfully improved by a re-adjustment according to the calculations

  15. Large deformation dynamic bending of composite beams

    OpenAIRE

    Derian, Edward J.

    1985-01-01

    The large deformation response of composite beams subjected to a dynamic axial load was studied. The beams were loaded with a moderate amount of eccentricity to promote bending. The study was primarily experimental but some finite element results were obtained. Both the deformation and the failure of the beams were of interest. The static response of the beams was also studied in order to determine the difference between the static and dynamic failure. Twelve different la...

  16. Self-bending symmetric cusp beams

    Science.gov (United States)

    Gong, Lei; Liu, Wei-Wei; Ren, Yu-Xuan; Lu, Yao; Li, Yin-Mei

    2015-12-01

    A type of self-bending symmetric cusp beams with four accelerating intensity maxima is theoretically and experimentally presented. Distinguished from the reported regular polygon beams, the symmetric cusp beams simultaneously exhibit peculiar features of natural autofocusing and self-acceleration during propagation. Further, such beams take the shape of a fine longitudinal needle-like structure at the focal region and possess the strong ability of self-healing over obstacles. All these intriguing properties were verified experimentally. Particularly, the spatial profile of the reconstructed beam exhibits spatially sculpted optical structure with four siamesed curved arms. Thus, we anticipate that the structured beam will benefit optical guiding and optofluidics in surprising ways.

  17. Self-bending symmetric cusp beams

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Lei; Liu, Wei-Wei; Lu, Yao; Li, Yin-Mei, E-mail: liyinmei@ustc.edu.cn [Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026 (China); Ren, Yu-Xuan [Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132 (United States)

    2015-12-07

    A type of self-bending symmetric cusp beams with four accelerating intensity maxima is theoretically and experimentally presented. Distinguished from the reported regular polygon beams, the symmetric cusp beams simultaneously exhibit peculiar features of natural autofocusing and self-acceleration during propagation. Further, such beams take the shape of a fine longitudinal needle-like structure at the focal region and possess the strong ability of self-healing over obstacles. All these intriguing properties were verified experimentally. Particularly, the spatial profile of the reconstructed beam exhibits spatially sculpted optical structure with four siamesed curved arms. Thus, we anticipate that the structured beam will benefit optical guiding and optofluidics in surprising ways.

  18. A finite element analysis of room temperature silicon crystals for the Advanced Photon Source bending-magnet and insertion-device beams

    International Nuclear Information System (INIS)

    The third generation of synchrotron radiation sources, such as the Advanced Photon Source (APS), will provide users with a high brilliance x-ray beam with high power and power densities. In many cases, the first optical component to intercept the x-ray beam is a silicon-crystal monochromator. Due to extreme heat loading, the photon throughput and brilliance will be severely degraded if the monochromator is not properly designed (or cooled). This document describes a series of finite element analyses performed on room temperature silicon for the three standard APS sources, namely, the bending magnet, Wiggler A, and Undulator A. The modeling is performed with the silicon cooled directly with water or liquid gallium through rectangular channels. The temperature distributions and thermally induced deformations are presented

  19. Design Study: ELENA Bending Magnet Prototype

    CERN Document Server

    Schoerling, D

    2013-01-01

    The ELENA bending magnet prototype shall prove that the proposed design meets the requirements set by the ELENA beam dynamics. The following points will be discussed in detail: (i) production process of a magnetic yoke diluted with stainless steel plates, (ii) the stability and repeatability of the field homogeneity of such a yoke over the full working range, (iii) choice of soft magnetic steel, (iv) hysteresis effects, (v) mechanical deformations, (vi) thermal insulation to intercept heat load from baking for activation of NEG coating in the vacuum chamber, (vii) end shim design. In order to verify these points the following measurements will be performed: (i) Hall probe scanning, (ii) integrated field homogeneity measurement (DC), (iii) integrated field homogeneity measurement (AC).

  20. Bending magnets design of cERL

    International Nuclear Information System (INIS)

    We are now constructing Compact Energy Recovery Linac (cERL) to start commissioning in March of 2013. We started constructing 35MeV, 10mA, 1loop design, and after step by step reinforcement, we will complete 245MeV, 100mA, and 2loop facility of cERL. We use 2 type bending magnets, sector type magnet and branch bend. Both magnets are trapezoid shape and bending radiuses are 1m, bending angles are 45degree. After constructing second loop, we use the branch bend to separate low energy electron to first loop and high energy electron to second loop. We report these two type bending magnets design of cERL. (author)

  1. Finger-jointed beams in bending

    DEFF Research Database (Denmark)

    Andreasen, Lotte; Hoffmeyer, Preben

    1997-01-01

    An investigation of the dynamic and static fatique of finger-jointed beams in bending was carried out. Results were obtained for five different frequencies from static loading to a load cycle period of two minutes. A total of seven series were long-term tested and five series were short-term tested...

  2. The superconducting bending magnets 'CESAR'

    CERN Document Server

    Pérot, J

    1978-01-01

    In 1975, CERN decided to build two high precision superconducting dipoles for a beam line in the SPS north experimental area. The aim was to determine whether superconducting magnets of the required accuracy and reliability can be built and what their economies and performances in operation will be. Collaboration between CERN and CAE /SACLAY was established in order to make use of the knowledge and experience already acquired in the two laboratories. (0 refs).

  3. Slice of a LEP bending magnet

    CERN Document Server

    This is a slice of a LEP dipole bending magnet, made as a concrete and iron sandwich. The bending field needed in LEP is small (about 1000 Gauss), equivalent to two of the magnets people stick on fridge doors. Because it is very difficult to keep a low field steady, a high field was used in iron plates embedded in concrete. A CERN breakthrough in magnet design, LEP dipoles can be tuned easily and are cheaper than conventional magnets.

  4. A missing-bending-magnet scheme for PEP

    International Nuclear Information System (INIS)

    This article presents a missing-bending-magnet scheme for PEP as a modification that could be considered if PEP were available as a fully dedicated synchrotron radiation source. The scheme can be applied to one or more PEP sextants without changing the rest. By removing some bending magnets, rearranging the remaining magnets, and adding two quadrupoles, ten additional straight sections per sextant can be created, each 5 m or more in length, for insertion devices. Beam lines therefrom, plus possible beam lines from bending magnets would enter a continuous experimental hall instead of individual tunnels and halls for each beam line. This should result in construction cost savings and increased operations efficiency. The ideal beam orbit is unchanged at the two ends and the middle of the sextant. At the end of the curved part of the sextant the lattice functions match those of the long interaction region straight section in the low emittance configuration of PEP. The electron beam characteristics in the newly created straight sections are described, including the enlargement of the horizontal beam size due to the nonzero dispersion. Some disadvantages of the scheme are increased operations complexity due to the need for nine new quadrupole families, increased beam emittance (by 14.5% is one sextant is modified), and reduced dynamic aperture. However, the dynamic aperture is still about as large as the physical aperture and should be adequate for good beam lifetime and injection. (orig.)

  5. Wooden models of an AA quadrupole between bending magnets

    CERN Multimedia

    1978-01-01

    At two points in the AA lattice, a quadrupole (QDN, defocusing, narrow) was tightly wedged between two bending magnets (BST, short, wide). This picture of wooden models lets one imagine the strong interaction between their magnetic fields. There was no way one could calculate with the necessary accuracy the magnetic effects and their consequences for the machine optics. The necessary corrections were made after measurements with a circulating beam, in a tedious iterative procedure, with corrrection coils and shims.

  6. Bending analysis of laminated composite box beams

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, A.K.; Patel, H.J.; Pang, S.S. (Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Mechanical Engineering)

    1994-01-01

    Box beams are widely used in weight reduction structures such as aircraft wings. The use of composite box beams further reduces the weight factor for such structures with the same deflection and stress as that of isotropic box beams. The difference in the behavior of composite box beam with different fiber orientation, number of plies, and number of stringers also provides a wide range of designing parameters to achieve the required performance for a given problem. A bending analysis has been carried out for the study of deflections and stresses for box beams of different material (isotropic and laminated composites), size, and number of stringers subjected to different kinds of loading conditions. A finite element model has been developed based on the strain energy principle, and the results are compared with an available commercial code COSMOS/M.'' Experiments using aluminum and scotchply composite laminates were conducted to verify the results. An optimal design for size and number of stiffeners for a given loading condition has been achieved. Investigations have also been carried out to find the effect of transverse shear on the span-wise normal stress.

  7. Brightness of synchrotron radiation from undulators and bending magnets

    International Nuclear Information System (INIS)

    We consider the maximum of the Wigner distribution (WD) of synchrotron radiation (SR) fields as a possible definition of SR source brightness. Such figure of merit was originally introduced in the SR community by Kim. The brightness defined in this way is always positive and, in the geometrical optics limit, can be interpreted as maximum density of photon flux in phase space. For undulator and bending magnet radiation from a single electron, the WD function can be explicitly calculated. In the case of an electron beam with a finite emittance the brightness is given by the maximum of the convolution of a single electron WD function and the probability distribution of the electrons in phase space. In the particular case when both electron beam size and electron beam divergence dominate over the diffraction size and the diffraction angle, one can use a geometrical optics approach. However, there are intermediate regimes when only the electron beam size or the electron beam divergence dominate. In this asymptotic cases the geometrical optics approach is still applicable, and the brightness definition used here yields back once more the maximum photon flux density in phase space. In these intermediate regimes we find a significant numerical disagreement between exact calculations and the approximation for undulator brightness currently used in literature. We extend the WD formalism to a satisfactory theory for the brightness of a bending magnet. We find that in the intermediate regimes the usually accepted approximation for bending magnet brightness turns out to be inconsistent even parametrically.

  8. PERMEABILITY OF SALTSTONE MEASUREMENT BY BEAM BENDING

    International Nuclear Information System (INIS)

    One of the goals of the Saltstone variability study is to identify (and, quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. A performance property for Saltstone mixes that is important but not routinely measured is the liquid permeability or saturated hydraulic conductivity of the cured Saltstone mix. The value for the saturated hydraulic conductivity is an input into the Performance Assessment for the SRS Z-Area vaults. Therefore, it is important to have a method available that allows for an accurate and reproducible measurement of permeability quickly and inexpensively. One such method that could potentially meet these requirements for the measurement of saturated hydraulic conductivity is the technique of beam bending, developed by Professor George Scherer at Princeton University. In order to determine the feasibility of this technique for Saltstone mixes, a summer student, David Feliciano, was hired to work at Princeton under the direction of George Scherer. This report details the results of this study which demonstrated the feasibility and applicability of the beam bending method to measurement of permeability of Saltstone samples. This research effort used samples made at Princeton from a Modular Caustic side solvent extraction Unit based simulant (MCU) and premix at a water to premix ratio of 0.60. The saturated hydraulic conductivities for these mixes were measured by the beam bending technique and the values determined were of the order of 1.4 to 3.4 x 10-9 cm/sec. These values of hydraulic conductivity are consistent with independently measured values of this property on similar MCU based mixes by Dixon and Phifer. These values are also consistent with the hydraulic conductivity of a generic Saltstone mix measured by Langton in 1985. The high water to premix ratio used for Saltstone along with the relatively low degree of hydration for MCU

  9. Demonstration model of LEP bending magnet

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    To save iron and raise the flux density, the LEP bending magnet laminations were separated by spacers and the space between the laminations was filled with concrete. This is a demonstration model, part of it with the spaced laminations only, the other part filled with concrete.

  10. AA, assembly of wide bending magnet

    CERN Multimedia

    1980-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets; BST, short and wide; BLG, long and narrow). The wide ones had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. Here we see the copper coils being hoisted onto the lower half of a BST. See also 7811105, 8006050. For a BLG, see 8001044.

  11. Damage Analysis of Rectangular Section Composite Beam under Pure Bending

    Science.gov (United States)

    Liu, Yiping; Xiao, Fan; Liu, Zejia; Tang, Liqun; Fang, Daining

    2013-02-01

    Laminated composite beams are commonly used in engineering applications involving macro to nano structures. Based on the assumption that plain sections remain plain after deformation, this paper analyzes stress distributions in cross-ply laminated composite beams with rectangular cross-sections, and formulates the basic damage equations through Kachanov's damage definition and Janson's failure criterion. The location of the neutral axis and the ultimate bending moment are obtained for pure bending cases. The effect of the elastic modulus of the two layers on the damage evolution is analyzed; a reasonable damage composite beam model is proposed to predict the ultimate bending moment.

  12. Bending and rotational behaviour of semi-continuous composite beams

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Stresses and deflections were measured in various semi-continuous composite beams.The bending and rotational capacities of the composite connections were measured in terms of beam curvatures and deflections by using two full-scale semi-rigid composite frames with monotonic loadings.The effect of semi-rigid connections on the performance of composite beams with various loadings was compared with predictions and codes.The tests show that the semi-continuous composite beams are more economic and effective than the simple or continuous composite beams.The semi-rigid connections affect the bending capacities and beam deflections,so the connection behavior should be considered in the design of composite beams.Yielding analysis of the steel beam bottom flange has some influence on the deflection calculation of composite beams.

  13. Wooden Model of Wide AA Bending Magnet

    CERN Multimedia

    1978-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets: BLG, long and narrow; BST, short and wide). A wide one had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. A wooden model was build in 1978, to gain dimensional experience. Here, Peter Zettwoch, one of the largest men at CERN at that time, is putting a hand in the mouth of the wooden BST monster.

  14. SRI CAT Section 1 bending magnet beamline description

    International Nuclear Information System (INIS)

    This report discusses: APS bending magnet source; beamline layout; beamline optical components; beamline operation; time-resolved studies station; polarization studies station; and commissioning and operational schedule

  15. Dynamics of fast charged particle beam rotation in bended crystals

    International Nuclear Information System (INIS)

    Dynamics of fast charged particle beam rotation in a bended monocrystal is considered. Face and volume mechanisms of capture in channels are taken into account simultaneously in the model presented. Functions of distribution in transverse energies (φ) of channeled and dechanneled particles are obtained. Charge-energy ''scale invariance'' in ion channeling with charge Z in a bended crystal determined by scale parameter W=pv/Z (p and v are pulse and velocity local to transverse planes) follows from the model presented

  16. Vacuum Chamber for the Booster Bending Magnets

    CERN Multimedia

    1974-01-01

    To minimize eddy currents, induced by the rising magnetic field, the chamber was made from thin stainless steel of high specific electric resistance. For mechanical stength, it was corrugated in a hydro-forming process. The chamber is curved, to follow the beam's orbital path. Under vacuum, the chamber tends to staighten, the ceramic spacer along half of its length keeps it in place (see also 7402458).

  17. Field measurement for large bending magnets

    Energy Technology Data Exchange (ETDEWEB)

    Lazzaro, A. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Cappuzzello, F. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95123 Catania (Italy)], E-mail: cappuzzello@lns.infn.it; Cunsolo, A.; Cavallaro, M. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Foti, A. [Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95123 Catania (Italy); INFN-Sezione di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Orrigo, S.E.A.; Rodrigues, M.R.D.; Winfield, J.S. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy)

    2008-02-01

    The results of magnetic field measurements of the large bending magnet of the MAGNEX spectrometer are presented. The experimental values are used to build an Enge function by the least-squares method. The resulting field is compared to the measured one, showing too large deviation for application to ray reconstruction techniques. Similarly, the experimental values are compared with results from a three-dimensional finite elements calculation. Again the deviations between measured and calculated field are too large for a direct application of the latter to ray reconstruction, while its reliability is sufficient for analysis purposes. In particular, it has been applied to study the effect of the inaccuracies in the probe location and orientation on the precision of field reconstruction, and to establish the requirements for the field interpolation. These inaccuracies are found to be rather important, especially for the transversal components of the field, with the consequence that their effect on the reconstructed field should be minimized by special interpolation algorithms.

  18. Bending of magnetic filaments under a magnetic field

    Science.gov (United States)

    Shcherbakov, Valera P.; Winklhofer, Michael

    2004-12-01

    Magnetic beads and superparamagnetic (SP) colloid particles have successfully been employed for micromechanical manipulation of soft material, in situ probing of elastic properties, and design of smart materials (ferrogels). Here we derive analytical expressions for the equilibrium shape of magnetic fibers, considering two end-member cases, (a) SP or single-domain particles concentrated at the free end of cantilevered rods or tubes, and (b) filaments consisting of SP particles, with this case being mathematically equivalent to tubes containing SP particles. Our analysis yields also metastable equilibrium states (MES’s), which only exist above a critical filament length, but become more stable with increasing magnetic field. The MES’s for case (a) are, like the ground state, circular arcs, but more strongly bent. The multiform MES’s in case (b), which comprise hairpin, sinuous, or even closed shapes, have recently been observed in experiments, too. We also study the effect of gravity on the balance between bending and magnetic energy, which leads to curves with inflection point if the influence of gravity is stronger than that of the magnetic field. Because of their simple experimental realization, case (a) magnetic filaments are deemed highly suitable for micromechanical experiments on long chains of polymer molecules. Another potential application of cantilevered magnetic filaments with magnetic material attached to the free end is in scanning probe microscopes. Because the magnetic field due to the magnetic tip is comparatively weak, the magnetization structure of the sample to be investigated would not be affected by the probe. Thus, for the examination of magnetically soft materials, probes in the form of magnetic filaments may hold advantages over tips usually employed in magnetic force microscopy.

  19. Bending analysis of laminated composite and sandwich beams according to refined trigonometric beam theory

    OpenAIRE

    Sayyad A. S.; Ghugal Y. M.; Naik N. S.

    2015-01-01

    A trigonometric beam theory (TBT) is developed for the bending analysis of laminated composite and sandwich beams considering the effect of transverse shear deformation. The axial displacement field uses trigonometric function in terms of thickness coordinate to include the effect of transverse shear deformation. The transverse displacement is considered as a sum of two partial displacements, the displacement due to bending and the displacement due to transverse sheari...

  20. Space charge effects in a bending magnet system

    International Nuclear Information System (INIS)

    In order to examine problems and phenomena associated with space charge in a beam bending system, the beam dynamics code HICURB has been written. Its principal features include momentum variations, vertical and horizontal envelope dynamics coupled to the off-axis centroid, curvature effect on fields, and images. Preliminary results for an achromatic lattice configuration are presented

  1. A mechanical model for FRP-strengthened beams in bending

    Directory of Open Access Journals (Sweden)

    P. S. Valvo

    2012-10-01

    Full Text Available We analyse the problem of a simply supported beam, strengthened with a fibre-reinforced polymer (FRP strip bonded to its intrados and subjected to bending couples applied to its end sections. A mechanical model is proposed, whereby the beam and FRP strip are modelled according to classical beam theory, while the adhesive and its neighbouring layers are modelled as an interface having a piecewise linear constitutive law defined over three intervals (elastic response – softening response – debonding. The model is described by a set of differential equations with appropriate boundary conditions. An analytical solution to the problem is determined, including explicit expressions for the internal forces, displacements and interfacial stresses. The model predicts an overall non-linear mechanical response for the strengthened beam, ranging over several stages: from linearly elastic behaviour to damage, until the complete detachment of the FRP reinforcement.

  2. Modeling of a cracked beam section under bending

    International Nuclear Information System (INIS)

    Numerical simulations are widely used to study the dynamical behaviour of turbines cracked shaft as this event is rare and then doesn't enable to have an useful industrial feedback. A new method, which enables to calculate the constitutive law of a cracked beam subjected to bending was previously proposed. Based on three-dimensional computations taking into account the unilateral contact between both lips of the crack, it consists in defining a (non-linear) behaviour relation between the bending moment applied to the cracked section and the resulting field of displacements, compatible with the beam theory so that it can be used in rotor-dynamics software. The aim of this paper is to complete this first model by adding shear effects. For some crack geometries, a simpler model can be derived, based on the recognition that bending moments and shear forces are uncoupled and the dependence of the behaviour law with respect to the shear forces becomes linear. Developments have been achieved in this case and some results of the validation tests are shown. (authors)

  3. Sensor enabled closed-loop bending control of soft beams

    Science.gov (United States)

    Case, Jennifer C.; White, Edward L.; Kramer, Rebecca K.

    2016-04-01

    Control of soft-bodied systems is challenging, as the absence of rigidity typically implies distributed deformations and infinite degrees-of-freedom. In this paper, we demonstrate closed-loop control of three elastomer beams that vary in bending stiffness. The most stiff beam is comprised of a single prismatic structure made from a single elastomer. In the next beam, increased flexibility is introduced via an indentation in the elastomer, forming a joint. The most flexible beam uses a softer elastomer in the joint section, along with an indentation. An antagonistic pair of actuators bend the joint while a pair of liquid-metal-embedded strain sensors provide angle feedback to a control loop. We were able to achieve control of the system with a proportional-integral-derivative control algorithm. The procedure we demonstrate in this work is not dependent on actuator and sensor choice and could be applied to to other hardware systems, as well as more complex multi-joint robotic structures in the future.

  4. Prevention of thermal bending of multilayered beams and plates

    Science.gov (United States)

    Yang, J. C. S.

    1975-01-01

    By adding an extra layer to multilayer beams or plates of different isotropic materials, it is possible to prevent the thermal bending of these materials. With the proper selection of thermoelastic properties the curvature produced prior to this addition would be eliminated. Several numerical examples are presented for various temperature distributions. A simple experiment was conducted, involving the addition of a brass strip to a bimetallic strip made of aluminum and steel at room temperature. The trimetal strip was placed in a furnace and remained straight for varying temperatures.

  5. Local Deplanation Of Double Reinforced Beam Cross Section Under Bending

    Science.gov (United States)

    Baltov, Anguel; Yanakieva, Ana

    2015-12-01

    Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model's plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB).

  6. Local Deplanation Of Double Reinforced Beam Cross Section Under Bending*

    Directory of Open Access Journals (Sweden)

    Baltov Anguel

    2015-12-01

    Full Text Available Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model’s plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB.

  7. DESIGN REPORT OF THE TRANSFER LINE BENDING MAGNETS FOR LINAC4

    CERN Document Server

    Thonet, P

    2013-01-01

    A review of a preliminary design of the H-shape Linac4 transfer line bending magnet described in EDMS 1252682 evidenced that the magnetic field quality has to be improved. This new report describes the modifications performed on the initial design to meet the field quality requirements imposed by beam optics specifications and provides a comprehensive list of the magnet parameters. It will be the reference for the write-up of the technical specifications for the purchase of the 6 magnets needed for Linac4.

  8. Bending Moment Decrease of Reinforced Concrete Beam Supported by Additional CFRP

    Directory of Open Access Journals (Sweden)

    Mykolas Daugevičius

    2011-04-01

    Full Text Available The calculation method of reinforced concrete beam with additional CFRP composite is proposed in this article. This method estimates tangential angular concrete deformations in tensioned beam layers between steel and bonded carbon fiber reinforced polymer. The horizontal slip of CFRP composite reduce beam bending moment capacity. An additional coefficient to reduce CFRP resultant force is necessary for better precision of bending moment capacity. Also, various calculation methods of bending moment capacity are considered. Article in Lithuanian

  9. Bending of a nonlinear beam reposing on an unilateral foundation

    Directory of Open Access Journals (Sweden)

    Machalová J.

    2011-06-01

    Full Text Available This article is going to deal with bending of a nonlinear beam whose mathematical model was proposed by D. Y. Gao in (Gao, D. Y., Nonlinear elastic beam theory with application in contact problems and variational approaches,Mech. Research Communication, 23 (1 1996. The model is based on the Euler-Bernoulli hypothesis and under assumption of nonzero lateral stress component enables moderately large deflections but with small strains. This is here extended by the unilateralWinkler foundation. The attribution unilateral means that the foundation is not connected with the beam. For this problem we demonstrate a mathematical formulation resulting from its natural decomposition which leads to a saddle-point problem with a proper Lagrangian. Next we are concerned with methods of solution for our problem by means of the finite element method as the paper (Gao, D. Y., Nonlinear elastic beam theory with application in contact problems and variational approaches, Mech. Research Communication, 23 (1 1996 has no mention of it. The main alternatives are here the solution of a system of nonlinear nondifferentiable equations or finding of a saddle point through the use of the augmented Lagrangian method. This is illustrated by an example in the final part of the article.

  10. Vacuum Chamber for the Booster Bending Magnets

    CERN Multimedia

    1974-01-01

    To minimise eddy currents, induced by the rising magnetic field, the chamber was made from thin stainless steel of high specific electric resistance. For mechanical strength, it was corrugated in a hydro-forming process. The cross-section was designed for maximum strength and maximum aperture. To accept particles with simultaneous large amplitudes in both planes, the cross-section approaches a rectangular shape (see also 7402463).

  11. Bending of metal-filled carbon nanotube under electron beam irradiation

    Directory of Open Access Journals (Sweden)

    Abha Misra

    2012-03-01

    Full Text Available Electron beam irradiation induced, bending of Iron filled, multiwalled carbon nanotubes is reported. Bending of both the carbon nanotube and the Iron contained within the core was achieved using two approaches with the aid of a high resolution electron microscope (HRTEM. In the first approach, bending of the nanotube structure results in response to the irradiation of a pristine kink defect site, while in the second approach, disordered sites induce bending by focusing the electron beam on the graphite walls. The HRTEM based in situ observations demonstrate the potential for using electron beam irradiation to investigate and manipulate the physical properties of confined nanoscale structures.

  12. Design of the Taiwan contract bending-magnet beamline at SPring-8

    International Nuclear Information System (INIS)

    The BL12B2 beamline at SPring-8 is a Taiwan contract bending magnet beamline designed for multiple applications. This beamline is able to provide different operational modes of white beam and monochromatic photons of energies from 5 to 70 keV. The end stations under construction include a micro-beam station, a MAD protein crystallography station, a high-resolution X-ray scattering/diffraction station, and an EXAFS station. This beamline has been installed and will be ready for user operation in the spring of 2001

  13. Bending and free vibration of functionally graded beams using various higher-order shear deformation beam theories

    OpenAIRE

    Thai, Huu-Tai; Vo, Thuc

    2012-01-01

    In this paper, various higher-order shear deformation beam theories for bending and free vibration of functionally graded beams are developed. The developed theories account for higher-order variation of transverse shear strain through the depth of the beam, and satisfy the stress-free boundary conditions on the top and bottom surfaces of the beam. A shear correction factor, therefore, is not required. In addition, these theories have strong similarities with Euler–Bernoulli beam theory in so...

  14. Large-Angle Bending Transport of Microparticles by Acoustic Half-Bessel Beams

    CERN Document Server

    Li, Yixiang; Xu, Shengjun; Ke, Manzhu; Liu, Zhengyou

    2014-01-01

    Conventional microparticle transports by light or sound are realized along a straight line. Recently, this limit has been overcome in optics as the growing up of the self-accelerating Airy beams, which are featured by many peculiar properties, e.g., bending propagation, diffraction-free and self-healing. However, the bending angles of Airy beams are rather small since they are only paraxial solutions of the two-dimensional (2D) Helmholtz equation. Here we propose a novel micromanipulation by using acoustic Half-Bessel beams, which are strict solutions of the 2D Helmholtz equation. Compared with that achieved by Airy beams, the bending angle of the particle trajectory attained here is much steeper (exceeding 90o). The large-angle bending transport of microparticles, which is robust to complex scattering environment, enables a wide range of applications from the colloidal to biological sciences.

  15. Measurement of the prestress transfer length and load bending tests on an actual pretension type nan-magnetic beam provided with CFRP strand as tendon; CFRP yorisen wo kinchozai ni shiyoshita puretenshon hoshiki jitsubutsu hi jiseiryo no puresutoresu dentatsu cho sokutei shiken oyobi mage saika shiken

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, Y. [P-S Corp., Tokyo (Japan); Nakata, A.; Akashi, K.

    1996-01-30

    When a new material of fiber reinforced plastics-strand of carbon fiber reinforced plastics(CFRP)-is used as an alternative to a PC steel material and low magnetic aggregates are selected for a demagnetized structure, it is considered that the physical and mechanical behaviors of such a PC member differ from that of the ordinary PC member. Therefore, in this report, characteristics of the new member are clarified and a design method for an actual low magnetic PC structure is discussed. Firstly, the main beam is outlined and an analysis is made on the prestress transfer length on the basis of stress variations measured on tendons, and the fact that the provision of stirrups in the beam terminal parts can prevent from its fracturing and cracking that may otherwise occurred by introduction of prestresses is demonstrated. Then the main beam displacement and the states of stress and crack of the structure members are examined. It is indicated from the findings that the ordinary PC design method can be applied to a design for which no crack is permitted, but the tendon rupture should be regarded as the bending fracture of the beam itself for beam designing purposes. Some future items for study are also shown. 17 refs., 10 figs., 7 tabs.

  16. Polarization measurement and vertical aperture optimization for obtaining circularly polarized bend-magnet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kortright, J.B.; Rice, M.; Hussain, Z. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Growing interest in utilizing circular polarization prompted the design of bend-magnet beamline 9.3.2 at the Advanced Light Source, covering the 30-1500 eV spectral region, to include vertical aperturing capabilities for optimizing the collection of circular polarization above and below the orbit plane. After commissioning and early use of the beamline, a multilayer polarimeter was used to characterize the polarization state of the beam as a function of vertical aperture position. This report partially summarizes the polarimetry measurements and compares results with theoretical calculations intended to simulate experimental conditions.

  17. Performance of composite I-beams under axial compression and bending load modes

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Y.A.; Ali, F.A.; Sahari, B.B.; Saad, E.M.A

    2005-04-15

    An experimental and finite-element analyses for glass/epoxy composite I-beams have been carried out. Four, six, eight and 10 layers of woven fabric glass/epoxy composite I-beams were fabricated by a hand lay-up (molding) process. Quasi-static axial crushing and bending loading modes were used for this investigation. The load-displacement response was obtained and the energy absorption values were calculated for all the composite I-beams. Three tests were done for each composite I-beams type and each loading case for the results conformation. The second part of this study includes the elastic behavior of composite I-beams of the same dimensions and materials using finite-element analysis. The woven fabric glass/epoxy composite I-beams mechanical properties have been obtained from tensile tests. Results from this investigation show that the load required and the specific energy absorption for composite I-beams under axial compression load were higher than those for three and four point bending. On the other hand, the loads required for composite I-beams under four point bending were higher than those for three point bending, while the specific energy absorption for composite I-beams under three point bending were higher than those for four point bending. The first crushing loads difference between the experimental and finite-element results fell in the 3.6-10.92% range for axial compression tests, while fell in the 1.44-12.99% and 4.94-22.0% range for three and four point bending, respectively.

  18. Quasi-static and dynamical bending of a cantilever poroelastic beam

    Institute of Scientific and Technical Information of China (English)

    YANG Yi; LI Li; YANG Xiao

    2009-01-01

    Based on the theory of porous media, the quasi-static and dynamical bending of a cantilever poroelastic beam subjected to a step load at its free end is investigated, and the influences of its permeability on bending deformation is examined.The initial boundary value problems for dynamical and quasi-static responses are solved with the Laplace transform technique,and the deflections, the bending moments of the solid skeleton and the equivalent couples of the pore fluid pressure are shown in figures. It is shown that the dynamical and quasi-static behavior of the saturated poroelastic beam depends closely on the permeability conditions at the beam ends. Under the different permeability conditions, the deflections of the beam may oscillate or not. The Mandel-Cryer effect also exists in liquid-saturated poroelastic beams.

  19. Calculation of closed orbit errors due to misalignment of combined function magnets with large bend angle

    International Nuclear Information System (INIS)

    The effects of different misalignments of bending magnets with very small bending radius (ρ b = 180, in some cases 360 degree) are discussed. These magnets are represented by n segments. A method is given to calculate misalignments of a segment at any α b bend angle from the misalignments of the whole (rigid) magnet. This method is then used to calculate distorted closed orbits for the SXLS ring. 6 refs., 10 figs., 1 tab

  20. Modelling the double cantilever beam test with bending moments by using bilinear discontinuous cohesive laws

    DEFF Research Database (Denmark)

    Valvo, Paolo S.; Sørensen, Bent F.; Toftegaard, Helmuth Langmaack

    2015-01-01

    A theoretical model of the double cantilever beam tests with bending moments (DCB-UBM) is presented. The specimen is modelled as the assemblage of two laminated beams connected by a cohesive interface. It is assumed that the traction-separation laws – i.e. the relationships between the interfacial...

  1. Bending resistance of composite steel truss and concrete beam

    OpenAIRE

    Silva, Mickael; Piloto, P.A.G.; Roque, Sérgio; VILA REAL Paulo; Plizzari, Giovanni

    2013-01-01

    This study presents the numerical simulation of the bending resistance of CSTCB in stage 1 (element made only by the self-supported steel truss and base plate). Two different base plates were considered (Steel and Concrete) and two different types of steel trusses (Type I and II). The numerical results are also compared with analytical results, assuming the full interaction between steel truss and concrete, neglecting the tensile strength of concrete, considering the effective area of concret...

  2. Large deflection and rotation of Timoshenko beams with frictional end supports under three-point bending

    Science.gov (United States)

    Li, Dao-Kui; Li, Xian-Fang

    2016-08-01

    Three-point bending of a beam is studied based on the Timoshenko beam theory. Large deflection and large rotation of a beam resting on simple supports with friction are calculated for a concentrated force acting at the midspan. Using the Lagrangian kinematic relations, a system of non-linear differential equations are obtained for a prismatic shear-deformable Timoshenko beam. Exact solutions for the deflection, horizontal displacement, and rotation of cross-section are derived analytically. Two deflections of small and large scale exist under three-point bending. The solutions corresponding to linearized model coincide with the well-known solutions to the classical Timoshenko beams. Numerical calculations are carried out to show the effect of the important parameters such as shear rigidity of the beam and the coefficient of friction at the contact position between the beam and supports on the deflection. The load-deflection curves are graphically presented. A comparison of large deflections and large rotations with their classical counterparts and with experimental data is made. The obtained results are useful in safety design of linear and non-linear beams subject to three-point bending.

  3. Polarization measurement and vertical aperture optimization for obtaining circularly polarized bend-magnet radiation

    International Nuclear Information System (INIS)

    Using multilayer linear polarizers, we have characterized the polarization state of radiation from bend-magnet beamline 9.3.2 at the Advanced Light Source as a function of vertical opening angle at photon energies of 367 and 722 eV. Both a fine slit and a coarse semi-aperture were stepped across the beam to accept different portions of the vertical radiation fan. Polarimetry yields the degree of linear polarization directly and the degree of circular polarization indirectly assuming an immeasurably small amount of unpolarized radiation based on the close agreement of the theoretical and experimental results for linear polarization. The results are in good agreement with theoretical calculations, with departures from theory resulting from uncertainty in the effective aperture of the measured beam. The narrow 0.037-mrad aperture on the orbit plane transmits a beam whose degree of linear polarization exceeds 0.99 at these energies. The wide semi-aperture blocking the beam from above and below transmits a beam with a maximum figure of merit, given by the square root of flux times the degree of circular polarization, when the aperture edge is on the orbit plane thus blocking only half of the total available flux. copyright 1996 American Institute of Physics

  4. Polarization measurement and vertical aperture optimization for obtaining circularly polarized bend-magnet radiation

    International Nuclear Information System (INIS)

    Using multilayer linear polarizers, we have studied the polarization state of radiation from bend magnet beamline 9.3.2 at Advanced Light Source as function of vertical oping angle at photon energies 367 and 722 eV. Both a fine slit and a coarse semi-aperture were stepped across the beam to accept different parts of the vertical radiation fan. Polarimetry yields the degree of linear polarization directly and the degree of circular polarization indirectly assuming an immeasurably small amount of unpolarized radiation based on close agreement of theory and experiment for linear polarization. Results are in good agreement with theoretical calculations, with departures from theory owing to uncertainty in effective aperture of the measured beam. The narrow 0.037 mrad aperture on the orbit plane transmits a beam whose degree of linear polarization exceeds 0.99 at these energies. The wide semi-aperture blocking the beam from above and below transmits a beam with a max figure of merit, given by the square root of flux times degree of circular polarization, when the aperture edge is on the orbit plane thus blocking only half of the total available flux

  5. Magnetic Field Measurements in Beam Guiding Magnets

    CERN Document Server

    Henrichsen, K N

    1998-01-01

    Electromagnets used as beam guiding elements in particle accelerators and colliders require very tight tole-rances on their magnetic fields and on their alignment along the particle path. This article describes the methods and equipment used for magnetic measurements in beam transport magnets. Descriptions are given of magnetic resonance techniques, various induction coil methods, Hall generator measurements, the fluxgate magnetometer as well as the recently developed method of beam based alignment. References of historical nature as well as citations of recent work are given. The present commercial availability of the different sensors and asso-ciated equipment is indicated. Finally we shall try to analyze possible future needs for developments in those fields.

  6. Suite of three protein crystallography beamlines with single superconducting bend magnet as the source

    Energy Technology Data Exchange (ETDEWEB)

    MacDowell, Alastair A.; Celestre, Richard S.; Howells, Malcolm; McKinney, Wayne; Krupnick, James; Cambie, Daniella; Domning, Edward E; Duarte, Robert M.; Kelez, Nicholas; Plate, David W.; Cork, Carl W.; Earnest, Thomas N.; Dickert, Jeffery; Meigs, George; Ralston, Corie; Holton, James M.; Alber, Thomas; Berger, James M.; Agard, David A.; Padmore, Howard A.

    2004-08-01

    At the Advanced Light Source (ALS), three protein crystallography (PX) beamlines have been built that use as a source one of the three 6 Tesla single pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single pole superconducting bend magnets enables the development of a hard x-ray program on a relatively low energy 1.9 GeV ring without taking up insertion device straight sections. The source is of relatively low power, but due to the small electron beam emittance, it has high brightness. X-ray optics are required to preserve the brightness and to match the illumination requirements for protein crystallography. This was achieved by means of a collimating premirror bent to a plane parabola, a double crystal monochromator followed by a toroidal mirror that focuses in the horizontal direction with a 2:1 demagnification. This optical arrangement partially balances aberrations from the collimating and toroidal mirrors such that a tight focused spot size is achieved. The optical properties of the beamline are an excellent match to those required by the small protein crystals that are typically measured. The design and performance of these new beamlines are described.

  7. Suite of three protein crystallography beamlines with single superconducting bend magnet as the source

    International Nuclear Information System (INIS)

    At the Advanced Light Source (ALS), three protein crystallography (PX) beamlines have been built that use as a source one of the three 6 Tesla single pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single pole superconducting bend magnets enables the development of a hard x-ray program on a relatively low energy 1.9 GeV ring without taking up insertion device straight sections. The source is of relatively low power, but due to the small electron beam emittance, it has high brightness. X-ray optics are required to preserve the brightness and to match the illumination requirements for protein crystallography. This was achieved by means of a collimating premirror bent to a plane parabola, a double crystal monochromator followed by a toroidal mirror that focuses in the horizontal direction with a 2:1 demagnification. This optical arrangement partially balances aberrations from the collimating and toroidal mirrors such that a tight focused spot size is achieved. The optical properties of the beamline are an excellent match to those required by the small protein crystals that are typically measured. The design and performance of these new beamlines are described

  8. Charge Stripper Effects on Beam Optics in 180-degree Bending Section of RISP Linac

    CERN Document Server

    Jang, Ji-Ho; Song, Jeong Seog

    2016-01-01

    The RAON, a superconducting linear accelerator for RISP (Rare Isotope Science Project), will use a charge stripper in order to increase the charge states of the heavy ions for effective acceleration in the higher energy part of the linac. The charge stripper affects the beam qualities by scattering when the heavy ions go through the charge stripper. Moreover we have to select and accelerate proper charge states between 77+ and 81+ for uranium beam case in order to satisfy the beam power requirement at an IF (Inflight Fragmentation) target. This work focuses on the beam optics affected by the charge stripper in the 180-dgree bending section.

  9. Variational Principles for Bending and Vibration of Partially Composite Timoshenko Beams

    Directory of Open Access Journals (Sweden)

    Halil Özer

    2014-01-01

    Full Text Available Variational principles are established for the partially composite Timoshenko beam using the semi-inverse method. The principles are derived directly from governing differential equations for bending and vibration of the beam considered. It is concluded that the semi-inverse method is a powerful tool for searching for variational principles directly from the governing equations. Comparison between our results and the results reported in literature is given.

  10. Bending performance of concrete beams strengthened with textile reinforced mortar TRM

    OpenAIRE

    Gil Espert, Lluís; Escrig Pérez, Christian; Bernat Masó, Ernest

    2013-01-01

    This work presents a method of strengthening concrete structures based on textiles of high strength and mortars. The combination of textiles and mortars produces a new composite material with cementitious matrix. This material can be used for the reinforcement of concrete beams under bending loads. We tested several combinations of fibers: glass, Poliparafenil Benzobisoxazol (PBO), steel and carbon fibers with mortar and we used them to reinforce precast concrete beams. All the specimens were...

  11. Algebraic-numeric calculations of proton trajectories in bending magnets of synchrotron accelerator

    International Nuclear Information System (INIS)

    We study a solution of nonlinear differential equation of the second degree which describes the trajectories of the charged particles in the fully inhomogeneous field of cyclic accelerator. We give the clear mathematical statement of the problem and algorithm of solving it. We realize this algorithm on the Computer Algebra System REDUCE 3.2. Our algorithm is based both on the existence of exact solution in terms of hyperelliptic integral and on the existence of power series solution of specific inversion problem. We use the known REDUCE procedures of operation on generalized power series. Using the FORTRAN code we give the numerical analysis of these series in the close relation to the concrete physical situation. We apply our results to the beam dynamics modelling of the protons in the bending magnets in synchrotron accelerator. 18 refs.; 2 figs

  12. Material-point Method Analysis of Bending in Elastic Beams

    DEFF Research Database (Denmark)

    Andersen, Søren Mikkel; Andersen, Lars

    The aim of this paper is to test different types of spatial interpolation for the materialpoint method. The interpolations include quadratic elements and cubic splines. A brief introduction to the material-point method is given. Simple liner-elastic problems are tested, including the classical...... cantilevered beam problem. As shown in the paper, the use of negative shape functions is not consistent with the material-point method in its current form, necessitating other types of interpolation such as cubic splines in order to obtain smoother representations of field quantities. It is shown that the...

  13. Material-Point Method Analysis of Bending in Elastic Beams

    DEFF Research Database (Denmark)

    Andersen, Søren Mikkel; Andersen, Lars

    2007-01-01

    The aim of this paper is to test different types of spatial interpolation for the material-point method. The interpolations include quadratic elements and cubic splines. A brief introduction to the material-point method is given. Simple liner-elastic problems are tested, including the classical...... cantilevered beam problem. As shown in the paper, the use of negative shape functions is not consistent with the material-point method in its current form, necessitating other types of interpolation such as cubic splines in order to obtain smoother representations of field quantities. It is shown that the...

  14. NUMERICAL PREDICTION OF COMPOSITE BEAM SUBJECTED TO COMBINED NEGATIVE BENDING AND AXIAL TENSION

    Directory of Open Access Journals (Sweden)

    MAHESAN BAVAN

    2013-08-01

    Full Text Available The present study has investigated the finite element method (FEM techniques of composite beam subjected to combined axial tension and negative bending. The negative bending regions of composite beams are influenced by worsen failures due to various levels of axial tensile loads on steel section especially in the regions near internal supports. Three dimensional solid FEM model was developed to accurately predict the unfavourable phenomenon of cracking of concrete and compression of steel in the negative bending regions of composite beam due to axial tensile loads. The prediction of quasi-static solution was extensively analysed with various deformation speeds and energy stabilities. The FEM model was then validated with existing experimental data. Reasonable agreements were observed between the results of FEM model and experimental analysis in the combination of vertical-axial forces and failure modes on ultimate limit state behaviour. The local failure modes known as shear studs failure, excess yielding on steel beam and crushing on concrete were completely verified by extensive similarity between the numerical and experimental results. Finally, a proper way of modelling techniques for large FEM models by considering uncertainties of material behaviour due to biaxial loadings and complex contact interactions is discussed. Further, the model is suggested for the limit state prediction of composite beam with calibrating necessary degree of the combined axial loads.

  15. Fuzzy analysis of serviceability limit state of slender steel beam under bending

    Energy Technology Data Exchange (ETDEWEB)

    Kala, Zdeněk; Valeš, Jan [Brno University of Technology, Faculty of Civil Engineering, Department of Structural Mechanics Vevefi St. 95, ZIP 602 00, Brno (Czech Republic)

    2015-03-10

    In the present paper, deformations of a beam under equal end moments solved with influence of lateral buckling are studied. It has been found by numerical studies that the lateral deflection of slender beam under major axis bending can be relatively high.The acceptability of high values of lateral deflections within the framework of serviceability limit state is discussed. In the next part of the paper, the limit value of maximum deflection was introduced as a fuzzy number. The fuzzy analysis of the maximum moment which causes the maximum deflection was carried out. The slendernesses of beams for which the serviceability limit state is the limiting state for design were identified.

  16. Duration of load behaviour of different sized straight timber beams subjected to bending in variable climate

    DEFF Research Database (Denmark)

    Hanhijärvi, A.; Galimard, P.; Hoffmeyer, Preben

    1998-01-01

    The paper is the second in a series which sums up the results of an extensive project to quantify the duration-of-load (DOL) effect on different sized timber beams in different climates. The paper deals with straight (unnotched) beams. The results of various DOL-tests of stepwise and constant...... bending of LVL and glulam beams are reported and results of modelling outlined. It is concluded that in cyclically varying climate large cross-sections are less affected by the DOL-effect than smaller ones. The results do not show marked difference between LVL and glulam in susceptibility to the DOL-effect...

  17. EFFECT OF CORROSION ON BOND BEHAVIOR AND BENDING STRENGTH OF REINFORCED CONCRETE BEAMS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    There is growing concern for corrosion damage in reinforced concrete structures with several decades' service. Pullout tests and beam tests were carried out to study the effect of reinforcement corrosion on the bond behavior and bending strength of reinforced concrete beams. The bond strength of plain bars and concrete initially increases with increasing corrosion, then declines. The turning point depends on the cracking of the concrete cover. The bond strength of deformed bars and concrete increases with corrosion up to a certain amount, but with progressive increase in corrosion, the bond strength decreases, and the cracking of the concrete cover seems to have no effect on the bond strength. On the basis of test data, the bond strength coefficient recommended here, which, together with the bond strength of uncorroded steel bars and concrete, can be used to easily calculate the bond strength of corroded steel bars and concrete. The bond strength coefficient proposed in this paper can be used to study the bond stress-slip relationship of corroded steel bars and concrete. The bending strength of corroded reinforced concrete beams declines with increasing reinforcement corrosion. Decreased bending strength of corroded RC beam is due to reduction in steel bar cross section, reduction of yield strength of steel bar, and reduction of bond capacity between steel bar and concrete.

  18. Damping of bending waves in truss beams by electrical transmission lines with PZT actuators

    Energy Technology Data Exchange (ETDEWEB)

    dell`Isola, F.; Vidoli, S. [Univ. di Roma `La Sapienza` (Italy). Dipt. di Ingegneria Strutturale e Geotecnica

    1998-11-01

    A new device to damp mechanical waves in modular truss beams has been proposed. It is based on the electro-mechanical coupling of the truss beam with an electrical transmission line by a line distribution of PZT actuators. It has been proved that extensional and torsional waves can be damped using a standard second-order transmission line, and that such a line is not suitable to damp bending waves. In the present paper, we propose to couple the beam with a fourth-order transmission line, obtained from the standard one by adding a voltage-driven current generator, thus electrically paralleling the structure of the bending wave equation. As a detailed description of the system would require huge numerical programming, to test qualitatively the efficiency of the proposed electro-mechanical coupling we consider a coarse continuum model of piezoelectro-mechanical (PEM) beams, using an identification procedure based on the principle of virtual power. We define the critical value for line impedance maximizing the electro-mechanical energy exchange for every wave frequency, thus proving that the electric damping of bending waves by distributed PZT control is technically feasible. (orig.) With 10 figs., 1 tab., 10 refs.

  19. Suppression of bending waves in a beam using resonators with different separation lengths.

    Science.gov (United States)

    Yang, Cheng; Cheng, Li

    2016-05-01

    This work is concerned with the suppression of a bending wave in a beam using resonators. Particular focus is put on the separation length between resonators. It is demonstrated that, for a beam with identical resonators attached at equal intervals, the bending wave transmission efficiency varies with respect to the separation length. The phenomena and the underlying physics are investigated by resorting to a simple beam model having two resonators resting on it. The two resonators are coupled over the segment through various bending wave components, comprising both propagating waves and evanescent waves, generated at the resonator locations where the beam encounters impedance discontinuities. The separation length, specifying the phase change of the propagating waves and the amplitude decay of the evanescent waves travelling from one resonator to the other, is thereby the parameter determining the extent to which the resonators would be coupled and the degree of the power that is transmitted. Results show, qualitatively, the difference in the working mechanism of the resonators in different separation length regions, with criteria being defined to distinguish those regions. Particularly, in the intermediate separation region, the evanescent waves are shown to play an important role in the coupling and are responsible for transmitting power, comparable with that transmitted by propagating waves, to the far field. PMID:27250132

  20. Load-to-failure bending test of wood composite beams connected by gang nail

    Directory of Open Access Journals (Sweden)

    A.V. Karelskiy

    2015-03-01

    Full Text Available The results of a bending test of wood composite beams connected by gang nail are presented in this paper. Two types of wood composite beams fracture were observed: brittle and ductile. In addition, a numerical model of wood composite beams was produced and the results of the numerical investigations were analyzed. Compliance of connection «gang nail – wood» was considered by means of input elements with a reduced modulus of elasticity in the numerical model. Then the theoretical and experimental results of stress and strain state of a composite beam with gang nail were compared. The conclusion was made about the efficiency of gang nail application for increased shear resistance of wood composite structures not only for reinforcement but also for production of new beam structures.

  1. Ion-beam-induced bending of freestanding amorphous nanowires: The importance of the substrate material and charging

    International Nuclear Information System (INIS)

    Ion-beam irradiation offers great flexibility and controllability in the construction of freestanding nanostructures with multiple advanced functionalities. Here, we present and discuss the bending of free-standing nanowires, against, towards, and ultimately parallel to a flux of directional ion irradiation. Bending components both along and perpendicular to the incident ion beam were observed, and the bending behavior was found to depend both on the ion beam scanning strategy and on the conductivity of the supporting substrate. This behavior is explained by an ion-irradiation-related electrostatic interaction. Our findings suggest the prospect of exploiting this technique to engineer 3D nanostructures for advanced applications.

  2. Experiment and prediction in the bending of a nickel beam at 200/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Mautz, J.A.; Hart, E.W.

    1979-05-01

    The results of an experiment on the bending response of a Nickel prismatic beam under four point loading at 200/sup 0/C are described. The specimens have been subjected to histories of steady applied moment with a sequence of step changes both positive and negative. The measured results are compared with predictions based on Hart's constitutive equations. The experimental conditions and procedures are described. The experiment and the predictions are compared with prior studies.

  3. Neutral beams for magnetic fusion

    International Nuclear Information System (INIS)

    Significant advances in forming energetic beams of neutral hydrogen and deuterium atoms have led to a breakthrough in magnetic fusion: neutral beams are now heating plasmas to thermonuclear temperatures, here at LLL and at other laboratories. For example, in our 2XIIB experiment we have injected a 500-A-equivalent current of neutral deuterium atoms at an average energy of 18 keV, producing a dense plasma (1014 particles/cm3) at thermonuclear energy (14 keV or 160 million kelvins). Currently, LLL and LBL are developing beam energies in the 80- to 120-keV range for our upcoming MFTF experiment, for the TFTR tokamak experiment at Princeton, and for the Doublet III tokamak experiment at General Atomic. These results increase our long-range prospects of producing high-intensity beams of energies in the hundreds or even thousands of kilo-electron-volts, providing us with optimistic extrapolations for realizing power-producing fusion reactors

  4. MTN magnet for the SPS extracted beam.

    CERN Multimedia

    1976-01-01

    This type of dipole magnet was used in the extracted beam lines of the North Area. It shows an opening for three different proton beam lines: a primary extracted proton beam, split by an upstream magnetic beam splitter (see photo 7612017) into three separated beams passes through different parts of its aperture: right, left up, left down. These magnets were designed to be concrete-insulated for radiation resistance. F. Streun stands on the right.

  5. Influence of gallium ion beam acceleration voltage on the bend angle of amorphous silicon cantilevers

    Science.gov (United States)

    Kozeki, Takahiro; Phan, Hoang-Phuong; Viet Dao, Dzung; Inoue, Shozo; Namazu, Takahiro

    2016-06-01

    This paper describes a plastic reshaping technique for Si thin membranes by using focused ion beam (FIB) processing. FIB is used to locally pattern and implant Ga ions into the membranes. The combination of Ga ion doping and alkali wet etching enables us to fabricate nanometer-thick Ga-ion-doped amorphous Si membranes, which can be bent upward at arbitrary angle by controlling the FIB beam irradiation condition. The bending mechanism is discussed in the light of Ga ions implanted depth from the membrane surface. By using this technique, a micrometer-sized chute structure with several different angles is produced.

  6. Bending vibration of axially loaded Timoshenko beams with locally distributed Kelvin-Voigt damping

    Science.gov (United States)

    Chen, Wei-Ren

    2011-06-01

    Utilizing the Timoshenko beam theory and applying Hamilton's principle, the bending vibration equations of an axially loaded beam with locally distributed internal damping of the Kelvin-Voigt type are established. The partial differential equations of motion are then discretized into linear second-order ordinary differential equations based on a finite element method. A quadratic eigenvalue problem of a damped system is formed to determine the eigenfrequencies of the damped beams. The effects of the internal damping, sizes and locations of damped segment, axial load and restraint types on the damping and oscillating parts of the damped natural frequency are investigated. It is believed that the present study is valuable for better understanding the influence of various parameters of the damped beam on its vibration characteristics.

  7. Applications of circularly polarized photons at the ALS with a bend magnet source

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High {Tc} Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements.

  8. Applications of circularly polarized photons at the ALS with a bend magnet source

    International Nuclear Information System (INIS)

    The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High Tc Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements

  9. Theoretical Study of Large-Angle Bending Transport of Microparticles by 2D Acoustic Half-Bessel Beams.

    Science.gov (United States)

    Li, Yixiang; Qiu, Chunyin; Xu, Shengjun; Ke, Manzhu; Liu, Zhengyou

    2015-01-01

    Conventional microparticle transports by light or sound are realized along a straight line. Recently, this limit has been overcome in optics as the growing up of the self-accelerating Airy beams, which are featured by many peculiar properties, e.g., bending propagation, diffraction-free and self-healing. However, the bending angles of Airy beams are rather small since they are only paraxial solutions of the two-dimensional (2D) Helmholtz equation. Here we propose a novel micromanipulation by using acoustic Half-Bessel beams, which are strict solutions of the 2D Helmholtz equation. Compared with that achieved by Airy beams, the bending angle of the particle trajectory attained here is much steeper (exceeding 90(o)). The large-angle bending transport of microparticles, which is robust to complex scattering environment, enables a wide range of applications from the colloidal to biological sciences. PMID:26279478

  10. Geometrically nonlinear bending analysis of Metal-Ceramic composite beams under thermomechanical loading

    Science.gov (United States)

    Torabizadeh, Mohammad Amin

    2013-07-01

    A new method is developed to derive equilibrium equations of Metal-Ceramic beams based on first order shear deformation plate theory which is named first order shear deformation beam theory2(FSDBT2). Equilibrium equations obtained from conventional method (FSDBT1) is compared with FSDBT2 and the case of cylindrical bending of Metal-Ceramic composite plates for non-linear thermomechanical deformations and various loadings and boundary conditions. These equations are solved by using three different methods (analytical, perturbation technique and finite element solution). The through-thickness variation of the volume fraction of the ceramic phase in a Metal-Ceramic beam is assumed to be given by a power-law type function. The non-linear strain-displacement relations in the von-Kármán sense are used to study the effect of geometric non-linearity. Also, four other representative averaging estimation methods, the linear rule, Mori-Tanaka, Self-Consistent and Wakashima-Tsukamoto schemes, by comparing with the power-law type function are also investigated. Temperature distribution through the thickness of the beams in thermal loadings is obtained by solving the one-dimensional heat transfer equation. Finally it is concluded that for Metal-Ceramic composites, these two theories result in identical static responses. Also the displacement field and equilibrium equations in the case of cylindrical bending of Metal-Ceramic plates are the same as those supposed in FSDBT2.

