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Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE

Date 6-9 May 1991

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Displaying Results 1 - 25 of 1072
  • Conference Record of the IEEE Particle Accelerator Conference. Accelerator Science and Technology (Cat. No.91CH3038-7)

    Publication Year: 1991
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    Freely Available from IEEE
  • Physics and technology challenges of BB factories

    Publication Year: 1991 , Page(s): 1 - 5 vol.1
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    The design of a high-luminosity asymmetric B factory leads to physics challenges primarily in the areas of lattice design and the beam-beam interaction. In the first area, the issues are related to the production of low beta /sub v/* values, the separation of the two beams, and the design of the masking system. In the second area, the physics issues are centered around the techniques for optimizing the luminosity for the new parameter regime of asymmetric collisions. Coverage is given to lattice design beam-beam interaction, the RF system and the feedback system.<> View full abstract»

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  • Charged particle accelerators for inertial fusion energy

    Publication Year: 1991 , Page(s): 6 - 10 vol.1
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    A review is presented of the rationale for accelerators as inertial fusion drivers, emphasizing that these devices provide a viable path to fusion energy from viewpoints of both physics and engineering.<> View full abstract»

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  • Physics and technology challenges of ultra low emittance synchrotron light sources

    Publication Year: 1991 , Page(s): 11 - 15 vol.1
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    The opportunities and challenges presented by the development of ever-higher brightness synchrotron radiation sources are discussed. The use of greater brightness in imaging and orbit stability is discussed. High brightness is also examined for high temporal coherence.<> View full abstract»

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  • Superconducting accelerator cavities on a large scale

    Publication Year: 1991 , Page(s): 16 - 20 vol.1
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    Large-scale construction of superconducting accelerator cavities is now is progress at several laboratories around the world. KEK (Japan National Laboratory for High Energy Physics) completed 32 five-cell niobium 508-MHz cavities for TRISTAN in the autumn of 1989, and has an operating experience of many thousands hours with electron and positron beams. CEBAF (Continuous Electron Beam Accelerator Facility), CERN (Conseil European pour le Recherche Nucleaire), and DESY (Deutsches Electonica-Synchrotron) are also building superconducting cavities on a large scale, and they are supposed to start operation in the near future. Superconducting cavities are also being considered for use in the accelerators for a B-factory or linear colliders. These projects are described and some of the problems associated with large-scale cavity production are discussed.<> View full abstract»

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  • Microscopic examination of field emission areas in superconducting Nb cavities

    Publication Year: 1991 , Page(s): 21 - 23 vol.1
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    A superconducting cavity has been developed in which it is possible to expose a small region of the cavity, called the dimple, to very high surface RF electric fields. In a break-apart version of this cavity, the dimple is part of a demountable niobium end-plate which fits into the SEM/EDS system. Surface RF electric fields between 50 and 70 MV/m have been supported by the dimple in several tests. On subsequent SEM examination of the end-plates, many interesting features associated with emission were discovered. Each emission site is located at the center of a starburst shaped region of reduced secondary emission coefficient. At the center of these sites craters of molten niobium have often been found. Sometimes the sites contain features which look like nodules or ripples on the niobium surface.<> View full abstract»

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  • Issues confronting vacuum system design for e+e- storage rings

    Publication Year: 1991 , Page(s): 24 - 28 vol.1
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    The challenges that face vacuum system design for high-intensity synchrotron light sources and for high luminosity e/sup +/e/sup -/ colliders are explored. Many of these challenges are common to the two types of storage rings. Constraints on beam-gas-induced detector backgrounds produced in the interaction region (IR) influence not just the vacuum system but the optics and the geometry of the IR. Experience gained by several groups is discussed, and some of the solutions used in synchrotron light sources are presented.<> View full abstract»

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  • APS storage ring vacuum system development

    Publication Year: 1991 , Page(s): 29 - 31 vol.1
    Cited by:  Papers (3)
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    The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7-GeV positrons for the generation of photon beams for the facility's materials research program. The storage ring's 1104 m circumference is divided into 40 sectors which contain vacuum, beam transport, control, RF, and insertion device systems. The vacuum system will operate at a pressure of 1 nTorr and is fabricated from aluminum. The system includes distributed NeG pumping, photon absorbers with lumped pumping, beam positron monitors, vacuum diagnostics, and valving. An overview of the vacuum system design and details of selected development program results are presented.<> View full abstract»

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  • Design of superconducting magnets for the SSC

    Publication Year: 1991 , Page(s): 32 - 36 vol.1
    Cited by:  Papers (1)
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    It is shown that in order for a superconducting magnet to operate reliably at a given field the design should have sufficient superconductor to allow operation at currents significantly less than the cable critical current. In addition, sufficient copper should be included in the cable to give stability. Such considerations, their basis, and their application to the design of 5 cm bore diameter SSC dipoles are discussed.<> View full abstract»

