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. Bending magnets for the CBA beam-transport line

    Energy Technology Data Exchange (ETDEWEB)

    Thern, R.E.

    1983-01-01

    The beam-transport line from the AGS to CBA requires 68 large bending magnets, consisting of pure dipoles and two types of combined function gradient magnets. All three types were designed with magnetic-field calculation program POISSON, using the same exterior dimensions and coil package. The design goal of +-1% momentum acceptance for the transport line required a wide horizontal aperture, with a much-smaller vertical aperture for economy. Two prototypes of one gradient magnet were built, and a facility constructed to measure them and the later production magnets. Measurements were done using both a long coil and a point coil (Rawson-Lush gaussmeter). Preliminary results show ..delta..B/B < 0.2 x 10/sup -3/, ..delta..G/G < 0.3 x 10/sup -2/, and ..delta..B/sub 2//B < 0.3 x 10/sup -4/ cm/sup -2/ over the beam aperture. Due to end effects, the actual gradient differs from the design gradient by 1%, which has been compensated for in the beam-line design.

  3. 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...

  4. 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...

  5. 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.

  6. 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

  7. Electron cooling device without bending magnets

    Science.gov (United States)

    Sharapa, A. N.; Shemyakin, A. V.

    1993-11-01

    The scheme of an axisymmetric electron cooling device without bending magnets is proposed. Solutions for the most important elements, i.e., a gun and a recuperator, are considered. The main characteristics of the recuperator of the Faraday cup type having a reflector and a gun with a ring emitter are explored. In the gun, the beam is formed, the diameter of which is 40 mm and the dimension of a disturbance region is several millimeters.

  8. Sorting of bending magnets for the SSRF booster

    Institute of Scientific and Technical Information of China (English)

    HOU Jie; LIU Gui-Min; LI Hao-Hu; ZHANG Man-Zhou

    2008-01-01

    The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.

  9. Sorting of bending magnets for the SSRF booster

    Science.gov (United States)

    Hou, Jie; Liu, Gui-Min; Li, Hao-Hu; Zhang, Man-Zhou

    2008-04-01

    The Shanghai Synchrotron Radiation Facility (SSRF)booster ring, a full energy injector for the storage ring, is deigned to accelerate the electron beam energy from 150 MeV to 3.5 GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping. Closed orbit distortion (COD) caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting. Considering the affections of random errors in measurement, both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5 is given as the final installation sequence of the booster bending magnets in this paper. Supported by SSRF Project

  10. Oide Effect and Radiation in Bending Magnets

    CERN Document Server

    Blanco, Oscar; Bambade, Philip

    2014-01-01

    Including radiation effects during lattice design optimization is crucial in high energy accelerators. Oide effect and radiation in bending magnets are reviewed aiming to include them in the optical design process to minimize the IP beam size. The Oide double integral is expressed in simpler terms in order to speed up calculations, concluding in how longer quadrupoles with lower gradients may help reducing the Oide effect. Radiation in bending magnets is reviewed for linear lattices, generalizing to the case when the final dispersion is different from zero and making comparisons with theoretical results and particle tracking. An agreement between the theory, the implemented approximation included in MAPCLASS2 and the six-dimensional tracking in PLACET has been found.

  11. 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...

  12. 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).

  13. 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...

  14. 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).

  15. slice of a LEP bending magnet

    CERN Multimedia

    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.

  16. Slice of a LEP bending magnet

    CERN Multimedia

    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.

  17. 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.)

  18. 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.

  19. 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.

  20. PERMEABILITY OF SALTSTONE MEASUREMENT BY BEAM BENDING

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J; Tommy Edwards, T; Vickie Williams, V

    2008-01-30

    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{sup -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

  1. 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

  2. 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.

  3. Tilted bending magnet for SPS target area TCC2

    CERN Multimedia

    1976-01-01

    A slow-extracted proton beam from the SPS goes to the underground target zone TCC2. The part of the primary beam which traverses target T4 is recuperated and transported over some 800 m, for further use in the North Area High Intensity facility (NAHIF). The curved and sloped trajectory required 4 of the bending magnets to be tilted. Here we see one of them being attended by Gilbert Françon in hall 867, ready for installation in TCC2.

  4. 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.

  5. 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.

  6. System effects influencing the bending strength of timber beams

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Källsner, B.

    1998-01-01

    A stochastic model of hierarchical series system type for the bending strength of spruce beams isdefined from the anticipation that the bending failure takes place at a cross-section with a defect cluster formed by knots or grain irregularities. The parameters of the model are estimated from meas...

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Polarization-independent self-collimating bends and beam splitters in photonic crystals

    Institute of Scientific and Technical Information of China (English)

    Xiaopeng Shen; Kui Han; Xianqing Yang; Yifeng Shen; Haipeng Li; Gang Tang; Zhitian Guo

    2007-01-01

    Polarization independent bends and beam splitters for transverse electric (TE) and transverse magnetic (TM) polarizations have been demonstrated in two-dimensional (2D) photonic crystals (PhCs). In virtuel of equi-frequency contour analysis and finite-difference time-domain calculations, self-collimation behaviors for TE- and TM-polarizations are achieved at the same frequency. Simulation results show a 90-degree bend with 90% efficiency and beam splitters with about 96% total efficiency for both TE- and TMpolarizations, where the light is self-guided by the self-collimation effect. Such bends and beam splitters are expected to play important roles in optical devices where polarization insensitivity is needed.

  12. 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).

  13. Size Effects on the Bending Behaviour of Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Brincker, Rune; Henriksen, M. S.; Christensen, F. A.;

    1999-01-01

    Load-deformation curves for reinforced concrete beams subjected to bending show size effects due to tensile failure of the concrete at early stages in the failure process and due to compression failure of the concrete when the final failure takes place. In this paper these effects are modelled...

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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

  19. Optical guiding and beam bending in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Scharlemann, E.T.

    1987-01-01

    The electron beam in a free-electron laser (FEL) can act as an optical fiber, guiding or bending the optical beam. The refractive and gain effects of the bunched electron beam can compensate for diffraction, making possible wigglers that are many Rayleigh ranges (i.e., characteristic diffraction lengths) long. The origin of optical guiding can be understood by examining gain and refractive guiding in a fiber with a complex index of refraction, providing a mathematical description applicable also to the FEL, with some extensions. In the exponential gain regime of the FEL, the electron equations of motion must be included, but a self-consistent description of exponential gain with diffraction fully included becomes possible. The origin of the effective index of refraction of an FEL is illustrated with a simple example of bunched, radiating dipoles. Some of the properties of the index of refraction are described. The limited experimental evidence for optical beam bending is summarized. The evidence does not yet provide conclusive proof of the existence of optical guiding, but supports the idea. Finally, the importance of refractive guiding for the performance of a high-gain tapered-wiggler FEL amplifier is illustrated with numerical simulations.

  20. 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.

  1. 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)

  2. 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).

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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).

  9. 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

  10. Numerical analysis of sandwich beam with corrugated core under three-point bending

    Energy Technology Data Exchange (ETDEWEB)

    Wittenbeck, Leszek [Poznan University of Technology, Institute of Mathematics Piotrowo Street No. 5, 60-965 Poznan (Poland); Grygorowicz, Magdalena; Paczos, Piotr [Poznan University of Technology, Institute of Applied Mechanics Jana Pawla IIStreet No. 24, 60-965 Poznan (Poland)

    2015-03-10

    The strength problem of sandwich beam with corrugated core under three-point bending is presented.The beam are made of steel and formed by three mutually orthogonal corrugated layers. The finite element analysis (FEA) of the sandwich beam is performed with the use of the FEM system - ABAQUS. The relationship between the applied load and deflection in three-point bending is considered.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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...

  17. Bending analysis of a functionally graded piezoelectric cantilever beam

    Institute of Scientific and Technical Information of China (English)

    YU Tao; ZHONG Zheng

    2007-01-01

    A new analysis based on Airy stress function method is presented for a functionally graded piezoelectric material cantilever beam.Assuming that the mechanical and electric properties of the material have the same variations along the thickness direction,a two-dimensional plane elasticity solution is obtained for the coupling electroelastic fields of the beam under different loadings.This solution will be useful in analyzing FGPM beam with arbitrary variations of material properties.The influences of the functionally graded material properties on the structural response of the beam subjected to different loads are also studied through numerical examples.

  18. Bending analysis of a functionally graded piezoelectric cantilever beam

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new analysis based on Airy stress function method is presented for a functionally graded piezoelectric material cantilever beam. Assuming that the mechanical and electric properties of the material have the same variations along the thickness direction, a two-dimensional plane elasticity solution is obtained for the coupling electroelastic fields of the beam under different loadings. This solution will be useful in analyzing FGPM beam with arbitrary variations of material properties. The influences of the functionally graded material properties on the structural response of the beam subjected to different loads are also studied through numerical examples.

  19. Bending and torsional vibration control of composite beams through intelligent constrained-layer damping treatments

    Science.gov (United States)

    Shen, I. Y.

    1995-05-01

    This paper is to develop a mathematical model to predict bending, twisting, and axial vibration response of a composite beam with intelligent constrained layer (ICL) or active constrained layer (ACL) damping treatments. In addition, preliminary experiments are conducted on composite beams to evaluate this new technique. The ICL composite beam model is obtained by integrating the existing ICL composite plate model proposed by Shen. When the plate width (along the x-axis) is much smaller than the plate length (along the y-axis), integration of the ICL composite plate equations and linearization of displacement fields with respect to x leads to a set of equations that couples bending, tosional, and axial vibrations of a composite beam. The equations of motion and associated boundary conditions are normalized and rearranged in a state-space matrix form, and the vibration response is predicted through the distributed transfer function method developed by Yang and Tan. A numerical example is illustrated on a composite beam with bending-torsion coupling stiffness. Numerical results show that ICL damping treatments may or may not reduce coupled bending and torsional vibrations of a composite beam simultaneously. When the deflection is fed back to actuate the ICL damping treatment, a sensitivity analysis shows that only those vibration modes with significant bending response are suppressed simultaneously with their torsional components. In the preliminary experiments, two different ICL setups are tested on a composite beam without bending-torsion coupling. Damping performance of both ICL setups agrees qualitatively with existing mathematical models and experimental results obtained from other researchers. The damping performance, however, is not optimized due to the availability of materials and their dimensions in the laboratory. An optimization strategy needs to be developed to facilitate design of ACL damping treatments with maximized damping performance.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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...

  7. 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.

  8. 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...

  9. 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...

  10. 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.

  11. An experimental-theoretical correlation study of non-linear bending and torsion deformations of a cantilever beam

    Science.gov (United States)

    Dowell, E. H.; Traybar, J.; Hodges, D. H.

    1977-01-01

    An experimental study of the large deformation of a cantilevered beam under a gravity tip load has been made. The beam root is rotated so that the tip load is oriented at various angles with respect to the beam principal axes. Static twist and bending deflections of the tip and bending natural frequencies have been measured as a function of tip load magnitude and orientation. The experimental data are compared with the results of a recently developed non-linear structural theory. Agreement is reasonably good when bending deflections are small compared to the beam span, but systematic differences occur for larger deflections.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. Improvement for design of beam structures in large vibrating screen considering bending and random vibration

    Institute of Scientific and Technical Information of China (English)

    彭利平; 刘初升; 宋宝成; 武继达; 王帅

    2015-01-01

    Demand for large vibrating screen is huge in the mineral processing industry. As bending and random vibration are not considered in a traditional design method for beam structures of a large vibrating screen, fatigue damage occurs frequently to affect the screening performance. This work aims to conduct a systematic mechanics analysis of the beam structures and improve the design method. Total motion of a beam structure in screening process can be decomposed into the traditional followed rigid translation (FRT), bending vibration (BV) and axial linear-distributed random rigid translation (ALRRT) excited by the side-plates. When treated as a generalized single-degree-of-freedom (SDOF) elastic system analytically, the BV can be solved by the Rayleigh’s method. Stochastic analysis for random process is conducted for the detailed ALRRT calculation. Expressions for the mechanics property, namely, the shearing force and bending-moment with respect to BV and ALRRT, are derived, respectively. Experimental and numerical investigations demonstrate that the largest BV exists at the beam center and can be nearly ignored in comparison with the FRT during a simplified engineering design. With the BV and FRT considered, the mechanics property accords well with the practical situation with the maximum error of 6.33%, which is less than that obtained by traditional method.

  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. 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.

  19. Effect of nondestructive testing of laminations on the bending properties of glulam beams made from louro-vermelho (Sextonia rubra

    Directory of Open Access Journals (Sweden)

    Ricardo Faustino Teles

    2010-03-01

    Full Text Available This work aims to assess the bending properties of glued laminated timber beams (glulam manufactured with species red louro (Sextonia rubra. Laminations were nondestructively tested using the transverse vibration method (EMlam. Then 10 glulam beams were manufactured and tested in static bending according to ASTM D 198 standard, having modulus of elasticity (EM, modulus of rupture (fM, and bending moment (M determined. The finished beams were also tested by the transverse vibration method (EMvt. It was noted that the EMvt value was only 2% lower than the EM value. Using laminations with a high modulus of elasticity did allow effective gain in stiffness. Therefore, results indicate that the transverse vibration method is a valid, reliable technique both for testing glulam laminations and for assessing stiffness in finished beams. Bending properties in glulam beams were influenced by the stiffness of constituent laminations.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. Asymmetry in the effect of magnetic field on photon detection and dark counts in bended nanostrips

    CERN Document Server

    Semenov, A; Lusche, R; Ilin, K; Siegel, M; Hubers, H -W; Bralovic, N; Dopf, K; Vodolazov, D Yu

    2015-01-01

    Current crowding in the bends of superconducting nano-structures not only restricts measurable critical current in such structures but also redistributes local probabilities for dark and light counts to appear. Using structures from strips in the form of a square spiral which contain bends with the very same curvature with respect to the directions of bias current and external magnetic field, we have shown that dark counts as well as light count at small photon energies originate from areas around the bends. The minimum in the rate of dark counts reproduces the asymmetry of the maximum critical current density as function of the magnetic field. Contrary, the minimum in the rate of light counts demonstrate opposite asymmetry. The rate of light counts become symmetric at large currents and fields. Comparing locally computed absorption probabilities for photons and the simulated threshold detection current we found approximate location of areas near bends which deliver asymmetric light counts. Any asymmetry is a...

  7. 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.

  8. 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.)

  9. 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

  10. 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

  11. ANALYTICAL SOLUTION FOR BENDING BEAM SUBJECT TO LATERAL FORCE WITH DIFFERENT MODULUS

    Institute of Scientific and Technical Information of China (English)

    姚文娟; 叶志明

    2004-01-01

    A bending beam,subjected to state of plane stress,was chosen to investigate.The determination of the neutral surface of the structure was made,and the calculating formulas of neutral axis,normal stress,shear stress and displacement were derived.It is concluded that, for the elastic bending beam with different tension-compression modulus in the condition of complex stress, the position of the neutral axis is not related with the shear stress, and the analytical solution can be derived by normal stress used as a criterion, improving the multiple cyclic method which determines the position of neutral point by the principal stress. Meanwhile, a comparison is made between the results of the analytical solution and those calculated from the classic mechanics theory, assuming the tension modulus is equal to the compression modulus, and those from the finite element method (FEM) numerical solution. The comparison shows that the analytical solution considers well the effects caused by the condition of different tension and compression modulus. Finally, a calculation correction of the structure with different modulus is proposed to optimize the structure.

  12. 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.

  13. 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.

  14. The solution of minimum reliability index for modified weak point of arbitrary curved beam under pure bending

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper is based on the fundamental loading model of pure bending and the analytical model of a circular beam element with arbitrary initial deflection. The L.W. Guo solution is modified and generalized according to the elastic theory, and the analytical solution for the stress of the beam element with arbitrary initial deflection under pure bending is derived. Using yield theory of edge strength, an expression for the safety margin of one point in the arbitrary curved beam under pure bending (ACPB) is built. This paper modifies the model for weak points of service structures and establishes a foundation for safe design and inspection of imperfect structures. Also, according to the theory of the method of advanced first-order second-moment(AFOSM), this paper derives an expression for the reliability index of one point in ACPB. Lastly, it modifies the solution for weak points by solving the minimal reliability index.

  15. Determine Bending Moment of Plane Bending Beam by Graphical Method%用图解法确定平面弯曲梁的弯矩

    Institute of Scientific and Technical Information of China (English)

    闫志琴

    2014-01-01

    针对传统“解析法”的弊端,利用剪力图中剪力所围区域面积的代数量与弯矩图中的弯矩代数量间存在一一对应关系的特点,采用“图解法”介绍了求解、校核平面弯曲梁强度和刚度的核心内容———弯矩值,凸显了图解法快速、准确、易学、深刻记忆的优点。%Aiming at shortcomings of conventional analytical method and utilizing the characteristic of the one to one correspon‐dence between the algebra of area surrounding by shearing force and algebra of bending moment in bending moment diagram ,in this paper ,we introduced the utilization of graphical method to solve and check bending moment value which is the core contents of intensity and rigidity of plane bending beam .Our graphical method highlights the advantage of the novel method:rapidity ,ac‐curacy ,learnability ,and profound memory .

  16. The effect of transverse shear on the face sheets failure modes of sandwich beams loaded in three points bending

    Directory of Open Access Journals (Sweden)

    BOUROUIS FAIROUZ

    2012-04-01

    Full Text Available Sandwich beams loaded in three points bending may fail in several ways including tension or compression failure of facings. In this paper , The effect of the transverse shear on the face yielding and face wrinkling failure modes of sandwich beams loaded in three points bending have been studied, the beams were made of various composites materials carbon/epoxy, kevlar/epoxy, glass/epoxy at sequence [+θ/-θ]3s, [0°/90°]3s. . The stresses in the face were calculated using maximum stress criterion and the simple beam theory. The obtained different results show that the sandwich beams with carbon/epoxy, and glass/epoxy face sheets are the best materials, inreturn the kevlar /epoxy facing characterised by low resistance of transverse shear in compression and tensile.

  17. Beam loss reduction by magnetic shielding using beam pipes and bellows of soft magnetic materials

    Science.gov (United States)

    Kamiya, J.; Ogiwara, N.; Hotchi, H.; Hayashi, N.; Kinsho, M.

    2014-11-01

    One of the main sources of beam loss in high power accelerators is unwanted stray magnetic fields from magnets near the beam line, which can distort the beam orbit. The most effective way to shield such magnetic fields is to perfectly surround the beam region without any gaps with a soft magnetic high permeability material. This leads to the manufacture of vacuum chambers (beam pipes and bellows) with soft magnetic materials. A Ni-Fe alloy (permalloy) was selected for the material of the pipe parts and outer bellows parts, while a ferritic stainless steel was selected for the flanges. An austenitic stainless steel, which is non-magnetic material, was used for the inner bellows for vacuum tightness. To achieve good magnetic shielding and vacuum performances, a heat treatment under high vacuum was applied during the manufacturing process of the vacuum chambers. Using this heat treatment, the ratio of the integrated magnetic flux density along the beam orbit between the inside and outside of the beam pipe and bellows became small enough to suppress beam orbit distortion. The outgassing rate of the materials with this heat treatment was reduced by one order magnitude compared to that without heat treatment. By installing the beam pipes and bellows of soft magnetic materials as part of the Japan Proton Accelerator Research Complex 3 GeV rapid cycling synchrotron beam line, the closed orbit distortion (COD) was reduced by more than 80%. In addition, a 95.5% beam survival ratio was achieved by this COD improvement.

  18. 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.

  19. The Superconducting Horizontal Bend Magnet for the Jefferson Lab's 11 GeV/c Super High Momentum Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    S. Chouhan, J. DeKamp, A. Zeller, P. Brindza, S. Lassiter, M. Fowler, E. Sun

    2010-06-01

    A collaboration between NSCL and Jlab has developed the reference design and coil winding for Jlab's Super High Momentum Spectrometer (SHMS) horizontal bend magnet. A warm iron ??C?? type superferric dipole magnet will bend the 12 GeV/c particles horizontally by 3?? to allow the SHMS to reach angles as low as 5.5??. This requires an integral field strength of up to 2.1 T.m. The major challenges are the tight geometry, high and unbalanced forces and a required low fringe field in primary beam path. A coil design based on flattened SSC Rutherford cable that provides a large current margin and commercially available fiberglass prepreg epoxy tape has been developed. A complete test coil has been wound and will be cold tested. This paper present the modified magnet design includes coil forces, coil restraint system and fringe field. In addition, coil properties, quench calculations and the full mechanical details are also presented.

  20. Electrostatic tuning of the bending stiffness of a large scale GFRP-CFRP beam

    Science.gov (United States)

    Bergamini, A.; Christen, R.; Motavalli, M.

