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Sample records for accelerating structure design

  1. Design of the detuned accelerator structure

    International Nuclear Information System (INIS)

    Wang, J.W.; Nelson, E.M.

    1993-05-01

    This is a summary of the design procedure for the detuned accelerator structure for SLAC's Next Linear Collider (NLC) program. The 11.424 GHz accelerating mode of each cavity must be synchronous with the beam. The distribution of the disk thicknesses and lowest synchronous dipole mode frequencies of the cavities in the structure is Gaussian in order to reduce the effect of wake fields. The finite element field solver YAP calculated the accelerating mode frequency and the lowest synchronous dipole mode frequency for various cavity diameters, aperture diameters and disk thicknesses. Polynomial 3-parameter fits are used to calculate the dimensions for a 1.8 m detuned structure. The program SUPERFISH was used to calculate the shunt impedances, quality factors and group velocities. The RF parameters of the section like filling time, attenuation factor, accelerating gradient and maximum surface field along the section are evaluated. Error estimates will be discussed and comparisons with conventional constant gradient and constant impedance structures will be presented

  2. Design of the accelerating structures for FMIT

    International Nuclear Information System (INIS)

    Liska, D.; Schamaun, R.; Potter, C.; Fuller, C.; Clark, D.; Greenwood, D.; Frank, J.

    1979-01-01

    Design considerations and concepts are presented for the accelerating structures for the Fusion Materials Irradiation Test (FMIT) Facility. These structures consist of three major units: 0.1- to 2-MeV radio-frequency quadrupole based on the Russian concept, a 2- to 35-MeV drift-tube linac made up of two separate tanks designed to generate either 20- or 35-MeV beams, and an energy dispersion cavity capable of spreading the energy of the beam slightly to ease thermal loading in the target. Because of probable beam activation, the drift-tube linac is designed so that alignment and maintenance do not require manned entry into the tanks. This conservatism also led to the choice of a conventional vacuum system and has influenced the choice of many of the rf interface components. The high-powered FMIT machine is very heavily beam loaded and delivers a 100-mA continuous duty deuteron beam to a flowing liquid lithium target. The power on target is 3.5 MW deposited in a 1 x 3 cm spot. Because of the critical importance of the low energy section of this accelerator on beam spill in the machine, a 5-MeV prototype will be constructed and tested at the Los Alamos Scientific Laboratory

  3. Design and fabrication of a continuous wave electron accelerating structure

    International Nuclear Information System (INIS)

    Takahashi, Jiro

    1997-01-01

    The Physics Institute of Sao Paulo University, SP, Brazil is fabricating a 31 MeV cw racetrack microtron (RTM) designed for nuclear physics research. This is a two-stage microtron that includes a 1.93 MeV injector linac feeding a five-turn microtron booster. After 28 turns, the main microtron delivers a 31 MeV continuous electron beam. The objective of this work is the development and fabrication of an advanced, beta=l, cw accelerating structure for the main microtron. The accelerating structure will be a side-coupled structure (SCS). We have chosen this kind of cavity, because it presents good vacuum properties, allows operation at higher accelerating electric fields and has a shunt impedance better than 81 MQ/m, with a high coupling factor ( 3 - 5%). The engineering design is the Los Alamos one. There will be two tuning plungers placed at both ends of the accelerating structure. They automatically and quickly compensate for the variation in the resonance frequency caused by changes in the structure temperature. Our design represents an advanced accelerating structure with the optimum SCS properties coexisting with the plunger's good tuning properties. (author)

  4. Design and Construction of the Linac4 Accelerating Structures

    CERN Document Server

    Gerigk, F; Dallocchio, A; Favre, G; Vretenar, M; Wegner, R; Tirado, P Ugena; Rossi, C; Riffaud, B; Ramberger, S; Polini, M; Gentini, L; Geisser, JM; Giguet, JM; Mathot, S; Naumenko, M; Kendjebulatov, E; Tribendis, A; Kryuchkov, Ya

    2013-01-01

    The Linac4 project at CERN is at an advanced state of construction. Prototypes and/or operational modules of the different types of accelerating structures (RFQ, buncher, DTL, CCDTL, and PIMS) have been built and are presently tested. This paper gives the status of the cavity production and reviews the RF and mechanical design of the various structure types. Furthermore the production experience and the first test results shall be presented.

  5. Vacuum design for the disk-and-washer accelerator structure

    International Nuclear Information System (INIS)

    Ruhe, J.R.; Hansborough, L.D.

    1982-02-01

    The disk-and-washer (DAW) accelerator structure is being developed for several applications. Because of its complicated geometry and newness, vacuum calculations for the DAW accelerator structure are not yet formalized. The applicable vacuum equations for this structure are presented and correlations for it have been made with the vacuum data from the Clinton P. Anderson Meson Physics Facility side-coupled accelerator structure. A calculation is presented for the DAW structure proposed for the Pion Generator for Medical Irradiations (PIGMI) accelerator

  6. Design of Accelerator Online Simulator Server Using Structured Data

    International Nuclear Information System (INIS)

    Shen, Guobao

    2012-01-01

    Model based control plays an important role for a modern accelerator during beam commissioning, beam study, and even daily operation. With a realistic model, beam behaviour can be predicted and therefore effectively controlled. The approach used by most current high level application environments is to use a built-in simulation engine and feed a realistic model into that simulation engine. Instead of this traditional monolithic structure, a new approach using a client-server architecture is under development. An on-line simulator server is accessed via network accessible structured data. With this approach, a user can easily access multiple simulation codes. This paper describes the design, implementation, and current status of PVData, which defines the structured data, and PVAccess, which provides network access to the structured data.

  7. Low-field accelerator structure couplers and design techniques

    Directory of Open Access Journals (Sweden)

    Christopher Nantista

    2004-07-01

    Full Text Available Recent experience with X-band accelerator structure development has shown the rf input coupler to be the region most prone to rf breakdown and degradation, effectively limiting the operating gradient. A major factor in this appears to be high magnetic fields at the sharp edges of the coupling irises. As a first response to this problem, couplers with rounded and thickened iris horns have been employed and successfully tested at high power. To further reduce fields for higher power flow, conceptually new coupler designs have been developed, in which power is coupled through the broad wall of the feed waveguide, rather than through terminating irises. A “mode-launcher” coupler, which launches the TM_{01} mode in circular waveguide before coupling through a matching cell into the main structure, has been tested with great success. With peak surface fields below those in the body of the structure, this coupler represented a breakthrough in the Next Linear Collider structure program. The design of this coupler and of variations which use beam line space more efficiently are described here. The latter include a coupler in which power passes directly through an iris in the broad wall of the rectangular waveguide into a matching cell, also successfully implemented, and a variation which makes the waveguide itself an accelerating cell. We also discuss in some detail a couple of techniques for matching such couplers to traveling-wave structures using a field solver. The first exploits the cell number independence of a traveling-wave match, and the second optimizes using the fields of an internally driven structure.

  8. Simulation and design of the photonic crystal microwave accelerating structure

    International Nuclear Information System (INIS)

    Song Ruiying; Wu Congfeng; He Xiaodong; Dong Sai

    2007-01-01

    The authors have derived the global band gaps for general two-dimensional (2D) photonic crystal microwave accelerating structures formed by square or triangular arrays of metal posts. A coordinate-space, finite-difference code was used to calculate the complete dispersion curves for the lattices. The fundamental and higher frequency global photonic band gaps were determined numerically. The structure formed by triangular arrays of metal posts with a missing rod at the center has advantages of higher-order-modes (HOM) suppression and main mode restriction under the condition of a/b<0.2. The relationship between the RF properties and the geometrical parameters have been studied for the 9.37 GHz photonic crystal accelerating structure. The Rs, Q, Rs/Q of the new structure may be comparable to the disk-loaded accelerating structure. (authors)

  9. Design of the Compact Linear Collider main linac accelerating structure made from two halves

    Directory of Open Access Journals (Sweden)

    Hao Zha

    2017-04-01

    Full Text Available Milling on two longitudinally split halves is one method to manufacture accelerating structures. This method is simple and allows one to avoid electromagnetic fields at bonding joints, making it attractive in manufacturing high-gradient accelerating structures. An X-band structure design with strong wakefield damping based on this manufacturing approach is studied in this work as an alternative design for the Compact Linear Collider (CLIC main linac accelerating structures. The geometry of the structure is optimized to greatly reduce the surface fields, improve the efficiency, and suppress the wakefield. This structure features the baseline design of the CLIC main linac with additional advantages. This study may serve as a reference for designing other high frequency-band corrugated structures.

  10. Design and fabrication of a traveling-wave muffin-tin accelerating structure at 90 GHz

    International Nuclear Information System (INIS)

    Chou, P.J.; Bowden, G.B.; Copeland, M.R.; Menegat, A.; Siemann, R.H.

    1997-05-01

    A prototype of a muffin-tin accelerating structure operating at 32 times the SLAC frequency (2.856 GHz) was built for research in high gradient acceleration. A traveling-wave design with single input and output feeds was chosen for the prototype which was fabricated by wire electrodischarge machining. Features of the mechanical design for the prototype are described. Design improvements are presented including considerations of cooling and vacuum

  11. Engineering design and fabrication of tapered damped X-Band accelerating structures

    CERN Document Server

    Solodko, A; Gudkov, D; Riddone, G; Grudiev, A; Atieh, S; Taborelli, M

    2011-01-01

    The accelerating structures (AS) are one of the main components of the Compact LInear Collider (CLIC), under study at CERN. Each accelerating structure contains about 30 copper discs, which form the accelerating cavity. The requirements of different technical systems, such as vacuum and cooling, have to be considered during the engineering design. A fully featured AS is very challenging and requires several technologies. Different damping methods, waveguides, vacuum manifolds, slots and chokes, result in various design configurations. In the CLIC AS each cell is damped by means of four waveguides coupled to the cell. The vacuum manifolds combine a number of functions such as damping, vacuum pumping and cooling. A silicon carbide absorber, fixed inside of each manifold, is required for effective damping of Higher Order Modes (HOMs). This paper describes the engineering design of the X-band AS with damping material, and focuses on few technical solutions.

  12. Design of a choke-mode damped accelerating structure for CLIC Main LINAC

    CERN Document Server

    Shi, J; Grudiev, A; Wuensch, W; Tang, C; Chen, H; Huang, W

    2011-01-01

    Choke-mode damped accelerating structures are being studied as an alternative to the baseline structure of the compact linear collider (CLIC) by a CERN-Tsinghua collaboration. Choke-mode structures hold the potential for much lower levels of pulsed surface heating and, since milling is not needed, reduced cost. Structures with radial choke attached are simulated in GdfidL to investigate the damping of the transverse wake. The first pass-band of the dipole modes is well damped, while the higher order dipole modes are possibly reflected by the choke. Therefore, the geometry of the choke is tuned to minimize the reflection of these higher order dipole modes. Based on this damping scheme, an accelerating structure with the same iris dimensions as the nominal CLIC design but with choke-mode damping has been designed. A prototype structure will be manufactured and high power tested in the near future.

  13. Design and construction of planar mm-wave accelerating cavity structures

    International Nuclear Information System (INIS)

    Kang, Y.W.; Kustom, R.L.; Nassiri, A.; Song, J.J.; Feineman, A.D.; Illinois Univ., Chicago, IL

    1995-01-01

    Feasibility studies on the planar millimeter-wave cavity structures have been made. The structures could be used for linear accelerators, free electron lasers, mm-wave amplifiers, or mm-wave undulators. The cavity structures are intended to be manufactured by using DXL (deep x-ray lithography) microfabrication technology. The frequency of operation can be about 30GHz to 300GHz. For most applications, a complete structure consists of two identical planar half structures put together face-to-face. Construction and properties of constant gradient structures that have been investigated so far will be discussed. These cavity structures have been designed for 120GHz 2π/3-mode operation

  14. Design and construction of multi-port solid state structure for the Rhodotron accelerator

    International Nuclear Information System (INIS)

    Poursaleh, A.M.; Jabbari, I.; Khalafi, H.

    2017-01-01

    RF generation and method used for coupling power to the acceleration cavity are important issues in the RF accelerators. In this study, a high power vacuum tube was replaced with several medium power solid state amplifiers coupled through a multi-port structure in the Rhodotron-TT200 accelerator. To this end, a multi-port structure was implemented on a small aluminum model cavity for 1 to 9 ports and all main parameters affecting return loss, quality factor, coupling coefficient and RF power were investigated by calculation, simulation and experimental tests. Then, three 20 kW solid state amplifiers were designed and constructed. The outputs of these amplifiers were coupled to the Rhodotron acceleration cavity by three input ports based on the results obtained from the model cavity for generation of 5 MeV electron beam. In this method, several smaller amplifiers were used instead of a single high power amplifier. As such, acceleration cavity plays the role of power combiner in addition to its primary role and there is no need to a high power combiner. The results showed that the number of ports, port positions, angle between ports and phase of input signals, significantly affect the acceleration electrical field in the cavity. Also, experimental tests revealed that three constructed RF power supplies are enough for the generation of 5 MeV electron beam in the Rhodotron accelerator. Considering the advantages of the solid state amplifiers, application of multi-port structure and solid state amplifiers could be expanded in the industrial electron accelerators.

  15. Design and construction of multi-port solid state structure for the Rhodotron accelerator

    Science.gov (United States)

    Poursaleh, A. M.; Jabbari, I.; Khalafi, H.

    2017-04-01

    RF generation and method used for coupling power to the acceleration cavity are important issues in the RF accelerators. In this study, a high power vacuum tube was replaced with several medium power solid state amplifiers coupled through a multi-port structure in the Rhodotron-TT200 accelerator. To this end, a multi-port structure was implemented on a small aluminum model cavity for 1 to 9 ports and all main parameters affecting return loss, quality factor, coupling coefficient and RF power were investigated by calculation, simulation and experimental tests. Then, three 20 kW solid state amplifiers were designed and constructed. The outputs of these amplifiers were coupled to the Rhodotron acceleration cavity by three input ports based on the results obtained from the model cavity for generation of 5 MeV electron beam. In this method, several smaller amplifiers were used instead of a single high power amplifier. As such, acceleration cavity plays the role of power combiner in addition to its primary role and there is no need to a high power combiner. The results showed that the number of ports, port positions, angle between ports and phase of input signals, significantly affect the acceleration electrical field in the cavity. Also, experimental tests revealed that three constructed RF power supplies are enough for the generation of 5 MeV electron beam in the Rhodotron accelerator. Considering the advantages of the solid state amplifiers, application of multi-port structure and solid state amplifiers could be expanded in the industrial electron accelerators.

  16. Conceptual Design of Dielectric Accelerating Structures for Intense Neutron and Monochromatic X-ray Sources

    Science.gov (United States)

    Blanovsky, Anatoly

    2004-12-01

    Bright compact photon sources, which utilize electron beam interaction with periodic structures, may benefit a broad range of medical, industrial and scientific applications. A class of dielectric-loaded periodic structures for hard and soft X-ray production has been proposed that would provide a high accelerating gradient when excited by an external RF and/or primary electron beam. Target-distributed accelerators (TDA), in which an additional electric field compensates for lost beam energy in internal targets, have been shown to provide the necessary means to drive a high flux subcritical reactor (HFSR) for nuclear waste transmutation. The TDA may also be suitable for positron and nuclear isomer production, X-ray lithography and monochromatic computer tomography. One of the early assumptions of the theory of dielectric wake-field acceleration was that, in electrodynamics, the vector potential was proportional to the scalar potential. The analysis takes into consideration a wide range of TDA design aspects including the wave model of observed phenomena, a layered compound separated by a Van der Waals gap and a compact energy source based on fission electric cells (FEC) with a multistage collector. The FEC is a high-voltage power source that directly converts the kinetic energy of the fission fragments into electrical potential of about 2MV.

  17. Accelerator structure work for NLC

    International Nuclear Information System (INIS)

    Miller, R.H.; Adolphsen, C.; Bane, K.L.F.; Deruyter, H.; Farkas, Z.D.; Hoag, H.A.; Holtkamp, N.; Lavine, T.; Loew, G.A.; Nelson, E.M.; Palmer, R.B.; Paterson, J.M.; Ruth, R.D.; Thompson, K.A.; Vlieks, A.; Wang, J.W.; Wilson, P.B.; Gluckstern, R.; Ko, K.; Kroll, N.; California Univ., San Diego, La Jolla, CA

    1992-07-01

    The NLC design achieves high luminosity with multiple bunches in each RF pulse. Acceleration of a train of bunches without emittance growth requires control of long range dipole wakefields. SLAC is pursuing a structure design which suppresses the effect of wakefields by varying the physical dimensions of successive cells of the disk-loaded traveling wave structure in a manner which spreads the frequencies of the higher mode while retaining the synchronism between the electrons and the accelerating mode. The wakefields of structures incorporating higher mode detuning have been measured at the Accelerator Test Facility at Argonne. Mechanical design and brazing techniques which avoid getting brazing alloy into the interior of the accelerator are being studied. A test facility for high-power testing of these structures is complete and high power testing has begun

  18. Impact of a flattening filter free linear accelerator on structural shielding design

    International Nuclear Information System (INIS)

    Jank, Julia; Kragl, Gabriele; Georg, Dietmar; Medical University of Vienna

    2014-01-01

    Purpose: The present study aimed to assess the effects of a flattening filter free medical accelerator on structural shielding demands of a treatment vault of a medical linear accelerator. We tried to answer the question, to what extent the required thickness of the shielding barriers can be reduced if instead of the standard flattened photon beams unflattened ones are used. Material and Methods: We chose both an experimental as well as a theoretical approach. On the one hand we measured photon dose rates at protected places outside the treatment room and compared the obtained results for flattened and unflattened beams. On the other hand we complied with international guidelines for adequate treatment vault design and calculated the shielding barriers according to the therein given specifications. Measurements were performed with an Elekta Precise trademark linac providing nominal photon energies of 6 and 10 MV. This machine underwent already earlier some modifications in order to be able to operate both with and without a flattening filter. Photon dose rates were measured with a LB133-1 dose rate meter manufactured by Berthold. To calculate the thickness of shielding barriers we referred to the Austrian standard OeNORM S 5216 and to the US American NCRP Report No. 151. Results: We determined a substantial photon dose rate reduction for all measurement points and photon energies. For unflattened 6 MV beams a reduction factor ranging from 1.4 to 1.8 was identified. The corresponding values for unflattened 10 MV beams were 2.1 and 3.2. The performed shielding calculations indicated the same tendency: For all relevant radiation components we found a reduction in shielding thickness when unflattened beams were used. The required thickness of primary barriers was reduced up to 8.0%, the thickness of secondary barriers up to 11.4%, respectively. Conclusions: For an adequate dimensioning of treatment vault shielding barriers it is by no means irrelevant if the

  19. Design, realization and test of C-band accelerating structures for the SPARC-LAB linac energy upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Alesini, D.; Bellaveglia, M.; Biagini, M.E.; Boni, R. [INFN Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044, Frascati (Italy); Brönnimann, M. [Paul Scherrer Institut, 5232 Villigen (Switzerland); Cardelli, F. [INFN Sezione di Roma, P.le Aldo Moro 2, 00185, Roma (Italy); Università di Roma “La Sapienza”, P.le Aldo Moro 2, 00185, Roma (Italy); Chimenti, P.; Clementi, R.; Di Pirro, G.; Di Raddo, R.; Ferrario, M. [INFN Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044, Frascati (Italy); Ficcadenti, L. [INFN Sezione di Roma, P.le Aldo Moro 2, 00185, Roma (Italy); Università di Roma “La Sapienza”, P.le Aldo Moro 2, 00185, Roma (Italy); Gallo, A. [INFN Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044, Frascati (Italy); Kalt, R. [Paul Scherrer Institut, 5232 Villigen (Switzerland); Lollo, V. [INFN Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044, Frascati (Italy); Palumbo, L. [INFN Sezione di Roma, P.le Aldo Moro 2, 00185, Roma (Italy); Università di Roma “La Sapienza”, P.le Aldo Moro 2, 00185, Roma (Italy); Piersanti, L., E-mail: luca.piersanti@lnf.infn.it [INFN Sezione di Roma, P.le Aldo Moro 2, 00185, Roma (Italy); Università di Roma “La Sapienza”, P.le Aldo Moro 2, 00185, Roma (Italy); Schilcher, T. [Paul Scherrer Institut, 5232 Villigen (Switzerland)

    2016-11-21

    The energy upgrade of the SPARC-LAB photo-injector at LNF-INFN (Frascati, Italy) has been originally conceived replacing one low gradient (13 MV/m) 3 m long SLAC type S-band traveling wave (TW) section with two 1.4 m long C-band accelerating sections. Due to the higher gradients reached by such structures, a higher energy beam can be obtained within the same accelerator footprint length. The use of C-band structures for electron acceleration has been adopted in a few FEL linacs in the world, among others, the Japanese Free Electron Laser at SPring-8 and the SwissFEL at Paul Scherrer Institute (PSI). The C-band sections are traveling wave, constant impedance structures with symmetric input and output axial couplers. Their design has been optimized for the operation with a SLED RF pulse compressor. In this paper we briefly review their design criteria and we focus on the construction, tuning, low and high-power RF tests. We also illustrate the design and realization of the dedicated low level RF system that has been done in collaboration with PSI in the framework of the EU TIARA project. Preliminary experimental results appear to confirm the operation of such structures with accelerating gradients larger than 35 MV/m.

  20. Analytical approach and scaling laws in the design of disk-loaded travelling wave accelerating structures

    International Nuclear Information System (INIS)

    Gao, J.

    1993-09-01

    Starting from a single resonant rf cavity, disk-loaded travelling (forward or backward) wave accelerating structures' properties are determined by rather simple analytical formulae. They include the coupling coefficient K in the dispersion relation, group velocity v g , shunt impedance R, wake potential W (longitudinal and transverse), the coupling coefficient β of the coupler cavity and the coupler cavity axis shift δ r which is introduced to compensate the asymmetry caused by the coupling aperture. (author) 12 refs., 18 figs

  1. An algorithm for the design and tuning of RF accelerating structures with variable cell lengths

    Science.gov (United States)

    Lal, Shankar; Pant, K. K.

    2018-05-01

    An algorithm is proposed for the design of a π mode standing wave buncher structure with variable cell lengths. It employs a two-parameter, multi-step approach for the design of the structure with desired resonant frequency and field flatness. The algorithm, along with analytical scaling laws for the design of the RF power coupling slot, makes it possible to accurately design the structure employing a freely available electromagnetic code like SUPERFISH. To compensate for machining errors, a tuning method has been devised to achieve desired RF parameters for the structure, which has been qualified by the successful tuning of a 7-cell buncher to π mode frequency of 2856 MHz with field flatness variable cell lengths.

  2. Design study of high gradient, low impedance accelerating structures for the FERMI free electron laser linac upgrade

    Science.gov (United States)

    Shafqat, N.; Di Mitri, S.; Serpico, C.; Nicastro, S.

    2017-09-01

    The FERMI free-electron laser (FEL) of Elettra Sincrotrone Trieste, Italy, is a user facility driven by a 1.5 GeV 10-50 Hz S-band radiofrequency linear accelerator (linac), and it is based on an external laser seeding scheme that allows lasing at the shortest fundamental wavelength of 4 nm. An increase of the beam energy to 1.8 GeV at a tolerable breakdown rate, and an improvement of the final beam quality is desired in order to allow either lasing at 4 nm with a higher flux, or lasing at shorter wavelengths. This article presents the impedance analysis of newly designed S-band accelerating structures, for replacement of the existing backward travelling wave structures (BTWS) in the last portion of the FERMI linac. The new structure design promises higher accelerating gradient and lower impedance than those of the existing BTWS. Particle tracking simulations show that, with the linac upgrade, the beam relative energy spread, its linear and nonlinear z-correlation internal to the bunch, and the beam transverse emittances can be made smaller than the ones in the present configuration, with expected advantage to the FEL performance. The repercussion of the upgrade on the linac quadrupole magnets setting, for a pre-determined electron beam optics, is also considered.

  3. Accelerator structure development for NLC

    International Nuclear Information System (INIS)

    Hoag, H.A.; Deruyter, H.; Pearson, C.; Ruth, R.D.; Wang, J.W.; Schaefer, J.

    1993-04-01

    In the program of work directed towards the development of an X-Band Next Linear Collider accelerator structure, two different test accelerator sections have been completed, and a third is being fabricated. The first is a simple 30-cell constant-impedance section in which no special attention was given to surface finish, pumping, and alignment. The second is an 86-cell section in which the cells were precision diamond-turned by Texas Instruments Inc. The structure has internal water-cooling and vacuum pumping manifolds. Some design details are given for the third section, which is a 206-cell structure with cavities dimensioned to give a Gaussian distribution of dipole mode frequencies. It has conventional-machining surface finishes and external water and pumping manifolds. Component design, fabrication, and assembly brazing are described for the first two experimental sections

  4. Plasma-based accelerator structures

    International Nuclear Information System (INIS)

    Schroeder, Carl B.

    1999-01-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas

  5. MEQALAC rf accelerating structure

    International Nuclear Information System (INIS)

    Keane, J.; Brodowski, J.

    1981-01-01

    A prototype MEQALAC capable of replacing the Cockcroft Walton pre-injector at BNL is being fabricated. Ten milliamperes of H - beam supplied from a source sitting at a potential of -40 kilovolt is to be accelerated to 750 keV. This energy gain is provided by a 200 Megahertz accelerating system rather than the normal dc acceleration. Substantial size and cost reduction would be realized by such a system over conventional pre-accelerator systems

  6. Software for virtual accelerator designing

    International Nuclear Information System (INIS)

    Kulabukhova, N.; Ivanov, A.; Korkhov, V.; Lazarev, A.

    2012-01-01

    The article discusses appropriate technologies for software implementation of the Virtual Accelerator. The Virtual Accelerator is considered as a set of services and tools enabling transparent execution of computational software for modeling beam dynamics in accelerators on distributed computing resources. Distributed storage and information processing facilities utilized by the Virtual Accelerator make use of the Service-Oriented Architecture (SOA) according to a cloud computing paradigm. Control system tool-kits (such as EPICS, TANGO), computing modules (including high-performance computing), realization of the GUI with existing frameworks and visualization of the data are discussed in the paper. The presented research consists of software analysis for realization of interaction between all levels of the Virtual Accelerator and some samples of middle-ware implementation. A set of the servers and clusters at St.-Petersburg State University form the infrastructure of the computing environment for Virtual Accelerator design. Usage of component-oriented technology for realization of Virtual Accelerator levels interaction is proposed. The article concludes with an overview and substantiation of a choice of technologies that will be used for design and implementation of the Virtual Accelerator. (authors)

  7. Designing Photonic Crystal Devices for Accelerators

    CERN Document Server

    Werner, Gregory

    2005-01-01

    Photonic crystals (periodic dielectric structures with a lattice constant on the order of the wavelength of light) can have a wide range of properties. For instance, photonic crystals can be designed to be completely reflective within a certain bandwidth, thereby becoming a replacement for metal in accelerator structures such as waveguides and cavities. To see whether photonic crystals might find application in accelerators, and to design potential accelerator structures, we will need reliable computer simulations to predict fields and frequencies and other properties of photonic crystal structures. We propose to build photonic crystal structures in the microwave regime and test the validity of computer simulation against experiment. We can then explore more complex issues such as coupling to photonic crystal structures, higher-order mode rejection, and tunable photonic crystals.

  8. Designing reliability into accelerators

    International Nuclear Information System (INIS)

    Hutton, A.

    1992-08-01

    For the next generation of high performance, high average luminosity colliders, the ''factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis

  9. Photonic Crystal Laser-Driven Accelerator Structures

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, Benjamin M

    2007-08-22

    Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

  10. Resonant coupling applied to superconducting accelerator structures

    International Nuclear Information System (INIS)

    Potter, James M.; Krawczyk, Frank L.

    2013-01-01

    The concept of resonant coupling and the benefits that accrue from its application is well known in the world of room temperature coupled cavity linacs. Design studies show that it can be applied successfully between sections of conventional elliptical superconducting coupled cavity accelerator structures and internally to structures with spoked cavity resonators. The coupling mechanisms can be designed without creating problems with high field regions or multipactoring. The application of resonant coupling to superconducting accelerators eliminates the need for complex cryogenic mechanical tuners and reduces the time needed to bring a superconducting accelerator into operation.

  11. Two-dimensional photonic crystal accelerator structures

    Directory of Open Access Journals (Sweden)

    Benjamin M. Cowan

    2003-10-01

    Full Text Available Photonic crystals provide a method of confining a synchronous speed-of-light mode in an all-dielectric structure, likely a necessary feature in any optical accelerator. We explore computationally a class of photonic crystal structures with translational symmetry in a direction transverse to the electron beam. We demonstrate synchronous waveguide modes and discuss relevant parameters of such modes. We then explore how accelerator parameters vary as the geometry of the structure is changed and consider trade-offs inherent in the design of an accelerator of this type.

  12. Design of an accelerated test to determine the attack of the sulphates on concrete structures, and the suggest alternative to design a container

    International Nuclear Information System (INIS)

    Malanca, Rodrigo Sebastian

    2003-01-01

    This work at demonstrating one of the accelerated tests in the frame of the Norm ASTM E-632-82, in order to evaluate the life of service for Reinforced Concrete Structures with High Performance.These will be used as barriers of engineering in containers for Radioactive Wastes.The results of the evaluation are necessary for the probabilistic and deterministic analysis, which are required to obtain licentiate for the emplacement and construction of this type of installations.Since concrete is the principal material used in this type of containers, its properties, in particular, its durability must be evaluated taking into accounts both, intrinsic factors and the extrinsic factors.Within the intrinsic factors we can mention your formulation, including design of armors of steel, production, treated and structural design.As extrinsic factors, weather and environmental, soil characteristic and service operation must be considered.It is important to emphasize that within the criteria used in the conceptual design of these types of repositories, the structures that act of barrier must not alter their insulation properties during all the period of service, which may be several hundreds of years.Although it is not possible to guarantee that repository's performance will not be altered throughout its time of service, the fact to obtain results of accelerated tests and the long term, it will enable us to estimate the durability of such structures, across the support of mathematical suitable models.The different stages which should be taken into account for the development of the evaluation tests, determining the relevant parameters to be considered in them and results obtained so far, are showing in this work

  13. Project X: Accelerator Reference Design

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Stephen D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-06-20

    applications of muon spin rotation techniques provide sensitive probes of the magnetic structure of materials. Goal: Provide MW-class proton beams at 1 GeV, coupled with novel targets required to support a broad range of materials science and energy applications. Platform for Evolution to Future Frontier Facilities: A high-intensity proton source will strengthen and modernize the Fermilab injector complex, providing a robust platform upon which to build future frontier facilities. The Neutrino Factory and Muon Collider are examples that would provide world-leading capabilities at the Intensity and Energy Frontiers for many decades to come. Goal: Provide a straightforward upgrade path for a 4 MW, low-duty-factor source of protons at energies between 5 and 15 GeV. These four elements are expected to form the basis of the Mission Need statement required for the Department of Energy (DOE) Critical Decision 0 (CD-0), and represent the fundamental design criteria for Project X. The following chapters present the Reference Design for the Project X accelerator facility. The Reference Design is based on a continuous wave (CW) superconducting (SC) linac providing up to 1 and 3 MW of beam power at 1 and 3 GeV respectively. A pulsed linac provides acceleration of roughly 4% of the beam delivered from the CW linac to the 8 GeV injection energy of the existing Recycler/Main Injector complex. Upgrades to the Recycler and Main Injector support a factor of three increase, beyond current capabilities, in proton beam power at 60 to 120 GeV. The Reference Design represents a facility that will be unique in the world with unmatched capabilities for the delivery of very high beam power, with flexible beam formats, to multiple users at multiple energies. The utilization of linacs within the Project X facility enables capabilities beyond what is achievable with circular accelerators. It is anticipated that the final configuration and operating parameters of the complex will be further refined through

  14. Injector Design for Advanced Accelerators

    Science.gov (United States)

    Henestroza, Enrique; Faltens, A.

    1996-11-01

    Accelerator designs intended to provide acceleration at a much lower cost per Joule than the ILSE or ELISE designs are under study. For these designs, which typically have many beams, an injector of significantly lower cost is needed. A goal, which from our design appears to be achievable, is to reduce the transverse dimension to half that of the 2 MeV, 800 mA ILSE injector(E. Henestroza, ``Injectors for Heavy Ion Fusion", Proc. of the 11th International Wkshp. on Laser Interaction and Related Plasma Phenomena, 1993.) while generating about the same current. A single channel of a lower cost injector includes an 800 kV column, accelerating a 700 mA beam extracted from a potassium source of 4 cm radius by a 120 kV electrode. The beam passes into a superconducting 7 T solenoid of 15 cm aperture and 15 cm length. This high-field solenoid provides the focusing needed for a small beam without increasing the electric field gradient. The injector and its matching section, also designed, fit within a 12 cm radius, which is small enough to allow construction of attractive multi-beam injectors. We will present solutions for the generation and transport of 700 mA potassium beams of up to 1.6 MeV within the same transverse constraint.

  15. CLIC Drive Beam Accelerating Structures

    CERN Document Server

    Wegner, Rolf

    2012-01-01

    Travelling structures for accelerating the high-current (4.2 A) CLIC Drive Beam to an energy of 2.37 GeV are presented. The structures are optimised for efficiency (full beam loading operation) and a desired filling time. Higher order modes are studied and are reduced by detuning along the structure and by damping with silicon carbide loads.

  16. Wakefield monitor development for CLIC accelerating structure

    CERN Document Server

    Peauger, F; Girardot, P; Andersson, A; Riddone, G; Samoshkin, A; Solodko, A; Zennaro, R; Ruber, R

    2010-01-01

    Abstract To achieve high luminosity in CLIC, the accelerating structures must be aligned to an accuracy of 5 μm with respect to the beam trajectory. Position detectors called Wakefield Monitors (WFM) are integrated to the structure for a beam based alignment. This paper describes the requirements of such monitors. Detailed RF design and electromagnetic simulations of the WFM itself are presented. In particular, time domain computations are performed and an evaluation of the resolution is done for two higher order modes at 18 and 24 GHz. The mechanical design of a prototype accelerating structure with WFM is also presented as well as the fabrication status of three complete structures. The objective is to implement two of them in CTF3 at CERN for a feasibility demonstration with beam and high power rf.

  17. Progress Toward NLC/GLC Prototype Accelerator Structures

    International Nuclear Information System (INIS)

    Wang, J

    2004-01-01

    The accelerator structure groups for NLC (Next Linear Collider) and GLC (Global Linear Colliders) have successfully collaborated on the research and development of a major series of advanced accelerator structures based on room-temperature technology at X-band frequency. The progress in design, simulation, microwave measurement and high gradient tests are summarized in this paper. The recent effort in design and fabrication of the accelerator structure prototype for the main linac is presented in detail including HOM (High Order Mode) suppression and design of HOM couplers and fundamental mode couplers, optimized accelerator cavities as well as plans for future structures

  18. COMPASS Accelerator Design Technical Overview

    Energy Technology Data Exchange (ETDEWEB)

    Nanni, Emilio; Dolgashev, Valery; Tantawi, Sami; Neilson, Jeff; /SLAC

    2016-03-14

    This report is a survey of technical options for generating a MeV-class accelerator for space based science applications. The survey was performed focusing on the primary technical requirements of the accelerator in the context of a satellite environment with its unique challenges of limited electrical power (PE), thermal isolation, dimensions, payload requirement and electrical isolation.

  19. Multi-Mode Cavity Accelerator Structure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yong [Yale Univ., New Haven, CT (United States); Hirshfield, Jay Leonard [Omega-P R& D, Inc., New Haven, CT (United States)

    2016-11-10

    This project aimed to develop a prototype for a novel accelerator structure comprising coupled cavities that are tuned to support modes with harmonically-related eigenfrequencies, with the goal of reaching an acceleration gradient >200 MeV/m and a breakdown rate <10-7/pulse/meter. Phase I involved computations, design, and preliminary engineering of a prototype multi-harmonic cavity accelerator structure; plus tests of a bimodal cavity. A computational procedure was used to design an optimized profile for a bimodal cavity with high shunt impedance and low surface fields to maximize the reduction in temperature rise ΔT. This cavity supports the TM010 mode and its 2nd harmonic TM011 mode. Its fundamental frequency is at 12 GHz, to benchmark against the empirical criteria proposed within the worldwide High Gradient collaboration for X-band copper structures; namely, a surface electric field Esurmax< 260 MV/m and pulsed surface heating ΔTmax< 56 °K. With optimized geometry, amplitude and relative phase of the two modes, reductions are found in surface pulsed heating, modified Poynting vector, and total RF power—as compared with operation at the same acceleration gradient using only the fundamental mode.

  20. Parametric approach to linear induction accelerator design

    International Nuclear Information System (INIS)

    Bresie, D.A.; Andrews, J.A.; Ingram, S.W.

    1991-01-01

    Past work on the design of linear induction accelerators has centered on the development of computer codes to analyze accelerator designs, using the current filament method. While these filament models are a very valuable tool for evaluating the performance of an induction launcher design, they provide little insight into the selection of dimensions, materials, and operation points for accelerators with interesting performance. Described in this paper is a parametric approach to defining effective accelerator designs. This method uses a computer optimization routine to iteratively seek out effective designs. The optimization routine is forced to search within a parameter space restricted to interesting and realistic parameters such as size, weight, voltage, and temperature rises. A filament model is used as the filter for the optimizer. Several linear induction accelerators have been designed using this method. The accelerators designed all used a switched capacitor power supply. While the run time of this code on The University of Texas' CRAY XMP-24 computer is moderately long, the resulting designs have good predicted performance. With realistic power supplies and materials, accelerator efficiencies in the 20 to 40% range were easily obtained. This paper describes the effect of armature diameter, length-to-diameter ratio, and weight, as well as other parameters, on the optimum accelerator design

  1. Modeling accelerator structures and RF components

    International Nuclear Information System (INIS)

    Ko, K., Ng, C.K.; Herrmannsfeldt, W.B.

    1993-03-01

    Computer modeling has become an integral part of the design and analysis of accelerator structures RF components. Sophisticated 3D codes, powerful workstations and timely theory support all contributed to this development. We will describe our modeling experience with these resources and discuss their impact on ongoing work at SLAC. Specific examples from R ampersand D on a future linear collide and a proposed e + e - storage ring will be included

  2. Dynamics and acceleration in linear structures

    International Nuclear Information System (INIS)

    Le Duff, J.

    1985-06-01

    Basic methods of linear acceleration are reviewed. Both cases of non relativistic and ultra relativistic particles are considered. Induction linac, radiofrequency quadrupole are mentioned. Fundamental parameters of accelerating structures are recalled; they are transit time factor, shunt impedance, quality factor and stored energy, phase velocity and group velocity, filling time, space harmonics in loaded waveguides. Energy gain in linear accelerating structures is considered through standing wave structures and travelling wave structures. Then particle dynamics in linear accelerators is studied: longitudinal motion, transverse motion and dynamics in RFQ

  3. Required performance to the concrete structure of the accelerator facilities

    International Nuclear Information System (INIS)

    Irie, Masaaki; Yoshioka, Masakazu; Miyahara, Masanobu

    2006-01-01

    As for the accelerator facility, there is many a thing which is constructed as underground concrete structure from viewpoint such as cover of radiation and stability of the structure. Required performance to the concrete structure of the accelerator facility is the same as the general social infrastructure, but it has been possessed the feature where target performance differs largely. As for the body sentence, expressing the difference of the performance which is required from the concrete structure of the social infrastructure and the accelerator facility, construction management of the concrete structure which it plans from order of the accelerator engineering works facility, reaches to the design, supervision and operation it is something which expresses the method of thinking. In addition, in the future of material structural analysis of the concrete which uses the neutron accelerator concerning view it showed. (author)

  4. Phase gradients in acceleration structures

    International Nuclear Information System (INIS)

    Decker, F.J.; Jobe, R.K.

    1990-05-01

    In linear accelerators with two or more bunches the beam loading of one bunch will influence the energy and energy spread the following bunches. This can be corrected by quickly changing the phase of a travelling wave structure, so that each bunch recieves a slightly different net phase. At the SLAC Linear Collider (SLC) three bunches, two (e + ,e - ) for the high energy collisions and one (e - -scavenger) for producing positrons should sit at different phases, due to their different tasks. The two e - -bunches are extracted from the damping ring at the same cycle time about 60 ns apart. Fast phase switching of the RF to the bunch length compressor in the Ring-To-Linac (RTL) section can produce the necessary advance of the scavenger bunch (about 6 degree in phase). This allows a low energy spread of this third bunch at the e + -production region at 2/3 of the linac length, while the other bunches are not influenced. The principles and possible other applications of this fast phase switching as using it for multi-bunches, as well as the experimental layout for the actual RTL compressor are presented

  5. A New Damped and Tapered Accelerating Structure for CLIC

    CERN Document Server

    Raguin, J Y; Syratchev, I V; Wilson, Ian H; Wuensch, Walter

    2002-01-01

    The main performance limits when designing accelerating structures for the Compact Linear Collider (CLIC) for an average accelerating gradient above 100 MV/m are electrical breakdown and material fatigue caused by pulsed surface heating. In addition, for stable beam operation, the structures should have low short-range transverse wakefields and much-reduced transverse and longitudinal long-range wakefields. Two damped and tapered accelerating structures have been designed. The first has an accelerating gradient of 112 MV/m with the surface electrical field limited to 300 MV/m and the maximum temperature increase limited to 100°C. The second, with an accelerating gradient of 150 MV/m, has a peak surface electrical field of 392 MV/m and a maximum temperature increase of 167°C. Innovations to the cell and damping waveguide geometry and to the tapering of the structures are presented, and possible further improvements are proposed.

  6. Coupler Studies for CLIC Accelerating Structures

    CERN Document Server

    Döbert, Steffen; Syratchev, I V; Wuensch, Walter

    2002-01-01

    Due to high input power required to feed the accelerating structures of the Compact Linear Collider, the RF input and output couplers are critical components. Four different types of double-feed cavity-based couplers as well as a mode launcher have been investigated. Three of them are based on magnetic coupling between the input waveguides and the cavity while the fourth is based on electric coupling. The different designs have been optimized to minimize surface electric field as well as field asymmetry and to reduce the pulse surface heating and the sensitivity to mechanical errors.

  7. The deuteron accelerator preliminary design for BISOL

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.X., E-mail: sxpeng@pku.edu.cn; Zhu, F.; Wang, Z.; Gao, Y.; Guo, Z.Y.

    2016-06-01

    BISOL, which was named as Beijing-ISOL before (Cui et al., 2013), is the abbreviation of Beijing Isotope-Separation-On-Line neutron beam facility. It is proposed jointly by Peking University (PKU) and China Institute of Atomic Energy (CIAE) for basic science study and application. It is a double driven facility that can be driven by a reactor or a deuteron accelerator. The deuteron driver accelerator should accelerate the deuteron beam up to 40 MeV with maximum beam current of 10 mA. Proton beams up to 33 MeV and He{sup 2+} beams up to 81.2 MeV can also be accelerated in this accelerator. The accelerator can be operated on either CW (continuous waveform) or pulsed mode, and the ion energy can be adjusted in a wide range. The accelerator will also allow independent operation of the RIB (Radioactive Ion Beams) system. It will be mainly charged by PKU group. Details of the deuteron accelerator preliminary design for BISOL will be given in this paper.

  8. CEBAF [Continuous Electron Beam Accelerator Facility] design report

    International Nuclear Information System (INIS)

    1986-05-01

    This book describes the conceptual design of, and the planning for, the Continuous Electron Beam Accelerator Facility (CEBAF), which will be a high-intensity, continuous-wave electron linear accelerator (linac) for nuclear physics. Its principal scientific goal is to understand the quark structure, behavior, and clustering of individual nucleons in the nuclear medium, and simultaneously to understand the forces governing this behavior. The linac will consist of 1 GeV of accelerating structure, split into two antiparallel 0.5-GeV segments. The segments will be connected by a beam transport system to circulate the electron beams from one segment to the other for up to four complete passes of acceleration. The maximum beam energy will be 4 GeV at a design current of 200 microamperes. The accelerator complex will also include systems to extract three continuous beams from the linac and to deliver them to three experimental halls equipped with detectors and instrumentation for nuclear physics research. The accelerating structure will be kept superconducting within insulated cryostats filled with liquid helium produced at a central helium refrigerator and distributed to the cryostats via insulated transfer lines. An injector, instrumentation and controls for the accelerator, radio-frequency power systems, and several support facilities will also be provided. A cost estimate based on the Work Breakdown Structure has been completed. Assuming a five-year construction schedule starting early in FY 1987, the total estimated cost is $236 million (actual year dollars), including contingency

  9. Mechanical Design of Superconducting Accelerator Magnets

    CERN Document Server

    Toral, Fernando

    2014-07-17

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques.

  10. Nuclear data for designing the IFMIF accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The objective of the International Fusion Materials Irradiation Facility (IFMIF) and the design concept of the IFMIF accelerator system are described. The status of the nuclear data, especially for the deuteron-induced reactions, to qualify the system design is reviewed. The requests for the nuclear data compilation and/or evaluation are summarized. (author)

  11. Preliminary design of a 10 MV ion accelerator

    International Nuclear Information System (INIS)

    Fessenden, T.J.; Celata, C.M.; Faltens, A.

    1986-06-01

    At the low energy end of an induction linac HIF driver the beam current is limited by our ability to control space charge by a focusing system. As a consequence, HIF induction accelerator designs feature simultaneous acceleration of many beams in parallel within a single accelerator structure. As the speed of the beams increase, the focusing system changes from electrostatic to magnetic quadrupoles with a corresponding increase in the maximum allowable current. At that point the beams are merged thereby decreasing the cost of the subsequent accelerator structure. The LBL group is developing an experiment to study the physics of merging and of focusing ion beams. In the design, parallel beams of ions (C + , Al + , or Al ++ ) are accelerated to several MV and merged transversely. The merged beams are then further accelerated and the growth in transverse and longitudinal emittance is determined for comparison with theory. The apparatus will then be used to study the problems associated with focusing ion beams to a small spot. Details of the accelerator design and considerations of the physics of combining beams are presented

  12. Design of an electromagnetic accelerator for turbulent hydrodynamic mix studies

    International Nuclear Information System (INIS)

    Susoeff, A.R.; Hawke, R.S.; Morrison, J.J.; Dimonte, G.; Remington, B.A.

    1994-03-01

    An electromagnetic accelerator in the form of a linear electric motor (LEM) has been designed to achieve controlled acceleration profiles of a carriage containing hydrodynamically unstable fluids for the investigation of the development of turbulent mix. Key features of the design include: (1) independent control of acceleration, deceleration and augmentation currents to provide a variety of acceleration-time profiles, (2) a robust support structure to minimized deflection and dampen vibration which could create artifacts in the data interfering with the intended study and (3) a compliant, non-arcing solid armature allowing optimum electrical contact. Electromagnetic modeling codes were used to optimize the rail and augmentation coil positions within the support structure framework. Design of the driving armature and the dynamic electromagnetic braking system is based on results of contemporary studies for non-arcing sliding contact of solid armatures. A 0.6MJ electrolytic capacitor bank is used for energy storage to drive the LEM. This report will discuss a LEM and armature design which will accelerate masses of up to 3kg to a maximum of about 3000g o , where g o is acceleration due to gravity

  13. Computing tools for accelerator design calculations

    International Nuclear Information System (INIS)

    Fischler, M.; Nash, T.

    1984-01-01

    This note is intended as a brief, summary guide for accelerator designers to the new generation of commercial and special processors that allow great increases in computing cost effectiveness. New thinking is required to take best advantage of these computing opportunities, in particular, when moving from analytical approaches to tracking simulations. In this paper, we outline the relevant considerations

  14. Object-oriented accelerator design with HPF

    International Nuclear Information System (INIS)

    Ji Qiang; Ryne, R.D.; Habib, S.

    1998-01-01

    In this paper, object-oriented design is applied to codes for beam dynamics simulations in accelerators using High Performance Fortran (HPF). This results in good maintainability, reusability, and extensibility of software, combined with the ease of parallel programming provided by HPF

  15. Performance testing of the LUEhR-40M structure with an accelerated beam

    International Nuclear Information System (INIS)

    Vakhrushin, Yu.P.; Voznyuk, V.N.; Nikolaev, V.M.; Ryabtsov, A.V.; Smirnov, V.L.; Terent'ev, V.V.

    1988-01-01

    The results of experimental investigation of the prototype of the accelerating structure of the therapeutic linear accelerator of the LUEhR-40M model with an accelerating beam are presented. The accelerating structure is the standing wave biperiodic structure with inner coupling cells of 1.6 m length. The design energy of accelerated electrons equalling 20 MeV (during single electron beam passage through an accelerating structure) is obtained. 60 % of accelerated particles are accumulated in the energy interval of (20±1) MeV at 20 mA pulse current and at 3.6 MW SHF-power at the structure input

  16. Accelerator design of the KHI FEL device

    CERN Document Server

    Yokoyama, M; Nakayama, A; Nomaru, K; Kawai, M

    1999-01-01

    Kawasaki Heavy Industries, Ltd. (KHI) has designed a compact free electron laser device that can provide a powerful and tunable (5-16 mu m) light source. The FEL device consists of a 32 MeV accelerator, a beam transport system with two 25-degree bending magnets, an undulator of 40 periods and 32 mm period length, and a cavity mirror system. Using some computer codes to optimize the beam optics of the accelerator could provide a high-quality beam for the FEL.

  17. Design of straus-r accelerator

    CERN Document Server

    Gordeev, V S; Laptev, D V

    2001-01-01

    The paper presents a design of the direct-operation high-current electron accelerator STRAUS-R that is a modification of STRAUS-2 now in force. The accelerator is aimed at generating single Bremsstrahlung pulses in the mode of electron beam focusing on the target. According to the calculations it should provide for getting the dose (Si) of 0.2 / 0.25 Gy at a 1 meter distance from the target,the electron beam current being equal to 50/60 kA,boundary energy of electrons - to 2.7 / 3.0 MeV, Bremsstrahlung pulse duration - to <= 50 ns and beam diameter on the target-to <= 5 mm.The description and results of numerical simulation of physics processes taking place in the accelerator are given.

  18. Calculation of coupling factor for the heterogeneous accelerating structure

    International Nuclear Information System (INIS)

    Bian Xiaohao; Chen Huaibi; Zheng Shuxin

    2006-01-01

    The converging part of electron accelerator is designed to converge the phase of injecting electrons, improving the beam quality of the accelerator. It is very crucial to calculate the coupling factor between cavities and to design the geometry structure of the coupling irises. By the E module of code MAFIA, the authors calculate the frequency of every single resonant cavity and the two eigenfrequencies of two-cavitiy line. Then we get the coupling factor between the two cavities. This method can be used to design the geometry structure of the coupling isises between every two cavities. Compared to experiment, the results of the method is very accurate. (authors)