  11. Different kinds of analysis methods on a rectangular combined function bending magnet

    International Nuclear Information System (INIS)

    We develop two kinds of Hall probe mapping trajectories with four analysis methods to measure and analyze the bending magnet's field behavior. A sufficient correlation among the four methods is an important feature. Those methods are individually used to derive the pole face tilt and bent, the effective magnetic length and to check the specification establish by the beam dynamics group. As for the two mapping methods, one is called ''Radial Mapping'' whose mapping trajectories in the longitudinal direction (s-axis) follow the different arc lengths of radius ρ±r and the transverse trajectories follow the radial displacement ±r perpendicular to the arc trajectory. The other one is called ''Lamination Mapping'' whose mapping trajectories in the longitudinal direction follow the constant arc length of circle radius ρ and the transverse trajectories follow the transverse axis displacement ±x parallel to the lamination direction. This study also discusses the differences between those two mapping methods. Results obtained from the harmonic field distribution along the longitudinal direction (including the fringing field) and the main components of the integral strength are compared. The subsequent error of the four analysis methods is 0.01% for the dipole strength and 0.3% for the quadrupole strength individually. According to the specifications, those analysis errors are acceptable. Meanwhile, the accuracies of different methods for the higher multipole strengths are all within tolerances. The peculiar sextupole field behavior at the two magnet edges from the different mapping methods is owing to the effective magnet pole face. (orig.)

  12. Direct evidence for terrace bending from He beam scattering on Pt(997)

    International Nuclear Information System (INIS)

    He-nozzle beams were scattered on a stepped Pt(997) surface. Diffraction peaks up to the 6th order are clearly resolved. For incident angles 0, the diffraction patterns are very similar to the patterns obtained by light scattering on echelette gratings. An elementary model based upon this analogy fits the results fairly well. The deviations observed for glancing angles of incidence are interpreted as an evidence for an upward bending of the interaction potential on the terrace in the vicinity of the downward step. (Auth.)

  13. 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.

  14. Control and Interlocking System for Bending Magnet Front-end at Indus-2

    International Nuclear Information System (INIS)

    We present control and interlock system developed for Indus-2 bending magnet front-end. The paper describes in detail the control of various signals associated with the front-end and the interlocking scheme implemented for the installed front-end. The number of signals associated with each front-end is ∼ 75. A control system is designed for monitoring temperature, pressure, airflow, water flow and control of vacuum gauges, fast shutter, water cooled shutter, safety shutter, pneumatic gate valves, sputter ion pump power supplies, beam position monitor etc. Two independent signals are generated for critical components that are used for software interlock and hard-wired interlock. The front-end control system is VME based and window 2000/XP workstation as an operator console. The CPU used is Motorola 68000-processor board of the VME bus having OS-9 real time operating system. One VME crate serves a cluster of 2-3 front ends. The communication between the VME and the workstation is linked over RS232 serial communication. The sputter ion power supplies are connected over isolated RS485 network. Critical protection features are implemented so that no single failure can render the system unsafe. This is implemented by providing two independent chains of protection (1) Hard wired in which relay logic is used and (2) Software. A Graphical User Interface (GUI) is developed using Lab view Version 7.0

  15. The study of magnetic properties, coercivity mechanism and bending strength of hot-deformed RE-Fe-B magnets

    International Nuclear Information System (INIS)

    The effect on mechanical properties and magnetic properties of hot-deformed magnets with different rare earth (RE) content has been investigated. The results show that the optimal comprehensive magnetic properties are obtained at 13.09 at% RE. The bending strength parallel to c-axis orientation increases with the increasing of RE content, while that perpendicular to c-axis orientation exhibits decrease. Moreover, the micro magnetic structure was observed and the coercivity mechanism of the hot-deformed magnet sample was discussed. - Highlights: • The optimal comprehensive magnetic properties are obtained at 13.09 at% RE. • The bending strength with different rare earth content is determined. • Domain wall moved irreversibly when the external field gets close to the coercivity. • Inhomogeneous domain wall pinning should be the dominant coercivity mechanism

  16. Long term bending behavior of ultra-high performance concrete (UHPC beams

    Directory of Open Access Journals (Sweden)

    Gheorghe-Alexandru BARBOS

    2015-12-01

    Full Text Available Unlike normal concrete (NC the behavior of ultra-high performance concrete (UHPC is different under long-term efforts, if we refer to creep, shrinkage or long-term deflections. It is well known that UHPC has special properties, like compressive strength higher than 150 MPa and tensile strength higher than 20 MPa - in case of UHPC reinforced with steel-fibers. Nevertheless, UHPC behavior is not completely elucidated in what concerns creep straining or serviceability behavior in case of structural elements. Some studies made on UHPC samples shown that creep is significantly reduced if the concrete is subjected to heat treatment and if it contains steel-fiber reinforcement. Relating thereto, it is important to know how does structural elements made of this type of concrete works in service life under long-term loadings. The results obtained on UHPC samples, regarding creep straining from tension or compression efforts may not be generalized in case of structural elements (e.g. beams, slabs, columns subjected to bending. By performing this study, it was aimed to understand the influence of heat treatment and steel-fiber addition on the rheological phenomena of UHPC bended beams.

  17. Textile artificial magnetic conductor jacket for transmission enhancement between antennas under bending and wetness measurements

    Science.gov (United States)

    Kamardin, Kamilia; Rahim, Mohamad Kamal A.; Hall, Peter S.; Samsuri, Noor Asmawati; Latef, Tarik Abdul; Ullah, Mohammad Habib

    2016-04-01

    Textile artificial magnetic conductor (AMC) waveguide jacket for transmission enhancement between on-body antennas is proposed. Transmission characteristics between antennas with different orientations and placements are studied. Significant transmission enhancement is observed for all tested positions. Bending and wetness measurements are also conducted. Bending is found not to give significant effect to the antennas and AMC performance, while wetness yields severe performance distortion. However, the original performance is retrieved once the antennas and AMC dried. The proposed AMC jacket will act as a new approach for efficient wearable body-centric communications.

  18. Solar wind magnetic field bending of Jovian dust trajectories.

    Science.gov (United States)

    Zook, H A; Grün, E; Baguhl, M; Hamilton, D P; Linkert, G; Liou, J; Forsyth, R; Phillips, J L

    1996-11-29

    From September 1991 to October 1992, the cosmic dust detector on the Ulysses spacecraft recorded 11 short bursts, or streams, of dust. These dust grains emanated from the jovian system, and their trajectories were strongly affected by solar wind magnetic field forces. Analyses of the on-board measurements of these fields, and of stream approach directions, show that stream-associated dust grain masses are of the order of 10(-18) gram and dust grain velocities exceed 200 kilometers per second. These masses and velocities are, respectively, about 10(3) times less massive and 5 to 10 times faster than earlier reported. PMID:8929405

  19. Modelling the bending/bowing of composite beams such as nuclear fuel: The BOW code

    Energy Technology Data Exchange (ETDEWEB)

    Tayal, M. (Atomic Energy of Canada Ltd., Sheridan Park, Ontario. CANDU Operations)

    1989-09-01

    Arrays of tubes are used in many engineered structures, such as in nuclear fuel bundles and in steam generators. The tubes are bend (bow) due to in-service temperatures and loads. Assessments of bowing of nuclear fuel elements can help demonstrate the integrity of fuel and of surrounding components, as a function of operating conditions such as channel power. The BOW code calculates the bending of composite beams such as fuel elements, due to gradients of temperature and due to hydraulic forces. The deflections and rotations are calculated in both lateral directions, for given conditions of temperatures. Wet and dry operation of the sheath can be simulated. BOW accounts for the following physical phenomena: circumferential and axial variations in the temperatures of the sheath and of the pellet; cracking of pellets; grip and slip between the pellets and the sheath; hydraulic drag; restraints from endplates, from neighbouring elements, and from the pressure-tube; gravity; concentric or eccentric welds between endcaps and endplate; neutron flux gradients; and variations of material properties with temperature. The code is based on fundamental principles of mechanics. The governing equations are solved numerically using the finite element method. Several comparisons with closed-form equations show that the solutions of BOW are accurate. BOW's predictions for initial in-reactor bow are also consistent with two post-irradiation measurements. (orig.).

  20. Effect of web stiffness on the bending behaviour of timber composite I-beams

    International Nuclear Information System (INIS)

    The design of timber I-beams with glued OSB web is currently based on simplified analytical model and experimental works. At the ultimate limit state, normal forces in the flanges and shear stresses in the web govern the load-carrying capacity of the beams. Applications in industrial or commercial buildings requires cross-section with greater height. In this paper, the effect of the slenderness of the web is analysed through an experimental program and a finite element model. For beams with finger-jointed flanges and butt-joints between web panels, the effective stiffness and the bending capacity are evaluated considering a web of 12 mm in thickness and height varying from 225 to 495 mm. The experimental values of the effective stiffness were compared to the theoretical evaluation taking into account the shear deformations of the web. For highest heights of the cross-section, the results shown that the ultimate capacity is governed by the plate behaviour of the web, resulting in the failure of the glued joint. On this basis, the internal behaviour is examined using a three-dimensional finite element modelling. The effect of the mains parameters such as the relative stiffness of the components and the gap between web panels is investigated. The stress concentration in the area of the web joint is analysed and a new design criterion is calibrated

  1. Effect of web stiffness on the bending behaviour of timber composite I-beams

    Energy Technology Data Exchange (ETDEWEB)

    Racher, P. [Civil Engineering Laboratory, CUST, Blaise Pascal University - Campus des Cezeaux, BP 206, 63174 Aubiere Cedex (France)]. E-mail: p.racher@cust.univ-bpclermont.fr; Bocquet, J.F. [LERMAB, ENSTIB, Henri Poincarre University, 88000 Epinal (France); Bouchair, A. [Civil Engineering Laboratory, CUST, Blaise Pascal University - Campus des Cezeaux, BP 206, 63174 Aubiere Cedex (France)

    2007-07-01

    The design of timber I-beams with glued OSB web is currently based on simplified analytical model and experimental works. At the ultimate limit state, normal forces in the flanges and shear stresses in the web govern the load-carrying capacity of the beams. Applications in industrial or commercial buildings requires cross-section with greater height. In this paper, the effect of the slenderness of the web is analysed through an experimental program and a finite element model. For beams with finger-jointed flanges and butt-joints between web panels, the effective stiffness and the bending capacity are evaluated considering a web of 12 mm in thickness and height varying from 225 to 495 mm. The experimental values of the effective stiffness were compared to the theoretical evaluation taking into account the shear deformations of the web. For highest heights of the cross-section, the results shown that the ultimate capacity is governed by the plate behaviour of the web, resulting in the failure of the glued joint. On this basis, the internal behaviour is examined using a three-dimensional finite element modelling. The effect of the mains parameters such as the relative stiffness of the components and the gap between web panels is investigated. The stress concentration in the area of the web joint is analysed and a new design criterion is calibrated.

  2. Beam Transport in Toroidal Magnetic Field

    CERN Document Server

    Joshi, N; Meusel, O; Ratzinger, U

    2016-01-01

    The concept of a storage ring with toroidal magnetic field was presented in the two previous EPAC conferences. Here we report the first results of experiments performed with beam transport in toroidal magnetic fields and details of the injection system. The beam transport experiments were carried out with 30 degree toroidal segments with an axial magnetic field of 0.6T. The multi turn injection system relies on a transverse injection coil together with an electric kicker system.

  3. Modeling of the Bending Stiffness of a Bimaterial Beam by the Approximation of One-Dimensional of Laminated Theory

    Directory of Open Access Journals (Sweden)

    M. Flores-Domínguez

    2014-03-01

    Full Text Available In this paper, a mathematical model representing the bending stiffness of a bimaterial beam is proposed. The classical laminated plate theory specialized to 1D is used for modeling the stiffness bending of a beam. Different material configurations (metal-polymer, metal-composite material and metal-metal with three different ratios of layer thickness were evaluated by the analytical model were proposed. Virtual experiments by finite element analysis were carried out to verify the accuracy of the proposed approach. Finite element models of each arrangement were built and the recommendations for the ASTM three-point bending test were followed in the numerical simulation. The average difference of the stiffness results calculated by the analytical model and by finite element simulation was less than 2.11%.

  4. Magnetic field stimulated enhancement of the barrier for vortex penetration in bended bridges of thin TaN films

    International Nuclear Information System (INIS)

    Highlights: • Critical state in mesoscopic superconducting TaN structures has been studied. • Suppression of the current crowding by magnetic field has been investigated. • Maximum of critical current of bended TaN bridges is at non-zero magnetic field. • The critical current of 90° bended bridges increases by 37% in magnetic field. • Significant bulk pinning is in ultra-thin TaN mesoscopic structures. - Abstract: An increase of the supercurrent density in the vicinity of sharp bends of mesoscopic superconducting strips (the current crowding) leads to a decrease of the potential barrier for vortex penetration and thus to a decrease of the measured critical current IC of the strip in comparison to the de-pairing critical current. However, it has been shown that the Meissner currents induced by an external magnetic field of appropriate direction reduce the effect of current crowding resulting in an increase of the measured IC of superconducting mesoscopic structures with bends. We performed a detailed experimental investigation of the dependence of critical current on magnetic field in straight and bended bridges made from thin TaN films. Indeed, in the case of bridges with bends, the critical current reaches a maximum at non-zero magnetic fields which value increases with an increase of the angle of bends

  5. Variation of dynamic magnetic field on KEK-PS main ring bending electromagnet

    International Nuclear Information System (INIS)

    When measuring a magnetic field of each electromagnet under its acceleration by using back-leg coil of a proton accelerator (PS) main ring bending electromagnet for a sensor, nevertheless total bending electromagnet is connected in series, forming field of each electromagnet was not equal in its details. Here were reported on following three phenomena elucidated on these causes: because of presence of dummy electromagnet and unbalance in capacity of common mode capacitor, two series of electromagnets became asymmetric in load and had a difference in electromagnet magnetic field of both series just after beginning of acceleration due to specific frequency; too late rising-up on magnetic field under acceleration of only two sets of electromagnets of 2-1B' and 3-1B' with different vacuum duct; and, by total renewal of the source and the wiring except gamma(sub T) electromagnet, field induction was reduced but each electromagnet had some differences and only bending electromagnets at both sides of the gamma(sub T) electromagnet suffered interference except one. (G.K.)

  6. Cantilever beam static and dynamic response comparison with mid-point bending for thin MDF composite panels

    Directory of Open Access Journals (Sweden)

    John F. Hunt

    2013-02-01

    Full Text Available A new cantilever beam apparatus has been developed to measure static and vibrational properties of small and thin samples of wood or composite panels. The apparatus applies a known displacement to a cantilever beam, measures its static load, then releases it into its natural first mode of transverse vibration. Free vibrational tip displacements as a function of time were recorded. This paper compares the test results from the cantilever beam static bending and vibration with standard mid-point simply supported bending samples. Medium density fiberboard panels were obtained from four different commercial sources. Comparisons were made using a set of fiberboard panels with thicknesses of 8.1, 4.5, 3.7, and 2.6 mm and nominal densities of 700, 770, 780, and 830 kg/m3, respectively. Cantilever beam static modulus and dynamic modulus of elasticity linearly correlated well but were consistently higher than standard mid-point bending modulus of elasticity having linear correlations of 1.12:1 and 1.26:1, respectively. The higher strain rates of both the static and vibrating cantilever beam could be the primary reason for the slightly higher dynamic modulus values. The log decrement of the displacement was also used to calculate the damping ratio for the cantilever beam. As expected, damping ratio had a slightly decreasing slope as density increased. This paper discusses the new apparatus and initial results.

  7. Prestress Loss and Bending Capacity of Pre-cracked 40 Year-Old PC Beams Exposed to Marine Environment

    Directory of Open Access Journals (Sweden)

    Dasar Amry

    2016-01-01

    Full Text Available Six prestressed concrete beams (PC beam were used for evaluation, consist of four post-tension beams (PC-O and two pre-tension beams (PC-R. In order to investigate the effect of crack on prestress loss and bending capacity after long-term exposed, prestressed concrete beams were pre-crack and then exposed to marine environment. Experimental work was carried out to evaluate PC beams performance after long-term exposed. In addition, visual observations and load bearing capacity test was carried out. Furthermore, evaluation of prestress loss conducted using three-point loading bending test and the remaining tendon forces in the beam were determined using Crack Re-opening Method. The experimental results revealed that prestress loss was increased due to corrosion of strand/wire which affected by the pre-crack on the prestressed beams. Approximately a prestress loss around 26% and 30% was recorded for post-tension and pre-tension beams respectively.

  8. Bending reinforcement of timber beams with steel cross sections on the upper face

    Directory of Open Access Journals (Sweden)

    González-Bravo, Carlos

    2010-06-01

    Full Text Available A procedure for the reinforcement of timber floor joists in ancient buildings using steel U shape cross sections screwed to timber from the upper side is described. Bending tests of 3 groups of 10 beams were carried out obtaining the stiffness and load carrying capacity. The first one was composed by pieces of glued laminated timber of Spruce with 180x200 mm cross section; the second one was of Scots pine sawn timber with the same cross section; and the third one was 120 years old solid timber beams of genus Pine with 130x150 mm cross section. Each group was divided in two groups of 5 beams. The first sub-group was tested without reinforcement and the second one was tested with the steel reinforcement. The reinforcement increases the stiffness from 45 to 98 % and the load carrying capacity from 27 to 58 %.

    Se describe un procedimiento para el refuerzo de viguetas de madera en edificios antiguos utilizando perfiles de acero con sección en U conectados a la madera con tirafondos y situados en la cara superior. Se realizaron ensayos a flexión sobre 3 grupos de 10 piezas obteniendo la rigidez y la capacidad de carga. El primero compuesto por piezas de madera laminada encolada de abeto con una sección de 180x200 mm; el segundo con madera aserrada de pino silvestre; y el tercero con madera del género Pinus con una sección de 130x150 mm, con 120 años de antigüedad. Cada grupo se dividió a su vez en dos grupos de 5 piezas. El primer subgrupo se ensayó sin refuerzo y el segundo con el refuerzo metálico. El refuerzo incrementa la rigidez entre el 45 y el 98 % y la capacidad de carga entre el 27 y el 58 %.

  9. Experimental Study of the Flexural Behaviour of Damaged RC Beams Strengthened in Bending Moment Region with Basalt Fiber Reinforced Polymer (BFRP) Sheets

    OpenAIRE

    Akshay P. Gholkar; H. S. JADHAV

    2014-01-01

    This paper presents the flexural behaviour of basalt fiber reinforced polymer (BFRP) strengthened reinforced concrete (RC) beams. For flexural strengthening of reinforced concrete beams, total twenty-two beams were cast and tested over an effective span of 900 mm up to failure of the beam under two-point loading. The beams were designed as under-reinforced beams. The beams were bonded with BFRP sheets in single layer and double layers in the bending moment region at the bottom...

  10. Polycapillary based {mu}-XAS and confocal {mu}-XANES at a bending magnet source of the ESRF

    Energy Technology Data Exchange (ETDEWEB)

    Silversmit, Geert; Vekemans, Bart; Vincze, Laszlo [X-ray Microspectroscopy and Imaging Research Group (XMI), Department of Analytical Chemistry, Ghent University, Krijgslaan 281 S12, B-9000 Gent (Belgium); Nikitenko, Sergey; Bras, Wim [Netherlands Organisation for Scientific Research (NWO), DUBBLE at ESRF, BP 220, 38043 Grenoble CEDEX 9 (France); Tirez, Kristof [VITO, Boeretang 200, 2400 Mol (Belgium); Brenker, Frank E, E-mail: Geert.Silversmit@UGent.b [Geoscience Institute - Mineralogy, Goethe University, Altenhoeferallee 1, 60438 Frankfurt am Main (Germany)

    2009-11-15

    Glass polycapillary optics are shown to be easy to use focusing optics for bending magnet XAS stations. These achromatic optics have acceptances of several mm horizontally and vertically, while their angular acceptances can be matched to the source divergence by the design of the polycapillary. A polycapillary half-lens based focusing system was successfully tested for transmission and fluorescence {mu}-XAS at the DUBBLE beamline (BM26A, ESRF) and the feasibility of confocal {mu}-XANES in fluorescence mode is presented. Transmission efficiencies of 25-45% with flux density gain factors of about 2000 and beam sizes of 10-20 {mu}m were obtained in the 7-14 keV energy range. Although the polycapillary optic has a smoothly changing energy dependent transmission efficiency, the amplitude and shape of the EXAFS oscillations are not influenced by this. The focusing properties of the polycapillary lens cancel slight vertical motions of the incoming X-ray beam, resulting in a fixed {mu}-beam spot in the focal plane, making polycapillaries also suitable optic in combination with a non-fixed exit monochromator. In addition, by mounting a second polycapillary half-lens in front of an energy dispersive detector, a confocal set-up is obtained, which restricts the part of the sample seen by the detector to a microscopic volume of about 20x20x15 {mu}m{sup 3} at the Fe K absorption edge for example.

  11. Theoretical analysis of the background intensity distribution in X-ray Birefringence Imaging using synchrotron bending-magnet radiation

    Science.gov (United States)

    Sutter, John P.; Dolbnya, Igor P.; Collins, Stephen P.; Harris, Kenneth D. M.; Edwards-Gau, Gregory R.; Palmer, Benjamin A.

    2015-04-01

    In the recently developed technique of X-ray Birefringence Imaging, molecular orientational order in anisotropic materials is studied by exploiting the birefringence of linearly polarized X-rays with energy close to an absorption edge of an element in the material. In the experimental setup, a vertically deflecting high-resolution double-crystal monochromator is used upstream from the sample to select the appropriate photon energy, and a horizontally deflecting X-ray polarization analyzer, consisting of a perfect single crystal with a Bragg reflection at Bragg angle of approximately 45°, is placed downstream from the sample to measure the resulting rotation of the X-ray polarization. However, if the experiment is performed on a synchrotron bending-magnet beamline, then the elliptical polarization of the X-rays out of the electron orbit plane affects the shape of the output beam. Also, because the monochromator introduces a correlation between vertical position and photon energy to the X-ray beam, the polarization analyzer does not select the entire beam, but instead selects a diagonal stripe, the slope of which depends on the Bragg angles of the monochromator and the polarization analyzer. In the present work, the final background intensity distribution is calculated analytically because the phase space sampling methods normally used in ray traces are too inefficient for this setup. X-ray Birefringence Imaging data measured at the Diamond Light Source beamline B16 agree well with the theory developed here.

  12. Energy-spread measurement of triple-pulse electron beams based on the magnetic dispersion principle

    CERN Document Server

    Wang, Yi; Yang, Zhiyong; Zhang, Huang; Ding, Hengsong; Yang, Anmin; Wang, Minhong

    2016-01-01

    The energy-spread of the triple-pulse electron beam generated by the Dragon-II linear induction accelerator is measured using the method of energy dispersion in the magnetic field. A sector magnet is applied for energy analyzing of the electron beam, which has a bending radius of 300 mm and a deflection angle of 90 degrees. For each pulse, both the time-resolved and the integral images of the electron position at the output port of the bending beam line are recorded by a streak camera and a CCD camera, respectively. Experimental results demonstrate an energy-spread of less than +-2.0% for the electron pulses. The cavity voltage waveforms obtained by different detectors are also analyzed for comparison.

  13. Textile Diamond Dipole and Artificial Magnetic Conductor Performance under Bending, Wetness and Specific Absorption Rate Measurements

    Directory of Open Access Journals (Sweden)

    K. Kamardin

    2015-09-01

    Full Text Available Textile diamond dipole and Artificial Magnetic Conductor (AMC have been proposed and tested under wearable and body centric measurements. The proposed antenna and AMC sheet are entirely made of textiles for both the substrate and conducting parts, thus making it suitable for wearable communications. Directive radiation patterns with high gain are obtained with the proposed AMC sheet, hence minimizing the radiation towards the human body. In this study, wearable and body centric measurements are investigated which include bending, wetness and Specific Absorption Rate (SAR. Bending is found not to give significant effect to the antenna and AMC performance, as opposed to wetness that yields severe performance distortion. However, the original performance is retrieved once the antenna and AMC dried. Moreover, notable SAR reduction is achieved with the introduction of the AMC sheet, which is appropriate to reduce the radiation that penetrates into human flesh.

  14. Bending response of terfenol-D/BaTiO3 bilayer to external magnetic and electric fields

    International Nuclear Information System (INIS)

    The interplay of ferroelectrics and ferromagnetics gives an additional freedom for device design. Based on thermodynamic theory, the bending response of a bilayer terfenol-D/BaTiO3 system to external magnetic and electric fields was investigated. The vertical displacement induced by an asymmetry stress in the bilayer system can be controlled by the thicknesses of each layer, external electric field and magnetic field. A high relative static displacement of 55% can be obtained under a saturated magnetic field. The large bending response controlled by external electric and magnetic fields simultaneously may have potential applications for multifunctional devices.

  15. Bending response of terfenol-D/BaTiO{sub 3} bilayer to external magnetic and electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiaoyan [School of Astronautics, Harbin Institute of Technology, Harbin (China); Wang Biao [School of Physics and Engineering, Sun Yat-sen University, Guangzhou (China); Zheng Yue [Department of Electronic and Information Engineering, The Hong Kong Polytechnic University (Hong Kong); Ju Yanzhong, E-mail: luxyhit@gmail.co [Department of Civil Engineering, Northeast Dianli University, Jilin (China)

    2009-04-07

    The interplay of ferroelectrics and ferromagnetics gives an additional freedom for device design. Based on thermodynamic theory, the bending response of a bilayer terfenol-D/BaTiO{sub 3} system to external magnetic and electric fields was investigated. The vertical displacement induced by an asymmetry stress in the bilayer system can be controlled by the thicknesses of each layer, external electric field and magnetic field. A high relative static displacement of 55% can be obtained under a saturated magnetic field. The large bending response controlled by external electric and magnetic fields simultaneously may have potential applications for multifunctional devices.

  16. Role of elastic bending stress on magnetism of a manganite thin film studied by polarized neutron reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S. [Los Alamos National Laboratory (LANL); Fitzsimmons, M. R. [Los Alamos National Laboratory (LANL); Lookman, T [Los Alamos National Laboratory (LANL); Jeen, Hyoung Jeen [ORNL; Biswas, A [University of Florida, Gainesville; Roldan Gutierrez, Manuel A [ORNL; Varela del Arco, Maria [ORNL

    2012-01-01

    We measured the magnetization depth profile of a (La{sub 1-x}Pr{sub x}){sub 1-y}Ca{sub y}MnO{sub 3} (x = 0.60 {+-} 0.04, y = 0.20 {+-} 0.03) film using polarized neutron reflectometry as a function of applied elastic bending stress and temperature. We found unequivocal and until now elusive direct evidence that the exclusive application of compressive or tensile bending stress along the magnetic easy axis increases or decreases, respectively, the saturation magnetization of the film. Furthermore, we obtained a coupling coefficient relating strain to the depth-dependent saturation magnetization.

  17. Operational studies and expected performance of superconducting quadrupole magnets in the first stages of secondary beams

    International Nuclear Information System (INIS)

    A low current, large bore, epoxy impregnated superconducting quadrupole magnet was constructed at Argonne National Laboratory as a possible prototype for secondary beam use. The quadrupole magnet was placed in the Fermilab P-West High Intensity Area beam for beam quenching tests. Tests were performed by targetting a primary proton beam directly onto the quadrupole coil and by using the quadrupole in its anticipated role as part of the first stage flux collection triplet for a zero degree anti-proton secondary beam formed from the decays of neutral Lambda particles. Comparing the results with similar tests performed using forced flow Energy Saver dipoles shows that the epoxy impregnated quadrupoles have a much greater sensitivity to beam induced quenching at a similar fraction of the conductor short sample limit. Using the CASIM program, calculations indicate that such eopxy impregnated coils would not be viable as first stage flux collection elements without appreciable collimation and subsequent loss of secondary beam acceptance. Quadrupoles based on Energy Saver technology appear capable of tolerating acceptable primary beam intensities. The momentum dispersing bends will require even larger aperture superconducting dipoles or neutral beam dump within the bend string

  18. An experimental study of the strength of composite-reinforced beams and bars in transverse bending and axial compression

    Energy Technology Data Exchange (ETDEWEB)

    Dzhankhotov, S.O.; Panfilov, B.V.; Spichkova, L.E.

    1989-01-01

    Experimental data are presented on the strength and fracture characteristics of composite-reinforced beams and short and long bars of aluminum alloys in transverse bending and axial compression. The reinforcement materials include carbon and boron composites with a polymer matrix as well as boron/aluminum. The results demonstrate the effectiveness of using structures reinforced by unidirectional composites. In aerospace applications, the use of composite reinforcements can significantly reduce the weight of structures. 6 refs.

  19. STRESS DISTRIBUTIONS AND STRESS CONCENTRATION FACTORS IN A SIMPLE BEAM WITH A CIRCULAR HOLE SUBJECTED TO CONSTANT BENDING MOMENT

    Directory of Open Access Journals (Sweden)

    Seçil ERİM

    1998-03-01

    Full Text Available In this study, a beam subjected to pure bending with a circular hole on its transverse axis, is analyzed by the Finite Element Method. The hole is shifted to various locations along the transverse axis and two different materials, namely isotropic (steel and orthotropic (graphite-epoxy, are used as beam material. Stress distribution and stress concentration factors around the hole are determined for each case. In order to establish the effect of fiber reinforcing angle on the stress distribution, the examination is repeated at various reinforcing angles between 0° and 90° for graphite-epoxy. Denoting the distance between the longitudinal axis and the center of the hole as b, the value of the critical hole diameter which leads to the maximum theoretical bending moment is determined by using the Finite Element Method. Furthermore, the critical distance b which will create the maximum theoretical bending moment for a constant hole diameter of 10 mm, is calculated for steel and each reinforcing angle of the composite beam.

  20. Beamline 9.3.2 - a high-resolution, bend-magnet beamline with circular polarization capability

    Energy Technology Data Exchange (ETDEWEB)

    Moler, E.J.; Hussain, Z.; Howells, M.R. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Beamline 9.3.2 is a high resolution, SGM beamline on an ALS bending magnet with access to photon energies from 30-1500 eV. Features include circular polarization capability, a rotating chamber platform that allows switching between experiments without breaking vacuum, an active feedback system that keeps the beam centered on the entrance slit of the monochromator, and a bendable refocusing mirror. The beamline optics consist of horizontally and vertically focussing mirrors, a Spherical Grating Monochromator (SGM) with movable entrance and exit slits, and a bendable refocussing mirror. In addition, a movable aperature has been installed just upstream of the vertically focussing mirror which can select the x-rays above or below the plane of the synchrotron storage ring, allowing the user to select circularly or linearly polarized light. Circularly polarized x-rays are used to study the magnetic properties of materials. Beamline 9.3.2 can supply left and right circularly polarized x-rays by a computer controlled aperture which may be placed above or below the plane of the synchrotron storage ring. The degree of linear and circular polarization has been measured and calibrated.

  1. Upgrade of the CERN Proton Synchrotron Booster bending magnets for 2 GeV Operation

    CERN Document Server

    Newborough, A; Chritin, R

    2013-01-01

    Since its first operation in 1972 at an energy of 800MeV the CERN Proton Synchrotron Booster, which consists of 4 super imposed synchrotrons, has seen two upgrades: once to 1.0 GeV in 1988 and then to 1.4 GeV in 1999. During this time the main magnets of the machine have remained largely unchanged with small differences (<1%) between the inner and outer gaps of the main bending magnet fields being compensated by trim power supplies. The future upgrade of the machine will demand to extract protons at an energy of 2.0 GeV and require almost double the original dipole field. At this field, due to saturation effects, the inner and outer gaps of the main dipole magnets will differ by up to 4%. This paper presents the design and implementation of a modification of the magnetic circuit strongly reducing these effects. We also discuss the results of experimental tests concerning the effects on field quality and eddy current transients, including the implications for the real-time magnetic field measurement system ...

  2. About contact problem of bending of a beam of finite length on an elastic half-plane in view of forces in its mid-line

    Directory of Open Access Journals (Sweden)

    Amirbekyan A.N.

    2014-03-01

    Full Text Available The contact problem of the bending of the beam of finite length on elastic foundation in the form of a half-plane being in the plane strain conditions, the generalized model of the bend in the framework of S.P. Timoshenko, where in addition to vertical forces axial axial compressive or tensile forces also affect the deflection of the beam is considered.

  3. Demonstration of no feasibility of a crystalline beam in a Betatron Magnet II

    International Nuclear Information System (INIS)

    This paper investigates the feasibility of a Crystalline Beam in a weak-focusing Betatron Magnet. The curvature effect due to the bending magnet is also investigated. The case of circular one- dimensional string of electrically-charged particles is examined. It is found that the motion is unstable due to the dependence of the precession movement with the radial displacement. That is a form of negative-mass instability which can be avoided with an alternating-focussing structure. The calculation of the particle-particle interaction as well as of the forces due to the external magnetic field is done directly in the laboratory frame

  4. Magnetic fields for transporting charged beams

    International Nuclear Information System (INIS)

    The transport of charged particle beams requires magnetic fields that must be shaped correctly and very accurately. During the last 20 years or so, many studies have been made, both analytically and through the use of computer programs, of various magnetic shapes that have proved to be useful. Many of the results for magnetic field shapes can be applied equally well to electric field shapes. A report is given which gathers together the results that have more general significance and would be useful in designing a configuration to produce a desired magnetic field shape. The field shapes studied include the fields in dipoles, quadrupoles, sextupoles, octupoles, septum magnets, combined-function magnets, and electrostatic septums. Where possible, empirical formulas are proposed, based on computer and analytical studies and on magnetic field measurements. These empirical formulas are often easier to use than analytical formulas and often include effects that are difficult to compute analytically. In addition, results given in the form of tables and graphs serve as illustrative examples. The field shapes studied include uniform fields produced by window-frame magnets, C-magnets, H-magnets, and cosine magnets; linear fields produced by various types of quadrupoles; quadratic and cubic fields produced by sextupoles and octupoles; combinations of uniform and linear fields; and septum fields with sharp boundaries

  5. Theoretical analysis on bending behavior of function-ally graded composite beam crack-controlled by ultrahigh toughness cementitious composites

    Institute of Scientific and Technical Information of China (English)

    XU ShiLang; LI QingHua

    2009-01-01

    Ultrahigh toughness cementitious composites (UHTCC) obviously show strain hardening property under tensile or bending loading. The failure pattern of the UHTCC components exhibits multiple fine cracks under uniaxial tensile loading with prominent tensile strain capacity in excess of 3%, with merely 60 μm average crack width even corresponding to the ultimate tensile strain state. The approach adopted is based on the concept of functionally-graded concrete, where part of the concrete, which surrounds the main longitudinal reinforcement in a RC (reinforced concrete) member, is strategically replaced with UHTCC with excellent crack-controlling ability. Investigations on bending behavior of functionally-graded composite beam crack controlled by UHTCC has been carried out, including theo-retical analysis, experimental research on long composite beams without web reinforcement, validation and comparison between experimental and theoretical results, and analysis on crack control. In addi-tion to improving bearing capacity, the results indicate that functionally-graded composite beams using UHTCC has been found to be very effective in preventing corrosion-induced damage compared with RC beams. Therefore, durability and service life of the structure could be enhanced. This paper discusses the development of internal force and crack propagation during loading process, and presents analysis of the internal force in different stages, moment-curvature relationship from loading to damage and calculation of mid-span deflection and ductility index. In the end, the theoretical formulae have been validated by experimental results.

  6. Theoretical analysis on bending behavior of functionally graded composite beam crack-controlled by ultrahigh toughness cementitious composites

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Ultrahigh toughness cementitious composites (UHTCC) obviously show strain hardening property under tensile or bending loading. The failure pattern of the UHTCC components exhibits multiple fine cracks under uniaxial tensile loading with prominent tensile strain capacity in excess of 3%, with merely 60 μm average crack width even corresponding to the ultimate tensile strain state. The approach adopted is based on the concept of functionally-graded concrete, where part of the concrete, which surrounds the main longitudinal reinforcement in a RC (reinforced concrete) member, is strategically replaced with UHTCC with excellent crack-controlling ability. Investigations on bending behavior of functionally-graded composite beam crack controlled by UHTCC has been carried out, including theo- retical analysis, experimental research on long composite beams without web reinforcement, validation and comparison between experimental and theoretical results, and analysis on crack control. In addition to improving bearing capacity, the results indicate that functionally-graded composite beams using UHTCC has been found to be very effective in preventing corrosion-induced damage compared with RC beams. Therefore, durability and service life of the structure could be enhanced. This paper discusses the development of internal force and crack propagation during loading process, and presents analysis of the internal force in different stages, moment-curvature relationship from loading to damage and calculation of mid-span deflection and ductility index. In the end, the theoretical formulae have been validated by experimental results.

  7. Bend strain tolerances of a Nb3Sn conductor proposed for use in the magnetic fusion energy program

    International Nuclear Information System (INIS)

    Bend strain tolerances were studied on a 2869 filament bronze-processed Nb3Sn wire conductor in magnetic fields to 8 T. Relative values of the wire's current transfer length to twist pitch were shown to influence the bend-strain tolerance. Low matrix resistivities, associated with Sn-depleted bronzes following heat-treatments of 48 h at 7250C, produce current transfer lengths less than the twist pitch, 10 mm. The resulting bend-strain tolerances, at 10-12 ohm.cm, are improved over those found for shorter heat-treatment times. Results from bend-fatigue experiments were divided into two domains separated by the strain value required to produce compound cracking, epsilon/sub f//sup B/. Applied bending strains less than epsilon/sub f//sup B/ were found to increase zero strain critical current values and this increase was independent of the number of fatigue cycles. When applying strains large enough to produce cracking in the compounds critical currents decreased from their asreacted values tending to reach a minimum after several fatigue cycles. Evidence exists for a neutral axis shift during bending and slight differences between tensile and bend strain tolerances are accounted for in terms of such a shift

  8. Bending strain-tunable magnetic anisotropy in Co2FeAl Heusler thin film on Kapton

    OpenAIRE

    M. Gueye; Wague, B. M.; ZIGHEM, F; Belmeguenai, M.; Gabor, M. S.; Petrisor jr, T.; Tiusan, C.; Mercon, S.; Faurie, D

    2014-01-01

    Bending effect on the magnetic anisotropy in 20 nm Co$_{2}$FeAl Heusler thin film grown on Kapton\\textregistered{} has been studied by ferromagnetic resonance and glued on curved sample carrier with various radii. The results reported in this letter show that the magnetic anisotropy is drastically changed in this system by bending the thin films. This effect is attributed to the interfacial strain transmission from the substrate to the film and to the magnetoelastic behavior of the Co$_{2}$Fe...

  9. Beam dynamics in magnetic quadrupole triplets

    International Nuclear Information System (INIS)

    The Frankfurt Neutron source at the Stern-Gerlach-Zentrum (FRANZ) will produce high intensity neutron pulses in the energy range of 1 to 500 keV at a very short repetition rate. The neutrons are gained from 7Li(p,n)7Be reactions induced by 2 MeV protons and will be used to examine the nucleosynthesis during the s-process as it occurs in stars, cross sections of neutron capture reactions as well as the behaviour of non-neutral plasmas. In the linear accelerator section, consisting of a 4-rod-radio-frequency-quadrupole and a H-type drift tube linac, the proton pulses are accelerated to 2.03 MeV. Inside the drift tube cavity a magnetic quadrupole triplet will be integrated, in order to compensate transversally defocussing effects and therefore avoid losses. Behind the linear accelerator section the proton beam ist rebunched in a 5-cell CH-rebuncher which is framed by two more quadrupole triplets. To investigate the beam dynamics inside the magnetic quadrupole triplets, various magnetostatic and particle tracking codes like CST Studio and LORASR were used to simulate the beam transport properties of the magnets and compare the individual magnetic field distributions with the ones measured at the magnet laboratory at GSI. In doing so, important aspects to be considered are the longitudinal and transversal fringe fields and the saturation effects which all possibly cause emittance growth and geometrical aberrations.

  10. Beam dynamics in magnetic quadrupole triplets

    Energy Technology Data Exchange (ETDEWEB)

    Claessens, Christine; Heilmann, Manuel; Meusel, Oliver; Podlech, Holger; Ratzinger, Ulrich; Wiesner, Christoph [IAP, Frankfurt University, Frankfurt am Main (Germany)

    2013-07-01

    The Frankfurt Neutron source at the Stern-Gerlach-Zentrum (FRANZ) will produce high intensity neutron pulses in the energy range of 1 to 500 keV at a very short repetition rate. The neutrons are gained from {sup 7}Li(p,n){sup 7}Be reactions induced by 2 MeV protons and will be used to examine the nucleosynthesis during the s-process as it occurs in stars, cross sections of neutron capture reactions as well as the behaviour of non-neutral plasmas. In the linear accelerator section, consisting of a 4-rod-radio-frequency-quadrupole and a H-type drift tube linac, the proton pulses are accelerated to 2.03 MeV. Inside the drift tube cavity a magnetic quadrupole triplet will be integrated, in order to compensate transversally defocussing effects and therefore avoid losses. Behind the linear accelerator section the proton beam ist rebunched in a 5-cell CH-rebuncher which is framed by two more quadrupole triplets. To investigate the beam dynamics inside the magnetic quadrupole triplets, various magnetostatic and particle tracking codes like CST Studio and LORASR were used to simulate the beam transport properties of the magnets and compare the individual magnetic field distributions with the ones measured at the magnet laboratory at GSI. In doing so, important aspects to be considered are the longitudinal and transversal fringe fields and the saturation effects which all possibly cause emittance growth and geometrical aberrations.

  11. Experimental Study of the Flexural Behaviour of Damaged RC Beams Strengthened in Bending Moment Region with Basalt Fiber Reinforced Polymer (BFRP Sheets

    Directory of Open Access Journals (Sweden)

    Akshay P. Gholkar

    2014-07-01

    Full Text Available This paper presents the flexural behaviour of basalt fiber reinforced polymer (BFRP strengthened reinforced concrete (RC beams. For flexural strengthening of reinforced concrete beams, total twenty-two beams were cast and tested over an effective span of 900 mm up to failure of the beam under two-point loading. The beams were designed as under-reinforced beams. The beams were bonded with BFRP sheets in single layer and double layers in the bending moment region at the bottom face of the beam. Out of the twenty-two beams two beams were control beams and remaining beams were strengthened after being damaged for various degrees of damage (0 %, 70 %, 80 %, 90% and 100 %. The experimental results show that the beams strengthened show high load carrying capacity.

  12. Bending of Layer-by-Layer Films Driven by an External Magnetic Field

    Directory of Open Access Journals (Sweden)

    Osvaldo N. Oliveira Jr.

    2013-06-01

    Full Text Available We report on optimized architectures containing layer-by-layer (LbL films of natural rubber latex (NRL, carboxymethyl-chitosan (CMC and magnetite (Fe3O4 nanoparticles (MNPs deposited on flexible substrates, which could be easily bent by an external magnetic field. The mechanical response depended on the number of deposited layers and was explained semi-quantitatively with a fully atomistic model, where the LbL film was represented as superposing layers of hexagonal graphene-like atomic arrangements deposited on a stiffer substrate. The bending with no direct current or voltage being applied to a supramolecular structure containing biocompatible and antimicrobial materials represents a proof-of-principle experiment that is promising for tissue engineering applications in biomedicine.

  13. The coil of the MBI bending magnets for the LHC injection transfer lines

    CERN Document Server

    Labutsky, S A; Pupkov, Yu A; Rouvinsky, E; Sukhina, B

    2002-01-01

    All MBI bending magnets in each of the two LHC injection transfer lines will be powered in series. The limited output voltage of existing power converters lead to an unusual coil design avoiding external return bus-bars by combining two overlapping half-coils, electrically separated, with 3 1/2 turns each in a monolithic structure. The voltage between turns in one coil can reach up-to 3.6 kV. The coil has been designed with particular care for obtaining high interturn and ground insulation. Flux-free soldering of connections with plug-in cone sleeves is applied, allowing to execute water cooled current connections as prolongation of the coil conductor. Epoxy compound polymerization in the impregnation mould is obtained by passing overheated water in regulated cycles through the water circuit of the coil conductor. We describe the design basics as well as various test results of pre-series and series produced coils. (4 refs).

  14. Analysis of pipe mitred bends using beam models - by finite element method

    International Nuclear Information System (INIS)

    The formulation of a recently proposed displacement based straight pipe element for the analysis of pipe mitred bends is summarized in this work. The element kinematics includes axial, bending, torsional and ovalisation displacements, all varying cubically along the axis of the element. Interaction effects between angle adjoined straight pipe section are modeled including the appropriate additional strain terms in the stiffness matrix formulation and by using a penalty procedure to enforce continuity of pipe skin flexural rotations at the common helical edge. The element model capabilities are ilustrated in some sample analysis and the results are compared with other available experimental, analytical or more complex numerical models. (Author)

  15. Extended high order sandwich panel theory for bending analysis of sandwich beams with carbon nanotube reinforced face sheets

    Science.gov (United States)

    Jedari Salami, S.

    2016-02-01

    Bending analysis of a sandwich beam with soft core and carbon nanotube reinforced composite (CNTRC) face sheets in the literature is presented based on Extended High order Sandwich Panel Theory (EHSAPT). Distribution of fibers through the thickness of the face sheets could be uniform or functionally graded (FG). In this theory the face sheets follow the first order shear deformation theory (FSDT). Besides, the two dimensional elasticity is used for the core. The field equations are derived via the Ritz based solution which is suitable for any essential boundary condition. The influences of boundary conditions on bending response of the sandwich panel with soft core and CNTRC face sheet are investigated. In each type of boundary condition the effect of distribution pattern of CNTRCs on many essential involved parameters of the sandwich beam with functionally graded carbon nanotube reinforced composite (FG- CNTRC) face sheets are studied in detail. Finally, experimental result have been compared with those obtained based on developed solution method. It is concluded that, the sandwich beam with X distribution figure of face sheets is the strongest with the smallest transverse displacement, and followed by the UD, O and ∧-ones, respectively.

  16. A beamline for high-pressure studies at the Advanced Light Source with a superconducting bending magnet as the source.

    Science.gov (United States)

    Kunz, Martin; MacDowell, Alastair A; Caldwell, Wendel A; Cambie, Daniella; Celestre, Richard S; Domning, Edward E; Duarte, Robert M; Gleason, Arianna E; Glossinger, James M; Kelez, Nicholas; Plate, David W; Yu, Tony; Zaug, Joeseph M; Padmore, Howard A; Jeanloz, Raymond; Alivisatos, A Paul; Clark, Simon M

    2005-09-01

    A new facility for high-pressure diffraction and spectroscopy using diamond anvil high-pressure cells has been built at the Advanced Light Source on beamline 12.2.2. This beamline benefits from the hard X-radiation generated by a 6 T superconducting bending magnet (superbend). Useful X-ray flux is available between 5 keV and 35 keV. The radiation is transferred from the superbend to the experimental enclosure by the brightness-preserving optics of the beamline. These optics are comprised of a plane parabola collimating mirror, followed by a Kohzu monochromator vessel with Si(111) crystals (E/DeltaE approximately equal 7000) and W/B4C multilayers (E/DeltaE approximately equal 100), and then a toroidal focusing mirror with variable focusing distance. The experimental enclosure contains an automated beam-positioning system, a set of slits, ion chambers, the sample positioning goniometry and area detector (CCD or image-plate detector). Future developments aim at the installation of a second endstation dedicated to in situ laser heating and a dedicated high-pressure single-crystal station, applying both monochromatic and polychromatic techniques. PMID:16120990

  17. A BEAMLINE FOR HIGH PRESSURE STUDIES AT THE ADVANCED LIGHT SOURCE WITH A SUPERCONDUCTING BENDING MAGNET AS THE SOURCE

    International Nuclear Information System (INIS)

    A new facility for high-pressure diffraction and spectroscopy using diamond anvil high-pressure cells has been built at the Advanced Light Source on Beamline 12.2.2. This beamline benefits from the hard X-radiation generated by a 6 Tesla superconducting bending magnet (superbend). Useful x-ray flux is available between 5 keV and 35 keV. The radiation is transferred from the superbend to the experimental enclosure by the brightness preserving optics of the beamline. These optics are comprised of: a plane parabola collimating mirror (M1), followed by a Kohzu monochromator vessel with a Si(111) crystals (E/ΔE ∼ 7000) and a W/B4C multilayer (E/ΔE ∼ 100), and then a toroidal focusing mirror (M2) with variable focusing distance. The experimental enclosure contains an automated beam positioning system, a set of slits, ion chambers, the sample positioning goniometry and area detectors (CCD or image-plate detector). Future developments aim at the installation of a second end station dedicated for in situ laser-heating on one hand and a dedicated high-pressure single-crystal station, applying both monochromatic as well as polychromatic techniques

  18. Photoinduced Magnetic Nanoprobe Excited by Azimuthally Polarized Vector Beam

    CERN Document Server

    Guclu, Caner; Capolino, Filippo

    2016-01-01

    The concept of magnetic nanoprobes (or magnetic nanoantennas) providing a magnetic near-field enhancement and vanishing electric field is presented and investigated, together with their excitation. It is established that a particular type of cylindrical vector beams called azimuthally electric polarized vector beams yield strong longitudinal magnetic field on the beam axis where the electric field is ideally null. These beams with an electric polarization vortex and cylindrical symmetry are important in generating high magnetic to electric field contrast, i.e., large local field admittance, and in allowing selective excitation of magnetic transitions in matter located on the beam axis. We demonstrate that azimuthally polarized vector beam excitation of a photoinduced magnetic nanoprobe made of a magnetically polarizable nano cluster leads to enhanced magnetic near field with resolution beyond diffraction limit. We introduce two figures of merit as magnetic field enhancement and local field admittance normaliz...

  19. The effects of relative density of metal foams on the stresses and deformation of beam under bending

    Institute of Scientific and Technical Information of China (English)

    Aiyu Zhu; Tianyou Fan

    2007-01-01

    The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative den-sity of the material on stresses and deformation are revea-led with the Triantafillou and Gibson constitutive law (TG model) taken as the analysis basis. Several examples for indi-vidual foams are discussed, showing the importance of com-pressibility of the cellular materials. One of the objects of this study is to generalize Hill's solution for incompressible plas-ticity to the case of compressible plasticity, and a kinematics parameter is brought into the analysis so that the velocity field can be determined.

  20. Monochromatic short pulse laser produced ion beam using a compact passive magnetic device

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S. N.; Gauthier, M.; Higginson, D. P.; Dorard, S.; Marquès, J.-R.; Fuchs, J. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Mangia, F.; Atzeni, S. [Dipartimento SBAI, Università di Roma “La Sapienza,” Roma (Italy); Riquier, R. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); CEA, DAM, DIF, F-91297 Arpajon (France)

    2014-04-15

    High-intensity laser accelerated protons and ions are emerging sources with complementary characteristics to those of conventional sources, namely high charge, high current, and short bunch duration, and therefore can be useful for dedicated applications. However, these beams exhibit a broadband energy spectrum when, for some experiments, monoenergetic beams are required. We present here an adaptation of conventional chicane devices in a compact form (10 cm × 20 cm) which enables selection of a specific energy interval from the broadband spectrum. This is achieved by employing magnetic fields to bend the trajectory of the laser produced proton beam through two slits in order to select the minimum and maximum beam energy. The device enables a production of a high current, short duration source with a reproducible output spectrum from short pulse laser produced charged particle beams.

  1. Experimental thermo-stress analysis for a bending shape control of composite beams embedded with SMA wires

    Science.gov (United States)

    Zhou, Gang; Lloyd, Peter

    2009-07-01

    An experimental study has been conducted to design and fabricate smart composite beams embedded with prestrained nitinol wire actuators. The fabrication process developed allowed both quasi-isotropic E-glass/epoxy and carbon/epoxy hosts to be eccentrically embedded with 10 parallel prestrained wires with a purpose-made alignment device and cured successfully in an autoclave. Smart composite beams of three different lengths were made for each type of host. Both single-cycle and multi-cycle thermomechanical bending actuations of these beams in the cantilever set-up were characterised experimentally by applying various levels of electric current to the nitinol wires. The performance characteristics showed that the present fabrication process was repeatable and reliable. While the end deflections of up to 41 mm were easily achieved from smart E-glass/epoxy beams, the limited end deflections were observed from the smart carbon/epoxy beams due primarily to our inability to insulate the nitinol wires. Moreover, it seemed necessary to overheat the prestrained wires to much higher temperatures beyond the complete reverse transformation in order to generate recovery stress.

  2. Coupled bending-torsion steady-state response of pretwisted, nonuniform rotating beams using a transfer-matrix method

    Science.gov (United States)

    Gray, Carl E., Jr.

    1988-01-01

    Using the Newtonian method, the equations of motion are developed for the coupled bending-torsion steady-state response of beams rotating at constant angular velocity in a fixed plane. The resulting equations are valid to first order strain-displacement relationships for a long beam with all other nonlinear terms retained. In addition, the equations are valid for beams with the mass centroidal axis offset (eccentric) from the elastic axis, nonuniform mass and section properties, and variable twist. The solution of these coupled, nonlinear, nonhomogeneous, differential equations is obtained by modifying a Hunter linear second-order transfer-matrix solution procedure to solve the nonlinear differential equations and programming the solution for a desk-top personal computer. The modified transfer-matrix method was verified by comparing the solution for a rotating beam with a geometric, nonlinear, finite-element computer code solution; and for a simple rotating beam problem, the modified method demonstrated a significant advantage over the finite-element solution in accuracy, ease of solution, and actual computer processing time required to effect a solution.

  3. Study of the crystallization kinetics of LAS glass by differential scanning calorimetry, X-ray diffraction, and beam bending viscometry

    International Nuclear Information System (INIS)

    Highlights: ► The crystallization of LAS glass was investigated using XRD, DSC and beam bending viscometry. ► Different models were used to determine the kinetic parameters for crystallization. ► The activation energy and Avrami parameters obtained are consistent with reported values. ► The crystallization of LAS glass occurs with three-dimensional crystals growth. - Abstract: The crystallization kinetics of a commercial lithium-aluminum silicate (LAS) glass were characterized by differential scanning calorimetry (DSC) under non-isothermal conditions, by in-situ X-ray diffraction, and by three point beam bending viscosimeter (BBV). Non-isothermal DSC experiments were conducted at different heating rates. Results show that the crystal growth is controlled by a thermally activated process of the Arrhenius type. The activation energies obtained from isoconversional analysis are close to that extracted using the Johnson–Mehl–Avrami equation. While X-ray diffraction volume fraction data confirm the DSC analysis, it also shows that the crystallite size changes only at the end of the heat treatment protocol, during a hold at temperatures as high as 1000 °C. In this latter case, the crystal growth follows the Ostwald ripening mechanism. Finally, the viscosity measured in the crystallization region by BBV provides the activation energy for viscous flow, and it is slightly higher than the values obtained by DSC.