    2006-03-01

    The suppression of vibrations of a structure is commonly considered a necessary measure for the extension of its lifetime, when high amplitude vibrations are observed. As an alternative to the introduction of discrete damping devices, the modification of the stiffness of a beam is proposed as a means to suppress vibrations due to resonance, thank to the ability to reject mechanical energy input at specific frequencies. Previous work has outlined the principle and the potential advantages of such an approach based on the behavior of a small scale system. In order to confirm the feasibility of the approach on macro-scale systems, such as a light weight pedestrian bridge, experiments for the tuning of a 2.5 m long glass fiber reinforced polymer I-beam were performed. The results of the experiments show that it is possible to modify the bending stiffness of structural elements that can be used for real life engineering applications. Measurements show that it is possible to shift the resonance peak of a beam while maintaining a reasonably good q-factor in the transfer function, thus indicating that the change in behavior happens in connection with an increased stiffness rather than with the introduction of substantial damping. Based on the presented feasibility study, the development of an adaptive bridge deck will be considered.

  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. 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.).

  3. 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

  4. Focusing, collimation and flux throughput at the IMCA-CAT bending-magnet beamline at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Koshelev, Irina; Huang, Rong; Graber, Timothy; Meron, Mati; Muir, J. Lewis; Lavender, William; Battaile, Kevin; Mulichak, Anne M.; Keefe, Lisa J.; (IIT); (UC)

    2009-09-02

    The IMCA-CAT bending-magnet beamline was upgraded with a collimating mirror in order to achieve the energy resolution required to conduct high-quality multi- and single-wavelength anomalous diffraction (MAD/SAD) experiments without sacrificing beamline flux throughput. Following the upgrade, the bending-magnet beamline achieves a flux of 8 x 10{sup 11} photons s{sup -1} at 1 {angstrom} wavelength, at a beamline aperture of 1.5 mrad (horizontal) x 86 {mu}rad (vertical), with energy resolution (limited mostly by the intrinsic resolution of the monochromator optics) {delta}E/E = 1.5 x 10{sup -4} (at 10 kV). The beamline operates in a dynamic range of 7.5-17.5 keV and delivers to the sample focused beam of size (FWHM) 240 {micro}m (horizontally) x 160 {micro}m (vertically). The performance of the 17-BM beamline optics and its deviation from ideally shaped optics is evaluated in the context of the requirements imposed by the needs of protein crystallography experiments. An assessment of flux losses is given in relation to the (geometric) properties of major beamline components.

  5. Focusing, collimation and flux throughput at the IMCA-CAT bending-magnet beamline at the Advanced Photon Source.

    Science.gov (United States)

    Koshelev, Irina; Huang, Rong; Graber, Timothy; Meron, Mati; Muir, J Lewis; Lavender, William; Battaile, Kevin; Mulichak, Anne M; Keefe, Lisa J

    2009-09-01

    The IMCA-CAT bending-magnet beamline was upgraded with a collimating mirror in order to achieve the energy resolution required to conduct high-quality multi- and single-wavelength anomalous diffraction (MAD/SAD) experiments without sacrificing beamline flux throughput. Following the upgrade, the bending-magnet beamline achieves a flux of 8 x 10(11) photons s(-1) at 1 A wavelength, at a beamline aperture of 1.5 mrad (horizontal) x 86 microrad (vertical), with energy resolution (limited mostly by the intrinsic resolution of the monochromator optics) deltaE/E = 1.5 x 10(-4) (at 10 kV). The beamline operates in a dynamic range of 7.5-17.5 keV and delivers to the sample focused beam of size (FWHM) 240 microm (horizontally) x 160 microm (vertically). The performance of the 17-BM beamline optics and its deviation from ideally shaped optics is evaluated in the context of the requirements imposed by the needs of protein crystallography experiments. An assessment of flux losses is given in relation to the (geometric) properties of major beamline components.

  6. Upgrade of IMCA-CAT Bending Magnet Beamline 17-BM for Macromolecular Crystallography at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Koshelev, I.; Huang, R.; Graber, T.; Meron, M.; Muir, J.L.; Lavender, W.; Battaile, K.; Mulichak, A.M.; Keefe, L.J. (UC)

    2007-05-15

    Pharmaceutical research depends on macromolecular crystallography as a tool in drug design and development. To solve the de novo three-dimensional atomic structure of a protein, it is essential to know the phases of the X-rays scattered by a protein crystal. Experimental phases can be obtained from multiwavelength anomalous dispersion (MAD) experiments. Dedicated to macromolecular crystallography, the IMCA-CAT bending magnet beamline at sector 17 of the Advanced Photon Source (APS) was upgraded to provide the energy resolution required to successfully perform synchrotron radiation-based MAD phasing of protein crystal structures. A collimating mirror was inserted into the beam path upstream of a double-crystal monochromator, thus increasing the monochromatic beam throughput in a particular bandwidth without sacrificing the energy resolution of the system. The beam is focused horizontally by a sagittally bent crystal and vertically by a cylindrically bent mirror, delivering a beam at the sample of 130 {micro}m (vertically) x 250 {micro}m (horizontally) FWHM. As a result of the upgrade, the beamline now operates with an energy range of 7.5 x 17.5 keV, delivers 8 x 10{sup +11} photons/sec at 12.398 keV at the sample, and has an energy resolution of {delta}E/E = 1.45 x 10{sup -4} at 10 keV, which is suitable for MAD experiments.

  7. 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%.

  8. 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.

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ilin, Konstantin, E-mail: konstantin.ilin@kit.edu; Siegel, Michael, E-mail: michael.siegel@kit.edu

    2014-08-15

    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 I{sub C} 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 I{sub C} 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.

  11. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, John P., E-mail: john.sutter@diamond.ac.uk; Dolbnya, Igor P.; Collins, Stephen P. [Diamond Light Source Ltd., Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Harris, Kenneth D. M.; Edwards-Gau, Gregory R. [School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales (United Kingdom); Palmer, Benjamin A. [Department of Structural Biology, Weizmann Institute of Science, 234 Herzl St., Rehovot 7610001 (Israel)

    2015-04-28

    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.

  13. Photon beam studies of magnetic materials

    Science.gov (United States)

    Lovesey, S. W.

    1994-06-01

    The past decade has seen a surge of activity in the use of photon beam techniques to study magnetic properties of materials. By and large, in this period the experimental work has been accomplished with beams produced by electron synchrotron facilities. To date, it is fair to say that the surge of activity is underpinned by improvements in instrument performance, enjoyed at synchrotron sources, rather than outstanding intellectual advances. In consequence, improvements in the intensity at the sample, and the provision of good beams of polarized photons, which enable polarization induced discrimination effects to be exploited as a means of increasing the signal-to-noise, are particularly significant in the use for magnetic studies of photon beam techniques.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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

  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. 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.

  2. 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.

  3. 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.

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

    Science.gov (United States)

    Chen, S. N.; Gauthier, M.; Higginson, D. P.; Dorard, S.; Mangia, F.; Riquier, R.; Atzeni, S.; Marquès, J.-R.; Fuchs, J.

    2014-04-01

    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.

  5. 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.

  6. 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...

  7. 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.

  8. 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)

  9. 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

  10. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, M; MacDowell, A A; Caldwell, W A; Cambie, D; Celestre, R S; Domning, E E; Duarte, R M; Gleason, A; Glossinger, J; Kelez, N; Plate, D W; Yu, T; Zaug, J M; Padmore, H A; Jeanloz, R; Alivisatos, A P; Clark, S M

    2005-04-19

    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/{Delta}E {approx} 7000) and a W/B{sub 4}C multilayer (E/{Delta}E {approx} 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

    2005-06-30

    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/DE {approx}7000) and a W/B4C multilayers (E/DE {approx} 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.

  13. 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.

  14. 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).

  15. 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.

  16. 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.

  17. 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.

  18. DESIGN OF BEAM-EXTRACTION SEPTUM MAGNET FOR THE SNS.

    Energy Technology Data Exchange (ETDEWEB)

    TSOUPAS,N.; LEE,Y.Y.; RANK,J.; TUOZZOLO,J.

    2001-06-18

    The beam-extraction process from the SNS accumulator ring [1,2] requires a Lambertson septum magnet. In this paper we discuss the geometrical and magnetic field requirements of the magnet and present results obtained from two and three dimensional magnetic field calculations that shows the field quality in the regions of interest of the septum magnet.

  19. 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.

  20. 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...

  1. 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.

  2. 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.

  3. Observability of pulsar beam bending by the Sgr~A* black hole

    CERN Document Server

    Stovall, Kevin; Price, Richard H; Jenet, Fredrick A

    2011-01-01

    According to some models, there may be a significant population of radio pulsars in the Galactic center. In principle, a beam from one of these pulsars could pass close to the supermassive black hole (SMBH) at the center, be deflected, and be detected by Earth telescopes. Such a configuration would be an unprecedented probe of the properties of spacetime in the moderate- to strong-field regime of the SMBH. We present here background on the problem, and approximations for the probability of detection of such beams. We conclude that detection is marginally probable with current telescopes, but that telescopes that will be operating in the near future, with an appropriate multiyear observational program, will have a good chance of detecting a beam deflected by the SMBH.

  4. 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.

  5. The Superconducting Magnets of the ILC Beam Delivery System

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.; Anerella, M.; Escallier, J.; He, P.; Jain, A.; Marone, A.; /Brookhaven; Nosochkov, Y.; Seryi, Andrei; /SLAC

    2007-09-28

    The ILC Beam Delivery System (BDS) uses a variety of superconducting magnets to maximize luminosity and minimize background. Compact final focus quadrupoles with multifunction correction coils focus incoming beams to few nanometer spot sizes while focusing outgoing disrupted beams into a separate extraction beam line. Anti-solenoids mitigate effects from overlapping focusing and the detector solenoid field. Far from the interaction point (IP) strong octupoles help minimize IP backgrounds. A low-field but very large aperture dipole is integrated with the detector solenoid to reduce backgrounds from beamstrahlung pairs generated at the IP. Physics requirements and magnetic design solutions for the BDS superconducting magnets are reviewed in this paper.

  6. 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

  7. 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.

  8. Impact of Dynamic Magnetic fields on the CLIC Main Beam

    CERN Document Server

    Snuverink, J; Jach, C; Jeanneret, JB; Schulte, D; Stulle, F

    2010-01-01

    The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the position of the beam. The beam position will be sensitive to external dynamic magnetic fields (stray fields) in the nanotesla regime. The impact of these fields on the CLIC main beam has been studied by performing simulations on the lattices and tolerances have been determined. Several mitigation techniques will be discussed.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. Measuring permeability, Young's modulus, and stress relaxation by the beam-bending technique

    Science.gov (United States)

    Vichit-Vadakan, Wilasa

    Recent interest in the permeability of cement paste, mortars, and concrete lies in the need to gain further understanding of mechanisms affecting the durability of these materials. Conventional techniques for measuring permeability are cumbersome and often take days to complete just one measurement. This thesis proposes a new technique for measuring the permeability. The advantage of this technique is that the results are obtained in a few minutes to a few hours; moreover, there is no problem with leaks or need for high pressures. The method is particularly well suited for examining the changes in permeability and viscoelastic properties of young cement paste samples. When a saturated rod of a porous material is instantaneously deflected under three-point bending, two types of relaxation processes occur simultaneously: hydrodynamic relaxation, caused by the flow of liquid in the porous body to restore ambient pressure, and viscoelastic relaxation of the solid network. By measuring the decrease in the force required to sustain a constant deflection, it is possible to obtain the permeability and Young's modulus from the hydrodynamic relaxation function, in addition to the stress relaxation function of the sample. The exact viscoelastic solution is developed and the total relaxation is shown to be very closely approximated as the product of the hydrodynamic and stress relaxation functions. The analytical results are verified on porous VycorRTM glass saturated in various solvents, including normal alcohols, water, and glycerol. The results show excellent agreement with the theory. Consistent with observations of previous workers, the permeability is found to be influenced by the size of the solvent molecule; by assuming that the pore surfaces are covered with a monolayer of immobile solvent, the observed variation can be explained. The evolution of the permeability, Young's modulus, and stress relaxation function are reported for Type III Portland cement paste with

  16. 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.

  17. 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.

  18. 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

  19. Testing beam-induced quench levels of LHC superconducting magnets

    Science.gov (United States)

    Auchmann, B.; Baer, T.; Bednarek, M.; Bellodi, G.; Bracco, C.; Bruce, R.; Cerutti, F.; Chetvertkova, V.; Dehning, B.; Granieri, P. P.; Hofle, W.; Holzer, E. B.; Lechner, A.; Nebot Del Busto, E.; Priebe, A.; Redaelli, S.; Salvachua, B.; Sapinski, M.; Schmidt, R.; Shetty, N.; Skordis, E.; Solfaroli, M.; Steckert, J.; Valuch, D.; Verweij, A.; Wenninger, J.; Wollmann, D.; Zerlauth, M.

    2015-06-01

    In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with the top beam energies of 3.5 and 4 TeV per proton (from 2012) instead of the nominal 7 TeV. The currents in the superconducting magnets were reduced accordingly. To date only seventeen beam-induced quenches have occurred; eight of them during specially designed quench tests, the others during injection. There has not been a single beam-induced quench during normal collider operation with stored beam. The conditions, however, are expected to become much more challenging after the long LHC shutdown. The magnets will be operating at near nominal currents, and in the presence of high energy and high intensity beams with a stored energy of up to 362 MJ per beam. In this paper we summarize our efforts to understand the quench levels of LHC superconducting magnets. We describe beam-loss events and dedicated experiments with beam, as well as the simulation methods used to reproduce the observable signals. The simulated energy deposition in the coils is compared to the quench levels predicted by electrothermal models, thus allowing one to validate and improve the models which are used to set beam-dump thresholds on beam-loss monitors for run 2.

  20. 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.

  1. 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.

  2. 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.

  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. 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.

  5. 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...

  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. 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

  8. 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

  9. Testing beam-induced quench levels of LHC superconducting magnets

    CERN Document Server

    Auchmann, B; Bednarek, M; Bellodi, G; Bracco, C; Bruce, R; Cerutti, F; Chetvertkova, V; Dehning, B; Granieri, P P; Hofle, W; Holzer, E B; Lechner, A; Del Busto, E Nebot; Priebe, A; Redaelli, S; Salvachua, B; Sapinski, M; Schmidt, R; Shetty, N; Skordis, E; Solfaroli, M; Steckert, J; Valuch, D; Verweij, A; Wenninger, J; Wollmann, D; Zerlauth, M

    2015-01-01

    In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with the top beam energies of 3.5 TeV and 4 TeV per proton (from 2012) instead of the nominal 7 TeV. The currents in the superconducting magnets were reduced accordingly. To date only seventeen beam-induced quenches have occurred; eight of them during specially designed quench tests, the others during injection. There has not been a single beam- induced quench during normal collider operation with stored beam. The conditions, however, are expected to become much more challenging after the long LHC shutdown. The magnets will be operating at near nominal currents, and in the presence of high energy and high intensity beams with a stored energy of up to 362 MJ per beam. In this paper we summarize our efforts to understand the quench levels of LHC superconducting magnets. We describe beam-loss events and dedicated experiments with beam, as well as the simulation methods used to reproduce the observable signals. The simulated energy depositio...

  10. 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.

  11. 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....

  12. 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.

  13. 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.

  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. 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.

  16. 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.

  17. 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

  18. 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

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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。

  8. 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.

  9. 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)

  10. 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

  11. 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

  12. 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)

  13. Suppressing Transverse Beam Halo with Nonlinear Magnetic Fields

    CERN Document Server

    Webb, Stephen D; Abell, Dan T; Danilov, Viatcheslav; Nagaitsev, Sergei; Valishev, Alexander; Danilov, Kirill; Cary, John R

    2012-01-01

    High intensity proton storage rings are central for the development of advanced neutron sources, drivers for the production of pions in neutrino factories or muon colliders, and transmutation of radioactive waste. Fractional proton loss from the beam must be very small to prevent radioac- tivation of nearby structures, but many sources of beam loss are driven by collective effects that increase with intensity. Recent theoretical work on the use of nonlinear magnetic fields to design storage rings with integrable transverse dynamics is extended here to include collective effects, with numerical results showing validity in the presence of very high beam current. Among these effects is the formation of beam halo, where particles are driven to large amplitude oscillations by coherent space charge forces. The strong variation of particle oscillation frequency with amplitude results in nonlinear decoherence that is observed to suppress transverse halo development in the case studied. We also present a necessary gen...

  14. Optical properties and band bending of InGaAs/GaAsBi/InGaAs type-II quantum well grown by gas source molecular beam epitaxy

    Science.gov (United States)

    Pan, Wenwu; Zhang, Liyao; Zhu, Liang; Li, Yaoyao; Chen, Xiren; Wu, Xiaoyan; Zhang, Fan; Shao, Jun; Wang, Shumin

    2016-09-01

    Photoluminescence (PL) properties of In0.2Ga0.8As/GaAs0.96Bi0.04/In0.2Ga0.8As quantum well (QW) grown on GaAs substrates by gas source molecular beam epitaxy were studied by varying excitation power and temperature, respectively. The type-II transition energy shifts from 1.149 eV to 1.192 eV when increasing the excitation power from 10 mW to 150 mW at 4.5 K, which was ascribed to the band-bending effect. On the other hand, the type-II PL quenches quickly along with fast redshift with the increasing temperature due to the relaxation of the band bending caused by the thermal excitation process. An 8 band k.p model was used to analyze the electronic properties and the band-bending effect in the type-II QW. The calculated subband levels and transition energy fit well with the experiment results, and two thermal activation energies of 8.7 meV and 50 meV, respectively, are deduced.

  15. 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.

  16. CFRP布加固圆形木梁抗弯性能的试验%Experimental of Bending Behavior of Circular Timber Beams Strengthened with CFRP Sheets

    Institute of Scientific and Technical Information of China (English)

    欧阳煜; 李游

    2012-01-01

    In practice, most wood beams to be repaired have already been damaged or degraded. It is necessary to study the structural performances of damaged wood beams reinforced by carbon fiber reinforced polymer (CFRP) sheets. Based on static tests of 8 damaged circular timber beams strengthened with CFRP sheets, bending behaviors are studied, including failure characteristics, ultimate bearing capacity, rigidity, and strain of timber section. The results show that CFRP sheets have a good strengthening effect for timber beams. The loading capacity of a timber beam reinforced by CFRP is effectively enhanced. The results are useful to practical design.%对在实际工程中已经受损的木梁加固后的结构性能进行研究.通过对8根圆形木梁进行静力试验,研究碳纤维增强复合材料(carbon fiber reinforced polymer,CFRP)布加固受损木梁的抗弯性能,包括破坏特性、极限荷载、刚度、截面应变等结构性能.试验结果表明,CFRP布加固受损木梁具有良好的效果,能够有效提高木梁的承载力和刚度.研究结论对碳纤维工程加固的应用具有一定的参考价值.

  17. 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.

  18. 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 ...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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...

  5. Focused electron beam induced deposition of magnetic nanostructures

    Science.gov (United States)

    de Teresa, Jose M.

    2011-03-01

    Nanopatterning strategies of magnetic materials normally rely on standard techniques such as electron-beam lithography using electron-sensitive resists. Focused electron beam induced deposition (FEBID) is currently being investigated as an alternative single-step route to produce functional magnetic nanostructures. Thus, Co-based and Fe-based precursors have been recently investigated for the growth of magnetic nanostructures by FEBID. In the present contribution, I will give an overview of the existing literature on magnetic nanostructures by FEBID and I will focus on the growth of Co nanostructures by FEBID using Co 2 (CO)8 as precursor gas. The Co content in the nanostructures can reach 95%. Magnetotransport experiments indicate that full metallic behaviour is displayed with relatively low residual resistivity and standard anisotropic magnetoresistance (0.8%). The coercive field of nanowires with changing aspect ratio has been determined in nanowires with width down to 150 nm by means of Magneto-optical Kerr Effect and the magnetization reversal has been imaged by means of Magnetic Force Microscopy, Scanning Transmission X-ray Microscopy as well as Lorentz Microscopy experiments. Nano-Hall probes have been grown with remarkable minimum detectable magnetic flux. Noticeably, it has been found that the domain-wall propagation field is lower than the domain-wall nucleation field in L-shaped nanowires, with potential applications in magnetic logic, sensing and storage. The spin polarization of these Co nanodeposits has been determined through Andreev-Reflection experiments in ferromagnetic-superconducting nanocontacts and amounts to 35%. Recent results obtained in Fe-based nanostructures by FEBID using Fe 2 (CO)9 precursor will be also presented. I acknowledge the collaboration in this field with A. Fernandez-Pacheco, R. Cordoba, L. Serrano, S. Sangiao, L.A. Rodriguez, C. Magen, E. Snoeck, L. Morellon, M.R. Ibarra.

