Sample records for joists beams loose

  1. Loose Canons on Deck

    E-Print Network [OSTI]

    2012-12-24T23:59:59.000Z

    Posted originally on the Archive of Our Own at http://archiveofourown.org/works/592681. Rating: General Audiences Archive Warning: No Archive Warnings Apply Category: Gen Fandom: Mina de Malfois Character: Mina de Malfois - Character, Josh Amos... Additional Tags: Fandom Stats: Published: 2012-12-14 Words: 4215 Loose Canons on Deck by Kadorienne Summary Josh has been flooding fandom with old paper 'zine fics, and Mina is suspected of pseuicide. Notes Thank you to Grey Bard, invaluable humor consultant...

  2. Numerical analysis of heat transfer by conduction and natural convection in loose-fill fiberglass insulation--effects of convection on thermal performance

    SciTech Connect (OSTI)

    Delmas, A.A.; Wilkes, K.E.

    1992-04-01T23:59:59.000Z

    A two-dimensional code for solving equations of convective heat transfer in porous media is used to analyze heat transfer by conduction and convection in the attic insulation configuration. The particular cases treated correspond to loose-fill fiberglass insulation, which is characterized by high porosity and air permeability. The effects of natural convection on the thermal performance of the insulation are analyzed for various densities, permeabilities, and thicknesses of insulation. With convection increasing the total heat transfer through the insulation, the thermal resistance was found to decrease as the temperature difference across the insulating material increases. The predicted results for the thermal resistance are compared with data obtained in the large-scale climate simulator at the Roof Research Center using the attic test module, where the same phenomenon has already been observed. The way the wood joists within the insulation influence the start of convection is studied for differing thermophysical and dynamic properties of the insulating material. The presence of wood joists induces convection at a lower temperature difference.

  3. Correlation properties of loose groups

    SciTech Connect (OSTI)

    Maia, M.A.G.; Da Costa, L.N. (Observatorio Nacional do Brasil, Rio de Janeiro (Brazil))

    1990-02-01T23:59:59.000Z

    The two-point spatial correlation function for loose groups of galaxies is computed, using the recently compiled catalog of groups in the southern hemisphere. It is found that the correlation function for groups has a similar slope to that of galaxies but with a smaller amplitude, confirming an earlier result obtained from a similar analysis of the CfA group catalog. This implies that groups of galaxies are more randomly distributed than galaxies, which may be consistent with the predictions of Kashlinsky (1987) for a gravitational clustering scenario for the formation of large-scale structures. 21 refs.

  4. Adhesive Loose Packings of Small Particles

    E-Print Network [OSTI]

    Wenwei Liu; Shuiqing Li; Adrian Baule; Hernán A. Makse

    2014-10-08T23:59:59.000Z

    We explore adhesive loose packings of dry small spherical particles of micrometer size using 3D discrete-element simulations with adhesive contact mechanics. A dimensionless adhesion parameter ($Ad$) successfully combines the effects of particle velocities, sizes and the work of adhesion, identifying a universal regime of adhesive packings for $Ad>1$. The structural properties of the packings in this regime are well described by an ensemble approach based on a coarse-grained volume function that includes correlations between bulk and contact spheres. Our theoretical and numerical results predict: (i) An equation of state for adhesive loose packings that appears as a continuation from the frictionless random close packing (RCP) point in the jamming phase diagram; (ii) The existence of a maximal loose packing point at the coordination number $Z=2$ and packing fraction $\\phi=1/2^{3}$. Our results highlight that adhesion leads to a universal packing regime at packing fractions much smaller than the random loose packing, which can be described within a statistical mechanical framework. We present a general phase diagram of jammed matter comprising frictionless, frictional, adhesive as well as non-spherical particles, providing a classification of packings in terms of their continuation from the spherical frictionless RCP.

  5. Loose mechanochemical coupling of molecular motors

    E-Print Network [OSTI]

    Yunxin Zhang

    2011-05-05T23:59:59.000Z

    In living cells, molecular motors convert chemical energy into mechanical work. Its thermodynamic energy efficiency, i.e. the ratio of output mechanical work to input chemical energy, is usually high. However, using two-state models, we found the motion of molecular motors is loosely coupled to the chemical cycle. Only part of the input energy can be converted into mechanical work. Others is dissipated into environment during substeps without contributions to the macro scale unidirectional movement.

  6. Marius Stan Returning to Reddit To Tie Up Loose Ends

    Broader source: Energy.gov [DOE]

    Marius Stan, computational scientist and Breaking Bad actor, will be returning to Reddit once again to tie up loose ends by answering questions.

  7. Toward Improved Support for Loosely Coupled Large Scale Simulation Workflows

    SciTech Connect (OSTI)

    Boehm, Swen [ORNL] [ORNL; Elwasif, Wael R [ORNL] [ORNL; Naughton, III, Thomas J [ORNL; Vallee, Geoffroy R [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    High-performance computing (HPC) workloads are increasingly leveraging loosely coupled large scale simula- tions. Unfortunately, most large-scale HPC platforms, including Cray/ALPS environments, are designed for the execution of long-running jobs based on coarse-grained launch capabilities (e.g., one MPI rank per core on all allocated compute nodes). This assumption limits capability-class workload campaigns that require large numbers of discrete or loosely coupled simulations, and where time-to-solution is an untenable pacing issue. This paper describes the challenges related to the support of fine-grained launch capabilities that are necessary for the execution of loosely coupled large scale simulations on Cray/ALPS platforms. More precisely, we present the details of an enhanced runtime system to support this use case, and report on initial results from early testing on systems at Oak Ridge National Laboratory.

  8. Energy conversion by autonomous regulation of chaos: Dynamical mechanism of loose coupling

    E-Print Network [OSTI]

    Kaneko, Kunihiko

    Energy conversion by autonomous regulation of chaos: Dynamical mechanism of loose coupling Naoko which converts injected energy to output directional motion. The output amount is distributed broadly, and thus the coupling between input energy and output motion is loose, as in the experiments. This energy

  9. Stable loosely-coupled-type algorithm for fluid-structure interaction in blood flow

    E-Print Network [OSTI]

    Guidoboni, Giovanna

    Stable loosely-coupled-type algorithm for fluid-structure interaction in blood flow Giovanna Abstract We introduce a novel loosely coupled-type algorithm for fluid-structure interaction between blood. A major application is blood flow in human arteries. Understanding fluid- structure interaction between

  10. Structure of a Loose Dimer: an Intermediate in Nitric Oxide Synthase Assembly

    SciTech Connect (OSTI)

    Pant,K.; Crane, B.

    2005-01-01T23:59:59.000Z

    Cooperativity among ligand binding, subunit association, and protein folding has implications for enzyme regulation as well as protein aggregation events associated with disease. The binding of substrate l-arginine or cofactor tetrahydrobiopterin converts nitric oxide synthases (NOSs) from a 'loose dimer', with an exposed active center and higher sensitivity to proteolysis, to a 'tight dimer' competent for catalysis. The crystallographic structure of the Bacillus subtilis NOS loose dimer shows an altered association state with severely destabilized subdomains. Ligand binding or heme reduction converts loose dimers to tight dimers in solution and crystals. Mutations at key positions in the dimer interface that distinguish prokaryotic from eukaryotic NOSs affect the propensity to form loose dimers. The loose dimer structure indicates that non-native interactions can mediate subunit association in NOS.

  11. Hypertension still a killer on the loose | Windsor Star http://blogs.windsorstar.com/2013/09/04/hypertension-still-a-killer-on-the-loose/[9/5/2013 9:49:50 AM

    E-Print Network [OSTI]

    Cinabro, David

    Hypertension still a killer on the loose | Windsor Star http://blogs.windsorstar.com/2013/09/04/hypertension-still-a-killer-on-the-loose/[9/5/2013 9:49:50 AM] BODY AND HEALTH LIFE / Body and Health Hypertension still a killer on the loose Recent statistics indicate about 20 per cent of the Canadian

  12. Loosely Annotated Bibiolography: recommended by Applied Environmental Decision Analysis researchers (June-July 2011) and

    E-Print Network [OSTI]

    Loosely Annotated Bibiolography: recommended by Applied Environmental Decision Analysis researchers-structured models are even more likely to collapse. Risks and decisions for conservation and environmental management (Burgman and Possingham 2000) Population Viability Analysis (PVA) is a useful tool

  13. Loosely Annotated Bibiolography: recommended by Applied Environmental Decision Analysis researchers (June-July 2011)

    E-Print Network [OSTI]

    Loosely Annotated Bibiolography: recommended by Applied Environmental Decision Analysis researchers to collapse. Risks and decisions for conservation and environmental management (Burgman and Possingham 2000) Population Viability Analysis (PVA) is a useful tool for conservation planning and population management

  14. Play and tolerance : notions of looseness in social and material assemblages

    E-Print Network [OSTI]

    Voorhees, Jeremy, 1978-

    2004-01-01T23:59:59.000Z

    The material scenario provides the most illustrative of entry points into this collection of evidence embodying the difference between play and tolerance. In a material assemblage, the looseness in a joint (expansion, pin, ...

  15. Contributions to the analysis and mitigation of liquefaction in loose sand slopes

    E-Print Network [OSTI]

    Vytiniotis, Antonios

    2012-01-01T23:59:59.000Z

    This research analyzes the vulnerability of loose granular waterfront fills to liquefaction in seismic events and considers the effectiveness of Pre-fabricated Vertical (PV) drain systems in mitigating potential damage. ...

  16. On blind searches for noise dominated signals: a loosely coherent approach

    E-Print Network [OSTI]

    Vladimir Dergachev

    2010-08-23T23:59:59.000Z

    We introduce a "loosely coherent" method for detection of continuous gravitational waves that bridges the gap between semi-coherent and purely coherent methods. Explicit control over accepted families of signals is used to increase sensitivity of power-based statistic while avoiding the high computational costs of conventional matched filters. Several examples as well as a prototype implementation are discussed.

  17. Enhancing inter-organizational resilience by loose coupling concept and complexity paradigm

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Enhancing inter-organizational resilience by loose coupling concept and complexity paradigm Colin into management and organization theories by presenting an inter-organizational resilience model which explains how non-deterministic couplings can enhance inter-organizational resilience. 1 INTRODUCTION To achieve

  18. Results from Tight and Loose Coupled Multiphysics in Nuclear Fuels Performance Simulations using BISON

    SciTech Connect (OSTI)

    S. R. Novascone; B. W. Spencer; D. Andrs; R. L. Williamson; J. D. Hales; D. M. Perez

    2013-05-01T23:59:59.000Z

    The behavior of nuclear fuel in the reactor environment is affected by multiple physics, most notably heat conduction and solid mechanics, which can have a strong influence on each other. To provide credible solutions, a fuel performance simulation code must have the ability to obtain solutions for each of the physics, including coupling between them. Solution strategies for solving systems of coupled equations can be categorized as loosely-coupled, where the individual physics are solved separately, keeping the solutions for the other physics fixed at each iteration, or tightly coupled, where the nonlinear solver simultaneously drives down the residual for each physics, taking into account the coupling between the physics in each nonlinear iteration. In this paper, we compare the performance of loosely and tightly coupled solution algorithms for thermomechanical problems involving coupled thermal and mechanical contact, which is a primary source of interdependence between thermal and mechanical solutions in fuel performance models. The results indicate that loosely-coupled simulations require significantly more nonlinear iterations, and may lead to convergence trouble when the thermal conductivity of the gap is too small. We also apply the tightly coupled solution strategy to a nuclear fuel simulation of an experiment in a test reactor. Studying the results from these simulations indicates that perhaps convergence for either approach may be problem dependent, i.e., there may be problems for which a loose coupled approach converges, where tightly coupled won’t converge and vice versa.

  19. Fusion Induced by Radioactive Ion Beams

    E-Print Network [OSTI]

    J. F. Liang; C. Signorini

    2005-04-26T23:59:59.000Z

    The use of radioactive beams opens a new frontier for fusion studies. The coupling to the continuum can be explored with very loosely bound nuclei. Experiments were performed with beams of nuclei at or near the proton and neutron drip-lines to measure fusion and associated reactions in the vicinity of the Coulomb barrier. In addition, the fusion yield is predicted to be enhanced in reactions involving very neutron-rich unstable nuclei. Experimental measurements were carried out to investigate if it is feasible to use such beams to produce new heavy elements. The current status of these experimental activities is given in this review.

  20. Entrance channel dependence in compound nuclear reactions with loosely bound nuclei

    E-Print Network [OSTI]

    S. Adhikari; C. Samanta; C. Basu; S. Ray; A. Chattaerjee; S. Kailas

    2005-05-13T23:59:59.000Z

    The measurement of light charged particles evaporated from the reaction 6,7Li+6Li has been carried out at extreme backward angle in the energy range 14 - 20 MeV. Calculations from the code ALICE91 show that the symmetry of the target-projectile combination and the choice of level density parameter play important roles in explaining the evaporation spectra for these light particle systems. In above barrier energy region the fusion cross-section is not suppressed for these loosely bound nuclei.

  1. p=constant compression on loose Hostun sand: The case of an anisotropic response

    E-Print Network [OSTI]

    P. Evesque

    2005-07-08T23:59:59.000Z

    Experimental data from axially symmetric compression test at constant mean pressure p on Hostun sand from Flavigny experiments on loose sands are used to study the validity of an "isotropic" modelling at different densities . It is found that the material response is not isotropic even at small deviatoric stress. As an "isotropic" behaviour is found for compression test at constant volume on the same sand, this new result questions the unicity of the trajectory in the classical phase space of soil mechanics (q,p,v), with q being thed deviatoric stress, v the specific volume. This asks whether the space shall be taken larger than 3d or not. Pacs # : 5.40 ; 45.70 ; 62.20 ; 83.70.Fn

  2. Off-resonance frequency operation for power transfer in a loosely coupled air core transformer

    DOE Patents [OSTI]

    Scudiere, Matthew B

    2012-11-13T23:59:59.000Z

    A power transmission system includes a loosely coupled air core transformer having a resonance frequency determined by a product of inductance and capacitance of a primary circuit including a primary coil. A secondary circuit is configured to have a substantially same product of inductance and capacitance. A back EMF generating device (e.g., a battery), which generates a back EMF with power transfer, is attached to the secondary circuit. Once the load power of the back EMF generating device exceeds a certain threshold level, which depends on the system parameters, the power transfer can be achieved at higher transfer efficiency if performed at an operating frequency less than the resonance frequency, which can be from 50% to 95% of the resonance frequency.

  3. Conventional Versus Automated Implantation of Loose Seeds in Prostate Brachytherapy: Analysis of Dosimetric and Clinical Results

    SciTech Connect (OSTI)

    Genebes, Caroline, E-mail: genebes.caroline@claudiusregaud.fr [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France); Filleron, Thomas; Graff, Pierre [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France); Jonca, Frédéric [Department of Urology, Clinique Ambroise Paré, Toulouse (France); Huyghe, Eric; Thoulouzan, Matthieu; Soulie, Michel; Malavaud, Bernard [Department of Urology and Andrology, CHU Rangueil, Toulouse (France); Aziza, Richard; Brun, Thomas; Delannes, Martine; Bachaud, Jean-Marc [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France)

    2013-11-15T23:59:59.000Z

    Purpose: To review the clinical outcome of I-125 permanent prostate brachytherapy (PPB) for low-risk and intermediate-risk prostate cancer and to compare 2 techniques of loose-seed implantation. Methods and Materials: 574 consecutive patients underwent I-125 PPB for low-risk and intermediate-risk prostate cancer between 2000 and 2008. Two successive techniques were used: conventional implantation from 2000 to 2004 and automated implantation (Nucletron, FIRST system) from 2004 to 2008. Dosimetric and biochemical recurrence-free (bNED) survival results were reported and compared for the 2 techniques. Univariate and multivariate analysis researched independent predictors for bNED survival. Results: 419 (73%) and 155 (27%) patients with low-risk and intermediate-risk disease, respectively, were treated (median follow-up time, 69.3 months). The 60-month bNED survival rates were 95.2% and 85.7%, respectively, for patients with low-risk and intermediate-risk disease (P=.04). In univariate analysis, patients treated with automated implantation had worse bNED survival rates than did those treated with conventional implantation (P<.0001). By day 30, patients treated with automated implantation showed lower values of dose delivered to 90% of prostate volume (D90) and volume of prostate receiving 100% of prescribed dose (V100). In multivariate analysis, implantation technique, Gleason score, and V100 on day 30 were independent predictors of recurrence-free status. Grade 3 urethritis and urinary incontinence were observed in 2.6% and 1.6% of the cohort, respectively, with no significant differences between the 2 techniques. No grade 3 proctitis was observed. Conclusion: Satisfactory 60-month bNED survival rates (93.1%) and acceptable toxicity (grade 3 urethritis <3%) were achieved by loose-seed implantation. Automated implantation was associated with worse dosimetric and bNED survival outcomes.

  4. Luminosity and beam-beam

    E-Print Network [OSTI]

    Papotti, G; Trad, G

    We report on observations on luminosity evolution and beam-beam interaction from the 2011 physics run. Extrapolations for 2012 are attempted and a list of desired studies and machine developments is included.

  5. Experimental investigation of mixing in a stratified fluid due to diffusion-driven flows in a loosely-packed particle layer

    E-Print Network [OSTI]

    Etheridge, William B. (William Bruce)

    2007-01-01T23:59:59.000Z

    An experimental study was undertaken to investigate if a loosely-packed particle layer can induce mixing due to diffusion-driven Phillips-Wunsch boundary flows in a quiescent stratified fluid. Diffusion-driven flows can ...

  6. The effect of infrared radiation seed treatments on Ustilago tritici (Pers.) Rostr., the causal organism of loose smut of wheat

    E-Print Network [OSTI]

    Miller, John Wesley

    1963-01-01T23:59:59.000Z

    the roots ~ The seedlings were processed according to the method described by Yiorton (12) for studying loose smut oi barley, with certain modifications. Norton used only grow- ing point tissue, but in this emeriment, scutellar tissue also was examinedo... with the rasor blade, leaving a section about one-quarter to one? 10 half inch long. This section was placed in ~ NOH and boiled for six minutes, another modification of Norton's method. The lower concentration of NaOH and shorter boiling time prevented over...

  7. Reduction in the thermal resistance (R-value) of loose-fill insulation and fiberglass batts due to compression

    SciTech Connect (OSTI)

    Yarbrough, D.W.; Wright, J.H.

    1981-04-01T23:59:59.000Z

    A method is presented for calculating the thickness reduction of loose-fill insulations and fiberglass batts that result from compressive forces exerted by additional insulation. The thickness reduction is accompanied by an increase in density and a reduction in the R value of the compressed layer. Calculations for thermal resistance of two layers of insulation are given. Information in 4 appendices includes: identification of products tested (products from 3 companies); experimental values for thickness as a function of loading; Fortran programs and output; and calculated R values for stacked insulations. (MCW)

  8. Beams 92: Proceedings. Volume 2, Ion beams, electron beams, diagnostics

    SciTech Connect (OSTI)

    Mosher, D.; Cooperstein, G. [eds.] [Naval Research Lab., Washington, DC (United States)] [eds.; Naval Research Lab., Washington, DC (United States)

    1993-12-31T23:59:59.000Z

    This report contains papers on the following topics. Ion beam papers; electron beam papers; and these papers have been indexed separately elsewhere.

  9. Accelerator beam profile analyzer

    DOE Patents [OSTI]

    Godel, Julius B. (Bayport, NY); Guillaume, Marcel (Grivegnee, BE); Lambrecht, Richard M. (East Quogue, NY); Withnell, Ronald (East Setauket, NY)

    1976-01-01T23:59:59.000Z

    A beam profile analyzer employing sector or quadrant plates each servo controlled to outline the edge of a beam.

  10. Beam Status

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMForms About Batteries Batteries An error occurred. TryRing CurrentBeam

  11. Beam History

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWPAlumniComplex historian ...BESFor Users LiveBattling birdBeam

  12. Beam History

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWPAlumniComplex historian ...BESFor Users LiveBattlingBeam

  13. Beam geometry selection using sequential beam addition

    SciTech Connect (OSTI)

    Popple, Richard A., E-mail: rpopple@uabmc.edu; Brezovich, Ivan A.; Fiveash, John B. [Department of Radiation Oncology, The University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, Alabama 35294 (United States)] [Department of Radiation Oncology, The University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, Alabama 35294 (United States)

    2014-05-15T23:59:59.000Z

    Purpose: The selection of optimal beam geometry has been of interest since the inception of conformal radiotherapy. The authors report on sequential beam addition, a simple beam geometry selection method, for intensity modulated radiation therapy. Methods: The sequential beam addition algorithm (SBA) requires definition of an objective function (score) and a set of candidate beam geometries (pool). In the first iteration, the optimal score is determined for each beam in the pool and the beam with the best score selected. In the next iteration, the optimal score is calculated for each beam remaining in the pool combined with the beam selected in the first iteration, and the best scoring beam is selected. The process is repeated until the desired number of beams is reached. The authors selected three treatment sites, breast, lung, and brain, and determined beam arrangements for up to 11 beams from a pool comprised of 25 equiangular transverse beams. For the brain, arrangements were additionally selected from a pool of 22 noncoplanar beams. Scores were determined for geometries comprised equiangular transverse beams (EQA), as well as two tangential beams for the breast case. Results: In all cases, SBA resulted in scores superior to EQA. The breast case had the strongest dependence on beam geometry, for which only the 7-beam EQA geometry had a score better than the two tangential beams, whereas all SBA geometries with more than two beams were superior. In the lung case, EQA and SBA scores monotonically improved with increasing number of beams; however, SBA required fewer beams to achieve scores equivalent to EQA. For the brain case, SBA with a coplanar pool was equivalent to EQA, while the noncoplanar pool resulted in slightly better scores; however, the dose-volume histograms demonstrated that the differences were not clinically significant. Conclusions: For situations in which beam geometry has a significant effect on the objective function, SBA can identify arrangements equivalent to equiangular geometries but using fewer beams. Furthermore, SBA provides the value of the objective function as the number of beams is increased, allowing the planner to select the minimal beam number that achieves the clinical goals. The method is simple to implement and could readily be incorporated into an existing optimization system.

  14. Loose and sketchy rendering

    E-Print Network [OSTI]

    Abna, Tonya

    1999-01-01T23:59:59.000Z

    -photorealistic rendering, traditional pen-and-ink drawing, and graphical user interface design. Past and present researchers in these fields have much to offer in the way of guidelines and methods. Each of these areas is surveyed below. 2. 1 Non-Photorealistic Rendering..., will form a group in the user's perception. 28 fulfil! Figure 2. 11 The Law of Continuity. The indented options are considered by the user to be associated with each other, while the remaining two options are likewise considered to be asso- ciated...

  15. Beam position monitor

    DOE Patents [OSTI]

    Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf

    2003-07-22T23:59:59.000Z

    An apparatus for determining the position of an x-ray beam relative to a desired beam axis. Where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in an a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.

  16. BEAMS3D Neutral Beam Injection Model

    SciTech Connect (OSTI)

    Lazerson, Samuel

    2014-04-14T23:59:59.000Z

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  17. Center for Beam Physics

    E-Print Network [OSTI]

    Chattopadhyay, S.

    2010-01-01T23:59:59.000Z

    interactions, ultra-high intensity lasers, 3D Laser Imagingconcepts, ultra-high intensity lasers, x-ray generation,interests: Ultra-high vacuum, particle beam and laser beam

  18. Center for Beam Physics

    E-Print Network [OSTI]

    Chattopadhyay, S.

    2010-01-01T23:59:59.000Z

    FEL Collaboration: Photocathode/SCRF Collaboration: Two-BeamUniversity on Photocathode/ SCRF technology, LBNL-BNL on

  19. Beam Dynamics for ARIA

    E-Print Network [OSTI]

    Ekdahl, Carl

    2015-01-01T23:59:59.000Z

    Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

  20. LBNL-46223, CBP Note 350 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS IN THE LHC

    E-Print Network [OSTI]

    Furman, Miguel

    LBNL-46223, CBP Note 350 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS IN THE LHC M. A. Furman, W. C. Turner, Center for Beam Physics, LBNL, Berkeley, CA 94720, USA Abstract We present beam-beam simulation of simulations: (a) to as- sess undesirable effects from LBNL's luminosity monitor- ing scheme for the LHC [2

  1. LBNL-45363, CBP Note 333 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS

    E-Print Network [OSTI]

    Furman, Miguel

    LBNL-45363, CBP Note 333 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS Miguel A. Furman, Center for Beam Physics, LBNL, Berkeley, CA 94720 Abstract We present beam-beam simulation results from a strong undesirable effects from LBNL's sweeping lumi- nosity monitoring scheme for the LHC [1], and (b) to assess

  2. Methods of Beam Cooling

    E-Print Network [OSTI]

    Sessler, A. M.

    2008-01-01T23:59:59.000Z

    of Optical Stochastic Cooling", presented at PAC, (1995).1991). Hangst, J. , "Laser Cooling of a Stored Ion Beam - ATheorem and Phase Space Cooling", Proceedings of the

  3. Broad beam ion implanter

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA)

    1996-01-01T23:59:59.000Z

    An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.

  4. Courses on Beam Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    is an incomplete listing of course available for beam physics. United States Particle Accelerator School The US Particle Accelerator School provides educational programs in the...

  5. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, B.E.; Duncan, D.B.

    1994-02-15T23:59:59.000Z

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus is described. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 7 figures.

  6. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, B.E.; Duncan, D.B.

    1993-12-28T23:59:59.000Z

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 11 figures.

  7. First Beam to FACET

    SciTech Connect (OSTI)

    Erickson, R.; Clarke, C.; Colocho, W.; Decker, F.-J.; Hogan, M.; Kalsi, S.; Lipkowitz, N.; Nelson, J.; Phinney, N.; Schuh, P.; Sheppard, J.; Smith, H.; Smith, T.; Stanek, M.; Turner, J.; Warren, J.; Weathersby, S.; Wienands, U.; Wittmer, W.; Woodley, M.; Yocky, G.; /SLAC

    2011-12-13T23:59:59.000Z

    The SLAC 3km linear electron accelerator has been reconfigured to provide a beam of electrons to the new Facility for Advanced Accelerator Experimental Tests (FACET) while simultaneously providing an electron beam to the Linac Coherent Light Source (LCLS). On June 23, 2011, the first electron beam was transported through this new facility. Commissioning of FACET is in progress. On June 23, 2011, an electron beam was successfully transported through the new FACET system to a dump in Sector 20 in the linac tunnel. This was achieved while the last third of the linac, operating from the same control room, but with a separate injector system, was providing an electron beam to the Linac Coherent Light Source (LCLS), demonstrating that concurrent operation of the two facilities is practical. With the initial checkout of the new transport line essentially complete, attention is now turning toward compressing the electron bunches longitudinally and focusing them transversely to support a variety of accelerator science experiments.

  8. STOCHASTIC COOLING OF BUNCHED BEAMS

    E-Print Network [OSTI]

    Bisognano, J.J.

    2010-01-01T23:59:59.000Z

    March 11-13, 1981 STOCHASTIC COOLING OF BUNCHED BEAMS J.J.W-7406-BW-48 STOCHASTIC COOLING OF BUNCHED BEAMS* J.J.longitudinal stochastic cooling of bunched particle beams.

  9. Simulations of beam-beam and beam-wire interactions in RHIC

    SciTech Connect (OSTI)

    Kim, Hyung J.; Sen, Tanaji; /Fermilab; Abreu, Natalia P.; Fischer, Wolfram; /Brookhaven

    2009-02-01T23:59:59.000Z

    The beam-beam interaction is one of the dominant sources of emittance growth and luminosity lifetime deterioration. A current carrying wire has been proposed to compensate long-range beam-beam effects in the LHC and strong localized long-range beam-beam effects are experimentally investigated in the RHIC collider. Tune shift, beam transfer function, and beam loss rate are measured in dedicated experiments. In this paper, they report on simulations to study the effect of beam-wire interactions based on diffusive apertures, beam loss rates, and beam transfer function using a parallelized weak-strong beam simulation code (BBSIMC). The simulation results are compared with measurements performed in RHIC during 2007 and 2008.

  10. Ion beam lithography system

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2005-08-02T23:59:59.000Z

    A maskless plasma-formed ion beam lithography tool provides for patterning of sub-50 nm features on large area flat or curved substrate surfaces. The system is very compact and does not require an accelerator column and electrostatic beam scanning components. The patterns are formed by switching beamlets on or off from a two electrode blanking system with the substrate being scanned mechanically in one dimension. This arrangement can provide a maskless nano-beam lithography tool for economic and high throughput processing.

  11. Development of Fragmented Low-Z Ion Beams for the NA61 Experiment at the CERN SPS

    E-Print Network [OSTI]

    Efthymiopoulos, I; Bohl, T; Breuker, H; Calviani, M; Manglunki, D; Mataguez, S; Maury, S; Valderanis, C; Cornelis, K; Spanggaard, J; Cettour-Cave, S; Gazdzicki, M; Seyboth, P; Guber, F; Ivashkin, A

    2011-01-01T23:59:59.000Z

    The NA61 experiment, aims to study the properties of the onset of deconfinement at low SPS energies and to find signatures of the critical point of strongly interacting matter. A broad range in T-?B phase diagram will be covered by performing an energy (13A-158AGeV/c) and system size (p+p, Be+Be, Ar+Ca, Xe+La) scan. In a first phase, fragmented ion beams of 7Be or 11C produced as secondaries with the same momentum per nucleon when the incident primary Pb-ion beam hits a thin Be target will be used. The H2 beam line that transports the beam to the experiment acts as a double spectrometer which combined with a new thin target (degrader) where fragments loose energy proportional to the square of their charge allows the separation of the wanted A/Z fragments. Thin scintillators and TOF measurement for the low energy points are used as particle identification devices. In this paper results from the first test of the fragmented ion beam done in 2010 will be presented showing that a pure Be beam can be obtained sa...

  12. Coherent beam-beam mode in the LHC

    E-Print Network [OSTI]

    Buffat, X; Giachino, R; Herr, W; Papotti, G; Pieloni, T; White, S

    2014-01-01T23:59:59.000Z

    Observations of single bunch beam-beam coherent modes during dedicated experiments in the LHC are presented. Their role in standard operation for physics is discussed and, in particular, candidates of beam-beam coherent mode driven unstable by the machine impedance are presented.

  13. Focused ion beam system

    DOE Patents [OSTI]

    Leung, K.; Gough, R.A.; Ji, Q.; Lee, Y.Y.

    1999-08-31T23:59:59.000Z

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 {mu}m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 m or less. 13 figs.

  14. Final focus test beam

    SciTech Connect (OSTI)

    Not Available

    1991-03-01T23:59:59.000Z

    This report discusses the following: the Final Focus Test Beam Project; optical design; magnets; instrumentation; magnetic measurement and BPM calibration; mechanical alignment and stabilization; vacuum system; power supplies; control system; radiation shielding and personnel protection; infrastructure; and administration.

  15. Pulsed ion beam source

    DOE Patents [OSTI]

    Greenly, John B. (Lansing, NY)

    1997-01-01T23:59:59.000Z

    An improved pulsed ion beam source having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center.

  16. LHC beam behaviour

    E-Print Network [OSTI]

    Herr, W

    2010-01-01T23:59:59.000Z

    An attempt is made to extract information on the LHC beam behaviour and dynamics from the observations made during the first runs in 2009. Although no systematic studies have been made, some basic properties can be established and in particular the observations in the presence of two beams and in collision are studied. They are analyzed in view of the foreseen runs at higher energy and possible improvements are proposed.

  17. Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development

    SciTech Connect (OSTI)

    Gilpatrick, John D. [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gonzales, Fermin [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2012-05-15T23:59:59.000Z

    The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H{sup -} beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

  18. Photon beam position monitor

    DOE Patents [OSTI]

    Kuzay, T.M.; Shu, D.

    1995-02-07T23:59:59.000Z

    A photon beam position monitor is disclosed for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade ''shadowing''. Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation. 18 figs.

  19. Single element laser beam shaper

    DOE Patents [OSTI]

    Zhang, Shukui (Yorktown, VA); Michelle D. Shinn (Newport News, VA)

    2005-09-13T23:59:59.000Z

    A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

  20. Prompt neutron decay for very loosely coupled delayed critical 38.1-cm-diam uranium (93.2) metal cylinders

    SciTech Connect (OSTI)

    Mihalczo, J.T. [Oak Ridge National Laboratory, TN (United States)

    1996-12-31T23:59:59.000Z

    A delayed critical very loosely coupled configuration of coaxial right circular 38.1-cm-diam, {approximately}7.62-cm-thick uranium (93.15 wt% {sup 235}U) metal cylinders was assembled in 1965 at the Oak Ridge Critical Experiments Facility to study interaction effects for unmoderated and unreflected uranium metal and described in 1996. Each of the two interacting cylinders was carefully adjusted by inverse kinetics rod drop (IKRD) measurements to have the same subcritical reactivity ({approximately} 85{cents}). For these reactivity determinations, each cylinder was alternately and separately assembled to delayed criticality with a small piece of polyethylene reflector present on the top surface. The system was raised to the appropriate power level by the use of a small additional reflector worth {approximately}10{cents} until delayed neutron precursors reached equilibrium. All reflectors were rapidly removed, and the subcriticality was obtained by IKRD interpretational algorithms. Several adjustments of the mass and configuration of each cylinder were required until the configuration of each cylinder had a subcritical reactivity of 85 {cents}. These adjustments were made by small variations in the mass of each of the cylinders so that the mass of the upper cylinder was 163.1 kg and that of the lower cylinder was 162.8 kg. Once each individual cylinder reactivity was adjusted to 85 {cents} subcritical, the distance between the flat surfaces of each of the two cylinders was adjusted to achieve delayed criticality. The delayed critical spacing between cylinders was 1.3 m. At this spacing for delayed criticality, the coupling reactivity exactly compensates for the subcriticality of the individual cylinders. Thus, the coupling reactivity is 85 {cents}, and using a delayed neutron fraction of 0.0066, the coupling reactivity in k units is 0.0056. This paper describes the prompt neutron decay constant measurements for this assembly.

  1. ICFA Beam Dynamics Newsletter

    SciTech Connect (OSTI)

    Ben-Zvi I.; Kuczewski A.; Altinbas, Z.; Beavis, D.; Belomestnykh,; Dai, J. et al

    2012-07-01T23:59:59.000Z

    The Collider-Accelerator Department at Brookhaven National Laboratory is building a high-brightness 500 mA capable Energy Recovery Linac (ERL) as one of its main R&D thrusts towards eRHIC, the polarized electron - hadron collider as an upgrade of the operating RHIC facility. The ERL is in final assembly stages, with injection commisioning starting in October 2012. The objective of this ERL is to serve as a platform for R&D into high current ERL, in particular issues of halo generation and control, Higher-Order Mode (HOM) issues, coherent emissions for the beam and high-brightness, high-power beam generation and preservation. The R&D ERL features a superconducting laser-photocathode RF gun with a high quantum efficiency photoccathode served with a load-lock cathode delivery system, a highly damped 5-cell accelerating cavity, a highly flexible single-pass loop and a comprehensive system of beam instrumentation. In this ICFA Beam Dynamics Newsletter article we will describe the ERL in a degree of detail that is not usually found in regular publications. We will discuss the various systems of the ERL, following the electrons from the photocathode to the beam dump, cover the control system, machine protection etc and summarize with the status of the ERL systems.

  2. Beam Profile Measurement in MTA Beam Line for High Pressure RF Cavity Beam Test

    SciTech Connect (OSTI)

    Jana, M.R.; Bross, A.; Chung, M.; Greer, S.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.; Leonova, M.; Moretti, A.; Popovic, M.; Schwartz, T.; /Fermilab /IIT, Chicago /PDT, Torino

    2012-05-15T23:59:59.000Z

    Recent High Pressure RF (HPRF) cavity experiment at MuCool Test Area (MTA) has used 400 MeV Linac proton beam to study the beam loading effect. When the energetic proton beam passes through the cavity, it ionizes the inside gas and produces the electrons. These electrons consume RF power inside the cavity. Number of electrons produced per cm inside the cavity (at 950 psi Hydrogen gas) per incident proton is {approx} 1200. The measurement of beam position and profile are necessary. MTA is flammable gas (Hydrogen) hazard zone so we have developed a passive beam diagnostic instrument using Chromox-6 scintillation screen and CCD camera. This paper presents quantitative information about beam position and beam profile. Neutral density filter was used to avoid saturation of CCD camera. Image data is filtered and fitted with Gaussian function to compute the beam size. The beam profile obtained from scintillation screen shall be compared with multi-wire beam profile.

  3. Beam Profile Monitor With Accurate Horizontal And Vertical Beam Profiles

    DOE Patents [OSTI]

    Havener, Charles C [Knoxville, TN; Al-Rejoub, Riad [Oak Ridge, TN

    2005-12-26T23:59:59.000Z

    A widely used scanner device that rotates a single helically shaped wire probe in and out of a particle beam at different beamline positions to give a pair of mutually perpendicular beam profiles is modified by the addition of a second wire probe. As a result, a pair of mutually perpendicular beam profiles is obtained at a first beamline position, and a second pair of mutually perpendicular beam profiles is obtained at a second beamline position. The simple modification not only provides more accurate beam profiles, but also provides a measurement of the beam divergence and quality in a single compact device.