  4. Test temperature dependence of bending strength of CFRP irradiated with electron beam

    International Nuclear Information System (INIS)

    Carbon fiber-reinforced plastics have the small specific gravity and high specific strength and specific modulus of elasticity as compared with metals, therefore, they are indispensable as the structural materials for aviation and space parts. However, the structural materials for space use are exposed to the environment of several tens MGy of radiation and the repetition of high temperature and low temperature, accordingly also the radiation resistance and heat resistance are required. In this study, the test temperature dependence of the bending strength of CFRP and the relation of the cause of strength lowering to the thickness of CFRP were examined, and the results are reported. As for the carbon fibers for reinforcement, the plain woven cloth of Treca T300 was used, and the matrix resin was tetraglycidyl-4,4'-diamino diphenyl methane being hardened with diamino diphenyl sulfon. The laminated sheets of 2 mm, 0.9 mm and 0.3 mm thickness of the CFRP were used. Irradiation was carried out with an electron accelerator at dose rate of 5 kGy/sec until the prescribed absorbed dose has been attained. The bending test was carried out by three-point bending in the range from room temperature to 180 degC. The high temperature mechanical properties of the irradiated CFRP were superior to those of the CFRP without irradiation. The high temperature mechanical properties depended on aging time at the temperature exceeding the strength inflection point. (K.I.)

  5. Experimental and Analytical Study of Bending Stresses and Deflections in Curved Beam Made of Laminated Composite Material

    Directory of Open Access Journals (Sweden)

    Assma Hassan Ismail

    2014-12-01

    Full Text Available Theoretical and experimental methodologies were assessed to test curved beam made of layered composite material. The maximum stress and maximum deflection were computed for each layer and the effect of radius of curvature and curve shape on them. Because of the increase of the use of composite materials in aircraft structures and the renewed interest in these types of problems, the presented theoretical assessment was made using three different approaches: curved beam theory and an approximate 2D strength of material equations and finite element method (FEM analysis by ANSYS 14.5 program for twelve cases of multi-layered cylindrical shell panel differs in fiber orientations and number of layers. One case of E-glass composite material was experimentally made and tested to verify the relation between applied load and maximum deflection and four models were made of poly carbonyl to determine stresses under bending loads in polar scope, all results were compared with each other, the percentage accuracy was very good. The curved beam theory and strength of material equation formulas results were reasonable for the bottom surface, while it seems not enough for the top surfaces. Also, results explained positions and cases more affected by delaminating and the most preferred part of ellipse shape beam in resisting loads.

  6. Tests of a 3 meter curved superconducting beam transport dipole magnet

    International Nuclear Information System (INIS)

    Initial tests of one of the curved 3 m long superconducting dipole magnets intended to generate 6.0 T and produce a 20.40 bend in the primary proton beam to a new D-target station at the Brookhaven National Laboratory AGS have been completed. Although this magnet, whose window frame design generally follows that of the successful 80 and Model T superconducting dipoles, demonstrates many of the desirable characteristics of these earlier magnets such as excellent quench propagation and good ramping properties, it has only reached a disappointingly low magnetic field of 3.5 to 4.0 T. Because of the great interest in superconducting magnet technology, this report will describe the diagnostic tests performed and plans for future modifications

  7. Tests of a 3 meter curved superconducting beam transport dipole magnet

    Energy Technology Data Exchange (ETDEWEB)

    Allinger, J E; Carroll, A S; Danby, G T; DeVito, B; Jackson, J W; Leonhardt, W J; Prodell, A G; Weisenbloom, J

    1981-01-01

    Initial tests of one of the curved 3 m long superconducting dipole magnets intended to generate 6.0 T and produce a 20.4/sup 0/ bend in the primary proton beam to a new D-target station at the Brookhaven National Laboratory AGS have been completed. Although this magnet, whose window frame design generally follows that of the successful 8/sup 0/ and Model T superconducting dipoles, demonstrates many of the desirable characteristics of these earlier magnets such as excellent quench propagation and good ramping properties, it has only reached a disappointingly low magnetic field of 3.5 to 4.0 T. Because of the great interest in superconducting magnet technology, this report will describe the diagnostic tests performed and plans for future modifications.

  8. Duration of load behaviour of different sized straight timber beams subjected to bending in variable climate

    DEFF Research Database (Denmark)

    Hanhijärvi, A.; Galimard, P.; Hoffmeyer, Preben

    1998-01-01

    The paper is the second in a series which sums up the results of an extensive project to quantify the duration-of-load (DOL) effect on different sized timber beams in different climates. The paper deals with straight (unnotched) beams. The results of various DOL-tests of stepwise and constant ben...

  9. Hybrid neural network model for the design of beam subjected to bending and shear

    Indian Academy of Sciences (India)

    H Sudarsana Rao; B Ramesh Babu

    2007-10-01

    There is no direct method for design of beams. In general the dimensions of the beam and reinforcement are initially assumed and then the interaction formula is used to verify the suitability of chosen dimensions. This approach necessitates few trials for coming up with an economical and safe design. This paper demonstrates the applicability of Artificial Neural Networks (ANN) and Genetic Algorithms (GA) for the design of beams subjected to moment and shear. A hybrid neural network model which combines the features of feed forward neural networks and genetic algorithms has been developed for the design of beam subjected to moment and shear. The network has been trained with design data obtained from design experts in the field. The hybrid neural network model learned the design of beam in just 1000 training cycles. After successful learning, the model predicted the depth of the beam, area of steel, spacing of stirrups required for new problems with accuracy satisfying all design constraints. The various stages involved in the development of a genetic algorithm based neural network model are addressed at length in this paper.

  10. Nonlinear Equations for Bending of Rotating Beams with Application to Linear Flap-Lag Stability of Hingeless Rotors

    Science.gov (United States)

    Hodges, D. H.; Ormiston, R. A.

    1973-01-01

    The nonlinear partial differential equations for the flapping and lead-lag degrees of freedom of a torisonally rigid, rotating cantilevered beam are derived. These equations are linearized about an equilibrium condition to study the flap-lag stability characteristics of hingeless helicopter rotor blades with zero twist and uniform mass and stiffness in the hovering flight condition. The results indicate that these configurations are stable because the effect of elastic coupling more than compensates for the destabilizing flap-lag Coriolis and aerodynamic coupling. The effect of higher bending modes on the lead-lag damping was found to be small and the common, centrally hinged, spring restrained, rigid blade approximation for elastic rotor blades was shown to be resonably satisfactory for determining flap-lag stability. The effect of pre-cone was generally stabilizing and the effects of rotary inertia were negligible.

  11. Using Finite Element Software to Simulation Fracture Behavior of Three-point Bending Beam with Initial Crack

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2013-05-01

    Full Text Available using computation software to simulate fracture behaviors of structures can shorten the time to estimate safety of engineering structures and reduce a lot of cost of experiment. However three dimensional numerical simulation for fracture process is a challenging issue, because the convergence and accuracy are not easily obtained and high computational cost is generated. In this paper, three new fracture mechanics models, including cohesive model, virtual crack closure technique (short for VCCT and extended finite element method (short for XFEM have been utilized to simulate and analysis the fracture process of the three-point bending beam with initial notch based on the finite element software platform –Abaqus version 6.11. The numerical results have shown that three different methods can be used to simulate different fracture toughness materials and fracture types. Meanwhile,based on Abaqus software platform  and parallel computing technology, this type of simulations could be completed in personal computers.

  12. Bending strain-tunable magnetic anisotropy in Co2FeAl Heusler thin film on KaptonxAE

    Science.gov (United States)

    Gueye, M.; Wague, B. M.; Zighem, F.; Belmeguenai, M.; Gabor, M. S.; Petrisor, T.; Tiusan, C.; Mercone, S.; Faurie, D.

    2014-08-01

    Bending effect on the magnetic anisotropy in 20 nm Co2FeAl Heusler thin film grown on Kapton® has been studied by ferromagnetic resonance and glued on curved sample carrier with various radii. The results reported in this Letter show that the magnetic anisotropy is drastically changed in this system by bending the thin films. This effect is attributed to the interfacial strain transmission from the substrate to the film and to the magnetoelastic behavior of the Co2FeAl film. Moreover, two approaches to determine the in-plane magnetostriction coefficient of the film, leading to a value that is close to λCFA= 14 × 10-6, have been proposed.

  13. Ion beam steering with a high intensity electron beam

    International Nuclear Information System (INIS)

    In conventional theory, steering or bending an ion beam of high energy and high current requires very intense magnetic fields, which are both uneconomical and bulky. This problem is even more severe for a singly charged ion beam with very high atomic number, which requires large magnetic field energy both to bend and also to focus the beam against its self electric field. In this paper we present a new and simple technique, which will substantially alleviate these problems

  14. Fatigue crack behavior of RC beams strengthened with CFL under cylic bending loads

    Science.gov (United States)

    Zheng, Xiaohong; Huang, Peiyan; Guo, Xinyan

    2008-11-01

    A mechanical model of cracked reinforced concrete (RC) beams strengthened with carbon fiber laminate (CFL) is proposed to establish the theoretical relationship among the crack height (a), the number of fatigue loading cycles (n), and the fatigue life (N), and the main crack growth behavior is discussed. Moreover, some fatigue tests of the RC beams strengthened with CFL were carried out on material testing system (MTS) to investigate the crack growth rate (da/dn). The analysis results show that the crack growth behavior of RC beams strengthened with CFL may be divided into three stages: 1) initiation and rapid growth, 2) steady growth and arrest, 3) unstable growth. At the stage of crack steady growth and arrest, the relationship among, da/dn, n, and N could be expressed as: da/dn=C/(nlnN), where the constant coefficient, C, is determined from the fatigue tests.

  15. Bending of Beam with Free Ends on Non-linear Subsoil

    Czech Academy of Sciences Publication Activity Database

    Sysala, Stanislav

    Ostrava: VŠB-TUO, 2010 - (Frydrýšek, K.), s. 1-17 ISBN 978-80-248-2256-3. [Mechanical Structures and Foundation Engineering 2010. Ostrava (CZ), 13.09.2010-13.09.2010] Institutional research plan: CEZ:AV0Z30860518 Keywords : beam on subsoil * non-linearity * semi-coercivity Subject RIV: BA - General Mathematics

  16. Elastic Scattering of Electron Vortex Beams in Magnetic Matter

    Science.gov (United States)

    Edström, Alexander; Lubk, Axel; Rusz, Ján

    2016-03-01

    Elastic scattering of electron vortex beams on magnetic materials leads to a weak magnetic contrast due to Zeeman interaction of orbital angular momentum of the beam with magnetic fields in the sample. The magnetic signal manifests itself as a redistribution of intensity in diffraction patterns due to a change of sign of the orbital angular momentum of the electron vortex beam. While in the atomic resolution regime the magnetic signal is most likely under the detection limits of present transmission electron microscopes, for electron probes with high orbital angular momenta, and correspondingly larger spatial extent, its detection is predicted to be feasible.

  17. Efficient bending and focusing of light beam with all-dielectric subwavelength structures

    Science.gov (United States)

    Shen, Yue; Luo, Xiangang

    2016-05-01

    In this paper, all-dielectric subwavelength structures are proposed to construct beam deflectors and lenses that modulate the light fields efficiently. These devices are composed of planar array of silicon pyramids with spatially varying geometric shapes, thereby introducing arbitrary phase shift to the propagating light. Meanwhile, owing to the intrinsic low-reflection property, average reflectance as low as 10% is accomplished. The lenses were rigorously designed in both one-dimensional (1D) and two-dimensional (2D) cases. Due to the symmetry of the unit cell, there is no limitation on the polarization state of the incident light. Since no plasmonic loss is incorporated, this design could meet the requirement of wavefront manipulation for laser beams.

  18. Study of the increase in bending stiffness on timber beams reinforced with composite materials

    OpenAIRE

    Rosa García, M. Pilar de la; González García, Nieves; Cobo Escamilla, Alfonso

    2014-01-01

    It is common to find structures that need to be reinforced due to deterioration or because the function of the building changes. The economic cost involved in these forms of interventions is considerable. Therefore, it is interesting to progress in the existing strengthening techniques and the study of new reinforcement systems. This paper analyses the behaviour of timber beams reinforced with carbon and basalt fiber composite materials. The main objective of this study is to test the stiffne...

  19. 古建筑木结构叠合梁与组合梁弯曲受力研究%Bending analysis on composite beam and combination beam of Chinese ancient wooden buildings

    Institute of Scientific and Technical Information of China (English)

    周乾; 闫维明

    2012-01-01

    采用力学分析方法,研究了古建筑木结构叠合梁与组合梁弯曲受力问题。以工程中常见的矩形木梁为例,讨论了如下3个问题:1)单梁开裂形成叠合梁后的弯曲受力性能;2)叠合梁与组合梁弯曲受力性能的区别;3)古建筑叠合梁"工字形"抗弯截面的合理性。结果表明:1)单梁开裂后形成叠合梁,将导致截面弯应力峰值大幅度增加;2)单梁加固采用组合梁做法比叠合梁做法更能节约材料且效果更好,且采用钢材加固木梁比木材加固木梁所需截面尺寸小;3)古建筑叠合梁"工字形"截面与相应等高度矩形截面相比,受弯承载力变化不大,具有合理性。%By mechanical analysis methods,internal forces of composite beam and combination beam of Chinese ancient wooden buildings under bending loads were studied.A typical rectangular beam was taken as an example to discuss the following problems: 1) variation of bending stress distribution of the beam after it cracked completely to form a composite beam;2) when the beam was considered to be strengthened by composite beam or combination beam,the difference of bending performance between them;3) rationality of "I-section" type of composite beam or combination beam of Chinese ancient buildings.Results show that:1) after a single beam cracks completely to form a composite beam,its peak bending stress value increases greatly,which may make itself destroyed;2) when a single beam is strengthened by an additional beam,the combination beam is better than the composite beam,and steel is better than wood so far as strengthening material is concerned;3) bending capability of "I-section" type of composite beam or combination beam of Chinese ancient buildings changes little compared to that of rectangular section type,which reflects its rationality.

  20. Deflection Analysis of Cantilever Composite Beam for Large Deflection Bending%悬臂组合梁大挠度弯曲的挠度分析

    Institute of Scientific and Technical Information of China (English)

    杨骁; 刘璐

    2012-01-01

    It is assumed that the deflections at the axial lines of the tow sub-beams are equivalent in the bending behavior of the bi-material composite beam. Nevertheless, it is not true in reality. Based on theory of the large deflection bending of beam, the bendings of the cantilever non-connected composite beam and the cantilever complete connected composite beam subjected to a bending couple at the free end were investigated, respectively. The deflections at the axial lines of the two sub-beams were examined, and the differences between them were revealed. It was shown that the deflections of the two sub-beams are e-quivalent with each other only in the case of the small deflection bending of the composite beam, while they are not equal in the large deflection bending of the composite beam. The deflection differences of the sub-beams at the free end are increased with the bending couple increasing, and decreased with the stiffness ratio increasing. Furthermore, for the cantilever non-connected composite beam, the deflection of the bottom sub-beam is larger than that of the top sub-beam, while, for the cantilever complete connected composite beam, the deflection of the bottom sub-beam is less than that of the top sub-beam.%目前,在两种材料组合梁弯曲变形研究中,通常假设两子梁轴线的挠度相等,然而,实际情况并非如此.基于梁的大挠度弯曲理论,分别研究了悬臂非连接叠梁和悬臂完全连接组合梁在端部力偶作用下的弯曲,考察了两子梁轴线的挠度,揭示了子梁轴线挠度的差异.结果表明:组合梁小挠度弯曲的两子梁挠度相等,而对于组合梁的大挠度弯曲,两子梁挠度并不相等;子梁自由端处的挠度差随着端部弯曲力偶的增加而增加,随着子梁刚度比的增加而减少.并且,对于悬臂非连接叠梁,其下部子梁的挠度大于上部子梁的挠度,而对于悬臂完全连接组合梁,其下部子梁的挠度小于上部子梁的挠度.

  1. High-field superconducting window-frame beam-transport magnets

    International Nuclear Information System (INIS)

    The window-frame design for high-field superconducting beam-transport magnets was first applied to two, 2-m-long, 4-T modules of an 80 bending magent which has operated for nine years in the primary proton beam line at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). The design of two 1.5-m long, 7.6-cm cold-bore superconducting windowframe magnets, described in this paper, intended for the external proton beam transport system at the AGS incorporated evolutionary changes. These magnets generated a maximum aperture field of 6.8 T with a peak field in the dipole coil of 7.1 T. Measured fields are very accurate and are compared to values calculated using the computer programs LINDA and POISSON. Results of quench-propagation studies demonstrate the excellent thermal stability of the magnets. The magnets quench safely without energy extraction at a maximum current density, J = 130 kA/cm2 in the superconductor, corresponding to J = 57.6 kA/cm2 overall the conductor at B = 6.7 T

  2. Beam dynamics study and design of 348° compression magnet for neutron time of flight (n-TOF) facility

    International Nuclear Information System (INIS)

    A n-TOF experiment requires 1 nsec duration pulses to get better energy resolution. The paper presents the design of a compression magnet that can compress a 10 nsec electron pulse to ∼ 1 nsec having energy variation from 18–30 MeV. A zero gradient, 5-sector magnet that will bend the beam through 348° is designed for the same. The beam dynamics to calculate energy spread, design of sector magnet and the simulation results of CST particle studio are presented. A combination of magnetic fields 0.1 T, 0.05 T and 0.02 T in different sectors of the magnet give the compressed pulse width of ∼ 1.3 nsec

  3. Justification for the development of a bending magnet beamline at sector 10 at the APS.

    Energy Technology Data Exchange (ETDEWEB)

    Kemner, K. M.; Biosciences Division

    2006-09-18

    The long-planned and much-needed merger of EnviroCAT into the Materials Research Collaborative Access Team (MR-CAT) will provide dedicated state-of-the-art facilities that are critical to research on a broad range of issues in environmental sciences. These CATs will focus on developing a bending magnet (BM) beamline for x-ray absorption fine structure (XAFS) and micro x-ray analysis of environmental samples through integration with existing insertion device (ID) capabilities in XAFS, micro x-ray analysis, and x-ray scattering. In addition, the expanded MR-CAT will serve as the hub of personnel and laboratory infrastructure support for molecular environmental science and biogeochemical science at the Advanced Photon Source (APS). In conjunction with the merger of EnviroCAT into MR-CAT, the US Environmental Protection Agency (EPA) will become a member institution of MR-CAT, joining the present members (University of Notre Dame, Illinois Institute of Technology, University of Florida, British Petroleum, and Argonne's Chemical Engineering and Biosciences Division). The motivation for blending capabilities meeting the needs of EnviroCAT users into the MR-CAT facilities is the explosion of synchrotron-radiation-based research in the field known as molecular environmental science (MES). This research is driven largely by the need to remediate contaminated environmental materials and to understand the scientific foundations that govern contaminant transport in the environment. Synchrotron radiation is playing a crucial role in solving environmental science problems by offering x-ray-based analytical techniques for detailed molecular- and atomic-level studies of these systems. This document focuses on the scientific justification for developing a specific type of BM beamline capability at Sector 10 for XAFS and micro x-ray analysis to support the growing MES community. However, the modification of Sector 10 will meet other future needs by providing (1) an existing

  4. Single-Plane Magnetically Focused Elongated Small Field Proton Beams.

    Science.gov (United States)

    McAuley, Grant A; Slater, James M; Wroe, Andrew J

    2015-08-01

    We previously performed Monte Carlo simulations of magnetically focused proton beams shaped by a single quadrapole magnet and thereby created narrow elongated beams with superior dose delivery characteristics (compared to collimated beams) suitable for targets of similar geometry. The present study seeks to experimentally validate these simulations using a focusing magnet consisting of 24 segments of samarium cobalt permanent magnetic material adhered into a hollow cylinder. Proton beams with properties relevant to clinical radiosurgery applications were delivered through the magnet to a water tank containing a diode detector or radiochromic film. Dose profiles were analyzed and compared with analogous Monte Carlo simulations. The focused beams produced elongated beam spots with high elliptical symmetry, indicative of magnet quality. Experimental data showed good agreement with simulations, affirming the utility of Monte Carlo simulations as a tool to model the inherent complexity of a magnetic focusing system. Compared to target-matched unfocused simulations, focused beams showed larger peak to entrance ratios (26% to 38%) and focused simulations showed a two-fold increase in beam delivery efficiency. These advantages can be attributed to the magnetic acceleration of protons in the transverse plane that tends to counteract the particle outscatter that leads to degradation of peak to entrance performance in small field proton beams. Our results have important clinical implications and suggest rare earth focusing magnet assemblies are feasible and could reduce skin dose and beam number while delivering enhanced dose to narrow elongated targets (eg, in and around the spinal cord) in less time compared to collimated beams. PMID:25414143

  5. Unique determination of a single crack in a uniform simply supported beam in bending vibration

    Science.gov (United States)

    Fernández-Sáez, José; Morassi, Antonino; Pressacco, Martina; Rubio, Lourdes

    2016-06-01

    In this paper we consider one of the basic inverse problems in damage detection based on natural frequency data, namely the identification of a single open crack in a uniform simply supported beam from measurement of the first and the second natural frequency. It is commonly accepted in the literature that the knowledge of this set of spectral data allows for the unique determination of the severity and the position (up to symmetry) of the damage. However, in spite of the fact that many numerical evidences are in support of this property, the result is rigorously proved only when the severity of the crack is small. In this paper we definitely show, by means of an original constructive method, that the above result holds true for any level of crack severity.

  6. Bending calculation analysis of composite beam with bolt connection%螺栓连接组合梁的弯曲计算

    Institute of Scientific and Technical Information of China (English)

    郭作杰

    2015-01-01

    由于螺栓连接组合梁的弯曲是一个静不定问题,一些文献把螺栓连接组合梁弯曲作为静定问题来处理,有时会导致螺栓连接组合梁叠层梁弯曲应力、弯曲挠度、螺栓剪力的计算结果存在很大的误差。本文按静不定问题研究了螺栓连接组合梁弯曲变形,导出了螺栓连接组合梁弯曲的弯曲应力、弯曲挠度、螺栓剪力计算公式。通过有限元法及实验验证了把螺栓连接组合梁弯曲作为静不定问题处理是正确的。%The bending of composite beam with bolt connection is a statically indeterminate problem in fact;some mechanics of materials textbooks related take it as statically determinate problem, which may lead to large calculation error for the bending stress, bending deflection and shear force of composite beam with bolt connection. By taking it as statically indeterminate structures, the calculation formula for bending stress, bending deflection and shear force of composite beam with bolt connection were derived. The finite element method and experiments verify that taking composite beam with bolt connection as a statically indeterminate problem is right.

  7. Six tesla analyzing magnet for heavy-ion beam transport

    International Nuclear Information System (INIS)

    A superconducting analyzer magnet for particle beam deflection has been designed and is being fabricated for use at the Argonne Tandem-Linac Accelerator System (ATLAS). This six tesla magnet will provide 450 of deflection for the heavy-ion beams from the ATLAS tandem electrostatic accelerator and together with its twin will replace the existing conventional 900 analyzer magnet which will become inadequate when ATLAS is completed

  8. 轴向扩散下不可压饱和多孔简支弹性杆的弯曲%Bending of simply supported incompressible saturated poroelastic beams with axial diffusion

    Institute of Scientific and Technical Information of China (English)

    杨骁; 刘鑫

    2008-01-01

    Based on the mathematical model of the bending of the incompressible saturated poroelastic beam with axialdiffusion, the quasi-static bendings of the simply supported poroelastic beam subjected to a suddenly applied constant loadwere investigated, and the analytical solutions were obtained for different diffusion conditions of the pore fluid at the beamends. The deflections, the bending moments of the solid skeleton and the equivalent couples of the pore pressures werepresented in figures. It is also shown that the behavior of the saturated poroelastic beams depends closely on the diffusionconditions at the beam ends, especially for the equivalent couples of the pore pressures. It is found that the Mandel-Cryereffect also exists in the bending of the saturated poroelastic beams under specific diffusion conditions at the beam ends.

  9. Relaxation of bending stresses and the reversibility of residual stresses in amorphous soft magnetic alloys

    International Nuclear Information System (INIS)

    The reversibility of residual bending stresses is revealed in ribbon samples of cobalt- and iron-based amorphous alloys Co69Fe3.7Cr3.8Si12.5B11 and Fe57Co31Si2.9B9.1: the ribbons that are free of applied stresses and bent under the action of residual stresses become completely or incompletely straight upon annealing at the initial temperatures. The influence of annealing on the relaxation of bending stresses is studied. Preliminary annealing is found to sharply decrease the relaxation rate of bending stresses, and the initial stage of fast relaxation of these stresses is absent. Complete straightening of preliminarily annealed ribbons is shown to occur at significantly higher temperatures than that of the initial ribbons. Incomplete straightening of the ribbons is explained by the fact that bending stresses relaxation at high annealing temperatures proceeds due to both reversible anelastic deformation and viscous flow, which is a fully irreversible process. Incomplete reversibility is also caused by irreversible processes, such as the release of excess free volume and clustering (detected by small-angle X-ray scattering). The revealed differences in the relaxation processes that occur in the cobalt- and iron-based amorphous alloys are discussed in terms of different atomic diffusion mobilities in these alloys

  10. Relaxation of bending stresses and the reversibility of residual stresses in amorphous soft magnetic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kekalo, I. B.; Mogil’nikov, P. S., E-mail: pavel-mog@mail.ru [National University of Science and Technology MISiS (Russian Federation)

    2015-06-15

    The reversibility of residual bending stresses is revealed in ribbon samples of cobalt- and iron-based amorphous alloys Co{sub 69}Fe{sub 3.7}Cr{sub 3.8}Si{sub 12.5}B{sub 11} and Fe{sub 57}Co{sub 31}Si{sub 2.9}B{sub 9.1}: the ribbons that are free of applied stresses and bent under the action of residual stresses become completely or incompletely straight upon annealing at the initial temperatures. The influence of annealing on the relaxation of bending stresses is studied. Preliminary annealing is found to sharply decrease the relaxation rate of bending stresses, and the initial stage of fast relaxation of these stresses is absent. Complete straightening of preliminarily annealed ribbons is shown to occur at significantly higher temperatures than that of the initial ribbons. Incomplete straightening of the ribbons is explained by the fact that bending stresses relaxation at high annealing temperatures proceeds due to both reversible anelastic deformation and viscous flow, which is a fully irreversible process. Incomplete reversibility is also caused by irreversible processes, such as the release of excess free volume and clustering (detected by small-angle X-ray scattering). The revealed differences in the relaxation processes that occur in the cobalt- and iron-based amorphous alloys are discussed in terms of different atomic diffusion mobilities in these alloys.

  11. Bending of geometrically nonlinear cantilever beam. Results obtained by Cosserat – Timoshenko and Kirchhoff’s rod theories

    Directory of Open Access Journals (Sweden)

    V.V. Lalin

    2015-02-01

    Full Text Available The problem of verification of different program suites for structural analysis has recently become an important component of the construction science. One of the most extensively used benchmark problem is a classical geometrically nonlinear problem of deflection of the cantilever beam of linear elastic material, under the action of external vertical concentrated load at the free end. In fact, the solution for Kirchhoff’s rod is used as an analytical result. This rod is inextensible and Kirchhoff’s rod theory disregards flexibility of the rod in tension and shear. But in modern program suites Cosserat-Timoshenko rod is often used because Cosserat-Timoshenko rod theory is a geometrically exact theory. It considers not only bending strain but also shear and tensile strain. This means that it is necessary to get a model solution for Cosserat – Timoshenko rod, which can be used for verification of different software suites. This paper presents solutions of the geometrically nonlinear problem obtained by Cosserat – Timoshenko and Kirchhoff’s rod theory with comparison of those results. The findings can be used as a benchmark problem for verification of software suites.

  12. A new method for ultrashort electron pulse-shape measurement using synchrotron radiation from a bending magnet

    International Nuclear Information System (INIS)

    A new nondestructive method for measurement of the longitudinal profile of subpicosecond electron bunches is proposed. The method is based on measurement of spectral intensity correlations in synchrotron radiation. Statistical properties of synchrotron radiation produced by a bunch passing the bending magnet are considered. The signal-to-noise ratio is analyzed in terms of the degeneracy parameter. The degeneracy parameter increases approximately as a third power of the wavelength which makes the visible range of synchrotron radiation to be a natural choice for the spectral intensity correlation measurement. An example of the experimental set-up is also described. (orig.)

  13. A Beamline for High-Pressure Studies at the Advanced Light Source with a Superconducting Bending Magnet as the Source

    OpenAIRE

    Kunz, Martin; MacDowell, Alastair A.; Caldwell, Wendel A.; Cambie, Daniella; Celestre, Richard S.; Domning, Edward E; Duarte, Robert M.; Gleason, Arianna E.; Glossinger, James M.; Kelez, Nicholas; Plate, David W.; Yu, Tony; Zaug, Joeseph M.; Padmore, Howard A.; Jeanloz, Raymond

    2005-01-01

    A new facility for high-pressure diffraction and spectroscopy using diamond anvil high-pressure cells has been built at the Advanced Light Source on Beamline 12.2.2. This beamline benefits from the hard X-radiation generated by a 6 Tesla superconducting bending magnet (superbend). Useful x-ray flux is available between 5 keV and 35 keV. The radiation is transferred from the superbend to the experimental enclosure by the brightness preserving optics of the beamline. These optics are compr...

  14. MX1: a bending-magnet crystallography beamline serving both chemical and macromolecular crystallography communities at the Australian Synchrotron

    International Nuclear Information System (INIS)

    The macromolecular crystallography beamline MX1 at the Australian Synchrotron is described. MX1 is a bending-magnet crystallography beamline at the 3 GeV Australian Synchrotron. The beamline delivers hard X-rays in the energy range from 8 to 18 keV to a focal spot at the sample position of 120 µm FWHM. The beamline endstation and ancillary equipment facilitate local and remote access for both chemical and biological macromolecular crystallography. Here, the design of the beamline and endstation are discussed. The beamline has enjoyed a full user program for the last seven years and scientific highlights from the user program are also presented

  15. Magnetic design and measurement of nonlinear multipole magnets for the APT beam expander system

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, D.B.; Shafer, R.E.; Martinez, R.P. [Los Alamos National Lab., NM (United States); Walstrom, P.L. [Northrop Grumman Corp., Princeton, NJ (United States); Kahn, S.; Jain, A.; Wanderer, P. [Brookhaven National Lab., Upton, NY (United States)

    1997-10-01

    Two prototype nonlinear multipole magnets have been designed for use in the 800-MeV beam test of the APT beam-expansion concept at LANSCE. The iron-dominated magnets each consist of three independent coils, two for producing a predominantly octupole field with a tunable duodecapole component, and one for canceling the residual quadrupole field. Two such magnets, one for shaping each transverse plane, are required to produce a rectangular, uniform beam current density distribution with sharp edges on the APT target. This report will describe the magnetic design of these magnets, along with field measurements, and a comparison to the magnetic design.

  16. Beam dynamics requirement for proposed booster extraction septum magnet

    International Nuclear Information System (INIS)

    To improve the performance of Indus-2 storage ring, it is planned to operate the booster injector at beam energy of 700 MeV, which is presently being operated at 550 MeV. At higher beam energy the beam size will increase and quality of extracted beam from booster will be deteriorated because of the poor magnetic field homogeneity of existing septum magnet. As a consequence it may reduce the injection efficiency of Indus-2. In this perspective, magnetic field homogeneity and good field region of the extraction septum magnet plays a vital role. Thus it is required to upgrade the technical specification of the booster extraction septum magnet. The same has been evolved and its results are presented. (author)

  17. Beam injection with pulsed multipole magnet at UVSOR-III

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, N., E-mail: naoto@nagoya-u.jp [Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aich 464-8603 (Japan); Zen, H. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hosaka, M. [Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aich 464-8603 (Japan); Konomi, T. [UVSOR, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585 (Japan); Adachi, M. [High Energy Accelerator Research Organization, KEK 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Hayashi, K.; Yamazaki, J. [UVSOR, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585 (Japan); Takashima, Y. [Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aich 464-8603 (Japan); Katoh, M. [UVSOR, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585 (Japan)

    2014-12-11

    In this study, we designed and manufactured a pulsed multipole magnet for beam injection into the UVSOR-III ring. A sextupole-like magnetic field could be excited when using the multipole magnet. To compensate for the residual field at the center of the magnet caused by manufacturing imprecisions, thin ferrite sheets were used. The injection experiments at UVSOR-III demonstrated multi-turn injections with the pulsed multipole magnet. The injection efficiency was 23% and the electron beam was stored up to the normal operation current of 300 mA. Moreover, we confirmed that oscillations of stored beams caused by beam injection were drastically suppressed compared with conventional pulsed dipole injection.

  18. Measurement and resulting first and second order approximations for a 9 degree bending magnet in LAMPF's 750-keV transport

    International Nuclear Information System (INIS)

    The three Cartesian components of magnetic field are measured for a 9 degree bending magnet. Measurement errors are corrected and the data is fit to a polynomial which satisfies Maxwell's equations. Particle paths through the magnet are calculated by numerical integration and the corresponding first and second order particle transformation matrices are generated. A parameterization for the first order transformation matrix is developed and the resulting approximations for predicting particle motion in the magnet are compared to the results of the numerical integration

  19. A Finite Element Study of the Bending Behavior of Beams Resting on Two-Parameter Elastic Foundation

    Directory of Open Access Journals (Sweden)

    Iancu-Bogdan Teodoru

    2006-01-01

    Full Text Available Although the Winkler’s model is a poor representation of the many practical subgrade or subbase materials, it is widely used in soil-structure problems for almost one and a half century. The foundations represented by Winkler model can not sustain shear stresses, and hence discontinuity of adjacent spring displacements can occur. This is the prime shortcoming of this foundation model which in practical applications may result in significant inaccuracies in the evaluated structural response. In order to overcome these problem many researchers have been proposed various mechanical foundation models considering interaction with the surroundings. Among them we shall mention the class of two-parameter foundations -- named like this because they have the second parameter which introduces interactions between adjacent springs, in addition to the first parameter from the ordinary Winkler’s model. This class of models includes Filonenko-Borodich, Pasternak, generalized, and Vlasov foundations. Mathematically, the equations to describe the reaction of the two-parameter foundations arc equilibrium ones, and the only difference is the definition of the parameters. For the convenience of discussion, the Pasternak foundation is adopted in present paper. In order to analyse the bending behavior of a Euler-Bernoulli beam resting on two-parameter elastic foundation a (displacement Finite Element (FE formulation, based on the cubic displacement function of the governing differential equation, is introduced. The resulting effects of shear stiffness of the Pasternak model on the mechanical quantities are discussed in comparison with those of the Winkler’s model. Some numerical case studies illustrate the accuracy of the formulation and the importance of the soil shearing effect in the vertical direction, associated with continuous elastic foundation.

  20. Laser cooling of a magnetically guided ultra cold atom beam

    Energy Technology Data Exchange (ETDEWEB)

    Aghajani-Talesh, Anoush

    2014-07-01

    This thesis examines two complimentary methods for the laser cooling of a magnetically guided ultra-cold atom beam. If combined, these methods could serve as a starting point for high-through put and possibly even continuous production of Bose-Einstein condensates. First, a mechanism is outlined to harvest ultra cold atoms from a magnetically guided atom beam into an optical dipole trap. A continuous loading scheme is described that dissipates the directed kinetic energy of a captured atom via deceleration by a magnetic potential barrier followed by optical pumping to the energetically lowest Zeeman sublevel. The application of this scheme to the transfer of ultra cold chromium atoms from a magnetically guided atom beam into a deep optical dipole trap is investigated via numerical simulations of the loading process. Based on the results of the theoretical studies the feasibility and the efficiency of our loading scheme, including the realisation of a suitable magnetic field configuration, are analysed. Second, experiments were conducted on the transverse laser cooling of a magnetically guided beam of ultra cold chromium atoms. Radial compression by a tapering of the guide is employed to adiabatically heat the beam. Inside the tapered section heat is extracted from the atom beam by a two-dimensional optical molasses perpendicular to it, resulting in a significant increase of atomic phase space density. A magnetic offset field is applied to prevent optical pumping to untrapped states. Our results demonstrate that by a suitable choice of the magnetic offset field, the cooling beam intensity and detuning, atom losses and longitudinal heating can be avoided. Final temperatures below 65 μK have been achieved, corresponding to an increase of phase space density in the guided beam by more than a factor of 30.

  1. Laser cooling of a magnetically guided ultra cold atom beam

    International Nuclear Information System (INIS)

    This thesis examines two complimentary methods for the laser cooling of a magnetically guided ultra-cold atom beam. If combined, these methods could serve as a starting point for high-through put and possibly even continuous production of Bose-Einstein condensates. First, a mechanism is outlined to harvest ultra cold atoms from a magnetically guided atom beam into an optical dipole trap. A continuous loading scheme is described that dissipates the directed kinetic energy of a captured atom via deceleration by a magnetic potential barrier followed by optical pumping to the energetically lowest Zeeman sublevel. The application of this scheme to the transfer of ultra cold chromium atoms from a magnetically guided atom beam into a deep optical dipole trap is investigated via numerical simulations of the loading process. Based on the results of the theoretical studies the feasibility and the efficiency of our loading scheme, including the realisation of a suitable magnetic field configuration, are analysed. Second, experiments were conducted on the transverse laser cooling of a magnetically guided beam of ultra cold chromium atoms. Radial compression by a tapering of the guide is employed to adiabatically heat the beam. Inside the tapered section heat is extracted from the atom beam by a two-dimensional optical molasses perpendicular to it, resulting in a significant increase of atomic phase space density. A magnetic offset field is applied to prevent optical pumping to untrapped states. Our results demonstrate that by a suitable choice of the magnetic offset field, the cooling beam intensity and detuning, atom losses and longitudinal heating can be avoided. Final temperatures below 65 μK have been achieved, corresponding to an increase of phase space density in the guided beam by more than a factor of 30.

  2. Simulation of bending stress variation in long buried thick-walled pipes under the earth’s movement using combined linear dynamics and beam theories

    Directory of Open Access Journals (Sweden)

    Salau Tajudeen A.O.

    2014-01-01

    Full Text Available This study reported a simulation approach to the understanding of the interactions between a buried pipe and the soil system by computing the bending stress variation of harmonically-excited buried pipes. The established principles of linear dynamics theory and simple beam theory were utilised in the analysis of the problem of buried pipe bending stress accumulation and its dynamics. With regards to the parameters that influence the bending stress variations, the most important are the isolation factor, uniform external load, and the corresponding limiting conditions. The simulated mathematical expressions, containing static and dynamic parameters of the buried pipe and earth, were coded in Fortran programming language and applied in the simulation experiment. The results obtained showed that harmonically-excited buried thick-walled pipe became stable and effective when the ratio of the natural frequency of vibration to the forced frequency is greater than 2.0, whenever the damped factor is used as the control parameter for the maximum bending stress. The mirror image of the stress variation produces variation in the location of the maximum bending stress in quantitative terms. The acceptable pipe materials for the simulated cases must have yield strength in bending greater than or equal to 13.95 MPa. The results obtained in this work fill a gap in the literature and will be useful to pipeline engineers and designers, as well as to environmental scientists in initialising and controlling environmental issues and policy formulation concerning the influence of buried pipe on the soil and water in the environment.

  3. Estimation of the Beam Width in Magnetic Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    O.N. Peregudov

    2010-01-01

    Full Text Available A method for estimation of the beam width in magnetic sector mass spectrometers is proposed. This method consists in the restoration of the initial ion density distribution function in a beam cross-section before the receiving collector slit and can be used for the qualitative estimation of the mass spectrometer ion-optical scheme.

  4. Fringe Field Effects on Bending Magnets, Derived for TRANSPORT/TURTLE

    CERN Document Server

    Blitz, Sam

    2013-01-01

    A realistic magnetic dipole has complex effects on a charged particle near the entrance and exit of the magnet, even with a constant and uniform magnetic field deep within the interior of the magnet. To satisfy Maxwell's equations, the field lines near either end of a realistic magnet are significantly more complicated, yielding non-trivial forces. The effects of this fringe field are calculated to first order, applying both the paraxial and thin lens approximations. We find that, in addition to zeroth order effects, the position of a particle directly impacts the forces in the horizontal and vertical directions.

  5. Diagnostic neutral beams for plasma studies in magnetic fusion devices

    International Nuclear Information System (INIS)

    Nowadays, low-divergent, quasi-stationary neutral beams are widely used in magnetic fusion devices as a diagnostic tool providing unique information about plasma parameters. Essentially, a diagnostic determines the requirements for the beams, which in many cases consist in sufficiently large current density and energy of the particles so that the beam can penetrate to the plasma core. At the same time, the duration of the beams should overlap that of a plasma shot (∼10 s or longer for large machines). We have developed a number of diagnostic hydrogen beams with a maximum beam energy of 55kV, extracted ion current varying up to 6 A, and pulse duration from several milliseconds to 10 s. The beams are formed by a four electrode ion optical system which makes it possible to provide a low divergent (0.5-0.7 deg.) beam. Additionally, a beam can be focused onto a desired point by proper choice of the curvature radius of the grids. The beams can be modulated with a frequency variable up to 500 Hz. The plasma emitter in the injector is provided by a radiofrequency discharge in hydrogen (deuterium) for long duration beams and, alternatively, by an arc-discharge plasma box for the beams with a duration of up to ∼0.5 s. The arc discharge plasma box provides a higher proton fraction (∼90%) than the RF discharge version (∼60%). The parameters for the different beams developed are presented. (author)

  6. Beam Coupling Impedance of the New Beam Screen of the LHC Injection Kicker Magnets

    CERN Document Server

    Day, H; Caspers, F; Métral, E; Salvant, B; Uythoven, J

    2014-01-01

    The LHC injection kicker magnets experienced significant beam induced heating of the ferrite yoke, with high beam currents circulating for many hours, during operation of the LHC in 2011 and 2012. The causes of this beam induced heating were studied in depth and an improved beam screen implemented to reduce the impedance. Results of measurements and simulations of the new beam screen design are presented in this paper: these are used to predict power loss for operation after long shutdown 1 and for proposed HL-LHC operational parameters.

  7. Design of a new low momentum kaon beam for the AGS

    International Nuclear Information System (INIS)

    The low momentum beam described is to be a unique source of antiprotons as well as kaons. The discussion covers (1) choice of production angle; (2) secondary beams; (3) the use of sector dipole magnets for minimizing aberrations; (4) beam bending magnets; (5) beam separators; and (6) beam acceptance

  8. CSR Impedance Due To A Bend Magnet Of Finite Length With A Vacuum Chamber Of Rectangular Cross Section

    International Nuclear Information System (INIS)

    We study the impedance due to coherent synchrotron radiation (CSR) generated by a short bunch of charged particles passing through a dipole magnet of finite length in a vacuum chamber of a given cross section. Our method represents a further development of the previous studies: we decompose the electromagnetic field of the beam over the eigenmodes of the toroidal chamber and derive a system of equations for the expansion coefficients in the series. We illustrate our general method by calculating the CSR impedance of a beam moving in a toroidal vacuum chamber of rectangular cross section.

  9. Superconducting wiggler magnets for beam-emittance damping rings

    CERN Document Server

    Schoerling, Daniel

    2012-01-01

    Ultra-low emittance beams with a high bunch charge are necessary for the luminosity performance of linear electron-positron colliders, such as the Compact Linear Collider (CLIC). An effective way to create ultra-low emittance beams with a high bunch charge is to use damping rings, or storage rings equipped with strong damping wiggler magnets. The remanent field of the permanent magnet materials and the ohmic losses in normal conductors limit the economically achievable pole field in accelerator magnets operated at around room temperature to below the magnetic saturation induction, which is 2.15 T for iron. In wiggler magnets, the pole field in the center of the gap is reduced further like the hyperbolic cosine of the ratio of the gap size and the period length multiplied by pi. Moreover, damping wiggler magnets require relatively large gaps because they have to accept the un-damped beam and to generate, at a small period length, a large magnetic flux density amplitude to effectively damp the beam emittance....

  10. Nonlinear Optimization of CLIC DRS New Design with Variable Bends and High Field Wigglers

    CERN Document Server

    Ghasem, H.; Alabau-Gonzalvo, J.; Papadopoulou, S.; Papaphilippou, Y.

    2016-01-01

    The new design of CLIC damping rings is based on longitudinal variable bends and high field superconducting wiggler magnets. It provides an ultra-low horizontal normalised emittance of 412 nm-rad at 2.86 GeV. In this paper, nonlinear beam dynamics of the new design of the damping ring (DR) with trapezium field profile bending magnets have been investigated in detail. Effects of the misalignment errors have been studied in the closed orbit and dynamic aperture.

  11. First multi-bend achromat lattice consideration

    International Nuclear Information System (INIS)

    The first proposed lattice for a ‘diffraction-limited light source’ is reported. This approach has now more or less been used for the MAX IV project. By the beginning of 1990, three third-generation synchrotron light sources had been successfully commissioned in Grenoble, Berkeley and Trieste (ESRF, ALS and ELETTRA). Each of these new machines reached their target specifications without any significant problems. In parallel, already at that time discussions were underway regarding the next generation, the ‘diffraction-limited light source (DLSR)’, which featured sub-nm rad electron beam emittance, photon beam brilliance exceeding 1022 and the potential to emit coherent radiation. Also, at about that time, a first design for a 3 GeV DLSR was developed, based on a modified multiple-bend achromat (MBA) design leading to a lattice with normalized emittance of ∊x = 0.5 nm rad. The novel feature of the MBA lattice was the use of seven vertically focusing bend magnets with different bending angles throughout the achromat cell to keep the radiation integrals and resulting beam emittance low. The baseline design called for a 400 m ring circumference with 12 straight sections of 6 m length. The dynamic aperture behaviour of the DLSR lattice was estimated to produce > 5 h beam lifetime at 100 mA stored beam current

  12. Bending and Shear Behavior of Pultruded Glass Fiber Reinforced Polymer Composite Beams With Closed and Open Sections

    Science.gov (United States)

    Estep, Daniel Douglas

    Several advantages, such as high strength-to-weight ratio, high stiffness, superior corrosion resistance, and high fatigue and impact resistance, among others, make FRPs an attractive alternative to conventional construction materials for use in developing new structures as well as rehabilitating in-service infrastructure. As the number of infrastructure applications using FRPs grows, the need for the development of a uniform Load and Resistance Factor Design (LRFD) approach, including design procedures and examples, has become paramount. Step-by-step design procedures and easy-to-use design formulas are necessary to assure the quality and safety of FRP structural systems by reducing the possibility of design and construction errors. Since 2008, the American Society of Civil Engineers (ASCE), in coordination with the American Composites Manufacturers Association (ACMA), has overseen the development of the Pre-Standard for Load and Resistance Factor Design (LRFD) of Pultruded Fiber Reinforced Polymer (FRP) Structures using probability-based limit states design. The fifth chapter of the pre-standard focuses on the design of members in flexure and shear under different failure modes, where the current failure load prediction models proposed within have been shown to be highly inaccurate based on experimental data and evaluation performed by researchers at the West Virginia University Constructed Facilities Center. A new prediction model for determining the critical flexural load capacity of pultruded GFRP square and rectangular box beams is presented within. This model shows that the type of failure can be related to threshold values of the beam span-to-depth ratio (L/h) and total flange width-to-thickness ratio (bf /t), resulting in three governing modes of failure: local buckling failure in the compression flange (4 ≤ L/h < 6), combined strain failure at the web-flange junction (6 ≤ L/h ≤ 10), and bending failure in the tension flange (10 < L/h ≤ 42

  13. Bending and Shear Behavior of Pultruded Glass Fiber Reinforced Polymer Composite Beams With Closed and Open Sections

    Science.gov (United States)

    Estep, Daniel Douglas

    Several advantages, such as high strength-to-weight ratio, high stiffness, superior corrosion resistance, and high fatigue and impact resistance, among others, make FRPs an attractive alternative to conventional construction materials for use in developing new structures as well as rehabilitating in-service infrastructure. As the number of infrastructure applications using FRPs grows, the need for the development of a uniform Load and Resistance Factor Design (LRFD) approach, including design procedures and examples, has become paramount. Step-by-step design procedures and easy-to-use design formulas are necessary to assure the quality and safety of FRP structural systems by reducing the possibility of design and construction errors. Since 2008, the American Society of Civil Engineers (ASCE), in coordination with the American Composites Manufacturers Association (ACMA), has overseen the development of the Pre-Standard for Load and Resistance Factor Design (LRFD) of Pultruded Fiber Reinforced Polymer (FRP) Structures using probability-based limit states design. The fifth chapter of the pre-standard focuses on the design of members in flexure and shear under different failure modes, where the current failure load prediction models proposed within have been shown to be highly inaccurate based on experimental data and evaluation performed by researchers at the West Virginia University Constructed Facilities Center. A new prediction model for determining the critical flexural load capacity of pultruded GFRP square and rectangular box beams is presented within. This model shows that the type of failure can be related to threshold values of the beam span-to-depth ratio (L/h) and total flange width-to-thickness ratio (bf /t), resulting in three governing modes of failure: local buckling failure in the compression flange (4 ≤ L/h bending failure in the tension flange (10 < L/h ≤ 42). Broadly, the proposed equations are predicting critical flexural load capacities within

  14. A computer algorithm for automatic beam steering

    Energy Technology Data Exchange (ETDEWEB)

    Drennan, E.

    1992-06-01

    Beam steering is done by modifying the current in a trim or bending magnet. If the current change is the right amount the beam can be made to bend in such a manner that it will hit a swic or BPM downstream from the magnet at a predetermined set point. Although both bending magnets and trim magnets can be used to modify beam angle, beam steering is usually done with trim magnets. This is so because, during beam steering the beam angle is usually modified only by a small amount which can be easily achieved with a trim magnet. Thus in this note, all steering magnets will be assumed to be trim magnets. There are two ways of monitoring beam position. One way is done using a BPM and the other is done using a swic. For simplicity, beam position monitoring in this paper will be referred to being done with a swic. Beam steering can be done manually by changing the current through a trim magnet and monitoring the position of the beam downstream from the magnet with a swic. Alternatively the beam can be positioned automatically using a computer which periodically updates the current through a specific number of trim magnets. The purpose of this note is to describe the steps involved in coming up with such a computer program. There are two main aspects to automatic beam steering. First a relationship between the beam position and the bending magnet is needed. Secondly a beamline setup of swics and trim magnets has to be chosen that will position the beam according to the desired specifications. A simple example will be looked at that will show that once a mathematical relationship between the needed change of the beam position on a swic and the change in trim currents is established, a computer could be programmed to calculate and update the trim currents.

  15. Thermal management for LLNL/UC/SSRL bending magnet beamline VIII at Stanford Synchrotron Radiation Laboratory

    International Nuclear Information System (INIS)

    All the important heat loads on the elements of Beamline VIII are cataloged. The principal elements are identified and their heat loads tabulated for various loading scenarios. The expected heat loads are those from normal operations including the anticipated performance improvements planned for the SPEAR ring and from abnormal operations due to positional perturbations of the electron beam

  16. Coupled Bending-Bending-Torsion Vibration of a Rotating Pre-Twisted Beam with Aerofoil Cross-Section and Flexible Root by Finite Element Method

    Directory of Open Access Journals (Sweden)

    Bulent Yardimoglu

    2004-01-01

    Full Text Available The purpose of this paper is to extend a previously published beam model of a turbine blade including the centrifugal force field and root flexibility effects on a finite element model and to demonstrate the performance, accuracy and efficiency of the extended model for computing the natural frequencies. Therefore, only the modifications due to rotation and elastic root are presented in great detail. Considering the shear center effect on the transverse displacements, the geometric stiffness matrix due to the centrifugal force is developed from the geometric strain energy expression based on the large deflections and the increase of torsional stiffness because of the axial stress. In this work, the root flexibility of the blade is idealized by a continuum model unlike the discrete model approach of a combination of translational and rotational elastic springs, as used by other researchers. The cross-section properties of the fir-tree root of the blade considered as an example are expressed by assigning proper order polynomial functions similar to cross-sectional properties of a tapered blade. The correctness of the present extended finite element model is confirmed by the experimental and calculated results available in the literature. Comparisons of the present model results with those in the literature indicate excellent agreement.

  17. 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.

  18. 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.

  19. 拉伸和弯曲耦合层合梁应力分析%ANALYSIS OF STRESS FOR LAMINATE BEAM WITH TENSION AND BEND COUPLING

    Institute of Scientific and Technical Information of China (English)

    马功勋

    2001-01-01

    The differentiating equations of displacements have been developed for laminate beam under the coupling of tension and bend. For laminate beam with tension and bend coupling,the calculating formula of normal stress and layer shear stress were educed. The stresses of rule-normal and asymmetrical laminate beam were analyzed. The distribution of stresses is asymmetrical.As the number of laminate series is more than 8, the distribution of asymmetrical stresses tends to symmetrical distribution.%本文建立了拉伸和弯曲耦合层合梁的位移微分方程。导出了拉弯耦合层合梁正应力和层间剪应力的计算公式,分析了规则非对称正交层合梁的应力具有非对称特性。当规则非对称正交层合梁的铺层组数大于8时,其应力趋于对称分布。

  20. Atomic beam study of a superconductor's magnetic vortex lattice

    International Nuclear Information System (INIS)

    We have developed an atomic beam technique for studying magnetic vortices and vortex lattices of superconductors. Atoms moving near a superconductor's surface see a fluctuating magnetic field as they pass vortices. This field may drive magnetic resonance transitions between hyperfine states. Measuring the magnetic resonance transition probability as a function of atom velocity probes the vortex lattice autocorrelation function. We demonstrate this technique by studying the vortex lattice of a niobium film sample and measuring the sample's penetration depth. We also identify a systematic problem that we think thwarted an earlier attempt to experimentally realize this technique. copyright 1997 The American Physical Society

  1. Analyzer of energy spectra of a magnetized relativistic electron beam

    International Nuclear Information System (INIS)

    Analyzer of magnetized REB instant energy spectrum is described. The analyzer operation principle is based on the application of a sharp change of the direction of force lines of a magnetic field which is non-adiabatic for the beam electrons. The analyzer design is described, the main factors effecting the energy resolution are considered. The analyzer serviceability is examined in the course of experiments on plasma heating using a heavy-current microsecond REB at the GOL-3 device. The analyzer energy resolution which does not exceed 10% at 0.8 MeV energy and 20% at 0.3 MeV is determined. Beam energy spectra are obtained in one of the regimes of beam interaction with plasma. The efficiency of beam interaction with plasma determined using the analyzer achieves 30%. 10 refs.; 7 figs

  2. Beaming of particles and synchrotron radiation in relativistic magnetic reconnection

    CERN Document Server

    Kagan, Daniel; Piran, Tsvi

    2016-01-01

    Relativistic reconnection has been invoked as a mechanism for particle acceleration in numerous astrophysical systems. According to idealised analytical models reconnection produces a bulk relativistic outflow emerging from the reconnection sites (X-points). The resulting radiation is therefore highly beamed. Using two-dimensional particle-in-cell (PIC) simulations, we investigate particle and radiation beaming, finding a very different picture. Instead of having a relativistic average bulk motion with isotropic electron velocity distribution in its rest frame, we find that the bulk motion of particles in X-points is similar to their Lorentz factor gamma, and the particles are beamed within about 5/gamma. On the way from the X-point to the magnetic islands, particles turn in the magnetic field, forming a fan confined to the current sheet. Once they reach the islands they isotropise after completing a full Larmor gyration and their radiation is not strongly beamed anymore. The radiation pattern at a given freq...