  19. ILC Reference Design Report Volume 3 - Accelerator

    CERN Document Server

    Phinney, Nan; Walker, Nicholas J.; Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; Amann, John; Amirikas, Ramila; An, Qi; Anami, Shozo; Ananthanarayan, B.; Anderson, Terry; Andricek, Ladislav; Anduze, Marc; Anerella, Michael; Anfimov, Nikolai; Angal-Kalinin, Deepa; Antipov, Sergei; Antoine, Claire; Aoki, Mayumi; Aoza, Atsushi; Aplin, Steve; Appleby, Rob; Arai, Yasuo; Araki, Sakae; Arkan, Tug; Arnold, Ned; Arnold, Ray; Arnowitt, Richard; Artru, Xavier; Arya, Kunal; Aryshev, Alexander; Asakawa, Eri; Asiri, Fred; Asner, David; Atac, Muzaffer; Atoian, Grigor; Attié, David; Augustin, Jean-Eudes; Augustine, David B.; Ayres, Bradley; Aziz, Tariq; Baars, Derek; Badaud, Frederique; Baddams, Nigel; Bagger, Jonathan; Bai, Sha; Bailey, David; Bailey, Ian R.; Baker, David; Balalykin, Nikolai I.; Balbuena, Juan Pablo; Baldy, Jean-Luc; Ball, Markus; Ball, Maurice; Ballestrero, Alessandro; Ballin, Jamie; Baltay, Charles; Bambade, Philip; Ban, Syuichi; Band, Henry; Bane, Karl; Banerjee, Bakul; Barbanotti, Serena; Barbareschi, Daniele; Barbaro-Galtieri, Angela; Barber, Desmond P.; Barbi, Mauricio; Bardin, Dmitri Y.; Barish, Barry; Barklow, Timothy L.; Barlow, Roger; Barnes, Virgil E.; Barone, Maura; Bartels, Christoph; Bartsch, Valeria; Basu, Rahul; Battaglia, Marco; Batygin, Yuri; Baudot, Jerome; Baur, Ulrich; Elwyn Baynham, D.; Beard, Carl; Bebek, Chris; Bechtle, Philip; Becker, Ulrich J.; Bedeschi, Franco; Bedjidian, Marc; Behera, Prafulla; Behnke, Ties; Bellantoni, Leo; Bellerive, Alain; Bellomo, Paul; Bentson, Lynn D.; Benyamna, Mustapha; Bergauer, Thomas; Berger, Edmond; Bergholz, Matthias; Beri, Suman; Berndt, Martin; Bernreuther, Werner; Bertolini, Alessandro; Besancon, Marc; Besson, Auguste; Beteille, Andre; Bettoni, Simona; Beyer, Michael; Bhandari, R.K.; Bharadwaj, Vinod; Bhatnagar, Vipin; Bhattacharya, Satyaki; Bhattacharyya, Gautam; Bhattacherjee, Biplob; Bhuyan, Ruchika; Bi, Xiao-Jun; Biagini, Marica; Bialowons, Wilhelm; Biebel, Otmar; Bieler, Thomas; Bierwagen, John; Birch, Alison; Bisset, Mike; Biswal, S.S.; Blackmore, Victoria; Blair, Grahame; Blanchard, Guillaume; Blazey, Gerald; Blue, Andrew; Blümlein, Johannes; Boffo, Christian; Bohn, Courtlandt; Boiko, V.I.; Boisvert, Veronique; Bondarchuk, Eduard N.; Boni, Roberto; Bonvicini, Giovanni; Boogert, Stewart; Boonekamp, Maarten; Boorman, Gary; Borras, Kerstin; Bortoletto, Daniela; Bosco, Alessio; Bosio, Carlo; Bosland, Pierre; Bosotti, Angelo; Boudry, Vincent; Boumediene, Djamel-Eddine; Bouquet, Bernard; Bourov, Serguei; Bowden, Gordon; Bower, Gary; Boyarski, Adam; Bozovic-Jelisavcic, Ivanka; Bozzi, Concezio; Brachmann, Axel; Bradshaw, Tom W.; Brandt, Andrew; Brasser, Hans Peter; Brau, Benjamin; Brau, James E.; Breidenbach, Martin; Bricker, Steve; Brient, Jean-Claude; Brock, Ian; Brodsky, Stanley; Brooksby, Craig; Broome, Timothy A.; Brown, David; Brown, David; Brownell, James H.; Bruchon, Mélanie; Brueck, Heiner; Brummitt, Amanda J.; Brun, Nicole; Buchholz, Peter; Budagov, Yulian A.; Bulgheroni, Antonio; Bulyak, Eugene; Bungau, Adriana; Bürger, Jochen; Burke, Dan; Burkhart, Craig; Burrows, Philip; Burt, Graeme; Burton, David; Büsser, Karsten; Butler, John; Butterworth, Jonathan; Buzulutskov, Alexei; Cabruja, Enric; Caccia, Massimo; Cai, Yunhai; Calcaterra, Alessandro; Caliier, Stephane; Camporesi, Tiziano; Cao, Jun-Jie; Cao, J.S.; Capatina, Ofelia; Cappellini, Chiara; Carcagno, Ruben; Carena, Marcela; Carloganu, Cristina; Carosi, Roberto; Stephen Carr, F.; Carrion, Francisco; Carter, Harry F.; Carter, John; Carwardine, John; Cassel, Richard; Cassell, Ronald; Cavallari, Giorgio; Cavallo, Emanuela; Cembranos, Jose A.R.; Chakraborty, Dhiman; Chandez, Frederic; Charles, Matthew; Chase, Brian; Chattopadhyay, Subhasis; Chauveau, Jacques; Chefdeville, Maximilien; Chehab, Robert; Chel, Stéphane; Chelkov, Georgy; Chen, Chiping; Chen, He Sheng; Chen, Huai Bi; Chen, Jia Er; Chen, Sen Yu; Chen, Shaomin; Chen, Shenjian; Chen, Xun; Chen, Yuan Bo; Cheng, Jian; Chevallier, M.; Chi, Yun Long; Chickering, William; Cho, Gi-Chol; Cho, Moo-Hyun; Choi, Jin-Hyuk; Choi, Jong Bum; Choi, Seong Youl; Choi, Young-Il; Choudhary, Brajesh; Choudhury, Debajyoti; Rai Choudhury, S.; Christian, David; Christian, Glenn; Christophe, Grojean; Chung, Jin-Hyuk; Church, Mike; Ciborowski, Jacek; Cihangir, Selcuk; Ciovati, Gianluigi; Clarke, Christine; Clarke, Don G.; Clarke, James A.; Clements, Elizabeth; Coca, Cornelia; Coe, Paul; Cogan, John; Colas, Paul; Collard, Caroline; Colledani, Claude; Combaret, Christophe; Comerma, Albert; Compton, Chris; Constance, Ben; Conway, John; Cook, Ed; Cooke, Peter; Cooper, William; Corcoran, Sean; Cornat, Rémi; Corner, Laura; Cortina Gil, Eduardo; Clay Corvin, W.; Cotta Ramusino, Angelo; Cowan, Ray; Crawford, Curtis; Cremaldi, Lucien M; Crittenden, James A.; Cussans, David; Cvach, Jaroslav; da Silva, Wilfrid; Dabiri Khah, Hamid; Dabrowski, Anne; Dabrowski, Wladyslaw; Dadoun, Olivier; Dai, Jian Ping; Dainton, John; Daly, Colin; Damerell, Chris; Danilov, Mikhail; Daniluk, Witold; Daram, Sarojini; Datta, Anindya; Dauncey, Paul; David, Jacques; Davier, Michel; Davies, Ken P.; Dawson, Sally; De Boer, Wim; De Curtis, Stefania; De Groot, Nicolo; de la Taille, Christophe; de Lira, Antonio; De Roeck, Albert; de Sangro, Riccardo; De Santis,Stefano; Deacon, Laurence; Deandrea, Aldo; Dehmelt, Klaus; Delagnes, Eric; Delahaye, Jean-Pierre; Delebecque, Pierre; Delerue, Nicholas; Delferriere, Olivier; Demarteau, Marcel; Deng, Zhi; Denisov, Yu.N.; Densham, Christopher J.; Desch, Klaus; Deshpande, Nilendra; Devanz, Guillaume; Devetak, Erik; Dexter, Amos; Di benedetto, Vito; Diéguez, Angel; Diener, Ralf; Dinh, Nguyen Dinh; Dixit, Madhu; Dixit, Sudhir; Djouadi, Abdelhak; Dolezal, Zdenek; Dollan, Ralph; Dong, Dong; Dong, Hai Yi; Dorfan, Jonathan; Dorokhov, Andrei; Doucas, George; Downing, Robert; Doyle, Eric; Doziere, Guy; Drago, Alessandro; Dragt, Alex; Drake, Gary; Drásal, Zbynek; Dreiner, Herbert; Drell, Persis; Driouichi, Chafik; Drozhdin, Alexandr; Drugakov, Vladimir; Du, Shuxian; Dugan, Gerald; Duginov, Viktor; Dulinski, Wojciech; Dulucq, Frederic; Dutta, Sukanta; Dwivedi, Jishnu; Dychkant, Alexandre; Dzahini, Daniel; Eckerlin, Guenter; Edwards, Helen; Ehrenfeld, Wolfgang; Ehrlichman, Michael; Ehrlichmann, Heiko; Eigen, Gerald; Elagin, Andrey; Elementi, Luciano; Eliasson, Peder; Ellis, John; Ellwood, George; Elsen, Eckhard; Emery, Louis; Enami, Kazuhiro; Endo, Kuninori; Enomoto, Atsushi; Eozénou, Fabien; Erbacher, Robin; Erickson, Roger; Oleg Eyser, K.; Fadeyev, Vitaliy; Fang, Shou Xian; Fant, Karen; Fasso, Alberto; Faucci Giannelli, Michele; Fehlberg, John; Feld, Lutz; Feng, Jonathan L.; Ferguson, John; Fernandez-Garcia, Marcos; Luis Fernandez-Hernando, J.; Fiala, Pavel; Fieguth, Ted; Finch, Alexander; Finocchiaro, Giuseppe; Fischer, Peter; Fisher, Peter; Eugene Fisk, H.; Fitton, Mike D.; Fleck, Ivor; Fleischer, Manfred; Fleury, Julien; Flood, Kevin; Foley, Mike; Ford, Richard; Fortin, Dominique; Foster, Brian; Fourches, Nicolas; Francis, Kurt; Frey, Ariane; Frey, Raymond; Friedsam, Horst; Frisch, Josef; Frishman, Anatoli; Fuerst, Joel; Fujii, Keisuke; Fujimoto, Junpei; Fukuda, Masafumi; Fukuda, Shigeki; Funahashi, Yoshisato; Funk, Warren; Furletova, Julia; Furukawa, Kazuro; Furuta, Fumio; Fusayasu, Takahiro; Fuster, Juan; Gadow, Karsten; Gaede, Frank; Gaglione, Renaud; Gai, Wei; Gajewski, Jan; Galik, Richard; Galkin, Alexei; Galkin, Valery; Gallin-Martel, Laurent; Gannaway, Fred; Gao, Jian She; Gao, Jie; Gao, Yuanning; Garbincius, Peter; Garcia-Tabares, Luis; Garren, Lynn; Garrido, Luís; Garutti, Erika; Garvey, Terry; Garwin, Edward; Gascón, David; Gastal, Martin; Gatto, Corrado; Gatto, Raoul; Gay, Pascal; Ge, Lixin; Ge, Ming Qi; Ge, Rui; Geiser, Achim; Gellrich, Andreas; Genat, Jean-Francois; Geng, Zhe Qiao; Gentile, Simonetta; Gerbick, Scot; Gerig, Rod; Ghosh, Dilip Kumar; Ghosh, Kirtiman; Gibbons, Lawrence; Giganon, Arnaud; Gillespie, Allan; Gillman, Tony; Ginzburg, Ilya; Giomataris, Ioannis; Giunta, Michele; Gladkikh, Peter; Gluza, Janusz; Godbole, Rohini; Godfrey, Stephen; Goldhaber, Gerson; Goldstein, Joel; Gollin, George D.; Gonzalez-Sanchez, Francisco Javier; Goodrick, Maurice; Gornushkin, Yuri; Gostkin, Mikhail; Gottschalk, Erik; Goudket, Philippe; Gough Eschrich, Ivo; Gournaris, Filimon; Graciani, Ricardo; Graf, Norman; Grah, Christian; Grancagnolo, Francesco; Grandjean, Damien; Grannis, Paul; Grassellino, Anna; Graugés, Eugeni; Gray, Stephen; Green, Michael; Greenhalgh, Justin; Greenshaw, Timothy; Grefe, Christian; Gregor, Ingrid-Maria; Grenier, Gerald; Grimes, Mark; Grimm, Terry; Gris, Philippe; Grivaz, Jean-Francois; Groll, Marius; Gronberg, Jeffrey; Grondin, Denis; Groom, Donald; Gross, Eilam; Grunewald, Martin; Grupen, Claus; Grzelak, Grzegorz; Gu, Jun; Gu, Yun-Ting; Guchait, Monoranjan; Guiducci, Susanna; Guler, Ali Murat; Guler, Hayg; Gulmez, Erhan; Gunion, John; Guo, Zhi Yu; Gurtu, Atul; Ha, Huy Bang; Haas, Tobias; Haase, Andy; Haba, Naoyuki; Haber, Howard; Haensel, Stephan; Hagge, Lars; Hagura, Hiroyuki; Hajdu, Csaba; Haller, Gunther; Haller, Johannes; Hallermann, Lea; Halyo, Valerie; Hamaguchi, Koichi; Hammond, Larry; Han, Liang; Han, Tao; Hand, Louis; Handu, Virender K.; Hano, Hitoshi; Hansen, Christian; Hansen, Jørn Dines; Hansen, Jorgen Beck; Hara, Kazufumi; Harder, Kristian; Hartin, Anthony; Hartung, Walter; Hast, Carsten; Hauptman, John; Hauschild, Michael; Hauviller, Claude; Havranek, Miroslav; Hawkes, Chris; Hawkings, Richard; Hayano, Hitoshi; Hazumi, Masashi; He, An; He, Hong Jian; Hearty, Christopher; Heath, Helen; Hebbeker, Thomas; Hedberg, Vincent; Hedin, David; Heifets, Samuel; Heinemeyer, Sven; Heini, Sebastien; Helebrant, Christian; Helms, Richard; Heltsley, Brian; Henrot-Versille, Sophie; Henschel, Hans; Hensel, Carsten; Hermel, Richard; Herms, Atilà; Herten, Gregor; Hesselbach, Stefan; Heuer, Rolf-Dieter; Heusch, Clemens A.; Hewett, Joanne; Higashi, Norio; Higashi, Takatoshi; Higashi, Yasuo; Higo, Toshiyasu; Hildreth, Michael D.; Hiller, Karlheinz; Hillert, Sonja; Hillier, Stephen James; Himel, Thomas; Himmi, Abdelkader; Hinchliffe, Ian; Hioki, Zenro; Hirano, Koichiro; Hirose, Tachishige; Hisamatsu, Hiromi; Hisano, Junji; Hlaing, Chit Thu; Hock, Kai Meng; Hoeferkamp, Martin; Hohlfeld, Mark; Honda, Yousuke; Hong, Juho; Hong, Tae Min; Honma, Hiroyuki; Horii, Yasuyuki; Horvath, Dezso; Hosoyama, Kenji; Hostachy, Jean-Yves; Hou, Mi; Hou, Wei-Shu; Howell, David; Hronek, Maxine; Hsiung, Yee B.; Hu, Bo; Hu, Tao; Huang, Jung-Yun; Huang, Tong Ming; Huang, Wen Hui; Huedem, Emil; Huggard, Peter; Hugonie, Cyril; Hu-Guo, Christine; Huitu, Katri; Hwang, Youngseok; Idzik, Marek; Ignatenko, Alexandr; Ignatov, Fedor; Ikeda, Hirokazu; Ikematsu, Katsumasa; Ilicheva, Tatiana; Imbault, Didier; Imhof, Andreas; Incagli, Marco; Ingbir, Ronen; Inoue, Hitoshi; Inoue, Youichi; Introzzi, Gianluca; Ioakeimidi, Katerina; Ishihara, Satoshi; Ishikawa, Akimasa; Ishikawa, Tadashi; Issakov, Vladimir; Ito, Kazutoshi; Ivanov, V.V.; Ivanov, Valentin; Ivanyushenkov, Yury; Iwasaki, Masako; Iwashita, Yoshihisa; Jackson, David; Jackson, Frank; Jacobsen, Bob; Jaganathan, Ramaswamy; Jamison, Steven; Janssen, Matthias Enno; Jaramillo-Echeverria, Richard; Jaros, John; Jauffret, Clement; Jawale, Suresh B.; Jeans, Daniel; Jedziniak, Ron; Jeffery, Ben; Jehanno, Didier; Jenner, Leo J.; Jensen, Chris; Jensen, David R.; Jiang, Hairong; Jiang, Xiao Ming; Jimbo, Masato; Jin, Shan; Keith Jobe, R.; Johnson, Anthony; Johnson, Erik; Johnson, Matt; Johnston, Michael; Joireman, Paul; Jokic, Stevan; Jones, James; Jones, Roger M.; Jongewaard, Erik; Jönsson, Leif; Joshi, Gopal; Joshi, Satish C.; Jung, Jin-Young; Junk, Thomas; Juste, Aurelio; Kado, Marumi; Kadyk, John; Käfer, Daniela; Kako, Eiji; Kalavase, Puneeth; Kalinin, Alexander; Kalinowski, Jan; Kamitani, Takuya; Kamiya, Yoshio; Kamiya, Yukihide; Kamoshita, Jun-ichi; Kananov, Sergey; Kanaya, Kazuyuki; Kanazawa, Ken-ichi; Kanemura, Shinya; Kang, Heung-Sik; Kang, Wen; Kanjial, D.; Kapusta, Frédéric; Karataev, Pavel; Karchin, Paul E.; Karlen, Dean; Karyotakis, Yannis; Kashikhin, Vladimir; Kashiwagi, Shigeru; Kasley, Paul; Katagiri, Hiroaki; Kato, Takashi; Kato, Yukihiro; Katzy, Judith; Kaukher, Alexander; Kaur, Manjit; Kawagoe, Kiyotomo; Kawamura, Hiroyuki; Kazakov, Sergei; Kekelidze, V.D.; Keller, Lewis; Kelley, Michael; Kelly, Marc; Kelly, Michael; Kennedy, Kurt; Kephart, Robert; Keung, Justin; Khainovski, Oleg; Khan, Sameen Ahmed; Khare, Prashant; Khovansky, Nikolai; Kiesling, Christian; Kikuchi, Mitsuo; Kilian, Wolfgang; Killenberg, Martin; Kim, Donghee; Kim, Eun San; Kim, Eun-Joo; Kim, Guinyun; Kim, Hongjoo; Kim, Hyoungsuk; Kim, Hyun-Chui; Kim, Jonghoon; Kim, Kwang-Je; Kim, Kyung Sook; Kim, Peter; Kim, Seunghwan; Kim, Shin-Hong; Kim, Sun Kee; Kim, Tae Jeong; Kim, Youngim; Kim, Young-Kee; Kimmitt, Maurice; Kirby, Robert; Kircher, François; Kisielewska, Danuta; Kittel, Olaf; Klanner, Robert; Klebaner, Arkadiy L.; Kleinwort, Claus; Klimkovich, Tatsiana; Klinkby, Esben; Kluth, Stefan; Knecht, Marc; Kneisel, Peter; Ko, In Soo; Ko, Kwok; Kobayashi, Makoto; Kobayashi, Nobuko; Kobel, Michael; Koch, Manuel; Kodys, Peter; Koetz, Uli; Kohrs, Robert; Kojima, Yuuji; Kolanoski, Hermann; Kolodziej, Karol; Kolomensky, Yury G.; Komamiya, Sachio; Kong, Xiang Cheng; Konigsberg, Jacobo; Korbel, Volker; Koscielniak, Shane; Kostromin, Sergey; Kowalewski, Robert; Kraml, Sabine; Krammer, Manfred; Krasnykh, Anatoly; Krautscheid, Thorsten; Krawczyk, Maria; James Krebs, H.; Krempetz, Kurt; Kribs, Graham; Krishnagopal, Srinivas; Kriske, Richard; Kronfeld, Andreas; Kroseberg, Jürgen; Kruchonak, Uladzimir; Kruecker, Dirk; Krüger, Hans; Krumpa, Nicholas A.; Krumshtein, Zinovii; Kuang, Yu Ping; Kubo, Kiyoshi; Kuchler, Vic; Kudoh, Noboru; Kulis, Szymon; Kumada, Masayuki; Kumar, Abhay; Kume, Tatsuya; Kundu, Anirban; Kurevlev, German; Kurihara, Yoshimasa; Kuriki, Masao; Kuroda, Shigeru; Kuroiwa, Hirotoshi; Kurokawa, Shin-ichi; Kusano, Tomonori; Kush, Pradeep K.; Kutschke, Robert; Kuznetsova, Ekaterina; Kvasnicka, Peter; Kwon, Youngjoon; Labarga, Luis; Lacasta, Carlos; Lackey, Sharon; Lackowski, Thomas W.; Lafaye, Remi; Lafferty, George; Lagorio, Eric; Laktineh, Imad; Lal, Shankar; Laloum, Maurice; Lam, Briant; Lancaster, Mark; Lander, Richard; Lange, Wolfgang; Langenfeld, Ulrich; Langeveld, Willem; Larbalestier, David; Larsen, Ray; Lastovicka, Tomas; Lastovicka-Medin, Gordana; Latina, Andrea; Latour, Emmanuel; Laurent, Lisa; Le, Ba Nam; Le, Duc Ninh; Le Diberder, Francois; Dû, Patrick Le; Lebbolo, Hervé; Lebrun, Paul; Lecoq, Jacques; Lee, Sung-Won; Lehner, Frank; Leibfritz, Jerry; Lenkszus, Frank; Lesiak, Tadeusz; Levy, Aharon; Lewandowski, Jim; Leyh, Greg; Li, Cheng; Li, Chong Sheng; Li, Chun Hua; Li, Da Zhang; Li, Gang; Li, Jin; Li, Shao Peng; Li, Wei Ming; Li, Weiguo; Li, Xiao Ping; Li, Xue-Qian; Li, Yuanjing; Li, Yulan; Li, Zenghai; Li, Zhong Quan; Liang, Jian Tao; Liao, Yi; Lilje, Lutz; Guilherme Lima, J.; Lintern, Andrew J.; Lipton, Ronald; List, Benno; List, Jenny; Liu, Chun; Liu, Jian Fei; Liu, Ke Xin; Liu, Li Qiang; Liu, Shao Zhen; Liu, Sheng Guang; Liu, Shubin; Liu, Wanming; Liu, Wei Bin; Liu, Ya Ping; Liu, Yu Dong; Lockyer, Nigel; Logan, Heather E.; Logatchev, Pavel V.; Lohmann, Wolfgang; Lohse, Thomas; Lola, Smaragda; Lopez-Virto, Amparo; Loveridge, Peter; Lozano, Manuel; Lu, Cai-Dian; Lu, Changguo; Lu, Gong-Lu; Lu, Wen Hui; Lubatti, Henry; Lucotte, Arnaud; Lundberg, Björn; Lundin, Tracy; Luo, Mingxing; Luong, Michel; Luth, Vera; Lutz, Benjamin; Lutz, Pierre; Lux, Thorsten; Luzniak, Pawel; Lyapin, Alexey; Lykken, Joseph; Lynch, Clare; Ma, Li; Ma, Lili; Ma, Qiang; Ma, Wen-Gan; Macfarlane, David; Maciel, Arthur; MacLeod, Allan; MacNair, David; Mader, Wolfgang; Magill, Stephen; Magnan, Anne-Marie; Maiheu, Bino; Maity, Manas; Majchrzak, Millicent; Majumder, Gobinda; Makarov, Roman; Makowski, Dariusz; Malaescu, Bogdan; Mallik, C.; Mallik, Usha; Malton, Stephen; Malyshev, Oleg B.; Malysheva, Larisa I.; Mammosser, John; Mamta; Mamuzic, Judita; Manen, Samuel; Manghisoni, Massimo; Manly, Steven; Marcellini, Fabio; Marcisovsky, Michal; Markiewicz, Thomas W.; Marks, Steve; Marone, Andrew; Marti, Felix; Martin, Jean-Pierre; Martin, Victoria; Martin-Chassard, Gisèle; Martinez, Manel; Martinez-Rivero, Celso; Martsch, Dennis; Martyn, Hans-Ulrich; Maruyama, Takashi; Masuzawa, Mika; Mathez, Hervé; Matsuda, Takeshi; Matsumoto, Hiroshi; Matsumoto, Shuji; Matsumoto, Toshihiro; Matsunaga, Hiroyuki; Mättig, Peter; Mattison, Thomas; Mavromanolakis, Georgios; Mawatari, Kentarou; Mazzacane, Anna; McBride, Patricia; McCormick, Douglas; McCormick, Jeremy; McDonald, Kirk T.; McGee, Mike; McIntosh, Peter; McKee, Bobby; McPherson, Robert A.; Meidlinger, Mandi; Meier, Karlheinz; Mele, Barbara; Meller, Bob; Melzer-Pellmann, Isabell-Alissandra; Mendez, Hector; Mercer, Adam; Merkin, Mikhail; Meshkov, I.N.; Messner, Robert; Metcalfe, Jessica; Meyer, Chris; Meyer, Hendrik; Meyer, Joachim; Meyer, Niels; Meyners, Norbert; Michelato, Paolo; Michizono, Shinichiro; Mihalcea, Daniel; Mihara, Satoshi; Mihara, Takanori; Mikami, Yoshinari; Mikhailichenko, Alexander A.; Milardi, Catia; Miller, David J.; Miller, Owen; Miller, Roger J.; Milstene, Caroline; Mimashi, Toshihiro; Minashvili, Irakli; Miquel, Ramon; Mishra, Shekhar; Mitaroff, Winfried; Mitchell, Chad; Miura, Takako; Miyamoto, Akiya; Miyata, Hitoshi; Mjörnmark, Ulf; Mnich, Joachim; Moenig, Klaus; Moffeit, Kenneth; Mokhov, Nikolai; Molloy, Stephen; Monaco, Laura; Monasterio, Paul R.; Montanari, Alessandro; Moon, Sung Ik; Moortgat-Pick, Gudrid A.; Mora de Freitas, Paulo; Morel, Federic; Moretti, Stefano; Morgunov, Vasily; Mori, Toshinori; Morin, Laurent; Morisseau, François; Morita, Yoshiyuki; Morita, Youhei; Morita, Yuichi; Morozov, Nikolai; Morozumi, Yuichi; Morse, William; Moser, Hans-Guenther; Moultaka, Gilbert; Mtingwa, Sekazi; Mudrinic, Mihajlo; Mueller, Alex; Mueller, Wolfgang; Muennich, Astrid; Muhlleitner, Milada Margarete; Mukherjee, Bhaskar; Mukhopadhyaya, Biswarup; Müller, Thomas; Munro, Morrison; Murayama, Hitoshi; Muto, Toshiya; Myneni, Ganapati Rao; Nabhiraj, P.Y.; Nagaitsev, Sergei; Nagamine, Tadashi; Nagano, Ai; Naito, Takashi; Nakai, Hirotaka; Nakajima, Hiromitsu; Nakamura, Isamu; Nakamura, Tomoya; Nakanishi, Tsutomu; Nakao, Katsumi; Nakao, Noriaki; Nakayoshi, Kazuo; Nam, Sang; Namito, Yoshihito; Namkung, Won; Nantista, Chris; Napoly, Olivier; Narain, Meenakshi; Naroska, Beate; Nauenberg, Uriel; Nayyar, Ruchika; Neal, Homer; Nelson, Charles; Nelson, Janice; Nelson, Timothy; Nemecek, Stanislav; Neubauer, Michael; Neuffer, David; Newman, Myriam Q.; Nezhevenko, Oleg; Ng, Cho-Kuen; Nguyen, Anh Ky; Nguyen, Minh; Van Nguyen Thi,Hong; Niebuhr, Carsten; Niehoff, Jim; Niezurawski, Piotr; Nishitani, Tomohiro; Nitoh, Osamu; Noguchi, Shuichi; Nomerotski, Andrei; Noonan, John; Norbeck, Edward; Nosochkov, Yuri; Notz, Dieter; Nowak, Grazyna; Nowak, Hannelies; Noy, Matthew; Nozaki, Mitsuaki; Nyffeler, Andreas; Nygren, David; Oddone, Piermaria; O'Dell, Joseph; Oh, Jong-Seok; Oh, Sun Kun; Ohkuma, Kazumasa; Ohlerich, Martin; Ohmi, Kazuhito; Ohnishi, Yukiyoshi; Ohsawa, Satoshi; Ohuchi, Norihito; Oide, Katsunobu; Okada, Nobuchika; Okada, Yasuhiro; Okamura, Takahiro; Okugi, Toshiyuki; Okumi, Shoji; Okumura, Ken-ichi; Olchevski, Alexander; Oliver, William; Olivier, Bob; Olsen, James; Olsen, Jeff; Olsen, Stephen; Olshevsky, A.G.; Olsson, Jan; Omori, Tsunehiko; Onel, Yasar; Onengut, Gulsen; Ono, Hiroaki; Onoprienko, Dmitry; Oreglia, Mark; Oren, Will; Orimoto, Toyoko J.; Oriunno, Marco; Orlandea, Marius Ciprian; Oroku, Masahiro; Orr, Lynne H.; Orr, Robert S.; Oshea, Val; Oskarsson, Anders; Osland, Per; Ossetski, Dmitri; Österman, Lennart; Ostiguy, Francois; Otono, Hidetoshi; Ottewell, Brian; Ouyang, Qun; Padamsee, Hasan; Padilla, Cristobal; Pagani, Carlo; Palmer, Mark A.; Pam, Wei Min; Pande, Manjiri; Pande, Rajni; Pandit, V.S.; Pandita, P.N.; Pandurovic, Mila; Pankov, Alexander; Panzeri, Nicola; Papandreou, Zisis; Paparella, Rocco; Para, Adam; Park, Hwanbae; Parker, Brett; Parkes, Chris; Parma, Vittorio; Parsa, Zohreh; Parsons, Justin; Partridge, Richard; Pasquinelli, Ralph; Pásztor, Gabriella; Paterson, Ewan; Patrick, Jim; Patteri, Piero; Ritchie Patterson, J.; Pauletta, Giovanni; Paver, Nello; Pavlicek, Vince; Pawlik, Bogdan; Payet, Jacques; Pchalek, Norbert; Pedersen, John; Pei, Guo Xi; Pei, Shi Lun; Pelka, Jerzy; Pellegrini, Giulio; Pellett, David; Peng, G.X.; Penn, Gregory; Penzo, Aldo; Perry, Colin; Peskin, Michael; Peters, Franz; Petersen, Troels Christian; Peterson, Daniel; Peterson, Thomas; Petterson, Maureen; Pfeffer, Howard; Pfund, Phil; Phelps, Alan; Van Phi, Quang; Phillips, Jonathan; Piccolo, Marcello; Piemontese, Livio; Pierini, Paolo; Thomas Piggott, W.; Pike, Gary; Pillet, Nicolas; Jayawardena, Talini Pinto; Piot, Phillippe; Pitts, Kevin; Pivi, Mauro; Plate, Dave; Pleier, Marc-Andre; Poblaguev, Andrei; Poehler, Michael; Poelker, Matthew; Poffenberger, Paul; Pogorelsky, Igor; Poirier, Freddy; Poling, Ronald; Poole, Mike; Popescu, Sorina; Popielarski, John; Pöschl, Roman; Postranecky, Martin; Potukochi, Prakash N.; Prast, Julie; Prat, Serge; Preger, Miro; Prepost, Richard; Price, Michael; Proch, Dieter; Puntambekar, Avinash; Qin, Qing; Qu, Hua Min; Quadt, Arnulf; Quesnel, Jean-Pierre; Radeka, Veljko; Rahmat, Rahmat; Rai, Santosh Kumar; Raimondi, Pantaleo; Ramberg, Erik; Ranjan, Kirti; Rao, Sista V.L.S.; Raspereza, Alexei; Ratti, Alessandro; Ratti, Lodovico; Raubenheimer, Tor; Raux, Ludovic; Ravindran, V.; Raychaudhuri, Sreerup; Re, Valerio; Rease, Bill; Reece, Charles E.; Regler, Meinhard; Rehlich, Kay; Reichel, Ina; Reichold, Armin; Reid, John; Reid, Ron; Reidy, James; Reinhard, Marcel; Renz, Uwe; Repond, Jose; Resta-Lopez, Javier; Reuen, Lars; Ribnik, Jacob; Rice, Tyler; Richard, François; Riemann, Sabine; Riemann, Tord; Riles, Keith; Riley, Daniel; Rimbault, Cécile; Rindani, Saurabh; Rinolfi, Louis; Risigo, Fabio; Riu, Imma; Rizhikov, Dmitri; Rizzo, Thomas; Rochford, James H.; Rodriguez, Ponciano; Roeben, Martin; Rolandi, Gigi; Roodman, Aaron; Rosenberg, Eli; Roser, Robert; Ross, Marc; Rossel, François; Rossmanith, Robert; Roth, Stefan; Rougé, André; Rowe, Allan; Roy, Amit; Roy, Sendhunil B.; Roy, Sourov; Royer, Laurent; Royole-Degieux, Perrine; Royon, Christophe; Ruan, Manqi; Rubin, David; Ruehl, Ingo; Jimeno, Alberto Ruiz; Ruland, Robert; Rusnak, Brian; Ryu, Sun-Young; Sabbi, Gian Luca; Sadeh, Iftach; Sadygov, Ziraddin Y; Saeki, Takayuki; Sagan, David; Sahni, Vinod C.; Saini, Arun; Saito, Kenji; Saito, Kiwamu; Sajot, Gerard; Sakanaka, Shogo; Sakaue, Kazuyuki; Salata, Zen; Salih, Sabah; Salvatore, Fabrizio; Samson, Joergen; Sanami, Toshiya; Levi Sanchez, Allister; Sands, William; Santic, John; Sanuki, Tomoyuki; Sapronov, Andrey; Sarkar, Utpal; Sasao, Noboru; Satoh, Kotaro; Sauli, Fabio; Saunders, Claude; Saveliev, Valeri; Savoy-Navarro, Aurore; Sawyer, Lee; Saxton, Laura; Schäfer, Oliver; Schälicke, Andreas; Schade, Peter; Schaetzel, Sebastien; Scheitrum, Glenn; Schibler, Emilie; Schindler, Rafe; Schlösser, Markus; Schlueter, Ross D.; Schmid, Peter; Schmidt, Ringo Sebastian; Schneekloth, Uwe; Schreiber, Heinz Juergen; Schreiber, Siegfried; Schroeder, Henning; Peter Schüler, K.; Schulte, Daniel; Schultz-Coulon, Hans-Christian; Schumacher, Markus; Schumann, Steffen; Schumm, Bruce A.; Schwienhorst, Reinhard; Schwierz, Rainer; Scott, Duncan J.; Scuri, Fabrizio; Sefkow, Felix; Sefri, Rachid; Seguin-Moreau, Nathalie; Seidel, Sally; Seidman, David; Sekmen, Sezen; Seletskiy, Sergei; Senaha, Eibun; Senanayake, Rohan; Sendai, Hiroshi; Sertore, Daniele; Seryi, Andrei; Settles, Ronald; Sever, Ramazan; Shales, Nicholas; Shao, Ming; Shelkov, G.A.; Shepard, Ken; Shepherd-Themistocleous, Claire; Sheppard, John C.; Shi, Cai Tu; Shidara, Tetsuo; Shim, Yeo-Jeong; Shimizu, Hirotaka; Shimizu, Yasuhiro; Shimizu, Yuuki; Shimogawa, Tetsushi; Shin, Seunghwan; Shioden, Masaomi; Shipsey, Ian; Shirkov, Grigori; Shishido, Toshio; Shivpuri, Ram K.; Shrivastava, Purushottam; Shulga, Sergey; Shumeiko, Nikolai; Shuvalov, Sergey; Si, Zongguo; Siddiqui, Azher Majid; Siegrist, James; Simon, Claire; Simrock, Stefan; Sinev, Nikolai; Singh, Bhartendu K.; Singh, Jasbir; Singh, Pitamber; Singh, R.K.; Singh, S.K.; Singini, Monito; Sinha, Anil K.; Sinha, Nita; Sinha, Rahul; Sinram, Klaus; Sissakian, A.N.; Skachkov, N.B.; Skrinsky, Alexander; Slater, Mark; Slominski, Wojciech; Smiljanic, Ivan; Smith, A J Stewart; Smith, Alex; Smith, Brian J.; Smith, Jeff; Smith, Jonathan; Smith, Steve; Smith, Susan; Smith, Tonee; Neville Snodgrass, W.; Sobloher, Blanka; Sohn, Young-Uk; Solidum, Ruelson; Solyak, Nikolai; Son, Dongchul; Sonmez, Nasuf; Sopczak, Andre; Soskov, V.; Spencer, Cherrill M.; Spentzouris, Panagiotis; Speziali, Valeria; Spira, Michael; Sprehn, Daryl; Sridhar, K.; Srivastava, Asutosh; St. Lorant, Steve; Stahl, Achim; Stanek, Richard P.; Stanitzki, Marcel; Stanley, Jacob; Stefanov, Konstantin; Stein, Werner; Steiner, Herbert; Stenlund, Evert; Stern, Amir; Sternberg, Matt; Stockinger, Dominik; Stockton, Mark; Stoeck, Holger; Strachan, John; Strakhovenko, V.; Strauss, Michael; Striganov, Sergei I.; Strologas, John; Strom, David; Strube, Jan; Stupakov, Gennady; Su, Dong; Sudo, Yuji; Suehara, Taikan; Suehiro, Toru; Suetsugu, Yusuke; Sugahara, Ryuhei; Sugimoto, Yasuhiro; Sugiyama, Akira; Suh, Jun Suhk; Sukovic, Goran; Sun, Hong; Sun, Stephen; Sun, Werner; Sun, Yi; Sun, Yipeng; Suszycki, Leszek; Sutcliffe, Peter; Suthar, Rameshwar L.; Suwada, Tsuyoshi; Suzuki, Atsuto; Suzuki, Chihiro; Suzuki, Shiro; Suzuki, Takashi; Swent, Richard; Swientek, Krzysztof; Swinson, Christina; Syresin, Evgeny; Szleper, Michal; Tadday, Alexander; Takahashi, Rika; Takahashi, Tohru; Takano, Mikio; Takasaki, Fumihiko; Takeda, Seishi; Takenaka, Tateru; Takeshita, Tohru; Takubo, Yosuke; Tanaka, Masami; Tang, Chuan Xiang; Taniguchi, Takashi; Tantawi, Sami; Tapprogge, Stefan; Tartaglia, Michael A.; Tassielli, Giovanni Francesco; Tauchi, Toshiaki; Tavian, Laurent; Tawara, Hiroko; Taylor, Geoffrey; Telnov, Alexandre V.; Telnov, Valery; Tenenbaum, Peter; Teodorescu, Eliza; Terashima, Akio; Terracciano, Giuseppina; Terunuma, Nobuhiro; Teubner, Thomas; Teuscher, Richard; Theilacker, Jay; Thomson, Mark; Tice, Jeff; Tigner, Maury; Timmermans, Jan; Titov, Maxim; Tokareva, N.A.; Tollefson, Kirsten; Tomasek, Lukas; Tomovic, Savo; Tompkins, John; Tonutti, Manfred; Topkar, Anita; Toprek, Dragan; Toral, Fernando; Torrence, Eric; Traversi, Gianluca; Trimpl, Marcel; Mani Tripathi, S.; Trischuk, William; Trodden, Mark; Trubnikov, G.V.; Tschirhart, Robert; Tskhadadze, Edisher; Tsuchiya, Kiyosumi; Tsukamoto, Toshifumi; Tsunemi, Akira; Tucker, Robin; Turchetta, Renato; Tyndel, Mike; Uekusa, Nobuhiro; Ueno, Kenji; Umemori, Kensei; Ummenhofer, Martin; Underwood, David; Uozumi, Satoru; Urakawa, Junji; Urban, Jeremy; Uriot, Didier; Urner, David; Ushakov, Andrei; Usher, Tracy; Uzunyan, Sergey; Vachon, Brigitte; Valerio, Linda; Valin, Isabelle; Valishev, Alex; Vamra, Raghava; Van der Graaf, Harry; Van Kooten, Rick; Van Zandbergen, Gary; Vanel, Jean-Charles; Variola, Alessandro; Varner, Gary; Velasco, Mayda; Velte, Ulrich; Velthuis, Jaap; Vempati, Sundir K.; Venturini, Marco; Vescovi, Christophe; Videau, Henri; Vila, Ivan; Vincent, Pascal; Virey, Jean-Marc; Visentin, Bernard; Viti, Michele; Vo, Thanh Cuong; Vogel, Adrian; Vogt, Harald; von Toerne, Eckhard; Vorozhtsov, S.B.; Vos, Marcel; Votava, Margaret; Vrba, Vaclav; Wackeroth, Doreen; Wagner, Albrecht; Wagner, Carlos E.M.; Wagner, Stephen; Wake, Masayoshi; Walczak, Roman; Walkowiak, Wolfgang; Wallon, Samuel; Walsh, Roberval; Walston, Sean; Waltenberger, Wolfgang; Walz, Dieter; Wang, Chao En; Wang, Chun Hong; Wang, Dou; Wang, Faya; Wang, Guang Wei; Wang, Haitao; Wang, Jiang; Wang, Jiu Qing; Wang, Juwen; Wang, Lanfa; Wang, Lei; Wang, Min-Zu; Wang, Qing; Wang, Shu Hong; Wang, Xiaolian; Wang, Xue-Lei; Wang, Yi Fang; Wang, Zheng; Wanzenberg, Rainer; Ward, Bennie; Ward, David; Warmbein, Barbara; Warner, David W.; Warren, Matthew; Washio, Masakazu; Watanabe, Isamu; Watanabe, Ken; Watanabe, Takashi; Watanabe, Yuichi; Watson, Nigel; Wattimena, Nanda; Wayne, Mitchell; Weber, Marc; Weerts, Harry; Weiglein, Georg; Weiland, Thomas; Weinzierl, Stefan; Weise, Hans; Weisend, John; Wendt, Manfred; Wendt, Oliver; Wenzel, Hans; Wenzel, William A.; Wermes, Norbert; Werthenbach, Ulrich; Wesseln, Steve; Wester, William; White, Andy; White, Glen R.; Wichmann, Katarzyna; Wienemann, Peter; Wierba, Wojciech; Wilksen, Tim; Willis, William; Wilson, Graham W.; Wilson, John A.; Wilson, Robert; Wing, Matthew; Winter, Marc; Wirth, Brian D.; Wolbers, Stephen A.; Wolff, Dan; Wolski, Andrzej; Woodley, Mark D.; Woods, Michael; Woodward, Michael L.; Woolliscroft, Timothy; Worm, Steven; Wormser, Guy; Wright, Dennis; Wright, Douglas; Wu, Andy; Wu, Tao; Wu, Yue Liang; Xella, Stefania; Xia, Guoxing; Xia, Lei; Xiao, Aimin; Xiao, Liling; Xie, Jia Lin; Xing, Zhi-Zhong; Xiong, Lian You; Xu, Gang; Xu, Qing Jing; Yajnik, Urjit A.; Yakimenko, Vitaly; Yamada, Ryuji; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Hitoshi; Yamamoto, Masahiro; Yamamoto, Naoto; Yamamoto, Richard; Yamamoto, Yasuchika; Yamanaka, Takashi; Yamaoka, Hiroshi; Yamashita, Satoru; Yamazaki, Hideki; Yan, Wenbiao; Yang, Hai-Jun; Yang, Jin Min; Yang, Jongmann; Yang, Zhenwei; Yano, Yoshiharu; Yazgan, Efe; Yeh, G.P.; Yilmaz, Hakan; Yock, Philip; Yoda, Hakutaro; Yoh, John; Yokoya, Kaoru; Yokoyama, Hirokazu; York, Richard C.; Yoshida, Mitsuhiro; Yoshida, Takuo; Yoshioka, Tamaki; Young, Andrew; Yu, Cheng Hui; Yu, Jaehoon; Yu, Xian Ming; Yuan, Changzheng; Yue, Chong-Xing; Yue, Jun Hui; Zacek, Josef; Zagorodnov, Igor; Zalesak, Jaroslav; Zalikhanov, Boris; Zarnecki, Aleksander Filip; Zawiejski, Leszek; Zeitnitz, Christian; Zeller, Michael; Zerwas, Dirk; Zerwas, Peter; Zeyrek, Mehmet; Zhai, Ji Yuan; Zhang, Bao Cheng; Zhang, Bin; Zhang, Chuang; Zhang, He; Zhang, Jiawen; Zhang, Jing; Zhang, Jing Ru; Zhang, Jinlong; Zhang, Liang; Zhang, X.; Zhang, Yuan; Zhang, Zhige; Zhang, Zhiqing; Zhang, Ziping; Zhao, Haiwen; Zhao, Ji Jiu; Zhao, Jing Xia; Zhao, Ming Hua; Zhao, Sheng Chu; Zhao, Tianchi; Zhao, Tong Xian; Zhao, Zhen Tang; Zhao, Zhengguo; Zhou, De Min; Zhou, Feng; Zhou, Shun; Zhu, Shou Hua; Zhu, Xiong Wei; Zhukov, Valery; Zimmermann, Frank; Ziolkowski, Michael; Zisman, Michael S.; Zomer, Fabian; Zong, Zhang Guo; Zorba, Osman; Zutshi, Vishnu

    2007-01-01

    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC.

  20. Design and construction of the first Iranian powerful industrial electron accelerator

    Directory of Open Access Journals (Sweden)

    AM Poursaleh

    2015-09-01

    Full Text Available In This paper we will introduce the process of design and manufacturing an electron accelerator with 10MeV energy and 100kW power as the first Iranian powerful industrial electron accelerator. This accelerator designed based on modeling of one of the most powerful industrial accelerator called Rhodotron. But the design of the accelerator in a way that can be localize by relying on domestic industries. So although it looks like a Rhodotron accelerator structure but has some different in design and manufacture of components, the results are satisfactory

  1. Prototyping high-gradient mm-wave accelerating structures

    International Nuclear Information System (INIS)

    Nanni, Emilio A.; Dolgashev, Valery A.; Haase, Andrew; Neilson, Jeffrey; Tantawi, Sami

    2017-01-01

    We present single-cell accelerating structures designed for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures are π-mode standing-wave cavities fed with a TM_0_1 circular waveguide. The structures are fabricated using precision milling out of two metal blocks, and the blocks are joined with diffusion bonding and brazing. The impact of fabrication and joining techniques on the cell geometry and RF performance will be discussed. First prototypes had a measured Q_0 of 2800, approaching the theoretical design value of 3300. The geometry of these accelerating structures are as close as practical to singlecell standing-wave X-band accelerating structures more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. Furthermore, the structures will be powered with short pulses from a MW gyrotron oscillator. RF power of 1 MW may allow an accelerating gradient of 400 MeV/m to be reached.

  2. Post accelerator of the IH type structure

    International Nuclear Information System (INIS)

    Chen Ming

    2002-01-01

    The principle, structure, adjustment of the gap voltage, beam dynamic, RF system and the bunchers of the post-accelerator with Interdigital-H type structure, which was developed by the author and Technical University Munich in four years, is described. The energy of ions with mass of three was increased from 340 keV to 1.74 MeV, when resonant frequency of 84.2 MHz and input RF power of 3 kW. The effective shunt impedance reached to 408 MΩ/m. The commissioning was succeeded with H 3 + ion beams. The output energy of H 3 + ion beams reached the design value. The two harmonic double drift buncher used by the IH structure bunches the beam to the bunches with the width of 360 ps. Then the acceptance of the IH structure is increased to 240 degree. Its shunt impedance is three times higher than former single gap bunchers used by TUM and the length of the buncher system is one fifth of former one only because the use of λ/4 coaxial cavities with double gaps

  3. Design Concepts for Muon-Based Accelerators

    International Nuclear Information System (INIS)

    Ryne, R. D.; Berg, J. S.; Kirk, H. G.; Palmer, R. B.; Stratkis, D.; Alexahin, Y.; Bross, A.; Gollwitzer, K.; Mokhov, N. V.; Neuffer, D.; Palmer, M. A.; Yonehara, K.; Snopok, P.; Bogacz, A.; Roberts, T. J.; Delahaye, J. P.

    2015-01-01

    Muon-based accelerators have the potential to enable facilities at both the Intensity and the Energy Frontiers. Muon storage rings can serve as high precision neutrino sources, and a muon collider is an ideal technology for a TeV or multi-TeV collider. Progress in muon accelerator designs has advanced steadily in recent years. In regard to 6D muon cooling, detailed and realistic designs now exist that provide more than 5 order-of-magnitude emittance reduction. Furthermore, detector performance studies indicate that with suitable pixelation and timing resolution, backgrounds in the collider detectors can be significantly reduced, thus enabling high-quality physics results. Thanks to these and other advances in design & simulation of muon systems, technology development, and systems demonstrations, muon storage-ring-based neutrino sources and a muon collider appear more feasible than ever before. A muon collider is now arguably among the most compelling approaches to a multi-TeV lepton collider. This paper summarizes the current status of design concepts for muon-based accelerators for neutrino factories and a muon collider.

  4. Accelerating Science Driven System Design With RAMP

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzynek, John [Univ. of California, Berkeley, CA (United States)

    2015-05-01

    Researchers from UC Berkeley, in collaboration with the Lawrence Berkeley National Lab, are engaged in developing an Infrastructure for Synthesis with Integrated Simulation (ISIS). The ISIS Project was a cooperative effort for “application-driven hardware design” that engages application scientists in the early parts of the hardware design process for future generation supercomputing systems. This project served to foster development of computing systems that are better tuned to the application requirements of demanding scientific applications and result in more cost-effective and efficient HPC system designs. In order to overcome long conventional design-cycle times, we leveraged reconfigurable devices to aid in the design of high-efficiency systems, including conventional multi- and many-core systems. The resulting system emulation/prototyping environment, in conjunction with the appropriate intermediate abstractions, provided both a convenient user programming experience and retained flexibility, and thus efficiency, of a reconfigurable platform. We initially targeted the Berkeley RAMP system (Research Accelerator for Multiple Processors) as that hardware emulation environment to facilitate and ultimately accelerate the iterative process of science-driven system design. Our goal was to develop and demonstrate a design methodology for domain-optimized computer system architectures. The tangible outcome is a methodology and tools for rapid prototyping and design-space exploration, leading to highly optimized and efficient HPC systems.

  5. CTF3 Drive Beam Accelerating Structures

    CERN Document Server

    Jensen, E

    2002-01-01

    The 3 GHz drive beam accelerator of the CLIC Test Facility CTF3, currently under construction at CERN, will be equipped with 16 novel SICA (Slotted Iris – Constant Aperture) accelerating structures. The slotted irises couple out the potentially disruptive induced transverse HOM energy to integrated silicon carbide loads (dipole mode Q's below 20). The use of nose cones for detuning allows a constant inner aperture (34 mm). The structures will be 1.2 m long and consist of 34 cells. A first 6 cell prototype structure has been tested successfully up to power levels of 100 MW (nominal: 30 MW), corresponding to surface electric field levels of 180 MV/m.

  6. Straightness measurements for accelerator structures

    International Nuclear Information System (INIS)

    Schwarz, W.

    1996-01-01

    The cavity structures of the S-Band Linear Collider have to be aligned better than 30 μm rms over their length of 6 m. In this paper relevant techniques for straightness measurements are described. Further the results of straightness measurements of the first test modules are discussed. (author)

  7. Detector design studies for Turkish Accelerator Center

    Science.gov (United States)

    Aksu, Burçin; Piliçer, Ercan

    2017-02-01

    The proposed Particle Factory detector at Turkish Accelerator Center (TAC-PF) aims to search for charm physics, CP violation and mixing of D0 mesons as well as new physics effects by investigating head-on collisions of 1 GeV electron from Energy Recovery Linac (ERL) with 3.56 GeV positrons from synchrotron storage ring. In this work, we constructed the TAC-PF detector design by using a recently developed framework namely Detector Description for High Energy Physics (DD4hep). The baseline TAC-PF detector design and its qualifications were summarized, followed by a general description.

  8. Next Linear Collider Test Accelerator conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    This document presents the scientific justification and the conceptual design for the {open_quotes}Next Linear Collider Test Accelerator{close_quotes} (NLCTA) at SLAC. The goals of the NLCTA are to integrate the new technologies of X-band accelerator structures and rf systems being developed for the Next Linear Collider, to measure the growth of the {open_quotes}dark current{close_quotes} generated by rf field emission in the accelerator, to demonstrate multi-bunch beam-loading energy compensation and suppression of higher-order deflecting modes, and to measure any transverse components of the accelerating field. The NLCTA will be a 42-meter-long beam line consisting, consecutively, of a thermionic-cathode gun, an X-band buncher, a magnetic chicane, six 1.8-meter-long sections of 11.4-GHz accelerator structure, and a magnetic spectrometer. Initially, the unloaded accelerating gradient will be 50 MV/m. A higher-gradient upgrade option eventually would increase the unloaded gradient to 100 MV/m.

  9. The grating as an accelerating structure

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1991-02-01

    This report considers the use of a diffraction grating as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of a grating. Calculations are made of the strength of the accelerating modes for structures with π and 2π phase advance per period and for incident waves polarized with either the E or H vector along the grooves of the grating. We consider examples of using gratings in a laser linac and in a grating lens. We also briefly examine previous results published about this subject. 36 refs

  10. Evolutionary optimization methods for accelerator design

    Science.gov (United States)

    Poklonskiy, Alexey A.

    Many problems from the fields of accelerator physics and beam theory can be formulated as optimization problems and, as such, solved using optimization methods. Despite growing efficiency of the optimization methods, the adoption of modern optimization techniques in these fields is rather limited. Evolutionary Algorithms (EAs) form a relatively new and actively developed optimization methods family. They possess many attractive features such as: ease of the implementation, modest requirements on the objective function, a good tolerance to noise, robustness, and the ability to perform a global search efficiently. In this work we study the application of EAs to problems from accelerator physics and beam theory. We review the most commonly used methods of unconstrained optimization and describe the GATool, evolutionary algorithm and the software package, used in this work, in detail. Then we use a set of test problems to assess its performance in terms of computational resources, quality of the obtained result, and the tradeoff between them. We justify the choice of GATool as a heuristic method to generate cutoff values for the COSY-GO rigorous global optimization package for the COSY Infinity scientific computing package. We design the model of their mutual interaction and demonstrate that the quality of the result obtained by GATool increases as the information about the search domain is refined, which supports the usefulness of this model. We Giscuss GATool's performance on the problems suffering from static and dynamic noise and study useful strategies of GATool parameter tuning for these and other difficult problems. We review the challenges of constrained optimization with EAs and methods commonly used to overcome them. We describe REPA, a new constrained optimization method based on repairing, in exquisite detail, including the properties of its two repairing techniques: REFIND and REPROPT. We assess REPROPT's performance on the standard constrained

  11. Post-accelerator LINAC design for the VECC RIB project

    Indian Academy of Sciences (India)

    accelerator LINAC design for the VECC RIB project. Arup Bandyopadhyay. Volume 59 Issue 6 December ... and LINAC modules for the post-acceleration. The design aspects of these postaccelerator LINAC modules will be discussed in this paper.

  12. Physics design of an accelerator for an accelerator-driven subcritical system

    Directory of Open Access Journals (Sweden)

    Zhihui Li

    2013-08-01

    Full Text Available An accelerator-driven subcritical system (ADS program was launched in China in 2011, which aims to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power in multiple phases lasting about 20 years. The driver linac is defined to be 1.5 GeV in energy, 10 mA in current and in cw operation mode. To meet the extremely high reliability and availability, the linac is designed with much installed margin and fault tolerance, including hot-spare injectors and local compensation method for key element failures. The accelerator complex consists of two parallel 10-MeV injectors, a joint medium-energy beam transport line, a main linac, and a high-energy beam transport line. The superconducting acceleration structures are employed except for the radio frequency quadrupole accelerators (RFQs which are at room temperature. The general design considerations and the beam dynamics design of the driver linac complex are presented here.

  13. Optimal cells for TESLA accelerating structure

    CERN Document Server

    Shemelin, Valery D; Geng, R L

    2003-01-01

    The shape of TESLA accelerating structure can be improved to decrease the peak surface magnetic field by sacrificing and increasing peak surface electric field. This sacrifice may be necessary because the magnetic field is a hard limit but electric field emission can be decreased by processing. For the case of superconducting cavities RF magnetic strength should be more of a concern.

  14. Fabrication and cold test of dielectric assist accelerating structure

    Science.gov (United States)

    Satoh, D.; Yoshida, M.; Hayashizaki, N.

    2017-09-01

    We present the detailed description of a successful design and cold testing of the dielectric assist accelerating (DAA) structure. The DAA structure consists of ultralow-loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure. The advantage of the DAA structure is that it has an extremely high quality factor and a very high shunt impedance at room temperature since the electromagnetic field distribution of accelerating mode can be controlled by dielectric parts so that the wall loss on the metallic surface is greatly reduced. A prototype of the five-cell DAA structure was designed and built at C-band (5.712 GHz), and cold tested. Three types of dielectric cell structure, "regular," "end," and "hybrid" dielectric cells, are fabricated by sintering high-purity magnesia. The prototype was assembled by stacking these cells in the hollow copper cylinder, whose two ends are closed by copper plates. The resonant frequency of the prototype was tuned to the desired frequency by machining only end copper plates. The unloaded quality factor of the accelerating mode was measured at 119,314 and the shunt impedance per unit length of the prototype was estimated from the experimental results of the bead pull measurement as Zsh=617 M Ω /m , which were within 2 percent of the design values. The field distribution of accelerating mode was also measured by the bead pull method, and its results agreed well with simulation results.

  15. Accelerator-driven subcritical facility:Conceptual design development

    Science.gov (United States)

    Gohar, Yousry; Bolshinsky, Igor; Naberezhnev, Dmitry; Duo, Jose; Belch, Henry; Bailey, James

    2006-06-01

    A conceptual design development of an accelerator-driven subcritical facility has been carried out in the preparation of a joint activity with Kharkov Institute of Physics and Technology of Ukraine. The main functions of the facility are the medical isotope production and the support of the Ukraine nuclear industry. An electron accelerator is considered to drive the subcritical assembly. The neutron source intensity and spectrum have been studied. The energy deposition, spatial neutron generation, neutron utilization fraction, and target dimensions have been quantified to define the main target performance parameters, and to select the target material and beam parameters. Different target conceptual designs have been developed based the engineering requirements including heat transfer, thermal hydraulics, structure, and material issues. The subcritical assembly is designed to obtain the highest possible neutron flux level with a Keff of 0.98. Different fuel materials, uranium enrichments, and reflector materials are considered in the design process. The possibility of using low enrichment uranium without penalizing the facility performance is carefully evaluated. The mechanical design of the facility has been developed to maximize its utility and minimize the time for replacing the target and the fuel assemblies. Safety, reliability, and environmental considerations are included in the facility conceptual design. The facility is configured to accommodate future design improvements, upgrades, and new missions. In addition, it has large design margins to accommodate different operating conditions and parameters. In this paper, the conceptual design and the design analyses of the facility will be presented.

  16. CLIC: The CLIC accelerator design and performance

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    The Compact Linear Collider (CLIC) is a future electron-positron collider under study. It foresees e+e- collisions at centre-of-mass energies ranging from a few hundred GeV up to 3 TeV. The CLIC study is an international collaboration hosted by CERN. The lectures provide a broad overview of the CLIC project, covering the physics potential, the particle detectors and the accelerator. An overview of the CLIC physics opportunities is presented. These are best exploited in a staged construction and operation scenario of the collider. The detector technologies, fulfilling CLIC performance requirements and currently under study, are described. The accelerator design and performance, together with its major technologies, are presented in the light of ongoing component tests and large system tests. The status of the optimisation studies (e.g. for cost and power) of the CLIC complex for the proposed energy staging is included. One lecture is dedicated to the use of CLIC technologies in free electron lasers and other ...

  17. Unique space saving accelerator cavity design

    International Nuclear Information System (INIS)

    Kim, H.; Fugitt, J.; Crosby, F.; Johnson, R.

    1981-03-01

    A cavity with 3 series gaps was designed and modeled to operate at 70 MHz as a SuperHILAC post acceleration buncher (8.5 MeV/A). Because of a cross-coupling scheme, the 3 cells operate in the 1/2 β lambda mode instead of the β lambda mode of an Alvarez cavity. This coupling results in a cavity with diameter reduced from 3 to less than one meter and a length half that of an Alvarez cavity for the same energy gain. The 3 gaps are electrically in parallel but mechanically in series. The cavity has high Q and shunt impedance. This type of cavity appears to be useful for low velocity beams with β less than or equal to 0.2

  18. CLIC Waveguide Damped Accelerating Structure Studies

    CERN Document Server

    Dehler, M; Wuensch, Walter

    1996-01-01

    Studies of waveguide damped 30 GHz accelerating structures for multibunching in CLIC are described. Frequency discriminated damping using waveguides with a lowest cutoff frequency above the fundamental but below the higher order modes was considered. The wakefield behavior was investigated using time domain MAFIA computations over up to 20 cells and for frequencies up to 150 GHz. A configuration consisting of four T-cross-sectioned waveguides per cell reduces the transverse wake below 1% at typical CLIC bunch spacings.

  19. Unified formulation for linear accelerator design

    International Nuclear Information System (INIS)

    Farkas, Z.D.

    1986-01-01

    Expressions for peak and average powers required to produce a given average gradient in an accelerator section are given. They are valid for both lossy and lossless (superconducting) sections, for both traveling wave and standing wave sections, and for pulsed or continuous wave rf input. The expressions are given in terms of structure parameters that are equally applicable to traveling wave or standing waves. These parameters delineate the effect of wall losses and energy required to build up the field. For both traveling wave and standing wave sections it is possible to make the rf pulse length short enough to make the wall losses negligible at the expense of increased peak power requirement. Therefore, the expressions includes the effects of pulse compression

  20. High Gradient Accelerating Structures for Carbon Therapy Linac

    Energy Technology Data Exchange (ETDEWEB)

    Kutsaev, Sergey; Agustsson, R.; Faillace, L.; Goel, A.; Mustapha, B.; Nassiri, A.; Ostroumov, P.; Plastun, A.; Savin, E.

    2016-05-01

    Carbon therapy is the most promising among techniques for cancer treatment, as it has demonstrated significant improvements in clinical efficiency and reduced toxicity profiles in multiple types of cancer through much better localization of dose to the tumor volume. RadiaBeam, in collaboration with Argonne National Laboratory, are developing an ultra-high gradient linear accelerator, Advanced Compact Carbon Ion Linac (ACCIL), for the delivery of ion-beams with end-energies up to 450 MeV/u for 12C6+ ions and 250 MeV for protons. In this paper, we present a thorough comparison of standing and travelling wave designs for high gradient S-Band accelerating structures operating with ions at varying velocities, relative to the speed of light, in the range 0.3-0.7. In this paper we will compare these types of accelerating structures in terms of RF, beam dynamics and thermo-mechanical performance.

  1. Vacuum arc localization in CLIC prototype radio frequency accelerating structures

    CERN Document Server

    AUTHOR|(CDS)2091976; Koivunen, Visa

    2016-04-04

    A future linear collider capable of reaching TeV collision energies should support accelerating gradients beyond 100 MV/m. At such high fields, the occurrence of vacuum arcs have to be mitigated through conditioning, during which an accelerating structure’s resilience against breakdowns is slowly increased through repeated radio frequency pulsing. Conditioning is very time and resource consuming, which is why developing more efficient procedures is desirable. At CERN, conditioning related research is conducted at the CLIC high-power X-band test stands. Breakdown localization is an important diagnostic tool of accelerating structure tests. Abnormal position distributions highlight issues in structure design, manufacturing or operation and may consequently help improve these processes. Additionally, positioning can provide insight into the physics of vacuum arcs. In this work, two established positioning methods based on the time-difference-ofarrival of radio frequency waves are extended. The first method i...

  2. RF Accelerating Structure for the Muon Cooling Experiment

    International Nuclear Information System (INIS)

    Corlett, J.; Green, M.; Li, D.; Holtkamp, N.; Moretti, A.; Kirk, H. G.; Palmer, R. B.; Zhao, Y.; Summers, D.

    1999-01-01

    The ionization cooling of muons requires longitudinal acceleration of the muons after scattering in a hydrogen target. In order to maximize the accelerating voltage, they propose using linear accelerating structures with cells bounded by thin beryllium metal foils. this produces an on-axis field equivalent to the maximum surface field, whereas with beam-pipes the accelerating field is approximately half that of the peak surface field in the cavity. The muons interact only weakly with the thin foils. A π/2 interleaved cavity structure has been chosen, with alternate cells coupled together externally, and the two groups of cells fed in quadrature. At present they are considering an operating temperature of 77K to gain a factor of at least two in Q-value over room temperature. They will describe the design of the π/2 interleaved cavity structure, design of an alternative π-mode open structure, preliminary experimental results from a low-power test cavity, and plans for high-power testing

  3. Calculation of coupling factor for double-period accelerating structure

    International Nuclear Information System (INIS)

    Bian Xiaohao; Chen Huaibi; Zheng Shuxin

    2005-01-01

    In the design of the linear accelerating structure, the coupling factor between cavities is a crucial parameter. The error of coupling factor accounts for the electric or magnetic field error mainly. To accurately design the coupling iris, the accurate calculation of coupling factor is essential. The numerical simulation is widely used to calculate the coupling factor now. By using MAFIA code, two methods have been applied to calculate the dispersion characteristics of the single-period structure, one method is to simulate the traveling wave mode by the period boundary condition; another method is to simulate the standing wave mode by the electrical boundary condition. In this work, the authors develop the two methods to calculate the coupling factor of double-period accelerating structure. Compared to experiment, the results for both methods are very similar, and in agreement with measurement within 15% deviation. (authors)

  4. High gradient tests of SLAC Linear Collider Accelerator Structures

    International Nuclear Information System (INIS)

    Wang, J.W.; Deruyter, H.; Eichner, J.; Fant, K.H.; Hoag, H.A.; Koontz, R.F.; Lavine, T.; Loew, G.A.; Loewen, R.; Menegat, L.

    1994-08-01

    This paper describes the current SLAC R ampersand D program to develop room temperature accelerator structures for the Next Linear Collider (NLC). The structures are designed to operate at 11.4 GHz at an accelerating gradient in the range of 50 to 100 MV/m. In the past year a 26 cm constant-impedance traveling-wave section, a 75 cm constant-impedance traveling-wave section, and a 1.8 m traveling-wave section with detuned deflecting modes have been high-power tested. The paper presents a brief description of the RF test setup, the design and manufacturing details of the structures, and a discussion of test results including field emission, RF processing, dark current spectrum and RF breakdown

  5. Design of an electrostatic magnetic quadrupole accelerator

    International Nuclear Information System (INIS)

    Mizuno, M.; Ohara, Y.

    1993-01-01

    A new type of electrostatic acceleration system, electrostatic magnetic quadrupole (ESMQ) acceleration system, is proposed for efficient acceleration of negative ion beams. In this system, permanent magnets are buried in the acceleration electrodes so as to produce a quadrupole magnetic field in the electrode aperture region. Envelope simulation indicates that the quadrupole field can deflect electrons stripped from the negative ions. Beam envelope simulations for deuterium ions and electrons have been carried out using the beam envelope code TRACE. Electrons are largely divergent and most appear likely to hit downstream electrodes. Furthermore, maximum beam divergence of the deuterium ions is reduced to the focusing effect of the quadrupole magnetic field

  6. Advanced accelerator and mm-wave structure research at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Simakov, Evgenya Ivanovna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-22

    This document outlines acceleration projects and mm-wave structure research performed at LANL. The motivation for PBG research is described first, with reference to couplers for superconducting accelerators and structures for room-temperature accelerators and W-band TWTs. These topics are then taken up in greater detail: PBG structures and the MIT PBG accelerator; SRF PBG cavities at LANL; X-band PBG cavities at LANL; and W-band PBG TWT at LANL. The presentation concludes by describing other advanced accelerator projects: beam shaping with an Emittance Exchanger, diamond field emitter array cathodes, and additive manufacturing of novel accelerator structures.

  7. Modified PARMILA code for new accelerating structures

    International Nuclear Information System (INIS)

    Takeda, H.; Stovall, J.E.

    1995-01-01

    The PARMILA code was originally developed as a numerical tool to design and simulate the beam performance of the drift-tube linac (DTL). The authors have extended PARMILA to the design of both the coupled-cavity linac (CCL) and the coupled-cavity drift-tube linac (CCDTL). They describe the new design and simulation features associated with these linac structures and improvements to the code that facilitate a seamless linac design process

  8. Calculation and designing accelerator vacuum systems

    International Nuclear Information System (INIS)

    Glazkov, A.A.

    1984-01-01

    Construction of the vacuum system of any accelerator is determined by upper permissible pressure limit of resiidual gas in its chamber. Different effects resulting in worsening beam quality are considered. Minimum medium pressures in chambers and other vacuum parameters of the largest accelerators and storage rings are presented

  9. Design of a self-focusing linear electron accelerator

    International Nuclear Information System (INIS)

    Hddab, S.