  4. Grazing incidence beam expander

    SciTech Connect (OSTI)

    Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

    1985-01-01T23:59:59.000Z

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  5. Beam characteristics of energy-matched flattening filter free beams

    SciTech Connect (OSTI)

    Paynter, D.; Weston, S. J.; Cosgrove, V. P. [St James Institute of Oncology The Leeds Teaching Hospitals NHS Trust, Medical Physics, Leeds LS9 7TF (United Kingdom)] [St James Institute of Oncology The Leeds Teaching Hospitals NHS Trust, Medical Physics, Leeds LS9 7TF (United Kingdom); Evans, J. A. [LIGHT Institute University of Leeds Leeds LS2 9JT, Division of Medical Physics, Leeds (United Kingdom)] [LIGHT Institute University of Leeds Leeds LS2 9JT, Division of Medical Physics, Leeds (United Kingdom); Thwaites, D. I. [LIGHT Institute University of Leeds Leeds LS2 9JT, Division of Medical Physics, Leeds, United Kingdom and Institute of Medical Physics, School of Physics, University of Sydney (Australia)] [LIGHT Institute University of Leeds Leeds LS2 9JT, Division of Medical Physics, Leeds, United Kingdom and Institute of Medical Physics, School of Physics, University of Sydney (Australia)

    2014-05-15T23:59:59.000Z

    Purpose: Flattening filter free (FFF) linear accelerators can increase treatment efficiency and plan quality. There are multiple methods of defining a FFF beam. The Elekta control system supports tuning of the delivered FFF beam energy to enable matching of the percentage depth-dose (PDD) of the flattened beam at 10 cm depth. This is compared to FFF beams where the linac control parameters are identical to those for the flattened beam. All beams were delivered on an Elekta Synergy accelerator with an Agility multi-leaf collimator installed and compared to the standard, flattened beam. The aim of this study is to compare “matched” FFF beams to both “unmatched” FFF beams and flattened beams to determine the benefits of matching beams. Methods: For the three modes of operation 6 MV flattened, 6 MV matched FFF, 6 MV unmatched FFF, 10 MV flattened, 10 MV matched FFF, and 10 MV unmatched FFF beam profiles were obtained using a plotting tank and were measured in steps of 0.1 mm in the penumbral region. Beam penumbra was defined as the distance between the 80% and 20% of the normalized dose when the inflection points of the unflattened and flattened profiles were normalized with the central axis dose of the flattened field set as 100%. PDD data was obtained at field sizes ranging from 3 cm × 3 cm to 40?cm × 40 cm. Radiation protection measurements were additionally performed to determine the head leakage and environmental monitoring through the maze and primary barriers. Results: No significant change is made to the beam penumbra for FFF beams with and without PDD matching, the maximum change in penumbra for a 10 cm × 10 cm field was within the experimental error of the study. The changes in the profile shape with increasing field size are most significant for the matched FFF beam, and both FFF beams showed less profile shape variation with increasing depth when compared to flattened beams, due to consistency in beam energy spectra across the radiation field. The PDDs of the FFF beams showed less variation with field size, the d{sub max} value was deeper for the matched FFF beam than the FFF beam and deeper than the flattened beam for field sizes greater than 5 cm × 5 cm. The head leakage when using the machine in FFF mode is less than half that for a flattened beam, but comparable for both FFF modes. The radiation protection dose-rate measurements show an increase of instantaneous dose-rates when operating the machines in FFF mode but that increase is less than the ratio of MU/min produced by the machine. Conclusions: The matching of a FFF beam to a flattened beam at a depth of 10 cm in water by increasing the FFF beam energy does not reduce any of the reported benefits of FFF beams. Conversely, there are a number of potential benefits resulting from matching the FFF beam; the depth of maximum dose is deeper, the out of field dose is potentially reduced, and the beam quality and penetration more closely resembles the flattened beams currently used in clinical practice, making dose distributions in water more alike. Highlighted in this work is the fact that some conventional specifications and methods for measurement of beam parameters such as penumbra are not relevant and further work is required to address this situation with respect to “matched” FFF beams and to determine methods of measurement that are not reliant on an associated flattened beam.

  6. Observation of Coherent Beam-beam Effects in the LHC

    E-Print Network [OSTI]

    Buffat, X; Giachino, R; Herr, W; Papotti, G; Pieloni, T; Calaga, R; White, S M

    2011-01-01T23:59:59.000Z

    Early collisions in the LHC with a very limited number of bunches with high intensities indicated the presence of coherent beam-beam driven oscillations. Here we discuss the experimental results and compare with the expectations.

  7. Electron beam dynamics for the ISIS bremsstrahlung beam generation system

    E-Print Network [OSTI]

    Block, Robert E. (Robert Edward)

    2011-01-01T23:59:59.000Z

    An electron beam transport system was designed for use in the Bremsstrahlung Beam Generation System of the Integrated Stand-off Inspection System (ISIS). The purpose of this electron transport system was to provide for ...

  8. Heavy Oil Upgrading from Electron Beam (E-Beam) Irradiation 

    E-Print Network [OSTI]

    Yang, Daegil

    2011-02-22T23:59:59.000Z

    hydrocarbons. Second, we studied the energy transfer mechanism of E-Beam upgrading to optimize the process. Third, we conducted a preliminary economic analysis based on energy consumption and compared the economics of E-Beam upgrading with conventional...

  9. Pulsed ion beam source

    DOE Patents [OSTI]

    Greenly, J.B.

    1997-08-12T23:59:59.000Z

    An improved pulsed ion beam source is disclosed having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center. 12 figs.

  10. Colliding beams of light

    E-Print Network [OSTI]

    B. V. Ivanov

    2002-12-28T23:59:59.000Z

    The stationary gravitational field of two identical counter-moving beams of pure radiation is found in full generality. The solution depends on an arbitrary function and a parameter which sets the scale of the energy density. Some of its properties are studied. Previous particular solutions are derived as subcases.

  11. Ion-beam technologies

    SciTech Connect (OSTI)

    Fenske, G.R. [Argonne National Lab., IL (United States)

    1993-01-01T23:59:59.000Z

    This compilation of figures and diagrams reviews processes for depositing diamond/diamond-like carbon films. Processes addressed are chemical vapor deposition (HFCVD, PACVD, etc.), plasma vapor deposition (plasma sputtering, ion beam sputtering, evaporation, etc.), low-energy ion implantation, and hybrid processes (biased sputtering, IBAD, biased HFCVD, etc.). The tribological performance of coatings produced by different means is discussed.

  12. The Cooling of Particle Beams

    E-Print Network [OSTI]

    Sessler, Andrew M.

    2008-01-01T23:59:59.000Z

    67, 15. Hangst, J "Laser Cooling of a Stored Ion Beam - ATheorem an.d Phase Space Cooling", Proceedings of theWorkshop on Beam Cooling and Related Topics, Montreaux, CERN

  13. Hadron beams session-summary

    SciTech Connect (OSTI)

    Terwilliger, K.M. (University of Michigan, Ann Arbor, MI 48109-1120, USA (US))

    1989-05-05T23:59:59.000Z

    The status of presently operating polarized beams at Fermilab, the AGS, and KEK is discussed. Other schemes such as Siberian Snakes and self-polarization of a beam in situ are briefly analyzed.(AIP)

  14. Laser beam pulse formatting method

    DOE Patents [OSTI]

    Daly, T.P.; Moses, E.I.; Patterson, R.W.; Sawicki, R.H.

    1994-08-09T23:59:59.000Z

    A method for formatting a laser beam pulse using one or more delay loops is disclosed. The delay loops have a partially reflective beam splitter and a plurality of highly reflective mirrors arranged such that the laser beam pulse enters into the delay loop through the beam splitter and circulates therein along a delay loop length defined by the mirrors. As the laser beam pulse circulates within the delay loop a portion thereof is emitted upon each completed circuit when the laser beam pulse strikes the beam splitter. The laser beam pulse is thereby formatted into a plurality of sub-pulses. The delay loops are used in combination to produce complex waveforms by combining the sub-pulses using additive waveform synthesis. 8 figs.

  15. Recent advances of strong-strong beam-beam simulation

    SciTech Connect (OSTI)

    Qiang, Ji; Furman, Miguel A.; Ryne, Robert D.; Fischer, Wolfram; Ohmi,Kazuhito

    2004-09-15T23:59:59.000Z

    In this paper, we report on recent advances in strong-strong beam-beam simulation. Numerical methods used in the calculation of the beam-beam forces are reviewed. A new computational method to solve the Poisson equation on nonuniform grid is presented. This method reduces the computational cost by a half compared with the standard FFT based method on uniform grid. It is also more accurate than the standard method for a colliding beam with low transverse aspect ratio. In applications, we present the study of coherent modes with multi-bunch, multi-collision beam-beam interactions at RHIC. We also present the strong-strong simulation of the luminosity evolution at KEKB with and without finite crossing angle.

  16. Metallic beam development for the Facility for Rare Isotope Beam

    SciTech Connect (OSTI)

    Machicoane, Guillaume, E-mail: machicoa@nscl.msu.edu; Cole, Dallas; Leitner, Daniela; Neben, Derek; Tobos, Larry [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)] [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)

    2014-02-15T23:59:59.000Z

    The Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) will accelerate a primary ion beam to energies beyond 200 MeV/u using a superconducting RF linac and will reach a maximum beam power of 400 kW on the fragmentation target. The beam intensity needed from the ECR ion source is expected to be between 0.4 and 0.5 emA for most medium mass to heavy mass elements. Adding to the challenge of reaching the required intensity, an expanded list of primary beams of interest has been established based on the production rate and the number of isotope beams that could be produced with FRIB. We report here on the development done for some of the beam in the list including mercury (natural), molybdenum ({sup 98}Mo), and selenium ({sup 82}Ser)

  17. Results of long-range beam-beam studies - scaling with beam separation and intensity

    E-Print Network [OSTI]

    Assmann, R; Buffat, X; Calaga, R; Giachino, R; Herr, W; Metral, E; Papotti, G; Pieloni, T; Roy, G; Trad, G; Kaltchev, D; CERN. Geneva. ATS Department

    2012-01-01T23:59:59.000Z

    We studied possible limitations due to the long-range beam-beam effects in the LHC. With a large number of bunches and collisions in all interaction points, we have reduced the crossing angles to enhance long-range beam-beam effects to evaluate their influence on dynamic aperture and losses. Different beta* and intensities have been used in two dedicated experiments and allow the test of the expected scaling laws.

  18. Ion beam generating apparatus

    DOE Patents [OSTI]

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); Galvin, James (2 Commodore #276, Emeryville, CA 94608)

    1987-01-01T23:59:59.000Z

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam.

  19. Ion beam generating apparatus

    DOE Patents [OSTI]

    Brown, I.G.; Galvin, J.

    1987-12-22T23:59:59.000Z

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. 10 figs.

  20. Stationary nonlinear Airy beams

    SciTech Connect (OSTI)

    Lotti, A. [Dipartimento di Fisica e Matematica, Universita del'Insubria, Via Valleggio 11, I-22100 Como (Italy); Centre de Physique Theorique, CNRS, Ecole Polytechnique, F-91128 Palaiseau (France); Faccio, D. [Dipartimento di Fisica e Matematica, Universita del'Insubria, Via Valleggio 11, I-22100 Como (Italy); School of Engineering and Physical Sciences, SUPA, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Couairon, A. [Centre de Physique Theorique, CNRS, Ecole Polytechnique, F-91128 Palaiseau (France); Papazoglou, D. G. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1527, GR-71110 Heraklion (Greece); Materials Science and Technology Department, University of Crete, GR-71003 Heraklion (Greece); Panagiotopoulos, P.; Tzortzakis, S. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1527, GR-71110 Heraklion (Greece); Abdollahpour, D. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1527, GR-71110 Heraklion (Greece); Physics Department, University of Crete, GR-71003 Heraklion (Greece)

    2011-08-15T23:59:59.000Z

    We demonstrate the existence of an additional class of stationary accelerating Airy wave forms that exist in the presence of third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations and experiments, in agreement with the analytical model, highlight how these stationary solutions sustain the nonlinear evolution of Airy beams. The generic nature of the Airy solution allows extension of these results to other settings, and a variety of applications are suggested.

  1. Axion beams at HERA?

    E-Print Network [OSTI]

    K. Piotrzkowski

    2007-01-09T23:59:59.000Z

    If the recently observed anomaly in the PVLAS experiment is due to the axion, then the powerful beams of synchrotron photons, propagating through high magnetic field of the HERA beamline, become strong axion sources. This gives a unique opportunity of detection of the axion-photon interactions by installing a small detector in the HERA tunnel, and to corroborate the axion hypothesis within a few days of running.

  2. Understanding the Poor Resolution from Test Beam RunUnderstanding the Poor Resolution from Test Beam Run 2004 Straw Test beam results2004 Straw Test beam results

    E-Print Network [OSTI]

    1 Understanding the Poor Resolution from Test Beam RunUnderstanding the Poor Resolution from Test Beam Run aah #12;2 2004 Straw Test beam results2004 Straw Test beam results ! Doc # 3308 v#3 by A. Ledovskoy " Using Data from 2004 Test Beam " Used "triplet" method for beam nominally perpendicular to Straw

  3. Plasma-beam traps and radiofrequency quadrupole beam coolers

    SciTech Connect (OSTI)

    Maggiore, M., E-mail: mario.maggiore@lnl.infn.it; Cavenago, M.; Comunian, M.; Chirulotto, F.; Galatà, A.; De Lazzari, M.; Porcellato, A. M.; Roncolato, C.; Stark, S. [INFN-LNL, viale dell’Università 2, 35020 Legnaro (Italy)] [INFN-LNL, viale dell’Università 2, 35020 Legnaro (Italy); Caruso, A.; Longhitano, A. [INFN-LNS, via S. Sofia 54, 95123 Catania (Italy)] [INFN-LNS, via S. Sofia 54, 95123 Catania (Italy); Cavaliere, F.; Maero, G.; Paroli, B.; Pozzoli, R.; Romé, M. [INFN Sezione di Milano and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)] [INFN Sezione di Milano and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)

    2014-02-15T23:59:59.000Z

    Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented.

  4. Observations of beam-beam effects at the LHC

    E-Print Network [OSTI]

    Papotti, G; Herr, W; Giachino, R; Pieloni, T

    2014-01-01T23:59:59.000Z

    This paper introduces a list of observations related to the beam-beam interaction that were collected over the first years of LHC proton physics operation (2010-12). Beam-beam related effects not only have been extensively observed and recorded, but have also shaped the operation of the LHC for high-intensity proton running in a number of ways: the construction of the filling scheme, the choice of luminosity levelling techniques, measures to mitigate instabilities, and the choice of settings for improving performance (e.g. to reduce losses), among others.

  5. Precision Absolute Beam Current Measurement of Low Power Electron Beam

    SciTech Connect (OSTI)

    Ali, M. M.; Bevins, M. E.; Degtiarenko, P.; Freyberger, A.; Krafft, G. A.

    2012-11-01T23:59:59.000Z

    Precise measurements of low power CW electron beam current for the Jefferson Lab Nuclear Physics program have been performed using a Tungsten calorimeter. This paper describes the rationale for the choice of the calorimeter technique, as well as the design and calibration of the device. The calorimeter is in use presently to provide a 1% absolute current measurement of CW electron beam with 50 to 500 nA of average beam current and 1-3 GeV beam energy. Results from these recent measurements will also be presented.

  6. Neutral Beam Excitation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3, Issue 30 NewNetworks,Beam

  7. Beam characterization by wavefront sensor

    DOE Patents [OSTI]

    Neal, D.R.; Alford, W.J.; Gruetzner, J.K.

    1999-08-10T23:59:59.000Z

    An apparatus and method are disclosed for characterizing an energy beam (such as a laser) with a two-dimensional wavefront sensor, such as a Shack-Hartmann lenslet array. The sensor measures wavefront slope and irradiance of the beam at a single point on the beam and calculates a space-beamwidth product. A detector array such as a charge coupled device camera is preferably employed. 21 figs.

  8. Beam emittance measurements at Fermilab

    SciTech Connect (OSTI)

    Wendt, Manfred; Eddy, Nathan; Hu, Martin; Scarpine, Victor; Syphers, Mike; Tassotto, Gianni; Thurman-Keup, Randy; Yang, Ming-Jen; Zagel, James; /Fermilab

    2008-01-01T23:59:59.000Z

    We give short overview of various beam emittance measurement methods, currently applied at different machine locations for the Run II collider physics program at Fermilab. All these methods are based on beam profile measurements, and we give some examples of the related instrumentation techniques. At the end we introduce a multi-megawatt proton source project, currently under investigation at Fermilab, with respect to the beam instrumentation challenges.

  9. Low energy beta-beams

    E-Print Network [OSTI]

    Cristina Volpe

    2009-11-13T23:59:59.000Z

    The main goal of a beta-beam facility is to determine the possible existence of CP violation in the lepton sector, the value of the third neutrino mixing angle and the mass hierarchy. Here we argue that a much broader physics case can be covered since the beta-beam concept can also be used to establish a low energy beta-beam facility. We discuss that the availability of neutrino beams in the 100 MeV energy range offers a unique opportunity to perform neutrino scattering experiments of interest for nuclear physics, for the study of fundamental interactions and of core-collapse supernova physics.

  10. First LHC Beams in ATLAS

    E-Print Network [OSTI]

    Krieger, P

    2009-01-01T23:59:59.000Z

    This is a talk on the ATLAS single beam running, to be given on February 9th at the Aspen Winter Conference.

  11. ANL Beams and Applications Seminar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    characterization of the laser and electron beams of the Cornell Energy Recovery Linac Heng Li Cornell University June 18 Interbeam Scattering Studies at CesrTA Michael Ehrlichman...

  12. Broad-band beam buncher

    DOE Patents [OSTI]

    Goldberg, David A. (Walnut Creek, CA); Flood, William S. (Berkeley, CA); Arthur, Allan A. (Martinez, CA); Voelker, Ferdinand (Orinda, CA)

    1986-01-01T23:59:59.000Z

    A broad-band beam buncher is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-band response and the device as a whole designed to effect broad-band beam coupling, so as to minimize variations of the output across the response band.

  13. NEUTRAL-BEAM INJECTION

    SciTech Connect (OSTI)

    Kunkel, W.B.

    1980-06-01T23:59:59.000Z

    The emphasis in the preceding chapters has been on magnetic confinement of high temperature plasmas. The question of production and heating of such plasmas has been dealt with relatively more briefly. It should not be inferred, however, that these matters must therefore be either trivial or unimportant. A review of the history reveals that in the early days all these aspects of the controlled fusion problem were considered to be on a par, and were tackled simultaneously and with equal vigor. Only the confinement problem turned out to be much more complex than initially anticipated, and richer in challenge to the plasma physicist than the questions of plasma production and heating. On the other hand, the properties of high-temperature plasmas and plasma confinement can only be studied experimentally after the problems of production and of heating to adequate temperatures are solved. It is the purpose of this and the next chapter to supplement the preceding discussions with more detail on two important subjects: neutral-beam injection and radio-frequency heating. These are the major contenders for heating in present and future tokamak and mirror fusion experiments, and even in several proposed reactors. For neutral beams we emphasize here the technology involved, which has undergone a rather remarkable development. The physics of particle and energy deposition in the plasma, and the discussion of the resulting effects on the confined plasma, have been included in previous chapters, and some experimental results are quoted there. Other heating processes of relevance to fusion are mentioned elsewhere in this book, in connection with the experiments where they are used: i.e. ohmic heating, adiabatic compression heating, and alpha-particle heating in Chapter 3 by H.P. Furth; more ohmic heating in Chapter 7, and shock-implosion heating, laser heating, and relativistic-electron beam heating in Chapter 8, both by W. E. Quinn. These methods are relatively straightforward in their physics and their technology, or in any case they are considered to be adequately covered by these other authors.

  14. Laser acceleration of ion beams

    E-Print Network [OSTI]

    I. A. Egorova; A. V. Filatov; A. V. Prozorkevich; S. A. Smolyansky; D. B. Blaschke; M. Chubaryan

    2007-02-01T23:59:59.000Z

    We consider methods of charged particle acceleration by means of high-intensity lasers. As an application we discuss a laser booster for heavy ion beams provided, e.g. by the Dubna nuclotron. Simple estimates show that a cascade of crossed laser beams would be necessary to provide additional acceleration to gold ions of the order of GeV/nucleon.

  15. Head-on beam-beam collisions with high intensities and long range beam-beam studies in the LHC

    E-Print Network [OSTI]

    Albert, M; Assmann, R; Buffat, X; Calaga, R; Cornelis, K; Fitterer, M; Giachino, R; Herr, W; Miyamoto, R; Norman, L; Papotti, G; Pieloni, T; Ponce, L; Redaelli, S; Schaumann, M; Trad, G; Wollmann, D

    2011-01-01T23:59:59.000Z

    In two experiments we studied possible limitations due to the beam-beam effects in the LHC. In the first experiment we collided high intensity bunches head-on to explore the region for high luminosity collisions. In the second test we reduced the crossing angle in the presence of long range encounters to increase their effects.

  16. Toward automated beam optics control

    SciTech Connect (OSTI)

    Silbar, R.R.; Schultz, D.E.

    1987-01-01T23:59:59.000Z

    We have begun a program aiming toward automatic control of charged-particle beam optics using artificial intelligence programming techniques. In developing our prototype, we are working with LISP machines and the KEE expert system shell. Our first goal was to develop a ''mouseable'' representation of a typical beam line. This responds actively to changes entered from the mouse or keyboard, giving an updated display of the beam line itself, its optical properties, and the instrumentation and control devices as seen by the operater. We have incorporated TRANSPORT, written in Fortran but running as a callable procedure in the LISP environment, for simulation of the beam-line optics. This paper describes the experience gained in meeting our first goal and discusses plans to extend the work so that it is usable, in realtime, on an operating beam line. 11 refs.

  17. Delivering High IntensityDelivering High Intensity Proton Beam:Proton Beam

    E-Print Network [OSTI]

    McDonald, Kirk

    11 Delivering High IntensityDelivering High Intensity Proton Beam:Proton Beam: Lessons for the NextFACT08NuFACT08 ­­ 4 July4 July S. ChildressS. Childress ­­ Proton BeamsProton Beams 22 Presentation OutlinePresentation Outline Key Proton Beam ConsiderationsKey Proton Beam Considerations The First

  18. Laser beam alignment apparatus and method

    DOE Patents [OSTI]

    Gruhn, Charles R. (Martinez, CA); Hammond, Robert B. (Los Alamos, NM)

    1981-01-01T23:59:59.000Z

    The disclosure relates to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  19. Electrostatic wire stabilizing a charged particle beam

    DOE Patents [OSTI]

    Prono, D.S.; Caporaso, G.J.; Briggs, R.J.

    1983-03-21T23:59:59.000Z

    In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

  20. MEASUREMENT OF BEAM CHARACTERISTICS FOR PHOTO- ELECTRON BEAM...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    electron beam is expected to be used in a wide field, such as X-ray generation by inverse Compton scattering, pulse radiolysis, etc. The laser driven photo cathode rf gun system is...

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

    DOE Patents [OSTI]

    Elmer, J.W.; O`Brien, D.W.

    1996-07-09T23:59:59.000Z

    An apparatus and method are disclosed 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 1,000 {micro}m (1 mm or larger), compared to the 250 {micro}m diameter of laser drilling. 5 figs.

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

    DOE Patents [OSTI]

    Elmer, John W. (Pleasanton, CA); O'Brien, Dennis W. (Livermore, CA)

    1996-01-01T23:59:59.000Z

    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.

  3. Alight a beam and beaming light: A theme with variations

    SciTech Connect (OSTI)

    Chattopadhyay, S. [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California94720 (United States)] [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California94720 (United States)

    1998-05-01T23:59:59.000Z

    The interaction of light (coherent and incoherent) with charged particle beams is explored in various configurations: incoherent scattering of coherent light (laser) from an incoherent particle beam (high temperature), coherent scattering of coherent light (laser) from a {open_quotes}cold{close_quotes} (bunched) beam, femtosecond generation of particle and light beams via {open_quotes}optical slicing{close_quotes} and Thomson/Compton scattering techniques, etc. The domains of ultrashort temporal duration (femtoseconds) as well as ultrashort wavelengths (x rays and shorter), with varying degrees of coherence, are explored. The relevance to a few critical areas of research in the natural sciences, e.g., ultrafast material, chemical and biological processes, protein folding, particle phase space cooling, etc. are touched upon. All the processes discussed involve proper interpretation and understanding of coherent states of matter and radiation, as well as the quality and quantity of information and energy embedded in them. {copyright} {ital 1998 American Institute of Physics.}

  4. Thermal stresses in laminated beams

    E-Print Network [OSTI]

    Marcano, Victor Manuel

    1983-01-01T23:59:59.000Z

    Stresses Acting on a Section of the Laminated Beam -------- 15 5. Loading Geometry and Material Characteristics of the Test Problem 21 6. Simply-Supported Beam with a Sinusoidal Load--------- 30 7. Shear Stress Distribution for a Simply- Supported... 24. Normal Stress Distribution for a Cantilever Laminated Beam, T-Z sinzx/L --------------- 58 m. i 25. Axial Stress Distribution for a Cantilever Laminated Bearq, T-T (2z/8+1) 2 mi 27. Normal Stress Distribution for ("/L) ? ---- 6O 2 a...

  5. Thermal stresses in laminated beams 

    E-Print Network [OSTI]

    Marcano, Victor Manuel

    1983-01-01T23:59:59.000Z

    Stresses Acting on a Section of the Laminated Beam -------- 15 5. Loading Geometry and Material Characteristics of the Test Problem 21 6. Simply-Supported Beam with a Sinusoidal Load--------- 30 7. Shear Stress Distribution for a Simply- Supported... 24. Normal Stress Distribution for a Cantilever Laminated Beam, T-Z sinzx/L --------------- 58 m. i 25. Axial Stress Distribution for a Cantilever Laminated Bearq, T-T (2z/8+1) 2 mi 27. Normal Stress Distribution for ("/L) ? ---- 6O 2 a...

  6. Circular, confined distribution for charged particle beams

    DOE Patents [OSTI]

    Garnett, R.W.; Dobelbower, M.C.

    1995-11-21T23:59:59.000Z

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location. 26 figs.

  7. Circular, confined distribution for charged particle beams

    DOE Patents [OSTI]

    Garnett, Robert W. (Los Alamos, NM); Dobelbower, M. Christian (Toledo, OH)

    1995-01-01T23:59:59.000Z

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location.

  8. Confined energy distribution for charged particle beams

    DOE Patents [OSTI]

    Jason, Andrew J. (Los Alamos, NM); Blind, Barbara (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

  9. STOCHASTIC COOLING FOR BUNCHED BEAMS.

    SciTech Connect (OSTI)

    BLASKIEWICZ, M.

    2005-05-16T23:59:59.000Z

    Problems associated with bunched beam stochastic cooling are reviewed. A longitudinal stochastic cooling system for RHIC is under construction and has been partially commissioned. The state of the system and future plans are discussed.

  10. Stability diagram of colliding beams

    E-Print Network [OSTI]

    Buffat, X; Mounet, N; Pieloni, T

    2014-01-01T23:59:59.000Z

    The effect of the beam-beam interactions on the stability of impedance mode is discussed. The detuning is evaluated by the means of single particle tracking in arbitrarily complex collision configurations, including lattice non-linearities, and used to numerically evaluate the dispersion integral. This approach also allows the effect of non-Gaussian distributions to be considered. Distributions modified by the action of external noise are discussed.

  11. Single lens laser beam shaper

    DOE Patents [OSTI]

    Liu, Chuyu (Newport News, VA); Zhang, Shukui (Yorktown, VA)

    2011-10-04T23:59:59.000Z

    A single lens bullet-shaped laser beam shaper capable of redistributing an arbitrary beam profile into any desired output profile comprising a unitary lens comprising: a convex front input surface defining a focal point and a flat output portion at the focal point; and b) a cylindrical core portion having a flat input surface coincident with the flat output portion of the first input portion at the focal point and a convex rear output surface remote from the convex front input surface.

  12. Electron beam diagnostic for profiling high power beams

    DOE Patents [OSTI]

    Elmer, John W. (Danville, CA); Palmer, Todd A. (Livermore, CA); Teruya, Alan T. (Livermore, CA)

    2008-03-25T23:59:59.000Z

    A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

  13. KTeV beam systems design report

    SciTech Connect (OSTI)

    Bocean, V.; Childress, S.; Coleman, R. [and others

    1997-09-01T23:59:59.000Z

    The primary and secondary beams for the KTeV experiments E799-II and E832 are discussed. The specifications are presented and justified. The technical details of the implementation of the primary beam transport and stability are detailed. The target, beam dump, and radiation safety issues are discussed. The details of the collimation system for the pair of secondary beams are presented.

  14. Head-on beam-beam tune shifts with high brightness beams in the LHC

    E-Print Network [OSTI]

    Alemany, R; Calaga, R; Cornelis, K; Fitterer, M; Giachino, R; Herr, W; McPherson, A; Miyamoto, R; Papotti, G; Pieloni, T; Redaelli, S; Roncarolo, F; Schaumann, M; Suykerbuyk, R; Trad, G; Paret, S

    2011-01-01T23:59:59.000Z

    In this experiment (fills 1765, 1766) we have collided bunches with highest brightness, i.e. small emittances and high intensities, to explore the achievable beam-beam tune shift for head-on collisions. Different parameters and filling schemes have been used for this experiment and tune shifts above 0.015 have been achieved in single collisions and above 0.030 for two collision points.

  15. eRHIC ring-ring design with head-on beam-beam compensation

    SciTech Connect (OSTI)

    Montag,C.; Blaskiewicz, M.; Pozdeyev, E.; Fischer, W.; MacKay, W. W.

    2009-05-04T23:59:59.000Z

    The luminosity of the eRHIC ring-ring design is limited by the beam-beam effect exerted on the electron beam. Recent simulation studies have shown that the beam-beam limit can be increased by means of an electron lens that compensates the beam-beam effect experienced by the electron beam. This scheme requires proper design of the electron ring, providing the correct betatron phase advance between interaction point and electron lens. We review the performance of the eRHIC ring-ring version and discuss various parameter sets, based on different cooling schemes for the proton/ion beam.

  16. Nufact 2008 The Beta Beam WP Beta beam R&D status

    E-Print Network [OSTI]

    McDonald, Kirk

    Nufact 2008 The Beta Beam WP Nufact 08 1 Beta beam R&D status Elena Wildner, CERN on behalf of the Beta Beam Study Group EURISOL/Euronu #12;Nufact 2008 The Beta Beam WP Nufact08Nufact08 Outline Recall, EURISOL Ion Production Loss Management Improvements New Program, EuroNu 2 #12;Nufact 2008 The Beta Beam WP

  17. Generate Uniform Transverse Distributed Electron Beam along a Beam Line

    E-Print Network [OSTI]

    Jiao, Y

    2015-01-01T23:59:59.000Z

    It has been reported that transverse distribution shaping can help to further enhance the energy extraction efficiency in a terawatt, tapered X-ray free-electron laser. Thus, methods of creating and keeping almost uniform transverse distributed (UTD) beam within undulators are required. This study shows that a UTD electron beam can be generated within evenly distributed drift sections where undulators can be placed, by means of octupoles and particular optics. A concrete design is presented, and numerical simulations are done to verify the proposed method.

  18. Physics Opportunities with Meson Beams

    E-Print Network [OSTI]

    Briscoe, William J; Haberzettl, Helmut; Manley, D Mark; Naruki, Megumi; Strakovsky, Igor I; Swanson, Eric S

    2015-01-01T23:59:59.000Z

    Over the past two decades, meson photo- and electro-production data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even nonexistent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state of-the-art meson-beam facility needs to be constructed. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.

  19. Divergence of optical vortex beams

    E-Print Network [OSTI]

    Reddy, Salla Gangi; Prabhakar, Shashi; Anwar, Ali; Banerji, J; Singh, R P

    2015-01-01T23:59:59.000Z

    We show, both theoretically and experimentally, that the propagation of optical vortices in free space can be analysed by using the width ($w(z)$) of the host Gaussian beam and the inner and outer radii of the vortex beam at the source plane ($z=0$) as defined in \\textit{Optics Letters \\textbf{39,} 4364-4367 (2014)}. We also studied the divergence of vortex beams, considered as the rate of change of inner or outer radius with the propagation distance, and found that it varies with the order in the same way as that of the inner and outer radii at zero propagation distance. These results may be useful in designing optical fibers for orbital angular momentum modes that play a crucial role in quantum communication.

  20. Shimmed electron beam welding process

    DOE Patents [OSTI]

    Feng, Ganjiang (Clifton Park, NY); Nowak, Daniel Anthony (Alplaus, NY); Murphy, John Thomas (Niskayuna, NY)

    2002-01-01T23:59:59.000Z

    A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

  1. Finding beam focus errors automatically

    SciTech Connect (OSTI)

    Lee, M.J.; Clearwater, S.H.; Kleban, S.D.

    1987-01-01T23:59:59.000Z

    An automated method for finding beam focus errors using an optimization program called COMFORT-PLUS. The steps involved in finding the correction factors using COMFORT-PLUS has been used to find the beam focus errors for two damping rings at the SLAC Linear Collider. The program is to be used as an off-line program to analyze actual measured data for any SLC system. A limitation on the application of this procedure is found to be that it depends on the magnitude of the machine errors. Another is that the program is not totally automated since the user must decide a priori where to look for errors. (LEW)

  2. Transverse beam shape measurements of intense proton beams using optical transition radiation

    SciTech Connect (OSTI)

    Scarpine, Victor E.; /Fermilab

    2012-03-01T23:59:59.000Z

    A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

  3. Thermographic calorimetry of the neutral beam injectors heating beams at TJ-II

    SciTech Connect (OSTI)

    Fuentes, C.; Liniers, M.; Guasp, J.; Doncel, J.; Botija, J.; Wolfers, G.; Alonso, J.; Acedo, M.; Sanchez, E.; Marcon, G.; Weber, M.; Carrasco, R.; Sarasola, X.; Zurro, B.; Tera, J. [Laboratorio Nacional de Fusion/Asociacion EURATOM-CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain)

    2006-10-15T23:59:59.000Z

    A new beam diagnostic based on infrared thermography has been developed for the neutral beam injectors of the stellarator TJ-II. A highly anisotropic movable target intercepts the beam at its entrance into the stellarator. The thermal print of the beam is captured with a high resolution infrared camera. The infrared images of the target can be translated, with the appropriate analysis, into power density patterns of the beam. The system is calibrated in situ with two thermocouples adiabatically mounted in the target. The two-dimensional beam power density distribution can be accurately characterized allowing beam optimization with respect to the different parameters involved in the beam formation and transport.

  4. High energy laser beam dump

    DOE Patents [OSTI]

    Halpin, John (Tracy, CA)

    2004-09-14T23:59:59.000Z

    The laser beam dump is positioned in a housing. An absorbing glass plate means is operatively connected to the housing. A heat sync means for extracting heat from the absorbing glass plate means is operatively connected to the housing and operatively connected to the absorbing glass plate means.

  5. Relativistic atomic beam spectroscopy II

    SciTech Connect (OSTI)

    NONE

    1991-12-31T23:59:59.000Z

    We are requesting support for a postdoctoral person to participate in H{sup -} studies at Los Alamos. In addition, we are requesting funding for a state-of-the-art YAG laser system that would allow us to obtain data at three times our present rate with improved beam quality.

  6. Bunch length effects in the beam-beam compensation with an electron lens

    SciTech Connect (OSTI)

    Fischer, W.; Luo, Y.; Montag, C.

    2010-02-25T23:59:59.000Z

    Electron lenses for the head-on beam-beam compensation are under construction at the Relativistic Heavy Ion Collider. The bunch length is of the same order as the {beta}-function at the interaction point, and a proton passing through another proton bunch experiences a substantial phase shift which modifies the beam-beam interaction. We review the effect of the bunch length in the single pass beam-beam interaction, apply the same analysis to a proton passing through a long electron lens, and study the single pass beam-beam compensation with long bunches. We also discuss the beam-beam compensation of the electron beam in an electron-ion collider ring.

  7. antinucleon beams: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    interaction of fields induced by the beam with their environment. Beam current transformers as well as beam position monitors are based on this principle. The signals induced...

  8. automatic beam alignment: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    interaction of fields induced by the beam with their environment. Beam current transformers as well as beam position monitors are based on this principle. The signals induced...

  9. accidental beam loss: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    interaction of fields induced by the beam with their environment. Beam current transformers as well as beam position monitors are based on this principle. The signals induced...

  10. antiparticle beams: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    interaction of fields induced by the beam with their environment. Beam current transformers as well as beam position monitors are based on this principle. The signals induced...

  11. accelerating beam stability: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    particle beams (beam intercepting devices BIDs). For the design of BIDs, the increasing heat load onto these devices due to energetic and focused beams and - in most cases -...

  12. accelerated oxygen-14 beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    particle beams (beam intercepting devices BIDs). For the design of BIDs, the increasing heat load onto these devices due to energetic and focused beams and - in most cases -...

  13. accelerator school beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    particle beams (beam intercepting devices BIDs). For the design of BIDs, the increasing heat load onto these devices due to energetic and focused beams and - in most cases -...

  14. Transport of elliptic intense charged -particle beams

    E-Print Network [OSTI]

    Zhou, J. (Jing), 1978-

    2006-01-01T23:59:59.000Z

    The transport theory of high-intensity elliptic charged-particle beams is presented. In particular, the halo formation and beam loss problem associated with the high space charge and small-aperture structure is addressed, ...

  15. Neutral particle beam sensing and steering

    DOE Patents [OSTI]

    Maier, II, William B. (Los Alamos, NM); Cobb, Donald D. (Los Alamos, NM); Robiscoe, Richard T. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    The direction of a neutral particle beam (NPB) is determined by detecting Ly.alpha. radiation emitted during motional quenching of excited H(2S) atoms in the beam during movement of the atoms through a magnetic field. At least one detector is placed adjacent the beam exit to define an optical axis that intercepts the beam at a viewing angle to include a volume generating a selected number of photons for detection. The detection system includes a lens having an area that is small relative to the NPB area and a pixel array located in the focal plane of the lens. The lens viewing angle and area pixel array are selected to optimize the beam tilt sensitivity. In one embodiment, two detectors are placed coplanar with the beam axis to generate a difference signal that is insensitive to beam variations other than beam tilt.

  16. On Gaussian Beams Described by Jacobi's Equation

    E-Print Network [OSTI]

    Smith, Steven T.

    Gaussian beams describe the amplitude and phase of rays and are widely used to model acoustic propagation. This paper describes four new results in the theory of Gaussian beams. (1) A new version of the ?ervený equations ...

  17. Autogenerator of beams of charged particles

    DOE Patents [OSTI]

    Adler, R.J.; Mazarakis, M.G.; Miller, R.M.; Shope, S.L.; Smith, D.L.