  3. The nonlinear-electrodynamic bending of the x-ray and gamma-ray in the magnetic field of pulsars and magnetars

    CERN Document Server

    Denisov, V Yu; Svertilov, S I; Denisov, Victor I.; Denisova, Irene P.; Svertilov, Sergey I.

    2001-01-01

    It was shown that according to the non-linear electrodynamics of vacuum electromagnetic rays should bend in the field of magnetic dipole. The angles of ray bending in the gravitational and magnetic fields of pulsars and magnetars were obtained. In the case of pulsars with $b\\sim R\\sim $ 100 km, $B_0\\sim 10^{13} G$ the value of the angle of non-linear electrodynamic bending of a ray in the Heisenberg-Euler theory will reach the value of $\\delta \\psi_{NED}\\sim 30'',$ and in the case of a magnetar with $B_0\\sim 10^{15} G$ the angle $\\delta \\psi_{NED}$ will increase to $\\delta \\psi_{NED}\\sim 1 rad\\sim 60^\\circ .$ The angle of gravitational bending of a ray at neutron star with $r_g$ = 3 km in the same conditions will be equal to $\\delta \\psi_g\\sim 0.06$ rad $\\sim 4^\\circ >.$ Observations can only be made in X- rays and gamma-rays, for which the agnetosphere is quite opaque. Because the distance from the Earth to the well-known pulsars and magnetars is too large to observe the pure effect of a ray bending. The non...

  4. A STUDY OF FRACTURE OF UNIDIRECTIONAL CF/SiC SINGLE EDGE-NOTCHED BEAM UNDER THREE-POINT BENDING- MACRO/MICRO-NUMERICAL MONTE CARLO SIMULATION

    Institute of Scientific and Technical Information of China (English)

    Wang Yang; Cheng Tianle; Xia Yuanming; Jiang Dazhi

    2001-01-01

    In this paper, the fracture process of a unidirectional CF/SiC single edge-notched beam (SENB) under three-point bending (TPB) is studied by means of macro/micro-statistical Monte Carlo simulation. The simulated p-△ curves are in agreement with the experimental results before the peaks of curves, and the simulated microevolution patterns are in agreement with the patterns of the crack surfaces, which have verified this method. It is preliminarily demonstrated that the second turning point in the compliance changing rate curve corresponds to the fracture initiation for experiments on SENB under TPB of unidirectional CF/SiC composites.

  5. Welding an LHC bending magnet held in place by CERN’s hydraulic press

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    A powerful hydraulic press has been installed at CERN. Rated at 27 000 tonnes, it has enough force to lift a weight equivalent to almost four Eiffel towers. The press is used to hold magnets in place as their casings are welded together or opened up.

  6. Emittance preservation during bunch compression with a magnetized beam

    Science.gov (United States)

    Stratakis, Diktys

    2016-03-01

    The deleterious effects of coherent synchrotron radiation (CSR) on the phase-space and energy spread of high-energy beams in accelerator light sources can significantly constrain the machine design and performance. In this paper, we present a simple method to preserve the beam emittance by means of using magnetized beams that exhibit a large aspect ratio on their transverse dimensions. The concept is based in combining a finite solenoid field where the beam is generated with a special optics adapter. Numerical simulations of this new type of beam source show that the induced phase-space density growth from CSR can be notably suppressed to less than 1% for any bunch charge. This work elucidates the key parameters that are needed for emittance preservation, such as the required field and aspect ratio for a given bunch charge.

  7. Emittance preservation during bunch compression with a magnetized beam

    Energy Technology Data Exchange (ETDEWEB)

    Stratakis, Diktys [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-02

    The deleterious effects of coherent synchrotron radiation (CSR) on the phase-space and energy spread of high-energy beams in accelerator light sources can significantly constrain the machine design and performance. In this paper, we present a simple method to preserve the beam emittance by means of using magnetized beams that exhibit a large aspect ratio on their transverse dimensions. The concept is based on combining a finite solenoid field where the beam is generated together with a special optics adapter. Numerical simulations of this new type of beam source show that the induced phase-space density growth can be notably suppressed to less than 1% for any bunch charge. This work elucidates the key parameters that are needed for emittance preservation, such as the required field and aspect ratio for a given bunch charge.

  8. Textile Diamond Dipole and Artificial Magnetic Conductor Performance under Bending, Wetness and Specific Absorption Rate Measurements

    OpenAIRE

    Kamardin, K.; M.K.A. Rahim; Hall, P S; N. A. Samsuri; M. E. Jalil; M. F. Abd Malek

    2015-01-01

    Textile diamond dipole and Artificial Magnetic Conductor (AMC) have been proposed and tested under wearable and body centric measurements. The proposed antenna and AMC sheet are entirely made of textiles for both the substrate and conducting parts, thus making it suitable for wearable communications. Directive radiation patterns with high gain are obtained with the proposed AMC sheet, hence minimizing the radiation towards the human body. In this study, wearable and body centric measurements ...

  9. Electron beam therapy with coil-generated magnetic fields

    International Nuclear Information System (INIS)

    This paper presents an initial study on the issues involved in the practical implementation of the use of transverse magnetic fields in electron beam therapy. By using such magnetic fields the dose delivered to the tumor region can increase significantly relative to that deposited to the healthy tissue. Initially we calculated the magnetic fields produced by the Helmholtz coil and modified Helmholtz coil configurations. These configurations, which can readily be used to generate high intensity magnetic fields, approximate the idealized magnetic fields studied in our previous publications. It was therefore of interest to perform a detailed study of the fields produced by these configurations. Electron beam dose distributions for 15 MeV electrons were calculated using the ACCEPTM code for a 3T transverse magnetic field produced by the modified Helmholtz configuration. The dose distribution was compared to those obtained with no magnetic field. The results were similar to those obtained in our previous work, where an idealized step function magnetic field was used and a 3T field was shown to be the optimal field strength. A simpler configuration was also studied in which a single external coil was used to generate the field. Electron dose distributions are also presented for a given geometry and given magnetic field strength using this configuration. The results indicate that this method is more difficult to apply to radiotherapy due to its lack of symmetry and its irregularity. For the various configurations dealt with here, a major problem is the need to shield the magnetic field in the beam propagation volume, a topic that must be studied in detail

  10. Electron beam characteristics in the hollow beam diode and cusped magnetic field of the Maryland ERA

    International Nuclear Information System (INIS)

    The University of Maryland electron ring accelerator (ERA) concept calls for the formation of an electron ring current by transmission of a hollow relativistic electron beam through a static, azimuthally symmetric, cusped magnetic field. Electron motion is approximately paraxial in the diode and pre-cusp drift region and is axis-encircling in the post-cusp region. Experiments show the electron flow in the diode to be approximately pressureless. The radial thickness of the drifting Brillouin hollow beam is derived from a radial force balance equation. Time-resolved measurements of the beam current and energy are made by measuring the extrapolated range of the beam in aluminum targets. These measurements are analyzed with a model of the diode as a terminating impedance driven by a transmission line. Beam motion in the cusped field region is analyzed. Beam dynamics in the post-cusp region are studied by examining the interaction of a hollow rotating beam with its self-induced potentials in a cylindrical box with conducting walls and ends. The energy of the self-induced electric and magnetic potentials is much less than the kinetic energy of the beam electrons for cases approximating experimental conditions

  11. Bending of Layer-by-Layer Films Driven by an External Magnetic Field

    OpenAIRE

    Osvaldo N. Oliveira Jr.; Ricardo Paupitz; Pereira-da-Silva, Marcelo A.; Carlos J. L. Constantino; Mariselma Ferreira; Antonio Riul; Dos Santos, David S.; Galvão, Douglas S.; Miyazaki, Celina M.

    2013-01-01

    We report on optimized architectures containing layer-by-layer (LbL) films of natural rubber latex (NRL), carboxymethyl-chitosan (CMC) and magnetite (Fe3O4) nanoparticles (MNPs) deposited on flexible substrates, which could be easily bent by an external magnetic field. The mechanical response depended on the number of deposited layers and was explained semi-quantitatively with a fully atomistic model, where the LbL film was represented as superposing layers of hexagonal graphene-like atomic a...

  12. Beam director design report

    Energy Technology Data Exchange (ETDEWEB)

    Younger, F.C.

    1986-08-01

    A design and fabrication effort for a beam director is documented. The conceptual design provides for the beam to pass first through a bending and focusing system (or ''achromat''), through a second achromat, through an air-to-vacuum interface (the ''beam window''), and finally through the vernier steering system. Following an initial concept study for a beam director, a prototype permanent magnet 30/sup 0/ beam-bending achromat and prototype vernier steering magnet were designed and built. In volume II, copies are included of the funding instruments, requests for quotations, purchase orders, a complete set of as-built drawings, magnetic measurement reports, the concept design report, and the final report on the design and fabrication project. (LEW)

  13. Beam director design report

    International Nuclear Information System (INIS)

    A design and fabrication effort for a beam director is documented. The conceptual design provides for the beam to pass first through a bending and focusing system (or ''achromat''), through a second achromat, through an air-to-vacuum interface (the ''beam window''), and finally through the vernier steering system. Following an initial concept study for a beam director, a prototype permanent magnet 300 beam-bending achromat and prototype vernier steering magnet were designed and built. In volume II, copies are included of the funding instruments, requests for quotations, purchase orders, a complete set of as-built drawings, magnetic measurement reports, the concept design report, and the final report on the design and fabrication project

  14. System of formation of magnetic fields for scanning charged particle beam along an arbitrary trajectory on a target

    International Nuclear Information System (INIS)

    The paper deals with the results of the development of new scanning system at JINR, which is characterized by the following features. Bending magnets have windings with a large quantity of ampere-turns operating at relatively low frequencies (≤20 Hz) to save the reactive power within reasonable limits. Power supplies of the windings use the feedback system to generate currents of the given shape and amplitude. The basic design features and parameters of the magnet prototype, as well as the results of development and testing the electronic circuit for supply of the magnet by the current with the predetermined shape are presented. The calculation results of the density distributions of the different ions on the target in one of the beam lines of the cyclotron U-400M are presented. The parameters of the new scanners were used in these calculations

  15. 饱和多孔弹性Timoshenko悬臂梁的拟静力弯曲%QUASI-STATIC BENDING OF SATURATED POROELASTIC TIMOSHENKO CANTILEVER BEAM

    Institute of Scientific and Technical Information of China (English)

    杨骁; 姜莹莹

    2011-01-01

    在经典单相Timoshenko梁变形和孔隙流体仅沿多孔梁轴向运动的假定下,基于不可压饱和多孔介质的三维理论,论文首先建立了横观各向同性饱和多孔弹性Timoshenko悬臂梁拟静力弯曲的一维数学模型,并给出了相应的边界条件.其次,利用Laplace变换及其数值逆变换,分析了端部不同渗透条件下,饱和多孔弹性Timoshenko悬臂梁在端部梯载荷作用下的拟静力响应,给出了饱和多孔Timoshenko悬臂梁弯曲时挠度、弯矩以及孔隙流体压力等效力偶等随时间的响应曲线,并与饱和多孔Euler-Bernoulli悬臂梁的响应进行了比较,考察了梁长细比对弯曲响应的影响.数值结果表明:固相骨架与孔隙流体的相互作用具有粘性效应,梁弯曲的拟静态挠度具有蠕变行为,端部渗透条件对梁的弯曲变形有显著的影响,并且,饱和多孔弹性Timoshenko悬臂梁的拟静态响应亦存在Mandel-Cryer现象.%Based on the three-dimensional theory of incompressible saturated porous media, a one-dimensional model for quasi-static bending of a transversely isotropic saturated poroelastic Timoshenko cantilever beam is established with assumptions of both deformation of single-phase beam and movement of pore fluid only in the axial direction. The corresponding boundary conditions are presented, too. The quasi-static bending of the saturated poroelastic beams subjected to a step load at its free end, with different end permeability conditions, is analyzed by the Laplace transform and its numerical inverse transform. The variations of the deflections, bending moments and the equivalent couples of the pore fluid pressure against the time are shown in figures and are compared with those of the saturated poroelastic Euler-Bernoulli cantilever beam. The effect of the slenderness ratio of the beam is examined. It is shown that the interaction coefficient between the solid skeleton and pore fluid plays a role as viscidity, and the

  16. Fast magnetic field penetration into an intense neutralized ion beam

    International Nuclear Information System (INIS)

    Experiments involving propagation of neutralized ion beams across a magnetic field indicate a magnetic field penetration time determined by the Hall resistivity rather than the Spitzer or Pedersen resistivity. In magnetohydrodynamics the Hall current is negligible because electrons and ions drift together in response to an electric field perpendicular to the magnetic field. For a propagating neutralized ion beam, the ion orbits are completely different from the electron orbits and the Hall current must be considered. There would be no effect unless there is a component of magnetic field normal to the surface which would usually be absent for a good conductor. It is necessary to consider electron inertia and the consequent penetration of the normal component to a depth c/ωp. In addition it is essential to consider a component of magnetic field parallel to the velocity of the beam which may be initially absent, but is generated by the Hall effect. The penetration time is determined by whistler waves rather than diffusion

  17. Magnetic materials. Trend in magnetic materials, expectations for synchrotron beam, neutron and muon

    International Nuclear Information System (INIS)

    Recently, to obtain higher performance both soft and hard magnetic materials, nano-structural control become indispensable. Because of this circumstance, researcher needs both local precise information and averaged hierarchical information to reveal origin of material performance. In order to do so, utilizing quantum beam, i.e. synchrotron beam, neutron and muon, analysis is important. In this article, examples of utilizing quantum beam analysis for magnetic material research are introduced. In addition, importance of quantifying material data will be mentioned for next generation material research. (author)

  18. Modulational instability of intense laser beam in magnetized plasma

    International Nuclear Information System (INIS)

    The nonlinear dispersion relation is derived for an intense left-hand elliptically polarized laser beam propagating through magnetized plasma by means of the Lorentz transformation. In terms of the Karpman method, the nonlinear governing equation for the envelope of the laser field is obtained. The modulational instability of the intense left-hand elliptically polarized laser beam in magnetized plasma is analyzed and the temporal growth rate of modulational instability is found. The analysis shows that the maximum growth rate of self-modulation instability is obviously smaller for magnetized plasma compared to the unmagnetized case. It is also shown that the temporal growth rate of modulational instability is increased significantly near the critical surface in a laser-plasma. (authors)

  19. Gaussian laser beam in a magnetized plasma. 2

    International Nuclear Information System (INIS)

    Properties of a laser beam propagating perpendicular to the external magnetic field in a plasma are investigated theoretically. The beam is represented by a Helmholtz equation in almost all plasma parameter space. For the upper hybrid wave region the wave equation turns to a hyperbolic partial differential equation. It is shown that both equations can be exactly solved by using a method of separation of variables and that solutions having Gaussian profiles lateral to the propagation direction are obtained. An appreciable difference between two solutions appears in their phase factors. Owing to the asymmetry of the configuration around the axis of wave propagation the cross sections of beams take shapes of ellipse and each beam has two different focus points. (author)

  20. Beam stability improvement of the HIMAC synchrotron using a feed-forward system for magnet power supplies

    Energy Technology Data Exchange (ETDEWEB)

    Katagiri, K., E-mail: tag410@nirs.go.jp [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Furukawa, T.; Mizushima, K. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Uchiyama, H. [Accelerator Engineering Corporation (AEC), 3-8-5 Konakadai, Inage, Chiba 263-0043 (Japan); Takeshita, E.; Himukai, T.; Sato, S.; Iwata, Y.; Shirai, T.; Noda, K. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2011-12-15

    In order to realize a precise dose distribution in heavy-ion cancer therapy, high beam stability is required for the accelerator complex. Owing to load fluctuation caused by the upper ring, which is one of the two rings in HIMAC, current dips of Almost-Equal-To 5-10 Hz were observed in the power supply for the bending/quadrupole magnet of the other lower ring. The parameters of the beam stability, such as the spill variation, the beam position, and the size, were adversely affected by the current dips. In order to suppress these current dips, we developed a new feed-forward system in the magnet power supply. We verified the performance of the feed-forward system by measuring the suppression of the current dips. We also performed beam experiments to measure the variation of the horizontal tune and the structure of the beam spill, which is slowly extracted by the resonance method. The experimental result showed that the current dips were successfully reduced by the system to {Delta}I/I {approx} 10{sup -6}. It was also confirmed that the horizontal tune and the spill structure could be stabilized by the current dip suppression.

  1. Beam stability improvement of the HIMAC synchrotron using a feed-forward system for magnet power supplies

    International Nuclear Information System (INIS)

    In order to realize a precise dose distribution in heavy-ion cancer therapy, high beam stability is required for the accelerator complex. Owing to load fluctuation caused by the upper ring, which is one of the two rings in HIMAC, current dips of ≈5–10 Hz were observed in the power supply for the bending/quadrupole magnet of the other lower ring. The parameters of the beam stability, such as the spill variation, the beam position, and the size, were adversely affected by the current dips. In order to suppress these current dips, we developed a new feed-forward system in the magnet power supply. We verified the performance of the feed-forward system by measuring the suppression of the current dips. We also performed beam experiments to measure the variation of the horizontal tune and the structure of the beam spill, which is slowly extracted by the resonance method. The experimental result showed that the current dips were successfully reduced by the system to ΔI/I ∼ 10−6. It was also confirmed that the horizontal tune and the spill structure could be stabilized by the current dip suppression.

  2. Beam stability improvement of the HIMAC synchrotron using a feed-forward system for magnet power supplies

    Science.gov (United States)

    Katagiri, K.; Furukawa, T.; Mizushima, K.; Uchiyama, H.; Takeshita, E.; Himukai, T.; Sato, S.; Iwata, Y.; Shirai, T.; Noda, K.

    2011-12-01

    In order to realize a precise dose distribution in heavy-ion cancer therapy, high beam stability is required for the accelerator complex. Owing to load fluctuation caused by the upper ring, which is one of the two rings in HIMAC, current dips of ≈5-10 Hz were observed in the power supply for the bending/quadrupole magnet of the other lower ring. The parameters of the beam stability, such as the spill variation, the beam position, and the size, were adversely affected by the current dips. In order to suppress these current dips, we developed a new feed-forward system in the magnet power supply. We verified the performance of the feed-forward system by measuring the suppression of the current dips. We also performed beam experiments to measure the variation of the horizontal tune and the structure of the beam spill, which is slowly extracted by the resonance method. The experimental result showed that the current dips were successfully reduced by the system to Δ I/ I ˜ 10 -6. It was also confirmed that the horizontal tune and the spill structure could be stabilized by the current dip suppression.

  3. Microfabricated Ion Beam Drivers for Magnetized Target Fusion

    Science.gov (United States)

    Persaud, Arun; Seidl, Peter; Ji, Qing; Ardanuc, Serhan; Miller, Joseph; Lal, Amit; Schenkel, Thomas

    2015-11-01

    Efficient, low-cost drivers are important for Magnetized Target Fusion (MTF). Ion beams offer a high degree of control to deliver the required mega joules of driver energy for MTF and they can be matched to several types of magnetized fuel targets, including compact toroids and solid targets. We describe an ion beam driver approach based on the MEQALAC concept (Multiple Electrostatic Quadrupole Array Linear Accelerator) with many beamlets in an array of micro-fabricated channels. The channels consist of a lattice of electrostatic quadrupoles (ESQ) for focusing and of radio-frequency (RF) electrodes for ion acceleration. Simulations with particle-in-cell and beam envelope codes predict >10x higher current densities compared to state-of-the-art ion accelerators. This increase results from dividing the total ion beam current up into many beamlets to control space charge forces. Focusing elements can be biased taking advantage of high breakdown electric fields in sub-mm structures formed using MEMS techniques (Micro-Electro-Mechanical Systems). We will present results on ion beam transport and acceleration in MEMS based beamlets. Acknowledgments: This work is supported by the U.S. DOE under Contract No. DE-AC02-05CH11231.

  4. Planar electron beams in a wiggler magnet array

    Indian Academy of Sciences (India)

    Arti Hadap; K C Mittal

    2013-02-01

    Transport of high current (∼kA range with particle energy ∼ 1 MeV) planar electron beams is a topic of increasing interest for applications in high-power (1–10 GW) and high-frequency (10–20 GHz) microwave devices such as backward wave oscillator (BWO), klystrons, gyro-BWOs, etc. In this paper, we give a simulated result for transport of electron beams with velocity $V_{b} = 5.23 × 10^{8}$ cm s-1 , relativistic factor = 1.16, and beam voltage = ∼80 kV in notched wiggler magnet array. The calculation includes self-consistent effects of beam-generated fields. Our results show that the notched wiggler configuration with ∼6.97 kG magnetic field strength can provide vertical and horizontal confinements for a sheet electron beam with 0.3 cm thickness and 2 cm width. The feasibility calculation addresses to a system expected to drive for 13–20 GHz BWO with rippled waveguide parameters as width = 3.0 cm, thickness = 1.0 cm, corrugation depth ℎ = 0.225 cm, and spatial periodicity = 1.67 cm.

  5. 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.

  6. Coupling creep and damage in concrete under high sustained loading: Experimental investigation on bending beams and application of Acoustic Emission technique

    Science.gov (United States)

    Saliba, J.; Loukili, A.; Grondin, F.

    2010-06-01

    Creep and damage in concrete govern the long-term deformability of concrete. Thus, it is important to understand the interaction between creep and damage in order to design reliable civil engineering structures subjected to high level loading during a long time. Many investigations have been performed on the influence of concrete mixture, the effect of the bond between the matrix and the aggregates, temperature, aging and the size effect on the cracking mechanism and fracture parameters of concrete. But there is a lack of results on the influence of the creep loading history. In the present paper, an experimental investigation on the fracture properties of concrete beams submitted to three point bending tests with high levels of sustained load that deals with creep is reported. The results aim first to investigate the ranges of variation of the time response due to creep damage coupled effects under constant load and secondly to evaluate the residual capacity after creep. For this purpose a series of tests were carried out on geometrically similar specimens of size 100x200x800mm with notch to depth ratio of 0.2 in all the test specimens. The exchange of moisture was prevented and beams were subjected to a constant load of 70% and 90% of the maximum capacity. Three point bending test were realized on specimen at the age of 28 days to determine the characteristics of concrete and the maximum load so we could load the specimens in creep. Threepoint bend creep tests were performed on frames placed in a climate controlled chamber [1]. Then after four months of loading, the beams subjected to creep were removed from the creep frames and then immediately subjected to three-point bending test loading up to failure with a constant loading rate as per RILEM-FMC 50 recommendations. The residual capacity on the notched beams and the evolution of the characteristics of concrete due to the basic creep was considered. The results show that sustained loading had a strengthening

  7. Beaming of Particles and Synchrotron Radiation in Relativistic Magnetic Reconnection

    Science.gov (United States)

    Kagan, Daniel; Nakar, Ehud; Piran, Tsvi

    2016-08-01

    Relativistic reconnection has been invoked as a mechanism for particle acceleration in numerous astrophysical systems. According to idealized analytical models, reconnection produces a bulk relativistic outflow emerging from the reconnection sites (X-points). The resulting radiation is therefore highly beamed. Using two-dimensional particle-in-cell simulations, we investigate particle and radiation beaming, finding a very different picture. Instead of having a relativistic average bulk motion with an isotropic electron velocity distribution in its rest frame, we find that the bulk motion of the particles in X-points is similar to their Lorentz factor γ, and the particles are beamed within ˜ 5/γ . On the way from the X-point to the magnetic islands, particles turn in the magnetic field, forming a fan confined to the current sheet. Once they reach the islands they isotropize after completing a full Larmor gyration and their radiation is no longer strongly beamed. The radiation pattern at a given frequency depends on where the corresponding emitting electrons radiate their energy. Lower-energy particles that cool slowly spend most of their time in the islands and their radiation is not highly beamed. Only particles that quickly cool at the edge of the X-points generate a highly beamed fan-like radiation pattern. The radiation emerging from these fast cooling particles is above the burn-off limit (˜100 MeV in the overall rest frame of the reconnecting plasma). This has significant implications for models of gamma-ray bursts and active galactic nuclei that invoke beaming in that frame at much lower energies.

  8. Compact 180 deg magnetic energy analyzer for relativistic electron beams

    International Nuclear Information System (INIS)

    A compact, 180 deg deflection magnetic energy analyzer has been designed and used to measure the energy spectrum of the beam produced by the Tesla Transformer-Pulse forming line type Relativistic Electron Beam (REB) generator being used in the FEL experiments that are currently underway at Institute for Plasma Research. Relativistic electron beams have been used in many applications ranging from free-electron lasers to virtual cathode oscillators and other high power microwave devices. In all these cases, it is required that the electron beam is propagated without considerable loss across a drift region and it is also imperative that accurate energy measurements are required for dependable estimates and analysis regarding the output parameters of the system. In the case of a free-electron laser, the output wavelength of the FEL has a strong dependence on the beam energy and hence it is important to determine as accurately as possible, the energy of the electron beam in order to accurately estimate the FEL radiation frequency

  9. Performance monitoring of large-scale autonomously healed concrete beams under four-point bending through multiple non-destructive testing methods

    Science.gov (United States)

    Karaiskos, G.; Tsangouri, E.; Aggelis, D. G.; Van Tittelboom, K.; De Belie, N.; Van Hemelrijck, D.

    2016-05-01

    Concrete is still the leading structural material due to its low production cost and great structural design flexibility. Although it is distinguished by such a high durability and compressive strength, it is vulnerable in a series of ambient and operational degradation factors which all too frequently result in crack formation that can adversely affect its mechanical performance. The autonomous healing system, using encapsulated polyurethane-based, expansive, healing agent embedded in concrete, is triggered by the crack formation and propagation and promises material repair and operational service life extension. As shown in our previous studies, the formed cracks on small-scale concrete beams are sealed and repaired by filling them with the healing agent. In the present study, the crack formation and propagation in autonomously healed, large-scale concrete beams are thoroughly monitored through a combination of non-destructive testing (NDT) methods. The ultrasonic pulse velocity (UPV), using embedded low-cost and aggregate-size piezoelectric transducers, the acoustic emission (AE) and the digital image correlation (DIC) are the NDT methods which are comprehensively used. The integrated ultrasonic, acoustic and optical monitoring system introduces an experimental configuration that detects and locates the four-point bending mode fracture on large-scale concrete beams, detects the healing activation process and evaluates the subsequent concrete repair.

  10. SEM in situ MiniCantilever Beam Bending of U-10Mo/Zr/Al Fuel Elements

    Energy Technology Data Exchange (ETDEWEB)

    Mook, William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Baldwin, Jon K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Ricardo M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mara, Nathan A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-06-16

    In this work, the fracture behavior of Al/Zr and Zr/dU-10Mo interfaces was measured via the minicantilever bend technique. The energy dissipation rates were found to be approximately 3.7-5 mj/mm2 and 5.9 mj/mm2 for each interface, respectively. It was found that in order to test the Zr/U-10Mo interface, location of the hinge of the cantilever was a key parameter. While this test could be adapted to hot cell use through careful alignment fixturing and measurement of crack lengths with an optical microscope (as opposed to SEM, which was used here out of convenience), machining of the cantilevers via MiniMill in such a way as to locate the interfaces at the cantilever hinge, as well as proper placement of a femtosecond laser notch will continue to be key challenges in a hot cell environment.

  11. A method of determining bending properties of poultry long bones using beam analysis and micro-CT data.

    Science.gov (United States)

    Vaughan, Patrick E; Orth, Michael W; Haut, Roger C; Karcher, Darrin M

    2016-01-01

    While conventional mechanical testing has been regarded as a gold standard for the evaluation of bone heath in numerous studies, with recent advances in medical imaging, virtual methods of biomechanics are rapidly evolving in the human literature. The objective of the current study was to evaluate the feasibility of determining the elastic and failure properties of poultry long bones using established methods of analysis from the human literature. In order to incorporate a large range of bone sizes and densities, a small number of specimens were utilized from an ongoing study of Regmi et al. (2016) that involved humeri and tibiae from 3 groups of animals (10 from each) including aviary, enriched, and conventional housing systems. Half the animals from each group were used for 'training' that involved the development of a regression equation relating bone density and geometry to bending properties from conventional mechanical tests. The remaining specimens from each group were used for 'testing' in which the mechanical properties from conventional tests were compared to those predicted by the regression equations. Based on the regression equations, the coefficients of determination for the 'test' set of data were 0.798 for bending bone stiffness and 0.901 for the yield (or failure) moment of the bones. All regression slopes and intercepts values for the tests versus predicted plots were not significantly different from 1 and 0, respectively. The study showed the feasibility of developing future methods of virtual biomechanics for the evaluation of poultry long bones. With further development, virtual biomechanics may have utility in future in vivo studies to assess laying hen bone health over time without the need to sacrifice large groups of animals at each time point. PMID:26794840

  12. Magnetoinduction sensor of beam current with magnetic noise screening

    International Nuclear Information System (INIS)

    A description is given of a magnetoinduction sensor of beam current in a synchrotron, the latter being a booster of the VEhPP-4 electron-positron complex. The sensor operates under conditions of heavy background noise induced by the synchrotron pulsed magnetic fields. The means reducing the noise level in the sensor are considered. The most efficient screen protecting against pulsed fields is one made of conducting materials where the field is reduced at the expense of induced currents passing in a skin-layer. The screen has an azimuthal slit, which results in the beam vortex field penetration to the sensor without reduction. The noise field is reduced due to the conducting walls and deep slit. Application of the means deseribed allowed to measure low (of the order of 100 mcA) synchrotron beam currents

  13. 预应力混凝土组合箱梁扭后抗弯性能分析%Bending behavior study of prestressed composite steel-concrete box beams damaged by torsion

    Institute of Scientific and Technical Information of China (English)

    胡少伟; 胡汉林

    2011-01-01

    In order to investigate the bending behavior of the prestressed composite steel-concrete box beams which have been damaged by torsion, five composite box beams are tested by symmetrical load at mid-span. Considering the history of the torsion loading on the beams, and comparing with the test about the intact beam, by tests and analysis are given some important parameters, such as the ultimate bending capacity of the composite beams, curve of moment-deflection at mid-span and curve of the increases of strain in steel beam, and a formula for calculating the bending capacity of the beams is offered in this study. The test results show that the bending capacity of the beams which have been damaged by torsion is lower than the intact beam; the history of the torsion loading would affect the bending capacity of the beams; and the prestressing force can improve the bending capacity of the beams.%为研究预应力混凝土组合箱梁扭后的抗弯性能,进行了5根预应力组合梁的先扭后弯试验.试验在梁跨中对称荷载作用下进行,考虑试验梁受扭矩作用历史,并与完整组合梁的试验进行对比得到扭后预应力组合梁的极限抗弯承载力、跨中弯矩-挠度曲线及钢梁截面应变增长曲线,并提出了预应力组合梁扭后承载力计算公式.试验结果表明:预应力组合梁扭后承弯能力将会降低;受扭历史影响预应力组合梁的抗弯能力;预应力能够提高扭后预应力组合梁的抗弯能力.

  14. The creep and growth of Zr alloys as determined from the bending of ion irradiated cantilever beams

    International Nuclear Information System (INIS)

    Ion irradiation of Zr and Zr alloy cantilever beam specimens results in a deflection of their free end which is dependent on metallurgical structure and ion fluence. This deflection can be correlated with growth and creep measurements performed on neutron irradiated specimens. In this report, the dynamic response of an ion-irradiated cantilever beam and the eventual saturation of its deflection is described in terms of current concepts of creep and growth. The experimental technique seems capable of generating a great deal of useful information in a technologically significant area. Results are presented for Zr, Zircaloy-2, Zr-2.5 wt percent Nb and Excel cantilever beams, ion-irradiated at 314 K

  15. Experimental Investigation on Reinforced Ultra-High-Performance Fiber-Reinforced Concrete Composite Beams Subjected to Combined Bending and Shear

    OpenAIRE

    Noshiravani, Talayeh; Bruehwiler, Eugen

    2013-01-01

    An experimental study on a series of composite beams combining a 250 mm (9.84 in.) deep reinforced concrete (RC) element and a 50 mm (1.97 in.) thick reinforced ultra-high-performance fiber-reinforced concrete (R-UHPFRC) element is presented. The specimens are tested in a cantilever-beam setup with the R-UHPFRC element acting as an additional tensile reinforcement. The test parameters include the span length and the ratio and type of the steel reinforcing bars, including stirrups. Most of the...

  16. Molding the flow of electromagnetic waves and creating a mirage with a magnetic field

    Science.gov (United States)

    Chen, Shaowen; Du, Junjie; Liu, Shiyang; Lin, Zhifang; Chui, S. T.

    2008-10-01

    We demonstrate that it is possible to mold the flow of an electromagnetic (EM) beam in a magnetic photonic crystal by the application of a nonuniform external static magnetic field (ESMF). The beam bending can be understood and explained by analyzing the isofrequency (IF) curves. The effect of the ESMF on the shape and size of the IF curves enables the manipulation of the group velocity of the beam, resulting in the bending of the EM beam and creating a mirage effect.

  17. Primary Beam Steering Due to Field Leakage from Superconducting SHMS Magnets

    OpenAIRE

    Moore, Michael H.; Waidyawansa, Buddhini P.; Covrig, Silviu; Carlini, Roger; Benesch, Jay

    2014-01-01

    Simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a...

  18. Effect of bending stresses on the high-frequency magnetic properties and their time stability in a cobalt-based amorphous alloy with an extremely low magnetostriction

    Science.gov (United States)

    Kekalo, I. B.; Mogil'nikov, P. S.

    2015-12-01

    An unusual effect of the stresses of bending (toroidal sample diameter D) on the hysteretic magnetic properties ( H c , μ5) of an amorphous Co69Fe3.7Cr3.8Si12B11 alloy with an extremely low magnetostriction (|λ s | ≤ 10-7) is revealed. These properties are measured in a dynamic regime at a magnetic-field frequency f = 0.1-20 kHz. The coercive force of the alloy H c weakly depends on D at low frequencies ( f fact that magnetization reversal via the displacement of rigid domain walls is predominant at low frequencies and during static measurements and magnetization reversal via the displacement of flexible domain walls is predominant at high frequencies.

  19. Dynamic hysteretic sensing model of bending-mode Galfenol transducer

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Shuying, E-mail: shuying-cao@hebut.edu.cn; Zheng, Jiaju; Sang, Jie; Zhang, Pengfei; Wang, Bowen; Huang, Wenmei [Province-Ministry Joint Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability, Hebei University of Technology, Tianjin 300130 (China)

    2015-05-07

    A dynamic hysteretic sensing model has been developed to predict the dynamic responses of the magnetic induction, the stress, and the output voltage for a bending-mode Galfenol unimorph transducer subjected simultaneously to acceleration and bias magnetic field. This model is obtained by coupling the hysteretic Armstrong model and the structural dynamic model of the Galfenol unimorph beam. The structural dynamic model of the beam is founded based on the Euler-Bernouli beam theory, the nonlinear constitutive equations, and the Faraday law of electromagnetic induction. Comparisons between the calculated and measured results show the model can describe dynamic nonlinear voltage characteristics of the device, and can predict hysteretic behaviors between the magnetic induction and the stress. Moreover, the model can effectively analyze the effects of the bias magnetic field, the acceleration amplitude, and frequency on the root mean square voltage of the device.

  20. Dynamic hysteretic sensing model of bending-mode Galfenol transducer

    International Nuclear Information System (INIS)

    A dynamic hysteretic sensing model has been developed to predict the dynamic responses of the magnetic induction, the stress, and the output voltage for a bending-mode Galfenol unimorph transducer subjected simultaneously to acceleration and bias magnetic field. This model is obtained by coupling the hysteretic Armstrong model and the structural dynamic model of the Galfenol unimorph beam. The structural dynamic model of the beam is founded based on the Euler-Bernouli beam theory, the nonlinear constitutive equations, and the Faraday law of electromagnetic induction. Comparisons between the calculated and measured results show the model can describe dynamic nonlinear voltage characteristics of the device, and can predict hysteretic behaviors between the magnetic induction and the stress. Moreover, the model can effectively analyze the effects of the bias magnetic field, the acceleration amplitude, and frequency on the root mean square voltage of the device

  1. Bending of geometrically nonlinear cantilever beam. Results obtained by Cosserat – Timoshenko and Kirchhoff’s rod theories

    OpenAIRE

    V.V. Lalin; M.O. Beliaev

    2015-01-01

    The problem of verification of different program suites for structural analysis has recently become an important component of the construction science. One of the most extensively used benchmark problem is a classical geometrically nonlinear problem of deflection of the cantilever beam of linear elastic material, under the action of external vertical concentrated load at the free end. In fact, the solution for Kirchhoff’s rod is used as an analytical result. This rod is inextensible and ...

  2. Construction of Superconducting Magnet System for the J-PARC Neutrino Beam Line

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, T.; Wanderer, P.; Sasaki, K.; Ajima, Y.; Araoka, O.; Fujii, Y.; Hastings, N.; Higashi, N.; Iida, M.; Ishii, T.; Kimura, N.; Kobayashi, T.; Makida, Y.; Nakadaira, T.; Ogitsu, T.; Ohhata, H.; Okamura, T.; Sakashita, K.; Sugawara, S.; Suzuki, S.; Tanaka, K.; Tomaru, T.; Terashima, A.; Yamamoto, A.; Ichikawa, A.; Kakuno, H.; Anerella, M.; Escallier, J.; Ganetis, G.; gupta, R.; Jain, A.; Muratore, J.; Parker, B.; Boussuge, T.; Charrier, J.-P.; Arakawa, M.; Ichihara, T.; Minato, T.; Okada, Y.; Itou, A.; Kumaki, T.; Nagami, M.; Takahashi, T.

    2009-10-18

    Following success of a prototype R&D, construction of a superconducting magnet system for J-PARC neutrino beam line has been carried out since 2005. A new conceptual beam line with the superconducting combined function magnets demonstrated the successful beam transport to the neutrino production target.

  3. Atomic-Beam Magnetic Resonance Experiments at ISOLDE

    CERN Multimedia

    2002-01-01

    The aim of the atomic-beam magnetic resonance (ABMR) experiments at ISOLDE is to map the nuclear behaviour in wide regions of the nuclear chart by measuring nuclear spins and moments of ground and isomeric states. This is made through an investigation of the atomic hyperfine structure of free, neutral atoms in a thermal atomic-beam using radio-frequency techniques. On-line operation allows the study of short-lived nuclei far from the region of beta-stability.\\\\ \\\\ The ABMR experiments on the |2S^1 ^2 elements Rb, Cs, Au and Fr have been completed, and present efforts are directed towards the elements with an open p-shell and on the rare-earth elements.\\\\ \\\\ The experimental data obtained are compared with results from model calculations, giving information on the single-particle structure and on the nuclear shape parameters.

  4. Integration of RFQ beam coolers and solenoidal magnetic fields

    Science.gov (United States)

    Cavenago, M.; Romé, M.; Maggiore, M.; Porcellato, A. M.; Maero, G.; Chiurlotto, F.; Comunian, M.; Galatà, A.; Cavaliere, F.

    2016-02-01

    Electromagnetic traps are a flexible and powerful method of controlling particle beams, possibly of exotic nuclei, with cooling (of energy spread and transverse oscillations) provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). A RFQC prototype can be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component Bz up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by Bz and the rf voltage Vrf (up to 1 kV at few MHz). Transport is provided by a static electric field Ez (order of 100 V/m), while gas collisions (say He at 1 Pa, to be maintained by differential pumping) provide cooling or heating depending on Vrf. The beamline design and the major parameters Vrf, Bz (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup.

  5. Understanding the focusing of charged particle for 2D sheet beam in a cusped magnetic field

    CERN Document Server

    Banerjee, Tusharika S; Reddy, K T V

    2016-01-01

    The requirement of axial magnetic field for focusing and transportation of sheet beam using cusped magnets is less as compared to solenoid magnetic fields which is uniform. There is often some confusion about how a cusped magnetic field focuses high current density sheet beam because it is generally understood that non-uniform magnetic field cannot guide the particle beam along its axis of propagation .In this paper, we perform simple analysis of the dynamics of sheet beam in a cusped magnetic field with single electron model and emphasize an intuitive understanding of interesting features (as beam geometry, positioning of permanent magnets, particle radius,particle velocity,radius of curvature of particle inside cusped magnetic field)

  6. Beam heating studies on an early model is a superconducting cosine theta magnet

    Energy Technology Data Exchange (ETDEWEB)

    Bozoki, G; Bunce, G; Danby, G; Foelsche, H; Jackson, J; Prodell, A; Soukas, A; Stevens, A; Stoehr, R; Weisenbloom, J

    1980-01-01

    Superconducting magnets for accelerators can be accidentally quenched by heat resulting from beam losses in the magnet. The threshold for such quenches is determined by the time structure of the beam loss and by details of the magnet application, construction and cooling. A 4.25 m long superconducting cosine theta dipole magnet, MARK VI, constructed during the research and development phase of the ISABELLE Project at BNL was installed in the 28.5 GeV/c primary proton beam line from the AGS. By energizing the magnet, the proton beam could be deflected into the magnet. The beam intensity required to quench the magnet was observed for different beam sizes and at several values of magnet current up to 2400 A or approximately 70% of the highest magnet operating current. The maximum current was limited by the gas-cooled power lead flow available using pool-boiling helium rather than single phase forced-flow helium at 5 atm for which the magnet system was designed. Details of the experimental setup including the magnet and cryogenic system, the beam-monitoring equipment and instrumentation are described. The measurements are discussed and compared with beam heating measurements made on another superconducting magnet and interpreted using the Cascade Simulation Program, CASIM.

  7. Intense ion beam applications to magnetic confinement fusion

    International Nuclear Information System (INIS)

    The ion ring project objective is to trap a ring of high energy, axis-encircling ions in a magnetic mirror. The number of ring ions should be such as to produce deltaB/B on the ring axis of order 10%. The second experiment, LONGSHOT, is directed to producing a long pulse ion beam source so that the total number of protons required for an ion ring can be provided a lower diode power and, hence, at much less cost than that of 100 nsec pulsed power generators like the NRL GAMBLE II. A detailed report of the progress on IREX and LONGSHOT is given

  8. Stress Measurement around a Circular Role in a Cantilever Beam under Bending Moment Using Strain Gage and Reflective Photoelasticity

    International Nuclear Information System (INIS)

    It is necessary to study on the stress concentration experimentally, which is the main reason to avoid mechanical dilapidation and failure, when designing a mechanical structure. Stress concentration factor of a specimen of cantilever beam with a circular hole in the center was measured using both strain gage and photoelastic methods in this paper. In strain-gage measurement, three strain gages along the line near a hole of the specimen were installed and maximum strain was extrapolated from three measurements. In photoelastic measurement, two methods were employed. First, the Babinet-Soleil compensation method was used to measure the maximum strain. Secondly, photoelastic 4-step phase shilling method was applied to observe the strain distribution around the hole. Measurements obtained by different experiments were comparable within the range of experimental error

  9. Magnetic field measurements of superconducting magnets for the colliding beam accelerator

    International Nuclear Information System (INIS)

    An important aspect of the development and production of superconducting magnets for the Colliding Beam Accelerator is the measurement of the magnetic field in the aperture of these magnets. The measurements have the three-fold purpose of determining the field quality as compared to the lattice requirements of the CBA, of obtaining the survey data necessary to position the magnets in the CBA tunnel, and lastly, of characterizing the magnetic fields for use in initial and future orbit studies of the CBA proton beams. Since for a superconducting storage accelerator it is necessary to carry out these detailed measurements on many (approx. 1000) magnets and at many current values (approx. 1000), we have chosen, in agreement with previous experience, to develop a system which Fourier analyses the voltages induced in a number of rotating windings and thereby obtains the multipole field components. The important point is that such a measuring system can be fast and precise. It has been used for horizontal measurements of the CBA ring dipoles

  10. Superconducting Magnetic Shield of the Beam Vacuum Chamber for ALICE Muon Spectrometer

    CERN Document Server

    Shishov, Yu A; CERN. Geneva; Tsvineva, A G

    1997-01-01

    The operation of the dipole magnet of the ALICE muon spectrometer will require the ramping of the magnetic field in it according to the acceleration of the LHC beam. For the superconducting dipole magnet the ramping of the field will complicate the design of the magnet. To avoid the ramping of the magnetic field in the dipole magnet we propose to shield the LHC vacuum chamber inside of the dipole by the superconducting magnetic shield.

  11. Focused Azimuthally E-Polarized Vector Beam and Spatial Magnetic Resolution below the Diffraction Limit

    OpenAIRE

    Veysi, Mehdi; Guclu, Caner; Capolino, Filippo

    2016-01-01

    An azimuthally E-polarized vector beam (AEVB) has a salient feature that it contains a magnetic-dominant region within which electric field has a null and longitudinal magnetic field is maximum. Fresnel diffraction theory and plane-wave spectral (PWS) calculations are applied to quantify the field features of such a beam upon focusing through a lens. The diffraction-limited full width at half maximum (FWHM) of the beams longitudinal magnetic field intensity profile and complementary FWHM (CFW...

  12. Design, simulation and construction of quadrupole magnets for focusing electron beam in powerful industrial electron accelerator

    Directory of Open Access Journals (Sweden)

    S KH Mousavi

    2015-09-01

    Full Text Available In this paper the design and simulation of quadrupole magnets and electron beam optical of that by CST Studio code has been studied. Based on simulation result the magnetic quadrupole has been done for using in beam line of first Iranian powerful electron accelerator. For making the suitable magnetic field the effects of material and core geometry and coils current variation on quadrupole magnetic field have been studied. For test of quadrupole magnet the 10 MeV beam energy and 0.5 pi mm mrad emittance of input beam has been considered. We see the electron beam through the quadrupole magnet focus in one side and defocus in other side. The optimum of distance between two quadrupole magnets for low emittance have been achieved. The simulation results have good agreement with experimental results

  13. Primary beam steering due to field leakage from superconducting SHMS magnets

    International Nuclear Information System (INIS)

    In this study, simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line

  14. Primary beam steering due to field leakage from superconducting SHMS magnets

    International Nuclear Information System (INIS)

    Simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line

  15. Primary Beam Steering Due to Field Leakage from Superconducting SHMS Magnets

    CERN Document Server

    Moore, Michael H; Covrig, Silviu; Carlinin, Roger; Benesch, Jay

    2014-01-01

    Simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line.

  16. Beam optics of a dipole magnet for energy measurement in an RF linac

    International Nuclear Information System (INIS)

    This paper presents the analytical calculation and simulation for the beam optics study of a 30° sector magnet. This sector magnet will be used to measure the energy of a 1.5 MeV electron beam being injected from an RF linac. From initial beam parameters, arc length of the magnet and number of ampere-turns have been optimised. To find out beam size, Transfer matrix method is used for different initial beam conditions. A program is written in MATHEMATICA to solve the envelope equation in both dispersive and non-dispersive plane . To validate this program, simulation is carried out in the software CST PARTICLE STUDIO. (author)

  17. A new approach for elasto-plastic finite strain analysis of cantilever beams subjected to uniform bending moment

    Indian Academy of Sciences (India)

    GOKHAN T TAYYAR

    2016-04-01

    The reliability and limits of solutions for static structural analysis depend on the accuracy of the curvature and deflection calculations. Even if the material model is close to the actual material behavior, physically unrealistic deflections or divergence problems are unavoidable in the analysis if an appropriate fundamental kinematic theory is not chosen. Moreover, accurate deflection calculation plays an important role in ultimate strength analysis where in-plane stresses are considered. Therefore, a more powerful method is neededto achieve reliable deflection calculation and modeling. For this purpose, a new advanced step was developed by coupling the elasto-plastic material behavior with precise general planar kinematic analysis. The deflection is generated precisely without making geometric assumptions or using differential equations of the deflection curve. An analytical finite strain solution was derived for an elasto-plastic prismatic/non-prismatic rectangular cross-sectioned beam under a uniform moment distribution. A comparison of the analytical results with thosefrom the Abaqus FEM software package reveals a coherent correlation.

  18. Liquid-metal-cooled, curved-crystal monochromator for Advanced Photon Source bending-magnet beamline 1-BM

    International Nuclear Information System (INIS)

    The authors describe a horizontally focusing curved-crystal monochromator that invokes a 4-point bending scheme and a liquid-metal cooling bath. The device has been designed for dispersive diffraction and spectroscopy in the 5--20 keV range, with a predicted focal spot size of ≤ 100 microm. To minimize thermal distortions and thermal equilibration time, the 355 x 32 x 0.8 mm crystal will be nearly half submerged in a bath of Ga-In-Sn-Zn alloy. The liquid metal thermally couples the crystal to the water-cooled Cu frame, while permitting the required crystal bending. Calculated thermal profiles and anticipated focusing properties are discussed

  19. Design, simulation and construction of quadrupole magnets for focusing electron beam in powerful industrial electron accelerator

    OpenAIRE

    S KH Mousavi; A M Poursaleh; S Haseltalab; M Mortazavi; A Behjat; Atefi, M.

    2015-01-01

    In this paper the design and simulation of quadrupole magnets and electron beam optical of that by CST Studio code has been studied. Based on simulation result the magnetic quadrupole has been done for using in beam line of first Iranian powerful electron accelerator. For making the suitable magnetic field the effects of material and core geometry and coils current variation on quadrupole magnetic field have been studied. For test of quadrupole magnet the 10 MeV beam energy and 0.5 pi mm...

  20. Generation of Vortex Beams with Strong Longitudinally Polarized Magnetic Field by Using a Metasurface

    CERN Document Server

    Veysi, Mehdi; Capolino, Filippo

    2014-01-01

    A novel method of generation and synthesis of azimuthally E-polarized vortex beams is presented. Along the axis of propagation such beams have a strong longitudinally polarized magnetic field where ideally there is no electric field. We show how these beams can be constructed through the interference of Laguerre-Gaussian beams carrying orbital angular momentum. As an example, we present a metasurface made of double-split ring slot pairs and report a good agreement between simulated and analytical results. Both a high magnetic-to-electric-field contrast ratio and a magnetic field enhancement are achieved. We also investigate the metasurface physical constraints to convert a linearly polarized beam into an azimuthally E- polarized beam and characterize the performance of magnetic field enhancement and electric field suppression of a realistic metasurface. These findings are potentially useful for novel optical spectroscopy related to magnetic dipolar transitions and for optical manipulation of particles with sp...

  1. New magnet transport system for the LHC beam transfer lines

    CERN Document Server

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system (pictured here in one of the tunnels) is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The lead vehicle is powered by an electric rail set into the roof of the tunnel. The system is backed up by electrical batteries that enable it to operate in the absence of an outside power source or in the event of power failure. Last but not least, for the long-distance transport of magnets, it can be optically guided by a line traced on the tunnel floor. The convoy moves through the particularly narr...

  2. Study of Magnetic Vibration Absorber with Permanent Magnets along Vibrating Beam Structure

    OpenAIRE

    F. B. Sayyad; Gadhave, N. D.

    2013-01-01

    The vibration absorbers are frequently used to control and minimize excess vibration in structural system. Dynamic vibration absorbers are used to reduce the undesirable vibration in many applications such as pumps, gas turbines, engine, bridge, and electrical generator. To reduce the vibration of the system, the frequency of absorber should be equal to the excitation frequency. The aim of this study is to investigate the effect of magnetic vibration absorber along vibrating cantilever beam. ...

  3. Generation and Characterization of Magnetized Bunched Electron Beam from a DC High Voltage Photogun

    Science.gov (United States)

    Suleiman, Riad; Poelker, Matthew; Benesch, Jay; Hannon, Fay; Hernandez-Garcia, Carlos; Wang, Yan

    2016-03-01

    To maintain ion beam emittance and extend luminosity lifetime, the Jefferson Lab design of the Electron Ion Collider includes a bunched magnetized electron beam cooler as part of the Collider Ring. We are building a prototype magnetized gun using our newly commissioned 325 kV inverted-insulator DC high voltage photogun. This contribution describes planned measurements of beam magnetization as a function of bunch charge and average current, and laser beam size and magnetic field strength at the photocathode. Results will be compared to particle tracking code simulations. Photocathode lifetime at milli-ampere current will be compared to beam lifetime with no magnetization, to explore the impact of the magnetic field on photogun operation. Combined, these measurements and simulations will benchmark our design tools and provide insights on ways to optimize the electron cooler. This work is supported by the Department of Energy, Laboratory Directed Research and Development funding, under contract DE-AC05-06OR23177.

  4. Characteristics for beam focusing of a magnetically insulated diode with a toroidal magnetic field (TMID)

    International Nuclear Information System (INIS)

    For the purpose of focusing intense pulsed ion beams, an ion diode insulated for electrons with a toroidal magnetic field (TMID) has been designed and tested as a preliminary experiment. The annular diode assembly is contained in the toroidal field produced with a toroidal coil. The diode power was supplied from a pulsed power supply ''ERIDATRON-II'' at a stored energy of 5kJ. Ion beams of 10 - 20kA with energies of 250 - 350 keV have been produced with an efficiency of about 10 %. It is suggested from observations of circulating current around the anode in nearly E x B direction, that the diode efficiency will be enhanced by increasing the toroidal field strength much above the critical magnetic field for insulation. The measured ion orbits agree well with the calculated single-particle ion orbits in this field even when the conditions for cross-field propagation are satisfied. The toroidal field was found to act as a magnetic lens as well as the insulating field for electrons in the diode. The features of the TMID appear to be very useful for obtaining a well focused ion beam in a simple device. (author)

  5. Electron gun for a multiple beam klystron with magnetic compression of the electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Ives, R. Lawrence; Tran, Hien T; Bui, Thuc; Attarian, Adam; Tallis, William; David, John; Forstall, Virginia; Andujar, Cynthia; Blach, Noah T; Brown, David B; Gadson, Sean E; Kiley, Erin M; Read, Michael

    2013-10-01

    A multi-beam electron gun provides a plurality N of cathode assemblies comprising a cathode, anode, and focus electrode, each cathode assembly having a local cathode axis and also a central cathode point defined by the intersection of the local cathode axis with the emitting surface of the cathode. Each cathode is arranged with its central point positioned in a plane orthogonal to a device central axis, with each cathode central point an equal distance from the device axis and with an included angle of 360/N between each cathode central point. The local axis of each cathode has a cathode divergence angle with respect to the central axis which is set such that the diverging magnetic field from a solenoidal coil is less than 5 degrees with respect to the projection of the local cathode axis onto a cathode reference plane formed by the device axis and the central cathode point, and the local axis of each cathode is also set such that the angle formed between the cathode reference plane and the local cathode axis results in minimum spiraling in the path of the electron beams in a homogenous magnetic field region of the solenoidal field generator.

  6. Stress-anneal-induced magnetic anisotropy in highly textured Fe-Ga and Fe-Al magnetostrictive strips for bending-mode vibrational energy harvesters

    Science.gov (United States)

    Park, Jung Jin; Na, Suok-Min; Raghunath, Ganesh; Flatau, Alison B.