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  • Field quality issues in superconducting magnets

    Publication Year: 1991 , Page(s): 37 - 41 vol.1
    Cited by:  Papers (1)
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    It is shown that the extensive measurements made on all magnets of the proton-electron collider HERA yield a wealth of information on the field quality that can be achieved in a large-scale industrial production of superconducting magnets. The field integrals of the dipoles and quadrupoles have been determined with a precision of 0.02 to 0.3%, the field orientation to within 0.15 mrad and the position of the quadrupole axis to within 0.2 mm. Higher harmonics have been measured at various excitations of the magnets and in collared coils at room temperature. The persistent-current contributions to the main field of the magnets and to the higher multipoles, as well as their time dependence, have been studied.<> View full abstract»

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  • A comparison of calculations and measurements of the field harmonics as a function of current in the SSC dipole magnets

    Publication Year: 1991 , Page(s): 42 - 44 vol.1
    Cited by:  Papers (2)
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    The effects of iron saturation on field harmonics are examined. The field harmonics change due to the persistent current in the superconducting wires and the deformation of the coil shape because of Lorentz forces. A discussion is presented of the variation in the sextupole harmonics with current and an explanation is given of the differences between the calculations and measurements. Also discussed are the skew quadrupole harmonic at high field in the long dipole magnets.<> View full abstract»

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  • Analysis of magnetic field measurement results for the AGS booster magnets

    Publication Year: 1991 , Page(s): 45 - 47 vol.1
    Cited by:  Papers (1)
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    Magnetic field measurements have been made on nearly 200 conventional magnets that have been installed in the AGS (Alternating Gradient Synchrotron) booster and its associated transfer lines. The measurement were intended to monitor the quality of the magnets being produced and to check the performance of each magnet before installation. The magnetic measurements efforts led to certain improvements in the manufacturing process, which subsequently produced very good, very uniform magnets. The integrated dipole fields of the 36 booster dipoles are uniform to 1.5 parts in ten thousand. The magnetic measurements indicate that the quadrupoles were manufactured to an accuracy of 3/10000 inch.<> View full abstract»

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  • Some recollections on the story of the cyclotron and comments on higher degrees

    Publication Year: 1991 , Page(s): 48 - 51 vol.1
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    The author outlines the advances in cyclotrons based on his experiences as a graduate student and later as a teacher. A discussion is presented on the Sector Focusing Cyclotron.<> View full abstract»

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  • Construction and early commissioning results of the AGS booster

    Publication Year: 1991 , Page(s): 52 - 56 vol.1
    Cited by:  Papers (2)
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    The AGS (Alternating Gradient Synchrotron) booster synchrotron has been designed to accelerate protons from 200 MeV to 1.5 GeV and heavy ions from several MeV per nucleon to several hundred MeV per nucleon for all the nuclei up to gold. The design requirements and measurement results of major accelerator components and systems are presneted. The early commissioning results of the injection are also presented.<> View full abstract»

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  • The TRIUMF Kaon Factory

    Publication Year: 1991 , Page(s): 57 - 61 vol.1
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    The TRIUMF Kaon Factory is designed to produce beams of kaons, antiprotons, other hadrons, and neutrinos 100 times more intense, or cleaner, than are available now, for a broad range of particle and nuclear physics experiments. This will require a 100- mu A beam of 30-GeV protons, to be produced by an interleaved sequence of two fast-cycling synchrotrons and three storage rings, with the existing TRIUMF H/sup -/ cyclotron as injector. A preconstruction study has enabled the overall design to be reviewed and prototypes of various components to be built and evaluated-fast-cycling dipole and quadrupole magnets, a dual-frequency magnet power supply, ceramic beam pipes with internal RF shields, and RF cavity (using perpendicular bias), an extraction kicker, an RF beam chopper, and production targets. Environmental, industrial, and economic impact studies have also been completed and the cost estimates and schedule updated.<> View full abstract»

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  • The Superconducting Super Collider low energy booster: a status report

    Publication Year: 1991 , Page(s): 62 - 64 vol.1
    Cited by:  Papers (4)
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    In collider fill mode, the low energy booster (LEB) will accelerate 10/sup 12/ protons in 114 bunches from an injection momentum of 1.22 GeV/c to a final momentum of 12 GeV/c, cycling at a frequency of 10 Hz. The most significant extension of present fast-cycling synchrotron technology arises from the requirement that the normalized transverse emittance (RMS) of the beam be > View full abstract»

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  • DA Phi NE: the Frascati Phi-factory