    1983-10-31T23:59:59.000Z

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  18. Autogenerator of beams of charged particles

    DOE Patents [OSTI]

    Adler, Richard J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Miller, Robert B. (Albuquerque, NM); Shope, Steven L. (Albuquerque, NM); Smith, David L. (Albuquerque, NM)

    1986-01-01T23:59:59.000Z

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  19. Maskless, resistless ion beam lithography

    SciTech Connect (OSTI)

    Ji, Qing

    2003-03-10T23:59:59.000Z

    As the dimensions of semiconductor devices are scaled down, in order to achieve higher levels of integration, optical lithography will no longer be sufficient for the needs of the semiconductor industry. Alternative next-generation lithography (NGL) approaches, such as extreme ultra-violet (EUV), X-ray, electron-beam, and ion projection lithography face some challenging issues with complicated mask technology and low throughput. Among the four major alternative NGL approaches, ion beam lithography is the only one that can provide both maskless and resistless patterning. As such, it can potentially make nano-fabrication much simpler. This thesis investigates a focused ion beam system for maskless, resistless patterning that can be made practical for high-volume production. In order to achieve maskless, resistless patterning, the ion source must be able to produce a variety of ion species. The compact FIB system being developed uses a multicusp plasma ion source, which can generate ion beams of various elements, such as O{sub 2}{sup +}, BF{sub 2}{sup +}, P{sup +} etc., for surface modification and doping applications. With optimized source condition, around 85% of BF{sub 2}{sup +}, over 90% of O{sub 2}{sup +} and P{sup +} have been achieved. The brightness of the multicusp-plasma ion source is a key issue for its application to maskless ion beam lithography. It can be substantially improved by optimizing the source configuration and extractor geometry. Measured brightness of 2 keV He{sup +} beam is as high as 440 A/cm{sup 2} {center_dot} Sr, which represents a 30x improvement over prior work. Direct patterning of Si thin film using a focused O{sub 2}{sup +} ion beam has been investigated. A thin surface oxide film can be selectively formed using 3 keV O{sub 2}{sup +} ions with the dose of 10{sup 15} cm{sup -2}. The oxide can then serve as a hard mask for patterning of the Si film. The process flow and the experimental results for directly patterned poly-Si features are presented. The formation of shallow pn-junctions in bulk silicon wafers by scanning focused P{sup +} beam implantation at 5 keV is also presented. With implantation dose of around 10{sup 16} cm{sup -2}, the electron concentration is about 2.5 x 10{sup 18} cm{sup -3} and electron mobility is around 200 cm{sup 2}/V{center_dot}s. To demonstrate the suitability of scanning FIB lithography for the manufacture of integrated circuit devices, SOI MOSFET fabrication using the maskless, resistless ion beam lithography is demonstrated. An array of microcolumns can be built by stacking multi-aperture electrode and insulator layers. Because the multicusp plasma source can achieve uniform ion density over a large area, it can be used in conjunction with the array of microcolumns, for massively parallel FIB processing to achieve reasonable exposure throughput.

  20. High Gradient Two-Beam Electron Accelerator

    SciTech Connect (OSTI)

    Jiang, Y. [Beam Physics Laboratory, Yale University, 272 Whitney Ave., New Haven, CT 06511 (United States); Kazakov, S. Yu. [Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States); Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Kuzikov, S. V. [Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States); Institute of Applied Physics, Nizhny Novgorod, 603600 (Russian Federation); Hirshfield, J. L. [Beam Physics Laboratory, Yale University, 272 Whitney Ave., New Haven, CT 06511 (United States); Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States)

    2010-11-04T23:59:59.000Z

    A high-gradient two-beam electron accelerator structure using detuned cavities is described. A self-consistent theory based on a circuit model is presented to calculate idealized acceleration gradient, transformer ratio, and efficiency for energy transfer from the drive beam to the accelerated beam. Experimental efforts are being carried out to demonstrate this acceleration concept.

  1. Laser Telecommunication timeLaser beam

    E-Print Network [OSTI]

    La Rosa, Andres H.

    Laser Telecommunication Experiment Laser time Laser beam intensity timeLaser beam Laser battery Laser connected to a circuit without a modulator. Bottom graph illustrates what happen when a modulating signal is superimposed to the DC voltage driving the laser Laser beam intensity DC Input voltage DC

  2. Nondestructive Damage Detection in General Beams 

    E-Print Network [OSTI]

    Dincal, Selcuk

    2010-12-08T23:59:59.000Z

    Representation of the First Damage Case on the Finite Element Mesh of the Slender Beam ...................................................... 41 Figure 3.12 Schematic Representation of the Second Damage Case on the Finite Element Mesh... of the Slender Beam ...................................................... 42 Figure 3.13 Schematic Representation of the Third Damage Case on the Finite Element Mesh of the Slender Beam ...................................................... 44...

  3. JET neutral beam power upgrade Introduction

    E-Print Network [OSTI]

    JET neutral beam power upgrade Introduction A tokamak is a complex assembly, a system of systems the challenging requirements that fusion demands. The neutral beam heating system and its upgrade for the JET systems) are the main plasma heating scheme on fusion devices such as JET and ITER. The JET neutral beam

  4. Beam heat load in superconducting wigglers

    E-Print Network [OSTI]

    Casalbuoni, S

    2013-01-01T23:59:59.000Z

    The beam heat load is a fundamental input parameter for the design of superconducting wigglers since it is needed to specify the cooling power. In this presentation I will review the possible beam heat load sources and the measurements of beam heat load performed and planned onto the cold vacuum chambers installed at different synchrotron light sources.

  5. Lateral stability of long precast concrete beams

    E-Print Network [OSTI]

    Burgoyne, Chris

    buckling L length of beam vx lateral de¯ection measured in the minor- axis direction (which rotates with yLateral stability of long precast concrete beams T. J. Stratford, BA, BEng, and C. J. Burgoyne, BA, making them more susceptible to buckling failure. This paper shows that once the beam is positioned

  6. Results of long range beam-beam studies and observations during operation in the LHC

    E-Print Network [OSTI]

    Alemany, R; Buffat, X; Calaga, R; Fitterer, M; Giachino, R; Hemelsoet, GH; Herr, W; Papotti, G; Pieloni, T; Poyer, M; Schaumann, M; Trad, G; Wollmann, D

    2011-01-01T23:59:59.000Z

    We studied possible limitations due to the long range beam-beam effects in the LHC. With a larger number of bunches and collisions in all interaction points, we have reduced the crossing angles to enhance long range beam-beam effects to evaluate their influence on dynamic aperture and losses. Experience from operation with reduced separation was analysed and provides additional evidence.

  7. Electron beam diagnostic for space charge measurement of an ion beam

    SciTech Connect (OSTI)

    Roy, Prabir K.; Yu, Simon S.; Henestroza, Enrique; Eylon, Shmuel; Shuman, Derek B.; Ludvig, Jozsef; Bieniosek, Frank M.; Waldron, William L.; Greenway, Wayne G.; Vanecek, David L.; Hannink, Ryan; Amezcua, Monserrat

    2004-09-25T23:59:59.000Z

    A non-perturbing electron beam diagnostic system for measuring the charge distribution of an ion beam is developed for Heavy Ion Fusion (HIF) beam physics studies. Conventional diagnostics require temporary insertion of sensors into the beam, but such diagnostics stop the beam, or significantly alter its properties. In this diagnostic a low energy, low current electron beam is swept transversely across the ion beam; the measured electron beam deflection is used to infer the charge density profile of the ion beam. The initial application of this diagnostic is to the Neutralized Transport Experiment (NTX), which is exploring the physics of space-charge-dominated beam focusing onto a small spot using a neutralizing plasma. Design and development of this diagnostic and performance with the NTX ion beamline is presented.

  8. Stability of Single Particle Motion with Head-On Beam-Beam Compensation in the RHIC

    SciTech Connect (OSTI)

    Luo,Y.; Fischer, W.; Abreu, N.

    2008-05-01T23:59:59.000Z

    To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in the polarized proton run in the Relativistic Heavy Ion Collider (RHIC), we proposed a low energy electron beam with a Gaussian transverse profiles to collide head-on with the proton beam. In this article, with a weak-strong beam-beam interaction model, we investigate the stability of single particle motion in the presence of head-on beam-beam compensation. Tune footprints, tune diffusion, Lyapunov exponents, and 10{sup 6} turn dynamic apertures are calculated and compared between the cases without and with beam-beam compensation. A tune scan is performed and the possibility of increasing the bunch intensity is studied. The cause of tune footprint foldings is discussed, and the tune diffusion and Lyapunov exponent analysis are compared.

  9. Summary of session 3 on synchrotron radiation and beam dynamics

    SciTech Connect (OSTI)

    Shiltsev, V.; /Fermilab; Metral, E.; /CERN

    2010-12-01T23:59:59.000Z

    We summarize presentations, discussions and general conclusions of the Workshop session on 'Beam Dynamics Issues'. Major subjects include effects due to synchrotron radiation (SR), cryogenic loads, electron cloud, impedances, intra-beam scattering (IBS) and beam-beam interactions.

  10. Beam intensity upgrade at Fermilab

    SciTech Connect (OSTI)

    Marchionni, A.; /Fermilab

    2006-07-01T23:59:59.000Z

    The performance of the Fermilab proton accelerator complex is reviewed. The coming into operation of the NuMI neutrino line and the implementation of slip-stacking to increase the anti-proton production rate has pushed the total beam intensity in the Main Injector up to {approx} 3 x 10{sup 13} protons/pulse. A maximum beam power of 270 kW has been delivered on the NuMI target during the first year of operation. A plan is in place to increase it to 350 kW, in parallel with the operation of the Collider program. As more machines of the Fermilab complex become available with the termination of the Collider operation, a set of upgrades are being planned to reach first 700 kW and then 1.2 MW by reducing the Main Injector cycle time and by implementing proton stacking.

  11. Oxygen ion-beam microlithography

    DOE Patents [OSTI]

    Tsuo, Y. Simon (Lakewood, CO)

    1991-01-01T23:59:59.000Z

    A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used.

  12. Oxygen ion-beam microlithography

    DOE Patents [OSTI]

    Tsuo, Y.S.

    1991-08-20T23:59:59.000Z

    A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used. 5 figures.

  13. The MICE Muon Beam Line

    SciTech Connect (OSTI)

    Apollonio, Marco [High Energy Physics Group, Department of Physics, Imperial College London SW7 2AZ (United Kingdom)

    2011-10-06T23:59:59.000Z

    In the Muon Ionization Cooling Experiment (MICE) at RAL, muons are produced and transported in a dedicated beam line connecting the production point (target) to the cooling channel. We discuss the main features of the beamline, meant to provide muons with momenta between 140 MeV/c and 240 MeV/c and emittances up to 10 mm rad, which is accomplished by means of a diffuser. Matching procedures to the MICE cooling channel are also described. In summer 2010 we performed an intense data taking campaign to finalize the calibration of the MICE Particle Identification (PID) detectors and the understanding of the beam line, which completes the STEPI phase of MICE. We highlight the main results from these data.

  14. Neutron beam testing of triblades

    SciTech Connect (OSTI)

    Michalak, Sarah E [Los Alamos National Laboratory; Du Bois, Andrew J [Los Alamos National Laboratory; Storlie, Curtis B [Los Alamos National Laboratory; Rust, William N [Los Alamos National Laboratory; Du Bois, David H [Los Alamos National Laboratory; Modl, David G [Los Alamos National Laboratory; Quinn, Heather M [Los Alamos National Laboratory; Blanchard, Sean P [Los Alamos National Laboratory; Manuzzato, Andrea [UNIV DEGLI STUDI DI PADOVA ITALY

    2010-12-16T23:59:59.000Z

    Four IBM Triblades were tested in the Irradiation of Chips and Electronics facility at the Los Alamos Neutron Science Center. Triblades include two dual-core Opteron processors and four PowerXCell 8i (Cell) processors. The Triblades were tested in their field configuration while running different applications, with the beam aimed at the Cell processor or the Opteron running the application. Testing focused on the Cell processors, which were tested while running five different applications and an idle condition. While neither application nor Triblade was statistically important in predicting the hazard rate, the hazard rate when the beam was aimed at the Opterons was significantly higher than when it was aimed at the Cell processors. In addition, four Cell blades (one in each Triblade) suffered voltage shorts, leading to their inoperability. The hardware tested is the same as that in the Roadrunner supercomputer.

  15. Fresnel diffraction patterns as accelerating beams

    E-Print Network [OSTI]

    Zhang, Yiqi; Zheng, Huaibin; Wu, Zhenkun; Li, Yuanyuan; Lu, Keqing; Zhang, Yanpeng

    2013-01-01T23:59:59.000Z

    We demonstrate that beams originating from Fresnel diffraction patterns are self-accelerating in free space. In addition to accelerating and self-healing, they also exhibit parabolic deceleration property, which is in stark contrast to other accelerating beams. We find that the trajectory of Fresnel paraxial accelerating beams is similar to that of nonparaxial Weber beams. Decelerating and accelerating regions are separated by a critical propagation distance, at which no acceleration is present. During deceleration, the Fresnel diffraction beams undergo self-smoothing, in which oscillations of the diffracted waves gradually focus and smooth out at the critical distance.

  16. Beam Cooling with ionisation losses

    E-Print Network [OSTI]

    C. Rubbia; A. Ferrari; Y. Kadi; V. Vlachoudis

    2006-02-03T23:59:59.000Z

    A novel type of particle "cooling", called Ionization Cooling, is applicable to slow (v of the order of 0.1c) ions stored in a small ring. The many traversals through a thin foil enhance the nuclear reaction probability, in a steady configuration in which ionisation losses are recovered at each turn by a RF-cavity. For a uniform target "foil" the longitudinal momentum spread diverges exponentially since faster (slower) particles ionise less (more) than the average. In order to "cool" also longitudinally, a chromaticity has to be introduced with a wedge shaped "foil". Multiple scattering and straggling are then "cooled" in all three dimensions, with a method similar to the one of synchrotron cooling, but valid for low energy ions. Particles then stably circulate in the beam indefinitely, until they undergo for instance nuclear processes in the thin target foil. This new method is under consideration for the nuclear production of a few MeV/A ion beams. Simple reactions, for instance Li 7 + D Li 8 + p, are more favourably exploited with the heavier ion colliding against a gas-jet D2 target. Kinematics is generally very favourable, with emission angles in a narrow angular cone and a relatively concentrated outgoing energy spectrum which allows an efficient collection as a neutral gas in a tiny volume with a technology at high temperatures perfected at ISOLDE. It is however of a much more general applicability. The method appears capable of producing a "table top" storage ring with an accumulation rate in excess of 10**14 Li-8 radioactive ion/s for possible use for radioactive beams for physics studies (for example for beta-beams) or for therapy.

  17. X-ray beam finder

    DOE Patents [OSTI]

    Gilbert, H.W.

    1983-06-16T23:59:59.000Z

    An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

  18. Scattering apodizer for laser beams

    DOE Patents [OSTI]

    Summers, M.A.; Hagen, W.F.; Boyd, R.D.

    1984-01-01T23:59:59.000Z

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  19. Scattering apodizer for laser beams

    DOE Patents [OSTI]

    Summers, Mark A. (Livermore, CA); Hagen, Wilhelm F. (Livermore, CA); Boyd, Robert D. (Livermore, CA)

    1985-01-01T23:59:59.000Z

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  20. Generation of low-divergence laser beams

    DOE Patents [OSTI]

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1993-01-01T23:59:59.000Z

    Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source.

  1. Generation of low-divergence laser beams

    DOE Patents [OSTI]

    Kronberg, J.W.

    1993-09-14T23:59:59.000Z

    Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source. 11 figures.

  2. Particle beam injector system and method

    DOE Patents [OSTI]

    Guethlein, Gary

    2013-06-18T23:59:59.000Z

    Methods and devices enable coupling of a charged particle beam to a radio frequency quadrupole accelerator. Coupling of the charged particle beam is accomplished, at least in-part, by relying on of sensitivity of the input phase space acceptance of the radio frequency quadrupole to the angle of the input charged particle beam. A first electric field across a beam deflector deflects the particle beam at an angle that is beyond the acceptance angle of the radio frequency quadrupole. By momentarily reversing or reducing the established electric field, a narrow portion of the charged particle beam is deflected at an angle within the acceptance angle of the radio frequency quadrupole. In another configuration, beam is directed at an angle within the acceptance angle of the radio frequency quadrupole by the first electric field and is deflected beyond the acceptance angle of the radio frequency quadrupole due to the second electric field.

  3. Integral window/photon beam position monitor and beam flux detectors for x-ray beams

    DOE Patents [OSTI]

    Shu, Deming (Darien, IL); Kuzay, Tuncer M. (Naperville, IL)

    1995-01-01T23:59:59.000Z

    A monitor/detector assembly in a synchrotron for either monitoring the position of a photon beam or detecting beam flux may additionally function as a vacuum barrier between the front end and downstream segment of the beamline in the synchrotron. A base flange of the monitor/detector assembly is formed of oxygen free copper with a central opening covered by a window foil that is fused thereon. The window foil is made of man-made materials, such as chemical vapor deposition diamond or cubic boron nitrate and in certain configurations includes a central opening through which the beams are transmitted. Sensors of low atomic number materials, such as aluminum or beryllium, are laid on the window foil. The configuration of the sensors on the window foil may be varied depending on the function to be performed. A contact plate of insulating material, such as aluminum oxide, is secured to the base flange and is thereby clamped against the sensor on the window foil. The sensor is coupled to external electronic signal processing devices via a gold or silver lead printed onto the contact plate and a copper post screw or alternatively via a copper screw and a copper spring that can be inserted through the contact plate and coupled to the sensors. In an alternate embodiment of the monitor/detector assembly, the sensors are sandwiched between the window foil of chemical vapor deposition diamond or cubic boron nitrate and a front foil made of similar material.

  4. Improvements on the accuracy of beam bugs

    SciTech Connect (OSTI)

    Chen, Y.J.; Fessenden, T.

    1998-08-17T23:59:59.000Z

    At LLNL resistive wall monitors are used to measure the current and position used on ETA-II show a droop in signal due to a fast redistribution time constant of the signals. This paper presents the analysis and experimental test of the beam bugs used for beam current and position measurements in and after the fast kicker. It concludes with an outline of present and future changes that can be made to improve the accuracy of these beam bugs. of intense electron beams in electron induction linacs and beam transport lines. These, known locally as ''beam bugs'', have been used throughout linear induction accelerators as essential diagnostics of beam current and location. Recently, the development of a fast beam kicker has required improvement in the accuracy of measuring the position of beams. By picking off signals at more than the usual four positions around the monitor, beam position measurement error can be greatly reduced. A second significant source of error is the mechanical variation of the resistor around the bug.

  5. Analytical calculation of the smear for long-range beam-beam interactions

    E-Print Network [OSTI]

    Kaltchev, D I

    2010-01-01T23:59:59.000Z

    The Lie-algebraic method is used to develop generalized Courant-Snyder invariant in the presence of an arbitrary number of beam-beam collisions, head-on or long-range, in a storage ring collider. The invariant is obtained by concatenating nonlinear beam-beam maps in the horizontal plane and to first order in the beam-beam parameter. Tracking evidence is presented to illustrate that with LHC parameters the invariant is indeed preserved and can be used to predict the smear of horizontal emittance observed in tracking simulations. We discuss the limits of applicability of this model for realistic LHC collision schemes.

  6. Synchrotron radiation damping, intrabeam scattering and beam-beam simulations for HE-LHC

    SciTech Connect (OSTI)

    Valishev, A.; /Fermilab

    2011-03-01T23:59:59.000Z

    The proposed High-Energy LHC project presents an unusual combination of strong synchrotron radiation damping and intrabeam scattering, which is not seen in present-day hadron colliders. The subject of investigation reported in this paper was the simulation of beam-beam effect for the HE-LHC parameters. Parameters of SR and IBS are calculated, and the luminosity evolution is simulated in the absence of beam-beam interaction. Then, a weak-strong numerical simulation is used to predict the effect of beam-beam interaction on particle losses and emittance evolution.

  7. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-12-03T23:59:59.000Z

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  8. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-06-25T23:59:59.000Z

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  9. Protective laser beam viewing device

    DOE Patents [OSTI]

    Neil, George R.; Jordan, Kevin Carl

    2012-12-18T23:59:59.000Z

    A protective laser beam viewing system or device including a camera selectively sensitive to laser light wavelengths and a viewing screen receiving images from the laser sensitive camera. According to a preferred embodiment of the invention, the camera is worn on the head of the user or incorporated into a goggle-type viewing display so that it is always aimed at the area of viewing interest to the user and the viewing screen is incorporated into a video display worn as goggles over the eyes of the user.

  10. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A. (Riverside, CA); Beloussov, Alexandre V. (Bernardino, CA); Bakir, Julide (Alta Loma, CA); Armon, Deganit (Redlands, CA); Olsen, Howard B. (Colton, CA); Salem, Dana (Riverside, CA)

    2008-07-08T23:59:59.000Z

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  11. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A. (Riverside, CA); Beloussov, Alexandre V. (San Bernardino, CA); Bakir, Julide (Alta Loma, CA); Armon, Deganit (Longmeadow, MA); Olsen, Howard B. (Irvine, CA); Salem, Dana (Riverside, CA)

    2010-09-21T23:59:59.000Z

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  12. Nuclear astrophysics and electron beams

    SciTech Connect (OSTI)

    Schwenk, A. [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2013-11-07T23:59:59.000Z

    Electron beams provide important probes and constraints for nuclear astrophysics. This is especially exciting at energies within the regime of chiral effective field theory (EFT), which provides a systematic expansion for nuclear forces and electroweak operators based on quantum chromodynamics. This talk discusses some recent highlights and future directions based on chiral EFT, including nuclear structure and reactions for astrophysics, the neutron skin and constraints for the properties of neutron-rich matter in neutron stars and core-collapse supernovae, and the dark matter response of nuclei.

  13. SPEAR3 Beam Line Availability

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection245C Unlimited ReleaseWelcome ton n u a l r e p o rMarch 21,SPEAR3Beam

  14. Radiation beam calorimetric power measurement system

    DOE Patents [OSTI]

    Baker, John (Livermore, CA); Collins, Leland F. (Pleasanton, CA); Kuklo, Thomas C. (Ripon, CA); Micali, James V. (Dublin, CA)

    1992-01-01T23:59:59.000Z

    A radiation beam calorimetric power measurement system for measuring the average power of a beam such as a laser beam, including a calorimeter configured to operate over a wide range of coolant flow rates and being cooled by continuously flowing coolant for absorbing light from a laser beam to convert the laser beam energy into heat. The system further includes a flow meter for measuring the coolant flow in the calorimeter and a pair of thermistors for measuring the temperature difference between the coolant inputs and outputs to the calorimeter. The system also includes a microprocessor for processing the measured coolant flow rate and the measured temperature difference to determine the average power of the laser beam.

  15. Focused electron and ion beam systems

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Reijonen, Jani; Persaud, Arun; Ji, Qing; Jiang, Ximan

    2004-07-27T23:59:59.000Z

    An electron beam system is based on a plasma generator in a plasma ion source with an accelerator column. The electrons are extracted from a plasma cathode in a plasma ion source, e.g. a multicusp plasma ion source. The beam can be scanned in both the x and y directions, and the system can be operated with multiple beamlets. A compact focused ion or electron beam system has a plasma ion source and an all-electrostatic beam acceleration and focusing column. The ion source is a small chamber with the plasma produced by radio-frequency (RF) induction discharge. The RF antenna is wound outside the chamber and connected to an RF supply. Ions or electrons can be extracted from the source. A multi-beam system has several sources of different species and an electron beam source.

  16. Virtual mask digital electron beam lithography

    DOE Patents [OSTI]

    Baylor, Larry R. (Farragut, TN); Thomas, Clarence E. (Knoxville, TN); Voelkl, Edgar (Oak Ridge, TN); Moore, James A. (Powell, TN); Simpson, Michael L. (Knoxville, TN); Paulus, Michael J. (Knoxville, TN)

    1999-01-01T23:59:59.000Z

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made.

  17. Rippled beam free electron laser amplifier

    DOE Patents [OSTI]

    Carlsten, Bruce E. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

  18. Interfacial Properties of Electron Beam Cured Composites

    SciTech Connect (OSTI)

    Eberle, C.C.

    1999-12-30T23:59:59.000Z

    The objectives of the CRADA are to: Confirm that fiber-resin adhesion is responsible for the observed poor shear properties; Determine the mechanism(s) responsible for poor adhesion between carbon fibers and epoxy resins after e-beam curing; Develop and evaluate resin systems and fiber treatments to improve the properties of e-beam cured, carbon-fiber-reinforced composites; and Develop refined methods for processing e-beam cured, carbon-fiber-reinforced composites.

  19. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Livermore, CA)

    1993-01-01T23:59:59.000Z

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  20. Beam Characterization at the Neutron Radiography Facility

    SciTech Connect (OSTI)

    Sarah Morgan; Jeffrey King

    2013-01-01T23:59:59.000Z

    The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

  1. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, L.A.; Dane, C.B.

    1993-08-24T23:59:59.000Z

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  2. Effect of Diffusion on Bunched Beam Echo

    SciTech Connect (OSTI)

    Stupakov, G.V.; Chao, A.W.; /SLAC

    2011-09-01T23:59:59.000Z

    When a beam receives a dipole kick, its centroid signal decoheres due to the betatron tune spread in the beam. Long after the signal has decohered, however, a followup quadrupole kick to the beam brings a pronounced echo back to the centroid signal. This echo effect has been analyzed for the case of a bunched beam in Ref. [1]. In this work, the perturbation calculation of Ref. [1] is extended to include a diffusion in betatron amplitude. The effect of diffusion on the magnitude of the echo is then parameterized and studied.

  3. Focused ion beam source method and apparatus

    DOE Patents [OSTI]

    Pellin, Michael J. (Naperville, IL); Lykke, Keith R. (Gaithersburg, MD); Lill, Thorsten B. (Sunnyvale, CA)

    2000-01-01T23:59:59.000Z

    A focused ion beam having a cross section of submicron diameter, a high ion current, and a narrow energy range is generated from a target comprised of particle source material by laser ablation. The method involves directing a laser beam having a cross section of critical diameter onto the target, producing a cloud of laser ablated particles having unique characteristics, and extracting and focusing a charged particle beam from the laser ablated cloud. The method is especially suited for producing focused ion beams for semiconductor device analysis and modification.

  4. Improvement of Ion-Beam Energy Resolution in a Solenoid-based Radioactive Nuclear Beam Facility

    E-Print Network [OSTI]

    Becchetti, Fred

    Improvement of Ion-Beam Energy Resolution in a Solenoid-based Radioactive Nuclear Beam Facility of Philosophy (Nuclear Engineering and Radiological Sciences) in The University of Michigan 2010 Doctoral

  5. The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

    SciTech Connect (OSTI)

    Ma, Y., E-mail: yjma@ciae.ac.cn; Cui, B.; Ma, R.; Tang, B.; Chen, L.; Huang, Q.; Jiang, W. [China Institute of Atomic Energy, Beijing 102413 (China)] [China Institute of Atomic Energy, Beijing 102413 (China)

    2014-02-15T23:59:59.000Z

    The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org , p. 267]. For low intensity ion beam [30–300 keV/1 pA–10 ?A], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 ?A], the beam profile scanner will be installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.

  6. Method and apparatus for laser-controlled proton beam radiology

    DOE Patents [OSTI]

    Johnstone, Carol J. (Warrenville, IL)

    1998-01-01T23:59:59.000Z

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H.sup.- beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H.sup.- beam and laser beam to produce a neutral beam therefrom within a subsection of the H.sup.- beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H.sup.- beam in order to form the neutral beam in subsections of the H.sup.- beam. As the scanning laser moves across the H.sup.- beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser.

  7. Method and apparatus for laser-controlled proton beam radiology

    DOE Patents [OSTI]

    Johnstone, C.J.

    1998-06-02T23:59:59.000Z

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H{sup {minus}} beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H{sup {minus}} beam and laser beam to produce a neutral beam therefrom within a subsection of the H{sup {minus}} beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H{sup {minus}} beam in order to form the neutral beam in subsections of the H{sup {minus}} beam. As the scanning laser moves across the H{sup {minus}} beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser. 9 figs.

  8. Studies on beam propagation pertaining to beamed microwave power transmission and open resonator quasi-optics

    E-Print Network [OSTI]

    McCleary, James Carlton

    1991-01-01T23:59:59.000Z

    on the space shuttle. A near-field program is used to compare the collection efficiencies obtainable with a parabolic dish and a resonant Gaussian beam antenna. The second application of the computer programs is the analysis of a reference system for beaming... characteristics of the maximum tapers in Table 4. . 81 45 Collection efficiency characteristics of the high efficiency tapers. 84 46 Proposed shuttle beamed power demonstration using an 8 ft. parabolic dish as the transmitter antenna. 89 47 Gaussian beam...

  9. Lattice design for head-on beam-beam compensation at RHIC

    SciTech Connect (OSTI)

    Montag, C.

    2011-03-28T23:59:59.000Z

    Electron lenses for head-on beam-beam compensation will be installed in IP 10 at RHIC. Compensation of the beam-beam effect experienced at IP 8 requires betatron phase advances of {Delta}{psi} = k {center_dot} {pi} between the proton-proton interaction point at IP 8, and the electron lens at IP 10. This paper describes the lattice solutions for both the BLUE and the YELLOW ring to achieve this goal.

  10. Cascaded injection resonator for coherent beam combining of laser arrays

    DOE Patents [OSTI]

    Kireev, Vassili [Sunnyvale, CA; Liu, Yun; Protopopescu, Vladimir [Knoxville, TN; Braiman, Yehuda [Oak Ridge, TN

    2008-10-21T23:59:59.000Z

    The invention provides a cascaded injection resonator for coherent beam combining of laser arrays. The resonator comprises a plurality of laser emitters arranged along at least one plane and a beam sampler for reflecting at least a portion of each laser beam that impinges on the beam sampler, the portion of each laser beam from one of the laser emitters being reflected back to another one of the laser emitters to cause a beam to be generated from the other one of the laser emitters to the beam reflector. The beam sampler also transmits a portion of each laser beam to produce a laser output beam such that a plurality of laser output beams of the same frequency are produced. An injection laser beam is directed to a first laser emitter to begin a process of generating and reflecting a laser beam from one laser emitter to another laser emitter in the plurality. A method of practicing the invention is also disclosed.

  11. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOE Patents [OSTI]

    Karl, Jr., Robert R. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  12. Polarization of fast particle beams by collisional pumping

    DOE Patents [OSTI]

    Stearns, J. Warren (Castro Valley, CA); Kaplan, Selig N. (El Cerrito, CA); Pyle, Robert V. (Berkeley, CA); Anderson, L. Wilmer (Madison, WI); Ruby, Lawrence (Berkeley, CA); Schlachter, Alfred S. (Oakland, CA)

    1988-01-01T23:59:59.000Z

    Method and apparatus for highly polarizing a fast beam of particles by collisional pumping, including generating a fast beam of particles, and also generating a thick electron-spin-polarized medium positioned as a target for the beam. The target is made sufficiently thick to allow the beam to interact with the medium to produce collisional pumping whereby the beam becomes highly polarized.

  13. LCDETxxxxxxx Improved TESLA Optics and Beam Induced

    E-Print Network [OSTI]

    LC­DET­xxxx­xxx Improved TESLA Optics and Beam Induced Backgrounds Update Karsten BË?uÃ?er, DESY and Olivier Napoly, CEA/Saclay LCWS 2002, Jeju, Korea Abstract A new tesla optics with l*=5m is under development. An update is given on the simulation of the beam induced backgrounds in the TESLA detector. 1

  14. Fast Beam-Based BPM Calibration

    SciTech Connect (OSTI)

    Bertsche, K.; Loos, H.; Nuhn, H.-D.; Peters, F.; /SLAC

    2012-10-15T23:59:59.000Z

    The Alignment Diagnostic System (ADS) of the LCLS undulator system indicates that the 33 undulator quadrupoles have extremely high position stability over many weeks. However, beam trajectory straightness and lasing efficiency degrade more quickly than this. A lengthy Beam Based Alignment (BBA) procedure must be executed every two to four weeks to re-optimize the X-ray beam parameters. The undulator system includes RF cavity Beam Position Monitors (RFBPMs), several of which are utilized by an automatic feedback system to align the incoming electron-beam trajectory to the undulator axis. The beam trajectory straightness degradation has been traced to electronic drifts of the gain and offset of the BPMs used in the beam feedback system. To quickly recover the trajectory straightness, we have developed a fast beam-based procedure to recalibrate the BPMs. This procedure takes advantage of the high-precision monitoring capability of the ADS, which allows highly repeatable positioning of undulator quadrupoles. This report describes the ADS, the position stability of the LCLS undulator quadrupoles, and some results of the new recovery procedure.

  15. High-energy electron beam technology

    SciTech Connect (OSTI)

    Danko, J.C.; Lundin, C.D. (Univ. of Tennessee, Knoxville, TN (United States)); Nolting, E.E. (Naval Surface Warfare Center, White Oak, MD (United States))

    1994-09-01T23:59:59.000Z

    A high-energy electron beam (HEEB) technology was developed under the US Department of Defense (DOD) charged-particle-beam (CPB) directed-energy program. The program's objective was advanced military weapon systems. For the past two decades, charged-particle-beam research focused on producing intense beams and the vehicles to deliver large amounts of electrical energy. The charged-particle beams of interest for weapon systems had particle energies up to 100 MeV, beam currents of tens of kiloamperes, and propagation distances in excess of 100 m. However, such high energy levels are not required for industrial uses of the technology. It is anticipated that these less-aggressive beams will provide an electrical heat source suitable for a variety of materials processing applications, including surface treatment, joining, shock hardening, phase-transformation hardening, peening, shock-wave compaction, and melting. Much more R and D is needed to transfer to industry the high-energy electron beam technology developed in the CPB program. For example, its power as a materials processing tool must be convincingly demonstrated. Also required are compact, reliable accelerators that are relatively simple to use and reasonably priced.

  16. Polymer surface treatment with particle beams

    DOE Patents [OSTI]

    Stinnett, R.W.; VanDevender, J.P.

    1999-05-04T23:59:59.000Z

    A polymer surface and near surface treatment process produced by irradiation with high energy particle beams is disclosed. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications. 16 figs.

  17. Emittance growth from electron beam modulation

    SciTech Connect (OSTI)

    Blaskiewicz, M.

    2009-12-01T23:59:59.000Z

    In linac ring colliders like MeRHIC and eRHIC a modulation of the electron bunch can lead to a modulation of the beam beam tune shift and steering errors. These modulations can lead to emittance growth. This note presents simple formulas to estimate these effects which generalize some previous results.

  18. Policy Issues for Retail Beamed Power Transmission

    E-Print Network [OSTI]

    solar electric power using retail delivery of beamed power. Recent advances in power beaming have made to enable widespread adoption of this clean and sustainable contribution to meeting energy needs. It is seen to micro-renewable energy resource exploitation since wired power transmission is only cost effective over

  19. Stability design of long precast concrete beams

    E-Print Network [OSTI]

    Burgoyne, Chris

    lateral de¯ection measured in the minor- axis direction (which rotates with y) v0 initial lateral imperfection w self-weight of beam per unit length wcr critical self-weight of beam to cause buckling, per unit length y lateral de¯ection measured along a ®xed axis y0 initial lateral imperfection yb distance

  20. GPU-optimized Code for Long-term Simulations of Beam-beam Effects in Colliders

    SciTech Connect (OSTI)

    Roblin, Yves [JLAB; Morozov, Vasiliy [JLAB; Terzic, Balsa [JLAB; Aturban, Mohamed A. [Old Dominion University; Ranjan, D. [Old Dominion University; Zubair, Mohammed [Old Dominion University

    2013-06-01T23:59:59.000Z

    We report on the development of the new code for long-term simulation of beam-beam effects in particle colliders. The underlying physical model relies on a matrix-based arbitrary-order symplectic particle tracking for beam transport and the Bassetti-Erskine approximation for beam-beam interaction. The computations are accelerated through a parallel implementation on a hybrid GPU/CPU platform. With the new code, a previously computationally prohibitive long-term simulations become tractable. We use the new code to model the proposed medium-energy electron-ion collider (MEIC) at Jefferson Lab.

  1. SPALLATION NEUTRON SOURCE BEAM CURRENT MONITOR ELECTRONICS.

    SciTech Connect (OSTI)

    KESSELMAN, M.

    2001-06-18T23:59:59.000Z

    The Spallation Neutron Source (SNS) to be constructed at ORNL is a collaboration of six laboratories. Beam current monitors for SNS will be used to monitor H-minus and H-plus beams ranging from the 15 mA (tune-up in the Front End and Linac) to over 60 A fully accumulated in the Ring. The time structure of the beams to be measured range from 645 nsec ''mini'' bunches, at the 1.05 MHz ring revolution rate, to an overall 1 mS long macro pulse. Beam current monitors (BCMs) for SNS have requirements depending upon their location within the system. The development of a general approach to satisfy requirements of various locations with common components is a major design objective. This paper will describe the development of the beam current monitors and electronics.

  2. Carbon Fiber Damage in Particle Beam

    E-Print Network [OSTI]

    Dehning, B; Kroyer, T; Meyer, M; Sapinski, M

    2011-01-01T23:59:59.000Z

    Carbon fibers are commonly used as moving targets in beam wire scanners. The heating of the fiber due to energy loss of the particles travelling through is simulated with Geant4. The heating induced by the beam electromagnetic field is estimated with ANSYS. The heat transfer and sublimation processes are modelled. Due to the model nonlinearity, a numerical approach based on discretization of the wire movement is used to solve it for particular beams. Radiation damage to the fiber is estimated with SRIM. The model is tested with available SPS and LEP data and a dedicated damage test on the SPS beam is performed followed by a post-mortem analysis of the wire remnants. Predictions for the LHC beams are made.

  3. Beam Loss Studies for the 2-MW LBNE Proton Beam Line

    SciTech Connect (OSTI)

    Drozhdin, A.I.; Childress, S.R.; Mokhov, N.V.; Tropin, I.S.; Zwaska, R.; /Fermilab

    2012-05-01T23:59:59.000Z

    Severe limits are put on allowable beam loss during extraction and transport of a 2.3 MW primary proton beam for the Long Baseline Neutrino Experiment (LBNE) at Fermilab. Detailed simulations with the STRUCT and MARS codes have evaluated the impact of beam loss of 1.6 x 10{sup 14} protons per pulse at 120 GeV, ranging from a single pulse full loss to sustained small fractional loss. It is shown that loss of a single beam pulse at 2.3 MW will result in a catastrophic event: beam pipe destruction, damaged magnets and very high levels of residual radiation inside and outside the tunnel. Acceptable beam loss limits have been determined and robust solutions developed to enable efficient proton beam operation under these constraints.

  4. A non-invasive beam profile monitor for charged particle beams

    SciTech Connect (OSTI)

    Tzoganis, Vasilis, E-mail: vasileios.tzoganis@cockcroft.ac.uk [Cockcroft Institute, Daresbury Sci-Tech, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); RIKEN Nishina Centre, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Welsch, Carsten P. [Cockcroft Institute, Daresbury Sci-Tech, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

    2014-05-19T23:59:59.000Z

    Non-interceptive beam profile monitors are highly desirable in almost all particle accelerators. Such techniques are especially valuable in applications where real time monitoring of the beam properties is required while beam preservation and minimal influence on the vacuum are of the greatest importance. This applies to many kinds of accelerators such as high energy machines where the normal diagnostics cannot withstand the beam's power, medical machines where treatment time is valuable and cannot be allocated to diagnostics and also low energy, low intensity accelerators where the beam's properties are difficult to measure. This paper presents the design of a gas-jet based beam profile monitor which was developed and commissioned at the Cockcroft Institute and can operate in a very large background pressure range from 10{sup ?7} down to below 10{sup ?11} millibars. The functioning principle of the monitor is described and the first experimental results obtained using a 5?keV electron beam are discussed.