    2016-05-01

    Magnetostrictive Fe-Ga and Fe-Al alloys are promising materials for use in bending-mode vibrational energy harvesters. For this study, 50.8 mm × 5.0 mm × 0.5 mm strips of Fe-Ga and Fe-Al were cut from 0.50-mm thick rolled sheet. An atmospheric anneal was used to develop a Goss texture through an abnormal grain growth process. The anneal lead to large (011) grains that covered over 90% of sample surface area. The resulting highly-textured Fe-Ga and Fe-Al strips exhibited saturation magnetostriction values (λsat = λ∥ - λ⊥) of ˜280 ppm and ˜130 ppm, respectively. To maximize 90° rotation of magnetic moments during bending of the strips, we employed compressive stress annealing (SA). Samples were heated to 500°C, and a 100-150 MPa compressive stress was applied while at 500°C for 30 minutes and while being cooled. The effectiveness of the SA on magnetic moment rotation was inferred by comparing post-SA magnetostriction with the maximum possible yield of rotated magnetic moments, which is achieved when λ∥ = λsat and λ⊥ = 0. The uniformity of the SA along the sample length and the impact of the SA on sensing/energy harvesting performance were then assessed by comparing pre- and post-SA bending-stress-induced changes in magnetization at five different locations along the samples. The SA process with a 150 MPa compressive load improved Fe-Ga actuation along the sample length from 170 to 225 ppm (from ˜60% to within ˜80% of λsat). The corresponding sensing/energy harvesting performance improved by as much as a factor of eight in the best sample, however the improvement was not at all uniform along the sample length. The SA process with a 100 MPa compressive load improved Fe-Al actuation along the sample length from 60 to 73 ppm (from ˜46% to ˜56% of λsat, indicating only a marginally effective SA and suggesting the need for modification of the SA protocol. In spite of this, the SA was effective at improving the sensing/energy harvesting

  7. Stress-anneal-induced magnetic anisotropy in highly textured Fe-Ga and Fe-Al magnetostrictive strips for bending-mode vibrational energy harvesters

    Directory of Open Access Journals (Sweden)

    Jung Jin Park

    2016-05-01

    Full Text Available Magnetostrictive Fe-Ga and Fe-Al alloys are promising materials for use in bending-mode vibrational energy harvesters. For this study, 50.8 mm × 5.0 mm × 0.5 mm strips of Fe-Ga and Fe-Al were cut from 0.50-mm thick rolled sheet. An atmospheric anneal was used to develop a Goss texture through an abnormal grain growth process. The anneal lead to large (011 grains that covered over 90% of sample surface area. The resulting highly-textured Fe-Ga and Fe-Al strips exhibited saturation magnetostriction values (λsat =  λ∥ − λ⊥ of ∼280 ppm and ∼130 ppm, respectively. To maximize 90° rotation of magnetic moments during bending of the strips, we employed compressive stress annealing (SA. Samples were heated to 500°C, and a 100-150 MPa compressive stress was applied while at 500°C for 30 minutes and while being cooled. The effectiveness of the SA on magnetic moment rotation was inferred by comparing post-SA magnetostriction with the maximum possible yield of rotated magnetic moments, which is achieved when λ∥ = λsat and λ⊥ = 0. The uniformity of the SA along the sample length and the impact of the SA on sensing/energy harvesting performance were then assessed by comparing pre- and post-SA bending-stress-induced changes in magnetization at five different locations along the samples. The SA process with a 150 MPa compressive load improved Fe-Ga actuation along the sample length from 170 to 225 ppm (from ∼60% to within ∼80% of λsat. The corresponding sensing/energy harvesting performance improved by as much as a factor of eight in the best sample, however the improvement was not at all uniform along the sample length. The SA process with a 100 MPa compressive load improved Fe-Al actuation along the sample length from 60 to 73 ppm (from ∼46% to ∼56% of λsat, indicating only a marginally effective SA and suggesting the need for modification of the SA protocol. In spite of this, the SA was effective at improving the sensing

  8. Electron entanglement in Cooper pair beam splitter with magnetic fields

    International Nuclear Information System (INIS)

    We develop a theory that suggests the efficient manipulation of entangled electrons provided by a Cooper pair beam splitter. The splitting of coherent electrons forming a spin singlet is present if the superconductor is tunnel coupled to a double quantum dot. In order to probe entanglement, we allow for an inhomogeneous and, in general, non-collinear magnetic field. If the DQD-SC system is embedded in a transport setup, non-local current and noise properties are obtained within the real-time diagrammatic method. As a small parameter we use the hybridization between splitter and normal leads. The tunnel coupling to the superconductor is taken into account non-perturbatively. Furthermore, we provide a detailed investigation of the violation of Bell's inequality for various parameter regimes.

  9. Propagation of a nonrelativistic electron beam in a plasma in a magnetic field

    International Nuclear Information System (INIS)

    Propagation of a nonrelativistic electron beam in a plasma in a strong magnetic field has been studied using electrostatic one-dimensional particle simulation models. Electron beams of finite pulse length and of continuous injection are followed in time to study the effects of beam-plasma interaction on the beam propagation. For the case of pulsed beam propagation, it is found that the beam distribution rapidly spreads in velocity space generating a plateaulike distribution with a high energy tail extending beyond the initial beam velocity

  10. Investigation of diluted magnetic semiconductor and nano magnetic material by ion beam technology

    International Nuclear Information System (INIS)

    In this paper, we focus on constitution, magnetism modification and characterization of GaN-based materials using ion beam technology and formation of the nano structure by implanting Mn+ or Co+ ion of different doses into the film samples. SQUID and AGM were used to measure the magnetic properties, such as coercivity and saturation magnetization, for the samples before and after annealing, M-H and M-T curves showed ferromagnetism in the films at both low temperature and room temperature. RBS/C, PIXE and XRD were used to analyze the microstructure, content of doping transition metal and damage. The nano-cluster of ferromagnetism particle was observed under HRTEM. (authors)

  11. 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)

  12. Integration of RFQ beam coolers and solenoidal magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Cavenago, M., E-mail: cavenago@lnl.infn.it; Maggiore, M.; Porcellato, A. M.; Chiurlotto, F.; Comunian, M.; Galatà, A. [INFN-LNL, viale dell’Universitá n.2, 35020 Legnaro (PD) (Italy); Romé, M.; Maero, G.; Cavaliere, F. [INFN-Sezione di Milano and Physics Department, University of Milano, Milano (Italy)

    2016-02-15

    Electromagnetic traps are a flexible and powerful method of controlling particle beams, possibly of exotic nuclei, with cooling (of energy spread and transverse oscillations) provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). A RFQC prototype can be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component B{sub z} up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by B{sub z} and the rf voltage V{sub rf} (up to 1 kV at few MHz). Transport is provided by a static electric field E{sub z} (order of 100 V/m), while gas collisions (say He at 1 Pa, to be maintained by differential pumping) provide cooling or heating depending on V{sub rf}. The beamline design and the major parameters V{sub rf}, B{sub z} (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup.

  13. Beam position measurements of Indus-2 using X-Ray beam position monitor

    International Nuclear Information System (INIS)

    A staggered pair metal blade X-ray beam position monitor (XBPM) is designed, fabricated and commissioned on Indus-2 bending magnet front end. Calibration of XBPM is done by scanning the metal blades in the path of synchrotron radiation and by giving controlled electron asymmetric bump. The vertical beam position stability of the source measured during various injections and storages are reported.

  14. Effect of bending pattern on finger joint bending strength

    Directory of Open Access Journals (Sweden)

    Džinčić Igor

    2012-01-01

    Full Text Available Limited information is available on end gluing hardwoods in contrast to softwoods, which have been extensively investigated. The objective of this study was to examine the influence of bending patern on bending strength of finger jointed beech wood. In structural uses finger jointing is finally the major method to end joint timber for the production of glue-laminated elements. There are no bending strength experimental results for finger-jointed hardwoods for investigations conducted in Serbia. Two finger jointed profiles were studied in accordance with DIN68140. The finger joints were made by side and by face of beam. Length jointed samples were loaded at the side and in the face. The obtained results led to the conclusion that the direction of load, gluing surface and the position of joint influence on the strength of continued longitudinal beams.

  15. Simulation of ion beam losses in LHC magnets

    CERN Document Server

    Bruce, R; Jowett, John M; Riklund, R

    2005-01-01

    At the particle physics laboratory CERN, the largest accelerator ever, the Large Hadron Collider (LHC), is under construction. In the LHC ultra relativistic particles, mainly protons but also lead ions, will be brought into collision. One problem that arises in the operation is that colliding ion beams in the machine have a very large cross section for electromagnetic interactions, in particular Bound Free Pair Production (BFPP). An electron-positron pair is created by the electromagnetic field between two colliding particles and the electron is created in a bound state of one of the ions. Because of this reaction the ion changes its charge and therefore leaves the wanted trajectory and crashes in a superconducting magnet, depositing heat. The impact of the wrongly charged ions on the inside of the vacuum pipe was simulated with the simulation program FLUKA. It was concluded that it is not likely that enough heat is deposited in the coils of the superconducting magnet to induce a quench, although some uncerta...

  16. Thermal analysis of the beam missteering in APS storage ring

    International Nuclear Information System (INIS)

    Several bending magnet beam missteering cases have been investigated for the 7-GeV storage ring of the Advanced Photon Source (APS). One of the critical missteering events is presented in this paper. Finite element analyses are performed to solve for both temperature and stress fields. Thermally induced deflections are determined by using beam bending theory. A safe current limit is established for the storage ring chambers

  17. High-current relativistic electron beam shaping in a coaxial diode with magnetic insulation

    International Nuclear Information System (INIS)

    Solution of the problem of relativistic electron beam (REB) for the system with a constant transverse cross-section and thin-wall tubular cathode in an arbitrary magnetic field is presented. The total equation system determining REB parameters as a function of external longitudinal magnetic field is obtained on the base on the laws of conservation of impulse flow and momentum of electron impulse and fields (electrical and magnetic) under the assumption of the electron beam. Calculation results carried out with provision for a diamagnetism and screening of the beam impulse magnetic field by metal are in a good agreement with experimental data

  18. Injection line of 1+ ion beam for electron beam ion-charge breeding source and related beam elements

    International Nuclear Information System (INIS)

    Main purpose of the electron beam ion-charge breeding source (EBIBS) is to produce highly pure and highly charged ion beam from single charge ion of stable or radioactive species. It can accept low emittance ion beam from either online or offline ECR ion sources (ECRIS). The emittance of the extracted beam is low at lower RF frequencies and magnetic field of the ECRIS. The beam at the position of extraction is approximately reproduced at the entrance of the electron collector of the EBIBS. The beam moves forward under the influence of the negative potential deep of the electron beam and enters the ionization region in solenoid field of the EBIBS. The injection line starts at the extraction region of the ECRIS. The assumed parameters of the extracted beam of 20 keV energy and 0.0732 GeV/c momentum for injection are 10 mm diameter and 30 mrad beam divergence cone. As mass number of the ions decreases the energy decreases for constant momentum of the ion beam. The value of the momentum or the beam rigidity is judiciously chosen to encompass the most of the isotopes of various elements. The beam is focused by a quadrupole doublet and passes the beam through a 90° bending magnet. The beam is analyzed also by the dipole magnet to remove the contaminants and the selected ion beam is focused by a quadrupole doublet magnet to pass through an electrostatic 90° bending elements. The beam approaches the opening of 16 mm diameter of the electron collector. A round beam of 12 mm diameter is achieved here with the help of a quadrupole triplet through point-to-point imaging from start to the end. The transport matrices for the electrostatic bending elements were calculated and incorporated into the TRANSPORT code. (author)

  19. CFRP板加固受弯钢梁的承载力及挠度分析%Bearing Capacity and Deflection Analysis of Bending Steel Beams Strengthened with CFRP Plates

    Institute of Scientific and Technical Information of China (English)

    张鹏; 叶黎明; 邓朗妮; 钟鑫

    2011-01-01

    采用截面等效代换法,对碳纤维板加固受弯钢梁进行了承载力及挠度分析,推导出CFRP板加固受弯钢梁的理论计算公式.为验证公式,进行了5根CFRP板加固钢梁的单调静力试验,并用有限元软件进行模拟分析,将计算结果分别与试验结果和有限元分析结果进行比较后发现:弯矩理论计算值比试验值略小,挠度理论计算值比试验值略大,且都与有限元模拟值相近,说明理论计算安全,计算方法具有良好的适用性.%The method of using one section to exchange another is used to study bearing capacity and deflection analysis of bending steel beams strengthened with carbon fiber-reinforced polymer (CFRP) plates. The theoretical formula of bending steel reinforced beams is worked out. Five reinforced beams are used in the monotonic static experiment for validating the formula. Finite element software is applied to simulate and analyze the strengthened beams. The calculation result is compared with the experiment and finite element simulation results and analyzed. The calculated value is less than experimental value of bending moment while the calculated value is bigger than experimental value of deflection. Both calculated values are approaching to the simulation results. It shows that the calculating is safe and the calculating method has good applicability. The formula can be used as reference in the project of designing steel beams reinforced by CFRP plates.

  20. Generation of Vortex Beams with Strong Longitudinally Polarized Magnetic Field by Using a Metasurface

    OpenAIRE

    Veysi, Mehdi; Guclu, Caner; Capolino, Filippo

    2014-01-01

    A novel method of generation and synthesis of azimuthally E-polarized vortex beams is presented. Along the axis of propagation such beams have a strong longitudinally polarized magnetic field where ideally there is no electric field. We show how these beams can be constructed through the interference of Laguerre-Gaussian beams carrying orbital angular momentum. As an example, we present a metasurface made of double-split ring slot pairs and report a good agreement between simulated and analyt...

  1. Investigation of effect of solenoid magnet on emittances of ion beam from laser ablation plasma

    International Nuclear Information System (INIS)

    A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ion beams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface

  2. Investigation of effect of solenoid magnet on emittances of ion beam from laser ablation plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Shunsuke, E-mail: shunsuke.ikeda@riken.jp; Sekine, Megumi [Tokyo Institute of Technology, Yokohama, Kanagawa (Japan); Riken, Wako, Saitama (Japan); Romanelli, Mark [Cornell University, Ithaca, New York 14850 (United States); Cinquegrani, David [University of Michigan, Ann Arbor, Michigan 48109 (United States); Kumaki, Masafumi [Waseda University, Shinjuku, Tokyo (Japan); Fuwa, Yasuhiro [Kyoto University, Uji, Kyoto (Japan); Kanesue, Takeshi; Okamura, Masahiro [Brookhaven National Laboratory, Upton, New York 11973 (United States); Horioka, Kazuhiko [Tokyo Institute of Technology, Yokohama, Kanagawa (Japan)

    2014-02-15

    A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ion beams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface.

  3. Study of pulsed sextupole magnet system for beam injection at UVSOR

    International Nuclear Information System (INIS)

    In order to introduce Pulsed Sextupole Magnet (PSM) injection at UVSOR, we performed simulation of the injection beam, and design of PSM. This PSM was designed to excite a stronger magnetic field by making a gap small. And the simulation was performed using designed PSM. As a result, it revealed that beam injection was sufficiently possible using this PSM at UVSOR, but injected beam must feel magnetic field for several turns by the PSM because of short revolution period of the storage ring. We have measured a magnetic field of this PSM which was completed in this Spring and evaluated the performance of it. A magnetic field remains in a center in PSM because of manufacturing error. So it is necessary that the magnetic field of center is rectified. We considered the method of rectifying the magnetic field of center using a thin ferrite, and confirmed effect of this method. (author)

  4. Investigation of effect of solenoid magnet on emittances of ion beam from laser ablation plasma

    Science.gov (United States)

    Ikeda, Shunsuke; Romanelli, Mark; Cinquegrani, David; Sekine, Megumi; Kumaki, Masafumi; Fuwa, Yasuhiro; Kanesue, Takeshi; Okamura, Masahiro; Horioka, Kazuhiko

    2014-02-01

    A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ion beams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface.

  5. Measurements of emittance growth through the achromatic bend at the BNL Accelerator Test Facility

    International Nuclear Information System (INIS)

    Measurements of emittance growth in a high peak current beam as it passes through an achromatic double bend are summarized. Experiments were performed using the ATF at Brookhaven National Laboratory by X.J. Wang and D. Kehne as a collaboration resulting from the proposal attached at the end of the document. The ATF consists off an RF gun (1 MeV), two sections of linac (40-75 MeV), a diagnostic section immediately following the linac, a 20 degree bend magnet, a variable aperture slit at a high dispersion point, 5 quadrupoles, then another 20 degree bend followed by another diagnostic section. The TRANSPORT deck describing the region from the end of the linac to the end of the diagnostic line following the achromatic bends is attached to the end of this document. Printouts of the control screens are also attached

  6. Simulation of the magnetic mirror effect on a beam of positrons

    CERN Document Server

    Boursette, Delphine

    2014-01-01

    I simulated a beam of positrons at the entrance of a 5 Tesla magnet for the Aegis experiment. The goal was to show how many positrons are lost because of the magnetic mirror effect. To do my simulation, I used Comsol to create the magnetic field map and Geant4 to draw the trajectories of the positrons in this field map.

  7. A steering magnet optimized by random search method for high current beam transport line

    International Nuclear Information System (INIS)

    We present an improved design of the steering magnet which produces almost uniform magnetic field in the region through which beam passes. Optimization of the parameters of the steering magnet is done by random search method. It is shown that use of a suitable shim reduces the field deviation by a great extent. (author)

  8. Calculation of the transverse kicks generated by the bends of a hollow electron lens

    CERN Document Server

    Stancari, Giulio

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam in high-energy accelerators. They were used in the Fermilab Tevatron collider for abort-gap clearing, beam-beam compensation, and halo scraping. A beam-beam compensation scheme based upon electron lenses is currently being implemented in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. This work is in support of a conceptual design of hollow electron beam scraper for the Large Hadron Collider. It also applies to the implementation of nonlinear integrable optics with electron lenses in the Integrable Optics Test Accelerator at Fermilab. We consider the axial asymmetries of the electron beam caused by the bends that are used to inject electrons into the interaction region and to extract them. A distribution of electron macroparticles is deposited on a discrete grid enclosed in a conducting pipe. The electrostatic potential and electri...

  9. Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

    International Nuclear Information System (INIS)

    The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam

  10. Design and Construction of Solenoid Magnetic Lens for Focusing Electron Beam from Thermionic Electron Gun

    International Nuclear Information System (INIS)

    Electron gun is an important part of an electron accelerator for producing electron beam to be irradiated on material. The electron gun of electron accelerator constructed at P3TM BATAN, is a thermionic electron gun, A solenoid magnetic lens had been designed and constructed for focusing electron beam extracted from the electron gun in such away that all of the electron beam enter the accelerating tube. Technical specification of the solenoid magnetic lens is given in this paper. Measurement of magnetic field generated by solenoid coil shows that the largest magnetic field is in the middle of the solenoid coil. The test using the thermionic electron gun shows the focusing effect on electron beam by the solenoid magnetic lens. The focus strength is maximum after the coil current reaches 9 A. (author)

  11. Experimental and numerical studies of sheet electron beam propagation through a planar wiggler magnet

    International Nuclear Information System (INIS)

    Detailed experimental studies on sheet relativistic electron beam propagation through a long planar wiggler are reported and compared with numerical simulations. The planar wiggler has 56 periods with a period of 9.6 mm. Typically, the wiggler field peak amplitude is 5 kG. The experimental efforts have been focused on control of the deviation of the beam toward the side edge of the planar wiggler along the wide transverse direction. It is found that a suitably tapered magnetic field configuration at the wiggler entrance can considerably reduce the rate of the deviation. The effects of the following techniques on beam transport efficiency are also discussed: side focusing, beam transverse velocity tuning at the wiggler entrance, and beam spread limiting. High beam transport efficiency (almost 100%) of a 15 A beam has been obtained in some cases. The results are relevant to development of a free electron laser amplifier for application to stabilizing and heating of plasma in magnetic fusion research

  12. Primary Beam Steering Due To Field Leakage From Superconducting SHMS Magnets

    Science.gov (United States)

    Moore, Michael; Covrig, Silviu; Carlini, Roger; Waidyawansa, Buddhini; Benesch, Jay

    2014-03-01

    The Super High Momentum Spectrometer (SHMS) was designed for the 12 GeV/c physics program in Hall C at Thomas Jefferson National Accelerator (JLab). At JLab an electron beam impinges on a fixed target and scattered particles are analyzed with magnetic spectrometers. The SHMS angular acceptance is 5 .5° 51.8 m from the target. The effects of these magnetic fields on the primary beam line downstream of the target are studied using Opera 3-D and TOSCA. A solution is presented that uses passive elements to shape these fields and assure that the primary beam is steered onto the beam dump window.

  13. 部分剪力连接预应力连续组合梁抗弯性能试验研究%Experimental study on bending behaviors of prestressed steel concrete continuous composite beams with partial shear connection

    Institute of Scientific and Technical Information of China (English)

    胡少伟; 龚洪波

    2013-01-01

    The static load of four prestressed steel concrete continuous composite beams was tested in order to research the effects of the degree of shear connection on the bending behaviors of prestressed steel concrete continuous composite beams, such as the load-deflection characteristic, the load-slip along the span of beams, the strain distribution along the height of composite section, the load-stress increment of prestressed tendons, the interal force redistribution, the failure mode and the ultimate strength of the structure. The research results show that the deformation and interface slip increase and the bending capacity decreases with the reduction of shear connection, but it is less than the direct proportion of the reduction of shear connection. The bending capacity of two composite beams with the shear connection coefficient of 0. 7 was less than 10 percent compared with the full shear connection. The bending moment modulation value of continuous composite beams also decreases with the reduction of shear connection.%为探究剪力连接程度对预应力钢-混凝土连续组合梁的荷载-跨中挠度特征、沿梁纵向的相对滑移分布规律、沿截面高度的应变分布、预应力增量变化以及连续梁的内力重分布过程、破坏机理与极限强度等的影响,进行了4根预应力钢一混凝土连续组合梁的静载全过程试验研究.研究结果表明,随着剪力连接程度的降低,变形及界面滑移明显增大,承载能力有所降低,但降低程度小于剪力连接的降低程度,2根剪力连接程度系数为0.7的组合梁承载力比完全剪力连接组合梁均降低不到10%,随着剪力连接程度的降低连续梁相应弯矩的调幅值也会降低.

  14. The steel septum magnets for beam splitting at the CERN SPS

    CERN Document Server

    Evans, Lyndon R; de Raad, Bastiaan; Thomi, W; Weisse, E

    1978-01-01

    Each of the two slow-extracted proton beams of the CERN 400 GeV Super Proton Synchrotron can be divided into three parts by means of steel- septum magnets for the simultaneous irradiation of up to three production targets. The magnets have radiation-proof coils, integrated vacuum chambers and 'plug-in' connections. The paper describes the design of the magnets and gives the results of the magnetic field measurements. (3 refs).

  15. Multichannel analyzer of energy spectra of a magnetized relativistic electron beam

    International Nuclear Information System (INIS)

    A description of a magnetic step-analyser of intense relativistic electron beam energy spectra is presented. The azimuthal magnetic field in the analyser is created by the current flowing through two coaxial cylinders. The particles move in the analyser along the trajectories, representing spirals with the pitch depending on the energy and rolled on the magnetic field spiral force lines. The magnetic analyser serviceability is demonstrated at the U-1 device with 1.1 MeV electron beam energy and 50 kA current. 6 refs.; 7 figs.; 2 tabs

  16. System of coefficients for charged-particle beam linear transformation by a magnetic dipole element

    International Nuclear Information System (INIS)

    A new technique for consideration of dipole magnet ion-optical effect has been developed to study the problems of commutation and monochromatization of a charged particle beam. In a new form obtained are systematized coefficients of linear transformation (CLT) of the charged particle beam for radial and axial motions in a magnetic dipole element (MDE) including a dipole magnet and two gaps without magnetic field. Given is a method of graphic determination of MDE parameters and main CLT. The new form of coefficients and conditions of the transformations feasibility considerably facilitates the choice and calculation of dipole elements

  17. 预应力组合箱梁抗弯承载能力影响参数分析%Analysis of Influential Parameters of Bending Capacity of Prestressed Composite Box Beams

    Institute of Scientific and Technical Information of China (English)

    胡少伟; 胡汉林

    2012-01-01

    To provide reference for the design of prestressed composite box beams, the sim-plified plastic theory was used to analyze the influential parameters (e. g. the strength of concrete and steel beams, initial tensioning forces of prestressing tendons, layout of the tendons and num-bers of deviation blocks) of the completely shear connected prestressed composite box beams. The results of the analysis demonstrate that under the condition that the sectional dimensions are restricted, the improvement of the strength of the steel beams can effectively improve the bending capacity of the composite box beams and the increase of numbers the prestressing tendons can sig-nificantly increase the bending capacity as well. When the tendons are laid out in a drape way, the initial tensioning values of the tendons can be increased and consequently, the elastic bearing ca-pacity of the beams will be increased. The more the numbers of the deviation blocks are, the greater the increment of the prestress, the less the influence of the secondary effect and the high-er the bending capacity of the beams will be.%为对预应力组合箱梁的设计提供参考,利用简化塑性理论对完全剪力连接的预应力组合梁的抗弯承载力影响参数(混凝土和钢梁强度、预应力筋初始张拉力、预应力筋布筋形式、转向块数量)进行分析.分析结果表明:在截面尺寸受限制时,提高钢梁强度能够有效提高预应力组合梁的抗弯承载力;增加预应力筋的数量可较明显地提高梁体的抗弯承载力;预应力筋采用折线布筋形式时,可提高预应力初始张拉值,以提高预应力组合梁的弹性承载力;转向块布置数量越多,预应力增量越大,二次效应影响越小,预应力组合梁抗弯承载力越高.

  18. 上小下大拼合木梁抗弯性能试验研究%EXPERIMENTAL STUDY ON BENDING BEHAVIOR OF CHINESE TRADITIONAL TIMBER STITCHING BEAMS WITH SMALL TOP AND BIG BOTTOM

    Institute of Scientific and Technical Information of China (English)

    淳庆; 陈春超; 潘建伍

    2014-01-01

    In Chinese traditional timber structures , the way of stitching is often found in beam and purlin members . For 3-purlin beam and 5-purlin beam members , when their bearing capacity and rigidity are not adequate , they are often strengthened by the ways of stitching of beam-jiaobei or beam-suiliangfang .For purlin members , they are often strengthened by the way of stitching of purlin-suilinfang.The stitching beams are mainly two types which are small top and big bottom type and big top and small bottom type .In order to study the bending behavior including the failure mode and bending bearing capacity and strain distribution at mid-span section of timber stitching beams with small top and big bottom , the bending test on six specimens with traditional conformation were carried out , including three deal specimens and three fir specimens .The results show that the failure modes of this kind of stitching beams are all the brittle breakings of bottoms at lower beams .The distribution of section strain along the height of timber stitching beam basically obeys plane hypothesis .Based on the theoretical analysis and experimental results , the computing formulas of bending bearing capacity of this kind of timber stitching beams made of deal and fir were presented .%在中国传统木构建筑中,拼合做法大多见于梁架构件和檩条构件,三架梁、五架梁等梁架构件在承载力或刚度不足时,通常采用梁-角背或梁-随梁枋的拼合做法进行加强,而檩条构件在承载力或刚度不足时,则通常采用檩条-随檩枋的拼合做法加强,拼合做法主要有上小下大和上大下小两种。为研究上小下大拼合木梁的破坏形式、抗弯承载力、截面应变分布,基于传统连接构造做法进行试件设计,对上小下大拼合梁的抗弯性能进行了试验,包括3根杉木梁和3根松木梁。试验结果表明:上小下大拼合木梁受弯破坏模式均为下梁底部木纤维脆性

  19. Measuring the electron beam energy in a magnetic bunch compressor

    International Nuclear Information System (INIS)

    Within this thesis, work was carried out in and around the first bunch compressor chicane of the FLASH (Free-electron LASer in Hamburg) linear accelerator in which two distinct systems were developed for the measurement of an electron beams' position with sub-5 μm precision over a 10 cm range. One of these two systems utilized RF techniques to measure the difference between the arrival-times of two broadband electrical pulses generated by the passage of the electron beam adjacent to a pickup antenna. The other system measured the arrival-times of the pulses from the pickup with an optical technique dependent on the delivery of laser pulses which are synchronized to the RF reference of the machine. The relative advantages and disadvantages of these two techniques are explored and compared to other available approaches to measure the same beam property, including a time-of-flight measurement with two beam arrival-time monitors and a synchrotron light monitor with two photomultiplier tubes. The electron beam position measurement is required as part of a measurement of the electron beam energy and could be used in an intra-bunch-train beam-based feedback system that would stabilize the amplitude of the accelerating field. By stabilizing the accelerating field amplitude, the arrival-time of the electron beam can be made more stable. By stabilizing the electron beam arrival-time relative to a stable reference, diagnostic, seeding, and beam-manipulation lasers can be synchronized to the beam. (orig.)

  20. Magnet lattice design of the SSRF electron-beam transfer lines

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Under three-dimensional plane geometrical constraints (X,Y,θ), with two asymmetric achromatic sections,the combined three-section structural FODO-like magnet lattice design is adopted and finely optimized in the SSRF electron-beam transfer lines. The magnet lattice has high flexibility and robustness, and the Courant-Snyder parameters can be easily adjusted within a wide range to meet the requirements of transmission and injection for different operation modes of the linear accelerator, booster synchrotron, and storage ring. In this article, the main parameters of the linear optics design of the SSRF electron-beam transfer lines are described, involving the physical design criteria, the total geometrical layout, the magnet lattice, and the beam Courant-Snyder parameters matching. The studies of the variant beam dynamic simulation program calculations show that the design purpose of the efficient beam transmission and injection will be basically achieved.

  1. Design of the magnetic field system for Beijing intense slow positron beam transportation

    International Nuclear Information System (INIS)

    A slow positron beam with intensity of 106 e+/s produced by the Beijing Electron-Positron Collider (BEPC) is transported by the 100 Gauss magnetic field system with the oscillation less that 10%. In this paper, the distributions of magnetic field at target chamber, sample chamber and Penning-Trap storage are calculated systematically, and the parameters of solenoidal coils and steering coils are calculated respectively. The correction coils are designed to compensate the affect induced by the geomagnetic field and the bent tube. Results of electron beam experiment show that the positron beams are transported to sample chamber with the beam spot size basically unchanged, and the magnetic field distributions satisfy to the requirement of the slow positron beam system

  2. 柔性连接组合箱梁弹性阶段的弯扭效应分析%Bending-torsion effect of composite box beam with flexible connection in elastic stage

    Institute of Scientific and Technical Information of China (English)

    张彦玲; 葛巍; 李运生

    2013-01-01

    In order to elusidate the bending-tortion mechanism of steel-concrete composite box beam with flexible connection in elastic stage , a finite element analysis combined with the experiment of 4 steel-concrete composite box beams under the bending-tortion action , was conducted by ANSYS soft-ware and the decomposition method , and the influence of the shear connection , the load eccentrici-ty, and the diaphragms number on the bending-tortion effect of composite box beams were studied . The results indicate that , the flexibility of the shear connectors can increase the bending-tortion effect of the composite box beams under the eccentric loads .Compared with the fully connected composite beam , the bending stress , rigid torsional and distortional wrap stress of the composite beams with the shear connection level of 60%, increase by 0.4 , 1.5 and 4.6 times respectively , and no longer coincide with the plane-section law if slip exists at the connection surface;the load ec-centricity and number of middle diaphragms all have little effect on the bending stress , but the rigid torsional and distortional wrap stresses are proportional to the load eccentricity , while the middle dia-phragms reduces the distorsional wrap stress about 1.0 times.%为了明确采用柔性连接件的钢-混凝土组合箱梁在弹性阶段的弯扭作用机理,结合弯扭联合作用下4片组合梁的模型试验,根据荷载分解法,采用ANSYS软件对其弯扭效应进行了分析,并重点研究了剪力连接度、荷载偏心距和横隔板数量对组合箱梁弯扭效应的影响。结果显示:剪力连接件的柔性增大了偏心荷载下组合梁的弯扭效应,与完全连接时相比,剪力连接度为60%时弯曲正应力、刚性扭转正应力和畸变翘曲正应力可分别增大0.4、1.5和4.6倍,且滑移后应力不再符合平截面分布规律;荷载偏心距和横隔板数量对弯曲正应力基本无影响,刚性扭转正应力

  3. Elastic bending bearing capacity calculation of steel-concrete composite beams regarding slip effect%考虑滑移效应的钢-混凝土组合梁弹性受弯承载力计算

    Institute of Scientific and Technical Information of China (English)

    朱松玲

    2012-01-01

    以冷弯薄壁U型钢-混凝土组合梁为研究对象,对组合梁进行了理论分析,建立了考虑滑移效应的弹性抗弯强度计算公式,并计算了8根简支冷弯薄壁U型钢-混凝土组合梁弹性抗弯承载力.将理论计算值与相关文献中的试验结果进行对比,结果表明:考虑滑移效应的弹性弯矩计算值与试验值吻合较好,滑移效应对组合梁弹性抗弯承载力降低的影响不能忽略.%Taking the cold-formed thin-walled U-section steel-concrete composite beams as material,theory analysis have been conducted on the composite beams. Expressions for elasitic strength in consideration of slip effect were given. The bending moment of eight simply supported composite beams were calculated, and the comparison between theory and test results showed that the calculated values of elasitic monent was good consistent with the test results. It is shown that the slip effect on the elastic bending strength can not be ingored.

  4. Perturbed angular correlations for Gd in gadolinium: in-beam comparisons of relative magnetizations

    OpenAIRE

    Stuchbery, A. E.; Wilson, A. N.; Davidson, P. M.; Benczer-Koller, N.

    2006-01-01

    Perturbed angular correlations were measured for Gd ions implanted into gadolinium foils following Coulomb excitation with 40 MeV O-16 beams. A technique for measuring the relative magnetizations of ferromagnetic gadolinium hosts under in-beam conditions is described and discussed. The combined electric-quadrupole and magnetic-dipole interaction is evaluated. The effect of nuclei implanted onto damaged or non-substitutional sites is assessed, as is the effect of misalignment between the inter...

  5. Matrix method and program design of intense beam transport in quadrupole magnet

    International Nuclear Information System (INIS)

    It is very difficult to calculate the nonlinear transport of a intense beam,because the particle trajectories depend on the electric potentials excited by the particle beams, and the electric potentials of the beams depend on the particle trajectories and the particle distributions in the phase spaces. So, it is necessary to solve the problem by iterations to get self-consistent solutions. We use transport matrix method to analyze the transportation in quadrupole magnet of non-intense pulsed beam and intense pulsed beam respectively, and write a computer code for the pulsed beam transporting in quadrupole magnet. The self-consistent solution can obtained by using iteration calculation method. During the calculation, the result can be shown by the prompt graph. (authors)

  6. Polymer gel dosimetry of an electron beam in the presence of a magnetic field

    Science.gov (United States)

    Vandecasteele, J.; De Deene, Y.

    2013-06-01

    The effect of a strong external magnetic field on 4 MeV electron beam was measured with polymer gel dosimetry. The measured entrance dose distribution was compared with a calculated fluence map. The magnetic field was created by use of two permanent Neodymium (NdFeB) magnets that were positioned perpendicular to the electron beam. The magnetic field between the magnets was measured with Hall sensors. Based on the magnetic field measurement and the law of Biot-Savart, the magnetic field distribution was extrapolated. Electron trajectories were calculated using a relativistic Lorentz force operator. Although the simplified computational model that was applied, the shape and position of the calculated entrance fluence map are found to be in good agreement with the measured dose distribution in the first layer of the phantom. In combination with the development of low density polymer gel dosimeters, these preliminary results show the potential of 3D gel dosimetry in MRI-linac applications.

  7. Bending Behavior and Ductility Test of High Performance Steel Beam Based on Hybrid Design%基于混合设计的高性能钢梁抗弯性能及延性试验

    Institute of Scientific and Technical Information of China (English)

    王春生; 段兰; 王继明; 郑丽

    2012-01-01

    基于混合设计的理念,采用中国产高性能钢HPS 485W和普通结构钢Q235,加工制造了6片混合设计工字形钢梁,在跨中单点加载,研究试验梁的抗弯承载能力、变形特征及最终的破坏形态。试验结果表明:腹板屈曲强度和试验梁侧向支撑刚度对试验梁的极限承载力、延性和失效形式有显著影响;试验梁的抗弯承载力主要由翼缘提供,但抗弯延性主要受腹板控制,承载力下降阶段受腹板屈曲强度影响显著;采用厚实截面设计的高性能钢梁可以达到全截面塑性,在有效的侧向限位下高性能钢梁具有很好的延性。试验结果与理论计算结果的对比表明,塑性弯矩理论计算结果与试验值吻合较好。%Based on the concept of hybrid design,6 I-beams were designed and fabricated by high performance steel HPS 485W for flanges and steel Q235 for webs.In the bending test,these simple supported welding beams were loaded at mid-span.After the test,flexural capacity,deformation characteristics and the ultimate failure mode were analyzed during the whole experimental process.Test results show that web bucking strength and the rigidity of lateral bracing significantly affect the ultimate capacity,ductility and failure mode of tested beams.Flexural capacity is mainly contributed by flanges,and ductility is primarily affected by web.The descending stage of the bending capacity is controlled by the web bucking strength.It can be concluded that HPS beam with compact section has good plastic bending behavior and good ductility under effective lateral bracing system.Comparison between test result and theoretical calculation shows good coincidence between theoretical plastic moment and bending process in the test.

  8. Negative ion beam formation, transport and acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, J.G.

    1981-01-01

    The BNL Neutral Beam Development Group is working on the development of negative ion based neutral beam systems, using high current density surface plasma sources of the magnetron and hollow cathode discharge (HCD) type. With the magnetron source, the plan is to transport a 2A D/sup -/ beam through a bending magnet before acceleration to 200 keV. In experiments with a pulsed magnetron, 0.4A of H/sup -/ was transported through a 90/sup 0/, n = 1, bending magnet with 80% transmission. With the lower operating pressure in the HCD source, close coupled acceleration will be applied. The MEQALAC, RFQ, and a dc accelerating scheme with periodic quadrupole focusing are considered for reaching higher energies. A preliminary experiment was performed with quadrupole beam transport and a 3.8 mA beam was transported through a series of twelve quadrupoles, with 3 mm apertures and a total length of 7.2 cm.

  9. Beam director design report: Volume 1

    International Nuclear Information System (INIS)

    A design and fabrication effort for a beam director is documented. The conceptual design provides for the beam to pass first through a bending and focusing system (or ''achromat''), through a second achromat, through an air-to-vacuum interface (the ''beam window''), and finally through the vernier steering system. Following an initial concept study for a beam director, a prototype permanent magnet 300 beam-bending achromat and a prototype vernier steering magnet were designed and built. In volume I, the design requirements are stated, the design is summarized and illustrated, and detailed analysis and computations are provided. Also, a summary of materials used, a description of the manufacturing process, and a summary of project funding are provided

  10. BUCKLING COEFFICIENT OF STEEL-CONCRETE COMPOSITE BEAMS IN NEGATIVE BENDING%钢-混凝土组合梁在负弯矩作用下的屈曲失稳系数研究

    Institute of Scientific and Technical Information of China (English)

    贾远林; 陈世鸣

    2009-01-01

    组合梁与钢梁的侧扭失稳机理与形态存在显著差异,与纯钢梁的失稳相比,组合梁中钢梁上翼缘受到刚度较大的混凝土板约束,表现为与纯钢梁不同的畸变失稳.采用钢构件的Perry-Roberson失稳设计曲线来计算组合梁的失稳极限承载力的适用性急需验证.采用组合梁力学模型,考虑钢梁初始几何缺陷和残余应力影响,进行了组合梁有限元非线性稳定分析,计算结果与试验实测值吻合.通过改变截面参数,对43组组合梁的极限承载力进行了计算,根据EC4截面分类方法,定义了1类、2类截面和3类、4类截面的长细比,研究表明:负弯矩下的组合梁可通过长细比参数采用我国的钢柱稳定曲线进行求解.%A steel-concrete composite beam, whose steel top flange is restrained laterally by the stiff concrete slab, may encounter lateral buckling in distortional mode when in negative bending, which is sharply different from the lateral torsional buckling of bare steel beams. However, the design approach uses the Perry-Roberson formula, which is basically derived from bare steel component tests. To solve this contradiction, inelastic FE buckling analysis is carried out on composite beams in negative bending based on the proposed restrained torsional buckling model. The initial geometric imperfection and the residual stresses are considered. The FE results agree well with the test results. Changing cross-section parameters, 43 groups of composite beams in uniform negative bending are studied. In accordance with EC4, slenderness of the considered beams is defined for, class 1-2 cross-section and class 3-4 cross-section respectively. It is demonstrated that the Chinese Codified steel column design curves can be used in predicting the buckling strength of composite beams with the modified slenderness.

  11. Development of a highly sensitive beam current monitor with a SQUID and superconducting magnetic shield

    International Nuclear Information System (INIS)

    Beam diagnostics are an essential constituent of any accelerator. There are a large variety of beam parameters, and total current is one of the most important parameters for accelerators. A current monitor is used to operate an accelerator efficiently and to improve the performance of the machine. A Faraday cup is the most fundamental current detection process, in which charged particles are stopped in the cup. However, this destructive method cannot be applied for high-current or high-energy beams because the total energy carried by the beam can destroy and activate the intercepting material. Therefore, non-destructive beam current measurement requires the use of current transformers that detect the magnetic field produced by the pulsed or DC beam. On the other hand, a new type of beam current monitor using a low-temperature superconducting (LTS) magnetic shield and an LTS SQUID was developed to measure the faint ion beams that are below the lowest measurable limit of the DC current transformer (DCCT) for atomic-physics studies. Recently, a prototype of a highly sensitive SQUID current monitor for measuring the intensity of faint beams, such as radioisotope beams, was completed for the RIKEN RI beam factory. This monitor is composed of a high-temperature superconducting (HTS) magnetic shield and an HTS SQUID. The first measurements using ion beams were carried out in the CNS experimental hall and RIKEN Ring Cyclotron (RRC). This paper first describes the principle of the conventional current monitor such as the Faraday cup and current transformers. Second, the progress of the LTS SQUID current monitor is discussed, and finally, the present status of the prototype of the LTS SQUID current monitor is discussed, and finally, the present status of the prototype of the HTS SQUID current monitor at RIKEN and the results of the first beam measurement are given. (author)

  12. Measuring the electron beam energy in a magnetic bunch compressor

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Kirsten

    2010-09-15

    Within this thesis, work was carried out in and around the first bunch compressor chicane of the FLASH (Free-electron LASer in Hamburg) linear accelerator in which two distinct systems were developed for the measurement of an electron beams' position with sub-5 {mu}m precision over a 10 cm range. One of these two systems utilized RF techniques to measure the difference between the arrival-times of two broadband electrical pulses generated by the passage of the electron beam adjacent to a pickup antenna. The other system measured the arrival-times of the pulses from the pickup with an optical technique dependent on the delivery of laser pulses which are synchronized to the RF reference of the machine. The relative advantages and disadvantages of these two techniques are explored and compared to other available approaches to measure the same beam property, including a time-of-flight measurement with two beam arrival-time monitors and a synchrotron light monitor with two photomultiplier tubes. The electron beam position measurement is required as part of a measurement of the electron beam energy and could be used in an intra-bunch-train beam-based feedback system that would stabilize the amplitude of the accelerating field. By stabilizing the accelerating field amplitude, the arrival-time of the electron beam can be made more stable. By stabilizing the electron beam arrival-time relative to a stable reference, diagnostic, seeding, and beam-manipulation lasers can be synchronized to the beam. (orig.)

  13. Design and end chamfer simulation of PEFP beam line curved dipole magnets%Design and end chamfer simulation of PEFP beam line curved dipole magnets

    Institute of Scientific and Technical Information of China (English)

    朱应顺; 杨梅; 张卓; 陈宛; 尹宝贵; 石才土; 康文

    2011-01-01

    The design, fabrication and field measurement of 11 DC curved dipole magnets for the PEFP Beam Line have been completed. In this paper, a design method for a complex end chamfer using OPERA-3D is proposed. The conventional method for estimating chamfer sh

  14. Filamentation instability in a light ion beam-plasma system with external magnetic field

    International Nuclear Information System (INIS)

    The filamentation instability for a light ion beam (LIB) penetrating plasma is investigated. For the stabilization of the filamentation instability, an external magnetic field which is parallel to the direction of the light ion beam propagation is applied. From a dispersion relation, linear growth rates of filamentation instabilities are obtained in a light ion beam-plasma system with an external magnetic field. Numerical simulations are carried out using a particle-in-cell (PIC) method. The stabilizing mechanism of the filamentation instability is described. The theory and simulation comparisons illustrate the results. (author)

  15. Perturbed angular correlations for Gd in gadolinium: in-beam comparisons of relative magnetizations

    CERN Document Server

    Stuchbery, A E; Davidson, P M; Wilson, A N

    2006-01-01

    Perturbed angular correlations were measured for Gd ions implanted into gadolinium foils following Coulomb excitation with 40 MeV O-16 beams. A technique for measuring the relative magnetizations of ferromagnetic gadolinium hosts under in-beam conditions is described and discussed. The combined electric-quadrupole and magnetic-dipole interaction is evaluated. The effect of nuclei implanted onto damaged or non-substitutional sites is assessed, as is the effect of misalignment between the internal hyperfine field and the external polarizing field. Thermal effects due to beam heating are discussed.

  16. Relativistic electron beam driven Wake-field excitation in a cold magnetized plasma

    International Nuclear Information System (INIS)

    Excitation of nonlinear Wake-fields by an intense, short, ultra relativistic electron beam in a cold, magnetized plasma is studied analytically, in the electrostatic limit, following the method discussed. From the analytical solution of one dimensional fluid equations, together with Maxwell's equations, in the limit of βph (ratio of wave phase velocity and speed of light) ∼ 1, it is found that under certain conditions of beam density to plasma density ratio, a large amplitude accelerating gradient is generated in the beam's wake. Further the structure of the excited Wake field is compared with Akhiezer-Polovin like wave for a magnetized plasma. (author)

  17. Cryogenic Beam Loss Monitors for the Superconducting Magnets of the LHC

    CERN Document Server

    Bartosik, MR; Sapinski, M; Kurfuerst, C; Griesmayer, E; Eremin, V; Verbitskaya, E

    2014-01-01

    The Beam Loss Monitor detectors close to the interaction points of the Large Hadron Collider are currently located outside the cryostat, far from the superconducting coils of the magnets. In addition to their sensitivity to lost beam particles, they also detect particles coming from the experimental collisions, which do not contribute significantly to the heat deposition in the superconducting coils. In the future, with beams of higher energy and brightness resulting in higher luminosity, distinguishing between these interaction products and dangerous quench-provoking beam losses from the primary proton beams will be challenging. The system can be optimised by locating beam loss monitors as close as possible to the superconducting coils, inside the cold mass in a superfluid helium environment, at 1.9 K. The dose then measured by such Cryogenic Beam Loss Monitors would more precisely correspond to the real dose deposited in the coil. The candidates under investigation for such detectors are based on p+-n-n+ si...

  18. Correction system of the cyclotron magnetic field for quick change of acceleration beam

    International Nuclear Information System (INIS)

    Reduction of the beam changing time is required to increase the available beam time for users. We are developing a technique for reducing the changing time of the magnetic field of the cyclotron, since it takes a long changing time to form the magnetic field for acceleration. Since the deviation of the magnetic field from the desired value for acceleration in the start-up process of the magnetic field dose not decrease in a short time, a correction system of the cyclotron magnetic field with a bipolar power supply and a 5-turn coil was developed. We confirmed that this system enables the magnetic field to be controlled quickly with a pc-based PID controller. (author)

  19. Magnetic field extraction of trap-based electron beams using a high-permeability grid

    International Nuclear Information System (INIS)

    A method to form high quality electrostatically guided lepton beams is explored. Test electron beams are extracted from tailored plasmas confined in a Penning-Malmberg trap. The particles are then extracted from the confining axial magnetic field by passing them through a high magnetic permeability grid with radial tines (a so-called “magnetic spider”). An Einzel lens is used to focus and analyze the beam properties. Numerical simulations are used to model non-adiabatic effects due to the spider, and the predictions are compared with the experimental results. Improvements in beam quality are discussed relative to the use of a hole in a high permeability shield (i.e., in lieu of the spider), and areas for further improvement are described

  20. Generation of a spin-polarized electron beam by multipole magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Karimi, Ebrahim, E-mail: ekarimi@uottawa.ca [Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5 (Canada); Grillo, Vincenzo [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Boyd, Robert W. [Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5 (Canada); Institute of Optics, University of Rochester, Rochester, NY 14627 (United States); Santamato, Enrico [Dipartimento di Scienze Fisiche, Università di Napoli “Federico II”, Compl. Univ. di Monte S. Angelo, 80126 Napoli (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Napoli (Italy)

    2014-03-01

    The propagation of an electron beam in the presence of transverse magnetic fields possessing integer topological charges is presented. The spin–magnetic interaction introduces a nonuniform spin precession of the electrons that gains a space-variant geometrical phase in the transverse plane proportional to the field's topological charge, whose handedness depends on the input electron's spin state. A combination of our proposed device with an electron orbital angular momentum sorter can be utilized as a spin-filter of electron beams in a mid-energy range. We examine these two different configurations of a partial spin-filter generator numerically. The results of this analysis could prove useful in the design of an improved electron microscope. - Highlights: • Theory of generating spin-polarized electron beams. • Interacting electron vortex beams with space-variant magnetic fields. • Bohr–Pauli impossibility of generating spin-polarized free electrons.

  1. On dynamics of electron beams with extended initial radius in reverse magnetic fields

    International Nuclear Information System (INIS)

    The dynamics of the electron flux in the reverse magnetic fields by increase in the beam current initial radius and density is studied. These studies are actual for the works on creating the powerful microwave energy transformers. The results of the numerical modeling showed, that the nonuniformity of the magnetic field radial component and the beam spatial charge field noticeably effect the electron flux with increased initial radius in the reverse magnetic field. The simultaneous increase in the current density and the beam initial radius by the reversible area length, proportional to the number of the beam rotations round its axis, makes it possible to transform up to 80-85 % energy of the electron cyclotron rotation into the direct electric current energy

  2. Dipole magnet and quadrupole lens for the slow extraction of a beam from the Dubna synchrophasotron

    International Nuclear Information System (INIS)

    The deflection system for the second slow extraction (SE-2) of a beam of protons and nuclei from the Dubna synchrophasotron consists of a dipole septum-magnet (VM-2) and a quadrupole septum-lens (VL-2). The magnet, the lens, the current conductors for supplying their windings and the driver used for the SE-2 system are described. A general scheme of cooling the windings of the magnet, lens and conductors is presented. The magnetic characteristics of the VM-2 magnet and the VL-2 lens are given. The system used to control the parameters of the SE-2 is described. 4 refs.; 16 figs

  3. Microwave radiation power of relativistic electron beam with virtual cathode in the external magnetic field

    Science.gov (United States)

    Kurkin, S. A.; Hramov, A. E.; Koronovskii, A. A.

    2013-07-01

    The study of the output power of the electromagnetic radiation of the relativistic electron beam (REB) with virtual cathode in the presence of external magnetic field has been found out. The typical dependencies of the output microwave power of the vircator versus external magnetic field have been analyzed by means of 3D electromagnetic simulation. It has been shown that the power of vircator demonstrates several maxima with external magnetic field growth. The characteristic features of the power behavior are determined by the conditions of the virtual cathode formation in the presence of the external transversal magnetic field and the REB self-magnetic fields.

  4. Microwave radiation power of relativistic electron beam with virtual cathode in the external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kurkin, S. A.; Hramov, A. E.; Koronovskii, A. A. [Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation); Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation)

    2013-07-22

    The study of the output power of the electromagnetic radiation of the relativistic electron beam (REB) with virtual cathode in the presence of external magnetic field has been found out. The typical dependencies of the output microwave power of the vircator versus external magnetic field have been analyzed by means of 3D electromagnetic simulation. It has been shown that the power of vircator demonstrates several maxima with external magnetic field growth. The characteristic features of the power behavior are determined by the conditions of the virtual cathode formation in the presence of the external transversal magnetic field and the REB self-magnetic fields.

  5. Generation of a cold, intense relativistic electron beam using a magnetized foilless diode

    International Nuclear Information System (INIS)

    An annular electron beam with less than 30 mrad of angular velocity spread, a radius of 1 cm, and a current density exceeding 0.4 MA/cm2 has been generated with a magnetized foilless diode. The diode current loss is limited to less than a few percent by careful design of the tapered transition region connecting a self-magnetically insulated vacuum transmission line to the externally magnetized foilless diode. Details of the transition section design and operating characteristics of the electron beam generator are given

  6. Electron beam curable branched chain polyurethane acrylates for magnetic media coatings

    International Nuclear Information System (INIS)

    Electron beam curable binder resins have been studied to realize the high quality magnetic coatings. It was supposed that resins with a higher crosslink density could lead to magnetic coatings with higher abrasion resistance. Branched chain polyurethane acrylates show a higher degree of cure by irradiation with an electron beam in comparison with linear polyurethane acrylates. This paper describes the potential wear resistance between properties of magnetic coatings and the physical properties of the cured unpigmented branched chain polyurethane acrylates that were used as the binder resins. (author)

  7. Experimental studies on ion diodes and theoretical studies on ion beam focusing by magnetic lens

    International Nuclear Information System (INIS)

    Experimental investigation of factors that determine the optimum performance of magnetically insulated ion diodes for light ion inertial confinement fusion (ICF) indicates that degradation of both ion production efficiency and beam divergence occurs when current densities of above about 1.5 kA/cm2 are extracted from passive flashover ion sources on the 1 MV, 4 Ω, 40 ns LION accelerator. Observations of these phenomena are complicated by ablation effects on ion diagnostics at high beam fluences. Theoretical studies of ion beam propagation through plasma filled magnetic lens focusing systems for ICF show that the plasma response is in a whistler wave dominated regime. Criteria are developed for lens and plasma parameters that allow self-field perturbations of the beam to be small enough for good beam transport to an ICF target. (author). 3 figs

  8. Profiling of back-scattered electrons in opposed magnetic field of a Twin Electron Beam Gun

    International Nuclear Information System (INIS)

    Electron gun is extensively used in material processing, physical vapour deposition and atomic vapour based laser processes. In these processes where the electron beam is incident on the substrate, a significant fraction of electron beam gets back-scattered from the target surface. The trajectory of this back scattered electron beam depends on the magnetic field in the vicinity. The fraction of back-scattered depends on the atomic number of the target metal and can be as high as ∼40% of the incident beam current. These back-scattered electrons can cause undesired hot spots and also affect the overall process. Hence, the study of the trajectory of these back-scattered electrons is important. This paper provides the details of experimentally mapped back-scattered electrons of a 2×20kW Twin Electron Beam Gun (TEBG) in opposed magnetic field i.e. with these guns placed at 180° to each other.