    Publication Year: 1991 , Page(s): 68 - 70 vol.1
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    An overview of the Frascati Phi -factory and the salient project features are presented. The engineering design of vacuum and magnetic components, diagnostics, power supplies of the accumulator ring and of the main rings is in progress. The main concern, at this time, is how to handle the multibunch instability that is the most harmful problem in the design of high current storage rings and the most serious limitation for the luminosity. The parasitic high-order modes of the RF cavities are responsible for such an instability.<> View full abstract»

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  • CW racetrack microtrons

    Publication Year: 1991 , Page(s): 71 - 75 vol.1
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    A review of the activities in construction and operation of CW racetrack microtrons (RTMs) since the 1983 PAC is presented. Of the half-dozen CW RTM projects reviewed, only two appear to have maintained sufficient financial support for completion. However, the technical support and cooperation demonstrated by all the laboratories involved in the design and development of RTM systems has contributed to the success of the surviving projects.<> View full abstract»

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  • Present status of ion cooler rings

    Publication Year: 1991 , Page(s): 76 - 80 vol.1
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    The activities at major cooling rings presently in operation or under construction are reviewed from the point of view of accelerator technology. It is proved that electron cooling could be effectively used for the non-Liouvillian handling of beams such as accumulation of ions with the cooling stacking method. Nuclear and atomic physics experiments so far performed, though they are still in the preliminary stage, show the usefulness of the cooler ring.<> View full abstract»

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  • Characteristics of the new Tevatron lattice

    Publication Year: 1991 , Page(s): 81 - 83 vol.1
    Cited by:  Papers (1)
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    The Tevatron low- beta lattice that allows operation of two independent low- beta insertions is described. The measurement of the beta functions at various locations near the interaction region of the B0 and comparisons to theoretical calculations are reported.<> View full abstract»

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  • PEP-II: an asymmetric B factory based on PEP

    Publication Year: 1991 , Page(s): 84 - 86 vol.1
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    An asymmetric B factory to be installed in the PEP (Positron Electron Project) tunnel has been under study for several years. A mature design for a 9 GeV*3.1 GeV electron-positron collider with a design luminosity of 3*10/sup 33/ cm/sup -2/ s/sup -1/ is presented. Solutions exist for all the technical problems, including issues related to high currents (e.g. beam instabilities, feedback systems, vacuum chamber design, lifetime degradation, and radiation power dissipation in the interaction region) and those related to the different energies of the beams (e.g. beam separation, beam-beam interaction, and detector requirements). The status of this project is discussed.<> View full abstract»

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  • Early operating experience with the new Tevatron low- beta insertion

    Publication Year: 1991 , Page(s): 87 - 89 vol.1
    Cited by:  Papers (3)
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    New low- beta insertions will be used in the Tevatron collider at both the B0 and D0 interaction regions. To reduce the beam-beam tune shift, electrostatic separators will be installed to separate the beams horizontally and vertically at all but the two interaction points. An insertion has been installed at the B0 straight section and enough separators to create collisions at B0 only. The initial beam tests using these devices are described. The procedures for tuning of the insertion and separators are described. Also discussed is the procedure to change the lattice from the injection lattice to the 50-cm beta lattice used in high energy physics.<> View full abstract»

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  • Prospects for tunes near the integer at the Fermilab pp collider

    Publication Year: 1991 , Page(s): 90 - 92 vol.1
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    A series of experiments with the Tevatron collider have been conducted with the goal of the operation of the machine with betatron tunes near 19.05. Experiments near the integer working point are described, including closed orbit control and emittance growth due to power supply noise. Results from a pp store with large p tune shifts and tunes near the integer are described.<> View full abstract»

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  • Common mode noise on the main Tevatron bus and associated beam emittance growth

    Publication Year: 1991 , Page(s): 93 - 95 vol.1
    Cited by:  Papers (1)
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    Overlap of betatron tune frequencies with the power supply noise spectrum can cause transverse beam emittance growth in a storage ring. This effect has been studied for tunes near the integer, where the betatron frequency is low. By injecting noise onto the main power supply bus, it was determined that common mode noise was the dominant source of emittance growth. A noise suppression feedback loop was used to reduce the noise and the emittance growth. These experiments are described, as are investigations of the common mode propagation along with the Tevatron bus and measurements of the fields generated by common mode excitation of isolated Tevatron magnets.<> View full abstract»

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  • Design and multiparticle simulation of the half integer slow extraction system for the main injector

    Publication Year: 1991 , Page(s): 96 - 98 vol.1
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    One of the roles of the main injector ring in the second phase of the Fermilab upgrade is to deliver year-round slow extracted 120-GeV test beams. The half-integer slow extraction system design and results from a Monte Carlo simulation of fast spill are presented. The simulation was performed with a computer tracking program based on the TEVLAT program with a large number of particles (up to 1000). Particle tracking included the systematic errors produced by the magnetic multipoles with the dipoles and quadrupoles as well as random multipole errors.<> View full abstract»

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