    1983-06-01

    In this report we tackle the principal physical and technical problems related to the design of a self-focusing linear electron accelerator. The study of the dynamic phenomena occurring at the entrance to the first resonant cell allows us, by an adequate choice of the longitudinal height of this cell, to avoid the use of an external magnetic focusing coil. Optimization of the ultra high frequency properties of the resonant structure has been achieved by polishing the internal surfaces of the cavities, by adapting a new brazing technique and optimizing the geometry of the cells. A simulation code has been adapted to an interactive use on microcomputer [fr

  10. Design of a Microwave Assisted Discharge Inductive Plasma Accelerator

    Science.gov (United States)

    Hallock, Ashley K.; Polzin, Kurt A.

    2010-01-01

    The design and construction of a thruster that employs electrodeless plasma preionization and pulsed inductive acceleration is described. Preionization is achieved through an electron cyclotron resonance discharge that produces a weakly-ionized plasma at the face of a conical theta pinch-shaped inductive coil. The presence of the preionized plasma allows for current sheet formation at lower discharge voltages than those employed in other pulsed inductive accelerators that do not employ preionization. The location of the electron cyclotron resonance discharge is controlled through the design of the applied magnetic field in the thruster. Finite element analysis shows that there is an arrangement of permanent magnets that yields a small volume of resonant magnetic field at the coil face. Preionization in the resonant zone leads to current sheet formation at the coil face, which minimizes the initial inductance of the pulse circuit and maximizes the potential electrical efficiency of the accelerator. A magnet assembly was constructed around an inductive coil to provide structural support to the selected arrangement of neodymium magnets. Measured values of the resulting magnetic field compare favorably with the finite element model.

  11. Acceleration lane design for higher truck volumes.

    Science.gov (United States)

    2008-12-09

    The research project examined attributes associated with tractor-trailer trucks accelerating on freeway entry ramps and : entering the main traffic lanes. Data for this project were collected at five commercial vehicle weigh stations in : Arkansas an...

  12. Design of a nonscaling fixed field alternating gradient accelerator

    Directory of Open Access Journals (Sweden)

    D. Trbojevic

    2005-05-01

    Full Text Available We present a design of nonscaling fixed field alternating gradient accelerators (FFAG minimizing the dispersion action function H. The design is considered both analytically and via computer modeling. We present the basic principles of a nonscaling FFAG lattice and discuss optimization strategies so that one can accelerate over a broad range of momentum with reasonable apertures. Acceleration schemes for muons are discussed.

  13. The electron test accelerator safety in design and operation

    International Nuclear Information System (INIS)

    McKeown, J.

    1980-06-01

    The Electron Test Accelerator is being designed as an experiment in accelerator physics and technology. With an electron beam power of up to 200 kW the operation of the accelerator presents a severe radiation hazard as well as rf and electrical hazards. The design of the safety system provides fail-safe protection while permitting flexibility in the mode of operation and minimizing administrative controls. (auth)

  14. The SPS acceleration system: travelling wave drift-tube structure for the CERN SPS

    International Nuclear Information System (INIS)

    Dome, G.

    1976-01-01

    The SPS accelerating structure is essentially a high energy proton linac, except for a small frequency swing during the acceleration cycle. It is operated almost CW with a travelling wave giving an energy gain around 0.1 MeV/m. The guide-lines for the design of such a structure are explained, and practical solutions are described. (author)

  15. A hybrid dielectric and iris loaded periodic accelerating structure

    International Nuclear Information System (INIS)

    Zou, P.; Xiao, L.; Sun, X.; Gai, W.

    2001-01-01

    One disadvantage of conventional iris-loaded accelerating structures is the high ratio of the peak surface electric field to the peak axial electric field useful for accelerating a beam. Typically this ratio E s /E a ≥ 2. The high surface electric field relative to the accelerating gradient may prove to be a limitation for realizing technologies for very high gradient accelerators. In this paper, we present a scheme that uses a hybrid dielectric and iris loaded periodic structure to reduce E s /E a to near unity, while the shunt impedance per unit length r and the quality factor Q compare favorably with conventional metallic structures. The analysis based on MAFIA simulations of such structures shows that we can lower the peak surface electric field close to the accelerating gradient while maintaining high acceleration efficiency as measured by r/Q. Numerical examples of X-band hybrid accelerating structures are given

  16. Power efficiency optimization of disk-loaded waveguide traveling wave structure of electron linear accelerator

    International Nuclear Information System (INIS)

    Yang Jinghe; Li Jinhai; Li Chunguang

    2014-01-01

    Disk-loaded waveguide traveling wave structure (TWS), which is widely used in scientific research and industry, is a vital accelerating structure in electron linear accelerator. The power efficiency is an important parameter for designing TWS, which greatly effects the expenses for the fabrication and commercial running. The key parameters related with power efficiency were studied for TWS optimization. The result was proved by experiment result, and it shows some help for accelerator engineering. (authors)

  17. Integrated Structural Design Education

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    2011-01-01

    In Environmental Impact Assessment (EIA), the environment is broadly defined and includes not only quantifiable aspects, but also social conditions, scenic beauty, traffic, cultural heritage, and commercial development. A successful bridge design must comply with all of these demands according...... landscaping and structural design. The integrated courses create a setting for learning about the design of large-scale structures and involve geometry, statics, computer simulation, graphical design and landscape architecture. Together, they educate engineers who can take part in the early design phases...... of a project, function well in design teams, and comply with EU EIA demands....

  18. Design of a plasma discharge circuit for particle wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Anania, M.P., E-mail: mpanania@lnf.infn.it [Istituto Nazionale di Fisica Nucleare, via Enrico Fermi 40, 00044 Frascati (Italy); Chiadroni, E. [Istituto Nazionale di Fisica Nucleare, via Enrico Fermi 40, 00044 Frascati (Italy); Cianchi, A. [Tor Vergata University, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Di Giovenale, D.; Ferrario, M. [Istituto Nazionale di Fisica Nucleare, via Enrico Fermi 40, 00044 Frascati (Italy); Flora, F.; Gallerano, G.P. [ENEA, via Enrico Fermi 45, 00044 Frascati (Italy); Ghigo, A. [Istituto Nazionale di Fisica Nucleare, via Enrico Fermi 40, 00044 Frascati (Italy); Marocchino, A.; Massimo, F.; Mostacci, A. [La Sapienza University, Piazzale Aldo Moro 2, 00185 Roma (Italy); Mezi, L. [ENEA, via Enrico Fermi 45, 00044 Frascati (Italy); Musumeci, P. [UCLA – University of California, Los Angeles, CA (United States); Serio, M. [Istituto Nazionale di Fisica Nucleare, via Enrico Fermi 40, 00044 Frascati (Italy)

    2014-03-11

    Plasma wakefield acceleration is the most promising acceleration technique known nowadays, able to provide very high accelerating fields (10–100 GV m{sup −1}), enabling acceleration of electrons to GeV energy in few centimetres. However, the quality of the electron bunches accelerated with this technique is still not comparable with that of conventional accelerators; radiofrequency-based accelerators, in fact, are limited in the accelerating field (10–100 MV m{sup −1}) requiring therefore kilometric distances to reach the GeV energies, but can provide very bright electron bunches. Combining high brightness electron bunches from conventional accelerators and high accelerating fields reachable with plasmas could be a good compromise allowing to further accelerate high brightness electron bunches coming from LINAC while preserving electron beam quality. Following the idea of plasma wave resonant excitation driven by a train of short bunches, we have started to study the requirements in terms of plasma for SPARC-LAB [1,2]. In particular, here we focus on the ionization process; we show a simplified model to study the evolution of plasma induced by discharge, very useful to design the discharge circuit able to fully ionize the gas and bring the plasma at the needed temperature and density.

  19. Accelerated Electron-Beam Formation with a High Capture Coefficient in a Parallel Coupled Accelerating Structure

    Science.gov (United States)

    Chernousov, Yu. D.; Shebolaev, I. V.; Ikryanov, I. M.

    2018-01-01

    An electron beam with a high (close to 100%) coefficient of electron capture into the regime of acceleration has been obtained in a linear electron accelerator based on a parallel coupled slow-wave structure, electron gun with microwave-controlled injection current, and permanent-magnet beam-focusing system. The high capture coefficient was due to the properties of the accelerating structure, beam-focusing system, and electron-injection system. Main characteristics of the proposed systems are presented.

  20. Status of the Neutrino Factory accelerator design studies

    CERN Document Server

    Prior, Gersende

    2013-01-01

    This document is a review of the present status of the Neutrino Factory design study, after the publication of the Interim Design Report and before the publication of the Reference Design Report. The different components of the accelerator as well as their current design stage and future tasks are described here.

  1. The fabrication of millimeter-wavelength accelerating structures

    International Nuclear Information System (INIS)

    Chou, P.J.; Bowden, G.B.; Copeland, M.R.

    1996-11-01

    There is a growing interest in the development of high gradient (≥ 1 GeV/m) accelerating structures. The need for high gradient acceleration based on current microwave technology requires the structures to be operated in the millimeter wavelength. Fabrication of accelerating structures at millimeter scale with sub-micron tolerances poses great challenges. The accelerating structures impose strict requirements on surface smoothness and finish to suppress field emission and multipactor effects. Various fabrication techniques based on conventional machining and micromachining have been evaluated and tested. These will be discussed and measurement results presented

  2. Simulation Studies of the Dielectric Grating as an Accelerating and Focusing Structure

    International Nuclear Information System (INIS)

    Soong, Ken; Peralta, E.A.; Byer, R.L.; Colby, E.

    2011-01-01

    A grating-based design is a promising candidate for a laser-driven dielectric accelerator. Through simulations, we show the merits of a readily fabricated grating structure as an accelerating component. Additionally, we show that with a small design perturbation, the accelerating component can be converted into a focusing structure. The understanding of these two components is critical in the successful development of any complete accelerator. The concept of accelerating electrons with the tremendous electric fields found in lasers has been proposed for decades. However, until recently the realization of such an accelerator was not technologically feasible. Recent advances in the semiconductor industry, as well as advances in laser technology, have now made laser-driven dielectric accelerators imminent. The grating-based accelerator is one proposed design for a dielectric laser-driven accelerator. This design, which was introduced by Plettner, consists of a pair of opposing transparent binary gratings, illustrated in Fig. 1. The teeth of the gratings serve as a phase mask, ensuring a phase synchronicity between the electromagnetic field and the moving particles. The current grating accelerator design has the drive laser incident perpendicular to the substrate, which poses a laser-structure alignment complication. The next iteration of grating structure fabrication seeks to monolithically create an array of grating structures by etching the grating's vacuum channel into a fused silica wafer. With this method it is possible to have the drive laser confined to the plane of the wafer, thus ensuring alignment of the laser-and-structure, the two grating halves, and subsequent accelerator components. There has been previous work using 2-dimensional finite difference time domain (2D-FDTD) calculations to evaluate the performance of the grating accelerator structure. However, this work approximates the grating as an infinite structure and does not accurately model a

  3. Design of four-beam IH-RFQ linear accelerator

    Science.gov (United States)

    Ikeda, Shota; Murata, Aki; Hayashizaki, Noriyosu

    2017-09-01

    The multi-beam acceleration method is an acceleration technique for low-energy high-intensity heavy ion beams, which involves accelerating multiple beams to decrease space charge effects, and then integrating these beams by a beam funneling system. At the Tokyo Institute of Technology a two beam IH-RFQ linear accelerator was developed using a two beam laser ion source with direct plasma injection scheme. This system accelerated a carbon ion beam with a current of 108 mA (54 mA/channel × 2) from 5 up to 60 keV/u. In order to demonstrate that a four-beam IH-RFQ linear accelerator is suitable for high-intensity heavy ion beam acceleration, we have been developing a four-beam prototype. A four-beam IH-RFQ linear accelerator consists of sixteen RFQ electrodes (4 × 4 set) with stem electrodes installed alternately on the upper and lower ridge electrodes. As a part of this development, we have designed a four-beam IH-RFQ linear accelerator using three dimensional electromagnetic simulation software and beam tracking simulation software. From these simulation results, we have designed the stem electrodes, the center plate and the side shells by evaluating the RF properties such as the resonance frequency, the power loss and the electric strength distribution between the RFQ electrodes.

  4. Design of modified safety interlock system for pelletron accelerator

    International Nuclear Information System (INIS)

    Yadav, M.L.; Lokare, R.N.; Matkar, U.V.; Ekambaram, M.; Gudekar, P.V.; Vishwakarma, Ramlal S.; Kulkarni, S.G.; Gore, J.A.; Gupta, A.K.; Datar, V.M.

    2013-01-01

    The BARC-TIFR Pelletron Accelerator Facility has been operational for last twenty four years progressively with increased efficiency, delivering energetic light and heavy ions at medium energy. The process of beam acceleration makes the accelerator tower and beam hall radiation prone areas. A modified Interlock system for Pelletron Accelerator has been designed and developed to ensure radiation safety of the personnel working in the accelerator premises. Radiation levels from monitors, status of search and secure switches and entry doors of the accelerator tower, are inputs to the interlock system. The system triggers if radiation level exceeds the set value or status of any search and secure switches and entry doors across the tower are changed, thus stopping the beam at ion source level. This system also incorporates new features like-audio visual alarm pertaining to each location. (author)

  5. LeRC rail accelerators: test designs and diagnostic techniques

    International Nuclear Information System (INIS)

    Zana, L.M.; Kerslake, W.R.; Sturman, J.C.; Wang, S.Y.; Terdan, F.F.

    1984-01-01

    The feasibility of using rail accelerators for various in-space and to-space propulsion applications was investigated. A 1 meter, 24 sq mm bore accelerator was designed with the goal of demonstrating projectile velocities of 15 km/sec using a peak current of 200 kA. A second rail accelerator, 1 meter long with a 156.25 sq mm bore, was designed with clear polycarbonate sidewalls to permit visual observation of the plasma arc. A study of available diagnostic techniques and their application to the rail accelerator is presented. Specific topics of discussion include the use of interferometry and spectroscopy to examine the plasma armature as well as the use of optical sensors to measure rail displacement during acceleration. Standard diagnostics such as current and voltage measurements are also discussed. 15 references

  6. Heating of microprotrusions in accelerating structures

    Directory of Open Access Journals (Sweden)

    A. C. Keser

    2013-09-01

    Full Text Available The thermal and field emission of electrons from protrusions on metal surfaces is a possible limiting factor on the performance and operation of high-gradient room temperature accelerator structures. We present here the results of extensive numerical simulations of electrical and thermal behavior of protrusions. We unify the thermal and field emission in the same numerical framework, describe bounds for the emission current and geometric enhancement, then we calculate the Nottingham and Joule heating terms and solve the heat equation to characterize the thermal evolution of emitters under rf electric field. Our findings suggest that heating is entirely due to the Nottingham effect. The time dependence of the rf field leads to a time dependent tip temperature with excursion that depends weakly on rf frequency. We build a phenomenological model to account for the effect of space charge and show that space charge eliminates the possibility of copper tip melting for tips with radii less than 10  μm with vacuum fields on their surface less than 12  GV/m, and for rf frequencies above 1 GHz.

  7. On the structure of acceleration in turbulence

    DEFF Research Database (Denmark)

    Liberzon, A.; Lüthi, B.; Holzner, M.

    2012-01-01

    Acceleration and spatial velocity gradients are obtained simultaneously in an isotropic turbulent flow via three dimensional particle tracking velocimetry. We observe two distinct populations of intense acceleration events: one in flow regions of strong strain and another in regions of strong...... vorticity. Geometrical alignments with respect to vorticity vector and to the strain eigenvectors, curvature of Lagrangian trajectories and of streamlines for total acceleration, and for its convective part, , are studied in detail. We discriminate the alignment features of total and convective acceleration...... statistics, which are genuine features of turbulent nature from those of kinematic nature. We find pronounced alignment of acceleration with vorticity. Similarly, and especially are predominantly aligned at 45°with the most stretching and compressing eigenvectors of the rate of the strain tensor...

  8. STRUCTURAL ANALYSIS OF SUPERCONDUCTING ACCELERATOR CAVITIES

    International Nuclear Information System (INIS)

    Schrage, D.

    2000-01-01

    The static and dynamic structural behavior of superconducting cavities for various projects was determined by finite element structural analysis. The β = 0.61 cavity shape for the Neutron Science Project was studied in detail and found to meet all design requirements if fabricated from five millimeter thick material with a single annular stiffener. This 600 MHz cavity will have a Lorentz coefficient of minus1.8 Hz/(Mv/meter) 2 and a lowest structural resonance of more than 100 Hz. Cavities at β = 0.48, 0.61, and 0.77 were analyzed for a Neutron Science Project concept which would incorporate 7-cell cavities. The medium and high beta cavities were found to meet all criteria but it was not possible to generate a β = 0.48 cavity with a Lorentz coefficient of less than minus3 Hz/(Mv/meter) 2

  9. Design of a 1 MeV 3He+ RFQ for the SAIC PET accelerator facility

    International Nuclear Information System (INIS)

    Cornelius, W.D.; Young, P.E.

    1993-01-01

    The novel design of a 1 MeV 3 He + radiofrequency quadrupole (RFQ) accelerator is discussed. This RFQ is the first segment of an accelerator for the production of radioisotopes for positron emission tomography (PET) applications. This RFQ is unusual in that two specific innovations were incorporated into the design. The mechanical design is a hybrid of conventional four-vane and four-rod geometries. This hybridization reduces the physical dimensions of the accelerator without sacrificing too much in rf efficiency and has the added benefit of reducing the sensitivity to mechanical alignment errors. In addition, the beam dynamics of the last few cells was modified to tailor the output beam parameters to improve the beam transport through the next accelerator section. The details of the mechanical structure, the mechanical and electrical alignment experiences, and a comparison of the theoretical and experimental performance of this accelerator are also discussed. (orig.)

  10. Coupler tuning for constant gradient travelling wave accelerating structures

    International Nuclear Information System (INIS)

    Guo Xingkun; Ma Yanyun; Wang Xiulong

    2013-01-01

    The method of the coupler tuning for the constant gradient traveling wave accelerating structure was described and the formula of coupling coefficient p was deduced on the basis of analyzing the existing methods for the constant impedance traveling wave accelerating structures and coupling-cavity chain equivalent circuits. The method and formula were validated by the simulation result by CST and experiment data. (authors)

  11. Reliability based structural design

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2013-01-01

    According to ISO 2394, structures shall be designed, constructed and maintained in such a way that they are suited for their use during the design working life in an economic way. To fulfil this requirement one needs insight into the risk and reliability under expected and non-expected actions. A

  12. Safety in design and operation of low energy particle accelerators

    International Nuclear Information System (INIS)

    Badawy, I.

    1991-01-01

    This paper studies the safety in design and operation of low energy accelerators which produce beams of accelerated charged particles and radiations. As radiation sources, the accelerators are widely used in scientific research, industry, food and medical applications. The risks to human and environment are considered. The safety in accelerators is discussed-particularly-the shielding against ionizing radiations, overexposure to RF radiation fire hazards and power failures. Also the paper studies the emergency response at incidents. Emergency procedures are recommended for each type of emergency. Reporting to the competent Authority is also recommended to be prepared for each incident. The basic principles of regulatory control, licensing and inspections for accelerator facilities are discussed. The relation with the competent authority is pointed out. 4 fig

  13. Design of MEMS accelerometer based acceleration measurement system for automobiles

    Science.gov (United States)

    Venkatesh, K. Arun; Mathivanan, N.

    2012-10-01

    Design of an acceleration measurement system using a MEMS accelerometer to measure acceleration of automobiles in all the three axes is presented. Electronic stability control and anti-lock breaking systems in automobiles use the acceleration measurements to offer safety in driving. The system uses an ARM microcontroller to quantize the outputs of accelerometer and save the measurement data on a microSD card. A LabVIEW program has been developed to analyze the longitudinal acceleration measurement data and test the measurement system. Random noises generated and added with measurement data during measurement are filtered by a Kalman filter implemented in LabVIEW. Longitudinal velocity of the vehicle is computed from the measurement data and displayed on a graphical chart. Typical measurement of velocity of a vehicle at different accelerations and decelerations is presented.

  14. Structural elements design manual

    CERN Document Server

    Draycott, Trevor

    2012-01-01

    Gives clear explanations of the logical design sequence for structural elements. The Structural Engineer says: `The book explains, in simple terms, and with many examples, Code of Practice methods for sizing structural sections in timber, concrete,masonry and steel. It is the combination into one book of section sizing methods in each of these materials that makes this text so useful....Students will find this an essential support text to the Codes of Practice in their study of element sizing'.

  15. Design and fabrication of a Transverse Field Focussing (TFF) 180 keV negative ion accelerator

    International Nuclear Information System (INIS)

    Matuk, C.A.; Anderson, O.A.; Owren, H.M.; Paterson, J.A.; Purgalis, P.

    1985-11-01

    The 180 keV Transverse Field Focussing (TFF) negative ion accelerator described is the final component of a negative ion based neutral beam acceleration system which is being developed as proof-of-principle demonstration of a radiation hardened neutral beamline. The 180 keV beamline consists of: a surface conversion negative ion source, a 80 keV pre-accelerator, a TFF pumping, matching, and transport section, and the 180 keV TFF accelerator presented. This beamline is expected to provide 1 A of H - at 180 keV. In the design of the accelerator, particular importance was given to the rigidity of the accelerator electrode mounting structures and to the electrical isolation of the electrodes along with their related cooling lines. An optical alignment scheme was developed to assemble and to insure precision alignment of the electrodes

  16. Accelerator technical design report for high-intensity proton accelerator facility project, J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    This report presents the detail of the technical design of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. The accelerator complex comprises a 400-MeV room-temperature linac (600-MeV superconducting linac), 3-GeV rapid-cycling synchrotron (RCS), and a 50-GeV synchrotron (MR). The 400-MeV beam is injected to the RCS, being accelerated to 3 GEV. The 1-MW beam thus produced is guided to the Materials Life Science Experimental Facility, with both the pulsed spallation neutron source and muon source. A part of the beam is transported to the MR, which provides the 0.75-MW beam to either the Nuclear and Fundamental Particle Experimental Facility or the Neutrino Production Target. On the other hand, the beam accelerated to 600 MeV by the superconducting linac is used for the Nuclear Waster Transmutation Experiment. In this way, this facility is unique, being multipurpose one, including many new inventions and Research and Development Results. This report is based upon the accomplishments made by the Accelerator Group and others of the Project Team, which is organized on the basis of the Agreement between JAERI and KEK on the Construction and Research and Development of the High-Intensity Proton Accelerator Facility. (author)

  17. Operational and design aspects of accelerators for medical applications

    OpenAIRE

    Jacobus Maarten Schippers; Mike Seidel

    2015-01-01

    Originally, the typical particle accelerators as well as their associated beam transport equipment were designed for particle and nuclear physics research and applications in isotope production. In the past few decades, such accelerators and related equipment have also been applied for medical use. This can be in the original physics laboratory environment, but for the past 20 years also in hospital-based or purely clinical environments for particle therapy. The most important specific requir...

  18. Cell design for the DARHT linear induction accelerators

    International Nuclear Information System (INIS)

    Burns, M.; Allison, P.; Earley, L.; Liska, D.; Mockler, C.; Ruhe, J.; Tucker, H.; Walling, L.

    1991-01-01

    The Dual-Axis Radiographic Hydrotest (DARHT) facility will employ two linear induction accelerators to produce intense, bremsstrahlung x- ray pulses for flash radiography. The accelerator cell design for a 3- kA, 16--20 MeV, 60-ns flattop, high-brightness electron beam is presented. The cell is optimized for high-voltage stand-off while also minimizing the its transverse impedance. Measurements of high- voltage and rf characteristics are summarized. 7 refs., 5 figs

  19. Optics modules for circular accelerator design

    International Nuclear Information System (INIS)

    Brown, K.L.; Servranckx, R.V.

    1986-05-01

    The first-order differential equations of motion for a single particle in a closed circular machine are solved, introducing the concepts of phase shift, beta functions, and the Courant-Snyder invariant. The transfer matrix between two points in the machine is derived as a function of the phase shift and the parameters contained in the Courant-Snyder invariant. Typical optical modules used in circular machine designs are introduced and related to their characteristic transfer matrix elements, the phase shift through them, and the Courant-Snyder-Twiss parameters. The systematics of some elementary phase ellipse matching problems between optical modules are discussed. Second-order optical modules are discussed, including how they are used to provide the momentum bandwidth needed for the design of a typical circular machine

  20. High gradient tests of metallic mm-wave accelerating structures

    Science.gov (United States)

    Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon; Clarke, Christine; Hogan, Mark; McCormick, Doug; Novokhatski, Alexander; O'Shea, Brendan; Spataro, Bruno; Weathersby, Stephen; Tantawi, Sami G.

    2017-08-01

    This paper explores the physics of vacuum rf breakdowns in high gradient mm-wave accelerating structures. We performed a series of experiments with 100 GHz and 200 GHz metallic accelerating structures, at the Facility for Advanced Accelerator Experimental Tests (FACET) at the SLAC National Accelerator Laboratory. This paper presents the experimental results of rf tests of 100 GHz travelling-wave accelerating structures, made of hard copper-silver alloy. The results are compared with pure hard copper structures. The rf fields were excited by the FACET ultra-relativistic electron beam. The accelerating structures have open geometries, 10 cm long, composed of two halves separated by a variable gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changed from 90 GHz to 140 GHz. The measured frequency and pulse length are consistent with our simulations. When the beam travels off-axis, a deflecting field is induced in addition to the decelerating longitudinal field. We measured the deflecting forces by observing the displacement of the electron bunch and used this measurement to verify the expected accelerating gradient. We present the first quantitative measurement of rf breakdown rates in 100 GHz copper-silver accelerating structure, which was 10-3 per pulse, with peak electric field of 0.42 GV/m, an accelerating gradient of 127 MV/m, at a pulse length of 2.3 ns. The goal of our studies is to understand the physics of gradient limitations in order to increase the energy reach of future accelerators.

  1. The design and commissioning of large particle accelerators

    International Nuclear Information System (INIS)

    Wilson, E.J.N.

    1981-01-01

    The design and development of synchrotrons and storage rings for proton and electron acceleration are discussed. Having traced the evolution of designs from those for the early cyclotrons, the present generation of synchrotrons are described and the running in of such component systems is considered. (U.K.)

  2. Dielectric laser acceleration of non-relativistic electrons at a photonic structure

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, John

    2013-08-29

    This thesis reports on the observation of dielectric laser acceleration of non-relativistic electrons via the inverse Smith-Purcell effect in the optical regime. Evanescent modes in the vicinity of a periodic grating structure can travel at the same velocity as the electrons along the grating surface. A longitudinal electric field component is used to continuously impart momentum onto the electrons. This is only possible in the near-field of a suitable photonic structure, which means that the electron beam has to pass the structure within about one wavelength. In our experiment we exploit the third spatial harmonic of a single fused silica grating excited by laser pulses derived from a Titanium:sapphire oscillator and accelerate non-relativistic 28 keV electrons. We measure a maximum energy gain of 280 eV, corresponding to an acceleration gradient of 25 MeV/m, already comparable with state-of-the-art radio-frequency linear accelerators. To experience this acceleration gradient the electrons approach the grating closer than 100 nm. We present the theory behind grating-based particle acceleration and discuss simulation results of dielectric laser acceleration in the near-field of photonic grating structures, which is excited by near-infrared laser light. Our measurements show excellent agreement with our simulation results and therefore confirm the direct acceleration with the light field. We further discuss the acceleration inside double grating structures, dephasing effects of non-relativistic electrons as well as the space charge effect, which can limit the attainable peak currents of these novel accelerator structures. The photonic structures described in this work can be readily concatenated and therefore represent a scalable realization of dielectric laser acceleration. Furthermore, our structures are directly compatible with the microstructures used for the acceleration of relativistic electrons demonstrated in parallel to this work by our collaborators in

  3. Dielectric laser acceleration of non-relativistic electrons at a photonic structure

    International Nuclear Information System (INIS)

    Breuer, John

    2013-01-01

    This thesis reports on the observation of dielectric laser acceleration of non-relativistic electrons via the inverse Smith-Purcell effect in the optical regime. Evanescent modes in the vicinity of a periodic grating structure can travel at the same velocity as the electrons along the grating surface. A longitudinal electric field component is used to continuously impart momentum onto the electrons. This is only possible in the near-field of a suitable photonic structure, which means that the electron beam has to pass the structure within about one wavelength. In our experiment we exploit the third spatial harmonic of a single fused silica grating excited by laser pulses derived from a Titanium:sapphire oscillator and accelerate non-relativistic 28 keV electrons. We measure a maximum energy gain of 280 eV, corresponding to an acceleration gradient of 25 MeV/m, already comparable with state-of-the-art radio-frequency linear accelerators. To experience this acceleration gradient the electrons approach the grating closer than 100 nm. We present the theory behind grating-based particle acceleration and discuss simulation results of dielectric laser acceleration in the near-field of photonic grating structures, which is excited by near-infrared laser light. Our measurements show excellent agreement with our simulation results and therefore confirm the direct acceleration with the light field. We further discuss the acceleration inside double grating structures, dephasing effects of non-relativistic electrons as well as the space charge effect, which can limit the attainable peak currents of these novel accelerator structures. The photonic structures described in this work can be readily concatenated and therefore represent a scalable realization of dielectric laser acceleration. Furthermore, our structures are directly compatible with the microstructures used for the acceleration of relativistic electrons demonstrated in parallel to this work by our collaborators in

  4. Multipactor Physics, Acceleration, and Breakdown in Dielectric-Loaded Accelerating Structures

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Richard P. [Naval Research Lab., Washington, DC (United States); Gold, Steven H. [Naval Research Lab., Washington, DC (United States)

    2016-07-01

    The objective of this 3-year program is to study the physics issues associated with rf acceleration in dielectric-loaded accelerating (DLA) structures, with a focus on the key issue of multipactor loading, which has been found to cause very significant rf power loss in DLA structures whenever the rf pulsewidth exceeds the multipactor risetime (~10 ns). The experiments are carried out in the X-band magnicon laboratory at the Naval Research Laboratory (NRL) in collaboration with Argonne National Laboratory (ANL) and Euclid Techlabs LLC, who develop the test structures with support from the DoE SBIR program. There are two main elements in the research program: (1) high-power tests of DLA structures using the magnicon output (20 MW @11.4 GHz), and (2) tests of electron acceleration in DLA structures using relativistic electrons from a compact X-band accelerator. The work during this period has focused on a study of the use of an axial magnetic field to suppress multipactor in DLA structures, with several new high power tests carried out at NRL, and on preparation of the accelerator for the electron acceleration experiments.

  5. Design bases - Concrete structures

    International Nuclear Information System (INIS)

    Diaz-Llanos Ros, M.

    1993-01-01

    The most suitable title for Section 2 is 'Design Bases', which covers not only calculation but also the following areas: - Structural design concepts. - Project criteria. - Material specifications. These concepts are developed in more detail in the following sections. The numbering in this document is neither complete nor hierarchical since, for easier cross referencing, it corresponds to the paragraphs of Eurocode 2 Part 1 (hereinafter 'EUR-2') which are commented on. (author)

  6. Design of Octupole Channel for Integrable Optics Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, Sergey [Chicago U.; Carlson, Kermit [Fermilab; Castellotti, Riccardo [Unlisted, IT; Valishev, Alexander [Fermilab; Wesseln, Steven [Fermilab

    2016-06-01

    We present the design of octupole channel for Integrable Optics Test Accelerator (IOTA). IOTA is a test accelerator at Fermilab, aimed to conduct research towards high-intensity machines. One of the goals of the project is to demonstrate high nonlinear betatron tune shifts while retaining large dynamic aperture in a realistic accelerator design. At the first stage the tune shift will be attained with a special channel of octupoles, which creates a variable octupole potential over a 1.8 m length. The channel consists of 18 identical air-cooled octupole magnets. The magnets feature a simple low-cost design, while meeting the requirements on maximum gradient - up to 1.4 kG/cm³, and field quality - strength of harmonics below 1%. Numerical simulations show that the channel is capable of producing a nonlinear tune shift of 0.08 without restriction of dynamic aperture of the ring.

  7. High-gradient two-beam accelerator structure

    Directory of Open Access Journals (Sweden)

    S. Yu Kazakov

    2010-07-01

    Full Text Available A novel cavity structure is described that could be the basis for a two-beam, high-gradient, accelerator. Versions of the structure could be used for acceleration of beams of electrons, positrons, muons, protons, or heavier ions; with either electron or proton drive beams. The structure embodies cavities that are excited in several harmonically related eigenmodes, such that rf fields reach their peak values only during small portions of each basic rf period. This feature could help raise breakdown and pulse heating thresholds. The two-beam accelerator structure comprises chains of these cavities. In this configuration, no transfer elements are needed to couple rf energy from the drive beam to the accelerated beam, since both beams traverse the same cavities. Purposeful cavity detuning is used to provide much smaller deceleration for a high-current drive beam, than acceleration for a low-current accelerated beam, i.e., to provide a high transformer ratio. A self-consistent theory is presented to calculate idealized acceleration gradient, transformer ratio, and efficiency for energy transfer from the drive beam to the accelerated beam, for either parallel or antiparallel motion of the beams. The theory has been cast in dimensionless quantities so as to facilitate optimization with respect to efficiency, acceleration gradient, or transformer ratio, and to illuminate the interdependence of these parameters. Means for dramatically shortening the structure fill time are also described. However, no beam dynamics analysis is presented, so the range of parameters within which this new acceleration concept can be used will remain uncertain until it is established that stable beam transport along the structure using an appropriate focusing system is possible.

  8. Novel target design for enhanced laser driven proton acceleration

    Directory of Open Access Journals (Sweden)

    Malay Dalui

    2017-09-01

    Full Text Available We demonstrate a simple method of preparing structured target for enhanced laser-driven proton acceleration under target-normal-sheath-acceleration scheme. A few layers of genetically modified, clinically grown micron sized E. Coli bacteria cell coated on a thin metal foil has resulted in an increase in the maximum proton energy by about 1.5 times and the total proton yield is enhanced by approximately 25 times compared to an unstructured reference foil at a laser intensity of 1019 W/cm2. Particle-in-cell simulations on the system shows that the structures on the target-foil facilitates anharmonic resonance, contributing to enhanced hot electron production which leads to stronger accelerating field. The effect is observed to grow as the number of structures is increased in the focal area of the laser pulse.

  9. Accelerating Dielectrics Design Using Thinking Machines

    Science.gov (United States)

    Ramprasad, R.

    2013-03-01

    High energy density capacitors are required for several pulsed power and energy storage applications, including food preservation, nuclear test simulations, electric propulsion of ships and hybrid electric vehicles. The maximum electrostatic energy that can be stored in a capacitor dielectric is proportional to its dielectric constant and the square of its breakdown field. The current standard material for capacitive energy storage is polypropylene which has a large breakdown field but low dielectric constant. We are involved in a search for new classes of polymers superior to polypropylene using first principles computations combined with statistical and machine learning methods. Essential to this search are schemes to efficiently compute the dielectric constant of polymers and the intrinsic dielectric breakdown field, as well as methods to determine the stable structures of new classes of polymers and strategies to efficiently navigate through the polymer chemical space offered by the periodic table. These methodologies have been combined with statistical learning paradigms in order to make property predictions rapidly, and promising classes of polymeric systems for energy storage applications have been identified. This work is being supported by the Office of Naval Research.

  10. Bridgescaping - Contextual Structural Design

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    2011-01-01

    Large-scale infrastructural projects such as bridges used to be the monopoly of engineers. They were designed as – often very beautiful – expressions of how forces work in a structure, guided by the nature of materials and a rational construction process. However, in recent decades politicians...

  11. The International Linear Collider Technical Design Report - Volume 3.II: Accelerator Baseline Design

    CERN Document Server

    Adolphsen, Chris; Barish, Barry; Buesser, Karsten; Burrows, Philip; Carwardine, John; Clark, Jeffrey; Durand, Helene Mainaud; Dugan, Gerry; Elsen, Eckhard; Enomoto, Atsushi; Foster, Brian; Fukuda, Shigeki; Gai, Wei; Gastal, Martin; Geng, Rongli; Ginsburg, Camille; Guiducci, Susanna; Harrison, Mike; Hayano, Hitoshi; Kershaw, Keith; Kubo, Kiyoshi; Kuchler, Victor; List, Benno; Liu, Wanming; Michizono, Shinichiro; Nantista, Christopher; Osborne, John; Palmer, Mark; Paterson, James McEwan; Peterson, Thomas; Phinney, Nan; Pierini, Paolo; Ross, Marc; Rubin, David; Seryi, Andrei; Sheppard, John; Solyak, Nikolay; Stapnes, Steinar; Tauchi, Toshiaki; Toge, Nobu; Walker, Nicholas; Yamamoto, Akira; Yokoya, Kaoru

    2013-01-01

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to incr...

  12. The International Linear Collider Technical Design Report - Volume 3.I: Accelerator \\& in the Technical Design Phase

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, Chris [SLAC National Accelerator Lab., Menlo Park, CA (United States); et al.

    2013-06-26

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to increase significantly our understanding of the fundamental processes that govern the evolution of the Universe.

  13. The International Linear Collider Technical Design Report - Volume 3.II: Accelerator Baseline Design

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, Chris [SLAC National Accelerator Lab., Menlo Park, CA (United States); et al.

    2013-06-26

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to increase significantly our understanding of the fundamental processes that govern the evolution of the Universe.

  14. Operational and design aspects of accelerators for medical applications

    Directory of Open Access Journals (Sweden)

    Jacobus Maarten Schippers

    2015-03-01

    Full Text Available Originally, the typical particle accelerators as well as their associated beam transport equipment were designed for particle and nuclear physics research and applications in isotope production. In the past few decades, such accelerators and related equipment have also been applied for medical use. This can be in the original physics laboratory environment, but for the past 20 years also in hospital-based or purely clinical environments for particle therapy. The most important specific requirements of accelerators for radiation therapy with protons or ions will be discussed. The focus will be on accelerator design, operational, and formal aspects. We will discuss the special requirements to reach a high reliability for patient treatments as well as an accurate delivery of the dose at the correct position in the patient using modern techniques like pencil beam scanning. It will be shown that the technical requirements, safety aspects, and required reliability of the accelerated beam differ substantially from those in a nuclear physics laboratory. It will be shown that this difference has significant implications on the safety and interlock systems. The operation of such a medical facility should be possible by nonaccelerator specialists at different operating sites (treatment rooms. The organization and role of the control and interlock systems can be considered as being the most crucially important issue, and therefore a special, dedicated design is absolutely necessary in a facility providing particle therapy.

  15. Design and simulation of an accelerating and focusing system

    Directory of Open Access Journals (Sweden)

    A Sadeghipanah

    2011-06-01

    Full Text Available Electrostatic focusing lenses have a vast field of applications in electrostatic accelerators and particularly in electron guns. In this paper, we first express a parametric mathematical analysis of an electrostatic accelerator and focusing system for an electron beam. Next, we At design a system of electron emission slit, accelerating electrodes and focusing lens for an electron beam emitted from a cathode with 4 mm radius and 2 mA current, in a distance less than 10 cm and up to the energy of 30 keV with the beam divergence less than 5°. This is achieved by solving the yielded equations in mathematical analysis using MATLAB. At the end, we simulate the behavior of above electron beam in the designed accelerating and focusing system using CST EM Studio. The results of simulation are in high agreement with required specifications of the electron beam, showing the accuracy of the used method in analysis and design of the accelerating and focusing system.

  16. Operational and design aspects of accelerators for medical applications

    Science.gov (United States)

    Schippers, Jacobus Maarten; Seidel, Mike

    2015-03-01

    Originally, the typical particle accelerators as well as their associated beam transport equipment were designed for particle and nuclear physics research and applications in isotope production. In the past few decades, such accelerators and related equipment have also been applied for medical use. This can be in the original physics laboratory environment, but for the past 20 years also in hospital-based or purely clinical environments for particle therapy. The most important specific requirements of accelerators for radiation therapy with protons or ions will be discussed. The focus will be on accelerator design, operational, and formal aspects. We will discuss the special requirements to reach a high reliability for patient treatments as well as an accurate delivery of the dose at the correct position in the patient using modern techniques like pencil beam scanning. It will be shown that the technical requirements, safety aspects, and required reliability of the accelerated beam differ substantially from those in a nuclear physics laboratory. It will be shown that this difference has significant implications on the safety and interlock systems. The operation of such a medical facility should be possible by nonaccelerator specialists at different operating sites (treatment rooms). The organization and role of the control and interlock systems can be considered as being the most crucially important issue, and therefore a special, dedicated design is absolutely necessary in a facility providing particle therapy.

  17. Conceptual design of a commercial accelerator driven thorium reactor

    International Nuclear Information System (INIS)

    Fuller, C. G.; Ashworth, R. W.

    2010-01-01

    This paper describes the substantial work done in underpinning and developing the concept design for a commercial 600 MWe, accelerator driven, thorium fuelled, lead cooled, power producing, fast reactor. The Accelerator Driven Thorium Reactor (ADTR TM) has been derived from original work by Carlo Rubbia. Over the period 2007 to 2009 Aker Solutions commissioned this concept design work and, in close collaboration with Rubbia, developed the physics, engineering and business model. Much has been published about the Energy Amplifier concept and accelerator driven systems. This paper concentrates on the unique physics developed during the concept study of the ADTR TM power station and the progress made in engineering and design of the system. Particular attention is paid to where the concept design has moved significantly beyond published material. Description of challenges presented for the engineering and safety of a commercial system and how they will be addressed is included. This covers the defining system parameters, accelerator sizing, core and fuel design issues and, perhaps most importantly, reactivity control. The paper concludes that the work undertaken supports the technical viability of the ADTR TM power station. Several unique features of the reactor mean that it can be deployed in countries with aspirations to gain benefit from nuclear power and, at 600 MWe, it fits a size gap for less mature grid systems. It can provide a useful complement to Generation III, III+ and IV systems through its ability to consume actinides whilst at the same time providing useful power. (authors)

  18. Pulse line ion accelerator based design for the neutralized drift chamber experiment

    Science.gov (United States)

    Ling, C. Y.; Yu, S. S.; Henestroza, E.; Grote, D. P.; Friedman, A.

    2009-04-01

    The pulse line ion accelerator (PLIA) is a promising approach to accelerating heavy ion beams to regimes of interest for the study of high energy density physics (HEDP) and warm dense matter in a cost effective way. In this paper we demonstrate a PLIA-based design for a proposed HEDP machine, the neutralized drift compression experiment II. The simulation results from the injector to the exit of the accelerator using the particle-in-cell code WARP are presented. We show how the traveling wave structure of PLIA suggests straightforward strategies in controlling the longitudinal and transverse dynamics of the ion beam.

  19. Physical design of 9 MeV travelling wave electron linac accelerating tube

    International Nuclear Information System (INIS)

    Chen Huaibi; Ding Xiaodong; Lin Yuzheng

    2000-01-01

    An accelerating tube is described. It is a part of an accelerator used for inspection of vehicle cargoes in rail cars, trucks, shipping containers, or airplanes in customs. A klystron with power of 4 MW and frequency of 2856 MHz will be applied to supply microwave power. The electrons can be accelerated by a travelling wave in the accelerating tube about 220 cm long, with a buncher whose capture efficiency is more than 80%. Energy of electrons after travelling through the tube can reach 9 MeV (pulse current intensity 170 mA) or 6 MeV (pulse current intensity 300 mA). Physical design of the accelerating tube, including the calculations of longitudinal particle dynamics, structure parameter and working character is carried out

  20. Facilitating an accelerated experience-based co-design project.

    Science.gov (United States)

    Tollyfield, Ruth

    This article describes an accelerated experience-based co-design (AEBCD) quality improvement project that was undertaken in an adult critical care setting and the facilitation of that process. In doing so the aim is to encourage other clinical settings to engage with their patients, carers and staff alike and undertake their own quality improvement project. Patient, carer and staff experience and its place in the quality sphere is outlined and the importance of capturing patient, carer and staff feedback established. Experience-based co-design (EBCD) is described along with the recently tested accelerated version of the process. An overview of the project and outline of the organisational tasks and activities undertaken by the facilitator are given. The facilitation of the process and key outcomes are discussed and reflected on. Recommendations for future undertakings of the accelerated process are given and conclusions drawn.

  1. Accelerator design and construction in the 1950s

    International Nuclear Information System (INIS)

    Blewett, J.P.

    1989-01-01

    This article looks into the history of the design, construction and operation of four of the large particle accelerators of the 1950s, the Cosmotron and more powerful alternating-gradient synchrotron (AGS) at Brookhaven, the Bevatron at Berkeley and the CERN proton synchrotron in Geneva with which the author was involved. The author's own contribution was in magnet design for the Cosmotron and the radiofrequency accelerating system. He later worked on linear accelerators and strong focusing later used in the AGS with Nick Christofilos from Athens. Collaboration between CERN and Brookhaven continued following a British study of alternating-gradient focusing which showed up possible resonance problems. In 1953, the ''phase transition'' problem was overcome. The author's personal contribution to the AGS project completes the article. (UK)

  2. Design and construction of tetrode tube modulator for high power electron accelerator

    Directory of Open Access Journals (Sweden)

    A M Poursaleh

    2015-09-01

    Full Text Available In this paper, a high power tetrode tube (TH781-200kW, cw modulator is designed and implemented. This modulator is used for a part of RF system of the first Iranian high power electron accelerator project with similar structure to Rhodotron accelerator. Regarding to the level of sensitive and importance of TH781 tube the modulator system designed with high accuracy. So beside of power supplies design the control circuits for protection of the tube have been considered. The results of test and operation of this system that have been constructed in Iran for fist time is very satisfactory

  3. Ground motion and its effects in accelerator design

    International Nuclear Information System (INIS)

    Fischer, G.E.

    1985-07-01

    The effects of ground motion on accelerator design are discussed. The limitations on performance are discussed for various categories of motion. For example, effects due to ground settlement, tides, seismic disturbances and man-induced disturbances are included in this discussion. 42 figs., 7 tabs

  4. Computer codes used in particle accelerator design: First edition

    International Nuclear Information System (INIS)

    1987-01-01

    This paper contains a listing of more than 150 programs that have been used in the design and analysis of accelerators. Given on each citation are person to contact, classification of the computer code, publications describing the code, computer and language runned on, and a short description of the code. Codes are indexed by subject, person to contact, and code acronym

  5. High Field Studies for CLIC Accelerating Structures Development

    CERN Document Server

    Profatilova, I

    2017-01-01

    Compact Linear Collider RF structures need to be able to achieve the very high average accelerating gradient of 100 MV/m. One of the main challenges in reaching such high accelerating gradients is to avoid vacuum electrical breakdown within CLIC accelerating structures. Accelerating structure tests are carried out in the klystron-based test stands known as the XBoxes. In order to investigate vacuum breakdown phenomena and its statistical characteristics in a simpler system and get results in a faster way, pulsed dc systems have been developed at CERN. To acquire sufficient breakdown data in a reasonable period of time, high repetition rate pulse generators are used in the systems for breakdown studies, so-called pulsed dc system. This paper describes the pulsed dc systems and the two high repetition rate circuits, which produce high-voltage pulses for it, available at CERN.

  6. Design and Factory Test of the E /E- Frascati Linear Accelerator for DAFNE

    Energy Technology Data Exchange (ETDEWEB)

    Anamkath, H.; Lyons, S.; Nett, D.; Treas, P.; Whitham, K.; Zante, T.; /Titan Beta, Dublin; Miller, R.; /Titan Beta, Dublin /SLAC; Boni, R.; Hsieh, H.; Sannibale, F.; Vescovi, M.; Vignola, G.; /Frascati

    2011-11-28

    The electron-positron accelerator for the DAFNE project has been built and is in test at Titan Beta in Dublin, CA. This S-Band RF linac system utilizes four 45 MW sledded klystrons and 16-3 m accelerating structures to achieve the required performance. It delivers a 4 ampere electron beam to the positron converter and accelerates the resulting positrons to 550 MeV. The converter design uses a 4.3T pulsed tapered flux compressor along with a pseudo-adiabatic tapered field to a 5 KG solenoid over the first two positron accelerating sections. Quadrupole focusing is used after 100 MeV. The system performance is given in Table 1. This paper briefly describes the design and development of the various subassemblies in this system and gives the initial factory test data.

  7. Experimental Studies of W-Band Accelerator Structures at High Field

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Marc E

    2001-02-09

    A high-gradient electron accelerator is desired for high-energy physics research, where frequency scalings of breakdown and trapping of itinerant beamline particles dictates operation of the accelerator at short wavelengths. The first results of design and test of a high-gradient mm-wave linac with an operating frequency at 91.392 GHz (W-band) are presented. A novel approach to particle acceleration is presented employing a planar, dielectric lined waveguide used for particle acceleration. The traveling wave fields in the planar dielectric accelerator (PDA) are analyzed for an idealized structure, along with a circuit equivalent model used for understanding the structure as a microwave circuit. Along with the W-band accelerator structures, other components designed and tested are high power rf windows, high power attenuators, and a high power squeeze-type phase shifter. The design of the accelerator and its components where eased with the aide of numerical simulations using a finite-difference electromagnetic field solver. Manufacturing considerations of the small, delicate mm-wave components and the steps taken to reach a robust fabrication process are detailed. These devices were characterized under low power using a two-port vector network analyzer to verify tune and match, including measurements of the structures' fields using a bead-pull. The measurements are compared with theory throughout. Addition studies of the W-band structures were performed under high power utilizing a 11.424 GHz electron linac as a current source. Test results include W-band power levels of 200 kW, corresponding to fields in the PDA of over 20 MV/m, a higher gradient than any collider. Planar accelerator devices naturally have an rf quadrupole component of the accelerating field. Presented for the first time are the measurements of this effect.

  8. The roles of frequency and aperture in linac accelerator design

    International Nuclear Information System (INIS)

    Farkas, Z.D.

    1988-09-01

    Expressions for accelerating structure parameters, including those that determine the peak and average power inputs required to attain a given gradient, are given as functions of aperture to wavelength ratio for a 2π/3 mode disk-loaded guide. The value of the wavelength to aperture ratio varies over a large range, corresponding to group velocities that vary from nearly zero to nearly the speed of light. The parameters exhibit proper asymptotic behavior in both limits. These parameters are benchmark values to which parameters for other modes and for other structure shapes can be compared. For example, it will be shown that the increased peak surface field to accelerating field ratio due to increased aperture to wavelength ratio can be reduced by shaping the iris profile. Structure shapes are varied not only to show possible improvement of structure parameters, but also to improve ease of mechanical fabrication and temperature control. 4 refs., 8 figs., 1 tab

  9. Designing an object-oriented scheme for accelerator equipment control

    International Nuclear Information System (INIS)

    Trofimov, N.N.

    1994-01-01

    The object-oriented analysis (OOA) and design (OOD) formalisms developed by Project Technology Inc. is presented in this report. The method was originated in 1979 with the analysis phase of a large real-time project at Lawrence Berkeley Laboratory and since that time has been used in several large-scale industrial projects. It is supported by the Teamwork CASE package from Cadre Technologies Inc. For introducing basic concepts and definitions of the OOA/OOD, a typical accelerator device example: remotely controllable power supply which is used to power magnets in an accelerator beam transfer line is used through out this report. 18 refs., 18 figs

  10. Lattice design of a FFAG accelerator for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Wang Kun; Song Mingtao; Zhang Jinquan; Shenglina

    2014-01-01

    A compact FFAG accelerator for Boron Neutron Capture Therapy (BNCT) has been designed. Firstly, a linear simplified magnet model has been applied to calculate the basic parameters of FFAG accelerator; Then the WINAGILE program is used to design and optimize the lattice, as well as to obtain the critical parameters such as the Beta functions, the dispersion functions, the envelopes and the tunes; Also, the MAD program is used to check the design scheme; Finally, the ZGOUBI program is used to simulate the particles movement in the nonlinear magnetic field. The super period of the FFAG accelerator is 6. The energy is 11 MeV and the eld index k is 1.9. The structure is compact with the circumference of 11.1795 m. The results show that this optimized design has achieved the proposal object. (authors)

  11. Crystal structure prediction accelerated by Bayesian optimization

    Science.gov (United States)

    Yamashita, Tomoki; Sato, Nobuya; Kino, Hiori; Miyake, Takashi; Tsuda, Koji; Oguchi, Tamio

    2018-01-01

    We propose a crystal structure prediction method based on Bayesian optimization. Our method is classified as a selection-type algorithm which is different from evolution-type algorithms such as an evolutionary algorithm and particle swarm optimization. Crystal structure prediction with Bayesian optimization can efficiently select the most stable structure from a large number of candidate structures with a lower number of searching trials using a machine learning technique. Crystal structure prediction using Bayesian optimization combined with random search is applied to known systems such as NaCl and Y2Co17 to discuss the efficiency of Bayesian optimization. These results demonstrate that Bayesian optimization can significantly reduce the number of searching trials required to find the global minimum structure by 30-40% in comparison with pure random search, which leads to much less computational cost.

  12. Hardware Design Considerations for Edge-Accelerated Stereo Correspondence Algorithms

    Directory of Open Access Journals (Sweden)

    Christos Ttofis

    2012-01-01

    Full Text Available Stereo correspondence is a popular algorithm for the extraction of depth information from a pair of rectified 2D images. Hence, it has been used in many computer vision applications that require knowledge about depth. However, stereo correspondence is a computationally intensive algorithm and requires high-end hardware resources in order to achieve real-time processing speed in embedded computer vision systems. This paper presents an overview of the use of edge information as a means to accelerate hardware implementations of stereo correspondence algorithms. The presented approach restricts the stereo correspondence algorithm only to the edges of the input images rather than to all image points, thus resulting in a considerable reduction of the search space. The paper highlights the benefits of the edge-directed approach by applying it to two stereo correspondence algorithms: an SAD-based fixed-support algorithm and a more complex adaptive support weight algorithm. Furthermore, we present design considerations about the implementation of these algorithms on reconfigurable hardware and also discuss issues related to the memory structures needed, the amount of parallelism that can be exploited, the organization of the processing blocks, and so forth. The two architectures (fixed-support based versus adaptive-support weight based are compared in terms of processing speed, disparity map accuracy, and hardware overheads, when both are implemented on a Virtex-5 FPGA platform.

  13. A compact linear accelerator based on a scalable microelectromechanical-system RF-structure

    Science.gov (United States)

    Persaud, A.; Ji, Q.; Feinberg, E.; Seidl, P. A.; Waldron, W. L.; Schenkel, T.; Lal, A.; Vinayakumar, K. B.; Ardanuc, S.; Hammer, D. A.

    2017-06-01

    A new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number of parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further reducing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.

  14. Dedicated medical ion accelerator design study. Final report

    International Nuclear Information System (INIS)

    1977-12-01

    Results and conclusions are reported from a design study for a dedicated medical accelerator. Basing efforts on the current consensus regarding medical requirements, the resulting demands on accelerator and beam delivery systems were analyzed, and existing accelerator technology was reviewed to evaluate the feasibility of meeting these demands. This general analysis was augmented and verified by preparing detailed preliminary designs for sources of therapeutic beams of neutrons, protons and heavy ions. The study indicates that circular accelerators are the most desirable and economical solutions for such sources. Synchrotrons are clearly superior for beams of helium and heavier ions, while synchrotrons and cyclotrons seem equally well suited for protons although they have different strengths and weaknesses. Advanced techniques of beam delivery are of utmost importance in fully utilizing the advantages of particle beams. Several issues are invloved here. First, multi-treatment room arrangements are essential for making optimal use of the high dose rate capabilities of ion accelerators. The design of corresponding beam switching systems, the principles of which are already developed for physics experimental areas, pose no problems. Second, isocentric beam delivery substantially enhances flexibility of dose delivery. After several designs for such devices were completed, it was concluded that high field magnets are necessary to keep size, bulk and cost acceptable. Third, and most important, is the generation of large, homogeneous radiation fields. This is presently accomplished with the aid of scattering foils, occluding rings, collimators, ridge filters, and boluses. A novel approach, three-dimensional beam scanning, was developed here, and the most demanding components of such a system (fast-scanning magnet and power supply) were built and tested

  15. UHECR acceleration in dark matter filaments of cosmological structure formation

    Science.gov (United States)

    Malkov, M. A.; Sagdeev, R. Z.; Diamond, P. H.

    2011-04-01

    A mechanism for proton acceleration to ~ 1021 eV is suggested. It may operate in accretion flows onto thin dark matter filaments of cosmic structure formation. The flow compresses the ambient magnetic field to strongly increase and align it with the filament. Particles begin the acceleration by E × B drift with the accretion flow. The energy gain in the drift regime is limited by the conservation of the adiabatic invariant p⊥2/B(r). Upon approaching the filament, the drift turns into the gyro-motion around the filament so that the particle moves parallel to the azimuthal electric field. In this `betatron' regime the acceleration speeds up to rapidly reach the electrodynamic limit cpmax = eBR for an accelerator with magnetic field B and the orbit radius R (Larmor radius). The periodic orbit becomes unstable and the particle slings out of the filament to the region of a weak (uncompressed) magnetic field, which terminates the acceleration. To escape the filament, accelerated particles must have gyro-radii comparable with the filament radius. Therefore, the mechanism requires pre-acceleration that is likely to occur in large scale shocks upstream or nearby the filament accretion flow. Previous studies identify such shocks as efficient proton accelerators, with a firm upper limit ~ 1019.5 eV placed by the catastrophic photo-pion losses. The present mechanism combines explosive energy gain in its final (betatron) phase with prompt particle release from the region of strong magnetic field. It is this combination that allows protons to overcome both the photo-pion and the synchrotron-Compton losses and therefore attain energy ~ 1021 eV. A customary requirement on accelerator power to reach a given Emax, which is placed by the accelerator energy dissipation proptoEmax2/Z0 due to the finite vacuum impedance Z0, is circumvented by the cyclic operation of the accelerator.

  16. ASAP - A symbolic algebra package for accelerator design

    International Nuclear Information System (INIS)

    Bozoki, E.; Friedman, A.; Ben-Zvi, I.

    1991-01-01

    The design of a modern accelerator is a complicated task that involves the integration of many devices. As a consequence many parameters must be optimized in order to achieve a satisfactory result. Even the design of a simple subsystem, such as a bending system, requires that the designer will pick a successful choice from a wide range of alternatives. Usually, the task is too large to allow an analytical design, and the designer has to use a computer code (such as MAD or TRANSPORT) to simulate the system and numerically find the desired conditions. The disadvantages of this numerical method are, that (1) the solutions, i.e. the choice of the parameters may or may not be optimal and (2) each change in a parameter requires to recalculate the whole system, thus a detailed design is lengthy and costly. The authors report the conceptual design and primary implementation steps of a symbolic algebra program based on MACSYMA for the design of accelerators, storage rings and transport lines. The motivation for using symbolic algebra is discussed and a design case is presented that shows the advantage of this approach

  17. Experimental demonstration of dielectric structure based two beam acceleration

    International Nuclear Information System (INIS)

    Gai, W.; Conde, M. E.; Konecny, R.; Power, J. G.; Schoessow, P.; Sun, X.; Zou, P.

    2000-01-01

    We report on the experimental results of the dielectric based two beam accelerator (step-up transformer). By using a single high charge beam, we have generated and extracted a high power RF pulse from a 7.8 GHz primary dielectric structure and then subsequently transferred to a second accelerating structure with higher dielectric constant and smaller transverse dimensions. We have measured the energy change of a second (witness) beam passing through the acceleration stage. The measured gradient is >4 times the deceleration gradient. The detailed experiment of set-up and results of the measurements are dimmed. Future plans for the development of a 100 MeV demonstration accelerator based on this technique is presented

  18. Structural response of a rail acceleration

    International Nuclear Information System (INIS)

    Wang, S.Y.