  5. Laser Beam Profile Influence on LIBS Analytical Capabilities: Single vs. Multimode Beam

    E-Print Network [OSTI]

    Lednev, Vasily N; Bunkin, Alexey F

    2013-01-01T23:59:59.000Z

    Single vs. multimode laser beams have been compared for laser ablation on steel samples. Laser plasma properties and analytical capabilities (precision, limit of detection) were used as key parameters for comparison. Peak fluence at focal spot has been observed to be higher for Gaussian beam despite ~14-fold lower pulse energy. A comparison of Gaussian and multimode beams with equal energy was carried out in order to estimate influence of beam profile only. Single mode lasing (Gaussian beam) results in better reproducibility of analytical signals compared to multimode lasing while laser energy reproducibility was the same for both cases. Precision improvements were attributed to more stable laser ablation due to better reproducibility of beam profile fluence at laser spot. Plasma temperature and electron density were higher for Gaussian laser beam. Calibration curves were obtained for four elements under study (Cr, Mn, Si, Cu). Two sampling (drilling and scanning procedures) and two optical detection schemes ...

  6. World record neutron beam at Los Alamos National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    World record neutron beam at LANL World record neutron beam at Los Alamos National Laboratory Scientists have created the largest neutron beam ever made by a short-pulse laser,...

  7. Horizontal Beam Tubes - HFIR Technical Parameters | ORNL Neutron...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Beam Tubes The reactor has four horizontal beam tubes that supply the neutrons to the neutron scattering instruments. Details for each beam tube and instrument can be found on...

  8. Intense ion beam propagation in a reactor sized chamber

    E-Print Network [OSTI]

    Vay, J.L.; Deutsch, C.

    2000-01-01T23:59:59.000Z

    beams in a heavy ion fusion reactor chamber filled with lowIon Fusion, Intense Ion Beams, Reaction Chamber. P.A.C.S.heavy ion beam propagation in the reaction chamber, Fus.

  9. michael smith ornlradioactive beams: equipment & techniques recoil separators

    E-Print Network [OSTI]

    michael smith ornlradioactive beams: equipment & techniques recoil separators approach! · directly Smith, Rolfs, Barnes NIMA306 (1991) 233 #12;michael smith ornlradioactive beams: equipment & techniques;michael smith ornlradioactive beams: equipment & techniques recoil separators proof of concept with 12C

  10. The CERN Beam Interlock System: Principle and Operational Experience

    E-Print Network [OSTI]

    Puccio, B; Kwiatkowski, M; Romera Ramirez, I; Todd, B

    2010-01-01T23:59:59.000Z

    A complex Machine Protection System has been designed to protect the LHC machine from an accidental release of the beam energy, with about 20 subsystems providing status information to the Beam Interlock System that is the backbone of machine protection. Only if the subsystems are in the correct state for beam operation, the Beam Interlock System receives a status flag and beam can be injected into LHC (Large Hadron Collider). The Beam Interlock System also relays commands from the connected subsystems in case of failure for triggering the LHC Beam Dumping System. To maintain the required level of safety of the Beam Interlock System, the performance of the key components is verified before every fill of the machine and validated after every emergency beam dump before beam operation is allowed to continue. This includes all critical paths, starting from the inputs from connected systems triggering a beam dump request, followed by the correct interruption and propagation sequence of the two redundant beam permi...

  11. Vibration suppression, stabilization, motion planning and tracking for flexible beams

    E-Print Network [OSTI]

    Siranosian, Antranik Antonio

    2009-01-01T23:59:59.000Z

    Target System . . . . 3.2.3 Flexible Beams . . . 3.3 MotionPlanning and Tracking for Flexible Beams A Dissertationand De?ection Angle for Flexible Beams,” ASME Journal of

  12. Electrostatic wire for stabilizing a charged particle beam

    DOE Patents [OSTI]

    Prono, Daniel S. (Livermore, CA); Caporaso, George J. (Livermore, CA); Briggs, Richard J. (Livermore, CA)

    1985-01-01T23:59:59.000Z

    In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

  13. ar ion beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the ion optical code IBSimu. The simulations predict self-consistently the triangular and hollow beam structures which are often observed experimentally with ECRIS ion beams. The...

  14. argon ion beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the ion optical code IBSimu. The simulations predict self-consistently the triangular and hollow beam structures which are often observed experimentally with ECRIS ion beams. The...

  15. Long Plasma Source for Heavy Ion Beam Charge Neutralization

    E-Print Network [OSTI]

    Efthimion, P.C.

    2009-01-01T23:59:59.000Z

    neutralizing plasma column the heavy ion beam can focus to aPlasmas are a source of unbound electrons for charge neutralizing intense heavy ion beams to focus

  16. Beam manipulation by self-wakefield at ATF

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Committee and the ATF Users' Meetings, April 26 - 27, 2012 Outline 1. Enhanced Transformer Ratio demonstration (wakefield mapping with the shaped beam) 2. Tunable beam energy...

  17. Fuel Target Implosion in Ion beam Inertial Confinement Fusion

    E-Print Network [OSTI]

    Kawata, Shigeo

    2015-01-01T23:59:59.000Z

    The numerical results for the fuel target implosion are presented in order to clarify the target physics in ion beam inertial fusion. The numerical analyses are performed for a direct-driven ion beam target. In the paper the following issues are studied: the beam obliquely incidence on the target surface, the plasma effect on the beam-stopping power, the beam particle energy, the beam time duration, the target radius, the beam input energy and the non-uniformity effect on the fuel target performance. In this paper the beam ions are protons.

  18. Ion beam assisted deposition of thermal barrier coatings

    DOE Patents [OSTI]

    Youchison, Dennis L. (Albuquerque, NM); McDonald, Jimmie M. (Albuquerque, NM); Lutz, Thomas J. (Albuquerque, NM); Gallis, Michail A. (Albuquerque, NM)

    2010-11-23T23:59:59.000Z

    Methods and apparatus for depositing thermal barrier coatings on gas turbine blades and vanes using Electron Beam Physical Vapor Deposition (EBPVD) combined with Ion Beam Assisted Deposition (IBAD).

  19. Physics with Rare Isotope Beams

    SciTech Connect (OSTI)

    Segel, Ralph E. [Northwestern University] [Northwestern University

    2013-11-08T23:59:59.000Z

    Using stable and radioactive beams provided by ATLAS nuclear reactions of special interest in astrophysics have been studied with emphasis on breakout from the hot CNO cycle to the rp-process. The masses of nuclear fragments provided by a strong fission source have been measured in order to help trace the path of the r process. 8Li ions produced by the d(7Li,8Li)n reaction have been trapped and the electrons and alphas emitted in the ensuing beta-decay measured. The neutrino directions were therefore determined, which leads to a measurement of the electron-neutrino correlation. The energies and kinematics are such that a sensitive search for any tensor admixture could be performed and an upper limit of 0.6% was placed on any such admixture. Earlier work on the electromagnetic form factors of the proton was extended. Graduate students were active participants in all of these eperiments, which formed the basis for six PhD theses.

  20. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, Craig L. (Albuquerque, NM)

    1987-01-01T23:59:59.000Z

    A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  1. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, C.L.

    1984-03-16T23:59:59.000Z

    A generator for producing an intense relativisitc electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  2. Injected Beam Dynamics in SPEAR3

    SciTech Connect (OSTI)

    Corbett, Jeff; /SLAC; Fisher, Alan; /SLAC; Huang, Xiaobiao; /SLAC; Safranek, James; /SLAC; Westerman, Stuart; /SLAC; Cheng, Weixing; /Brookhaven; Mok, Walter; /Unlisted

    2012-06-21T23:59:59.000Z

    For the top-off operation it is important to understand the time evolution of charge injected into the storage ring. The large-amplitude horizontal oscillation quickly filaments and decoheres, and in some cases exhibits non-linear x-y coupling before damping to the stored orbit. Similarly, in the longitudinal dimension, any mismatch in beam arrival time, beam energy or phase-space results in damped, non-linear synchrotron oscillations. In this paper we report on measurements of injection beam dynamics in the transverse and longitudinal planes using turn-by-turn BPMs, a fast-gated, image-intensified CCD camera and a Hamamatsu C5680 streak camera.

  3. Intense steady state electron beam generator

    DOE Patents [OSTI]

    Hershcovitch, A.; Kovarik, V.J.; Prelec, K.

    1990-07-17T23:59:59.000Z

    An intense, steady state, low emittance electron beam generator is formed by operating a hollow cathode discharge plasma source at critical levels in combination with an extraction electrode and a target electrode that are operable to extract a beam of fast primary electrons from the plasma source through a negatively biased grid that is critically operated to repel bulk electrons toward the plasma source while allowing the fast primary electrons to move toward the target in the desired beam that can be successfully transported for relatively large distances, such as one or more meters away from the plasma source. 2 figs.

  4. Energy-beam-driven rapid fabrication system

    DOE Patents [OSTI]

    Keicher, David M. (Albuquerque, NM); Atwood, Clinton L. (Albuquerque, NM); Greene, Donald L. (Corrales, NM); Griffith, Michelle L. (Albuquerque, NM); Harwell, Lane D. (Albuquerque, NM); Jeantette, Francisco P. (Albuquerque, NM); Romero, Joseph A. (Albuquerque, NM); Schanwald, Lee P. (Albuquerque, NM); Schmale, David T. (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    An energy beam driven rapid fabrication system, in which an energy beam strikes a growth surface to form a molten puddle thereon. Feed powder is then injected into the molten puddle from a converging flow of feed powder. A portion of the feed powder becomes incorporated into the molten puddle, forcing some of the puddle contents to freeze on the growth surface, thereby adding an additional layer of material. By scanning the energy beam and the converging flow of feed powder across the growth surface, complex three-dimensional shapes can be formed, ready or nearly ready for use. Nearly any class of material can be fabricated using this system.

  5. Automated beam steering using optimal control

    SciTech Connect (OSTI)

    Allen, C. K. (Christopher K.)

    2004-01-01T23:59:59.000Z

    We present a steering algorithm which, with the aid of a model, allows the user to specify beam behavior throughout a beamline, rather than just at specified beam position monitor (BPM) locations. The model is used primarily to compute the values of the beam phase vectors from BPM measurements, and to define cost functions that describe the steering objectives. The steering problem is formulated as constrained optimization problem; however, by applying optimal control theory we can reduce it to an unconstrained optimization whose dimension is the number of control signals.

  6. Real Beamline Optics from a Synthetic Beam

    SciTech Connect (OSTI)

    Ryan Bodenstein,Michael Tiefenback,Yves Roblin

    2010-05-01T23:59:59.000Z

    The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab can be described as a series of concatenated beamlines. Methods used to measure the Twiss parameters in closed orbit machines are not applicable in such open ended systems. We are using properly selected sets of real orbits in the accelerator, as one would for numerical analysis. The evolution of these trajectories along the beamline models the behavior of a synthetic beam which deterministically supplements beam profile-based Twiss parameter measurements and optimizes the efficiency of beamline tuning. Examples will be presented alongside a description of the process.

  7. Acoustics of finite-aperture vortex beams

    E-Print Network [OSTI]

    Mitri, F G

    2014-01-01T23:59:59.000Z

    A method based on the Rayleigh-Sommerfeld surface integral is provided, which makes it feasible to rigorously model, evaluate and compute the acoustic scattering and other mechanical effects of finite-aperture vortex beams such as the acoustic radiation force and torque on a viscoelastic sphere in various applications in acoustic tweezers and microfluidics, particle entrapment, manipulation and rotation. Partial-wave series expansions are derived for the incident field of acoustic spiraling (vortex) beams, comprising high-order Bessel and Bessel-Gauss beams.

  8. Non-Vacuum Electron Beam Welding

    SciTech Connect (OSTI)

    Hershcovitch, Ady

    2007-01-31T23:59:59.000Z

    Original objectives of CRADA number BNL-01-03 between BNL and Acceleron, Inc., were to further develop the Plasma Window concept (a BNL invention covered by US Patent number 5,578,831), mate the Plasma Window to an existing electron beam welder to perform in-air electron beam welding, and mount the novel nonvacuum electron beam welder on a robot arm. Except for the last objective, all other goals were met or exceeded. Plasma Window design and operation was enhanced during the project, and it was successfully mated to a conventional4 kW electron beam welder. Unprecedented high quality non-vacuum electron beam . welding was demonstrated. Additionally, a new invention the Plasma Shield (US Patent number 7,075,030) that chemically and thermally shields a target object was set forth. Great interest in the new technology was shown by a number of industries and three arcs were sold for experimental use. However, the welding industry requested demonstration of high speed welding, which requires 100 kW electron beam welders. The cost of such a welder involved the need for additional funding. Therefore, some of the effort was directed towards Plasma Shield development. Although relatively a small portion of the R&D effort was spent on the Plasma Shield, some very encouraging results were obtained. Inair Plasma Shield was demonstrated. With only a partial shield, enhanced vacuum separation and cleaner welds were realized. And, electron beam propagation in atmosphere improved by a factor of about 3. Benefits to industry are the introduction of two new technologies. BNL benefited from licensing fee cash, from partial payment for employee salary, and from a new patent In addition to financial benefits, a new technology for physics studies was developed. Recommendations for future work are to develop an under-water plasma shield, perform welding with high-power electron beam:s, carry out other plasma shielded electron beam and laser processes. Potential benefits from further R&D are that various processes involving electron ion and laser beams that have now restrictions can, with the Plasma Shield be performed in practically any environment. For example, electron beam and laser welding can be performed under water, as well as, in situ repair of ship and nuclear reactor components. The plasma shield results in both thermal (since the plasma is hotter than the environment) and chemical shielding. The latter feature brings about in-vacuum process purity out of vacuum, and the thermal shielding aspect results in higher production rates.

  9. Neutron measurements from beam-target reactions at the ELISE neutral beam test facility

    SciTech Connect (OSTI)

    Xufei, X., E-mail: xiexufei@pku.edu.cn; Fan, T. [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Nocente, M.; Gorini, G. [Dipartimento di Fisica “G. Occhialini”, Università di Milano-Bicocca, Milano 20216 (Italy); Istituto di Fisica del Plasma “P. Caldirola”, Milano 20216 (Italy); Bonomo, F. [Consorzio RFX, Padova 35100 (Italy); Istituto Gas Ionizzati, CNR, Padova 35100 (Italy); Franzen, P.; Fröschle, M. [Max-Planck-Institut für Plasmaphysik, Garching 84518 (Germany); Grosso, G.; Tardocchi, M. [Istituto di Fisica del Plasma “P. Caldirola”, Milano 20216 (Italy); Grünauer, F. [Physics Consulting, Zorneding 85604 (Germany); Pasqualotto, R. [Consorzio RFX, Padova 35100 (Italy)

    2014-11-15T23:59:59.000Z

    Measurements of 2.5 MeV neutron emission from beam-target reactions performed at the ELISE neutral beam test facility are presented in this paper. The measurements are used to study the penetration of a deuterium beam in a copper dump, based on the observation of the time evolution of the neutron counting rate from beam-target reactions with a liquid scintillation detector. A calculation based on a local mixing model of deuterium deposition in the target up to a concentration of 20% at saturation is used to evaluate the expected neutron yield for comparison with data. The results are of relevance to understand neutron emission associated to beam penetration in a solid target, with applications to diagnostic systems for the SPIDER and MITICA Neutral Beam Injection prototypes.

  10. ICFA Mini-Workshop on Beam-Beam Effects in Hadron Colliders

    E-Print Network [OSTI]

    Papotti, G; BB2013; BB 2013

    2014-01-01T23:59:59.000Z

    This report contains the Proceedings of the ICFA Mini-Workshop on Beam-Beam Effects in Hadron Colliders held at CERN from 18 to 22 March 2013. It was the first of its kind after the successful start of LHC operation where a vast amount of beam-beam observations emerged. It brought together 58 international experts in the field and the purpose of this workshop was to review the present knowledge in the fields of beam-beam theory, simulations and observations. In the summary session the participants acknowledged the enormous progress made in recent years and the introduction of new concepts and tools. The workshop was concluded by a discussion on future research work with emphasis on the LHC operation and future circular colliders.

  11. Electron gun jitter effects on beam bunching

    SciTech Connect (OSTI)

    Liu, M. S. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan)

    2014-02-15T23:59:59.000Z

    For routine operation of Beijing Electron Positron Collider II (BEPCII) linac, many factors may affect the beam bunching process directly or indirectly. We present the measurements and analyses of the gun timing jitter, gun high voltage jitter, and beam energy at the exit of the standard acceleration section of the linac quantitatively. Almost 80 mV and more than 200 ps of gun high voltage and time jitters have ever been measured, respectively. It was analyzed that the gun timing jitter produced severe effects on beam energy than the gun high voltage jitter, if the timing jitter exceeded 100 ps which eventually deteriorates both the beam performance and the injection rate to the storage ring.

  12. Electron beam related advances at ATF

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to cavity loading. Compensation of the dispersion is needed at the level of a few mm. * Plasma Wakefield experiment needs extra small focus (10 micron) of the bunched beam...

  13. Synchronous Characterization of Semiconductor Microcavity Laser Beam

    E-Print Network [OSTI]

    Wang, Tao

    2015-01-01T23:59:59.000Z

    We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show that the laser frequency is an inhomogeneous distribution below threshold, but that it becomes homogeneous across the fundamental Gaussian mode above threshold. The beam's tails deviations from the Gaussian shape, however, are accompanied by sizeable fluctuations in the laser wavelength, possibly deriving from manufacturing details and from the influence of spontaneous emission in the very low intensity wings. In addition to the synchronous spatial characterization, a temporal analysis at any given point in the beam cross-section is carried out. Using this method, the beam homogeneity and spatial shape, energy density, energy center and the defects-related spectrum can also be extracted from these high-resolution pictures.

  14. Optical chirped beam amplification and propagation

    DOE Patents [OSTI]

    Barty, Christopher P.

    2004-10-12T23:59:59.000Z

    A short pulse laser system uses dispersive optics in a chirped-beam amplification architecture to produce high peak power pulses and high peak intensities without the potential for intensity dependent damage to downstream optical components after amplification.

  15. Scrap uranium recycling via electron beam melting

    SciTech Connect (OSTI)

    McKoon, R.

    1993-11-01T23:59:59.000Z

    A program is underway at the Lawrence Livermore National Laboratory (LLNL) to recycle scrap uranium metal. Currently, much of the material from forging and machining processes is considered radioactive waste and is disposed of by oxidation and encapsulation at significant cost. In the recycling process, uranium and uranium alloys in various forms will be processed by electron beam melting and continuously cast into ingots meeting applicable specifications for virgin material. Existing vacuum processing facilities at LLNL are in compliance with all current federal and state environmental, safety and health regulations for the electron beam melting and vaporization of uranium metal. One of these facilities has been retrofitted with an auxiliary electron beam gun system, water-cooled hearth, crucible and ingot puller to create an electron beam melt furnace. In this furnace, basic process R&D on uranium recycling will be performed with the goal of eventual transfer of this technology to a production facility.

  16. Shear Behaviour of Concrete Beams Reinforced with

    E-Print Network [OSTI]

    and Construction R&D Facility ofthe University ofManitoba to test a total ofnine beams reinforced with GFRP and encouragement went beyond the academic roles. Many special thanks are extended to Dr. Kenneth. R. Hughes. His

  17. Predicted Bremsstrahlung generation by energetic electron beams

    SciTech Connect (OSTI)

    Faehl, R.J.; Snell, C.M.; Keinigs, R.K.

    1991-01-01T23:59:59.000Z

    The CYLTRAN photon/electron Monte Carlo code has been employed to predict Bremsstrahlung generation by monoenergetic electron beams from 10 to 1000 MeV. The forward-directed Bremsstrahlung intensity is investigated as a function of beam energy converter thickness, and material. At high energies, the forward extraction efficiency is maximized by using converters that are about 0.1-electron ranges thick. The largest intensities are attained with low-Z converter materials such as beryllium. Because the Bremsstrahlung radiation is strongly forward-directed, low divergence of the incident electron beam is crucial. Under deal conditions, a 1000-MeV beam can produce intensities up to 10{sup 8} MeV per steradian, per incident electron. 9 refs., 32 figs., 12 tabs.

  18. High Brightness Beam Applications: Energy Recovered Linacs

    SciTech Connect (OSTI)

    Geoffrey A. Krafft

    2005-09-01T23:59:59.000Z

    In the first part of the paper some general statements are made regarding applications suitable for utilizing energy recovered linacs (ERLs) by contrasting their potential performance to that of single pass linacs and storage rings. As a result of their potential for extremely good beam quality in combination with high average beam current, ERLs have been used and considered as drivers of both free electron laser and partially coherent photon sources, from THz through X-rays; as a suitable technology for high energy electron cooling; and as a continuous or semi-continuous electron beam source for high energy colliders. At present, beam requirements tend to be highly matched to end use requirements. By reviewing some of the many examples which have either been reduced to practice, or are being explored presently, one can develop an appreciation for the wide range of parameters being considered in ERL applications.

  19. Pseudo ribbon metal ion beam source

    SciTech Connect (OSTI)

    Stepanov, Igor B., E-mail: stepanovib@tpu.ru; Ryabchikov, Alexander I.; Sivin, Denis O.; Verigin, Dan A. [Tomsk Polytechnic University, 30 Lenina Avenue, Tomsk 634050 (Russian Federation)] [Tomsk Polytechnic University, 30 Lenina Avenue, Tomsk 634050 (Russian Federation)

    2014-02-15T23:59:59.000Z

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface.

  20. The Radioactive Beam Program at Argonne

    E-Print Network [OSTI]

    B. B. Back

    2006-06-06T23:59:59.000Z

    In this talk I will present selected topics of the ongoing radioactive beam program at Argonne and discuss the capabilities of the CARIBU radioactive ion production facility as well as plans for construction of a novel superconducting solenoid spectrometer.

  1. Oblique reflections of internal gravity wave beams

    E-Print Network [OSTI]

    Karimi, Hussain H. (Hussain Habibullah)

    2012-01-01T23:59:59.000Z

    We study nonlinear effects in reflections of internal gravity wave beams in a continuously stratified liquid which are incident upon a uniform slope at an oblique angle. Wave motion in a stratified fluid medium is unique ...

  2. Solar Power Beaming: From Space to Earth

    SciTech Connect (OSTI)

    Rubenchik, A M; Parker, J M; Beach, R J; Yamamoto, R M

    2009-04-14T23:59:59.000Z

    Harvesting solar energy in space and power beaming the collected energy to a receiver station on Earth is a very attractive way to help solve mankind's current energy and environmental problems. However, the colossal and expensive 'first step' required in achieving this goal has to-date stifled its initiation. In this paper, we will demonstrate that recent advance advances in laser and optical technology now make it possible to deploy a space-based system capable of delivering 1 MW of energy to a terrestrial receiver station, via a single unmanned commercial launch into Low Earth Orbit (LEO). Figure 1 depicts the overall concept of our solar power beaming system, showing a large solar collector in space, beaming a coherent laser beam to a receiving station on Earth. We will describe all major subsystems and provide technical and economic discussion to support our conclusions.

  3. The Electron Beam Ion Source (EBIS)

    ScienceCinema (OSTI)

    Brookhaven Lab

    2010-01-08T23:59:59.000Z

    Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

  4. Flow-through ion beam source

    DOE Patents [OSTI]

    Springer, R.W.

    1997-02-11T23:59:59.000Z

    A method and an apparatus for forming a charge neutral ion beam which is useful in producing thin films of material on electrically conductive or non-conductive substrates are provided. 4 figs.

  5. BEAMS Lab at MIT: Status report

    E-Print Network [OSTI]

    Liberman, Rosa G.

    The Biological Engineering Accelerator Mass Spectrometry (BEAMS) Lab at the Massachusetts Institute of Technology is a facility dedicated to incorporating AMS into life sciences research. As such, it is focused exclusively ...

  6. First observation of beam-beam interactions in high intensity collisions at the LHC

    E-Print Network [OSTI]

    Arduini, G; Jowett, J; Laface, E; Meddahi, M; Schmidt, F

    2010-01-01T23:59:59.000Z

    For the rst time bunches were collided in the LHC with close to nominal parameters and so experienced head-on beam-beam eects comparable to those expected with the nominal LHC parameters. Among other things, this provided an opportunity to test the procedure of separating beams at IP2 to reduce the luminosity and pile-up in the ALICE experiment. We report on the observations made during these runs and related tests.

  7. AGS fixed target program with nuclear beams

    SciTech Connect (OSTI)

    Foley, K.J.

    1984-01-01T23:59:59.000Z

    The recent approval of the beam transfer line from the Tandem Van de Graaf to the AGS signals the advent of a new era of Nuclear and Particle Physics at BNL. High Energy nuclear beams are expected to be available for experiments in 1986. I will discuss the direct link between the Tandems and the AGS. Two other proposed projects, the Relativistic Heavy Ion Collider and the Synchrotron Booster, are discussed in another presentation to this conference.

  8. Ion beam processing of advanced electronic materials

    SciTech Connect (OSTI)

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B. (eds.) (California Univ., Berkeley, CA (USA); International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center; Oak Ridge National Lab., TN (USA))

    1989-01-01T23:59:59.000Z

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  9. High speed x-ray beam chopper

    DOE Patents [OSTI]

    McPherson, Armon (Oswego, IL); Mills, Dennis M. (Naperville, IL)

    2002-01-01T23:59:59.000Z

    A fast, economical, and compact x-ray beam chopper with a small mass and a small moment of inertia whose rotation can be synchronized and phase locked to an electronic signal from an x-ray source and be monitored by a light beam is disclosed. X-ray bursts shorter than 2.5 microseconds have been produced with a jitter time of less than 3 ns.

  10. Shielded beam delivery apparatus and method

    DOE Patents [OSTI]

    Hershcovitch, Ady; Montano, Rory Dominick

    2006-07-11T23:59:59.000Z

    An apparatus includes a plasma generator aligned with a beam generator for producing a plasma to shield an energized beam. An electrode is coaxially aligned with the plasma generator and followed in turn by a vortex generator coaxially aligned with the electrode. A target is spaced from the vortex generator inside a fluid environment. The electrode is electrically biased relative to the electrically grounded target for driving the plasma toward the target inside a vortex shield.

  11. Outsourcing the Design of Structural Building Components

    E-Print Network [OSTI]

    Swearingin, Adam V.

    2008-05-16T23:59:59.000Z

    component design work stateside. vi 1 Introduction The outsourcing of structural building component design has recently become available to component manufacturers in the United States. These manufacturers of metal plate connected (MPC) wood roof... of the effectiveness of outsourcing as a means of fulfilling the design requirements of MPC wood trusses. Although 1 this report does not evaluate other structural building components (i.e., i- joists, engineered wood beams and wall panels), the analysis provided...

  12. A laser-wire beam-energy and beam-profile monitor at the BNL linac

    SciTech Connect (OSTI)

    Connolly, R.; Degen, C.; DeSanto, L.; Meng, W.; Michnoff, R.; Minty, M.; Nayak, S.

    2011-03-28T23:59:59.000Z

    In 2009 a beam-energy monitor was installed in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. This device measures the energies of electrons stripped from the 40mA H{sup -} beam by background gas. Electrons are stripped by the 2.0x10{sup -7}torr residual gas at a rate of {approx}1.5x10{sup -8}/cm. Since beam electrons have the same velocities as beam protons, the beam proton energy is deduced by multiplying the electron energy by m{sub p}/m{sub e}=1836. A 183.6MeV H{sup -} beam produces 100keV electrons. In 2010 we installed an optics plates containing a laser and scanning optics to add beam-profile measurement capability via photodetachment. Our 100mJ/pulse, Q-switched laser neutralizes 70% of the beam during its 10ns pulse. This paper describes the upgrades to the detector and gives profile and energy measurements.

  13. Monte Carlo Simulations of Beam Losses in the Test Beam Line of CTF3

    E-Print Network [OSTI]

    Nebot Del Busto, E; Branger, E; Holzer, E B; Doebert, S; Lillestol, R L; Welsch, C P

    2013-01-01T23:59:59.000Z

    The Test Beam Line (TBL) of the CLIC Test Facility 3 (CTF3) aims to validate the drive beam deceleration concept of CLIC, in which the RF power requested to boost particles to multi-TeV energies is obtained via deceleration of a high current and low energy drive beam (DB). Despite a TBL beam energy (150-80 MeV) significantly lower than the minimum nominal energy of the CLIC DB (250 MeV), the pulse time structure of the TBL provides the opportunity to measure beam losses with CLIC-like DB timing conditions. In this contribution, a simulation study on the detection of beam losses along the TBL for the commissioning of the recently installed beam loss monitoring system is presented. The most likely loss locations during stable beam conditions are studied by considering the beam envelope defined by the FODO lattice as well as the emittance growth due to the deceleration process. Moreover, the optimization of potential detector locations is discussed. Several factors are considered, namely: the distance to the bea...

  14. CEBAF Beam Goes Over the Hump Highest-Energy Beam Ever Delivered...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NEWPORT NEWS, VA, May 14, 2014 - The Continuous Electron Beam Accelerator Facility (CEBAF) at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility has...

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

    E-Print Network [OSTI]

    Pieloni, Tatiana; Bay, Aurelio; Rivkin, Leonid

    2008-01-01T23:59:59.000Z

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

  16. Observations of Instabilities in the LHC Due to Missing Head-On Beam-Beam Interactions

    E-Print Network [OSTI]

    Arduini, G; Herr, W; Metral, E; Papotti, G; Pieloni, T; Buffat, X; Mounet, N

    2013-01-01T23:59:59.000Z

    We report the observation of coherent instabilities on individual bunches out of the LHC bunch train. These instabilities occurred spontaneously after several hours of stable beam while in the other cases they were related to the application of a small transverse beam separation during a luminosity optimization. Only few bunches were affected, depending on their collision schemes and following various tests we interpret these instabilities as a sudden loss of Landau damping when the tune spread from the beam-beam interaction becomes insufficient.

  17. Opto-acoustic interactions in gravitational wave detectors: Comparing flat-top beams with Gaussian beams

    SciTech Connect (OSTI)

    Gras, S.; Blair, D. G.; Ju, L. [School of Physics, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

    2010-02-15T23:59:59.000Z

    To reduce the thermal noise in the future generation of gravitational wave detectors, flat-top beams have been proposed to replace conventional Gaussian beams, so as to obtain better averaging over the Brownian motion of the test masses. Here, we present a detailed investigation of the unwanted opto-acoustic interactions in such interferometers, which can lead to the phenomenon of parametric instability. Our results show that the increased overlap of the Mesa beams with the test masses leads to approximately 3 times as many unstable modes in comparison to a similar interferometer with Gaussian beams.

  18. Electron-beam furnace with magnetic stabilization

    SciTech Connect (OSTI)

    Harker, H.R.; Knecht, J.A. II

    1986-10-07T23:59:59.000Z

    This patent describes an electron-beam comprising: a. An evacuable chamber having a port for coupling the chamber to vacuum pump means; b. a trough-shaped hearth within the chamber for holding material to be melted, the hearth having a spout for issuing a flow of molten material therefrom; c. a crucible positioned within the chamber for receiving molten material flowing from the hearth; d. one or more electron guns each for producing an energetic beam of electrons, each electron gun being positioned a relatively large distance away from the hearth and the crucible; e. magnetic beam deflection means forming an integral part of each electron gun for scanning and shaping the beam produced thereby across the hearth or the crucible; and f. magnetic means adjacent to the hearth and the crucible for producing a relatively weak magnetic field in the vicinity of the hearth and the crucible for preventing erratic deflections of the scanning electron beams without significantly altering the trajectories of such beams.

  19. Fan-beam intensity modulated proton therapy

    SciTech Connect (OSTI)

    Hill, Patrick [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242 (United States)] [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242 (United States); Westerly, David [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)] [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States); Mackie, Thomas [Medical Devices, Morgridge Institute for Research, University of Wisconsin, Madison, Wisconsin 53715 (United States)] [Medical Devices, Morgridge Institute for Research, University of Wisconsin, Madison, Wisconsin 53715 (United States)

    2013-11-15T23:59:59.000Z

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques.Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets.Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage. Overall, the sharp distal falloff of a proton depth-dose distribution was found to provide sufficient control over the dose distribution to meet objectives, even with coarse lateral resolution and channel widths as large as 2 cm. Treatment plans on both phantom and patient data show that dose conformity suffers when treatments are delivered from less than approximately ten angles. Treatment time for a sample prostate delivery is estimated to be on the order of 10 min, and neutron production is estimated to be comparable to that found for existing collimated systems.Conclusions: Fan beam proton therapy is a method of delivering intensity modulated proton therapy which may be employed as an alternative to magnetic scanning systems. A fan beam of protons can be created by a set of quadrupole magnets and modified by a dual-purpose range and intensity modulator. This can be used to deliver inversely planned treatments, with spot intensities optimized to meet user defined dose objectives. Additionally, the ability of a fan beam delivery system to effectively treat multiple beam spots simultaneously may provide advantages as compared to spot scanning deliveries.

  20. SERVICEABILITY LIMIT STATES OF CONCRETE BEAMS PRESTRESSED BY CFRP BARS

    E-Print Network [OSTI]

    reinforcements. The experimental program consisted of testing eight concrete beams prestressed by CFRP bars beams prestressed by Leadline CFRP bars were tested, in addition to two concrete beams prestressedAbstract SERVICEABILITY LIMIT STATES OF CONCRETE BEAMS PRESTRESSED BY CFRP BARS by Amr A

  1. Physics perspectives at JLab with a polarized positron beam

    SciTech Connect (OSTI)

    Voutier, Eric J.-M. [UNIV. JOSEPH FOURNIER, GRENOBLE, France

    2014-06-01T23:59:59.000Z

    Polarized positron beams are in some respect mandatory complements to polarized electron beams. The advent of the PEPPo concept for polarized positron production opens the possibility for the developement at the Jefferson Laboratory of a continuous polarized positron beam. The benefits of such a beam for hadronic structure studies are discussed, together with the technical and technological challenges to face.

  2. Electron Beam Polarization Measurement Using Touschek Lifetime Technique

    SciTech Connect (OSTI)

    Sun, Changchun; /Duke U., DFELL; Li, Jingyi; /Duke U., DFELL; Mikhailov, Stepan; /Duke U., DFELL; Popov, Victor; /Duke U., DFELL; Wu, Wenzhong; /Duke U., DFELL; Wu, Ying; /Duke U., DFELL; Chao, Alex; /SLAC; Xu, Hong-liang; /Hefei, NSRL; Zhang, Jian-feng; /Hefei, NSRL

    2012-08-24T23:59:59.000Z

    Electron beam loss due to intra-beam scattering, the Touschek effect, in a storage ring depends on the electron beam polarization. The polarization of an electron beam can be determined from the difference in the Touschek lifetime compared with an unpolarized beam. In this paper, we report on a systematic experimental procedure recently developed at Duke FEL laboratory to study the radiative polarization of a stored electron beam. Using this technique, we have successfully observed the radiative polarization build-up of an electron beam in the Duke storage ring, and determined the equilibrium degree of polarization and the time constant of the polarization build-up process.

  3. Respiratory correlated cone beam CT

    SciTech Connect (OSTI)

    Sonke, Jan-Jakob; Zijp, Lambert; Remeijer, Peter; Herk, Marcel van [Department of Radiation Oncology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands)

    2005-04-01T23:59:59.000Z

    A cone beam computed tomography (CBCT) scanner integrated with a linear accelerator is a powerful tool for image guided radiotherapy. Respiratory motion, however, induces artifacts in CBCT, while the respiratory correlated procedures, developed to reduce motion artifacts in axial and helical CT are not suitable for such CBCT scanners. We have developed an alternative respiratory correlated procedure for CBCT and evaluated its performance. This respiratory correlated CBCT procedure consists of retrospective sorting in projection space, yielding subsets of projections that each corresponds to a certain breathing phase. Subsequently, these subsets are reconstructed into a four-dimensional (4D) CBCT dataset. The breathing signal, required for respiratory correlation, was directly extracted from the 2D projection data, removing the need for an additional respiratory monitor system. Due to the reduced number of projections per phase, the contrast-to-noise ratio in a 4D scan reduced by a factor 2.6-3.7 compared to a 3D scan based on all projections. Projection data of a spherical phantom moving with a 3 and 5 s period with and without simulated breathing irregularities were acquired and reconstructed into 3D and 4D CBCT datasets. The positional deviations of the phantoms center of gravity between 4D CBCT and fluoroscopy were small: 0.13{+-}0.09 mm for the regular motion and 0.39{+-}0.24 mm for the irregular motion. Motion artifacts, clearly present in the 3D CBCT datasets, were substantially reduced in the 4D datasets, even in the presence of breathing irregularities, such that the shape of the moving structures could be identified more accurately. Moreover, the 4D CBCT dataset provided information on the 3D trajectory of the moving structures, absent in the 3D data. Considerable breathing irregularities, however, substantially reduces the image quality. Data presented for three different lung cancer patients were in line with the results obtained from the phantom study. In conclusion, we have successfully implemented a respiratory correlated CBCT procedure yielding a 4D dataset. With respiratory correlated CBCT on a linear accelerator, the mean position, trajectory, and shape of a moving tumor can be verified just prior to treatment. Such verification reduces respiration induced geometrical uncertainties, enabling safe delivery of 4D radiotherapy such as gated radiotherapy with small margins.

  4. Robust Collimation Control of Laser-Generated Ion Beam

    E-Print Network [OSTI]

    Kawata, S; Kamiyama, D; Nagashima, T; Barada, D; Gu, Y J; Li, X; Yu, Q; Kong, Q; Wang, P X

    2015-01-01T23:59:59.000Z

    The robustness of a structured collimation device is discussed for an intense-laser-produced ion beam. In this paper the ion beam collimation is realized by the solid structured collimation device, which produces the transverse electric field; the electric field contributes to reduce the ion beam transverse velocity and collimate the ion beam. Our 2.5 dimensional particle-in cell simulations demonstrate that the collimation device is rather robust against the changes in the laser parameters and the collimation target sizes. The intense short-pulse lasers are now available, and are used to generate an ion beam. The issues in the laser ion acceleration include an ion beam collimation, ion energy spectrum control, ion production efficiency, ion energy control, ion beam bunching, etc. The laser-produced ion beam tends to expand in the transverse and longitudinal directions during the ion beam propagation. The ion beam collimation is focused in this paper.