  6. Coupled bending-torsion vibration of a homogeneous beam with a single delamination subjected to axial loads and static end moments

    Science.gov (United States)

    Liu, Yang; Shu, Dong-Wei

    2014-08-01

    Delaminations in structures may significantly reduce the stiffness and strength of the structures and may affect their vibration characteristics. As structural components, beams have been used for various purposes, in many of which beams are often subjected to axial loads and static end moments. In the present study, an analytical solution is developed to study the coupled bending-torsion vibration of a homogeneous beam with a single delamination subjected to axial loads and static end moments. Euler-Bernoulli beam theory and the "free mode" assumption in delamination vibration are adopted. This is the first study of the influences of static end moments upon the effects of delaminations on natural frequencies, critical buckling loads and critical moments for lateral instability. The results show that the effects of delamination on reducing natural frequencies, critical buckling load and critical moment for lateral instability are aggravated by the presence of static end moment. In turn, the effects of static end moments on vibration and instability characteristics are affected by the presence of delamination. The analytical results of this study can serve as a benchmark for finite element method and other numerical solutions.

  7. 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

  8. 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

  9. Magnetic chicane for terahertz management

    Science.gov (United States)

    Benson, Stephen; Biallas, George Herman; Douglas, David; Jordan, Kevin Carl; Neil, George R.; Michelle D. Shinn; Willams, Gwyn P.

    2010-12-28

    The introduction of a magnetic electron beam orbit chicane between the wiggler and the downstream initial bending dipole in an energy recovering Linac alleviates the effects of radiation propagated from the downstream bending dipole that tend to distort the proximate downstream mirror of the optical cavity resonator.

  10. 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.

  11. Test on Bending Performance of Recycled Concrete Composite Beams%再生混凝土叠合梁受弯力学性能试验研究

    Institute of Scientific and Technical Information of China (English)

    肖建庄; 高歌; 徐亚玲; 范氏鸾

    2012-01-01

    设计了3根再生混凝土叠合梁,受拉钢筋配筋率分别为0.5%、1.0%、1.5%,预制部分采用普通混凝土,叠合部分采用100%再生粗骨料取代率的再生混凝土.另外设计了1根整浇梁,全部采用再生粗骨料取代率的再生混凝土.通过受弯性能试验,得到挠度和裂缝发展规律以及破坏特征.运用Ansys软件对叠合梁进行了非线性有限元分析.试验结果和数值分析表明,再生混凝土叠合梁的受弯力学性能和普通混凝土梁受弯性能接近,其受弯承载力可采用普通混凝土梁的计算方法进行计算.采用再生混凝土的弹性模量,利用现有规范GB 50010-2002短期刚度计算公式得到的挠度,需乘以0.8的修正系数后才适用于再生混凝土叠合梁.%Three recycled concrete composite beams with tensile reinforcement ratios of 0. 5%, 1. 0%, 1. 5% are respectively designed. The prefabricated part uses conventional concrete while the cast-in-place part uses recycled concrete. In order to compare with the conventional concrete beam, a conventional concrete beam is also designed in which the replacement ratio of the recycled coarse aggregate is 100%. The midpoint deflections, ultimate loads, the distribution of the cracks, and failure characteristics have been obtained during the bending test. The non-linear finite element analysis is carried out by the software of Ansys. The experiment results and numerical analysis show that the recycled concrete composite beams behave similarly as the conventional concrete beams, the theory and design method applied to the conventional concrete beams can also be suitable to the recycled concrete composite beams. The deflection calculated according to the GB 50010-002 can still be applied to the recycled concrete composite beams after mordified by a factor 0. 8.

  12. 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.

  13. 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.

  14. 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...

  15. 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)

  16. Beam transport elements

    CERN Multimedia

    1965-01-01

    Two of the beam transport elements for the slow ejection system. On the left, a quadrupole 1.2 m long with a 5 cm aperture, capable of producing a gradient of 5000 gauss. On the right, a 1 m bending magnet with a 4 cm gap; its field is 20 000 gauss.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. An evaluation of the sandwich beam in four-point bending as a compressive test method for composites

    Science.gov (United States)

    Shuart, M. J.; Herakovich, C. T.

    1978-01-01

    The experimental phase of the study included compressive tests on HTS/PMR-15 graphite/polyimide, 2024-T3 aluminum alloy, and 5052 aluminum honeycomb at room temperature, and tensile tests on graphite/polyimide at room temperature, -157 C, and 316 C. Elastic properties and strength data are presented for three laminates. The room temperature elastic properties were generally found to differ in tension and compression with Young's modulus values differing by as much as twenty-six percent. The effect of temperature on modulus and strength was shown to be laminate dependent. A three-dimensional finite element analysis predicted an essentially uniform, uniaxial compressive stress state in the top flange test section of the sandwich beam. In conclusion, the sandwich beam can be used to obtain accurate, reliable Young's modulus and Poisson's ratio data for advanced composites; however, the ultimate compressive stress for some laminates may be influenced by the specimen geometry.

  2. Out-of-Plane Bending of Beam-Wall Joints Based on Elastic Medium Thick Plate Theory

    Science.gov (United States)

    Zhifei, Shi; Shuling, Yang

    2011-01-01

    The out-of-plane response of beam-wall joints is studied in the present paper. The governing equations of shear walls obtained by using the orthotropic elastic medium thick plate theory are solved. Additionally, different reinforcing ratios for shear walls in different directions are considered. It is also found that reinforced shear walls can be simplified as isotropic walls no matter whether the reinforcing ratio in both directions is the same or not for most engineering structures. In view of this, the out-of-plane response of beam-wall joints is investigated based on the isotropic medium thick plate theory and the effects of geometrical parameters of the joints on the responses of the shear walls are discussed in detail. For further simplification, the equivalent frame model is introduced and a very simple formula to determine the equivalent width is suggested for practical applications.

  3. 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

  4. 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

  5. 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...

  6. 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...

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

    CERN Multimedia

    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...

  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. 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 shear lag phenomenon, the critical LTB load is predicted within +/-15.2% of experimental data for all channel and WF specimens tested and

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

    Science.gov (United States)

    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.

  11. 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)

  12. 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

  13. Risk and Machine Protection for Stored Magnetic and Beam Energies

    CERN Document Server

    Todd, B

    2015-01-01

    Risk is a fundamental consideration when designing electronic systems. For most systems a view of risk can assist in setting design objectives, whereas both a qualitative and quantitative understanding of risk is mandatory when considering protection systems. This paper gives an overview of the risks due to stored magnetic and beam energies in high-energy physics, and shows how a risk-based approach can be used to design new systems mitigating these risks, using a lifecycle inspired by IEC 61508. Designing new systems in high-energy physics can be challenging as new and novel techniques are difficult to quantify and predict. This paper shows how the same lifecycle approach can be used in reverse to analyse existing systems, following their operation and first experiences.

  14. 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.

  15. 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)

  16. LIF Diagnostic for Measuring Beam-Transport Magnetic Fields

    Science.gov (United States)

    Jones, T. G.; Hinshelwood, D. D.; Neri, J. M.; Ottinger, P. F.; Noonan, W. A.

    1997-11-01

    A novel, spatially-resolved diagnostic is being developed to measure magnetic fields associated with intense ion beam propagation through a low-pressure gas, as is envisioned for light ion-driven ICF. The diagnostic technique uses laser-induced fluorescence (LIF) spectroscopy, and can be varied to measure either small or large fields. Small fields, as expected in ballistic transport with solenoidal lens focusing using ~ 1 Torr gas, produce Zeeman shifts, Δ λ_Z, smaller than the transition linewidth, Δ λ. High sensitivity to measure these shifts is achieved by a variation on the Babcock technique.^1 Large fields, as expected in self-pinched transport using 1--100 mTorr gas, produce Δ λZ larger than Δ λ. These Δ λZ will be resolved using an etalon as a narrowband, high-throughput optical filter. Available results from benchtop experiments using calibrated B-fields for both the small- and large-field techniques, and progress in fielding this diagnostic on the Gamble-II accelerator for beam-transport studies will be presented. Work supported by DOE through Sandia National Laboratories. ^ National Research Council Research Associate. ^ Present address University of Maryland, College Park, MD. ^1 W.A. Noonan, et al., Rev. Sci. Instrum. 68, 1032 (1997).

  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. 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.

  19. 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

  20. 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

  1. 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...

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Modeling an elastic beam with piezoelectric patches by including magnetic effects

    CERN Document Server

    Ozer, A O

    2014-01-01

    Models for piezoelectric beams using Euler-Bernoulli small displacement theory predict the dynamics of slender beams at the low frequency accurately but are insufficient for beams vibrating at high frequencies or beams with low length-to-width aspect ratios. A more thorough model that includes the effects of rotational inertia and shear strain, Mindlin-Timoshenko small displacement theory, is needed to predict the dynamics more accurately for these cases. Moreover, existing models ignore the magnetic effects since the magnetic effects are relatively small. However, it was shown recently \\cite{O-M1} that these effects can substantially change the controllability and stabilizability properties of even a single piezoelectric beam. In this paper, we use a variational approach to derive models that include magnetic effects for an elastic beam with two piezoelectric patches actuated by different voltage sources. Both Euler-Bernoulli and Mindlin-Timoshenko small displacement theories are considered. Due to the magne...

  7. Space-charge limiting currents for magnetically focused intense relativistic electron beams

    Institute of Scientific and Technical Information of China (English)

    Li Jian-Qing; Mo Yuan-Long

    2007-01-01

    The self-consistent differential equations, which describe a laminar-flow equilibrium state in a magnetically focused intense relativistic electron beam propagating inside a conducting waveguide, are presented. The canonical angular momentum, Pθ, defined under the conditions at the source, uniquely determines the possible solutions of these equations.By numerically solving these equations, the space-charge limited current and the externally applied magnetic field are obtained in a solid beam and a hollow beam in two cases of Pθ = 0 (magnetically shielded source) and Pθ = const.(immersed source) separately. It is shown that the hollow beam is more beneficial to the propagation of the intense relativistic beam through a drift tube than the solid beam.

  8. 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

  9. 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

  10. 基于C语言的结构用集成材木梁抗弯刚度模型研究%Research on Bending Stiffness C Language Model of Structural Glulam Beam

    Institute of Scientific and Technical Information of China (English)

    李杰; 申世杰; 范诒杰

    2015-01-01

    Based on parallel axis theorem,initially established bending stiffness C-language executive model of Glulam beam based on a transformed section method. Moreover,full-scale Glulam beams have been conducted bending mechanical per-formance test to verify the validity of model. Wood laminations have undergone bending test for determination of modulus of e-lasticity(MOE)based on the procedures outlined in GB/T1936.2-2009 standard. The theoretical value of bending stiffness based on C-language model of Glulam beams can be obtained by inputting the concerned parameters including MOE as men-tioned above. All the Glulam beams are instrumented on the Shimadzu universal mechanical test machine and tested to failure in four-point bending with reference to the requirements prescribed in GB/T26899-2011 standard. The mid-span deflections and applied loads are collected for computing the experimental value of bending stiffness of Glulam beams. Comparing the theoretical value based on C-language model with experimental values of Glulam beams,the relative error rate is 3.89 per-cent. When it comes to the establishment of a bending stiffness model of Glulam beams,it is of great necessity for accuracy and applicability of bending stiffness model to take account of some influencing factors such as the structural defect,mechan-ical properties variability and size effect and rationally introduce coefficient of correction.%基于平行轴定理,采用变换截面法建立结构用集成材木梁的抗弯刚度C语言可执行程序模型,并通过足尺木梁的抗弯力学性能试验验证模型的有效性。本试验根据木材抗弯弹性模量测定方法国家标准(GB/T 1936.2—2009)中的相关要求,测定层板木材的抗弯弹性模量并将其导入C语言程序模型,得到梁体抗弯刚度的模型理论值。依据结构用集成材国家标准(GB/T 26899—2011)对木梁进行四点抗弯测试并实时采集梁体跨中挠度、荷载数据,得到

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

    CERN Document Server

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

    2012-01-01

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

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. Magnetic fields and the technology challenges they pose to beam-based equipment: a semiconductor perspective

    Science.gov (United States)

    Esqueda, Vincent; Montoya, Julian A.

    2005-08-01

    As semiconductor devices shrink in size to accommodate faster processing speeds, the need for higher resolution beam-based metrology equipment and beam-based writing equipment will increase. The electron and ion beams used within these types of equipment are sensitive to very small variations in magnetic force applied to the beam. This phenomenon results from changes in Alternating Current (AC) and Direct Current (DC) magnetic flux density at the beam column which causes deflections of the beam that can impact equipment performance. Currently the most sensitive beam-based microscope manufacturers require an ambient magnetic field environment that does not have variations that exceed 0.2 milli-Gauss (mG). Studies have shown that such low levels of magnetic flux density can be extremely difficult to achieve. As examples, scissor lifts, vehicles, metal chairs, and doors moving in time and space under typical use conditions can create distortions in the Earth's magnetic field that can exceed 0.2 mG at the beam column. In addition it is known that changes in the Earth's magnetic field caused by solar flares, earthquakes, and variations in the Earth's core itself all cause changes in the magnetic field that can exceed 0.2 mG. This paper will provide the reader with the basic understanding of the emerging problem, will discuss the environmental and facility level challenges associated in meeting such stringent magnetic field environments, will discuss some of the mitigation techniques used to address the problem, and will close by discussing needs for further research in this area to assure semiconductor and nanotechnology industries are pre-positioned for even more stringent magnetic field environmental requirements.

  17. Simulation and Field Measurement of Quadrupole Magnets for KOMAC 20MeV Beam line

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. H.; Kim, H. S.; Song, Y. G.; Kwon, H. J.; Cho, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, quadrupole magnets the same as installed at the beam line simulated and analyzed for magnetic fields. Also quadrupole magnets will be measured field stability and evaluated reliability on long time operation. Control system consisted of Labview program and communication method consisted of Ethernet and Rs-232 with optical fiber for devices safety from high voltage and/or high current. As a results the DC power supply is controlled, magnetic fields data is acquired and coil temperature is measured. Magnetic field with hall sensor and temperature with K-type thermo-couple are measured with conversion factor using by voltmeter. Korea Multi-purpose Accelerator Complex (KOMAC) was developed at Gyeongju in Korea in 2012. KOMAC including a 50-keV ion source, a 3-MeV RFQ, and a 100-MeV DTL. And beam line consists of 20-MeV and 100-MeV for user. Proton beam transferred from the linac to the beam line using by dipole magnets and transferred proton beam focused and decreased beam loss and by quadrupole magnets.

  18. 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

  19. 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

  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. Study on mechanical properties of reinforced concrete beams with double holes on shear bending region%剪弯段开双孔钢筋混凝土梁受力性能的试验研究

    Institute of Scientific and Technical Information of China (English)

    李志奇; 袁广林; 邱辉

    2015-01-01

    It had focused on the mechanical properties of beams double - holes on shear - bending region under the action of concen-trated load,considering the number of holes,distance and position factors,analyzing the mechanical properties of beams double - holes on shear - bending region under the action of concentrated load.The results show that compared with RC beam with no opening,with the different number of holes,distance and position,the bearing capacity of the beams with holes and no reinforced have different de-grees of decline.When the position of the holes near the support,the beam hole,the holes spacing of less than one times the diameter of the beam and the holes spacing of more than one times the diameter of the beam bearing capacity decreased 12.7%,23.3%,16.8%.The bottom steel of beams does not yield and performance of shear compression failure state,when the position of the hole near the pure bending section,the holes spacing of less than one times the diameter of the beam bearing capacity decreased 6.6%,performance of Bending failure state.Compared with RC beam with no opening,the bearing capacity of the beams double - holes with steel reinforce-ment decreased 3.1%,the reinforcement effect is obvious,performance of bending failure state.%基于剪弯段开双孔钢筋混凝土梁受力的特点,考虑了孔洞数量、间距和位置的因素,对剪弯段开双孔梁在集中荷载作用下的受力性能进行了试验研究。研究结果表明,与未开孔钢筋混凝土梁相比,未加固开孔梁的承载力随着孔洞数量、间距和位置的变化有不同程度的降低。当孔洞位置靠近支座时,单孔梁、孔间距小于1倍孔径的双孔梁和孔间距大于1倍孔径的双孔梁的承载力分别降低了12.7%、23.3%、16.8%,破坏时梁底部钢筋均未发生屈服,呈剪压破坏状态。当孔洞位置靠近纯弯段时,孔间距小于1倍孔径的双孔梁承载力降低了6.6%,破坏时呈

  2. 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.)

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

    NARCIS (Netherlands)

    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.

    2015-01-01

    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-

  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. 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.

  6. DEPENDENCE OF DAMPING CHARACTERISTICS OF A BEAM WITH DAMPING RUBBER MAGNETIC POWDER ON RUBBER PROPERTY

    Institute of Scientific and Technical Information of China (English)

    Ming Li; Zeng He; Huiming Zheng; Ning Zhang

    2008-01-01

    A cantilever beam with Damping Material Applying Rubber Magnetic Powder (DRM)has been investigated.Two methods are selected to hold DRM to a vibrating steel beam,one is to attach DRM by the magnetic attractive force (called DRM beam) and the other by adhesive bonding (called AB-DRM beam).Different from the damping property of AB-DRM beam caused by shear deformation of damping material,the damping property of DRM beam is characterized by the sliding frictional loss together with the internal loss of damping material.The authors established a formulation to predict the damping characteristics of DRM beam,which was validated experimentally.It is found that rubber material loss factor/β has a decisive influence on damping improvement of DRM beam versus AB-DRM beam.If/β is smaller than the critical value around 0.8255,a valid range of vibratory amplitude always exists in which DRM beam can achieve better damping than AB-DRM beam;conversely,if/β is bigger than the critical value,the valid range does not exist when slide occurs.Such results are used to determine the merits and limitations of DRM and develop design guidelines.

  7. 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

  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. 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.

  10. 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

  11. 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...

  12. Performance Evaluation of Klystron Beam Focusing System with Anisotropic Ferrite Magnet

    CERN Document Server

    Fuwa, Yasuhiro

    2016-01-01

    A klystron beam focusing system using permanent magnets, which increases reliability in comparison with electromagnet focusing system, is reported. A prototype model has been designed and fabricated for a 1.3 GHz, 800 kW klystron for evaluation of the feasibility of the focusing system with permanent magnets. In order to decrease the production cost and to mitigate complex tuning processes of the magnetic field, anisotropic ferrite magnet is adopted as the magnetic material. As the result of a power test, 798 kW peak output power was successfully achieved with the prototype focusing system. Considering a power consumption of the electromagnet focusing system, the required wall-plug power to produce nominal 800 kW output power with the permanent magnet system is less than that with electromagnet. However, the power conversion efficiency of the klystron with the permanent magnet system was found to be limited by transverse multipole magnetic fields. By decreasing transverse multipole magnetic field components, ...

  13. 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.)

  14. Electron beam fabrication and characterization of high- resolution magnetic force microscopy tips

    NARCIS (Netherlands)

    Rührig, M.; Porthun, S.; Lodder, J.C.; McVitie, S.; Heyderman, L.J.; Johnston, A.B.; Chapman, J.N.

    1996-01-01

    The stray field, magnetic microstructure, and switching behavior of high‐resolution electron beam fabricated thin film tips for magnetic force microscopy (MFM) are investigated with different imaging modes in a transmission electron microscope (TEM). As the tiny smooth carbon needles covered with a

  15. Magnetic engineering of stable rod-shaped stem cell aggregates: circumventing the pitfall of self-bending.

    Science.gov (United States)

    Du, V; Fayol, D; Reffay, M; Luciani, N; Bacri, J-C; Gay, C; Wilhelm, C

    2015-02-01

    A current challenge for tissue engineering while restoring the function of diseased or damaged tissue is to customize the tissue according to the target area. Scaffold-free approaches usually yield spheroid shapes with the risk of necrosis at the center due to poor nutrient and oxygen diffusion. Here, we used magnetic forces developed at the cellular scale by miniaturized magnets to create rod-shaped aggregates of stem cells that subsequently matured into a tissue-like structure. However, during the maturation process, the tissue-rods spontaneously bent and coiled into sphere-like structures, triggered by the increasing cell-cell adhesion within the initially non-homogeneous tissue. Optimisation of the intra-tissular magnetic forces successfully hindered the transition, in order to produce stable rod-shaped stem cells aggregates. PMID:25580701

  16. 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

  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. 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.