    1984-01-01

    The transient response of a 0.4 by 0.6 cm rectangular bore rail accelerator was analyzed by a three dimensional finite element code. The copper rail deflected to a peak value of 0.08 mm in compression and then oscillated at an amplitude of 0.02 mm. Simultaneously the insulating side wall of glass fabric base, epoxy resin laminate (G-10) was compressed to a peak value of 0.13 mm and rebounded to a steady state in extension. Projectile pinch or blowby due to the rail extension or compression, respectively, can be identified by examining the time history of the rail displacement. The effect of blowby was most significant at the side wall characterized by mm size displacement in compression. Dynamic stress calculations indicate that the G-10 supporting material behind the rail is subjected to over 21 MPa at which the G-10 could fail if the laminate was not carefully oriented. Results for a polycarbonate resin (Lexan) side wall show much larger displacements and stresses than for G-10. The tradeoff between the transparency of Lexan and the mechanical strength of G-10 for sidewall material is obvious. Displacement calculations from the modal method are smaller than the results from the direct integration method by almost an order of magnitude, because the high frequency effect is neglected. 12 references

  19. Development and test of a planar R-band accelerating structure

    CERN Document Server

    Merte, R; Peikert, M; Yu, D

    1999-01-01

    Planar accelerating structures, so called muffin tins, are of great interest for new accelerating techniques which are operating at high frequencies. At present the upper frequency limit for high power sources is 29.9855 GHz available at CERN. Therefore a new design of a planar traveling wave constant impedance accelerating structure is presented. A fully engineered 37-cell prototype with an operating frequency of 29.9855 GHz, which is designed for the 2 pi /3-mode, was fabricated by CNC milling technology. The design includes a power coupler, a cavity geometry optimized to compensate the effect of transverse forces, vacuum flanges and beam pipe flanges. Shown are the frequency scan of transmission and reflection measurements compared to numerical simulations with GdfidL. Further, a non resonant bead pull measurement was made to determine and verify the fundamental modes of the structure. The cavity is planned to be powered at the CLIC test stand at CERN. (4 refs).

  20. Accelerating Vaccine Formulation Development Using Design of Experiment Stability Studies.

    Science.gov (United States)

    Ahl, Patrick L; Mensch, Christopher; Hu, Binghua; Pixley, Heidi; Zhang, Lan; Dieter, Lance; Russell, Ryann; Smith, William J; Przysiecki, Craig; Kosinski, Mike; Blue, Jeffrey T

    2016-10-01

    Vaccine drug product thermal stability often depends on formulation input factors and how they interact. Scientific understanding and professional experience typically allows vaccine formulators to accurately predict the thermal stability output based on formulation input factors such as pH, ionic strength, and excipients. Thermal stability predictions, however, are not enough for regulators. Stability claims must be supported by experimental data. The Quality by Design approach of Design of Experiment (DoE) is well suited to describe formulation outputs such as thermal stability in terms of formulation input factors. A DoE approach particularly at elevated temperatures that induce accelerated degradation can provide empirical understanding of how vaccine formulation input factors and interactions affect vaccine stability output performance. This is possible even when clear scientific understanding of particular formulation stability mechanisms are lacking. A DoE approach was used in an accelerated 37(°)C stability study of an aluminum adjuvant Neisseria meningitidis serogroup B vaccine. Formulation stability differences were identified after only 15 days into the study. We believe this study demonstrates the power of combining DoE methodology with accelerated stress stability studies to accelerate and improve vaccine formulation development programs particularly during the preformulation stage. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  1. Design and development of R.F. LINAC accelerator components

    International Nuclear Information System (INIS)

    Abhay Kumar; Guha, S.; Balasubramaniam, R.; Jawale, S.B.

    2003-01-01

    Full text: Radio frequency linear accelerator, a high power electron LINAC technology, is being developed at BARC. These accelerators are considered to be the most compact and effective for a given power capacity. Important application areas of this LINAC include medical sterilization, food preservation, pollution control, semiconductor industries, radiation therapy and material science. Center for Design and Manufacture (CDM), BARC has been entrusted with the design, development and manufacturing of various mechanical components of the accelerator. Most critical and precision components out of them are Diagnostic chamber, Faraday cup, Drift tube and R.F. cavities. This paper deals with the design aspects in respect of Ultra high vacuum compatibility and the mechanism of operation. Also this paper discusses the state-of-art technology for machining of intricate contour using specially designed poly crystalline diamond tool and the inspection methodology developed to minimize the measurement errors on the machined contour. Silver brazing technique employed to join the LINAC cavities is also described in detail

  2. Workshop on Accelerator Magnet Superconductors, Design and Optimization

    CERN Document Server

    WAMSDO Workshop

    2009-01-01

    This report contains the proceedings of the CARE-HHH-AMT Workshop on Accelerator Magnet Superconductors, Design and Optimization (WAMSDO) held at CERN from 19 to 23 May 2008. The needs in terms of superconducting magnets for the accelerator projects were discussed, mainly for the LHC interaction regions and injector upgrades, and for the GSI FAIR complex. The first part of the workshop focused on the development of superconductor and cables, i.e., low-loss Nb-Ti cables, Nb$_{3}$Sn and high-temperature superconductors. An industry session summarized the actual plans and status of the activities in the main European industries. Then, a worldwide status of the high field magnets programme was presented. A special session was devoted to fast cycled magnets, including FAIR facilities and LHC injector upgrades. A final session focused on the optimization methods and numerical tools for magnet design.

  3. New developments in design and applications for Pelletron accelerators

    International Nuclear Information System (INIS)

    Norton, Greg

    2002-01-01

    Most of the developments over the last several years related to Pelletron accelerator are in the field of accelerator mass spectrometry (AMS) and other low beam current applications with the exception of a very high DC electron recirculation Pelletron. High precision AMS systems based on tandem pelletrons from 500 kV to 5 MV terminal potential are now in use for routine high precision AMS measurements. Their performance will be reported. In addition, there has been significant advancement in the design of the multi-cathode SNICS source for the use of both gas and solid samples within a single source. The latest performance of these sources will be discussed. New diagnostics is being developed for very low beam currents. The latest design of the low current beam profile monitor (LCBPM) will also be presented. (author)

  4. Three-dimensional dielectric photonic crystal structures for laser-driven acceleration

    Directory of Open Access Journals (Sweden)

    Benjamin M. Cowan

    2008-01-01

    Full Text Available We present the design and simulation of a three-dimensional photonic crystal waveguide for linear laser-driven acceleration in vacuum. The structure confines a synchronous speed-of-light accelerating mode in both transverse dimensions. We report the properties of this mode, including sustainable gradient and optical-to-beam efficiency. We present a novel method for confining a particle beam using optical fields as focusing elements. This technique, combined with careful structure design, is shown to have a large dynamic aperture and minimal emittance growth, even over millions of optical wavelengths.

  5. Design study of an accelerator for heavy ion fusion

    International Nuclear Information System (INIS)

    Katayama, T.; Noda, A.; Tokuda, N.; Hirao, Y.

    1980-01-01

    Design of a demonstration accelerator for heavy ion fusion based on a synchrotron system is briefly described. The proposed complex system of injector linac, rapid cycling synchrotron and five accumulation rings can produce a peak current 1.6 kA, peak power 32 TW and total energy 0.3 MJ. Investigations of the intrabeam scattering give a lifetime of the beam longer than the fusion cycle time of 1 sec

  6. Theoretical temperature model with experimental validation for CLIC Accelerating Structures

    CERN Document Server

    AUTHOR|(CDS)2126138; Vamvakas, Alex; Alme, Johan

    Micron level stability of the Compact Linear Collider (CLIC) components is one of the main requirements to meet the luminosity goal for the future $48 \\,km$ long underground linear accelerator. The radio frequency (RF) power used for beam acceleration causes heat generation within the aligned structures, resulting in mechanical movements and structural deformations. A dedicated control of the air- and water- cooling system in the tunnel is therefore crucial to improve alignment accuracy. This thesis investigates the thermo-mechanical behavior of the CLIC Accelerating Structure (AS). In CLIC, the AS must be aligned to a precision of $10\\,\\mu m$. The thesis shows that a relatively simple theoretical model can be used within reasonable accuracy to predict the temperature response of an AS as a function of the applied RF power. During failure scenarios or maintenance interventions, the RF power is turned off resulting in no heat dissipation and decrease in the overall temperature of the components. The theoretica...

  7. Analysis of Higher Order Modes in Large Superconducting Radio Frequency Accelerating Structures

    CERN Document Server

    Galek, Tomasz; Brackebusch, Korinna; Van Rienen, Ursula

    2015-01-01

    Superconducting radio frequency cavities used for accelerating charged particle beams are commonly used in accelerator facilities around the world. The design and optimization of modern superconducting RF cavities requires intensive numerical simulations. Vast number of operational parameters must be calculated to ensure appropriate functioning of the accelerating structures. In this study, we primarily focus on estimation and behavior of higher order modes in superconducting RF cavities connected in chains. To calculate large RF models the state-space concatenation scheme, an efficient hybrid method, is employed.

  8. Linear IFMIF Prototype Accelerator (LIPAc) Control System: Design and development

    Energy Technology Data Exchange (ETDEWEB)

    Calvo Pinto, J.

    2014-07-01

    Distributed real time control systems in scientific instruments, such as particle accelerators or telescopes, have emerged as a solution to control multiple interconnected devices, which required constant attention and observation, along with a complete integration of each of its parts. This enhancement is provided by the intense technological development that control devices have suffered in recent years. With respect to the control software, libraries and applications have also emerged in recent times. These sets of tools have been developed collaboratively in various laboratories and research centers worldwide. Experimental Physics and Industrial Control System (EPICS), a set of open source tools capable of controlling most of the devices necessary to operate a particle accelerator, can be pointed as a prime example of this progress. This thesis presents the design and development of the EPICS based control system for Linear IFMIF1 Prototype Accelerator (LIPAc), which construction involves several countries and it is currently being carried out in Rokkasho, Japan. LIPAc comprises a succession of devices and systems that focus and accelerate deuteron beam to an energy of 9 MeV with a current of 125mA, developing a previously unobtainable power of 1.125MW for that given energy...(Author)

  9. Laser fields in dynamically ionized plasma structures for coherent acceleration

    CERN Document Server

    Luu-Thanh, Ph.; Pukhov, A.; Kostyukov, I.

    2015-01-01

    With the emergence of the CAN (Coherent Amplification Network) laser technology, a new scheme for direct particle acceleration in periodic plasma structures has been proposed. By using our full electromagnetic relativistic particle-in-cell (PIC) simulation code equipped with ionisation module, we simulate the laser fields dynamics in the periodic structures of different materials. We study how the dynamic ionization influences the field structure.

  10. Accelerator shield design of KIPT neutron source facility

    International Nuclear Information System (INIS)

    Zhong, Z.; Gohar, Y.

    2013-01-01

    Argonne National Laboratory (ANL) of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of a neutron source facility at KIPT utilizing an electron-accelerator-driven subcritical assembly. Electron beam power is 100 kW, using 100 MeV electrons. The facility is designed to perform basic and applied nuclear research, produce medical isotopes, and train young nuclear specialists. The biological shield of the accelerator building is designed to reduce the biological dose to less than 0.5-mrem/hr during operation. The main source of the biological dose is the photons and the neutrons generated by interactions of leaked electrons from the electron gun and accelerator sections with the surrounding concrete and accelerator materials. The Monte Carlo code MCNPX serves as the calculation tool for the shield design, due to its capability to transport electrons, photons, and neutrons coupled problems. The direct photon dose can be tallied by MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is less than 0.01 neutron per electron. This causes difficulties for Monte Carlo analyses and consumes tremendous computation time for tallying with acceptable statistics the neutron dose outside the shield boundary. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were developed for the study. The generated neutrons are banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron and secondary photon doses. The weight windows variance reduction technique is utilized for both neutron and photon dose calculations. Two shielding materials, i.e., heavy concrete and ordinary concrete, were considered for the shield design. The main goal is to maintain the total

  11. New clic-g structure design

    CERN Document Server

    AUTHOR|(CDS)2082335

    2016-01-01

    The baseline design of the Compact Linear Collider main linac accelerating structure is called ‘CLIC-G’. It is described in the CLIC Conceptual Design Report (CDR) [1]. As shown in Fig. 1, a regular cell of the structure has four waveguides to damp unwanted high-order-modes (HOMs). These waveguides are dimensioned to cut off the fundamental working frequency in order to prevent the degradation of the fundamental mode Q-factor. The cell geometry and HOM damping loads had been extensively optimized in order to maximize the RF-to-beam efficiency, to minimize the cost, and to meet the beam dynamics and the high gradient RF constraints [2

  12. Design and test results of the Low Energy Demonstration Accelerator (LEDA) RF systems

    International Nuclear Information System (INIS)

    Rees, D.; Bradley, J. III; Cummings, K.; Lynch, M.; Regan, A.; Rohlev, T.; Roybal, W.; Wang, Y.M.

    1998-01-01

    The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos will serve as the prototype for the low energy section of the Accelerator Production of Tritium (APT) accelerator. The APT accelerator requires over 200 RF systems each with a continuous wave output power of 1 MW. The reliability and availability of these RF systems is critical to the successful operation of the APT plant and prototypes of these systems are being developed and demonstrated on LEDA. The RF system design for LEDA includes three, 1.2 MW, 350 MHz continuous wave (CW), RF systems driving a radio frequency quadrupole (RFQ) and one, 1.0 MW, CW, RF system driving a coupled-cavity drift tube linac (CCDTL). This paper presents the design and test results for these RF systems including the klystrons, cathode power supply, circulators, RF vacuum windows, accelerator field and resonance control system, and RF transmission components. The three RF systems driving the RFQ use the accelerating structure as a power combiner, and this places some unique requirements on the RF system. These requirements and corresponding operational implications will be discussed

  13. A constant gradient planar accelerating structure for linac use

    International Nuclear Information System (INIS)

    Kang, Y.W.; Matthews, P.J.; Kustom, R.L.

    1995-01-01

    Planar accelerating millimeter-wave structures have been studied during the last few years at Argonne National Laboratory in collaboration with Technical University of Berlin. The cavity structures are intended to be manufactured by using x-ray lithography microfabrication technology. A complete structure consists of two identical planar half structures put together face-to-face. Since microfabrication technology can make a since-depth indentation on a planar substrate, realizing the constant impedance structure was possible but a constant gradient structure was difficult; changing the group velocity along the structure while maintaining the gap and the depth of the indentation constant was difficult. A constant gradient structure has been devised by introducing a cut between the adjacent cavity cells along the beam axis of each half structure. The width of the cut is varied along the longitudinal axis of the structure to have proper coupling between the cells. The result of the computer simulation on such structures is shown

  14. Challenges in the design of linear accelerator tunnels and services

    CERN Document Server

    Osborne, John

    2008-01-01

    Studies are well underway for the next generation of linear accelerators. The International Linear Collider (ILC) is working towards a maximum collision energy of 1 TeV and the Compact Linear Collider (CLIC) even higher at 3 TeV. Although the accelerating technologies are very different, many similarities can be found between the two projects from a civil engineering and technical services point of view. Both projects would require a site of approximately 50 km in length with stable geological conditions. CERN has been selected as one of the sample sites for the preliminary studies. The aim of this paper is to present the key challenges in the design of civil engineering and technical services such as cooling, ventilation and electricity that need to be overcome to realise such large scale projects in the future.

  15. Dielectric-Lined High-Gradient Accelerator Structure

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2012-04-24

    Rectangular particle accelerator structures with internal planar dielectric elements have been studied, with a view towards devising structures with lower surface fields for a given accelerating field, as compared with structures without dielectrics. Success with this concept is expected to allow operation at higher accelerating gradients than otherwise on account of reduced breakdown probabilities. The project involves studies of RF breakdown on amorphous dielectrics in test cavities that could enable high-gradient structures to be built for a future multi-TeV collider. The aim is to determine what the limits are for RF fields at the surfaces of selected dielectrics, and the resulting acceleration gradient that could be achieved in a working structure. The dielectric of principal interest in this study is artificial CVD diamond, on account of its advertised high breakdown field ({approx}2 GV/m for dc), low loss tangent, and high thermal conductivity. Experimental studies at mm-wavelengths on materials and structures for achieving high acceleration gradient were based on the availability of the 34.3 GHz third-harmonic magnicon amplifier developed by Omega-P, and installed at the Yale University Beam Physics Laboratory. Peak power from the magnicon was measured to be about 20 MW in 0.5 {micro}s pulses, with a gain of 54 dB. Experiments for studying RF high-field effects on CVD diamond samples failed to show any evidence after more than 10{sup 5} RF pulses of RF breakdown up to a tangential surface field strength of 153 MV/m; studies at higher fields were not possible due to a degradation in magnicon performance. A rebuild of the tube is underway at this writing. Computed performance for a dielectric-loaded rectangular accelerator structure (DLA) shows highly competitive properties, as compared with an existing all-metal structure. For example, comparisons were made of a DLA structure having two planar CVD diamond elements with a all-metal CERN structure HDS

  16. Determination of Velocity And Acceleration of Structural Deformation ...

    African Journals Online (AJOL)

    Determination of Velocity And Acceleration of Structural Deformation Using Kalman Filter Technique. ... This paper outlines the procedure of geodetic monitoring system of circular oil storage tanks and presents the analysis of the resulted observations to determine the values of their deformation. At the Forcados Tank Farm, ...

  17. Assembly Test of Elastic Averaging Technique to Improve Mechanical Alignment for Accelerating Structure Assemblies in CLIC

    CERN Document Server

    Huopana, J

    2010-01-01

    The CLIC (Compact LInear Collider) is being studied at CERN as a potential multi-TeV e+e- collider [1]. The manufacturing and assembly tolerances for the required RF-components are important for the final efficiency and for the operation of CLIC. The proper function of an accelerating structure is very sensitive to errors in shape and location of the accelerating cavity. This causes considerable issues in the field of mechanical design and manufacturing. Currently the design of the accelerating structures is a disk design. Alternatively it is possible to create the accelerating assembly from quadrants, which favour the mass manufacturing. The functional shape inside of the accelerating structure remains the same and a single assembly uses less parts. The alignment of these quadrants has been previously made kinematic by using steel pins or spheres to align the pieces together. This method proved to be a quite tedious and time consuming method of assembly. To limit the number of different error sources, a meth...

  18. Development of software for charged particle accelerator design automation

    International Nuclear Information System (INIS)

    Budkin, V.A.; Volodin, V.A.; Gul'yants, A.L.

    1985-01-01

    Main programs of the computer-aided design system (CADS) intended for numerical simulation of electromagnetic fields in accelerating and focusing systems of electron and ion linacs as well as for simulation of particle beams are described in short. CADS is an open system and is designed for operation with the ES1010 computer. It can be easily adapted for any minicomputer, in particular, for the SM-4. The system considered envisages use of man-machine dialog within the framework of PRIMUS collective access system. Further CADS development will be connected with development or adaptation of problem-oriented programs as well as with modernization of the whole-system means designed for providing maximum conveniences forusers

  19. Electron acceleration by femtosecond laser interaction with micro-structured plasmas

    Science.gov (United States)

    Goers, Andy James

    Laser-driven accelerators are a promising and compact alternative to RF accelerator technology for generating relativistic electron bunches for medical, scientific, and security applications. This dissertation presents three experiments using structured plasmas designed to advance the state of the art in laser-based electron accelerators, with the goal of reducing the energy of the drive laser pulse and enabling higher repetition rate operation with current laser technology. First, electron acceleration by intense femtosecond laser pulses in He-like nitrogen plasma waveguides is demonstrated. Second, significant progress toward a proof of concept realization of quasi-phasematched direct acceleration (QPM-DLA) is presented. Finally, a laser wakefield accelerator at very high plasma density is studied, enabling relativistic electron beam generation with ˜10 mJ pulse energies. Major results from these experiments include: • Acceleration of electrons up to 120 MeV from an ionization injected wakefield accelerator driven in a 1.5 mm long He-like nitrogen plasma waveguide • Guiding of an intense, quasi-radially polarized femtosecond laser pulse in a 1 cm plasma waveguide. This pulse provides a strong drive field for the QPM-DLA concept. • Wakefield acceleration of electrons up to ˜10 MeV with sub-terawatt, ˜10 mJ pulses interacting with a thin (˜200 mum), high density (>1020 cm-3) plasma. • Observation of an intense, coherent, broadband wave breaking radiation flash from a high plasma density laser wakefield accelerator. The flash radiates > 1% of the drive laser pulse energy in a bandwidth consistent with half-cycle (˜1 fs) emission from violent unidirectional acceleration of electron bunches from rest. These results open the way to high repetition rate (>˜kHz) laser-driven generation of relativistic electron beams with existing laser technology.

  20. Structural design by CAD system

    International Nuclear Information System (INIS)

    Kim, Jhin Wung; Shim, Jae Ku; Kim, Sun Hoon; Kim, Dae Hong; Lee, Kyung Jin; Choi, Kyu Sup; Choi, In Kil; Lee, Dong Yong

    1988-12-01

    CAD systems are now widely used for the design of many engineering problems involving static, dynamic and thermal stress analyses of structures. In order to apply CAD systems to the structural analysis and design, the function of hardwares and softwares necessary for the CAD systems must be understood. The purpose of this study is to introduce the basic elements that are indispensible in the application of CAD systems to the analysis and design of structures and to give a thorough understanding of CAD systems to design engineers, so as to participate in the further technological developments of CAD systems. Due to the complexity and variety of the shape and size of the nowa-days structures, the need of new design technologies is growing for more efficient, accurate and economical design of structures. The application of CAD systems to structural engineering fields enables to improve structural engineering analysis and design technologies and also to obtain the standardization of the design process. An active introduction of rapidly developing CAD technologies will contribute to analyzing and designing structures more efficiently and reliably. Based on this report of the current status of the application of CAD systems to the structural analysis and design, the next goal is to develop the expert system which enables to perform the design of structures by CAD systems from the preliminary conceptual design to the final detail drawings automatically. (Author)

  1. Status of the Fatigue Studies on the CLIC Accelerating Structures

    CERN Document Server

    Calatroni, S; Neupert, H; Wuensch, Walter; CERN. Geneva

    2006-01-01

    The need for high accelerating gradients for the future multi-TeV e+e- Compact Linear Collider (CLIC) imposes considerable constraints on the materials of the accelerating structures. The surfaces exposed to high pulsed RF (Radio Frequency) currents are subject to cyclic thermal stresses which are expected to induce surface break up by fatigue. Since no fatigue data exists in the literature up to very large numbers of cycles and for the particular stress pattern present in RF cavities, a comprehensive study of copper alloys in this parameter range has been initiated. Fatigue data for selected copper alloys in different states are presented

  2. Design of an upgradeable 45-100 mA RFQ accelerator for FAIR

    International Nuclear Information System (INIS)

    Zhang Chuan; Schempp, Alwin

    2009-01-01

    A 325 MHz, 35 mA, 3 MeV Radio-Frequency Quadrupole (RFQ) accelerator will be operated as the first accelerating structure of the proton linac injector for the newly planned international science center Facility for Antiproton and Ion Research (FAIR) at GSI, Germany. In previous design studies, two high beam intensities, 70 and 100 mA, were used. Most recently, the design intensity has been changed to 45 mA, which is closer to the operational value. Taking advantage of the so-called New Four-Section Procedure, a new design, which is upgradable from 45 to 100 mA, has been developed for the FAIR proton RFQ. Besides the upgradability analyses, robustness studies of the new design to spatial displacements of the input beam and field errors are presented as well.

  3. Superconducting accelerating structures for very low velocity ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Shepard, K.W.; Ostroumov, P.N.; Fuerst, J.D.; Waldschmidt, G.; /Argonne; Gonin, I.V.; /Fermilab

    2008-01-01

    This paper presents designs for four types of very-low-velocity superconducting accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006 < v/c < 0.06. Superconducting TEM-class cavities have been widely applied to CW acceleration of ion beams. SC linacs can be formed as an array of independently-phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the US and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front-end of such linacs, particularly for the post-acceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008 < {beta} = v/c < 0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  4. Fabrication and cold test of photonic band gap resonators and accelerator structures

    Directory of Open Access Journals (Sweden)

    Evgenya I. Smirnova

    2005-09-01

    Full Text Available We present the detailed description of the successful design and cold test of photonic band gap (PBG resonators and traveling-wave accelerator structures. Those tests provided the essential basis for later hot test demonstration of the first PBG accelerator structure at 17.140 GHz [E. I. Smirnova, A. S. Kesar, I. Mastovsky, M. A. Shapiro, and R. J. Temkin, Phys. Rev. Lett., 95, 074801 (2005.PRLTAO0031-900710.1103/PhysRevLett.95.074801]. The advantage of PBG resonators is that they were built to support only the main, TM_{01}-like, accelerator mode while not confining the higher-order modes (HOM or wakefields. The design of the PBG resonators was based on a triangular lattice of rods, with a missing rod at the center. Following theoretical analysis, the rod radius divided by the rod spacing was held to a value of about 0.15 to avoid supporting HOM. For a single-cell test the PBG structure was fabricated in X-band (11 GHz and brazed. The mode spectrum and Q factor (Q=5 000 agreed well with theory. Excellent HOM suppression was evident from the cold test. A six-cell copper PBG accelerator traveling-wave structure with reduced long-range wakefields was designed and was built by electroforming at Ku-band (17.140 GHz. The structure was tuned by etching the rods. Cold test of the structure yielded excellent agreement with the theoretical design. Successful results of the hot test of the structure demonstrating the acceleration of the electron beam were published in E. I. Smirnova, A. S. Kesar, I. Mastovsky, M. A. Shapiro, and R. J. Temkin, Phys. Rev. Lett., 95, 074801 (2005.PRLTAO0031-900710.1103/PhysRevLett.95.074801

  5. A Bayesian Optimal Design for Sequential Accelerated Degradation Testing

    Directory of Open Access Journals (Sweden)

    Xiaoyang Li

    2017-07-01

    Full Text Available When optimizing an accelerated degradation testing (ADT plan, the initial values of unknown model parameters must be pre-specified. However, it is usually difficult to obtain the exact values, since many uncertainties are embedded in these parameters. Bayesian ADT optimal design was presented to address this problem by using prior distributions to capture these uncertainties. Nevertheless, when the difference between a prior distribution and actual situation is large, the existing Bayesian optimal design might cause some over-testing or under-testing issues. For example, the implemented ADT following the optimal ADT plan consumes too much testing resources or few accelerated degradation data are obtained during the ADT. To overcome these obstacles, a Bayesian sequential step-down-stress ADT design is proposed in this article. During the sequential ADT, the test under the highest stress level is firstly conducted based on the initial prior information to quickly generate degradation data. Then, the data collected under higher stress levels are employed to construct the prior distributions for the test design under lower stress levels by using the Bayesian inference. In the process of optimization, the inverse Gaussian (IG process is assumed to describe the degradation paths, and the Bayesian D-optimality is selected as the optimal objective. A case study on an electrical connector’s ADT plan is provided to illustrate the application of the proposed Bayesian sequential ADT design method. Compared with the results from a typical static Bayesian ADT plan, the proposed design could guarantee more stable and precise estimations of different reliability measures.

  6. Design & simulation of a 800 kV dynamitron accelerator by CST studio

    Directory of Open Access Journals (Sweden)

    A M Aghayan

    2015-09-01

    Full Text Available Nowadays, middle energy electrostatic accelerators in industries are widely used due to their high efficiency and low cost compared with other types of accelerators. In this paper, the importance and applications of electrostatic accelerators with 800 keV energy are studied. Design and simulation of capacitive coupling of a dynamitron accelerator is proposed. Furthermore, accelerating tube are designed and simulated by means of CST Suit Studio

  7. Design and validation of an accelerator for an ultracold electron source

    Directory of Open Access Journals (Sweden)

    G. Taban

    2008-05-01

    Full Text Available We describe here a specially designed accelerator structure and a pulsed power supply that are essential parts of a high brightness cold atoms-based electron source. The accelerator structure allows a magneto-optical atom trap to be operated inside of it, and also transmits subnanosecond electric field pulses. The power supply produces high voltage pulses up to 30 kV, with a rise time of up to 30 ns. The resulting electric field inside the structure is characterized with an electro-optic measurement and with an ion time-of-flight experiment. Simulations predict that 100 fC electron bunches, generated from trapped atoms inside the structure, reach an emittance of 0.04 mm mrad and a bunch length of 80 ps.

  8. Optimum design of steel structures

    CERN Document Server

    Farkas, József

    2013-01-01

    This book helps designers and manufacturers to select and develop the most suitable and competitive steel structures, which are safe, fit for production and economic. An optimum design system is used to find the best characteristics of structural models, which guarantee the fulfilment of design and fabrication requirements and minimize the cost function. Realistic numerical models are used as main components of industrial steel structures. Chapter 1 containts some experiences with the optimum design of steel structures Chapter 2 treats some newer mathematical optimization methods. Chapter 3 gives formulae for fabrication times and costs. Chapters 4 deals with beams and columns. Summarizes the Eurocode rules for design. Chapter 5 deals with the design of tubular trusses. Chapter 6 gives the design of frame structures and fire-resistant design rules for a frame. In Chapters 7 some minimum cost design problems of stiffened and cellular plates and shells are worked out for cases of different stiffenings and loads...

  9. Design, testing and modifications of the Pelletron accelerator and future uses

    International Nuclear Information System (INIS)

    Lopez V, H.; Valdovinos A, M.; Hernandez M, V.; Alba P, U.; Garcia R, R.; Rodriguez, R.; Alba P, R.; Ruiz M, J.

    1989-01-01

    Solutions to various problems in the design of high voltage generator and acceleration units of the Pelletron electron accelerator designed and constructed at ININ are presented. Information on the design of the control system of the electron beams, activities proposed for utilization of sulfur hexafluoride as an accelerator isolating gas as well as some future uses of the Pelletron. (Author). 7 refs, 3 figs

  10. Design of cavities of a standing wave accelerating tube for a 6 MeV electron linear accelerator

    Directory of Open Access Journals (Sweden)

    S Zarei

    2017-08-01

    Full Text Available Side-coupled standing wave tubes in  mode are widely used in the low-energy electron linear accelerator, due to high accelerating gradient and low sensitivity to construction tolerances. The use of various simulation software for designing these kinds of tubes is very common nowadays. In this paper, SUPERFISH code and COMSOL are used for designing the accelerating and coupling cavities for a 6 MeV electron linear accelerator. Finite difference method in SUPERFISH code and Finite element method in COMSOL are used to solve the equations. Besides, dimension of accelerating and coupling cavities and also coupling iris dimension are optimized to achieve resonance frequency of 2.9985 MHz and coupling constant of 0.0112. Considering the results of this study and designing of the RF energy injection port subsequently, the construction of 6 MeV electron tube will be provided

  11. Comparison of the conditioning of High Gradient Accelerating Structures

    CERN Document Server

    Degiovanni, Alberto; Giner Navarro, Jorge

    2016-01-01

    Accelerating gradients in excess of 100 MV/m, at very low breakdown rates, have been successfully achieved in numerous CLIC prototype accelerating structures. The conditioning and operational histories of several structures, tested at KEK and CERN, have been compared and there is clear evidence that the conditioning progresses with the number of RF pulses and not the number of breakdowns. This observation opens the possibility that the optimum conditioning strategy, which minimizes the total number of breakdowns the structure is subject to without increasing conditioning time, may be to never exceed the breakdown rate target for operation. The result is also likely to have a strong impact on efforts to understand the physical mechanism underlying conditioning and may lead to preparation procedures which reduce conditioning time.

  12. Mechanical design considerations of a standing wave s-band accelerator with on-axis couplers

    International Nuclear Information System (INIS)

    Hodge, S.B.; Funk, L.W.; Schriber, S.O.

    1976-01-01

    The mechanical design of S-band standing wave accelerator structures with on-axis coupling cells includes material selection, cavity design, segment production, rf tuning and brazing procedures. Pre-assembly tuning operations have been minimized by determining segment dimensions and tolerances so that segments can easily be fabricated in a near-finished condition by a commercial machining firm. Final tuning, if necessary, is easily achieved by removal of material from the cavity wall or drift tube nose. Considerations in choosing brazing procedures were vacuum integrity, resistivity of brazing alloy, joint thickness, alignment of the structure assembly and restriction of grain growth. (author)

  13. Computation of Eigenmodes in Long and Complex Accelerating Structures by Means of Concatenation Strategies

    CERN Document Server

    Fligsen, T; Van Rienen, U

    2014-01-01

    The computation of eigenmodes for complex accelerating structures is a challenging and important task for the design and operation of particle accelerators. Discretizing long and complex structures to determine its eigenmodes leads to demanding computations typically performed on super computers. This contribution presents an application example of a method to compute eigenmodes and other parameters derived from these eigenmodes for long and complex structures using standard workstation computers. This is accomplished by the decomposition of the complex structure into several single segments. In a next step, the electromagnetic properties of the segments are described in terms of a compact state-space model. Subsequently, the state-space models of the single structures are concatenated to the full structure. The results of direct calculations are compared with results obtained by the concatenation scheme in terms of computational time and accuracy.

  14. Design and development of RF components for linear accelerator

    International Nuclear Information System (INIS)

    Kumar, Girish; Mathur, Pratigya; Joshi, Gopal; Kumar, Rajesh; Ramarao, B.V.

    2013-01-01

    Low Energy High Intensity Proton Accelerator (LEHIPA) project is presently under development at BARC. It requires several RF components around 150 MHz, 350 MHz and 2.45 GHz. We have been working on the design and development of various RF components, which are useful for LEHIPA project. To start with, it requires high power RF sources, which were built for many decades using electron tubes and klystrons, while the solid-state technology had been used for low power amplifiers. The advancement in the high power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) allowed us to design and develop a few hundreds of watts of amplifier modules. Eight such power amplifier modules have been combined using 8-way power combiner and divider. Total power amplifier has been tested up to 1.8 kW at 350 MHz. Special precautions had to be taken for thermal management using heat sink and water cooling at various stages of the amplifier

  15. Proceedings of the Advanced Hadron Facility accelerator design workshop

    International Nuclear Information System (INIS)

    Thiessen, H.A.

    1989-01-01

    The International Workshop on Hadron Facility Technology was held February 22-27, 1988, at the Study Center at Los Alamos National Laboratory. The program included papers on facility plans, beam dynamics, and accelerator hardware. The parallel sessions were particularly lively with discussions of all facets of kaon factory design. The workshop provided an opportunity for communication among the staff involved in hadron facility planning from all the study groups presently active. The recommendations of the workshop include: the need to use h=1 RF in the compressor ring; the need to minimize foil hits in painting schemes for all rings; the need to consider single Coulomb scattering in injection beam los calculations; the need to study the effect of field inhomogeneity in the magnets on slow extraction for the 2.2 Tesla main ring of AHF; and agreement in principle with the design proposed for a joint Los Alamos/TRIUMF prototype main ring RF cavity

  16. Design of a side coupled standing wave accelerating tube for NSTRI e-Linac

    Science.gov (United States)

    Zarei, S.; Abbasi Davani, F.; Lamehi Rachti, M.; Ghasemi, F.

    2017-09-01

    The design and construction of a 6 MeV electron linear accelerator (e-Linac) was defined in the Institute of Nuclear Science and Technology (NSTRI) for cargo inspection and medical applications. For this accelerator, a side coupled standing wave tube resonant at a frequency of 2998.5 MHZ in π/2 mode was selected. In this article, the authors provide a step-by-step explanation of the process of the design for this tube. The design and simulation of the accelerating and coupling cavities were carried out in five steps; (1) separate design of the accelerating and coupling cavities, (2) design of the coupling aperture between the cavities, (3) design of the entire structure for resonance at the nominal frequency, (4) design of the buncher, and (5) design of the power coupling port. At all design stages, in addition to finding the dimensions of the cavity, the impact of construction tolerances and simulation errors on the electromagnetic parameters were investigated. The values obtained for the coupling coefficient, coupling constant, quality factor and capture efficiency are 2.11, 0.011, 16203 and 36%, respectively. The results of beam dynamics study of the simulated tube in ASTRA have yielded a value of 5.14 π-mm-mrad for the horizontal emittance, 5.06 π-mm-mrad for the vertical emittance, 1.17 mm for the horizontal beam size, 1.16 mm for the vertical beam size and 1090 keV for the energy spread of the output beam.

  17. Network Representation of Multi-Cell Accelerating Structures

    CERN Document Server

    Raguin, J Y

    2001-01-01

    The analysis of the electrodynamic properties of a complete multi-cell accelerating structure using electromagnetic numerical simulation codes is presently at the edge of existing computer capabilities. To overcome this limitation, a network representation is proposed which derives the overall scattering transfer matrix of such multi-cell structures from single-cell data calculated using the commercial finite-element code HFSS. For a constant-impedance structure, computation of the eigenvalues of this matrix allows dispersion diagrams to be obtained. In the more general case, this formalism leads to a representation of the coupled-chain of cavities as a set of cascaded non identical multipoles.

  18. RF measurements of a traveling-wave muffin-tin accelerating structure at 90 GHz

    International Nuclear Information System (INIS)

    Chou, P.J.; Bowden, G.B.; Copeland, M.R.; Menegat, A.; Pritzkau, D.P.; Siemann, R.H.

    1997-05-01

    A measuring system at the table-top scale was developed for RF measurements of a muffin-tin accelerating structure operating at 32 times the SLAC frequency (2.856 GHz). Both perturbation and non-perturbation methods are employed to characterize the RF properties of a muffin-tin structure. Conventional bead pull measurements are extended to millimeter wavelengths. Design of the measuring system and preliminary results of RF measurements are presented

  19. Technical infra-structure for accelerators in Brazil

    International Nuclear Information System (INIS)

    Polga, T.

    1983-01-01

    A minimal technical support infra-structura for, operation, maintenance and development suitable to a multi-user laboratory is presented. The costs of this infra-structure are 1.300 MCr$ in equipment and 700 MCr$ in people. A coordinated utilization of a particle accelerator network existing in the country and its corresponding costs are shown. Considerations in relation to the local of the sinchrotron radiation laboratory implantation are done. (L.C.) [pt

  20. Accelerator design of the KEK B-Factory

    International Nuclear Information System (INIS)

    Kurokawa, Shin-ichi; Satoh, Kotaro; Kikutani, Eiji

    1991-03-01

    A design study has been made for the KEK B-Factory, an accelerator complex dedicated to the detection of the CP-violation effect of B-mesons. It is an asymmetric two-ring electron-positron collider of 3.5x8 GeV within a new tunnel measuring 1273 m circumference. The design peak luminosity is to be 10 34 cm -2 s -1 , which will be realized in two steps. The luminosity is to be 2 x 10 33 cm -2 s -1 with a head-on collision scheme in the first step; it is then increased to a final value of 10 34 cm -2 s -1 with a finite-angle crossing scheme. This document comprises two parts; the first part presents an overview of the design; the second part is a collection of papers giving detailed descriptions of various subjects. Stress is put on the design of the first step; the second step is mentioned when necessary. (author)

  1. Improved electron collimation system design for Elekta linear accelerators.

    Science.gov (United States)

    Pitcher, Garrett M; Hogstrom, Kenneth R; Carver, Robert L

    2017-09-01

    Prototype 10 × 10 and 20 × 20-cm 2 electron collimators were designed for the Elekta Infinity accelerator (MLCi2 treatment head), with the goal of reducing the trimmer weight of excessively heavy current applicators while maintaining acceptable beam flatness (±3% major axes, ±4% diagonals) and IEC leakage dose. Prototype applicators were designed initially using tungsten trimmers of constant thickness (1% electron transmission) and cross-sections with inner and outer edges positioned at 95% and 2% off-axis ratios (OARs), respectively, cast by the upstream collimating component. Despite redefining applicator size at isocenter (not 5 cm upstream) and reducing the energy range from 4-22 to 6-20 MeV, the designed 10 × 10 and 20 × 20-cm 2 applicator trimmers weighed 6.87 and 10.49 kg, respectively, exceeding that of the current applicators (5.52 and 8.36 kg, respectively). Subsequently, five design modifications using analytical and/or Monte Carlo (MC) calculations were applied, reducing trimmer weight while maintaining acceptable in-field flatness and mean leakage dose. Design Modification 1 beveled the outer trimmer edges, taking advantage of only low-energy beams scattering primary electrons sufficiently to reach the outer trimmer edge. Design Modification 2 optimized the upper and middle trimmer distances from isocenter for minimal trimmer weights. Design Modification 3 moved inner trimmer edges inward, reducing trimmer weight. Design Modification 4 determined optimal X-ray jaw positions for each energy. Design Modification 5 adjusted middle and lower trimmer shapes and reduced upper trimmer thickness by 50%. Design Modifications 1→5 reduced trimmer weights from 6.87→5.86→5.52→5.87→5.43→3.73 kg for the 10 × 10-cm 2 applicator and 10.49→9.04→8.62→7.73→7.35→5.09 kg for the 20 × 20-cm 2 applicator. MC simulations confirmed these final designs produced acceptable in-field flatness and met IEC-specified leakage dose at 7, 13, and 20 Me

  2. Accelerating VASP electronic structure calculations using graphic processing units

    KAUST Repository

    Hacene, Mohamed

    2012-08-20

    We present a way to improve the performance of the electronic structure Vienna Ab initio Simulation Package (VASP) program. We show that high-performance computers equipped with graphics processing units (GPUs) as accelerators may reduce drastically the computation time when offloading these sections to the graphic chips. The procedure consists of (i) profiling the performance of the code to isolate the time-consuming parts, (ii) rewriting these so that the algorithms become better-suited for the chosen graphic accelerator, and (iii) optimizing memory traffic between the host computer and the GPU accelerator. We chose to accelerate VASP with NVIDIA GPU using CUDA. We compare the GPU and original versions of VASP by evaluating the Davidson and RMM-DIIS algorithms on chemical systems of up to 1100 atoms. In these tests, the total time is reduced by a factor between 3 and 8 when running on n (CPU core + GPU) compared to n CPU cores only, without any accuracy loss. © 2012 Wiley Periodicals, Inc.

  3. X-band photonic band-gap accelerator structure breakdown experiment

    Directory of Open Access Journals (Sweden)

    Roark A. Marsh

    2011-02-01

    Full Text Available In order to understand the performance of photonic band-gap (PBG structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz. The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65  MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110  MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100  MV/m and a surface magnetic field of 890  kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14  MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  4. Simulations and Vacuum Tests of a CLIC Accelerating Structure

    CERN Document Server

    Garion, C

    2011-01-01

    The Compact LInear Collider, under study, is based on room temperature high gradient structures. The vacuum specificities of these cavities are low conductance, large surface areas and a non-baked system. The main issue is to reach UHV conditions (typically 10-7 Pa) in a system where the residual vacuum is driven by water outgassing. A finite element model based on an analogy thermal/vacuum has been built to estimate the vacuum profile in an accelerating structure. Vacuum tests are carried out in a dedicated set-up, the vacuum performances of different configurations are presented and compared with the predictions.

  5. High-performance insulator structures for accelerator applications

    International Nuclear Information System (INIS)

    Sampayan, S.E.; Caporaso, G.J.; Sanders, D.M.; Stoddard, R.D.; Trimble, D.O.; Elizondo, J.; Krogh, M.L.; Wieskamp, T.F.

    1997-05-01

    A new, high gradient insulator technology has been developed for accelerator systems. The concept involves the use of alternating layers of conductors and insulators with periods of order 1 mm or less. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We describe our ongoing studies investigating the degradation of the breakdown electric field resulting from alternate fabrication techniques, the effect of gas pressure, the effect of the insulator-to-electrode interface gap spacing, and the performance of the insulator structure under bi-polar stress

  6. Precise fabrication of X-band accelerating structure

    International Nuclear Information System (INIS)

    Higo, T.; Sakai, H.; Higashi, Y.; Koike, S.; Takatomi, T.

    1994-01-01

    An accelerating structure with a/λ=0.16 is being fabricated to study a precise fabrication method. A frequency control of each cell better than 10 -4 level is required to realize a detuned structure. The present machining level is nearly 1 MHz/11.4 GHz in relative frequency error, which just satisfies the above requirement. To keep this machining precision, the diffusion bonding technique is found preferable to join the cells. Various diffusion conditions were tried. The frequency change can be less than 1 MHz/11.4 GHz and it can be controlled well better than that. (author)

  7. Review of reactor transmutation waste design by accelerator technology

    International Nuclear Information System (INIS)

    Sudarmono; Silakhuddin

    2002-01-01

    Design of an accelerator drive waste transmutation system for minor actinide burning has been assessed. The burning system used target consists of a set of solid tungsten and lead plates, cooled by heavy water and surrounded by a lead annulus. The annular blanket, which surrounds the target, consists of a set of AcO 2 slurry bearing tubes, each 3 meters long, surrounded by heavy water moderator. Heat removal from the slurry tubes is by passing the rapidly moving slurry through an external exchanger. The resulting of multiplication factor is an increasing function of concentration. The lumped actinide value is flat. But the important ration of parasitic capture per fission is a function of concentration. The results of calculation are eliminated 3407, 613 and 136 moles per year of actinides, 9 9 T c, and 1 27,129 I , respectively, from LWR waste. The net electrical production is 600 MWe

  8. Conceptual design of industrial free electron laser using superconducting accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N. [Automatic Systems Corporation, Samara (Russian Federation)] [and others

    1995-12-31

    Paper presents conceptual design of free electron laser (FEL) complex for industrial applications. The FEL complex consists of three. FEL oscillators with the optical output spanning the infrared (IR) and ultraviolet (UV) wave-lengths ({lambda} = 0.3...20 {mu}m) and with the average output power 10 - 20 kW. The driving beam for the FELs is produced by a superconducting accelerator. The electron beam is transported to the FELs via three beam lines (125 MeV and 2 x 250 MeV). Peculiar feature of the proposed complex is a high efficiency of the. FEL oscillators, up to 20 %. This becomes possible due to the use of quasi-continuous electron beam and the use of the time-dependent undulator tapering.

  9. The physics design of accelerator-driven transmutation systems

    Energy Technology Data Exchange (ETDEWEB)

    Venneri, F. [Los Alamos National Laboratory, NM (United States)

    1995-10-01

    Nuclear systems under study in the Los Alamos Accelerator-Driven Transmutation Technology program (ADTT) will allow the destruction of nuclear spent fuel and weapons-return plutonium, as well as the production of nuclear energy from the thorium cycle, without a long-lived radioactive waste stream. The subcritical systems proposed represent a radical departure from traditional nuclear concepts (reactors), yet the actual implementation of ADTT systems is based on modest extrapolations of existing technology. These systems strive to keep the best that the nuclear technology has developed over the years, within a sensible conservative design envelope and eventually manage to offer a safe, less expensive and more environmentally sound approach to nuclear power.

  10. Seismic site coefficients and acceleration design response spectra based on conditions in South Carolina : final report.

    Science.gov (United States)

    2014-11-15

    The simplified procedure in design codes for determining earthquake response spectra involves : estimating site coefficients to adjust available rock accelerations to site accelerations. Several : investigators have noted concerns with the site coeff...

  11. Linear collider RF structure design using ARGUS

    International Nuclear Information System (INIS)

    Kwok Ko

    1991-01-01

    In a linear collider, both the driving system (klystrons) and the accelerating system (linac) consists of RF structures that are inherently three-dimensional. These structures which are responsible for power input/output, have to satisfy many requirements in order that instabilities, beam or RF related, are to be avoided. At the same time, system efficiencies have to be maintained at optimal to minimize cost. Theoretical analysis on these geometrically complex structures are difficult and until recently, numerical solutions have been limited. At SLAC, there has been a continuing and close collaboration among accelerator physicists, engineers and numericists to integrate supercomputing into the design procedure which involves 3-D RF structures. The outcome is very encouraging. Using the 3-D/electromagnetic code ARGUS (developed by SAIC) on the Cray computers at NERSC in conjunction with supporting theories, a wide variety of critical components have been simulated and evaluated. Aside from structures related to the linear collider, the list also includes the RF cavity for the proposed Boson Factory and the anode circuit for the Cross-Field Amplifier, once considered as an alternative to the klystron as a possible power source. This presentation will focus on two specific structures: (1) the klystron output cavity; and (2) the linac input coupler. As the results demonstrate, supercomputing is fast becoming a viable technology that could conceivably replace actual cold-testing in the near future

  12. Development of the heat sink structure of a beam dump for the proton accelerator

    International Nuclear Information System (INIS)

    Maeng, W. Y.; Gil, C. S.; Kim, J. H.; Kim, D. H.

    2007-01-01

    The beam dump is the essential component for the good beam quality and the reliable performance of the proton accelerator. The beam dump for a 20 MeV and 20 mA proton accelerator was designed and manufactured in this study. The high heats deposited, and the large amount of radioactivity produced in beam dump should be reduced by the proper heat sink structure. The heat source by the proton beam of 20 MeV and 20 mA was calculated. The radioactivity assessments of the beam dump were carried out for the economic shielding design with safety. The radioactivity by the protons and secondary neutrons in designed beam dump were calculated in this sturdy. The effective engineering design for the beam dump cooling was performed, considering the mitigation methods of the deposited heats with small angle, the power densities with the stopping ranges in the materials and the heat distributions in the beam dump. The heat sink structure of the beam dump was designed to meet the accelerator characteristics by placing two plates of 30 cm by 60 cm at an angle of 12 degree. The highest temperatures of the graphite, copper, and copper faced by cooling water were designed to be 223 degree, 146 degree, and 85 degree, respectively when the velocity of cooling water was 3 m/s. The heat sink structure was manufactured by the brazing graphite tiles to a copper plate with the filler alloy of Ti-Cu-Ag. The brazing procedure was developed. The tensile stress of the graphite was less than 75% of a maximum tensile stress during the accelerator operation based on the analysis. The safety analyses for the commissioning of the accelerator operation were also performed. The specimens from the brazed parts of beam dump structure were made to identify manufacturing problems. The soundness of the heat sink structure of the beam dump was confirmed by the fatigue tests of the brazed specimens of the graphite-copper tile components with the repetitive heating and cooling. The heat sink structure developed

  13. Micro structure processing on plastics by accelerated hydrogen molecular ions

    Science.gov (United States)

    Hayashi, H.; Hayakawa, S.; Nishikawa, H.

    2017-08-01

    A proton has 1836 times the mass of an electron and is the lightest nucleus to be used for accelerator in material modification. We can setup accelerator with the lowest acceleration voltage. It is preferable characteristics of Proton Beam Writer (PBW) for industrial applications. On the contrary ;proton; has the lowest charge among all nuclei and the potential impact to material is lowest. The object of this research is to improve productivity of the PBW for industry application focusing on hydrogen molecular ions. These ions are generated in the same ion source by ionizing hydrogen molecule. There is no specific ion source requested and it is suitable for industrial use. We demonstrated three dimensional (3D) multilevel micro structures on polyester base FPC (Flexible Printed Circuits) using proton, H2+ and H3+. The reactivity of hydrogen molecular ions is much higher than that of proton and coincident with the level of expectation. We can apply this result to make micro devices of 3D multilevel structures on FPC.

  14. Magnetic field design for a Penning ion source for a 200 keV electrostatic accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Fathi, A., E-mail: Atefeh.Fathi115@gmail.com [Radiation Applications Department, Shahid Beheshti University, G. C., Tehran (Iran, Islamic Republic of); Feghhi, S.A.H.; Sadati, S.M. [Radiation Applications Department, Shahid Beheshti University, G. C., Tehran (Iran, Islamic Republic of); Ebrahimibasabi, E. [Department of Physics, Shahrood University of Technology, 3619995161, Shahrood (Iran, Islamic Republic of)

    2017-04-01

    In this study, the structure of magnetic field for a Penning ion source has been designed and constructed with the use of permanent magnets. The ion source has been designed and constructed for a 200 keV electrostatic accelerator. With using CST Studio Suite, the magnetic field profile inside the ion source was simulated and an appropriate magnetic system was designed to improve particle confinement. Designed system consists of two ring magnets with 9 mm distance from each other around the anode. The ion source was constructed and the cylindrical magnet and designed magnetic system were tested on the ion source. The results showed that the ignition voltage for ion source with the designed magnetic system is almost 300 V lower than the ion source with the cylindrical magnet. Better particle confinement causes lower voltage discharge to occur.

  15. Preliminary design for a recirculating induction accelerator for heavy ion fusion

    International Nuclear Information System (INIS)

    Yu, S.S.; Barnard, J.J.; Caporaso, G.J.; Friedman, A.; Hewett, D.W.; Kirbie, H.; Newton, M.A.; Neil, V.K.; Paul, A.C.; Reginato, L.L.; Sharp, W.M.; Godlove, T.F.; Bangerter, R.O.; Fong, C.G.; Judd, D.L.

    1990-12-01

    Substantial savings in size and cost over a linear machine may be achieved in an induction accelerator in which a heavy ion beam makes many (∼50) passes through one or more circular accelerators. We examine a point design for such an accelerator, consisting of four rings. We discuss the consequences of this design on emittance growth, longitudinal instability growth, vacuum requirements, pulser requirements, pulsed-magnet requirements, acceleration schedule, and cost. 3 refs., 1 tab

  16. Growth of Structure in Theories of Cosmic Acceleration

    DEFF Research Database (Denmark)

    Cataneo, Matteo

    , gravitation being the dominant force at large distances. Under these premises, to explain the observed late-time accelerated expansion of the universe we need an exotic form of energy with large negative pressure, named dark energy. Lambda is the simplest candidate for this obscure ingredient......, and is currently associated with the energy density of the vacuum. Cold dark matter is the second most abundant constituent of the universe, even though it has not been detected yet. This slowly moving collection of particles forms the scaffolding of the stunning, luminous structures we see with our telescopes....... Although both dark components are so far in the realm of speculation, a cosmological constant suffers from important theoretical shortcomings. An alternative is to question the validity of General Relativity on cosmological scales. In fact, cosmic acceleration could stem from gravity behaving differently...

  17. Masonry structural design for buildings

    Science.gov (United States)

    1982-08-01

    Masonry structures shall be designed in accordance with the requirements of this manual. Applicable building codes and exceptions thereto are noted in the manual. The structural design information is based upon the engineered design concept in which walls and columns are analyzed on a stress basis which is considered a refinement of commonly used empirical methods. The design curves and sample calculations will materially contribute to the speed and accuracy of the design of brick and concrete masonry buildings. Since some of the referenced Army publications may be in conflict with Navy criteria, engineers using this manual for Navy projects should use applicable Navy criteria.

  18. A tuning method for nonuniform traveling-wave accelerating structures

    International Nuclear Information System (INIS)

    Gong Cunkui; Zheng Shuxin; Shao Jiahang; Jia Xiaoyu; Chen Huaibi

    2013-01-01

    The tuning method of uniform traveling-wave structures based on non-resonant perturbation field distribution measurement has been widely used in tuning both constant-impedance and constant-gradient structures. In this paper, the method of tuning nonuniform structures is proposed on the basis of the above theory. The internal reflection coefficient of each cell is obtained from analyzing the normalized voltage distribution. A numerical simulation of tuning process according to the coupled cavity chain theory has been done and the result shows each cell is in right phase advance after tuning. The method will be used in the tuning of a disk-loaded traveling-wave structure being developed at the Accelerator Laboratory, Tsinghua University. (authors)

  19. A conceptual design of the DTL-SDTL for the JAERI high intensity proton accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Ino, Hiroshi; Kabeya, Zenzaburo [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Chishiro, Etsuji; Ouchi, Nobuo; Hasegawa, Kazuo; Mizumoto, Motoharu

    1998-08-01

    A high intensity proton linear accelerator with an energy of 1.5 GeV and an average beam power of 8 MW has been proposed for the Neutron Science Project (NSP) at JAERI. This linac starts with radio-frequency quadrupole (RFQ) linac, which is followed by a drift-tube linac (DTL), separated-type DTL (SDTL), and a superconducting structure. In this report, we focus on the DTL and SDTL part of the accelerator. The DTL accelerates the beam from 2 to 51 MeV, and SDTL accelerates the beam from 51 to 10 MeV. Since the main features of the requirement for the DTL-SDTL are high peak current ({approx}30 mA) and a high-duty factor ({approx}CW), the conceptual design should be determined not only based on the result of a beam-dynamics calculation, but by careful study of the cooling problems. The design processes of the DTL-SDTL and the matching sections (RFQ to DTL, CW-Pulse merge section, and SDTL to SCC) and the result of a heat transfer analysis of DTL are described. (author)

  20. Shielding design for the target room of the proton accelerator research center

    International Nuclear Information System (INIS)

    Min, Y. S.; Lee, C. W.; Mun, K. J.; Nam, J.; Kim, J. Y.

    2010-01-01

    The Proton Engineering Frontier Project (PEFP) has been developing a 100-MeV proton linear accelerator. Also, PEFP has been designing the Proton Accelerator Research Center (PARC). In the Accelerator Tunnel and Beam Experiment Hall in PARC, 10 target rooms for the 20- and 100-MeV beamline facilities exist in the Beam Experiment Hall. For the 100-MeV target rooms during 100-MeV proton beam extraction, a number of high energy neutrons, ranging up to 100-MeV, are produced. Because of the high beam current and space limitations of each target room, the shielding design of each target room should be considered seriously. For the shielding design of the 100-MeV target rooms of the PEFP, a permanent and removable local shield structure was adopted. To optimize shielding performance, we evaluated four different shield materials (concrete, HDPE, lead, iron). From the shielding calculation results, we confirmed that the proposed shielding design made it possible to keep the dose rate below the 'as low as reasonably achievable (ALARA)' objective.

  1. Computer control of large accelerators design concepts and methods

    Energy Technology Data Exchange (ETDEWEB)

    Beck, F.; Gormley, M.

    1984-05-01

    Unlike most of the specialities treated in this volume, control system design is still an art, not a science. These lectures are an attempt to produce a primer for prospective practitioners of this art. A large modern accelerator requires a comprehensive control system for commissioning, machine studies and day-to-day operation. Faced with the requirement to design a control system for such a machine, the control system architect has a bewildering array of technical devices and techniques at his disposal, and it is our aim in the following chapters to lead him through the characteristics of the problems he will have to face and the practical alternatives available for solving them. We emphasize good system architecture using commercially available hardware and software components, but in addition we discuss the actual control strategies which are to be implemented since it is at the point of deciding what facilities shall be available that the complexity of the control system and its cost are implicitly decided. 19 references.

  2. Computer control of large accelerators design concepts and methods

    International Nuclear Information System (INIS)

    Beck, F.; Gormley, M.

    1984-05-01

    Unlike most of the specialities treated in this volume, control system design is still an art, not a science. These lectures are an attempt to produce a primer for prospective practitioners of this art. A large modern accelerator requires a comprehensive control system for commissioning, machine studies and day-to-day operation. Faced with the requirement to design a control system for such a machine, the control system architect has a bewildering array of technical devices and techniques at his disposal, and it is our aim in the following chapters to lead him through the characteristics of the problems he will have to face and the practical alternatives available for solving them. We emphasize good system architecture using commercially available hardware and software components, but in addition we discuss the actual control strategies which are to be implemented since it is at the point of deciding what facilities shall be available that the complexity of the control system and its cost are implicitly decided. 19 references

  3. Thermo-mechanical design of the SINGAP accelerator grids for ITER NB Injectors

    International Nuclear Information System (INIS)

    Agostinetti, P.; Dal Bello, S.; Palma, M.D.; Zaccaria, P.

    2006-01-01

    The SINGle Aperture - SINgle GAP (SINGAP) accelerator for ITER neutral beam injector foresees four grids for the extraction and acceleration of negative ions, instead of the seven grids of the Multi Aperture Multi Grid (MAMuG) reference configuration. Optimized geometry of the SINGAP grids (plasma, extraction, pre-acceleration, and grounded grid) was identified by CEA Association considering specific requirements for ions extraction and beam generation referring to experimental data and code simulations. This paper focuses on the thermo-hydraulic and thermo-mechanical design of the grids carried out by Consorzio RFX for the design of the first ITER NB Injector and the ITER NB Test Facility. The cooling circuit design (position and shape of the channels) and the cooling parameters (water coolant temperatures, pressure and velocity) were optimized with thermo-hydraulic and thermo-mechanical sensitivity analyses in order to satisfy the grid functional requirements (temperatures, in plane and out of plane deformations). A complete and detailed thermo-structural design assessment of the SINGAP grids was accomplished applying the structural design rules for ITER in-vessel components and considering both the reference load conditions and the maximum load provided by the power supplies. The design required a complete modelling of the grids and their support frames by means of 3D FE and CAD models. The grids were finally integrated with the support and cooling systems inside the beam source vessel. The main results of the thermo-hydraulic and thermo-mechanical analyses are presented. The open issues are then reported, mainly regarding the material properties characterization (static and fatigue tests) and the qualification of technologies for OFHC copper electro-deposition, brazing, and welding of heterogeneous materials. (author)

  4. Accelerating Dynamic Cardiac MR Imaging Using Structured Sparse Representation

    Directory of Open Access Journals (Sweden)

    Nian Cai

    2013-01-01

    Full Text Available Compressed sensing (CS has produced promising results on dynamic cardiac MR imaging by exploiting the sparsity in image series. In this paper, we propose a new method to improve the CS reconstruction for dynamic cardiac MRI based on the theory of structured sparse representation. The proposed method user the PCA subdictionaries for adaptive sparse representation and suppresses the sparse coding noise to obtain good reconstructions. An accelerated iterative shrinkage algorithm is used to solve the optimization problem and achieve a fast convergence rate. Experimental results demonstrate that the proposed method improves the reconstruction quality of dynamic cardiac cine MRI over the state-of-the-art CS method.