  5. Polarization of fast particle beams by collisional pumping

    DOE Patents [OSTI]

    Stearns, J.W.; Kaplan, S.N.; Pyle, R.V.; Anderson, L.W.; Schlachter, A.S.; Ruby, L.

    1984-10-19T23:59:59.000Z

    The invention relates to method and apparatus for polarizing a fast beam of particles by collisional pumping, including generating a fast beam of particles, and generating a thick electron-spin-polarized medium positioned as a target for said beam, said medium being sufficiently thick to allow said beam to interact with said medium to produce collisional pumping whereby said particle beam becomes highly polarized.

  6. Emittance growth due to beam-beam effects with a static offset in collision in the LHC

    E-Print Network [OSTI]

    Pieloni, T; Qiang, J

    2010-01-01T23:59:59.000Z

    Under nominal operational conditions, the LHC bunches experience small unavoidable offset at the collision points caused by long range beam-beam interactions. Although the geometrical loss of luminosity is small, one may have to consider an increase of the beam transverse emittance, leading to a deterioration of the experimental conditions. In this work we evaluate and understand the dynamics of beam-beam interactions with static offsets at the collision point. A study of the emittance growth as a function of the offset amplitude in collisions is presented. Moreover, we address the effects coming from the beam parameters such as the initial transverse beam size, bunch intensity and tune.

  7. The Program in Muon and Neutrino Physics: Super Beams, Cold Muon Beams,

    E-Print Network [OSTI]

    The Program in Muon and Neutrino Physics: Super Beams, Cold Muon Beams, Neutrino Factory.1 Neutrino Oscillation Physics . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 1 3.1.1 Evidence-oscillation physics at a Neutrino Factory . . . . . . . . . . . . . . . 3 - 16 iii #12;3.4 Physics that can be done

  8. Observation of bunch to bunch differences due to beam-beam effects

    E-Print Network [OSTI]

    Papotti, G; Giachino, R; Herr, W; Pieloni, T; Schaumann, M; Trad, G

    2011-01-01T23:59:59.000Z

    Due to the bunch filling schemes in the LHC the bunches experience a very different collision schedule and therefore different beam-beam effects. These differences and the effect on the performance have been observed and compared with the expectations. Possible limitations due to these effects are discussed

  9. Results on intense beam focusing and neutralization from the neutralized beam experimenta...

    E-Print Network [OSTI]

    Gilson, Erik

    Results on intense beam focusing and neutralization from the neutralized beam experimenta... P. K. Roy, S. S. Yu,b) S. Eylon, E. Henestroza, A. Anders, F. M. Bieniosek, W. G. Greenway, B. G. Logan, W, Albuquerque, New Mexico 87110-3946 R. C. Davidson, P. C. Efthimion, E. P. Gilson, and A. B. Sefkow Princeton

  10. H{sup -} beam transport experiments in a solenoid low energy beam transport

    SciTech Connect (OSTI)

    Gabor, C. [ASTeC Intense Beams Group, Rutherford Appleton Laboratory, Chilton, Didcot - Oxfordshire OX11 0QX (United Kingdom); Back, J. J. [High Energy Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Faircloth, D. C.; Lawrie, S. R.; Letchford, A. P. [ISIS Pulsed Spallation Neutron Source, Rutherford Appleton Laboratory, Chilton, Didcot - Oxfordshire OX11 0QX (United Kingdom); Izaola, Z. [ESS Bilbao, Accelerator Physics Group, Edificio Cosimet Paseo Landabarri, 2, 1 Planta. 48940 Leioa (Spain)

    2012-02-15T23:59:59.000Z

    The Front End Test Stand (FETS) is located at Rutherford Appleton Laboratory and aims for a high current, fast chopped 3 MeV H{sup -} ion beam suitable for future high power proton accelerators like ISIS upgrade. The main components of the front end are the Penning ion source, a low energy beam transport line, an radio-frequency quadrupole (RFQ) and a medium energy beam transport (MEBT) providing also a chopper section and rebuncher. FETS is in the stage of commissioning its low energy beam transport (LEBT) line consisting of three solenoids. The LEBT has to transport an H{sup -} high current beam (up to 60 mA) at 65 keV. This is the injection energy of the beam into the RFQ. The main diagnostics are slit-slit emittance scanners for each transversal plane. For optimizing the matching to the RFQ, experiments have been performed with a variety of solenoid settings to better understand the actual beam transport. Occasionally, source parameters such as extractor slit width and beam energy were varied as well. The paper also discusses simulations based on these measurements.

  11. The role of space charge compensation for ion beam extraction and ion beam transport (invited)

    SciTech Connect (OSTI)

    Spädtke, Peter, E-mail: p.spaedtke@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH (Germany)] [GSI Helmholtzzentrum für Schwerionenforschung GmbH (Germany)

    2014-02-15T23:59:59.000Z

    Depending on the specific type of ion source, the ion beam is extracted either from an electrode surface or from a plasma. There is always an interface between the (almost) space charge compensated ion source plasma, and the extraction region in which the full space charge is influencing the ion beam itself. After extraction, the ion beam is to be transported towards an accelerating structure in most cases. For lower intensities, this transport can be done without space charge compensation. However, if space charge is not negligible, the positive charge of the ion beam will attract electrons, which will compensate the space charge, at least partially. The final degree of Space Charge Compensation (SCC) will depend on different properties, like the ratio of generation rate of secondary particles and their loss rate, or the fact whether the ion beam is pulsed or continuous. In sections of the beam line, where the ion beam is drifting, a pure electrostatic plasma will develop, whereas in magnetic elements, these space charge compensating electrons become magnetized. The transport section will provide a series of different plasma conditions with different properties. Different measurement tools to investigate the degree of space charge compensation will be described, as well as computational methods for the simulation of ion beams with partial space charge compensation.

  12. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

    Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

    1995-08-08T23:59:59.000Z

    A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

  13. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

    Bogaty, John M. (Lombard, IL); Clifft, Benny E. (Park Forest, IL); Bollinger, Lowell M. (Downers Grove, IL)

    1995-01-01T23:59:59.000Z

    A beam current limiter for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity.

  14. Considerations on ODR beam-size monitoring for gamma = 1000 beams

    SciTech Connect (OSTI)

    Lumpkin, A.H.; /Fermilab; Yao, C.-Y.; /Argonne; Chiadroni, E.; Castellano, M.; /LNF, Dafne Light; Cianchi, A.; /Rome U.,Tor Vergata

    2008-04-01T23:59:59.000Z

    We discuss the feasibility of monitoring the beam size of {gamma} = 1000 beams with 3000 times more charge in a video frame time and with a more sensitive 12- to 16-bit camera than were used in the previous electron beam studies at 7 GeV at the Advanced Photon Source. Such a beam would be generated at Fermilab in a new facility in the coming years. Numerical integrations of our base model show beam size sensitivity for {+-} 20% level changes at 200- and 400-{micro}m base beam sizes. We also evaluated impact parameters of 5 {sigma}{sub y} and 12 {sigma}{sub y} for both 800-nm and 10-{micro}m observation wavelengths. The latter examples are related to a proposal to apply the technique to an {approx}0.98 TeV proton beam, and this study shows there are trades on photon intensity and beam size sensitivity to be considered at such gammas. In addition, we report on first results at {gamma} = 1800 on a superconducting rf linac.

  15. Beam halo formation from space-charge dominated beams in uniform focusing channels

    SciTech Connect (OSTI)

    O'Connell, J.S. (Booz, Allen and Hamilton, Inc., Arlington, VA (United States)); Wangler, T.P.; Mills, R.S. (Los Alamos National Lab., NM (United States)); Crandall, K.R. (AccSys Technology, Inc., Pleasanton, CA (United States))

    1993-01-01T23:59:59.000Z

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which results in a 2-component beam consisting of an inner core and an outer halo. The halo is very prominent in mismatched beams, and the potential for accelerator activation is of concern for a next generation of cw, high-power proton linacs that could be applied for intense neutron generators to process nuclear materials. We present new results about beam halo and the evolution of space-charge dominated beams from multiparticle simulation of initial laminar beams in a uniform linear focusing channel, and from a model consisting of single particle interactions with a uniform-density beam core. We study the energy gain from particle interactions with the space-charge field of the core, and we identify the resonant characteristic of this interaction as the basic cause of the separation of the beam into the two components. We identify three different particle-trajectory types, and we suggest that one of these types may lead to continuous halo growth, even after the halo is removed by collimators.

  16. Beam halo formation from space-charge dominated beams in uniform focusing channels

    SciTech Connect (OSTI)

    O`Connell, J.S. [Booz, Allen and Hamilton, Inc., Arlington, VA (United States); Wangler, T.P.; Mills, R.S. [Los Alamos National Lab., NM (United States); Crandall, K.R. [AccSys Technology, Inc., Pleasanton, CA (United States)

    1993-06-01T23:59:59.000Z

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which results in a 2-component beam consisting of an inner core and an outer halo. The halo is very prominent in mismatched beams, and the potential for accelerator activation is of concern for a next generation of cw, high-power proton linacs that could be applied for intense neutron generators to process nuclear materials. We present new results about beam halo and the evolution of space-charge dominated beams from multiparticle simulation of initial laminar beams in a uniform linear focusing channel, and from a model consisting of single particle interactions with a uniform-density beam core. We study the energy gain from particle interactions with the space-charge field of the core, and we identify the resonant characteristic of this interaction as the basic cause of the separation of the beam into the two components. We identify three different particle-trajectory types, and we suggest that one of these types may lead to continuous halo growth, even after the halo is removed by collimators.

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

    SciTech Connect (OSTI)

    Cornacchia, M; Parzen, G

    1981-01-01T23:59:59.000Z

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

  18. Method for measuring and controlling beam current in ion beam processing

    DOE Patents [OSTI]

    Kearney, Patrick A. (Livermore, CA); Burkhart, Scott C. (Livermore, CA)

    2003-04-29T23:59:59.000Z

    A method for producing film thickness control of ion beam sputter deposition films. Great improvements in film thickness control is accomplished by keeping the total current supplied to both the beam and suppressor grids of a radio frequency (RF) in beam source constant, rather than just the current supplied to the beam grid. By controlling both currents, using this method, deposition rates are more stable, and this allows the deposition of layers with extremely well controlled thicknesses to about 0.1%. The method is carried out by calculating deposition rates based on the total of the suppressor and beam currents and maintaining the total current constant by adjusting RF power which gives more consistent values.

  19. Optical parametric osicllators with improved beam quality

    DOE Patents [OSTI]

    Smith, Arlee V.; Alford, William J.

    2003-11-11T23:59:59.000Z

    An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

  20. Center for beam physics 1996-1997

    SciTech Connect (OSTI)

    NONE

    1997-02-01T23:59:59.000Z

    The Center for Beam Physics (CBP) is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Ernest Orlando Lawrence Berkeley National Laboratory of the University of California. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Special features of the Center`s program include addressing R&D issues needing long development time and providing a platform for conception, initiation, and support of institutional projects based on beams. The Center brings to bear a significant amount of diverse, complementary, and self-sufficient expertise in accelerator physics, synchrotron radiation, advanced microwave techniques, plasma physics, optics, and lasers on the forefront R&D issues in particle and photon beam research. In addition to functioning as a clearinghouse for novel ideas and concepts and related R&D (e.g., various theoretical and experimental studies in beam physics such as nonlinear dynamics, phase space control, laser-beam-plasma interaction, free-electron lasers, optics, and instrumentation), the Center provides significant support to Laboratory facilities and initiatives. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP`s outstanding team and gives a flavor of their multifaceted activities during 1996 and 1997.

  1. High power linear pulsed beam annealer

    DOE Patents [OSTI]

    Strathman, Michael D. (Concord, CA); Sadana, Devendra K. (Berkeley, CA); True, Richard B. (Sunnyvale, CA)

    1983-01-01T23:59:59.000Z

    A high power pulsed electron beam is produced in a system comprised of an electron gun having a heated cathode, control grid, focus ring, and a curved drift tube. The drift tube is maintained at a high positive voltage with respect to the cathode to accelerate electrons passing through the focus ring and to thereby eliminate space charge. A coil surrounding the curved drift tube provides a magnetic field which maintains the electron beam focused about the axis of the tube and imparts motion on electrons in a spiral path for shallow penetration of the electrons into a target. The curvature of the tube is selected so there is no line of sight between the cathode and a target holder positioned within a second drift tube spaced coaxially from the curved tube. The second tube and the target holder are maintained at a reference voltage that decelerates the electrons. A second coil surrounding the second drift tube maintains the electron beam focused about the axis of the second drift tube and compresses the electron beam to the area of the target. The target holder can be adjusted to position the target where the cross section of the beam matches the area of the target.

  2. SPALLATION NEUTRON SOURCE BEAM CURRENT MONITOR ELECTRONICS.

    SciTech Connect (OSTI)

    KESSELMAN,M.; DAWSON,W.C.

    2002-05-06T23:59:59.000Z

    This paper will discuss the present electronics design for the beam current monitor system to be used throughout the Spallation Neutron Source (SNS) under construction at Oak Ridge National Laboratory. The beam is composed of a micro-pulse structure due to the 402.5MHz RF, and is chopped into mini-pulses of 645ns duration with a 300ns gap, providing a macro-pulse of 1060 mini-pulses repeating at a 60Hz rate. Ring beam current will vary from about 15ma peak during studies, to about 50Amps peak (design to 100 amps). A digital approach to droop compensation has been implemented and initial test results presented.

  3. Beam optics issues for the antiproton decelerator

    E-Print Network [OSTI]

    Belochitskii, P; Eriksson, T; Giannini, R; Maury, S; Möhl, D; Pedersen, F

    1998-01-01T23:59:59.000Z

    The deceleration of the beam down to 0.1 GeV/c in the ring previously used as Antiproton Collector (AC) at 3.5 GeV/c, requires a number of modifications to the lattice. The insertion of the electron cooling, needed to cool the antiproton beam at low energy, implies the re-arrange-ment of quadrupoles. The optical functions then need to be readjusted in order to keep the large acceptance and to cope with the electron and stochastic cooling environ-ment. Calculations of the linear optics and of the accep-tance are reported. Tests of beam deceleration in the AC show the need for closed-orbit correction at low momentum in addition to the static correction by the movement of the quadrupoles available in the present configuration. The deceleration tests will be discussed and a correction system, which includes trim supplies on the main bending magnets, will be described.

  4. BEAM EMITTANCE MEASUREMENT TOOL FOR CEBAF OPERATIONS

    SciTech Connect (OSTI)

    Chevtsov, Pavel; Tiefenback, Michael

    2008-10-01T23:59:59.000Z

    A new software tool was created at Jefferson Lab to measure the emittance of the CEBAF electron beams. The tool consists of device control and data analysis applications. The device control application handles the work of wire scanners and writes their measurement results as well as the information about accelerator settings during these measurements into wire scanner data files. The data analysis application reads these files and calculates the beam emittance on the basis of a wire scanner data processing model. Both applications are computer platform independent but are mostly used on LINUX PCs recently installed in the accelerator control room. The new tool significantly simplifies beam emittance measurement procedures for accelerator operations and contributes to a very high availability of the CEBAF machine for the nuclear physics program at Jefferson Lab.

  5. Collective Deceleration: Toward a Compact Beam Dump

    SciTech Connect (OSTI)

    Wu, H.-C.; /Munich, Max Planck Inst. Quantenopt.; Tajima, T.; Habs, D.; /Munich, Max Planck Inst. Quantenopt. /Munich U.; Chao, A.W.; /SLAC; Meyer-ter-Vehn, J.; /Munich, Max Planck Inst. Quantenopt.

    2011-11-28T23:59:59.000Z

    With the increasing development of laser accelerators, the electron energy is already beyond GeV and even higher in near future. Conventional beam dump based on ionization or radiation loss mechanism is cumbersome and costly, also has radiological hazards. We revisit the stopping power of high-energy charged particles in matter and discuss the associated problem of beam dump from the point of view of collective deceleration. The collective stopping length in an ionized gas can be several orders of magnitude shorter than the Bethe-Bloch and multiple electromagnetic cascades stopping length in solid. At the mean time, the tenuous density of the gas makes the radioactivation negligible. Such a compact and non-radioactivating beam dump works well for short and dense bunches, which is typically generated from laser wakefield accelerator.

  6. Operational considerations on the stability of colliding beams

    E-Print Network [OSTI]

    Buffat, X; Pieloni, T

    2014-01-01T23:59:59.000Z

    While well studied in the absence of beam-beam and while colliding head-on, the stability of the LHC beams can be very critical in intermediate steps. During the squeeze, the long-range beam-beam interaction becomes a critical component of the beam's dynamics. Also, while the transverse separation at the interaction points is collapsed, the beam-beam forces change drastically, possibly deteriorating the beam's stability. Finally, during luminosity production, the configuration of the LHC in 2012 included few bunches without head-on collision in any of the interaction points having different stability properties. Stability diagrams are being evaluated numerically in these configurations in an attempt to explain instabilities observed in these phases during the 2012 proton run of the LHC.

  7. Beam-Spin Asymmetry Measurement at CLAS

    SciTech Connect (OSTI)

    Aghasyan, M

    2009-08-04T23:59:59.000Z

    Beam Single Spin Asymmetries in single neutral semi-inclusive pion electroproduction off an unpolarized hydrogen target in the deep inelastic scattering regime (Q{sup 2}>1 GeV{sup 2}, W{sup 2}>4 GeV{sup 2}) have been measured using a polarized electron beam of 5.776 GeV with the CEBAF Large Acceptance Spectrometer at the Thomas Jefferson National Accelerator Facility (JLab). The measured kinematical dependences are compared with published data and existing theoretical predictions.

  8. Polarized electron beams at milliampere average current

    SciTech Connect (OSTI)

    Poelker, Matthew [JLAB

    2013-11-01T23:59:59.000Z

    This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today's CEBAF polarized source operating at ~ 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

  9. Free Electron Lasers using `Beam by Design'

    E-Print Network [OSTI]

    Henderson, J R; McNeil, B W J

    2015-01-01T23:59:59.000Z

    Several methods have been proposed in the literature to improve Free Electron Laser output by transforming the electron phase-space before entering the FEL interaction region. By utilising `beam by design' with novel undulators and other beam changing elements, the operating capability of FELs may be further usefully extended. This paper introduces two new such methods to improve output from electron pulses with large energy spreads and the results of simulations of these methods in the 1D limit are presented. Both methods predict orders of magnitude improvements to output radiation powers.

  10. From super beams to neutrino factories

    SciTech Connect (OSTI)

    Bross, Alan; /Fermilab

    2009-11-01T23:59:59.000Z

    The Neutrino Factory, which produces an extremely intense source of flavor-tagged neutrinos from muon decays in a storage ring, arguably gives the best physics reach for CP violation, as well as virtually all parameters in the neutrino oscillation parameter space. I will briefly describe the physics capabilities of the baseline Neutrino Factory as compared to other possible future facilities ({beta}-beam and super-beam facilities), give an overview of the accelerator complex and describe in detail the current international R&D program.

  11. ATA diagnostic beam dump conceptual design

    SciTech Connect (OSTI)

    Not Available

    1981-09-01T23:59:59.000Z

    A diagnostic beam dump, able to withstand 72,000 pulses (10 kA, 50 MeV/pulse) per shift was designed and analyzed. The analysis shows that the conceptual beam dump design consisting of 80 vitreous carbon plate-foam elements is able to withstand the thermal and mechanical stresses generated. X-rays produced by bremsstrahlung are absorbed by a three element copper plate-foam x-ray absorber. Cooling between bursts of electron pulses is provided by pressurized helium.

  12. Astrophysics experiments with radioactive beams at ATLAS

    SciTech Connect (OSTI)

    Back, B. B.; Clark, J. A.; Pardo, R. C.; Rehm, K. E., E-mail: rehm@anl.gov; Savard, G. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)] [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2014-04-15T23:59:59.000Z

    Reactions involving short-lived nuclei play an important role in nuclear astrophysics, especially in explosive scenarios which occur in novae, supernovae or X-ray bursts. This article describes the nuclear astrophysics program with radioactive ion beams at the ATLAS accelerator at Argonne National Laboratory. The CARIBU facility as well as recent improvements for the in-flight technique are discussed. New detectors which are important for studies of the rapid proton or the rapid neutron-capture processes are described. At the end we briefly mention plans for future upgrades to enhance the intensity, purity and the range of in-flight and CARIBU beams.

  13. Beam instrumentation for the Tevatron Collider

    SciTech Connect (OSTI)

    Moore, Ronald S.; Jansson, Andreas; Shiltsev, Vladimir; /Fermilab

    2009-10-01T23:59:59.000Z

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders.

  14. Characterizing and Controlling Beam Losses at the LANSCE Facility

    SciTech Connect (OSTI)

    Rybarcyk, Lawrence J. [Los Alamos National Laboratory

    2012-09-12T23:59:59.000Z

    The Los Alamos Neutron Science Center (LANSCE) currently provides 100-MeV H{sup +} and 800-MeV H{sup -} beams to several user facilities that have distinct beam requirements, e.g. intensity, micropulse pattern, duty factor, etc. Minimizing beam loss is critical to achieving good performance and reliable operation, but can be challenging in the context of simultaneous multi-beam delivery. This presentation will discuss various aspects related to the observation, characterization and minimization of beam loss associated with normal production beam operations in the linac.

  15. Analysis of beam loss induced abort kicker instability

    SciTech Connect (OSTI)

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

    2012-05-20T23:59:59.000Z

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

  16. Compact two-beam push-pull free electron laser

    DOE Patents [OSTI]

    Hutton, Andrew (Yorktown, VA)

    2009-03-03T23:59:59.000Z

    An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.

  17. Further Analysis of Real Beam Line Optics From A Synthetic Beam

    SciTech Connect (OSTI)

    Ryan Bodenstein, Michael Tiefenback, Yves Roblin

    2012-07-01T23:59:59.000Z

    Standard closed-orbit techniques for Twiss parameter measurement are not applicable to the open-ended Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. The evolution of selected sets of real orbits in the accelerator models the behavior of a 'synthetic' beam. This process will be validated against beam profile-based Twiss parameter measurements and should provide the distributed optical information needed to optimize beamline tuning for an open-ended system. This work will discuss the current and future states of this technique, as well as an example of its use in the CEBAF machine.

  18. Observations of beam-beam effects at high intensities in the LHC

    E-Print Network [OSTI]

    Herr, W; Laface, E; Papotti, G; Pieloni, T; Alemany-Fernandez, R; Giachino, R; Schaumann, M

    2011-01-01T23:59:59.000Z

    First observations with colliding beams in the LHC with bunch intensities close to nominal and above are reported. In 2010 the LHC initially operated with few bunches spaced around the circumference. Beam-beam tune shifts exceeding significantly the design value have been observed. In a later stage crossing angles were introduced around the experiments to allow the collisions of bunch trains. We report the first experience with head-on as well as long range interactions of high intensity bunches and discuss the possible performance reach

  19. Contributions to the mini-workshop on beam-beam compensation in the Tevatron

    SciTech Connect (OSTI)

    Shiltsev, V.

    1998-02-01T23:59:59.000Z

    The purpose of the Workshop was to assay the current understanding of compensation of the beam-beam effects in the Tevatron with use of low-energy high-current electron beam, relevant accelerator technology, along with other novel techniques of the compensation and previous attempts. About 30 scientists representing seven institutions from four countries--FNAL, SLAC, BNL, Novosibirsk, CERN, and Dubna were in attendance. Twenty one talks were presented. The event gave firm ground for wider collaboration on experimental test of the compensation at the Tevatron collider. This report consists of vugraphs of talks given at the meeting.

  20. Neutral beam dump with cathodic arc titanium gettering

    SciTech Connect (OSTI)

    Smirnov, A.; Korepanov, S. A.; Putvinski, S. [Tri Alpha Energy Inc., Rancho Santa Margarita, California 92688 (United States); Krivenko, A. S.; Murakhtin, S. V.; Savkin, V. Ya. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

    2011-03-15T23:59:59.000Z

    An incomplete neutral beam capture can degrade the plasma performance in neutral beam driven plasma machines. The beam dumps mitigating the shine-through beam recycling must entrap and retain large particle loads while maintaining the beam-exposed surfaces clean of the residual impurities. The cathodic arc gettering, which provides high evaporation rate coupled with a fast time response, is a powerful and versatile technique for depositing clean getter films in vacuum. A compact neutral beam dump utilizing the titanium arc gettering was developed for a field-reversed configuration plasma sustained by 1 MW, 20-40 keV neutral hydrogen beams. The titanium evaporator features a new improved design. The beam dump is capable of handling large pulsed gas loads, has a high sorption capacity, and is robust and reliable. With the beam particle flux density of 5 x 10{sup 17} H/(cm{sup 2}s) sustained for 3-10 ms, the beam recycling coefficient, defined as twice the ratio of the hydrogen molecular flux leaving the beam dump to the incident flux of high-energy neutral atoms, is {approx}0.7. The use of the beam dump allows us to significantly reduce the recycling of the shine-through neutral beam as well as to improve the vacuum conditions in the machine.

  1. Proton-proton colliding beam facility ISABELLE

    SciTech Connect (OSTI)

    Hahn, H

    1980-01-01T23:59:59.000Z

    This paper attempts to present the status of the ISABELLE construction project, which has the objective of building a 400 + 400 GeV proton colliding beam facility. The major technical features of the superconducting accelerators with their projected performance are described. Progress made so far, difficulties encountered, and the program until completion in 1986 is briefly reviewed.

  2. Attenuation of Beaming Oscillations Near Neutron Stars

    E-Print Network [OSTI]

    M. Coleman Miller

    2000-07-17T23:59:59.000Z

    Observations with RXTE have revealed kilohertz quasi-periodic brightness oscillations (QPOs) from nearly twenty different neutron-star low-mass X-ray binaries (LMXBs). These frequencies often appear as a pair of kilohertz QPOs in a given power density spectrum. In many models the higher-frequency of these QPOs is a beaming oscillation at the frequency of a nearly circular orbit at some radius near the neutron star. In such models it is expected that there will also be beaming oscillations at the stellar spin frequency and at overtones of the orbital frequency, but no strong QPOs have been detected at these frequencies. We therefore examine the processes that can attenuate beaming oscillations near neutron stars, and in doing so extend the work on this subject that was initiated by the discovery of lower-frequency QPOs from LMXBs. Among our main results are (1)in a spherical scattering cloud, all overtones of rotationally modulated beaming oscillations are attenuated strongly, not just the even harmonics, and (2)it is possible to have a relatively high-amplitude modulation near the star at, e.g., the stellar spin frequency, even if no peak at that frequency is detectable in a power density spectrum taken at infinity. We discuss the application of these results to modeling of kilohertz QPOs.

  3. Focused ion beam micromilling and articles therefrom

    DOE Patents [OSTI]

    Lamartine, B.C.; Stutz, R.A.

    1998-06-30T23:59:59.000Z

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are disclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters. 6 figs.

  4. Beam current controller for laser ion source

    DOE Patents [OSTI]

    Okamura, Masahiro

    2014-10-28T23:59:59.000Z

    The present invention relates to the design and use of an ion source with a rapid beam current controller for experimental and medicinal purposes. More particularly, the present invention relates to the design and use of a laser ion source with a magnetic field applied to confine a plasma flux caused by laser ablation.

  5. Moving core beam energy absorber and converter

    DOE Patents [OSTI]

    Degtiarenko, Pavel V.

    2012-12-18T23:59:59.000Z

    A method and apparatus for the prevention of overheating of laser or particle beam impact zones through the use of a moving-in-the-coolant-flow arrangement for the energy absorbing core of the device. Moving of the core spreads the energy deposition in it in 1, 2, or 3 dimensions, thus increasing the effective cooling area of the device.

  6. Current status of the LBNE neutrino beam

    E-Print Network [OSTI]

    Moore, Craig Damon; Crowley, Cory Francis; Hurh, Patrick; Hylen, James; Lundberg, Byron; Marchionni, Alberto; McGee, Mike; Mokhov, Nikolai V; Papadimitriou, Vaia; Plunkett, Rob; Reitzner, Sarah Diane; Stefanik, Andrew M; Velev, Gueorgui; Williams, Karlton; Zwaska, Robert Miles

    2015-01-01T23:59:59.000Z

    The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab. The facility is designed to aim a beam of neutrinos toward a detector placed in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined by an amalgam of the physics goals, the Monte Carlo modeling of the facility, and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW. The LBNE Neutrino Beam has made significant changes to the initial design through consideration of numerous Value Engineering proposals and the current design is described.

  7. Temperature-dependent ion beam mixing

    SciTech Connect (OSTI)

    Rehn, L.E.; Alexander, D.E.

    1993-08-01T23:59:59.000Z

    Recent work on enhanced interdiffusion rates during ion-beam mixing at elevated temperatures is reviewed. As discussed previously, expected increase in ion-beam mixing rates due to `radiation-enhanced diffusion` (RED), i.e. the free migration of isolated vacancy and interstitial defects, is well documented in single-crystal specimens in the range of 0.4 to 0.6 of absolute melting temperature. In contrast, the increase often observed at somewhat lower temperatures during ion-beam mixing of polycrystalline specimens is not well understood. However, sufficient evidence is available to show that this increase reflects intracascade enhancement of a thermally-activated process that also occurs without irradiation. Recent evidence is presented which suggests that this process is Diffusion-induced Grain-Boundary Migration (DIGM). An important complementary conclusion is that because ion-beam mixing in single-crystal specimens exhibits no significant temperature dependence below that of RED, models that invoke only irradiation-specific phenomena, e.g., cascade-overlap, thermal-spikes, or liquid-diffusion, and hence which predict no difference in mixing behavior between single- or poly-crystalline specimens, cannot account for the existing results.

  8. Note: Vector reflectometry in a beam waveguide

    SciTech Connect (OSTI)

    Eimer, J. R.; Bennett, C. L. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Chuss, D. T.; Wollack, E. J. [NASA Goddard Space Flight Center, Code 665, Greenbelt, Maryland 20771 (United States)

    2011-08-15T23:59:59.000Z

    We present a one-port calibration technique for characterization of beam waveguide components with a vector network analyzer. This technique involves using a set of known delays to separate the responses of the instrument and the device under test. We demonstrate this technique by measuring the reflected performance of a millimeter-wave variable-delay polarization modulator.

  9. Studying of hypernuclei with nuclotron beams

    SciTech Connect (OSTI)

    Averyanov, A. V.; Avramenko, S. A.; Aksinenko, V. D.; Anikina, M. Kh.; Bazylev, S. N.; Balandin, V. P.; Batusov, Yu. A.; Belikov, Yu. A.; Borzunov, Yu. T.; Borodina, O. V.; Golokhvastov, A. I.; Golovanov, L. B. [Joint Institute for Nuclear Research (Russian Federation); Granja, C. [Czech Technical University, Institute of Experimental and Applied Physics (Czech Republic); Ivanov, A. B.; Ivanov, Yu. L.; Isupov, A. Yu. [Joint Institute for Nuclear Research (Russian Federation); Kohout, Z. [Czech Technical University (Czech Republic); Korotkova, A. M.; Litvinenko, A. G.; Lukstins, J., E-mail: juris@sunhe.jinr.r [Joint Institute for Nuclear Research (Russian Federation)

    2008-12-15T23:59:59.000Z

    A spectrometer is created to study relativistic hypernuclei produced with beams of accelerated nuclei from the Nuclotron facility (Dubna, JINR). Test runs have been carried out and the conclusion is drawn that the properties of the facility meet the requirements of the task of searching for unknown and studying poorly known neutron-rich hypernuclei.

  10. BROOKHAVEN NATIONAL LABORATORY'S HIGH FLUX BEAM REACTOR

    E-Print Network [OSTI]

    Ohta, Shigemi

    1 BROOKHAVEN NATIONAL LABORATORY'S HIGH FLUX BEAM REACTOR Compiled by S. M. Shapiro I. PICTORIAL with fiberglass insulation and a protective aluminum skin. The reactor vessel is shaped somewhat like a very large at the spherical end. It is located at the center of the reactor building and is surrounded by a lead and steel

  11. Trirotron: triode rotating beam radio frequency amplifier

    DOE Patents [OSTI]

    Lebacqz, Jean V. (Stanford, CA)

    1980-01-01T23:59:59.000Z

    High efficiency amplification of radio frequencies to very high power levels including: establishing a cylindrical cloud of electrons; establishing an electrical field surrounding and coaxial with the electron cloud to bias the electrons to remain in the cloud; establishing a rotating electrical field that surrounds and is coaxial with the steady field, the circular path of the rotating field being one wavelength long, whereby the peak of one phase of the rotating field is used to accelerate electrons in a beam through the bias field in synchronism with the peak of the rotating field so that there is a beam of electrons continuously extracted from the cloud and rotating with the peak; establishing a steady electrical field that surrounds and is coaxial with the rotating field for high-energy radial acceleration of the rotating beam of electrons; and resonating the rotating beam of electrons within a space surrounding the second field, the space being selected to have a phase velocity equal to that of the rotating field to thereby produce a high-power output at the frequency of the rotating field.

  12. Focused ion beam micromilling and articles therefrom

    DOE Patents [OSTI]

    Lamartine, Bruce C. (Los Alamos, NM); Stutz, Roger A. (Los Alamos, NM)

    1998-01-01T23:59:59.000Z

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are isclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters.

  13. Space-Charge Limits on the Transport of Ion Beams in a Long Alternating Gradient System

    E-Print Network [OSTI]

    Tiefenback, M.G.

    2011-01-01T23:59:59.000Z

    term stability of the transport of cold, high-current beams,beam. The cold-beam ideal case for this transport is called

  14. Energy spectrum control for modulated proton beams

    SciTech Connect (OSTI)

    Hsi, Wen C.; Moyers, Michael F.; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E.; Farr, Jonathan B.; Mascia, Anthony E.; Schreuder, Andries N. [Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 and University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States); Proton Therapy, Inc., Colton, California 92324 (United States); Indiana University Cyclotron Facility, Bloomington, Indiana 47408 (United States); Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 and University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States); Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 (United States); University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States) and Westdeutsches Protonentherapiezentrum, Universitaetsklinikum, Hufelandstrasse 55, 45147 Essen (Germany); Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 (United States); University Florida Proton Therapy Institute, Jacksonville, Florida 32206 (United States) and ProCure Treatment Centers, Inc., Bloomington, Indiana 47404 (United States)

    2009-06-15T23:59:59.000Z

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to {+-}21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than {+-}3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.

  15. Beam Dynamics Challenges for the ILC

    SciTech Connect (OSTI)

    Kubo, Kiyoshi; /KEK, Tsukuba; Seryi, Andrei; /SLAC; Walker, Nicholas; /DESY; Wolski, Andy; /Cockcroft Inst. Accel. Sci. Tech.

    2008-02-13T23:59:59.000Z

    The International Linear Collider (ILC) is a proposal for 500 GeV center-of-mass electron-positron collider, with a possible upgrade to {approx}1 TeV center-of-mass. At the heart of the ILC are the two {approx}12 km 1.3 GHz superconducting RF (SCRF) linacs which will accelerate the electron and positron beams to an initial maximum energy of 250 GeV each. The Global Design Effort (GDE)--responsible for the world-wide coordination of this uniquely international project--published the ILC Reference Design Report in August of 2007 [1]. The ILC outlined in the RDR design stands on a legacy of over fifteen-years of R&D. The GDE is currently beginning the next step in this ambitious project, namely an Engineering Design phase, which will culminate with the publication of an Engineering Design Report (EDR) in mid-2010. Throughout the history of linear collider development, beam dynamics has played an essential role. In particular, the need for complex computer simulations to predict the performance of the machine has always been crucial, not least because the parameters of the ILC represent in general a large extrapolation from where current machines operate today; many of the critical beam-dynamics features planned for the ILC can ultimately only be truly tested once the ILC has been constructed. It is for this reason that beam dynamics activities will continue to be crucial during the Engineering Design phase, as the available computer power and software techniques allow ever-more complex and realistic models of the machine to be developed. Complementary to the computer simulation efforts are the need for well-designed experiments at beam-test facilities, which--while not necessarily producing a direct demonstration of the ILC-like parameters for the reasons mentioned above--can provide important input and benchmarking for the computer models.

  16. Optimal beam pattern to maximize inclusion residence time in an electron beam melting hearth

    SciTech Connect (OSTI)

    Powell, A.; Pal, U. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Avyle, J. van den [Sandia National Labs., Albuquerque, NM (United States)

    1997-02-01T23:59:59.000Z

    Approximate probabilities of inclusion survival through an electron beam melting hearth are computed from nitride dissolution rates, flotation velocities, and residence times. Dissolution rates were determined by measuring shrinkage rates of pure TiN and nitrided sponge in small pools of molten titanium in an electron beam melting hearth. Flotation velocities were calculated using correlations for fluid flow around spheres, and show that particles sink or float unless their densities are extremely close to that of molten titanium. Flow field characteristics which lead to effective inclusion removal are discussed in terms of heat flux pattern required to produce them, based on the electron beam`s unique ability to impart a nearly arbitrary heat flux pattern to the melt surface.

  17. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    SciTech Connect (OSTI)

    Lee, S. Y.

    2014-04-07T23:59:59.000Z

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  18. Mechanics of nanoscale beams in liquid electrolytes: beam deflections, pull-in instability, and stiction

    E-Print Network [OSTI]

    Lee, Jae Sang

    2009-05-15T23:59:59.000Z

    -based devices, is studied in a liquid environment, including elastic energy, electrochemical work done, van der Waals work done and surface adhesion energy. We extend the classical energy method of the beam peeling for micro-electro-mechanical systems (MEMS...

  19. CRYOPUMP BEHAVIOR IN THE PRESENCE OF BEAM OR NUCLEAR RADIATION

    E-Print Network [OSTI]

    Law, P.K.

    2011-01-01T23:59:59.000Z

    beam operation and nuclear radiation environment. VariousTHE PRESENCE OF B A E M O NUCLEAR RADIATION R Peter K. LawPRESENCE OF BEAM OR NUCLEAR RADIATION Peter K. Law Contents

  20. Electron beam directed energy device and methods of using same

    DOE Patents [OSTI]

    Retsky, Michael W. (Trumbull, CT)

    2007-10-16T23:59:59.000Z

    A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

  1. axisymmetric electron beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    dominated beams F. Filbet 1 , J.-L. Lemaire Filbet, Francis 2 From x-ray telescopes to neutron scattering: using axisymmetric mirrors to focus a neutron beam CERN Preprints...

  2. BEAM DYNAMICS FOR A PHOTOINJECTED ENERGY RECOVERY LINAC AT THE...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at a rep rate of 0.43-1.3 GHz. We provide a first pass assessment of some of the beam dynamics issues that are critical to preserving the high brightness beams. 1 INTRODUCTION As...