  19. Magnet Design for the ISIS Second Target Station Proton Beam Line

    CERN Document Server

    Thomas, Chris; Jago, Stephen

    2005-01-01

    The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, is an intense source of neutrons and muons for condensed matter research. The accelerator facility delivers an 800 MeV proton beam of 2.5x1013 protons per pulse at 50 Hz to the present target station. As part of a facility upgrade, it is planned to share the source with a second, 10 Hz, target station. The beam line supplying this target will extract from the existing target station beam line. Electromagnetic Finite Element Modelling techniques have been used to design the magnets required to meet the specified beam line optics. Kicker, septum, dipole, quadrupole, and steering magnets are covered. The magnet design process, involving 2D and 3D modelling, the calculation of ideal shims and chamfers, choice of steel, design of conducting coils, handling of heating issues and eddy current effects, is discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, N. C.; Danielson, J. R.; Surko, C. M., E-mail: csurko@physics.ucsd.edu [Physics Department, University of California, 9500 Gilman Drive, San Diego, La Jolla, California 92093 (United States)

    2015-07-15

    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.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  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. 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

  8. Validation of the coupling of magnetic resonance imaging velocity measurements with computational fluid dynamics in a U bend

    NARCIS (Netherlands)

    Glor, FP; Westenberg, JJM; Vierendeels, J; Danilouchkine, M; Verdonck, P

    2002-01-01

    Magnetic resonance imaging (MRI) can be used in vivo in combination with computational fluid dynamics (CFD) to derive velocity profiles in space and time and accordingly, pressure drop and wall shear stress distribution in natural or artificial vessel segments. These hemodynamic data are difficult o

  9. 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.

  10. In Situ Characterisation of Permanent Magnetic Quadrupoles for focussing proton beams

    CERN Document Server

    Melone, J J; McCanny, T; Burris-Mog, T; Schramm, U; Grötschel, R; Akhmadaliev, S; Hanf, D; Spohr, K M; Bussmann, M; Cowan, T; Wiggins, S M; Mitchell, M R

    2011-01-01

    High intensity laser driven proton beams are at present receiving much attention. The reasons for this are many but high on the list is the potential to produce compact accelerators. However two of the limitations of this technology is that unlike conventional nuclear RF accelerators lasers produce diverging beams with an exponential energy distribution. A number of different approaches have been attempted to monochromise these beams but it has become obvious that magnetic spectrometer technology developed over many years by nuclear physicists to transport and focus proton beams could play an important role for this purpose. This paper deals with the design and characterisation of a magnetic quadrupole system which will attempt to focus and transport laser-accelerated proton beams.

  11. 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

  12. Influence of Interface Strength on Bending Properties of CFRP-Concrete Composite Beam%界面强度对CFRP-混凝土组合梁弯曲性能的影响

    Institute of Scientific and Technical Information of China (English)

    杨文龙; 张亚芳; 刘浩; 蔡北海

    2012-01-01

    CFRP(Carbon Fiber Reinforced Polymer)与混凝土之间的界面黏贴强度是影响CFRP-混凝上组合梁弯曲性能的一个重要因素.文中按CFRP布的黏结长度不同建立了3组不同界面强度的数值模型.模拟了采用位移控制梁的四点弯曲加载过程,分析了界面强度对CFRP-混凝土组合梁宏观弯曲性能的影响.结果表明:界面强度对组合梁的宏观承载力与开裂前刚度影响甚微;但对梁开裂后的刚度与延性影响较大;黏结长度越长,CFRP-混凝土组合梁对界面强度变化的敏感性越大.%The interfacial bond strength between CFRP (carbon fiber polymer) and concrete is an important factor for bending properties of CFRP-concrete composite beam. Three groups of numerical models are established based on the different bond length and interfacial strength . Four-point bending loading processes controlled by displacement are simulated. Influence of Interface Strength on Bending Properties of CFRP-concrete beam has been discussed. The results show that the interface strength has little effect on the macro-bearing capacity and the stiffness of composite beams pre-cracking, but significant effect on stiffness and ductility after cracking, and it also reflected that the longer CFRP is stuck, the more sensitive to the changes of the interfacial strength.

  13. Effect of radial plasma transport at the magnetic throat on axial ion beam formation

    Science.gov (United States)

    Zhang, Yunchao; Charles, Christine; Boswell, Rod

    2016-08-01

    Correlation between radial plasma transport and formation of an axial ion beam has been investigated in a helicon plasma reactor implemented with a convergent-divergent magnetic nozzle. The plasma discharge is sustained under a high magnetic field mode and a low magnetic field mode for which the electron energy probability function, the plasma density, the plasma potential, and the electron temperature are measured at the magnetic throat, and the two field modes show different radial parametric behaviors. Although an axial potential drop occurs in the plasma source for both field modes, an ion beam is only observed in the high field mode while not in the low field mode. The transport of energetic ions is characterized downstream of the plasma source using the delimited ion current and nonlocal ion current. A decay of ion beam strength is also observed in the diffusion chamber.

  14. Two-dimensional simulations of nonlinear beam-plasma interaction in isotropic and magnetized plasmas

    CERN Document Server

    Timofeev, I V

    2012-01-01

    Nonlinear interaction of a low density electron beam with a uniform plasma is studied using two-dimensional particle-in-cell (PIC) simulations. We focus on formation of coherent phase space structures in the case, when a wide two-dimensional wave spectrum is driven unstable, and we also study how nonlinear evolution of these structures is affected by the external magnetic field. In the case of isotropic plasma, nonlinear buildup of filamentation modes due to the combined effects of two-stream and oblique instabilities is found to exist and growth mechanisms of secondary instabilities destroying the BGK--type nonlinear wave are identified. In the weak magnetic field, the energy of beam-excited plasma waves at the nonlinear stage of beam-plasma interaction goes predominantly to the short-wavelength upper-hybrid waves propagating parallel to the magnetic field, whereas in the strong magnetic field the spectral energy is transferred to the electrostatic whistlers with oblique propagation.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Panofsky magnet for the beam extraction from the synchrotron using a fast Q-magnet and RF-knockout

    Science.gov (United States)

    Masubuchi, S.; Nakanishi, T.

    2011-12-01

    The fast control of the beam spill extracted from a synchrotron is a key function for the spot scanning irradiation in cancer therapy application. The authors propose an extraction method which uses the quadruple field of fast response, as well as the RF-knockout. A Panofsky magnet was developed as a quadruple magnet, with a frequency response of around 10 kHz. The Panofsky magnet has a rectangular beam aperture and plate coils attached to the pole face. A model magnet has been manufactured with ferrite, and static and dynamic magnetic fields were measured. From the measurement we observed that the effects of eddy current in the plate coils were large and the uniformity of the magnetic field gradient in the beam aperture was worse than ±5% with a plate thickness of 0.02 cm and a frequency of current of 10 kHz. For the future, in a detailed design the eddy current effects have to be taken into account.

  1. Panofsky magnet for the beam extraction from the synchrotron using a fast Q-magnet and RF-knockout

    Energy Technology Data Exchange (ETDEWEB)

    Masubuchi, S., E-mail: cisa09016@g.nihon-u.ac.jp [College of Industrial Technology, Nihon University, 1-2-1 Izumicho, Narashino, Chiba 275-8575 (Japan); Nakanishi, T., E-mail: nakanishi.tetsuya@nihon-u.ac.jp [College of Industrial Technology, Nihon University, 1-2-1 Izumicho, Narashino, Chiba 275-8575 (Japan)

    2011-12-15

    The fast control of the beam spill extracted from a synchrotron is a key function for the spot scanning irradiation in cancer therapy application. The authors propose an extraction method which uses the quadruple field of fast response, as well as the RF-knockout. A Panofsky magnet was developed as a quadruple magnet, with a frequency response of around 10 kHz. The Panofsky magnet has a rectangular beam aperture and plate coils attached to the pole face. A model magnet has been manufactured with ferrite, and static and dynamic magnetic fields were measured. From the measurement we observed that the effects of eddy current in the plate coils were large and the uniformity of the magnetic field gradient in the beam aperture was worse than {+-}5% with a plate thickness of 0.02 cm and a frequency of current of 10 kHz. For the future, in a detailed design the eddy current effects have to be taken into account.

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

    Energy Technology Data Exchange (ETDEWEB)

    Overweg, H. C.; Haan, A. M. J. den; Eerkens, H. J.; Bossoni, L.; Oosterkamp, T. H., E-mail: oosterkamp@physics.leidenuniv.nl [Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333CA Leiden (Netherlands); Alkemade, P. F. A. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); La Rooij, A. L.; Spreeuw, R. J. C. [Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands)

    2015-08-17

    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{sup −12} Am{sup 2}, 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.

  3. 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...

  4. 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.

  5. 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...

  6. 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

  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. 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.)

  11. 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

  12. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

    2005-06-30

    A new facility for high-pressure diffraction andspectroscopy using diamond anvil high-pressure cells has been built atthe Advanced Light Source on Beamline 12.2.2. This beamline benefits fromthe hard X-radiation generated by a 6 Tesla superconducting bendingmagnet (superbend). Useful x-ray flux is available between 5 keV and 35keV. The radiation is transferred from the superbend to the experimentalenclosure by the brightness preserving optics of the beamline. Theseoptics are comprised of: a plane parabola collimating mirror (M1),followed by a Kohzu monochromator vessel with a Si(111) crystals (E/DE ~;7000) and a W/B4C multilayers (E/DE ~; 100), and then a toroidal focusingmirror (M2) with variable focusing distance. The experimental enclosurecontains an automated beam positioning system, a set of slits, ionchambers, the sample positioning goniometry and area detectors (CCD orimage-plate detector). Future developments aim at the installation of asecond end station dedicated for in situ laser-heating on one hand and adedicated high-pressure single-crystal station, applying bothmonochromatic as well as polychromatic techniques.

  14. 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...

  15. Dual AC Dipole Excitation for the Measurement of Magnetic Multipole Strength from Beam Position Monitor Data

    Energy Technology Data Exchange (ETDEWEB)

    M. Spata, G.A. Krafft

    2011-09-01

    An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a technique for characterizing the nonlinear fields of the beam transport system. Two air-core dipole magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the electron beam. Fourier decomposition of beam position monitor data was then used to measure the amplitude of these frequencies at different positions along the beamline. For a purely linear transport system one expects to find solely the frequencies that were applied to the dipoles 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. The technique was calibrated using one of the sextupole magnets in a CEBAF beamline and then applied to a dipole to measure the sextupole and octupole strength of the magnet. A comparison is made between the beam-based measurements, results from TOSCA and data from our Magnet Measurement Facility.

  16. 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.

  17. An atomic coilgun: using pulsed magnetic fields to slow a supersonic beam

    Energy Technology Data Exchange (ETDEWEB)

    Narevicius, E [Center for Nonlinear Dynamics and Department of Physics, Univesity of Texas at Austin, Austin, TX 78712-1081 (United States); Parthey, C G [Center for Nonlinear Dynamics and Department of Physics, Univesity of Texas at Austin, Austin, TX 78712-1081 (United States); Libson, A [Center for Nonlinear Dynamics and Department of Physics, Univesity of Texas at Austin, Austin, TX 78712-1081 (United States); Narevicius, J [Center for Nonlinear Dynamics and Department of Physics, Univesity of Texas at Austin, Austin, TX 78712-1081 (United States); Chavez, I [Center for Nonlinear Dynamics and Department of Physics, Univesity of Texas at Austin, Austin, TX 78712-1081 (United States); Even, U [Sackler School of Chemistry, Tel-Aviv University, Tel-Aviv (Israel); Raizen, M G [Center for Nonlinear Dynamics and Department of Physics, Univesity of Texas at Austin, Austin, TX 78712-1081 (United States)

    2007-10-15

    We report the experimental demonstration of a novel method to slow atoms and molecules with permanent magnetic moments using pulsed magnetic fields. In our experiments, we observe the slowing of a supersonic beam of metastable neon from 461.0 {+-} 7.7 to 403 {+-} 16 m s{sup -1} in 18 stages, where the slowed peak is clearly separated from the initial distribution. This method has broad applications as it may easily be generalized, using seeding and entrainment into supersonic beams, to all paramagnetic atoms and molecules.

  18. Practical assessment of magnetic methods for corrosion detection in an adjacent precast, prestressed concrete box-beam bridge

    Science.gov (United States)

    Fernandes, Bertrand; Titus, Michael; Nims, Douglas Karl; Ghorbanpoor, Al; Devabhaktuni, Vijay Kumar

    2013-06-01

    Magnetic methods are progressing in the detection of corrosion in prestressing strands in adjacent precast, prestressed concrete box-beam bridges. This study is the first field trial of magnetic strand defect detection systems on an adjacent box-beam bridge. A bridge in Fayette County, Ohio, which was scheduled for demolition, was inspected. Damage to prestressed box-beams is often due to corrosion of the prestressing strands. The corroded strands show discontinuities and a reduced cross-sectional area. These changes, due to corrosion, are reflected in the magnetic signatures of the prestressing steel. Corrosion in the prestressing steel was detected using two magnetic methods, namely the 'magnetic flux leakage' (MFL) and the 'induced magnetic field'. The purpose of these tests was to demonstrate the ability of the magnetic methods to detect hidden corrosion in box-beams in the field and tackle the logistic problem of inspecting box-beams from the bottom. The inspections were validated by dissecting the bottom of the box-beams after the inspections. The results showed that the MFL method can detect hidden corrosion and strand breaks. Both magnetic field methods were also able to estimate corrosion by detecting the effective cross-sectional area of the strand in sections of the beams. Thus, it was shown that the magnetic methods can be used to predict hidden corrosion in prestressing strands of box-beams.

  19. 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...

  20. 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.

  1. Review of magnetic nanostructures grown by focused electron beam induced deposition (FEBID)

    Science.gov (United States)

    De Teresa, J. M.; Fernández-Pacheco, A.; Córdoba, R.; Serrano-Ramón, L.; Sangiao, S.; Ibarra, M. R.

    2016-06-01

    We review the current status of the use of focused electron beam induced deposition (FEBID) for the growth of magnetic nanostructures. This technique relies on the local dissociation of a precursor gas by means of an electron beam. The most promising results have been obtained using the Co2(CO)8 precursor, where the Co content in the grown nanodeposited material can be tailored up to more than 95 at.%. Functional behaviour of these Co nanodeposits has been observed in applications such as arrays of magnetic dots for information storage and catalytic growth, magnetic tips for scanning probe microscopes, nano-Hall sensors for bead detection, nano-actuated magnetomechanical systems and nanowires for domain-wall manipulation. The review also covers interesting results observed in Fe-based and alloyed nanodeposits. Advantages and disadvantages of FEBID for the growth of magnetic nanostructures are discussed in the article as well as possible future directions in this field.

  2. Improvement of neutral beam injection heating efficiency with magnetic field well structures in a tokamak with a low magnetic field

    Science.gov (United States)

    Kim, S. K.; Na, D. H.; Lee, J. W.; Yoo, M. G.; Kim, H.-S.; Hwang, Y. S.; Hahm, T. S.; Na, Yong-Su

    2016-10-01

    Magnetic well structures are introduced as an effective means to reduce the prompt loss of fast ions, the so-called first orbit loss from neutral beam injection (NBI), which is beneficial to tokamaks with a low magnetic field strength such as small spherical torus devices. It is found by single-particle analysis that this additional field structure can modify the gradient of the magnetic field to reduce the shift of the guiding center trajectory of the fast ion. This result is verified by a numerical calculation of following the fast ion’s trajectory. We apply this concept to the Versatile Experiment Spherical Torus [1], where NBI is under design for the purpose of achieving high-performance plasma, to evaluate the effect of the magnetic well structure on NBI efficiency. A 1D NBI analysis code and the NUBEAM code are employed for detailed NBI calculations. The simulation results show that the orbit loss can be reduced by 70%-80%, thereby improving the beam efficiency twofold compared with the reference case without the well structure. The well-shaped magnetic field structure in the low-field side can significantly decrease orbit loss by broadening the non-orbit loss region and widening the range of the velocity direction, thus improving the heating efficiency. It is found that this magnetic well can also improve orbit loss during the slowing down process.

  3. 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...

  4. 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

  5. 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

  6. Magnetically scanned proton therapy beams: rationales and principles

    Science.gov (United States)

    Jones, D. T. L.; Schreuder, A. N.

    2001-06-01

    High-energy proton therapy is finding increased application in radiation oncology because of the unique physical characteristics of proton beams which allow superior conformation of the high-dose region to the target volume. The standard method of "painting" the required dose over the target volume is to use passive mechanical means involving multiple scattering and variable thickness absorbers. However, this technique dose not allow proximal surface dose conformation which can only be achieved using beam scanning techniques. Apart from reducing the integral dose, intensity modulation and inverse planning are possible, there is less activation of the surroundings and no field-specific modification devices are required. However, scanning systems are very complicated and there are very high instantaneous dose rates which require sophisticated control systems.

  7. Creation of Magnetized Jet Using a Ring of Laser Beams

    CERN Document Server

    Fu, Wen; Tzeferacos, Petros; Lamb, Donald Q

    2014-01-01

    We propose a new way of generating magnetized supersonic jets using a ring laser to irradiate a flat surface target. Using 2D FLASH code simulations which include the Biermann Battery term, we demonstrate that strong toroidal fields can be generated and sustained downstream in the collimated jet outflow far from the target surface. The field strength can be controlled by varying the ring laser separation, thereby providing a versatile laboratory platform for studying the effects of magnetic field in a variety of astrophysical settings.

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

    Science.gov (United States)

    Koseki, K.; Nakayama, H.; Tawada, M.

    2014-04-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Koseki, K., E-mail: kunio.koseki@kek.jp; Nakayama, H.; Tawada, M. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2014-04-15

    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{sup −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{sup −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{sup −4}, which is an acceptable value, was achieved.

  10. Detecting magnetic field direction by a micro beam operating in different vibration modes

    Institute of Scientific and Technical Information of China (English)

    Chen Jie; Qin Ming; Huang Qing-An

    2011-01-01

    A new method to detect the magnetic field direction by using a silicon structure is presented in this paper. The structure includes a micro beam and an in-plane coil electrode. When the electrode under a magnetic field is applied with an alternating current,the micro beam is actuated under the effect of the Lorentz forces. Magnetic fields of different directions cause different vibration profiles. The direction of the magnetic field is obtained by measuring the vibration amplitudes of the micro beam,which is driven to work at first- and second-order resonant modes. A micro structure has been fabricated using the bulk micromachined silicon process. A laser Doppler vibrometer system is implemented to measure the vibration amplitudes. The experimental results show that the amplitude of the structure,which depends on the different modes,is a sine or cosine function of the angle of the magnetic field. It agrees well with the simulation result. Currently a resolution of 100 for the magnetic field direction measurement can be obtained using the detecting principle.

  11. 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.

  12. 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.

  13. Rock bending creep and disturbance effects

    Institute of Scientific and Technical Information of China (English)

    付志亮; 郑颖人; 刘元雪

    2008-01-01

    The bending creep and its disturbance effects of red sandstone rock beam and oil shale rock beam were studied by adopting the self-developed gravitation level style rock creep test machine and bending creep test system,and the constitutive equations were established.It is found that fracture morphology of rock beams under no disturbance load is regular,cracking position of fractures is on part of loading concentration,the crack starts from a neutral plane.However,fracture morphology of rock beams under disturbance load is irregular,cracking position of fractures deviates from a neutral plane.Delayed instability of rock beam occurs for some time under constant disturbance load.When disturbance load is beyond a certain range,suddenly instability of occurs rock beam in a certain time.The results show that there is a guiding significance for creep stability in the geotechnical engineering fields.

  14. Imaging the attenuation coefficients of magnetically constrained positron beams in matter

    Science.gov (United States)

    Watson, Charles C.

    2016-09-01

    This paper describes a method for tomographically imaging the linear attenuation coefficients (LACs) of positron beams in heterogeneous materials. A β+ ray emitter such as 68Ga, placed in a uniform 3T static magnetic field, generates a well-defined positron beam that maintains its spatial coherence over an attenuation of more than 10-3 while signaling its intensity via the annihilation radiation it generates. A positron emission tomography (PET) system embedded in the magnetic field measures the positron-electron annihilation distribution within objects illuminated by the beam. It's shown that this image can be decomposed into maps of the positron beam's flux and its material-dependent LACs without need for auxiliary measurements or transmission of the beam completely through the object. The initial implementation employs a hybrid PET/magnetic resonance imaging (MRI) scanner developed for medical applications. Mass thicknesses up to 0.55 g/cm2 at a spatial resolution of a few millimeters have been imaged.