  5. Parametric Fires for Structural Design

    DEFF Research Database (Denmark)

    Hertz, Kristian

    2012-01-01

    The authorities, the construction association, and a number of companies in Denmark have supported the author writing a guide for design of building structures for parametric fires. The guide is published by the ministry as a supplement to the building regulations. However, consultants...... and contractors have asked for a reference in English in order to make the guide-lines and the background for them available internationally. The paper therefore presents recommendations from the design guide especially concerning how to assess parametric design fires based on the opening factor method for large...... compartments. Findings leading to the guide-lines are discussed, and it is indicated what a safe design fire model means for structural design and how it differs from a safe design fire model for evacuation. Furthermore, the paper includes some experiences from the application of the design guide in practise...

  6. Earthquake design for controlled structures

    Directory of Open Access Journals (Sweden)

    Nikos G. Pnevmatikos

    2017-04-01

    Full Text Available An alternative design philosophy, for structures equipped with control devices, capable to resist an expected earthquake while remaining in the elastic range, is described. The idea is that a portion of the earthquake loading is under¬taken by the control system and the remaining by the structure which is designed to resist elastically. The earthquake forces assuming elastic behavior (elastic forces and elastoplastic behavior (design forces are first calculated ac¬cording to the codes. The required control forces are calculated as the difference from elastic to design forces. The maximum value of capacity of control devices is then compared to the required control force. If the capacity of the control devices is larger than the required control force then the control devices are accepted and installed in the structure and the structure is designed according to the design forces. If the capacity is smaller than the required control force then a scale factor, α, reducing the elastic forces to new design forces is calculated. The structure is redesigned and devices are installed. The proposed procedure ensures that the structure behaves elastically (without damage for the expected earthquake at no additional cost, excluding that of buying and installing the control devices.

  7. Accelerators

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  8. Accelerating structure of the CERN new 50 MeV linac

    International Nuclear Information System (INIS)

    Warner, D.J.

    1976-01-01

    The design of the post-coupled Alvarez structure is presented with emphasis on features which are novel and critical especially as regards acceleration of high currents (150 mA) to 50 MeV. Among topics treated are the sequence of computational techniques leading from unit cell (e.m. field) calculations to dynamics of the complete linac, and model measurements which justify the drift-tube girder support approach and our particular post-coupler arrangement. (author)

  9. Advanced Beamline Design for Fermilab's Advanced Superconducting Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, Christopher [Northern Illinois Univ., DeKalb, IL (United States)

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) at Fermilab is a new electron accelerator currently in the commissioning stage. In addition to testing superconducting accelerating cavities for future accelerators, it is foreseen to support a variety of Advanced Accelerator R&D (AARD) experiments. Producing the required electron bunches with the expected flexibility is challenging. The goal of this dissertation is to explore via numerical simulations new accelerator beamlines that can enable the advanced manipulation of electron bunches. The work especially includes the design of a low-energy bunch compressor and a study of transverse-to-longitudinal phase space exchangers.

  10. Nuclear design aspect of the Korean high intensity proton accelerator project

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jonghwa; Song, Tae-Yung [Korea Atomic Energy Research Inst., Yusong, Taejon (Korea, Republic of)

    1998-11-01

    A plan to construct a high current proton accelerator has been proposed by KAERI. We are presenting the required nuclear design to support the project as well as a brief overview of the proposed proton accelerator. The target and core design is highlighted to show feasibility of incineration of minor actinides from the spent fuel of light water reactors. Radiation shielding and activation analyses are also important for the design and the license of the accelerator. (author)

  11. Hybrid Tower, Designing Soft Structures

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette; Tamke, Martin; Holden Deleuran, Anders

    2015-01-01

    predictions about the inherent interdependency and material dependent performance of the hybrid structure and (2) the inter-scalar design strategies for specification and fabrication. The first investigation focuses on the design pipelines developed between the implementation of realtime physics......This paper presents the research project Hybrid Tower, an interdisciplinary collaboration between CITA—Centre for IT and Architecture, KET—Department for Structural Design and Technology, Fibrenamics, Universidade do Minho Guimarães, AFF a. ferreira & filhos, sa, Caldas de Vizela, Portugal...... and Essener Labor für Leichte Flächentragwerke, Universität Duisburg-Essen. Hybrid Tower is a hybrid structural system combining bending active compression members and tensile members for architectural design. The paper presents two central investigations: (1) the creation of new design methods that embed...

  12. Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thatar Vento, V., E-mail: Vladimir.ThatarVento@gmail.com [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [CONICET, Av. Rivadavia 1917 (1033), Ciudad Autonoma de Buenos Aires (Argentina); Bergueiro, J.; Cartelli, D. [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [CONICET, Av. Rivadavia 1917 (1033), Ciudad Autonoma de Buenos Aires (Argentina); Valda, A.A. [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, UNSAM, M. Irigoyen 3100 (1650), San Martin, Buenos Aires (Argentina); Kreiner, A.J. [Gerencia de Investigacion y Aplicaciones, CNEA, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina)] [CONICET, Av. Rivadavia 1917 (1033), Ciudad Autonoma de Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, UNSAM, M. Irigoyen 3100 (1650), San Martin, Buenos Aires (Argentina)

    2011-12-15

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam.

  13. Design of spheromak injector using conical accelerator for large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Miyazawa, J.; Yamada, H.; Yasui, K.; Kato, S. [National Inst. for Fusion Science, Toki, Gifu (Japan); Fukumoto, N.; Nagata, M.; Uyama, T. [Himeji Inst. of Tech., Hyogo (Japan)

    1999-11-01

    Optimization of CT injector for LHD has been carried out and conical electrode for adiabatic CT compression is adopted in the design. Point-model of CT acceleration in a co-axial electrode is solved to optimize the electrode geometry and the power supplies. Large acceleration efficiency of 34% is to be obtained with 3.2 m long conical accelerator and 40 kV - 42 kJ power supply. The operation scenario of a CT injector named SPICA mk. I (SPheromak Injector using Conical Accelerator) consisting of 0.8 m conical accelerator is discussed based on this design. (author)

  14. Design of APhF-IH Linac for a Compact Medical Accelerator

    CERN Document Server

    Kapin, V; Iwata, Y

    2003-01-01

    The design of a small injection linac for a compact medical synchrotron is discussed. The linac design is based on interdigital H-type (IH) drift-tube structure with alternative phase focusing (APhF). A high acceleration rate and an absence of magnetic lenses inside drift-tubes reduce the cost and length of APhF-IH linac in comparison with HIMAC linac based on Alvarez structure with magnet quadrupoles inside drift-tubes. To reduce effects of emittance growth, the RFQ structure is used in front of the APhF linac. In such linac layout, the current transmission of a carbon beam can reach up to 90-100%. In this report, the basic parameters of whole linac are presented, while the design of APhF structure is considered in details. Two reference designs of 4 MeV/u 200 MHz APhF linacs with different voltage distributions along the whole tank have been generated and analyzed numerically. For the first design, a constant voltage distribution along the tank is assumed. The total length of the structure is about 4.2 m. F...

  15. Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, C. B.; Esarey, E.; Benedetti, C.; Toth, Cs.; Geddes, C. G. R.; Leemans, W.P.

    2010-06-01

    Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. The implications for accelerator design and the different physical mechanisms of laser-driven and beam-driven plasma acceleration are discussed. Driver propagation is examined, as well as the effects of the excited plasma wave phase velocity. The driver coupling to subsequent plasma accelerator stages for high-energy physics applications is addressed.

  16. Observation of Wakefield Suppression in a Photonic-Band-Gap Accelerator Structure

    Science.gov (United States)

    Simakov, Evgenya I.; Arsenyev, Sergey A.; Buechler, Cynthia E.; Edwards, Randall L.; Romero, William P.; Conde, Manoel; Ha, Gwanghui; Power, John G.; Wisniewski, Eric E.; Jing, Chunguang

    2016-02-01

    We report experimental observation of higher order mode (HOM) wakefield suppression in a room-temperature traveling-wave photonic-band-gap (PBG) accelerating structure at 11.700 GHz. It has been long recognized that PBG structures have the potential for reducing long-range wakefields in accelerators. The first ever demonstration of acceleration in a room-temperature PBG structure was conducted in 2005. Since then, the importance of PBG accelerator research has been recognized by many institutions. However, the full experimental characterization of the wakefield spectrum and demonstration of wakefield suppression when the accelerating structure is excited by an electron beam has not been performed to date. We conducted an experiment at the Argonne Wakefield Accelerator test facility and observed wakefields excited by a single high charge electron bunch when it passes through a PBG accelerator structure. Excellent HOM suppression properties of the PBG accelerator were demonstrated in the beam test.

  17. The International Linear Collider Technical Design Report - Volume 3.I: Accelerator R&D in the Technical Design Phase

    CERN Document Server

    Adolphsen, Chris; Barish, Barry; Buesser, Karsten; Burrows, Philip; Carwardine, John; Clark, Jeffrey; Durand, Hélène Mainaud; Dugan, Gerry; Elsen, Eckhard; Enomoto, Atsushi; Foster, Brian; Fukuda, Shigeki; Gai, Wei; Gastal, Martin; Geng, Rongli; Ginsburg, Camille; Guiducci, Susanna; Harrison, Mike; Hayano, Hitoshi; Kershaw, Keith; Kubo, Kiyoshi; Kuchler, Victor; List, Benno; Liu, Wanming; Michizono, Shinichiro; Nantista, Christopher; Osborne, John; Palmer, Mark; Paterson, James McEwan; Peterson, Thomas; Phinney, Nan; Pierini, Paolo; Ross, Marc; Rubin, David; Seryi, Andrei; Sheppard, John; Solyak, Nikolay; Stapnes, Steinar; Tauchi, Toshiaki; Toge, Nobu; Walker, Nicholas; Yamamoto, Akira; Yokoya, Kaoru

    2013-01-01

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to incr...

  18. Design and rf tuning of the KEK 40 MeV proton linear accelerator

    International Nuclear Information System (INIS)

    Kato, Takao.

    1986-09-01

    An Alvarez linac was designed and constructed on the basis of a model linac study to increase the output energy from 20 to 40 MeV. The linac was tuned by frequency tuners and post couplers. Stabilization of the field was achieved and a variation within ± 0.7 % of the accelerating field was obtained. An equivalent circuit analysis which can numerically solve loop equations, including stem and post currents in addition to tank current, can explain the rf characteristics of a postcoupled structure. (author)

  19. RF properties of periodic accelerating structures for linear colliders

    International Nuclear Information System (INIS)

    Wang, J.W.

    1989-07-01

    With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e + e - physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs

  20. Accelerator production of tritium plant design and supporting engineering development and demonstration work

    International Nuclear Information System (INIS)

    Lisowski, P.W.

    1997-11-01

    Tritium is an isotope of hydrogen with a half life of 12.3 years. Because it is essential for US thermonuclear weapons to function, tritium must be periodically replenished. Since K reactor at Savannah River Site stopped operating in 1988, tritium has been recycled from dismantled nuclear weapons. This process is possible only as long as many weapons are being retired. Maintaining the stockpile at the level called for in the present Strategic Arms Reduction Treaty (START-I) will require the Department of Energy to have an operational tritium production capability in the 2005--2007 time frame. To make the required amount of tritium using an accelerator based system (APT), neutrons will be produced through high energy proton reactions with tungsten and lead. Those neutrons will be moderated and captured in 3 He to make tritium. The APT plant design will use a 1,700 MeV linear accelerator operated at 100 mA. In preparation for engineering design, starting in October 1997 and subsequent construction, a program of engineering development and demonstration is underway. That work includes assembly and testing of the first 20 MeV of the low energy plant linac at 100 mA, high-energy linac accelerating structure prototyping, radiofrequency power system improvements, neutronic efficiency measurements, and materials qualifications

  1. Post-accelerator LINAC design for the VECC RIB project

    Indian Academy of Sciences (India)

    acclerator type of RIB facility. The scheme utilises the existing = 130 room temperature variable energy cyclotron machine as the primary accelerator for the production of RIBs and radio frequency quadrupole (RFQ) and LINAC modules for ...

  2. Structural design of DEALS magnet

    International Nuclear Information System (INIS)

    Bezler, P.; Hsieh, S.Y.; Balderes, T.; Brown, T.; Bundy, J.

    1979-01-01

    A design for the extraneous magnet structure to support all the magnet loads was developed. The structure consists of two demountable structural systems designed to support the in-plane and out-of-plane loads, respectively. The in-plane loads are resisted by a cold central bucking cylinder and pin connected, plate-beam structural members following the outer periphery of each coil. The out-of-plane, torsional loads are resisted by the concerted action of the central bucking column and a continuous plate structure interconnecting all the coils. The adequacy of the structures were assessed by application of finite element analysis methods. The design study proved the feasibility of resisting the magnetic loadings with a demountable support structure extraneous to the superconducting coil. The resulting magnet system, although estimated to be higher in cost than a continuous coil, incorporates a means for complete coil replacement in a time scale commensurate with conventional nuclear power plant repairs and without the dismantling of the toroidal blanket and plasma shell systems

  3. Reliability Based Ship Structural Design

    DEFF Research Database (Denmark)

    Dogliani, M.; Østergaard, C.; Parmentier, G.

    1996-01-01

    This paper deals with the development of different methods that allow the reliability-based design of ship structures to be transferred from the area of research to the systematic application in current design. It summarises the achievements of a three-year collaborative research project dealing...... with developments of models of load effects and of structural collapse adopted in reliability formulations which aim at calibrating partial safety factors for ship structural design. New probabilistic models of still-water load effects are developed both for tankers and for containerships. New results are presented...... of non-linear wave induced load effects and the corresponding long-term formulations. Methods to combine linear and non-linear components of wave induced load effects have been developed and checked by alternative methods.These improved models were used for the reliability assessment of the primary hull...

  4. Instructional Design for Accelerated Macrocognitive Expertise in the Baseball Workplace

    Directory of Open Access Journals (Sweden)

    Peter J. Fadde

    2016-03-01

    Full Text Available The goal of accelerating expertise can leave researchers and trainers in human factors, naturalistic decision making, sport science, and expertise studies concerned about seemingly insufficient application of expert performance theories, findings and methods for training macrocognitive aspects of human performance. Video-occlusion methods perfected by sports expertise researchers have great instructional utility, in some cases offering an effective and inexpensive alternative to high-fidelity simulation. A key problem for instructional designers seems to be that expertise research done in laboratory and field settings doesn’t get adequately translated into workplace training. Therefore, this article presents a framework for better linkage of expertise research/training across laboratory, field, and workplace settings. It also uses a case study to trace the development and implementation of a macrocognitive training program in the very challenging workplace of the baseball batters’ box. This training, which was embedded for a full season in a college baseball team, targeted the perceptual-cognitive skill of pitch recognition that allows expert batters to circumvent limitations of human reaction time in order to hit a 90 mile-per-hour slider. While baseball batting has few analogous skills outside of sports, the instructional design principles of the training program developed to improve batting have wider applicability and implications. Its core operational principle, supported by information processing models but challenged by ecological models, decouples the perception-action link for targeted part-task training of the perception component, in much the same way that motor components routinely are isolated to leverage instructional efficiencies. After targeted perceptual training, perception and action were recoupled via transfer-appropriate tasks inspired by in situ research tasks. Using NCAA published statistics as performance measures

  5. Instructional Design for Accelerated Macrocognitive Expertise in the Baseball Workplace.

    Science.gov (United States)

    Fadde, Peter J

    2016-01-01

    The goal of accelerating expertise can leave researchers and trainers in human factors, naturalistic decision making, sport science, and expertise studies concerned about seemingly insufficient application of expert performance theories, findings and methods for training macrocognitive aspects of human performance. Video-occlusion methods perfected by sports expertise researchers have great instructional utility, in some cases offering an effective and inexpensive alternative to high-fidelity simulation. A key problem for instructional designers seems to be that expertise research done in laboratory and field settings doesn't get adequately translated into workplace training. Therefore, this article presents a framework for better linkage of expertise research/training across laboratory, field, and workplace settings. It also uses a case study to trace the development and implementation of a macrocognitive training program in the very challenging workplace of the baseball batters' box. This training, which was embedded for a full season in a college baseball team, targeted the perceptual-cognitive skill of pitch recognition that allows expert batters to circumvent limitations of human reaction time in order to hit a 90 mile-per-hour slider. While baseball batting has few analogous skills outside of sports, the instructional design principles of the training program developed to improve batting have wider applicability and implications. Its core operational principle, supported by information processing models but challenged by ecological models, decouples the perception-action link for targeted part-task training of the perception component, in much the same way that motor components routinely are isolated to leverage instructional efficiencies. After targeted perceptual training, perception and action were recoupled via transfer-appropriate tasks inspired by in situ research tasks. Using NCAA published statistics as performance measures, the cooperating team

  6. Temperature rise and stress induced by microcracks in accelerating structures

    Directory of Open Access Journals (Sweden)

    W. Zhu

    2010-12-01

    Full Text Available The temperature rise and induced stress due to Ohmic heating in the vicinity of microcracks on the walls of high-gradient accelerating structures are considered. The temperature rise and induced stress depend on the orientation of the crack with respect to the rf magnetic field, the shape of the crack, and the power and duration of the rf pulse. Under certain conditions the presence of cracks can double the temperature rise over that of a smooth surface. Stress at the bottom of the cracks can be several times larger than that of the case when there are no cracks. We study these effects both analytically and by computer simulation. It is shown that the stress in cracks is maximal when the crack depth is on the order of the thermal penetration depth.

  7. Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Amann, J.; Bane, K.; /SLAC

    2009-10-30

    This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

  8. Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report

    International Nuclear Information System (INIS)

    Amann, J.; Bane, K.

    2009-01-01

    This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

  9. Mechanical engineering and design criteria for the Magnetically Insulated Transmission Experiment Accelerator

    International Nuclear Information System (INIS)

    Staller, G.E.; Hamilton, I.D.; Aker, M.F.; Fifer, H.G.

    1978-02-01

    A single-unit electron beam accelerator was designed, fabricated, and assembled in Sandia's Technical Area V to conduct magnetically insulated transmission experiments. Results of these experiments will be utilized in the future design of larger, more complex accelerators. This design makes optimum use of existing facilities and equipment. When designing new components, possible future applications were considered as well as compatibility with existing facilities and hardware

  10. Structuring Principles for the Designer

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth; Pedersen, Per Erik Elgård

    1998-01-01

    This paper suggests a list of structuring principles that support the designer in making alternative concepts for product architectures. Different architectures may support different points of diversification in the product life-cycle. The aim is to balance reuse of resources and reduction...

  11. Ground motions and its effects in accelerator design

    International Nuclear Information System (INIS)

    Fischer, G.E.

    1984-07-01

    This lecture includes a discussion of types of motion, frequencies of interest, measurements at SLAC, some general comments regarding local sources of ground motion at SLAC, and steps that can be taken to minimize the effects of ground motion on accelerators

  12. Analytical researches on the accelerating structures, wakefields, and beam dynamics for future linear colliders

    International Nuclear Information System (INIS)

    Gao, J.

    1996-01-01

    The research works presented in this memoir are oriented not only to the R and D programs towards future linear colliders, but also to the pedagogic purposes. The first part of this memoir (from Chapter 2 to Chapter 9) establishes an analytical framework of the disk-loaded slow wave accelerating structures with can be served as the advanced courses for the students who have got some basic trainings in the linear accelerator theories. The analytical formulae derived in this part describe clearly the properties of the disk-loaded accelerating structures, such as group velocity, shunt impedance, coupling coefficients κ and β, loss factors, and wake fields. The second part (from Chapter 11 to Chapter 13) gives the beam dynamics simulations and the final proposal of an S-Band Superconducting Linear Collider (SSLC) which is aimed to avoid the dark current problem in TESLA project. This memoir has not included all the works conducted since April 1992, such as beam dynamics simulations for CLIC Test Facility (CFT-2) and the design of High Charge Structures (HCS) (11π/12 mode) for CFT-2, in order to make this memoir more harmonious, coherent and continuous. (author)

  13. Design concept of radiation control system for the high intensity proton accelerator facility

    CERN Document Server

    Miyamoto, Y; Harada, Y; Ikeno, K

    2002-01-01

    Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics.

  14. Computer codes for particle accelerator design and analysis: A compendium. Second edition

    International Nuclear Information System (INIS)

    Deaven, H.S.; Chan, K.C.D.

    1990-05-01

    The design of the next generation of high-energy accelerators will probably be done as an international collaborative efforts and it would make sense to establish, either formally or informally, an international center for accelerator codes with branches for maintenance, distribution, and consultation at strategically located accelerator centers around the world. This arrangement could have at least three beneficial effects. It would cut down duplication of effort, provide long-term support for the best codes, and provide a stimulating atmosphere for the evolution of new codes. It does not take much foresight to see that the natural evolution of accelerator design codes is toward the development of so-called Expert Systems, systems capable of taking design specifications of future accelerators and producing specifications for optimized magnetic transport and acceleration components, making a layout, and giving a fairly impartial cost estimate. Such an expert program would use present-day programs such as TRANSPORT, POISSON, and SUPERFISH as tools in the optimization process. Such a program would also serve to codify the experience of two generations of accelerator designers before it is lost as these designers reach retirement age. This document describes 203 codes that originate from 10 countries and are currently in use. The authors feel that this compendium will contribute to the dialogue supporting the international collaborative effort that is taking place in the field of accelerator physics today

  15. The Braunschweig accelerator facility for fast neutron research. 1: Building design and accelerators

    Science.gov (United States)

    Brede, H. J.; Cosack, M.; Dietze, G.; Gumpert, H.; Guldbakke, S.; Jahr, R.; Kutscha, M.; Schlegel-Bickmann, D.; Schölermann, H.

    1980-03-01

    A 3.75 MeV Van de Graaff generator and an energy variable isochronous cyclotron are used to produce "monoenergetic" neutrons with continuously variable energy between about 10 keV and 31.5 MeV. Both accelerators can be operated in a nanosecond pulsed beam mode, as needed for time-of-flight spectroscopy. Experiments can be performed in a low backscatter experimental hall. A heavy collimator system with five flight paths is mounted in a fixed position on the ground floor. The compact cyclotron is positioned on a swivel arm and can be moved for angular distribution measurements.

  16. Conceptual design of collective ion acceleration for pulsed neutron source

    International Nuclear Information System (INIS)

    Deng Renpei; Yang Maorong

    1998-12-01

    Theoretical and experimental analysis of the collective acceleration of ions (CIA) by an electron beam to obtain pulse neutron source in an evacuated drift tube are presented. The progress and development in the world laboratories are given too. According to the requirement, the plan of neutron source produced by CIA is investigated, with Marx generator, water dielectric Blumlein line, low impedance diode and drift tube. These devices' main parameters for neutron intensity of 10 9 neutrons/pulse are given

  17. Instructional Design for Accelerated Macrocognitive Expertise in the Baseball Workplace

    OpenAIRE

    Fadde, Peter J.

    2016-01-01

    The goal of accelerating expertise can leave researchers and trainers in human factors, naturalistic decision making, sport science, and expertise studies concerned about seemingly insufficient application of expert performance theories, findings and methods for training macrocognitive aspects of human performance. Video-occlusion methods perfected by sports expertise researchers have great instructional utility, in some cases offering an effective and inexpensive alternative to high-fidelity...

  18. HOM-Free Linear Accelerating Structure for e+ e- Linear Collider at C-Band

    CERN Document Server

    Kubo, K

    2003-01-01

    HOM-free linear acceleration structure using the choke mode cavity (damped cavity) is now under design for e sup + e sup - linear collider project at C-band frequency (5712 MHz). Since this structure shows powerful damping effect on most of all HOMs, there is no multibunch problem due to long range wakefields. The structure will be equipped with the microwave absorbers in each cells and also the in-line dummy load in the last few cells. The straightness tolerance for 1.8 m long structure is closer than 30 (micro)m for 25% emittance dilution limit, which can be achieved by standard machining and braising techniques. Since it has good vacuum pumping conductance through annular gaps in each cell, instabilities due to the interaction of beam with the residual-gas and ions can be minimized.

  19. Results of the RAMI analyses performed for the IFMIF accelerator facility in the engineering design phase

    Energy Technology Data Exchange (ETDEWEB)

    Bargalló, Enric, E-mail: enric.bargallo@esss.se [Fusion Energy Engineering Laboratory (FEEL), Technical University of Catalonia (UPC) Barcelona-Tech, Barcelona (Spain); Arroyo, Jose Manuel [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, Madrid (Spain); Abal, Javier; Dies, Javier; De Blas, Alfredo; Tapia, Carlos [Fusion Energy Engineering Laboratory (FEEL), Technical University of Catalonia (UPC) Barcelona-Tech, Barcelona (Spain); Moya, Joaquin; Ibarra, Angel [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, Madrid (Spain)

    2015-10-15

    Highlights: • RAMI methodology used for IFMIF accelerator facility is presented. • Availability analyses and results are shown. • Main accelerator design changes are proposed. • Consequences and conclusions of the RAMI analyses are described. - Abstract: This paper presents a summary of the RAMI (Reliability Availability Maintainability Inspectability) analyses done for the IFMIF (International Fusion Materials Irradiation Facility) Accelerator facility in the Engineering Design Phase. The methodology followed, the analyses performed, the results obtained and the conclusions drawn are described. Moreover, the consequences of the incorporation of the RAMI studies in the IFMIF design are presented and the main outcomes of these analyses are shown.

  20. Results of the RAMI analyses performed for the IFMIF accelerator facility in the engineering design phase

    International Nuclear Information System (INIS)

    Bargalló, Enric; Arroyo, Jose Manuel; Abal, Javier; Dies, Javier; De Blas, Alfredo; Tapia, Carlos; Moya, Joaquin; Ibarra, Angel

    2015-01-01

    Highlights: • RAMI methodology used for IFMIF accelerator facility is presented. • Availability analyses and results are shown. • Main accelerator design changes are proposed. • Consequences and conclusions of the RAMI analyses are described. - Abstract: This paper presents a summary of the RAMI (Reliability Availability Maintainability Inspectability) analyses done for the IFMIF (International Fusion Materials Irradiation Facility) Accelerator facility in the Engineering Design Phase. The methodology followed, the analyses performed, the results obtained and the conclusions drawn are described. Moreover, the consequences of the incorporation of the RAMI studies in the IFMIF design are presented and the main outcomes of these analyses are shown.

  1. Computing requirements for S.S.C. accelerator design and studies

    International Nuclear Information System (INIS)

    Dragt, A.; Talman, R.; Siemann, R.; Dell, G.F.; Leemann, B.; Leemann, C.; Nauenberg, U.; Peggs, S.; Douglas, D.

    1984-01-01

    We estimate the computational hardware resources that will be required for accelerator physics studies during the design of the Superconducting SuperCollider. It is found that both Class IV and Class VI facilities (1) will be necessary. We describe a user environment for these facilities that is desirable within the context of accelerator studies. An acquisition scenario for these facilities is presented

  2. The design and performance of Static Var Compensators for particle accelerators

    CERN Document Server

    Kahle, Karsten; Genton, Charles-Mathieu

    2015-01-01

    Particle accelerators, and in particular synchrotrons, represent large cycling non-linear loads connected to the electrical distribution network. This paper discusses the typical design and performance of Static Var Compensators (SVCs) to obtain the excellent power quality levels required for particle accelerator operation.

  3. Design of Multistable Origami Structures

    Science.gov (United States)

    Gillman, Andrew; Fuchi, Kazuko; Bazzan, Giorgio; Reich, Gregory; Alyanak, Edward; Buskohl, Philip

    Origami is being transformed from an art to a mathematically robust method for device design in a variety of scientific applications. These structures often require multiple stable configurations, e.g. efficient well-controlled deployment. However, the discovery of origami structures with mechanical instabilities is challenging given the complex geometric nonlinearities and the large design space to investigate. To address this challenge, we have developed a topology optimization framework for discovering origami fold patterns that realize stable and metastable positions. The objective function targets both the desired stable positions and nonlinear loading profiles of specific vertices in the origami structure. Multistable compliant structures have been shown to offer advantages in their stability and efficiency, and certain origami fold patterns exhibit multistable behavior. Building on this previous work of single vertex multistability analysis, e.g. waterbomb origami pattern, we are expanding the solution set of multistable mechanisms to include multiple vertices and a broader set of reference configurations. Collectively, these results enable an initial classification of geometry-induced mechanical instabilities that can be programmed into active material systems. This work was supported by the Air Force Office of Scientific Research.

  4. Optimization methods in structural design

    CERN Document Server

    Rothwell, Alan

    2017-01-01

    This book offers an introduction to numerical optimization methods in structural design. Employing a readily accessible and compact format, the book presents an overview of optimization methods, and equips readers to properly set up optimization problems and interpret the results. A ‘how-to-do-it’ approach is followed throughout, with less emphasis at this stage on mathematical derivations. The book features spreadsheet programs provided in Microsoft Excel, which allow readers to experience optimization ‘hands-on.’ Examples covered include truss structures, columns, beams, reinforced shell structures, stiffened panels and composite laminates. For the last three, a review of relevant analysis methods is included. Exercises, with solutions where appropriate, are also included with each chapter. The book offers a valuable resource for engineering students at the upper undergraduate and postgraduate level, as well as others in the industry and elsewhere who are new to these highly practical techniques.Whi...

  5. Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy.

    Science.gov (United States)

    Vento, V Thatar; Bergueiro, J; Cartelli, D; Valda, A A; Kreiner, A J

    2011-12-01

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Horizon structure of rotating Bardeen black hole and particle acceleration

    International Nuclear Information System (INIS)

    Ghosh, Sushant G.; Amir, Muhammed

    2015-01-01

    We investigate the horizon structure and ergosphere in a rotating Bardeen regular black hole, which has an additional parameter (g) due to the magnetic charge, apart from the mass (M) and the rotation parameter (a). Interestingly, for each value of the parameter g, there exists a critical rotation parameter (a = a E ), which corresponds to an extremal black hole with degenerate horizons, while for a < a E it describes a non-extremal black hole with two horizons, and no black hole for a > a E . We find that the extremal value a E is also influenced by the parameter g, and so is the ergosphere. While the value of a E remarkably decreases when compared with the Kerr black hole, the ergosphere becomes thicker with the increase in g.We also study the collision of two equal mass particles near the horizon of this black hole, and explicitly show the effect of the parameter g. The center-of-mass energy (E CM ) not only depend on the rotation parameter a, but also on the parameter g. It is demonstrated that the E CM could be arbitrarily high in the extremal cases when one of the colliding particles has a critical angular momentum, thereby suggesting that the rotating Bardeen regular black hole can act as a particle accelerator. (orig.)

  7. High Power Test of X-band Single Cell HOM-free Choke-mode Damped Accelerating Structure made by Tsinghua University

    OpenAIRE

    Wu, Xiaowei; Abe, Tetsuo; Chen, Huaibi; Higo, Toshiyasu; Shi, Jiaru; Wuensch, Walter; Zha, Hao

    2016-01-01

    As an alternative design for CLIC main accelerating structures, X-band choke-mode damped structures had been studied for several years. However, the performance of choke-mode cavity under high power is still in lack of research. Two standing wave single cell choke-mode damped accelerating structures with different choke dimensions which are working at 11.424 GHz were designed, manufactured and bench tested by accelerator group in Tsinghua University. High power test was carried out on it to s...

  8. High-gradient low-β accelerating structure using the first negative spatial harmonic of the fundamental mode

    Science.gov (United States)

    Kutsaev, Sergey V.; Agustsson, Ronald; Boucher, Salime; Fischer, Richard; Murokh, Alex; Mustapha, Brahim; Nassiri, Alireza; Ostroumov, Peter N.; Plastun, Alexander; Savin, Evgeny; Smirnov, Alexander Yu.

    2017-12-01

    The development of high-gradient accelerating structures for low-β particles is the key for compact hadron linear accelerators. A particular example of such a machine is a hadron therapy linac, which is a promising alternative to cyclic machines, traditionally used for cancer treatment. Currently, the practical utilization of linear accelerators in radiation therapy is limited by the requirement to be under 50 m in length. A usable device for cancer therapy should produce 200-250 MeV protons and/or 400 - 450 MeV /u carbon ions, which sets the requirement of having 35 MV /m average "real-estate gradient" or gradient per unit of actual accelerator length, including different accelerating sections, focusing elements and beam transport lines, and at least 50 MV /m accelerating gradients in the high-energy section of the linac. Such high accelerating gradients for ion linacs have recently become feasible for operations at S-band frequencies. However, the reasonable application of traditional S-band structures is practically limited to β =v /c >0.4 . However, the simulations show that for lower phase velocities, these structures have either high surface fields (>200 MV /m ) or low shunt impedances (issue, we have designed a novel radio frequency structure where the beam is synchronous with the higher spatial harmonic of the electromagnetic field. In this paper, we discuss the principles of this approach, the related beam dynamics and especially the electromagnetic and thermomechanical designs of this novel structure. Besides the application to ion therapy, the technology described in this paper can be applied to future high gradient normal conducting ion linacs and high energy physics machines, such as a compact hadron collider. This approach preserves linac compactness in settings with limited space availability.

  9. A novel stereotactic device for spinal irradiation in rats designed for a linear accelerator.

    Science.gov (United States)

    Galván, Ernesto E; Lárraga-Gutiérrez, José M; Celis, Miguel Angel; Moreno-Jiménez, Sergio; Díaz-Ruiz, Araceli; Rios, Camilo

    2010-01-01

    Our purpose was to report the design and positioning accuracy testing of a stereotactic device designed for a linear accelerator to perform spinal radiosurgery in rats. To define the spatial and repositioning accuracy of the device, we measured the 3-dimensional (3D) translation of a paraspinal fiducial mark implanted by microsurgery in 5 Wistar rats during a sequence of setups and treatment simulations, thus obtaining final 3D translation vectors and maximum displacements. For spatial accuracy, the differential coordinate translations were 0.8 +/- 0.3, 0.6 +/- 0.2 and 0.5 +/- 0.1 mm in the x-, y- and z-directions, respectively. The median magnitude of the 3D vector was 1.3 mm (sigma = 0.2 mm), with a maximum error of 2.2 mm. The differential coordinate translation for the repositioning accuracy showed values of 1.4 +/- 0.3, 1.3 +/- 0.3 and 0.8 +/- 0.1 mm for the x-, y- and z-coordinates, resulting in a 3D displacement vector of 2.2 mm (sigma = 0.2 mm) and a maximum displacement error of 3.6 mm. Using a linear accelerator, our novel stereotactic device provides accurate immobilization and repositioning of paraspinal structures under experimental conditions in rats. (c) 2010 S. Karger AG, Basel.

  10. Fabrication Technologies of the High Gradient Accelerator Structures at 100MV/m Range

    CERN Document Server

    Wang, Juwen; Van Pelt, John; Yoneda, Charles; Gudkov, D; Riddone, Germana; Higo, Toshiyasu; Takatomi, Toshikazu

    2010-01-01

    A CERN-SLAC-KEK collaboration on high gradient X-band structure research has been established in order to demonstrate the feasibility of the CLIC baseline design for the main linac stably operating at more than 100 MV/m loaded accelerating gradient. Several prototype CLIC structures were successfully fabricated and high power tested. They operated at 105 MV/m with a breakdown rate that meets the CLIC linear collider specifications of <5×10-7/pulse/m. This paper summarizes the fabrication technologies including the mechanical design, precision machining, chemical cleaning, diffusion bonding as well as vacuum baking and all related assembly technologies. Also, the tolerances control, tuning and RF characterization will be discussed

  11. Fabrication Technologies of the High Gradient Accelerator Structures at 100MV/M Range

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Juwen; /SLAC; Lewandowski, James; /SLAC; Van Pelt, John; /SLAC; Yoneda, Charles; /SLAC; Gudkov, Boris; /CERN; Riddone, Germana; /CERN; Higo, Toshiyasu; /KEK, Tsukuba; Takatomi, Toshikazu; /KEK, Tsukuba

    2012-07-03

    A CERN-SLAC-KEK collaboration on high gradient X-band structure research has been established in order to demonstrate the feasibility of the CLIC baseline design for the main linac stably operating at more than 100 MV/m loaded accelerating gradient. Several prototype CLIC structures were successfully fabricated and high power tested. They operated at 105 MV/m with a breakdown rate that meets the CLIC linear collider specifications of < 5 x 10{sup -7}/pulse/m. This paper summarizes the fabrication technologies including the mechanical design, precision machining, chemical cleaning, diffusion bonding as well as vacuum baking and all related assembly technologies. Also, the tolerances control, tuning and RF characterization will be discussed.

  12. SwissFEL injector conceptual design report. Accelerator test facility for SwissFEL

    International Nuclear Information System (INIS)

    Pedrozzi, M.

    2010-07-01

    This comprehensive report issued by the Paul Scherrer Institute (PSI) in Switzerland takes a look at the design concepts behind the institute's SwissFEL X-ray Laser facility - in particular concerning the conceptual design of the injector system. The SwissFEL X-ray FEL project at PSI, involves the development of an injector complex that enables operation of a FEL system operating at 0.1 - 7 nm with permanent-magnet undulator technology and minimum beam energy. The injector pre-project was motivated by the challenging electron beam requirements necessary to drive the SwissFEL accelerator facility. The report takes a look at the mission of the test facility and its performance goals. The accelerator layout and the electron source are described, as are the low-level radio-frequency power systems and the synchronisation concept. The general strategy for beam diagnostics is introduced. Low energy electron beam diagnostics, the linear accelerator (Linac) and bunch compressor diagnostics are discussed, as are high-energy electron beam diagnostics. Wavelength selection for the laser system and UV pulse shaping are discussed. The laser room for the SwissFEL Injector and constructional concepts such as the girder system and alignment concepts involved are looked at. A further chapter deals with beam dynamics, simulated performance and injector optimisation. The facility's commissioning and operation program is examined, as are operating regimes, software applications and data storage. The control system structure and architecture is discussed and special subsystems are described. Radiation safety, protection systems and shielding calculations are presented and the lateral shielding of the silo roof examined

  13. Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures

    Energy Technology Data Exchange (ETDEWEB)

    Byer, Robert L. [Stanford Univ., CA (United States). Edward L. Ginzton Lab.

    2013-11-07

    The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

  14. Jacobs Engineering Group Inc. receives architectural and engineering design contract from Stanford Linear Accelerator Centre

    CERN Multimedia

    2004-01-01

    "Jacobs Engineering Group Inc. announced that a subsidiary company won a contract from Stanford Linear Accelerator Center (SLAC), to provide architectural and engineering design services for the Linac Coherent Light Source (LCLS) conventional facilities" (1/2 page)

  15. FPGA accelerator for protein secondary structure prediction based on the GOR algorithm.

    Science.gov (United States)

    Xia, Fei; Dou, Yong; Lei, Guoqing; Tan, Yusong

    2011-02-15

    Protein is an important molecule that performs a wide range of functions in biological systems. Recently, the protein folding attracts much more attention since the function of protein can be generally derived from its molecular structure. The GOR algorithm is one of the most successful computational methods and has been widely used as an efficient analysis tool to predict secondary structure from protein sequence. However, the execution time is still intolerable with the steep growth in protein database. Recently, FPGA chips have emerged as one promising application accelerator to accelerate bioinformatics algorithms by exploiting fine-grained custom design. In this paper, we propose a complete fine-grained parallel hardware implementation on FPGA to accelerate the GOR-IV package for 2D protein structure prediction. To improve computing efficiency, we partition the parameter table into small segments and access them in parallel. We aggressively exploit data reuse schemes to minimize the need for loading data from external memory. The whole computation structure is carefully pipelined to overlap the sequence loading, computing and back-writing operations as much as possible. We implemented a complete GOR desktop system based on an FPGA chip XC5VLX330. The experimental results show a speedup factor of more than 430x over the original GOR-IV version and 110x speedup over the optimized version with multi-thread SIMD implementation running on a PC platform with AMD Phenom 9650 Quad CPU for 2D protein structure prediction. However, the power consumption is only about 30% of that of current general-propose CPUs.

  16. Material studies in the frame of CLIC Accelerating structures production conducted within the Mechanics program together with Metso Oy

    CERN Document Server

    Nurminen, Janne

    2012-01-01

    MeChanICs (Marie Curie Linking Industry to CERN) is an Industry to Academia Partnership and Pathways (IAPP) platform for precision manufacturing knowledge exchange bringing together five Finnish manufacturing companies with Helsinki Insitute of Physics (HIP) and CERN. The scientific objective of MeChanICs project is to contribute to the manufacturing RTD of CLIC enabling technologies. The focus is on the design, materials, machining, brazing and assembly of A CLIC accelerating structure. This study deals with the materials work package of the program and wants to explore the following items: 1) producing copper accelerating structures for CLIC from raw copper powder by near net shape hot isostatic pressing (HIP). 2) The feasibility to use HIP diffusion bonding of the accelerator structures as a function of surface quality and applied temperature and pressure. 3) Brazing for CLIC AS auxiliary systems, like water cooling or damping manifolds, to the disc stack by coating one of the brazing partners with an enab...

  17. The Simulation Calculations And Dielectric Characteristics Investigation of a Hybrid Dielectric-Iris-Loaded Travelling Accelerating Structure

    CERN Document Server

    Wu, C F

    2004-01-01

    Mafia code has been used to calculate the RF properties versus the geometric parameters and dielectric permittivity of the X-band (f=9.37 GHz) hybrid dielectric-iris-loaded travelling accelerating structure. The simulation results show that when the range of the permittivity is about 5–9 and the geometric parameters are optimized, the new structure may have lower ratio (about 1) of peak surface electric field at the iris to axial accelerating electric field , while r, Q, r/Q of the new structure being comparable to iris-loaded accelerating structure. The experimental investigation of the permittivity of the dielectric (ceramic)has been made by using the cavity perturbation technique. The results show that the permittivity of the ceramic is about 5.8 at the X-band and its stability is good.The above results will be applied to the design of the new accelerating structure, which may be a potential candidate of high gradient Linear accelerator.

  18. Preliminary Structural Design - Defining the Design Space

    Science.gov (United States)

    1993-02-01

    space (where the feasible design space is an n-dimensional "volume"). The dimension of the hyperspace relates to the number of design variables, and...unobtainable from current design procedures. It was pointed out earlier that a hyperspace can be imagined for which each point in that space...other features that make this investigation desirable: • It is robust and fault tolerant. Nerve cells in the brain die every day without affecting its

  19. High-Gradient test results from a CLIC prototype accelerating structure : TD26CC

    CERN Document Server

    Degiovanni, A; Farabolini, W; Grudiev, A; Kovermann, J; Montessinos, E; Riddone, G; Syratchev, I; Wegner, R; Wuensch, W; Solodko, A; Woolley, B

    2014-01-01

    The CLIC study has progressively tested prototype accelerating structures which incorporate an ever increasing number of features which are needed for a final version ready to be installed in a linear collider. The most recent high power test made in the CERN X-band test stand, Xbox-1, is of a CERN-built prototype which includes damping features but also compact input and output power couplers, which maximize the overall length to active gradient ratio of the structure. The structure’s high-gradient performance, 105 MV/m at 250 ns pulse length and low breakdown rate, matches previously tested structures validating both CERN fabrication and the compact coupler design.

  20. Digital computer structure and design

    CERN Document Server

    Townsend, R

    2014-01-01

    Digital Computer Structure and Design, Second Edition discusses switching theory, counters, sequential circuits, number representation, and arithmetic functions The book also describes computer memories, the processor, data flow system of the processor, the processor control system, and the input-output system. Switching theory, which is purely a mathematical concept, centers on the properties of interconnected networks of ""gates."" The theory deals with binary functions of 1 and 0 which can change instantaneously from one to the other without intermediate values. The binary number system is

  1. DEVELOPING THE PHYSICS DESIGN FOR NDCX-II, A UNIQUE PULSE-COMPRESSING ION ACCELERATOR

    International Nuclear Information System (INIS)

    Friedman, A.; Barnard, J.J.; Cohen, R.H.; Grote, D.P.; Lund, S.M.; Sharp, W.M.; Faltens, A.; Henestroza, E.; Jung, J.-Y.; Kwan, J.W.; Lee, E.P.; Leitner, M.A.; Logan, B.G.; Vay, J.-L.; Waldron, W.L.; Davidson, R.C.; Dorf, M.; Gilson, E.P.; Kaganovich, I.

    2009-01-01

    The Heavy Ion Fusion Science Virtual National Laboratory (a collaboration of LBNL, LLNL, and PPPL) is using intense ion beams to heat thin foils to the 'warm dense matter' regime at ∼ + ions to ∼1 ns while accelerating it to 3-4 MeV over ∼15 m. Strong space charge forces are incorporated into the machine design at a fundamental level. We are using analysis, an interactive 1D PIC code (ASP) with optimizing capabilities and centroid tracking, and multi-dimensional Warpcode PIC simulations, to develop the NDCX-II accelerator. This paper describes the computational models employed, and the resulting physics design for the accelerator.

  2. A rational evaluation of structural design loads

    International Nuclear Information System (INIS)

    Tasaka, S.

    1993-01-01

    The reliability-based seismic design of structures is a design method ensuring that the structural seismic capacity is not less than the maximum seismic load or load effect for a prescribed value of the reliability index, wherein the design reference period, n, is used to specify the n-year maximum load. In the conventional Load and Resistance Factor Design (LRFD) method the design load is commonly determined on the basis of the n-year maximum the probability distribution of which may be given in some different ways. However, in contrast with the structural capacity the n-year maximum load usually involves much larger variabilities. The effort to decrease the variability would, hence, be effective for the purpose of avoiding nuclear power plant (NPP) structures having unnecessarily large capacities. A possible way to do this is to consider the joint probability distribution of the n-year 1st and 2nd maxima of the seismic load derived from the formula of extreme order statistics. Since the reliability index is conventionally associated with the n-year 1st maximum, the conditional probability distribution rather than the joint one of the n-year 1st maximum given a value of the n-year 2nd one will be considered. Three conditional extreme value distributions, which correspond to the usual extreme value distributions of Types I, II and III, and their statistical moments up to the second order are presented. Within the framework of the first-order second moment method, the conditional statistical moments are utilized to calculate the reliability index as well as the design value of the seismic load. The seismic load considered herein is represented by the peak ground acceleration (PGA) in n years. The present scheme is applied to evaluate the design PGA's at II sites in Japan where samples of the annual 1st and 2nd PGA's have been obtained by using historical seismic data. In this application the following two points are of our interest: (a) Define the reliability

  3. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure

    Science.gov (United States)

    Munroe, Brian J.; Zhang, JieXi; Xu, Haoran; Shapiro, Michael A.; Temkin, Richard J.

    2016-03-01

    We report the design, fabrication, and high gradient testing of a 17.1 GHz photonic band-gap (PBG) accelerator structure. Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox) input and output cells, with input power of up to 4 MW from a klystron supplied via a TM01 mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87 MV /m at a breakdown probability of 1.19 ×10-1 per pulse per meter. The PBG structure was tested with 100 ns pulses at gradient levels of less than 90 MV /m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89 MV /m at a breakdown probability of 1.09 ×10-1 per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.

  4. AEi systems designing power sstem for world's largest particle accelerator

    CERN Multimedia

    Weinberg, Lee

    2007-01-01

    "AEi Systems, a world leader in power systems analysis and design, announced today that the Large Hadron Collider (LHC) at CERN (the European Centre for Nuclear Research) near Geneva, Switzerland, has engaged AEi Systems to design and develop a radiation-hard power supply for CERN's giant ATLAS particle detector." (1 page)

  5. GPU-accelerated CFD Simulations for Turbomachinery Design Optimization

    NARCIS (Netherlands)

    Aissa, M.H.

    2017-01-01

    Design optimization relies heavily on time-consuming simulations, especially when using gradient-free optimization methods. These methods require a large number of simulations in order to get a remarkable improvement over reference designs, which are nowadays based on the accumulated engineering

  6. Accelerating Families of Fuzzy K-Means Algorithms for Vector Quantization Codebook Design.

    Science.gov (United States)

    Mata, Edson; Bandeira, Silvio; de Mattos Neto, Paulo; Lopes, Waslon; Madeiro, Francisco

    2016-11-23

    The performance of signal processing systems based on vector quantization depends on codebook design. In the image compression scenario, the quality of the reconstructed images depends on the codebooks used. In this paper, alternatives are proposed for accelerating families of fuzzy K-means algorithms for codebook design. The acceleration is obtained by reducing the number of iterations of the algorithms and applying efficient nearest neighbor search techniques. Simulation results concerning image vector quantization have shown that the acceleration obtained so far does not decrease the quality of the reconstructed images. Codebook design time savings up to about 40% are obtained by the accelerated versions with respect to the original versions of the algorithms.

  7. Accelerating Families of Fuzzy K-Means Algorithms for Vector Quantization Codebook Design

    Directory of Open Access Journals (Sweden)

    Edson Mata

    2016-11-01

    Full Text Available The performance of signal processing systems based on vector quantization depends on codebook design. In the image compression scenario, the quality of the reconstructed images depends on the codebooks used. In this paper, alternatives are proposed for accelerating families of fuzzy K-means algorithms for codebook design. The acceleration is obtained by reducing the number of iterations of the algorithms and applying efficient nearest neighbor search techniques. Simulation results concerning image vector quantization have shown that the acceleration obtained so far does not decrease the quality of the reconstructed images. Codebook design time savings up to about 40% are obtained by the accelerated versions with respect to the original versions of the algorithms.

  8. PIMS—A simple and robust accelerating structure for high intensity proton Linacs

    CERN Document Server

    Wegner, F

    2009-01-01

    A π-mode structure (PIMS) is investigated for an application in a high duty cycle, high intensity proton Linac. Motivated by the objective to employ a simple and robust accelerating structure at a resonance frequency of 352 MHz for the high energy part of Linac4 (100–160 MeV), the normal conducting LEP cavity is restudied and its design is adopted for a medium application. The geometry of the accelerating cell is optimised, the necessary cell-to-cell coupling coefficient is analysed and a novel solution for the shape of the coupling slots is discussed. Simulation results are compared to measurement results obtained from three 3-cell cold models and one 7-cell cold model. The method of tuning the resonance frequency of individual cells is presented and the tuning of end cells is explained in detail. An adjustable wave guide coupler is used to power the cavities, and we present the design process for this device. The behaviour of the PIMS to dynamical changes—as observed during the filling process of the c...

  9. 46 CFR 116.300 - Structural design.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Structural design. 116.300 Section 116.300 Shipping... Structure § 116.300 Structural design. Except as otherwise allowed by this subpart, a vessel must comply with the structural design requirements of one of the standards listed below for the hull material of...

  10. 46 CFR 177.300 - Structural design.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Structural design. 177.300 Section 177.300 Shipping...) CONSTRUCTION AND ARRANGEMENT Hull Structure § 177.300 Structural design. Except as otherwise allowed by this subpart, a vessel must comply with the structural design requirements of one of the standards listed below...

  11. Thermally Induced Ultra High Cycle Fatigue of Copper Alloys of the High Gradient Accelerating Structures

    CERN Document Server

    Heikkinen, Samuli; Wuensch, Walter

    2010-01-01

    In order to keep the overall length of the compact linear collider (CLIC), currently being studied at the European Organization for Nuclear Research (CERN), within reasonable limits, i.e. less than 50 km, an accelerating gradient above 100 MV/m is required. This imposes considerable demands on the materials of the accelerating structures. The internal surfaces of these core components of a linear accelerator are exposed to pulsed radio frequency (RF) currents resulting in cyclic thermal stresses expected to cause surface damage by fatigue. The designed lifetime of CLIC is 20 years, which results in a number of thermal stress cycles of the order of 2.33•1010. Since no fatigue data existed in the literature for CLIC parameter space, a set of three complementary experiments were initiated: ultra high cycle mechanical fatigue by ultrasound, low cycle fatigue by pulsed laser irradiation and low cycle thermal fatigue by high power microwaves, each test representing a subset of the original problem. High conductiv...

  12. Fine-grained parallelism accelerating for RNA secondary structure prediction with pseudoknots based on FPGA.

    Science.gov (United States)

    Xia, Fei; Jin, Guoqing

    2014-06-01

    PKNOTS is a most famous benchmark program and has been widely used to predict RNA secondary structure including pseudoknots. It adopts the standard four-dimensional (4D) dynamic programming (DP) method and is the basis of many variants and improved algorithms. Unfortunately, the O(N(6)) computing requirements and complicated data dependency greatly limits the usefulness of PKNOTS package with the explosion in gene database size. In this paper, we present a fine-grained parallel PKNOTS package and prototype system for accelerating RNA folding application based on FPGA chip. We adopted a series of storage optimization strategies to resolve the "Memory Wall" problem. We aggressively exploit parallel computing strategies to improve computational efficiency. We also propose several methods that collectively reduce the storage requirements for FPGA on-chip memory. To the best of our knowledge, our design is the first FPGA implementation for accelerating 4D DP problem for RNA folding application including pseudoknots. The experimental results show a factor of more than 50x average speedup over the PKNOTS-1.08 software running on a PC platform with Intel Core2 Q9400 Quad CPU for input RNA sequences. However, the power consumption of our FPGA accelerator is only about 50% of the general-purpose micro-processors.

  13. Status of the 1 MeV Accelerator Design for ITER NBI

    Science.gov (United States)

    Kuriyama, M.; Boilson, D.; Hemsworth, R.; Svensson, L.; Graceffa, J.; Schunke, B.; Decamps, H.; Tanaka, M.; Bonicelli, T.; Masiello, A.; Bigi, M.; Chitarin, G.; Luchetta, A.; Marcuzzi, D.; Pasqualotto, R.; Pomaro, N.; Serianni, G.; Sonato, P.; Toigo, V.; Zaccaria, P.; Kraus, W.; Franzen, P.; Heinemann, B.; Inoue, T.; Watanabe, K.; Kashiwagi, M.; Taniguchi, M.; Tobari, H.; De Esch, H.

    2011-09-01

    The beam source of neutral beam heating/current drive system for ITER is needed to accelerate the negative ion beam of 40A with D- at 1 MeV for 3600 sec. In order to realize the beam source, design and R&D works are being developed in many institutions under the coordination of ITER organization. The development of the key issues of the ion source including source plasma uniformity, suppression of co-extracted electron in D beam operation and also after the long beam duration time of over a few 100 sec, is progressed mainly in IPP with the facilities of BATMAN, MANITU and RADI. In the near future, ELISE, that will be tested the half size of the ITER ion source, will start the operation in 2011, and then SPIDER, which demonstrates negative ion production and extraction with the same size and same structure as the ITER ion source, will start the operation in 2014 as part of the NBTF. The development of the accelerator is progressed mainly in JAEA with the MeV test facility, and also the computer simulation of beam optics also developed in JAEA, CEA and RFX. The full ITER heating and current drive beam performance will be demonstrated in MITICA, which will start operation in 2016 as part of the NBTF.

  14. Designing safer composite helmets to reduce rotational accelerations during oblique impacts.

    Science.gov (United States)

    Mosleh, Yasmine; Cajka, Martin; Depreitere, Bart; Vander Sloten, Jos; Ivens, Jan

    2018-03-01

    Oblique impact is the most common accident situation that occupants in traffic accidents or athletes in professional sports experience. During oblique impact, the human head is subjected to a combination of linear and rotational accelerations. Rotational movement is known to be responsible for traumatic brain injuries. In this article, composite foam with a column/matrix composite configuration is proposed for head protection applications to replace single-layer uniform foam, to better attenuate rotational movement of the head during oblique impacts. The ability of composite foam in the mitigation of rotational head movement is studied by performing finite element (FE) simulations of oblique impact on flat and helmet shape specimens. The performance of composite foam with respect to parameters such as compliance of the matrix foam and the number, size and cross-sectional shape of the foam columns is explored in detail, and subsequently an optimized structure is proposed. The simulation results show that using composite foam instead of single-layer foam, the rotational acceleration and velocity of the headform can be significantly reduced. The parametric study indicates that using a more compliant matrix foam and by increasing the number of columns in the composite foam configuration, the rotation can be further mitigated. This was confirmed by experimental results. The simulation results were also analyzed based on global head injury criteria such as head injury criterion, rotational injury criterion, brain injury criterion and generalized acceleration model for brain injury threshold which further confirmed the superior performance of composite foam versus single-layer homogeneous expanded polystyrene foam. The findings of simulations give invaluable information for design of protective helmets or, for instance, headliners for the automotive industry.

  15. Accelerate!

    Science.gov (United States)

    Kotter, John P

    2012-11-01

    The old ways of setting and implementing strategy are failing us, writes the author of Leading Change, in part because we can no longer keep up with the pace of change. Organizational leaders are torn between trying to stay ahead of increasingly fierce competition and needing to deliver this year's results. Although traditional hierarchies and managerial processes--the components of a company's "operating system"--can meet the daily demands of running an enterprise, they are rarely equipped to identify important hazards quickly, formulate creative strategic initiatives nimbly, and implement them speedily. The solution Kotter offers is a second system--an agile, networklike structure--that operates in concert with the first to create a dual operating system. In such a system the hierarchy can hand off the pursuit of big strategic initiatives to the strategy network, freeing itself to focus on incremental changes to improve efficiency. The network is populated by employees from all levels of the organization, giving it organizational knowledge, relationships, credibility, and influence. It can Liberate information from silos with ease. It has a dynamic structure free of bureaucratic layers, permitting a level of individualism, creativity, and innovation beyond the reach of any hierarchy. The network's core is a guiding coalition that represents each level and department in the hierarchy, with a broad range of skills. Its drivers are members of a "volunteer army" who are energized by and committed to the coalition's vividly formulated, high-stakes vision and strategy. Kotter has helped eight organizations, public and private, build dual operating systems over the past three years. He predicts that such systems will lead to long-term success in the 21st century--for shareholders, customers, employees, and companies themselves.

  16. Design alternatives for beam halo monitors in high intensity accelerators

    CERN Document Server

    Braun, H; Corsini, R; Lefèvre, T; Schulte, Daniel; Tecker, F A; Welsch, C P

    2005-01-01

    In future high intensity, high energy accelerators it must be ensured that particle losses are minimized as activation of the vacuum chambers or other components makes maintenance and upgrade work time consuming and costly. It is imperative to have a clear understanding of the mechanisms that can lead to halo formation and to have the possibility to test available theoretical models with an adequate experimental setup. Optical transition radiation (OTR) provides an interesting opportunity for linear real-time measurements of the transverse beam profile with a resolution which has been so far at best in the some μm range. However, the dynamic range of standard OTR systems is typically limited and needs to be improved for its application for halo measurements. In this contribution, the existing OTR system as it is installed in the CLIC test facility (CTF3) is analyzed and the contribution of each component to the final image quality discussed. Finally, possible halo measurement techniques based on OTR are pres...

  17. Linear Accelerator Test Facility at LNF Conceptual Design Report

    CERN Document Server

    Valente, Paolo; Bolli, Bruno; Buonomo, Bruno; Cantarella, Sergio; Ceccarelli, Riccardo; Cecchinelli, Alberto; Cerafogli, Oreste; Clementi, Renato; Di Giulio, Claudio; Esposito, Adolfo; Frasciello, Oscar; Foggetta, Luca; Ghigo, Andrea; Incremona, Simona; Iungo, Franco; Mascio, Roberto; Martelli, Stefano; Piermarini, Graziano; Sabbatini, Lucia; Sardone, Franco; Sensolini, Giancarlo; Ricci, Ruggero; Rossi, Luis Antonio; Rotundo, Ugo; Stella, Angelo; Strabioli, Serena; Zarlenga, Raffaele

    2016-01-01

    Test beam and irradiation facilities are the key enabling infrastructures for research in high energy physics (HEP) and astro-particles. In the last 11 years the Beam-Test Facility (BTF) of the DA{\\Phi}NE accelerator complex in the Frascati laboratory has gained an important role in the European infrastructures devoted to the development and testing of particle detectors. At the same time the BTF operation has been largely shadowed, in terms of resources, by the running of the DA{\\Phi}NE electron-positron collider. The present proposal is aimed at improving the present performance of the facility from two different points of view: extending the range of application for the LINAC beam extracted to the BTF lines, in particular in the (in some sense opposite) directions of hosting fundamental physics and providing electron irradiation also for industrial users; extending the life of the LINAC beyond or independently from its use as injector of the DA{\\Phi}NE collider, as it is also a key element of the electron/...