  3. Measurement of Colliding Beam Parameters with Wide Angle Beamstrahlung

    E-Print Network [OSTI]

    Cinabro, David

    crossing, significantly affecting the Twiss matrix of the machine. The beam currents N i (t) decrease due to beam lifetime also causing the machine's Twiss matrix to drift. If the machine is perfectly sym­ metric

  4. Monumental effort: How a dedicated team completed a massive beam...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for the plasma while the second beam box performs double-duty. Its beams will raise the temperature of the plasma and will help to maintain a current in the plasma to demonstrate...

  5. Reflection High-Energy Electron Diffraction Beam-Induced Structural...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Beam-Induced Structural and Property Changes on WO3 Thin Films. Reflection High-Energy Electron Diffraction Beam-Induced Structural and Property Changes on WO3 Thin...

  6. Scanning-helium-ion-beam lithography with hydrogen silsesquioxane resist

    E-Print Network [OSTI]

    Winston, Donald

    A scanning-helium-ion-beam microscope is now commercially available. This microscope can be used to perform lithography similar to, but of potentially higher resolution than, scanning electron-beam lithography. This article ...

  7. LONGITUDINAL RESISTIVE INSTABILITIES OF INTENSE COASTING BEAMS IN PARTICLE ACCELERATORS

    E-Print Network [OSTI]

    Neil, V. Kelvin

    2008-01-01T23:59:59.000Z

    COASTING BEAMS IN PARTICLE ACCELERATORS TWO-WEEK LOAN COpyCOASTING BEAMS IN PARTICLE ACCELERATORS v. Kelyin Neil andCOASTING BEAt\\1S nr PARTICLE ACCELERATORS* V. Kelvin Neil

  8. atomic beam measurements: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frequency Physics Websites Summary: beam pipe where they are removed by a high speed pumping system. Cooling of the cell reducesTime-of-Flight Measurements in Atomic Beam Devices...

  9. atomic beam frequency: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frequency Physics Websites Summary: beam pipe where they are removed by a high speed pumping system. Cooling of the cell reducesTime-of-Flight Measurements in Atomic Beam Devices...

  10. Toward nano-accuracy in scanning beam interference lithography

    E-Print Network [OSTI]

    Montoya, Juan, 1976-

    2006-01-01T23:59:59.000Z

    Scanning beam interference lithography is a technique developed in our laboratory which uses interfering beams and a scanning stage to rapidly pattern gratings over large areas (300x300 mm2) with high precision. The ...

  11. Nanostructure fabrication by electron and ion beam patterning of nanoparticles

    E-Print Network [OSTI]

    Kong, David Sun, 1979-

    2004-01-01T23:59:59.000Z

    Two modes of energetic beam-mediated fabrication have been investigated, namely focused ion beam (FIB) direct-writing of nanoparticles, and a technique for electrostatically patterning ionized inorganic nanoparticles, ...

  12. accelerator photon beams: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    are very resistant to particle beams. Their strength deteriorates with time due to radiation damage and low-cycle thermal fatigue. In case of high intensity beams this process...

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

    E-Print Network [OSTI]

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

    2014-01-01T23:59:59.000Z

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

  14. Hydrogen removal from e-beam deposited alumina thin films by oxygen ion beam

    SciTech Connect (OSTI)

    Das, Arijeet, E-mail: arijeet@rrcat.gov.in; Mukharjee, C., E-mail: arijeet@rrcat.gov.in; Rajiv, K., E-mail: arijeet@rrcat.gov.in; Bose, Aniruddha, E-mail: arijeet@rrcat.gov.in; Singh, S. D., E-mail: arijeet@rrcat.gov.in; Rai, S. K.; Ganguli, Tapas; Joshi, S. C.; Deb, S. K. [Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Phase, D. M. [UGC-DAE Consortium for Scientific Research, Indore-452017 (India)

    2014-04-24T23:59:59.000Z

    Hydrogen interstitials and oxygen vacancies defects create energy levels in the band gap of alumina. This limits the application of alumina as a high-k dielectric. A low thermal budget method for removal of hydrogen from alumina is discussed. It is shown that bombardment of alumina films with low energy oxygen ion beam during electron beam evaporation deposition decreases the hydrogen concentration in the film significantly.

  15. Ion Chamber Arrays for the Numi Beam at Fermilab

    E-Print Network [OSTI]

    D. Indurthy; Z. Pavlovic; R. Zwaska; R. Keisler; S. Mendoza; S. Kopp; M. Proga; D. Harris; A. Marchionni; J. Morfin; A. Erwin; H. Ping; C. Velissaris; M. Bishai; M. Diwan; B. Viren; D. Naples; D. Northacker; J. McDonald

    2005-06-26T23:59:59.000Z

    The Neutrinos at the Main Injector (NuMI) beamline will deliver an intense muon neutrino beam by focusing a beam of mesons into a long evacuated decay volume. We have built 4 arrays of ionization chambers to monitor the neutrino beam direction and quality. The arrays are located at 4 stations downstream of the decay volume, and measure the remnant hadron beam and tertiary muons produced along with neutrinos in meson decays.

  16. ONE GEV BEAM ACCELERATION IN A ONE METER LONG

    E-Print Network [OSTI]

    -LINEAR OR BLOWOUT REGIME 8 C. PIC SIMULATION RESULTS 9 D. PLASMA FOCUSING STRENGTH 16 III. BEAM DELIVERY

  17. Status of Beta Beam R&D: Radioactive ion production

    E-Print Network [OSTI]

    McDonald, Kirk

    Status of Beta Beam R&D: Radioactive ion production O b h lf f EURISOL DS*/ISOLDE CERN Etam NOAH Infrastructure Action Structuring the European Research Area" g , y , Status of BetaBeam R&D AHIPA09 etam Status of BetaBeam R&D AHIPA09 etam.noah@esss.se #12;Introduction to betabeams Beta-beam proposal

  18. End to End Beam Dynamics of the ESS Linac

    E-Print Network [OSTI]

    Eshraqi, M; Celona, L; Comunian, M; Danared, H; Holm, A S; Møller, S P; Ponton, A; Stovall, J; Thomsen, H D

    2012-01-01T23:59:59.000Z

    The European Spallation Source, ESS, uses a linear accelerator to deliver the high intensity proton beam to the target station. The nominal beam power is 5 MW at an energy of 2.5 GeV. The individual accelerating structures in the linac and the transport lines are brie?y described, and the beam is tracked from the source throughout the linac to the target. This paper will present a review of the beam dynamics from the source to the target.

  19. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    E-Print Network [OSTI]

    Bakeman, M.S.

    2010-01-01T23:59:59.000Z

    ultra-short, high-peak- current, electron beams are ideal for driving a compact XUV free electron laser (

  20. ECR plasma source for heavy ion beam charge neutralization

    E-Print Network [OSTI]

    Gilson, Erik

    plasmas are being considered as a medium for charge neutralizing heavy ion beams in order to focus beyond resonance. Keywords: Plasma focus; RF plasma; Beam charge neutralization 1. INTRODUCTION A possible heavyECR plasma source for heavy ion beam charge neutralization PHILIP C. EFTHIMION,1 ERIK GILSON,1

  1. BOND PROPERTIES OF CFCC PRESTRESSING STRANDS IN PRETENSIONED CONCRETE BEAMS

    E-Print Network [OSTI]

    BOND PROPERTIES OF CFCC PRESTRESSING STRANDS IN PRETENSIONED CONCRETE BEAMS by Nolan G. Domenico plastic prestressing strands (CFCC) in pretensioned concrete beams. The bond characteristics are examined for 15.2 mm diameter and 12.5 mm diameter seven-wire CFCC strands. Ten prestressed concrete beams

  2. DEVELOPMENT OF EMITTANCE ANALYSIS SOFTWARE FOR ION BEAM CHARACTERIZATION

    SciTech Connect (OSTI)

    Padilla, M. J.; Liu, Y.

    2007-01-01T23:59:59.000Z

    Transverse beam emittance is a crucial property of charged particle beams that describes their angular and spatial spread. It is a fi gure of merit frequently used to determine the quality of ion beams, the compatibility of an ion beam with a given beam transport system, and the ability to suppress neighboring isotopes at on-line mass separator facilities. Generally a high quality beam is characterized by a small emittance. In order to determine and improve the quality of ion beams used at the Holifi eld Radioactive Ion beam Facility (HRIBF) for nuclear physics and nuclear astrophysics research, the emittances of the ion beams are measured at the off-line Ion Source Test Facilities. In this project, emittance analysis software was developed to perform various data processing tasks for noise reduction, to evaluate root-mean-square emittance, Twiss parameters, and area emittance of different beam fractions. The software also provides 2D and 3D graphical views of the emittance data, beam profi les, emittance contours, and RMS. Noise exclusion is essential for accurate determination of beam emittance values. A Self-Consistent, Unbiased Elliptical Exclusion (SCUBEEx) method is employed. Numerical data analysis techniques such as interpolation and nonlinear fi tting are also incorporated into the software. The software will provide a simplifi ed, fast tool for comprehensive emittance analysis. The main functions of the software package have been completed. In preliminary tests with experimental emittance data, the analysis results using the software were shown to be accurate.

  3. Experimental and Analytical Reexamination of Classic Concrete Beam Tests

    E-Print Network [OSTI]

    Vecchio, Frank J.

    Experimental and Analytical Reexamination of Classic Concrete Beam Tests F. J. Vecchio1 and W. Shim CE Database subject headings: Beams; Concrete; Tests; Ductility; Finite elements; Models; Shear paper describing the testing of a series of 12 reinforced concrete beams Bresler and Scordelis 1963

  4. Laser and Particle Beams http://journals.cambridge.org/LPB

    E-Print Network [OSTI]

    Liska, Richard

    Laser and Particle Beams http://journals.cambridge.org/LPB Additional services for Laser, J. Limpouch, R. Liska and P. Váchal Laser and Particle Beams / Volume 30 / Issue 03 / September 2012 of annularlaserbeamdriven plasma jets from massive planar targets. Laser and Particle Beams,30, pp 445457 doi:10.1017/S

  5. Beam test performance of the SKIROC2 ASIC

    E-Print Network [OSTI]

    Frisson, T et al.

    2015-01-01T23:59:59.000Z

    Beam tests of the first layers of CALICE silicon tungsten ECAL technological prototype were performed in April and July 2012 using 1–6 GeV electron beam at DESY. This paper presents an analysis of the SKIROC2 readout ASIC performance under test beam conditions.

  6. Beam Dynamics Challenges in High Energy Physics Accelerators!

    E-Print Network [OSTI]

    Beam Dynamics Challenges in High Energy Physics Accelerators! Alexander Valishev! University/1/2014!A. Valishev | Beam Dynamics Challenges in HEP Accelerators!2! #12;The Olympic Motto for Accelerators! 12/1/2014!A. Valishev | Beam Dynamics Challenges in HEP Accelerators!3! ENERGY INTENSITY BRIGHTNESS

  7. THE CEBAF BEAM SCRAPING MONITOR* , J. Sage, M. Wissmann

    E-Print Network [OSTI]

    THE CEBAF BEAM SCRAPING MONITOR* T. Allison , J. Sage, M. Wissmann TJNAF, Newport News, VA 23606's Continuous Electron Beam Accelerator Facility (CEBAF). The BSM acts as an early warning system that alerts CEBAF operators when the beam loss exceeds 10 to 20 nA. This allows the CEBAF operators to adjust

  8. Beams 92: Proceedings. Volume 1: Invited papers, pulsed power

    SciTech Connect (OSTI)

    Mosher, D.; Cooperstein, G. [eds.] [Naval Research Lab., Washington, DC (United States)

    1993-12-31T23:59:59.000Z

    This report contains papers on the following topics: Ion beam papers; electron beam, bremsstrahlung, and diagnostics papers; radiating Z- pinch papers; microwave papers; electron laser papers; advanced accelerator papers; beam and pulsed power applications papers; pulsed power papers; and these papers have been indexed separately elsewhere.

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

    E-Print Network [OSTI]

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

    2010-01-01T23:59:59.000Z

    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.

  10. BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT

    E-Print Network [OSTI]

    BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D­22607#erential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass measurement possible impact of the beam related systematic errors on the Higgs boson mass measurement is discussed

  11. LAPP-TECH-2013-01 DRIVE BEAM STRIPLINE BPM

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 LAPP-TECH-2013-01 DRIVE BEAM STRIPLINE BPM ELECTRONICS AND ACQUISITION. Jean-Marc Nappa, Jean- around acquisition and components tests for drive beam stripline BPM read-out. The choice of the presented stripline BPM as the drive beam position monitor is not definitive. The aim of this study

  12. Beam Position Monitor Test Stand Christopher D. Chan

    E-Print Network [OSTI]

    Hoffstaetter, Georg

    electron beams will demand better accuracy in measuring the position of the beam. Current BPM designs with improved accuracy may not be enough and entirely new designs of BPMs may be needed. This BPM test stand will help with current BPM testing and future BPM design efforts. II. CURRENT BEAM POSTION MONITORING

  13. Asymptotic description of pulsed ultrawideband electromagnetic beam field

    E-Print Network [OSTI]

    Oughstun, Kurt

    Asymptotic description of pulsed ultrawideband electromagnetic beam field propagation in dispersive of a pulsed ultrawideband electro- magnetic beam field as it propagates through a dispersive, attenuative evolution of the pulsed-beam field through a single-contour integral that is of the same form

  14. Plasticity of sandwich beam withPlasticity of sandwich beam withPlasticity of sandwich beam withPlasticity of sandwich beam with metallic foam coremetallic foam coremetallic foam coremetallic foam core

    E-Print Network [OSTI]

    Luo, Xiaoyu

    Plasticity of sandwich beam withPlasticity of sandwich beam withPlasticity of sandwich beam withPlasticity-- · Plasticity of lightweight sandwich structures, 2006 --Plasticity of lightweight sandwich structures, 2006 --Plasticity of lightweight sandwich structures, 2006 --Plasticity of lightweight sandwich structures, 2006

  15. Performance Limitations in the LHC due to Parasitic Beam-beam Encounters- Parameter Dependence, Scaling, and PACMAN Effects

    E-Print Network [OSTI]

    Giachino, R; Metral, E; Papotti, G; Pieloni, T; Trad, G; Buffat, X; Kaltchev, D

    2013-01-01T23:59:59.000Z

    We studied possible limitations due to the long-range beam-beam effects in the LHC. With a large number of bunches and collisions in all interaction points, we have reduced the crossing angles (separation) to enhance longrange beam-beam effects to evaluate their influence on dynamic aperture and losses. Different ?*, number of bunches and intensities have been used in several dedicated experiments and allow the test of the expected scaling laws.

  16. Computationally efficient description of relativistic electron beam transport in collisionless plasma

    E-Print Network [OSTI]

    Kaganovich, Igor

    Computationally efficient description of relativistic electron beam transport in collisionless and relativistic electron beam transport in collisionless background plasma is developed. Beam electrons of the Weibel instability are derived for the cold and finite-temperature beams. © 2007 American Institute

  17. A photoelastic study of a simply supported rectangular beam loaded by a round pin through the center of the beam

    E-Print Network [OSTI]

    Morgan, Jerry Don

    1964-01-01T23:59:59.000Z

    . fferent Beams 40 20. Maximum Tensile Stress at Edge of Hole for Two Different Beams ai Three Different Spans 41 LIST OF SYMBOLS ~Sbo 1 Dimension D Distance from the neutral axis to the edge of the beam Diameter of the hole Nodal fringe value...

  18. Optical Beam Jitter Control for the NPS HEL Beam Control Jae Jun Kim, Masaki Nagashima, and Brij. N. Agrawal

    E-Print Network [OSTI]

    Optical Beam Jitter Control for the NPS HEL Beam Control Testbed Jae Jun Kim, Masaki Nagashima, and Brij. N. Agrawal Naval Postgraduate School, Monterey, CA, 93943 In this paper, an optical beam jitter hardware is developed and integrated on the testbed to realize the strap-down IRU jitter compensation

  19. High gradient lens for charged particle beam

    DOE Patents [OSTI]

    Chen, Yu-Jiuan

    2014-04-29T23:59:59.000Z

    Methods and devices enable shaping of a charged particle beam. A dynamically adjustable electric lens includes a series of alternating a series of alternating layers of insulators and conductors with a hollow center. The series of alternating layers when stacked together form a high gradient insulator (HGI) tube to allow propagation of the charged particle beam through the hollow center of the HGI tube. A plurality of transmission lines are connected to a plurality of sections of the HGI tube, and one or more voltage sources are provided to supply an adjustable voltage value to each transmission line of the plurality of transmission lines. By changing the voltage values supplied to each section of the HGI tube, any desired electric field can be established across the HGI tube. This way various functionalities including focusing, defocusing, acceleration, deceleration, intensity modulation and others can be effectuated on a time varying basis.

  20. Polarized electron beams at milliampere average current

    SciTech Connect (OSTI)

    Poelker, M. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2013-11-07T23:59:59.000Z

    This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today’s CEBAF polarized source operating at ? 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

  1. Counting molecular-beam grown graphene layers

    SciTech Connect (OSTI)

    Plaut, Annette S. [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom)] [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Wurstbauer, Ulrich [Department of Physics, Columbia University, New York, New York 10027 (United States)] [Department of Physics, Columbia University, New York, New York 10027 (United States); Pinczuk, Aron [Department of Physics, Columbia University, New York, New York 10027 (United States) [Department of Physics, Columbia University, New York, New York 10027 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Garcia, Jorge M. [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain)] [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain); Pfeiffer, Loren N. [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)] [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)

    2013-06-17T23:59:59.000Z

    We have used the ratio of the integrated intensity of graphene's Raman G peak to that of the silicon substrate's first-order optical phonon peak, accurately to determine the number of graphene layers across our molecular-beam (MB) grown graphene films. We find that these results agree well both, with those from our own exfoliated single and few-layer graphene flakes, and with the results of Koh et al.[ACS Nano 5, 269 (2011)]. We hence distinguish regions of single-, bi-, tri-, four-layer, etc., graphene, consecutively, as we scan coarsely across our MB-grown graphene. This is the first, but crucial, step to being able to grow, by such molecular-beam-techniques, a specified number of large-area graphene layers, to order.

  2. The Scheme of Beam Synchronization in MEIC

    SciTech Connect (OSTI)

    Zhang, Yuhong; Derbenev, Yaroslav S.; Hutton, Andrew M.

    2013-06-01T23:59:59.000Z

    Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme.

  3. Center for Beam Physics: 1994--95

    SciTech Connect (OSTI)

    NONE

    1995-05-01T23:59:59.000Z

    The Center for Beam Physics is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Lawrence Berkeley Laboratory of the University of California. At the heart of the Center`s mission is a fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Dedicated to exploring the frontiers of particle and photon beam physics, its primary mission is to promote the science and technology of the production, manipulation, storage, and control of systems of charged particles and photons. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP`s team and gives a brief review of the multifaceted activities during 1994 and 1995.

  4. ROTATIONAL DOPPLER BEAMING IN ECLIPSING BINARIES

    SciTech Connect (OSTI)

    Groot, Paul J., E-mail: pgroot@astro.ru.nl [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

    2012-01-20T23:59:59.000Z

    In eclipsing binaries the stellar rotation of the two components will cause a rotational Doppler beaming during eclipse ingress and egress when only part of the eclipsed component is covered. For eclipsing binaries with fast spinning components this photometric analog of the well-known spectroscopic Rossiter-McLaughlin effect can exceed the strength of the orbital effect. Example light curves are shown for a detached double white dwarf binary, a massive O-star binary and a transiting exoplanet case, similar to WASP-33b. Inclusion of the rotational Doppler beaming in eclipsing systems is a prerequisite for deriving the correct stellar parameters from fitting high-quality photometric light curves and can be used to determine stellar obliquities as well as, e.g., an independent measure of the rotational velocity in those systems that may be expected to be fully synchronized.

  5. Monte Carlo beam capture and charge breeding simulation

    SciTech Connect (OSTI)

    Kim, J.S.; Liu, C.; Edgell, D.H.; Pardo, R. [FAR-TECH, Inc., 10350 Science Center Drive, San Diego, California 92121 (United States); FAR-TECH, Inc., 10350 Science Center Drive, San Diego, California 92121 (United States) and University of Rochester, Rochester, New York (United States); Argonne National Laboratory, Argonne, Illinois (United States)

    2006-03-15T23:59:59.000Z

    A full six-dimensional (6D) phase space Monte Carlo beam capture charge-breeding simulation code examines the beam capture processes of singly charged ion beams injected to an electron cyclotron resonance (ECR) charge breeder from entry to exit. The code traces injected beam ions in an ECR ion source (ECRIS) plasma including Coulomb collisions, ionization, and charge exchange. The background ECRIS plasma is modeled within the current frame work of the generalized ECR ion source model. A simple sample case of an oxygen background plasma with an injected Ar +1 ion beam produces lower charge breeding efficiencies than experimentally obtained. Possible reasons for discrepancies are discussed.

  6. BEAM SIMULATIONS USING VIRTUAL DIAGNOSTICS FOR THE DRIVER LINAC

    SciTech Connect (OSTI)

    R. C. York; X. Wu; Q. Zhao

    2011-12-21T23:59:59.000Z

    End-to-end beam simulations for the driver linac have shown that the design meets the necessary performance requirements including having adequate transverse and longitudinal acceptances. However, to achieve reliable operational performance, the development of appropriate beam diagnostic systems and control room procedures are crucial. With limited R&D funding, beam simulations provide a cost effective tool to evaluate candidate beam diagnostic systems and to provide a critical basis for developing early commissioning and later operational activities. We propose to perform beam dynamic studies and engineering analyses to define the requisite diagnostic systems of the driver linac and through simulation to develop and test commissioning and operational procedures.

  7. Method for changing the cross section of a laser beam

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Seppala, Lynn (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A technique is disclosed herein in which a circular optical beam, for example a copper vapor laser (CVL) beam, is converted to a beam having a profile other than circular, e.g. square or triangular. This is accomplished by utilizing a single optical mirror having a reflecting surface designed in accordance with a specifically derived formula in order to make the necessary transformation, without any substantial light loss and without changing substantially the intensity profile of the circular beam which has a substantially uniform intensity profile. In this way, the output beam can be readily directed into the dye cell of a dye laser.

  8. Method for changing the cross section of a laser beam

    DOE Patents [OSTI]

    Sweatt, W.C.; Seppala, L.

    1995-12-05T23:59:59.000Z

    A technique is disclosed herein in which a circular optical beam, for example a copper vapor laser (CVL) beam, is converted to a beam having a profile other than circular, e.g. square or triangular. This is accomplished by utilizing a single optical mirror having a reflecting surface designed in accordance with a specifically derived formula in order to make the necessary transformation, without any substantial light loss and without changing substantially the intensity profile of the circular beam which has a substantially uniform intensity profile. In this way, the output beam can be readily directed into the dye cell of a dye laser. 4 figs.

  9. Analysis of RHIC beam dump pre-fires

    SciTech Connect (OSTI)

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

    2011-03-28T23:59:59.000Z

    It has been speculated that the beam may cause instability of the RHIC Beam Abort Kickers. In this study, we explore the available data of past beam operations, the device history of key modulator components, and the radiation patterns to examine the correlations. The RHIC beam abort kicker system was designed and built in the 90's. Over last decade, we have made many improvements to bring the RHIC beam abort kicker system to a stable operational state. However, the challenge continues. We present the analysis of the pre-fire, an unrequested discharge of kicker, issues which relates to the RHIC machine safety and operational stability.

  10. Beam Phase and Energy Tolerances in the CLIC RTML

    E-Print Network [OSTI]

    Stulle, Frank

    2011-01-01T23:59:59.000Z

    Tight beam phase and energy constraints are imposed on the CLIC ring to main linac transport (RTML) to achieve the demanded performance of the following main linac and at the interaction point. A major issue will be energy jitter which is converted by the bunch compressor chicanes into beam phase jitter. Constraints on the two bunch compression stages, the booster linac and the incoming beam are evaluated. As an alternative to the current second stage of bunch compression a beam line is studied which inherently prevents incoming energy jitter from becoming beam phase jitter while preserving the required bunch compression.

  11. Viewing device for electron-beam equipment

    SciTech Connect (OSTI)

    Nasyrov, R.S.

    1985-06-01T23:59:59.000Z

    Viewing devices are used to observe melting, welding, and so on in vacuum systems, an it is necessary to protect the windows from droplets and vapor. A viewing device for electron-beam equipment is described in which the viewing tube and mounting flange are made as a tubular ball joint enclosed in a steel bellows, which render the viewing device flexible. Bending the viewing tube in the intervals between observations protects the viewing window from sputtering and from drops of molten metal.

  12. Concerning the Facility for Rare Isotope Beams

    ScienceCinema (OSTI)

    Symons, James

    2013-05-29T23:59:59.000Z

    James Symons, Nuclear Science Division Director at Lawrence Berkeley Lab, and Daniela Leitner, head of operations at Berkeley Lab's 88-Inch Cyclotron, discuss major contributions to the new Facility for Rare Isotope Beams (FRIB) at Michigan State University, including ion source, which will based on the VENUS source built for the 88-Inch Cyclotron, and the GRETA gamma-ray detector now under construction there.

  13. Future possibilities with Fermilab neutrino beams

    SciTech Connect (OSTI)

    Saoulidou, Niki

    2008-01-01T23:59:59.000Z

    We will start with a brief overview of neutrino oscillation physics with emphasis on the remaining unanswered questions. Next, after mentioning near future reactor and accelerator experiments searching for a non zero {theta}{sub 13}, we will introduce the plans for the next generation of long-baseline accelerator neutrino oscillation experiments. We will focus on experiments utilizing powerful (0.7-2.1 MW) Fermilab neutrino beams, either existing or in the design phase.

  14. Jacobi equations and particle accelerator beam dynamics

    E-Print Network [OSTI]

    Ricardo Gallego Torrome

    2012-03-27T23:59:59.000Z

    A geometric formulation of the linear beam dynamics in accelerator physics is presented. In particular, it is proved that the linear transverse and longitudinal dynamics can be interpret geometrically as an approximation to the Jacobi equation of an affine averaged Lorentz connection. We introduce a specific notion reference trajectory as integral curves of the main velocity vector field. A perturbation caused by the statistical nature of the bunch of particles is considered.

  15. COMPUTED TOMOGRAPHIC RECONSTRUCTION OF BEAM PROFILES WITH A MULTI-WIRE CHAMBER

    E-Print Network [OSTI]

    Alonso, J.R.

    2010-01-01T23:59:59.000Z

    the beam with a small ion chamber. Both of these techniquesstudies of the chamber. A for heav;' ion radiotherapy beam

  16. Pushing beam currents to the limit

    SciTech Connect (OSTI)

    Stevenson, N.R.; Nortier, F.M.; Gelbart, W.Z.; Bloemhard, R.; Elzen, R. van den; Hunt, C.; Lofvendahl, J.; Orzechowski, J. [TRIUMF, British Columbia (Canada)

    1994-12-31T23:59:59.000Z

    One of the cyclotron systems running at the Nordion Int. radioisotope production facility at TRIUMF is the EBCO TR30. This cyclotron produces up to 250 {mu}A on each of two beamlines simultaneously. Two solid (for the production of {sup 201}Tl, {sup 57}Co, {sup 67}Ga and {sup 111}In) and a gaseous (for producing {sup 123}I) target station are in routine operation on this facility. Since future projections indicate a greater demand for reliable radioisotope production there is a program underway to increase the output of the facility to double the present level. One way that this is being achieved is through a careful thermal analysis of the solid target system to maximize its performance. In conjunction with this, the authors have developed and tested a 500 {mu}A upgrade of the solid target system. Gas targets are being investigated for possible ways of increasing the efficiency of production via rotating/sweeping beams which allow higher beam currents. Finally, the TR30 cyclotron is being upgraded to deliver 50-100% more beam on target. By pushing both the cyclotron and target technology to the limit will produce significantly higher levels of radioisotopes than many other comparable facilities.

  17. A scanning wire beam profile monitor

    SciTech Connect (OSTI)

    Steinbach, Ch.; van Rooij, M.

    1985-10-01T23:59:59.000Z

    The transverse profile of the circulating beam of the CERN PS is obtained from the interaction between the particles and a thin wire rapidly moving through it. The signal from a secondary particles monitor or the secondary emission current of the wire is sampled against the wire position every four beam revolutions in the machine. A stand-alone desk computer performs the real-time control of the wire displacement as well as the acquisitions and calculations necessary to display the profiles and the corresponding emittances. A traversing speed of 20 m/s in the measurement area is reached, using a high torque motor rigidly linked to a U shaped wire holder. All elements are carefully designed and chosen for low inertia and minimum load on the wire. This enables measurements of high energy beams of more than 10/sup 13/ p/p in the PS with negligible emittance blow-up due to multiple scattering. This blow-up is still acceptable at injection energy. A link to the PS main computer allows operation from any one of the main consoles.

  18. Energy Production Demonstrator for Megawatt Proton Beams

    E-Print Network [OSTI]

    Vitaly S. Pronskikh; Nikolai Mokhov; Igor Novitski; Sergey I. Tyutyunnikov

    2014-07-16T23:59:59.000Z

    A preliminary study of the Energy Production Demonstrator (EPD) concept - a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming - is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated with the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5 to 120 GeV. This study shows that the proton energy range of 2 to 4 GeV is optimal for both a natU EPD and the tungsten-based testing station that would be the most suitable for proton accelerator facilities. Conservative estimates, not including breeding and fission of plutonium, based on the simulations suggest that the proton beam current of 1 mA will be sufficient to produce 1 GW of thermal output power with the natU EPD while supplying < 8% of that power to operate the accelerator. The thermal analysis shows that the concept considered has a problem due to a possible core meltdown; however, a number of approaches (a beam rastering, in first place) are suggested to mitigate the issue. The efficiency of the considered EPD as a Materials Test Station (MTS) is also evaluated in this study.

  19. Muon Beam Helical Cooling Channel Design

    SciTech Connect (OSTI)

    Johnson, Rolland; Ankenbrandt, Charles; Flanagan, G.; Kazakevich, G.M.; Marhauser, Frank; Neubauer, Michael; Roberts, T.; Yoshikawa, C.; Derbenev, Yaroslav; Morozov, Vasiliy; Kashikhin, V.S.; Lopes, Mattlock; Tollestrup, A.; Yonehara, Katsuya; Zloblin, A.

    2013-06-01T23:59:59.000Z

    The Helical Cooling Channel (HCC) achieves effective ionization cooling of the six-dimensional (6d) phase space of a muon beam by means of a series of 21st century inventions. In the HCC, hydrogen-pressurized RF cavities enable high RF gradients in strong external magnetic fields. The theory of the HCC, which requires a magnetic field with solenoid, helical dipole, and helical quadrupole components, demonstrates that dispersion in the gaseous hydrogen energy absorber provides effective emittance exchange to enable longitudinal ionization cooling. The 10-year development of a practical implementation of a muon-beam cooling device has involved a series of technical innovations and experiments that imply that an HCC of less than 300 m length can cool the 6d emittance of a muon beam by six orders of magnitude. We describe the design and construction plans for a prototype HCC module based on oxygen-doped hydrogen-pressurized RF cavities that are loaded with dielectric, fed by magnetrons, and operate in a superconducting helical solenoid magnet.

  20. Dynamic Bowtie for Fan-beam CT

    E-Print Network [OSTI]

    Liu, Fenglin; Cong, Wenxiang; Hsieh, Scott; Pelc, Norbert

    2013-01-01T23:59:59.000Z

    A bowtie is a filter used to shape an x-ray beam and equalize its flux reaching different detector channels. For development of spectral CT with energy-discriminative photon-counting (EDPC) detectors, here we propose and evaluate a dynamic bowtie for performance optimization based on a patient model or a scout scan. Our dynamic bowtie modifies an x-ray beam intensity profile by mechanical rotation and adaptive adjustment of the x-ray source flux. First, a mathematical model for dynamic bowtie filtering is established for an elliptical section in fan-beam geometry, and the contour of the optimal bowtie is derived. Then, numerical simulation is performed to compare the performance of the dynamic bowtie in the cases of an ideal phantom and a realistic cross-section relative to the counterparts without any bowtie and with a fixed bowtie respectively. Our dynamic bowtie can equalize the expected numbers of photons in the case of an ideal phantom. In practical cases, our dynamic bowtie can effectively reduce the dy...

  1. Head-On and Long Range Beam-Beam Interactions in the LHC: Effective Tune Spread and Beam Stability Due to Landau Damping

    E-Print Network [OSTI]

    Buffat, X; Métral, E; Mounet, N; Pieloni, T

    2013-01-01T23:59:59.000Z

    We discuss the Landau damping of coherent instabilities in the presence of betatron tune spread. This tune spread can originate from dedicated non-linear magnets such as octupoles, or through the beam-beam interaction. In the latter case we have to distinguish the contribution from head- on and parasitic beam-beam interactions and the collision pattern of different bunches plays an important role. The interplay of these sources of tune spread and the resulting stability is discussed for the case of the LHC.

  2. Systems and methods of varying charged particle beam spot size

    DOE Patents [OSTI]

    Chen, Yu-Jiuan

    2014-09-02T23:59:59.000Z

    Methods and devices enable shaping of a charged particle beam. A modified dielectric wall accelerator includes a high gradient lens section and a main section. The high gradient lens section can be dynamically adjusted to establish the desired electric fields to minimize undesirable transverse defocusing fields at the entrance to the dielectric wall accelerator. Once a baseline setting with desirable output beam characteristic is established, the output beam can be dynamically modified to vary the output beam characteristics. The output beam can be modified by slightly adjusting the electric fields established across different sections of the modified dielectric wall accelerator. Additional control over the shape of the output beam can be excreted by introducing intentional timing de-synchronization offsets and producing an injected beam that is not fully matched to the entrance of the modified dielectric accelerator.

  3. Development of the Holifield Radioactive Ion Beam Facility

    SciTech Connect (OSTI)

    Tatum, B.A.

    1997-08-01T23:59:59.000Z

    The Holifield Radioactive Ion Beam Facility (HRIBF) construction project has been completed and the first radioactive ion beam has been successfully accelerated. The project, which began in 1992, has involved numerous facility modifications. The Oak Ridge Isochronous Cyclotron has been converted from an energy booster for heavy ion beams to a light ion accelerator with internal ion source. A target-ion source and mass analysis system have been commissioned as key components of the facility`s radioactive ion beam injector to the 25MV tandem electrostatic accelerator. Beam transport lines have been completed, and new diagnostics for very low intensity beams have been developed. Work continues on a unified control system. Development of research quality radioactive beams for the nuclear structure and nuclear astrophysics communities continues. This paper details facility development to date.

  4. Linac4 low energy beam measurements with negative hydrogen ions

    SciTech Connect (OSTI)

    Scrivens, R., E-mail: richard.scrivens@cern.ch; Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T. [CERN, 1211 Geneva 23 (Switzerland)] [CERN, 1211 Geneva 23 (Switzerland)

    2014-02-15T23:59:59.000Z

    Linac4, a 160 MeV normal-conducting H{sup ?} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup ?} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  5. Linac4 Low Energy Beam Measurements with Negative Hydrogen

    E-Print Network [OSTI]

    Scrivens, R; Crettiez, O; Dimov, V; Gerard, D; Granemann Souza, E; Guida, R; Hansen, J; Lallement, J B; Lettry, J; Lombardi, A; Midttun, O; Pasquino, C; Raich, U; Riffaud, B; Roncarolo, F; Valerio-Lizarraga, C A; Wallner, J; Yarmohammadi Satri, M; Zickler, T

    2013-01-01T23:59:59.000Z

    Linac4, a 160 MeV normal-conducting H- linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H- beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  6. Hybrid monitor for both beam position and tilt of pulsed high-current beams

    SciTech Connect (OSTI)

    Pang, J., E-mail: jpang-caep@foxmail.com; He, X.; Ma, C.; Zhao, L.; Li, Q.; Dai, Z. [Key Laboratory of Pulsed Power, Institute of Fluid Physics, CAEP, P.O. Box 919-106, Mianyang 621900 (China)

    2014-09-15T23:59:59.000Z

    A Hybrid beam monitor, integrated with both azimuthal and axial B-dot probes, was designed for simultaneous measurement of both beam position and beam angle for pulsed high-current beams at the same location in beam pipe. The output signals of axial B-dot probes were found to be mixed with signals caused by transverse position deviation. In order to eliminate the unwanted signals, an elimination method was developed and its feasibility tested on a 50-? coaxial line test stand. By this method, a waveform, shape-like to that of input current and proportional to the tilt angle, was simulated and processed by following integration step to achieve the tilt angle. The tests showed that the measurement error of displacement and tilt angle less than 0.3 mm and 1.5 mrad, respectively. The latter error could be reduced with improved probes by reducing the inductance of the axial B-dot probe, but the improvement reached a limit due to some unknown systemic mechanism.

  7. High speed measurements of neutral beam turn-on and impact of beam modulation on measurements of ion density

    SciTech Connect (OSTI)

    Grierson, B. A., E-mail: bgriers@pppl.gov; Grisham, L. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Burrell, K. H.; Crowley, B.; Scoville, J. T. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

    2014-10-15T23:59:59.000Z

    Modulation of neutral beams on tokamaks is performed routinely, enabling background rejection for active spectroscopic diagnostics, and control of injected power and torque. We find that there exists an anomalous initial transient in the beam neutrals delivered to the tokamak that is not accounted for by the accelerator voltage and power supply current. Measurements of the charge-exchange and beam photoemission on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] at high speed (200 ?s) reveal that the energy of the beam neutrals is constant, but the density of beam neutrals displays dramatic variation in the first 2–3 ms following beam turn-on. The impact of this beam density variation on inferred ion densities and impurity transport is presented, with suggested means to correct for the anomalous transient.