  9. Transverse electric and transverse magnetic pulsed-beam decomposition of time-dependent aperture fields.

    Science.gov (United States)

    Melamed, Timor; Abuhasira, Dor; Dayan, David

    2012-06-01

    The present contribution is concerned with applying beam-type expansion to a planar aperture time-dependent (TD) electromagnetic field in which the propagating elements, the electromagnetic pulsed-beams, are a priori decomposed into transverse electric (TE) and transverse magnetic (TM) field polarizations. The propagating field is described as a discrete superposition of tilted, shifted, and delayed TE and TM electromagnetic pulsed-beam propagators over the frame spectral lattice. These waveobjects are evaluated by using TD plane-wave spectral representations. Explicit asymptotic expressions for electromagnetic isodiffracting pulsed-quadratic beam propagators are presented, as well as a numerical example. PMID:22673443

  10. Simulation of adiabatic thermal beams in a periodic solenoidal magnetic focusing field

    OpenAIRE

    Barton, T. J.; Field, David M.; Lang, Kevin M.; Chen, C.

    2012-01-01

    Self-consistent particle-in-cell simulations are performed to verify earlier theoretical predictions of adiabatic thermal beams in a periodic solenoidal magnetic focusing field [ K. R. Samokhvalova, J. Zhou and C. Chen Phys. Plasmas 14 103102 (2007); J. Zhou, K. R. Samokhvalova and C. Chen Phys. Plasmas 15 023102 (2008)]. In particular, results are obtained for adiabatic thermal beams that do not rotate in the Larmor frame. For such beams, the theoretical predictions of the rms beam envelope,...

  11. Magnetic focusing of cold atomic beam with a 2D array of current-carrying wires

    Institute of Scientific and Technical Information of China (English)

    Yang Liu; Min Yun; Jianping Yin

    2006-01-01

    @@ A new scheme to realize a two-dimensional (2D) array of magnetic micro-lenses for a cold atomic beam,formed by an array of square current-carrying wires,is proposed.We calculate the spatial distributions of the magnetic fields from the array of current-carrying wires and the magnetic focusing potential for cold rubidium atoms,and study the dynamic focusing processes of cold atoms passing through the magnetic micro-lens array and its focusing properties by using Monte-Carlo simulations and trajectory tracing method.The result shows that the proposed micro-lens array can be used to focus effectively a cold atomic beam,even to load ultracold atoms or a BEC sample into a 2D optical lattice formed by blue detuned hollow beams.

  12. Efficient Injection of Electron Beams into Magnetic Guide Fields

    International Nuclear Information System (INIS)

    Preliminary experimental and modeling study of injection and transport of high current electron beams in current-neutralized background gas has been performed. Initial analysis of the results indicates that high current triaxial ring diode operates very reproducibly in the pinch mode. High current density beam can be injected efficiently into the drift region, using azimuthal guide field with reduced intensity near the injection region. This was shown to improve the effectiveness of capturing the beam for the transport. The transport length was insufficient to measure losses, such as would arise from scattering with the background gas

  13. Efficient Injection of Electron Beams into Magnetic Guide Fields

    Energy Technology Data Exchange (ETDEWEB)

    Chorny, V.; Cooperstein, G.; Dubyna, V.; Frolov, O.; Harper-Slaboszewicz, V.; Hinshelwood, D.; Schneider, R.; Solovyov, V.; Tsepilov, H.; Vitkovitsky, I.; Ware, K,

    1999-06-08

    Preliminary experimental and modeling study of injection and transport of high current electron beams in current-neutralized background gas has been performed. Initial analysis of the results indicates that high current triaxial ring diode operates very reproducibly in the pinch mode. High current density beam can be injected efficiently into the drift region, using azimuthal guide field with reduced intensity near the injection region. This was shown to improve the effectiveness of capturing the beam for the transport. The transport length was insufficient to measure losses, such as would arise from scattering with the background gas.

  14. Beam size measurement of the stored electron beam at the APS storage ring using pinhole optics

    International Nuclear Information System (INIS)

    Beam sizes of the stored electron beam at the APS storage ring were measured using pinhole optics and bending magnet x-rays in single-bunch and low-current mode. A pinhole of 25 μm and a fast x-ray imaging system were located 23.8 m and 35.4 m from the source, respectively. The x-ray imaging system consists of a CdWO4 scintillation crystal 60 μm thick, an optical imaging system, and a CCD detector. A measurement time of a few tenths of a second was obtained on a photon beam of E>30 keV produced in a bending magnet from a 7-GeV electron beam of 2mA current. The measured vertical and horizontal sizes of the electron beam were in reasonable agreement with the expected values

  15. Formation of large-area heavy-ion uniform beams using multipole magnets in TIARA, JAEA

    International Nuclear Information System (INIS)

    A research and development study related to the uniformization of the transverse beam intensity distribution using multipole magnets is ongoing for a new uniform irradiation method of proton and heavy-ion beams at an azimuthally-varying-field cyclotron facility of TIARA in Japan Atomic Energy Agency. In this method, a uniform transverse intensity distribution can be formed by folding the tail of a Gaussian initial distribution into the inside with a nonlinear focusing force of multipole magnets. First, a Gaussian-like intensity distribution was generated from a complicated distribution of the beam accelerated by the cyclotron through multiple Coulomb scattering using a thin foil at a low loss of beam energy. The response of Gafchromic radiochromic films to various ion beams was investigated for the evaluation of the size and uniformity in a large-area beam. Large-area (>100 cm2) uniform distributions have been attained for argon ion beams of 4 ∼ 13 MeV/u, as well as for proton beams of 10 MeV. Heavy-ion uniform beams will be applied to research and production of functional materials. (author)

  16. Probing the magnetic moment of FePt micromagnets prepared by focused ion beam milling

    Science.gov (United States)

    Overweg, H. C.; den Haan, A. M. J.; Eerkens, H. J.; Alkemade, P. F. A.; La Rooij, A. L.; Spreeuw, R. J. C.; Bossoni, L.; Oosterkamp, T. H.

    2015-08-01

    We investigate the degradation of the magnetic moment of a 300 nm thick FePt film induced by Focused Ion Beam (FIB) milling. A 1 μm × 8 μm rod is milled out of a film by a FIB process and is attached to a cantilever by electron beam induced deposition. Its magnetic moment is determined by frequency-shift cantilever magnetometry. We find that the magnetic moment of the rod is μ = 1.1 ± 0.1 × 10-12 Am2, which implies that 70% of the magnetic moment is preserved during the FIB milling process. This result has important implications for atom trapping and magnetic resonance force microscopy, which are addressed in this paper.

  17. Wideband Precision Current Transformer for the Magnet Current of the Beam Extraction Kicker Magnet of the Large Hadron Collider

    CERN Document Server

    Gräwer, G

    2004-01-01

    The LHC beam extraction system is composed of 15 fast kicker magnets per beam to extract the particles in one turn of the collider and to safely dispose them on external absorbers. Each magnet is powered by a separate pulse generator. The generator produces a magnet current pulse with 3 us rise time, 20 kA amplitude and 1.8 ms fall time, of which 90 us are needed to dump the beam. The beam extraction system requires a high level of reliability. To detect any change in the magnet current characteristics, which might indicate a slow degradation of the pulse generator, a high precision wideband current transformer will be installed. For redundancy reasons, the results obtained with this device will be cross-checked with a Rogowski coil, installed adjacent to the transformer. A prototype transformer has been successfully tested at nominal current levels and showed satisfactory results compared with the output of a high frequency resistive coaxial shunt. The annular core of the ring type transformer is composed of...

  18. 腹板嵌入式组合梁抗弯性能理论和试验研究%Theoretical and Experimental Analysis of Bending Behavior of Composite Beam with Notched Web

    Institute of Scientific and Technical Information of China (English)

    李国强; 李亮; 李现辉; 司林军

    2011-01-01

    提出了一种新型腹板嵌入式钢-混凝土组合梁,并对该组合梁的整体抗弯性能和抗剪性能进行了研究.首先阐述了腹板嵌入式钢-混凝土组合梁的构成、受力特点和主要优点,然后介绍了该组合梁的抗弯承载力、钢梁与混凝土翼板之间的滑移以及挠度计算公式.通过竖向荷载作用下的静力加载试验对4个腹板嵌入式钢-混凝土组合梁试件的抗弯承载力、滑移影响及破坏特征进行了足尺试验研究,并利用有限元方法对4个试件的试验结果进行了对比,最后将理论公式得到的腹板嵌入式钢-混凝土组合梁的抗弯承载力、滑移及挠度计算结果与试验及有限元分析的结果进行比较,验证了理论公式的可靠性.研究表明,腹板嵌入式钢-混凝土组合梁具有良好的整体抗弯性能及抗剪性能,能够节约钢材.%A new kind of steel-concrete composite beam with notched web is proposed, and the bend and shear behaviors of this composite beam are investigated. First of all, the constitution, bearing characteristics and merits of the steel-concrete composite beam with notched web are introduced; then, a group of formulas about the bending capacity, slip between the steel beam and the concrete flange, and the deflection are introduced; after that, the bending behavior, slip effect and bearing characteristic of the steel-concrete composite beam with notched web are studied on 4 specimens, which are tested by applying two concreted vertical loads on the top of concrete flange. And the finite element model is adopted to analyze the results of the 4 specimens; finally, the reliabilities of the formulas are verified by comparing the results of theoretical formulas, the results of tests and that of finite element analysis. Study shows that the bend behavior and shear behavior are fine, and the popularization of this new kind of composite beam which can be broadly used in building engineering will save the

  19. On the stability of ion beam in a layer with crossed electric and magnetic fields and magnetized electron background

    International Nuclear Information System (INIS)

    Dissipation instability of stationary states of space heterogeneous compensated ion beam in a layer with crossed electric and magnetic fields is considered within the framework of linear hydrodynamic description at random ΔV/V0 ratio, where ΔV-change of V0 initial beam velocity at layer length. The apparent form of space change of amplitude of initial perturbations of short-wave oscillations, propagating along the beam, was determined. It is shown, that stabilizing effect of accelerating field is manifested by the fact, that oscillations at the given length of diode gap have no time to develop. The obtained results can be used for study of stability of stationary states of accelerating magnetically insulated diode systems and recuperators

  20. In situ baking method for degassing of a kicker magnet in accelerator beam line

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Junichiro, E-mail: kamiya.junichiro@jaea.go.jp; Ogiwara, Norio; Yanagibashi, Toru; Kinsho, Michikazu [Japan Atomic Energy Agency, J-PARC Center, Ooaza Shirakata 2-4, Tokai, Naka, Ibaraki 319-1195 (Japan); Yasuda, Yuichi [SAKAGUCHI E.H VOC CORP., Sakura Dai-san Kogyodanchi 1-8-6, Osaku, Sakura, Chiba 285-0802 (Japan)

    2016-03-15

    In this study, the authors propose a new in situ degassing method by which only kicker magnets in the accelerator beam line are baked out without raising the temperature of the vacuum chamber to prevent unwanted thermal expansion of the chamber. By simply installing the heater and thermal radiation shield plates between the kicker magnet and the chamber wall, most of the heat flux from the heater directs toward the kicker magnet. The result of the verification test showed that each part of the kicker magnet was heated to above the target temperature with a small rise in the vacuum chamber temperature. A graphite heater was selected in this application to bake-out the kicker magnet in the beam line to ensure reliability and easy maintainability of the heater. The vacuum characteristics of graphite were suitable for heater operation in the beam line. A preliminary heat-up test conducted in the accelerator beam line also showed that each part of the kicker magnet was successfully heated and that thermal expansion of the chamber was negligibly small.

  1. Focused Azimuthally E-Polarized Vector Beam and Spatial Magnetic Resolution below the Diffraction Limit

    CERN Document Server

    Veysi, Mehdi; Capolino, Filippo

    2016-01-01

    An azimuthally E-polarized vector beam (AEVB) has a salient feature that it contains a magnetic-dominant region within which electric field has a null and longitudinal magnetic field is maximum. Fresnel diffraction theory and plane-wave spectral (PWS) calculations are applied to quantify the field features of such a beam upon focusing through a lens. The diffraction-limited full width at half maximum (FWHM) of the beams longitudinal magnetic field intensity profile and complementary FWHM (CFWHM) of the beam's annular-shaped total electric field intensity profile are calculated at the lens's focal plane as a function of the lens's paraxial focal distance. Subsequently, we demonstrate, for the first time, that a very high resolution magnetic field at optical frequency with the total magnetic field FWHM of 0.23{\\lambda}(magnetic field spot size of 0.04{\\lambda}^2) can be achieved by placing a subwavelength dense dielectric Mie scatterer in the minimum-waist plane of a self-standing converging AEVB. The theory sh...

  2. Merged neutral beams

    Energy Technology Data Exchange (ETDEWEB)

    Osterwalder, Andreas [Ecole Polytechnique Federale de Lausanne (EPFL), Institute for Chemical Sciences and Engineering, Lausanne (Switzerland)

    2015-12-15

    A detailed description of a merged beam apparatus for the study of low energy molecular scattering is given. This review is intended to guide any scientist who plans to construct a similar experiment, and to provide some inspiration in describing the approach we chose to our goal. In our experiment a supersonic expansion of paramagnetic particles is merged with one of polar molecules. A magnetic and an electric multipole guide are used to bend the two beams onto the same axis. We here describe in detail how the apparatus is designed, characterised, and operated. (orig.)

  3. Measurement of irradiation creep in bending

    International Nuclear Information System (INIS)

    The major deformation modes in LMFBR fuel channels are bowing caused by neutron flux and temperature gradients and dilation due to stresses imposed by the flowing sodium. In both cases, the stress state of interest is bending. The bulk of irradiation creep data has been generated by simply loaded specimens such as tensile or biaxial pressurized tubes but it is questionable whether this data can be used to predict creep in bending. An irradiation creep experiment using beams loaded in primary bending has been designed to investigate this premise

  4. Measurement of irradiation creep in bending. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    McSherry, A.J.; Marshall, J.; Patel, M.R.

    1980-01-31

    The major deformation modes in LMFBR fuel channels are bowing caused by neutron flux and temperature gradients and dilation due to stresses imposed by the flowing sodium. In both cases, the stress state of interest is bending. The bulk of irradiation creep data has been generated by simply loaded specimens such as tensile or biaxial pressurized tubes but it is questionable whether this data can be used to predict creep in bending. An irradiation creep experiment using beams loaded in primary bending has been designed to investigate this premise.

  5. Use of electron beam reflexing in a magnetic bottle to produce an ion beam

    International Nuclear Information System (INIS)

    Generally an ion diode uses an applied magnetic field parallel to the anode, which prevents electrons from crossing the anode-cathode space. This magnetic field cancels the axial electron current and the accelerator energy is then delivered through ions. A new concept has been introduced in our laboratory: electrons can cross the A-K space, then are reflected back with an axial applied magnetic field, electron reflection beeing produced by a magnetic field bottle located behind the anode foil. Magnetic field is 1 Tesla in the A-K space and is 20 Tesla at maximum in the magnetic bottle. A thin foil serves as the anode, such that ion energy deposition is low

  6. Beam dynamics performances and applications of a low-energy electron-beam magnetic bunch compressor

    OpenAIRE

    Prokop, C. R.; Piot, P; Carlsten, B. E.; Church, M.

    2013-01-01

    Many front-end applications of electron linear accelerators rely on the production of temporally-compressed bunches. The shortening of electron bunches is often realized with magnetic bunch compressors located in high-energy sections of accelerators. Magnetic compression is subject to collective effects including space charge and self interaction via coherent synchrotron radiation. In this paper we explore the application of magnetic compression to low-energy ($\\sim 40$ MeV), high-charge (nC)...

  7. Terahertz generation by two cross focused Gaussian laser beams in magnetized plasma

    International Nuclear Information System (INIS)

    This paper presents a theoretical model for terahertz (THz) radiation generation by two cross-focused Gaussian laser beams in a collisionless magnetoplasma. The plasma is redistributed due to the ponderomotive nonlinearity which leads to the cross focusing of the laser beams. The focusing of the copropagating laser beams increases with increasing the externally applied static magnetic field which is perpendicular to the wave propagation direction. The nonlinear current at THz frequency arises on account of nonlinear ponderomotive force as a result of beating of the two lasers. The generated THz radiation amplitude increases significantly with increasing magnetic field. The cross focusing of two laser beams enhances the THz yield. Optimization of laser-plasma parameters gives the radiated normalized THz power of the order of 10 kW

  8. Effect of transverse magnetic field on generation of electron beam in gas diode

    International Nuclear Information System (INIS)

    One studied experimentally the effect of the transverse magnetic field (0.08 and 0.016 T) on the generation of an electron beam within a gas diode. At U=25 kV gas diode voltage and helium low pressure (45 Torr) the transverse magnetic field is shown to affect the beam current amplitude outside the foil and on its foil cross section distribution. Under the increased pressure values and at generation of an ultra short-time avalanche electron beam (UAEB) in helium, nitrogen and in air the transverse magnetic field is shown to affect negligibly the UAEB amplitude and duration outside the foil. At the generator voltage equal to hundreds of kilovolts a portion of the escaping electrons was found to arrive to the gas diode lateral walls including those from the discharge plasma in the vicinity of a cathode

  9. Chaotic oscillations in electron beam with virtual cathode in external magnetic field

    Science.gov (United States)

    Hramov, A. E.; Koronovskiy, A. A.; Kurkin, S. A.; Rempen, I. S.

    2011-11-01

    This article presents the results of a numerical study of external magnetic field influence on the conditions and mechanisms of virtual cathode (VC) formation in a relativistic electron beam. It also considers other related issues, e.g. peculiarities of nonlinear dynamics of electron beam with VC under changed external magnetic field, different mechanisms of VC oscillation chaotisation leading to complication of vircator system dynamics and appearance of multi-frequency VC oscillations. General systemic mechanism of VC oscillation chaotisation has been identified which is connected with formation of electronic patterns in electron beam whose interaction in the common field of spatial charge determines appearance of additional inner feedback. Transition from chaotic to periodical oscillation regime is found to be connected with destroying the mechanism of secondary electronic structures (electron bunches) formation. Besides, the influence of extent of screening of electron gun from magnetic field is discussed.

  10. Quench Tests of LHC Magnets with Beam: Studies on Beam Loss development and determination of Quench levels

    CERN Document Server

    Priebe, A; Sapinski, M

    The application of superconducting materials in the field of high energy accelerator physics not only opens the doors to the generation of the magnetic fields unattainable to normal conductors but also demands facing new challenges. A transition fromthe superconducting state, which is characterized by a resistance-free flow of the electric current, to the normal conducting state is called quenching. This process might be extremely dangerous and even lead to destruction of amagnet superconducting coil if no protecting actions are taken. Therefore, the knowledge of a magnet quench level, i.e. amount of energy which causes the transition to the resistive state, is crucial for the safety and operational efficiency of the accelerator. Regarding that, specific thresholds are incorporated to dedicated quench prevention systems in order to suppress the origin of detected energy perturbation, for example beam losses, or mitigate the consequences of the quenching process by dissipating the energy stored in the magnetic...

  11. 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...

  12. ILC Beam Energy Measurement by means of Laser Compton Backscattering

    OpenAIRE

    Muchnoi, N.; Schreiber, H. J.; Viti, M

    2008-01-01

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered $\\gamma$-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitiv...

  13. Space-charge dominated beam transport in magnetic quadrupoles with large aperture ratios

    International Nuclear Information System (INIS)

    This memo summarizes the results of calculations of the usable aperture ratio for short period, magnetic quadrupoles for both ILSE magnet designs and the more general, heavy-ion fusion (HIF) ''driver'' case. From both analytic decomposition of the magnetic field in a periodic lattice and particle code simulations of beam transport, we find that fringe field nonlinearities and associated emittance growth become quite large when the beam radius ab exceeds one-quarter or so of the half-lattice period L. For ILSE, there are a number of magnet designs which can transport the specified line charge without any significant difficulties, primarily because the ratio ab/L is of order 0.1 or less. For larger sized beams such as one might employ in the low energy part of a driver, there are problems with properly matching the beam to the transport lattice in both the macroscopic and microscopic sense as ab/L exceeds 0.2. For even larger aperture ratios, particle loss can occur, with the threshold in beam radius roughly scaling inversely with σo, the single particle phase advance per lattice period

  14. Prospects for Detecting a Neutrino Magnetic Moment with a Tritium Source and Beta-beams

    OpenAIRE

    McLaughlin, G. C.; Volpe, C.

    2003-01-01

    We compare the prospects for detecting a neutrino magnetic moment by the measurement of neutrinos from a tritium source, reactors and low-energy beta-beams. In all cases the neutrinos or antineutrinos are detected by scattering of electrons. We find that a large (20 MCurie) tritium source could improve the limit on the neutrino magnetic moment significantly, down to the level of a few $\\times 10^{-12}$ while low-energy beta-beams with sufficiently rapid production of ions could improve the li...

  15. Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Solenoidal Magnetic Field I: Weak Magnetic Field Limit

    Energy Technology Data Exchange (ETDEWEB)

    Kaganovich, I. D., Startsev, E. A., Sefkow, A. B., Davidson, R. C.

    2008-10-10

    Propagation of an intense charged particle beam pulse through a background plasma is a common problem in astrophysics and plasma applications. The plasma can effectively neutralize the charge and current of the beam pulse, and thus provides a convenient medium for beam transport. The application of a small solenoidal magnetic field can drastically change the self-magnetic and self- electric fields of the beam pulse, thus allowing effective control of the beam transport through the background plasma. An analytic model is developed to describe the self-magnetic field of a finite- length ion beam pulse propagating in a cold background plasma in a solenoidal magnetic field. The analytic studies show that the solenoidal magnetic field starts to infuence the self-electric and self-magnetic fields when ωce > ωpeβb, where ωce = eβ/mec is the electron gyrofrequency, ωpe is the electron plasma frequency, and βb = Vb/c is the ion beam velocity relative to the speed of light. This condition typically holds for relatively small magnetic fields (about 100G). Analytical formulas are derived for the effective radial force acting on the beam ions, which can be used to minimize beam pinching. The results of analytic theory have been verified by comparison with the simulation results obtained from two particle-in-cell codes, which show good agreement.

  16. 整体-局部弯曲模型及其在简支组合梁中的应用%GLOBAL-LOCAL BENDING MODEL AND ITS APPLICATION IN SIMPLY SUPPORTED COMPOSITE BEAM

    Institute of Scientific and Technical Information of China (English)

    丁敏; 蒋秀根; 孟石平; 张凤杰; 董蔚; 许宁

    2012-01-01

    为建立钢.混凝土组合梁界面滑移及考虑界面滑移的挠曲线计算模型,基于Bernoulli梁理论和剪力连接件线性剪力.滑移模型,从梁体平衡方程、几何方程和物理方程出发,建立了基于全微分的截面弯矩和剪力分配计算方法,提出了适用于组合梁变形分析的整体.局部弯曲模型,通过引入整体弯矩分配系数,建立了组合梁界面滑移及挠度控制方程。将整体.局部弯曲模型应用于简支组合梁变形分析,利用MAPLE软件对其进行求解,得到了均布荷载、跨中集中荷载、对称集中荷载三种荷载工况下的简支组合梁界面滑移公式与挠曲线方程,与国内外已有试验结果和相关研究成果相对比,结果表明该文计算结果与实际情况吻合较好。%To present the calculation model for the interface slip and deflection curve considering the interface slip of a steel-concrete composite beam, on the basis of Bernoulli beam theory and the linear shear-slip model of shear connectors, the method to calculate the distribution of the bending moment and shearing force of cross sections by total differentiation, as well as a global-local bending model suitable for composite beam deformation analysis are proposed by means of the equilibrium equation, geometric equation and constitutive equation of the beam. Furthermore, the control equation for the interface slip and deflection of the composite beam is put forward using the distribution coefficient of global moment. The formulas for the interface slip and deflection curve equation of a simply supported composite beam under a uniform distributed load, a concentrated load at mid-span and a symmetric concentrated load are proposed by applying the global-local bending model to the deformation analysis of the simply supported composite beam and by calculating with MAPLE software. Compared with the existing test data, the calculation results meet well with the

  17. Application of Chebyshev Formalism to Identify Nonlinear Magnetic Field Components in Beam Transport Systems

    Energy Technology Data Exchange (ETDEWEB)

    Spata, Michael [Old Dominion Univ., Norfolk, VA (United States)

    2012-08-01

    An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a beam-based technique for characterizing the extent of the nonlinearity of the magnetic fields of a beam transport system. Horizontally and vertically oriented pairs of air-core kicker magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the beam orbit relative to the unperturbed reference orbit. Fourier decomposition of the position data at eight different points along the beamline was then used to measure the amplitude of these frequencies. For a purely linear transport system one expects to find solely the frequencies that were applied to the kickers with amplitudes that depend on the phase advance of the lattice. In the presence of nonlinear fields one expects to also find harmonics of the driving frequencies that depend on the order of the nonlinearity. Chebyshev polynomials and their unique properties allow one to directly quantify the magnitude of the nonlinearity with the minimum error. A calibration standard was developed using one of the sextupole magnets in a CEBAF beamline. The technique was then applied to a pair of Arc 1 dipoles and then to the magnets in the Transport Recombiner beamline to measure their multipole content as a function of transverse position within the magnets.

  18. An RF beam sweeper for purifying in-flight produced secondary ion beams at ATLAS

    International Nuclear Information System (INIS)

    A new large-acceptance RF beam sweeper was designed, constructed and put into operation with the goal to remove the energy-degraded primary beams tails from radioactive beams (RIB) produced by in-flight transfer or charge-exchange reactions. The system makes use of the velocity difference between the RIB beam of interest and the remaining tails of the primary beam after momentum selection by a bending magnet. The time-delayed primary beam components are deflected vertically out of the beam path by the RF sweeper, significantly reducing the stable beam background. Beam purity for the in-flight radioactive ion beams as high as 96% has been achieved with this system

  19. Experiments with low energy ion beam transport into toroidal magnetic fields

    CERN Document Server

    Joshi, N; Meusel, O; Ratzinger, U

    2016-01-01

    The stellarator-type storage ring for accumulation of multi- Ampere proton and ion beams with energies in the range of $100~AkeV$ to $1~AMeV$ is designed at Frankfurt university. The main idea for beam confinement with high transversal momentum acceptance was presented in EPAC2006. This ring is typically suited for experiments in plasma physics and nuclear astrophysics. The accumulator ring with a closed longitudinal magnetic field is foreseen with a strength up to $6-8~T$. The experiments with two room temperature 30 degree toroids are needed. The beam transport experiments in toroidal magnetic fields were first described in EPAC2008 within the framework of a proposed low energy ion storage ring. The test setup aims on developing a ring injection system with two beam lines representing the main beam line and the injection line. The primary beam line for the experiments was installed and successfully commissioned in 2009. A special diagnostics probe for \\textit{"in situ"} ion beam detection was installed.This...

  20. Mechanical behaviour of vacuum chambers and beam screens under quench conditions in dipole and quadrupole fields

    CERN Document Server

    Rathjen, C

    2002-01-01

    A method based on analytical formulas is described to calculate bending moments, stresses, and deformations of vacuum chambers and beam screens in dipole and in quadrupole fields during a magnet quench. Solutions are given for circular and racetrack shaped structures. Without the need of time consuming calculations the solutions enable a quick design and verification of vacuum chambers and beam screens.

  1. The influence of magnetic fields on the wake field and stopping power of an ion-beam pulse in plasmas

    International Nuclear Information System (INIS)

    We performed two-dimensional particle-in-cell simulations to investigate how a magnetic field affects the wake field and stopping power of an ion-beam pulse moving in plasmas. The corresponding density of plasma electrons is investigated. At a weak magnetic field, the wakes exhibit typical V-shaped cone structures. As the magnetic field strengthens, the wakes spread and lose their typical V-shaped structures. At a sufficiently strong magnetic field, the wakes exhibit conversed V-shaped structures. Additionally, strengthening the magnetic field reduces the stopping power in regions of low and high beam density. However, the influence of the magnetic field becomes complicated in regions of moderate beam density. The stopping power increases in a weak magnetic field, but it decreases in a strong magnetic field. At high beam density and moderate magnetic field, two low-density channels of plasma electrons appear on both sides of the incident beam pulse trajectory. This is because electrons near the beam pulses will be attracted and move along with the beam pulses, while other electrons nearby are restricted by the magnetic field and cannot fill the gap

  2. Beam dynamics performances and applications of a low-energy electron-beam magnetic bunch compressor

    CERN Document Server

    Prokop, C R; Carlsten, B E; Church, M

    2013-01-01

    Many front-end applications of electron linear accelerators rely on the production of temporally-compressed bunches. The shortening of electron bunches is often realized with magnetic bunch compressors located in high-energy sections of accelerators. Magnetic compression is subject to collective effects including space charge and self interaction via coherent synchrotron radiation. In this paper we explore the application of magnetic compression to low-energy ($\\sim 40$ MeV), high-charge (nC) electron bunches with low normalized transverse emittances ($< 5$ $\\mu$m).

  3. An analytical study of double bend achromat lattice

    Science.gov (United States)

    Fakhri, Ali Akbar; Kant, Pradeep; Singh, Gurnam; Ghodke, A. D.

    2015-03-01

    In a double bend achromat, Chasman-Green (CG) lattice represents the basic structure for low emittance synchrotron radiation sources. In the basic structure of CG lattice single focussing quadrupole (QF) magnet is used to form an achromat. In this paper, this CG lattice is discussed and an analytical relation is presented, showing the limitation of basic CG lattice to provide the theoretical minimum beam emittance in achromatic condition. To satisfy theoretical minimum beam emittance parameters, achromat having two, three, and four quadrupole structures is presented. In this structure, different arrangements of QF and defocusing quadruple (QD) are used. An analytical approach assuming quadrupoles as thin lenses has been followed for studying these structures. A study of Indus-2 lattice in which QF-QD-QF configuration in the achromat part has been adopted is also presented.

  4. An analytical study of double bend achromat lattice

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, Ali Akbar, E-mail: fakhri@rrcat.gov.in; Kant, Pradeep; Singh, Gurnam; Ghodke, A. D. [Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

    2015-03-15

    In a double bend achromat, Chasman-Green (CG) lattice represents the basic structure for low emittance synchrotron radiation sources. In the basic structure of CG lattice single focussing quadrupole (QF) magnet is used to form an achromat. In this paper, this CG lattice is discussed and an analytical relation is presented, showing the limitation of basic CG lattice to provide the theoretical minimum beam emittance in achromatic condition. To satisfy theoretical minimum beam emittance parameters, achromat having two, three, and four quadrupole structures is presented. In this structure, different arrangements of QF and defocusing quadruple (QD) are used. An analytical approach assuming quadrupoles as thin lenses has been followed for studying these structures. A study of Indus-2 lattice in which QF-QD-QF configuration in the achromat part has been adopted is also presented.

  5. An analytical study of double bend achromat lattice

    International Nuclear Information System (INIS)

    In a double bend achromat, Chasman-Green (CG) lattice represents the basic structure for low emittance synchrotron radiation sources. In the basic structure of CG lattice single focussing quadrupole (QF) magnet is used to form an achromat. In this paper, this CG lattice is discussed and an analytical relation is presented, showing the limitation of basic CG lattice to provide the theoretical minimum beam emittance in achromatic condition. To satisfy theoretical minimum beam emittance parameters, achromat having two, three, and four quadrupole structures is presented. In this structure, different arrangements of QF and defocusing quadruple (QD) are used. An analytical approach assuming quadrupoles as thin lenses has been followed for studying these structures. A study of Indus-2 lattice in which QF-QD-QF configuration in the achromat part has been adopted is also presented

  6. Laminated and pasting CFRP composite strengthening RC beam bending bearing capacity experimental study%叠合与粘贴CFRP复合加固RC简支梁的抗弯承载力试验研究

    Institute of Scientific and Technical Information of China (English)

    李红霞; 郭艳芹; 张雷顺

    2013-01-01

    通过分析叠合与粘贴CFRP复合加固RC简支梁承载力的两大主要影响因素,运用现有计算方法推导得出复合加固RC梁的抗弯承载力计算公式,试验发现:仅粘贴CFRP加固RC梁,虽能有效提高构件承载力,但由于下部受拉储备充足而使上部受压储备相对不足,使构件发生类似超筋梁的脆性破坏,其极限承载力明显低于上部同时有叠合层的RC梁.试验比较发现:所用计算方法得出的计算值与试验值相比偏小,计算公式偏于保守.%Through the analysis of laminated composite of RC beams strengthened with bonded CFRP bearing force of the two major influencing factors, using the existing calculation method of composite strengthening RC beam is derived the formula to calculate the bending bearing capacity, test found that: only paste CFRP strengthened RC beams, can effectively improve the bearing capacity of members, but due to the lower tensile reserves and the upper compression reserve is relatively insufficient, make a component similar over-reinforced beam brittle failure, its ultimate bearing capacity was significantly lower than the upper part while the laminated layer of RC beam. Test comparison showed that:this method calculated value compared with experiment data is small,conservative calculation formula.

  7. Open-loop correction for an eddy current dominated beam-switching magnet

    International Nuclear Information System (INIS)

    A beam-switching magnet and the pulsed power supply it requires have been developed for the Japan Proton Accelerator Research Complex. To switch bunched proton beams, the dipole magnetic field must reach its maximum value within 40 ms. In addition, the field flatness should be less than 5 × 10−4 to guide each bunched beam to the designed orbit. From a magnetic field measurement by using a long search coil, it was found that an eddy current in the thick endplates and laminated core disturbs the rise of the magnetic field. The eddy current also deteriorates the field flatness over the required flat-top period. The measured field flatness was 5 × 10−3. By using a double-exponential equation to approximate the measured magnetic field, a compensation pattern for the eddy current was calculated. The integrated magnetic field was measured while using the newly developed open-loop compensation system. A field flatness of less than 5 × 10−4, which is an acceptable value, was achieved

  8. Beam Stability at the Advanced Photon Source

    CERN Document Server

    Decker, Glenn

    2005-01-01

    The Advanced Photon Source has been in operation since 1996. Since that time, extensive incremental improvements to orbit stabilization systems have been made. This includes the addition of 80 channels of narrowband rf beam position monitors (bpm's), 40 channels of bending magnet photon bpm's, and most recently the inclusion of 36 insertion device photon bpm's into the orbit correction response matrix. In addition, considerable improvements have been made in the area of power supply regulation, both for the main multipole magnets and the steering corrector magnets. The present status of overall performance will be discussed, including long term pointing stability, reproducibility, and AC beam motion.

  9. Geometry effect on the behaviour of single and glue-laminated glass fibre reinforced polymer composite sandwich beams loaded in four-point bending

    International Nuclear Information System (INIS)

    Highlights: ► Investigated the behaviour of single and glue-laminated GFRP sandwich beam. ► Effect of shear span to depth was a key factor affecting the overall behaviour. ► Comparison with prediction models gave reasonable results in specific regions. ► A failure map was developed to identify the shear and flexural failures of panels. -- Abstract: The research investigated the behaviour of single and glue laminated glass fibre reinforced polymer (GFRP) composite sandwich beams considering different spans and beam cross sections. The composite sandwich beams with different thicknesses (1, 2, 3, 4, and 5 sandwich layers) have been tested in four-point static flexural test with different shear span to depth ratio (a/d). The a/d ratios showed a direct effect on the flexural and shear behaviour. The capacity of the beam decreased with increasing a/d. Various failure modes were observed including core crushing, core shear, and top skin compression failure. The failure mode map developed based on the experimental finding and analytical prediction indicated that the failure mode is affected by the a/d with the number of glue laminated panels.

  10. Control system of magnetic optical element power supplies for some beam channels

    International Nuclear Information System (INIS)

    The control system of the magnetic optical element power supplies for some beam channels of the IHEP accelerator, based on the micro-computer ''Elektronika-60'' and its software are described. The remote control is supplied with three Multidrop Serial Busses (31 consumer per bus). The number of controlled elements can be increased by adding one or more serial busses

  11. Enhancement of vacuum transmission of intense electron beam through cusp magnetic field using dielectric drift tubes

    Energy Technology Data Exchange (ETDEWEB)

    John, P.I.; Jain, K.K.

    1981-09-01

    A technique for improving the transmission of intense electron beams through cusp magnetic field in vacuum using dielectric drift tubes has been demonstrated. The plasma produced by the material of the dielectric tube increases the transmission efficiency by a factor of four over vacuum values. 15 references, 5 figures.

  12. Electron beam guiding by external magnetic fields in imploded fuel plasma

    Science.gov (United States)

    Johzaki, T.; Sentoku, Y.; Nagatomo, H.; Sunahara, A.; Sakagami, H.; Fujioka, S.; Shiraga, H.; Endo, T.; FIREX project group

    2016-05-01

    For enhancing the core heating efficiency in fast ignition laser fusion, we proposed the fast electron beam by externally-applied the kilo-tesla (kT) class longitudinal magnetic field. We evaluated the imploded core and the magnetic field profiles formed through the implosion dynamics by resistive MHD radiation hydro code. Using those profiles, the guiding effect was evaluated by fast electron transport simulations, which shows that in addition to the feasible field configuration (moderate mirror ratio), the kT-class magnetic field is required at the fast electron generation point. In this case, the significant enhancement in heating efficiency is expected.

  13. Isotope separation in the reflected ion beam in a with a cusp magnetic field

    International Nuclear Information System (INIS)

    The isotope separation in a reflected ion beam injected into a cusp magnetic field has been considered. The magnetic field configuration was formed by two rings with oppositely directed currents. The motion of the particles entering the system and reflected by the increasing magnetic field of the second ring is numerically calculated. A possibility for reflected particles to be separated in the radial direction is shown. This effect allows an annular ion source to be used, which leads to an increase in the total current and the performance of the system

  14. Design and end chamfer simulation of PEFP beam line curved dipole magnets

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying-Shun; YANG Mei; ZHANG Zhuo; CHEN Wan; YIN Bao-Gui; SHI Cai-Tu; KANG Wen

    2011-01-01

    The design, fabrication and field measurement of 11 DC curved dipole magnets for the PEFP Beam Line have been completed. In this paper, a design method for a complex end chamfer using OPERA-3D is proposed. The conventional method for estimating chamfer shape is extended and applied to a curved dipole magnet by a coordinate transformation. Using the interface with CAD software, the complex end chamfer is modeled and fully determined by 3D simulation to meet the field uniformity requirement. The magnetic field measurement results are in good agreement with the simulation. The design considerations, field simulation results, end chamfer development process and measurement results are presented in detail.

  15. Method for separating FEL output beams from long wavelength radiation

    Energy Technology Data Exchange (ETDEWEB)

    Neil, George; Shinn, Michelle D.; Gubeli, Joseph

    2016-04-26

    A method for improving the output beam quality of a free electron laser (FEL) by reducing the amount of emission at wavelengths longer than the electron pulse length and reducing the amount of edge radiation. A mirror constructed of thermally conductive material and having an aperture therein is placed at an oblique angle with respect to the beam downstream of the bending magnet but before any sensitive use of the FEL beam. The aperture in the mirror is sized to deflect emission longer than the wavelength of the FEL output while having a minor impact on the FEL output beam. A properly sized aperture will enable the FEL radiation, which is coherent and generally at a much shorter wavelength than the bending radiations, to pass through the aperture mirror. The much higher divergence bending radiations will subsequently strike the aperture mirror and be reflected safely out of the way.

  16. Ion beams extraction and measurements of plasma parameters on a multi-frequencies microwaves large bore ECRIS with permanent magnets

    International Nuclear Information System (INIS)

    We have developed an all-permanent magnet large bore electron cyclotron resonance ion source (ECRIS) for broad ion beam processing. The cylindrically comb-shaped magnetic field configuration is adopted for efficient plasma production and good magnetic confinement. To compensate for disadvantages of fixed magnetic configuration, a traveling wave tube amplifier (TWTA) is used. In the comb-shaped ECRIS, it is difficult to achieve controlling ion beam profiles in the whole inside the chamber by using even single frequency-controllable TWTA (11-13GHz), because of large bore size with all-magnets. We have tried controlling profiles of plasma parameters and then those of extracted ion beams by launching two largely different frequencies simultaneously, i.e., multi-frequencies microwaves. Here we report ion beam profiles and corresponding plasma parameters under various experimental conditions, dependence of ion beams against extraction voltages, and influence of different electrode positions on the electron density profile.

  17. Production of uniform ion beam of large area in a magnetically-insulatd diode

    International Nuclear Information System (INIS)

    The results of experimental investigation of a magnetically insulated diode generating a powerful ribbon ion beam with 100x10 cm cross section are presented. Modification of the known diode designs allowed to provide the constancy of the electric and magnetic field by the anode length and uniform generation of the ion beam over the larger part of its length. At the same time these measures have decreased considerably electron losses in the anode up to 1-2 A/cm2 that reduces the efficiency of anode plasma formation during the first part of a high-voltage pulse. At 500 kV anode voltage the ion current amplitude is 18 kA, the beam-out energy - 460 J, the efficiency of ion generation - 85%

  18. Optical photography of the magnetically confined anode plasma source for repetitive intense ion beam generation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.J.; Crawford, M.T.; Maenchen, J.E. [Sandia National Labs., Albuquerque, NM (United States)

    1996-12-31

    Time resolved photographs of the visible light from the Magnetically Confined Anode Plasma (MAP) source for Ion Beam Surface Treatment (IBEST) are presented. The MAP source utilizes a fast (2 {micro}s rise time) magnetic field to create a plasma in a radially injected disc shaped gas puff and subsequently inject this plasma into the accelerating gap of a 10-cm-radius high power pulsed extraction ion diode. The 600 kV, 10 kA, 100 ns duration pulse for the beam is generated by a marx generator, cable feed, and linear induction voltage adder. The application of this technology is the generation of repetitively pulsed ion beams for government and industrial treatment of metal and polymer surfaces.

  19. Study of the temporary capture of an electron beam in magnetic mirror configuration

    International Nuclear Information System (INIS)

    A method of injection is studied which is intermediate between the purely transverse injection used in MMII (magnetic mirror device for ion injection) and the longitudinal injection used in CAPEL. The investigation of the conditions of injection of an electron beam has shown the possibility of capturing temporarily a beam approximately 1 cm in width. The mean length of the captured trajectories is about fifty meters. A uniform perturbation of the magnetic field which destroys the axial symmetry does not appreciably modify the length of captured trajectories. This method of injection, which we call 'conical', is interesting because a large proportion of the injected beam is captured (about 80 per cent), and this capture is obtained with injection conditions that are not critical. (author)

  20. Transient Thermal Analysis of Intense Proton Beam Loss on a Kicker Magnet Conductor Plate

    CERN Document Server

    Knaus, P

    2000-01-01

    The Super Proton Synchrotron SPS will be used as injector for the Large Hadron Collider LHC and needs adaptation to meet LHC requirements. The SPS injection kicker magnets MKP will undergo important modifications to comply with the requirements on magnetic field rise-time and ripple. The injection kicker presently installed has a return conductor of beryllium to minimise the risk of metal evaporation from its surface due to heating caused by beam impact. In the context of refurbishing the MKP to satisfy LHC requirements these conductors need replacement, preferably with a less delicate material. This article presents the transient thermal analysis of energy deposition caused by beam loss on the conductor plate. The expected time structure of the beam is taken into account. Simulations comparing different conductor materials have been performed, leading to the result that a significantly cheaper and fully inoffensive titanium alloy can satisfy the needs.

  1. MM-wave emission by magnetized plasma during sub-relativistic electron beam relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, I. A., E-mail: Ivanov@inp.nsk.su; Arzhannikov, A. V.; Burmasov, V. S.; Popov, S. S.; Postupaev, V. V.; Sklyarov, V. F.; Vyacheslavov, L. N. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogova Street, Novosibirsk 630090 (Russian Federation); Burdakov, A. V.; Sorokina, N. V. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20 Karl Marx Avenue, Novosibirsk 630092 (Russian Federation); Gavrilenko, D. E.; Kasatov, A. A.; Kandaurov, I. V.; Mekler, K. I.; Rovenskikh, A. F.; Trunev, Yu. A. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, Novosibirsk 630090 (Russian Federation); Kurkuchekov, V. V.; Kuznetsov, S. A. [Novosibirsk State University, 2 Pirogova Street, Novosibirsk 630090 (Russian Federation); Polosatkin, S. V. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogova Street, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20 Karl Marx Avenue, Novosibirsk 630092 (Russian Federation)

    2015-12-15

    There are described electromagnetic spectra of radiation emitted by magnetized plasma during sub-relativistic electron beam in a double plasma frequency band. Experimental studies were performed at the multiple-mirror trap GOL-3. The electron beam had the following parameters: 70–110 keV for the electron energy, 1–10 MW for the beam power and 30–300 μs for its duration. The spectrum was measured in 75–230 GHz frequency band. The frequency of the emission follows variations in electron plasma density and magnetic field strength. The specific emission power on the length of the plasma column is estimated on the level 0.75 kW/cm.

  2. Hierarchy of instabilities for two counter-streaming magnetized pair beams

    CERN Document Server

    Bret, Antoine

    2016-01-01

    The instabilities triggered when two counter-streaming pair beams collide are analyzed. A guiding magnetic field is accounting for, while both beams are considered identical and cold. The instability analysis is conducted over the full \\textbf{k}-spectrum, allowing to derive the hierarchy map of the dominant unstable modes, in terms of the initial beams energy $\\gamma_0$ and a magnetic field strength parameter $\\Omega_B$. Four different regions of the $(\\Omega_B,\\gamma_0)$ phase space are identified, each one governed by a different kind of mode. The analysis also unravels the existence of a "triple point", where 3 different modes grow exactly the same rate. A number of analytical expressions can be derived, either for the modes growth-rates, or for the frontiers between the 4 regions.

  3. Buildup of electrons with hot electron beam injection into a homogeneous magnetic field

    International Nuclear Information System (INIS)

    The injection of the monoenergetic beam of electrons into the vacuum drift channel under the conditions when the beam current exceeds a certain threshold value involves a virtual cathode creation. The process of virtual cathode creation leads to an exchange of one-fluid movement of beam particles to three-fluid one corresponding to incident, reflected and passed through anticathode beam particles. For the monoenergetic beam case when the velocity spread Δvdr (vdr is the beam drift velocity), the beam instability was predicted in theory and was observed in experiment. Meanwhile, the injection in the drift space of the 'hot' beam having finite spread in velocities may be accompanied not only by the reflection of particles if their velocity v1/2 (where φ is the electrostatic potential dip value, e and m are the electron charge and mass, respectively), but also the mutual Coulomb scattering of incident and reflected electrons. The scattering process leads in its turn to appearance of viscosity forces and to trapping of a part of beam electrons into the effective potential well formed by electrostatic potential dip and the viscous force potential. The interaction of travelling and trapped particles may occur even at the stage preceding the virtual electrode formation and it may influence the process of its appearance and also the current flow through the drift space. In this report there are described the experimental results on accumulation of electrons when electron beam propagates in vacuum and has a large spread in particle velocities Δvdr in the homogeneous longitudinal magnetic field when ωpeHe where ωpe is the electron Langmuir frequency of beam electrons, ωHe is the electron cyclotron frequency. (author) 6 refs., 2 figs

  4. Precision of intense electron beams transported in vacuum by applied magnetic field

    International Nuclear Information System (INIS)

    Measurements of the spatial distribution of the beam current density in the GESA-facilities [1] shows that the current density oscillates in time although the total beam current is stable. To investigate the nature of these oscillations results from different diagnostics for current and power density measurements have been analyzed (Faraday cups, small metal plates, x-ray detectors, etc.). It was found that oscillations of the beam current density are due to spatial movement (rotation) of the whole beam. The amplitude and appearance of this beam precision strongly depends on magnitude and distribution of the applied magnetic field and also on the target material. The onset of oscillations occurred several μs after the beginning of the pulse. The time of oscillations onset depends on the target material. The period of the oscillation is practically independent of the magnetic field magnitude and distribution and target material, and is always equal to about 1.5 μs. In this paper we discuss the results of current density and x-ray measurements and the possible reasons for the appearance of beam precision during the pulse

  5. Beam dynamics performances and applications of a low-energy electron-beam magnetic bunch compressor

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, C.R., E-mail: cprokop@gmail.com [Northern Illinois Center for Accelerator and Detector Development and Department of Physics, Northern Illinois University, DeKalb, IL 60115 (United States); Piot, P. [Northern Illinois Center for Accelerator and Detector Development and Department of Physics, Northern Illinois University, DeKalb, IL 60115 (United States); Accelerator Physics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Carlsten, B.E. [Acceleration Operations and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Church, M. [Accelerator Division, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

    2013-08-11

    Many front-end applications of electron linear accelerators rely on the production of temporally compressed bunches. The shortening of electron bunches is often realized with magnetic bunch compressors located in high-energy sections of accelerators. Magnetic compression is subject to collective effects including space charge and self interaction via coherent synchrotron radiation. In this paper we explore the application of magnetic compression to low-energy (∼40MeV), high-charge (nC) electron bunches with low normalized transverse emittances (<5μm). -- Author-Highlights: • We explore the viability of bunch compression at low energies and high charges. • Simulations for bunch charges ranging from 20-pC to 3.2-nC are presented. • Performed in the context of Fermilab's Advanced Superconducting Test Accelerator. • Codes including space charge and coherent synchrotron radiation are benchmarked. • Under-compression and low charges greatly reduced emittance growth.

  6. Beam dynamics performances and applications of a low-energy electron-beam magnetic bunch compressor

    International Nuclear Information System (INIS)

    Many front-end applications of electron linear accelerators rely on the production of temporally compressed bunches. The shortening of electron bunches is often realized with magnetic bunch compressors located in high-energy sections of accelerators. Magnetic compression is subject to collective effects including space charge and self interaction via coherent synchrotron radiation. In this paper we explore the application of magnetic compression to low-energy (∼40MeV), high-charge (nC) electron bunches with low normalized transverse emittances (<5μm). -- Author-Highlights: • We explore the viability of bunch compression at low energies and high charges. • Simulations for bunch charges ranging from 20-pC to 3.2-nC are presented. • Performed in the context of Fermilab's Advanced Superconducting Test Accelerator. • Codes including space charge and coherent synchrotron radiation are benchmarked. • Under-compression and low charges greatly reduced emittance growth

  7. Dissipative instability of an intense e-beam in finite external magnetic field

    International Nuclear Information System (INIS)

    Full text: Microinstabilities, along with large-scale perturbations, play an important role in devices for controlled fusion. Last few decades substantial efforts have been made to understand microinstabilities in fusion plasma. They are accompanied by plasma heating and diffusion and can also greatly enhance plasma transport across magnetic-field lines. Plasma anomalous resistance is also being thought to be connected with microinstabilities. Most frequently encountered microinstabilities are that in current carrying plasma and in electron beams. The physical nature of intense e-beam instability in plasma significantly depends on many factors. Most important of them are: (i) beam current value (e.g. underlimiting) or overlimiting), (ii) level of overlap of the beam and the plasma fields, and (iii) dissipation. Dissipation plays an important role, particularly in dense fusion plasma. Dissipation of high level transforms instability to that of dissipative type. This takes place due to negative energy wave (NEW) of the beam space charge. Dissipation serves as a channel for energy withdrawal for excitation of this wave. Dissipative instabilities are coupled with resistive wall modes. On the other hand excitation NEW means coupling of dissipative and space charge phenomena. The influence of dissipation on various beam instabilities was considered. New type dissipative beam instability is substantiated. Its growth rate has more critical (as compared to conventional) dependence on dissipation. Consideration of the instability in infinite external magnetic field essentially simplifies the analysis. But in many cases such consideration is undesirable and even inappropriate. This investigation substantiates the new type of dissipative streaming instability for finite external magnetic field. The investigation also states that the evolution of the instability in space and time is governed by partial differential equation of second order independently on geometry and specific

  8. A compact broadband ion beam focusing device based on laser-driven megagauss thermoelectric magnetic fields

    International Nuclear Information System (INIS)

    Ultra-intense lasers can nowadays routinely accelerate kiloampere ion beams. These unique sources of particle beams could impact many societal (e.g., proton-therapy or fuel recycling) and fundamental (e.g., neutron probing) domains. However, this requires overcoming the beam angular divergence at the source. This has been attempted, either with large-scale conventional setups or with compact plasma techniques that however have the restriction of short (<1 mm) focusing distances or a chromatic behavior. Here, we show that exploiting laser-triggered, long-lasting (>50 ps), thermoelectric multi-megagauss surface magnetic (B)-fields, compact capturing, and focusing of a diverging laser-driven multi-MeV ion beam can be achieved over a wide range of ion energies in the limit of a 5° acceptance angle

  9. A compact broadband ion beam focusing device based on laser-driven megagauss thermoelectric magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Albertazzi, B., E-mail: bruno.albertazzi@polytechnique.edu [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); INRS-EMT, Varennes, Québec J3X 1S2 (Canada); Graduate School of Engineering, Osaka University, Suita, Osaka 565-087 (Japan); D' Humières, E. [CELIA, Universite de Bordeaux, Talence 33405 (France); Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); Lancia, L.; Antici, P. [Dipartimento SBAI, Universita di Roma “La Sapienza,” Via A. Scarpa 16, 00161 Roma (Italy); Dervieux, V.; Nakatsutsumi, M.; Romagnani, L.; Fuchs, J., E-mail: Julien.fuchs@polytechnique.fr [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Böcker, J.; Swantusch, M.; Willi, O. [Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität, Düsseldorf D-40225 (Germany); Bonlie, J.; Cauble, B.; Shepherd, R. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Breil, J.; Feugeas, J. L.; Nicolaï, P.; Tikhonchuk, V. T. [CELIA, Universite de Bordeaux, Talence 33405 (France); Chen, S. N. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Sentoku, Y. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); and others

    2015-04-15

    Ultra-intense lasers can nowadays routinely accelerate kiloampere ion beams. These unique sources of particle beams could impact many societal (e.g., proton-therapy or fuel recycling) and fundamental (e.g., neutron probing) domains. However, this requires overcoming the beam angular divergence at the source. This has been attempted, either with large-scale conventional setups or with compact plasma techniques that however have the restriction of short (<1 mm) focusing distances or a chromatic behavior. Here, we show that exploiting laser-triggered, long-lasting (>50 ps), thermoelectric multi-megagauss surface magnetic (B)-fields, compact capturing, and focusing of a diverging laser-driven multi-MeV ion beam can be achieved over a wide range of ion energies in the limit of a 5° acceptance angle.

  10. Beam optics optimization in the KEK digital accelerator LEBT considering the effect of remnant magnetic fields

    International Nuclear Information System (INIS)

    KEK Digital Accelerator is a compact induction synchrotron which sets little limitation on the charged ion beam's species and injection velocities. Extracted from an Electron Cyclotron Resonance Ion Source (ECRIS), the ion beam (A/Q=2, 4) is transported though Low Energy Beam Transport (LEBT) line before injected into the ring for acceleration. As the velocity is relatively small (β∼10-2), effects originating from remnant fields in different magnets along the LEBT line should be taken into account for orbit correction and optics optimization. With the help of online wire monitors, the following goals have been realized: (1) Beam orbit correction; (2) Twiss parameters and emittance at a chosen position are estimated; (3) beta function and injection focusing mismatch are studied with fitted results. These processes and results are presented and discussed in this paper. (author)

  11. Use of Superimposed Alternating Currents in Quadrupoles to Measure Beam Position with Respect to their Magnetic Centre

    CERN Document Server

    Marks, N

    2000-01-01

    The positional stability of the electron beam in a modern state-of-the-art synchrotron radiation source is critical, as the many experimental users require consistency in the position and dimensions of the incoming photon beams which are incident on their experimental samples. At the Daresbury Synchrotron Radiation Source (SRS), inaccuracies in the measurements of the positions of both beam position monitors and the lattice quadrupoles can be overcome by measuring the position of the electron beam with respect to the magnetic centres of the quadrupoles. This was achieved by superimposing an alternating ('ripple') current on the direct current excitation of a single lattice quadrupole and examining the resulting beam oscillations at remote positions in the storage ring. If the electron beam is then subjected to a local distortion at the position of this quadrupole, the amplitude of the beam oscillation induced by the superimposed current is minimised (nominally zero) when the beam is at the quadrupole's magnet...