  15. 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

  16. Improvements of the magnetic field design for SPIDER and MITICA negative ion beam sources

    Energy Technology Data Exchange (ETDEWEB)

    Chitarin, G., E-mail: chitarin@igi.cnr.it [Consorzio RFX, C.so Stati Uniti 4, 35129 Padova (Italy); University of Padova, Dept. of Management and Engineering, Strad. S. Nicola 3, 36100 Vicenza (Italy); Agostinetti, P.; Aprile, D.; Marconato, N.; Veltri, P. [Consorzio RFX, C.so Stati Uniti 4, 35129 Padova (Italy)

    2015-04-08

    The design of the magnetic field configuration in the SPIDER and MITICA negative ion beam sources has evolved considerably during the past four years. This evolution was driven by three factors: 1) the experimental results of the large RF-driven ion sources at IPP, which have provided valuable indications on the optimal magnetic configurations for reliable RF plasma source operation and for large negative ion current extraction, 2) the comprehensive beam optics and heat load simulations, which showed that the magnetic field configuration in the accelerator is crucial for keeping the heat load due to electrons on the accelerator grids within tolerable limits, without compromising the optics of the negative ion beam in the foreseen operating scenarios, 3) the progress of the detailed mechanical design of the accelerator, which stimulated the evaluation of different solutions for the correction of beamlet deflections of various origin and for beamlet aiming. On this basis, new requirements and solution concepts for the magnetic field configuration in the SPIDER and MITICA beam sources have been progressively introduced and updated until the design converged. The paper presents how these concepts have been integrated into a final design solution based on a horizontal “long-range” field (few mT) in combination with a “local” vertical field of some tens of mT on the acceleration grids.

  17. 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

  18. 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.

  19. 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.

  20. 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%

  1. 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.

  2. 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.

  3. 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

  4. Fabrication of surface magnetic nanoclusters using low energy ion implantation and electron beam annealing

    Science.gov (United States)

    Kennedy, J.; Leveneur, J.; Williams, G. V. M.; Mitchell, D. R. G.; Markwitz, A.

    2011-03-01

    Magnetic nanoclusters have novel applications as magnetic sensors, spintronic and biomedical devices, as well as applications in more traditional materials such as high-density magnetic storage media and high performance permanent magnets. We describe a new synthesis protocol which combines the advantages of ion implantation and electron beam annealing (EBA) to produce surface iron nanoclusters. We compare the structure, composition and magnetic properties of iron nanoclusters fabricated by low dose 15 keV Fe implantation into SiO2 followed by 1000 °C EBA or furnace annealing. Atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM) images together with superconducting quantum interference device (SQUID) magnetometry measurements show that only EBA leads to the rapid formation of surface crystalline Fe spherical nanoclusters, showing magnetic moments per Fe atom comparable to that of bulk bcc Fe and superparamagnetic properties. We propose a fabrication mechanism which includes e-beam enhanced desorption of SiO2. This method has potential for fabricating nanoscale magnetic sensors integrated in microelectronic devices.

  5. Electron Beam Dose Distribution in the Presence of Non-Uniform Magnetic Field

    Directory of Open Access Journals (Sweden)

    Mohamad Javad Tahmasebi-Birgani

    2014-04-01

    Full Text Available Introduction Magnetic fields are capable of altering the trajectory of electron beams andcan be used in radiation therapy.Theaim of this study was to produce regions with dose enhancement and reduction in the medium. Materials and Methods The NdFeB permanent magnets were arranged on the electron applicator in several configurations. Then, after the passage of the electron beams (9 and 15 MeV Varian 2100C/D through the non-uniform magnetic field, the Percentage Depth Dose(PDDs on central axis and dose profiles in three depths for each energy were measured in a 3D water phantom. Results For all magnet arrangements and for two different energies, the surface dose increment and shift in depth of maximum dose (dmax were observed. In addition, the pattern of dose distribution in buildup region was changed. Measurement of dose profile showed dose localization and spreading in some other regions. Conclusion The results of this study confirms that using magnetic field can alter the dose deposition patterns and as a result can produce dose enhancement as well as dose reduction in the medium using high-energy electron beams. These effects provide dose distribution with arbitrary shapes for use in radiation therapy.

  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. 剪切对泡沫夹层结构梁弯曲性能的影响%THE INFLUENCE OF SHEAR ON THE BENDING PROPERTIES OF FOAM CORE SANDWICH BEAMS

    Institute of Scientific and Technical Information of China (English)

    李真; 周仕刚; 薛元德

    2011-01-01

    In this study, based on the assumption that the cross section is plane, but no longer vertical to the axis of the foam core sandwich beam, an analysis method on the bending properties is established by means of the energy principle. Comparing experimental data and the results of finite element method, it is showed that the deflection of foam core sandwich beam by these methods could be accurately predicted. Based on the numerical examples,the influence of shear on the deflection of foam core sandwich beam is discussed, and the deflection caused by shear force decreases with the increase of span-height ratio of the beam. It also discussed the distribution of the normal strain and normal stress of the cross-section of the beam.%本文以受剪后横截面仍为一平面但与轴线不再垂直为基本假设,采用能量法建立了一种对泡沫夹层结构梁的弯曲性能进行分析的方法.通过对比试验数据以及有限元的计算结果,得到用该方法可较为准确地预测泡沫夹层结构梁的挠度.通过分析,得到了剪切对泡沫夹层结构梁挠度的影响程度随着梁的跨高比的增大而减小,同时讨论了梁横截面正应变及正应力的分布情况.

  8. 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.

  9. Beam Halo on the LHC TCDQ Diluter System and Thermal Load on the Downstream Superconducting Magnets

    CERN Document Server

    Goddard, B; Presland, A; Redaelli, S; Robert-Démolaize, G; Sarchiapone, L; Weiler, T; Weterings, W

    2006-01-01

    The moveable single-jawed graphite TCDQ diluter must be positioned very close to the circulating LHC beam in order to prevent damage to downstream components in the event of an unsynchronised beam abort. A two-jawed graphite TCS.IR6 collimator forms part of the TCDQ system. The requirement to place the jaws close to the beam means that the system can intercept a substantial beam halo load. Initial investigations indicated a worryingly high heat load on the Q4 coils. This paper presents the updated load cases, shielding and simulation geometry, and the results of simulations of the energy deposition in the TCDQ system and in the downstream superconducting Q4 magnet. The implications for the operation of the LHC are discussed.

  10. 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.

  11. 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.

  12. 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

  13. 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)

  14. Development of a hybrid dome composed of glued-laminated timbers and steel cables. (Part 4). ; Bending and buckling tests on compled glulam beams. Daidanmen shuseizai to cable ni yoru hybridter dot dome kozo no kaihatsu. 4. ; Kumitate shuseizai buzai no mage jikken oyobi zakutsu jikken

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, H.; Tsubota, H.; Maruyama, N.; Sasaki, N. (Kajima Corp., Tokyo (Japan))

    1991-10-31

    As a part of the development of the large scale hybrid dome (140 m in diameter, 49 m in height) composed of glued-laminated timbers (glulam) and steel cables, bending and buckling tests were conducted on coupled glulam beams. As the result of bending tests, every specimen offered a sufficient bending capacity for the allowable stress calculated by AIJ (Architectural Institute of Japan) standard, and no bending stiffness of a strong axis specimen decreased in the absence of adhesive, while that of a weak one was greatly affected by how firmly main beams and spacer blocks were attached to each other. As the result of buckling tests, the effect of joints on buckling strength was negligible, and the buckling strength of beams was high enough to guarantee the safety of the dome. The buckling strength could be accurately estimated from the slenderness ratio of the main beam as adhesion assured nearly perfect attachment, and the effective slenderness ratios of beams without adhesive well corresponded to those calculated by AIJ standard. 2 refs., 9 figs., 5 tabs.

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

    CERN Document Server

    Iadarola, Giovanni; Rumolo, Giovanni

    2016-01-01

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

  16. Ion beam driven resonant ion-cyclotron instability in a magnetized dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Ved; Vijayshri [School of Sciences, Indira Gandhi National Open University, Maidan Garhi, New Delhi 110 068 (India); Sharma, Suresh C. [Department of Applied Physics, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi 110 042 (India); Gupta, Ruby [Department of Physics, Swami Shraddhanand College, University of Delhi, Alipur, Delhi 110 036 (India)

    2014-03-15

    Electrostatic ion cyclotron waves are excited by axial ion beam in a dusty plasma via Cerenkov and slow cyclotron interaction. The dispersion relation of the instability is derived in the presence of positively/negatively charged dust grains. The minimum beam velocity needed for the excitation is estimated for different values of relative density of negatively charged dust grains. It is shown that the minimum beam velocity needed for excitation increases as the charge density carried by dust increases. Temperature of electrons and ions, charge and mass of dust grains, external static magnetic field and finite boundary of dusty plasma significantly modify the dispersion properties of these waves and play a crucial role in the growth of resonant ion cyclotron instability. The ion cyclotron modes with phase velocity comparable to the beam velocity possess a large growth rate. The maximum value of growth rate increases with the beam density and scales as the one-third power of the beam density in Cerenkov interaction and is proportional to the square root of beam density in slow cyclotron interaction.

  17. 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.

  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. Active Vibration Control of Beam Using Electro-magnetic Constrained Layer Damping

    Institute of Scientific and Technical Information of China (English)

    Niu Hongpan; Zhang Yahong; Zhang Xinong; Xie Shilin

    2008-01-01

    This paper investigates vibration control of beam through electro-magnetic constrained layer damping (EMCLD) which consists of electromagnet layer, permanent magnet layer and viscoelastic damping layer. When the coil of the electromagnet is electrified with proper control strategy, the electromagnet can exert magnetic force opposite to the direction of structural deformation so that the struc- tural vibration is attenuated. A mathematical model is developed based on the equivalent current method to calculate the electromagnetic control force produced by EMCLD. The governing equations of the system are obtained using Hamilton's Principle and then reduced with the assumed-mode method. A simulation on vibration control of a cantilever beam is conducted under the velocity proportional feedback to demonstrate the energy dissipation capability of EMCLD, and the beam system with the same parameter is experimented. The results of experiment and simulation are compared and the results show that the EMCLD is an effective means for suppressing modal vibration. The results also indicate that the beam system has better control performance for larger control current. The EMCLD method presented in this paper provides an applicable and efficient tool for the vibration control of structures.

  20. Resonant principle for operation of energy recuperator for a magnetized electron beam: A numerical simulation

    Science.gov (United States)

    Arzhannikov, A. V.; Astrelin, V. T.; Koidan, V. S.; Sinitsky, S. L.

    2002-04-01

    The problem of energy recuperator for a high current sheet electron beam used to drive a millimeter-waves generator is considered. There are two main obstacles to solving the problem. The first one is the presence of a magnetic field guiding beam electrons. The second obstacle is significant energy and angular spreads of the electrons in the waste beam. To overcome these obstacles, we suggest a novel scheme of a recuperator. The main idea of the proposed scheme is the use of a decelerating electrical field together with a guiding magnetic field that has longitudinal and spatial periodic transverse components. Resonance of a bounce electron motion with the cyclotron motion in this field gives a strong increase in the Larmour radius of electrons with the energy in a narrow interval. The decelerated electrons with the resonance energy fall away from the beam and are absorbed by a collector at a proper potential. It is shown that efficiency of this novel scheme can reach about 80% even if the sheet beam has a broad energy spectrum.

  1. 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.)

  2. 钢筋混凝土梁受弯破坏机理尺寸效应试验研究%Experimental Study on Size Effect of Bending Failure Mechanism of RC Beams

    Institute of Scientific and Technical Information of China (English)

    周宏宇; 李振宝; 杜修力; 郭二伟

    2012-01-01

    针对尺寸效应特性对梁构件受弯破坏的影响机理,对不同截面尺寸简支梁相似试件开展单调加载试验,测试构件在不同加载阶段的承载力、挠度和截面应变等试验数据.按不同加载阶段分析其力学性能的影响因素,并阐述其破坏机理的尺寸效应.试验分析表明,混凝土材料抗压特性在受弯构件力学性能中表现为负面尺寸效应,这种负面尺寸效应对构件整体力学行为的影响并不显著.相比之下,内力臂和钢筋等因素对试件承载力和延性均产生显著的正面影响.随截面尺寸增大,受弯承载力和延性均呈增长趋势.根据试件在不同尺度上表现出的显著破坏特征和实测数据,推导相关计算参数随试件尺寸的关系,建立考虑尺寸效应的极限承载力计算方程.同时也验证了现有极限承载力计算理论的安全性.%Size effect is concrete inherent characteristic and has an effect on beam bending failure mechanism. Bending experiments based on different section size RC free beams were carried out and test data was collected in different loading stage, including bearing capacity, deflection, section strain etc. Size effect factors and failure mechanism were analyzed according to different loading stage. Concrete compressive properties show negative size effect in bending member mechanical properties, but it is not significant in overall mechanical behaviors. Internal force arm and longitudinal reinforcement have positive effect to flexural bearing capacity and ductility. Flexural bearing capacity and ductility show a growing trend with member size increasing. Failure characteristics and measured data show significant difference in specimen size. Related calculation parameters which have a relationship with section height are derived, and then ultimate bearing capacity calculation equations with size effect related are established. Bearing capacity calculation theories in current specifications

  3. 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)

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  8. 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.

  9. 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

  10. H-mode accelerating structures with permanent-magnet quadrupole beam focusing

    Science.gov (United States)

    Kurennoy, S. S.; Rybarcyk, L. J.; O'Hara, J. F.; Olivas, E. R.; Wangler, T. P.

    2012-09-01

    We have developed high-efficiency normal-conducting rf accelerating structures by combining H-mode resonator cavities and a transverse beam focusing by permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of interdigital H-mode (IH-PMQ) structures is 10-20 times higher than that of a conventional drift-tube linac, while the transverse size is 4-5 times smaller. Results of the combined 3D modeling—electromagnetic computations, multiparticle beam-dynamics simulations with high currents, and thermal-stress analysis—for an IH-PMQ accelerator tank are presented. The accelerating-field profile in the tank is tuned to provide the best propagation of a 50-mA deuteron beam using coupled iterations of electromagnetic and beam-dynamics modeling. Measurements of a cold model of the IH-PMQ tank show a good agreement with the calculations. Examples of cross-bar H-mode structures with PMQ focusing for higher beam velocities are also presented. H-PMQ accelerating structures following a short radio-frequency quadrupole accelerator can be used both in the front end of ion linacs or in stand-alone applications.

  11. 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)

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.)

  18. Ultimate negative bending-moment capacity of outer-plated steel-concrete continuous composite beams%外包钢-混凝土连续组合梁的负弯矩极限承载力

    Institute of Scientific and Technical Information of China (English)

    陈丽华; 李爱群; 娄宇; 李培彬

    2009-01-01

    Static load tests and bearing capacity analyses are cardeA out for two outer-plated steel-concrete continuous composite beams.The load-deflection curve and the loat-strain culve of specimens are obtained and analyzed.The test results indicate that effective cooperation can be achieved by the shear-resistant connection between the reinforcement in the negative moment area and the outer-plated steel beam,and the overall working performance of the composite beams is favorable.At the load-bearing limiting state,the plastic strain on the maximum negative and positive moment section becomes fully developed so as to form relatively ideal plastic hinges.With the increase in the reinforcement ratio,the moment-carrying capacity of the composite beams improves significantly,but the ductility of the beams and the rotation ability of the plastic hinges decrease.The formulae for calculating the limit bending capacity in the negative moment area of outer-plated steel-concrete composite beams are proposed based on the test data.The calculated results agree well with the test results.%对2根外包钢-混凝土连续梁试件进行了静力加载实验研究与承栽力分析.测量并分析了试件的荷栽-挠度及荷载-应变关系曲线.结果表明:外包钢-混凝土组合梁负弯矩区钢筋和外包钢梁通过抗剪连接措施能有效地共同工作,整体工作性能良好.在承栽能力极限状态,负弯矩和正弯矩最大截面的塑性应变均充分发展,并形成比较理想的塑性铰.随着配筋率的提高,组合梁受弯承栽力明显提高,而延性和转动能力相应降低.在试验数据基础上,给出了外包钢-混凝土组合梁在负弯矩区极限受弯承载力的计算公式,计算结果与实验结果吻合良好.

  19. 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.

  20. 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.

  1. Magnetic fields and beam optics studies of a 250 MeV superconducting proton radiotherapy cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Won [Research Institute and Hospital, National Cancer Center, 809 Madu-dong, Koyang, Kyonggi (Korea, Republic of)], E-mail: jwkim@ncc.re.kr

    2007-11-21

    A 250 MeV superconducting cyclotron for the proton radiation therapy was designed at the Michigan State University (MSU) for use at the Paul Scherrer Institut. This work was based on the conceptual design carried out at the MSU in 1994. The previous design was refined to finalize the magnet configuration and to optimally arrange cyclotron elements for the actual construction. The spiral angle of the pole was reduced, the new hill-edges and valley shims being introduced. The magnetic fields were highly isochronized using a least square fitting routine involving a schematic shimming scheme. The resulting reference field was adequate for the elaborate study of beam optics. The optics simulation predicted that extraction efficiency of above 80% was achievable for a beam with the initial phase width of 20{sup o}. The vertical deflector was investigated located in the central region to control the beam intensity with tracking of beam phase spaces. Some measurement results for the constructed cyclotron were found in a good agreement with those of the optics study.

  2. 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

  3. 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

  4. 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.

  5. Design of a multi-bend achromat lattice for 3 GeV synchrotron light source

    Science.gov (United States)

    Kim, Eun-San

    2016-03-01

    We present a lattice design for a low-emittance and high-brilliance 3 GeV synchrotron light source that has been widely investigated in the world. We show the design results for a MBA (Multi-Bend Achromat) lattice with an emittance of 1.3 nm and 282.4 m circumference. Each cell has 5 bending magnets that consist of outer two with bending angle of 4.5° and inner three with bending angle of 7°. The lattice is designed to be flexible and consists of 12 straight sections in which one straight section has a length of 5.9 m. We have studied the dynamic aperture in the lattice with machine errors. It is shown that the designed low-emittance lattice provides sufficient dynamic aperture after COD correction. We present the results of variations of emittance, energy spread and dynamic aperture due to in-vacuum undulators in the straight sections. We performed particle tracking after the beam injection to investigate the efficiency of the injection scheme. We show the designed results of an injection scheme that shows the space allocation in injection section and the particle motions of injected beam. Our designed lattice provides a good optimization in terms of the emittance and brilliance as a light source for 3 GeV energy and circumference of 28 m.

  6. 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

  7. An adjustable focusing system for a 2 MeV H- ion beam line based on permanent magnet quadrupoles

    CERN Document Server

    Nirkko, M; Ereditato, A; Kreslo, I; Scampoli, P; Weber, M

    2012-01-01

    A compact adjustable focusing system for a 2 MeV H- RFQ Linac is designed, constructed and tested based on four permanent magnet quadrupoles (PMQ). A PMQ model is realised using finite element simulations, providing an integrated field gradient of 2.35 T with a maximal field gradient of 57 T/m. A prototype is constructed and the magnetic field is measured, demonstrating good agreement with the simulation. Particle track simulations provide initial values for the quadrupole positions. Accordingly, four PMQs are constructed and assembled on the beam line, their positions are then tuned to obtain a minimal beam spot size of (1.2 x 2.2) mm^2 on target. This paper describes an adjustable PMQ beam line for an external ion beam. The novel compact design based on commercially available NdFeB magnets allows high flexibility for ion beam applications.

  8. 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.

  9. 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

  10. 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...

  11. 合拢弯矩作用下复合材料曲梁突变屈曲的研究%Delamination Buckling of a Curved Composite Beam Subjected to a Closing Bending Moment

    Institute of Scientific and Technical Information of China (English)

    王玮波; R.; A.; SHENOI; 崔维成

    2006-01-01

    The snap buckling case in a curved composite beam under a closing bending moment is dealt with.A theoretical approach is developed for the non-linear problem of delamination buckling which is likely to occur in curved composite structures.The approach is based on large deflection characterisation of a curved beam,coupled with fracture mechanics concepts.The general solution is applied to analyse a special case in which delamination occurs very close to inner surface of the beam and snap buckling happens in this delaminated thin layer. The effect of the arc angle of delamination crack on the critical load is also studied.%研究了复合材料曲梁在受到合拢弯矩作用下发生的屈曲情况,并给出一种理论解析方法来分析这种很可能发生在复合材料弯曲结构中的脱层耦合屈曲问题.该方法是基于曲梁大变形理论及断裂力学而提出来的.文中并用该解析方法分析了一个特定的常见的情况,在该题例中脱层发生在非常靠近内表面处并且突变屈曲就发生在该薄脱层.在文中也对脱层裂纹的弧角对极限载荷的影响进行了研究.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. Bend me, shape me

    CERN Multimedia

    2002-01-01

    A Japanese team has found a way to bend and shape silicon substrates by growing a thin layer of diamond on top. The technique has been proposed as an alternative to mechanical bending, which is currently used to make reflective lenses for X-ray systems and particle physics systems (2 paragraphs).

  17. 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.

  18. 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.

  19. Envelope model for passive magnetic focusing of an intense proton or ion beam propagating through thin foils

    Science.gov (United States)

    Lund, Steven M.; Cohen, Ronald H.; Ni, Pavel A.