  18. Superconducting accelerator technology

    International Nuclear Information System (INIS)

    Grunder, H.A.; Hartline, B.K.

    1986-01-01

    Modern and future accelerators for high energy and nuclear physics rely increasingly on superconducting components to achieve the required magnetic fields and accelerating fields. This paper presents a practical overview of the phenomenon of superconductivity, and describes the design issues and solutions associated with superconducting magnets and superconducting rf acceleration structures. Further development and application of superconducting components promises increased accelerator performance at reduced electric power cost

  19. Design and Development of RF Structures for Linac4

    CERN Document Server

    Vretenar, M; Gerigk, F; Pasini, M; Wegner, R

    2006-01-01

    Linac4 is a new 160 MeV H− linac proposed at CERN to replace the 50 MeV Linac2 as injector to the PS Booster, with the goal of doubling its brightness and intensity. The present design foresees after RFQ and chopping line a sequence of three accelerating structures: a Drift Tube Linac (DTL) from 3 to 40 MeV, a Cell-Coupled DTL (CCDTL) to 90 MeV and a Side Coupled Linac (SCL) up to the final energy. The DTL and CCDTL operate at 352 MHz, while in the SCL the frequency is doubled to 704 MHz. Although the injection in the PS Booster requires only a low duty cycle, the accelerating structures are designed to operate at the high duty cycle required by a possible future extension to a high-power linac driver for a neutrino facility. This paper presents the different accelerating structures, underlining the progress in the design of critical resonator elements, like post-couplers in the DTL, coupling slots in the CCDTL and bridge couplers for the SCL. Prototyping progress for the different structures is reported...

  20. Auroral ion acceleration from lower hybrid solitary structures: A summary of sounding rocket observations

    Science.gov (United States)

    Lynch, K. A.; Arnoldy, R. L.; Kintner, P. M.; Schuck, P.; Bonnell, J. W.; Coffey, V.

    In this paper we present a review of sounding rocket observations of the ion acceleration seen in nightside auroral zone lower hybrid solitary structures. Observations from Topaz3, Amicist, and Phaze2 are presented on various spatial scales, including the two-point measurements of the Amicist mission. From this collection of observations we will demonstrate the following characteristics of transverse acceleration of ions (TAI) in lower hybrid solitary structures (LHSS). The ion acceleration process is narrowly confined to 90° pitch angle, in spatially confined regions of up to a few hundred meters across B. The acceleration process does not affect the thermal core of the ambient distribution and does not directly create a measurable effect on the ambient ion population outside the LHSS themselves. This precludes observation with these data of any nonlinear feedback between the ion acceleration and the existence or evolution of the density irregularities on which these LHSS events grow. Within the LHSS region the acceleration process creates a high-energy tail beginning at a few times the thermal ion speed. The ion acceleration events are closely associated with localized wave events. Accelerated ions bursts are also seen without a concurrent observation of a localized wave event, for two possible reasons. In some cases, the pitch angles of the accelerated tail ions are elevated above perpendicular; that is, the acceleration occurred below the observer and the mirror force has begun to act upon the distribution, moving it upward from the source. In other cases, the accelerated ion structure is spatially larger than the wave event structure, and the observation catches only the ion event. The occurrence rate of these ion acceleration events is related to the ambient environment in two ways: its altitude dependence can be modeled with the parameter B2/ne, and it is highest in regions of intense VLF activity. The cumulative ion outflow from these LHSS TAI is

  1. Design of 10 MeV cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    R Solhju

    2015-09-01

    Full Text Available Design and construction of 10MeV cyclotron has been started at Amirkabir University of Technology since 2012. So far, the conceptual and detail engineering design phases have been finalized. The main purpose of this baby cyclotron is to generate proton beam for the production of PET radioisotopes. The cyclotron consists of magnet, cavity, ion source, RF and LLRF system, vacuum system, cooling system, power amplifiers and power supplies system. In this paper, a brief of design principles for all the parts of cyclotron and their final simulation results is presented. It should be noted that these simulations have been performed and optimized by the most accurate softwares such as TOSCA, ANSYS, HFSS, SolidWorks and CST. Also, the manufacturing feasibility of all the parts is performed and their dimensions and parameters are synchronized with manufacturing standards

  2. High Gradient Performance of NLC/GLC X-Band Accelerating Structures

    CERN Document Server

    Döbert, Steffen; Boffo, Cristian; Bowden, Gordon B; Burke, David; Carter, Harry; Chan, Jose; Dolgashev, Valery A; Frisch, Josef; Funahashi, Y; Gonin, Ivan V; Hayano, Hitoshi; Higashi, Norio; Higashi, Yasuo; Higo, Toshiyasu; Jobe, R Keith; Jones, Roger M; Kawamata, H; Khabiboulline, Timergali N; Kirby, Robert; Kume, T; Lewandowski, James R; Li, Zenghai; McCormick, Douglas; Miller, Roger H; Mishra, Shekhar; Morozumi, Yuichi; Nantista, Christopher D; Nelson, Janice; Pearson, Chris; Romanov, Gennady; Ross, Marc; Schultz, David; Smith, Tonee; Solyak, Nikolay; Tacku Arkan, Tug; Takata, Koji; Takatomi, Toshikazu; Tantawi, Sami G; Toge, Nobu; Ueno, K; Wang, Juwen W; Watanabe, Y

    2005-01-01

    During the past five years, there has been an concerted effort at FNAL, KEK and SLAC to develop accelerator structures that meet the high gradient performance requirements for the Next Linear Collider (NLC) and Global Linear Collider (GLC) initiatives. The structure that resulted is a 60-cm-long, traveling-wave design with low group velocity (< 4% c) and a 150 degree phase advance per cell. It has an average iris size that produces an acceptable short-range wakefield in the linacs, and dipole mode damping and detuning that adequately suppresses the long-range wakefield. More than eight such structures have operated over 1000 hours at a 60 Hz pulse rate at the design gradient (65 MV/m) and pulse length (400 ns), and have reached breakdown rate levels below the limit for the linear collider. Moreover, the structures are robust in that the breakdown rates continue to decrease over time, and if the structures are briefly exposed to air, the rates recover to their low values within a few days. This paper pr...

  3. High Voltage Operation of Helical Pulseline Structures for Ion Acceleration

    CERN Document Server

    Waldron, William; Reginato, Lou

    2005-01-01

    The basic concept for the acceleration of heavy ions using a helical pulseline requires the launching of a high voltage traveling wave with a waveform determined by the beam transport physics in order to maintain stability and acceleration.* This waveform is applied to the front of the helix, creating over the region of the ion bunch a constant axial acceleration electric field that travels down the line in synchronism with the ions. Several methods of driving the helix have been considered. Presently, the best method of generating the waveform and also maintaining the high voltage integrity appears to be a transformer primary loosely coupled to the front of the helix, generating the desired waveform and achieving a voltage step-up from primary to secondary (the helix). This can reduce the drive voltage that must be brought into the helix enclosure through the feedthroughs by factors of 5 or more. The accelerating gradient is limited by the voltage holding of the vacuum insulator, and the material and helix g...

  4. A conceptual design of the RF system for the NSP high intensity proton accelerator at JAERI

    International Nuclear Information System (INIS)

    Chishiro, Etsuji; Kusano, Joichi; Mizumoto, Motoharu; Touchi, Yutaka; Kaneko, Hiroshi; Takado, Hiroshi; Sawada, Junichi

    1999-03-01

    JAERI has been proposing the Neutron Science Project which aims at exploring the fields of basic science and nuclear technology using a high power spallation neutron source. The neutron source will be driven by a high intensity linear accelerator with an energy of 1.5 GeV and an average beam current of 5.33 mA and beam power of 8 MW. The RF system for the accelerator consists of a high-energy accelerator part and a low energy accelerator part. The maximum RF power requirements at the high and low energy accelerator parts are 25 MW and 8.3 MW, respectively. In this report, we describe the conceptual design of the RF system. In the low energy accelerator part, we estimated the requirement for the high-power amplifier tube and made the basis design for RF components. In the high energy accelerator part, we studied the effect of tuning errors, Lorentz forces and microphonics in the superconducting cavity. We calculated the klystron efficiency and supply power in the arrangement of where one klystron distributes the RF power to four cavities. We also considered an IOT RF system. Finally, we describe the electrical capacity and quantity of cooling water in the RF system. (author)

  5. Accelerated and Rational Design of Improved CHO Cell Factories

    DEFF Research Database (Denmark)

    Grav, Lise Marie

    . This allows us to i) facilitate improved studies of gene functions, ii) remove cellular traits that are disadvantageous to protein production, iii) control and predict the level and stability of protein expression, and iv) design and engineer new cellular functions. Overall, the results of this thesis...

  6. The design of gridded pierce guns for accelerators

    International Nuclear Information System (INIS)

    True, R.

    1985-01-01

    It is vital to employ ultra-laminar beams in electron linacs to maximize charge transport to the target. This paper presents numerical and experimental design techniques which have led to significant improvements in gridded Pierce guns used in microwave tubes and electron linacs. The paper concludes with two gun/injector concepts which have demonstrated enhanced performance over standard triode Pierce guns

  7. Design Thinking Accelerated Leadership: Transforming Self, Transforming Community

    Science.gov (United States)

    Lake, Danielle; Ricco, Michael E.; Whipps, Judy

    2016-01-01

    Higher education institutions are continually seeking to recruit nontraditional adult students yet struggle at the same time to meet their needs effectively. The following case study offers strategies to address this situation by documenting the pedagogical design and initial outcomes of an interdisciplinary, nineteen-month leadership-themed…

  8. Post-accelerator LINAC design for the VECC RIB project

    Indian Academy of Sciences (India)

    The LINAC design work starts with the generation of the cell tables for the LINAC tanks, i.e., to find out the cell lengths, operating voltage, number of cells in the tanks etc. A program CELLGEN has been developed for this purpose. In addition to generating the cell parameters, it also produces the input file for the beam ...

  9. Study on the coaxial couplers for disk and washer loaded accelerating structures

    International Nuclear Information System (INIS)

    Dajkovskij, A.G.; Paramonov, V.V.; Portugalov, Yu.I.; Ryabov, A.D.; Ryabova, T.D.

    1983-01-01

    The paper describes the dispersion and energy properties of the coaxial coupler (CC), which is a promising component for an accelerating system, with the disk and washer (DAW) structure. Resonators, consisting of the DAW structure sections and CC are shown to persist the main advantage of DAW structure, i.e. high stability of the accelerating field distribution. Therewith RF power losses are small. The presence of nonsymetriric modes in the neighbourbood of the operating mode is noted

  10. Design concept of radiation control system for the high intensity proton accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori; Harada, Yasunori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics. (author)

  11. Design of Accelerated Reliability Test for CNC Motorized Spindle Based on Vibration Signal

    Directory of Open Access Journals (Sweden)

    Chen Chao

    2016-01-01

    Full Text Available Motorized spindle is the key functional component of CNC machining centers which is a mechatronics system with long life and high reliability. The reliability test cycle of motorized spindle is too long and infeasible. This paper proposes a new accelerated test for reliability evaluation of motorized spindle. By field reliability test, authors collect and calculate the load data including rotational speed, cutting force and torque. Load spectrum distribution law is analyzed. And authors design a test platform to apply the load spectrum. A new method to define the fuzzy acceleration factor based on the vibration signal is proposed. Then the whole test plan of accelerated reliability test is done.

  12. Accelerator driven systems for energy production and waste incineration: Physics, design and related nuclear data

    International Nuclear Information System (INIS)

    Herman, M.; Stanculescu, A.; Paver, N.

    2003-01-01

    This volume contains the notes of lectures given at the workshops 'Hybrid Nuclear Systems for Energy Production, Utilisation of Actinides and Transmutation of Long-lived Radioactive Waste' and 'Nuclear Data for Science and Technology: Accelerator Driven Waste Incineration', held at the Abdus Salam ICTP in September 2001. The subject of the first workshop was focused on the so-called Accelerator Driven Systems, and covered the most important physics and technological aspects of this innovative field. The second workshop was devoted to an exhaustive survey on the acquisition, evaluation, retrieval and validation of the nuclear data relevant to the design of Accelerator Driven Systems

  13. Scaling of induction-cell transverse impedance: effect on accelerator design

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Carl August [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-09

    The strength of the dangerous beam breakup (BBU) instability in linear induction accelerators (LIAs) is characterized by the transverse coupling impedance Z. This note addresses the dimensional scaling of Z, which is important when comparing new LIA designs to existing accelerators with known i BBU growth. Moreover, it is shown that the scaling of Z with the accelerating gap size relates BBU growth directly to high-voltage engineering considerations. It is proposed to firmly establish this scaling though a series of AMOS calculations.

  14. Three dimensional finite element methods: Their role in the design of DC accelerator systems

    Energy Technology Data Exchange (ETDEWEB)

    Podaru, Nicolae C.; Gottdang, A.; Mous, D. J. W. [High Voltage Engineering Europa B.V., P.O. Box 99, 3800 AB, Amersfoort (Netherlands)

    2013-04-19

    High Voltage Engineering has designed, built and tested a 2 MV dual irradiation system that will be applied for radiation damage studies and ion beam material modification. The system consists of two independent accelerators which support simultaneous proton and electron irradiation (energy range 100 keV - 2 MeV) of target sizes of up to 300 Multiplication-Sign 300 mm{sup 2}. Three dimensional finite element methods were used in the design of various parts of the system. The electrostatic solver was used to quantify essential parameters of the solid-state power supply generating the DC high voltage. The magnetostatic solver and ray tracing were used to optimize the electron/ion beam transport. Close agreement between design and measurements of the accelerator characteristics as well as beam performance indicate the usefulness of three dimensional finite element methods during accelerator system design.

  15. Design and applications of a pneumatic accelerator for high speed punching

    International Nuclear Information System (INIS)

    Yaldiz, Sueleyman; Saglam, Haci; Unsacar, Faruk; Isik, Hakan

    2007-01-01

    High speed forming is an important production method that requires specially designed HERF (high energy rate forming) machines. Most of the HERF machines are devices that consist of a system in which energy is stored and a differential piston mechanism is used to release the energy at high rate. In order to eliminate the usage of specially designed HERF machines and to obtain the high speed forming benefits, the accelerator which can be adapted easily onto conventional presses has been designed and manufactured in this study. The designed energy accelerator can be incorporated into mechanical press to convert the low speed operation into high-speed operation of a hammer. Expectations from this work are reduced distortion rates, increased surface quality and precise dimensions in metal forming operations. From the performance test, the accelerator is able to achieve high speed and energy which require for high speed blanking of thick sheet metals

  16. FPGA design and implementation of a matrix multiplier based accelerator for 3D EKF SLAM

    OpenAIRE

    Tortei, Daniel; Piat, Jonathan; Devy, Michel

    2014-01-01

    International audience; In hw/sw co-design FPGAs are being used in order to accelerate existing solutions so they meet real-time constraints. As they consume less power than a standard microprocessor and provide powerful parallel data processing capabilities, they remain a highly optimizable tool and object of research within an embedded system. In this paper we present an efficient architecture for matrix multiplication accelerator conceived as a systolic array co-processor to IBM's PPC440 p...

  17. Design considerations of transmission line superconductors for fast-cycling accelerator magnets

    International Nuclear Information System (INIS)

    Piekarz, H.; Fermilab

    2008-01-01

    Novel design options of HTS and LTS superconductor lines for fast-cycling accelerator magnets are presented. The cryogenic power losses in using these conductors in transmission line application to energize the accelerator magnet string are discussed. A test arrangement to measure power loss of the proposed superconductor lines operating up to 2 T/s ramp rate and 0.5 Hz repetition cycle is described

  18. Design considerations of translmission line superconductors for fast-cycling accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Piekarz, H.; /Fermilab

    2008-07-01

    Novel design options of HTS and LTS superconductor lines for fast-cycling accelerator magnets are presented. The cryogenic power losses in using these conductors in transmission line application to energize the accelerator magnet string are discussed. A test arrangement to measure power loss of the proposed superconductor lines operating up to 2 T/s ramp rate and 0.5 Hz repetition cycle is described.

  19. High power experimental studies of hybrid photonic band gap accelerator structures

    Directory of Open Access Journals (Sweden)

    JieXi Zhang

    2016-08-01

    Full Text Available This paper reports the first high power tests of hybrid photonic band gap (PBG accelerator structures. Three hybrid PBG (HPBG structures were designed, built and tested at 17.14 GHz. Each structure had a triangular lattice array with 60 inner sapphire rods and 24 outer copper rods sandwiched between copper disks. The dielectric PBG band gap map allows the unique feature of overmoded operation in a TM_{02} mode, with suppression of both lower order modes, such as the TM_{11} mode, as well as higher order modes. The use of sapphire rods, which have negligible dielectric loss, required inclusion of the dielectric birefringence in the design. The three structures were designed to sequentially reduce the peak surface electric field. Simulations showed relatively high surface fields at the triple point as well as in any gaps between components in the clamped assembly. The third structure used sapphire rods with small pin extensions at each end and obtained the highest gradient of 19  MV/m, corresponding to a surface electric field of 78  MV/m, with a breakdown probability of 5×10^{-1} per pulse per meter for a 100-ns input power pulse. Operation at a gradient above 20  MV/m led to runaway breakdowns with extensive light emission and eventual damage. For all three structures, multipactor light emission was observed at gradients well below the breakdown threshold. This research indicated that multipactor triggered at the triple point limited the operational gradient of the hybrid structure.

  20. Numerical analysis of terminal charge selector designs for electrostatic accelerators

    International Nuclear Information System (INIS)

    Ferrero, A.M.J.

    1986-01-01

    The performance of two terminal charge selector designs is analyzed by numerical integration of particle trajectories. It is shown that the attempt to offset the electrical quadrupole field by displacement of the two poles in the bending plane of each quadrupole results in large beam aberration and poor charge selection efficiency. A numerical analysis performed by offsetting the quadrupole field displacing the entire quadrupole off the beam axis yielded satisfactory charge resolution. (orig.)

  1. Accelerator production of tritium pollution prevention design assessment

    International Nuclear Information System (INIS)

    Reynolds, R.; Nowacki, P.; Sheetz, S.O.; Lanik, P.

    1997-01-01

    This Pollution Prevention Design Assessment (PPDA) provides data for cost-benefit analysis of the potential environmental impact of the APT, is an integral part of pollution prevention/waste minimization, and is required by DOE for any activity generating radioactive, hazardous, and mixed wastes. It will also better position the APT to meet future requirements, since it is anticipated that regulatory and other requirements will continue to become more restrictive and demanding

  2. Accelerator production of tritium pollution prevention design assessment

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, R.; Nowacki, P.; Sheetz, S.O. [Westinghouse Savannah River Co., Aiken, SC (United States); Lanik, P. [Burns and Roe Engineering Inc. (United States)

    1997-09-18

    This Pollution Prevention Design Assessment (PPDA) provides data for cost-benefit analysis of the potential environmental impact of the APT, is an integral part of pollution prevention/waste minimization, and is required by DOE for any activity generating radioactive, hazardous, and mixed wastes. It will also better position the APT to meet future requirements, since it is anticipated that regulatory and other requirements will continue to become more restrictive and demanding.

  3. Analysis of experimental activities relevant to the design, safety and licensing of the accelerator-driven system concept

    International Nuclear Information System (INIS)

    Burgazzi, Luciano

    2010-01-01

    This report presents the experimental activities, conducted so far, on the coupling of an accelerator, a spallation target and a sub-critical blanket and analyses the opportunity for their extrapolation to the concept of an eXperimental facility demonstrating the technical feasibility of Transmutation in an Accelerator-Driven System (XT-ADS), within the European Union funded project EUROTRANS (EUROpean Research Programme for the TRANSmutaion of High Level Nuclear Waste in an Accelerator-Driven System). The experiments conducted essentially on MEGAPIE (MEGAwatt Pilot Experiment) facilities are considered, to provide validated experimental inputs to assist the design of XT-ADS and to address the main safety issues for licensing purposes. The analysis of some aspects related to RACE (Reactor-Accelerator Coupling Experiments) experiments complete the study. The study is structured as follows: at first the main specificities of the XT-ADS are presented and the significant issues with reference to the main systems as accelerator, target and system as a whole are identified. Lastly the experiences are analysed in the light of the new experimental facility in terms mostly of safety and licensing significant aspects of singular subsystems and integral facility as a whole.

  4. Contribution to the design of superconducting Nb3Sn dipole windings for particle accelerator

    International Nuclear Information System (INIS)

    Felice, H.

    2006-10-01

    Improvement of particle accelerators relies on complex technologies such as the design and fabrication of superconducting magnets. A key parameter in magnet design is the mechanical pre-stress, applied at room temperature to insure compression of the coil during excitation. In dipole magnets, high field and high mechanical stresses in windings combined with the Nb 3 Sn stress sensitivity ask the question of the limit of the mechanical stress that the Nb 3 Sn can undergo without degradation. This limit estimated around 150 MPa is still discussed and has to be investigated. Whatever its value, preliminary studies show that conventional cosine theta design induces mechanical stresses (> 200 MPa) in large aperture (> 130 mm) and high field configurations, which underscore the need of alternative coil arrangements. The first part of this thesis gives an introduction to the issues and challenges encountered by the designers of superconducting ma nets. The second part is devoted to the study of large aperture (88, 130 and 160 mm) and high field (13 T) dipoles based on intersecting ellipses. After a theoretical study, a 2D magnetic design is detailed for each aperture and a mechanical study is developed for the 130 mm aperture dipole. In the last part, an experimental device dedicated to the study of the influence of the pre-stress on the training of sub-scale Nb 3 Sn dipole and to the investigation of the mechanical stress limit is presented. The design of this magnet is detailed and the result of the first test carried out with the structure is reported. (author)

  5. Symposium on the Occassion of 70th Birthday of Juwen Wang : High Gradient Accelerating Structure

    CERN Document Server

    2015-01-01

    This proceedings volume, for the symposium in honor of Junwen Wang's 70th anniversary, is dedicated to his many important achievements in the field of accelerator physics.It includes the discussions of recent advances and challenging problems in the field of high gradient accelerating structure development.

  6. Design of rf-cavities in the funnel of accelerators for transmutation technologies

    International Nuclear Information System (INIS)

    Krawczyk, F.L.; Bultman, N.K.; Chan, K.D.C.; Martineau, R.L.; Nath, S.; Young, L.M.

    1994-01-01

    Funnels are a key component of accelerator structures proposed for transmutation technologies. In addition to conventional accelerator elements, specialized rf-cavities are needed for these structures. Simulations were done to obtain their electromagnetic field distribution and to minimize the rf-induced heat loads. Using these results a structural and thermal analysis of these cavities was performed to insure their reliability at high average power and to determine their cooling requirements. For one cavity the thermal expansion data in return was used to estimate the thermal detuning

  7. First high power tests of clic prototype accelerating structures with hom waveguide damping

    CERN Document Server

    Döbert, S; Riddone, G; Wuensch, W; Zennaro, R; Higo, T; Matsumoto, S; Yokoyama, K; Adolphsen, C; Wang, F; Wang, J

    2010-01-01

    Prototype accelerating structures for the Compact Linear Collider (CLIC) are being developed and high-power tested in collaboration between SLAC, KEK and CERN. Several undamped, low group-velocity and strongly tapered prototypes (of the so-called T18 design) have been operated above 100 MV/m average gradients at a very low breakdown rates. Recently two new structures with the same iris apertures but now including higher order mode damping waveguides in each cell (TD18 design) have been tested at SLAC and KEK. The damped versions could be processed to similar gradients but an increased breakdown rate was observed. The damping waveguides lead to a magnetic field enhancement in the outer diameter of the cells which results in increased pulsed surface heating. The maximum pulsed temperature rise is 80 deg at the design gradient of 100 MV/m compared to only 20 deg for the undamped version. The high-power tests of the two TD18 structures are analyzed with special emphasis to understand if the higher breakdown rate ...

  8. Tests of a niobium split-ring superconducting heavy ion accelerating structure

    Energy Technology Data Exchange (ETDEWEB)

    Benaroya, R.; Bollinger, L.M.; Jaffey, A.H.; Khoe, T.K.; Olesen, M.C.; Scheibelhut, C.H.; Shepard, K.W.; Wesolowski, W.A.

    1976-01-01

    A niobium split-ring accelerating structure designed for use in the Argonne superconducting heavy-ion energy booster was successfully tested. The superconducting resonator has a resonant frequency of 97 MHz and an optimum particle velocity ..beta.. = 0.11. Ultimate performance is expected to be limited by peak surface fields, which in this structure are 4.7 E/sub a/ electric and 170 E/sub a/ (Gauss) magnetic, where E/sub a/ is the effective accelerating gradient in MV/m. The rf losses in two demountable superconducting joints severely limited performance in initial tests. Following independent measurements of the rf loss properties of several types of demountable joints, one demountable joint was eliminated and the other modified. Subsequently, the resonator could be operated continuously at E/sub a/ = 3.6 MV/m (corresponding to an energy gain of 1.3 MeV per charge) with 10W rf input power. Maximum field level was limited by electron loading. The mechanical stability of the resonator under operating conditions is excellent: vibration induced eigenfrequency noise is less than 120 Hz peak to peak, and the radiation pressure induced frequency shift is ..delta..f/f = 1.6 x 10/sup -6/ E/sub a//sup 2/.

  9. Tests of a niobium split-ring superconducting heavy ion accelerating structure

    International Nuclear Information System (INIS)

    Benaroya, R.; Bollinger, L.M.; Jaffey, A.H.; Khoe, T.K.; Olesen, M.C.; Scheibelhut, C.H.; Shepard, K.W.; Wesolowski, W.A.

    1976-01-01

    A niobium split-ring accelerating structure designed for use in the Argonne superconducting heavy-ion energy booster was successfully tested. The superconducting resonator has a resonant frequency of 97 MHz and an optimum particle velocity β = 0.11. Ultimate performance is expected to be limited by peak surface fields, which in this structure are 4.7 E/sub a/ electric and 170 E/sub a/ (Gauss) magnetic, where E/sub a/ is the effective accelerating gradient in MV/m. The rf losses in two demountable superconducting joints severely limited performance in initial tests. Following independent measurements of the rf loss properties of several types of demountable joints, one demountable joint was eliminated and the other modified. Subsequently, the resonator could be operated continuously at E/sub a/ = 3.6 MV/m (corresponding to an energy gain of 1.3 MeV per charge) with 10W rf input power. Maximum field level was limited by electron loading. The mechanical stability of the resonator under operating conditions is excellent: vibration induced eigenfrequency noise is less than 120 Hz peak to peak, and the radiation pressure induced frequency shift is Δf/f = 1.6 x 10 -6 E/sub a/ 2

  10. Accelerating convergence of molecular dynamics-based structural relaxation

    DEFF Research Database (Denmark)

    Christensen, Asbjørn

    2005-01-01

    the influence of spectral properties and dimensionality of the molecular system on the algorithm efficiency. We test two algorithms, the MinMax and Lanczos, for spectral estimation from an MD trajectory, and use this to derive a practical scheme of time step adaptation in MD relaxation algorithms to improve...... efficiency. We also discuss the implementation aspects. Secondly, we explore the final state refinement acceleration by a combination with the conjugate gradient technique, where the key ingredient is an implicit corrector step. Finally, we test the feasibility of passive Hessian matrix accumulation from...... an MD trajectory, as another route for final phase acceleration. Our suggestions may be implemented within most MD quench implementations with a few, straightforward lines of code, thus maintaining the appealing simplicity of the MD quench algorithms. In this paper, we also bridge the conceptual gap...

  11. Design of electron beam accelerator for microwave application

    Science.gov (United States)

    Prestwich, K. R.

    Relativistic electron beams are used for generating high power microwaves. These microwave sources require electron beam generators spanning significant ranges in voltage and impedance. The pulsed power technology used to generate these electron beams is presented. Electron beam generators that produce beams with pulse durations in the 10 ns to 100 ns regime consist of an energy storage section, pulse shaping section, and an electron beam diode. The energy storage section is either a Marx generator or capacitor bank-pulsed transformer. The pulse shaping is done with high-voltage transmission lines. The electron beam diode is usually a cold-cathode, space-charge-limited flow device. For longer pulses (approx 1 microsec) the energy storage and pulse shaping can be combined. Lumped-element pulsed-forming networks (PFN) can be designed to produce the desired pulse shape. The Marx generator becomes one of the elements of the PFN. Alternatively, a low voltage PFN followed by a highly coupled transformer can be used. Basic design principles for all of the above subsystems are discussed. Both PFLs and PFNs can also be operated as inductive storage systems with opening switches.

  12. Development of small C-band standing-wave accelerator structure

    International Nuclear Information System (INIS)

    Miura, S.; Takahashi, A.; Hisanaga, N.; Sekido, H.; Yoshizumi, A.

    2000-01-01

    We have newly developed a compact C-band (5712 MHz) standing-wave accelerator for the medical product/waste sterilization applications. The accelerator consists of an electron gun operating at 25 kV DC followed by a single-cell pre-buncher and 3-cell buncher section, and 11-cell of the side-coupled standing-wave accelerating structure. The total length including the electron gun is about 600 mm. The first high-power test was performed in March 2000, where the accelerator successively generated the electron beam of 9 MeV energy and 160 mA peak-current at 3.8 MW RF input power. Mitsubishi Heavy Industry starts to serve the sterilization systems using C-band accelerator reported here, and also supplies the accelerator components for the medical oncology applications. (author)

  13. GeauxDock: Accelerating Structure-Based Virtual Screening with Heterogeneous Computing.

    Directory of Open Access Journals (Sweden)

    Ye Fang

    Full Text Available Computational modeling of drug binding to proteins is an integral component of direct drug design. Particularly, structure-based virtual screening is often used to perform large-scale modeling of putative associations between small organic molecules and their pharmacologically relevant protein targets. Because of a large number of drug candidates to be evaluated, an accurate and fast docking engine is a critical element of virtual screening. Consequently, highly optimized docking codes are of paramount importance for the effectiveness of virtual screening methods. In this communication, we describe the implementation, tuning and performance characteristics of GeauxDock, a recently developed molecular docking program. GeauxDock is built upon the Monte Carlo algorithm and features a novel scoring function combining physics-based energy terms with statistical and knowledge-based potentials. Developed specifically for heterogeneous computing platforms, the current version of GeauxDock can be deployed on modern, multi-core Central Processing Units (CPUs as well as massively parallel accelerators, Intel Xeon Phi and NVIDIA Graphics Processing Unit (GPU. First, we carried out a thorough performance tuning of the high-level framework and the docking kernel to produce a fast serial code, which was then ported to shared-memory multi-core CPUs yielding a near-ideal scaling. Further, using Xeon Phi gives 1.9× performance improvement over a dual 10-core Xeon CPU, whereas the best GPU accelerator, GeForce GTX 980, achieves a speedup as high as 3.5×. On that account, GeauxDock can take advantage of modern heterogeneous architectures to considerably accelerate structure-based virtual screening applications. GeauxDock is open-sourced and publicly available at www.brylinski.org/geauxdock and https://figshare.com/articles/geauxdock_tar_gz/3205249.

  14. GeauxDock: Accelerating Structure-Based Virtual Screening with Heterogeneous Computing

    Science.gov (United States)

    Fang, Ye; Ding, Yun; Feinstein, Wei P.; Koppelman, David M.; Moreno, Juana; Jarrell, Mark; Ramanujam, J.; Brylinski, Michal

    2016-01-01

    Computational modeling of drug binding to proteins is an integral component of direct drug design. Particularly, structure-based virtual screening is often used to perform large-scale modeling of putative associations between small organic molecules and their pharmacologically relevant protein targets. Because of a large number of drug candidates to be evaluated, an accurate and fast docking engine is a critical element of virtual screening. Consequently, highly optimized docking codes are of paramount importance for the effectiveness of virtual screening methods. In this communication, we describe the implementation, tuning and performance characteristics of GeauxDock, a recently developed molecular docking program. GeauxDock is built upon the Monte Carlo algorithm and features a novel scoring function combining physics-based energy terms with statistical and knowledge-based potentials. Developed specifically for heterogeneous computing platforms, the current version of GeauxDock can be deployed on modern, multi-core Central Processing Units (CPUs) as well as massively parallel accelerators, Intel Xeon Phi and NVIDIA Graphics Processing Unit (GPU). First, we carried out a thorough performance tuning of the high-level framework and the docking kernel to produce a fast serial code, which was then ported to shared-memory multi-core CPUs yielding a near-ideal scaling. Further, using Xeon Phi gives 1.9× performance improvement over a dual 10-core Xeon CPU, whereas the best GPU accelerator, GeForce GTX 980, achieves a speedup as high as 3.5×. On that account, GeauxDock can take advantage of modern heterogeneous architectures to considerably accelerate structure-based virtual screening applications. GeauxDock is open-sourced and publicly available at www.brylinski.org/geauxdock and https://figshare.com/articles/geauxdock_tar_gz/3205249. PMID:27420300

  15. Reduced length design of 9.8 MHz RF accelerating cavity for the positron accumulator ring (PAR) of the Advanced Photon Source (APS)

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Y.W.; Bridges, J.F.; Kustom, R.L.

    1993-07-01

    A 9.8-MHz RF accelerating cavity is developed for the first harmonic system in the APS PAR and an aluminum unit is tested. The design goal si 40 kV at the accelerating gap, Q-factor of {approximately} 7,000 for the accelerating mode, 1.2-m diameter, 1.6-m length with good mechanical strength and stability. The design employs no dielectric or ferrite loading for tuning. The cavity is a plunger-loaded reentrant coaxial structure; the end of the inner conductor facing the wall has a piston-shaped loading structure which consists of a circular disk and a cylinder. The RF characteristic of the cavity was investigated using the URMEL-T and MAFIA programs. Compared with a coaxial structure with lumped element capacitive loading, this design gives improved RF characteristics.

  16. Design and development of power supplies at VECC for accelerators

    International Nuclear Information System (INIS)

    Thakur, S.K.

    2013-01-01

    Several power supplies have been designed and developed in-house incorporating various topologies to match the load requirements. Most of the power supplies have been being utilised in K-130 and K-500 cyclotrons operation successfully from last several years. Amongst other types, Switching Mode PS (SMPS), Phase Controlled Rectifier (PCR), Linear mode power supply are mostly in use, irrespective of their own merits and demerits. Switching mode power supply (SMPS) is most common topology for various applications ranging from high current to high voltage applications. Due to low stored energy and faster response, the SMPS incorporating Pulse Switch Modulation (PSM) configuration is most suitable for high voltage DC power supply at larger power compared to its counterparts, makes possible to operate the power system without crowbar. For an IOT cathode power supply, a 200kW at - 40kV High voltage power supply is under development incorporating SMPS and PSM technique. Earlier, High Voltage power supply was made by using Tetrode Tube in linear mode for RF amplifier for K-130 Cyclotron. Later, in K-500 Cyclotron, a High Voltage power supply was developed incorporating PCR topology rated at 20kV, 20 Amp for Anodes for 3 nos. of RF amplifiers. These HV power supply is equipped with ultra-fast acting Crowbar Protection System developed in VECC which is for the protection of costly RF Tubes against the internal arc. Design and development of SMPS based Bipolar Power Supply with 4-Quadrant operation rated at ± 27 V, ± 300 Amp with current stability around 100 ppm for Super-conducting Magnets along with quench protection and energy dumping scheme. (author)

  17. Accelerated DFT-Based Design of Materials for Ammonia Storage

    DEFF Research Database (Denmark)

    Jensen, Peter Bjerre; Bialy, Agata; Blanchard, Didier

    2015-01-01

    . Therefore, there is a need for new materials, releasing the ammonia in a narrow temperature interval. To search for new mixed metal halide chlorides, we use DFT calculations guided by a genetic algorithm (GA) to expedite the search, as the defined search space allowing up to three different metals contains...... more than 100,000 different structures. Here, we search for materials releasing the ammonia between 0 and 100 °C, a temperature range suitable for system integration with low-temperature polymer electrolyte membrane fuel cells (PEMFC). The efficiency of the implemented algorithm is verified by three...... trial runs capable of finding the same optimal mixtures starting from different random populations, testing

  18. The mechatronic design of a fast wire scanner in IHEP U-70 accelerator

    International Nuclear Information System (INIS)

    Baranov, V.T.; Makhov, S.S.; Savin, D.A.; Terekhov, V.I.

    2016-01-01

    This paper presents the mechatronic design of a fast wire scanner based on a servomotor. The design of the wire scanner is motivated by the need to measure the transverse profile of the high power proton and carbon beams at the IHEP U-70 accelerator. This paper formulates the requirements to the fast wire scanner system for the high intensity proton beam at the U-70 accelerator. The results on the design of electro-mechanical device for the wire scanner with a wire traveling speed 10–20 m/s are presented. The solution consists in a brushless servomotor and standard motor control electronics. High radiation levels in the accelerator enclosure dictate the use of a resolver as the position feedback element.

  19. Design of a non-scaling FFAG accelerator for proton therapy

    International Nuclear Information System (INIS)

    Trbojevic, D.; Ruggiero, A.G.; Keil, E.; Neskovic, N.; Belgrade, Vinca; Sessler, A.

    2005-01-01

    In recent years there has been a revival of interest in Fixed Field Alternating Gradient (FFAG) accelerators. In Japan a number have been built, or are under construction. A new non-scaling approach to the FFAG reduces the required orbit offsets during acceleration and the size of the required aperture, while maintaining the advantage of the low cost magnets associated with fixed fields. An advantage of the non-scaling FFAG accelerator, with respect to synchrotrons, is the fixed field and hence the possibility of high current and high repetition rate for spot scanning. There are possible advantages of the nonscaling design with respect to fixed-field cyclotrons. The non-scaling FFAG allows strong focusing and hence smaller aperture requirements compared to scaling designs, thus leading to very low losses and better control over the beam. We present, here, a non-scaling FFAG designed to be used for proton therapy

  20. A study on the development plan and preliminary design of proton accelerator for nuclear application

    International Nuclear Information System (INIS)

    Eom, Tae Yoon; Choi, B. H.; Park, C. K.; Chung, K. S. and others

    1997-11-01

    A study on the development plan and preliminary design for the realisation of high current proton accelerator to be used as an essential component for the R and D of accelerator-driven system (ADS) for energy production and transmutation of long-lived radionuclides. Various fields of application of the accelerator such as basic nuclear physics, material science, biology, high energy physics, medicine, etc. were also investigated. From the preliminary design study, 1 GeV (20 mA) - Linac is required for the purposed of transmutation and energy production. Specification of injector, RFQ, CCTL and SL was also suggested. For the case study, a duoplasmatron ion source was designed by KAERI and fabricated by a domestic manufacturer, and the performance was also tested. (author). 71 refs., 61 tabs., 131 figs

  1. The mechatronic design of a fast wire scanner in IHEP U-70 accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Baranov, V.T. [Institute for High Energy Physics in National Research Centre “Kurchatov Institute”, Protvino 142281 (Russian Federation); Makhov, S.S. [Microprivod Ltd., Moscow 111123 (Russian Federation); Savin, D.A.; Terekhov, V.I. [Institute for High Energy Physics in National Research Centre “Kurchatov Institute”, Protvino 142281 (Russian Federation)

    2016-10-11

    This paper presents the mechatronic design of a fast wire scanner based on a servomotor. The design of the wire scanner is motivated by the need to measure the transverse profile of the high power proton and carbon beams at the IHEP U-70 accelerator. This paper formulates the requirements to the fast wire scanner system for the high intensity proton beam at the U-70 accelerator. The results on the design of electro-mechanical device for the wire scanner with a wire traveling speed 10–20 m/s are presented. The solution consists in a brushless servomotor and standard motor control electronics. High radiation levels in the accelerator enclosure dictate the use of a resolver as the position feedback element.

  2. On the application of design of experiments to accelerated life testing

    International Nuclear Information System (INIS)

    Hakim-Mashhadi, M.

    1992-01-01

    Today, there is an increasing demand for improved quality and reliability due to increasing system complexity and increasing demands from customer. Continuous improvement of quality is not only a means of competition but also a matter of staying in the market. Accelerated life testing and statistical design of experiments are two needed methods for improvement of quality. The combined use of them is very advantageous and increases the test efficiency. Accelerated life testing is a quick way to provide information on the life distribution of materials and products. By subjecting the test unit to conditions more severe than those at normal usage, the test time can be highly reduced. Estimates of life at normal stress levels are obtained by extrapolating the available information through a reasonable acceleration model. Accelerated life testing has mostly been used to measure reliability but it is high time to use it for improvement of quality. Design of experiments serves to find out the effect of design parameters and other interesting factors on performance measure and its variability. The obtained information is essential for a continuous improvement of quality. As an illustration, two sets of experiment are designed and performed at highly increased stress levels. The results are analysed and discussed and a time saving alternative is proposed. The combination of experimental design and accelerated life testing is discussed and illustrated. The combined use of these methods can be argued for in two different cases. One is for an exploratory improvement investigation and the other is for verification of reliability. In either case, the combined use is advantageous and improves the testing efficiency. Some general conclusions are drawn to be used for planning and performance of statistically designed accelerated life testing experiments. (70 refs.) (au)

  3. Design of a high DC voltage generator and D-T fuser based on particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Wagner L.; Campos, Tarcisio P.R., E-mail: wagnerleite@ufmg.b, E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (DEN/ UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2011-07-01

    This paper approaches a design and simulation of a high voltage Cockcroft Walton multiplier and a compact size deuteron accelerator addressed in neutron generation by d-t fusion. We proposed a circuit arrangement, which was led to simulations. The particle accelerator was computer-generated providing particle transport and electric potential analysis. As results, the simulated voltage multiplier achieved 119 kV, and the accelerator presented a deuteron beam current up to 15 mA, achieving energies in order to 100 keV. In conclusion, the simulation motivates experimental essays in order to investigate the viability of a deuteron accelerator powered by a Cockcroft-Walton source. Such d-t fusor shall produce an interesting ion beam profile, reaching energy values near the d-t fusion cross section peak. (author)

  4. Conceptual design study for the proposed ISOL post-accelerator at TRIUMF

    International Nuclear Information System (INIS)

    McMichael, G.E.; Chidley, B.G.; Hutcheon, R.M.

    1985-11-01

    The proposed TRIUMF ISOL facility will include the capability to accelerate the extracted radioactive heavy ions for use in a wide range of astrophysics experiments. This report presents a conceptual design for such a post-accelerator, with parameters specific to the TRIUMF facility. It features a 4-rod 23 MHz RFQ linac, able to accelerate singly charged ions with masses to 60 amu, from 1 to 60 keV/amu, and a 23 MHz DTL for singly charged mass 20 ions (or triply charged ions of mass 60 or less) to complete the acceleration to any desired value in the range 0.265 to 1 MeV/amu. Two single gap bucket rotator cavities reduce the energy spread to 1 part in 10 3 over the whole energy range

  5. Experimental study of liquid-metal target designs of accelerating-controlled systems

    International Nuclear Information System (INIS)

    Iarmonov, Mikhail; Makhov, Kirill; Novozhilova, Olga; Meluzov, A.G.; Beznosov, A.V.

    2011-01-01

    Models of a liquid-metal target of an accelerator-controlled system have been experimentally studied at the Nizhny Novgorod State Technical University to develop an optimal design of the flow part of the target. The main explored variants of liquid-metal targets are: Design with a diaphragm (firm-and-impervious plug) mounted on the pipe tap of particle transport from the accelerator cavity to the working cavity of the liquid-metal target. Design without a diaphragm on the pipe tab of particle transport from the accelerator. The study was carried out in a high-temperature liquid-metal test bench under the conditions close to full-scale ones: the temperature of the eutectic lead-bismuth alloy was 260degC - 400degC, the coolant mass flow was 5-80 t/h, and the rarefaction in the gas cavity was 10 5 Pa, the coefficient of geometric similarity equal to 1. The experimental studies of hydrodynamic characteristics of flow parts in the designs of targets under full-scale conditions indicated high efficiency of a target in triggering, operating, and deactivating modes. Research and technology instructions for designs of the flow part of the liquid-metal target, the target design as a whole, and the target circuit of accelerator-controlled systems were formulated as a result of the studies. (author)

  6. Design and fabrication of topologically optimized structures;

    DEFF Research Database (Denmark)

    Feringa, Jelle; Søndergaard, Asbjørn

    2012-01-01

    sets the resolution of the TO. While the approach of the application of TO as a constitutive design tool centers on structural aspects in the design phase (Xie 2010), the outcome of this process are structures that cannot be realized within a conventional budget. As such the ensuing design is optimal...... & Dombernowsky 2011). A strength of the method is that it allows to come up with structural designs that lie beyond the grasp of traditional means of design. A design space is a discretized volume, delimiting where the optimization will take place. The number of cells used to discretize the design space thus...

  7. A shielding design for an accelerator-based neutron source for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, A.E.; Blue, T.E. E-mail: blue.1@osu.edu; Woollard, J.E

    2004-11-01

    Research in boron neutron capture therapy (BNCT) at The Ohio State University Nuclear Engineering Department has been primarily focused on delivering a high quality neutron field for use in BNCT using an accelerator-based neutron source (ABNS). An ABNS for BNCT is composed of a proton accelerator, a high-energy beam transport system, a {sup 7}Li target, a target heat removal system (HRS), a moderator assembly, and a treatment room. The intent of this paper is to demonstrate the advantages of a shielded moderator assembly design, in terms of material requirements necessary to adequately protect radiation personnel located outside a treatment room for BNCT, over an unshielded moderator assembly design.

  8. Design of third-order uniform acceleration and deceleration trajectory based on Simulink StateFlow

    Science.gov (United States)

    Yang, Xudong; Wang, Song

    2017-12-01

    In order to improve the movement accuracy of the robot, let the movement of the robot trajectory smoother, we design a third-order uniform acceleration / deceleration trajectory based on the Jerk value. Through the establishment of the mathematical model of the trajectory, combined with the logic control algorithm, constituted the core of the trajectory control. Finally, the StateFlow toolbox in Simulink as the carrier. Using the state module in StateFlow combined with the logic control conversion module, the third-order uniform acceleration and deceleration trajectory design is realized.

  9. Design of a high brightness ion source for the Basic Technology Accelerator (BTA)

    International Nuclear Information System (INIS)

    Okumura, Yoshikazu; Watanabe, Kazuhiro

    1992-03-01

    An ion source has been designed and fabricated for a 10 MeV, 10 mA, CW proton accelerator called Basic Technology Accelerator (BTA). The ion source consists of a multicusp plasma generator and a two-stage extractor, and is expected to produce a 100 keV, 120 mA H + ion beam with a normalized emittance of as low as 0.5 πmm.mrad. Guiding principles of the design are presented together with calculations on magnetic configuration, proton yield, plasma production, beam optics, and gas efficiency of the ion source. (author)

  10. Calculation of wakefields in a 17 GHz beam-driven photonic band-gap accelerator structure

    Directory of Open Access Journals (Sweden)

    Min Hu

    2013-02-01

    Full Text Available We present the theoretical analysis and computer simulation of the wakefields in a 17 GHz photonic band-gap (PBG structure for accelerator applications. Using the commercial code CST Particle Studio, the fundamental accelerating mode and dipole modes are excited by passing an 18 MeV electron beam through a seven-cell traveling-wave PBG structure. The characteristics of the longitudinal and transverse wakefields, wake potential spectrum, dipole mode distribution, and their quality factors are calculated and analyzed theoretically. Unlike in conventional disk-loaded waveguide (DLW structures, three dipole modes (TM_{11}-like, TM_{12}-like, and TM_{13}-like are excited in the PBG structure with comparable initial amplitudes. These modes are separated by less than 4 GHz in frequency and are damped quickly due to low radiative Q factors. Simulations verify that a PBG structure provides wakefield damping relative to a DLW structure. Simulations were done with both single-bunch excitation to determine the frequency spectrum of the wakefields and multibunch excitation to compare to wakefield measurements taken at MIT using a 17 GHz bunch train. These simulation results will guide the design of next-generation high-gradient accelerator PBG structures.

  11. Problems of structural mechanics in nuclear design

    International Nuclear Information System (INIS)

    Patwardhan, V.M.; Kakodkar, Anil

    1975-01-01

    A very careful and detailed stress analysis of nuclear presure vessels and components is essential for ensuring the safety and integrity of nuclear power plants. The nuclear designer, therefore, relies heavily on structural mechanics for application of the most advanced stress analysis techniques to practical design problems. The paper reviews the inter-relation between structural mechanics and nuclear design and discusses a few of the specific structural mechanics problems faced by the nuclear designers in the Department of Atomic Energy, India. (author)

  12. Accelerating convergence of molecular dynamics-based structural relaxation

    DEFF Research Database (Denmark)

    Christensen, Asbjørn

    2005-01-01

    We describe strategies to accelerate the terminal stage of molecular dynamics (MD)based relaxation algorithms, where a large fraction of the computational resources are used. First, we analyze the qualitative and quantitative behavior of the QuickMin family of MD relaxation algorithms and explore...... the influence of spectral properties and dimensionality of the molecular system on the algorithm efficiency. We test two algorithms, the MinMax and Lanczos, for spectral estimation from an MD trajectory, and use this to derive a practical scheme of time step adaptation in MD relaxation algorithms to improve...

  13. Theory of factors limiting high gradient operation of warm accelerating structures

    Energy Technology Data Exchange (ETDEWEB)

    Nusinovich, Gregory S. [Univ. of Maryland, College Park, MD (United States)

    2014-07-22

    This report consists of two parts. In the first part we describe a study of the heating of microprotrusions on surfaces of accelerating structures. This ;process is believed to lead to breakdown in these structures. Our study revealed that for current accelerator parameters melting should not occur due to space charge limitations of the current emitted by a protrusion. The second part describes a novel concept to develop THz range sources based on harmonic cyclotron masers for driving future colliders. This work was stimulated by a recent request of SLAC to develop high power, high-efficiency sources of sub-THz radiation for future high-gradient accelerators.

  14. Choke-Mode Damped Structure Design for the CLIC Main Linac

    CERN Document Server

    Zha, Hao; Tang, Chuanxiang; Huang, Wenhui; Shi, Jiaru; Grudiev, Alexej; Wuensch, Walter

    2012-01-01

    Choke-mode damped structures are being studied as an alternative design for the accelerating structures of main linacs of the compact linear collider (CLIC). Choke-mode structures have the potential for much lower pulsed temperature rise, and lower cost of manufacture and fabrication. A new kind of choke-mode structure was proposed and simulated by Gdfidl. This structures has comparable wakefield damping effect as the baseline design of CLIC main linacs.

  15. High power breakdown testing of a photonic band-gap accelerator structure with elliptical rods

    Directory of Open Access Journals (Sweden)

    Brian J. Munroe

    2013-01-01

    Full Text Available An improved single-cell photonic band-gap (PBG structure with an inner row of elliptical rods (PBG-E was tested with high power at a 60 Hz repetition rate at X-band (11.424 GHz, achieving a gradient of 128  MV/m at a breakdown probability of 3.6×10^{-3} per pulse per meter at a pulse length of 150 ns. The tested standing-wave structure was a single high-gradient cell with an inner row of elliptical rods and an outer row of round rods; the elliptical rods reduce the peak surface magnetic field by 20% and reduce the temperature rise of the rods during the pulse by several tens of degrees, while maintaining good damping and suppression of high order modes. When compared with a single-cell standing-wave undamped disk-loaded waveguide structure with the same iris geometry under test at the same conditions, the PBG-E structure yielded the same breakdown rate within measurement error. The PBG-E structure showed a greatly reduced breakdown rate compared with earlier tests of a PBG structure with round rods, presumably due to the reduced magnetic fields at the elliptical rods vs the fields at the round rods, as well as use of an improved testing methodology. A post-testing autopsy of the PBG-E structure showed some damage on the surfaces exposed to the highest surface magnetic and electric fields. Despite these changes in surface appearance, no significant change in the breakdown rate was observed in testing. These results demonstrate that PBG structures, when designed with reduced surface magnetic fields and operated to avoid extremely high pulsed heating, can operate at breakdown probabilities comparable to undamped disk-loaded waveguide structures and are thus viable for high-gradient accelerator applications.

  16. Studies on the S-band bunching system with the Hybrid Bunching-accelerating Structure

    Science.gov (United States)

    Pei, Shi-Lun; Gao, Bin

    2018-04-01

    Generally, a standard bunching system is composed of a standing-wave (SW) pre-buncher (PB), a traveling-wave (TW) buncher (B) and a standard accelerating structure. In the industrial area, the bunching system is usually simplified by eliminating the PB and integrating the B and the standard accelerating structure together to form a β-varied accelerating structure. The beam capturing efficiency for this kind of simplified system is often worse than that for the standard one. The hybrid buncher (HB) has been proved to be a successful attempt to reduce the cost but preserve the beam quality as much as possible. Here we propose to exclusively simplify the standard bunching system by integrating the PB, the B and the standard accelerating structure together to form a Hybrid Bunching-accelerating Structure (HBaS). Compared to the standard bunching system, the one based on the HBaS is more compact, and the cost is lowered to the largest extent. With almost the same beam transportation efficiency (∼70%) from the electron gun to the linac exit, the peak-to-peak (p-to-p) beam energy spread and the 1 σ emittance of the linac with the HBaS are ∼20% and ∼60% bigger than those of the linac based on the split PB/B/standard accelerating structure system. Nonetheless, the proposed HBaS can be widely applied in the industrial linacs to greatly increase the beam capturing efficiency without fairly increasing the construction cost.

  17. Experimental study of DC vacuum breakdown and application to high-gradient accelerating structures for CLIC

    CERN Document Server

    Shipman, Nicholas; Jones, Roger

    2016-01-01

    The compact linear collider (CLIC) is a leading candidate for the next generation high energy linear collider. As any breakdown would result in a partial or full loss of luminosity for the pulse in which it occurs, obtaining a low breakdown rate in CLIC accelerating structures is a critical requirement for the successful operation of the proposed collider. This thesis presents investigations into the breakdown phenomenon primarily in the low breakdown rate regime of interest to CLIC, performed using the CERN DC spark systems between 2011 and 2014. The design, construction and commissioning of several new pieces of hardware, as well as the development of improved techniques to measuring the inter-electrode gap distance are detailed. These hardware improvements were fundamental in enabling the exciting new experiments mentioned below, which in turn have provided significant additional insight into the phenomenon of breakdown. Experiments were performed to measure fundamental parameters of individual breakdowns...

  18. Study of Higher Order Modes in Superconducting Accelerating Structures for Linac Applications

    CERN Document Server

    Schuh, Marcel; Welsch, C P

    2011-01-01

    Higher Order Modes (HOMs) can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor and complex pulse structure. Therefore, the full HOM spectrum has to be analysed in detail to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam dynamics simulation code, Simulation of higher order Mode Dynamics (SMD), focusing on beam-HOM interaction, has been developed in the frame of this project. SMD allows to analyse the beam behaviour under the presence of HOMs, taking into account many important effects, such as for example the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. SMD is used to investigate in detail into the effects of HOMs in the Superconducting Proton Linac (SPL) at CERN and in particular their potential to drive beam instabili- ties in the longitudinal and transverse direction. Based...

  19. An improved phase-control system for superconducting low-velocity accelerating structures

    International Nuclear Information System (INIS)

    Bogaty, J.M.; Clifft, B.E.; Shepard, K.W.; Zinkann, G.P.

    1989-01-01

    Microphonic fluctuations in the rf eigenfrequency of superconducting (SC) slow-wave structures must be compensated by a fast-tuning system in order to control the rf phase. The tuning system must handle a reactive power proportional to the product of the tuning range and the rf energy content of the resonant cavity. The accelerating field level of many of the SC cavities forming the ATLAS linac has been limited by the rf power capacity of the presently used PIN-diode based fast-tuner. A new system has been developed, utilizing PIN diodes operating immersed in liquid nitrogen, with the diodes controlled by a high-voltage VMOS FET driver. The system has operated at reactive power levels above 20 KVA, a factor of four increase over an earlier design. 7 refs., 2 figs

  20. An improved phase-control system for superconducting low-velocity accelerating structures

    Energy Technology Data Exchange (ETDEWEB)

    Bogaty, J.M.; Clifft, B.E.; Shepard, K.W.; Zinkann, G.P.

    1989-01-01

    Microphonic fluctuations in the rf eigenfrequency of superconducting (SC) slow-wave structures must be compensated by a fast-tuning system in order to control the rf phase. The tuning system must handle a reactive power proportional to the product of the tuning range and the rf energy content of the resonant cavity. The accelerating field level of many of the SC cavities forming the ATLAS linac has been limited by the rf power capacity of the presently used PIN-diode based fast-tuner. A new system has been developed, utilizing PIN diodes operating immersed in liquid nitrogen, with the diodes controlled by a high-voltage VMOS FET driver. The system has operated at reactive power levels above 20 KVA, a factor of four increase over an earlier design. 7 refs., 2 figs.

  1. An improved phase-controlled system for superconducting low-velocity accelerating structures

    International Nuclear Information System (INIS)

    Bogaty, J.M.; Clifft, B.E.; Shepard, K.W.; Zinkann, G.P.

    1989-01-01

    Microphonic fluctuations in the RF eigenfrequency of supeconducting (SC) slow-wave structures must be compensated by a fast-tuning system in order to control the RF phase. The tuning system must handle a reactive power proportional to the product of the tuning range and the RF energy content of the resonant cavity. The accelerating field level of many of the SC cavities forming the ATLAS linac has been limited by the RF power capacity of the presently used PIN-diode based fast-tuner. A new system has been developed, utilizing PIN diodes operating immersed in liquid nitrogen, with the diodes controlled by a high-voltage VMOS FET driver. The system has operated at reactive power levels above 20 KVA, a factor of four increase over an earlier design. 7 refs., 2 figs

  2. StructuralComponents : A software system for conceptual structural design

    NARCIS (Netherlands)

    Van de Weerd, B.; Rolvink, A.; Coenders, J.L.

    2012-01-01

    Conceptual design is the starting point of the design process. The conceptual design stage comprises the formation of several ideas or design concepts to meet the imposed constraints. StructuralComponents is a software application that attempts to provide the designing engineer with a suitable set

  3. Engineering Design of KSTAR tokamak main structure

    International Nuclear Information System (INIS)

    Im, K.H.; Cho, S.; Her, N.I.

    2001-01-01

    The main components of the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak including vacuum vessel, plasma facing components, cryostat, thermal shield and magnet supporting structure are in the final stage of engineering design. Hundai Heavy Industries (HHI) has been involved in the engineering design of these components. The current configuration and the final engineering design results for the KSTAR main structure are presented. (author)

  4. Reliability based Design of Coastal Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.

    2003-01-01

    Conventional design practice for coastal structures is deterministic in nature and is based on the concept of a design load which should not exceed the resistance (carrying capacity) of the structure. The design load is usually defined on a probabilistic basis as a characteristic value of the loa...

  5. Introduction to Microwave Linear [Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Whittum, David H

    1999-01-04

    The elements of microwave linear accelerators are introduced starting with the principles of acceleration and accelerating structures. Considerations for microwave structure modeling and design are developed from an elementary point of view. Basic elements of microwave electronics are described for application to the accelerator circuit and instrumentation. Concepts of beam physics are explored together with examples of common beamline instruments. Charged particle optics and lattice diagnostics are introduced. Considerations for fixed-target and colliding-beam experimentation are summarized.

  6. The calculation technique for accelerating channel of the structure with the space-uniform RFQ focusing

    CERN Document Server

    Tishkin, S S; Kobets, A F; Sanin, V M

    2001-01-01

    Calculations were carried out for the initial part of the heavy ion accelerator with the large mass-to-charge ratio (a/q=46). The process of calculation is divided in four stages.At the first stage the average aperture radius and the field strength are determined according to the initial data. At the second stage the optimization of the accelerating tract is performed. To the purpose, the structure is divided in 6 sections: a funnel (a cone), a bunch former, a prebuncher,an adiabatic buncher, a booster, an accelerating section. At the third stage the obtained data are recalculated in the values of the modulation depth and lengths of the accelerating periods with taking into account the real fields. At the fourth stage the beam parameters at the accelerator output are determined for the tract built with taking into account the space charge forces and the input beam parameters.