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

    E-Print Network [OSTI]

    Trad, G

    2014-01-01T23:59:59.000Z

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

  9. Influence of laser beam profile on electromagnetically induced absorption

    SciTech Connect (OSTI)

    Cuk, S. M.; Radonjic, M.; Krmpot, A. J.; Nikolic, S. N.; Grujic, Z. D.; Jelenkovic, B. M. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

    2010-12-15T23:59:59.000Z

    We compared, experimentally and theoretically, Hanle electromagnetically induced absorption (EIA) obtained using Gaussian and {Pi}-shaped laser beams 3 mm in diameter. The study was done by measuring the transmission of a laser locked to the F{sub g}=2{yields}F{sub e}=3 transition at the D{sub 2} line of {sup 87}Rb in a vacuum cell. EIA linewidths obtained for the two laser profiles were significantly different in the range of laser intensities 1-4 mW/cm{sup 2}. EIA with the {Pi}-shaped laser beam has a broad intensity maximum and linewidths larger than those obtained with the Gaussian beam profile. We also studied Hanle EIA by measuring the transmission of selected segments of the entire laser beam by placing a small movable aperture in front of the detector. Waveforms so obtained in Hanle EIA resonances were strongly influenced both by the radial distance of the transmitted segment from the beam center and by the radial profile of the laser beam. We show that outer regions of Gaussian beam, and central regions of the {Pi}-shaped beam generate the narrowest lines. The different behaviors of EIA owing to different beam profiles revealed by both theory and experiment indicate the importance of the radial profile of the laser beam for proper modeling of coherent effects in alkali metal vapors.

  10. Beam conditioner for free electron lasers and synchrotrons

    DOE Patents [OSTI]

    Liu, H.; Neil, G.R.

    1998-09-08T23:59:59.000Z

    A focused optical has been used to introduce an optical pulse, or electromagnetic wave, collinear with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM{sub 10} mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron. 4 figs.

  11. Beam conditioner for free electron lasers and synchrotrons

    DOE Patents [OSTI]

    Liu, Hongxiu (Williamsburg, VA); Neil, George R. (Williamsburg, VA)

    1998-01-01T23:59:59.000Z

    A focused optical is been used to introduce an optical pulse, or electromagnetic wave, colinearly with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM.sub.10 mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron.

  12. Electron beam diagnostic system using computed tomography and an annular sensor

    DOE Patents [OSTI]

    Elmer, John W.; Teruya, Alan T.

    2014-07-29T23:59:59.000Z

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  13. PURIFICATION OF IRIDIUM BY ELECTRON BEAM MELTING

    SciTech Connect (OSTI)

    Ohriner, Evan Keith [ORNL

    2008-01-01T23:59:59.000Z

    The purification of iridium metal by electron beam melting has been characterized for 48 impurity elements. Chemical analysis was performed by glow discharge mass spectrographic (GDMS) analysis for all elements except carbon, which was analyzed by combustion. The average levels of individual elemental impurities in the starting powder varied from 37 g/g to 0.02 g/g. The impurity elements Li, Na, Mg, P, S, Cl, K, Ca, Mn, Co, Ni, Cu, Zn, As, Pd, Ag, Cd, Sn, Sb, Te, Ba, Ce, Tl, Pb, and Bi were not detectable following the purification. No significant change in concentration of the elements Ti, V, Zr, Nb, Mo, and Re was found. The elements B, C, Al, Si, Cr, Fe, Ru, Rh, and Pt were partially removed by vaporization during electron beam melting. Langmuir's equation for ideal vaporization into a vacuum was used to calculate for each impurity element the expected ratio of impurity content after melting to that before melting. Equilibrium vapor pressures were calculated using Henry's law, with activity coefficients obtained from published data for the elements Fe, Ti, and Pt. Activity coefficients were estimated from enthalpy data for Al, Si, V, Cr, Mn, Co, Ni, Zr, Nb, Mo, and Hf and an ideal solution model was used for the remaining elements. The melt temperature was determined from measured iridium weight loss. Excellent agreement was found between measured and calculated impurity ratios for all impurity elements. The results are consistent with some localized heating of the melt pool due to rastering of the electron beam, with an average vaporization temperature of 3100 K as compared to a temperature of 2965 K calculated for uniform heating of the melt pool. The results are also consistent with ideal mixing in the melt pool.

  14. TRACKING CODE DEVELOPMENT FOR BEAM DYNAMICS OPTIMIZATION

    SciTech Connect (OSTI)

    Yang, L.

    2011-03-28T23:59:59.000Z

    Dynamic aperture (DA) optimization with direct particle tracking is a straight forward approach when the computing power is permitted. It can have various realistic errors included and is more close than theoretical estimations. In this approach, a fast and parallel tracking code could be very helpful. In this presentation, we describe an implementation of storage ring particle tracking code TESLA for beam dynamics optimization. It supports MPI based parallel computing and is robust as DA calculation engine. This code has been used in the NSLS-II dynamics optimizations and obtained promising performance.

  15. Particle beam generator using a radioactive source

    DOE Patents [OSTI]

    Underwood, David G. (Naperville, IL)

    1993-01-01T23:59:59.000Z

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  16. Decarburization of uranium via electron beam processing

    SciTech Connect (OSTI)

    McKoon, R H

    1998-10-23T23:59:59.000Z

    For many commercial and military applications, the successive Vacuum Induction Melting of uranium metal in graphite crucibles results in a product which is out of specification in carbon. The current recovery method involves dissolution of the metal in acid and chemical purification. This is both expensive and generates mixed waste. A study was undertaken at Lawrence Livermore National Laboratory to investigate the feasibility of reducing the carbon content of uranium metal using electron beam techniques. Results will be presented on the rate and extent of carbon removal as a function of various operating parameters.

  17. Reflective echo tomographic imaging using acoustic beams

    DOE Patents [OSTI]

    Kisner, Roger; Santos-Villalobos, Hector J

    2014-11-25T23:59:59.000Z

    An inspection system includes a plurality of acoustic beamformers, where each of the plurality of acoustic beamformers including a plurality of acoustic transmitter elements. The system also includes at least one controller configured for causing each of the plurality of acoustic beamformers to generate an acoustic beam directed to a point in a volume of interest during a first time. Based on a reflected wave intensity detected at a plurality of acoustic receiver elements, an image of the volume of interest can be generated.

  18. Particle beam generator using a radioactive source

    DOE Patents [OSTI]

    Underwood, D.G.

    1993-03-30T23:59:59.000Z

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  19. A numerical approach to beam deflections

    E-Print Network [OSTI]

    Lovell, Joel Ernest

    1974-01-01T23:59:59.000Z

    , ]+I ~ g-I EI vhich, solved for y , yields y = (y + v 1 ? ? hx2) 1 2 3 4 5 n-2, n-1 n Fig. 1 Beam This solution for y in terms of y +1 yields a set of' simultaneous equations which must be solved in order to define the deflection curve...-2~ ? + ? ? + i ? 4x2 i=1 it is found that 13 p-i or + + From this ecuation a table can be constructed showing the factors by which the various station M/EI values are to be multiplied such that they will then acid to give the station dei...

  20. Two-Beam Instability in Electron Cooling

    SciTech Connect (OSTI)

    Burov, Alexey V.; /Fermilab

    2006-04-01T23:59:59.000Z

    The drift motion of cooling electrons makes them able to respond to transverse perturbations of a cooled ion beam. This response may lead to dipole or quadrupole transverse instabilities at specific longitudinal wave numbers. While the dipole instabilities can be suppressed by a combination of the Landau damping, machine impedance, and the active damper, the quadrupole and higher order modes can lead to either emittance growth, or a lifetime degradation, or both. The growth rates of these instabilities are strongly determined by the machine x-y coupling. Thus, tuning out of the coupling resonance and/or reduction of the machine coupling can be an efficient remedy for these instabilities.

  1. Physics with fast molecular-ion beams

    SciTech Connect (OSTI)

    Kanter, E.P.

    1980-01-01T23:59:59.000Z

    Fast (MeV) molecular-ion beams provide a unique source of energetic projectile nuclei which are correlated in space and time. The recognition of this property has prompted several recent investigations of various aspects of the interactions of these ions with matter. High-resolution measurements on the fragments resulting from these interactions have already yielded a wealth of new information on such diverse topics as plasma oscillations in solids and stereochemical structures of molecular ions as well as a variety of atomic collision phenomena. The general features of several such experiments will be discussed and recent results will be presented.

  2. PowerBeam Inc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation,Pillar Group BV Jump to: navigation,Power Rental Market Size HomeSourcesPowerBeam

  3. Yuan T. Lee's Crossed Molecular Beam Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires mayYuan T. Lee's Crossed Molecular Beam Experiment Home |

  4. Electron cyclotron beam measurement system in the Large Helical Device

    SciTech Connect (OSTI)

    Kamio, S., E-mail: kamio@nifs.ac.jp; Takahashi, H.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Ito, S.; Kobayashi, S.; Mizuno, Y.; Okada, K.; Osakabe, M.; Mutoh, T. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2014-11-15T23:59:59.000Z

    In order to evaluate the electron cyclotron (EC) heating power inside the Large Helical Device vacuum vessel and to investigate the physics of the interaction between the EC beam and the plasma, a direct measurement system for the EC beam transmitted through the plasma column was developed. The system consists of an EC beam target plate, which is made of isotropic graphite and faces against the EC beam through the plasma, and an IR camera for measuring the target plate temperature increase by the transmitted EC beam. This system is applicable to the high magnetic field (up to 2.75 T) and plasma density (up to 0.8 × 10{sup 19} m{sup ?3}). This system successfully evaluated the transmitted EC beam profile and the refraction.

  5. DEVICE CONTROL TOOL FOR CEBAF BEAM DIAGNOSTICS SOFTWARE

    SciTech Connect (OSTI)

    Pavel Chevtsov

    2008-02-11T23:59:59.000Z

    Continuously monitoring the beam quality in the CEBAF accelerator, a variety of beam diagnostics software created at Jefferson Lab makes a significant contribution to very high availability of the machine for nuclear physics experiments. The interface between this software and beam instrumentation hardware components is provided by a device control tool, which is optimized for beam diagnostics tasks. As a part of the device/driver development framework at Jefferson Lab, this tool is very easy to support and extend to integrate new beam instrumentation components. All device control functions are based on the configuration (ASCII text) files that completely define the used hardware interface standards (CAMAC, VME, RS-232, GPIB, etc.) and communication protocols. The paper presents the main elements of the device control tool for beam diagnostics software at Jefferson Lab.

  6. Ultraviolet laser beam monitor using radiation responsive crystals

    DOE Patents [OSTI]

    McCann, Michael P. (Oliver Springs, TN); Chen, Chung H. (Knoxville, TN)

    1988-01-01T23:59:59.000Z

    An apparatus and method for monitoring an ultraviolet laser beam includes disposing in the path of an ultraviolet laser beam a substantially transparent crystal that will produce a color pattern in response to ultraviolet radiation. The crystal is exposed to the ultraviolet laser beam and a color pattern is produced within the crystal corresponding to the laser beam intensity distribution therein. The crystal is then exposed to visible light, and the color pattern is observed by means of the visible light to determine the characteristics of the laser beam that passed through crystal. In this manner, a perpendicular cross sectional intensity profile and a longitudinal intensity profile of the ultraviolet laser beam may be determined. The observation of the color pattern may be made with forward or back scattered light and may be made with the naked eye or with optical systems such as microscopes and television cameras.

  7. Status of ITER neutral beam cell remote handling system

    E-Print Network [OSTI]

    Sykes, N; Choi, C-H; Crofts, O; Crowe, R; Damiani, C; Delavalle, S; Meredith, L; Mindham, T; Raimbach, J; Tesini, A; Van Uffelen, M

    2013-01-01T23:59:59.000Z

    The ITER neutral beam cell will contain up to three heating neutral beams and one diagnostic neutral beam, and four upper ports. Though manual maintenance work is envisaged within the cell, when containment is breached, or the radiological protection is removed the maintenance must be conducted remotely. This maintenance constitutes the removal and replacement of line replaceable units, and their transport to and from a cask docked to the cell. A design of the remote handling system has been prepared to concept level which this paper describes including the development of a beam line transporter, beam source remote handling equipment, upper port remote handling equipment and equipment for the maintenance of the neutral shield. This equipment has been developed complete the planned maintenance tasks for the components of the neutral beam cell and to have inherent flexibility to enable as yet unforeseen tasks and recovery operations to be performed.

  8. Piezoelectric energy harvester having planform-tapered interdigitated beams

    DOE Patents [OSTI]

    Kellogg, Rick A. (Tijeras, NM); Sumali, Hartono (Albuquerque, NM)

    2011-05-24T23:59:59.000Z

    Embodiments of energy harvesters have a plurality of piezoelectric planform-tapered, interdigitated cantilevered beams anchored to a common frame. The plurality of beams can be arranged as two or more sets of beams with each set sharing a common sense mass affixed to their free ends. Each set thus defined being capable of motion independent of any other set of beams. Each beam can comprise a unimorph or bimorph piezoelectric configuration bonded to a conductive or non-conductive supporting layer and provided with electrical contacts to the active piezoelectric elements for collecting strain induced charge (i.e. energy). The beams are planform tapered along the entirety or a portion of their length thereby increasing the effective stress level and power output of each piezoelectric element, and are interdigitated by sets to increase the power output per unit volume of a harvester thus produced.

  9. Beam Test of a Segmented Foil SEM Grid

    E-Print Network [OSTI]

    S. Kopp; D. Indurthy; Z. Pavlovich; M. Proga; R. Zwaska; S. Childress; R. Ford; C. Kendziora; T. Kobilarcik; C. Moore; G. Tassotto

    2005-07-29T23:59:59.000Z

    A prototype Secondary-electron Emission Monitor (SEM) was installed in the 8 GeV proton transport line for the MiniBooNE experiment at Fermilab. The SEM is a segmented grid made with 5 um Ti foils, intended for use in the 120 GeV NuMI beam at Fermilab. Similar to previous workers, we found that the full collection of the secondary electron signal requires a bias voltage to draw the ejected electrons cleanly off the foils, and this effect is more pronounced at larger beam intensity. The beam centroid and width resolutions of the SEM were measured at beam widths of 3, 7, and 8 mm, and compared to calculations. Extrapolating the data from this beam test, we expect a centroid and width resolutions of 20um and 25 um, respectively, in the NuMI beam which has 1 mm spot size.

  10. An ultra low noise AC beam transformer for deceleration and diagnostics of low intensity beams

    E-Print Network [OSTI]

    González, C

    1999-01-01T23:59:59.000Z

    The design of a broad band ultra-low noise ferrite loaded AC beam transformer is presented. It is designed for use in the CERN Antiproton Decelerator (AD), where beams of a few 107 charges must be decelerated from 3.5 GeV/c to 100 MeV/c. It is used in the RF beam-phase loop, and for intensity and bunch shape measurements during deceleration. When the beam is debunched for cooling on magnetic flat tops, the pick-up is used for measurements of intensity and momentum distribution by means of longitudinal Schottky scans. When used as Schottky pick-up, the signal to noise ratio should be better by about 40 dB than the existing stripline based longitudinal Schottky pick-up. The integrated design of pick-up and associated low-noise amplifier is presented. The achieved noise performance of a few from 1 to 3 MHz is obtained by attaching a low-noise, high-impedance silicon JFET (junction field effect transistor) amplifier to a high-Q resonant ferrite loaded cavity, and then eliminating the resonant response by low-nois...

  11. Studies of beam dynamics in relativistic klystron two-beam accelerators

    SciTech Connect (OSTI)

    Lidia, Steven M.

    1999-11-01T23:59:59.000Z

    Two-beam accelerators (TBAs) based upon free-electron lasers (FELs) or relativistic klystrons (RK-TBAs) have been proposed as efficient power sources for next generation high-energy linear colliders. Studies have demonstrated the possibility of building TBAs from X-band ({approximately}8-12 GHz) through Ka band ({approximately} 30-35 GHz) frequency regions. Provided that further prototyping shows stable beam propagation with minimal current loss and production of good quality, high-power rf fields, this technology is compatible with current schemes for electron-positron colliders in the multi-TeV center-of-mass scale. A new method of simulating the beam dynamics in accelerators of this type has been developed in this dissertation. There are three main components to this simulation. The first is a tracking algorithm to generate nonlinear transfer maps for pushing noninteracting particles through the external fields. The second component is a 3D Particle-In-Cell (PIC) algorithm that solves a set of Helmholtz equations for the self-fields, including the conducting boundary condition, and generates impulses that are interleaved with the nonlinear maps by means of a split-operation algorithm. The Helmholtz equations are solved by a multi-grid algorithm. The third component is an equivalent circuit equation solver that advances the modal rf cavity fields in time due to excitation by the modulated beam. The RTA project is described, and the simulation code is used to design the latter portions of the experiment. Detailed calculations of the beam dynamics and of the rf cavity output are presented and discussed. A beamline design is presented that will generate nearly 1.2 GW of power from 40 input, gain, and output rv cavities over a 10 m distance. The simulations show that beam current losses are acceptable, and that longitudinal and transverse focusing techniques are sufficient capable of maintaining a high degree of beam quality along the entire beamline. Additional experimental efforts are also described.

  12. Coherent beam combiner for a high power laser

    DOE Patents [OSTI]

    Dane, C. Brent (Livermore, CA); Hackel, Lloyd A. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    A phase conjugate laser mirror employing Brillouin-enhanced four wave mixing allows multiple independent laser apertures to be phase locked producing an array of diffraction-limited beams with no piston phase errors. The beam combiner has application in laser and optical systems requiring high average power, high pulse energy, and low beam divergence. A broad range of applications exist in laser systems for industrial processing, especially in the field of metal surface treatment and laser shot peening.

  13. Dual beam optical system for pulsed laser ablation film deposition

    DOE Patents [OSTI]

    Mashburn, Douglas N. (Knoxville, TN)

    1996-01-01T23:59:59.000Z

    A laser ablation apparatus having a laser source outputting a laser ablation beam includes an ablation chamber having a sidewall, a beam divider for dividing the laser ablation beam into two substantially equal halves, and a pair of mirrors for converging the two halves on a surface of the target from complementary angles relative to the target surface normal, thereby generating a plume of ablated material emanating from the target.

  14. Dual beam optical system for pulsed laser ablation film deposition

    DOE Patents [OSTI]

    Mashburn, D.N.

    1996-09-24T23:59:59.000Z

    A laser ablation apparatus having a laser source outputting a laser ablation beam includes an ablation chamber having a sidewall, a beam divider for dividing the laser ablation beam into two substantially equal halves, and a pair of mirrors for converging the two halves on a surface of the target from complementary angles relative to the target surface normal, thereby generating a plume of ablated material emanating from the target. 3 figs.

  15. Electron Gun For Multiple Beam Klystron Using Magnetic Focusing

    DOE Patents [OSTI]

    Ives, R. Lawrence (Saratoga, CA); Miram, George (Atherton, CA); Krasnykh, Anatoly (Santa Clara, CA)

    2004-07-27T23:59:59.000Z

    An RF device comprising a plurality of drift tubes, each drift tube having a plurality of gaps defining resonant cavities, is immersed in an axial magnetic field. RF energy is introduced at an input RF port at one of these resonant cavities and collected at an output RF port at a different RF cavity. A plurality of electron beams passes through these drift tubes, and each electron beam has an individual magnetic shaping applied which enables confined beam transport through the drift tubes.

  16. Electron beam melting state-of-the-art 1984

    SciTech Connect (OSTI)

    Bakish, R.

    1984-06-01T23:59:59.000Z

    In 1984 electron beam melting and refining appear poised for an important new growth phase. The driving force for this phase is improved production economics made possible by technological advances. There is also a new and exciting growth application for electron beam melting: its use for surface properties beneficiation. This article is based in part on the content of the Conference on Electron Beam Melting and Refining, The State-of-the-Art 1983, held in November 1983 in Reno, Nevada.

  17. Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation

    E-Print Network [OSTI]

    Booij, Wilfred Edwin

    Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation Wilfred Edwin Booij Gonville and Caius College Cambridge A dissertation submitted for the degree of Doctor of Philosophy at the University of Cambridge December 1997... Summary Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation The irradiation of high Tc superconducting thin films with a focused electron beam, such as that obtained in a scanning transmission electron microscope (STEM), can...

  18. Nonclassicality of vortex Airy beams in the Wigner representation

    SciTech Connect (OSTI)

    Chen Ruipin [School of Sciences, Zhejiang A and F University, Lin'an, Zhejiang Province 311300 (China); Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Ooi, C. H. Raymond [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2011-10-15T23:59:59.000Z

    The Wigner distribution function (WDF) of a vortex Airy beam is calculated analytically. The WDF provides intuitive pictures of the intriguing features of vorticity in phase space. The nonclassical property of the vortex Airy beam and the Airy beam is analyzed through the negative parts of the WDF. The study shows that destructive interference of certain classical waves can mimic nonclassical lights such as those due to quantum effects.

  19. Computational Modeling of Conventionally Reinforced Concrete Coupling Beams 

    E-Print Network [OSTI]

    Shastri, Ajay Seshadri

    2012-02-14T23:59:59.000Z

    .20. Stress Distribution Showing the Formation of the Compression Strut.........99 Fig. 6.1. Section and Reinforcement Details for Specimen NR4 (Bristowe 2000)...101 Fig. 6.2. Test Setup for the Coupling Beams (Bristowe 2000... research on reinforced concrete coupling beams. Various types of failures observed in coupling beam tests are discussed in this section including the following: 14 ? Shear compression (SC): This failure is usually seen in conventionally...

  20. Neutral Beam Power System for TPX

    SciTech Connect (OSTI)

    Ramakrishnan, S.; Bowen, O.N.; O`Conner, T.; Edwards, J.; Fromm, N.; Hatcher, R.; Newman, R.; Rossi, G.; Stevenson, T.; von Halle, A.

    1993-11-01T23:59:59.000Z

    The Tokamak Physics Experiment (TPX) will utilize to the maximum extent the existing Tokamak Fusion Test Reactor (TFTR) equipment and facilities. This is particularly true for the TFTR Neutral Beam (NB) system. Most of the NB hardware, plant facilities, auxiliary sub-systems, power systems, service infrastructure, and control systems can be used as is. The major changes in the NB hardware are driven by the new operating duty cycle. The TFTR Neutral Beam was designed for operation of the Sources for 2 seconds every 150 seconds. The TPX requires operation for 1000 seconds every 4500 seconds. During the Conceptual Design Phase of TPX every component of the TFTR NB Electrical Power System was analyzed to verify whether the equipment can meet the new operational requirements with our without modifications. The Power System converts 13.8 kV prime power to controlled pulsed power required at the NB sources. The major equipment involved are circuit breakers, auto and rectifier transformers surge suppression components, power tetrodes, HV Decks, and HVDC power transmission to sources. Thermal models were developed for the power transformers to simulate the new operational requirements. Heat runs were conducted for the power tetrodes to verify capability. Other components were analyzed to verify their thermal limitations. This paper describes the details of the evaluation and redesign of the electrical power system components to meet the TPX operational requirements.

  1. Diagnostic system for profiling micro-beams

    DOE Patents [OSTI]

    Elmer, John W. (Danville, CA); Palmer, Todd A. (Livermore, CA); Teruya, Alan T. (Livermore, CA); Walton, Chris C. (Berkeley, CA)

    2007-10-30T23:59:59.000Z

    An apparatus for characterization of a micro beam comprising a micro modified Faraday cup assembly including a first layer of material, a second layer of material operatively connected to the first layer of material, a third layer of material operatively connected to the second layer of material, and a fourth layer of material operatively connected to the third layer of material. The first layer of material comprises an electrical conducting material and has at least one first layer radial slit extending through the first layer. An electrical ground is connected to the first layer. The second layer of material comprises an insulating material and has at least one second layer radial slit corresponding to the first layer radial slit in the first layer of material. The second layer radial slit extends through the second layer. The third layer of material comprises a conducting material and has at least one third layer radial slit corresponding to the second layer radial slit in the second layer of material. The third layer radial slit extends through the third layer. The fourth layer of material comprises an electrical conducting material but does not have slits. An electrical measuring device is connected to the fourth layer. The micro modified Faraday cup assembly is positioned to be swept by the micro beam.

  2. Energy Production Demonstrator for Megawatt Proton Beams

    E-Print Network [OSTI]

    Pronskikh, Vitaly S; Novitski, Igor; Tyutyunnikov, Sergey I

    2014-01-01T23:59:59.000Z

    A preliminary study of the Energy Production Demonstrator (EPD) concept - a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming - is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated with the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5 to 120 GeV. This study shows that the proton energy range of 2 to 4 GeV is optimal for both a natU EPD and the tungsten-based testing station that would be the most suitable for proton accelerator facilities. Conservative estimates, not including breeding and fission of plutonium, based on the simulations suggest that the proton beam current of 1 mA will be sufficient to produce 1 GW of thermal output power with the natU EPD while supplying < 8% of that power to operate the accelerator. The thermal analysis shows that the concept considered has a problem due to a possible core meltdown; however...

  3. Acceleration of trapped particles and beams

    E-Print Network [OSTI]

    Er'el Granot; Boris Malomed

    2011-07-30T23:59:59.000Z

    The dynamics of a quantum particle bound by an accelerating delta-functional potential is investigated. Three cases are considered, using the reference frame moving along with the {\\delta}-function, in which the acceleration is converted into the additional linear potential. (i) A stationary regime, which corresponds to a resonance state, with a minimum degree of delocalization, supported by the accelerating potential trap. (ii) A pulling scenario: an initially bound particle follows the accelerating delta-functional trap, within a finite time. (iii) The pushing scenario: the particle, which was initially localized to the right of the repulsive delta-function, is shoved to the right by the accelerating potential. For the two latter scenarios, the life time of the trapped particle, and the largest velocity to which it can be accelerated while staying trapped, are found. Analytical approximations are developed for the cases of small and large accelerations in the pulling regime, and also for a small acceleration in the stationary situation, and in the regime of pushing. The same regimes may be realized by Airy-like planar optical beams guided by a narrow bending potential channel or crest. Physical estimates are given for an atom steered by a stylus of a scanning tunneling microscope (STM), and for the optical beam guided by a bending stripe.

  4. Beam Dynamics and Instabilities in ELIC Design

    SciTech Connect (OSTI)

    S. Ahmed,B. Yunn,G. Krafft

    2011-09-01T23:59:59.000Z

    In this paper, we report the first study of beam related instabilities in lepton ring of the proposed electron-ion collider beyond the 12 GeV upgrade of CEBAF at Jefferson lab. The design parameters are consistent with PEP-II. Present studies reveal that coupled bunch and two stream instabilities are important issues and we need feedback system. The Medium Energy Electron Ion Collider (MEIC) at Jefferson Lab has been envisioned as future high energy particle accelerator beyond the 12 GeV upgrade of CEBAF. The MEIC will consist of the existing polarized electron source complex with 12 GeV upgrade and a new ion complex with polarized and unpolarized light to medium ions. The conceptual layout is shown in Fig. 1 and the basic parameters in comparison with the similar machines are discussed in Table 1. The maximum permissible collision frequency at 1.5 GHz is dictated by the existing electron machine, allowing the relatively small charge per bunch and large crossing angle resulting in the increased beam stability and high luminosity. In this paper, we present the preliminary study of collective effects for e-ring.

  5. First beam at DARHT-II

    SciTech Connect (OSTI)

    Ekdahl, C. A. (Carl A.); Abeyta, E. O. (Epifanio Orlando); Caudill, L. D. (Larry D.); Dalmas, D. A. (Dale Allen); Eversole, S. A. (Steven A.); Harrison, J. F. (James F.); Holzscheiter, M. H. (Michael H.); Johnson, J. B. (Jeffrey B.); Jacquez, E. B. (Edward B.); McCuistian, B. T. (Brian T.); Nielson, K. E.; Oro, D. M. (David M.); Schauer, M. M. (Michael M.); Studebaker, J. K. (Jan K.); Sullivan, G. K. (Gregg K.); Temple, R. D. (Rodney Dean)

    2003-01-01T23:59:59.000Z

    The second axis of the Dual Axis Radiographic Hydro-Test (DARHT) facility will provide up to four short (<100 ns) radiation pulses for flash radiography of high-explosive driven implosion experiments. To accomplish this the DARHT-I1 linear induction accelerator (LIA) will produce a 2-kA electron beam with 18-MeV kinetic energy, constant to within 2 0.5% for 2-ps. A fast kicker will cleave four short pulses out of the 2-ps flattop, with the bulk of the beam diverted into a dump. The short pulses will then be transported to the final-focus magnet, and focused onto a tantalum target for conversion to bremsstrahlung pulses for radiography. DARHT-II is a collaborative effort between Los Alamos, Livermore, and Berkeley National Laboratories. The first tests of the second axis accelerator, described herein, were performed to demonstrate the technology and to meet the performance requirements for closing out the DARHT-II construction project.

  6. Towards demonstration of electron cooling with bunched electron beam

    SciTech Connect (OSTI)

    Fedotov, A.

    2012-01-11T23:59:59.000Z

    All electron cooling systems which were in operation so far employed electron beam generated with an electrostatic electron gun in DC operating mode, immersed in a longitudinal magnetic field. At low energies magnetic field is also being used to transport electron beam through the cooling section from the gun to the collector. At higher energies (few MeV), it was shown that one can have simpler electron beam transport without continuous magnetic field. Because of a rather weak magnetic field on the cathode and in the cooling section the latter approach was referred to as 'non-magnetized cooling', since there was no suppression of the transverse angular spread of the electron beam with the magnetic field in the cooling section. Such a cooler successfully operated at FNAL (2005-11) at electron beam energy of 4.3 MeV. Providing cooling at even higher energies would be easier with RF acceleration of electron beam, and thus using bunched electron beam for cooling. Significant efforts were devoted to explore various aspects of such bunched electron beam cooling as part of R and D of high-energy electron cooling for RHIC. However, experimental studies of such cooling are still lacking. Establishing this technique experimentally would be extremely useful for future high-energy applications. Presently there is an ongoing effort to build Proof-of-Principle (PoP) experiment of Coherent Electron Cooling (CEC) at RHIC, which promises to be superior to conventional electron cooling for high energies. Since the CEC experiment is based on bunched electron beam and it has sections where electron beam co-propagates with the ion beam at the same velocity, it also provides a unique opportunity to explore experimentally conventional electron cooling but for the first time with a bunched electron beam. As a result, it allows us to explore techniques needed for the high-energy electron cooling such as 'painting' with a short electron beam and control of ion beam distribution under cooling which is essential if cooling is provided in a collider. The software needed for comparison with the experiments is already developed as part of the previous high-energy electron cooling studies for RHIC. Since electron beam will be non-magnetized and there will be no magnetic field in the cooling section it will be also a first demonstration of fully non-magnetized cooling. The purpose of these studies was to explore whether we would be able to observe conventional electron cooling with parameters expected in the CEC PoP experiment. Below we summarize requirements on electron beam and cooling section needed for such demonstration.

  7. {sup 18}Ne production for the Beta beams project

    SciTech Connect (OSTI)

    Hodák, Rastislav [Institute of Experimental and Applied Physics, CTU in Prague, Horská 3/22a, CZ-12800 Prague (Czech Republic); Mendonça, Tania M. [IFIMUP and IN - Institute of Nanosciences and Nanotechnologies, Rua do Campo Alegre 687, 4169-007 Porto, Portugal and CERN, CH-1211 Geneva 23 (Swaziland); Stora, Thierry [CERN, CH-1211 Geneva 23 (Switzerland)

    2013-12-30T23:59:59.000Z

    Intense relativistic (anti)neutrino beams are an unique tool required to study fundamental properties of neutrinos such as neutrino oscillation parameters, as well as their Majorana or Dirac nature, the lepton number conservation hypothesis and the absolute neutrino mass scale. Such beams originate from acceleration of ?-decaying radioactive ions (“Beta beams”). A molten fluoride salt target has been developed for the production of the required rates of low-Q baseline isotope {sup 18}Ne for the Beta beams project. The prototyped unit has been tested on-line at ISOLDE-CERN. In this contribution an overview of the prototyping and on-line tests is presented.

  8. Study on electron beam in a low energy plasma focus

    SciTech Connect (OSTI)

    Khan, Muhammad Zubair, E-mail: mzubairkhan-um76@yahoo.com [Plasma Technology Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia and Department of Physics, Federal Urdu University of Arts, Science and Technology, 45320 Islamabad (Pakistan); Ling, Yap Seong; San, Wong Chiow [Plasma Technology Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-03-05T23:59:59.000Z

    Electron beam emission was investigated in a low energy plasma focus device (2.2 kJ) using copper hollow anode. Faraday cup was used to estimate the energy of the electron beam. XR100CR X-ray spectrometer was used to explore the impact of the electron beam on the target observed from top-on and side-on position. Experiments were carried out at optimized pressure of argon gas. The impact of electron beam is exceptionally notable with two different approaches using lead target inside hollow anode in our plasma focus device.

  9. Physics Potential of the gamma=100,100 Beta Beam

    E-Print Network [OSTI]

    M. Mezzetto

    2005-11-02T23:59:59.000Z

    The physics potential of a Beta Beam fired from CERN to a 440 kton water Cerenkov detector at a distance of 130 Km is computed.

  10. Betatron radiation from electron beams in plasma focusing channels

    E-Print Network [OSTI]

    Esarey, E.; Catravas, P.; Leemans, W.P.

    2000-01-01T23:59:59.000Z

    Betatron Radiation from Electron Beams in Plasma FocusingAbstract. Spontaneous radiation emitted from an electronfrequency of spontaneous radiation is a strong function of

  11. Self-pinched transport of a high ?/? electron beam

    SciTech Connect (OSTI)

    Myers, M. C.; Wolford, M. F.; Sethian, J. D. [U.S. Naval Research Laboratory, Plasma Physics Division, 4555 Overlook Ave., SW, Washington DC 20375 (United States)] [U.S. Naval Research Laboratory, Plasma Physics Division, 4555 Overlook Ave., SW, Washington DC 20375 (United States); Rose, D. V. [Voss Scientific, 418 Washington St. SE, Albuquerque, New Mexico 87108 (United States)] [Voss Scientific, 418 Washington St. SE, Albuquerque, New Mexico 87108 (United States); Hegeler, F. [Commonwealth Technology Inc., 5875 Barclay Drive, Alexandria, Virginia 22315 (United States)] [Commonwealth Technology Inc., 5875 Barclay Drive, Alexandria, Virginia 22315 (United States)

    2013-10-15T23:59:59.000Z

    The self-pinched transport of a 0.5 MeV, 18 kA cylindrical electron beam has been studied experimentally and computationally. The relatively low voltage and high current required for materials surface modification applications leads to complicated beam dynamics as the Alfven limit is approached. Transport and focusing of the high ?/? beam was done in a sub-Torr, neutral gas-filled, conducting tube in the ion-focused regime. In this regime, beam space charge forces are progressively neutralized to allow focusing of the beam by its self-magnetic field. The beam exhibits stable envelope oscillations as it is efficiently and reproducibly propagated for distances greater than a betatron wavelength. Experimental results follow the trends seen in 2-D particle-in-cell simulations. Results show that the input electron beam can be periodically focused to a peaked profile with the beam half-current radius decreased by a factor of 2.84. This results in an increase of a factor of 8 in beam current density. This focusing is sufficient to produce desired effects in the surface layers of metallic materials.

  12. A High Count Rate Beam Monitor for Thermal Neutrons

    SciTech Connect (OSTI)

    Barnett, Amanda [University of Tennessee, Knoxville (UTK); Crow, Lowell [ORNL; Diawara, Yacouba [ORNL; Funk, Loren L [ORNL; Hayward, J P [University of Tennessee, Knoxville (UTK); Menhard, Kocsis [European Synchrotron Radiation Facility (ESRF); Sedov, Vladislav N [ORNL

    2012-01-01T23:59:59.000Z

    Beam monitors are an important diagnostic tool in neutron science facilities. Present beam monitors use either ionization chambers in integration mode, which are slow and have no timing information, or pulse counters which can easily be saturated by high beam intensities. Neutron beam monitors indicate the number of neutrons incident on a scattering sample and allow neutron experimental data to be analyzed even when the source strength varies with time. At high flux neutron scattering facilities, neutron beam monitors with very low efficiency (10-5) are presently selected to keep the counting rate within a feasible range, even when a higher efficiency would improve the counting statistics and yield a better measurement of the incident beam. In this work, we report on a high count rate neutron beam monitor which also offers position sensitivity to provide a beam profile. This beam monitor offers good timing (less than 1 s) in addition to position resolution and will therefore improve the counting statistics at neutron energies up to 10 eV and allow moderator studies. The detector s main characteristics will be presented including its background rate, its count rate capability which is an order of magnitude higher than present counting monitors, and its efficiency for thermal neutrons.

  13. Electron-beam induced recrystallization in amorphous apatite...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    recrystallization observed in the present study. Citation: Bae IT, Y Zhang, WJ Weber, M Higuchi, and L Giannuzzi.2007."Electron-beam induced recrystallization in amorphous...

  14. Structural Modification of Nanocrystalline Ceria by Ion Beams...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    nanoscale. Citation: Zhang Y, PD Edmondson, T Varga, SJ Moll, F Namavar, C Lan, and WJ Weber.2011."Structural Modification of Nanocrystalline Ceria by Ion Beams."Physical...

  15. Temperature dependence of electron-beam induced effects in amorphous...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and the electron hammering effect, respectively. Citation: Bae IT, Y Zhang, WJ Weber, M Ishimaru, Y Hirotsu, and M Higuchi.2008."Temperature dependence of electron-beam...

  16. absolute beam current: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (FBCCM) is an example. It is based on analogue signals from fast beam current transformers (FBCT) used nominally to measure the LHC bunch intensities. The FBCCM calculates...

  17. amp beam currents: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (FBCCM) is an example. It is based on analogue signals from fast beam current transformers (FBCT) used nominally to measure the LHC bunch intensities. The FBCCM calculates...

  18. accelerated electron beams: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of the various flavors of Particle Accelerator Conferences 23 contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series 24 contains one...

  19. accelerator electron beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of the various flavors of Particle Accelerator Conferences 23 contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series 24 contains one...

  20. Beam transport design for a recirculating-linac FEL driver

    SciTech Connect (OSTI)

    Neuffer, D.; Douglas, D. [CEBAF, Newport News, VA (United States); Li, Z.; Cornacchia, M. [Stanford Univ., CA (United States); Garren, A. [Lawrence Berkeley Lab., CA (United States)

    1996-07-01T23:59:59.000Z

    The beam transport system for the CEBAF Industrial FEL includes a two-pass transport of the beam with acceleration from injector to wiggler, followed by energy recovery transport from wiggler to dump. From that context, the authors discuss the general problem of multi-pass energy-recovery beam transport for FELs. Tunable, nearly-isochronous, large-momentum-acceptance transport systems are required. The entire transport must preserve beam quality, particularly in the acceleration transport to the wiggler, and have low losses throughout the entire system. Various possible designs are presented, and results of dynamic analyses are discussed.