  12. Beam dynamics with new booster dipoles

    International Nuclear Information System (INIS)

    New bending magnets are being designed for the booster synchrotron at RRCAT, Indore with the same effective length and field which will be installed in the existing ring with the same configuration of drifts and quadrupole magnets. Presently sector type dipoles are in use. It is easier to fabricate parallel edge (rectangular type) dipoles but the beam optics gets modified due to edges which provide additional focusing. The effect on tune point can be corrected using two quadrupole families. Studies indicate that the beam emittance is lower in the optics with rectangular type dipoles but the beam injection and extraction are more difficult. In this paper, the beam optics, beam emittance, injection and extraction with two configurations of the dipole magnets are compared. (author)

  13. Intense heavy-ion beam transport with electric and magnetic quadrupoles

    Energy Technology Data Exchange (ETDEWEB)

    Fessenden, T.J. [Lawrence Berkeley National Lab., CA (United States). Accelerator and Fusion Research Center; Barnard, J.J.; Cable, M.D.; Deadrick, F.J.; Eylon, S.; Nelson, M.B.; Sangster, T.C. [Lawrence Livermore National Lab., CA (United States); Hopkins, H.S. [Univ. of California, Berkeley, CA (United States)

    1995-08-01

    As part of the small induction recirculator development at LLNL, the authors are testing an injector and transport line that delivers 4 {micro}s beams of potassium with repetition rates up to 10 Hz at a nominal current of 2 mA. The normalized K-V equivalent emittance of the beams is near 0.02 {pi} mm-mrad and is mostly determined by the temperature of the source (0.1 eV). K{sup +} ions generated at 80 keV in a Pierce diode are matched to an alternating gradient transport line by seven electric quadrupoles. Two additional quads have been modified to serve as two-axis steerers. The matching section is followed by a transport section comprised of seven permanent magnet quadrupoles. Matching to this section is achieved by adjusting the voltages on the electric quadrupoles to voltages calculated by an envelope matching code. Measurements of beam envelope parameters are made at the matching section entrance and exit as well as at the end of the permanent magnet transport section. Beam current waveforms along the experiment are compared with results from a one-dimension longitudinal dynamics code. Initial experiments show particle loss occurring at the beam head as a result of overtaking. The apparatus is also being used for the development of non or minimally intercepting diagnostics for future recirculator experiments. These include capacitive monitors for determining beam line-charge density and position in the recirculator; flying wire scanners for beam position; and gated TV scanners for measuring beam profiles and emittance.

  14. Modification of magnetic anisotropy in metallic glasses using high-energy ion beam irradiation

    Indian Academy of Sciences (India)

    K V Amrute; U R Mhatre; S K Sinha; D C Kothari; R Nagarajan; D Kanjilal

    2002-05-01

    Heavy ion irradiation in the electronic stopping power region induces macroscopic dimensional change in metallic glasses and introduces magnetic anisotropy in some magnetic materials. The present work is on the irradiation study of ferromagnetic metallic glasses, where both dimensional change and modification of magnetic anisotropy are expected. Magnetic anisotropy was measured using Mössbauer spectroscopy of virgin and irradiated Fe40Ni40B20 and Fe40Ni38Mo4B18 metallic glass ribbons. 90 MeV 127I beam was used for the irradiations. Irradiation doses were 5 × 1013 and 7.5 × 1013 ions/cm2. The relative intensity ratios 23 of the second and third lines of the Mössbauer spectra were measured to determine the magnetic anisotropy. The virgin samples of both the materials display in-plane magnetic anisotropy, i.e., the spins are oriented parallel to the ribbon plane. Irradiation is found to cause reduction in magnetic anisotropy. Near-complete randomization of magnetic moments is observed at high irradiation doses. Correlation is found between the residual stresses introduced by ion irradiation and the change in magnetic anisotropy.

  15. Operation beam switching at the FAKEL accelerator of the Kurchatov's Institute for Atomic Energy

    International Nuclear Information System (INIS)

    The results of operative beam switching system development for the FAKEL accelerator with five electron-optical channels are presented. A single there structure is used in the pulsed magnet. A pulse generator is based on the method of multiplication in a capacitor. The pulse magnet with 3 deg bending angle is arranged at the accelerator axis in front of the magnet with a constant field. The magnetic screen is arranged inside the magnet with a constant field. An electron beam is bended from the accelerator axis, when current pulse is applied to the magnet, and hits the field of the permanent magnet, but during current pulse it hits the magnetic screen. 7 refs.; 2 figs

  16. Bending instability characteristics of double-walled carbon nanotubes

    OpenAIRE

    Wang, Q.; Hu, T.; Chen, G.; Jiang, Q.

    2005-01-01

    The bending instability characteristics of double-walled carbon nanotubes (DWNTs) of various configurations are studied using a hybrid approach in which the deformation-induced increase of the intratube interaction energy is modeled with the bending deformation energy using the elastic theory of beams. The intertube interaction energy is calculated using the van der Waals interatomic potential. This study shows that the bending instability may take place through the formation of a single kink...

  17. Silicon crystal under bending

    International Nuclear Information System (INIS)

    The mechanical behavior of a silicon crystal under bending is investigated. For a crystal of length 30 mm and thickness 3 mm, to achieve the specified bend angle of 0.64 mrad, the appropriate angle of the aluminum punches is 0.96 mrad

  18. Performance of magnetically-injected-plasma opening switches on the particle beam fusion accelerator 2

    International Nuclear Information System (INIS)

    Plasma opening switch (POS) experiments have been performed on the PBFA II ion beam accelerator to develop a switch which will provide voltage and power gain to an applied-B lithium ion diode. These experiments have successfully coupled power to electron and ion beam diodes using a Magnetically-Injected-Plasma (MIP) POS. Carbon plasma with electron densities of 1 x 1012 to 2 x 1013 /cm3 have been injected from the anode into the 8 cm gap of the 20-ohm Magnetically-Insulated-Transmission Line (MITL) of PBFA II along a Br,z magnetic field. The MIP switch uses the inertia of the plasma to keep the switch closed and the magnetic pressure of Bθ from the conduction current to open the switch. The configuration of the injecting magnetic field and the plasma source has a significant effect on the efficiency of coupling power to high impedance loads. Plasma near the center of the injecting magnetic field limits the opening impedance of the switch and subsequently the power delivered to the load. The axial location of the switch with respect to the load has also been identified as a critical parameter in increasing the coupling efficiency. A length of 10 to 20 cm of MITL between the POS and the load has increased the power delivered to the load. Data on switch performance with high impedance loads and factors which improved performance are discussed

  19. Mechanical design and development of analyzing magnet for the RIB charge breeder beam line

    International Nuclear Information System (INIS)

    An iron dominated analyzing magnet of uniform peak field 0.6 T has been developed for Radioactive Ion Beam (RIB) charge breeder beam line at VECC, Kolkata. It has two room temperature coils made of copper having channels for passage of cooling water. The other important parts of the magnet includes two yokes, two poles, vacuum chamber, view port, iron plates and the support structures. The most important properties of magnets designed and fabricated for this application is the need for high field quality. The magnet assembly has got overall dimensions of 1.1 metres x 0.91 metres x 0.63 metres and the required field uniformity is 6 x 10-4 over pole width of ± 2.5 cm. The most critical parameter that has to be maintained to achieve the desired magnetic field is the pole gap of 80 ± 0.25 rom.This paper describes in detail about the mechanical design, coil cooling analysis, development and assembly of this magnet. (author)

  20. Multiturn septum magnets for proton beam extraction from the IHEP accelerator

    International Nuclear Information System (INIS)

    Structure of multiturn septum magnet for he systems of proton beam extraction from the IHEP accelerator is described. Excitation coil, magnet core and all communications are located outside the accelerator vacuum volume. The magnet is characterized by a low gas release to the vacuum volume under the residual gas pressures of up to 1x10 -8Pa. The transition from monoturn excitation coil to multiturn one allowed one to decrease the value of necessary current and thus to reduce the energy loss in the bus duct from the power supply source to septum magnet. This allows one to increase the duration of slow proton extraction under the same power consumption. For example, after transition to two- and four-turn septum magnets the slow extraction duration can be increased up to two seconds, i.e.-doubled, which opens up a possibility to organize the particle beam extraction along two separate transport channels. By the present time the septum magnet has made 300000 cycles within the framework of physical experiments

  1. Power supplies for IRFEL beam transport line magnets

    International Nuclear Information System (INIS)

    The Infrared Free Electron Laser (IRFEL) is being developed at RRCAT. Current regulated, dc power supplies are required for various electromagnets in its beam transport line. These are rated for 13 A and 15 V (maximum) with output current stability of ±100 ppm. In all, 60 power supplies have been developed, including the spare ones. In order to facilitate timely development of these power supplies, uniform power converter scheme for all power supplies has been followed and all associated low- power electronics, e.g. sensing, fault handling, auxiliary power sources, handling remote interface have been standardized. The topology used in these power supplies is two-switch forward converter operating with variable frequency PWM (VFPWM) control in the range from 20 kHz to 100 kHz. After the design, simulation studies, prototype development and rigorous testing of the prototype at RRCAT, the bulk production, testing and evaluation was carried out with the involvement of industry. This paper describes power supply design principles, highlights its salient features, shares the development experience and discusses the test results. (author)

  2. Development of a magnetic beam guiding system for tumor-specific radiotherapy using heavy, charged particles

    International Nuclear Information System (INIS)

    An active, magnetic beam guiding system was developed and tested for the purpose of enhanced and tumor-specific irradiation of irregularly shaped target volumina. Combining intensity-controlled wobbling in rapidly changing magnetic fields with the heavy-ion synchrotron's capacity of fast energy variation achieved a new technique allowing good range modulation. This technique allows the calculated dose distribution to be exactly matched to target contours, and at the same time guarantees best possible quality of the radiation beam, since there is no need for use of mechanical beam shaping members. The components of the scanning system and a specifically designed instrumentation and control concept for this configuration were integrated into the synchrotron's control system, so that there is now a system available offering free selection of beam characteristics combined with energy variation along with the pulsed operation of the accelerator. The system was tested at the biophysical measuring unit of the GSI implementing an elaborated irradiation method at this unit equipped with tools for physico-technical irradiation planning and performance. Methods were designed and tested for optimizing the beam path within a given contour, the optimization taking into account the effects of transmission functions of the scanner components on the results of radiation treatments. (orig.)

  3. Achromatic beam transport of High Current Injector

    Science.gov (United States)

    Kumar, Sarvesh; Mandal, A.

    2016-02-01

    The high current injector (HCI) provides intense ion beams of high charge state using a high temperature superconducting ECR ion source. The ion beam is accelerated upto a final energy of 1.8 MeV/u due to an electrostatic potential, a radio frequency quadrupole (RFQ) and a drift tube linac (DTL). The ion beam has to be transported to superconducting LINAC which is around 50 m away from DTL. This section is termed as high energy beam transport section (HEBT) and is used to match the beam both in transverse and longitudinal phase space to the entrance of LINAC. The HEBT section is made up of four 90 deg. achromatic bends and interconnecting magnetic quadrupole triplets. Two RF bunchers have been used for longitudinal phase matching to the LINAC. The ion optical design of HEBT section has been simulated using different beam dynamics codes like TRACEWIN, GICOSY and TRACE 3D. The field computation code OPERA 3D has been utilized for hardware design of all the magnets. All the dipole and quadrupole magnets have been field mapped and their test results such as edge angles measurements, homogeneity and harmonic analysis etc. are reported. The whole design of HEBT section has been performed such that the most of the beam optical components share same hardware design and there is ample space for beam diagnostics as per geometry of the building. Many combination of achromatic bends have been simulated to transport the beam in HEBT section but finally the four 90 deg. achromatic bend configuration is found to be the best satisfying all the geometrical constraints with simplified beam tuning process in real time.

  4. 4He2+ and H2+ ion beam separation on ''Sokol'' IBA facility

    International Nuclear Information System (INIS)

    Two separation methods of 4He2+ and H2+ ion beams have been tested on ''Sokol'' IBA facility of NSC KIPT: use of existing beam-bending magnet and electrostatic analyzer, dissociation of H2+ ions when the beam passes through the carbon film. It is shown that these methods allow to decrease essentially the H2+ ion content in the 4He2+ beam.

  5. Simulation of Beam Envelop Transport in Medium Energy of Ion Accelerator

    International Nuclear Information System (INIS)

    Simulation of beam envelop transport in medium energy of ion accelerator (Tandem) using beam particle optic laboratory program of version 1.1.1 has been carried out. The accelerated ion beam are hydrogen and nitrogen ion, which leave the SNICS ion source within X and Y direction of initial radius of 1 cm respectively and having vertical and horizontal degree of emittance of 16.4 π mm mRad respectively. The simulation is completed twice, i.e. for negative ion is made on low energy of accelerator and for positive ion is arranged on medium energy of accelerator. To keep the beam envelop radius of simulation result of low energy simulation, the fitting program is used with four einzel lenses. two bending magnet and one electrostatic quadrupole. On the first einzel lens the obtained focus length is 70 cm, the bending magnetic field as 3.378 kG, the angle of bending as 30o and the curvature radius as 0.533 m. On the second einzel lens the obtained focus length is 24 cm with bending beam angle as 90o, the bending magnetic field obtained as 3.89 kG and the obtained curvature radius is 0.457 m. The beam envelop is then entered into einzel lens with focus length of 30 cm and it then focused by using electrostatic quadrupole with coefficient quadrupole 54.25 and -89.51 and electrode length of 0.07 m. Before the beam envelop entered accelerator tube, it pass the einzel lens with focus length of 26 cm. To accelerate positive ion of the beam envelop simulation at medium energy the -1.5 MV voltage of accelerator tube is used, then the beam passes through a bending magnet and a magnetic quadrupole. Beam envelop transport by using fitting method obtained a bending magnet 15o and a magnetic field strength 3.997 kG. While at the electrode length of 0.14 m of quadrupole magnetic doublet, it was obtained the magnetic field strengths of 3.2 kG and -3.4 kG. (author)

  6. Coupling between eddy current and deflection in cantilevered beams in magnetic fields

    International Nuclear Information System (INIS)

    Experiments were performed to investigate the coupling between eddy currents and deflection in cantilevered beams in longitudinal and transverse magnetic fields. This coupling effect reduces the current, deflection, and material stress to levels far less severe than would be predicted if coupling is disregarded. The experiments were conducted using the FELIX (Fusion ELectromagnetic Induction experiment) facility at the Argonne National Laboratory. The beams, which provide a simple model for the limiter blades in a tokamak fusion reactor, are subjected to crossed time-varying and constant magnetic fields. The time-varying field simulates the decaying field during a plasma disruption and the constant field models the toroidal field. Several test pieces are employed to allow variations in thicknesses and mechanical and electrical properties. Various magnetic field levels and decay time constants of time-varying are used to study the extent of the coupling from weak to strong coupling. The ratios of constant field to time-varying field are kept in the range from 10:1 to 20:1 as would be appropriate to tokamak limiters. Major parameters measured as functions of time are beam deflection, measured with an electro-optical device; total circulating current, measured with a Rogowski coil; strain recorded by strain gauges; and magnetic fields measured with Hall probes

  7. Wide range pure bending strains of Nb3Sn wires

    International Nuclear Information System (INIS)

    Pure bending behavior of Nb3Sn wire over a wide range of bending has been characterized. A previously developed test device designed to apply variable bending strains to Nb3Sn strands using a beam style sample holder was used. Based on finite element and experimental investigations, two sample holder beams were developed to cover pure bending strains up to 1.25% for ITER-type Nb3Sn wires. These newly designed beams were optimized to apply consistent and uniform pure bending strains to Nb3Sn strands over the entire bending range. Their performance was evaluated by testing two ITER-type Nb3Sn wires including one internal tin and one bronze route. The internal tin strands experienced around 55% critical current degradation at 1.25% bending strain while the critical current of the bronze route strands were only reduced by 40%. Upon removal of the bending load, the internal tin wires experienced significant permanent degradation whereas the bronze route wires were completely reversible. These critical current results were evaluated and explained using an existing integrated model accounting for neutral axis shift, current transfer length, filament breakage and uniaxial strain release under pure bending loads. (paper)

  8. Irradiation creep of stainless steel in bending

    International Nuclear Information System (INIS)

    The development is described of a test to measure irradiation enhanced creep in bending of 20% cold-worked Type-316 stainless steel. The test will be irradiated in the experimental fast reactor EBR-II. The rationale used in design selection is described. The selected beam designs, the supportive tests in other stress states and the measurement techniques are described in detail. (Auth.)

  9. Irradiation creep of stainless steel in bending

    International Nuclear Information System (INIS)

    The development is described of a test to measure irradiation enhanced creep in bending of 20% cold-worked Type-316 stainless steel. The test will be irradiated in the experimental fast reactor EBR-II. The rationale used in design selection is described. The selected beam designs, the supportive tests in other stress states and the measurement techniques are described in detail

  10. 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.

  11. Formation and transport of slow positron beam in magnetic field with {sup 22}Na

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Takayoshi; Fujita, Hirohumi; Yamada, Masaki; Nunogaki, Masanobu; Honda, Yoshihide; Isoyama, Goro [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research

    1996-03-01

    The {beta}{sup +} particles emitted from {sup 22}Na have been formed to a slow positron beam by moderating them at the surface of a W-foil and then transported in a curved magnetic field to separate the beam from the {gamma}-rays. The curvature drift has been compensated by the E x B drift due to the auxidially electrodes inserted in that region. More than 1.1 x 10{sup 4} positrons/sec have been confirmed to be transported through the curved field without the drift motion. (author).

  12. In situ magnetic compensation for potassium spin-exchange relaxation-free magnetometer considering probe beam pumping effect

    International Nuclear Information System (INIS)

    A novel method to compensate the residual magnetic field for an atomic magnetometer consisting of two perpendicular beams of polarizations was demonstrated in this paper. The method can realize magnetic compensation in the case where the pumping rate of the probe beam cannot be ignored. In the experiment, the probe beam is always linearly polarized, whereas, the probe beam contains a residual circular component due to the imperfection of the polarizer, which leads to the pumping effect of the probe beam. A simulation of the probe beam's optical rotation and pumping rate was demonstrated. At the optimized points, the wavelength of the probe beam was optimized to achieve the largest optical rotation. Although, there is a small circular component in the linearly polarized probe beam, the pumping rate of the probe beam was non-negligible at the optimized wavelength which if ignored would lead to inaccuracies in the magnetic field compensation. Therefore, the dynamic equation of spin evolution was solved by considering the pumping effect of the probe beam. Based on the quasi-static solution, a novel magnetic compensation method was proposed, which contains two main steps: (1) the non-pumping compensation and (2) the sequence compensation with a very specific sequence. After these two main steps, a three-axis in situ magnetic compensation was achieved. The compensation method was suitable to design closed-loop spin-exchange relaxation-free magnetometer. By a combination of the magnetic compensation and the optimization, the magnetic field sensitivity was approximately 4 fT/Hz1/2, which was mainly dominated by the noise of the magnetic shield

  13. Intense beams from gases generated by a permanent magnet ECR ion source at PKU.

    Science.gov (United States)

    Ren, H T; Peng, S X; Lu, P N; Yan, S; Zhou, Q F; Zhao, J; Yuan, Z X; Guo, Z Y; Chen, J E

    2012-02-01

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O(+), H(+), and D(+) to N(+), Ar(+), and He(+). Up to now, about 120 mA of H(+), 83 mA of D(+), 50 mA of O(+), 63 mA of N(+), 70 mA of Ar(+), and 65 mA of He(+) extracted at 50 kV through a φ 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 π mm mrad. Tungsten samples were irradiated by H(+) or He(+) beam extracted from this ion source and H∕He holes and bubbles have been observed on the samples. A method to produce a high intensity H∕He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He(+) beam injector for coupled radio frequency quadruple and SFRFQ cavity, He(+) beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He(+) beam. PMID:22380337

  14. Intense beams from gases generated by a permanent magnet ECR ion source at PKU

    Energy Technology Data Exchange (ETDEWEB)

    Ren, H. T.; Chen, J. E. [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); Peng, S. X.; Lu, P. N.; Yan, S.; Zhou, Q. F.; Zhao, J.; Yuan, Z. X.; Guo, Z. Y. [SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

    2012-02-15

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O{sup +}, H{sup +}, and D{sup +} to N{sup +}, Ar{sup +}, and He{sup +}. Up to now, about 120 mA of H{sup +}, 83 mA of D{sup +}, 50 mA of O{sup +}, 63 mA of N{sup +}, 70 mA of Ar{sup +}, and 65 mA of He{sup +} extracted at 50 kV through a {phi} 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 {pi} mm mrad. Tungsten samples were irradiated by H{sup +} or He{sup +} beam extracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He{sup +} beam injector for coupled radio frequency quadruple and SFRFQ cavity, He{sup +} beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He{sup +} beam.

  15. Model Magnet Development of D1 Beam Separation Dipole for the HL-LHC Upgrade

    CERN Document Server

    Nakamoto, T; Kawamata, H; Enomoto, S; Higashi, N; Idesaki, A; Iio, M; Ikemoto, Y; Iwasaki, R; Kimura, N; Ogitsu, T; Okada, N; Sasaki, K I; Yoshida, M; Todesco, E

    2015-01-01

    KEK has been conducting the design study of the beam separation dipole magnet, D1, for the High Luminosity LHC (HL-LHC) upgrade within a framework of the CERN-KEK collaboration. The D1 magnet has a coil aperture of 150 mm using Nb-Ti superconducting cable and the nominal dipole field of 5.6 T can be generated at 12 kA and 1.9 K. A field integral of 35 T·m is required. The development of the 2-m-long model magnet has been started since May 2013. This paper describes the development status of the short model magnet as well as advancement of the fundamental design studies.

  16. Molecular beam epitaxy grown (Ga,Mn)(As,P) with perpendicular to plane magnetic easy axis

    International Nuclear Information System (INIS)

    We present an experimental investigation of the magnetic, electrical, and structural properties of Ga0.94Mn0.06As1-yPy layers grown by molecular beam epitaxy on GaAs substrates for y≤0.3. X-ray diffraction measurements reveal that the layers are under tensile strain, which gives rise to a magnetic easy axis perpendicular to the plane of the layers. The strength of the magnetic anisotropy and the coercive field increases as the phosphorous concentration is increased. The resistivity of all samples shows metallic behavior with the resistivity increasing as y increases. These materials will be useful for studies of micromagnetic phenomena requiring metallic ferromagnetic material with perpendicular magnetic anisotropy

  17. Properties and parameters of the electron beam injected into the mirror magnetic trap of a plasma accelerator

    Science.gov (United States)

    Andreev, V. V.; Novitsky, A. A.; Vinnichenko, L. A.; Umnov, A. M.; Ndong, D. O.

    2016-03-01

    The parameters of the injector of an axial plasma beam injected into a plasma accelerator operating on the basis of gyroresonance acceleration of electrons in the reverse magnetic field are determined. The trapping of the beam electrons into the regime of gyroresonance acceleration is numerically simulated by the particle- in-cell method. The optimal time of axial injection of the beam into a magnetic mirror trap is determined. The beam parameters satisfying the condition of efficient particle trapping into the gyromagnetic autoresonance regime are found.

  18. Determination of reversed plasma current profile from the experiments of magnetic compression of a microsecond relativistic electron beam

    International Nuclear Information System (INIS)

    Measuring technique for distribution of reversed plasma current in relativistic electron beam crosssection which is based on velocity measurement of azimutj rotation of the beam spreading within the external magnetic field is realized experimentally. Measurements of reversed current profile are carried out during the experiments on magnetic compression of powerful microsecond relativistic electron beam (1 MV, 75 kA, 4μs, 100kj, 5 kA/cm2). Data on the level of beam charged neutralization at gas lowpressure in drift chamber are obtained

  19. Stress analysis of the FAIR Super-FRS low energy beam line quadrupole magnet

    International Nuclear Information System (INIS)

    The Super-FRS is a large acceptance superconducting fragment separator with three branches serving different experimental areas. Low Energy Branch of the main separator delivers secondary beams of low energy beams and thus the range of straggling of hot fragments is reduced. The quadrupole magnets of the Low Energy Branch is a super-ferric magnet having a field gradient of 8.0 T/m. It has usable aperture of ±190 mm in horizontal direction and ±120 mm in vertical dimension. It has a pole tip radius of 250 mm. The Lorentz forces on the coil are non-uniform and must be supported to prevent movement and subsequent quench. Moreover the magnets will be assembled at room temperature and will undergo thermal contraction during operation at liquid helium temperature Therefore it is very important to perform detailed stress analysis of the magnet to evaluate thermal as well as electromagnetic stresses and deformation developed in the coil, coil support structures, and iron during cool down and coil excitation. This paper describes the three dimensional stress analysis of the magnet assembly. (author)

  20. Magnetic modification at sub-surface of FeRh bulk by energetic ion beam irradiation

    Science.gov (United States)

    Koide, T.; Uno, H.; Sakane, H.; Sakamaki, M.; Amemiya, K.; Iwase, A.; Matsui, T.

    2015-05-01

    Ferromagnetic layered structure has been made at sub-surface of the antiferromagnetic FeRh bulk samples by high energy He ion beam irradiation. In accordance with the Transport of Ions in Matter simulation, such ion beam can effectively deposit the elastic collision energy in several μm regions in the depth from the surface. Measurement with a superconducting quantum interference device reveals the irradiated samples to be ferromagnetic. Assuming that only the part the energy deposited can be modified to be ferromagnetic, the corresponding irradiation induced magnetization is consistent with the data that we previously reported. On the other hand, the X-ray magnetic circular dichroism (XMCD) spectra for the irradiated samples are totally unchanged as those for the unirradiated samples. Since XMCD signal in total emission yield method is considered to be surface sensitive with a typical probing depth of several nm, the surface magnetic state is maintained to be antiferromagnetic. By utilizing these phenomena, three-dimensional magnetic patterning of FeRh can be realized, which may potentially be used for future magnetic exchange device application such as nano-scale sensors and memories.

  1. Magnetic modification at sub-surface of FeRh bulk by energetic ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Koide, T.; Iwase, A. [Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Uno, H.; Sakane, H. [S. H. I. Examination and Inspection, Ltd., Saijo, Ehime 799-1393 (Japan); Sakamaki, M.; Amemiya, K. [High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Matsui, T., E-mail: t-matsui@21c.osakafu-u.ac.jp [Research Organization for the 21st Century, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan)

    2015-05-07

    Ferromagnetic layered structure has been made at sub-surface of the antiferromagnetic FeRh bulk samples by high energy He ion beam irradiation. In accordance with the Transport of Ions in Matter simulation, such ion beam can effectively deposit the elastic collision energy in several μm regions in the depth from the surface. Measurement with a superconducting quantum interference device reveals the irradiated samples to be ferromagnetic. Assuming that only the part the energy deposited can be modified to be ferromagnetic, the corresponding irradiation induced magnetization is consistent with the data that we previously reported. On the other hand, the X-ray magnetic circular dichroism (XMCD) spectra for the irradiated samples are totally unchanged as those for the unirradiated samples. Since XMCD signal in total emission yield method is considered to be surface sensitive with a typical probing depth of several nm, the surface magnetic state is maintained to be antiferromagnetic. By utilizing these phenomena, three-dimensional magnetic patterning of FeRh can be realized, which may potentially be used for future magnetic exchange device application such as nano-scale sensors and memories.

  2. Nonlinear dynamics of magnetically coupled beams for multi-modal vibration energy harvesting

    Science.gov (United States)

    Abed, I.; Kacem, N.; Bouhaddi, N.; Bouazizi, M. L.

    2016-04-01

    We investigate the nonlinear dynamics of magnetically coupled beams for multi-modal vibration energy harvesting. A multi-physics model for the proposed device is developed taking into account geometric and magnetic nonlinearities. The coupled nonlinear equations of motion are solved using the Galerkin discretization coupled with the harmonic balance method and the asymptotic numerical method. Several numerical simulations have been performed showing that the expected performances of the proposed vibration energy harvester are significantly promising with up to 130 % in term of bandwidth and up to 60 μWcm-3g-2 in term of normalized harvested power.

  3. Producion of intense focused ion beams in a spherical magnetically insulated diode

    International Nuclear Information System (INIS)

    A magnetically insulated ion diode has been constructed with a spherically focusing geometry. The diode has been operated at voltages of approx.250 and approx.500 kV, with impedances adjusted to 2--3 and 7--10 Ω, respectively. The pulse length was approx.85 ns. Total ion currents were > or =30% of the diode current. In the high-voltage case, a focal current density of 2100 A/cm2 was obtained; this is > or approx. =90 times the anode ion current density. Auxilliary magnetic fields were used to steer the beam, with the beam deflection as calculated for a single proton. The diode design and diagnostic techniques are described, as well as possibilities for improvements suggested by our data

  4. Prospects for Detecting a Neutrino Magnetic Moment with a Tritium Source and Beta-beams

    CERN Document Server

    McLaughlin, G C

    2003-01-01

    We compare the prospects for detecting a neutrino magnetic moment by the measurement of neutrinos from a tritium source, reactors and low-energy beta-beams. In all cases the neutrinos or antineutrinos are detected by scattering of electrons. We find that a large (20 MCurie) tritium source could improve the limit on the neutrino magnetic moment significantly, down to the level of a few $\\times 10^{-12}$ while low-energy beta-beams with sufficiently rapid production of ions could improve the limits to the level of a few $\\times 10^{-11}$. The latter would require ion production at the rate of at least $10^{15}$ s$^{-1}$.

  5. Developments in magnet modeling and beam optics for the ARIS separator at FRIB

    Science.gov (United States)

    Portillo, M.; Hausmann, M.; Chouhan, S.

    2016-06-01

    A description is given on the methods used for field analysis of magnets and the extracted parameters used for accurate beam simulations of the fragment separator. For the strong focusing magnets, Fourier decomposition is used in order to extract induced fields associated with higher order multipoles. For dipoles, a 2D field map model is used instead in order to emulate complex field distributions. The theory of the models and the techniques chosen are described, along with results from Monte Carlo beam simulations up to 5th order. The n = 6 multipole induced by the quadrupole is the most significant component. The effects on separator performance with and without this component in the model are demonstrated.

  6. Velocity evolution of electro-magnetically driven shock wave for beam-dissociated hydrogen interaction experiment

    Science.gov (United States)

    Kondo, Kotaro; Oguri, Yoshiyuki

    2016-03-01

    We present the velocity measurements in electro-magnetic shock tube for beam interaction experiment by three methods; laser refraction, photodiode for self-emission, and high speed framing camera. The laser refraction showed that the average shock velocity was 6.7 km/s when the initial pressure was 1000 Pa and the initial charging voltage was 16 kV. The self-emissions from piston discharge plasma were measured by photodiodes and by high speed framing camera. The measurements showed that the duration between shock and piston was up to 8 microseconds with a 400-mm propagation in the shock tube, which is enough time as dissociation target for beam interaction experiment.The complementary velocity measurement is significant for understanding the electro-magnetically driven shock physics.

  7. Atomic beam magnetic resonance apparatus for systematic measurement of hyperfine structure anomalies (Bohr-Weisskopf effect)

    International Nuclear Information System (INIS)

    An atomic beam magnetic resonance (ABMR) apparatus has been constructed at Orsay, and has been installed at the CERN PS Booster ISOLDE mass separator facility for 'on-line' work with radioactive isotopes in a program to measure hyperfine structure anomalies (the Bohr-Weisskopf effect) over long isotopic chains. The hfs anomalies result from the effect of the spatial distribution of the nuclear magnetization on the atomic hfs interaction. Constructional details of the system are described: Emphasis is placed on the measurement of nuclear g-factors by a triple resonance, laser state selected, ABMR method. A precision better than 10-4 for gI values has been obtained in stable atomic beam tests, leading to hfs anomaly measurements better than 10%. Two types of detection systems are described: Laser fluorescence and surface ionization coupled with mass spectrometry. (orig.)

  8. Measurements of beam current density and proton fraction of a permanent-magnet microwave ion source

    Energy Technology Data Exchange (ETDEWEB)

    Waldmann, Ole; Ludewigt, Bernhard [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2011-11-15

    A permanent-magnet microwave ion source has been built for use in a high-yield, compact neutron generator. The source has been designed to produce up to 100 mA of deuterium and tritium ions. The electron-cyclotron resonance condition is met at a microwave frequency of 2.45 GHz and a magnetic field strength of 87.5 mT. The source operates at a low hydrogen gas pressure of about 0.15 Pa. Hydrogen beams with a current density of 40 mA/cm{sup 2} have been extracted at a microwave power of 450 W. The dependence of the extracted proton beam fraction on wall materials and operating parameters was measured and found to vary from 45% for steel to 95% for boron nitride as a wall liner material.

  9. An assessment of relativistic electron beam for plasma heating in magnetically confined devices

    International Nuclear Information System (INIS)

    The status and progress of various techniques employed for heating the plasma to thermonuclear temperature in magnetically confined devices are presented. The merits and demerits of each technique are critically studied with a view to assess the potential of Relativistic Electron Beam (REB) heating technique, which is a new comer in the field. It has been concluded that REB heating is very much suitable for linear solenoidal reactor devices and is also a potential future candidate for plasma heating for torodial devices. (auth.)

  10. Modelling of integrated effect of volumetric heating and magnetic field on tritium transport in a U-bend flow as applied to HCLL blanket concept

    International Nuclear Information System (INIS)

    Highlights: → 3D transient CFD code based on OpenFOAM toolbox and accounting for MHD and thermal et al. effects. → Hydrodynamic instabilities caused by the jet (generated at the gap narrowing) are found at Reynolds 480. → Hartmann 1740 is able to stabilise the flow. → A heat deposition corresponding to Gr = 5.21 x 109 is sufficient for buoyancy to be predominant at the bend region. Flow becomes unstable. → Tritium permeation ratio cannot be accurately predicted due to major uncertainties in Sievert's coefficient. - Abstract: Under fusion reactor operational conditions, heat deposition might cause a complex buoyant liquid metal flow in the HCLL blanket, what has a direct influence on tritium permeation ratio. In order to characterise the nature of this flow, a simplified HCLL channel, including the U-bend near the reactor first wall, is analysed using a finite volume CFD code, based on OpenFOAM toolbox, following an electric potential based formulation. Code validation results for developed MHD flow and magneto-convective flow are exposed. The influence of the HCLL U-bend on the flow pattern is studied with the validated code, covering the range of possible Reynolds numbers in HCLL-ITER blanket, and considering either electrically insulating or perfectly conducting walls. It can be stated that, despite the very low velocities and the high Hartmann number, flow pattern is complex and unsteady vortices are formed by the action of buoyancy forces together with the influence of the U-bend. Through the analysis, the flow physics is decoupled in order to identify the exact origin of vortex formation. A simplified tritium transport analysis, considering tritium as a passive scalar, has been carried out including a study on boundary conditions influence and a sensitivity analysis of tritium permeation fluxes to diffusivity and solubility parameters. Results show the relevance of Sievert's coefficient uncertainties, which alters the permeation ratio by an order of

  11. LHC magnet quench test with beam loss generated by wire scan

    CERN Document Server

    Sapinski, M; Dahlerup-Petersen, K; Dehning, B; Emery, j; Ferrari, A; Guerrero, A; Holzer, E B; Koujili, M; Lechner, A; Nebot, E; Scheubel, M; Steckert, J; Verweij, A; Wenninger, J

    2011-01-01

    Beam losses with millisecond duration have been observed in the LHC in 2010 and 2011. They are thought to be provoked by dust particles falling into the beam. These losses could compromise the LHC availability if they provoke quenches of superconducting magnets. In order to investigate the quench limits for this loss mechanism, a quench test using a wire scanner has been performed, with the wire movement through the beam mimicking a loss with similar spatial and temporal distribution as in the case of dust particles. This paper will show the conclusions reached for millisecond-duration dust-provoked quench limits. It will include details on the maximum energy deposited in the coil as estimated using FLUKA code, showing a reasonable agreement with quench limit estimated from the heat transfer code QP3. In addition, information on the damage limit for carbon wires in proton beamswill be presented, following electronmicroscope analysis which revealed strong wire sublimation.

  12. Advanced neutral-beam technology

    International Nuclear Information System (INIS)

    Extensive development will be required to achieve the 50- to 75-MW, 175- to 200-keV, 5- to 10-sec pulses of deuterium atoms envisioned for ETF and INTOR. Multi-megawatt injector systems are large (and expansive); they consist of large vacuum tanks with many square meters of cryogenic pumping panels, beam dumps capable of dissipating several megawatts of un-neutralized beam, bending magnets, electrical power systems capable of fast turnoff with low (capacity) stored energy, and, of course, the injector modules (ion sources and accelerators). The technology requirements associated with these components are described

  13. X-ray magnetic circular dichroism photoemission electron microscopy of focused ion beam-induced magnetic patterns on iron–rhodium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tohki, Atsushi; Aikoh, Kazuma; Shinoda, Ryoichi [Department of Materials Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Ohkochi, Takuo [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo 679-5198 (Japan); Kotsugi, Masato [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo 679-5198 (Japan); CREST-JST, Kawaguchi, Saitama 332-0012 (Japan); Nakamura, Tetsuya [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo 679-5198 (Japan); Kinoshita, Toyohiko [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo 679-5198 (Japan); CREST-JST, Kawaguchi, Saitama 332-0012 (Japan); Iwase, Akihiro [Department of Materials Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Matsui, Toshiyuki, E-mail: t-matsui@21c.osakafu-u.ac.jp [Research Organization for the 21st Century, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan)

    2013-05-01

    Iron–rhodium (FeRh) thin films were irradiated with a 30 keV Ga ion beam using a focused ion beam system to produce micrometer scale ferromagnetic square dot arrays. Two-dimensional magnetic square dot arrays with dimensions of 30 × 30, 10 × 10, and 5 × 5 μm were successfully produced on the FeRh surface, which was confirmed by magnetic force microscopy. The results of photoemission electron microscopy combined with X-ray magnetic circular dichroism revealed that the magnetization of the magnetic square dots could be controlled by changing the amount of irradiation. The magnetic domain structure of the magnetic square dots with sides of 5–30 μm was found to be a single domain structure, which was possibly influenced by the interaction between ferromagnetic and antiferromagnetic interfaces.

  14. X-ray magnetic circular dichroism photoemission electron microscopy of focused ion beam-induced magnetic patterns on iron-rhodium surfaces

    Science.gov (United States)

    Tohki, Atsushi; Aikoh, Kazuma; Shinoda, Ryoichi; Ohkochi, Takuo; Kotsugi, Masato; Nakamura, Tetsuya; Kinoshita, Toyohiko; Iwase, Akihiro; Matsui, Toshiyuki

    2013-05-01

    Iron-rhodium (FeRh) thin films were irradiated with a 30 keV Ga ion beam using a focused ion beam system to produce micrometer scale ferromagnetic square dot arrays. Two-dimensional magnetic square dot arrays with dimensions of 30 × 30, 10 × 10, and 5 × 5 μm were successfully produced on the FeRh surface, which was confirmed by magnetic force microscopy. The results of photoemission electron microscopy combined with X-ray magnetic circular dichroism revealed that the magnetization of the magnetic square dots could be controlled by changing the amount of irradiation. The magnetic domain structure of the magnetic square dots with sides of 5-30 μm was found to be a single domain structure, which was possibly influenced by the interaction between ferromagnetic and antiferromagnetic interfaces.

  15. Intense ion beam transport in magnetic quadrupoles: Experiments on electron and gas effects

    International Nuclear Information System (INIS)

    Heavy-ion induction linacs for inertial fusion energy and high-energy density physics have an economic incentive to minimize the clearance between the beam edge and the aperture wall. This increases the risk from electron clouds and gas desorbed from walls. We have measured electron and gas emission from 1 MeV K+ incident on surfaces near grazing incidence on the High-Current Experiment (HCX) at LBNL. Electron emission coefficients reach values >100, whereas gas desorption coefficients are near 104. Mitigation techniques are being studied: A bead-blasted rough surface reduces electron emission by a factor of 10 and gas desorption by a factor of 2. We also discuss the results of beam transport (of 0.03-0.18 A K+) through four pulsed room-temperature magnetic quadrupoles in the HCX at LBNL. Diagnostics are installed on HCX, between and within quadrupole magnets, to measure the beam halo loss, net charge and expelled ions, from which we infer gas density, electron trapping, and the effects of mitigation techniques. A coordinated theory and computational effort has made significant progress towards a self-consistent model of positive-ion beam and electron dynamics. We are beginning to compare experimental and theoretical results

  16. Annular electron beam with virtual cathode in a coaxial diode with magnetic insulation

    Science.gov (United States)

    Grishkov, A. A.; Kurkan, I. K.; Pegel, I. V.

    2014-11-01

    Accumulation of electrons in course of transportation of tubular high-current electron beam in a coaxial diode with magnetic insulation was studied in the situation of counterstream electron motion occurring due to the formation of a virtual cathode. Accumulation of electrons in these flows is accompanied by gradual increase in their relative energy spread and simultaneous decrease in the maximum kinetic energy. The process is described analytically and confirmed in numerical modeling. The theory is an extension of the known theory of coaxial magnetically insulated diode (based on the conservation of axial component of the generalized momentum) taking into account the spread of electron energies. The numerical modeling employed the KARAT electromagnetic PiC-code. Experiments were performed using high-current electron accelerator SINUS-7 (pulsewidth 50 ns) in the range of diode voltages 350—800 kV, magnetic fields 8—24 kOe, electron beam currents 2—12 kA. A gradual increase of potential of the electron beam between the explosive-emission cathode and the virtual cathode was observed, which accompanies accumulation of circulating electrons as predicted in theory.

  17. Annular electron beam with virtual cathode in a coaxial diode with magnetic insulation

    International Nuclear Information System (INIS)

    Accumulation of electrons in course of transportation of tubular high-current electron beam in a coaxial diode with magnetic insulation was studied in the situation of counterstream electron motion occurring due to the formation of a virtual cathode. Accumulation of electrons in these flows is accompanied by gradual increase in their relative energy spread and simultaneous decrease in the maximum kinetic energy. The process is described analytically and confirmed in numerical modeling. The theory is an extension of the known theory of coaxial magnetically insulated diode (based on the conservation of axial component of the generalized momentum) taking into account the spread of electron energies. The numerical modeling employed the KARAT electromagnetic PiC-code. Experiments were performed using high-current electron accelerator SINUS-7 (pulsewidth 50 ns) in the range of diode voltages 350—800 kV, magnetic fields 8—24 kOe, electron beam currents 2—12 kA. A gradual increase of potential of the electron beam between the explosive-emission cathode and the virtual cathode was observed, which accompanies accumulation of circulating electrons as predicted in theory

  18. Pulsed neutron-beam focusing by modulating a permanent-magnet sextupole lens

    Science.gov (United States)

    Yamada, Masako; Iwashita, Yoshihisa; Ichikawa, Masahiro; Fuwa, Yasuhiro; Tongu, Hiromu; Shimizu, Hirohiko M.; Mishima, Kenji; Yamada, Norifumi L.; Hirota, Katsuya; Otake, Yoshie; Seki, Yoshichika; Yamagata, Yutaka; Hino, Masahiro; Kitaguchi, Masaaki; Garbe, Ulf; Kennedy, Shane J.; Tung Lee, Wai; Andersen, Ken H.; Guerard, Bruno; Manzin, Giuliana; Geltenbort, Peter

    2015-04-01

    We have developed a compact permanent-magnet sextupole lens for neutrons that can focus a pulsed beam with a wide wavelength range-the maximum wavelength being more than double the minimum-while sufficiently suppressing the effect of chromatic aberration. The bore diameter is #x00F8;15 mm. Three units of a double-ring sextupole with a length of 66 mm are cascaded, resulting in a total length of 198 mm. The dynamic modulation range of the unit-averaged field gradient is 1.06 × 104-5.86 × 104Tm^{-2}. Permanent magnets and newly developed torque-canceling elements make the device compact, its production costs low, and its operation simpler than that of other magnetic lenses. The efficacy of this lens was verified using very cold neutrons. The diameter of the focused beam spots over the wavelength range of 27-55 Å was the same as that of the source aperture (2 mm diameter) when the magnification of the optical arrangement was unity. The total beam flux over this wavelength range was enhanced by a factor of 43. The focusing distance from the source to the detector was 1.84 m. In addition, in a demonstration of neutron image magnification, the image of a sample mask magnified by a factor of 4.1 was observed when the magnification of the optical arrangement was 5.0.

  19. Generation of a focused proton beam with a self-magnetically BΘ-insulated ion diode

    International Nuclear Information System (INIS)

    A self-magnetically BΘ -insulated ion diode was investigated and optimized at the pulsed power line KALIF (2 MV, 50 ns, 2 Ω) to produce a focused and pulsed high-intensity proton beam for generation of high-power density in matter. This diode is characterized by an azimuthal insulating magnetic field that is generated by the diode current. The beam is neutralized by electrons from the cathode vanes, so that neither a gas filled drift space nor foils are needed. The beam therefore propagates in vacuum and repeated shots are possible without changing parts. The protons had energies up to 1.8 MeV and the proton content in the ion beam was about 50%. The maximum total diode current was about 800 kA and its efficiency was as high as 70%. The beam microdivergence was determined to be 1.1 degree. The radial dependence of the proton current density was measured and is proportional to r-1.74. This result was confirmed by 2D quasistatic particle-in-cell simulations. The focus was optimized by adjusting the anode shape and the gap geometry and by decreasing the beam divergence. The FWHM diameter of the focus at a distance of 300 mm was about 10 mm and the resulting focused power density was 0.13 TW/cm2. The effect of the gap distance on focusing and impedance was investigated and it was found necessary to adjust the gap to better than 0.1 mm over the total 30-cm-diam anode to obtain the best performance. The electron loss and the corresponding erosion at the posts that hold the anode was reduced. The lifetime is now limited by the plastic anode insert to 10--15 pulses. Based on these results a ''small BΘ diode'' is suggested for which a power density increase of a factor of 3 is estimated

  20. Investigation of the chaotic dynamics of an electron beam with a virtual cathode in an external magnetic field

    Science.gov (United States)

    Egorov, E. N.; Hramov, A. E.

    2006-08-01

    The effect of the strength of the focusing magnetic field on chaotic dynamic processes occurring in an electron beam with a virtual cathode, as well as on the processes whereby the structures form in the beam and interact with each other, is studied by means of two-dimensional numerical simulations based on solving a self-consistent set of Vlasov-Maxwell equations. It is shown that, as the focusing magnetic field is decreased, the dynamics of an electron beam with a virtual cathode becomes more complicated due to the formation and interaction of spatiotemporal longitudinal and transverse structures in the interaction region of a vircator. The optimum efficiency of the interaction of an electron beam with the electromagnetic field of the vircator is achieved at a comparatively weak external magnetic field and is determined by the fundamentally two-dimensional nature of the motion of the beam electrons near the virtual cathode.

  1. Design and fabrication of a large rectangular magnetic cusp plasma source for high intensity neutral beam injectors

    International Nuclear Information System (INIS)

    The design and fabrication techniques for a large, rectangular magnetic bucket plasma source are described. This source is compatible with the accelerator structures for the TFTR and DIII neutral-beam systems

  2. Experimental simulation of beam propagation over long path lengths using radio-frequency and magnetic traps

    International Nuclear Information System (INIS)

    An overview is given of the novel beam-dynamics experiments based on compact non-neutral plasma traps at Hiroshima University. We have designed and constructed two different classes of trap systems, one of which uses a radio-frequency electric field (Paul trap) and the other uses an axial magnetic field (Penning trap) for transverse plasma confinement. These systems are called “S-POD” (Simulator for Particle Orbit Dynamics). The S-POD systems can approximately reproduce the collective motion of a charged-particle beam propagating through long alternating-gradient (AG) quadrupole focusing channels using the Paul trap and long continuous focusing channels using the Penning trap. This allows us to study various beam-dynamics issues in compact and inexpensive experiments without relying on large-scale accelerators. So far, the linear Paul traps have been applied for the study of resonance-related issues including coherent-resonance-induced stop bands and their dependence on AG lattice structures, resonance crossing in fixed-field AG accelerators, ultralow-emittance beam stability, etc. The Penning trap with multi-ring electrodes has been employed primarily for the study of beam halo formation driven by initial distribution perturbations. In this paper, we briefly overview the S-POD systems, and then summarize recent experimental results on resonance effects and halo formation

  3. Electron-beam source development for magnetic field alignment on MFTF-B

    International Nuclear Information System (INIS)

    For proper physics operation of the Mirror Fusion Test Facility (MFTF-B) tandem mirror experiment, alignment of the superconducting magnet coils is critical. A narrow, low-energy electron beam is used to trace out the field lines along the axis of the machine. Six crossed-wire detector assemblies are located at various axial positions. The crossed-wire detector is used to locate the electron beam and can trace out flux tubes up to 20 cm in radius. In this paper, the authors describe the design and prototype development of a 1 mA, 10 kV e-beam source used for this diagnostic. Dispenser cathodes are used due to their long lifetime operating at rather high current densities. Experimental results from a prototype gun operating in a 1 kG field are presented. In most cases, the beam diameter was found to match closely the limiting aperture on the e-beam source grid. Also, the effect of secondary-electron emission off the detectors is investigated. Data on the poisoning of dispenser cathodes is also presented

  4. Time-of-flight measurements in atomic beam devices using adiabatic high frequency transitions and sextupole magnets

    International Nuclear Information System (INIS)

    Atomic beam devices are frequently equipped with sextupole magnets to focus the beam or to act as spin filters in combination with RF-transitions for manipulating the hyperfine population within the atomic beam. A useful tool for the analysis of sextupole systems, the application of time-of-flight (TOF) measurements is presented. TOF measurements are enabled without mechanical beam chopper by utilizing adiabatic radio frequency transitions to select atoms within a certain time interval. This method is especially interesting for the use in atomic beam devices that are already equipped with RF-transitions and sextupole magnets and where space limitations or the required quality of the vacuum do not allow the installation of a mechanical chopper. The measurements presented here were performed with the atomic beam polarimeter of the HERMES polarized deuterium target and the results have been used to optimize the sextupole system of the polarimeter

  5. On the use of intense ion beams for generating magnetized target fusion plasma

    International Nuclear Information System (INIS)

    Magnetized Target Fusion (MTF) is a concept for creating a burning D-T plasma in a potentially inexpensive system. In essence, the concept involves ion heating on time scales short compared to ion transport times plus strong inhibition of thermal electron transport with a transverse magnetic field. The magnetic field is not intended to confine the ionic component. MTF is an intrinsically pulsed concept. A straightforward analysis of MTF indicates that D-T burning conditions can be achieved in compact plasma volumes with modest initial temperatures, through the use of pulsed power technology. In terms of size, density, temperature, and time scales, MTF occupies a position in phase space that is intermediate between steady MFE schemes and ICF. In terms of cost, it is one to two orders of magnitude less expensive than these. In this paper, the authors consider a possible method for creating the initial conditions adequate for the MTF concept through the use intense ion beam injection

  6. Fluorine-ion-beam modification of magnetic properties of thin GaMnAs films

    International Nuclear Information System (INIS)

    Magnetic and electrical transport properties of fluorine-ion-beam irradiated GaMnAs films were studied as a function of ion fluence and energy of impinging ions. The different nature of defects created by ions of low- and high-energies is explored in this work by means of transport and magnetization measurements. Our results show that the saturation magnetization of the irradiated samples is suppressed as the ion fluence is increased. Interestingly, however, the same effect is not observed in the case of critical temperature, which remains nearly the same for irradiated and non-irradiated samples measured by superconducting quantum interference device. Magnetotransport measurements appear to provide more reliable results regarding the critical temperature, since they are consistent with the ion-irradiation-induced disorder in the GaMnAs film, quantified here as the increase of the resistivity. We discuss this behavior based on the inhomogeneity of damages caused by the irradiation process

  7. Fluorine-ion-beam modification of magnetic properties of thin GaMnAs films

    Energy Technology Data Exchange (ETDEWEB)

    Mello, S. L. A., E-mail: smello@nd.edu, E-mail: mms@if.ufrj.br, E-mail: furdyna@nd.edu [Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972 RJ (Brazil); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Sant' Anna, M. M., E-mail: smello@nd.edu, E-mail: mms@if.ufrj.br, E-mail: furdyna@nd.edu; Codeço, C. F. S. [Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972 RJ (Brazil); Dong, S. N.; Liu, X.; Furdyna, J. K., E-mail: smello@nd.edu, E-mail: mms@if.ufrj.br, E-mail: furdyna@nd.edu [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Yoo, T. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Physics Department, Korea University, Seoul 136-701 (Korea, Republic of)

    2015-05-07

    Magnetic and electrical transport properties of fluorine-ion-beam irradiated GaMnAs films were studied as a function of ion fluence and energy of impinging ions. The different nature of defects created by ions of low- and high-energies is explored in this work by means of transport and magnetization measurements. Our results show that the saturation magnetization of the irradiated samples is suppressed as the ion fluence is increased. Interestingly, however, the same effect is not observed in the case of critical temperature, which remains nearly the same for irradiated and non-irradiated samples measured by superconducting quantum interference device. Magnetotransport measurements appear to provide more reliable results regarding the critical temperature, since they are consistent with the ion-irradiation-induced disorder in the GaMnAs film, quantified here as the increase of the resistivity. We discuss this behavior based on the inhomogeneity of damages caused by the irradiation process.

  8. Ion beam enhancement in magnetically insulated ion diodes for high-intensity pulsed ion beam generation in non-relativistic mode

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X. P. [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhang, Z. C.; Lei, M. K., E-mail: surfeng@dlut.edu.cn [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Pushkarev, A. I. [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Laboratory of Beam and Plasma Technology, High Technologies Physics Institute, Tomsk Polytechnic University, 30, Lenin Ave, 634050 Tomsk (Russian Federation)

    2016-01-15

    High-intensity pulsed ion beam (HIPIB) with ion current density above Child-Langmuir limit is achieved by extracting ion beam from anode plasma of ion diodes with suppressing electron flow under magnetic field insulation. It was theoretically estimated that with increasing the magnetic field, a maximal value of ion current density may reach nearly 3 times that of Child-Langmuir limit in a non-relativistic mode and close to 6 times in a highly relativistic mode. In this study, the behavior of ion beam enhancement by magnetic insulation is systematically investigated in three types of magnetically insulated ion diodes (MIDs) with passive anode, taking into account the anode plasma generation process on the anode surface. A maximal enhancement factor higher than 6 over the Child-Langmuir limit can be obtained in the non-relativistic mode with accelerating voltage of 200–300 kV. The MIDs differ in two anode plasma formation mechanisms, i.e., surface flashover of a dielectric coating on the anode and explosive emission of electrons from the anode, as well as in two insulation modes of external-magnetic field and self-magnetic field with either non-closed or closed drift of electrons in the anode-cathode (A-K) gap, respectively. Combined with ion current density measurement, energy density characterization is employed to resolve the spatial distribution of energy density before focusing for exploring the ion beam generation process. Consistent results are obtained on three types of MIDs concerning control of neutralizing electron flows for the space charge of ions where the high ion beam enhancement is determined by effective electron neutralization in the A-K gap, while the HIPIB composition of different ion species downstream from the diode may be considerably affected by the ion beam neutralization during propagation.