  7. Design and beam test of the Beijing 35 MeV proton linear accelerator

    International Nuclear Information System (INIS)

    Zhou, Qingyi; Wang, Shuhong; Luo, Zihua

    1988-01-01

    In this paper, the Beijing 35 MeV proton linac is described from several aspects including the general project background, general facility description, design feature and techniques with emphasis on the 10 MeV to 35 MeV energy extension. Field distribution adjustments and accelerator tune up are also presented in detail. (author)

  8. Physics design of a CW high-power proton Linac for accelerator ...

    Indian Academy of Sciences (India)

    [7] T P Wangler, Principles of RF linear accelerators (John Wiley & Sons Inc., 1998). [8] K Shepard et al, Proceedings of the XIX International Linac Conference (Chicago, Illinois) p. 956. [9] C Pagani et al, Design criteria for elliptical cavities, SRF, 2001. [10] P Singh, S V L S Rao, Rajni Pande, T Basak, Shweta Roy, M Aslam, ...

  9. High power testing oa ANL X-band dielectric-loaded accelerating structures

    International Nuclear Information System (INIS)

    Power, J. G.; Gai, W.; Jing, C.; Konecny, R.; Gold, S. H.; Kinkead, A. K.

    2002-01-01

    In the second phase of a program to develop a compact accelerator based on a dielectric-loaded accelerating structure, we have conducted high power tests on a traveling-wave and a standing-wave prototype. Indications are that the traveling-wave structure achieved an accelerating gradient of 3-5 MV/m before the input coupling window failed, while the standing wave structure was poorly matched at high power due to contamination of copper residue on its coupling window. To solve both of these problems, a new method for coupling RF into the structures has been developed. The new couplers and the rest of the modular structure are currently under construction and will be tested at the Naval Research Laboratory shortly

  10. Comparative design of structures concepts and methodologies

    CERN Document Server

    Lin, Shaopei

    2016-01-01

    This book presents comparative design as an approach to the conceptual design of structures. Primarily focusing on reasonable structural performance, sustainable development and architectural aesthetics, it features detailed studies of structural performance through the composition and de-composition of these elements for a variety of structures, such as high-rise buildings, long-span crossings and spatial structures. The latter part of the book addresses the theoretical basis and practical implementation of knowledge engineering in structural design, and a case-based fuzzy reasoning method is introduced to illustrate the concept and method of intelligent design. The book is intended for civil engineers, structural designers and architects, as well as senior undergraduate and graduate students in civil engineering and architecture. Shaopei Lin and Zhen Huang are both Professors at the Department of Civil Engineering, Shanghai Jiao Tong University, China.

  11. Elementary and advanced Lie algebraic methods with applications to accelerator design, electron microscopes, and light optics

    International Nuclear Information System (INIS)

    Dragt, A.J.

    1987-01-01

    A review is given of elementary Lie algebraic methods for treating Hamiltonian systems. This review is followed by a brief exposition of advanced Lie algebraic methods including resonance bases and conjugacy theorems. Finally, applications are made to the design of third-order achromats for use in accelerators, to the design of subangstroem resolution electron microscopes, and to the classification and study of high order aberrations in light optics. (orig.)

  12. Earthquake resistant design of structures

    International Nuclear Information System (INIS)

    Choi, Chang Geun; Kim, Gyu Seok; Lee, Dong Geun

    1990-02-01

    This book tells of occurrence of earthquake and damage analysis of earthquake, equivalent static analysis method, application of equivalent static analysis method, dynamic analysis method like time history analysis by mode superposition method and direct integration method, design spectrum analysis considering an earthquake-resistant design in Korea. Such as analysis model and vibration mode, calculation of base shear, calculation of story seismic load and combine of analysis results.

  13. Micellar confinement disrupts collective structure and accelerates collective dynamics of encapsulated water.

    Science.gov (United States)

    Honegger, Philipp; Schmollngruber, Michael; Steinhauser, Othmar

    2018-04-12

    This computational study deals with the collective structure and dynamics as well as their interaction seen from a dielectric viewpoint in zwitterionic reverse micelles for which a force field was designed de novo. For this end, a dualistic strategy is followed: the raw data are generated by extensive microscopic molecular dynamics (MD) simulations while the subsequent analysis has a focus on mesoscopic dielectric properties. The unusually low dielectric signals as well as the remarkable acceleration of collective dynamics is elucidated in great detail. This structural and dynamic behaviour is caused essentially by non-specific micellar boundary conditions. We found that in these ion lacking reverse micelles the water core and the water sheath compensate each other dielectrically which can be understood as a LeChatelier phenomenon facilitating the transition from highly polar encapsulated water to the non-polar low dielectric medium octane. In addition, specific chemical effects are brought about by the perturbing influence of the surfactants. This comprehensive analysis aids both in understanding and designing the dipolar properties of liquid polar spherical colloids dispersed in a hydrophobic medium.

  14. Evaluation of deuteron-induced activation for IFMIF accelerator structural materials

    International Nuclear Information System (INIS)

    Nakao, Makoto; Ochiai, Kentaro; Kubota, Naoyoshi; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo; Hori, Jun-ichi; Ishioka, Noriko S.; Sudo, Hiroyuki

    2006-11-01

    The International Fusion Materials Irradiation Facility (IFMIF) is a neutron source facility designed to produce an intense neutron field for irradiation test of fusion reactor candidate materials. In the design of IFMIF, long-term operation with total facility availability of at least 70% is required. However, activation of structural materials by deuteron beam limits maintenance, which causes lower facility availability. Thus it is essential to prepare deuteron-induced activation cross section database and to select low activation materials based on it. In this work, we measured deuteron-induced activation cross sections of aluminum, vanadium, chromium, manganese, iron, nickel, copper, tantalum, tungsten and gold. The measured cross sections were compared with other experimental data and calculations. Deuteron-induced activities of nuclides produced in SS316 and F82H alloys used as the accelerator structural material were also measured to validate the measured cross sections comprehensively. It demonstrated that the measured activities of almost all the nuclides were in agreement with evaluated ones based on the measured cross sections within error. (author)

  15. Structural Analysis in a Conceptual Design Framework

    Science.gov (United States)

    Padula, Sharon L.; Robinson, Jay H.; Eldred, Lloyd B.

    2012-01-01

    Supersonic aircraft designers must shape the outer mold line of the aircraft to improve multiple objectives, such as mission performance, cruise efficiency, and sonic-boom signatures. Conceptual designers have demonstrated an ability to assess these objectives for a large number of candidate designs. Other critical objectives and constraints, such as weight, fuel volume, aeroelastic effects, and structural soundness, are more difficult to address during the conceptual design process. The present research adds both static structural analysis and sizing to an existing conceptual design framework. The ultimate goal is to include structural analysis in the multidisciplinary optimization of a supersonic aircraft. Progress towards that goal is discussed and demonstrated.

  16. Probabilistic Design of Offshore Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    Probabilistic design of structural systems is considered in this paper. The reliability is estimated using first-order reliability methods (FORM). The design problem is formulated as the optimization problem to minimize a given cost function such that the reliability of the single elements satisf......-analytical derivatives. Finally an example of probabilistic design of an offshore structure is considered.......Probabilistic design of structural systems is considered in this paper. The reliability is estimated using first-order reliability methods (FORM). The design problem is formulated as the optimization problem to minimize a given cost function such that the reliability of the single elements...

  17. Probabilistic Design of Offshore Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    1988-01-01

    Probabilistic design of structural systems is considered in this paper. The reliability is estimated using first-order reliability methods (FORM). The design problem is formulated as the optimization problem to minimize a given cost function such that the reliability of the single elements satisf......-analytical derivatives. Finally an example of probabilistic design of an offshore structure is considered.......Probabilistic design of structural systems is considered in this paper. The reliability is estimated using first-order reliability methods (FORM). The design problem is formulated as the optimization problem to minimize a given cost function such that the reliability of the single elements...

  18. Design of a grating for studying Smith-Purcell radiation and electron acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1989-01-01

    We describe work on the design fo a diffracton grating which we intend to use for studying the production of Smith-Purcell radiation and the acceleration of electrons. We have developed computer codes based on the solution of the appropriate Maxwell's equations. A specific grating profile is given which is feasible to construct and which supports enhanced surface accelerating modes. We examine the possibility of using the Smith-Purcell effect to make a beam position monitor. copyright 1989 American Institute of Physics

  19. Design of a grating for studying Smith-Purcell radiation and electron acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1989-01-01

    We describe work on the design of a diffraction grating which we intend to use for studying the production of Smith-Purcell radiation and the acceleration of electrons. We have developed computer codes based on the solution of the appropriate Maxwell's equations. A specific grating profile is given which is feasible to construct and which supports enhanced surface accelerating modes. We examine the possibility of using the Smith-Purcell effect to make a beam position monitor. 13 refs., 10 figs., 2 tabs

  20. Design consideration of relativistic klystron two-beam accelerator for suppression of beam-break-up

    International Nuclear Information System (INIS)

    Li, H.; Houck, T.L.; Yu, S.; Goffeney, N.

    1994-03-01

    It is demonstrated in this simulation study that by using the scheme of operating rf extraction structures on the betatron nodes of electron drive beam in conjunction with adequate de-Q-ing, appropriate choice of geometries for the rf structures (reducing transverse impedence) and/or staggered tuning we can suppress the overall growth of transverse instabilities to 4 e-folds in a relativistic klystron two-beam accelerator with 200 extraction cavities

  1. Tuners, microphonics, and control systems in superconducting accelerating structures

    International Nuclear Information System (INIS)

    Doolittle, L.R.

    1990-01-01

    Manufacturing tolerances, thermal stresses, acoustic noise, and cooling fluid pressure fluctuations all conspire to make the field in the cavity not precisely what the accelerator physicist has in mind. Tuners and control systems are the tools used to fight back: they regulate the field in the cavity to the desired magnitude and phase. Amplitude and phase stabilities are usually of greater concern in superconducting cavities than in copper cavities. The key to achieving a stable gradient and phase is feedback. A probe must be placed in the cavity itself to sense the present cavity status. Electronic control is then given the responsibility to correct for any measured disturbance. The electronic modulation of forward power has been implemented in a number of ways. Perhaps the easiest implementation to understand has two separate control loops, one for amplitude and one for phase (phase-amplitude loops). Other major electronic control devices include complex phasor modulator (CPM-amplitude loops), vector loop, and variable reactance. 'Slow' tuners are used when the tuning range of the 'fast' tuner plus electronic tuning is not enough to compensate for unpredictability or drift in the static frequency setting. (N.K.)

  2. Traveling wave accelerating structures with a large phase advance

    International Nuclear Information System (INIS)

    Paramonov, V.V.

    2012-01-01

    The cells RF parameters for the well known Disk Loaded Waveguide (DLW) are considered in higher pass bands of TM01 wave, providing operating phase advance between 180 o - 1230 o per cell. With an appropriate shape optimization and some additional elements proposed traveling wave structures with such large phase advance overlap the classical first band DLW in RF efficiency. Examples of proposed structures together with RF and dispersion properties are presented.

  3. Finite element simulation of structural performance on flexible pavements with stabilized base/treated subbase materials under accelerated loading.

    Science.gov (United States)

    2011-12-01

    Accelerated pavement testing (APT) has been increasingly used by state highway agencies in recent years for evaluating pavement structures and/or materials. However, running an APT experiment is expensive. It requires costly accelerated loading devic...

  4. Design and analysis of fractional order seismic transducer for displacement and acceleration measurements

    Science.gov (United States)

    Veeraian, Parthasarathi; Gandhi, Uma; Mangalanathan, Umapathy

    2018-04-01

    Seismic transducers are widely used for measurement of displacement, velocity, and acceleration. This paper presents the design of seismic transducer in the fractional domain for the measurement of displacement and acceleration. The fractional order transfer function for seismic displacement and acceleration transducer are derived using Grünwald-Letnikov derivative. Frequency response analysis of fractional order seismic displacement transducer (FOSDT) and fractional order seismic acceleration transducer (FOSAT) are carried out for different damping ratio with the different fractional order, and the maximum dynamic measurement range is identified. The results demonstrate that fractional order seismic transducer has increased dynamic measurement range and less phase distortion as compared to the conventional seismic transducer even with a lower damping ratio. Time response of FOSDT and FOSAT are derived analytically in terms of Mittag-Leffler function, the effect of fractional behavior in the time domain is evaluated from the impulse and step response. The fractional order system is found to have significantly reduced overshoot as compared to the conventional transducer. The fractional order seismic transducer design proposed in this paper is illustrated with a design example for FOSDT and FOSAT. Finally, an electrical equivalent of FOSDT and FOSAT is considered, and its frequency response is found to be in close agreement with the proposed fractional order seismic transducer.

  5. Research on cw electron accelerators using room-temperature rf structures: Annual report

    International Nuclear Information System (INIS)

    1986-01-01

    This joint NBS-Los Alamos project of ''Research on CW Electron Accelerators Using Room-Temperature RF Structures'' began seven years ago with the goal of developing a technology base for cw electron accelerators. In this report we describe our progress during FY 1986 and present our plans for completion of the project. First, however, it is appropriate to review the past contributions of the project, describe its status, and indicate its future benefits

  6. Flow induced vibrations of the CLIC X-Band accelerating structures

    CERN Document Server

    Charles, Tessa; Boland, Mark; Riddone, Germana; Samoshkin, Alexandre

    2011-01-01

    Turbulent cooling water in the Compact Linear Collider (CLIC) accelerating structures will inevitably induce some vibrations. The maximum acceptable amplitude of vibrations is small, as vibrations in the accelerating structure could lead to beam jitter and alignment difficulties. A Finite Element Analysis model is needed to identify the conditions under which turbulent instabilities and significant vibrations are induced. Due to the orders of magnitude difference between the fluid motion and the structure’s motion, small vibrations of the structure will not contribute to the turbulence of the cooling fluid. Therefore the resonant conditions of the cooling channels presented in this paper, directly identify the natural frequencies of the accelerating structures to be avoided under normal operating conditions. In this paper a 2D model of the cooling channel is presented finding spots of turbulence being formed from a shear layer instability. This effect is observed through direct visualization and wavelet ana...

  7. Comparison of experimental tests and theory for a rectangular two-channel dielectric wakefield accelerator structure

    Directory of Open Access Journals (Sweden)

    S. V. Shchelkunov

    2012-03-01

    Full Text Available Experimental results are reported for test beam acceleration and deflection in a two-channel, cm-scale, rectangular dielectric-lined wakefield accelerator structure energized by a 14-MeV drive beam. The dominant waveguide mode of the structure is at ∼30  GHz, and the structure is configured to exhibit a high transformer ratio (∼12∶1. Accelerated bunches in the narrow secondary channel of the structure are continuously energized via Cherenkov radiation that is emitted by a drive bunch moving in the wider primary channel. Observed energy gains and losses, transverse deflections, and changes in the test bunch charge distribution compare favorably with predictions of theory.

  8. The international linear collider. Technical design report. Vol. 3.2. Accelerator baseline design

    International Nuclear Information System (INIS)

    Adolphsen, Chris; Barone, Maura; Barish, Barry

    2013-01-01

    The following topics are dealt with: General parameters with layout and systems overview, main linac and SCRF technology, electron source, damping rings, ring to main linac, beam delivery system and machine detector interface, global accelerator control systems, availability with commissioning and operations, conventional facilities and siting, possible upgrade and staging options, project implementation planning, construction schedule, ILC TDR value estimate. (HSI)

  9. Preliminary Conceptual Design Report for the FACET-II Project at SLAC National Accelerator Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Mark [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2016-04-22

    Plasma wakefield acceleration has the potential to dramatically shrink the size and cost of particle accelerators. Research at the SLAC National Accelerator Laboratory has demonstrated that plasmas can provide 1,000 times the acceleration in a given distance compared with current technologies. Developing revolutionary and more efficient acceleration techniques that allow for an affordable high-energy collider is the focus of FACET, a National User Facility at SLAC. The existing FACET National User Facility uses part of SLAC’s two-mile-long linear accelerator to generate high-density beams of electrons and positrons. FACET-II is a new test facility to develop advanced acceleration and coherent radiation techniques with high-energy electron and positron beams. It is the only facility in the world with high energy positron beams. FACET-II provides a major upgrade over current FACET capabilities and the breadth of the potential research program makes it truly unique. It will synergistically pursue accelerator science that is vital to the future of both advanced acceleration techniques for High Energy Physics, ultra-high brightness beams for Basic Energy Science, and novel radiation sources for a wide variety of applications. The design parameters for FACET-II are set by the requirements of the plasma wakefield experimental program. To drive the plasma wakefield requires a high peak current, in excess of 10kA. To reach this peak current, the electron and positron design bunch size is 10μ by 10μ transversely with a bunch length of 10μ. This is more than 200 times better than what has been achieved at the existing FACET. The beam energy is 10 GeV, set by the Linac length available and the repetition rate is up to 30 Hz. The FACET-II project is scheduled to be constructed in three major stages. Components of the project discussed in detail include the following: electron injector, bunch compressors and linac, the positron system, the Sector 20 sailboat and W chicanes

  10. Overview of the Beam diagnostics in the Medaustron Accelerator:Design choices and test Beam commissioning

    CERN Document Server

    Osmic, F; Gyorgy, A; Kerschbaum, A; Repovz, M; Schwarz, S; Neustadt, W; Burtin, G

    2012-01-01

    The MedAustron centre is a synchrotron based accelerator complex for cancer treatment and clinical and non-clinical research with protons and light ions, currently under construction in Wiener Neustadt, Austria. The accelerator complex is based on the CERN-PIMMS study [1] and its technical implementation by the Italian CNAO foundation in Pavia [2]. The MedAustron beam diagnostics system is based on sixteen different monitor types (153 devices in total) and will allow measuring all relevant beam parameters from the source to the irradiation rooms. The monitors will have to cope with large intensities and energy ranges. Currently, one ion source, the low energy beam transfer line and the RFQ are being commissioned in the Injector Test Stand (ITS) at CERN. This paper gives an overview of all beam monitors foreseen for the MedAustron accelerator, elaborates some of the design choices and reports the first beam commissioning results from the ITS.

  11. Design concept for a CAMAC based beam tuner for the pelletron accelerator

    International Nuclear Information System (INIS)

    Gore, J.A.; Kulkarni, S.; Tambwekar, V.V.; Bhagwat, P.V.

    2003-01-01

    The 14 UD Pelletron accelerator has been in operation since 1989. It is a tandem accelerator, where negative ions are injected at maximum -300 kV and after the stripper in the terminal, positive ions achieve a maximum energy of 14(q+ I) MeV. The beam is transported from the ion source up to the target area with the help of various beam optic devices like quadrupoles and steerers. In this process the magnetic field of the focusing and steering magnets is adjusted with the help of voltage or current power supplies. At present the beam tuning process is operator driven. This paper describes a design concept of a CAMAC based beam tuner card that is implemented using an FPGA and which is under development at the Pelletron accelerator facility

  12. CPU-GPU hybrid accelerating the Zuker algorithm for RNA secondary structure prediction applications.

    Science.gov (United States)

    Lei, Guoqing; Dou, Yong; Wan, Wen; Xia, Fei; Li, Rongchun; Ma, Meng; Zou, Dan

    2012-01-01

    Prediction of ribonucleic acid (RNA) secondary structure remains one of the most important research areas in bioinformatics. The Zuker algorithm is one of the most popular methods of free energy minimization for RNA secondary structure prediction. Thus far, few studies have been reported on the acceleration of the Zuker algorithm on general-purpose processors or on extra accelerators such as Field Programmable Gate-Array (FPGA) and Graphics Processing Units (GPU). To the best of our knowledge, no implementation combines both CPU and extra accelerators, such as GPUs, to accelerate the Zuker algorithm applications. In this paper, a CPU-GPU hybrid computing system that accelerates Zuker algorithm applications for RNA secondary structure prediction is proposed. The computing tasks are allocated between CPU and GPU for parallel cooperate execution. Performance differences between the CPU and the GPU in the task-allocation scheme are considered to obtain workload balance. To improve the hybrid system performance, the Zuker algorithm is optimally implemented with special methods for CPU and GPU architecture. Speedup of 15.93× over optimized multi-core SIMD CPU implementation and performance advantage of 16% over optimized GPU implementation are shown in the experimental results. More than 14% of the sequences are executed on CPU in the hybrid system. The system combining CPU and GPU to accelerate the Zuker algorithm is proven to be promising and can be applied to other bioinformatics applications.

  13. CPU-GPU hybrid accelerating the Zuker algorithm for RNA secondary structure prediction applications

    Science.gov (United States)

    2012-01-01

    Background Prediction of ribonucleic acid (RNA) secondary structure remains one of the most important research areas in bioinformatics. The Zuker algorithm is one of the most popular methods of free energy minimization for RNA secondary structure prediction. Thus far, few studies have been reported on the acceleration of the Zuker algorithm on general-purpose processors or on extra accelerators such as Field Programmable Gate-Array (FPGA) and Graphics Processing Units (GPU). To the best of our knowledge, no implementation combines both CPU and extra accelerators, such as GPUs, to accelerate the Zuker algorithm applications. Results In this paper, a CPU-GPU hybrid computing system that accelerates Zuker algorithm applications for RNA secondary structure prediction is proposed. The computing tasks are allocated between CPU and GPU for parallel cooperate execution. Performance differences between the CPU and the GPU in the task-allocation scheme are considered to obtain workload balance. To improve the hybrid system performance, the Zuker algorithm is optimally implemented with special methods for CPU and GPU architecture. Conclusions Speedup of 15.93× over optimized multi-core SIMD CPU implementation and performance advantage of 16% over optimized GPU implementation are shown in the experimental results. More than 14% of the sequences are executed on CPU in the hybrid system. The system combining CPU and GPU to accelerate the Zuker algorithm is proven to be promising and can be applied to other bioinformatics applications. PMID:22369626

  14. Mechanical design of recirculating accelerator experiments for heavy-ion fusion

    International Nuclear Information System (INIS)

    Karpenko, V.

    1995-01-01

    Recirculating induction accelerators have been studied as a potential low cost driver for inertial fusion energy. At LLNL, we are developing a small (4.5-m diameter), scaled, experimental machine which will demonstrate many of the engineering solutions of a full scale driver. The small recirculator will accelerate singly ionized potassium ions from 80 to 320 keV and 2 to 8 mA, using electric dipoles for bending and permanent magnet quadrupoles for focusing in a compact periodic lattice. While very compact, and low cost, this design allows the investigation of most of the critical physics issues associated with space-charge-dominated beams in future IFE power plant drivers. This report describes the recirculator, its mechanical design, its vacuum design, and the process for aligning it. Additionally, a straight magnetic transport experiment is being carried out to test diagnostics and magnetic transport in preparation for the recirculator

  15. Effect of perturbation in low β proton accelerating structures

    International Nuclear Information System (INIS)

    Jule, W.E.; Baggett, D; Wechsler, P.; Gluckstern, R.L.

    1976-01-01

    In the first tank of the LAMPF 201 Linac it is desired to have a linear field distribution. One tries to achieve this by perturbing the first and last cells of the tank. A discussion is given of how perturbations in cell geometry in a periodic structure affect the field distribution in structures which correspond to low to intermediate values of β. It is shown that a geometric perturbation in one cell couples to many cells, and a method to obtain the coupling distribution from the geometric model is described. The necessary criteria to achieve the desired field distribution at LAMPF are discussed

  16. Theoretical problems in accelerator physics

    International Nuclear Information System (INIS)

    1992-01-01

    This report discusses the following research on accelerators: computational methods; higher order mode suppression in accelerators structures; overmoded waveguide components and application to SLED II and power transport; rf sources; accelerator cavity design for a B factory asymmetric collider; and photonic band gap cavities

  17. The Acceleration of Structural Microarchitectural Simulation via Scheduling

    Science.gov (United States)

    2006-11-01

    by Jason Blome and Jonathan Cheng. Ram Rangan and Julia S. Chen contributed several valuable modules and models used in this dissertation. And various...Transactions on Computer-Aided Design, 5(4), October 1986. [4] T. E. Anderson, D. E. Culler , and D. A. Patterson. A case for networks of workstations

  18. Fire Safety Design of Wood Structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2006-01-01

    Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections.......Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections....

  19. Design optimization applied in structural dynamics

    NARCIS (Netherlands)

    Akcay-Perdahcioglu, Didem; de Boer, Andries; van der Hoogt, Peter; Tiskarna, T

    2007-01-01

    This paper introduces the design optimization strategies, especially for structures which have dynamic constraints. Design optimization involves first the modeling and then the optimization of the problem. Utilizing the Finite Element (FE) model of a structure directly in an optimization process

  20. Large space structure damping design

    Science.gov (United States)

    Pilkey, W. D.; Haviland, J. K.

    1983-01-01

    Several FORTRAN subroutines and programs were developed which compute complex eigenvalues of a damped system using different approaches, and which rescale mode shapes to unit generalized mass and make rigid bodies orthogonal to each other. An analytical proof of a Minimum Constrained Frequency Criterion (MCFC) for a single damper is presented. A method to minimize the effect of control spill-over for large space structures is proposed. The characteristic equation of an undamped system with a generalized control law is derived using reanalysis theory. This equation can be implemented in computer programs for efficient eigenvalue analysis or control quasi synthesis. Methods to control vibrations in large space structure are reviewed and analyzed. The resulting prototype, using electromagnetic actuator, is described.

  1. Target design optimization for an electron accelerator driven subcritical facility with circular and square beam profiles.

    Energy Technology Data Exchange (ETDEWEB)

    Gohar, M. Y. A; Sofu, T.; Zhong, Z.; Belch, H.; Naberezhnev, D.; Nuclear Engineering Division

    2008-10-30

    A subcritical facility driven by an electron accelerator is planned at the Kharkov Institute of Physics and Technology (KIPT) in Ukraine for medical isotope production, materials research, training, and education. The conceptual design of the facility is being pursued through collaborations between ANL and KIPT. As part of the design effort, the high-fidelity analyses of various target options are performed with formulations to reflect the realistic configuration and the three dimensional geometry of each design. This report summarizes the results of target design optimization studies for electron beams with two different beam profiles. The target design optimization is performed via the sequential neutronic, thermal-hydraulic, and structural analyses for a comprehensive assessment of each configuration. First, a target CAD model is developed with proper emphasis on manufacturability to provide a basis for separate but consistent models for subsequent neutronic, thermal-hydraulic, and structural analyses. The optimizations are pursued for maximizing the neutron yield, streamlining the flow field to avoid hotspots, and minimizing the thermal stresses to increase the durability. In addition to general geometric modifications, the inlet/outlet channel configurations, target plate partitioning schemes, flow manipulations and rates, electron beam diameter/width options, and cladding material choices are included in the design optimizations. The electron beam interactions with the target assembly and the neutronic response of the subcritical facility are evaluated using the MCNPX code. the results for the electron beam energy deposition, neutron generation, and utilization in the subcritical pile are then used to characterize the axisymmetric heat generation profiles in the target assembly with explicit simulations of the beam tube, the coolant, the clad, and the target materials. Both tungsten and uranium are considered as target materials. Neutron spectra from tungsten

  2. Target design optimization for an electron accelerator driven subcritical facility with circular and square beam profiles

    International Nuclear Information System (INIS)

    Gohar, M.Y.A; Sofu, T.; Zhong, Z.; Belch, H.; Naberezhnev, D.

    2008-01-01

    A subcritical facility driven by an electron accelerator is planned at the Kharkov Institute of Physics and Technology (KIPT) in Ukraine for medical isotope production, materials research, training, and education. The conceptual design of the facility is being pursued through collaborations between ANL and KIPT. As part of the design effort, the high-fidelity analyses of various target options are performed with formulations to reflect the realistic configuration and the three dimensional geometry of each design. This report summarizes the results of target design optimization studies for electron beams with two different beam profiles. The target design optimization is performed via the sequential neutronic, thermal-hydraulic, and structural analyses for a comprehensive assessment of each configuration. First, a target CAD model is developed with proper emphasis on manufacturability to provide a basis for separate but consistent models for subsequent neutronic, thermal-hydraulic, and structural analyses. The optimizations are pursued for maximizing the neutron yield, streamlining the flow field to avoid hotspots, and minimizing the thermal stresses to increase the durability. In addition to general geometric modifications, the inlet/outlet channel configurations, target plate partitioning schemes, flow manipulations and rates, electron beam diameter/width options, and cladding material choices are included in the design optimizations. The electron beam interactions with the target assembly and the neutronic response of the subcritical facility are evaluated using the MCNPX code. the results for the electron beam energy deposition, neutron generation, and utilization in the subcritical pile are then used to characterize the axisymmetric heat generation profiles in the target assembly with explicit simulations of the beam tube, the coolant, the clad, and the target materials. Both tungsten and uranium are considered as target materials. Neutron spectra from tungsten

  3. Design and fabrication of topologically optimized structures;

    DEFF Research Database (Denmark)

    Feringa, Jelle; Søndergaard, Asbjørn

    2012-01-01

    Integral structural optimization and fabrication seeks the synthesis of two original approaches; that of topological optimization (TO) and robotic hotwire cutting (HWC) (Mcgee 2011). TO allows for the reduction of up to 70% of the volume of concrete to support a given structure (Sondergaard...... & Dombernowsky 2011). A strength of the method is that it allows to come up with structural designs that lie beyond the grasp of traditional means of design. A design space is a discretized volume, delimiting where the optimization will take place. The number of cells used to discretize the design space thus...

  4. Hadron cancer therapy complex employing non-scaling FFAG accelerator and fixed field gantry design

    CERN Document Server

    Keil, Eberhard; Trbojevic, D

    2007-01-01

    Non-scaling FFAG rings for cancer hadron therapy offer reduced physical aperture and large dynamic aperture as compared with scaling FFAGs. The variation of tune with energy implies the crossing of resonances during acceleration. Our design avoids intrinsic resonances, although imperfection resonances must be, and can be, crossed. We consider a system of three non-scaling FFAG rings for cancer therapy with 250 MeV protons and 400 MeV/u carbon ions. Hadrons are accelerated in a common RFQ and linear accelerator, and injected into the FFAG rings at .. .. . H+/C6+ ions are accelerated in the two smaller/larger rings to 31 and 250 MeV/68.8 and 400 MeV/u kinetic energy, respectively. The lattices consist of doublet cells with a straight section for RF cavities. The gantry with triplet cells accepts the whole required momentum range at fixed field. This unique design uses either high temperature super-conductors or super-conducting magnets reducing gantry size and weight. Elements with variable field at beginning a...

  5. Hadron cancer therapy complex using nonscaling fixed field alternating gradient accelerator and gantry design

    Directory of Open Access Journals (Sweden)

    E. Keil

    2007-05-01

    Full Text Available Nonscaling fixed field alternating gradient (FFAG rings for cancer hadron therapy offer reduced physical aperture and large dynamic aperture as compared to scaling FFAGs. The variation of tune with energy implies the crossing of resonances during acceleration. Our design avoids intrinsic resonances, although imperfection resonances must be crossed. We consider a system of three nonscaling FFAG rings for cancer therapy with 250 MeV protons and 400   MeV/u carbon ions. Hadrons are accelerated in a common radio frequency quadrupole and linear accelerator, and injected into the FFAG rings at v/c=0.1294. H^{+}/C^{6+} ions are accelerated in the two smaller/larger rings to 31 and 250  MeV/68.8 and 400   MeV/u kinetic energy, respectively. The lattices consist of doublet cells with a straight section for rf cavities. The gantry with triplet cells accepts the whole required momentum range at fixed field. This unique design uses either high-temperature superconductors or superconducting magnets reducing gantry magnet size and weight. Elements with a variable field at the beginning and at the end set the extracted beam at the correct position for a range of energies.

  6. Optimal design of constant-stress accelerated degradation tests using the M-optimality criterion

    International Nuclear Information System (INIS)

    Wang, Han; Zhao, Yu; Ma, Xiaobing; Wang, Hongyu

    2017-01-01

    In this paper, we propose the M-optimality criterion for designing constant-stress accelerated degradation tests (ADTs). The newly proposed criterion concentrates on the degradation mechanism equivalence rather than evaluation precision or prediction accuracy which is usually considered in traditional optimization criteria. Subject to the constraints of total sample number, test termination time as well as the stress region, an optimum constant-stress ADT plan is derived by determining the combination of stress levels and the number of samples allocated to each stress level, when the degradation path comes from inverse Gaussian (IG) process model with covariates and random effects. A numerical example is presented to verify the robustness of our proposed optimum plan and compare its efficiency with other test plans. Results show that, with a slightly relaxed requirement of evaluation precision and prediction accuracy, our proposed optimum plan reduces the dispersion of the estimated acceleration factor between the usage stress level and a higher accelerated stress level, which makes an important contribution to reliability demonstration and assessment tests. - Highlights: • We establish the necessary conditions for degradation mechanism equivalence of ADTs. • We propose the M-optimality criterion for designing constant-stress ADT plans. • The M-optimality plan reduces the dispersion of the estimated accelerated factors. • An electrical connector with its stress relaxation data is used for illustration.

  7. FMIT accelerator vacuum system

    International Nuclear Information System (INIS)

    Machalek, M.D.; Meyer, E.A.; Price, L.S.

    1979-01-01

    The Fusion Materials Irradiation Test (FMIT) Facility accelerator is being designed to continuously accelerate 100-mA deuterons to 25 MeV. High vacuum pumping of the accelerator structure and beam lines will be done by ion pumps and titanium sublimation pumps. The design of the roughing system includes a Roots blower/mechanical pump package. For economy the size of the system has been designed to operate at 10 -6 torr, where beam particle scattering on residual gases is negligible. For minimum maintenance in this neutron factory, the FMIT vacuum system is designed from the point of view of simplicity and reliability

  8. Design of SSC collider structures

    International Nuclear Information System (INIS)

    Monsees, J.E.

    1994-01-01

    The authors would like to set the record straight. To date, underground construction contracts on the SSC main ring have been bid at a savings of $77 million dollars or 33 percent below the baseline cost estimate. The SSC is the largest single underground project ever built anywhere in the world. When completed it will have approximately 70 miles of tunnels, 60 shafts, two huge underground experiment halls -- each the size of a football stadium -- and numerous other structures, each of which would be considered a major facility on any other project

  9. Challenges to self-acceleration in modified gravity from gravitational waves and large-scale structure

    Directory of Open Access Journals (Sweden)

    Lucas Lombriser

    2017-02-01

    Full Text Available With the advent of gravitational-wave astronomy marked by the aLIGO GW150914 and GW151226 observations, a measurement of the cosmological speed of gravity will likely soon be realised. We show that a confirmation of equality to the speed of light as indicated by indirect Galactic observations will have important consequences for a very large class of alternative explanations of the late-time accelerated expansion of our Universe. It will break the dark degeneracy of self-accelerated Horndeski scalar–tensor theories in the large-scale structure that currently limits a rigorous discrimination between acceleration from modified gravity and from a cosmological constant or dark energy. Signatures of a self-acceleration must then manifest in the linear, unscreened cosmological structure. We describe the minimal modification required for self-acceleration with standard gravitational-wave speed and show that its maximum likelihood yields a 3σ poorer fit to cosmological observations compared to a cosmological constant. Hence, equality between the speeds challenges the concept of cosmic acceleration from a genuine scalar–tensor modification of gravity.

  10. Challenges to self-acceleration in modified gravity from gravitational waves and large-scale structure

    Science.gov (United States)

    Lombriser, Lucas; Lima, Nelson A.

    2017-02-01

    With the advent of gravitational-wave astronomy marked by the aLIGO GW150914 and GW151226 observations, a measurement of the cosmological speed of gravity will likely soon be realised. We show that a confirmation of equality to the speed of light as indicated by indirect Galactic observations will have important consequences for a very large class of alternative explanations of the late-time accelerated expansion of our Universe. It will break the dark degeneracy of self-accelerated Horndeski scalar-tensor theories in the large-scale structure that currently limits a rigorous discrimination between acceleration from modified gravity and from a cosmological constant or dark energy. Signatures of a self-acceleration must then manifest in the linear, unscreened cosmological structure. We describe the minimal modification required for self-acceleration with standard gravitational-wave speed and show that its maximum likelihood yields a 3σ poorer fit to cosmological observations compared to a cosmological constant. Hence, equality between the speeds challenges the concept of cosmic acceleration from a genuine scalar-tensor modification of gravity.

  11. Structural elements design manual working with Eurocodes

    CERN Document Server

    Draycott, Trevor

    2009-01-01

    Structural Elements Design Manual: Working With Eurocodes is the structural engineers 'companion volume' to the four Eurocodes on the structural use of timber, concrete, masonry and steelwork. For the student at higher technician or first degree level it provides a single source of information on the behaviour and practical design of the main elements of the building structure. With plenty of worked examples and diagrams, it is a useful textbook not only for students of structural and civil engineering, but also for those on courses in related subjects such as

  12. Phononic band gap structures as optimal designs

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Sigmund, Ole

    2003-01-01

    In this paper we use topology optimization to design phononic band gap structures. We consider 2D structures subjected to periodic loading and obtain the distribution of two materials with high contrast in material properties that gives the minimal vibrational response of the structure. Both in...

  13. The Technique for the Numerical Tolerances Estimations in the Construction of Compensated Accelerating Structures

    CERN Document Server

    Paramonov, V V

    2004-01-01

    The requirements to the cells manufacturing precision and tining in the multi-cells accelerating structures construction came from the required accelerating field uniformity, based on the beam dynamics demands. The standard deviation of the field distribution depends on accelerating and coupling modes frequencies deviations, stop-band width and coupling coefficient deviations. These deviations can be determined from 3D fields distribution for accelerating and coupling modes and the cells surface displacements. With modern software it can be done separately for every specified part of the cell surface. Finally, the cell surface displacements are defined from the cell dimensions deviations. This technique allows both to define qualitatively the critical regions and to optimize quantitatively the tolerances definition.

  14. RF structure design of the China Material Irradiation Facility RFQ

    Science.gov (United States)

    Li, Chenxing; He, Yuan; Xu, Xianbo; Zhang, Zhouli; Wang, Fengfeng; Dou, Weiping; Wang, Zhijun; Wang, Tieshan

    2017-10-01

    The radio frequency structure design of the radio frequency quadrupole (RFQ) for the front end of China Material Irradiation Facility (CMIF), which is an accelerator based neutron irradiation facility for fusion reactor material qualification, has been completed. The RFQ is specified to accelerate 10 mA continuous deuteron beams from the energies of 20 keV/u to 1.5 MeV/u within the vane length of 5250 mm. The working frequency of the RFQ is selected to 162.5 MHz and the inter-vane voltage is set to 65 kV. Four-vane cavity type is selected and the cavity structure is designed drawing on the experience of China Initiative Accelerator Driven System (CIADS) Injector II RFQ. In order to reduce the azimuthal asymmetry of the field caused from errors in fabrication and assembly, a frequency separation between the working mode and its nearest dipole mode is reached to 17.66 MHz by utilizing 20 pairs of π-mode stabilizing loops (PISLs) distributed along the longitudinal direction with equal intervals. For the purpose of tuning, 100 slug tuners were introduced to compensate the errors caused by machining and assembly. In order to obtain a homogeneous electrical field distribution along cavity, vane cutbacks are introduced and output endplate is modified. Multi-physics study of the cavity with radio frequency power and water cooling is performed to obtain the water temperature tuning coefficients. Through comparing to the worldwide CW RFQs, it is indicated that the power density of the designed structure is moderate for operation under continuous wave (CW) mode.

  15. Site layout and balance of plant design for an accelerator-driven materials processing complex

    Energy Technology Data Exchange (ETDEWEB)

    Cunliffe, J.; Taussig, R.; Ghose, S. [Bechtel Corporation, San Francisco, CA (United States)] [and others

    1995-10-01

    High energy proton beam accelerators are under consideration for use in radioisotope production, surplus weapons material destruction, radioactive waste transmutation, and thorium-based energy conversion cycles. While there are unique aspects to each of these applications that must be accommodated in the design of the associated facility, all share a set of fundamental characteristics that in large measure dictate the site layout features and many balance-of-plant (BOP) design requirements found to be common to all. This paper defines these key design determinants and goes on to discuss the manner in which they have been accommodated in the pre-conceptual design for a particular materials production application. An estimate of the costs associated with this BOP design is also presented with the aim of guiding future evaluations where the basic plant designs are similar to that of this specific case.

  16. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    International Nuclear Information System (INIS)

    Krause, David L.; Kantzos, Pete T.

    2006-01-01

    For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110-watt Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head

  17. Traversal Caches: A Framework for FPGA Acceleration of Pointer Data Structures

    Directory of Open Access Journals (Sweden)

    James Coole

    2010-01-01

    Full Text Available Field-programmable gate arrays (FPGAs and other reconfigurable computing (RC devices have been widely shown to have numerous advantages including order of magnitude performance and power improvements compared to microprocessors for some applications. Unfortunately, FPGA usage has largely been limited to applications exhibiting sequential memory access patterns, thereby prohibiting acceleration of important applications with irregular patterns (e.g., pointer-based data structures. In this paper, we present a design pattern for RC application development that serializes irregular data structure traversals online into a traversal cache, which allows the corresponding data to be efficiently streamed to the FPGA. The paper presents a generalized framework that benefits applications with repeated traversals, which we show can achieve between 7x and 29x speedup over pointer-based software. For applications without strictly repeated traversals, we present application-specialized extensions that benefit applications with highly similar traversals by exploiting similarity to improve memory bandwidth and execute multiple traversals in parallel. We show that these extensions can achieve a speedup between 11x and 70x on a Virtex4 LX100 for Barnes-Hut n-body simulation.

  18. Design of a low-cost, compact SRF accelerator for flue gas and wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-04-01

    Funding is being requested pursuant to a proposal that was submitted and reviewed through the Portfolio Analysis and Management System (PAMS). PAMS Proposal ID: 222439. The proposed project consists of the design of a novel superconducting continuous-wave accelerator capable of providing a beam current of ~1 A at an energy of 1-2 MeV for the treatment of flue gases and wastewater streams. The novel approach consists on studying the feasibility of using a single-cell Nb cavity coated with a thin Nb3Sn layer of the inner surface and conductively cooled by to 4.2 K by cryocoolers inside a compact cryomodule. The proposed study will include beam transport simulations, thermal and mechanical engineering analysis of the cryomodule and a cost analysis for both the fabrications costs and the operational and maintenance costs of such accelerator. The outcome of the project will be a report summarizing the analysis and results from the design study.

  19. Design and fabrication of the 'ITER-like' SINGAP D- acceleration system

    International Nuclear Information System (INIS)

    Massmann, P.; Esch, H.P.L. de; Hemsworth, R.S.; Svensson, L.

    2005-01-01

    To demonstrate ITER NBI (1 MV, 40 A) relevant beam optics in the Cadarache 1 MV, 100 mA test bed, a new D - beam source system has been put into operation. The system retains a maximum of the ITER SINGAP key parameters, e.g. the perveance matched D - current density at 1 MeV is 20 mA/cm 2 . The accelerator parameters are identical to the ITER SINGAP design, aiming at a near parallel 1 MeV beam of 5 mrad divergence. The design is aimed at also demonstrating SINGAP 'on to off-axis' beam steering by a simple transverse displacement of the post-acceleration electrode. First beams up to 850 keV have been obtained after only 4 weeks of commissioning

  20. Concepts for the magnetic design of the MITICA neutral beam test facility ion accelerator.

    Science.gov (United States)

    Chitarin, G; Agostinetti, P; Marconato, N; Marcuzzi, D; Sartori, E; Serianni, G; Sonato, P

    2012-02-01

    The megavolt ITER injector concept advancement neutral injector test facility will be constituted by a RF-driven negative ion source and by an electrostatic Accelerator, designed to produce a negative Ion with a specific energy up to 1 MeV. The beam is then neutralized in order to obtain a focused 17 MW neutral beam. The magnetic configuration inside the accelerator is of crucial importance for the achievement of a good beam efficiency, with the early deflection of the co-extracted and stripped electrons, and also of the required beam optic quality, with the correction of undesired ion beamlet deflections. Several alternative magnetic design concepts have been considered, comparing in detail the magnetic and beam optics simulation results, evidencing the advantages and drawbacks of each solution both from the physics and engineering point of view.

  1. Thermally optimized lithium neutron producing target design for accelerator-based BNCT

    International Nuclear Information System (INIS)

    Park Shane; Joo Hyeong Min; Jang Byeong Ill; Jeun, Gyoodong; Kim Jong Kyung; Chai, Jong Seo

    2006-01-01

    In accelerator-based Boron Neutron Capture Therapy (BNCT), 7 Li(p,n) 7 Be reaction is prevalently used as a neutron source. However, lithium has a very low melting point and poor thermal conductivity. Thus lithium target needs an efficient cooling. In this study, ways of increasing proton beam diameter and slanting target are proposed to reduce the heat density of lithium target. Thermal analysis on the lithium target design shows that water cooling is feasible if the proton beam diameter and target slopes are in the available range of the contour plots generated from this study. On the basis of the thermal analysis, the prototype of target system was designed and manufactured. Full-model thermal analysis and temperature measuring experiment were subsequently performed. The calculated temperature distribution coincided with the contour plots and the experimental results. These results will be used in the manufacture of the prototype accelerator-based BNCT facility at Hanyang University. (author)

  2. Accelerating Full Configuration Interaction Calculations for Nuclear Structure

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chao; Sternberg, Philip; Maris, Pieter; Ng, Esmond; Sosonkina, Masha; Le, Hung Viet; Vary, James; Yang, Chao

    2008-04-14

    One of the emerging computational approaches in nuclear physics is the full configuration interaction (FCI) method for solving the many-body nuclear Hamiltonian in a sufficiently large single-particle basis space to obtain exact answers - either directly or by extrapolation. The lowest eigenvalues and correspondingeigenvectors for very large, sparse and unstructured nuclear Hamiltonian matrices are obtained and used to evaluate additional experimental quantities. These matrices pose a significant challenge to the design and implementation of efficient and scalable algorithms for obtaining solutions on massively parallel computer systems. In this paper, we describe the computational strategies employed in a state-of-the-art FCI code MFDn (Many Fermion Dynamics - nuclear) as well as techniques we recently developed to enhance the computational efficiency of MFDn. We will demonstrate the current capability of MFDn and report the latest performance improvement we have achieved. We will also outline our future research directions.

  3. Design of hybrid electron linac with standing wave buncher and traveling wave structure

    International Nuclear Information System (INIS)

    Kutsaev, S.V.; Sobenin, N.P.; Smirnov, A.Yu.; Kamenschikov, D.S.; Gusarova, M.A.; Nikolskiy, K.I.; Zavadtsev, A.A.; Lalayan, M.V.

    2011-01-01

    A disk-loaded waveguide (DLW) is the most common structure for compact linear accelerators working in a traveling wave (TW) regime. Among its advantages are high shunt impedance and manufacturing simplicity. The other popular structure is an on-axis coupled bi-periodical accelerating structure (BAS) that works in standing wave (SW) regime. Both the standing and the traveling wave regimes have their own advantages and disadvantages. The design of the hybrid accelerator with SW buncher and TW accelerating section presented in this paper unites the advantages of both regimes. For example, the buncher in the hybrid accelerator is shorter than in a pure TW accelerator, and it requires no solenoid; this structure is more technologically convenient as it does not require a circulator. The other way to combine the advantages of DLW and BAS is to design a magnetic coupled disk-loaded waveguide (DLW-M). This paper also presents the results of a survey study that analyzed the electrodynamical parameters of such a structure and compared them with those of DLW. The experimental data is also presented. Higher order modes, multipacting discharge and thermal simulations show that DLW-M structure is more preferable to classical DLW.

  4. Cryogenic studies of rf accelerating structures, vintage 1978

    International Nuclear Information System (INIS)

    Liska, D.; Uher, J.; Potter, J.

    1986-01-01

    Cryogenically cooled rf cavity studies were undertaken at Los Alamos in 1978 to test the effectiveness of reduced temperature on the Q-enhancement of 450-MHz drift-tube linac structures. A complete facility was set up to do high power tests, not only at liquid nitrogen (LN 2 ) temperature but with liquid hydrogen (LH 2 ) as well. The cavity, Dewar, klystron test stand, and a remote outdoor enclosure were constructed. Hydrogen safety approval for the tests was obtained. Unfortunately, the hydrogen tests were never done. However, the cavity was tested at high power in LN 2 and a Q-enhancement of 2.02 was recorded, compared to 2.7 expected theoretically. This work is now continuing with improved measuring techniques using some of the same apparatus. It is the purpose of this paper to report on the early work and to reference its continuation today

  5. Structural Design of Ares V Interstage Composite Structure

    Science.gov (United States)

    Sleigh, David W.; Sreekantamurthy, Thammaiah; Kosareo, Daniel N.; Martin, Robert A.; Johnson, Theodore F.

    2011-01-01

    Preliminary and detailed design studies were performed to mature composite structural design concepts for the Ares V Interstage structure as a part of NASA s Advanced Composite Technologies Project. Aluminum honeycomb sandwich and hat-stiffened composite panel structural concepts were considered. The structural design and analysis studies were performed using HyperSizer design sizing software and MSC Nastran finite element analysis software. System-level design trade studies were carried out to predict weight and margins of safety for composite honeycomb-core sandwich and composite hat-stiffened skin design concepts. Details of both preliminary and detailed design studies are presented in the paper. For the range of loads and geometry considered in this work, the hat-stiffened designs were found to be approximately 11-16 percent lighter than the sandwich designs. A down-select process was used to choose the most favorable structural concept based on a set of figures of merit, and the honeycomb sandwich design was selected as the best concept based on advantages in manufacturing cost.

  6. Numerical computation methods for magnet design of spectrometer, accelerator and beam transport systems

    International Nuclear Information System (INIS)

    Fan Mingwu; Maio Yixin

    1986-01-01

    High calculation accuracy is expected in the design of spectrometer, accelerator or beam transport systems. Three dimensional electromagnetic field computation is needed in some cases. In solving these problems, numerical computation methods have been dominating in the area. Advantages and disadvantages among the methods are discussed and errors between computed and measured values are analysised. The application of making full use of these methods is discussed based on some practical models

  7. Initial development of PC software base for the design of electromagnetic component in accelerator

    International Nuclear Information System (INIS)

    Zhang Tianjue; Fan Mingwu; Zhang Manhuai; Huang Jijie; Dai Xiaoming; Chu Chengjie

    2000-01-01

    The initial development of PC software base for the design of electromagnetic component in accelerator is described. The developing studies include the transplantation and development of POISSON/SUPERFISH, RELAX 3D, TRANSPORT, RAYTRACE, MAD and PARMELA, and the modification of software DE2D, DE3D, CYCCAE and CYCCEN, which are developed in China Institute of Atomic Energy. Some application in the actual engineering is also introduced

  8. Dynamic analysis and design of offshore structures

    CERN Document Server

    Chandrasekaran, Srinivasan

    2015-01-01

    This book  attempts to provide readers with an overall idea of various types of offshore platform geometries. It covers the various environmental loads encountered by these structures, a detailed description of the fundamentals of structural dynamics in a class-room style, estimate of damping in offshore structures and their applications in the preliminary analysis and design. Basic concepts of structural dynamics are emphasized through simple illustrative examples and exercises. Design methodologies and guidelines, which are FORM based concepts are explained through a few applied example structures. Each chapter also has tutorials and exercises for self-learning. A dedicated chapter on stochastic dynamics will help the students to extend the basic concepts of structural dynamics to this advanced domain of research. Hydrodynamic response of offshore structures with perforated members is one of the recent research applications, which is found to be one of the effective manner of retrofitting offshore structur...

  9. Automated analysis and design of complex structures

    International Nuclear Information System (INIS)

    Wilson, E.L.

    1977-01-01

    The present application of optimum design appears to be restricted to components of the structure rather than to the total structural system. Since design normally involved many analysis of the system any improvement in the efficiency of the basic methods of analysis will allow more complicated systems to be designed by optimum methods. The evaluation of the risk and reliability of a structural system can be extremely important. Reliability studies have been made of many non-structural systems for which the individual components have been extensively tested and the service environment is known. For such systems the reliability studies are valid. For most structural systems, however, the properties of the components can only be estimated and statistical data associated with the potential loads is often minimum. Also, a potentially critical loading condition may be completely neglected in the study. For these reasons and the previous problems associated with the reliability of both linear and nonlinear analysis computer programs it appears to be premature to place a significant value on such studies for complex structures. With these comments as background the purpose of this paper is to discuss the following: the relationship of analysis to design; new methods of analysis; new of improved finite elements; effect of minicomputer on structural analysis methods; the use of system of microprocessors for nonlinear structural analysis; the role of interacting graphics systems in future analysis and design. This discussion will focus on the impact of new, inexpensive computer hardware on design and analysis methods

  10. Effects of RF breakdown on the beam in a CLIC prototype accelerator structure

    CERN Document Server

    Palaia, A; Ruber, R; Ziemann, V; Farabolini, W

    2013-01-01

    Understanding the effects of RF breakdown in high-gradient accelerator structures on the accelerated beam is an extremely relevant aspect in the development of the Compact Linear Collider (CLIC) and is one of the main issues addressed at the Two-beam Test Stand at the CLIC Test Facility 3 at CERN. During a RF breakdown large electro-magnetic fields are generated and produce parasitic magnetic fields which interact with the accelerated beam affecting its orbit and energy. We discuss here measurements of such effects observed on an electron beam accelerated in a CLIC prototype structure. Measurements of the trajectory of bunch-trains on a nanosecond time-scale showed fast changes in correspondence of breakdown which we compare with measurements of the relative beam spots on a scintillating screen. We identify different breakdown scenarios for which we offer an explanation based also on measurements of the power at the input and output ports of the accelerator structure. Finally we present the distribution of th...

  11. The magnetic structure of the isochronous accelerator DC-72. Author-review of the Thesis

    International Nuclear Information System (INIS)

    Keniz, J.

    2009-06-01

    The formation of DC-72 cyclotron magnetic field was carried out. The modeling and computer simulations of the magnet elements were used for preliminary choice of a cyclotron magnet structure. For exact isochronous magnetic field formation, at the nominal working point and correction of the field first harmonic, side sectors shims have been applied. The measured magnetic fields of the main magnet and correcting coils at different levels are used as inputs to the computer program in order to simulate different regimes of the working diagram. Satisfactory results have been obtained from calculations of the beam dynamics at the chosen working regimes with appropriate magnetic fields which were shaped with correcting coils and subsequently measured. This also allowed for mutual comparison of the simulated and measured data. The isochronous cyclotron DC-72 is intended to accelerate ions from H - (A/Z=1, W=72 MeV/u) up to 129 Xe 18+ (A/Z=7.167, W=2.7 MeV/u). The cyclotron magnet has the pole of 2.6 m diameter and provides the working magnetic fields in the range from 0.9 T to 1.51 T for the given modes of the acceleration. A preliminary design of the magnetic field has been accomplished by the help of a model of the magnet which has been made in the scale 1:5 and mathematically simulated. The results achieved from the measurements performed upon the magnetic field of the final product are presented, too. (Author)

  12. Particle optics and accelerator modeling software for industrial and laboratory beamline design

    International Nuclear Information System (INIS)

    Gillespie, G.H.; Hill, B.W.

    1998-01-01

    The expanding variety of accelerator applications in research and industry places increased demands upon scientists and engineers involved in developing new accelerator and beamline designs. Computer codes for particle optics simulation have always played an important role in the design process and enhanced software tools offer the promise of improved productivity for beamline designers. This paper summarizes recent work on the development of advanced graphic user interface (GUI) software components, that can be linked directly to many of the standard particle optics programs used in the accelerator community, and which are aimed at turning that promise of improved productivity into a reality. An object oriented programming (OOP) approach has been adopted and a number of GUI components have been developed that run on several different operating systems. The emphasis is on assisting users in the setup and running of the optics programs without requiring any knowledge of the format, syntax, or similar requirements of the input. The components are being linked with several popular optics programs, including TRANSPORT, TURTLE, TRACE 3-D and PARMILA, to form integrated easy-to-use applications. Several advanced applications linking the GUI components with Lie algebra and other high-order simulation codes, as well as system level and facility modeling codes, are also under development. An overview of the work completed to date is presented, and examples of the new tools running on the Windows 95 operating system are illustrated. (orig.)

  13. Structured Annual Faculty Review Program Accelerates Professional Development and Promotion

    Directory of Open Access Journals (Sweden)

    Stanley J. Robboy MD

    2017-03-01

    Full Text Available This retrospective observational study on faculty development analyzes the Duke University Pathology Department’s 18-year experience with a structured mentoring program involving 51 junior faculty members. The majority had MD degrees only (55%. The percentage of young women faculty hires before 1998 was 25%, increasing to 72% after 2005. Diversity also broadened from 9% with varied heritages before 1998 to 37% since then. The mentoring process pivoted on an annual review process. The reviews generally helped candidates focus much earlier, identified impediments they individually felt, and provided new avenues to gain a national reputation for academic excellence. National committee membership effectively helped gain national exposure. Thirty-eight percent of the mentees served on College of American Pathologists (CAP committees, exponential multiples of any other national society. Some used CAP resources to develop major programs, some becoming nationally and internationally recognized for their academic activities. Several faculty gained national recognition as thought leaders for publishing about work initiated to serve administrative needs in the Department. The review process identified the need for more protected time for research, issues with time constraints, and avoiding exploitation when collaborating with other departments. This review identified a rigorous faculty mentoring and review process that included annual career counseling, goal-oriented academic careers, monitored advancement to promotion, higher salaries, and national recognition. All contributed to high faculty satisfaction and low faculty turnover. We conclude that a rigorous annual faculty review program and its natural sequence, promotion, can greatly foster faculty satisfaction.

  14. Superconducting accelerating structure for particle velocities from 0.12 to 0.23 c

    International Nuclear Information System (INIS)

    Shepard, K.W.; Zinkann, G.P.

    1983-01-01

    A split-ring resonator has been designed for an optimum particle velocity #betta# = v/c = 0.16 and a frequency of 145.5 MHz. The ratio of peak-surface electric field to effective accelerating field in the resonator has been reduced 20% from the value obtained in previously developed split-ring resonators. The improved design results from the use of elliptically-sectioned loading arms and drift tubes, which have been enlarged to reduce peak-surface fields and also shaped to eliminate beam-steering effects in the resonator. All fabrication problems presented by the more-complex geometry have been solved, and a prototype superconducting niobium resonator has been completed. An accelerating field of 3.3 MV/m at 4 watts rf input has been so far achieved, corresponding to an effective accelerating potential of 1.17 MV per resonator

  15. Development of low-loss cryo-accelerating structure with high-purity copper

    Science.gov (United States)

    Iino, Akihiro; Yamaguchi, Seiya; Shintomi, Takakazu; Higo, Toshiyasu; Funahashi, Yoshisato; Matsumoto, Shuji; Michizono, Shinichiro; Ueno, Kenji; Endo, Katsumi

    2017-09-01

    In this paper, the development of an accelerating structure with high-purity copper operated at approximately 20 K is described. The aim is to obtain a dramatic increase in the quality factor (Q factor), which is an important parameter as regards enhancement of the acceleration gradient in a normal-conducting accelerating structure that has been operated at room temperature in the past. First, the Q factors of pillbox cavities comprised of two types of copper with different purities (99.99% and 99.99998%) were measured, at room temperature (300 K) and at a relatively low temperature (20 K); the resultant ratios, Q0(20 K)/Q0(300 K), were then compared with calculated values. Hence, it was found that the experimental and calculated values agree to within several percent, and converge to a constant value (approximately 5.3) when the residual resistance ratio is above 500. Next, a C-band accelerating structure was fabricated using a copper material having a purity of 99.99998%, and high-power testing of the structure was conducted at 20 K. Hence, it was found that the accelerating gradient Eacc reaches 30.9 MV/m with a 1.0- μs pulse width and 50-Hz repetition rate. In the high-power test, it was revealed that the radiation dose rate for C-band structure (20 K) was about two orders of magnitude lower than that for S-band structure (303 K) under the same conditions. Further, the magnitude of the dark current generated in this structure was estimated to be several femtoamps, which was below the detection limit. This finding was based on the assumption that the dark current magnitude is proportional to the radiation dose; however, no dark current was observed.