  1. Low energy beam line at the AGOR facility

    SciTech Connect (OSTI)

    Toprek, Dragan; Formanoy, Iwo; Brandenburg, Sytze [VINCA Institute of Nuclear Sciences, Laboratory for Nuclear and Plasma Physics, B.O. Box 522, 11001 Belgrade (Serbia and Montenegro); Kernfysisch Versneller Instituut (KVI), Zernikelaan 25, 9747 AA, Groningen (Netherlands)

    2005-01-01T23:59:59.000Z

    The origin of the low transmission through the low energy beam line between the electron cyclotron resonance source and the AGOR cyclotron has been investigated. Measurements of beam size and emittance, determined with the ''varying quadrupole method,'' are compared with calculations including fringe fields up to third order with the code COSY INFINITY. Calculations and measurements qualitatively agree; the calculations exhibit the large beam losses observed. On the basis of the calculations new settings have been determined, resulting in a significant increase of the transmission. To achieve full transmission a complete redesign of the beam line, in particular of the bending magnets, is needed.

  2. Endoscopic Electron-Beam Cancer Therapy | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Endoscopic Electron-Beam Cancer Therapy Technology available for licensing: A successful and cost-effective means of treating cancer in previously inoperable or radiation-sensitive...

  3. Longitudinal bunch profile and electron beam energy spread

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    APS Storage Ring Parameters Previous: Storage Ring Operation Modes Longitudinal bunch profile and electron beam energy spread Longitudinal bunch profile depends mainly on the...

  4. Low Impedance Bellows for High-current Beam Operations

    SciTech Connect (OSTI)

    Wu, G; Nassiri, A; Waldschmidt, G J; Yang, Y; Feingold, J J; Mammosser, J D; Rimmer, R A; Wang, H; Jang, J

    2012-07-01T23:59:59.000Z

    In particle accelerators, bellows are commonly used to connect beamline components. Such bellows are traditionally shielded to lower the beam impedance. Excessive beam impedance can cause overheating in the bellows, especially in high beam current operation. For an SRF-based accelerator, the bellows must also be particulate free. Many designs of shielded bellows incorporate rf slides or fingers that prevent convolutions from being exposed to wakefields. Unfortunately these mechanical structures tend to generate particulates that, if left in the SRF accelerator, can migrate into superconducting cavities, the accelerator's critical components. In this paper, we describe a prototype unshielded bellows that has low beam impedance and no risk of particulate generation.

  5. aluminium beams strengthened: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: FOR STRENGTHENING OF STEEL-CONCRETE COMPOSITE BEAMS WITH HIGH MODULUS CFRP MATERIALS David Schnerch Wiss, Janney for High Modulus Carbon Fiber Material Property Fiber...

  6. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOE Patents [OSTI]

    Birx, D.L.; Reginato, L.L.

    1984-03-22T23:59:59.000Z

    An electron beam accelerator is described comprising an electron beam generator-injector to produce a focused beam of greater than or equal to .1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electron by about .1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .1-1 MeV maximum energy over a time duration of less than or equal to 1 ..mu..sec.

  7. Beam instrumentation for future high intense hadron accelerators at Fermilab

    SciTech Connect (OSTI)

    Wendt, M.; Hu, M.; Tassotto, G.; Thurman-Keup, R.; Scarpine, V.; Shin, S.; Zagel, J.; /Fermilab

    2008-08-01T23:59:59.000Z

    High intensity hadron beams of up to 2 MW beam power are a key element of new proposed experimental facilities at Fermilab. Project X, which includes a SCRF 8 GeV H{sup -} linac, will be the centerpiece of future HEP activities in the neutrino sector. After a short overview of this, and other proposed projects, we present the current status of the beam instrumentation activities at Fermilab with a few examples. With upgrades and improvements they can meet the requirements of the new beam facilities, however design and development of new instruments is needed, as shown by the prototype and conceptual examples in the last section.

  8. Beam Position Monitor Electronics Upgrade for Fermilab Switchyard

    E-Print Network [OSTI]

    Stabile, P; Fitzgerald, J A; Liu, N; Morris, D K; Prieto, P S; Seraphin, J P

    2015-01-01T23:59:59.000Z

    The beam position monitor (BPM) system for Fermilab Switchyard (SY) provides the position, intensity and integrated intensity of the 53.10348 MHz RF bunched resonant extracted beam from the Main Injector over 4 seconds of spill. The total beam intensity varies from 1x10^11 to 1x10^13 protons. The spill is measured by stripline beam postion monitors and resonant circuit. The BPMs have an external resonant circuit tuned to 53.10348 MHz. The corresponding voltage signal out of the BPM has been estimated to be between -110 dBm and -80 dBm.

  9. Development of hollow electron beams for proton and ion collimation

    SciTech Connect (OSTI)

    Stancari, G.; Drozhdin, A.I.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; /Fermilab; Assmann, R.; /CERN; Kabantsev, A.; /UC, San Diego

    2010-06-01T23:59:59.000Z

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  10. aggregate concrete beams: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    FIBRE REINFORCED HIGH PERFORMANCE CONCRETE Engineering Websites Summary: -456 STEEL FIBRE REINFORCED HIGH PERFORMANCE CONCRETE BEAM-COLUMN JOINTS SUBJECTED TO CYCLIC LOADING...

  11. area electron beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    semiconductor. In particular, focused ion beam (FIB) milling can result in physical damage, implantation and doping of the specimen surface with Ga, as well as thickness...

  12. Extraction of a steady state electron beam from HCD (hollow cathode discharge) plasmas for EBIS (electron beam ion source) applications

    SciTech Connect (OSTI)

    Hershcovitch, A.; Kovarik, V.; Prelec, K.

    1988-01-01T23:59:59.000Z

    Experiments to extract high brightness electron beams from hollow cathode discharge plasmas are now in progress. A unique feature of these plasmas, which in principle can facilitate the extraction of large current low emittance electron beams, is the existence of a relatively high energy electron population with a very narrow energy spread. This electron population was identified in a self-extraction experiment, which yielded a 35 eV, 600 mA electron beam with parallel energy spread of less than 0.5 eV. Preliminary, crude application of 2.5 kV extraction voltage yielded a steady state electron beam current of 1.2 A. The end result of this endeavor would be an Electron Beam Ion Source (EBIS) with an electron beam current of 6 A. 4 refs., 2 figs.

  13. The MICE Muon Beam on ISIS and the beam-line instrumentation of the Muon Ionization Cooling Experiment

    SciTech Connect (OSTI)

    Bogomilov, M. [University of Sofia (Bulgaria); et al.

    2012-05-01T23:59:59.000Z

    The international Muon Ionization Cooling Experiment (MICE), which is under construction at the Rutherford Appleton Laboratory (RAL), will demonstrate the principle of ionization cooling as a technique for the reduction of the phase-space volume occupied by a muon beam. Ionization cooling channels are required for the Neutrino Factory and the Muon Collider. MICE will evaluate in detail the performance of a single lattice cell of the Feasibility Study 2 cooling channel. The MICE Muon Beam has been constructed at the ISIS synchrotron at RAL, and in MICE Step I, it has been characterized using the MICE beam-instrumentation system. In this paper, the MICE Muon Beam and beam-line instrumentation are described. The muon rate is presented as a function of the beam loss generated by the MICE target dipping into the ISIS proton beam. For a 1 V signal from the ISIS beam-loss monitors downstream of our target we obtain a 30 KHz instantaneous muon rate, with a neglible pion contamination in the beam.

  14. The MICE Muon Beam on ISIS and the beam-line instrumentation of the Muon Ionization Cooling Experiment

    E-Print Network [OSTI]

    MICE Collaboration

    2012-03-23T23:59:59.000Z

    The international Muon Ionization Cooling Experiment (MICE), which is under construction at the Rutherford Appleton Laboratory (RAL), will demonstrate the principle of ionization cooling as a technique for the reduction of the phase-space volume occupied by a muon beam. Ionization cooling channels are required for the Neutrino Factory and the Muon Collider. MICE will evaluate in detail the performance of a single lattice cell of the Feasibility Study 2 cooling channel. The MICE Muon Beam has been constructed at the ISIS synchrotron at RAL, and in MICE Step I, it has been characterized using the MICE beam-instrumentation system. In this paper, the MICE Muon Beam and beam-line instrumentation are described. The muon rate is presented as a function of the beam loss generated by the MICE target dipping into the ISIS proton beam. For a 1 V signal from the ISIS beam-loss monitors downstream of our target we obtain a 30 KHz instantaneous muon rate, with a neglible pion contamination in the beam.

  15. A Two Bunch Beam Position Monitor

    SciTech Connect (OSTI)

    Medvedko, E.; Aiello, R.; Smith, S.; /SLAC

    2011-09-12T23:59:59.000Z

    A new beam position monitor digitizer module has been designed, tested and tuned at SLAC. This module, the electron-positron beam position monitor (epBPM), measures position of single electron and positron bunches for the SLC, LINAC, PEPII injections lines and final focus. The epBPM has been designed to improve resolution of beam position measurements with respect to existing module and to speed feedback correction. The required dynamic range is from 5 x 10{sup 8} to 10{sup 11} particles per bunch (46dB). The epBPM input signal range is from {+-}2.5 mV to {+-}500 mV. The pulse-to-pulse resolution is less than 2 {mu}m for 5 x 10{sup 10} particles per bunch for the 12 cm long striplines, covering 30{sup o} at 9 mm radius. The epBPM module has been made in CAMAC standard, single width slot, with SLAC type timing connector. 45 modules have been fabricated. The epBPM module has four input channels X{sup +}, X{sup -}, Y{sup +}, Y{sup -} (Fig. 1), named to correspond with coordinates of four striplines - two in horizontal and two in vertical planes, processing signals to the epBPM inputs. The epBPM inputs are split for eight signal processing channels to catch two bunches, first - the positron, then the electron bunch in one cycle of measurements. The epBPM has internal and external trigger modes of operations. The internal mode has two options - with or without external timing, catching only first bunch in the untimed mode. The epBPM has an on board calibration circuit for measuring gain of the signal processing channels and for timing scan of programmable digital delays to synchronize the trigger and the epBPM input signal's peak. There is a mode for pedestal measurements. The epBPM has 3.6 {mu}s conversion time.

  16. Method of automatic measurement and focus of an electron beam and apparatus therefore

    DOE Patents [OSTI]

    Giedt, W.H.; Campiotti, R.

    1996-01-09T23:59:59.000Z

    An electron beam focusing system, including a plural slit-type Faraday beam trap, for measuring the diameter of an electron beam and automatically focusing the beam for welding is disclosed. Beam size is determined from profiles of the current measured as the beam is swept over at least two narrow slits of the beam trap. An automated procedure changes the focus coil current until the focal point location is just below a workpiece surface. A parabolic equation is fitted to the calculated beam sizes from which optimal focus coil current and optimal beam diameter are determined. 12 figs.

  17. Wind acceleration in AGB stars: Solid ground and loose ends

    E-Print Network [OSTI]

    Höfner, Susanne

    2015-01-01T23:59:59.000Z

    The winds of cool luminous AGB stars are commonly assumed to be driven by radiative acceleration of dust grains which form in the extended atmospheres produced by pulsation-induced shock waves. The dust particles gain momentum by absorption or scattering of stellar photons, and they drag along the surrounding gas particles through collisions, triggering an outflow. This scenario, here referred to as Pulsation-Enhanced Dust-DRiven Outflow (PEDDRO), has passed a range of critical observational tests as models have developed from empirical and qualitative to increasingly self-consistent and quantitative. A reliable theory of mass loss is an essential piece in the bigger picture of stellar and galactic chemical evolution, and central for determining the contribution of AGB stars to the dust budget of galaxies. In this review, I discuss the current understanding of wind acceleration and indicate areas where further efforts by theorists and observers are needed.

  18. Y0: loose stool Y1: indigested grain in stool

    E-Print Network [OSTI]

    Zhang, Nevin L.

    : lassitude Y17: prolonged illness Y18: cough with dyspnea X8(4) Y19: loss of hair and teeth X9(4) Y20: poor

  19. Loose Nukes: Nuclear Material Security in G.P.Gilfoyle

    E-Print Network [OSTI]

    Gilfoyle, Jerry

    · The picture below illustrates the effect of a 20 kiloton blast (about the size of the Nagasaki bomb) dropped on the Edwards Accelerator Lab- oratory. · The energy is emitted as heat, radiation, and blast. The dot-standing policy of nuclear nonproliferation. · A nuclear blast would have horrific consequences; loss of life

  20. LOOSE TIPPING BPG NOTE 4 Best Practice Guidance

    E-Print Network [OSTI]

    , 2000). The ROOTS software package for greening brownfield land can help in drawing up specifications

  1. Helical Muon Beam Cooling Channel Engineering Design

    SciTech Connect (OSTI)

    Kashikhin, V.S.; Lopes, M.L.; Romanov, G.V.; Tartaglia, M.A.; Yonehara, K.; Yu, M.; Zlobin, A.V.; /Fermilab; Flanagan, G.; Johnson, R.P.; Kazakevich, G.M.; Marhauser, F.; /MUONS Inc., Batavia

    2012-05-01T23:59:59.000Z

    The Helical Cooling Channel (HCC), a novel technique for six-dimensional (6D) ionization cooling of muon beams, has shown considerable promise based on analytic and simulation studies. However, the implementation of this revolutionary method of muon cooling requires new techniques for the integration of hydrogen-pressurized, high-power RF cavities into the low-temperature superconducting magnets of the HCC. We present the progress toward a conceptual design for the integration of 805 MHz RF cavities into a 10 T Nb{sub 3}Sn based HCC test section. We include discussions on the pressure and thermal barriers needed within the cryostat to maintain operation of the magnet at 4.2 K while operating the RF and energy absorber at a higher temperature. Additionally, we include progress on the Nb{sub 3}Sn helical solenoid design.

  2. Multi-transmission-line-beam interactive system

    SciTech Connect (OSTI)

    Figotin, Alexander; Reyes, Guillermo [Department of Mathematics, University of California at Irvine, Irvine, California 92697-3875 (United States)] [Department of Mathematics, University of California at Irvine, Irvine, California 92697-3875 (United States)

    2013-11-15T23:59:59.000Z

    We construct here a Lagrangian field formulation for a system consisting of an electron beam interacting with a slow-wave structure modeled by a possibly non-uniform multiple transmission line (MTL). In the case of a single line we recover the linear model of a traveling wave tube due to J. R. Pierce. Since a properly chosen MTL can approximate a real waveguide structure with any desired accuracy, the proposed model can be used in particular for design optimization. Furthermore, the Lagrangian formulation provides: (i) a clear identification of the mathematical source of amplification, (ii) exact expressions for the conserved energy and its flux distributions obtained from the Noether theorem. In the case of uniform MTLs we carry out an exhaustive analysis of eigenmodes and find sharp conditions on the parameters of the system to provide for amplifying regimes.

  3. Superconductive silicon nanowires using gallium beam lithography.

    SciTech Connect (OSTI)

    Henry, Michael David; Jarecki, Robert Leo,

    2014-01-01T23:59:59.000Z

    This work was an early career LDRD investigating the idea of using a focused ion beam (FIB) to implant Ga into silicon to create embedded nanowires and/or fully suspended nanowires. The embedded Ga nanowires demonstrated electrical resistivity of 5 m-cm, conductivity down to 4 K, and acts as an Ohmic silicon contact. The suspended nanowires achieved dimensions down to 20 nm x 30 nm x 10 m with large sensitivity to pressure. These structures then performed well as Pirani gauges. Sputtered niobium was also developed in this research for use as a superconductive coating on the nanowire. Oxidation characteristics of Nb were detailed and a technique to place the Nb under tensile stress resulted in the Nb resisting bulk atmospheric oxidation for up to years.

  4. Corrugated Pipe as a Beam Dechirper

    SciTech Connect (OSTI)

    Bane, K.L.F.; Stupakov, G.; /SLAC

    2012-04-20T23:59:59.000Z

    We have studied the use of a metallic pipe with small corrugations for the purpose of passively dechirping, through its wakefield, a short, intense electron bunch. The corrugated pipe is attractive for this purpose because its wake: (i) has near maximal possible amplitude for a given aperture and (ii) has a relatively large oscillation wave length, even when the aperture is small. We showed how the corrugated structure can satisfy dechirping requirements encountered in the NGLS project at LBNL. We found that a linear chirp of -40 MeV/mm can be induced by an NGLS-like beam, by having it pass through a corrugated, metallic pipe of radius 3 mm, length 8.2 m, and corrugation parameters full depth 450 {mu}m and period 1000 {mu}m. This structure is about 15 times as effective in the role of dechirper as an S-band accelerator structure used passively.

  5. Electron Cloud with Inverted Beam Screens

    E-Print Network [OSTI]

    Maury Cuna, H

    2011-01-01T23:59:59.000Z

    We report the results of computer simulations studying the effect of wrongly oriented LHC beam screens on the local electron-cloud heat load and density. At 3.5 or 7-TeV energy and for maximum secondary emission-yield values below 1.5, with the inverted sawtooth orientation about ten times higher heat load is expected than for the standard orientation, and the wrongly oriented sawtooth chambers could lead to a local heat-load bottleneck during the process of surface conditioning at 25-ns bunch spacing. The available cooling margin can be significantly increased by correcting the sawtooth orientations at least for two dipole magnets in LHC arc cells 26 and 32 R3, in order that there be no half-cell cooling loop containing more than one inverted screen.

  6. Are BL Lacertae Objects Beamed QSO Remnants?

    E-Print Network [OSTI]

    E. F. Borra

    1994-08-05T23:59:59.000Z

    This paper considers the hypothesis that BL Lacertae objects (BLLs) are the beamed remnants of Quasi Stellar Objects. The hypothesis explains why BLLs do not undergo the strong evolution seen in other active galactic nuclei since it naturally predicts that the space density of BLLs should increase with cosmic time, as shown by recent observations. Numerical models reproduce, with reasonable parameters, the known redshift and magnitude counts of BL Lac objects. It is assumed that radio-quiet as well as radio-loud quasars are capable of generating jets but that jets are snuffed in young radio-quiet objects and only emerge in aged ones. I argue that the observations allow this assumption.

  7. RHIC Au beam in Run 2014

    SciTech Connect (OSTI)

    Zhang, S. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-09-15T23:59:59.000Z

    Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014 is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.

  8. Three regimes of relativistic beam - plasma interaction

    SciTech Connect (OSTI)

    Muggli, P.; Allen, B.; Fang, Y.; Yakimenko, V.; Babzien, M.; Kusche, K.; Fedurin, M.; Vieira, J.; Martins, J.; Silva, L. [Max Planck Institute for Physics, 80805 Munich (Germany) and University of Southern California, Los Angeles, CA 90089 (United States); University of Southern California, Los Angeles, CA 90089 (United States); Brookhaven National Laboratory, Upton, NY 11973 (United States); GoLP/Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado Instituto Superior Tecnico (IST), Technical University of Lisbon, Lisboa (Portugal)

    2012-12-21T23:59:59.000Z

    Three regimes of relativistic beam - plasma interaction can in principle be reached at the ATF depending on the relative transverse and longitudinal size of the electron bunch when compared to the cold plasma collisionless skin depth c?{omega}{sub pe}: the plasma wakefield accelerator (PWFA), the self-modulation instability (SMI), and the current filamentation instability (CFI) regime. In addition, by choosing the bunch density, the linear, quasi-nonlinear and non linear regime of the PWFA can be reached. In the case of the two instabilities, the bunch density determines the growth rate and therefore the occurrence or not of the instability. We briefly describe these three regimes and outline results demonstrating that all these regime have or will be reached experimentally. We also outline planned and possible follow-on experiments.

  9. Fast beam studies of free radical photodissociation

    SciTech Connect (OSTI)

    Neumark, D.M. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01T23:59:59.000Z

    The authors have developed a novel technique for studying the photodissociation spectroscopy and dynamics of free radicals. In these experiments, radicals are generated by laser photodetachment of a fast (6-8 keV) mass-selected negative ion beam. The resulting radicals are photodissociated with a second laser, and the photofragments are collected and detected with high efficiency using a microchannel plate detector. The overall process is: ABC{sup -} {yields} ABC + e{sup -} {yields} A + BC, AB + C. Two types of fragment detection schemes are used. To map out the photodissociation cross-section of the radical, the photodissociation laser is scanned and the total photofragment yield is measured as a function of wavelength. In other experiments, the photodissociation frequency is fixed and the photofragment masses, kinetic energy release, and scattering angle is determined for each photodissociation event.

  10. Beam-powered lunar rover design

    SciTech Connect (OSTI)

    Dagle, J.E.; Coomes, E.P.; Antoniak, Z.I.; Bamberger, J.A.; Bates, J.M.; Chiu, M.A.; Dodge, R.E.; Wise, J.A.

    1992-03-01T23:59:59.000Z

    Manned exploration of our nearest neighbors in the solar systems is the primary goal of the Space Exploration Initiative (SEI). An integral part of any manned lunar or planetary outpost will be a system for manned excursions over the surface of the planet. This report presents a preliminary design for a lunar rover capable of supporting four astronauts on long-duration excursions across the lunar landscape. The distinguishing feature of this rover design is that power is provided to rover via a laser beam from an independent orbiting power satellite. This system design provides very high power availability with minimal mass on the rover vehicle. With this abundance of power, and with a relatively small power-system mass contained in the rover, the vehicle can perform an impressive suite of mission-related activity. The rover might be used as the first outpost for the lunar surface (i.e., a mobile base). A mobile base has the advantage of providing extensive mission activities without the expense of establishing a fixed base. This concept has been referred to as Rove First.'' A manned over, powered through a laser beam, has been designed for travel on the lunar surface for round-trip distances in the range of 1000 km, although the actual distance traveled is not crucial since the propulsion system does not rely on energy storage. The life support system can support a 4-person crew for up to 30 days, and ample power is available for mission-related activities. The 8000-kg rover has 30 kW of continuous power available via a laser transmitter located at the Earth-moon L1 libration point, about 50,000 km above the surface of the moon. This rover, which is designed to operate in either day or night conditions, has the flexibility to perform a variety of power-intensive missions. 24 refs.

  11. Beam-powered lunar rover design

    SciTech Connect (OSTI)

    Dagle, J.E.; Coomes, E.P.; Antoniak, Z.I.; Bamberger, J.A.; Bates, J.M.; Chiu, M.A.; Dodge, R.E.; Wise, J.A.

    1992-03-01T23:59:59.000Z

    Manned exploration of our nearest neighbors in the solar systems is the primary goal of the Space Exploration Initiative (SEI). An integral part of any manned lunar or planetary outpost will be a system for manned excursions over the surface of the planet. This report presents a preliminary design for a lunar rover capable of supporting four astronauts on long-duration excursions across the lunar landscape. The distinguishing feature of this rover design is that power is provided to rover via a laser beam from an independent orbiting power satellite. This system design provides very high power availability with minimal mass on the rover vehicle. With this abundance of power, and with a relatively small power-system mass contained in the rover, the vehicle can perform an impressive suite of mission-related activity. The rover might be used as the first outpost for the lunar surface (i.e., a mobile base). A mobile base has the advantage of providing extensive mission activities without the expense of establishing a fixed base. This concept has been referred to as ``Rove First.`` A manned over, powered through a laser beam, has been designed for travel on the lunar surface for round-trip distances in the range of 1000 km, although the actual distance traveled is not crucial since the propulsion system does not rely on energy storage. The life support system can support a 4-person crew for up to 30 days, and ample power is available for mission-related activities. The 8000-kg rover has 30 kW of continuous power available via a laser transmitter located at the Earth-moon L1 libration point, about 50,000 km above the surface of the moon. This rover, which is designed to operate in either day or night conditions, has the flexibility to perform a variety of power-intensive missions. 24 refs.

  12. LCM2003045 Improved TESLA Optics and Beam Induced

    E-Print Network [OSTI]

    LC­M­2003­045 Improved TESLA Optics and Beam Induced Backgrounds Update Karsten BË?uÃ?er, DESY and Olivier Napoly, CEA/Saclay LCWS 2002, Jeju, Korea Abstract A new tesla optics with l*=5m is under development. An update is given on the simulation of the beam induced backgrounds in the TESLA detector. 1

  13. Determination of beam energy at TESLA using radiative return events

    E-Print Network [OSTI]

    Determination of beam energy at TESLA using radiative return events ARND HINZE DESY Zeuthen at TESLA. It was suggested to use this method to cross check and calibrate the magnet spectrometer used for measurement of the beam energy at TESLA. A preliminary assessment of the statistical and systematic errors

  14. Precision monitoring of relative beam intensity for Mu2e

    SciTech Connect (OSTI)

    Evans, N.J.; Kopp, S.E.; /Texas U.; Prebys, E.; /Fermilab

    2011-04-01T23:59:59.000Z

    For future experiments at the intensity frontier, precise and accurate knowledge of beam time structure will be critical to understanding backgrounds. The proposed Mu2e experiment will utilize {approx}200 ns (FW) bunches of 3 x 10{sup 7} protons at 8 GeV with a bunch-to-bunch period of 1695 ns. The out-of-bunch beam must be suppressed by a factor of 10{sup -10} relative to in-bunch beam and continuously monitored. I propose a Cerenkov-based particle telescope to measure secondary production from beam interactions in a several tens of microns thick foil. Correlating timing information with beam passage will allow the determination of relative beam intensity to arbitrary precision given a sufficiently long integration time. The goal is to verify out-of-bunch extinction to the level 10{sup -6} in the span of several seconds. This will allow near real-time monitoring of the initial extinction of the beam resonantly extracted from Fermilabs Debuncher before a system of AC dipoles and collimators, which will provide the final extinction. The effect on beam emittance is minimal, allowing the necessary continuous measurement. I will present the detector design and some concerns about bunch growth during the resonant extraction.

  15. Title of Dissertation: LASER SWITCHED ELECTRON BEAM MODULATION WITH TERAHERTZ

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of Dissertation: LASER SWITCHED ELECTRON BEAM MODULATION WITH TERAHERTZ APPLICATIONS Jonathan Neumann, PhD 2005 Dissertation Directed By: Dr. Patrick O'Shea, Department of Electrical and Computer Engineering This dissertation describes the exploration of relativistic electron beams modulated

  16. Title of Dissertation: CONTROL AND TRANSPORT OF INTENSE ELECTRON BEAMS

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of Dissertation: CONTROL AND TRANSPORT OF INTENSE ELECTRON BEAMS Hui Li, Doctor of Philosophy, 2004 Dissertation Directed By: Professor, Patrick G. O'Shea Department of Electrical and Computer throughout the strong focusing lattice. We describe in this dissertation the main beam control techniques

  17. atlas test beam: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    atlas test beam First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Test beam results of ATLAS Pixel...

  18. Etching of polycrystalline diamond films by electron beam assisted plasma

    E-Print Network [OSTI]

    Rocca, Jorge J.

    Etching of polycrystalline diamond films by electron beam assisted plasma Koji Kobashi, Shigeaki) Polycrystalline diamond films were processed in a direct current plasma produced by a self-focused electron beam that the etching apparatus used was capable of forming at least a 5-mm wide pattern of polycrystalline diamond film

  19. Intensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective

    E-Print Network [OSTI]

    Coello, Carlos A. Coello

    Intensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective Evolutionary will be di- agnosed with cancer. Half of these will be treated with radiation therapy [1]. In teletherapy or external radiotherapy beams of penetrating radiation are directed at the tumor. Along their path through

  20. Electron beam melting and refining state of the art 1995

    SciTech Connect (OSTI)

    Bakish, R. [ed.

    1995-12-31T23:59:59.000Z

    This is the proceedings of the Electron Beam Melting and Refining - State of the Art 1995 Conference. It contains 23 of the 30 scheduled papers. Papers cover an array of electron beam melting applications, from industrial plating of metal strip, through government work on manufacturing and processing fissile alloys. Separate abstracts have been prepared for articles from this proceedings.

  1. ECRH microwave beam broadening in the edge turbulent plasma

    SciTech Connect (OSTI)

    Sysoeva, E. V.; Gusakov, E. Z.; Popov, A. Yu. [Ioffe Institute, St. Petersburg, Russia and RL PAT SPbSPU, St. Petersburg (Russian Federation); Silva, F. da [Institute of Plasmas and Nuclear Fusion, IST, Lisbon (Portugal); Heuraux, S. [IJL UMR-7198 CNRS-Université de Lorraine, BP70239, 54506 Vandoeuvre Cedex (France)

    2014-02-12T23:59:59.000Z

    The influence of turbulent plasma density fluctuations on angular and spatial beam width is treated analytically in the framework of WKB based eikonal method. Reasonable agreement of analytical and numerical treatment results is demonstrated within the domain of quasi-optical approximation validity. Significant broadening of microwave beams is predicted for future ECRH experiments at ITER.

  2. PIC MODELING: Measuring Ion Beam Current Density in the

    E-Print Network [OSTI]

    Kaganovich, Igor

    ;Collaborators: R. C. Davidson, P. C. Efthimion, E. P. Gilson (PPPL) S. S. Yu, P. K. Roy, F. M. Bieniosek, W. L) Converging ion beam Chamber Wall #12;3The Neutralized Transport Experiment was a success 400 kV Marx & Fire Injector #12;5Neutralized drift compression modeled with a particle-in-cell code (LSP) K+ ion beam

  3. VIBRATION CONTROL IN A SMART BEAM Daniel R. Fay*

    E-Print Network [OSTI]

    Patil, Mayuresh

    activity and nearby motorized equipment. In this case, disturbance is produced using a white noise signal for vibration suppression, stability augmentation, and noise reduction in beam-like aerodynamic surfacesVIBRATION CONTROL IN A SMART BEAM Daniel R. Fay* Widener University, Chester, Pennsylvania Abstract

  4. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    SciTech Connect (OSTI)

    Evtushenko, Pavel E. [JLAB; Douglas, David R. [JLAB

    2013-06-01T23:59:59.000Z

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  5. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    SciTech Connect (OSTI)

    Evtushenko, Pavel [JLAB; Douglas, David R. [JLAB; Legg, Robert A. [JLAB; Tennant, Christopher D. [JLAB

    2013-05-01T23:59:59.000Z

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  6. A new design for the CERN to Frjus neutrino beam

    E-Print Network [OSTI]

    McDonald, Kirk

    flow configuration Packed bed target front end Model Parameters Proton Beam Energy = 4.5GeV Beam sigma sphere material : Beryllium or Titanium Coolant = Helium at 10 bar pressure Titanium alloy cannister containing packed bed of titanium or beryllium spheres Cannister perforated with elipitical holes graded

  7. BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT

    E-Print Network [OSTI]

    BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D-22607 and differential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass such as Higgs boson mass, decay branching fractions and production rate. However, most of these studies did

  8. Linear Tuning and Estimates for the Initial Beam Based Alignment

    E-Print Network [OSTI]

    of the magnetic centre of the magnets with respect to the local BPM (i.e. determination of BPM offsets), and 2 is "zeroed" at each down stream BPM. The position of the beam with respect to the magnet centres is then given by the accuracy to which the BPM offset was determined (point 1 above.) After beam-based alignment

  9. Beam Test of the Superstructure Instrumentation Requirements for

    E-Print Network [OSTI]

    of the HOM-coupler signals ¯ Measurement of the BPM signals ¯ Measurement of beam orbit and energy #12 procedure "HOM Search". #12;Measurement of the BPM signals 8 Beam Test of the Superstructure Measurement of the BPM signals Beside (?!) the re-entrant cavity BPM (C. Magne), a stripline BPM (DESY

  10. Development of a focused ion beam micromachining system

    SciTech Connect (OSTI)

    Pellerin, J.G.; Griffis, D.; Russell, P.E.

    1988-12-01T23:59:59.000Z

    Focused ion beams are currently being investigated for many submicron fabrication and analytical purposes. An FIB micromachining system consisting of a UHV vacuum system, a liquid metal ion gun, and a control and data acquisition computer has been constructed. This system is being used to develop nanofabrication and nanomachining techniques involving focused ion beams and scanning tunneling microscopes.

  11. Historical perspective of laser beam shaping David L. Shealy

    E-Print Network [OSTI]

    Shealy, David L.

    of -- solar radiation. The literature is rich with reports of various optical systems used as solar collectors-focusing) optics used as solar collectors, including an ideal light collector,9, 10 which concentrates a beam symmetric reflective solar collector, which can heat the collector surface in a prescribed manner. Beam

  12. Propagation Beam Consideration for 3D THz Computed Tomography

    E-Print Network [OSTI]

    Boyer, Edmond

    Propagation Beam Consideration for 3D THz Computed Tomography B. Recur, 1, J.P. Guillet, 2 I. Manek, "Refraction losses in terahertz computed tomography," Opt. Commun. 283, 2050­2055 (2010). 8. S. Nadar, H of the beam propagation is developed according to the physical properties of THz waves used in THz computed

  13. Dual beam translator for use in Laser Doppler anemometry

    DOE Patents [OSTI]

    Brudnoy, D.M.

    1984-04-12T23:59:59.000Z

    A method and apparatus for selectively translating the path of at least one pair of light beams in a Laser Doppler anemometry device whereby the light paths are translated in a direction parallel to the original beam paths so as to enable attainment of spacial coincidence of the two intersection volumes and permit accurate measurements of Reynolds shear stress.

  14. Apparatus for monitoring X-ray beam alignment

    DOE Patents [OSTI]

    Steinmeyer, P.A.

    1991-10-08T23:59:59.000Z

    A self-contained, hand-held apparatus is provided for monitoring alignment of an X-ray beam in an instrument employing an X-ray source. The apparatus includes a transducer assembly containing a photoresistor for providing a range of electrical signals responsive to a range of X-ray beam intensities from the X-ray beam being aligned. A circuit, powered by a 7.5 VDC power supply and containing an audio frequency pulse generator whose frequency varies with the resistance of the photoresistor, is provided for generating a range of audible sounds. A portion of the audible range corresponds to low X-ray beam intensity. Another portion of the audible range corresponds to high X-ray beam intensity. The transducer assembly may include an a photoresistor, a thin layer of X-ray fluorescent material, and a filter layer transparent to X-rays but opaque to visible light. X-rays from the beam undergoing alignment penetrate the filter layer and excite the layer of fluorescent material. The light emitted from the fluorescent material alters the resistance of the photoresistor which is in the electrical circuit including the audio pulse generator and a speaker. In employing the apparatus, the X-ray beam is aligned to a complete alignment by adjusting the X-ray beam to produce an audible sound of the maximum frequency. 2 figures.

  15. NOx reduction by electron beam-produced nitrogen atom injection

    DOE Patents [OSTI]

    Penetrante, Bernardino M. (San Ramon, CA)

    2002-01-01T23:59:59.000Z

    Deactivated atomic nitrogen generated by an electron beam from a gas stream containing more than 99% N.sub.2 is injected at low temperatures into an engine exhaust to reduce NOx emissions. High NOx reduction efficiency is achieved with compact electron beam devices without use of a catalyst.

  16. LATTICE/hor ellipsis/a beam transport program

    SciTech Connect (OSTI)

    Staples, J.

    1987-06-01T23:59:59.000Z

    LATTICE is a computer program that calculates the first order characteristics of synchrotrons and beam transport systems. The program uses matrix algebra to calculate the propagation of the betatron (Twiss) parameters along a beam line. The program draws on ideas from several older programs, notably Transport and Synch, adds many new ones and incorporates them into an interactive, user-friendly program. LATTICE will calculate the matched functions of a synchrotron lattice and display them in a number of ways, including a high resolution Tektronix graphics display. An optimizer is included to adjust selected element parameters so the beam meets a set of constraints. LATTICE is a first order program, but the effect of sextupoles on the chromaticity of a synchrotron lattice is included, and the optimizer will set the sextupole strengths for zero chromaticity. The program will also calculate the characteristics of beam transport systems. In this mode, the beam parameters, defined at the start of the transport line, are propagated through to the end. LATTICE has two distinct modes: the lattice mode which finds the matched functions of a synchrotron, and the transport mode which propagates a predefined beam through a beam line. However, each mode can be used for either type of problem: the transport mode may be used to calculate an insertion for a synchrotron lattice, and the lattice mode may be used to calculate the characteristics of a long periodic beam transport system.

  17. Vortex stabilized electron beam compressed fusion grade plasma

    SciTech Connect (OSTI)

    Hershcovitch, Ady [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-03-19T23:59:59.000Z

    Most inertial confinement fusion schemes are comprised of highly compressed dense plasmas. Those schemes involve short, extremely high power, short pulses of beams (lasers, particles) applied to lower density plasmas or solid pellets. An alternative approach could be to shoot an intense electron beam through very dense, atmospheric pressure, vortex stabilized plasma.

  18. Self-Consistent parallel multi bunch beam-beam simulation using a grid-multipole method

    E-Print Network [OSTI]

    Jones, F; Pieloni, T

    2010-01-01T23:59:59.000Z

    The simulation code COMBI has been developed to enable the study of coherent beam-beam effects in the full collision scenario of the LHC, with multiple bunches interacting at multiple crossing points over many turns. The parallel version of COMBI was first implemented using a soft-Gaussian collision model which entails minimal communication between worker processes. Recently we have extended the code to a fully self-consistent collision model using a Grid-Multipole method, which allows worker processes to exchange charge and field information in a compact form which minimizes communication overhead. In this paper we describe the Grid-Multipole technique and its adaptation to the parallel environment through pre- and post-processing of charge and grid data. Performance measurements in a Myrinet cluster environment will be given.

  19. Recent progress in tailoring trap-based positron beams

    SciTech Connect (OSTI)

    Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M. [Physics Department, University of California, San Diego La Jolla CA 92093-0319 (United States)

    2013-03-19T23:59:59.000Z

    Recent progress is described to implement two approaches to specially tailor trap-based positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 {>=} T {>=} 300 K. These simulations are also used to predict beam performance for cryogenically cooled positrons. Experiments and simulations are also presented to understand the properties of beams formed when plasmas are tailored in a PM trap in a 5 tesla magnetic field, then non-adiabatically extracted from the field using a specially designed high-permeability grid to create a new class of electrostatically guided beams.

  20. Evaluation of an Impulse Gravity Generator Based Beamed Propulsion Concept

    E-Print Network [OSTI]

    Giovanni Modanese; Chris Y. Taylor

    2002-09-05T23:59:59.000Z

    This paper analyzes the suitability of a beamed propulsion concept having properties consistent with the impulse gravity generator described by Podkletnov et al. [physics/0108005]. The use of this propulsion concept for orbital maneuver, Earth-to-orbit, interplanetary, and interstellar applications based on presently available experimental results and theory is considered, and areas for future research needed to better characterize this phenomenon are discussed. A beam of radiation or particles with the properties described for the impulse gravity generator would appear to be an excellent candidate for use in beamed spacecraft propulsion. Besides the usual benefits of beamed propulsion, it would not need sails or other special spacecraft components to function, could safely provide high accelerations to delicate components, and might operate at higher efficiencies than other beamed propulsion concepts.