  9. Ion beam enhancement in magnetically insulated ion diodes for high-intensity pulsed ion beam generation in non-relativistic mode

    International Nuclear Information System (INIS)

    High-intensity pulsed ion beam (HIPIB) with ion current density above Child-Langmuir limit is achieved by extracting ion beam from anode plasma of ion diodes with suppressing electron flow under magnetic field insulation. It was theoretically estimated that with increasing the magnetic field, a maximal value of ion current density may reach nearly 3 times that of Child-Langmuir limit in a non-relativistic mode and close to 6 times in a highly relativistic mode. In this study, the behavior of ion beam enhancement by magnetic insulation is systematically investigated in three types of magnetically insulated ion diodes (MIDs) with passive anode, taking into account the anode plasma generation process on the anode surface. A maximal enhancement factor higher than 6 over the Child-Langmuir limit can be obtained in the non-relativistic mode with accelerating voltage of 200–300 kV. The MIDs differ in two anode plasma formation mechanisms, i.e., surface flashover of a dielectric coating on the anode and explosive emission of electrons from the anode, as well as in two insulation modes of external-magnetic field and self-magnetic field with either non-closed or closed drift of electrons in the anode-cathode (A-K) gap, respectively. Combined with ion current density measurement, energy density characterization is employed to resolve the spatial distribution of energy density before focusing for exploring the ion beam generation process. Consistent results are obtained on three types of MIDs concerning control of neutralizing electron flows for the space charge of ions where the high ion beam enhancement is determined by effective electron neutralization in the A-K gap, while the HIPIB composition of different ion species downstream from the diode may be considerably affected by the ion beam neutralization during propagation

  10. Study on the modification of the beam transport between the cyclotron and the magnetic spectrograph BIG KARL

    International Nuclear Information System (INIS)

    The planned modification of the beam transport between the Julic Cyclotron and the magnetic spectrograph BIG KARL is discussed in view of the aim of an optimal beam preparation. The report contains a detailed consideration of the ion-optical conditions for dispersion fitting and kinematical fitting. In the framework of the matrix formalism the general form of the fitting conditions is presented. (orig.)

  11. SUPERCONDUCTING MAGNET SYSTEM AT THE 50 GEV PROTON BEAM LINE FOR THE J-PARC NEUTRINO EXPERIMENT.

    Energy Technology Data Exchange (ETDEWEB)

    WANDERER,P.; ET AL.

    2003-06-15

    A neutrino oscillation experiment using the J-PARC SO GeV 0.75 MW proton beam is planned as a successor to the K2K project currently being operated at KEK. A superconducting magnet system is required for the arc section of the primary proton beam line to be within the space available at the site. A system with 28 combined function magnets is proposed to simplify the system and optimize the cost. The required fields for the magnets are 2.6 T dipole and 19 T/m quadrupole. The magnets are also required to have a large aperture, 173.4 mm diameter, to accommodate the large beam emittance. The magnets will be protected by cold diodes and cooled by forced flow supercritical helium produced by a 4.5 K, 2 {approx} 2.5 kW refrigerator. This paper reports the system overview and the design status.

  12. Space Charge Correction on Emittance Measurement of Low Energy Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Treado, Colleen J.; /Massachusetts U., Amherst

    2012-09-07

    The goal of any particle accelerator is to optimize the transport of a charged particle beam along a set path by confining the beam to a small region close to the design trajectory and directing it accurately along the beamline. To do so in the simplest fashion, accelerators use a system of magnets that exert approximately linear electromagnetic forces on the charged beam. These electromagnets bend the beam along the desired path, in the case of bending magnets, and constrain the beam to the desired area through alternating focusing and defocusing effects, in the case of quadrupole magnets. We can model the transport of such a beam through transfer matrices representing the actions of the various beamline elements. However, space charge effects, produced from self electric fields within the beam, defocus the beam and must be accounted for in the calculation of beam emittance. We present below the preliminary results of a MATLAB code built to model the transport of a charged particle beam through an accelerator and measure the emittance under the influence of space charge effects. We demonstrate the method of correctly calculating the emittance of a beam under space charge effects using a least square fit to determine the initial properties of the beam given the beam size measured at a specific point after transport.

  13. Characterization of the ELIMED Permanent Magnets Quadrupole system prototype with laser-driven proton beams

    Science.gov (United States)

    Schillaci, F.; Pommarel, L.; Romano, F.; Cuttone, G.; Costa, M.; Giove, D.; Maggiore, M.; Russo, A. D.; Scuderi, V.; Malka, V.; Vauzour, B.; Flacco, A.; Cirrone, G. A. P.

    2016-07-01

    Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines [1]. In the actual ion acceleration scheme, energy and angular spread of the laser-driven beams are the main limiting factors for beam applications and different solutions for dedicated beam-transport lines have been proposed [2,3]. In this context a system of Permanent Magnet Quadrupoles (PMQs) has been realized [2] by INFN-LNS (Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare) researchers, in collaboration with SIGMAPHI company in France, to be used as a collection and pre-selection system for laser driven proton beams. This system is meant to be a prototype to a more performing one [3] to be installed at ELI-Beamlines for the collection of ions. The final system is designed for protons and carbons up to 60 MeV/u. In order to validate the design and the performances of this large bore, compact, high gradient magnetic system prototype an experimental campaign have been carried out, in collaboration with the group of the SAPHIR experimental facility at LOA (Laboratoire d'Optique Appliquée) in Paris using a 200 TW Ti:Sapphire laser system. During this campaign a deep study of the quadrupole system optics has been performed, comparing the results with the simulation codes used to determine the setup of the PMQ system and to track protons with realistic TNSA-like divergence and spectrum. Experimental and simulation results are good agreement, demonstrating the possibility to have a good control on the magnet optics. The procedure used during the experimental campaign and the most relevant results are reported here.

  14. Comparison of PZT and FBG sensing technologies for debonding detection on reinforced concrete beams strengthened with external CFRP strips subjected to bending loads

    Directory of Open Access Journals (Sweden)

    Sevillano, E.

    2016-06-01

    Full Text Available The development of monitoring technologies particularly suitable to be used with novel CFRP strengthening techniques has gained great attention in recent years. However, in spite of the high performance of these advanced composite materials in the strengthening and repairing of structures in service, they are usually associated with brittle and sudden failure mainly caused by debonding phenomena, originated either at the CFRP-plate end or at the intermediate areas in the vicinity of flexural cracks in the RC beam. Thus, it is highly recommended for these structures to be monitored in order to ensure their integrity while in service. Specifically, the feasibility of smart sensing technologies such as Fiber Bragg Grating (FBG sensors and piezo-impedance transducers (PZT has been studied. To the knowledge of the authors, none serious study has been carried out until now concerned to the topic of damage detection due to debonding in rehabilitated structures with CFRP composites.El desarrollo de tecnologías de monitorización aplicables junto con las novedosas técnicas de refuerzo basadas en materiales CFRP ha recibido una atención creciente los últimos años. Sin embargo, a pesar del alto rendimiento de estos avanzados materiales compuestos en la reparación y refuerzo de estructuras en servicio, están habitualmente asociados a fallos frágiles y repentinos causados principalmente por fenómenos de despegue, originados bien en los extremos del refuerzo, bien en áreas intermedias en las proximidades de grietas de flexión existentes en la viga. Por tanto, es altamente recomendable monitorizar estas soluciones estructurales de cara a garantizar su integridad en servicio. Específicamente, se ha estudiado la viabilidad de sensores inteligentes tales como los sensores Fiber Bragg Grating (FBG o los transductores piezoeléctricos (PZT. Hasta donde los autores saben, no se han realizado estudios serios hasta la fecha abordando la detección de da

  15. Design of Neutral Beam-Line of EAST

    Institute of Scientific and Technical Information of China (English)

    胡纯栋; 盛鹏; 许永建; 梁立振; 谢远来; 韦江龙; 谢亚红; 李军; 刘智民; 刘胜; 蒋才超

    2011-01-01

    Neutral beam injector for EAST is designed to deliver deuterium beams with a power of 2 MW to 4 MW at an energy of 50 keV to 80 keV into the plasma with a beam dimension of 12 cm× 48 cm. Considering the beam generation and transmission, a columniform beam-line of Ф 250 cm × 400 cm is designed with a neutralizer, ion dump, calorimeter, bending magnet and cryopanels. The arrangement of the internal elements for the beam-line is reported. A rectangular sleeve coupled to the ion source is employed as the neutralizer. At the downstream of the neutralizer, a dipole magnet separates the residual ions from the beam passage with a reflection radius of 42 cm for the full energy particles. The calorimeter and the ion dump serve as high heat flux components, which will work as thermal inertia targets in the first phase of operation.

  16. SCMAG series of programs for calculating superconducting dipole and quadrupole magnets

    International Nuclear Information System (INIS)

    A general description is given of four computer programs for calculating the characteristics of superconducting magnets used in the bending and focusing of high-energy particle beams. The programs are being used in the design of magnets for the LBL ESCAR (Experimental Superconducting Accelerator Ring) accelerator. (U.S.)

  17. The actual situation of CSA-ring and its beam tracking

    International Nuclear Information System (INIS)

    The CSA (Compact Storage and Acceleration)-ring for FEL was projected in 1989. Its circumference is 15 m. The lattice of the CSA-ring is a double bend double achromatic type. Although the short circumference, it has two long variable straight sections for the undulator. In 1991 August fabrication, the bending magnets were completed and their magnetic field strength was measured. In this paper, we present the design and the characteristics of the ring. Measured distribution of magnetic field and results of beam tracking are also reported. (author)

  18. Design of pulse deflection magnet

    International Nuclear Information System (INIS)

    Deflection magnets are used for the purposes of deflecting the orbit and analyzing the momentum of charged particles, switching charged particles by a pulsed magnetic field and others, in experimental apparatuses or particle accelerators. Here only the fundamental analysis and calculation of the characteristics of the deflection magnets being used in the National Laboratory for High Energy Physics are described. First, the magnetic field intensity B required to bend the path of charged particles, and next, the exciting current required are determined. The effect of a magnetic field when charged particles pass by depends on the effective magnet pole length. Cooling of the magnets is performed by passing cooling water through the hollow conductors used for the magnet coils. The yoke of a pulse magnet is made of silicon steel sheets, the purposes of which are to gain high permeability and reduce eddy current, but the skin effect is also to be considered. Then the inductance of the magnets is determined. Heat generation due to the eddy current in a beam duct in magnet gap must be also calculated. In the practical use of this magnet, beam can be deflected nearly as calculated. A stainless steel beam duct is enough to be used for a few Hz repetition though considerable heat is generated due to eddy current. The beam duct will be replaced with a ceramic duct in future. (Wakatsuki, Y.)

  19. Beam diagnostics with synchrotron radiation

    International Nuclear Information System (INIS)

    Synchrotron radiation is often used to measure the dimensions of an electron beam. The transverse size is obtained from an image of the beam cross section formed by means of the emitted synchrotron radiation. Because of the small natural opening angle the resolution is limited by diffraction. The angular spread of the particles in the beam can be measured by observing the radiation directly. Here, the resolution is limited by the natural opening angle of the emitted light. Measuring both beam cross section and angular spread gives the emittance of the beam. However, in most cases only one of these two parameters is observed and the other deduced from the known particle beam optics at the source of the radiation. Usually one observes radiation emitted in long bending magnets. However, short magnets and undulators are also useful sources for these measurements. For practical reasons the beam diagnostics is carried out using visible or ultraviolet light. This part of the spectrum is usually far below the critical frequency, and corresponding approximations can be applied. Synchrotron radiation is an extremely useful tool for diagnostics in electron (or positron) rings. In some cases it has also served in proton rings using special magnets. (author)

  20. Compliments of confinements: substitution and dimension induced magnetic origin and band-bending mediated photocatalytic enhancements in Bi(1-x)Dy(x)FeO3 particulate and fiber nanostructures.

    Science.gov (United States)

    Sakar, M; Balakumar, S; Saravanan, P; Bharathkumar, S

    2015-06-28

    The manifestation of substitution and dimension induced modifications in the magnetic origin and photocatalytic properties of Dy substituted bismuth ferrite (BDFOx) particulate and fiber nanostructures are reported herein. A gradual transformation from rhombohedral to orthorhombic structure is observed in BFO with the increasing concentration of Dy. Substitution induced size reduction in particulate and fiber nanostructures is evident from the scanning and transmission electron micrographs. Energy band structures of both particulate and fiber nanostructures are considerably influenced by the Dy substitution, which is ascribed to the formation of new energy states underneath the conduction band of host BFO. Field dependent and temperature dependent magnetic studies reveal that the origin of magnetism in pure BFO systems is due to the antiferromagnetic-core/ferromagnetic-shell like structure. On the other hand, it gets completely switched into 'canted' spin structures due to the substitution induced suppression of cycloidal spins in BFO, which is found to be the origin of magnetism in BDFOx particulate and fiber nanostructures. The visible light driven photocatalytic activity of BDFOx nanostructures is found to be enhanced with increasing concentration of Dy. Substitution induced band gap modification, semiconductor band bending phenomenon mediated charge transfer and reduced recombination resistances are attributed to the observed photocatalytic enhancements in these nanostructures. PMID:26029882

  1. Experimental investigation of the propagation of an electron beam in a homogeneous non-magnetized plasma

    International Nuclear Information System (INIS)

    We conduct an experiment on the interaction of a beam with a plasma. The plasma is non-magnetized; its density is uniform, except for a 0.2 m gradient in front of the cathode. The parameters of our beam explore the domain of validity of the quasi-linear and the non-linear theories. In the experiments the solitons and their evolution were investigated. The relative parameters of our beam are similar to those used in other experiments; the density of our plasma, however, is higher than that of the plasmas used in other experiments. The extension of the solitons is practically inobservable: six Debye lengths, i.e. 0.5 mm. The particularity of our method lies in the investigation of the macroscopic effects of the interaction rather than in that of the microscopic effects. These particular conditions give our beam an energy of several keV. The normally employed diagnoses have turned out to be incapable of measuring such distribution functions. We have developed a new rapid electrons analyzer capable of measuring our beam. Nine different experimental conditions have been created. The thermalization distances of our beams are beyond quasi-linear predictions. We have observed that the interaction deeply modifies the plasma. During the shots, the plasma's density presents a gradient extending over the entire length of the vacuum cell. Langmuir waves are excited at both the fundamental and the harmonic frequency of the plasma's beat frequency. Theoretically a distribution function having a plateau can be unstable in a multidimensional system. In an experiment, we have measured the reappearance of a positive slope in a distribution which already had a quasi-linear plateau. 62 refs., 26 figs., 3 tabs

  2. The LACARA Vacuum Laser Accelerator Experiment: Beam Positioning and Alignment in a Strong Magnetic Field

    International Nuclear Information System (INIS)

    LACARA (laser cyclotron auto-resonance accelerator) is a vacuum laser accelerator of electrons that is under construction at the Accelerator Test Facility (ATF), Brookhaven National Laboratory. It is expected that the experiment will be assembled by September 2006; this paper presents progress towards this goal. According to numerical studies, as an electron bunch moves along the LACARA solenoidal magnetic field (∼5.2 T, length ∼1 m), it will be accelerated from 50 to ∼75 MeV by interacting with a 0.8 TW Gaussian-mode circularly polarized optical pulse provided by the ATF CO2 10.6μm laser system. The LACARA laser transport optics must handle 10 J and be capable of forming a Gaussian beam inside the solenoid with a 1.4 mm waist and a Rayleigh range of 60 cm. The electron optics must transport a bunch having input emittance of 0.015 mm-mrad and 100 μm waist through the magnet. Precision alignment between the electron beam and the solenoid magnetic axis is required, and a method to achieve this is described in detail. Emittance- filtering may be necessary to yield an accelerated bunch having a narrow (∼1%) energy-spread

  3. Dispersion suppressors with bending

    Energy Technology Data Exchange (ETDEWEB)

    Garren, A.

    1985-10-01

    Dispersion suppressors of two main types are usually used. In one the cell quadrupole focussing structure is the same as in normal cells but some of the dipoles are replaced by drifts. In the other, the quadrupole strengths and/or spacings are different from those of the normal cells, but the bending is about the same as it is in the cells. In SSC designs to date, dispersion suppressors of the former type have been used, consisting of two cells with bending equivalent to one. In this note a suppressor design with normal bending and altered focussing is presented. The advantage of this scheme is that circumference is reduced. The disadvantages are that additional special quadrupoles must be provided (however, they need not be adjustable), and the maximum beta values within them are about 30% higher than the cell maxima.

  4. Electromagnetic design and development of a combined function horizontal and vertical dipole steerer magnet for medium energy beam transport line

    International Nuclear Information System (INIS)

    Medium Energy Beam Transport (MEBT) line is required to match the optical functions between the RFQ and SRF cavities/DTL cavities.The primary function of the MEBT lines is to keep the emittance growth of the output beam as low as possible in a highly space charge environment at low energies. The transverse focusing of the beam is achieved by strong focusing quadrupoles and the longitudinal dynamics is achieved by the buncher cavities. The Dipole Steerers serve the function of a control element to achieve the desired transverse beam position. To minimize the emittance growth high magnetic field rigidity is required in a highly constrained longitudinal space for these corrector magnets. The design and development of an air-cooled dipole steerer magnet has been done for an integral dipole field of 2.1mT-m in a Good Field Region (GFR) of 23 mm diameter with Integral Field homogeneity better than 0.5%. Electromagnetic field simulations were done using 3D-FEM simulation software OPERA. Error sensitivity studies have been carried out to specify the manufacturing tolerances to estimate and minimize the beam transmission loss due to likely misalignments and rotation of the magnet. A combined function dipole corrector magnet has been designed and fabricated at the Control Instrumentation Division, BARC. This paper discusses measurement results of a combined function dipole steerer for MEBT line for Proton (H+) beam at 2.5 MeV. (author)

  5. Effect of a transverse magnetic field on the generation of electron beams in the gas-filled diode

    Science.gov (United States)

    Baksht, E. H.; Burachenko, A. G.; Erofeev, M. V.; Kostyrya, I. D.; Lomaev, M. I.; Rybka, D. V.; Tarasenko, V. F.

    2008-06-01

    The effect of a transverse magnetic field (0.080 and 0.016 T) on generation of an electron beam in the gas-filled diode is experimentally investigated. It is shown that, at voltage U = 25 kV across the diode and a low helium pressure (45 Torr), the transverse magnetic field influences the beam current amplitude behind a foil and its distribution over the foil cross section. At elevated pressures and under the conditions of ultrashort avalanche electron beam formation in helium, nitrogen, and air, the transverse magnetic field (0.080 and 0.016 T) has a minor effect on the amplitude and duration of the beam behind the foil. It is established that, when the voltage of the pulse generator reaches several hundreds of kilovolts, some runaway electrons (including the electrons from the discharge plasma near the cathode) are incident on the side walls of the diode.

  6. Investigation of the Chaotic Dynamics of an Electron Beam with a Virtual Cathode in an External Magnetic Field

    CERN Document Server

    Egorov, E N

    2006-01-01

    The effect of the strength of the focusing magnetic field on chaotic dynamic processes occurring inan electron beam with a virtual cathode, as well as on the processes whereby the structures form in the beamand interact with each other, is studied by means of two-dimensional numerical simulations based on solving a self-consistent set of Vlasov-Maxwell equations. It is shown that, as the focusing magnetic field is decreased,the dynamics of an electron beam with a virtual cathode becomes more complicated due to the formation andinteraction of spatio-temporal longitudinal and transverse structures in the interaction region of a vircator. The optimum efficiency of the interaction of an electron beam with the electromagnetic field of the vircator isachieved at a comparatively weak external magnetic field and is determined by the fundamentally two-dimensional nature of the motion of the beam electrons near the virtual cathode.

  7. Magnetic study of extraction elements of compact cyclotron beam with AGOR superconducting coils

    International Nuclear Information System (INIS)

    The extraction system of the superconducting cyclotrons is normally making a large use of electric extractors followed by magnetostatic elements. The electric field limit initially hoped for (14 MV/m) has been shown to be too optimistic. A more realistic value is around 10 MV/m in the concerned geometries. The first element of the AGOR extraction system is an electrostatic channel where the maximum electric field is limited to 10.5 MV/m. The smaller separation between the internal beam and the extracted beam at the entrance of the first magnetic element is compensated by the replacement of the usual magnetostatic channels with high power electromagnetic channels placed in the reduced space close to the internal beam and where the horizontal position can be adjusted according to the kind of ion accelerated and its energy. The fringing field very close to the channels is controlled with the help of correction coils reducing the perturbations of the internal beam trajectories to an acceptable level

  8. Electron-beam source development for magnetic field alignment of MFTF-B

    International Nuclear Information System (INIS)

    For proper physics operation of the Mirror Fusion Test Facility (MFTF-B) tandem mirror experiment, alignment of the superconducting magnet coils is critical. A narrow (1 mm diameter), low-energy electron beam is used to trace out the field lines along the axis of the machine. Six crossed-wire detector assemblies are located at various axial positions. The crossed-wire detector is used to locate the electron beam and can trace out flux tubes up to 20 cm in radius. In this paper, we describe the design and prototype development of a 1 mA, 10 kV e-beam source used for this diagnostic. Dispenser cathodes are used due to their long lifetime operating at rather high current densities. The current range of 0.1 to 1 mA was chosen to provide good signal-to-noise, while the energy range of 1 to 10 kV is necessary to closely follow the field lines and to avoid space-charge spreading of the beam. Experimental results from a prototype gun operating in a 1 kG field are presented

  9. Preliminary considerations concerning neutral plasma beam propagation across a magnetic field

    International Nuclear Information System (INIS)

    A plan to address physical questions of interest for exoatmospheric military applications of intense neutralized plasma beams is described. After a brief review of earlier work relevant to this matter and a detailed explanation of why such work cannot answer questions of present interest, a plan employing interactive application of several numerical and analytic techniques to treat relevant phenomena occurring on the various rather disparate time and length scales involved is suggested. The first part of the study would determine the macroscopic features of beam propagation through calculations effected with a magnetohydrodynamical numerical code. Classical transport coefficients would be employed in this initial phase. Using information thus gained concerning gross charge and current distributions, particle-in-cell simulations would be initialized to study those microscopic, phase-space-dependent phenomena which can alter the phenomonological transport coefficients appearing in the fluid description. Insight thereby gained concerning anomaous, collectively induced transport effects would then be applied to yield a refined, accurate description of the macroscopic aspects of neutral plasma beam propagation. Personnel and computational resources available at the Los Alamos Scientific Laboratory are described. Results of a very preliminary particle-in-cell simulation of a neutral plasma beam propagating across a magnetic field are presented

  10. Field stability by the electron beam in a warm magnetized plasma-filled waveguide

    International Nuclear Information System (INIS)

    We study the effect of the electron beam on the field stability and minimizing the energy losses in waveguide filled with plasma. Analytical calculations are performed to find the plasma dielectric tensor. By applying the boundary conditions at the plasma-conductor interface, we derive the dispersion equations, which describe the propagated E- and H- waves and their damping rate. The necessary condition for the field stability in the waveguide and the amplification coefficient for the E- wave are obtained. Realistic plasma conditions (i.e. its warmness and inhomogeneity under the effect of an external static magnetic field) are taken into consideration. The electron beam is found to play a crucial role in controlling the field attenuation in waveguide. (author)

  11. Guiding of Relativistic Electron Beams in Solid Targets by Resistively Controlled Magnetic Fields

    Science.gov (United States)

    Kar, S.; Robinson, A. P. L.; Carroll, D. C.; Lundh, O.; Markey, K.; McKenna, P.; Norreys, P.; Zepf, M.

    2009-02-01

    Guided transport of a relativistic electron beam in solid is achieved experimentally by exploiting the strong magnetic fields created at the interface of two metals of different electrical resistivities. This is of substantial relevance to the Fast Ignitor approach to fusion energy production [M. Tabak , Phys. PlasmasPHPAEN1070-664X 12, 057305 (2005)10.1063/1.1871246], since it allows the electron deposition to be spatially tailored—thus adding substantial design flexibility and preventing inefficiencies due to electron beam spreading. In the experiment, optical transition radiation and thermal emission from the target rear surface provide a clear signature of the electron confinement within a high resistivity tin layer sandwiched transversely between two low resistivity aluminum slabs. The experimental data are found to agree well with numerical simulations.

  12. Structural and magnetic properties of SmCo-based magnetic films grown by electron-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, P., E-mail: psdrdo@gmail.com [Defence Metallurgical Research Laboratory, Hyderabad 500058 (India); Vinod, V.T.P.; Černík, Miroslav [Institute for Nanomaterials, Advanced Technologies and Innovation, Department of Natural Sciences, Technical University of Liberec, Studentská 1402/2, Liberec 1, 461 17 (Czech Republic); Vishnuraj, R.; Arout Chelvane, J.; Kamat, S.V. [Defence Metallurgical Research Laboratory, Hyderabad 500058 (India); Hsu, Jen-Hwa, E-mail: jhhsu@phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

    2015-07-01

    Sub-micron thick Sm–Co films (200 and 300 nm) with selective phase composition are grown on Si (100) substrates by electron-beam evaporation using Sm-lean alloy targets such as Sm{sub 4}Co{sub 96} and Sm{sub 8}Co{sub 92}. The structural and magnetic properties of Sm–Co films are characterized by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and super-conducting quantum interference device (SQUID) magnetometer. The Sm–Co films obtained with the Sm{sub 4}Co{sub 96} target exhibit Sm{sub 2}Co{sub 17} as a prominent phase; while the films produced with the Sm{sub 8}Co{sub 92} target show Sm{sub 2}Co{sub 7} as a major phase. Both the Sm–Co films reveal granular morphology; however, the estimated grain size values are slightly lower in the case of Sm{sub 2}Co{sub 7} films, irrespective of their thicknesses. Coercivity (H{sub c}) values of 1.48 and 0.9 kOe are achieved for the as-grown 200-nm thick Sm{sub 2}Co{sub 17} and Sm{sub 2}Co{sub 7}-films. Temperature-dependent magnetization studies confirm that the demagnetization behaviors of these films are consistent with respect to the identified phase composition. Upon rapid thermal annealing, maximum H{sub c} value of 8.4 kOe is achieved for the 200 nm thick Sm{sub 2}Co{sub 17}-films. As far as e-beam evaporated Sm–Co films are concerned, this H{sub c} value is one of the best values reported so far. - Highlights: • Electron-beam evaporation was exploited to grow sub-μm thick Sm–Co films. • Sm{sub 2}Co{sub 7} and Sm{sub 2}Co{sub 17} magnetic phases were crystallized using Sm-lean alloy targets. • Both 200 and 300-nm thick Sm–Co films revealed distinct granular morphology. • Sm–Co films of lower thickness exhibited high H{sub c} and low M{sub s} and vice-versa. • Coercivity value of 8.4 kOe achieved for the 200-nm thick Sm{sub 2}Co{sub 17}-films after RTA.

  13. Research and development of an electron beam focusing system for a high-brightness X-ray generator

    International Nuclear Information System (INIS)

    In order to minimize the size of the X-ray source for a U-shaped rotating anticathode X-ray generator, the electron beam is focused over a short distance by a combined-function bending magnet. Simulation predicts that the beam brightness will reach almost 500 kW mm−2 for a 120 keV/75 mA beam. A new type of rotating anticathode X-ray generator, where an electron beam of up to 60 keV irradiates the inner surface of a U-shaped Cu anticathode, has achieved a beam brilliance of 130 kW mm−2 (at 2.3 kW). A higher-flux electron beam is expected from simulation by optimizing the geometry of a combined-function-type magnet instead of the fringing field of the bending magnet. In order to minimize the size of the X-ray source the electron beam has been focused over a short distance by a new combined-function bending magnet, whose geometrical shape was determined by simulation using the Opera-3D, General Particle Tracer and CST-STUDIO codes. The result of the simulation clearly shows that the role of combined functions in both the bending and the steering magnets is important for focusing the beam to a small size. FWHM sizes of the beam are predicted by simulation to be 0.45 mm (horizontal) and 0.05 mm (vertical) for a 120 keV/75 mA beam, of which the effective brilliance is about 500 kW mm−2 on the supposition of a two-dimensional Gaussian distribution. High-power tests have begun using a high-voltage 120 kV/75 mA power supply for the X-ray generator instead of 60 kV/100 mA. The beam focus size on the target will be verified in the experiments

  14. Beam transfer line for food irradiation microtron at CAT

    International Nuclear Information System (INIS)

    A 10 MeV microtron is being developed at CAT for irradiation of food products. A beam transfer line comprising a 90 deg bending magnet, a quadrupole doublet and a rectangular scanning magnet has been designed to irradiate food products from the upper side. The bending magnet has an edge angle of 22.5 deg. The length of the beam transfer line has been minimized to keep the whole unit as compact as possible. The beam optics has been optimized keeping in view the requirement of a small beam pipe aperture (25mm radius) and a large range of circular as well as elliptical beam sizes on the food product. The speed of the conveyor belt has been assumed to be very small. The results of the beam optics chosen and the variation of the linear charge density on a food product during the scanning are presented in this paper. The effects of path length variation within the scanning magnet and beam size variation during a scanning are also discussed

  15. Research on numerical simulation on the whole cracking processes of three-point bending notch concrete beams%混凝土三点弯曲梁裂缝断裂全过程数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    管俊峰; 卿龙邦; 赵顺波

    2013-01-01

    Based on Paris' displacement formula and by considering the role of cohesive stress in the fracture of concrete,a theoretical expression for crack opening displacement of three-point bending notched beams is derived. Then, with the initial fracture toughness taken as the criterion of crack initiation, the derived expression is applied in simulating the whole cracking processes of concrete, including the beginning and development of cracking as well as the subsequent failure of concrete. To test the validity and performance of the model proposed in this paper,its calculating result is compared with experimental data and that of the finite element model and a high agreement exits among them,which indicates that the proposed method is not only simple in form and application but also with high precision.%考虑裂缝黏聚力的作用,基于Paris位移公式推导出混凝土三点弯曲梁裂缝扩展过程中断裂过程区上的裂缝张开位移的解析表达式.采用起裂韧度作为裂缝起裂及扩展的判断标准,提出了荷载作用下混凝土裂缝起裂、扩展及失稳破坏全过程的数值模拟方法,并分别与国内外断裂试验实测值及有限元计算值进行了比较.结果表明,本文提出的数值模拟方法形式简单且精度较好.

  16. Synchrotron radiation based beam diagnostics at the Fermilab Tevatron

    CERN Document Server

    Thurman-Keup, R; Hahn, A; Hurh, P; Lorman, E; Lundberg, C; Meyer, T; Miller, D; Pordes, S; Valishev, A

    2011-01-01

    Synchrotron radiation has been used for many years as a beam diagnostic at electron accelerators. It is not normally associated with proton accelerators as the intensity of the radiation is too weak to make detection practical. However, if one utilizes the radiation originating near the edge of a bending magnet, or from a short magnet, the rapidly changing magnetic field serves to enhance the wavelengths shorter than the cutoff wavelength, which for more recent high energy proton accelerators such as Fermilab's Tevatron, tends to be visible light. This paper discusses the implementation at the Tevatron of two devices. A transverse beam profile monitor images the synchrotron radiation coming from the proton and antiproton beams separately and provides profile data for each bunch. A second monitor measures the low-level intensity of beam in the abort gaps which poses a danger to both the accelerator's superconducting magnets and the silicon detectors of the high energy physics experiments. Comparisons of measur...

  17. Rapid cycling medical synchrotron and beam delivery system

    Science.gov (United States)

    Peggs, Stephen G.; Brennan, J. Michael; Tuozzolo, Joseph E.; Zaltsman, Alexander

    2008-10-07

    A medical synchrotron which cycles rapidly in order to accelerate particles for delivery in a beam therapy system. The synchrotron generally includes a radiofrequency (RF) cavity for accelerating the particles as a beam and a plurality of combined function magnets arranged in a ring. Each of the combined function magnets performs two functions. The first function of the combined function magnet is to bend the particle beam along an orbital path around the ring. The second function of the combined function magnet is to focus or defocus the particle beam as it travels around the path. The radiofrequency (RF) cavity is a ferrite loaded cavity adapted for high speed frequency swings for rapid cycling acceleration of the particles.

  18. Workshop on CEBAF [Continuous Electron Beam Accelerator Facility] spectrometer magnet design and technology: Proceedings

    International Nuclear Information System (INIS)

    The planned experimental program at CEBAF includes high-resolution, large acceptance spectrometers and a large toroidal magnetic, detector. In order to take full advantage of the high quality beam characteristics, the performances required will make these devices quite unique instruments compared to existing facilities in the same energy range. Preliminary designs have shown that such performances can be reached, but key questions concerning design concepts and most appropriate and cost-effective technologies had to be answered before going further with the designs. It was the purpose of the Workshop on CEBAF Spectrometer Magnet Design and Technology, organized by the CEBAF Research and Engineering Divisions, to provide the most complete information about the state-of-the-art tools and techniques in magnet design and construction and to discuss the ones most appropriate to the CEBAF spectrometers. In addition, it is expected that this Workshop will be the staring point for further interactions and collaborations between international magnet experts and the CEBAF staff, during the whole process of designing and building the spectrometers

  19. Calculation of the transverse kicks generated by the bends of a hollow electron lens

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio

    2014-03-25

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam in high-energy accelerators. They were used in the Fermilab Tevatron collider for abort-gap clearing, beam-beam compensation, and halo scraping. A beam-beam compensation scheme based upon electron lenses is currently being implemented in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. This work is in support of a conceptual design of hollow electron beam scraper for the Large Hadron Collider. It also applies to the implementation of nonlinear integrable optics with electron lenses in the Integrable Optics Test Accelerator at Fermilab. We consider the axial asymmetries of the electron beam caused by the bends that are used to inject electrons into the interaction region and to extract them. A distribution of electron macroparticles is deposited on a discrete grid enclosed in a conducting pipe. The electrostatic potential and electric fields are calculated using numerical Poisson solvers. The kicks experienced by the circulating beam are estimated by integrating the electric fields over straight trajectories. These kicks are also provided in the form of interpolated analytical symplectic maps for numerical tracking simulations, which are needed to estimate the effects of the electron lens imperfections on proton lifetimes, emittance growth, and dynamic aperture. We outline a general procedure to calculate the magnitude of the transverse proton kicks, which can then be generalized, if needed, to include further refinements such as the space-charge evolution of the electron beam, magnetic fields generated by the electron current, and longitudinal proton dynamics.

  20. High energy micro electron beam generation using chirped laser pulse in the presence of an axial magnetic field

    International Nuclear Information System (INIS)

    In this paper, the generation of high-quality and high-energy micro electron beam in vacuum by a chirped Gaussian laser pulse in the presence of an axial magnetic field is numerically investigated. The features of energy and angular spectra, emittances, and position distribution of electron beam are compared in two cases, i.e., in the presence and absence of an external magnetic field. The electron beam is accelerated with higher energy and qualified in spatial distribution in the presence of the magnetic field. The presence of an axial magnetic field improves electron beam spatial quality as well as its gained energy through keeping the electron motion parallel to the direction of propagation for longer distances. It has been found that a 64 μm electron bunch with about MeV initial energy becomes a 20 μm electron beam with high energy of the order of GeV, after interacting with a laser pulse in the presence of an external magnetic field

  1. High energy micro electron beam generation using chirped laser pulse in the presence of an axial magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Akou, H., E-mail: h.akou@nit.ac.ir; Hamedi, M. [Department of Physics, Faculty of Basic Science, Babol University of Technology, Babol 47148-71167 (Iran, Islamic Republic of)

    2015-10-15

    In this paper, the generation of high-quality and high-energy micro electron beam in vacuum by a chirped Gaussian laser pulse in the presence of an axial magnetic field is numerically investigated. The features of energy and angular spectra, emittances, and position distribution of electron beam are compared in two cases, i.e., in the presence and absence of an external magnetic field. The electron beam is accelerated with higher energy and qualified in spatial distribution in the presence of the magnetic field. The presence of an axial magnetic field improves electron beam spatial quality as well as its gained energy through keeping the electron motion parallel to the direction of propagation for longer distances. It has been found that a 64 μm electron bunch with about MeV initial energy becomes a 20 μm electron beam with high energy of the order of GeV, after interacting with a laser pulse in the presence of an external magnetic field.

  2. Development of an all-permanent-magnet microwave ion source equipped with multicusp magnetic fields for high current proton beam production.

    Science.gov (United States)

    Tanaka, M; Hara, S; Seki, T; Iga, T

    2008-02-01

    An all-permanent-magnet (APM) microwave hydrogen ion source was developed to reduce the size and to simplify structure of a conventional solenoid coil microwave ion source developed for reliability improvement of high current proton linac application systems. The difficulty in developing the APM source was sensitive dependence of the source performance on axial magnetic field in the microwave discharge chamber. It was difficult to produce high current proton beam stably without precise tuning of the magnetic field using solenoid coils. We lowered the sensitivity using multicusp magnetic fields for plasma confinement at the discharge chamber sidewall of the source. This enabled stable high current proton beam production with the APM microwave ion source with no tuning coil. The water cooling and the power supply for the coils are not necessary for the APM source, which leads to better reliability and system simplification. The outer diameter of the APM source was around 300 mm, which was 20% lower than the coil source. The APM source produced a maximum hydrogen ion beam current of 65 mA (high current density of 330 mA/cm(2), proton ratio of 87%, and beam energy of 30 keV) with a 5 mm diameter extraction aperture, pulse width of 400 micros, and 20 Hz repetition rate at 1.3 kW microwave power. This performance is almost the same as the best performances of the conventional coil sources. The extracted ion beams were focused with electrostatic five-grid lens to match beam to acceptance of radio-frequency quadrupole linacs. The maximum focused beam current through the orifice (5 mm radius) and the lens was 36 mA and the 90% focused beam half-width was 1-2 mm. PMID:18315183

  3. MEMS device for bending test: measurements of fatigue and creep of electroplated nickel

    DEFF Research Database (Denmark)

    Larsen, Kristian Pontoppidan; Rasmussen, Anette Alsted; Ravnkilde, Jan Tue;

    2003-01-01

    In situ bending test devices with integrated electrostatic actuator were fabricated in electroplated nanocrystalline nickel. The device features approximately pure in-plane bending of the test beam. The excitation of the test beam has fixed displacement amplitude as the actuation electrodes are o...

  4. Guiding of relativistic electron beams in dense matter by longitudinally imposed strong magnetic fields

    CERN Document Server

    Bailly-Grandvaux, M; Bellei, C; Forestier-Colleoni, P; Fujioka, S; Giuffrida, L; Honrubia, J J; Batani, D; Bouillaud, R; Chevrot, M; Cross, J E; Crowston, R; Dorard, S; Dubois, J -L; Ehret, M; Gregori, G; Hulin, S; Kojima, S; Loyez, E; Marques, J -R; Morace, A; Nicolai, Ph; Roth, M; Sakata, S; Schaumann, G; Serres, F; Servel, J; Tikhonchuk, V T; Woolsey, N; Zhang, Z

    2016-01-01

    High-energy-density flows through dense matter are needed for effective progress in the production of laser-driven intense sources of energetic particles and radiation, in driving matter to extreme temperatures creating state regimes relevant for planetary or stellar science as yet inaccessible at the laboratory scale, or in achieving high-gain laser-driven thermonuclear fusion. When interacting at the surface of dense (opaque) targets, intense lasers accelerate relativistic electron beams which transport a significant fraction of the laser energy into the target depth. However, the overall laser-to-target coupling efficiency is impaired by the large divergence of the electron beam, intrinsic to the laser-plasma interaction. By imposing a longitudinal 600T laser-driven magnetic-field, our experimental results show guided >10MA-current of MeV-electrons in solid matter. Due to the applied magnetic field, the transported energy-density and the peak background electron temperature at the 60micron-thick targets re...

  5. A compact design for a magnetic synchrotron to store beams of hydrogen atoms

    CERN Document Server

    van der Poel, Aernout P P; Softley, Timothy P; Bethlem, Hendrick L

    2015-01-01

    We present a design for an atomic synchrotron consisting of 40 hybrid magnetic hexapole lenses arranged in a circle. We show that for realistic parameters, hydrogen atoms with a velocity up to 600 m/s can be stored in a 1-meter diameter ring, which implies that the atoms can be injected in the ring directly from a pulsed supersonic beam source. This ring can be used to study collisions between stored hydrogen atoms and molecular beams of many different atoms and molecules. The advantage of using a synchrotron is two-fold: (i) the collision partners move in the same direction as the stored atoms, resulting in a small relative velocity and thus a low collision energy, and (ii) by storing atoms for many round-trips, the sensitivity to collisions is enhanced by a factor of 100-1000. In the proposed ring, the cross-sections for collisions between hydrogen, the most abundant atom in the universe, with any atom or molecule that can be put in a beam, including He, H$_2$, CO, ammonia and OH can be measured at energies...

  6. EPICS based control system of pulse bend correction coil

    International Nuclear Information System (INIS)

    The pulse-bend magnet in J-PARC 3-50BT has the residual magnetic field, slightly after it has sent protons to MR. Due to this effect, we can not supply protons to the MLF, during three 25Hz-cycles. A correction coil and its custom made power-supply were introduced in order to cancel out the residual magnetic field. We have constructed an EPICS-based control systems for this correction coil power supply. The control system have four components: (1) a PLC controller with a Linux CPU and I/O modules, (2) a commercial function generator, (3) a custom made power-supply to drive coil current, and (4) a timing module to provide proper trigger signals. A pattern waveform, delivered from a function generator, is used to drives the customized power supply. We have examined basic functionalities of the control system during beam studies in May and in June 2014, and confirmed its availabilities, namely status monitoring and operation controls. However, we found some problems in interlock signals of the power-supply. We will improve the system toward the next operation from this autumn. (author)

  7. Electric and magnetic field measurements inside a high-velocity neutral beam undergoing ionization

    International Nuclear Information System (INIS)

    Vector electric field measurements have been made inside two ionizing, high-velocity streams of barium atoms in the Earth's ionosphere. A variety of electrical phenomena were observed across the frequency spectrum and are presented in this paper, which emphasizes the experimental results. A most startling result is that a very large quasi-dc electric field was detected antiparallel to the beam velocity. This by itself is not unreasonable since newly ionized barium ions with their large gyroradii are expected to create such a field. But since the beam had roughly a 45 degree angle with the magnetic field, Bo, the authors find a very large (approx-gt 500 mV/m) component of E parallel to Bo. The fluctuating electric fields were also quite large, in fact, of the same order of magnitude as the quasi-dc pulse. The wave energy was found to maximize at frequencies below the barium lower hybrid frequency and included strong signatures of the oxygen cyclotron frequency. Measurements made on a subpayload separated across Bo by several hundred meters and along Bo by several kilometers do not show the large pulse, although a variety of wave emissions were seen. In addition, very large amplitude magnetic field fluctuations were detected in both bursts. Although they have no clear explanation, they appear to be real phenomenon and worthy of future study. Finally, they note that even though the critical ionization velocity effect did not go into a discharge mode in this experiment, remarkable electromagnetic effects were seen in the neutral beam-plasma interaction

  8. The saturation of the electron beam filamentation instability by the self-generated magnetic field and magnetic pressure gradient-driven electric field

    CERN Document Server

    Dieckmann, M E; Kourakis, I; Borghesi, M

    2008-01-01

    Two counter-propagating cool and equally dense electron beams are modelled with particle-in-cell (PIC) simulations. The electron beam filamentation instability is examined in one spatial dimension. The box length resolves one pair of current filaments. A small, a medium-sized and a large filament are considered and compared. The magnetic field amplitude at the saturation time of the filamentation instability is proportional to the filament size. It is demonstrated, that the force on the electrons imposed by the electrostatic field, which develops during the nonlinear stage of the instability, oscillates around a mean value that equals the magnetic pressure gradient force. The forces acting on the electrons due to the electrostatic and the magnetic field have a similar strength. The electrostatic field reduces the confining force close to the stable equilibrium of each filament and increases it farther away. The confining potential is not sinusoidal, as assumed by the magnetic trapping model, and it permits an...

  9. Preliminary Measurement of Beam Power Transmission in KSTAR Neutral Beam Test-Stand

    International Nuclear Information System (INIS)

    A neutral beam test-stand (NBTS) was constructed to develop 300-sec deuterium beam extraction of 120 kV/65 A as an auxiliary heating system of KSTAR. The ion source is composed of a plasma generator and a tetrode accelerator. The beamline components include an optical multi-channel analyzer (OMA) duct, a neutralizer, a bending magnet (BM), an ion dump, a calorimeter, and a cryo-sorption pump system. Beam deposition along the NBTS has been measured by water flow calorimetry (WFC) and 96 % of the extracted beam power (Vacc·Iacc) was counted for a beam of 97 kV/22.2 A. Maximum power transmission efficiency, which is the ratio of transmitted power on the calorimeter to the extracted beam power, was 0.77 with an optimum perveance of 1.1 microperv

  10. Laser steering of particle beams: refraction and reflection of particle beams

    International Nuclear Information System (INIS)

    The co-propagation of an intense particle beam with an ionizing laser beam in a working gas/plasma is considered. When the axes of the laser and particle beam are not aligned, then asymmetric plasma lensing results in a net dipole field acting on the particle beam. The particle beam can be steered or bent (as well as focused) by steering the laser. An analogy is made between the bending of the particle beam by collective effects at a plasma boundary and the refraction or reflection of light at an interface. This mechanism of particle steering may be of interest in applications for which permanent magnets are inconvenient or a fast turn on is required. 3-D particle-in-cell simulations and relevance to a recent experiment are discussed

  11. Low-field permanent magnet quadrupoles in a new relativistic-klystron two-beam accelerator design

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Sessler, A. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Permanent magnets play a central role in the new relativistic klystron two-beam-accelerator design. The two key goals of this new design, low cost and the suppression of beam break-up instability are both intimately tied to the permanent magnet quadrupole focusing system. A recently completed systems study by a joint LBL-LLNL team concludes that a power source for a 1 TeV center-of-mass Next Linear Collider based on the new TBA design can be as low as $1 billion, and the efficiency (wall plug to rf) is estimated to be 36%. End-to-end simulations of longitudinal and transverse beam dynamics show that the drive beam is stable over the entire TBA unit.

  12. Beam dynamics studies during commissioning of two undulators in Indus-2

    International Nuclear Information System (INIS)

    Indus-2, a synchrotron light source facility at RRCAT, Indore is in continuous operation at 2.5 GeV, generating the synchrotron radiation from its bending magnets. For enhancing the intensity of synchrotron radiation, two planar undulators have been installed and successfully commissioned with the Indus-2 electron beam. Various beam dynamical challenges such as beam accumulation, beam energy ramping and storage at 2.5 GeV have been addressed to ensure the smooth commissioning of these devices. Moreover, due to interaction of the stored beam with magnetic field of undulators, various parameters of the electron beam get changed. In this paper, the beam dynamics studies to ensure the smooth commissioning of these devices and its measured effect on beam parameters have been presented. (author)

  13. A computer simulation code of heat input due to incidence of fast ion beam

    International Nuclear Information System (INIS)

    A computer code has been developed to evaluate heat flux due to bombardment of ion beam to the beam limiters and beam dump of the neutral beam injector. In this code, energetic ions extracted from the ion source are represented by finite number of test particles, and their trajectories are calculated in the presense of magnetic field. They are bent and reflected as they pass through the bending magnet region. Finally they bombard the wall of the beam limiters and beam dump, where their energies are deposited. The heat flux can be derived from the number of bombarding test particles in a unit area. The code has been applied to the design of beam line hardwares of the JT-60 neutral beam injectors. (author)

  14. Self focusing of laser beams and its effect in the generation of magnetic field in laser-produced plasma

    International Nuclear Information System (INIS)

    The present work deals with the generation of magnetic field in a plasma due to self focusing effects of laser beam. Spontaneously generated magnetic fields of the order of several kilogauss have been investigated and the cause for the generation of B-field has been attributed to the time dependent ponderomotive force of a self focused inhomogeneous gaussian shaped laser beam. The magnitude of the magnetic field is found to increase with self focusing effect of the laser beam. It can be shown that for high-frequency laser (viz. Nd-glass laser having the wavelength (λ) = 1.06 μm and amplitude of E-field (E00) = 3.9 x 1011 V/m), the magnitude of B-field is found to be in better agreement with the experiment. B-field varies inversely with temperature which has not been taken care in earlier reports. (author)

  15. Copper ion implanted aluminum nitride dilute magnetic semiconductors (DMS) prepared by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Highlights: • AlN:Cu dilute magnetic semiconductors were successfully prepared by molecular beam epitaxy followed by Cu+ implantation. • Room temperature ferromagnetism was observed after annealing the samples at appropriate temperature. • XRD and Raman spectrometry excluded the possibility of formation of any secondary phases. • By doping intrinsically nonmagnetic dopants (Cu), it has been proved experimentally that their precipitates do not contribute to ferromagnetism. • The reason for ferromagnetism in Cu-doped AlN as observed was explained on the basis of p–d hybridization mechanism (Wu et al.). - Abstract: Diluted magnetic semiconductor (DMS) AlN:Cu films were fabricated by implanting Cu+ ions into AlN thin films at various ion fluxes. AlN films were deposited on c-plane sapphire by molecular beam epitaxy followed by Cu+ ion implantation. The structural and magnetic characterization of the samples was performed through Rutherford backscattering and channeling spectrometry (RBS/C), X-ray diffraction (XRD), Raman spectroscopy, vibrating sample magnetometer (VSM) and SQUID. Incorporation of copper into the AlN lattice was confirmed by RBS, while XRD revealed that no new phase was formed as a result of ion implantation. RBS also indicated formation of defects as a result of implantation process and the depth and degree of damage increased with an increase in ion fluence. Raman spectra showed only E2 (high) and A1 (LO) modes of wurtzite AlN crystal structure and confirmed that no secondary phases were formed. It was found that both Raman modes shift with Cu+ fluences, indicating that Cu ion may go to interstitial or substitutional sites resulting in distortion or damage of lattice. Although as implanted samples showed no magnetization, annealing of the samples resulted in appearance of room temperature ferromagnetism. The saturation magnetization increased with both the annealing temperature as well as with ion fluence. FC/ZFC measurements indicated

  16. Development of an efficient scanning and purging magnet system for IMRT with narrow high energy photon beams

    Science.gov (United States)

    Andreassen, Björn; Svensson, Roger; Holmberg, Rickard; Danared, Håkan; Brahme, Anders

    2009-12-01

    Due to the clinical advantages of Intensity Modulated Radiation Therapy (IMRT) high flexibility and accuracy in intensity modulated dose delivery is desirable to really maximize treatment outcome. Although it is possible to deliver IMRT by using broad beams in combination with dynamic multileaf collimation the process is rather time consuming and inefficient. By using narrow scanned high energy photon beams the treatment outcome can be improved, the treatment time reduced and accurate 3D in vivo dose delivery monitoring is possible by PET-CT based dose delivery imaging of photo nuclear reactions in human tissues. Narrow photon beams can be produced by directing a low emittance high energy electron beam on a thin target, and then cleaning the therapeutic photon beam from transmitted high energy electrons, and photon generated charged leptons, with a dedicated purging magnet placed directly downstream of the target. To have an effective scanning and purging magnet system the purging magnet should be placed immediately after the bremsstrahlung target to deflect the transmitted electrons to an efficient electron stopper. In the static electron stopper the electrons should be safely collected independent of the desired direction of the therapeutic scanned photon beam. The SID (Source to Isocenter Distance) should preferably be short while retaining the ability to scan over a large area on the patient and consequently there are severe requirements both on the strength and the geometry of the scanning and purging magnets. In the present study an efficient magnet configuration with a purging and scanning magnet assembly is developed for electron energies in the 50-75 MeV range and a SID of 75 cm. For a bremsstrahlung target of 3 mm Be these electron energies produce a photon beam of 25-17 mm FWHM (Full Width Half Maximum) at a SID of 75 cm. The magnet system was examined both in terms of the efficiency in scanning the narrow bremsstrahlung beam and the deflection of

  17. Development of an efficient scanning and purging magnet system for IMRT with narrow high energy photon beams

    International Nuclear Information System (INIS)

    Due to the clinical advantages of Intensity Modulated Radiation Therapy (IMRT) high flexibility and accuracy in intensity modulated dose delivery is desirable to really maximize treatment outcome. Although it is possible to deliver IMRT by using broad beams in combination with dynamic multileaf collimation the process is rather time consuming and inefficient. By using narrow scanned high energy photon beams the treatment outcome can be improved, the treatment time reduced and accurate 3D in vivo dose delivery monitoring is possible by PET-CT based dose delivery imaging of photo nuclear reactions in human tissues. Narrow photon beams can be produced by directing a low emittance high energy electron beam on a thin target, and then cleaning the therapeutic photon beam from transmitted high energy electrons, and photon generated charged leptons, with a dedicated purging magnet placed directly downstream of the target. To have an effective scanning and purging magnet system the purging magnet should be placed immediately after the bremsstrahlung target to deflect the transmitted electrons to an efficient electron stopper. In the static electron stopper the electrons should be safely collected independent of the desired direction of the therapeutic scanned photon beam. The SID (Source to Isocenter Distance) should preferably be short while retaining the ability to scan over a large area on the patient and consequently there are severe requirements both on the strength and the geometry of the scanning and purging magnets. In the present study an efficient magnet configuration with a purging and scanning magnet assembly is developed for electron energies in the 50-75 MeV range and a SID of 75 cm. For a bremsstrahlung target of 3 mm Be these electron energies produce a photon beam of 25-17 mm FWHM (Full Width Half Maximum) at a SID of 75 cm. The magnet system was examined both in terms of the efficiency in scanning the narrow bremsstrahlung beam and the deflection of

  18. Development of the magnetic septa for the slow beam extraction from the J-PARC main ring

    International Nuclear Information System (INIS)

    The magnetic septa have been developed for the slow extraction from the J-PARC Main Ring (MR) to the Hadron Experimental Facility. They consist of two thin magnetic septa (SMS1), four medium thick septa (SMS2) and four thick septa (SMS3). The thinnest septum conductor is 1.5 mm thick. The typical operating current is DC 3000 A and the total kick angle with the 30 GeV proton beam is 77 mrad. The magnets of SMS1 and SMS2 are placed in the vacuum chambers with the diameter of 660 mm, and the chambers can be aligned remotely by stepping motors in the range of ±5mm, which enable us to minimize the beam loss by the magnetic septa. The septa were installed in the MR in December 2008, and were successfully operated in the beam time for the slow beam extraction in January and February 2009, which resulted in the first 30GeV beam delivery to the Hadron Experimental Facility. (author)

  19. Research and development of an electron beam focusing system for a high-brightness X-ray generator

    OpenAIRE

    Sakai, Takeshi; Ohsawa, Satoshi; Sakabe, Noriyoshi; Sugimura, Takashi; IKEDA, Mitsuo

    2010-01-01

    A new type of rotating anticathode X-ray generator, where an electron beam of up to 60 keV irradiates the inner surface of a U-shaped Cu anticathode, has achieved a beam brilliance of 130 kW mm−2 (at 2.3 kW). A higher-flux electron beam is expected from simulation by optimizing the geometry of a combined-function-type magnet instead of the fringing field of the bending magnet. In order to minimize the size of the X-ray source the electron beam has been focused over a short distance by a new c...

  20. Investigation of ion induced bending mechanism for nanostructures

    International Nuclear Information System (INIS)

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