    2013-04-01

    Ion beams (including protons) with low emittance and high space-charge intensity can be propagated with normal incidence through a sequence of thin metallic foils separated by vacuum gaps of order the characteristic transverse beam extent to transport/collimate the beam or to focus it to a small transverse spot. Energetic ions have sufficient range to pass through a significant number of thin foils with little energy loss or scattering. The foils reduce the (defocusing) radial electric self-field of the beam while not altering the (focusing) azimuthal magnetic self-field of the beam, thereby allowing passive self-beam focusing if the magnetic field is sufficiently strong relative to the residual electric field. Here we present an envelope model developed to predict the strength of this passive (beam generated) focusing effect under a number of simplifying assumptions including relatively long pulse duration. The envelope model provides a simple criterion for the necessary foil spacing for net focusing and clearly illustrates system focusing properties for either beam collimation (such as injecting a laser-produced proton beam into an accelerator) or for magnetic pinch focusing to a small transverse spot (for beam driven heating of materials). An illustrative example is worked for an idealization of a recently performed laser-produced proton-beam experiment to provide guidance on possible beam focusing and collimation systems. It is found that foils spaced on the order of the characteristic transverse beam size desired can be employed and that envelope divergence of the initial beam entering the foil lens must be suppressed to limit the total number of foils required to practical values for pinch focusing. Relatively modest proton-beam current at 10 MeV kinetic energy can clearly demonstrate strong magnetic pinch focusing achieving a transverse rms extent similar to the foil spacing (20-50μm gaps) in beam propagation distances of tens of mm. This is a surprisingly

  20. 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.

  1. 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)

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. Fe:O:C grown by focused-electron-beam-induced deposition: magnetic and electric properties

    Energy Technology Data Exchange (ETDEWEB)

    Lavrijsen, R; Schoenaker, F J; Ellis, T H; Barcones, B; Kohlhepp, J T; Swagten, H J M; Koopmans, B [Department of Applied Physics, Center for NanoMaterials and COBRA Research Institute, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Cordoba, R; Ibarra, M R [Instituto de Nanociencia de Aragon, Universidad de Zaragoza, E-50009 Zaragoza (Spain); De Teresa, J M; Magen, C [Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Trompenaars, P; Mulders, J J L, E-mail: r.lavrijsen@tue.nl, E-mail: deteresa@unizar.es [FEI Electron Optics, Achtseweg Noord 5, 5651 GG Eindhoven (Netherlands)

    2011-01-14

    We systematically study the effect of oxygen content on the magneto-transport and microstructure of Fe:O:C nanowires deposited by focused-electron-beam-induced (FEBID) deposition. The Fe/O ratio can be varied with an Fe content varying between {approx} 50 and 80 at.% with overall low C content ({approx}16 {+-} 3 at.%) by adding H{sub 2}O during the deposition while keeping the beam parameters constant as measured by energy dispersive x-ray (EDX) spectroscopy. The room-temperature magnetic properties for deposits with an Fe content of 66-71 at.% are investigated using the magneto-optical Kerr effect (MOKE) and electric magneto-transport measurements. The nanostructure of the deposits is investigated through cross-sectional high-resolution transmission electron microscopy (HRTEM) imaging, allowing us to link the observed magneto-resistance and resistivity to the transport mechanism in the deposits. These results demonstrate that functional magnetic nanostructures can be created, paving the way for new magnetic or even spintronics devices.

  7. 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

  8. 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.)

  9. 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

  10. 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

  11. 钢-混凝土组合梁弯筋连接件的抗剪承载力%Shear capacity research on bend bar connectors of steel-concrete composite beams

    Institute of Scientific and Technical Information of China (English)

    张中育; 李青宁; 姜维山

    2013-01-01

    This article mainly does the research on bend bar shear connector of steel-concrete composite beams and compares the shear capacity calculation formulas of different standards in many countries,besides,this paper also analysis the characteristic and structure of serpents bern connectors which is used in practical engineering recent years.Based on these,the shear capacity calculation formulas are proposed which can provide references for engineering design.%针对钢-混凝土组合梁抗剪连接件中的弯筋连接件开展研究,比较了目前各国规范中的弯筋连接件形式及其抗剪承载力计算公式.分析了近年才开始用于实际工程中的蛇形弯筋连接件的特点及构造,并在此基础上提出蛇形弯筋连接件的抗剪承载力计算公式,以供工程设计参考.

  12. Excitation of Electromagnetic Waves by an Electron Ring Beam in a Magnetized Plasma Waveguide

    Institute of Scientific and Technical Information of China (English)

    周国成; 吴京生; 王德驹; 陈雁萍

    2002-01-01

    We study the resonant interactions between an electron ring beam and plasma waveguide modes. This is motivatedby the research of radio emission in low solar corona. We consider a density-depleted duct (above an active regionnear a flare site) that may be treated as a magnetized plasma waveguide. The electromagnetic waves excited inthe waveguide are classified into the so-called E-type and B-type waves. The results show that there are twounstable modes of B-type waves propagating parallel and anti-parallel to the direction of the electron beam. Theeffect of the finite radius and boundary conditions of the waveguide on the excitation of waveguide modes isimportant. For a given B-type mode, the smaller the radius R, the larger the temporal and spatial amplificationrate. We suggest that these excited waveguide modes could be one of the processes responsible for the observedsolar radio emission.

  13. Magnetic field effects on buckling behavior of smart size-dependent graded nanoscale beams

    Science.gov (United States)

    Ebrahimi, Farzad; Reza Barati, Mohammad

    2016-07-01

    In this article, buckling behavior of nonlocal magneto-electro-elastic functionally graded (MEE-FG) beams is investigated based on a higher-order beam model. Material properties of smart nanobeam are supposed to change continuously throughout the thickness based on the power-law model. Eringen's nonlocal elasticity theory is adopted to capture the small size effects. Nonlocal governing equations of MEE-FG nanobeam are obtained employing Hamilton's principle and they are solved using the Navier solution. Numerical results are presented to indicate the effects of magnetic potential, electric voltage, nonlocal parameter and material composition on buckling behavior of MEE-FG nanobeams. Therefore, the present study makes the first attempt in analyzing the buckling responses of higher-order shear deformable (HOSD) MEE-FG nanobeams.

  14. Effect Of The LEBT Solenoid Magnetic Field On The Beam Generation For Particle Tracking

    CERN Document Server

    Yarmohammadi Satri, M; CERN. Geneva. ATS Department

    2013-01-01

    Linac4 is a 160 MeV H- linear accelerator which will replace the 50 MeV proton Linac2 for upgrade of the LHC injectors with higher intensity and eventually an increase of the LHC luminosity. Linac4 structure is a source, a 45 keV low energy beam transport line (LEBT) with two solenoids, a 3 MeV Radiofrequency Quadrupole (RFQ), a Medium Energy Beam Transport line (MEBT), a 50 Mev DTL, a 100 Mev CCDTL and PIMS up to 160 Mev. We use Travel v4.07 and PathManager code for simulation. Firstly, we need to a file as a source and defining the beginning point (last point in tracking back) of simulation. We recognise the starting point base on the solenoid magnetic property of LEBT.

  15. 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.)

  16. Electron beam machining using rotating and shaped beam power distribution

    Science.gov (United States)

    Elmer, John W.; O'Brien, Dennis W.

    1996-01-01

    An apparatus and method for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: 1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and 2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1000 .mu.m (1 mm or larger), compared to the 250 .mu.m diameter of laser drilling.

  17. Design and Analysis Methodologies for Inflated Beams

    NARCIS (Netherlands)

    Veldman, S.L.

    2005-01-01

    The central theme of the thesis is bending behaviour of inflated beams. Three different types of beams have been analysed for the bending load case: a straight cylindrical beam made of anisotropic foil material, a conical beam made of an isotropic foil material, and a carbon fibre braided beam. The

  18. 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)

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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...

  4. 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

  5. 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.

  6. Formulation of the twisted-light--matter interaction at the phase singularity: beams with strong magnetic fields

    CERN Document Server

    Quinteiro, G F; Kuhn, T

    2016-01-01

    The formulation of the interaction of matter with singular light fields needs special care. In a recent article [Phys.~Rev.~A {\\bf 91}, 033808 (2015)] we have shown that the Hamiltonian describing the interaction of a twisted light beam having parallel orbital and spin angular momenta with a small object located close to the phase singularity can be expressed only in terms of the electric field of the beam. Here, we complement our studies by providing an interaction Hamiltonian for beams having antiparallel orbital and spin angular momenta. Such beams may exhibit unusually strong magnetic effects. We further extend our formulation to radially and azimuthally polarized beams. The advantages of our formulation are that for all beams the Hamiltonian is written solely in terms of the electric and magnetic fields of the beam and as such it is manifestly gauge-invariant. Furthermore it is intuitive by resembling the well-known expressions in the dipole-electric and dipole-magnetic moment approximations.

  7. Design study of a low-emittance lattice with a five-bend achromat

    Science.gov (United States)

    Liu, Hao-Lin; Kim, Eun-San

    2016-04-01

    The multi-bend achromat (MBA) lattice, which can provide a small horizontal emittance in the subnanometer range, shows promise for future storage-ring-based light-source facilities. We present the linear and the nonlinear properties of an optical design and the results of its optimization. The MBA lattice is designed as a five-bend achromat, and an emittance of 0.270 nm rad is achieved. The energy and the circumference of the designed ring are 3 GeV and 499.3 m, respectively. We investigated an injection system with a single-pulsed sextupole magnet in the storage ring. We describe the space allocation in the injection section and the particle dynamics of the injected beam. The investigation shows that our design exhibits a very low emittance and a sufficient dynamic aperture, and provides a suitable injection scheme for a 3-GeV light source.

  8. 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...

  9. 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...

  10. 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.

  11. Correlation of Beam Transport Characteristics and Mass Resolving Power to Analyzing Magnet Pole Piece Wear in Axcelis HE Ion Implanters

    Science.gov (United States)

    Johnson, Ron; Schuur, John; Tysinger, Randy

    2008-11-01

    An investigation into odd analyzing magnet tuning behavior on an Axcelis HE ion implanter revealed a correlation to excessive wear on the analyzer magnet pole pieces. Though the lifetime is generally quite good, the pole pieces are internal to the beamline design and are exposed to and sputtered by the ion beam during mass analysis. This erosion of the pole piece surfaces affects beam focus and transport, especially for lower current ion beams. Eventually, automatic beam set-up fails altogether as the system is unable to locate the correct amu peak. It is important to understand and correct any deficiencies in pole piece condition as long-term neglect will eventually lead to process errors. Data is presented to illustrate good and bad pole piece condition and a method is suggested for non-invasive testing.

  12. Results of the studies on energy deposition in IR6 superconducting magnets from continuous beam loss on the TCDQ system

    CERN Document Server

    Bracco, C; Presland, A; Redaelli, S; Sarchiapone, L; Weiler, T

    2007-01-01

    A single sided mobile graphite diluter block TCDQ, in combination with a two-sided secondary collimator TCS and an iron shield TCDQM, will be installed in front of the superconducting quadrupole Q4 magnets in IR6, in order to protect it and other downstream LHC machine elements from destruction in the event of a beam dump that is not synchronised with the abort gap. The TCDQ will be positioned close to the beam, and will intercept the particles from the secondary halo during low beam lifetime. Previous studies (1-4) have shown that the energy deposited in the Q4 magnet coils can be close to or above the quench limit. In this note the results of the latest FLUKA energy deposition simulations for Beam 2 are described, including an upgrade possibility for the TCDQ system with an additional shielding device. The results are discussed in the context of the expected performance levels for the different phases of LHC operation.

  13. 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)

  14. 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)

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Copper ion implanted aluminum nitride dilute magnetic semiconductors (DMS) prepared by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A., E-mail: attaullah77@yahoo.com [National Institute of Lasers and Optronics (NILOP), PO Nilore, Islamabad (Pakistan); DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Ahmad, Jamil [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Ahmad, Ishaq [Experimental Physics Lab, National Center for Physics (NCP), Islamabad (Pakistan); Mehmood, Mazhar [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Mahmood, Arshad [National Institute of Lasers and Optronics (NILOP), PO Nilore, Islamabad (Pakistan); Rasheed, Muhammad Asim [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan)

    2014-10-30

    Highlights: • AlN:Cu dilute magnetic semiconductors were successfully prepared by molecular beam epitaxy followed by Cu{sup +} 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{sup +} ions into AlN thin films at various ion fluxes. AlN films were deposited on c-plane sapphire by molecular beam epitaxy followed by Cu{sup +} 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 E{sub 2} (high) and A{sub 1} (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{sup +} 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

  20. 2D profile of poloidal magnetic field diagnosed by a laser-driven ion-beam trace probe (LITP)

    Science.gov (United States)

    Yang, Xiaoyi; Xiao, Chijie; Chen, Yihang; Xu, Tianchao; Lin, Chen; Wang, Long; Xu, Min; Yu, Yi

    2016-11-01

    Based on large energy spread of laser-driven ion beam (LIB), a new method, the Laser-driven Ion-beam Trace Probe (LITP), was suggested recently to diagnose the poloidal magnetic field (Bp) and radial electric field (Er) in toroidal devices. Based on another property of LIB, a wide angular distribution, here we suggested that LITP could be extended to get 2D Bp profile or 1D profile of both poloidal and radial magnetic fields at the same time. In this paper, we show the basic principle, some preliminary simulation results, and experimental preparation to test the basic principle of LITP.

  1. Investigation of the Chaotic Dynamics of an Electron Beam with a Virtual Cathode in an External Magnetic Field

    OpenAIRE

    Egorov, E. N.; Hramov, A. E.

    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 ...

  2. Effect of external magnetic field on critical current for the onset of virtual cathode oscillations in relativistic electron beams

    Science.gov (United States)

    Hramov, Alexander; Koronovskii, Alexey; Morozov, Mikhail; Mushtakov, Alexander

    2008-02-01

    In this Letter we research the space charge limiting current value at which the oscillating virtual cathode is formed in the relativistic electron beam as a function of the external magnetic field guiding the beam electrons. It is shown that the space charge limiting (critical) current decreases with growth of the external magnetic field, and that there is an optimal induction value of the magnetic field at which the critical current for the onset of virtual cathode oscillations in the electron beam is minimum. For the strong external magnetic field the space charge limiting current corresponds to the analytical relation derived under the assumption that the motion of the electron beam is one-dimensional [D.J. Sullivan, J.E. Walsh, E. Coutsias, in: V.L. Granatstein, I. Alexeff (Eds.), Virtual Cathode Oscillator (Vircator) Theory, in: High Power Microwave Sources, vol. 13, Artech House Microwave Library, 1987, Chapter 13]. Such behavior is explained by the characteristic features of the dynamics of electron space charge in the longitudinal and radial directions in the drift space at the different external magnetic fields.

  3. Effect of external magnetic field on critical current for the onset of virtual cathode oscillations in relativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Hramov, Alexander [Faculty of Nonlinear Processes, Saratov State University, Astrakhanskaya 83, Saratov 410012 (Russian Federation)], E-mail: aeh@nonlin.sgu.ru; Koronovskii, Alexey; Morozov, Mikhail; Mushtakov, Alexander [Faculty of Nonlinear Processes, Saratov State University, Astrakhanskaya 83, Saratov 410012 (Russian Federation)

    2008-02-04

    In this Letter we research the space charge limiting current value at which the oscillating virtual cathode is formed in the relativistic electron beam as a function of the external magnetic field guiding the beam electrons. It is shown that the space charge limiting (critical) current decreases with growth of the external magnetic field, and that there is an optimal induction value of the magnetic field at which the critical current for the onset of virtual cathode oscillations in the electron beam is minimum. For the strong external magnetic field the space charge limiting current corresponds to the analytical relation derived under the assumption that the motion of the electron beam is one-dimensional [D.J. Sullivan, J.E. Walsh, E. Coutsias, in: V.L. Granatstein, I. Alexeff (Eds.), Virtual Cathode Oscillator (Vircator) Theory, in: High Power Microwave Sources, vol. 13, Artech House Microwave Library, 1987, Chapter 13]. Such behavior is explained by the characteristic features of the dynamics of electron space charge in the longitudinal and radial directions in the drift space at the different external magnetic fields.

  4. DIRAC detector experiment: the vacuum chamber (blue), beginning of the flat chamber (yellow), magnetic screen (orange) in front of the magnet. The vacuum tube for the primary proton beam is below (sil ver color)

    CERN Multimedia

    Patrice Loïez

    1999-01-01

    DIRAC detector experiment: the vacuum chamber (blue), beginning of the flat chamber (yellow), magnetic screen (orange) in front of the magnet. The vacuum tube for the primary proton beam is below (sil ver color)

  5. 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...

  6. A magnetically isolated diode with Bτ-field as a generator of high-power microsecond ion beam

    International Nuclear Information System (INIS)

    The results of a study of the generation of a high-power microsecond ion beam in a planar magnetically isolated diode with external radially distributed isolating field are presented. A ring cross-section ion beam consisting mainly of H+ and C+ ions was studied. The energy range of most of the generated ions is 300-500 keV. The total energy stored in the beam extracted from the diode is 10 kJ and the generation efficiency reaches 60%. 5 refs., 4 figs

  7. Construction and measurement of the pre-series twin aperture resistive quadrupole magnet for the LHC beam cleaning insertions

    CERN Document Server

    de Rijk, G; Boter, E; Clark, G S; Hans, O; Racine, M; Salinas, A

    2002-01-01

    CERN's Large Hadron Collider (LHC) requires 48 twin aperture resistive quadrupoles in the beam cleaning insertions. Canada is contributing these magnets to CERN in the framework of the TRIUMF-LHC collaboration contracts. A pre-series magnet was produced by Canadian industry and delivered in March 2001. This magnet incorporates important design changes that resulted from experience with a prototype magnet. The construction of this pre-series magnet and the measurements made at ALSTOM and at CERN are reported. A comparison is made between high precision pole distance measurements and the magnetic measurements performed with a rotating coil mole. Conclusions for series production and possibilities for multipole corrections are outlined. (6 refs).

  8. 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...

  9. Hall full of LEP magnets waiting to be installed in November 1987

    CERN Multimedia

    1987-01-01

    The white magnets in the background are LEP's innovative dipole magnets. They are made of plates of stell with the intervening spaces filled out with concrete. For the relatively low bending fields used in LEP, this technique offers a much cheaper alternative to solid steel costing about half the price. The blue magnets in the foreground are quadrupole focusing magnets and the small yellow magnets in the background are sextupoles which correct the beams "chromaticity", just as optical systems correct for the different wavelengths which make up light, these sextupoles correct for the spread of momenta in LEP's particle beams.

  10. Correction of the Long-Range Beam-Beam Effect in LHC using Electro-Magnetic Lenses

    CERN Document Server

    Koutchouk, Jean-Pierre

    2001-01-01

    The beams in LHC collide head-on in at most four experimental points. Due to the small bunch spacing, the beams experience more than one hundred 'near-misses' on either side of the collision points. The transverse beam separation at these places, limited by the quadrupole aperture, is in the range of 7 to 13 sigma. The non-linear part of these 'long-range' interactions appears to be the dominant mechanism for beam blow-up or beam loss in simulation. A simple non-linear model of the long-range interactions can be devised. It shows that the latter may be locally corrected with good accuracy using wires as correcting lenses. The non-linearity measured by the tune footprint is reduced by one order of magnitude. Pulsing the correcting lenses cancels the so-called PACMAN effect.

  11. Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Small Solenoidal Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-08-01

    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 analytical 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 analytical studies show that the solenoidal magnetic field starts to influence 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 analytical theory have been verified by comparison with the simulation results obtained from two particle-in-cell codes, which show good agreement.

  12. Annular electron beam production on gamble II using a magnetically insulated splitter

    International Nuclear Information System (INIS)

    Annular electron beams have been tested using a post-hole convolute or magnetically insulated splitter (MIS) to feed current to both sides of a ring cathode. Beams were produced on the BLACKJACK 3 generator using a coaxial feed and from BLACKJACK 5 with a triplate feed. On BLACKJACK 3, annular cathodes with 5 cm and 10 cm mean diameters were tested. The cathodes were fed in four places by a MIS. The cathodes were 1.2 cm wide made from stainless steel or brass. Typical anode/cathode gap spacings were 0.6 cm. Experiments were performed at power levels of about 0.6 TW and energies of 30-40 kJ. Typical voltages were 0:6-1 MV with currents of about 0.8 MA. Diagnostics were diode voltage, diode current, and an X-ray pinhole camera. For the 10 cm cathode, current was measured before and after the MIS. The current on each side of the ring was measured separately. The beam voltage was determined from the diode voltage by an inductive correction. The annular beams had a linear current density of about 30 kA/cm and about 60 kA/cm for the 10 cm and 5 cm, respectively. The beam diameter at the cathode could be varied by changing the inductance on each side of the ring cathode and thereby the current balance. The impedance behavior could be modeled using the critical current formulation with a closure velocity of 3.5-4.5 cm/us. The BLACKJACK 5 geometry was a triplate feed. The ring cathode was fed by generators of 0.5 and 0.75 Ω, respectively. The MIS was used to combine the power before the cathode. The cathode had a mean diameter of 25 cm and width of 1.5-3 cm. Experiments were performed at power levels up to about6 TW and energies greater than or equal to200 kJ. Typical operating parameters were about 2 MV and 3 MA

  13. Beam dynamics of CANDLE storage ring low alpha operation

    Science.gov (United States)

    Sargsyan, A.; Amatuni, G.; Sahakyan, V.; Tsakanov, V.; Zanyan, G.