  16. Design and Optimization of Large Accelerator Systems through High-Fidelity Electromagnetic Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Cho; Akcelik, Volkan; Candel, Arno; Chen, Sheng; Ge, Lixin; Kabel, Andreas; Lee, Lie-Quan; Li, Zenghai; Prudencio, Ernesto; Schussman, Greg; Uplenchwar1, Ravi; Xiao1, Liling; Ko1, Kwok; Austin, T.; Cary, J.R.; Ovtchinnikov, S.; Smith, D.N.; Werner, G.R.; Bellantoni, L.; /SLAC /TechX Corp. /Fermilab

    2008-08-01

    SciDAC1, with its support for the 'Advanced Computing for 21st Century Accelerator Science and Technology' (AST) project, witnessed dramatic advances in electromagnetic (EM) simulations for the design and optimization of important accelerators across the Office of Science. In SciDAC2, EM simulations continue to play an important role in the 'Community Petascale Project for Accelerator Science and Simulation' (ComPASS), through close collaborations with SciDAC CETs/Institutes in computational science. Existing codes will be improved and new multi-physics tools will be developed to model large accelerator systems with unprecedented realism and high accuracy using computing resources at petascale. These tools aim at targeting the most challenging problems facing the ComPASS project. Supported by advances in computational science research, they have been successfully applied to the International Linear Collider (ILC) and the Large Hadron Collider (LHC) in High Energy Physics (HEP), the JLab 12-GeV Upgrade in Nuclear Physics (NP), as well as the Spallation Neutron Source (SNS) and the Linac Coherent Light Source (LCLS) in Basic Energy Sciences (BES).

  17. Design and Optimization of Large Accelerator Systems through High-Fidelity Electromagnetic Simulations

    International Nuclear Information System (INIS)

    Ng, Cho; Akcelik, Volkan; Candel, Arno; Chen, Sheng; Ge, Lixin; Kabel, Andreas; Lee, Lie-Quan; Li, Zenghai; Prudencio, Ernesto; Schussman, Greg; Uplenchwar1, Ravi; Xiao1, Liling; Ko1, Kwok; Austin, T.; Cary, J.R.; Ovtchinnikov, S.; Smith, D.N.; Werner, G.R.; Bellantoni, L.; TechX Corp.; Fermilab

    2008-01-01

    SciDAC1, with its support for the 'Advanced Computing for 21st Century Accelerator Science and Technology' (AST) project, witnessed dramatic advances in electromagnetic (EM) simulations for the design and optimization of important accelerators across the Office of Science. In SciDAC2, EM simulations continue to play an important role in the 'Community Petascale Project for Accelerator Science and Simulation' (ComPASS), through close collaborations with SciDAC CETs/Institutes in computational science. Existing codes will be improved and new multi-physics tools will be developed to model large accelerator systems with unprecedented realism and high accuracy using computing resources at petascale. These tools aim at targeting the most challenging problems facing the ComPASS project. Supported by advances in computational science research, they have been successfully applied to the International Linear Collider (ILC) and the Large Hadron Collider (LHC) in High Energy Physics (HEP), the JLab 12-GeV Upgrade in Nuclear Physics (NP), as well as the Spallation Neutron Source (SNS) and the Linac Coherent Light Source (LCLS) in Basic Energy Sciences (BES)

  18. Design and optimization of large accelerator systems through high-fidelity electromagnetic simulations

    International Nuclear Information System (INIS)

    Ng, C; Akcelik, V; Candel, A; Chen, S; Ge, L; Kabel, A; Lee, Lie-Quan; Li, Z; Prudencio, E; Schussman, G; Uplenchwar, R; Xiao, L; Ko, K; Austin, T; Cary, J R; Ovtchinnikov, S; Smith, D N; Werner, G R; Bellantoni, L

    2008-01-01

    SciDAC-1, with its support for the 'Advanced Computing for 21st Century Accelerator Science and Technology' project, witnessed dramatic advances in electromagnetic (EM) simulations for the design and optimization of important accelerators across the Office of Science. In SciDAC2, EM simulations continue to play an important role in the 'Community Petascale Project for Accelerator Science and Simulation' (ComPASS), through close collaborations with SciDAC Centers and Insitutes in computational science. Existing codes will be improved and new multi-physics tools will be developed to model large accelerator systems with unprecedented realism and high accuracy using computing resources at petascale. These tools aim at targeting the most challenging problems facing the ComPASS project. Supported by advances in computational science research, they have been successfully applied to the International Linear Collider and the Large Hadron Collider in high energy physics, the JLab 12-GeV Upgrade in nuclear physics, and the Spallation Neutron Source and the Linac Coherent Light Source in basic energy sciences

  19. Observation of wakefields in a beam-driven photonic band gap accelerating structure

    Directory of Open Access Journals (Sweden)

    C. Jing

    2009-12-01

    Full Text Available Wakefield excitation has been experimentally studied in a three-cell X-band standing wave photonic band gap (PBG accelerating structure. Major monopole (TM_{01}- and TM_{02}-like and dipole (TM_{11}- and TM_{12}-like modes were identified and characterized by precisely controlling the position of beam injection. The quality factor Q of the dipole modes was measured to be ∼10  times smaller than that of the accelerating mode. A charge sweep, up to 80 nC, has been performed, equivalent to ∼30  MV/m accelerating field on axis. A variable delay low charge witness bunch following a high charge drive bunch was used to calibrate the gradient in the PBG structure by measuring its maximum energy gain and loss. Experimental results agree well with numerical simulations.

  20. Analysis and design of SSC underground structures

    International Nuclear Information System (INIS)

    Clark, G.T.

    1993-01-01

    This paper describes the analysis and design of underground structures for the Superconducting Super Collider (SSC) Project. A brief overview of the SSC Project and the types of underground structures are presented. Engineering properties and non-linear behavior of the geologic materials are reviewed. The three-dimensional sequential finite element rock-structure interaction analysis techniques developed by the author are presented and discussed. Several examples of how the method works, specific advantages, and constraints are presented. Finally, the structural designs that resulted from the sequential interaction analysis are presented

  1. Design of the hydraulic shock absorbers characteristics using the acceleration of the sprung mass

    Directory of Open Access Journals (Sweden)

    Polach P.

    2007-10-01

    Full Text Available The force-velocity characteristics of the air-pressure-controlled shock absorbers produced in BRANO a.s. were designed on the basis of the relative deflections of the air springs. These characteristics are verified by means of another approach – the acceleration of the sprung mass criterion. The reference vehicle is the same as in the previous case – the SOR C 12 intercity bus. The bus multibody models created in the alaska simulation tool are used for the designed characteristics verification. The results of both approaches are compared.

  2. Design of undercuts and dipole stabilizer rods for the CPHS RFQ accelerator

    Science.gov (United States)

    Cai, Jin-Chi; Xing, Qing-Zi; Guan, Xia-Ling; Du, Lei

    2012-05-01

    As part of the design and machining of the RFQ accelerator in the Compact Pulsed Hadron Source (CPHS) project at Tsinghua University, the design process of the undercuts and dipole stabilizer rods is presented in this paper. In particular, the relationship between the inter-vane voltage slope and the local frequency of the undercut section is described quantitatively. With the identification of modes existing in the cavity, the specific parameters are optimized by the SUPERFISH and MAFIA codes. In addition, the water-cooling requirement of the dipole stabilizer rods is briefly discussed.

  3. Accelerated safety analyses - structural analyses Phase I - structural sensitivity evaluation of single- and double-shell waste storage tanks

    International Nuclear Information System (INIS)

    Becker, D.L.

    1994-11-01

    Accelerated Safety Analyses - Phase I (ASA-Phase I) have been conducted to assess the appropriateness of existing tank farm operational controls and/or limits as now stipulated in the Operational Safety Requirements (OSRs) and Operating Specification Documents, and to establish a technical basis for the waste tank operating safety envelope. Structural sensitivity analyses were performed to assess the response of the different waste tank configurations to variations in loading conditions, uncertainties in loading parameters, and uncertainties in material characteristics. Extensive documentation of the sensitivity analyses conducted and results obtained are provided in the detailed ASA-Phase I report, Structural Sensitivity Evaluation of Single- and Double-Shell Waste Tanks for Accelerated Safety Analysis - Phase I. This document provides a summary of the accelerated safety analyses sensitivity evaluations and the resulting findings

  4. Structural design parameters of current WSDOT mixtures.

    Science.gov (United States)

    2013-06-01

    The AASHTO LRFD, as well as other design manuals, has specifications that estimate the structural performance of a concrete mixture with regard to compressive strength, tensile strength, and deformation-related properties such as the modulus of elast...

  5. Structural Analysis and Design of PCC Shoulders

    Science.gov (United States)

    1982-04-01

    A structural evaluation of PCC highway shoulders has been conducted and a comprehensive design procedure for plain jointed concrete shoulders developed. The procedure can be used to provide PCC shoulders either for rehabilitation of existing pavement...

  6. Designing visual appearance using a structured surface

    DEFF Research Database (Denmark)

    Johansen, Villads Egede; Thamdrup, Lasse Højlund; Smitrup, Christian

    2015-01-01

    followed by numerical and experimental verification. The approach comprises verifying all design and fabrication steps required to produce a desired appearance. We expect that the procedure in the future will yield structurally colored surfaces with appealing prescribed visual appearances....

  7. Proposal for a study of laser acceleration of electrons using micrograting structures at ATF (Phase 1)

    International Nuclear Information System (INIS)

    Chen, W.; Claus, J.; Fernow, R.C.

    1989-01-01

    We propose to investigate new methods of particle acceleration using a short-pulse CO 2 laser as the power source and grating-like structures as accelerator ''cavities''. Phase I of this program is intended to demonstrate the principle of the method. We will focus the laser light to a 3 mm line on the surface of the microstructure. The structure is used to transform the electric field pattern of the incoming transversely polarized laser beam to a mode which has a component along the electron beam direction in the vicinity of the surface. With 6 mJ of laser energy and a 6 ps pulse length, the electric field in the spot will be around 1 GV/m. The electron beam from the Brookhaven Accelerator Test Facility (ATF) will be focused transversely within the few micron transverse dimension of the microstructure. The maximum expected acceleration for a 1 GV/m field and a 3 mm acceleration length is 3 MeV. 17 refs., 11 figs., 2 tabs

  8. Computation of the H-wave accelerating structure of ion linacs

    International Nuclear Information System (INIS)

    Barsukov, A.B.; Dajkovskij, A.D.; Igoshin, V.B.; Portugalov, Yu.I.; Ryabov, A.D.

    1982-01-01

    The paper describes the method of engeneering computatjon of H-wave acceleratipg strUctures, used for low energy heavy particle accelerators. For this aim the computer code SUPERFISH-1 has been used. The results of theoretical analysis for some cavitjes with longitudinal magnetic field are given as well as comparison between calculated and experimental resulst

  9. Optimum frequency and gradient for the CLIC main linac accelerating structure

    CERN Document Server

    Grudiev, A; Wuensch, Walter

    2006-01-01

    A novel procedure for the optimization of CLIC main linac parameters including operating frequency and the accelerating gradient is presented. The optimization procedure takes into account both beam dynamics and high power rf constraints. Beam dynamics constraints are given by emittance growth due to short- and long-range transverse wakefields. RF constraints are given by rf breakdown and pulsed surface heating limitations of the accelerating structure. Interpolation of beam and structure parameters in a wide range allows hundreds of millions of accelerating structures to be analyzed to find the structure with the highest ratio of luminosity to main linac input power, which is used as the figure of merit. The frequency and gradient have been varied in the ranges 12-30 GHz and 90-150 MV/m respectively. It is shown that the optimum frequency lies in the range from 16 to 20 GHz depending on the accelerating gradient and that the optimum gradient is below 100 MV/m. Based on our current understanding of the constr...

  10. Structural Design Strategies for Improved Small Overlap Crashworthiness Performance.

    Science.gov (United States)

    Mueller, Becky C; Brethwaite, Andrew S; Zuby, David S; Nolan, Joseph M

    2014-11-01

    In 2012, the Insurance Institute for Highway Safety (IIHS) began a 64 km/h small overlap frontal crash test consumer information test program. Thirteen automakers already have redesigned models to improve test performance. One or more distinct strategies are evident in these redesigns: reinforcement of the occupant compartment, use of energy-absorbing fender structures, and the addition of engagement structures to induce vehicle lateral translation. Each strategy influences vehicle kinematics, posing additional challenges for the restraint systems. The objective of this two-part study was to examine how vehicles were modified to improve small overlap test performance and then to examine how these modifications affect dummy response and restraint system performance. Among eight models tested before and after design changes, occupant compartment intrusion reductions ranged from 6 cm to 45 cm, with the highest reductions observed in models with the largest number of modifications. All redesigns included additional occupant compartment reinforcement, one-third added structures to engage the barrier, and two modified a shotgun load path. Designs with engagement structures produced greater glance-off from the barrier and exhibited lower delta Vs but experienced more lateral outboard motion of the dummy. Designs with heavy reinforcement of the occupant compartment had higher vehicle accelerations and delta V. In three cases, these apparent trade-offs were not well addressed by concurrent changes in restraint systems and resulted in increased injury risk compared with the original tests. Among the 36 models tested after design changes, the extent of design changes correlated to structural performance. Half of the vehicles with the lowest intrusion levels incorporated aspects of all three design strategies. Vehicle kinematics and dummy and restraint system characteristics were similar to those observed in the before/after pairs. Different combinations of structural

  11. Design of an Air-Core HTS quadruple triplet for a heavy ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhan; Wei, Shaoqing; Lee, Sang Jin [Uiduk University, Gyeongju (Korea, Republic of)

    2016-12-15

    In recent years, high-temperature superconductor (HTS) Quadruple Triplets are being developed for heavy ion accelerators, because the HTS magnets are suitable to withstand radiation and high heat loads in the hot cell of accelerators. Generally, an iron yoke, which costs a mass of material, was employed to enhance the magnetic field when a quadrupole magnet was designed. The type of the magnet is called iron-dominated magnet, because the total magnetic field was mainly induced by the iron. However, in the HTS superconductor iron-dominated magnets, the coil-induced field also can have a certain proportion. Therefore, the air-core HTS quadrupole magnets can be considered instead of the iron-core HTS quadrupole magnet to be employed to save the iron material. This study presents the design of an air-core HTS quadruple triplet which consists three by air-core HTS quadruple magnet and compare the design result with that of an iron-core HTS quadruple triplet. First, the characteristics of an air-core HTS quadrupole magnet were analyzed to select the magnet system for the magnetic field uniformity impairment. Then, the field uniformity was improved(< 0.1%) exactly using evolution strategy (ES) method for each iron-core HTS quadrupole magnet and the air-core HTS quadruple triplet was established. Finally, the designed air-core triplet was compared with the iron-core HTS quadruple triplet, and the results of beam trajectories were presented with both the HTS quadruple triplet systems to show that the air-core triplet can be employed instead of the iron-core HTS triplet. The design of the air-core quadruple triplet was suggested for a heavy ion accelerator.

  12. Accelerator-based conversion (ABC) of weapons plutonium: Plant layout study and related design issues

    Energy Technology Data Exchange (ETDEWEB)

    Cowell, B.S.; Fontana, M.H. [Oak Ridge National Lab., TN (United States); Krakowski, R.A.; Beard, C.A.; Buksa, J.J.; Davidson, J.W.; Sailor, W.C.; Williamson, M.A. [Los Alamos National Lab., NM (United States)

    1995-04-01

    In preparation for and in support of a detailed R and D Plan for the Accelerator-Based Conversion (ABC) of weapons plutonium, an ABC Plant Layout Study was conducted at the level of a pre-conceptual engineering design. The plant layout is based on an adaptation of the Molten-Salt Breeder Reactor (MSBR) detailed conceptual design that was completed in the early 1070s. Although the ABC Plant Layout Study included the Accelerator Equipment as an essential element, the engineering assessment focused primarily on the Target; Primary System (blanket and all systems containing plutonium-bearing fuel salt); the Heat-Removal System (secondary-coolant-salt and supercritical-steam systems); Chemical Processing; Operation and Maintenance; Containment and Safety; and Instrumentation and Control systems. Although constrained primarily to a reflection of an accelerator-driven (subcritical) variant of MSBR system, unique features and added flexibilities of the ABC suggest improved or alternative approaches to each of the above-listed subsystems; these, along with the key technical issues in need of resolution through a detailed R&D plan for ABC are described on the bases of the ``strawman`` or ``point-of-departure`` plant layout that resulted from this study.

  13. Structural modules in AP1000 plant design

    International Nuclear Information System (INIS)

    Prasad, N.; Tunon-Sanjur, L.

    2007-01-01

    Structural modules are extensively used in AP1000 plant design. The shop manufacturing of modules components improves the quality and reliability of plant structures. The application of modules has a positive impact on construction schedules, and results in substantial savings in the construction cost. This paper describes various types of structural modules used for AP1000 plant structures. CA structural wall modules are steel plate modules with concrete placed, on or within the module, after module installation. The layout and design of the largest CA wall modules, CA01 and CA20, is described in detail. General discussion of structural floor modules, such as the composite and finned floors, is also included. Steel form CB modules (liners) consist of plate reinforced with angle stiffeners and tee sections. The angles and the tee sections are on the concrete side of the plate. Design of CB20 has been included as an example of CB type modules. Design codes and structural concepts related to module designs are discussed. (authors)

  14. Calculation of electrodynamical characteristics and choice of accelerating structure for storage ring

    International Nuclear Information System (INIS)

    Karnaukhov, I.M.; Popkov, Yu.P.; Telegin, Yu.N.; Trushkin, N.A.; Dajkovskij, A.G.; Zakamskaya, L.T.; Ryabov, A.D.

    1989-01-01

    Comparative analysis of several types of accelerating structures at standing E 010 wave is conducted on the basis of numerical calculations performed with the use of the PRUD-0 and PRUD programs. Dispersion dependences of electromagnetic field distribution, quality and coupling impedance are calculated both for axially symmetric and axially asymmetric modes of oscillations in structures with 699.3 MHz operating frequency. It is shown that structure with a cell the form of which is optimized with respect to shunt resistance on the main mode possesses the numerical spurious impedance in higher modes. This is the main factor when choosing accelerating structure for storage ring with multi-bunch operation conditions. 12 refs.; 3 figs.; 3 tabs

  15. Design optimization of shape memory alloy structures

    NARCIS (Netherlands)

    Langelaar, M.

    2006-01-01

    This thesis explores the possibilities of design optimization techniques for designing shape memory alloy structures. Shape memory alloys are materials which, after deformation, can recover their initial shape when heated. This effect can be used for actuation. Emerging applications for shape memory

  16. Conceptual Design Tool for Concrete Shell Structures

    DEFF Research Database (Denmark)

    Holst, Malene Kirstine; Kirkegaard, Poul Henning

    2011-01-01

    This paper focuses on conceptual tools for concrete shell structures when working within the span of performance-based design and computational morphogenesis. The designer, referred to as the Architect-Engineer, works through several iterations parallel with aesthetic, functional and technical...

  17. Reliability-Based Design of Coastal Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.

    1997-01-01

    is a combination of material presented in the following references: Burcharth, H.F. (1992) Reliability evaluation of a structure at sea. Proceedings of the Short Course on Design and Reliability of Coastal Structures. Venice, Scuola di S. Giovanni Evangelista, 1992. 23rd International Conference on Coastal...

  18. Beam Dynamics Design Studies of a Superconducting Radioactive Ion Beam Post-accelerator

    CERN Document Server

    Fraser, MA; Pasini, M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently post- accelerated by the normal conducting REX linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of trans- verse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wa...

  19. Design, fabrication, and testing of the BNL radio frequency quadrupole accelerators

    International Nuclear Information System (INIS)

    Brown, H.; Clifford, T.; Giordano, S.; McKenzie-Wilson, R.; Warner, F.; Khiari, F.; Puglisi, M.

    1984-01-01

    The Brookhaven National Laboratory polarized H - injection program for the AGS utilizes a Radio Frequency Quadrupole Accelerator for acceleration between the polarized source and the Alvarez Linac. Although operation has commenced with a few μ amperes of H - beam, it is anticipated that future polarized H - sources will have a considerably improved output. The RFQ will operate at 201.25 MHz and will be capable of handling a beam current of 0.02 amperes with a duty cycle of 0.25%. The resulting low average power has allowed novel solutions to the problems of vane alignment, rf current contacts, and removal of heat from the vanes. The design philosophy, details of cavity fabrication, and vane machining will be discussed. Results of low and high power rf testing will be presented together with the initial results of operations in the polarized H - beam line. (orig.)

  20. Design, fabrication, and testing of the BNL radio frequency quadrupole accelerator

    International Nuclear Information System (INIS)

    Brown, H.; Clifford, T.; Giordano, S.; Khiari, F.; McKenzie-Wilson, R.; Puglisi, M.; Warner, P.

    1984-01-01

    The Brookhaven National Laboratory polarized H - injection program for the AGS utilizes a Radio Frequency Quadrupole Accelerator for acceleration between the polarized source and the Alvarez Linac. Although operation has commenced with a few μ amperes of H - beam, it is anticipated that future polarized H - sources will have a considerably improved output. The RFQ will operate at 201.25 MHz and will be capable of handling a beam current of 0.02 amperes with a duty cycle of 0.25%. The resulting low average power has allowed novel solutions to the problems of vane alignment, rf current contacts, and removal of heat from the vanes. The design philosophy, details of cavity fabrication, and vane machining will be discussed. Results of low and high power rf testing will be presented together with the initial results of operations in the polarized H - beam line

  1. Client Server design and implementation issues in the Accelerator Control System environment

    International Nuclear Information System (INIS)

    Sathe, S.; Hoff, L.; Clifford, T.

    1995-01-01

    In distributed system communication software design, the Client Server model has been widely used. This paper addresses the design and implementation issues of such a model, particularly when used in Accelerator Control Systems. in designing the Client Server model one needs to decide how the services will be defined for a server, what types of messages the server will respond to, which data formats will be used for the network transactions and how the server will be located by the client. Special consideration needs to be given to error handling both on the server and client side. Since the server usually is located on a machine other than the client, easy and informative server diagnostic capability is required. The higher level abstraction provided by the Client Server model simplifies the application writing, however fine control over network parameters is essential to improve the performance. Above mentioned design issues and implementation trade-offs are discussed in this paper

  2. Experimental design and analysis for accelerated degradation tests with Li-ion cells.

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, Daniel Harvey; Thomas, Edward Victor; Jungst, Rudolph George; Roth, Emanuel Peter

    2003-08-01

    This document describes a general protocol (involving both experimental and data analytic aspects) that is designed to be a roadmap for rapidly obtaining a useful assessment of the average lifetime (at some specified use conditions) that might be expected from cells of a particular design. The proposed experimental protocol involves a series of accelerated degradation experiments. Through the acquisition of degradation data over time specified by the experimental protocol, an unambiguous assessment of the effects of accelerating factors (e.g., temperature and state of charge) on various measures of the health of a cell (e.g., power fade and capacity fade) will result. In order to assess cell lifetime, it is necessary to develop a model that accurately predicts degradation over a range of the experimental factors. In general, it is difficult to specify an appropriate model form without some preliminary analysis of the data. Nevertheless, assuming that the aging phenomenon relates to a chemical reaction with simple first-order rate kinetics, a data analysis protocol is also provided to construct a useful model that relates performance degradation to the levels of the accelerating factors. This model can then be used to make an accurate assessment of the average cell lifetime. The proposed experimental and data analysis protocols are illustrated with a case study involving the effects of accelerated aging on the power output from Gen-2 cells. For this case study, inadequacies of the simple first-order kinetics model were observed. However, a more complex model allowing for the effects of two concurrent mechanisms provided an accurate representation of the experimental data.

  3. Structure of period-2 step-1 accelerator island in area preserving maps

    International Nuclear Information System (INIS)

    Hirose, K.; Ichikawa, Y.H.; Saito, S.

    1996-03-01

    Since the multi-periodic accelerator modes manifest their contribution even in the region of small stochastic parameters, analysis of such regular motion appears to be critical to explore the stochastic properties of the Hamiltonian system. Here, structure of period-2 step-1 accelerator mode is analyzed for the systems described by the Harper map and by the standard map. The stability criterions have been analyzed in detail in comparison with numerical analyses. The period-3 squeezing around the period-2 step-1 islands is identified in the standard map. (author)

  4. Some problems on rf breakdown in room temperature accelerator structure, a possible criterion

    International Nuclear Information System (INIS)

    Wang, J.W.

    1986-04-01

    The discussion is confined to high gradient, room-temperature accelerators which have clean well-finished cavity surfaces and good vacuum conditions. Breakdown-initiating mechanisms due to ''cold'' field electron emission occurring at isolated sites on broad-area cavity surfaces, where the field is enhanced, are described. The influences of an alternating field and transition time tunneling are taken into account. The thermal instability resulting in vacuum voltage breakdown is hypothesized to derive a new criterion for room-temperature accelerator structure. 18 refs., 5 figs

  5. 805 MHz Beta = 0.47 Elliptical Accelerating Structure R & D

    Energy Technology Data Exchange (ETDEWEB)

    S. Bricker; C. Compton; W. Hartung; M. Johnson; F. Marti; J. Popierlarski; R. C. York; et al

    2008-09-22

    A 6-cell 805 MHz superconducting cavity for acceleration in the velocity range of about 0.4 to 0.53 times the speed of light was designed. After single-cell prototyping, three 6-cell niobium cavities were fabricated. In vertical RF tests of the 6-cell cavities, the measured quality factors (Q{sub 0}) were between 7 {center_dot} 10{sup 9} and 1.4 {center_dot} 10{sup 10} at the design field (accelerating gradient of 8 to 10 MV/m). A rectangular cryomodule was designed to house 4 cavities per cryomodule. The 4-cavity cryomodule could be used for acceleration of ions in a linear accelerator, with focusing elements between the cryomodules. A prototype cryomodule was fabricated to test 2 cavities under realistic operating conditions. Two of the 6-cell cavities were equipped with helium tanks, tuners, and input coupler and installed into the cryomodule. The prototype cryomodule was used to verify alignment, electromagnetic performance, frequency tuning, cryogenic performance, low-level RF control, and control of microphonics.

  6. Design Tools and Workflows for Braided Structures

    DEFF Research Database (Denmark)

    Vestartas, Petras; Heinrich, Mary Katherine; Zwierzycki, Mateusz

    2017-01-01

    This paper presents design workflows for the representation, analysis and fabrication of braided structures. The workflows employ a braid pattern and simulation method which extends the state-of-the-art in the following ways: by supporting the braid design of both pre-determined target shapes...... and merits of our method, demonstrated though four example design and analysis workflows. The workflows frame specific aspects of enquiry for the ongoing research project flora robotica. These include modelling target geometries, automatically producing instructions for fabrication, conducting structural...

  7. Design and fabrication of a silicon-based MEMS acceleration switch working lower than 10 g

    Science.gov (United States)

    Hwang, Jeongki; Ryu, Daeho; Park, Chihyun; Jang, Seung-gyo; Lee, Chung-il; Kim, Yong-Kweon

    2017-06-01

    This paper reports a low-g MEMS acceleration switch with threshold acceleration below 10 g. The proposed switch is made of single-crystalline silicon for high thermal stability and stress-free structure. A vertical operation type is adopted to enable fine control of the contact surface during the fabrication process. The switch contains displacement-restricting structures in all directions for impact resistance and is packaged with anodic bonding process. The fabricated switches had an average proof mass, initial gap, and spring constant of 307.38 µg, 6.39 µm, and 3.29 N m-1, respectively. Height profile of the free-hanging proof mass was measured to show that the switch does not suffer from stress problems. In the electrostatic operation test, the contact resistance of the switch was varied with contact force and the minimum value was estimated to be 8.5 Ω. The response time of the switch was measured to be shorter than 1.2 ms. The fabricated switch operated more than 10 000 cycles without failure. For the thermal stability test, the switch was heated at 80 °C for 6 h and the switch operated successfully over 200 times. In the rotation-table experiment, the switch operated at 6.61 g and error analysis was carried out in the consideration of tangential force generated during the rotation-table experiment. From the experimental values, the tangential force was calculated as 2.375 µN and the resulting reduction in the initial switching gap was simulated as 0.32 µm. The reduced threshold acceleration thus was estimated to be 6.62 g, which agrees very well with the measured threshold acceleration value of 6.61 g.

  8. Designing Structured Hypertext and Structuring Access to Hypertext.

    Science.gov (United States)

    Jonassen, David H.

    1988-01-01

    Reviews conceptual bases for hypertext, relates them to hypertext design issues, and suggests research issues that need to be addressed. Topics discussed include cognitive psychology; schema theory and semantic networks; problems with hypertext; knowledge structures; software; inductive and deductive design methods; and expert systems. (12…

  9. Large coil program support structure conceptual design

    International Nuclear Information System (INIS)

    Litherland, P.S.

    1977-01-01

    The purpose of the Large Coil Program (LCP) is to perform tests on both pool boiling and force cooled superconducting toroidal field coils. The tests will attempt to approximate conditions anticipated in an ignition tokamak. The test requirements resulted in a coil support design which accommodates up to six (6) test coils and is mounted to a structure capable of resisting coil interactions. The steps leading to the present LCP coil support structure design, details on selected structural components, and the basic assembly sequence are discussed

  10. LAVENDER: A steady-state core analysis code for design studies of accelerator driven subcritical reactors

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shengcheng; Wu, Hongchun; Cao, Liangzhi; Zheng, Youqi, E-mail: yqzheng@mail.xjtu.edu.cn; Huang, Kai; He, Mingtao; Li, Xunzhao

    2014-10-15

    Highlights: • A new code system for design studies of accelerator driven subcritical reactors (ADSRs) is developed. • S{sub N} transport solver in triangular-z meshes, fine deletion analysis and multi-channel thermal-hydraulics analysis are coupled in the code. • Numerical results indicate that the code is reliable and efficient for design studies of ADSRs. - Abstract: Accelerator driven subcritical reactors (ADSRs) have been proposed and widely investigated for the transmutation of transuranics (TRUs). ADSRs have several special characteristics, such as the subcritical core driven by spallation neutrons, anisotropic neutron flux distribution and complex geometry etc. These bring up requirements for development or extension of analysis codes to perform design studies. A code system named LAVENDER has been developed in this paper. It couples the modules for spallation target simulation and subcritical core analysis. The neutron transport-depletion calculation scheme is used based on the homogenized cross section from assembly calculations. A three-dimensional S{sub N} nodal transport code based on triangular-z meshes is employed and a multi-channel thermal-hydraulics analysis model is integrated. In the depletion calculation, the evolution of isotopic composition in the core is evaluated using the transmutation trajectory analysis algorithm (TTA) and fine depletion chains. The new code is verified by several benchmarks and code-to-code comparisons. Numerical results indicate that LAVENDER is reliable and efficient to be applied for the steady-state analysis and reactor core design of ADSRs.

  11. Superconducting link bus design for the accelerator project for upgrade of LHC

    International Nuclear Information System (INIS)

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.

    2011-01-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  12. Obtaining the Wakefield Due to Cell-to-Cell Misalignments in a Linear Accelerator Structure

    OpenAIRE

    Bane, Karl L. F.; Li, Zenghai

    2001-01-01

    A linear accelerator structure, such as will be used in the linacs of the JLC/NLC collider, is composed of on the order of 100 cells. The cells are constructed as individual cups that are brazed together to form a structure. Fabrication error will result in slight cell-to-cell misalignments along the finished structure. In this report we derive an approximation to the transverse wakefield of a structure with cell-to-cell misalignments in terms of the eigenfunctions and eigenvalues of the erro...

  13. Preliminary design study of the TMT Telescope structure system: overview

    Science.gov (United States)

    Usuda, Tomonori; Ezaki, Yutaka; Kawaguchi, Noboru; Nagae, Kazuhiro; Kato, Atsushi; Takaki, Junji; Hirano, Masaki; Hattori, Tomoya; Tabata, Masaki; Horiuchi, Yasushi; Saruta, Yusuke; Sofuku, Satoru; Itoh, Noboru; Oshima, Takeharu; Takanezawa, Takashi; Endo, Makoto; Inatani, Junji; Iye, Masanori; Sadjadpour, Amir; Sirota, Mark; Roberts, Scott; Stepp, Larry

    2014-07-01

    We present an overview of the preliminary design of the Telescope Structure System (STR) of Thirty Meter Telescope (TMT). NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corporation (MELCO) to take over the preliminary design work. MELCO performed a comprehensive preliminary design study in 2012 and 2013 and the design successfully passed its Preliminary Design Review (PDR) in November 2013 and April 2014. Design optimizations were pursued to better meet the design requirements and improvements were made in the designs of many of the telescope subsystems as follows: 1. 6-legged Top End configuration to support secondary mirror (M2) in order to reduce deformation of the Top End and to keep the same 4% blockage of the full aperture as the previous STR design. 2. "Double Lower Tube" of the elevation (EL) structure to reduce the required stroke of the primary mirror (M1) actuators to compensate the primary mirror cell (M1 Cell) deformation caused during the EL angle change in accordance with the requirements. 3. M1 Segment Handling System (SHS) to be able to make removing and installing 10 Mirror Segment Assemblies per day safely and with ease over M1 area where access of personnel is extremely difficult. This requires semi-automatic sequence operation and a robotic Segment Lifting Fixture (SLF) designed based on the Compliance Control System, developed for controlling industrial robots, with a mechanism to enable precise control within the six degrees of freedom of position control. 4. CO2 snow cleaning system to clean M1 every few weeks that is similar to the mechanical system that has been used at Subaru Telescope. 5. Seismic isolation and restraint systems with respect to safety; the maximum acceleration allowed for M1, M2, tertiary mirror (M3), LGSF, and science instruments in 1,000 year return period earthquakes are defined in the requirements. The Seismic requirements apply to any EL angle, regardless of the

  14. Structural design of Kaohsiung Stadium, Taiwan

    Science.gov (United States)

    Watanabe, Hideyuki; Tanno, Yoshiro; Nakai, Masayoshi; Ohshima, Takashi; Suguichi, Akihiro; Lee, William H.; Wang, Jensen

    2013-01-01

    This paper presents an outline description of the structural design of the main stadium for the World Games held in Kaohsiung City, Taiwan, in 2009. Three new design concepts, unseen in previous stadiums, were proposed and realized: “an open stadium”, “an urban park”, and “a spiral continuous form”. Based on the open stadium concept, simple cantilever trusses in the roof structure were arranged in a delicate rhythm, and a so-called oscillating hoop of steel tubes was wound around the top and bottom surfaces of a group of cantilever trusses to form a continuous spiral form. Also, at the same time by clearly grouping the structural elements of the roof structure, the dramatic effect of the urban park was highlighted by unifying the landscape and the spectator seating area to form the stadium facade. This paper specifically reports on the overview of the building, concepts of structural design, structural analysis of the roof, roof design, foundation design, and an outline of the construction.

  15. H.V. support structure of 3MVDC generator and its protection from HV discharges in vacuum and SF6 gas for DC electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, D.K.; Rajan, R.N.; Srivastava, S.K.; Dewangan, S.; Jayaprakash, D.; Bakhtsingh, R.I.; Acharya, S.; Gantayet, L.M., E-mail: dksharma@barc.gov.in [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-07-01

    Accelerator and Pulse Power Division of BARC has developed a DC electron accelerator for cross linking of polymers, medical sterilisation, preservation of food. The demonstration of stack-gas cleanup for green power generation has been demonstrated successfully. The support structure of the 3MVDC voltage generator is made of Perspex for high dielectric strength, easy availability of raw material, excellent radiation resistance and long term dimensional stability. This paper describes the salient design features of the High voltage support structure in brief. (author)

  16. Optimum Frequency and Gradient for the CLIC main linac accelerating structure

    CERN Document Server

    Grudiev, A; Schulte, D; Wuensch, W

    2008-01-01

    Recently the CLIC study has changed the operating frequency and accelerating gradient of the main linac from 30 GHz and 150 MV/m to 12 GHz and 100 MV/m, respectively. This major change of parameters has been driven by the results from a novel main linac optimization procedure. The procedure allows the simultaneous optimization of operating frequency, accelerating gradient, and many other parameters of CLIC main linac. It takes into account both beam dynamics (BD) and high power RF constraints. BD constraints are related to ermittance growth due to short- and long-range transverse wakefields. RF constraints are related to RF breakdown and pulsed surface heating of the accelerating structure. The optimization figure of merit includes the power efficiency, measured as a ratio of luminosity to the input power, as well as a quantity proportional to total cost.

  17. Design Tools and Workflows for Braided Structures

    DEFF Research Database (Denmark)

    Vestartas, Petras; Heinrich, Mary Katherine; Zwierzycki, Mateusz

    2017-01-01

    This paper presents design workflows for the representation, analysis and fabrication of braided structures. The workflows employ a braid pattern and simulation method which extends the state-of-the-art in the following ways: by supporting the braid design of both pre-determined target shapes...... and exploratory, generative, or evolved designs; by incorporating material and fabrication constraints generalised for both hand and machine; by providing a greater degree of design agency and supporting real-time modification of braid topologies. The paper first introduces braid as a technique, stating...... and merits of our method, demonstrated though four example design and analysis workflows. The workflows frame specific aspects of enquiry for the ongoing research project flora robotica. These include modelling target geometries, automatically producing instructions for fabrication, conducting structural...

  18. Design for simultaneous acceleration of stable and unstable beams in a superconducting heavy-ion linear accelerator for RISP

    Science.gov (United States)

    Kim, Jongwon; Son, Hyock-Jun; Park, Young-Ho

    2017-11-01

    The post-accelerator of isotope separation on-line (ISOL) system for rare isotope science project (RISP) is a superconducting linear accelerator (SC-linac) with a DC equivalent voltage of around 160 MV. An isotope beam extracted from the ISOL is in a charge state of 1+ and its charge state is increased to n+ by charge breeding with an electron beam ion source (EBIS). The charge breeding takes tens of ms and the pulse width of extracted beam from the EBIS is tens of μs, which operates at up to 30 Hz. Consequently a large portion of radio frequency (rf) time of the post SC-linac is unused. The post-linac is equipped also with an electron cyclotron resonance (ECR) ion source for stable ion acceleration. Thanks to the large phase acceptance of SC-linac, it is possible to accelerate simultaneously both stable and radioisotope ions with a similar charge to mass ratio by sharing rf time. This operation scheme is implemented for RISP with the addition of an electric chopper and magnetic kickers. The facility will be capable of providing the users of the ISOL and in-flight fragmentation (IF) systems with different beams simultaneously, which would help nuclear science users in obtaining a beam time as high-precision measurements often need long hours.

  19. Vibration Antiresonance Design for a Spacecraft Multifunctional Structure

    Directory of Open Access Journals (Sweden)

    Dong-Xu Li

    2017-01-01

    Full Text Available Spacecraft must withstand rigorous mechanical environment experiences such as acceleration, noise, vibration, and shock during the process of launching, satellite-vehicle separation, and so on. In this paper, a new spacecraft multifunctional structure concept designed by us is introduced. The multifunctional structure has the functions of not only load bearing, but also vibration reduction, energy source, thermal control, and so on, and we adopt a series of viscoelastic parts as connections between substructures. Especially in this paper, a vibration antiresonance design method is proposed to realize the vibration reduction. The complex zero-point equations of the vibration system are firstly established, and then the vibration antiresonance design for the system is achieved. For solving the difficulties due to viscoelastic characteristics of the connecting parts, we present the determining formulas to obtain the structural parameters, so that the complex zero-point equations can be satisfied. Numerical simulation and ground experiment demonstrate the correctness and effectiveness of the proposed method. This method can solve the structural vibration control problem under the function constraints of load bearing and energy supplying and will expand the performance of spacecraft functional modules.

  20. Diamond field emitter array cathodes and possibilities for employing additive manufacturing for dielectric laser accelerating structures

    Energy Technology Data Exchange (ETDEWEB)

    Simakov, Evgenya Ivanovna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Andrews, Heather Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Herman, Matthew Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hubbard, Kevin Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weis, Eric [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-20

    These are slides for a presentation at Stanford University. The outline is as follows: Motivation: customers for compact accelerators, LANL's technologies for laser acceleration, DFEA cathodes, and additive manufacturing of micron-size structures. Among the stated conclusions are the following: preliminary study identified DFEA cathodes as promising sources for DLAs--high beam current and small emittance; additive manufacturing with Nanoscribe Professional GT can produce structures with the right scale features for a DLA operating at micron wavelengths (fabrication tolerances need to be studied, DLAs require new materials). Future plans include DLA experiment with a beam produced by the DFEA cathode with field emission, demonstration of photoemission from DFEAs, and new structures to print and test.

  1. Protein structure--based drug design.

    Science.gov (United States)

    Whittle, P J; Blundell, T L

    1994-01-01

    Design cycles will undoubtedly play an increasingly important role in drug discovery in the coming years, as the amount of structural information on protein targets continues to rise. However, the traditional method of drug discovery, based upon random screening and systematic modification of leads by medicinal chemistry techniques, will probably not be abandoned completely because it has a potentially important advantage over more structure-based methods--namely, leads identified in this way are unlikely to show a close resemblance to the natural ligand or substrate. They may, therefore, have advantages in terms of patent novelty, selectivity, or pharmacokinetic profile. However, such leads could then serve as the basis for structure-based, rational modification programs, in which their interactions with target receptors are defined (as we have described) and improved molecules are designed. A final important point to be made about structure-based design in drug discovery is that, while it can be of great use in the initial process of identifying ligands with improved affinity and selectivity in vitro, it can usually say very little about other essential aspects of the drug discovery process, e.g. the need to achieve an adequate pharmacokinetic profile and low toxicity in vivo. This observation reminds us that drug design is a multidisciplinary process, involving molecular biologists, biochemists, pharmacologists, organic chemists, crystallographers, and others. In order to be effective, therefore, structure-based design must be properly integrated into the overall discovery effort.

  2. Development and testing of a superconducting acceleration resonator using new methods in design and fabrication

    International Nuclear Information System (INIS)

    Steck, M.

    1986-01-01

    A superconducting quarter-wave resonator at 325 MHz was studied for the implementation at the Heidelberg post-accelerator. Using the computer programs SUPERFISH and URMEL the first design derived from analytical approaches was optimized regarding the superconducting operation. The measurements on the model showed good agreement with the calculations. By modification of the standard techniques the fabrication of the resonator body and the preparation of the superconducting surface could be simplified. On the superconducting resonator 1 μm thick superconducting surfaces of pure lead as well as a lead/tin alloy were tested. Thereby with lead a quality of the resonator Q 0 =8.5.10 7 and a maximal electrical acceleration field in the continuous region of epsilonsub(acc)=2.16 MV/m at Q=1.10 7 were reached. The measurements with a surface of lead/tin yielded Q 0 =1.4.10 8 and as maximal acceleration field epsilonsub(acc)=1.93 MV/m at Q=1.10 7 . A further increasing of the maximal electric field by conditioning of the resonator can be expected because of the test results. The excellent mechanical stability not reachable with other resonator types which manifests by a static frequency shift of 4 Hz/(MV/m) 2 and rapid frequency oscillations [de

  3. Solving Large Scale Nonlinear Eigenvalue Problem in Next-Generation Accelerator Design

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Ben-Shan; Bai, Zhaojun; /UC, Davis; Lee, Lie-Quan; Ko, Kwok; /SLAC

    2006-09-28

    A number of numerical methods, including inverse iteration, method of successive linear problem and nonlinear Arnoldi algorithm, are studied in this paper to solve a large scale nonlinear eigenvalue problem arising from finite element analysis of resonant frequencies and external Q{sub e} values of a waveguide loaded cavity in the next-generation accelerator design. They present a nonlinear Rayleigh-Ritz iterative projection algorithm, NRRIT in short and demonstrate that it is the most promising approach for a model scale cavity design. The NRRIT algorithm is an extension of the nonlinear Arnoldi algorithm due to Voss. Computational challenges of solving such a nonlinear eigenvalue problem for a full scale cavity design are outlined.

  4. Design of inductively detuned RF extraction cavities for the Relativistic Klystron Two Beam Accelerator

    International Nuclear Information System (INIS)

    Henestroza, E.; Yu, S.S.; Li, H.

    1995-04-01

    An inductively detuned traveling wave cavity for the Relativistic Klystron Two Beam Accelerator expected to extract high RF power at 11. 424 GHz for the 1 TeV Center of Mass Next Linear Collider has been designed. Longitudinal beam dynamics studies led to the following requirements on cavity design: (a) Extraction of 360 MW of RF power with RF component of the current being 1.15 kAmps at 11.424 GHz, (b) Inductively detuned traveling wave cavity with wave phase velocity equal to 4/3 the speed of light, (c) Output cavity with appropriate Q ext and eigenfrequency for proper matching. Furthermore, transverse beam dynamics require low shunt impedances to avoid the beam break-up instability. We describe the design effort to meet these criteria based on frequency-domain and time-domain computations using 2D- and 3D- electromagnetic codes

  5. Analytical and Numerical Calculations of Two-Dimensional Dielectric Photonic Band Gap Structures and Cavities for Laser Acceleration

    CERN Document Server

    Samokhvalova, Ksenia R; Liang Qian, Bao

    2005-01-01

    Dielectric photonic band gap (PBG) structures have many promising applications in laser acceleration. For these applications, accurate determination of fundamental and high order band gaps is critical. We present the results of our recent work on analytical calculations of two-dimensional (2D) PBG structures in rectangular geometry. We compare the analytical results with computer simulation results from the MIT Photonic Band Gap Structure Simulator (PBGSS) code, and discuss the convergence of the computer simulation results to the analytical results. Using the accurate analytical results, we design a mode-selective 2D dielectric cylindrical PBG cavity with the first global band gap in the frequency range of 8.8812 THz to 9.2654 THz. In this frequency range, the TM01-like mode is shown to be well confined.

  6. Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Kafka, Gene [Illinois Inst. of Technology, Chicago, IL (United States)

    2015-05-01

    The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with signi cant exibility in mind, but without compromising cost e ciency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of di erent variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state of the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of- ight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.

  7. Laser Wakefield Acceleration: Structural and Dynamic Studies. Final Technical Report ER40954

    Energy Technology Data Exchange (ETDEWEB)

    Downer, Michael C. [Univ. of Texas at Austin, TX (United States)

    2014-04-30

    Particle accelerators enable scientists to study the fundamental structure of the universe, but have become the largest and most expensive of scientific instruments. In this project, we advanced the science and technology of laser-plasma accelerators, which are thousands of times smaller and less expensive than their conventional counterparts. In a laser-plasma accelerator, a powerful laser pulse exerts light pressure on an ionized gas, or plasma, thereby driving an electron density wave, which resembles the wake behind a boat. Electrostatic fields within this plasma wake reach tens of billions of volts per meter, fields far stronger than ordinary non-plasma matter (such as the matter that a conventional accelerator is made of) can withstand. Under the right conditions, stray electrons from the surrounding plasma become trapped within these “wake-fields”, surf them, and acquire energy much faster than is possible in a conventional accelerator. Laser-plasma accelerators thus might herald a new generation of compact, low-cost accelerators for future particle physics, x-ray and medical research. In this project, we made two major advances in the science of laser-plasma accelerators. The first of these was to accelerate electrons beyond 1 gigaelectronvolt (1 GeV) for the first time. In experimental results reported in Nature Communications in 2013, about 1 billion electrons were captured from a tenuous plasma (about 1/100 of atmosphere density) and accelerated to 2 GeV within about one inch, while maintaining less than 5% energy spread, and spreading out less than ½ milliradian (i.e. ½ millimeter per meter of travel). Low energy spread and high beam collimation are important for applications of accelerators as coherent x-ray sources or particle colliders. This advance was made possible by exploiting unique properties of the Texas Petawatt Laser, a powerful laser at the University of Texas at Austin that produces pulses of 150 femtoseconds (1 femtosecond is 10

  8. A Combined Shielding Design for a Neutron Generator and a Linear Accelerator at Soreq NRC

    International Nuclear Information System (INIS)

    Epstein, L.

    2014-01-01

    A new radiography facility is designed at Soreq NRC. The facility will hold a neutron generator that produces 1.73·109 n/s with an energy of 14 MeV and a linear accelerator that accelerates electrons to an energy of 9 MeV. The two radiation sources will be installed in 2 separate laboratories that will be built in an existing building. Each laboratory will have its own machine and control room. The dose rates around the sources were calculated using the FLUKA Monte Carlo code(1,2). The annual doses were calculated in several regions around the generator and the accelerator laboratories in accordance with the occupancy in each area. The calculated annual doses were compared with the dose limits specified in the Safety at Work Regulations(3) and the IAEC Standard for Protection against Ionizing Radiation. The shielding was designed to comply with the following dose constraints: 0.3 mSv/y for members of the public and 2 mSv/y for radiation workers. Each radiation source is planned to produce radiation for a maximum of 500 hours per year. The dose rate in the direct beam of the accelerator is 30 Gy/min at 1 m from the source and it will be surrounded by a collimator with an opening of 30N-tilde horizontally and 2 mm vertically, 3 m from the radiation source. The leakage radiation dose will not be greater than 1.5 mGy/min (0.005% of the direct beam, according to the manufacturer). The leakage radiation will be produced isotropically. The neutron generator will be surrounded by a shielding made of a 10 cm iron cylinder (density 7.87 g/cm3), surrounded by 50 cm of borated polyethylene (atomic percent: H (13.8%), C (82.2%), B (4%), density: 0.92 g/cm3) and 5 cm of lead (density 11.35 g/cm3). The neutron generator shielding was not designed or required in the present shielding design but was considered in the shielding calculations

  9. Design of a beam shaping assembly for an accelerator-based BNCT system

    International Nuclear Information System (INIS)

    Stichelbaut, F.; Forton, E.; Jongen, Y.

    2006-01-01

    A complete BNCT system based on a high-intensity proton accelerator is developed by the IBA company. The neutron beam is produced via the 7 Li(p,n) 7 Be reaction using a solid lithium target. The neutron energy spectrum is tailored with a beam shaping assembly surrounding the target. This device is the object of an extensive R and D project and is fully designed with the Monte Carlo simulation code MCNPX. The emphasis is put on the treatment quality, notably the radiation dose at the skin level, and the achievable neutron flux. (author)

  10. Accelerated approval and breakthrough therapy designation: oncology drug development on speed?

    Science.gov (United States)

    Yao, James C; Meric-Bernstam, Funda; Lee, J Jack; Eckhardt, S Gail

    2013-08-15

    Recent advances in biotechnology have led to discoveries resulting in major improvements in the therapy of refractory malignancies, although most advanced cancers remain incurable. Thus, there is global consensus around the need to streamline the drug approval process for effective agents. Accelerated Approval and Breakthrough Therapy Designation hold the promise of making new treatments available sooner through the use of smaller studies using intermediate endpoints. Here, we consider the inherent limitations of smaller studies and discuss the strategies for hastening oncology drug development while maintaining high-efficacy standards. ©2013 AACR.

  11. The design of 28 GHz ECR Ion Source for the Compact Linear Accelerator in Korea

    International Nuclear Information System (INIS)

    MiSook, Won; ByoungSeob, Lee; JinYong, Park; DongJun Park; JongPil, Kim; JongSeong, Bae; JungKeum, Ahn; SonJong, Wang; Nakagawa, T.

    2012-01-01

    The construction of a compact linear accelerator is in progress by Korea Basic Science Institute. The main capability of this facility is the production of multiply ionized metal clusters and the generation more intense beams of highly charged ions for material, medical and nuclear physical research. To produce the intense beam of highly charged ions, we will construct an Electron Cyclotron Resonance Ion Source (ECRIS) using 28 GHz microwaves. For this ECRIS, the design of a superconducting magnet, microwave inlet, beam extraction and plasma chamber was completed. Also we are constructing a superconducting magnet system. In this poster, we will report the current status of development of our 28 GHz ECRIS. (authors)

  12. Low-beam-loss design of a compact, high-current deuteron radio frequency quadrupole accelerator

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2004-10-01

    Full Text Available A 201.5 MHz, 50 mA, 2.0 MeV deuteron radio frequency quadrupole accelerator is proposed as the neutron generator for the neutron experiment facility project at Peking University, China. Based on better understanding of beam losses, some new optimization procedures concerning both longitudinal and transverse dynamics are adopted. Accordingly, the beam transmission efficiency is improved from 91.2% to 98.3% and the electrode length is shortened from 2.91 to 2.71 m. The fundamental physical analyses are performed to look inside the new design recipe and explain why it works.

  13. Design for low beam loss in accelerators for intense neutron source applications

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1993-01-01

    Control of beam loss in intense ion linacs involves keeping beam spill below parts in 10 -5 --10 -8 /m by preventing total beam size from extending to the limiting apertures. Starting from good rms design practices, new analysis of the machine architecture is described in terms of the effects of the machine tune with space-charge, free-energy constraint, and halo-producing mechanisms. It is shown that halos are produced by the time- (or position-) varying nature of common linac aspects (such as misalignment, mismatching, acceleration, and construction techniques) through collective core/single-particle interaction dynamics plus resonances

  14. Design study of low energy beam transport line for ion beams of the post-accelerator at RAON

    Science.gov (United States)

    Lee, Yumi; Kim, Eun-San

    2015-07-01

    Low-energy ions produced by the ion source pass through the focusing and acceleration sections. During this process, the ions accumulate energy and are finally transported to the apparatus that utilizes them for a specific purpose. Thus, in order to increase the transmission efficiency of the ion beams, the low energy beam transport (LEBT) system must minimize the beam loss and the emittance growth. The LEBT system is designed and optimized to transmit 132Sn16+ and 58Ni8+ beams of the post-accelerator at RAON that is the accelerator complex for the rare isotope science. The post-accelerator LEBT line comprises solenoids and electrostatic quadrupoles for transverse focusing and a multi-harmonic buncher for longitudinal focusing. This paper presents the results of the optical design and beam tracking for the post-accelerator LEBT obtained by using TraceWIN and TRACK codes.

  15. Structural analysis at aircraft conceptual design stage

    Science.gov (United States)

    Mansouri, Reza

    In the past 50 years, computers have helped by augmenting human efforts with tremendous pace. The aircraft industry is not an exception. Aircraft industry is more than ever dependent on computing because of a high level of complexity and the increasing need for excellence to survive a highly competitive marketplace. Designers choose computers to perform almost every analysis task. But while doing so, existing effective, accurate and easy to use classical analytical methods are often forgotten, which can be very useful especially in the early phases of the aircraft design where concept generation and evaluation demands physical visibility of design parameters to make decisions [39, 2004]. Structural analysis methods have been used by human beings since the very early civilization. Centuries before computers were invented; the pyramids were designed and constructed by Egyptians around 2000 B.C, the Parthenon was built by the Greeks, around 240 B.C, Dujiangyan was built by the Chinese. Persepolis, Hagia Sophia, Taj Mahal, Eiffel tower are only few more examples of historical buildings, bridges and monuments that were constructed before we had any advancement made in computer aided engineering. Aircraft industry is no exception either. In the first half of the 20th century, engineers used classical method and designed civil transport aircraft such as Ford Tri Motor (1926), Lockheed Vega (1927), Lockheed 9 Orion (1931), Douglas DC-3 (1935), Douglas DC-4/C-54 Skymaster (1938), Boeing 307 (1938) and Boeing 314 Clipper (1939) and managed to become airborne without difficulty. Evidencing, while advanced numerical methods such as the finite element analysis is one of the most effective structural analysis methods; classical structural analysis methods can also be as useful especially during the early phase of a fixed wing aircraft design where major decisions are made and concept generation and evaluation demands physical visibility of design parameters to make decisions

  16. Structural Design Optimization On Thermally Induced Vibration

    International Nuclear Information System (INIS)

    Gu, Yuanxian; Chen, Biaosong; Zhang, Hongwu; Zhao, Guozhong

    2002-01-01

    The numerical method of design optimization for structural thermally induced vibration is originally studied in this paper and implemented in application software JIFEX. The direct and adjoint methods of sensitivity analysis for thermal induced vibration coupled with both linear and nonlinear transient heat conduction is firstly proposed. Based on the finite element method, the structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat conduction. In the thermal analysis model, the nonlinear heat conduction considered is result from the radiation and temperature-dependent materials. The sensitivity analysis of transient linear and nonlinear heat conduction is performed with the precise time integration method. And then, the sensitivity analysis of structural transient dynamics is performed by the Newmark method. Both the direct method and the adjoint method are employed to derive the sensitivity equations of thermal vibration, and there are two adjoint vectors of structure and heat conduction respectively. The coupling effect of heat conduction on thermal vibration in the sensitivity analysis is particularly investigated. With coupling sensitivity analysis, the optimization model is constructed and solved by the sequential linear programming or sequential quadratic programming algorithm. The methods proposed have been implemented in the application software JIFEX of structural design optimization, and numerical examples are given to illustrate the methods and usage of structural design optimization on thermally induced vibration

  17. The sense of balance in humans: Structural features of otoconia and their response to linear acceleration.

    Directory of Open Access Journals (Sweden)

    Rüdiger Kniep

    Full Text Available We explored the functional role of individual otoconia within the otolith system of mammalians responsible for the detection of linear accelerations and head tilts in relation to the gravity vector. Details of the inner structure and the shape of intact human and artificial otoconia were studied using environmental scanning electron microscopy (ESEM, including decalcification by ethylenediaminetetraacetic acid (EDTA to discriminate local calcium carbonate density. Considerable differences between the rhombohedral faces of human and artificial otoconia already indicate that the inner architecture of otoconia is not consistent with the point group -3m. This is clearly confirmed by decalcified otoconia specimen which are characterized by a non-centrosymmetric volume distribution of the compact 3+3 branches. This structural evidence for asymmetric mass distribution was further supported by light microscopy in combination with a high speed camera showing the movement of single otoconia specimen (artificial specimen under gravitational influence within a viscous medium (artificial endolymph. Moreover, the response of otoconia to linear acceleration forces was investigated by particle dynamics simulations. Both, time-resolved microscopy and computer simulations of otoconia acceleration show that the dislocation of otoconia include significant rotational movement stemming from density asymmetry. Based on these findings, we suggest an otolith membrane expansion/stiffening mechanism for enhanced response to linear acceleration transmitted to the vestibular hair cells.

  18. Quasi-static drift-tube accelerating structures for low-speed heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Faltens, A.; Keefe, D.

    1977-11-03

    The major attractions of the pulsed drift-tubes are that they are non-resonant structures and that they appear suitable for accelerating a very high current bunch at low energies. The mechanical tolerances of the non-resonant structure are very loose and the cost per meter should be low; the cost of the transport system is expected to be the major cost. The pulse power modulators used to drive the drift-tubes are inexpensive compared to r.f. sources with equivalent peak-power. The longitudinal emittance of the beam emerging from the structure could be extremely low.

  19. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure

    Directory of Open Access Journals (Sweden)

    Brian J. Munroe

    2016-03-01

    Full Text Available We report the design, fabrication, and high gradient testing of a 17.1 GHz photonic band-gap (PBG accelerator structure. Photonic band-gap (PBG structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox input and output cells, with input power of up to 4 MW from a klystron supplied via a TM_{01} mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87  MV/m at a breakdown probability of 1.19×10^{-1} per pulse per meter. The PBG structure was tested with 100 ns pulses at gradient levels of less than 90  MV/m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89  MV/m at a breakdown probability of 1.09×10^{-1} per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.

  20. Design methods of rhombic tensegrity structures

    Science.gov (United States)

    Feng, Xi-Qiao; Li, Yue; Cao, Yan-Ping; Yu, Shou-Wen; Gu, Yuan-Tong

    2010-08-01

    As a special type of novel flexible structures, tensegrity holds promise for many potential applications in such fields as materials science, biomechanics, civil and aerospace engineering. Rhombic systems are an important class of tensegrity structures, in which each bar constitutes the longest diagonal of a rhombus of four strings. In this paper, we address the design methods of rhombic structures based on the idea that many tensegrity structures can be constructed by assembling one-bar elementary cells. By analyzing the properties of rhombic cells, we first develop two novel schemes, namely, direct enumeration scheme and cell-substitution scheme. In addition, a facile and efficient method is presented to integrate several rhombic systems into a larger tensegrity structure. To illustrate the applications of these methods, some novel rhombic tensegrity structures are constructed.