    2015-10-01

    The generation of the coherent THz radiation and short pulse synchrotron radiation in dedicated electron storage rings requires the study of non-standard magnetic lattices which provide low momentum compaction factor (alpha) of the ring. In the present paper two low alpha operation lattices based on modification of the original beam optics and implementation of inverse bend magnets are studied for CANDLE storage ring. For considered cases an analysis of transverse and longitudinal beam dynamics is given and the feasibility of lattices is discussed.

  14. Beam dynamics of CANDLE storage ring low alpha operation

    International Nuclear Information System (INIS)

    The generation of the coherent THz radiation and short pulse synchrotron radiation in dedicated electron storage rings requires the study of non-standard magnetic lattices which provide low momentum compaction factor (alpha) of the ring. In the present paper two low alpha operation lattices based on modification of the original beam optics and implementation of inverse bend magnets are studied for CANDLE storage ring. For considered cases an analysis of transverse and longitudinal beam dynamics is given and the feasibility of lattices is discussed

  15. Interferometric measurement of the beam size in the compact storage ring

    CERN Document Server

    Yamamoto, Y; Mitsuhashi, T; Amano, D; Iwasaki, H

    2001-01-01

    The beam size in the compact superconducting storage ring AURORA at Ritsumeikan University was measured using the SR-interferometer. The radiation beam from the bending magnet was passed through the double-slit and an interferogram formed in the visible spectral region was recorded using a CCD camera. The spatial coherence of the beam was derived from the analysis of the intensity profile and its dependence on the spatial frequency has yielded the beam size of 10.5 mu m in the vertical direction. It is unexpectedly small, indicating a high accuracy in the design of magnetic field in the magnet. The beam size could be varied by applying an rf kick electric field and the dependence of the beam lifetime on the size has shown that it is primarily governed by the Tauschek effect.

  16. 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)

  17. Molecular beam epitaxy growth and magnetic properties of Cr-Co-Ga Heusler alloy films

    International Nuclear Information System (INIS)

    We have re-investigated growth and magnetic properties of Cr2CoGa films using molecular beam epitaxy technique. Phase separation and precipitate formation were observed experimentally again in agreement with observation of multiple phases separation in sputtered Cr2CoGa films by M. Meinert et al. However, significant phase separation could be suppressed by proper control of growth conditions. We showed that Cr2CoGa Heusler phase, rather than Co2CrGa phase, constitutes the majority of the sample grown on GaAs(001) at 450 oC. The measured small spin moment of Cr2CoGa is in agreement with predicted HM-FCF nature; however, its Curie temperature is not as high as expected from the theoretical prediction probably due to the off-stoichiometry of Cr2CoGa and the existence of the disorders and phase separation

  18. High-power microwave amplifier based on overcritical relativistic electron beam without external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kurkin, S. A., E-mail: KurkinSA@gmail.com; Koronovskii, A. A. [Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation); Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Frolov, N. S.; Hramov, A. E. [Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation); Rak, A. O. [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus); Saratov State Technical University, Politechnicheskaja 77, Saratov 410028 (Russian Federation); Kuraev, A. A. [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus)

    2015-04-13

    The high-power scheme for the amplification of powerful microwave signals based on the overcritical electron beam with a virtual cathode (virtual cathode amplifier) has been proposed and investigated numerically. General output characteristics of the virtual cathode amplifier including the dependencies of the power gain on the input signal frequency and amplitude have been obtained and analyzed. The possibility of the geometrical working frequency tuning over the range about 8%–10% has been shown. The obtained results demonstrate that the proposed virtual cathode amplifier scheme may be considered as the perspective high-power microwave amplifier with gain up to 18 dB, and with the following important advantages: the absence of external magnetic field, the simplicity of construction, the possibility of geometrical frequency tuning, and the amplification of relatively powerful microwave signals.

  19. Application of magnetically insulated transmission lines for high current, high voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Self Magnetically Insulated Transmission Lines (MITL) adders have been used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently the authors used a MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (rb < 2 cm), 11 to 15 MeV, 50 to 100-kA beams with a small transverse velocity v perpendicular/c = β perpendicular ≤ 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. The authors' success with the MITL technology led them to investigate the application to higher energy accelerator designs. They have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30-50-ns FWHM output pulse

  20. Application of Magnetically Insulated Transmission Lines for high current, high voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Self Magnetically Insulated Transmission Lines (MITL) adders have been used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently we used at MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (rρ < 2 cm), 11 to 15 MeV, 50 to 100-kA beams with a small transverse velocity v perpendicular/c = β perpendicular ≤ 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. Our success with the MITL technology led us to investigate the application to higher energy accelerator designs. We have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30--50 ns FWHM output pulse. 10 refs

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

    CERN Document Server

    Muchnoi, N; 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 sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of $10^{-4}$ or bette...

  2. The thickness-dependent dynamic magnetic property of Co2FeAl films grown by molecular beam epitaxy

    Science.gov (United States)

    Qiao, Shuang; Nie, Shuaihua; Zhao, Jianhua; Zhang, Xinhui

    2014-10-01

    Co2FeAl films with different thickness were prepared at different temperature by molecular beam epitaxy. Their dynamic magnetic property was studied by the time-resolved magneto-optical Kerr effect measurements. It is observed that the intrinsic damping factor of Co2FeAl for [100] orientation is not related to the film's thickness and magnetic anisotropy as well as temperature at high-field regime, but increases with structural disorder of Co2FeAl. The dominant contribution from the inhomogeneous magnetic anisotropy is revealed to be responsible for the observed extremely nonlinear and drastic field-dependent damping factors at low-field regime.

  3. Effect of annealing on magnetic properties of Nd-Fe-B thin films prepared by ECR ion beam sputtering method

    Science.gov (United States)

    Tokumaru, R.; Tamano, S.; Goto, S.; Madeswaran, S.; Tokiwa, K.; Watanabe, T.

    2009-11-01

    Nd-Fe-B thin films were prepared by electron cyclotron resonance (ECR) ion beam sputtering and subsequent annealing. The influence of annealing on the magnetic properties and X-ray diffraction patterns of the product films was investigated. Amorphous films deposited at room temperature were annealed at temperatures between 600 and 800 °C. The c-axis oriented crystallization of the Nd2Fe14B phase did not appear by annealing of the buffer layer and magnetic Nd-Fe-B layer deposited at room temperature, and the hysteresis loops of the films indicated magnetic isotropy.

  4. Effect of annealing on magnetic properties of Nd-Fe-B thin films prepared by ECR ion beam sputtering method

    International Nuclear Information System (INIS)

    Nd-Fe-B thin films were prepared by electron cyclotron resonance (ECR) ion beam sputtering and subsequent annealing. The influence of annealing on the magnetic properties and X-ray diffraction patterns of the product films was investigated. Amorphous films deposited at room temperature were annealed at temperatures between 600 and 800 0C. The c-axis oriented crystallization of the Nd2Fe14B phase did not appear by annealing of the buffer layer and magnetic Nd-Fe-B layer deposited at room temperature, and the hysteresis loops of the films indicated magnetic isotropy.

  5. Effect of annealing on magnetic properties of Nd-Fe-B thin films prepared by ECR ion beam sputtering method

    Energy Technology Data Exchange (ETDEWEB)

    Tokumaru, R; Tamano, S; Goto, S; Tokiwa, K; Watanabe, T [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Madeswaran, S, E-mail: j8107632@ed.noda.tus.ac.j [Polyscale Technology Research Center, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

    2009-11-15

    Nd-Fe-B thin films were prepared by electron cyclotron resonance (ECR) ion beam sputtering and subsequent annealing. The influence of annealing on the magnetic properties and X-ray diffraction patterns of the product films was investigated. Amorphous films deposited at room temperature were annealed at temperatures between 600 and 800 {sup 0}C. The c-axis oriented crystallization of the Nd{sub 2}Fe{sub 14}B phase did not appear by annealing of the buffer layer and magnetic Nd-Fe-B layer deposited at room temperature, and the hysteresis loops of the films indicated magnetic isotropy.

  6. Effect of longitudinal applied magnetic field on the self-pinched critical current in intense electron beam diode

    Institute of Scientific and Technical Information of China (English)

    Liu Guo-Zhi; Huang Wen-Hua; Shao Hao; Xiao Ren-Zhen

    2006-01-01

    The effect of applied longitudinal magnetic field on the self-pinched critical current in the intense electron beam diode is discussed. The self-pinched critical current is derived and its validity is tested by numerical simulations. The results shows that an applied longitudinal magnetic field tends to increase the self-pinched critical current. Without the effect of anode plasma, the maximal diode current approximately equals the self-pinched critical current with the longitudinal magnetic field applied; when self-pinched occurs, the diode current approaches the self-pinched critical current.

  7. Beam-dump/diagnostics box for a 10-kA 50-MeV, 50-ns electron beam

    International Nuclear Information System (INIS)

    We have developed a dump for the ATA beam that consists of a series of carbon plates whose collective thickness totals approximately 1.5 ranges at 50 MeV. The energy dissipated in the plates is radiated to a water-cooled wall. The dump is designed to dissipate up to 175 kW of average power. A small hole along the axis of the plates forms a beamlet that passes through an energy analyzer. The analyzer consists of a 600 bending magnet and two high-sensitivity beam-current/position monitors. The ratio of the beamlet current to full current is used to estimate the beam emittance

  8. Energy Recovery from a Space-Charge Neutralized Positive Ion Beam by Means of Magnetic Electron Suppression

    Science.gov (United States)

    Ryan, Philip Michael

    The charge-exchange neutralization efficiency of positive ion based neutral beams used in plasma heating applications decreases as the beam energy increases. Direct energy recovery from the charged particles can be accomplished by electrostatically decelerating the positive ions; the problem is to effect this without accelerating the space -charge neutralizing electrons residing in the beam. Prior work with both electrostatic and magnetic electron suppression is reviewed. A finite difference ion optics code which solves the nonlinear Vlasov-Poisson equation is adapted to energy recovery application and used to analyze the transverse magnetic field electron suppression experiments carried out at Oak Ridge National Laboratory between 1980 and 1982. Three numerical models are discussed and evaluated. The double plasma model, which assumes an equilibrium Boltzmann distribution of electrons at both the neutralizer potential and the ion collector potential, most successfully duplicates the experimental results with beams in the 40 keV, 10 A range. It is used to analyze the effects of the magnetic field strength, the ion "boost" energy, and the ion beam current density on the ion collection efficiency. Conclusions of the study are: (1) the electron leakage current scales as B('-1), necessitating magnetic suppression fields in excess of 0.1 tesla; (2) the neutralizer geometry should provide an electrostatic field to counteract the magnetic force on the ions; (3) fractional energy beam ions should be confined to the neutralizer interior; (4) the neutral line density in the recovery region should be less than 3 x 10('-3) torr(.)cm. Recovery efficiency decreases with increasing beam current density; a net recovery efficiency of 30% (ion collection efficiency of 75%) at 5 mA/cm('2) falls to zero at 10 mA/cm('2) for a 40 keV beam. New designs are presented and analyzed: an ion collection efficiency of close to 90% is predicted for an 80 keV D ion beam with an ion current

  9. Stability of high field superconducting dipole magnets

    International Nuclear Information System (INIS)

    Superconducting dipole magnets of the window-frame type were constructed and operated successfully at Brookhaven National Laboratory. Examples of this type of magnet are the 6 T ''Model T'' magnet, and the 4 T 80 superconducting bending magnet. The latter magnet operated reliably since October 1973 as part of the proton beam transport to the north experimental area at the BNL AGS with intensities of typically 8 x 1012 protons at 28.5 GeV/c passing through the magnet in a curved trajectory with the proton beam center only 2.0 cm from the beam pipe at both ends and the middle of each of the two units comprising the magnet. The energy in the beam is approximately 40 kJ per 3 μsec pulse. Targets were inserted in the beam at locations 2 m and 5.6 m upstream of the first magnet unit to observe the effects of radiation heating. The 80 magnet demonstrated ultrastability, surviving 3 μsec thermal pulses delivering up to 1 kJ into the cold magnet at repetition periods as short as 1.3 sec

  10. Transportation system for heavy ion beams extracted from cyclotron DC-60

    International Nuclear Information System (INIS)

    Calculations of the extraction channels of the heavy ion beams extracted from the DC-60 cyclotron were carried out. On the basis of these calculations the extraction channels were designed and manufactured. Channel 1 has the length of about 14.4 m from its beginning to the target and is intended for film irradiation by different types of heavy ions. Focusing of the extracted ion beams on channel 1 is carried out by two quadrupoles. The ion beam scanning system (vertical and horizontal magnetic scanners) is situated after the bending magnet. Channels 2 and 3 work when the bending magnet is switched on. It deflects the ion beams at the angle ± 30 deg. The quadrupole doublets are situated after the bending magnet in channels 2 and 3. The tables of calculated gradients in all quadrupoles and dependences of the beam semidimensions along the channels for different points of the cyclotron operating diagram are given. The characteristics of the basic optical elements of the channels are also given here

  11. Modeling and analysis of controllable output property of cantilever-beam inertial sensors based on magnetic fluid

    Institute of Scientific and Technical Information of China (English)

    Guixiong LIU; Peiqiang ZHANG; Chen XU

    2009-01-01

    Magnetic fluid is first introduced into thetraditional cantileverbeam senor. Based on the property of the cantilever-beam and the novel controllable mag-viscosity of magnetic fluid, the output of cantilever-beam sensors is under control so that the controllable output of the sensors can be realized. The mathematical model of the sensors is established and analyzed. The dynamic control function and the following educational results, which include the two curves of the displacement ratio and phase function with the different damping ratio and frequency ratio, are obtained based on the model. The result shows that it is valid to realize the controllable output of the sensors by controlling the viscosity of the magnetic fluid,and finally the expanded measurement range can be realized.

  12. 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)

  13. The beam transport system in the SRS-1200

    CERN Document Server

    Ivashchenko, V E

    2002-01-01

    In NSC KIPT the synchrotron radiation source SRS-1200 for the Ukrainian national synchrotron center (Kiev) is developed. An injector for a storage ring is the electron linear accelerator with energy 180 MeV. For compactness of a complex LUE-180 dispose under a storage ring. The transport system provides transport of electron beam from linear accelerator without losses and injection him in the storage ring. The calculations of the performances of transport systems with five-lens and three-lens variants of translation line, and also with use 42 and 45-th of degree rectangular and sector bending magnets were carried out. As a result of the comparative analysis the five-lens symmetric variant of translation line with 42-th degree sector bending magnets was chosen. In the report the basic results of calculations, parameters and performances of transport system of electron beam are submitted.

  14. Vlasov's kinetic theory of the collective charged particle beam transport through a magnetized plasma in the strongly nonlocal regime

    International Nuclear Information System (INIS)

    Plasma-based accelerator schemes represent the first step of the research-development of the future accelerator machines. Within the Vlasov's kinetic theory, describing the plasma wake field interaction, the collective transport of a warm non-laminar relativistic charged particle beam is analyzed in the strongly nonlocal regime, where the beam spot-size is much less than the plasma wavelength. This is done in the overdense regime, i.e., the beam density is much less than the plasma density. The beam is supposed to be sufficiently long to experience the adiabatic shielding by the plasma. In these conditions, we neglect the longitudinal beam dynamics and focus on the transverse one only. We derive the virial description (envelope description) from the 2D Vlasov-Poisson-type system of equations that governs the transverse self-consistent plasma wake field excitation. The resulting envelope equation is then reduced, in the aberration-less approximation, to a differential equation for the beam spot size, where the role of the ambient magnetic field is evaluated in both laboratory and astrophysical environments. An analysis of the beam envelope self-modulation is then carried out and the criteria for the occurrence of the instability are found. (authors)

  15. RADIAL BASIS COLLOCATION METHOD FOR BENDING PROBLEMS OF BEAM AND PLATE%基于径向基函数配点法的梁板弯曲问题分析

    Institute of Scientific and Technical Information of China (English)

    王莉华; 仲政

    2012-01-01

    采用径向基函数配点法分析考虑剪切效应的梁板弯曲问题,该方法利用径向基函数作为近似函数,基于配点法离散方程,通过最小二乘法求解.径向基函数配点法在离散和计算过程中不需要划分任何形式的网格,是一种真正的无网格法;径向基函数可以用一元函数来描述多元函数,存在明显的储存和运算简单的特点;而基于配点法求解不需要积分,提高了计算效率.分析考虑剪切效应的薄梁板问题时,传统的有限元法或无网格法求解均会存在剪切锁闭问题,而径向基函数在全域内存在无限连续性,能够准确地满足Kirchhoff约束条件,因此径向基函数配点法能够消除剪切锁闭现象,而且不会出现应力波动.该方法的优势在于,其不仅易于离散、精度高,而且具有指数收敛率,计算效率高.数值算例验证了上述结论和该方法的稳定性.%Radial basis collocation method is introduced to analyze the bending problems of Timoshen-ko beam and Reissner-Mindlin plate. The radial basis functions are employed for approximation,the collocation method is utilized for discretization,and the least squares approach is adopted to solve the discretized equations. No mesh will be required in the discretization and resolution and so radial basis collocation method is a truly meshfree method. 1-D radial basis functions can represent all the 2-D or 3-D radial functions which greatly reduce the memory space. No integration will be used in collocation method which improves the computational efficiency. For resolving the problems of thin Timoshenko beam and Reissner-Mindlin plate,analysis demonstrates that radial basis collocation method is free of locking since the shape functions with infinite continuity can satisfy the Kirchhoff constraint conditions, and no stress oscillation is observed, while conventional finite element method and conventional meshfree methods suffer locking problems. The

  16. A hydrogen ion beam method of molecular density measurement inside a 4.2-K beam tube

    International Nuclear Information System (INIS)

    In our first experiments on synchrotron radiation-induced photodesorption in a 4.2-K beam tube, the moleculm density was measured by room temperature ion gauges and RGAs outside the beam tube. The molecular density inside the 4.2-K beam tube was therefore unknown, since the mean molecular speed of photodesorbed molecules had not been measured. To determine the density inside the 4.2-K beam tube we have developed a direct method of measurement utilizing the neutralization of H+ beams, which are proportional to gas density. The hydrogen ion beams (up to 20 keV, ∼1 μA) are extracted from an rf ion source and guided into the cold beam tube by a bending magnet. The H0 and H- produced in the beam tube are magnetically separated from H- and detected with secondary electron multipliers (SEMs). Small superconducting dipole magnets located near the center of the beam tube allow a ∼20-cm segment of the injected ion beam to be offset a few mm from the injection axis; detection of H0 and H- produced along this offset segment provides a localized density measurement. If necessary, detector background due to synchrotron radiation photons can be discriminated against by gating the detector on between the bursts of synchrotron radiation. The experimental setup and initial data will be presented

  17. A hydrogen ion beam method of molecular density measurement inside a 4.2-K beam tube

    Energy Technology Data Exchange (ETDEWEB)

    Alinovsky, N.; Anashin, V.; Beschasny, P. [Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)] [and others

    1994-06-01

    In our first experiments on synchrotron radiation-induced photodesorption in a 4.2-K beam tube, the moleculm density was measured by room temperature ion gauges and RGAs outside the beam tube. The molecular density inside the 4.2-K beam tube was therefore unknown, since the mean molecular speed of photodesorbed molecules had not been measured. To determine the density inside the 4.2-K beam tube we have developed a direct method of measurement utilizing the neutralization of H{sup +} beams, which are proportional to gas density. The hydrogen ion beams (up to 20 keV, {approximately}1 {mu}A) are extracted from an rf ion source and guided into the cold beam tube by a bending magnet. The H{sup 0} and H{sup {minus}} produced in the beam tube are magnetically separated from H{sup {minus}} and detected with secondary electron multipliers (SEMs). Small superconducting dipole magnets located near the center of the beam tube allow a {approximately}20-cm segment of the injected ion beam to be offset a few mm from the injection axis; detection of H{sup 0} and H{sup {minus}} produced along this offset segment provides a localized density measurement. If necessary, detector background due to synchrotron radiation photons can be discriminated against by gating the detector on between the bursts of synchrotron radiation. The experimental setup and initial data will be presented.

  18. Magnetic focusing of an intense slow positron beam for enhanced depth-resolved analysis of thin films and interfaces

    CERN Document Server

    Falub, C V; Mijnarends, P E; Schut, H; Veen, A V

    2002-01-01

    The intense reactor-based slow positron beam (POSH) at the Delft research reactor has been coupled to a Two-Dimensional Angular Correlation of Annihilation Radiation (2D-ACAR) setup. The design is discussed with a new target chamber for the 2D-ACAR setup based on Monte Carlo simulations of the positron trajectories, beam energy distribution and beam transmission in an increasing magnetic field gradient. Numerical simulations and experiment show that when the slow positron beam with a FWHM of 11.6 mm travels in an increasing axial magnetic field created by a strong NdFeB permanent magnet, the intensity loss is negligible above approx 6 keV and a focusing factor of 5 in diameter is achieved. Monte Carlo simulations and Doppler broadening experiments in the target region show that in this configuration the 2D-ACAR setup can be used to perform depth sensitive studies of defects in thin films with a high resolution. The positron implantation energy can be varied from 0 to 25 keV before entering the non-uniform mag...

  19. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Science.gov (United States)

    Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  20. Bend-twist coupling potential of wind turbine blades

    DEFF Research Database (Denmark)

    Fedorov, Vladimir; Berggreen, Christian

    2014-01-01

    and tested on small-scale coupled composite beams. In the proposed method the coupling coefficient for a generic beam is introduced based on the Euler-Bernoulli beam formulation. By applying the developed method for analysis of a commercial wind turbine blade structure it is demonstrated that a bend......In the present study an evaluation of the potential for bend-twist coupling effects in wind turbine blades is addressed. A method for evaluation of the coupling magnitude based on the results of finite element modeling and full-field displacement measurements obtained by experiments is developed......-twist coupling magnitude of up to 0.2 is feasible to achieve in the baseline blade structure made of glass-fiber reinforced plastics. Further, by substituting the glass-fibers with carbon-fibers the coupling effect can be increased to 0.4. Additionally, the effect of introduction of bend-twist coupling...

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

    International Nuclear Information System (INIS)

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

  2. COMPARISON OF VIBRATION PERFORMANCE OF A SANDWICH CLAMPED-CLAMPED BEAM WITH MAGNETS VERSUS CONVENTIONAL CONSTRAINED DAMPING TREATMENTS

    Institute of Scientific and Technical Information of China (English)

    ZhengHuiming; HeZeng; LiMing; ZhaoGaoyu

    2004-01-01

    This paper investigates how the magnetic constrained layer damping (MCLD) treatment suppresses the displacement and acceleration resonant peak of a clamped-clamped beam. Because MCLI) treatment reduces input work and gives more dissipation energy, the vibration from external excitation can be effectively suppressed.The vibration reduction effects of MCLD and other conventional constrained damping treatments are also evaluated. In many cases, using MCLD treatments can yield smaller displacement and acceleration resonant peak especially in mode 1 compared to the other treatments without greatly changing the natural frequencies of the base beam.

  3. CFRP加固混凝土梁抗弯极限承载力计算方法%Calculating Method of Bending Ultimate Bearing Capacity of CFRP Reinforced Concrete Beam

    Institute of Scientific and Technical Information of China (English)

    林巧吟

    2009-01-01

    The article studies the destroyed form and ultimate status of carbon fiber material strengthened steel reinforced concrete bending members, and puts forward a practical calculation method for the front sectional bending bearing capacity, which can provide the reference for the practical engineering design.%该文对碳纤维材料补强加固钢筋混凝土抗弯构件的破坏形态和极限状态进行了研究,提出了正截面受弯承载力的实用计算方法,可为实际工程设计提供参考.

  4. Magnetic-ion-doped silicon nanostructures fabricated by ion implantation and electron beam annealing

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Fang, E-mail: v.fang@gns.cri.nz [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand); Johnson, Peter B. [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand); Kennedy, John; Markwitz, Andreas [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington (New Zealand)

    2013-07-15

    Magnetic-ion-doped Si nanostructures (nanowhiskers) were fabricated by a two-step process on Si (1 0 0) substrates. The substrates were implanted with 7 keV Fe{sup +} to a fluence (F) in the range 1 × 10{sup 13}–4 × 10{sup 15} Fe{sup +} cm{sup −2} prior to electron beam annealing (EBA) for 15 s at a maximum temperature, T, in the range 600–1100 °C. The two-step process was found to produce nanowhiskers at higher surface densities than those produced by applying EBA alone. With increase in Fe{sup +} fluence there is a striking increase in the surface density of the Si nanowhiskers, together with a decrease in the average height. For example, for T = 1000 °C, the density and average height are respectively 12 μm{sup −2} and 8.8 nm for F = 1 × 10{sup 13} Fe{sup +} cm{sup −2}, and 82 μm{sup −2} and 3.1 nm for F = 4 × 10{sup 15} Fe{sup +} cm{sup −2}. The results are compared with those from a three-step process in which the nanowhiskers are pre-formed in a prior EBA treatment. The two-step process is found to be superior for producing high densities with height distributions having lower fractional spreads. The mechanism of the nucleation and growth of nanowhiskers in the final EBA step is discussed. Selected results are presented to show the possibility of controlling the density and average height of Si nanowhiskers doped with magnetic ions for spin-dependent enhanced field emission.

  5. Magnetic-ion-doped silicon nanostructures fabricated by ion implantation and electron beam annealing

    Science.gov (United States)

    Fang, Fang; Johnson, Peter B.; Kennedy, John; Markwitz, Andreas

    2013-07-01

    Magnetic-ion-doped Si nanostructures (nanowhiskers) were fabricated by a two-step process on Si (1 0 0) substrates. The substrates were implanted with 7 keV Fe+ to a fluence (F) in the range 1 × 1013-4 × 1015 Fe+ cm-2 prior to electron beam annealing (EBA) for 15 s at a maximum temperature, T, in the range 600-1100 °C. The two-step process was found to produce nanowhiskers at higher surface densities than those produced by applying EBA alone. With increase in Fe+ fluence there is a striking increase in the surface density of the Si nanowhiskers, together with a decrease in the average height. For example, for T = 1000 °C, the density and average height are respectively 12 μm-2 and 8.8 nm for F = 1 × 1013 Fe+ cm-2, and 82 μm-2 and 3.1 nm for F = 4 × 1015 Fe+ cm-2. The results are compared with those from a three-step process in which the nanowhiskers are pre-formed in a prior EBA treatment. The two-step process is found to be superior for producing high densities with height distributions having lower fractional spreads. The mechanism of the nucleation and growth of nanowhiskers in the final EBA step is discussed. Selected results are presented to show the possibility of controlling the density and average height of Si nanowhiskers doped with magnetic ions for spin-dependent enhanced field emission.

  6. Simulation and measurement of an electron beam in a wiggler magnetic field

    International Nuclear Information System (INIS)

    Sources of high quality beams of spinning electron beams are critical to efficient free electron devices including FELs, CARMs and gyrotrons. Bifilar helical wigglers can take a beam with little perpendicular momentum and add perpendicular momentum, spinning up the beam. The effect of the electron beam self fields on the beam quality will be important. A computer simulation has been written which can simulate the behavior of electron beams in the wiggler region including the effects of the beam self-electric fields. The equations used in the code are described. Several tests of the code are presented. Results of simulation of a bifilar helical wiggler are described. Measurement of beam parameters is also necessary. A design for a capacitive axial velocity probe is presented. The probe has been built but is still untested due to problems with a leaky flange. 15 refs

  7. High precision pulse magnet power supply development for SACLA beam-line switch and pulse NMR measurement

    International Nuclear Information System (INIS)

    In order to achieve quasi-simultaneous operation of multi-XFEL beamlines, a pulse-by-pulse electron beam switching system has been developed at SACLA. In this system, a kicker magnet deflects the electron bunch, whose maximum repetition is 60 Hz, into three directions. The power supply for the kicker magnet generates trapezoidal current waveforms, whose polarity and amplitude can be flexibly changed. The stability of the pulsed current is found to be less than 11ppm. The magnetic field at a flat top (4ms) of the trapezoidal waveform is measured by using newly developed NMR system. The magnetic field stability better than 15ppm is confirmed with this NMR. In this paper, the design and development of the high-precision pulse power supply and the newly developed NMR system are described. (author)

  8. Focused neutral beams with low chaotic divergence for plasma heating and diagnostics in magnetic fusion devices

    International Nuclear Information System (INIS)

    A series of neutral beam injectors has been developed in the Budker Institute of Nuclear Physics for plasma heating and diagnostics in modern fusion devices. Ion optical system of these injectors is optimized to produce ion beams with low angular divergence. In order to provide beam focusing, the grids are formed to be spherical segments. Such geometrically focused neutral beams are particularly advantageous for plasma diagnostics when high spatial resolution is required. Another application of these beams is plasma heating in the machines with narrow ports through which only small size, high power density beams can be transported. (author)

  9. Note: Spectrometer with multichannel photon-counting detector for beam emission spectroscopy in magnetic fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Lizunov, A. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Khilchenko, A. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630073 Novosibirsk (Russian Federation); Khilchenko, V.; Kvashnin, A.; Zubarev, P. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)

    2015-12-15

    A spectrometer based on a linear array photomultiplier tube (PMT) has been developed and calibrated. A 0.635 m focal length Czerny-Turner monochromator combined with a coupling optics provides an image of a narrow 0.5 nm spectral range with a resolution of 0.015 nm/channel on a 32-anode PMT. The system aims at spectroscopy of D{sub α} or H{sub α} lines emitted by a diagnostic atomic beam in a plasma (primarily a motional Stark effect diagnostics). To record a low photon flux of ∼10{sup 6} s{sup −1} per channel with the time resolution of 100 μs, a pulse counting approach has been used. Wideband amplifiers scale single-electron pulses and transmit them to a digital data processing core hardwired in a programmable logic matrix. Calibrations have shown that the aberration-limited instrument function fits to a single detector channel of 1 mm width. Pilot results of passive measurements of D{sub α} light emission from the plasma confined in a magnetic trap are presented.

  10. Molecular beam epitaxy growth and magnetic properties of Cr-Co-Ga Heusler alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Wuwei, E-mail: wfeng@cugb.edu.cn; Wang, Weihua [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Zhao, Chenglong [Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Van Quang, Nguyen; Cho, Sunglae, E-mail: slcho@ulsan.ac.kr [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Dung, Dang Duc [Department of General Physics, School of Engineering Physics, Ha Noi University of Science and Technology, 1 Dai Co Viet Road, Ha Noi (Viet Nam)

    2015-11-15

    We have re-investigated growth and magnetic properties of Cr{sub 2}CoGa films using molecular beam epitaxy technique. Phase separation and precipitate formation were observed experimentally again in agreement with observation of multiple phases separation in sputtered Cr{sub 2}CoGa films by M. Meinert et al. However, significant phase separation could be suppressed by proper control of growth conditions. We showed that Cr{sub 2}CoGa Heusler phase, rather than Co{sub 2}CrGa phase, constitutes the majority of the sample grown on GaAs(001) at 450 {sup o}C. The measured small spin moment of Cr{sub 2}CoGa is in agreement with predicted HM-FCF nature; however, its Curie temperature is not as high as expected from the theoretical prediction probably due to the off-stoichiometry of Cr{sub 2}CoGa and the existence of the disorders and phase separation.

  11. Magnetotransport in MgO-based magnetic tunnel junctions grown by molecular beam epitaxy (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Andrieu, S., E-mail: stephane.andrieu@univ-lorraine.fr; Bonell, F.; Hauet, T.; Montaigne, F. [Institut Jean Lamour, Nancy University/CNRS, Bd des Aiguillettes, BP239, 54506 Vandoeuvre-lès-Nancy (France); Calmels, L.; Snoeck, E. [CEMES, CNRS and Toulouse University, 29 rue Jeanne Marvig, 31055 Toulouse (France); Lefevre, P.; Bertran, F. [Synchrotron SOLEIL-CNRS, L' Orme des Merisiers, Saint-Aubin, BP48, 91192 Gif-sur-Yvette cedex (France)

    2014-05-07

    The strong impact of molecular beam epitaxy growth and Synchrotron Radiation characterization tools in the understanding of fundamental issues in nanomagnetism and spintronics is illustrated through the example of fully epitaxial MgO-based Magnetic Tunnel Junctions (MTJs). If ab initio calculations predict very high tunnel magnetoresistance (TMR) in such devices, some discrepancy between theory and experiments still exists. The influence of imperfections in real systems has thus to be considered like surface contaminations, structural defects, unexpected electronic states, etc. The influence of possible oxygen contamination at the Fe/MgO(001) interface is thus studied, and is shown to be not so detrimental to TMR as predicted by ab initio calculations. On the contrary, the decrease of dislocations density in the MgO barrier of MTJs using Fe{sub 1−x}V{sub x} electrodes is shown to significantly increase TMR. Finally, unexpected transport properties in Fe{sub 1−X}Co{sub x}/MgO/Fe{sub 1−X}Co{sub x} (001) are presented. With the help of spin and symmetry resolved photoemission and ab initio calculation, the TMR decrease for Co content higher than 25% is shown to come from the existence of an interface state and the shift of the empty Δ1 minority spin state towards the Fermi level.

  12. Bends in nanotubes allow electric spin control and coupling

    DEFF Research Database (Denmark)

    Flensberg, Karsten; Marcus, Charles Masamed

    2010-01-01

    We investigate combined effects of spin-orbit coupling and magnetic field in carbon nanotubes containing one or more bends along their length. We show how bends can be used to provide electrical control of confined spins, while spins confined in straight segments remain insensitive to electric...... fields. Device geometries that allow general rotation of single spins are presented and analyzed. In addition, capacitive coupling along bends provides coherent spin-spin interaction, including between otherwise disconnected nanotubes, completing a universal set of one- and two-qubit gates....

  13. BNL alternating gradient synchrotron with four helical magnets to minimize the losses of the polarized proton beam

    Science.gov (United States)

    Tsoupas, N.; Huang, H.; MacKay, W. W.; Meot, F.; Roser, T.; Trbojevic, D.

    2013-04-01

    The principle of using multiple partial helical magnets to preserve the polarization of the proton beam during its acceleration was applied successfully to the alternating gradient synchrotron (AGS) which currently operates with two partial helical magnets. In this paper we further explore this idea by using four partial helical magnets placed symmetrically in the AGS ring. This provides many advantages over the present setup of the AGS, which uses two partial helical magnets. First, the symmetric placement of the four helical magnets and their relatively lower field of operation allows for better control of the AGS optics with reduced values of the beta functions especially near beam injection and allows both the vertical and horizontal tunes to be placed within the “spin tune gap,” therefore eliminating the horizontal and vertical intrinsic spin resonances of the AGS during the acceleration cycle. Second, it provides a wider spin tune gap. Third, the vertical spin direction during beam injection and extraction is closer to vertical. Although the spin tune gap, which is created with four partial helices, can also be created with a single or two partial helices, the high field strength of a single helical magnet which is required to generate such a spin tune gap makes the use of the single helical magnet impractical, and that of the two helical magnets rather difficult. In this paper we will provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and compare them with those from the present setup of the AGS that uses two partial helical magnets. Although in this paper we specifically discuss the effect of the four partial helices on the AGS, this method which can eliminate simultaneously the vertical and horizontal intrinsic spin resonances is a general method and can be applied to any medium energy synchrotron which operates in similar energy range like the AGS and provides the required space to accommodate the four

  14. (GaMn)As: GaAs-based III?V diluted magnetic semiconductors grown by molecular beam epitaxy

    Science.gov (United States)

    Hayashi, T.; Tanaka, M.; Nishinaga, T.; Shimada, H.; Tsuchiya, H.; Otuka, Y.

    1997-05-01

    We have grown novel III-V diluted magnetic semiconductors, (Ga 1 - xMn x)As, on GaAs substrates by low-temperature molecular beam epitaxy using strong nonequilibrium growth conditions. When the Mn concentration x is relatively low (≲0.08), homogeneous alloy semiconductors, GaMnAs, are grown with zincblende structure and slightly larger lattice constants than that of GaAs, whereas inhomogeneous structures with zincblende GaMnAs (or GaAs) plus hexagonal MnAs are formed when x is relatively high. Magnetization measurements indicate that the homogeneous GaMnAs films have ferromagnetic ordering at low temperature.

  15. Magnet development for the BRF positron emission tomography accelerator

    International Nuclear Information System (INIS)

    A collaboration involving the Biomedical Research Foundation, Science Applications International Corporation, Fermi National Accelerator Laboratory, and the University of Washington is developing an accelerator for producing isotopes for Positron Emission Tomography (PET) scans. The Medium Energy Beam Transport (MEBT) section of this accelerator takes a small beam from a first RFQ acceleration device and matches it into a small 3D-acceptance at a second RFQ section. The beam transport system was designed to prevent beam losses due to emittance growth. The system includes two bending dipoles and seven quadrupoles of three different types. This report contains a brief description of the MEBT magnets and their electric, magnetic and thermal properties. The magnet measurements show that each of the magnets meets the system requirements

  16. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

    CERN Document Server

    Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Sánchez, M Calderón de la Barca; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Leyva, A Davila; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; de Souza, R Derradi; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Don, D M M D Madagodagettige; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen,, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-01-01

    Local parity-odd domains are theorized to form inside a Quark-Gluon-Plasma (QGP) which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect (CME). The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this paper, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy, and tends to vanish by 7.7 GeV. The implications of these results for the CME will be discussed.

  17. Effects of magnetic non-linearities on a stored proton beam and their implications for superconducting storage rings

    International Nuclear Information System (INIS)

    A nonlinear lens may be used to study the effect of high-order multipolar field imperfections on a stored proton beam. Such a nonlinear lens is particulary suitable to simulate field imperfections of the types encountered in coil dominated superconducting magnets. We have studied experimentally at the SPS the effect of high order (5th and 8th) single isolated resonances driven by the nonlinear lens. The width of these resonances is of the order one expects to be caused by field errors in superconducting magnets of the SSC type. The experiment shows that, in absence of tune modulation, these resonances are harmless. Slow crossings of the resonance, on the other hand, have destructive effects on the beam, much more so than fast crossings caused by synchrotron oscillations. In the design of future storage rings, sources of low-frequency tune modulation should be avoided as a way to reduce the harmful effects of high order multipolar field imperfection

  18. Design study of double-layer beam trajectory accelerator based on the Rhodotron structure

    Science.gov (United States)

    Jabbari, Iraj; Poursaleh, Ali Mohammad; Khalafi, Hossein

    2016-08-01

    In this paper, the conceptual design of a new structure of industrial electron accelerator based on the Rhodotron accelerator is presented and its properties are compared with those of Rhodotron-TT200 accelerator. The main goal of this study was to reduce the power of RF system of accelerator at the same output electron beam energy. The main difference between the new accelerator structure with the Rhodotron accelerator is the length of the coaxial cavity that is equal to the wavelength at the resonant frequency. Also two sets of bending magnets were used around the acceleration cavity in two layers. In the new structure, the beam crosses several times in the coaxial cavity by the bending magnets around the cavity at the first layer and then is transferred to the second layer using the central bending magnet. The acceleration process in the second layer is similar to the first layer. Hence, the energy of the electron beam will be doubled. The electrical power consumption of the RF system and magnet system were calculated and simulated for the new accelerator structure and TT200. Comparing the calculated and simulated results of the TT200 with those of experimental results revealed good agreement. The results showed that the overall electrical power consumption of the new accelerator structure was less than that of the TT200 at the same energy and power of the electron beam. As such, the electrical efficiency of the new structure was improved.

  19. The switch interface and the interlock protection of the magnet power system of the beam current transport line

    International Nuclear Information System (INIS)

    The synchrotron radiation facility, constructed by the Hefei National Synchrotron Radiation Laboratory, University of Science and Technology of China, had passed the normal check by the state. The facility will be open to the users inside and outside the country. In this paper, the switch interface and the interlock protection of the magnet power system of the beam current transport line, one of the main components of this facility, are described

  20. Beam energy absolute measurement using K-edge absorption spectrometers

    International Nuclear Information System (INIS)

    A method is presented of absolute energy measurement with an accuracy of triangle Ε ∼ 10-4Εo by direct measurement of the bend angle in a high-precision magnetic dipole using two opposite-direction short (about 2 mm long) high-field-intensity magnets (bar Β dipole much-lt Βshortmag) installed at each end and two K-edge absorption spectrometers. Using these spectrometers and the hard x-ray synchrotron radiation created by the short magnets, a bend angle of 4.5 arc deg for the CEBAF energy bandwidth can be measured with an accuracy of a few units of 10-6 rad, and the main sources of systematic errors are the absolute measurement of the field integral and the determination of the centroid of the synchrotron beam at a wavelength equal to the K-edge absorption of the chosen substance